Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

21 files changed, 14949 insertions, 0 deletions

diff --git a/fs/ext3/Makefile b/fs/ext3/Makefile
new file mode 100644
index 000000000000..704cd44a40c2
--- /dev/null
+++ b/fs/ext3/Makefile
@@ -0,0 +1,12 @@
+#
+# Makefile for the linux ext3-filesystem routines.
+#
+
+obj-$(CONFIG_EXT3_FS) += ext3.o
+
+ext3-y  := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
+           ioctl.o namei.o super.o symlink.o hash.o resize.o
+
+ext3-$(CONFIG_EXT3_FS_XATTR)     += xattr.o xattr_user.o xattr_trusted.o
+ext3-$(CONFIG_EXT3_FS_POSIX_ACL) += acl.o
+ext3-$(CONFIG_EXT3_FS_SECURITY)  += xattr_security.o
diff --git a/fs/ext3/acl.c b/fs/ext3/acl.c
new file mode 100644
index 000000000000..328592c3a956
--- /dev/null
+++ b/fs/ext3/acl.c
@@ -0,0 +1,547 @@
+/*
+ * linux/fs/ext3/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Convert from filesystem to in-memory representation.
+ */
+static struct posix_acl *
+ext3_acl_from_disk(const void *value, size_t size)
+{
+        const char *end = (char *)value + size;
+        int n, count;
+        struct posix_acl *acl;
+
+        if (!value)
+                return NULL;
+        if (size < sizeof(ext3_acl_header))
+                 return ERR_PTR(-EINVAL);
+        if (((ext3_acl_header *)value)->a_version !=
+            cpu_to_le32(EXT3_ACL_VERSION))
+                return ERR_PTR(-EINVAL);
+        value = (char *)value + sizeof(ext3_acl_header);
+        count = ext3_acl_count(size);
+        if (count < 0)
+                return ERR_PTR(-EINVAL);
+        if (count == 0)
+                return NULL;
+        acl = posix_acl_alloc(count, GFP_KERNEL);
+        if (!acl)
+                return ERR_PTR(-ENOMEM);
+        for (n=0; n < count; n++) {
+                ext3_acl_entry *entry =
+                        (ext3_acl_entry *)value;
+                if ((char *)value + sizeof(ext3_acl_entry_short) > end)
+                        goto fail;
+                acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
+                acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+                switch(acl->a_entries[n].e_tag) {
+                        case ACL_USER_OBJ:
+                        case ACL_GROUP_OBJ:
+                        case ACL_MASK:
+                        case ACL_OTHER:
+                                value = (char *)value +
+                                        sizeof(ext3_acl_entry_short);
+                                acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
+                                break;
+
+                        case ACL_USER:
+                        case ACL_GROUP:
+                                value = (char *)value + sizeof(ext3_acl_entry);
+                                if ((char *)value > end)
+                                        goto fail;
+                                acl->a_entries[n].e_id =
+                                        le32_to_cpu(entry->e_id);
+                                break;
+
+                        default:
+                                goto fail;
+                }
+        }
+        if (value != end)
+                goto fail;
+        return acl;
+
+fail:
+        posix_acl_release(acl);
+        return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Convert from in-memory to filesystem representation.
+ */
+static void *
+ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+        ext3_acl_header *ext_acl;
+        char *e;
+        size_t n;
+
+        *size = ext3_acl_size(acl->a_count);
+        ext_acl = (ext3_acl_header *)kmalloc(sizeof(ext3_acl_header) +
+                acl->a_count * sizeof(ext3_acl_entry), GFP_KERNEL);
+        if (!ext_acl)
+                return ERR_PTR(-ENOMEM);
+        ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
+        e = (char *)ext_acl + sizeof(ext3_acl_header);
+        for (n=0; n < acl->a_count; n++) {
+                ext3_acl_entry *entry = (ext3_acl_entry *)e;
+                entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
+                entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
+                switch(acl->a_entries[n].e_tag) {
+                        case ACL_USER:
+                        case ACL_GROUP:
+                                entry->e_id =
+                                        cpu_to_le32(acl->a_entries[n].e_id);
+                                e += sizeof(ext3_acl_entry);
+                                break;
+
+                        case ACL_USER_OBJ:
+                        case ACL_GROUP_OBJ:
+                        case ACL_MASK:
+                        case ACL_OTHER:
+                                e += sizeof(ext3_acl_entry_short);
+                                break;
+
+                        default:
+                                goto fail;
+                }
+        }
+        return (char *)ext_acl;
+
+fail:
+        kfree(ext_acl);
+        return ERR_PTR(-EINVAL);
+}
+
+static inline struct posix_acl *
+ext3_iget_acl(struct inode *inode, struct posix_acl **i_acl)
+{
+        struct posix_acl *acl = EXT3_ACL_NOT_CACHED;
+
+        spin_lock(&inode->i_lock);
+        if (*i_acl != EXT3_ACL_NOT_CACHED)
+                acl = posix_acl_dup(*i_acl);
+        spin_unlock(&inode->i_lock);
+
+        return acl;
+}
+
+static inline void
+ext3_iset_acl(struct inode *inode, struct posix_acl **i_acl,
+                  struct posix_acl *acl)
+{
+        spin_lock(&inode->i_lock);
+        if (*i_acl != EXT3_ACL_NOT_CACHED)
+                posix_acl_release(*i_acl);
+        *i_acl = posix_acl_dup(acl);
+        spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Inode operation get_posix_acl().
+ *
+ * inode->i_sem: don't care
+ */
+static struct posix_acl *
+ext3_get_acl(struct inode *inode, int type)
+{
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        int name_index;
+        char *value = NULL;
+        struct posix_acl *acl;
+        int retval;
+
+        if (!test_opt(inode->i_sb, POSIX_ACL))
+                return NULL;
+
+        switch(type) {
+                case ACL_TYPE_ACCESS:
+                        acl = ext3_iget_acl(inode, &ei->i_acl);
+                        if (acl != EXT3_ACL_NOT_CACHED)
+                                return acl;
+                        name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
+                        break;
+
+                case ACL_TYPE_DEFAULT:
+                        acl = ext3_iget_acl(inode, &ei->i_default_acl);
+                        if (acl != EXT3_ACL_NOT_CACHED)
+                                return acl;
+                        name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
+                        break;
+
+                default:
+                        return ERR_PTR(-EINVAL);
+        }
+        retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
+        if (retval > 0) {
+                value = kmalloc(retval, GFP_KERNEL);
+                if (!value)
+                        return ERR_PTR(-ENOMEM);
+                retval = ext3_xattr_get(inode, name_index, "", value, retval);
+        }
+        if (retval > 0)
+                acl = ext3_acl_from_disk(value, retval);
+        else if (retval == -ENODATA || retval == -ENOSYS)
+                acl = NULL;
+        else
+                acl = ERR_PTR(retval);
+        kfree(value);
+
+        if (!IS_ERR(acl)) {
+                switch(type) {
+                        case ACL_TYPE_ACCESS:
+                                ext3_iset_acl(inode, &ei->i_acl, acl);
+                                break;
+
+                        case ACL_TYPE_DEFAULT:
+                                ext3_iset_acl(inode, &ei->i_default_acl, acl);
+                                break;
+                }
+        }
+        return acl;
+}
+
+/*
+ * Set the access or default ACL of an inode.
+ *
+ * inode->i_sem: down unless called from ext3_new_inode
+ */
+static int
+ext3_set_acl(handle_t *handle, struct inode *inode, int type,
+             struct posix_acl *acl)
+{
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        int name_index;
+        void *value = NULL;
+        size_t size;
+        int error;
+
+        if (S_ISLNK(inode->i_mode))
+                return -EOPNOTSUPP;
+
+        switch(type) {
+                case ACL_TYPE_ACCESS:
+                        name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
+                        if (acl) {
+                                mode_t mode = inode->i_mode;
+                                error = posix_acl_equiv_mode(acl, &mode);
+                                if (error < 0)
+                                        return error;
+                                else {
+                                        inode->i_mode = mode;
+                                        ext3_mark_inode_dirty(handle, inode);
+                                        if (error == 0)
+                                                acl = NULL;
+                                }
+                        }
+                        break;
+
+                case ACL_TYPE_DEFAULT:
+                        name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
+                        if (!S_ISDIR(inode->i_mode))
+                                return acl ? -EACCES : 0;
+                        break;
+
+                default:
+                        return -EINVAL;
+        }
+        if (acl) {
+                value = ext3_acl_to_disk(acl, &size);
+                if (IS_ERR(value))
+                        return (int)PTR_ERR(value);
+        }
+
+        error = ext3_xattr_set_handle(handle, inode, name_index, "",
+                                      value, size, 0);
+
+        kfree(value);
+        if (!error) {
+                switch(type) {
+                        case ACL_TYPE_ACCESS:
+                                ext3_iset_acl(inode, &ei->i_acl, acl);
+                                break;
+
+                        case ACL_TYPE_DEFAULT:
+                                ext3_iset_acl(inode, &ei->i_default_acl, acl);
+                                break;
+                }
+        }
+        return error;
+}
+
+static int
+ext3_check_acl(struct inode *inode, int mask)
+{
+        struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
+
+        if (acl) {
+                int error = posix_acl_permission(inode, acl, mask);
+                posix_acl_release(acl);
+                return error;
+        }
+
+        return -EAGAIN;
+}
+
+int
+ext3_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+        return generic_permission(inode, mask, ext3_check_acl);
+}
+
+/*
+ * Initialize the ACLs of a new inode. Called from ext3_new_inode.
+ *
+ * dir->i_sem: down
+ * inode->i_sem: up (access to inode is still exclusive)
+ */
+int
+ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+        struct posix_acl *acl = NULL;
+        int error = 0;
+
+        if (!S_ISLNK(inode->i_mode)) {
+                if (test_opt(dir->i_sb, POSIX_ACL)) {
+                        acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
+                        if (IS_ERR(acl))
+                                return PTR_ERR(acl);
+                }
+                if (!acl)
+                        inode->i_mode &= ~current->fs->umask;
+        }
+        if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
+                struct posix_acl *clone;
+                mode_t mode;
+
+                if (S_ISDIR(inode->i_mode)) {
+                        error = ext3_set_acl(handle, inode,
+                                             ACL_TYPE_DEFAULT, acl);
+                        if (error)
+                                goto cleanup;
+                }
+                clone = posix_acl_clone(acl, GFP_KERNEL);
+                error = -ENOMEM;
+                if (!clone)
+                        goto cleanup;
+
+                mode = inode->i_mode;
+                error = posix_acl_create_masq(clone, &mode);
+                if (error >= 0) {
+                        inode->i_mode = mode;
+                        if (error > 0) {
+                                /* This is an extended ACL */
+                                error = ext3_set_acl(handle, inode,
+                                                     ACL_TYPE_ACCESS, clone);
+                        }
+                }
+                posix_acl_release(clone);
+        }
+cleanup:
+        posix_acl_release(acl);
+        return error;
+}
+
+/*
+ * Does chmod for an inode that may have an Access Control List. The
+ * inode->i_mode field must be updated to the desired value by the caller
+ * before calling this function.
+ * Returns 0 on success, or a negative error number.
+ *
+ * We change the ACL rather than storing some ACL entries in the file
+ * mode permission bits (which would be more efficient), because that
+ * would break once additional permissions (like  ACL_APPEND, ACL_DELETE
+ * for directories) are added. There are no more bits available in the
+ * file mode.
+ *
+ * inode->i_sem: down
+ */
+int
+ext3_acl_chmod(struct inode *inode)
+{
+        struct posix_acl *acl, *clone;
+        int error;
+
+        if (S_ISLNK(inode->i_mode))
+                return -EOPNOTSUPP;
+        if (!test_opt(inode->i_sb, POSIX_ACL))
+                return 0;
+        acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
+        if (IS_ERR(acl) || !acl)
+                return PTR_ERR(acl);
+        clone = posix_acl_clone(acl, GFP_KERNEL);
+        posix_acl_release(acl);
+        if (!clone)
+                return -ENOMEM;
+        error = posix_acl_chmod_masq(clone, inode->i_mode);
+        if (!error) {
+                handle_t *handle;
+                int retries = 0;
+
+        retry:
+                handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
+                if (IS_ERR(handle)) {
+                        error = PTR_ERR(handle);
+                        ext3_std_error(inode->i_sb, error);
+                        goto out;
+                }
+                error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
+                ext3_journal_stop(handle);
+                if (error == -ENOSPC &&
+                    ext3_should_retry_alloc(inode->i_sb, &retries))
+                        goto retry;
+        }
+out:
+        posix_acl_release(clone);
+        return error;
+}
+
+/*
+ * Extended attribute handlers
+ */
+static size_t
+ext3_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
+                           const char *name, size_t name_len)
+{
+        const size_t size = sizeof(XATTR_NAME_ACL_ACCESS);
+
+        if (!test_opt(inode->i_sb, POSIX_ACL))
+                return 0;
+        if (list && size <= list_len)
+                memcpy(list, XATTR_NAME_ACL_ACCESS, size);
+        return size;
+}
+
+static size_t
+ext3_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
+                            const char *name, size_t name_len)
+{
+        const size_t size = sizeof(XATTR_NAME_ACL_DEFAULT);
+
+        if (!test_opt(inode->i_sb, POSIX_ACL))
+                return 0;
+        if (list && size <= list_len)
+                memcpy(list, XATTR_NAME_ACL_DEFAULT, size);
+        return size;
+}
+
+static int
+ext3_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
+{
+        struct posix_acl *acl;
+        int error;
+
+        if (!test_opt(inode->i_sb, POSIX_ACL))
+                return -EOPNOTSUPP;
+
+        acl = ext3_get_acl(inode, type);
+        if (IS_ERR(acl))
+                return PTR_ERR(acl);
+        if (acl == NULL)
+                return -ENODATA;
+        error = posix_acl_to_xattr(acl, buffer, size);
+        posix_acl_release(acl);
+
+        return error;
+}
+
+static int
+ext3_xattr_get_acl_access(struct inode *inode, const char *name,
+                          void *buffer, size_t size)
+{
+        if (strcmp(name, "") != 0)
+                return -EINVAL;
+        return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
+}
+
+static int
+ext3_xattr_get_acl_default(struct inode *inode, const char *name,
+                           void *buffer, size_t size)
+{
+        if (strcmp(name, "") != 0)
+                return -EINVAL;
+        return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
+}
+
+static int
+ext3_xattr_set_acl(struct inode *inode, int type, const void *value,
+                   size_t size)
+{
+        handle_t *handle;
+        struct posix_acl *acl;
+        int error, retries = 0;
+
+        if (!test_opt(inode->i_sb, POSIX_ACL))
+                return -EOPNOTSUPP;
+        if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+                return -EPERM;
+
+        if (value) {
+                acl = posix_acl_from_xattr(value, size);
+                if (IS_ERR(acl))
+                        return PTR_ERR(acl);
+                else if (acl) {
+                        error = posix_acl_valid(acl);
+                        if (error)
+                                goto release_and_out;
+                }
+        } else
+                acl = NULL;
+
+retry:
+        handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        error = ext3_set_acl(handle, inode, type, acl);
+        ext3_journal_stop(handle);
+        if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
+                goto retry;
+
+release_and_out:
+        posix_acl_release(acl);
+        return error;
+}
+
+static int
+ext3_xattr_set_acl_access(struct inode *inode, const char *name,
+                          const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") != 0)
+                return -EINVAL;
+        return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int
+ext3_xattr_set_acl_default(struct inode *inode, const char *name,
+                           const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") != 0)
+                return -EINVAL;
+        return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+struct xattr_handler ext3_xattr_acl_access_handler = {
+        .prefix = XATTR_NAME_ACL_ACCESS,
+        .list   = ext3_xattr_list_acl_access,
+        .get    = ext3_xattr_get_acl_access,
+        .set    = ext3_xattr_set_acl_access,
+};
+
+struct xattr_handler ext3_xattr_acl_default_handler = {
+        .prefix = XATTR_NAME_ACL_DEFAULT,
+        .list   = ext3_xattr_list_acl_default,
+        .get    = ext3_xattr_get_acl_default,
+        .set    = ext3_xattr_set_acl_default,
+};
diff --git a/fs/ext3/acl.h b/fs/ext3/acl.h
new file mode 100644
index 000000000000..98af0c0d0ba9
--- /dev/null
+++ b/fs/ext3/acl.h
@@ -0,0 +1,84 @@
+/*
+  File: fs/ext3/acl.h
+
+  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/xattr_acl.h>
+
+#define EXT3_ACL_VERSION        0x0001
+
+typedef struct {
+        __le16          e_tag;
+        __le16          e_perm;
+        __le32          e_id;
+} ext3_acl_entry;
+
+typedef struct {
+        __le16          e_tag;
+        __le16          e_perm;
+} ext3_acl_entry_short;
+
+typedef struct {
+        __le32          a_version;
+} ext3_acl_header;
+
+static inline size_t ext3_acl_size(int count)
+{
+        if (count <= 4) {
+                return sizeof(ext3_acl_header) +
+                       count * sizeof(ext3_acl_entry_short);
+        } else {
+                return sizeof(ext3_acl_header) +
+                       4 * sizeof(ext3_acl_entry_short) +
+                       (count - 4) * sizeof(ext3_acl_entry);
+        }
+}
+
+static inline int ext3_acl_count(size_t size)
+{
+        ssize_t s;
+        size -= sizeof(ext3_acl_header);
+        s = size - 4 * sizeof(ext3_acl_entry_short);
+        if (s < 0) {
+                if (size % sizeof(ext3_acl_entry_short))
+                        return -1;
+                return size / sizeof(ext3_acl_entry_short);
+        } else {
+                if (s % sizeof(ext3_acl_entry))
+                        return -1;
+                return s / sizeof(ext3_acl_entry) + 4;
+        }
+}
+
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+
+/* Value for inode->u.ext3_i.i_acl and inode->u.ext3_i.i_default_acl
+   if the ACL has not been cached */
+#define EXT3_ACL_NOT_CACHED ((void *)-1)
+
+/* acl.c */
+extern int ext3_permission (struct inode *, int, struct nameidata *);
+extern int ext3_acl_chmod (struct inode *);
+extern int ext3_init_acl (handle_t *, struct inode *, struct inode *);
+
+extern int init_ext3_acl(void);
+extern void exit_ext3_acl(void);
+
+#else  /* CONFIG_EXT3_FS_POSIX_ACL */
+#include <linux/sched.h>
+#define ext3_permission NULL
+
+static inline int
+ext3_acl_chmod(struct inode *inode)
+{
+        return 0;
+}
+
+static inline int
+ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+        return 0;
+}
+#endif  /* CONFIG_EXT3_FS_POSIX_ACL */
+
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
new file mode 100644
index 000000000000..ccd632fcc6d8
--- /dev/null
+++ b/fs/ext3/balloc.c
@@ -0,0 +1,1600 @@
+/*
+ *  linux/fs/ext3/balloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/config.h>
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+
+/*
+ * balloc.c contains the blocks allocation and deallocation routines
+ */
+
+/*
+ * The free blocks are managed by bitmaps.  A file system contains several
+ * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block.  Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block.  The descriptors are loaded in memory
+ * when a file system is mounted (see ext3_read_super).
+ */
+
+
+#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
+
+struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
+                                             unsigned int block_group,
+                                             struct buffer_head ** bh)
+{
+        unsigned long group_desc;
+        unsigned long offset;
+        struct ext3_group_desc * desc;
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+
+        if (block_group >= sbi->s_groups_count) {
+                ext3_error (sb, "ext3_get_group_desc",
+                            "block_group >= groups_count - "
+                            "block_group = %d, groups_count = %lu",
+                            block_group, sbi->s_groups_count);
+
+                return NULL;
+        }
+        smp_rmb();
+
+        group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
+        offset = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
+        if (!sbi->s_group_desc[group_desc]) {
+                ext3_error (sb, "ext3_get_group_desc",
+                            "Group descriptor not loaded - "
+                            "block_group = %d, group_desc = %lu, desc = %lu",
+                             block_group, group_desc, offset);
+                return NULL;
+        }
+
+        desc = (struct ext3_group_desc *) sbi->s_group_desc[group_desc]->b_data;
+        if (bh)
+                *bh = sbi->s_group_desc[group_desc];
+        return desc + offset;
+}
+
+/*
+ * Read the bitmap for a given block_group, reading into the specified 
+ * slot in the superblock's bitmap cache.
+ *
+ * Return buffer_head on success or NULL in case of failure.
+ */
+static struct buffer_head *
+read_block_bitmap(struct super_block *sb, unsigned int block_group)
+{
+        struct ext3_group_desc * desc;
+        struct buffer_head * bh = NULL;
+
+        desc = ext3_get_group_desc (sb, block_group, NULL);
+        if (!desc)
+                goto error_out;
+        bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
+        if (!bh)
+                ext3_error (sb, "read_block_bitmap",
+                            "Cannot read block bitmap - "
+                            "block_group = %d, block_bitmap = %u",
+                            block_group, le32_to_cpu(desc->bg_block_bitmap));
+error_out:
+        return bh;
+}
+/*
+ * The reservation window structure operations
+ * --------------------------------------------
+ * Operations include:
+ * dump, find, add, remove, is_empty, find_next_reservable_window, etc.
+ *
+ * We use sorted double linked list for the per-filesystem reservation
+ * window list. (like in vm_region).
+ *
+ * Initially, we keep those small operations in the abstract functions,
+ * so later if we need a better searching tree than double linked-list,
+ * we could easily switch to that without changing too much
+ * code.
+ */
+#if 0
+static void __rsv_window_dump(struct rb_root *root, int verbose,
+                              const char *fn)
+{
+        struct rb_node *n;
+        struct ext3_reserve_window_node *rsv, *prev;
+        int bad;
+
+restart:
+        n = rb_first(root);
+        bad = 0;
+        prev = NULL;
+
+        printk("Block Allocation Reservation Windows Map (%s):\n", fn);
+        while (n) {
+                rsv = list_entry(n, struct ext3_reserve_window_node, rsv_node);
+                if (verbose)
+                        printk("reservation window 0x%p "
+                               "start:  %d, end:  %d\n",
+                               rsv, rsv->rsv_start, rsv->rsv_end);
+                if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) {
+                        printk("Bad reservation %p (start >= end)\n",
+                               rsv);
+                        bad = 1;
+                }
+                if (prev && prev->rsv_end >= rsv->rsv_start) {
+                        printk("Bad reservation %p (prev->end >= start)\n",
+                               rsv);
+                        bad = 1;
+                }
+                if (bad) {
+                        if (!verbose) {
+                                printk("Restarting reservation walk in verbose mode\n");
+                                verbose = 1;
+                                goto restart;
+                        }
+                }
+                n = rb_next(n);
+                prev = rsv;
+        }
+        printk("Window map complete.\n");
+        if (bad)
+                BUG();
+}
+#define rsv_window_dump(root, verbose) \
+        __rsv_window_dump((root), (verbose), __FUNCTION__)
+#else
+#define rsv_window_dump(root, verbose) do {} while (0)
+#endif
+
+static int
+goal_in_my_reservation(struct ext3_reserve_window *rsv, int goal,
+                        unsigned int group, struct super_block * sb)
+{
+        unsigned long group_first_block, group_last_block;
+
+        group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
+                                group * EXT3_BLOCKS_PER_GROUP(sb);
+        group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+
+        if ((rsv->_rsv_start > group_last_block) ||
+            (rsv->_rsv_end < group_first_block))
+                return 0;
+        if ((goal >= 0) && ((goal + group_first_block < rsv->_rsv_start)
+                || (goal + group_first_block > rsv->_rsv_end)))
+                return 0;
+        return 1;
+}
+
+/*
+ * Find the reserved window which includes the goal, or the previous one
+ * if the goal is not in any window.
+ * Returns NULL if there are no windows or if all windows start after the goal.
+ */
+static struct ext3_reserve_window_node *
+search_reserve_window(struct rb_root *root, unsigned long goal)
+{
+        struct rb_node *n = root->rb_node;
+        struct ext3_reserve_window_node *rsv;
+
+        if (!n)
+                return NULL;
+
+        do {
+                rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node);
+
+                if (goal < rsv->rsv_start)
+                        n = n->rb_left;
+                else if (goal > rsv->rsv_end)
+                        n = n->rb_right;
+                else
+                        return rsv;
+        } while (n);
+        /*
+         * We've fallen off the end of the tree: the goal wasn't inside
+         * any particular node.  OK, the previous node must be to one
+         * side of the interval containing the goal.  If it's the RHS,
+         * we need to back up one.
+         */
+        if (rsv->rsv_start > goal) {
+                n = rb_prev(&rsv->rsv_node);
+                rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node);
+        }
+        return rsv;
+}
+
+void ext3_rsv_window_add(struct super_block *sb,
+                    struct ext3_reserve_window_node *rsv)
+{
+        struct rb_root *root = &EXT3_SB(sb)->s_rsv_window_root;
+        struct rb_node *node = &rsv->rsv_node;
+        unsigned int start = rsv->rsv_start;
+
+        struct rb_node ** p = &root->rb_node;
+        struct rb_node * parent = NULL;
+        struct ext3_reserve_window_node *this;
+
+        while (*p)
+        {
+                parent = *p;
+                this = rb_entry(parent, struct ext3_reserve_window_node, rsv_node);
+
+                if (start < this->rsv_start)
+                        p = &(*p)->rb_left;
+                else if (start > this->rsv_end)
+                        p = &(*p)->rb_right;
+                else
+                        BUG();
+        }
+
+        rb_link_node(node, parent, p);
+        rb_insert_color(node, root);
+}
+
+static void rsv_window_remove(struct super_block *sb,
+                              struct ext3_reserve_window_node *rsv)
+{
+        rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+        rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+        rsv->rsv_alloc_hit = 0;
+        rb_erase(&rsv->rsv_node, &EXT3_SB(sb)->s_rsv_window_root);
+}
+
+static inline int rsv_is_empty(struct ext3_reserve_window *rsv)
+{
+        /* a valid reservation end block could not be 0 */
+        return (rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED);
+}
+void ext3_init_block_alloc_info(struct inode *inode)
+{
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info;
+        struct super_block *sb = inode->i_sb;
+
+        block_i = kmalloc(sizeof(*block_i), GFP_NOFS);
+        if (block_i) {
+                struct ext3_reserve_window_node *rsv = &block_i->rsv_window_node;
+
+                rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+                rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+
+                /*
+                 * if filesystem is mounted with NORESERVATION, the goal
+                 * reservation window size is set to zero to indicate
+                 * block reservation is off
+                 */
+                if (!test_opt(sb, RESERVATION))
+                        rsv->rsv_goal_size = 0;
+                else
+                        rsv->rsv_goal_size = EXT3_DEFAULT_RESERVE_BLOCKS;
+                rsv->rsv_alloc_hit = 0;
+                block_i->last_alloc_logical_block = 0;
+                block_i->last_alloc_physical_block = 0;
+        }
+        ei->i_block_alloc_info = block_i;
+}
+
+void ext3_discard_reservation(struct inode *inode)
+{
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info;
+        struct ext3_reserve_window_node *rsv;
+        spinlock_t *rsv_lock = &EXT3_SB(inode->i_sb)->s_rsv_window_lock;
+
+        if (!block_i)
+                return;
+
+        rsv = &block_i->rsv_window_node;
+        if (!rsv_is_empty(&rsv->rsv_window)) {
+                spin_lock(rsv_lock);
+                if (!rsv_is_empty(&rsv->rsv_window))
+                        rsv_window_remove(inode->i_sb, rsv);
+                spin_unlock(rsv_lock);
+        }
+}
+
+/* Free given blocks, update quota and i_blocks field */
+void ext3_free_blocks_sb(handle_t *handle, struct super_block *sb,
+                         unsigned long block, unsigned long count,
+                         int *pdquot_freed_blocks)
+{
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *gd_bh;
+        unsigned long block_group;
+        unsigned long bit;
+        unsigned long i;
+        unsigned long overflow;
+        struct ext3_group_desc * desc;
+        struct ext3_super_block * es;
+        struct ext3_sb_info *sbi;
+        int err = 0, ret;
+        unsigned group_freed;
+
+        *pdquot_freed_blocks = 0;
+        sbi = EXT3_SB(sb);
+        es = sbi->s_es;
+        if (block < le32_to_cpu(es->s_first_data_block) ||
+            block + count < block ||
+            block + count > le32_to_cpu(es->s_blocks_count)) {
+                ext3_error (sb, "ext3_free_blocks",
+                            "Freeing blocks not in datazone - "
+                            "block = %lu, count = %lu", block, count);
+                goto error_return;
+        }
+
+        ext3_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1);
+
+do_more:
+        overflow = 0;
+        block_group = (block - le32_to_cpu(es->s_first_data_block)) /
+                      EXT3_BLOCKS_PER_GROUP(sb);
+        bit = (block - le32_to_cpu(es->s_first_data_block)) %
+                      EXT3_BLOCKS_PER_GROUP(sb);
+        /*
+         * Check to see if we are freeing blocks across a group
+         * boundary.
+         */
+        if (bit + count > EXT3_BLOCKS_PER_GROUP(sb)) {
+                overflow = bit + count - EXT3_BLOCKS_PER_GROUP(sb);
+                count -= overflow;
+        }
+        brelse(bitmap_bh);
+        bitmap_bh = read_block_bitmap(sb, block_group);
+        if (!bitmap_bh)
+                goto error_return;
+        desc = ext3_get_group_desc (sb, block_group, &gd_bh);
+        if (!desc)
+                goto error_return;
+
+        if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) ||
+            in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) ||
+            in_range (block, le32_to_cpu(desc->bg_inode_table),
+                      sbi->s_itb_per_group) ||
+            in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
+                      sbi->s_itb_per_group))
+                ext3_error (sb, "ext3_free_blocks",
+                            "Freeing blocks in system zones - "
+                            "Block = %lu, count = %lu",
+                            block, count);
+
+        /*
+         * We are about to start releasing blocks in the bitmap,
+         * so we need undo access.
+         */
+        /* @@@ check errors */
+        BUFFER_TRACE(bitmap_bh, "getting undo access");
+        err = ext3_journal_get_undo_access(handle, bitmap_bh);
+        if (err)
+                goto error_return;
+
+        /*
+         * We are about to modify some metadata.  Call the journal APIs
+         * to unshare ->b_data if a currently-committing transaction is
+         * using it
+         */
+        BUFFER_TRACE(gd_bh, "get_write_access");
+        err = ext3_journal_get_write_access(handle, gd_bh);
+        if (err)
+                goto error_return;
+
+        jbd_lock_bh_state(bitmap_bh);
+
+        for (i = 0, group_freed = 0; i < count; i++) {
+                /*
+                 * An HJ special.  This is expensive...
+                 */
+#ifdef CONFIG_JBD_DEBUG
+                jbd_unlock_bh_state(bitmap_bh);
+                {
+                        struct buffer_head *debug_bh;
+                        debug_bh = sb_find_get_block(sb, block + i);
+                        if (debug_bh) {
+                                BUFFER_TRACE(debug_bh, "Deleted!");
+                                if (!bh2jh(bitmap_bh)->b_committed_data)
+                                        BUFFER_TRACE(debug_bh,
+                                                "No commited data in bitmap");
+                                BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap");
+                                __brelse(debug_bh);
+                        }
+                }
+                jbd_lock_bh_state(bitmap_bh);
+#endif
+                if (need_resched()) {
+                        jbd_unlock_bh_state(bitmap_bh);
+                        cond_resched();
+                        jbd_lock_bh_state(bitmap_bh);
+                }
+                /* @@@ This prevents newly-allocated data from being
+                 * freed and then reallocated within the same
+                 * transaction. 
+                 * 
+                 * Ideally we would want to allow that to happen, but to
+                 * do so requires making journal_forget() capable of
+                 * revoking the queued write of a data block, which
+                 * implies blocking on the journal lock.  *forget()
+                 * cannot block due to truncate races.
+                 *
+                 * Eventually we can fix this by making journal_forget()
+                 * return a status indicating whether or not it was able
+                 * to revoke the buffer.  On successful revoke, it is
+                 * safe not to set the allocation bit in the committed
+                 * bitmap, because we know that there is no outstanding
+                 * activity on the buffer any more and so it is safe to
+                 * reallocate it.  
+                 */
+                BUFFER_TRACE(bitmap_bh, "set in b_committed_data");
+                J_ASSERT_BH(bitmap_bh,
+                                bh2jh(bitmap_bh)->b_committed_data != NULL);
+                ext3_set_bit_atomic(sb_bgl_lock(sbi, block_group), bit + i,
+                                bh2jh(bitmap_bh)->b_committed_data);
+
+                /*
+                 * We clear the bit in the bitmap after setting the committed
+                 * data bit, because this is the reverse order to that which
+                 * the allocator uses.
+                 */
+                BUFFER_TRACE(bitmap_bh, "clear bit");
+                if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
+                                                bit + i, bitmap_bh->b_data)) {
+                        jbd_unlock_bh_state(bitmap_bh);
+                        ext3_error(sb, __FUNCTION__,
+                                "bit already cleared for block %lu", block + i);
+                        jbd_lock_bh_state(bitmap_bh);
+                        BUFFER_TRACE(bitmap_bh, "bit already cleared");
+                } else {
+                        group_freed++;
+                }
+        }
+        jbd_unlock_bh_state(bitmap_bh);
+
+        spin_lock(sb_bgl_lock(sbi, block_group));
+        desc->bg_free_blocks_count =
+                cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) +
+                        group_freed);
+        spin_unlock(sb_bgl_lock(sbi, block_group));
+        percpu_counter_mod(&sbi->s_freeblocks_counter, count);
+
+        /* We dirtied the bitmap block */
+        BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
+        err = ext3_journal_dirty_metadata(handle, bitmap_bh);
+
+        /* And the group descriptor block */
+        BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
+        ret = ext3_journal_dirty_metadata(handle, gd_bh);
+        if (!err) err = ret;
+        *pdquot_freed_blocks += group_freed;
+
+        if (overflow && !err) {
+                block += count;
+                count = overflow;
+                goto do_more;
+        }
+        sb->s_dirt = 1;
+error_return:
+        brelse(bitmap_bh);
+        ext3_std_error(sb, err);
+        return;
+}
+
+/* Free given blocks, update quota and i_blocks field */
+void ext3_free_blocks(handle_t *handle, struct inode *inode,
+                        unsigned long block, unsigned long count)
+{
+        struct super_block * sb;
+        int dquot_freed_blocks;
+
+        sb = inode->i_sb;
+        if (!sb) {
+                printk ("ext3_free_blocks: nonexistent device");
+                return;
+        }
+        ext3_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks);
+        if (dquot_freed_blocks)
+                DQUOT_FREE_BLOCK(inode, dquot_freed_blocks);
+        return;
+}
+
+/*
+ * For ext3 allocations, we must not reuse any blocks which are
+ * allocated in the bitmap buffer's "last committed data" copy.  This
+ * prevents deletes from freeing up the page for reuse until we have
+ * committed the delete transaction.
+ *
+ * If we didn't do this, then deleting something and reallocating it as
+ * data would allow the old block to be overwritten before the
+ * transaction committed (because we force data to disk before commit).
+ * This would lead to corruption if we crashed between overwriting the
+ * data and committing the delete. 
+ *
+ * @@@ We may want to make this allocation behaviour conditional on
+ * data-writes at some point, and disable it for metadata allocations or
+ * sync-data inodes.
+ */
+static int ext3_test_allocatable(int nr, struct buffer_head *bh)
+{
+        int ret;
+        struct journal_head *jh = bh2jh(bh);
+
+        if (ext3_test_bit(nr, bh->b_data))
+                return 0;
+
+        jbd_lock_bh_state(bh);
+        if (!jh->b_committed_data)
+                ret = 1;
+        else
+                ret = !ext3_test_bit(nr, jh->b_committed_data);
+        jbd_unlock_bh_state(bh);
+        return ret;
+}
+
+static int
+bitmap_search_next_usable_block(int start, struct buffer_head *bh,
+                                        int maxblocks)
+{
+        int next;
+        struct journal_head *jh = bh2jh(bh);
+
+        /*
+         * The bitmap search --- search forward alternately through the actual
+         * bitmap and the last-committed copy until we find a bit free in
+         * both
+         */
+        while (start < maxblocks) {
+                next = ext3_find_next_zero_bit(bh->b_data, maxblocks, start);
+                if (next >= maxblocks)
+                        return -1;
+                if (ext3_test_allocatable(next, bh))
+                        return next;
+                jbd_lock_bh_state(bh);
+                if (jh->b_committed_data)
+                        start = ext3_find_next_zero_bit(jh->b_committed_data,
+                                                        maxblocks, next);
+                jbd_unlock_bh_state(bh);
+        }
+        return -1;
+}
+
+/*
+ * Find an allocatable block in a bitmap.  We honour both the bitmap and
+ * its last-committed copy (if that exists), and perform the "most
+ * appropriate allocation" algorithm of looking for a free block near
+ * the initial goal; then for a free byte somewhere in the bitmap; then
+ * for any free bit in the bitmap.
+ */
+static int
+find_next_usable_block(int start, struct buffer_head *bh, int maxblocks)
+{
+        int here, next;
+        char *p, *r;
+
+        if (start > 0) {
+                /*
+                 * The goal was occupied; search forward for a free 
+                 * block within the next XX blocks.
+                 *
+                 * end_goal is more or less random, but it has to be
+                 * less than EXT3_BLOCKS_PER_GROUP. Aligning up to the
+                 * next 64-bit boundary is simple..
+                 */
+                int end_goal = (start + 63) & ~63;
+                if (end_goal > maxblocks)
+                        end_goal = maxblocks;
+                here = ext3_find_next_zero_bit(bh->b_data, end_goal, start);
+                if (here < end_goal && ext3_test_allocatable(here, bh))
+                        return here;
+                ext3_debug("Bit not found near goal\n");
+        }
+
+        here = start;
+        if (here < 0)
+                here = 0;
+
+        p = ((char *)bh->b_data) + (here >> 3);
+        r = memscan(p, 0, (maxblocks - here + 7) >> 3);
+        next = (r - ((char *)bh->b_data)) << 3;
+
+        if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh))
+                return next;
+
+        /*
+         * The bitmap search --- search forward alternately through the actual
+         * bitmap and the last-committed copy until we find a bit free in
+         * both
+         */
+        here = bitmap_search_next_usable_block(here, bh, maxblocks);
+        return here;
+}
+
+/*
+ * We think we can allocate this block in this bitmap.  Try to set the bit.
+ * If that succeeds then check that nobody has allocated and then freed the
+ * block since we saw that is was not marked in b_committed_data.  If it _was_
+ * allocated and freed then clear the bit in the bitmap again and return
+ * zero (failure).
+ */
+static inline int
+claim_block(spinlock_t *lock, int block, struct buffer_head *bh)
+{
+        struct journal_head *jh = bh2jh(bh);
+        int ret;
+
+        if (ext3_set_bit_atomic(lock, block, bh->b_data))
+                return 0;
+        jbd_lock_bh_state(bh);
+        if (jh->b_committed_data && ext3_test_bit(block,jh->b_committed_data)) {
+                ext3_clear_bit_atomic(lock, block, bh->b_data);
+                ret = 0;
+        } else {
+                ret = 1;
+        }
+        jbd_unlock_bh_state(bh);
+        return ret;
+}
+
+/*
+ * If we failed to allocate the desired block then we may end up crossing to a
+ * new bitmap.  In that case we must release write access to the old one via
+ * ext3_journal_release_buffer(), else we'll run out of credits.
+ */
+static int
+ext3_try_to_allocate(struct super_block *sb, handle_t *handle, int group,
+        struct buffer_head *bitmap_bh, int goal, struct ext3_reserve_window *my_rsv)
+{
+        int group_first_block, start, end;
+
+        /* we do allocation within the reservation window if we have a window */
+        if (my_rsv) {
+                group_first_block =
+                        le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
+                        group * EXT3_BLOCKS_PER_GROUP(sb);
+                if (my_rsv->_rsv_start >= group_first_block)
+                        start = my_rsv->_rsv_start - group_first_block;
+                else
+                        /* reservation window cross group boundary */
+                        start = 0;
+                end = my_rsv->_rsv_end - group_first_block + 1;
+                if (end > EXT3_BLOCKS_PER_GROUP(sb))
+                        /* reservation window crosses group boundary */
+                        end = EXT3_BLOCKS_PER_GROUP(sb);
+                if ((start <= goal) && (goal < end))
+                        start = goal;
+                else
+                        goal = -1;
+        } else {
+                if (goal > 0)
+                        start = goal;
+                else
+                        start = 0;
+                end = EXT3_BLOCKS_PER_GROUP(sb);
+        }
+
+        BUG_ON(start > EXT3_BLOCKS_PER_GROUP(sb));
+
+repeat:
+        if (goal < 0 || !ext3_test_allocatable(goal, bitmap_bh)) {
+                goal = find_next_usable_block(start, bitmap_bh, end);
+                if (goal < 0)
+                        goto fail_access;
+                if (!my_rsv) {
+                        int i;
+
+                        for (i = 0; i < 7 && goal > start &&
+                                        ext3_test_allocatable(goal - 1,
+                                                                bitmap_bh);
+                                        i++, goal--)
+                                ;
+                }
+        }
+        start = goal;
+
+        if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group), goal, bitmap_bh)) {
+                /*
+                 * The block was allocated by another thread, or it was
+                 * allocated and then freed by another thread
+                 */
+                start++;
+                goal++;
+                if (start >= end)
+                        goto fail_access;
+                goto repeat;
+        }
+        return goal;
+fail_access:
+        return -1;
+}
+
+/**
+ *      find_next_reservable_window():
+ *              find a reservable space within the given range.
+ *              It does not allocate the reservation window for now:
+ *              alloc_new_reservation() will do the work later.
+ *
+ *      @search_head: the head of the searching list;
+ *              This is not necessarily the list head of the whole filesystem
+ *
+ *              We have both head and start_block to assist the search
+ *              for the reservable space. The list starts from head,
+ *              but we will shift to the place where start_block is,
+ *              then start from there, when looking for a reservable space.
+ *
+ *      @size: the target new reservation window size
+ *
+ *      @group_first_block: the first block we consider to start
+ *                      the real search from
+ *
+ *      @last_block:
+ *              the maximum block number that our goal reservable space
+ *              could start from. This is normally the last block in this
+ *              group. The search will end when we found the start of next
+ *              possible reservable space is out of this boundary.
+ *              This could handle the cross boundary reservation window
+ *              request.
+ *
+ *      basically we search from the given range, rather than the whole
+ *      reservation double linked list, (start_block, last_block)
+ *      to find a free region that is of my size and has not
+ *      been reserved.
+ *
+ *      on succeed, it returns the reservation window to be appended to.
+ *      failed, return NULL.
+ */
+static struct ext3_reserve_window_node *find_next_reservable_window(
+                                struct ext3_reserve_window_node *search_head,
+                                unsigned long size, int *start_block,
+                                int last_block)
+{
+        struct rb_node *next;
+        struct ext3_reserve_window_node *rsv, *prev;
+        int cur;
+
+        /* TODO: make the start of the reservation window byte-aligned */
+        /* cur = *start_block & ~7;*/
+        cur = *start_block;
+        rsv = search_head;
+        if (!rsv)
+                return NULL;
+
+        while (1) {
+                if (cur <= rsv->rsv_end)
+                        cur = rsv->rsv_end + 1;
+
+                /* TODO?
+                 * in the case we could not find a reservable space
+                 * that is what is expected, during the re-search, we could
+                 * remember what's the largest reservable space we could have
+                 * and return that one.
+                 *
+                 * For now it will fail if we could not find the reservable
+                 * space with expected-size (or more)...
+                 */
+                if (cur > last_block)
+                        return NULL;            /* fail */
+
+                prev = rsv;
+                next = rb_next(&rsv->rsv_node);
+                rsv = list_entry(next, struct ext3_reserve_window_node, rsv_node);
+
+                /*
+                 * Reached the last reservation, we can just append to the
+                 * previous one.
+                 */
+                if (!next)
+                        break;
+
+                if (cur + size <= rsv->rsv_start) {
+                        /*
+                         * Found a reserveable space big enough.  We could
+                         * have a reservation across the group boundary here
+                         */
+                        break;
+                }
+        }
+        /*
+         * we come here either :
+         * when we reach the end of the whole list,
+         * and there is empty reservable space after last entry in the list.
+         * append it to the end of the list.
+         *
+         * or we found one reservable space in the middle of the list,
+         * return the reservation window that we could append to.
+         * succeed.
+         */
+        *start_block = cur;
+        return prev;
+}
+
+/**
+ *      alloc_new_reservation()--allocate a new reservation window
+ *
+ *              To make a new reservation, we search part of the filesystem
+ *              reservation list (the list that inside the group). We try to
+ *              allocate a new reservation window near the allocation goal,
+ *              or the beginning of the group, if there is no goal.
+ *
+ *              We first find a reservable space after the goal, then from
+ *              there, we check the bitmap for the first free block after
+ *              it. If there is no free block until the end of group, then the
+ *              whole group is full, we failed. Otherwise, check if the free
+ *              block is inside the expected reservable space, if so, we
+ *              succeed.
+ *              If the first free block is outside the reservable space, then
+ *              start from the first free block, we search for next available
+ *              space, and go on.
+ *
+ *      on succeed, a new reservation will be found and inserted into the list
+ *      It contains at least one free block, and it does not overlap with other
+ *      reservation windows.
+ *
+ *      failed: we failed to find a reservation window in this group
+ *
+ *      @rsv: the reservation
+ *
+ *      @goal: The goal (group-relative).  It is where the search for a
+ *              free reservable space should start from.
+ *              if we have a goal(goal >0 ), then start from there,
+ *              no goal(goal = -1), we start from the first block
+ *              of the group.
+ *
+ *      @sb: the super block
+ *      @group: the group we are trying to allocate in
+ *      @bitmap_bh: the block group block bitmap
+ */
+static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
+                int goal, struct super_block *sb,
+                unsigned int group, struct buffer_head *bitmap_bh)
+{
+        struct ext3_reserve_window_node *search_head;
+        int group_first_block, group_end_block, start_block;
+        int first_free_block;
+        int reservable_space_start;
+        struct ext3_reserve_window_node *prev_rsv;
+        struct rb_root *fs_rsv_root = &EXT3_SB(sb)->s_rsv_window_root;
+        unsigned long size;
+
+        group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
+                                group * EXT3_BLOCKS_PER_GROUP(sb);
+        group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+
+        if (goal < 0)
+                start_block = group_first_block;
+        else
+                start_block = goal + group_first_block;
+
+        size = my_rsv->rsv_goal_size;
+        if (!rsv_is_empty(&my_rsv->rsv_window)) {
+                /*
+                 * if the old reservation is cross group boundary
+                 * and if the goal is inside the old reservation window,
+                 * we will come here when we just failed to allocate from
+                 * the first part of the window. We still have another part
+                 * that belongs to the next group. In this case, there is no
+                 * point to discard our window and try to allocate a new one
+                 * in this group(which will fail). we should
+                 * keep the reservation window, just simply move on.
+                 *
+                 * Maybe we could shift the start block of the reservation
+                 * window to the first block of next group.
+                 */
+
+                if ((my_rsv->rsv_start <= group_end_block) &&
+                                (my_rsv->rsv_end > group_end_block) &&
+                                (start_block >= my_rsv->rsv_start))
+                        return -1;
+
+                if ((my_rsv->rsv_alloc_hit >
+                     (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) {
+                        /*
+                         * if we previously allocation hit ration is greater than half
+                         * we double the size of reservation window next time
+                         * otherwise keep the same
+                         */
+                        size = size * 2;
+                        if (size > EXT3_MAX_RESERVE_BLOCKS)
+                                size = EXT3_MAX_RESERVE_BLOCKS;
+                        my_rsv->rsv_goal_size= size;
+                }
+        }
+        /*
+         * shift the search start to the window near the goal block
+         */
+        search_head = search_reserve_window(fs_rsv_root, start_block);
+
+        /*
+         * find_next_reservable_window() simply finds a reservable window
+         * inside the given range(start_block, group_end_block).
+         *
+         * To make sure the reservation window has a free bit inside it, we
+         * need to check the bitmap after we found a reservable window.
+         */
+retry:
+        prev_rsv = find_next_reservable_window(search_head, size,
+                                                &start_block, group_end_block);
+        if (prev_rsv == NULL)
+                goto failed;
+        reservable_space_start = start_block;
+        /*
+         * On success, find_next_reservable_window() returns the
+         * reservation window where there is a reservable space after it.
+         * Before we reserve this reservable space, we need
+         * to make sure there is at least a free block inside this region.
+         *
+         * searching the first free bit on the block bitmap and copy of
+         * last committed bitmap alternatively, until we found a allocatable
+         * block. Search start from the start block of the reservable space
+         * we just found.
+         */
+        first_free_block = bitmap_search_next_usable_block(
+                        reservable_space_start - group_first_block,
+                        bitmap_bh, group_end_block - group_first_block + 1);
+
+        if (first_free_block < 0) {
+                /*
+                 * no free block left on the bitmap, no point
+                 * to reserve the space. return failed.
+                 */
+                goto failed;
+        }
+        start_block = first_free_block + group_first_block;
+        /*
+         * check if the first free block is within the
+         * free space we just found
+         */
+        if ((start_block >= reservable_space_start) &&
+          (start_block < reservable_space_start + size))
+                goto found_rsv_window;
+        /*
+         * if the first free bit we found is out of the reservable space
+         * this means there is no free block on the reservable space
+         * we should continue search for next reservable space,
+         * start from where the free block is,
+         * we also shift the list head to where we stopped last time
+         */
+        search_head = prev_rsv;
+        goto retry;
+
+found_rsv_window:
+        /*
+         * great! the reservable space contains some free blocks.
+         * if the search returns that we should add the new
+         * window just next to where the old window, we don't
+         * need to remove the old window first then add it to the
+         * same place, just update the new start and new end.
+         */
+        if (my_rsv != prev_rsv)  {
+                if (!rsv_is_empty(&my_rsv->rsv_window))
+                        rsv_window_remove(sb, my_rsv);
+        }
+        my_rsv->rsv_start = reservable_space_start;
+        my_rsv->rsv_end = my_rsv->rsv_start + size - 1;
+        my_rsv->rsv_alloc_hit = 0;
+        if (my_rsv != prev_rsv)  {
+                ext3_rsv_window_add(sb, my_rsv);
+        }
+        return 0;               /* succeed */
+failed:
+        /*
+         * failed to find a new reservation window in the current
+         * group, remove the current(stale) reservation window
+         * if there is any
+         */
+        if (!rsv_is_empty(&my_rsv->rsv_window))
+                rsv_window_remove(sb, my_rsv);
+        return -1;              /* failed */
+}
+
+/*
+ * This is the main function used to allocate a new block and its reservation
+ * window.
+ *
+ * Each time when a new block allocation is need, first try to allocate from
+ * its own reservation.  If it does not have a reservation window, instead of
+ * looking for a free bit on bitmap first, then look up the reservation list to
+ * see if it is inside somebody else's reservation window, we try to allocate a
+ * reservation window for it starting from the goal first. Then do the block
+ * allocation within the reservation window.
+ *
+ * This will avoid keeping on searching the reservation list again and
+ * again when someboday is looking for a free block (without
+ * reservation), and there are lots of free blocks, but they are all
+ * being reserved.
+ *
+ * We use a sorted double linked list for the per-filesystem reservation list.
+ * The insert, remove and find a free space(non-reserved) operations for the
+ * sorted double linked list should be fast.
+ *
+ */
+static int
+ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
+                        unsigned int group, struct buffer_head *bitmap_bh,
+                        int goal, struct ext3_reserve_window_node * my_rsv,
+                        int *errp)
+{
+        spinlock_t *rsv_lock;
+        unsigned long group_first_block;
+        int ret = 0;
+        int fatal;
+
+        *errp = 0;
+
+        /*
+         * Make sure we use undo access for the bitmap, because it is critical
+         * that we do the frozen_data COW on bitmap buffers in all cases even
+         * if the buffer is in BJ_Forget state in the committing transaction.
+         */
+        BUFFER_TRACE(bitmap_bh, "get undo access for new block");
+        fatal = ext3_journal_get_undo_access(handle, bitmap_bh);
+        if (fatal) {
+                *errp = fatal;
+                return -1;
+        }
+
+        /*
+         * we don't deal with reservation when
+         * filesystem is mounted without reservation
+         * or the file is not a regular file
+         * or last attempt to allocate a block with reservation turned on failed
+         */
+        if (my_rsv == NULL ) {
+                ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, NULL);
+                goto out;
+        }
+        rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;
+        /*
+         * goal is a group relative block number (if there is a goal)
+         * 0 < goal < EXT3_BLOCKS_PER_GROUP(sb)
+         * first block is a filesystem wide block number
+         * first block is the block number of the first block in this group
+         */
+        group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
+                        group * EXT3_BLOCKS_PER_GROUP(sb);
+
+        /*
+         * Basically we will allocate a new block from inode's reservation
+         * window.
+         *
+         * We need to allocate a new reservation window, if:
+         * a) inode does not have a reservation window; or
+         * b) last attempt to allocate a block from existing reservation
+         *    failed; or
+         * c) we come here with a goal and with a reservation window
+         *
+         * We do not need to allocate a new reservation window if we come here
+         * at the beginning with a goal and the goal is inside the window, or
+         * we don't have a goal but already have a reservation window.
+         * then we could go to allocate from the reservation window directly.
+         */
+        while (1) {
+                struct ext3_reserve_window rsv_copy;
+
+                rsv_copy._rsv_start = my_rsv->rsv_start;
+                rsv_copy._rsv_end = my_rsv->rsv_end;
+
+                if (rsv_is_empty(&rsv_copy) || (ret < 0) ||
+                        !goal_in_my_reservation(&rsv_copy, goal, group, sb)) {
+                        spin_lock(rsv_lock);
+                        ret = alloc_new_reservation(my_rsv, goal, sb,
+                                                        group, bitmap_bh);
+                        rsv_copy._rsv_start = my_rsv->rsv_start;
+                        rsv_copy._rsv_end = my_rsv->rsv_end;
+                        spin_unlock(rsv_lock);
+                        if (ret < 0)
+                                break;                  /* failed */
+
+                        if (!goal_in_my_reservation(&rsv_copy, goal, group, sb))
+                                goal = -1;
+                }
+                if ((rsv_copy._rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb))
+                    || (rsv_copy._rsv_end < group_first_block))
+                        BUG();
+                ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal,
+                                           &rsv_copy);
+                if (ret >= 0) {
+                        my_rsv->rsv_alloc_hit++;
+                        break;                          /* succeed */
+                }
+        }
+out:
+        if (ret >= 0) {
+                BUFFER_TRACE(bitmap_bh, "journal_dirty_metadata for "
+                                        "bitmap block");
+                fatal = ext3_journal_dirty_metadata(handle, bitmap_bh);
+                if (fatal) {
+                        *errp = fatal;
+                        return -1;
+                }
+                return ret;
+        }
+
+        BUFFER_TRACE(bitmap_bh, "journal_release_buffer");
+        ext3_journal_release_buffer(handle, bitmap_bh);
+        return ret;
+}
+
+static int ext3_has_free_blocks(struct ext3_sb_info *sbi)
+{
+        int free_blocks, root_blocks;
+
+        free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+        root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
+        if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
+                sbi->s_resuid != current->fsuid &&
+                (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
+                return 0;
+        }
+        return 1;
+}
+
+/*
+ * ext3_should_retry_alloc() is called when ENOSPC is returned, and if
+ * it is profitable to retry the operation, this function will wait
+ * for the current or commiting transaction to complete, and then
+ * return TRUE.
+ */
+int ext3_should_retry_alloc(struct super_block *sb, int *retries)
+{
+        if (!ext3_has_free_blocks(EXT3_SB(sb)) || (*retries)++ > 3)
+                return 0;
+
+        jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
+
+        return journal_force_commit_nested(EXT3_SB(sb)->s_journal);
+}
+
+/*
+ * ext3_new_block uses a goal block to assist allocation.  If the goal is
+ * free, or there is a free block within 32 blocks of the goal, that block
+ * is allocated.  Otherwise a forward search is made for a free block; within 
+ * each block group the search first looks for an entire free byte in the block
+ * bitmap, and then for any free bit if that fails.
+ * This function also updates quota and i_blocks field.
+ */
+int ext3_new_block(handle_t *handle, struct inode *inode,
+                        unsigned long goal, int *errp)
+{
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *gdp_bh;
+        int group_no;
+        int goal_group;
+        int ret_block;
+        int bgi;                        /* blockgroup iteration index */
+        int target_block;
+        int fatal = 0, err;
+        int performed_allocation = 0;
+        int free_blocks;
+        struct super_block *sb;
+        struct ext3_group_desc *gdp;
+        struct ext3_super_block *es;
+        struct ext3_sb_info *sbi;
+        struct ext3_reserve_window_node *my_rsv = NULL;
+        struct ext3_block_alloc_info *block_i;
+        unsigned short windowsz = 0;
+#ifdef EXT3FS_DEBUG
+        static int goal_hits, goal_attempts;
+#endif
+        unsigned long ngroups;
+
+        *errp = -ENOSPC;
+        sb = inode->i_sb;
+        if (!sb) {
+                printk("ext3_new_block: nonexistent device");
+                return 0;
+        }
+
+        /*
+         * Check quota for allocation of this block.
+         */
+        if (DQUOT_ALLOC_BLOCK(inode, 1)) {
+                *errp = -EDQUOT;
+                return 0;
+        }
+
+        sbi = EXT3_SB(sb);
+        es = EXT3_SB(sb)->s_es;
+        ext3_debug("goal=%lu.\n", goal);
+        /*
+         * Allocate a block from reservation only when
+         * filesystem is mounted with reservation(default,-o reservation), and
+         * it's a regular file, and
+         * the desired window size is greater than 0 (One could use ioctl
+         * command EXT3_IOC_SETRSVSZ to set the window size to 0 to turn off
+         * reservation on that particular file)
+         */
+        block_i = EXT3_I(inode)->i_block_alloc_info;
+        if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0))
+                my_rsv = &block_i->rsv_window_node;
+
+        if (!ext3_has_free_blocks(sbi)) {
+                *errp = -ENOSPC;
+                goto out;
+        }
+
+        /*
+         * First, test whether the goal block is free.
+         */
+        if (goal < le32_to_cpu(es->s_first_data_block) ||
+            goal >= le32_to_cpu(es->s_blocks_count))
+                goal = le32_to_cpu(es->s_first_data_block);
+        group_no = (goal - le32_to_cpu(es->s_first_data_block)) /
+                        EXT3_BLOCKS_PER_GROUP(sb);
+        gdp = ext3_get_group_desc(sb, group_no, &gdp_bh);
+        if (!gdp)
+                goto io_error;
+
+        goal_group = group_no;
+retry:
+        free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
+        /*
+         * if there is not enough free blocks to make a new resevation
+         * turn off reservation for this allocation
+         */
+        if (my_rsv && (free_blocks < windowsz)
+                && (rsv_is_empty(&my_rsv->rsv_window)))
+                my_rsv = NULL;
+
+        if (free_blocks > 0) {
+                ret_block = ((goal - le32_to_cpu(es->s_first_data_block)) %
+                                EXT3_BLOCKS_PER_GROUP(sb));
+                bitmap_bh = read_block_bitmap(sb, group_no);
+                if (!bitmap_bh)
+                        goto io_error;
+                ret_block = ext3_try_to_allocate_with_rsv(sb, handle, group_no,
+                                        bitmap_bh, ret_block, my_rsv, &fatal);
+                if (fatal)
+                        goto out;
+                if (ret_block >= 0)
+                        goto allocated;
+        }
+
+        ngroups = EXT3_SB(sb)->s_groups_count;
+        smp_rmb();
+
+        /*
+         * Now search the rest of the groups.  We assume that 
+         * i and gdp correctly point to the last group visited.
+         */
+        for (bgi = 0; bgi < ngroups; bgi++) {
+                group_no++;
+                if (group_no >= ngroups)
+                        group_no = 0;
+                gdp = ext3_get_group_desc(sb, group_no, &gdp_bh);
+                if (!gdp) {
+                        *errp = -EIO;
+                        goto out;
+                }
+                free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
+                /*
+                 * skip this group if the number of
+                 * free blocks is less than half of the reservation
+                 * window size.
+                 */
+                if (free_blocks <= (windowsz/2))
+                        continue;
+
+                brelse(bitmap_bh);
+                bitmap_bh = read_block_bitmap(sb, group_no);
+                if (!bitmap_bh)
+                        goto io_error;
+                ret_block = ext3_try_to_allocate_with_rsv(sb, handle, group_no,
+                                        bitmap_bh, -1, my_rsv, &fatal);
+                if (fatal)
+                        goto out;
+                if (ret_block >= 0) 
+                        goto allocated;
+        }
+        /*
+         * We may end up a bogus ealier ENOSPC error due to
+         * filesystem is "full" of reservations, but
+         * there maybe indeed free blocks avaliable on disk
+         * In this case, we just forget about the reservations
+         * just do block allocation as without reservations.
+         */
+        if (my_rsv) {
+                my_rsv = NULL;
+                group_no = goal_group;
+                goto retry;
+        }
+        /* No space left on the device */
+        *errp = -ENOSPC;
+        goto out;
+
+allocated:
+
+        ext3_debug("using block group %d(%d)\n",
+                        group_no, gdp->bg_free_blocks_count);
+
+        BUFFER_TRACE(gdp_bh, "get_write_access");
+        fatal = ext3_journal_get_write_access(handle, gdp_bh);
+        if (fatal)
+                goto out;
+
+        target_block = ret_block + group_no * EXT3_BLOCKS_PER_GROUP(sb)
+                                + le32_to_cpu(es->s_first_data_block);
+
+        if (target_block == le32_to_cpu(gdp->bg_block_bitmap) ||
+            target_block == le32_to_cpu(gdp->bg_inode_bitmap) ||
+            in_range(target_block, le32_to_cpu(gdp->bg_inode_table),
+                      EXT3_SB(sb)->s_itb_per_group))
+                ext3_error(sb, "ext3_new_block",
+                            "Allocating block in system zone - "
+                            "block = %u", target_block);
+
+        performed_allocation = 1;
+
+#ifdef CONFIG_JBD_DEBUG
+        {
+                struct buffer_head *debug_bh;
+
+                /* Record bitmap buffer state in the newly allocated block */
+                debug_bh = sb_find_get_block(sb, target_block);
+                if (debug_bh) {
+                        BUFFER_TRACE(debug_bh, "state when allocated");
+                        BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap state");
+                        brelse(debug_bh);
+                }
+        }
+        jbd_lock_bh_state(bitmap_bh);
+        spin_lock(sb_bgl_lock(sbi, group_no));
+        if (buffer_jbd(bitmap_bh) && bh2jh(bitmap_bh)->b_committed_data) {
+                if (ext3_test_bit(ret_block,
+                                bh2jh(bitmap_bh)->b_committed_data)) {
+                        printk("%s: block was unexpectedly set in "
+                                "b_committed_data\n", __FUNCTION__);
+                }
+        }
+        ext3_debug("found bit %d\n", ret_block);
+        spin_unlock(sb_bgl_lock(sbi, group_no));
+        jbd_unlock_bh_state(bitmap_bh);
+#endif
+
+        /* ret_block was blockgroup-relative.  Now it becomes fs-relative */
+        ret_block = target_block;
+
+        if (ret_block >= le32_to_cpu(es->s_blocks_count)) {
+                ext3_error(sb, "ext3_new_block",
+                            "block(%d) >= blocks count(%d) - "
+                            "block_group = %d, es == %p ", ret_block,
+                        le32_to_cpu(es->s_blocks_count), group_no, es);
+                goto out;
+        }
+
+        /*
+         * It is up to the caller to add the new buffer to a journal
+         * list of some description.  We don't know in advance whether
+         * the caller wants to use it as metadata or data.
+         */
+        ext3_debug("allocating block %d. Goal hits %d of %d.\n",
+                        ret_block, goal_hits, goal_attempts);
+
+        spin_lock(sb_bgl_lock(sbi, group_no));
+        gdp->bg_free_blocks_count =
+                        cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - 1);
+        spin_unlock(sb_bgl_lock(sbi, group_no));
+        percpu_counter_mod(&sbi->s_freeblocks_counter, -1);
+
+        BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor");
+        err = ext3_journal_dirty_metadata(handle, gdp_bh);
+        if (!fatal)
+                fatal = err;
+
+        sb->s_dirt = 1;
+        if (fatal)
+                goto out;
+
+        *errp = 0;
+        brelse(bitmap_bh);
+        return ret_block;
+
+io_error:
+        *errp = -EIO;
+out:
+        if (fatal) {
+                *errp = fatal;
+                ext3_std_error(sb, fatal);
+        }
+        /*
+         * Undo the block allocation
+         */
+        if (!performed_allocation)
+                DQUOT_FREE_BLOCK(inode, 1);
+        brelse(bitmap_bh);
+        return 0;
+}
+
+unsigned long ext3_count_free_blocks(struct super_block *sb)
+{
+        unsigned long desc_count;
+        struct ext3_group_desc *gdp;
+        int i;
+        unsigned long ngroups;
+#ifdef EXT3FS_DEBUG
+        struct ext3_super_block *es;
+        unsigned long bitmap_count, x;
+        struct buffer_head *bitmap_bh = NULL;
+
+        lock_super(sb);
+        es = EXT3_SB(sb)->s_es;
+        desc_count = 0;
+        bitmap_count = 0;
+        gdp = NULL;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc(sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
+                brelse(bitmap_bh);
+                bitmap_bh = read_block_bitmap(sb, i);
+                if (bitmap_bh == NULL)
+                        continue;
+
+                x = ext3_count_free(bitmap_bh, sb->s_blocksize);
+                printk("group %d: stored = %d, counted = %lu\n",
+                        i, le16_to_cpu(gdp->bg_free_blocks_count), x);
+                bitmap_count += x;
+        }
+        brelse(bitmap_bh);
+        printk("ext3_count_free_blocks: stored = %u, computed = %lu, %lu\n",
+               le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count);
+        unlock_super(sb);
+        return bitmap_count;
+#else
+        desc_count = 0;
+        ngroups = EXT3_SB(sb)->s_groups_count;
+        smp_rmb();
+        for (i = 0; i < ngroups; i++) {
+                gdp = ext3_get_group_desc(sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
+        }
+
+        return desc_count;
+#endif
+}
+
+static inline int
+block_in_use(unsigned long block, struct super_block *sb, unsigned char *map)
+{
+        return ext3_test_bit ((block -
+                le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) %
+                         EXT3_BLOCKS_PER_GROUP(sb), map);
+}
+
+static inline int test_root(int a, int b)
+{
+        int num = b;
+
+        while (a > num)
+                num *= b;
+        return num == a;
+}
+
+static int ext3_group_sparse(int group)
+{
+        if (group <= 1)
+                return 1;
+        if (!(group & 1))
+                return 0;
+        return (test_root(group, 7) || test_root(group, 5) ||
+                test_root(group, 3));
+}
+
+/**
+ *      ext3_bg_has_super - number of blocks used by the superblock in group
+ *      @sb: superblock for filesystem
+ *      @group: group number to check
+ *
+ *      Return the number of blocks used by the superblock (primary or backup)
+ *      in this group.  Currently this will be only 0 or 1.
+ */
+int ext3_bg_has_super(struct super_block *sb, int group)
+{
+        if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
+            !ext3_group_sparse(group))
+                return 0;
+        return 1;
+}
+
+/**
+ *      ext3_bg_num_gdb - number of blocks used by the group table in group
+ *      @sb: superblock for filesystem
+ *      @group: group number to check
+ *
+ *      Return the number of blocks used by the group descriptor table
+ *      (primary or backup) in this group.  In the future there may be a
+ *      different number of descriptor blocks in each group.
+ */
+unsigned long ext3_bg_num_gdb(struct super_block *sb, int group)
+{
+        if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
+            !ext3_group_sparse(group))
+                return 0;
+        return EXT3_SB(sb)->s_gdb_count;
+}
+
+#ifdef CONFIG_EXT3_CHECK
+/* Called at mount-time, super-block is locked */
+void ext3_check_blocks_bitmap (struct super_block * sb)
+{
+        struct ext3_super_block *es;
+        unsigned long desc_count, bitmap_count, x, j;
+        unsigned long desc_blocks;
+        struct buffer_head *bitmap_bh = NULL;
+        struct ext3_group_desc *gdp;
+        int i;
+
+        es = EXT3_SB(sb)->s_es;
+        desc_count = 0;
+        bitmap_count = 0;
+        gdp = NULL;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
+                brelse(bitmap_bh);
+                bitmap_bh = read_block_bitmap(sb, i);
+                if (bitmap_bh == NULL)
+                        continue;
+
+                if (ext3_bg_has_super(sb, i) &&
+                                !ext3_test_bit(0, bitmap_bh->b_data))
+                        ext3_error(sb, __FUNCTION__,
+                                   "Superblock in group %d is marked free", i);
+
+                desc_blocks = ext3_bg_num_gdb(sb, i);
+                for (j = 0; j < desc_blocks; j++)
+                        if (!ext3_test_bit(j + 1, bitmap_bh->b_data))
+                                ext3_error(sb, __FUNCTION__,
+                                           "Descriptor block #%ld in group "
+                                           "%d is marked free", j, i);
+
+                if (!block_in_use (le32_to_cpu(gdp->bg_block_bitmap),
+                                                sb, bitmap_bh->b_data))
+                        ext3_error (sb, "ext3_check_blocks_bitmap",
+                                    "Block bitmap for group %d is marked free",
+                                    i);
+
+                if (!block_in_use (le32_to_cpu(gdp->bg_inode_bitmap),
+                                                sb, bitmap_bh->b_data))
+                        ext3_error (sb, "ext3_check_blocks_bitmap",
+                                    "Inode bitmap for group %d is marked free",
+                                    i);
+
+                for (j = 0; j < EXT3_SB(sb)->s_itb_per_group; j++)
+                        if (!block_in_use (le32_to_cpu(gdp->bg_inode_table) + j,
+                                                        sb, bitmap_bh->b_data))
+                                ext3_error (sb, "ext3_check_blocks_bitmap",
+                                            "Block #%d of the inode table in "
+                                            "group %d is marked free", j, i);
+
+                x = ext3_count_free(bitmap_bh, sb->s_blocksize);
+                if (le16_to_cpu(gdp->bg_free_blocks_count) != x)
+                        ext3_error (sb, "ext3_check_blocks_bitmap",
+                                    "Wrong free blocks count for group %d, "
+                                    "stored = %d, counted = %lu", i,
+                                    le16_to_cpu(gdp->bg_free_blocks_count), x);
+                bitmap_count += x;
+        }
+        brelse(bitmap_bh);
+        if (le32_to_cpu(es->s_free_blocks_count) != bitmap_count)
+                ext3_error (sb, "ext3_check_blocks_bitmap",
+                        "Wrong free blocks count in super block, "
+                        "stored = %lu, counted = %lu",
+                        (unsigned long)le32_to_cpu(es->s_free_blocks_count),
+                        bitmap_count);
+}
+#endif
diff --git a/fs/ext3/bitmap.c b/fs/ext3/bitmap.c
new file mode 100644
index 000000000000..6c419b9ab0e8
--- /dev/null
+++ b/fs/ext3/bitmap.c
@@ -0,0 +1,26 @@
+/*
+ *  linux/fs/ext3/bitmap.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include <linux/buffer_head.h>
+
+
+static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
+
+unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
+{
+        unsigned int i;
+        unsigned long sum = 0;
+
+        if (!map) 
+                return (0);
+        for (i = 0; i < numchars; i++)
+                sum += nibblemap[map->b_data[i] & 0xf] +
+                        nibblemap[(map->b_data[i] >> 4) & 0xf];
+        return (sum);
+}
diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c
new file mode 100644
index 000000000000..832867aef3dc
--- /dev/null
+++ b/fs/ext3/dir.c
@@ -0,0 +1,519 @@
+/*
+ *  linux/fs/ext3/dir.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/dir.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3 directory handling functions
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ * Hash Tree Directory indexing (c) 2001  Daniel Phillips
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/rbtree.h>
+
+static unsigned char ext3_filetype_table[] = {
+        DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int ext3_readdir(struct file *, void *, filldir_t);
+static int ext3_dx_readdir(struct file * filp,
+                           void * dirent, filldir_t filldir);
+static int ext3_release_dir (struct inode * inode,
+                                struct file * filp);
+
+struct file_operations ext3_dir_operations = {
+        .llseek         = generic_file_llseek,
+        .read           = generic_read_dir,
+        .readdir        = ext3_readdir,         /* we take BKL. needed?*/
+        .ioctl          = ext3_ioctl,           /* BKL held */
+        .fsync          = ext3_sync_file,       /* BKL held */
+#ifdef CONFIG_EXT3_INDEX
+        .release        = ext3_release_dir,
+#endif
+};
+
+
+static unsigned char get_dtype(struct super_block *sb, int filetype)
+{
+        if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_FILETYPE) ||
+            (filetype >= EXT3_FT_MAX))
+                return DT_UNKNOWN;
+
+        return (ext3_filetype_table[filetype]);
+}
+                               
+
+int ext3_check_dir_entry (const char * function, struct inode * dir,
+                          struct ext3_dir_entry_2 * de,
+                          struct buffer_head * bh,
+                          unsigned long offset)
+{
+        const char * error_msg = NULL;
+        const int rlen = le16_to_cpu(de->rec_len);
+
+        if (rlen < EXT3_DIR_REC_LEN(1))
+                error_msg = "rec_len is smaller than minimal";
+        else if (rlen % 4 != 0)
+                error_msg = "rec_len % 4 != 0";
+        else if (rlen < EXT3_DIR_REC_LEN(de->name_len))
+                error_msg = "rec_len is too small for name_len";
+        else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
+                error_msg = "directory entry across blocks";
+        else if (le32_to_cpu(de->inode) >
+                        le32_to_cpu(EXT3_SB(dir->i_sb)->s_es->s_inodes_count))
+                error_msg = "inode out of bounds";
+
+        if (error_msg != NULL)
+                ext3_error (dir->i_sb, function,
+                        "bad entry in directory #%lu: %s - "
+                        "offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+                        dir->i_ino, error_msg, offset,
+                        (unsigned long) le32_to_cpu(de->inode),
+                        rlen, de->name_len);
+        return error_msg == NULL ? 1 : 0;
+}
+
+static int ext3_readdir(struct file * filp,
+                         void * dirent, filldir_t filldir)
+{
+        int error = 0;
+        unsigned long offset, blk;
+        int i, num, stored;
+        struct buffer_head * bh, * tmp, * bha[16];
+        struct ext3_dir_entry_2 * de;
+        struct super_block * sb;
+        int err;
+        struct inode *inode = filp->f_dentry->d_inode;
+        int ret = 0;
+
+        sb = inode->i_sb;
+
+#ifdef CONFIG_EXT3_INDEX
+        if (EXT3_HAS_COMPAT_FEATURE(inode->i_sb,
+                                    EXT3_FEATURE_COMPAT_DIR_INDEX) &&
+            ((EXT3_I(inode)->i_flags & EXT3_INDEX_FL) ||
+             ((inode->i_size >> sb->s_blocksize_bits) == 1))) {
+                err = ext3_dx_readdir(filp, dirent, filldir);
+                if (err != ERR_BAD_DX_DIR) {
+                        ret = err;
+                        goto out;
+                }
+                /*
+                 * We don't set the inode dirty flag since it's not
+                 * critical that it get flushed back to the disk.
+                 */
+                EXT3_I(filp->f_dentry->d_inode)->i_flags &= ~EXT3_INDEX_FL;
+        }
+#endif
+        stored = 0;
+        bh = NULL;
+        offset = filp->f_pos & (sb->s_blocksize - 1);
+
+        while (!error && !stored && filp->f_pos < inode->i_size) {
+                blk = (filp->f_pos) >> EXT3_BLOCK_SIZE_BITS(sb);
+                bh = ext3_bread(NULL, inode, blk, 0, &err);
+                if (!bh) {
+                        ext3_error (sb, "ext3_readdir",
+                                "directory #%lu contains a hole at offset %lu",
+                                inode->i_ino, (unsigned long)filp->f_pos);
+                        filp->f_pos += sb->s_blocksize - offset;
+                        continue;
+                }
+
+                /*
+                 * Do the readahead
+                 */
+                if (!offset) {
+                        for (i = 16 >> (EXT3_BLOCK_SIZE_BITS(sb) - 9), num = 0;
+                             i > 0; i--) {
+                                tmp = ext3_getblk (NULL, inode, ++blk, 0, &err);
+                                if (tmp && !buffer_uptodate(tmp) &&
+                                                !buffer_locked(tmp))
+                                        bha[num++] = tmp;
+                                else
+                                        brelse (tmp);
+                        }
+                        if (num) {
+                                ll_rw_block (READA, num, bha);
+                                for (i = 0; i < num; i++)
+                                        brelse (bha[i]);
+                        }
+                }
+
+revalidate:
+                /* If the dir block has changed since the last call to
+                 * readdir(2), then we might be pointing to an invalid
+                 * dirent right now.  Scan from the start of the block
+                 * to make sure. */
+                if (filp->f_version != inode->i_version) {
+                        for (i = 0; i < sb->s_blocksize && i < offset; ) {
+                                de = (struct ext3_dir_entry_2 *) 
+                                        (bh->b_data + i);
+                                /* It's too expensive to do a full
+                                 * dirent test each time round this
+                                 * loop, but we do have to test at
+                                 * least that it is non-zero.  A
+                                 * failure will be detected in the
+                                 * dirent test below. */
+                                if (le16_to_cpu(de->rec_len) <
+                                                EXT3_DIR_REC_LEN(1))
+                                        break;
+                                i += le16_to_cpu(de->rec_len);
+                        }
+                        offset = i;
+                        filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
+                                | offset;
+                        filp->f_version = inode->i_version;
+                }
+
+                while (!error && filp->f_pos < inode->i_size 
+                       && offset < sb->s_blocksize) {
+                        de = (struct ext3_dir_entry_2 *) (bh->b_data + offset);
+                        if (!ext3_check_dir_entry ("ext3_readdir", inode, de,
+                                                   bh, offset)) {
+                                /* On error, skip the f_pos to the
+                                   next block. */
+                                filp->f_pos = (filp->f_pos |
+                                                (sb->s_blocksize - 1)) + 1;
+                                brelse (bh);
+                                ret = stored;
+                                goto out;
+                        }
+                        offset += le16_to_cpu(de->rec_len);
+                        if (le32_to_cpu(de->inode)) {
+                                /* We might block in the next section
+                                 * if the data destination is
+                                 * currently swapped out.  So, use a
+                                 * version stamp to detect whether or
+                                 * not the directory has been modified
+                                 * during the copy operation.
+                                 */
+                                unsigned long version = filp->f_version;
+
+                                error = filldir(dirent, de->name,
+                                                de->name_len,
+                                                filp->f_pos,
+                                                le32_to_cpu(de->inode),
+                                                get_dtype(sb, de->file_type));
+                                if (error)
+                                        break;
+                                if (version != filp->f_version)
+                                        goto revalidate;
+                                stored ++;
+                        }
+                        filp->f_pos += le16_to_cpu(de->rec_len);
+                }
+                offset = 0;
+                brelse (bh);
+        }
+out:
+        return ret;
+}
+
+#ifdef CONFIG_EXT3_INDEX
+/*
+ * These functions convert from the major/minor hash to an f_pos
+ * value.
+ * 
+ * Currently we only use major hash numer.  This is unfortunate, but
+ * on 32-bit machines, the same VFS interface is used for lseek and
+ * llseek, so if we use the 64 bit offset, then the 32-bit versions of
+ * lseek/telldir/seekdir will blow out spectacularly, and from within
+ * the ext2 low-level routine, we don't know if we're being called by
+ * a 64-bit version of the system call or the 32-bit version of the
+ * system call.  Worse yet, NFSv2 only allows for a 32-bit readdir
+ * cookie.  Sigh.
+ */
+#define hash2pos(major, minor)  (major >> 1)
+#define pos2maj_hash(pos)       ((pos << 1) & 0xffffffff)
+#define pos2min_hash(pos)       (0)
+
+/*
+ * This structure holds the nodes of the red-black tree used to store
+ * the directory entry in hash order.
+ */
+struct fname {
+        __u32           hash;
+        __u32           minor_hash;
+        struct rb_node  rb_hash; 
+        struct fname    *next;
+        __u32           inode;
+        __u8            name_len;
+        __u8            file_type;
+        char            name[0];
+};
+
+/*
+ * This functoin implements a non-recursive way of freeing all of the
+ * nodes in the red-black tree.
+ */
+static void free_rb_tree_fname(struct rb_root *root)
+{
+        struct rb_node  *n = root->rb_node;
+        struct rb_node  *parent;
+        struct fname    *fname;
+
+        while (n) {
+                /* Do the node's children first */
+                if ((n)->rb_left) {
+                        n = n->rb_left;
+                        continue;
+                }
+                if (n->rb_right) {
+                        n = n->rb_right;
+                        continue;
+                }
+                /*
+                 * The node has no children; free it, and then zero
+                 * out parent's link to it.  Finally go to the
+                 * beginning of the loop and try to free the parent
+                 * node.
+                 */
+                parent = n->rb_parent;
+                fname = rb_entry(n, struct fname, rb_hash);
+                while (fname) {
+                        struct fname * old = fname;
+                        fname = fname->next;
+                        kfree (old);
+                }
+                if (!parent)
+                        root->rb_node = NULL;
+                else if (parent->rb_left == n)
+                        parent->rb_left = NULL;
+                else if (parent->rb_right == n)
+                        parent->rb_right = NULL;
+                n = parent;
+        }
+        root->rb_node = NULL;
+}
+
+
+static struct dir_private_info *create_dir_info(loff_t pos)
+{
+        struct dir_private_info *p;
+
+        p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL);
+        if (!p)
+                return NULL;
+        p->root.rb_node = NULL;
+        p->curr_node = NULL;
+        p->extra_fname = NULL;
+        p->last_pos = 0;
+        p->curr_hash = pos2maj_hash(pos);
+        p->curr_minor_hash = pos2min_hash(pos);
+        p->next_hash = 0;
+        return p;
+}
+
+void ext3_htree_free_dir_info(struct dir_private_info *p)
+{
+        free_rb_tree_fname(&p->root);
+        kfree(p);
+}
+
+/*
+ * Given a directory entry, enter it into the fname rb tree.
+ */
+int ext3_htree_store_dirent(struct file *dir_file, __u32 hash,
+                             __u32 minor_hash,
+                             struct ext3_dir_entry_2 *dirent)
+{
+        struct rb_node **p, *parent = NULL;
+        struct fname * fname, *new_fn;
+        struct dir_private_info *info;
+        int len;
+
+        info = (struct dir_private_info *) dir_file->private_data;
+        p = &info->root.rb_node;
+
+        /* Create and allocate the fname structure */
+        len = sizeof(struct fname) + dirent->name_len + 1;
+        new_fn = kmalloc(len, GFP_KERNEL);
+        if (!new_fn)
+                return -ENOMEM;
+        memset(new_fn, 0, len);
+        new_fn->hash = hash;
+        new_fn->minor_hash = minor_hash;
+        new_fn->inode = le32_to_cpu(dirent->inode);
+        new_fn->name_len = dirent->name_len;
+        new_fn->file_type = dirent->file_type;
+        memcpy(new_fn->name, dirent->name, dirent->name_len);
+        new_fn->name[dirent->name_len] = 0;
+
+        while (*p) {
+                parent = *p;
+                fname = rb_entry(parent, struct fname, rb_hash);
+
+                /*
+                 * If the hash and minor hash match up, then we put
+                 * them on a linked list.  This rarely happens...
+                 */
+                if ((new_fn->hash == fname->hash) &&
+                    (new_fn->minor_hash == fname->minor_hash)) {
+                        new_fn->next = fname->next;
+                        fname->next = new_fn;
+                        return 0;
+                }
+
+                if (new_fn->hash < fname->hash)
+                        p = &(*p)->rb_left;
+                else if (new_fn->hash > fname->hash)
+                        p = &(*p)->rb_right;
+                else if (new_fn->minor_hash < fname->minor_hash)
+                        p = &(*p)->rb_left;
+                else /* if (new_fn->minor_hash > fname->minor_hash) */
+                        p = &(*p)->rb_right;
+        }
+
+        rb_link_node(&new_fn->rb_hash, parent, p);
+        rb_insert_color(&new_fn->rb_hash, &info->root);
+        return 0;
+}
+
+
+
+/*
+ * This is a helper function for ext3_dx_readdir.  It calls filldir
+ * for all entres on the fname linked list.  (Normally there is only
+ * one entry on the linked list, unless there are 62 bit hash collisions.)
+ */
+static int call_filldir(struct file * filp, void * dirent,
+                        filldir_t filldir, struct fname *fname)
+{
+        struct dir_private_info *info = filp->private_data;
+        loff_t  curr_pos;
+        struct inode *inode = filp->f_dentry->d_inode;
+        struct super_block * sb;
+        int error;
+
+        sb = inode->i_sb;
+
+        if (!fname) {
+                printk("call_filldir: called with null fname?!?\n");
+                return 0;
+        }
+        curr_pos = hash2pos(fname->hash, fname->minor_hash);
+        while (fname) {
+                error = filldir(dirent, fname->name,
+                                fname->name_len, curr_pos, 
+                                fname->inode,
+                                get_dtype(sb, fname->file_type));
+                if (error) {
+                        filp->f_pos = curr_pos;
+                        info->extra_fname = fname->next;
+                        return error;
+                }
+                fname = fname->next;
+        }
+        return 0;
+}
+
+static int ext3_dx_readdir(struct file * filp,
+                         void * dirent, filldir_t filldir)
+{
+        struct dir_private_info *info = filp->private_data;
+        struct inode *inode = filp->f_dentry->d_inode;
+        struct fname *fname;
+        int     ret;
+
+        if (!info) {
+                info = create_dir_info(filp->f_pos);
+                if (!info)
+                        return -ENOMEM;
+                filp->private_data = info;
+        }
+
+        if (filp->f_pos == EXT3_HTREE_EOF)
+                return 0;       /* EOF */
+
+        /* Some one has messed with f_pos; reset the world */
+        if (info->last_pos != filp->f_pos) {
+                free_rb_tree_fname(&info->root);
+                info->curr_node = NULL;
+                info->extra_fname = NULL;
+                info->curr_hash = pos2maj_hash(filp->f_pos);
+                info->curr_minor_hash = pos2min_hash(filp->f_pos);
+        }
+
+        /*
+         * If there are any leftover names on the hash collision
+         * chain, return them first.
+         */
+        if (info->extra_fname &&
+            call_filldir(filp, dirent, filldir, info->extra_fname))
+                goto finished;
+
+        if (!info->curr_node)
+                info->curr_node = rb_first(&info->root);
+
+        while (1) {
+                /*
+                 * Fill the rbtree if we have no more entries,
+                 * or the inode has changed since we last read in the
+                 * cached entries. 
+                 */
+                if ((!info->curr_node) ||
+                    (filp->f_version != inode->i_version)) {
+                        info->curr_node = NULL;
+                        free_rb_tree_fname(&info->root);
+                        filp->f_version = inode->i_version;
+                        ret = ext3_htree_fill_tree(filp, info->curr_hash,
+                                                   info->curr_minor_hash,
+                                                   &info->next_hash);
+                        if (ret < 0)
+                                return ret;
+                        if (ret == 0) {
+                                filp->f_pos = EXT3_HTREE_EOF;
+                                break;
+                        }
+                        info->curr_node = rb_first(&info->root);
+                }
+
+                fname = rb_entry(info->curr_node, struct fname, rb_hash);
+                info->curr_hash = fname->hash;
+                info->curr_minor_hash = fname->minor_hash;
+                if (call_filldir(filp, dirent, filldir, fname))
+                        break;
+
+                info->curr_node = rb_next(info->curr_node);
+                if (!info->curr_node) {
+                        if (info->next_hash == ~0) {
+                                filp->f_pos = EXT3_HTREE_EOF;
+                                break;
+                        }
+                        info->curr_hash = info->next_hash;
+                        info->curr_minor_hash = 0;
+                }
+        }
+finished:
+        info->last_pos = filp->f_pos;
+        return 0;
+}
+
+static int ext3_release_dir (struct inode * inode, struct file * filp)
+{
+       if (filp->private_data)
+                ext3_htree_free_dir_info(filp->private_data);
+
+        return 0;
+}
+
+#endif
diff --git a/fs/ext3/file.c b/fs/ext3/file.c
new file mode 100644
index 000000000000..5ad8cf0292df
--- /dev/null
+++ b/fs/ext3/file.c
@@ -0,0 +1,131 @@
+/*
+ *  linux/fs/ext3/file.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/file.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3 fs regular file handling primitives
+ *
+ *  64-bit file support on 64-bit platforms by Jakub Jelinek
+ *      (jj@sunsite.ms.mff.cuni.cz)
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Called when an inode is released. Note that this is different
+ * from ext3_file_open: open gets called at every open, but release
+ * gets called only when /all/ the files are closed.
+ */
+static int ext3_release_file (struct inode * inode, struct file * filp)
+{
+        /* if we are the last writer on the inode, drop the block reservation */
+        if ((filp->f_mode & FMODE_WRITE) &&
+                        (atomic_read(&inode->i_writecount) == 1))
+                ext3_discard_reservation(inode);
+        if (is_dx(inode) && filp->private_data)
+                ext3_htree_free_dir_info(filp->private_data);
+
+        return 0;
+}
+
+static ssize_t
+ext3_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
+{
+        struct file *file = iocb->ki_filp;
+        struct inode *inode = file->f_dentry->d_inode;
+        ssize_t ret;
+        int err;
+
+        ret = generic_file_aio_write(iocb, buf, count, pos);
+
+        /*
+         * Skip flushing if there was an error, or if nothing was written.
+         */
+        if (ret <= 0)
+                return ret;
+
+        /*
+         * If the inode is IS_SYNC, or is O_SYNC and we are doing data
+         * journalling then we need to make sure that we force the transaction
+         * to disk to keep all metadata uptodate synchronously.
+         */
+        if (file->f_flags & O_SYNC) {
+                /*
+                 * If we are non-data-journaled, then the dirty data has
+                 * already been flushed to backing store by generic_osync_inode,
+                 * and the inode has been flushed too if there have been any
+                 * modifications other than mere timestamp updates.
+                 *
+                 * Open question --- do we care about flushing timestamps too
+                 * if the inode is IS_SYNC?
+                 */
+                if (!ext3_should_journal_data(inode))
+                        return ret;
+
+                goto force_commit;
+        }
+
+        /*
+         * So we know that there has been no forced data flush.  If the inode
+         * is marked IS_SYNC, we need to force one ourselves.
+         */
+        if (!IS_SYNC(inode))
+                return ret;
+
+        /*
+         * Open question #2 --- should we force data to disk here too?  If we
+         * don't, the only impact is that data=writeback filesystems won't
+         * flush data to disk automatically on IS_SYNC, only metadata (but
+         * historically, that is what ext2 has done.)
+         */
+
+force_commit:
+        err = ext3_force_commit(inode->i_sb);
+        if (err) 
+                return err;
+        return ret;
+}
+
+struct file_operations ext3_file_operations = {
+        .llseek         = generic_file_llseek,
+        .read           = do_sync_read,
+        .write          = do_sync_write,
+        .aio_read       = generic_file_aio_read,
+        .aio_write      = ext3_file_write,
+        .readv          = generic_file_readv,
+        .writev         = generic_file_writev,
+        .ioctl          = ext3_ioctl,
+        .mmap           = generic_file_mmap,
+        .open           = generic_file_open,
+        .release        = ext3_release_file,
+        .fsync          = ext3_sync_file,
+        .sendfile       = generic_file_sendfile,
+};
+
+struct inode_operations ext3_file_inode_operations = {
+        .truncate       = ext3_truncate,
+        .setattr        = ext3_setattr,
+#ifdef CONFIG_EXT3_FS_XATTR
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
+        .listxattr      = ext3_listxattr,
+        .removexattr    = generic_removexattr,
+#endif
+        .permission     = ext3_permission,
+};
+
diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c
new file mode 100644
index 000000000000..49382a208e05
--- /dev/null
+++ b/fs/ext3/fsync.c
@@ -0,0 +1,88 @@
+/*
+ *  linux/fs/ext3/fsync.c
+ *
+ *  Copyright (C) 1993  Stephen Tweedie (sct@redhat.com)
+ *  from
+ *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
+ *                      Laboratoire MASI - Institut Blaise Pascal
+ *                      Universite Pierre et Marie Curie (Paris VI)
+ *  from
+ *  linux/fs/minix/truncate.c   Copyright (C) 1991, 1992  Linus Torvalds
+ * 
+ *  ext3fs fsync primitive
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ * 
+ *  Removed unnecessary code duplication for little endian machines
+ *  and excessive __inline__s. 
+ *        Andi Kleen, 1997
+ *
+ * Major simplications and cleanup - we only need to do the metadata, because
+ * we can depend on generic_block_fdatasync() to sync the data blocks.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/writeback.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+
+/*
+ * akpm: A new design for ext3_sync_file().
+ *
+ * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
+ * There cannot be a transaction open by this task.
+ * Another task could have dirtied this inode.  Its data can be in any
+ * state in the journalling system.
+ *
+ * What we do is just kick off a commit and wait on it.  This will snapshot the
+ * inode to disk.
+ */
+
+int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync)
+{
+        struct inode *inode = dentry->d_inode;
+        int ret = 0;
+
+        J_ASSERT(ext3_journal_current_handle() == 0);
+
+        /*
+         * data=writeback:
+         *  The caller's filemap_fdatawrite()/wait will sync the data.
+         *  sync_inode() will sync the metadata
+         *
+         * data=ordered:
+         *  The caller's filemap_fdatawrite() will write the data and
+         *  sync_inode() will write the inode if it is dirty.  Then the caller's
+         *  filemap_fdatawait() will wait on the pages.
+         *
+         * data=journal:
+         *  filemap_fdatawrite won't do anything (the buffers are clean).
+         *  ext3_force_commit will write the file data into the journal and
+         *  will wait on that.
+         *  filemap_fdatawait() will encounter a ton of newly-dirtied pages
+         *  (they were dirtied by commit).  But that's OK - the blocks are
+         *  safe in-journal, which is all fsync() needs to ensure.
+         */
+        if (ext3_should_journal_data(inode)) {
+                ret = ext3_force_commit(inode->i_sb);
+                goto out;
+        }
+
+        /*
+         * The VFS has written the file data.  If the inode is unaltered
+         * then we need not start a commit.
+         */
+        if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) {
+                struct writeback_control wbc = {
+                        .sync_mode = WB_SYNC_ALL,
+                        .nr_to_write = 0, /* sys_fsync did this */
+                };
+                ret = sync_inode(inode, &wbc);
+        }
+out:
+        return ret;
+}
diff --git a/fs/ext3/hash.c b/fs/ext3/hash.c
new file mode 100644
index 000000000000..5a2d1235ead0
--- /dev/null
+++ b/fs/ext3/hash.c
@@ -0,0 +1,152 @@
+/*
+ *  linux/fs/ext3/hash.c
+ *
+ * Copyright (C) 2002 by Theodore Ts'o
+ *
+ * This file is released under the GPL v2.
+ * 
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/sched.h>
+#include <linux/ext3_fs.h>
+#include <linux/cryptohash.h>
+
+#define DELTA 0x9E3779B9
+
+static void TEA_transform(__u32 buf[4], __u32 const in[])
+{
+        __u32   sum = 0;
+        __u32   b0 = buf[0], b1 = buf[1];
+        __u32   a = in[0], b = in[1], c = in[2], d = in[3];
+        int     n = 16;
+
+        do {
+                sum += DELTA;
+                b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
+                b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
+        } while(--n);
+
+        buf[0] += b0;
+        buf[1] += b1;
+}
+
+
+/* The old legacy hash */
+static __u32 dx_hack_hash (const char *name, int len)
+{
+        __u32 hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9;
+        while (len--) {
+                __u32 hash = hash1 + (hash0 ^ (*name++ * 7152373));
+
+                if (hash & 0x80000000) hash -= 0x7fffffff;
+                hash1 = hash0;
+                hash0 = hash;
+        }
+        return (hash0 << 1);
+}
+
+static void str2hashbuf(const char *msg, int len, __u32 *buf, int num)
+{
+        __u32   pad, val;
+        int     i;
+
+        pad = (__u32)len | ((__u32)len << 8);
+        pad |= pad << 16;
+
+        val = pad;
+        if (len > num*4)
+                len = num * 4;
+        for (i=0; i < len; i++) {
+                if ((i % 4) == 0)
+                        val = pad;
+                val = msg[i] + (val << 8);
+                if ((i % 4) == 3) {
+                        *buf++ = val;
+                        val = pad;
+                        num--;
+                }
+        }
+        if (--num >= 0)
+                *buf++ = val;
+        while (--num >= 0)
+                *buf++ = pad;
+}
+
+/*
+ * Returns the hash of a filename.  If len is 0 and name is NULL, then
+ * this function can be used to test whether or not a hash version is
+ * supported.
+ * 
+ * The seed is an 4 longword (32 bits) "secret" which can be used to
+ * uniquify a hash.  If the seed is all zero's, then some default seed
+ * may be used.
+ * 
+ * A particular hash version specifies whether or not the seed is
+ * represented, and whether or not the returned hash is 32 bits or 64
+ * bits.  32 bit hashes will return 0 for the minor hash.
+ */
+int ext3fs_dirhash(const char *name, int len, struct dx_hash_info *hinfo)
+{
+        __u32   hash;
+        __u32   minor_hash = 0;
+        const char      *p;
+        int             i;
+        __u32           in[8], buf[4];
+
+        /* Initialize the default seed for the hash checksum functions */
+        buf[0] = 0x67452301;
+        buf[1] = 0xefcdab89;
+        buf[2] = 0x98badcfe;
+        buf[3] = 0x10325476;
+
+        /* Check to see if the seed is all zero's */
+        if (hinfo->seed) {
+                for (i=0; i < 4; i++) {
+                        if (hinfo->seed[i])
+                                break;
+                }
+                if (i < 4)
+                        memcpy(buf, hinfo->seed, sizeof(buf));
+        }
+
+        switch (hinfo->hash_version) {
+        case DX_HASH_LEGACY:
+                hash = dx_hack_hash(name, len);
+                break;
+        case DX_HASH_HALF_MD4:
+                p = name;
+                while (len > 0) {
+                        str2hashbuf(p, len, in, 8);
+                        half_md4_transform(buf, in);
+                        len -= 32;
+                        p += 32;
+                }
+                minor_hash = buf[2];
+                hash = buf[1];
+                break;
+        case DX_HASH_TEA:
+                p = name;
+                while (len > 0) {
+                        str2hashbuf(p, len, in, 4);
+                        TEA_transform(buf, in);
+                        len -= 16;
+                        p += 16;
+                }
+                hash = buf[0];
+                minor_hash = buf[1];
+                break;
+        default:
+                hinfo->hash = 0;
+                return -1;
+        }
+        hash = hash & ~1;
+        if (hash == (EXT3_HTREE_EOF << 1))
+                hash = (EXT3_HTREE_EOF-1) << 1;
+        hinfo->hash = hash;
+        hinfo->minor_hash = minor_hash;
+        return 0;
+}
diff --git a/fs/ext3/ialloc.c b/fs/ext3/ialloc.c
new file mode 100644
index 000000000000..1e6f3ea28713
--- /dev/null
+++ b/fs/ext3/ialloc.c
@@ -0,0 +1,794 @@
+/*
+ *  linux/fs/ext3/ialloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  BSD ufs-inspired inode and directory allocation by
+ *  Stephen Tweedie (sct@redhat.com), 1993
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+
+#include <asm/byteorder.h>
+
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * ialloc.c contains the inodes allocation and deallocation routines
+ */
+
+/*
+ * The free inodes are managed by bitmaps.  A file system contains several
+ * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block.  Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block.
+ */
+
+
+/*
+ * Read the inode allocation bitmap for a given block_group, reading
+ * into the specified slot in the superblock's bitmap cache.
+ *
+ * Return buffer_head of bitmap on success or NULL.
+ */
+static struct buffer_head *
+read_inode_bitmap(struct super_block * sb, unsigned long block_group)
+{
+        struct ext3_group_desc *desc;
+        struct buffer_head *bh = NULL;
+
+        desc = ext3_get_group_desc(sb, block_group, NULL);
+        if (!desc)
+                goto error_out;
+
+        bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
+        if (!bh)
+                ext3_error(sb, "read_inode_bitmap",
+                            "Cannot read inode bitmap - "
+                            "block_group = %lu, inode_bitmap = %u",
+                            block_group, le32_to_cpu(desc->bg_inode_bitmap));
+error_out:
+        return bh;
+}
+
+/*
+ * NOTE! When we get the inode, we're the only people
+ * that have access to it, and as such there are no
+ * race conditions we have to worry about. The inode
+ * is not on the hash-lists, and it cannot be reached
+ * through the filesystem because the directory entry
+ * has been deleted earlier.
+ *
+ * HOWEVER: we must make sure that we get no aliases,
+ * which means that we have to call "clear_inode()"
+ * _before_ we mark the inode not in use in the inode
+ * bitmaps. Otherwise a newly created file might use
+ * the same inode number (not actually the same pointer
+ * though), and then we'd have two inodes sharing the
+ * same inode number and space on the harddisk.
+ */
+void ext3_free_inode (handle_t *handle, struct inode * inode)
+{
+        struct super_block * sb = inode->i_sb;
+        int is_directory;
+        unsigned long ino;
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *bh2;
+        unsigned long block_group;
+        unsigned long bit;
+        struct ext3_group_desc * gdp;
+        struct ext3_super_block * es;
+        struct ext3_sb_info *sbi;
+        int fatal = 0, err;
+
+        if (atomic_read(&inode->i_count) > 1) {
+                printk ("ext3_free_inode: inode has count=%d\n",
+                                        atomic_read(&inode->i_count));
+                return;
+        }
+        if (inode->i_nlink) {
+                printk ("ext3_free_inode: inode has nlink=%d\n",
+                        inode->i_nlink);
+                return;
+        }
+        if (!sb) {
+                printk("ext3_free_inode: inode on nonexistent device\n");
+                return;
+        }
+        sbi = EXT3_SB(sb);
+
+        ino = inode->i_ino;
+        ext3_debug ("freeing inode %lu\n", ino);
+
+        /*
+         * Note: we must free any quota before locking the superblock,
+         * as writing the quota to disk may need the lock as well.
+         */
+        DQUOT_INIT(inode);
+        ext3_xattr_delete_inode(handle, inode);
+        DQUOT_FREE_INODE(inode);
+        DQUOT_DROP(inode);
+
+        is_directory = S_ISDIR(inode->i_mode);
+
+        /* Do this BEFORE marking the inode not in use or returning an error */
+        clear_inode (inode);
+
+        es = EXT3_SB(sb)->s_es;
+        if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+                ext3_error (sb, "ext3_free_inode",
+                            "reserved or nonexistent inode %lu", ino);
+                goto error_return;
+        }
+        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
+        bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
+        bitmap_bh = read_inode_bitmap(sb, block_group);
+        if (!bitmap_bh)
+                goto error_return;
+
+        BUFFER_TRACE(bitmap_bh, "get_write_access");
+        fatal = ext3_journal_get_write_access(handle, bitmap_bh);
+        if (fatal)
+                goto error_return;
+
+        /* Ok, now we can actually update the inode bitmaps.. */
+        if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
+                                        bit, bitmap_bh->b_data))
+                ext3_error (sb, "ext3_free_inode",
+                              "bit already cleared for inode %lu", ino);
+        else {
+                gdp = ext3_get_group_desc (sb, block_group, &bh2);
+
+                BUFFER_TRACE(bh2, "get_write_access");
+                fatal = ext3_journal_get_write_access(handle, bh2);
+                if (fatal) goto error_return;
+
+                if (gdp) {
+                        spin_lock(sb_bgl_lock(sbi, block_group));
+                        gdp->bg_free_inodes_count = cpu_to_le16(
+                                le16_to_cpu(gdp->bg_free_inodes_count) + 1);
+                        if (is_directory)
+                                gdp->bg_used_dirs_count = cpu_to_le16(
+                                  le16_to_cpu(gdp->bg_used_dirs_count) - 1);
+                        spin_unlock(sb_bgl_lock(sbi, block_group));
+                        percpu_counter_inc(&sbi->s_freeinodes_counter);
+                        if (is_directory)
+                                percpu_counter_dec(&sbi->s_dirs_counter);
+
+                }
+                BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
+                err = ext3_journal_dirty_metadata(handle, bh2);
+                if (!fatal) fatal = err;
+        }
+        BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata");
+        err = ext3_journal_dirty_metadata(handle, bitmap_bh);
+        if (!fatal)
+                fatal = err;
+        sb->s_dirt = 1;
+error_return:
+        brelse(bitmap_bh);
+        ext3_std_error(sb, fatal);
+}
+
+/*
+ * There are two policies for allocating an inode.  If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory\'s block
+ * group to find a free inode.
+ */
+static int find_group_dir(struct super_block *sb, struct inode *parent)
+{
+        int ngroups = EXT3_SB(sb)->s_groups_count;
+        int freei, avefreei;
+        struct ext3_group_desc *desc, *best_desc = NULL;
+        struct buffer_head *bh;
+        int group, best_group = -1;
+
+        freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
+        avefreei = freei / ngroups;
+
+        for (group = 0; group < ngroups; group++) {
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (!desc || !desc->bg_free_inodes_count)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+                        continue;
+                if (!best_desc || 
+                    (le16_to_cpu(desc->bg_free_blocks_count) >
+                     le16_to_cpu(best_desc->bg_free_blocks_count))) {
+                        best_group = group;
+                        best_desc = desc;
+                }
+        }
+        return best_group;
+}
+
+/* 
+ * Orlov's allocator for directories. 
+ * 
+ * We always try to spread first-level directories.
+ *
+ * If there are blockgroups with both free inodes and free blocks counts 
+ * not worse than average we return one with smallest directory count. 
+ * Otherwise we simply return a random group. 
+ * 
+ * For the rest rules look so: 
+ * 
+ * It's OK to put directory into a group unless 
+ * it has too many directories already (max_dirs) or 
+ * it has too few free inodes left (min_inodes) or 
+ * it has too few free blocks left (min_blocks) or 
+ * it's already running too large debt (max_debt). 
+ * Parent's group is prefered, if it doesn't satisfy these 
+ * conditions we search cyclically through the rest. If none 
+ * of the groups look good we just look for a group with more 
+ * free inodes than average (starting at parent's group). 
+ * 
+ * Debt is incremented each time we allocate a directory and decremented 
+ * when we allocate an inode, within 0--255. 
+ */ 
+
+#define INODE_COST 64
+#define BLOCK_COST 256
+
+static int find_group_orlov(struct super_block *sb, struct inode *parent)
+{
+        int parent_group = EXT3_I(parent)->i_block_group;
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        struct ext3_super_block *es = sbi->s_es;
+        int ngroups = sbi->s_groups_count;
+        int inodes_per_group = EXT3_INODES_PER_GROUP(sb);
+        int freei, avefreei;
+        int freeb, avefreeb;
+        int blocks_per_dir, ndirs;
+        int max_debt, max_dirs, min_blocks, min_inodes;
+        int group = -1, i;
+        struct ext3_group_desc *desc;
+        struct buffer_head *bh;
+
+        freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
+        avefreei = freei / ngroups;
+        freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+        avefreeb = freeb / ngroups;
+        ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
+
+        if ((parent == sb->s_root->d_inode) ||
+            (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
+                int best_ndir = inodes_per_group;
+                int best_group = -1;
+
+                get_random_bytes(&group, sizeof(group));
+                parent_group = (unsigned)group % ngroups;
+                for (i = 0; i < ngroups; i++) {
+                        group = (parent_group + i) % ngroups;
+                        desc = ext3_get_group_desc (sb, group, &bh);
+                        if (!desc || !desc->bg_free_inodes_count)
+                                continue;
+                        if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
+                                continue;
+                        if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+                                continue;
+                        if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
+                                continue;
+                        best_group = group;
+                        best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
+                }
+                if (best_group >= 0)
+                        return best_group;
+                goto fallback;
+        }
+
+        blocks_per_dir = (le32_to_cpu(es->s_blocks_count) - freeb) / ndirs;
+
+        max_dirs = ndirs / ngroups + inodes_per_group / 16;
+        min_inodes = avefreei - inodes_per_group / 4;
+        min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4;
+
+        max_debt = EXT3_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
+        if (max_debt * INODE_COST > inodes_per_group)
+                max_debt = inodes_per_group / INODE_COST;
+        if (max_debt > 255)
+                max_debt = 255;
+        if (max_debt == 0)
+                max_debt = 1;
+
+        for (i = 0; i < ngroups; i++) {
+                group = (parent_group + i) % ngroups;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (!desc || !desc->bg_free_inodes_count)
+                        continue;
+                if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
+                        continue;
+                return group;
+        }
+
+fallback:
+        for (i = 0; i < ngroups; i++) {
+                group = (parent_group + i) % ngroups;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (!desc || !desc->bg_free_inodes_count)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
+                        return group;
+        }
+
+        if (avefreei) {
+                /*
+                 * The free-inodes counter is approximate, and for really small
+                 * filesystems the above test can fail to find any blockgroups
+                 */
+                avefreei = 0;
+                goto fallback;
+        }
+
+        return -1;
+}
+
+static int find_group_other(struct super_block *sb, struct inode *parent)
+{
+        int parent_group = EXT3_I(parent)->i_block_group;
+        int ngroups = EXT3_SB(sb)->s_groups_count;
+        struct ext3_group_desc *desc;
+        struct buffer_head *bh;
+        int group, i;
+
+        /*
+         * Try to place the inode in its parent directory
+         */
+        group = parent_group;
+        desc = ext3_get_group_desc (sb, group, &bh);
+        if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+                        le16_to_cpu(desc->bg_free_blocks_count))
+                return group;
+
+        /*
+         * We're going to place this inode in a different blockgroup from its
+         * parent.  We want to cause files in a common directory to all land in
+         * the same blockgroup.  But we want files which are in a different
+         * directory which shares a blockgroup with our parent to land in a
+         * different blockgroup.
+         *
+         * So add our directory's i_ino into the starting point for the hash.
+         */
+        group = (group + parent->i_ino) % ngroups;
+
+        /*
+         * Use a quadratic hash to find a group with a free inode and some free
+         * blocks.
+         */
+        for (i = 1; i < ngroups; i <<= 1) {
+                group += i;
+                if (group >= ngroups)
+                        group -= ngroups;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+                                le16_to_cpu(desc->bg_free_blocks_count))
+                        return group;
+        }
+
+        /*
+         * That failed: try linear search for a free inode, even if that group
+         * has no free blocks.
+         */
+        group = parent_group;
+        for (i = 0; i < ngroups; i++) {
+                if (++group >= ngroups)
+                        group = 0;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (desc && le16_to_cpu(desc->bg_free_inodes_count))
+                        return group;
+        }
+
+        return -1;
+}
+
+/*
+ * There are two policies for allocating an inode.  If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory's block
+ * group to find a free inode.
+ */
+struct inode *ext3_new_inode(handle_t *handle, struct inode * dir, int mode)
+{
+        struct super_block *sb;
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *bh2;
+        int group;
+        unsigned long ino = 0;
+        struct inode * inode;
+        struct ext3_group_desc * gdp = NULL;
+        struct ext3_super_block * es;
+        struct ext3_inode_info *ei;
+        struct ext3_sb_info *sbi;
+        int err = 0;
+        struct inode *ret;
+        int i;
+
+        /* Cannot create files in a deleted directory */
+        if (!dir || !dir->i_nlink)
+                return ERR_PTR(-EPERM);
+
+        sb = dir->i_sb;
+        inode = new_inode(sb);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+        ei = EXT3_I(inode);
+
+        sbi = EXT3_SB(sb);
+        es = sbi->s_es;
+        if (S_ISDIR(mode)) {
+                if (test_opt (sb, OLDALLOC))
+                        group = find_group_dir(sb, dir);
+                else
+                        group = find_group_orlov(sb, dir);
+        } else 
+                group = find_group_other(sb, dir);
+
+        err = -ENOSPC;
+        if (group == -1)
+                goto out;
+
+        for (i = 0; i < sbi->s_groups_count; i++) {
+                err = -EIO;
+
+                gdp = ext3_get_group_desc(sb, group, &bh2);
+                if (!gdp)
+                        goto fail;
+
+                brelse(bitmap_bh);
+                bitmap_bh = read_inode_bitmap(sb, group);
+                if (!bitmap_bh)
+                        goto fail;
+
+                ino = 0;
+
+repeat_in_this_group:
+                ino = ext3_find_next_zero_bit((unsigned long *)
+                                bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino);
+                if (ino < EXT3_INODES_PER_GROUP(sb)) {
+
+                        BUFFER_TRACE(bitmap_bh, "get_write_access");
+                        err = ext3_journal_get_write_access(handle, bitmap_bh);
+                        if (err)
+                                goto fail;
+
+                        if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group),
+                                                ino, bitmap_bh->b_data)) {
+                                /* we won it */
+                                BUFFER_TRACE(bitmap_bh,
+                                        "call ext3_journal_dirty_metadata");
+                                err = ext3_journal_dirty_metadata(handle,
+                                                                bitmap_bh);
+                                if (err)
+                                        goto fail;
+                                goto got;
+                        }
+                        /* we lost it */
+                        journal_release_buffer(handle, bitmap_bh);
+
+                        if (++ino < EXT3_INODES_PER_GROUP(sb))
+                                goto repeat_in_this_group;
+                }
+
+                /*
+                 * This case is possible in concurrent environment.  It is very
+                 * rare.  We cannot repeat the find_group_xxx() call because
+                 * that will simply return the same blockgroup, because the
+                 * group descriptor metadata has not yet been updated.
+                 * So we just go onto the next blockgroup.
+                 */
+                if (++group == sbi->s_groups_count)
+                        group = 0;
+        }
+        err = -ENOSPC;
+        goto out;
+
+got:
+        ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
+        if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+                ext3_error (sb, "ext3_new_inode",
+                            "reserved inode or inode > inodes count - "
+                            "block_group = %d, inode=%lu", group, ino);
+                err = -EIO;
+                goto fail;
+        }
+
+        BUFFER_TRACE(bh2, "get_write_access");
+        err = ext3_journal_get_write_access(handle, bh2);
+        if (err) goto fail;
+        spin_lock(sb_bgl_lock(sbi, group));
+        gdp->bg_free_inodes_count =
+                cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
+        if (S_ISDIR(mode)) {
+                gdp->bg_used_dirs_count =
+                        cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
+        }
+        spin_unlock(sb_bgl_lock(sbi, group));
+        BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
+        err = ext3_journal_dirty_metadata(handle, bh2);
+        if (err) goto fail;
+
+        percpu_counter_dec(&sbi->s_freeinodes_counter);
+        if (S_ISDIR(mode))
+                percpu_counter_inc(&sbi->s_dirs_counter);
+        sb->s_dirt = 1;
+
+        inode->i_uid = current->fsuid;
+        if (test_opt (sb, GRPID))
+                inode->i_gid = dir->i_gid;
+        else if (dir->i_mode & S_ISGID) {
+                inode->i_gid = dir->i_gid;
+                if (S_ISDIR(mode))
+                        mode |= S_ISGID;
+        } else
+                inode->i_gid = current->fsgid;
+        inode->i_mode = mode;
+
+        inode->i_ino = ino;
+        /* This is the optimal IO size (for stat), not the fs block size */
+        inode->i_blksize = PAGE_SIZE;
+        inode->i_blocks = 0;
+        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+
+        memset(ei->i_data, 0, sizeof(ei->i_data));
+        ei->i_dir_start_lookup = 0;
+        ei->i_disksize = 0;
+
+        ei->i_flags = EXT3_I(dir)->i_flags & ~EXT3_INDEX_FL;
+        if (S_ISLNK(mode))
+                ei->i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL);
+        /* dirsync only applies to directories */
+        if (!S_ISDIR(mode))
+                ei->i_flags &= ~EXT3_DIRSYNC_FL;
+#ifdef EXT3_FRAGMENTS
+        ei->i_faddr = 0;
+        ei->i_frag_no = 0;
+        ei->i_frag_size = 0;
+#endif
+        ei->i_file_acl = 0;
+        ei->i_dir_acl = 0;
+        ei->i_dtime = 0;
+        ei->i_block_alloc_info = NULL;
+        ei->i_block_group = group;
+
+        ext3_set_inode_flags(inode);
+        if (IS_DIRSYNC(inode))
+                handle->h_sync = 1;
+        insert_inode_hash(inode);
+        spin_lock(&sbi->s_next_gen_lock);
+        inode->i_generation = sbi->s_next_generation++;
+        spin_unlock(&sbi->s_next_gen_lock);
+
+        ei->i_state = EXT3_STATE_NEW;
+        ei->i_extra_isize =
+                (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) ?
+                sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE : 0;
+
+        ret = inode;
+        if(DQUOT_ALLOC_INODE(inode)) {
+                DQUOT_DROP(inode);
+                err = -EDQUOT;
+                goto fail2;
+        }
+        err = ext3_init_acl(handle, inode, dir);
+        if (err) {
+                DQUOT_FREE_INODE(inode);
+                goto fail2;
+        }
+        err = ext3_mark_inode_dirty(handle, inode);
+        if (err) {
+                ext3_std_error(sb, err);
+                DQUOT_FREE_INODE(inode);
+                goto fail2;
+        }
+
+        ext3_debug("allocating inode %lu\n", inode->i_ino);
+        goto really_out;
+fail:
+        ext3_std_error(sb, err);
+out:
+        iput(inode);
+        ret = ERR_PTR(err);
+really_out:
+        brelse(bitmap_bh);
+        return ret;
+
+fail2:
+        inode->i_flags |= S_NOQUOTA;
+        inode->i_nlink = 0;
+        iput(inode);
+        brelse(bitmap_bh);
+        return ERR_PTR(err);
+}
+
+/* Verify that we are loading a valid orphan from disk */
+struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino)
+{
+        unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
+        unsigned long block_group;
+        int bit;
+        struct buffer_head *bitmap_bh = NULL;
+        struct inode *inode = NULL;
+
+        /* Error cases - e2fsck has already cleaned up for us */
+        if (ino > max_ino) {
+                ext3_warning(sb, __FUNCTION__,
+                             "bad orphan ino %lu!  e2fsck was run?\n", ino);
+                goto out;
+        }
+
+        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
+        bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
+        bitmap_bh = read_inode_bitmap(sb, block_group);
+        if (!bitmap_bh) {
+                ext3_warning(sb, __FUNCTION__,
+                             "inode bitmap error for orphan %lu\n", ino);
+                goto out;
+        }
+
+        /* Having the inode bit set should be a 100% indicator that this
+         * is a valid orphan (no e2fsck run on fs).  Orphans also include
+         * inodes that were being truncated, so we can't check i_nlink==0.
+         */
+        if (!ext3_test_bit(bit, bitmap_bh->b_data) ||
+                        !(inode = iget(sb, ino)) || is_bad_inode(inode) ||
+                        NEXT_ORPHAN(inode) > max_ino) {
+                ext3_warning(sb, __FUNCTION__,
+                             "bad orphan inode %lu!  e2fsck was run?\n", ino);
+                printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n",
+                       bit, (unsigned long long)bitmap_bh->b_blocknr,
+                       ext3_test_bit(bit, bitmap_bh->b_data));
+                printk(KERN_NOTICE "inode=%p\n", inode);
+                if (inode) {
+                        printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
+                               is_bad_inode(inode));
+                        printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
+                               NEXT_ORPHAN(inode));
+                        printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
+                }
+                /* Avoid freeing blocks if we got a bad deleted inode */
+                if (inode && inode->i_nlink == 0)
+                        inode->i_blocks = 0;
+                iput(inode);
+                inode = NULL;
+        }
+out:
+        brelse(bitmap_bh);
+        return inode;
+}
+
+unsigned long ext3_count_free_inodes (struct super_block * sb)
+{
+        unsigned long desc_count;
+        struct ext3_group_desc *gdp;
+        int i;
+#ifdef EXT3FS_DEBUG
+        struct ext3_super_block *es;
+        unsigned long bitmap_count, x;
+        struct buffer_head *bitmap_bh = NULL;
+
+        lock_super (sb);
+        es = EXT3_SB(sb)->s_es;
+        desc_count = 0;
+        bitmap_count = 0;
+        gdp = NULL;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+                brelse(bitmap_bh);
+                bitmap_bh = read_inode_bitmap(sb, i);
+                if (!bitmap_bh)
+                        continue;
+
+                x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
+                printk("group %d: stored = %d, counted = %lu\n",
+                        i, le16_to_cpu(gdp->bg_free_inodes_count), x);
+                bitmap_count += x;
+        }
+        brelse(bitmap_bh);
+        printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
+                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
+        unlock_super(sb);
+        return desc_count;
+#else
+        desc_count = 0;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+                cond_resched();
+        }
+        return desc_count;
+#endif
+}
+
+/* Called at mount-time, super-block is locked */
+unsigned long ext3_count_dirs (struct super_block * sb)
+{
+        unsigned long count = 0;
+        int i;
+
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                count += le16_to_cpu(gdp->bg_used_dirs_count);
+        }
+        return count;
+}
+
+#ifdef CONFIG_EXT3_CHECK
+/* Called at mount-time, super-block is locked */
+void ext3_check_inodes_bitmap (struct super_block * sb)
+{
+        struct ext3_super_block * es;
+        unsigned long desc_count, bitmap_count, x;
+        struct buffer_head *bitmap_bh = NULL;
+        struct ext3_group_desc * gdp;
+        int i;
+
+        es = EXT3_SB(sb)->s_es;
+        desc_count = 0;
+        bitmap_count = 0;
+        gdp = NULL;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+                brelse(bitmap_bh);
+                bitmap_bh = read_inode_bitmap(sb, i);
+                if (!bitmap_bh)
+                        continue;
+
+                x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
+                if (le16_to_cpu(gdp->bg_free_inodes_count) != x)
+                        ext3_error (sb, "ext3_check_inodes_bitmap",
+                                    "Wrong free inodes count in group %d, "
+                                    "stored = %d, counted = %lu", i,
+                                    le16_to_cpu(gdp->bg_free_inodes_count), x);
+                bitmap_count += x;
+        }
+        brelse(bitmap_bh);
+        if (le32_to_cpu(es->s_free_inodes_count) != bitmap_count)
+                ext3_error (sb, "ext3_check_inodes_bitmap",
+                            "Wrong free inodes count in super block, "
+                            "stored = %lu, counted = %lu",
+                            (unsigned long)le32_to_cpu(es->s_free_inodes_count),
+                            bitmap_count);
+}
+#endif
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
new file mode 100644
index 000000000000..040eb288bb1c
--- /dev/null
+++ b/fs/ext3/inode.c
@@ -0,0 +1,3132 @@
+/*
+ *  linux/fs/ext3/inode.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/inode.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Goal-directed block allocation by Stephen Tweedie
+ *      (sct@redhat.com), 1993, 1998
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *  64-bit file support on 64-bit platforms by Jakub Jelinek
+ *      (jj@sunsite.ms.mff.cuni.cz)
+ *
+ *  Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/ext3_jbd.h>
+#include <linux/jbd.h>
+#include <linux/smp_lock.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include <linux/string.h>
+#include <linux/buffer_head.h>
+#include <linux/writeback.h>
+#include <linux/mpage.h>
+#include <linux/uio.h>
+#include "xattr.h"
+#include "acl.h"
+
+static int ext3_writepage_trans_blocks(struct inode *inode);
+
+/*
+ * Test whether an inode is a fast symlink.
+ */
+static inline int ext3_inode_is_fast_symlink(struct inode *inode)
+{
+        int ea_blocks = EXT3_I(inode)->i_file_acl ?
+                (inode->i_sb->s_blocksize >> 9) : 0;
+
+        return (S_ISLNK(inode->i_mode) &&
+                inode->i_blocks - ea_blocks == 0);
+}
+
+/* The ext3 forget function must perform a revoke if we are freeing data
+ * which has been journaled.  Metadata (eg. indirect blocks) must be
+ * revoked in all cases. 
+ *
+ * "bh" may be NULL: a metadata block may have been freed from memory
+ * but there may still be a record of it in the journal, and that record
+ * still needs to be revoked.
+ */
+
+int ext3_forget(handle_t *handle, int is_metadata,
+                       struct inode *inode, struct buffer_head *bh,
+                       int blocknr)
+{
+        int err;
+
+        might_sleep();
+
+        BUFFER_TRACE(bh, "enter");
+
+        jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
+                  "data mode %lx\n",
+                  bh, is_metadata, inode->i_mode,
+                  test_opt(inode->i_sb, DATA_FLAGS));
+
+        /* Never use the revoke function if we are doing full data
+         * journaling: there is no need to, and a V1 superblock won't
+         * support it.  Otherwise, only skip the revoke on un-journaled
+         * data blocks. */
+
+        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
+            (!is_metadata && !ext3_should_journal_data(inode))) {
+                if (bh) {
+                        BUFFER_TRACE(bh, "call journal_forget");
+                        return ext3_journal_forget(handle, bh);
+                }
+                return 0;
+        }
+
+        /*
+         * data!=journal && (is_metadata || should_journal_data(inode))
+         */
+        BUFFER_TRACE(bh, "call ext3_journal_revoke");
+        err = ext3_journal_revoke(handle, blocknr, bh);
+        if (err)
+                ext3_abort(inode->i_sb, __FUNCTION__,
+                           "error %d when attempting revoke", err);
+        BUFFER_TRACE(bh, "exit");
+        return err;
+}
+
+/*
+ * Work out how many blocks we need to progress with the next chunk of a
+ * truncate transaction.
+ */
+
+static unsigned long blocks_for_truncate(struct inode *inode) 
+{
+        unsigned long needed;
+
+        needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
+
+        /* Give ourselves just enough room to cope with inodes in which
+         * i_blocks is corrupt: we've seen disk corruptions in the past
+         * which resulted in random data in an inode which looked enough
+         * like a regular file for ext3 to try to delete it.  Things
+         * will go a bit crazy if that happens, but at least we should
+         * try not to panic the whole kernel. */
+        if (needed < 2)
+                needed = 2;
+
+        /* But we need to bound the transaction so we don't overflow the
+         * journal. */
+        if (needed > EXT3_MAX_TRANS_DATA) 
+                needed = EXT3_MAX_TRANS_DATA;
+
+        return EXT3_DATA_TRANS_BLOCKS + needed;
+}
+
+/* 
+ * Truncate transactions can be complex and absolutely huge.  So we need to
+ * be able to restart the transaction at a conventient checkpoint to make
+ * sure we don't overflow the journal.
+ *
+ * start_transaction gets us a new handle for a truncate transaction,
+ * and extend_transaction tries to extend the existing one a bit.  If
+ * extend fails, we need to propagate the failure up and restart the
+ * transaction in the top-level truncate loop. --sct 
+ */
+
+static handle_t *start_transaction(struct inode *inode) 
+{
+        handle_t *result;
+
+        result = ext3_journal_start(inode, blocks_for_truncate(inode));
+        if (!IS_ERR(result))
+                return result;
+
+        ext3_std_error(inode->i_sb, PTR_ERR(result));
+        return result;
+}
+
+/*
+ * Try to extend this transaction for the purposes of truncation.
+ *
+ * Returns 0 if we managed to create more room.  If we can't create more
+ * room, and the transaction must be restarted we return 1.
+ */
+static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
+{
+        if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
+                return 0;
+        if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
+                return 0;
+        return 1;
+}
+
+/*
+ * Restart the transaction associated with *handle.  This does a commit,
+ * so before we call here everything must be consistently dirtied against
+ * this transaction.
+ */
+static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
+{
+        jbd_debug(2, "restarting handle %p\n", handle);
+        return ext3_journal_restart(handle, blocks_for_truncate(inode));
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void ext3_delete_inode (struct inode * inode)
+{
+        handle_t *handle;
+
+        if (is_bad_inode(inode))
+                goto no_delete;
+
+        handle = start_transaction(inode);
+        if (IS_ERR(handle)) {
+                /* If we're going to skip the normal cleanup, we still
+                 * need to make sure that the in-core orphan linked list
+                 * is properly cleaned up. */
+                ext3_orphan_del(NULL, inode);
+                goto no_delete;
+        }
+
+        if (IS_SYNC(inode))
+                handle->h_sync = 1;
+        inode->i_size = 0;
+        if (inode->i_blocks)
+                ext3_truncate(inode);
+        /*
+         * Kill off the orphan record which ext3_truncate created.
+         * AKPM: I think this can be inside the above `if'.
+         * Note that ext3_orphan_del() has to be able to cope with the
+         * deletion of a non-existent orphan - this is because we don't
+         * know if ext3_truncate() actually created an orphan record.
+         * (Well, we could do this if we need to, but heck - it works)
+         */
+        ext3_orphan_del(handle, inode);
+        EXT3_I(inode)->i_dtime  = get_seconds();
+
+        /* 
+         * One subtle ordering requirement: if anything has gone wrong
+         * (transaction abort, IO errors, whatever), then we can still
+         * do these next steps (the fs will already have been marked as
+         * having errors), but we can't free the inode if the mark_dirty
+         * fails.  
+         */
+        if (ext3_mark_inode_dirty(handle, inode))
+                /* If that failed, just do the required in-core inode clear. */
+                clear_inode(inode);
+        else
+                ext3_free_inode(handle, inode);
+        ext3_journal_stop(handle);
+        return;
+no_delete:
+        clear_inode(inode);     /* We must guarantee clearing of inode... */
+}
+
+static int ext3_alloc_block (handle_t *handle,
+                        struct inode * inode, unsigned long goal, int *err)
+{
+        unsigned long result;
+
+        result = ext3_new_block(handle, inode, goal, err);
+        return result;
+}
+
+
+typedef struct {
+        __le32  *p;
+        __le32  key;
+        struct buffer_head *bh;
+} Indirect;
+
+static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
+{
+        p->key = *(p->p = v);
+        p->bh = bh;
+}
+
+static inline int verify_chain(Indirect *from, Indirect *to)
+{
+        while (from <= to && from->key == *from->p)
+                from++;
+        return (from > to);
+}
+
+/**
+ *      ext3_block_to_path - parse the block number into array of offsets
+ *      @inode: inode in question (we are only interested in its superblock)
+ *      @i_block: block number to be parsed
+ *      @offsets: array to store the offsets in
+ *      @boundary: set this non-zero if the referred-to block is likely to be
+ *             followed (on disk) by an indirect block.
+ *
+ *      To store the locations of file's data ext3 uses a data structure common
+ *      for UNIX filesystems - tree of pointers anchored in the inode, with
+ *      data blocks at leaves and indirect blocks in intermediate nodes.
+ *      This function translates the block number into path in that tree -
+ *      return value is the path length and @offsets[n] is the offset of
+ *      pointer to (n+1)th node in the nth one. If @block is out of range
+ *      (negative or too large) warning is printed and zero returned.
+ *
+ *      Note: function doesn't find node addresses, so no IO is needed. All
+ *      we need to know is the capacity of indirect blocks (taken from the
+ *      inode->i_sb).
+ */
+
+/*
+ * Portability note: the last comparison (check that we fit into triple
+ * indirect block) is spelled differently, because otherwise on an
+ * architecture with 32-bit longs and 8Kb pages we might get into trouble
+ * if our filesystem had 8Kb blocks. We might use long long, but that would
+ * kill us on x86. Oh, well, at least the sign propagation does not matter -
+ * i_block would have to be negative in the very beginning, so we would not
+ * get there at all.
+ */
+
+static int ext3_block_to_path(struct inode *inode,
+                        long i_block, int offsets[4], int *boundary)
+{
+        int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
+        int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
+        const long direct_blocks = EXT3_NDIR_BLOCKS,
+                indirect_blocks = ptrs,
+                double_blocks = (1 << (ptrs_bits * 2));
+        int n = 0;
+        int final = 0;
+
+        if (i_block < 0) {
+                ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
+        } else if (i_block < direct_blocks) {
+                offsets[n++] = i_block;
+                final = direct_blocks;
+        } else if ( (i_block -= direct_blocks) < indirect_blocks) {
+                offsets[n++] = EXT3_IND_BLOCK;
+                offsets[n++] = i_block;
+                final = ptrs;
+        } else if ((i_block -= indirect_blocks) < double_blocks) {
+                offsets[n++] = EXT3_DIND_BLOCK;
+                offsets[n++] = i_block >> ptrs_bits;
+                offsets[n++] = i_block & (ptrs - 1);
+                final = ptrs;
+        } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
+                offsets[n++] = EXT3_TIND_BLOCK;
+                offsets[n++] = i_block >> (ptrs_bits * 2);
+                offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
+                offsets[n++] = i_block & (ptrs - 1);
+                final = ptrs;
+        } else {
+                ext3_warning (inode->i_sb, "ext3_block_to_path", "block > big");
+        }
+        if (boundary)
+                *boundary = (i_block & (ptrs - 1)) == (final - 1);
+        return n;
+}
+
+/**
+ *      ext3_get_branch - read the chain of indirect blocks leading to data
+ *      @inode: inode in question
+ *      @depth: depth of the chain (1 - direct pointer, etc.)
+ *      @offsets: offsets of pointers in inode/indirect blocks
+ *      @chain: place to store the result
+ *      @err: here we store the error value
+ *
+ *      Function fills the array of triples <key, p, bh> and returns %NULL
+ *      if everything went OK or the pointer to the last filled triple
+ *      (incomplete one) otherwise. Upon the return chain[i].key contains
+ *      the number of (i+1)-th block in the chain (as it is stored in memory,
+ *      i.e. little-endian 32-bit), chain[i].p contains the address of that
+ *      number (it points into struct inode for i==0 and into the bh->b_data
+ *      for i>0) and chain[i].bh points to the buffer_head of i-th indirect
+ *      block for i>0 and NULL for i==0. In other words, it holds the block
+ *      numbers of the chain, addresses they were taken from (and where we can
+ *      verify that chain did not change) and buffer_heads hosting these
+ *      numbers.
+ *
+ *      Function stops when it stumbles upon zero pointer (absent block)
+ *              (pointer to last triple returned, *@err == 0)
+ *      or when it gets an IO error reading an indirect block
+ *              (ditto, *@err == -EIO)
+ *      or when it notices that chain had been changed while it was reading
+ *              (ditto, *@err == -EAGAIN)
+ *      or when it reads all @depth-1 indirect blocks successfully and finds
+ *      the whole chain, all way to the data (returns %NULL, *err == 0).
+ */
+static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
+                                 Indirect chain[4], int *err)
+{
+        struct super_block *sb = inode->i_sb;
+        Indirect *p = chain;
+        struct buffer_head *bh;
+
+        *err = 0;
+        /* i_data is not going away, no lock needed */
+        add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
+        if (!p->key)
+                goto no_block;
+        while (--depth) {
+                bh = sb_bread(sb, le32_to_cpu(p->key));
+                if (!bh)
+                        goto failure;
+                /* Reader: pointers */
+                if (!verify_chain(chain, p))
+                        goto changed;
+                add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
+                /* Reader: end */
+                if (!p->key)
+                        goto no_block;
+        }
+        return NULL;
+
+changed:
+        brelse(bh);
+        *err = -EAGAIN;
+        goto no_block;
+failure:
+        *err = -EIO;
+no_block:
+        return p;
+}
+
+/**
+ *      ext3_find_near - find a place for allocation with sufficient locality
+ *      @inode: owner
+ *      @ind: descriptor of indirect block.
+ *
+ *      This function returns the prefered place for block allocation.
+ *      It is used when heuristic for sequential allocation fails.
+ *      Rules are:
+ *        + if there is a block to the left of our position - allocate near it.
+ *        + if pointer will live in indirect block - allocate near that block.
+ *        + if pointer will live in inode - allocate in the same
+ *          cylinder group. 
+ *
+ * In the latter case we colour the starting block by the callers PID to
+ * prevent it from clashing with concurrent allocations for a different inode
+ * in the same block group.   The PID is used here so that functionally related
+ * files will be close-by on-disk.
+ *
+ *      Caller must make sure that @ind is valid and will stay that way.
+ */
+
+static unsigned long ext3_find_near(struct inode *inode, Indirect *ind)
+{
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
+        __le32 *p;
+        unsigned long bg_start;
+        unsigned long colour;
+
+        /* Try to find previous block */
+        for (p = ind->p - 1; p >= start; p--)
+                if (*p)
+                        return le32_to_cpu(*p);
+
+        /* No such thing, so let's try location of indirect block */
+        if (ind->bh)
+                return ind->bh->b_blocknr;
+
+        /*
+         * It is going to be refered from inode itself? OK, just put it into
+         * the same cylinder group then.
+         */
+        bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
+                le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
+        colour = (current->pid % 16) *
+                        (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+        return bg_start + colour;
+}
+
+/**
+ *      ext3_find_goal - find a prefered place for allocation.
+ *      @inode: owner
+ *      @block:  block we want
+ *      @chain:  chain of indirect blocks
+ *      @partial: pointer to the last triple within a chain
+ *      @goal:  place to store the result.
+ *
+ *      Normally this function find the prefered place for block allocation,
+ *      stores it in *@goal and returns zero. If the branch had been changed
+ *      under us we return -EAGAIN.
+ */
+
+static int ext3_find_goal(struct inode *inode, long block, Indirect chain[4],
+                          Indirect *partial, unsigned long *goal)
+{
+        struct ext3_block_alloc_info *block_i =  EXT3_I(inode)->i_block_alloc_info;
+
+        /*
+         * try the heuristic for sequential allocation,
+         * failing that at least try to get decent locality.
+         */
+        if (block_i && (block == block_i->last_alloc_logical_block + 1)
+                && (block_i->last_alloc_physical_block != 0)) {
+                *goal = block_i->last_alloc_physical_block + 1;
+                return 0;
+        }
+
+        if (verify_chain(chain, partial)) {
+                *goal = ext3_find_near(inode, partial);
+                return 0;
+        }
+        return -EAGAIN;
+}
+
+/**
+ *      ext3_alloc_branch - allocate and set up a chain of blocks.
+ *      @inode: owner
+ *      @num: depth of the chain (number of blocks to allocate)
+ *      @offsets: offsets (in the blocks) to store the pointers to next.
+ *      @branch: place to store the chain in.
+ *
+ *      This function allocates @num blocks, zeroes out all but the last one,
+ *      links them into chain and (if we are synchronous) writes them to disk.
+ *      In other words, it prepares a branch that can be spliced onto the
+ *      inode. It stores the information about that chain in the branch[], in
+ *      the same format as ext3_get_branch() would do. We are calling it after
+ *      we had read the existing part of chain and partial points to the last
+ *      triple of that (one with zero ->key). Upon the exit we have the same
+ *      picture as after the successful ext3_get_block(), excpet that in one
+ *      place chain is disconnected - *branch->p is still zero (we did not
+ *      set the last link), but branch->key contains the number that should
+ *      be placed into *branch->p to fill that gap.
+ *
+ *      If allocation fails we free all blocks we've allocated (and forget
+ *      their buffer_heads) and return the error value the from failed
+ *      ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
+ *      as described above and return 0.
+ */
+
+static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
+                             int num,
+                             unsigned long goal,
+                             int *offsets,
+                             Indirect *branch)
+{
+        int blocksize = inode->i_sb->s_blocksize;
+        int n = 0, keys = 0;
+        int err = 0;
+        int i;
+        int parent = ext3_alloc_block(handle, inode, goal, &err);
+
+        branch[0].key = cpu_to_le32(parent);
+        if (parent) {
+                for (n = 1; n < num; n++) {
+                        struct buffer_head *bh;
+                        /* Allocate the next block */
+                        int nr = ext3_alloc_block(handle, inode, parent, &err);
+                        if (!nr)
+                                break;
+                        branch[n].key = cpu_to_le32(nr);
+                        keys = n+1;
+
+                        /*
+                         * Get buffer_head for parent block, zero it out
+                         * and set the pointer to new one, then send
+                         * parent to disk.  
+                         */
+                        bh = sb_getblk(inode->i_sb, parent);
+                        branch[n].bh = bh;
+                        lock_buffer(bh);
+                        BUFFER_TRACE(bh, "call get_create_access");
+                        err = ext3_journal_get_create_access(handle, bh);
+                        if (err) {
+                                unlock_buffer(bh);
+                                brelse(bh);
+                                break;
+                        }
+
+                        memset(bh->b_data, 0, blocksize);
+                        branch[n].p = (__le32*) bh->b_data + offsets[n];
+                        *branch[n].p = branch[n].key;
+                        BUFFER_TRACE(bh, "marking uptodate");
+                        set_buffer_uptodate(bh);
+                        unlock_buffer(bh);
+
+                        BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+                        err = ext3_journal_dirty_metadata(handle, bh);
+                        if (err)
+                                break;
+
+                        parent = nr;
+                }
+        }
+        if (n == num)
+                return 0;
+
+        /* Allocation failed, free what we already allocated */
+        for (i = 1; i < keys; i++) {
+                BUFFER_TRACE(branch[i].bh, "call journal_forget");
+                ext3_journal_forget(handle, branch[i].bh);
+        }
+        for (i = 0; i < keys; i++)
+                ext3_free_blocks(handle, inode, le32_to_cpu(branch[i].key), 1);
+        return err;
+}
+
+/**
+ *      ext3_splice_branch - splice the allocated branch onto inode.
+ *      @inode: owner
+ *      @block: (logical) number of block we are adding
+ *      @chain: chain of indirect blocks (with a missing link - see
+ *              ext3_alloc_branch)
+ *      @where: location of missing link
+ *      @num:   number of blocks we are adding
+ *
+ *      This function verifies that chain (up to the missing link) had not
+ *      changed, fills the missing link and does all housekeeping needed in
+ *      inode (->i_blocks, etc.). In case of success we end up with the full
+ *      chain to new block and return 0. Otherwise (== chain had been changed)
+ *      we free the new blocks (forgetting their buffer_heads, indeed) and
+ *      return -EAGAIN.
+ */
+
+static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block,
+                              Indirect chain[4], Indirect *where, int num)
+{
+        int i;
+        int err = 0;
+        struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info;
+
+        /*
+         * If we're splicing into a [td]indirect block (as opposed to the
+         * inode) then we need to get write access to the [td]indirect block
+         * before the splice.
+         */
+        if (where->bh) {
+                BUFFER_TRACE(where->bh, "get_write_access");
+                err = ext3_journal_get_write_access(handle, where->bh);
+                if (err)
+                        goto err_out;
+        }
+        /* Verify that place we are splicing to is still there and vacant */
+
+        if (!verify_chain(chain, where-1) || *where->p)
+                /* Writer: end */
+                goto changed;
+
+        /* That's it */
+
+        *where->p = where->key;
+
+        /*
+         * update the most recently allocated logical & physical block
+         * in i_block_alloc_info, to assist find the proper goal block for next
+         * allocation
+         */
+        if (block_i) {
+                block_i->last_alloc_logical_block = block;
+                block_i->last_alloc_physical_block = le32_to_cpu(where[num-1].key);
+        }
+
+        /* We are done with atomic stuff, now do the rest of housekeeping */
+
+        inode->i_ctime = CURRENT_TIME_SEC;
+        ext3_mark_inode_dirty(handle, inode);
+
+        /* had we spliced it onto indirect block? */
+        if (where->bh) {
+                /*
+                 * akpm: If we spliced it onto an indirect block, we haven't
+                 * altered the inode.  Note however that if it is being spliced
+                 * onto an indirect block at the very end of the file (the
+                 * file is growing) then we *will* alter the inode to reflect
+                 * the new i_size.  But that is not done here - it is done in
+                 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
+                 */
+                jbd_debug(5, "splicing indirect only\n");
+                BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
+                err = ext3_journal_dirty_metadata(handle, where->bh);
+                if (err) 
+                        goto err_out;
+        } else {
+                /*
+                 * OK, we spliced it into the inode itself on a direct block.
+                 * Inode was dirtied above.
+                 */
+                jbd_debug(5, "splicing direct\n");
+        }
+        return err;
+
+changed:
+        /*
+         * AKPM: if where[i].bh isn't part of the current updating
+         * transaction then we explode nastily.  Test this code path.
+         */
+        jbd_debug(1, "the chain changed: try again\n");
+        err = -EAGAIN;
+
+err_out:
+        for (i = 1; i < num; i++) {
+                BUFFER_TRACE(where[i].bh, "call journal_forget");
+                ext3_journal_forget(handle, where[i].bh);
+        }
+        /* For the normal collision cleanup case, we free up the blocks.
+         * On genuine filesystem errors we don't even think about doing
+         * that. */
+        if (err == -EAGAIN)
+                for (i = 0; i < num; i++)
+                        ext3_free_blocks(handle, inode, 
+                                         le32_to_cpu(where[i].key), 1);
+        return err;
+}
+
+/*
+ * Allocation strategy is simple: if we have to allocate something, we will
+ * have to go the whole way to leaf. So let's do it before attaching anything
+ * to tree, set linkage between the newborn blocks, write them if sync is
+ * required, recheck the path, free and repeat if check fails, otherwise
+ * set the last missing link (that will protect us from any truncate-generated
+ * removals - all blocks on the path are immune now) and possibly force the
+ * write on the parent block.
+ * That has a nice additional property: no special recovery from the failed
+ * allocations is needed - we simply release blocks and do not touch anything
+ * reachable from inode.
+ *
+ * akpm: `handle' can be NULL if create == 0.
+ *
+ * The BKL may not be held on entry here.  Be sure to take it early.
+ */
+
+static int
+ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
+                struct buffer_head *bh_result, int create, int extend_disksize)
+{
+        int err = -EIO;
+        int offsets[4];
+        Indirect chain[4];
+        Indirect *partial;
+        unsigned long goal;
+        int left;
+        int boundary = 0;
+        int depth = ext3_block_to_path(inode, iblock, offsets, &boundary);
+        struct ext3_inode_info *ei = EXT3_I(inode);
+
+        J_ASSERT(handle != NULL || create == 0);
+
+        if (depth == 0)
+                goto out;
+
+reread:
+        partial = ext3_get_branch(inode, depth, offsets, chain, &err);
+
+        /* Simplest case - block found, no allocation needed */
+        if (!partial) {
+                clear_buffer_new(bh_result);
+got_it:
+                map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
+                if (boundary)
+                        set_buffer_boundary(bh_result);
+                /* Clean up and exit */
+                partial = chain+depth-1; /* the whole chain */
+                goto cleanup;
+        }
+
+        /* Next simple case - plain lookup or failed read of indirect block */
+        if (!create || err == -EIO) {
+cleanup:
+                while (partial > chain) {
+                        BUFFER_TRACE(partial->bh, "call brelse");
+                        brelse(partial->bh);
+                        partial--;
+                }
+                BUFFER_TRACE(bh_result, "returned");
+out:
+                return err;
+        }
+
+        /*
+         * Indirect block might be removed by truncate while we were
+         * reading it. Handling of that case (forget what we've got and
+         * reread) is taken out of the main path.
+         */
+        if (err == -EAGAIN)
+                goto changed;
+
+        goal = 0;
+        down(&ei->truncate_sem);
+
+        /* lazy initialize the block allocation info here if necessary */
+        if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) {
+                ext3_init_block_alloc_info(inode);
+        }
+
+        if (ext3_find_goal(inode, iblock, chain, partial, &goal) < 0) {
+                up(&ei->truncate_sem);
+                goto changed;
+        }
+
+        left = (chain + depth) - partial;
+
+        /*
+         * Block out ext3_truncate while we alter the tree
+         */
+        err = ext3_alloc_branch(handle, inode, left, goal,
+                                        offsets+(partial-chain), partial);
+
+        /* The ext3_splice_branch call will free and forget any buffers
+         * on the new chain if there is a failure, but that risks using
+         * up transaction credits, especially for bitmaps where the
+         * credits cannot be returned.  Can we handle this somehow?  We
+         * may need to return -EAGAIN upwards in the worst case.  --sct */
+        if (!err)
+                err = ext3_splice_branch(handle, inode, iblock, chain,
+                                         partial, left);
+        /* i_disksize growing is protected by truncate_sem
+         * don't forget to protect it if you're about to implement
+         * concurrent ext3_get_block() -bzzz */
+        if (!err && extend_disksize && inode->i_size > ei->i_disksize)
+                ei->i_disksize = inode->i_size;
+        up(&ei->truncate_sem);
+        if (err == -EAGAIN)
+                goto changed;
+        if (err)
+                goto cleanup;
+
+        set_buffer_new(bh_result);
+        goto got_it;
+
+changed:
+        while (partial > chain) {
+                jbd_debug(1, "buffer chain changed, retrying\n");
+                BUFFER_TRACE(partial->bh, "brelsing");
+                brelse(partial->bh);
+                partial--;
+        }
+        goto reread;
+}
+
+static int ext3_get_block(struct inode *inode, sector_t iblock,
+                        struct buffer_head *bh_result, int create)
+{
+        handle_t *handle = NULL;
+        int ret;
+
+        if (create) {
+                handle = ext3_journal_current_handle();
+                J_ASSERT(handle != 0);
+        }
+        ret = ext3_get_block_handle(handle, inode, iblock,
+                                bh_result, create, 1);
+        return ret;
+}
+
+#define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
+
+static int
+ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock,
+                unsigned long max_blocks, struct buffer_head *bh_result,
+                int create)
+{
+        handle_t *handle = journal_current_handle();
+        int ret = 0;
+
+        if (!handle)
+                goto get_block;         /* A read */
+
+        if (handle->h_transaction->t_state == T_LOCKED) {
+                /*
+                 * Huge direct-io writes can hold off commits for long
+                 * periods of time.  Let this commit run.
+                 */
+                ext3_journal_stop(handle);
+                handle = ext3_journal_start(inode, DIO_CREDITS);
+                if (IS_ERR(handle))
+                        ret = PTR_ERR(handle);
+                goto get_block;
+        }
+
+        if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
+                /*
+                 * Getting low on buffer credits...
+                 */
+                ret = ext3_journal_extend(handle, DIO_CREDITS);
+                if (ret > 0) {
+                        /*
+                         * Couldn't extend the transaction.  Start a new one.
+                         */
+                        ret = ext3_journal_restart(handle, DIO_CREDITS);
+                }
+        }
+
+get_block:
+        if (ret == 0)
+                ret = ext3_get_block_handle(handle, inode, iblock,
+                                        bh_result, create, 0);
+        bh_result->b_size = (1 << inode->i_blkbits);
+        return ret;
+}
+
+static int ext3_writepages_get_block(struct inode *inode, sector_t iblock,
+                        struct buffer_head *bh, int create)
+{
+        return ext3_direct_io_get_blocks(inode, iblock, 1, bh, create);
+}
+
+/*
+ * `handle' can be NULL if create is zero
+ */
+struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode,
+                                long block, int create, int * errp)
+{
+        struct buffer_head dummy;
+        int fatal = 0, err;
+
+        J_ASSERT(handle != NULL || create == 0);
+
+        dummy.b_state = 0;
+        dummy.b_blocknr = -1000;
+        buffer_trace_init(&dummy.b_history);
+        *errp = ext3_get_block_handle(handle, inode, block, &dummy, create, 1);
+        if (!*errp && buffer_mapped(&dummy)) {
+                struct buffer_head *bh;
+                bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
+                if (buffer_new(&dummy)) {
+                        J_ASSERT(create != 0);
+                        J_ASSERT(handle != 0);
+
+                        /* Now that we do not always journal data, we
+                           should keep in mind whether this should
+                           always journal the new buffer as metadata.
+                           For now, regular file writes use
+                           ext3_get_block instead, so it's not a
+                           problem. */
+                        lock_buffer(bh);
+                        BUFFER_TRACE(bh, "call get_create_access");
+                        fatal = ext3_journal_get_create_access(handle, bh);
+                        if (!fatal && !buffer_uptodate(bh)) {
+                                memset(bh->b_data, 0, inode->i_sb->s_blocksize);
+                                set_buffer_uptodate(bh);
+                        }
+                        unlock_buffer(bh);
+                        BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+                        err = ext3_journal_dirty_metadata(handle, bh);
+                        if (!fatal)
+                                fatal = err;
+                } else {
+                        BUFFER_TRACE(bh, "not a new buffer");
+                }
+                if (fatal) {
+                        *errp = fatal;
+                        brelse(bh);
+                        bh = NULL;
+                }
+                return bh;
+        }
+        return NULL;
+}
+
+struct buffer_head *ext3_bread(handle_t *handle, struct inode * inode,
+                               int block, int create, int *err)
+{
+        struct buffer_head * bh;
+
+        bh = ext3_getblk(handle, inode, block, create, err);
+        if (!bh)
+                return bh;
+        if (buffer_uptodate(bh))
+                return bh;
+        ll_rw_block(READ, 1, &bh);
+        wait_on_buffer(bh);
+        if (buffer_uptodate(bh))
+                return bh;
+        put_bh(bh);
+        *err = -EIO;
+        return NULL;
+}
+
+static int walk_page_buffers(   handle_t *handle,
+                                struct buffer_head *head,
+                                unsigned from,
+                                unsigned to,
+                                int *partial,
+                                int (*fn)(      handle_t *handle,
+                                                struct buffer_head *bh))
+{
+        struct buffer_head *bh;
+        unsigned block_start, block_end;
+        unsigned blocksize = head->b_size;
+        int err, ret = 0;
+        struct buffer_head *next;
+
+        for (   bh = head, block_start = 0;
+                ret == 0 && (bh != head || !block_start);
+                block_start = block_end, bh = next)
+        {
+                next = bh->b_this_page;
+                block_end = block_start + blocksize;
+                if (block_end <= from || block_start >= to) {
+                        if (partial && !buffer_uptodate(bh))
+                                *partial = 1;
+                        continue;
+                }
+                err = (*fn)(handle, bh);
+                if (!ret)
+                        ret = err;
+        }
+        return ret;
+}
+
+/*
+ * To preserve ordering, it is essential that the hole instantiation and
+ * the data write be encapsulated in a single transaction.  We cannot
+ * close off a transaction and start a new one between the ext3_get_block()
+ * and the commit_write().  So doing the journal_start at the start of
+ * prepare_write() is the right place.
+ *
+ * Also, this function can nest inside ext3_writepage() ->
+ * block_write_full_page(). In that case, we *know* that ext3_writepage()
+ * has generated enough buffer credits to do the whole page.  So we won't
+ * block on the journal in that case, which is good, because the caller may
+ * be PF_MEMALLOC.
+ *
+ * By accident, ext3 can be reentered when a transaction is open via
+ * quota file writes.  If we were to commit the transaction while thus
+ * reentered, there can be a deadlock - we would be holding a quota
+ * lock, and the commit would never complete if another thread had a
+ * transaction open and was blocking on the quota lock - a ranking
+ * violation.
+ *
+ * So what we do is to rely on the fact that journal_stop/journal_start
+ * will _not_ run commit under these circumstances because handle->h_ref
+ * is elevated.  We'll still have enough credits for the tiny quotafile
+ * write.  
+ */
+
+static int do_journal_get_write_access(handle_t *handle, 
+                                       struct buffer_head *bh)
+{
+        if (!buffer_mapped(bh) || buffer_freed(bh))
+                return 0;
+        return ext3_journal_get_write_access(handle, bh);
+}
+
+static int ext3_prepare_write(struct file *file, struct page *page,
+                              unsigned from, unsigned to)
+{
+        struct inode *inode = page->mapping->host;
+        int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
+        handle_t *handle;
+        int retries = 0;
+
+retry:
+        handle = ext3_journal_start(inode, needed_blocks);
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                goto out;
+        }
+        if (test_opt(inode->i_sb, NOBH))
+                ret = nobh_prepare_write(page, from, to, ext3_get_block);
+        else
+                ret = block_prepare_write(page, from, to, ext3_get_block);
+        if (ret)
+                goto prepare_write_failed;
+
+        if (ext3_should_journal_data(inode)) {
+                ret = walk_page_buffers(handle, page_buffers(page),
+                                from, to, NULL, do_journal_get_write_access);
+        }
+prepare_write_failed:
+        if (ret)
+                ext3_journal_stop(handle);
+        if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
+                goto retry;
+out:
+        return ret;
+}
+
+int
+ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
+{
+        int err = journal_dirty_data(handle, bh);
+        if (err)
+                ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
+                                                bh, handle,err);
+        return err;
+}
+
+/* For commit_write() in data=journal mode */
+static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
+{
+        if (!buffer_mapped(bh) || buffer_freed(bh))
+                return 0;
+        set_buffer_uptodate(bh);
+        return ext3_journal_dirty_metadata(handle, bh);
+}
+
+/*
+ * We need to pick up the new inode size which generic_commit_write gave us
+ * `file' can be NULL - eg, when called from page_symlink().
+ *
+ * ext3 never places buffers on inode->i_mapping->private_list.  metadata
+ * buffers are managed internally.
+ */
+
+static int ext3_ordered_commit_write(struct file *file, struct page *page,
+                             unsigned from, unsigned to)
+{
+        handle_t *handle = ext3_journal_current_handle();
+        struct inode *inode = page->mapping->host;
+        int ret = 0, ret2;
+
+        ret = walk_page_buffers(handle, page_buffers(page),
+                from, to, NULL, ext3_journal_dirty_data);
+
+        if (ret == 0) {
+                /*
+                 * generic_commit_write() will run mark_inode_dirty() if i_size
+                 * changes.  So let's piggyback the i_disksize mark_inode_dirty
+                 * into that.
+                 */
+                loff_t new_i_size;
+
+                new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+                if (new_i_size > EXT3_I(inode)->i_disksize)
+                        EXT3_I(inode)->i_disksize = new_i_size;
+                ret = generic_commit_write(file, page, from, to);
+        }
+        ret2 = ext3_journal_stop(handle);
+        if (!ret)
+                ret = ret2;
+        return ret;
+}
+
+static int ext3_writeback_commit_write(struct file *file, struct page *page,
+                             unsigned from, unsigned to)
+{
+        handle_t *handle = ext3_journal_current_handle();
+        struct inode *inode = page->mapping->host;
+        int ret = 0, ret2;
+        loff_t new_i_size;
+
+        new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+        if (new_i_size > EXT3_I(inode)->i_disksize)
+                EXT3_I(inode)->i_disksize = new_i_size;
+
+        if (test_opt(inode->i_sb, NOBH))
+                ret = nobh_commit_write(file, page, from, to);
+        else
+                ret = generic_commit_write(file, page, from, to);
+
+        ret2 = ext3_journal_stop(handle);
+        if (!ret)
+                ret = ret2;
+        return ret;
+}
+
+static int ext3_journalled_commit_write(struct file *file,
+                        struct page *page, unsigned from, unsigned to)
+{
+        handle_t *handle = ext3_journal_current_handle();
+        struct inode *inode = page->mapping->host;
+        int ret = 0, ret2;
+        int partial = 0;
+        loff_t pos;
+
+        /*
+         * Here we duplicate the generic_commit_write() functionality
+         */
+        pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+        ret = walk_page_buffers(handle, page_buffers(page), from,
+                                to, &partial, commit_write_fn);
+        if (!partial)
+                SetPageUptodate(page);
+        if (pos > inode->i_size)
+                i_size_write(inode, pos);
+        EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
+        if (inode->i_size > EXT3_I(inode)->i_disksize) {
+                EXT3_I(inode)->i_disksize = inode->i_size;
+                ret2 = ext3_mark_inode_dirty(handle, inode);
+                if (!ret) 
+                        ret = ret2;
+        }
+        ret2 = ext3_journal_stop(handle);
+        if (!ret)
+                ret = ret2;
+        return ret;
+}
+
+/* 
+ * bmap() is special.  It gets used by applications such as lilo and by
+ * the swapper to find the on-disk block of a specific piece of data.
+ *
+ * Naturally, this is dangerous if the block concerned is still in the
+ * journal.  If somebody makes a swapfile on an ext3 data-journaling
+ * filesystem and enables swap, then they may get a nasty shock when the
+ * data getting swapped to that swapfile suddenly gets overwritten by
+ * the original zero's written out previously to the journal and
+ * awaiting writeback in the kernel's buffer cache. 
+ *
+ * So, if we see any bmap calls here on a modified, data-journaled file,
+ * take extra steps to flush any blocks which might be in the cache. 
+ */
+static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
+{
+        struct inode *inode = mapping->host;
+        journal_t *journal;
+        int err;
+
+        if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
+                /* 
+                 * This is a REALLY heavyweight approach, but the use of
+                 * bmap on dirty files is expected to be extremely rare:
+                 * only if we run lilo or swapon on a freshly made file
+                 * do we expect this to happen. 
+                 *
+                 * (bmap requires CAP_SYS_RAWIO so this does not
+                 * represent an unprivileged user DOS attack --- we'd be
+                 * in trouble if mortal users could trigger this path at
+                 * will.) 
+                 *
+                 * NB. EXT3_STATE_JDATA is not set on files other than
+                 * regular files.  If somebody wants to bmap a directory
+                 * or symlink and gets confused because the buffer
+                 * hasn't yet been flushed to disk, they deserve
+                 * everything they get.
+                 */
+
+                EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
+                journal = EXT3_JOURNAL(inode);
+                journal_lock_updates(journal);
+                err = journal_flush(journal);
+                journal_unlock_updates(journal);
+
+                if (err)
+                        return 0;
+        }
+
+        return generic_block_bmap(mapping,block,ext3_get_block);
+}
+
+static int bget_one(handle_t *handle, struct buffer_head *bh)
+{
+        get_bh(bh);
+        return 0;
+}
+
+static int bput_one(handle_t *handle, struct buffer_head *bh)
+{
+        put_bh(bh);
+        return 0;
+}
+
+static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
+{
+        if (buffer_mapped(bh))
+                return ext3_journal_dirty_data(handle, bh);
+        return 0;
+}
+
+/*
+ * Note that we always start a transaction even if we're not journalling
+ * data.  This is to preserve ordering: any hole instantiation within
+ * __block_write_full_page -> ext3_get_block() should be journalled
+ * along with the data so we don't crash and then get metadata which
+ * refers to old data.
+ *
+ * In all journalling modes block_write_full_page() will start the I/O.
+ *
+ * Problem:
+ *
+ *      ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
+ *              ext3_writepage()
+ *
+ * Similar for:
+ *
+ *      ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
+ *
+ * Same applies to ext3_get_block().  We will deadlock on various things like
+ * lock_journal and i_truncate_sem.
+ *
+ * Setting PF_MEMALLOC here doesn't work - too many internal memory
+ * allocations fail.
+ *
+ * 16May01: If we're reentered then journal_current_handle() will be
+ *          non-zero. We simply *return*.
+ *
+ * 1 July 2001: @@@ FIXME:
+ *   In journalled data mode, a data buffer may be metadata against the
+ *   current transaction.  But the same file is part of a shared mapping
+ *   and someone does a writepage() on it.
+ *
+ *   We will move the buffer onto the async_data list, but *after* it has
+ *   been dirtied. So there's a small window where we have dirty data on
+ *   BJ_Metadata.
+ *
+ *   Note that this only applies to the last partial page in the file.  The
+ *   bit which block_write_full_page() uses prepare/commit for.  (That's
+ *   broken code anyway: it's wrong for msync()).
+ *
+ *   It's a rare case: affects the final partial page, for journalled data
+ *   where the file is subject to bith write() and writepage() in the same
+ *   transction.  To fix it we'll need a custom block_write_full_page().
+ *   We'll probably need that anyway for journalling writepage() output.
+ *
+ * We don't honour synchronous mounts for writepage().  That would be
+ * disastrous.  Any write() or metadata operation will sync the fs for
+ * us.
+ *
+ * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
+ * we don't need to open a transaction here.
+ */
+static int ext3_ordered_writepage(struct page *page,
+                        struct writeback_control *wbc)
+{
+        struct inode *inode = page->mapping->host;
+        struct buffer_head *page_bufs;
+        handle_t *handle = NULL;
+        int ret = 0;
+        int err;
+
+        J_ASSERT(PageLocked(page));
+
+        /*
+         * We give up here if we're reentered, because it might be for a
+         * different filesystem.
+         */
+        if (ext3_journal_current_handle())
+                goto out_fail;
+
+        handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
+
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                goto out_fail;
+        }
+
+        if (!page_has_buffers(page)) {
+                create_empty_buffers(page, inode->i_sb->s_blocksize,
+                                (1 << BH_Dirty)|(1 << BH_Uptodate));
+        }
+        page_bufs = page_buffers(page);
+        walk_page_buffers(handle, page_bufs, 0,
+                        PAGE_CACHE_SIZE, NULL, bget_one);
+
+        ret = block_write_full_page(page, ext3_get_block, wbc);
+
+        /*
+         * The page can become unlocked at any point now, and
+         * truncate can then come in and change things.  So we
+         * can't touch *page from now on.  But *page_bufs is
+         * safe due to elevated refcount.
+         */
+
+        /*
+         * And attach them to the current transaction.  But only if 
+         * block_write_full_page() succeeded.  Otherwise they are unmapped,
+         * and generally junk.
+         */
+        if (ret == 0) {
+                err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
+                                        NULL, journal_dirty_data_fn);
+                if (!ret)
+                        ret = err;
+        }
+        walk_page_buffers(handle, page_bufs, 0,
+                        PAGE_CACHE_SIZE, NULL, bput_one);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+
+out_fail:
+        redirty_page_for_writepage(wbc, page);
+        unlock_page(page);
+        return ret;
+}
+
+static int
+ext3_writeback_writepage_helper(struct page *page,
+                                struct writeback_control *wbc)
+{
+        return block_write_full_page(page, ext3_get_block, wbc);
+}
+
+static int
+ext3_writeback_writepages(struct address_space *mapping,
+                                struct writeback_control *wbc)
+{
+        struct inode *inode = mapping->host;
+        handle_t *handle = NULL;
+        int err, ret = 0;
+
+        if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+                return ret;
+
+        handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                return ret;
+        }
+
+        ret = __mpage_writepages(mapping, wbc, ext3_writepages_get_block,
+                                        ext3_writeback_writepage_helper);
+
+        /*
+         * Need to reaquire the handle since ext3_writepages_get_block()
+         * can restart the handle
+         */
+        handle = journal_current_handle();
+
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+static int ext3_writeback_writepage(struct page *page,
+                                struct writeback_control *wbc)
+{
+        struct inode *inode = page->mapping->host;
+        handle_t *handle = NULL;
+        int ret = 0;
+        int err;
+
+        if (ext3_journal_current_handle())
+                goto out_fail;
+
+        handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                goto out_fail;
+        }
+
+        if (test_opt(inode->i_sb, NOBH))
+                ret = nobh_writepage(page, ext3_get_block, wbc);
+        else
+                ret = block_write_full_page(page, ext3_get_block, wbc);
+
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+
+out_fail:
+        redirty_page_for_writepage(wbc, page);
+        unlock_page(page);
+        return ret;
+}
+
+static int ext3_journalled_writepage(struct page *page,
+                                struct writeback_control *wbc)
+{
+        struct inode *inode = page->mapping->host;
+        handle_t *handle = NULL;
+        int ret = 0;
+        int err;
+
+        if (ext3_journal_current_handle())
+                goto no_write;
+
+        handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                goto no_write;
+        }
+
+        if (!page_has_buffers(page) || PageChecked(page)) {
+                /*
+                 * It's mmapped pagecache.  Add buffers and journal it.  There
+                 * doesn't seem much point in redirtying the page here.
+                 */
+                ClearPageChecked(page);
+                ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+                                        ext3_get_block);
+                if (ret != 0)
+                        goto out_unlock;
+                ret = walk_page_buffers(handle, page_buffers(page), 0,
+                        PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
+
+                err = walk_page_buffers(handle, page_buffers(page), 0,
+                                PAGE_CACHE_SIZE, NULL, commit_write_fn);
+                if (ret == 0)
+                        ret = err;
+                EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
+                unlock_page(page);
+        } else {
+                /*
+                 * It may be a page full of checkpoint-mode buffers.  We don't
+                 * really know unless we go poke around in the buffer_heads.
+                 * But block_write_full_page will do the right thing.
+                 */
+                ret = block_write_full_page(page, ext3_get_block, wbc);
+        }
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+out:
+        return ret;
+
+no_write:
+        redirty_page_for_writepage(wbc, page);
+out_unlock:
+        unlock_page(page);
+        goto out;
+}
+
+static int ext3_readpage(struct file *file, struct page *page)
+{
+        return mpage_readpage(page, ext3_get_block);
+}
+
+static int
+ext3_readpages(struct file *file, struct address_space *mapping,
+                struct list_head *pages, unsigned nr_pages)
+{
+        return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
+}
+
+static int ext3_invalidatepage(struct page *page, unsigned long offset)
+{
+        journal_t *journal = EXT3_JOURNAL(page->mapping->host);
+
+        /*
+         * If it's a full truncate we just forget about the pending dirtying
+         */
+        if (offset == 0)
+                ClearPageChecked(page);
+
+        return journal_invalidatepage(journal, page, offset);
+}
+
+static int ext3_releasepage(struct page *page, int wait)
+{
+        journal_t *journal = EXT3_JOURNAL(page->mapping->host);
+
+        WARN_ON(PageChecked(page));
+        if (!page_has_buffers(page))
+                return 0;
+        return journal_try_to_free_buffers(journal, page, wait);
+}
+
+/*
+ * If the O_DIRECT write will extend the file then add this inode to the
+ * orphan list.  So recovery will truncate it back to the original size
+ * if the machine crashes during the write.
+ *
+ * If the O_DIRECT write is intantiating holes inside i_size and the machine
+ * crashes then stale disk data _may_ be exposed inside the file.
+ */
+static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
+                        const struct iovec *iov, loff_t offset,
+                        unsigned long nr_segs)
+{
+        struct file *file = iocb->ki_filp;
+        struct inode *inode = file->f_mapping->host;
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        handle_t *handle = NULL;
+        ssize_t ret;
+        int orphan = 0;
+        size_t count = iov_length(iov, nr_segs);
+
+        if (rw == WRITE) {
+                loff_t final_size = offset + count;
+
+                handle = ext3_journal_start(inode, DIO_CREDITS);
+                if (IS_ERR(handle)) {
+                        ret = PTR_ERR(handle);
+                        goto out;
+                }
+                if (final_size > inode->i_size) {
+                        ret = ext3_orphan_add(handle, inode);
+                        if (ret)
+                                goto out_stop;
+                        orphan = 1;
+                        ei->i_disksize = inode->i_size;
+                }
+        }
+
+        ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 
+                                 offset, nr_segs,
+                                 ext3_direct_io_get_blocks, NULL);
+
+        /*
+         * Reacquire the handle: ext3_direct_io_get_block() can restart the
+         * transaction
+         */
+        handle = journal_current_handle();
+
+out_stop:
+        if (handle) {
+                int err;
+
+                if (orphan && inode->i_nlink)
+                        ext3_orphan_del(handle, inode);
+                if (orphan && ret > 0) {
+                        loff_t end = offset + ret;
+                        if (end > inode->i_size) {
+                                ei->i_disksize = end;
+                                i_size_write(inode, end);
+                                /*
+                                 * We're going to return a positive `ret'
+                                 * here due to non-zero-length I/O, so there's
+                                 * no way of reporting error returns from
+                                 * ext3_mark_inode_dirty() to userspace.  So
+                                 * ignore it.
+                                 */
+                                ext3_mark_inode_dirty(handle, inode);
+                        }
+                }
+                err = ext3_journal_stop(handle);
+                if (ret == 0)
+                        ret = err;
+        }
+out:
+        return ret;
+}
+
+/*
+ * Pages can be marked dirty completely asynchronously from ext3's journalling
+ * activity.  By filemap_sync_pte(), try_to_unmap_one(), etc.  We cannot do
+ * much here because ->set_page_dirty is called under VFS locks.  The page is
+ * not necessarily locked.
+ *
+ * We cannot just dirty the page and leave attached buffers clean, because the
+ * buffers' dirty state is "definitive".  We cannot just set the buffers dirty
+ * or jbddirty because all the journalling code will explode.
+ *
+ * So what we do is to mark the page "pending dirty" and next time writepage
+ * is called, propagate that into the buffers appropriately.
+ */
+static int ext3_journalled_set_page_dirty(struct page *page)
+{
+        SetPageChecked(page);
+        return __set_page_dirty_nobuffers(page);
+}
+
+static struct address_space_operations ext3_ordered_aops = {
+        .readpage       = ext3_readpage,
+        .readpages      = ext3_readpages,
+        .writepage      = ext3_ordered_writepage,
+        .sync_page      = block_sync_page,
+        .prepare_write  = ext3_prepare_write,
+        .commit_write   = ext3_ordered_commit_write,
+        .bmap           = ext3_bmap,
+        .invalidatepage = ext3_invalidatepage,
+        .releasepage    = ext3_releasepage,
+        .direct_IO      = ext3_direct_IO,
+};
+
+static struct address_space_operations ext3_writeback_aops = {
+        .readpage       = ext3_readpage,
+        .readpages      = ext3_readpages,
+        .writepage      = ext3_writeback_writepage,
+        .writepages     = ext3_writeback_writepages,
+        .sync_page      = block_sync_page,
+        .prepare_write  = ext3_prepare_write,
+        .commit_write   = ext3_writeback_commit_write,
+        .bmap           = ext3_bmap,
+        .invalidatepage = ext3_invalidatepage,
+        .releasepage    = ext3_releasepage,
+        .direct_IO      = ext3_direct_IO,
+};
+
+static struct address_space_operations ext3_journalled_aops = {
+        .readpage       = ext3_readpage,
+        .readpages      = ext3_readpages,
+        .writepage      = ext3_journalled_writepage,
+        .sync_page      = block_sync_page,
+        .prepare_write  = ext3_prepare_write,
+        .commit_write   = ext3_journalled_commit_write,
+        .set_page_dirty = ext3_journalled_set_page_dirty,
+        .bmap           = ext3_bmap,
+        .invalidatepage = ext3_invalidatepage,
+        .releasepage    = ext3_releasepage,
+};
+
+void ext3_set_aops(struct inode *inode)
+{
+        if (ext3_should_order_data(inode))
+                inode->i_mapping->a_ops = &ext3_ordered_aops;
+        else if (ext3_should_writeback_data(inode))
+                inode->i_mapping->a_ops = &ext3_writeback_aops;
+        else
+                inode->i_mapping->a_ops = &ext3_journalled_aops;
+}
+
+/*
+ * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
+ * up to the end of the block which corresponds to `from'.
+ * This required during truncate. We need to physically zero the tail end
+ * of that block so it doesn't yield old data if the file is later grown.
+ */
+static int ext3_block_truncate_page(handle_t *handle, struct page *page,
+                struct address_space *mapping, loff_t from)
+{
+        unsigned long index = from >> PAGE_CACHE_SHIFT;
+        unsigned offset = from & (PAGE_CACHE_SIZE-1);
+        unsigned blocksize, iblock, length, pos;
+        struct inode *inode = mapping->host;
+        struct buffer_head *bh;
+        int err = 0;
+        void *kaddr;
+
+        blocksize = inode->i_sb->s_blocksize;
+        length = blocksize - (offset & (blocksize - 1));
+        iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+
+        /*
+         * For "nobh" option,  we can only work if we don't need to
+         * read-in the page - otherwise we create buffers to do the IO.
+         */
+        if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH)) {
+                if (PageUptodate(page)) {
+                        kaddr = kmap_atomic(page, KM_USER0);
+                        memset(kaddr + offset, 0, length);
+                        flush_dcache_page(page);
+                        kunmap_atomic(kaddr, KM_USER0);
+                        set_page_dirty(page);
+                        goto unlock;
+                }
+        }
+
+        if (!page_has_buffers(page))
+                create_empty_buffers(page, blocksize, 0);
+
+        /* Find the buffer that contains "offset" */
+        bh = page_buffers(page);
+        pos = blocksize;
+        while (offset >= pos) {
+                bh = bh->b_this_page;
+                iblock++;
+                pos += blocksize;
+        }
+
+        err = 0;
+        if (buffer_freed(bh)) {
+                BUFFER_TRACE(bh, "freed: skip");
+                goto unlock;
+        }
+
+        if (!buffer_mapped(bh)) {
+                BUFFER_TRACE(bh, "unmapped");
+                ext3_get_block(inode, iblock, bh, 0);
+                /* unmapped? It's a hole - nothing to do */
+                if (!buffer_mapped(bh)) {
+                        BUFFER_TRACE(bh, "still unmapped");
+                        goto unlock;
+                }
+        }
+
+        /* Ok, it's mapped. Make sure it's up-to-date */
+        if (PageUptodate(page))
+                set_buffer_uptodate(bh);
+
+        if (!buffer_uptodate(bh)) {
+                err = -EIO;
+                ll_rw_block(READ, 1, &bh);
+                wait_on_buffer(bh);
+                /* Uhhuh. Read error. Complain and punt. */
+                if (!buffer_uptodate(bh))
+                        goto unlock;
+        }
+
+        if (ext3_should_journal_data(inode)) {
+                BUFFER_TRACE(bh, "get write access");
+                err = ext3_journal_get_write_access(handle, bh);
+                if (err)
+                        goto unlock;
+        }
+
+        kaddr = kmap_atomic(page, KM_USER0);
+        memset(kaddr + offset, 0, length);
+        flush_dcache_page(page);
+        kunmap_atomic(kaddr, KM_USER0);
+
+        BUFFER_TRACE(bh, "zeroed end of block");
+
+        err = 0;
+        if (ext3_should_journal_data(inode)) {
+                err = ext3_journal_dirty_metadata(handle, bh);
+        } else {
+                if (ext3_should_order_data(inode))
+                        err = ext3_journal_dirty_data(handle, bh);
+                mark_buffer_dirty(bh);
+        }
+
+unlock:
+        unlock_page(page);
+        page_cache_release(page);
+        return err;
+}
+
+/*
+ * Probably it should be a library function... search for first non-zero word
+ * or memcmp with zero_page, whatever is better for particular architecture.
+ * Linus?
+ */
+static inline int all_zeroes(__le32 *p, __le32 *q)
+{
+        while (p < q)
+                if (*p++)
+                        return 0;
+        return 1;
+}
+
+/**
+ *      ext3_find_shared - find the indirect blocks for partial truncation.
+ *      @inode:   inode in question
+ *      @depth:   depth of the affected branch
+ *      @offsets: offsets of pointers in that branch (see ext3_block_to_path)
+ *      @chain:   place to store the pointers to partial indirect blocks
+ *      @top:     place to the (detached) top of branch
+ *
+ *      This is a helper function used by ext3_truncate().
+ *
+ *      When we do truncate() we may have to clean the ends of several
+ *      indirect blocks but leave the blocks themselves alive. Block is
+ *      partially truncated if some data below the new i_size is refered
+ *      from it (and it is on the path to the first completely truncated
+ *      data block, indeed).  We have to free the top of that path along
+ *      with everything to the right of the path. Since no allocation
+ *      past the truncation point is possible until ext3_truncate()
+ *      finishes, we may safely do the latter, but top of branch may
+ *      require special attention - pageout below the truncation point
+ *      might try to populate it.
+ *
+ *      We atomically detach the top of branch from the tree, store the
+ *      block number of its root in *@top, pointers to buffer_heads of
+ *      partially truncated blocks - in @chain[].bh and pointers to
+ *      their last elements that should not be removed - in
+ *      @chain[].p. Return value is the pointer to last filled element
+ *      of @chain.
+ *
+ *      The work left to caller to do the actual freeing of subtrees:
+ *              a) free the subtree starting from *@top
+ *              b) free the subtrees whose roots are stored in
+ *                      (@chain[i].p+1 .. end of @chain[i].bh->b_data)
+ *              c) free the subtrees growing from the inode past the @chain[0].
+ *                      (no partially truncated stuff there).  */
+
+static Indirect *ext3_find_shared(struct inode *inode,
+                                int depth,
+                                int offsets[4],
+                                Indirect chain[4],
+                                __le32 *top)
+{
+        Indirect *partial, *p;
+        int k, err;
+
+        *top = 0;
+        /* Make k index the deepest non-null offest + 1 */
+        for (k = depth; k > 1 && !offsets[k-1]; k--)
+                ;
+        partial = ext3_get_branch(inode, k, offsets, chain, &err);
+        /* Writer: pointers */
+        if (!partial)
+                partial = chain + k-1;
+        /*
+         * If the branch acquired continuation since we've looked at it -
+         * fine, it should all survive and (new) top doesn't belong to us.
+         */
+        if (!partial->key && *partial->p)
+                /* Writer: end */
+                goto no_top;
+        for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
+                ;
+        /*
+         * OK, we've found the last block that must survive. The rest of our
+         * branch should be detached before unlocking. However, if that rest
+         * of branch is all ours and does not grow immediately from the inode
+         * it's easier to cheat and just decrement partial->p.
+         */
+        if (p == chain + k - 1 && p > chain) {
+                p->p--;
+        } else {
+                *top = *p->p;
+                /* Nope, don't do this in ext3.  Must leave the tree intact */
+#if 0
+                *p->p = 0;
+#endif
+        }
+        /* Writer: end */
+
+        while(partial > p)
+        {
+                brelse(partial->bh);
+                partial--;
+        }
+no_top:
+        return partial;
+}
+
+/*
+ * Zero a number of block pointers in either an inode or an indirect block.
+ * If we restart the transaction we must again get write access to the
+ * indirect block for further modification.
+ *
+ * We release `count' blocks on disk, but (last - first) may be greater
+ * than `count' because there can be holes in there.
+ */
+static void
+ext3_clear_blocks(handle_t *handle, struct inode *inode, struct buffer_head *bh,
+                unsigned long block_to_free, unsigned long count,
+                __le32 *first, __le32 *last)
+{
+        __le32 *p;
+        if (try_to_extend_transaction(handle, inode)) {
+                if (bh) {
+                        BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+                        ext3_journal_dirty_metadata(handle, bh);
+                }
+                ext3_mark_inode_dirty(handle, inode);
+                ext3_journal_test_restart(handle, inode);
+                if (bh) {
+                        BUFFER_TRACE(bh, "retaking write access");
+                        ext3_journal_get_write_access(handle, bh);
+                }
+        }
+
+        /*
+         * Any buffers which are on the journal will be in memory. We find
+         * them on the hash table so journal_revoke() will run journal_forget()
+         * on them.  We've already detached each block from the file, so
+         * bforget() in journal_forget() should be safe.
+         *
+         * AKPM: turn on bforget in journal_forget()!!!
+         */
+        for (p = first; p < last; p++) {
+                u32 nr = le32_to_cpu(*p);
+                if (nr) {
+                        struct buffer_head *bh;
+
+                        *p = 0;
+                        bh = sb_find_get_block(inode->i_sb, nr);
+                        ext3_forget(handle, 0, inode, bh, nr);
+                }
+        }
+
+        ext3_free_blocks(handle, inode, block_to_free, count);
+}
+
+/**
+ * ext3_free_data - free a list of data blocks
+ * @handle:     handle for this transaction
+ * @inode:      inode we are dealing with
+ * @this_bh:    indirect buffer_head which contains *@first and *@last
+ * @first:      array of block numbers
+ * @last:       points immediately past the end of array
+ *
+ * We are freeing all blocks refered from that array (numbers are stored as
+ * little-endian 32-bit) and updating @inode->i_blocks appropriately.
+ *
+ * We accumulate contiguous runs of blocks to free.  Conveniently, if these
+ * blocks are contiguous then releasing them at one time will only affect one
+ * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
+ * actually use a lot of journal space.
+ *
+ * @this_bh will be %NULL if @first and @last point into the inode's direct
+ * block pointers.
+ */
+static void ext3_free_data(handle_t *handle, struct inode *inode,
+                           struct buffer_head *this_bh,
+                           __le32 *first, __le32 *last)
+{
+        unsigned long block_to_free = 0;    /* Starting block # of a run */
+        unsigned long count = 0;            /* Number of blocks in the run */ 
+        __le32 *block_to_free_p = NULL;     /* Pointer into inode/ind
+                                               corresponding to
+                                               block_to_free */
+        unsigned long nr;                   /* Current block # */
+        __le32 *p;                          /* Pointer into inode/ind
+                                               for current block */
+        int err;
+
+        if (this_bh) {                          /* For indirect block */
+                BUFFER_TRACE(this_bh, "get_write_access");
+                err = ext3_journal_get_write_access(handle, this_bh);
+                /* Important: if we can't update the indirect pointers
+                 * to the blocks, we can't free them. */
+                if (err)
+                        return;
+        }
+
+        for (p = first; p < last; p++) {
+                nr = le32_to_cpu(*p);
+                if (nr) {
+                        /* accumulate blocks to free if they're contiguous */
+                        if (count == 0) {
+                                block_to_free = nr;
+                                block_to_free_p = p;
+                                count = 1;
+                        } else if (nr == block_to_free + count) {
+                                count++;
+                        } else {
+                                ext3_clear_blocks(handle, inode, this_bh, 
+                                                  block_to_free,
+                                                  count, block_to_free_p, p);
+                                block_to_free = nr;
+                                block_to_free_p = p;
+                                count = 1;
+                        }
+                }
+        }
+
+        if (count > 0)
+                ext3_clear_blocks(handle, inode, this_bh, block_to_free,
+                                  count, block_to_free_p, p);
+
+        if (this_bh) {
+                BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
+                ext3_journal_dirty_metadata(handle, this_bh);
+        }
+}
+
+/**
+ *      ext3_free_branches - free an array of branches
+ *      @handle: JBD handle for this transaction
+ *      @inode: inode we are dealing with
+ *      @parent_bh: the buffer_head which contains *@first and *@last
+ *      @first: array of block numbers
+ *      @last:  pointer immediately past the end of array
+ *      @depth: depth of the branches to free
+ *
+ *      We are freeing all blocks refered from these branches (numbers are
+ *      stored as little-endian 32-bit) and updating @inode->i_blocks
+ *      appropriately.
+ */
+static void ext3_free_branches(handle_t *handle, struct inode *inode,
+                               struct buffer_head *parent_bh,
+                               __le32 *first, __le32 *last, int depth)
+{
+        unsigned long nr;
+        __le32 *p;
+
+        if (is_handle_aborted(handle))
+                return;
+
+        if (depth--) {
+                struct buffer_head *bh;
+                int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
+                p = last;
+                while (--p >= first) {
+                        nr = le32_to_cpu(*p);
+                        if (!nr)
+                                continue;               /* A hole */
+
+                        /* Go read the buffer for the next level down */
+                        bh = sb_bread(inode->i_sb, nr);
+
+                        /*
+                         * A read failure? Report error and clear slot
+                         * (should be rare).
+                         */
+                        if (!bh) {
+                                ext3_error(inode->i_sb, "ext3_free_branches",
+                                           "Read failure, inode=%ld, block=%ld",
+                                           inode->i_ino, nr);
+                                continue;
+                        }
+
+                        /* This zaps the entire block.  Bottom up. */
+                        BUFFER_TRACE(bh, "free child branches");
+                        ext3_free_branches(handle, inode, bh,
+                                           (__le32*)bh->b_data,
+                                           (__le32*)bh->b_data + addr_per_block,
+                                           depth);
+
+                        /*
+                         * We've probably journalled the indirect block several
+                         * times during the truncate.  But it's no longer
+                         * needed and we now drop it from the transaction via
+                         * journal_revoke().
+                         *
+                         * That's easy if it's exclusively part of this
+                         * transaction.  But if it's part of the committing
+                         * transaction then journal_forget() will simply
+                         * brelse() it.  That means that if the underlying
+                         * block is reallocated in ext3_get_block(),
+                         * unmap_underlying_metadata() will find this block
+                         * and will try to get rid of it.  damn, damn.
+                         *
+                         * If this block has already been committed to the
+                         * journal, a revoke record will be written.  And
+                         * revoke records must be emitted *before* clearing
+                         * this block's bit in the bitmaps.
+                         */
+                        ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
+
+                        /*
+                         * Everything below this this pointer has been
+                         * released.  Now let this top-of-subtree go.
+                         *
+                         * We want the freeing of this indirect block to be
+                         * atomic in the journal with the updating of the
+                         * bitmap block which owns it.  So make some room in
+                         * the journal.
+                         *
+                         * We zero the parent pointer *after* freeing its
+                         * pointee in the bitmaps, so if extend_transaction()
+                         * for some reason fails to put the bitmap changes and
+                         * the release into the same transaction, recovery
+                         * will merely complain about releasing a free block,
+                         * rather than leaking blocks.
+                         */
+                        if (is_handle_aborted(handle))
+                                return;
+                        if (try_to_extend_transaction(handle, inode)) {
+                                ext3_mark_inode_dirty(handle, inode);
+                                ext3_journal_test_restart(handle, inode);
+                        }
+
+                        ext3_free_blocks(handle, inode, nr, 1);
+
+                        if (parent_bh) {
+                                /*
+                                 * The block which we have just freed is
+                                 * pointed to by an indirect block: journal it
+                                 */
+                                BUFFER_TRACE(parent_bh, "get_write_access");
+                                if (!ext3_journal_get_write_access(handle,
+                                                                   parent_bh)){
+                                        *p = 0;
+                                        BUFFER_TRACE(parent_bh,
+                                        "call ext3_journal_dirty_metadata");
+                                        ext3_journal_dirty_metadata(handle, 
+                                                                    parent_bh);
+                                }
+                        }
+                }
+        } else {
+                /* We have reached the bottom of the tree. */
+                BUFFER_TRACE(parent_bh, "free data blocks");
+                ext3_free_data(handle, inode, parent_bh, first, last);
+        }
+}
+
+/*
+ * ext3_truncate()
+ *
+ * We block out ext3_get_block() block instantiations across the entire
+ * transaction, and VFS/VM ensures that ext3_truncate() cannot run
+ * simultaneously on behalf of the same inode.
+ *
+ * As we work through the truncate and commmit bits of it to the journal there
+ * is one core, guiding principle: the file's tree must always be consistent on
+ * disk.  We must be able to restart the truncate after a crash.
+ *
+ * The file's tree may be transiently inconsistent in memory (although it
+ * probably isn't), but whenever we close off and commit a journal transaction,
+ * the contents of (the filesystem + the journal) must be consistent and
+ * restartable.  It's pretty simple, really: bottom up, right to left (although
+ * left-to-right works OK too).
+ *
+ * Note that at recovery time, journal replay occurs *before* the restart of
+ * truncate against the orphan inode list.
+ *
+ * The committed inode has the new, desired i_size (which is the same as
+ * i_disksize in this case).  After a crash, ext3_orphan_cleanup() will see
+ * that this inode's truncate did not complete and it will again call
+ * ext3_truncate() to have another go.  So there will be instantiated blocks
+ * to the right of the truncation point in a crashed ext3 filesystem.  But
+ * that's fine - as long as they are linked from the inode, the post-crash
+ * ext3_truncate() run will find them and release them.
+ */
+
+void ext3_truncate(struct inode * inode)
+{
+        handle_t *handle;
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        __le32 *i_data = ei->i_data;
+        int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
+        struct address_space *mapping = inode->i_mapping;
+        int offsets[4];
+        Indirect chain[4];
+        Indirect *partial;
+        __le32 nr = 0;
+        int n;
+        long last_block;
+        unsigned blocksize = inode->i_sb->s_blocksize;
+        struct page *page;
+
+        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+            S_ISLNK(inode->i_mode)))
+                return;
+        if (ext3_inode_is_fast_symlink(inode))
+                return;
+        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                return;
+
+        /*
+         * We have to lock the EOF page here, because lock_page() nests
+         * outside journal_start().
+         */
+        if ((inode->i_size & (blocksize - 1)) == 0) {
+                /* Block boundary? Nothing to do */
+                page = NULL;
+        } else {
+                page = grab_cache_page(mapping,
+                                inode->i_size >> PAGE_CACHE_SHIFT);
+                if (!page)
+                        return;
+        }
+
+        handle = start_transaction(inode);
+        if (IS_ERR(handle)) {
+                if (page) {
+                        clear_highpage(page);
+                        flush_dcache_page(page);
+                        unlock_page(page);
+                        page_cache_release(page);
+                }
+                return;         /* AKPM: return what? */
+        }
+
+        last_block = (inode->i_size + blocksize-1)
+                                        >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
+
+        if (page)
+                ext3_block_truncate_page(handle, page, mapping, inode->i_size);
+
+        n = ext3_block_to_path(inode, last_block, offsets, NULL);
+        if (n == 0)
+                goto out_stop;  /* error */
+
+        /*
+         * OK.  This truncate is going to happen.  We add the inode to the
+         * orphan list, so that if this truncate spans multiple transactions,
+         * and we crash, we will resume the truncate when the filesystem
+         * recovers.  It also marks the inode dirty, to catch the new size.
+         *
+         * Implication: the file must always be in a sane, consistent
+         * truncatable state while each transaction commits.
+         */
+        if (ext3_orphan_add(handle, inode))
+                goto out_stop;
+
+        /*
+         * The orphan list entry will now protect us from any crash which
+         * occurs before the truncate completes, so it is now safe to propagate
+         * the new, shorter inode size (held for now in i_size) into the
+         * on-disk inode. We do this via i_disksize, which is the value which
+         * ext3 *really* writes onto the disk inode.
+         */
+        ei->i_disksize = inode->i_size;
+
+        /*
+         * From here we block out all ext3_get_block() callers who want to
+         * modify the block allocation tree.
+         */
+        down(&ei->truncate_sem);
+
+        if (n == 1) {           /* direct blocks */
+                ext3_free_data(handle, inode, NULL, i_data+offsets[0],
+                               i_data + EXT3_NDIR_BLOCKS);
+                goto do_indirects;
+        }
+
+        partial = ext3_find_shared(inode, n, offsets, chain, &nr);
+        /* Kill the top of shared branch (not detached) */
+        if (nr) {
+                if (partial == chain) {
+                        /* Shared branch grows from the inode */
+                        ext3_free_branches(handle, inode, NULL,
+                                           &nr, &nr+1, (chain+n-1) - partial);
+                        *partial->p = 0;
+                        /*
+                         * We mark the inode dirty prior to restart,
+                         * and prior to stop.  No need for it here.
+                         */
+                } else {
+                        /* Shared branch grows from an indirect block */
+                        BUFFER_TRACE(partial->bh, "get_write_access");
+                        ext3_free_branches(handle, inode, partial->bh,
+                                        partial->p,
+                                        partial->p+1, (chain+n-1) - partial);
+                }
+        }
+        /* Clear the ends of indirect blocks on the shared branch */
+        while (partial > chain) {
+                ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
+                                   (__le32*)partial->bh->b_data+addr_per_block,
+                                   (chain+n-1) - partial);
+                BUFFER_TRACE(partial->bh, "call brelse");
+                brelse (partial->bh);
+                partial--;
+        }
+do_indirects:
+        /* Kill the remaining (whole) subtrees */
+        switch (offsets[0]) {
+                default:
+                        nr = i_data[EXT3_IND_BLOCK];
+                        if (nr) {
+                                ext3_free_branches(handle, inode, NULL,
+                                                   &nr, &nr+1, 1);
+                                i_data[EXT3_IND_BLOCK] = 0;
+                        }
+                case EXT3_IND_BLOCK:
+                        nr = i_data[EXT3_DIND_BLOCK];
+                        if (nr) {
+                                ext3_free_branches(handle, inode, NULL,
+                                                   &nr, &nr+1, 2);
+                                i_data[EXT3_DIND_BLOCK] = 0;
+                        }
+                case EXT3_DIND_BLOCK:
+                        nr = i_data[EXT3_TIND_BLOCK];
+                        if (nr) {
+                                ext3_free_branches(handle, inode, NULL,
+                                                   &nr, &nr+1, 3);
+                                i_data[EXT3_TIND_BLOCK] = 0;
+                        }
+                case EXT3_TIND_BLOCK:
+                        ;
+        }
+
+        ext3_discard_reservation(inode);
+
+        up(&ei->truncate_sem);
+        inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+        ext3_mark_inode_dirty(handle, inode);
+
+        /* In a multi-transaction truncate, we only make the final
+         * transaction synchronous */
+        if (IS_SYNC(inode))
+                handle->h_sync = 1;
+out_stop:
+        /*
+         * If this was a simple ftruncate(), and the file will remain alive
+         * then we need to clear up the orphan record which we created above.
+         * However, if this was a real unlink then we were called by
+         * ext3_delete_inode(), and we allow that function to clean up the
+         * orphan info for us.
+         */
+        if (inode->i_nlink)
+                ext3_orphan_del(handle, inode);
+
+        ext3_journal_stop(handle);
+}
+
+static unsigned long ext3_get_inode_block(struct super_block *sb,
+                unsigned long ino, struct ext3_iloc *iloc)
+{
+        unsigned long desc, group_desc, block_group;
+        unsigned long offset, block;
+        struct buffer_head *bh;
+        struct ext3_group_desc * gdp;
+
+
+        if ((ino != EXT3_ROOT_INO &&
+                ino != EXT3_JOURNAL_INO &&
+                ino != EXT3_RESIZE_INO &&
+                ino < EXT3_FIRST_INO(sb)) ||
+                ino > le32_to_cpu(
+                        EXT3_SB(sb)->s_es->s_inodes_count)) {
+                ext3_error (sb, "ext3_get_inode_block",
+                            "bad inode number: %lu", ino);
+                return 0;
+        }
+        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
+        if (block_group >= EXT3_SB(sb)->s_groups_count) {
+                ext3_error (sb, "ext3_get_inode_block",
+                            "group >= groups count");
+                return 0;
+        }
+        smp_rmb();
+        group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
+        desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
+        bh = EXT3_SB(sb)->s_group_desc[group_desc];
+        if (!bh) {
+                ext3_error (sb, "ext3_get_inode_block",
+                            "Descriptor not loaded");
+                return 0;
+        }
+
+        gdp = (struct ext3_group_desc *) bh->b_data;
+        /*
+         * Figure out the offset within the block group inode table
+         */
+        offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
+                EXT3_INODE_SIZE(sb);
+        block = le32_to_cpu(gdp[desc].bg_inode_table) +
+                (offset >> EXT3_BLOCK_SIZE_BITS(sb));
+
+        iloc->block_group = block_group;
+        iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
+        return block;
+}
+
+/*
+ * ext3_get_inode_loc returns with an extra refcount against the inode's
+ * underlying buffer_head on success. If 'in_mem' is true, we have all
+ * data in memory that is needed to recreate the on-disk version of this
+ * inode.
+ */
+static int __ext3_get_inode_loc(struct inode *inode,
+                                struct ext3_iloc *iloc, int in_mem)
+{
+        unsigned long block;
+        struct buffer_head *bh;
+
+        block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
+        if (!block)
+                return -EIO;
+
+        bh = sb_getblk(inode->i_sb, block);
+        if (!bh) {
+                ext3_error (inode->i_sb, "ext3_get_inode_loc",
+                                "unable to read inode block - "
+                                "inode=%lu, block=%lu", inode->i_ino, block);
+                return -EIO;
+        }
+        if (!buffer_uptodate(bh)) {
+                lock_buffer(bh);
+                if (buffer_uptodate(bh)) {
+                        /* someone brought it uptodate while we waited */
+                        unlock_buffer(bh);
+                        goto has_buffer;
+                }
+
+                /*
+                 * If we have all information of the inode in memory and this
+                 * is the only valid inode in the block, we need not read the
+                 * block.
+                 */
+                if (in_mem) {
+                        struct buffer_head *bitmap_bh;
+                        struct ext3_group_desc *desc;
+                        int inodes_per_buffer;
+                        int inode_offset, i;
+                        int block_group;
+                        int start;
+
+                        block_group = (inode->i_ino - 1) /
+                                        EXT3_INODES_PER_GROUP(inode->i_sb);
+                        inodes_per_buffer = bh->b_size /
+                                EXT3_INODE_SIZE(inode->i_sb);
+                        inode_offset = ((inode->i_ino - 1) %
+                                        EXT3_INODES_PER_GROUP(inode->i_sb));
+                        start = inode_offset & ~(inodes_per_buffer - 1);
+
+                        /* Is the inode bitmap in cache? */
+                        desc = ext3_get_group_desc(inode->i_sb,
+                                                block_group, NULL);
+                        if (!desc)
+                                goto make_io;
+
+                        bitmap_bh = sb_getblk(inode->i_sb,
+                                        le32_to_cpu(desc->bg_inode_bitmap));
+                        if (!bitmap_bh)
+                                goto make_io;
+
+                        /*
+                         * If the inode bitmap isn't in cache then the
+                         * optimisation may end up performing two reads instead
+                         * of one, so skip it.
+                         */
+                        if (!buffer_uptodate(bitmap_bh)) {
+                                brelse(bitmap_bh);
+                                goto make_io;
+                        }
+                        for (i = start; i < start + inodes_per_buffer; i++) {
+                                if (i == inode_offset)
+                                        continue;
+                                if (ext3_test_bit(i, bitmap_bh->b_data))
+                                        break;
+                        }
+                        brelse(bitmap_bh);
+                        if (i == start + inodes_per_buffer) {
+                                /* all other inodes are free, so skip I/O */
+                                memset(bh->b_data, 0, bh->b_size);
+                                set_buffer_uptodate(bh);
+                                unlock_buffer(bh);
+                                goto has_buffer;
+                        }
+                }
+
+make_io:
+                /*
+                 * There are other valid inodes in the buffer, this inode
+                 * has in-inode xattrs, or we don't have this inode in memory.
+                 * Read the block from disk.
+                 */
+                get_bh(bh);
+                bh->b_end_io = end_buffer_read_sync;
+                submit_bh(READ, bh);
+                wait_on_buffer(bh);
+                if (!buffer_uptodate(bh)) {
+                        ext3_error(inode->i_sb, "ext3_get_inode_loc",
+                                        "unable to read inode block - "
+                                        "inode=%lu, block=%lu",
+                                        inode->i_ino, block);
+                        brelse(bh);
+                        return -EIO;
+                }
+        }
+has_buffer:
+        iloc->bh = bh;
+        return 0;
+}
+
+int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
+{
+        /* We have all inode data except xattrs in memory here. */
+        return __ext3_get_inode_loc(inode, iloc,
+                !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
+}
+
+void ext3_set_inode_flags(struct inode *inode)
+{
+        unsigned int flags = EXT3_I(inode)->i_flags;
+
+        inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
+        if (flags & EXT3_SYNC_FL)
+                inode->i_flags |= S_SYNC;
+        if (flags & EXT3_APPEND_FL)
+                inode->i_flags |= S_APPEND;
+        if (flags & EXT3_IMMUTABLE_FL)
+                inode->i_flags |= S_IMMUTABLE;
+        if (flags & EXT3_NOATIME_FL)
+                inode->i_flags |= S_NOATIME;
+        if (flags & EXT3_DIRSYNC_FL)
+                inode->i_flags |= S_DIRSYNC;
+}
+
+void ext3_read_inode(struct inode * inode)
+{
+        struct ext3_iloc iloc;
+        struct ext3_inode *raw_inode;
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        struct buffer_head *bh;
+        int block;
+
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+        ei->i_acl = EXT3_ACL_NOT_CACHED;
+        ei->i_default_acl = EXT3_ACL_NOT_CACHED;
+#endif
+        ei->i_block_alloc_info = NULL;
+
+        if (__ext3_get_inode_loc(inode, &iloc, 0))
+                goto bad_inode;
+        bh = iloc.bh;
+        raw_inode = ext3_raw_inode(&iloc);
+        inode->i_mode = le16_to_cpu(raw_inode->i_mode);
+        inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
+        inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
+        if(!(test_opt (inode->i_sb, NO_UID32))) {
+                inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
+                inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
+        }
+        inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
+        inode->i_size = le32_to_cpu(raw_inode->i_size);
+        inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
+        inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
+        inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
+        inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
+
+        ei->i_state = 0;
+        ei->i_dir_start_lookup = 0;
+        ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
+        /* We now have enough fields to check if the inode was active or not.
+         * This is needed because nfsd might try to access dead inodes
+         * the test is that same one that e2fsck uses
+         * NeilBrown 1999oct15
+         */
+        if (inode->i_nlink == 0) {
+                if (inode->i_mode == 0 ||
+                    !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
+                        /* this inode is deleted */
+                        brelse (bh);
+                        goto bad_inode;
+                }
+                /* The only unlinked inodes we let through here have
+                 * valid i_mode and are being read by the orphan
+                 * recovery code: that's fine, we're about to complete
+                 * the process of deleting those. */
+        }
+        inode->i_blksize = PAGE_SIZE;   /* This is the optimal IO size
+                                         * (for stat), not the fs block
+                                         * size */  
+        inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
+        ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+#ifdef EXT3_FRAGMENTS
+        ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
+        ei->i_frag_no = raw_inode->i_frag;
+        ei->i_frag_size = raw_inode->i_fsize;
+#endif
+        ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+        if (!S_ISREG(inode->i_mode)) {
+                ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
+        } else {
+                inode->i_size |=
+                        ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
+        }
+        ei->i_disksize = inode->i_size;
+        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
+        ei->i_block_group = iloc.block_group;
+        /*
+         * NOTE! The in-memory inode i_data array is in little-endian order
+         * even on big-endian machines: we do NOT byteswap the block numbers!
+         */
+        for (block = 0; block < EXT3_N_BLOCKS; block++)
+                ei->i_data[block] = raw_inode->i_block[block];
+        INIT_LIST_HEAD(&ei->i_orphan);
+
+        if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
+            EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
+                /*
+                 * When mke2fs creates big inodes it does not zero out
+                 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
+                 * so ignore those first few inodes.
+                 */
+                ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
+                if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
+                    EXT3_INODE_SIZE(inode->i_sb))
+                        goto bad_inode;
+                if (ei->i_extra_isize == 0) {
+                        /* The extra space is currently unused. Use it. */
+                        ei->i_extra_isize = sizeof(struct ext3_inode) -
+                                            EXT3_GOOD_OLD_INODE_SIZE;
+                } else {
+                        __le32 *magic = (void *)raw_inode +
+                                        EXT3_GOOD_OLD_INODE_SIZE +
+                                        ei->i_extra_isize;
+                        if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
+                                 ei->i_state |= EXT3_STATE_XATTR;
+                }
+        } else
+                ei->i_extra_isize = 0;
+
+        if (S_ISREG(inode->i_mode)) {
+                inode->i_op = &ext3_file_inode_operations;
+                inode->i_fop = &ext3_file_operations;
+                ext3_set_aops(inode);
+        } else if (S_ISDIR(inode->i_mode)) {
+                inode->i_op = &ext3_dir_inode_operations;
+                inode->i_fop = &ext3_dir_operations;
+        } else if (S_ISLNK(inode->i_mode)) {
+                if (ext3_inode_is_fast_symlink(inode))
+                        inode->i_op = &ext3_fast_symlink_inode_operations;
+                else {
+                        inode->i_op = &ext3_symlink_inode_operations;
+                        ext3_set_aops(inode);
+                }
+        } else {
+                inode->i_op = &ext3_special_inode_operations;
+                if (raw_inode->i_block[0])
+                        init_special_inode(inode, inode->i_mode,
+                           old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
+                else 
+                        init_special_inode(inode, inode->i_mode,
+                           new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+        }
+        brelse (iloc.bh);
+        ext3_set_inode_flags(inode);
+        return;
+
+bad_inode:
+        make_bad_inode(inode);
+        return;
+}
+
+/*
+ * Post the struct inode info into an on-disk inode location in the
+ * buffer-cache.  This gobbles the caller's reference to the
+ * buffer_head in the inode location struct.
+ *
+ * The caller must have write access to iloc->bh.
+ */
+static int ext3_do_update_inode(handle_t *handle, 
+                                struct inode *inode, 
+                                struct ext3_iloc *iloc)
+{
+        struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        struct buffer_head *bh = iloc->bh;
+        int err = 0, rc, block;
+
+        /* For fields not not tracking in the in-memory inode,
+         * initialise them to zero for new inodes. */
+        if (ei->i_state & EXT3_STATE_NEW)
+                memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
+
+        raw_inode->i_mode = cpu_to_le16(inode->i_mode);
+        if(!(test_opt(inode->i_sb, NO_UID32))) {
+                raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
+                raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
+/*
+ * Fix up interoperability with old kernels. Otherwise, old inodes get
+ * re-used with the upper 16 bits of the uid/gid intact
+ */
+                if(!ei->i_dtime) {
+                        raw_inode->i_uid_high =
+                                cpu_to_le16(high_16_bits(inode->i_uid));
+                        raw_inode->i_gid_high =
+                                cpu_to_le16(high_16_bits(inode->i_gid));
+                } else {
+                        raw_inode->i_uid_high = 0;
+                        raw_inode->i_gid_high = 0;
+                }
+        } else {
+                raw_inode->i_uid_low =
+                        cpu_to_le16(fs_high2lowuid(inode->i_uid));
+                raw_inode->i_gid_low =
+                        cpu_to_le16(fs_high2lowgid(inode->i_gid));
+                raw_inode->i_uid_high = 0;
+                raw_inode->i_gid_high = 0;
+        }
+        raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
+        raw_inode->i_size = cpu_to_le32(ei->i_disksize);
+        raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
+        raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+        raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+        raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
+        raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
+        raw_inode->i_flags = cpu_to_le32(ei->i_flags);
+#ifdef EXT3_FRAGMENTS
+        raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
+        raw_inode->i_frag = ei->i_frag_no;
+        raw_inode->i_fsize = ei->i_frag_size;
+#endif
+        raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
+        if (!S_ISREG(inode->i_mode)) {
+                raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
+        } else {
+                raw_inode->i_size_high =
+                        cpu_to_le32(ei->i_disksize >> 32);
+                if (ei->i_disksize > 0x7fffffffULL) {
+                        struct super_block *sb = inode->i_sb;
+                        if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
+                                        EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
+                            EXT3_SB(sb)->s_es->s_rev_level ==
+                                        cpu_to_le32(EXT3_GOOD_OLD_REV)) {
+                               /* If this is the first large file
+                                * created, add a flag to the superblock.
+                                */
+                                err = ext3_journal_get_write_access(handle,
+                                                EXT3_SB(sb)->s_sbh);
+                                if (err)
+                                        goto out_brelse;
+                                ext3_update_dynamic_rev(sb);
+                                EXT3_SET_RO_COMPAT_FEATURE(sb,
+                                        EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
+                                sb->s_dirt = 1;
+                                handle->h_sync = 1;
+                                err = ext3_journal_dirty_metadata(handle,
+                                                EXT3_SB(sb)->s_sbh);
+                        }
+                }
+        }
+        raw_inode->i_generation = cpu_to_le32(inode->i_generation);
+        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+                if (old_valid_dev(inode->i_rdev)) {
+                        raw_inode->i_block[0] =
+                                cpu_to_le32(old_encode_dev(inode->i_rdev));
+                        raw_inode->i_block[1] = 0;
+                } else {
+                        raw_inode->i_block[0] = 0;
+                        raw_inode->i_block[1] =
+                                cpu_to_le32(new_encode_dev(inode->i_rdev));
+                        raw_inode->i_block[2] = 0;
+                }
+        } else for (block = 0; block < EXT3_N_BLOCKS; block++)
+                raw_inode->i_block[block] = ei->i_data[block];
+
+        if (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE)
+                raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
+
+        BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+        rc = ext3_journal_dirty_metadata(handle, bh);
+        if (!err)
+                err = rc;
+        ei->i_state &= ~EXT3_STATE_NEW;
+
+out_brelse:
+        brelse (bh);
+        ext3_std_error(inode->i_sb, err);
+        return err;
+}
+
+/*
+ * ext3_write_inode()
+ *
+ * We are called from a few places:
+ *
+ * - Within generic_file_write() for O_SYNC files.
+ *   Here, there will be no transaction running. We wait for any running
+ *   trasnaction to commit.
+ *
+ * - Within sys_sync(), kupdate and such.
+ *   We wait on commit, if tol to.
+ *
+ * - Within prune_icache() (PF_MEMALLOC == true)
+ *   Here we simply return.  We can't afford to block kswapd on the
+ *   journal commit.
+ *
+ * In all cases it is actually safe for us to return without doing anything,
+ * because the inode has been copied into a raw inode buffer in
+ * ext3_mark_inode_dirty().  This is a correctness thing for O_SYNC and for
+ * knfsd.
+ *
+ * Note that we are absolutely dependent upon all inode dirtiers doing the
+ * right thing: they *must* call mark_inode_dirty() after dirtying info in
+ * which we are interested.
+ *
+ * It would be a bug for them to not do this.  The code:
+ *
+ *      mark_inode_dirty(inode)
+ *      stuff();
+ *      inode->i_size = expr;
+ *
+ * is in error because a kswapd-driven write_inode() could occur while
+ * `stuff()' is running, and the new i_size will be lost.  Plus the inode
+ * will no longer be on the superblock's dirty inode list.
+ */
+int ext3_write_inode(struct inode *inode, int wait)
+{
+        if (current->flags & PF_MEMALLOC)
+                return 0;
+
+        if (ext3_journal_current_handle()) {
+                jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
+                dump_stack();
+                return -EIO;
+        }
+
+        if (!wait)
+                return 0;
+
+        return ext3_force_commit(inode->i_sb);
+}
+
+/*
+ * ext3_setattr()
+ *
+ * Called from notify_change.
+ *
+ * We want to trap VFS attempts to truncate the file as soon as
+ * possible.  In particular, we want to make sure that when the VFS
+ * shrinks i_size, we put the inode on the orphan list and modify
+ * i_disksize immediately, so that during the subsequent flushing of
+ * dirty pages and freeing of disk blocks, we can guarantee that any
+ * commit will leave the blocks being flushed in an unused state on
+ * disk.  (On recovery, the inode will get truncated and the blocks will
+ * be freed, so we have a strong guarantee that no future commit will
+ * leave these blocks visible to the user.)  
+ *
+ * Called with inode->sem down.
+ */
+int ext3_setattr(struct dentry *dentry, struct iattr *attr)
+{
+        struct inode *inode = dentry->d_inode;
+        int error, rc = 0;
+        const unsigned int ia_valid = attr->ia_valid;
+
+        error = inode_change_ok(inode, attr);
+        if (error)
+                return error;
+
+        if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
+                (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
+                handle_t *handle;
+
+                /* (user+group)*(old+new) structure, inode write (sb,
+                 * inode block, ? - but truncate inode update has it) */
+                handle = ext3_journal_start(inode, 4*EXT3_QUOTA_INIT_BLOCKS+3);
+                if (IS_ERR(handle)) {
+                        error = PTR_ERR(handle);
+                        goto err_out;
+                }
+                error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
+                if (error) {
+                        ext3_journal_stop(handle);
+                        return error;
+                }
+                /* Update corresponding info in inode so that everything is in
+                 * one transaction */
+                if (attr->ia_valid & ATTR_UID)
+                        inode->i_uid = attr->ia_uid;
+                if (attr->ia_valid & ATTR_GID)
+                        inode->i_gid = attr->ia_gid;
+                error = ext3_mark_inode_dirty(handle, inode);
+                ext3_journal_stop(handle);
+        }
+
+        if (S_ISREG(inode->i_mode) &&
+            attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
+                handle_t *handle;
+
+                handle = ext3_journal_start(inode, 3);
+                if (IS_ERR(handle)) {
+                        error = PTR_ERR(handle);
+                        goto err_out;
+                }
+
+                error = ext3_orphan_add(handle, inode);
+                EXT3_I(inode)->i_disksize = attr->ia_size;
+                rc = ext3_mark_inode_dirty(handle, inode);
+                if (!error)
+                        error = rc;
+                ext3_journal_stop(handle);
+        }
+
+        rc = inode_setattr(inode, attr);
+
+        /* If inode_setattr's call to ext3_truncate failed to get a
+         * transaction handle at all, we need to clean up the in-core
+         * orphan list manually. */
+        if (inode->i_nlink)
+                ext3_orphan_del(NULL, inode);
+
+        if (!rc && (ia_valid & ATTR_MODE))
+                rc = ext3_acl_chmod(inode);
+
+err_out:
+        ext3_std_error(inode->i_sb, error);
+        if (!error)
+                error = rc;
+        return error;
+}
+
+
+/*
+ * akpm: how many blocks doth make a writepage()?
+ *
+ * With N blocks per page, it may be:
+ * N data blocks
+ * 2 indirect block
+ * 2 dindirect
+ * 1 tindirect
+ * N+5 bitmap blocks (from the above)
+ * N+5 group descriptor summary blocks
+ * 1 inode block
+ * 1 superblock.
+ * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
+ *
+ * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
+ *
+ * With ordered or writeback data it's the same, less the N data blocks.
+ *
+ * If the inode's direct blocks can hold an integral number of pages then a
+ * page cannot straddle two indirect blocks, and we can only touch one indirect
+ * and dindirect block, and the "5" above becomes "3".
+ *
+ * This still overestimates under most circumstances.  If we were to pass the
+ * start and end offsets in here as well we could do block_to_path() on each
+ * block and work out the exact number of indirects which are touched.  Pah.
+ */
+
+static int ext3_writepage_trans_blocks(struct inode *inode)
+{
+        int bpp = ext3_journal_blocks_per_page(inode);
+        int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
+        int ret;
+
+        if (ext3_should_journal_data(inode))
+                ret = 3 * (bpp + indirects) + 2;
+        else
+                ret = 2 * (bpp + indirects) + 2;
+
+#ifdef CONFIG_QUOTA
+        /* We know that structure was already allocated during DQUOT_INIT so
+         * we will be updating only the data blocks + inodes */
+        ret += 2*EXT3_QUOTA_TRANS_BLOCKS;
+#endif
+
+        return ret;
+}
+
+/*
+ * The caller must have previously called ext3_reserve_inode_write().
+ * Give this, we know that the caller already has write access to iloc->bh.
+ */
+int ext3_mark_iloc_dirty(handle_t *handle,
+                struct inode *inode, struct ext3_iloc *iloc)
+{
+        int err = 0;
+
+        /* the do_update_inode consumes one bh->b_count */
+        get_bh(iloc->bh);
+
+        /* ext3_do_update_inode() does journal_dirty_metadata */
+        err = ext3_do_update_inode(handle, inode, iloc);
+        put_bh(iloc->bh);
+        return err;
+}
+
+/* 
+ * On success, We end up with an outstanding reference count against
+ * iloc->bh.  This _must_ be cleaned up later. 
+ */
+
+int
+ext3_reserve_inode_write(handle_t *handle, struct inode *inode, 
+                         struct ext3_iloc *iloc)
+{
+        int err = 0;
+        if (handle) {
+                err = ext3_get_inode_loc(inode, iloc);
+                if (!err) {
+                        BUFFER_TRACE(iloc->bh, "get_write_access");
+                        err = ext3_journal_get_write_access(handle, iloc->bh);
+                        if (err) {
+                                brelse(iloc->bh);
+                                iloc->bh = NULL;
+                        }
+                }
+        }
+        ext3_std_error(inode->i_sb, err);
+        return err;
+}
+
+/*
+ * akpm: What we do here is to mark the in-core inode as clean
+ * with respect to inode dirtiness (it may still be data-dirty).
+ * This means that the in-core inode may be reaped by prune_icache
+ * without having to perform any I/O.  This is a very good thing,
+ * because *any* task may call prune_icache - even ones which
+ * have a transaction open against a different journal.
+ *
+ * Is this cheating?  Not really.  Sure, we haven't written the
+ * inode out, but prune_icache isn't a user-visible syncing function.
+ * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
+ * we start and wait on commits.
+ *
+ * Is this efficient/effective?  Well, we're being nice to the system
+ * by cleaning up our inodes proactively so they can be reaped
+ * without I/O.  But we are potentially leaving up to five seconds'
+ * worth of inodes floating about which prune_icache wants us to
+ * write out.  One way to fix that would be to get prune_icache()
+ * to do a write_super() to free up some memory.  It has the desired
+ * effect.
+ */
+int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
+{
+        struct ext3_iloc iloc;
+        int err;
+
+        might_sleep();
+        err = ext3_reserve_inode_write(handle, inode, &iloc);
+        if (!err)
+                err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+        return err;
+}
+
+/*
+ * akpm: ext3_dirty_inode() is called from __mark_inode_dirty()
+ *
+ * We're really interested in the case where a file is being extended.
+ * i_size has been changed by generic_commit_write() and we thus need
+ * to include the updated inode in the current transaction.
+ *
+ * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
+ * are allocated to the file.
+ *
+ * If the inode is marked synchronous, we don't honour that here - doing
+ * so would cause a commit on atime updates, which we don't bother doing.
+ * We handle synchronous inodes at the highest possible level.
+ */
+void ext3_dirty_inode(struct inode *inode)
+{
+        handle_t *current_handle = ext3_journal_current_handle();
+        handle_t *handle;
+
+        handle = ext3_journal_start(inode, 2);
+        if (IS_ERR(handle))
+                goto out;
+        if (current_handle &&
+                current_handle->h_transaction != handle->h_transaction) {
+                /* This task has a transaction open against a different fs */
+                printk(KERN_EMERG "%s: transactions do not match!\n",
+                       __FUNCTION__);
+        } else {
+                jbd_debug(5, "marking dirty.  outer handle=%p\n",
+                                current_handle);
+                ext3_mark_inode_dirty(handle, inode);
+        }
+        ext3_journal_stop(handle);
+out:
+        return;
+}
+
+#ifdef AKPM
+/* 
+ * Bind an inode's backing buffer_head into this transaction, to prevent
+ * it from being flushed to disk early.  Unlike
+ * ext3_reserve_inode_write, this leaves behind no bh reference and
+ * returns no iloc structure, so the caller needs to repeat the iloc
+ * lookup to mark the inode dirty later.
+ */
+static inline int
+ext3_pin_inode(handle_t *handle, struct inode *inode)
+{
+        struct ext3_iloc iloc;
+
+        int err = 0;
+        if (handle) {
+                err = ext3_get_inode_loc(inode, &iloc);
+                if (!err) {
+                        BUFFER_TRACE(iloc.bh, "get_write_access");
+                        err = journal_get_write_access(handle, iloc.bh);
+                        if (!err)
+                                err = ext3_journal_dirty_metadata(handle, 
+                                                                  iloc.bh);
+                        brelse(iloc.bh);
+                }
+        }
+        ext3_std_error(inode->i_sb, err);
+        return err;
+}
+#endif
+
+int ext3_change_inode_journal_flag(struct inode *inode, int val)
+{
+        journal_t *journal;
+        handle_t *handle;
+        int err;
+
+        /*
+         * We have to be very careful here: changing a data block's
+         * journaling status dynamically is dangerous.  If we write a
+         * data block to the journal, change the status and then delete
+         * that block, we risk forgetting to revoke the old log record
+         * from the journal and so a subsequent replay can corrupt data.
+         * So, first we make sure that the journal is empty and that
+         * nobody is changing anything.
+         */
+
+        journal = EXT3_JOURNAL(inode);
+        if (is_journal_aborted(journal) || IS_RDONLY(inode))
+                return -EROFS;
+
+        journal_lock_updates(journal);
+        journal_flush(journal);
+
+        /*
+         * OK, there are no updates running now, and all cached data is
+         * synced to disk.  We are now in a completely consistent state
+         * which doesn't have anything in the journal, and we know that
+         * no filesystem updates are running, so it is safe to modify
+         * the inode's in-core data-journaling state flag now.
+         */
+
+        if (val)
+                EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
+        else
+                EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
+        ext3_set_aops(inode);
+
+        journal_unlock_updates(journal);
+
+        /* Finally we can mark the inode as dirty. */
+
+        handle = ext3_journal_start(inode, 1);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        err = ext3_mark_inode_dirty(handle, inode);
+        handle->h_sync = 1;
+        ext3_journal_stop(handle);
+        ext3_std_error(inode->i_sb, err);
+
+        return err;
+}
diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c
new file mode 100644
index 000000000000..706d68608381
--- /dev/null
+++ b/fs/ext3/ioctl.c
@@ -0,0 +1,243 @@
+/*
+ * linux/fs/ext3/ioctl.c
+ *
+ * Copyright (C) 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/time.h>
+#include <asm/uaccess.h>
+
+
+int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
+                unsigned long arg)
+{
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        unsigned int flags;
+        unsigned short rsv_window_size;
+
+        ext3_debug ("cmd = %u, arg = %lu\n", cmd, arg);
+
+        switch (cmd) {
+        case EXT3_IOC_GETFLAGS:
+                flags = ei->i_flags & EXT3_FL_USER_VISIBLE;
+                return put_user(flags, (int __user *) arg);
+        case EXT3_IOC_SETFLAGS: {
+                handle_t *handle = NULL;
+                int err;
+                struct ext3_iloc iloc;
+                unsigned int oldflags;
+                unsigned int jflag;
+
+                if (IS_RDONLY(inode))
+                        return -EROFS;
+
+                if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+                        return -EACCES;
+
+                if (get_user(flags, (int __user *) arg))
+                        return -EFAULT;
+
+                if (!S_ISDIR(inode->i_mode))
+                        flags &= ~EXT3_DIRSYNC_FL;
+
+                oldflags = ei->i_flags;
+
+                /* The JOURNAL_DATA flag is modifiable only by root */
+                jflag = flags & EXT3_JOURNAL_DATA_FL;
+
+                /*
+                 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
+                 * the relevant capability.
+                 *
+                 * This test looks nicer. Thanks to Pauline Middelink
+                 */
+                if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
+                        if (!capable(CAP_LINUX_IMMUTABLE))
+                                return -EPERM;
+                }
+
+                /*
+                 * The JOURNAL_DATA flag can only be changed by
+                 * the relevant capability.
+                 */
+                if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
+                        if (!capable(CAP_SYS_RESOURCE))
+                                return -EPERM;
+                }
+
+
+                handle = ext3_journal_start(inode, 1);
+                if (IS_ERR(handle))
+                        return PTR_ERR(handle);
+                if (IS_SYNC(inode))
+                        handle->h_sync = 1;
+                err = ext3_reserve_inode_write(handle, inode, &iloc);
+                if (err)
+                        goto flags_err;
+
+                flags = flags & EXT3_FL_USER_MODIFIABLE;
+                flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
+                ei->i_flags = flags;
+
+                ext3_set_inode_flags(inode);
+                inode->i_ctime = CURRENT_TIME_SEC;
+
+                err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+flags_err:
+                ext3_journal_stop(handle);
+                if (err)
+                        return err;
+
+                if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
+                        err = ext3_change_inode_journal_flag(inode, jflag);
+                return err;
+        }
+        case EXT3_IOC_GETVERSION:
+        case EXT3_IOC_GETVERSION_OLD:
+                return put_user(inode->i_generation, (int __user *) arg);
+        case EXT3_IOC_SETVERSION:
+        case EXT3_IOC_SETVERSION_OLD: {
+                handle_t *handle;
+                struct ext3_iloc iloc;
+                __u32 generation;
+                int err;
+
+                if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+                        return -EPERM;
+                if (IS_RDONLY(inode))
+                        return -EROFS;
+                if (get_user(generation, (int __user *) arg))
+                        return -EFAULT;
+
+                handle = ext3_journal_start(inode, 1);
+                if (IS_ERR(handle))
+                        return PTR_ERR(handle);
+                err = ext3_reserve_inode_write(handle, inode, &iloc);
+                if (err == 0) {
+                        inode->i_ctime = CURRENT_TIME_SEC;
+                        inode->i_generation = generation;
+                        err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+                }
+                ext3_journal_stop(handle);
+                return err;
+        }
+#ifdef CONFIG_JBD_DEBUG
+        case EXT3_IOC_WAIT_FOR_READONLY:
+                /*
+                 * This is racy - by the time we're woken up and running,
+                 * the superblock could be released.  And the module could
+                 * have been unloaded.  So sue me.
+                 *
+                 * Returns 1 if it slept, else zero.
+                 */
+                {
+                        struct super_block *sb = inode->i_sb;
+                        DECLARE_WAITQUEUE(wait, current);
+                        int ret = 0;
+
+                        set_current_state(TASK_INTERRUPTIBLE);
+                        add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
+                        if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
+                                schedule();
+                                ret = 1;
+                        }
+                        remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
+                        return ret;
+                }
+#endif
+        case EXT3_IOC_GETRSVSZ:
+                if (test_opt(inode->i_sb, RESERVATION)
+                        && S_ISREG(inode->i_mode)
+                        && ei->i_block_alloc_info) {
+                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
+                        return put_user(rsv_window_size, (int __user *)arg);
+                }
+                return -ENOTTY;
+        case EXT3_IOC_SETRSVSZ: {
+
+                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
+                        return -ENOTTY;
+
+                if (IS_RDONLY(inode))
+                        return -EROFS;
+
+                if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+                        return -EACCES;
+
+                if (get_user(rsv_window_size, (int __user *)arg))
+                        return -EFAULT;
+
+                if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
+                        rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
+
+                /*
+                 * need to allocate reservation structure for this inode
+                 * before set the window size
+                 */
+                down(&ei->truncate_sem);
+                if (!ei->i_block_alloc_info)
+                        ext3_init_block_alloc_info(inode);
+
+                if (ei->i_block_alloc_info){
+                        struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
+                        rsv->rsv_goal_size = rsv_window_size;
+                }
+                up(&ei->truncate_sem);
+                return 0;
+        }
+        case EXT3_IOC_GROUP_EXTEND: {
+                unsigned long n_blocks_count;
+                struct super_block *sb = inode->i_sb;
+                int err;
+
+                if (!capable(CAP_SYS_RESOURCE))
+                        return -EPERM;
+
+                if (IS_RDONLY(inode))
+                        return -EROFS;
+
+                if (get_user(n_blocks_count, (__u32 __user *)arg))
+                        return -EFAULT;
+
+                err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
+                journal_lock_updates(EXT3_SB(sb)->s_journal);
+                journal_flush(EXT3_SB(sb)->s_journal);
+                journal_unlock_updates(EXT3_SB(sb)->s_journal);
+
+                return err;
+        }
+        case EXT3_IOC_GROUP_ADD: {
+                struct ext3_new_group_data input;
+                struct super_block *sb = inode->i_sb;
+                int err;
+
+                if (!capable(CAP_SYS_RESOURCE))
+                        return -EPERM;
+
+                if (IS_RDONLY(inode))
+                        return -EROFS;
+
+                if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
+                                sizeof(input)))
+                        return -EFAULT;
+
+                err = ext3_group_add(sb, &input);
+                journal_lock_updates(EXT3_SB(sb)->s_journal);
+                journal_flush(EXT3_SB(sb)->s_journal);
+                journal_unlock_updates(EXT3_SB(sb)->s_journal);
+
+                return err;
+        }
+
+
+        default:
+                return -ENOTTY;
+        }
+}
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
new file mode 100644
index 000000000000..79742d824a0a
--- /dev/null
+++ b/fs/ext3/namei.c
@@ -0,0 +1,2378 @@
+/*
+ *  linux/fs/ext3/namei.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/namei.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *  Directory entry file type support and forward compatibility hooks
+ *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
+ *  Hash Tree Directory indexing (c)
+ *      Daniel Phillips, 2001
+ *  Hash Tree Directory indexing porting
+ *      Christopher Li, 2002
+ *  Hash Tree Directory indexing cleanup
+ *      Theodore Ts'o, 2002
+ */
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/jbd.h>
+#include <linux/time.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/smp_lock.h>
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * define how far ahead to read directories while searching them.
+ */
+#define NAMEI_RA_CHUNKS  2
+#define NAMEI_RA_BLOCKS  4
+#define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
+#define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
+
+static struct buffer_head *ext3_append(handle_t *handle,
+                                        struct inode *inode,
+                                        u32 *block, int *err)
+{
+        struct buffer_head *bh;
+
+        *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
+
+        if ((bh = ext3_bread(handle, inode, *block, 1, err))) {
+                inode->i_size += inode->i_sb->s_blocksize;
+                EXT3_I(inode)->i_disksize = inode->i_size;
+                ext3_journal_get_write_access(handle,bh);
+        }
+        return bh;
+}
+
+#ifndef assert
+#define assert(test) J_ASSERT(test)
+#endif
+
+#ifndef swap
+#define swap(x, y) do { typeof(x) z = x; x = y; y = z; } while (0)
+#endif
+
+#ifdef DX_DEBUG
+#define dxtrace(command) command
+#else
+#define dxtrace(command) 
+#endif
+
+struct fake_dirent
+{
+        __le32 inode;
+        __le16 rec_len;
+        u8 name_len;
+        u8 file_type;
+};
+
+struct dx_countlimit
+{
+        __le16 limit;
+        __le16 count;
+};
+
+struct dx_entry
+{
+        __le32 hash;
+        __le32 block;
+};
+
+/*
+ * dx_root_info is laid out so that if it should somehow get overlaid by a
+ * dirent the two low bits of the hash version will be zero.  Therefore, the
+ * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
+ */
+
+struct dx_root
+{
+        struct fake_dirent dot;
+        char dot_name[4];
+        struct fake_dirent dotdot;
+        char dotdot_name[4];
+        struct dx_root_info
+        {
+                __le32 reserved_zero;
+                u8 hash_version;
+                u8 info_length; /* 8 */
+                u8 indirect_levels;
+                u8 unused_flags;
+        }
+        info;
+        struct dx_entry entries[0];
+};
+
+struct dx_node
+{
+        struct fake_dirent fake;
+        struct dx_entry entries[0];
+};
+
+
+struct dx_frame
+{
+        struct buffer_head *bh;
+        struct dx_entry *entries;
+        struct dx_entry *at;
+};
+
+struct dx_map_entry
+{
+        u32 hash;
+        u32 offs;
+};
+
+#ifdef CONFIG_EXT3_INDEX
+static inline unsigned dx_get_block (struct dx_entry *entry);
+static void dx_set_block (struct dx_entry *entry, unsigned value);
+static inline unsigned dx_get_hash (struct dx_entry *entry);
+static void dx_set_hash (struct dx_entry *entry, unsigned value);
+static unsigned dx_get_count (struct dx_entry *entries);
+static unsigned dx_get_limit (struct dx_entry *entries);
+static void dx_set_count (struct dx_entry *entries, unsigned value);
+static void dx_set_limit (struct dx_entry *entries, unsigned value);
+static unsigned dx_root_limit (struct inode *dir, unsigned infosize);
+static unsigned dx_node_limit (struct inode *dir);
+static struct dx_frame *dx_probe(struct dentry *dentry,
+                                 struct inode *dir,
+                                 struct dx_hash_info *hinfo,
+                                 struct dx_frame *frame,
+                                 int *err);
+static void dx_release (struct dx_frame *frames);
+static int dx_make_map (struct ext3_dir_entry_2 *de, int size,
+                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
+static void dx_sort_map(struct dx_map_entry *map, unsigned count);
+static struct ext3_dir_entry_2 *dx_move_dirents (char *from, char *to,
+                struct dx_map_entry *offsets, int count);
+static struct ext3_dir_entry_2* dx_pack_dirents (char *base, int size);
+static void dx_insert_block (struct dx_frame *frame, u32 hash, u32 block);
+static int ext3_htree_next_block(struct inode *dir, __u32 hash,
+                                 struct dx_frame *frame,
+                                 struct dx_frame *frames, 
+                                 __u32 *start_hash);
+static struct buffer_head * ext3_dx_find_entry(struct dentry *dentry,
+                       struct ext3_dir_entry_2 **res_dir, int *err);
+static int ext3_dx_add_entry(handle_t *handle, struct dentry *dentry,
+                             struct inode *inode);
+
+/*
+ * Future: use high four bits of block for coalesce-on-delete flags
+ * Mask them off for now.
+ */
+
+static inline unsigned dx_get_block (struct dx_entry *entry)
+{
+        return le32_to_cpu(entry->block) & 0x00ffffff;
+}
+
+static inline void dx_set_block (struct dx_entry *entry, unsigned value)
+{
+        entry->block = cpu_to_le32(value);
+}
+
+static inline unsigned dx_get_hash (struct dx_entry *entry)
+{
+        return le32_to_cpu(entry->hash);
+}
+
+static inline void dx_set_hash (struct dx_entry *entry, unsigned value)
+{
+        entry->hash = cpu_to_le32(value);
+}
+
+static inline unsigned dx_get_count (struct dx_entry *entries)
+{
+        return le16_to_cpu(((struct dx_countlimit *) entries)->count);
+}
+
+static inline unsigned dx_get_limit (struct dx_entry *entries)
+{
+        return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
+}
+
+static inline void dx_set_count (struct dx_entry *entries, unsigned value)
+{
+        ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
+}
+
+static inline void dx_set_limit (struct dx_entry *entries, unsigned value)
+{
+        ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
+}
+
+static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize)
+{
+        unsigned entry_space = dir->i_sb->s_blocksize - EXT3_DIR_REC_LEN(1) -
+                EXT3_DIR_REC_LEN(2) - infosize;
+        return 0? 20: entry_space / sizeof(struct dx_entry);
+}
+
+static inline unsigned dx_node_limit (struct inode *dir)
+{
+        unsigned entry_space = dir->i_sb->s_blocksize - EXT3_DIR_REC_LEN(0);
+        return 0? 22: entry_space / sizeof(struct dx_entry);
+}
+
+/*
+ * Debug
+ */
+#ifdef DX_DEBUG
+static void dx_show_index (char * label, struct dx_entry *entries)
+{
+        int i, n = dx_get_count (entries);
+        printk("%s index ", label);
+        for (i = 0; i < n; i++)
+        {
+                printk("%x->%u ", i? dx_get_hash(entries + i): 0, dx_get_block(entries + i));
+        }
+        printk("\n");
+}
+
+struct stats
+{ 
+        unsigned names;
+        unsigned space;
+        unsigned bcount;
+};
+
+static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext3_dir_entry_2 *de,
+                                 int size, int show_names)
+{
+        unsigned names = 0, space = 0;
+        char *base = (char *) de;
+        struct dx_hash_info h = *hinfo;
+
+        printk("names: ");
+        while ((char *) de < base + size)
+        {
+                if (de->inode)
+                {
+                        if (show_names)
+                        {
+                                int len = de->name_len;
+                                char *name = de->name;
+                                while (len--) printk("%c", *name++);
+                                ext3fs_dirhash(de->name, de->name_len, &h);
+                                printk(":%x.%u ", h.hash,
+                                       ((char *) de - base));
+                        }
+                        space += EXT3_DIR_REC_LEN(de->name_len);
+                        names++;
+                }
+                de = (struct ext3_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
+        }
+        printk("(%i)\n", names);
+        return (struct stats) { names, space, 1 };
+}
+
+struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
+                             struct dx_entry *entries, int levels)
+{
+        unsigned blocksize = dir->i_sb->s_blocksize;
+        unsigned count = dx_get_count (entries), names = 0, space = 0, i;
+        unsigned bcount = 0;
+        struct buffer_head *bh;
+        int err;
+        printk("%i indexed blocks...\n", count);
+        for (i = 0; i < count; i++, entries++)
+        {
+                u32 block = dx_get_block(entries), hash = i? dx_get_hash(entries): 0;
+                u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
+                struct stats stats;
+                printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
+                if (!(bh = ext3_bread (NULL,dir, block, 0,&err))) continue;
+                stats = levels?
+                   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
+                   dx_show_leaf(hinfo, (struct ext3_dir_entry_2 *) bh->b_data, blocksize, 0);
+                names += stats.names;
+                space += stats.space;
+                bcount += stats.bcount;
+                brelse (bh);
+        }
+        if (bcount)
+                printk("%snames %u, fullness %u (%u%%)\n", levels?"":"   ",
+                        names, space/bcount,(space/bcount)*100/blocksize);
+        return (struct stats) { names, space, bcount};
+}
+#endif /* DX_DEBUG */
+
+/*
+ * Probe for a directory leaf block to search.
+ *
+ * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
+ * error in the directory index, and the caller should fall back to
+ * searching the directory normally.  The callers of dx_probe **MUST**
+ * check for this error code, and make sure it never gets reflected
+ * back to userspace.
+ */
+static struct dx_frame *
+dx_probe(struct dentry *dentry, struct inode *dir,
+         struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
+{
+        unsigned count, indirect;
+        struct dx_entry *at, *entries, *p, *q, *m;
+        struct dx_root *root;
+        struct buffer_head *bh;
+        struct dx_frame *frame = frame_in;
+        u32 hash;
+
+        frame->bh = NULL;
+        if (dentry)
+                dir = dentry->d_parent->d_inode;
+        if (!(bh = ext3_bread (NULL,dir, 0, 0, err)))
+                goto fail;
+        root = (struct dx_root *) bh->b_data;
+        if (root->info.hash_version != DX_HASH_TEA &&
+            root->info.hash_version != DX_HASH_HALF_MD4 &&
+            root->info.hash_version != DX_HASH_LEGACY) {
+                ext3_warning(dir->i_sb, __FUNCTION__,
+                             "Unrecognised inode hash code %d",
+                             root->info.hash_version);
+                brelse(bh);
+                *err = ERR_BAD_DX_DIR;
+                goto fail;
+        }
+        hinfo->hash_version = root->info.hash_version;
+        hinfo->seed = EXT3_SB(dir->i_sb)->s_hash_seed;
+        if (dentry)
+                ext3fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo);
+        hash = hinfo->hash;
+
+        if (root->info.unused_flags & 1) {
+                ext3_warning(dir->i_sb, __FUNCTION__,
+                             "Unimplemented inode hash flags: %#06x",
+                             root->info.unused_flags);
+                brelse(bh);
+                *err = ERR_BAD_DX_DIR;
+                goto fail;
+        }
+
+        if ((indirect = root->info.indirect_levels) > 1) {
+                ext3_warning(dir->i_sb, __FUNCTION__,
+                             "Unimplemented inode hash depth: %#06x",
+                             root->info.indirect_levels);
+                brelse(bh);
+                *err = ERR_BAD_DX_DIR;
+                goto fail;
+        }
+
+        entries = (struct dx_entry *) (((char *)&root->info) +
+                                       root->info.info_length);
+        assert(dx_get_limit(entries) == dx_root_limit(dir,
+                                                      root->info.info_length));
+        dxtrace (printk("Look up %x", hash));
+        while (1)
+        {
+                count = dx_get_count(entries);
+                assert (count && count <= dx_get_limit(entries));
+                p = entries + 1;
+                q = entries + count - 1;
+                while (p <= q)
+                {
+                        m = p + (q - p)/2;
+                        dxtrace(printk("."));
+                        if (dx_get_hash(m) > hash)
+                                q = m - 1;
+                        else
+                                p = m + 1;
+                }
+
+                if (0) // linear search cross check
+                {
+                        unsigned n = count - 1;
+                        at = entries;
+                        while (n--)
+                        {
+                                dxtrace(printk(","));
+                                if (dx_get_hash(++at) > hash)
+                                {
+                                        at--;
+                                        break;
+                                }
+                        }
+                        assert (at == p - 1);
+                }
+
+                at = p - 1;
+                dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
+                frame->bh = bh;
+                frame->entries = entries;
+                frame->at = at;
+                if (!indirect--) return frame;
+                if (!(bh = ext3_bread (NULL,dir, dx_get_block(at), 0, err)))
+                        goto fail2;
+                at = entries = ((struct dx_node *) bh->b_data)->entries;
+                assert (dx_get_limit(entries) == dx_node_limit (dir));
+                frame++;
+        }
+fail2:
+        while (frame >= frame_in) {
+                brelse(frame->bh);
+                frame--;
+        }
+fail:
+        return NULL;
+}
+
+static void dx_release (struct dx_frame *frames)
+{
+        if (frames[0].bh == NULL)
+                return;
+
+        if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
+                brelse(frames[1].bh);
+        brelse(frames[0].bh);
+}
+
+/*
+ * This function increments the frame pointer to search the next leaf
+ * block, and reads in the necessary intervening nodes if the search
+ * should be necessary.  Whether or not the search is necessary is
+ * controlled by the hash parameter.  If the hash value is even, then
+ * the search is only continued if the next block starts with that
+ * hash value.  This is used if we are searching for a specific file.
+ *
+ * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
+ *
+ * This function returns 1 if the caller should continue to search,
+ * or 0 if it should not.  If there is an error reading one of the
+ * index blocks, it will a negative error code.
+ *
+ * If start_hash is non-null, it will be filled in with the starting
+ * hash of the next page.
+ */
+static int ext3_htree_next_block(struct inode *dir, __u32 hash,
+                                 struct dx_frame *frame,
+                                 struct dx_frame *frames, 
+                                 __u32 *start_hash)
+{
+        struct dx_frame *p;
+        struct buffer_head *bh;
+        int err, num_frames = 0;
+        __u32 bhash;
+
+        p = frame;
+        /*
+         * Find the next leaf page by incrementing the frame pointer.
+         * If we run out of entries in the interior node, loop around and
+         * increment pointer in the parent node.  When we break out of
+         * this loop, num_frames indicates the number of interior
+         * nodes need to be read.
+         */
+        while (1) {
+                if (++(p->at) < p->entries + dx_get_count(p->entries))
+                        break;
+                if (p == frames)
+                        return 0;
+                num_frames++;
+                p--;
+        }
+
+        /*
+         * If the hash is 1, then continue only if the next page has a
+         * continuation hash of any value.  This is used for readdir
+         * handling.  Otherwise, check to see if the hash matches the
+         * desired contiuation hash.  If it doesn't, return since
+         * there's no point to read in the successive index pages.
+         */
+        bhash = dx_get_hash(p->at);
+        if (start_hash)
+                *start_hash = bhash;
+        if ((hash & 1) == 0) {
+                if ((bhash & ~1) != hash)
+                        return 0;
+        }
+        /*
+         * If the hash is HASH_NB_ALWAYS, we always go to the next
+         * block so no check is necessary
+         */
+        while (num_frames--) {
+                if (!(bh = ext3_bread(NULL, dir, dx_get_block(p->at),
+                                      0, &err)))
+                        return err; /* Failure */
+                p++;
+                brelse (p->bh);
+                p->bh = bh;
+                p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
+        }
+        return 1;
+}
+
+
+/*
+ * p is at least 6 bytes before the end of page
+ */
+static inline struct ext3_dir_entry_2 *ext3_next_entry(struct ext3_dir_entry_2 *p)
+{
+        return (struct ext3_dir_entry_2 *)((char*)p + le16_to_cpu(p->rec_len));
+}
+
+/*
+ * This function fills a red-black tree with information from a
+ * directory block.  It returns the number directory entries loaded
+ * into the tree.  If there is an error it is returned in err.
+ */
+static int htree_dirblock_to_tree(struct file *dir_file,
+                                  struct inode *dir, int block,
+                                  struct dx_hash_info *hinfo,
+                                  __u32 start_hash, __u32 start_minor_hash)
+{
+        struct buffer_head *bh;
+        struct ext3_dir_entry_2 *de, *top;
+        int err, count = 0;
+
+        dxtrace(printk("In htree dirblock_to_tree: block %d\n", block));
+        if (!(bh = ext3_bread (NULL, dir, block, 0, &err)))
+                return err;
+
+        de = (struct ext3_dir_entry_2 *) bh->b_data;
+        top = (struct ext3_dir_entry_2 *) ((char *) de +
+                                           dir->i_sb->s_blocksize -
+                                           EXT3_DIR_REC_LEN(0));
+        for (; de < top; de = ext3_next_entry(de)) {
+                ext3fs_dirhash(de->name, de->name_len, hinfo);
+                if ((hinfo->hash < start_hash) ||
+                    ((hinfo->hash == start_hash) &&
+                     (hinfo->minor_hash < start_minor_hash)))
+                        continue;
+                if (de->inode == 0)
+                        continue;
+                if ((err = ext3_htree_store_dirent(dir_file,
+                                   hinfo->hash, hinfo->minor_hash, de)) != 0) {
+                        brelse(bh);
+                        return err;
+                }
+                count++;
+        }
+        brelse(bh);
+        return count;
+}
+
+
+/*
+ * This function fills a red-black tree with information from a
+ * directory.  We start scanning the directory in hash order, starting
+ * at start_hash and start_minor_hash.
+ *
+ * This function returns the number of entries inserted into the tree,
+ * or a negative error code.
+ */
+int ext3_htree_fill_tree(struct file *dir_file, __u32 start_hash,
+                         __u32 start_minor_hash, __u32 *next_hash)
+{
+        struct dx_hash_info hinfo;
+        struct ext3_dir_entry_2 *de;
+        struct dx_frame frames[2], *frame;
+        struct inode *dir;
+        int block, err;
+        int count = 0;
+        int ret;
+        __u32 hashval;
+
+        dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
+                       start_minor_hash));
+        dir = dir_file->f_dentry->d_inode;
+        if (!(EXT3_I(dir)->i_flags & EXT3_INDEX_FL)) {
+                hinfo.hash_version = EXT3_SB(dir->i_sb)->s_def_hash_version;
+                hinfo.seed = EXT3_SB(dir->i_sb)->s_hash_seed;
+                count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
+                                               start_hash, start_minor_hash);
+                *next_hash = ~0;
+                return count;
+        }
+        hinfo.hash = start_hash;
+        hinfo.minor_hash = 0;
+        frame = dx_probe(NULL, dir_file->f_dentry->d_inode, &hinfo, frames, &err);
+        if (!frame)
+                return err;
+
+        /* Add '.' and '..' from the htree header */
+        if (!start_hash && !start_minor_hash) {
+                de = (struct ext3_dir_entry_2 *) frames[0].bh->b_data;
+                if ((err = ext3_htree_store_dirent(dir_file, 0, 0, de)) != 0)
+                        goto errout;
+                count++;
+        }
+        if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
+                de = (struct ext3_dir_entry_2 *) frames[0].bh->b_data;
+                de = ext3_next_entry(de);
+                if ((err = ext3_htree_store_dirent(dir_file, 2, 0, de)) != 0)
+                        goto errout;
+                count++;
+        }
+
+        while (1) {
+                block = dx_get_block(frame->at);
+                ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
+                                             start_hash, start_minor_hash);
+                if (ret < 0) {
+                        err = ret;
+                        goto errout;
+                }
+                count += ret;
+                hashval = ~0;
+                ret = ext3_htree_next_block(dir, HASH_NB_ALWAYS, 
+                                            frame, frames, &hashval);
+                *next_hash = hashval;
+                if (ret < 0) {
+                        err = ret;
+                        goto errout;
+                }
+                /*
+                 * Stop if:  (a) there are no more entries, or
+                 * (b) we have inserted at least one entry and the
+                 * next hash value is not a continuation
+                 */
+                if ((ret == 0) ||
+                    (count && ((hashval & 1) == 0)))
+                        break;
+        }
+        dx_release(frames);
+        dxtrace(printk("Fill tree: returned %d entries, next hash: %x\n", 
+                       count, *next_hash));
+        return count;
+errout:
+        dx_release(frames);
+        return (err);
+}
+
+
+/*
+ * Directory block splitting, compacting
+ */
+
+static int dx_make_map (struct ext3_dir_entry_2 *de, int size,
+                        struct dx_hash_info *hinfo, struct dx_map_entry *map_tail)
+{
+        int count = 0;
+        char *base = (char *) de;
+        struct dx_hash_info h = *hinfo;
+
+        while ((char *) de < base + size)
+        {
+                if (de->name_len && de->inode) {
+                        ext3fs_dirhash(de->name, de->name_len, &h);
+                        map_tail--;
+                        map_tail->hash = h.hash;
+                        map_tail->offs = (u32) ((char *) de - base);
+                        count++;
+                        cond_resched();
+                }
+                /* XXX: do we need to check rec_len == 0 case? -Chris */
+                de = (struct ext3_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
+        }
+        return count;
+}
+
+static void dx_sort_map (struct dx_map_entry *map, unsigned count)
+{
+        struct dx_map_entry *p, *q, *top = map + count - 1;
+        int more;
+        /* Combsort until bubble sort doesn't suck */
+        while (count > 2)
+        {
+                count = count*10/13;
+                if (count - 9 < 2) /* 9, 10 -> 11 */
+                        count = 11;
+                for (p = top, q = p - count; q >= map; p--, q--)
+                        if (p->hash < q->hash)
+                                swap(*p, *q);
+        }
+        /* Garden variety bubble sort */
+        do {
+                more = 0;
+                q = top;
+                while (q-- > map)
+                {
+                        if (q[1].hash >= q[0].hash)
+                                continue;
+                        swap(*(q+1), *q);
+                        more = 1;
+                }
+        } while(more);
+}
+
+static void dx_insert_block(struct dx_frame *frame, u32 hash, u32 block)
+{
+        struct dx_entry *entries = frame->entries;
+        struct dx_entry *old = frame->at, *new = old + 1;
+        int count = dx_get_count(entries);
+
+        assert(count < dx_get_limit(entries));
+        assert(old < entries + count);
+        memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
+        dx_set_hash(new, hash);
+        dx_set_block(new, block);
+        dx_set_count(entries, count + 1);
+}
+#endif
+
+
+static void ext3_update_dx_flag(struct inode *inode)
+{
+        if (!EXT3_HAS_COMPAT_FEATURE(inode->i_sb,
+                                     EXT3_FEATURE_COMPAT_DIR_INDEX))
+                EXT3_I(inode)->i_flags &= ~EXT3_INDEX_FL;
+}
+
+/*
+ * NOTE! unlike strncmp, ext3_match returns 1 for success, 0 for failure.
+ *
+ * `len <= EXT3_NAME_LEN' is guaranteed by caller.
+ * `de != NULL' is guaranteed by caller.
+ */
+static inline int ext3_match (int len, const char * const name,
+                              struct ext3_dir_entry_2 * de)
+{
+        if (len != de->name_len)
+                return 0;
+        if (!de->inode)
+                return 0;
+        return !memcmp(name, de->name, len);
+}
+
+/*
+ * Returns 0 if not found, -1 on failure, and 1 on success
+ */
+static inline int search_dirblock(struct buffer_head * bh,
+                                  struct inode *dir,
+                                  struct dentry *dentry,
+                                  unsigned long offset,
+                                  struct ext3_dir_entry_2 ** res_dir)
+{
+        struct ext3_dir_entry_2 * de;
+        char * dlimit;
+        int de_len;
+        const char *name = dentry->d_name.name;
+        int namelen = dentry->d_name.len;
+
+        de = (struct ext3_dir_entry_2 *) bh->b_data;
+        dlimit = bh->b_data + dir->i_sb->s_blocksize;
+        while ((char *) de < dlimit) {
+                /* this code is executed quadratically often */
+                /* do minimal checking `by hand' */
+
+                if ((char *) de + namelen <= dlimit &&
+                    ext3_match (namelen, name, de)) {
+                        /* found a match - just to be sure, do a full check */
+                        if (!ext3_check_dir_entry("ext3_find_entry",
+                                                  dir, de, bh, offset))
+                                return -1;
+                        *res_dir = de;
+                        return 1;
+                }
+                /* prevent looping on a bad block */
+                de_len = le16_to_cpu(de->rec_len);
+                if (de_len <= 0)
+                        return -1;
+                offset += de_len;
+                de = (struct ext3_dir_entry_2 *) ((char *) de + de_len);
+        }
+        return 0;
+}
+
+
+/*
+ *      ext3_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the cache buffer in which the entry was found, and the entry
+ * itself (as a parameter - res_dir). It does NOT read the inode of the
+ * entry - you'll have to do that yourself if you want to.
+ *
+ * The returned buffer_head has ->b_count elevated.  The caller is expected
+ * to brelse() it when appropriate.
+ */
+static struct buffer_head * ext3_find_entry (struct dentry *dentry,
+                                        struct ext3_dir_entry_2 ** res_dir)
+{
+        struct super_block * sb;
+        struct buffer_head * bh_use[NAMEI_RA_SIZE];
+        struct buffer_head * bh, *ret = NULL;
+        unsigned long start, block, b;
+        int ra_max = 0;         /* Number of bh's in the readahead
+                                   buffer, bh_use[] */
+        int ra_ptr = 0;         /* Current index into readahead
+                                   buffer */
+        int num = 0;
+        int nblocks, i, err;
+        struct inode *dir = dentry->d_parent->d_inode;
+        int namelen;
+        const u8 *name;
+        unsigned blocksize;
+
+        *res_dir = NULL;
+        sb = dir->i_sb;
+        blocksize = sb->s_blocksize;
+        namelen = dentry->d_name.len;
+        name = dentry->d_name.name;
+        if (namelen > EXT3_NAME_LEN)
+                return NULL;
+#ifdef CONFIG_EXT3_INDEX
+        if (is_dx(dir)) {
+                bh = ext3_dx_find_entry(dentry, res_dir, &err);
+                /*
+                 * On success, or if the error was file not found,
+                 * return.  Otherwise, fall back to doing a search the
+                 * old fashioned way.
+                 */
+                if (bh || (err != ERR_BAD_DX_DIR))
+                        return bh;
+                dxtrace(printk("ext3_find_entry: dx failed, falling back\n"));
+        }
+#endif
+        nblocks = dir->i_size >> EXT3_BLOCK_SIZE_BITS(sb);
+        start = EXT3_I(dir)->i_dir_start_lookup;
+        if (start >= nblocks)
+                start = 0;
+        block = start;
+restart:
+        do {
+                /*
+                 * We deal with the read-ahead logic here.
+                 */
+                if (ra_ptr >= ra_max) {
+                        /* Refill the readahead buffer */
+                        ra_ptr = 0;
+                        b = block;
+                        for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
+                                /*
+                                 * Terminate if we reach the end of the
+                                 * directory and must wrap, or if our
+                                 * search has finished at this block.
+                                 */
+                                if (b >= nblocks || (num && block == start)) {
+                                        bh_use[ra_max] = NULL;
+                                        break;
+                                }
+                                num++;
+                                bh = ext3_getblk(NULL, dir, b++, 0, &err);
+                                bh_use[ra_max] = bh;
+                                if (bh)
+                                        ll_rw_block(READ, 1, &bh);
+                        }
+                }
+                if ((bh = bh_use[ra_ptr++]) == NULL)
+                        goto next;
+                wait_on_buffer(bh);
+                if (!buffer_uptodate(bh)) {
+                        /* read error, skip block & hope for the best */
+                        ext3_error(sb, __FUNCTION__, "reading directory #%lu "
+                                   "offset %lu", dir->i_ino, block);
+                        brelse(bh);
+                        goto next;
+                }
+                i = search_dirblock(bh, dir, dentry,
+                            block << EXT3_BLOCK_SIZE_BITS(sb), res_dir);
+                if (i == 1) {
+                        EXT3_I(dir)->i_dir_start_lookup = block;
+                        ret = bh;
+                        goto cleanup_and_exit;
+                } else {
+                        brelse(bh);
+                        if (i < 0)
+                                goto cleanup_and_exit;
+                }
+        next:
+                if (++block >= nblocks)
+                        block = 0;
+        } while (block != start);
+
+        /*
+         * If the directory has grown while we were searching, then
+         * search the last part of the directory before giving up.
+         */
+        block = nblocks;
+        nblocks = dir->i_size >> EXT3_BLOCK_SIZE_BITS(sb);
+        if (block < nblocks) {
+                start = 0;
+                goto restart;
+        }
+
+cleanup_and_exit:
+        /* Clean up the read-ahead blocks */
+        for (; ra_ptr < ra_max; ra_ptr++)
+                brelse (bh_use[ra_ptr]);
+        return ret;
+}
+
+#ifdef CONFIG_EXT3_INDEX
+static struct buffer_head * ext3_dx_find_entry(struct dentry *dentry,
+                       struct ext3_dir_entry_2 **res_dir, int *err)
+{
+        struct super_block * sb;
+        struct dx_hash_info     hinfo;
+        u32 hash;
+        struct dx_frame frames[2], *frame;
+        struct ext3_dir_entry_2 *de, *top;
+        struct buffer_head *bh;
+        unsigned long block;
+        int retval;
+        int namelen = dentry->d_name.len;
+        const u8 *name = dentry->d_name.name;
+        struct inode *dir = dentry->d_parent->d_inode;
+
+        sb = dir->i_sb;
+        if (!(frame = dx_probe(dentry, NULL, &hinfo, frames, err)))
+                return NULL;
+        hash = hinfo.hash;
+        do {
+                block = dx_get_block(frame->at);
+                if (!(bh = ext3_bread (NULL,dir, block, 0, err)))
+                        goto errout;
+                de = (struct ext3_dir_entry_2 *) bh->b_data;
+                top = (struct ext3_dir_entry_2 *) ((char *) de + sb->s_blocksize -
+                                       EXT3_DIR_REC_LEN(0));
+                for (; de < top; de = ext3_next_entry(de))
+                if (ext3_match (namelen, name, de)) {
+                        if (!ext3_check_dir_entry("ext3_find_entry",
+                                                  dir, de, bh,
+                                  (block<<EXT3_BLOCK_SIZE_BITS(sb))
+                                          +((char *)de - bh->b_data))) {
+                                brelse (bh);
+                                goto errout;
+                        }
+                        *res_dir = de;
+                        dx_release (frames);
+                        return bh;
+                }
+                brelse (bh);
+                /* Check to see if we should continue to search */
+                retval = ext3_htree_next_block(dir, hash, frame,
+                                               frames, NULL);
+                if (retval < 0) {
+                        ext3_warning(sb, __FUNCTION__,
+                             "error reading index page in directory #%lu",
+                             dir->i_ino);
+                        *err = retval;
+                        goto errout;
+                }
+        } while (retval == 1);
+
+        *err = -ENOENT;
+errout:
+        dxtrace(printk("%s not found\n", name));
+        dx_release (frames);
+        return NULL;
+}
+#endif
+
+static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+{
+        struct inode * inode;
+        struct ext3_dir_entry_2 * de;
+        struct buffer_head * bh;
+
+        if (dentry->d_name.len > EXT3_NAME_LEN)
+                return ERR_PTR(-ENAMETOOLONG);
+
+        bh = ext3_find_entry(dentry, &de);
+        inode = NULL;
+        if (bh) {
+                unsigned long ino = le32_to_cpu(de->inode);
+                brelse (bh);
+                inode = iget(dir->i_sb, ino);
+
+                if (!inode)
+                        return ERR_PTR(-EACCES);
+        }
+        if (inode)
+                return d_splice_alias(inode, dentry);
+        d_add(dentry, inode);
+        return NULL;
+}
+
+
+struct dentry *ext3_get_parent(struct dentry *child)
+{
+        unsigned long ino;
+        struct dentry *parent;
+        struct inode *inode;
+        struct dentry dotdot;
+        struct ext3_dir_entry_2 * de;
+        struct buffer_head *bh;
+
+        dotdot.d_name.name = "..";
+        dotdot.d_name.len = 2;
+        dotdot.d_parent = child; /* confusing, isn't it! */
+
+        bh = ext3_find_entry(&dotdot, &de);
+        inode = NULL;
+        if (!bh)
+                return ERR_PTR(-ENOENT);
+        ino = le32_to_cpu(de->inode);
+        brelse(bh);
+        inode = iget(child->d_inode->i_sb, ino);
+
+        if (!inode)
+                return ERR_PTR(-EACCES);
+
+        parent = d_alloc_anon(inode);
+        if (!parent) {
+                iput(inode);
+                parent = ERR_PTR(-ENOMEM);
+        }
+        return parent;
+} 
+
+#define S_SHIFT 12
+static unsigned char ext3_type_by_mode[S_IFMT >> S_SHIFT] = {
+        [S_IFREG >> S_SHIFT]    = EXT3_FT_REG_FILE,
+        [S_IFDIR >> S_SHIFT]    = EXT3_FT_DIR,
+        [S_IFCHR >> S_SHIFT]    = EXT3_FT_CHRDEV,
+        [S_IFBLK >> S_SHIFT]    = EXT3_FT_BLKDEV,
+        [S_IFIFO >> S_SHIFT]    = EXT3_FT_FIFO,
+        [S_IFSOCK >> S_SHIFT]   = EXT3_FT_SOCK,
+        [S_IFLNK >> S_SHIFT]    = EXT3_FT_SYMLINK,
+};
+
+static inline void ext3_set_de_type(struct super_block *sb,
+                                struct ext3_dir_entry_2 *de,
+                                umode_t mode) {
+        if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_FILETYPE))
+                de->file_type = ext3_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
+}
+
+#ifdef CONFIG_EXT3_INDEX
+static struct ext3_dir_entry_2 *
+dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
+{
+        unsigned rec_len = 0;
+
+        while (count--) {
+                struct ext3_dir_entry_2 *de = (struct ext3_dir_entry_2 *) (from + map->offs);
+                rec_len = EXT3_DIR_REC_LEN(de->name_len);
+                memcpy (to, de, rec_len);
+                ((struct ext3_dir_entry_2 *) to)->rec_len =
+                                cpu_to_le16(rec_len);
+                de->inode = 0;
+                map++;
+                to += rec_len;
+        }
+        return (struct ext3_dir_entry_2 *) (to - rec_len);
+}
+
+static struct ext3_dir_entry_2* dx_pack_dirents(char *base, int size)
+{
+        struct ext3_dir_entry_2 *next, *to, *prev, *de = (struct ext3_dir_entry_2 *) base;
+        unsigned rec_len = 0;
+
+        prev = to = de;
+        while ((char*)de < base + size) {
+                next = (struct ext3_dir_entry_2 *) ((char *) de +
+                                                    le16_to_cpu(de->rec_len));
+                if (de->inode && de->name_len) {
+                        rec_len = EXT3_DIR_REC_LEN(de->name_len);
+                        if (de > to)
+                                memmove(to, de, rec_len);
+                        to->rec_len = cpu_to_le16(rec_len);
+                        prev = to;
+                        to = (struct ext3_dir_entry_2 *) (((char *) to) + rec_len);
+                }
+                de = next;
+        }
+        return prev;
+}
+
+static struct ext3_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
+                        struct buffer_head **bh,struct dx_frame *frame,
+                        struct dx_hash_info *hinfo, int *error)
+{
+        unsigned blocksize = dir->i_sb->s_blocksize;
+        unsigned count, continued;
+        struct buffer_head *bh2;
+        u32 newblock;
+        u32 hash2;
+        struct dx_map_entry *map;
+        char *data1 = (*bh)->b_data, *data2;
+        unsigned split;
+        struct ext3_dir_entry_2 *de = NULL, *de2;
+        int     err;
+
+        bh2 = ext3_append (handle, dir, &newblock, error);
+        if (!(bh2)) {
+                brelse(*bh);
+                *bh = NULL;
+                goto errout;
+        }
+
+        BUFFER_TRACE(*bh, "get_write_access");
+        err = ext3_journal_get_write_access(handle, *bh);
+        if (err) {
+        journal_error:
+                brelse(*bh);
+                brelse(bh2);
+                *bh = NULL;
+                ext3_std_error(dir->i_sb, err);
+                goto errout;
+        }
+        BUFFER_TRACE(frame->bh, "get_write_access");
+        err = ext3_journal_get_write_access(handle, frame->bh);
+        if (err)
+                goto journal_error;
+
+        data2 = bh2->b_data;
+
+        /* create map in the end of data2 block */
+        map = (struct dx_map_entry *) (data2 + blocksize);
+        count = dx_make_map ((struct ext3_dir_entry_2 *) data1,
+                             blocksize, hinfo, map);
+        map -= count;
+        split = count/2; // need to adjust to actual middle
+        dx_sort_map (map, count);
+        hash2 = map[split].hash;
+        continued = hash2 == map[split - 1].hash;
+        dxtrace(printk("Split block %i at %x, %i/%i\n",
+                dx_get_block(frame->at), hash2, split, count-split));
+
+        /* Fancy dance to stay within two buffers */
+        de2 = dx_move_dirents(data1, data2, map + split, count - split);
+        de = dx_pack_dirents(data1,blocksize);
+        de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
+        de2->rec_len = cpu_to_le16(data2 + blocksize - (char *) de2);
+        dxtrace(dx_show_leaf (hinfo, (struct ext3_dir_entry_2 *) data1, blocksize, 1));
+        dxtrace(dx_show_leaf (hinfo, (struct ext3_dir_entry_2 *) data2, blocksize, 1));
+
+        /* Which block gets the new entry? */
+        if (hinfo->hash >= hash2)
+        {
+                swap(*bh, bh2);
+                de = de2;
+        }
+        dx_insert_block (frame, hash2 + continued, newblock);
+        err = ext3_journal_dirty_metadata (handle, bh2);
+        if (err)
+                goto journal_error;
+        err = ext3_journal_dirty_metadata (handle, frame->bh);
+        if (err)
+                goto journal_error;
+        brelse (bh2);
+        dxtrace(dx_show_index ("frame", frame->entries));
+errout:
+        return de;
+}
+#endif
+
+
+/*
+ * Add a new entry into a directory (leaf) block.  If de is non-NULL,
+ * it points to a directory entry which is guaranteed to be large
+ * enough for new directory entry.  If de is NULL, then
+ * add_dirent_to_buf will attempt search the directory block for
+ * space.  It will return -ENOSPC if no space is available, and -EIO
+ * and -EEXIST if directory entry already exists.
+ * 
+ * NOTE!  bh is NOT released in the case where ENOSPC is returned.  In
+ * all other cases bh is released.
+ */
+static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
+                             struct inode *inode, struct ext3_dir_entry_2 *de,
+                             struct buffer_head * bh)
+{
+        struct inode    *dir = dentry->d_parent->d_inode;
+        const char      *name = dentry->d_name.name;
+        int             namelen = dentry->d_name.len;
+        unsigned long   offset = 0;
+        unsigned short  reclen;
+        int             nlen, rlen, err;
+        char            *top;
+
+        reclen = EXT3_DIR_REC_LEN(namelen);
+        if (!de) {
+                de = (struct ext3_dir_entry_2 *)bh->b_data;
+                top = bh->b_data + dir->i_sb->s_blocksize - reclen;
+                while ((char *) de <= top) {
+                        if (!ext3_check_dir_entry("ext3_add_entry", dir, de,
+                                                  bh, offset)) {
+                                brelse (bh);
+                                return -EIO;
+                        }
+                        if (ext3_match (namelen, name, de)) {
+                                brelse (bh);
+                                return -EEXIST;
+                        }
+                        nlen = EXT3_DIR_REC_LEN(de->name_len);
+                        rlen = le16_to_cpu(de->rec_len);
+                        if ((de->inode? rlen - nlen: rlen) >= reclen)
+                                break;
+                        de = (struct ext3_dir_entry_2 *)((char *)de + rlen);
+                        offset += rlen;
+                }
+                if ((char *) de > top)
+                        return -ENOSPC;
+        }
+        BUFFER_TRACE(bh, "get_write_access");
+        err = ext3_journal_get_write_access(handle, bh);
+        if (err) {
+                ext3_std_error(dir->i_sb, err);
+                brelse(bh);
+                return err;
+        }
+
+        /* By now the buffer is marked for journaling */
+        nlen = EXT3_DIR_REC_LEN(de->name_len);
+        rlen = le16_to_cpu(de->rec_len);
+        if (de->inode) {
+                struct ext3_dir_entry_2 *de1 = (struct ext3_dir_entry_2 *)((char *)de + nlen);
+                de1->rec_len = cpu_to_le16(rlen - nlen);
+                de->rec_len = cpu_to_le16(nlen);
+                de = de1;
+        }
+        de->file_type = EXT3_FT_UNKNOWN;
+        if (inode) {
+                de->inode = cpu_to_le32(inode->i_ino);
+                ext3_set_de_type(dir->i_sb, de, inode->i_mode);
+        } else
+                de->inode = 0;
+        de->name_len = namelen;
+        memcpy (de->name, name, namelen);
+        /*
+         * XXX shouldn't update any times until successful
+         * completion of syscall, but too many callers depend
+         * on this.
+         *
+         * XXX similarly, too many callers depend on
+         * ext3_new_inode() setting the times, but error
+         * recovery deletes the inode, so the worst that can
+         * happen is that the times are slightly out of date
+         * and/or different from the directory change time.
+         */
+        dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+        ext3_update_dx_flag(dir);
+        dir->i_version++;
+        ext3_mark_inode_dirty(handle, dir);
+        BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+        err = ext3_journal_dirty_metadata(handle, bh);
+        if (err)
+                ext3_std_error(dir->i_sb, err);
+        brelse(bh);
+        return 0;
+}
+
+#ifdef CONFIG_EXT3_INDEX
+/*
+ * This converts a one block unindexed directory to a 3 block indexed
+ * directory, and adds the dentry to the indexed directory.
+ */
+static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
+                            struct inode *inode, struct buffer_head *bh)
+{
+        struct inode    *dir = dentry->d_parent->d_inode;
+        const char      *name = dentry->d_name.name;
+        int             namelen = dentry->d_name.len;
+        struct buffer_head *bh2;
+        struct dx_root  *root;
+        struct dx_frame frames[2], *frame;
+        struct dx_entry *entries;
+        struct ext3_dir_entry_2 *de, *de2;
+        char            *data1, *top;
+        unsigned        len;
+        int             retval;
+        unsigned        blocksize;
+        struct dx_hash_info hinfo;
+        u32             block;
+        struct fake_dirent *fde;
+
+        blocksize =  dir->i_sb->s_blocksize;
+        dxtrace(printk("Creating index\n"));
+        retval = ext3_journal_get_write_access(handle, bh);
+        if (retval) {
+                ext3_std_error(dir->i_sb, retval);
+                brelse(bh);
+                return retval;
+        }
+        root = (struct dx_root *) bh->b_data;
+
+        bh2 = ext3_append (handle, dir, &block, &retval);
+        if (!(bh2)) {
+                brelse(bh);
+                return retval;
+        }
+        EXT3_I(dir)->i_flags |= EXT3_INDEX_FL;
+        data1 = bh2->b_data;
+
+        /* The 0th block becomes the root, move the dirents out */
+        fde = &root->dotdot;
+        de = (struct ext3_dir_entry_2 *)((char *)fde + le16_to_cpu(fde->rec_len));
+        len = ((char *) root) + blocksize - (char *) de;
+        memcpy (data1, de, len);
+        de = (struct ext3_dir_entry_2 *) data1;
+        top = data1 + len;
+        while ((char *)(de2=(void*)de+le16_to_cpu(de->rec_len)) < top)
+                de = de2;
+        de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
+        /* Initialize the root; the dot dirents already exist */
+        de = (struct ext3_dir_entry_2 *) (&root->dotdot);
+        de->rec_len = cpu_to_le16(blocksize - EXT3_DIR_REC_LEN(2));
+        memset (&root->info, 0, sizeof(root->info));
+        root->info.info_length = sizeof(root->info);
+        root->info.hash_version = EXT3_SB(dir->i_sb)->s_def_hash_version;
+        entries = root->entries;
+        dx_set_block (entries, 1);
+        dx_set_count (entries, 1);
+        dx_set_limit (entries, dx_root_limit(dir, sizeof(root->info)));
+
+        /* Initialize as for dx_probe */
+        hinfo.hash_version = root->info.hash_version;
+        hinfo.seed = EXT3_SB(dir->i_sb)->s_hash_seed;
+        ext3fs_dirhash(name, namelen, &hinfo);
+        frame = frames;
+        frame->entries = entries;
+        frame->at = entries;
+        frame->bh = bh;
+        bh = bh2;
+        de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
+        dx_release (frames);
+        if (!(de))
+                return retval;
+
+        return add_dirent_to_buf(handle, dentry, inode, de, bh);
+}
+#endif
+
+/*
+ *      ext3_add_entry()
+ *
+ * adds a file entry to the specified directory, using the same
+ * semantics as ext3_find_entry(). It returns NULL if it failed.
+ *
+ * NOTE!! The inode part of 'de' is left at 0 - which means you
+ * may not sleep between calling this and putting something into
+ * the entry, as someone else might have used it while you slept.
+ */
+static int ext3_add_entry (handle_t *handle, struct dentry *dentry,
+        struct inode *inode)
+{
+        struct inode *dir = dentry->d_parent->d_inode;
+        unsigned long offset;
+        struct buffer_head * bh;
+        struct ext3_dir_entry_2 *de;
+        struct super_block * sb;
+        int     retval;
+#ifdef CONFIG_EXT3_INDEX
+        int     dx_fallback=0;
+#endif
+        unsigned blocksize;
+        unsigned nlen, rlen;
+        u32 block, blocks;
+
+        sb = dir->i_sb;
+        blocksize = sb->s_blocksize;
+        if (!dentry->d_name.len)
+                return -EINVAL;
+#ifdef CONFIG_EXT3_INDEX
+        if (is_dx(dir)) {
+                retval = ext3_dx_add_entry(handle, dentry, inode);
+                if (!retval || (retval != ERR_BAD_DX_DIR))
+                        return retval;
+                EXT3_I(dir)->i_flags &= ~EXT3_INDEX_FL;
+                dx_fallback++;
+                ext3_mark_inode_dirty(handle, dir);
+        }
+#endif
+        blocks = dir->i_size >> sb->s_blocksize_bits;
+        for (block = 0, offset = 0; block < blocks; block++) {
+                bh = ext3_bread(handle, dir, block, 0, &retval);
+                if(!bh)
+                        return retval;
+                retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
+                if (retval != -ENOSPC)
+                        return retval;
+
+#ifdef CONFIG_EXT3_INDEX
+                if (blocks == 1 && !dx_fallback &&
+                    EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_DIR_INDEX))
+                        return make_indexed_dir(handle, dentry, inode, bh);
+#endif
+                brelse(bh);
+        }
+        bh = ext3_append(handle, dir, &block, &retval);
+        if (!bh)
+                return retval;
+        de = (struct ext3_dir_entry_2 *) bh->b_data;
+        de->inode = 0;
+        de->rec_len = cpu_to_le16(rlen = blocksize);
+        nlen = 0;
+        return add_dirent_to_buf(handle, dentry, inode, de, bh);
+}
+
+#ifdef CONFIG_EXT3_INDEX
+/*
+ * Returns 0 for success, or a negative error value
+ */
+static int ext3_dx_add_entry(handle_t *handle, struct dentry *dentry,
+                             struct inode *inode)
+{
+        struct dx_frame frames[2], *frame;
+        struct dx_entry *entries, *at;
+        struct dx_hash_info hinfo;
+        struct buffer_head * bh;
+        struct inode *dir = dentry->d_parent->d_inode;
+        struct super_block * sb = dir->i_sb;
+        struct ext3_dir_entry_2 *de;
+        int err;
+
+        frame = dx_probe(dentry, NULL, &hinfo, frames, &err);
+        if (!frame)
+                return err;
+        entries = frame->entries;
+        at = frame->at;
+
+        if (!(bh = ext3_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
+                goto cleanup;
+
+        BUFFER_TRACE(bh, "get_write_access");
+        err = ext3_journal_get_write_access(handle, bh);
+        if (err)
+                goto journal_error;
+
+        err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
+        if (err != -ENOSPC) {
+                bh = NULL;
+                goto cleanup;
+        }
+
+        /* Block full, should compress but for now just split */
+        dxtrace(printk("using %u of %u node entries\n",
+                       dx_get_count(entries), dx_get_limit(entries)));
+        /* Need to split index? */
+        if (dx_get_count(entries) == dx_get_limit(entries)) {
+                u32 newblock;
+                unsigned icount = dx_get_count(entries);
+                int levels = frame - frames;
+                struct dx_entry *entries2;
+                struct dx_node *node2;
+                struct buffer_head *bh2;
+
+                if (levels && (dx_get_count(frames->entries) ==
+                               dx_get_limit(frames->entries))) {
+                        ext3_warning(sb, __FUNCTION__,
+                                     "Directory index full!\n");
+                        err = -ENOSPC;
+                        goto cleanup;
+                }
+                bh2 = ext3_append (handle, dir, &newblock, &err);
+                if (!(bh2))
+                        goto cleanup;
+                node2 = (struct dx_node *)(bh2->b_data);
+                entries2 = node2->entries;
+                node2->fake.rec_len = cpu_to_le16(sb->s_blocksize);
+                node2->fake.inode = 0;
+                BUFFER_TRACE(frame->bh, "get_write_access");
+                err = ext3_journal_get_write_access(handle, frame->bh);
+                if (err)
+                        goto journal_error;
+                if (levels) {
+                        unsigned icount1 = icount/2, icount2 = icount - icount1;
+                        unsigned hash2 = dx_get_hash(entries + icount1);
+                        dxtrace(printk("Split index %i/%i\n", icount1, icount2));
+
+                        BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
+                        err = ext3_journal_get_write_access(handle,
+                                                             frames[0].bh);
+                        if (err)
+                                goto journal_error;
+
+                        memcpy ((char *) entries2, (char *) (entries + icount1),
+                                icount2 * sizeof(struct dx_entry));
+                        dx_set_count (entries, icount1);
+                        dx_set_count (entries2, icount2);
+                        dx_set_limit (entries2, dx_node_limit(dir));
+
+                        /* Which index block gets the new entry? */
+                        if (at - entries >= icount1) {
+                                frame->at = at = at - entries - icount1 + entries2;
+                                frame->entries = entries = entries2;
+                                swap(frame->bh, bh2);
+                        }
+                        dx_insert_block (frames + 0, hash2, newblock);
+                        dxtrace(dx_show_index ("node", frames[1].entries));
+                        dxtrace(dx_show_index ("node",
+                               ((struct dx_node *) bh2->b_data)->entries));
+                        err = ext3_journal_dirty_metadata(handle, bh2);
+                        if (err)
+                                goto journal_error;
+                        brelse (bh2);
+                } else {
+                        dxtrace(printk("Creating second level index...\n"));
+                        memcpy((char *) entries2, (char *) entries,
+                               icount * sizeof(struct dx_entry));
+                        dx_set_limit(entries2, dx_node_limit(dir));
+
+                        /* Set up root */
+                        dx_set_count(entries, 1);
+                        dx_set_block(entries + 0, newblock);
+                        ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
+
+                        /* Add new access path frame */
+                        frame = frames + 1;
+                        frame->at = at = at - entries + entries2;
+                        frame->entries = entries = entries2;
+                        frame->bh = bh2;
+                        err = ext3_journal_get_write_access(handle,
+                                                             frame->bh);
+                        if (err)
+                                goto journal_error;
+                }
+                ext3_journal_dirty_metadata(handle, frames[0].bh);
+        }
+        de = do_split(handle, dir, &bh, frame, &hinfo, &err);
+        if (!de)
+                goto cleanup;
+        err = add_dirent_to_buf(handle, dentry, inode, de, bh);
+        bh = NULL;
+        goto cleanup;
+
+journal_error:
+        ext3_std_error(dir->i_sb, err);
+cleanup:
+        if (bh)
+                brelse(bh);
+        dx_release(frames);
+        return err;
+}
+#endif
+
+/*
+ * ext3_delete_entry deletes a directory entry by merging it with the
+ * previous entry
+ */
+static int ext3_delete_entry (handle_t *handle, 
+                              struct inode * dir,
+                              struct ext3_dir_entry_2 * de_del,
+                              struct buffer_head * bh)
+{
+        struct ext3_dir_entry_2 * de, * pde;
+        int i;
+
+        i = 0;
+        pde = NULL;
+        de = (struct ext3_dir_entry_2 *) bh->b_data;
+        while (i < bh->b_size) {
+                if (!ext3_check_dir_entry("ext3_delete_entry", dir, de, bh, i))
+                        return -EIO;
+                if (de == de_del)  {
+                        BUFFER_TRACE(bh, "get_write_access");
+                        ext3_journal_get_write_access(handle, bh);
+                        if (pde)
+                                pde->rec_len =
+                                        cpu_to_le16(le16_to_cpu(pde->rec_len) +
+                                                    le16_to_cpu(de->rec_len));
+                        else
+                                de->inode = 0;
+                        dir->i_version++;
+                        BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
+                        ext3_journal_dirty_metadata(handle, bh);
+                        return 0;
+                }
+                i += le16_to_cpu(de->rec_len);
+                pde = de;
+                de = (struct ext3_dir_entry_2 *)
+                        ((char *) de + le16_to_cpu(de->rec_len));
+        }
+        return -ENOENT;
+}
+
+/*
+ * ext3_mark_inode_dirty is somewhat expensive, so unlike ext2 we
+ * do not perform it in these functions.  We perform it at the call site,
+ * if it is needed.
+ */
+static inline void ext3_inc_count(handle_t *handle, struct inode *inode)
+{
+        inode->i_nlink++;
+}
+
+static inline void ext3_dec_count(handle_t *handle, struct inode *inode)
+{
+        inode->i_nlink--;
+}
+
+static int ext3_add_nondir(handle_t *handle,
+                struct dentry *dentry, struct inode *inode)
+{
+        int err = ext3_add_entry(handle, dentry, inode);
+        if (!err) {
+                ext3_mark_inode_dirty(handle, inode);
+                d_instantiate(dentry, inode);
+                return 0;
+        }
+        ext3_dec_count(handle, inode);
+        iput(inode);
+        return err;
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate(). 
+ */
+static int ext3_create (struct inode * dir, struct dentry * dentry, int mode,
+                struct nameidata *nd)
+{
+        handle_t *handle; 
+        struct inode * inode;
+        int err, retries = 0;
+
+retry:
+        handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS +
+                                        EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+                                        2*EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        inode = ext3_new_inode (handle, dir, mode);
+        err = PTR_ERR(inode);
+        if (!IS_ERR(inode)) {
+                inode->i_op = &ext3_file_inode_operations;
+                inode->i_fop = &ext3_file_operations;
+                ext3_set_aops(inode);
+                err = ext3_add_nondir(handle, dentry, inode);
+        }
+        ext3_journal_stop(handle);
+        if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
+                goto retry;
+        return err;
+}
+
+static int ext3_mknod (struct inode * dir, struct dentry *dentry,
+                        int mode, dev_t rdev)
+{
+        handle_t *handle;
+        struct inode *inode;
+        int err, retries = 0;
+
+        if (!new_valid_dev(rdev))
+                return -EINVAL;
+
+retry:
+        handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS +
+                                        EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+                                        2*EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        inode = ext3_new_inode (handle, dir, mode);
+        err = PTR_ERR(inode);
+        if (!IS_ERR(inode)) {
+                init_special_inode(inode, inode->i_mode, rdev);
+#ifdef CONFIG_EXT3_FS_XATTR
+                inode->i_op = &ext3_special_inode_operations;
+#endif
+                err = ext3_add_nondir(handle, dentry, inode);
+        }
+        ext3_journal_stop(handle);
+        if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
+                goto retry;
+        return err;
+}
+
+static int ext3_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+{
+        handle_t *handle;
+        struct inode * inode;
+        struct buffer_head * dir_block;
+        struct ext3_dir_entry_2 * de;
+        int err, retries = 0;
+
+        if (dir->i_nlink >= EXT3_LINK_MAX)
+                return -EMLINK;
+
+retry:
+        handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS +
+                                        EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+                                        2*EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        inode = ext3_new_inode (handle, dir, S_IFDIR | mode);
+        err = PTR_ERR(inode);
+        if (IS_ERR(inode))
+                goto out_stop;
+
+        inode->i_op = &ext3_dir_inode_operations;
+        inode->i_fop = &ext3_dir_operations;
+        inode->i_size = EXT3_I(inode)->i_disksize = inode->i_sb->s_blocksize;
+        dir_block = ext3_bread (handle, inode, 0, 1, &err);
+        if (!dir_block) {
+                inode->i_nlink--; /* is this nlink == 0? */
+                ext3_mark_inode_dirty(handle, inode);
+                iput (inode);
+                goto out_stop;
+        }
+        BUFFER_TRACE(dir_block, "get_write_access");
+        ext3_journal_get_write_access(handle, dir_block);
+        de = (struct ext3_dir_entry_2 *) dir_block->b_data;
+        de->inode = cpu_to_le32(inode->i_ino);
+        de->name_len = 1;
+        de->rec_len = cpu_to_le16(EXT3_DIR_REC_LEN(de->name_len));
+        strcpy (de->name, ".");
+        ext3_set_de_type(dir->i_sb, de, S_IFDIR);
+        de = (struct ext3_dir_entry_2 *)
+                        ((char *) de + le16_to_cpu(de->rec_len));
+        de->inode = cpu_to_le32(dir->i_ino);
+        de->rec_len = cpu_to_le16(inode->i_sb->s_blocksize-EXT3_DIR_REC_LEN(1));
+        de->name_len = 2;
+        strcpy (de->name, "..");
+        ext3_set_de_type(dir->i_sb, de, S_IFDIR);
+        inode->i_nlink = 2;
+        BUFFER_TRACE(dir_block, "call ext3_journal_dirty_metadata");
+        ext3_journal_dirty_metadata(handle, dir_block);
+        brelse (dir_block);
+        ext3_mark_inode_dirty(handle, inode);
+        err = ext3_add_entry (handle, dentry, inode);
+        if (err) {
+                inode->i_nlink = 0;
+                ext3_mark_inode_dirty(handle, inode);
+                iput (inode);
+                goto out_stop;
+        }
+        dir->i_nlink++;
+        ext3_update_dx_flag(dir);
+        ext3_mark_inode_dirty(handle, dir);
+        d_instantiate(dentry, inode);
+out_stop:
+        ext3_journal_stop(handle);
+        if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
+                goto retry;
+        return err;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+static int empty_dir (struct inode * inode)
+{
+        unsigned long offset;
+        struct buffer_head * bh;
+        struct ext3_dir_entry_2 * de, * de1;
+        struct super_block * sb;
+        int err = 0;
+
+        sb = inode->i_sb;
+        if (inode->i_size < EXT3_DIR_REC_LEN(1) + EXT3_DIR_REC_LEN(2) ||
+            !(bh = ext3_bread (NULL, inode, 0, 0, &err))) {
+                if (err)
+                        ext3_error(inode->i_sb, __FUNCTION__,
+                                   "error %d reading directory #%lu offset 0",
+                                   err, inode->i_ino);
+                else
+                        ext3_warning(inode->i_sb, __FUNCTION__,
+                                     "bad directory (dir #%lu) - no data block",
+                                     inode->i_ino);
+                return 1;
+        }
+        de = (struct ext3_dir_entry_2 *) bh->b_data;
+        de1 = (struct ext3_dir_entry_2 *)
+                        ((char *) de + le16_to_cpu(de->rec_len));
+        if (le32_to_cpu(de->inode) != inode->i_ino ||
+                        !le32_to_cpu(de1->inode) || 
+                        strcmp (".", de->name) ||
+                        strcmp ("..", de1->name)) {
+                ext3_warning (inode->i_sb, "empty_dir",
+                              "bad directory (dir #%lu) - no `.' or `..'",
+                              inode->i_ino);
+                brelse (bh);
+                return 1;
+        }
+        offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
+        de = (struct ext3_dir_entry_2 *)
+                        ((char *) de1 + le16_to_cpu(de1->rec_len));
+        while (offset < inode->i_size ) {
+                if (!bh ||
+                        (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
+                        err = 0;
+                        brelse (bh);
+                        bh = ext3_bread (NULL, inode,
+                                offset >> EXT3_BLOCK_SIZE_BITS(sb), 0, &err);
+                        if (!bh) {
+                                if (err)
+                                        ext3_error(sb, __FUNCTION__,
+                                                   "error %d reading directory"
+                                                   " #%lu offset %lu",
+                                                   err, inode->i_ino, offset);
+                                offset += sb->s_blocksize;
+                                continue;
+                        }
+                        de = (struct ext3_dir_entry_2 *) bh->b_data;
+                }
+                if (!ext3_check_dir_entry("empty_dir", inode, de, bh, offset)) {
+                        de = (struct ext3_dir_entry_2 *)(bh->b_data +
+                                                         sb->s_blocksize);
+                        offset = (offset | (sb->s_blocksize - 1)) + 1;
+                        continue;
+                }
+                if (le32_to_cpu(de->inode)) {
+                        brelse (bh);
+                        return 0;
+                }
+                offset += le16_to_cpu(de->rec_len);
+                de = (struct ext3_dir_entry_2 *)
+                                ((char *) de + le16_to_cpu(de->rec_len));
+        }
+        brelse (bh);
+        return 1;
+}
+
+/* ext3_orphan_add() links an unlinked or truncated inode into a list of
+ * such inodes, starting at the superblock, in case we crash before the
+ * file is closed/deleted, or in case the inode truncate spans multiple
+ * transactions and the last transaction is not recovered after a crash.
+ *
+ * At filesystem recovery time, we walk this list deleting unlinked
+ * inodes and truncating linked inodes in ext3_orphan_cleanup().
+ */
+int ext3_orphan_add(handle_t *handle, struct inode *inode)
+{
+        struct super_block *sb = inode->i_sb;
+        struct ext3_iloc iloc;
+        int err = 0, rc;
+
+        lock_super(sb);
+        if (!list_empty(&EXT3_I(inode)->i_orphan))
+                goto out_unlock;
+
+        /* Orphan handling is only valid for files with data blocks
+         * being truncated, or files being unlinked. */
+
+        /* @@@ FIXME: Observation from aviro:
+         * I think I can trigger J_ASSERT in ext3_orphan_add().  We block 
+         * here (on lock_super()), so race with ext3_link() which might bump
+         * ->i_nlink. For, say it, character device. Not a regular file,
+         * not a directory, not a symlink and ->i_nlink > 0.
+         */
+        J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+                S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
+
+        BUFFER_TRACE(EXT3_SB(sb)->s_sbh, "get_write_access");
+        err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh);
+        if (err)
+                goto out_unlock;
+
+        err = ext3_reserve_inode_write(handle, inode, &iloc);
+        if (err)
+                goto out_unlock;
+
+        /* Insert this inode at the head of the on-disk orphan list... */
+        NEXT_ORPHAN(inode) = le32_to_cpu(EXT3_SB(sb)->s_es->s_last_orphan);
+        EXT3_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
+        err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
+        rc = ext3_mark_iloc_dirty(handle, inode, &iloc);
+        if (!err)
+                err = rc;
+
+        /* Only add to the head of the in-memory list if all the
+         * previous operations succeeded.  If the orphan_add is going to
+         * fail (possibly taking the journal offline), we can't risk
+         * leaving the inode on the orphan list: stray orphan-list
+         * entries can cause panics at unmount time.
+         *
+         * This is safe: on error we're going to ignore the orphan list
+         * anyway on the next recovery. */
+        if (!err)
+                list_add(&EXT3_I(inode)->i_orphan, &EXT3_SB(sb)->s_orphan);
+
+        jbd_debug(4, "superblock will point to %ld\n", inode->i_ino);
+        jbd_debug(4, "orphan inode %ld will point to %d\n",
+                        inode->i_ino, NEXT_ORPHAN(inode));
+out_unlock:
+        unlock_super(sb);
+        ext3_std_error(inode->i_sb, err);
+        return err;
+}
+
+/*
+ * ext3_orphan_del() removes an unlinked or truncated inode from the list
+ * of such inodes stored on disk, because it is finally being cleaned up.
+ */
+int ext3_orphan_del(handle_t *handle, struct inode *inode)
+{
+        struct list_head *prev;
+        struct ext3_inode_info *ei = EXT3_I(inode);
+        struct ext3_sb_info *sbi;
+        unsigned long ino_next;
+        struct ext3_iloc iloc;
+        int err = 0;
+
+        lock_super(inode->i_sb);
+        if (list_empty(&ei->i_orphan)) {
+                unlock_super(inode->i_sb);
+                return 0;
+        }
+
+        ino_next = NEXT_ORPHAN(inode);
+        prev = ei->i_orphan.prev;
+        sbi = EXT3_SB(inode->i_sb);
+
+        jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
+
+        list_del_init(&ei->i_orphan);
+
+        /* If we're on an error path, we may not have a valid
+         * transaction handle with which to update the orphan list on
+         * disk, but we still need to remove the inode from the linked
+         * list in memory. */
+        if (!handle)
+                goto out;
+
+        err = ext3_reserve_inode_write(handle, inode, &iloc);
+        if (err)
+                goto out_err;
+
+        if (prev == &sbi->s_orphan) {
+                jbd_debug(4, "superblock will point to %lu\n", ino_next);
+                BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+                err = ext3_journal_get_write_access(handle, sbi->s_sbh);
+                if (err)
+                        goto out_brelse;
+                sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
+                err = ext3_journal_dirty_metadata(handle, sbi->s_sbh);
+        } else {
+                struct ext3_iloc iloc2;
+                struct inode *i_prev =
+                        &list_entry(prev, struct ext3_inode_info, i_orphan)->vfs_inode;
+
+                jbd_debug(4, "orphan inode %lu will point to %lu\n",
+                          i_prev->i_ino, ino_next);
+                err = ext3_reserve_inode_write(handle, i_prev, &iloc2);
+                if (err)
+                        goto out_brelse;
+                NEXT_ORPHAN(i_prev) = ino_next;
+                err = ext3_mark_iloc_dirty(handle, i_prev, &iloc2);
+        }
+        if (err)
+                goto out_brelse;
+        NEXT_ORPHAN(inode) = 0;
+        err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+
+out_err:
+        ext3_std_error(inode->i_sb, err);
+out:
+        unlock_super(inode->i_sb);
+        return err;
+
+out_brelse:
+        brelse(iloc.bh);
+        goto out_err;
+}
+
+static int ext3_rmdir (struct inode * dir, struct dentry *dentry)
+{
+        int retval;
+        struct inode * inode;
+        struct buffer_head * bh;
+        struct ext3_dir_entry_2 * de;
+        handle_t *handle;
+
+        /* Initialize quotas before so that eventual writes go in
+         * separate transaction */
+        DQUOT_INIT(dentry->d_inode);
+        handle = ext3_journal_start(dir, EXT3_DELETE_TRANS_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        retval = -ENOENT;
+        bh = ext3_find_entry (dentry, &de);
+        if (!bh)
+                goto end_rmdir;
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        inode = dentry->d_inode;
+
+        retval = -EIO;
+        if (le32_to_cpu(de->inode) != inode->i_ino)
+                goto end_rmdir;
+
+        retval = -ENOTEMPTY;
+        if (!empty_dir (inode))
+                goto end_rmdir;
+
+        retval = ext3_delete_entry(handle, dir, de, bh);
+        if (retval)
+                goto end_rmdir;
+        if (inode->i_nlink != 2)
+                ext3_warning (inode->i_sb, "ext3_rmdir",
+                              "empty directory has nlink!=2 (%d)",
+                              inode->i_nlink);
+        inode->i_version++;
+        inode->i_nlink = 0;
+        /* There's no need to set i_disksize: the fact that i_nlink is
+         * zero will ensure that the right thing happens during any
+         * recovery. */
+        inode->i_size = 0;
+        ext3_orphan_add(handle, inode);
+        inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+        ext3_mark_inode_dirty(handle, inode);
+        dir->i_nlink--;
+        ext3_update_dx_flag(dir);
+        ext3_mark_inode_dirty(handle, dir);
+
+end_rmdir:
+        ext3_journal_stop(handle);
+        brelse (bh);
+        return retval;
+}
+
+static int ext3_unlink(struct inode * dir, struct dentry *dentry)
+{
+        int retval;
+        struct inode * inode;
+        struct buffer_head * bh;
+        struct ext3_dir_entry_2 * de;
+        handle_t *handle;
+
+        /* Initialize quotas before so that eventual writes go
+         * in separate transaction */
+        DQUOT_INIT(dentry->d_inode);
+        handle = ext3_journal_start(dir, EXT3_DELETE_TRANS_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        retval = -ENOENT;
+        bh = ext3_find_entry (dentry, &de);
+        if (!bh)
+                goto end_unlink;
+
+        inode = dentry->d_inode;
+
+        retval = -EIO;
+        if (le32_to_cpu(de->inode) != inode->i_ino)
+                goto end_unlink;
+
+        if (!inode->i_nlink) {
+                ext3_warning (inode->i_sb, "ext3_unlink",
+                              "Deleting nonexistent file (%lu), %d",
+                              inode->i_ino, inode->i_nlink);
+                inode->i_nlink = 1;
+        }
+        retval = ext3_delete_entry(handle, dir, de, bh);
+        if (retval)
+                goto end_unlink;
+        dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+        ext3_update_dx_flag(dir);
+        ext3_mark_inode_dirty(handle, dir);
+        inode->i_nlink--;
+        if (!inode->i_nlink)
+                ext3_orphan_add(handle, inode);
+        inode->i_ctime = dir->i_ctime;
+        ext3_mark_inode_dirty(handle, inode);
+        retval = 0;
+
+end_unlink:
+        ext3_journal_stop(handle);
+        brelse (bh);
+        return retval;
+}
+
+static int ext3_symlink (struct inode * dir,
+                struct dentry *dentry, const char * symname)
+{
+        handle_t *handle;
+        struct inode * inode;
+        int l, err, retries = 0;
+
+        l = strlen(symname)+1;
+        if (l > dir->i_sb->s_blocksize)
+                return -ENAMETOOLONG;
+
+retry:
+        handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS +
+                                        EXT3_INDEX_EXTRA_TRANS_BLOCKS + 5 +
+                                        2*EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        inode = ext3_new_inode (handle, dir, S_IFLNK|S_IRWXUGO);
+        err = PTR_ERR(inode);
+        if (IS_ERR(inode))
+                goto out_stop;
+
+        if (l > sizeof (EXT3_I(inode)->i_data)) {
+                inode->i_op = &ext3_symlink_inode_operations;
+                ext3_set_aops(inode);
+                /*
+                 * page_symlink() calls into ext3_prepare/commit_write.
+                 * We have a transaction open.  All is sweetness.  It also sets
+                 * i_size in generic_commit_write().
+                 */
+                err = page_symlink(inode, symname, l);
+                if (err) {
+                        ext3_dec_count(handle, inode);
+                        ext3_mark_inode_dirty(handle, inode);
+                        iput (inode);
+                        goto out_stop;
+                }
+        } else {
+                inode->i_op = &ext3_fast_symlink_inode_operations;
+                memcpy((char*)&EXT3_I(inode)->i_data,symname,l);
+                inode->i_size = l-1;
+        }
+        EXT3_I(inode)->i_disksize = inode->i_size;
+        err = ext3_add_nondir(handle, dentry, inode);
+out_stop:
+        ext3_journal_stop(handle);
+        if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
+                goto retry;
+        return err;
+}
+
+static int ext3_link (struct dentry * old_dentry,
+                struct inode * dir, struct dentry *dentry)
+{
+        handle_t *handle;
+        struct inode *inode = old_dentry->d_inode;
+        int err, retries = 0;
+
+        if (inode->i_nlink >= EXT3_LINK_MAX)
+                return -EMLINK;
+
+retry:
+        handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS +
+                                        EXT3_INDEX_EXTRA_TRANS_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(dir))
+                handle->h_sync = 1;
+
+        inode->i_ctime = CURRENT_TIME_SEC;
+        ext3_inc_count(handle, inode);
+        atomic_inc(&inode->i_count);
+
+        err = ext3_add_nondir(handle, dentry, inode);
+        ext3_journal_stop(handle);
+        if (err == -ENOSPC && ext3_should_retry_alloc(dir->i_sb, &retries))
+                goto retry;
+        return err;
+}
+
+#define PARENT_INO(buffer) \
+        ((struct ext3_dir_entry_2 *) ((char *) buffer + \
+        le16_to_cpu(((struct ext3_dir_entry_2 *) buffer)->rec_len)))->inode
+
+/*
+ * Anybody can rename anything with this: the permission checks are left to the
+ * higher-level routines.
+ */
+static int ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
+                           struct inode * new_dir,struct dentry *new_dentry)
+{
+        handle_t *handle;
+        struct inode * old_inode, * new_inode;
+        struct buffer_head * old_bh, * new_bh, * dir_bh;
+        struct ext3_dir_entry_2 * old_de, * new_de;
+        int retval;
+
+        old_bh = new_bh = dir_bh = NULL;
+
+        /* Initialize quotas before so that eventual writes go
+         * in separate transaction */
+        if (new_dentry->d_inode)
+                DQUOT_INIT(new_dentry->d_inode);
+        handle = ext3_journal_start(old_dir, 2 * EXT3_DATA_TRANS_BLOCKS +
+                                        EXT3_INDEX_EXTRA_TRANS_BLOCKS + 2);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+                handle->h_sync = 1;
+
+        old_bh = ext3_find_entry (old_dentry, &old_de);
+        /*
+         *  Check for inode number is _not_ due to possible IO errors.
+         *  We might rmdir the source, keep it as pwd of some process
+         *  and merrily kill the link to whatever was created under the
+         *  same name. Goodbye sticky bit ;-<
+         */
+        old_inode = old_dentry->d_inode;
+        retval = -ENOENT;
+        if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
+                goto end_rename;
+
+        new_inode = new_dentry->d_inode;
+        new_bh = ext3_find_entry (new_dentry, &new_de);
+        if (new_bh) {
+                if (!new_inode) {
+                        brelse (new_bh);
+                        new_bh = NULL;
+                }
+        }
+        if (S_ISDIR(old_inode->i_mode)) {
+                if (new_inode) {
+                        retval = -ENOTEMPTY;
+                        if (!empty_dir (new_inode))
+                                goto end_rename;
+                }
+                retval = -EIO;
+                dir_bh = ext3_bread (handle, old_inode, 0, 0, &retval);
+                if (!dir_bh)
+                        goto end_rename;
+                if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
+                        goto end_rename;
+                retval = -EMLINK;
+                if (!new_inode && new_dir!=old_dir &&
+                                new_dir->i_nlink >= EXT3_LINK_MAX)
+                        goto end_rename;
+        }
+        if (!new_bh) {
+                retval = ext3_add_entry (handle, new_dentry, old_inode);
+                if (retval)
+                        goto end_rename;
+        } else {
+                BUFFER_TRACE(new_bh, "get write access");
+                ext3_journal_get_write_access(handle, new_bh);
+                new_de->inode = cpu_to_le32(old_inode->i_ino);
+                if (EXT3_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
+                                              EXT3_FEATURE_INCOMPAT_FILETYPE))
+                        new_de->file_type = old_de->file_type;
+                new_dir->i_version++;
+                BUFFER_TRACE(new_bh, "call ext3_journal_dirty_metadata");
+                ext3_journal_dirty_metadata(handle, new_bh);
+                brelse(new_bh);
+                new_bh = NULL;
+        }
+
+        /*
+         * Like most other Unix systems, set the ctime for inodes on a
+         * rename.
+         */
+        old_inode->i_ctime = CURRENT_TIME_SEC;
+        ext3_mark_inode_dirty(handle, old_inode);
+
+        /*
+         * ok, that's it
+         */
+        if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
+            old_de->name_len != old_dentry->d_name.len ||
+            strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
+            (retval = ext3_delete_entry(handle, old_dir,
+                                        old_de, old_bh)) == -ENOENT) {
+                /* old_de could have moved from under us during htree split, so
+                 * make sure that we are deleting the right entry.  We might
+                 * also be pointing to a stale entry in the unused part of
+                 * old_bh so just checking inum and the name isn't enough. */
+                struct buffer_head *old_bh2;
+                struct ext3_dir_entry_2 *old_de2;
+
+                old_bh2 = ext3_find_entry(old_dentry, &old_de2);
+                if (old_bh2) {
+                        retval = ext3_delete_entry(handle, old_dir,
+                                                   old_de2, old_bh2);
+                        brelse(old_bh2);
+                }
+        }
+        if (retval) {
+                ext3_warning(old_dir->i_sb, "ext3_rename",
+                                "Deleting old file (%lu), %d, error=%d",
+                                old_dir->i_ino, old_dir->i_nlink, retval);
+        }
+
+        if (new_inode) {
+                new_inode->i_nlink--;
+                new_inode->i_ctime = CURRENT_TIME_SEC;
+        }
+        old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
+        ext3_update_dx_flag(old_dir);
+        if (dir_bh) {
+                BUFFER_TRACE(dir_bh, "get_write_access");
+                ext3_journal_get_write_access(handle, dir_bh);
+                PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
+                BUFFER_TRACE(dir_bh, "call ext3_journal_dirty_metadata");
+                ext3_journal_dirty_metadata(handle, dir_bh);
+                old_dir->i_nlink--;
+                if (new_inode) {
+                        new_inode->i_nlink--;
+                } else {
+                        new_dir->i_nlink++;
+                        ext3_update_dx_flag(new_dir);
+                        ext3_mark_inode_dirty(handle, new_dir);
+                }
+        }
+        ext3_mark_inode_dirty(handle, old_dir);
+        if (new_inode) {
+                ext3_mark_inode_dirty(handle, new_inode);
+                if (!new_inode->i_nlink)
+                        ext3_orphan_add(handle, new_inode);
+        }
+        retval = 0;
+
+end_rename:
+        brelse (dir_bh);
+        brelse (old_bh);
+        brelse (new_bh);
+        ext3_journal_stop(handle);
+        return retval;
+}
+
+/*
+ * directories can handle most operations...
+ */
+struct inode_operations ext3_dir_inode_operations = {
+        .create         = ext3_create,
+        .lookup         = ext3_lookup,
+        .link           = ext3_link,
+        .unlink         = ext3_unlink,
+        .symlink        = ext3_symlink,
+        .mkdir          = ext3_mkdir,
+        .rmdir          = ext3_rmdir,
+        .mknod          = ext3_mknod,
+        .rename         = ext3_rename,
+        .setattr        = ext3_setattr,
+#ifdef CONFIG_EXT3_FS_XATTR
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
+        .listxattr      = ext3_listxattr,
+        .removexattr    = generic_removexattr,
+#endif
+        .permission     = ext3_permission,
+};
+
+struct inode_operations ext3_special_inode_operations = {
+        .setattr        = ext3_setattr,
+#ifdef CONFIG_EXT3_FS_XATTR
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
+        .listxattr      = ext3_listxattr,
+        .removexattr    = generic_removexattr,
+#endif
+        .permission     = ext3_permission,
+}; 
diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c
new file mode 100644
index 000000000000..2c9f81278d5d
--- /dev/null
+++ b/fs/ext3/resize.c
@@ -0,0 +1,996 @@
+/*
+ *  linux/fs/ext3/resize.c
+ *
+ * Support for resizing an ext3 filesystem while it is mounted.
+ *
+ * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
+ *
+ * This could probably be made into a module, because it is not often in use.
+ */
+
+#include <linux/config.h>
+
+#define EXT3FS_DEBUG
+
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+
+
+#define outside(b, first, last) ((b) < (first) || (b) >= (last))
+#define inside(b, first, last)  ((b) >= (first) && (b) < (last))
+
+static int verify_group_input(struct super_block *sb,
+                              struct ext3_new_group_data *input)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        struct ext3_super_block *es = sbi->s_es;
+        unsigned start = le32_to_cpu(es->s_blocks_count);
+        unsigned end = start + input->blocks_count;
+        unsigned group = input->group;
+        unsigned itend = input->inode_table + EXT3_SB(sb)->s_itb_per_group;
+        unsigned overhead = ext3_bg_has_super(sb, group) ?
+                (1 + ext3_bg_num_gdb(sb, group) +
+                 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
+        unsigned metaend = start + overhead;
+        struct buffer_head *bh = NULL;
+        int free_blocks_count;
+        int err = -EINVAL;
+
+        input->free_blocks_count = free_blocks_count =
+                input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
+
+        if (test_opt(sb, DEBUG))
+                printk(KERN_DEBUG "EXT3-fs: adding %s group %u: %u blocks "
+                       "(%d free, %u reserved)\n",
+                       ext3_bg_has_super(sb, input->group) ? "normal" :
+                       "no-super", input->group, input->blocks_count,
+                       free_blocks_count, input->reserved_blocks);
+
+        if (group != sbi->s_groups_count)
+                ext3_warning(sb, __FUNCTION__,
+                             "Cannot add at group %u (only %lu groups)",
+                             input->group, sbi->s_groups_count);
+        else if ((start - le32_to_cpu(es->s_first_data_block)) %
+                 EXT3_BLOCKS_PER_GROUP(sb))
+                ext3_warning(sb, __FUNCTION__, "Last group not full");
+        else if (input->reserved_blocks > input->blocks_count / 5)
+                ext3_warning(sb, __FUNCTION__, "Reserved blocks too high (%u)",
+                             input->reserved_blocks);
+        else if (free_blocks_count < 0)
+                ext3_warning(sb, __FUNCTION__, "Bad blocks count %u",
+                             input->blocks_count);
+        else if (!(bh = sb_bread(sb, end - 1)))
+                ext3_warning(sb, __FUNCTION__, "Cannot read last block (%u)",
+                             end - 1);
+        else if (outside(input->block_bitmap, start, end))
+                ext3_warning(sb, __FUNCTION__,
+                             "Block bitmap not in group (block %u)",
+                             input->block_bitmap);
+        else if (outside(input->inode_bitmap, start, end))
+                ext3_warning(sb, __FUNCTION__,
+                             "Inode bitmap not in group (block %u)",
+                             input->inode_bitmap);
+        else if (outside(input->inode_table, start, end) ||
+                 outside(itend - 1, start, end))
+                ext3_warning(sb, __FUNCTION__,
+                             "Inode table not in group (blocks %u-%u)",
+                             input->inode_table, itend - 1);
+        else if (input->inode_bitmap == input->block_bitmap)
+                ext3_warning(sb, __FUNCTION__,
+                             "Block bitmap same as inode bitmap (%u)",
+                             input->block_bitmap);
+        else if (inside(input->block_bitmap, input->inode_table, itend))
+                ext3_warning(sb, __FUNCTION__,
+                             "Block bitmap (%u) in inode table (%u-%u)",
+                             input->block_bitmap, input->inode_table, itend-1);
+        else if (inside(input->inode_bitmap, input->inode_table, itend))
+                ext3_warning(sb, __FUNCTION__,
+                             "Inode bitmap (%u) in inode table (%u-%u)",
+                             input->inode_bitmap, input->inode_table, itend-1);
+        else if (inside(input->block_bitmap, start, metaend))
+                ext3_warning(sb, __FUNCTION__,
+                             "Block bitmap (%u) in GDT table (%u-%u)",
+                             input->block_bitmap, start, metaend - 1);
+        else if (inside(input->inode_bitmap, start, metaend))
+                ext3_warning(sb, __FUNCTION__,
+                             "Inode bitmap (%u) in GDT table (%u-%u)",
+                             input->inode_bitmap, start, metaend - 1);
+        else if (inside(input->inode_table, start, metaend) ||
+                 inside(itend - 1, start, metaend))
+                ext3_warning(sb, __FUNCTION__,
+                             "Inode table (%u-%u) overlaps GDT table (%u-%u)",
+                             input->inode_table, itend - 1, start, metaend - 1);
+        else
+                err = 0;
+        brelse(bh);
+
+        return err;
+}
+
+static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
+                                  unsigned long blk)
+{
+        struct buffer_head *bh;
+        int err;
+
+        bh = sb_getblk(sb, blk);
+        if ((err = ext3_journal_get_write_access(handle, bh))) {
+                brelse(bh);
+                bh = ERR_PTR(err);
+        } else {
+                lock_buffer(bh);
+                memset(bh->b_data, 0, sb->s_blocksize);
+                set_buffer_uptodate(bh);
+                unlock_buffer(bh);
+        }
+
+        return bh;
+}
+
+/*
+ * To avoid calling the atomic setbit hundreds or thousands of times, we only
+ * need to use it within a single byte (to ensure we get endianness right).
+ * We can use memset for the rest of the bitmap as there are no other users.
+ */
+static void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
+{
+        int i;
+
+        if (start_bit >= end_bit)
+                return;
+
+        ext3_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
+        for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
+                ext3_set_bit(i, bitmap);
+        if (i < end_bit)
+                memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
+}
+
+/*
+ * Set up the block and inode bitmaps, and the inode table for the new group.
+ * This doesn't need to be part of the main transaction, since we are only
+ * changing blocks outside the actual filesystem.  We still do journaling to
+ * ensure the recovery is correct in case of a failure just after resize.
+ * If any part of this fails, we simply abort the resize.
+ */
+static int setup_new_group_blocks(struct super_block *sb,
+                                  struct ext3_new_group_data *input)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        unsigned long start = input->group * sbi->s_blocks_per_group +
+                le32_to_cpu(sbi->s_es->s_first_data_block);
+        int reserved_gdb = ext3_bg_has_super(sb, input->group) ?
+                le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
+        unsigned long gdblocks = ext3_bg_num_gdb(sb, input->group);
+        struct buffer_head *bh;
+        handle_t *handle;
+        unsigned long block;
+        int bit;
+        int i;
+        int err = 0, err2;
+
+        handle = ext3_journal_start_sb(sb, reserved_gdb + gdblocks +
+                                       2 + sbi->s_itb_per_group);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+
+        lock_super(sb);
+        if (input->group != sbi->s_groups_count) {
+                err = -EBUSY;
+                goto exit_journal;
+        }
+
+        if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) {
+                err = PTR_ERR(bh);
+                goto exit_journal;
+        }
+
+        if (ext3_bg_has_super(sb, input->group)) {
+                ext3_debug("mark backup superblock %#04lx (+0)\n", start);
+                ext3_set_bit(0, bh->b_data);
+        }
+
+        /* Copy all of the GDT blocks into the backup in this group */
+        for (i = 0, bit = 1, block = start + 1;
+             i < gdblocks; i++, block++, bit++) {
+                struct buffer_head *gdb;
+
+                ext3_debug("update backup group %#04lx (+%d)\n", block, bit);
+
+                gdb = sb_getblk(sb, block);
+                if ((err = ext3_journal_get_write_access(handle, gdb))) {
+                        brelse(gdb);
+                        goto exit_bh;
+                }
+                lock_buffer(bh);
+                memcpy(gdb->b_data, sbi->s_group_desc[i], bh->b_size);
+                set_buffer_uptodate(gdb);
+                unlock_buffer(bh);
+                ext3_journal_dirty_metadata(handle, gdb);
+                ext3_set_bit(bit, bh->b_data);
+                brelse(gdb);
+        }
+
+        /* Zero out all of the reserved backup group descriptor table blocks */
+        for (i = 0, bit = gdblocks + 1, block = start + bit;
+             i < reserved_gdb; i++, block++, bit++) {
+                struct buffer_head *gdb;
+
+                ext3_debug("clear reserved block %#04lx (+%d)\n", block, bit);
+
+                if (IS_ERR(gdb = bclean(handle, sb, block))) {
+                        err = PTR_ERR(bh);
+                        goto exit_bh;
+                }
+                ext3_journal_dirty_metadata(handle, gdb);
+                ext3_set_bit(bit, bh->b_data);
+                brelse(gdb);
+        }
+        ext3_debug("mark block bitmap %#04x (+%ld)\n", input->block_bitmap,
+                   input->block_bitmap - start);
+        ext3_set_bit(input->block_bitmap - start, bh->b_data);
+        ext3_debug("mark inode bitmap %#04x (+%ld)\n", input->inode_bitmap,
+                   input->inode_bitmap - start);
+        ext3_set_bit(input->inode_bitmap - start, bh->b_data);
+
+        /* Zero out all of the inode table blocks */
+        for (i = 0, block = input->inode_table, bit = block - start;
+             i < sbi->s_itb_per_group; i++, bit++, block++) {
+                struct buffer_head *it;
+
+                ext3_debug("clear inode block %#04x (+%ld)\n", block, bit);
+                if (IS_ERR(it = bclean(handle, sb, block))) {
+                        err = PTR_ERR(it);
+                        goto exit_bh;
+                }
+                ext3_journal_dirty_metadata(handle, it);
+                brelse(it);
+                ext3_set_bit(bit, bh->b_data);
+        }
+        mark_bitmap_end(input->blocks_count, EXT3_BLOCKS_PER_GROUP(sb),
+                        bh->b_data);
+        ext3_journal_dirty_metadata(handle, bh);
+        brelse(bh);
+
+        /* Mark unused entries in inode bitmap used */
+        ext3_debug("clear inode bitmap %#04x (+%ld)\n",
+                   input->inode_bitmap, input->inode_bitmap - start);
+        if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
+                err = PTR_ERR(bh);
+                goto exit_journal;
+        }
+
+        mark_bitmap_end(EXT3_INODES_PER_GROUP(sb), EXT3_BLOCKS_PER_GROUP(sb),
+                        bh->b_data);
+        ext3_journal_dirty_metadata(handle, bh);
+exit_bh:
+        brelse(bh);
+
+exit_journal:
+        unlock_super(sb);
+        if ((err2 = ext3_journal_stop(handle)) && !err)
+                err = err2;
+
+        return err;
+}
+
+/*
+ * Iterate through the groups which hold BACKUP superblock/GDT copies in an
+ * ext3 filesystem.  The counters should be initialized to 1, 5, and 7 before
+ * calling this for the first time.  In a sparse filesystem it will be the
+ * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
+ * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
+ */
+static unsigned ext3_list_backups(struct super_block *sb, unsigned *three,
+                                  unsigned *five, unsigned *seven)
+{
+        unsigned *min = three;
+        int mult = 3;
+        unsigned ret;
+
+        if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
+                                        EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
+                ret = *min;
+                *min += 1;
+                return ret;
+        }
+
+        if (*five < *min) {
+                min = five;
+                mult = 5;
+        }
+        if (*seven < *min) {
+                min = seven;
+                mult = 7;
+        }
+
+        ret = *min;
+        *min *= mult;
+
+        return ret;
+}
+
+/*
+ * Check that all of the backup GDT blocks are held in the primary GDT block.
+ * It is assumed that they are stored in group order.  Returns the number of
+ * groups in current filesystem that have BACKUPS, or -ve error code.
+ */
+static int verify_reserved_gdb(struct super_block *sb,
+                               struct buffer_head *primary)
+{
+        const unsigned long blk = primary->b_blocknr;
+        const unsigned long end = EXT3_SB(sb)->s_groups_count;
+        unsigned three = 1;
+        unsigned five = 5;
+        unsigned seven = 7;
+        unsigned grp;
+        __u32 *p = (__u32 *)primary->b_data;
+        int gdbackups = 0;
+
+        while ((grp = ext3_list_backups(sb, &three, &five, &seven)) < end) {
+                if (le32_to_cpu(*p++) != grp * EXT3_BLOCKS_PER_GROUP(sb) + blk){
+                        ext3_warning(sb, __FUNCTION__,
+                                     "reserved GDT %ld missing grp %d (%ld)\n",
+                                     blk, grp,
+                                     grp * EXT3_BLOCKS_PER_GROUP(sb) + blk);
+                        return -EINVAL;
+                }
+                if (++gdbackups > EXT3_ADDR_PER_BLOCK(sb))
+                        return -EFBIG;
+        }
+
+        return gdbackups;
+}
+
+/*
+ * Called when we need to bring a reserved group descriptor table block into
+ * use from the resize inode.  The primary copy of the new GDT block currently
+ * is an indirect block (under the double indirect block in the resize inode).
+ * The new backup GDT blocks will be stored as leaf blocks in this indirect
+ * block, in group order.  Even though we know all the block numbers we need,
+ * we check to ensure that the resize inode has actually reserved these blocks.
+ *
+ * Don't need to update the block bitmaps because the blocks are still in use.
+ *
+ * We get all of the error cases out of the way, so that we are sure to not
+ * fail once we start modifying the data on disk, because JBD has no rollback.
+ */
+static int add_new_gdb(handle_t *handle, struct inode *inode,
+                       struct ext3_new_group_data *input,
+                       struct buffer_head **primary)
+{
+        struct super_block *sb = inode->i_sb;
+        struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+        unsigned long gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb);
+        unsigned long gdblock = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
+        struct buffer_head **o_group_desc, **n_group_desc;
+        struct buffer_head *dind;
+        int gdbackups;
+        struct ext3_iloc iloc;
+        __u32 *data;
+        int err;
+
+        if (test_opt(sb, DEBUG))
+                printk(KERN_DEBUG
+                       "EXT3-fs: ext3_add_new_gdb: adding group block %lu\n",
+                       gdb_num);
+
+        /*
+         * If we are not using the primary superblock/GDT copy don't resize,
+         * because the user tools have no way of handling this.  Probably a
+         * bad time to do it anyways.
+         */
+        if (EXT3_SB(sb)->s_sbh->b_blocknr !=
+            le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) {
+                ext3_warning(sb, __FUNCTION__,
+                        "won't resize using backup superblock at %llu\n",
+                        (unsigned long long)EXT3_SB(sb)->s_sbh->b_blocknr);
+                return -EPERM;
+        }
+
+        *primary = sb_bread(sb, gdblock);
+        if (!*primary)
+                return -EIO;
+
+        if ((gdbackups = verify_reserved_gdb(sb, *primary)) < 0) {
+                err = gdbackups;
+                goto exit_bh;
+        }
+
+        data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK;
+        dind = sb_bread(sb, le32_to_cpu(*data));
+        if (!dind) {
+                err = -EIO;
+                goto exit_bh;
+        }
+
+        data = (__u32 *)dind->b_data;
+        if (le32_to_cpu(data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)]) != gdblock) {
+                ext3_warning(sb, __FUNCTION__,
+                             "new group %u GDT block %lu not reserved\n",
+                             input->group, gdblock);
+                err = -EINVAL;
+                goto exit_dind;
+        }
+
+        if ((err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh)))
+                goto exit_dind;
+
+        if ((err = ext3_journal_get_write_access(handle, *primary)))
+                goto exit_sbh;
+
+        if ((err = ext3_journal_get_write_access(handle, dind)))
+                goto exit_primary;
+
+        /* ext3_reserve_inode_write() gets a reference on the iloc */
+        if ((err = ext3_reserve_inode_write(handle, inode, &iloc)))
+                goto exit_dindj;
+
+        n_group_desc = (struct buffer_head **)kmalloc((gdb_num + 1) *
+                                sizeof(struct buffer_head *), GFP_KERNEL);
+        if (!n_group_desc) {
+                err = -ENOMEM;
+                ext3_warning (sb, __FUNCTION__,
+                              "not enough memory for %lu groups", gdb_num + 1);
+                goto exit_inode;
+        }
+
+        /*
+         * Finally, we have all of the possible failures behind us...
+         *
+         * Remove new GDT block from inode double-indirect block and clear out
+         * the new GDT block for use (which also "frees" the backup GDT blocks
+         * from the reserved inode).  We don't need to change the bitmaps for
+         * these blocks, because they are marked as in-use from being in the
+         * reserved inode, and will become GDT blocks (primary and backup).
+         */
+        data[gdb_num % EXT3_ADDR_PER_BLOCK(sb)] = 0;
+        ext3_journal_dirty_metadata(handle, dind);
+        brelse(dind);
+        inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
+        ext3_mark_iloc_dirty(handle, inode, &iloc);
+        memset((*primary)->b_data, 0, sb->s_blocksize);
+        ext3_journal_dirty_metadata(handle, *primary);
+
+        o_group_desc = EXT3_SB(sb)->s_group_desc;
+        memcpy(n_group_desc, o_group_desc,
+               EXT3_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
+        n_group_desc[gdb_num] = *primary;
+        EXT3_SB(sb)->s_group_desc = n_group_desc;
+        EXT3_SB(sb)->s_gdb_count++;
+        kfree(o_group_desc);
+
+        es->s_reserved_gdt_blocks =
+                cpu_to_le16(le16_to_cpu(es->s_reserved_gdt_blocks) - 1);
+        ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
+
+        return 0;
+
+exit_inode:
+        //ext3_journal_release_buffer(handle, iloc.bh);
+        brelse(iloc.bh);
+exit_dindj:
+        //ext3_journal_release_buffer(handle, dind);
+exit_primary:
+        //ext3_journal_release_buffer(handle, *primary);
+exit_sbh:
+        //ext3_journal_release_buffer(handle, *primary);
+exit_dind:
+        brelse(dind);
+exit_bh:
+        brelse(*primary);
+
+        ext3_debug("leaving with error %d\n", err);
+        return err;
+}
+
+/*
+ * Called when we are adding a new group which has a backup copy of each of
+ * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
+ * We need to add these reserved backup GDT blocks to the resize inode, so
+ * that they are kept for future resizing and not allocated to files.
+ *
+ * Each reserved backup GDT block will go into a different indirect block.
+ * The indirect blocks are actually the primary reserved GDT blocks,
+ * so we know in advance what their block numbers are.  We only get the
+ * double-indirect block to verify it is pointing to the primary reserved
+ * GDT blocks so we don't overwrite a data block by accident.  The reserved
+ * backup GDT blocks are stored in their reserved primary GDT block.
+ */
+static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
+                              struct ext3_new_group_data *input)
+{
+        struct super_block *sb = inode->i_sb;
+        int reserved_gdb =le16_to_cpu(EXT3_SB(sb)->s_es->s_reserved_gdt_blocks);
+        struct buffer_head **primary;
+        struct buffer_head *dind;
+        struct ext3_iloc iloc;
+        unsigned long blk;
+        __u32 *data, *end;
+        int gdbackups = 0;
+        int res, i;
+        int err;
+
+        primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_KERNEL);
+        if (!primary)
+                return -ENOMEM;
+
+        data = EXT3_I(inode)->i_data + EXT3_DIND_BLOCK;
+        dind = sb_bread(sb, le32_to_cpu(*data));
+        if (!dind) {
+                err = -EIO;
+                goto exit_free;
+        }
+
+        blk = EXT3_SB(sb)->s_sbh->b_blocknr + 1 + EXT3_SB(sb)->s_gdb_count;
+        data = (__u32 *)dind->b_data + EXT3_SB(sb)->s_gdb_count;
+        end = (__u32 *)dind->b_data + EXT3_ADDR_PER_BLOCK(sb);
+
+        /* Get each reserved primary GDT block and verify it holds backups */
+        for (res = 0; res < reserved_gdb; res++, blk++) {
+                if (le32_to_cpu(*data) != blk) {
+                        ext3_warning(sb, __FUNCTION__,
+                                     "reserved block %lu not at offset %ld\n",
+                                     blk, (long)(data - (__u32 *)dind->b_data));
+                        err = -EINVAL;
+                        goto exit_bh;
+                }
+                primary[res] = sb_bread(sb, blk);
+                if (!primary[res]) {
+                        err = -EIO;
+                        goto exit_bh;
+                }
+                if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) {
+                        brelse(primary[res]);
+                        err = gdbackups;
+                        goto exit_bh;
+                }
+                if (++data >= end)
+                        data = (__u32 *)dind->b_data;
+        }
+
+        for (i = 0; i < reserved_gdb; i++) {
+                if ((err = ext3_journal_get_write_access(handle, primary[i]))) {
+                        /*
+                        int j;
+                        for (j = 0; j < i; j++)
+                                ext3_journal_release_buffer(handle, primary[j]);
+                         */
+                        goto exit_bh;
+                }
+        }
+
+        if ((err = ext3_reserve_inode_write(handle, inode, &iloc)))
+                goto exit_bh;
+
+        /*
+         * Finally we can add each of the reserved backup GDT blocks from
+         * the new group to its reserved primary GDT block.
+         */
+        blk = input->group * EXT3_BLOCKS_PER_GROUP(sb);
+        for (i = 0; i < reserved_gdb; i++) {
+                int err2;
+                data = (__u32 *)primary[i]->b_data;
+                /* printk("reserving backup %lu[%u] = %lu\n",
+                       primary[i]->b_blocknr, gdbackups,
+                       blk + primary[i]->b_blocknr); */
+                data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
+                err2 = ext3_journal_dirty_metadata(handle, primary[i]);
+                if (!err)
+                        err = err2;
+        }
+        inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
+        ext3_mark_iloc_dirty(handle, inode, &iloc);
+
+exit_bh:
+        while (--res >= 0)
+                brelse(primary[res]);
+        brelse(dind);
+
+exit_free:
+        kfree(primary);
+
+        return err;
+}
+
+/*
+ * Update the backup copies of the ext3 metadata.  These don't need to be part
+ * of the main resize transaction, because e2fsck will re-write them if there
+ * is a problem (basically only OOM will cause a problem).  However, we
+ * _should_ update the backups if possible, in case the primary gets trashed
+ * for some reason and we need to run e2fsck from a backup superblock.  The
+ * important part is that the new block and inode counts are in the backup
+ * superblocks, and the location of the new group metadata in the GDT backups.
+ *
+ * We do not need lock_super() for this, because these blocks are not
+ * otherwise touched by the filesystem code when it is mounted.  We don't
+ * need to worry about last changing from sbi->s_groups_count, because the
+ * worst that can happen is that we do not copy the full number of backups
+ * at this time.  The resize which changed s_groups_count will backup again.
+ */
+static void update_backups(struct super_block *sb,
+                           int blk_off, char *data, int size)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        const unsigned long last = sbi->s_groups_count;
+        const int bpg = EXT3_BLOCKS_PER_GROUP(sb);
+        unsigned three = 1;
+        unsigned five = 5;
+        unsigned seven = 7;
+        unsigned group;
+        int rest = sb->s_blocksize - size;
+        handle_t *handle;
+        int err = 0, err2;
+
+        handle = ext3_journal_start_sb(sb, EXT3_MAX_TRANS_DATA);
+        if (IS_ERR(handle)) {
+                group = 1;
+                err = PTR_ERR(handle);
+                goto exit_err;
+        }
+
+        while ((group = ext3_list_backups(sb, &three, &five, &seven)) < last) {
+                struct buffer_head *bh;
+
+                /* Out of journal space, and can't get more - abort - so sad */
+                if (handle->h_buffer_credits == 0 &&
+                    ext3_journal_extend(handle, EXT3_MAX_TRANS_DATA) &&
+                    (err = ext3_journal_restart(handle, EXT3_MAX_TRANS_DATA)))
+                        break;
+
+                bh = sb_getblk(sb, group * bpg + blk_off);
+                ext3_debug(sb, __FUNCTION__, "update metadata backup %#04lx\n",
+                           bh->b_blocknr);
+                if ((err = ext3_journal_get_write_access(handle, bh)))
+                        break;
+                lock_buffer(bh);
+                memcpy(bh->b_data, data, size);
+                if (rest)
+                        memset(bh->b_data + size, 0, rest);
+                set_buffer_uptodate(bh);
+                unlock_buffer(bh);
+                ext3_journal_dirty_metadata(handle, bh);
+                brelse(bh);
+        }
+        if ((err2 = ext3_journal_stop(handle)) && !err)
+                err = err2;
+
+        /*
+         * Ugh! Need to have e2fsck write the backup copies.  It is too
+         * late to revert the resize, we shouldn't fail just because of
+         * the backup copies (they are only needed in case of corruption).
+         *
+         * However, if we got here we have a journal problem too, so we
+         * can't really start a transaction to mark the superblock.
+         * Chicken out and just set the flag on the hope it will be written
+         * to disk, and if not - we will simply wait until next fsck.
+         */
+exit_err:
+        if (err) {
+                ext3_warning(sb, __FUNCTION__,
+                             "can't update backup for group %d (err %d), "
+                             "forcing fsck on next reboot\n", group, err);
+                sbi->s_mount_state &= ~EXT3_VALID_FS;
+                sbi->s_es->s_state &= ~cpu_to_le16(EXT3_VALID_FS);
+                mark_buffer_dirty(sbi->s_sbh);
+        }
+}
+
+/* Add group descriptor data to an existing or new group descriptor block.
+ * Ensure we handle all possible error conditions _before_ we start modifying
+ * the filesystem, because we cannot abort the transaction and not have it
+ * write the data to disk.
+ *
+ * If we are on a GDT block boundary, we need to get the reserved GDT block.
+ * Otherwise, we may need to add backup GDT blocks for a sparse group.
+ *
+ * We only need to hold the superblock lock while we are actually adding
+ * in the new group's counts to the superblock.  Prior to that we have
+ * not really "added" the group at all.  We re-check that we are still
+ * adding in the last group in case things have changed since verifying.
+ */
+int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        struct ext3_super_block *es = sbi->s_es;
+        int reserved_gdb = ext3_bg_has_super(sb, input->group) ?
+                le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
+        struct buffer_head *primary = NULL;
+        struct ext3_group_desc *gdp;
+        struct inode *inode = NULL;
+        handle_t *handle;
+        int gdb_off, gdb_num;
+        int err, err2;
+
+        gdb_num = input->group / EXT3_DESC_PER_BLOCK(sb);
+        gdb_off = input->group % EXT3_DESC_PER_BLOCK(sb);
+
+        if (gdb_off == 0 && !EXT3_HAS_RO_COMPAT_FEATURE(sb,
+                                        EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
+                ext3_warning(sb, __FUNCTION__,
+                             "Can't resize non-sparse filesystem further\n");
+                return -EPERM;
+        }
+
+        if (reserved_gdb || gdb_off == 0) {
+                if (!EXT3_HAS_COMPAT_FEATURE(sb,
+                                             EXT3_FEATURE_COMPAT_RESIZE_INODE)){
+                        ext3_warning(sb, __FUNCTION__,
+                                     "No reserved GDT blocks, can't resize\n");
+                        return -EPERM;
+                }
+                inode = iget(sb, EXT3_RESIZE_INO);
+                if (!inode || is_bad_inode(inode)) {
+                        ext3_warning(sb, __FUNCTION__,
+                                     "Error opening resize inode\n");
+                        iput(inode);
+                        return -ENOENT;
+                }
+        }
+
+        if ((err = verify_group_input(sb, input)))
+                goto exit_put;
+
+        if ((err = setup_new_group_blocks(sb, input)))
+                goto exit_put;
+
+        /*
+         * We will always be modifying at least the superblock and a GDT
+         * block.  If we are adding a group past the last current GDT block,
+         * we will also modify the inode and the dindirect block.  If we
+         * are adding a group with superblock/GDT backups  we will also
+         * modify each of the reserved GDT dindirect blocks.
+         */
+        handle = ext3_journal_start_sb(sb,
+                                       ext3_bg_has_super(sb, input->group) ?
+                                       3 + reserved_gdb : 4);
+        if (IS_ERR(handle)) {
+                err = PTR_ERR(handle);
+                goto exit_put;
+        }
+
+        lock_super(sb);
+        if (input->group != EXT3_SB(sb)->s_groups_count) {
+                ext3_warning(sb, __FUNCTION__,
+                             "multiple resizers run on filesystem!\n");
+                goto exit_journal;
+        }
+
+        if ((err = ext3_journal_get_write_access(handle, sbi->s_sbh)))
+                goto exit_journal;
+
+        /*
+         * We will only either add reserved group blocks to a backup group
+         * or remove reserved blocks for the first group in a new group block.
+         * Doing both would be mean more complex code, and sane people don't
+         * use non-sparse filesystems anymore.  This is already checked above.
+         */
+        if (gdb_off) {
+                primary = sbi->s_group_desc[gdb_num];
+                if ((err = ext3_journal_get_write_access(handle, primary)))
+                        goto exit_journal;
+
+                if (reserved_gdb && ext3_bg_num_gdb(sb, input->group) &&
+                    (err = reserve_backup_gdb(handle, inode, input)))
+                        goto exit_journal;
+        } else if ((err = add_new_gdb(handle, inode, input, &primary)))
+                goto exit_journal;
+
+        /*
+         * OK, now we've set up the new group.  Time to make it active.
+         *
+         * Current kernels don't lock all allocations via lock_super(),
+         * so we have to be safe wrt. concurrent accesses the group
+         * data.  So we need to be careful to set all of the relevant
+         * group descriptor data etc. *before* we enable the group.
+         *
+         * The key field here is EXT3_SB(sb)->s_groups_count: as long as
+         * that retains its old value, nobody is going to access the new
+         * group.
+         *
+         * So first we update all the descriptor metadata for the new
+         * group; then we update the total disk blocks count; then we
+         * update the groups count to enable the group; then finally we
+         * update the free space counts so that the system can start
+         * using the new disk blocks.
+         */
+
+        /* Update group descriptor block for new group */
+        gdp = (struct ext3_group_desc *)primary->b_data + gdb_off;
+
+        gdp->bg_block_bitmap = cpu_to_le32(input->block_bitmap);
+        gdp->bg_inode_bitmap = cpu_to_le32(input->inode_bitmap);
+        gdp->bg_inode_table = cpu_to_le32(input->inode_table);
+        gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count);
+        gdp->bg_free_inodes_count = cpu_to_le16(EXT3_INODES_PER_GROUP(sb));
+
+        /*
+         * Make the new blocks and inodes valid next.  We do this before
+         * increasing the group count so that once the group is enabled,
+         * all of its blocks and inodes are already valid.
+         *
+         * We always allocate group-by-group, then block-by-block or
+         * inode-by-inode within a group, so enabling these
+         * blocks/inodes before the group is live won't actually let us
+         * allocate the new space yet.
+         */
+        es->s_blocks_count = cpu_to_le32(le32_to_cpu(es->s_blocks_count) +
+                input->blocks_count);
+        es->s_inodes_count = cpu_to_le32(le32_to_cpu(es->s_inodes_count) +
+                EXT3_INODES_PER_GROUP(sb));
+
+        /*
+         * We need to protect s_groups_count against other CPUs seeing
+         * inconsistent state in the superblock.
+         *
+         * The precise rules we use are:
+         *
+         * * Writers of s_groups_count *must* hold lock_super
+         * AND
+         * * Writers must perform a smp_wmb() after updating all dependent
+         *   data and before modifying the groups count
+         *
+         * * Readers must hold lock_super() over the access
+         * OR
+         * * Readers must perform an smp_rmb() after reading the groups count
+         *   and before reading any dependent data.
+         *
+         * NB. These rules can be relaxed when checking the group count
+         * while freeing data, as we can only allocate from a block
+         * group after serialising against the group count, and we can
+         * only then free after serialising in turn against that
+         * allocation.
+         */
+        smp_wmb();
+
+        /* Update the global fs size fields */
+        EXT3_SB(sb)->s_groups_count++;
+
+        ext3_journal_dirty_metadata(handle, primary);
+
+        /* Update the reserved block counts only once the new group is
+         * active. */
+        es->s_r_blocks_count = cpu_to_le32(le32_to_cpu(es->s_r_blocks_count) +
+                input->reserved_blocks);
+
+        /* Update the free space counts */
+        percpu_counter_mod(&sbi->s_freeblocks_counter,
+                           input->free_blocks_count);
+        percpu_counter_mod(&sbi->s_freeinodes_counter,
+                           EXT3_INODES_PER_GROUP(sb));
+
+        ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
+        sb->s_dirt = 1;
+
+exit_journal:
+        unlock_super(sb);
+        if ((err2 = ext3_journal_stop(handle)) && !err)
+                err = err2;
+        if (!err) {
+                update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
+                               sizeof(struct ext3_super_block));
+                update_backups(sb, primary->b_blocknr, primary->b_data,
+                               primary->b_size);
+        }
+exit_put:
+        iput(inode);
+        return err;
+} /* ext3_group_add */
+
+/* Extend the filesystem to the new number of blocks specified.  This entry
+ * point is only used to extend the current filesystem to the end of the last
+ * existing group.  It can be accessed via ioctl, or by "remount,resize=<size>"
+ * for emergencies (because it has no dependencies on reserved blocks).
+ *
+ * If we _really_ wanted, we could use default values to call ext3_group_add()
+ * allow the "remount" trick to work for arbitrary resizing, assuming enough
+ * GDT blocks are reserved to grow to the desired size.
+ */
+int ext3_group_extend(struct super_block *sb, struct ext3_super_block *es,
+                      unsigned long n_blocks_count)
+{
+        unsigned long o_blocks_count;
+        unsigned long o_groups_count;
+        unsigned long last;
+        int add;
+        struct buffer_head * bh;
+        handle_t *handle;
+        int err, freed_blocks;
+
+        /* We don't need to worry about locking wrt other resizers just
+         * yet: we're going to revalidate es->s_blocks_count after
+         * taking lock_super() below. */
+        o_blocks_count = le32_to_cpu(es->s_blocks_count);
+        o_groups_count = EXT3_SB(sb)->s_groups_count;
+
+        if (test_opt(sb, DEBUG))
+                printk(KERN_DEBUG "EXT3-fs: extending last group from %lu to %lu blocks\n",
+                       o_blocks_count, n_blocks_count);
+
+        if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
+                return 0;
+
+        if (n_blocks_count < o_blocks_count) {
+                ext3_warning(sb, __FUNCTION__,
+                             "can't shrink FS - resize aborted");
+                return -EBUSY;
+        }
+
+        /* Handle the remaining blocks in the last group only. */
+        last = (o_blocks_count - le32_to_cpu(es->s_first_data_block)) %
+                EXT3_BLOCKS_PER_GROUP(sb);
+
+        if (last == 0) {
+                ext3_warning(sb, __FUNCTION__,
+                             "need to use ext2online to resize further\n");
+                return -EPERM;
+        }
+
+        add = EXT3_BLOCKS_PER_GROUP(sb) - last;
+
+        if (o_blocks_count + add > n_blocks_count)
+                add = n_blocks_count - o_blocks_count;
+
+        if (o_blocks_count + add < n_blocks_count)
+                ext3_warning(sb, __FUNCTION__,
+                             "will only finish group (%lu blocks, %u new)",
+                             o_blocks_count + add, add);
+
+        /* See if the device is actually as big as what was requested */
+        bh = sb_bread(sb, o_blocks_count + add -1);
+        if (!bh) {
+                ext3_warning(sb, __FUNCTION__,
+                             "can't read last block, resize aborted");
+                return -ENOSPC;
+        }
+        brelse(bh);
+
+        /* We will update the superblock, one block bitmap, and
+         * one group descriptor via ext3_free_blocks().
+         */
+        handle = ext3_journal_start_sb(sb, 3);
+        if (IS_ERR(handle)) {
+                err = PTR_ERR(handle);
+                ext3_warning(sb, __FUNCTION__, "error %d on journal start",err);
+                goto exit_put;
+        }
+
+        lock_super(sb);
+        if (o_blocks_count != le32_to_cpu(es->s_blocks_count)) {
+                ext3_warning(sb, __FUNCTION__,
+                             "multiple resizers run on filesystem!\n");
+                err = -EBUSY;
+                goto exit_put;
+        }
+
+        if ((err = ext3_journal_get_write_access(handle,
+                                                 EXT3_SB(sb)->s_sbh))) {
+                ext3_warning(sb, __FUNCTION__,
+                             "error %d on journal write access", err);
+                unlock_super(sb);
+                ext3_journal_stop(handle);
+                goto exit_put;
+        }
+        es->s_blocks_count = cpu_to_le32(o_blocks_count + add);
+        ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
+        sb->s_dirt = 1;
+        unlock_super(sb);
+        ext3_debug("freeing blocks %ld through %ld\n", o_blocks_count,
+                   o_blocks_count + add);
+        ext3_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks);
+        ext3_debug("freed blocks %ld through %ld\n", o_blocks_count,
+                   o_blocks_count + add);
+        if ((err = ext3_journal_stop(handle)))
+                goto exit_put;
+        if (test_opt(sb, DEBUG))
+                printk(KERN_DEBUG "EXT3-fs: extended group to %u blocks\n",
+                       le32_to_cpu(es->s_blocks_count));
+        update_backups(sb, EXT3_SB(sb)->s_sbh->b_blocknr, (char *)es,
+                       sizeof(struct ext3_super_block));
+exit_put:
+        return err;
+} /* ext3_group_extend */
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
new file mode 100644
index 000000000000..545b440a2d2f
--- /dev/null
+++ b/fs/ext3/super.c
@@ -0,0 +1,2539 @@
+/*
+ *  linux/fs/ext3/super.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/inode.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/parser.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <linux/vfs.h>
+#include <linux/random.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/quotaops.h>
+#include <asm/uaccess.h>
+#include "xattr.h"
+#include "acl.h"
+
+static int ext3_load_journal(struct super_block *, struct ext3_super_block *);
+static int ext3_create_journal(struct super_block *, struct ext3_super_block *,
+                               int);
+static void ext3_commit_super (struct super_block * sb,
+                               struct ext3_super_block * es,
+                               int sync);
+static void ext3_mark_recovery_complete(struct super_block * sb,
+                                        struct ext3_super_block * es);
+static void ext3_clear_journal_err(struct super_block * sb,
+                                   struct ext3_super_block * es);
+static int ext3_sync_fs(struct super_block *sb, int wait);
+static const char *ext3_decode_error(struct super_block * sb, int errno,
+                                     char nbuf[16]);
+static int ext3_remount (struct super_block * sb, int * flags, char * data);
+static int ext3_statfs (struct super_block * sb, struct kstatfs * buf);
+static void ext3_unlockfs(struct super_block *sb);
+static void ext3_write_super (struct super_block * sb);
+static void ext3_write_super_lockfs(struct super_block *sb);
+
+/* 
+ * Wrappers for journal_start/end.
+ *
+ * The only special thing we need to do here is to make sure that all
+ * journal_end calls result in the superblock being marked dirty, so
+ * that sync() will call the filesystem's write_super callback if
+ * appropriate. 
+ */
+handle_t *ext3_journal_start_sb(struct super_block *sb, int nblocks)
+{
+        journal_t *journal;
+
+        if (sb->s_flags & MS_RDONLY)
+                return ERR_PTR(-EROFS);
+
+        /* Special case here: if the journal has aborted behind our
+         * backs (eg. EIO in the commit thread), then we still need to
+         * take the FS itself readonly cleanly. */
+        journal = EXT3_SB(sb)->s_journal;
+        if (is_journal_aborted(journal)) {
+                ext3_abort(sb, __FUNCTION__,
+                           "Detected aborted journal");
+                return ERR_PTR(-EROFS);
+        }
+
+        return journal_start(journal, nblocks);
+}
+
+/* 
+ * The only special thing we need to do here is to make sure that all
+ * journal_stop calls result in the superblock being marked dirty, so
+ * that sync() will call the filesystem's write_super callback if
+ * appropriate. 
+ */
+int __ext3_journal_stop(const char *where, handle_t *handle)
+{
+        struct super_block *sb;
+        int err;
+        int rc;
+
+        sb = handle->h_transaction->t_journal->j_private;
+        err = handle->h_err;
+        rc = journal_stop(handle);
+
+        if (!err)
+                err = rc;
+        if (err)
+                __ext3_std_error(sb, where, err);
+        return err;
+}
+
+void ext3_journal_abort_handle(const char *caller, const char *err_fn,
+                struct buffer_head *bh, handle_t *handle, int err)
+{
+        char nbuf[16];
+        const char *errstr = ext3_decode_error(NULL, err, nbuf);
+
+        if (bh)
+                BUFFER_TRACE(bh, "abort");
+
+        if (!handle->h_err)
+                handle->h_err = err;
+
+        if (is_handle_aborted(handle))
+                return;
+
+        printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
+               caller, errstr, err_fn);
+
+        journal_abort_handle(handle);
+}
+
+/* Deal with the reporting of failure conditions on a filesystem such as
+ * inconsistencies detected or read IO failures.
+ *
+ * On ext2, we can store the error state of the filesystem in the
+ * superblock.  That is not possible on ext3, because we may have other
+ * write ordering constraints on the superblock which prevent us from
+ * writing it out straight away; and given that the journal is about to
+ * be aborted, we can't rely on the current, or future, transactions to
+ * write out the superblock safely.
+ *
+ * We'll just use the journal_abort() error code to record an error in
+ * the journal instead.  On recovery, the journal will compain about
+ * that error until we've noted it down and cleared it.
+ */
+
+static void ext3_handle_error(struct super_block *sb)
+{
+        struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+
+        EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
+        es->s_state |= cpu_to_le16(EXT3_ERROR_FS);
+
+        if (sb->s_flags & MS_RDONLY)
+                return;
+
+        if (test_opt (sb, ERRORS_RO)) {
+                printk (KERN_CRIT "Remounting filesystem read-only\n");
+                sb->s_flags |= MS_RDONLY;
+        } else {
+                journal_t *journal = EXT3_SB(sb)->s_journal;
+
+                EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT;
+                if (journal)
+                        journal_abort(journal, -EIO);
+        }
+        if (test_opt(sb, ERRORS_PANIC))
+                panic("EXT3-fs (device %s): panic forced after error\n",
+                        sb->s_id);
+        ext3_commit_super(sb, es, 1);
+}
+
+void ext3_error (struct super_block * sb, const char * function,
+                 const char * fmt, ...)
+{
+        va_list args;
+
+        va_start(args, fmt);
+        printk(KERN_CRIT "EXT3-fs error (device %s): %s: ",sb->s_id, function);
+        vprintk(fmt, args);
+        printk("\n");
+        va_end(args);
+
+        ext3_handle_error(sb);
+}
+
+static const char *ext3_decode_error(struct super_block * sb, int errno,
+                                     char nbuf[16])
+{
+        char *errstr = NULL;
+
+        switch (errno) {
+        case -EIO:
+                errstr = "IO failure";
+                break;
+        case -ENOMEM:
+                errstr = "Out of memory";
+                break;
+        case -EROFS:
+                if (!sb || EXT3_SB(sb)->s_journal->j_flags & JFS_ABORT)
+                        errstr = "Journal has aborted";
+                else
+                        errstr = "Readonly filesystem";
+                break;
+        default:
+                /* If the caller passed in an extra buffer for unknown
+                 * errors, textualise them now.  Else we just return
+                 * NULL. */
+                if (nbuf) {
+                        /* Check for truncated error codes... */
+                        if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
+                                errstr = nbuf;
+                }
+                break;
+        }
+
+        return errstr;
+}
+
+/* __ext3_std_error decodes expected errors from journaling functions
+ * automatically and invokes the appropriate error response.  */
+
+void __ext3_std_error (struct super_block * sb, const char * function,
+                       int errno)
+{
+        char nbuf[16];
+        const char *errstr = ext3_decode_error(sb, errno, nbuf);
+
+        printk (KERN_CRIT "EXT3-fs error (device %s) in %s: %s\n",
+                sb->s_id, function, errstr);
+
+        ext3_handle_error(sb);
+}
+
+/*
+ * ext3_abort is a much stronger failure handler than ext3_error.  The
+ * abort function may be used to deal with unrecoverable failures such
+ * as journal IO errors or ENOMEM at a critical moment in log management.
+ *
+ * We unconditionally force the filesystem into an ABORT|READONLY state,
+ * unless the error response on the fs has been set to panic in which
+ * case we take the easy way out and panic immediately.
+ */
+
+void ext3_abort (struct super_block * sb, const char * function,
+                 const char * fmt, ...)
+{
+        va_list args;
+
+        printk (KERN_CRIT "ext3_abort called.\n");
+
+        va_start(args, fmt);
+        printk(KERN_CRIT "EXT3-fs error (device %s): %s: ",sb->s_id, function);
+        vprintk(fmt, args);
+        printk("\n");
+        va_end(args);
+
+        if (test_opt(sb, ERRORS_PANIC))
+                panic("EXT3-fs panic from previous error\n");
+
+        if (sb->s_flags & MS_RDONLY)
+                return;
+
+        printk(KERN_CRIT "Remounting filesystem read-only\n");
+        EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
+        sb->s_flags |= MS_RDONLY;
+        EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT;
+        journal_abort(EXT3_SB(sb)->s_journal, -EIO);
+}
+
+void ext3_warning (struct super_block * sb, const char * function,
+                   const char * fmt, ...)
+{
+        va_list args;
+
+        va_start(args, fmt);
+        printk(KERN_WARNING "EXT3-fs warning (device %s): %s: ",
+               sb->s_id, function);
+        vprintk(fmt, args);
+        printk("\n");
+        va_end(args);
+}
+
+void ext3_update_dynamic_rev(struct super_block *sb)
+{
+        struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+
+        if (le32_to_cpu(es->s_rev_level) > EXT3_GOOD_OLD_REV)
+                return;
+
+        ext3_warning(sb, __FUNCTION__,
+                     "updating to rev %d because of new feature flag, "
+                     "running e2fsck is recommended",
+                     EXT3_DYNAMIC_REV);
+
+        es->s_first_ino = cpu_to_le32(EXT3_GOOD_OLD_FIRST_INO);
+        es->s_inode_size = cpu_to_le16(EXT3_GOOD_OLD_INODE_SIZE);
+        es->s_rev_level = cpu_to_le32(EXT3_DYNAMIC_REV);
+        /* leave es->s_feature_*compat flags alone */
+        /* es->s_uuid will be set by e2fsck if empty */
+
+        /*
+         * The rest of the superblock fields should be zero, and if not it
+         * means they are likely already in use, so leave them alone.  We
+         * can leave it up to e2fsck to clean up any inconsistencies there.
+         */
+}
+
+/*
+ * Open the external journal device
+ */
+static struct block_device *ext3_blkdev_get(dev_t dev)
+{
+        struct block_device *bdev;
+        char b[BDEVNAME_SIZE];
+
+        bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
+        if (IS_ERR(bdev))
+                goto fail;
+        return bdev;
+
+fail:
+        printk(KERN_ERR "EXT3: failed to open journal device %s: %ld\n",
+                        __bdevname(dev, b), PTR_ERR(bdev));
+        return NULL;
+}
+
+/*
+ * Release the journal device
+ */
+static int ext3_blkdev_put(struct block_device *bdev)
+{
+        bd_release(bdev);
+        return blkdev_put(bdev);
+}
+
+static int ext3_blkdev_remove(struct ext3_sb_info *sbi)
+{
+        struct block_device *bdev;
+        int ret = -ENODEV;
+
+        bdev = sbi->journal_bdev;
+        if (bdev) {
+                ret = ext3_blkdev_put(bdev);
+                sbi->journal_bdev = NULL;
+        }
+        return ret;
+}
+
+static inline struct inode *orphan_list_entry(struct list_head *l)
+{
+        return &list_entry(l, struct ext3_inode_info, i_orphan)->vfs_inode;
+}
+
+static void dump_orphan_list(struct super_block *sb, struct ext3_sb_info *sbi)
+{
+        struct list_head *l;
+
+        printk(KERN_ERR "sb orphan head is %d\n", 
+               le32_to_cpu(sbi->s_es->s_last_orphan));
+
+        printk(KERN_ERR "sb_info orphan list:\n");
+        list_for_each(l, &sbi->s_orphan) {
+                struct inode *inode = orphan_list_entry(l);
+                printk(KERN_ERR "  "
+                       "inode %s:%ld at %p: mode %o, nlink %d, next %d\n",
+                       inode->i_sb->s_id, inode->i_ino, inode,
+                       inode->i_mode, inode->i_nlink, 
+                       NEXT_ORPHAN(inode));
+        }
+}
+
+static void ext3_put_super (struct super_block * sb)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        struct ext3_super_block *es = sbi->s_es;
+        int i;
+
+        ext3_xattr_put_super(sb);
+        journal_destroy(sbi->s_journal);
+        if (!(sb->s_flags & MS_RDONLY)) {
+                EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+                es->s_state = cpu_to_le16(sbi->s_mount_state);
+                BUFFER_TRACE(sbi->s_sbh, "marking dirty");
+                mark_buffer_dirty(sbi->s_sbh);
+                ext3_commit_super(sb, es, 1);
+        }
+
+        for (i = 0; i < sbi->s_gdb_count; i++)
+                brelse(sbi->s_group_desc[i]);
+        kfree(sbi->s_group_desc);
+        percpu_counter_destroy(&sbi->s_freeblocks_counter);
+        percpu_counter_destroy(&sbi->s_freeinodes_counter);
+        percpu_counter_destroy(&sbi->s_dirs_counter);
+        brelse(sbi->s_sbh);
+#ifdef CONFIG_QUOTA
+        for (i = 0; i < MAXQUOTAS; i++)
+                kfree(sbi->s_qf_names[i]);
+#endif
+
+        /* Debugging code just in case the in-memory inode orphan list
+         * isn't empty.  The on-disk one can be non-empty if we've
+         * detected an error and taken the fs readonly, but the
+         * in-memory list had better be clean by this point. */
+        if (!list_empty(&sbi->s_orphan))
+                dump_orphan_list(sb, sbi);
+        J_ASSERT(list_empty(&sbi->s_orphan));
+
+        invalidate_bdev(sb->s_bdev, 0);
+        if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
+                /*
+                 * Invalidate the journal device's buffers.  We don't want them
+                 * floating about in memory - the physical journal device may
+                 * hotswapped, and it breaks the `ro-after' testing code.
+                 */
+                sync_blockdev(sbi->journal_bdev);
+                invalidate_bdev(sbi->journal_bdev, 0);
+                ext3_blkdev_remove(sbi);
+        }
+        sb->s_fs_info = NULL;
+        kfree(sbi);
+        return;
+}
+
+static kmem_cache_t *ext3_inode_cachep;
+
+/*
+ * Called inside transaction, so use GFP_NOFS
+ */
+static struct inode *ext3_alloc_inode(struct super_block *sb)
+{
+        struct ext3_inode_info *ei;
+
+        ei = kmem_cache_alloc(ext3_inode_cachep, SLAB_NOFS);
+        if (!ei)
+                return NULL;
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+        ei->i_acl = EXT3_ACL_NOT_CACHED;
+        ei->i_default_acl = EXT3_ACL_NOT_CACHED;
+#endif
+        ei->i_block_alloc_info = NULL;
+        ei->vfs_inode.i_version = 1;
+        return &ei->vfs_inode;
+}
+
+static void ext3_destroy_inode(struct inode *inode)
+{
+        kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
+}
+
+static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
+{
+        struct ext3_inode_info *ei = (struct ext3_inode_info *) foo;
+
+        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+            SLAB_CTOR_CONSTRUCTOR) {
+                INIT_LIST_HEAD(&ei->i_orphan);
+#ifdef CONFIG_EXT3_FS_XATTR
+                init_rwsem(&ei->xattr_sem);
+#endif
+                init_MUTEX(&ei->truncate_sem);
+                inode_init_once(&ei->vfs_inode);
+        }
+}
+ 
+static int init_inodecache(void)
+{
+        ext3_inode_cachep = kmem_cache_create("ext3_inode_cache",
+                                             sizeof(struct ext3_inode_info),
+                                             0, SLAB_RECLAIM_ACCOUNT,
+                                             init_once, NULL);
+        if (ext3_inode_cachep == NULL)
+                return -ENOMEM;
+        return 0;
+}
+
+static void destroy_inodecache(void)
+{
+        if (kmem_cache_destroy(ext3_inode_cachep))
+                printk(KERN_INFO "ext3_inode_cache: not all structures were freed\n");
+}
+
+static void ext3_clear_inode(struct inode *inode)
+{
+        struct ext3_block_alloc_info *rsv = EXT3_I(inode)->i_block_alloc_info;
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+       if (EXT3_I(inode)->i_acl &&
+           EXT3_I(inode)->i_acl != EXT3_ACL_NOT_CACHED) {
+               posix_acl_release(EXT3_I(inode)->i_acl);
+               EXT3_I(inode)->i_acl = EXT3_ACL_NOT_CACHED;
+       }
+       if (EXT3_I(inode)->i_default_acl &&
+           EXT3_I(inode)->i_default_acl != EXT3_ACL_NOT_CACHED) {
+               posix_acl_release(EXT3_I(inode)->i_default_acl);
+               EXT3_I(inode)->i_default_acl = EXT3_ACL_NOT_CACHED;
+       }
+#endif
+        ext3_discard_reservation(inode);
+        EXT3_I(inode)->i_block_alloc_info = NULL;
+        kfree(rsv);
+}
+
+#ifdef CONFIG_QUOTA
+
+#define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
+#define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
+
+static int ext3_dquot_initialize(struct inode *inode, int type);
+static int ext3_dquot_drop(struct inode *inode);
+static int ext3_write_dquot(struct dquot *dquot);
+static int ext3_acquire_dquot(struct dquot *dquot);
+static int ext3_release_dquot(struct dquot *dquot);
+static int ext3_mark_dquot_dirty(struct dquot *dquot);
+static int ext3_write_info(struct super_block *sb, int type);
+static int ext3_quota_on(struct super_block *sb, int type, int format_id, char *path);
+static int ext3_quota_on_mount(struct super_block *sb, int type);
+static ssize_t ext3_quota_read(struct super_block *sb, int type, char *data,
+                               size_t len, loff_t off);
+static ssize_t ext3_quota_write(struct super_block *sb, int type,
+                                const char *data, size_t len, loff_t off);
+
+static struct dquot_operations ext3_quota_operations = {
+        .initialize     = ext3_dquot_initialize,
+        .drop           = ext3_dquot_drop,
+        .alloc_space    = dquot_alloc_space,
+        .alloc_inode    = dquot_alloc_inode,
+        .free_space     = dquot_free_space,
+        .free_inode     = dquot_free_inode,
+        .transfer       = dquot_transfer,
+        .write_dquot    = ext3_write_dquot,
+        .acquire_dquot  = ext3_acquire_dquot,
+        .release_dquot  = ext3_release_dquot,
+        .mark_dirty     = ext3_mark_dquot_dirty,
+        .write_info     = ext3_write_info
+};
+
+static struct quotactl_ops ext3_qctl_operations = {
+        .quota_on       = ext3_quota_on,
+        .quota_off      = vfs_quota_off,
+        .quota_sync     = vfs_quota_sync,
+        .get_info       = vfs_get_dqinfo,
+        .set_info       = vfs_set_dqinfo,
+        .get_dqblk      = vfs_get_dqblk,
+        .set_dqblk      = vfs_set_dqblk
+};
+#endif
+
+static struct super_operations ext3_sops = {
+        .alloc_inode    = ext3_alloc_inode,
+        .destroy_inode  = ext3_destroy_inode,
+        .read_inode     = ext3_read_inode,
+        .write_inode    = ext3_write_inode,
+        .dirty_inode    = ext3_dirty_inode,
+        .delete_inode   = ext3_delete_inode,
+        .put_super      = ext3_put_super,
+        .write_super    = ext3_write_super,
+        .sync_fs        = ext3_sync_fs,
+        .write_super_lockfs = ext3_write_super_lockfs,
+        .unlockfs       = ext3_unlockfs,
+        .statfs         = ext3_statfs,
+        .remount_fs     = ext3_remount,
+        .clear_inode    = ext3_clear_inode,
+#ifdef CONFIG_QUOTA
+        .quota_read     = ext3_quota_read,
+        .quota_write    = ext3_quota_write,
+#endif
+};
+
+struct dentry *ext3_get_parent(struct dentry *child);
+static struct export_operations ext3_export_ops = {
+        .get_parent = ext3_get_parent,
+};
+
+enum {
+        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
+        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
+        Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
+        Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
+        Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh,
+        Opt_commit, Opt_journal_update, Opt_journal_inum,
+        Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
+        Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
+        Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0,
+        Opt_ignore, Opt_barrier, Opt_err, Opt_resize,
+};
+
+static match_table_t tokens = {
+        {Opt_bsd_df, "bsddf"},
+        {Opt_minix_df, "minixdf"},
+        {Opt_grpid, "grpid"},
+        {Opt_grpid, "bsdgroups"},
+        {Opt_nogrpid, "nogrpid"},
+        {Opt_nogrpid, "sysvgroups"},
+        {Opt_resgid, "resgid=%u"},
+        {Opt_resuid, "resuid=%u"},
+        {Opt_sb, "sb=%u"},
+        {Opt_err_cont, "errors=continue"},
+        {Opt_err_panic, "errors=panic"},
+        {Opt_err_ro, "errors=remount-ro"},
+        {Opt_nouid32, "nouid32"},
+        {Opt_nocheck, "nocheck"},
+        {Opt_nocheck, "check=none"},
+        {Opt_check, "check"},
+        {Opt_debug, "debug"},
+        {Opt_oldalloc, "oldalloc"},
+        {Opt_orlov, "orlov"},
+        {Opt_user_xattr, "user_xattr"},
+        {Opt_nouser_xattr, "nouser_xattr"},
+        {Opt_acl, "acl"},
+        {Opt_noacl, "noacl"},
+        {Opt_reservation, "reservation"},
+        {Opt_noreservation, "noreservation"},
+        {Opt_noload, "noload"},
+        {Opt_nobh, "nobh"},
+        {Opt_commit, "commit=%u"},
+        {Opt_journal_update, "journal=update"},
+        {Opt_journal_inum, "journal=%u"},
+        {Opt_abort, "abort"},
+        {Opt_data_journal, "data=journal"},
+        {Opt_data_ordered, "data=ordered"},
+        {Opt_data_writeback, "data=writeback"},
+        {Opt_offusrjquota, "usrjquota="},
+        {Opt_usrjquota, "usrjquota=%s"},
+        {Opt_offgrpjquota, "grpjquota="},
+        {Opt_grpjquota, "grpjquota=%s"},
+        {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
+        {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
+        {Opt_ignore, "grpquota"},
+        {Opt_ignore, "noquota"},
+        {Opt_ignore, "quota"},
+        {Opt_ignore, "usrquota"},
+        {Opt_barrier, "barrier=%u"},
+        {Opt_err, NULL},
+        {Opt_resize, "resize"},
+};
+
+static unsigned long get_sb_block(void **data)
+{
+        unsigned long   sb_block;
+        char            *options = (char *) *data;
+
+        if (!options || strncmp(options, "sb=", 3) != 0)
+                return 1;       /* Default location */
+        options += 3;
+        sb_block = simple_strtoul(options, &options, 0);
+        if (*options && *options != ',') {
+                printk("EXT3-fs: Invalid sb specification: %s\n",
+                       (char *) *data);
+                return 1;
+        }
+        if (*options == ',')
+                options++;
+        *data = (void *) options;
+        return sb_block;
+}
+
+static int parse_options (char * options, struct super_block *sb,
+                          unsigned long * inum, unsigned long *n_blocks_count, int is_remount)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        char * p;
+        substring_t args[MAX_OPT_ARGS];
+        int data_opt = 0;
+        int option;
+#ifdef CONFIG_QUOTA
+        int qtype;
+        char *qname;
+#endif
+
+        if (!options)
+                return 1;
+
+        while ((p = strsep (&options, ",")) != NULL) {
+                int token;
+                if (!*p)
+                        continue;
+
+                token = match_token(p, tokens, args);
+                switch (token) {
+                case Opt_bsd_df:
+                        clear_opt (sbi->s_mount_opt, MINIX_DF);
+                        break;
+                case Opt_minix_df:
+                        set_opt (sbi->s_mount_opt, MINIX_DF);
+                        break;
+                case Opt_grpid:
+                        set_opt (sbi->s_mount_opt, GRPID);
+                        break;
+                case Opt_nogrpid:
+                        clear_opt (sbi->s_mount_opt, GRPID);
+                        break;
+                case Opt_resuid:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        sbi->s_resuid = option;
+                        break;
+                case Opt_resgid:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        sbi->s_resgid = option;
+                        break;
+                case Opt_sb:
+                        /* handled by get_sb_block() instead of here */
+                        /* *sb_block = match_int(&args[0]); */
+                        break;
+                case Opt_err_panic:
+                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
+                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
+                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
+                        break;
+                case Opt_err_ro:
+                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
+                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
+                        set_opt (sbi->s_mount_opt, ERRORS_RO);
+                        break;
+                case Opt_err_cont:
+                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
+                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
+                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
+                        break;
+                case Opt_nouid32:
+                        set_opt (sbi->s_mount_opt, NO_UID32);
+                        break;
+                case Opt_check:
+#ifdef CONFIG_EXT3_CHECK
+                        set_opt (sbi->s_mount_opt, CHECK);
+#else
+                        printk(KERN_ERR
+                               "EXT3 Check option not supported\n");
+#endif
+                        break;
+                case Opt_nocheck:
+                        clear_opt (sbi->s_mount_opt, CHECK);
+                        break;
+                case Opt_debug:
+                        set_opt (sbi->s_mount_opt, DEBUG);
+                        break;
+                case Opt_oldalloc:
+                        set_opt (sbi->s_mount_opt, OLDALLOC);
+                        break;
+                case Opt_orlov:
+                        clear_opt (sbi->s_mount_opt, OLDALLOC);
+                        break;
+#ifdef CONFIG_EXT3_FS_XATTR
+                case Opt_user_xattr:
+                        set_opt (sbi->s_mount_opt, XATTR_USER);
+                        break;
+                case Opt_nouser_xattr:
+                        clear_opt (sbi->s_mount_opt, XATTR_USER);
+                        break;
+#else
+                case Opt_user_xattr:
+                case Opt_nouser_xattr:
+                        printk("EXT3 (no)user_xattr options not supported\n");
+                        break;
+#endif
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+                case Opt_acl:
+                        set_opt(sbi->s_mount_opt, POSIX_ACL);
+                        break;
+                case Opt_noacl:
+                        clear_opt(sbi->s_mount_opt, POSIX_ACL);
+                        break;
+#else
+                case Opt_acl:
+                case Opt_noacl:
+                        printk("EXT3 (no)acl options not supported\n");
+                        break;
+#endif
+                case Opt_reservation:
+                        set_opt(sbi->s_mount_opt, RESERVATION);
+                        break;
+                case Opt_noreservation:
+                        clear_opt(sbi->s_mount_opt, RESERVATION);
+                        break;
+                case Opt_journal_update:
+                        /* @@@ FIXME */
+                        /* Eventually we will want to be able to create
+                           a journal file here.  For now, only allow the
+                           user to specify an existing inode to be the
+                           journal file. */
+                        if (is_remount) {
+                                printk(KERN_ERR "EXT3-fs: cannot specify "
+                                       "journal on remount\n");
+                                return 0;
+                        }
+                        set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
+                        break;
+                case Opt_journal_inum:
+                        if (is_remount) {
+                                printk(KERN_ERR "EXT3-fs: cannot specify "
+                                       "journal on remount\n");
+                                return 0;
+                        }
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        *inum = option;
+                        break;
+                case Opt_noload:
+                        set_opt (sbi->s_mount_opt, NOLOAD);
+                        break;
+                case Opt_commit:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        if (option < 0)
+                                return 0;
+                        if (option == 0)
+                                option = JBD_DEFAULT_MAX_COMMIT_AGE;
+                        sbi->s_commit_interval = HZ * option;
+                        break;
+                case Opt_data_journal:
+                        data_opt = EXT3_MOUNT_JOURNAL_DATA;
+                        goto datacheck;
+                case Opt_data_ordered:
+                        data_opt = EXT3_MOUNT_ORDERED_DATA;
+                        goto datacheck;
+                case Opt_data_writeback:
+                        data_opt = EXT3_MOUNT_WRITEBACK_DATA;
+                datacheck:
+                        if (is_remount) {
+                                if ((sbi->s_mount_opt & EXT3_MOUNT_DATA_FLAGS)
+                                                != data_opt) {
+                                        printk(KERN_ERR
+                                                "EXT3-fs: cannot change data "
+                                                "mode on remount\n");
+                                        return 0;
+                                }
+                        } else {
+                                sbi->s_mount_opt &= ~EXT3_MOUNT_DATA_FLAGS;
+                                sbi->s_mount_opt |= data_opt;
+                        }
+                        break;
+#ifdef CONFIG_QUOTA
+                case Opt_usrjquota:
+                        qtype = USRQUOTA;
+                        goto set_qf_name;
+                case Opt_grpjquota:
+                        qtype = GRPQUOTA;
+set_qf_name:
+                        if (sb_any_quota_enabled(sb)) {
+                                printk(KERN_ERR
+                                        "EXT3-fs: Cannot change journalled "
+                                        "quota options when quota turned on.\n");
+                                return 0;
+                        }
+                        qname = match_strdup(&args[0]);
+                        if (!qname) {
+                                printk(KERN_ERR
+                                        "EXT3-fs: not enough memory for "
+                                        "storing quotafile name.\n");
+                                return 0;
+                        }
+                        if (sbi->s_qf_names[qtype] &&
+                            strcmp(sbi->s_qf_names[qtype], qname)) {
+                                printk(KERN_ERR
+                                        "EXT3-fs: %s quota file already "
+                                        "specified.\n", QTYPE2NAME(qtype));
+                                kfree(qname);
+                                return 0;
+                        }
+                        sbi->s_qf_names[qtype] = qname;
+                        if (strchr(sbi->s_qf_names[qtype], '/')) {
+                                printk(KERN_ERR
+                                        "EXT3-fs: quotafile must be on "
+                                        "filesystem root.\n");
+                                kfree(sbi->s_qf_names[qtype]);
+                                sbi->s_qf_names[qtype] = NULL;
+                                return 0;
+                        }
+                        break;
+                case Opt_offusrjquota:
+                        qtype = USRQUOTA;
+                        goto clear_qf_name;
+                case Opt_offgrpjquota:
+                        qtype = GRPQUOTA;
+clear_qf_name:
+                        if (sb_any_quota_enabled(sb)) {
+                                printk(KERN_ERR "EXT3-fs: Cannot change "
+                                        "journalled quota options when "
+                                        "quota turned on.\n");
+                                return 0;
+                        }
+                        kfree(sbi->s_qf_names[qtype]);
+                        sbi->s_qf_names[qtype] = NULL;
+                        break;
+                case Opt_jqfmt_vfsold:
+                        sbi->s_jquota_fmt = QFMT_VFS_OLD;
+                        break;
+                case Opt_jqfmt_vfsv0:
+                        sbi->s_jquota_fmt = QFMT_VFS_V0;
+                        break;
+#else
+                case Opt_usrjquota:
+                case Opt_grpjquota:
+                case Opt_offusrjquota:
+                case Opt_offgrpjquota:
+                case Opt_jqfmt_vfsold:
+                case Opt_jqfmt_vfsv0:
+                        printk(KERN_ERR
+                                "EXT3-fs: journalled quota options not "
+                                "supported.\n");
+                        break;
+#endif
+                case Opt_abort:
+                        set_opt(sbi->s_mount_opt, ABORT);
+                        break;
+                case Opt_barrier:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        if (option)
+                                set_opt(sbi->s_mount_opt, BARRIER);
+                        else
+                                clear_opt(sbi->s_mount_opt, BARRIER);
+                        break;
+                case Opt_ignore:
+                        break;
+                case Opt_resize:
+                        if (!n_blocks_count) {
+                                printk("EXT3-fs: resize option only available "
+                                        "for remount\n");
+                                return 0;
+                        }
+                        match_int(&args[0], &option);
+                        *n_blocks_count = option;
+                        break;
+                case Opt_nobh:
+                        set_opt(sbi->s_mount_opt, NOBH);
+                        break;
+                default:
+                        printk (KERN_ERR
+                                "EXT3-fs: Unrecognized mount option \"%s\" "
+                                "or missing value\n", p);
+                        return 0;
+                }
+        }
+#ifdef CONFIG_QUOTA
+        if (!sbi->s_jquota_fmt && (sbi->s_qf_names[USRQUOTA] ||
+            sbi->s_qf_names[GRPQUOTA])) {
+                printk(KERN_ERR
+                        "EXT3-fs: journalled quota format not specified.\n");
+                return 0;
+        }
+#endif
+
+        return 1;
+}
+
+static int ext3_setup_super(struct super_block *sb, struct ext3_super_block *es,
+                            int read_only)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        int res = 0;
+
+        if (le32_to_cpu(es->s_rev_level) > EXT3_MAX_SUPP_REV) {
+                printk (KERN_ERR "EXT3-fs warning: revision level too high, "
+                        "forcing read-only mode\n");
+                res = MS_RDONLY;
+        }
+        if (read_only)
+                return res;
+        if (!(sbi->s_mount_state & EXT3_VALID_FS))
+                printk (KERN_WARNING "EXT3-fs warning: mounting unchecked fs, "
+                        "running e2fsck is recommended\n");
+        else if ((sbi->s_mount_state & EXT3_ERROR_FS))
+                printk (KERN_WARNING
+                        "EXT3-fs warning: mounting fs with errors, "
+                        "running e2fsck is recommended\n");
+        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
+                 le16_to_cpu(es->s_mnt_count) >=
+                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
+                printk (KERN_WARNING
+                        "EXT3-fs warning: maximal mount count reached, "
+                        "running e2fsck is recommended\n");
+        else if (le32_to_cpu(es->s_checkinterval) &&
+                (le32_to_cpu(es->s_lastcheck) +
+                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
+                printk (KERN_WARNING
+                        "EXT3-fs warning: checktime reached, "
+                        "running e2fsck is recommended\n");
+#if 0
+                /* @@@ We _will_ want to clear the valid bit if we find
+                   inconsistencies, to force a fsck at reboot.  But for
+                   a plain journaled filesystem we can keep it set as
+                   valid forever! :) */
+        es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT3_VALID_FS);
+#endif
+        if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
+                es->s_max_mnt_count = cpu_to_le16(EXT3_DFL_MAX_MNT_COUNT);
+        es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
+        es->s_mtime = cpu_to_le32(get_seconds());
+        ext3_update_dynamic_rev(sb);
+        EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+
+        ext3_commit_super(sb, es, 1);
+        if (test_opt(sb, DEBUG))
+                printk(KERN_INFO "[EXT3 FS bs=%lu, gc=%lu, "
+                                "bpg=%lu, ipg=%lu, mo=%04lx]\n",
+                        sb->s_blocksize,
+                        sbi->s_groups_count,
+                        EXT3_BLOCKS_PER_GROUP(sb),
+                        EXT3_INODES_PER_GROUP(sb),
+                        sbi->s_mount_opt);
+
+        printk(KERN_INFO "EXT3 FS on %s, ", sb->s_id);
+        if (EXT3_SB(sb)->s_journal->j_inode == NULL) {
+                char b[BDEVNAME_SIZE];
+
+                printk("external journal on %s\n",
+                        bdevname(EXT3_SB(sb)->s_journal->j_dev, b));
+        } else {
+                printk("internal journal\n");
+        }
+#ifdef CONFIG_EXT3_CHECK
+        if (test_opt (sb, CHECK)) {
+                ext3_check_blocks_bitmap (sb);
+                ext3_check_inodes_bitmap (sb);
+        }
+#endif
+        return res;
+}
+
+/* Called at mount-time, super-block is locked */
+static int ext3_check_descriptors (struct super_block * sb)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
+        struct ext3_group_desc * gdp = NULL;
+        int desc_block = 0;
+        int i;
+
+        ext3_debug ("Checking group descriptors");
+
+        for (i = 0; i < sbi->s_groups_count; i++)
+        {
+                if ((i % EXT3_DESC_PER_BLOCK(sb)) == 0)
+                        gdp = (struct ext3_group_desc *)
+                                        sbi->s_group_desc[desc_block++]->b_data;
+                if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
+                    le32_to_cpu(gdp->bg_block_bitmap) >=
+                                block + EXT3_BLOCKS_PER_GROUP(sb))
+                {
+                        ext3_error (sb, "ext3_check_descriptors",
+                                    "Block bitmap for group %d"
+                                    " not in group (block %lu)!",
+                                    i, (unsigned long)
+                                        le32_to_cpu(gdp->bg_block_bitmap));
+                        return 0;
+                }
+                if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
+                    le32_to_cpu(gdp->bg_inode_bitmap) >=
+                                block + EXT3_BLOCKS_PER_GROUP(sb))
+                {
+                        ext3_error (sb, "ext3_check_descriptors",
+                                    "Inode bitmap for group %d"
+                                    " not in group (block %lu)!",
+                                    i, (unsigned long)
+                                        le32_to_cpu(gdp->bg_inode_bitmap));
+                        return 0;
+                }
+                if (le32_to_cpu(gdp->bg_inode_table) < block ||
+                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
+                    block + EXT3_BLOCKS_PER_GROUP(sb))
+                {
+                        ext3_error (sb, "ext3_check_descriptors",
+                                    "Inode table for group %d"
+                                    " not in group (block %lu)!",
+                                    i, (unsigned long)
+                                        le32_to_cpu(gdp->bg_inode_table));
+                        return 0;
+                }
+                block += EXT3_BLOCKS_PER_GROUP(sb);
+                gdp++;
+        }
+
+        sbi->s_es->s_free_blocks_count=cpu_to_le32(ext3_count_free_blocks(sb));
+        sbi->s_es->s_free_inodes_count=cpu_to_le32(ext3_count_free_inodes(sb));
+        return 1;
+}
+
+
+/* ext3_orphan_cleanup() walks a singly-linked list of inodes (starting at
+ * the superblock) which were deleted from all directories, but held open by
+ * a process at the time of a crash.  We walk the list and try to delete these
+ * inodes at recovery time (only with a read-write filesystem).
+ *
+ * In order to keep the orphan inode chain consistent during traversal (in
+ * case of crash during recovery), we link each inode into the superblock
+ * orphan list_head and handle it the same way as an inode deletion during
+ * normal operation (which journals the operations for us).
+ *
+ * We only do an iget() and an iput() on each inode, which is very safe if we
+ * accidentally point at an in-use or already deleted inode.  The worst that
+ * can happen in this case is that we get a "bit already cleared" message from
+ * ext3_free_inode().  The only reason we would point at a wrong inode is if
+ * e2fsck was run on this filesystem, and it must have already done the orphan
+ * inode cleanup for us, so we can safely abort without any further action.
+ */
+static void ext3_orphan_cleanup (struct super_block * sb,
+                                 struct ext3_super_block * es)
+{
+        unsigned int s_flags = sb->s_flags;
+        int nr_orphans = 0, nr_truncates = 0;
+#ifdef CONFIG_QUOTA
+        int i;
+#endif
+        if (!es->s_last_orphan) {
+                jbd_debug(4, "no orphan inodes to clean up\n");
+                return;
+        }
+
+        if (EXT3_SB(sb)->s_mount_state & EXT3_ERROR_FS) {
+                if (es->s_last_orphan)
+                        jbd_debug(1, "Errors on filesystem, "
+                                  "clearing orphan list.\n");
+                es->s_last_orphan = 0;
+                jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
+                return;
+        }
+
+        if (s_flags & MS_RDONLY) {
+                printk(KERN_INFO "EXT3-fs: %s: orphan cleanup on readonly fs\n",
+                       sb->s_id);
+                sb->s_flags &= ~MS_RDONLY;
+        }
+#ifdef CONFIG_QUOTA
+        /* Needed for iput() to work correctly and not trash data */
+        sb->s_flags |= MS_ACTIVE;
+        /* Turn on quotas so that they are updated correctly */
+        for (i = 0; i < MAXQUOTAS; i++) {
+                if (EXT3_SB(sb)->s_qf_names[i]) {
+                        int ret = ext3_quota_on_mount(sb, i);
+                        if (ret < 0)
+                                printk(KERN_ERR
+                                        "EXT3-fs: Cannot turn on journalled "
+                                        "quota: error %d\n", ret);
+                }
+        }
+#endif
+
+        while (es->s_last_orphan) {
+                struct inode *inode;
+
+                if (!(inode =
+                      ext3_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
+                        es->s_last_orphan = 0;
+                        break;
+                }
+
+                list_add(&EXT3_I(inode)->i_orphan, &EXT3_SB(sb)->s_orphan);
+                DQUOT_INIT(inode);
+                if (inode->i_nlink) {
+                        printk(KERN_DEBUG
+                                "%s: truncating inode %ld to %Ld bytes\n",
+                                __FUNCTION__, inode->i_ino, inode->i_size);
+                        jbd_debug(2, "truncating inode %ld to %Ld bytes\n",
+                                  inode->i_ino, inode->i_size);
+                        ext3_truncate(inode);
+                        nr_truncates++;
+                } else {
+                        printk(KERN_DEBUG
+                                "%s: deleting unreferenced inode %ld\n",
+                                __FUNCTION__, inode->i_ino);
+                        jbd_debug(2, "deleting unreferenced inode %ld\n",
+                                  inode->i_ino);
+                        nr_orphans++;
+                }
+                iput(inode);  /* The delete magic happens here! */
+        }
+
+#define PLURAL(x) (x), ((x)==1) ? "" : "s"
+
+        if (nr_orphans)
+                printk(KERN_INFO "EXT3-fs: %s: %d orphan inode%s deleted\n",
+                       sb->s_id, PLURAL(nr_orphans));
+        if (nr_truncates)
+                printk(KERN_INFO "EXT3-fs: %s: %d truncate%s cleaned up\n",
+                       sb->s_id, PLURAL(nr_truncates));
+#ifdef CONFIG_QUOTA
+        /* Turn quotas off */
+        for (i = 0; i < MAXQUOTAS; i++) {
+                if (sb_dqopt(sb)->files[i])
+                        vfs_quota_off(sb, i);
+        }
+#endif
+        sb->s_flags = s_flags; /* Restore MS_RDONLY status */
+}
+
+#define log2(n) ffz(~(n))
+
+/*
+ * Maximal file size.  There is a direct, and {,double-,triple-}indirect
+ * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
+ * We need to be 1 filesystem block less than the 2^32 sector limit.
+ */
+static loff_t ext3_max_size(int bits)
+{
+        loff_t res = EXT3_NDIR_BLOCKS;
+        /* This constant is calculated to be the largest file size for a
+         * dense, 4k-blocksize file such that the total number of
+         * sectors in the file, including data and all indirect blocks,
+         * does not exceed 2^32. */
+        const loff_t upper_limit = 0x1ff7fffd000LL;
+
+        res += 1LL << (bits-2);
+        res += 1LL << (2*(bits-2));
+        res += 1LL << (3*(bits-2));
+        res <<= bits;
+        if (res > upper_limit)
+                res = upper_limit;
+        return res;
+}
+
+static unsigned long descriptor_loc(struct super_block *sb,
+                                    unsigned long logic_sb_block,
+                                    int nr)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        unsigned long bg, first_data_block, first_meta_bg;
+        int has_super = 0;
+
+        first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
+
+        if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_META_BG) ||
+            nr < first_meta_bg)
+                return (logic_sb_block + nr + 1);
+        bg = sbi->s_desc_per_block * nr;
+        if (ext3_bg_has_super(sb, bg))
+                has_super = 1;
+        return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
+}
+
+
+static int ext3_fill_super (struct super_block *sb, void *data, int silent)
+{
+        struct buffer_head * bh;
+        struct ext3_super_block *es = NULL;
+        struct ext3_sb_info *sbi;
+        unsigned long block;
+        unsigned long sb_block = get_sb_block(&data);
+        unsigned long logic_sb_block;
+        unsigned long offset = 0;
+        unsigned long journal_inum = 0;
+        unsigned long def_mount_opts;
+        struct inode *root;
+        int blocksize;
+        int hblock;
+        int db_count;
+        int i;
+        int needs_recovery;
+        __le32 features;
+
+        sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
+        if (!sbi)
+                return -ENOMEM;
+        sb->s_fs_info = sbi;
+        memset(sbi, 0, sizeof(*sbi));
+        sbi->s_mount_opt = 0;
+        sbi->s_resuid = EXT3_DEF_RESUID;
+        sbi->s_resgid = EXT3_DEF_RESGID;
+
+        unlock_kernel();
+
+        blocksize = sb_min_blocksize(sb, EXT3_MIN_BLOCK_SIZE);
+        if (!blocksize) {
+                printk(KERN_ERR "EXT3-fs: unable to set blocksize\n");
+                goto out_fail;
+        }
+
+        /*
+         * The ext3 superblock will not be buffer aligned for other than 1kB
+         * block sizes.  We need to calculate the offset from buffer start.
+         */
+        if (blocksize != EXT3_MIN_BLOCK_SIZE) {
+                logic_sb_block = (sb_block * EXT3_MIN_BLOCK_SIZE) / blocksize;
+                offset = (sb_block * EXT3_MIN_BLOCK_SIZE) % blocksize;
+        } else {
+                logic_sb_block = sb_block;
+        }
+
+        if (!(bh = sb_bread(sb, logic_sb_block))) {
+                printk (KERN_ERR "EXT3-fs: unable to read superblock\n");
+                goto out_fail;
+        }
+        /*
+         * Note: s_es must be initialized as soon as possible because
+         *       some ext3 macro-instructions depend on its value
+         */
+        es = (struct ext3_super_block *) (((char *)bh->b_data) + offset);
+        sbi->s_es = es;
+        sb->s_magic = le16_to_cpu(es->s_magic);
+        if (sb->s_magic != EXT3_SUPER_MAGIC)
+                goto cantfind_ext3;
+
+        /* Set defaults before we parse the mount options */
+        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+        if (def_mount_opts & EXT3_DEFM_DEBUG)
+                set_opt(sbi->s_mount_opt, DEBUG);
+        if (def_mount_opts & EXT3_DEFM_BSDGROUPS)
+                set_opt(sbi->s_mount_opt, GRPID);
+        if (def_mount_opts & EXT3_DEFM_UID16)
+                set_opt(sbi->s_mount_opt, NO_UID32);
+        if (def_mount_opts & EXT3_DEFM_XATTR_USER)
+                set_opt(sbi->s_mount_opt, XATTR_USER);
+        if (def_mount_opts & EXT3_DEFM_ACL)
+                set_opt(sbi->s_mount_opt, POSIX_ACL);
+        if ((def_mount_opts & EXT3_DEFM_JMODE) == EXT3_DEFM_JMODE_DATA)
+                sbi->s_mount_opt |= EXT3_MOUNT_JOURNAL_DATA;
+        else if ((def_mount_opts & EXT3_DEFM_JMODE) == EXT3_DEFM_JMODE_ORDERED)
+                sbi->s_mount_opt |= EXT3_MOUNT_ORDERED_DATA;
+        else if ((def_mount_opts & EXT3_DEFM_JMODE) == EXT3_DEFM_JMODE_WBACK)
+                sbi->s_mount_opt |= EXT3_MOUNT_WRITEBACK_DATA;
+
+        if (le16_to_cpu(sbi->s_es->s_errors) == EXT3_ERRORS_PANIC)
+                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
+        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT3_ERRORS_RO)
+                set_opt(sbi->s_mount_opt, ERRORS_RO);
+
+        sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
+        sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
+
+        set_opt(sbi->s_mount_opt, RESERVATION);
+
+        if (!parse_options ((char *) data, sb, &journal_inum, NULL, 0))
+                goto failed_mount;
+
+        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+                ((sbi->s_mount_opt & EXT3_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
+
+        if (le32_to_cpu(es->s_rev_level) == EXT3_GOOD_OLD_REV &&
+            (EXT3_HAS_COMPAT_FEATURE(sb, ~0U) ||
+             EXT3_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
+             EXT3_HAS_INCOMPAT_FEATURE(sb, ~0U)))
+                printk(KERN_WARNING 
+                       "EXT3-fs warning: feature flags set on rev 0 fs, "
+                       "running e2fsck is recommended\n");
+        /*
+         * Check feature flags regardless of the revision level, since we
+         * previously didn't change the revision level when setting the flags,
+         * so there is a chance incompat flags are set on a rev 0 filesystem.
+         */
+        features = EXT3_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP);
+        if (features) {
+                printk(KERN_ERR "EXT3-fs: %s: couldn't mount because of "
+                       "unsupported optional features (%x).\n",
+                       sb->s_id, le32_to_cpu(features));
+                goto failed_mount;
+        }
+        features = EXT3_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP);
+        if (!(sb->s_flags & MS_RDONLY) && features) {
+                printk(KERN_ERR "EXT3-fs: %s: couldn't mount RDWR because of "
+                       "unsupported optional features (%x).\n",
+                       sb->s_id, le32_to_cpu(features));
+                goto failed_mount;
+        }
+        blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
+
+        if (blocksize < EXT3_MIN_BLOCK_SIZE ||
+            blocksize > EXT3_MAX_BLOCK_SIZE) {
+                printk(KERN_ERR 
+                       "EXT3-fs: Unsupported filesystem blocksize %d on %s.\n",
+                       blocksize, sb->s_id);
+                goto failed_mount;
+        }
+
+        hblock = bdev_hardsect_size(sb->s_bdev);
+        if (sb->s_blocksize != blocksize) {
+                /*
+                 * Make sure the blocksize for the filesystem is larger
+                 * than the hardware sectorsize for the machine.
+                 */
+                if (blocksize < hblock) {
+                        printk(KERN_ERR "EXT3-fs: blocksize %d too small for "
+                               "device blocksize %d.\n", blocksize, hblock);
+                        goto failed_mount;
+                }
+
+                brelse (bh);
+                sb_set_blocksize(sb, blocksize);
+                logic_sb_block = (sb_block * EXT3_MIN_BLOCK_SIZE) / blocksize;
+                offset = (sb_block * EXT3_MIN_BLOCK_SIZE) % blocksize;
+                bh = sb_bread(sb, logic_sb_block);
+                if (!bh) {
+                        printk(KERN_ERR 
+                               "EXT3-fs: Can't read superblock on 2nd try.\n");
+                        goto failed_mount;
+                }
+                es = (struct ext3_super_block *)(((char *)bh->b_data) + offset);
+                sbi->s_es = es;
+                if (es->s_magic != cpu_to_le16(EXT3_SUPER_MAGIC)) {
+                        printk (KERN_ERR 
+                                "EXT3-fs: Magic mismatch, very weird !\n");
+                        goto failed_mount;
+                }
+        }
+
+        sb->s_maxbytes = ext3_max_size(sb->s_blocksize_bits);
+
+        if (le32_to_cpu(es->s_rev_level) == EXT3_GOOD_OLD_REV) {
+                sbi->s_inode_size = EXT3_GOOD_OLD_INODE_SIZE;
+                sbi->s_first_ino = EXT3_GOOD_OLD_FIRST_INO;
+        } else {
+                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
+                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
+                if ((sbi->s_inode_size < EXT3_GOOD_OLD_INODE_SIZE) ||
+                    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
+                    (sbi->s_inode_size > blocksize)) {
+                        printk (KERN_ERR
+                                "EXT3-fs: unsupported inode size: %d\n",
+                                sbi->s_inode_size);
+                        goto failed_mount;
+                }
+        }
+        sbi->s_frag_size = EXT3_MIN_FRAG_SIZE <<
+                                   le32_to_cpu(es->s_log_frag_size);
+        if (blocksize != sbi->s_frag_size) {
+                printk(KERN_ERR
+                       "EXT3-fs: fragsize %lu != blocksize %u (unsupported)\n",
+                       sbi->s_frag_size, blocksize);
+                goto failed_mount;
+        }
+        sbi->s_frags_per_block = 1;
+        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
+        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
+        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
+        if (EXT3_INODE_SIZE(sb) == 0)
+                goto cantfind_ext3;
+        sbi->s_inodes_per_block = blocksize / EXT3_INODE_SIZE(sb);
+        if (sbi->s_inodes_per_block == 0)
+                goto cantfind_ext3;
+        sbi->s_itb_per_group = sbi->s_inodes_per_group /
+                                        sbi->s_inodes_per_block;
+        sbi->s_desc_per_block = blocksize / sizeof(struct ext3_group_desc);
+        sbi->s_sbh = bh;
+        sbi->s_mount_state = le16_to_cpu(es->s_state);
+        sbi->s_addr_per_block_bits = log2(EXT3_ADDR_PER_BLOCK(sb));
+        sbi->s_desc_per_block_bits = log2(EXT3_DESC_PER_BLOCK(sb));
+        for (i=0; i < 4; i++)
+                sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
+        sbi->s_def_hash_version = es->s_def_hash_version;
+
+        if (sbi->s_blocks_per_group > blocksize * 8) {
+                printk (KERN_ERR
+                        "EXT3-fs: #blocks per group too big: %lu\n",
+                        sbi->s_blocks_per_group);
+                goto failed_mount;
+        }
+        if (sbi->s_frags_per_group > blocksize * 8) {
+                printk (KERN_ERR
+                        "EXT3-fs: #fragments per group too big: %lu\n",
+                        sbi->s_frags_per_group);
+                goto failed_mount;
+        }
+        if (sbi->s_inodes_per_group > blocksize * 8) {
+                printk (KERN_ERR
+                        "EXT3-fs: #inodes per group too big: %lu\n",
+                        sbi->s_inodes_per_group);
+                goto failed_mount;
+        }
+
+        if (EXT3_BLOCKS_PER_GROUP(sb) == 0)
+                goto cantfind_ext3;
+        sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
+                               le32_to_cpu(es->s_first_data_block) +
+                               EXT3_BLOCKS_PER_GROUP(sb) - 1) /
+                              EXT3_BLOCKS_PER_GROUP(sb);
+        db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
+                   EXT3_DESC_PER_BLOCK(sb);
+        sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
+                                    GFP_KERNEL);
+        if (sbi->s_group_desc == NULL) {
+                printk (KERN_ERR "EXT3-fs: not enough memory\n");
+                goto failed_mount;
+        }
+
+        percpu_counter_init(&sbi->s_freeblocks_counter);
+        percpu_counter_init(&sbi->s_freeinodes_counter);
+        percpu_counter_init(&sbi->s_dirs_counter);
+        bgl_lock_init(&sbi->s_blockgroup_lock);
+
+        for (i = 0; i < db_count; i++) {
+                block = descriptor_loc(sb, logic_sb_block, i);
+                sbi->s_group_desc[i] = sb_bread(sb, block);
+                if (!sbi->s_group_desc[i]) {
+                        printk (KERN_ERR "EXT3-fs: "
+                                "can't read group descriptor %d\n", i);
+                        db_count = i;
+                        goto failed_mount2;
+                }
+        }
+        if (!ext3_check_descriptors (sb)) {
+                printk (KERN_ERR "EXT3-fs: group descriptors corrupted !\n");
+                goto failed_mount2;
+        }
+        sbi->s_gdb_count = db_count;
+        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
+        spin_lock_init(&sbi->s_next_gen_lock);
+        /* per fileystem reservation list head & lock */
+        spin_lock_init(&sbi->s_rsv_window_lock);
+        sbi->s_rsv_window_root = RB_ROOT;
+        /* Add a single, static dummy reservation to the start of the
+         * reservation window list --- it gives us a placeholder for
+         * append-at-start-of-list which makes the allocation logic
+         * _much_ simpler. */
+        sbi->s_rsv_window_head.rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+        sbi->s_rsv_window_head.rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
+        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
+        sbi->s_rsv_window_head.rsv_goal_size = 0;
+        ext3_rsv_window_add(sb, &sbi->s_rsv_window_head);
+
+        /*
+         * set up enough so that it can read an inode
+         */
+        sb->s_op = &ext3_sops;
+        sb->s_export_op = &ext3_export_ops;
+        sb->s_xattr = ext3_xattr_handlers;
+#ifdef CONFIG_QUOTA
+        sb->s_qcop = &ext3_qctl_operations;
+        sb->dq_op = &ext3_quota_operations;
+#endif
+        INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
+
+        sb->s_root = NULL;
+
+        needs_recovery = (es->s_last_orphan != 0 ||
+                          EXT3_HAS_INCOMPAT_FEATURE(sb,
+                                    EXT3_FEATURE_INCOMPAT_RECOVER));
+
+        /*
+         * The first inode we look at is the journal inode.  Don't try
+         * root first: it may be modified in the journal!
+         */
+        if (!test_opt(sb, NOLOAD) &&
+            EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
+                if (ext3_load_journal(sb, es))
+                        goto failed_mount2;
+        } else if (journal_inum) {
+                if (ext3_create_journal(sb, es, journal_inum))
+                        goto failed_mount2;
+        } else {
+                if (!silent)
+                        printk (KERN_ERR
+                                "ext3: No journal on filesystem on %s\n",
+                                sb->s_id);
+                goto failed_mount2;
+        }
+
+        /* We have now updated the journal if required, so we can
+         * validate the data journaling mode. */
+        switch (test_opt(sb, DATA_FLAGS)) {
+        case 0:
+                /* No mode set, assume a default based on the journal
+                   capabilities: ORDERED_DATA if the journal can
+                   cope, else JOURNAL_DATA */
+                if (journal_check_available_features
+                    (sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE))
+                        set_opt(sbi->s_mount_opt, ORDERED_DATA);
+                else
+                        set_opt(sbi->s_mount_opt, JOURNAL_DATA);
+                break;
+
+        case EXT3_MOUNT_ORDERED_DATA:
+        case EXT3_MOUNT_WRITEBACK_DATA:
+                if (!journal_check_available_features
+                    (sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)) {
+                        printk(KERN_ERR "EXT3-fs: Journal does not support "
+                               "requested data journaling mode\n");
+                        goto failed_mount3;
+                }
+        default:
+                break;
+        }
+
+        if (test_opt(sb, NOBH)) {
+                if (sb->s_blocksize_bits != PAGE_CACHE_SHIFT) {
+                        printk(KERN_WARNING "EXT3-fs: Ignoring nobh option "
+                                "since filesystem blocksize doesn't match "
+                                "pagesize\n");
+                        clear_opt(sbi->s_mount_opt, NOBH);
+                }
+                if (!(test_opt(sb, DATA_FLAGS) == EXT3_MOUNT_WRITEBACK_DATA)) {
+                        printk(KERN_WARNING "EXT3-fs: Ignoring nobh option - "
+                                "its supported only with writeback mode\n");
+                        clear_opt(sbi->s_mount_opt, NOBH);
+                }
+        }
+        /*
+         * The journal_load will have done any necessary log recovery,
+         * so we can safely mount the rest of the filesystem now.
+         */
+
+        root = iget(sb, EXT3_ROOT_INO);
+        sb->s_root = d_alloc_root(root);
+        if (!sb->s_root) {
+                printk(KERN_ERR "EXT3-fs: get root inode failed\n");
+                iput(root);
+                goto failed_mount3;
+        }
+        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+                dput(sb->s_root);
+                sb->s_root = NULL;
+                printk(KERN_ERR "EXT3-fs: corrupt root inode, run e2fsck\n");
+                goto failed_mount3;
+        }
+
+        ext3_setup_super (sb, es, sb->s_flags & MS_RDONLY);
+        /*
+         * akpm: core read_super() calls in here with the superblock locked.
+         * That deadlocks, because orphan cleanup needs to lock the superblock
+         * in numerous places.  Here we just pop the lock - it's relatively
+         * harmless, because we are now ready to accept write_super() requests,
+         * and aviro says that's the only reason for hanging onto the
+         * superblock lock.
+         */
+        EXT3_SB(sb)->s_mount_state |= EXT3_ORPHAN_FS;
+        ext3_orphan_cleanup(sb, es);
+        EXT3_SB(sb)->s_mount_state &= ~EXT3_ORPHAN_FS;
+        if (needs_recovery)
+                printk (KERN_INFO "EXT3-fs: recovery complete.\n");
+        ext3_mark_recovery_complete(sb, es);
+        printk (KERN_INFO "EXT3-fs: mounted filesystem with %s data mode.\n",
+                test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ? "journal":
+                test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
+                "writeback");
+
+        percpu_counter_mod(&sbi->s_freeblocks_counter,
+                ext3_count_free_blocks(sb));
+        percpu_counter_mod(&sbi->s_freeinodes_counter,
+                ext3_count_free_inodes(sb));
+        percpu_counter_mod(&sbi->s_dirs_counter,
+                ext3_count_dirs(sb));
+
+        lock_kernel();
+        return 0;
+
+cantfind_ext3:
+        if (!silent)
+                printk(KERN_ERR "VFS: Can't find ext3 filesystem on dev %s.\n",
+                       sb->s_id);
+        goto failed_mount;
+
+failed_mount3:
+        journal_destroy(sbi->s_journal);
+failed_mount2:
+        for (i = 0; i < db_count; i++)
+                brelse(sbi->s_group_desc[i]);
+        kfree(sbi->s_group_desc);
+failed_mount:
+#ifdef CONFIG_QUOTA
+        for (i = 0; i < MAXQUOTAS; i++)
+                kfree(sbi->s_qf_names[i]);
+#endif
+        ext3_blkdev_remove(sbi);
+        brelse(bh);
+out_fail:
+        sb->s_fs_info = NULL;
+        kfree(sbi);
+        lock_kernel();
+        return -EINVAL;
+}
+
+/*
+ * Setup any per-fs journal parameters now.  We'll do this both on
+ * initial mount, once the journal has been initialised but before we've
+ * done any recovery; and again on any subsequent remount. 
+ */
+static void ext3_init_journal_params(struct super_block *sb, journal_t *journal)
+{
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+
+        if (sbi->s_commit_interval)
+                journal->j_commit_interval = sbi->s_commit_interval;
+        /* We could also set up an ext3-specific default for the commit
+         * interval here, but for now we'll just fall back to the jbd
+         * default. */
+
+        spin_lock(&journal->j_state_lock);
+        if (test_opt(sb, BARRIER))
+                journal->j_flags |= JFS_BARRIER;
+        else
+                journal->j_flags &= ~JFS_BARRIER;
+        spin_unlock(&journal->j_state_lock);
+}
+
+static journal_t *ext3_get_journal(struct super_block *sb, int journal_inum)
+{
+        struct inode *journal_inode;
+        journal_t *journal;
+
+        /* First, test for the existence of a valid inode on disk.  Bad
+         * things happen if we iget() an unused inode, as the subsequent
+         * iput() will try to delete it. */
+
+        journal_inode = iget(sb, journal_inum);
+        if (!journal_inode) {
+                printk(KERN_ERR "EXT3-fs: no journal found.\n");
+                return NULL;
+        }
+        if (!journal_inode->i_nlink) {
+                make_bad_inode(journal_inode);
+                iput(journal_inode);
+                printk(KERN_ERR "EXT3-fs: journal inode is deleted.\n");
+                return NULL;
+        }
+
+        jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
+                  journal_inode, journal_inode->i_size);
+        if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
+                printk(KERN_ERR "EXT3-fs: invalid journal inode.\n");
+                iput(journal_inode);
+                return NULL;
+        }
+
+        journal = journal_init_inode(journal_inode);
+        if (!journal) {
+                printk(KERN_ERR "EXT3-fs: Could not load journal inode\n");
+                iput(journal_inode);
+                return NULL;
+        }
+        journal->j_private = sb;
+        ext3_init_journal_params(sb, journal);
+        return journal;
+}
+
+static journal_t *ext3_get_dev_journal(struct super_block *sb,
+                                       dev_t j_dev)
+{
+        struct buffer_head * bh;
+        journal_t *journal;
+        int start;
+        int len;
+        int hblock, blocksize;
+        unsigned long sb_block;
+        unsigned long offset;
+        struct ext3_super_block * es;
+        struct block_device *bdev;
+
+        bdev = ext3_blkdev_get(j_dev);
+        if (bdev == NULL)
+                return NULL;
+
+        if (bd_claim(bdev, sb)) {
+                printk(KERN_ERR
+                        "EXT3: failed to claim external journal device.\n");
+                blkdev_put(bdev);
+                return NULL;
+        }
+
+        blocksize = sb->s_blocksize;
+        hblock = bdev_hardsect_size(bdev);
+        if (blocksize < hblock) {
+                printk(KERN_ERR
+                        "EXT3-fs: blocksize too small for journal device.\n");
+                goto out_bdev;
+        }
+
+        sb_block = EXT3_MIN_BLOCK_SIZE / blocksize;
+        offset = EXT3_MIN_BLOCK_SIZE % blocksize;
+        set_blocksize(bdev, blocksize);
+        if (!(bh = __bread(bdev, sb_block, blocksize))) {
+                printk(KERN_ERR "EXT3-fs: couldn't read superblock of "
+                       "external journal\n");
+                goto out_bdev;
+        }
+
+        es = (struct ext3_super_block *) (((char *)bh->b_data) + offset);
+        if ((le16_to_cpu(es->s_magic) != EXT3_SUPER_MAGIC) ||
+            !(le32_to_cpu(es->s_feature_incompat) &
+              EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) {
+                printk(KERN_ERR "EXT3-fs: external journal has "
+                                        "bad superblock\n");
+                brelse(bh);
+                goto out_bdev;
+        }
+
+        if (memcmp(EXT3_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
+                printk(KERN_ERR "EXT3-fs: journal UUID does not match\n");
+                brelse(bh);
+                goto out_bdev;
+        }
+
+        len = le32_to_cpu(es->s_blocks_count);
+        start = sb_block + 1;
+        brelse(bh);     /* we're done with the superblock */
+
+        journal = journal_init_dev(bdev, sb->s_bdev,
+                                        start, len, blocksize);
+        if (!journal) {
+                printk(KERN_ERR "EXT3-fs: failed to create device journal\n");
+                goto out_bdev;
+        }
+        journal->j_private = sb;
+        ll_rw_block(READ, 1, &journal->j_sb_buffer);
+        wait_on_buffer(journal->j_sb_buffer);
+        if (!buffer_uptodate(journal->j_sb_buffer)) {
+                printk(KERN_ERR "EXT3-fs: I/O error on journal device\n");
+                goto out_journal;
+        }
+        if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
+                printk(KERN_ERR "EXT3-fs: External journal has more than one "
+                                        "user (unsupported) - %d\n",
+                        be32_to_cpu(journal->j_superblock->s_nr_users));
+                goto out_journal;
+        }
+        EXT3_SB(sb)->journal_bdev = bdev;
+        ext3_init_journal_params(sb, journal);
+        return journal;
+out_journal:
+        journal_destroy(journal);
+out_bdev:
+        ext3_blkdev_put(bdev);
+        return NULL;
+}
+
+static int ext3_load_journal(struct super_block * sb,
+                             struct ext3_super_block * es)
+{
+        journal_t *journal;
+        int journal_inum = le32_to_cpu(es->s_journal_inum);
+        dev_t journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
+        int err = 0;
+        int really_read_only;
+
+        really_read_only = bdev_read_only(sb->s_bdev);
+
+        /*
+         * Are we loading a blank journal or performing recovery after a
+         * crash?  For recovery, we need to check in advance whether we
+         * can get read-write access to the device.
+         */
+
+        if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER)) {
+                if (sb->s_flags & MS_RDONLY) {
+                        printk(KERN_INFO "EXT3-fs: INFO: recovery "
+                                        "required on readonly filesystem.\n");
+                        if (really_read_only) {
+                                printk(KERN_ERR "EXT3-fs: write access "
+                                        "unavailable, cannot proceed.\n");
+                                return -EROFS;
+                        }
+                        printk (KERN_INFO "EXT3-fs: write access will "
+                                        "be enabled during recovery.\n");
+                }
+        }
+
+        if (journal_inum && journal_dev) {
+                printk(KERN_ERR "EXT3-fs: filesystem has both journal "
+                       "and inode journals!\n");
+                return -EINVAL;
+        }
+
+        if (journal_inum) {
+                if (!(journal = ext3_get_journal(sb, journal_inum)))
+                        return -EINVAL;
+        } else {
+                if (!(journal = ext3_get_dev_journal(sb, journal_dev)))
+                        return -EINVAL;
+        }
+
+        if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
+                err = journal_update_format(journal);
+                if (err)  {
+                        printk(KERN_ERR "EXT3-fs: error updating journal.\n");
+                        journal_destroy(journal);
+                        return err;
+                }
+        }
+
+        if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER))
+                err = journal_wipe(journal, !really_read_only);
+        if (!err)
+                err = journal_load(journal);
+
+        if (err) {
+                printk(KERN_ERR "EXT3-fs: error loading journal.\n");
+                journal_destroy(journal);
+                return err;
+        }
+
+        EXT3_SB(sb)->s_journal = journal;
+        ext3_clear_journal_err(sb, es);
+        return 0;
+}
+
+static int ext3_create_journal(struct super_block * sb,
+                               struct ext3_super_block * es,
+                               int journal_inum)
+{
+        journal_t *journal;
+
+        if (sb->s_flags & MS_RDONLY) {
+                printk(KERN_ERR "EXT3-fs: readonly filesystem when trying to "
+                                "create journal.\n");
+                return -EROFS;
+        }
+
+        if (!(journal = ext3_get_journal(sb, journal_inum)))
+                return -EINVAL;
+
+        printk(KERN_INFO "EXT3-fs: creating new journal on inode %d\n",
+               journal_inum);
+
+        if (journal_create(journal)) {
+                printk(KERN_ERR "EXT3-fs: error creating journal.\n");
+                journal_destroy(journal);
+                return -EIO;
+        }
+
+        EXT3_SB(sb)->s_journal = journal;
+
+        ext3_update_dynamic_rev(sb);
+        EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+        EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL);
+
+        es->s_journal_inum = cpu_to_le32(journal_inum);
+        sb->s_dirt = 1;
+
+        /* Make sure we flush the recovery flag to disk. */
+        ext3_commit_super(sb, es, 1);
+
+        return 0;
+}
+
+static void ext3_commit_super (struct super_block * sb,
+                               struct ext3_super_block * es,
+                               int sync)
+{
+        struct buffer_head *sbh = EXT3_SB(sb)->s_sbh;
+
+        if (!sbh)
+                return;
+        es->s_wtime = cpu_to_le32(get_seconds());
+        es->s_free_blocks_count = cpu_to_le32(ext3_count_free_blocks(sb));
+        es->s_free_inodes_count = cpu_to_le32(ext3_count_free_inodes(sb));
+        BUFFER_TRACE(sbh, "marking dirty");
+        mark_buffer_dirty(sbh);
+        if (sync)
+                sync_dirty_buffer(sbh);
+}
+
+
+/*
+ * Have we just finished recovery?  If so, and if we are mounting (or
+ * remounting) the filesystem readonly, then we will end up with a
+ * consistent fs on disk.  Record that fact.
+ */
+static void ext3_mark_recovery_complete(struct super_block * sb,
+                                        struct ext3_super_block * es)
+{
+        journal_t *journal = EXT3_SB(sb)->s_journal;
+
+        journal_lock_updates(journal);
+        journal_flush(journal);
+        if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER) &&
+            sb->s_flags & MS_RDONLY) {
+                EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+                sb->s_dirt = 0;
+                ext3_commit_super(sb, es, 1);
+        }
+        journal_unlock_updates(journal);
+}
+
+/*
+ * If we are mounting (or read-write remounting) a filesystem whose journal
+ * has recorded an error from a previous lifetime, move that error to the
+ * main filesystem now.
+ */
+static void ext3_clear_journal_err(struct super_block * sb,
+                                   struct ext3_super_block * es)
+{
+        journal_t *journal;
+        int j_errno;
+        const char *errstr;
+
+        journal = EXT3_SB(sb)->s_journal;
+
+        /*
+         * Now check for any error status which may have been recorded in the
+         * journal by a prior ext3_error() or ext3_abort()
+         */
+
+        j_errno = journal_errno(journal);
+        if (j_errno) {
+                char nbuf[16];
+
+                errstr = ext3_decode_error(sb, j_errno, nbuf);
+                ext3_warning(sb, __FUNCTION__, "Filesystem error recorded "
+                             "from previous mount: %s", errstr);
+                ext3_warning(sb, __FUNCTION__, "Marking fs in need of "
+                             "filesystem check.");
+
+                EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
+                es->s_state |= cpu_to_le16(EXT3_ERROR_FS);
+                ext3_commit_super (sb, es, 1);
+
+                journal_clear_err(journal);
+        }
+}
+
+/*
+ * Force the running and committing transactions to commit,
+ * and wait on the commit.
+ */
+int ext3_force_commit(struct super_block *sb)
+{
+        journal_t *journal;
+        int ret;
+
+        if (sb->s_flags & MS_RDONLY)
+                return 0;
+
+        journal = EXT3_SB(sb)->s_journal;
+        sb->s_dirt = 0;
+        ret = ext3_journal_force_commit(journal);
+        return ret;
+}
+
+/*
+ * Ext3 always journals updates to the superblock itself, so we don't
+ * have to propagate any other updates to the superblock on disk at this
+ * point.  Just start an async writeback to get the buffers on their way
+ * to the disk.
+ *
+ * This implicitly triggers the writebehind on sync().
+ */
+
+static void ext3_write_super (struct super_block * sb)
+{
+        if (down_trylock(&sb->s_lock) == 0)
+                BUG();
+        sb->s_dirt = 0;
+}
+
+static int ext3_sync_fs(struct super_block *sb, int wait)
+{
+        tid_t target;
+
+        sb->s_dirt = 0;
+        if (journal_start_commit(EXT3_SB(sb)->s_journal, &target)) {
+                if (wait)
+                        log_wait_commit(EXT3_SB(sb)->s_journal, target);
+        }
+        return 0;
+}
+
+/*
+ * LVM calls this function before a (read-only) snapshot is created.  This
+ * gives us a chance to flush the journal completely and mark the fs clean.
+ */
+static void ext3_write_super_lockfs(struct super_block *sb)
+{
+        sb->s_dirt = 0;
+
+        if (!(sb->s_flags & MS_RDONLY)) {
+                journal_t *journal = EXT3_SB(sb)->s_journal;
+
+                /* Now we set up the journal barrier. */
+                journal_lock_updates(journal);
+                journal_flush(journal);
+
+                /* Journal blocked and flushed, clear needs_recovery flag. */
+                EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+                ext3_commit_super(sb, EXT3_SB(sb)->s_es, 1);
+        }
+}
+
+/*
+ * Called by LVM after the snapshot is done.  We need to reset the RECOVER
+ * flag here, even though the filesystem is not technically dirty yet.
+ */
+static void ext3_unlockfs(struct super_block *sb)
+{
+        if (!(sb->s_flags & MS_RDONLY)) {
+                lock_super(sb);
+                /* Reser the needs_recovery flag before the fs is unlocked. */
+                EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+                ext3_commit_super(sb, EXT3_SB(sb)->s_es, 1);
+                unlock_super(sb);
+                journal_unlock_updates(EXT3_SB(sb)->s_journal);
+        }
+}
+
+static int ext3_remount (struct super_block * sb, int * flags, char * data)
+{
+        struct ext3_super_block * es;
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        unsigned long tmp;
+        unsigned long n_blocks_count = 0;
+
+        /*
+         * Allow the "check" option to be passed as a remount option.
+         */
+        if (!parse_options(data, sb, &tmp, &n_blocks_count, 1))
+                return -EINVAL;
+
+        if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
+                ext3_abort(sb, __FUNCTION__, "Abort forced by user");
+
+        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+                ((sbi->s_mount_opt & EXT3_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
+
+        es = sbi->s_es;
+
+        ext3_init_journal_params(sb, sbi->s_journal);
+
+        if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
+                n_blocks_count > le32_to_cpu(es->s_blocks_count)) {
+                if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
+                        return -EROFS;
+
+                if (*flags & MS_RDONLY) {
+                        /*
+                         * First of all, the unconditional stuff we have to do
+                         * to disable replay of the journal when we next remount
+                         */
+                        sb->s_flags |= MS_RDONLY;
+
+                        /*
+                         * OK, test if we are remounting a valid rw partition
+                         * readonly, and if so set the rdonly flag and then
+                         * mark the partition as valid again.
+                         */
+                        if (!(es->s_state & cpu_to_le16(EXT3_VALID_FS)) &&
+                            (sbi->s_mount_state & EXT3_VALID_FS))
+                                es->s_state = cpu_to_le16(sbi->s_mount_state);
+
+                        ext3_mark_recovery_complete(sb, es);
+                } else {
+                        __le32 ret;
+                        if ((ret = EXT3_HAS_RO_COMPAT_FEATURE(sb,
+                                        ~EXT3_FEATURE_RO_COMPAT_SUPP))) {
+                                printk(KERN_WARNING "EXT3-fs: %s: couldn't "
+                                       "remount RDWR because of unsupported "
+                                       "optional features (%x).\n",
+                                       sb->s_id, le32_to_cpu(ret));
+                                return -EROFS;
+                        }
+                        /*
+                         * Mounting a RDONLY partition read-write, so reread
+                         * and store the current valid flag.  (It may have
+                         * been changed by e2fsck since we originally mounted
+                         * the partition.)
+                         */
+                        ext3_clear_journal_err(sb, es);
+                        sbi->s_mount_state = le16_to_cpu(es->s_state);
+                        if ((ret = ext3_group_extend(sb, es, n_blocks_count)))
+                                return ret;
+                        if (!ext3_setup_super (sb, es, 0))
+                                sb->s_flags &= ~MS_RDONLY;
+                }
+        }
+        return 0;
+}
+
+static int ext3_statfs (struct super_block * sb, struct kstatfs * buf)
+{
+        struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+        unsigned long overhead;
+        int i;
+
+        if (test_opt (sb, MINIX_DF))
+                overhead = 0;
+        else {
+                unsigned long ngroups;
+                ngroups = EXT3_SB(sb)->s_groups_count;
+                smp_rmb();
+
+                /*
+                 * Compute the overhead (FS structures)
+                 */
+
+                /*
+                 * All of the blocks before first_data_block are
+                 * overhead
+                 */
+                overhead = le32_to_cpu(es->s_first_data_block);
+
+                /*
+                 * Add the overhead attributed to the superblock and
+                 * block group descriptors.  If the sparse superblocks
+                 * feature is turned on, then not all groups have this.
+                 */
+                for (i = 0; i < ngroups; i++) {
+                        overhead += ext3_bg_has_super(sb, i) +
+                                ext3_bg_num_gdb(sb, i);
+                        cond_resched();
+                }
+
+                /*
+                 * Every block group has an inode bitmap, a block
+                 * bitmap, and an inode table.
+                 */
+                overhead += (ngroups * (2 + EXT3_SB(sb)->s_itb_per_group));
+        }
+
+        buf->f_type = EXT3_SUPER_MAGIC;
+        buf->f_bsize = sb->s_blocksize;
+        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;
+        buf->f_bfree = ext3_count_free_blocks (sb);
+        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
+        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
+                buf->f_bavail = 0;
+        buf->f_files = le32_to_cpu(es->s_inodes_count);
+        buf->f_ffree = ext3_count_free_inodes (sb);
+        buf->f_namelen = EXT3_NAME_LEN;
+        return 0;
+}
+
+/* Helper function for writing quotas on sync - we need to start transaction before quota file
+ * is locked for write. Otherwise the are possible deadlocks:
+ * Process 1                         Process 2
+ * ext3_create()                     quota_sync()
+ *   journal_start()                   write_dquot()
+ *   DQUOT_INIT()                        down(dqio_sem)
+ *     down(dqio_sem)                    journal_start()
+ *
+ */
+
+#ifdef CONFIG_QUOTA
+
+static inline struct inode *dquot_to_inode(struct dquot *dquot)
+{
+        return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
+}
+
+static int ext3_dquot_initialize(struct inode *inode, int type)
+{
+        handle_t *handle;
+        int ret, err;
+
+        /* We may create quota structure so we need to reserve enough blocks */
+        handle = ext3_journal_start(inode, 2*EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        ret = dquot_initialize(inode, type);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+static int ext3_dquot_drop(struct inode *inode)
+{
+        handle_t *handle;
+        int ret, err;
+
+        /* We may delete quota structure so we need to reserve enough blocks */
+        handle = ext3_journal_start(inode, 2*EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        ret = dquot_drop(inode);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+static int ext3_write_dquot(struct dquot *dquot)
+{
+        int ret, err;
+        handle_t *handle;
+        struct inode *inode;
+
+        inode = dquot_to_inode(dquot);
+        handle = ext3_journal_start(inode,
+                                        EXT3_QUOTA_TRANS_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        ret = dquot_commit(dquot);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+static int ext3_acquire_dquot(struct dquot *dquot)
+{
+        int ret, err;
+        handle_t *handle;
+
+        handle = ext3_journal_start(dquot_to_inode(dquot),
+                                        EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        ret = dquot_acquire(dquot);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+static int ext3_release_dquot(struct dquot *dquot)
+{
+        int ret, err;
+        handle_t *handle;
+
+        handle = ext3_journal_start(dquot_to_inode(dquot),
+                                        EXT3_QUOTA_INIT_BLOCKS);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        ret = dquot_release(dquot);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+static int ext3_mark_dquot_dirty(struct dquot *dquot)
+{
+        /* Are we journalling quotas? */
+        if (EXT3_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
+            EXT3_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
+                dquot_mark_dquot_dirty(dquot);
+                return ext3_write_dquot(dquot);
+        } else {
+                return dquot_mark_dquot_dirty(dquot);
+        }
+}
+
+static int ext3_write_info(struct super_block *sb, int type)
+{
+        int ret, err;
+        handle_t *handle;
+
+        /* Data block + inode block */
+        handle = ext3_journal_start(sb->s_root->d_inode, 2);
+        if (IS_ERR(handle))
+                return PTR_ERR(handle);
+        ret = dquot_commit_info(sb, type);
+        err = ext3_journal_stop(handle);
+        if (!ret)
+                ret = err;
+        return ret;
+}
+
+/*
+ * Turn on quotas during mount time - we need to find
+ * the quota file and such...
+ */
+static int ext3_quota_on_mount(struct super_block *sb, int type)
+{
+        int err;
+        struct dentry *dentry;
+        struct qstr name = { .name = EXT3_SB(sb)->s_qf_names[type],
+                             .hash = 0,
+                             .len = strlen(EXT3_SB(sb)->s_qf_names[type])};
+
+        dentry = lookup_hash(&name, sb->s_root);
+        if (IS_ERR(dentry))
+                return PTR_ERR(dentry);
+        err = vfs_quota_on_mount(type, EXT3_SB(sb)->s_jquota_fmt, dentry);
+        /* Now invalidate and put the dentry - quota got its own reference
+         * to inode and dentry has at least wrong hash so we had better
+         * throw it away */
+        d_invalidate(dentry);
+        dput(dentry);
+        return err;
+}
+
+/*
+ * Standard function to be called on quota_on
+ */
+static int ext3_quota_on(struct super_block *sb, int type, int format_id,
+                         char *path)
+{
+        int err;
+        struct nameidata nd;
+
+        /* Not journalling quota? */
+        if (!EXT3_SB(sb)->s_qf_names[USRQUOTA] &&
+            !EXT3_SB(sb)->s_qf_names[GRPQUOTA])
+                return vfs_quota_on(sb, type, format_id, path);
+        err = path_lookup(path, LOOKUP_FOLLOW, &nd);
+        if (err)
+                return err;
+        /* Quotafile not on the same filesystem? */
+        if (nd.mnt->mnt_sb != sb) {
+                path_release(&nd);
+                return -EXDEV;
+        }
+        /* Quotafile not of fs root? */
+        if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
+                printk(KERN_WARNING
+                        "EXT3-fs: Quota file not on filesystem root. "
+                        "Journalled quota will not work.\n");
+        path_release(&nd);
+        return vfs_quota_on(sb, type, format_id, path);
+}
+
+/* Read data from quotafile - avoid pagecache and such because we cannot afford
+ * acquiring the locks... As quota files are never truncated and quota code
+ * itself serializes the operations (and noone else should touch the files)
+ * we don't have to be afraid of races */
+static ssize_t ext3_quota_read(struct super_block *sb, int type, char *data,
+                               size_t len, loff_t off)
+{
+        struct inode *inode = sb_dqopt(sb)->files[type];
+        sector_t blk = off >> EXT3_BLOCK_SIZE_BITS(sb);
+        int err = 0;
+        int offset = off & (sb->s_blocksize - 1);
+        int tocopy;
+        size_t toread;
+        struct buffer_head *bh;
+        loff_t i_size = i_size_read(inode);
+
+        if (off > i_size)
+                return 0;
+        if (off+len > i_size)
+                len = i_size-off;
+        toread = len;
+        while (toread > 0) {
+                tocopy = sb->s_blocksize - offset < toread ?
+                                sb->s_blocksize - offset : toread;
+                bh = ext3_bread(NULL, inode, blk, 0, &err);
+                if (err)
+                        return err;
+                if (!bh)        /* A hole? */
+                        memset(data, 0, tocopy);
+                else
+                        memcpy(data, bh->b_data+offset, tocopy);
+                brelse(bh);
+                offset = 0;
+                toread -= tocopy;
+                data += tocopy;
+                blk++;
+        }
+        return len;
+}
+
+/* Write to quotafile (we know the transaction is already started and has
+ * enough credits) */
+static ssize_t ext3_quota_write(struct super_block *sb, int type,
+                                const char *data, size_t len, loff_t off)
+{
+        struct inode *inode = sb_dqopt(sb)->files[type];
+        sector_t blk = off >> EXT3_BLOCK_SIZE_BITS(sb);
+        int err = 0;
+        int offset = off & (sb->s_blocksize - 1);
+        int tocopy;
+        int journal_quota = EXT3_SB(sb)->s_qf_names[type] != NULL;
+        size_t towrite = len;
+        struct buffer_head *bh;
+        handle_t *handle = journal_current_handle();
+
+        down(&inode->i_sem);
+        while (towrite > 0) {
+                tocopy = sb->s_blocksize - offset < towrite ?
+                                sb->s_blocksize - offset : towrite;
+                bh = ext3_bread(handle, inode, blk, 1, &err);
+                if (!bh)
+                        goto out;
+                if (journal_quota) {
+                        err = ext3_journal_get_write_access(handle, bh);
+                        if (err) {
+                                brelse(bh);
+                                goto out;
+                        }
+                }
+                lock_buffer(bh);
+                memcpy(bh->b_data+offset, data, tocopy);
+                flush_dcache_page(bh->b_page);
+                unlock_buffer(bh);
+                if (journal_quota)
+                        err = ext3_journal_dirty_metadata(handle, bh);
+                else {
+                        /* Always do at least ordered writes for quotas */
+                        err = ext3_journal_dirty_data(handle, bh);
+                        mark_buffer_dirty(bh);
+                }
+                brelse(bh);
+                if (err)
+                        goto out;
+                offset = 0;
+                towrite -= tocopy;
+                data += tocopy;
+                blk++;
+        }
+out:
+        if (len == towrite)
+                return err;
+        if (inode->i_size < off+len-towrite) {
+                i_size_write(inode, off+len-towrite);
+                EXT3_I(inode)->i_disksize = inode->i_size;
+        }
+        inode->i_version++;
+        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+        ext3_mark_inode_dirty(handle, inode);
+        up(&inode->i_sem);
+        return len - towrite;
+}
+
+#endif
+
+static struct super_block *ext3_get_sb(struct file_system_type *fs_type,
+        int flags, const char *dev_name, void *data)
+{
+        return get_sb_bdev(fs_type, flags, dev_name, data, ext3_fill_super);
+}
+
+static struct file_system_type ext3_fs_type = {
+        .owner          = THIS_MODULE,
+        .name           = "ext3",
+        .get_sb         = ext3_get_sb,
+        .kill_sb        = kill_block_super,
+        .fs_flags       = FS_REQUIRES_DEV,
+};
+
+static int __init init_ext3_fs(void)
+{
+        int err = init_ext3_xattr();
+        if (err)
+                return err;
+        err = init_inodecache();
+        if (err)
+                goto out1;
+        err = register_filesystem(&ext3_fs_type);
+        if (err)
+                goto out;
+        return 0;
+out:
+        destroy_inodecache();
+out1:
+        exit_ext3_xattr();
+        return err;
+}
+
+static void __exit exit_ext3_fs(void)
+{
+        unregister_filesystem(&ext3_fs_type);
+        destroy_inodecache();
+        exit_ext3_xattr();
+}
+
+MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
+MODULE_DESCRIPTION("Second Extended Filesystem with journaling extensions");
+MODULE_LICENSE("GPL");
+module_init(init_ext3_fs)
+module_exit(exit_ext3_fs)
diff --git a/fs/ext3/symlink.c b/fs/ext3/symlink.c
new file mode 100644
index 000000000000..8c3e72818fb0
--- /dev/null
+++ b/fs/ext3/symlink.c
@@ -0,0 +1,54 @@
+/*
+ *  linux/fs/ext3/symlink.c
+ *
+ * Only fast symlinks left here - the rest is done by generic code. AV, 1999
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/symlink.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3 symlink handling code
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/namei.h>
+#include "xattr.h"
+
+static int ext3_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+        struct ext3_inode_info *ei = EXT3_I(dentry->d_inode);
+        nd_set_link(nd, (char*)ei->i_data);
+        return 0;
+}
+
+struct inode_operations ext3_symlink_inode_operations = {
+        .readlink       = generic_readlink,
+        .follow_link    = page_follow_link_light,
+        .put_link       = page_put_link,
+#ifdef CONFIG_EXT3_FS_XATTR
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
+        .listxattr      = ext3_listxattr,
+        .removexattr    = generic_removexattr,
+#endif
+};
+
+struct inode_operations ext3_fast_symlink_inode_operations = {
+        .readlink       = generic_readlink,
+        .follow_link    = ext3_follow_link,
+#ifdef CONFIG_EXT3_FS_XATTR
+        .setxattr       = generic_setxattr,
+        .getxattr       = generic_getxattr,
+        .listxattr      = ext3_listxattr,
+        .removexattr    = generic_removexattr,
+#endif
+};
diff --git a/fs/ext3/xattr.c b/fs/ext3/xattr.c
new file mode 100644
index 000000000000..4cbc6d0212d3
--- /dev/null
+++ b/fs/ext3/xattr.c
@@ -0,0 +1,1320 @@
+/*
+ * linux/fs/ext3/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Ext3 code with a lot of help from Eric Jarman <ejarman@acm.org>.
+ * Extended attributes for symlinks and special files added per
+ *  suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ *  Red Hat Inc.
+ * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
+ *  and Andreas Gruenbacher <agruen@suse.de>.
+ */
+
+/*
+ * Extended attributes are stored directly in inodes (on file systems with
+ * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
+ * field contains the block number if an inode uses an additional block. All
+ * attributes must fit in the inode and one additional block. Blocks that
+ * contain the identical set of attributes may be shared among several inodes.
+ * Identical blocks are detected by keeping a cache of blocks that have
+ * recently been accessed.
+ *
+ * The attributes in inodes and on blocks have a different header; the entries
+ * are stored in the same format:
+ *
+ *   +------------------+
+ *   | header           |
+ *   | entry 1          | |
+ *   | entry 2          | | growing downwards
+ *   | entry 3          | v
+ *   | four null bytes  |
+ *   | . . .            |
+ *   | value 1          | ^
+ *   | value 3          | | growing upwards
+ *   | value 2          | |
+ *   +------------------+
+ *
+ * The header is followed by multiple entry descriptors. In disk blocks, the
+ * entry descriptors are kept sorted. In inodes, they are unsorted. The
+ * attribute values are aligned to the end of the block in no specific order.
+ *
+ * Locking strategy
+ * ----------------
+ * EXT3_I(inode)->i_file_acl is protected by EXT3_I(inode)->xattr_sem.
+ * EA blocks are only changed if they are exclusive to an inode, so
+ * holding xattr_sem also means that nothing but the EA block's reference
+ * count can change. Multiple writers to the same block are synchronized
+ * by the buffer lock.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/mbcache.h>
+#include <linux/quotaops.h>
+#include <linux/rwsem.h>
+#include "xattr.h"
+#include "acl.h"
+
+#define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
+#define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
+#define BFIRST(bh) ENTRY(BHDR(bh)+1)
+#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#define IHDR(inode, raw_inode) \
+        ((struct ext3_xattr_ibody_header *) \
+                ((void *)raw_inode + \
+                 EXT3_GOOD_OLD_INODE_SIZE + \
+                 EXT3_I(inode)->i_extra_isize))
+#define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
+
+#ifdef EXT3_XATTR_DEBUG
+# define ea_idebug(inode, f...) do { \
+                printk(KERN_DEBUG "inode %s:%ld: ", \
+                        inode->i_sb->s_id, inode->i_ino); \
+                printk(f); \
+                printk("\n"); \
+        } while (0)
+# define ea_bdebug(bh, f...) do { \
+                char b[BDEVNAME_SIZE]; \
+                printk(KERN_DEBUG "block %s:%lu: ", \
+                        bdevname(bh->b_bdev, b), \
+                        (unsigned long) bh->b_blocknr); \
+                printk(f); \
+                printk("\n"); \
+        } while (0)
+#else
+# define ea_idebug(f...)
+# define ea_bdebug(f...)
+#endif
+
+static void ext3_xattr_cache_insert(struct buffer_head *);
+static struct buffer_head *ext3_xattr_cache_find(struct inode *,
+                                                 struct ext3_xattr_header *,
+                                                 struct mb_cache_entry **);
+static void ext3_xattr_rehash(struct ext3_xattr_header *,
+                              struct ext3_xattr_entry *);
+
+static struct mb_cache *ext3_xattr_cache;
+
+static struct xattr_handler *ext3_xattr_handler_map[] = {
+        [EXT3_XATTR_INDEX_USER]              = &ext3_xattr_user_handler,
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+        [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS]  = &ext3_xattr_acl_access_handler,
+        [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext3_xattr_acl_default_handler,
+#endif
+        [EXT3_XATTR_INDEX_TRUSTED]           = &ext3_xattr_trusted_handler,
+#ifdef CONFIG_EXT3_FS_SECURITY
+        [EXT3_XATTR_INDEX_SECURITY]          = &ext3_xattr_security_handler,
+#endif
+};
+
+struct xattr_handler *ext3_xattr_handlers[] = {
+        &ext3_xattr_user_handler,
+        &ext3_xattr_trusted_handler,
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+        &ext3_xattr_acl_access_handler,
+        &ext3_xattr_acl_default_handler,
+#endif
+#ifdef CONFIG_EXT3_FS_SECURITY
+        &ext3_xattr_security_handler,
+#endif
+        NULL
+};
+
+static inline struct xattr_handler *
+ext3_xattr_handler(int name_index)
+{
+        struct xattr_handler *handler = NULL;
+
+        if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map))
+                handler = ext3_xattr_handler_map[name_index];
+        return handler;
+}
+
+/*
+ * Inode operation listxattr()
+ *
+ * dentry->d_inode->i_sem: don't care
+ */
+ssize_t
+ext3_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+        return ext3_xattr_list(dentry->d_inode, buffer, size);
+}
+
+static int
+ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end)
+{
+        while (!IS_LAST_ENTRY(entry)) {
+                struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry);
+                if ((void *)next >= end)
+                        return -EIO;
+                entry = next;
+        }
+        return 0;
+}
+
+static inline int
+ext3_xattr_check_block(struct buffer_head *bh)
+{
+        int error;
+
+        if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
+            BHDR(bh)->h_blocks != cpu_to_le32(1))
+                return -EIO;
+        error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
+        return error;
+}
+
+static inline int
+ext3_xattr_check_entry(struct ext3_xattr_entry *entry, size_t size)
+{
+        size_t value_size = le32_to_cpu(entry->e_value_size);
+
+        if (entry->e_value_block != 0 || value_size > size ||
+            le16_to_cpu(entry->e_value_offs) + value_size > size)
+                return -EIO;
+        return 0;
+}
+
+static int
+ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index,
+                      const char *name, size_t size, int sorted)
+{
+        struct ext3_xattr_entry *entry;
+        size_t name_len;
+        int cmp = 1;
+
+        if (name == NULL)
+                return -EINVAL;
+        name_len = strlen(name);
+        entry = *pentry;
+        for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
+                cmp = name_index - entry->e_name_index;
+                if (!cmp)
+                        cmp = name_len - entry->e_name_len;
+                if (!cmp)
+                        cmp = memcmp(name, entry->e_name, name_len);
+                if (cmp <= 0 && (sorted || cmp == 0))
+                        break;
+        }
+        *pentry = entry;
+        if (!cmp && ext3_xattr_check_entry(entry, size))
+                        return -EIO;
+        return cmp ? -ENODATA : 0;
+}
+
+int
+ext3_xattr_block_get(struct inode *inode, int name_index, const char *name,
+                     void *buffer, size_t buffer_size)
+{
+        struct buffer_head *bh = NULL;
+        struct ext3_xattr_entry *entry;
+        size_t size;
+        int error;
+
+        ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
+                  name_index, name, buffer, (long)buffer_size);
+
+        error = -ENODATA;
+        if (!EXT3_I(inode)->i_file_acl)
+                goto cleanup;
+        ea_idebug(inode, "reading block %d", EXT3_I(inode)->i_file_acl);
+        bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
+        if (!bh)
+                goto cleanup;
+        ea_bdebug(bh, "b_count=%d, refcount=%d",
+                atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
+        if (ext3_xattr_check_block(bh)) {
+bad_block:      ext3_error(inode->i_sb, __FUNCTION__,
+                           "inode %ld: bad block %d", inode->i_ino,
+                           EXT3_I(inode)->i_file_acl);
+                error = -EIO;
+                goto cleanup;
+        }
+        ext3_xattr_cache_insert(bh);
+        entry = BFIRST(bh);
+        error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
+        if (error == -EIO)
+                goto bad_block;
+        if (error)
+                goto cleanup;
+        size = le32_to_cpu(entry->e_value_size);
+        if (buffer) {
+                error = -ERANGE;
+                if (size > buffer_size)
+                        goto cleanup;
+                memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
+                       size);
+        }
+        error = size;
+
+cleanup:
+        brelse(bh);
+        return error;
+}
+
+static int
+ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
+                     void *buffer, size_t buffer_size)
+{
+        struct ext3_xattr_ibody_header *header;
+        struct ext3_xattr_entry *entry;
+        struct ext3_inode *raw_inode;
+        struct ext3_iloc iloc;
+        size_t size;
+        void *end;
+        int error;
+
+        if (!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR))
+                return -ENODATA;
+        error = ext3_get_inode_loc(inode, &iloc);
+        if (error)
+                return error;
+        raw_inode = ext3_raw_inode(&iloc);
+        header = IHDR(inode, raw_inode);
+        entry = IFIRST(header);
+        end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
+        error = ext3_xattr_check_names(entry, end);
+        if (error)
+                goto cleanup;
+        error = ext3_xattr_find_entry(&entry, name_index, name,
+                                      end - (void *)entry, 0);
+        if (error)
+                goto cleanup;
+        size = le32_to_cpu(entry->e_value_size);
+        if (buffer) {
+                error = -ERANGE;
+                if (size > buffer_size)
+                        goto cleanup;
+                memcpy(buffer, (void *)IFIRST(header) +
+                       le16_to_cpu(entry->e_value_offs), size);
+        }
+        error = size;
+
+cleanup:
+        brelse(iloc.bh);
+        return error;
+}
+
+/*
+ * ext3_xattr_get()
+ *
+ * Copy an extended attribute into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+int
+ext3_xattr_get(struct inode *inode, int name_index, const char *name,
+               void *buffer, size_t buffer_size)
+{
+        int error;
+
+        down_read(&EXT3_I(inode)->xattr_sem);
+        error = ext3_xattr_ibody_get(inode, name_index, name, buffer,
+                                     buffer_size);
+        if (error == -ENODATA)
+                error = ext3_xattr_block_get(inode, name_index, name, buffer,
+                                             buffer_size);
+        up_read(&EXT3_I(inode)->xattr_sem);
+        return error;
+}
+
+static int
+ext3_xattr_list_entries(struct inode *inode, struct ext3_xattr_entry *entry,
+                        char *buffer, size_t buffer_size)
+{
+        size_t rest = buffer_size;
+
+        for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
+                struct xattr_handler *handler =
+                        ext3_xattr_handler(entry->e_name_index);
+
+                if (handler) {
+                        size_t size = handler->list(inode, buffer, rest,
+                                                    entry->e_name,
+                                                    entry->e_name_len);
+                        if (buffer) {
+                                if (size > rest)
+                                        return -ERANGE;
+                                buffer += size;
+                        }
+                        rest -= size;
+                }
+        }
+        return buffer_size - rest;
+}
+
+int
+ext3_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size)
+{
+        struct buffer_head *bh = NULL;
+        int error;
+
+        ea_idebug(inode, "buffer=%p, buffer_size=%ld",
+                  buffer, (long)buffer_size);
+
+        error = 0;
+        if (!EXT3_I(inode)->i_file_acl)
+                goto cleanup;
+        ea_idebug(inode, "reading block %d", EXT3_I(inode)->i_file_acl);
+        bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
+        error = -EIO;
+        if (!bh)
+                goto cleanup;
+        ea_bdebug(bh, "b_count=%d, refcount=%d",
+                atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
+        if (ext3_xattr_check_block(bh)) {
+                ext3_error(inode->i_sb, __FUNCTION__,
+                           "inode %ld: bad block %d", inode->i_ino,
+                           EXT3_I(inode)->i_file_acl);
+                error = -EIO;
+                goto cleanup;
+        }
+        ext3_xattr_cache_insert(bh);
+        error = ext3_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size);
+
+cleanup:
+        brelse(bh);
+
+        return error;
+}
+
+static int
+ext3_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size)
+{
+        struct ext3_xattr_ibody_header *header;
+        struct ext3_inode *raw_inode;
+        struct ext3_iloc iloc;
+        void *end;
+        int error;
+
+        if (!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR))
+                return 0;
+        error = ext3_get_inode_loc(inode, &iloc);
+        if (error)
+                return error;
+        raw_inode = ext3_raw_inode(&iloc);
+        header = IHDR(inode, raw_inode);
+        end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
+        error = ext3_xattr_check_names(IFIRST(header), end);
+        if (error)
+                goto cleanup;
+        error = ext3_xattr_list_entries(inode, IFIRST(header),
+                                        buffer, buffer_size);
+
+cleanup:
+        brelse(iloc.bh);
+        return error;
+}
+
+/*
+ * ext3_xattr_list()
+ *
+ * Copy a list of attribute names into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+int
+ext3_xattr_list(struct inode *inode, char *buffer, size_t buffer_size)
+{
+        int i_error, b_error;
+
+        down_read(&EXT3_I(inode)->xattr_sem);
+        i_error = ext3_xattr_ibody_list(inode, buffer, buffer_size);
+        if (i_error < 0) {
+                b_error = 0;
+        } else {
+                if (buffer) {
+                        buffer += i_error;
+                        buffer_size -= i_error;
+                }
+                b_error = ext3_xattr_block_list(inode, buffer, buffer_size);
+                if (b_error < 0)
+                        i_error = 0;
+        }
+        up_read(&EXT3_I(inode)->xattr_sem);
+        return i_error + b_error;
+}
+
+/*
+ * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
+ * not set, set it.
+ */
+static void ext3_xattr_update_super_block(handle_t *handle,
+                                          struct super_block *sb)
+{
+        if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR))
+                return;
+
+        lock_super(sb);
+        if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) {
+                EXT3_SB(sb)->s_es->s_feature_compat |=
+                        cpu_to_le32(EXT3_FEATURE_COMPAT_EXT_ATTR);
+                sb->s_dirt = 1;
+                ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
+        }
+        unlock_super(sb);
+}
+
+/*
+ * Release the xattr block BH: If the reference count is > 1, decrement
+ * it; otherwise free the block.
+ */
+static void
+ext3_xattr_release_block(handle_t *handle, struct inode *inode,
+                         struct buffer_head *bh)
+{
+        struct mb_cache_entry *ce = NULL;
+
+        ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
+        if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
+                ea_bdebug(bh, "refcount now=0; freeing");
+                if (ce)
+                        mb_cache_entry_free(ce);
+                ext3_free_blocks(handle, inode, bh->b_blocknr, 1);
+                get_bh(bh);
+                ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
+        } else {
+                if (ext3_journal_get_write_access(handle, bh) == 0) {
+                        lock_buffer(bh);
+                        BHDR(bh)->h_refcount = cpu_to_le32(
+                                le32_to_cpu(BHDR(bh)->h_refcount) - 1);
+                        ext3_journal_dirty_metadata(handle, bh);
+                        if (IS_SYNC(inode))
+                                handle->h_sync = 1;
+                        DQUOT_FREE_BLOCK(inode, 1);
+                        unlock_buffer(bh);
+                        ea_bdebug(bh, "refcount now=%d; releasing",
+                                  le32_to_cpu(BHDR(bh)->h_refcount));
+                }
+                if (ce)
+                        mb_cache_entry_release(ce);
+        }
+}
+
+struct ext3_xattr_info {
+        int name_index;
+        const char *name;
+        const void *value;
+        size_t value_len;
+};
+
+struct ext3_xattr_search {
+        struct ext3_xattr_entry *first;
+        void *base;
+        void *end;
+        struct ext3_xattr_entry *here;
+        int not_found;
+};
+
+static int
+ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s)
+{
+        struct ext3_xattr_entry *last;
+        size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
+
+        /* Compute min_offs and last. */
+        last = s->first;
+        for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) {
+                if (!last->e_value_block && last->e_value_size) {
+                        size_t offs = le16_to_cpu(last->e_value_offs);
+                        if (offs < min_offs)
+                                min_offs = offs;
+                }
+        }
+        free = min_offs - ((void *)last - s->base) - sizeof(__u32);
+        if (!s->not_found) {
+                if (!s->here->e_value_block && s->here->e_value_size) {
+                        size_t size = le32_to_cpu(s->here->e_value_size);
+                        free += EXT3_XATTR_SIZE(size);
+                }
+                free += EXT3_XATTR_LEN(name_len);
+        }
+        if (i->value) {
+                if (free < EXT3_XATTR_SIZE(i->value_len) ||
+                    free < EXT3_XATTR_LEN(name_len) +
+                           EXT3_XATTR_SIZE(i->value_len))
+                        return -ENOSPC;
+        }
+
+        if (i->value && s->not_found) {
+                /* Insert the new name. */
+                size_t size = EXT3_XATTR_LEN(name_len);
+                size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
+                memmove((void *)s->here + size, s->here, rest);
+                memset(s->here, 0, size);
+                s->here->e_name_index = i->name_index;
+                s->here->e_name_len = name_len;
+                memcpy(s->here->e_name, i->name, name_len);
+        } else {
+                if (!s->here->e_value_block && s->here->e_value_size) {
+                        void *first_val = s->base + min_offs;
+                        size_t offs = le16_to_cpu(s->here->e_value_offs);
+                        void *val = s->base + offs;
+                        size_t size = EXT3_XATTR_SIZE(
+                                le32_to_cpu(s->here->e_value_size));
+
+                        if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) {
+                                /* The old and the new value have the same
+                                   size. Just replace. */
+                                s->here->e_value_size =
+                                        cpu_to_le32(i->value_len);
+                                memset(val + size - EXT3_XATTR_PAD, 0,
+                                       EXT3_XATTR_PAD); /* Clear pad bytes. */
+                                memcpy(val, i->value, i->value_len);
+                                return 0;
+                        }
+
+                        /* Remove the old value. */
+                        memmove(first_val + size, first_val, val - first_val);
+                        memset(first_val, 0, size);
+                        s->here->e_value_size = 0;
+                        s->here->e_value_offs = 0;
+                        min_offs += size;
+
+                        /* Adjust all value offsets. */
+                        last = s->first;
+                        while (!IS_LAST_ENTRY(last)) {
+                                size_t o = le16_to_cpu(last->e_value_offs);
+                                if (!last->e_value_block &&
+                                    last->e_value_size && o < offs)
+                                        last->e_value_offs =
+                                                cpu_to_le16(o + size);
+                                last = EXT3_XATTR_NEXT(last);
+                        }
+                }
+                if (!i->value) {
+                        /* Remove the old name. */
+                        size_t size = EXT3_XATTR_LEN(name_len);
+                        last = ENTRY((void *)last - size);
+                        memmove(s->here, (void *)s->here + size,
+                                (void *)last - (void *)s->here + sizeof(__u32));
+                        memset(last, 0, size);
+                }
+        }
+
+        if (i->value) {
+                /* Insert the new value. */
+                s->here->e_value_size = cpu_to_le32(i->value_len);
+                if (i->value_len) {
+                        size_t size = EXT3_XATTR_SIZE(i->value_len);
+                        void *val = s->base + min_offs - size;
+                        s->here->e_value_offs = cpu_to_le16(min_offs - size);
+                        memset(val + size - EXT3_XATTR_PAD, 0,
+                               EXT3_XATTR_PAD); /* Clear the pad bytes. */
+                        memcpy(val, i->value, i->value_len);
+                }
+        }
+        return 0;
+}
+
+struct ext3_xattr_block_find {
+        struct ext3_xattr_search s;
+        struct buffer_head *bh;
+};
+
+int
+ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i,
+                      struct ext3_xattr_block_find *bs)
+{
+        struct super_block *sb = inode->i_sb;
+        int error;
+
+        ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
+                  i->name_index, i->name, i->value, (long)i->value_len);
+
+        if (EXT3_I(inode)->i_file_acl) {
+                /* The inode already has an extended attribute block. */
+                bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl);
+                error = -EIO;
+                if (!bs->bh)
+                        goto cleanup;
+                ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
+                        atomic_read(&(bs->bh->b_count)),
+                        le32_to_cpu(BHDR(bs->bh)->h_refcount));
+                if (ext3_xattr_check_block(bs->bh)) {
+                        ext3_error(sb, __FUNCTION__,
+                                "inode %ld: bad block %d", inode->i_ino,
+                                EXT3_I(inode)->i_file_acl);
+                        error = -EIO;
+                        goto cleanup;
+                }
+                /* Find the named attribute. */
+                bs->s.base = BHDR(bs->bh);
+                bs->s.first = BFIRST(bs->bh);
+                bs->s.end = bs->bh->b_data + bs->bh->b_size;
+                bs->s.here = bs->s.first;
+                error = ext3_xattr_find_entry(&bs->s.here, i->name_index,
+                                              i->name, bs->bh->b_size, 1);
+                if (error && error != -ENODATA)
+                        goto cleanup;
+                bs->s.not_found = error;
+        }
+        error = 0;
+
+cleanup:
+        return error;
+}
+
+static int
+ext3_xattr_block_set(handle_t *handle, struct inode *inode,
+                     struct ext3_xattr_info *i,
+                     struct ext3_xattr_block_find *bs)
+{
+        struct super_block *sb = inode->i_sb;
+        struct buffer_head *new_bh = NULL;
+        struct ext3_xattr_search *s = &bs->s;
+        struct mb_cache_entry *ce = NULL;
+        int error;
+
+#define header(x) ((struct ext3_xattr_header *)(x))
+
+        if (i->value && i->value_len > sb->s_blocksize)
+                return -ENOSPC;
+        if (s->base) {
+                ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
+                                        bs->bh->b_blocknr);
+                if (header(s->base)->h_refcount == cpu_to_le32(1)) {
+                        if (ce) {
+                                mb_cache_entry_free(ce);
+                                ce = NULL;
+                        }
+                        ea_bdebug(bs->bh, "modifying in-place");
+                        error = ext3_journal_get_write_access(handle, bs->bh);
+                        if (error)
+                                goto cleanup;
+                        lock_buffer(bs->bh);
+                        error = ext3_xattr_set_entry(i, s);
+                        if (!error) {
+                                if (!IS_LAST_ENTRY(s->first))
+                                        ext3_xattr_rehash(header(s->base),
+                                                          s->here);
+                                ext3_xattr_cache_insert(bs->bh);
+                        }
+                        unlock_buffer(bs->bh);
+                        if (error == -EIO)
+                                goto bad_block;
+                        if (!error)
+                                error = ext3_journal_dirty_metadata(handle,
+                                                                    bs->bh);
+                        if (error)
+                                goto cleanup;
+                        goto inserted;
+                } else {
+                        int offset = (char *)s->here - bs->bh->b_data;
+
+                        if (ce) {
+                                mb_cache_entry_release(ce);
+                                ce = NULL;
+                        }
+                        ea_bdebug(bs->bh, "cloning");
+                        s->base = kmalloc(bs->bh->b_size, GFP_KERNEL);
+                        error = -ENOMEM;
+                        if (s->base == NULL)
+                                goto cleanup;
+                        memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
+                        s->first = ENTRY(header(s->base)+1);
+                        header(s->base)->h_refcount = cpu_to_le32(1);
+                        s->here = ENTRY(s->base + offset);
+                        s->end = s->base + bs->bh->b_size;
+                }
+        } else {
+                /* Allocate a buffer where we construct the new block. */
+                s->base = kmalloc(sb->s_blocksize, GFP_KERNEL);
+                /* assert(header == s->base) */
+                error = -ENOMEM;
+                if (s->base == NULL)
+                        goto cleanup;
+                memset(s->base, 0, sb->s_blocksize);
+                header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
+                header(s->base)->h_blocks = cpu_to_le32(1);
+                header(s->base)->h_refcount = cpu_to_le32(1);
+                s->first = ENTRY(header(s->base)+1);
+                s->here = ENTRY(header(s->base)+1);
+                s->end = s->base + sb->s_blocksize;
+        }
+
+        error = ext3_xattr_set_entry(i, s);
+        if (error == -EIO)
+                goto bad_block;
+        if (error)
+                goto cleanup;
+        if (!IS_LAST_ENTRY(s->first))
+                ext3_xattr_rehash(header(s->base), s->here);
+
+inserted:
+        if (!IS_LAST_ENTRY(s->first)) {
+                new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce);
+                if (new_bh) {
+                        /* We found an identical block in the cache. */
+                        if (new_bh == bs->bh)
+                                ea_bdebug(new_bh, "keeping");
+                        else {
+                                /* The old block is released after updating
+                                   the inode. */
+                                error = -EDQUOT;
+                                if (DQUOT_ALLOC_BLOCK(inode, 1))
+                                        goto cleanup;
+                                error = ext3_journal_get_write_access(handle,
+                                                                      new_bh);
+                                if (error)
+                                        goto cleanup_dquot;
+                                lock_buffer(new_bh);
+                                BHDR(new_bh)->h_refcount = cpu_to_le32(1 +
+                                        le32_to_cpu(BHDR(new_bh)->h_refcount));
+                                ea_bdebug(new_bh, "reusing; refcount now=%d",
+                                        le32_to_cpu(BHDR(new_bh)->h_refcount));
+                                unlock_buffer(new_bh);
+                                error = ext3_journal_dirty_metadata(handle,
+                                                                    new_bh);
+                                if (error)
+                                        goto cleanup_dquot;
+                        }
+                        mb_cache_entry_release(ce);
+                        ce = NULL;
+                } else if (bs->bh && s->base == bs->bh->b_data) {
+                        /* We were modifying this block in-place. */
+                        ea_bdebug(bs->bh, "keeping this block");
+                        new_bh = bs->bh;
+                        get_bh(new_bh);
+                } else {
+                        /* We need to allocate a new block */
+                        int goal = le32_to_cpu(
+                                        EXT3_SB(sb)->s_es->s_first_data_block) +
+                                EXT3_I(inode)->i_block_group *
+                                EXT3_BLOCKS_PER_GROUP(sb);
+                        int block = ext3_new_block(handle, inode, goal, &error);
+                        if (error)
+                                goto cleanup;
+                        ea_idebug(inode, "creating block %d", block);
+
+                        new_bh = sb_getblk(sb, block);
+                        if (!new_bh) {
+getblk_failed:
+                                ext3_free_blocks(handle, inode, block, 1);
+                                error = -EIO;
+                                goto cleanup;
+                        }
+                        lock_buffer(new_bh);
+                        error = ext3_journal_get_create_access(handle, new_bh);
+                        if (error) {
+                                unlock_buffer(new_bh);
+                                goto getblk_failed;
+                        }
+                        memcpy(new_bh->b_data, s->base, new_bh->b_size);
+                        set_buffer_uptodate(new_bh);
+                        unlock_buffer(new_bh);
+                        ext3_xattr_cache_insert(new_bh);
+                        error = ext3_journal_dirty_metadata(handle, new_bh);
+                        if (error)
+                                goto cleanup;
+                }
+        }
+
+        /* Update the inode. */
+        EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
+
+        /* Drop the previous xattr block. */
+        if (bs->bh && bs->bh != new_bh)
+                ext3_xattr_release_block(handle, inode, bs->bh);
+        error = 0;
+
+cleanup:
+        if (ce)
+                mb_cache_entry_release(ce);
+        brelse(new_bh);
+        if (!(bs->bh && s->base == bs->bh->b_data))
+                kfree(s->base);
+
+        return error;
+
+cleanup_dquot:
+        DQUOT_FREE_BLOCK(inode, 1);
+        goto cleanup;
+
+bad_block:
+        ext3_error(inode->i_sb, __FUNCTION__,
+                   "inode %ld: bad block %d", inode->i_ino,
+                   EXT3_I(inode)->i_file_acl);
+        goto cleanup;
+
+#undef header
+}
+
+struct ext3_xattr_ibody_find {
+        struct ext3_xattr_search s;
+        struct ext3_iloc iloc;
+};
+
+int
+ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i,
+                      struct ext3_xattr_ibody_find *is)
+{
+        struct ext3_xattr_ibody_header *header;
+        struct ext3_inode *raw_inode;
+        int error;
+
+        if (EXT3_I(inode)->i_extra_isize == 0)
+                return 0;
+        raw_inode = ext3_raw_inode(&is->iloc);
+        header = IHDR(inode, raw_inode);
+        is->s.base = is->s.first = IFIRST(header);
+        is->s.here = is->s.first;
+        is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
+        if (EXT3_I(inode)->i_state & EXT3_STATE_XATTR) {
+                error = ext3_xattr_check_names(IFIRST(header), is->s.end);
+                if (error)
+                        return error;
+                /* Find the named attribute. */
+                error = ext3_xattr_find_entry(&is->s.here, i->name_index,
+                                              i->name, is->s.end -
+                                              (void *)is->s.base, 0);
+                if (error && error != -ENODATA)
+                        return error;
+                is->s.not_found = error;
+        }
+        return 0;
+}
+
+static int
+ext3_xattr_ibody_set(handle_t *handle, struct inode *inode,
+                     struct ext3_xattr_info *i,
+                     struct ext3_xattr_ibody_find *is)
+{
+        struct ext3_xattr_ibody_header *header;
+        struct ext3_xattr_search *s = &is->s;
+        int error;
+
+        if (EXT3_I(inode)->i_extra_isize == 0)
+                return -ENOSPC;
+        error = ext3_xattr_set_entry(i, s);
+        if (error)
+                return error;
+        header = IHDR(inode, ext3_raw_inode(&is->iloc));
+        if (!IS_LAST_ENTRY(s->first)) {
+                header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
+                EXT3_I(inode)->i_state |= EXT3_STATE_XATTR;
+        } else {
+                header->h_magic = cpu_to_le32(0);
+                EXT3_I(inode)->i_state &= ~EXT3_STATE_XATTR;
+        }
+        return 0;
+}
+
+/*
+ * ext3_xattr_set_handle()
+ *
+ * Create, replace or remove an extended attribute for this inode. Buffer
+ * is NULL to remove an existing extended attribute, and non-NULL to
+ * either replace an existing extended attribute, or create a new extended
+ * attribute. The flags XATTR_REPLACE and XATTR_CREATE
+ * specify that an extended attribute must exist and must not exist
+ * previous to the call, respectively.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
+                      const char *name, const void *value, size_t value_len,
+                      int flags)
+{
+        struct ext3_xattr_info i = {
+                .name_index = name_index,
+                .name = name,
+                .value = value,
+                .value_len = value_len,
+
+        };
+        struct ext3_xattr_ibody_find is = {
+                .s = { .not_found = -ENODATA, },
+        };
+        struct ext3_xattr_block_find bs = {
+                .s = { .not_found = -ENODATA, },
+        };
+        int error;
+
+        if (IS_RDONLY(inode))
+                return -EROFS;
+        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+                return -EPERM;
+        if (!name)
+                return -EINVAL;
+        if (strlen(name) > 255)
+                return -ERANGE;
+        down_write(&EXT3_I(inode)->xattr_sem);
+        error = ext3_get_inode_loc(inode, &is.iloc);
+        if (error)
+                goto cleanup;
+
+        if (EXT3_I(inode)->i_state & EXT3_STATE_NEW) {
+                struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc);
+                memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
+                EXT3_I(inode)->i_state &= ~EXT3_STATE_NEW;
+        }
+
+        error = ext3_xattr_ibody_find(inode, &i, &is);
+        if (error)
+                goto cleanup;
+        if (is.s.not_found)
+                error = ext3_xattr_block_find(inode, &i, &bs);
+        if (error)
+                goto cleanup;
+        if (is.s.not_found && bs.s.not_found) {
+                error = -ENODATA;
+                if (flags & XATTR_REPLACE)
+                        goto cleanup;
+                error = 0;
+                if (!value)
+                        goto cleanup;
+        } else {
+                error = -EEXIST;
+                if (flags & XATTR_CREATE)
+                        goto cleanup;
+        }
+        error = ext3_journal_get_write_access(handle, is.iloc.bh);
+        if (error)
+                goto cleanup;
+        if (!value) {
+                if (!is.s.not_found)
+                        error = ext3_xattr_ibody_set(handle, inode, &i, &is);
+                else if (!bs.s.not_found)
+                        error = ext3_xattr_block_set(handle, inode, &i, &bs);
+        } else {
+                error = ext3_xattr_ibody_set(handle, inode, &i, &is);
+                if (!error && !bs.s.not_found) {
+                        i.value = NULL;
+                        error = ext3_xattr_block_set(handle, inode, &i, &bs);
+                } else if (error == -ENOSPC) {
+                        error = ext3_xattr_block_set(handle, inode, &i, &bs);
+                        if (error)
+                                goto cleanup;
+                        if (!is.s.not_found) {
+                                i.value = NULL;
+                                error = ext3_xattr_ibody_set(handle, inode, &i,
+                                                             &is);
+                        }
+                }
+        }
+        if (!error) {
+                ext3_xattr_update_super_block(handle, inode->i_sb);
+                inode->i_ctime = CURRENT_TIME_SEC;
+                error = ext3_mark_iloc_dirty(handle, inode, &is.iloc);
+                /*
+                 * The bh is consumed by ext3_mark_iloc_dirty, even with
+                 * error != 0.
+                 */
+                is.iloc.bh = NULL;
+                if (IS_SYNC(inode))
+                        handle->h_sync = 1;
+        }
+
+cleanup:
+        brelse(is.iloc.bh);
+        brelse(bs.bh);
+        up_write(&EXT3_I(inode)->xattr_sem);
+        return error;
+}
+
+/*
+ * ext3_xattr_set()
+ *
+ * Like ext3_xattr_set_handle, but start from an inode. This extended
+ * attribute modification is a filesystem transaction by itself.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext3_xattr_set(struct inode *inode, int name_index, const char *name,
+               const void *value, size_t value_len, int flags)
+{
+        handle_t *handle;
+        int error, retries = 0;
+
+retry:
+        handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
+        if (IS_ERR(handle)) {
+                error = PTR_ERR(handle);
+        } else {
+                int error2;
+
+                error = ext3_xattr_set_handle(handle, inode, name_index, name,
+                                              value, value_len, flags);
+                error2 = ext3_journal_stop(handle);
+                if (error == -ENOSPC &&
+                    ext3_should_retry_alloc(inode->i_sb, &retries))
+                        goto retry;
+                if (error == 0)
+                        error = error2;
+        }
+
+        return error;
+}
+
+/*
+ * ext3_xattr_delete_inode()
+ *
+ * Free extended attribute resources associated with this inode. This
+ * is called immediately before an inode is freed. We have exclusive
+ * access to the inode.
+ */
+void
+ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
+{
+        struct buffer_head *bh = NULL;
+
+        if (!EXT3_I(inode)->i_file_acl)
+                goto cleanup;
+        bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
+        if (!bh) {
+                ext3_error(inode->i_sb, __FUNCTION__,
+                        "inode %ld: block %d read error", inode->i_ino,
+                        EXT3_I(inode)->i_file_acl);
+                goto cleanup;
+        }
+        if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
+            BHDR(bh)->h_blocks != cpu_to_le32(1)) {
+                ext3_error(inode->i_sb, __FUNCTION__,
+                        "inode %ld: bad block %d", inode->i_ino,
+                        EXT3_I(inode)->i_file_acl);
+                goto cleanup;
+        }
+        ext3_xattr_release_block(handle, inode, bh);
+        EXT3_I(inode)->i_file_acl = 0;
+
+cleanup:
+        brelse(bh);
+}
+
+/*
+ * ext3_xattr_put_super()
+ *
+ * This is called when a file system is unmounted.
+ */
+void
+ext3_xattr_put_super(struct super_block *sb)
+{
+        mb_cache_shrink(ext3_xattr_cache, sb->s_bdev);
+}
+
+/*
+ * ext3_xattr_cache_insert()
+ *
+ * Create a new entry in the extended attribute cache, and insert
+ * it unless such an entry is already in the cache.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+static void
+ext3_xattr_cache_insert(struct buffer_head *bh)
+{
+        __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
+        struct mb_cache_entry *ce;
+        int error;
+
+        ce = mb_cache_entry_alloc(ext3_xattr_cache);
+        if (!ce) {
+                ea_bdebug(bh, "out of memory");
+                return;
+        }
+        error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash);
+        if (error) {
+                mb_cache_entry_free(ce);
+                if (error == -EBUSY) {
+                        ea_bdebug(bh, "already in cache");
+                        error = 0;
+                }
+        } else {
+                ea_bdebug(bh, "inserting [%x]", (int)hash);
+                mb_cache_entry_release(ce);
+        }
+}
+
+/*
+ * ext3_xattr_cmp()
+ *
+ * Compare two extended attribute blocks for equality.
+ *
+ * Returns 0 if the blocks are equal, 1 if they differ, and
+ * a negative error number on errors.
+ */
+static int
+ext3_xattr_cmp(struct ext3_xattr_header *header1,
+               struct ext3_xattr_header *header2)
+{
+        struct ext3_xattr_entry *entry1, *entry2;
+
+        entry1 = ENTRY(header1+1);
+        entry2 = ENTRY(header2+1);
+        while (!IS_LAST_ENTRY(entry1)) {
+                if (IS_LAST_ENTRY(entry2))
+                        return 1;
+                if (entry1->e_hash != entry2->e_hash ||
+                    entry1->e_name_index != entry2->e_name_index ||
+                    entry1->e_name_len != entry2->e_name_len ||
+                    entry1->e_value_size != entry2->e_value_size ||
+                    memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
+                        return 1;
+                if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
+                        return -EIO;
+                if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
+                           (char *)header2 + le16_to_cpu(entry2->e_value_offs),
+                           le32_to_cpu(entry1->e_value_size)))
+                        return 1;
+
+                entry1 = EXT3_XATTR_NEXT(entry1);
+                entry2 = EXT3_XATTR_NEXT(entry2);
+        }
+        if (!IS_LAST_ENTRY(entry2))
+                return 1;
+        return 0;
+}
+
+/*
+ * ext3_xattr_cache_find()
+ *
+ * Find an identical extended attribute block.
+ *
+ * Returns a pointer to the block found, or NULL if such a block was
+ * not found or an error occurred.
+ */
+static struct buffer_head *
+ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header,
+                      struct mb_cache_entry **pce)
+{
+        __u32 hash = le32_to_cpu(header->h_hash);
+        struct mb_cache_entry *ce;
+
+        if (!header->h_hash)
+                return NULL;  /* never share */
+        ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
+again:
+        ce = mb_cache_entry_find_first(ext3_xattr_cache, 0,
+                                       inode->i_sb->s_bdev, hash);
+        while (ce) {
+                struct buffer_head *bh;
+
+                if (IS_ERR(ce)) {
+                        if (PTR_ERR(ce) == -EAGAIN)
+                                goto again;
+                        break;
+                }
+                bh = sb_bread(inode->i_sb, ce->e_block);
+                if (!bh) {
+                        ext3_error(inode->i_sb, __FUNCTION__,
+                                "inode %ld: block %ld read error",
+                                inode->i_ino, (unsigned long) ce->e_block);
+                } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
+                                EXT3_XATTR_REFCOUNT_MAX) {
+                        ea_idebug(inode, "block %ld refcount %d>=%d",
+                                  (unsigned long) ce->e_block,
+                                  le32_to_cpu(BHDR(bh)->h_refcount),
+                                          EXT3_XATTR_REFCOUNT_MAX);
+                } else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) {
+                        *pce = ce;
+                        return bh;
+                }
+                brelse(bh);
+                ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash);
+        }
+        return NULL;
+}
+
+#define NAME_HASH_SHIFT 5
+#define VALUE_HASH_SHIFT 16
+
+/*
+ * ext3_xattr_hash_entry()
+ *
+ * Compute the hash of an extended attribute.
+ */
+static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header,
+                                         struct ext3_xattr_entry *entry)
+{
+        __u32 hash = 0;
+        char *name = entry->e_name;
+        int n;
+
+        for (n=0; n < entry->e_name_len; n++) {
+                hash = (hash << NAME_HASH_SHIFT) ^
+                       (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
+                       *name++;
+        }
+
+        if (entry->e_value_block == 0 && entry->e_value_size != 0) {
+                __le32 *value = (__le32 *)((char *)header +
+                        le16_to_cpu(entry->e_value_offs));
+                for (n = (le32_to_cpu(entry->e_value_size) +
+                     EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) {
+                        hash = (hash << VALUE_HASH_SHIFT) ^
+                               (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
+                               le32_to_cpu(*value++);
+                }
+        }
+        entry->e_hash = cpu_to_le32(hash);
+}
+
+#undef NAME_HASH_SHIFT
+#undef VALUE_HASH_SHIFT
+
+#define BLOCK_HASH_SHIFT 16
+
+/*
+ * ext3_xattr_rehash()
+ *
+ * Re-compute the extended attribute hash value after an entry has changed.
+ */
+static void ext3_xattr_rehash(struct ext3_xattr_header *header,
+                              struct ext3_xattr_entry *entry)
+{
+        struct ext3_xattr_entry *here;
+        __u32 hash = 0;
+
+        ext3_xattr_hash_entry(header, entry);
+        here = ENTRY(header+1);
+        while (!IS_LAST_ENTRY(here)) {
+                if (!here->e_hash) {
+                        /* Block is not shared if an entry's hash value == 0 */
+                        hash = 0;
+                        break;
+                }
+                hash = (hash << BLOCK_HASH_SHIFT) ^
+                       (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
+                       le32_to_cpu(here->e_hash);
+                here = EXT3_XATTR_NEXT(here);
+        }
+        header->h_hash = cpu_to_le32(hash);
+}
+
+#undef BLOCK_HASH_SHIFT
+
+int __init
+init_ext3_xattr(void)
+{
+        ext3_xattr_cache = mb_cache_create("ext3_xattr", NULL,
+                sizeof(struct mb_cache_entry) +
+                sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6);
+        if (!ext3_xattr_cache)
+                return -ENOMEM;
+        return 0;
+}
+
+void
+exit_ext3_xattr(void)
+{
+        if (ext3_xattr_cache)
+                mb_cache_destroy(ext3_xattr_cache);
+        ext3_xattr_cache = NULL;
+}
diff --git a/fs/ext3/xattr.h b/fs/ext3/xattr.h
new file mode 100644
index 000000000000..eb31a69e82dc
--- /dev/null
+++ b/fs/ext3/xattr.h
@@ -0,0 +1,135 @@
+/*
+  File: fs/ext3/xattr.h
+
+  On-disk format of extended attributes for the ext3 filesystem.
+
+  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/config.h>
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define EXT3_XATTR_MAGIC                0xEA020000
+
+/* Maximum number of references to one attribute block */
+#define EXT3_XATTR_REFCOUNT_MAX         1024
+
+/* Name indexes */
+#define EXT3_XATTR_INDEX_USER                   1
+#define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS       2
+#define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT      3
+#define EXT3_XATTR_INDEX_TRUSTED                4
+#define EXT3_XATTR_INDEX_LUSTRE                 5
+#define EXT3_XATTR_INDEX_SECURITY               6
+
+struct ext3_xattr_header {
+        __le32  h_magic;        /* magic number for identification */
+        __le32  h_refcount;     /* reference count */
+        __le32  h_blocks;       /* number of disk blocks used */
+        __le32  h_hash;         /* hash value of all attributes */
+        __u32   h_reserved[4];  /* zero right now */
+};
+
+struct ext3_xattr_ibody_header {
+        __le32  h_magic;        /* magic number for identification */
+};
+
+struct ext3_xattr_entry {
+        __u8    e_name_len;     /* length of name */
+        __u8    e_name_index;   /* attribute name index */
+        __le16  e_value_offs;   /* offset in disk block of value */
+        __le32  e_value_block;  /* disk block attribute is stored on (n/i) */
+        __le32  e_value_size;   /* size of attribute value */
+        __le32  e_hash;         /* hash value of name and value */
+        char    e_name[0];      /* attribute name */
+};
+
+#define EXT3_XATTR_PAD_BITS             2
+#define EXT3_XATTR_PAD          (1<<EXT3_XATTR_PAD_BITS)
+#define EXT3_XATTR_ROUND                (EXT3_XATTR_PAD-1)
+#define EXT3_XATTR_LEN(name_len) \
+        (((name_len) + EXT3_XATTR_ROUND + \
+        sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
+#define EXT3_XATTR_NEXT(entry) \
+        ( (struct ext3_xattr_entry *)( \
+          (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
+#define EXT3_XATTR_SIZE(size) \
+        (((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
+
+# ifdef CONFIG_EXT3_FS_XATTR
+
+extern struct xattr_handler ext3_xattr_user_handler;
+extern struct xattr_handler ext3_xattr_trusted_handler;
+extern struct xattr_handler ext3_xattr_acl_access_handler;
+extern struct xattr_handler ext3_xattr_acl_default_handler;
+extern struct xattr_handler ext3_xattr_security_handler;
+
+extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
+
+extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
+extern int ext3_xattr_list(struct inode *, char *, size_t);
+extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
+extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
+
+extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
+extern void ext3_xattr_put_super(struct super_block *);
+
+extern int init_ext3_xattr(void);
+extern void exit_ext3_xattr(void);
+
+extern struct xattr_handler *ext3_xattr_handlers[];
+
+# else  /* CONFIG_EXT3_FS_XATTR */
+
+static inline int
+ext3_xattr_get(struct inode *inode, int name_index, const char *name,
+               void *buffer, size_t size, int flags)
+{
+        return -EOPNOTSUPP;
+}
+
+static inline int
+ext3_xattr_list(struct inode *inode, void *buffer, size_t size)
+{
+        return -EOPNOTSUPP;
+}
+
+static inline int
+ext3_xattr_set(struct inode *inode, int name_index, const char *name,
+               const void *value, size_t size, int flags)
+{
+        return -EOPNOTSUPP;
+}
+
+static inline int
+ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
+               const char *name, const void *value, size_t size, int flags)
+{
+        return -EOPNOTSUPP;
+}
+
+static inline void
+ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
+{
+}
+
+static inline void
+ext3_xattr_put_super(struct super_block *sb)
+{
+}
+
+static inline int
+init_ext3_xattr(void)
+{
+        return 0;
+}
+
+static inline void
+exit_ext3_xattr(void)
+{
+}
+
+#define ext3_xattr_handlers     NULL
+
+# endif  /* CONFIG_EXT3_FS_XATTR */
diff --git a/fs/ext3/xattr_security.c b/fs/ext3/xattr_security.c
new file mode 100644
index 000000000000..ddc1c41750e1
--- /dev/null
+++ b/fs/ext3/xattr_security.c
@@ -0,0 +1,55 @@
+/*
+ * linux/fs/ext3/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+
+static size_t
+ext3_xattr_security_list(struct inode *inode, char *list, size_t list_size,
+                         const char *name, size_t name_len)
+{
+        const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
+        const size_t total_len = prefix_len + name_len + 1;
+
+
+        if (list && total_len <= list_size) {
+                memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
+                memcpy(list+prefix_len, name, name_len);
+                list[prefix_len + name_len] = '\0';
+        }
+        return total_len;
+}
+
+static int
+ext3_xattr_security_get(struct inode *inode, const char *name,
+                       void *buffer, size_t size)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return ext3_xattr_get(inode, EXT3_XATTR_INDEX_SECURITY, name,
+                              buffer, size);
+}
+
+static int
+ext3_xattr_security_set(struct inode *inode, const char *name,
+                       const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return ext3_xattr_set(inode, EXT3_XATTR_INDEX_SECURITY, name,
+                              value, size, flags);
+}
+
+struct xattr_handler ext3_xattr_security_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .list   = ext3_xattr_security_list,
+        .get    = ext3_xattr_security_get,
+        .set    = ext3_xattr_security_set,
+};
diff --git a/fs/ext3/xattr_trusted.c b/fs/ext3/xattr_trusted.c
new file mode 100644
index 000000000000..f68bfd1cf519
--- /dev/null
+++ b/fs/ext3/xattr_trusted.c
@@ -0,0 +1,65 @@
+/*
+ * linux/fs/ext3/xattr_trusted.c
+ * Handler for trusted extended attributes.
+ *
+ * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+
+#define XATTR_TRUSTED_PREFIX "trusted."
+
+static size_t
+ext3_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
+                        const char *name, size_t name_len)
+{
+        const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
+        const size_t total_len = prefix_len + name_len + 1;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return 0;
+
+        if (list && total_len <= list_size) {
+                memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
+                memcpy(list+prefix_len, name, name_len);
+                list[prefix_len + name_len] = '\0';
+        }
+        return total_len;
+}
+
+static int
+ext3_xattr_trusted_get(struct inode *inode, const char *name,
+                       void *buffer, size_t size)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        return ext3_xattr_get(inode, EXT3_XATTR_INDEX_TRUSTED, name,
+                              buffer, size);
+}
+
+static int
+ext3_xattr_trusted_set(struct inode *inode, const char *name,
+                       const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        return ext3_xattr_set(inode, EXT3_XATTR_INDEX_TRUSTED, name,
+                              value, size, flags);
+}
+
+struct xattr_handler ext3_xattr_trusted_handler = {
+        .prefix = XATTR_TRUSTED_PREFIX,
+        .list   = ext3_xattr_trusted_list,
+        .get    = ext3_xattr_trusted_get,
+        .set    = ext3_xattr_trusted_set,
+};
diff --git a/fs/ext3/xattr_user.c b/fs/ext3/xattr_user.c
new file mode 100644
index 000000000000..e907cae7a07c
--- /dev/null
+++ b/fs/ext3/xattr_user.c
@@ -0,0 +1,79 @@
+/*
+ * linux/fs/ext3/xattr_user.c
+ * Handler for extended user attributes.
+ *
+ * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+
+#define XATTR_USER_PREFIX "user."
+
+static size_t
+ext3_xattr_user_list(struct inode *inode, char *list, size_t list_size,
+                     const char *name, size_t name_len)
+{
+        const size_t prefix_len = sizeof(XATTR_USER_PREFIX)-1;
+        const size_t total_len = prefix_len + name_len + 1;
+
+        if (!test_opt(inode->i_sb, XATTR_USER))
+                return 0;
+
+        if (list && total_len <= list_size) {
+                memcpy(list, XATTR_USER_PREFIX, prefix_len);
+                memcpy(list+prefix_len, name, name_len);
+                list[prefix_len + name_len] = '\0';
+        }
+        return total_len;
+}
+
+static int
+ext3_xattr_user_get(struct inode *inode, const char *name,
+                    void *buffer, size_t size)
+{
+        int error;
+
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        if (!test_opt(inode->i_sb, XATTR_USER))
+                return -EOPNOTSUPP;
+        error = permission(inode, MAY_READ, NULL);
+        if (error)
+                return error;
+
+        return ext3_xattr_get(inode, EXT3_XATTR_INDEX_USER, name, buffer, size);
+}
+
+static int
+ext3_xattr_user_set(struct inode *inode, const char *name,
+                    const void *value, size_t size, int flags)
+{
+        int error;
+
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        if (!test_opt(inode->i_sb, XATTR_USER))
+                return -EOPNOTSUPP;
+        if ( !S_ISREG(inode->i_mode) &&
+            (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX))
+                return -EPERM;
+        error = permission(inode, MAY_WRITE, NULL);
+        if (error)
+                return error;
+
+        return ext3_xattr_set(inode, EXT3_XATTR_INDEX_USER, name,
+                              value, size, flags);
+}
+
+struct xattr_handler ext3_xattr_user_handler = {
+        .prefix = XATTR_USER_PREFIX,
+        .list   = ext3_xattr_user_list,
+        .get    = ext3_xattr_user_get,
+        .set    = ext3_xattr_user_set,
+};