1 files changed, 1450 insertions, 0 deletions

diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
new file mode 100644
index 000000000000..45582fe8b466
--- /dev/null
+++ b/fs/reiserfs/xattr.c
@@ -0,0 +1,1450 @@
+/*
+ * linux/fs/reiserfs/xattr.c
+ *
+ * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
+ *
+ */
+
+/*
+ * In order to implement EA/ACLs in a clean, backwards compatible manner,
+ * they are implemented as files in a "private" directory.
+ * Each EA is in it's own file, with the directory layout like so (/ is assumed
+ * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
+ * directories named using the capital-hex form of the objectid and
+ * generation number are used. Inside each directory are individual files
+ * named with the name of the extended attribute.
+ *
+ * So, for objectid 12648430, we could have:
+ * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
+ * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
+ * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
+ * .. or similar.
+ *
+ * The file contents are the text of the EA. The size is known based on the
+ * stat data describing the file.
+ *
+ * In the case of system.posix_acl_access and system.posix_acl_default, since
+ * these are special cases for filesystem ACLs, they are interpreted by the
+ * kernel, in addition, they are negatively and positively cached and attached
+ * to the inode so that unnecessary lookups are avoided.
+ */
+
+#include <linux/reiserfs_fs.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/xattr.h>
+#include <linux/reiserfs_xattr.h>
+#include <linux/reiserfs_acl.h>
+#include <linux/mbcache.h>
+#include <asm/uaccess.h>
+#include <asm/checksum.h>
+#include <linux/smp_lock.h>
+#include <linux/stat.h>
+#include <asm/semaphore.h>
+
+#define FL_READONLY 128
+#define FL_DIR_SEM_HELD 256
+#define PRIVROOT_NAME ".reiserfs_priv"
+#define XAROOT_NAME   "xattrs"
+
+static struct reiserfs_xattr_handler *find_xattr_handler_prefix (const char *prefix);
+
+static struct dentry *
+create_xa_root (struct super_block *sb)
+{
+    struct dentry *privroot = dget (REISERFS_SB(sb)->priv_root);
+    struct dentry *xaroot;
+
+    /* This needs to be created at mount-time */
+    if (!privroot)
+        return ERR_PTR(-EOPNOTSUPP);
+
+    xaroot = lookup_one_len (XAROOT_NAME, privroot, strlen (XAROOT_NAME));
+    if (IS_ERR (xaroot)) {
+        goto out;
+    } else if (!xaroot->d_inode) {
+        int err;
+        down (&privroot->d_inode->i_sem);
+        err = privroot->d_inode->i_op->mkdir (privroot->d_inode, xaroot, 0700);
+        up (&privroot->d_inode->i_sem);
+
+        if (err) {
+            dput (xaroot);
+            dput (privroot);
+            return ERR_PTR (err);
+        }
+        REISERFS_SB(sb)->xattr_root = dget (xaroot);
+    }
+
+out:
+    dput (privroot);
+    return xaroot;
+}
+
+/* This will return a dentry, or error, refering to the xa root directory.
+ * If the xa root doesn't exist yet, the dentry will be returned without
+ * an associated inode. This dentry can be used with ->mkdir to create
+ * the xa directory. */
+static struct dentry *
+__get_xa_root (struct super_block *s)
+{
+    struct dentry *privroot = dget (REISERFS_SB(s)->priv_root);
+    struct dentry *xaroot = NULL;
+
+    if (IS_ERR (privroot) || !privroot)
+        return privroot;
+
+    xaroot = lookup_one_len (XAROOT_NAME, privroot, strlen (XAROOT_NAME));
+    if (IS_ERR (xaroot)) {
+        goto out;
+    } else if (!xaroot->d_inode) {
+        dput (xaroot);
+        xaroot = NULL;
+        goto out;
+    }
+
+    REISERFS_SB(s)->xattr_root = dget (xaroot);
+
+out:
+    dput (privroot);
+    return xaroot;
+}
+
+/* Returns the dentry (or NULL) referring to the root of the extended
+ * attribute directory tree. If it has already been retreived, it is used.
+ * Otherwise, we attempt to retreive it from disk. It may also return
+ * a pointer-encoded error.
+ */
+static inline struct dentry *
+get_xa_root (struct super_block *s)
+{
+    struct dentry *dentry = dget (REISERFS_SB(s)->xattr_root);
+
+    if (!dentry)
+        dentry = __get_xa_root (s);
+
+    return dentry;
+}
+
+/* Opens the directory corresponding to the inode's extended attribute store.
+ * If flags allow, the tree to the directory may be created. If creation is
+ * prohibited, -ENODATA is returned. */
+static struct dentry *
+open_xa_dir (const struct inode *inode, int flags)
+{
+    struct dentry *xaroot, *xadir;
+    char namebuf[17];
+
+    xaroot = get_xa_root (inode->i_sb);
+    if (IS_ERR (xaroot)) {
+        return xaroot;
+    } else if (!xaroot) {
+        if (flags == 0 || flags & XATTR_CREATE) {
+            xaroot = create_xa_root (inode->i_sb);
+            if (IS_ERR (xaroot))
+                return xaroot;
+        }
+        if (!xaroot)
+            return ERR_PTR (-ENODATA);
+    }
+
+    /* ok, we have xaroot open */
+
+    snprintf (namebuf, sizeof (namebuf), "%X.%X",
+              le32_to_cpu (INODE_PKEY (inode)->k_objectid),
+              inode->i_generation);
+    xadir = lookup_one_len (namebuf, xaroot, strlen (namebuf));
+    if (IS_ERR (xadir)) {
+        dput (xaroot);
+        return xadir;
+    }
+
+    if (!xadir->d_inode) {
+        int err;
+        if (flags == 0 || flags & XATTR_CREATE) {
+            /* Although there is nothing else trying to create this directory,
+             * another directory with the same hash may be created, so we need
+             * to protect against that */
+            err = xaroot->d_inode->i_op->mkdir (xaroot->d_inode, xadir, 0700);
+            if (err) {
+                dput (xaroot);
+                dput (xadir);
+                return ERR_PTR (err);
+            }
+        }
+        if (!xadir->d_inode) {
+            dput (xaroot);
+            dput (xadir);
+            return ERR_PTR (-ENODATA);
+        }
+    }
+
+    dput (xaroot);
+    return xadir;
+}
+
+/* Returns a dentry corresponding to a specific extended attribute file
+ * for the inode. If flags allow, the file is created. Otherwise, a
+ * valid or negative dentry, or an error is returned. */
+static struct dentry *
+get_xa_file_dentry (const struct inode *inode, const char *name, int flags)
+{
+    struct dentry *xadir, *xafile;
+    int err = 0;
+
+    xadir = open_xa_dir (inode, flags);
+    if (IS_ERR (xadir)) {
+        return ERR_PTR (PTR_ERR (xadir));
+    } else if (xadir && !xadir->d_inode) {
+        dput (xadir);
+        return ERR_PTR (-ENODATA);
+    }
+
+    xafile = lookup_one_len (name, xadir, strlen (name));
+    if (IS_ERR (xafile)) {
+        dput (xadir);
+        return ERR_PTR (PTR_ERR (xafile));
+    }
+
+    if (xafile->d_inode) { /* file exists */
+        if (flags & XATTR_CREATE) {
+            err = -EEXIST;
+            dput (xafile);
+            goto out;
+        }
+    } else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
+        goto out;
+    } else {
+        /* inode->i_sem is down, so nothing else can try to create
+         * the same xattr */
+        err = xadir->d_inode->i_op->create (xadir->d_inode, xafile,
+                                            0700|S_IFREG, NULL);
+
+        if (err) {
+            dput (xafile);
+            goto out;
+        }
+    }
+
+out:
+    dput (xadir);
+    if (err)
+        xafile = ERR_PTR (err);
+    return xafile;
+}
+
+
+/* Opens a file pointer to the attribute associated with inode */
+static struct file *
+open_xa_file (const struct inode *inode, const char *name, int flags)
+{
+    struct dentry *xafile;
+    struct file *fp;
+
+    xafile = get_xa_file_dentry (inode, name, flags);
+    if (IS_ERR (xafile))
+        return ERR_PTR (PTR_ERR (xafile));
+    else if (!xafile->d_inode) {
+        dput (xafile);
+        return ERR_PTR (-ENODATA);
+    }
+
+    fp = dentry_open (xafile, NULL, O_RDWR);
+    /* dentry_open dputs the dentry if it fails */
+
+    return fp;
+}
+
+
+/*
+ * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
+ * we need to drop the path before calling the filldir struct.  That
+ * would be a big performance hit to the non-xattr case, so I've copied
+ * the whole thing for now. --clm
+ *
+ * the big difference is that I go backwards through the directory,
+ * and don't mess with f->f_pos, but the idea is the same.  Do some
+ * action on each and every entry in the directory.
+ *
+ * we're called with i_sem held, so there are no worries about the directory
+ * changing underneath us.
+ */
+static int __xattr_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+    struct inode *inode = filp->f_dentry->d_inode;
+    struct cpu_key pos_key;     /* key of current position in the directory (key of directory entry) */
+    INITIALIZE_PATH (path_to_entry);
+    struct buffer_head * bh;
+    int entry_num;
+    struct item_head * ih, tmp_ih;
+    int search_res;
+    char * local_buf;
+    loff_t next_pos;
+    char small_buf[32] ; /* avoid kmalloc if we can */
+    struct reiserfs_de_head *deh;
+    int d_reclen;
+    char * d_name;
+    off_t d_off;
+    ino_t d_ino;
+    struct reiserfs_dir_entry de;
+
+
+    /* form key for search the next directory entry using f_pos field of
+       file structure */
+    next_pos = max_reiserfs_offset(inode);
+
+    while (1) {
+research:
+        if (next_pos <= DOT_DOT_OFFSET)
+            break;
+        make_cpu_key (&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
+
+        search_res = search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, &de);
+        if (search_res == IO_ERROR) {
+            // FIXME: we could just skip part of directory which could
+            // not be read
+            pathrelse(&path_to_entry);
+            return -EIO;
+        }
+
+        if (search_res == NAME_NOT_FOUND)
+            de.de_entry_num--;
+
+        set_de_name_and_namelen(&de);
+        entry_num = de.de_entry_num;
+        deh = &(de.de_deh[entry_num]);
+
+        bh = de.de_bh;
+        ih = de.de_ih;
+
+        if (!is_direntry_le_ih(ih)) {
+            reiserfs_warning(inode->i_sb, "not direntry %h", ih);
+            break;
+        }
+        copy_item_head(&tmp_ih, ih);
+
+        /* we must have found item, that is item of this directory, */
+        RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key),
+                "vs-9000: found item %h does not match to dir we readdir %K",
+                ih, &pos_key);
+
+        if (deh_offset(deh) <= DOT_DOT_OFFSET) {
+            break;
+        }
+
+        /* look for the previous entry in the directory */
+        next_pos = deh_offset (deh) - 1;
+
+        if (!de_visible (deh))
+            /* it is hidden entry */
+            continue;
+
+        d_reclen = entry_length(bh, ih, entry_num);
+        d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
+        d_off = deh_offset (deh);
+        d_ino = deh_objectid (deh);
+
+        if (!d_name[d_reclen - 1])
+            d_reclen = strlen (d_name);
+
+        if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)){
+            /* too big to send back to VFS */
+            continue ;
+        }
+
+        /* Ignore the .reiserfs_priv entry */
+        if (reiserfs_xattrs (inode->i_sb) &&
+            !old_format_only(inode->i_sb) &&
+            deh_objectid (deh) == le32_to_cpu (INODE_PKEY(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->k_objectid))
+          continue;
+
+        if (d_reclen <= 32) {
+          local_buf = small_buf ;
+        } else {
+            local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ;
+            if (!local_buf) {
+                pathrelse (&path_to_entry);
+                return -ENOMEM ;
+            }
+            if (item_moved (&tmp_ih, &path_to_entry)) {
+                reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
+
+                /* sigh, must retry.  Do this same offset again */
+                next_pos = d_off;
+                goto research;
+            }
+        }
+
+        // Note, that we copy name to user space via temporary
+        // buffer (local_buf) because filldir will block if
+        // user space buffer is swapped out. At that time
+        // entry can move to somewhere else
+        memcpy (local_buf, d_name, d_reclen);
+
+        /* the filldir function might need to start transactions,
+         * or do who knows what.  Release the path now that we've
+         * copied all the important stuff out of the deh
+         */
+        pathrelse (&path_to_entry);
+
+        if (filldir (dirent, local_buf, d_reclen, d_off, d_ino,
+                     DT_UNKNOWN) < 0) {
+            if (local_buf != small_buf) {
+                reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
+            }
+            goto end;
+        }
+        if (local_buf != small_buf) {
+            reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
+        }
+    } /* while */
+
+end:
+    pathrelse (&path_to_entry);
+    return 0;
+}
+
+/*
+ * this could be done with dedicated readdir ops for the xattr files,
+ * but I want to get something working asap
+ * this is stolen from vfs_readdir
+ *
+ */
+static
+int xattr_readdir(struct file *file, filldir_t filler, void *buf)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        int res = -ENOTDIR;
+        if (!file->f_op || !file->f_op->readdir)
+                goto out;
+        down(&inode->i_sem);
+//        down(&inode->i_zombie);
+        res = -ENOENT;
+        if (!IS_DEADDIR(inode)) {
+                lock_kernel();
+                res = __xattr_readdir(file, buf, filler);
+                unlock_kernel();
+        }
+//        up(&inode->i_zombie);
+        up(&inode->i_sem);
+out:
+        return res;
+}
+
+
+/* Internal operations on file data */
+static inline void
+reiserfs_put_page(struct page *page)
+{
+        kunmap(page);
+        page_cache_release(page);
+}
+
+static struct page *
+reiserfs_get_page(struct inode *dir, unsigned long n)
+{
+        struct address_space *mapping = dir->i_mapping;
+        struct page *page;
+        /* We can deadlock if we try to free dentries,
+           and an unlink/rmdir has just occured - GFP_NOFS avoids this */
+        mapping->flags = (mapping->flags & ~__GFP_BITS_MASK) | GFP_NOFS;
+        page = read_cache_page (mapping, n,
+                                (filler_t*)mapping->a_ops->readpage, NULL);
+        if (!IS_ERR(page)) {
+                wait_on_page_locked(page);
+                kmap(page);
+                if (!PageUptodate(page))
+                        goto fail;
+
+                if (PageError(page))
+                        goto fail;
+        }
+        return page;
+
+fail:
+        reiserfs_put_page(page);
+        return ERR_PTR(-EIO);
+}
+
+static inline __u32
+xattr_hash (const char *msg, int len)
+{
+    return csum_partial (msg, len, 0);
+}
+
+/* Generic extended attribute operations that can be used by xa plugins */
+
+/*
+ * inode->i_sem: down
+ */
+int
+reiserfs_xattr_set (struct inode *inode, const char *name, const void *buffer,
+                    size_t buffer_size, int flags)
+{
+    int err = 0;
+    struct file *fp;
+    struct page *page;
+    char *data;
+    struct address_space *mapping;
+    size_t file_pos = 0;
+    size_t buffer_pos = 0;
+    struct inode *xinode;
+    struct iattr newattrs;
+    __u32 xahash = 0;
+
+    if (IS_RDONLY (inode))
+        return -EROFS;
+
+    if (IS_IMMUTABLE (inode) || IS_APPEND (inode))
+        return -EPERM;
+
+    if (get_inode_sd_version (inode) == STAT_DATA_V1)
+        return -EOPNOTSUPP;
+
+    /* Empty xattrs are ok, they're just empty files, no hash */
+    if (buffer && buffer_size)
+        xahash = xattr_hash (buffer, buffer_size);
+
+open_file:
+    fp = open_xa_file (inode, name, flags);
+    if (IS_ERR (fp)) {
+        err = PTR_ERR (fp);
+        goto out;
+    }
+
+    xinode = fp->f_dentry->d_inode;
+    REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+
+    /* we need to copy it off.. */
+    if (xinode->i_nlink > 1) {
+        fput(fp);
+        err = reiserfs_xattr_del (inode, name);
+        if (err < 0)
+            goto out;
+        /* We just killed the old one, we're not replacing anymore */
+        if (flags & XATTR_REPLACE)
+            flags &= ~XATTR_REPLACE;
+        goto open_file;
+    }
+
+    /* Resize it so we're ok to write there */
+    newattrs.ia_size = buffer_size;
+    newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
+    down (&xinode->i_sem);
+    err = notify_change(fp->f_dentry, &newattrs);
+    if (err)
+        goto out_filp;
+
+    mapping = xinode->i_mapping;
+    while (buffer_pos < buffer_size || buffer_pos == 0) {
+        size_t chunk;
+        size_t skip = 0;
+        size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
+        if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
+            chunk = PAGE_CACHE_SIZE;
+        else
+            chunk = buffer_size - buffer_pos;
+
+        page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT);
+        if (IS_ERR (page)) {
+            err = PTR_ERR (page);
+            goto out_filp;
+        }
+
+        lock_page (page);
+        data = page_address (page);
+
+        if (file_pos == 0) {
+            struct reiserfs_xattr_header *rxh;
+            skip = file_pos = sizeof (struct reiserfs_xattr_header);
+            if (chunk + skip > PAGE_CACHE_SIZE)
+                chunk = PAGE_CACHE_SIZE - skip;
+            rxh = (struct reiserfs_xattr_header *)data;
+            rxh->h_magic = cpu_to_le32 (REISERFS_XATTR_MAGIC);
+            rxh->h_hash = cpu_to_le32 (xahash);
+        }
+
+        err = mapping->a_ops->prepare_write (fp, page, page_offset,
+                                             page_offset + chunk + skip);
+        if (!err) {
+            if (buffer)
+                memcpy (data + skip, buffer + buffer_pos, chunk);
+            err = mapping->a_ops->commit_write (fp, page, page_offset,
+                                                page_offset + chunk + skip);
+        }
+        unlock_page (page);
+        reiserfs_put_page (page);
+        buffer_pos += chunk;
+        file_pos += chunk;
+        skip = 0;
+        if (err || buffer_size == 0 || !buffer)
+            break;
+    }
+
+    /* We can't mark the inode dirty if it's not hashed. This is the case
+     * when we're inheriting the default ACL. If we dirty it, the inode
+     * gets marked dirty, but won't (ever) make it onto the dirty list until
+     * it's synced explicitly to clear I_DIRTY. This is bad. */
+    if (!hlist_unhashed(&inode->i_hash)) {
+        inode->i_ctime = CURRENT_TIME_SEC;
+        mark_inode_dirty (inode);
+    }
+
+out_filp:
+    up (&xinode->i_sem);
+    fput(fp);
+
+out:
+    return err;
+}
+
+/*
+ * inode->i_sem: down
+ */
+int
+reiserfs_xattr_get (const struct inode *inode, const char *name, void *buffer,
+                    size_t buffer_size)
+{
+    ssize_t err = 0;
+    struct file *fp;
+    size_t isize;
+    size_t file_pos = 0;
+    size_t buffer_pos = 0;
+    struct page *page;
+    struct inode *xinode;
+    __u32 hash = 0;
+
+    if (name == NULL)
+        return -EINVAL;
+
+    /* We can't have xattrs attached to v1 items since they don't have
+     * generation numbers */
+    if (get_inode_sd_version (inode) == STAT_DATA_V1)
+        return -EOPNOTSUPP;
+
+    fp = open_xa_file (inode, name, FL_READONLY);
+    if (IS_ERR (fp)) {
+        err = PTR_ERR (fp);
+        goto out;
+    }
+
+    xinode = fp->f_dentry->d_inode;
+    isize = xinode->i_size;
+    REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+
+    /* Just return the size needed */
+    if (buffer == NULL) {
+        err = isize - sizeof (struct reiserfs_xattr_header);
+        goto out_dput;
+    }
+
+    if (buffer_size < isize - sizeof (struct reiserfs_xattr_header)) {
+        err = -ERANGE;
+        goto out_dput;
+    }
+
+    while (file_pos < isize) {
+        size_t chunk;
+        char *data;
+        size_t skip = 0;
+        if (isize - file_pos > PAGE_CACHE_SIZE)
+            chunk = PAGE_CACHE_SIZE;
+        else
+            chunk = isize - file_pos;
+
+        page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT);
+        if (IS_ERR (page)) {
+            err = PTR_ERR (page);
+            goto out_dput;
+        }
+
+        lock_page (page);
+        data = page_address (page);
+        if (file_pos == 0) {
+            struct reiserfs_xattr_header *rxh =
+                                        (struct reiserfs_xattr_header *)data;
+            skip = file_pos = sizeof (struct reiserfs_xattr_header);
+            chunk -= skip;
+            /* Magic doesn't match up.. */
+            if (rxh->h_magic != cpu_to_le32 (REISERFS_XATTR_MAGIC)) {
+                unlock_page (page);
+                reiserfs_put_page (page);
+                reiserfs_warning (inode->i_sb, "Invalid magic for xattr (%s) "
+                                  "associated with %k", name,
+                                  INODE_PKEY (inode));
+                err = -EIO;
+                goto out_dput;
+            }
+            hash = le32_to_cpu (rxh->h_hash);
+        }
+        memcpy (buffer + buffer_pos, data + skip, chunk);
+        unlock_page (page);
+        reiserfs_put_page (page);
+        file_pos += chunk;
+        buffer_pos += chunk;
+        skip = 0;
+    }
+    err = isize - sizeof (struct reiserfs_xattr_header);
+
+    if (xattr_hash (buffer, isize - sizeof (struct reiserfs_xattr_header)) != hash) {
+        reiserfs_warning (inode->i_sb, "Invalid hash for xattr (%s) associated "
+                          "with %k", name, INODE_PKEY (inode));
+        err = -EIO;
+    }
+
+out_dput:
+    fput(fp);
+
+out:
+    return err;
+}
+
+static int
+__reiserfs_xattr_del (struct dentry *xadir, const char *name, int namelen)
+{
+    struct dentry *dentry;
+    struct inode *dir = xadir->d_inode;
+    int err = 0;
+
+    dentry = lookup_one_len (name, xadir, namelen);
+    if (IS_ERR (dentry)) {
+        err = PTR_ERR (dentry);
+        goto out;
+    } else if (!dentry->d_inode) {
+        err = -ENODATA;
+        goto out_file;
+    }
+
+    /* Skip directories.. */
+    if (S_ISDIR (dentry->d_inode->i_mode))
+        goto out_file;
+
+    if (!is_reiserfs_priv_object (dentry->d_inode)) {
+        reiserfs_warning (dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
+                                     "priv flag set [parent is %sset].",
+                        le32_to_cpu (INODE_PKEY (dentry->d_inode)->k_objectid),
+                        xadir->d_name.len, xadir->d_name.name, namelen, name,
+                        is_reiserfs_priv_object (xadir->d_inode) ? "" : "not ");
+        dput (dentry);
+        return -EIO;
+    }
+
+    err = dir->i_op->unlink (dir, dentry);
+    if (!err)
+        d_delete (dentry);
+
+out_file:
+    dput (dentry);
+
+out:
+    return err;
+}
+
+
+int
+reiserfs_xattr_del (struct inode *inode, const char *name)
+{
+    struct dentry *dir;
+    int err;
+
+    if (IS_RDONLY (inode))
+        return -EROFS;
+
+    dir = open_xa_dir (inode, FL_READONLY);
+    if (IS_ERR (dir)) {
+        err = PTR_ERR (dir);
+        goto out;
+    }
+
+    err = __reiserfs_xattr_del (dir, name, strlen (name));
+    dput (dir);
+
+    if (!err) {
+        inode->i_ctime = CURRENT_TIME_SEC;
+        mark_inode_dirty (inode);
+    }
+
+out:
+    return err;
+}
+
+/* The following are side effects of other operations that aren't explicitly
+ * modifying extended attributes. This includes operations such as permissions
+ * or ownership changes, object deletions, etc. */
+
+static int
+reiserfs_delete_xattrs_filler (void *buf, const char *name, int namelen,
+                               loff_t offset, ino_t ino, unsigned int d_type)
+{
+    struct dentry *xadir = (struct dentry *)buf;
+
+    return __reiserfs_xattr_del (xadir, name, namelen);
+
+}
+
+/* This is called w/ inode->i_sem downed */
+int
+reiserfs_delete_xattrs (struct inode *inode)
+{
+    struct file *fp;
+    struct dentry *dir, *root;
+    int err = 0;
+
+    /* Skip out, an xattr has no xattrs associated with it */
+    if (is_reiserfs_priv_object (inode) ||
+        get_inode_sd_version (inode) == STAT_DATA_V1 ||
+        !reiserfs_xattrs(inode->i_sb))
+    {
+        return 0;
+    }
+    reiserfs_read_lock_xattrs (inode->i_sb);
+    dir = open_xa_dir (inode, FL_READONLY);
+    reiserfs_read_unlock_xattrs (inode->i_sb);
+    if (IS_ERR (dir)) {
+        err = PTR_ERR (dir);
+        goto out;
+    } else if (!dir->d_inode) {
+        dput (dir);
+        return 0;
+    }
+
+    fp = dentry_open (dir, NULL, O_RDWR);
+    if (IS_ERR (fp)) {
+        err = PTR_ERR (fp);
+        /* dentry_open dputs the dentry if it fails */
+        goto out;
+    }
+
+    lock_kernel ();
+    err = xattr_readdir (fp, reiserfs_delete_xattrs_filler, dir);
+    if (err) {
+        unlock_kernel ();
+        goto out_dir;
+    }
+
+    /* Leftovers besides . and .. -- that's not good. */
+    if (dir->d_inode->i_nlink <= 2) {
+        root = get_xa_root (inode->i_sb);
+        reiserfs_write_lock_xattrs (inode->i_sb);
+        err = vfs_rmdir (root->d_inode, dir);
+        reiserfs_write_unlock_xattrs (inode->i_sb);
+        dput (root);
+    } else {
+        reiserfs_warning (inode->i_sb,
+                          "Couldn't remove all entries in directory");
+    }
+    unlock_kernel ();
+
+out_dir:
+    fput(fp);
+
+out:
+    if (!err)
+        REISERFS_I(inode)->i_flags = REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
+    return err;
+}
+
+struct reiserfs_chown_buf {
+    struct inode *inode;
+    struct dentry *xadir;
+    struct iattr *attrs;
+};
+
+/* XXX: If there is a better way to do this, I'd love to hear about it */
+static int
+reiserfs_chown_xattrs_filler (void *buf, const char *name, int namelen,
+                               loff_t offset, ino_t ino, unsigned int d_type)
+{
+    struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
+    struct dentry *xafile, *xadir = chown_buf->xadir;
+    struct iattr *attrs = chown_buf->attrs;
+    int err = 0;
+
+    xafile = lookup_one_len (name, xadir, namelen);
+    if (IS_ERR (xafile))
+        return PTR_ERR (xafile);
+    else if (!xafile->d_inode) {
+        dput (xafile);
+        return -ENODATA;
+    }
+
+    if (!S_ISDIR (xafile->d_inode->i_mode))
+        err = notify_change (xafile, attrs);
+    dput (xafile);
+
+    return err;
+}
+
+int
+reiserfs_chown_xattrs (struct inode *inode, struct iattr *attrs)
+{
+    struct file *fp;
+    struct dentry *dir;
+    int err = 0;
+    struct reiserfs_chown_buf buf;
+    unsigned int ia_valid = attrs->ia_valid;
+
+    /* Skip out, an xattr has no xattrs associated with it */
+    if (is_reiserfs_priv_object (inode) ||
+        get_inode_sd_version (inode) == STAT_DATA_V1 ||
+        !reiserfs_xattrs(inode->i_sb))
+    {
+        return 0;
+    }
+    reiserfs_read_lock_xattrs (inode->i_sb);
+    dir = open_xa_dir (inode, FL_READONLY);
+    reiserfs_read_unlock_xattrs (inode->i_sb);
+    if (IS_ERR (dir)) {
+        if (PTR_ERR (dir) != -ENODATA)
+            err = PTR_ERR (dir);
+        goto out;
+    } else if (!dir->d_inode) {
+        dput (dir);
+        goto out;
+    }
+
+    fp = dentry_open (dir, NULL, O_RDWR);
+    if (IS_ERR (fp)) {
+        err = PTR_ERR (fp);
+        /* dentry_open dputs the dentry if it fails */
+        goto out;
+    }
+
+    lock_kernel ();
+
+    attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
+    buf.xadir = dir;
+    buf.attrs = attrs;
+    buf.inode = inode;
+
+    err = xattr_readdir (fp, reiserfs_chown_xattrs_filler, &buf);
+    if (err) {
+        unlock_kernel ();
+        goto out_dir;
+    }
+
+    err = notify_change (dir, attrs);
+    unlock_kernel ();
+
+out_dir:
+    fput(fp);
+
+out:
+    attrs->ia_valid = ia_valid;
+    return err;
+}
+
+
+/* Actual operations that are exported to VFS-land */
+
+/*
+ * Inode operation getxattr()
+ * Preliminary locking: we down dentry->d_inode->i_sem
+ */
+ssize_t
+reiserfs_getxattr (struct dentry *dentry, const char *name, void *buffer,
+                   size_t size)
+{
+    struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+    int err;
+
+    if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
+        get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+        return -EOPNOTSUPP;
+
+    reiserfs_read_lock_xattr_i (dentry->d_inode);
+    reiserfs_read_lock_xattrs (dentry->d_sb);
+    err = xah->get (dentry->d_inode, name, buffer, size);
+    reiserfs_read_unlock_xattrs (dentry->d_sb);
+    reiserfs_read_unlock_xattr_i (dentry->d_inode);
+    return err;
+}
+
+
+/*
+ * Inode operation setxattr()
+ *
+ * dentry->d_inode->i_sem down
+ */
+int
+reiserfs_setxattr (struct dentry *dentry, const char *name, const void *value,
+                   size_t size, int flags)
+{
+    struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+    int err;
+    int lock;
+
+    if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
+        get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+        return -EOPNOTSUPP;
+
+    if (IS_RDONLY (dentry->d_inode))
+        return -EROFS;
+
+    if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode))
+        return -EROFS;
+
+    reiserfs_write_lock_xattr_i (dentry->d_inode);
+    lock = !has_xattr_dir (dentry->d_inode);
+    if (lock)
+        reiserfs_write_lock_xattrs (dentry->d_sb);
+    else
+        reiserfs_read_lock_xattrs (dentry->d_sb);
+    err = xah->set (dentry->d_inode, name, value, size, flags);
+    if (lock)
+        reiserfs_write_unlock_xattrs (dentry->d_sb);
+    else
+        reiserfs_read_unlock_xattrs (dentry->d_sb);
+    reiserfs_write_unlock_xattr_i (dentry->d_inode);
+    return err;
+}
+
+/*
+ * Inode operation removexattr()
+ *
+ * dentry->d_inode->i_sem down
+ */
+int
+reiserfs_removexattr (struct dentry *dentry, const char *name)
+{
+    int err;
+    struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+
+    if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
+        get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+        return -EOPNOTSUPP;
+
+    if (IS_RDONLY (dentry->d_inode))
+        return -EROFS;
+
+    if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode))
+        return -EPERM;
+
+    reiserfs_write_lock_xattr_i (dentry->d_inode);
+    reiserfs_read_lock_xattrs (dentry->d_sb);
+
+    /* Deletion pre-operation */
+    if (xah->del) {
+        err = xah->del (dentry->d_inode, name);
+        if (err)
+            goto out;
+    }
+
+    err = reiserfs_xattr_del (dentry->d_inode, name);
+
+    dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
+    mark_inode_dirty (dentry->d_inode);
+
+out:
+    reiserfs_read_unlock_xattrs (dentry->d_sb);
+    reiserfs_write_unlock_xattr_i (dentry->d_inode);
+    return err;
+}
+
+
+/* This is what filldir will use:
+ * r_pos will always contain the amount of space required for the entire
+ * list. If r_pos becomes larger than r_size, we need more space and we
+ * return an error indicating this. If r_pos is less than r_size, then we've
+ * filled the buffer successfully and we return success */
+struct reiserfs_listxattr_buf {
+    int r_pos;
+    int r_size;
+    char *r_buf;
+    struct inode *r_inode;
+};
+
+static int
+reiserfs_listxattr_filler (void *buf, const char *name, int namelen,
+                           loff_t offset, ino_t ino, unsigned int d_type)
+{
+    struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
+    int len = 0;
+    if (name[0] != '.' || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
+        struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
+        if (!xah) return 0; /* Unsupported xattr name, skip it */
+
+        /* We call ->list() twice because the operation isn't required to just
+         * return the name back - we want to make sure we have enough space */
+        len += xah->list (b->r_inode, name, namelen, NULL);
+
+        if (len) {
+            if (b->r_pos + len + 1 <= b->r_size) {
+                char *p = b->r_buf + b->r_pos;
+                p += xah->list (b->r_inode, name, namelen, p);
+                *p++ = '\0';
+            }
+            b->r_pos += len + 1;
+        }
+    }
+
+    return 0;
+}
+/*
+ * Inode operation listxattr()
+ *
+ * Preliminary locking: we down dentry->d_inode->i_sem
+ */
+ssize_t
+reiserfs_listxattr (struct dentry *dentry, char *buffer, size_t size)
+{
+    struct file *fp;
+    struct dentry *dir;
+    int err = 0;
+    struct reiserfs_listxattr_buf buf;
+
+    if (!dentry->d_inode)
+        return -EINVAL;
+
+    if (!reiserfs_xattrs(dentry->d_sb) ||
+        get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
+        return -EOPNOTSUPP;
+
+    reiserfs_read_lock_xattr_i (dentry->d_inode);
+    reiserfs_read_lock_xattrs (dentry->d_sb);
+    dir = open_xa_dir (dentry->d_inode, FL_READONLY);
+    reiserfs_read_unlock_xattrs (dentry->d_sb);
+    if (IS_ERR (dir)) {
+        err = PTR_ERR (dir);
+        if (err == -ENODATA)
+            err = 0; /* Not an error if there aren't any xattrs */
+        goto out;
+    }
+
+    fp = dentry_open (dir, NULL, O_RDWR);
+    if (IS_ERR (fp)) {
+        err = PTR_ERR (fp);
+        /* dentry_open dputs the dentry if it fails */
+        goto out;
+    }
+
+    buf.r_buf = buffer;
+    buf.r_size = buffer ? size : 0;
+    buf.r_pos = 0;
+    buf.r_inode = dentry->d_inode;
+
+    REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
+
+    err = xattr_readdir (fp, reiserfs_listxattr_filler, &buf);
+    if (err)
+        goto out_dir;
+
+    if (buf.r_pos > buf.r_size && buffer != NULL)
+        err = -ERANGE;
+    else
+        err = buf.r_pos;
+
+out_dir:
+    fput(fp);
+
+out:
+    reiserfs_read_unlock_xattr_i (dentry->d_inode);
+    return err;
+}
+
+/* This is the implementation for the xattr plugin infrastructure */
+static struct list_head xattr_handlers = LIST_HEAD_INIT (xattr_handlers);
+static DEFINE_RWLOCK(handler_lock);
+
+static struct reiserfs_xattr_handler *
+find_xattr_handler_prefix (const char *prefix)
+{
+    struct reiserfs_xattr_handler *xah = NULL;
+    struct list_head *p;
+
+    read_lock (&handler_lock);
+    list_for_each (p, &xattr_handlers) {
+        xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
+        if (strncmp (xah->prefix, prefix, strlen (xah->prefix)) == 0)
+            break;
+        xah = NULL;
+    }
+
+    read_unlock (&handler_lock);
+    return xah;
+}
+
+static void
+__unregister_handlers (void)
+{
+    struct reiserfs_xattr_handler *xah;
+    struct list_head *p, *tmp;
+
+    list_for_each_safe (p, tmp, &xattr_handlers) {
+        xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
+        if (xah->exit)
+            xah->exit();
+
+        list_del_init (p);
+    }
+    INIT_LIST_HEAD (&xattr_handlers);
+}
+
+int __init
+reiserfs_xattr_register_handlers (void)
+{
+    int err = 0;
+    struct reiserfs_xattr_handler *xah;
+    struct list_head *p;
+
+    write_lock (&handler_lock);
+
+    /* If we're already initialized, nothing to do */
+    if (!list_empty (&xattr_handlers)) {
+        write_unlock (&handler_lock);
+        return 0;
+    }
+
+    /* Add the handlers */
+    list_add_tail (&user_handler.handlers, &xattr_handlers);
+    list_add_tail (&trusted_handler.handlers, &xattr_handlers);
+#ifdef CONFIG_REISERFS_FS_SECURITY
+    list_add_tail (&security_handler.handlers, &xattr_handlers);
+#endif
+#ifdef CONFIG_REISERFS_FS_POSIX_ACL
+    list_add_tail (&posix_acl_access_handler.handlers, &xattr_handlers);
+    list_add_tail (&posix_acl_default_handler.handlers, &xattr_handlers);
+#endif
+
+    /* Run initializers, if available */
+    list_for_each (p, &xattr_handlers) {
+        xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
+        if (xah->init) {
+            err = xah->init ();
+            if (err) {
+                list_del_init (p);
+                break;
+            }
+        }
+    }
+
+    /* Clean up other handlers, if any failed */
+    if (err)
+        __unregister_handlers ();
+
+    write_unlock (&handler_lock);
+    return err;
+}
+
+void
+reiserfs_xattr_unregister_handlers (void)
+{
+    write_lock (&handler_lock);
+    __unregister_handlers ();
+    write_unlock (&handler_lock);
+}
+
+/* This will catch lookups from the fs root to .reiserfs_priv */
+static int
+xattr_lookup_poison (struct dentry *dentry, struct qstr *q1, struct qstr *name)
+{
+    struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
+    if (name->len == priv_root->d_name.len &&
+        name->hash == priv_root->d_name.hash &&
+        !memcmp (name->name, priv_root->d_name.name, name->len)) {
+            return -ENOENT;
+    } else if (q1->len == name->len &&
+               !memcmp(q1->name, name->name, name->len))
+        return 0;
+    return 1;
+}
+
+static struct dentry_operations xattr_lookup_poison_ops = {
+    .d_compare = xattr_lookup_poison,
+};
+
+
+/* We need to take a copy of the mount flags since things like
+ * MS_RDONLY don't get set until *after* we're called.
+ * mount_flags != mount_options */
+int
+reiserfs_xattr_init (struct super_block *s, int mount_flags)
+{
+  int err = 0;
+
+  /* We need generation numbers to ensure that the oid mapping is correct
+   * v3.5 filesystems don't have them. */
+  if (!old_format_only (s)) {
+    set_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
+  } else if (reiserfs_xattrs_optional (s)) {
+    /* Old format filesystem, but optional xattrs have been enabled
+     * at mount time. Error out. */
+    reiserfs_warning (s, "xattrs/ACLs not supported on pre v3.6 "
+                      "format filesystem. Failing mount.");
+    err = -EOPNOTSUPP;
+    goto error;
+  } else {
+    /* Old format filesystem, but no optional xattrs have been enabled. This
+     * means we silently disable xattrs on the filesystem. */
+    clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
+  }
+
+  /* If we don't have the privroot located yet - go find it */
+  if (reiserfs_xattrs (s) && !REISERFS_SB(s)->priv_root) {
+      struct dentry *dentry;
+      dentry = lookup_one_len (PRIVROOT_NAME, s->s_root,
+                               strlen (PRIVROOT_NAME));
+      if (!IS_ERR (dentry)) {
+        if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
+            struct inode *inode = dentry->d_parent->d_inode;
+            down (&inode->i_sem);
+            err = inode->i_op->mkdir (inode, dentry, 0700);
+            up (&inode->i_sem);
+            if (err) {
+                dput (dentry);
+                dentry = NULL;
+            }
+
+            if (dentry && dentry->d_inode)
+                reiserfs_warning (s, "Created %s on %s - reserved for "
+                                  "xattr storage.", PRIVROOT_NAME,
+                                  reiserfs_bdevname (inode->i_sb));
+        } else if (!dentry->d_inode) {
+            dput (dentry);
+            dentry = NULL;
+        }
+      } else
+        err = PTR_ERR (dentry);
+
+      if (!err && dentry) {
+          s->s_root->d_op = &xattr_lookup_poison_ops;
+          reiserfs_mark_inode_private (dentry->d_inode);
+          REISERFS_SB(s)->priv_root = dentry;
+      } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
+          /* If we're read-only it just means that the dir hasn't been
+           * created. Not an error -- just no xattrs on the fs. We'll
+           * check again if we go read-write */
+          reiserfs_warning (s, "xattrs/ACLs enabled and couldn't "
+                            "find/create .reiserfs_priv. Failing mount.");
+          err = -EOPNOTSUPP;
+      }
+  }
+
+error:
+   /* This is only nonzero if there was an error initializing the xattr
+    * directory or if there is a condition where we don't support them. */
+    if (err) {
+          clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
+          clear_bit (REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
+          clear_bit (REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
+    }
+
+    /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
+    s->s_flags = s->s_flags & ~MS_POSIXACL;
+    if (reiserfs_posixacl (s))
+        s->s_flags |= MS_POSIXACL;
+
+    return err;
+}
+
+static int
+__reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd,
+                       int need_lock)
+{
+        umode_t                 mode = inode->i_mode;
+
+        if (mask & MAY_WRITE) {
+                /*
+                 * Nobody gets write access to a read-only fs.
+                 */
+                if (IS_RDONLY(inode) &&
+                    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
+                        return -EROFS;
+
+                /*
+                 * Nobody gets write access to an immutable file.
+                 */
+                if (IS_IMMUTABLE(inode))
+                        return -EACCES;
+        }
+
+        /* We don't do permission checks on the internal objects.
+        * Permissions are determined by the "owning" object. */
+        if (is_reiserfs_priv_object (inode))
+                return 0;
+
+        if (current->fsuid == inode->i_uid) {
+                mode >>= 6;
+#ifdef CONFIG_REISERFS_FS_POSIX_ACL
+        } else if (reiserfs_posixacl(inode->i_sb) &&
+                   get_inode_sd_version (inode) != STAT_DATA_V1) {
+                struct posix_acl *acl;
+
+                /* ACL can't contain additional permissions if
+                   the ACL_MASK entry is 0 */
+                if (!(mode & S_IRWXG))
+                        goto check_groups;
+
+                if (need_lock) {
+                    reiserfs_read_lock_xattr_i (inode);
+                    reiserfs_read_lock_xattrs (inode->i_sb);
+                }
+                acl = reiserfs_get_acl (inode, ACL_TYPE_ACCESS);
+                if (need_lock) {
+                    reiserfs_read_unlock_xattrs (inode->i_sb);
+                    reiserfs_read_unlock_xattr_i (inode);
+                }
+                if (IS_ERR (acl)) {
+                    if (PTR_ERR (acl) == -ENODATA)
+                        goto check_groups;
+                    return PTR_ERR (acl);
+                }
+
+                if (acl) {
+                    int err = posix_acl_permission (inode, acl, mask);
+                    posix_acl_release (acl);
+                    if (err == -EACCES) {
+                        goto check_capabilities;
+                    }
+                    return err;
+                } else {
+                        goto check_groups;
+                }
+#endif
+        } else {
+check_groups:
+                if (in_group_p(inode->i_gid))
+                        mode >>= 3;
+        }
+
+        /*
+         * If the DACs are ok we don't need any capability check.
+         */
+        if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
+                return 0;
+
+check_capabilities:
+        /*
+         * Read/write DACs are always overridable.
+         * Executable DACs are overridable if at least one exec bit is set.
+         */
+        if (!(mask & MAY_EXEC) ||
+            (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
+                if (capable(CAP_DAC_OVERRIDE))
+                        return 0;
+
+        /*
+         * Searching includes executable on directories, else just read.
+         */
+        if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
+                if (capable(CAP_DAC_READ_SEARCH))
+                        return 0;
+
+        return -EACCES;
+}
+
+int
+reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd)
+{
+    return __reiserfs_permission (inode, mask, nd, 1);
+}
+
+int
+reiserfs_permission_locked (struct inode *inode, int mask, struct nameidata *nd)
+{
+    return __reiserfs_permission (inode, mask, nd, 0);
+}