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!

1 files changed, 1161 insertions, 0 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
new file mode 100644
index 000000000000..37ca77a157ba
--- /dev/null
+++ b/fs/ext2/super.c
@@ -0,0 +1,1161 @@
+/*
+ *  linux/fs/ext2/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/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/parser.h>
+#include <linux/random.h>
+#include <linux/buffer_head.h>
+#include <linux/smp_lock.h>
+#include <linux/vfs.h>
+#include <asm/uaccess.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+static void ext2_sync_super(struct super_block *sb,
+                            struct ext2_super_block *es);
+static int ext2_remount (struct super_block * sb, int * flags, char * data);
+static int ext2_statfs (struct super_block * sb, struct kstatfs * buf);
+
+void ext2_error (struct super_block * sb, const char * function,
+                 const char * fmt, ...)
+{
+        va_list args;
+        struct ext2_sb_info *sbi = EXT2_SB(sb);
+        struct ext2_super_block *es = sbi->s_es;
+
+        if (!(sb->s_flags & MS_RDONLY)) {
+                sbi->s_mount_state |= EXT2_ERROR_FS;
+                es->s_state =
+                        cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
+                ext2_sync_super(sb, es);
+        }
+
+        va_start(args, fmt);
+        printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
+        vprintk(fmt, args);
+        printk("\n");
+        va_end(args);
+
+        if (test_opt(sb, ERRORS_PANIC))
+                panic("EXT2-fs panic from previous error\n");
+        if (test_opt(sb, ERRORS_RO)) {
+                printk("Remounting filesystem read-only\n");
+                sb->s_flags |= MS_RDONLY;
+        }
+}
+
+void ext2_warning (struct super_block * sb, const char * function,
+                   const char * fmt, ...)
+{
+        va_list args;
+
+        va_start(args, fmt);
+        printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
+               sb->s_id, function);
+        vprintk(fmt, args);
+        printk("\n");
+        va_end(args);
+}
+
+void ext2_update_dynamic_rev(struct super_block *sb)
+{
+        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
+
+        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
+                return;
+
+        ext2_warning(sb, __FUNCTION__,
+                     "updating to rev %d because of new feature flag, "
+                     "running e2fsck is recommended",
+                     EXT2_DYNAMIC_REV);
+
+        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
+        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
+        es->s_rev_level = cpu_to_le32(EXT2_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.
+         */
+}
+
+static void ext2_put_super (struct super_block * sb)
+{
+        int db_count;
+        int i;
+        struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+        ext2_xattr_put_super(sb);
+        if (!(sb->s_flags & MS_RDONLY)) {
+                struct ext2_super_block *es = sbi->s_es;
+
+                es->s_state = cpu_to_le16(sbi->s_mount_state);
+                ext2_sync_super(sb, es);
+        }
+        db_count = sbi->s_gdb_count;
+        for (i = 0; i < db_count; i++)
+                if (sbi->s_group_desc[i])
+                        brelse (sbi->s_group_desc[i]);
+        kfree(sbi->s_group_desc);
+        kfree(sbi->s_debts);
+        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);
+        sb->s_fs_info = NULL;
+        kfree(sbi);
+
+        return;
+}
+
+static kmem_cache_t * ext2_inode_cachep;
+
+static struct inode *ext2_alloc_inode(struct super_block *sb)
+{
+        struct ext2_inode_info *ei;
+        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
+        if (!ei)
+                return NULL;
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+        ei->i_acl = EXT2_ACL_NOT_CACHED;
+        ei->i_default_acl = EXT2_ACL_NOT_CACHED;
+#endif
+        ei->vfs_inode.i_version = 1;
+        return &ei->vfs_inode;
+}
+
+static void ext2_destroy_inode(struct inode *inode)
+{
+        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
+}
+
+static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
+{
+        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
+
+        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+            SLAB_CTOR_CONSTRUCTOR) {
+                rwlock_init(&ei->i_meta_lock);
+#ifdef CONFIG_EXT2_FS_XATTR
+                init_rwsem(&ei->xattr_sem);
+#endif
+                inode_init_once(&ei->vfs_inode);
+        }
+}
+ 
+static int init_inodecache(void)
+{
+        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
+                                             sizeof(struct ext2_inode_info),
+                                             0, SLAB_RECLAIM_ACCOUNT,
+                                             init_once, NULL);
+        if (ext2_inode_cachep == NULL)
+                return -ENOMEM;
+        return 0;
+}
+
+static void destroy_inodecache(void)
+{
+        if (kmem_cache_destroy(ext2_inode_cachep))
+                printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
+}
+
+static void ext2_clear_inode(struct inode *inode)
+{
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+        struct ext2_inode_info *ei = EXT2_I(inode);
+
+        if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
+                posix_acl_release(ei->i_acl);
+                ei->i_acl = EXT2_ACL_NOT_CACHED;
+        }
+        if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
+                posix_acl_release(ei->i_default_acl);
+                ei->i_default_acl = EXT2_ACL_NOT_CACHED;
+        }
+#endif
+        if (!is_bad_inode(inode))
+                ext2_discard_prealloc(inode);
+}
+
+
+#ifdef CONFIG_QUOTA
+static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
+static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
+#endif
+
+static struct super_operations ext2_sops = {
+        .alloc_inode    = ext2_alloc_inode,
+        .destroy_inode  = ext2_destroy_inode,
+        .read_inode     = ext2_read_inode,
+        .write_inode    = ext2_write_inode,
+        .delete_inode   = ext2_delete_inode,
+        .put_super      = ext2_put_super,
+        .write_super    = ext2_write_super,
+        .statfs         = ext2_statfs,
+        .remount_fs     = ext2_remount,
+        .clear_inode    = ext2_clear_inode,
+#ifdef CONFIG_QUOTA
+        .quota_read     = ext2_quota_read,
+        .quota_write    = ext2_quota_write,
+#endif
+};
+
+/* Yes, most of these are left as NULL!!
+ * A NULL value implies the default, which works with ext2-like file
+ * systems, but can be improved upon.
+ * Currently only get_parent is required.
+ */
+struct dentry *ext2_get_parent(struct dentry *child);
+static struct export_operations ext2_export_ops = {
+        .get_parent = ext2_get_parent,
+};
+
+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("EXT2-fs: Invalid sb specification: %s\n",
+                       (char *) *data);
+                return 1;
+        }
+        if (*options == ',')
+                options++;
+        *data = (void *) options;
+        return sb_block;
+}
+
+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_nobh,
+        Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
+        Opt_ignore, Opt_err,
+};
+
+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, "check=none"},
+        {Opt_nocheck, "nocheck"},
+        {Opt_check, "check"},
+        {Opt_debug, "debug"},
+        {Opt_oldalloc, "oldalloc"},
+        {Opt_orlov, "orlov"},
+        {Opt_nobh, "nobh"},
+        {Opt_user_xattr, "user_xattr"},
+        {Opt_nouser_xattr, "nouser_xattr"},
+        {Opt_acl, "acl"},
+        {Opt_noacl, "noacl"},
+        {Opt_ignore, "grpquota"},
+        {Opt_ignore, "noquota"},
+        {Opt_ignore, "quota"},
+        {Opt_ignore, "usrquota"},
+        {Opt_err, NULL}
+};
+
+static int parse_options (char * options,
+                          struct ext2_sb_info *sbi)
+{
+        char * p;
+        substring_t args[MAX_OPT_ARGS];
+        unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
+        int option;
+
+        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:
+                        kind = EXT2_MOUNT_ERRORS_PANIC;
+                        break;
+                case Opt_err_ro:
+                        kind = EXT2_MOUNT_ERRORS_RO;
+                        break;
+                case Opt_err_cont:
+                        kind = EXT2_MOUNT_ERRORS_CONT;
+                        break;
+                case Opt_nouid32:
+                        set_opt (sbi->s_mount_opt, NO_UID32);
+                        break;
+                case Opt_check:
+#ifdef CONFIG_EXT2_CHECK
+                        set_opt (sbi->s_mount_opt, CHECK);
+#else
+                        printk("EXT2 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;
+                case Opt_nobh:
+                        set_opt (sbi->s_mount_opt, NOBH);
+                        break;
+#ifdef CONFIG_EXT2_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("EXT2 (no)user_xattr options not supported\n");
+                        break;
+#endif
+#ifdef CONFIG_EXT2_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("EXT2 (no)acl options not supported\n");
+                        break;
+#endif
+                case Opt_ignore:
+                        break;
+                default:
+                        return 0;
+                }
+        }
+        sbi->s_mount_opt |= kind;
+        return 1;
+}
+
+static int ext2_setup_super (struct super_block * sb,
+                              struct ext2_super_block * es,
+                              int read_only)
+{
+        int res = 0;
+        struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
+                printk ("EXT2-fs warning: revision level too high, "
+                        "forcing read-only mode\n");
+                res = MS_RDONLY;
+        }
+        if (read_only)
+                return res;
+        if (!(sbi->s_mount_state & EXT2_VALID_FS))
+                printk ("EXT2-fs warning: mounting unchecked fs, "
+                        "running e2fsck is recommended\n");
+        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
+                printk ("EXT2-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 ("EXT2-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 ("EXT2-fs warning: checktime reached, "
+                        "running e2fsck is recommended\n");
+        if (!le16_to_cpu(es->s_max_mnt_count))
+                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
+        es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
+        ext2_write_super(sb);
+        if (test_opt (sb, DEBUG))
+                printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
+                        "bpg=%lu, ipg=%lu, mo=%04lx]\n",
+                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
+                        sbi->s_frag_size,
+                        sbi->s_groups_count,
+                        EXT2_BLOCKS_PER_GROUP(sb),
+                        EXT2_INODES_PER_GROUP(sb),
+                        sbi->s_mount_opt);
+#ifdef CONFIG_EXT2_CHECK
+        if (test_opt (sb, CHECK)) {
+                ext2_check_blocks_bitmap (sb);
+                ext2_check_inodes_bitmap (sb);
+        }
+#endif
+        return res;
+}
+
+static int ext2_check_descriptors (struct super_block * sb)
+{
+        int i;
+        int desc_block = 0;
+        struct ext2_sb_info *sbi = EXT2_SB(sb);
+        unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
+        struct ext2_group_desc * gdp = NULL;
+
+        ext2_debug ("Checking group descriptors");
+
+        for (i = 0; i < sbi->s_groups_count; i++)
+        {
+                if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
+                        gdp = (struct ext2_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 + EXT2_BLOCKS_PER_GROUP(sb))
+                {
+                        ext2_error (sb, "ext2_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 + EXT2_BLOCKS_PER_GROUP(sb))
+                {
+                        ext2_error (sb, "ext2_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 + EXT2_BLOCKS_PER_GROUP(sb))
+                {
+                        ext2_error (sb, "ext2_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 += EXT2_BLOCKS_PER_GROUP(sb);
+                gdp++;
+        }
+        return 1;
+}
+
+#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 ext2_max_size(int bits)
+{
+        loff_t res = EXT2_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 ext2_sb_info *sbi = EXT2_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 (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
+            nr < first_meta_bg)
+                return (logic_sb_block + nr + 1);
+        bg = sbi->s_desc_per_block * nr;
+        if (ext2_bg_has_super(sb, bg))
+                has_super = 1;
+        return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
+}
+
+static int ext2_fill_super(struct super_block *sb, void *data, int silent)
+{
+        struct buffer_head * bh;
+        struct ext2_sb_info * sbi;
+        struct ext2_super_block * es;
+        struct inode *root;
+        unsigned long block;
+        unsigned long sb_block = get_sb_block(&data);
+        unsigned long logic_sb_block;
+        unsigned long offset = 0;
+        unsigned long def_mount_opts;
+        int blocksize = BLOCK_SIZE;
+        int db_count;
+        int i, j;
+        __le32 features;
+
+        sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
+        if (!sbi)
+                return -ENOMEM;
+        sb->s_fs_info = sbi;
+        memset(sbi, 0, sizeof(*sbi));
+
+        /*
+         * See what the current blocksize for the device is, and
+         * use that as the blocksize.  Otherwise (or if the blocksize
+         * is smaller than the default) use the default.
+         * This is important for devices that have a hardware
+         * sectorsize that is larger than the default.
+         */
+        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
+        if (!blocksize) {
+                printk ("EXT2-fs: unable to set blocksize\n");
+                goto failed_sbi;
+        }
+
+        /*
+         * If the superblock doesn't start on a hardware sector boundary,
+         * calculate the offset.  
+         */
+        if (blocksize != BLOCK_SIZE) {
+                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
+                offset = (sb_block*BLOCK_SIZE) % blocksize;
+        } else {
+                logic_sb_block = sb_block;
+        }
+
+        if (!(bh = sb_bread(sb, logic_sb_block))) {
+                printk ("EXT2-fs: unable to read superblock\n");
+                goto failed_sbi;
+        }
+        /*
+         * Note: s_es must be initialized as soon as possible because
+         *       some ext2 macro-instructions depend on its value
+         */
+        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
+        sbi->s_es = es;
+        sb->s_magic = le16_to_cpu(es->s_magic);
+
+        if (sb->s_magic != EXT2_SUPER_MAGIC)
+                goto cantfind_ext2;
+
+        /* Set defaults before we parse the mount options */
+        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+        if (def_mount_opts & EXT2_DEFM_DEBUG)
+                set_opt(sbi->s_mount_opt, DEBUG);
+        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
+                set_opt(sbi->s_mount_opt, GRPID);
+        if (def_mount_opts & EXT2_DEFM_UID16)
+                set_opt(sbi->s_mount_opt, NO_UID32);
+        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
+                set_opt(sbi->s_mount_opt, XATTR_USER);
+        if (def_mount_opts & EXT2_DEFM_ACL)
+                set_opt(sbi->s_mount_opt, POSIX_ACL);
+        
+        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
+                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
+        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_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);
+        
+        if (!parse_options ((char *) data, sbi))
+                goto failed_mount;
+
+        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
+                 MS_POSIXACL : 0);
+
+        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
+            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
+             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
+             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
+                printk("EXT2-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 = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
+        if (features) {
+                printk("EXT2-fs: %s: couldn't mount because of "
+                       "unsupported optional features (%x).\n",
+                       sb->s_id, le32_to_cpu(features));
+                goto failed_mount;
+        }
+        if (!(sb->s_flags & MS_RDONLY) &&
+            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
+                printk("EXT2-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(sbi->s_es->s_log_block_size);
+
+        /* If the blocksize doesn't match, re-read the thing.. */
+        if (sb->s_blocksize != blocksize) {
+                brelse(bh);
+
+                if (!sb_set_blocksize(sb, blocksize)) {
+                        printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
+                        goto failed_sbi;
+                }
+
+                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
+                offset = (sb_block*BLOCK_SIZE) % blocksize;
+                bh = sb_bread(sb, logic_sb_block);
+                if(!bh) {
+                        printk("EXT2-fs: Couldn't read superblock on "
+                               "2nd try.\n");
+                        goto failed_sbi;
+                }
+                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
+                sbi->s_es = es;
+                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
+                        printk ("EXT2-fs: Magic mismatch, very weird !\n");
+                        goto failed_mount;
+                }
+        }
+
+        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
+
+        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
+                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
+                sbi->s_first_ino = EXT2_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 < EXT2_GOOD_OLD_INODE_SIZE) ||
+                    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
+                    (sbi->s_inode_size > blocksize)) {
+                        printk ("EXT2-fs: unsupported inode size: %d\n",
+                                sbi->s_inode_size);
+                        goto failed_mount;
+                }
+        }
+
+        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
+                                   le32_to_cpu(es->s_log_frag_size);
+        if (sbi->s_frag_size == 0)
+                goto cantfind_ext2;
+        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
+
+        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 (EXT2_INODE_SIZE(sb) == 0)
+                goto cantfind_ext2;
+        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
+        if (sbi->s_inodes_per_block == 0)
+                goto cantfind_ext2;
+        sbi->s_itb_per_group = sbi->s_inodes_per_group /
+                                        sbi->s_inodes_per_block;
+        sbi->s_desc_per_block = sb->s_blocksize /
+                                        sizeof (struct ext2_group_desc);
+        sbi->s_sbh = bh;
+        sbi->s_mount_state = le16_to_cpu(es->s_state);
+        sbi->s_addr_per_block_bits =
+                log2 (EXT2_ADDR_PER_BLOCK(sb));
+        sbi->s_desc_per_block_bits =
+                log2 (EXT2_DESC_PER_BLOCK(sb));
+
+        if (sb->s_magic != EXT2_SUPER_MAGIC)
+                goto cantfind_ext2;
+
+        if (sb->s_blocksize != bh->b_size) {
+                if (!silent)
+                        printk ("VFS: Unsupported blocksize on dev "
+                                "%s.\n", sb->s_id);
+                goto failed_mount;
+        }
+
+        if (sb->s_blocksize != sbi->s_frag_size) {
+                printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
+                        sbi->s_frag_size, sb->s_blocksize);
+                goto failed_mount;
+        }
+
+        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
+                printk ("EXT2-fs: #blocks per group too big: %lu\n",
+                        sbi->s_blocks_per_group);
+                goto failed_mount;
+        }
+        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
+                printk ("EXT2-fs: #fragments per group too big: %lu\n",
+                        sbi->s_frags_per_group);
+                goto failed_mount;
+        }
+        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
+                printk ("EXT2-fs: #inodes per group too big: %lu\n",
+                        sbi->s_inodes_per_group);
+                goto failed_mount;
+        }
+
+        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
+                goto cantfind_ext2;
+        sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
+                                        le32_to_cpu(es->s_first_data_block) +
+                                       EXT2_BLOCKS_PER_GROUP(sb) - 1) /
+                                       EXT2_BLOCKS_PER_GROUP(sb);
+        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
+                   EXT2_DESC_PER_BLOCK(sb);
+        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
+        if (sbi->s_group_desc == NULL) {
+                printk ("EXT2-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);
+        sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
+                               GFP_KERNEL);
+        if (!sbi->s_debts) {
+                printk ("EXT2-fs: not enough memory\n");
+                goto failed_mount_group_desc;
+        }
+        memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
+        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]) {
+                        for (j = 0; j < i; j++)
+                                brelse (sbi->s_group_desc[j]);
+                        printk ("EXT2-fs: unable to read group descriptors\n");
+                        goto failed_mount_group_desc;
+                }
+        }
+        if (!ext2_check_descriptors (sb)) {
+                printk ("EXT2-fs: group descriptors corrupted!\n");
+                db_count = i;
+                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);
+        /*
+         * set up enough so that it can read an inode
+         */
+        sb->s_op = &ext2_sops;
+        sb->s_export_op = &ext2_export_ops;
+        sb->s_xattr = ext2_xattr_handlers;
+        root = iget(sb, EXT2_ROOT_INO);
+        sb->s_root = d_alloc_root(root);
+        if (!sb->s_root) {
+                iput(root);
+                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
+                goto failed_mount2;
+        }
+        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+                dput(sb->s_root);
+                sb->s_root = NULL;
+                printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
+                goto failed_mount2;
+        }
+        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
+                ext2_warning(sb, __FUNCTION__,
+                        "mounting ext3 filesystem as ext2\n");
+        ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
+        percpu_counter_mod(&sbi->s_freeblocks_counter,
+                                ext2_count_free_blocks(sb));
+        percpu_counter_mod(&sbi->s_freeinodes_counter,
+                                ext2_count_free_inodes(sb));
+        percpu_counter_mod(&sbi->s_dirs_counter,
+                                ext2_count_dirs(sb));
+        return 0;
+
+cantfind_ext2:
+        if (!silent)
+                printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
+                       sb->s_id);
+        goto failed_mount;
+
+failed_mount2:
+        for (i = 0; i < db_count; i++)
+                brelse(sbi->s_group_desc[i]);
+failed_mount_group_desc:
+        kfree(sbi->s_group_desc);
+        kfree(sbi->s_debts);
+failed_mount:
+        brelse(bh);
+failed_sbi:
+        sb->s_fs_info = NULL;
+        kfree(sbi);
+        return -EINVAL;
+}
+
+static void ext2_commit_super (struct super_block * sb,
+                               struct ext2_super_block * es)
+{
+        es->s_wtime = cpu_to_le32(get_seconds());
+        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
+        sb->s_dirt = 0;
+}
+
+static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
+{
+        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
+        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
+        es->s_wtime = cpu_to_le32(get_seconds());
+        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
+        sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
+        sb->s_dirt = 0;
+}
+
+/*
+ * In the second extended file system, it is not necessary to
+ * write the super block since we use a mapping of the
+ * disk super block in a buffer.
+ *
+ * However, this function is still used to set the fs valid
+ * flags to 0.  We need to set this flag to 0 since the fs
+ * may have been checked while mounted and e2fsck may have
+ * set s_state to EXT2_VALID_FS after some corrections.
+ */
+
+void ext2_write_super (struct super_block * sb)
+{
+        struct ext2_super_block * es;
+        lock_kernel();
+        if (!(sb->s_flags & MS_RDONLY)) {
+                es = EXT2_SB(sb)->s_es;
+
+                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
+                        ext2_debug ("setting valid to 0\n");
+                        es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
+                                                  ~EXT2_VALID_FS);
+                        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
+                        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
+                        es->s_mtime = cpu_to_le32(get_seconds());
+                        ext2_sync_super(sb, es);
+                } else
+                        ext2_commit_super (sb, es);
+        }
+        sb->s_dirt = 0;
+        unlock_kernel();
+}
+
+static int ext2_remount (struct super_block * sb, int * flags, char * data)
+{
+        struct ext2_sb_info * sbi = EXT2_SB(sb);
+        struct ext2_super_block * es;
+
+        /*
+         * Allow the "check" option to be passed as a remount option.
+         */
+        if (!parse_options (data, sbi))
+                return -EINVAL;
+
+        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
+
+        es = sbi->s_es;
+        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
+                return 0;
+        if (*flags & MS_RDONLY) {
+                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
+                    !(sbi->s_mount_state & EXT2_VALID_FS))
+                        return 0;
+                /*
+                 * OK, we are remounting a valid rw partition rdonly, so set
+                 * the rdonly flag and then mark the partition as valid again.
+                 */
+                es->s_state = cpu_to_le16(sbi->s_mount_state);
+                es->s_mtime = cpu_to_le32(get_seconds());
+        } else {
+                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
+                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
+                if (ret) {
+                        printk("EXT2-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.)
+                 */
+                sbi->s_mount_state = le16_to_cpu(es->s_state);
+                if (!ext2_setup_super (sb, es, 0))
+                        sb->s_flags &= ~MS_RDONLY;
+        }
+        ext2_sync_super(sb, es);
+        return 0;
+}
+
+static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
+{
+        struct ext2_sb_info *sbi = EXT2_SB(sb);
+        unsigned long overhead;
+        int i;
+
+        if (test_opt (sb, MINIX_DF))
+                overhead = 0;
+        else {
+                /*
+                 * Compute the overhead (FS structures)
+                 */
+
+                /*
+                 * All of the blocks before first_data_block are
+                 * overhead
+                 */
+                overhead = le32_to_cpu(sbi->s_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 < sbi->s_groups_count; i++)
+                        overhead += ext2_bg_has_super(sb, i) +
+                                ext2_bg_num_gdb(sb, i);
+
+                /*
+                 * Every block group has an inode bitmap, a block
+                 * bitmap, and an inode table.
+                 */
+                overhead += (sbi->s_groups_count *
+                             (2 + sbi->s_itb_per_group));
+        }
+
+        buf->f_type = EXT2_SUPER_MAGIC;
+        buf->f_bsize = sb->s_blocksize;
+        buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
+        buf->f_bfree = ext2_count_free_blocks(sb);
+        buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
+        if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
+                buf->f_bavail = 0;
+        buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
+        buf->f_ffree = ext2_count_free_inodes (sb);
+        buf->f_namelen = EXT2_NAME_LEN;
+        return 0;
+}
+
+static struct super_block *ext2_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, ext2_fill_super);
+}
+
+#ifdef CONFIG_QUOTA
+
+/* 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 ext2_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 >> EXT2_BLOCK_SIZE_BITS(sb);
+        int err = 0;
+        int offset = off & (sb->s_blocksize - 1);
+        int tocopy;
+        size_t toread;
+        struct buffer_head tmp_bh;
+        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;
+
+                tmp_bh.b_state = 0;
+                err = ext2_get_block(inode, blk, &tmp_bh, 0);
+                if (err)
+                        return err;
+                if (!buffer_mapped(&tmp_bh))    /* A hole? */
+                        memset(data, 0, tocopy);
+                else {
+                        bh = sb_bread(sb, tmp_bh.b_blocknr);
+                        if (!bh)
+                                return -EIO;
+                        memcpy(data, bh->b_data+offset, tocopy);
+                        brelse(bh);
+                }
+                offset = 0;
+                toread -= tocopy;
+                data += tocopy;
+                blk++;
+        }
+        return len;
+}
+
+/* Write to quotafile */
+static ssize_t ext2_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 >> EXT2_BLOCK_SIZE_BITS(sb);
+        int err = 0;
+        int offset = off & (sb->s_blocksize - 1);
+        int tocopy;
+        size_t towrite = len;
+        struct buffer_head tmp_bh;
+        struct buffer_head *bh;
+
+        down(&inode->i_sem);
+        while (towrite > 0) {
+                tocopy = sb->s_blocksize - offset < towrite ?
+                                sb->s_blocksize - offset : towrite;
+
+                tmp_bh.b_state = 0;
+                err = ext2_get_block(inode, blk, &tmp_bh, 1);
+                if (err)
+                        goto out;
+                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
+                        bh = sb_bread(sb, tmp_bh.b_blocknr);
+                else
+                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
+                if (!bh) {
+                        err = -EIO;
+                        goto out;
+                }
+                lock_buffer(bh);
+                memcpy(bh->b_data+offset, data, tocopy);
+                flush_dcache_page(bh->b_page);
+                set_buffer_uptodate(bh);
+                mark_buffer_dirty(bh);
+                unlock_buffer(bh);
+                brelse(bh);
+                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);
+        inode->i_version++;
+        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+        mark_inode_dirty(inode);
+        up(&inode->i_sem);
+        return len - towrite;
+}
+
+#endif
+
+static struct file_system_type ext2_fs_type = {
+        .owner          = THIS_MODULE,
+        .name           = "ext2",
+        .get_sb         = ext2_get_sb,
+        .kill_sb        = kill_block_super,
+        .fs_flags       = FS_REQUIRES_DEV,
+};
+
+static int __init init_ext2_fs(void)
+{
+        int err = init_ext2_xattr();
+        if (err)
+                return err;
+        err = init_inodecache();
+        if (err)
+                goto out1;
+        err = register_filesystem(&ext2_fs_type);
+        if (err)
+                goto out;
+        return 0;
+out:
+        destroy_inodecache();
+out1:
+        exit_ext2_xattr();
+        return err;
+}
+
+static void __exit exit_ext2_fs(void)
+{
+        unregister_filesystem(&ext2_fs_type);
+        destroy_inodecache();
+        exit_ext2_xattr();
+}
+
+module_init(init_ext2_fs)
+module_exit(exit_ext2_fs)