super.c

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/*
 *  linux/fs/ext3/super.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card ([email protected])
 * 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 ([email protected]), 1995
 */

#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/parser.h>
#include <linux/exportfs.h>
#include <linux/statfs.h>
#include <linux/random.h>
#include <linux/mount.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/log2.h>
#include <linux/cleancache.h>

#include <asm/uaccess.h>

#define CREATE_TRACE_POINTS

#include "ext3.h"
#include "xattr.h"
#include "acl.h"
#include "namei.h"

#ifdef CONFIG_EXT3_DEFAULTS_TO_ORDERED
  #define EXT3_MOUNT_DEFAULT_DATA_MODE EXT3_MOUNT_ORDERED_DATA
#else
  #define EXT3_MOUNT_DEFAULT_DATA_MODE EXT3_MOUNT_WRITEBACK_DATA
#endif

static int ext3_load_journal(struct super_block *, struct ext3_super_block *,
                 unsigned long journal_devnum);
static int ext3_create_journal(struct super_block *, struct ext3_super_block *,
                   unsigned int);
static int 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 dentry * dentry, struct kstatfs * buf);
static int ext3_unfreeze(struct super_block *sb);
static int ext3_freeze(struct super_block *sb);

/*
 * Wrappers for journal_start/end.
 */
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, __func__,
               "Detected aborted journal");
        return ERR_PTR(-EROFS);
    }

    return journal_start(journal, nblocks);
}

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 "EXT3-fs: %s: aborting transaction: %s in %s\n",
        caller, errstr, err_fn);

    journal_abort_handle(handle);
}

void ext3_msg(struct super_block *sb, const char *prefix,
        const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    printk("%sEXT3-fs (%s): %pV\n", prefix, sb->s_id, &vaf);

    va_end(args);
}

/* 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 complain 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_CONT)) {
        journal_t *journal = EXT3_SB(sb)->s_journal;

        set_opt(EXT3_SB(sb)->s_mount_opt, ABORT);
        if (journal)
            journal_abort(journal, -EIO);
    }
    if (test_opt (sb, ERRORS_RO)) {
        ext3_msg(sb, KERN_CRIT,
            "error: remounting filesystem read-only");
        sb->s_flags |= MS_RDONLY;
    }
    ext3_commit_super(sb, es, 1);
    if (test_opt(sb, ERRORS_PANIC))
        panic("EXT3-fs (%s): panic forced after error\n",
            sb->s_id);
}

void ext3_error(struct super_block *sb, const char *function,
        const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    printk(KERN_CRIT "EXT3-fs error (device %s): %s: %pV\n",
           sb->s_id, function, &vaf);

    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;

    /* Special case: if the error is EROFS, and we're not already
     * inside a transaction, then there's really no point in logging
     * an error. */
    if (errno == -EROFS && journal_current_handle() == NULL &&
        (sb->s_flags & MS_RDONLY))
        return;

    errstr = ext3_decode_error(sb, errno, nbuf);
    ext3_msg(sb, KERN_CRIT, "error in %s: %s", 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, ...)
{
    struct va_format vaf;
    va_list args;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    printk(KERN_CRIT "EXT3-fs (%s): error: %s: %pV\n",
           sb->s_id, function, &vaf);

    va_end(args);

    if (test_opt(sb, ERRORS_PANIC))
        panic("EXT3-fs: panic from previous error\n");

    if (sb->s_flags & MS_RDONLY)
        return;

    ext3_msg(sb, KERN_CRIT,
        "error: remounting filesystem read-only");
    EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
    sb->s_flags |= MS_RDONLY;
    set_opt(EXT3_SB(sb)->s_mount_opt, ABORT);
    if (EXT3_SB(sb)->s_journal)
        journal_abort(EXT3_SB(sb)->s_journal, -EIO);
}

void ext3_warning(struct super_block *sb, const char *function,
          const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;

    va_start(args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    printk(KERN_WARNING "EXT3-fs (%s): warning: %s: %pV\n",
           sb->s_id, function, &vaf);

    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_msg(sb, KERN_WARNING,
        "warning: 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 super_block *sb)
{
    struct block_device *bdev;
    char b[BDEVNAME_SIZE];

    bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
    if (IS_ERR(bdev))
        goto fail;
    return bdev;

fail:
    ext3_msg(sb, "error: failed to open journal device %s: %ld",
        __bdevname(dev, b), PTR_ERR(bdev));

    return NULL;
}

/*
 * Release the journal device
 */
static int ext3_blkdev_put(struct block_device *bdev)
{
    return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
}

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;

    ext3_msg(sb, KERN_ERR, "error: sb orphan head is %d",
           le32_to_cpu(sbi->s_es->s_last_orphan));

    ext3_msg(sb, KERN_ERR, "sb_info orphan list:");
    list_for_each(l, &sbi->s_orphan) {
        struct inode *inode = orphan_list_entry(l);
        ext3_msg(sb, KERN_ERR, "  "
               "inode %s:%lu 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, err;

    dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
    ext3_xattr_put_super(sb);
    err = journal_destroy(sbi->s_journal);
    sbi->s_journal = NULL;
    if (err < 0)
        ext3_abort(sb, __func__, "Couldn't clean up the 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);
    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);
        ext3_blkdev_remove(sbi);
    }
    sb->s_fs_info = NULL;
    kfree(sbi->s_blockgroup_lock);
    kfree(sbi);
}

static struct kmem_cache *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, GFP_NOFS);
    if (!ei)
        return NULL;
    ei->i_block_alloc_info = NULL;
    ei->vfs_inode.i_version = 1;
    atomic_set(&ei->i_datasync_tid, 0);
    atomic_set(&ei->i_sync_tid, 0);
    return &ei->vfs_inode;
}

static int ext3_drop_inode(struct inode *inode)
{
    int drop = generic_drop_inode(inode);

    trace_ext3_drop_inode(inode, drop);
    return drop;
}

static void ext3_i_callback(struct rcu_head *head)
{
    struct inode *inode = container_of(head, struct inode, i_rcu);
    kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
}

static void ext3_destroy_inode(struct inode *inode)
{
    if (!list_empty(&(EXT3_I(inode)->i_orphan))) {
        printk("EXT3 Inode %p: orphan list check failed!\n",
            EXT3_I(inode));
        print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
                EXT3_I(inode), sizeof(struct ext3_inode_info),
                false);
        dump_stack();
    }
    call_rcu(&inode->i_rcu, ext3_i_callback);
}

static void init_once(void *foo)
{
    struct ext3_inode_info *ei = (struct ext3_inode_info *) foo;

    INIT_LIST_HEAD(&ei->i_orphan);
#ifdef CONFIG_EXT3_FS_XATTR
    init_rwsem(&ei->xattr_sem);
#endif
    mutex_init(&ei->truncate_mutex);
    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|
                        SLAB_MEM_SPREAD),
                         init_once);
    if (ext3_inode_cachep == NULL)
        return -ENOMEM;
    return 0;
}

static void destroy_inodecache(void)
{
    /*
     * Make sure all delayed rcu free inodes are flushed before we
     * destroy cache.
     */
    rcu_barrier();
    kmem_cache_destroy(ext3_inode_cachep);
}

static inline void ext3_show_quota_options(struct seq_file *seq, struct super_block *sb)
{
#if defined(CONFIG_QUOTA)
    struct ext3_sb_info *sbi = EXT3_SB(sb);

    if (sbi->s_jquota_fmt) {
        char *fmtname = "";

        switch (sbi->s_jquota_fmt) {
        case QFMT_VFS_OLD:
            fmtname = "vfsold";
            break;
        case QFMT_VFS_V0:
            fmtname = "vfsv0";
            break;
        case QFMT_VFS_V1:
            fmtname = "vfsv1";
            break;
        }
        seq_printf(seq, ",jqfmt=%s", fmtname);
    }

    if (sbi->s_qf_names[USRQUOTA])
        seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);

    if (sbi->s_qf_names[GRPQUOTA])
        seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);

    if (test_opt(sb, USRQUOTA))
        seq_puts(seq, ",usrquota");

    if (test_opt(sb, GRPQUOTA))
        seq_puts(seq, ",grpquota");
#endif
}

static char *data_mode_string(unsigned long mode)
{
    switch (mode) {
    case EXT3_MOUNT_JOURNAL_DATA:
        return "journal";
    case EXT3_MOUNT_ORDERED_DATA:
        return "ordered";
    case EXT3_MOUNT_WRITEBACK_DATA:
        return "writeback";
    }
    return "unknown";
}

/*
 * Show an option if
 *  - it's set to a non-default value OR
 *  - if the per-sb default is different from the global default
 */
static int ext3_show_options(struct seq_file *seq, struct dentry *root)
{
    struct super_block *sb = root->d_sb;
    struct ext3_sb_info *sbi = EXT3_SB(sb);
    struct ext3_super_block *es = sbi->s_es;
    unsigned long def_mount_opts;

    def_mount_opts = le32_to_cpu(es->s_default_mount_opts);

    if (sbi->s_sb_block != 1)
        seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
    if (test_opt(sb, MINIX_DF))
        seq_puts(seq, ",minixdf");
    if (test_opt(sb, GRPID))
        seq_puts(seq, ",grpid");
    if (!test_opt(sb, GRPID) && (def_mount_opts & EXT3_DEFM_BSDGROUPS))
        seq_puts(seq, ",nogrpid");
    if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT3_DEF_RESUID)) ||
        le16_to_cpu(es->s_def_resuid) != EXT3_DEF_RESUID) {
        seq_printf(seq, ",resuid=%u",
                from_kuid_munged(&init_user_ns, sbi->s_resuid));
    }
    if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT3_DEF_RESGID)) ||
        le16_to_cpu(es->s_def_resgid) != EXT3_DEF_RESGID) {
        seq_printf(seq, ",resgid=%u",
                from_kgid_munged(&init_user_ns, sbi->s_resgid));
    }
    if (test_opt(sb, ERRORS_RO)) {
        int def_errors = le16_to_cpu(es->s_errors);

        if (def_errors == EXT3_ERRORS_PANIC ||
            def_errors == EXT3_ERRORS_CONTINUE) {
            seq_puts(seq, ",errors=remount-ro");
        }
    }
    if (test_opt(sb, ERRORS_CONT))
        seq_puts(seq, ",errors=continue");
    if (test_opt(sb, ERRORS_PANIC))
        seq_puts(seq, ",errors=panic");
    if (test_opt(sb, NO_UID32))
        seq_puts(seq, ",nouid32");
    if (test_opt(sb, DEBUG))
        seq_puts(seq, ",debug");
#ifdef CONFIG_EXT3_FS_XATTR
    if (test_opt(sb, XATTR_USER))
        seq_puts(seq, ",user_xattr");
    if (!test_opt(sb, XATTR_USER) &&
        (def_mount_opts & EXT3_DEFM_XATTR_USER)) {
        seq_puts(seq, ",nouser_xattr");
    }
#endif
#ifdef CONFIG_EXT3_FS_POSIX_ACL
    if (test_opt(sb, POSIX_ACL))
        seq_puts(seq, ",acl");
    if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT3_DEFM_ACL))
        seq_puts(seq, ",noacl");
#endif
    if (!test_opt(sb, RESERVATION))
        seq_puts(seq, ",noreservation");
    if (sbi->s_commit_interval) {
        seq_printf(seq, ",commit=%u",
               (unsigned) (sbi->s_commit_interval / HZ));
    }

    /*
     * Always display barrier state so it's clear what the status is.
     */
    seq_puts(seq, ",barrier=");
    seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
    seq_printf(seq, ",data=%s", data_mode_string(test_opt(sb, DATA_FLAGS)));
    if (test_opt(sb, DATA_ERR_ABORT))
        seq_puts(seq, ",data_err=abort");

    if (test_opt(sb, NOLOAD))
        seq_puts(seq, ",norecovery");

    ext3_show_quota_options(seq, sb);

    return 0;
}


static struct inode *ext3_nfs_get_inode(struct super_block *sb,
        u64 ino, u32 generation)
{
    struct inode *inode;

    if (ino < EXT3_FIRST_INO(sb) && ino != EXT3_ROOT_INO)
        return ERR_PTR(-ESTALE);
    if (ino > le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count))
        return ERR_PTR(-ESTALE);

    /* iget isn't really right if the inode is currently unallocated!!
     *
     * ext3_read_inode will return a bad_inode if the inode had been
     * deleted, so we should be safe.
     *
     * Currently we don't know the generation for parent directory, so
     * a generation of 0 means "accept any"
     */
    inode = ext3_iget(sb, ino);
    if (IS_ERR(inode))
        return ERR_CAST(inode);
    if (generation && inode->i_generation != generation) {
        iput(inode);
        return ERR_PTR(-ESTALE);
    }

    return inode;
}

static struct dentry *ext3_fh_to_dentry(struct super_block *sb, struct fid *fid,
        int fh_len, int fh_type)
{
    return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
                    ext3_nfs_get_inode);
}

static struct dentry *ext3_fh_to_parent(struct super_block *sb, struct fid *fid,
        int fh_len, int fh_type)
{
    return generic_fh_to_parent(sb, fid, fh_len, fh_type,
                    ext3_nfs_get_inode);
}

/*
 * Try to release metadata pages (indirect blocks, directories) which are
 * mapped via the block device.  Since these pages could have journal heads
 * which would prevent try_to_free_buffers() from freeing them, we must use
 * jbd layer's try_to_free_buffers() function to release them.
 */
static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
                 gfp_t wait)
{
    journal_t *journal = EXT3_SB(sb)->s_journal;

    WARN_ON(PageChecked(page));
    if (!page_has_buffers(page))
        return 0;
    if (journal)
        return journal_try_to_free_buffers(journal, page, 
                           wait & ~__GFP_WAIT);
    return try_to_free_buffers(page);
}

#ifdef CONFIG_QUOTA
#define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
#define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))

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,
             struct path *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 const struct dquot_operations ext3_quota_operations = {
    .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,
    .alloc_dquot    = dquot_alloc,
    .destroy_dquot  = dquot_destroy,
};

static const struct quotactl_ops ext3_qctl_operations = {
    .quota_on   = ext3_quota_on,
    .quota_off  = dquot_quota_off,
    .quota_sync = dquot_quota_sync,
    .get_info   = dquot_get_dqinfo,
    .set_info   = dquot_set_dqinfo,
    .get_dqblk  = dquot_get_dqblk,
    .set_dqblk  = dquot_set_dqblk
};
#endif

static const struct super_operations ext3_sops = {
    .alloc_inode    = ext3_alloc_inode,
    .destroy_inode  = ext3_destroy_inode,
    .write_inode    = ext3_write_inode,
    .dirty_inode    = ext3_dirty_inode,
    .drop_inode = ext3_drop_inode,
    .evict_inode    = ext3_evict_inode,
    .put_super  = ext3_put_super,
    .sync_fs    = ext3_sync_fs,
    .freeze_fs  = ext3_freeze,
    .unfreeze_fs    = ext3_unfreeze,
    .statfs     = ext3_statfs,
    .remount_fs = ext3_remount,
    .show_options   = ext3_show_options,
#ifdef CONFIG_QUOTA
    .quota_read = ext3_quota_read,
    .quota_write    = ext3_quota_write,
#endif
    .bdev_try_to_free_page = bdev_try_to_free_page,
};

static const struct export_operations ext3_export_ops = {
    .fh_to_dentry = ext3_fh_to_dentry,
    .fh_to_parent = ext3_fh_to_parent,
    .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_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_bh,
    Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
    Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
    Opt_data_err_abort, Opt_data_err_ignore,
    Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
    Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
    Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
    Opt_resize, Opt_usrquota, Opt_grpquota
};

static const 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_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_noload, "norecovery"},
    {Opt_nobh, "nobh"},
    {Opt_bh, "bh"},
    {Opt_commit, "commit=%u"},
    {Opt_journal_update, "journal=update"},
    {Opt_journal_inum, "journal=%u"},
    {Opt_journal_dev, "journal_dev=%u"},
    {Opt_abort, "abort"},
    {Opt_data_journal, "data=journal"},
    {Opt_data_ordered, "data=ordered"},
    {Opt_data_writeback, "data=writeback"},
    {Opt_data_err_abort, "data_err=abort"},
    {Opt_data_err_ignore, "data_err=ignore"},
    {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_jqfmt_vfsv1, "jqfmt=vfsv1"},
    {Opt_grpquota, "grpquota"},
    {Opt_noquota, "noquota"},
    {Opt_quota, "quota"},
    {Opt_usrquota, "usrquota"},
    {Opt_barrier, "barrier=%u"},
    {Opt_barrier, "barrier"},
    {Opt_nobarrier, "nobarrier"},
    {Opt_resize, "resize"},
    {Opt_err, NULL},
};

static ext3_fsblk_t get_sb_block(void **data, struct super_block *sb)
{
    ext3_fsblk_t    sb_block;
    char        *options = (char *) *data;

    if (!options || strncmp(options, "sb=", 3) != 0)
        return 1;   /* Default location */
    options += 3;
    /*todo: use simple_strtoll with >32bit ext3 */
    sb_block = simple_strtoul(options, &options, 0);
    if (*options && *options != ',') {
        ext3_msg(sb, "error: invalid sb specification: %s",
               (char *) *data);
        return 1;
    }
    if (*options == ',')
        options++;
    *data = (void *) options;
    return sb_block;
}

#ifdef CONFIG_QUOTA
static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
{
    struct ext3_sb_info *sbi = EXT3_SB(sb);
    char *qname;

    if (sb_any_quota_loaded(sb) &&
        !sbi->s_qf_names[qtype]) {
        ext3_msg(sb, KERN_ERR,
            "Cannot change journaled "
            "quota options when quota turned on");
        return 0;
    }
    qname = match_strdup(args);
    if (!qname) {
        ext3_msg(sb, KERN_ERR,
            "Not enough memory for storing quotafile name");
        return 0;
    }
    if (sbi->s_qf_names[qtype] &&
        strcmp(sbi->s_qf_names[qtype], qname)) {
        ext3_msg(sb, KERN_ERR,
            "%s quota file already specified", QTYPE2NAME(qtype));
        kfree(qname);
        return 0;
    }
    sbi->s_qf_names[qtype] = qname;
    if (strchr(sbi->s_qf_names[qtype], '/')) {
        ext3_msg(sb, KERN_ERR,
            "quotafile must be on filesystem root");
        kfree(sbi->s_qf_names[qtype]);
        sbi->s_qf_names[qtype] = NULL;
        return 0;
    }
    set_opt(sbi->s_mount_opt, QUOTA);
    return 1;
}

static int clear_qf_name(struct super_block *sb, int qtype) {

    struct ext3_sb_info *sbi = EXT3_SB(sb);

    if (sb_any_quota_loaded(sb) &&
        sbi->s_qf_names[qtype]) {
        ext3_msg(sb, KERN_ERR, "Cannot change journaled quota options"
            " when quota turned on");
        return 0;
    }
    /*
     * The space will be released later when all options are confirmed
     * to be correct
     */
    sbi->s_qf_names[qtype] = NULL;
    return 1;
}
#endif

static int parse_options (char *options, struct super_block *sb,
              unsigned int *inum, unsigned long *journal_devnum,
              ext3_fsblk_t *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;
    kuid_t uid;
    kgid_t gid;
#ifdef CONFIG_QUOTA
    int qfmt;
#endif

    if (!options)
        return 1;

    while ((p = strsep (&options, ",")) != NULL) {
        int token;
        if (!*p)
            continue;
        /*
         * Initialize args struct so we know whether arg was
         * found; some options take optional arguments.
         */
        args[0].to = args[0].from = NULL;
        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;
            uid = make_kuid(current_user_ns(), option);
            if (!uid_valid(uid)) {
                ext3_msg(sb, KERN_ERR, "Invalid uid value %d", option);
                return 0;

            }
            sbi->s_resuid = uid;
            break;
        case Opt_resgid:
            if (match_int(&args[0], &option))
                return 0;
            gid = make_kgid(current_user_ns(), option);
            if (!gid_valid(gid)) {
                ext3_msg(sb, KERN_ERR, "Invalid gid value %d", option);
                return 0;
            }
            sbi->s_resgid = gid;
            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_nocheck:
            clear_opt (sbi->s_mount_opt, CHECK);
            break;
        case Opt_debug:
            set_opt (sbi->s_mount_opt, DEBUG);
            break;
        case Opt_oldalloc:
            ext3_msg(sb, KERN_WARNING,
                "Ignoring deprecated oldalloc option");
            break;
        case Opt_orlov:
            ext3_msg(sb, KERN_WARNING,
                "Ignoring deprecated orlov option");
            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:
            ext3_msg(sb, KERN_INFO,
                "(no)user_xattr options not supported");
            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:
            ext3_msg(sb, KERN_INFO,
                "(no)acl options not supported");
            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) {
                ext3_msg(sb, KERN_ERR, "error: cannot specify "
                    "journal on remount");
                return 0;
            }
            set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
            break;
        case Opt_journal_inum:
            if (is_remount) {
                ext3_msg(sb, KERN_ERR, "error: cannot specify "
                       "journal on remount");
                return 0;
            }
            if (match_int(&args[0], &option))
                return 0;
            *inum = option;
            break;
        case Opt_journal_dev:
            if (is_remount) {
                ext3_msg(sb, KERN_ERR, "error: cannot specify "
                       "journal on remount");
                return 0;
            }
            if (match_int(&args[0], &option))
                return 0;
            *journal_devnum = 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 (test_opt(sb, DATA_FLAGS) == data_opt)
                    break;
                ext3_msg(sb, KERN_ERR,
                    "error: cannot change "
                    "data mode on remount. The filesystem "
                    "is mounted in data=%s mode and you "
                    "try to remount it in data=%s mode.",
                    data_mode_string(test_opt(sb,
                            DATA_FLAGS)),
                    data_mode_string(data_opt));
                return 0;
            } else {
                clear_opt(sbi->s_mount_opt, DATA_FLAGS);
                sbi->s_mount_opt |= data_opt;
            }
            break;
        case Opt_data_err_abort:
            set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
            break;
        case Opt_data_err_ignore:
            clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
            break;
#ifdef CONFIG_QUOTA
        case Opt_usrjquota:
            if (!set_qf_name(sb, USRQUOTA, &args[0]))
                return 0;
            break;
        case Opt_grpjquota:
            if (!set_qf_name(sb, GRPQUOTA, &args[0]))
                return 0;
            break;
        case Opt_offusrjquota:
            if (!clear_qf_name(sb, USRQUOTA))
                return 0;
            break;
        case Opt_offgrpjquota:
            if (!clear_qf_name(sb, GRPQUOTA))
                return 0;
            break;
        case Opt_jqfmt_vfsold:
            qfmt = QFMT_VFS_OLD;
            goto set_qf_format;
        case Opt_jqfmt_vfsv0:
            qfmt = QFMT_VFS_V0;
            goto set_qf_format;
        case Opt_jqfmt_vfsv1:
            qfmt = QFMT_VFS_V1;
set_qf_format:
            if (sb_any_quota_loaded(sb) &&
                sbi->s_jquota_fmt != qfmt) {
                ext3_msg(sb, KERN_ERR, "error: cannot change "
                    "journaled quota options when "
                    "quota turned on.");
                return 0;
            }
            sbi->s_jquota_fmt = qfmt;
            break;
        case Opt_quota:
        case Opt_usrquota:
            set_opt(sbi->s_mount_opt, QUOTA);
            set_opt(sbi->s_mount_opt, USRQUOTA);
            break;
        case Opt_grpquota:
            set_opt(sbi->s_mount_opt, QUOTA);
            set_opt(sbi->s_mount_opt, GRPQUOTA);
            break;
        case Opt_noquota:
            if (sb_any_quota_loaded(sb)) {
                ext3_msg(sb, KERN_ERR, "error: cannot change "
                    "quota options when quota turned on.");
                return 0;
            }
            clear_opt(sbi->s_mount_opt, QUOTA);
            clear_opt(sbi->s_mount_opt, USRQUOTA);
            clear_opt(sbi->s_mount_opt, GRPQUOTA);
            break;
#else
        case Opt_quota:
        case Opt_usrquota:
        case Opt_grpquota:
            ext3_msg(sb, KERN_ERR,
                "error: quota options not supported.");
            break;
        case Opt_usrjquota:
        case Opt_grpjquota:
        case Opt_offusrjquota:
        case Opt_offgrpjquota:
        case Opt_jqfmt_vfsold:
        case Opt_jqfmt_vfsv0:
        case Opt_jqfmt_vfsv1:
            ext3_msg(sb, KERN_ERR,
                "error: journaled quota options not "
                "supported.");
            break;
        case Opt_noquota:
            break;
#endif
        case Opt_abort:
            set_opt(sbi->s_mount_opt, ABORT);
            break;
        case Opt_nobarrier:
            clear_opt(sbi->s_mount_opt, BARRIER);
            break;
        case Opt_barrier:
            if (args[0].from) {
                if (match_int(&args[0], &option))
                    return 0;
            } else
                option = 1; /* No argument, default to 1 */
            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 (!is_remount) {
                ext3_msg(sb, KERN_ERR,
                    "error: resize option only available "
                    "for remount");
                return 0;
            }
            if (match_int(&args[0], &option) != 0)
                return 0;
            *n_blocks_count = option;
            break;
        case Opt_nobh:
            ext3_msg(sb, KERN_WARNING,
                "warning: ignoring deprecated nobh option");
            break;
        case Opt_bh:
            ext3_msg(sb, KERN_WARNING,
                "warning: ignoring deprecated bh option");
            break;
        default:
            ext3_msg(sb, KERN_ERR,
                "error: unrecognized mount option \"%s\" "
                "or missing value", p);
            return 0;
        }
    }
#ifdef CONFIG_QUOTA
    if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
        if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
            clear_opt(sbi->s_mount_opt, USRQUOTA);
        if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
            clear_opt(sbi->s_mount_opt, GRPQUOTA);

        if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
            ext3_msg(sb, KERN_ERR, "error: old and new quota "
                    "format mixing.");
            return 0;
        }

        if (!sbi->s_jquota_fmt) {
            ext3_msg(sb, KERN_ERR, "error: journaled quota format "
                    "not specified.");
            return 0;
        }
    } else {
        if (sbi->s_jquota_fmt) {
            ext3_msg(sb, KERN_ERR, "error: journaled quota format "
                    "specified with no journaling "
                    "enabled.");
            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) {
        ext3_msg(sb, KERN_ERR,
            "error: revision level too high, "
            "forcing read-only mode");
        res = MS_RDONLY;
    }
    if (read_only)
        return res;
    if (!(sbi->s_mount_state & EXT3_VALID_FS))
        ext3_msg(sb, KERN_WARNING,
            "warning: mounting unchecked fs, "
            "running e2fsck is recommended");
    else if ((sbi->s_mount_state & EXT3_ERROR_FS))
        ext3_msg(sb, KERN_WARNING,
            "warning: mounting fs with errors, "
            "running e2fsck is recommended");
    else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
         le16_to_cpu(es->s_mnt_count) >=
            le16_to_cpu(es->s_max_mnt_count))
        ext3_msg(sb, KERN_WARNING,
            "warning: maximal mount count reached, "
            "running e2fsck is recommended");
    else if (le32_to_cpu(es->s_checkinterval) &&
        (le32_to_cpu(es->s_lastcheck) +
            le32_to_cpu(es->s_checkinterval) <= get_seconds()))
        ext3_msg(sb, KERN_WARNING,
            "warning: checktime reached, "
            "running e2fsck is recommended");
#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(~EXT3_VALID_FS);
#endif
    if (!le16_to_cpu(es->s_max_mnt_count))
        es->s_max_mnt_count = cpu_to_le16(EXT3_DFL_MAX_MNT_COUNT);
    le16_add_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))
        ext3_msg(sb, KERN_INFO, "[bs=%lu, gc=%lu, "
                "bpg=%lu, ipg=%lu, mo=%04lx]",
            sb->s_blocksize,
            sbi->s_groups_count,
            EXT3_BLOCKS_PER_GROUP(sb),
            EXT3_INODES_PER_GROUP(sb),
            sbi->s_mount_opt);

    if (EXT3_SB(sb)->s_journal->j_inode == NULL) {
        char b[BDEVNAME_SIZE];
        ext3_msg(sb, KERN_INFO, "using external journal on %s",
            bdevname(EXT3_SB(sb)->s_journal->j_dev, b));
    } else {
        ext3_msg(sb, KERN_INFO, "using internal journal");
    }
    cleancache_init_fs(sb);
    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);
    int i;

    ext3_debug ("Checking group descriptors");

    for (i = 0; i < sbi->s_groups_count; i++) {
        struct ext3_group_desc *gdp = ext3_get_group_desc(sb, i, NULL);
        ext3_fsblk_t first_block = ext3_group_first_block_no(sb, i);
        ext3_fsblk_t last_block;

        if (i == sbi->s_groups_count - 1)
            last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
        else
            last_block = first_block +
                (EXT3_BLOCKS_PER_GROUP(sb) - 1);

        if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
            le32_to_cpu(gdp->bg_block_bitmap) > last_block)
        {
            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) < first_block ||
            le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
        {
            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) < first_block ||
            le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
            last_block)
        {
            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;
        }
    }

    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 (bdev_read_only(sb->s_bdev)) {
        ext3_msg(sb, KERN_ERR, "error: write access "
            "unavailable, skipping orphan cleanup.");
        return;
    }

    /* Check if feature set allows readwrite operations */
    if (EXT3_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP)) {
        ext3_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
             "unknown ROCOMPAT features");
        return;
    }

    if (EXT3_SB(sb)->s_mount_state & EXT3_ERROR_FS) {
        /* don't clear list on RO mount w/ errors */
        if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
            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) {
        ext3_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
        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)
                ext3_msg(sb, KERN_ERR,
                    "error: cannot turn on journaled "
                    "quota: %d", ret);
        }
    }
#endif

    while (es->s_last_orphan) {
        struct inode *inode;

        inode = ext3_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
        if (IS_ERR(inode)) {
            es->s_last_orphan = 0;
            break;
        }

        list_add(&EXT3_I(inode)->i_orphan, &EXT3_SB(sb)->s_orphan);
        dquot_initialize(inode);
        if (inode->i_nlink) {
            printk(KERN_DEBUG
                "%s: truncating inode %lu to %Ld bytes\n",
                __func__, inode->i_ino, inode->i_size);
            jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
                  inode->i_ino, inode->i_size);
            ext3_truncate(inode);
            nr_truncates++;
        } else {
            printk(KERN_DEBUG
                "%s: deleting unreferenced inode %lu\n",
                __func__, inode->i_ino);
            jbd_debug(2, "deleting unreferenced inode %lu\n",
                  inode->i_ino);
            nr_orphans++;
        }
        iput(inode);  /* The delete magic happens here! */
    }

#define PLURAL(x) (x), ((x)==1) ? "" : "s"

    if (nr_orphans)
        ext3_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
               PLURAL(nr_orphans));
    if (nr_truncates)
        ext3_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
               PLURAL(nr_truncates));
#ifdef CONFIG_QUOTA
    /* Turn quotas off */
    for (i = 0; i < MAXQUOTAS; i++) {
        if (sb_dqopt(sb)->files[i])
            dquot_quota_off(sb, i);
    }
#endif
    sb->s_flags = s_flags; /* Restore MS_RDONLY status */
}

/*
 * 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;
    int meta_blocks;
    loff_t upper_limit;

    /* This is calculated to be the largest file size for a
     * dense, file such that the total number of
     * sectors in the file, including data and all indirect blocks,
     * does not exceed 2^32 -1
     * __u32 i_blocks representing the total number of
     * 512 bytes blocks of the file
     */
    upper_limit = (1LL << 32) - 1;

    /* total blocks in file system block size */
    upper_limit >>= (bits - 9);


    /* indirect blocks */
    meta_blocks = 1;
    /* double indirect blocks */
    meta_blocks += 1 + (1LL << (bits-2));
    /* tripple indirect blocks */
    meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));

    upper_limit -= meta_blocks;
    upper_limit <<= bits;

    res += 1LL << (bits-2);
    res += 1LL << (2*(bits-2));
    res += 1LL << (3*(bits-2));
    res <<= bits;
    if (res > upper_limit)
        res = upper_limit;

    if (res > MAX_LFS_FILESIZE)
        res = MAX_LFS_FILESIZE;

    return res;
}

static ext3_fsblk_t descriptor_loc(struct super_block *sb,
                    ext3_fsblk_t logic_sb_block,
                    int nr)
{
    struct ext3_sb_info *sbi = EXT3_SB(sb);
    unsigned long bg, first_meta_bg;
    int has_super = 0;

    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 (has_super + ext3_group_first_block_no(sb, bg));
}


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;
    ext3_fsblk_t block;
    ext3_fsblk_t sb_block = get_sb_block(&data, sb);
    ext3_fsblk_t logic_sb_block;
    unsigned long offset = 0;
    unsigned int journal_inum = 0;
    unsigned long journal_devnum = 0;
    unsigned long def_mount_opts;
    struct inode *root;
    int blocksize;
    int hblock;
    int db_count;
    int i;
    int needs_recovery;
    int ret = -EINVAL;
    __le32 features;
    int err;

    sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
    if (!sbi)
        return -ENOMEM;

    sbi->s_blockgroup_lock =
        kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
    if (!sbi->s_blockgroup_lock) {
        kfree(sbi);
        return -ENOMEM;
    }
    sb->s_fs_info = sbi;
    sbi->s_mount_opt = 0;
    sbi->s_resuid = make_kuid(&init_user_ns, EXT3_DEF_RESUID);
    sbi->s_resgid = make_kgid(&init_user_ns, EXT3_DEF_RESGID);
    sbi->s_sb_block = sb_block;

    blocksize = sb_min_blocksize(sb, EXT3_MIN_BLOCK_SIZE);
    if (!blocksize) {
        ext3_msg(sb, KERN_ERR, "error: unable to set blocksize");
        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))) {
        ext3_msg(sb, KERN_ERR, "error: unable to read superblock");
        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 *) (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);
#ifdef CONFIG_EXT3_FS_XATTR
    if (def_mount_opts & EXT3_DEFM_XATTR_USER)
        set_opt(sbi->s_mount_opt, XATTR_USER);
#endif
#ifdef CONFIG_EXT3_FS_POSIX_ACL
    if (def_mount_opts & EXT3_DEFM_ACL)
        set_opt(sbi->s_mount_opt, POSIX_ACL);
#endif
    if ((def_mount_opts & EXT3_DEFM_JMODE) == EXT3_DEFM_JMODE_DATA)
        set_opt(sbi->s_mount_opt, JOURNAL_DATA);
    else if ((def_mount_opts & EXT3_DEFM_JMODE) == EXT3_DEFM_JMODE_ORDERED)
        set_opt(sbi->s_mount_opt, ORDERED_DATA);
    else if ((def_mount_opts & EXT3_DEFM_JMODE) == EXT3_DEFM_JMODE_WBACK)
        set_opt(sbi->s_mount_opt, 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_CONTINUE)
        set_opt(sbi->s_mount_opt, ERRORS_CONT);
    else
        set_opt(sbi->s_mount_opt, ERRORS_RO);

    sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
    sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));

    /* enable barriers by default */
    set_opt(sbi->s_mount_opt, BARRIER);
    set_opt(sbi->s_mount_opt, RESERVATION);

    if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
                NULL, 0))
        goto failed_mount;

    sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
        (test_opt(sb, 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)))
        ext3_msg(sb, KERN_WARNING,
            "warning: feature flags set on rev 0 fs, "
            "running e2fsck is recommended");
    /*
     * 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) {
        ext3_msg(sb, KERN_ERR,
            "error: couldn't mount because of unsupported "
            "optional features (%x)", 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) {
        ext3_msg(sb, KERN_ERR,
            "error: couldn't mount RDWR because of unsupported "
            "optional features (%x)", 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) {
        ext3_msg(sb, KERN_ERR,
            "error: couldn't mount because of unsupported "
            "filesystem blocksize %d", blocksize);
        goto failed_mount;
    }

    hblock = bdev_logical_block_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) {
            ext3_msg(sb, KERN_ERR,
                "error: fsblocksize %d too small for "
                "hardware sectorsize %d", blocksize, hblock);
            goto failed_mount;
        }

        brelse (bh);
        if (!sb_set_blocksize(sb, blocksize)) {
            ext3_msg(sb, KERN_ERR,
                "error: bad blocksize %d", blocksize);
            goto out_fail;
        }
        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) {
            ext3_msg(sb, KERN_ERR,
                   "error: can't read superblock on 2nd try");
            goto failed_mount;
        }
        es = (struct ext3_super_block *)(bh->b_data + offset);
        sbi->s_es = es;
        if (es->s_magic != cpu_to_le16(EXT3_SUPER_MAGIC)) {
            ext3_msg(sb, KERN_ERR,
                "error: magic mismatch");
            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) ||
            (!is_power_of_2(sbi->s_inode_size)) ||
            (sbi->s_inode_size > blocksize)) {
            ext3_msg(sb, KERN_ERR,
                "error: unsupported inode size: %d",
                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) {
        ext3_msg(sb, KERN_ERR,
               "error: fragsize %lu != blocksize %u (unsupported)",
               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 || EXT3_INODES_PER_GROUP(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 = ilog2(EXT3_ADDR_PER_BLOCK(sb));
    sbi->s_desc_per_block_bits = ilog2(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;
    i = le32_to_cpu(es->s_flags);
    if (i & EXT2_FLAGS_UNSIGNED_HASH)
        sbi->s_hash_unsigned = 3;
    else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
#ifdef __CHAR_UNSIGNED__
        es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
        sbi->s_hash_unsigned = 3;
#else
        es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
#endif
    }

    if (sbi->s_blocks_per_group > blocksize * 8) {
        ext3_msg(sb, KERN_ERR,
            "#blocks per group too big: %lu",
            sbi->s_blocks_per_group);
        goto failed_mount;
    }
    if (sbi->s_frags_per_group > blocksize * 8) {
        ext3_msg(sb, KERN_ERR,
            "error: #fragments per group too big: %lu",
            sbi->s_frags_per_group);
        goto failed_mount;
    }
    if (sbi->s_inodes_per_group > blocksize * 8) {
        ext3_msg(sb, KERN_ERR,
            "error: #inodes per group too big: %lu",
            sbi->s_inodes_per_group);
        goto failed_mount;
    }

    err = generic_check_addressable(sb->s_blocksize_bits,
                    le32_to_cpu(es->s_blocks_count));
    if (err) {
        ext3_msg(sb, KERN_ERR,
            "error: filesystem is too large to mount safely");
        if (sizeof(sector_t) < 8)
            ext3_msg(sb, KERN_ERR,
                "error: CONFIG_LBDAF not enabled");
        ret = err;
        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) - 1)
                       / EXT3_BLOCKS_PER_GROUP(sb)) + 1;
    db_count = DIV_ROUND_UP(sbi->s_groups_count, EXT3_DESC_PER_BLOCK(sb));
    sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
                    GFP_KERNEL);
    if (sbi->s_group_desc == NULL) {
        ext3_msg(sb, KERN_ERR,
            "error: not enough memory");
        ret = -ENOMEM;
        goto failed_mount;
    }

    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]) {
            ext3_msg(sb, KERN_ERR,
                "error: can't read group descriptor %d", i);
            db_count = i;
            goto failed_mount2;
        }
    }
    if (!ext3_check_descriptors (sb)) {
        ext3_msg(sb, KERN_ERR,
            "error: group descriptors corrupted");
        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
    memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
    INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
    mutex_init(&sbi->s_orphan_lock);
    mutex_init(&sbi->s_resize_lock);

    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, journal_devnum))
            goto failed_mount2;
    } else if (journal_inum) {
        if (ext3_create_journal(sb, es, journal_inum))
            goto failed_mount2;
    } else {
        if (!silent)
            ext3_msg(sb, KERN_ERR,
                "error: no journal found. "
                "mounting ext3 over ext2?");
        goto failed_mount2;
    }
    err = percpu_counter_init(&sbi->s_freeblocks_counter,
            ext3_count_free_blocks(sb));
    if (!err) {
        err = percpu_counter_init(&sbi->s_freeinodes_counter,
                ext3_count_free_inodes(sb));
    }
    if (!err) {
        err = percpu_counter_init(&sbi->s_dirs_counter,
                ext3_count_dirs(sb));
    }
    if (err) {
        ext3_msg(sb, KERN_ERR, "error: insufficient memory");
        ret = err;
        goto failed_mount3;
    }

    /* 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, DEFAULT_DATA_MODE);
        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)) {
            ext3_msg(sb, KERN_ERR,
                "error: journal does not support "
                "requested data journaling mode");
            goto failed_mount3;
        }
    default:
        break;
    }

    /*
     * The journal_load will have done any necessary log recovery,
     * so we can safely mount the rest of the filesystem now.
     */

    root = ext3_iget(sb, EXT3_ROOT_INO);
    if (IS_ERR(root)) {
        ext3_msg(sb, KERN_ERR, "error: get root inode failed");
        ret = PTR_ERR(root);
        goto failed_mount3;
    }
    if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
        iput(root);
        ext3_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
        goto failed_mount3;
    }
    sb->s_root = d_make_root(root);
    if (!sb->s_root) {
        ext3_msg(sb, KERN_ERR, "error: get root dentry failed");
        ret = -ENOMEM;
        goto failed_mount3;
    }

    if (ext3_setup_super(sb, es, sb->s_flags & MS_RDONLY))
        sb->s_flags |= MS_RDONLY;

    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) {
        ext3_mark_recovery_complete(sb, es);
        ext3_msg(sb, KERN_INFO, "recovery complete");
    }
    ext3_msg(sb, KERN_INFO, "mounted filesystem with %s data mode",
        test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ? "journal":
        test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
        "writeback");

    return 0;

cantfind_ext3:
    if (!silent)
        ext3_msg(sb, KERN_INFO,
            "error: can't find ext3 filesystem on dev %s.",
               sb->s_id);
    goto failed_mount;

failed_mount3:
    percpu_counter_destroy(&sbi->s_freeblocks_counter);
    percpu_counter_destroy(&sbi->s_freeinodes_counter);
    percpu_counter_destroy(&sbi->s_dirs_counter);
    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->s_blockgroup_lock);
    kfree(sbi);
    return ret;
}

/*
 * 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;
    if (test_opt(sb, DATA_ERR_ABORT))
        journal->j_flags |= JFS_ABORT_ON_SYNCDATA_ERR;
    else
        journal->j_flags &= ~JFS_ABORT_ON_SYNCDATA_ERR;
    spin_unlock(&journal->j_state_lock);
}

static journal_t *ext3_get_journal(struct super_block *sb,
                   unsigned 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 = ext3_iget(sb, journal_inum);
    if (IS_ERR(journal_inode)) {
        ext3_msg(sb, KERN_ERR, "error: no journal found");
        return NULL;
    }
    if (!journal_inode->i_nlink) {
        make_bad_inode(journal_inode);
        iput(journal_inode);
        ext3_msg(sb, KERN_ERR, "error: journal inode is deleted");
        return NULL;
    }

    jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
          journal_inode, journal_inode->i_size);
    if (!S_ISREG(journal_inode->i_mode)) {
        ext3_msg(sb, KERN_ERR, "error: invalid journal inode");
        iput(journal_inode);
        return NULL;
    }

    journal = journal_init_inode(journal_inode);
    if (!journal) {
        ext3_msg(sb, KERN_ERR, "error: could not load journal inode");
        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;
    ext3_fsblk_t start;
    ext3_fsblk_t len;
    int hblock, blocksize;
    ext3_fsblk_t sb_block;
    unsigned long offset;
    struct ext3_super_block * es;
    struct block_device *bdev;

    bdev = ext3_blkdev_get(j_dev, sb);
    if (bdev == NULL)
        return NULL;

    blocksize = sb->s_blocksize;
    hblock = bdev_logical_block_size(bdev);
    if (blocksize < hblock) {
        ext3_msg(sb, KERN_ERR,
            "error: blocksize too small for journal device");
        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))) {
        ext3_msg(sb, KERN_ERR, "error: couldn't read superblock of "
            "external journal");
        goto out_bdev;
    }

    es = (struct ext3_super_block *) (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)) {
        ext3_msg(sb, KERN_ERR, "error: external journal has "
            "bad superblock");
        brelse(bh);
        goto out_bdev;
    }

    if (memcmp(EXT3_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
        ext3_msg(sb, KERN_ERR, "error: journal UUID does not match");
        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) {
        ext3_msg(sb, KERN_ERR,
            "error: failed to create device journal");
        goto out_bdev;
    }
    journal->j_private = sb;
    if (!bh_uptodate_or_lock(journal->j_sb_buffer)) {
        if (bh_submit_read(journal->j_sb_buffer)) {
            ext3_msg(sb, KERN_ERR, "I/O error on journal device");
            goto out_journal;
        }
    }
    if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
        ext3_msg(sb, KERN_ERR,
            "error: external journal has more than one "
            "user (unsupported) - %d",
            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,
                 unsigned long journal_devnum)
{
    journal_t *journal;
    unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
    dev_t journal_dev;
    int err = 0;
    int really_read_only;

    if (journal_devnum &&
        journal_devnum != le32_to_cpu(es->s_journal_dev)) {
        ext3_msg(sb, KERN_INFO, "external journal device major/minor "
            "numbers have changed");
        journal_dev = new_decode_dev(journal_devnum);
    } else
        journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));

    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) {
            ext3_msg(sb, KERN_INFO,
                "recovery required on readonly filesystem");
            if (really_read_only) {
                ext3_msg(sb, KERN_ERR, "error: write access "
                    "unavailable, cannot proceed");
                return -EROFS;
            }
            ext3_msg(sb, KERN_INFO,
                "write access will be enabled during recovery");
        }
    }

    if (journal_inum && journal_dev) {
        ext3_msg(sb, KERN_ERR, "error: filesystem has both journal "
               "and inode journals");
        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 (!(journal->j_flags & JFS_BARRIER))
        printk(KERN_INFO "EXT3-fs: barriers not enabled\n");

    if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
        err = journal_update_format(journal);
        if (err)  {
            ext3_msg(sb, KERN_ERR, "error updating journal");
            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) {
        ext3_msg(sb, KERN_ERR, "error loading journal");
        journal_destroy(journal);
        return err;
    }

    EXT3_SB(sb)->s_journal = journal;
    ext3_clear_journal_err(sb, es);

    if (!really_read_only && journal_devnum &&
        journal_devnum != le32_to_cpu(es->s_journal_dev)) {
        es->s_journal_dev = cpu_to_le32(journal_devnum);

        /* Make sure we flush the recovery flag to disk. */
        ext3_commit_super(sb, es, 1);
    }

    return 0;
}

static int ext3_create_journal(struct super_block *sb,
                   struct ext3_super_block *es,
                   unsigned int journal_inum)
{
    journal_t *journal;
    int err;

    if (sb->s_flags & MS_RDONLY) {
        ext3_msg(sb, KERN_ERR,
            "error: readonly filesystem when trying to "
            "create journal");
        return -EROFS;
    }

    journal = ext3_get_journal(sb, journal_inum);
    if (!journal)
        return -EINVAL;

    ext3_msg(sb, KERN_INFO, "creating new journal on inode %u",
           journal_inum);

    err = journal_create(journal);
    if (err) {
        ext3_msg(sb, KERN_ERR, "error creating journal");
        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);

    /* Make sure we flush the recovery flag to disk. */
    ext3_commit_super(sb, es, 1);

    return 0;
}

static int ext3_commit_super(struct super_block *sb,
                   struct ext3_super_block *es,
                   int sync)
{
    struct buffer_head *sbh = EXT3_SB(sb)->s_sbh;
    int error = 0;

    if (!sbh)
        return error;

    if (buffer_write_io_error(sbh)) {
        /*
         * Oh, dear.  A previous attempt to write the
         * superblock failed.  This could happen because the
         * USB device was yanked out.  Or it could happen to
         * be a transient write error and maybe the block will
         * be remapped.  Nothing we can do but to retry the
         * write and hope for the best.
         */
        ext3_msg(sb, KERN_ERR, "previous I/O error to "
               "superblock detected");
        clear_buffer_write_io_error(sbh);
        set_buffer_uptodate(sbh);
    }
    /*
     * If the file system is mounted read-only, don't update the
     * superblock write time.  This avoids updating the superblock
     * write time when we are mounting the root file system
     * read/only but we need to replay the journal; at that point,
     * for people who are east of GMT and who make their clock
     * tick in localtime for Windows bug-for-bug compatibility,
     * the clock is set in the future, and this will cause e2fsck
     * to complain and force a full file system check.
     */
    if (!(sb->s_flags & MS_RDONLY))
        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) {
        error = sync_dirty_buffer(sbh);
        if (buffer_write_io_error(sbh)) {
            ext3_msg(sb, KERN_ERR, "I/O error while writing "
                   "superblock");
            clear_buffer_write_io_error(sbh);
            set_buffer_uptodate(sbh);
        }
    }
    return error;
}


/*
 * 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);
    if (journal_flush(journal) < 0)
        goto out;

    if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER) &&
        sb->s_flags & MS_RDONLY) {
        EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
        ext3_commit_super(sb, es, 1);
    }

out:
    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, __func__, "Filesystem error recorded "
                 "from previous mount: %s", errstr);
        ext3_warning(sb, __func__, "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;
    ret = ext3_journal_force_commit(journal);
    return ret;
}

static int ext3_sync_fs(struct super_block *sb, int wait)
{
    tid_t target;

    trace_ext3_sync_fs(sb, wait);
    /*
     * Writeback quota in non-journalled quota case - journalled quota has
     * no dirty dquots
     */
    dquot_writeback_dquots(sb, -1);
    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 int ext3_freeze(struct super_block *sb)
{
    int error = 0;
    journal_t *journal;

    if (!(sb->s_flags & MS_RDONLY)) {
        journal = EXT3_SB(sb)->s_journal;

        /* Now we set up the journal barrier. */
        journal_lock_updates(journal);

        /*
         * We don't want to clear needs_recovery flag when we failed
         * to flush the journal.
         */
        error = journal_flush(journal);
        if (error < 0)
            goto out;

        /* Journal blocked and flushed, clear needs_recovery flag. */
        EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
        error = ext3_commit_super(sb, EXT3_SB(sb)->s_es, 1);
        if (error)
            goto out;
    }
    return 0;

out:
    journal_unlock_updates(journal);
    return error;
}

/*
 * 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 int ext3_unfreeze(struct super_block *sb)
{
    if (!(sb->s_flags & MS_RDONLY)) {
        /* 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);
        journal_unlock_updates(EXT3_SB(sb)->s_journal);
    }
    return 0;
}

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);
    ext3_fsblk_t n_blocks_count = 0;
    unsigned long old_sb_flags;
    struct ext3_mount_options old_opts;
    int enable_quota = 0;
    int err;
#ifdef CONFIG_QUOTA
    int i;
#endif

    /* Store the original options */
    old_sb_flags = sb->s_flags;
    old_opts.s_mount_opt = sbi->s_mount_opt;
    old_opts.s_resuid = sbi->s_resuid;
    old_opts.s_resgid = sbi->s_resgid;
    old_opts.s_commit_interval = sbi->s_commit_interval;
#ifdef CONFIG_QUOTA
    old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
    for (i = 0; i < MAXQUOTAS; i++)
        old_opts.s_qf_names[i] = sbi->s_qf_names[i];
#endif

    /*
     * Allow the "check" option to be passed as a remount option.
     */
    if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
        err = -EINVAL;
        goto restore_opts;
    }

    if (test_opt(sb, ABORT))
        ext3_abort(sb, __func__, "Abort forced by user");

    sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
        (test_opt(sb, 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 (test_opt(sb, ABORT)) {
            err = -EROFS;
            goto restore_opts;
        }

        if (*flags & MS_RDONLY) {
            err = dquot_suspend(sb, -1);
            if (err < 0)
                goto restore_opts;

            /*
             * 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))) {
                ext3_msg(sb, KERN_WARNING,
                    "warning: couldn't remount RDWR "
                    "because of unsupported optional "
                    "features (%x)", le32_to_cpu(ret));
                err = -EROFS;
                goto restore_opts;
            }

            /*
             * If we have an unprocessed orphan list hanging
             * around from a previously readonly bdev mount,
             * require a full umount & mount for now.
             */
            if (es->s_last_orphan) {
                ext3_msg(sb, KERN_WARNING, "warning: couldn't "
                       "remount RDWR because of unprocessed "
                       "orphan inode list.  Please "
                       "umount & mount instead.");
                err = -EINVAL;
                goto restore_opts;
            }

            /*
             * 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 ((err = ext3_group_extend(sb, es, n_blocks_count)))
                goto restore_opts;
            if (!ext3_setup_super (sb, es, 0))
                sb->s_flags &= ~MS_RDONLY;
            enable_quota = 1;
        }
    }
#ifdef CONFIG_QUOTA
    /* Release old quota file names */
    for (i = 0; i < MAXQUOTAS; i++)
        if (old_opts.s_qf_names[i] &&
            old_opts.s_qf_names[i] != sbi->s_qf_names[i])
            kfree(old_opts.s_qf_names[i]);
#endif
    if (enable_quota)
        dquot_resume(sb, -1);
    return 0;
restore_opts:
    sb->s_flags = old_sb_flags;
    sbi->s_mount_opt = old_opts.s_mount_opt;
    sbi->s_resuid = old_opts.s_resuid;
    sbi->s_resgid = old_opts.s_resgid;
    sbi->s_commit_interval = old_opts.s_commit_interval;
#ifdef CONFIG_QUOTA
    sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
    for (i = 0; i < MAXQUOTAS; i++) {
        if (sbi->s_qf_names[i] &&
            old_opts.s_qf_names[i] != sbi->s_qf_names[i])
            kfree(sbi->s_qf_names[i]);
        sbi->s_qf_names[i] = old_opts.s_qf_names[i];
    }
#endif
    return err;
}

static int ext3_statfs (struct dentry * dentry, struct kstatfs * buf)
{
    struct super_block *sb = dentry->d_sb;
    struct ext3_sb_info *sbi = EXT3_SB(sb);
    struct ext3_super_block *es = sbi->s_es;
    u64 fsid;

    if (test_opt(sb, MINIX_DF)) {
        sbi->s_overhead_last = 0;
    } else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
        unsigned long ngroups = sbi->s_groups_count, i;
        ext3_fsblk_t overhead = 0;
        smp_rmb();

        /*
         * Compute the overhead (FS structures).  This is constant
         * for a given filesystem unless the number of block groups
         * changes so we cache the previous value until it does.
         */

        /*
         * 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 + sbi->s_itb_per_group);
        sbi->s_overhead_last = overhead;
        smp_wmb();
        sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
    }

    buf->f_type = EXT3_SUPER_MAGIC;
    buf->f_bsize = sb->s_blocksize;
    buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
    buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
    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 = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
    buf->f_namelen = EXT3_NAME_LEN;
    fsid = le64_to_cpup((void *)es->s_uuid) ^
           le64_to_cpup((void *)es->s_uuid + sizeof(u64));
    buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
    buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
    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_initialize()                       down(dqio_mutex)
 *     down(dqio_mutex)                    journal_start()
 *
 */

#ifdef CONFIG_QUOTA

static inline struct inode *dquot_to_inode(struct dquot *dquot)
{
    return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
}

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(dquot->dq_sb));
    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(dquot->dq_sb));
    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_DEL_BLOCKS(dquot->dq_sb));
    if (IS_ERR(handle)) {
        /* Release dquot anyway to avoid endless cycle in dqput() */
        dquot_release(dquot);
        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 journaling 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)
{
    return dquot_quota_on_mount(sb, EXT3_SB(sb)->s_qf_names[type],
                    EXT3_SB(sb)->s_jquota_fmt, type);
}

/*
 * Standard function to be called on quota_on
 */
static int ext3_quota_on(struct super_block *sb, int type, int format_id,
             struct path *path)
{
    int err;

    if (!test_opt(sb, QUOTA))
        return -EINVAL;

    /* Quotafile not on the same filesystem? */
    if (path->dentry->d_sb != sb)
        return -EXDEV;
    /* Journaling quota? */
    if (EXT3_SB(sb)->s_qf_names[type]) {
        /* Quotafile not of fs root? */
        if (path->dentry->d_parent != sb->s_root)
            ext3_msg(sb, KERN_WARNING,
                "warning: Quota file not on filesystem root. "
                "Journaled quota will not work.");
    }

    /*
     * When we journal data on quota file, we have to flush journal to see
     * all updates to the file when we bypass pagecache...
     */
    if (ext3_should_journal_data(path->dentry->d_inode)) {
        /*
         * We don't need to lock updates but journal_flush() could
         * otherwise be livelocked...
         */
        journal_lock_updates(EXT3_SB(sb)->s_journal);
        err = journal_flush(EXT3_SB(sb)->s_journal);
        journal_unlock_updates(EXT3_SB(sb)->s_journal);
        if (err)
            return err;
    }

    return dquot_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 no one 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 journal_quota = EXT3_SB(sb)->s_qf_names[type] != NULL;
    struct buffer_head *bh;
    handle_t *handle = journal_current_handle();

    if (!handle) {
        ext3_msg(sb, KERN_WARNING,
            "warning: quota write (off=%llu, len=%llu)"
            " cancelled because transaction is not started.",
            (unsigned long long)off, (unsigned long long)len);
        return -EIO;
    }

    /*
     * Since we account only one data block in transaction credits,
     * then it is impossible to cross a block boundary.
     */
    if (sb->s_blocksize - offset < len) {
        ext3_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
            " cancelled because not block aligned",
            (unsigned long long)off, (unsigned long long)len);
        return -EIO;
    }
    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, len);
    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);
out:
    if (err)
        return err;
    if (inode->i_size < off + len) {
        i_size_write(inode, off + len);
        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);
    return len;
}

#endif

static struct dentry *ext3_mount(struct file_system_type *fs_type,
    int flags, const char *dev_name, void *data)
{
    return mount_bdev(fs_type, flags, dev_name, data, ext3_fill_super);
}

static struct file_system_type ext3_fs_type = {
    .owner      = THIS_MODULE,
    .name       = "ext3",
    .mount      = ext3_mount,
    .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)