filesystem freeze: add error handling of write_super_lockfs/unlockfs
[linux-2.6.git] / fs / ext4 / super.c
index 8f7e0be..e5f06a5 100644 (file)
@@ -51,7 +51,7 @@ struct proc_dir_entry *ext4_proc_root;
 
 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
                             unsigned long journal_devnum);
-static void ext4_commit_super(struct super_block *sb,
+static int ext4_commit_super(struct super_block *sb,
                              struct ext4_super_block *es, int sync);
 static void ext4_mark_recovery_complete(struct super_block *sb,
                                        struct ext4_super_block *es);
@@ -62,9 +62,9 @@ static const char *ext4_decode_error(struct super_block *sb, int errno,
                                     char nbuf[16]);
 static int ext4_remount(struct super_block *sb, int *flags, char *data);
 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
-static void ext4_unlockfs(struct super_block *sb);
+static int ext4_unfreeze(struct super_block *sb);
 static void ext4_write_super(struct super_block *sb);
-static void ext4_write_super_lockfs(struct super_block *sb);
+static int ext4_freeze(struct super_block *sb);
 
 
 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
@@ -978,8 +978,8 @@ static const struct super_operations ext4_sops = {
        .put_super      = ext4_put_super,
        .write_super    = ext4_write_super,
        .sync_fs        = ext4_sync_fs,
-       .write_super_lockfs = ext4_write_super_lockfs,
-       .unlockfs       = ext4_unlockfs,
+       .freeze_fs      = ext4_freeze,
+       .unfreeze_fs    = ext4_unfreeze,
        .statfs         = ext4_statfs,
        .remount_fs     = ext4_remount,
        .clear_inode    = ext4_clear_inode,
@@ -2888,13 +2888,14 @@ static int ext4_load_journal(struct super_block *sb,
        return 0;
 }
 
-static void ext4_commit_super(struct super_block *sb,
+static int ext4_commit_super(struct super_block *sb,
                              struct ext4_super_block *es, int sync)
 {
        struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
+       int error = 0;
 
        if (!sbh)
-               return;
+               return error;
        if (buffer_write_io_error(sbh)) {
                /*
                 * Oh, dear.  A previous attempt to write the
@@ -2918,14 +2919,19 @@ static void ext4_commit_super(struct super_block *sb,
        BUFFER_TRACE(sbh, "marking dirty");
        mark_buffer_dirty(sbh);
        if (sync) {
-               sync_dirty_buffer(sbh);
-               if (buffer_write_io_error(sbh)) {
+               error = sync_dirty_buffer(sbh);
+               if (error)
+                       return error;
+
+               error = buffer_write_io_error(sbh);
+               if (error) {
                        printk(KERN_ERR "EXT4-fs: I/O error while writing "
                               "superblock for %s.\n", sb->s_id);
                        clear_buffer_write_io_error(sbh);
                        set_buffer_uptodate(sbh);
                }
        }
+       return error;
 }
 
 
@@ -3058,12 +3064,14 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
  * LVM calls this function before a (read-only) snapshot is created.  This
  * gives us a chance to flush the journal completely and mark the fs clean.
  */
-static void ext4_write_super_lockfs(struct super_block *sb)
+static int ext4_freeze(struct super_block *sb)
 {
+       int error = 0;
+       journal_t *journal;
        sb->s_dirt = 0;
 
        if (!(sb->s_flags & MS_RDONLY)) {
-               journal_t *journal = EXT4_SB(sb)->s_journal;
+               journal = EXT4_SB(sb)->s_journal;
 
                if (journal) {
                        /* Now we set up the journal barrier. */
@@ -3073,21 +3081,29 @@ static void ext4_write_super_lockfs(struct super_block *sb)
                         * We don't want to clear needs_recovery flag when we
                         * failed to flush the journal.
                         */
-                       if (jbd2_journal_flush(journal) < 0)
-                               return;
+                       error = jbd2_journal_flush(journal);
+                       if (error < 0)
+                               goto out;
                }
 
                /* Journal blocked and flushed, clear needs_recovery flag. */
                EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
                ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
+               error = ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
+               if (error)
+                       goto out;
        }
+       return 0;
+out:
+       jbd2_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 void ext4_unlockfs(struct super_block *sb)
+static int ext4_unfreeze(struct super_block *sb)
 {
        if (EXT4_SB(sb)->s_journal && !(sb->s_flags & MS_RDONLY)) {
                lock_super(sb);
@@ -3097,6 +3113,7 @@ static void ext4_unlockfs(struct super_block *sb)
                unlock_super(sb);
                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
        }
+       return 0;
 }
 
 static int ext4_remount(struct super_block *sb, int *flags, char *data)