ext3: ext3_mark_recovery_complete() doesn't need to use lock_super

The function ext3_mark_recovery_complete() is called from two call
paths: either (a) while mounting the filesystem, in which case there's
no danger of any other CPU calling write_super() until the mount is
completed, and (b) while remounting the filesystem read-write, in
which case the fs core has already locked the superblock.  This also
allows us to take out a very vile unlock_super()/lock_super() pair in
ext3_remount().

Port of ext4 commit a63c9eb2ce6f5028da90f282798232c4f398ceb8 by
Theodore Ts'o <tytso@mit.edu>.

CC: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 8ad566b845ae3af341c485924c15cf46fade8b4f..806b8b780adde9aede6fbd75e0ae98cc41ea5743 100644 (file)
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -2396,13 +2396,11 @@ static void ext3_mark_recovery_complete(struct super_block * sb,
        if (journal_flush(journal) < 0)
                goto out;
 
-       lock_super(sb);
        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);
        }
-       unlock_super(sb);
 
 out:
        journal_unlock_updates(journal);
@@ -2594,13 +2592,7 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
                            (sbi->s_mount_state & EXT3_VALID_FS))
                                es->s_state = cpu_to_le16(sbi->s_mount_state);
 
-                       /*
-                        * We have to unlock super so that we can wait for
-                        * transactions.
-                        */
-                       unlock_super(sb);
                        ext3_mark_recovery_complete(sb, es);
-                       lock_super(sb);
                } else {
                        __le32 ret;
                        if ((ret = EXT3_HAS_RO_COMPAT_FEATURE(sb,