Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull ext2, ext3 and quota fixes from Jan Kara:
 "Interesting bits are:
   - removal of a special i_mutex locking subclass (I_MUTEX_QUOTA) since
     quota code does not need i_mutex anymore in any unusual way.
   - backport (from ext4) of a fix of a checkpointing bug (missing cache
     flush) that could lead to fs corruption on power failure

  The rest are just random small fixes & cleanups."

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext2: trivial fix to comment for ext2_free_blocks
  ext2: remove the redundant comment for ext2_export_ops
  ext3: return 32/64-bit dir name hash according to usage type
  quota: Get rid of nested I_MUTEX_QUOTA locking subclass
  quota: Use precomputed value of sb_dqopt in dquot_quota_sync
  ext2: Remove i_mutex use from ext2_quota_write()
  reiserfs: Remove i_mutex use from reiserfs_quota_write()
  ext4: Remove i_mutex use from ext4_quota_write()
  ext3: Remove i_mutex use from ext3_quota_write()
  quota: Fix double lock in add_dquot_ref() with CONFIG_QUOTA_DEBUG
  jbd: Write journal superblock with WRITE_FUA after checkpointing
  jbd: protect all log tail updates with j_checkpoint_mutex
  jbd: Split updating of journal superblock and marking journal empty
  ext2: do not register write_super within VFS
  ext2: Remove s_dirt handling
  ext2: write superblock only once on unmount
  ext3: update documentation with barrier=1 default
  ext3: remove max_debt in find_group_orlov()
  jbd: Refine commit writeout logic

fs/ext2/super.c

@@ -130,9 +130,6 @@ static void ext2_put_super (struct super_block * sb)
 
 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 
-	if (sb->s_dirt)
-		ext2_write_super(sb);
-
 	ext2_xattr_put_super(sb);
 	if (!(sb->s_flags & MS_RDONLY)) {
 		struct ext2_super_block *es = sbi->s_es;
@@ -307,7 +304,6 @@ static const struct super_operations ext2_sops = {
 	.write_inode	= ext2_write_inode,
 	.evict_inode	= ext2_evict_inode,
 	.put_super	= ext2_put_super,
-	.write_super	= ext2_write_super,
 	.sync_fs	= ext2_sync_fs,
 	.statfs		= ext2_statfs,
 	.remount_fs	= ext2_remount,
@@ -358,11 +354,6 @@ static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 				    ext2_nfs_get_inode);
 }
 
-/* Yes, most of these are left as NULL!!
- * A NULL value implies the default, which works with ext2-like file
- * systems, but can be improved upon.
- * Currently only get_parent is required.
- */
 static const struct export_operations ext2_export_ops = {
 	.fh_to_dentry = ext2_fh_to_dentry,
 	.fh_to_parent = ext2_fh_to_parent,
@@ -1176,7 +1167,6 @@ static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
 	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
 	if (wait)
 		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
-	sb->s_dirt = 0;
 }
 
 /*
@@ -1209,8 +1199,6 @@ void ext2_write_super(struct super_block *sb)
 {
 	if (!(sb->s_flags & MS_RDONLY))
 		ext2_sync_fs(sb, 1);
-	else
-		sb->s_dirt = 0;
 }
 
 static int ext2_remount (struct super_block * sb, int * flags, char * data)
@@ -1456,7 +1444,6 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type,
 	struct buffer_head tmp_bh;
 	struct buffer_head *bh;
 
-	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
 	while (towrite > 0) {
 		tocopy = sb->s_blocksize - offset < towrite ?
 				sb->s_blocksize - offset : towrite;
@@ -1486,16 +1473,13 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type,
 		blk++;
 	}
 out:
-	if (len == towrite) {
-		mutex_unlock(&inode->i_mutex);
+	if (len == towrite)
 		return err;
-	}
 	if (inode->i_size < off+len-towrite)
 		i_size_write(inode, off+len-towrite);
 	inode->i_version++;
 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 	mark_inode_dirty(inode);
-	mutex_unlock(&inode->i_mutex);
 	return len - towrite;
 }