->write_super lock_super pushdown

Push down lock_super into ->write_super instances and remove it from the
caller.

Following filesystem don't need ->s_lock in ->write_super and are skipped:

 * bfs, nilfs2 - no other uses of s_lock and have internal locks in
	->write_super
 * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
 * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
 	->write_super
 * xfs - no other uses of s_lock and uses internal lock (buffer lock on
	superblock buffer) to serialize ->write_super.  Also xfs_fs_write_super
	is superflous and will go away in the next merge window

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 2b88c93af227..2292cbf7d364 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -441,10 +441,12 @@ static void fat_clear_inode(struct inode *inode)
 
 static void fat_write_super(struct super_block *sb)
 {
+        lock_super(sb);
         sb->s_dirt = 0;
 
         if (!(sb->s_flags & MS_RDONLY))
                 fat_clusters_flush(sb);
+        unlock_super(sb);
 }
 
 static void fat_put_super(struct super_block *sb)