[PATCH] use smp_mb/wmb/rmb where possible

Replace a number of memory barriers with smp_ variants.  This means we won't
take the unnecessary hit on UP machines.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 665db84a1f9f..188365c79204 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -218,7 +218,7 @@ struct super_block *freeze_bdev(struct block_device *bdev)
         sb = get_super(bdev);
         if (sb && !(sb->s_flags & MS_RDONLY)) {
                 sb->s_frozen = SB_FREEZE_WRITE;
-                wmb();
+                smp_wmb();
 
                 sync_inodes_sb(sb, 0);
                 DQUOT_SYNC(sb);
@@ -235,7 +235,7 @@ struct super_block *freeze_bdev(struct block_device *bdev)
                 sync_inodes_sb(sb, 1);
 
                 sb->s_frozen = SB_FREEZE_TRANS;
-                wmb();
+                smp_wmb();
 
                 sync_blockdev(sb->s_bdev);
 
@@ -263,7 +263,7 @@ void thaw_bdev(struct block_device *bdev, struct super_block *sb)
                 if (sb->s_op->unlockfs)
                         sb->s_op->unlockfs(sb);
                 sb->s_frozen = SB_UNFROZEN;
-                wmb();
+                smp_wmb();
                 wake_up(&sb->s_wait_unfrozen);
                 drop_super(sb);
         }