fs: buffer lock use lock bitops

trylock_buffer and unlock_buffer open and close a critical section. Hence, we can use the lock bitops to get the desired memory ordering. Signed-off-by: Nick Piggin <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
RyanHsu · Oct 20, 2008 · 51b07fc · 51b07fc
1 parent 8413ac9
commit 51b07fc
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diff --git a/fs/buffer.c b/fs/buffer.c
@@ -76,8 +76,7 @@ EXPORT_SYMBOL(__lock_buffer);
 
 void unlock_buffer(struct buffer_head *bh)
 {
-	smp_mb__before_clear_bit();
-	clear_buffer_locked(bh);
+	clear_bit_unlock(BH_Lock, &bh->b_state);
 	smp_mb__after_clear_bit();
 	wake_up_bit(&bh->b_state, BH_Lock);
 }

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
@@ -322,7 +322,7 @@ static inline void wait_on_buffer(struct buffer_head *bh)
 
 static inline int trylock_buffer(struct buffer_head *bh)
 {
-	return likely(!test_and_set_bit(BH_Lock, &bh->b_state));
+	return likely(!test_and_set_bit_lock(BH_Lock, &bh->b_state));
 }
 
 static inline void lock_buffer(struct buffer_head *bh)