[PATCH 2/2] writeback: use DEFINE_WAIT_BIT instead of DEFINE_WAIT for bit wait queue

[Jacob Wen <jian.w.wen@xxxxxxxxxx>]

DEFINE_WAIT_BIT uses wake_bit_function() which is able to avoid
false-wakeups due to possible hash collisions in the bit wait table.

Signed-off-by: Jacob Wen <jian.w.wen@xxxxxxxxxx>
---
 fs/fs-writeback.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index a605c3dddabc..3bf751b33b48 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1354,16 +1354,16 @@ void inode_wait_for_writeback(struct inode *inode)
 static void inode_sleep_on_writeback(struct inode *inode)
 	__releases(inode->i_lock)
 {
-	DEFINE_WAIT(wait);
+	DEFINE_WAIT_BIT(wait, &inode->i_state, __I_SYNC);
 	wait_queue_head_t *wqh = bit_waitqueue(&inode->i_state, __I_SYNC);
 	int sleep;
 
-	prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
+	prepare_to_wait(wqh, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
 	sleep = inode->i_state & I_SYNC;
 	spin_unlock(&inode->i_lock);
 	if (sleep)
 		schedule();
-	finish_wait(wqh, &wait);
+	finish_wait(wqh, &wait.wq_entry);
 }
 
 /*
-- 
2.17.1