From deed62edffe600bc5b379c872d3004116e001b66 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@suse.de>
Date: Tue, 15 Sep 2009 21:32:58 +0200
Subject: [PATCH] writeback: remove smp_mb(), it's not needed with
 list_add_tail_rcu()

list_add_tail_rcu contains required barriers.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
 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 34757758511a..59c99e729187 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -151,10 +151,10 @@ static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work)
 	BUG_ON(!bdi->wb_cnt);
 
 	/*
-	 * Make sure stores are seen before it appears on the list
+	 * list_add_tail_rcu() contains the necessary barriers to
+	 * make sure the above stores are seen before the item is
+	 * noticed on the list
 	 */
-	smp_mb();
-
 	spin_lock(&bdi->wb_lock);
 	list_add_tail_rcu(&work->list, &bdi->work_list);
 	spin_unlock(&bdi->wb_lock);
-- 
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