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>

1 files 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);