From fce095450bf7ecab866b2311e310463796ca746b Mon Sep 17 00:00:00 2001 From: Andrea Parri Date: Mon, 20 May 2019 19:23:57 +0200 Subject: [PATCH] sbitmap: fix improper use of smp_mb__before_atomic() commit a0934fd2b1208458e55fc4b48f55889809fce666 upstream. This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic_set() primitive. Replace the barrier with an smp_mb(). Fixes: 6c0ca7ae292ad ("sbitmap: fix wakeup hang after sbq resize") Cc: stable@vger.kernel.org Reported-by: "Paul E. McKenney" Reported-by: Peter Zijlstra Signed-off-by: Andrea Parri Reviewed-by: Ming Lei Cc: Jens Axboe Cc: Omar Sandoval Cc: Ming Lei Cc: linux-block@vger.kernel.org Cc: "Paul E. McKenney" Cc: Peter Zijlstra Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- lib/sbitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 80aa8d5463fa..8e467917e0d1 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -338,7 +338,7 @@ void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) * Pairs with the memory barrier in sbq_wake_up() to ensure that * the batch size is updated before the wait counts. */ - smp_mb__before_atomic(); + smp_mb(); for (i = 0; i < SBQ_WAIT_QUEUES; i++) atomic_set(&sbq->ws[i].wait_cnt, 1); }