From: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx Reported-by: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx> Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Omar Sandoval <osandov@xxxxxx> Cc: Ming Lei <ming.lei@xxxxxxxxxx> Cc: linux-block@xxxxxxxxxxxxxxx Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- lib/sbitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -435,7 +435,7 @@ static void sbitmap_queue_update_wake_ba * 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); }