From: Andrea Parri andrea.parri@amarulasolutions.com
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" paulmck@linux.ibm.com Reported-by: Peter Zijlstra peterz@infradead.org Signed-off-by: Andrea Parri andrea.parri@amarulasolutions.com Reviewed-by: Ming Lei ming.lei@redhat.com Cc: Jens Axboe axboe@kernel.dk Cc: Omar Sandoval osandov@fb.com Cc: Ming Lei ming.lei@redhat.com Cc: linux-block@vger.kernel.org Cc: "Paul E. McKenney" paulmck@linux.ibm.com Cc: Peter Zijlstra peterz@infradead.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- lib/sbitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -338,7 +338,7 @@ void sbitmap_queue_resize(struct sbitmap * 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); }