On Fri, Dec 23, 2011 at 01:44:53PM +0300, Dan Carpenter wrote: > Hi Josef, > > Smatch complains about this change introduces a double unlock. > > fs/btrfs/async-thread.c +608 find_worker(49) error: double unlock 'spin_lock:&workers->lock' > > 579 spin_unlock_irqrestore(&workers->lock, flags); > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Thanks Dan, fixing. > We unlock here. > > 580 /* we're below the limit, start another worker */ > 581 ret = __btrfs_start_workers(workers); > 582 if (ret) > 583 goto fallback; > 584 goto again; > 585 } > 586 } > 587 goto found; > 588 > 589 fallback: > 590 fallback = NULL; > 591 /* > 592 * we have failed to find any workers, just > 593 * return the first one we can find. > 594 */ > 595 if (!list_empty(&workers->worker_list)) > 596 fallback = workers->worker_list.next; > 597 if (!list_empty(&workers->idle_list)) > 598 fallback = workers->idle_list.next; > 599 BUG_ON(!fallback); > 600 worker = list_entry(fallback, > 601 struct btrfs_worker_thread, worker_list); > 602 found: > 603 /* > 604 * this makes sure the worker doesn't exit before it is placed > 605 * onto a busy/idle list > 606 */ > 607 atomic_inc(&worker->num_pending); > 608 spin_unlock_irqrestore(&workers->lock, flags); > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > And again here. > > Btw, does find_worker() ever get called with IRQs disabled? If so then > __btrfs_start_workers() enables them. Maybe that function should use > spin_lock_irqsave() instead of spin_lock_irq(). Patching this too. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
