From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933283AbbHDM7J (ORCPT ); Tue, 4 Aug 2015 08:59:09 -0400 Received: from zimbra13.linbit.com ([212.69.166.240]:48491 "EHLO zimbra13.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756305AbbHDM5H (ORCPT ); Tue, 4 Aug 2015 08:57:07 -0400 From: Philipp Reisner To: linux-kernel@vger.kernel.org, Jens Axboe Cc: drbd-dev@lists.linbit.com Subject: [PATCH 12/19] drbd: don't block forever in disconnect during resync if fencing=r-a-stonith Date: Tue, 4 Aug 2015 14:56:36 +0200 Message-Id: <1438693003-17554-13-git-send-email-philipp.reisner@linbit.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1438693003-17554-1-git-send-email-philipp.reisner@linbit.com> References: <1438693003-17554-1-git-send-email-philipp.reisner@linbit.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lars Ellenberg Disconnect should wait for pending bitmap IO. But if that bitmap IO is not happening, because it is waiting for pending application IO, and there is no progress, because the fencing policy suspended application IO because of the disconnect, then we deadlock. The bitmap writeout in this case does not care for concurrent application IO, so there is no point waiting for it. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index fea97fe..d26ddb6 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -3564,7 +3564,9 @@ void drbd_queue_bitmap_io(struct drbd_device *device, spin_lock_irq(&device->resource->req_lock); set_bit(BITMAP_IO, &device->flags); - if (atomic_read(&device->ap_bio_cnt) == 0) { + /* don't wait for pending application IO if the caller indicates that + * application IO does not conflict anyways. */ + if (flags == BM_LOCKED_CHANGE_ALLOWED || atomic_read(&device->ap_bio_cnt) == 0) { if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags)) drbd_queue_work(&first_peer_device(device)->connection->sender_work, &device->bm_io_work.w); -- 1.9.1