From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zimbra13.linbit.com (zimbra.linbit.com [212.69.161.123]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTPS id D108F1055F55 for ; Tue, 4 Aug 2015 14:56:59 +0200 (CEST) From: Philipp Reisner To: linux-kernel@vger.kernel.org, Jens Axboe Date: Tue, 4 Aug 2015 14:56:36 +0200 Message-Id: <1438693003-17554-13-git-send-email-philipp.reisner@linbit.com> In-Reply-To: <1438693003-17554-1-git-send-email-philipp.reisner@linbit.com> References: <1438693003-17554-1-git-send-email-philipp.reisner@linbit.com> Cc: drbd-dev@lists.linbit.com Subject: [Drbd-dev] [PATCH 12/19] drbd: don't block forever in disconnect during resync if fencing=r-a-stonith List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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