From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755019AbdJINZm (ORCPT ); Mon, 9 Oct 2017 09:25:42 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43462 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755273AbdJINUz (ORCPT ); Mon, 9 Oct 2017 09:20:55 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Hannes Reinecke" , "Martin K. Petersen" , "Douglas Miller" , linux-scsi@vger.kernel.org, "James E.J. Bottomley" , "Paolo Bonzini" Date: Mon, 09 Oct 2017 13:44:24 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 051/192] scsi: virtio_scsi: let host do exception handling In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini commit e72c9a2a67a6400c8ef3d01d4c461dbbbfa0e1f0 upstream. virtio_scsi tries to do exception handling after the default 30 seconds timeout expires. However, it's better to let the host control the timeout, otherwise with a heavy I/O load it is likely that an abort will also timeout. This leads to fatal errors like filesystems going offline. Disable the 'sd' timeout and allow the host to do exception handling, following the precedent of the storvsc driver. Hannes has a proposal to introduce timeouts in virtio, but this provides an immediate solution for stable kernels too. [mkp: fixed typo] Reported-by: Douglas Miller Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Hannes Reinecke Cc: linux-scsi@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Martin K. Petersen [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/scsi/virtio_scsi.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -686,6 +686,16 @@ static void virtscsi_target_destroy(stru kfree(tgt); } +/* + * The host guarantees to respond to each command, although I/O + * latencies might be higher than on bare metal. Reset the timer + * unconditionally to give the host a chance to perform EH. + */ +static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) +{ + return BLK_EH_RESET_TIMER; +} + static struct scsi_host_template virtscsi_host_template_single = { .module = THIS_MODULE, .name = "Virtio SCSI HBA", @@ -695,6 +705,7 @@ static struct scsi_host_template virtscs .queuecommand = virtscsi_queuecommand_single, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, + .eh_timed_out = virtscsi_eh_timed_out, .can_queue = 1024, .dma_boundary = UINT_MAX, @@ -712,6 +723,7 @@ static struct scsi_host_template virtscs .queuecommand = virtscsi_queuecommand_multi, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, + .eh_timed_out = virtscsi_eh_timed_out, .can_queue = 1024, .dma_boundary = UINT_MAX,