From patchwork Wed Sep 30 08:02:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 11808367 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6A35F112C for ; Wed, 30 Sep 2020 08:03:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 553882076E for ; Wed, 30 Sep 2020 08:03:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728453AbgI3IDC (ORCPT ); Wed, 30 Sep 2020 04:03:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:60954 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbgI3IDC (ORCPT ); Wed, 30 Sep 2020 04:03:02 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6AB27AB0E; Wed, 30 Sep 2020 08:03:01 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: Christoph Hellwig , James Bottomley , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCH 0/4] scsi: remove devices in ALUA transitioning status Date: Wed, 30 Sep 2020 10:02:52 +0200 Message-Id: <20200930080256.90964-1-hare@suse.de> X-Mailer: git-send-email 2.16.4 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi all, during testing we found that there is an issue with dev_loss_tmo and devices in ALUA transitioning state. What happens is that I/O gets requeued via BLK_STS_RESOURCE for these devices, so when dev_loss_tmo triggers the SCSI core cannot flush the request list as I/O is simply requeued. So when the driver is trying to re-establish the device it'll wait for that last reference to drop in order to re-attach the device, but as I/O is still outstanding on the (old) device it'll wait for ever. Fix this by returning 'BLK_STS_AGAIN' from scsi_dh_alua when the device is in ALUA transitioning, and also set the 'transitioning' state when scsi_dh_alua is receiving a sense code, and not only after scsi_dh_alua successfully received the response to a REPORT TARGET PORT GROUPS command. Hannes Reinecke (4): block: return status code in blk_mq_end_request() scsi_dh_alua: return BLK_STS_AGAIN for ALUA transitioning state scsi_dh_alua: set 'transitioning' state on unit attention scsi: return BLK_STS_AGAIN for ALUA transitioning block/blk-mq.c | 2 +- drivers/scsi/device_handler/scsi_dh_alua.c | 10 +++++++++- drivers/scsi/scsi_lib.c | 8 ++++++++ 3 files changed, 18 insertions(+), 2 deletions(-) Reviewed-by: Ewan D. Milne