From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 867A0C433DB for ; Fri, 29 Jan 2021 15:52:04 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CCD4364D9A for ; Fri, 29 Jan 2021 15:52:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CCD4364D9A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4DS2016ZgPzDsXk for ; Sat, 30 Jan 2021 02:52:01 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=sashal@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=dV39hhwH; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4DS1j660BbzDrj8 for ; Sat, 30 Jan 2021 02:39:06 +1100 (AEDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id 6C5E364E12; Fri, 29 Jan 2021 15:39:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611934744; bh=Nogwv7lW236FlG9laAEQyERHcHhF0IvFYA0aUlAnmuo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dV39hhwH9ZtNd92CZ3mJIze9KJOuLoPfUZPCnzZcI3XvxKg98B/4tEy9Pfhbq1KvX waJLV+4HJneztPbrIPAXWnNEPKefnjTQElxQg+7N9MQ+30n2GsxumHkMU/Hc86UcbX 7aK0YahwPlvdXl69GotRg6zoxN/YL9bRyYIk4w0omfNNs5U8MzuXFBnhz5cGcr3mFC Hae5Ym2ktSPEDU3Ru2ig+jteXLEX2nD1sJsSWZ/T28/RQ6uhB8NBAXjn55WnGGHciN a7IfaiUdg2mWbPIhrTFUwtQbkOS1kHSb8iB32H8nqhCYurGj+MbTGX6WumWw87s35e XYEd5oSAL6RWw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 3/4] scsi: ibmvfc: Set default timeout to avoid crash during migration Date: Fri, 29 Jan 2021 10:38:58 -0500 Message-Id: <20210129153859.1593031-3-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210129153859.1593031-1-sashal@kernel.org> References: <20210129153859.1593031-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Brian King , Sasha Levin , linuxppc-dev@lists.ozlabs.org, linux-scsi@vger.kernel.org, "Martin K . Petersen" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Brian King [ Upstream commit 764907293edc1af7ac857389af9dc858944f53dc ] While testing live partition mobility, we have observed occasional crashes of the Linux partition. What we've seen is that during the live migration, for specific configurations with large amounts of memory, slow network links, and workloads that are changing memory a lot, the partition can end up being suspended for 30 seconds or longer. This resulted in the following scenario: CPU 0 CPU 1 ------------------------------- ---------------------------------- scsi_queue_rq migration_store -> blk_mq_start_request -> rtas_ibm_suspend_me -> blk_add_timer -> on_each_cpu(rtas_percpu_suspend_me _______________________________________V | V -> IPI from CPU 1 -> rtas_percpu_suspend_me -> __rtas_suspend_last_cpu -- Linux partition suspended for > 30 seconds -- -> for_each_online_cpu(cpu) plpar_hcall_norets(H_PROD -> scsi_dispatch_cmd -> scsi_times_out -> scsi_abort_command -> queue_delayed_work -> ibmvfc_queuecommand_lck -> ibmvfc_send_event -> ibmvfc_send_crq - returns H_CLOSED <- returns SCSI_MLQUEUE_HOST_BUSY -> __blk_mq_requeue_request -> scmd_eh_abort_handler -> scsi_try_to_abort_cmd - returns SUCCESS -> scsi_queue_insert Normally, the SCMD_STATE_COMPLETE bit would protect against the command completion and the timeout, but that doesn't work here, since we don't check that at all in the SCSI_MLQUEUE_HOST_BUSY path. In this case we end up calling scsi_queue_insert on a request that has already been queued, or possibly even freed, and we crash. The patch below simply increases the default I/O timeout to avoid this race condition. This is also the timeout value that nearly all IBM SAN storage recommends setting as the default value. Link: https://lore.kernel.org/r/1610463998-19791-1-git-send-email-brking@linux.vnet.ibm.com Signed-off-by: Brian King Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/ibmvscsi/ibmvfc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index 04b3ac17531db..7865feb8e5e83 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c @@ -2891,8 +2891,10 @@ static int ibmvfc_slave_configure(struct scsi_device *sdev) unsigned long flags = 0; spin_lock_irqsave(shost->host_lock, flags); - if (sdev->type == TYPE_DISK) + if (sdev->type == TYPE_DISK) { sdev->allow_restart = 1; + blk_queue_rq_timeout(sdev->request_queue, 120 * HZ); + } spin_unlock_irqrestore(shost->host_lock, flags); return 0; } -- 2.27.0