From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932245AbaIRP7Z (ORCPT ); Thu, 18 Sep 2014 11:59:25 -0400 Received: from mail-pd0-f171.google.com ([209.85.192.171]:63404 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932123AbaIRP7W (ORCPT ); Thu, 18 Sep 2014 11:59:22 -0400 From: Ming Lei To: James Bottomley , Christoph Hellwig Cc: Jens Axboe , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Ming Lei Subject: [PATCH] scsi-mq: fix hw queue hang caused by timeout Date: Thu, 18 Sep 2014 23:59:10 +0800 Message-Id: <1411055950-28657-1-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If there are two requests or more timed out, the dispatch queue is put into stopped state and never be recoverd, and there is no such problem in non-mq mode. This patch trys to recover the stopped queue when the queue becomes unbusy, then the following retries can move on. Basically this patch maintains same behavior for this situation with non-mq mode. Signed-off-by: Ming Lei --- drivers/scsi/scsi_lib.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 3b92c39..dfbc028 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -142,6 +142,8 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) struct scsi_device *device = cmd->device; struct request_queue *q = device->request_queue; unsigned long flags; + bool restart = false; + bool blocked = !!atomic_read(&device->device_blocked); SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, "Inserting command %p into mlqueue\n", cmd)); @@ -152,9 +154,14 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) * Decrement the counters, since these commands are no longer * active on the host/device. */ - if (unbusy) + if (unbusy) { scsi_device_unbusy(device); + /* need to restart hw queue if it was stopped */ + if (!atomic_read(&device->device_busy) && blocked) + restart = true; + } + /* * Requeue this command. It will go before all other commands * that are already in the queue. Schedule requeue work under @@ -164,6 +171,8 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) cmd->result = 0; if (q->mq_ops) { scsi_mq_requeue_cmd(cmd); + if (restart) + blk_mq_start_stopped_hw_queues(q, true); return; } spin_lock_irqsave(q->queue_lock, flags); -- 1.7.9.5