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[209.132.180.67]) by mx.google.com with ESMTP id q6-v6si3055576plr.134.2018.06.13.07.28.14; Wed, 13 Jun 2018 07:28:29 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935818AbeFMO1q (ORCPT + 99 others); Wed, 13 Jun 2018 10:27:46 -0400 Received: from verein.lst.de ([213.95.11.211]:41275 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935560AbeFMO1p (ORCPT ); Wed, 13 Jun 2018 10:27:45 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id 6840168DBC; Wed, 13 Jun 2018 16:35:58 +0200 (CEST) Date: Wed, 13 Jun 2018 16:35:58 +0200 From: "hch@lst.de" To: Bart Van Assche Cc: "hch@lst.de" , "jianchao.w.wang@oracle.com" , "randrianasulu@gmail.com" , "rdunlap@infradead.org" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "linux-block@vger.kernel.org" Subject: Re: kernel BUG at drivers/scsi/scsi_error.c:197! - git 4.17.0-x64-08428-g7d3bf613e99a Message-ID: <20180613143558.GA1163@lst.de> References: <201806091606.51078.randrianasulu@gmail.com> <025bf705-15b0-65e5-4b16-6c91d41c1730@infradead.org> <40617b19667b3c1302f8a903c19f2fa2f409b12a.camel@wdc.com> <5ca74fb7-af70-31c3-0e3f-bace058e5a57@oracle.com> <20180613140411.GA32701@lst.de> <09e8bd7605febd091679172d68ca1e9ca3990c91.camel@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <09e8bd7605febd091679172d68ca1e9ca3990c91.camel@wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 13, 2018 at 02:08:12PM +0000, Bart Van Assche wrote: > __blk_mq_complete_request() is already called today by blk_mq_complete_request(). > However, it's not clear to me why that function is exported by Jianchao's patch. True. I had missed that the patch also started calling the new mark_rq_complete function from the error handler. > The SCSI error handler already waits until all pending requests have finished > before it starts handling timed out commands. This e-mail thread started with a > report of a crash in the SCSI error handler, which is a regression introduced in > the v4.18 merge window. ut-requests-again-that-are-in-the.patch Yeah. I've read back a bit. If your theory of a double invocation of the timeout handler is correct something like the patch below should sort it out, right? --- From d408928360f087c0ad24e31d1d25533c698b8b35 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 13 Jun 2018 16:25:40 +0200 Subject: blk-mq: don't time out requests again that are in the timeout handler Signed-off-by: Christoph Hellwig --- block/blk-mq.c | 4 ++++ include/linux/blkdev.h | 2 ++ 2 files changed, 6 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index e9da5e6a8526..8a2895fed078 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -770,6 +770,7 @@ EXPORT_SYMBOL(blk_mq_tag_to_rq); static void blk_mq_rq_timed_out(struct request *req, bool reserved) { + req->rq_flags |= RQF_TIMED_OUT; if (req->q->mq_ops->timeout) { enum blk_eh_timer_return ret; @@ -779,6 +780,7 @@ static void blk_mq_rq_timed_out(struct request *req, bool reserved) WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER); } + req->rq_flags &= ~RQF_TIMED_OUT; blk_add_timer(req); } @@ -788,6 +790,8 @@ static bool blk_mq_req_expired(struct request *rq, unsigned long *next) if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT) return false; + if (rq->rq_flags & RQF_TIMED_OUT) + return false; deadline = blk_rq_deadline(rq); if (time_after_eq(jiffies, deadline)) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index bca3a92eb55f..fa6f11751430 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -127,6 +127,8 @@ typedef __u32 __bitwise req_flags_t; #define RQF_ZONE_WRITE_LOCKED ((__force req_flags_t)(1 << 19)) /* already slept for hybrid poll */ #define RQF_MQ_POLL_SLEPT ((__force req_flags_t)(1 << 20)) +/* ->timeout has been called, don't expire again */ +#define RQF_TIMED_OUT ((__force req_flags_t)(1 << 21)) /* flags that prevent us from merging requests: */ #define RQF_NOMERGE_FLAGS \ -- 2.17.1