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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 06DE7C43465 for ; Mon, 21 Sep 2020 15:50:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A71D52220C for ; Mon, 21 Sep 2020 15:50:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727949AbgIUPuv convert rfc822-to-8bit (ORCPT ); Mon, 21 Sep 2020 11:50:51 -0400 Received: from smtp.h3c.com ([60.191.123.50]:24952 "EHLO h3cspam02-ex.h3c.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727300AbgIUPuv (ORCPT ); Mon, 21 Sep 2020 11:50:51 -0400 Received: from DAG2EX07-IDC.srv.huawei-3com.com ([10.8.0.70]) by h3cspam02-ex.h3c.com with ESMTPS id 08LFn5r7084222 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 21 Sep 2020 23:49:05 +0800 (GMT-8) (envelope-from tian.xianting@h3c.com) Received: from DAG2EX03-BASE.srv.huawei-3com.com (10.8.0.66) by DAG2EX07-IDC.srv.huawei-3com.com (10.8.0.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Mon, 21 Sep 2020 23:49:09 +0800 Received: from DAG2EX03-BASE.srv.huawei-3com.com ([fe80::5d18:e01c:bbbd:c074]) by DAG2EX03-BASE.srv.huawei-3com.com ([fe80::5d18:e01c:bbbd:c074%7]) with mapi id 15.01.1713.004; Mon, 21 Sep 2020 23:49:09 +0800 From: Tianxianting To: Keith Busch CC: "axboe@fb.com" , "hch@lst.de" , "sagi@grimberg.me" , "linux-nvme@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] nvme: replace meaningless judgement by checking whether req is null Thread-Topic: [PATCH] nvme: replace meaningless judgement by checking whether req is null Thread-Index: AQHWj71pi81Rb9ZmlEuvVhznKWqiEqlyrIIAgACJanA= Date: Mon, 21 Sep 2020 15:49:09 +0000 Message-ID: References: <20200921021052.10462-1-tian.xianting@h3c.com> <20200921150824.GA4034182@dhcp-10-100-145-180.wdl.wdc.com> In-Reply-To: <20200921150824.GA4034182@dhcp-10-100-145-180.wdl.wdc.com> Accept-Language: en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.99.141.128] x-sender-location: DAG2 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-DNSRBL: X-MAIL: h3cspam02-ex.h3c.com 08LFn5r7084222 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org HI Keith, Thanks for your comments, I will submit a new patch of version 2 for the further reviewing, v2 patch will contains: 1, retain existing judgement and dev_warn; 2, add the check whether req is null(already did in this patch) 3, simplify and make the changelog succinct according to you said " This is what I'm thinking:". Is it right? Should I retain the nvme_irq crash log in changelog, mention the difference between nvmeq->q_depth and tagset queue_depth? Thanks -----Original Message----- From: Keith Busch [mailto:kbusch@kernel.org] Sent: Monday, September 21, 2020 11:08 PM To: tianxianting (RD) Cc: axboe@fb.com; hch@lst.de; sagi@grimberg.me; linux-nvme@lists.infradead.org; linux-kernel@vger.kernel.org Subject: Re: [PATCH] nvme: replace meaningless judgement by checking whether req is null On Mon, Sep 21, 2020 at 10:10:52AM +0800, Xianting Tian wrote: > @@ -940,13 +940,6 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) > struct nvme_completion *cqe = &nvmeq->cqes[idx]; > struct request *req; > > - if (unlikely(cqe->command_id >= nvmeq->q_depth)) { > - dev_warn(nvmeq->dev->ctrl.device, > - "invalid id %d completed on queue %d\n", > - cqe->command_id, le16_to_cpu(cqe->sq_id)); > - return; > - } > - > /* > * AEN requests are special as they don't time out and can > * survive any kind of queue freeze and often don't respond to @@ > -960,6 +953,13 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) > } > > req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), cqe->command_id); > + if (unlikely(!req)) { > + dev_warn(nvmeq->dev->ctrl.device, > + "req is null for tag %d completed on queue %d\n", > + cqe->command_id, le16_to_cpu(cqe->sq_id)); > + return; > + } This is making sense now, though I think we should retain the existing dev_warn() since it's still accurate and provides continuity for people who are used to looking for these sorts of messages. Your changelog is a bit much though. I think we can say it a bit more succinctly. This is what I'm thinking: The driver registers interrupts for queues before initializing the tagset because it uses the number of successful request_irq() calls to configure the tagset parameters. This allows a race condition with the current tag validity check if the controller happens to produce an interrupt with a corrupted CQE before the tagset is initialized. Replace the driver's indirect tag check with the one already provided by the block layer. 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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 2CF53C43465 for ; Mon, 21 Sep 2020 15:50:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 D578D221EC for ; Mon, 21 Sep 2020 15:50:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="WNGhO2y0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D578D221EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=h3c.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=18T9+36V3+V57+e83whn1JrGfKjvVGXDe3YCb/NL9tE=; b=WNGhO2y0HQrviACSJVTzZitew NXyKD5Sdv60RP+yRDObIqVSS5eSk68xEvyAvnNJBk7F0M0m0L2h+SwFKyfpntBC1t61fXioohJJ1M WF9lVXi61lyAPV0P557t2ZB0qkXCW2O00mFwf6shzfE1EvLmzPrY9TzxcBjhSnqm8j2kvfCVN4ABG mTK13jL7hmChUyrIWQCL4VkCMxU264UCAq7NcpKgFmyG0te7VNysy/VL09Do7aOQocrpj+Jd++MvQ /n2rDmS9c1nOBS0iOZJG4yHW/RkCottyQcRYyBqXKzBheLHdRKiJVPcU5mvvopQPkdZwH7IQXxvND XTBvWkO+A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKO5C-00050v-Pq; Mon, 21 Sep 2020 15:50:26 +0000 Received: from smtp.h3c.com ([60.191.123.50] helo=h3cspam02-ex.h3c.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKO55-0004wG-Q7 for linux-nvme@lists.infradead.org; Mon, 21 Sep 2020 15:50:24 +0000 Received: from DAG2EX07-IDC.srv.huawei-3com.com ([10.8.0.70]) by h3cspam02-ex.h3c.com with ESMTPS id 08LFn5r7084222 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 21 Sep 2020 23:49:05 +0800 (GMT-8) (envelope-from tian.xianting@h3c.com) Received: from DAG2EX03-BASE.srv.huawei-3com.com (10.8.0.66) by DAG2EX07-IDC.srv.huawei-3com.com (10.8.0.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Mon, 21 Sep 2020 23:49:09 +0800 Received: from DAG2EX03-BASE.srv.huawei-3com.com ([fe80::5d18:e01c:bbbd:c074]) by DAG2EX03-BASE.srv.huawei-3com.com ([fe80::5d18:e01c:bbbd:c074%7]) with mapi id 15.01.1713.004; Mon, 21 Sep 2020 23:49:09 +0800 From: Tianxianting To: Keith Busch Subject: RE: [PATCH] nvme: replace meaningless judgement by checking whether req is null Thread-Topic: [PATCH] nvme: replace meaningless judgement by checking whether req is null Thread-Index: AQHWj71pi81Rb9ZmlEuvVhznKWqiEqlyrIIAgACJanA= Date: Mon, 21 Sep 2020 15:49:09 +0000 Message-ID: References: <20200921021052.10462-1-tian.xianting@h3c.com> <20200921150824.GA4034182@dhcp-10-100-145-180.wdl.wdc.com> In-Reply-To: <20200921150824.GA4034182@dhcp-10-100-145-180.wdl.wdc.com> Accept-Language: en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.99.141.128] x-sender-location: DAG2 MIME-Version: 1.0 X-DNSRBL: X-MAIL: h3cspam02-ex.h3c.com 08LFn5r7084222 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200921_115022_069407_413039BF X-CRM114-Status: GOOD ( 15.17 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "axboe@fb.com" , "linux-kernel@vger.kernel.org" , "hch@lst.de" , "linux-nvme@lists.infradead.org" , "sagi@grimberg.me" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org HI Keith, Thanks for your comments, I will submit a new patch of version 2 for the further reviewing, v2 patch will contains: 1, retain existing judgement and dev_warn; 2, add the check whether req is null(already did in this patch) 3, simplify and make the changelog succinct according to you said " This is what I'm thinking:". Is it right? Should I retain the nvme_irq crash log in changelog, mention the difference between nvmeq->q_depth and tagset queue_depth? Thanks -----Original Message----- From: Keith Busch [mailto:kbusch@kernel.org] Sent: Monday, September 21, 2020 11:08 PM To: tianxianting (RD) Cc: axboe@fb.com; hch@lst.de; sagi@grimberg.me; linux-nvme@lists.infradead.org; linux-kernel@vger.kernel.org Subject: Re: [PATCH] nvme: replace meaningless judgement by checking whether req is null On Mon, Sep 21, 2020 at 10:10:52AM +0800, Xianting Tian wrote: > @@ -940,13 +940,6 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) > struct nvme_completion *cqe = &nvmeq->cqes[idx]; > struct request *req; > > - if (unlikely(cqe->command_id >= nvmeq->q_depth)) { > - dev_warn(nvmeq->dev->ctrl.device, > - "invalid id %d completed on queue %d\n", > - cqe->command_id, le16_to_cpu(cqe->sq_id)); > - return; > - } > - > /* > * AEN requests are special as they don't time out and can > * survive any kind of queue freeze and often don't respond to @@ > -960,6 +953,13 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) > } > > req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), cqe->command_id); > + if (unlikely(!req)) { > + dev_warn(nvmeq->dev->ctrl.device, > + "req is null for tag %d completed on queue %d\n", > + cqe->command_id, le16_to_cpu(cqe->sq_id)); > + return; > + } This is making sense now, though I think we should retain the existing dev_warn() since it's still accurate and provides continuity for people who are used to looking for these sorts of messages. Your changelog is a bit much though. I think we can say it a bit more succinctly. This is what I'm thinking: The driver registers interrupts for queues before initializing the tagset because it uses the number of successful request_irq() calls to configure the tagset parameters. This allows a race condition with the current tag validity check if the controller happens to produce an interrupt with a corrupted CQE before the tagset is initialized. Replace the driver's indirect tag check with the one already provided by the block layer. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme