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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 21542C4332F for ; Wed, 21 Dec 2022 08:22:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+ci5bcUIbLGxQVgLgfmHm24kEGwwT3UbgpEsz57UQFg=; b=GXMIYngtsyDtPkyEHfhO8WYY22 glK+QyoYo2bCKqK6gV9WeXKsE2J5yddxRZQ8klnLksxsVhhc3aAVKFNrgJZBpCmsSUCciJIJd8fXn cSXUgrChDTojJmdvF04kN3z7t5sS/tVKFNBwFxDQ+9MO4oqfboLGnP++R5FgU8a9+MUKo/roQnhkD gIj74q70aU0l4fg6hx7ZOR3oFzAKBggdoPdKon5wmzMJ+DNSKW+/2wMZyQyZCXem1fqEoZBTYohVd PSoaknhc/63EpYk/ZK81T4B1nGRIAM5LnTPL8t2lJugNITgdQdS67tXamrWIImRpYFNCIjxBz3QoX rxt4SpDQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7uMe-00C65l-Um; Wed, 21 Dec 2022 08:22:13 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7uM3-00C5iv-RO for linux-nvme@lists.infradead.org; Wed, 21 Dec 2022 08:21:37 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id BFFC267373; Wed, 21 Dec 2022 09:21:31 +0100 (CET) Date: Wed, 21 Dec 2022 09:21:31 +0100 From: Christoph Hellwig To: zhangyanjun@cestc.cn Cc: sagi@grimberg.me, axboe@kernel.dk, kbusch@kernel.org, axboe@fb.com, hch@lst.de, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org Subject: Re: [PATCH v2] nvme: fix multipath crash caused by flush request when blktrace is enabled Message-ID: <20221221082131.GA23644@lst.de> References: <20221220063233.43932-1-zhangyanjun@cestc.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221220063233.43932-1-zhangyanjun@cestc.cn> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221221_002136_106142_863D7342 X-CRM114-Status: GOOD ( 10.66 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Just checking for ->bio seems to be: - simpler - faster and does not require block layer internals. So why not just this: diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 6bbb73ef8b2548..424c8a467a0c2a 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -893,7 +893,7 @@ static inline void nvme_trace_bio_complete(struct request *req) { struct nvme_ns *ns = req->q->queuedata; - if (req->cmd_flags & REQ_NVME_MPATH) + if ((req->cmd_flags & REQ_NVME_MPATH) && req->bio) trace_block_bio_complete(ns->head->disk->queue, req->bio); }