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 C13DFC04A68 for ; Wed, 27 Jul 2022 08:04:09 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=SX+SAPi0PuBpuc51AcvEoIL1Fxn1q7bCsIFy2xkGFkA=; b=sCzIxvT7l6dNbcNv9pX00Fm8Oa uPA8FN+NgVO8jS7cI/aiIOk7yfkXlLO5y/8pBX9ANeSyHMheVhZxgsAo3Fih2ShnN8k2ui+No3Zx1 iQlDIpOUVGsf/bUhewV+rhvpHUiT4mzALHgjX5HAvKdW/2g4iiP9ZMEaEpXuee3ieIbnc3MQKUZ44 MPuNWIw1mLYVLriLxI9zC0JQ+M0TllVrx/TEU9T1GpawhSepYKnNsb8r6at1An5H8EOpU785A+0xI knF1waQZWC5oMhIlFQK8xcHbKwOiQ9N1K0D8bpisJHUgD8GdL9sbgE0eY9X4K46UjGIRG7xPHwc0t gsI4/EwA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oGc1W-00At5K-FD; Wed, 27 Jul 2022 08:04:06 +0000 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oGc1R-00AsqF-KG for linux-nvme@lists.infradead.org; Wed, 27 Jul 2022 08:04:04 +0000 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=kanie@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0VKZyJt5_1658909024; Received: from 30.0.176.8(mailfrom:kanie@linux.alibaba.com fp:SMTPD_---0VKZyJt5_1658909024) by smtp.aliyun-inc.com; Wed, 27 Jul 2022 16:03:44 +0800 Message-ID: <5a28ee53-0bed-11ab-6817-e60f2ca70ed9@linux.alibaba.com> Date: Wed, 27 Jul 2022 16:03:43 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v2] nvmet: avoid unnecessary fsync and flush bio To: Christoph Hellwig Cc: sagi@grimberg.me, kch@nvidia.com, linux-nvme@lists.infradead.org References: <1658730498-11857-1-git-send-email-kanie@linux.alibaba.com> <20220726113333.GA2867@lst.de> From: Guixin Liu In-Reply-To: <20220726113333.GA2867@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220727_010402_378114_1599A9BA X-CRM114-Status: UNSURE ( 6.98 ) X-CRM114-Notice: Please train this message. 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 在 2022/7/26 19:33, Christoph Hellwig 写道: > On Mon, Jul 25, 2022 at 02:28:18PM +0800, Guixin Liu wrote: >> u16 nvmet_file_flush(struct nvmet_req *req) >> { >> - return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1)); >> + if (req->ns->buffered_io) >> + return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1)); >> + return NVME_SC_SUCCESS; > This is broken. Even direct I/O needs an fsync to commit metadata > changes. Well, you are right, I will send V3 patch with remove this change. Thanks, Guixin Liu