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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 4BBE7C43143 for ; Fri, 22 Jun 2018 07:39:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08920223D8 for ; Fri, 22 Jun 2018 07:39:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08920223D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751526AbeFVHjT (ORCPT ); Fri, 22 Jun 2018 03:39:19 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:8681 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750983AbeFVHjR (ORCPT ); Fri, 22 Jun 2018 03:39:17 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 7BA983DF630BC; Fri, 22 Jun 2018 15:39:03 +0800 (CST) Received: from [127.0.0.1] (10.134.22.195) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.382.0; Fri, 22 Jun 2018 15:39:03 +0800 Subject: Re: [PATCH] f2fs: assign REQ_RAHEAD to bio for ->readpages To: Jaegeuk Kim , , CC: Jens Axboe References: <20180621193213.86850-1-jaegeuk@kernel.org> From: Chao Yu Message-ID: Date: Fri, 22 Jun 2018 15:38:41 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180621193213.86850-1-jaegeuk@kernel.org> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/6/22 3:32, Jaegeuk Kim wrote: > As Jens reported, we'd better assign REQ_RAHEAD to bio by the fact that > ->readpages is called only from read-ahead. > > In Documentation/filesystems/vfs.txt, > > readpages: called by the VM to read pages associated with the address_space > object. This is essentially just a vector version of > readpage. Instead of just one page, several pages are > requested. > readpages is only used for read-ahead, so read errors are > ignored. If anything goes wrong, feel free to give up. > > Signed-off-by: Jens Axboe > Signed-off-by: Jaegeuk Kim Reviewed-by: Chao Yu Thanks,