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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 F222DC432C3 for ; Tue, 19 Nov 2019 08:40:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D50D9222AB for ; Tue, 19 Nov 2019 08:40:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726784AbfKSIkp (ORCPT ); Tue, 19 Nov 2019 03:40:45 -0500 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:48450 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726170AbfKSIkp (ORCPT ); Tue, 19 Nov 2019 03:40:45 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R391e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04446;MF=jiufei.xue@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0TiY3l-y_1574152835; Received: from ali-186590e05fa3.local(mailfrom:jiufei.xue@linux.alibaba.com fp:SMTPD_---0TiY3l-y_1574152835) by smtp.aliyun-inc.com(127.0.0.1); Tue, 19 Nov 2019 16:40:35 +0800 Subject: Re: [PATCH 1/2] vfs: add vfs_iocb_iter_[read|write] helper functions To: Amir Goldstein Cc: Miklos Szeredi , overlayfs , linux-fsdevel References: <1574129643-14664-1-git-send-email-jiufei.xue@linux.alibaba.com> <1574129643-14664-2-git-send-email-jiufei.xue@linux.alibaba.com> From: Jiufei Xue Message-ID: Date: Tue, 19 Nov 2019 16:40:35 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Amir, On 2019/11/19 上午11:14, Amir Goldstein wrote: > On Tue, Nov 19, 2019 at 4:14 AM Jiufei Xue wrote: >> >> This isn't cause any behavior changes and will be used by overlay >> async IO implementation. >> >> Signed-off-by: Jiufei Xue >> --- >> fs/read_write.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/fs.h | 16 +++++++++++++++ >> 2 files changed, 74 insertions(+) >> >> diff --git a/fs/read_write.c b/fs/read_write.c >> index 5bbf587..3dfbcec 100644 >> --- a/fs/read_write.c >> +++ b/fs/read_write.c >> @@ -984,6 +984,64 @@ ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, >> } >> EXPORT_SYMBOL(vfs_iter_write); >> >> +ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, >> + struct iov_iter *iter) >> +{ >> + ssize_t ret = 0; >> + ssize_t tot_len; >> + >> + if (!file->f_op->read_iter) >> + return -EINVAL; >> + if (!(file->f_mode & FMODE_READ)) >> + return -EBADF; >> + if (!(file->f_mode & FMODE_CAN_READ)) >> + return -EINVAL; >> + >> + tot_len = iov_iter_count(iter); >> + if (!tot_len) >> + return 0; >> + >> + ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); >> + if (ret < 0) >> + return ret; >> + >> + ret = call_read_iter(file, iocb, iter); >> + if (ret >= 0) >> + fsnotify_access(file); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL(vfs_iocb_iter_read); >> + >> +ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, >> + struct iov_iter *iter) >> +{ >> + ssize_t ret = 0; >> + ssize_t tot_len; >> + >> + if (!file->f_op->write_iter) >> + return -EINVAL; >> + if (!(file->f_mode & FMODE_WRITE)) >> + return -EBADF; >> + if (!(file->f_mode & FMODE_CAN_WRITE)) >> + return -EINVAL; >> + >> + tot_len = iov_iter_count(iter); >> + if (!tot_len) >> + return 0; >> + >> + ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); >> + if (ret < 0) >> + return ret; >> + >> + ret = call_write_iter(file, iocb, iter); >> + if (ret >= 0) >> + fsnotify_modify(file); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL(vfs_iocb_iter_write); >> + > > If it was up to me, I would pass down an optional iocb pointer > to the do_iter_XXX static helpers, instead of duplicating the code. > Others may find your approach cleaner, so let's see what other > people think. > Thanks for your review. I have considered your suggestion and still think that adding new helpers are more clearly. Let's wait for other people's opinions. Thanks, Jiufei > Thanks, > Amir. >