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, 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 C7FE5C38A2A for ; Fri, 8 May 2020 06:50:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 982FD20870 for ; Fri, 8 May 2020 06:50:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726207AbgEHGuV (ORCPT ); Fri, 8 May 2020 02:50:21 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:33446 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725971AbgEHGuV (ORCPT ); Fri, 8 May 2020 02:50:21 -0400 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id D6EC0D4A70CC61C5C7D9; Fri, 8 May 2020 14:50:15 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.205) with Microsoft SMTP Server (TLS) id 14.3.487.0; Fri, 8 May 2020 14:50:11 +0800 Subject: Re: [f2fs-dev] [PATCH] f2fs: remove race condition in releasing cblocks To: Daeho Jeong , , , CC: Daeho Jeong References: <20200508042506.143395-1-daeho43@gmail.com> From: Chao Yu Message-ID: <4dfb73d9-03a0-bb2f-a112-1dd42db4d7bb@huawei.com> Date: Fri, 8 May 2020 14:50:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200508042506.143395-1-daeho43@gmail.com> 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 2020/5/8 12:25, Daeho Jeong wrote: > From: Daeho Jeong > > Now, if writing pages and releasing compress blocks occur > simultaneously, and releasing cblocks is executed more than one time > to a file, then total block count of filesystem and block count of the > file could be incorrect and damaged. > > We have to execute releasing compress blocks only one time for a file > without being interfered by writepages path. > > Signed-off-by: Daeho Jeong > --- > fs/f2fs/file.c | 31 ++++++++++++++++++++++++------- > 1 file changed, 24 insertions(+), 7 deletions(-) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index 4aab4b42d8ba..a92bc51b9b28 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -3488,6 +3488,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg) > pgoff_t page_idx = 0, last_idx; > unsigned int released_blocks = 0; > int ret; > + int writecount; > > if (!f2fs_sb_has_compression(F2FS_I_SB(inode))) > return -EOPNOTSUPP; Before inode_lock(), there is one case we may jump to out label, in this case, we may unlock inode incorrectly. if (!F2FS_I(inode)->i_compr_blocks) goto out; > - > - inode_unlock(inode); > out: > + inode_unlock(inode); > + > mnt_drop_write_file(filp); Thanks,