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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 D1EB3C4CEC7 for ; Mon, 16 Sep 2019 08:23:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B105B20890 for ; Mon, 16 Sep 2019 08:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727505AbfIPIXB (ORCPT ); Mon, 16 Sep 2019 04:23:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:47230 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727068AbfIPIXB (ORCPT ); Mon, 16 Sep 2019 04:23:01 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 37F62B664; Mon, 16 Sep 2019 08:22:59 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id E309C1E47E5; Mon, 16 Sep 2019 10:23:06 +0200 (CEST) Date: Mon, 16 Sep 2019 10:23:06 +0200 From: Jan Kara To: Chao Yu Cc: Jan Kara , Jan Kara , chao@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] quota: fix wrong condition in is_quota_modification() Message-ID: <20190916082306.GB2485@quack2.suse.cz> References: <20190911093650.35329-1-yuchao0@huawei.com> <20190912100610.GA14773@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon 16-09-19 10:53:08, Chao Yu wrote: > On 2019/9/12 18:06, Jan Kara wrote: > > On Wed 11-09-19 17:36:50, Chao Yu wrote: > >> diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h > >> index dc905a4ff8d7..bd30acad3a7f 100644 > >> --- a/include/linux/quotaops.h > >> +++ b/include/linux/quotaops.h > >> @@ -22,7 +22,7 @@ static inline struct quota_info *sb_dqopt(struct super_block *sb) > >> /* i_mutex must being held */ > >> static inline bool is_quota_modification(struct inode *inode, struct iattr *ia) > >> { > >> - return (ia->ia_valid & ATTR_SIZE && ia->ia_size != inode->i_size) || > >> + return (ia->ia_valid & ATTR_SIZE && ia->ia_size <= inode->i_size) || > >> (ia->ia_valid & ATTR_UID && !uid_eq(ia->ia_uid, inode->i_uid)) || > >> (ia->ia_valid & ATTR_GID && !gid_eq(ia->ia_gid, inode->i_gid)); > >> } > > > > OK, but your change makes i_size extension not to be quota modification > > I just try to adapt below rules covered with generic/092, which restrict > to not trim preallocate blocks beyond i_size, in that case, filesystem > won't change i_blocks. > > 1) truncate(i_size) will trim all blocks past i_size. > 2) truncate(x) where x > i_size will not trim all blocks past i_size. Ah, OK. > However, I'm okay with your change, because there could be filesystems won't > follow above rule. Yes, I'm concerned that some filesystem may change i_blocks in some corner case when growing inode size (e.g. when it decides to convert inode from inline format to a normal block based format or something like that). So I don't think the optimization is really worth the chance for breakage. Honza -- Jan Kara SUSE Labs, CR