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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 AD705C433ED for ; Thu, 6 May 2021 10:19:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B6656054E for ; Thu, 6 May 2021 10:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233893AbhEFKUP (ORCPT ); Thu, 6 May 2021 06:20:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:55002 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233416AbhEFKUP (ORCPT ); Thu, 6 May 2021 06:20:15 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 014D8B175; Thu, 6 May 2021 10:19:16 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 7575F1F2C60; Thu, 6 May 2021 12:19:15 +0200 (CEST) Date: Thu, 6 May 2021 12:19:15 +0200 From: Jan Kara To: yebin Cc: Jan Kara , tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] ext4: Fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed Message-ID: <20210506101915.GA22189@quack2.suse.cz> References: <20210428085158.3728201-1-yebin10@huawei.com> <20210430125853.GB5315@quack2.suse.cz> <60921135.3030900@huawei.com> <20210505104105.GA29867@quack2.suse.cz> <6093A830.3000704@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6093A830.3000704@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Thu 06-05-21 16:26:24, yebin wrote: > Thanks for your suggesttion. If you have no objection to following > modification, i will send it as V4. > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 77c84d6f1af6..f9cbd11e1eae 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -3206,7 +3206,10 @@ static int ext4_split_extent_at(handle_t *handle, > ext4_ext_mark_unwritten(ex2); > > err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags); > - if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { > + if (err != -ENOSPC && err != -EDQUOT) > + goto out; > + > + if (EXT4_EXT_MAY_ZEROOUT & split_flag) { You need: if (err && (EXT4_EXT_MAY_ZEROOUT & split_flag)) there, don't you? You don't want to zero-out if there's no error. > @@ -3232,22 +3235,23 @@ static int ext4_split_extent_at(handle_t *handle, > ext4_ext_pblock(&orig_ex)); > } > > - if (err) > - goto fix_extent_len; > - /* update the extent length and mark as initialized */ > - ex->ee_len = cpu_to_le16(ee_len); > - ext4_ext_try_to_merge(handle, inode, path, ex); > - err = ext4_ext_dirty(handle, inode, path + path->p_depth); > - if (err) > - goto fix_extent_len; > - > - /* update extent status tree */ > - err = ext4_zeroout_es(inode, &zero_ex); > - > - goto out; > - } else if (err) > - goto fix_extent_len; > - > + if (!err) { > + /* update the extent length and mark as initialized > */ > + ex->ee_len = cpu_to_le16(ee_len); > + ext4_ext_try_to_merge(handle, inode, path, ex); > + err = ext4_ext_dirty(handle, inode, path + > path->p_depth); > + if (!err) > + /* update extent status tree */ > + err = ext4_zeroout_es(inode, &zero_ex); > + /* At here, ext4_ext_try_to_merge maybe already > merge > + * extent, if fix origin extent length may lead to > + * overwritten. > + */ I'd rephrase the comment as: /* * If we failed at this point, we don't know in which state the extent tree * exactly is so don't try to fix length of the original extent as it may do * even more damage. */ > + goto out; > + } > + } > + if (err) > + goto fix_extent_len; And you can move this if (err) before if (!err) above to make code easier to read and save one indentation level. > out: > ext4_ext_show_leaf(inode, path); > return err; > > Honza -- Jan Kara SUSE Labs, CR