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_CR_TRAILER,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 0AE13C433C1 for ; Thu, 25 Mar 2021 12:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C312061A0A for ; Thu, 25 Mar 2021 12:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229626AbhCYMKQ (ORCPT ); Thu, 25 Mar 2021 08:10:16 -0400 Received: from mx2.suse.de ([195.135.220.15]:38568 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230134AbhCYMKK (ORCPT ); Thu, 25 Mar 2021 08:10:10 -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 A956DAC16; Thu, 25 Mar 2021 12:10:08 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id D2F70DA732; Thu, 25 Mar 2021 13:08:02 +0100 (CET) Date: Thu, 25 Mar 2021 13:08:02 +0100 From: David Sterba To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Qu Wenruo , David Sterba , linux-btrfs@vger.kernel.org Subject: Re: [PATCH AUTOSEL 5.11 26/44] btrfs: track qgroup released data in own variable in insert_prealloc_file_extent Message-ID: <20210325120802.GK7604@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Qu Wenruo , David Sterba , linux-btrfs@vger.kernel.org References: <20210325112459.1926846-1-sashal@kernel.org> <20210325112459.1926846-26-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210325112459.1926846-26-sashal@kernel.org> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Mar 25, 2021 at 07:24:41AM -0400, Sasha Levin wrote: > From: Qu Wenruo > > [ Upstream commit fbf48bb0b197e6894a04c714728c952af7153bf3 ] > > There is a piece of weird code in insert_prealloc_file_extent(), which > looks like: > > ret = btrfs_qgroup_release_data(inode, file_offset, len); > if (ret < 0) > return ERR_PTR(ret); > if (trans) { > ret = insert_reserved_file_extent(trans, inode, > file_offset, &stack_fi, > true, ret); > ... > } > extent_info.is_new_extent = true; > extent_info.qgroup_reserved = ret; > ... > > Note how the variable @ret is abused here, and if anyone is adding code > just after btrfs_qgroup_release_data() call, it's super easy to > overwrite the @ret and cause tons of qgroup related bugs. > > Fix such abuse by introducing new variable @qgroup_released, so that we > won't reuse the existing variable @ret. > > Signed-off-by: Qu Wenruo > Reviewed-by: David Sterba > Signed-off-by: David Sterba > Signed-off-by: Sasha Levin This patch is a preparatory work and does not make sense for backport standalone. Either this one plus https://lore.kernel.org/linux-btrfs/20210303104152.105877-2-wqu@suse.com/ or neither. And IIRC it does not apply directly and needs some additional review before it can be backported to older code base, so it has no CC: stable tags.