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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 7CEC9C4321A for ; Thu, 4 Mar 2021 00:27:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CBCF64E68 for ; Thu, 4 Mar 2021 00:27:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355083AbhCDASo (ORCPT ); Wed, 3 Mar 2021 19:18:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:40942 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1842785AbhCCINM (ORCPT ); Wed, 3 Mar 2021 03:13:12 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1614759144; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=I8MgoPWi0A/DEEHhPBXEgxuH6kqVoUyfUIdsEn236AY=; b=pONt1fdU991V35EOQAVrYaE/KnVnkkuNVpZ4ZEP8BWHB84/oDcChdP06vvoru2S3kdHSgd m3yTSEReuligYKvrn4AgdUpRsr55S8ad+JLDuDH7rJg3wq4sP0RsZ7tC9h7e1DOBUn3SY6 pIBD3UX8mH/UAzpRo+1HBfxQK0ZDcFk= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D751DAE88; Wed, 3 Mar 2021 08:12:24 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org, fstests@vger.kernel.org Subject: [PATCH 1/2] btrfs: use a dedicated variable for qgroup released data rsv for insert_prealloc_file_extent() Date: Wed, 3 Mar 2021 16:12:19 +0800 Message-Id: <20210303081220.80913-1-wqu@suse.com> X-Mailer: git-send-email 2.30.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org 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 --- I really want to go back time and slap my face. That damn naming, especially that "extent_info.qgroup_reserved = ret", wasted too long time. What the heck I was doing in the past?? --- fs/btrfs/inode.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4f2f1e932751..4e9717c29451 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9873,6 +9873,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent( struct btrfs_path *path; u64 start = ins->objectid; u64 len = ins->offset; + int qgroup_released; int ret; memset(&stack_fi, 0, sizeof(stack_fi)); @@ -9885,14 +9886,14 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent( btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE); /* Encryption and other encoding is reserved and all 0 */ - ret = btrfs_qgroup_release_data(inode, file_offset, len); - if (ret < 0) - return ERR_PTR(ret); + qgroup_released = btrfs_qgroup_release_data(inode, file_offset, len); + if (qgroup_released < 0) + return ERR_PTR(qgroup_released); if (trans) { ret = insert_reserved_file_extent(trans, inode, file_offset, &stack_fi, - true, ret); + true, qgroup_released); if (ret) return ERR_PTR(ret); return trans; @@ -9905,7 +9906,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent( extent_info.file_offset = file_offset; extent_info.extent_buf = (char *)&stack_fi; extent_info.is_new_extent = true; - extent_info.qgroup_reserved = ret; + extent_info.qgroup_reserved = qgroup_released; extent_info.insertions = 0; path = btrfs_alloc_path(); -- 2.30.1