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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 A36AFC4338F for ; Mon, 23 Aug 2021 06:14:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 763CE6127B for ; Mon, 23 Aug 2021 06:14:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233584AbhHWGOn (ORCPT ); Mon, 23 Aug 2021 02:14:43 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:53683 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231267AbhHWGOl (ORCPT ); Mon, 23 Aug 2021 02:14:41 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R451e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0UlCK-Sz_1629699238; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0UlCK-Sz_1629699238) by smtp.aliyun-inc.com(127.0.0.1); Mon, 23 Aug 2021 14:13:58 +0800 From: Jeffle Xu To: tytso@mit.edu, adilger.kernel@dilger.ca Cc: linux-ext4@vger.kernel.org, joseph.qi@linux.alibaba.com, enwlinux@gmail.com, hsiangkao@linux.alibaba.com Subject: [PATCH v2] ext4: fix reserved space counter leakage Date: Mon, 23 Aug 2021 14:13:58 +0800 Message-Id: <20210823061358.84473-1-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org When ext4_insert_delayed block receives and recovers from an error from ext4_es_insert_delayed_block(), e.g., ENOMEM, it does not release the space it has reserved for that block insertion as it should. One effect of this bug is that s_dirtyclusters_counter is not decremented and remains incorrectly elevated until the file system has been unmounted. This can result in premature ENOSPC returns and apparent loss of free space. Another effect of this bug is that /sys/fs/ext4//delayed_allocation_blocks can remain non-zero even after syncfs has been executed on the filesystem. Besides, add check for s_dirtyclusters_counter when inode is going to be evicted and freed. s_dirtyclusters_counter can still keep non-zero until inode is written back in .evict_inode(), and thus the check is delayed to .destroy_inode(). Fixes: 51865fda28e5 ("ext4: let ext4 maintain extent status tree") Cc: Suggested-by: Gao Xiang Signed-off-by: Jeffle Xu --- changes since v1: - improve commit log suggested by Eric Whitney - update "Suggested-by" title for Gao Xian, who actually found this bug code - add check for s_dirtyclusters_counter in .destroy_inode() --- fs/ext4/inode.c | 5 +++++ fs/ext4/super.c | 6 ++++++ 2 files changed, 11 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d8de607849df..73daf9443e5e 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1640,6 +1640,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); int ret; bool allocated = false; + bool reserved = false; /* * If the cluster containing lblk is shared with a delayed, @@ -1656,6 +1657,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) ret = ext4_da_reserve_space(inode); if (ret != 0) /* ENOSPC */ goto errout; + reserved = true; } else { /* bigalloc */ if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) { if (!ext4_es_scan_clu(inode, @@ -1668,6 +1670,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) ret = ext4_da_reserve_space(inode); if (ret != 0) /* ENOSPC */ goto errout; + reserved = true; } else { allocated = true; } @@ -1678,6 +1681,8 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) } ret = ext4_es_insert_delayed_block(inode, lblk, allocated); + if (ret && reserved) + ext4_da_release_space(inode, 1); errout: return ret; diff --git a/fs/ext4/super.c b/fs/ext4/super.c index dfa09a277b56..61bf52b58fca 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1351,6 +1351,12 @@ static void ext4_destroy_inode(struct inode *inode) true); dump_stack(); } + + if (EXT4_I(inode)->i_reserved_data_blocks) + ext4_msg(inode->i_sb, KERN_ERR, + "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!", + inode->i_ino, EXT4_I(inode), + EXT4_I(inode)->i_reserved_data_blocks); } static void init_once(void *foo) -- 2.27.0