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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D4AC0C433E1 for ; Mon, 24 Aug 2020 17:31:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B08F3206F0 for ; Mon, 24 Aug 2020 17:31:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598290274; bh=QjxMfSf2YtZfIdIMF/+YbXzKaCbtEZ/DX8R9gXNGh6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=saNZD0qkAlke8N13E/8LiNcmt9RkxIUBo8DJOEDVRqugQFmH5Zhef5bovdz4XNNF7 dDE+gwrQfB9VvrxZbZ6cMGqm/WnJqJFuAXwqI7Aw3u+5GzwTIP+qbCGxT0qeBlyJWZ k8RepAZVEgxOvSQW+HtwIecYK8jgi6F+RRgH0Z5M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728479AbgHXRbO (ORCPT ); Mon, 24 Aug 2020 13:31:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:39214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728133AbgHXQfR (ORCPT ); Mon, 24 Aug 2020 12:35:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 22B4222BEF; Mon, 24 Aug 2020 16:35:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598286913; bh=QjxMfSf2YtZfIdIMF/+YbXzKaCbtEZ/DX8R9gXNGh6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KVRgzpb5cxpYPde2hvxF9723pINnn5nJk6L1tAO4fNVs9YIHPVnIoum8T5l8EjsB5 xOi45PQ9hHV8AZ8hbfSQBITO/6sS9c6KMXtrnO+Elzqyrv/9wMvrMtiHSLB8oAOsT6 4Fb0nJKmSKARsThGtP1iyJUeFt4FGanYiuqqFTi8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "zhangyi (F)" , Jan Kara , Theodore Ts'o , Sasha Levin , linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 5.8 07/63] ext4: abort the filesystem if failed to async write metadata buffer Date: Mon, 24 Aug 2020 12:34:07 -0400 Message-Id: <20200824163504.605538-7-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200824163504.605538-1-sashal@kernel.org> References: <20200824163504.605538-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "zhangyi (F)" [ Upstream commit bc71726c725767205757821df364acff87f92ac5 ] There is a risk of filesystem inconsistency if we failed to async write back metadata buffer in the background. Because of current buffer's end io procedure is handled by end_buffer_async_write() in the block layer, and it only clear the buffer's uptodate flag and mark the write_io_error flag, so ext4 cannot detect such failure immediately. In most cases of getting metadata buffer (e.g. ext4_read_inode_bitmap()), although the buffer's data is actually uptodate, it may still read data from disk because the buffer's uptodate flag has been cleared. Finally, it may lead to on-disk filesystem inconsistency if reading old data from the disk successfully and write them out again. This patch detect bdev mapping->wb_err when getting journal's write access and mark the filesystem error if bdev's mapping->wb_err was increased, this could prevent further writing and potential inconsistency. Signed-off-by: zhangyi (F) Suggested-by: Jan Kara Link: https://lore.kernel.org/r/20200620025427.1756360-2-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/ext4.h | 3 +++ fs/ext4/ext4_jbd2.c | 25 +++++++++++++++++++++++++ fs/ext4/super.c | 17 +++++++++++++++++ 3 files changed, 45 insertions(+) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 42f5060f3cdf1..6a76bd94277f0 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1585,6 +1585,9 @@ struct ext4_sb_info { #ifdef CONFIG_EXT4_DEBUG unsigned long s_simulate_fail; #endif + /* Record the errseq of the backing block device */ + errseq_t s_bdev_wb_err; + spinlock_t s_bdev_wb_lock; }; static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb) diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index 0c76cdd44d90d..760b9ee49dc00 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -195,6 +195,28 @@ static void ext4_journal_abort_handle(const char *caller, unsigned int line, jbd2_journal_abort_handle(handle); } +static void ext4_check_bdev_write_error(struct super_block *sb) +{ + struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; + struct ext4_sb_info *sbi = EXT4_SB(sb); + int err; + + /* + * If the block device has write error flag, it may have failed to + * async write out metadata buffers in the background. In this case, + * we could read old data from disk and write it out again, which + * may lead to on-disk filesystem inconsistency. + */ + if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) { + spin_lock(&sbi->s_bdev_wb_lock); + err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err); + spin_unlock(&sbi->s_bdev_wb_lock); + if (err) + ext4_error_err(sb, -err, + "Error while async write back metadata"); + } +} + int __ext4_journal_get_write_access(const char *where, unsigned int line, handle_t *handle, struct buffer_head *bh) { @@ -202,6 +224,9 @@ int __ext4_journal_get_write_access(const char *where, unsigned int line, might_sleep(); + if (bh->b_bdev->bd_super) + ext4_check_bdev_write_error(bh->b_bdev->bd_super); + if (ext4_handle_valid(handle)) { err = jbd2_journal_get_write_access(handle, bh); if (err) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index dda967efcbc2c..c77b10257b36a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4765,6 +4765,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } #endif /* CONFIG_QUOTA */ + /* + * Save the original bdev mapping's wb_err value which could be + * used to detect the metadata async write error. + */ + spin_lock_init(&sbi->s_bdev_wb_lock); + if (!sb_rdonly(sb)) + errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err, + &sbi->s_bdev_wb_err); + sb->s_bdev->bd_super = sb; EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS; ext4_orphan_cleanup(sb, es); EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS; @@ -5654,6 +5663,14 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) goto restore_opts; } + /* + * Update the original bdev mapping's wb_err value + * which could be used to detect the metadata async + * write error. + */ + errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err, + &sbi->s_bdev_wb_err); + /* * Mounting a RDONLY partition read-write, so reread * and store the current valid flag. (It may have -- 2.25.1