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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 BF1A0C433DF for ; Tue, 26 May 2020 14:21:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A48D520663 for ; Tue, 26 May 2020 14:21:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728138AbgEZOVy (ORCPT ); Tue, 26 May 2020 10:21:54 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:5338 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726811AbgEZOVy (ORCPT ); Tue, 26 May 2020 10:21:54 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 44237631E2BB5AC2FA54; Tue, 26 May 2020 22:21:42 +0800 (CST) Received: from huawei.com (10.175.124.28) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.487.0; Tue, 26 May 2020 22:21:31 +0800 From: "zhangyi (F)" To: CC: , , , , Subject: [PATCH] ext4, jbd2: switch to use completion variable instead of JBD2_REC_ERR Date: Tue, 26 May 2020 22:20:39 +0800 Message-ID: <20200526142039.32643-1-yi.zhang@huawei.com> X-Mailer: git-send-email 2.21.3 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org In the ext4 filesystem with errors=panic, if one process is recording errno in the superblock when invoking jbd2_journal_abort() due to some error cases, it could be raced by another __ext4_abort() which is setting the SB_RDONLY flag but missing panic because errno has not been recorded. jbd2_journal_abort() journal->j_flags |= JBD2_ABORT; jbd2_journal_update_sb_errno() | __ext4_abort() | sb->s_flags |= SB_RDONLY; | if (!JBD2_REC_ERR) | return; journal->j_flags |= JBD2_REC_ERR; Finally, it will no longer trigger panic because the filesystem has already been set read-only. Fix this by remove JBD2_REC_ERR and switch to use completion variable instead. Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock") Signed-off-by: zhangyi (F) --- fs/ext4/super.c | 25 +++++++++++++------------ fs/jbd2/journal.c | 6 ++---- include/linux/jbd2.h | 6 +++++- 3 files changed, 20 insertions(+), 17 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index bf5fcb477f66..987a0bd5b78a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -495,6 +495,8 @@ static bool system_going_down(void) static void ext4_handle_error(struct super_block *sb) { + struct ext4_sb_info *sbi = EXT4_SB(sb); + if (test_opt(sb, WARN_ON_ERROR)) WARN_ON_ONCE(1); @@ -502,9 +504,9 @@ static void ext4_handle_error(struct super_block *sb) return; if (!test_opt(sb, ERRORS_CONT)) { - journal_t *journal = EXT4_SB(sb)->s_journal; + journal_t *journal = sbi->s_journal; - EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED; + sbi->s_mount_flags |= EXT4_MF_FS_ABORTED; if (journal) jbd2_journal_abort(journal, -EIO); } @@ -522,9 +524,8 @@ static void ext4_handle_error(struct super_block *sb) smp_wmb(); sb->s_flags |= SB_RDONLY; } else if (test_opt(sb, ERRORS_PANIC)) { - if (EXT4_SB(sb)->s_journal && - !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR)) - return; + if (sbi->s_journal && is_journal_aborted(sbi->s_journal)) + wait_for_completion(&sbi->s_journal->j_record_errno); panic("EXT4-fs (device %s): panic forced after error\n", sb->s_id); } @@ -710,10 +711,11 @@ void __ext4_std_error(struct super_block *sb, const char *function, void __ext4_abort(struct super_block *sb, const char *function, unsigned int line, int error, const char *fmt, ...) { + struct ext4_sb_info *sbi = EXT4_SB(sb); struct va_format vaf; va_list args; - if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) + if (unlikely(ext4_forced_shutdown(sbi))) return; save_error_info(sb, error, 0, 0, function, line); @@ -726,20 +728,19 @@ void __ext4_abort(struct super_block *sb, const char *function, if (sb_rdonly(sb) == 0) { ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); - EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED; + sbi->s_mount_flags |= EXT4_MF_FS_ABORTED; /* * Make sure updated value of ->s_mount_flags will be visible * before ->s_flags update */ smp_wmb(); sb->s_flags |= SB_RDONLY; - if (EXT4_SB(sb)->s_journal) - jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO); + if (sbi->s_journal) + jbd2_journal_abort(sbi->s_journal, -EIO); } if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) { - if (EXT4_SB(sb)->s_journal && - !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR)) - return; + if (sbi->s_journal && is_journal_aborted(sbi->s_journal)) + wait_for_completion(&sbi->s_journal->j_record_errno); panic("EXT4-fs panic from previous error\n"); } } diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index a49d0e670ddf..b8acdb2f7ac7 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1140,6 +1140,7 @@ static journal_t *journal_init_common(struct block_device *bdev, init_waitqueue_head(&journal->j_wait_commit); init_waitqueue_head(&journal->j_wait_updates); init_waitqueue_head(&journal->j_wait_reserved); + init_completion(&journal->j_record_errno); mutex_init(&journal->j_barrier); mutex_init(&journal->j_checkpoint_mutex); spin_lock_init(&journal->j_revoke_lock); @@ -2188,10 +2189,7 @@ void jbd2_journal_abort(journal_t *journal, int errno) * layer could realise that a filesystem check is needed. */ jbd2_journal_update_sb_errno(journal); - - write_lock(&journal->j_state_lock); - journal->j_flags |= JBD2_REC_ERR; - write_unlock(&journal->j_state_lock); + complete_all(&journal->j_record_errno); } /** diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index f613d8529863..0f623b0c347f 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -765,6 +765,11 @@ struct journal_s */ int j_errno; + /** + * @j_record_errno: complete to record errno in the journal superblock + */ + struct completion j_record_errno; + /** * @j_sb_buffer: The first part of the superblock buffer. */ @@ -1247,7 +1252,6 @@ JBD2_FEATURE_INCOMPAT_FUNCS(csum3, CSUM_V3) #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file * data write error in ordered * mode */ -#define JBD2_REC_ERR 0x080 /* The errno in the sb has been recorded */ /* * Function declarations for the journaling transaction and buffer -- 2.21.3