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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 65751C10F05 for ; Sat, 30 Mar 2019 00:53:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35461218EA for ; Sat, 30 Mar 2019 00:53:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553907193; bh=NH009Ir/2Wr7mR+8dEzF0LGR9Yow18sYrmheC3DGcy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DHtXwikCwVYI9OxSIvum/cxwlcbULpAc1jtgm2bWfDGM8QnYHHT55KSbR3qPNgAAN YYcEDlBlnStaP+OQocDi3pFOxyr0i6C3Ml2nGq+TT6htG3/EsH/UaSisDi0tMSUnUy fcCkR3qymzLjZ/2TjmGTofgiQZGtt664h9eZJJYs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731214AbfC3AxM (ORCPT ); Fri, 29 Mar 2019 20:53:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:60032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731202AbfC3AxL (ORCPT ); Fri, 29 Mar 2019 20:53:11 -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 5BDA9218FE; Sat, 30 Mar 2019 00:53:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553907191; bh=NH009Ir/2Wr7mR+8dEzF0LGR9Yow18sYrmheC3DGcy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I8V8/DAe2IbS+0SK00KZCPKeEYJyoOt8SkN5qVZPdP/oZhsrE8jMXvDak07MFq+dr aUHMTalVkkD3/QNaWerZ6YWAz1sQRzpHjcHVQiWgMOYfcz4DsVOvgge4/qurBLgOHh 89RUvLYMgiEXiBOjSZP+dcn30L8UJ5PCF4Sj+6eo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jan Kara , Theodore Ts'o , Sasha Levin , linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 06/52] ext4: avoid panic during forced reboot Date: Fri, 29 Mar 2019 20:52:13 -0400 Message-Id: <20190330005301.26868-6-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190330005301.26868-1-sashal@kernel.org> References: <20190330005301.26868-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Jan Kara [ Upstream commit 1dc1097ff60e4105216da7cd0aa99032b039a994 ] When admin calls "reboot -f" - i.e., does a hard system reboot by directly calling reboot(2) - ext4 filesystem mounted with errors=panic can panic the system. This happens because the underlying device gets disabled without unmounting the filesystem and thus some syscall running in parallel to reboot(2) can result in the filesystem getting IO errors. This is somewhat surprising to the users so try improve the behavior by switching to errors=remount-ro behavior when the system is running reboot(2). Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/super.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index a1cf7d68b4f0..abba7ece78e9 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -430,6 +430,12 @@ static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn) spin_unlock(&sbi->s_md_lock); } +static bool system_going_down(void) +{ + return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF + || system_state == SYSTEM_RESTART; +} + /* Deal with the reporting of failure conditions on a filesystem such as * inconsistencies detected or read IO failures. * @@ -460,7 +466,12 @@ static void ext4_handle_error(struct super_block *sb) if (journal) jbd2_journal_abort(journal, -EIO); } - if (test_opt(sb, ERRORS_RO)) { + /* + * We force ERRORS_RO behavior when system is rebooting. Otherwise we + * could panic during 'reboot -f' as the underlying device got already + * disabled. + */ + if (test_opt(sb, ERRORS_RO) || system_going_down()) { ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); /* * Make sure updated value of ->s_mount_flags will be visible @@ -468,8 +479,7 @@ static void ext4_handle_error(struct super_block *sb) */ smp_wmb(); sb->s_flags |= SB_RDONLY; - } - if (test_opt(sb, ERRORS_PANIC)) { + } else if (test_opt(sb, ERRORS_PANIC)) { if (EXT4_SB(sb)->s_journal && !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR)) return; -- 2.19.1