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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 6F1CBC43441 for ; Sun, 11 Nov 2018 20:07:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38B912080D for ; Sun, 11 Nov 2018 20:07:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38B912080D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731456AbeKLF4q (ORCPT ); Mon, 12 Nov 2018 00:56:46 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52102 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727208AbeKLF4q (ORCPT ); Mon, 12 Nov 2018 00:56:46 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvtB-0000tu-RD; Sun, 11 Nov 2018 19:59:21 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsO-0001Pi-PJ; Sun, 11 Nov 2018 19:58:32 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jan Kara" , "Theodore Ts'o" , "Amir Goldstein" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 046/366] ext4: do not update s_last_mounted of a frozen fs In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein commit db6516a5e7ddb6dc72d167b920f2f272596ea22d upstream. If fs is frozen after mount and before the first file open, the update of s_last_mounted bypasses freeze protection and prints out a WARNING splat: $ mount /vdf $ fsfreeze -f /vdf $ cat /vdf/foo [ 31.578555] WARNING: CPU: 1 PID: 1415 at fs/ext4/ext4_jbd2.c:53 ext4_journal_check_start+0x48/0x82 [ 31.614016] Call Trace: [ 31.614997] __ext4_journal_start_sb+0xe4/0x1a4 [ 31.616771] ? ext4_file_open+0xb6/0x189 [ 31.618094] ext4_file_open+0xb6/0x189 If fs is frozen, skip s_last_mounted update. [backport hint: to apply to stable tree, need to apply also patches vfs: add the sb_start_intwrite_trylock() helper ext4: factor out helper ext4_sample_last_mounted()] Fixes: bc0b0d6d69ee ("ext4: update the s_last_mounted field in the superblock") Signed-off-by: Amir Goldstein Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- fs/ext4/file.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -220,7 +220,7 @@ static int ext4_sample_last_mounted(stru if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED)) return 0; - if (sb->s_flags & MS_RDONLY) + if (sb->s_flags & MS_RDONLY || !sb_start_intwrite_trylock(sb)) return 0; sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; @@ -234,21 +234,25 @@ static int ext4_sample_last_mounted(stru path.mnt = mnt; path.dentry = mnt->mnt_root; cp = d_path(&path, buf, sizeof(buf)); + err = 0; if (IS_ERR(cp)) - return 0; + goto out; handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); + err = PTR_ERR(handle); if (IS_ERR(handle)) - return PTR_ERR(handle); + goto out; BUFFER_TRACE(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) - goto out; + goto out_journal; strlcpy(sbi->s_es->s_last_mounted, cp, sizeof(sbi->s_es->s_last_mounted)); ext4_handle_dirty_super(handle, sb); -out: +out_journal: ext4_journal_stop(handle); +out: + sb_end_intwrite(sb); return err; }