From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= Subject: [PATCH 2/2] ext4: don't update sb journal_devnum when RO dev Date: Sun, 26 Sep 2010 15:38:29 -0700 Message-ID: <1285540709-16217-2-git-send-email-zenczykowski@gmail.com> References: <1285540709-16217-1-git-send-email-zenczykowski@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= , Theodore Ts'o To: linux-ext4@vger.kernel.org Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:49938 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757876Ab0IZWky (ORCPT ); Sun, 26 Sep 2010 18:40:54 -0400 Received: by qyk36 with SMTP id 36so4178761qyk.19 for ; Sun, 26 Sep 2010 15:40:54 -0700 (PDT) In-Reply-To: <1285540709-16217-1-git-send-email-zenczykowski@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: An ext4 filesystem on a read-only device, with an external journal which is at a different device number then recorded in the superblock will fail to honor the read-only setting of the device and trigger a superblock update (write). =46or example: - ext4 on a software raid which is in read-only mode - external journal on a read-write device which has changed device nu= m - attempt to mount with -o journal_dev=3D - hits BUG_ON(mddev->ro =3D 1) in md.c Cc: Theodore Ts'o Signed-off-by: Maciej =C5=BBenczykowski --- fs/ext4/super.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 2614774..48388c7 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3470,7 +3470,7 @@ static int ext4_load_journal(struct super_block *= sb, EXT4_SB(sb)->s_journal =3D journal; ext4_clear_journal_err(sb, es); =20 - if (journal_devnum && + if (!really_read_only && journal_devnum && journal_devnum !=3D le32_to_cpu(es->s_journal_dev)) { es->s_journal_dev =3D cpu_to_le32(journal_devnum); =20 --=20 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html