From: Alexander Stein <alexander.stein@systec-electronic.com>
To: linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org
Subject: UBIFS is not remounted read-only from within do_emergency_remount
Date: Tue, 31 Jul 2012 13:24:19 +0200 [thread overview]
Message-ID: <16202485.ui8ZXcNIqe@ws-stein> (raw)
Hello,
upon testing do_emergency_remount from a power fail interrupt (using the
workqueue of course), we noticed UBIFS is not remounted read-only afterwards.
The current code in do_emergency_remount checks if the kernel actually needs
to remount a filesystem using the following code:
> if (sb->s_root && sb->s_bdev && (sb->s_flags & MS_BORN) &&
> !(sb->s_flags & MS_RDONLY)) {
> /*
> * What lock protects sb->s_flags??
> */
> do_remount_sb(sb, MS_RDONLY, NULL, 1);
> }
I'm not in the details of this part of the kernel, but I suspect that sb-
>s_bdev is NULL for UBIFS as it has no block device, but the character device
/dev/ubiX_Y instead. I have the information from a collegue that removing the
check for testing purposes for sb->s_bdev mounts UBIFS read-only.
Any comments/ideas how to remount UBIFS as read-only from
do_emergency_remount?
Best regards,
Alexander
next reply other threads:[~2012-07-31 11:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-31 11:24 Alexander Stein [this message]
2012-08-24 7:22 ` UBIFS is not remounted read-only from within do_emergency_remount Artem Bityutskiy
2012-08-27 7:16 ` Alexander Stein
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