From: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
To: Andreas Philipp <philipp.andreas@gmail.com>
Cc: btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: No SysRq remount because sb->s_bdev is NULL
Date: Sat, 28 Jul 2012 16:50:38 +0200 [thread overview]
Message-ID: <2108513.KBpvBiH5fV@nezir> (raw)
In-Reply-To: <5013ED4A.3070609@gmail.com>
On Saturday, July 28, 2012 15:46:50 Andreas Philipp wrote:
> On 28.07.2012 15:41, Florian Albrechtskirchinger wrote:
> > During a SysRq emergency remount Btrfs mounts are not remounted. I tracked
> > the issue down to this line in do_emergency_remount() in fs/super.c:
> > if (sb->s_root && sb->s_bdev && (sb->s_flags & MS_BORN) &&
> > !(sb->s_flags & MS_RDONLY))
> > s_bdev is NULL for Btrfs super blocks and subsequently do_remount_sb() is
> > never called. I couldn't think of a solution, besides resorting to an ugly
> > strcmp(sb->s_type->name, "btrfs"), without adding a field to struct
> > super_block or similar changes.
> > Thoughts?
>
> Just a first thought. Is there a possibility to write a dummy value into
> sb->s_bdev for btrfs super blocks. Thus it will not be NULL and
> everything in do_emergency_remount() in fs/super.c will work as wanted.
Then other code paths testing sb->s_bdev for NULL and assuming a non-NULL sb-
>s_bdev is a valid block device would fail.
Flo
next prev parent reply other threads:[~2012-07-28 14:50 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-28 13:41 No SysRq remount because sb->s_bdev is NULL Florian Albrechtskirchinger
2012-07-28 13:46 ` Andreas Philipp
2012-07-28 14:50 ` Florian Albrechtskirchinger [this message]
2012-07-28 16:30 ` Andreas Philipp
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