From: Jan Schmidt <list.btrfs@jan-o-sch.net>
To: Kai Krakow <hurikhan77+btrfs@gmail.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: WARNING: at fs/btrfs/extent-tree.c:4754 followed by BUG: unable to handle kernel NULL pointer dereference at (null)
Date: Thu, 08 Dec 2011 17:03:55 +0100 [thread overview]
Message-ID: <4EE0DFEB.2000904@jan-o-sch.net> (raw)
In-Reply-To: <vhv4r8-hb5.ln1@hurikhan.ath.cx>
On 07.12.2011 21:40, Kai Krakow wrote:
> Scrubbing reports 1 uncorrectable error. I have this error since my system
> froze due to some xorg graphic driver instability (was trying out SNA
> acceleration for sandybridge).
>
> The problematic file seems to be in /usr/portage but scrubbing doesn't tell
> me the filename (I was under the impression 3.2.x adds a patch which should
> report filenames).
It should. Did you take a look at dmesg output after scrubbing? If it
doesn't contain a hint on the file or block, please paste what you get.
> Everytime I run "emerge" (it is a gentoo system) my
> screen goes black after a few seconds and I can only revert to using ssh.
>
> Problem is: As soon as this happens, some filesystem accesses block the
> process in disk state, it cannot be killed. This initiates some feedback
> loop: From now on any other process trying to access the FS freezes. I can
> only reisub now. It seems to be fine if data comes from cache instead from
> disk.
Please try to grab sysrq+w output in this state.
-Jan
next prev parent reply other threads:[~2011-12-08 16:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-07 20:40 WARNING: at fs/btrfs/extent-tree.c:4754 followed by BUG: unable to handle kernel NULL pointer dereference at (null) Kai Krakow
2011-12-08 16:03 ` Jan Schmidt [this message]
2011-12-09 13:34 ` Kai Krakow
2011-12-15 4:11 ` Kai Krakow
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