From: Chris Mason <chris.mason@oracle.com>
To: Philip Love <Love_Phil@emc.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: btrfs bug while defragmenting
Date: Tue, 9 Mar 2010 14:25:16 -0500 [thread overview]
Message-ID: <20100309192516.GQ15485@think> (raw)
In-Reply-To: <D09C8589-EA52-4778-8B29-1B06B27292D0@emc.com>
On Tue, Mar 09, 2010 at 10:45:13AM -0800, Philip Love wrote:
> I had some 10gb files that I was using for random write testing (with cow enabled). I remount the fs with nodatacow, then ran btrfsctl to defragement the file. A BUG message appeared in the messages file. After a reboot btrfsck gave no errors.
>
> Please let me know what extra information you need.
> Thanks
> Phil
>
> Mar 9 10:12:25 sentryA kernel: [66771.230266] BUG: Bad page state in process btrfsctl pfn:201575
> Mar 9 10:12:25 sentryA kernel: [66771.230270] page:ffffea000704b198 flags:0040000000000000 count:-1608652401 mapcount:0 mapping:ffff88002e84b000 index:ffffc90002633d40
Well, I don't think that count is quite right. But I also don't see
anything in the ioctl that could cause it. How easily can you reproduce
this?
I do see that the ioctl should be triple checking the page is part of
the mapping after doing a readpage on it, but it should only get dropped
in the face of truncate. Is this file actively in use at the time that
you're running the ioctl?
-chris
next prev parent reply other threads:[~2010-03-09 19:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-09 18:45 btrfs bug while defragmenting Philip Love
2010-03-09 19:25 ` Chris Mason [this message]
2010-03-09 20:06 ` Philip Love
2010-03-09 20:25 ` Philip Love
2010-03-10 20:47 ` Philip Love
2010-03-10 20:58 ` Chris Mason
2010-03-09 20:21 ` Philip Love
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