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From: David Arendt <admin@prnet.org>
To: john terragon <jterragon@gmail.com>
Cc: Rich Freeman <r-btrfs@thefreemanclan.net>,
	Chris Mason <clm@fb.com>,
	Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: btrfs random filesystem corruption in kernel 3.17
Date: Mon, 13 Oct 2014 23:22:19 +0200	[thread overview]
Message-ID: <543C428B.1020503@prnet.org> (raw)
In-Reply-To: <CANg_oxytS04xrVLfWzgz7sJZBArJ-HM8nGADF+ujjRy8heYjqQ@mail.gmail.com>

As these to machines are running as server for different purposes (yes,
I know that btrfs is unstable and any corruption or data loss is at my
own risk therefore I have good backups), I want to reboot them not more
then necessary.

However I tried to bring my reboot times in relation with corruptions:

machine 1:

d????????? ? ?      ?         ?            ? root.20141009.000503.backup

reboot   system boot  3.17.0           Thu Oct  9 23:20   still running
reboot   system boot  3.17.0           Tue Oct  7 21:25 - 23:18 (2+01:53)
reboot   system boot  3.17.0           Mon Oct  6 22:47 - 23:18 (3+00:31)

For this machine, corruption seems to have occurred for a snapshot
created after a reboot.


machine 2:

d????????? ? ?    ?      ?            ? root.20141006.003239.backup
d????????? ? ?    ?      ?            ? root.20141007.001616.backup
d????????? ? ?    ?      ?            ? root.20141008.000501.backup
d????????? ? ?    ?      ?            ? root.20141009.052436.backup

reboot   system boot  3.17.0           Thu Oct  9 21:31   still running
reboot   system boot  3.17.0           Tue Oct  7 21:27 - 21:30 (2+00:03)
reboot   system boot  3.17.0           Tue Oct  7 17:51 - 21:26  (03:34)
reboot   system boot  3.17.0           Sun Oct  5 23:50 - 17:50 (1+17:59)
reboot   system boot  3.17.0           Sun Oct  5 23:47 - 23:49  (00:01)

During the next days, I will setup a virtual machine to do more tests.

On 10/13/2014 10:48 PM, john terragon wrote:
> I think I just found a consistent simple way to trigger the problem
> (at least on my system). And, as I guessed before, it seems to be
> related just to readonly snapshots:
>
> 1) I create a readonly snapshot
> 2) I do some changes on the source subvolume for the snapshot (I'm not
> sure changes are strictly needed)
> 3) reboot (or probably just unmount and remount. I reboot because the
> fs I've problems with contains my root subvolume)
>
> After the rebooting (or the remount) I consistently have the corruption
> with the usual multitude of these in dmesg
> "parent transid verify failed on 902316032 wanted 2484 found 4101"
> and the characteristic ls -la output
>
> drwxr-xr-x 1 root root  250 Oct 10 15:37 root
> d????????? ? ?    ?       ?            ? root-b2
> drwxr-xr-x 1 root root  250 Oct 10 15:37 root-b3
> d????????? ? ?    ?       ?            ? root-backup
>
> root-backup and root-b2 are both readonly whereas root-b3 is rw (and
> it didn't get corrupted).
>
> David, maybe you can try the same steps on one of your machines?
>
> John


      parent reply	other threads:[~2014-10-13 21:24 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <DC336054-F307-4A86-AD6D-204E700DE9AA@prnet.org>
2014-10-07 13:19 ` btrfs send and kernel 3.17 Chris Mason
2014-10-07 20:45   ` David Arendt
2014-10-07 20:46     ` Chris Mason
2014-10-12 11:11       ` David Arendt
2014-10-12 15:24         ` john terragon
2014-10-12 21:35           ` David Arendt
2014-10-13  4:11             ` David Arendt
2014-10-13 12:40               ` john terragon
2014-10-13 15:40                 ` David Arendt
2014-10-13 17:22         ` Rich Freeman
2014-10-13 20:27           ` btrfs random filesystem corruption in " David Arendt
2014-10-13 20:42             ` Rich Freeman
2014-10-13 22:36               ` Duncan
2014-10-14 11:17                 ` admin
2014-10-14 21:35                   ` Duncan
2014-10-14 22:03                     ` Robert White
2014-10-14 22:55                       ` Duncan
2014-10-14 17:00                 ` David Arendt
2014-10-13 20:48             ` john terragon
2014-10-13 20:55               ` Rich Freeman
2014-10-13 20:57                 ` Rich Freeman
2014-10-13 21:22                 ` john terragon
2014-10-13 21:25                   ` David Arendt
2014-10-13 21:49                     ` Duncan
2014-10-13 23:18                   ` Rich Freeman
2014-10-14  1:30                     ` john terragon
2014-10-13 21:22               ` David Arendt [this message]

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