btrfs scrub can neither start nor cancel

btrfs scrub can neither start nor cancel

[Wolfgang Rohdewald]

I just tried this script:
http://marc.merlins.org/perso/btrfs/2014-03.html#Btrfs-Tips_-Btrfs-Scrub-and-Btrfs-Filesystem-Repair

but I did not pass the directory where the filesystem is mounted.

Next I called it correctly: btrfs-scrub /t4
I also tried btrfs scrub start / cancel directly, but 
I am not really sure what I did in which order.

Anyway now I can neither cancel nor start btrfs scrub. Rebooting did not help.
Running unmodified Linux 4.3

It seems like scrub stopped and did not clean up. Maybe because:
Dec  8 21:07:41 s5 kernel: [17833.840868] btrfs[23746]: segfault at ffffffffffffff98 ip 00000000004079e1 sp 00007fffafa27510 error 5 in btrfs[400000+53000]

How can I now clean this up?

root@s5:~# btrfs --version
Btrfs v3.12

root@s5:~# btrfs scrub status /t4
scrub status for 700900de-e35f-4264-8f5d-1b2b249a5c3a
        scrub started at Tue Dec  8 21:05:31 2015, running for 20 seconds
        total bytes scrubbed: 3.09GiB with 0 errors

root@s5:~# btrfs scrub cancel /t4
ERROR: scrub cancel failed on /t4: not running

root@s5:~# btrfs scrub start /t4
ERROR: scrub is already running.
To cancel use 'btrfs scrub cancel /t4'.
To see the status use 'btrfs scrub status [-d] /t4'.


-- 
Wolfgang

Re: btrfs scrub can neither start nor cancel

[Hugo Mills]

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On Tue, Dec 08, 2015 at 09:46:48PM +0100, Wolfgang Rohdewald wrote:
> I just tried this script:
> http://marc.merlins.org/perso/btrfs/2014-03.html#Btrfs-Tips_-Btrfs-Scrub-and-Btrfs-Filesystem-Repair
> 
> but I did not pass the directory where the filesystem is mounted.
> 
> Next I called it correctly: btrfs-scrub /t4
> I also tried btrfs scrub start / cancel directly, but 
> I am not really sure what I did in which order.
> 
> Anyway now I can neither cancel nor start btrfs scrub. Rebooting did not help.

   It might be that the userspace tools has got confused and left
behind a lock/pid/progress file in /var/lib/btrfs/

   Take a look in there and see if there's anything that you can
delete to good effect?

   Hugo.

> Running unmodified Linux 4.3
> 
> It seems like scrub stopped and did not clean up. Maybe because:
> Dec  8 21:07:41 s5 kernel: [17833.840868] btrfs[23746]: segfault at ffffffffffffff98 ip 00000000004079e1 sp 00007fffafa27510 error 5 in btrfs[400000+53000]
> 
> How can I now clean this up?
> 
> root@s5:~# btrfs --version
> Btrfs v3.12
> 
> root@s5:~# btrfs scrub status /t4
> scrub status for 700900de-e35f-4264-8f5d-1b2b249a5c3a
>         scrub started at Tue Dec  8 21:05:31 2015, running for 20 seconds
>         total bytes scrubbed: 3.09GiB with 0 errors
> 
> root@s5:~# btrfs scrub cancel /t4
> ERROR: scrub cancel failed on /t4: not running
> 
> root@s5:~# btrfs scrub start /t4
> ERROR: scrub is already running.
> To cancel use 'btrfs scrub cancel /t4'.
> To see the status use 'btrfs scrub status [-d] /t4'.
> 
> 

-- 
Hugo Mills             | Go not to the elves for counsel, for they will say
hugo@... carfax.org.uk | both no and yes.
http://carfax.org.uk/  |
PGP: E2AB1DE4          |

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Re: btrfs scrub can neither start nor cancel

[Wolfgang Rohdewald]

Am Dienstag, 8. Dezember 2015, 20:51:08 schrieb Hugo Mills:
> On Tue, Dec 08, 2015 at 09:46:48PM +0100, Wolfgang Rohdewald wrote:
> > Anyway now I can neither cancel nor start btrfs scrub. Rebooting did not help.
> 
>    It might be that the userspace tools has got confused and left
> behind a lock/pid/progress file in /var/lib/btrfs/
> 
>    Take a look in there and see if there's anything that you can
> delete to good effect?

root@s5:/var/lib/btrfs# ls -l
insgesamt 4
srwxr-xr-x 1 root root   0 Dez  8 21:05 scrub.progress.700900de-e35f-4264-8f5d-1b2b249a5c3a
-rw------- 1 root root 394 Dez  8 21:05 scrub.status.700900de-e35f-4264-8f5d-1b2b249a5c3a

that fixed it, thanks!

I would have expected that such temporary files are deleted at reboot, so
ẗo me this looks like a bug in user-space.


-- 
Wolfgang