btrfs-cache processes

btrfs-cache processes

[Adrian Ulrich]

Hi,

I've upgraded my system to 2.6.31-rc5 some days ago. Yesterday i've discovered that
this kernel produces some berserk btrfs-cache processes:

There are about 4 of them and they use ~95% sys-cputime.
About 20 seconds after they started 'freaking out' all writes to BTRFS will
block and umounting also doesn't work anymore. Reading the volume
still works (mostly) and there appers to be no disk activity (iostat/top
reports nothing unusual).

This isn't normal, isn't it? ;-)

Everything appears to work fine on Linux 2.6.31-rc3

Regards,
 Adrian

Re: btrfs-cache processes

[Yan Zheng]

2009/8/9 Adrian Ulrich <adrian@blinkenlights.ch>:
> Hi,
>
> I've upgraded my system to 2.6.31-rc5 some days ago. Yesterday i've discovered that
> this kernel produces some berserk btrfs-cache processes:
>
> There are about 4 of them and they use ~95% sys-cputime.
> About 20 seconds after they started 'freaking out' all writes to BTRFS will
> block and umounting also doesn't work anymore. Reading the volume
> still works (mostly) and there appers to be no disk activity (iostat/top
> reports nothing unusual).
>
> This isn't normal, isn't it? ;-)
>
> Everything appears to work fine on Linux 2.6.31-rc3
>

This has been fixed in the unstable tree. The fix will be in 2.6.31-rc6
soon.

Yan, Zheng

Re: btrfs-cache processes

[Adrian Ulrich]

Hi,

> This has been fixed in the unstable tree. The fix will be in 2.6.31-rc6
> soon.

Thanks and sorry for the noise.

I've upgraded to the latest version and can confirm that it
solves the btrfs-cache problem.

Regards,
 Adrian