Kernel 2.6.30.4 loop(..?) regression (& with/2.6.31-rc6)

[Justin Piszcz]

On Wed, 26 Aug 2009, Justin Piszcz wrote:

>
>
> On Wed, 26 Aug 2009, Christoph Hellwig wrote:
>
>> On Wed, Aug 26, 2009 at 05:19:11PM -0400, Justin Piszcz wrote:
>>> For the root filesystem, on / type xfs (rw,noatime)
>>> For larger partitions (per the cryptoloop doc) the partition itself is
>>> setup via cryptoloop and then XFS ontop of that.  Nothing special.
>> 
>> Just to make sure we have all data here - you see the problem only
>> with loop devices backed by XFS, only with loop devices backed by
>> raw partitions or with both?
> Both.
>
>> 
>>>> Any way to trgiger it with just loop but not crypto, etc.
>>> Unfortunately not that I am aware of..  Would trying the kernel with the
>>> patch removed and mounted with -o nobarrier help to show us anything, or?
>> 
>> Actually, yes - seeing what happens if you run plain 2.6.30 or 2.6.31-rc
>> without the backout patch, but with -o nobarrier would be very
>> interesting.
>> 
> Will give it a try with 2.6.31-rc6 and mount all loop devices (both those 
> backed by XFS and raw partitions) with -o nobarrier to see if the problem 
> recurs.  So far though with that patch up until this next test, there were no 
> problems.
>
> Justin.
>
>

Hi,

So far:

$ uptime
  07:20:04 up 1 day, 13:49,  1 user,  load average: 0.07, 0.02, 0.06

Let's give it another 48-72 hours with -o nobarrier, so far, it has not 
recurred.

It still may happen; however, moving forward I was wondering..

If both '-o nobarrier' and the patch solves the issue, what is the next 
action that should be taken?  Update the documentation to always use
-o nobarrier for cryptoloop? Or get the patch reverted in mainline?

Justin.