lkml.org 
[lkml]   [2010]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: hunt for 2.6.37 dm-crypt+ext4 corruption? (was: Re: dm-crypt barrier support is effective)
On Sat, Dec 11, 2010 at 7:40 PM, Ted Ts'o <tytso@mit.edu> wrote:
> Yes, indeed. Is this in the virtualized environment or on real
> hardware at this point? And how many CPU's do you have configured in
> your virtualized environment, and how memory memory? Is having a
> certain number of CPU's critical for reproducing the problem? Is
> constricting the amount of memory important?

Originally, I observed the behavior on really real hardware.

Since then, I have been able to reproduce it in VirtualBox and
qemu-kvm, with openSUSE 11.3 and KUbuntu. All of the more recent tests
have been with qemu-kvm.

I have one CPU configured in the environment, 512MB of memory.
I have not done any memory-constriction tests whatsoever.

> It'll be a lot easier if I can reproduce it locally, which is why I'm
> asking all of these questions.

On Sat, Dec 11, 2010 at 8:34 PM, Ted Ts'o <tytso@mit.edu> wrote:
> One experiment --- can you try this with the file system mounted with
> data=writeback, and see if the problem reproduces in that journalling
> mode?

That test is running now, first with encryption. I will report if it
shows problems. If it does, I will wait until I have been able to see
that a few times, and move to a no-encryption test. Typically, I have
to run quite a few more iterations of that test before problems show
up (if they will at all).

> I want to rule out (if possible) journal_submit_inode_data_buffers()
> racing with mpage_da_submit_io().  I don't think that's the issue, but
> I'd prefer to do the experiment to make sure.  So if you can use a
> kernel and system configuration which triggers the problem, and then
> try changing the mount options to include data=writeback, and then
> rerun the test, and let me know if the problem still reproduces, I'd
> be really grateful.


--
Jon
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-12-12 04:19    [from the cache]
©2003-2011 Jasper Spaans