Bug#782362: Regression: 3.16.7-ckt9-1: mouning rootpartition cause a deadlock at mount time

On Sat, Apr 11, 2015 at 3:55 AM, Ben Hutchings <ben@decadent.org.uk> wrote:

Control: tag -1 patch moreinfo

On Sat, 2015-04-11 at 01:30 +0300, Lebedev Roman wrote:
> Package: src:linux
> Version: 3.16.7-ckt9-1
> Severity: important
>
> Dear Maintainer,
>
> kernel version 3.16.7-ckt9-1 is broken, a deadlock at mount time happens in BTRFS.
> Previous kernel version (which i'm using right now to report this) - 3.16.7-ckt7-1 is fine.
>
> This is a known upstream issue:
> >From https://btrfs.wiki.kernel.org/index.php/Gotchas
> * Stable kernel version 3.19.1+ can cause a deadlock at mount time
> * * workaround: boot with older kernel, or run btrfs-zero-log to clear the log (beware of the consequences)
> * * fix: scheduled for 3.19.4, or apply 9c4f61f01d269815bb7c37.
> * * also affected: 3.14.35+, 3.18.9+
>
> I consider this issue to be of "grave" severity, but only for those using BTRFS.
>
> Please fix this.
> (either backport that patch or revert to previous kernel (3.16.7-ckt7-1) or drop the patches that cause this)
>
> NOTE: i have already downgraded to ckt7 to report this, so all the lines below are for ckt7, not ckt9.

Please test a kernel package built with this patch added:
https://people.debian.org/~benh/packages/linux-image-3.16.0-4-amd64_3.16.7-ckt9-2~bwh.1_amd64.deb

I have tested provided kernel, and i can confirm that the issue is fixed there.

It boots fine, no deadlock.

To test, i have got my FS into the state when it hanged 3.16.7-ckt9-1 on boot, which i got installed,

and then, without doing anything to the FS, i tried booting 3.16.7-ckt9-2~bwh-1, and it succeeded.

The sha256sum of that file is:
f6f194e841341a8e837fac9d53c0a82b2b7e77cb31807784167869a1c97058b7 linux-image-3.16.0-4-amd64_3.16.7-ckt9-2~bwh.1_amd64.deb

Ben.

--
Ben Hutchings
compatible: Gracefully accepts erroneous data from any source

Roman.