[dm-devel] Dm-integrity freeze

[Hans van Kranenburg]

On 5/22/19 12:07 AM, Mike Snitzer wrote:
> On Tue, May 21 2019 at  4:33pm -0400,
> Hans van Kranenburg <hans at knorrie.org> wrote:
> 
>> Hi,
>>
>> On 5/21/19 10:43 AM, Hans van Kranenburg wrote:
>>> Hi,
>>>
>>> I'm seeing the same lockup, also 4.19. This is mdadm RAID10 on top of 4x
>>> a partition with only dm-integrity.
>>>
>>> It just happened out of the blue, no heavy load or anything. All IO to
>>> it is frozen now.
>>>
>>> [...]
>>
>> There it is again... dmesg dump below. All cpus on 100% iowait.
>>
>> It's triggered after a few minutes by running some Windows 2019 server
>> install (ugh, don't ask) in a Xen HVM domU, which writes into a raw
>> sparse file on a btrfs filesystem on LVM on mdadm RAID10 on 4x
>> dm-integrity (wheeee!!)...
>>
>> This morning it was triggered a few minutes after starting an old
>> windows 2008 server image that I copied to this machine.
>>
>> When running only other Linux vms, and when copying data onto
>> filesystems that live in LVM logical volumes I haven't seen this problem
>> yet, at all, in the last few weeks that this machine is running.
>>
>> I noticed there's a "dm integrity: fix deadlock with overlapping I/O"
>> fix in a later 4.19. Is there any chance this is related? I have no
>> idea, but any hints or suggestions about what to try would be appreciated.
> 
> Yes, all your hung tasks are hung in wait_and_add_new_range().
> 
> Please use that later 4.19 or apply commit 4ed319c6ac08 ("dm integrity:
> fix deadlock with overlapping I/O")

Oh, silly me, that one is in 4.19.35 and I already have 4.9.37 based on
Debian in my repo, just rebooted the machine into it. Let's see what
happens today.

Thanks for confirming, sorry for the noise.

Hans