[dm-devel] Dm-integrity freeze

[Mike Snitzer]

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")

Mike