Re: [Qemu-devel] ahci-test failures with 'Failed to get "write" lock'

[John Snow]

On 06/15/2017 11:28 AM, Dr. David Alan Gilbert wrote:
> Hi,
>   Peter noticed that there were some hangs in the ahci-test;
> I can reproduce them on my laptop as long as the laptop has
> some other load on it (a few md5sum /dev/zero's help).
> 
> /x86_64/ahci/flush/migrate: qemu-system-x86_64: Failed to get "write" lock
> Is another process using the image?
> OK
> /x86_64/ahci/migrate/sanity: qemu-system-x86_64: Failed to get "write" lock
> Is another process using the image?
> 
> and that hangs in sanity.
> 
> That seems to be the common case, I've also had one:
> 
> /x86_64/ahci/migrate/ncq/halted: qemu-system-x86_64: Failed to get "write" 
> lock
> Is another process using the image?
> qemu-system-x86_64: /home/dgilbert/git/qemu/block/io.c:1352: 
> bdrv_aligned_pwritev: Assertion `child->perm & BLK_PERM_WRITE' failed.
> 
> 
> Neither of these always fail.
> 
> Dave
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK
> 

Haven't observed myself and I run the tests pretty frequently. I'll keep
an eye out. I see many similar problems in iotests for other areas, too.

AHCI tests *should* never overlap and *should* never be using images in
an unsafe way, and do a full set-up and tear-down for each individual
unit test.

Of course, maybe the migrate code isn't behaving quite so nicely with
loopback migrations...?