Re: [Qemu-devel] [PATCH 0/2] vl: Drain before (block) job cancel when quitting

[Max Reitz <mreitz@redhat.com>]

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On 13.06.19 00:08, Max Reitz wrote:
> Quitting qemu should lead to qemu exiting pretty much immediately.  That
> means if you have a block job running on a throttled block node, the
> node should ignore its throttling and the job should be cancelled
> immediately.
> 
> Unfortunately, that is not what happens.  Currently, the node will be
> drained (with a bdrv_drain_all()), and then again unquiesced (because
> bdrv_drain_all() ends).  Then, the block job is cancelled; but at this
> point, the node is no longer drained, so it will block, as it befits a
> throttling node.
> 
> To fix this issue, we have to keep all nodes drained while we cancel all
> block jobs when quitting qemu.  This will make the throttle node ignore
> its throttling and thus let the block job cancel immediately.

I forgot to mention: This series depends on “block: Keep track of parent
quiescing”, specifically patch 3 (“iotests: Add @has_quit to
vm.shutdown()”).

Based-on: <20190605161118.14544-1-mreitz@redhat.com>

Max

> Max Reitz (2):
>   vl: Drain before (block) job cancel when quitting
>   iotests: Test quitting with job on throttled node
> 
>  vl.c                       | 11 ++++++++
>  tests/qemu-iotests/218     | 55 ++++++++++++++++++++++++++++++++++++--
>  tests/qemu-iotests/218.out |  4 +++
>  3 files changed, 68 insertions(+), 2 deletions(-)
> 



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