Re: [PATCH v2 00/10] mirror: cancel nbd reconnect

[Eric Blake]

On 2/5/21 10:37 AM, Vladimir Sementsov-Ogievskiy wrote:
> Hi all!
> 
> The problem
> 
> Assume we have mirror job with nbd target node with enabled reconnect.
> Connection failed. So, all current requests to nbd node are waiting for
> nbd driver to reconnect. And they will wait for reconnect-delay time
> specified in nbd blockdev options. This timeout may be long enough, for
> example, we in Virtuozzo use 300 seconds by default.
> 
> So, if at this moment user tries to cancel the job, job will wait for
> its in-flight requests to finish up to 300 seconds. From the user point
> of view, cancelling the job takes a long time. Bad.
> 
> Solution
> 
> Let's just cancel "waiting for reconnect in in-flight request coroutines"
> on mirror (and backup) cancel. Welcome the series below.
> 
> v2: wording, rebase on master, add Eric's r-bs, update test-output in
>     last commit

Thanks; I'm queuing this through my NBD tree.

> 
> Vladimir Sementsov-Ogievskiy (10):
>   block: add new BlockDriver handler: bdrv_cancel_in_flight
>   block/nbd: implement .bdrv_cancel_in_flight
>   block/raw-format: implement .bdrv_cancel_in_flight handler
>   job: add .cancel handler for the driver
>   block/mirror: implement .cancel job handler
>   iotests/264: move to python unittest
>   iotests.py: qemu_nbd_popen: remove pid file after use
>   iotests/264: add mirror-cancel test-case
>   block/backup: implement .cancel job handler
>   iotests/264: add backup-cancel test-case
> 
>  include/block/block.h         |   3 +
>  include/block/block_int.h     |   9 +++
>  include/qemu/job.h            |   5 ++
>  block/backup.c                |  10 +++
>  block/io.c                    |  11 +++
>  block/mirror.c                |   9 +++
>  block/nbd.c                   |  15 ++++
>  block/raw-format.c            |   6 ++
>  job.c                         |   3 +
>  tests/qemu-iotests/264        | 140 ++++++++++++++++++++++------------
>  tests/qemu-iotests/264.out    |  20 ++---
>  tests/qemu-iotests/iotests.py |   6 +-
>  12 files changed, 172 insertions(+), 65 deletions(-)
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org