Re: [PATCH 01/11] block: add new BlockDriver handler: bdrv_cancel_in_flight

[Eric Blake <eblake@redhat.com>]

On 11/18/20 12:04 PM, Vladimir Sementsov-Ogievskiy wrote:
> It will be used to stop retrying NBD requests on mirror cancel.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  include/block/block.h     |  3 +++
>  include/block/block_int.h |  9 +++++++++
>  block/io.c                | 11 +++++++++++
>  3 files changed, 23 insertions(+)
> 

How does this relate to the recent addition of the QMP yank command?


> +++ b/include/block/block_int.h
> @@ -344,6 +344,15 @@ struct BlockDriver {
>          bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
>          int64_t *map, BlockDriverState **file);
>  
> +    /*
> +     * This informs the driver that we are not more interested in in-flight

that we are no longer interested in the result of in-flight requests, so

> +     * requests results, so don't waste the time if possible.
> +     *
> +     * The example usage is to not wait for nbd target nodedreconnect timeout on
> +     * job-cancel.

One example usage is to avoid waiting for an nbd target node reconnect
timeout during job-cancel.

Reviewed-by: Eric Blake <eblake@redhat.com>

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