Re: [PATCH 4/4] block/nbd: nbd_co_reconnect_loop(): don't connect if drained

[Eric Blake]

On 9/3/20 2:03 PM, Vladimir Sementsov-Ogievskiy wrote:
> In a recent commit 12c75e20a269ac we've improved
> nbd_co_reconnect_loop() to not make drain wait for additional sleep.
> Similarly, we shouldn't try to connect, if previous sleep was
> interrupted by drain begin, otherwise drain_begin will have to wait for
> the whole connection attempt.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>   block/nbd.c | 3 +++
>   1 file changed, 3 insertions(+)

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

> diff --git a/block/nbd.c b/block/nbd.c
> index caae0e6d31..4548046cd7 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -661,6 +661,9 @@ static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState 
> *s)
>           } else {
>               qemu_co_sleep_ns_wakeable(QEMU_CLOCK_REALTIME, timeout,
>                                         &s->connection_co_sleep_ns_state);
> +            if (s->drained) {
> +                continue;
> +            }
>               if (timeout < max_timeout) {
>                   timeout *= 2;
>               }

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