On 6/18/19 6:43 AM, Vladimir Sementsov-Ogievskiy wrote:
> To implement reconnect we need several states for the client:
> CONNECTED, QUIT and two different CONNECTING states. CONNECTING states
> will be added in the following patches. This patch implements CONNECTED
> and QUIT.
> 
> QUIT means, that we should close the connection and fail all current
> and further requests (like old quit = true).
> 
> CONNECTED means that connection is ok, we can send requests (like old
> quit = false).
> 
> For receiving loop we use a comparison of the current state with QUIT,
> because reconnect will be in the same loop, so it should be looping
> until the end.
> 
> Opposite, for requests we use a comparison of the current state with
> CONNECTED, as we don't want to send requests in future CONNECTING
> states.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  block/nbd.c | 58 ++++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 37 insertions(+), 21 deletions(-)

> @@ -556,7 +572,7 @@ static coroutine_fn int nbd_co_do_receive_one_chunk(
>      s->requests[i].receiving = true;
>      qemu_coroutine_yield();
>      s->requests[i].receiving = false;
> -    if (s->quit) {
> +    if (s->state != NBD_CLIENT_CONNECTED) {
>          error_setg(errp, "Connection closed");
>          return -EIO;
>      }
> @@ -640,7 +656,7 @@ static coroutine_fn int nbd_co_receive_one_chunk(
>                                            request_ret, qiov, payload, errp);
>  
>      if (ret < 0) {
> -        s->quit = true;
> +        nbd_channel_error(s, ret);

Minor merge conflict with changes in the meantime; easy enough to sort out.

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