Don't rely on connection being totally broken in case of -EIO. More
safe and correct just shutdown the channel anyway, as we change the
state and going to reconnect.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/nbd.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index f6ff1c4fb4..d88f4b954c 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -129,15 +129,16 @@ static bool nbd_client_connected(BDRVNBDState *s)
 
 static void nbd_channel_error(BDRVNBDState *s, int ret)
 {
+    if (nbd_client_connected(s)) {
+        qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+    }
+
     if (ret == -EIO) {
         if (nbd_client_connected(s)) {
             s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT :
                                             NBD_CLIENT_CONNECTING_NOWAIT;
         }
     } else {
-        if (nbd_client_connected(s)) {
-            qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
-        }
         s->state = NBD_CLIENT_QUIT;
     }
 }
-- 
2.29.2

On Wed, Jul 14, 2021 at 07:59:12PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> Don't rely on connection being totally broken in case of -EIO. More
> safe and correct just shutdown the channel anyway, as we change the
> state and going to reconnect.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  block/nbd.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

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

> 
> diff --git a/block/nbd.c b/block/nbd.c
> index f6ff1c4fb4..d88f4b954c 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -129,15 +129,16 @@ static bool nbd_client_connected(BDRVNBDState *s)
>  
>  static void nbd_channel_error(BDRVNBDState *s, int ret)
>  {
> +    if (nbd_client_connected(s)) {
> +        qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
> +    }
> +
>      if (ret == -EIO) {
>          if (nbd_client_connected(s)) {
>              s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT :
>                                              NBD_CLIENT_CONNECTING_NOWAIT;
>          }
>      } else {
> -        if (nbd_client_connected(s)) {
> -            qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
> -        }
>          s->state = NBD_CLIENT_QUIT;
>      }
>  }
> -- 
> 2.29.2
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org