block/nbd: implement .bdrv_cancel_in_flight

Just stop waiting for connection in existing requests.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210205163720.887197-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

block/nbd.c

@@ -2458,6 +2458,18 @@ static const char *const nbd_strong_runtime_opts[] = {
     NULL
 };
 
+static void nbd_cancel_in_flight(BlockDriverState *bs)
+{
+    BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+
+    reconnect_delay_timer_del(s);
+
+    if (s->state == NBD_CLIENT_CONNECTING_WAIT) {
+        s->state = NBD_CLIENT_CONNECTING_NOWAIT;
+        qemu_co_queue_restart_all(&s->free_sema);
+    }
+}
+
 static BlockDriver bdrv_nbd = {
     .format_name                = "nbd",
     .protocol_name              = "nbd",
@@ -2484,6 +2496,7 @@ static BlockDriver bdrv_nbd = {
     .bdrv_co_block_status       = nbd_client_co_block_status,
     .bdrv_dirname               = nbd_dirname,
     .strong_runtime_opts        = nbd_strong_runtime_opts,
+    .bdrv_cancel_in_flight      = nbd_cancel_in_flight,
 };
 
 static BlockDriver bdrv_nbd_tcp = {
@@ -2512,6 +2525,7 @@ static BlockDriver bdrv_nbd_tcp = {
     .bdrv_co_block_status       = nbd_client_co_block_status,
     .bdrv_dirname               = nbd_dirname,
     .strong_runtime_opts        = nbd_strong_runtime_opts,
+    .bdrv_cancel_in_flight      = nbd_cancel_in_flight,
 };
 
 static BlockDriver bdrv_nbd_unix = {
@@ -2540,6 +2554,7 @@ static BlockDriver bdrv_nbd_unix = {
     .bdrv_co_block_status       = nbd_client_co_block_status,
     .bdrv_dirname               = nbd_dirname,
     .strong_runtime_opts        = nbd_strong_runtime_opts,
+    .bdrv_cancel_in_flight      = nbd_cancel_in_flight,
 };
 
 static void bdrv_nbd_init(void)