block/nbd: make nbd_co_establish_connection_cancel() bs-independent

nbd_co_establish_connection_cancel() actually needs only pointer to
NBDConnectThread. So, make it clean.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-14-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

1 files changed, 9 insertions, 8 deletions

diff --git a/block/nbd.c b/block/nbd.c
index 15b569a899..bee615e5c4 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -132,7 +132,7 @@ static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr,
                                     Error **errp);
 static coroutine_fn QIOChannelSocket *
 nbd_co_establish_connection(NBDConnectThread *thr, Error **errp);
-static void nbd_co_establish_connection_cancel(BlockDriverState *bs);
+static void nbd_co_establish_connection_cancel(NBDConnectThread *thr);
 static int nbd_client_handshake(BlockDriverState *bs, Error **errp);
 static void nbd_yank(void *opaque);
 
@@ -295,7 +295,7 @@ static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs)
     s->drained = true;
     qemu_co_sleep_wake(&s->reconnect_sleep);
 
-    nbd_co_establish_connection_cancel(bs);
+    nbd_co_establish_connection_cancel(s->connect_thread);
 
     reconnect_delay_timer_del(s);
 
@@ -333,7 +333,7 @@ static void nbd_teardown_connection(BlockDriverState *bs)
     s->state = NBD_CLIENT_QUIT;
     if (s->connection_co) {
         qemu_co_sleep_wake(&s->reconnect_sleep);
-        nbd_co_establish_connection_cancel(bs);
+        nbd_co_establish_connection_cancel(s->connect_thread);
     }
     if (qemu_in_coroutine()) {
         s->teardown_co = qemu_coroutine_self();
@@ -488,13 +488,14 @@ nbd_co_establish_connection(NBDConnectThread *thr, Error **errp)
 
 /*
  * nbd_co_establish_connection_cancel
- * Cancel nbd_co_establish_connection asynchronously: it will finish soon, to
- * allow drained section to begin.
+ * Cancel nbd_co_establish_connection() asynchronously.
+ *
+ * Note that this function neither directly stops the thread nor closes the
+ * socket, but rather safely wakes nbd_co_establish_connection() which is
+ * sleeping in yield()
  */
-static void nbd_co_establish_connection_cancel(BlockDriverState *bs)
+static void nbd_co_establish_connection_cancel(NBDConnectThread *thr)
 {
-    BDRVNBDState *s = bs->opaque;
-    NBDConnectThread *thr = s->connect_thread;
     Coroutine *wait_co;
 
     qemu_mutex_lock(&thr->mutex);