[PATCH v3 21/33] qemu-socket: pass monitor link to socket_get_fd directly

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Detecting monitor by current coroutine works bad when we are not in
coroutine context. And that's exactly so in nbd reconnect code, where
qio_channel_socket_connect_sync() is called from thread.

Add a possibility to pass monitor by hand, to be used in the following
commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/io/channel-socket.h    | 20 ++++++++++++++++++++
 include/qemu/sockets.h         |  2 +-
 io/channel-socket.c            | 17 +++++++++++++----
 tests/unit/test-util-sockets.c | 16 ++++++++--------
 util/qemu-sockets.c            | 10 +++++-----
 5 files changed, 47 insertions(+), 18 deletions(-)

diff --git a/include/io/channel-socket.h b/include/io/channel-socket.h
index e747e63514..6d0915420d 100644
--- a/include/io/channel-socket.h
+++ b/include/io/channel-socket.h
@@ -78,6 +78,23 @@ qio_channel_socket_new_fd(int fd,
                           Error **errp);
 
 
+/**
+ * qio_channel_socket_connect_sync_mon:
+ * @ioc: the socket channel object
+ * @addr: the address to connect to
+ * @mon: current monitor. If NULL, it will be detected by
+ *       current coroutine.
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Attempt to connect to the address @addr. This method
+ * will run in the foreground so the caller will not regain
+ * execution control until the connection is established or
+ * an error occurs.
+ */
+int qio_channel_socket_connect_sync_mon(QIOChannelSocket *ioc,
+                                        SocketAddress *addr,
+                                        Monitor *mon,
+                                        Error **errp);
 /**
  * qio_channel_socket_connect_sync:
  * @ioc: the socket channel object
@@ -88,6 +105,9 @@ qio_channel_socket_new_fd(int fd,
  * will run in the foreground so the caller will not regain
  * execution control until the connection is established or
  * an error occurs.
+ *
+ * This a wrapper, calling qio_channel_socket_connect_sync_mon()
+ * with @mon=NULL.
  */
 int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
                                     SocketAddress *addr,
diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 7d1f813576..cdf6f2413b 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
@@ -41,7 +41,7 @@ int unix_listen(const char *path, Error **errp);
 int unix_connect(const char *path, Error **errp);
 
 SocketAddress *socket_parse(const char *str, Error **errp);
-int socket_connect(SocketAddress *addr, Error **errp);
+int socket_connect(SocketAddress *addr, Monitor *mon, Error **errp);
 int socket_listen(SocketAddress *addr, int num, Error **errp);
 void socket_listen_cleanup(int fd, Error **errp);
 int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp);
diff --git a/io/channel-socket.c b/io/channel-socket.c
index de259f7eed..9dc42ca29d 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -135,14 +135,15 @@ qio_channel_socket_new_fd(int fd,
 }
 
 
-int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
-                                    SocketAddress *addr,
-                                    Error **errp)
+int qio_channel_socket_connect_sync_mon(QIOChannelSocket *ioc,
+                                        SocketAddress *addr,
+                                        Monitor *mon,
+                                        Error **errp)
 {
     int fd;
 
     trace_qio_channel_socket_connect_sync(ioc, addr);
-    fd = socket_connect(addr, errp);
+    fd = socket_connect(addr, mon, errp);
     if (fd < 0) {
         trace_qio_channel_socket_connect_fail(ioc);
         return -1;
@@ -158,6 +159,14 @@ int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
 }
 
 
+int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
+                                    SocketAddress *addr,
+                                    Error **errp)
+{
+    return qio_channel_socket_connect_sync_mon(ioc, addr, NULL, errp);
+}
+
+
 static void qio_channel_socket_connect_worker(QIOTask *task,
                                               gpointer opaque)
 {
diff --git a/tests/unit/test-util-sockets.c b/tests/unit/test-util-sockets.c
index 72b9246529..d902ecede7 100644
--- a/tests/unit/test-util-sockets.c
+++ b/tests/unit/test-util-sockets.c
@@ -90,7 +90,7 @@ static void test_socket_fd_pass_name_good(void)
     addr.type = SOCKET_ADDRESS_TYPE_FD;
     addr.u.fd.str = g_strdup(mon_fdname);
 
-    fd = socket_connect(&addr, &error_abort);
+    fd = socket_connect(&addr, NULL, &error_abort);
     g_assert_cmpint(fd, !=, -1);
     g_assert_cmpint(fd, !=, mon_fd);
     close(fd);
@@ -122,7 +122,7 @@ static void test_socket_fd_pass_name_bad(void)
     addr.type = SOCKET_ADDRESS_TYPE_FD;
     addr.u.fd.str = g_strdup(mon_fdname);
 
-    fd = socket_connect(&addr, &err);
+    fd = socket_connect(&addr, NULL, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -149,7 +149,7 @@ static void test_socket_fd_pass_name_nomon(void)
     addr.type = SOCKET_ADDRESS_TYPE_FD;
     addr.u.fd.str = g_strdup("myfd");
 
-    fd = socket_connect(&addr, &err);
+    fd = socket_connect(&addr, NULL, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -173,7 +173,7 @@ static void test_socket_fd_pass_num_good(void)
     addr.type = SOCKET_ADDRESS_TYPE_FD;
     addr.u.fd.str = g_strdup_printf("%d", sfd);
 
-    fd = socket_connect(&addr, &error_abort);
+    fd = socket_connect(&addr, NULL, &error_abort);
     g_assert_cmpint(fd, ==, sfd);
 
     fd = socket_listen(&addr, 1, &error_abort);
@@ -195,7 +195,7 @@ static void test_socket_fd_pass_num_bad(void)
     addr.type = SOCKET_ADDRESS_TYPE_FD;
     addr.u.fd.str = g_strdup_printf("%d", sfd);
 
-    fd = socket_connect(&addr, &err);
+    fd = socket_connect(&addr, NULL, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -218,7 +218,7 @@ static void test_socket_fd_pass_num_nocli(void)
     addr.type = SOCKET_ADDRESS_TYPE_FD;
     addr.u.fd.str = g_strdup_printf("%d", STDOUT_FILENO);
 
-    fd = socket_connect(&addr, &err);
+    fd = socket_connect(&addr, NULL, &err);
     g_assert_cmpint(fd, ==, -1);
     error_free_or_abort(&err);
 
@@ -247,10 +247,10 @@ static gpointer unix_client_thread_func(gpointer user_data)
 
     for (i = 0; i < ABSTRACT_SOCKET_VARIANTS; i++) {
         if (row->expect_connect[i]) {
-            fd = socket_connect(row->client[i], &error_abort);
+            fd = socket_connect(row->client[i], NULL, &error_abort);
             g_assert_cmpint(fd, >=, 0);
         } else {
-            fd = socket_connect(row->client[i], &err);
+            fd = socket_connect(row->client[i], NULL, &err);
             g_assert_cmpint(fd, ==, -1);
             error_free_or_abort(&err);
         }
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index 8af0278f15..8b7e3cc7bf 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -1116,9 +1116,9 @@ fail:
     return NULL;
 }
 
-static int socket_get_fd(const char *fdstr, int num, Error **errp)
+static int socket_get_fd(const char *fdstr, int num, Monitor *mon, Error **errp)
 {
-    Monitor *cur_mon = monitor_cur();
+    Monitor *cur_mon = mon ?: monitor_cur();
     int fd;
     if (num != 1) {
         error_setg_errno(errp, EINVAL, "socket_get_fd: too many connections");
@@ -1145,7 +1145,7 @@ static int socket_get_fd(const char *fdstr, int num, Error **errp)
     return fd;
 }
 
-int socket_connect(SocketAddress *addr, Error **errp)
+int socket_connect(SocketAddress *addr, Monitor *mon, Error **errp)
 {
     int fd;
 
@@ -1159,7 +1159,7 @@ int socket_connect(SocketAddress *addr, Error **errp)
         break;
 
     case SOCKET_ADDRESS_TYPE_FD:
-        fd = socket_get_fd(addr->u.fd.str, 1, errp);
+        fd = socket_get_fd(addr->u.fd.str, 1, mon, errp);
         break;
 
     case SOCKET_ADDRESS_TYPE_VSOCK:
@@ -1187,7 +1187,7 @@ int socket_listen(SocketAddress *addr, int num, Error **errp)
         break;
 
     case SOCKET_ADDRESS_TYPE_FD:
-        fd = socket_get_fd(addr->u.fd.str, num, errp);
+        fd = socket_get_fd(addr->u.fd.str, num, NULL, errp);
         break;
 
     case SOCKET_ADDRESS_TYPE_VSOCK:
-- 
2.29.2