[PULL 4/7] migration: Introduce migration_ioc_[un]register_yank()

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: Peter Xu <peterx@redhat.com>

There're plenty of places in migration/* that checks against either socket or
tls typed ioc for yank operations.  Provide two helpers to hide all these
information.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210722175841.938739-4-peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/channel.c           | 15 ++-------------
 migration/multifd.c           |  8 ++------
 migration/qemu-file-channel.c |  8 ++------
 migration/yank_functions.c    | 28 ++++++++++++++++++++++++++++
 migration/yank_functions.h    |  2 ++
 5 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/migration/channel.c b/migration/channel.c
index 01275a9162..c4fc000a1a 100644
--- a/migration/channel.c
+++ b/migration/channel.c
@@ -44,13 +44,7 @@ void migration_channel_process_incoming(QIOChannel *ioc)
                              TYPE_QIO_CHANNEL_TLS)) {
         migration_tls_channel_process_incoming(s, ioc, &local_err);
     } else {
-        if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
-            object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS)) {
-            yank_register_function(MIGRATION_YANK_INSTANCE,
-                                   migration_yank_iochannel,
-                                   QIO_CHANNEL(ioc));
-        }
-
+        migration_ioc_register_yank(ioc);
         migration_ioc_process_incoming(ioc, &local_err);
     }
 
@@ -94,12 +88,7 @@ void migration_channel_connect(MigrationState *s,
         } else {
             QEMUFile *f = qemu_fopen_channel_output(ioc);
 
-            if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
-                object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS)) {
-                yank_register_function(MIGRATION_YANK_INSTANCE,
-                                       migration_yank_iochannel,
-                                       QIO_CHANNEL(ioc));
-            }
+            migration_ioc_register_yank(ioc);
 
             qemu_mutex_lock(&s->qemu_file_lock);
             s->to_dst_file = f;
diff --git a/migration/multifd.c b/migration/multifd.c
index ab41590e71..377da78f5b 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -987,12 +987,8 @@ int multifd_load_cleanup(Error **errp)
     for (i = 0; i < migrate_multifd_channels(); i++) {
         MultiFDRecvParams *p = &multifd_recv_state->params[i];
 
-        if ((object_dynamic_cast(OBJECT(p->c), TYPE_QIO_CHANNEL_SOCKET) ||
-             object_dynamic_cast(OBJECT(p->c), TYPE_QIO_CHANNEL_TLS))
-            && OBJECT(p->c)->ref == 1) {
-            yank_unregister_function(MIGRATION_YANK_INSTANCE,
-                                     migration_yank_iochannel,
-                                     QIO_CHANNEL(p->c));
+        if (OBJECT(p->c)->ref == 1) {
+            migration_ioc_unregister_yank(p->c);
         }
 
         object_unref(OBJECT(p->c));
diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
index fad340ea7a..867a5ed0c3 100644
--- a/migration/qemu-file-channel.c
+++ b/migration/qemu-file-channel.c
@@ -107,12 +107,8 @@ static int channel_close(void *opaque, Error **errp)
     int ret;
     QIOChannel *ioc = QIO_CHANNEL(opaque);
     ret = qio_channel_close(ioc, errp);
-    if ((object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
-         object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS))
-        && OBJECT(ioc)->ref == 1) {
-        yank_unregister_function(MIGRATION_YANK_INSTANCE,
-                                 migration_yank_iochannel,
-                                 QIO_CHANNEL(ioc));
+    if (OBJECT(ioc)->ref == 1) {
+        migration_ioc_unregister_yank(ioc);
     }
     object_unref(OBJECT(ioc));
     return ret;
diff --git a/migration/yank_functions.c b/migration/yank_functions.c
index 96c90e17dc..23697173ae 100644
--- a/migration/yank_functions.c
+++ b/migration/yank_functions.c
@@ -11,6 +11,9 @@
 #include "qapi/error.h"
 #include "io/channel.h"
 #include "yank_functions.h"
+#include "qemu/yank.h"
+#include "io/channel-socket.h"
+#include "io/channel-tls.h"
 
 void migration_yank_iochannel(void *opaque)
 {
@@ -18,3 +21,28 @@ void migration_yank_iochannel(void *opaque)
 
     qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
 }
+
+/* Return whether yank is supported on this ioc */
+static bool migration_ioc_yank_supported(QIOChannel *ioc)
+{
+    return object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
+        object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS);
+}
+
+void migration_ioc_register_yank(QIOChannel *ioc)
+{
+    if (migration_ioc_yank_supported(ioc)) {
+        yank_register_function(MIGRATION_YANK_INSTANCE,
+                               migration_yank_iochannel,
+                               QIO_CHANNEL(ioc));
+    }
+}
+
+void migration_ioc_unregister_yank(QIOChannel *ioc)
+{
+    if (migration_ioc_yank_supported(ioc)) {
+        yank_unregister_function(MIGRATION_YANK_INSTANCE,
+                                 migration_yank_iochannel,
+                                 QIO_CHANNEL(ioc));
+    }
+}
diff --git a/migration/yank_functions.h b/migration/yank_functions.h
index 055ea22523..74c7f18c91 100644
--- a/migration/yank_functions.h
+++ b/migration/yank_functions.h
@@ -15,3 +15,5 @@
  * @opaque: QIOChannel to shutdown
  */
 void migration_yank_iochannel(void *opaque);
+void migration_ioc_register_yank(QIOChannel *ioc);
+void migration_ioc_unregister_yank(QIOChannel *ioc);
-- 
2.31.1