qemuDomainAttachDiskGeneric: Refactor rollback handling

Modify the rollback section to use its own monitor context so that we
can later split up the hotplug into multiple steps and move the
detachment of the extension device into the rollback section rather than
doing it inline.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 6bfc900e3f88c90e9e79435c7f7879adaf3143bd..0fe6893c873996a3302ea89f9cb08701ad7c8d15 100644 (file)
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -699,6 +699,8 @@ qemuDomainAttachDiskGeneric(virQEMUDriver *driver,
     qemuDomainObjPrivate *priv = vm->privateData;
     g_autofree char *devstr = NULL;
     bool blockdev = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV);
+    bool extensionDeviceAttached = false;
+    int rc;
 
     if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
         if (!(data = qemuBuildStorageSourceChainAttachPrepareChardev(disk)))
@@ -726,16 +728,14 @@ qemuDomainAttachDiskGeneric(virQEMUDriver *driver,
 
     qemuDomainObjEnterMonitor(driver, vm);
 
-    if (qemuBlockStorageSourceChainAttach(priv->mon, data) < 0)
-        goto exit_monitor;
+    rc = qemuBlockStorageSourceChainAttach(priv->mon, data);
 
-    if (qemuDomainAttachExtensionDevice(priv->mon, &disk->info) < 0)
-        goto exit_monitor;
+    if (rc == 0 &&
+        (rc = qemuDomainAttachExtensionDevice(priv->mon, &disk->info)) == 0)
+        extensionDeviceAttached = true;
 
-    if (qemuMonitorAddDevice(priv->mon, devstr) < 0) {
-        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &disk->info));
-        goto exit_monitor;
-    }
+    if (rc == 0)
+        rc = qemuMonitorAddDevice(priv->mon, devstr);
 
     /* Setup throttling of disk via block_set_io_throttle QMP command. This
      * is a hack until the 'throttle' blockdev driver will support modification
@@ -743,7 +743,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriver *driver,
      * As there isn't anything sane to do if this fails, let's just return
      * success.
      */
-    if (blockdev &&
+    if (blockdev && rc == 0 &&
         qemuDiskConfigBlkdeviotuneEnabled(disk)) {
         qemuDomainDiskPrivate *diskPriv = QEMU_DOMAIN_DISK_PRIVATE(disk);
         if (qemuMonitorSetBlockIoThrottle(priv->mon, NULL, diskPriv->qomName,
@@ -755,9 +755,17 @@ qemuDomainAttachDiskGeneric(virQEMUDriver *driver,
     if (qemuDomainObjExitMonitor(driver, vm) < 0)
         return -2;
 
+    if (rc < 0)
+        goto rollback;
+
     return 0;
 
- exit_monitor:
+ rollback:
+    qemuDomainObjEnterMonitor(driver, vm);
+
+    if (extensionDeviceAttached)
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &disk->info));
+
     qemuBlockStorageSourceChainDetach(priv->mon, data);
 
     if (qemuDomainObjExitMonitor(driver, vm) < 0)