[libvirt] [PATCH 6/7] qemu: snapshot: Refactor event creation when reverting snapshots

[Peter Krempa]

The internal snapshot revert code used a very unintuitive approach to
create lifecycle events while doing the revert. Refactor the code to use
the new automagic function to do the revertion.
---
 src/qemu/qemu_driver.c | 76 +++++++++-----------------------------------------
 1 file changed, 13 insertions(+), 63 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index e794e02..1f98f4a 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -14047,16 +14047,12 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
     virDomainObjPtr vm = NULL;
     int ret = -1;
     virDomainSnapshotObjPtr snap = NULL;
-    virObjectEventPtr event = NULL;
-    virObjectEventPtr event2 = NULL;
-    int detail;
     qemuDomainObjPrivatePtr priv;
     int rc;
     virDomainDefPtr config = NULL;
     virQEMUDriverConfigPtr cfg = NULL;
     virCapsPtr caps = NULL;
-    bool was_running = false;
-    bool was_stopped = false;
+    int oldState = vm->state.state;

     virCheckFlags(VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING |
                   VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED |
@@ -14187,24 +14183,18 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                 qemuDomainSnapshotEmitLifecycleEvent(driver, vm,
                                                      vm->state.state,
                                                      VIR_DOMAIN_SHUTOFF);
+                oldState = VIR_DOMAIN_SHUTOFF;
                 goto load;
             }

             priv = vm->privateData;
             if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) {
                 /* Transitions 5, 6 */
-                was_running = true;
                 if (qemuProcessStopCPUs(driver, vm,
                                         VIR_DOMAIN_PAUSED_FROM_SNAPSHOT,
                                         QEMU_ASYNC_JOB_NONE) < 0)
                     goto endjob;
-                /* Create an event now in case the restore fails, so
-                 * that user will be alerted that they are now paused.
-                 * If restore later succeeds, we might replace this. */
-                detail = VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT;
-                event = virDomainEventLifecycleNewFromObj(vm,
-                                                 VIR_DOMAIN_EVENT_SUSPENDED,
-                                                 detail);
+
                 if (!virDomainObjIsActive(vm)) {
                     virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                                    _("guest unexpectedly quit"));
@@ -14224,7 +14214,6 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
         } else {
             /* Transitions 2, 3 */
         load:
-            was_stopped = true;
             if (config)
                 virDomainObjAssignDef(vm, config, false, NULL);

@@ -14233,10 +14222,7 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                                   VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
                                   VIR_QEMU_PROCESS_START_PAUSED);
             virDomainAuditStart(vm, "from-snapshot", rc >= 0);
-            detail = VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT;
-            event = virDomainEventLifecycleNewFromObj(vm,
-                                             VIR_DOMAIN_EVENT_STARTED,
-                                             detail);
+
             if (rc < 0)
                 goto endjob;
         }
@@ -14248,13 +14234,6 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
             /* Transitions 3, 6, 9 */
             virDomainObjSetState(vm, VIR_DOMAIN_PAUSED,
                                  VIR_DOMAIN_PAUSED_FROM_SNAPSHOT);
-            if (was_stopped) {
-                /* Transition 3, use event as-is and add event2 */
-                detail = VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT;
-                event2 = virDomainEventLifecycleNewFromObj(vm,
-                                                  VIR_DOMAIN_EVENT_SUSPENDED,
-                                                  detail);
-            } /* else transition 6 and 9 use event as-is */
         } else {
             /* Transitions 2, 5, 8 */
             if (!virDomainObjIsActive(vm)) {
@@ -14267,21 +14246,6 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                                       QEMU_ASYNC_JOB_NONE);
             if (rc < 0)
                 goto endjob;
-            virObjectUnref(event);
-            event = NULL;
-            if (was_stopped) {
-                /* Transition 2 */
-                detail = VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT;
-                event = virDomainEventLifecycleNewFromObj(vm,
-                                                 VIR_DOMAIN_EVENT_STARTED,
-                                                 detail);
-            } else if (was_running) {
-                /* Transition 8 */
-                detail = VIR_DOMAIN_EVENT_RESUMED;
-                event = virDomainEventLifecycleNewFromObj(vm,
-                                                 VIR_DOMAIN_EVENT_RESUMED,
-                                                 detail);
-            }
         }
         break;

@@ -14300,10 +14264,9 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
             /* Transitions 4, 7 */
             qemuProcessStop(driver, vm, VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT, 0);
             virDomainAuditStop(vm, "from-snapshot");
-            detail = VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT;
-            event = virDomainEventLifecycleNewFromObj(vm,
-                                             VIR_DOMAIN_EVENT_STOPPED,
-                                             detail);
+            qemuDomainSnapshotEmitLifecycleEvent(driver, vm, vm->state.state,
+                                                 VIR_DOMAIN_SHUTOFF);
+            oldState = VIR_DOMAIN_SHUTOFF;
         }

         if (qemuDomainSnapshotRevertInactive(driver, vm, snap) < 0) {
@@ -14326,8 +14289,6 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,

             start_flags |= paused ? VIR_QEMU_PROCESS_START_PAUSED : 0;

-            if (event)
-                qemuDomainEventQueue(driver, event);
             rc = qemuProcessStart(snapshot->domain->conn,
                                   driver, vm, NULL, -1, NULL, NULL,
                                   VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
@@ -14342,16 +14303,6 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                 }
                 goto endjob;
             }
-            detail = VIR_DOMAIN_EVENT_STARTED_FROM_SNAPSHOT;
-            event = virDomainEventLifecycleNewFromObj(vm,
-                                             VIR_DOMAIN_EVENT_STARTED,
-                                             detail);
-            if (paused) {
-                detail = VIR_DOMAIN_EVENT_SUSPENDED_FROM_SNAPSHOT;
-                event2 = virDomainEventLifecycleNewFromObj(vm,
-                                                  VIR_DOMAIN_EVENT_SUSPENDED,
-                                                  detail);
-            }
         }
         break;

@@ -14381,13 +14332,12 @@ static int qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
     } else if (snap) {
         snap->def->current = false;
     }
-    if (event) {
-        qemuDomainEventQueue(driver, event);
-        if (event2)
-            qemuDomainEventQueue(driver, event2);
-    }
-    if (vm)
-        virObjectUnlock(vm);
+
+    /* emit all appropriate events */
+    qemuDomainSnapshotEmitLifecycleEvent(driver, vm, oldState,
+                                         vm->state.state);
+
+    virObjectUnlock(vm);
     virObjectUnref(caps);
     virObjectUnref(cfg);

-- 
2.0.0