qemu: Refactor qemuDomainObjSetJobPhase

We will want to update migration phase without affecting job ownership.
Either in the thread that already owns the job or from an event handler
which only changes the phase (of a job no-one owns) without assuming it.

Let's move the ownership change to a new qemuDomainObjStartJobPhase
helper and let qemuDomainObjSetJobPhase set the phase without touching
ownership.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

src/qemu/qemu_domainjob.c

@@ -717,6 +717,10 @@ qemuDomainJobDataToParams(virDomainJobData *jobData,
 }
 
 
+/*
+ * Sets the job phase without changing the job owner. The owner is supposed to
+ * be 0 or the current thread, a warning is issued otherwise.
+ */
 void
 qemuDomainObjSetJobPhase(virDomainObj *obj,
                          int phase)
@@ -731,19 +735,51 @@ qemuDomainObjSetJobPhase(virDomainObj *obj,
               virDomainAsyncJobTypeToString(priv->job.asyncJob),
               qemuDomainAsyncJobPhaseToString(priv->job.asyncJob, phase));
 
-    if (priv->job.asyncOwner == 0) {
+    if (priv->job.asyncOwner != 0 &&
-        priv->job.asyncOwnerAPI = g_strdup(virThreadJobGet());
+        priv->job.asyncOwner != me) {
-    } else if (me != priv->job.asyncOwner) {
+        VIR_WARN("'%s' async job is owned by thread %llu, API '%s'",
-        VIR_WARN("'%s' async job is owned by thread %llu",
                  virDomainAsyncJobTypeToString(priv->job.asyncJob),
-                 priv->job.asyncOwner);
+                 priv->job.asyncOwner,
+                 NULLSTR(priv->job.asyncOwnerAPI));
     }
 
     priv->job.phase = phase;
-    priv->job.asyncOwner = me;
     qemuDomainSaveStatus(obj);
 }
 
+
+/*
+ * Changes the job owner and sets the job phase. The current owner is supposed
+ * to be 0 or the current thread, a warning is issued otherwise.
+ */
+void
+qemuDomainObjStartJobPhase(virDomainObj *obj,
+                           int phase)
+{
+    qemuDomainObjPrivate *priv = obj->privateData;
+    unsigned long long me = virThreadSelfID();
+
+    if (!priv->job.asyncJob)
+        return;
+
+    VIR_DEBUG("Starting phase '%s' of '%s' job",
+              qemuDomainAsyncJobPhaseToString(priv->job.asyncJob, phase),
+              virDomainAsyncJobTypeToString(priv->job.asyncJob));
+
+    if (priv->job.asyncOwner == 0) {
+        priv->job.asyncOwnerAPI = g_strdup(virThreadJobGet());
+    } else if (me != priv->job.asyncOwner) {
+        VIR_WARN("'%s' async job is owned by thread %llu, API '%s'",
+                 virDomainAsyncJobTypeToString(priv->job.asyncJob),
+                 priv->job.asyncOwner,
+                 NULLSTR(priv->job.asyncOwnerAPI));
+    }
+
+    priv->job.asyncOwner = me;
+    qemuDomainObjSetJobPhase(obj, phase);
+}
+
+
 void
 qemuDomainObjSetAsyncJobMask(virDomainObj *obj,
                              unsigned long long allowedJobs)

src/qemu/qemu_domainjob.h

@@ -156,6 +156,9 @@ void qemuDomainObjEndAsyncJob(virDomainObj *obj);
 void qemuDomainObjAbortAsyncJob(virDomainObj *obj);
 void qemuDomainObjSetJobPhase(virDomainObj *obj,
                               int phase);
+void
+qemuDomainObjStartJobPhase(virDomainObj *obj,
+                           int phase);
 void qemuDomainObjSetAsyncJobMask(virDomainObj *obj,
                                   unsigned long long allowedJobs);
 int qemuDomainObjPreserveJob(virDomainObj *obj,

src/qemu/qemu_migration.c

@@ -165,7 +165,7 @@ qemuMigrationJobSetPhase(virDomainObj *vm,
     if (qemuMigrationCheckPhase(vm, phase) < 0)
         return -1;
 
-    qemuDomainObjSetJobPhase(vm, phase);
+    qemuDomainObjStartJobPhase(vm, phase);
     return 0;
 }