Fix regressions BlockStats/Info APIs in QEMU driver

The change 18c2a592 caused
some regressions in behaviour of virDomainBlockStats
and virDomainBlockInfo in the QEMU driver.

The virDomainBlockInfo API stopped working for inactive
guests if querying a block device.

The virDomainBlockStats API did not promptly report
an error if the guest was not running in some cases.

* src/qemu/qemu_driver.c: Fix inactive guest handling
  in BlockStats/Info APIs

src/qemu/qemu_driver.c

@@ -5531,6 +5531,12 @@ qemudDomainBlockStats (virDomainPtr dom,
         goto cleanup;
     }
 
+    if (!virDomainObjIsActive(vm)) {
+        qemuReportError(VIR_ERR_OPERATION_INVALID,
+                        "%s", _("domain is not running"));
+        goto cleanup;
+    }
+
     for (i = 0 ; i < vm->def->ndisks ; i++) {
         if (STREQ(path, vm->def->disks[i]->dst)) {
             disk = vm->def->disks[i];
@@ -5994,7 +6000,8 @@ static int qemuDomainGetBlockInfo(virDomainPtr dom,
        highest allocated extent from QEMU */
     if (disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK &&
         format != VIR_STORAGE_FILE_RAW &&
-        S_ISBLK(sb.st_mode)) {
+        S_ISBLK(sb.st_mode) &&
+        virDomainObjIsActive(vm)) {
         qemuDomainObjPrivatePtr priv = vm->privateData;
 
         if ((priv->jobActive == QEMU_JOB_MIGRATION_OUT)
@@ -6017,19 +6024,16 @@ static int qemuDomainGetBlockInfo(virDomainPtr dom,
             if (qemuDomainObjBeginJob(vm) < 0)
                 goto cleanup;
 
-            if (!virDomainObjIsActive(vm)) {
-                qemuReportError(VIR_ERR_OPERATION_INVALID,
-                                "%s", _("domain is not running"));
-                goto endjob;
+            if (virDomainObjIsActive(vm)) {
+                qemuDomainObjEnterMonitor(vm);
+                ret = qemuMonitorGetBlockExtent(priv->mon,
+                                                disk->info.alias,
+                                                &info->allocation);
+                qemuDomainObjExitMonitor(vm);
+            } else {
+                ret = 0;
             }
 
-            qemuDomainObjEnterMonitor(vm);
-            ret = qemuMonitorGetBlockExtent(priv->mon,
-                                            disk->info.alias,
-                                            &info->allocation);
-            qemuDomainObjExitMonitor(vm);
-
-endjob:
             if (qemuDomainObjEndJob(vm) == 0)
                 vm = NULL;
         }