From fd460ef561a630cebb384e43dfe42b6d280c168f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Fri, 15 May 2020 16:33:43 +0100
Subject: [PATCH] qemu: stop checking virObjectUnref return value
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Some, but not all, of the monitor event handlers check
the virObjectUnref return value to see if the domain
was disposed.

It should not be possible for this to happen, since
the function already holds a lock on the domain and
has only just acquired an extra reference on the
domain a few lines earlier.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 src/qemu/qemu_process.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 999e576e5b..d36088ba98 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -307,7 +307,7 @@ qemuProcessHandleMonitorEOF(qemuMonitorPtr mon,
     processEvent->vm = virObjectRef(vm);
 
     if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-        ignore_value(virObjectUnref(vm));
+        virObjectUnref(vm);
         qemuProcessEventFree(processEvent);
         goto cleanup;
     }
@@ -840,15 +840,13 @@ qemuProcessHandleWatchdog(qemuMonitorPtr mon G_GNUC_UNUSED,
              */
             processEvent->vm = virObjectRef(vm);
             if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-                if (!virObjectUnref(vm))
-                    vm = NULL;
+                virObjectUnref(vm);
                 qemuProcessEventFree(processEvent);
             }
         }
     }
 
-    if (vm)
-        virObjectUnlock(vm);
+    virObjectUnlock(vm);
     virObjectEventStateQueue(driver->domainEventState, watchdogEvent);
     virObjectEventStateQueue(driver->domainEventState, lifecycleEvent);
 
@@ -977,7 +975,7 @@ qemuProcessHandleBlockJob(qemuMonitorPtr mon G_GNUC_UNUSED,
         processEvent->status = status;
 
         if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-            ignore_value(virObjectUnref(vm));
+            virObjectUnref(vm);
             goto cleanup;
         }
 
@@ -1039,7 +1037,7 @@ qemuProcessHandleJobStatusChange(qemuMonitorPtr mon G_GNUC_UNUSED,
         processEvent->data = virObjectRef(job);
 
         if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-            ignore_value(virObjectUnref(vm));
+            virObjectUnref(vm);
             goto cleanup;
         }
 
@@ -1342,14 +1340,12 @@ qemuProcessHandleGuestPanic(qemuMonitorPtr mon G_GNUC_UNUSED,
     processEvent->vm = virObjectRef(vm);
 
     if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-        if (!virObjectUnref(vm))
-            vm = NULL;
+        virObjectUnref(vm);
         qemuProcessEventFree(processEvent);
     }
 
  cleanup:
-    if (vm)
-        virObjectUnlock(vm);
+    virObjectUnlock(vm);
 
     return 0;
 }
@@ -1383,7 +1379,7 @@ qemuProcessHandleDeviceDeleted(qemuMonitorPtr mon G_GNUC_UNUSED,
     processEvent->vm = virObjectRef(vm);
 
     if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-        ignore_value(virObjectUnref(vm));
+        virObjectUnref(vm);
         goto error;
     }
 
@@ -1554,7 +1550,7 @@ qemuProcessHandleNicRxFilterChanged(qemuMonitorPtr mon G_GNUC_UNUSED,
     processEvent->vm = virObjectRef(vm);
 
     if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-        ignore_value(virObjectUnref(vm));
+        virObjectUnref(vm);
         goto error;
     }
 
@@ -1593,7 +1589,7 @@ qemuProcessHandleSerialChanged(qemuMonitorPtr mon G_GNUC_UNUSED,
     processEvent->vm = virObjectRef(vm);
 
     if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-        ignore_value(virObjectUnref(vm));
+        virObjectUnref(vm);
         goto error;
     }
 
@@ -1873,14 +1869,12 @@ qemuProcessHandleGuestCrashloaded(qemuMonitorPtr mon G_GNUC_UNUSED,
     processEvent->vm = virObjectRef(vm);
 
     if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
-        if (!virObjectUnref(vm))
-            vm = NULL;
+        virObjectUnref(vm);
         qemuProcessEventFree(processEvent);
     }
 
  cleanup:
-    if (vm)
-        virObjectUnlock(vm);
+    virObjectUnlock(vm);
 
     return 0;
 }