qemu: Don't reuse variable in processSerialChangedEvent()

When a VSERPORT_CHANGE event is processed, we firstly do a little
detour and try to detect whether the event is coming from guest
agent. If so, we notify threads that are currently talking to the
agent about this fact. Then we proceed with usual event
processing (BeginJob(), update domain def, emit event, and so
on).

In both cases we use the same @dev variable to refer to domain
device. While this works, it will make writing semantic patch
unnecessary harder (see next commit(s)). Therefore, introduce a
separate variable for the detour code.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Claudio Fontana <cfontana@suse.de>

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 1d7b78d73b0eec42912b559dbce33a81d9198939..1f388306f49a3a4c0cf31d6d0df2daf50f843667 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -3781,20 +3781,19 @@ processSerialChangedEvent(virQEMUDriver *driver,
 
     if (newstate == VIR_DOMAIN_CHR_DEVICE_STATE_DISCONNECTED &&
         virDomainObjIsActive(vm) && priv->agent) {
+        virDomainDeviceDef agentDev;
+
         /* peek into the domain definition to find the channel */
-        if (virDomainDefFindDevice(vm->def, devAlias, &dev, true) == 0 &&
-            dev.type == VIR_DOMAIN_DEVICE_CHR &&
-            dev.data.chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL &&
-            dev.data.chr->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO &&
-            STREQ_NULLABLE(dev.data.chr->target.name, "org.qemu.guest_agent.0"))
+        if (virDomainDefFindDevice(vm->def, devAlias, &agentDev, true) == 0 &&
+            agentDev.type == VIR_DOMAIN_DEVICE_CHR &&
+            agentDev.data.chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL &&
+            agentDev.data.chr->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO &&
+            STREQ_NULLABLE(agentDev.data.chr->target.name, "org.qemu.guest_agent.0")) {
             /* Close agent monitor early, so that other threads
              * waiting for the agent to reply can finish and our
              * job we acquire below can succeed. */
             qemuAgentNotifyClose(priv->agent);
-
-        /* now discard the data, since it may possibly change once we unlock
-         * while entering the job */
-        memset(&dev, 0, sizeof(dev));
+        }
     }
 
     if (virDomainObjBeginJob(vm, VIR_JOB_MODIFY_MIGRATION_SAFE) < 0)