qemu: Use consistent error preservation and restoration calls

Provide some consistency over error message variable name and usage
when saving error messages across possible other errors or possibility
of resetting of the last error.

Instead of virSaveLastError paired up with virSetError and virFreeError,
we should use the newer virErrorPreserveLast and virRestoreError.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_cgroup.c

@@ -1149,12 +1149,11 @@ qemuSetupCgroupVcpuBW(virCgroupPtr cgroup,
 
  error:
     if (period) {
-        virErrorPtr saved = virSaveLastError();
+        virErrorPtr saved;
+
+        virErrorPreserveLast(&saved);
         ignore_value(virCgroupSetCpuCfsPeriod(cgroup, old_period));
-        if (saved) {
-            virSetError(saved);
-            virFreeError(saved);
-        }
+        virErrorRestore(&saved);
     }
 
     return -1;
@@ -1362,10 +1361,9 @@ qemuCgroupEmulatorAllNodesRestore(qemuCgroupEmulatorAllNodesDataPtr data)
     if (!data)
         return;
 
-    err = virSaveLastError();
+    virErrorPreserveLast(&err);
     virCgroupSetCpusetMems(data->emulatorCgroup, data->emulatorMemMask);
-    virSetError(err);
-    virFreeError(err);
+    virErrorRestore(&err);
 
     qemuCgroupEmulatorAllNodesDataFree(data);
 }

src/qemu/qemu_command.c

@@ -8644,10 +8644,11 @@ qemuBuildInterfaceCommandLine(virQEMUDriverPtr driver,
     ret = 0;
  cleanup:
     if (ret < 0) {
-        virErrorPtr saved_err = virSaveLastError();
+        virErrorPtr saved_err;
+
+        virErrorPreserveLast(&saved_err);
         virDomainConfNWFilterTeardown(net);
-        virSetError(saved_err);
-        virFreeError(saved_err);
+        virErrorRestore(&saved_err);
     }
     for (i = 0; vhostfd && i < vhostfdSize; i++) {
         if (ret < 0)
@@ -8730,11 +8731,10 @@ qemuBuildNetCommandLine(virQEMUDriverPtr driver,
  error:
     /* free up any resources in the network driver
      * but don't overwrite the original error */
-    originalError = virSaveLastError();
+    virErrorPreserveLast(&originalError);
     for (i = 0; last_good_net != -1 && i <= last_good_net; i++)
         virDomainConfNWFilterTeardown(def->nets[i]);
-    virSetError(originalError);
-    virFreeError(originalError);
+    virErrorRestore(&originalError);
     return -1;
 }
 

src/qemu/qemu_domain.c

@@ -9174,7 +9174,7 @@ void qemuDomainObjTaint(virQEMUDriverPtr driver,
     /* We don't care about errors logging taint info, so
      * preserve original error, and clear any error that
      * is raised */
-    orig_err = virSaveLastError();
+    virErrorPreserveLast(&orig_err);
 
     if (!(timestamp = virTimeStringNow()))
         goto cleanup;
@@ -9198,10 +9198,7 @@ void qemuDomainObjTaint(virQEMUDriverPtr driver,
 
  cleanup:
     VIR_FREE(timestamp);
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
 }
 
 

src/qemu/qemu_driver.c

@@ -3436,7 +3436,8 @@ qemuDomainSaveInternal(virQEMUDriverPtr driver,
  endjob:
     if (ret < 0) {
         if (was_running && virDomainObjIsActive(vm)) {
-            virErrorPtr save_err = virSaveLastError();
+            virErrorPtr save_err;
+            virErrorPreserveLast(&save_err);
             if (qemuProcessStartCPUs(driver, vm,
                                      VIR_DOMAIN_RUNNING_SAVE_CANCELED,
                                      QEMU_ASYNC_JOB_SAVE) < 0) {
@@ -3446,8 +3447,7 @@ qemuDomainSaveInternal(virQEMUDriverPtr driver,
                                          VIR_DOMAIN_EVENT_SUSPENDED,
                                          VIR_DOMAIN_EVENT_SUSPENDED_API_ERROR));
             }
-            virSetError(save_err);
-            virFreeError(save_err);
+            virErrorRestore(&save_err);
         }
     }
     qemuDomainObjEndAsyncJob(driver, vm);
@@ -6729,7 +6729,9 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
         goto cleanup;
 
     if (!virDomainDefCheckABIStability(def, newdef_migr, driver->xmlopt)) {
-        virErrorPtr err = virSaveLastError();
+        virErrorPtr save_err;
+
+        virErrorPreserveLast(&save_err);
 
         /* Due to a bug in older version of external snapshot creation
          * code, the XML saved in the save image was not a migratable
@@ -6738,11 +6740,10 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
          * the user provided XML if the check against the migratable XML
          * fails. Snapshots created prior to v1.1.3 have this issue. */
         if (!virDomainDefCheckABIStability(def, newdef, driver->xmlopt)) {
-            virSetError(err);
-            virFreeError(err);
+            virErrorRestore(&save_err);
             goto cleanup;
         }
-        virFreeError(err);
+        virFreeError(save_err);
 
         /* use the user provided XML */
         ret = g_steal_pointer(&newdef);
@@ -6991,7 +6992,7 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,
              * must manually kill it and ignore any error related to
              * the process
              */
-            orig_err = virSaveLastError();
+            virErrorPreserveLast(&orig_err);
             VIR_FORCE_CLOSE(intermediatefd);
             VIR_FORCE_CLOSE(*fd);
         }
@@ -7002,10 +7003,7 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,
         }
         VIR_DEBUG("Decompression binary stderr: %s", NULLSTR(errbuf));
 
-        if (orig_err) {
-            virSetError(orig_err);
-            virFreeError(orig_err);
-        }
+        virErrorRestore(&orig_err);
     }
     VIR_FORCE_CLOSE(intermediatefd);
 
@@ -14739,13 +14737,11 @@ qemuDomainSnapshotFSThaw(virQEMUDriverPtr driver G_GNUC_UNUSED,
 
     agent = qemuDomainObjEnterAgent(vm);
     if (!report)
-        err = virSaveLastError();
+        virErrorPreserveLast(&err);
     thawed = qemuAgentFSThaw(agent);
-    if (!report)
-        virSetError(err);
     qemuDomainObjExitAgent(vm, agent);
 
-    virFreeError(err);
+    virErrorRestore(&err);
 
     return thawed;
 }
@@ -18897,16 +18893,14 @@ qemuDomainBlockCommit(virDomainPtr dom,
 
  endjob:
     if (ret < 0 && clean_access) {
-        virErrorPtr orig_err = virSaveLastError();
+        virErrorPtr orig_err;
+        virErrorPreserveLast(&orig_err);
         /* Revert access to read-only, if possible.  */
         qemuDomainStorageSourceAccessAllow(driver, vm, baseSource, true, false);
         if (top_parent && top_parent != disk->src)
             qemuDomainStorageSourceAccessAllow(driver, vm, top_parent, true, false);
 
-        if (orig_err) {
-            virSetError(orig_err);
-            virFreeError(orig_err);
-        }
+        virErrorRestore(&orig_err);
     }
     qemuBlockJobStartupFinalize(vm, job);
     qemuDomainObjEndJob(driver, vm);

src/qemu/qemu_migration.c

@@ -728,7 +728,7 @@ qemuMigrationSrcNBDCopyCancel(virQEMUDriverPtr driver,
         if (rv != 0) {
             if (rv < 0) {
                 if (!err)
-                    err = virSaveLastError();
+                    virErrorPreserveLast(&err);
                 failed = true;
             }
             qemuBlockJobSyncEnd(vm, job, asyncJob);
@@ -753,7 +753,7 @@ qemuMigrationSrcNBDCopyCancel(virQEMUDriverPtr driver,
         }
 
         if (failed && !err)
-            err = virSaveLastError();
+            virErrorPreserveLast(&err);
 
         if (virDomainObjWait(vm) < 0)
             goto cleanup;
@@ -775,10 +775,7 @@ qemuMigrationSrcNBDCopyCancel(virQEMUDriverPtr driver,
     ret = failed ? -1 : 0;
 
  cleanup:
-    if (err) {
-        virSetError(err);
-        virFreeError(err);
-    }
+    virErrorRestore(&err);
     return ret;
 }
 
@@ -3001,15 +2998,16 @@ qemuMigrationSrcConfirmPhase(virQEMUDriverPtr driver,
         virObjectEventStateQueue(driver->domainEventState, event);
         qemuDomainEventEmitJobCompleted(driver, vm);
     } else {
-        virErrorPtr orig_err = virSaveLastError();
+        virErrorPtr orig_err;
         int reason;
 
+        virErrorPreserveLast(&orig_err);
+
         /* cancel any outstanding NBD jobs */
         qemuMigrationSrcNBDCopyCancel(driver, vm, false,
                                       QEMU_ASYNC_JOB_MIGRATION_OUT, NULL);
 
-        virSetError(orig_err);
-        virFreeError(orig_err);
+        virErrorRestore(&orig_err);
 
         if (virDomainObjGetState(vm, &reason) == VIR_DOMAIN_PAUSED &&
             reason == VIR_DOMAIN_PAUSED_POSTCOPY)
@@ -3213,16 +3211,13 @@ static void qemuMigrationSrcIOFunc(void *arg)
     return;
 
  abrt:
-    err = virSaveLastError();
+    virErrorPreserveLast(&err);
     if (err && err->code == VIR_ERR_OK) {
         virFreeError(err);
         err = NULL;
     }
     virStreamAbort(data->st);
-    if (err) {
-        virSetError(err);
-        virFreeError(err);
-    }
+    virErrorRestore(&err);
 
  error:
     /* Let the source qemu know that the transfer cant continue anymore.
@@ -3704,15 +3699,12 @@ qemuMigrationSrcRun(virQEMUDriverPtr driver,
     if (events)
         priv->signalIOError = false;
 
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
 
     return ret;
 
  error:
-    orig_err = virSaveLastError();
+    virErrorPreserveLast(&orig_err);
 
     if (virDomainObjIsActive(vm)) {
         if (cancel &&
@@ -3967,7 +3959,7 @@ qemuMigrationSrcPerformPeer2Peer2(virQEMUDriverPtr driver,
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("domainMigratePrepare2 did not set uri"));
         cancelled = true;
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
         goto finish;
     }
 
@@ -3990,7 +3982,7 @@ qemuMigrationSrcPerformPeer2Peer2(virQEMUDriverPtr driver,
 
     /* Perform failed. Make sure Finish doesn't overwrite the error */
     if (ret < 0)
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
 
     /* If Perform returns < 0, then we need to cancel the VM
      * startup on the destination
@@ -4023,10 +4015,7 @@ qemuMigrationSrcPerformPeer2Peer2(virQEMUDriverPtr driver,
 
     virObjectUnref(st);
 
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
     VIR_FREE(uri_out);
     VIR_FREE(cookie);
 
@@ -4200,13 +4189,13 @@ qemuMigrationSrcPerformPeer2Peer3(virQEMUDriverPtr driver,
         if (useParams &&
             virTypedParamsReplaceString(&params, &nparams,
                                         VIR_MIGRATE_PARAM_URI, uri_out) < 0) {
-            orig_err = virSaveLastError();
+            virErrorPreserveLast(&orig_err);
             goto finish;
         }
     } else if (!uri && !(flags & VIR_MIGRATE_TUNNELLED)) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("domainMigratePrepare3 did not set uri"));
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
         goto finish;
     }
 
@@ -4239,7 +4228,7 @@ qemuMigrationSrcPerformPeer2Peer3(virQEMUDriverPtr driver,
 
     /* Perform failed. Make sure Finish doesn't overwrite the error */
     if (ret < 0) {
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
     } else {
         qemuMigrationJobSetPhase(driver, vm,
                                  QEMU_MIGRATION_PHASE_PERFORM3_DONE);
@@ -4331,7 +4320,7 @@ qemuMigrationSrcPerformPeer2Peer3(virQEMUDriverPtr driver,
      * one we need to preserve it in case confirm3 overwrites
      */
     if (!orig_err)
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
 
     /*
      * If cancelled, then src VM will be restarted, else
@@ -4363,10 +4352,7 @@ qemuMigrationSrcPerformPeer2Peer3(virQEMUDriverPtr driver,
 
     virObjectUnref(st);
 
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
     VIR_FREE(uri_out);
     VIR_FREE(cookiein);
     VIR_FREE(cookieout);
@@ -4542,15 +4528,12 @@ qemuMigrationSrcPerformPeer2Peer(virQEMUDriverPtr driver,
     }
 
  cleanup:
-    orig_err = virSaveLastError();
+    virErrorPreserveLast(&orig_err);
     qemuDomainObjEnterRemote(vm);
     virConnectUnregisterCloseCallback(dconn, qemuMigrationSrcConnectionClosed);
     virObjectUnref(dconn);
     ignore_value(qemuDomainObjExitRemote(vm, false));
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
     virObjectUnref(cfg);
     return ret;
 }
@@ -4639,7 +4622,7 @@ qemuMigrationSrcPerformJob(virQEMUDriverPtr driver,
 
  endjob:
     if (ret < 0)
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
 
     /* v2 proto has no confirm phase so we need to reset migration parameters
      * here
@@ -4659,10 +4642,7 @@ qemuMigrationSrcPerformJob(virQEMUDriverPtr driver,
         qemuDomainRemoveInactiveJob(driver, vm);
     }
 
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
 
  cleanup:
     virObjectEventStateQueue(driver->domainEventState, event);
@@ -5074,7 +5054,7 @@ qemuMigrationDstFinish(virQEMUDriverPtr driver,
             /* Need to save the current error, in case shutting
              * down the process overwrites it
              */
-            orig_err = virSaveLastError();
+            virErrorPreserveLast(&orig_err);
 
             /*
              * In v3 protocol, the source VM is still available to
@@ -5203,10 +5183,7 @@ qemuMigrationDstFinish(virQEMUDriverPtr driver,
     VIR_FREE(priv->origname);
     virDomainObjEndAPI(&vm);
     qemuMigrationCookieFree(mig);
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
     virObjectUnref(cfg);
 
     /* Set a special error if Finish is expected to return NULL as a result of
@@ -5311,7 +5288,7 @@ qemuMigrationSrcToFile(virQEMUDriverPtr driver, virDomainObjPtr vm,
 
     if (rc < 0) {
         if (rc == -2) {
-            orig_err = virSaveLastError();
+            virErrorPreserveLast(&orig_err);
             virCommandAbort(cmd);
             if (virDomainObjIsActive(vm) &&
                 qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) == 0) {
@@ -5330,7 +5307,7 @@ qemuMigrationSrcToFile(virQEMUDriverPtr driver, virDomainObjPtr vm,
 
  cleanup:
     if (ret < 0 && !orig_err)
-        orig_err = virSaveLastError();
+        virErrorPreserveLast(&orig_err);
 
     /* Restore max migration bandwidth */
     if (virDomainObjIsActive(vm) &&
@@ -5348,10 +5325,7 @@ qemuMigrationSrcToFile(virQEMUDriverPtr driver, virDomainObjPtr vm,
         virCommandFree(cmd);
     }
 
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
 
     return ret;
 }
@@ -5539,8 +5513,7 @@ qemuMigrationDstErrorReport(virQEMUDriverPtr driver,
 
     VIR_DEBUG("Restoring saved incoming migration error for domain %s: %s",
               name, err->message);
-    virSetError(err);
-    virFreeError(err);
+    virErrorRestore(&err);
 }
 
 

src/qemu/qemu_migration_params.c

@@ -1197,7 +1197,9 @@ qemuMigrationParamsReset(virQEMUDriverPtr driver,
                          qemuMigrationParamsPtr origParams,
                          unsigned long apiFlags)
 {
-    virErrorPtr err = virSaveLastError();
+    virErrorPtr err;
+
+    virErrorPreserveLast(&err);
 
     VIR_DEBUG("Resetting migration parameters %p, flags 0x%lx",
               origParams, apiFlags);
@@ -1211,10 +1213,7 @@ qemuMigrationParamsReset(virQEMUDriverPtr driver,
     qemuMigrationParamsResetTLS(driver, vm, asyncJob, origParams, apiFlags);
 
  cleanup:
-    if (err) {
-        virSetError(err);
-        virFreeError(err);
-    }
+    virErrorRestore(&err);
 }
 
 

src/qemu/qemu_monitor.c

@@ -929,17 +929,17 @@ qemuMonitorClose(qemuMonitorPtr mon)
      */
     if (mon->msg) {
         if (mon->lastError.code == VIR_ERR_OK) {
-            virErrorPtr err = virSaveLastError();
+            virErrorPtr err;
+
+            virErrorPreserveLast(&err);
 
             virReportError(VIR_ERR_OPERATION_FAILED, "%s",
                            _("QEMU monitor was closed"));
             virCopyLastError(&mon->lastError);
-            if (err) {
-                virSetError(err);
-                virFreeError(err);
-            } else {
+            if (err)
+                virErrorRestore(&err);
+            else
                 virResetLastError();
-            }
         }
         mon->msg->finished = 1;
         virCondSignal(&mon->notify);
@@ -2671,17 +2671,14 @@ qemuMonitorCloseFileHandle(qemuMonitorPtr mon,
 
     VIR_DEBUG("fdname=%s", fdname);
 
-    error = virSaveLastError();
+    virErrorPreserveLast(&error);
 
     QEMU_CHECK_MONITOR_GOTO(mon, cleanup);
 
     ret = qemuMonitorJSONCloseFileHandle(mon, fdname);
 
  cleanup:
-    if (error) {
-        virSetError(error);
-        virFreeError(error);
-    }
+    virErrorRestore(&error);
     return ret;
 }
 

src/qemu/qemu_process.c

@@ -7412,7 +7412,7 @@ void qemuProcessStop(virQEMUDriverPtr driver,
 
     /* This method is routinely used in clean up paths. Disable error
      * reporting so we don't squash a legit error. */
-    orig_err = virSaveLastError();
+    virErrorPreserveLast(&orig_err);
 
     if (asyncJob != QEMU_ASYNC_JOB_NONE) {
         if (qemuDomainObjBeginNestedJob(driver, vm, asyncJob) < 0)
@@ -7705,10 +7705,7 @@ void qemuProcessStop(virQEMUDriverPtr driver,
         qemuDomainObjEndJob(driver, vm);
 
  cleanup:
-    if (orig_err) {
-        virSetError(orig_err);
-        virFreeError(orig_err);
-    }
+    virErrorRestore(&orig_err);
     virObjectUnref(conn);
     virObjectUnref(cfg);
 }