[libvirt] [PATCH v2] qemuDomainObjBeginJobInternal: Report agent job in error message

[Michal Privoznik]

If a thread is unable to acquire a job (e.g. because of timeout)
an error is reported and the error message contains reference to
the other thread holding the job. Well, the error message should
report agent job too as it is yet another source of possible
failure.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---

diff to v1:
- Expand messages to cover all @blocker and @agentBlocker possibilities
  (as Jira requested in review)

 src/qemu/qemu_domain.c | 46 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 38 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 95c3e3a8aa..3410774781 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -6420,6 +6420,7 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver,
     bool async = job == QEMU_JOB_ASYNC;
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     const char *blocker = NULL;
+    const char *agentBlocker = NULL;
     int ret = -1;
     unsigned long long duration = 0;
     unsigned long long agentDuration = 0;
@@ -6549,16 +6550,32 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver,
              priv->job.apiFlags,
              duration / 1000, agentDuration / 1000, asyncDuration / 1000);
 
-    if (nested || qemuDomainNestedJobAllowed(priv, job))
-        blocker = priv->job.ownerAPI;
-    else
-        blocker = priv->job.asyncOwnerAPI;
+    if (job) {
+        if (nested || qemuDomainNestedJobAllowed(priv, job))
+            blocker = priv->job.ownerAPI;
+        else
+            blocker = priv->job.asyncOwnerAPI;
+    }
+
+    if (agentJob)
+        agentBlocker = priv->job.agentOwnerAPI;
 
     if (errno == ETIMEDOUT) {
-        if (blocker) {
+        if (blocker && agentBlocker) {
             virReportError(VIR_ERR_OPERATION_TIMEOUT,
-                           _("cannot acquire state change lock (held by %s)"),
+                           _("cannot acquire state change "
+                             "lock (held by monitor=%s agent=%s)"),
+                           blocker, agentBlocker);
+        } else if (blocker) {
+            virReportError(VIR_ERR_OPERATION_TIMEOUT,
+                           _("cannot acquire state change "
+                             "lock (held by monitor=%s)"),
                            blocker);
+        } else if (agentBlocker) {
+            virReportError(VIR_ERR_OPERATION_TIMEOUT,
+                           _("cannot acquire state change "
+                             "lock (held by agent=%s)"),
+                           agentBlocker);
         } else {
             virReportError(VIR_ERR_OPERATION_TIMEOUT, "%s",
                            _("cannot acquire state change lock"));
@@ -6566,11 +6583,24 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver,
         ret = -2;
     } else if (cfg->maxQueuedJobs &&
                priv->jobs_queued > cfg->maxQueuedJobs) {
-        if (blocker) {
+        if (blocker && agentBlocker) {
             virReportError(VIR_ERR_OPERATION_FAILED,
-                           _("cannot acquire state change lock (held by %s) "
+                           _("cannot acquire state change "
+                             "lock (held by monitor=%s agent=%s) "
+                             "due to max_queued limit"),
+                           blocker, agentBlocker);
+        } else if (blocker) {
+            virReportError(VIR_ERR_OPERATION_FAILED,
+                           _("cannot acquire state change "
+                             "lock (held by monitor=%s) "
                              "due to max_queued limit"),
                            blocker);
+        } else if (agentBlocker) {
+            virReportError(VIR_ERR_OPERATION_FAILED,
+                           _("cannot acquire state change "
+                             "lock (held by agent=%s) "
+                             "due to max_queued limit"),
+                           agentBlocker);
         } else {
             virReportError(VIR_ERR_OPERATION_FAILED, "%s",
                            _("cannot acquire state change lock "
-- 
2.16.4