qemu: Aggregate interlocking of blockjobs by checkpoints in one place

Rather than having to fix 5 places once we support the combination, add
a function called by all the blockjob/snapshot APIs.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

src/qemu/qemu_domain.c

@@ -15513,3 +15513,24 @@ qemuDomainDefHasManagedPR(virDomainObjPtr vm)
 
     return jobPR;
 }
+
+
+/**
+ * qemuDomainSupportsCheckpointsBlockjobs:
+ * @vm: domain object
+ *
+ * Checks whether a block job is supported in possible combination with
+ * checkpoints (qcow2 bitmaps). Returns -1 if unsupported and reports an error
+ * 0 in case everything is supported.
+ */
+int
+qemuDomainSupportsCheckpointsBlockjobs(virDomainObjPtr vm)
+{
+    if (virDomainListCheckpoints(vm->checkpoints, NULL, NULL, NULL, 0) > 0) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("cannot perform block operations while checkpoint exists"));
+        return -1;
+    }
+
+    return 0;
+}

src/qemu/qemu_domain.h

@@ -1217,3 +1217,7 @@ qemuDomainPausedReasonToSuspendedEvent(virDomainPausedReason reason);
 int
 qemuDomainValidateActualNetDef(const virDomainNetDef *net,
                                virQEMUCapsPtr qemuCaps);
+
+int
+qemuDomainSupportsCheckpointsBlockjobs(virDomainObjPtr vm)
+    ATTRIBUTE_RETURN_CHECK;

src/qemu/qemu_driver.c

@@ -15836,11 +15836,8 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
     if (virDomainSnapshotCreateXMLEnsureACL(domain->conn, vm->def, flags) < 0)
         goto cleanup;
 
-    if (virDomainListCheckpoints(vm->checkpoints, NULL, domain, NULL, 0) > 0) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot create snapshot while checkpoint exists"));
+    if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0)
         goto cleanup;
-    }
 
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         goto cleanup;
@@ -18364,11 +18361,8 @@ qemuDomainBlockRebase(virDomainPtr dom, const char *path, const char *base,
     if (virDomainBlockRebaseEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
-    if (virDomainListCheckpoints(vm->checkpoints, NULL, dom, NULL, 0) > 0) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot perform block rebase while checkpoint exists"));
+    if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0)
         goto cleanup;
-    }
 
     /* For normal rebase (enhanced blockpull), the common code handles
      * everything, including vm cleanup. */
@@ -18454,11 +18448,8 @@ qemuDomainBlockCopy(virDomainPtr dom, const char *disk, const char *destxml,
     if (virDomainBlockCopyEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
-    if (virDomainListCheckpoints(vm->checkpoints, NULL, dom, NULL, 0) > 0) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot perform block copy while checkpoint exists"));
+    if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0)
         goto cleanup;
-    }
 
     for (i = 0; i < nparams; i++) {
         virTypedParameterPtr param = &params[i];
@@ -18522,11 +18513,8 @@ qemuDomainBlockPull(virDomainPtr dom, const char *path, unsigned long bandwidth,
     if (virDomainBlockPullEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
-    if (virDomainListCheckpoints(vm->checkpoints, NULL, dom, NULL, 0) > 0) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot perform block pull while checkpoint exists"));
+    if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0)
         goto cleanup;
-    }
 
     ret = qemuDomainBlockPullCommon(vm, path, NULL, bandwidth, flags);
 
@@ -18581,11 +18569,8 @@ qemuDomainBlockCommit(virDomainPtr dom,
     if (virDomainBlockCommitEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
-    if (virDomainListCheckpoints(vm->checkpoints, NULL, dom, NULL, 0) > 0) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot perform block commit while checkpoint exists"));
+    if (qemuDomainSupportsCheckpointsBlockjobs(vm) < 0)
         goto cleanup;
-    }
 
     if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
         goto cleanup;