qemu_block: add async domain job support to qemuBlockCommit

This will allow to use it while having async domain job active which we
will use when deleting external snapshots. At the same time we will need
to have the block job started as synchronous.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

src/qemu/qemu_block.c

@@ -3198,6 +3198,22 @@ qemuBlockExportAddNBD(virDomainObj *vm,
 }
 
 
+/**
+ * qemuBlockCommit:
+ * @vm: domain object
+ * @disk: disk object where we are about to block commit
+ * @baseSource: disk source within backing chain to commit data into
+ * @topSource: disk source within backing chain with data we will commit
+ * @top_parent: disk source that has @topSource as backing disk
+ * @bandwidth: bandwidth limit, flags determine the unit
+ * @asyncJob: qemu async job type
+ * @flags: bitwise-OR of virDomainBlockCommitFlags
+ *
+ * Starts a block commit job for @disk. If @asyncJob is different then
+ * VIR_ASYNC_JOB_NONE the job will be started as synchronous.
+ *
+ * Returns -1 on error, 0 on success.
+ */
 int
 qemuBlockCommit(virDomainObj *vm,
                 virDomainDiskDef *disk,
@@ -3205,6 +3221,7 @@ qemuBlockCommit(virDomainObj *vm,
                 virStorageSource *topSource,
                 virStorageSource *top_parent,
                 unsigned long bandwidth,
+                virDomainAsyncJob asyncJob,
                 unsigned int flags)
 {
     qemuDomainObjPrivate *priv = vm->privateData;
@@ -3336,7 +3353,11 @@ qemuBlockCommit(virDomainObj *vm,
         !(backingPath = qemuBlockGetBackingStoreString(baseSource, false)))
         goto cleanup;
 
-    qemuDomainObjEnterMonitor(vm);
+    if (asyncJob != VIR_ASYNC_JOB_NONE)
+        qemuBlockJobSyncBegin(job);
+
+    if (qemuDomainObjEnterMonitorAsync(vm, asyncJob) < 0)
+        goto cleanup;
 
     ret = qemuMonitorBlockCommit(priv->mon,
                                  qemuDomainDiskGetTopNodename(disk),

src/qemu/qemu_block.h

@@ -284,6 +284,7 @@ qemuBlockCommit(virDomainObj *vm,
                 virStorageSource *topSource,
                 virStorageSource *top_parent,
                 unsigned long bandwidth,
+                virDomainAsyncJob asyncJob,
                 unsigned int flags);
 
 int

src/qemu/qemu_driver.c

@@ -15025,7 +15025,8 @@ qemuDomainBlockCommit(virDomainPtr dom,
                                                         base, disk->dst, NULL)))
         goto endjob;
 
-    ret = qemuBlockCommit(vm, disk, baseSource, topSource, top_parent, bandwidth, flags);
+    ret = qemuBlockCommit(vm, disk, baseSource, topSource, top_parent,
+                          bandwidth, VIR_ASYNC_JOB_NONE, flags);
 
  endjob:
     virDomainObjEndJob(vm);