qemu: Split out preparing of single snapshot from qemuDomainSnapshotDiskDataCollect

Move the internals into qemuDomainSnapshotDiskDataCollectOne to make it
obvious what's happening after moving more code here.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_driver.c

@@ -15302,46 +15302,24 @@ qemuDomainSnapshotDiskDataCleanup(qemuDomainSnapshotDiskDataPtr data,
 }
 
 
-/**
- * qemuDomainSnapshotDiskDataCollect:
- *
- * Collects and prepares a list of structures that hold information about disks
- * that are selected for the snapshot.
- */
 static int
-qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
+qemuDomainSnapshotDiskDataCollectOne(virQEMUDriverPtr driver,
                                      virDomainObjPtr vm,
-                                  virDomainMomentObjPtr snap,
-                                  bool reuse,
-                                  qemuDomainSnapshotDiskDataPtr *rdata,
-                                  size_t *rndata)
+                                     virDomainDiskDefPtr disk,
+                                     virDomainSnapshotDiskDefPtr snapdisk,
+                                     qemuDomainSnapshotDiskDataPtr dd,
+                                     bool reuse)
 {
-    size_t i;
-    qemuDomainSnapshotDiskDataPtr data;
-    size_t ndata = 0;
-    qemuDomainSnapshotDiskDataPtr dd;
     char *backingStoreStr;
-    virDomainSnapshotDefPtr snapdef = virDomainSnapshotObjGetDef(snap);
     virDomainDiskDefPtr persistdisk;
-    int ret = -1;
-
-    if (VIR_ALLOC_N(data, snapdef->ndisks) < 0)
-        return -1;
-
-    for (i = 0; i < snapdef->ndisks; i++) {
-        if (snapdef->disks[i].snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE)
-            continue;
-
-        dd = data + ndata;
-        ndata++;
 
-        dd->disk = vm->def->disks[i];
+    dd->disk = disk;
 
-        if (!(dd->src = virStorageSourceCopy(snapdef->disks[i].src, false)))
-            goto cleanup;
+    if (!(dd->src = virStorageSourceCopy(snapdisk->src, false)))
+        return -1;
 
     if (virStorageSourceInitChainElement(dd->src, dd->disk->src, false) < 0)
-            goto cleanup;
+        return -1;
 
     /* modify disk in persistent definition only when the source is the same */
     if (vm->newDef &&
@@ -15351,15 +15329,15 @@ qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
         dd->persistdisk = persistdisk;
 
         if (!(dd->persistsrc = virStorageSourceCopy(dd->src, false)))
-                goto cleanup;
+            return -1;
 
         if (virStorageSourceInitChainElement(dd->persistsrc,
                                              dd->persistdisk->src, false) < 0)
-                goto cleanup;
+            return -1;
     }
 
     if (qemuDomainStorageFileInit(driver, vm, dd->src, NULL) < 0)
-            goto cleanup;
+        return -1;
 
     dd->initialized = true;
 
@@ -15367,7 +15345,7 @@ qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
      * block commit still works */
     if (reuse) {
         if (virStorageFileGetBackingStoreStr(dd->src, &backingStoreStr) < 0)
-                goto cleanup;
+            return -1;
         if (backingStoreStr != NULL) {
             if (virStorageIsRelative(backingStoreStr))
                 VIR_STEAL_PTR(dd->relPath, backingStoreStr);
@@ -15375,6 +15353,42 @@ qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
                 VIR_FREE(backingStoreStr);
         }
     }
+
+    return 0;
+}
+
+
+/**
+ * qemuDomainSnapshotDiskDataCollect:
+ *
+ * Collects and prepares a list of structures that hold information about disks
+ * that are selected for the snapshot.
+ */
+static int
+qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
+                                  virDomainObjPtr vm,
+                                  virDomainMomentObjPtr snap,
+                                  bool reuse,
+                                  qemuDomainSnapshotDiskDataPtr *rdata,
+                                  size_t *rndata)
+{
+    size_t i;
+    qemuDomainSnapshotDiskDataPtr data;
+    size_t ndata = 0;
+    virDomainSnapshotDefPtr snapdef = virDomainSnapshotObjGetDef(snap);
+    int ret = -1;
+
+    if (VIR_ALLOC_N(data, snapdef->ndisks) < 0)
+        return -1;
+
+    for (i = 0; i < snapdef->ndisks; i++) {
+        if (snapdef->disks[i].snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE)
+            continue;
+
+        if (qemuDomainSnapshotDiskDataCollectOne(driver, vm, vm->def->disks[i],
+                                                 snapdef->disks + i,
+                                                 data + ndata++, reuse) < 0)
+            goto cleanup;
     }
 
     VIR_STEAL_PTR(*rdata, data);