virDomainDiskTranslateSourcePool: Translate 'volume' disks in whole backing chain

Now that we accept full backing chains on input nothing should prevent
users from also using disk type 'VOLUME' for specifying the backing
images.

Do the translation for the whole backing chain.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/conf/domain_conf.c

@@ -31562,18 +31562,20 @@ int
 virDomainDiskTranslateSourcePool(virDomainDiskDefPtr def)
 {
     g_autoptr(virConnect) conn = NULL;
+    virStorageSourcePtr n;
 
-    if (def->src->type != VIR_STORAGE_TYPE_VOLUME)
-        return 0;
-
-    if (!def->src->srcpool)
-        return 0;
+    for (n = def->src; virStorageSourceIsBacking(n); n = n->backingStore) {
+        if (n->type != VIR_STORAGE_TYPE_VOLUME || !n->srcpool)
+            continue;
 
-    if (!(conn = virGetConnectStorage()))
-        return -1;
+        if (!conn) {
+            if (!(conn = virGetConnectStorage()))
+                return -1;
+        }
 
-    if (virDomainStorageSourceTranslateSourcePool(def->src, conn) < 0)
-        return -1;
+        if (virDomainStorageSourceTranslateSourcePool(n, conn) < 0)
+            return -1;
+    }
 
     if (def->startupPolicy != 0 &&
         virStorageSourceGetActualType(def->src) != VIR_STORAGE_VOL_FILE) {