storage: Fill in 'type' field for virStorageSource in storage driver

Storage driver uses virStorageSource only partially to store it's
configuration but fully when parsing backing files of storage volumes.
This patch sets the 'type' field to a value other than
VIR_STORAGE_TYPE_NONE so that further patches can add a terminator
element to backing chains without breaking iteration.

src/conf/storage_conf.c

@@ -1109,6 +1109,8 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool,
     if (VIR_ALLOC(ret) < 0)
         return NULL;
 
+    ret->target.type = VIR_STORAGE_TYPE_FILE;
+
     ret->name = virXPathString("string(./name)", ctxt);
     if (ret->name == NULL) {
         virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -1133,6 +1135,8 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool,
         if (VIR_ALLOC(ret->target.backingStore) < 0)
             goto error;
 
+        ret->target.backingStore->type = VIR_STORAGE_TYPE_FILE;
+
         ret->target.backingStore->path = backingStore;
         backingStore = NULL;
 

src/storage/storage_backend_gluster.c

@@ -306,6 +306,8 @@ virStorageBackendGlusterRefreshVol(virStorageBackendGlusterStatePtr state,
         if (VIR_ALLOC(vol->target.backingStore) < 0)
             goto cleanup;
 
+        vol->target.backingStore->type = VIR_STORAGE_TYPE_NETWORK;
+
         vol->target.backingStore->path = meta->backingStoreRaw;
 
         if (backingFormat < 0)

src/storage/storage_backend_logical.c

@@ -340,6 +340,7 @@ virStorageBackendLogicalMakeVol(char **const groups,
             goto cleanup;
 
         vol->target.backingStore->format = VIR_STORAGE_POOL_LOGICAL_LVM2;
+        vol->target.backingStore->type = VIR_STORAGE_TYPE_BLOCK;
     }
 
     if (!vol->key && VIR_STRDUP(vol->key, groups[2]) < 0)