Set delay_resume_if_new on deptree snapshot origin.

(Must avoid activating snapshot origin more than once concurrently.)

WHATS_NEW_DM

@@ -1,5 +1,6 @@
 Version 1.02.75 - 
 ================================
+  Set delay_resume_if_new on deptree snapshot origin.
   Log value chosen in _find_config_bool like other variable types do.
   Synchronize with dead of dmeventd.
   Rename (Blk)DevNames/DevNos dmsetup header to (Blk)DevNamesUsed/DevNosUsed.

libdm/libdm-deptree.c

@@ -2358,8 +2358,10 @@ static int _load_node(struct dm_tree_node *dnode)
 	if ((r = dm_task_run(dmt))) {
 		r = dm_task_get_info(dmt, &dnode->info);
 		if (r && !dnode->info.inactive_table)
-			log_verbose("Suppressed %s identical table reload.",
-				    dnode->name);
+			log_verbose("Suppressed %s (%" PRIu32 ":%" PRIu32
+				    ") identical table reload.",
+				    dnode->name,
+				    dnode->info.major, dnode->info.minor);
 
 		existing_table_size = dm_task_get_existing_table_size(dmt);
 		if ((dnode->props.size_changed =
@@ -2548,6 +2550,12 @@ int dm_tree_node_add_snapshot_origin_target(struct dm_tree_node *dnode,
 	/* Resume snapshot origins after new snapshots */
 	dnode->activation_priority = 1;
 
+	/*
+	 * Don't resume the origin immediately in case it is a non-trivial 
+	 * target that must not be active more than once concurrently!
+	 */
+	origin_node->props.delay_resume_if_new = 1;
+
 	return 1;
 }