Add deactivation functions

libdm/.exported_symbols

@@ -82,3 +82,4 @@ dm_hash_get_data
 dm_hash_get_first
 dm_hash_get_next
 dm_driver_version
+dm_deptree_deactivate_children

libdm/libdevmapper.h

@@ -246,6 +246,13 @@ const struct dm_info *dm_deptree_node_get_info(struct deptree_node *node);
  */
 int dm_deptree_node_num_children(struct deptree_node *node, uint32_t inverted);
 
+/*
+ * Deactivate a device with its dependencies if the uuid prefix matches
+ */
+int dm_deptree_deactivate_children(struct deptree_node *dnode,
+				   const char *uuid_prefix,
+				   size_t uuid_prefix_len);
+
 /*****************************************************************************
  * Library functions
  *****************************************************************************/

libdm/libdm-deptree.c

@@ -399,3 +399,107 @@ struct deptree_node *dm_deptree_next_child(void **handle,
 	return (*dlink) ? list_item(*dlink, struct deptree_link)->node : NULL;
 }
 
+/*
+ * Deactivate a device with its dependencies if the uuid prefix matches
+ */
+static int _info_by_dev(uint32_t major, uint32_t minor, struct dm_info *info)
+{
+	struct dm_task *dmt;
+	int r;
+
+	if (!(dmt = dm_task_create(DM_DEVICE_INFO))) {
+		log_error("_info_by_dev: dm_task creation failed");
+		return 0;
+	}
+
+	if (!dm_task_set_major(dmt, major) || !dm_task_set_minor(dmt, minor)) {
+		log_error("_info_by_dev: Failed to set device number");
+		dm_task_destroy(dmt);
+		return 0;
+	}
+
+	if ((r = dm_task_run(dmt)))
+		r = dm_task_get_info(dmt, info);
+
+	dm_task_destroy(dmt);
+
+	return r;
+}
+
+static int _deactivate_node(const char *name, uint32_t major, uint32_t minor)
+{
+	struct dm_task *dmt;
+	int r;
+
+	log_verbose("Removing %s (%" PRIu32 ":%" PRIu32 ")", name, major, minor);
+
+	if (!(dmt = dm_task_create(DM_DEVICE_REMOVE))) {
+		log_error("Deactivation dm_task creation failed for %s", name);
+		return 0;
+	}
+
+	if (!dm_task_set_major(dmt, major) || !dm_task_set_minor(dmt, minor)) {
+		log_error("Failed to set device number for %s deactivation", name);
+		dm_task_destroy(dmt);
+		return 0;
+	}
+
+	if (!dm_task_no_open_count(dmt))
+		log_error("Failed to disable open_count");
+
+	r = dm_task_run(dmt);
+
+	dm_task_destroy(dmt);
+
+	return r;
+}
+
+int dm_deptree_deactivate_children(struct deptree_node *dnode, const char *uuid_prefix, size_t uuid_prefix_len)
+{
+	void *handle = NULL;
+	struct deptree_node *child = dnode;
+	struct dm_info info;
+	const struct dm_info *dinfo;
+	const char *name;
+	const char *uuid;
+
+	while ((child = dm_deptree_next_child(&handle, dnode, 0))) {
+		if (!(dinfo = dm_deptree_node_get_info(child))) {
+			stack;
+			continue;
+		}
+
+		if (!(name = dm_deptree_node_get_name(child))) {
+			stack;
+			continue;
+		}
+
+		if (!(uuid = dm_deptree_node_get_uuid(child))) {
+			stack;
+			continue;
+		}
+
+		/* Ignore if it doesn't belong to this VG */
+		if (strncmp(uuid, uuid_prefix, uuid_prefix_len)) {
+			stack;
+			continue;
+		}
+
+		/* Refresh open_count */
+		if (!_info_by_dev(dinfo->major, dinfo->minor, &info) ||
+		    !info.exists || info.open_count)
+			continue;
+
+		if (!_deactivate_node(name, info.major, info.minor)) {
+			log_error("Unable to deactivate %s (%" PRIu32
+				  ":%" PRIu32 ")", name, info.major,
+				  info.minor);
+			continue;
+		}
+
+		if (dm_deptree_node_num_children(child, 0))
+			dm_deptree_deactivate_children(child, uuid_prefix, uuid_prefix_len);
+	}
+
+	return 1;
+}