libdm-deptree.c

Linux Device Mapper Source Code

	}

	dnode->props.read_only = read_only ? 1 : 0;

	if (clear_inactive && !_node_clear_table(dnode))
		return_NULL;

	dnode->context = context;

	return dnode;
}

int dm_tree_add_dev(struct dm_tree *dtree, uint32_t major, uint32_t minor)
{
	return _add_dev(dtree, &dtree->root, major, minor) ? 1 : 0;
}

const char *dm_tree_node_get_name(struct dm_tree_node *node)
{
	return node->info.exists ? node->name : "";
}

const char *dm_tree_node_get_uuid(struct dm_tree_node *node)
{
	return node->info.exists ? node->uuid : "";
}

const struct dm_info *dm_tree_node_get_info(struct dm_tree_node *node)
{
	return &node->info;
}

void *dm_tree_node_get_context(struct dm_tree_node *node)
{
	return node->context;
}

int dm_tree_node_num_children(struct dm_tree_node *node, uint32_t inverted)
{
	if (inverted) {
		if (_nodes_are_linked(&node->dtree->root, node))
			return 0;
		return list_size(&node->used_by);
	}

	if (_nodes_are_linked(node, &node->dtree->root))
		return 0;

	return list_size(&node->uses);
}

/*
 * Returns 1 if no prefix supplied
 */
static int _uuid_prefix_matches(const char *uuid, const char *uuid_prefix, size_t uuid_prefix_len)
{
	if (!uuid_prefix)
		return 1;

	if (!strncmp(uuid, uuid_prefix, uuid_prefix_len))
		return 1;

	/* Handle transition: active device uuids might be missing the prefix */
	if (uuid_prefix_len <= 4)
		return 0;

	if (!strncmp(uuid, UUID_PREFIX, sizeof(UUID_PREFIX) - 1))
		return 0;

	if (strncmp(uuid_prefix, UUID_PREFIX, sizeof(UUID_PREFIX) - 1))
		return 0;

	if (!strncmp(uuid, uuid_prefix + sizeof(UUID_PREFIX) - 1, uuid_prefix_len - (sizeof(UUID_PREFIX) - 1)))
		return 1;

	return 0;
}

/*
 * Returns 1 if no children.
 */
static int _children_suspended(struct dm_tree_node *node,
			       uint32_t inverted,
			       const char *uuid_prefix,
			       size_t uuid_prefix_len)
{
	struct list *list;
	struct dm_tree_link *dlink;
	const struct dm_info *dinfo;
	const char *uuid;

	if (inverted) {
		if (_nodes_are_linked(&node->dtree->root, node))
			return 1;
		list = &node->used_by;
	} else {
		if (_nodes_are_linked(node, &node->dtree->root))
			return 1;
		list = &node->uses;
	}

	list_iterate_items(dlink, list) {
		if (!(uuid = dm_tree_node_get_uuid(dlink->node))) {
			stack;
			continue;
		}

		/* Ignore if it doesn't belong to this VG */
		if (!_uuid_prefix_matches(uuid, uuid_prefix, uuid_prefix_len))
			continue;

		if (!(dinfo = dm_tree_node_get_info(dlink->node))) {
			stack;	/* FIXME Is this normal? */
			return 0;
		}

		if (!dinfo->suspended)
			return 0;
	}

	return 1;
}

/*
 * Set major and minor to zero for root of tree.
 */
struct dm_tree_node *dm_tree_find_node(struct dm_tree *dtree,
					  uint32_t major,
					  uint32_t minor)
{
	if (!major && !minor)
		return &dtree->root;

	return _find_dm_tree_node(dtree, major, minor);
}

/*
 * Set uuid to NULL for root of tree.
 */
struct dm_tree_node *dm_tree_find_node_by_uuid(struct dm_tree *dtree,
						  const char *uuid)
{
	if (!uuid || !*uuid)
		return &dtree->root;

	return _find_dm_tree_node_by_uuid(dtree, uuid);
}

/*
 * First time set *handle to NULL.
 * Set inverted to invert the tree.
 */
struct dm_tree_node *dm_tree_next_child(void **handle,
					   struct dm_tree_node *parent,
					   uint32_t inverted)
{
	struct list **dlink = (struct list **) handle;
	struct list *use_list;

	if (inverted)
		use_list = &parent->used_by;
	else
		use_list = &parent->uses;

	if (!*dlink)
		*dlink = list_first(use_list);
	else
		*dlink = list_next(use_list, *dlink);

	return (*dlink) ? list_item(*dlink, struct dm_tree_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, int with_open_count,
			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 (!with_open_count && !dm_task_no_open_count(dmt))
		log_error("Failed to disable open_count");

	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);

	/* FIXME Until kernel returns actual name so dm-ioctl.c can handle it */
	rm_dev_node(name);

	/* FIXME Remove node from tree or mark invalid? */

	dm_task_destroy(dmt);

	return r;
}

static int _rename_node(const char *old_name, const char *new_name, uint32_t major, uint32_t minor)
{
	struct dm_task *dmt;
	int r = 0;

	log_verbose("Renaming %s (%" PRIu32 ":%" PRIu32 ") to %s", old_name, major, minor, new_name);

	if (!(dmt = dm_task_create(DM_DEVICE_RENAME))) {
		log_error("Rename dm_task creation failed for %s", old_name);
		return 0;
	}

	if (!dm_task_set_name(dmt, old_name)) {
		log_error("Failed to set name for %s rename.", old_name);
		goto out;
	}

	if (!dm_task_set_newname(dmt, new_name))
                goto_out;

	if (!dm_task_no_open_count(dmt))
		log_error("Failed to disable open_count");

	r = dm_task_run(dmt);

out:
	dm_task_destroy(dmt);

	return r;
}

/* FIXME Merge with _suspend_node? */
static int _resume_node(const char *name, uint32_t major, uint32_t minor,
			struct dm_info *newinfo)
{
	struct dm_task *dmt;
	int r;

	log_verbose("Resuming %s (%" PRIu32 ":%" PRIu32 ")", name, major, minor);

	if (!(dmt = dm_task_create(DM_DEVICE_RESUME))) {
		log_error("Suspend 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 resumption.", name);
		dm_task_destroy(dmt);
		return 0;
	}

	if (!dm_task_no_open_count(dmt))
		log_error("Failed to disable open_count");

	if ((r = dm_task_run(dmt)))
		r = dm_task_get_info(dmt, newinfo);

	dm_task_destroy(dmt);

	return r;
}

static int _suspend_node(const char *name, uint32_t major, uint32_t minor,
			 int skip_lockfs, int no_flush, struct dm_info *newinfo)
{
	struct dm_task *dmt;
	int r;

	log_verbose("Suspending %s (%" PRIu32 ":%" PRIu32 ")%s%s",
		    name, major, minor,
		    skip_lockfs ? "" : " with filesystem sync",
		    no_flush ? "" : " without device flush");

	if (!(dmt = dm_task_create(DM_DEVICE_SUSPEND))) {
		log_error("Suspend 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 suspension.", name);
		dm_task_destroy(dmt);
		return 0;
	}

	if (!dm_task_no_open_count(dmt))
		log_error("Failed to disable open_count");

	if (skip_lockfs && !dm_task_skip_lockfs(dmt))
		log_error("Failed to set skip_lockfs flag.");

	if (no_flush && !dm_task_no_flush(dmt))
		log_error("Failed to set no_flush flag.");

	if ((r = dm_task_run(dmt)))
		r = dm_task_get_info(dmt, newinfo);

	dm_task_destroy(dmt);

	return r;
}

int dm_tree_deactivate_children(struct dm_tree_node *dnode,
				   const char *uuid_prefix,
				   size_t uuid_prefix_len)
{
	void *handle = NULL;
	struct dm_tree_node *child = dnode;
	struct dm_info info;
	const struct dm_info *dinfo;
	const char *name;
	const char *uuid;

	while ((child = dm_tree_next_child(&handle, dnode, 0))) {
		if (!(dinfo = dm_tree_node_get_info(child))) {
			stack;
			continue;
		}

		if (!(name = dm_tree_node_get_name(child))) {
			stack;
			continue;
		}

		if (!(uuid = dm_tree_node_get_uuid(child))) {
			stack;
			continue;
		}

		/* Ignore if it doesn't belong to this VG */
		if (!_uuid_prefix_matches(uuid, uuid_prefix, uuid_prefix_len))
			continue;

		/* Refresh open_count */
		if (!_info_by_dev(dinfo->major, dinfo->minor, 1, &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_tree_node_num_children(child, 0))
			dm_tree_deactivate_children(child, uuid_prefix, uuid_prefix_len);
	}

	return 1;
}

void dm_tree_skip_lockfs(struct dm_tree_node *dnode)
{
	dnode->dtree->skip_lockfs = 1;
}

void dm_tree_use_no_flush_suspend(struct dm_tree_node *dnode)
{
	dnode->dtree->no_flush = 1;
}

int dm_tree_suspend_children(struct dm_tree_node *dnode,
				   const char *uuid_prefix,
				   size_t uuid_prefix_len)
{
	void *handle = NULL;
	struct dm_tree_node *child = dnode;
	struct dm_info info, newinfo;
	const struct dm_info *dinfo;
	const char *name;
	const char *uuid;

	/* Suspend nodes at this level of the tree */
	while ((child = dm_tree_next_child(&handle, dnode, 0))) {
		if (!(dinfo = dm_tree_node_get_info(child))) {
			stack;
			continue;
		}

		if (!(name = dm_tree_node_get_name(child))) {
			stack;
			continue;
		}

		if (!(uuid = dm_tree_node_get_uuid(child))) {
			stack;
			continue;
		}

		/* Ignore if it doesn't belong to this VG */
		if (!_uuid_prefix_matches(uuid, uuid_prefix, uuid_prefix_len))
			continue;

		/* Ensure immediate parents are already suspended */
		if (!_children_suspended(child, 1, uuid_prefix, uuid_prefix_len))
			continue;

		if (!_info_by_dev(dinfo->major, dinfo->minor, 0, &info) ||
		    !info.exists || info.suspended)
			continue;

		if (!_suspend_node(name, info.major, info.minor,
				   child->dtree->skip_lockfs,
				   child->dtree->no_flush, &newinfo)) {
			log_error("Unable to suspend %s (%" PRIu32
				  ":%" PRIu32 ")", name, info.major,
				  info.minor);
			continue;
		}

		/* Update cached info */
		child->info = newinfo;
	}

	/* Then suspend any child nodes */
	handle = NULL;

	while ((child = dm_tree_next_child(&handle, dnode, 0))) {
		if (!(uuid = dm_tree_node_get_uuid(child))) {
			stack;
			continue;
		}

		/* Ignore if it doesn't belong to this VG */
		if (!_uuid_prefix_matches(uuid, uuid_prefix, uuid_prefix_len))
			continue;

		if (dm_tree_node_num_children(child, 0))
			dm_tree_suspend_children(child, uuid_prefix, uuid_prefix_len);
	}

	return 1;
}

int dm_tree_activate_children(struct dm_tree_node *dnode,
				 const char *uuid_prefix,
				 size_t uuid_prefix_len)
{
	void *handle = NULL;
	struct dm_tree_node *child = dnode;
	struct dm_info newinfo;
	const char *name;
	const char *uuid;
	int priority;

	/* Activate children first */
	while ((child = dm_tree_next_child(&handle, dnode, 0))) {
		if (!(uuid = dm_tree_node_get_uuid(child))) {
			stack;
			continue;
		}

		if (!_uuid_prefix_matches(uuid, uuid_prefix, uuid_prefix_len))
			continue;

		if (dm_tree_node_num_children(child, 0))
			dm_tree_activate_children(child, uuid_prefix, uuid_prefix_len);
	}

	handle = NULL;

	for (priority = 0; priority < 2; priority++) {
		while ((child = dm_tree_next_child(&handle, dnode, 0))) {
			if (!(uuid = dm_tree_node_get_uuid(child))) {
				stack;
				continue;
			}

			if (!_uuid_prefix_matches(uuid, uuid_prefix, uuid_prefix_len))
				continue;

			if (priority != child->activation_priority)
				continue;

			if (!(name = dm_tree_node_get_name(child))) {
				stack;
				continue;
			}

			/* Rename? */
			if (child->props.new_name) {
				if (!_rename_node(name, child->props.new_name, child->info.major, child->info.minor)) {
					log_error("Failed to rename %s (%" PRIu32
						  ":%" PRIu32 ") to %s", name, child->info.major,
						  child->info.minor, child->props.new_name);
					return 0;
				}
				child->name = child->props.new_name;
				child->props.new_name = NULL;
			}

			if (!child->info.inactive_table && !child->info.suspended)
				continue;

			if (!_resume_node(name, child->info.major, child->info.minor, &newinfo)) {
				log_error("Unable to resume %s (%" PRIu32
					  ":%" PRIu32 ")", name, child->info.major,
					  child->info.minor);
				continue;
			}

			/* Update cached info */
			child->info = newinfo;
		}
	}

	handle = NULL;

	return 1;
}

static int _create_node(struct dm_tree_node *dnode)
{
	int r = 0;
	struct dm_task *dmt;

	log_verbose("Creating %s", dnode->name);

	if (!(dmt = dm_task_create(DM_DEVICE_CREATE))) {
		log_error("Create dm_task creation failed for %s", dnode->name);
		return 0;
	}

	if (!dm_task_set_name(dmt, dnode->name)) {
		log_error("Failed to set device name for %s", dnode->name);
		goto out;
	}

	if (!dm_task_set_uuid(dmt, dnode->uuid)) {
		log_error("Failed to set uuid for %s", dnode->name);
		goto out;
	}

	if (dnode->props.major &&
	    (!dm_task_set_major(dmt, dnode->props.major) ||
	     !dm_task_set_minor(dmt, dnode->props.minor))) {
		log_error("Failed to set device number for %s creation.", dnode->name);
		goto out;
	}

	if (dnode->props.read_only && !dm_task_set_ro(dmt)) {
		log_error("Failed to set read only flag for %s", dnode->name);
		goto out;
	}

	if (!dm_task_no_open_count(dmt))
		log_error("Failed to disable open_count");

	if ((r = dm_task_run(dmt)))
		r = dm_task_get_info(dmt, &dnode->info);

out:
	dm_task_destroy(dmt);

	return r;
}


static int _build_dev_string(char *devbuf, size_t bufsize, struct dm_tree_node *node)
{
	if (!dm_format_dev(devbuf, bufsize, node->info.major, node->info.minor)) {
                log_error("Failed to format %s device number for %s as dm "
                          "target (%u,%u)",
                          node->name, node->uuid, node->info.major, node->info.minor);
                return 0;
	}

	return 1;
}

static int _emit_areas_line(struct dm_task *dmt __attribute((unused)),
			    struct load_segment *seg, char *params,