Commit c909085b authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm ioctl: filter the returned values according to name or uuid prefix 



If we set non-empty param->name or param->uuid on the DM_LIST_DEVICES_CMD
ioctl, the set values are considered filter prefixes. The ioctl will only
return entries with matching name or uuid prefix.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 8b638081

drivers/md/dm-ioctl.c

+28 −0
Original line number Diff line number Diff line
@@ -540,6 +540,30 @@ static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, 
	return ((void *) param) + param->data_start;

}



static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)

{

	const char *val;

	size_t val_len, pfx_len;



	val = hc->name;

	val_len = strlen(val);

	pfx_len = strnlen(pfx_name, DM_NAME_LEN);

	if (pfx_len > val_len)

		return false;

	if (memcmp(val, pfx_name, pfx_len))

		return false;



	val = hc->uuid ? hc->uuid : "";

	val_len = strlen(val);

	pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);

	if (pfx_len > val_len)

		return false;

	if (memcmp(val, pfx_uuid, pfx_len))

		return false;



	return true;

}



static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)

{

	struct rb_node *n;
@@ -557,6 +581,8 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_ 
	 */

	for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {

		hc = container_of(n, struct hash_cell, name_node);

		if (!filter_device(hc, param->name, param->uuid))

			continue;

		needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);

		needed += align_val(sizeof(uint32_t) * 2);

		if (param->flags & DM_UUID_FLAG && hc->uuid)
@@ -581,6 +607,8 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_ 
	for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {

		void *uuid_ptr;

		hc = container_of(n, struct hash_cell, name_node);

		if (!filter_device(hc, param->name, param->uuid))

			continue;

		if (old_nl)

			old_nl->next = (uint32_t) ((void *) nl -

						   (void *) old_nl);