dm: export name and uuid

This patch adds a function to obtain a copy of a mapped device's name and uuid.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 499f537..8b3c7cd 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -188,6 +188,7 @@
  * Info functions.
  */
 const char *dm_device_name(struct mapped_device *md);
+int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
 struct gendisk *dm_disk(struct mapped_device *md);
 int dm_suspended(struct mapped_device *md);
 int dm_noflush_suspending(struct dm_target *ti);