dm thin metadata: add dm_thin_remove_range()

Removes a range of blocks from the btree.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index f11f140..a938bab 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -167,6 +167,8 @@
 			 dm_block_t data_block);
 
 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block);
+int dm_thin_remove_range(struct dm_thin_device *td,
+			 dm_block_t begin, dm_block_t end);
 
 /*
  * Queries.