---
 drivers/md/dm-thin.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Index: linux/drivers/md/dm-thin.c
===================================================================
--- linux.orig/drivers/md/dm-thin.c
+++ linux/drivers/md/dm-thin.c
@@ -221,6 +221,7 @@ struct pool_c {
 struct thin_c {
 	struct dm_dev *pool_dev;
 	struct dm_dev *origin_dev;
+	sector_t origin_dev_size;
 	dm_thin_id dev_id;
 
 	struct pool *pool;
@@ -1216,7 +1217,9 @@ static void process_bio(struct thin_c *t
 		break;
 
 	case -ENODATA:
-		if (bio_data_dir(bio) == READ && tc->origin_dev) {
+// AGK FIXME Must also deal with overlap/splitting somewhere?
+		if (bio_data_dir(bio) == READ && tc->origin_dev &&
+		    bio->bi_sector + bio->bi_size > tc->origin_dev_size) {
 			inc_all_io_entry(pool, bio);
 			cell_defer_no_holder(tc, cell);
 
@@ -2744,6 +2747,7 @@ static int thin_ctr(struct dm_target *ti
 			goto bad_origin_dev;
 		}
 		tc->origin_dev = origin_dev;
+		tc->origin_dev_size = i_size_read(origin_dev->bdev->bd_inode) >> SECTOR_SHIFT;
 	}
 
 	r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);