rsxx: Adapter address space sanity check.

Adding a sanity check to guarentee that DMAs outside of the device's
address space will be errored out right away.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/rsxx/dev.c b/drivers/block/rsxx/dev.c
index a092f58..d7af441 100644
--- a/drivers/block/rsxx/dev.c
+++ b/drivers/block/rsxx/dev.c
@@ -174,6 +174,9 @@
 	if (!card)
 		goto req_err;
 
+	if (bio->bi_sector + (bio->bi_size >> 9) > get_capacity(card->gendisk))
+		goto req_err;
+
 	if (unlikely(card->halt)) {
 		st = -EFAULT;
 		goto req_err;