drbd: fix NULL pointer deref in blk_add_request_payload
Discards don't have any payload.
But the scsi layer still expects a bio_vec it can use internally,
see sd_setup_discard_cmnd() and blk_add_request_payload().
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index b6c8aaf..5b17ec8 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1337,8 +1337,11 @@
return 0;
}
+ /* Discards don't have any payload.
+ * But the scsi layer still expects a bio_vec it can use internally,
+ * see sd_setup_discard_cmnd() and blk_add_request_payload(). */
if (peer_req->flags & EE_IS_TRIM)
- nr_pages = 0; /* discards don't have any payload. */
+ nr_pages = 1;
/* In most cases, we will only need one bio. But in case the lower
* level restrictions happen to be different at this offset on this