[PATCH 4.17 51/67] bsg: fix bogus EINVAL on non-data commands

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tony Battersby <tonyb@xxxxxxxxxxxxxxx>

commit 70dbcc2254fa2a9add74a122b9dac954c4736e01 upstream.

Fix a regression introduced in Linux kernel 4.17 where sending a SCSI
command that does not transfer data (such as TEST UNIT READY) via
/dev/bsg/* results in EINVAL.

Fixes: 17cb960f29c2 ("bsg: split handling of SCSI CDBs vs transport requeues")
Cc: <stable@xxxxxxxxxxxxxxx> # 4.17+
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Tony Battersby <tonyb@xxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 block/bsg.c |    2 --
 1 file changed, 2 deletions(-)

--- a/block/bsg.c
+++ b/block/bsg.c
@@ -268,8 +268,6 @@ bsg_map_hdr(struct request_queue *q, str
 	} else if (hdr->din_xfer_len) {
 		ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr->din_xferp),
 				hdr->din_xfer_len, GFP_KERNEL);
-	} else {
-		ret = blk_rq_map_user(q, rq, NULL, NULL, 0, GFP_KERNEL);
 	}
 
 	if (ret)