diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index de6640ad1943..1e887c11e83d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1072,6 +1072,7 @@ static blk_status_t sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 	struct bio *bio = rq->bio;
 	u64 lba = sectors_to_logical(sdp, blk_rq_pos(rq));
 	u32 nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));
+	unsigned int nr_bytes = blk_rq_bytes(rq);
 	blk_status_t ret;
 
 	if (sdkp->device->no_write_same)
@@ -1108,7 +1109,7 @@ static blk_status_t sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 	 */
 	rq->__data_len = sdp->sector_size;
 	ret = scsi_alloc_sgtables(cmd);
-	rq->__data_len = blk_rq_bytes(rq);
+	rq->__data_len = nr_bytes;
 
 	return ret;
 }