[SCSI] iscsi_iser: convert to use the data buffer accessors

iscsi_iser: convert to use the data buffer accessors

- remove the unnecessary map_single path.

- convert to use the new accessors for the sg lists and the
parameters.

TODO: use scsi_for_each_sg().
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NErez Zilber <erezz@voltaire.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/infiniband/ulp/iser/iscsi_iser.c

@@ -210,10 +210,10 @@ iscsi_iser_ctask_xmit(struct iscsi_conn *conn,
 	int error = 0;
 
 	if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) {
-		BUG_ON(ctask->sc->request_bufflen == 0);
+		BUG_ON(scsi_bufflen(ctask->sc) == 0);
 
 		debug_scsi("cmd [itt %x total %d imm %d unsol_data %d\n",
-			   ctask->itt, ctask->sc->request_bufflen,
+			   ctask->itt, scsi_bufflen(ctask->sc),
 			   ctask->imm_count, ctask->unsol_count);
 	}
 

drivers/infiniband/ulp/iser/iser_initiator.c

@@ -351,18 +351,12 @@ int iser_send_command(struct iscsi_conn     *conn,
 	else
 		data_buf = &iser_ctask->data[ISER_DIR_OUT];
 
-	if (sc->use_sg) { /* using a scatter list */
-		data_buf->buf  = sc->request_buffer;
-		data_buf->size = sc->use_sg;
-	} else if (sc->request_bufflen) {
-		/* using a single buffer - convert it into one entry SG */
-		sg_init_one(&data_buf->sg_single,
-			    sc->request_buffer, sc->request_bufflen);
-		data_buf->buf   = &data_buf->sg_single;
-		data_buf->size  = 1;
-	}
-
-	data_buf->data_len = sc->request_bufflen;
+	if (scsi_sg_count(sc)) { /* using a scatter list */
+		data_buf->buf  = scsi_sglist(sc);
+		data_buf->size = scsi_sg_count(sc);
+	}
+
+	data_buf->data_len = scsi_bufflen(sc);
 
 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 		err = iser_prepare_read_cmd(ctask, edtl);