2 files changed, 31 insertions, 5 deletions

diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index f5fd515..be0c0d0 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -128,6 +128,7 @@ int ft_queue_status(struct se_cmd *se_cmd)
 	struct fc_lport *lport;
 	struct fc_exch *ep;
 	size_t len;
+	int rc;
 
 	if (cmd->aborted)
 		return 0;
@@ -137,9 +138,10 @@ int ft_queue_status(struct se_cmd *se_cmd)
 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
 	fp = fc_frame_alloc(lport, len);
 	if (!fp) {
-		/* XXX shouldn't just drop it - requeue and retry? */
-		return 0;
+		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+		return -ENOMEM;
 	}
+
 	fcp = fc_frame_payload_get(fp, len);
 	memset(fcp, 0, len);
 	fcp->resp.fr_status = se_cmd->scsi_status;
@@ -170,7 +172,18 @@ int ft_queue_status(struct se_cmd *se_cmd)
 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
 
-	lport->tt.seq_send(lport, cmd->seq, fp);
+	rc = lport->tt.seq_send(lport, cmd->seq, fp);
+	if (rc) {
+		pr_info_ratelimited("%s: Failed to send response frame %p, "
+				    "xid <0x%x>\n", __func__, fp, ep->xid);
+		/*
+		 * Generate a TASK_SET_FULL status to notify the initiator
+		 * to reduce it's queue_depth after the se_cmd response has
+		 * been re-queued by target-core.
+		 */
+		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+		return -ENOMEM;
+	}
 	lport->tt.exch_done(cmd->seq);
 	return 0;
 }
diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c
index e415af3..97b486c 100644
--- a/drivers/target/tcm_fc/tfc_io.c
+++ b/drivers/target/tcm_fc/tfc_io.c
@@ -82,6 +82,10 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
 
 	if (cmd->aborted)
 		return 0;
+
+	if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
+		goto queue_status;
+
 	ep = fc_seq_exch(cmd->seq);
 	lport = ep->lp;
 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
@@ -178,14 +182,23 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
 			       FC_TYPE_FCP, f_ctl, fh_off);
 		error = lport->tt.seq_send(lport, seq, fp);
 		if (error) {
-			/* XXX For now, initiator will retry */
-			pr_err_ratelimited("%s: Failed to send frame %p, "
+			pr_info_ratelimited("%s: Failed to send frame %p, "
 						"xid <0x%x>, remaining %zu, "
 						"lso_max <0x%x>\n",
 						__func__, fp, ep->xid,
 						remaining, lport->lso_max);
+			/*
+			 * Go ahead and set TASK_SET_FULL status ignoring the
+			 * rest of the DataIN, and immediately attempt to
+			 * send the response via ft_queue_status() in order
+			 * to notify the initiator that it should reduce it's
+			 * per LUN queue_depth.
+			 */
+			se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+			break;
 		}
 	}
+queue_status:
 	return ft_queue_status(se_cmd);
 }