iscsi-target: Propigate queue_data_in + queue_status errors

This patch changes iscsi-target to propagate iscsit_transport
->iscsit_queue_data_in() and ->iscsit_queue_status() callback
errors, back up into target-core.

This allows target-core to retry failed iscsit_transport
callbacks using internal queue-full logic.
Reported-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com>
Tested-by: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Reported-by: Steve Wise <swise@opengridcomputing.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target.c

@@ -485,8 +485,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *);
 
 int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
 {
-	iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
-	return 0;
+	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
 }
 EXPORT_SYMBOL(iscsit_queue_rsp);
 

drivers/target/iscsi/iscsi_target_configfs.c

@@ -1398,11 +1398,10 @@ static u32 lio_sess_get_initiator_sid(
 static int lio_queue_data_in(struct se_cmd *se_cmd)
 {
 	struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+	struct iscsi_conn *conn = cmd->conn;
 
 	cmd->i_state = ISTATE_SEND_DATAIN;
-	cmd->conn->conn_transport->iscsit_queue_data_in(cmd->conn, cmd);
-
-	return 0;
+	return conn->conn_transport->iscsit_queue_data_in(conn, cmd);
 }
 
 static int lio_write_pending(struct se_cmd *se_cmd)
@@ -1431,16 +1430,14 @@ static int lio_write_pending_status(struct se_cmd *se_cmd)
 static int lio_queue_status(struct se_cmd *se_cmd)
 {
 	struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+	struct iscsi_conn *conn = cmd->conn;
 
 	cmd->i_state = ISTATE_SEND_STATUS;
 
 	if (cmd->se_cmd.scsi_status || cmd->sense_reason) {
-		iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
-		return 0;
+		return iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 	}
-	cmd->conn->conn_transport->iscsit_queue_status(cmd->conn, cmd);
-
-	return 0;
+	return conn->conn_transport->iscsit_queue_status(conn, cmd);
 }
 
 static void lio_queue_tm_rsp(struct se_cmd *se_cmd)

drivers/target/iscsi/iscsi_target_util.c

@@ -567,7 +567,7 @@ static void iscsit_remove_cmd_from_immediate_queue(
 	}
 }
 
-void iscsit_add_cmd_to_response_queue(
+int iscsit_add_cmd_to_response_queue(
 	struct iscsi_cmd *cmd,
 	struct iscsi_conn *conn,
 	u8 state)
@@ -578,7 +578,7 @@ void iscsit_add_cmd_to_response_queue(
 	if (!qr) {
 		pr_err("Unable to allocate memory for"
 			" struct iscsi_queue_req\n");
-		return;
+		return -ENOMEM;
 	}
 	INIT_LIST_HEAD(&qr->qr_list);
 	qr->cmd = cmd;
@@ -590,6 +590,7 @@ void iscsit_add_cmd_to_response_queue(
 	spin_unlock_bh(&conn->response_queue_lock);
 
 	wake_up(&conn->queues_wq);
+	return 0;
 }
 
 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)

drivers/target/iscsi/iscsi_target_util.h

@@ -31,7 +31,7 @@ extern int iscsit_find_cmd_for_recovery(struct iscsi_session *, struct iscsi_cmd
 			struct iscsi_conn_recovery **, itt_t);
 extern void iscsit_add_cmd_to_immediate_queue(struct iscsi_cmd *, struct iscsi_conn *, u8);
 extern struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *);
-extern void iscsit_add_cmd_to_response_queue(struct iscsi_cmd *, struct iscsi_conn *, u8);
+extern int iscsit_add_cmd_to_response_queue(struct iscsi_cmd *, struct iscsi_conn *, u8);
 extern struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *);
 extern void iscsit_remove_cmd_from_tx_queues(struct iscsi_cmd *, struct iscsi_conn *);
 extern bool iscsit_conn_all_queues_empty(struct iscsi_conn *);