[Stgt-devel] [PATCH 07/18] iser virtualize event modify

[Pete Wyckoff]

Make event modification a transport-specific operation.  TCP
has a nice transmit flow control mechanism that relies on
checking that the socket is writeable.  RDMA cannot take
advantage of this.

Signed-off-by: Pete Wyckoff <pw at osc.edu>
---
 usr/iscsi/iscsi_tcp.c |   26 ++++++++++++++++++--------
 usr/iscsi/iscsid.c    |   22 ++++++++++++----------
 usr/iscsi/transport.h |    1 +
 3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/usr/iscsi/iscsi_tcp.c b/usr/iscsi/iscsi_tcp.c
index 0c35aa5..c775594 100644
--- a/usr/iscsi/iscsi_tcp.c
+++ b/usr/iscsi/iscsi_tcp.c
@@ -232,13 +232,23 @@ static int iscsi_tcp_show(int ep, char *buf, int rest)
 	return total > 0 ? total : 0;
 }
 
+void iscsi_event_modify(int fd, int events)
+{
+	int ret;
+
+	ret = tgt_event_modify(fd, events);
+	if (ret)
+		eprintf("tgt_event_modify failed\n");
+}
+
 struct iscsi_transport iscsi_tcp = {
-	.name		= "iscsi",
-	.rdma		= 0,
-	.ep_init	= iscsi_tcp_init,
-	.ep_read	= iscsi_tcp_read,
-	.ep_write_begin	= iscsi_tcp_write_begin,
-	.ep_write_end	= iscsi_tcp_write_end,
-	.ep_close	= iscsi_tcp_close,
-	.ep_show	= iscsi_tcp_show,
+	.name			= "iscsi",
+	.rdma			= 0,
+	.ep_init		= iscsi_tcp_init,
+	.ep_read		= iscsi_tcp_read,
+	.ep_write_begin		= iscsi_tcp_write_begin,
+	.ep_write_end		= iscsi_tcp_write_end,
+	.ep_close		= iscsi_tcp_close,
+	.ep_show		= iscsi_tcp_show,
+	.ep_event_modify	= iscsi_event_modify,
 };
diff --git a/usr/iscsi/iscsid.c b/usr/iscsi/iscsid.c
index 4b4e35f..85d4c95 100644
--- a/usr/iscsi/iscsid.c
+++ b/usr/iscsi/iscsid.c
@@ -1041,7 +1041,7 @@ static int iscsi_scsi_cmd_done(uint64_t nid, int result, struct scsi_cmd *scmd)
 	}
 
 	list_add_tail(&task->c_list, &task->conn->tx_clist);
-	tgt_event_modify(task->conn->fd, EPOLLIN | EPOLLOUT);
+	task->conn->tp->ep_event_modify(task->conn->fd, EPOLLIN | EPOLLOUT);
 
 	return 0;
 }
@@ -1165,13 +1165,13 @@ static int iscsi_scsi_cmd_execute(struct iscsi_task *task)
 	if (rw && task->r2t_count) {
 		if (!task->unsol_count) {
 			list_add_tail(&task->c_list, &task->conn->tx_clist);
-			tgt_event_modify(conn->fd, EPOLLIN | EPOLLOUT);
+			conn->tp->ep_event_modify(conn->fd, EPOLLIN | EPOLLOUT);
 		}
 		return err;
 	}
 
 	task->offset = 0;  /* for use as transmit pointer for data-ins */
-	tgt_event_modify(conn->fd, EPOLLIN);
+	conn->tp->ep_event_modify(conn->fd, EPOLLIN);
 	err = iscsi_target_cmd_queue(task);
 	return err;
 }
@@ -1201,7 +1201,7 @@ static int iscsi_tm_done(struct mgmt_req *mreq)
 		break;
 	}
 	list_add_tail(&task->c_list, &task->conn->tx_clist);
-	tgt_event_modify(task->conn->fd, EPOLLIN | EPOLLOUT);
+	task->conn->tp->ep_event_modify(task->conn->fd, EPOLLIN | EPOLLOUT);
 	return 0;
 }
 
@@ -1257,7 +1257,8 @@ static int iscsi_task_execute(struct iscsi_task *task)
 	case ISCSI_OP_NOOP_OUT:
 	case ISCSI_OP_LOGOUT:
 		list_add_tail(&task->c_list, &task->conn->tx_clist);
-		tgt_event_modify(task->conn->fd, EPOLLIN | EPOLLOUT);
+		task->conn->tp->ep_event_modify(task->conn->fd,
+						EPOLLIN | EPOLLOUT);
 		break;
 	case ISCSI_OP_SCSI_CMD:
 		/* convenient directionality for our internal use */
@@ -1277,7 +1278,8 @@ static int iscsi_task_execute(struct iscsi_task *task)
 		err = iscsi_tm_execute(task);
 		if (err) {
 			list_add_tail(&task->c_list, &task->conn->tx_clist);
-			tgt_event_modify(task->conn->fd, EPOLLIN | EPOLLOUT);
+			task->conn->tp->ep_event_modify(task->conn->fd,
+							EPOLLIN | EPOLLOUT);
 		}
 		break;
 	case ISCSI_OP_TEXT:
@@ -1721,7 +1723,7 @@ static int iscsi_task_tx_start(struct iscsi_connection *conn)
 
 nodata:
 	dprintf("no more data\n");
-	tgt_event_modify(conn->fd, EPOLLIN);
+	conn->tp->ep_event_modify(conn->fd, EPOLLIN);
 	return -EAGAIN;
 }
 
@@ -1885,7 +1887,7 @@ again:
 			conn_read_pdu(conn);
 	} else {
 		conn_write_pdu(conn);
-		tgt_event_modify(fd, EPOLLOUT);
+		conn->tp->ep_event_modify(fd, EPOLLOUT);
 		ret = cmnd_execute(conn);
 		if (ret)
 			conn->state = STATE_CLOSE;
@@ -2029,7 +2031,7 @@ static void iscsi_tx_handler(int fd, struct iscsi_connection *conn)
 		else {
 			conn->state = STATE_SCSI;
 			conn_read_pdu(conn);
-			tgt_event_modify(fd, EPOLLIN);
+			conn->tp->ep_event_modify(fd, EPOLLIN);
 		}
 		break;
 	case STATE_EXIT:
@@ -2040,7 +2042,7 @@ static void iscsi_tx_handler(int fd, struct iscsi_connection *conn)
 		break;
 	default:
 		conn_read_pdu(conn);
-		tgt_event_modify(fd, EPOLLIN);
+		conn->tp->ep_event_modify(fd, EPOLLIN);
 		break;
 	}
 }
diff --git a/usr/iscsi/transport.h b/usr/iscsi/transport.h
index ec34bb0..9660396 100644
--- a/usr/iscsi/transport.h
+++ b/usr/iscsi/transport.h
@@ -11,6 +11,7 @@ struct iscsi_transport {
 	void (*ep_write_end)(int ep);
 	size_t (*ep_close) (int ep);
 	int (*ep_show) (int ep, char *buf, int rest);
+	void (*ep_event_modify) (int ep, int events);
 };
 
 extern struct iscsi_transport iscsi_tcp;
-- 
1.5.2.5