Commit 40b74cd3 authored by Cunyin Chang's avatar Cunyin Chang Committed by Daniel Verkamp
Browse files

iscsi: optimization of large read process. 



This patch move the spdk_iscsi_conn_handle_queued_tasks() to the main
loop of connection poller, make the logic more clear, it will also fix
one issue of hotplug:
for large read command, it has the potential risk:
one task will be split into N subtaks, when primary task return error and
try to send data in pdu, it will call spdk_iscsi_conn_handle_queued_tasks(),
the primary task is pending now, and all the subtasks will return error from
lun layer synchronous, this make the primary task return from the function
spdk_iscsi_transfer_in() after all the other subtaks, but when the N - 1 subtask
return from function spdk_iscsi_transfer_in(), it meet the condition:
primary->bytes_completed == primary->scsi.transfer_len
then it will send response pdu, after this, the primary task return from
spdk_iscsi_transfer_in(), it also meet the condition, so it will also try
to send response pdu, this will make the application run into error.

Change-Id: I72206c1ce303f5fb6bd650713742d5819a88a30f
Signed-off-by: default avatarCunyin Chang <cunyin.chang@intel.com>
Reviewed-on: https://review.gerrithub.io/370339


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 8c3fadc2

lib/iscsi/conn.c

+2 −1
Original line number Diff line number Diff line
@@ -416,7 +416,6 @@ spdk_iscsi_conn_free_pdu(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pd 
					conn->data_in_cnt--;

					spdk_iscsi_task_put(spdk_iscsi_task_get_primary(pdu->task));

				}

				spdk_iscsi_conn_handle_queued_tasks(conn);

			}

		} else if (pdu->bhs.opcode == ISCSI_OP_SCSI_RSP &&

			   pdu->task->scsi.status != SPDK_SCSI_STATUS_GOOD) {
@@ -1261,6 +1260,8 @@ spdk_iscsi_conn_execute(struct spdk_iscsi_conn *conn) 
		}

	}



	spdk_iscsi_conn_handle_queued_tasks(conn);



	if (conn_active) {

		return 1;

	}

lib/iscsi/iscsi.c

+0 −2
Original line number Diff line number Diff line
@@ -2722,12 +2722,10 @@ spdk_iscsi_transfer_in(struct spdk_iscsi_conn *conn, 
	if (task->scsi.status != SPDK_SCSI_STATUS_GOOD) {

		if (task != primary) {

			conn->data_in_cnt--;

			spdk_iscsi_conn_handle_queued_tasks(conn);

		} else {

			/* handle the case that it is a primary task which has subtasks */

			if (primary->scsi.transfer_len != task->scsi.length) {

				conn->data_in_cnt--;

				spdk_iscsi_conn_handle_queued_tasks(conn);

			}

		}