[SCSI] libiscsi, iser, tcp: remove recv_lock

The recv lock was defined so the iscsi layer could block
the recv path from processing IO during recovery. It
turns out iser just set a lock to that pointer which was pointless.

We now disconnect the transport connection before doing recovery
so we do not need the recv lock. For iscsi_tcp we still stop
the recv path incase older tools are being used.

This patch also has iscsi_itt_to_ctask user grab the session lock
and has the caller access the task with the lock or get a ref
to it in case the target is broken and sends a tmf success response
then sends data or a response for the command that was supposed to
be affected bty the tmf.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 16 insertions, 12 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 08edbaf89223..c02eabd383a1 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -281,9 +281,6 @@ iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
 	conn->max_recv_dlength = 128;
 
 	iser_conn = conn->dd_data;
-	/* currently this is the only field which need to be initiated */
-	rwlock_init(&iser_conn->lock);
-
 	conn->dd_data = iser_conn;
 	iser_conn->iscsi_conn = conn;
 
@@ -342,9 +339,6 @@ iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
 	ib_conn->iser_conn = iser_conn;
 	iser_conn->ib_conn  = ib_conn;
 	iser_conn_get(ib_conn);
-
-	conn->recv_lock = &iser_conn->lock;
-
 	return 0;
 }
 
@@ -355,12 +349,18 @@ iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
 	struct iser_conn *ib_conn = iser_conn->ib_conn;
 
-	iscsi_conn_stop(cls_conn, flag);
 	/*
-	 * There is no unbind event so the stop callback
-	 * must release the ref from the bind.
+	 * Userspace may have goofed up and not bound the connection or
+	 * might have only partially setup the connection.
 	 */
-	iser_conn_put(ib_conn);
+	if (ib_conn) {
+		iscsi_conn_stop(cls_conn, flag);
+		/*
+		 * There is no unbind event so the stop callback
+		 * must release the ref from the bind.
+		 */
+		iser_conn_put(ib_conn);
+	}
 	iser_conn->ib_conn = NULL;
 }
 
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index cdf48763b082..a547edeea969 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -263,8 +263,6 @@ struct iser_conn {
 struct iscsi_iser_conn {
 	struct iscsi_conn            *iscsi_conn;/* ptr to iscsi conn */
 	struct iser_conn             *ib_conn;   /* iSER IB conn      */
-
-	rwlock_t		     lock;
 };
 
 struct iscsi_iser_task {
diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index 35af60a23c61..c36083922134 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -558,7 +558,12 @@ void iser_rcv_completion(struct iser_desc *rx_desc,
 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 
 	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
+		spin_lock(&conn->iscsi_conn->session->lock);
 		task = iscsi_itt_to_ctask(conn->iscsi_conn, hdr->itt);
+		if (task)
+			__iscsi_get_task(task);
+		spin_unlock(&conn->iscsi_conn->session->lock);
+
 		if (!task)
 			iser_err("itt can't be matched to task!!! "
 				 "conn %p opcode %d itt %d\n",
@@ -568,6 +573,7 @@ void iser_rcv_completion(struct iser_desc *rx_desc,
 			iser_dbg("itt %d task %p\n",hdr->itt, task);
 			iser_task->status = ISER_TASK_STATUS_COMPLETED;
 			iser_task_rdma_finalize(iser_task);
+			iscsi_put_task(task);
 		}
 	}
 	iser_dto_buffs_release(dto);