Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

2 files changed, 62 insertions, 62 deletions

diff --git a/kernel/drivers/infiniband/ulp/isert/ib_isert.c b/kernel/drivers/infiniband/ulp/isert/ib_isert.c
index 8a51c3b5d..b0edb66a2 100644
--- a/kernel/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/kernel/drivers/infiniband/ulp/isert/ib_isert.c
@@ -66,6 +66,7 @@ isert_rdma_accept(struct isert_conn *isert_conn);
 struct rdma_cm_id *isert_setup_id(struct isert_np *isert_np);
 
 static void isert_release_work(struct work_struct *work);
+static void isert_wait4flush(struct isert_conn *isert_conn);
 
 static inline bool
 isert_prot_cmd(struct isert_conn *conn, struct se_cmd *cmd)
@@ -815,12 +816,31 @@ isert_put_conn(struct isert_conn *isert_conn)
 	kref_put(&isert_conn->kref, isert_release_kref);
 }
 
+static void
+isert_handle_unbound_conn(struct isert_conn *isert_conn)
+{
+	struct isert_np *isert_np = isert_conn->cm_id->context;
+
+	mutex_lock(&isert_np->mutex);
+	if (!list_empty(&isert_conn->node)) {
+		/*
+		 * This means iscsi doesn't know this connection
+		 * so schedule a cleanup ourselves
+		 */
+		list_del_init(&isert_conn->node);
+		isert_put_conn(isert_conn);
+		complete(&isert_conn->wait);
+		queue_work(isert_release_wq, &isert_conn->release_work);
+	}
+	mutex_unlock(&isert_np->mutex);
+}
+
 /**
  * isert_conn_terminate() - Initiate connection termination
  * @isert_conn: isert connection struct
  *
  * Notes:
- * In case the connection state is FULL_FEATURE, move state
+ * In case the connection state is BOUND, move state
  * to TEMINATING and start teardown sequence (rdma_disconnect).
  * In case the connection state is UP, complete flush as well.
  *
@@ -832,23 +852,19 @@ isert_conn_terminate(struct isert_conn *isert_conn)
 {
 	int err;
 
-	switch (isert_conn->state) {
-	case ISER_CONN_TERMINATING:
-		break;
-	case ISER_CONN_UP:
-	case ISER_CONN_FULL_FEATURE: /* FALLTHRU */
-		isert_info("Terminating conn %p state %d\n",
-			   isert_conn, isert_conn->state);
-		isert_conn->state = ISER_CONN_TERMINATING;
-		err = rdma_disconnect(isert_conn->cm_id);
-		if (err)
-			isert_warn("Failed rdma_disconnect isert_conn %p\n",
-				   isert_conn);
-		break;
-	default:
-		isert_warn("conn %p teminating in state %d\n",
-			   isert_conn, isert_conn->state);
-	}
+	if (isert_conn->state >= ISER_CONN_TERMINATING)
+		return;
+
+	isert_info("Terminating conn %p state %d\n",
+		   isert_conn, isert_conn->state);
+	isert_conn->state = ISER_CONN_TERMINATING;
+	err = rdma_disconnect(isert_conn->cm_id);
+	if (err)
+		isert_warn("Failed rdma_disconnect isert_conn %p\n",
+			   isert_conn);
+
+	isert_info("conn %p completing wait\n", isert_conn);
+	complete(&isert_conn->wait);
 }
 
 static int
@@ -882,35 +898,27 @@ static int
 isert_disconnected_handler(struct rdma_cm_id *cma_id,
 			   enum rdma_cm_event_type event)
 {
-	struct isert_np *isert_np = cma_id->context;
-	struct isert_conn *isert_conn;
-	bool terminating = false;
-
-	if (isert_np->cm_id == cma_id)
-		return isert_np_cma_handler(cma_id->context, event);
-
-	isert_conn = cma_id->qp->qp_context;
+	struct isert_conn *isert_conn = cma_id->qp->qp_context;
 
 	mutex_lock(&isert_conn->mutex);
-	terminating = (isert_conn->state == ISER_CONN_TERMINATING);
-	isert_conn_terminate(isert_conn);
-	mutex_unlock(&isert_conn->mutex);
-
-	isert_info("conn %p completing wait\n", isert_conn);
-	complete(&isert_conn->wait);
-
-	if (terminating)
-		goto out;
-
-	mutex_lock(&isert_np->mutex);
-	if (!list_empty(&isert_conn->node)) {
-		list_del_init(&isert_conn->node);
-		isert_put_conn(isert_conn);
-		queue_work(isert_release_wq, &isert_conn->release_work);
+	switch (isert_conn->state) {
+	case ISER_CONN_TERMINATING:
+		break;
+	case ISER_CONN_UP:
+		isert_conn_terminate(isert_conn);
+		isert_wait4flush(isert_conn);
+		isert_handle_unbound_conn(isert_conn);
+		break;
+	case ISER_CONN_BOUND:
+	case ISER_CONN_FULL_FEATURE: /* FALLTHRU */
+		iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
+		break;
+	default:
+		isert_warn("conn %p teminating in state %d\n",
+			   isert_conn, isert_conn->state);
 	}
-	mutex_unlock(&isert_np->mutex);
+	mutex_unlock(&isert_conn->mutex);
 
-out:
 	return 0;
 }
 
@@ -929,12 +937,16 @@ isert_connect_error(struct rdma_cm_id *cma_id)
 static int
 isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 {
+	struct isert_np *isert_np = cma_id->context;
 	int ret = 0;
 
 	isert_info("%s (%d): status %d id %p np %p\n",
 		   rdma_event_msg(event->event), event->event,
 		   event->status, cma_id, cma_id->context);
 
+	if (isert_np->cm_id == cma_id)
+		return isert_np_cma_handler(cma_id->context, event->event);
+
 	switch (event->event) {
 	case RDMA_CM_EVENT_CONNECT_REQUEST:
 		ret = isert_connect_request(cma_id, event);
@@ -980,13 +992,10 @@ isert_post_recvm(struct isert_conn *isert_conn, u32 count)
 	rx_wr--;
 	rx_wr->next = NULL; /* mark end of work requests list */
 
-	isert_conn->post_recv_buf_count += count;
 	ret = ib_post_recv(isert_conn->qp, isert_conn->rx_wr,
 			   &rx_wr_failed);
-	if (ret) {
+	if (ret)
 		isert_err("ib_post_recv() failed with ret: %d\n", ret);
-		isert_conn->post_recv_buf_count -= count;
-	}
 
 	return ret;
 }
@@ -1002,12 +1011,9 @@ isert_post_recv(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc)
 	rx_wr.num_sge = 1;
 	rx_wr.next = NULL;
 
-	isert_conn->post_recv_buf_count++;
 	ret = ib_post_recv(isert_conn->qp, &rx_wr, &rx_wr_failed);
-	if (ret) {
+	if (ret)
 		isert_err("ib_post_recv() failed with ret: %d\n", ret);
-		isert_conn->post_recv_buf_count--;
-	}
 
 	return ret;
 }
@@ -1120,12 +1126,9 @@ isert_rdma_post_recvl(struct isert_conn *isert_conn)
 	rx_wr.sg_list = &sge;
 	rx_wr.num_sge = 1;
 
-	isert_conn->post_recv_buf_count++;
 	ret = ib_post_recv(isert_conn->qp, &rx_wr, &rx_wr_fail);
-	if (ret) {
+	if (ret)
 		isert_err("ib_post_recv() failed: %d\n", ret);
-		isert_conn->post_recv_buf_count--;
-	}
 
 	return ret;
 }
@@ -1620,7 +1623,6 @@ isert_rcv_completion(struct iser_rx_desc *desc,
 	ib_dma_sync_single_for_device(ib_dev, rx_dma, rx_buflen,
 				      DMA_FROM_DEVICE);
 
-	isert_conn->post_recv_buf_count--;
 }
 
 static int
@@ -2035,7 +2037,8 @@ is_isert_tx_desc(struct isert_conn *isert_conn, void *wr_id)
 	void *start = isert_conn->rx_descs;
 	int len = ISERT_QP_MAX_RECV_DTOS * sizeof(*isert_conn->rx_descs);
 
-	if (wr_id >= start && wr_id < start + len)
+	if ((wr_id >= start && wr_id < start + len) ||
+	    (wr_id == isert_conn->login_req_buf))
 		return false;
 
 	return true;
@@ -2059,10 +2062,6 @@ isert_cq_comp_err(struct isert_conn *isert_conn, struct ib_wc *wc)
 			isert_unmap_tx_desc(desc, ib_dev);
 		else
 			isert_completion_put(desc, isert_cmd, ib_dev, true);
-	} else {
-		isert_conn->post_recv_buf_count--;
-		if (!isert_conn->post_recv_buf_count)
-			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
 	}
 }
 
@@ -3193,6 +3192,7 @@ accept_wait:
 
 	conn->context = isert_conn;
 	isert_conn->conn = conn;
+	isert_conn->state = ISER_CONN_BOUND;
 
 	isert_set_conn_info(np, conn, isert_conn);
 
diff --git a/kernel/drivers/infiniband/ulp/isert/ib_isert.h b/kernel/drivers/infiniband/ulp/isert/ib_isert.h
index 3d7fbc47c..1874d21da 100644
--- a/kernel/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/kernel/drivers/infiniband/ulp/isert/ib_isert.h
@@ -50,6 +50,7 @@ enum iser_ib_op_code {
 enum iser_conn_state {
 	ISER_CONN_INIT,
 	ISER_CONN_UP,
+	ISER_CONN_BOUND,
 	ISER_CONN_FULL_FEATURE,
 	ISER_CONN_TERMINATING,
 	ISER_CONN_DOWN,
@@ -144,7 +145,6 @@ struct isert_device;
 
 struct isert_conn {
 	enum iser_conn_state	state;
-	int			post_recv_buf_count;
 	u32			responder_resources;
 	u32			initiator_depth;
 	bool			pi_support;