[PATCH 3.18 071/183] iscsi,iser-target: Initiate termination only once

Greg Kroah-Hartman
2015-01-25T18:51:28Z

From: Sagi Grimberg <sagig@mellanox.com>

commit 954f23722b5753305be490330cf2680b7a25f4a3 upstream.

Since commit 0fc4ea701fcf ("Target/iser: Don't put isert_conn inside
disconnected handler") we put the conn kref in isert_wait_conn, so we
need .wait_conn to be invoked also in the error path.

Introduce call to isert_conn_terminate (called under lock)
which transitions the connection state to TERMINATING and calls
rdma_disconnect. If the state is already teminating, just bail
out back (temination started).

Also, make sure to destroy the connection when getting a connect
error event if didn't get to connected (state UP). Same for the
handling of REJECTED and UNREACHABLE cma events.

Squashed:

iscsi-target: Add call to wait_conn in establishment error flow

Reported-by: Slava Shwartsman <valyushash@gmail.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/ulp/isert/ib_isert.c | 84 ++++++++++++++++++------------
drivers/infiniband/ulp/isert/ib_isert.h | 1
drivers/target/iscsi/iscsi_target_login.c | 3 +
3 files changed, 54 insertions(+), 34 deletions(-)

--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -777,6 +777,33 @@ isert_put_conn(struct isert_conn *isert_
kref_put(&isert_conn->conn_kref, isert_release_conn_kref);
}

+/**
+ * isert_conn_terminate() - Initiate connection termination
+ * @isert_conn: isert connection struct
+ *
+ * Notes:
+ * In case the connection state is UP, move state
+ * to TEMINATING and start teardown sequence (rdma_disconnect).
+ *
+ * This routine must be called with conn_mutex held. Thus it is
+ * safe to call multiple times.
+ */
+static void
+isert_conn_terminate(struct isert_conn *isert_conn)
+{
+ int err;
+
+ if (isert_conn->state == ISER_CONN_UP) {
+ isert_conn->state = ISER_CONN_TERMINATING;
+ pr_info("Terminating conn %p state %d\n",
+ isert_conn, isert_conn->state);
+ err = rdma_disconnect(isert_conn->conn_cm_id);
+ if (err)
+ pr_warn("Failed rdma_disconnect isert_conn %p\n",
+ isert_conn);
+ }
+}
+
static void
isert_disconnect_work(struct work_struct *work)
{
@@ -785,33 +812,15 @@ isert_disconnect_work(struct work_struct

pr_debug("isert_disconnect_work(): >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
mutex_lock(&isert_conn->conn_mutex);
- if (isert_conn->state == ISER_CONN_UP)
- isert_conn->state = ISER_CONN_TERMINATING;
-
- if (isert_conn->post_recv_buf_count == 0 &&
- atomic_read(&isert_conn->post_send_buf_count) == 0) {
- mutex_unlock(&isert_conn->conn_mutex);
- goto wake_up;
- }
- if (!isert_conn->conn_cm_id) {
- mutex_unlock(&isert_conn->conn_mutex);
- isert_put_conn(isert_conn);
- return;
- }
-
- if (isert_conn->disconnect) {
- /* Send DREQ/DREP towards our initiator */
- rdma_disconnect(isert_conn->conn_cm_id);
- }
-
+ isert_conn_terminate(isert_conn);
mutex_unlock(&isert_conn->conn_mutex);

-wake_up:
+ pr_info("conn %p completing conn_wait\n", isert_conn);
complete(&isert_conn->conn_wait);
}

static int
-isert_disconnected_handler(struct rdma_cm_id *cma_id, bool disconnect)
+isert_disconnected_handler(struct rdma_cm_id *cma_id)
{
struct isert_conn *isert_conn;

@@ -824,18 +833,24 @@ isert_disconnected_handler(struct rdma_c

isert_conn = (struct isert_conn *)cma_id->context;

- isert_conn->disconnect = disconnect;
INIT_WORK(&isert_conn->conn_logout_work, isert_disconnect_work);
schedule_work(&isert_conn->conn_logout_work);

return 0;
}

+static void
+isert_connect_error(struct rdma_cm_id *cma_id)
+{
+ struct isert_conn *isert_conn = (struct isert_conn *)cma_id->context;
+
+ isert_put_conn(isert_conn);
+}
+
static int
isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
{
int ret = 0;
- bool disconnect = false;

pr_debug("isert_cma_handler: event %d status %d conn %p id %p\n",
event->event, event->status, cma_id->context, cma_id);
@@ -853,11 +868,14 @@ isert_cma_handler(struct rdma_cm_id *cma
case RDMA_CM_EVENT_ADDR_CHANGE: /* FALLTHRU */
case RDMA_CM_EVENT_DISCONNECTED: /* FALLTHRU */
case RDMA_CM_EVENT_DEVICE_REMOVAL: /* FALLTHRU */
- disconnect = true;
case RDMA_CM_EVENT_TIMEWAIT_EXIT: /* FALLTHRU */
- ret = isert_disconnected_handler(cma_id, disconnect);
+ ret = isert_disconnected_handler(cma_id);
break;
+ case RDMA_CM_EVENT_REJECTED: /* FALLTHRU */
+ case RDMA_CM_EVENT_UNREACHABLE: /* FALLTHRU */
case RDMA_CM_EVENT_CONNECT_ERROR:
+ isert_connect_error(cma_id);
+ break;
default:
pr_err("Unhandled RDMA CMA event: %d\n", event->event);
break;
@@ -2046,7 +2064,7 @@ isert_cq_rx_comp_err(struct isert_conn *
msleep(3000);

mutex_lock(&isert_conn->conn_mutex);
- isert_conn->state = ISER_CONN_DOWN;
+ isert_conn_terminate(isert_conn);
mutex_unlock(&isert_conn->conn_mutex);

iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
@@ -3219,10 +3237,6 @@ static void isert_wait_conn(struct iscsi
pr_debug("isert_wait_conn: Starting \n");

mutex_lock(&isert_conn->conn_mutex);
- if (isert_conn->conn_cm_id && !isert_conn->disconnect) {
- pr_debug("Calling rdma_disconnect from isert_wait_conn\n");
- rdma_disconnect(isert_conn->conn_cm_id);
- }
/*
* Only wait for conn_wait_comp_err if the isert_conn made it
* into full feature phase..
@@ -3231,13 +3245,17 @@ static void isert_wait_conn(struct iscsi
mutex_unlock(&isert_conn->conn_mutex);
return;
}
- if (isert_conn->state == ISER_CONN_UP)
- isert_conn->state = ISER_CONN_TERMINATING;
+ isert_conn_terminate(isert_conn);
mutex_unlock(&isert_conn->conn_mutex);

wait_for_completion(&isert_conn->conn_wait_comp_err);
-
wait_for_completion(&isert_conn->conn_wait);
+
+ mutex_lock(&isert_conn->conn_mutex);
+ isert_conn->state = ISER_CONN_DOWN;
+ mutex_unlock(&isert_conn->conn_mutex);
+
+ pr_info("Destroying conn %p\n", isert_conn);
isert_put_conn(isert_conn);
}

--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -150,7 +150,6 @@ struct isert_conn {
#define ISERT_COMP_BATCH_COUNT 8
int conn_comp_batch;
struct llist_head conn_comp_llist;
- bool disconnect;
};

#define ISERT_MAX_CQ 64
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -1204,6 +1204,9 @@ old_sess_out:
conn->sock = NULL;
}

+ if (conn->conn_transport->iscsit_wait_conn)
+ conn->conn_transport->iscsit_wait_conn(conn);
+
if (conn->conn_transport->iscsit_free_conn)
conn->conn_transport->iscsit_free_conn(conn);