IB/iser: Protect iser state machine with a mutex
The iser connection state lookups and transitions are not fully protected.
Some transitions are protected with a spinlock, and in some cases the
state is accessed unprotected due to specific assumptions of the flow.
Introduce a new mutex to protect the connection state access. We use a
mutex since we need to also include a scheduling operations executed
under the state lock.
Each state transition/condition and its corresponding action will be
protected with the state mutex.
The rdma_cm events handler acquires the mutex when handling connection
events. Since iser connection state can transition to DOWN
concurrently during connection establishment, we bailout from
addr/route resolution events when the state is not PENDING.
This addresses a scenario where ep_poll retries expire during CMA
connection establishment. In this case ep_disconnect is invoked while
CMA events keep coming (address/route resolution, connected, etc...).
Signed-off-by: Ariel Nahum <arieln@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index d7acd4b..3dc853c 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -632,10 +632,13 @@
msecs_to_jiffies(timeout_ms));
/* if conn establishment failed, return error code to iscsi */
- if (!rc &&
- (ib_conn->state == ISER_CONN_TERMINATING ||
- ib_conn->state == ISER_CONN_DOWN))
- rc = -1;
+ if (rc == 0) {
+ mutex_lock(&ib_conn->state_mutex);
+ if (ib_conn->state == ISER_CONN_TERMINATING ||
+ ib_conn->state == ISER_CONN_DOWN)
+ rc = -1;
+ mutex_unlock(&ib_conn->state_mutex);
+ }
iser_info("ib conn %p rc = %d\n", ib_conn, rc);
@@ -654,6 +657,7 @@
ib_conn = ep->dd_data;
iser_info("ep %p ib conn %p state %d\n", ep, ib_conn, ib_conn->state);
+ mutex_lock(&ib_conn->state_mutex);
iser_conn_terminate(ib_conn);
/*
@@ -664,7 +668,10 @@
if (ib_conn->iscsi_conn) {
INIT_WORK(&ib_conn->release_work, iser_release_work);
queue_work(release_wq, &ib_conn->release_work);
+ mutex_unlock(&ib_conn->state_mutex);
} else {
+ ib_conn->state = ISER_CONN_DOWN;
+ mutex_unlock(&ib_conn->state_mutex);
iser_conn_release(ib_conn);
}
iscsi_destroy_endpoint(ep);