iser-target: Fix session reset bug with RDMA_CM_EVENT_DISCONNECTED

This patch addresses a bug where RDMA_CM_EVENT_DISCONNECTED may occur
before the connection shutdown has been completed by rx/tx threads,
that causes isert_free_conn() to wait indefinately on ->conn_wait.

This patch allows isert_disconnect_work code to invoke rdma_disconnect
when isert_disconnect_work() process context is started by client
session reset before isert_free_conn() code has been reached.

It also adds isert_conn->conn_mutex protection for ->state within
isert_disconnect_work(), isert_cq_comp_err() and isert_free_conn()
code, along with isert_check_state() for wait_event usage.

(v2: Add explicit iscsit_cause_connection_reinstatement call
     during isert_disconnect_work() to force conn reset)

Cc: stable@vger.kernel.org  # 3.10+
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_erl0.c b/drivers/target/iscsi/iscsi_target_erl0.c
index 8f074e0b6099..3722f8dffa68 100644
--- a/drivers/target/iscsi/iscsi_target_erl0.c
+++ b/drivers/target/iscsi/iscsi_target_erl0.c
@@ -908,6 +908,7 @@ void iscsit_cause_connection_reinstatement(struct iscsi_conn *conn, int sleep)
         wait_for_completion(&conn->conn_wait_comp);
         complete(&conn->conn_post_wait_comp);
 }
+EXPORT_SYMBOL(iscsit_cause_connection_reinstatement);
 
 void iscsit_fall_back_to_erl0(struct iscsi_session *sess)
 {