iscsi-target: Convert to use target_put_session + sess_kref

This patch converts iscsi-target session code to use se_sess->sess_kref
counting for iscsi session shutdown.  The following cases include:

*) last iscsit_close_connection() shutdown path to invoke close session
*) iscsit_logout_post_handler_closesession() for explict logout
*) iscsit_free_session() caller for explict shutdown

It also moves iscsit_stop_session() call from lio_tpg_close_session()
into lio_tpg_shutdown_session() TFO callbacks to invoke an explict
shutdown, and also changes iscsi_check_for_session_reinstatement()
login code to use se_sess->sess_kref.

(v2: Make iscsit_handle_time2retain_timeout() use target_put_session)

Cc: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

4 files changed, 9 insertions, 9 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index c3ef2f6f3740..d3b54ecbfcda 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4168,7 +4168,7 @@ int iscsit_close_connection(
         if (!atomic_read(&sess->session_reinstatement) &&
              atomic_read(&sess->session_fall_back_to_erl0)) {
                 spin_unlock_bh(&sess->conn_lock);
-                iscsit_close_session(sess);
+                target_put_session(sess->se_sess);
 
                 return 0;
         } else if (atomic_read(&sess->session_logout)) {
@@ -4289,7 +4289,7 @@ static void iscsit_logout_post_handler_closesession(
         iscsit_dec_conn_usage_count(conn);
         iscsit_stop_session(sess, 1, 1);
         iscsit_dec_session_usage_count(sess);
-        iscsit_close_session(sess);
+        target_put_session(sess->se_sess);
 }
 
 static void iscsit_logout_post_handler_samecid(
@@ -4455,7 +4455,7 @@ int iscsit_free_session(struct iscsi_session *sess)
         } else
                 spin_unlock_bh(&sess->conn_lock);
 
-        iscsit_close_session(sess);
+        target_put_session(sess->se_sess);
         return 0;
 }
 
diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index dcef63bf5f9d..1174f74f4fbc 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1698,8 +1698,8 @@ static int lio_tpg_shutdown_session(struct se_session *se_sess)
         atomic_set(&sess->session_reinstatement, 1);
         spin_unlock(&sess->conn_lock);
 
-        iscsit_inc_session_usage_count(sess);
         iscsit_stop_time2retain_timer(sess);
+        iscsit_stop_session(sess, 1, 1);
 
         return 1;
 }
@@ -1715,8 +1715,6 @@ static void lio_tpg_close_session(struct se_session *se_sess)
          * If the iSCSI Session for the iSCSI Initiator Node exists,
          * forcefully shutdown the iSCSI NEXUS.
          */
-        iscsit_stop_session(sess, 1, 1);
-        iscsit_dec_session_usage_count(sess);
         iscsit_close_session(sess);
 }
 
diff --git a/drivers/target/iscsi/iscsi_target_erl0.c b/drivers/target/iscsi/iscsi_target_erl0.c
index 478451167b62..1ab0560b0924 100644
--- a/drivers/target/iscsi/iscsi_target_erl0.c
+++ b/drivers/target/iscsi/iscsi_target_erl0.c
@@ -783,7 +783,7 @@ static void iscsit_handle_time2retain_timeout(unsigned long data)
         }
 
         spin_unlock_bh(&se_tpg->session_lock);
-        iscsit_close_session(sess);
+        target_put_session(sess->se_sess);
 }
 
 extern void iscsit_start_time2retain_handler(struct iscsi_session *sess)
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 38cb7ce8469e..18cffff9b456 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -180,14 +180,16 @@ int iscsi_check_for_session_reinstatement(struct iscsi_conn *conn)
         if (sess->session_state == TARG_SESS_STATE_FAILED) {
                 spin_unlock_bh(&sess->conn_lock);
                 iscsit_dec_session_usage_count(sess);
-                return iscsit_close_session(sess);
+                target_put_session(sess->se_sess);
+                return 0;
         }
         spin_unlock_bh(&sess->conn_lock);
 
         iscsit_stop_session(sess, 1, 1);
         iscsit_dec_session_usage_count(sess);
 
-        return iscsit_close_session(sess);
+        target_put_session(sess->se_sess);
+        return 0;
 }
 
 static void iscsi_login_set_conn_values(