From f9b9d824c6c6cb70b5962a0a48f8ce8d41676dc7 Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Fri, 6 Mar 2009 19:04:48 +0000
Subject: [PATCH] Session and connection reinstation fixes for cases when they
 are shutting down and request for reinstation comes.

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@692 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 iscsi-scst/kernel/conn.c    |  3 ++-
 iscsi-scst/kernel/iscsi.h   |  6 ++++--
 iscsi-scst/kernel/nthread.c | 25 +++++++++++++++++++------
 iscsi-scst/kernel/session.c |  6 ++++--
 4 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/iscsi-scst/kernel/conn.c b/iscsi-scst/kernel/conn.c
index 40e05db89..238464fbc 100644
--- a/iscsi-scst/kernel/conn.c
+++ b/iscsi-scst/kernel/conn.c
@@ -394,6 +394,7 @@ int conn_free(struct iscsi_conn *conn)
 	sBUG_ON(!list_empty(&conn->write_list));
 	sBUG_ON(!list_empty(&conn->written_list));
 	sBUG_ON(conn->conn_reinst_successor != NULL);
+	sBUG_ON(!conn->conn_shutting_down);
 
 	if (conn->conn_reinstating) {
 		struct iscsi_conn *c;
@@ -504,7 +505,7 @@ int conn_add(struct iscsi_session *session, struct iscsi_kern_conn_info *info)
 	bool reinstatement = false;
 
 	conn = conn_lookup(session, info->cid);
-	if (conn != NULL) {
+	if ((conn != NULL) && !conn->conn_shutting_down) {
 		/* conn reinstatement */
 		reinstatement = true;
 	} else if (!list_empty(&session->conn_list)) {
diff --git a/iscsi-scst/kernel/iscsi.h b/iscsi-scst/kernel/iscsi.h
index 6049cf787..a57fc6242 100644
--- a/iscsi-scst/kernel/iscsi.h
+++ b/iscsi-scst/kernel/iscsi.h
@@ -114,9 +114,10 @@ struct iscsi_session {
 
 	struct list_head session_list_entry;
 
-	/* All don't need any protection */
+	/* All protected by target_mutex, where necessary */
 	struct iscsi_session *sess_reinst_successor;
 	unsigned int sess_reinstating:1;
+	unsigned int sess_shutting_down:1;
 
 	/* All don't need any protection */
 	char *initiator_name;
@@ -218,9 +219,10 @@ struct iscsi_conn {
 
 	struct list_head conn_list_entry; /* list entry in session conn_list */
 
-	/* All don't need any protection */
+	/* All protected by target_mutex, where necessary */
 	struct iscsi_conn *conn_reinst_successor;
 	unsigned int conn_reinstating:1;
+	unsigned int conn_shutting_down:1;
 
 	struct completion ready_to_free;
 
diff --git a/iscsi-scst/kernel/nthread.c b/iscsi-scst/kernel/nthread.c
index 5a629d538..98336ec02 100644
--- a/iscsi-scst/kernel/nthread.c
+++ b/iscsi-scst/kernel/nthread.c
@@ -358,10 +358,11 @@ static void close_conn(struct iscsi_conn *conn)
 {
 	struct iscsi_session *session = conn->session;
 	struct iscsi_target *target = conn->target;
+	struct iscsi_conn *c;
 	typeof(jiffies) start_waiting = jiffies;
 	typeof(jiffies) shut_start_waiting = start_waiting;
 	bool pending_reported = 0, wait_expired = 0, shut_expired = 0;
-	bool free_sess;
+	bool reinst;
 
 #define CONN_PENDING_TIMEOUT	((typeof(jiffies))10*HZ)
 #define CONN_WAIT_TIMEOUT	((typeof(jiffies))10*HZ)
@@ -385,7 +386,22 @@ static void close_conn(struct iscsi_conn *conn)
 			RCV_SHUTDOWN|SEND_SHUTDOWN);
 	}
 
-	if (conn->conn_reinst_successor != NULL) {
+	mutex_lock(&session->target->target_mutex);
+
+	conn->conn_shutting_down = 1;
+	reinst = (conn->conn_reinst_successor != NULL);
+
+	session->sess_shutting_down = 1;
+	list_for_each_entry(c, &session->conn_list, conn_list_entry) {
+		if (!c->conn_shutting_down) {
+			session->sess_shutting_down = 0;
+			break;
+		}
+	}
+
+	mutex_unlock(&session->target->target_mutex);
+
+	if (reinst) {
 		int rc;
 		int lun = 0;
 
@@ -525,14 +541,11 @@ static void close_conn(struct iscsi_conn *conn)
 
 	mutex_lock(&target->target_mutex);
 
-	free_sess = (conn->conn_reinst_successor == NULL);
 	conn->conn_reinst_successor = NULL;
-
 	conn_free(conn);
 
-	if (free_sess) {
+	if (list_empty(&session->conn_list)) {
 		sBUG_ON(session->sess_reinst_successor != NULL);
-		/* ToDo: this is incompatible with MC/S */
 		session_free(session);
 	}
 
diff --git a/iscsi-scst/kernel/session.c b/iscsi-scst/kernel/session.c
index f81688d88..821ad9469 100644
--- a/iscsi-scst/kernel/session.c
+++ b/iscsi-scst/kernel/session.c
@@ -184,8 +184,10 @@ int session_add(struct iscsi_target *target,
 		i.id.tsih = 0;
 		if ((sid.id64 == i.id64) &&
 		    (strcmp(info->initiator_name, session->initiator_name) == 0)) {
-		    	/* session reinstatement */
-		    	old_sess = session;
+		    	if (!session->sess_shutting_down) {
+				/* session reinstatement */
+				old_sess = session;
+			}
 			break;
 		}
 	}