RDS: lock rds_conn_count decrement in rds_conn_destroy()

rds_conn_destroy() can race with all other modifications of the
rds_conn_count but it was modifying the count without locking.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 0de40d9563ca..75a1a37d64d3 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -313,6 +313,7 @@ void rds_conn_shutdown(struct rds_connection *conn)
 void rds_conn_destroy(struct rds_connection *conn)
 {
         struct rds_message *rm, *rtmp;
+        unsigned long flags;
 
         rdsdebug("freeing conn %p for %pI4 -> "
                  "%pI4\n", conn, &conn->c_laddr,
@@ -350,7 +351,9 @@ void rds_conn_destroy(struct rds_connection *conn)
         BUG_ON(!list_empty(&conn->c_retrans));
         kmem_cache_free(rds_conn_slab, conn);
 
+        spin_lock_irqsave(&rds_conn_lock, flags);
         rds_conn_count--;
+        spin_unlock_irqrestore(&rds_conn_lock, flags);
 }
 EXPORT_SYMBOL_GPL(rds_conn_destroy);