glusterd/rpc : Discard duplicate Disconnect events

If a peer rpc disconnect event has been already processed, skip the furthers as
processing them are overheads and sometimes may lead to a crash like due to a
double free

Change-Id: Iec589ce85daf28fd5b267cb6fc82a4238e0e8adc
BUG: 1318546
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-on: http://review.gluster.org/13790
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

2 files changed, 24 insertions, 0 deletions

diff --git a/rpc/rpc-lib/src/rpc-clnt.c b/rpc/rpc-lib/src/rpc-clnt.c
index 2ae3bbad370..27e394093cf 100644
--- a/rpc/rpc-lib/src/rpc-clnt.c
+++ b/rpc/rpc-lib/src/rpc-clnt.c
@@ -782,6 +782,7 @@ rpc_clnt_set_connected (rpc_clnt_connection_t *conn)
         pthread_mutex_lock (&conn->lock);
         {
                 conn->connected = 1;
+                conn->disconnected = _gf_false;
         }
         pthread_mutex_unlock (&conn->lock);
 
@@ -800,6 +801,7 @@ rpc_clnt_unset_connected (rpc_clnt_connection_t *conn)
         pthread_mutex_lock (&conn->lock);
         {
                 conn->connected = 0;
+                conn->disconnected = _gf_true;
         }
         pthread_mutex_unlock (&conn->lock);
 
@@ -807,6 +809,24 @@ out:
         return;
 }
 
+gf_boolean_t
+is_rpc_clnt_disconnected (rpc_clnt_connection_t *conn)
+{
+        gf_boolean_t disconnected = _gf_true;
+
+        if (!conn)
+                return disconnected;
+
+        pthread_mutex_lock (&conn->lock);
+        {
+                if (conn->disconnected == _gf_false)
+                        disconnected = _gf_false;
+        }
+        pthread_mutex_unlock (&conn->lock);
+
+        return disconnected;
+}
+
 static void
 rpc_clnt_destroy (struct rpc_clnt *rpc);
 
diff --git a/rpc/rpc-lib/src/rpc-clnt.h b/rpc/rpc-lib/src/rpc-clnt.h
index 6a4bb40793f..01caeb814c0 100644
--- a/rpc/rpc-lib/src/rpc-clnt.h
+++ b/rpc/rpc-lib/src/rpc-clnt.h
@@ -140,6 +140,7 @@ struct rpc_clnt_connection {
         gf_timer_t              *ping_timer;
         struct rpc_clnt         *rpc_clnt;
         char                     connected;
+        gf_boolean_t             disconnected;
         struct saved_frames     *saved_frames;
         int32_t                  frame_timeout;
 	struct timeval           last_sent;
@@ -234,6 +235,9 @@ int rpc_clnt_connection_cleanup (rpc_clnt_connection_t *conn);
 void rpc_clnt_set_connected (rpc_clnt_connection_t *conn);
 
 void rpc_clnt_unset_connected (rpc_clnt_connection_t *conn);
+
+gf_boolean_t is_rpc_clnt_disconnected (rpc_clnt_connection_t *conn);
+
 void rpc_clnt_reconnect (void *trans_ptr);
 
 void rpc_clnt_reconfig (struct rpc_clnt *rpc, struct rpc_clnt_config *config);