rpc-clnt: separate out connection_cleanup() from destroy()v3.3.0qa30

noticed that there are possibilities where one would like to do a
connection_cleanup() before destroying a RPC connection itself, also
current code is such that, rpc_clnt_connection_cleanup() does
rpc_clnt_ref() and unref(), creating a race window/double unref
possibilities in the code.

by separating out the functions, this race window/double fault can be
prevented.

Change-Id: I7ebd3392efa891232857b6db9108b0b19e40fc12
Signed-off-by: Amar Tumballi <amarts@redhat.com>
BUG: 802403
Reviewed-on: http://review.gluster.com/2979
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/xlators/nfs/server/src/nlm4.c b/xlators/nfs/server/src/nlm4.c
index 0a0d2636649..16507d069d3 100644
--- a/xlators/nfs/server/src/nlm4.c
+++ b/xlators/nfs/server/src/nlm4.c
@@ -315,8 +315,14 @@ nlm_set_rpc_clnt (rpc_clnt_t *rpc_clnt, char *caller_name)
         ret = 0;
 ret:
         UNLOCK (&nlm_client_list_lk);
-        if (rpc_clnt_old)
+
+        if (rpc_clnt_old) {
+                /* cleanup the saved-frames before last unref */
+                rpc_clnt_connection_cleanup (&rpc_clnt_old->conn);
+
                 rpc_clnt_unref (rpc_clnt_old);
+        }
+
         if (old_name)
                 GF_FREE (old_name);
         return ret;
@@ -340,8 +346,12 @@ nlm_unset_rpc_clnt (rpc_clnt_t *rpc)
         if (rpc_clnt == NULL) {
                 return -1;
         }
-        if (rpc_clnt)
+        if (rpc_clnt) {
+                /* cleanup the saved-frames before last unref */
+                rpc_clnt_connection_cleanup (&rpc_clnt->conn);
+
                 rpc_clnt_unref (rpc_clnt);
+        }
         return 0;
 }