protocol/server: Avoid race in add/del locker, connection_cleanup

conn->ltable address keeps changing in
server_connection_cleanup every time it is called.
i.e. New ltable is created every time it is called.
Here is the race that happened:
---------------------------------------------------
thread-1                        | thread-2
add_locker is called with       |
conn->ltable. lets call the     |
ltable address lt1              |
                                | connection cleanup is called
                                | and do_lock_table_cleanup is
                                | triggered for lt1. locker
                                | lists are splice_inited under
                                | the lt1->lock
lt1 adds the locker under       |
lt1->lock (lets call this l1)   |
                                | GF_FREE(lt1) happens in
                                | do_lock_table_cleanup

The locker l1 that is added just before lt1 is freed will never
be cleared in the subsequent server_connection_cleanups as there
does not exist a reference to the locker. The stale lock remains
in the locks xlator even though the transport on which it was
issued is destroyed.

Change-Id: I0a02f16c703d1e7598b083aa1057cda9624eb3fe
BUG: 787601
Signed-off-by: Pranith Kumar K <pranithk@gluster.com>
Reviewed-on: http://review.gluster.com/2957
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/xlators/protocol/server/src/server.h b/xlators/protocol/server/src/server.h
index 6024d100b30..831c309a245 100644
--- a/xlators/protocol/server/src/server.h
+++ b/xlators/protocol/server/src/server.h
@@ -49,7 +49,6 @@ struct _locker {
 struct _lock_table {
         struct list_head  inodelk_lockers;
         struct list_head  entrylk_lockers;
-        gf_lock_t         lock;
         size_t            count;
 };