cli: fix data race when handling connection status

Found with GCC ThreadSanitizer:

WARNING: ThreadSanitizer: data race (pid=287943)
  Write of size 4 at 0x00000047dfa0 by thread T4:
    #0 cli_rpc_notify /path/to/glusterfs/cli/src/cli.c:313 (gluster+0x40a6df)
    #1 rpc_clnt_handle_disconnect /path/to/glusterfs/rpc/rpc-lib/src/rpc-clnt.c:821 (libgfrpc.so.0+0x13f04)
    #2 rpc_clnt_notify /path/to/glusterfs/rpc/rpc-lib/src/rpc-clnt.c:882 (libgfrpc.so.0+0x13f04)
    #3 rpc_transport_notify /path/to/glusterfs/rpc/rpc-lib/src/rpc-transport.c:520 (libgfrpc.so.0+0xf070)
    #4 socket_event_poll_err /path/to/glusterfs/rpc/rpc-transport/socket/src/socket.c:1364 (socket.so+0x812c)
    #5 socket_event_handler /path/to/glusterfs/rpc/rpc-transport/socket/src/socket.c:2958 (socket.so+0xc453)
    #6 socket_event_handler /path/to/glusterfs/rpc/rpc-transport/socket/src/socket.c:2854 (socket.so+0xc453)
    #7 event_dispatch_epoll_handler /path/to/glusterfs/libglusterfs/src/event-epoll.c:640 (libglusterfs.so.0+0xcaf23)
    #8 event_dispatch_epoll_worker /path/to/glusterfs/libglusterfs/src/event-epoll.c:751 (libglusterfs.so.0+0xcaf23)
    #9 <null> <null> (libtsan.so.0+0x2d33f)

  Previous read of size 4 at 0x00000047dfa0 by thread T3 (mutexes: write M3587):
    #0 cli_cmd_await_connected /path/to/glusterfs/cli/src/cli-cmd.c:321 (gluster+0x40ca37)
    #1 cli_cmd_process /path/to/glusterfs/cli/src/cli-cmd.c:123 (gluster+0x40cc74)
    #2 cli_batch /path/to/glusterfs/cli/src/input.c:29 (gluster+0x40c2b9)
    #3 <null> <null> (libtsan.so.0+0x2d33f)

  Location is global 'connected' of size 4 at 0x00000047dfa0 (gluster+0x00000047dfa0)

Change-Id: Ie85a8a80a2c5b82252c0c1d45e68ebe9938da2eb
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Fixes: #1311

1 files changed, 17 insertions, 4 deletions

diff --git a/cli/src/cli-cmd.c b/cli/src/cli-cmd.c
index af009757e93..2d458b16a56 100644
--- a/cli/src/cli-cmd.c
+++ b/cli/src/cli-cmd.c
@@ -28,7 +28,7 @@ static pthread_cond_t conn = PTHREAD_COND_INITIALIZER;
 static pthread_mutex_t conn_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 int cli_op_ret = 0;
-int connected = 0;
+static gf_boolean_t connected = _gf_false;
 
 static unsigned
 cli_cmd_needs_connection(struct cli_cmd_word *word)
@@ -328,19 +328,32 @@ cli_cmd_await_connected(unsigned conn_timo)
 }
 
 int32_t
-cli_cmd_broadcast_connected()
+cli_cmd_broadcast_connected(gf_boolean_t status)
 {
     pthread_mutex_lock(&conn_mutex);
     {
-        connected = 1;
+        connected = status;
         pthread_cond_broadcast(&conn);
     }
-
     pthread_mutex_unlock(&conn_mutex);
 
     return 0;
 }
 
+gf_boolean_t
+cli_cmd_connected(void)
+{
+    gf_boolean_t status;
+
+    pthread_mutex_lock(&conn_mutex);
+    {
+        status = connected;
+    }
+    pthread_mutex_unlock(&conn_mutex);
+
+    return status;
+}
+
 int
 cli_cmd_submit(struct rpc_clnt *rpc, void *req, call_frame_t *frame,
                rpc_clnt_prog_t *prog, int procnum, struct iobref *iobref,