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 <[email protected]>
Fixes: #1311

Author: dmantipov

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,

cli/src/cli-rpc-ops.c

@@ -50,7 +50,6 @@ enum gf_task_types { GF_TASK_TYPE_REBALANCE, GF_TASK_TYPE_REMOVE_BRICK };
 extern struct rpc_clnt *global_quotad_rpc;
 rpc_clnt_prog_t cli_quotad_clnt;
 extern rpc_clnt_prog_t *cli_rpc_prog;
-extern int connected;
 
 static int32_t
 gf_cli_remove_brick(call_frame_t *frame, xlator_t *this, void *data);
@@ -3406,7 +3405,7 @@ gf_cli_quota_list(cli_local_t *local, char *volname, dict_t *dict,
                   char *default_sl, int count, int op_ret, int op_errno,
                   char *op_errstr)
 {
-    if (!connected)
+    if (!cli_cmd_connected())
         goto out;
 
     if (count > 0) {

cli/src/cli.c

@@ -55,7 +55,6 @@
 
 #include "xdr-generic.h"
 
-extern int connected;
 /* using argp for command line parsing */
 
 const char *argp_program_version =
@@ -303,14 +302,14 @@ cli_rpc_notify(struct rpc_clnt *rpc, void *mydata, rpc_clnt_event_t event,
 
     switch (event) {
         case RPC_CLNT_CONNECT: {
-            cli_cmd_broadcast_connected();
+            cli_cmd_broadcast_connected(_gf_true);
             gf_log(this->name, GF_LOG_TRACE, "got RPC_CLNT_CONNECT");
             break;
         }
 
         case RPC_CLNT_DISCONNECT: {
+            cli_cmd_broadcast_connected(_gf_false);
             gf_log(this->name, GF_LOG_TRACE, "got RPC_CLNT_DISCONNECT");
-            connected = 0;
             if (!global_state->prompt && global_state->await_connected) {
                 ret = 1;
                 cli_out(

cli/src/cli.h

@@ -329,11 +329,14 @@ cli_local_get();
 void
 cli_local_wipe(cli_local_t *local);
 
+gf_boolean_t
+cli_cmd_connected();
+
 int32_t
-cli_cmd_await_connected();
+cli_cmd_await_connected(unsigned timeout);
 
 int32_t
-cli_cmd_broadcast_connected();
+cli_cmd_broadcast_connected(gf_boolean_t status);
 
 int
 cli_rpc_notify(struct rpc_clnt *rpc, void *mydata, rpc_clnt_event_t event,