eventscript: refactor forking code into fork_child_for_script()

We do the same thing in two places: fire off a child from the initial
ctdb_event_script_callback_v() and also from the ctdb_event_script_handler()
when it's done.

Unify this logic into fork_child_for_script().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/server/eventscript.c b/server/eventscript.c
index 9e7d05c5797aa1853b1419fa783d7d529cfc0ea9..c22163b8b6fc6991a4fed928a01087ca78c74d0f 100644 (file)
--- a/server/eventscript.c
+++ b/server/eventscript.c
@@ -581,6 +581,55 @@ out:
        return ret;
 }
 
+static void ctdb_event_script_handler(struct event_context *ev, struct fd_event *fde,
+                                     uint16_t flags, void *p);
+
+static int fork_child_for_script(struct ctdb_context *ctdb,
+                                struct ctdb_event_script_state *state)
+{
+       int r;
+
+       r = pipe(state->fd);
+       if (r != 0) {
+               DEBUG(DEBUG_ERR, (__location__ " pipe failed for child eventscript process\n"));
+               return -errno;
+       }
+
+       state->child = fork();
+
+       if (state->child == (pid_t)-1) {
+               r = -errno;
+               DEBUG(DEBUG_ERR, (__location__ " fork failed for child eventscript process\n"));
+               close(state->fd[0]);
+               close(state->fd[1]);
+               return r;
+       }
+
+       if (state->child == 0) {
+               int rt;
+
+               close(state->fd[0]);
+               set_close_on_exec(state->fd[1]);
+
+               rt = child_run_script(ctdb, state->from_user, state->call, state->options, state->script_list);
+               /* We must be able to write PIPEBUF bytes at least; if this
+                  somehow fails, the read above will be short. */
+               write(state->fd[1], &rt, sizeof(rt));
+               close(state->fd[1]);
+               _exit(rt);
+       }
+
+       close(state->fd[1]);
+       set_close_on_exec(state->fd[0]);
+
+       DEBUG(DEBUG_DEBUG, (__location__ " Created PIPE FD:%d to child eventscript process\n", state->fd[0]));
+
+       /* Set ourselves up to be called when that's done. */
+       event_add_fd(ctdb->ev, state, state->fd[0], EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
+                    ctdb_event_script_handler, state);
+       return 0;
+}
+
 /* called when child is finished */
 static void ctdb_event_script_handler(struct event_context *ev, struct fd_event *fde, 
                                      uint16_t flags, void *p)
@@ -622,48 +671,14 @@ static void ctdb_event_script_handler(struct event_context *ev, struct fd_event
        talloc_free(fde);
 
        /* Next script! */
-       r = pipe(state->fd);
-       if (r != 0) {
-               state->cb_status = -errno;
-               goto abort;
-       }
-
-       state->child = fork();
-
-       if (state->child == (pid_t)-1) {
-               state->cb_status = -errno;
-               close(state->fd[0]);
-               close(state->fd[1]);
-               goto abort;
-       }
-
-       if (state->child == 0) {
-               int rt;
-
-               close(state->fd[0]);
-               set_close_on_exec(state->fd[1]);
-
-               rt = child_run_script(ctdb, state->from_user, state->call, state->options, state->script_list);
-               /* We must be able to write PIPEBUF bytes at least; if this
-                  somehow fails, the read above will be short. */
-               write(state->fd[1], &rt, sizeof(rt));
-               close(state->fd[1]);
-               _exit(rt);
+       state->cb_status = fork_child_for_script(ctdb, state);
+       if (state->cb_status != 0) {
+               if (!state->from_user && state->call == CTDB_EVENT_MONITOR) {
+                       ctdb_control_event_script_finished(ctdb);
+               }
+               /* This calls the callback. */
+               talloc_free(state);
        }
-
-       close(state->fd[1]);
-       set_close_on_exec(state->fd[0]);
-
-       DEBUG(DEBUG_DEBUG, (__location__ " Created PIPE FD:%d to child eventscript process\n", state->fd[0]));
-
-       /* Set ourselves up to be called when that's done. */
-       event_add_fd(ctdb->ev, state, state->fd[0], EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
-                    ctdb_event_script_handler, state);
-       return;
-
-abort:
-       /* This calls the callback. */
-       talloc_free(state);
 }
 
 /* called when child times out */
@@ -834,51 +849,17 @@ static int ctdb_event_script_callback_v(struct ctdb_context *ctdb,
                return -1;
        }
 
-       ret = pipe(state->fd);
-       if (ret != 0) {
-               talloc_free(state);
-               return -1;
-       }
-
        if (!state->from_user && state->call == CTDB_EVENT_MONITOR) {
                ctdb_control_event_script_init(ctdb);
        }
 
-       state->child = fork();
-
-       if (state->child == (pid_t)-1) {
-               if (!state->from_user && state->call == CTDB_EVENT_MONITOR) {
-                       ctdb_control_event_script_finished(ctdb);
-               }
-               close(state->fd[0]);
-               close(state->fd[1]);
+       ret = fork_child_for_script(ctdb, state);
+       if (ret != 0) {
                talloc_free(state);
                return -1;
        }
 
-       if (state->child == 0) {
-               int rt;
-
-               close(state->fd[0]);
-               set_close_on_exec(state->fd[1]);
-
-               rt = child_run_script(ctdb, state->from_user, state->call, state->options, state->script_list);
-               /* We must be able to write PIPEBUF bytes at least; if this
-                  somehow fails, the read above will be short. */
-               write(state->fd[1], &rt, sizeof(rt));
-               close(state->fd[1]);
-               _exit(rt);
-       }
-
-       close(state->fd[1]);
-       set_close_on_exec(state->fd[0]);
        talloc_set_destructor(state, event_script_destructor);
-
-       DEBUG(DEBUG_DEBUG, (__location__ " Created PIPE FD:%d to child eventscript process\n", state->fd[0]));
-
-       event_add_fd(ctdb->ev, state, state->fd[0], EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
-                    ctdb_event_script_handler, state);
-
        if (!timeval_is_zero(&state->timeout)) {
                event_add_timed(ctdb->ev, state, timeval_current_ofs(state->timeout.tv_sec, state->timeout.tv_usec), ctdb_event_script_timeout, state);
        } else {