ctdb-recoverd: Generalise helper state, handler and launching

These can also be used for takeover handler.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>

diff --git a/ctdb/server/ctdb_recoverd.c b/ctdb/server/ctdb_recoverd.c
index 1e04960c92360a74bf0a7b44215710e04c158905..12ab5635dbeebd70156accb48fd12a3faa7a7053 100644 (file)
--- a/ctdb/server/ctdb_recoverd.c
+++ b/ctdb/server/ctdb_recoverd.c
@@ -995,6 +995,124 @@ static void ban_misbehaving_nodes(struct ctdb_recoverd *rec, bool *self_ban)
        }
 }
 
+struct helper_state {
+       int fd[2];
+       pid_t pid;
+       int result;
+       bool done;
+};
+
+static void helper_handler(struct tevent_context *ev,
+                          struct tevent_fd *fde,
+                          uint16_t flags, void *private_data)
+{
+       struct helper_state *state = talloc_get_type_abort(
+               private_data, struct helper_state);
+       int ret;
+
+       ret = sys_read(state->fd[0], &state->result, sizeof(state->result));
+       if (ret != sizeof(state->result)) {
+               state->result = EPIPE;
+       }
+
+       state->done = true;
+}
+
+static int helper_run(struct ctdb_recoverd *rec, TALLOC_CTX *mem_ctx,
+                     const char *prog, const char *arg, const char *type)
+{
+       struct helper_state *state;
+       struct tevent_fd *fde;
+       const char **args;
+       int nargs, ret;
+
+       state = talloc_zero(mem_ctx, struct helper_state);
+       if (state == NULL) {
+               DEBUG(DEBUG_ERR, (__location__ " memory error\n"));
+               return -1;
+       }
+
+       state->pid = -1;
+
+       ret = pipe(state->fd);
+       if (ret != 0) {
+               DEBUG(DEBUG_ERR,
+                     ("Failed to create pipe for %s helper\n", type));
+               goto fail;
+       }
+
+       set_close_on_exec(state->fd[0]);
+
+       nargs = 4;
+       args = talloc_array(state, const char *, nargs);
+       if (args == NULL) {
+               DEBUG(DEBUG_ERR, (__location__ " memory error\n"));
+               goto fail;
+       }
+
+       args[0] = talloc_asprintf(args, "%d", state->fd[1]);
+       if (args[0] == NULL) {
+               DEBUG(DEBUG_ERR, (__location__ " memory error\n"));
+               goto fail;
+       }
+       args[1] = rec->ctdb->daemon.name;
+       args[2] = arg;
+       args[3] = NULL;
+
+       if (args[2] == NULL) {
+               nargs = 3;
+       }
+
+       state->pid = ctdb_vfork_exec(state, rec->ctdb, prog, nargs, args);
+       if (state->pid == -1) {
+               DEBUG(DEBUG_ERR,
+                     ("Failed to create child for %s helper\n", type));
+               goto fail;
+       }
+
+       close(state->fd[1]);
+       state->fd[1] = -1;
+
+       state->done = false;
+
+       fde = tevent_add_fd(rec->ctdb->ev, rec->ctdb, state->fd[0],
+                           TEVENT_FD_READ, helper_handler, state);
+       if (fde == NULL) {
+               goto fail;
+       }
+       tevent_fd_set_auto_close(fde);
+
+       while (!state->done) {
+               tevent_loop_once(rec->ctdb->ev);
+       }
+
+       close(state->fd[0]);
+       state->fd[0] = -1;
+
+       if (state->result != 0) {
+               goto fail;
+       }
+
+       ctdb_kill(rec->ctdb, state->pid, SIGKILL);
+       talloc_free(state);
+       return 0;
+
+fail:
+       if (state->fd[0] != -1) {
+               close(state->fd[0]);
+       }
+       if (state->fd[1] != -1) {
+               close(state->fd[1]);
+       }
+       if (state->pid != -1) {
+               ctdb_kill(rec->ctdb, state->pid, SIGKILL);
+       }
+       talloc_free(state);
+       return -1;
+}
+
+
+
 static bool do_takeover_run(struct ctdb_recoverd *rec,
                            struct ctdb_node_map_old *nodemap)
 {
@@ -1084,37 +1202,10 @@ done:
        return ok;
 }
 
-struct recovery_helper_state {
-       int fd[2];
-       pid_t pid;
-       int result;
-       bool done;
-};
-
-static void ctdb_recovery_handler(struct tevent_context *ev,
-                                 struct tevent_fd *fde,
-                                 uint16_t flags, void *private_data)
-{
-       struct recovery_helper_state *state = talloc_get_type_abort(
-               private_data, struct recovery_helper_state);
-       int ret;
-
-       ret = sys_read(state->fd[0], &state->result, sizeof(state->result));
-       if (ret != sizeof(state->result)) {
-               state->result = EPIPE;
-       }
-
-       state->done = true;
-}
-
-
 static int db_recovery_parallel(struct ctdb_recoverd *rec, TALLOC_CTX *mem_ctx)
 {
        static char prog[PATH_MAX+1] = "";
-       const char **args;
-       struct recovery_helper_state *state;
-       struct tevent_fd *fde;
-       int nargs, ret;
+       const char *arg;
 
        if (!ctdb_set_helper("recovery_helper", prog, sizeof(prog),
                             "CTDB_RECOVERY_HELPER", CTDB_HELPER_BINDIR,
@@ -1122,88 +1213,15 @@ static int db_recovery_parallel(struct ctdb_recoverd *rec, TALLOC_CTX *mem_ctx)
                ctdb_die(rec->ctdb, "Unable to set recovery helper\n");
        }
 
-       state = talloc_zero(mem_ctx, struct recovery_helper_state);
-       if (state == NULL) {
+       arg = talloc_asprintf(mem_ctx, "%u", new_generation());
+       if (arg == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " memory error\n"));
                return -1;
        }
 
-       state->pid = -1;
-
-       ret = pipe(state->fd);
-       if (ret != 0) {
-               DEBUG(DEBUG_ERR,
-                     ("Failed to create pipe for recovery helper\n"));
-               goto fail;
-       }
-
-       set_close_on_exec(state->fd[0]);
-
-       nargs = 4;
-       args = talloc_array(state, const char *, nargs);
-       if (args == NULL) {
-               DEBUG(DEBUG_ERR, (__location__ " memory error\n"));
-               goto fail;
-       }
-
-       args[0] = talloc_asprintf(args, "%d", state->fd[1]);
-       args[1] = rec->ctdb->daemon.name;
-       args[2] = talloc_asprintf(args, "%u", new_generation());
-       args[3] = NULL;
-
-       if (args[0] == NULL || args[2] == NULL) {
-               DEBUG(DEBUG_ERR, (__location__ " memory error\n"));
-               goto fail;
-       }
-
        setenv("CTDB_DBDIR_STATE", rec->ctdb->db_directory_state, 1);
 
-       state->pid = ctdb_vfork_exec(state, rec->ctdb, prog, nargs, args);
-       if (state->pid == -1) {
-               DEBUG(DEBUG_ERR,
-                     ("Failed to create child for recovery helper\n"));
-               goto fail;
-       }
-
-       close(state->fd[1]);
-       state->fd[1] = -1;
-
-       state->done = false;
-
-       fde = tevent_add_fd(rec->ctdb->ev, rec->ctdb, state->fd[0],
-                           TEVENT_FD_READ, ctdb_recovery_handler, state);
-       if (fde == NULL) {
-               goto fail;
-       }
-       tevent_fd_set_auto_close(fde);
-
-       while (!state->done) {
-               tevent_loop_once(rec->ctdb->ev);
-       }
-
-       close(state->fd[0]);
-       state->fd[0] = -1;
-
-       if (state->result != 0) {
-               goto fail;
-       }
-
-       ctdb_kill(rec->ctdb, state->pid, SIGKILL);
-       talloc_free(state);
-       return 0;
-
-fail:
-       if (state->fd[0] != -1) {
-               close(state->fd[0]);
-       }
-       if (state->fd[1] != -1) {
-               close(state->fd[1]);
-       }
-       if (state->pid != -1) {
-               ctdb_kill(rec->ctdb, state->pid, SIGKILL);
-       }
-       talloc_free(state);
-       return -1;
+       return helper_run(rec, mem_ctx, prog, arg, "recovery");
 }
 
 /*