proper waitpid() fix.

remove all waitpid() calls and use the event system to trap sigchld

diff --git a/server/ctdb_daemon.c b/server/ctdb_daemon.c
index 326ab60e0d4e2e685e19a87fd7a0db5c55ea844d..c153a975708326d56185f313da0a93ace455fb4e 100644 (file)
--- a/server/ctdb_daemon.c
+++ b/server/ctdb_daemon.c
@@ -628,6 +628,27 @@ static int unlink_destructor(const char *name)
        return 0;
 }
 
+static void sig_child_handler(struct event_context *ev,
+       struct signal_event *se, int signum, int count,
+       void *dont_care, 
+       void *private_data)
+{
+//     struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
+       int status;
+       pid_t pid = -1;
+
+       while (pid != 0) {
+               pid = waitpid(-1, &status, WNOHANG);
+               if (pid == -1) {
+                       DEBUG(DEBUG_ERR, (__location__ " waitpid() returned error. errno:%d\n", errno));
+                       return;
+               }
+               if (pid > 0) {
+                       DEBUG(DEBUG_DEBUG, ("SIGCHLD from %d\n", (int)pid));
+               }
+       }
+}
+
 /*
   start the protocol going as a daemon
 */
@@ -636,6 +657,7 @@ int ctdb_start_daemon(struct ctdb_context *ctdb, bool do_fork)
        int res, ret = -1;
        struct fd_event *fde;
        const char *domain_socket_name;
+       struct signal_event *se;
 
        /* get rid of any old sockets */
        unlink(ctdb->daemon.name);
@@ -731,6 +753,16 @@ int ctdb_start_daemon(struct ctdb_context *ctdb, bool do_fork)
        /* start the transport going */
        ctdb_start_transport(ctdb);
 
+       /* set up a handler to pick up sigchld */
+       se = event_add_signal(ctdb->ev, ctdb,
+                                    SIGCHLD, 0,
+                                    sig_child_handler,
+                                    ctdb);
+       if (se == NULL) {
+               DEBUG(DEBUG_CRIT,("Failed to set up signal handler for SIGCHLD\n"));
+               exit(1);
+       }
+         
        /* go into a wait loop to allow other nodes to complete */
        event_loop_wait(ctdb->ev);
 

diff --git a/server/ctdb_freeze.c b/server/ctdb_freeze.c
index 8e75f61a1d9bc04cae4f5db8f6c2903091425ed4..e39332e3859ab9478870f6ce8a5cc3584886a000 100644 (file)
--- a/server/ctdb_freeze.c
+++ b/server/ctdb_freeze.c
@@ -87,7 +87,6 @@ static int ctdb_freeze_handle_destructor(struct ctdb_freeze_handle *h)
        ctdb->freeze_handle = NULL;
 
        kill(h->child, SIGKILL);
-       waitpid(h->child, NULL, 0);
        return 0;
 }
 

diff --git a/server/ctdb_lockwait.c b/server/ctdb_lockwait.c
index 5b0019836e8f097f0ea816222eeee7ed55e74856..03a7eedf46cc4fff7b38f7f6b7e48488739f1d1f 100644 (file)
--- a/server/ctdb_lockwait.c
+++ b/server/ctdb_lockwait.c
@@ -72,7 +72,6 @@ static void lockwait_handler(struct event_context *ev, struct fd_event *fde,
        tdb_chainlock_unmark(tdb, key);
 
        kill(child, SIGKILL);
-       waitpid(child, NULL, 0);
        talloc_free(tmp_ctx);
 }
 
@@ -80,7 +79,6 @@ static int lockwait_destructor(struct lockwait_handle *h)
 {
        h->ctdb->statistics.pending_lockwait_calls--;
        kill(h->child, SIGKILL);
-       waitpid(h->child, NULL, 0);
        return 0;
 }
 

diff --git a/server/ctdb_persistent.c b/server/ctdb_persistent.c
index 3ba961eadba5f4e3507a8f58de047b0969541ac1..713950a0c9dbe4c603bcdf7452fbd603b84b9654 100644 (file)
--- a/server/ctdb_persistent.c
+++ b/server/ctdb_persistent.c
@@ -222,7 +222,6 @@ static int childwrite_destructor(struct childwrite_handle *h)
 {
        h->ctdb->statistics.pending_childwrite_calls--;
        kill(h->child, SIGKILL);
-       waitpid(h->child, NULL, 0);
        return 0;
 }
 
@@ -260,7 +259,6 @@ static void childwrite_handler(struct event_context *ev, struct fd_event *fde,
        callback(c, p);
 
        kill(child, SIGKILL);
-       waitpid(child, NULL, 0);
        talloc_free(tmp_ctx);
 }
 

diff --git a/server/ctdb_recover.c b/server/ctdb_recover.c
index 29673eac2e49337449db48768bee3e1653435a21..7b8d28c58a8f4ce7022569701e2ca90d4891bada 100644 (file)
--- a/server/ctdb_recover.c
+++ b/server/ctdb_recover.c
@@ -459,7 +459,6 @@ static void ctdb_set_recmode_timeout(struct event_context *ev, struct timed_even
 static int set_recmode_destructor(struct ctdb_set_recmode_state *state)
 {
        kill(state->child, SIGKILL);
-       waitpid(state->child, NULL, 0);
        return 0;
 }
 

diff --git a/server/ctdb_recoverd.c b/server/ctdb_recoverd.c
index 80443bb75ad19efde7ca7518afc5bcc88909a9a4..69d867afdb52f900e0b2740d6c4bf362c4141343 100644 (file)
--- a/server/ctdb_recoverd.c
+++ b/server/ctdb_recoverd.c
@@ -2933,11 +2933,6 @@ static void ctdb_check_recd(struct event_context *ev, struct timed_event *te,
 {
        struct ctdb_context *ctdb = talloc_get_type(p, struct ctdb_context);
 
-       /* make sure we harvest the child if signals are blocked for some
-          reason
-       */
-       waitpid(ctdb->recoverd_pid, 0, WNOHANG);
-
        if (kill(ctdb->recoverd_pid, 0) != 0) {
                DEBUG(DEBUG_ERR,("Recovery daemon (pid:%d) is no longer running. Shutting down main daemon\n", (int)ctdb->recoverd_pid));
 
@@ -2958,6 +2953,27 @@ static void ctdb_check_recd(struct event_context *ev, struct timed_event *te,
                        ctdb_check_recd, ctdb);
 }
 
+static void recd_sig_child_handler(struct event_context *ev,
+       struct signal_event *se, int signum, int count,
+       void *dont_care, 
+       void *private_data)
+{
+//     struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
+       int status;
+       pid_t pid = -1;
+
+       while (pid != 0) {
+               pid = waitpid(-1, &status, WNOHANG);
+               if (pid == -1) {
+                       DEBUG(DEBUG_ERR, (__location__ " waitpid() returned error. errno:%d\n", errno));
+                       return;
+               }
+               if (pid > 0) {
+                       DEBUG(DEBUG_DEBUG, ("RECD SIGCHLD from %d\n", (int)pid));
+               }
+       }
+}
+
 /*
   startup the recovery daemon as a child of the main ctdb daemon
  */
@@ -2965,6 +2981,7 @@ int ctdb_start_recoverd(struct ctdb_context *ctdb)
 {
        int ret;
        int fd[2];
+       struct signal_event *se;
 
        if (pipe(fd) != 0) {
                return -1;
@@ -3016,6 +3033,16 @@ int ctdb_start_recoverd(struct ctdb_context *ctdb)
                exit(1);
        }
 
+       /* set up a handler to pick up sigchld */
+       se = event_add_signal(ctdb->ev, ctdb,
+                                    SIGCHLD, 0,
+                                    recd_sig_child_handler,
+                                    ctdb);
+       if (se == NULL) {
+               DEBUG(DEBUG_CRIT,("Failed to set up signal handler for SIGCHLD in recovery daemon\n"));
+               exit(1);
+       }
+
        monitor_cluster(ctdb);
 
        DEBUG(DEBUG_ALERT,("ERROR: ctdb_recoverd finished!?\n"));

diff --git a/server/ctdb_traverse.c b/server/ctdb_traverse.c
index 6c84d024e625d55962643c785b66e4c7531c9b5b..10895ed59e6d91ecdb58d840821caacea4731d1f 100644 (file)
--- a/server/ctdb_traverse.c
+++ b/server/ctdb_traverse.c
@@ -74,7 +74,6 @@ static void ctdb_traverse_local_handler(uint8_t *rawdata, size_t length, void *p
 static int traverse_local_destructor(struct ctdb_traverse_local_handle *h)
 {
        kill(h->child, SIGKILL);
-       waitpid(h->child, NULL, 0);
        return 0;
 }
 

diff --git a/server/eventscript.c b/server/eventscript.c
index 54d914b35cf3d3c8f4e8316df0f5b9bb3c1b2b84..1d42b2be493963c8d54cb3436694d143517dd4cd 100644 (file)
--- a/server/eventscript.c
+++ b/server/eventscript.c
@@ -210,18 +210,16 @@ static void ctdb_event_script_handler(struct event_context *ev, struct fd_event
 {
        struct ctdb_event_script_state *state = 
                talloc_get_type(p, struct ctdb_event_script_state);
-       int status = -1;
        void (*callback)(struct ctdb_context *, int, void *) = state->callback;
        void *private_data = state->private_data;
        struct ctdb_context *ctdb = state->ctdb;
+       signed char rt = -1;
+
+       read(state->fd[0], &rt, sizeof(rt));
 
-       waitpid(state->child, &status, 0);
-       if (status != -1) {
-               status = WEXITSTATUS(status);
-       }
        talloc_set_destructor(state, NULL);
        talloc_free(state);
-       callback(ctdb, status, private_data);
+       callback(ctdb, rt, private_data);
 
        ctdb->event_script_timeouts = 0;
 }
@@ -293,7 +291,6 @@ static int event_script_destructor(struct ctdb_event_script_state *state)
 {
        DEBUG(DEBUG_ERR,(__location__ " Sending SIGTERM to child pid:%d\n", state->child));
        kill(state->child, SIGTERM);
-       waitpid(state->child, NULL, 0);
        return 0;
 }
 
@@ -336,13 +333,18 @@ static int ctdb_event_script_callback_v(struct ctdb_context *ctdb,
        }
 
        if (state->child == 0) {
+               signed char rt;
+
                close(state->fd[0]);
                if (ctdb->do_setsched) {
                        ctdb_restore_scheduler(ctdb);
                }
                set_close_on_exec(state->fd[1]);
-               ret = ctdb_event_script_v(ctdb, state->options);
-               _exit(ret);
+               rt = ctdb_event_script_v(ctdb, state->options);
+               while ((ret = write(state->fd[1], &rt, sizeof(rt))) != sizeof(rt)) {
+                       sleep(1);
+               }
+               _exit(rt);
        }
 
        talloc_set_destructor(state, event_script_destructor);