source4 smbd prefork: Pass restart information

Pass information about the pre-fork master and worker processes that
will allow them to be restarted.

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/smbd/process_prefork.c b/source4/smbd/process_prefork.c
index 016385c762c2836ba4ce1d481ce6279575cf0644..c8ed942b7413458019632c7ec9450e392900dd47 100644 (file)
--- a/source4/smbd/process_prefork.c
+++ b/source4/smbd/process_prefork.c
@@ -37,6 +37,35 @@
 
 NTSTATUS process_model_prefork_init(void);
 
+/*
+ * State needed to restart the master process or a worker process if they
+ * terminate early.
+ */
+struct master_restart_context {
+       struct loadparm_context *lp_ctx;
+       struct task_server *(*new_task_fn)(struct tevent_context *,
+                                          struct loadparm_context *lp_ctx,
+                                          struct server_id,
+                                          void *,
+                                          void *);
+       void *private_data;
+};
+
+struct worker_restart_context {
+       unsigned int instance;
+       struct task_server *task;
+       struct tevent_context *ev2;
+};
+
+struct restart_context {
+       struct tfork *t;
+       int from_parent_fd;
+       const struct service_details *service_details;
+       const char *service_name;
+       struct master_restart_context *master;
+       struct worker_restart_context *worker;
+};
+
 static void sighup_signal_handler(struct tevent_context *ev,
                                struct tevent_signal *se,
                                int signum, int count, void *siginfo,
@@ -110,7 +139,7 @@ static void prefork_child_pipe_handler(struct tevent_context *ev,
                                       uint16_t flags,
                                       void *private_data)
 {
-       struct tfork *t = NULL;
+       struct restart_context *rc = NULL;
        int status = 0;
        pid_t pid = 0;
 
@@ -119,11 +148,10 @@ static void prefork_child_pipe_handler(struct tevent_context *ev,
 
        /* the child has closed the pipe, assume its dead */
 
-       /* tfork allocates tfork structures with malloc  */
-       t = (struct tfork*)private_data;
-       pid = tfork_child_pid(t);
+       rc = talloc_get_type_abort(private_data, struct restart_context);
+       pid = tfork_child_pid(rc->t);
        errno = 0;
-       status = tfork_status(&t, false);
+       status = tfork_status(&rc->t, false);
        if (status == -1) {
                DBG_ERR("Parent %d, Child %d terminated, "
                        "unable to get status code from tfork\n",
@@ -138,7 +166,8 @@ static void prefork_child_pipe_handler(struct tevent_context *ev,
                        getpid(), pid, status);
        }
        /* tfork allocates tfork structures with malloc */
-       free(t);
+       free(rc->t);
+       TALLOC_FREE(rc);
        return;
 }
 
@@ -220,6 +249,72 @@ static void setup_handlers(struct tevent_context *ev, int from_parent_fd) {
        }
 }
 
+static void prefork_fork_worker(struct task_server *task,
+                               struct tevent_context *ev,
+                               struct tevent_context *ev2,
+                               const struct service_details *service_details,
+                               const char *service_name,
+                               int from_parent_fd,
+                               struct process_details *pd)
+{
+       struct tfork *w = NULL;
+       pid_t pid;
+
+       w = tfork_create();
+       if (w == NULL) {
+               smb_panic("failure in tfork\n");
+       }
+
+       pid = tfork_child_pid(w);
+       if (pid != 0) {
+               struct tevent_fd *fde = NULL;
+               int fd = tfork_event_fd(w);
+               struct restart_context *rc = NULL;
+
+               rc = talloc_zero(ev, struct restart_context);
+               if (rc == NULL) {
+                       smb_panic("OOM allocating restart context\n");
+               }
+               rc->t = w;
+               rc->service_name = service_name;
+               rc->service_details = service_details;
+               rc->from_parent_fd = from_parent_fd;
+               rc->master = NULL;
+               rc->worker = talloc_zero(rc, struct worker_restart_context);
+               if (rc->worker == NULL) {
+                       smb_panic("OOM allocating master restart context\n");
+               }
+               rc->worker->ev2 = ev2;
+               rc->worker->instance = pd->instances;
+               rc->worker->task = task;
+
+               fde = tevent_add_fd(
+                   ev, ev, fd, TEVENT_FD_READ, prefork_child_pipe_handler, rc);
+               if (fde == NULL) {
+                       smb_panic("Failed to add child pipe handler, "
+                                 "after fork");
+               }
+               tevent_fd_set_auto_close(fde);
+       } else {
+               /*
+                * tfork uses malloc
+                */
+               free(w);
+
+               TALLOC_FREE(ev);
+               setproctitle("task[%s] pre-forked worker(%d)",
+                            service_name,
+                            pd->instances);
+               prefork_reload_after_fork();
+               setup_handlers(ev2, from_parent_fd);
+               if (service_details->post_fork != NULL) {
+                       service_details->post_fork(task, pd);
+               }
+               tevent_loop_wait(ev2);
+               talloc_free(ev2);
+               exit(0);
+       }
+}
 /*
  * called to create a new server task
  */
@@ -251,12 +346,30 @@ static void prefork_new_task(
        if (pid != 0) {
                struct tevent_fd *fde = NULL;
                int fd = tfork_event_fd(t);
+               struct restart_context *rc = NULL;
 
                /* Register a pipe handler that gets called when the prefork
                 * master process terminates.
                 */
-               fde = tevent_add_fd(ev, ev, fd, TEVENT_FD_READ,
-                                   prefork_child_pipe_handler, t);
+               rc = talloc_zero(ev, struct restart_context);
+               if (rc == NULL) {
+                       smb_panic("OOM allocating restart context\n");
+               }
+               rc->t = t;
+               rc->service_name = service_name;
+               rc->service_details = service_details;
+               rc->from_parent_fd = from_parent_fd;
+               rc->master = talloc_zero(rc, struct master_restart_context);
+               if (rc->master == NULL) {
+                       smb_panic("OOM allocating master restart context\n");
+               }
+
+               rc->master->lp_ctx = lp_ctx;
+               rc->master->new_task_fn = new_task_fn;
+               rc->master->private_data = private_data;
+
+               fde = tevent_add_fd(
+                   ev, ev, fd, TEVENT_FD_READ, prefork_child_pipe_handler, rc);
                if (fde == NULL) {
                        smb_panic("Failed to add child pipe handler, "
                                  "after fork");
@@ -330,45 +443,14 @@ static void prefork_new_task(
         * We are now free to spawn some worker processes
         */
        for (i=0; i < num_children; i++) {
-               struct tfork* w = NULL;
-
-               w = tfork_create();
-               if (w == NULL) {
-                       smb_panic("failure in tfork\n");
-               }
-
-               pid = tfork_child_pid(w);
-               if (pid != 0) {
-                       struct tevent_fd *fde = NULL;
-                       int fd = tfork_event_fd(w);
-
-                       fde = tevent_add_fd(ev, ev, fd, TEVENT_FD_READ,
-                                           prefork_child_pipe_handler, w);
-                       if (fde == NULL) {
-                               smb_panic("Failed to add child pipe handler, "
-                                         "after fork");
-                       }
-                       tevent_fd_set_auto_close(fde);
-                       pd.instances++;
-               } else {
-                       /*
-                        * tfork uses malloc
-                        */
-                       free(w);
-
-                       TALLOC_FREE(ev);
-                       setproctitle("task[%s] pre-forked worker(%d)",
-                                    service_name,
-                                    pd.instances);
-                       prefork_reload_after_fork();
-                       setup_handlers(ev2, from_parent_fd);
-                       if (service_details->post_fork != NULL) {
-                               service_details->post_fork(task, &pd);
-                       }
-                       tevent_loop_wait(ev2);
-                       talloc_free(ev2);
-                       exit(0);
-               }
+               prefork_fork_worker(task,
+                                   ev,
+                                   ev2,
+                                   service_details,
+                                   service_name,
+                                   from_parent_fd,
+                                   &pd);
+               pd.instances++;
        }
 
        /* Don't listen on the sockets we just gave to the children */