source4 smbd prefork: Restart failed processes

[samba.git] / source4 / smbd / process_prefork.c

diff --git a/source4/smbd/process_prefork.c b/source4/smbd/process_prefork.c
index c8ed942b7413458019632c7ec9450e392900dd47..4423b4674e4880736e3bf38204e1300992c074dd 100644 (file)
--- a/source4/smbd/process_prefork.c
+++ b/source4/smbd/process_prefork.c
@@ -36,6 +36,25 @@
 #include "lib/util/tfork.h"
 
 NTSTATUS process_model_prefork_init(void);
+static void prefork_new_task(
+    struct tevent_context *ev,
+    struct loadparm_context *lp_ctx,
+    const char *service_name,
+    struct task_server *(*new_task_fn)(struct tevent_context *,
+                                      struct loadparm_context *lp_ctx,
+                                      struct server_id,
+                                      void *,
+                                      void *),
+    void *private_data,
+    const struct service_details *service_details,
+    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 control_pipe[2],
+                               struct process_details *pd);
 
 /*
  * State needed to restart the master process or a worker process if they
@@ -55,6 +74,7 @@ struct worker_restart_context {
        unsigned int instance;
        struct task_server *task;
        struct tevent_context *ev2;
+       int control_pipe[2];
 };
 
 struct restart_context {
@@ -164,6 +184,39 @@ static void prefork_child_pipe_handler(struct tevent_context *ev,
                status = WTERMSIG(status);
                DBG_ERR("Parent %d, Child %d terminated with signal %d\n",
                        getpid(), pid, status);
+               if (status == SIGABRT || status == SIGBUS || status == SIGFPE ||
+                   status == SIGILL || status == SIGSYS) {
+                       /*
+                        * Lets restart the process.
+                        *
+                        */
+                       tfork_destroy(&rc->t);
+                       if (rc->master != NULL) {
+                               DBG_ERR("Restarting [%s] pre-fork master\n",
+                                       rc->service_name);
+                               prefork_new_task(ev,
+                                                rc->master->lp_ctx,
+                                                rc->service_name,
+                                                rc->master->new_task_fn,
+                                                rc->master->private_data,
+                                                rc->service_details,
+                                                rc->from_parent_fd);
+                       } else if (rc->worker != NULL) {
+                               struct process_details pd =
+                                   initial_process_details;
+                               DBG_ERR("Restarting [%s] pre-fork worker(%d)\n",
+                                       rc->service_name,
+                                       rc->worker->instance);
+                               pd.instances = rc->worker->instance;
+                               prefork_fork_worker(rc->worker->task,
+                                                   ev,
+                                                   rc->worker->ev2,
+                                                   rc->service_details,
+                                                   rc->service_name,
+                                                   rc->worker->control_pipe,
+                                                   &pd);
+                       }
+               }
        }
        /* tfork allocates tfork structures with malloc */
        free(rc->t);
@@ -254,7 +307,7 @@ static void prefork_fork_worker(struct task_server *task,
                                struct tevent_context *ev2,
                                const struct service_details *service_details,
                                const char *service_name,
-                               int from_parent_fd,
+                               int control_pipe[2],
                                struct process_details *pd)
 {
        struct tfork *w = NULL;
@@ -278,7 +331,6 @@ static void prefork_fork_worker(struct task_server *task,
                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) {
@@ -287,6 +339,8 @@ static void prefork_fork_worker(struct task_server *task,
                rc->worker->ev2 = ev2;
                rc->worker->instance = pd->instances;
                rc->worker->task = task;
+               rc->worker->control_pipe[0] = control_pipe[0];
+               rc->worker->control_pipe[1] = control_pipe[1];
 
                fde = tevent_add_fd(
                    ev, ev, fd, TEVENT_FD_READ, prefork_child_pipe_handler, rc);
@@ -296,6 +350,8 @@ static void prefork_fork_worker(struct task_server *task,
                }
                tevent_fd_set_auto_close(fde);
        } else {
+               close(control_pipe[1]);
+               setup_handlers(ev2, control_pipe[0]);
                /*
                 * tfork uses malloc
                 */
@@ -306,7 +362,6 @@ static void prefork_fork_worker(struct task_server *task,
                             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);
                }
@@ -336,12 +391,14 @@ static void prefork_new_task(
        struct tevent_context *ev2;
        struct task_server *task = NULL;
        struct process_details pd = initial_process_details;
+       int control_pipe[2];
 
        t = tfork_create();
        if (t == NULL) {
                smb_panic("failure in tfork\n");
        }
 
+       DBG_NOTICE("Forking [%s] pre-fork master process\n", service_name);
        pid = tfork_child_pid(t);
        if (pid != 0) {
                struct tevent_fd *fde = NULL;
@@ -439,6 +496,16 @@ static void prefork_new_task(
        }
        DBG_NOTICE("Forking %d %s worker processes\n",
                   num_children, service_name);
+       {
+               int ret;
+               ret = pipe(control_pipe);
+               if (ret != 0) {
+                       smb_panic("Unable to create worker control pipe\n");
+               }
+               smb_set_close_on_exec(control_pipe[0]);
+               smb_set_close_on_exec(control_pipe[1]);
+       }
+
        /*
         * We are now free to spawn some worker processes
         */
@@ -448,7 +515,7 @@ static void prefork_new_task(
                                    ev2,
                                    service_details,
                                    service_name,
-                                   from_parent_fd,
+                                   control_pipe,
                                    &pd);
                pd.instances++;
        }