udev: cleanup the udev cgroup when the daemon enters the idle state

4 files changed, 33 insertions, 23 deletions

diff --git a/NEWS b/NEWS
index 7984b6be94..52196dc0b1 100644
--- a/NEWS
+++ b/NEWS
@@ -1,7 +1,12 @@
 systemd System and Service Manager
 
 CHANGES WITH 182:
-        * udev: sources merged into the systemd sources
+        * udev: all udev sources are merged into the systemd source tree now.
+          All future udev development will happen in the systemd tree. It
+          is still fully supported to use the udev daemon and tools without
+          systemd running, like in initramfs or other init systems. Building
+          udev though, will require the *build* of the systemd tree, but
+          udev can be properly *run* without systems.
 
         * udev: /lib/udev/devices/ are not read anymore; tmpfiles should
           be used to create workarounds for broken subsystems.
@@ -10,6 +15,13 @@ CHANGES WITH 182:
           no longer supported. udev_monitor_new_from_netlink() needs to be
           used to subscribe to events.
 
+        * udev: when udevd is started by systemd, processes which are left
+          behind by forking them off of udev rules, are unconditionally cleaned
+          up and killed now after the event handling has finished. Services or
+          daemons must be started as systemd services. Services can be
+          pulled-in by udev to ge started, but they can no longer be directly
+          forked by udev rules.
+
         * systemd-logingctl and systemd-journalctl have been renamed
           to logingctl and journalctl to match systemctl.
 
diff --git a/TODO b/TODO
index 48591e4de1..1709b5e2c9 100644
--- a/TODO
+++ b/TODO
@@ -19,9 +19,6 @@ Features:
 
 * cg_create_and_attach() should fail for non-available controllers
 
-* udevd: SIGKILL all non-udevd processes in udev.service cgroup when entering idle
-  (the time to be able start services from udev rules is over on systemd systems)
-
 * udev: remove /sys and /dev configurability
 
 * udev: find a way to tell udev to not cancel firmware requests when running in initramfs
diff --git a/docs/gudev/gudev-docs.xml b/docs/gudev/gudev-docs.xml
index b40b61553f..4c3267998e 100644
--- a/docs/gudev/gudev-docs.xml
+++ b/docs/gudev/gudev-docs.xml
@@ -10,7 +10,7 @@
     <releaseinfo>For GUdev version &version;</releaseinfo>
 
     <copyright>
-      <year>2012</year>
+      <year>2009-2012</year>
       <holder>David Zeuthen &lt;davidz@redhat.com&gt;</holder>
       <holder>Bastien Nocera &lt;hadess@hadess.net&gt;</holder>
     </copyright>
diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index da044fcdcd..97b910cc2e 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -46,6 +46,7 @@
 
 #include "udev.h"
 #include "sd-daemon.h"
+#include "cgroup-util.h"
 
 static bool debug;
 
@@ -72,6 +73,7 @@ static int exec_delay;
 static sigset_t sigmask_orig;
 static UDEV_LIST(event_list);
 static UDEV_LIST(worker_list);
+char *udev_cgroup;
 static bool udev_exit;
 
 enum event_state {
@@ -452,22 +454,13 @@ static int event_queue_insert(struct udev_device *dev)
         return 0;
 }
 
-static void worker_kill(struct udev *udev, int retain)
+static void worker_kill(struct udev *udev)
 {
         struct udev_list_node *loop;
-        int max;
-
-        if (children <= retain)
-                return;
-
-        max = children - retain;
 
         udev_list_node_foreach(loop, &worker_list) {
                 struct worker *worker = node_to_worker(loop);
 
-                if (max-- <= 0)
-                        break;
-
                 if (worker->state == WORKER_KILLED)
                         continue;
 
@@ -635,7 +628,7 @@ static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
                 log_debug("udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
                 log_set_max_level(i);
                 udev_set_log_priority(udev, i);
-                worker_kill(udev, 0);
+                worker_kill(udev);
         }
 
         if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
@@ -677,7 +670,7 @@ static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
                         }
                         free(key);
                 }
-                worker_kill(udev, 0);
+                worker_kill(udev);
         }
 
         i = udev_ctrl_get_set_children_max(ctrl_msg);
@@ -1144,8 +1137,8 @@ int main(int argc, char *argv[])
                         break;
                 case 'D':
                         debug = true;
-                        if (udev_get_log_priority(udev) < LOG_INFO)
-                                udev_set_log_priority(udev, LOG_INFO);
+                        log_set_max_level(LOG_DEBUG);
+                        udev_set_log_priority(udev, LOG_INFO);
                         break;
                 case 'N':
                         if (strcmp (optarg, "early") == 0) {
@@ -1263,6 +1256,10 @@ int main(int argc, char *argv[])
                         rc = 3;
                         goto exit;
                 }
+
+                /* get our own cgroup, we regularly kill everything udev has left behind */
+                if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0)
+                        udev_cgroup = NULL;
         } else {
                 /* open control and netlink socket */
                 udev_ctrl = udev_ctrl_new(udev);
@@ -1480,7 +1477,7 @@ int main(int argc, char *argv[])
 
                         /* discard queued events and kill workers */
                         event_queue_cleanup(udev, EVENT_QUEUED);
-                        worker_kill(udev, 0);
+                        worker_kill(udev);
 
                         /* exit after all has cleaned up */
                         if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
@@ -1488,9 +1485,13 @@ int main(int argc, char *argv[])
 
                         /* timeout at exit for workers to finish */
                         timeout = 30 * 1000;
-                } else if (udev_list_node_is_empty(&event_list) && children <= 2) {
+                } else if (udev_list_node_is_empty(&event_list) && !children) {
                         /* we are idle */
                         timeout = -1;
+
+                        /* cleanup possible left-over processes in our cgroup */
+                        if (udev_cgroup)
+                                cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL);
                 } else {
                         /* kill idle or hanging workers */
                         timeout = 3 * 1000;
@@ -1511,7 +1512,7 @@ int main(int argc, char *argv[])
                         /* kill idle workers */
                         if (udev_list_node_is_empty(&event_list)) {
                                 log_debug("cleanup idle workers\n");
-                                worker_kill(udev, 2);
+                                worker_kill(udev);
                         }
 
                         /* check for hanging events */
@@ -1566,7 +1567,7 @@ int main(int argc, char *argv[])
 
                 /* reload requested, HUP signal received, rules changed, builtin changed */
                 if (reload) {
-                        worker_kill(udev, 0);
+                        worker_kill(udev);
                         rules = udev_rules_unref(rules);
                         udev_builtin_exit(udev);
                         reload = 0;