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 7984b6be9..52196dc0b 100644
--- a/NEWS
+++ b/NEWS
@@ -3,3 +3,8 @@ 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.
 
@@ -12,2 +17,9 @@ CHANGES WITH 182:
 
+        * 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
diff --git a/TODO b/TODO
index 48591e4de..1709b5e2c 100644
--- a/TODO
+++ b/TODO
@@ -21,5 +21,2 @@ Features:
 
-* 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
diff --git a/docs/gudev/gudev-docs.xml b/docs/gudev/gudev-docs.xml
index b40b61553..4c3267998 100644
--- a/docs/gudev/gudev-docs.xml
+++ b/docs/gudev/gudev-docs.xml
@@ -12,3 +12,3 @@
     <copyright>
-      <year>2012</year>
+      <year>2009-2012</year>
       <holder>David Zeuthen &lt;davidz@redhat.com&gt;</holder>
diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index da044fcdc..97b910cc2 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -48,2 +48,3 @@
 #include "sd-daemon.h"
+#include "cgroup-util.h"
 
@@ -74,2 +75,3 @@ static UDEV_LIST(event_list);
 static UDEV_LIST(worker_list);
+char *udev_cgroup;
 static bool udev_exit;
@@ -454,11 +456,5 @@ static int event_queue_insert(struct udev_device *dev)
 
-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;
 
@@ -467,5 +463,2 @@ static void worker_kill(struct udev *udev, int retain)
 
-                if (max-- <= 0)
-                        break;
-
                 if (worker->state == WORKER_KILLED)
@@ -637,3 +630,3 @@ static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
                 udev_set_log_priority(udev, i);
-                worker_kill(udev, 0);
+                worker_kill(udev);
         }
@@ -679,3 +672,3 @@ static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
                 }
-                worker_kill(udev, 0);
+                worker_kill(udev);
         }
@@ -1146,4 +1139,4 @@ int main(int argc, char *argv[])
                         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;
@@ -1265,2 +1258,6 @@ int main(int argc, char *argv[])
                 }
+
+                /* 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 {
@@ -1482,3 +1479,3 @@ int main(int argc, char *argv[])
                         event_queue_cleanup(udev, EVENT_QUEUED);
-                        worker_kill(udev, 0);
+                        worker_kill(udev);
 
@@ -1490,5 +1487,9 @@ int main(int argc, char *argv[])
                         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 {
@@ -1513,3 +1514,3 @@ int main(int argc, char *argv[])
                                 log_debug("cleanup idle workers\n");
-                                worker_kill(udev, 2);
+                                worker_kill(udev);
                         }
@@ -1568,3 +1569,3 @@ int main(int argc, char *argv[])
                 if (reload) {
-                        worker_kill(udev, 0);
+                        worker_kill(udev);
                         rules = udev_rules_unref(rules);