logind: properly clean up user cgroups when they run empty

4 files changed, 70 insertions, 12 deletions

diff --git a/src/login/logind-session.c b/src/login/logind-session.c
index 5c8d54931..58514ea0d 100644
--- a/src/login/logind-session.c
+++ b/src/login/logind-session.c
@@ -85,13 +85,13 @@ void session_free(Session *s) {
                         s->seat->active = NULL;
 
                 LIST_REMOVE(Session, sessions_by_seat, s->seat->sessions, s);
         }
 
         if (s->cgroup_path)
-                hashmap_remove(s->manager->cgroups, s->cgroup_path);
+                hashmap_remove(s->manager->session_cgroups, s->cgroup_path);
 
         free(s->cgroup_path);
         strv_free(s->controllers);
 
         free(s->tty);
         free(s->display);
@@ -524,13 +524,13 @@ static int session_create_cgroup(Session *s) {
                         if (r < 0)
                                 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
 
                 }
         }
 
-        hashmap_put(s->manager->cgroups, s->cgroup_path, s);
+        hashmap_put(s->manager->session_cgroups, s->cgroup_path, s);
 
         return 0;
 }
 
 int session_start(Session *s) {
         int r;
@@ -643,13 +643,13 @@ static int session_terminate_cgroup(Session *s) {
                 }
         }
 
         STRV_FOREACH(k, s->user->manager->controllers)
                 cg_trim(*k, s->cgroup_path, true);
 
-        hashmap_remove(s->manager->cgroups, s->cgroup_path);
+        hashmap_remove(s->manager->session_cgroups, s->cgroup_path);
 
         free(s->cgroup_path);
         s->cgroup_path = NULL;
 
         return 0;
 }
diff --git a/src/login/logind-user.c b/src/login/logind-user.c
index b971845e1..8bd773086 100644
--- a/src/login/logind-user.c
+++ b/src/login/logind-user.c
@@ -72,12 +72,14 @@ void user_free(User *u) {
         if (u->in_gc_queue)
                 LIST_REMOVE(User, gc_queue, u->manager->user_gc_queue, u);
 
         while (u->sessions)
                 session_free(u->sessions);
 
+        if (u->cgroup_path)
+                hashmap_remove(u->manager->user_cgroups, u->cgroup_path);
         free(u->cgroup_path);
 
         free(u->service);
         free(u->runtime_path);
 
         hashmap_remove(u->manager->users, ULONG_TO_PTR((unsigned long) u->uid));
@@ -310,12 +312,14 @@ static int user_create_cgroup(User *u) {
 
                 r = cg_create(*k, p);
                 if (r < 0)
                         log_warning("Failed to create cgroup %s:%s: %s", *k, p, strerror(-r));
         }
 
+        hashmap_put(u->manager->user_cgroups, u->cgroup_path, u);
+
         return 0;
 }
 
 static int user_start_service(User *u) {
         assert(u);
 
@@ -414,12 +418,14 @@ static int user_terminate_cgroup(User *u) {
                         r = -EBUSY;
         }
 
         STRV_FOREACH(k, u->manager->controllers)
                 cg_trim(*k, u->cgroup_path, true);
 
+        hashmap_remove(u->manager->user_cgroups, u->cgroup_path);
+
         free(u->cgroup_path);
         u->cgroup_path = NULL;
 
         return r;
 }
 
diff --git a/src/login/logind.c b/src/login/logind.c
index 632987c8b..62f7914fe 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -61,19 +61,22 @@ Manager *manager_new(void) {
         m->seats = hashmap_new(string_hash_func, string_compare_func);
         m->sessions = hashmap_new(string_hash_func, string_compare_func);
         m->users = hashmap_new(trivial_hash_func, trivial_compare_func);
         m->inhibitors = hashmap_new(string_hash_func, string_compare_func);
         m->buttons = hashmap_new(string_hash_func, string_compare_func);
 
-        m->cgroups = hashmap_new(string_hash_func, string_compare_func);
+        m->user_cgroups = hashmap_new(string_hash_func, string_compare_func);
+        m->session_cgroups = hashmap_new(string_hash_func, string_compare_func);
+
         m->session_fds = hashmap_new(trivial_hash_func, trivial_compare_func);
         m->inhibitor_fds = hashmap_new(trivial_hash_func, trivial_compare_func);
         m->button_fds = hashmap_new(trivial_hash_func, trivial_compare_func);
 
         if (!m->devices || !m->seats || !m->sessions || !m->users || !m->inhibitors || !m->buttons ||
-            !m->cgroups || !m->session_fds || !m->inhibitor_fds || !m->button_fds) {
+            !m->user_cgroups || !m->session_cgroups ||
+            !m->session_fds || !m->inhibitor_fds || !m->button_fds) {
                 manager_free(m);
                 return NULL;
         }
 
         m->reset_controllers = strv_new("cpu", NULL);
         m->kill_exclude_users = strv_new("root", NULL);
@@ -128,13 +131,15 @@ void manager_free(Manager *m) {
         hashmap_free(m->seats);
         hashmap_free(m->sessions);
         hashmap_free(m->users);
         hashmap_free(m->inhibitors);
         hashmap_free(m->buttons);
 
-        hashmap_free(m->cgroups);
+        hashmap_free(m->user_cgroups);
+        hashmap_free(m->session_cgroups);
+
         hashmap_free(m->session_fds);
         hashmap_free(m->inhibitor_fds);
         hashmap_free(m->button_fds);
 
         if (m->console_active_fd >= 0)
                 close_nointr_nofail(m->console_active_fd);
@@ -1005,13 +1010,13 @@ int manager_get_session_by_cgroup(Manager *m, const char *cgroup, Session **sess
         char *p;
 
         assert(m);
         assert(cgroup);
         assert(session);
 
-        s = hashmap_get(m->cgroups, cgroup);
+        s = hashmap_get(m->session_cgroups, cgroup);
         if (s) {
                 *session = s;
                 return 1;
         }
 
         p = strdup(cgroup);
@@ -1029,21 +1034,62 @@ int manager_get_session_by_cgroup(Manager *m, const char *cgroup, Session **sess
                         *session = NULL;
                         return 0;
                 }
 
                 *e = 0;
 
-                s = hashmap_get(m->cgroups, p);
+                s = hashmap_get(m->session_cgroups, p);
                 if (s) {
                         free(p);
                         *session = s;
                         return 1;
                 }
         }
 }
 
+int manager_get_user_by_cgroup(Manager *m, const char *cgroup, User **user) {
+        User *u;
+        char *p;
+
+        assert(m);
+        assert(cgroup);
+        assert(user);
+
+        u = hashmap_get(m->user_cgroups, cgroup);
+        if (u) {
+                *user = u;
+                return 1;
+        }
+
+        p = strdup(cgroup);
+        if (!p) {
+                log_error("Out of memory.");
+                return -ENOMEM;
+        }
+
+        for (;;) {
+                char *e;
+
+                e = strrchr(p, '/');
+                if (!e || e == p) {
+                        free(p);
+                        *user = NULL;
+                        return 0;
+                }
+
+                *e = 0;
+
+                u = hashmap_get(m->user_cgroups, p);
+                if (u) {
+                        free(p);
+                        *user = u;
+                        return 1;
+                }
+        }
+}
+
 int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session) {
         char *p;
         int r;
 
         assert(m);
         assert(pid >= 1);
@@ -1058,19 +1104,22 @@ int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session) {
 
         return r;
 }
 
 void manager_cgroup_notify_empty(Manager *m, const char *cgroup) {
         Session *s;
+        User *u;
         int r;
 
         r = manager_get_session_by_cgroup(m, cgroup, &s);
-        if (r <= 0)
-                return;
+        if (r > 0)
+                session_add_to_gc_queue(s);
 
-        session_add_to_gc_queue(s);
+        r = manager_get_user_by_cgroup(m, cgroup, &u);
+        if (r > 0)
+                user_add_to_gc_queue(u);
 }
 
 static void manager_dispatch_other(Manager *m, int fd) {
         Session *s;
         Inhibitor *i;
         Button *b;
diff --git a/src/login/logind.h b/src/login/logind.h
index 6fcef6f31..5e828bf01 100644
--- a/src/login/logind.h
+++ b/src/login/logind.h
@@ -78,13 +78,15 @@ struct Manager {
 
         bool kill_user_processes;
 
         unsigned long session_counter;
         unsigned long inhibit_counter;
 
-        Hashmap *cgroups;
+        Hashmap *session_cgroups;
+        Hashmap *user_cgroups;
+
         Hashmap *session_fds;
         Hashmap *inhibitor_fds;
         Hashmap *button_fds;
 
         /* If a shutdown was delayed due to a inhibitor this contains
            the unit name we are supposed to start after the delay is
@@ -143,12 +145,13 @@ int manager_spawn_autovt(Manager *m, int vtnr);
 void manager_cgroup_notify_empty(Manager *m, const char *cgroup);
 
 void manager_gc(Manager *m, bool drop_not_started);
 
 int manager_get_idle_hint(Manager *m, dual_timestamp *t);
 
+int manager_get_user_by_cgroup(Manager *m, const char *cgroup, User **user);
 int manager_get_session_by_cgroup(Manager *m, const char *cgroup, Session **session);
 int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session);
 
 extern const DBusObjectPathVTable bus_manager_vtable;
 
 DBusHandlerResult bus_message_filter(DBusConnection *c, DBusMessage *message, void *userdata);