cgroup: honour sticky bit when trimming cgroup trees

[elogind.git] / src / user-sessions.c

diff --git a/src/user-sessions.c b/src/user-sessions.c
index dc4ee0fb4ac402a7c3332777b864f994812e4799..df46b76c872842597597e1661da4b7e29ec1a329 100644 (file)
--- a/src/user-sessions.c
+++ b/src/user-sessions.c
@@ -39,27 +39,53 @@ int main(int argc, char*argv[]) {
         log_parse_environment();
         log_open();
 
+        umask(0022);
+
         if (streq(argv[1], "start")) {
+                int q = 0, r = 0;
+
+                if (unlink("/run/nologin") < 0 && errno != ENOENT) {
+                        log_error("Failed to remove /run/nologin file: %m");
+                        r = -errno;
+                }
+
+                if (unlink("/etc/nologin") < 0 && errno != ENOENT) {
 
-                if (unlink("/var/run/nologin") < 0 ||
-                    unlink("/etc/nologin") < 0) {
+                        /* If the file doesn't exist and /etc simply
+                         * was read-only (in which case unlink()
+                         * returns EROFS even if the file doesn't
+                         * exist), don't complain */
 
-                        if (errno != ENOENT) {
-                                log_error("Failed to remove nologin files: %m");
-                                goto finish;
+                        if (errno != EROFS || access("/etc/nologin", F_OK) >= 0) {
+                                log_error("Failed to remove /etc/nologin file: %m");
+                                q = -errno;
                         }
                 }
 
+                if (r < 0 || q < 0)
+                        goto finish;
+
         } else if (streq(argv[1], "stop")) {
                 int r, q;
+                char *cgroup_user_tree = NULL;
 
-                if ((r = write_one_line_file("/var/run/nologin", "System is going down.")) < 0)
-                        log_error("Failed to create /var/run/nologin: %s", strerror(-r));
+                if ((r = write_one_line_file_atomic("/run/nologin", "System is going down.")) < 0)
+                        log_error("Failed to create /run/nologin: %s", strerror(-r));
 
-                if ((q = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, "/user", true)) < 0)
+                if ((q = cg_get_user_path(&cgroup_user_tree)) < 0) {
+                        log_error("Failed to determine use path: %s", strerror(-q));
+                        goto finish;
+                }
+
+                q = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, cgroup_user_tree, true);
+                free(cgroup_user_tree);
+
+                if (q < 0) {
                         log_error("Failed to kill sessions: %s", strerror(-q));
+                        goto finish;
+                }
 
-                if (r < 0 || q < 0)
+                if (r < 0)
                         goto finish;
 
         } else {