udevd: close race in udev settle

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 18 insertions, 10 deletions

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 48f2dec35f..daa95ba127 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -292,7 +292,7 @@ static void worker_new(struct event *event) {
                                         fd_lock = open(udev_device_get_devnode(d), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
                                         if (fd_lock >= 0 && flock(fd_lock, LOCK_SH|LOCK_NB) < 0) {
                                                 log_debug_errno(errno, "Unable to flock(%s), skipping event handling: %m", udev_device_get_devnode(d));
-                                                err = -EWOULDBLOCK;
+                                                err = -EAGAIN;
                                                 fd_lock = safe_close(fd_lock);
                                                 goto skip;
                                         }
@@ -899,6 +899,17 @@ static void handle_signal(struct udev *udev, int signo) {
         }
 }
 
+static void event_queue_update(void) {
+        if (!udev_list_node_is_empty(&event_list)) {
+                int fd;
+
+                fd = open("/run/udev/queue", O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
+                if (fd >= 0)
+                       close(fd);
+        } else
+                unlink("/run/udev/queue");
+}
+
 /*
  * read the kernel command line, in case we need to get into debug mode
  *   udev.log-priority=<level>              syslog priority
@@ -1312,15 +1323,7 @@ int main(int argc, char *argv[]) {
                 }
 
                 /* tell settle that we are busy or idle */
-                if (!udev_list_node_is_empty(&event_list)) {
-                        int fd;
-
-                        fd = open("/run/udev/queue", O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
-                        if (fd >= 0)
-                                close(fd);
-                } else {
-                        unlink("/run/udev/queue");
-                }
+                event_queue_update();
 
                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout);
                 if (fdcount < 0)
@@ -1445,6 +1448,11 @@ int main(int argc, char *argv[]) {
                 if (is_inotify)
                         handle_inotify(udev);
 
+                /* tell settle that we are busy or idle, this needs to be before the
+                 * PING handling
+                 */
+                event_queue_update();
+
                 /*
                  * This needs to be after the inotify handling, to make sure,
                  * that the ping is send back after the possibly generated