udevd: optionally watch device nodes with inotify

[elogind.git] / udev / udevd.c

diff --git a/udev/udevd.c b/udev/udevd.c
index d08cf30f29b806340f3e5099193fc831a607314d..d93781f411dfe07d73be21a629934078a810eaa2 100644 (file)
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -65,7 +65,6 @@ static int debug_trace;
 static struct udev_rules *rules;
 static struct udev_ctrl *udev_ctrl;
 static struct udev_monitor *kernel_monitor;
-static int inotify_fd = -1;
 static volatile int sigchilds_waiting;
 static volatile int udev_exit;
 static volatile int reload_config;
@@ -195,8 +194,6 @@ static void event_fork(struct udev_event *event)
                /* child */
                udev_monitor_unref(kernel_monitor);
                udev_ctrl_unref(udev_ctrl);
-               if (inotify_fd >= 0)
-                       close(inotify_fd);
                logging_close();
                logging_init("udevd-event");
                setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
@@ -513,6 +510,58 @@ static void handle_ctrl_msg(struct udev_ctrl *uctrl)
        udev_ctrl_msg_unref(ctrl_msg);
 }
 
+/* read inotify messages */
+static int handle_inotify(struct udev *udev)
+{
+       int nbytes, pos;
+       char *buf;
+       struct inotify_event *ev;
+       int reload_config = 0;
+
+       if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
+               return 0;
+
+       buf = malloc(nbytes);
+       if (buf == NULL) {
+               err(udev, "error getting buffer for inotify, disable watching\n");
+               close(inotify_fd);
+               inotify_fd = -1;
+               return 0;
+       }
+
+       read(inotify_fd, buf, nbytes);
+
+       for (pos = 0, ev = (struct inotify_event *)(buf + pos); pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
+               const char *syspath;
+
+               dbg(udev, "inotify event: %x for %d (%s)\n", ev->mask, ev->wd, ev->len ? ev->name : "*");
+
+               syspath = udev_watch_lookup(udev, ev->wd);
+               if (syspath != NULL) {
+                       dbg(udev, "inotify event: %x for %s\n", ev->mask, syspath);
+                       if (ev->mask & IN_CLOSE_WRITE) {
+                               char filename[UTIL_PATH_SIZE];
+                               int fd;
+
+                               info(udev, "device %s closed, synthesising write\n", syspath);
+                               util_strlcpy(filename, syspath, sizeof(filename));
+                               util_strlcat(filename, "/uevent", sizeof(filename));
+                               fd = open(filename, O_WRONLY);
+                               if (fd < 0 || write(fd, "change", 6) < 0)
+                                       info(udev, "error writing uevent: %m\n");
+                               close(fd);
+                       }
+                       if (ev->mask & IN_IGNORED)
+                               udev_watch_end(udev, ev->wd);
+               } else {
+                       reload_config = 1;
+               }
+       }
+
+       free (buf);
+       return reload_config;
+}
+
 static void asmlinkage sig_handler(int signum)
 {
        switch (signum) {
@@ -838,7 +887,7 @@ int main(int argc, char *argv[])
        sigaction(SIGHUP, &act, NULL);
 
        /* watch rules directory */
-       inotify_fd = inotify_init();
+       udev_watch_init(udev);
        if (inotify_fd >= 0) {
                if (udev_get_rules_path(udev) != NULL) {
                        inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
@@ -857,10 +906,9 @@ int main(int argc, char *argv[])
                        inotify_add_watch(inotify_fd, filename,
                                          IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
                }
-       } else if (errno == ENOSYS)
-               info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
-       else
-               err(udev, "inotify_init failed: %m\n");
+
+               udev_watch_restore(udev);
+       }
 
        /* in trace mode run one event after the other */
        if (debug_trace) {
@@ -936,24 +984,8 @@ int main(int argc, char *argv[])
                }
 
                /* rules directory inotify watch */
-               if (inotify_poll && (inotify_poll->revents & POLLIN)) {
-                       int nbytes;
-
-                       /* discard all possible events, we can just reload the config */
-                       if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
-                               char *buf;
-
-                               reload_config = 1;
-                               buf = malloc(nbytes);
-                               if (buf == NULL) {
-                                       err(udev, "error getting buffer for inotify, disable watching\n");
-                                       close(inotify_fd);
-                                       inotify_fd = -1;
-                               }
-                               read(inotify_fd, buf, nbytes);
-                               free(buf);
-                       }
-               }
+               if (inotify_poll && (inotify_poll->revents & POLLIN))
+                       reload_config = handle_inotify(udev);
 
 handle_signals:
                signal_received = 0;