udevd: inotify - modernizations

[elogind.git] / src / udev / udevd.c

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 819ea3bb22ad0198292c5ef05b779a0ebaa4aa05..59b5568fb61753274d1d04c0b53adffb145535e0 100644 (file)
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -290,7 +290,19 @@ static void worker_new(struct event *event)
                          * acquired the lock, the external process will block until
                          * udev has finished its event handling.
                          */
-                        if (streq_ptr("block", udev_device_get_subsystem(dev))) {
+
+                        /*
+                         * <kabi_> since we make check - device seems unused - we try
+                         *         ioctl to deactivate - and device is found to be opened
+                         * <kay> sure, you try to take a write lock
+                         * <kay> if you get it udev is out
+                         * <kay> if you can't get it, udev is busy
+                         * <kabi_> we cannot deactivate openned device  (as it is in-use)
+                         * <kay> maybe we should just exclude dm from that thing entirely
+                         * <kabi_> IMHO this sounds like a good plan for this moment
+                         */
+                        if (streq_ptr("block", udev_device_get_subsystem(dev)) &&
+                            !startswith("dm-", udev_device_get_sysname(dev))) {
                                 struct udev_device *d = dev;
 
                                 if (streq_ptr("partition", udev_device_get_devtype(d)))
@@ -721,20 +733,30 @@ out:
         return udev_ctrl_connection_unref(ctrl_conn);
 }
 
+static void synthesize_change(struct udev_device *dev) {
+        char filename[UTIL_PATH_SIZE];
+
+        log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
+        strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
+        write_string_file(filename, "change");
+}
+
 /* read inotify messages */
 static int handle_inotify(struct udev *udev)
 {
         int nbytes, pos;
         char *buf;
         struct inotify_event *ev;
+        int r;
 
-        if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
-                return 0;
+        r = ioctl(fd_inotify, FIONREAD, &nbytes);
+        if (r < 0 || nbytes <= 0)
+                return -errno;
 
         buf = malloc(nbytes);
-        if (buf == NULL) {
+        if (!buf) {
                 log_error("error getting buffer for inotify");
-                return -1;
+                return -ENOMEM;
         }
 
         nbytes = read(fd_inotify, buf, nbytes);
@@ -744,27 +766,16 @@ static int handle_inotify(struct udev *udev)
 
                 ev = (struct inotify_event *)(buf + pos);
                 dev = udev_watch_lookup(udev, ev->wd);
-                if (dev != NULL) {
-                        log_debug("inotify event: %x for %s", ev->mask, udev_device_get_devnode(dev));
-                        if (ev->mask & IN_CLOSE_WRITE) {
-                                char filename[UTIL_PATH_SIZE];
-                                int fd;
-
-                                log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
-                                strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
-                                fd = open(filename, O_WRONLY|O_CLOEXEC);
-                                if (fd >= 0) {
-                                        if (write(fd, "change", 6) < 0)
-                                                log_debug("error writing uevent: %m");
-                                        close(fd);
-                                }
-                        }
-                        if (ev->mask & IN_IGNORED)
-                                udev_watch_end(udev, dev);
+                if (!dev)
+                        continue;
 
-                        udev_device_unref(dev);
-                }
+                log_debug("inotify event: %x for %s", ev->mask, udev_device_get_devnode(dev));
+                if (ev->mask & IN_CLOSE_WRITE)
+                        synthesize_change(dev);
+                else if (ev->mask & IN_IGNORED)
+                        udev_watch_end(udev, dev);
 
+                udev_device_unref(dev);
         }
 
         free(buf);