2 * Copyright (C) 2004-2012 Kay Sievers <kay@vrfy.org>
3 * Copyright (C) 2009 Canonical Ltd.
4 * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <sys/types.h>
29 #include <sys/inotify.h>
33 static int inotify_fd = -1;
35 /* inotify descriptor, will be shared with rules directory;
36 * set to cloexec since we need our children to be able to add
39 int udev_watch_init(struct udev *udev) {
40 inotify_fd = inotify_init1(IN_CLOEXEC);
42 log_error_errno(errno, "inotify_init failed: %m");
46 /* move any old watches directory out of the way, and then restore
49 void udev_watch_restore(struct udev *udev) {
53 if (rename("/run/udev/watch", "/run/udev/watch.old") == 0) {
57 dir = opendir("/run/udev/watch.old");
59 log_error_errno(errno, "unable to open old watches dir /run/udev/watch.old; old watches will not be restored: %m");
63 for (ent = readdir(dir); ent != NULL; ent = readdir(dir)) {
64 char device[UTIL_PATH_SIZE];
66 struct udev_device *dev;
68 if (ent->d_name[0] == '.')
71 len = readlinkat(dirfd(dir), ent->d_name, device, sizeof(device));
72 if (len <= 0 || len == (ssize_t)sizeof(device))
76 dev = udev_device_new_from_device_id(udev, device);
80 log_debug("restoring old watch on '%s'", udev_device_get_devnode(dev));
81 udev_watch_begin(udev, dev);
82 udev_device_unref(dev);
84 unlinkat(dirfd(dir), ent->d_name, 0);
88 rmdir("/run/udev/watch.old");
90 } else if (errno != ENOENT) {
91 log_error_errno(errno, "unable to move watches dir /run/udev/watch; old watches will not be restored: %m");
95 void udev_watch_begin(struct udev *udev, struct udev_device *dev) {
96 char filename[UTIL_PATH_SIZE];
103 log_debug("adding watch on '%s'", udev_device_get_devnode(dev));
104 wd = inotify_add_watch(inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
106 log_error_errno(errno, "inotify_add_watch(%d, %s, %o) failed: %m",
107 inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
111 snprintf(filename, sizeof(filename), "/run/udev/watch/%d", wd);
112 mkdir_parents(filename, 0755);
114 r = symlink(udev_device_get_id_filename(dev), filename);
116 log_error_errno(errno, "Failed to create symlink %s: %m", filename);
118 udev_device_set_watch_handle(dev, wd);
121 void udev_watch_end(struct udev *udev, struct udev_device *dev) {
123 char filename[UTIL_PATH_SIZE];
128 wd = udev_device_get_watch_handle(dev);
132 log_debug("removing watch on '%s'", udev_device_get_devnode(dev));
133 inotify_rm_watch(inotify_fd, wd);
135 snprintf(filename, sizeof(filename), "/run/udev/watch/%d", wd);
138 udev_device_set_watch_handle(dev, -1);
141 struct udev_device *udev_watch_lookup(struct udev *udev, int wd) {
142 char filename[UTIL_PATH_SIZE];
143 char device[UTIL_NAME_SIZE];
146 if (inotify_fd < 0 || wd < 0)
149 snprintf(filename, sizeof(filename), "/run/udev/watch/%d", wd);
150 len = readlink(filename, device, sizeof(device));
151 if (len <= 0 || (size_t)len == sizeof(device))
155 return udev_device_new_from_device_id(udev, device);