2 * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@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)
41 inotify_fd = inotify_init();
43 util_set_fd_cloexec(inotify_fd);
45 err(udev, "inotify_init failed: %m\n");
49 /* move any old watches directory out of the way, and then restore
52 void udev_watch_restore(struct udev *udev)
54 char filename[UTIL_PATH_SIZE], oldname[UTIL_PATH_SIZE];
59 util_strscpyl(oldname, sizeof(oldname), udev_get_dev_path(udev), "/.udev/watch.old", NULL);
60 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/watch", NULL);
61 if (rename(filename, oldname) == 0) {
65 dir = opendir(oldname);
67 err(udev, "unable to open old watches dir '%s', old watches will not be restored: %m", oldname);
71 for (ent = readdir(dir); ent != NULL; ent = readdir(dir)) {
72 char device[UTIL_PATH_SIZE];
76 struct udev_device *dev;
78 if (ent->d_name[0] < '0' || ent->d_name[0] > '9')
82 l = util_strpcpy(&s, sizeof(device), udev_get_sys_path(udev));
83 len = readlinkat(dirfd(dir), ent->d_name, s, l);
84 if (len <= 0 || len >= (ssize_t)l) {
85 unlinkat(dirfd(dir), ent->d_name, 0);
89 dbg(udev, "old watch to '%s' found\n", device);
90 dev = udev_device_new_from_syspath(udev, device);
92 unlinkat(dirfd(dir), ent->d_name, 0);
96 info(udev, "restoring old watch on '%s'\n", udev_device_get_devnode(dev));
97 udev_watch_begin(udev, dev);
99 udev_device_unref(dev);
100 unlinkat(dirfd(dir), ent->d_name, 0);
106 } else if (errno != ENOENT) {
107 err(udev, "unable to move watches dir '%s', old watches will not be restored: %m", filename);
111 void udev_watch_begin(struct udev *udev, struct udev_device *dev)
113 char filename[UTIL_PATH_SIZE];
119 info(udev, "adding watch on '%s'\n", udev_device_get_devnode(dev));
120 wd = inotify_add_watch(inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
122 err(udev, "inotify_add_watch(%d, %s, %o) failed: %m\n",
123 inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
127 snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
128 util_create_path(udev, filename);
130 symlink(udev_device_get_devpath(dev), filename);
132 udev_device_set_watch_handle(dev, wd);
135 void udev_watch_end(struct udev *udev, struct udev_device *dev)
138 char filename[UTIL_PATH_SIZE];
143 wd = udev_device_get_watch_handle(dev);
147 info(udev, "removing watch on '%s'\n", udev_device_get_devnode(dev));
148 inotify_rm_watch(inotify_fd, wd);
150 snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
153 udev_device_set_watch_handle(dev, -1);
156 struct udev_device *udev_watch_lookup(struct udev *udev, int wd)
158 char filename[UTIL_PATH_SIZE];
159 char syspath[UTIL_PATH_SIZE];
164 if (inotify_fd < 0 || wd < 0)
167 snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
169 l = util_strpcpy(&s, sizeof(syspath), udev_get_sys_path(udev));
170 len = readlink(filename, s, l);
171 if (len < 0 || (size_t)len >= l)
174 return udev_device_new_from_syspath(udev, syspath);