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git.ipfire.org Git - thirdparty/systemd.git/blob - src/udev/udev-watch.c
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
)
41 inotify_fd
= inotify_init1(IN_CLOEXEC
);
43 log_error("inotify_init failed: %m\n");
47 /* move any old watches directory out of the way, and then restore
50 void udev_watch_restore(struct udev
*udev
)
55 if (rename("/run/udev/watch", "/run/udev/watch.old") == 0) {
59 dir
= opendir("/run/udev/watch.old");
61 log_error("unable to open old watches dir /run/udev/watch.old; old watches will not be restored: %m");
65 for (ent
= readdir(dir
); ent
!= NULL
; ent
= readdir(dir
)) {
66 char device
[UTIL_PATH_SIZE
];
68 struct udev_device
*dev
;
70 if (ent
->d_name
[0] == '.')
73 len
= readlinkat(dirfd(dir
), ent
->d_name
, device
, sizeof(device
));
74 if (len
<= 0 || len
== (ssize_t
)sizeof(device
))
78 dev
= udev_device_new_from_device_id(udev
, device
);
82 log_debug("restoring old watch on '%s'\n", udev_device_get_devnode(dev
));
83 udev_watch_begin(udev
, dev
);
84 udev_device_unref(dev
);
86 unlinkat(dirfd(dir
), ent
->d_name
, 0);
90 rmdir("/run/udev/watch.old");
92 } else if (errno
!= ENOENT
) {
93 log_error("unable to move watches dir /run/udev/watch; old watches will not be restored: %m");
97 void udev_watch_begin(struct udev
*udev
, struct udev_device
*dev
)
99 char filename
[UTIL_PATH_SIZE
];
106 log_debug("adding watch on '%s'\n", udev_device_get_devnode(dev
));
107 wd
= inotify_add_watch(inotify_fd
, udev_device_get_devnode(dev
), IN_CLOSE_WRITE
);
109 log_error("inotify_add_watch(%d, %s, %o) failed: %m\n",
110 inotify_fd
, udev_device_get_devnode(dev
), IN_CLOSE_WRITE
);
114 snprintf(filename
, sizeof(filename
), "/run/udev/watch/%d", wd
);
115 mkdir_parents(filename
, 0755);
117 r
= symlink(udev_device_get_id_filename(dev
), filename
);
119 log_error("Failed to create symlink %s: %m", filename
);
121 udev_device_set_watch_handle(dev
, wd
);
124 void udev_watch_end(struct udev
*udev
, struct udev_device
*dev
)
127 char filename
[UTIL_PATH_SIZE
];
132 wd
= udev_device_get_watch_handle(dev
);
136 log_debug("removing watch on '%s'\n", udev_device_get_devnode(dev
));
137 inotify_rm_watch(inotify_fd
, wd
);
139 snprintf(filename
, sizeof(filename
), "/run/udev/watch/%d", wd
);
142 udev_device_set_watch_handle(dev
, -1);
145 struct udev_device
*udev_watch_lookup(struct udev
*udev
, int wd
)
147 char filename
[UTIL_PATH_SIZE
];
148 char device
[UTIL_NAME_SIZE
];
151 if (inotify_fd
< 0 || wd
< 0)
154 snprintf(filename
, sizeof(filename
), "/run/udev/watch/%d", wd
);
155 len
= readlink(filename
, device
, sizeof(device
));
156 if (len
<= 0 || (size_t)len
== sizeof(device
))
160 return udev_device_new_from_device_id(udev
, device
);