1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dir-watch-inotify.c OS specific directory change notification for message bus
4 * Copyright (C) 2003 Red Hat, Inc.
7 * Licensed under the Academic Free License version 2.1
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 /* Be careful, this file is not Linux-only: QNX also uses it */
32 /* QNX's inotify is broken, and requires stdint.h to be manually included first */
34 #include <sys/inotify.h>
35 #include <sys/types.h>
39 #include <dbus/dbus-internals.h>
40 #include <dbus/dbus-list.h>
41 #include <dbus/dbus-sysdeps-unix.h>
42 #include <dbus/dbus-watch.h>
43 #include "dir-watch.h"
45 #define MAX_DIRS_TO_WATCH 128
46 #define INOTIFY_EVENT_SIZE (sizeof(struct inotify_event))
47 #define INOTIFY_BUF_LEN (1024 * (INOTIFY_EVENT_SIZE + 16))
49 /* use a static array to avoid handling OOM */
50 static int wds[MAX_DIRS_TO_WATCH];
51 static char *dirs[MAX_DIRS_TO_WATCH];
52 static int num_wds = 0;
53 static int inotify_fd = -1;
54 static DBusWatch *watch = NULL;
55 static DBusLoop *loop = NULL;
58 _handle_inotify_watch (DBusWatch *passed_watch, unsigned int flags, void *data)
60 char buffer[INOTIFY_BUF_LEN];
62 #ifdef DBUS_ENABLE_VERBOSE_MODE
66 ret = read (inotify_fd, buffer, INOTIFY_BUF_LEN);
68 _dbus_verbose ("Error reading inotify event: '%s'\n", _dbus_strerror(errno));
70 _dbus_verbose ("Error reading inotify event: buffer too small\n");
73 _dbus_verbose ("Sending SIGHUP signal on reception of %ld inotify event(s)\n", (long) ret);
74 (void) kill (_dbus_getpid (), SIGHUP);
77 #ifdef DBUS_ENABLE_VERBOSE_MODE
80 struct inotify_event *ev;
82 ev = (struct inotify_event *) &buffer[i];
83 i += INOTIFY_EVENT_SIZE + ev->len;
85 _dbus_verbose ("event name: '%s'\n", ev->name);
86 _dbus_verbose ("inotify event: wd=%d mask=%u cookie=%u len=%u\n", ev->wd, ev->mask, ev->cookie, ev->len);
96 _set_watched_dirs_internal (DBusList **directories)
98 int new_wds[MAX_DIRS_TO_WATCH];
99 char *new_dirs[MAX_DIRS_TO_WATCH];
103 for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
110 link = _dbus_list_get_first_link (directories);
113 new_dirs[i++] = (char *)link->data;
114 link = _dbus_list_get_next_link (directories, link);
117 /* Look for directories in both the old and new sets, if
118 * we find one, move its data into the new set.
120 for (i = 0; new_dirs[i]; i++)
122 for (j = 0; j < num_wds; j++)
124 if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0)
127 new_dirs[i] = dirs[j];
135 /* Any directories we find in "wds" with a nonzero fd must
136 * not be in the new set, so perform cleanup now.
138 for (j = 0; j < num_wds; j++)
142 inotify_rm_watch (inotify_fd, wds[j]);
149 for (i = 0; new_dirs[i]; i++)
151 if (new_wds[i] == -1)
153 /* FIXME - less lame error handling for failing to add a watch; we may need to sleep. */
154 wd = inotify_add_watch (inotify_fd, new_dirs[i], IN_CLOSE_WRITE | IN_DELETE | IN_MOVED_TO | IN_MOVED_FROM);
157 /* Not all service directories need to exist. */
160 _dbus_warn ("Cannot setup inotify for '%s'; error '%s'", new_dirs[i], _dbus_strerror (errno));
171 new_dirs[i] = _dbus_strdup (new_dirs[i]);
174 /* FIXME have less lame handling for OOM, we just silently fail to
175 * watch. (In reality though, the whole OOM handling in dbus is stupid
176 * but we won't go into that in this comment =) )
178 inotify_rm_watch (inotify_fd, wd);
186 for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
189 dirs[i] = new_dirs[i];
197 _shutdown_inotify (void *data)
199 DBusList *empty = NULL;
201 if (inotify_fd == -1)
204 _set_watched_dirs_internal (&empty);
208 _dbus_loop_remove_watch (loop, watch);
209 _dbus_watch_invalidate (watch);
210 _dbus_watch_unref (watch);
211 _dbus_loop_unref (loop);
221 _init_inotify (BusContext *context)
225 if (inotify_fd == -1)
227 #ifdef HAVE_INOTIFY_INIT1
228 inotify_fd = inotify_init1 (IN_CLOEXEC);
229 /* This ensures we still run on older Linux kernels.
230 * https://bugs.freedesktop.org/show_bug.cgi?id=23957
233 inotify_fd = inotify_init ();
235 inotify_fd = inotify_init ();
239 _dbus_warn ("Cannot initialize inotify");
243 /* In the inotify_init1 case this is unnecessary but harmless,
244 * in the other cases it's necessary */
245 _dbus_fd_set_close_on_exec (inotify_fd);
247 loop = bus_context_get_loop (context);
248 _dbus_loop_ref (loop);
250 watch = _dbus_watch_new (inotify_fd, DBUS_WATCH_READABLE, TRUE,
251 _handle_inotify_watch, NULL, NULL);
255 _dbus_warn ("Unable to create inotify watch");
259 if (!_dbus_loop_add_watch (loop, watch))
261 _dbus_warn ("Unable to add reload watch to main loop");
262 _dbus_watch_unref (watch);
267 if (!_dbus_register_shutdown_func (_shutdown_inotify, NULL))
269 _dbus_warn ("Unable to register shutdown func");
270 _dbus_watch_unref (watch);
283 bus_set_watched_dirs (BusContext *context, DBusList **directories)
285 if (!_init_inotify (context))
288 _set_watched_dirs_internal (directories);