2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2006
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 3 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/>.
21 notify implementation using inotify
25 #include "system/filesys.h"
26 #include "ntvfs/sysdep/sys_notify.h"
27 #include "lib/events/events.h"
28 #include "lib/util/dlinklist.h"
29 #include "libcli/raw/smb.h"
30 #include "param/param.h"
32 #include <linux/inotify.h>
33 #include <asm/unistd.h>
35 #ifndef HAVE_INOTIFY_INIT
37 glibc doesn't define these functions yet (as of March 2006)
39 static int inotify_init(void)
41 return syscall(__NR_inotify_init);
44 static int inotify_add_watch(int fd, const char *path, __u32 mask)
46 return syscall(__NR_inotify_add_watch, fd, path, mask);
49 static int inotify_rm_watch(int fd, int wd)
51 return syscall(__NR_inotify_rm_watch, fd, wd);
56 /* older glibc headers don't have these defines either */
58 #define IN_ONLYDIR 0x01000000
61 #define IN_MASK_ADD 0x20000000
64 struct inotify_private {
65 struct sys_notify_context *ctx;
67 struct inotify_watch_context *watches;
70 struct inotify_watch_context {
71 struct inotify_watch_context *next, *prev;
72 struct inotify_private *in;
74 sys_notify_callback_t callback;
76 uint32_t mask; /* the inotify mask */
77 uint32_t filter; /* the windows completion filter */
83 see if a particular event from inotify really does match a requested
86 static bool filter_match(struct inotify_watch_context *w,
87 struct inotify_event *e)
89 if ((e->mask & w->mask) == 0) {
90 /* this happens because inotify_add_watch() coalesces watches on the same
91 path, oring their masks together */
95 /* SMB separates the filters for files and directories */
96 if (e->mask & IN_ISDIR) {
97 if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
101 if ((e->mask & IN_ATTRIB) &&
102 (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
103 FILE_NOTIFY_CHANGE_LAST_WRITE|
104 FILE_NOTIFY_CHANGE_LAST_ACCESS|
105 FILE_NOTIFY_CHANGE_EA|
106 FILE_NOTIFY_CHANGE_SECURITY))) {
109 if ((e->mask & IN_MODIFY) &&
110 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
113 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
124 dispatch one inotify event
126 the cookies are used to correctly handle renames
128 static void inotify_dispatch(struct inotify_private *in,
129 struct inotify_event *e,
130 uint32_t prev_cookie,
131 struct inotify_event *e2)
133 struct inotify_watch_context *w, *next;
134 struct notify_event ne;
136 /* ignore extraneous events, such as unmount and IN_IGNORED events */
137 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
138 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
142 /* map the inotify mask to a action. This gets complicated for
144 if (e->mask & IN_CREATE) {
145 ne.action = NOTIFY_ACTION_ADDED;
146 } else if (e->mask & IN_DELETE) {
147 ne.action = NOTIFY_ACTION_REMOVED;
148 } else if (e->mask & IN_MOVED_FROM) {
149 if (e2 != NULL && e2->cookie == e->cookie) {
150 ne.action = NOTIFY_ACTION_OLD_NAME;
152 ne.action = NOTIFY_ACTION_REMOVED;
154 } else if (e->mask & IN_MOVED_TO) {
155 if (e->cookie == prev_cookie) {
156 ne.action = NOTIFY_ACTION_NEW_NAME;
158 ne.action = NOTIFY_ACTION_ADDED;
161 ne.action = NOTIFY_ACTION_MODIFIED;
165 /* find any watches that have this watch descriptor */
166 for (w=in->watches;w;w=next) {
168 if (w->wd == e->wd && filter_match(w, e)) {
169 w->callback(in->ctx, w->private_data, &ne);
173 /* SMB expects a file rename to generate three events, two for
174 the rename and the other for a modify of the
175 destination. Strange! */
176 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
177 (e->mask & IN_ISDIR) != 0) {
181 ne.action = NOTIFY_ACTION_MODIFIED;
184 for (w=in->watches;w;w=next) {
186 if (w->wd == e->wd && filter_match(w, e) &&
187 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
188 w->callback(in->ctx, w->private_data, &ne);
194 called when the kernel has some events for us
196 static void inotify_handler(struct event_context *ev, struct fd_event *fde,
197 uint16_t flags, void *private_data)
199 struct inotify_private *in = talloc_get_type(private_data,
200 struct inotify_private);
202 struct inotify_event *e0, *e;
203 uint32_t prev_cookie=0;
206 we must use FIONREAD as we cannot predict the length of the
207 filenames, and thus can't know how much to allocate
210 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
212 DEBUG(0,("No data on inotify fd?!\n"));
216 e0 = e = talloc_size(in, bufsize);
217 if (e == NULL) return;
219 if (read(in->fd, e0, bufsize) != bufsize) {
220 DEBUG(0,("Failed to read all inotify data\n"));
225 /* we can get more than one event in the buffer */
226 while (bufsize >= sizeof(*e)) {
227 struct inotify_event *e2 = NULL;
228 bufsize -= e->len + sizeof(*e);
229 if (bufsize >= sizeof(*e)) {
230 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
232 inotify_dispatch(in, e, prev_cookie, e2);
233 prev_cookie = e->cookie;
241 setup the inotify handle - called the first time a watch is added on
244 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
246 struct inotify_private *in;
247 in = talloc(ctx, struct inotify_private);
248 NT_STATUS_HAVE_NO_MEMORY(in);
249 in->fd = inotify_init();
251 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
253 return map_nt_error_from_unix(errno);
258 ctx->private_data = in;
260 /* add a event waiting for the inotify fd to be readable */
261 event_add_fd(ctx->ev, in, in->fd, EVENT_FD_READ|EVENT_FD_AUTOCLOSE, inotify_handler, in);
268 map from a change notify mask to a inotify mask. Remove any bits
271 static const struct {
272 uint32_t notify_mask;
273 uint32_t inotify_mask;
274 } inotify_mapping[] = {
275 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
276 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
277 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
278 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
279 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
280 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
281 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
284 static uint32_t inotify_map(struct notify_entry *e)
288 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
289 if (inotify_mapping[i].notify_mask & e->filter) {
290 out |= inotify_mapping[i].inotify_mask;
291 e->filter &= ~inotify_mapping[i].notify_mask;
300 static int watch_destructor(struct inotify_watch_context *w)
302 struct inotify_private *in = w->in;
304 DLIST_REMOVE(w->in->watches, w);
306 /* only rm the watch if its the last one with this wd */
307 for (w=in->watches;w;w=w->next) {
308 if (w->wd == wd) break;
311 inotify_rm_watch(in->fd, wd);
318 add a watch. The watch is removed when the caller calls
319 talloc_free() on *handle
321 static NTSTATUS inotify_watch(struct sys_notify_context *ctx,
322 struct notify_entry *e,
323 sys_notify_callback_t callback,
327 struct inotify_private *in;
330 struct inotify_watch_context *w;
331 uint32_t filter = e->filter;
332 void **handle = (void **)handle_p;
334 /* maybe setup the inotify fd */
335 if (ctx->private_data == NULL) {
337 if (!lp_parm_bool(global_loadparm, NULL, "notify", "inotify", true)) {
338 return NT_STATUS_INVALID_SYSTEM_SERVICE;
341 status = inotify_setup(ctx);
342 NT_STATUS_NOT_OK_RETURN(status);
345 in = talloc_get_type(ctx->private_data, struct inotify_private);
347 mask = inotify_map(e);
349 /* this filter can't be handled by inotify */
350 return NT_STATUS_INVALID_PARAMETER;
353 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
354 watch descriptor for muliple watches on the same path */
355 mask |= (IN_MASK_ADD | IN_ONLYDIR);
357 /* get a new watch descriptor for this path */
358 wd = inotify_add_watch(in->fd, e->path, mask);
361 return map_nt_error_from_unix(errno);
364 w = talloc(in, struct inotify_watch_context);
366 inotify_rm_watch(in->fd, wd);
368 return NT_STATUS_NO_MEMORY;
373 w->callback = callback;
374 w->private_data = private_data;
377 w->path = talloc_strdup(w, e->path);
378 if (w->path == NULL) {
379 inotify_rm_watch(in->fd, wd);
381 return NT_STATUS_NO_MEMORY;
386 DLIST_ADD(in->watches, w);
388 /* the caller frees the handle to stop watching */
389 talloc_set_destructor(w, watch_destructor);
395 static struct sys_notify_backend inotify = {
397 .notify_watch = inotify_watch
401 initialialise the inotify module
403 NTSTATUS sys_notify_inotify_init(void)
405 /* register ourselves as a system inotify module */
406 return sys_notify_register(&inotify);