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 #if HAVE_SYS_INOTIFY_H
33 #include <sys/inotify.h>
35 /* for older glibc varients - we can remove this eventually */
36 #include <linux/inotify.h>
37 #include <asm/unistd.h>
39 #ifndef HAVE_INOTIFY_INIT
41 glibc doesn't define these functions yet (as of March 2006)
43 static int inotify_init(void)
45 return syscall(__NR_inotify_init);
48 static int inotify_add_watch(int fd, const char *path, __u32 mask)
50 return syscall(__NR_inotify_add_watch, fd, path, mask);
53 static int inotify_rm_watch(int fd, int wd)
55 return syscall(__NR_inotify_rm_watch, fd, wd);
61 /* older glibc headers don't have these defines either */
63 #define IN_ONLYDIR 0x01000000
66 #define IN_MASK_ADD 0x20000000
69 struct inotify_private {
70 struct sys_notify_context *ctx;
72 struct inotify_watch_context *watches;
75 struct inotify_watch_context {
76 struct inotify_watch_context *next, *prev;
77 struct inotify_private *in;
79 sys_notify_callback_t callback;
81 uint32_t mask; /* the inotify mask */
82 uint32_t filter; /* the windows completion filter */
88 see if a particular event from inotify really does match a requested
91 static bool filter_match(struct inotify_watch_context *w,
92 struct inotify_event *e)
94 if ((e->mask & w->mask) == 0) {
95 /* this happens because inotify_add_watch() coalesces watches on the same
96 path, oring their masks together */
100 /* SMB separates the filters for files and directories */
101 if (e->mask & IN_ISDIR) {
102 if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
106 if ((e->mask & IN_ATTRIB) &&
107 (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
108 FILE_NOTIFY_CHANGE_LAST_WRITE|
109 FILE_NOTIFY_CHANGE_LAST_ACCESS|
110 FILE_NOTIFY_CHANGE_EA|
111 FILE_NOTIFY_CHANGE_SECURITY))) {
114 if ((e->mask & IN_MODIFY) &&
115 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
118 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
129 dispatch one inotify event
131 the cookies are used to correctly handle renames
133 static void inotify_dispatch(struct inotify_private *in,
134 struct inotify_event *e,
135 uint32_t prev_cookie,
136 struct inotify_event *e2)
138 struct inotify_watch_context *w, *next;
139 struct notify_event ne;
141 /* ignore extraneous events, such as unmount and IN_IGNORED events */
142 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
143 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
147 /* map the inotify mask to a action. This gets complicated for
149 if (e->mask & IN_CREATE) {
150 ne.action = NOTIFY_ACTION_ADDED;
151 } else if (e->mask & IN_DELETE) {
152 ne.action = NOTIFY_ACTION_REMOVED;
153 } else if (e->mask & IN_MOVED_FROM) {
154 if (e2 != NULL && e2->cookie == e->cookie) {
155 ne.action = NOTIFY_ACTION_OLD_NAME;
157 ne.action = NOTIFY_ACTION_REMOVED;
159 } else if (e->mask & IN_MOVED_TO) {
160 if (e->cookie == prev_cookie) {
161 ne.action = NOTIFY_ACTION_NEW_NAME;
163 ne.action = NOTIFY_ACTION_ADDED;
166 ne.action = NOTIFY_ACTION_MODIFIED;
170 /* find any watches that have this watch descriptor */
171 for (w=in->watches;w;w=next) {
173 if (w->wd == e->wd && filter_match(w, e)) {
174 w->callback(in->ctx, w->private_data, &ne);
178 /* SMB expects a file rename to generate three events, two for
179 the rename and the other for a modify of the
180 destination. Strange! */
181 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
182 (e->mask & IN_ISDIR) != 0) {
186 ne.action = NOTIFY_ACTION_MODIFIED;
189 for (w=in->watches;w;w=next) {
191 if (w->wd == e->wd && filter_match(w, e) &&
192 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
193 w->callback(in->ctx, w->private_data, &ne);
199 called when the kernel has some events for us
201 static void inotify_handler(struct event_context *ev, struct fd_event *fde,
202 uint16_t flags, void *private_data)
204 struct inotify_private *in = talloc_get_type(private_data,
205 struct inotify_private);
207 struct inotify_event *e0, *e;
208 uint32_t prev_cookie=0;
211 we must use FIONREAD as we cannot predict the length of the
212 filenames, and thus can't know how much to allocate
215 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
217 DEBUG(0,("No data on inotify fd?!\n"));
221 e0 = e = talloc_size(in, bufsize);
222 if (e == NULL) return;
224 if (read(in->fd, e0, bufsize) != bufsize) {
225 DEBUG(0,("Failed to read all inotify data\n"));
230 /* we can get more than one event in the buffer */
231 while (bufsize >= sizeof(*e)) {
232 struct inotify_event *e2 = NULL;
233 bufsize -= e->len + sizeof(*e);
234 if (bufsize >= sizeof(*e)) {
235 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
237 inotify_dispatch(in, e, prev_cookie, e2);
238 prev_cookie = e->cookie;
246 setup the inotify handle - called the first time a watch is added on
249 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
251 struct inotify_private *in;
252 in = talloc(ctx, struct inotify_private);
253 NT_STATUS_HAVE_NO_MEMORY(in);
254 in->fd = inotify_init();
256 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
258 return map_nt_error_from_unix(errno);
263 ctx->private_data = in;
265 /* add a event waiting for the inotify fd to be readable */
266 event_add_fd(ctx->ev, in, in->fd, EVENT_FD_READ|EVENT_FD_AUTOCLOSE, inotify_handler, in);
273 map from a change notify mask to a inotify mask. Remove any bits
276 static const struct {
277 uint32_t notify_mask;
278 uint32_t inotify_mask;
279 } inotify_mapping[] = {
280 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
281 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
282 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
283 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
284 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
285 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
286 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
289 static uint32_t inotify_map(struct notify_entry *e)
293 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
294 if (inotify_mapping[i].notify_mask & e->filter) {
295 out |= inotify_mapping[i].inotify_mask;
296 e->filter &= ~inotify_mapping[i].notify_mask;
305 static int watch_destructor(struct inotify_watch_context *w)
307 struct inotify_private *in = w->in;
309 DLIST_REMOVE(w->in->watches, w);
311 /* only rm the watch if its the last one with this wd */
312 for (w=in->watches;w;w=w->next) {
313 if (w->wd == wd) break;
316 inotify_rm_watch(in->fd, wd);
323 add a watch. The watch is removed when the caller calls
324 talloc_free() on *handle
326 static NTSTATUS inotify_watch(struct sys_notify_context *ctx,
327 struct notify_entry *e,
328 sys_notify_callback_t callback,
332 struct inotify_private *in;
335 struct inotify_watch_context *w;
336 uint32_t filter = e->filter;
337 void **handle = (void **)handle_p;
339 /* maybe setup the inotify fd */
340 if (ctx->private_data == NULL) {
342 status = inotify_setup(ctx);
343 NT_STATUS_NOT_OK_RETURN(status);
346 in = talloc_get_type(ctx->private_data, struct inotify_private);
348 mask = inotify_map(e);
350 /* this filter can't be handled by inotify */
351 return NT_STATUS_INVALID_PARAMETER;
354 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
355 watch descriptor for muliple watches on the same path */
356 mask |= (IN_MASK_ADD | IN_ONLYDIR);
358 /* get a new watch descriptor for this path */
359 wd = inotify_add_watch(in->fd, e->path, mask);
362 return map_nt_error_from_unix(errno);
365 w = talloc(in, struct inotify_watch_context);
367 inotify_rm_watch(in->fd, wd);
369 return NT_STATUS_NO_MEMORY;
374 w->callback = callback;
375 w->private_data = private_data;
378 w->path = talloc_strdup(w, e->path);
379 if (w->path == NULL) {
380 inotify_rm_watch(in->fd, wd);
382 return NT_STATUS_NO_MEMORY;
387 DLIST_ADD(in->watches, w);
389 /* the caller frees the handle to stop watching */
390 talloc_set_destructor(w, watch_destructor);
396 static struct sys_notify_backend inotify = {
398 .notify_watch = inotify_watch
402 initialialise the inotify module
404 NTSTATUS sys_notify_inotify_init(void)
406 /* register ourselves as a system inotify module */
407 return sys_notify_register(&inotify);