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 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, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 notify implementation using inotify
26 #include "system/filesys.h"
27 #include "ntvfs/sysdep/sys_notify.h"
28 #include "lib/events/events.h"
30 #include "dlinklist.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 watch_context *watches;
70 struct watch_context {
71 struct 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 destroy the inotify private context
85 static int inotify_destructor(struct inotify_private *in)
93 see if a particular event from inotify really does match a requested
96 static BOOL filter_match(struct watch_context *w, struct inotify_event *e)
98 if ((e->mask & w->mask) == 0) {
99 /* this happens because inotify_add_watch() coalesces watches on the same
100 path, oring their masks together */
104 /* SMB separates the filters for files and directories */
105 if (e->mask & IN_ISDIR) {
106 if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
110 if ((e->mask & IN_ATTRIB) &&
111 (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
112 FILE_NOTIFY_CHANGE_LAST_WRITE|
113 FILE_NOTIFY_CHANGE_LAST_ACCESS|
114 FILE_NOTIFY_CHANGE_EA|
115 FILE_NOTIFY_CHANGE_SECURITY))) {
118 if ((e->mask & IN_MODIFY) &&
119 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
122 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
133 dispatch one inotify event
135 the cookies are used to correctly handle renames
137 static void inotify_dispatch(struct inotify_private *in,
138 struct inotify_event *e,
139 uint32_t prev_cookie,
140 struct inotify_event *e2)
142 struct watch_context *w, *next;
143 struct notify_event ne;
145 /* ignore extraneous events, such as unmount and IN_IGNORED events */
146 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
147 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
151 /* map the inotify mask to a action. This gets complicated for
153 if (e->mask & IN_CREATE) {
154 ne.action = NOTIFY_ACTION_ADDED;
155 } else if (e->mask & IN_DELETE) {
156 ne.action = NOTIFY_ACTION_REMOVED;
157 } else if (e->mask & IN_MOVED_FROM) {
158 if (e2 != NULL && e2->cookie == e->cookie) {
159 ne.action = NOTIFY_ACTION_OLD_NAME;
161 ne.action = NOTIFY_ACTION_REMOVED;
163 } else if (e->mask & IN_MOVED_TO) {
164 if (e->cookie == prev_cookie) {
165 ne.action = NOTIFY_ACTION_NEW_NAME;
167 ne.action = NOTIFY_ACTION_ADDED;
170 ne.action = NOTIFY_ACTION_MODIFIED;
174 /* find any watches that have this watch descriptor */
175 for (w=in->watches;w;w=next) {
177 if (w->wd == e->wd && filter_match(w, e)) {
178 w->callback(in->ctx, w->private, &ne);
182 /* SMB expects a file rename to generate three events, two for
183 the rename and the other for a modify of the
184 destination. Strange! */
185 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
186 (e->mask & IN_ISDIR) != 0) {
190 ne.action = NOTIFY_ACTION_MODIFIED;
193 for (w=in->watches;w;w=next) {
195 if (w->wd == e->wd && filter_match(w, e) &&
196 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
197 w->callback(in->ctx, w->private, &ne);
203 called when the kernel has some events for us
205 static void inotify_handler(struct event_context *ev, struct fd_event *fde,
206 uint16_t flags, void *private)
208 struct inotify_private *in = talloc_get_type(private, struct inotify_private);
210 struct inotify_event *e0, *e;
211 uint32_t prev_cookie=0;
214 we must use FIONREAD as we cannot predict the length of the
215 filenames, and thus can't know how much to allocate
218 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
220 DEBUG(0,("No data on inotify fd?!\n"));
224 e0 = e = talloc_size(in, bufsize);
225 if (e == NULL) return;
227 if (read(in->fd, e0, bufsize) != bufsize) {
228 DEBUG(0,("Failed to read all inotify data\n"));
233 /* we can get more than one event in the buffer */
234 while (bufsize >= sizeof(*e)) {
235 struct inotify_event *e2 = NULL;
236 bufsize -= e->len + sizeof(*e);
237 if (bufsize >= sizeof(*e)) {
238 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
240 inotify_dispatch(in, e, prev_cookie, e2);
241 prev_cookie = e->cookie;
249 setup the inotify handle - called the first time a watch is added on
252 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
254 struct inotify_private *in;
256 in = talloc(ctx, struct inotify_private);
257 NT_STATUS_HAVE_NO_MEMORY(in);
258 in->fd = inotify_init();
260 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
262 return map_nt_error_from_unix(errno);
268 talloc_set_destructor(in, inotify_destructor);
270 /* add a event waiting for the inotify fd to be readable */
271 event_add_fd(ctx->ev, in, in->fd, EVENT_FD_READ, inotify_handler, in);
278 map from a change notify mask to a inotify mask. Remove any bits
281 static const struct {
282 uint32_t notify_mask;
283 uint32_t inotify_mask;
284 } inotify_mapping[] = {
285 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
286 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
287 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
288 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
289 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
290 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
291 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
294 static uint32_t inotify_map(struct notify_entry *e)
298 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
299 if (inotify_mapping[i].notify_mask & e->filter) {
300 out |= inotify_mapping[i].inotify_mask;
301 e->filter &= ~inotify_mapping[i].notify_mask;
310 static int watch_destructor(struct watch_context *w)
312 struct inotify_private *in = w->in;
314 DLIST_REMOVE(w->in->watches, w);
316 /* only rm the watch if its the last one with this wd */
317 for (w=in->watches;w;w=w->next) {
318 if (w->wd == wd) break;
321 inotify_rm_watch(in->fd, wd);
328 add a watch. The watch is removed when the caller calls
329 talloc_free() on *handle
331 static NTSTATUS inotify_watch(struct sys_notify_context *ctx, struct notify_entry *e,
332 sys_notify_callback_t callback, void *private,
335 struct inotify_private *in;
338 struct watch_context *w;
339 uint32_t filter = e->filter;
341 /* maybe setup the inotify fd */
342 if (ctx->private == NULL) {
344 status = inotify_setup(ctx);
345 NT_STATUS_NOT_OK_RETURN(status);
348 in = talloc_get_type(ctx->private, struct inotify_private);
350 mask = inotify_map(e);
352 /* this filter can't be handled by inotify */
353 return NT_STATUS_INVALID_PARAMETER;
356 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
357 watch descriptor for muliple watches on the same path */
358 mask |= (IN_MASK_ADD | IN_ONLYDIR);
360 /* get a new watch descriptor for this path */
361 wd = inotify_add_watch(in->fd, e->path, mask);
364 return map_nt_error_from_unix(errno);
367 w = talloc(in, struct watch_context);
369 inotify_rm_watch(in->fd, wd);
371 return NT_STATUS_NO_MEMORY;
376 w->callback = callback;
377 w->private = private;
380 w->path = talloc_strdup(w, e->path);
381 if (w->path == NULL) {
382 inotify_rm_watch(in->fd, wd);
384 return NT_STATUS_NO_MEMORY;
389 DLIST_ADD(in->watches, w);
391 /* the caller frees the handle to stop watching */
392 talloc_set_destructor(w, watch_destructor);
398 static struct sys_notify_backend inotify = {
400 .notify_watch = inotify_watch
404 initialialise the inotify module
406 NTSTATUS sys_notify_inotify_init(void)
408 /* register ourselves as a system inotify module */
409 return sys_notify_register(&inotify);