source: trunk/samba-3.0.25pre1/source/modules/vfs_notify_fam.c@ 1

Last change on this file since 1 was 1, checked in by Paul Smedley, 19 years ago

Initial code import
File size: 7.5 KB
Line 
1/*
2 * FAM file notification support.
3 *
4 * Copyright (c) James Peach 2005
5 * Copyright (c) Volker Lendecke 2007
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include "includes.h"
23
24#include <fam.h>
25
26#if !defined(HAVE_FAM_H_FAMCODES_TYPEDEF)
27/* Gamin provides this typedef which means we can't use 'enum FAMCodes' as per
28 * every other FAM implementation. Phooey.
29 */
30typedef enum FAMCodes FAMCodes;
31#endif
32
33/* NOTE: There are multiple versions of FAM floating around the net, each with
34 * slight differences from the original SGI FAM implementation. In this file,
35 * we rely only on the SGI features and do not assume any extensions. For
36 * example, we do not look at FAMErrno, because it is not set by the original
37 * implementation.
38 *
39 * Random FAM links:
40 * http://oss.sgi.com/projects/fam/
41 * http://savannah.nongnu.org/projects/fam/
42 * http://sourceforge.net/projects/bsdfam/
43 */
44
45/* ------------------------------------------------------------------------- */
46
47struct fam_watch_context {
48 struct fam_watch_context *prev, *next;
49 FAMConnection *fam_connection;
50 struct FAMRequest fr;
51 struct sys_notify_context *sys_ctx;
52 void (*callback)(struct sys_notify_context *ctx,
53 void *private_data,
54 struct notify_event *ev);
55 void *private_data;
56 uint32_t mask; /* the inotify mask */
57 uint32_t filter; /* the windows completion filter */
58 const char *path;
59};
60
61
62/*
63 * We want one FAM connection per smbd, not one per tcon.
64 */
65static FAMConnection fam_connection;
66static BOOL fam_connection_initialized = False;
67
68static struct fam_watch_context *fam_notify_list;
69static void fam_handler(struct event_context *event_ctx,
70 struct fd_event *fd_event,
71 uint16 flags,
72 void *private_data);
73
74static NTSTATUS fam_open_connection(FAMConnection *fam_conn,
75 struct event_context *event_ctx)
76{
77 int res;
78 char *name;
79
80 ZERO_STRUCTP(fam_conn);
81 FAMCONNECTION_GETFD(fam_conn) = -1;
82
83 if (asprintf(&name, "smbd (%lu)", (unsigned long)sys_getpid()) == -1) {
84 DEBUG(0, ("No memory\n"));
85 return NT_STATUS_NO_MEMORY;
86 }
87
88 res = FAMOpen2(fam_conn, name);
89 SAFE_FREE(name);
90
91 if (res < 0) {
92 DEBUG(10, ("FAM file change notifications not available\n"));
93 /*
94 * No idea how to get NT_STATUS from a FAM result
95 */
96 FAMCONNECTION_GETFD(fam_conn) = -1;
97 return NT_STATUS_UNEXPECTED_IO_ERROR;
98 }
99
100 if (event_add_fd(event_ctx, event_ctx,
101 FAMCONNECTION_GETFD(fam_conn),
102 EVENT_FD_READ, fam_handler,
103 (void *)fam_conn) == NULL) {
104 DEBUG(0, ("event_add_fd failed\n"));
105 FAMClose(fam_conn);
106 FAMCONNECTION_GETFD(fam_conn) = -1;
107 return NT_STATUS_NO_MEMORY;
108 }
109
110 return NT_STATUS_OK;
111}
112
113static void fam_reopen(FAMConnection *fam_conn,
114 struct event_context *event_ctx,
115 struct fam_watch_context *notify_list)
116{
117 struct fam_watch_context *ctx;
118
119 DEBUG(5, ("Re-opening FAM connection\n"));
120
121 FAMClose(fam_conn);
122
123 if (!NT_STATUS_IS_OK(fam_open_connection(fam_conn, event_ctx))) {
124 DEBUG(5, ("Re-opening fam connection failed\n"));
125 return;
126 }
127
128 for (ctx = notify_list; ctx; ctx = ctx->next) {
129 FAMMonitorDirectory(fam_conn, ctx->path, &ctx->fr, NULL);
130 }
131}
132
133static void fam_handler(struct event_context *event_ctx,
134 struct fd_event *fd_event,
135 uint16 flags,
136 void *private_data)
137{
138 FAMConnection *fam_conn = (FAMConnection *)private_data;
139 FAMEvent fam_event;
140 struct fam_watch_context *ctx;
141 struct notify_event ne;
142
143 if (FAMPending(fam_conn) == 0) {
144 DEBUG(10, ("fam_handler called but nothing pending\n"));
145 return;
146 }
147
148 if (FAMNextEvent(fam_conn, &fam_event) != 1) {
149 DEBUG(5, ("FAMNextEvent returned an error\n"));
150 TALLOC_FREE(fd_event);
151 fam_reopen(fam_conn, event_ctx, fam_notify_list);
152 return;
153 }
154
155 DEBUG(10, ("Got FAMCode %d for %s\n", fam_event.code,
156 fam_event.filename));
157
158 switch (fam_event.code) {
159 case FAMCreated:
160 ne.action = NOTIFY_ACTION_ADDED;
161 break;
162 case FAMDeleted:
163 ne.action = NOTIFY_ACTION_REMOVED;
164 break;
165 default:
166 DEBUG(10, ("Ignoring code FAMCode %d for file %s\n",
167 (int)fam_event.code, fam_event.filename));
168 return;
169 }
170
171 for (ctx = fam_notify_list; ctx; ctx = ctx->next) {
172 if (memcmp(&fam_event.fr, &ctx->fr, sizeof(FAMRequest)) == 0) {
173 break;
174 }
175 }
176
177 if (ctx == NULL) {
178 DEBUG(5, ("Discarding event for file %s\n",
179 fam_event.filename));
180 return;
181 }
182
183 if ((ne.path = strrchr_m(fam_event.filename, '\\')) == NULL) {
184 ne.path = fam_event.filename;
185 }
186
187 ctx->callback(ctx->sys_ctx, ctx->private_data, &ne);
188}
189
190static int fam_watch_context_destructor(struct fam_watch_context *ctx)
191{
192 if (FAMCONNECTION_GETFD(ctx->fam_connection) != -1) {
193 FAMCancelMonitor(&fam_connection, &ctx->fr);
194 }
195 DLIST_REMOVE(fam_notify_list, ctx);
196 return 0;
197}
198
199/*
200 add a watch. The watch is removed when the caller calls
201 talloc_free() on *handle
202*/
203static NTSTATUS fam_watch(vfs_handle_struct *vfs_handle,
204 struct sys_notify_context *ctx,
205 struct notify_entry *e,
206 void (*callback)(struct sys_notify_context *ctx,
207 void *private_data,
208 struct notify_event *ev),
209 void *private_data,
210 void *handle_p)
211{
212 const uint32 fam_mask = (FILE_NOTIFY_CHANGE_FILE_NAME|
213 FILE_NOTIFY_CHANGE_DIR_NAME);
214 struct fam_watch_context *watch;
215 void **handle = (void **)handle_p;
216
217 if ((e->filter & fam_mask) == 0) {
218 DEBUG(10, ("filter = %u, ignoring in FAM\n", e->filter));
219 return NT_STATUS_OK;
220 }
221
222 if (!fam_connection_initialized) {
223 if (!NT_STATUS_IS_OK(fam_open_connection(&fam_connection,
224 ctx->ev))) {
225 /*
226 * Just let smbd do all the work itself
227 */
228 return NT_STATUS_OK;
229 }
230 fam_connection_initialized = True;
231 }
232
233 if (!(watch = TALLOC_P(ctx, struct fam_watch_context))) {
234 return NT_STATUS_NO_MEMORY;
235 }
236
237 watch->fam_connection = &fam_connection;
238
239 watch->callback = callback;
240 watch->private_data = private_data;
241 watch->sys_ctx = ctx;
242
243 if (!(watch->path = talloc_strdup(watch, e->path))) {
244 DEBUG(0, ("talloc_asprintf failed\n"));
245 TALLOC_FREE(watch);
246 return NT_STATUS_NO_MEMORY;
247 }
248
249 /*
250 * The FAM module in this early state will only take care of
251 * FAMCreated and FAMDeleted events, Leave the rest to
252 * notify_internal.c
253 */
254
255 watch->filter = fam_mask;
256 e->filter &= ~fam_mask;
257
258 DLIST_ADD(fam_notify_list, watch);
259 talloc_set_destructor(watch, fam_watch_context_destructor);
260
261 /*
262 * Only directories monitored so far
263 */
264
265 if (FAMCONNECTION_GETFD(watch->fam_connection) != -1) {
266 FAMMonitorDirectory(watch->fam_connection, watch->path,
267 &watch->fr, NULL);
268 }
269 else {
270 /*
271 * If the re-open is successful, this will establish the
272 * FAMMonitor from the list
273 */
274 fam_reopen(watch->fam_connection, ctx->ev, fam_notify_list);
275 }
276
277 *handle = (void *)watch;
278
279 return NT_STATUS_OK;
280}
281
282/* VFS operations structure */
283
284static vfs_op_tuple notify_fam_op_tuples[] = {
285
286 {SMB_VFS_OP(fam_watch),
287 SMB_VFS_OP_NOTIFY_WATCH,
288 SMB_VFS_LAYER_OPAQUE},
289
290 {SMB_VFS_OP(NULL),
291 SMB_VFS_OP_NOOP,
292 SMB_VFS_LAYER_NOOP}
293
294};
295
296
297NTSTATUS vfs_notify_fam_init(void);
298NTSTATUS vfs_notify_fam_init(void)
299{
300 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "notify_fam",
301 notify_fam_op_tuples);
302}
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