source: vendor/3.6.23/source3/smbd/oplock_irix.c

Last change on this file was 740, checked in by Silvan Scherrer, 13 years ago

Samba Server: update vendor to 3.6.0
File size: 9.4 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 IRIX kernel oplock processing
4 Copyright (C) Andrew Tridgell 1992-1998
5
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.
10
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.
15
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/>.
18*/
19
20#define DBGC_CLASS DBGC_LOCKING
21#include "includes.h"
22#include "system/filesys.h"
23#include "smbd/smbd.h"
24#include "smbd/globals.h"
25
26#if HAVE_KERNEL_OPLOCKS_IRIX
27
28struct irix_oplocks_context {
29 struct kernel_oplocks *ctx;
30 int write_fd;
31 int read_fd;
32 struct fd_event *read_fde;
33 bool pending;
34};
35
36/****************************************************************************
37 Test to see if IRIX kernel oplocks work.
38****************************************************************************/
39
40static bool irix_oplocks_available(void)
41{
42 int fd;
43 int pfd[2];
44 TALLOC_CTX *ctx = talloc_stackframe();
45 char *tmpname = NULL;
46
47 set_effective_capability(KERNEL_OPLOCK_CAPABILITY);
48
49 tmpname = talloc_asprintf(ctx,
50 "%s/koplock.%d",
51 lp_lockdir(),
52 (int)sys_getpid());
53 if (!tmpname) {
54 TALLOC_FREE(ctx);
55 return False;
56 }
57
58 if(pipe(pfd) != 0) {
59 DEBUG(0,("check_kernel_oplocks: Unable to create pipe. Error "
60 "was %s\n",
61 strerror(errno) ));
62 TALLOC_FREE(ctx);
63 return False;
64 }
65
66 if((fd = sys_open(tmpname, O_RDWR|O_CREAT|O_EXCL|O_TRUNC, 0600)) < 0) {
67 DEBUG(0,("check_kernel_oplocks: Unable to open temp test file "
68 "%s. Error was %s\n",
69 tmpname, strerror(errno) ));
70 unlink( tmpname );
71 close(pfd[0]);
72 close(pfd[1]);
73 TALLOC_FREE(ctx);
74 return False;
75 }
76
77 unlink(tmpname);
78
79 TALLOC_FREE(ctx);
80
81 if(sys_fcntl_long(fd, F_OPLKREG, pfd[1]) == -1) {
82 DEBUG(0,("check_kernel_oplocks: Kernel oplocks are not "
83 "available on this machine. Disabling kernel oplock "
84 "support.\n" ));
85 close(pfd[0]);
86 close(pfd[1]);
87 close(fd);
88 return False;
89 }
90
91 if(sys_fcntl_long(fd, F_OPLKACK, OP_REVOKE) < 0 ) {
92 DEBUG(0,("check_kernel_oplocks: Error when removing kernel "
93 "oplock. Error was %s. Disabling kernel oplock "
94 "support.\n", strerror(errno) ));
95 close(pfd[0]);
96 close(pfd[1]);
97 close(fd);
98 return False;
99 }
100
101 close(pfd[0]);
102 close(pfd[1]);
103 close(fd);
104
105 return True;
106}
107
108/*
109 * This is bad because the file_id should always be created through the vfs
110 * layer! Unfortunately, a conn struct isn't available here.
111 */
112static struct file_id file_id_create_dev(SMB_DEV_T dev, SMB_INO_T inode)
113{
114 struct file_id key;
115
116 /* the ZERO_STRUCT ensures padding doesn't break using the key as a
117 * blob */
118 ZERO_STRUCT(key);
119
120 key.devid = dev;
121 key.inode = inode;
122
123 return key;
124}
125
126/****************************************************************************
127 * Deal with the IRIX kernel <--> smbd
128 * oplock break protocol.
129****************************************************************************/
130
131static files_struct *irix_oplock_receive_message(struct kernel_oplocks *_ctx)
132{
133 struct irix_oplocks_context *ctx = talloc_get_type(_ctx->private_data,
134 struct irix_oplocks_context);
135 oplock_stat_t os;
136 char dummy;
137 struct file_id fileid;
138 files_struct *fsp;
139
140 /*
141 * TODO: is it correct to assume we only get one
142 * oplock break, for each byte we read from the pipe?
143 */
144 ctx->pending = false;
145
146 /*
147 * Read one byte of zero to clear the
148 * kernel break notify message.
149 */
150
151 if(read(ctx->read_fd, &dummy, 1) != 1) {
152 DEBUG(0,("irix_oplock_receive_message: read of kernel "
153 "notification failed. Error was %s.\n",
154 strerror(errno) ));
155 return NULL;
156 }
157
158 /*
159 * Do a query to get the
160 * device and inode of the file that has the break
161 * request outstanding.
162 */
163
164 if(sys_fcntl_ptr(ctx->read_fd, F_OPLKSTAT, &os) < 0) {
165 DEBUG(0,("irix_oplock_receive_message: fcntl of kernel "
166 "notification failed. Error was %s.\n",
167 strerror(errno) ));
168 if(errno == EAGAIN) {
169 /*
170 * Duplicate kernel break message - ignore.
171 */
172 return NULL;
173 }
174 return NULL;
175 }
176
177 /*
178 * We only have device and inode info here - we have to guess that this
179 * is the first fsp open with this dev,ino pair.
180 *
181 * NOTE: this doesn't work if any VFS modules overloads
182 * the file_id_create() hook!
183 */
184
185 fileid = file_id_create_dev((SMB_DEV_T)os.os_dev,
186 (SMB_INO_T)os.os_ino);
187 if ((fsp = file_find_di_first(smbd_server_conn, fileid)) == NULL) {
188 DEBUG(0,("irix_oplock_receive_message: unable to find open "
189 "file with dev = %x, inode = %.0f\n",
190 (unsigned int)os.os_dev, (double)os.os_ino ));
191 return NULL;
192 }
193
194 DEBUG(5,("irix_oplock_receive_message: kernel oplock break request "
195 "received for file_id %s gen_id = %ul",
196 file_id_string_tos(&fsp->file_id),
197 fsp->fh->gen_id ));
198
199 return fsp;
200}
201
202/****************************************************************************
203 Attempt to set an kernel oplock on a file.
204****************************************************************************/
205
206static bool irix_set_kernel_oplock(struct kernel_oplocks *_ctx,
207 files_struct *fsp, int oplock_type)
208{
209 struct irix_oplocks_context *ctx = talloc_get_type(_ctx->private_data,
210 struct irix_oplocks_context);
211
212 if (sys_fcntl_long(fsp->fh->fd, F_OPLKREG, ctx->write_fd) == -1) {
213 if(errno != EAGAIN) {
214 DEBUG(0,("irix_set_kernel_oplock: Unable to get "
215 "kernel oplock on file %s, file_id %s "
216 "gen_id = %ul. Error was %s\n",
217 fsp_str_dbg(fsp),
218 file_id_string_tos(&fsp->file_id),
219 fsp->fh->gen_id,
220 strerror(errno) ));
221 } else {
222 DEBUG(5,("irix_set_kernel_oplock: Refused oplock on "
223 "file %s, fd = %d, file_id = %s, "
224 "gen_id = %ul. Another process had the file "
225 "open.\n",
226 fsp_str_dbg(fsp), fsp->fh->fd,
227 file_id_string_tos(&fsp->file_id),
228 fsp->fh->gen_id ));
229 }
230 return False;
231 }
232
233 DEBUG(10,("irix_set_kernel_oplock: got kernel oplock on file %s, file_id = %s "
234 "gen_id = %ul\n",
235 fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
236 fsp->fh->gen_id));
237
238 return True;
239}
240
241/****************************************************************************
242 Release a kernel oplock on a file.
243****************************************************************************/
244
245static void irix_release_kernel_oplock(struct kernel_oplocks *_ctx,
246 files_struct *fsp, int oplock_type)
247{
248 if (DEBUGLVL(10)) {
249 /*
250 * Check and print out the current kernel
251 * oplock state of this file.
252 */
253 int state = sys_fcntl_long(fsp->fh->fd, F_OPLKACK, -1);
254 dbgtext("irix_release_kernel_oplock: file %s, file_id = %s"
255 "gen_id = %ul, has kernel oplock state "
256 "of %x.\n", fsp_str_dbg(fsp),
257 file_id_string_tos(&fsp->file_id),
258 fsp->fh->gen_id, state );
259 }
260
261 /*
262 * Remove the kernel oplock on this file.
263 */
264 if(sys_fcntl_long(fsp->fh->fd, F_OPLKACK, OP_REVOKE) < 0) {
265 if( DEBUGLVL( 0 )) {
266 dbgtext("irix_release_kernel_oplock: Error when "
267 "removing kernel oplock on file " );
268 dbgtext("%s, file_id = %s gen_id = %ul. "
269 "Error was %s\n",
270 fsp_str_dbg(fsp),
271 file_id_string_tos(&fsp->file_id),
272 fsp->fh->gen_id,
273 strerror(errno) );
274 }
275 }
276}
277
278static void irix_oplocks_read_fde_handler(struct event_context *ev,
279 struct fd_event *fde,
280 uint16_t flags,
281 void *private_data)
282{
283 struct irix_oplocks_context *ctx = talloc_get_type(private_data,
284 struct irix_oplocks_context);
285 files_struct *fsp;
286
287 fsp = irix_oplock_receive_message(ctx->ctx);
288 break_kernel_oplock(fsp->conn->sconn->msg_ctx, fsp);
289}
290
291/****************************************************************************
292 Setup kernel oplocks.
293****************************************************************************/
294
295static const struct kernel_oplocks_ops irix_koplocks = {
296 .set_oplock = irix_set_kernel_oplock,
297 .release_oplock = irix_release_kernel_oplock,
298 .contend_level2_oplocks_begin = NULL,
299 .contend_level2_oplocks_end = NULL,
300};
301
302struct kernel_oplocks *irix_init_kernel_oplocks(TALLOC_CTX *mem_ctx)
303{
304 struct kernel_oplocks *_ctx;
305 struct irix_oplocks_context *ctx;
306 int pfd[2];
307
308 if (!irix_oplocks_available())
309 return NULL;
310
311 _ctx = talloc_zero(mem_ctx, struct kernel_oplocks);
312 if (!_ctx) {
313 return NULL;
314 }
315
316 ctx = talloc_zero(_ctx, struct irix_oplocks_context);
317 if (!ctx) {
318 talloc_free(_ctx);
319 return NULL;
320 }
321 _ctx->ops = &irix_koplocks;
322 _ctx->private_data = ctx;
323 ctx->ctx = _ctx;
324
325 if(pipe(pfd) != 0) {
326 talloc_free(_ctx);
327 DEBUG(0,("setup_kernel_oplock_pipe: Unable to create pipe. "
328 "Error was %s\n", strerror(errno) ));
329 return False;
330 }
331
332 ctx->read_fd = pfd[0];
333 ctx->write_fd = pfd[1];
334
335 ctx->read_fde = event_add_fd(smbd_event_context(),
336 ctx,
337 ctx->read_fd,
338 EVENT_FD_READ,
339 irix_oplocks_read_fde_handler,
340 ctx);
341 return _ctx;
342}
343#else
344 void oplock_irix_dummy(void);
345 void oplock_irix_dummy(void) {}
346#endif /* HAVE_KERNEL_OPLOCKS_IRIX */
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