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r19797: Convert the remaining pipes to the "new" unique out ptr handling
[Samba.git] / source / locking / posix.c
blob806018da8161d13ab474c2c80e1d68127f3b92a6
1 /*
2 Unix SMB/CIFS implementation.
3 Locking functions
4 Copyright (C) Jeremy Allison 1992-2006
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 2 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, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19
20 Revision History:
21
22 POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
23 */
24
25 #include "includes.h"
26
27 #undef DBGC_CLASS
28 #define DBGC_CLASS DBGC_LOCKING
29
30 /*
31 * The pending close database handle.
32 */
33
34 static TDB_CONTEXT *posix_pending_close_tdb;
35
36 /****************************************************************************
37 First - the functions that deal with the underlying system locks - these
38 functions are used no matter if we're mapping CIFS Windows locks or CIFS
39 POSIX locks onto POSIX.
40 ****************************************************************************/
41
42 /****************************************************************************
43 Utility function to map a lock type correctly depending on the open
44 mode of a file.
45 ****************************************************************************/
46
47 static int map_posix_lock_type( files_struct *fsp, enum brl_type lock_type)
48 {
49 if((lock_type == WRITE_LOCK) && !fsp->can_write) {
50 /*
51 * Many UNIX's cannot get a write lock on a file opened read-only.
52 * Win32 locking semantics allow this.
53 * Do the best we can and attempt a read-only lock.
54 */
55 DEBUG(10,("map_posix_lock_type: Downgrading write lock to read due to read-only file.\n"));
56 return F_RDLCK;
57 }
58
59 /*
60 * This return should be the most normal, as we attempt
61 * to always open files read/write.
62 */
63
64 return (lock_type == READ_LOCK) ? F_RDLCK : F_WRLCK;
65 }
66
67 /****************************************************************************
68 Debugging aid :-).
69 ****************************************************************************/
70
71 static const char *posix_lock_type_name(int lock_type)
72 {
73 return (lock_type == F_RDLCK) ? "READ" : "WRITE";
74 }
75
76 /****************************************************************************
77 Check to see if the given unsigned lock range is within the possible POSIX
78 range. Modifies the given args to be in range if possible, just returns
79 False if not.
80 ****************************************************************************/
81
82 static BOOL posix_lock_in_range(SMB_OFF_T *offset_out, SMB_OFF_T *count_out,
83 SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count)
84 {
85 SMB_OFF_T offset = (SMB_OFF_T)u_offset;
86 SMB_OFF_T count = (SMB_OFF_T)u_count;
87
88 /*
89 * For the type of system we are, attempt to
90 * find the maximum positive lock offset as an SMB_OFF_T.
91 */
92
93 #if defined(MAX_POSITIVE_LOCK_OFFSET) /* Some systems have arbitrary limits. */
94
95 SMB_OFF_T max_positive_lock_offset = (MAX_POSITIVE_LOCK_OFFSET);
96
97 #elif defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
98
99 /*
100 * In this case SMB_OFF_T is 64 bits,
101 * and the underlying system can handle 64 bit signed locks.
102 */
103
104 SMB_OFF_T mask2 = ((SMB_OFF_T)0x4) << (SMB_OFF_T_BITS-4);
105 SMB_OFF_T mask = (mask2<<1);
106 SMB_OFF_T max_positive_lock_offset = ~mask;
107
108 #else /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
109
110 /*
111 * In this case either SMB_OFF_T is 32 bits,
112 * or the underlying system cannot handle 64 bit signed locks.
113 * All offsets & counts must be 2^31 or less.
114 */
115
116 SMB_OFF_T max_positive_lock_offset = 0x7FFFFFFF;
117
118 #endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
119
120 /*
121 * POSIX locks of length zero mean lock to end-of-file.
122 * Win32 locks of length zero are point probes. Ignore
123 * any Win32 locks of length zero. JRA.
124 */
125
126 if (count == (SMB_OFF_T)0) {
127 DEBUG(10,("posix_lock_in_range: count = 0, ignoring.\n"));
128 return False;
129 }
130
131 /*
132 * If the given offset was > max_positive_lock_offset then we cannot map this at all
133 * ignore this lock.
134 */
135
136 if (u_offset & ~((SMB_BIG_UINT)max_positive_lock_offset)) {
137 DEBUG(10,("posix_lock_in_range: (offset = %.0f) offset > %.0f and we cannot handle this. Ignoring lock.\n",
138 (double)u_offset, (double)((SMB_BIG_UINT)max_positive_lock_offset) ));
139 return False;
140 }
141
142 /*
143 * We must truncate the count to less than max_positive_lock_offset.
144 */
145
146 if (u_count & ~((SMB_BIG_UINT)max_positive_lock_offset)) {
147 count = max_positive_lock_offset;
148 }
149
150 /*
151 * Truncate count to end at max lock offset.
152 */
153
154 if (offset + count < 0 || offset + count > max_positive_lock_offset) {
155 count = max_positive_lock_offset - offset;
156 }
157
158 /*
159 * If we ate all the count, ignore this lock.
160 */
161
162 if (count == 0) {
163 DEBUG(10,("posix_lock_in_range: Count = 0. Ignoring lock u_offset = %.0f, u_count = %.0f\n",
164 (double)u_offset, (double)u_count ));
165 return False;
166 }
167
168 /*
169 * The mapping was successful.
170 */
171
172 DEBUG(10,("posix_lock_in_range: offset_out = %.0f, count_out = %.0f\n",
173 (double)offset, (double)count ));
174
175 *offset_out = offset;
176 *count_out = count;
177
178 return True;
179 }
180
181 /****************************************************************************
182 Actual function that does POSIX locks. Copes with 64 -> 32 bit cruft and
183 broken NFS implementations.
184 ****************************************************************************/
185
186 static BOOL posix_fcntl_lock(files_struct *fsp, int op, SMB_OFF_T offset, SMB_OFF_T count, int type)
187 {
188 BOOL ret;
189
190 DEBUG(8,("posix_fcntl_lock %d %d %.0f %.0f %d\n",fsp->fh->fd,op,(double)offset,(double)count,type));
191
192 ret = SMB_VFS_LOCK(fsp,fsp->fh->fd,op,offset,count,type);
193
194 if (!ret && ((errno == EFBIG) || (errno == ENOLCK) || (errno == EINVAL))) {
195
196 DEBUG(0,("posix_fcntl_lock: WARNING: lock request at offset %.0f, length %.0f returned\n",
197 (double)offset,(double)count));
198 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno)));
199 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
200
201 /*
202 * If the offset is > 0x7FFFFFFF then this will cause problems on
203 * 32 bit NFS mounted filesystems. Just ignore it.
204 */
205
206 if (offset & ~((SMB_OFF_T)0x7fffffff)) {
207 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
208 return True;
209 }
210
211 if (count & ~((SMB_OFF_T)0x7fffffff)) {
212 /* 32 bit NFS file system, retry with smaller offset */
213 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
214 errno = 0;
215 count &= 0x7fffffff;
216 ret = SMB_VFS_LOCK(fsp,fsp->fh->fd,op,offset,count,type);
217 }
218 }
219
220 DEBUG(8,("posix_fcntl_lock: Lock call %s\n", ret ? "successful" : "failed"));
221 return ret;
222 }
223
224 /****************************************************************************
225 Actual function that gets POSIX locks. Copes with 64 -> 32 bit cruft and
226 broken NFS implementations.
227 ****************************************************************************/
228
229 static BOOL posix_fcntl_getlock(files_struct *fsp, SMB_OFF_T *poffset, SMB_OFF_T *pcount, int *ptype)
230 {
231 pid_t pid;
232 BOOL ret;
233
234 DEBUG(8,("posix_fcntl_getlock %d %.0f %.0f %d\n",
235 fsp->fh->fd,(double)*poffset,(double)*pcount,*ptype));
236
237 ret = SMB_VFS_GETLOCK(fsp,fsp->fh->fd,poffset,pcount,ptype,&pid);
238
239 if (!ret && ((errno == EFBIG) || (errno == ENOLCK) || (errno == EINVAL))) {
240
241 DEBUG(0,("posix_fcntl_getlock: WARNING: lock request at offset %.0f, length %.0f returned\n",
242 (double)*poffset,(double)*pcount));
243 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno)));
244 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
245
246 /*
247 * If the offset is > 0x7FFFFFFF then this will cause problems on
248 * 32 bit NFS mounted filesystems. Just ignore it.
249 */
250
251 if (*poffset & ~((SMB_OFF_T)0x7fffffff)) {
252 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
253 return True;
254 }
255
256 if (*pcount & ~((SMB_OFF_T)0x7fffffff)) {
257 /* 32 bit NFS file system, retry with smaller offset */
258 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
259 errno = 0;
260 *pcount &= 0x7fffffff;
261 ret = SMB_VFS_GETLOCK(fsp,fsp->fh->fd,poffset,pcount,ptype,&pid);
262 }
263 }
264
265 DEBUG(8,("posix_fcntl_getlock: Lock query call %s\n", ret ? "successful" : "failed"));
266 return ret;
267 }
268
269 /****************************************************************************
270 POSIX function to see if a file region is locked. Returns True if the
271 region is locked, False otherwise.
272 ****************************************************************************/
273
274 BOOL is_posix_locked(files_struct *fsp,
275 SMB_BIG_UINT *pu_offset,
276 SMB_BIG_UINT *pu_count,
277 enum brl_type *plock_type,
278 enum brl_flavour lock_flav)
279 {
280 SMB_OFF_T offset;
281 SMB_OFF_T count;
282 int posix_lock_type = map_posix_lock_type(fsp,*plock_type);
283
284 DEBUG(10,("is_posix_locked: File %s, offset = %.0f, count = %.0f, type = %s\n",
285 fsp->fsp_name, (double)*pu_offset, (double)*pu_count, posix_lock_type_name(*plock_type) ));
286
287 /*
288 * If the requested lock won't fit in the POSIX range, we will
289 * never set it, so presume it is not locked.
290 */
291
292 if(!posix_lock_in_range(&offset, &count, *pu_offset, *pu_count)) {
293 return False;
294 }
295
296 if (!posix_fcntl_getlock(fsp,&offset,&count,&posix_lock_type)) {
297 return False;
298 }
299
300 if (posix_lock_type == F_UNLCK) {
301 return False;
302 }
303
304 if (lock_flav == POSIX_LOCK) {
305 /* Only POSIX lock queries need to know the details. */
306 *pu_offset = (SMB_BIG_UINT)offset;
307 *pu_count = (SMB_BIG_UINT)count;
308 *plock_type = (posix_lock_type == F_RDLCK) ? READ_LOCK : WRITE_LOCK;
309 }
310 return True;
311 }
312
313 /****************************************************************************
314 Next - the functions that deal with in memory database storing representations
315 of either Windows CIFS locks or POSIX CIFS locks.
316 ****************************************************************************/
317
318 /* The key used in the in-memory POSIX databases. */
319
320 struct lock_ref_count_key {
321 SMB_DEV_T device;
322 SMB_INO_T inode;
323 char r;
324 };
325
326 struct fd_key {
327 SMB_DEV_T device;
328 SMB_INO_T inode;
329 };
330
331 /*******************************************************************
332 Form a static locking key for a dev/inode pair for the fd array.
333 ******************************************************************/
334
335 static TDB_DATA fd_array_key(SMB_DEV_T dev, SMB_INO_T inode)
336 {
337 static struct fd_key key;
338 TDB_DATA kbuf;
339
340 memset(&key, '\0', sizeof(key));
341 key.device = dev;
342 key.inode = inode;
343 kbuf.dptr = (char *)&key;
344 kbuf.dsize = sizeof(key);
345 return kbuf;
346 }
347
348 /*******************************************************************
349 Form a static locking key for a dev/inode pair for the lock ref count
350 ******************************************************************/
351
352 static TDB_DATA locking_ref_count_key(SMB_DEV_T dev, SMB_INO_T inode)
353 {
354 static struct lock_ref_count_key key;
355 TDB_DATA kbuf;
356
357 memset(&key, '\0', sizeof(key));
358 key.device = dev;
359 key.inode = inode;
360 key.r = 'r';
361 kbuf.dptr = (char *)&key;
362 kbuf.dsize = sizeof(key);
363 return kbuf;
364 }
365
366 /*******************************************************************
367 Convenience function to get an fd_array key from an fsp.
368 ******************************************************************/
369
370 static TDB_DATA fd_array_key_fsp(files_struct *fsp)
371 {
372 return fd_array_key(fsp->dev, fsp->inode);
373 }
374
375 /*******************************************************************
376 Convenience function to get a lock ref count key from an fsp.
377 ******************************************************************/
378
379 static TDB_DATA locking_ref_count_key_fsp(files_struct *fsp)
380 {
381 return locking_ref_count_key(fsp->dev, fsp->inode);
382 }
383
384 /*******************************************************************
385 Create the in-memory POSIX lock databases.
386 ********************************************************************/
387
388 BOOL posix_locking_init(int read_only)
389 {
390 if (posix_pending_close_tdb) {
391 return True;
392 }
393
394 if (!posix_pending_close_tdb) {
395 posix_pending_close_tdb = tdb_open_log(NULL, 0, TDB_INTERNAL,
396 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644);
397 }
398 if (!posix_pending_close_tdb) {
399 DEBUG(0,("Failed to open POSIX pending close database.\n"));
400 return False;
401 }
402
403 return True;
404 }
405
406 /*******************************************************************
407 Delete the in-memory POSIX lock databases.
408 ********************************************************************/
409
410 BOOL posix_locking_end(void)
411 {
412 if (posix_pending_close_tdb && tdb_close(posix_pending_close_tdb) != 0) {
413 return False;
414 }
415 return True;
416 }
417
418 /****************************************************************************
419 Next - the functions that deal with storing fd's that have outstanding
420 POSIX locks when closed.
421 ****************************************************************************/
422
423 /****************************************************************************
424 The records in posix_pending_close_tdb are composed of an array of ints
425 keyed by dev/ino pair.
426 The first int is a reference count of the number of outstanding locks on
427 all open fd's on this dev/ino pair. Any subsequent ints are the fd's that
428 were open on this dev/ino pair that should have been closed, but can't as
429 the lock ref count is non zero.
430 ****************************************************************************/
431
432 /****************************************************************************
433 Keep a reference count of the number of Windows locks open on this dev/ino
434 pair. Creates entry if it doesn't exist.
435 ****************************************************************************/
436
437 static void increment_windows_lock_ref_count(files_struct *fsp)
438 {
439 TDB_DATA kbuf = locking_ref_count_key_fsp(fsp);
440 TDB_DATA dbuf;
441 int lock_ref_count;
442
443 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
444 if (dbuf.dptr == NULL) {
445 dbuf.dptr = (char *)SMB_MALLOC_P(int);
446 if (!dbuf.dptr) {
447 smb_panic("increment_windows_lock_ref_count: malloc fail.\n");
448 }
449 memset(dbuf.dptr, '\0', sizeof(int));
450 dbuf.dsize = sizeof(int);
451 }
452
453 memcpy(&lock_ref_count, dbuf.dptr, sizeof(int));
454 lock_ref_count++;
455 memcpy(dbuf.dptr, &lock_ref_count, sizeof(int));
456
457 if (tdb_store(posix_pending_close_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
458 smb_panic("increment_windows_lock_ref_count: tdb_store_fail.\n");
459 }
460 SAFE_FREE(dbuf.dptr);
461
462 DEBUG(10,("increment_windows_lock_ref_count for file now %s = %d\n",
463 fsp->fsp_name, lock_ref_count ));
464 }
465
466 static void decrement_windows_lock_ref_count(files_struct *fsp)
467 {
468 TDB_DATA kbuf = locking_ref_count_key_fsp(fsp);
469 TDB_DATA dbuf;
470 int lock_ref_count;
471
472 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
473 if (!dbuf.dptr) {
474 smb_panic("decrement_windows_lock_ref_count: logic error.\n");
475 }
476
477 memcpy(&lock_ref_count, dbuf.dptr, sizeof(int));
478 lock_ref_count--;
479 memcpy(dbuf.dptr, &lock_ref_count, sizeof(int));
480
481 if (lock_ref_count < 0) {
482 smb_panic("decrement_windows_lock_ref_count: lock_count logic error.\n");
483 }
484
485 if (tdb_store(posix_pending_close_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
486 smb_panic("decrement_windows_lock_ref_count: tdb_store_fail.\n");
487 }
488 SAFE_FREE(dbuf.dptr);
489
490 DEBUG(10,("decrement_windows_lock_ref_count for file now %s = %d\n",
491 fsp->fsp_name, lock_ref_count ));
492 }
493
494 /****************************************************************************
495 Bulk delete - subtract as many locks as we've just deleted.
496 ****************************************************************************/
497
498 void reduce_windows_lock_ref_count(files_struct *fsp, unsigned int dcount)
499 {
500 TDB_DATA kbuf = locking_ref_count_key_fsp(fsp);
501 TDB_DATA dbuf;
502 int lock_ref_count;
503
504 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
505 if (!dbuf.dptr) {
506 return;
507 }
508
509 memcpy(&lock_ref_count, dbuf.dptr, sizeof(int));
510 lock_ref_count -= dcount;
511
512 if (lock_ref_count < 0) {
513 smb_panic("reduce_windows_lock_ref_count: lock_count logic error.\n");
514 }
515 memcpy(dbuf.dptr, &lock_ref_count, sizeof(int));
516
517 if (tdb_store(posix_pending_close_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
518 smb_panic("reduce_windows_lock_ref_count: tdb_store_fail.\n");
519 }
520 SAFE_FREE(dbuf.dptr);
521
522 DEBUG(10,("reduce_windows_lock_ref_count for file now %s = %d\n",
523 fsp->fsp_name, lock_ref_count ));
524 }
525
526 /****************************************************************************
527 Fetch the lock ref count.
528 ****************************************************************************/
529
530 static int get_windows_lock_ref_count(files_struct *fsp)
531 {
532 TDB_DATA kbuf = locking_ref_count_key_fsp(fsp);
533 TDB_DATA dbuf;
534 int lock_ref_count;
535
536 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
537 if (!dbuf.dptr) {
538 lock_ref_count = 0;
539 } else {
540 memcpy(&lock_ref_count, dbuf.dptr, sizeof(int));
541 }
542 SAFE_FREE(dbuf.dptr);
543
544 DEBUG(10,("get_windows_lock_count for file %s = %d\n",
545 fsp->fsp_name, lock_ref_count ));
546 return lock_ref_count;
547 }
548
549 /****************************************************************************
550 Delete a lock_ref_count entry.
551 ****************************************************************************/
552
553 static void delete_windows_lock_ref_count(files_struct *fsp)
554 {
555 TDB_DATA kbuf = locking_ref_count_key_fsp(fsp);
556
557 /* Not a bug if it doesn't exist - no locks were ever granted. */
558 tdb_delete(posix_pending_close_tdb, kbuf);
559 DEBUG(10,("delete_windows_lock_ref_count for file %s\n", fsp->fsp_name));
560 }
561
562 /****************************************************************************
563 Add an fd to the pending close tdb.
564 ****************************************************************************/
565
566 static void add_fd_to_close_entry(files_struct *fsp)
567 {
568 TDB_DATA kbuf = fd_array_key_fsp(fsp);
569 TDB_DATA dbuf;
570
571 dbuf.dptr = NULL;
572 dbuf.dsize = 0;
573
574 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
575
576 dbuf.dptr = (char *)SMB_REALLOC(dbuf.dptr, dbuf.dsize + sizeof(int));
577 if (!dbuf.dptr) {
578 smb_panic("add_fd_to_close_entry: Realloc fail !\n");
579 }
580
581 memcpy(dbuf.dptr + dbuf.dsize, &fsp->fh->fd, sizeof(int));
582 dbuf.dsize += sizeof(int);
583
584 if (tdb_store(posix_pending_close_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
585 smb_panic("add_fd_to_close_entry: tdb_store_fail.\n");
586 }
587
588 DEBUG(10,("add_fd_to_close_entry: added fd %d file %s\n",
589 fsp->fh->fd, fsp->fsp_name ));
590
591 SAFE_FREE(dbuf.dptr);
592 }
593
594 /****************************************************************************
595 Remove all fd entries for a specific dev/inode pair from the tdb.
596 ****************************************************************************/
597
598 static void delete_close_entries(files_struct *fsp)
599 {
600 TDB_DATA kbuf = fd_array_key_fsp(fsp);
601
602 if (tdb_delete(posix_pending_close_tdb, kbuf) == -1) {
603 smb_panic("delete_close_entries: tdb_delete fail !\n");
604 }
605 }
606
607 /****************************************************************************
608 Get the array of POSIX pending close records for an open fsp. Caller must
609 free. Returns number of entries.
610 ****************************************************************************/
611
612 static size_t get_posix_pending_close_entries(files_struct *fsp, int **entries)
613 {
614 TDB_DATA kbuf = fd_array_key_fsp(fsp);
615 TDB_DATA dbuf;
616 size_t count = 0;
617
618 *entries = NULL;
619 dbuf.dptr = NULL;
620
621 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
622
623 if (!dbuf.dptr) {
624 return 0;
625 }
626
627 *entries = (int *)dbuf.dptr;
628 count = (size_t)(dbuf.dsize / sizeof(int));
629
630 return count;
631 }
632
633 /****************************************************************************
634 Deal with pending closes needed by POSIX locking support.
635 Note that posix_locking_close_file() is expected to have been called
636 to delete all locks on this fsp before this function is called.
637 ****************************************************************************/
638
639 int fd_close_posix(struct connection_struct *conn, files_struct *fsp)
640 {
641 int saved_errno = 0;
642 int ret;
643 int *fd_array = NULL;
644 size_t count, i;
645
646 if (!lp_locking(fsp->conn->params) || !lp_posix_locking(conn->params)) {
647 /*
648 * No locking or POSIX to worry about or we want POSIX semantics
649 * which will lose all locks on all fd's open on this dev/inode,
650 * just close.
651 */
652 ret = SMB_VFS_CLOSE(fsp,fsp->fh->fd);
653 fsp->fh->fd = -1;
654 return ret;
655 }
656
657 if (get_windows_lock_ref_count(fsp)) {
658
659 /*
660 * There are outstanding locks on this dev/inode pair on other fds.
661 * Add our fd to the pending close tdb and set fsp->fh->fd to -1.
662 */
663
664 add_fd_to_close_entry(fsp);
665 fsp->fh->fd = -1;
666 return 0;
667 }
668
669 /*
670 * No outstanding locks. Get the pending close fd's
671 * from the tdb and close them all.
672 */
673
674 count = get_posix_pending_close_entries(fsp, &fd_array);
675
676 if (count) {
677 DEBUG(10,("fd_close_posix: doing close on %u fd's.\n", (unsigned int)count ));
678
679 for(i = 0; i < count; i++) {
680 if (SMB_VFS_CLOSE(fsp,fd_array[i]) == -1) {
681 saved_errno = errno;
682 }
683 }
684
685 /*
686 * Delete all fd's stored in the tdb
687 * for this dev/inode pair.
688 */
689
690 delete_close_entries(fsp);
691 }
692
693 SAFE_FREE(fd_array);
694
695 /* Don't need a lock ref count on this dev/ino anymore. */
696 delete_windows_lock_ref_count(fsp);
697
698 /*
699 * Finally close the fd associated with this fsp.
700 */
701
702 ret = SMB_VFS_CLOSE(fsp,fsp->fh->fd);
703
704 if (saved_errno != 0) {
705 errno = saved_errno;
706 ret = -1;
707 }
708
709 fsp->fh->fd = -1;
710
711 return ret;
712 }
713
714 /****************************************************************************
715 Next - the functions that deal with the mapping CIFS Windows locks onto
716 the underlying system POSIX locks.
717 ****************************************************************************/
718
719 /*
720 * Structure used when splitting a lock range
721 * into a POSIX lock range. Doubly linked list.
722 */
723
724 struct lock_list {
725 struct lock_list *next;
726 struct lock_list *prev;
727 SMB_OFF_T start;
728 SMB_OFF_T size;
729 };
730
731 /****************************************************************************
732 Create a list of lock ranges that don't overlap a given range. Used in calculating
733 POSIX locks and unlocks. This is a difficult function that requires ASCII art to
734 understand it :-).
735 ****************************************************************************/
736
737 static struct lock_list *posix_lock_list(TALLOC_CTX *ctx,
738 struct lock_list *lhead,
739 const struct lock_context *lock_ctx, /* Lock context lhead belongs to. */
740 files_struct *fsp,
741 const struct lock_struct *plocks,
742 int num_locks)
743 {
744 int i;
745
746 /*
747 * Check the current lock list on this dev/inode pair.
748 * Quit if the list is deleted.
749 */
750
751 DEBUG(10,("posix_lock_list: curr: start=%.0f,size=%.0f\n",
752 (double)lhead->start, (double)lhead->size ));
753
754 for (i=0; i<num_locks && lhead; i++) {
755 const struct lock_struct *lock = &plocks[i];
756 struct lock_list *l_curr;
757
758 /* Ignore all but read/write locks. */
759 if (lock->lock_type != READ_LOCK && lock->lock_type != WRITE_LOCK) {
760 continue;
761 }
762
763 /* Ignore locks not owned by this process. */
764 if (!procid_equal(&lock->context.pid, &lock_ctx->pid)) {
765 continue;
766 }
767
768 /*
769 * Walk the lock list, checking for overlaps. Note that
770 * the lock list can expand within this loop if the current
771 * range being examined needs to be split.
772 */
773
774 for (l_curr = lhead; l_curr;) {
775
776 DEBUG(10,("posix_lock_list: lock: fnum=%d: start=%.0f,size=%.0f:type=%s", lock->fnum,
777 (double)lock->start, (double)lock->size, posix_lock_type_name(lock->lock_type) ));
778
779 if ( (l_curr->start >= (lock->start + lock->size)) ||
780 (lock->start >= (l_curr->start + l_curr->size))) {
781
782 /* No overlap with existing lock - leave this range alone. */
783 /*********************************************
784 +---------+
785 | l_curr |
786 +---------+
787 +-------+
788 | lock |
789 +-------+
790 OR....
791 +---------+
792 | l_curr |
793 +---------+
794 **********************************************/
795
796 DEBUG(10,(" no overlap case.\n" ));
797
798 l_curr = l_curr->next;
799
800 } else if ( (l_curr->start >= lock->start) &&
801 (l_curr->start + l_curr->size <= lock->start + lock->size) ) {
802
803 /*
804 * This range is completely overlapped by this existing lock range
805 * and thus should have no effect. Delete it from the list.
806 */
807 /*********************************************
808 +---------+
809 | l_curr |
810 +---------+
811 +---------------------------+
812 | lock |
813 +---------------------------+
814 **********************************************/
815 /* Save the next pointer */
816 struct lock_list *ul_next = l_curr->next;
817
818 DEBUG(10,(" delete case.\n" ));
819
820 DLIST_REMOVE(lhead, l_curr);
821 if(lhead == NULL) {
822 break; /* No more list... */
823 }
824
825 l_curr = ul_next;
826
827 } else if ( (l_curr->start >= lock->start) &&
828 (l_curr->start < lock->start + lock->size) &&
829 (l_curr->start + l_curr->size > lock->start + lock->size) ) {
830
831 /*
832 * This range overlaps the existing lock range at the high end.
833 * Truncate by moving start to existing range end and reducing size.
834 */
835 /*********************************************
836 +---------------+
837 | l_curr |
838 +---------------+
839 +---------------+
840 | lock |
841 +---------------+
842 BECOMES....
843 +-------+
844 | l_curr|
845 +-------+
846 **********************************************/
847
848 l_curr->size = (l_curr->start + l_curr->size) - (lock->start + lock->size);
849 l_curr->start = lock->start + lock->size;
850
851 DEBUG(10,(" truncate high case: start=%.0f,size=%.0f\n",
852 (double)l_curr->start, (double)l_curr->size ));
853
854 l_curr = l_curr->next;
855
856 } else if ( (l_curr->start < lock->start) &&
857 (l_curr->start + l_curr->size > lock->start) &&
858 (l_curr->start + l_curr->size <= lock->start + lock->size) ) {
859
860 /*
861 * This range overlaps the existing lock range at the low end.
862 * Truncate by reducing size.
863 */
864 /*********************************************
865 +---------------+
866 | l_curr |
867 +---------------+
868 +---------------+
869 | lock |
870 +---------------+
871 BECOMES....
872 +-------+
873 | l_curr|
874 +-------+
875 **********************************************/
876
877 l_curr->size = lock->start - l_curr->start;
878
879 DEBUG(10,(" truncate low case: start=%.0f,size=%.0f\n",
880 (double)l_curr->start, (double)l_curr->size ));
881
882 l_curr = l_curr->next;
883
884 } else if ( (l_curr->start < lock->start) &&
885 (l_curr->start + l_curr->size > lock->start + lock->size) ) {
886 /*
887 * Worst case scenario. Range completely overlaps an existing
888 * lock range. Split the request into two, push the new (upper) request
889 * into the dlink list, and continue with the entry after l_new (as we
890 * know that l_new will not overlap with this lock).
891 */
892 /*********************************************
893 +---------------------------+
894 | l_curr |
895 +---------------------------+
896 +---------+
897 | lock |
898 +---------+
899 BECOMES.....
900 +-------+ +---------+
901 | l_curr| | l_new |
902 +-------+ +---------+
903 **********************************************/
904 struct lock_list *l_new = TALLOC_P(ctx, struct lock_list);
905
906 if(l_new == NULL) {
907 DEBUG(0,("posix_lock_list: talloc fail.\n"));
908 return NULL; /* The talloc_destroy takes care of cleanup. */
909 }
910
911 ZERO_STRUCTP(l_new);
912 l_new->start = lock->start + lock->size;
913 l_new->size = l_curr->start + l_curr->size - l_new->start;
914
915 /* Truncate the l_curr. */
916 l_curr->size = lock->start - l_curr->start;
917
918 DEBUG(10,(" split case: curr: start=%.0f,size=%.0f \
919 new: start=%.0f,size=%.0f\n", (double)l_curr->start, (double)l_curr->size,
920 (double)l_new->start, (double)l_new->size ));
921
922 /*
923 * Add into the dlink list after the l_curr point - NOT at lhead.
924 * Note we can't use DLINK_ADD here as this inserts at the head of the given list.
925 */
926
927 l_new->prev = l_curr;
928 l_new->next = l_curr->next;
929 l_curr->next = l_new;
930
931 /* And move after the link we added. */
932 l_curr = l_new->next;
933
934 } else {
935
936 /*
937 * This logic case should never happen. Ensure this is the
938 * case by forcing an abort.... Remove in production.
939 */
940 pstring msg;
941
942 slprintf(msg, sizeof(msg)-1, "logic flaw in cases: l_curr: start = %.0f, size = %.0f : \
943 lock: start = %.0f, size = %.0f\n", (double)l_curr->start, (double)l_curr->size, (double)lock->start, (double)lock->size );
944
945 smb_panic(msg);
946 }
947 } /* end for ( l_curr = lhead; l_curr;) */
948 } /* end for (i=0; i<num_locks && ul_head; i++) */
949
950 return lhead;
951 }
952
953 /****************************************************************************
954 POSIX function to acquire a lock. Returns True if the
955 lock could be granted, False if not.
956 ****************************************************************************/
957
958 BOOL set_posix_lock_windows_flavour(files_struct *fsp,
959 SMB_BIG_UINT u_offset,
960 SMB_BIG_UINT u_count,
961 enum brl_type lock_type,
962 const struct lock_context *lock_ctx,
963 const struct lock_struct *plocks,
964 int num_locks,
965 int *errno_ret)
966 {
967 SMB_OFF_T offset;
968 SMB_OFF_T count;
969 int posix_lock_type = map_posix_lock_type(fsp,lock_type);
970 BOOL ret = True;
971 size_t lock_count;
972 TALLOC_CTX *l_ctx = NULL;
973 struct lock_list *llist = NULL;
974 struct lock_list *ll = NULL;
975
976 DEBUG(5,("set_posix_lock_windows_flavour: File %s, offset = %.0f, count = %.0f, type = %s\n",
977 fsp->fsp_name, (double)u_offset, (double)u_count, posix_lock_type_name(lock_type) ));
978
979 /*
980 * If the requested lock won't fit in the POSIX range, we will
981 * pretend it was successful.
982 */
983
984 if(!posix_lock_in_range(&offset, &count, u_offset, u_count)) {
985 increment_windows_lock_ref_count(fsp);
986 return True;
987 }
988
989 /*
990 * Windows is very strange. It allows read locks to be overlayed
991 * (even over a write lock), but leaves the write lock in force until the first
992 * unlock. It also reference counts the locks. This means the following sequence :
993 *
994 * process1 process2
995 * ------------------------------------------------------------------------
996 * WRITE LOCK : start = 2, len = 10
997 * READ LOCK: start =0, len = 10 - FAIL
998 * READ LOCK : start = 0, len = 14
999 * READ LOCK: start =0, len = 10 - FAIL
1000 * UNLOCK : start = 2, len = 10
1001 * READ LOCK: start =0, len = 10 - OK
1002 *
1003 * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
1004 * would leave a single read lock over the 0-14 region.
1005 */
1006
1007 if ((l_ctx = talloc_init("set_posix_lock")) == NULL) {
1008 DEBUG(0,("set_posix_lock_windows_flavour: unable to init talloc context.\n"));
1009 return False;
1010 }
1011
1012 if ((ll = TALLOC_P(l_ctx, struct lock_list)) == NULL) {
1013 DEBUG(0,("set_posix_lock_windows_flavour: unable to talloc unlock list.\n"));
1014 talloc_destroy(l_ctx);
1015 return False;
1016 }
1017
1018 /*
1019 * Create the initial list entry containing the
1020 * lock we want to add.
1021 */
1022
1023 ZERO_STRUCTP(ll);
1024 ll->start = offset;
1025 ll->size = count;
1026
1027 DLIST_ADD(llist, ll);
1028
1029 /*
1030 * The following call calculates if there are any
1031 * overlapping locks held by this process on
1032 * fd's open on the same file and splits this list
1033 * into a list of lock ranges that do not overlap with existing
1034 * POSIX locks.
1035 */
1036
1037 llist = posix_lock_list(l_ctx,
1038 llist,
1039 lock_ctx, /* Lock context llist belongs to. */
1040 fsp,
1041 plocks,
1042 num_locks);
1043
1044 /*
1045 * Add the POSIX locks on the list of ranges returned.
1046 * As the lock is supposed to be added atomically, we need to
1047 * back out all the locks if any one of these calls fail.
1048 */
1049
1050 for (lock_count = 0, ll = llist; ll; ll = ll->next, lock_count++) {
1051 offset = ll->start;
1052 count = ll->size;
1053
1054 DEBUG(5,("set_posix_lock_windows_flavour: Real lock: Type = %s: offset = %.0f, count = %.0f\n",
1055 posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
1056
1057 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,posix_lock_type)) {
1058 *errno_ret = errno;
1059 DEBUG(5,("set_posix_lock_windows_flavour: Lock fail !: Type = %s: offset = %.0f, count = %.0f. Errno = %s\n",
1060 posix_lock_type_name(posix_lock_type), (double)offset, (double)count, strerror(errno) ));
1061 ret = False;
1062 break;
1063 }
1064 }
1065
1066 if (!ret) {
1067
1068 /*
1069 * Back out all the POSIX locks we have on fail.
1070 */
1071
1072 for (ll = llist; lock_count; ll = ll->next, lock_count--) {
1073 offset = ll->start;
1074 count = ll->size;
1075
1076 DEBUG(5,("set_posix_lock_windows_flavour: Backing out locks: Type = %s: offset = %.0f, count = %.0f\n",
1077 posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
1078
1079 posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_UNLCK);
1080 }
1081 } else {
1082 /* Remember the number of Windows locks we have on this dev/ino pair. */
1083 increment_windows_lock_ref_count(fsp);
1084 }
1085
1086 talloc_destroy(l_ctx);
1087 return ret;
1088 }
1089
1090 /****************************************************************************
1091 POSIX function to release a lock. Returns True if the
1092 lock could be released, False if not.
1093 ****************************************************************************/
1094
1095 BOOL release_posix_lock_windows_flavour(files_struct *fsp,
1096 SMB_BIG_UINT u_offset,
1097 SMB_BIG_UINT u_count,
1098 enum brl_type deleted_lock_type,
1099 const struct lock_context *lock_ctx,
1100 const struct lock_struct *plocks,
1101 int num_locks)
1102 {
1103 SMB_OFF_T offset;
1104 SMB_OFF_T count;
1105 BOOL ret = True;
1106 TALLOC_CTX *ul_ctx = NULL;
1107 struct lock_list *ulist = NULL;
1108 struct lock_list *ul = NULL;
1109
1110 DEBUG(5,("release_posix_lock_windows_flavour: File %s, offset = %.0f, count = %.0f\n",
1111 fsp->fsp_name, (double)u_offset, (double)u_count ));
1112
1113 /* Remember the number of Windows locks we have on this dev/ino pair. */
1114 decrement_windows_lock_ref_count(fsp);
1115
1116 /*
1117 * If the requested lock won't fit in the POSIX range, we will
1118 * pretend it was successful.
1119 */
1120
1121 if(!posix_lock_in_range(&offset, &count, u_offset, u_count)) {
1122 return True;
1123 }
1124
1125 if ((ul_ctx = talloc_init("release_posix_lock")) == NULL) {
1126 DEBUG(0,("release_posix_lock_windows_flavour: unable to init talloc context.\n"));
1127 return False;
1128 }
1129
1130 if ((ul = TALLOC_P(ul_ctx, struct lock_list)) == NULL) {
1131 DEBUG(0,("release_posix_lock_windows_flavour: unable to talloc unlock list.\n"));
1132 talloc_destroy(ul_ctx);
1133 return False;
1134 }
1135
1136 /*
1137 * Create the initial list entry containing the
1138 * lock we want to remove.
1139 */
1140
1141 ZERO_STRUCTP(ul);
1142 ul->start = offset;
1143 ul->size = count;
1144
1145 DLIST_ADD(ulist, ul);
1146
1147 /*
1148 * The following call calculates if there are any
1149 * overlapping locks held by this process on
1150 * fd's open on the same file and creates a
1151 * list of unlock ranges that will allow
1152 * POSIX lock ranges to remain on the file whilst the
1153 * unlocks are performed.
1154 */
1155
1156 ulist = posix_lock_list(ul_ctx,
1157 ulist,
1158 lock_ctx, /* Lock context ulist belongs to. */
1159 fsp,
1160 plocks,
1161 num_locks);
1162
1163 /*
1164 * If there were any overlapped entries (list is > 1 or size or start have changed),
1165 * and the lock_type we just deleted from
1166 * the upper layer tdb was a write lock, then before doing the unlock we need to downgrade
1167 * the POSIX lock to a read lock. This allows any overlapping read locks
1168 * to be atomically maintained.
1169 */
1170
1171 if (deleted_lock_type == WRITE_LOCK &&
1172 (!ulist || ulist->next != NULL || ulist->start != offset || ulist->size != count)) {
1173
1174 DEBUG(5,("release_posix_lock_windows_flavour: downgrading lock to READ: offset = %.0f, count = %.0f\n",
1175 (double)offset, (double)count ));
1176
1177 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_RDLCK)) {
1178 DEBUG(0,("release_posix_lock_windows_flavour: downgrade of lock failed with error %s !\n", strerror(errno) ));
1179 talloc_destroy(ul_ctx);
1180 return False;
1181 }
1182 }
1183
1184 /*
1185 * Release the POSIX locks on the list of ranges returned.
1186 */
1187
1188 for(; ulist; ulist = ulist->next) {
1189 offset = ulist->start;
1190 count = ulist->size;
1191
1192 DEBUG(5,("release_posix_lock_windows_flavour: Real unlock: offset = %.0f, count = %.0f\n",
1193 (double)offset, (double)count ));
1194
1195 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_UNLCK)) {
1196 ret = False;
1197 }
1198 }
1199
1200 talloc_destroy(ul_ctx);
1201 return ret;
1202 }
1203
1204 /****************************************************************************
1205 Next - the functions that deal with mapping CIFS POSIX locks onto
1206 the underlying system POSIX locks.
1207 ****************************************************************************/
1208
1209 /****************************************************************************
1210 POSIX function to acquire a lock. Returns True if the
1211 lock could be granted, False if not.
1212 As POSIX locks don't stack or conflict (they just overwrite)
1213 we can map the requested lock directly onto a system one. We
1214 know it doesn't conflict with locks on other contexts as the
1215 upper layer would have refused it.
1216 ****************************************************************************/
1217
1218 BOOL set_posix_lock_posix_flavour(files_struct *fsp,
1219 SMB_BIG_UINT u_offset,
1220 SMB_BIG_UINT u_count,
1221 enum brl_type lock_type,
1222 int *errno_ret)
1223 {
1224 SMB_OFF_T offset;
1225 SMB_OFF_T count;
1226 int posix_lock_type = map_posix_lock_type(fsp,lock_type);
1227
1228 DEBUG(5,("set_posix_lock_posix_flavour: File %s, offset = %.0f, count = %.0f, type = %s\n",
1229 fsp->fsp_name, (double)u_offset, (double)u_count, posix_lock_type_name(lock_type) ));
1230
1231 /*
1232 * If the requested lock won't fit in the POSIX range, we will
1233 * pretend it was successful.
1234 */
1235
1236 if(!posix_lock_in_range(&offset, &count, u_offset, u_count)) {
1237 return True;
1238 }
1239
1240 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,posix_lock_type)) {
1241 *errno_ret = errno;
1242 DEBUG(5,("set_posix_lock_posix_flavour: Lock fail !: Type = %s: offset = %.0f, count = %.0f. Errno = %s\n",
1243 posix_lock_type_name(posix_lock_type), (double)offset, (double)count, strerror(errno) ));
1244 return False;
1245 }
1246 return True;
1247 }
1248
1249 /****************************************************************************
1250 POSIX function to release a lock. Returns True if the
1251 lock could be released, False if not.
1252 We are given a complete lock state from the upper layer which is what the lock
1253 state should be after the unlock has already been done, so what
1254 we do is punch out holes in the unlock range where locks owned by this process
1255 have a different lock context.
1256 ****************************************************************************/
1257
1258 BOOL release_posix_lock_posix_flavour(files_struct *fsp,
1259 SMB_BIG_UINT u_offset,
1260 SMB_BIG_UINT u_count,
1261 const struct lock_context *lock_ctx,
1262 const struct lock_struct *plocks,
1263 int num_locks)
1264 {
1265 BOOL ret = True;
1266 SMB_OFF_T offset;
1267 SMB_OFF_T count;
1268 TALLOC_CTX *ul_ctx = NULL;
1269 struct lock_list *ulist = NULL;
1270 struct lock_list *ul = NULL;
1271
1272 DEBUG(5,("release_posix_lock_posix_flavour: File %s, offset = %.0f, count = %.0f\n",
1273 fsp->fsp_name, (double)u_offset, (double)u_count ));
1274
1275 /*
1276 * If the requested lock won't fit in the POSIX range, we will
1277 * pretend it was successful.
1278 */
1279
1280 if(!posix_lock_in_range(&offset, &count, u_offset, u_count)) {
1281 return True;
1282 }
1283
1284 if ((ul_ctx = talloc_init("release_posix_lock")) == NULL) {
1285 DEBUG(0,("release_posix_lock_windows_flavour: unable to init talloc context.\n"));
1286 return False;
1287 }
1288
1289 if ((ul = TALLOC_P(ul_ctx, struct lock_list)) == NULL) {
1290 DEBUG(0,("release_posix_lock_windows_flavour: unable to talloc unlock list.\n"));
1291 talloc_destroy(ul_ctx);
1292 return False;
1293 }
1294
1295 /*
1296 * Create the initial list entry containing the
1297 * lock we want to remove.
1298 */
1299
1300 ZERO_STRUCTP(ul);
1301 ul->start = offset;
1302 ul->size = count;
1303
1304 DLIST_ADD(ulist, ul);
1305
1306 /*
1307 * Walk the given array creating a linked list
1308 * of unlock requests.
1309 */
1310
1311 ulist = posix_lock_list(ul_ctx,
1312 ulist,
1313 lock_ctx, /* Lock context ulist belongs to. */
1314 fsp,
1315 plocks,
1316 num_locks);
1317
1318 /*
1319 * Release the POSIX locks on the list of ranges returned.
1320 */
1321
1322 for(; ulist; ulist = ulist->next) {
1323 offset = ulist->start;
1324 count = ulist->size;
1325
1326 DEBUG(5,("release_posix_lock_posix_flavour: Real unlock: offset = %.0f, count = %.0f\n",
1327 (double)offset, (double)count ));
1328
1329 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_UNLCK)) {
1330 ret = False;
1331 }
1332 }
1333
1334 talloc_destroy(ul_ctx);
1335 return ret;
1336 }
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