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[Samba.git] / source / locking / brlock.c
blob38f96e78a74b6dcf179fa8cb64b73ebf23416689
1 /*
2 Unix SMB/CIFS implementation.
3 byte range locking code
4 Updated to handle range splits/merges.
5
6 Copyright (C) Andrew Tridgell 1992-2000
7 Copyright (C) Jeremy Allison 1992-2000
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23
24 /* This module implements a tdb based byte range locking service,
25 replacing the fcntl() based byte range locking previously
26 used. This allows us to provide the same semantics as NT */
27
28 #include "includes.h"
29
30 #undef DBGC_CLASS
31 #define DBGC_CLASS DBGC_LOCKING
32
33 #define ZERO_ZERO 0
34
35 /* The open brlock.tdb database. */
36
37 static TDB_CONTEXT *tdb;
38
39 /****************************************************************************
40 Debug info at level 10 for lock struct.
41 ****************************************************************************/
42
43 static void print_lock_struct(unsigned int i, struct lock_struct *pls)
44 {
45 DEBUG(10,("[%u]: smbpid = %u, tid = %u, pid = %u, ",
46 i,
47 (unsigned int)pls->context.smbpid,
48 (unsigned int)pls->context.tid,
49 (unsigned int)procid_to_pid(&pls->context.pid) ));
50
51 DEBUG(10,("start = %.0f, size = %.0f, fnum = %d, %s %s\n",
52 (double)pls->start,
53 (double)pls->size,
54 pls->fnum,
55 lock_type_name(pls->lock_type),
56 lock_flav_name(pls->lock_flav) ));
57 }
58
59 /****************************************************************************
60 See if two locking contexts are equal.
61 ****************************************************************************/
62
63 BOOL brl_same_context(const struct lock_context *ctx1,
64 const struct lock_context *ctx2)
65 {
66 return (procid_equal(&ctx1->pid, &ctx2->pid) &&
67 (ctx1->smbpid == ctx2->smbpid) &&
68 (ctx1->tid == ctx2->tid));
69 }
70
71 /****************************************************************************
72 See if lck1 and lck2 overlap.
73 ****************************************************************************/
74
75 static BOOL brl_overlap(const struct lock_struct *lck1,
76 const struct lock_struct *lck2)
77 {
78 /* this extra check is not redundent - it copes with locks
79 that go beyond the end of 64 bit file space */
80 if (lck1->size != 0 &&
81 lck1->start == lck2->start &&
82 lck1->size == lck2->size) {
83 return True;
84 }
85
86 if (lck1->start >= (lck2->start+lck2->size) ||
87 lck2->start >= (lck1->start+lck1->size)) {
88 return False;
89 }
90 return True;
91 }
92
93 /****************************************************************************
94 See if lock2 can be added when lock1 is in place.
95 ****************************************************************************/
96
97 static BOOL brl_conflict(const struct lock_struct *lck1,
98 const struct lock_struct *lck2)
99 {
100 /* Ignore PENDING locks. */
101 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
102 return False;
103
104 /* Read locks never conflict. */
105 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
106 return False;
107 }
108
109 if (brl_same_context(&lck1->context, &lck2->context) &&
110 lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
111 return False;
112 }
113
114 return brl_overlap(lck1, lck2);
115 }
116
117 /****************************************************************************
118 See if lock2 can be added when lock1 is in place - when both locks are POSIX
119 flavour. POSIX locks ignore fnum - they only care about dev/ino which we
120 know already match.
121 ****************************************************************************/
122
123 static BOOL brl_conflict_posix(const struct lock_struct *lck1,
124 const struct lock_struct *lck2)
125 {
126 #if defined(DEVELOPER)
127 SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
128 SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
129 #endif
130
131 /* Ignore PENDING locks. */
132 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
133 return False;
134
135 /* Read locks never conflict. */
136 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
137 return False;
138 }
139
140 /* Locks on the same context con't conflict. Ignore fnum. */
141 if (brl_same_context(&lck1->context, &lck2->context)) {
142 return False;
143 }
144
145 /* One is read, the other write, or the context is different,
146 do they overlap ? */
147 return brl_overlap(lck1, lck2);
148 }
149
150 #if ZERO_ZERO
151 static BOOL brl_conflict1(const struct lock_struct *lck1,
152 const struct lock_struct *lck2)
153 {
154 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
155 return False;
156
157 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
158 return False;
159 }
160
161 if (brl_same_context(&lck1->context, &lck2->context) &&
162 lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
163 return False;
164 }
165
166 if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
167 return True;
168 }
169
170 if (lck1->start >= (lck2->start + lck2->size) ||
171 lck2->start >= (lck1->start + lck1->size)) {
172 return False;
173 }
174
175 return True;
176 }
177 #endif
178
179 /****************************************************************************
180 Check to see if this lock conflicts, but ignore our own locks on the
181 same fnum only. This is the read/write lock check code path.
182 This is never used in the POSIX lock case.
183 ****************************************************************************/
184
185 static BOOL brl_conflict_other(const struct lock_struct *lck1, const struct lock_struct *lck2)
186 {
187 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
188 return False;
189
190 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
191 return False;
192
193 /* POSIX flavour locks never conflict here - this is only called
194 in the read/write path. */
195
196 if (lck1->lock_flav == POSIX_LOCK && lck2->lock_flav == POSIX_LOCK)
197 return False;
198
199 /*
200 * Incoming WRITE locks conflict with existing READ locks even
201 * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
202 */
203
204 if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
205 if (brl_same_context(&lck1->context, &lck2->context) &&
206 lck1->fnum == lck2->fnum)
207 return False;
208 }
209
210 return brl_overlap(lck1, lck2);
211 }
212
213 /****************************************************************************
214 Check if an unlock overlaps a pending lock.
215 ****************************************************************************/
216
217 static BOOL brl_pending_overlap(const struct lock_struct *lock, const struct lock_struct *pend_lock)
218 {
219 if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
220 return True;
221 if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
222 return True;
223 return False;
224 }
225
226 /****************************************************************************
227 Amazingly enough, w2k3 "remembers" whether the last lock failure on a fnum
228 is the same as this one and changes its error code. I wonder if any
229 app depends on this ?
230 ****************************************************************************/
231
232 static NTSTATUS brl_lock_failed(files_struct *fsp, const struct lock_struct *lock, BOOL blocking_lock)
233 {
234 if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
235 /* amazing the little things you learn with a test
236 suite. Locks beyond this offset (as a 64 bit
237 number!) always generate the conflict error code,
238 unless the top bit is set */
239 if (!blocking_lock) {
240 fsp->last_lock_failure = *lock;
241 }
242 return NT_STATUS_FILE_LOCK_CONFLICT;
243 }
244
245 if (procid_equal(&lock->context.pid, &fsp->last_lock_failure.context.pid) &&
246 lock->context.tid == fsp->last_lock_failure.context.tid &&
247 lock->fnum == fsp->last_lock_failure.fnum &&
248 lock->start == fsp->last_lock_failure.start) {
249 return NT_STATUS_FILE_LOCK_CONFLICT;
250 }
251
252 if (!blocking_lock) {
253 fsp->last_lock_failure = *lock;
254 }
255 return NT_STATUS_LOCK_NOT_GRANTED;
256 }
257
258 /****************************************************************************
259 Open up the brlock.tdb database.
260 ****************************************************************************/
261
262 void brl_init(int read_only)
263 {
264 if (tdb) {
265 return;
266 }
267 tdb = tdb_open_log(lock_path("brlock.tdb"),
268 lp_open_files_db_hash_size(),
269 TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST),
270 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644 );
271 if (!tdb) {
272 DEBUG(0,("Failed to open byte range locking database %s\n",
273 lock_path("brlock.tdb")));
274 return;
275 }
276
277 /* Activate the per-hashchain freelist */
278 tdb_set_max_dead(tdb, 5);
279 }
280
281 /****************************************************************************
282 Close down the brlock.tdb database.
283 ****************************************************************************/
284
285 void brl_shutdown(int read_only)
286 {
287 if (!tdb) {
288 return;
289 }
290 tdb_close(tdb);
291 }
292
293 #if ZERO_ZERO
294 /****************************************************************************
295 Compare two locks for sorting.
296 ****************************************************************************/
297
298 static int lock_compare(const struct lock_struct *lck1,
299 const struct lock_struct *lck2)
300 {
301 if (lck1->start != lck2->start) {
302 return (lck1->start - lck2->start);
303 }
304 if (lck2->size != lck1->size) {
305 return ((int)lck1->size - (int)lck2->size);
306 }
307 return 0;
308 }
309 #endif
310
311 /****************************************************************************
312 Lock a range of bytes - Windows lock semantics.
313 ****************************************************************************/
314
315 static NTSTATUS brl_lock_windows(struct byte_range_lock *br_lck,
316 struct lock_struct *plock, BOOL blocking_lock)
317 {
318 unsigned int i;
319 files_struct *fsp = br_lck->fsp;
320 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
321
322 for (i=0; i < br_lck->num_locks; i++) {
323 /* Do any Windows or POSIX locks conflict ? */
324 if (brl_conflict(&locks[i], plock)) {
325 /* Remember who blocked us. */
326 plock->context.smbpid = locks[i].context.smbpid;
327 return brl_lock_failed(fsp,plock,blocking_lock);
328 }
329 #if ZERO_ZERO
330 if (plock->start == 0 && plock->size == 0 &&
331 locks[i].size == 0) {
332 break;
333 }
334 #endif
335 }
336
337 /* We can get the Windows lock, now see if it needs to
338 be mapped into a lower level POSIX one, and if so can
339 we get it ? */
340
341 if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(fsp->conn->params)) {
342 int errno_ret;
343 if (!set_posix_lock_windows_flavour(fsp,
344 plock->start,
345 plock->size,
346 plock->lock_type,
347 &plock->context,
348 locks,
349 br_lck->num_locks,
350 &errno_ret)) {
351
352 /* We don't know who blocked us. */
353 plock->context.smbpid = 0xFFFFFFFF;
354
355 if (errno_ret == EACCES || errno_ret == EAGAIN) {
356 return NT_STATUS_FILE_LOCK_CONFLICT;
357 } else {
358 return map_nt_error_from_unix(errno);
359 }
360 }
361 }
362
363 /* no conflicts - add it to the list of locks */
364 locks = (struct lock_struct *)SMB_REALLOC(locks, (br_lck->num_locks + 1) * sizeof(*locks));
365 if (!locks) {
366 return NT_STATUS_NO_MEMORY;
367 }
368
369 memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
370 br_lck->num_locks += 1;
371 br_lck->lock_data = (void *)locks;
372 br_lck->modified = True;
373
374 return NT_STATUS_OK;
375 }
376
377 /****************************************************************************
378 Cope with POSIX range splits and merges.
379 ****************************************************************************/
380
381 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr, /* Output array. */
382 const struct lock_struct *ex, /* existing lock. */
383 const struct lock_struct *plock, /* proposed lock. */
384 BOOL *lock_was_added)
385 {
386 BOOL lock_types_differ = (ex->lock_type != plock->lock_type);
387
388 /* We can't merge non-conflicting locks on different context - ignore fnum. */
389
390 if (!brl_same_context(&ex->context, &plock->context)) {
391 /* Just copy. */
392 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
393 return 1;
394 }
395
396 /* We now know we have the same context. */
397
398 /* Did we overlap ? */
399
400 /*********************************************
401 +---------+
402 | ex |
403 +---------+
404 +-------+
405 | plock |
406 +-------+
407 OR....
408 +---------+
409 | ex |
410 +---------+
411 **********************************************/
412
413 if ( (ex->start > (plock->start + plock->size)) ||
414 (plock->start > (ex->start + ex->size))) {
415 /* No overlap with this lock - copy existing. */
416 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
417 return 1;
418 }
419
420 /*********************************************
421 +---------------------------+
422 | ex |
423 +---------------------------+
424 +---------------------------+
425 | plock | -> replace with plock.
426 +---------------------------+
427 **********************************************/
428
429 if ( (ex->start >= plock->start) &&
430 (ex->start + ex->size <= plock->start + plock->size) ) {
431 memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
432 *lock_was_added = True;
433 return 1;
434 }
435
436 /*********************************************
437 +-----------------------+
438 | ex |
439 +-----------------------+
440 +---------------+
441 | plock |
442 +---------------+
443 OR....
444 +-------+
445 | ex |
446 +-------+
447 +---------------+
448 | plock |
449 +---------------+
450
451 BECOMES....
452 +---------------+-------+
453 | plock | ex | - different lock types.
454 +---------------+-------+
455 OR.... (merge)
456 +-----------------------+
457 | ex | - same lock type.
458 +-----------------------+
459 **********************************************/
460
461 if ( (ex->start >= plock->start) &&
462 (ex->start <= plock->start + plock->size) &&
463 (ex->start + ex->size > plock->start + plock->size) ) {
464
465 *lock_was_added = True;
466
467 /* If the lock types are the same, we merge, if different, we
468 add the new lock before the old. */
469
470 if (lock_types_differ) {
471 /* Add new. */
472 memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
473 memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
474 /* Adjust existing start and size. */
475 lck_arr[1].start = plock->start + plock->size;
476 lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
477 return 2;
478 } else {
479 /* Merge. */
480 memcpy(&lck_arr[0], plock, sizeof(struct lock_struct));
481 /* Set new start and size. */
482 lck_arr[0].start = plock->start;
483 lck_arr[0].size = (ex->start + ex->size) - plock->start;
484 return 1;
485 }
486 }
487
488 /*********************************************
489 +-----------------------+
490 | ex |
491 +-----------------------+
492 +---------------+
493 | plock |
494 +---------------+
495 OR....
496 +-------+
497 | ex |
498 +-------+
499 +---------------+
500 | plock |
501 +---------------+
502 BECOMES....
503 +-------+---------------+
504 | ex | plock | - different lock types
505 +-------+---------------+
506
507 OR.... (merge)
508 +-----------------------+
509 | ex | - same lock type.
510 +-----------------------+
511
512 **********************************************/
513
514 if ( (ex->start < plock->start) &&
515 (ex->start + ex->size >= plock->start) &&
516 (ex->start + ex->size <= plock->start + plock->size) ) {
517
518 *lock_was_added = True;
519
520 /* If the lock types are the same, we merge, if different, we
521 add the new lock after the old. */
522
523 if (lock_types_differ) {
524 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
525 memcpy(&lck_arr[1], plock, sizeof(struct lock_struct));
526 /* Adjust existing size. */
527 lck_arr[0].size = plock->start - ex->start;
528 return 2;
529 } else {
530 /* Merge. */
531 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
532 /* Adjust existing size. */
533 lck_arr[0].size = (plock->start + plock->size) - ex->start;
534 return 1;
535 }
536 }
537
538 /*********************************************
539 +---------------------------+
540 | ex |
541 +---------------------------+
542 +---------+
543 | plock |
544 +---------+
545 BECOMES.....
546 +-------+---------+---------+
547 | ex | plock | ex | - different lock types.
548 +-------+---------+---------+
549 OR
550 +---------------------------+
551 | ex | - same lock type.
552 +---------------------------+
553 **********************************************/
554
555 if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
556 *lock_was_added = True;
557
558 if (lock_types_differ) {
559
560 /* We have to split ex into two locks here. */
561
562 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
563 memcpy(&lck_arr[1], plock, sizeof(struct lock_struct));
564 memcpy(&lck_arr[2], ex, sizeof(struct lock_struct));
565
566 /* Adjust first existing size. */
567 lck_arr[0].size = plock->start - ex->start;
568
569 /* Adjust second existing start and size. */
570 lck_arr[2].start = plock->start + plock->size;
571 lck_arr[2].size = (ex->start + ex->size) - (plock->start + plock->size);
572 return 3;
573 } else {
574 /* Just eat plock. */
575 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
576 return 1;
577 }
578 }
579
580 /* Never get here. */
581 smb_panic("brlock_posix_split_merge\n");
582 /* Notreached. */
583 abort();
584 /* Keep some compilers happy. */
585 return 0;
586 }
587
588 /****************************************************************************
589 Lock a range of bytes - POSIX lock semantics.
590 We must cope with range splits and merges.
591 ****************************************************************************/
592
593 static NTSTATUS brl_lock_posix(struct byte_range_lock *br_lck,
594 struct lock_struct *plock)
595 {
596 unsigned int i, count;
597 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
598 struct lock_struct *tp;
599 BOOL lock_was_added = False;
600 BOOL signal_pending_read = False;
601
602 /* No zero-zero locks for POSIX. */
603 if (plock->start == 0 && plock->size == 0) {
604 return NT_STATUS_INVALID_PARAMETER;
605 }
606
607 /* Don't allow 64-bit lock wrap. */
608 if (plock->start + plock->size < plock->start ||
609 plock->start + plock->size < plock->size) {
610 return NT_STATUS_INVALID_PARAMETER;
611 }
612
613 /* The worst case scenario here is we have to split an
614 existing POSIX lock range into two, and add our lock,
615 so we need at most 2 more entries. */
616
617 tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 2));
618 if (!tp) {
619 return NT_STATUS_NO_MEMORY;
620 }
621
622 count = 0;
623 for (i=0; i < br_lck->num_locks; i++) {
624 struct lock_struct *curr_lock = &locks[i];
625
626 /* If we have a pending read lock, a lock downgrade should
627 trigger a lock re-evaluation. */
628 if (curr_lock->lock_type == PENDING_READ_LOCK &&
629 brl_pending_overlap(plock, curr_lock)) {
630 signal_pending_read = True;
631 }
632
633 if (curr_lock->lock_flav == WINDOWS_LOCK) {
634 /* Do any Windows flavour locks conflict ? */
635 if (brl_conflict(curr_lock, plock)) {
636 /* No games with error messages. */
637 SAFE_FREE(tp);
638 /* Remember who blocked us. */
639 plock->context.smbpid = curr_lock->context.smbpid;
640 return NT_STATUS_FILE_LOCK_CONFLICT;
641 }
642 /* Just copy the Windows lock into the new array. */
643 memcpy(&tp[count], curr_lock, sizeof(struct lock_struct));
644 count++;
645 } else {
646 /* POSIX conflict semantics are different. */
647 if (brl_conflict_posix(curr_lock, plock)) {
648 /* Can't block ourselves with POSIX locks. */
649 /* No games with error messages. */
650 SAFE_FREE(tp);
651 /* Remember who blocked us. */
652 plock->context.smbpid = curr_lock->context.smbpid;
653 return NT_STATUS_FILE_LOCK_CONFLICT;
654 }
655
656 /* Work out overlaps. */
657 count += brlock_posix_split_merge(&tp[count], curr_lock, plock, &lock_was_added);
658 }
659 }
660
661 if (!lock_was_added) {
662 memcpy(&tp[count], plock, sizeof(struct lock_struct));
663 count++;
664 }
665
666 /* We can get the POSIX lock, now see if it needs to
667 be mapped into a lower level POSIX one, and if so can
668 we get it ? */
669
670 if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(br_lck->fsp->conn->params)) {
671 int errno_ret;
672
673 /* The lower layer just needs to attempt to
674 get the system POSIX lock. We've weeded out
675 any conflicts above. */
676
677 if (!set_posix_lock_posix_flavour(br_lck->fsp,
678 plock->start,
679 plock->size,
680 plock->lock_type,
681 &errno_ret)) {
682
683 /* We don't know who blocked us. */
684 plock->context.smbpid = 0xFFFFFFFF;
685
686 if (errno_ret == EACCES || errno_ret == EAGAIN) {
687 SAFE_FREE(tp);
688 return NT_STATUS_FILE_LOCK_CONFLICT;
689 } else {
690 SAFE_FREE(tp);
691 return map_nt_error_from_unix(errno);
692 }
693 }
694 }
695
696 /* Realloc so we don't leak entries per lock call. */
697 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
698 if (!tp) {
699 return NT_STATUS_NO_MEMORY;
700 }
701 br_lck->num_locks = count;
702 SAFE_FREE(br_lck->lock_data);
703 br_lck->lock_data = (void *)tp;
704 locks = tp;
705 br_lck->modified = True;
706
707 /* A successful downgrade from write to read lock can trigger a lock
708 re-evalutation where waiting readers can now proceed. */
709
710 if (signal_pending_read) {
711 /* Send unlock messages to any pending read waiters that overlap. */
712 for (i=0; i < br_lck->num_locks; i++) {
713 struct lock_struct *pend_lock = &locks[i];
714
715 /* Ignore non-pending locks. */
716 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
717 continue;
718 }
719
720 if (pend_lock->lock_type == PENDING_READ_LOCK &&
721 brl_pending_overlap(plock, pend_lock)) {
722 DEBUG(10,("brl_lock_posix: sending unlock message to pid %s\n",
723 procid_str_static(&pend_lock->context.pid )));
724
725 message_send_pid(pend_lock->context.pid,
726 MSG_SMB_UNLOCK,
727 NULL, 0, True);
728 }
729 }
730 }
731
732 return NT_STATUS_OK;
733 }
734
735 /****************************************************************************
736 Lock a range of bytes.
737 ****************************************************************************/
738
739 NTSTATUS brl_lock(struct byte_range_lock *br_lck,
740 uint32 smbpid,
741 struct process_id pid,
742 br_off start,
743 br_off size,
744 enum brl_type lock_type,
745 enum brl_flavour lock_flav,
746 BOOL blocking_lock,
747 uint32 *psmbpid)
748 {
749 NTSTATUS ret;
750 struct lock_struct lock;
751
752 #if !ZERO_ZERO
753 if (start == 0 && size == 0) {
754 DEBUG(0,("client sent 0/0 lock - please report this\n"));
755 }
756 #endif
757
758 lock.context.smbpid = smbpid;
759 lock.context.pid = pid;
760 lock.context.tid = br_lck->fsp->conn->cnum;
761 lock.start = start;
762 lock.size = size;
763 lock.fnum = br_lck->fsp->fnum;
764 lock.lock_type = lock_type;
765 lock.lock_flav = lock_flav;
766
767 if (lock_flav == WINDOWS_LOCK) {
768 ret = brl_lock_windows(br_lck, &lock, blocking_lock);
769 } else {
770 ret = brl_lock_posix(br_lck, &lock);
771 }
772
773 #if ZERO_ZERO
774 /* sort the lock list */
775 qsort(br_lck->lock_data, (size_t)br_lck->num_locks, sizeof(lock), lock_compare);
776 #endif
777
778 /* If we're returning an error, return who blocked us. */
779 if (!NT_STATUS_IS_OK(ret) && psmbpid) {
780 *psmbpid = lock.context.smbpid;
781 }
782 return ret;
783 }
784
785 /****************************************************************************
786 Unlock a range of bytes - Windows semantics.
787 ****************************************************************************/
788
789 static BOOL brl_unlock_windows(struct byte_range_lock *br_lck, const struct lock_struct *plock)
790 {
791 unsigned int i, j;
792 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
793 enum brl_type deleted_lock_type = READ_LOCK; /* shut the compiler up.... */
794
795 #if ZERO_ZERO
796 /* Delete write locks by preference... The lock list
797 is sorted in the zero zero case. */
798
799 for (i = 0; i < br_lck->num_locks; i++) {
800 struct lock_struct *lock = &locks[i];
801
802 if (lock->lock_type == WRITE_LOCK &&
803 brl_same_context(&lock->context, &plock->context) &&
804 lock->fnum == plock->fnum &&
805 lock->lock_flav == WINDOWS_LOCK &&
806 lock->start == plock->start &&
807 lock->size == plock->size) {
808
809 /* found it - delete it */
810 deleted_lock_type = lock->lock_type;
811 break;
812 }
813 }
814
815 if (i != br_lck->num_locks) {
816 /* We found it - don't search again. */
817 goto unlock_continue;
818 }
819 #endif
820
821 for (i = 0; i < br_lck->num_locks; i++) {
822 struct lock_struct *lock = &locks[i];
823
824 /* Only remove our own locks that match in start, size, and flavour. */
825 if (brl_same_context(&lock->context, &plock->context) &&
826 lock->fnum == plock->fnum &&
827 lock->lock_flav == WINDOWS_LOCK &&
828 lock->start == plock->start &&
829 lock->size == plock->size ) {
830 deleted_lock_type = lock->lock_type;
831 break;
832 }
833 }
834
835 if (i == br_lck->num_locks) {
836 /* we didn't find it */
837 return False;
838 }
839
840 #if ZERO_ZERO
841 unlock_continue:
842 #endif
843
844 /* Actually delete the lock. */
845 if (i < br_lck->num_locks - 1) {
846 memmove(&locks[i], &locks[i+1],
847 sizeof(*locks)*((br_lck->num_locks-1) - i));
848 }
849
850 br_lck->num_locks -= 1;
851 br_lck->modified = True;
852
853 /* Unlock the underlying POSIX regions. */
854 if(lp_posix_locking(br_lck->fsp->conn->params)) {
855 release_posix_lock_windows_flavour(br_lck->fsp,
856 plock->start,
857 plock->size,
858 deleted_lock_type,
859 &plock->context,
860 locks,
861 br_lck->num_locks);
862 }
863
864 /* Send unlock messages to any pending waiters that overlap. */
865 for (j=0; j < br_lck->num_locks; j++) {
866 struct lock_struct *pend_lock = &locks[j];
867
868 /* Ignore non-pending locks. */
869 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
870 continue;
871 }
872
873 /* We could send specific lock info here... */
874 if (brl_pending_overlap(plock, pend_lock)) {
875 DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
876 procid_str_static(&pend_lock->context.pid )));
877
878 message_send_pid(pend_lock->context.pid,
879 MSG_SMB_UNLOCK,
880 NULL, 0, True);
881 }
882 }
883
884 return True;
885 }
886
887 /****************************************************************************
888 Unlock a range of bytes - POSIX semantics.
889 ****************************************************************************/
890
891 static BOOL brl_unlock_posix(struct byte_range_lock *br_lck, const struct lock_struct *plock)
892 {
893 unsigned int i, j, count;
894 struct lock_struct *tp;
895 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
896 BOOL overlap_found = False;
897
898 /* No zero-zero locks for POSIX. */
899 if (plock->start == 0 && plock->size == 0) {
900 return False;
901 }
902
903 /* Don't allow 64-bit lock wrap. */
904 if (plock->start + plock->size < plock->start ||
905 plock->start + plock->size < plock->size) {
906 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
907 return False;
908 }
909
910 /* The worst case scenario here is we have to split an
911 existing POSIX lock range into two, so we need at most
912 1 more entry. */
913
914 tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 1));
915 if (!tp) {
916 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
917 return False;
918 }
919
920 count = 0;
921 for (i = 0; i < br_lck->num_locks; i++) {
922 struct lock_struct *lock = &locks[i];
923 struct lock_struct tmp_lock[3];
924 BOOL lock_was_added = False;
925 unsigned int tmp_count;
926
927 /* Only remove our own locks - ignore fnum. */
928 if (IS_PENDING_LOCK(lock->lock_type) ||
929 !brl_same_context(&lock->context, &plock->context)) {
930 memcpy(&tp[count], lock, sizeof(struct lock_struct));
931 count++;
932 continue;
933 }
934
935 /* Work out overlaps. */
936 tmp_count = brlock_posix_split_merge(&tmp_lock[0], &locks[i], plock, &lock_was_added);
937
938 if (tmp_count == 1) {
939 /* Ether the locks didn't overlap, or the unlock completely
940 overlapped this lock. If it didn't overlap, then there's
941 no change in the locks. */
942 if (tmp_lock[0].lock_type != UNLOCK_LOCK) {
943 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
944 /* No change in this lock. */
945 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
946 count++;
947 } else {
948 SMB_ASSERT(tmp_lock[0].lock_type == UNLOCK_LOCK);
949 overlap_found = True;
950 }
951 continue;
952 } else if (tmp_count == 2) {
953 /* The unlock overlapped an existing lock. Copy the truncated
954 lock into the lock array. */
955 if (tmp_lock[0].lock_type != UNLOCK_LOCK) {
956 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
957 SMB_ASSERT(tmp_lock[1].lock_type == UNLOCK_LOCK);
958 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
959 if (tmp_lock[0].size != locks[i].size) {
960 overlap_found = True;
961 }
962 } else {
963 SMB_ASSERT(tmp_lock[0].lock_type == UNLOCK_LOCK);
964 SMB_ASSERT(tmp_lock[1].lock_type == locks[i].lock_type);
965 memcpy(&tp[count], &tmp_lock[1], sizeof(struct lock_struct));
966 if (tmp_lock[1].start != locks[i].start) {
967 overlap_found = True;
968 }
969 }
970 count++;
971 continue;
972 } else {
973 /* tmp_count == 3 - (we split a lock range in two). */
974 SMB_ASSERT(tmp_lock[0].lock_type == locks[i].lock_type);
975 SMB_ASSERT(tmp_lock[1].lock_type == UNLOCK_LOCK);
976 SMB_ASSERT(tmp_lock[2].lock_type == locks[i].lock_type);
977
978 memcpy(&tp[count], &tmp_lock[0], sizeof(struct lock_struct));
979 count++;
980 memcpy(&tp[count], &tmp_lock[2], sizeof(struct lock_struct));
981 count++;
982 overlap_found = True;
983 /* Optimisation... */
984 /* We know we're finished here as we can't overlap any
985 more POSIX locks. Copy the rest of the lock array. */
986 if (i < br_lck->num_locks - 1) {
987 memcpy(&tp[count], &locks[i+1],
988 sizeof(*locks)*((br_lck->num_locks-1) - i));
989 count += ((br_lck->num_locks-1) - i);
990 }
991 break;
992 }
993 }
994
995 if (!overlap_found) {
996 /* Just ignore - no change. */
997 SAFE_FREE(tp);
998 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
999 return True;
1000 }
1001
1002 /* Unlock any POSIX regions. */
1003 if(lp_posix_locking(br_lck->fsp->conn->params)) {
1004 release_posix_lock_posix_flavour(br_lck->fsp,
1005 plock->start,
1006 plock->size,
1007 &plock->context,
1008 tp,
1009 count);
1010 }
1011
1012 /* Realloc so we don't leak entries per unlock call. */
1013 if (count) {
1014 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
1015 if (!tp) {
1016 DEBUG(10,("brl_unlock_posix: realloc fail\n"));
1017 return False;
1018 }
1019 } else {
1020 /* We deleted the last lock. */
1021 SAFE_FREE(tp);
1022 tp = NULL;
1023 }
1024
1025 br_lck->num_locks = count;
1026 SAFE_FREE(br_lck->lock_data);
1027 locks = tp;
1028 br_lck->lock_data = (void *)tp;
1029 br_lck->modified = True;
1030
1031 /* Send unlock messages to any pending waiters that overlap. */
1032
1033 for (j=0; j < br_lck->num_locks; j++) {
1034 struct lock_struct *pend_lock = &locks[j];
1035
1036 /* Ignore non-pending locks. */
1037 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1038 continue;
1039 }
1040
1041 /* We could send specific lock info here... */
1042 if (brl_pending_overlap(plock, pend_lock)) {
1043 DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1044 procid_str_static(&pend_lock->context.pid )));
1045
1046 message_send_pid(pend_lock->context.pid,
1047 MSG_SMB_UNLOCK,
1048 NULL, 0, True);
1049 }
1050 }
1051
1052 return True;
1053 }
1054
1055 /****************************************************************************
1056 Unlock a range of bytes.
1057 ****************************************************************************/
1058
1059 BOOL brl_unlock(struct byte_range_lock *br_lck,
1060 uint32 smbpid,
1061 struct process_id pid,
1062 br_off start,
1063 br_off size,
1064 enum brl_flavour lock_flav)
1065 {
1066 struct lock_struct lock;
1067
1068 lock.context.smbpid = smbpid;
1069 lock.context.pid = pid;
1070 lock.context.tid = br_lck->fsp->conn->cnum;
1071 lock.start = start;
1072 lock.size = size;
1073 lock.fnum = br_lck->fsp->fnum;
1074 lock.lock_type = UNLOCK_LOCK;
1075 lock.lock_flav = lock_flav;
1076
1077 if (lock_flav == WINDOWS_LOCK) {
1078 return brl_unlock_windows(br_lck, &lock);
1079 } else {
1080 return brl_unlock_posix(br_lck, &lock);
1081 }
1082 }
1083
1084 /****************************************************************************
1085 Test if we could add a lock if we wanted to.
1086 Returns True if the region required is currently unlocked, False if locked.
1087 ****************************************************************************/
1088
1089 BOOL brl_locktest(struct byte_range_lock *br_lck,
1090 uint32 smbpid,
1091 struct process_id pid,
1092 br_off start,
1093 br_off size,
1094 enum brl_type lock_type,
1095 enum brl_flavour lock_flav)
1096 {
1097 BOOL ret = True;
1098 unsigned int i;
1099 struct lock_struct lock;
1100 const struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1101 files_struct *fsp = br_lck->fsp;
1102
1103 lock.context.smbpid = smbpid;
1104 lock.context.pid = pid;
1105 lock.context.tid = br_lck->fsp->conn->cnum;
1106 lock.start = start;
1107 lock.size = size;
1108 lock.fnum = fsp->fnum;
1109 lock.lock_type = lock_type;
1110 lock.lock_flav = lock_flav;
1111
1112 /* Make sure existing locks don't conflict */
1113 for (i=0; i < br_lck->num_locks; i++) {
1114 /*
1115 * Our own locks don't conflict.
1116 */
1117 if (brl_conflict_other(&locks[i], &lock)) {
1118 return False;
1119 }
1120 }
1121
1122 /*
1123 * There is no lock held by an SMB daemon, check to
1124 * see if there is a POSIX lock from a UNIX or NFS process.
1125 * This only conflicts with Windows locks, not POSIX locks.
1126 */
1127
1128 if(lp_posix_locking(fsp->conn->params) && (lock_flav == WINDOWS_LOCK)) {
1129 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1130
1131 DEBUG(10,("brl_locktest: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1132 (double)start, (double)size, ret ? "locked" : "unlocked",
1133 fsp->fnum, fsp->fsp_name ));
1134
1135 /* We need to return the inverse of is_posix_locked. */
1136 ret = !ret;
1137 }
1138
1139 /* no conflicts - we could have added it */
1140 return ret;
1141 }
1142
1143 /****************************************************************************
1144 Query for existing locks.
1145 ****************************************************************************/
1146
1147 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1148 uint32 *psmbpid,
1149 struct process_id pid,
1150 br_off *pstart,
1151 br_off *psize,
1152 enum brl_type *plock_type,
1153 enum brl_flavour lock_flav)
1154 {
1155 unsigned int i;
1156 struct lock_struct lock;
1157 const struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1158 files_struct *fsp = br_lck->fsp;
1159
1160 lock.context.smbpid = *psmbpid;
1161 lock.context.pid = pid;
1162 lock.context.tid = br_lck->fsp->conn->cnum;
1163 lock.start = *pstart;
1164 lock.size = *psize;
1165 lock.fnum = fsp->fnum;
1166 lock.lock_type = *plock_type;
1167 lock.lock_flav = lock_flav;
1168
1169 /* Make sure existing locks don't conflict */
1170 for (i=0; i < br_lck->num_locks; i++) {
1171 const struct lock_struct *exlock = &locks[i];
1172 BOOL conflict = False;
1173
1174 if (exlock->lock_flav == WINDOWS_LOCK) {
1175 conflict = brl_conflict(exlock, &lock);
1176 } else {
1177 conflict = brl_conflict_posix(exlock, &lock);
1178 }
1179
1180 if (conflict) {
1181 *psmbpid = exlock->context.smbpid;
1182 *pstart = exlock->start;
1183 *psize = exlock->size;
1184 *plock_type = exlock->lock_type;
1185 return NT_STATUS_LOCK_NOT_GRANTED;
1186 }
1187 }
1188
1189 /*
1190 * There is no lock held by an SMB daemon, check to
1191 * see if there is a POSIX lock from a UNIX or NFS process.
1192 */
1193
1194 if(lp_posix_locking(fsp->conn->params)) {
1195 BOOL ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1196
1197 DEBUG(10,("brl_lockquery: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1198 (double)*pstart, (double)*psize, ret ? "locked" : "unlocked",
1199 fsp->fnum, fsp->fsp_name ));
1200
1201 if (ret) {
1202 /* Hmmm. No clue what to set smbpid to - use -1. */
1203 *psmbpid = 0xFFFF;
1204 return NT_STATUS_LOCK_NOT_GRANTED;
1205 }
1206 }
1207
1208 return NT_STATUS_OK;
1209 }
1210
1211 /****************************************************************************
1212 Remove a particular pending lock.
1213 ****************************************************************************/
1214
1215 BOOL brl_lock_cancel(struct byte_range_lock *br_lck,
1216 uint32 smbpid,
1217 struct process_id pid,
1218 br_off start,
1219 br_off size,
1220 enum brl_flavour lock_flav)
1221 {
1222 unsigned int i;
1223 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1224 struct lock_context context;
1225
1226 context.smbpid = smbpid;
1227 context.pid = pid;
1228 context.tid = br_lck->fsp->conn->cnum;
1229
1230 for (i = 0; i < br_lck->num_locks; i++) {
1231 struct lock_struct *lock = &locks[i];
1232
1233 /* For pending locks we *always* care about the fnum. */
1234 if (brl_same_context(&lock->context, &context) &&
1235 lock->fnum == br_lck->fsp->fnum &&
1236 IS_PENDING_LOCK(lock->lock_type) &&
1237 lock->lock_flav == lock_flav &&
1238 lock->start == start &&
1239 lock->size == size) {
1240 break;
1241 }
1242 }
1243
1244 if (i == br_lck->num_locks) {
1245 /* Didn't find it. */
1246 return False;
1247 }
1248
1249 if (i < br_lck->num_locks - 1) {
1250 /* Found this particular pending lock - delete it */
1251 memmove(&locks[i], &locks[i+1],
1252 sizeof(*locks)*((br_lck->num_locks-1) - i));
1253 }
1254
1255 br_lck->num_locks -= 1;
1256 br_lck->modified = True;
1257 return True;
1258 }
1259
1260 /****************************************************************************
1261 Remove any locks associated with a open file.
1262 We return True if this process owns any other Windows locks on this
1263 fd and so we should not immediately close the fd.
1264 ****************************************************************************/
1265
1266 void brl_close_fnum(struct byte_range_lock *br_lck)
1267 {
1268 files_struct *fsp = br_lck->fsp;
1269 uint16 tid = fsp->conn->cnum;
1270 int fnum = fsp->fnum;
1271 unsigned int i, j, dcount=0;
1272 int num_deleted_windows_locks = 0;
1273 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1274 struct process_id pid = procid_self();
1275 BOOL unlock_individually = False;
1276
1277 if(lp_posix_locking(fsp->conn->params)) {
1278
1279 /* Check if there are any Windows locks associated with this dev/ino
1280 pair that are not this fnum. If so we need to call unlock on each
1281 one in order to release the system POSIX locks correctly. */
1282
1283 for (i=0; i < br_lck->num_locks; i++) {
1284 struct lock_struct *lock = &locks[i];
1285
1286 if (!procid_equal(&lock->context.pid, &pid)) {
1287 continue;
1288 }
1289
1290 if (lock->lock_type != READ_LOCK && lock->lock_type != WRITE_LOCK) {
1291 continue; /* Ignore pending. */
1292 }
1293
1294 if (lock->context.tid != tid || lock->fnum != fnum) {
1295 unlock_individually = True;
1296 break;
1297 }
1298 }
1299
1300 if (unlock_individually) {
1301 struct lock_struct *locks_copy;
1302 unsigned int num_locks_copy;
1303
1304 /* Copy the current lock array. */
1305 if (br_lck->num_locks) {
1306 locks_copy = (struct lock_struct *)TALLOC_MEMDUP(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1307 if (!locks_copy) {
1308 smb_panic("brl_close_fnum: talloc fail.\n");
1309 }
1310 } else {
1311 locks_copy = NULL;
1312 }
1313
1314 num_locks_copy = br_lck->num_locks;
1315
1316 for (i=0; i < num_locks_copy; i++) {
1317 struct lock_struct *lock = &locks_copy[i];
1318
1319 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid) &&
1320 (lock->fnum == fnum)) {
1321 brl_unlock(br_lck,
1322 lock->context.smbpid,
1323 pid,
1324 lock->start,
1325 lock->size,
1326 lock->lock_flav);
1327 }
1328 }
1329 return;
1330 }
1331 }
1332
1333 /* We can bulk delete - any POSIX locks will be removed when the fd closes. */
1334
1335 /* Remove any existing locks for this fnum (or any fnum if they're POSIX). */
1336
1337 for (i=0; i < br_lck->num_locks; i++) {
1338 struct lock_struct *lock = &locks[i];
1339 BOOL del_this_lock = False;
1340
1341 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid)) {
1342 if ((lock->lock_flav == WINDOWS_LOCK) && (lock->fnum == fnum)) {
1343 del_this_lock = True;
1344 num_deleted_windows_locks++;
1345 } else if (lock->lock_flav == POSIX_LOCK) {
1346 del_this_lock = True;
1347 }
1348 }
1349
1350 if (del_this_lock) {
1351 /* Send unlock messages to any pending waiters that overlap. */
1352 for (j=0; j < br_lck->num_locks; j++) {
1353 struct lock_struct *pend_lock = &locks[j];
1354
1355 /* Ignore our own or non-pending locks. */
1356 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1357 continue;
1358 }
1359
1360 /* Optimisation - don't send to this fnum as we're
1361 closing it. */
1362 if (pend_lock->context.tid == tid &&
1363 procid_equal(&pend_lock->context.pid, &pid) &&
1364 pend_lock->fnum == fnum) {
1365 continue;
1366 }
1367
1368 /* We could send specific lock info here... */
1369 if (brl_pending_overlap(lock, pend_lock)) {
1370 message_send_pid(pend_lock->context.pid,
1371 MSG_SMB_UNLOCK,
1372 NULL, 0, True);
1373 }
1374 }
1375
1376 /* found it - delete it */
1377 if (br_lck->num_locks > 1 && i < br_lck->num_locks - 1) {
1378 memmove(&locks[i], &locks[i+1],
1379 sizeof(*locks)*((br_lck->num_locks-1) - i));
1380 }
1381 br_lck->num_locks--;
1382 br_lck->modified = True;
1383 i--;
1384 dcount++;
1385 }
1386 }
1387
1388 if(lp_posix_locking(fsp->conn->params) && num_deleted_windows_locks) {
1389 /* Reduce the Windows lock POSIX reference count on this dev/ino pair. */
1390 reduce_windows_lock_ref_count(fsp, num_deleted_windows_locks);
1391 }
1392 }
1393
1394 /****************************************************************************
1395 Ensure this set of lock entries is valid.
1396 ****************************************************************************/
1397
1398 static BOOL validate_lock_entries(unsigned int *pnum_entries, struct lock_struct **pplocks)
1399 {
1400 unsigned int i;
1401 unsigned int num_valid_entries = 0;
1402 struct lock_struct *locks = *pplocks;
1403
1404 for (i = 0; i < *pnum_entries; i++) {
1405 struct lock_struct *lock_data = &locks[i];
1406 if (!process_exists(lock_data->context.pid)) {
1407 /* This process no longer exists - mark this
1408 entry as invalid by zeroing it. */
1409 ZERO_STRUCTP(lock_data);
1410 } else {
1411 num_valid_entries++;
1412 }
1413 }
1414
1415 if (num_valid_entries != *pnum_entries) {
1416 struct lock_struct *new_lock_data = NULL;
1417
1418 if (num_valid_entries) {
1419 new_lock_data = SMB_MALLOC_ARRAY(struct lock_struct, num_valid_entries);
1420 if (!new_lock_data) {
1421 DEBUG(3, ("malloc fail\n"));
1422 return False;
1423 }
1424
1425 num_valid_entries = 0;
1426 for (i = 0; i < *pnum_entries; i++) {
1427 struct lock_struct *lock_data = &locks[i];
1428 if (lock_data->context.smbpid &&
1429 lock_data->context.tid) {
1430 /* Valid (nonzero) entry - copy it. */
1431 memcpy(&new_lock_data[num_valid_entries],
1432 lock_data, sizeof(struct lock_struct));
1433 num_valid_entries++;
1434 }
1435 }
1436 }
1437
1438 SAFE_FREE(*pplocks);
1439 *pplocks = new_lock_data;
1440 *pnum_entries = num_valid_entries;
1441 }
1442
1443 return True;
1444 }
1445
1446 /****************************************************************************
1447 Traverse the whole database with this function, calling traverse_callback
1448 on each lock.
1449 ****************************************************************************/
1450
1451 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
1452 {
1453 struct lock_struct *locks;
1454 struct lock_key *key;
1455 unsigned int i;
1456 unsigned int num_locks = 0;
1457 unsigned int orig_num_locks = 0;
1458
1459 BRLOCK_FN(traverse_callback) = (BRLOCK_FN_CAST())state;
1460
1461 /* In a traverse function we must make a copy of
1462 dbuf before modifying it. */
1463
1464 locks = (struct lock_struct *)memdup(dbuf.dptr, dbuf.dsize);
1465 if (!locks) {
1466 return -1; /* Terminate traversal. */
1467 }
1468
1469 key = (struct lock_key *)kbuf.dptr;
1470 orig_num_locks = num_locks = dbuf.dsize/sizeof(*locks);
1471
1472 /* Ensure the lock db is clean of entries from invalid processes. */
1473
1474 if (!validate_lock_entries(&num_locks, &locks)) {
1475 SAFE_FREE(locks);
1476 return -1; /* Terminate traversal */
1477 }
1478
1479 if (orig_num_locks != num_locks) {
1480 dbuf.dptr = (char *)locks;
1481 dbuf.dsize = num_locks * sizeof(*locks);
1482
1483 if (dbuf.dsize) {
1484 tdb_store(ttdb, kbuf, dbuf, TDB_REPLACE);
1485 } else {
1486 tdb_delete(ttdb, kbuf);
1487 }
1488 }
1489
1490 for ( i=0; i<num_locks; i++) {
1491 traverse_callback(key->device,
1492 key->inode,
1493 locks[i].context.pid,
1494 locks[i].lock_type,
1495 locks[i].lock_flav,
1496 locks[i].start,
1497 locks[i].size);
1498 }
1499
1500 SAFE_FREE(locks);
1501 return 0;
1502 }
1503
1504 /*******************************************************************
1505 Call the specified function on each lock in the database.
1506 ********************************************************************/
1507
1508 int brl_forall(BRLOCK_FN(fn))
1509 {
1510 if (!tdb) {
1511 return 0;
1512 }
1513 return tdb_traverse(tdb, traverse_fn, (void *)fn);
1514 }
1515
1516 /*******************************************************************
1517 Store a potentially modified set of byte range lock data back into
1518 the database.
1519 Unlock the record.
1520 ********************************************************************/
1521
1522 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1523 {
1524 TDB_DATA key;
1525
1526 key.dptr = (char *)&br_lck->key;
1527 key.dsize = sizeof(struct lock_key);
1528
1529 if (br_lck->read_only) {
1530 SMB_ASSERT(!br_lck->modified);
1531 }
1532
1533 if (!br_lck->modified) {
1534 goto done;
1535 }
1536
1537 if (br_lck->num_locks == 0) {
1538 /* No locks - delete this entry. */
1539 if (tdb_delete(tdb, key) == -1) {
1540 smb_panic("Could not delete byte range lock entry\n");
1541 }
1542 } else {
1543 TDB_DATA data;
1544 data.dptr = (char *)br_lck->lock_data;
1545 data.dsize = br_lck->num_locks * sizeof(struct lock_struct);
1546
1547 if (tdb_store(tdb, key, data, TDB_REPLACE) == -1) {
1548 smb_panic("Could not store byte range mode entry\n");
1549 }
1550 }
1551
1552 done:
1553
1554 if (!br_lck->read_only) {
1555 tdb_chainunlock(tdb, key);
1556 }
1557 SAFE_FREE(br_lck->lock_data);
1558 return 0;
1559 }
1560
1561 /*******************************************************************
1562 Fetch a set of byte range lock data from the database.
1563 Leave the record locked.
1564 TALLOC_FREE(brl) will release the lock in the destructor.
1565 ********************************************************************/
1566
1567 static struct byte_range_lock *brl_get_locks_internal(TALLOC_CTX *mem_ctx,
1568 files_struct *fsp, BOOL read_only)
1569 {
1570 TDB_DATA key;
1571 TDB_DATA data;
1572 struct byte_range_lock *br_lck = TALLOC_P(mem_ctx, struct byte_range_lock);
1573
1574 if (br_lck == NULL) {
1575 return NULL;
1576 }
1577
1578 br_lck->fsp = fsp;
1579 br_lck->num_locks = 0;
1580 br_lck->modified = False;
1581 memset(&br_lck->key, '\0', sizeof(struct lock_key));
1582 br_lck->key.device = fsp->dev;
1583 br_lck->key.inode = fsp->inode;
1584
1585 key.dptr = (char *)&br_lck->key;
1586 key.dsize = sizeof(struct lock_key);
1587
1588 if (!fsp->lockdb_clean) {
1589 /* We must be read/write to clean
1590 the dead entries. */
1591 read_only = False;
1592 }
1593
1594 if (read_only) {
1595 br_lck->read_only = True;
1596 } else {
1597 if (tdb_chainlock(tdb, key) != 0) {
1598 DEBUG(3, ("Could not lock byte range lock entry\n"));
1599 TALLOC_FREE(br_lck);
1600 return NULL;
1601 }
1602 br_lck->read_only = False;
1603 }
1604
1605 talloc_set_destructor(br_lck, byte_range_lock_destructor);
1606
1607 data = tdb_fetch(tdb, key);
1608 br_lck->lock_data = (void *)data.dptr;
1609 br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1610
1611 if (!fsp->lockdb_clean) {
1612 int orig_num_locks = br_lck->num_locks;
1613
1614 /* This is the first time we've accessed this. */
1615 /* Go through and ensure all entries exist - remove any that don't. */
1616 /* Makes the lockdb self cleaning at low cost. */
1617
1618 struct lock_struct *locks =
1619 (struct lock_struct *)br_lck->lock_data;
1620
1621 if (!validate_lock_entries(&br_lck->num_locks, &locks)) {
1622 SAFE_FREE(br_lck->lock_data);
1623 TALLOC_FREE(br_lck);
1624 return NULL;
1625 }
1626
1627 /* Ensure invalid locks are cleaned up in the destructor. */
1628 if (orig_num_locks != br_lck->num_locks) {
1629 br_lck->modified = True;
1630 }
1631
1632 /*
1633 * validate_lock_entries might have changed locks. We can't
1634 * use a direct pointer here because otherwise gcc warnes
1635 * about strict aliasing rules being violated.
1636 */
1637 br_lck->lock_data = locks;
1638
1639 /* Mark the lockdb as "clean" as seen from this open file. */
1640 fsp->lockdb_clean = True;
1641 }
1642
1643 if (DEBUGLEVEL >= 10) {
1644 unsigned int i;
1645 struct lock_struct *locks = (struct lock_struct *)br_lck->lock_data;
1646 DEBUG(10,("brl_get_locks_internal: %u current locks on dev=%.0f, inode=%.0f\n",
1647 br_lck->num_locks,
1648 (double)fsp->dev, (double)fsp->inode ));
1649 for( i = 0; i < br_lck->num_locks; i++) {
1650 print_lock_struct(i, &locks[i]);
1651 }
1652 }
1653 return br_lck;
1654 }
1655
1656 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
1657 files_struct *fsp)
1658 {
1659 return brl_get_locks_internal(mem_ctx, fsp, False);
1660 }
1661
1662 struct byte_range_lock *brl_get_locks_readonly(TALLOC_CTX *mem_ctx,
1663 files_struct *fsp)
1664 {
1665 return brl_get_locks_internal(mem_ctx, fsp, True);
1666 }
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