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s3: Fix uninitialized memory read in talloc_free()
[Samba.git] / source3 / locking / brlock.c
blob22c6c9e5b3312655c9412b5294b0271c05965fa0
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 3 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, see <http://www.gnu.org/licenses/>.
21 */
22
23 /* This module implements a tdb based byte range locking service,
24 replacing the fcntl() based byte range locking previously
25 used. This allows us to provide the same semantics as NT */
26
27 #include "includes.h"
28
29 #undef DBGC_CLASS
30 #define DBGC_CLASS DBGC_LOCKING
31
32 #define ZERO_ZERO 0
33
34 /* The open brlock.tdb database. */
35
36 static struct db_context *brlock_db;
37
38 /****************************************************************************
39 Debug info at level 10 for lock struct.
40 ****************************************************************************/
41
42 static void print_lock_struct(unsigned int i, struct lock_struct *pls)
43 {
44 DEBUG(10,("[%u]: smbpid = %u, tid = %u, pid = %s, ",
45 i,
46 (unsigned int)pls->context.smbpid,
47 (unsigned int)pls->context.tid,
48 procid_str(talloc_tos(), &pls->context.pid) ));
49
50 DEBUG(10,("start = %.0f, size = %.0f, fnum = %d, %s %s\n",
51 (double)pls->start,
52 (double)pls->size,
53 pls->fnum,
54 lock_type_name(pls->lock_type),
55 lock_flav_name(pls->lock_flav) ));
56 }
57
58 /****************************************************************************
59 See if two locking contexts are equal.
60 ****************************************************************************/
61
62 bool brl_same_context(const struct lock_context *ctx1,
63 const struct lock_context *ctx2)
64 {
65 return (procid_equal(&ctx1->pid, &ctx2->pid) &&
66 (ctx1->smbpid == ctx2->smbpid) &&
67 (ctx1->tid == ctx2->tid));
68 }
69
70 /****************************************************************************
71 See if lck1 and lck2 overlap.
72 ****************************************************************************/
73
74 static bool brl_overlap(const struct lock_struct *lck1,
75 const struct lock_struct *lck2)
76 {
77 /* XXX Remove for Win7 compatibility. */
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 /* A READ lock can stack on top of a WRITE lock if they have the same
110 * context & fnum. */
111 if (lck1->lock_type == WRITE_LOCK && lck2->lock_type == READ_LOCK &&
112 brl_same_context(&lck1->context, &lck2->context) &&
113 lck1->fnum == lck2->fnum) {
114 return False;
115 }
116
117 return brl_overlap(lck1, lck2);
118 }
119
120 /****************************************************************************
121 See if lock2 can be added when lock1 is in place - when both locks are POSIX
122 flavour. POSIX locks ignore fnum - they only care about dev/ino which we
123 know already match.
124 ****************************************************************************/
125
126 static bool brl_conflict_posix(const struct lock_struct *lck1,
127 const struct lock_struct *lck2)
128 {
129 #if defined(DEVELOPER)
130 SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
131 SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
132 #endif
133
134 /* Ignore PENDING locks. */
135 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
136 return False;
137
138 /* Read locks never conflict. */
139 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
140 return False;
141 }
142
143 /* Locks on the same context con't conflict. Ignore fnum. */
144 if (brl_same_context(&lck1->context, &lck2->context)) {
145 return False;
146 }
147
148 /* One is read, the other write, or the context is different,
149 do they overlap ? */
150 return brl_overlap(lck1, lck2);
151 }
152
153 #if ZERO_ZERO
154 static bool brl_conflict1(const struct lock_struct *lck1,
155 const struct lock_struct *lck2)
156 {
157 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
158 return False;
159
160 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
161 return False;
162 }
163
164 if (brl_same_context(&lck1->context, &lck2->context) &&
165 lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
166 return False;
167 }
168
169 if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
170 return True;
171 }
172
173 if (lck1->start >= (lck2->start + lck2->size) ||
174 lck2->start >= (lck1->start + lck1->size)) {
175 return False;
176 }
177
178 return True;
179 }
180 #endif
181
182 /****************************************************************************
183 Check to see if this lock conflicts, but ignore our own locks on the
184 same fnum only. This is the read/write lock check code path.
185 This is never used in the POSIX lock case.
186 ****************************************************************************/
187
188 static bool brl_conflict_other(const struct lock_struct *lck1, const struct lock_struct *lck2)
189 {
190 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
191 return False;
192
193 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
194 return False;
195
196 /* POSIX flavour locks never conflict here - this is only called
197 in the read/write path. */
198
199 if (lck1->lock_flav == POSIX_LOCK && lck2->lock_flav == POSIX_LOCK)
200 return False;
201
202 /*
203 * Incoming WRITE locks conflict with existing READ locks even
204 * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
205 */
206
207 if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
208 if (brl_same_context(&lck1->context, &lck2->context) &&
209 lck1->fnum == lck2->fnum)
210 return False;
211 }
212
213 return brl_overlap(lck1, lck2);
214 }
215
216 /****************************************************************************
217 Check if an unlock overlaps a pending lock.
218 ****************************************************************************/
219
220 static bool brl_pending_overlap(const struct lock_struct *lock, const struct lock_struct *pend_lock)
221 {
222 if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
223 return True;
224 if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
225 return True;
226 return False;
227 }
228
229 /****************************************************************************
230 Amazingly enough, w2k3 "remembers" whether the last lock failure on a fnum
231 is the same as this one and changes its error code. I wonder if any
232 app depends on this ?
233 ****************************************************************************/
234
235 NTSTATUS brl_lock_failed(files_struct *fsp, const struct lock_struct *lock, bool blocking_lock)
236 {
237 if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
238 /* amazing the little things you learn with a test
239 suite. Locks beyond this offset (as a 64 bit
240 number!) always generate the conflict error code,
241 unless the top bit is set */
242 if (!blocking_lock) {
243 fsp->last_lock_failure = *lock;
244 }
245 return NT_STATUS_FILE_LOCK_CONFLICT;
246 }
247
248 if (procid_equal(&lock->context.pid, &fsp->last_lock_failure.context.pid) &&
249 lock->context.tid == fsp->last_lock_failure.context.tid &&
250 lock->fnum == fsp->last_lock_failure.fnum &&
251 lock->start == fsp->last_lock_failure.start) {
252 return NT_STATUS_FILE_LOCK_CONFLICT;
253 }
254
255 if (!blocking_lock) {
256 fsp->last_lock_failure = *lock;
257 }
258 return NT_STATUS_LOCK_NOT_GRANTED;
259 }
260
261 /****************************************************************************
262 Open up the brlock.tdb database.
263 ****************************************************************************/
264
265 void brl_init(bool read_only)
266 {
267 int tdb_flags;
268
269 if (brlock_db) {
270 return;
271 }
272
273 tdb_flags = TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST;
274
275 if (!lp_clustering()) {
276 /*
277 * We can't use the SEQNUM trick to cache brlock
278 * entries in the clustering case because ctdb seqnum
279 * propagation has a delay.
280 */
281 tdb_flags |= TDB_SEQNUM;
282 }
283
284 brlock_db = db_open(NULL, lock_path("brlock.tdb"),
285 lp_open_files_db_hash_size(), tdb_flags,
286 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644 );
287 if (!brlock_db) {
288 DEBUG(0,("Failed to open byte range locking database %s\n",
289 lock_path("brlock.tdb")));
290 return;
291 }
292 }
293
294 /****************************************************************************
295 Close down the brlock.tdb database.
296 ****************************************************************************/
297
298 void brl_shutdown(void)
299 {
300 TALLOC_FREE(brlock_db);
301 }
302
303 #if ZERO_ZERO
304 /****************************************************************************
305 Compare two locks for sorting.
306 ****************************************************************************/
307
308 static int lock_compare(const struct lock_struct *lck1,
309 const struct lock_struct *lck2)
310 {
311 if (lck1->start != lck2->start) {
312 return (lck1->start - lck2->start);
313 }
314 if (lck2->size != lck1->size) {
315 return ((int)lck1->size - (int)lck2->size);
316 }
317 return 0;
318 }
319 #endif
320
321 /****************************************************************************
322 Lock a range of bytes - Windows lock semantics.
323 ****************************************************************************/
324
325 NTSTATUS brl_lock_windows_default(struct byte_range_lock *br_lck,
326 struct lock_struct *plock, bool blocking_lock)
327 {
328 unsigned int i;
329 files_struct *fsp = br_lck->fsp;
330 struct lock_struct *locks = br_lck->lock_data;
331 NTSTATUS status;
332
333 SMB_ASSERT(plock->lock_type != UNLOCK_LOCK);
334
335 for (i=0; i < br_lck->num_locks; i++) {
336 if (locks[i].start + locks[i].size < locks[i].start) {
337 /* 64-bit wrap. Error. */
338 return NT_STATUS_INVALID_LOCK_RANGE;
339 }
340
341 /* Do any Windows or POSIX locks conflict ? */
342 if (brl_conflict(&locks[i], plock)) {
343 /* Remember who blocked us. */
344 plock->context.smbpid = locks[i].context.smbpid;
345 return brl_lock_failed(fsp,plock,blocking_lock);
346 }
347 #if ZERO_ZERO
348 if (plock->start == 0 && plock->size == 0 &&
349 locks[i].size == 0) {
350 break;
351 }
352 #endif
353 }
354
355 if (!IS_PENDING_LOCK(plock->lock_type)) {
356 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
357 }
358
359 /* We can get the Windows lock, now see if it needs to
360 be mapped into a lower level POSIX one, and if so can
361 we get it ? */
362
363 if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(fsp->conn->params)) {
364 int errno_ret;
365 if (!set_posix_lock_windows_flavour(fsp,
366 plock->start,
367 plock->size,
368 plock->lock_type,
369 &plock->context,
370 locks,
371 br_lck->num_locks,
372 &errno_ret)) {
373
374 /* We don't know who blocked us. */
375 plock->context.smbpid = 0xFFFFFFFF;
376
377 if (errno_ret == EACCES || errno_ret == EAGAIN) {
378 status = NT_STATUS_FILE_LOCK_CONFLICT;
379 goto fail;
380 } else {
381 status = map_nt_error_from_unix(errno);
382 goto fail;
383 }
384 }
385 }
386
387 /* no conflicts - add it to the list of locks */
388 locks = (struct lock_struct *)SMB_REALLOC(locks, (br_lck->num_locks + 1) * sizeof(*locks));
389 if (!locks) {
390 status = NT_STATUS_NO_MEMORY;
391 goto fail;
392 }
393
394 memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
395 br_lck->num_locks += 1;
396 br_lck->lock_data = locks;
397 br_lck->modified = True;
398
399 return NT_STATUS_OK;
400 fail:
401 if (!IS_PENDING_LOCK(plock->lock_type)) {
402 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
403 }
404 return status;
405 }
406
407 /****************************************************************************
408 Cope with POSIX range splits and merges.
409 ****************************************************************************/
410
411 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr, /* Output array. */
412 struct lock_struct *ex, /* existing lock. */
413 struct lock_struct *plock) /* proposed lock. */
414 {
415 bool lock_types_differ = (ex->lock_type != plock->lock_type);
416
417 /* We can't merge non-conflicting locks on different context - ignore fnum. */
418
419 if (!brl_same_context(&ex->context, &plock->context)) {
420 /* Just copy. */
421 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
422 return 1;
423 }
424
425 /* We now know we have the same context. */
426
427 /* Did we overlap ? */
428
429 /*********************************************
430 +---------+
431 | ex |
432 +---------+
433 +-------+
434 | plock |
435 +-------+
436 OR....
437 +---------+
438 | ex |
439 +---------+
440 **********************************************/
441
442 if ( (ex->start > (plock->start + plock->size)) ||
443 (plock->start > (ex->start + ex->size))) {
444
445 /* No overlap with this lock - copy existing. */
446
447 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
448 return 1;
449 }
450
451 /*********************************************
452 +---------------------------+
453 | ex |
454 +---------------------------+
455 +---------------------------+
456 | plock | -> replace with plock.
457 +---------------------------+
458 OR
459 +---------------+
460 | ex |
461 +---------------+
462 +---------------------------+
463 | plock | -> replace with plock.
464 +---------------------------+
465
466 **********************************************/
467
468 if ( (ex->start >= plock->start) &&
469 (ex->start + ex->size <= plock->start + plock->size) ) {
470
471 /* Replace - discard existing lock. */
472
473 return 0;
474 }
475
476 /*********************************************
477 Adjacent after.
478 +-------+
479 | ex |
480 +-------+
481 +---------------+
482 | plock |
483 +---------------+
484
485 BECOMES....
486 +---------------+-------+
487 | plock | ex | - different lock types.
488 +---------------+-------+
489 OR.... (merge)
490 +-----------------------+
491 | plock | - same lock type.
492 +-----------------------+
493 **********************************************/
494
495 if (plock->start + plock->size == ex->start) {
496
497 /* If the lock types are the same, we merge, if different, we
498 add the remainder of the old lock. */
499
500 if (lock_types_differ) {
501 /* Add existing. */
502 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
503 return 1;
504 } else {
505 /* Merge - adjust incoming lock as we may have more
506 * merging to come. */
507 plock->size += ex->size;
508 return 0;
509 }
510 }
511
512 /*********************************************
513 Adjacent before.
514 +-------+
515 | ex |
516 +-------+
517 +---------------+
518 | plock |
519 +---------------+
520 BECOMES....
521 +-------+---------------+
522 | ex | plock | - different lock types
523 +-------+---------------+
524
525 OR.... (merge)
526 +-----------------------+
527 | plock | - same lock type.
528 +-----------------------+
529
530 **********************************************/
531
532 if (ex->start + ex->size == plock->start) {
533
534 /* If the lock types are the same, we merge, if different, we
535 add the existing lock. */
536
537 if (lock_types_differ) {
538 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
539 return 1;
540 } else {
541 /* Merge - adjust incoming lock as we may have more
542 * merging to come. */
543 plock->start = ex->start;
544 plock->size += ex->size;
545 return 0;
546 }
547 }
548
549 /*********************************************
550 Overlap after.
551 +-----------------------+
552 | ex |
553 +-----------------------+
554 +---------------+
555 | plock |
556 +---------------+
557 OR
558 +----------------+
559 | ex |
560 +----------------+
561 +---------------+
562 | plock |
563 +---------------+
564
565 BECOMES....
566 +---------------+-------+
567 | plock | ex | - different lock types.
568 +---------------+-------+
569 OR.... (merge)
570 +-----------------------+
571 | plock | - same lock type.
572 +-----------------------+
573 **********************************************/
574
575 if ( (ex->start >= plock->start) &&
576 (ex->start <= plock->start + plock->size) &&
577 (ex->start + ex->size > plock->start + plock->size) ) {
578
579 /* If the lock types are the same, we merge, if different, we
580 add the remainder of the old lock. */
581
582 if (lock_types_differ) {
583 /* Add remaining existing. */
584 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
585 /* Adjust existing start and size. */
586 lck_arr[0].start = plock->start + plock->size;
587 lck_arr[0].size = (ex->start + ex->size) - (plock->start + plock->size);
588 return 1;
589 } else {
590 /* Merge - adjust incoming lock as we may have more
591 * merging to come. */
592 plock->size += (ex->start + ex->size) - (plock->start + plock->size);
593 return 0;
594 }
595 }
596
597 /*********************************************
598 Overlap before.
599 +-----------------------+
600 | ex |
601 +-----------------------+
602 +---------------+
603 | plock |
604 +---------------+
605 OR
606 +-------------+
607 | ex |
608 +-------------+
609 +---------------+
610 | plock |
611 +---------------+
612
613 BECOMES....
614 +-------+---------------+
615 | ex | plock | - different lock types
616 +-------+---------------+
617
618 OR.... (merge)
619 +-----------------------+
620 | plock | - same lock type.
621 +-----------------------+
622
623 **********************************************/
624
625 if ( (ex->start < plock->start) &&
626 (ex->start + ex->size >= plock->start) &&
627 (ex->start + ex->size <= plock->start + plock->size) ) {
628
629 /* If the lock types are the same, we merge, if different, we
630 add the truncated old lock. */
631
632 if (lock_types_differ) {
633 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
634 /* Adjust existing size. */
635 lck_arr[0].size = plock->start - ex->start;
636 return 1;
637 } else {
638 /* Merge - adjust incoming lock as we may have more
639 * merging to come. MUST ADJUST plock SIZE FIRST ! */
640 plock->size += (plock->start - ex->start);
641 plock->start = ex->start;
642 return 0;
643 }
644 }
645
646 /*********************************************
647 Complete overlap.
648 +---------------------------+
649 | ex |
650 +---------------------------+
651 +---------+
652 | plock |
653 +---------+
654 BECOMES.....
655 +-------+---------+---------+
656 | ex | plock | ex | - different lock types.
657 +-------+---------+---------+
658 OR
659 +---------------------------+
660 | plock | - same lock type.
661 +---------------------------+
662 **********************************************/
663
664 if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
665
666 if (lock_types_differ) {
667
668 /* We have to split ex into two locks here. */
669
670 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
671 memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
672
673 /* Adjust first existing size. */
674 lck_arr[0].size = plock->start - ex->start;
675
676 /* Adjust second existing start and size. */
677 lck_arr[1].start = plock->start + plock->size;
678 lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
679 return 2;
680 } else {
681 /* Just eat the existing locks, merge them into plock. */
682 plock->start = ex->start;
683 plock->size = ex->size;
684 return 0;
685 }
686 }
687
688 /* Never get here. */
689 smb_panic("brlock_posix_split_merge");
690 /* Notreached. */
691
692 /* Keep some compilers happy. */
693 return 0;
694 }
695
696 /****************************************************************************
697 Lock a range of bytes - POSIX lock semantics.
698 We must cope with range splits and merges.
699 ****************************************************************************/
700
701 static NTSTATUS brl_lock_posix(struct messaging_context *msg_ctx,
702 struct byte_range_lock *br_lck,
703 struct lock_struct *plock)
704 {
705 unsigned int i, count, posix_count;
706 struct lock_struct *locks = br_lck->lock_data;
707 struct lock_struct *tp;
708 bool signal_pending_read = False;
709 bool break_oplocks = false;
710 NTSTATUS status;
711
712 /* No zero-zero locks for POSIX. */
713 if (plock->start == 0 && plock->size == 0) {
714 return NT_STATUS_INVALID_PARAMETER;
715 }
716
717 /* Don't allow 64-bit lock wrap. */
718 if (plock->start + plock->size < plock->start ||
719 plock->start + plock->size < plock->size) {
720 return NT_STATUS_INVALID_PARAMETER;
721 }
722
723 /* The worst case scenario here is we have to split an
724 existing POSIX lock range into two, and add our lock,
725 so we need at most 2 more entries. */
726
727 tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 2));
728 if (!tp) {
729 return NT_STATUS_NO_MEMORY;
730 }
731
732 count = posix_count = 0;
733
734 for (i=0; i < br_lck->num_locks; i++) {
735 struct lock_struct *curr_lock = &locks[i];
736
737 /* If we have a pending read lock, a lock downgrade should
738 trigger a lock re-evaluation. */
739 if (curr_lock->lock_type == PENDING_READ_LOCK &&
740 brl_pending_overlap(plock, curr_lock)) {
741 signal_pending_read = True;
742 }
743
744 if (curr_lock->lock_flav == WINDOWS_LOCK) {
745 /* Do any Windows flavour locks conflict ? */
746 if (brl_conflict(curr_lock, plock)) {
747 /* No games with error messages. */
748 SAFE_FREE(tp);
749 /* Remember who blocked us. */
750 plock->context.smbpid = curr_lock->context.smbpid;
751 return NT_STATUS_FILE_LOCK_CONFLICT;
752 }
753 /* Just copy the Windows lock into the new array. */
754 memcpy(&tp[count], curr_lock, sizeof(struct lock_struct));
755 count++;
756 } else {
757 unsigned int tmp_count = 0;
758
759 /* POSIX conflict semantics are different. */
760 if (brl_conflict_posix(curr_lock, plock)) {
761 /* Can't block ourselves with POSIX locks. */
762 /* No games with error messages. */
763 SAFE_FREE(tp);
764 /* Remember who blocked us. */
765 plock->context.smbpid = curr_lock->context.smbpid;
766 return NT_STATUS_FILE_LOCK_CONFLICT;
767 }
768
769 /* Work out overlaps. */
770 tmp_count += brlock_posix_split_merge(&tp[count], curr_lock, plock);
771 posix_count += tmp_count;
772 count += tmp_count;
773 }
774 }
775
776 /*
777 * Break oplocks while we hold a brl. Since lock() and unlock() calls
778 * are not symetric with POSIX semantics, we cannot guarantee our
779 * contend_level2_oplocks_begin/end calls will be acquired and
780 * released one-for-one as with Windows semantics. Therefore we only
781 * call contend_level2_oplocks_begin if this is the first POSIX brl on
782 * the file.
783 */
784 break_oplocks = (!IS_PENDING_LOCK(plock->lock_type) &&
785 posix_count == 0);
786 if (break_oplocks) {
787 contend_level2_oplocks_begin(br_lck->fsp,
788 LEVEL2_CONTEND_POSIX_BRL);
789 }
790
791 /* Try and add the lock in order, sorted by lock start. */
792 for (i=0; i < count; i++) {
793 struct lock_struct *curr_lock = &tp[i];
794
795 if (curr_lock->start <= plock->start) {
796 continue;
797 }
798 }
799
800 if (i < count) {
801 memmove(&tp[i+1], &tp[i],
802 (count - i)*sizeof(struct lock_struct));
803 }
804 memcpy(&tp[i], plock, sizeof(struct lock_struct));
805 count++;
806
807 /* We can get the POSIX lock, now see if it needs to
808 be mapped into a lower level POSIX one, and if so can
809 we get it ? */
810
811 if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(br_lck->fsp->conn->params)) {
812 int errno_ret;
813
814 /* The lower layer just needs to attempt to
815 get the system POSIX lock. We've weeded out
816 any conflicts above. */
817
818 if (!set_posix_lock_posix_flavour(br_lck->fsp,
819 plock->start,
820 plock->size,
821 plock->lock_type,
822 &errno_ret)) {
823
824 /* We don't know who blocked us. */
825 plock->context.smbpid = 0xFFFFFFFF;
826
827 if (errno_ret == EACCES || errno_ret == EAGAIN) {
828 SAFE_FREE(tp);
829 status = NT_STATUS_FILE_LOCK_CONFLICT;
830 goto fail;
831 } else {
832 SAFE_FREE(tp);
833 status = map_nt_error_from_unix(errno);
834 goto fail;
835 }
836 }
837 }
838
839 /* If we didn't use all the allocated size,
840 * Realloc so we don't leak entries per lock call. */
841 if (count < br_lck->num_locks + 2) {
842 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
843 if (!tp) {
844 status = NT_STATUS_NO_MEMORY;
845 goto fail;
846 }
847 }
848
849 br_lck->num_locks = count;
850 SAFE_FREE(br_lck->lock_data);
851 br_lck->lock_data = tp;
852 locks = tp;
853 br_lck->modified = True;
854
855 /* A successful downgrade from write to read lock can trigger a lock
856 re-evalutation where waiting readers can now proceed. */
857
858 if (signal_pending_read) {
859 /* Send unlock messages to any pending read waiters that overlap. */
860 for (i=0; i < br_lck->num_locks; i++) {
861 struct lock_struct *pend_lock = &locks[i];
862
863 /* Ignore non-pending locks. */
864 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
865 continue;
866 }
867
868 if (pend_lock->lock_type == PENDING_READ_LOCK &&
869 brl_pending_overlap(plock, pend_lock)) {
870 DEBUG(10,("brl_lock_posix: sending unlock message to pid %s\n",
871 procid_str_static(&pend_lock->context.pid )));
872
873 messaging_send(msg_ctx, pend_lock->context.pid,
874 MSG_SMB_UNLOCK, &data_blob_null);
875 }
876 }
877 }
878
879 return NT_STATUS_OK;
880 fail:
881 if (break_oplocks) {
882 contend_level2_oplocks_end(br_lck->fsp,
883 LEVEL2_CONTEND_POSIX_BRL);
884 }
885 return status;
886 }
887
888 NTSTATUS smb_vfs_call_brl_lock_windows(struct vfs_handle_struct *handle,
889 struct byte_range_lock *br_lck,
890 struct lock_struct *plock,
891 bool blocking_lock,
892 struct blocking_lock_record *blr)
893 {
894 VFS_FIND(brl_lock_windows);
895 return handle->fns->brl_lock_windows(handle, br_lck, plock,
896 blocking_lock, blr);
897 }
898
899 /****************************************************************************
900 Lock a range of bytes.
901 ****************************************************************************/
902
903 NTSTATUS brl_lock(struct messaging_context *msg_ctx,
904 struct byte_range_lock *br_lck,
905 uint32 smbpid,
906 struct server_id pid,
907 br_off start,
908 br_off size,
909 enum brl_type lock_type,
910 enum brl_flavour lock_flav,
911 bool blocking_lock,
912 uint32 *psmbpid,
913 struct blocking_lock_record *blr)
914 {
915 NTSTATUS ret;
916 struct lock_struct lock;
917
918 #if !ZERO_ZERO
919 if (start == 0 && size == 0) {
920 DEBUG(0,("client sent 0/0 lock - please report this\n"));
921 }
922 #endif
923
924 #ifdef DEVELOPER
925 /* Quieten valgrind on test. */
926 memset(&lock, '\0', sizeof(lock));
927 #endif
928
929 lock.context.smbpid = smbpid;
930 lock.context.pid = pid;
931 lock.context.tid = br_lck->fsp->conn->cnum;
932 lock.start = start;
933 lock.size = size;
934 lock.fnum = br_lck->fsp->fnum;
935 lock.lock_type = lock_type;
936 lock.lock_flav = lock_flav;
937
938 if (lock_flav == WINDOWS_LOCK) {
939 ret = SMB_VFS_BRL_LOCK_WINDOWS(br_lck->fsp->conn, br_lck,
940 &lock, blocking_lock, blr);
941 } else {
942 ret = brl_lock_posix(msg_ctx, br_lck, &lock);
943 }
944
945 #if ZERO_ZERO
946 /* sort the lock list */
947 qsort(br_lck->lock_data, (size_t)br_lck->num_locks, sizeof(lock), lock_compare);
948 #endif
949
950 /* If we're returning an error, return who blocked us. */
951 if (!NT_STATUS_IS_OK(ret) && psmbpid) {
952 *psmbpid = lock.context.smbpid;
953 }
954 return ret;
955 }
956
957 /****************************************************************************
958 Unlock a range of bytes - Windows semantics.
959 ****************************************************************************/
960
961 bool brl_unlock_windows_default(struct messaging_context *msg_ctx,
962 struct byte_range_lock *br_lck,
963 const struct lock_struct *plock)
964 {
965 unsigned int i, j;
966 struct lock_struct *locks = br_lck->lock_data;
967 enum brl_type deleted_lock_type = READ_LOCK; /* shut the compiler up.... */
968
969 SMB_ASSERT(plock->lock_type == UNLOCK_LOCK);
970
971 #if ZERO_ZERO
972 /* Delete write locks by preference... The lock list
973 is sorted in the zero zero case. */
974
975 for (i = 0; i < br_lck->num_locks; i++) {
976 struct lock_struct *lock = &locks[i];
977
978 if (lock->lock_type == WRITE_LOCK &&
979 brl_same_context(&lock->context, &plock->context) &&
980 lock->fnum == plock->fnum &&
981 lock->lock_flav == WINDOWS_LOCK &&
982 lock->start == plock->start &&
983 lock->size == plock->size) {
984
985 /* found it - delete it */
986 deleted_lock_type = lock->lock_type;
987 break;
988 }
989 }
990
991 if (i != br_lck->num_locks) {
992 /* We found it - don't search again. */
993 goto unlock_continue;
994 }
995 #endif
996
997 for (i = 0; i < br_lck->num_locks; i++) {
998 struct lock_struct *lock = &locks[i];
999
1000 /* Only remove our own locks that match in start, size, and flavour. */
1001 if (brl_same_context(&lock->context, &plock->context) &&
1002 lock->fnum == plock->fnum &&
1003 lock->lock_flav == WINDOWS_LOCK &&
1004 lock->start == plock->start &&
1005 lock->size == plock->size ) {
1006 deleted_lock_type = lock->lock_type;
1007 break;
1008 }
1009 }
1010
1011 if (i == br_lck->num_locks) {
1012 /* we didn't find it */
1013 return False;
1014 }
1015
1016 #if ZERO_ZERO
1017 unlock_continue:
1018 #endif
1019
1020 /* Actually delete the lock. */
1021 if (i < br_lck->num_locks - 1) {
1022 memmove(&locks[i], &locks[i+1],
1023 sizeof(*locks)*((br_lck->num_locks-1) - i));
1024 }
1025
1026 br_lck->num_locks -= 1;
1027 br_lck->modified = True;
1028
1029 /* Unlock the underlying POSIX regions. */
1030 if(lp_posix_locking(br_lck->fsp->conn->params)) {
1031 release_posix_lock_windows_flavour(br_lck->fsp,
1032 plock->start,
1033 plock->size,
1034 deleted_lock_type,
1035 &plock->context,
1036 locks,
1037 br_lck->num_locks);
1038 }
1039
1040 /* Send unlock messages to any pending waiters that overlap. */
1041 for (j=0; j < br_lck->num_locks; j++) {
1042 struct lock_struct *pend_lock = &locks[j];
1043
1044 /* Ignore non-pending locks. */
1045 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1046 continue;
1047 }
1048
1049 /* We could send specific lock info here... */
1050 if (brl_pending_overlap(plock, pend_lock)) {
1051 DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1052 procid_str_static(&pend_lock->context.pid )));
1053
1054 messaging_send(msg_ctx, pend_lock->context.pid,
1055 MSG_SMB_UNLOCK, &data_blob_null);
1056 }
1057 }
1058
1059 contend_level2_oplocks_end(br_lck->fsp, LEVEL2_CONTEND_WINDOWS_BRL);
1060 return True;
1061 }
1062
1063 /****************************************************************************
1064 Unlock a range of bytes - POSIX semantics.
1065 ****************************************************************************/
1066
1067 static bool brl_unlock_posix(struct messaging_context *msg_ctx,
1068 struct byte_range_lock *br_lck,
1069 struct lock_struct *plock)
1070 {
1071 unsigned int i, j, count;
1072 struct lock_struct *tp;
1073 struct lock_struct *locks = br_lck->lock_data;
1074 bool overlap_found = False;
1075
1076 /* No zero-zero locks for POSIX. */
1077 if (plock->start == 0 && plock->size == 0) {
1078 return False;
1079 }
1080
1081 /* Don't allow 64-bit lock wrap. */
1082 if (plock->start + plock->size < plock->start ||
1083 plock->start + plock->size < plock->size) {
1084 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
1085 return False;
1086 }
1087
1088 /* The worst case scenario here is we have to split an
1089 existing POSIX lock range into two, so we need at most
1090 1 more entry. */
1091
1092 tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 1));
1093 if (!tp) {
1094 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
1095 return False;
1096 }
1097
1098 count = 0;
1099 for (i = 0; i < br_lck->num_locks; i++) {
1100 struct lock_struct *lock = &locks[i];
1101 unsigned int tmp_count;
1102
1103 /* Only remove our own locks - ignore fnum. */
1104 if (IS_PENDING_LOCK(lock->lock_type) ||
1105 !brl_same_context(&lock->context, &plock->context)) {
1106 memcpy(&tp[count], lock, sizeof(struct lock_struct));
1107 count++;
1108 continue;
1109 }
1110
1111 if (lock->lock_flav == WINDOWS_LOCK) {
1112 /* Do any Windows flavour locks conflict ? */
1113 if (brl_conflict(lock, plock)) {
1114 SAFE_FREE(tp);
1115 return false;
1116 }
1117 /* Just copy the Windows lock into the new array. */
1118 memcpy(&tp[count], lock, sizeof(struct lock_struct));
1119 count++;
1120 continue;
1121 }
1122
1123 /* Work out overlaps. */
1124 tmp_count = brlock_posix_split_merge(&tp[count], lock, plock);
1125
1126 if (tmp_count == 0) {
1127 /* plock overlapped the existing lock completely,
1128 or replaced it. Don't copy the existing lock. */
1129 overlap_found = true;
1130 } else if (tmp_count == 1) {
1131 /* Either no overlap, (simple copy of existing lock) or
1132 * an overlap of an existing lock. */
1133 /* If the lock changed size, we had an overlap. */
1134 if (tp[count].size != lock->size) {
1135 overlap_found = true;
1136 }
1137 count += tmp_count;
1138 } else if (tmp_count == 2) {
1139 /* We split a lock range in two. */
1140 overlap_found = true;
1141 count += tmp_count;
1142
1143 /* Optimisation... */
1144 /* We know we're finished here as we can't overlap any
1145 more POSIX locks. Copy the rest of the lock array. */
1146
1147 if (i < br_lck->num_locks - 1) {
1148 memcpy(&tp[count], &locks[i+1],
1149 sizeof(*locks)*((br_lck->num_locks-1) - i));
1150 count += ((br_lck->num_locks-1) - i);
1151 }
1152 break;
1153 }
1154
1155 }
1156
1157 if (!overlap_found) {
1158 /* Just ignore - no change. */
1159 SAFE_FREE(tp);
1160 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
1161 return True;
1162 }
1163
1164 /* Unlock any POSIX regions. */
1165 if(lp_posix_locking(br_lck->fsp->conn->params)) {
1166 release_posix_lock_posix_flavour(br_lck->fsp,
1167 plock->start,
1168 plock->size,
1169 &plock->context,
1170 tp,
1171 count);
1172 }
1173
1174 /* Realloc so we don't leak entries per unlock call. */
1175 if (count) {
1176 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
1177 if (!tp) {
1178 DEBUG(10,("brl_unlock_posix: realloc fail\n"));
1179 return False;
1180 }
1181 } else {
1182 /* We deleted the last lock. */
1183 SAFE_FREE(tp);
1184 tp = NULL;
1185 }
1186
1187 contend_level2_oplocks_end(br_lck->fsp,
1188 LEVEL2_CONTEND_POSIX_BRL);
1189
1190 br_lck->num_locks = count;
1191 SAFE_FREE(br_lck->lock_data);
1192 locks = tp;
1193 br_lck->lock_data = tp;
1194 br_lck->modified = True;
1195
1196 /* Send unlock messages to any pending waiters that overlap. */
1197
1198 for (j=0; j < br_lck->num_locks; j++) {
1199 struct lock_struct *pend_lock = &locks[j];
1200
1201 /* Ignore non-pending locks. */
1202 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1203 continue;
1204 }
1205
1206 /* We could send specific lock info here... */
1207 if (brl_pending_overlap(plock, pend_lock)) {
1208 DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1209 procid_str_static(&pend_lock->context.pid )));
1210
1211 messaging_send(msg_ctx, pend_lock->context.pid,
1212 MSG_SMB_UNLOCK, &data_blob_null);
1213 }
1214 }
1215
1216 return True;
1217 }
1218
1219 bool smb_vfs_call_brl_unlock_windows(struct vfs_handle_struct *handle,
1220 struct messaging_context *msg_ctx,
1221 struct byte_range_lock *br_lck,
1222 const struct lock_struct *plock)
1223 {
1224 VFS_FIND(brl_unlock_windows);
1225 return handle->fns->brl_unlock_windows(handle, msg_ctx, br_lck, plock);
1226 }
1227
1228 /****************************************************************************
1229 Unlock a range of bytes.
1230 ****************************************************************************/
1231
1232 bool brl_unlock(struct messaging_context *msg_ctx,
1233 struct byte_range_lock *br_lck,
1234 uint32 smbpid,
1235 struct server_id pid,
1236 br_off start,
1237 br_off size,
1238 enum brl_flavour lock_flav)
1239 {
1240 struct lock_struct lock;
1241
1242 lock.context.smbpid = smbpid;
1243 lock.context.pid = pid;
1244 lock.context.tid = br_lck->fsp->conn->cnum;
1245 lock.start = start;
1246 lock.size = size;
1247 lock.fnum = br_lck->fsp->fnum;
1248 lock.lock_type = UNLOCK_LOCK;
1249 lock.lock_flav = lock_flav;
1250
1251 if (lock_flav == WINDOWS_LOCK) {
1252 return SMB_VFS_BRL_UNLOCK_WINDOWS(br_lck->fsp->conn, msg_ctx,
1253 br_lck, &lock);
1254 } else {
1255 return brl_unlock_posix(msg_ctx, br_lck, &lock);
1256 }
1257 }
1258
1259 /****************************************************************************
1260 Test if we could add a lock if we wanted to.
1261 Returns True if the region required is currently unlocked, False if locked.
1262 ****************************************************************************/
1263
1264 bool brl_locktest(struct byte_range_lock *br_lck,
1265 uint32 smbpid,
1266 struct server_id pid,
1267 br_off start,
1268 br_off size,
1269 enum brl_type lock_type,
1270 enum brl_flavour lock_flav)
1271 {
1272 bool ret = True;
1273 unsigned int i;
1274 struct lock_struct lock;
1275 const struct lock_struct *locks = br_lck->lock_data;
1276 files_struct *fsp = br_lck->fsp;
1277
1278 lock.context.smbpid = smbpid;
1279 lock.context.pid = pid;
1280 lock.context.tid = br_lck->fsp->conn->cnum;
1281 lock.start = start;
1282 lock.size = size;
1283 lock.fnum = fsp->fnum;
1284 lock.lock_type = lock_type;
1285 lock.lock_flav = lock_flav;
1286
1287 /* Make sure existing locks don't conflict */
1288 for (i=0; i < br_lck->num_locks; i++) {
1289 /*
1290 * Our own locks don't conflict.
1291 */
1292 if (brl_conflict_other(&locks[i], &lock)) {
1293 return False;
1294 }
1295 }
1296
1297 /*
1298 * There is no lock held by an SMB daemon, check to
1299 * see if there is a POSIX lock from a UNIX or NFS process.
1300 * This only conflicts with Windows locks, not POSIX locks.
1301 */
1302
1303 if(lp_posix_locking(fsp->conn->params) && (lock_flav == WINDOWS_LOCK)) {
1304 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1305
1306 DEBUG(10,("brl_locktest: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1307 (double)start, (double)size, ret ? "locked" : "unlocked",
1308 fsp->fnum, fsp_str_dbg(fsp)));
1309
1310 /* We need to return the inverse of is_posix_locked. */
1311 ret = !ret;
1312 }
1313
1314 /* no conflicts - we could have added it */
1315 return ret;
1316 }
1317
1318 /****************************************************************************
1319 Query for existing locks.
1320 ****************************************************************************/
1321
1322 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1323 uint32 *psmbpid,
1324 struct server_id pid,
1325 br_off *pstart,
1326 br_off *psize,
1327 enum brl_type *plock_type,
1328 enum brl_flavour lock_flav)
1329 {
1330 unsigned int i;
1331 struct lock_struct lock;
1332 const struct lock_struct *locks = br_lck->lock_data;
1333 files_struct *fsp = br_lck->fsp;
1334
1335 lock.context.smbpid = *psmbpid;
1336 lock.context.pid = pid;
1337 lock.context.tid = br_lck->fsp->conn->cnum;
1338 lock.start = *pstart;
1339 lock.size = *psize;
1340 lock.fnum = fsp->fnum;
1341 lock.lock_type = *plock_type;
1342 lock.lock_flav = lock_flav;
1343
1344 /* Make sure existing locks don't conflict */
1345 for (i=0; i < br_lck->num_locks; i++) {
1346 const struct lock_struct *exlock = &locks[i];
1347 bool conflict = False;
1348
1349 if (exlock->lock_flav == WINDOWS_LOCK) {
1350 conflict = brl_conflict(exlock, &lock);
1351 } else {
1352 conflict = brl_conflict_posix(exlock, &lock);
1353 }
1354
1355 if (conflict) {
1356 *psmbpid = exlock->context.smbpid;
1357 *pstart = exlock->start;
1358 *psize = exlock->size;
1359 *plock_type = exlock->lock_type;
1360 return NT_STATUS_LOCK_NOT_GRANTED;
1361 }
1362 }
1363
1364 /*
1365 * There is no lock held by an SMB daemon, check to
1366 * see if there is a POSIX lock from a UNIX or NFS process.
1367 */
1368
1369 if(lp_posix_locking(fsp->conn->params)) {
1370 bool ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1371
1372 DEBUG(10,("brl_lockquery: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1373 (double)*pstart, (double)*psize, ret ? "locked" : "unlocked",
1374 fsp->fnum, fsp_str_dbg(fsp)));
1375
1376 if (ret) {
1377 /* Hmmm. No clue what to set smbpid to - use -1. */
1378 *psmbpid = 0xFFFF;
1379 return NT_STATUS_LOCK_NOT_GRANTED;
1380 }
1381 }
1382
1383 return NT_STATUS_OK;
1384 }
1385
1386
1387 bool smb_vfs_call_brl_cancel_windows(struct vfs_handle_struct *handle,
1388 struct byte_range_lock *br_lck,
1389 struct lock_struct *plock,
1390 struct blocking_lock_record *blr)
1391 {
1392 VFS_FIND(brl_cancel_windows);
1393 return handle->fns->brl_cancel_windows(handle, br_lck, plock, blr);
1394 }
1395
1396 /****************************************************************************
1397 Remove a particular pending lock.
1398 ****************************************************************************/
1399 bool brl_lock_cancel(struct byte_range_lock *br_lck,
1400 uint32 smbpid,
1401 struct server_id pid,
1402 br_off start,
1403 br_off size,
1404 enum brl_flavour lock_flav,
1405 struct blocking_lock_record *blr)
1406 {
1407 bool ret;
1408 struct lock_struct lock;
1409
1410 lock.context.smbpid = smbpid;
1411 lock.context.pid = pid;
1412 lock.context.tid = br_lck->fsp->conn->cnum;
1413 lock.start = start;
1414 lock.size = size;
1415 lock.fnum = br_lck->fsp->fnum;
1416 lock.lock_flav = lock_flav;
1417 /* lock.lock_type doesn't matter */
1418
1419 if (lock_flav == WINDOWS_LOCK) {
1420 ret = SMB_VFS_BRL_CANCEL_WINDOWS(br_lck->fsp->conn, br_lck,
1421 &lock, blr);
1422 } else {
1423 ret = brl_lock_cancel_default(br_lck, &lock);
1424 }
1425
1426 return ret;
1427 }
1428
1429 bool brl_lock_cancel_default(struct byte_range_lock *br_lck,
1430 struct lock_struct *plock)
1431 {
1432 unsigned int i;
1433 struct lock_struct *locks = br_lck->lock_data;
1434
1435 SMB_ASSERT(plock);
1436
1437 for (i = 0; i < br_lck->num_locks; i++) {
1438 struct lock_struct *lock = &locks[i];
1439
1440 /* For pending locks we *always* care about the fnum. */
1441 if (brl_same_context(&lock->context, &plock->context) &&
1442 lock->fnum == plock->fnum &&
1443 IS_PENDING_LOCK(lock->lock_type) &&
1444 lock->lock_flav == plock->lock_flav &&
1445 lock->start == plock->start &&
1446 lock->size == plock->size) {
1447 break;
1448 }
1449 }
1450
1451 if (i == br_lck->num_locks) {
1452 /* Didn't find it. */
1453 return False;
1454 }
1455
1456 if (i < br_lck->num_locks - 1) {
1457 /* Found this particular pending lock - delete it */
1458 memmove(&locks[i], &locks[i+1],
1459 sizeof(*locks)*((br_lck->num_locks-1) - i));
1460 }
1461
1462 br_lck->num_locks -= 1;
1463 br_lck->modified = True;
1464 return True;
1465 }
1466
1467 /****************************************************************************
1468 Remove any locks associated with a open file.
1469 We return True if this process owns any other Windows locks on this
1470 fd and so we should not immediately close the fd.
1471 ****************************************************************************/
1472
1473 void brl_close_fnum(struct messaging_context *msg_ctx,
1474 struct byte_range_lock *br_lck)
1475 {
1476 files_struct *fsp = br_lck->fsp;
1477 uint16 tid = fsp->conn->cnum;
1478 int fnum = fsp->fnum;
1479 unsigned int i, j, dcount=0;
1480 int num_deleted_windows_locks = 0;
1481 struct lock_struct *locks = br_lck->lock_data;
1482 struct server_id pid = procid_self();
1483 bool unlock_individually = False;
1484 bool posix_level2_contention_ended = false;
1485
1486 if(lp_posix_locking(fsp->conn->params)) {
1487
1488 /* Check if there are any Windows locks associated with this dev/ino
1489 pair that are not this fnum. If so we need to call unlock on each
1490 one in order to release the system POSIX locks correctly. */
1491
1492 for (i=0; i < br_lck->num_locks; i++) {
1493 struct lock_struct *lock = &locks[i];
1494
1495 if (!procid_equal(&lock->context.pid, &pid)) {
1496 continue;
1497 }
1498
1499 if (lock->lock_type != READ_LOCK && lock->lock_type != WRITE_LOCK) {
1500 continue; /* Ignore pending. */
1501 }
1502
1503 if (lock->context.tid != tid || lock->fnum != fnum) {
1504 unlock_individually = True;
1505 break;
1506 }
1507 }
1508
1509 if (unlock_individually) {
1510 struct lock_struct *locks_copy;
1511 unsigned int num_locks_copy;
1512
1513 /* Copy the current lock array. */
1514 if (br_lck->num_locks) {
1515 locks_copy = (struct lock_struct *)TALLOC_MEMDUP(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1516 if (!locks_copy) {
1517 smb_panic("brl_close_fnum: talloc failed");
1518 }
1519 } else {
1520 locks_copy = NULL;
1521 }
1522
1523 num_locks_copy = br_lck->num_locks;
1524
1525 for (i=0; i < num_locks_copy; i++) {
1526 struct lock_struct *lock = &locks_copy[i];
1527
1528 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid) &&
1529 (lock->fnum == fnum)) {
1530 brl_unlock(msg_ctx,
1531 br_lck,
1532 lock->context.smbpid,
1533 pid,
1534 lock->start,
1535 lock->size,
1536 lock->lock_flav);
1537 }
1538 }
1539 return;
1540 }
1541 }
1542
1543 /* We can bulk delete - any POSIX locks will be removed when the fd closes. */
1544
1545 /* Remove any existing locks for this fnum (or any fnum if they're POSIX). */
1546
1547 for (i=0; i < br_lck->num_locks; i++) {
1548 struct lock_struct *lock = &locks[i];
1549 bool del_this_lock = False;
1550
1551 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid)) {
1552 if ((lock->lock_flav == WINDOWS_LOCK) && (lock->fnum == fnum)) {
1553 del_this_lock = True;
1554 num_deleted_windows_locks++;
1555 contend_level2_oplocks_end(br_lck->fsp,
1556 LEVEL2_CONTEND_WINDOWS_BRL);
1557 } else if (lock->lock_flav == POSIX_LOCK) {
1558 del_this_lock = True;
1559
1560 /* Only end level2 contention once for posix */
1561 if (!posix_level2_contention_ended) {
1562 posix_level2_contention_ended = true;
1563 contend_level2_oplocks_end(br_lck->fsp,
1564 LEVEL2_CONTEND_POSIX_BRL);
1565 }
1566 }
1567 }
1568
1569 if (del_this_lock) {
1570 /* Send unlock messages to any pending waiters that overlap. */
1571 for (j=0; j < br_lck->num_locks; j++) {
1572 struct lock_struct *pend_lock = &locks[j];
1573
1574 /* Ignore our own or non-pending locks. */
1575 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1576 continue;
1577 }
1578
1579 /* Optimisation - don't send to this fnum as we're
1580 closing it. */
1581 if (pend_lock->context.tid == tid &&
1582 procid_equal(&pend_lock->context.pid, &pid) &&
1583 pend_lock->fnum == fnum) {
1584 continue;
1585 }
1586
1587 /* We could send specific lock info here... */
1588 if (brl_pending_overlap(lock, pend_lock)) {
1589 messaging_send(msg_ctx, pend_lock->context.pid,
1590 MSG_SMB_UNLOCK, &data_blob_null);
1591 }
1592 }
1593
1594 /* found it - delete it */
1595 if (br_lck->num_locks > 1 && i < br_lck->num_locks - 1) {
1596 memmove(&locks[i], &locks[i+1],
1597 sizeof(*locks)*((br_lck->num_locks-1) - i));
1598 }
1599 br_lck->num_locks--;
1600 br_lck->modified = True;
1601 i--;
1602 dcount++;
1603 }
1604 }
1605
1606 if(lp_posix_locking(fsp->conn->params) && num_deleted_windows_locks) {
1607 /* Reduce the Windows lock POSIX reference count on this dev/ino pair. */
1608 reduce_windows_lock_ref_count(fsp, num_deleted_windows_locks);
1609 }
1610 }
1611
1612 /****************************************************************************
1613 Ensure this set of lock entries is valid.
1614 ****************************************************************************/
1615 static bool validate_lock_entries(unsigned int *pnum_entries, struct lock_struct **pplocks)
1616 {
1617 unsigned int i;
1618 unsigned int num_valid_entries = 0;
1619 struct lock_struct *locks = *pplocks;
1620
1621 for (i = 0; i < *pnum_entries; i++) {
1622 struct lock_struct *lock_data = &locks[i];
1623 if (!process_exists(lock_data->context.pid)) {
1624 /* This process no longer exists - mark this
1625 entry as invalid by zeroing it. */
1626 ZERO_STRUCTP(lock_data);
1627 } else {
1628 num_valid_entries++;
1629 }
1630 }
1631
1632 if (num_valid_entries != *pnum_entries) {
1633 struct lock_struct *new_lock_data = NULL;
1634
1635 if (num_valid_entries) {
1636 new_lock_data = SMB_MALLOC_ARRAY(struct lock_struct, num_valid_entries);
1637 if (!new_lock_data) {
1638 DEBUG(3, ("malloc fail\n"));
1639 return False;
1640 }
1641
1642 num_valid_entries = 0;
1643 for (i = 0; i < *pnum_entries; i++) {
1644 struct lock_struct *lock_data = &locks[i];
1645 if (lock_data->context.smbpid &&
1646 lock_data->context.tid) {
1647 /* Valid (nonzero) entry - copy it. */
1648 memcpy(&new_lock_data[num_valid_entries],
1649 lock_data, sizeof(struct lock_struct));
1650 num_valid_entries++;
1651 }
1652 }
1653 }
1654
1655 SAFE_FREE(*pplocks);
1656 *pplocks = new_lock_data;
1657 *pnum_entries = num_valid_entries;
1658 }
1659
1660 return True;
1661 }
1662
1663 struct brl_forall_cb {
1664 void (*fn)(struct file_id id, struct server_id pid,
1665 enum brl_type lock_type,
1666 enum brl_flavour lock_flav,
1667 br_off start, br_off size,
1668 void *private_data);
1669 void *private_data;
1670 };
1671
1672 /****************************************************************************
1673 Traverse the whole database with this function, calling traverse_callback
1674 on each lock.
1675 ****************************************************************************/
1676
1677 static int traverse_fn(struct db_record *rec, void *state)
1678 {
1679 struct brl_forall_cb *cb = (struct brl_forall_cb *)state;
1680 struct lock_struct *locks;
1681 struct file_id *key;
1682 unsigned int i;
1683 unsigned int num_locks = 0;
1684 unsigned int orig_num_locks = 0;
1685
1686 /* In a traverse function we must make a copy of
1687 dbuf before modifying it. */
1688
1689 locks = (struct lock_struct *)memdup(rec->value.dptr,
1690 rec->value.dsize);
1691 if (!locks) {
1692 return -1; /* Terminate traversal. */
1693 }
1694
1695 key = (struct file_id *)rec->key.dptr;
1696 orig_num_locks = num_locks = rec->value.dsize/sizeof(*locks);
1697
1698 /* Ensure the lock db is clean of entries from invalid processes. */
1699
1700 if (!validate_lock_entries(&num_locks, &locks)) {
1701 SAFE_FREE(locks);
1702 return -1; /* Terminate traversal */
1703 }
1704
1705 if (orig_num_locks != num_locks) {
1706 if (num_locks) {
1707 TDB_DATA data;
1708 data.dptr = (uint8_t *)locks;
1709 data.dsize = num_locks*sizeof(struct lock_struct);
1710 rec->store(rec, data, TDB_REPLACE);
1711 } else {
1712 rec->delete_rec(rec);
1713 }
1714 }
1715
1716 if (cb->fn) {
1717 for ( i=0; i<num_locks; i++) {
1718 cb->fn(*key,
1719 locks[i].context.pid,
1720 locks[i].lock_type,
1721 locks[i].lock_flav,
1722 locks[i].start,
1723 locks[i].size,
1724 cb->private_data);
1725 }
1726 }
1727
1728 SAFE_FREE(locks);
1729 return 0;
1730 }
1731
1732 /*******************************************************************
1733 Call the specified function on each lock in the database.
1734 ********************************************************************/
1735
1736 int brl_forall(void (*fn)(struct file_id id, struct server_id pid,
1737 enum brl_type lock_type,
1738 enum brl_flavour lock_flav,
1739 br_off start, br_off size,
1740 void *private_data),
1741 void *private_data)
1742 {
1743 struct brl_forall_cb cb;
1744
1745 if (!brlock_db) {
1746 return 0;
1747 }
1748 cb.fn = fn;
1749 cb.private_data = private_data;
1750 return brlock_db->traverse(brlock_db, traverse_fn, &cb);
1751 }
1752
1753 /*******************************************************************
1754 Store a potentially modified set of byte range lock data back into
1755 the database.
1756 Unlock the record.
1757 ********************************************************************/
1758
1759 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1760 {
1761 if (br_lck->read_only) {
1762 SMB_ASSERT(!br_lck->modified);
1763 }
1764
1765 if (!br_lck->modified) {
1766 goto done;
1767 }
1768
1769 if (br_lck->num_locks == 0) {
1770 /* No locks - delete this entry. */
1771 NTSTATUS status = br_lck->record->delete_rec(br_lck->record);
1772 if (!NT_STATUS_IS_OK(status)) {
1773 DEBUG(0, ("delete_rec returned %s\n",
1774 nt_errstr(status)));
1775 smb_panic("Could not delete byte range lock entry");
1776 }
1777 } else {
1778 TDB_DATA data;
1779 NTSTATUS status;
1780
1781 data.dptr = (uint8 *)br_lck->lock_data;
1782 data.dsize = br_lck->num_locks * sizeof(struct lock_struct);
1783
1784 status = br_lck->record->store(br_lck->record, data,
1785 TDB_REPLACE);
1786 if (!NT_STATUS_IS_OK(status)) {
1787 DEBUG(0, ("store returned %s\n", nt_errstr(status)));
1788 smb_panic("Could not store byte range mode entry");
1789 }
1790 }
1791
1792 done:
1793
1794 SAFE_FREE(br_lck->lock_data);
1795 TALLOC_FREE(br_lck->record);
1796 return 0;
1797 }
1798
1799 /*******************************************************************
1800 Fetch a set of byte range lock data from the database.
1801 Leave the record locked.
1802 TALLOC_FREE(brl) will release the lock in the destructor.
1803 ********************************************************************/
1804
1805 static struct byte_range_lock *brl_get_locks_internal(TALLOC_CTX *mem_ctx,
1806 files_struct *fsp, bool read_only)
1807 {
1808 TDB_DATA key, data;
1809 struct byte_range_lock *br_lck = TALLOC_P(mem_ctx, struct byte_range_lock);
1810
1811 if (br_lck == NULL) {
1812 return NULL;
1813 }
1814
1815 br_lck->fsp = fsp;
1816 br_lck->num_locks = 0;
1817 br_lck->modified = False;
1818 br_lck->key = fsp->file_id;
1819
1820 key.dptr = (uint8 *)&br_lck->key;
1821 key.dsize = sizeof(struct file_id);
1822
1823 if (!fsp->lockdb_clean) {
1824 /* We must be read/write to clean
1825 the dead entries. */
1826 read_only = False;
1827 }
1828
1829 if (read_only) {
1830 if (brlock_db->fetch(brlock_db, br_lck, key, &data) == -1) {
1831 DEBUG(3, ("Could not fetch byte range lock record\n"));
1832 TALLOC_FREE(br_lck);
1833 return NULL;
1834 }
1835 br_lck->record = NULL;
1836 }
1837 else {
1838 br_lck->record = brlock_db->fetch_locked(brlock_db, br_lck, key);
1839
1840 if (br_lck->record == NULL) {
1841 DEBUG(3, ("Could not lock byte range lock entry\n"));
1842 TALLOC_FREE(br_lck);
1843 return NULL;
1844 }
1845
1846 data = br_lck->record->value;
1847 }
1848
1849 br_lck->read_only = read_only;
1850 br_lck->lock_data = NULL;
1851
1852 talloc_set_destructor(br_lck, byte_range_lock_destructor);
1853
1854 br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1855
1856 if (br_lck->num_locks != 0) {
1857 br_lck->lock_data = SMB_MALLOC_ARRAY(struct lock_struct,
1858 br_lck->num_locks);
1859 if (br_lck->lock_data == NULL) {
1860 DEBUG(0, ("malloc failed\n"));
1861 TALLOC_FREE(br_lck);
1862 return NULL;
1863 }
1864
1865 memcpy(br_lck->lock_data, data.dptr, data.dsize);
1866 }
1867
1868 if (!fsp->lockdb_clean) {
1869 int orig_num_locks = br_lck->num_locks;
1870
1871 /* This is the first time we've accessed this. */
1872 /* Go through and ensure all entries exist - remove any that don't. */
1873 /* Makes the lockdb self cleaning at low cost. */
1874
1875 if (!validate_lock_entries(&br_lck->num_locks,
1876 &br_lck->lock_data)) {
1877 SAFE_FREE(br_lck->lock_data);
1878 TALLOC_FREE(br_lck);
1879 return NULL;
1880 }
1881
1882 /* Ensure invalid locks are cleaned up in the destructor. */
1883 if (orig_num_locks != br_lck->num_locks) {
1884 br_lck->modified = True;
1885 }
1886
1887 /* Mark the lockdb as "clean" as seen from this open file. */
1888 fsp->lockdb_clean = True;
1889 }
1890
1891 if (DEBUGLEVEL >= 10) {
1892 unsigned int i;
1893 struct lock_struct *locks = br_lck->lock_data;
1894 DEBUG(10,("brl_get_locks_internal: %u current locks on file_id %s\n",
1895 br_lck->num_locks,
1896 file_id_string_tos(&fsp->file_id)));
1897 for( i = 0; i < br_lck->num_locks; i++) {
1898 print_lock_struct(i, &locks[i]);
1899 }
1900 }
1901 return br_lck;
1902 }
1903
1904 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
1905 files_struct *fsp)
1906 {
1907 return brl_get_locks_internal(mem_ctx, fsp, False);
1908 }
1909
1910 struct byte_range_lock *brl_get_locks_readonly(files_struct *fsp)
1911 {
1912 struct byte_range_lock *br_lock;
1913
1914 if (lp_clustering()) {
1915 return brl_get_locks_internal(talloc_tos(), fsp, true);
1916 }
1917
1918 if ((fsp->brlock_rec != NULL)
1919 && (brlock_db->get_seqnum(brlock_db) == fsp->brlock_seqnum)) {
1920 return fsp->brlock_rec;
1921 }
1922
1923 TALLOC_FREE(fsp->brlock_rec);
1924
1925 br_lock = brl_get_locks_internal(talloc_tos(), fsp, false);
1926 if (br_lock == NULL) {
1927 return NULL;
1928 }
1929 fsp->brlock_seqnum = brlock_db->get_seqnum(brlock_db);
1930
1931 fsp->brlock_rec = talloc_zero(fsp, struct byte_range_lock);
1932 if (fsp->brlock_rec == NULL) {
1933 goto fail;
1934 }
1935 fsp->brlock_rec->fsp = fsp;
1936 fsp->brlock_rec->num_locks = br_lock->num_locks;
1937 fsp->brlock_rec->read_only = true;
1938 fsp->brlock_rec->key = br_lock->key;
1939
1940 fsp->brlock_rec->lock_data = (struct lock_struct *)
1941 talloc_memdup(fsp->brlock_rec, br_lock->lock_data,
1942 sizeof(struct lock_struct) * br_lock->num_locks);
1943 if (fsp->brlock_rec->lock_data == NULL) {
1944 goto fail;
1945 }
1946
1947 TALLOC_FREE(br_lock);
1948 return fsp->brlock_rec;
1949 fail:
1950 TALLOC_FREE(br_lock);
1951 TALLOC_FREE(fsp->brlock_rec);
1952 return NULL;
1953 }
1954
1955 struct brl_revalidate_state {
1956 ssize_t array_size;
1957 uint32 num_pids;
1958 struct server_id *pids;
1959 };
1960
1961 /*
1962 * Collect PIDs of all processes with pending entries
1963 */
1964
1965 static void brl_revalidate_collect(struct file_id id, struct server_id pid,
1966 enum brl_type lock_type,
1967 enum brl_flavour lock_flav,
1968 br_off start, br_off size,
1969 void *private_data)
1970 {
1971 struct brl_revalidate_state *state =
1972 (struct brl_revalidate_state *)private_data;
1973
1974 if (!IS_PENDING_LOCK(lock_type)) {
1975 return;
1976 }
1977
1978 add_to_large_array(state, sizeof(pid), (void *)&pid,
1979 &state->pids, &state->num_pids,
1980 &state->array_size);
1981 }
1982
1983 /*
1984 * qsort callback to sort the processes
1985 */
1986
1987 static int compare_procids(const void *p1, const void *p2)
1988 {
1989 const struct server_id *i1 = (struct server_id *)p1;
1990 const struct server_id *i2 = (struct server_id *)p2;
1991
1992 if (i1->pid < i2->pid) return -1;
1993 if (i2->pid > i2->pid) return 1;
1994 return 0;
1995 }
1996
1997 /*
1998 * Send a MSG_SMB_UNLOCK message to all processes with pending byte range
1999 * locks so that they retry. Mainly used in the cluster code after a node has
2000 * died.
2001 *
2002 * Done in two steps to avoid double-sends: First we collect all entries in an
2003 * array, then qsort that array and only send to non-dupes.
2004 */
2005
2006 static void brl_revalidate(struct messaging_context *msg_ctx,
2007 void *private_data,
2008 uint32_t msg_type,
2009 struct server_id server_id,
2010 DATA_BLOB *data)
2011 {
2012 struct brl_revalidate_state *state;
2013 uint32 i;
2014 struct server_id last_pid;
2015
2016 if (!(state = TALLOC_ZERO_P(NULL, struct brl_revalidate_state))) {
2017 DEBUG(0, ("talloc failed\n"));
2018 return;
2019 }
2020
2021 brl_forall(brl_revalidate_collect, state);
2022
2023 if (state->array_size == -1) {
2024 DEBUG(0, ("talloc failed\n"));
2025 goto done;
2026 }
2027
2028 if (state->num_pids == 0) {
2029 goto done;
2030 }
2031
2032 qsort(state->pids, state->num_pids, sizeof(state->pids[0]),
2033 compare_procids);
2034
2035 ZERO_STRUCT(last_pid);
2036
2037 for (i=0; i<state->num_pids; i++) {
2038 if (procid_equal(&last_pid, &state->pids[i])) {
2039 /*
2040 * We've seen that one already
2041 */
2042 continue;
2043 }
2044
2045 messaging_send(msg_ctx, state->pids[i], MSG_SMB_UNLOCK,
2046 &data_blob_null);
2047 last_pid = state->pids[i];
2048 }
2049
2050 done:
2051 TALLOC_FREE(state);
2052 return;
2053 }
2054
2055 void brl_register_msgs(struct messaging_context *msg_ctx)
2056 {
2057 messaging_register(msg_ctx, NULL, MSG_SMB_BRL_VALIDATE,
2058 brl_revalidate);
2059 }
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