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s3-net: Make sure that the data blob is initialized.
[Samba/gebeck_regimport.git] / source3 / locking / brlock.c
blob985b98a468b30e959ba575a31722ef10fab7b5e8
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 #include "librpc/gen_ndr/messaging.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 struct db_context *brlock_db;
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]: smblctx = %llu, tid = %u, pid = %s, ",
46 i,
47 (unsigned long long)pls->context.smblctx,
48 (unsigned int)pls->context.tid,
49 procid_str(talloc_tos(), &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->smblctx == ctx2->smblctx) &&
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 /* XXX Remove for Win7 compatibility. */
79 /* this extra check is not redundent - it copes with locks
80 that go beyond the end of 64 bit file space */
81 if (lck1->size != 0 &&
82 lck1->start == lck2->start &&
83 lck1->size == lck2->size) {
84 return True;
85 }
86
87 if (lck1->start >= (lck2->start+lck2->size) ||
88 lck2->start >= (lck1->start+lck1->size)) {
89 return False;
90 }
91 return True;
92 }
93
94 /****************************************************************************
95 See if lock2 can be added when lock1 is in place.
96 ****************************************************************************/
97
98 static bool brl_conflict(const struct lock_struct *lck1,
99 const struct lock_struct *lck2)
100 {
101 /* Ignore PENDING locks. */
102 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
103 return False;
104
105 /* Read locks never conflict. */
106 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
107 return False;
108 }
109
110 /* A READ lock can stack on top of a WRITE lock if they have the same
111 * context & fnum. */
112 if (lck1->lock_type == WRITE_LOCK && lck2->lock_type == READ_LOCK &&
113 brl_same_context(&lck1->context, &lck2->context) &&
114 lck1->fnum == lck2->fnum) {
115 return False;
116 }
117
118 return brl_overlap(lck1, lck2);
119 }
120
121 /****************************************************************************
122 See if lock2 can be added when lock1 is in place - when both locks are POSIX
123 flavour. POSIX locks ignore fnum - they only care about dev/ino which we
124 know already match.
125 ****************************************************************************/
126
127 static bool brl_conflict_posix(const struct lock_struct *lck1,
128 const struct lock_struct *lck2)
129 {
130 #if defined(DEVELOPER)
131 SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
132 SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
133 #endif
134
135 /* Ignore PENDING locks. */
136 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
137 return False;
138
139 /* Read locks never conflict. */
140 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
141 return False;
142 }
143
144 /* Locks on the same context con't conflict. Ignore fnum. */
145 if (brl_same_context(&lck1->context, &lck2->context)) {
146 return False;
147 }
148
149 /* One is read, the other write, or the context is different,
150 do they overlap ? */
151 return brl_overlap(lck1, lck2);
152 }
153
154 #if ZERO_ZERO
155 static bool brl_conflict1(const struct lock_struct *lck1,
156 const struct lock_struct *lck2)
157 {
158 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
159 return False;
160
161 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
162 return False;
163 }
164
165 if (brl_same_context(&lck1->context, &lck2->context) &&
166 lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
167 return False;
168 }
169
170 if (lck2->start == 0 && lck2->size == 0 && lck1->size != 0) {
171 return True;
172 }
173
174 if (lck1->start >= (lck2->start + lck2->size) ||
175 lck2->start >= (lck1->start + lck1->size)) {
176 return False;
177 }
178
179 return True;
180 }
181 #endif
182
183 /****************************************************************************
184 Check to see if this lock conflicts, but ignore our own locks on the
185 same fnum only. This is the read/write lock check code path.
186 This is never used in the POSIX lock case.
187 ****************************************************************************/
188
189 static bool brl_conflict_other(const struct lock_struct *lck1, const struct lock_struct *lck2)
190 {
191 if (IS_PENDING_LOCK(lck1->lock_type) || IS_PENDING_LOCK(lck2->lock_type))
192 return False;
193
194 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
195 return False;
196
197 /* POSIX flavour locks never conflict here - this is only called
198 in the read/write path. */
199
200 if (lck1->lock_flav == POSIX_LOCK && lck2->lock_flav == POSIX_LOCK)
201 return False;
202
203 /*
204 * Incoming WRITE locks conflict with existing READ locks even
205 * if the context is the same. JRA. See LOCKTEST7 in smbtorture.
206 */
207
208 if (!(lck2->lock_type == WRITE_LOCK && lck1->lock_type == READ_LOCK)) {
209 if (brl_same_context(&lck1->context, &lck2->context) &&
210 lck1->fnum == lck2->fnum)
211 return False;
212 }
213
214 return brl_overlap(lck1, lck2);
215 }
216
217 /****************************************************************************
218 Check if an unlock overlaps a pending lock.
219 ****************************************************************************/
220
221 static bool brl_pending_overlap(const struct lock_struct *lock, const struct lock_struct *pend_lock)
222 {
223 if ((lock->start <= pend_lock->start) && (lock->start + lock->size > pend_lock->start))
224 return True;
225 if ((lock->start >= pend_lock->start) && (lock->start <= pend_lock->start + pend_lock->size))
226 return True;
227 return False;
228 }
229
230 /****************************************************************************
231 Amazingly enough, w2k3 "remembers" whether the last lock failure on a fnum
232 is the same as this one and changes its error code. I wonder if any
233 app depends on this ?
234 ****************************************************************************/
235
236 NTSTATUS brl_lock_failed(files_struct *fsp, const struct lock_struct *lock, bool blocking_lock)
237 {
238 if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
239 /* amazing the little things you learn with a test
240 suite. Locks beyond this offset (as a 64 bit
241 number!) always generate the conflict error code,
242 unless the top bit is set */
243 if (!blocking_lock) {
244 fsp->last_lock_failure = *lock;
245 }
246 return NT_STATUS_FILE_LOCK_CONFLICT;
247 }
248
249 if (procid_equal(&lock->context.pid, &fsp->last_lock_failure.context.pid) &&
250 lock->context.tid == fsp->last_lock_failure.context.tid &&
251 lock->fnum == fsp->last_lock_failure.fnum &&
252 lock->start == fsp->last_lock_failure.start) {
253 return NT_STATUS_FILE_LOCK_CONFLICT;
254 }
255
256 if (!blocking_lock) {
257 fsp->last_lock_failure = *lock;
258 }
259 return NT_STATUS_LOCK_NOT_GRANTED;
260 }
261
262 /****************************************************************************
263 Open up the brlock.tdb database.
264 ****************************************************************************/
265
266 void brl_init(bool read_only)
267 {
268 int tdb_flags;
269
270 if (brlock_db) {
271 return;
272 }
273
274 tdb_flags = TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST;
275
276 if (!lp_clustering()) {
277 /*
278 * We can't use the SEQNUM trick to cache brlock
279 * entries in the clustering case because ctdb seqnum
280 * propagation has a delay.
281 */
282 tdb_flags |= TDB_SEQNUM;
283 }
284
285 brlock_db = db_open(NULL, lock_path("brlock.tdb"),
286 lp_open_files_db_hash_size(), tdb_flags,
287 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644 );
288 if (!brlock_db) {
289 DEBUG(0,("Failed to open byte range locking database %s\n",
290 lock_path("brlock.tdb")));
291 return;
292 }
293 }
294
295 /****************************************************************************
296 Close down the brlock.tdb database.
297 ****************************************************************************/
298
299 void brl_shutdown(void)
300 {
301 TALLOC_FREE(brlock_db);
302 }
303
304 #if ZERO_ZERO
305 /****************************************************************************
306 Compare two locks for sorting.
307 ****************************************************************************/
308
309 static int lock_compare(const struct lock_struct *lck1,
310 const struct lock_struct *lck2)
311 {
312 if (lck1->start != lck2->start) {
313 return (lck1->start - lck2->start);
314 }
315 if (lck2->size != lck1->size) {
316 return ((int)lck1->size - (int)lck2->size);
317 }
318 return 0;
319 }
320 #endif
321
322 /****************************************************************************
323 Lock a range of bytes - Windows lock semantics.
324 ****************************************************************************/
325
326 NTSTATUS brl_lock_windows_default(struct byte_range_lock *br_lck,
327 struct lock_struct *plock, bool blocking_lock)
328 {
329 unsigned int i;
330 files_struct *fsp = br_lck->fsp;
331 struct lock_struct *locks = br_lck->lock_data;
332 NTSTATUS status;
333
334 SMB_ASSERT(plock->lock_type != UNLOCK_LOCK);
335
336 if ((plock->start + plock->size - 1 < plock->start) &&
337 plock->size != 0) {
338 return NT_STATUS_INVALID_LOCK_RANGE;
339 }
340
341 for (i=0; i < br_lck->num_locks; i++) {
342 /* Do any Windows or POSIX locks conflict ? */
343 if (brl_conflict(&locks[i], plock)) {
344 /* Remember who blocked us. */
345 plock->context.smblctx = locks[i].context.smblctx;
346 return brl_lock_failed(fsp,plock,blocking_lock);
347 }
348 #if ZERO_ZERO
349 if (plock->start == 0 && plock->size == 0 &&
350 locks[i].size == 0) {
351 break;
352 }
353 #endif
354 }
355
356 if (!IS_PENDING_LOCK(plock->lock_type)) {
357 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
358 }
359
360 /* We can get the Windows lock, now see if it needs to
361 be mapped into a lower level POSIX one, and if so can
362 we get it ? */
363
364 if (!IS_PENDING_LOCK(plock->lock_type) && lp_posix_locking(fsp->conn->params)) {
365 int errno_ret;
366 if (!set_posix_lock_windows_flavour(fsp,
367 plock->start,
368 plock->size,
369 plock->lock_type,
370 &plock->context,
371 locks,
372 br_lck->num_locks,
373 &errno_ret)) {
374
375 /* We don't know who blocked us. */
376 plock->context.smblctx = 0xFFFFFFFFFFFFFFFFLL;
377
378 if (errno_ret == EACCES || errno_ret == EAGAIN) {
379 status = NT_STATUS_FILE_LOCK_CONFLICT;
380 goto fail;
381 } else {
382 status = map_nt_error_from_unix(errno);
383 goto fail;
384 }
385 }
386 }
387
388 /* no conflicts - add it to the list of locks */
389 locks = (struct lock_struct *)SMB_REALLOC(locks, (br_lck->num_locks + 1) * sizeof(*locks));
390 if (!locks) {
391 status = NT_STATUS_NO_MEMORY;
392 goto fail;
393 }
394
395 memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
396 br_lck->num_locks += 1;
397 br_lck->lock_data = locks;
398 br_lck->modified = True;
399
400 return NT_STATUS_OK;
401 fail:
402 if (!IS_PENDING_LOCK(plock->lock_type)) {
403 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
404 }
405 return status;
406 }
407
408 /****************************************************************************
409 Cope with POSIX range splits and merges.
410 ****************************************************************************/
411
412 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr, /* Output array. */
413 struct lock_struct *ex, /* existing lock. */
414 struct lock_struct *plock) /* proposed lock. */
415 {
416 bool lock_types_differ = (ex->lock_type != plock->lock_type);
417
418 /* We can't merge non-conflicting locks on different context - ignore fnum. */
419
420 if (!brl_same_context(&ex->context, &plock->context)) {
421 /* Just copy. */
422 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
423 return 1;
424 }
425
426 /* We now know we have the same context. */
427
428 /* Did we overlap ? */
429
430 /*********************************************
431 +---------+
432 | ex |
433 +---------+
434 +-------+
435 | plock |
436 +-------+
437 OR....
438 +---------+
439 | ex |
440 +---------+
441 **********************************************/
442
443 if ( (ex->start > (plock->start + plock->size)) ||
444 (plock->start > (ex->start + ex->size))) {
445
446 /* No overlap with this lock - copy existing. */
447
448 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
449 return 1;
450 }
451
452 /*********************************************
453 +---------------------------+
454 | ex |
455 +---------------------------+
456 +---------------------------+
457 | plock | -> replace with plock.
458 +---------------------------+
459 OR
460 +---------------+
461 | ex |
462 +---------------+
463 +---------------------------+
464 | plock | -> replace with plock.
465 +---------------------------+
466
467 **********************************************/
468
469 if ( (ex->start >= plock->start) &&
470 (ex->start + ex->size <= plock->start + plock->size) ) {
471
472 /* Replace - discard existing lock. */
473
474 return 0;
475 }
476
477 /*********************************************
478 Adjacent after.
479 +-------+
480 | ex |
481 +-------+
482 +---------------+
483 | plock |
484 +---------------+
485
486 BECOMES....
487 +---------------+-------+
488 | plock | ex | - different lock types.
489 +---------------+-------+
490 OR.... (merge)
491 +-----------------------+
492 | plock | - same lock type.
493 +-----------------------+
494 **********************************************/
495
496 if (plock->start + plock->size == ex->start) {
497
498 /* If the lock types are the same, we merge, if different, we
499 add the remainder of the old lock. */
500
501 if (lock_types_differ) {
502 /* Add existing. */
503 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
504 return 1;
505 } else {
506 /* Merge - adjust incoming lock as we may have more
507 * merging to come. */
508 plock->size += ex->size;
509 return 0;
510 }
511 }
512
513 /*********************************************
514 Adjacent before.
515 +-------+
516 | ex |
517 +-------+
518 +---------------+
519 | plock |
520 +---------------+
521 BECOMES....
522 +-------+---------------+
523 | ex | plock | - different lock types
524 +-------+---------------+
525
526 OR.... (merge)
527 +-----------------------+
528 | plock | - same lock type.
529 +-----------------------+
530
531 **********************************************/
532
533 if (ex->start + ex->size == plock->start) {
534
535 /* If the lock types are the same, we merge, if different, we
536 add the existing lock. */
537
538 if (lock_types_differ) {
539 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
540 return 1;
541 } else {
542 /* Merge - adjust incoming lock as we may have more
543 * merging to come. */
544 plock->start = ex->start;
545 plock->size += ex->size;
546 return 0;
547 }
548 }
549
550 /*********************************************
551 Overlap after.
552 +-----------------------+
553 | ex |
554 +-----------------------+
555 +---------------+
556 | plock |
557 +---------------+
558 OR
559 +----------------+
560 | ex |
561 +----------------+
562 +---------------+
563 | plock |
564 +---------------+
565
566 BECOMES....
567 +---------------+-------+
568 | plock | ex | - different lock types.
569 +---------------+-------+
570 OR.... (merge)
571 +-----------------------+
572 | plock | - same lock type.
573 +-----------------------+
574 **********************************************/
575
576 if ( (ex->start >= plock->start) &&
577 (ex->start <= plock->start + plock->size) &&
578 (ex->start + ex->size > plock->start + plock->size) ) {
579
580 /* If the lock types are the same, we merge, if different, we
581 add the remainder of the old lock. */
582
583 if (lock_types_differ) {
584 /* Add remaining existing. */
585 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
586 /* Adjust existing start and size. */
587 lck_arr[0].start = plock->start + plock->size;
588 lck_arr[0].size = (ex->start + ex->size) - (plock->start + plock->size);
589 return 1;
590 } else {
591 /* Merge - adjust incoming lock as we may have more
592 * merging to come. */
593 plock->size += (ex->start + ex->size) - (plock->start + plock->size);
594 return 0;
595 }
596 }
597
598 /*********************************************
599 Overlap before.
600 +-----------------------+
601 | ex |
602 +-----------------------+
603 +---------------+
604 | plock |
605 +---------------+
606 OR
607 +-------------+
608 | ex |
609 +-------------+
610 +---------------+
611 | plock |
612 +---------------+
613
614 BECOMES....
615 +-------+---------------+
616 | ex | plock | - different lock types
617 +-------+---------------+
618
619 OR.... (merge)
620 +-----------------------+
621 | plock | - same lock type.
622 +-----------------------+
623
624 **********************************************/
625
626 if ( (ex->start < plock->start) &&
627 (ex->start + ex->size >= plock->start) &&
628 (ex->start + ex->size <= plock->start + plock->size) ) {
629
630 /* If the lock types are the same, we merge, if different, we
631 add the truncated old lock. */
632
633 if (lock_types_differ) {
634 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
635 /* Adjust existing size. */
636 lck_arr[0].size = plock->start - ex->start;
637 return 1;
638 } else {
639 /* Merge - adjust incoming lock as we may have more
640 * merging to come. MUST ADJUST plock SIZE FIRST ! */
641 plock->size += (plock->start - ex->start);
642 plock->start = ex->start;
643 return 0;
644 }
645 }
646
647 /*********************************************
648 Complete overlap.
649 +---------------------------+
650 | ex |
651 +---------------------------+
652 +---------+
653 | plock |
654 +---------+
655 BECOMES.....
656 +-------+---------+---------+
657 | ex | plock | ex | - different lock types.
658 +-------+---------+---------+
659 OR
660 +---------------------------+
661 | plock | - same lock type.
662 +---------------------------+
663 **********************************************/
664
665 if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
666
667 if (lock_types_differ) {
668
669 /* We have to split ex into two locks here. */
670
671 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
672 memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
673
674 /* Adjust first existing size. */
675 lck_arr[0].size = plock->start - ex->start;
676
677 /* Adjust second existing start and size. */
678 lck_arr[1].start = plock->start + plock->size;
679 lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
680 return 2;
681 } else {
682 /* Just eat the existing locks, merge them into plock. */
683 plock->start = ex->start;
684 plock->size = ex->size;
685 return 0;
686 }
687 }
688
689 /* Never get here. */
690 smb_panic("brlock_posix_split_merge");
691 /* Notreached. */
692
693 /* Keep some compilers happy. */
694 return 0;
695 }
696
697 /****************************************************************************
698 Lock a range of bytes - POSIX lock semantics.
699 We must cope with range splits and merges.
700 ****************************************************************************/
701
702 static NTSTATUS brl_lock_posix(struct messaging_context *msg_ctx,
703 struct byte_range_lock *br_lck,
704 struct lock_struct *plock)
705 {
706 unsigned int i, count, posix_count;
707 struct lock_struct *locks = br_lck->lock_data;
708 struct lock_struct *tp;
709 bool signal_pending_read = False;
710 bool break_oplocks = false;
711 NTSTATUS status;
712
713 /* No zero-zero locks for POSIX. */
714 if (plock->start == 0 && plock->size == 0) {
715 return NT_STATUS_INVALID_PARAMETER;
716 }
717
718 /* Don't allow 64-bit lock wrap. */
719 if (plock->start + plock->size - 1 < plock->start) {
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.smblctx = curr_lock->context.smblctx;
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.smblctx = curr_lock->context.smblctx;
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.smblctx = 0xFFFFFFFFFFFFFFFFLL;
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 uint64_t smblctx,
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 uint64_t *psmblctx,
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.smblctx = smblctx;
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 TYPESAFE_QSORT(br_lck->lock_data, (size_t)br_lck->num_locks, lock_compare);
948 #endif
949
950 /* If we're returning an error, return who blocked us. */
951 if (!NT_STATUS_IS_OK(ret) && psmblctx) {
952 *psmblctx = lock.context.smblctx;
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 if (IS_PENDING_LOCK(lock->lock_type)) {
1001 continue;
1002 }
1003
1004 /* Only remove our own locks that match in start, size, and flavour. */
1005 if (brl_same_context(&lock->context, &plock->context) &&
1006 lock->fnum == plock->fnum &&
1007 lock->lock_flav == WINDOWS_LOCK &&
1008 lock->start == plock->start &&
1009 lock->size == plock->size ) {
1010 deleted_lock_type = lock->lock_type;
1011 break;
1012 }
1013 }
1014
1015 if (i == br_lck->num_locks) {
1016 /* we didn't find it */
1017 return False;
1018 }
1019
1020 #if ZERO_ZERO
1021 unlock_continue:
1022 #endif
1023
1024 /* Actually delete the lock. */
1025 if (i < br_lck->num_locks - 1) {
1026 memmove(&locks[i], &locks[i+1],
1027 sizeof(*locks)*((br_lck->num_locks-1) - i));
1028 }
1029
1030 br_lck->num_locks -= 1;
1031 br_lck->modified = True;
1032
1033 /* Unlock the underlying POSIX regions. */
1034 if(lp_posix_locking(br_lck->fsp->conn->params)) {
1035 release_posix_lock_windows_flavour(br_lck->fsp,
1036 plock->start,
1037 plock->size,
1038 deleted_lock_type,
1039 &plock->context,
1040 locks,
1041 br_lck->num_locks);
1042 }
1043
1044 /* Send unlock messages to any pending waiters that overlap. */
1045 for (j=0; j < br_lck->num_locks; j++) {
1046 struct lock_struct *pend_lock = &locks[j];
1047
1048 /* Ignore non-pending locks. */
1049 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1050 continue;
1051 }
1052
1053 /* We could send specific lock info here... */
1054 if (brl_pending_overlap(plock, pend_lock)) {
1055 DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1056 procid_str_static(&pend_lock->context.pid )));
1057
1058 messaging_send(msg_ctx, pend_lock->context.pid,
1059 MSG_SMB_UNLOCK, &data_blob_null);
1060 }
1061 }
1062
1063 contend_level2_oplocks_end(br_lck->fsp, LEVEL2_CONTEND_WINDOWS_BRL);
1064 return True;
1065 }
1066
1067 /****************************************************************************
1068 Unlock a range of bytes - POSIX semantics.
1069 ****************************************************************************/
1070
1071 static bool brl_unlock_posix(struct messaging_context *msg_ctx,
1072 struct byte_range_lock *br_lck,
1073 struct lock_struct *plock)
1074 {
1075 unsigned int i, j, count;
1076 struct lock_struct *tp;
1077 struct lock_struct *locks = br_lck->lock_data;
1078 bool overlap_found = False;
1079
1080 /* No zero-zero locks for POSIX. */
1081 if (plock->start == 0 && plock->size == 0) {
1082 return False;
1083 }
1084
1085 /* Don't allow 64-bit lock wrap. */
1086 if (plock->start + plock->size < plock->start ||
1087 plock->start + plock->size < plock->size) {
1088 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
1089 return False;
1090 }
1091
1092 /* The worst case scenario here is we have to split an
1093 existing POSIX lock range into two, so we need at most
1094 1 more entry. */
1095
1096 tp = SMB_MALLOC_ARRAY(struct lock_struct, (br_lck->num_locks + 1));
1097 if (!tp) {
1098 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
1099 return False;
1100 }
1101
1102 count = 0;
1103 for (i = 0; i < br_lck->num_locks; i++) {
1104 struct lock_struct *lock = &locks[i];
1105 unsigned int tmp_count;
1106
1107 /* Only remove our own locks - ignore fnum. */
1108 if (IS_PENDING_LOCK(lock->lock_type) ||
1109 !brl_same_context(&lock->context, &plock->context)) {
1110 memcpy(&tp[count], lock, sizeof(struct lock_struct));
1111 count++;
1112 continue;
1113 }
1114
1115 if (lock->lock_flav == WINDOWS_LOCK) {
1116 /* Do any Windows flavour locks conflict ? */
1117 if (brl_conflict(lock, plock)) {
1118 SAFE_FREE(tp);
1119 return false;
1120 }
1121 /* Just copy the Windows lock into the new array. */
1122 memcpy(&tp[count], lock, sizeof(struct lock_struct));
1123 count++;
1124 continue;
1125 }
1126
1127 /* Work out overlaps. */
1128 tmp_count = brlock_posix_split_merge(&tp[count], lock, plock);
1129
1130 if (tmp_count == 0) {
1131 /* plock overlapped the existing lock completely,
1132 or replaced it. Don't copy the existing lock. */
1133 overlap_found = true;
1134 } else if (tmp_count == 1) {
1135 /* Either no overlap, (simple copy of existing lock) or
1136 * an overlap of an existing lock. */
1137 /* If the lock changed size, we had an overlap. */
1138 if (tp[count].size != lock->size) {
1139 overlap_found = true;
1140 }
1141 count += tmp_count;
1142 } else if (tmp_count == 2) {
1143 /* We split a lock range in two. */
1144 overlap_found = true;
1145 count += tmp_count;
1146
1147 /* Optimisation... */
1148 /* We know we're finished here as we can't overlap any
1149 more POSIX locks. Copy the rest of the lock array. */
1150
1151 if (i < br_lck->num_locks - 1) {
1152 memcpy(&tp[count], &locks[i+1],
1153 sizeof(*locks)*((br_lck->num_locks-1) - i));
1154 count += ((br_lck->num_locks-1) - i);
1155 }
1156 break;
1157 }
1158
1159 }
1160
1161 if (!overlap_found) {
1162 /* Just ignore - no change. */
1163 SAFE_FREE(tp);
1164 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
1165 return True;
1166 }
1167
1168 /* Unlock any POSIX regions. */
1169 if(lp_posix_locking(br_lck->fsp->conn->params)) {
1170 release_posix_lock_posix_flavour(br_lck->fsp,
1171 plock->start,
1172 plock->size,
1173 &plock->context,
1174 tp,
1175 count);
1176 }
1177
1178 /* Realloc so we don't leak entries per unlock call. */
1179 if (count) {
1180 tp = (struct lock_struct *)SMB_REALLOC(tp, count * sizeof(*locks));
1181 if (!tp) {
1182 DEBUG(10,("brl_unlock_posix: realloc fail\n"));
1183 return False;
1184 }
1185 } else {
1186 /* We deleted the last lock. */
1187 SAFE_FREE(tp);
1188 tp = NULL;
1189 }
1190
1191 contend_level2_oplocks_end(br_lck->fsp,
1192 LEVEL2_CONTEND_POSIX_BRL);
1193
1194 br_lck->num_locks = count;
1195 SAFE_FREE(br_lck->lock_data);
1196 locks = tp;
1197 br_lck->lock_data = tp;
1198 br_lck->modified = True;
1199
1200 /* Send unlock messages to any pending waiters that overlap. */
1201
1202 for (j=0; j < br_lck->num_locks; j++) {
1203 struct lock_struct *pend_lock = &locks[j];
1204
1205 /* Ignore non-pending locks. */
1206 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1207 continue;
1208 }
1209
1210 /* We could send specific lock info here... */
1211 if (brl_pending_overlap(plock, pend_lock)) {
1212 DEBUG(10,("brl_unlock: sending unlock message to pid %s\n",
1213 procid_str_static(&pend_lock->context.pid )));
1214
1215 messaging_send(msg_ctx, pend_lock->context.pid,
1216 MSG_SMB_UNLOCK, &data_blob_null);
1217 }
1218 }
1219
1220 return True;
1221 }
1222
1223 bool smb_vfs_call_brl_unlock_windows(struct vfs_handle_struct *handle,
1224 struct messaging_context *msg_ctx,
1225 struct byte_range_lock *br_lck,
1226 const struct lock_struct *plock)
1227 {
1228 VFS_FIND(brl_unlock_windows);
1229 return handle->fns->brl_unlock_windows(handle, msg_ctx, br_lck, plock);
1230 }
1231
1232 /****************************************************************************
1233 Unlock a range of bytes.
1234 ****************************************************************************/
1235
1236 bool brl_unlock(struct messaging_context *msg_ctx,
1237 struct byte_range_lock *br_lck,
1238 uint64_t smblctx,
1239 struct server_id pid,
1240 br_off start,
1241 br_off size,
1242 enum brl_flavour lock_flav)
1243 {
1244 struct lock_struct lock;
1245
1246 lock.context.smblctx = smblctx;
1247 lock.context.pid = pid;
1248 lock.context.tid = br_lck->fsp->conn->cnum;
1249 lock.start = start;
1250 lock.size = size;
1251 lock.fnum = br_lck->fsp->fnum;
1252 lock.lock_type = UNLOCK_LOCK;
1253 lock.lock_flav = lock_flav;
1254
1255 if (lock_flav == WINDOWS_LOCK) {
1256 return SMB_VFS_BRL_UNLOCK_WINDOWS(br_lck->fsp->conn, msg_ctx,
1257 br_lck, &lock);
1258 } else {
1259 return brl_unlock_posix(msg_ctx, br_lck, &lock);
1260 }
1261 }
1262
1263 /****************************************************************************
1264 Test if we could add a lock if we wanted to.
1265 Returns True if the region required is currently unlocked, False if locked.
1266 ****************************************************************************/
1267
1268 bool brl_locktest(struct byte_range_lock *br_lck,
1269 uint64_t smblctx,
1270 struct server_id pid,
1271 br_off start,
1272 br_off size,
1273 enum brl_type lock_type,
1274 enum brl_flavour lock_flav)
1275 {
1276 bool ret = True;
1277 unsigned int i;
1278 struct lock_struct lock;
1279 const struct lock_struct *locks = br_lck->lock_data;
1280 files_struct *fsp = br_lck->fsp;
1281
1282 lock.context.smblctx = smblctx;
1283 lock.context.pid = pid;
1284 lock.context.tid = br_lck->fsp->conn->cnum;
1285 lock.start = start;
1286 lock.size = size;
1287 lock.fnum = fsp->fnum;
1288 lock.lock_type = lock_type;
1289 lock.lock_flav = lock_flav;
1290
1291 /* Make sure existing locks don't conflict */
1292 for (i=0; i < br_lck->num_locks; i++) {
1293 /*
1294 * Our own locks don't conflict.
1295 */
1296 if (brl_conflict_other(&locks[i], &lock)) {
1297 return False;
1298 }
1299 }
1300
1301 /*
1302 * There is no lock held by an SMB daemon, check to
1303 * see if there is a POSIX lock from a UNIX or NFS process.
1304 * This only conflicts with Windows locks, not POSIX locks.
1305 */
1306
1307 if(lp_posix_locking(fsp->conn->params) && (lock_flav == WINDOWS_LOCK)) {
1308 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1309
1310 DEBUG(10,("brl_locktest: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1311 (double)start, (double)size, ret ? "locked" : "unlocked",
1312 fsp->fnum, fsp_str_dbg(fsp)));
1313
1314 /* We need to return the inverse of is_posix_locked. */
1315 ret = !ret;
1316 }
1317
1318 /* no conflicts - we could have added it */
1319 return ret;
1320 }
1321
1322 /****************************************************************************
1323 Query for existing locks.
1324 ****************************************************************************/
1325
1326 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1327 uint64_t *psmblctx,
1328 struct server_id pid,
1329 br_off *pstart,
1330 br_off *psize,
1331 enum brl_type *plock_type,
1332 enum brl_flavour lock_flav)
1333 {
1334 unsigned int i;
1335 struct lock_struct lock;
1336 const struct lock_struct *locks = br_lck->lock_data;
1337 files_struct *fsp = br_lck->fsp;
1338
1339 lock.context.smblctx = *psmblctx;
1340 lock.context.pid = pid;
1341 lock.context.tid = br_lck->fsp->conn->cnum;
1342 lock.start = *pstart;
1343 lock.size = *psize;
1344 lock.fnum = fsp->fnum;
1345 lock.lock_type = *plock_type;
1346 lock.lock_flav = lock_flav;
1347
1348 /* Make sure existing locks don't conflict */
1349 for (i=0; i < br_lck->num_locks; i++) {
1350 const struct lock_struct *exlock = &locks[i];
1351 bool conflict = False;
1352
1353 if (exlock->lock_flav == WINDOWS_LOCK) {
1354 conflict = brl_conflict(exlock, &lock);
1355 } else {
1356 conflict = brl_conflict_posix(exlock, &lock);
1357 }
1358
1359 if (conflict) {
1360 *psmblctx = exlock->context.smblctx;
1361 *pstart = exlock->start;
1362 *psize = exlock->size;
1363 *plock_type = exlock->lock_type;
1364 return NT_STATUS_LOCK_NOT_GRANTED;
1365 }
1366 }
1367
1368 /*
1369 * There is no lock held by an SMB daemon, check to
1370 * see if there is a POSIX lock from a UNIX or NFS process.
1371 */
1372
1373 if(lp_posix_locking(fsp->conn->params)) {
1374 bool ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1375
1376 DEBUG(10,("brl_lockquery: posix start=%.0f len=%.0f %s for fnum %d file %s\n",
1377 (double)*pstart, (double)*psize, ret ? "locked" : "unlocked",
1378 fsp->fnum, fsp_str_dbg(fsp)));
1379
1380 if (ret) {
1381 /* Hmmm. No clue what to set smblctx to - use -1. */
1382 *psmblctx = 0xFFFFFFFFFFFFFFFFLL;
1383 return NT_STATUS_LOCK_NOT_GRANTED;
1384 }
1385 }
1386
1387 return NT_STATUS_OK;
1388 }
1389
1390
1391 bool smb_vfs_call_brl_cancel_windows(struct vfs_handle_struct *handle,
1392 struct byte_range_lock *br_lck,
1393 struct lock_struct *plock,
1394 struct blocking_lock_record *blr)
1395 {
1396 VFS_FIND(brl_cancel_windows);
1397 return handle->fns->brl_cancel_windows(handle, br_lck, plock, blr);
1398 }
1399
1400 /****************************************************************************
1401 Remove a particular pending lock.
1402 ****************************************************************************/
1403 bool brl_lock_cancel(struct byte_range_lock *br_lck,
1404 uint64_t smblctx,
1405 struct server_id pid,
1406 br_off start,
1407 br_off size,
1408 enum brl_flavour lock_flav,
1409 struct blocking_lock_record *blr)
1410 {
1411 bool ret;
1412 struct lock_struct lock;
1413
1414 lock.context.smblctx = smblctx;
1415 lock.context.pid = pid;
1416 lock.context.tid = br_lck->fsp->conn->cnum;
1417 lock.start = start;
1418 lock.size = size;
1419 lock.fnum = br_lck->fsp->fnum;
1420 lock.lock_flav = lock_flav;
1421 /* lock.lock_type doesn't matter */
1422
1423 if (lock_flav == WINDOWS_LOCK) {
1424 ret = SMB_VFS_BRL_CANCEL_WINDOWS(br_lck->fsp->conn, br_lck,
1425 &lock, blr);
1426 } else {
1427 ret = brl_lock_cancel_default(br_lck, &lock);
1428 }
1429
1430 return ret;
1431 }
1432
1433 bool brl_lock_cancel_default(struct byte_range_lock *br_lck,
1434 struct lock_struct *plock)
1435 {
1436 unsigned int i;
1437 struct lock_struct *locks = br_lck->lock_data;
1438
1439 SMB_ASSERT(plock);
1440
1441 for (i = 0; i < br_lck->num_locks; i++) {
1442 struct lock_struct *lock = &locks[i];
1443
1444 /* For pending locks we *always* care about the fnum. */
1445 if (brl_same_context(&lock->context, &plock->context) &&
1446 lock->fnum == plock->fnum &&
1447 IS_PENDING_LOCK(lock->lock_type) &&
1448 lock->lock_flav == plock->lock_flav &&
1449 lock->start == plock->start &&
1450 lock->size == plock->size) {
1451 break;
1452 }
1453 }
1454
1455 if (i == br_lck->num_locks) {
1456 /* Didn't find it. */
1457 return False;
1458 }
1459
1460 if (i < br_lck->num_locks - 1) {
1461 /* Found this particular pending lock - delete it */
1462 memmove(&locks[i], &locks[i+1],
1463 sizeof(*locks)*((br_lck->num_locks-1) - i));
1464 }
1465
1466 br_lck->num_locks -= 1;
1467 br_lck->modified = True;
1468 return True;
1469 }
1470
1471 /****************************************************************************
1472 Remove any locks associated with a open file.
1473 We return True if this process owns any other Windows locks on this
1474 fd and so we should not immediately close the fd.
1475 ****************************************************************************/
1476
1477 void brl_close_fnum(struct messaging_context *msg_ctx,
1478 struct byte_range_lock *br_lck)
1479 {
1480 files_struct *fsp = br_lck->fsp;
1481 uint16 tid = fsp->conn->cnum;
1482 int fnum = fsp->fnum;
1483 unsigned int i, j, dcount=0;
1484 int num_deleted_windows_locks = 0;
1485 struct lock_struct *locks = br_lck->lock_data;
1486 struct server_id pid = procid_self();
1487 bool unlock_individually = False;
1488 bool posix_level2_contention_ended = false;
1489
1490 if(lp_posix_locking(fsp->conn->params)) {
1491
1492 /* Check if there are any Windows locks associated with this dev/ino
1493 pair that are not this fnum. If so we need to call unlock on each
1494 one in order to release the system POSIX locks correctly. */
1495
1496 for (i=0; i < br_lck->num_locks; i++) {
1497 struct lock_struct *lock = &locks[i];
1498
1499 if (!procid_equal(&lock->context.pid, &pid)) {
1500 continue;
1501 }
1502
1503 if (lock->lock_type != READ_LOCK && lock->lock_type != WRITE_LOCK) {
1504 continue; /* Ignore pending. */
1505 }
1506
1507 if (lock->context.tid != tid || lock->fnum != fnum) {
1508 unlock_individually = True;
1509 break;
1510 }
1511 }
1512
1513 if (unlock_individually) {
1514 struct lock_struct *locks_copy;
1515 unsigned int num_locks_copy;
1516
1517 /* Copy the current lock array. */
1518 if (br_lck->num_locks) {
1519 locks_copy = (struct lock_struct *)TALLOC_MEMDUP(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1520 if (!locks_copy) {
1521 smb_panic("brl_close_fnum: talloc failed");
1522 }
1523 } else {
1524 locks_copy = NULL;
1525 }
1526
1527 num_locks_copy = br_lck->num_locks;
1528
1529 for (i=0; i < num_locks_copy; i++) {
1530 struct lock_struct *lock = &locks_copy[i];
1531
1532 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid) &&
1533 (lock->fnum == fnum)) {
1534 brl_unlock(msg_ctx,
1535 br_lck,
1536 lock->context.smblctx,
1537 pid,
1538 lock->start,
1539 lock->size,
1540 lock->lock_flav);
1541 }
1542 }
1543 return;
1544 }
1545 }
1546
1547 /* We can bulk delete - any POSIX locks will be removed when the fd closes. */
1548
1549 /* Remove any existing locks for this fnum (or any fnum if they're POSIX). */
1550
1551 for (i=0; i < br_lck->num_locks; i++) {
1552 struct lock_struct *lock = &locks[i];
1553 bool del_this_lock = False;
1554
1555 if (lock->context.tid == tid && procid_equal(&lock->context.pid, &pid)) {
1556 if ((lock->lock_flav == WINDOWS_LOCK) && (lock->fnum == fnum)) {
1557 del_this_lock = True;
1558 num_deleted_windows_locks++;
1559 contend_level2_oplocks_end(br_lck->fsp,
1560 LEVEL2_CONTEND_WINDOWS_BRL);
1561 } else if (lock->lock_flav == POSIX_LOCK) {
1562 del_this_lock = True;
1563
1564 /* Only end level2 contention once for posix */
1565 if (!posix_level2_contention_ended) {
1566 posix_level2_contention_ended = true;
1567 contend_level2_oplocks_end(br_lck->fsp,
1568 LEVEL2_CONTEND_POSIX_BRL);
1569 }
1570 }
1571 }
1572
1573 if (del_this_lock) {
1574 /* Send unlock messages to any pending waiters that overlap. */
1575 for (j=0; j < br_lck->num_locks; j++) {
1576 struct lock_struct *pend_lock = &locks[j];
1577
1578 /* Ignore our own or non-pending locks. */
1579 if (!IS_PENDING_LOCK(pend_lock->lock_type)) {
1580 continue;
1581 }
1582
1583 /* Optimisation - don't send to this fnum as we're
1584 closing it. */
1585 if (pend_lock->context.tid == tid &&
1586 procid_equal(&pend_lock->context.pid, &pid) &&
1587 pend_lock->fnum == fnum) {
1588 continue;
1589 }
1590
1591 /* We could send specific lock info here... */
1592 if (brl_pending_overlap(lock, pend_lock)) {
1593 messaging_send(msg_ctx, pend_lock->context.pid,
1594 MSG_SMB_UNLOCK, &data_blob_null);
1595 }
1596 }
1597
1598 /* found it - delete it */
1599 if (br_lck->num_locks > 1 && i < br_lck->num_locks - 1) {
1600 memmove(&locks[i], &locks[i+1],
1601 sizeof(*locks)*((br_lck->num_locks-1) - i));
1602 }
1603 br_lck->num_locks--;
1604 br_lck->modified = True;
1605 i--;
1606 dcount++;
1607 }
1608 }
1609
1610 if(lp_posix_locking(fsp->conn->params) && num_deleted_windows_locks) {
1611 /* Reduce the Windows lock POSIX reference count on this dev/ino pair. */
1612 reduce_windows_lock_ref_count(fsp, num_deleted_windows_locks);
1613 }
1614 }
1615
1616 /****************************************************************************
1617 Ensure this set of lock entries is valid.
1618 ****************************************************************************/
1619 static bool validate_lock_entries(unsigned int *pnum_entries, struct lock_struct **pplocks)
1620 {
1621 unsigned int i;
1622 unsigned int num_valid_entries = 0;
1623 struct lock_struct *locks = *pplocks;
1624
1625 for (i = 0; i < *pnum_entries; i++) {
1626 struct lock_struct *lock_data = &locks[i];
1627 if (!serverid_exists(&lock_data->context.pid)) {
1628 /* This process no longer exists - mark this
1629 entry as invalid by zeroing it. */
1630 ZERO_STRUCTP(lock_data);
1631 } else {
1632 num_valid_entries++;
1633 }
1634 }
1635
1636 if (num_valid_entries != *pnum_entries) {
1637 struct lock_struct *new_lock_data = NULL;
1638
1639 if (num_valid_entries) {
1640 new_lock_data = SMB_MALLOC_ARRAY(struct lock_struct, num_valid_entries);
1641 if (!new_lock_data) {
1642 DEBUG(3, ("malloc fail\n"));
1643 return False;
1644 }
1645
1646 num_valid_entries = 0;
1647 for (i = 0; i < *pnum_entries; i++) {
1648 struct lock_struct *lock_data = &locks[i];
1649 if (lock_data->context.smblctx &&
1650 lock_data->context.tid) {
1651 /* Valid (nonzero) entry - copy it. */
1652 memcpy(&new_lock_data[num_valid_entries],
1653 lock_data, sizeof(struct lock_struct));
1654 num_valid_entries++;
1655 }
1656 }
1657 }
1658
1659 SAFE_FREE(*pplocks);
1660 *pplocks = new_lock_data;
1661 *pnum_entries = num_valid_entries;
1662 }
1663
1664 return True;
1665 }
1666
1667 struct brl_forall_cb {
1668 void (*fn)(struct file_id id, struct server_id pid,
1669 enum brl_type lock_type,
1670 enum brl_flavour lock_flav,
1671 br_off start, br_off size,
1672 void *private_data);
1673 void *private_data;
1674 };
1675
1676 /****************************************************************************
1677 Traverse the whole database with this function, calling traverse_callback
1678 on each lock.
1679 ****************************************************************************/
1680
1681 static int traverse_fn(struct db_record *rec, void *state)
1682 {
1683 struct brl_forall_cb *cb = (struct brl_forall_cb *)state;
1684 struct lock_struct *locks;
1685 struct file_id *key;
1686 unsigned int i;
1687 unsigned int num_locks = 0;
1688 unsigned int orig_num_locks = 0;
1689
1690 /* In a traverse function we must make a copy of
1691 dbuf before modifying it. */
1692
1693 locks = (struct lock_struct *)memdup(rec->value.dptr,
1694 rec->value.dsize);
1695 if (!locks) {
1696 return -1; /* Terminate traversal. */
1697 }
1698
1699 key = (struct file_id *)rec->key.dptr;
1700 orig_num_locks = num_locks = rec->value.dsize/sizeof(*locks);
1701
1702 /* Ensure the lock db is clean of entries from invalid processes. */
1703
1704 if (!validate_lock_entries(&num_locks, &locks)) {
1705 SAFE_FREE(locks);
1706 return -1; /* Terminate traversal */
1707 }
1708
1709 if (orig_num_locks != num_locks) {
1710 if (num_locks) {
1711 TDB_DATA data;
1712 data.dptr = (uint8_t *)locks;
1713 data.dsize = num_locks*sizeof(struct lock_struct);
1714 rec->store(rec, data, TDB_REPLACE);
1715 } else {
1716 rec->delete_rec(rec);
1717 }
1718 }
1719
1720 if (cb->fn) {
1721 for ( i=0; i<num_locks; i++) {
1722 cb->fn(*key,
1723 locks[i].context.pid,
1724 locks[i].lock_type,
1725 locks[i].lock_flav,
1726 locks[i].start,
1727 locks[i].size,
1728 cb->private_data);
1729 }
1730 }
1731
1732 SAFE_FREE(locks);
1733 return 0;
1734 }
1735
1736 /*******************************************************************
1737 Call the specified function on each lock in the database.
1738 ********************************************************************/
1739
1740 int brl_forall(void (*fn)(struct file_id id, struct server_id pid,
1741 enum brl_type lock_type,
1742 enum brl_flavour lock_flav,
1743 br_off start, br_off size,
1744 void *private_data),
1745 void *private_data)
1746 {
1747 struct brl_forall_cb cb;
1748
1749 if (!brlock_db) {
1750 return 0;
1751 }
1752 cb.fn = fn;
1753 cb.private_data = private_data;
1754 return brlock_db->traverse(brlock_db, traverse_fn, &cb);
1755 }
1756
1757 /*******************************************************************
1758 Store a potentially modified set of byte range lock data back into
1759 the database.
1760 Unlock the record.
1761 ********************************************************************/
1762
1763 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1764 {
1765 if (br_lck->read_only) {
1766 SMB_ASSERT(!br_lck->modified);
1767 }
1768
1769 if (!br_lck->modified) {
1770 goto done;
1771 }
1772
1773 if (br_lck->num_locks == 0) {
1774 /* No locks - delete this entry. */
1775 NTSTATUS status = br_lck->record->delete_rec(br_lck->record);
1776 if (!NT_STATUS_IS_OK(status)) {
1777 DEBUG(0, ("delete_rec returned %s\n",
1778 nt_errstr(status)));
1779 smb_panic("Could not delete byte range lock entry");
1780 }
1781 } else {
1782 TDB_DATA data;
1783 NTSTATUS status;
1784
1785 data.dptr = (uint8 *)br_lck->lock_data;
1786 data.dsize = br_lck->num_locks * sizeof(struct lock_struct);
1787
1788 status = br_lck->record->store(br_lck->record, data,
1789 TDB_REPLACE);
1790 if (!NT_STATUS_IS_OK(status)) {
1791 DEBUG(0, ("store returned %s\n", nt_errstr(status)));
1792 smb_panic("Could not store byte range mode entry");
1793 }
1794 }
1795
1796 done:
1797
1798 SAFE_FREE(br_lck->lock_data);
1799 TALLOC_FREE(br_lck->record);
1800 return 0;
1801 }
1802
1803 /*******************************************************************
1804 Fetch a set of byte range lock data from the database.
1805 Leave the record locked.
1806 TALLOC_FREE(brl) will release the lock in the destructor.
1807 ********************************************************************/
1808
1809 static struct byte_range_lock *brl_get_locks_internal(TALLOC_CTX *mem_ctx,
1810 files_struct *fsp, bool read_only)
1811 {
1812 TDB_DATA key, data;
1813 struct byte_range_lock *br_lck = TALLOC_P(mem_ctx, struct byte_range_lock);
1814
1815 if (br_lck == NULL) {
1816 return NULL;
1817 }
1818
1819 br_lck->fsp = fsp;
1820 br_lck->num_locks = 0;
1821 br_lck->modified = False;
1822 br_lck->key = fsp->file_id;
1823
1824 key.dptr = (uint8 *)&br_lck->key;
1825 key.dsize = sizeof(struct file_id);
1826
1827 if (!fsp->lockdb_clean) {
1828 /* We must be read/write to clean
1829 the dead entries. */
1830 read_only = False;
1831 }
1832
1833 if (read_only) {
1834 if (brlock_db->fetch(brlock_db, br_lck, key, &data) == -1) {
1835 DEBUG(3, ("Could not fetch byte range lock record\n"));
1836 TALLOC_FREE(br_lck);
1837 return NULL;
1838 }
1839 br_lck->record = NULL;
1840 }
1841 else {
1842 br_lck->record = brlock_db->fetch_locked(brlock_db, br_lck, key);
1843
1844 if (br_lck->record == NULL) {
1845 DEBUG(3, ("Could not lock byte range lock entry\n"));
1846 TALLOC_FREE(br_lck);
1847 return NULL;
1848 }
1849
1850 data = br_lck->record->value;
1851 }
1852
1853 br_lck->read_only = read_only;
1854 br_lck->lock_data = NULL;
1855
1856 talloc_set_destructor(br_lck, byte_range_lock_destructor);
1857
1858 br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1859
1860 if (br_lck->num_locks != 0) {
1861 br_lck->lock_data = SMB_MALLOC_ARRAY(struct lock_struct,
1862 br_lck->num_locks);
1863 if (br_lck->lock_data == NULL) {
1864 DEBUG(0, ("malloc failed\n"));
1865 TALLOC_FREE(br_lck);
1866 return NULL;
1867 }
1868
1869 memcpy(br_lck->lock_data, data.dptr, data.dsize);
1870 }
1871
1872 if (!fsp->lockdb_clean) {
1873 int orig_num_locks = br_lck->num_locks;
1874
1875 /* This is the first time we've accessed this. */
1876 /* Go through and ensure all entries exist - remove any that don't. */
1877 /* Makes the lockdb self cleaning at low cost. */
1878
1879 if (!validate_lock_entries(&br_lck->num_locks,
1880 &br_lck->lock_data)) {
1881 SAFE_FREE(br_lck->lock_data);
1882 TALLOC_FREE(br_lck);
1883 return NULL;
1884 }
1885
1886 /* Ensure invalid locks are cleaned up in the destructor. */
1887 if (orig_num_locks != br_lck->num_locks) {
1888 br_lck->modified = True;
1889 }
1890
1891 /* Mark the lockdb as "clean" as seen from this open file. */
1892 fsp->lockdb_clean = True;
1893 }
1894
1895 if (DEBUGLEVEL >= 10) {
1896 unsigned int i;
1897 struct lock_struct *locks = br_lck->lock_data;
1898 DEBUG(10,("brl_get_locks_internal: %u current locks on file_id %s\n",
1899 br_lck->num_locks,
1900 file_id_string_tos(&fsp->file_id)));
1901 for( i = 0; i < br_lck->num_locks; i++) {
1902 print_lock_struct(i, &locks[i]);
1903 }
1904 }
1905 return br_lck;
1906 }
1907
1908 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
1909 files_struct *fsp)
1910 {
1911 return brl_get_locks_internal(mem_ctx, fsp, False);
1912 }
1913
1914 struct byte_range_lock *brl_get_locks_readonly(files_struct *fsp)
1915 {
1916 struct byte_range_lock *br_lock;
1917
1918 if (lp_clustering()) {
1919 return brl_get_locks_internal(talloc_tos(), fsp, true);
1920 }
1921
1922 if ((fsp->brlock_rec != NULL)
1923 && (brlock_db->get_seqnum(brlock_db) == fsp->brlock_seqnum)) {
1924 return fsp->brlock_rec;
1925 }
1926
1927 TALLOC_FREE(fsp->brlock_rec);
1928
1929 br_lock = brl_get_locks_internal(talloc_tos(), fsp, false);
1930 if (br_lock == NULL) {
1931 return NULL;
1932 }
1933 fsp->brlock_seqnum = brlock_db->get_seqnum(brlock_db);
1934
1935 fsp->brlock_rec = talloc_zero(fsp, struct byte_range_lock);
1936 if (fsp->brlock_rec == NULL) {
1937 goto fail;
1938 }
1939 fsp->brlock_rec->fsp = fsp;
1940 fsp->brlock_rec->num_locks = br_lock->num_locks;
1941 fsp->brlock_rec->read_only = true;
1942 fsp->brlock_rec->key = br_lock->key;
1943
1944 fsp->brlock_rec->lock_data = (struct lock_struct *)
1945 talloc_memdup(fsp->brlock_rec, br_lock->lock_data,
1946 sizeof(struct lock_struct) * br_lock->num_locks);
1947 if (fsp->brlock_rec->lock_data == NULL) {
1948 goto fail;
1949 }
1950
1951 TALLOC_FREE(br_lock);
1952 return fsp->brlock_rec;
1953 fail:
1954 TALLOC_FREE(br_lock);
1955 TALLOC_FREE(fsp->brlock_rec);
1956 return NULL;
1957 }
1958
1959 struct brl_revalidate_state {
1960 ssize_t array_size;
1961 uint32 num_pids;
1962 struct server_id *pids;
1963 };
1964
1965 /*
1966 * Collect PIDs of all processes with pending entries
1967 */
1968
1969 static void brl_revalidate_collect(struct file_id id, struct server_id pid,
1970 enum brl_type lock_type,
1971 enum brl_flavour lock_flav,
1972 br_off start, br_off size,
1973 void *private_data)
1974 {
1975 struct brl_revalidate_state *state =
1976 (struct brl_revalidate_state *)private_data;
1977
1978 if (!IS_PENDING_LOCK(lock_type)) {
1979 return;
1980 }
1981
1982 add_to_large_array(state, sizeof(pid), (void *)&pid,
1983 &state->pids, &state->num_pids,
1984 &state->array_size);
1985 }
1986
1987 /*
1988 * qsort callback to sort the processes
1989 */
1990
1991 static int compare_procids(const void *p1, const void *p2)
1992 {
1993 const struct server_id *i1 = (struct server_id *)p1;
1994 const struct server_id *i2 = (struct server_id *)p2;
1995
1996 if (i1->pid < i2->pid) return -1;
1997 if (i2->pid > i2->pid) return 1;
1998 return 0;
1999 }
2000
2001 /*
2002 * Send a MSG_SMB_UNLOCK message to all processes with pending byte range
2003 * locks so that they retry. Mainly used in the cluster code after a node has
2004 * died.
2005 *
2006 * Done in two steps to avoid double-sends: First we collect all entries in an
2007 * array, then qsort that array and only send to non-dupes.
2008 */
2009
2010 static void brl_revalidate(struct messaging_context *msg_ctx,
2011 void *private_data,
2012 uint32_t msg_type,
2013 struct server_id server_id,
2014 DATA_BLOB *data)
2015 {
2016 struct brl_revalidate_state *state;
2017 uint32 i;
2018 struct server_id last_pid;
2019
2020 if (!(state = TALLOC_ZERO_P(NULL, struct brl_revalidate_state))) {
2021 DEBUG(0, ("talloc failed\n"));
2022 return;
2023 }
2024
2025 brl_forall(brl_revalidate_collect, state);
2026
2027 if (state->array_size == -1) {
2028 DEBUG(0, ("talloc failed\n"));
2029 goto done;
2030 }
2031
2032 if (state->num_pids == 0) {
2033 goto done;
2034 }
2035
2036 TYPESAFE_QSORT(state->pids, state->num_pids, compare_procids);
2037
2038 ZERO_STRUCT(last_pid);
2039
2040 for (i=0; i<state->num_pids; i++) {
2041 if (procid_equal(&last_pid, &state->pids[i])) {
2042 /*
2043 * We've seen that one already
2044 */
2045 continue;
2046 }
2047
2048 messaging_send(msg_ctx, state->pids[i], MSG_SMB_UNLOCK,
2049 &data_blob_null);
2050 last_pid = state->pids[i];
2051 }
2052
2053 done:
2054 TALLOC_FREE(state);
2055 return;
2056 }
2057
2058 void brl_register_msgs(struct messaging_context *msg_ctx)
2059 {
2060 messaging_register(msg_ctx, NULL, MSG_SMB_BRL_VALIDATE,
2061 brl_revalidate);
2062 }
reg import