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