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s3:printing: Allow to run samba-bgqd as a standalone systemd service
[Samba.git] / source3 / locking / brlock.c
blobb0295174954b08c409434aa18e80c99b70904327
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 "system/filesys.h"
29 #include "lib/util/server_id.h"
30 #include "locking/proto.h"
31 #include "smbd/globals.h"
32 #include "dbwrap/dbwrap.h"
33 #include "dbwrap/dbwrap_open.h"
34 #include "serverid.h"
35 #include "messages.h"
36 #include "util_tdb.h"
37
38 #undef DBGC_CLASS
39 #define DBGC_CLASS DBGC_LOCKING
40
41 /* The open brlock.tdb database. */
42
43 static struct db_context *brlock_db;
44
45 struct byte_range_lock {
46 struct files_struct *fsp;
47 TALLOC_CTX *req_mem_ctx;
48 const struct GUID *req_guid;
49 unsigned int num_locks;
50 bool modified;
51 struct lock_struct *lock_data;
52 struct db_record *record;
53 };
54
55 /****************************************************************************
56 Debug info at level 10 for lock struct.
57 ****************************************************************************/
58
59 static void print_lock_struct(unsigned int i, const struct lock_struct *pls)
60 {
61 struct server_id_buf tmp;
62
63 DBG_DEBUG("[%u]: smblctx = %"PRIu64", tid = %"PRIu32", pid = %s, "
64 "start = %"PRIu64", size = %"PRIu64", fnum = %"PRIu64", "
65 "%s %s\n",
66 i,
67 pls->context.smblctx,
68 pls->context.tid,
69 server_id_str_buf(pls->context.pid, &tmp),
70 pls->start,
71 pls->size,
72 pls->fnum,
73 lock_type_name(pls->lock_type),
74 lock_flav_name(pls->lock_flav));
75 }
76
77 unsigned int brl_num_locks(const struct byte_range_lock *brl)
78 {
79 return brl->num_locks;
80 }
81
82 struct files_struct *brl_fsp(struct byte_range_lock *brl)
83 {
84 return brl->fsp;
85 }
86
87 TALLOC_CTX *brl_req_mem_ctx(const struct byte_range_lock *brl)
88 {
89 if (brl->req_mem_ctx == NULL) {
90 return talloc_get_type_abort(brl, struct byte_range_lock);
91 }
92
93 return brl->req_mem_ctx;
94 }
95
96 const struct GUID *brl_req_guid(const struct byte_range_lock *brl)
97 {
98 if (brl->req_guid == NULL) {
99 static const struct GUID brl_zero_req_guid;
100 return &brl_zero_req_guid;
101 }
102
103 return brl->req_guid;
104 }
105
106 /****************************************************************************
107 See if two locking contexts are equal.
108 ****************************************************************************/
109
110 static bool brl_same_context(const struct lock_context *ctx1,
111 const struct lock_context *ctx2)
112 {
113 return (server_id_equal(&ctx1->pid, &ctx2->pid) &&
114 (ctx1->smblctx == ctx2->smblctx) &&
115 (ctx1->tid == ctx2->tid));
116 }
117
118 bool byte_range_valid(uint64_t ofs, uint64_t len)
119 {
120 uint64_t max_len = UINT64_MAX - ofs;
121 uint64_t effective_len;
122
123 /*
124 * [MS-FSA] specifies this:
125 *
126 * If (((FileOffset + Length - 1) < FileOffset) && Length != 0) {
127 * return STATUS_INVALID_LOCK_RANGE
128 * }
129 *
130 * We avoid integer wrapping and calculate
131 * max and effective len instead.
132 */
133
134 if (len == 0) {
135 return true;
136 }
137
138 effective_len = len - 1;
139 if (effective_len <= max_len) {
140 return true;
141 }
142
143 return false;
144 }
145
146 bool byte_range_overlap(uint64_t ofs1,
147 uint64_t len1,
148 uint64_t ofs2,
149 uint64_t len2)
150 {
151 uint64_t last1;
152 uint64_t last2;
153 bool valid;
154
155 /*
156 * This is based on [MS-FSA] 2.1.4.10
157 * Algorithm for Determining If a Range Access
158 * Conflicts with Byte-Range Locks
159 */
160
161 /*
162 * The {0, 0} range doesn't conflict with any byte-range lock
163 */
164 if (ofs1 == 0 && len1 == 0) {
165 return false;
166 }
167 if (ofs2 == 0 && len2 == 0) {
168 return false;
169 }
170
171 /*
172 * The caller should have checked that the ranges are
173 * valid. But currently we gracefully handle
174 * the overflow of a read/write check.
175 */
176 valid = byte_range_valid(ofs1, len1);
177 if (valid) {
178 last1 = ofs1 + len1 - 1;
179 } else {
180 last1 = UINT64_MAX;
181 }
182 valid = byte_range_valid(ofs2, len2);
183 if (valid) {
184 last2 = ofs2 + len2 - 1;
185 } else {
186 last2 = UINT64_MAX;
187 }
188
189 /*
190 * If one range starts after the last
191 * byte of the other range there's
192 * no conflict.
193 */
194 if (ofs1 > last2) {
195 return false;
196 }
197 if (ofs2 > last1) {
198 return false;
199 }
200
201 return true;
202 }
203
204 /****************************************************************************
205 See if lck1 and lck2 overlap.
206 ****************************************************************************/
207
208 static bool brl_overlap(const struct lock_struct *lck1,
209 const struct lock_struct *lck2)
210 {
211 return byte_range_overlap(lck1->start,
212 lck1->size,
213 lck2->start,
214 lck2->size);
215 }
216
217 /****************************************************************************
218 See if lock2 can be added when lock1 is in place.
219 ****************************************************************************/
220
221 static bool brl_conflict(const struct lock_struct *lck1,
222 const struct lock_struct *lck2)
223 {
224 /* Read locks never conflict. */
225 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
226 return False;
227 }
228
229 /* A READ lock can stack on top of a WRITE lock if they have the same
230 * context & fnum. */
231 if (lck1->lock_type == WRITE_LOCK && lck2->lock_type == READ_LOCK &&
232 brl_same_context(&lck1->context, &lck2->context) &&
233 lck1->fnum == lck2->fnum) {
234 return False;
235 }
236
237 return brl_overlap(lck1, lck2);
238 }
239
240 /****************************************************************************
241 See if lock2 can be added when lock1 is in place - when both locks are POSIX
242 flavour. POSIX locks ignore fnum - they only care about dev/ino which we
243 know already match.
244 ****************************************************************************/
245
246 static bool brl_conflict_posix(const struct lock_struct *lck1,
247 const struct lock_struct *lck2)
248 {
249 #if defined(DEVELOPER)
250 SMB_ASSERT(lck1->lock_flav == POSIX_LOCK);
251 SMB_ASSERT(lck2->lock_flav == POSIX_LOCK);
252 #endif
253
254 /* Read locks never conflict. */
255 if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
256 return False;
257 }
258
259 /* Locks on the same context don't conflict. Ignore fnum. */
260 if (brl_same_context(&lck1->context, &lck2->context)) {
261 return False;
262 }
263
264 /* One is read, the other write, or the context is different,
265 do they overlap ? */
266 return brl_overlap(lck1, lck2);
267 }
268
269 /****************************************************************************
270 Check to see if this lock conflicts, but ignore our own locks on the
271 same fnum only. This is the read/write lock check code path.
272 This is never used in the POSIX lock case.
273 ****************************************************************************/
274
275 static bool brl_conflict_other(const struct lock_struct *lock,
276 const struct lock_struct *rw_probe)
277 {
278 if (lock->lock_type == READ_LOCK && rw_probe->lock_type == READ_LOCK) {
279 return False;
280 }
281
282 if (lock->lock_flav == POSIX_LOCK &&
283 rw_probe->lock_flav == POSIX_LOCK) {
284 /*
285 * POSIX flavour locks never conflict here - this is only called
286 * in the read/write path.
287 */
288 return False;
289 }
290
291 if (!brl_overlap(lock, rw_probe)) {
292 /*
293 * I/O can only conflict when overlapping a lock, thus let it
294 * pass
295 */
296 return false;
297 }
298
299 if (!brl_same_context(&lock->context, &rw_probe->context)) {
300 /*
301 * Different process, conflict
302 */
303 return true;
304 }
305
306 if (lock->fnum != rw_probe->fnum) {
307 /*
308 * Different file handle, conflict
309 */
310 return true;
311 }
312
313 if ((lock->lock_type == READ_LOCK) &&
314 (rw_probe->lock_type == WRITE_LOCK)) {
315 /*
316 * Incoming WRITE locks conflict with existing READ locks even
317 * if the context is the same. JRA. See LOCKTEST7 in
318 * smbtorture.
319 */
320 return true;
321 }
322
323 /*
324 * I/O request compatible with existing lock, let it pass without
325 * conflict
326 */
327
328 return false;
329 }
330
331 /****************************************************************************
332 Open up the brlock.tdb database.
333 ****************************************************************************/
334
335 void brl_init(bool read_only)
336 {
337 int tdb_flags;
338 char *db_path;
339
340 if (brlock_db) {
341 return;
342 }
343
344 tdb_flags = SMBD_VOLATILE_TDB_FLAGS | TDB_SEQNUM;
345
346 db_path = lock_path(talloc_tos(), "brlock.tdb");
347 if (db_path == NULL) {
348 DEBUG(0, ("out of memory!\n"));
349 return;
350 }
351
352 brlock_db = db_open(NULL, db_path,
353 SMBD_VOLATILE_TDB_HASH_SIZE, tdb_flags,
354 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644,
355 DBWRAP_LOCK_ORDER_2, DBWRAP_FLAG_NONE);
356 if (!brlock_db) {
357 DEBUG(0,("Failed to open byte range locking database %s\n",
358 db_path));
359 TALLOC_FREE(db_path);
360 return;
361 }
362 TALLOC_FREE(db_path);
363 }
364
365 /****************************************************************************
366 Close down the brlock.tdb database.
367 ****************************************************************************/
368
369 void brl_shutdown(void)
370 {
371 TALLOC_FREE(brlock_db);
372 }
373
374 /****************************************************************************
375 Lock a range of bytes - Windows lock semantics.
376 ****************************************************************************/
377
378 NTSTATUS brl_lock_windows_default(struct byte_range_lock *br_lck,
379 struct lock_struct *plock)
380 {
381 unsigned int i;
382 files_struct *fsp = br_lck->fsp;
383 struct lock_struct *locks = br_lck->lock_data;
384 NTSTATUS status;
385 bool valid;
386
387 SMB_ASSERT(plock->lock_type != UNLOCK_LOCK);
388
389 valid = byte_range_valid(plock->start, plock->size);
390 if (!valid) {
391 return NT_STATUS_INVALID_LOCK_RANGE;
392 }
393
394 for (i=0; i < br_lck->num_locks; i++) {
395 /* Do any Windows or POSIX locks conflict ? */
396 if (brl_conflict(&locks[i], plock)) {
397 if (!serverid_exists(&locks[i].context.pid)) {
398 locks[i].context.pid.pid = 0;
399 br_lck->modified = true;
400 continue;
401 }
402 /* Remember who blocked us. */
403 plock->context.smblctx = locks[i].context.smblctx;
404 return NT_STATUS_LOCK_NOT_GRANTED;
405 }
406 }
407
408 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
409
410 /* We can get the Windows lock, now see if it needs to
411 be mapped into a lower level POSIX one, and if so can
412 we get it ? */
413
414 if (lp_posix_locking(fsp->conn->params)) {
415 int errno_ret;
416 if (!set_posix_lock_windows_flavour(fsp,
417 plock->start,
418 plock->size,
419 plock->lock_type,
420 &plock->context,
421 locks,
422 br_lck->num_locks,
423 &errno_ret)) {
424
425 /* We don't know who blocked us. */
426 plock->context.smblctx = 0xFFFFFFFFFFFFFFFFLL;
427
428 if (errno_ret == EACCES || errno_ret == EAGAIN) {
429 status = NT_STATUS_LOCK_NOT_GRANTED;
430 goto fail;
431 } else {
432 status = map_nt_error_from_unix(errno);
433 goto fail;
434 }
435 }
436 }
437
438 /* no conflicts - add it to the list of locks */
439 locks = talloc_realloc(br_lck, locks, struct lock_struct,
440 (br_lck->num_locks + 1));
441 if (!locks) {
442 status = NT_STATUS_NO_MEMORY;
443 goto fail;
444 }
445
446 memcpy(&locks[br_lck->num_locks], plock, sizeof(struct lock_struct));
447 br_lck->num_locks += 1;
448 br_lck->lock_data = locks;
449 br_lck->modified = True;
450
451 return NT_STATUS_OK;
452 fail:
453 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WINDOWS_BRL);
454 return status;
455 }
456
457 /****************************************************************************
458 Cope with POSIX range splits and merges.
459 ****************************************************************************/
460
461 static unsigned int brlock_posix_split_merge(struct lock_struct *lck_arr, /* Output array. */
462 struct lock_struct *ex, /* existing lock. */
463 struct lock_struct *plock) /* proposed lock. */
464 {
465 bool lock_types_differ = (ex->lock_type != plock->lock_type);
466
467 /* We can't merge non-conflicting locks on different context - ignore fnum. */
468
469 if (!brl_same_context(&ex->context, &plock->context)) {
470 /* Just copy. */
471 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
472 return 1;
473 }
474
475 /* We now know we have the same context. */
476
477 /* Did we overlap ? */
478
479 /*********************************************
480 +---------+
481 | ex |
482 +---------+
483 +-------+
484 | plock |
485 +-------+
486 OR....
487 +---------+
488 | ex |
489 +---------+
490 **********************************************/
491
492 if ( (ex->start > (plock->start + plock->size)) ||
493 (plock->start > (ex->start + ex->size))) {
494
495 /* No overlap with this lock - copy existing. */
496
497 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
498 return 1;
499 }
500
501 /*********************************************
502 +---------------------------+
503 | ex |
504 +---------------------------+
505 +---------------------------+
506 | plock | -> replace with plock.
507 +---------------------------+
508 OR
509 +---------------+
510 | ex |
511 +---------------+
512 +---------------------------+
513 | plock | -> replace with plock.
514 +---------------------------+
515
516 **********************************************/
517
518 if ( (ex->start >= plock->start) &&
519 (ex->start + ex->size <= plock->start + plock->size) ) {
520
521 /* Replace - discard existing lock. */
522
523 return 0;
524 }
525
526 /*********************************************
527 Adjacent after.
528 +-------+
529 | ex |
530 +-------+
531 +---------------+
532 | plock |
533 +---------------+
534
535 BECOMES....
536 +---------------+-------+
537 | plock | ex | - different lock types.
538 +---------------+-------+
539 OR.... (merge)
540 +-----------------------+
541 | plock | - same lock type.
542 +-----------------------+
543 **********************************************/
544
545 if (plock->start + plock->size == ex->start) {
546
547 /* If the lock types are the same, we merge, if different, we
548 add the remainder of the old lock. */
549
550 if (lock_types_differ) {
551 /* Add existing. */
552 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
553 return 1;
554 } else {
555 /* Merge - adjust incoming lock as we may have more
556 * merging to come. */
557 plock->size += ex->size;
558 return 0;
559 }
560 }
561
562 /*********************************************
563 Adjacent before.
564 +-------+
565 | ex |
566 +-------+
567 +---------------+
568 | plock |
569 +---------------+
570 BECOMES....
571 +-------+---------------+
572 | ex | plock | - different lock types
573 +-------+---------------+
574
575 OR.... (merge)
576 +-----------------------+
577 | plock | - same lock type.
578 +-----------------------+
579
580 **********************************************/
581
582 if (ex->start + ex->size == plock->start) {
583
584 /* If the lock types are the same, we merge, if different, we
585 add the existing lock. */
586
587 if (lock_types_differ) {
588 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
589 return 1;
590 } else {
591 /* Merge - adjust incoming lock as we may have more
592 * merging to come. */
593 plock->start = ex->start;
594 plock->size += ex->size;
595 return 0;
596 }
597 }
598
599 /*********************************************
600 Overlap after.
601 +-----------------------+
602 | ex |
603 +-----------------------+
604 +---------------+
605 | plock |
606 +---------------+
607 OR
608 +----------------+
609 | ex |
610 +----------------+
611 +---------------+
612 | plock |
613 +---------------+
614
615 BECOMES....
616 +---------------+-------+
617 | plock | ex | - different lock types.
618 +---------------+-------+
619 OR.... (merge)
620 +-----------------------+
621 | plock | - same lock type.
622 +-----------------------+
623 **********************************************/
624
625 if ( (ex->start >= plock->start) &&
626 (ex->start <= plock->start + plock->size) &&
627 (ex->start + ex->size > plock->start + plock->size) ) {
628
629 /* If the lock types are the same, we merge, if different, we
630 add the remainder of the old lock. */
631
632 if (lock_types_differ) {
633 /* Add remaining existing. */
634 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
635 /* Adjust existing start and size. */
636 lck_arr[0].start = plock->start + plock->size;
637 lck_arr[0].size = (ex->start + ex->size) - (plock->start + plock->size);
638 return 1;
639 } else {
640 /* Merge - adjust incoming lock as we may have more
641 * merging to come. */
642 plock->size += (ex->start + ex->size) - (plock->start + plock->size);
643 return 0;
644 }
645 }
646
647 /*********************************************
648 Overlap before.
649 +-----------------------+
650 | ex |
651 +-----------------------+
652 +---------------+
653 | plock |
654 +---------------+
655 OR
656 +-------------+
657 | ex |
658 +-------------+
659 +---------------+
660 | plock |
661 +---------------+
662
663 BECOMES....
664 +-------+---------------+
665 | ex | plock | - different lock types
666 +-------+---------------+
667
668 OR.... (merge)
669 +-----------------------+
670 | plock | - same lock type.
671 +-----------------------+
672
673 **********************************************/
674
675 if ( (ex->start < plock->start) &&
676 (ex->start + ex->size >= plock->start) &&
677 (ex->start + ex->size <= plock->start + plock->size) ) {
678
679 /* If the lock types are the same, we merge, if different, we
680 add the truncated old lock. */
681
682 if (lock_types_differ) {
683 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
684 /* Adjust existing size. */
685 lck_arr[0].size = plock->start - ex->start;
686 return 1;
687 } else {
688 /* Merge - adjust incoming lock as we may have more
689 * merging to come. MUST ADJUST plock SIZE FIRST ! */
690 plock->size += (plock->start - ex->start);
691 plock->start = ex->start;
692 return 0;
693 }
694 }
695
696 /*********************************************
697 Complete overlap.
698 +---------------------------+
699 | ex |
700 +---------------------------+
701 +---------+
702 | plock |
703 +---------+
704 BECOMES.....
705 +-------+---------+---------+
706 | ex | plock | ex | - different lock types.
707 +-------+---------+---------+
708 OR
709 +---------------------------+
710 | plock | - same lock type.
711 +---------------------------+
712 **********************************************/
713
714 if ( (ex->start < plock->start) && (ex->start + ex->size > plock->start + plock->size) ) {
715
716 if (lock_types_differ) {
717
718 /* We have to split ex into two locks here. */
719
720 memcpy(&lck_arr[0], ex, sizeof(struct lock_struct));
721 memcpy(&lck_arr[1], ex, sizeof(struct lock_struct));
722
723 /* Adjust first existing size. */
724 lck_arr[0].size = plock->start - ex->start;
725
726 /* Adjust second existing start and size. */
727 lck_arr[1].start = plock->start + plock->size;
728 lck_arr[1].size = (ex->start + ex->size) - (plock->start + plock->size);
729 return 2;
730 } else {
731 /* Just eat the existing locks, merge them into plock. */
732 plock->start = ex->start;
733 plock->size = ex->size;
734 return 0;
735 }
736 }
737
738 /* Never get here. */
739 smb_panic("brlock_posix_split_merge");
740 /* Notreached. */
741
742 /* Keep some compilers happy. */
743 return 0;
744 }
745
746 /****************************************************************************
747 Lock a range of bytes - POSIX lock semantics.
748 We must cope with range splits and merges.
749 ****************************************************************************/
750
751 static NTSTATUS brl_lock_posix(struct byte_range_lock *br_lck,
752 struct lock_struct *plock)
753 {
754 unsigned int i, count, posix_count;
755 struct lock_struct *locks = br_lck->lock_data;
756 struct lock_struct *tp;
757 bool break_oplocks = false;
758 NTSTATUS status;
759
760 /* No zero-zero locks for POSIX. */
761 if (plock->start == 0 && plock->size == 0) {
762 return NT_STATUS_INVALID_PARAMETER;
763 }
764
765 /* Don't allow 64-bit lock wrap. */
766 if (plock->start + plock->size - 1 < plock->start) {
767 return NT_STATUS_INVALID_PARAMETER;
768 }
769
770 /* The worst case scenario here is we have to split an
771 existing POSIX lock range into two, and add our lock,
772 so we need at most 2 more entries. */
773
774 tp = talloc_array(br_lck, struct lock_struct, br_lck->num_locks + 2);
775 if (!tp) {
776 return NT_STATUS_NO_MEMORY;
777 }
778
779 count = posix_count = 0;
780
781 for (i=0; i < br_lck->num_locks; i++) {
782 struct lock_struct *curr_lock = &locks[i];
783
784 if (curr_lock->lock_flav == WINDOWS_LOCK) {
785 /* Do any Windows flavour locks conflict ? */
786 if (brl_conflict(curr_lock, plock)) {
787 if (!serverid_exists(&curr_lock->context.pid)) {
788 curr_lock->context.pid.pid = 0;
789 br_lck->modified = true;
790 continue;
791 }
792 /* No games with error messages. */
793 TALLOC_FREE(tp);
794 /* Remember who blocked us. */
795 plock->context.smblctx = curr_lock->context.smblctx;
796 return NT_STATUS_LOCK_NOT_GRANTED;
797 }
798 /* Just copy the Windows lock into the new array. */
799 memcpy(&tp[count], curr_lock, sizeof(struct lock_struct));
800 count++;
801 } else {
802 unsigned int tmp_count = 0;
803
804 /* POSIX conflict semantics are different. */
805 if (brl_conflict_posix(curr_lock, plock)) {
806 if (!serverid_exists(&curr_lock->context.pid)) {
807 curr_lock->context.pid.pid = 0;
808 br_lck->modified = true;
809 continue;
810 }
811 /* Can't block ourselves with POSIX locks. */
812 /* No games with error messages. */
813 TALLOC_FREE(tp);
814 /* Remember who blocked us. */
815 plock->context.smblctx = curr_lock->context.smblctx;
816 return NT_STATUS_LOCK_NOT_GRANTED;
817 }
818
819 /* Work out overlaps. */
820 tmp_count += brlock_posix_split_merge(&tp[count], curr_lock, plock);
821 posix_count += tmp_count;
822 count += tmp_count;
823 }
824 }
825
826 /*
827 * Break oplocks while we hold a brl. Since lock() and unlock() calls
828 * are not symmetric with POSIX semantics, we cannot guarantee our
829 * contend_level2_oplocks_begin/end calls will be acquired and
830 * released one-for-one as with Windows semantics. Therefore we only
831 * call contend_level2_oplocks_begin if this is the first POSIX brl on
832 * the file.
833 */
834 break_oplocks = (posix_count == 0);
835 if (break_oplocks) {
836 contend_level2_oplocks_begin(br_lck->fsp,
837 LEVEL2_CONTEND_POSIX_BRL);
838 }
839
840 /* Try and add the lock in order, sorted by lock start. */
841 for (i=0; i < count; i++) {
842 struct lock_struct *curr_lock = &tp[i];
843
844 if (curr_lock->start <= plock->start) {
845 continue;
846 }
847 }
848
849 if (i < count) {
850 memmove(&tp[i+1], &tp[i],
851 (count - i)*sizeof(struct lock_struct));
852 }
853 memcpy(&tp[i], plock, sizeof(struct lock_struct));
854 count++;
855
856 /* We can get the POSIX lock, now see if it needs to
857 be mapped into a lower level POSIX one, and if so can
858 we get it ? */
859
860 if (lp_posix_locking(br_lck->fsp->conn->params)) {
861 int errno_ret;
862
863 /* The lower layer just needs to attempt to
864 get the system POSIX lock. We've weeded out
865 any conflicts above. */
866
867 if (!set_posix_lock_posix_flavour(br_lck->fsp,
868 plock->start,
869 plock->size,
870 plock->lock_type,
871 &plock->context,
872 &errno_ret)) {
873
874 /* We don't know who blocked us. */
875 plock->context.smblctx = 0xFFFFFFFFFFFFFFFFLL;
876
877 if (errno_ret == EACCES || errno_ret == EAGAIN) {
878 TALLOC_FREE(tp);
879 status = NT_STATUS_LOCK_NOT_GRANTED;
880 goto fail;
881 } else {
882 TALLOC_FREE(tp);
883 status = map_nt_error_from_unix(errno);
884 goto fail;
885 }
886 }
887 }
888
889 /* If we didn't use all the allocated size,
890 * Realloc so we don't leak entries per lock call. */
891 if (count < br_lck->num_locks + 2) {
892 tp = talloc_realloc(br_lck, tp, struct lock_struct, count);
893 if (!tp) {
894 status = NT_STATUS_NO_MEMORY;
895 goto fail;
896 }
897 }
898
899 br_lck->num_locks = count;
900 TALLOC_FREE(br_lck->lock_data);
901 br_lck->lock_data = tp;
902 locks = tp;
903 br_lck->modified = True;
904
905 /* A successful downgrade from write to read lock can trigger a lock
906 re-evalutation where waiting readers can now proceed. */
907
908 return NT_STATUS_OK;
909 fail:
910 if (break_oplocks) {
911 contend_level2_oplocks_end(br_lck->fsp,
912 LEVEL2_CONTEND_POSIX_BRL);
913 }
914 return status;
915 }
916
917 /****************************************************************************
918 Lock a range of bytes.
919 ****************************************************************************/
920
921 NTSTATUS brl_lock(
922 struct byte_range_lock *br_lck,
923 uint64_t smblctx,
924 struct server_id pid,
925 br_off start,
926 br_off size,
927 enum brl_type lock_type,
928 enum brl_flavour lock_flav,
929 struct server_id *blocker_pid,
930 uint64_t *psmblctx)
931 {
932 NTSTATUS ret;
933 struct lock_struct lock;
934
935 ZERO_STRUCT(lock);
936
937 lock = (struct lock_struct) {
938 .context.smblctx = smblctx,
939 .context.pid = pid,
940 .context.tid = br_lck->fsp->conn->cnum,
941 .start = start,
942 .size = size,
943 .fnum = br_lck->fsp->fnum,
944 .lock_type = lock_type,
945 .lock_flav = lock_flav
946 };
947
948 if (lock_flav == WINDOWS_LOCK) {
949 ret = SMB_VFS_BRL_LOCK_WINDOWS(
950 br_lck->fsp->conn, br_lck, &lock);
951 } else {
952 ret = brl_lock_posix(br_lck, &lock);
953 }
954
955 /* If we're returning an error, return who blocked us. */
956 if (!NT_STATUS_IS_OK(ret) && psmblctx) {
957 *blocker_pid = lock.context.pid;
958 *psmblctx = lock.context.smblctx;
959 }
960 return ret;
961 }
962
963 /****************************************************************************
964 Unlock a range of bytes - Windows semantics.
965 ****************************************************************************/
966
967 bool brl_unlock_windows_default(struct byte_range_lock *br_lck,
968 const struct lock_struct *plock)
969 {
970 unsigned int i;
971 struct lock_struct *locks = br_lck->lock_data;
972 enum brl_type deleted_lock_type = READ_LOCK; /* shut the compiler up.... */
973
974 SMB_ASSERT(plock->lock_type == UNLOCK_LOCK);
975
976
977 for (i = 0; i < br_lck->num_locks; i++) {
978 struct lock_struct *lock = &locks[i];
979
980 /* Only remove our own locks that match in start, size, and flavour. */
981 if (brl_same_context(&lock->context, &plock->context) &&
982 lock->fnum == plock->fnum &&
983 lock->lock_flav == WINDOWS_LOCK &&
984 lock->start == plock->start &&
985 lock->size == plock->size ) {
986 deleted_lock_type = lock->lock_type;
987 break;
988 }
989 }
990
991 if (i == br_lck->num_locks) {
992 /* we didn't find it */
993 return False;
994 }
995
996 ARRAY_DEL_ELEMENT(locks, i, br_lck->num_locks);
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 contend_level2_oplocks_end(br_lck->fsp, LEVEL2_CONTEND_WINDOWS_BRL);
1012 return True;
1013 }
1014
1015 /****************************************************************************
1016 Unlock a range of bytes - POSIX semantics.
1017 ****************************************************************************/
1018
1019 static bool brl_unlock_posix(struct byte_range_lock *br_lck,
1020 struct lock_struct *plock)
1021 {
1022 unsigned int i, count;
1023 struct lock_struct *tp;
1024 struct lock_struct *locks = br_lck->lock_data;
1025 bool overlap_found = False;
1026
1027 /* No zero-zero locks for POSIX. */
1028 if (plock->start == 0 && plock->size == 0) {
1029 return False;
1030 }
1031
1032 /* Don't allow 64-bit lock wrap. */
1033 if (plock->start + plock->size < plock->start ||
1034 plock->start + plock->size < plock->size) {
1035 DEBUG(10,("brl_unlock_posix: lock wrap\n"));
1036 return False;
1037 }
1038
1039 /* The worst case scenario here is we have to split an
1040 existing POSIX lock range into two, so we need at most
1041 1 more entry. */
1042
1043 tp = talloc_array(br_lck, struct lock_struct, br_lck->num_locks + 1);
1044 if (!tp) {
1045 DEBUG(10,("brl_unlock_posix: malloc fail\n"));
1046 return False;
1047 }
1048
1049 count = 0;
1050 for (i = 0; i < br_lck->num_locks; i++) {
1051 struct lock_struct *lock = &locks[i];
1052 unsigned int tmp_count;
1053
1054 /* Only remove our own locks - ignore fnum. */
1055 if (!brl_same_context(&lock->context, &plock->context)) {
1056 memcpy(&tp[count], lock, sizeof(struct lock_struct));
1057 count++;
1058 continue;
1059 }
1060
1061 if (lock->lock_flav == WINDOWS_LOCK) {
1062 /* Do any Windows flavour locks conflict ? */
1063 if (brl_conflict(lock, plock)) {
1064 TALLOC_FREE(tp);
1065 return false;
1066 }
1067 /* Just copy the Windows lock into the new array. */
1068 memcpy(&tp[count], lock, sizeof(struct lock_struct));
1069 count++;
1070 continue;
1071 }
1072
1073 /* Work out overlaps. */
1074 tmp_count = brlock_posix_split_merge(&tp[count], lock, plock);
1075
1076 if (tmp_count == 0) {
1077 /* plock overlapped the existing lock completely,
1078 or replaced it. Don't copy the existing lock. */
1079 overlap_found = true;
1080 } else if (tmp_count == 1) {
1081 /* Either no overlap, (simple copy of existing lock) or
1082 * an overlap of an existing lock. */
1083 /* If the lock changed size, we had an overlap. */
1084 if (tp[count].size != lock->size) {
1085 overlap_found = true;
1086 }
1087 count += tmp_count;
1088 } else if (tmp_count == 2) {
1089 /* We split a lock range in two. */
1090 overlap_found = true;
1091 count += tmp_count;
1092
1093 /* Optimisation... */
1094 /* We know we're finished here as we can't overlap any
1095 more POSIX locks. Copy the rest of the lock array. */
1096
1097 if (i < br_lck->num_locks - 1) {
1098 memcpy(&tp[count], &locks[i+1],
1099 sizeof(*locks)*((br_lck->num_locks-1) - i));
1100 count += ((br_lck->num_locks-1) - i);
1101 }
1102 break;
1103 }
1104
1105 }
1106
1107 if (!overlap_found) {
1108 /* Just ignore - no change. */
1109 TALLOC_FREE(tp);
1110 DEBUG(10,("brl_unlock_posix: No overlap - unlocked.\n"));
1111 return True;
1112 }
1113
1114 /* Unlock any POSIX regions. */
1115 if(lp_posix_locking(br_lck->fsp->conn->params)) {
1116 release_posix_lock_posix_flavour(br_lck->fsp,
1117 plock->start,
1118 plock->size,
1119 &plock->context,
1120 tp,
1121 count);
1122 }
1123
1124 /* Realloc so we don't leak entries per unlock call. */
1125 if (count) {
1126 tp = talloc_realloc(br_lck, tp, struct lock_struct, count);
1127 if (!tp) {
1128 DEBUG(10,("brl_unlock_posix: realloc fail\n"));
1129 return False;
1130 }
1131 } else {
1132 /* We deleted the last lock. */
1133 TALLOC_FREE(tp);
1134 tp = NULL;
1135 }
1136
1137 contend_level2_oplocks_end(br_lck->fsp,
1138 LEVEL2_CONTEND_POSIX_BRL);
1139
1140 br_lck->num_locks = count;
1141 TALLOC_FREE(br_lck->lock_data);
1142 locks = tp;
1143 br_lck->lock_data = tp;
1144 br_lck->modified = True;
1145
1146 return True;
1147 }
1148
1149 /****************************************************************************
1150 Unlock a range of bytes.
1151 ****************************************************************************/
1152
1153 bool brl_unlock(struct byte_range_lock *br_lck,
1154 uint64_t smblctx,
1155 struct server_id pid,
1156 br_off start,
1157 br_off size,
1158 enum brl_flavour lock_flav)
1159 {
1160 struct lock_struct lock;
1161
1162 lock.context.smblctx = smblctx;
1163 lock.context.pid = pid;
1164 lock.context.tid = br_lck->fsp->conn->cnum;
1165 lock.start = start;
1166 lock.size = size;
1167 lock.fnum = br_lck->fsp->fnum;
1168 lock.lock_type = UNLOCK_LOCK;
1169 lock.lock_flav = lock_flav;
1170
1171 if (lock_flav == WINDOWS_LOCK) {
1172 return SMB_VFS_BRL_UNLOCK_WINDOWS(
1173 br_lck->fsp->conn, br_lck, &lock);
1174 } else {
1175 return brl_unlock_posix(br_lck, &lock);
1176 }
1177 }
1178
1179 /****************************************************************************
1180 Test if we could add a lock if we wanted to.
1181 Returns True if the region required is currently unlocked, False if locked.
1182 ****************************************************************************/
1183
1184 bool brl_locktest(struct byte_range_lock *br_lck,
1185 const struct lock_struct *rw_probe)
1186 {
1187 bool ret = True;
1188 unsigned int i;
1189 struct lock_struct *locks = br_lck->lock_data;
1190 files_struct *fsp = br_lck->fsp;
1191
1192 /* Make sure existing locks don't conflict */
1193 for (i=0; i < br_lck->num_locks; i++) {
1194 /*
1195 * Our own locks don't conflict.
1196 */
1197 if (brl_conflict_other(&locks[i], rw_probe)) {
1198 if (br_lck->record == NULL) {
1199 /* readonly */
1200 return false;
1201 }
1202
1203 if (!serverid_exists(&locks[i].context.pid)) {
1204 locks[i].context.pid.pid = 0;
1205 br_lck->modified = true;
1206 continue;
1207 }
1208
1209 return False;
1210 }
1211 }
1212
1213 /*
1214 * There is no lock held by an SMB daemon, check to
1215 * see if there is a POSIX lock from a UNIX or NFS process.
1216 * This only conflicts with Windows locks, not POSIX locks.
1217 */
1218
1219 if(lp_posix_locking(fsp->conn->params) &&
1220 (rw_probe->lock_flav == WINDOWS_LOCK)) {
1221 /*
1222 * Make copies -- is_posix_locked might modify the values
1223 */
1224
1225 br_off start = rw_probe->start;
1226 br_off size = rw_probe->size;
1227 enum brl_type lock_type = rw_probe->lock_type;
1228
1229 ret = is_posix_locked(fsp, &start, &size, &lock_type, WINDOWS_LOCK);
1230
1231 DEBUG(10, ("brl_locktest: posix start=%ju len=%ju %s for %s "
1232 "file %s\n", (uintmax_t)start, (uintmax_t)size,
1233 ret ? "locked" : "unlocked",
1234 fsp_fnum_dbg(fsp), fsp_str_dbg(fsp)));
1235
1236 /* We need to return the inverse of is_posix_locked. */
1237 ret = !ret;
1238 }
1239
1240 /* no conflicts - we could have added it */
1241 return ret;
1242 }
1243
1244 /****************************************************************************
1245 Query for existing locks.
1246 ****************************************************************************/
1247
1248 NTSTATUS brl_lockquery(struct byte_range_lock *br_lck,
1249 uint64_t *psmblctx,
1250 struct server_id pid,
1251 br_off *pstart,
1252 br_off *psize,
1253 enum brl_type *plock_type,
1254 enum brl_flavour lock_flav)
1255 {
1256 unsigned int i;
1257 struct lock_struct lock;
1258 const struct lock_struct *locks = br_lck->lock_data;
1259 files_struct *fsp = br_lck->fsp;
1260
1261 lock.context.smblctx = *psmblctx;
1262 lock.context.pid = pid;
1263 lock.context.tid = br_lck->fsp->conn->cnum;
1264 lock.start = *pstart;
1265 lock.size = *psize;
1266 lock.fnum = fsp->fnum;
1267 lock.lock_type = *plock_type;
1268 lock.lock_flav = lock_flav;
1269
1270 /* Make sure existing locks don't conflict */
1271 for (i=0; i < br_lck->num_locks; i++) {
1272 const struct lock_struct *exlock = &locks[i];
1273 bool conflict = False;
1274
1275 if (exlock->lock_flav == WINDOWS_LOCK) {
1276 conflict = brl_conflict(exlock, &lock);
1277 } else {
1278 conflict = brl_conflict_posix(exlock, &lock);
1279 }
1280
1281 if (conflict) {
1282 *psmblctx = exlock->context.smblctx;
1283 *pstart = exlock->start;
1284 *psize = exlock->size;
1285 *plock_type = exlock->lock_type;
1286 return NT_STATUS_LOCK_NOT_GRANTED;
1287 }
1288 }
1289
1290 /*
1291 * There is no lock held by an SMB daemon, check to
1292 * see if there is a POSIX lock from a UNIX or NFS process.
1293 */
1294
1295 if(lp_posix_locking(fsp->conn->params)) {
1296 bool ret = is_posix_locked(fsp, pstart, psize, plock_type, POSIX_LOCK);
1297
1298 DEBUG(10, ("brl_lockquery: posix start=%ju len=%ju %s for %s "
1299 "file %s\n", (uintmax_t)*pstart,
1300 (uintmax_t)*psize, ret ? "locked" : "unlocked",
1301 fsp_fnum_dbg(fsp), fsp_str_dbg(fsp)));
1302
1303 if (ret) {
1304 /* Hmmm. No clue what to set smblctx to - use -1. */
1305 *psmblctx = 0xFFFFFFFFFFFFFFFFLL;
1306 return NT_STATUS_LOCK_NOT_GRANTED;
1307 }
1308 }
1309
1310 return NT_STATUS_OK;
1311 }
1312
1313
1314 /****************************************************************************
1315 Remove any locks associated with a open file.
1316 We return True if this process owns any other Windows locks on this
1317 fd and so we should not immediately close the fd.
1318 ****************************************************************************/
1319
1320 void brl_close_fnum(struct byte_range_lock *br_lck)
1321 {
1322 files_struct *fsp = br_lck->fsp;
1323 uint32_t tid = fsp->conn->cnum;
1324 uint64_t fnum = fsp->fnum;
1325 unsigned int i;
1326 struct lock_struct *locks = br_lck->lock_data;
1327 struct server_id pid = messaging_server_id(fsp->conn->sconn->msg_ctx);
1328 struct lock_struct *locks_copy;
1329 unsigned int num_locks_copy;
1330
1331 /* Copy the current lock array. */
1332 if (br_lck->num_locks) {
1333 locks_copy = (struct lock_struct *)talloc_memdup(br_lck, locks, br_lck->num_locks * sizeof(struct lock_struct));
1334 if (!locks_copy) {
1335 smb_panic("brl_close_fnum: talloc failed");
1336 }
1337 } else {
1338 locks_copy = NULL;
1339 }
1340
1341 num_locks_copy = br_lck->num_locks;
1342
1343 for (i=0; i < num_locks_copy; i++) {
1344 struct lock_struct *lock = &locks_copy[i];
1345
1346 if (lock->context.tid == tid &&
1347 server_id_equal(&lock->context.pid, &pid) &&
1348 (lock->fnum == fnum)) {
1349 brl_unlock(
1350 br_lck,
1351 lock->context.smblctx,
1352 pid,
1353 lock->start,
1354 lock->size,
1355 lock->lock_flav);
1356 }
1357 }
1358 }
1359
1360 bool brl_mark_disconnected(struct files_struct *fsp)
1361 {
1362 uint32_t tid = fsp->conn->cnum;
1363 uint64_t smblctx;
1364 uint64_t fnum = fsp->fnum;
1365 unsigned int i;
1366 struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
1367 struct byte_range_lock *br_lck = NULL;
1368
1369 if (fsp->op == NULL) {
1370 return false;
1371 }
1372
1373 smblctx = fsp->op->global->open_persistent_id;
1374
1375 if (!fsp->op->global->durable) {
1376 return false;
1377 }
1378
1379 if (fsp->current_lock_count == 0) {
1380 return true;
1381 }
1382
1383 br_lck = brl_get_locks(talloc_tos(), fsp);
1384 if (br_lck == NULL) {
1385 return false;
1386 }
1387
1388 for (i=0; i < br_lck->num_locks; i++) {
1389 struct lock_struct *lock = &br_lck->lock_data[i];
1390
1391 /*
1392 * as this is a durable handle, we only expect locks
1393 * of the current file handle!
1394 */
1395
1396 if (lock->context.smblctx != smblctx) {
1397 TALLOC_FREE(br_lck);
1398 return false;
1399 }
1400
1401 if (lock->context.tid != tid) {
1402 TALLOC_FREE(br_lck);
1403 return false;
1404 }
1405
1406 if (!server_id_equal(&lock->context.pid, &self)) {
1407 TALLOC_FREE(br_lck);
1408 return false;
1409 }
1410
1411 if (lock->fnum != fnum) {
1412 TALLOC_FREE(br_lck);
1413 return false;
1414 }
1415
1416 server_id_set_disconnected(&lock->context.pid);
1417 lock->context.tid = TID_FIELD_INVALID;
1418 lock->fnum = FNUM_FIELD_INVALID;
1419 }
1420
1421 br_lck->modified = true;
1422 TALLOC_FREE(br_lck);
1423 return true;
1424 }
1425
1426 bool brl_reconnect_disconnected(struct files_struct *fsp)
1427 {
1428 uint32_t tid = fsp->conn->cnum;
1429 uint64_t smblctx;
1430 uint64_t fnum = fsp->fnum;
1431 unsigned int i;
1432 struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
1433 struct byte_range_lock *br_lck = NULL;
1434
1435 if (fsp->op == NULL) {
1436 return false;
1437 }
1438
1439 smblctx = fsp->op->global->open_persistent_id;
1440
1441 if (!fsp->op->global->durable) {
1442 return false;
1443 }
1444
1445 /*
1446 * When reconnecting, we do not want to validate the brlock entries
1447 * and thereby remove our own (disconnected) entries but reactivate
1448 * them instead.
1449 */
1450
1451 br_lck = brl_get_locks(talloc_tos(), fsp);
1452 if (br_lck == NULL) {
1453 return false;
1454 }
1455
1456 if (br_lck->num_locks == 0) {
1457 TALLOC_FREE(br_lck);
1458 return true;
1459 }
1460
1461 for (i=0; i < br_lck->num_locks; i++) {
1462 struct lock_struct *lock = &br_lck->lock_data[i];
1463
1464 /*
1465 * as this is a durable handle we only expect locks
1466 * of the current file handle!
1467 */
1468
1469 if (lock->context.smblctx != smblctx) {
1470 TALLOC_FREE(br_lck);
1471 return false;
1472 }
1473
1474 if (lock->context.tid != TID_FIELD_INVALID) {
1475 TALLOC_FREE(br_lck);
1476 return false;
1477 }
1478
1479 if (!server_id_is_disconnected(&lock->context.pid)) {
1480 TALLOC_FREE(br_lck);
1481 return false;
1482 }
1483
1484 if (lock->fnum != FNUM_FIELD_INVALID) {
1485 TALLOC_FREE(br_lck);
1486 return false;
1487 }
1488
1489 lock->context.pid = self;
1490 lock->context.tid = tid;
1491 lock->fnum = fnum;
1492 }
1493
1494 fsp->current_lock_count = br_lck->num_locks;
1495 br_lck->modified = true;
1496 TALLOC_FREE(br_lck);
1497 return true;
1498 }
1499
1500 struct brl_forall_cb {
1501 void (*fn)(struct file_id id, struct server_id pid,
1502 enum brl_type lock_type,
1503 enum brl_flavour lock_flav,
1504 br_off start, br_off size,
1505 void *private_data);
1506 void *private_data;
1507 };
1508
1509 /****************************************************************************
1510 Traverse the whole database with this function, calling traverse_callback
1511 on each lock.
1512 ****************************************************************************/
1513
1514 static int brl_traverse_fn(struct db_record *rec, void *state)
1515 {
1516 struct brl_forall_cb *cb = (struct brl_forall_cb *)state;
1517 struct lock_struct *locks;
1518 struct file_id *key;
1519 unsigned int i;
1520 unsigned int num_locks = 0;
1521 TDB_DATA dbkey;
1522 TDB_DATA value;
1523
1524 dbkey = dbwrap_record_get_key(rec);
1525 value = dbwrap_record_get_value(rec);
1526
1527 /* In a traverse function we must make a copy of
1528 dbuf before modifying it. */
1529
1530 locks = (struct lock_struct *)talloc_memdup(
1531 talloc_tos(), value.dptr, value.dsize);
1532 if (!locks) {
1533 return -1; /* Terminate traversal. */
1534 }
1535
1536 key = (struct file_id *)dbkey.dptr;
1537 num_locks = value.dsize/sizeof(*locks);
1538
1539 if (cb->fn) {
1540 for ( i=0; i<num_locks; i++) {
1541 cb->fn(*key,
1542 locks[i].context.pid,
1543 locks[i].lock_type,
1544 locks[i].lock_flav,
1545 locks[i].start,
1546 locks[i].size,
1547 cb->private_data);
1548 }
1549 }
1550
1551 TALLOC_FREE(locks);
1552 return 0;
1553 }
1554
1555 /*******************************************************************
1556 Call the specified function on each lock in the database.
1557 ********************************************************************/
1558
1559 int brl_forall(void (*fn)(struct file_id id, struct server_id pid,
1560 enum brl_type lock_type,
1561 enum brl_flavour lock_flav,
1562 br_off start, br_off size,
1563 void *private_data),
1564 void *private_data)
1565 {
1566 struct brl_forall_cb cb;
1567 NTSTATUS status;
1568 int count = 0;
1569
1570 if (!brlock_db) {
1571 return 0;
1572 }
1573 cb.fn = fn;
1574 cb.private_data = private_data;
1575 status = dbwrap_traverse(brlock_db, brl_traverse_fn, &cb, &count);
1576
1577 if (!NT_STATUS_IS_OK(status)) {
1578 return -1;
1579 } else {
1580 return count;
1581 }
1582 }
1583
1584 /*******************************************************************
1585 Store a potentially modified set of byte range lock data back into
1586 the database.
1587 Unlock the record.
1588 ********************************************************************/
1589
1590 static void byte_range_lock_flush(struct byte_range_lock *br_lck)
1591 {
1592 unsigned i;
1593 struct lock_struct *locks = br_lck->lock_data;
1594
1595 if (!br_lck->modified) {
1596 DEBUG(10, ("br_lck not modified\n"));
1597 goto done;
1598 }
1599
1600 i = 0;
1601
1602 while (i < br_lck->num_locks) {
1603 if (locks[i].context.pid.pid == 0) {
1604 /*
1605 * Autocleanup, the process conflicted and does not
1606 * exist anymore.
1607 */
1608 locks[i] = locks[br_lck->num_locks-1];
1609 br_lck->num_locks -= 1;
1610 } else {
1611 i += 1;
1612 }
1613 }
1614
1615 if (br_lck->num_locks == 0) {
1616 /* No locks - delete this entry. */
1617 NTSTATUS status = dbwrap_record_delete(br_lck->record);
1618 if (!NT_STATUS_IS_OK(status)) {
1619 DEBUG(0, ("delete_rec returned %s\n",
1620 nt_errstr(status)));
1621 smb_panic("Could not delete byte range lock entry");
1622 }
1623 } else {
1624 TDB_DATA data = {
1625 .dsize = br_lck->num_locks * sizeof(struct lock_struct),
1626 .dptr = (uint8_t *)br_lck->lock_data,
1627 };
1628 NTSTATUS status;
1629
1630 status = dbwrap_record_store(br_lck->record, data, TDB_REPLACE);
1631 if (!NT_STATUS_IS_OK(status)) {
1632 DEBUG(0, ("store returned %s\n", nt_errstr(status)));
1633 smb_panic("Could not store byte range mode entry");
1634 }
1635 }
1636
1637 DEBUG(10, ("seqnum=%d\n", dbwrap_get_seqnum(brlock_db)));
1638
1639 done:
1640 br_lck->modified = false;
1641 TALLOC_FREE(br_lck->record);
1642 }
1643
1644 static int byte_range_lock_destructor(struct byte_range_lock *br_lck)
1645 {
1646 byte_range_lock_flush(br_lck);
1647 return 0;
1648 }
1649
1650 static bool brl_parse_data(struct byte_range_lock *br_lck, TDB_DATA data)
1651 {
1652 size_t data_len;
1653
1654 if (data.dsize == 0) {
1655 return true;
1656 }
1657 if (data.dsize % sizeof(struct lock_struct) != 0) {
1658 DEBUG(1, ("Invalid data size: %u\n", (unsigned)data.dsize));
1659 return false;
1660 }
1661
1662 br_lck->num_locks = data.dsize / sizeof(struct lock_struct);
1663 data_len = br_lck->num_locks * sizeof(struct lock_struct);
1664
1665 br_lck->lock_data = talloc_memdup(br_lck, data.dptr, data_len);
1666 if (br_lck->lock_data == NULL) {
1667 DEBUG(1, ("talloc_memdup failed\n"));
1668 return false;
1669 }
1670 return true;
1671 }
1672
1673 /*******************************************************************
1674 Fetch a set of byte range lock data from the database.
1675 Leave the record locked.
1676 TALLOC_FREE(brl) will release the lock in the destructor.
1677 ********************************************************************/
1678
1679 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx, files_struct *fsp)
1680 {
1681 TDB_DATA key, data;
1682 struct byte_range_lock *br_lck;
1683
1684 br_lck = talloc_zero(mem_ctx, struct byte_range_lock);
1685 if (br_lck == NULL) {
1686 return NULL;
1687 }
1688
1689 br_lck->fsp = fsp;
1690
1691 key.dptr = (uint8_t *)&fsp->file_id;
1692 key.dsize = sizeof(struct file_id);
1693
1694 br_lck->record = dbwrap_fetch_locked(brlock_db, br_lck, key);
1695
1696 if (br_lck->record == NULL) {
1697 DEBUG(3, ("Could not lock byte range lock entry\n"));
1698 TALLOC_FREE(br_lck);
1699 return NULL;
1700 }
1701
1702 data = dbwrap_record_get_value(br_lck->record);
1703
1704 if (!brl_parse_data(br_lck, data)) {
1705 TALLOC_FREE(br_lck);
1706 return NULL;
1707 }
1708
1709 talloc_set_destructor(br_lck, byte_range_lock_destructor);
1710
1711 if (DEBUGLEVEL >= 10) {
1712 unsigned int i;
1713 struct file_id_buf buf;
1714 struct lock_struct *locks = br_lck->lock_data;
1715 DBG_DEBUG("%u current locks on file_id %s\n",
1716 br_lck->num_locks,
1717 file_id_str_buf(fsp->file_id, &buf));
1718 for( i = 0; i < br_lck->num_locks; i++) {
1719 print_lock_struct(i, &locks[i]);
1720 }
1721 }
1722
1723 return br_lck;
1724 }
1725
1726 struct byte_range_lock *brl_get_locks_for_locking(TALLOC_CTX *mem_ctx,
1727 files_struct *fsp,
1728 TALLOC_CTX *req_mem_ctx,
1729 const struct GUID *req_guid)
1730 {
1731 struct byte_range_lock *br_lck = NULL;
1732
1733 br_lck = brl_get_locks(mem_ctx, fsp);
1734 if (br_lck == NULL) {
1735 return NULL;
1736 }
1737 SMB_ASSERT(req_mem_ctx != NULL);
1738 br_lck->req_mem_ctx = req_mem_ctx;
1739 SMB_ASSERT(req_guid != NULL);
1740 br_lck->req_guid = req_guid;
1741
1742 return br_lck;
1743 }
1744
1745 struct brl_get_locks_readonly_state {
1746 TALLOC_CTX *mem_ctx;
1747 struct byte_range_lock **br_lock;
1748 };
1749
1750 static void brl_get_locks_readonly_parser(TDB_DATA key, TDB_DATA data,
1751 void *private_data)
1752 {
1753 struct brl_get_locks_readonly_state *state =
1754 (struct brl_get_locks_readonly_state *)private_data;
1755 struct byte_range_lock *br_lck;
1756
1757 br_lck = talloc_pooled_object(
1758 state->mem_ctx, struct byte_range_lock, 1, data.dsize);
1759 if (br_lck == NULL) {
1760 *state->br_lock = NULL;
1761 return;
1762 }
1763 *br_lck = (struct byte_range_lock) { 0 };
1764 if (!brl_parse_data(br_lck, data)) {
1765 *state->br_lock = NULL;
1766 return;
1767 }
1768 *state->br_lock = br_lck;
1769 }
1770
1771 struct byte_range_lock *brl_get_locks_readonly(files_struct *fsp)
1772 {
1773 struct byte_range_lock *br_lock = NULL;
1774 struct brl_get_locks_readonly_state state;
1775 NTSTATUS status;
1776
1777 DEBUG(10, ("seqnum=%d, fsp->brlock_seqnum=%d\n",
1778 dbwrap_get_seqnum(brlock_db), fsp->brlock_seqnum));
1779
1780 if ((fsp->brlock_rec != NULL)
1781 && (dbwrap_get_seqnum(brlock_db) == fsp->brlock_seqnum)) {
1782 /*
1783 * We have cached the brlock_rec and the database did not
1784 * change.
1785 */
1786 return fsp->brlock_rec;
1787 }
1788
1789 /*
1790 * Parse the record fresh from the database
1791 */
1792
1793 state.mem_ctx = fsp;
1794 state.br_lock = &br_lock;
1795
1796 status = dbwrap_parse_record(
1797 brlock_db,
1798 make_tdb_data((uint8_t *)&fsp->file_id,
1799 sizeof(fsp->file_id)),
1800 brl_get_locks_readonly_parser, &state);
1801
1802 if (NT_STATUS_EQUAL(status,NT_STATUS_NOT_FOUND)) {
1803 /*
1804 * No locks on this file. Return an empty br_lock.
1805 */
1806 br_lock = talloc_zero(fsp, struct byte_range_lock);
1807 if (br_lock == NULL) {
1808 return NULL;
1809 }
1810
1811 } else if (!NT_STATUS_IS_OK(status)) {
1812 DEBUG(3, ("Could not parse byte range lock record: "
1813 "%s\n", nt_errstr(status)));
1814 return NULL;
1815 }
1816 if (br_lock == NULL) {
1817 return NULL;
1818 }
1819
1820 br_lock->fsp = fsp;
1821 br_lock->modified = false;
1822 br_lock->record = NULL;
1823
1824 /*
1825 * Cache the brlock struct, invalidated when the dbwrap_seqnum
1826 * changes. See beginning of this routine.
1827 */
1828 TALLOC_FREE(fsp->brlock_rec);
1829 fsp->brlock_rec = br_lock;
1830 fsp->brlock_seqnum = dbwrap_get_seqnum(brlock_db);
1831
1832 return br_lock;
1833 }
1834
1835 bool brl_cleanup_disconnected(struct file_id fid, uint64_t open_persistent_id)
1836 {
1837 bool ret = false;
1838 TALLOC_CTX *frame = talloc_stackframe();
1839 TDB_DATA key, val;
1840 struct db_record *rec;
1841 struct lock_struct *lock;
1842 unsigned n, num;
1843 struct file_id_buf buf;
1844 NTSTATUS status;
1845
1846 key = make_tdb_data((void*)&fid, sizeof(fid));
1847
1848 rec = dbwrap_fetch_locked(brlock_db, frame, key);
1849 if (rec == NULL) {
1850 DBG_INFO("failed to fetch record for file %s\n",
1851 file_id_str_buf(fid, &buf));
1852 goto done;
1853 }
1854
1855 val = dbwrap_record_get_value(rec);
1856 lock = (struct lock_struct*)val.dptr;
1857 num = val.dsize / sizeof(struct lock_struct);
1858 if (lock == NULL) {
1859 DBG_DEBUG("no byte range locks for file %s\n",
1860 file_id_str_buf(fid, &buf));
1861 ret = true;
1862 goto done;
1863 }
1864
1865 for (n=0; n<num; n++) {
1866 struct lock_context *ctx = &lock[n].context;
1867
1868 if (!server_id_is_disconnected(&ctx->pid)) {
1869 struct server_id_buf tmp;
1870 DBG_INFO("byte range lock "
1871 "%s used by server %s, do not cleanup\n",
1872 file_id_str_buf(fid, &buf),
1873 server_id_str_buf(ctx->pid, &tmp));
1874 goto done;
1875 }
1876
1877 if (ctx->smblctx != open_persistent_id) {
1878 DBG_INFO("byte range lock %s expected smblctx %"PRIu64" "
1879 "but found %"PRIu64", do not cleanup\n",
1880 file_id_str_buf(fid, &buf),
1881 open_persistent_id,
1882 ctx->smblctx);
1883 goto done;
1884 }
1885 }
1886
1887 status = dbwrap_record_delete(rec);
1888 if (!NT_STATUS_IS_OK(status)) {
1889 DBG_INFO("failed to delete record "
1890 "for file %s from %s, open %"PRIu64": %s\n",
1891 file_id_str_buf(fid, &buf),
1892 dbwrap_name(brlock_db),
1893 open_persistent_id,
1894 nt_errstr(status));
1895 goto done;
1896 }
1897
1898 DBG_DEBUG("file %s cleaned up %u entries from open %"PRIu64"\n",
1899 file_id_str_buf(fid, &buf),
1900 num,
1901 open_persistent_id);
1902
1903 ret = true;
1904 done:
1905 talloc_free(frame);
1906 return ret;
1907 }
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