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Fix proxy module
[Samba.git] / source3 / smbd / fileio.c
blob3e3f0943b3db5dd1519581aef8dec46db01dff85
1 /*
2 Unix SMB/Netbios implementation.
3 Version 1.9.
4 read/write to a files_struct
5 Copyright (C) Andrew Tridgell 1992-1998
6 Copyright (C) Jeremy Allison 2000-2002. - write cache.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "includes.h"
23 #include "smbd/globals.h"
24
25 static bool setup_write_cache(files_struct *, SMB_OFF_T);
26
27 /****************************************************************************
28 Read from write cache if we can.
29 ****************************************************************************/
30
31 static bool read_from_write_cache(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
32 {
33 write_cache *wcp = fsp->wcp;
34
35 if(!wcp) {
36 return False;
37 }
38
39 if( n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size) {
40 return False;
41 }
42
43 memcpy(data, wcp->data + (pos - wcp->offset), n);
44
45 DO_PROFILE_INC(writecache_read_hits);
46
47 return True;
48 }
49
50 /****************************************************************************
51 Read from a file.
52 ****************************************************************************/
53
54 ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
55 {
56 ssize_t ret=0,readret;
57
58 /* you can't read from print files */
59 if (fsp->print_file) {
60 return -1;
61 }
62
63 /*
64 * Serve from write cache if we can.
65 */
66
67 if(read_from_write_cache(fsp, data, pos, n)) {
68 fsp->fh->pos = pos + n;
69 fsp->fh->position_information = fsp->fh->pos;
70 return n;
71 }
72
73 flush_write_cache(fsp, READ_FLUSH);
74
75 fsp->fh->pos = pos;
76
77 if (n > 0) {
78 #ifdef DMF_FIX
79 int numretries = 3;
80 tryagain:
81 readret = SMB_VFS_PREAD(fsp,data,n,pos);
82
83 if (readret == -1) {
84 if ((errno == EAGAIN) && numretries) {
85 DEBUG(3,("read_file EAGAIN retry in 10 seconds\n"));
86 (void)sleep(10);
87 --numretries;
88 goto tryagain;
89 }
90 return -1;
91 }
92 #else /* NO DMF fix. */
93 readret = SMB_VFS_PREAD(fsp,data,n,pos);
94
95 if (readret == -1) {
96 return -1;
97 }
98 #endif
99 if (readret > 0) {
100 ret += readret;
101 }
102 }
103
104 DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
105 fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
106
107 fsp->fh->pos += ret;
108 fsp->fh->position_information = fsp->fh->pos;
109
110 return(ret);
111 }
112
113 /****************************************************************************
114 *Really* write to a file.
115 ****************************************************************************/
116
117 static ssize_t real_write_file(struct smb_request *req,
118 files_struct *fsp,
119 const char *data,
120 SMB_OFF_T pos,
121 size_t n)
122 {
123 ssize_t ret;
124
125 if (pos == -1) {
126 ret = vfs_write_data(req, fsp, data, n);
127 } else {
128 fsp->fh->pos = pos;
129 if (pos && lp_strict_allocate(SNUM(fsp->conn))) {
130 if (vfs_fill_sparse(fsp, pos) == -1) {
131 return -1;
132 }
133 }
134 ret = vfs_pwrite_data(req, fsp, data, n, pos);
135 }
136
137 DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
138 fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
139
140 if (ret != -1) {
141 fsp->fh->pos += ret;
142
143 /* Yes - this is correct - writes don't update this. JRA. */
144 /* Found by Samba4 tests. */
145 #if 0
146 fsp->position_information = fsp->pos;
147 #endif
148 }
149
150 return ret;
151 }
152
153 /****************************************************************************
154 File size cache change.
155 Updates size on disk but doesn't flush the cache.
156 ****************************************************************************/
157
158 static int wcp_file_size_change(files_struct *fsp)
159 {
160 int ret;
161 write_cache *wcp = fsp->wcp;
162
163 wcp->file_size = wcp->offset + wcp->data_size;
164 ret = SMB_VFS_FTRUNCATE(fsp, wcp->file_size);
165 if (ret == -1) {
166 DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f error %s\n",
167 fsp->fsp_name, (double)wcp->file_size, strerror(errno) ));
168 }
169 return ret;
170 }
171
172 static void update_write_time_handler(struct event_context *ctx,
173 struct timed_event *te,
174 struct timeval now,
175 void *private_data)
176 {
177 files_struct *fsp = (files_struct *)private_data;
178
179 /* Remove the timed event handler. */
180 TALLOC_FREE(fsp->update_write_time_event);
181 DEBUG(5, ("Update write time on %s\n", fsp->fsp_name));
182
183 /* change the write time if not already changed by someone else */
184 update_write_time(fsp);
185 }
186
187 /*********************************************************
188 Schedule a write time update for WRITE_TIME_UPDATE_USEC_DELAY
189 in the future.
190 *********************************************************/
191
192 void trigger_write_time_update(struct files_struct *fsp)
193 {
194 int delay;
195
196 if (fsp->write_time_forced) {
197 /* No point - "sticky" write times
198 * in effect.
199 */
200 return;
201 }
202
203 if (fsp->update_write_time_triggered) {
204 /*
205 * We only update the write time
206 * on the first write. After that
207 * no other writes affect this.
208 */
209 return;
210 }
211 fsp->update_write_time_triggered = true;
212
213 delay = lp_parm_int(SNUM(fsp->conn),
214 "smbd", "writetimeupdatedelay",
215 WRITE_TIME_UPDATE_USEC_DELAY);
216
217 /* trigger the update 2 seconds later */
218 fsp->update_write_time_on_close = true;
219 fsp->update_write_time_event =
220 event_add_timed(smbd_event_context(), NULL,
221 timeval_current_ofs(0, delay),
222 update_write_time_handler, fsp);
223 }
224
225 void trigger_write_time_update_immediate(struct files_struct *fsp)
226 {
227 if (fsp->write_time_forced) {
228 /*
229 * No point - "sticky" write times
230 * in effect.
231 */
232 return;
233 }
234
235 TALLOC_FREE(fsp->update_write_time_event);
236 DEBUG(5, ("Update write time immediate on %s\n", fsp->fsp_name));
237
238 fsp->update_write_time_triggered = true;
239
240 fsp->update_write_time_on_close = false;
241 update_write_time(fsp);
242 }
243
244 /****************************************************************************
245 Write to a file.
246 ****************************************************************************/
247
248 ssize_t write_file(struct smb_request *req,
249 files_struct *fsp,
250 const char *data,
251 SMB_OFF_T pos,
252 size_t n)
253 {
254 write_cache *wcp = fsp->wcp;
255 ssize_t total_written = 0;
256 int write_path = -1;
257
258 if (fsp->print_file) {
259 fstring sharename;
260 uint32 jobid;
261
262 if (!rap_to_pjobid(fsp->rap_print_jobid, sharename, &jobid)) {
263 DEBUG(3,("write_file: Unable to map RAP jobid %u to jobid.\n",
264 (unsigned int)fsp->rap_print_jobid ));
265 errno = EBADF;
266 return -1;
267 }
268
269 return print_job_write(SNUM(fsp->conn), jobid, data, pos, n);
270 }
271
272 if (!fsp->can_write) {
273 errno = EPERM;
274 return -1;
275 }
276
277 if (!fsp->modified) {
278 SMB_STRUCT_STAT st;
279 fsp->modified = True;
280
281 if (SMB_VFS_FSTAT(fsp, &st) == 0) {
282 int dosmode;
283 trigger_write_time_update(fsp);
284 dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
285 if ((lp_store_dos_attributes(SNUM(fsp->conn)) ||
286 MAP_ARCHIVE(fsp->conn)) &&
287 !IS_DOS_ARCHIVE(dosmode)) {
288 file_set_dosmode(fsp->conn,fsp->fsp_name,
289 dosmode | aARCH,&st,
290 NULL,
291 false);
292 }
293
294 /*
295 * If this is the first write and we have an exclusive oplock then setup
296 * the write cache.
297 */
298
299 if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
300 setup_write_cache(fsp, st.st_size);
301 wcp = fsp->wcp;
302 }
303 }
304 }
305
306 #ifdef WITH_PROFILE
307 DO_PROFILE_INC(writecache_total_writes);
308 if (!fsp->oplock_type) {
309 DO_PROFILE_INC(writecache_non_oplock_writes);
310 }
311 #endif
312
313 /*
314 * If this file is level II oplocked then we need
315 * to grab the shared memory lock and inform all
316 * other files with a level II lock that they need
317 * to flush their read caches. We keep the lock over
318 * the shared memory area whilst doing this.
319 */
320
321 release_level_2_oplocks_on_change(fsp);
322
323 #ifdef WITH_PROFILE
324 if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
325 DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
326 nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
327 profile_p->writecache_init_writes,
328 profile_p->writecache_abutted_writes,
329 profile_p->writecache_total_writes,
330 profile_p->writecache_non_oplock_writes,
331 profile_p->writecache_allocated_write_caches,
332 profile_p->writecache_num_write_caches,
333 profile_p->writecache_direct_writes,
334 profile_p->writecache_num_perfect_writes,
335 profile_p->writecache_read_hits ));
336
337 DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
338 profile_p->writecache_flushed_writes[SEEK_FLUSH],
339 profile_p->writecache_flushed_writes[READ_FLUSH],
340 profile_p->writecache_flushed_writes[WRITE_FLUSH],
341 profile_p->writecache_flushed_writes[READRAW_FLUSH],
342 profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
343 profile_p->writecache_flushed_writes[CLOSE_FLUSH],
344 profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
345 }
346 #endif
347
348 if (wcp && req->unread_bytes) {
349 /* If we're using receivefile don't
350 * deal with a write cache.
351 */
352 flush_write_cache(fsp, WRITE_FLUSH);
353 delete_write_cache(fsp);
354 wcp = NULL;
355 }
356
357 if(!wcp) {
358 DO_PROFILE_INC(writecache_direct_writes);
359 total_written = real_write_file(req, fsp, data, pos, n);
360 return total_written;
361 }
362
363 DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f wcp->data_size=%u\n",
364 fsp->fsp_name, fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size));
365
366 fsp->fh->pos = pos + n;
367
368 /*
369 * If we have active cache and it isn't contiguous then we flush.
370 * NOTE: There is a small problem with running out of disk ....
371 */
372
373 if (wcp->data_size) {
374 bool cache_flush_needed = False;
375
376 if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
377
378 /* ASCII art.... JRA.
379
380 +--------------+-----
381 | Cached data | Rest of allocated cache buffer....
382 +--------------+-----
383
384 +-------------------+
385 | Data to write |
386 +-------------------+
387
388 */
389
390 /*
391 * Start of write overlaps or abutts the existing data.
392 */
393
394 size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
395
396 memcpy(wcp->data + (pos - wcp->offset), data, data_used);
397
398 /*
399 * Update the current buffer size with the new data.
400 */
401
402 if(pos + data_used > wcp->offset + wcp->data_size) {
403 wcp->data_size = pos + data_used - wcp->offset;
404 }
405
406 /*
407 * Update the file size if changed.
408 */
409
410 if (wcp->offset + wcp->data_size > wcp->file_size) {
411 if (wcp_file_size_change(fsp) == -1) {
412 return -1;
413 }
414 }
415
416 /*
417 * If we used all the data then
418 * return here.
419 */
420
421 if(n == data_used) {
422 return n;
423 } else {
424 cache_flush_needed = True;
425 }
426 /*
427 * Move the start of data forward by the amount used,
428 * cut down the amount left by the same amount.
429 */
430
431 data += data_used;
432 pos += data_used;
433 n -= data_used;
434
435 DO_PROFILE_INC(writecache_abutted_writes);
436 total_written = data_used;
437
438 write_path = 1;
439
440 } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
441 (pos + n <= wcp->offset + wcp->alloc_size)) {
442
443 /* ASCII art.... JRA.
444
445 +---------------+
446 | Cache buffer |
447 +---------------+
448
449 +-------------------+
450 | Data to write |
451 +-------------------+
452
453 */
454
455 /*
456 * End of write overlaps the existing data.
457 */
458
459 size_t data_used = pos + n - wcp->offset;
460
461 memcpy(wcp->data, data + n - data_used, data_used);
462
463 /*
464 * Update the current buffer size with the new data.
465 */
466
467 if(pos + n > wcp->offset + wcp->data_size) {
468 wcp->data_size = pos + n - wcp->offset;
469 }
470
471 /*
472 * Update the file size if changed.
473 */
474
475 if (wcp->offset + wcp->data_size > wcp->file_size) {
476 if (wcp_file_size_change(fsp) == -1) {
477 return -1;
478 }
479 }
480
481 /*
482 * We don't need to move the start of data, but we
483 * cut down the amount left by the amount used.
484 */
485
486 n -= data_used;
487
488 /*
489 * We cannot have used all the data here.
490 */
491
492 cache_flush_needed = True;
493
494 DO_PROFILE_INC(writecache_abutted_writes);
495 total_written = data_used;
496
497 write_path = 2;
498
499 } else if ( (pos >= wcp->file_size) &&
500 (wcp->offset + wcp->data_size == wcp->file_size) &&
501 (pos > wcp->offset + wcp->data_size) &&
502 (pos < wcp->offset + wcp->alloc_size) ) {
503
504 /* ASCII art.... JRA.
505
506 End of file ---->|
507
508 +---------------+---------------+
509 | Cached data | Cache buffer |
510 +---------------+---------------+
511
512 +-------------------+
513 | Data to write |
514 +-------------------+
515
516 */
517
518 /*
519 * Non-contiguous write part of which fits within
520 * the cache buffer and is extending the file
521 * and the cache contents reflect the current
522 * data up to the current end of the file.
523 */
524
525 size_t data_used;
526
527 if(pos + n <= wcp->offset + wcp->alloc_size) {
528 data_used = n;
529 } else {
530 data_used = wcp->offset + wcp->alloc_size - pos;
531 }
532
533 /*
534 * Fill in the non-continuous area with zeros.
535 */
536
537 memset(wcp->data + wcp->data_size, '\0',
538 pos - (wcp->offset + wcp->data_size) );
539
540 memcpy(wcp->data + (pos - wcp->offset), data, data_used);
541
542 /*
543 * Update the current buffer size with the new data.
544 */
545
546 if(pos + data_used > wcp->offset + wcp->data_size) {
547 wcp->data_size = pos + data_used - wcp->offset;
548 }
549
550 /*
551 * Update the file size if changed.
552 */
553
554 if (wcp->offset + wcp->data_size > wcp->file_size) {
555 if (wcp_file_size_change(fsp) == -1) {
556 return -1;
557 }
558 }
559
560 /*
561 * If we used all the data then
562 * return here.
563 */
564
565 if(n == data_used) {
566 return n;
567 } else {
568 cache_flush_needed = True;
569 }
570
571 /*
572 * Move the start of data forward by the amount used,
573 * cut down the amount left by the same amount.
574 */
575
576 data += data_used;
577 pos += data_used;
578 n -= data_used;
579
580 DO_PROFILE_INC(writecache_abutted_writes);
581 total_written = data_used;
582
583 write_path = 3;
584
585 } else if ( (pos >= wcp->file_size) &&
586 (n == 1) &&
587 (wcp->file_size == wcp->offset + wcp->data_size) &&
588 (pos < wcp->file_size + wcp->alloc_size)) {
589
590 /*
591
592 End of file ---->|
593
594 +---------------+---------------+
595 | Cached data | Cache buffer |
596 +---------------+---------------+
597
598 |<------- allocated size ---------------->|
599
600 +--------+
601 | 1 Byte |
602 +--------+
603
604 MS-Office seems to do this a lot to determine if there's enough
605 space on the filesystem to write a new file.
606
607 Change to :
608
609 End of file ---->|
610 +-----------------------+--------+
611 | Zeroed Cached data | 1 Byte |
612 +-----------------------+--------+
613 */
614
615 flush_write_cache(fsp, WRITE_FLUSH);
616 wcp->offset = wcp->file_size;
617 wcp->data_size = pos - wcp->file_size + 1;
618 memset(wcp->data, '\0', wcp->data_size);
619 memcpy(wcp->data + wcp->data_size-1, data, 1);
620
621 /*
622 * Update the file size if changed.
623 */
624
625 if (wcp->offset + wcp->data_size > wcp->file_size) {
626 if (wcp_file_size_change(fsp) == -1) {
627 return -1;
628 }
629 }
630
631 return n;
632
633 } else {
634
635 /* ASCII art..... JRA.
636
637 Case 1).
638
639 +---------------+---------------+
640 | Cached data | Cache buffer |
641 +---------------+---------------+
642
643 +-------------------+
644 | Data to write |
645 +-------------------+
646
647 Case 2).
648
649 +---------------+---------------+
650 | Cached data | Cache buffer |
651 +---------------+---------------+
652
653 +-------------------+
654 | Data to write |
655 +-------------------+
656
657 Case 3).
658
659 +---------------+---------------+
660 | Cached data | Cache buffer |
661 +---------------+---------------+
662
663 +-----------------------------------------------------+
664 | Data to write |
665 +-----------------------------------------------------+
666
667 */
668
669 /*
670 * Write is bigger than buffer, or there is no overlap on the
671 * low or high ends.
672 */
673
674 DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
675 len = %u\n",fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
676
677 /*
678 * If write would fit in the cache, and is larger than
679 * the data already in the cache, flush the cache and
680 * preferentially copy the data new data into it. Otherwise
681 * just write the data directly.
682 */
683
684 if ( n <= wcp->alloc_size && n > wcp->data_size) {
685 cache_flush_needed = True;
686 } else {
687 ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
688
689 /*
690 * If the write overlaps the entire cache, then
691 * discard the current contents of the cache.
692 * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
693 */
694
695 if ((pos <= wcp->offset) &&
696 (pos + n >= wcp->offset + wcp->data_size) ) {
697 DEBUG(9,("write_file: discarding overwritten write \
698 cache: fd = %d, off=%.0f, size=%u\n", fsp->fh->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
699 wcp->data_size = 0;
700 }
701
702 DO_PROFILE_INC(writecache_direct_writes);
703 if (ret == -1) {
704 return ret;
705 }
706
707 if (pos + ret > wcp->file_size) {
708 wcp->file_size = pos + ret;
709 }
710
711 return ret;
712 }
713
714 write_path = 4;
715
716 }
717
718 if (cache_flush_needed) {
719 DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
720 n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
721 write_path, fsp->fh->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
722 (double)wcp->offset, (unsigned int)wcp->data_size ));
723
724 flush_write_cache(fsp, WRITE_FLUSH);
725 }
726 }
727
728 /*
729 * If the write request is bigger than the cache
730 * size, write it all out.
731 */
732
733 if (n > wcp->alloc_size ) {
734 ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
735 if (ret == -1) {
736 return -1;
737 }
738
739 if (pos + ret > wcp->file_size) {
740 wcp->file_size = pos + n;
741 }
742
743 DO_PROFILE_INC(writecache_direct_writes);
744 return total_written + n;
745 }
746
747 /*
748 * If there's any data left, cache it.
749 */
750
751 if (n) {
752 #ifdef WITH_PROFILE
753 if (wcp->data_size) {
754 DO_PROFILE_INC(writecache_abutted_writes);
755 } else {
756 DO_PROFILE_INC(writecache_init_writes);
757 }
758 #endif
759 memcpy(wcp->data+wcp->data_size, data, n);
760 if (wcp->data_size == 0) {
761 wcp->offset = pos;
762 DO_PROFILE_INC(writecache_num_write_caches);
763 }
764 wcp->data_size += n;
765
766 /*
767 * Update the file size if changed.
768 */
769
770 if (wcp->offset + wcp->data_size > wcp->file_size) {
771 if (wcp_file_size_change(fsp) == -1) {
772 return -1;
773 }
774 }
775 DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
776 (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
777
778 total_written += n;
779 return total_written; /* .... that's a write :) */
780 }
781
782 return total_written;
783 }
784
785 /****************************************************************************
786 Delete the write cache structure.
787 ****************************************************************************/
788
789 void delete_write_cache(files_struct *fsp)
790 {
791 write_cache *wcp;
792
793 if(!fsp) {
794 return;
795 }
796
797 if(!(wcp = fsp->wcp)) {
798 return;
799 }
800
801 DO_PROFILE_DEC(writecache_allocated_write_caches);
802 allocated_write_caches--;
803
804 SMB_ASSERT(wcp->data_size == 0);
805
806 SAFE_FREE(wcp->data);
807 SAFE_FREE(fsp->wcp);
808
809 DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
810 }
811
812 /****************************************************************************
813 Setup the write cache structure.
814 ****************************************************************************/
815
816 static bool setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
817 {
818 ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
819 write_cache *wcp;
820
821 if (allocated_write_caches >= MAX_WRITE_CACHES) {
822 return False;
823 }
824
825 if(alloc_size == 0 || fsp->wcp) {
826 return False;
827 }
828
829 if((wcp = SMB_MALLOC_P(write_cache)) == NULL) {
830 DEBUG(0,("setup_write_cache: malloc fail.\n"));
831 return False;
832 }
833
834 wcp->file_size = file_size;
835 wcp->offset = 0;
836 wcp->alloc_size = alloc_size;
837 wcp->data_size = 0;
838 if((wcp->data = (char *)SMB_MALLOC(wcp->alloc_size)) == NULL) {
839 DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
840 (unsigned int)wcp->alloc_size ));
841 SAFE_FREE(wcp);
842 return False;
843 }
844
845 memset(wcp->data, '\0', wcp->alloc_size );
846
847 fsp->wcp = wcp;
848 DO_PROFILE_INC(writecache_allocated_write_caches);
849 allocated_write_caches++;
850
851 DEBUG(10,("setup_write_cache: File %s allocated write cache size %lu\n",
852 fsp->fsp_name, (unsigned long)wcp->alloc_size ));
853
854 return True;
855 }
856
857 /****************************************************************************
858 Cope with a size change.
859 ****************************************************************************/
860
861 void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
862 {
863 if(fsp->wcp) {
864 /* The cache *must* have been flushed before we do this. */
865 if (fsp->wcp->data_size != 0) {
866 char *msg;
867 if (asprintf(&msg, "set_filelen_write_cache: size change "
868 "on file %s with write cache size = %lu\n",
869 fsp->fsp_name,
870 (unsigned long)fsp->wcp->data_size) != -1) {
871 smb_panic(msg);
872 } else {
873 smb_panic("set_filelen_write_cache");
874 }
875 }
876 fsp->wcp->file_size = file_size;
877 }
878 }
879
880 /*******************************************************************
881 Flush a write cache struct to disk.
882 ********************************************************************/
883
884 ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
885 {
886 write_cache *wcp = fsp->wcp;
887 size_t data_size;
888 ssize_t ret;
889
890 if(!wcp || !wcp->data_size) {
891 return 0;
892 }
893
894 data_size = wcp->data_size;
895 wcp->data_size = 0;
896
897 DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
898
899 DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
900 fsp->fh->fd, (double)wcp->offset, (unsigned int)data_size));
901
902 #ifdef WITH_PROFILE
903 if(data_size == wcp->alloc_size) {
904 DO_PROFILE_INC(writecache_num_perfect_writes);
905 }
906 #endif
907
908 ret = real_write_file(NULL, fsp, wcp->data, wcp->offset, data_size);
909
910 /*
911 * Ensure file size if kept up to date if write extends file.
912 */
913
914 if ((ret != -1) && (wcp->offset + ret > wcp->file_size)) {
915 wcp->file_size = wcp->offset + ret;
916 }
917
918 return ret;
919 }
920
921 /*******************************************************************
922 sync a file
923 ********************************************************************/
924
925 NTSTATUS sync_file(connection_struct *conn, files_struct *fsp, bool write_through)
926 {
927 if (fsp->fh->fd == -1)
928 return NT_STATUS_INVALID_HANDLE;
929
930 if (lp_strict_sync(SNUM(conn)) &&
931 (lp_syncalways(SNUM(conn)) || write_through)) {
932 int ret = flush_write_cache(fsp, SYNC_FLUSH);
933 if (ret == -1) {
934 return map_nt_error_from_unix(errno);
935 }
936 ret = SMB_VFS_FSYNC(fsp);
937 if (ret == -1) {
938 return map_nt_error_from_unix(errno);
939 }
940 }
941 return NT_STATUS_OK;
942 }
943
944 /************************************************************
945 Perform a stat whether a valid fd or not.
946 ************************************************************/
947
948 int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
949 {
950 if (fsp->fh->fd == -1) {
951 return SMB_VFS_STAT(fsp->conn, fsp->fsp_name, pst);
952 } else {
953 return SMB_VFS_FSTAT(fsp, pst);
954 }
955 }
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