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s3:configure: search fdatasync also in librt
[Samba/ekacnet.git] / source3 / smbd / fileio.c
blob92b7d3ed9ea0a6ead0103ac28d2a9d784f985210
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 errno = EBADF;
61 return -1;
62 }
63
64 /*
65 * Serve from write cache if we can.
66 */
67
68 if(read_from_write_cache(fsp, data, pos, n)) {
69 fsp->fh->pos = pos + n;
70 fsp->fh->position_information = fsp->fh->pos;
71 return n;
72 }
73
74 flush_write_cache(fsp, READ_FLUSH);
75
76 fsp->fh->pos = pos;
77
78 if (n > 0) {
79 #ifdef DMF_FIX
80 int numretries = 3;
81 tryagain:
82 readret = SMB_VFS_PREAD(fsp,data,n,pos);
83
84 if (readret == -1) {
85 if ((errno == EAGAIN) && numretries) {
86 DEBUG(3,("read_file EAGAIN retry in 10 seconds\n"));
87 (void)sleep(10);
88 --numretries;
89 goto tryagain;
90 }
91 return -1;
92 }
93 #else /* NO DMF fix. */
94 readret = SMB_VFS_PREAD(fsp,data,n,pos);
95
96 if (readret == -1) {
97 return -1;
98 }
99 #endif
100 if (readret > 0) {
101 ret += readret;
102 }
103 }
104
105 DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
106 fsp_str_dbg(fsp), (double)pos, (unsigned long)n, (long)ret));
107
108 fsp->fh->pos += ret;
109 fsp->fh->position_information = fsp->fh->pos;
110
111 return(ret);
112 }
113
114 /****************************************************************************
115 *Really* write to a file.
116 ****************************************************************************/
117
118 static ssize_t real_write_file(struct smb_request *req,
119 files_struct *fsp,
120 const char *data,
121 SMB_OFF_T pos,
122 size_t n)
123 {
124 ssize_t ret;
125
126 if (pos == -1) {
127 ret = vfs_write_data(req, fsp, data, n);
128 } else {
129 fsp->fh->pos = pos;
130 if (pos && lp_strict_allocate(SNUM(fsp->conn))) {
131 if (vfs_fill_sparse(fsp, pos) == -1) {
132 return -1;
133 }
134 }
135 ret = vfs_pwrite_data(req, fsp, data, n, pos);
136 }
137
138 DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
139 fsp_str_dbg(fsp), (double)pos, (unsigned long)n, (long)ret));
140
141 if (ret != -1) {
142 fsp->fh->pos += ret;
143
144 /* Yes - this is correct - writes don't update this. JRA. */
145 /* Found by Samba4 tests. */
146 #if 0
147 fsp->position_information = fsp->pos;
148 #endif
149 }
150
151 return ret;
152 }
153
154 /****************************************************************************
155 File size cache change.
156 Updates size on disk but doesn't flush the cache.
157 ****************************************************************************/
158
159 static int wcp_file_size_change(files_struct *fsp)
160 {
161 int ret;
162 write_cache *wcp = fsp->wcp;
163
164 wcp->file_size = wcp->offset + wcp->data_size;
165 ret = SMB_VFS_FTRUNCATE(fsp, wcp->file_size);
166 if (ret == -1) {
167 DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f "
168 "error %s\n", fsp_str_dbg(fsp),
169 (double)wcp->file_size, strerror(errno)));
170 }
171 return ret;
172 }
173
174 void update_write_time_handler(struct event_context *ctx,
175 struct timed_event *te,
176 struct timeval now,
177 void *private_data)
178 {
179 files_struct *fsp = (files_struct *)private_data;
180
181 DEBUG(5, ("Update write time on %s\n", fsp_str_dbg(fsp)));
182
183 /* change the write time in the open file db. */
184 (void)set_write_time(fsp->file_id, timespec_current());
185
186 /* And notify. */
187 notify_fname(fsp->conn, NOTIFY_ACTION_MODIFIED,
188 FILE_NOTIFY_CHANGE_LAST_WRITE, fsp->fsp_name->base_name);
189
190 /* Remove the timed event handler. */
191 TALLOC_FREE(fsp->update_write_time_event);
192 }
193
194 /*********************************************************
195 Schedule a write time update for WRITE_TIME_UPDATE_USEC_DELAY
196 in the future.
197 *********************************************************/
198
199 void trigger_write_time_update(struct files_struct *fsp)
200 {
201 int delay;
202
203 if (fsp->posix_open) {
204 /* Don't use delayed writes on POSIX files. */
205 return;
206 }
207
208 if (fsp->write_time_forced) {
209 /* No point - "sticky" write times
210 * in effect.
211 */
212 return;
213 }
214
215 /* We need to remember someone did a write
216 * and update to current time on close. */
217
218 fsp->update_write_time_on_close = true;
219
220 if (fsp->update_write_time_triggered) {
221 /*
222 * We only update the write time after 2 seconds
223 * on the first normal write. After that
224 * no other writes affect this until close.
225 */
226 return;
227 }
228 fsp->update_write_time_triggered = true;
229
230 delay = lp_parm_int(SNUM(fsp->conn),
231 "smbd", "writetimeupdatedelay",
232 WRITE_TIME_UPDATE_USEC_DELAY);
233
234 DEBUG(5, ("Update write time %d usec later on %s\n",
235 delay, fsp_str_dbg(fsp)));
236
237 /* trigger the update 2 seconds later */
238 fsp->update_write_time_event =
239 event_add_timed(smbd_event_context(), NULL,
240 timeval_current_ofs(0, delay),
241 update_write_time_handler, fsp);
242 }
243
244 void trigger_write_time_update_immediate(struct files_struct *fsp)
245 {
246 struct smb_file_time ft;
247
248 if (fsp->posix_open) {
249 /* Don't use delayed writes on POSIX files. */
250 return;
251 }
252
253 if (fsp->write_time_forced) {
254 /*
255 * No point - "sticky" write times
256 * in effect.
257 */
258 return;
259 }
260
261 TALLOC_FREE(fsp->update_write_time_event);
262 DEBUG(5, ("Update write time immediate on %s\n",
263 fsp_str_dbg(fsp)));
264
265 /* After an immediate update, reset the trigger. */
266 fsp->update_write_time_triggered = true;
267 fsp->update_write_time_on_close = false;
268
269 ZERO_STRUCT(ft);
270 ft.mtime = timespec_current();
271
272 /* Update the time in the open file db. */
273 (void)set_write_time(fsp->file_id, ft.mtime);
274
275 /* Now set on disk - takes care of notify. */
276 (void)smb_set_file_time(fsp->conn, fsp, fsp->fsp_name, &ft, false);
277 }
278
279 /****************************************************************************
280 Write to a file.
281 ****************************************************************************/
282
283 ssize_t write_file(struct smb_request *req,
284 files_struct *fsp,
285 const char *data,
286 SMB_OFF_T pos,
287 size_t n)
288 {
289 write_cache *wcp = fsp->wcp;
290 ssize_t total_written = 0;
291 int write_path = -1;
292
293 if (fsp->print_file) {
294 uint32 jobid;
295
296 if (!rap_to_pjobid(fsp->print_file->rap_jobid, NULL, &jobid)) {
297 DEBUG(3, ("write_file: "
298 "Unable to map RAP jobid %u to jobid.\n",
299 (unsigned int)fsp->print_file->rap_jobid));
300 errno = EBADF;
301 return -1;
302 }
303
304 /* support seeks for print files bigger than 4G */
305 pos = printfile_offset(fsp, pos);
306
307 return print_job_write(SNUM(fsp->conn), jobid, data, pos, n);
308 }
309
310 if (!fsp->can_write) {
311 errno = EPERM;
312 return -1;
313 }
314
315 if (!fsp->modified) {
316 fsp->modified = True;
317
318 if (SMB_VFS_FSTAT(fsp, &fsp->fsp_name->st) == 0) {
319 int dosmode;
320 trigger_write_time_update(fsp);
321 dosmode = dos_mode(fsp->conn, fsp->fsp_name);
322 if ((lp_store_dos_attributes(SNUM(fsp->conn)) ||
323 MAP_ARCHIVE(fsp->conn)) &&
324 !IS_DOS_ARCHIVE(dosmode)) {
325 file_set_dosmode(fsp->conn, fsp->fsp_name,
326 dosmode | aARCH, NULL, false);
327 }
328
329 /*
330 * If this is the first write and we have an exclusive oplock then setup
331 * the write cache.
332 */
333
334 if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
335 setup_write_cache(fsp,
336 fsp->fsp_name->st.st_ex_size);
337 wcp = fsp->wcp;
338 }
339 }
340 }
341
342 #ifdef WITH_PROFILE
343 DO_PROFILE_INC(writecache_total_writes);
344 if (!fsp->oplock_type) {
345 DO_PROFILE_INC(writecache_non_oplock_writes);
346 }
347 #endif
348
349 /*
350 * If this file is level II oplocked then we need
351 * to grab the shared memory lock and inform all
352 * other files with a level II lock that they need
353 * to flush their read caches. We keep the lock over
354 * the shared memory area whilst doing this.
355 */
356
357 /* This should actually be improved to span the write. */
358 contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WRITE);
359 contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WRITE);
360
361 #ifdef WITH_PROFILE
362 if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
363 DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
364 nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
365 profile_p->writecache_init_writes,
366 profile_p->writecache_abutted_writes,
367 profile_p->writecache_total_writes,
368 profile_p->writecache_non_oplock_writes,
369 profile_p->writecache_allocated_write_caches,
370 profile_p->writecache_num_write_caches,
371 profile_p->writecache_direct_writes,
372 profile_p->writecache_num_perfect_writes,
373 profile_p->writecache_read_hits ));
374
375 DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
376 profile_p->writecache_flushed_writes[SEEK_FLUSH],
377 profile_p->writecache_flushed_writes[READ_FLUSH],
378 profile_p->writecache_flushed_writes[WRITE_FLUSH],
379 profile_p->writecache_flushed_writes[READRAW_FLUSH],
380 profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
381 profile_p->writecache_flushed_writes[CLOSE_FLUSH],
382 profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
383 }
384 #endif
385
386 if (wcp && req->unread_bytes) {
387 /* If we're using receivefile don't
388 * deal with a write cache.
389 */
390 flush_write_cache(fsp, WRITE_FLUSH);
391 delete_write_cache(fsp);
392 wcp = NULL;
393 }
394
395 if(!wcp) {
396 DO_PROFILE_INC(writecache_direct_writes);
397 total_written = real_write_file(req, fsp, data, pos, n);
398 return total_written;
399 }
400
401 DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f "
402 "wcp->data_size=%u\n", fsp_str_dbg(fsp), fsp->fh->fd,
403 (double)pos, (unsigned int)n, (double)wcp->offset,
404 (unsigned int)wcp->data_size));
405
406 fsp->fh->pos = pos + n;
407
408 /*
409 * If we have active cache and it isn't contiguous then we flush.
410 * NOTE: There is a small problem with running out of disk ....
411 */
412
413 if (wcp->data_size) {
414 bool cache_flush_needed = False;
415
416 if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
417
418 /* ASCII art.... JRA.
419
420 +--------------+-----
421 | Cached data | Rest of allocated cache buffer....
422 +--------------+-----
423
424 +-------------------+
425 | Data to write |
426 +-------------------+
427
428 */
429
430 /*
431 * Start of write overlaps or abutts the existing data.
432 */
433
434 size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
435
436 memcpy(wcp->data + (pos - wcp->offset), data, data_used);
437
438 /*
439 * Update the current buffer size with the new data.
440 */
441
442 if(pos + data_used > wcp->offset + wcp->data_size) {
443 wcp->data_size = pos + data_used - wcp->offset;
444 }
445
446 /*
447 * Update the file size if changed.
448 */
449
450 if (wcp->offset + wcp->data_size > wcp->file_size) {
451 if (wcp_file_size_change(fsp) == -1) {
452 return -1;
453 }
454 }
455
456 /*
457 * If we used all the data then
458 * return here.
459 */
460
461 if(n == data_used) {
462 return n;
463 } else {
464 cache_flush_needed = True;
465 }
466 /*
467 * Move the start of data forward by the amount used,
468 * cut down the amount left by the same amount.
469 */
470
471 data += data_used;
472 pos += data_used;
473 n -= data_used;
474
475 DO_PROFILE_INC(writecache_abutted_writes);
476 total_written = data_used;
477
478 write_path = 1;
479
480 } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
481 (pos + n <= wcp->offset + wcp->alloc_size)) {
482
483 /* ASCII art.... JRA.
484
485 +---------------+
486 | Cache buffer |
487 +---------------+
488
489 +-------------------+
490 | Data to write |
491 +-------------------+
492
493 */
494
495 /*
496 * End of write overlaps the existing data.
497 */
498
499 size_t data_used = pos + n - wcp->offset;
500
501 memcpy(wcp->data, data + n - data_used, data_used);
502
503 /*
504 * Update the current buffer size with the new data.
505 */
506
507 if(pos + n > wcp->offset + wcp->data_size) {
508 wcp->data_size = pos + n - wcp->offset;
509 }
510
511 /*
512 * Update the file size if changed.
513 */
514
515 if (wcp->offset + wcp->data_size > wcp->file_size) {
516 if (wcp_file_size_change(fsp) == -1) {
517 return -1;
518 }
519 }
520
521 /*
522 * We don't need to move the start of data, but we
523 * cut down the amount left by the amount used.
524 */
525
526 n -= data_used;
527
528 /*
529 * We cannot have used all the data here.
530 */
531
532 cache_flush_needed = True;
533
534 DO_PROFILE_INC(writecache_abutted_writes);
535 total_written = data_used;
536
537 write_path = 2;
538
539 } else if ( (pos >= wcp->file_size) &&
540 (wcp->offset + wcp->data_size == wcp->file_size) &&
541 (pos > wcp->offset + wcp->data_size) &&
542 (pos < wcp->offset + wcp->alloc_size) ) {
543
544 /* ASCII art.... JRA.
545
546 End of file ---->|
547
548 +---------------+---------------+
549 | Cached data | Cache buffer |
550 +---------------+---------------+
551
552 +-------------------+
553 | Data to write |
554 +-------------------+
555
556 */
557
558 /*
559 * Non-contiguous write part of which fits within
560 * the cache buffer and is extending the file
561 * and the cache contents reflect the current
562 * data up to the current end of the file.
563 */
564
565 size_t data_used;
566
567 if(pos + n <= wcp->offset + wcp->alloc_size) {
568 data_used = n;
569 } else {
570 data_used = wcp->offset + wcp->alloc_size - pos;
571 }
572
573 /*
574 * Fill in the non-continuous area with zeros.
575 */
576
577 memset(wcp->data + wcp->data_size, '\0',
578 pos - (wcp->offset + wcp->data_size) );
579
580 memcpy(wcp->data + (pos - wcp->offset), data, data_used);
581
582 /*
583 * Update the current buffer size with the new data.
584 */
585
586 if(pos + data_used > wcp->offset + wcp->data_size) {
587 wcp->data_size = pos + data_used - wcp->offset;
588 }
589
590 /*
591 * Update the file size if changed.
592 */
593
594 if (wcp->offset + wcp->data_size > wcp->file_size) {
595 if (wcp_file_size_change(fsp) == -1) {
596 return -1;
597 }
598 }
599
600 /*
601 * If we used all the data then
602 * return here.
603 */
604
605 if(n == data_used) {
606 return n;
607 } else {
608 cache_flush_needed = True;
609 }
610
611 /*
612 * Move the start of data forward by the amount used,
613 * cut down the amount left by the same amount.
614 */
615
616 data += data_used;
617 pos += data_used;
618 n -= data_used;
619
620 DO_PROFILE_INC(writecache_abutted_writes);
621 total_written = data_used;
622
623 write_path = 3;
624
625 } else if ( (pos >= wcp->file_size) &&
626 (n == 1) &&
627 (wcp->file_size == wcp->offset + wcp->data_size) &&
628 (pos < wcp->file_size + wcp->alloc_size)) {
629
630 /*
631
632 End of file ---->|
633
634 +---------------+---------------+
635 | Cached data | Cache buffer |
636 +---------------+---------------+
637
638 |<------- allocated size ---------------->|
639
640 +--------+
641 | 1 Byte |
642 +--------+
643
644 MS-Office seems to do this a lot to determine if there's enough
645 space on the filesystem to write a new file.
646
647 Change to :
648
649 End of file ---->|
650 +-----------------------+--------+
651 | Zeroed Cached data | 1 Byte |
652 +-----------------------+--------+
653 */
654
655 flush_write_cache(fsp, WRITE_FLUSH);
656 wcp->offset = wcp->file_size;
657 wcp->data_size = pos - wcp->file_size + 1;
658 memset(wcp->data, '\0', wcp->data_size);
659 memcpy(wcp->data + wcp->data_size-1, data, 1);
660
661 /*
662 * Update the file size if changed.
663 */
664
665 if (wcp->offset + wcp->data_size > wcp->file_size) {
666 if (wcp_file_size_change(fsp) == -1) {
667 return -1;
668 }
669 }
670
671 return n;
672
673 } else {
674
675 /* ASCII art..... JRA.
676
677 Case 1).
678
679 +---------------+---------------+
680 | Cached data | Cache buffer |
681 +---------------+---------------+
682
683 +-------------------+
684 | Data to write |
685 +-------------------+
686
687 Case 2).
688
689 +---------------+---------------+
690 | Cached data | Cache buffer |
691 +---------------+---------------+
692
693 +-------------------+
694 | Data to write |
695 +-------------------+
696
697 Case 3).
698
699 +---------------+---------------+
700 | Cached data | Cache buffer |
701 +---------------+---------------+
702
703 +-----------------------------------------------------+
704 | Data to write |
705 +-----------------------------------------------------+
706
707 */
708
709 /*
710 * Write is bigger than buffer, or there is no overlap on the
711 * low or high ends.
712 */
713
714 DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
715 len = %u\n",fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
716
717 /*
718 * If write would fit in the cache, and is larger than
719 * the data already in the cache, flush the cache and
720 * preferentially copy the data new data into it. Otherwise
721 * just write the data directly.
722 */
723
724 if ( n <= wcp->alloc_size && n > wcp->data_size) {
725 cache_flush_needed = True;
726 } else {
727 ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
728
729 /*
730 * If the write overlaps the entire cache, then
731 * discard the current contents of the cache.
732 * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
733 */
734
735 if ((pos <= wcp->offset) &&
736 (pos + n >= wcp->offset + wcp->data_size) ) {
737 DEBUG(9,("write_file: discarding overwritten write \
738 cache: fd = %d, off=%.0f, size=%u\n", fsp->fh->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
739 wcp->data_size = 0;
740 }
741
742 DO_PROFILE_INC(writecache_direct_writes);
743 if (ret == -1) {
744 return ret;
745 }
746
747 if (pos + ret > wcp->file_size) {
748 wcp->file_size = pos + ret;
749 }
750
751 return ret;
752 }
753
754 write_path = 4;
755
756 }
757
758 if (cache_flush_needed) {
759 DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
760 n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
761 write_path, fsp->fh->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
762 (double)wcp->offset, (unsigned int)wcp->data_size ));
763
764 flush_write_cache(fsp, WRITE_FLUSH);
765 }
766 }
767
768 /*
769 * If the write request is bigger than the cache
770 * size, write it all out.
771 */
772
773 if (n > wcp->alloc_size ) {
774 ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
775 if (ret == -1) {
776 return -1;
777 }
778
779 if (pos + ret > wcp->file_size) {
780 wcp->file_size = pos + n;
781 }
782
783 DO_PROFILE_INC(writecache_direct_writes);
784 return total_written + n;
785 }
786
787 /*
788 * If there's any data left, cache it.
789 */
790
791 if (n) {
792 #ifdef WITH_PROFILE
793 if (wcp->data_size) {
794 DO_PROFILE_INC(writecache_abutted_writes);
795 } else {
796 DO_PROFILE_INC(writecache_init_writes);
797 }
798 #endif
799 memcpy(wcp->data+wcp->data_size, data, n);
800 if (wcp->data_size == 0) {
801 wcp->offset = pos;
802 DO_PROFILE_INC(writecache_num_write_caches);
803 }
804 wcp->data_size += n;
805
806 /*
807 * Update the file size if changed.
808 */
809
810 if (wcp->offset + wcp->data_size > wcp->file_size) {
811 if (wcp_file_size_change(fsp) == -1) {
812 return -1;
813 }
814 }
815 DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
816 (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
817
818 total_written += n;
819 return total_written; /* .... that's a write :) */
820 }
821
822 return total_written;
823 }
824
825 /****************************************************************************
826 Delete the write cache structure.
827 ****************************************************************************/
828
829 void delete_write_cache(files_struct *fsp)
830 {
831 write_cache *wcp;
832
833 if(!fsp) {
834 return;
835 }
836
837 if(!(wcp = fsp->wcp)) {
838 return;
839 }
840
841 DO_PROFILE_DEC(writecache_allocated_write_caches);
842 allocated_write_caches--;
843
844 SMB_ASSERT(wcp->data_size == 0);
845
846 SAFE_FREE(wcp->data);
847 SAFE_FREE(fsp->wcp);
848
849 DEBUG(10,("delete_write_cache: File %s deleted write cache\n",
850 fsp_str_dbg(fsp)));
851 }
852
853 /****************************************************************************
854 Setup the write cache structure.
855 ****************************************************************************/
856
857 static bool setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
858 {
859 ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
860 write_cache *wcp;
861
862 if (allocated_write_caches >= MAX_WRITE_CACHES) {
863 return False;
864 }
865
866 if(alloc_size == 0 || fsp->wcp) {
867 return False;
868 }
869
870 if((wcp = SMB_MALLOC_P(write_cache)) == NULL) {
871 DEBUG(0,("setup_write_cache: malloc fail.\n"));
872 return False;
873 }
874
875 wcp->file_size = file_size;
876 wcp->offset = 0;
877 wcp->alloc_size = alloc_size;
878 wcp->data_size = 0;
879 if((wcp->data = (char *)SMB_MALLOC(wcp->alloc_size)) == NULL) {
880 DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
881 (unsigned int)wcp->alloc_size ));
882 SAFE_FREE(wcp);
883 return False;
884 }
885
886 memset(wcp->data, '\0', wcp->alloc_size );
887
888 fsp->wcp = wcp;
889 DO_PROFILE_INC(writecache_allocated_write_caches);
890 allocated_write_caches++;
891
892 DEBUG(10,("setup_write_cache: File %s allocated write cache size %lu\n",
893 fsp_str_dbg(fsp), (unsigned long)wcp->alloc_size));
894
895 return True;
896 }
897
898 /****************************************************************************
899 Cope with a size change.
900 ****************************************************************************/
901
902 void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
903 {
904 if(fsp->wcp) {
905 /* The cache *must* have been flushed before we do this. */
906 if (fsp->wcp->data_size != 0) {
907 char *msg;
908 if (asprintf(&msg, "set_filelen_write_cache: size change "
909 "on file %s with write cache size = %lu\n",
910 fsp->fsp_name->base_name,
911 (unsigned long)fsp->wcp->data_size) != -1) {
912 smb_panic(msg);
913 } else {
914 smb_panic("set_filelen_write_cache");
915 }
916 }
917 fsp->wcp->file_size = file_size;
918 }
919 }
920
921 /*******************************************************************
922 Flush a write cache struct to disk.
923 ********************************************************************/
924
925 ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
926 {
927 write_cache *wcp = fsp->wcp;
928 size_t data_size;
929 ssize_t ret;
930
931 if(!wcp || !wcp->data_size) {
932 return 0;
933 }
934
935 data_size = wcp->data_size;
936 wcp->data_size = 0;
937
938 DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
939
940 DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
941 fsp->fh->fd, (double)wcp->offset, (unsigned int)data_size));
942
943 #ifdef WITH_PROFILE
944 if(data_size == wcp->alloc_size) {
945 DO_PROFILE_INC(writecache_num_perfect_writes);
946 }
947 #endif
948
949 ret = real_write_file(NULL, fsp, wcp->data, wcp->offset, data_size);
950
951 /*
952 * Ensure file size if kept up to date if write extends file.
953 */
954
955 if ((ret != -1) && (wcp->offset + ret > wcp->file_size)) {
956 wcp->file_size = wcp->offset + ret;
957 }
958
959 return ret;
960 }
961
962 /*******************************************************************
963 sync a file
964 ********************************************************************/
965
966 NTSTATUS sync_file(connection_struct *conn, files_struct *fsp, bool write_through)
967 {
968 if (fsp->fh->fd == -1)
969 return NT_STATUS_INVALID_HANDLE;
970
971 if (lp_strict_sync(SNUM(conn)) &&
972 (lp_syncalways(SNUM(conn)) || write_through)) {
973 int ret = flush_write_cache(fsp, SYNC_FLUSH);
974 if (ret == -1) {
975 return map_nt_error_from_unix(errno);
976 }
977 ret = SMB_VFS_FSYNC(fsp);
978 if (ret == -1) {
979 return map_nt_error_from_unix(errno);
980 }
981 }
982 return NT_STATUS_OK;
983 }
984
985 /************************************************************
986 Perform a stat whether a valid fd or not.
987 ************************************************************/
988
989 int fsp_stat(files_struct *fsp)
990 {
991 if (fsp->fh->fd == -1) {
992 if (fsp->posix_open) {
993 return SMB_VFS_LSTAT(fsp->conn, fsp->fsp_name);
994 } else {
995 return SMB_VFS_STAT(fsp->conn, fsp->fsp_name);
996 }
997 } else {
998 return SMB_VFS_FSTAT(fsp, &fsp->fsp_name->st);
999 }
1000 }