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 2 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, write to the Free Software
20   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21*/
22
23#include "includes.h"
24
25static BOOL setup_write_cache(files_struct *, SMB_OFF_T);
26
27/****************************************************************************
28 Read from write cache if we can.
29****************************************************************************/
30
31static 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
54ssize_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;
80tryagain:
81		readret = SMB_VFS_PREAD(fsp,fsp->fh->fd,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,fsp->fh->fd,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/* how many write cache buffers have been allocated */
114static unsigned int allocated_write_caches;
115
116/****************************************************************************
117 *Really* write to a file.
118****************************************************************************/
119
120static ssize_t real_write_file(files_struct *fsp,const char *data, SMB_OFF_T pos, size_t n)
121{
122	ssize_t ret;
123
124        if (pos == -1) {
125                ret = vfs_write_data(fsp, data, n);
126        } else {
127		fsp->fh->pos = pos;
128		if (pos && lp_strict_allocate(SNUM(fsp->conn))) {
129			if (vfs_fill_sparse(fsp, pos) == -1) {
130				return -1;
131			}
132		}
133                ret = vfs_pwrite_data(fsp, data, n, pos);
134	}
135
136	DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
137		fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
138
139	if (ret != -1) {
140		fsp->fh->pos += ret;
141
142		/*
143		 * It turns out that setting the last write time from a Windows
144		 * client stops any subsequent writes from updating the write time.
145		 * Doing this after the write gives a race condition here where
146		 * a stat may see the changed write time before we reset it here,
147		 * but it's cheaper than having to store the write time in shared
148		 * memory and look it up using dev/inode across all running smbd's.
149		 * The 99% solution will hopefully be good enough in this case. JRA.
150		 */
151
152		if (!null_timespec(fsp->pending_modtime)) {
153			set_filetime(fsp->conn, fsp->fsp_name, fsp->pending_modtime);
154
155			/* If we didn't get the "set modtime" call ourselves, we must
156			   store the last write time to restore on close. JRA. */
157			if (!fsp->pending_modtime_owner) {
158				fsp->last_write_time = timespec_current();
159			}
160		}
161
162/* Yes - this is correct - writes don't update this. JRA. */
163/* Found by Samba4 tests. */
164#if 0
165		fsp->position_information = fsp->pos;
166#endif
167	}
168
169	return ret;
170}
171
172/****************************************************************************
173 File size cache change.
174 Updates size on disk but doesn't flush the cache.
175****************************************************************************/
176
177static int wcp_file_size_change(files_struct *fsp)
178{
179	int ret;
180	write_cache *wcp = fsp->wcp;
181
182	wcp->file_size = wcp->offset + wcp->data_size;
183	ret = SMB_VFS_FTRUNCATE(fsp, fsp->fh->fd, wcp->file_size);
184	if (ret == -1) {
185		DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f error %s\n",
186			fsp->fsp_name, (double)wcp->file_size, strerror(errno) ));
187	}
188	return ret;
189}
190
191/****************************************************************************
192 Write to a file.
193****************************************************************************/
194
195ssize_t write_file(files_struct *fsp, const char *data, SMB_OFF_T pos, size_t n)
196{
197	write_cache *wcp = fsp->wcp;
198	ssize_t total_written = 0;
199	int write_path = -1;
200
201	if (fsp->print_file) {
202		fstring sharename;
203		uint32 jobid;
204
205		if (!rap_to_pjobid(fsp->rap_print_jobid, sharename, &jobid)) {
206			DEBUG(3,("write_file: Unable to map RAP jobid %u to jobid.\n",
207						(unsigned int)fsp->rap_print_jobid ));
208			errno = EBADF;
209			return -1;
210		}
211
212		return print_job_write(SNUM(fsp->conn), jobid, data, pos, n);
213	}
214
215	if (!fsp->can_write) {
216		errno = EPERM;
217		return -1;
218	}
219
220	if (!fsp->modified) {
221		SMB_STRUCT_STAT st;
222		fsp->modified = True;
223
224		if (SMB_VFS_FSTAT(fsp,fsp->fh->fd,&st) == 0) {
225			int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
226			if ((lp_store_dos_attributes(SNUM(fsp->conn)) || MAP_ARCHIVE(fsp->conn)) && !IS_DOS_ARCHIVE(dosmode)) {
227				file_set_dosmode(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st, False);
228			}
229
230			/*
231			 * If this is the first write and we have an exclusive oplock then setup
232			 * the write cache.
233			 */
234
235			if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
236				setup_write_cache(fsp, st.st_size);
237				wcp = fsp->wcp;
238			}
239		}
240	}
241
242#ifdef WITH_PROFILE
243	DO_PROFILE_INC(writecache_total_writes);
244	if (!fsp->oplock_type) {
245		DO_PROFILE_INC(writecache_non_oplock_writes);
246	}
247#endif
248
249	/*
250	 * If this file is level II oplocked then we need
251	 * to grab the shared memory lock and inform all
252	 * other files with a level II lock that they need
253	 * to flush their read caches. We keep the lock over
254	 * the shared memory area whilst doing this.
255	 */
256
257	release_level_2_oplocks_on_change(fsp);
258
259#ifdef WITH_PROFILE
260	if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
261		DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
262nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
263			profile_p->writecache_init_writes,
264			profile_p->writecache_abutted_writes,
265			profile_p->writecache_total_writes,
266			profile_p->writecache_non_oplock_writes,
267			profile_p->writecache_allocated_write_caches,
268			profile_p->writecache_num_write_caches,
269			profile_p->writecache_direct_writes,
270			profile_p->writecache_num_perfect_writes,
271			profile_p->writecache_read_hits ));
272
273		DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
274			profile_p->writecache_flushed_writes[SEEK_FLUSH],
275			profile_p->writecache_flushed_writes[READ_FLUSH],
276			profile_p->writecache_flushed_writes[WRITE_FLUSH],
277			profile_p->writecache_flushed_writes[READRAW_FLUSH],
278			profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
279			profile_p->writecache_flushed_writes[CLOSE_FLUSH],
280			profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
281	}
282#endif
283
284	if(!wcp) {
285		DO_PROFILE_INC(writecache_direct_writes);
286		total_written = real_write_file(fsp, data, pos, n);
287		return total_written;
288	}
289
290	DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f wcp->data_size=%u\n",
291		fsp->fsp_name, fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size));
292
293	fsp->fh->pos = pos + n;
294
295	/*
296	 * If we have active cache and it isn't contiguous then we flush.
297	 * NOTE: There is a small problem with running out of disk ....
298	 */
299
300	if (wcp->data_size) {
301		BOOL cache_flush_needed = False;
302
303		if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
304
305			/* ASCII art.... JRA.
306
307      +--------------+-----
308      | Cached data  | Rest of allocated cache buffer....
309      +--------------+-----
310
311            +-------------------+
312            | Data to write     |
313            +-------------------+
314
315	    		*/
316
317			/*
318			 * Start of write overlaps or abutts the existing data.
319			 */
320
321			size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
322
323			memcpy(wcp->data + (pos - wcp->offset), data, data_used);
324
325			/*
326			 * Update the current buffer size with the new data.
327			 */
328
329			if(pos + data_used > wcp->offset + wcp->data_size) {
330				wcp->data_size = pos + data_used - wcp->offset;
331			}
332
333			/*
334			 * Update the file size if changed.
335			 */
336
337			if (wcp->offset + wcp->data_size > wcp->file_size) {
338				if (wcp_file_size_change(fsp) == -1) {
339					return -1;
340				}
341			}
342
343			/*
344			 * If we used all the data then
345			 * return here.
346			 */
347
348			if(n == data_used) {
349				return n;
350			} else {
351				cache_flush_needed = True;
352			}
353			/*
354			 * Move the start of data forward by the amount used,
355			 * cut down the amount left by the same amount.
356			 */
357
358			data += data_used;
359			pos += data_used;
360			n -= data_used;
361
362			DO_PROFILE_INC(writecache_abutted_writes);
363			total_written = data_used;
364
365			write_path = 1;
366
367		} else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
368					(pos + n <= wcp->offset + wcp->alloc_size)) {
369
370			/* ASCII art.... JRA.
371
372                        +---------------+
373                        | Cache buffer  |
374                        +---------------+
375
376            +-------------------+
377            | Data to write     |
378            +-------------------+
379
380	    		*/
381
382			/*
383			 * End of write overlaps the existing data.
384			 */
385
386			size_t data_used = pos + n - wcp->offset;
387
388			memcpy(wcp->data, data + n - data_used, data_used);
389
390			/*
391			 * Update the current buffer size with the new data.
392			 */
393
394			if(pos + n > wcp->offset + wcp->data_size) {
395				wcp->data_size = pos + n - wcp->offset;
396			}
397
398			/*
399			 * Update the file size if changed.
400			 */
401
402			if (wcp->offset + wcp->data_size > wcp->file_size) {
403				if (wcp_file_size_change(fsp) == -1) {
404					return -1;
405				}
406			}
407
408			/*
409			 * We don't need to move the start of data, but we
410			 * cut down the amount left by the amount used.
411			 */
412
413			n -= data_used;
414
415			/*
416			 * We cannot have used all the data here.
417			 */
418
419			cache_flush_needed = True;
420
421			DO_PROFILE_INC(writecache_abutted_writes);
422			total_written = data_used;
423
424			write_path = 2;
425
426		} else if ( (pos >= wcp->file_size) &&
427					(wcp->offset + wcp->data_size == wcp->file_size) &&
428					(pos > wcp->offset + wcp->data_size) &&
429					(pos < wcp->offset + wcp->alloc_size) ) {
430
431			/* ASCII art.... JRA.
432
433                       End of file ---->|
434
435                        +---------------+---------------+
436                        | Cached data   | Cache buffer  |
437                        +---------------+---------------+
438
439                                              +-------------------+
440                                              | Data to write     |
441                                              +-------------------+
442
443	    		*/
444
445			/*
446			 * Non-contiguous write part of which fits within
447			 * the cache buffer and is extending the file
448			 * and the cache contents reflect the current
449			 * data up to the current end of the file.
450			 */
451
452			size_t data_used;
453
454			if(pos + n <= wcp->offset + wcp->alloc_size) {
455				data_used = n;
456			} else {
457				data_used = wcp->offset + wcp->alloc_size - pos;
458			}
459
460			/*
461			 * Fill in the non-continuous area with zeros.
462			 */
463
464			memset(wcp->data + wcp->data_size, '\0',
465				pos - (wcp->offset + wcp->data_size) );
466
467			memcpy(wcp->data + (pos - wcp->offset), data, data_used);
468
469			/*
470			 * Update the current buffer size with the new data.
471			 */
472
473			if(pos + data_used > wcp->offset + wcp->data_size) {
474				wcp->data_size = pos + data_used - wcp->offset;
475			}
476
477			/*
478			 * Update the file size if changed.
479			 */
480
481			if (wcp->offset + wcp->data_size > wcp->file_size) {
482				if (wcp_file_size_change(fsp) == -1) {
483					return -1;
484				}
485			}
486
487			/*
488			 * If we used all the data then
489			 * return here.
490			 */
491
492			if(n == data_used) {
493				return n;
494			} else {
495				cache_flush_needed = True;
496			}
497
498			/*
499			 * Move the start of data forward by the amount used,
500			 * cut down the amount left by the same amount.
501			 */
502
503			data += data_used;
504			pos += data_used;
505			n -= data_used;
506
507			DO_PROFILE_INC(writecache_abutted_writes);
508			total_written = data_used;
509
510			write_path = 3;
511
512                } else if ( (pos >= wcp->file_size) &&
513			    (n == 1) &&
514			    (pos < wcp->offset + 2*wcp->alloc_size) &&
515			    (wcp->file_size == wcp->offset + wcp->data_size)) {
516
517                        /*
518                        +---------------+
519                        | Cached data   |
520                        +---------------+
521
522                                                         +--------+
523                                                         | 1 Byte |
524                                                         +--------+
525
526			MS-Office seems to do this a lot to determine if there's enough
527			space on the filesystem to write a new file.
528                        */
529
530			SMB_BIG_UINT new_start = wcp->offset + wcp->data_size;
531
532			flush_write_cache(fsp, WRITE_FLUSH);
533			wcp->offset = new_start;
534			wcp->data_size = pos - new_start + 1;
535			memset(wcp->data, '\0', wcp->data_size);
536			memcpy(wcp->data + wcp->data_size-1, data, 1);
537
538			/*
539			 * Update the file size if changed.
540			 */
541
542			if (wcp->offset + wcp->data_size > wcp->file_size) {
543				if (wcp_file_size_change(fsp) == -1) {
544					return -1;
545				}
546			}
547
548			return n;
549
550		} else {
551
552			/* ASCII art..... JRA.
553
554   Case 1).
555
556                        +---------------+---------------+
557                        | Cached data   | Cache buffer  |
558                        +---------------+---------------+
559
560                                                              +-------------------+
561                                                              | Data to write     |
562                                                              +-------------------+
563
564   Case 2).
565
566                           +---------------+---------------+
567                           | Cached data   | Cache buffer  |
568                           +---------------+---------------+
569
570   +-------------------+
571   | Data to write     |
572   +-------------------+
573
574    Case 3).
575
576                           +---------------+---------------+
577                           | Cached data   | Cache buffer  |
578                           +---------------+---------------+
579
580                  +-----------------------------------------------------+
581                  | Data to write                                       |
582                  +-----------------------------------------------------+
583
584		  */
585
586 			/*
587			 * Write is bigger than buffer, or there is no overlap on the
588			 * low or high ends.
589			 */
590
591			DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
592len = %u\n",fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
593
594			/*
595			 * If write would fit in the cache, and is larger than
596			 * the data already in the cache, flush the cache and
597			 * preferentially copy the data new data into it. Otherwise
598			 * just write the data directly.
599			 */
600
601			if ( n <= wcp->alloc_size && n > wcp->data_size) {
602				cache_flush_needed = True;
603			} else {
604				ssize_t ret = real_write_file(fsp, data, pos, n);
605
606				/*
607				 * If the write overlaps the entire cache, then
608				 * discard the current contents of the cache.
609				 * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
610				 */
611
612				if ((pos <= wcp->offset) &&
613						(pos + n >= wcp->offset + wcp->data_size) ) {
614					DEBUG(9,("write_file: discarding overwritten write \
615cache: fd = %d, off=%.0f, size=%u\n", fsp->fh->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
616					wcp->data_size = 0;
617				}
618
619				DO_PROFILE_INC(writecache_direct_writes);
620				if (ret == -1) {
621					return ret;
622				}
623
624				if (pos + ret > wcp->file_size) {
625					wcp->file_size = pos + ret;
626				}
627
628				return ret;
629			}
630
631			write_path = 4;
632
633		}
634
635		if (cache_flush_needed) {
636			DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
637n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
638				write_path, fsp->fh->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
639				(double)wcp->offset, (unsigned int)wcp->data_size ));
640
641			flush_write_cache(fsp, WRITE_FLUSH);
642		}
643	}
644
645	/*
646	 * If the write request is bigger than the cache
647	 * size, write it all out.
648	 */
649
650	if (n > wcp->alloc_size ) {
651		ssize_t ret = real_write_file(fsp, data, pos, n);
652		if (ret == -1) {
653			return -1;
654		}
655
656		if (pos + ret > wcp->file_size) {
657			wcp->file_size = pos + n;
658		}
659
660		DO_PROFILE_INC(writecache_direct_writes);
661		return total_written + n;
662	}
663
664	/*
665	 * If there's any data left, cache it.
666	 */
667
668	if (n) {
669#ifdef WITH_PROFILE
670		if (wcp->data_size) {
671			DO_PROFILE_INC(writecache_abutted_writes);
672		} else {
673			DO_PROFILE_INC(writecache_init_writes);
674		}
675#endif
676		memcpy(wcp->data+wcp->data_size, data, n);
677		if (wcp->data_size == 0) {
678			wcp->offset = pos;
679			DO_PROFILE_INC(writecache_num_write_caches);
680		}
681		wcp->data_size += n;
682
683		/*
684		 * Update the file size if changed.
685		 */
686
687		if (wcp->offset + wcp->data_size > wcp->file_size) {
688			if (wcp_file_size_change(fsp) == -1) {
689				return -1;
690			}
691		}
692		DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
693			(double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
694
695		total_written += n;
696		return total_written; /* .... that's a write :) */
697	}
698
699	return total_written;
700}
701
702/****************************************************************************
703 Delete the write cache structure.
704****************************************************************************/
705
706void delete_write_cache(files_struct *fsp)
707{
708	write_cache *wcp;
709
710	if(!fsp) {
711		return;
712	}
713
714	if(!(wcp = fsp->wcp)) {
715		return;
716	}
717
718	DO_PROFILE_DEC(writecache_allocated_write_caches);
719	allocated_write_caches--;
720
721	SMB_ASSERT(wcp->data_size == 0);
722
723	SAFE_FREE(wcp->data);
724	SAFE_FREE(fsp->wcp);
725
726	DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
727}
728
729/****************************************************************************
730 Setup the write cache structure.
731****************************************************************************/
732
733static BOOL setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
734{
735	ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
736	write_cache *wcp;
737
738	if (allocated_write_caches >= MAX_WRITE_CACHES) {
739		return False;
740	}
741
742	if(alloc_size == 0 || fsp->wcp) {
743		return False;
744	}
745
746	if((wcp = SMB_MALLOC_P(write_cache)) == NULL) {
747		DEBUG(0,("setup_write_cache: malloc fail.\n"));
748		return False;
749	}
750
751	wcp->file_size = file_size;
752	wcp->offset = 0;
753	wcp->alloc_size = alloc_size;
754	wcp->data_size = 0;
755	if((wcp->data = (char *)SMB_MALLOC(wcp->alloc_size)) == NULL) {
756		DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
757			(unsigned int)wcp->alloc_size ));
758		SAFE_FREE(wcp);
759		return False;
760	}
761
762	memset(wcp->data, '\0', wcp->alloc_size );
763
764	fsp->wcp = wcp;
765	DO_PROFILE_INC(writecache_allocated_write_caches);
766	allocated_write_caches++;
767
768	DEBUG(10,("setup_write_cache: File %s allocated write cache size %lu\n",
769		fsp->fsp_name, (unsigned long)wcp->alloc_size ));
770
771	return True;
772}
773
774/****************************************************************************
775 Cope with a size change.
776****************************************************************************/
777
778void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
779{
780	if(fsp->wcp) {
781		/* The cache *must* have been flushed before we do this. */
782		if (fsp->wcp->data_size != 0) {
783			pstring msg;
784			slprintf(msg, sizeof(msg)-1, "set_filelen_write_cache: size change \
785on file %s with write cache size = %lu\n", fsp->fsp_name, (unsigned long)fsp->wcp->data_size );
786			smb_panic(msg);
787		}
788		fsp->wcp->file_size = file_size;
789	}
790}
791
792/*******************************************************************
793 Flush a write cache struct to disk.
794********************************************************************/
795
796ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
797{
798	write_cache *wcp = fsp->wcp;
799	size_t data_size;
800	ssize_t ret;
801
802	if(!wcp || !wcp->data_size) {
803		return 0;
804	}
805
806	data_size = wcp->data_size;
807	wcp->data_size = 0;
808
809	DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
810
811	DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
812		fsp->fh->fd, (double)wcp->offset, (unsigned int)data_size));
813
814#ifdef WITH_PROFILE
815	if(data_size == wcp->alloc_size) {
816		DO_PROFILE_INC(writecache_num_perfect_writes);
817	}
818#endif
819
820	ret = real_write_file(fsp, wcp->data, wcp->offset, data_size);
821
822	/*
823	 * Ensure file size if kept up to date if write extends file.
824	 */
825
826	if ((ret != -1) && (wcp->offset + ret > wcp->file_size)) {
827		wcp->file_size = wcp->offset + ret;
828	}
829
830	return ret;
831}
832
833/*******************************************************************
834sync a file
835********************************************************************/
836
837NTSTATUS sync_file(connection_struct *conn, files_struct *fsp, BOOL write_through)
838{
839       	if (fsp->fh->fd == -1)
840		return NT_STATUS_INVALID_HANDLE;
841
842	if (lp_strict_sync(SNUM(conn)) &&
843	    (lp_syncalways(SNUM(conn)) || write_through)) {
844		int ret = flush_write_cache(fsp, SYNC_FLUSH);
845		if (ret == -1) {
846			return map_nt_error_from_unix(errno);
847		}
848		ret = SMB_VFS_FSYNC(fsp,fsp->fh->fd);
849		if (ret == -1) {
850			return map_nt_error_from_unix(errno);
851		}
852	}
853	return NT_STATUS_OK;
854}
855
856/************************************************************
857 Perform a stat whether a valid fd or not.
858************************************************************/
859
860int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
861{
862	if (fsp->fh->fd == -1) {
863		return SMB_VFS_STAT(fsp->conn, fsp->fsp_name, pst);
864	} else {
865		return SMB_VFS_FSTAT(fsp,fsp->fh->fd, pst);
866	}
867}
868