source/smbd/fileio.c

   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
  25 static BOOL setup_write_cache(files_struct *, SMB_OFF_T);
  26
  27 /****************************************************************************
  28  Seek a file. Try to avoid the seek if possible.
  29 ****************************************************************************/
  30
  31 SMB_OFF_T seek_file(files_struct *fsp,SMB_OFF_T pos)
  32 {
  33         SMB_OFF_T offset = 0;
  34         SMB_OFF_T seek_ret;
  35
  36         if (fsp->print_file && lp_postscript(fsp->conn->service))
  37                 offset = 3;
  38
  39         seek_ret = fsp->conn->vfs_ops.lseek(fsp,fsp->fd,pos+offset,SEEK_SET);
  40
  41         if(seek_ret == -1) {
  42                 DEBUG(0,("seek_file: (%s) sys_lseek failed. Error was %s\n",
  43                         fsp->fsp_name, strerror(errno) ));
  44                 fsp->pos = -1;
  45                 return -1;
  46         }
  47
  48         fsp->pos = seek_ret - offset;
  49
  50         DEBUG(10,("seek_file (%s): requested pos = %.0f, new pos = %.0f\n",
  51                 fsp->fsp_name, (double)(pos+offset), (double)fsp->pos ));
  52
  53         return(fsp->pos);
  54 }
  55
  56 /****************************************************************************
  57  Read from write cache if we can.
  58 ****************************************************************************/
  59
  60
  61 BOOL read_from_write_cache(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
  62 {
  63         write_cache *wcp = fsp->wcp;
  64
  65         if(!wcp)
  66                 return False;
  67
  68         if(n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size)
  69                 return False;
  70
  71         memcpy(data, wcp->data + (pos - wcp->offset), n);
  72
  73         DO_PROFILE_INC(writecache_read_hits);
  74
  75         return True;
  76 }
  77
  78 /****************************************************************************
  79  Read from a file.
  80 ****************************************************************************/
  81
  82 ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
  83 {
  84         ssize_t ret=0,readret;
  85
  86         /* you can't read from print files */
  87         if (fsp->print_file)
  88                 return -1;
  89
  90         /*
  91          * Serve from write cache if we can.
  92          */
  93
  94         if(read_from_write_cache(fsp, data, pos, n))
  95                 return n;
  96
  97         flush_write_cache(fsp, READ_FLUSH);
  98
  99         if (seek_file(fsp,pos) == -1) {
 100                 DEBUG(3,("read_file: Failed to seek to %.0f\n",(double)pos));
 101                 return(ret);
 102         }
 103
 104         if (n > 0) {
 105 #ifdef DMF_FIX
 106                 int numretries = 3;
 107 tryagain:
 108                 readret = fsp->conn->vfs_ops.read(fsp,fsp->fd,data,n);
 109                 if (readret == -1) {
 110                         if ((errno == EAGAIN) && numretries) {
 111                                 DEBUG(3,("read_file EAGAIN retry in 10 seconds\n"));
 112                                 (void)sleep(10);
 113                                 --numretries;
 114                                 goto tryagain;
 115                         }
 116                         return -1;
 117                 }
 118 #else /* NO DMF fix. */
 119                 readret = fsp->conn->vfs_ops.read(fsp,fsp->fd,data,n);
 120                 if (readret == -1)
 121                         return -1;
 122 #endif
 123                 if (readret > 0)
 124                         ret += readret;
 125         }
 126
 127         DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
 128                 fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
 129
 130         return(ret);
 131 }
 132
 133 /* how many write cache buffers have been allocated */
 134 static unsigned int allocated_write_caches;
 135
 136 /****************************************************************************
 137  *Really* write to a file.
 138 ****************************************************************************/
 139
 140 static ssize_t real_write_file(files_struct *fsp,char *data,SMB_OFF_T pos, size_t n)
 141 {
 142         ssize_t ret;
 143
 144         if ((pos != -1) && (seek_file(fsp,pos) == -1))
 145                 return -1;
 146
 147         ret = vfs_write_data(fsp,data,n);
 148
 149         DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
 150                 fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
 151
 152         return ret;
 153 }
 154
 155 /****************************************************************************
 156 write to a file
 157 ****************************************************************************/
 158
 159 ssize_t write_file(files_struct *fsp, char *data, SMB_OFF_T pos, size_t n)
 160 {
 161         write_cache *wcp = fsp->wcp;
 162         ssize_t total_written = 0;
 163         int write_path = -1;
 164
 165         if (fsp->print_file)
 166                 return print_job_write(fsp->print_jobid, data, n);
 167
 168         if (!fsp->can_write) {
 169                 errno = EPERM;
 170                 return(0);
 171         }
 172
 173         if (!fsp->modified) {
 174                 SMB_STRUCT_STAT st;
 175                 fsp->modified = True;
 176
 177                 if (fsp->conn->vfs_ops.fstat(fsp,fsp->fd,&st) == 0) {
 178                         int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
 179                         fsp->size = st.st_size;
 180                         if (MAP_ARCHIVE(fsp->conn) && !IS_DOS_ARCHIVE(dosmode))
 181                                 file_chmod(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st);
 182
 183                         /*
 184                          * If this is the first write and we have an exclusive oplock then setup
 185                          * the write cache.
 186                          */
 187
 188                         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
 189                                 setup_write_cache(fsp, st.st_size);
 190                                 wcp = fsp->wcp;
 191                         }
 192                 }
 193         }
 194
 195 #ifdef WITH_PROFILE
 196         DO_PROFILE_INC(writecache_total_writes);
 197         if (!fsp->oplock_type) {
 198                 DO_PROFILE_INC(writecache_non_oplock_writes);
 199         }
 200 #endif
 201
 202         /*
 203          * If this file is level II oplocked then we need
 204          * to grab the shared memory lock and inform all
 205          * other files with a level II lock that they need
 206          * to flush their read caches. We keep the lock over
 207          * the shared memory area whilst doing this.
 208          */
 209
 210         release_level_2_oplocks_on_change(fsp);
 211
 212 #ifdef WITH_PROFILE
 213         if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
 214                 DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
 215 nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
 216                         profile_p->writecache_init_writes,
 217                         profile_p->writecache_abutted_writes,
 218                         profile_p->writecache_total_writes,
 219                         profile_p->writecache_non_oplock_writes,
 220                         profile_p->writecache_allocated_write_caches,
 221                         profile_p->writecache_num_write_caches,
 222                         profile_p->writecache_direct_writes,
 223                         profile_p->writecache_num_perfect_writes,
 224                         profile_p->writecache_read_hits ));
 225
 226                 DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
 227                         profile_p->writecache_flushed_writes[SEEK_FLUSH],
 228                         profile_p->writecache_flushed_writes[READ_FLUSH],
 229                         profile_p->writecache_flushed_writes[WRITE_FLUSH],
 230                         profile_p->writecache_flushed_writes[READRAW_FLUSH],
 231                         profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
 232                         profile_p->writecache_flushed_writes[CLOSE_FLUSH],
 233                         profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
 234         }
 235 #endif
 236
 237         if(!wcp) {
 238                 DO_PROFILE_INC(writecache_direct_writes);
 239                 total_written = real_write_file(fsp, data, pos, n);
 240                 if ((total_written != -1) && (pos + total_written > fsp->size))
 241                         fsp->size = pos + total_written;
 242                 return total_written;
 243         }
 244
 245         DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f wcp->data_size=%u\n",
 246                 fsp->fsp_name, fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size));
 247
 248         /*
 249          * If we have active cache and it isn't contiguous then we flush.
 250          * NOTE: There is a small problem with running out of disk ....
 251          */
 252
 253         if (wcp->data_size) {
 254
 255                 BOOL cache_flush_needed = False;
 256
 257                 if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
 258
 259                         /* ASCII art.... JRA.
 260
 261       +--------------+-----
 262       | Cached data  | Rest of allocated cache buffer....
 263       +--------------+-----
 264
 265             +-------------------+
 266             | Data to write     |
 267             +-------------------+
 268
 269                         */
 270
 271                         /*
 272                          * Start of write overlaps or abutts the existing data.
 273                          */
 274
 275                         size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
 276
 277                         memcpy(wcp->data + (pos - wcp->offset), data, data_used);
 278
 279                         /*
 280                          * Update the current buffer size with the new data.
 281                          */
 282
 283                         if(pos + data_used > wcp->offset + wcp->data_size)
 284                                 wcp->data_size = pos + data_used - wcp->offset;
 285
 286                         /*
 287                          * Update the file size if changed.
 288                          */
 289
 290                         if (wcp->offset + wcp->data_size > wcp->file_size)
 291                                 fsp->size = wcp->file_size = wcp->offset + wcp->data_size;
 292
 293                         /*
 294                          * If we used all the data then
 295                          * return here.
 296                          */
 297
 298                         if(n == data_used)
 299                                 return n;
 300                         else
 301                                 cache_flush_needed = True;
 302
 303                         /*
 304                          * Move the start of data forward by the amount used,
 305                          * cut down the amount left by the same amount.
 306                          */
 307
 308                         data += data_used;
 309                         pos += data_used;
 310                         n -= data_used;
 311
 312                         DO_PROFILE_INC(writecache_abutted_writes);
 313                         total_written = data_used;
 314
 315                         write_path = 1;
 316
 317                 } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
 318                                         (pos + n <= wcp->offset + wcp->alloc_size)) {
 319
 320                         /* ASCII art.... JRA.
 321
 322                         +---------------+
 323                         | Cache buffer  |
 324                         +---------------+
 325
 326             +-------------------+
 327             | Data to write     |
 328             +-------------------+
 329
 330                         */
 331
 332                         /*
 333                          * End of write overlaps the existing data.
 334                          */
 335
 336                         size_t data_used = pos + n - wcp->offset;
 337
 338                         memcpy(wcp->data, data + n - data_used, data_used);
 339
 340                         /*
 341                          * Update the current buffer size with the new data.
 342                          */
 343
 344                         if(pos + n > wcp->offset + wcp->data_size)
 345                                 wcp->data_size = pos + n - wcp->offset;
 346
 347                         /*
 348                          * Update the file size if changed.
 349                          */
 350
 351                         if (wcp->offset + wcp->data_size > wcp->file_size)
 352                                 fsp->size = wcp->file_size = wcp->offset + wcp->data_size;
 353
 354                         /*
 355                          * We don't need to move the start of data, but we
 356                          * cut down the amount left by the amount used.
 357                          */
 358
 359                         n -= data_used;
 360
 361                         /*
 362                          * We cannot have used all the data here.
 363                          */
 364
 365                         cache_flush_needed = True;
 366
 367                         DO_PROFILE_INC(writecache_abutted_writes);
 368                         total_written = data_used;
 369
 370                         write_path = 2;
 371
 372                 } else if ( (pos >= wcp->file_size) &&
 373                                         (wcp->offset + wcp->data_size == wcp->file_size) &&
 374                                         (pos > wcp->offset + wcp->data_size) &&
 375                                         (pos < wcp->offset + wcp->alloc_size) ) {
 376
 377                         /* ASCII art.... JRA.
 378
 379                        End of file ---->|
 380
 381                         +---------------+---------------+
 382                         | Cached data   | Cache buffer  |
 383                         +---------------+---------------+
 384
 385                                               +-------------------+
 386                                               | Data to write     |
 387                                               +-------------------+
 388
 389                         */
 390
 391                         /*
 392                          * Non-contiguous write part of which fits within
 393                          * the cache buffer and is extending the file
 394                          * and the cache contents reflect the current
 395                          * data up to the current end of the file.
 396                          */
 397
 398                         size_t data_used;
 399
 400                         if(pos + n <= wcp->offset + wcp->alloc_size)
 401                                 data_used = n;
 402                         else
 403                                 data_used = wcp->offset + wcp->alloc_size - pos;
 404
 405                         /*
 406                          * Fill in the non-continuous area with zeros.
 407                          */
 408
 409                         memset(wcp->data + wcp->data_size, '\0',
 410                                 pos - (wcp->offset + wcp->data_size) );
 411
 412                         memcpy(wcp->data + (pos - wcp->offset), data, data_used);
 413
 414                         /*
 415                          * Update the current buffer size with the new data.
 416                          */
 417
 418                         if(pos + data_used > wcp->offset + wcp->data_size)
 419                                 wcp->data_size = pos + data_used - wcp->offset;
 420
 421                         /*
 422                          * Update the file size if changed.
 423                          */
 424
 425                         if (wcp->offset + wcp->data_size > wcp->file_size)
 426                                 fsp->size = wcp->file_size = wcp->offset + wcp->data_size;
 427
 428                         /*
 429                          * If we used all the data then
 430                          * return here.
 431                          */
 432
 433                         if(n == data_used)
 434                                 return n;
 435                         else
 436                                 cache_flush_needed = True;
 437
 438                         /*
 439                          * Move the start of data forward by the amount used,
 440                          * cut down the amount left by the same amount.
 441                          */
 442
 443                         data += data_used;
 444                         pos += data_used;
 445                         n -= data_used;
 446
 447                         DO_PROFILE_INC(writecache_abutted_writes);
 448                         total_written = data_used;
 449
 450                         write_path = 3;
 451
 452                 } else {
 453
 454                         /* ASCII art..... JRA.
 455
 456    Case 1).
 457
 458                         +---------------+---------------+
 459                         | Cached data   | Cache buffer  |
 460                         +---------------+---------------+
 461
 462                                                               +-------------------+
 463                                                               | Data to write     |
 464                                                               +-------------------+
 465
 466    Case 2).
 467
 468                            +---------------+---------------+
 469                            | Cached data   | Cache buffer  |
 470                            +---------------+---------------+
 471
 472    +-------------------+
 473    | Data to write     |
 474    +-------------------+
 475
 476     Case 3).
 477
 478                            +---------------+---------------+
 479                            | Cached data   | Cache buffer  |
 480                            +---------------+---------------+
 481
 482                   +-----------------------------------------------------+
 483                   | Data to write                                       |
 484                   +-----------------------------------------------------+
 485
 486                   */
 487
 488                         /*
 489                          * Write is bigger than buffer, or there is no overlap on the
 490                          * low or high ends.
 491                          */
 492
 493                         DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
 494 len = %u\n",fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
 495
 496                         /*
 497                          * Update the file size if needed.
 498                          */
 499
 500                         if(pos + n > wcp->file_size)
 501                                 fsp->size = wcp->file_size = pos + n;
 502
 503                         /*
 504                          * If write would fit in the cache, and is larger than
 505                          * the data already in the cache, flush the cache and
 506                          * preferentially copy the data new data into it. Otherwise
 507                          * just write the data directly.
 508                          */
 509
 510                         if ( n <= wcp->alloc_size && n > wcp->data_size) {
 511                                 cache_flush_needed = True;
 512                         } else {
 513                                 ssize_t ret = real_write_file(fsp, data, pos, n);
 514
 515                                 /*
 516                                  * If the write overlaps the entire cache, then
 517                                  * discard the current contents of the cache.
 518                                  * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
 519                                  */
 520
 521                                 if ((pos <= wcp->offset) &&
 522                                                 (pos + n >= wcp->offset + wcp->data_size) ) {
 523                                         DEBUG(9,("write_file: discarding overwritten write \
 524 cache: fd = %d, off=%.0f, size=%u\n", fsp->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
 525                                         wcp->data_size = 0;
 526                                 }
 527
 528                                 DO_PROFILE_INC(writecache_direct_writes);
 529                                 if (ret == -1)
 530                                         return ret;
 531
 532                                 if (pos + ret > wcp->file_size)
 533                                         fsp->size = wcp->file_size = pos + ret;
 534
 535                                 return ret;
 536                         }
 537
 538                         write_path = 4;
 539
 540                 }
 541
 542                 if(wcp->data_size > wcp->file_size)
 543                         fsp->size = wcp->file_size = wcp->data_size;
 544
 545                 if (cache_flush_needed) {
 546                         DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
 547 n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
 548                                 write_path, fsp->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
 549                                 (double)wcp->offset, (unsigned int)wcp->data_size ));
 550
 551                         flush_write_cache(fsp, WRITE_FLUSH);
 552                 }
 553         }
 554
 555         /*
 556          * If the write request is bigger than the cache
 557          * size, write it all out.
 558          */
 559
 560         if (n > wcp->alloc_size ) {
 561                 ssize_t ret = real_write_file(fsp, data, pos, n);
 562                 if (ret == -1)
 563                         return -1;
 564
 565                 if (pos + ret > wcp->file_size)
 566                         fsp->size = wcp->file_size = pos + n;
 567
 568                 DO_PROFILE_INC(writecache_direct_writes);
 569                 return total_written + n;
 570         }
 571
 572         /*
 573          * If there's any data left, cache it.
 574          */
 575
 576         if (n) {
 577 #ifdef WITH_PROFILE
 578                 if (wcp->data_size) {
 579                         DO_PROFILE_INC(writecache_abutted_writes);
 580                 } else {
 581                         DO_PROFILE_INC(writecache_init_writes);
 582                 }
 583 #endif
 584                 memcpy(wcp->data+wcp->data_size, data, n);
 585                 if (wcp->data_size == 0) {
 586                         wcp->offset = pos;
 587                         DO_PROFILE_INC(writecache_num_write_caches);
 588                 }
 589                 wcp->data_size += n;
 590
 591                 /*
 592                  * Update the file size if changed.
 593                  */
 594
 595                 if (wcp->offset + wcp->data_size > wcp->file_size)
 596                         fsp->size = wcp->file_size = wcp->offset + wcp->data_size;
 597                 DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
 598                         (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
 599
 600                 total_written += n;
 601                 return total_written; /* .... that's a write :) */
 602         }
 603
 604         return total_written;
 605 }
 606
 607 /****************************************************************************
 608  Delete the write cache structure.
 609 ****************************************************************************/
 610
 611 void delete_write_cache(files_struct *fsp)
 612 {
 613         write_cache *wcp;
 614
 615         if(!fsp)
 616                 return;
 617
 618         if(!(wcp = fsp->wcp))
 619                 return;
 620
 621         DO_PROFILE_DEC(writecache_allocated_write_caches);
 622         allocated_write_caches--;
 623
 624         SMB_ASSERT(wcp->data_size == 0);
 625
 626         SAFE_FREE(wcp->data);
 627         SAFE_FREE(fsp->wcp);
 628
 629         DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
 630 }
 631
 632 /****************************************************************************
 633  Setup the write cache structure.
 634 ****************************************************************************/
 635
 636 static BOOL setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
 637 {
 638         ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
 639         write_cache *wcp;
 640
 641         if (allocated_write_caches >= MAX_WRITE_CACHES)
 642                 return False;
 643
 644         if(alloc_size == 0 || fsp->wcp)
 645                 return False;
 646
 647         if((wcp = (write_cache *)malloc(sizeof(write_cache))) == NULL) {
 648                 DEBUG(0,("setup_write_cache: malloc fail.\n"));
 649                 return False;
 650         }
 651
 652         wcp->file_size = file_size;
 653         wcp->offset = 0;
 654         wcp->alloc_size = alloc_size;
 655         wcp->data_size = 0;
 656         if((wcp->data = malloc(wcp->alloc_size)) == NULL) {
 657                 DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
 658                         (unsigned int)wcp->alloc_size ));
 659                 SAFE_FREE(wcp);
 660                 return False;
 661         }
 662
 663         memset(wcp->data, '\0', wcp->alloc_size );
 664
 665         fsp->wcp = wcp;
 666         DO_PROFILE_INC(writecache_allocated_write_caches);
 667         allocated_write_caches++;
 668
 669         DEBUG(10,("setup_write_cache: File %s allocated write cache size %u\n",
 670                 fsp->fsp_name, wcp->alloc_size ));
 671
 672         return True;
 673 }
 674
 675 /****************************************************************************
 676  Cope with a size change.
 677 ****************************************************************************/
 678
 679 void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
 680 {
 681         fsp->size = file_size;
 682         if(fsp->wcp) {
 683                 /* The cache *must* have been flushed before we do this. */
 684                 if (fsp->wcp->data_size != 0) {
 685                         pstring msg;
 686                         slprintf(msg, sizeof(msg)-1, "set_filelen_write_cache: size change \
 687 on file %s with write cache size = %u\n", fsp->fsp_name, fsp->wcp->data_size );
 688                         smb_panic(msg);
 689                 }
 690                 fsp->wcp->file_size = file_size;
 691         }
 692 }
 693
 694 /*******************************************************************
 695  Flush a write cache struct to disk.
 696 ********************************************************************/
 697
 698 ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
 699 {
 700         write_cache *wcp = fsp->wcp;
 701         size_t data_size;
 702         ssize_t ret;
 703
 704         if(!wcp || !wcp->data_size)
 705                 return 0;
 706
 707         data_size = wcp->data_size;
 708         wcp->data_size = 0;
 709
 710         DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
 711
 712         DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
 713                 fsp->fd, (double)wcp->offset, (unsigned int)data_size));
 714
 715 #ifdef WITH_PROFILE
 716         if(data_size == wcp->alloc_size)
 717                 DO_PROFILE_INC(writecache_num_perfect_writes);
 718 #endif
 719
 720         ret = real_write_file(fsp, wcp->data, wcp->offset, data_size);
 721
 722         /*
 723          * Ensure file size if kept up to date if write extends file.
 724          */
 725
 726         if ((ret != -1) && (wcp->offset + ret > wcp->file_size))
 727                 wcp->file_size = wcp->offset + ret;
 728
 729         return ret;
 730 }
 731
 732 /*******************************************************************
 733 sync a file
 734 ********************************************************************/
 735
 736 void sync_file(connection_struct *conn, files_struct *fsp)
 737 {
 738         if(lp_strict_sync(SNUM(conn)) && fsp->fd != -1) {
 739                 flush_write_cache(fsp, SYNC_FLUSH);
 740                 conn->vfs_ops.fsync(fsp,fsp->fd);
 741         }
 742 }
 743
 744
 745 /************************************************************
 746  Perform a stat whether a valid fd or not.
 747 ************************************************************/
 748
 749 int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
 750 {
 751         if (fsp->fd == -1)
 752                 return vfs_stat(fsp->conn, fsp->fsp_name, pst);
 753         else
 754                 return vfs_fstat(fsp,fsp->fd, pst);
 755 }