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 = (SMB_BIG_UINT)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 > (SMB_OFF_T)fsp->size))
 241                         fsp->size = (SMB_BIG_UINT)(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                                 wcp->file_size = wcp->offset + wcp->data_size;
 292                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 293                         }
 294
 295                         /*
 296                          * If we used all the data then
 297                          * return here.
 298                          */
 299
 300                         if(n == data_used)
 301                                 return n;
 302                         else
 303                                 cache_flush_needed = True;
 304
 305                         /*
 306                          * Move the start of data forward by the amount used,
 307                          * cut down the amount left by the same amount.
 308                          */
 309
 310                         data += data_used;
 311                         pos += data_used;
 312                         n -= data_used;
 313
 314                         DO_PROFILE_INC(writecache_abutted_writes);
 315                         total_written = data_used;
 316
 317                         write_path = 1;
 318
 319                 } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
 320                                         (pos + n <= wcp->offset + wcp->alloc_size)) {
 321
 322                         /* ASCII art.... JRA.
 323
 324                         +---------------+
 325                         | Cache buffer  |
 326                         +---------------+
 327
 328             +-------------------+
 329             | Data to write     |
 330             +-------------------+
 331
 332                         */
 333
 334                         /*
 335                          * End of write overlaps the existing data.
 336                          */
 337
 338                         size_t data_used = pos + n - wcp->offset;
 339
 340                         memcpy(wcp->data, data + n - data_used, data_used);
 341
 342                         /*
 343                          * Update the current buffer size with the new data.
 344                          */
 345
 346                         if(pos + n > wcp->offset + wcp->data_size)
 347                                 wcp->data_size = pos + n - wcp->offset;
 348
 349                         /*
 350                          * Update the file size if changed.
 351                          */
 352
 353                         if (wcp->offset + wcp->data_size > wcp->file_size) {
 354                                 wcp->file_size = wcp->offset + wcp->data_size;
 355                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 356                         }
 357
 358                         /*
 359                          * We don't need to move the start of data, but we
 360                          * cut down the amount left by the amount used.
 361                          */
 362
 363                         n -= data_used;
 364
 365                         /*
 366                          * We cannot have used all the data here.
 367                          */
 368
 369                         cache_flush_needed = True;
 370
 371                         DO_PROFILE_INC(writecache_abutted_writes);
 372                         total_written = data_used;
 373
 374                         write_path = 2;
 375
 376                 } else if ( (pos >= wcp->file_size) &&
 377                                         (wcp->offset + wcp->data_size == wcp->file_size) &&
 378                                         (pos > wcp->offset + wcp->data_size) &&
 379                                         (pos < wcp->offset + wcp->alloc_size) ) {
 380
 381                         /* ASCII art.... JRA.
 382
 383                        End of file ---->|
 384
 385                         +---------------+---------------+
 386                         | Cached data   | Cache buffer  |
 387                         +---------------+---------------+
 388
 389                                               +-------------------+
 390                                               | Data to write     |
 391                                               +-------------------+
 392
 393                         */
 394
 395                         /*
 396                          * Non-contiguous write part of which fits within
 397                          * the cache buffer and is extending the file
 398                          * and the cache contents reflect the current
 399                          * data up to the current end of the file.
 400                          */
 401
 402                         size_t data_used;
 403
 404                         if(pos + n <= wcp->offset + wcp->alloc_size)
 405                                 data_used = n;
 406                         else
 407                                 data_used = wcp->offset + wcp->alloc_size - pos;
 408
 409                         /*
 410                          * Fill in the non-continuous area with zeros.
 411                          */
 412
 413                         memset(wcp->data + wcp->data_size, '\0',
 414                                 pos - (wcp->offset + wcp->data_size) );
 415
 416                         memcpy(wcp->data + (pos - wcp->offset), data, data_used);
 417
 418                         /*
 419                          * Update the current buffer size with the new data.
 420                          */
 421
 422                         if(pos + data_used > wcp->offset + wcp->data_size)
 423                                 wcp->data_size = pos + data_used - wcp->offset;
 424
 425                         /*
 426                          * Update the file size if changed.
 427                          */
 428
 429                         if (wcp->offset + wcp->data_size > wcp->file_size) {
 430                                 wcp->file_size = wcp->offset + wcp->data_size;
 431                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 432                         }
 433
 434                         /*
 435                          * If we used all the data then
 436                          * return here.
 437                          */
 438
 439                         if(n == data_used)
 440                                 return n;
 441                         else
 442                                 cache_flush_needed = True;
 443
 444                         /*
 445                          * Move the start of data forward by the amount used,
 446                          * cut down the amount left by the same amount.
 447                          */
 448
 449                         data += data_used;
 450                         pos += data_used;
 451                         n -= data_used;
 452
 453                         DO_PROFILE_INC(writecache_abutted_writes);
 454                         total_written = data_used;
 455
 456                         write_path = 3;
 457
 458                 } else {
 459
 460                         /* ASCII art..... JRA.
 461
 462    Case 1).
 463
 464                         +---------------+---------------+
 465                         | Cached data   | Cache buffer  |
 466                         +---------------+---------------+
 467
 468                                                               +-------------------+
 469                                                               | Data to write     |
 470                                                               +-------------------+
 471
 472    Case 2).
 473
 474                            +---------------+---------------+
 475                            | Cached data   | Cache buffer  |
 476                            +---------------+---------------+
 477
 478    +-------------------+
 479    | Data to write     |
 480    +-------------------+
 481
 482     Case 3).
 483
 484                            +---------------+---------------+
 485                            | Cached data   | Cache buffer  |
 486                            +---------------+---------------+
 487
 488                   +-----------------------------------------------------+
 489                   | Data to write                                       |
 490                   +-----------------------------------------------------+
 491
 492                   */
 493
 494                         /*
 495                          * Write is bigger than buffer, or there is no overlap on the
 496                          * low or high ends.
 497                          */
 498
 499                         DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
 500 len = %u\n",fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
 501
 502                         /*
 503                          * Update the file size if needed.
 504                          */
 505
 506                         if(pos + n > wcp->file_size) {
 507                                 wcp->file_size = pos + n;
 508                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 509                         }
 510
 511                         /*
 512                          * If write would fit in the cache, and is larger than
 513                          * the data already in the cache, flush the cache and
 514                          * preferentially copy the data new data into it. Otherwise
 515                          * just write the data directly.
 516                          */
 517
 518                         if ( n <= wcp->alloc_size && n > wcp->data_size) {
 519                                 cache_flush_needed = True;
 520                         } else {
 521                                 ssize_t ret = real_write_file(fsp, data, pos, n);
 522
 523                                 /*
 524                                  * If the write overlaps the entire cache, then
 525                                  * discard the current contents of the cache.
 526                                  * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
 527                                  */
 528
 529                                 if ((pos <= wcp->offset) &&
 530                                                 (pos + n >= wcp->offset + wcp->data_size) ) {
 531                                         DEBUG(9,("write_file: discarding overwritten write \
 532 cache: fd = %d, off=%.0f, size=%u\n", fsp->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
 533                                         wcp->data_size = 0;
 534                                 }
 535
 536                                 DO_PROFILE_INC(writecache_direct_writes);
 537                                 if (ret == -1)
 538                                         return ret;
 539
 540                                 if (pos + ret > wcp->file_size) {
 541                                         wcp->file_size = pos + ret;
 542                                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 543                                 }
 544
 545                                 return ret;
 546                         }
 547
 548                         write_path = 4;
 549
 550                 }
 551
 552                 if(wcp->data_size > wcp->file_size) {
 553                         wcp->file_size = wcp->data_size;
 554                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 555                 }
 556
 557                 if (cache_flush_needed) {
 558                         DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
 559 n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
 560                                 write_path, fsp->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
 561                                 (double)wcp->offset, (unsigned int)wcp->data_size ));
 562
 563                         flush_write_cache(fsp, WRITE_FLUSH);
 564                 }
 565         }
 566
 567         /*
 568          * If the write request is bigger than the cache
 569          * size, write it all out.
 570          */
 571
 572         if (n > wcp->alloc_size ) {
 573                 ssize_t ret = real_write_file(fsp, data, pos, n);
 574                 if (ret == -1)
 575                         return -1;
 576
 577                 if (pos + ret > wcp->file_size) {
 578                         wcp->file_size = pos + n;
 579                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 580                 }
 581
 582                 DO_PROFILE_INC(writecache_direct_writes);
 583                 return total_written + n;
 584         }
 585
 586         /*
 587          * If there's any data left, cache it.
 588          */
 589
 590         if (n) {
 591 #ifdef WITH_PROFILE
 592                 if (wcp->data_size) {
 593                         DO_PROFILE_INC(writecache_abutted_writes);
 594                 } else {
 595                         DO_PROFILE_INC(writecache_init_writes);
 596                 }
 597 #endif
 598                 memcpy(wcp->data+wcp->data_size, data, n);
 599                 if (wcp->data_size == 0) {
 600                         wcp->offset = pos;
 601                         DO_PROFILE_INC(writecache_num_write_caches);
 602                 }
 603                 wcp->data_size += n;
 604
 605                 /*
 606                  * Update the file size if changed.
 607                  */
 608
 609                 if (wcp->offset + wcp->data_size > wcp->file_size) {
 610                         wcp->file_size = wcp->offset + wcp->data_size;
 611                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 612                 }
 613                 DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
 614                         (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
 615
 616                 total_written += n;
 617                 return total_written; /* .... that's a write :) */
 618         }
 619
 620         return total_written;
 621 }
 622
 623 /****************************************************************************
 624  Delete the write cache structure.
 625 ****************************************************************************/
 626
 627 void delete_write_cache(files_struct *fsp)
 628 {
 629         write_cache *wcp;
 630
 631         if(!fsp)
 632                 return;
 633
 634         if(!(wcp = fsp->wcp))
 635                 return;
 636
 637         DO_PROFILE_DEC(writecache_allocated_write_caches);
 638         allocated_write_caches--;
 639
 640         SMB_ASSERT(wcp->data_size == 0);
 641
 642         SAFE_FREE(wcp->data);
 643         SAFE_FREE(fsp->wcp);
 644
 645         DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
 646 }
 647
 648 /****************************************************************************
 649  Setup the write cache structure.
 650 ****************************************************************************/
 651
 652 static BOOL setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
 653 {
 654         ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
 655         write_cache *wcp;
 656
 657         if (allocated_write_caches >= MAX_WRITE_CACHES)
 658                 return False;
 659
 660         if(alloc_size == 0 || fsp->wcp)
 661                 return False;
 662
 663         if((wcp = (write_cache *)malloc(sizeof(write_cache))) == NULL) {
 664                 DEBUG(0,("setup_write_cache: malloc fail.\n"));
 665                 return False;
 666         }
 667
 668         wcp->file_size = file_size;
 669         wcp->offset = 0;
 670         wcp->alloc_size = alloc_size;
 671         wcp->data_size = 0;
 672         if((wcp->data = malloc(wcp->alloc_size)) == NULL) {
 673                 DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
 674                         (unsigned int)wcp->alloc_size ));
 675                 SAFE_FREE(wcp);
 676                 return False;
 677         }
 678
 679         memset(wcp->data, '\0', wcp->alloc_size );
 680
 681         fsp->wcp = wcp;
 682         DO_PROFILE_INC(writecache_allocated_write_caches);
 683         allocated_write_caches++;
 684
 685         DEBUG(10,("setup_write_cache: File %s allocated write cache size %u\n",
 686                 fsp->fsp_name, wcp->alloc_size ));
 687
 688         return True;
 689 }
 690
 691 /****************************************************************************
 692  Cope with a size change.
 693 ****************************************************************************/
 694
 695 void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
 696 {
 697         fsp->size = (SMB_BIG_UINT)file_size;
 698         if(fsp->wcp) {
 699                 /* The cache *must* have been flushed before we do this. */
 700                 if (fsp->wcp->data_size != 0) {
 701                         pstring msg;
 702                         slprintf(msg, sizeof(msg)-1, "set_filelen_write_cache: size change \
 703 on file %s with write cache size = %u\n", fsp->fsp_name, fsp->wcp->data_size );
 704                         smb_panic(msg);
 705                 }
 706                 fsp->wcp->file_size = file_size;
 707         }
 708 }
 709
 710 /*******************************************************************
 711  Flush a write cache struct to disk.
 712 ********************************************************************/
 713
 714 ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
 715 {
 716         write_cache *wcp = fsp->wcp;
 717         size_t data_size;
 718         ssize_t ret;
 719
 720         if(!wcp || !wcp->data_size)
 721                 return 0;
 722
 723         data_size = wcp->data_size;
 724         wcp->data_size = 0;
 725
 726         DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
 727
 728         DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
 729                 fsp->fd, (double)wcp->offset, (unsigned int)data_size));
 730
 731 #ifdef WITH_PROFILE
 732         if(data_size == wcp->alloc_size)
 733                 DO_PROFILE_INC(writecache_num_perfect_writes);
 734 #endif
 735
 736         ret = real_write_file(fsp, wcp->data, wcp->offset, data_size);
 737
 738         /*
 739          * Ensure file size if kept up to date if write extends file.
 740          */
 741
 742         if ((ret != -1) && (wcp->offset + ret > wcp->file_size))
 743                 wcp->file_size = wcp->offset + ret;
 744
 745         return ret;
 746 }
 747
 748 /*******************************************************************
 749 sync a file
 750 ********************************************************************/
 751
 752 void sync_file(connection_struct *conn, files_struct *fsp)
 753 {
 754         if(lp_strict_sync(SNUM(conn)) && fsp->fd != -1) {
 755                 flush_write_cache(fsp, SYNC_FLUSH);
 756                 conn->vfs_ops.fsync(fsp,fsp->fd);
 757         }
 758 }
 759
 760
 761 /************************************************************
 762  Perform a stat whether a valid fd or not.
 763 ************************************************************/
 764
 765 int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
 766 {
 767         if (fsp->fd == -1)
 768                 return vfs_stat(fsp->conn, fsp->fsp_name, pst);
 769         else
 770                 return vfs_fstat(fsp,fsp->fd, pst);
 771 }