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 static SMB_OFF_T seek_file(files_struct *fsp,SMB_OFF_T pos)
  32 {
  33         SMB_OFF_T seek_ret;
  34
  35         seek_ret = SMB_VFS_LSEEK(fsp,fsp->fd,pos,SEEK_SET);
  36
  37         if(seek_ret == -1) {
  38                 DEBUG(0,("seek_file: (%s) sys_lseek failed. Error was %s\n",
  39                         fsp->fsp_name, strerror(errno) ));
  40                 fsp->pos = -1;
  41                 return -1;
  42         }
  43
  44         fsp->pos = seek_ret;
  45
  46         DEBUG(10,("seek_file (%s): requested pos = %.0f, new pos = %.0f\n",
  47                 fsp->fsp_name, (double)pos, (double)fsp->pos ));
  48
  49         return(fsp->pos);
  50 }
  51
  52 /****************************************************************************
  53  Read from write cache if we can.
  54 ****************************************************************************/
  55
  56
  57 static BOOL read_from_write_cache(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
  58 {
  59         write_cache *wcp = fsp->wcp;
  60
  61         if(!wcp)
  62                 return False;
  63
  64         if(n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size)
  65                 return False;
  66
  67         memcpy(data, wcp->data + (pos - wcp->offset), n);
  68
  69         DO_PROFILE_INC(writecache_read_hits);
  70
  71         return True;
  72 }
  73
  74 /****************************************************************************
  75  Read from a file.
  76 ****************************************************************************/
  77
  78 ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
  79 {
  80         ssize_t ret=0,readret;
  81
  82         /* you can't read from print files */
  83         if (fsp->print_file)
  84                 return -1;
  85
  86         /*
  87          * Serve from write cache if we can.
  88          */
  89
  90         if(read_from_write_cache(fsp, data, pos, n)) {
  91                 fsp->pos = pos + n;
  92                 fsp->position_information = fsp->pos;
  93                 return n;
  94         }
  95
  96         flush_write_cache(fsp, READ_FLUSH);
  97
  98         if (seek_file(fsp,pos) == -1) {
  99                 DEBUG(3,("read_file: Failed to seek to %.0f\n",(double)pos));
 100                 return(ret);
 101         }
 102
 103         if (n > 0) {
 104 #ifdef DMF_FIX
 105                 int numretries = 3;
 106 tryagain:
 107                 readret = SMB_VFS_READ(fsp,fsp->fd,data,n);
 108                 if (readret == -1) {
 109                         if ((errno == EAGAIN) && numretries) {
 110                                 DEBUG(3,("read_file EAGAIN retry in 10 seconds\n"));
 111                                 (void)sleep(10);
 112                                 --numretries;
 113                                 goto tryagain;
 114                         }
 115                         return -1;
 116                 }
 117 #else /* NO DMF fix. */
 118                 readret = SMB_VFS_READ(fsp,fsp->fd,data,n);
 119                 if (readret == -1)
 120                         return -1;
 121 #endif
 122                 if (readret > 0)
 123                         ret += readret;
 124         }
 125
 126         DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
 127                 fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
 128
 129         fsp->pos += ret;
 130         fsp->position_information = fsp->pos;
 131
 132         return(ret);
 133 }
 134
 135 /* how many write cache buffers have been allocated */
 136 static unsigned int allocated_write_caches;
 137
 138 /****************************************************************************
 139  *Really* write to a file.
 140 ****************************************************************************/
 141
 142 static ssize_t real_write_file(files_struct *fsp,char *data,SMB_OFF_T pos, size_t n)
 143 {
 144         ssize_t ret;
 145
 146         if ((pos != -1) && (seek_file(fsp,pos) == -1))
 147                 return -1;
 148
 149         ret = vfs_write_data(fsp,data,n);
 150
 151         DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
 152                 fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
 153
 154         if (ret != -1) {
 155                 fsp->pos += ret;
 156
 157 /* Yes - this is correct - writes don't update this. JRA. */
 158 /* Found by Samba4 tests. */
 159 #if 0
 160                 fsp->position_information = fsp->pos;
 161 #endif
 162         }
 163
 164         return ret;
 165 }
 166
 167 /****************************************************************************
 168 write to a file
 169 ****************************************************************************/
 170
 171 ssize_t write_file(files_struct *fsp, char *data, SMB_OFF_T pos, size_t n)
 172 {
 173         write_cache *wcp = fsp->wcp;
 174         ssize_t total_written = 0;
 175         int write_path = -1;
 176
 177         if (fsp->print_file) {
 178                 int snum;
 179                 uint32 jobid;
 180
 181                 if (!rap_to_pjobid(fsp->rap_print_jobid, &snum, &jobid)) {
 182                         DEBUG(3,("write_file: Unable to map RAP jobid %u to jobid.\n",
 183                                                 (unsigned int)fsp->rap_print_jobid ));
 184                         errno = EBADF;
 185                         return -1;
 186                 }
 187
 188                 return print_job_write(SNUM(fsp->conn), jobid, data, n);
 189         }
 190
 191         if (!fsp->can_write) {
 192                 errno = EPERM;
 193                 return(0);
 194         }
 195
 196         if (!fsp->modified) {
 197                 SMB_STRUCT_STAT st;
 198                 fsp->modified = True;
 199
 200                 if (SMB_VFS_FSTAT(fsp,fsp->fd,&st) == 0) {
 201                         int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
 202                         fsp->size = (SMB_BIG_UINT)st.st_size;
 203                         if (MAP_ARCHIVE(fsp->conn) && !IS_DOS_ARCHIVE(dosmode))
 204                                 file_chmod(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st);
 205
 206                         /*
 207                          * If this is the first write and we have an exclusive oplock then setup
 208                          * the write cache.
 209                          */
 210
 211                         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
 212                                 setup_write_cache(fsp, st.st_size);
 213                                 wcp = fsp->wcp;
 214                         }
 215                 }
 216         }
 217
 218 #ifdef WITH_PROFILE
 219         DO_PROFILE_INC(writecache_total_writes);
 220         if (!fsp->oplock_type) {
 221                 DO_PROFILE_INC(writecache_non_oplock_writes);
 222         }
 223 #endif
 224
 225         /*
 226          * If this file is level II oplocked then we need
 227          * to grab the shared memory lock and inform all
 228          * other files with a level II lock that they need
 229          * to flush their read caches. We keep the lock over
 230          * the shared memory area whilst doing this.
 231          */
 232
 233         release_level_2_oplocks_on_change(fsp);
 234
 235 #ifdef WITH_PROFILE
 236         if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
 237                 DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
 238 nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
 239                         profile_p->writecache_init_writes,
 240                         profile_p->writecache_abutted_writes,
 241                         profile_p->writecache_total_writes,
 242                         profile_p->writecache_non_oplock_writes,
 243                         profile_p->writecache_allocated_write_caches,
 244                         profile_p->writecache_num_write_caches,
 245                         profile_p->writecache_direct_writes,
 246                         profile_p->writecache_num_perfect_writes,
 247                         profile_p->writecache_read_hits ));
 248
 249                 DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
 250                         profile_p->writecache_flushed_writes[SEEK_FLUSH],
 251                         profile_p->writecache_flushed_writes[READ_FLUSH],
 252                         profile_p->writecache_flushed_writes[WRITE_FLUSH],
 253                         profile_p->writecache_flushed_writes[READRAW_FLUSH],
 254                         profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
 255                         profile_p->writecache_flushed_writes[CLOSE_FLUSH],
 256                         profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
 257         }
 258 #endif
 259
 260         if(!wcp) {
 261                 DO_PROFILE_INC(writecache_direct_writes);
 262                 total_written = real_write_file(fsp, data, pos, n);
 263                 if ((total_written != -1) && (pos + total_written > (SMB_OFF_T)fsp->size))
 264                         fsp->size = (SMB_BIG_UINT)(pos + total_written);
 265                 return total_written;
 266         }
 267
 268         DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f wcp->data_size=%u\n",
 269                 fsp->fsp_name, fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size));
 270
 271         fsp->pos = pos + n;
 272
 273         /*
 274          * If we have active cache and it isn't contiguous then we flush.
 275          * NOTE: There is a small problem with running out of disk ....
 276          */
 277
 278         if (wcp->data_size) {
 279
 280                 BOOL cache_flush_needed = False;
 281
 282                 if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
 283
 284                         /* ASCII art.... JRA.
 285
 286       +--------------+-----
 287       | Cached data  | Rest of allocated cache buffer....
 288       +--------------+-----
 289
 290             +-------------------+
 291             | Data to write     |
 292             +-------------------+
 293
 294                         */
 295
 296                         /*
 297                          * Start of write overlaps or abutts the existing data.
 298                          */
 299
 300                         size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
 301
 302                         memcpy(wcp->data + (pos - wcp->offset), data, data_used);
 303
 304                         /*
 305                          * Update the current buffer size with the new data.
 306                          */
 307
 308                         if(pos + data_used > wcp->offset + wcp->data_size)
 309                                 wcp->data_size = pos + data_used - wcp->offset;
 310
 311                         /*
 312                          * Update the file size if changed.
 313                          */
 314
 315                         if (wcp->offset + wcp->data_size > wcp->file_size) {
 316                                 wcp->file_size = wcp->offset + wcp->data_size;
 317                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 318                         }
 319
 320                         /*
 321                          * If we used all the data then
 322                          * return here.
 323                          */
 324
 325                         if(n == data_used)
 326                                 return n;
 327                         else
 328                                 cache_flush_needed = True;
 329
 330                         /*
 331                          * Move the start of data forward by the amount used,
 332                          * cut down the amount left by the same amount.
 333                          */
 334
 335                         data += data_used;
 336                         pos += data_used;
 337                         n -= data_used;
 338
 339                         DO_PROFILE_INC(writecache_abutted_writes);
 340                         total_written = data_used;
 341
 342                         write_path = 1;
 343
 344                 } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
 345                                         (pos + n <= wcp->offset + wcp->alloc_size)) {
 346
 347                         /* ASCII art.... JRA.
 348
 349                         +---------------+
 350                         | Cache buffer  |
 351                         +---------------+
 352
 353             +-------------------+
 354             | Data to write     |
 355             +-------------------+
 356
 357                         */
 358
 359                         /*
 360                          * End of write overlaps the existing data.
 361                          */
 362
 363                         size_t data_used = pos + n - wcp->offset;
 364
 365                         memcpy(wcp->data, data + n - data_used, data_used);
 366
 367                         /*
 368                          * Update the current buffer size with the new data.
 369                          */
 370
 371                         if(pos + n > wcp->offset + wcp->data_size)
 372                                 wcp->data_size = pos + n - wcp->offset;
 373
 374                         /*
 375                          * Update the file size if changed.
 376                          */
 377
 378                         if (wcp->offset + wcp->data_size > wcp->file_size) {
 379                                 wcp->file_size = wcp->offset + wcp->data_size;
 380                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 381                         }
 382
 383                         /*
 384                          * We don't need to move the start of data, but we
 385                          * cut down the amount left by the amount used.
 386                          */
 387
 388                         n -= data_used;
 389
 390                         /*
 391                          * We cannot have used all the data here.
 392                          */
 393
 394                         cache_flush_needed = True;
 395
 396                         DO_PROFILE_INC(writecache_abutted_writes);
 397                         total_written = data_used;
 398
 399                         write_path = 2;
 400
 401                 } else if ( (pos >= wcp->file_size) &&
 402                                         (wcp->offset + wcp->data_size == wcp->file_size) &&
 403                                         (pos > wcp->offset + wcp->data_size) &&
 404                                         (pos < wcp->offset + wcp->alloc_size) ) {
 405
 406                         /* ASCII art.... JRA.
 407
 408                        End of file ---->|
 409
 410                         +---------------+---------------+
 411                         | Cached data   | Cache buffer  |
 412                         +---------------+---------------+
 413
 414                                               +-------------------+
 415                                               | Data to write     |
 416                                               +-------------------+
 417
 418                         */
 419
 420                         /*
 421                          * Non-contiguous write part of which fits within
 422                          * the cache buffer and is extending the file
 423                          * and the cache contents reflect the current
 424                          * data up to the current end of the file.
 425                          */
 426
 427                         size_t data_used;
 428
 429                         if(pos + n <= wcp->offset + wcp->alloc_size)
 430                                 data_used = n;
 431                         else
 432                                 data_used = wcp->offset + wcp->alloc_size - pos;
 433
 434                         /*
 435                          * Fill in the non-continuous area with zeros.
 436                          */
 437
 438                         memset(wcp->data + wcp->data_size, '\0',
 439                                 pos - (wcp->offset + wcp->data_size) );
 440
 441                         memcpy(wcp->data + (pos - wcp->offset), data, data_used);
 442
 443                         /*
 444                          * Update the current buffer size with the new data.
 445                          */
 446
 447                         if(pos + data_used > wcp->offset + wcp->data_size)
 448                                 wcp->data_size = pos + data_used - wcp->offset;
 449
 450                         /*
 451                          * Update the file size if changed.
 452                          */
 453
 454                         if (wcp->offset + wcp->data_size > wcp->file_size) {
 455                                 wcp->file_size = wcp->offset + wcp->data_size;
 456                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 457                         }
 458
 459                         /*
 460                          * If we used all the data then
 461                          * return here.
 462                          */
 463
 464                         if(n == data_used)
 465                                 return n;
 466                         else
 467                                 cache_flush_needed = True;
 468
 469                         /*
 470                          * Move the start of data forward by the amount used,
 471                          * cut down the amount left by the same amount.
 472                          */
 473
 474                         data += data_used;
 475                         pos += data_used;
 476                         n -= data_used;
 477
 478                         DO_PROFILE_INC(writecache_abutted_writes);
 479                         total_written = data_used;
 480
 481                         write_path = 3;
 482
 483                 } else {
 484
 485                         /* ASCII art..... JRA.
 486
 487    Case 1).
 488
 489                         +---------------+---------------+
 490                         | Cached data   | Cache buffer  |
 491                         +---------------+---------------+
 492
 493                                                               +-------------------+
 494                                                               | Data to write     |
 495                                                               +-------------------+
 496
 497    Case 2).
 498
 499                            +---------------+---------------+
 500                            | Cached data   | Cache buffer  |
 501                            +---------------+---------------+
 502
 503    +-------------------+
 504    | Data to write     |
 505    +-------------------+
 506
 507     Case 3).
 508
 509                            +---------------+---------------+
 510                            | Cached data   | Cache buffer  |
 511                            +---------------+---------------+
 512
 513                   +-----------------------------------------------------+
 514                   | Data to write                                       |
 515                   +-----------------------------------------------------+
 516
 517                   */
 518
 519                         /*
 520                          * Write is bigger than buffer, or there is no overlap on the
 521                          * low or high ends.
 522                          */
 523
 524                         DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
 525 len = %u\n",fsp->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
 526
 527                         /*
 528                          * Update the file size if needed.
 529                          */
 530
 531                         if(pos + n > wcp->file_size) {
 532                                 wcp->file_size = pos + n;
 533                                 fsp->size = (SMB_BIG_UINT)wcp->file_size;
 534                         }
 535
 536                         /*
 537                          * If write would fit in the cache, and is larger than
 538                          * the data already in the cache, flush the cache and
 539                          * preferentially copy the data new data into it. Otherwise
 540                          * just write the data directly.
 541                          */
 542
 543                         if ( n <= wcp->alloc_size && n > wcp->data_size) {
 544                                 cache_flush_needed = True;
 545                         } else {
 546                                 ssize_t ret = real_write_file(fsp, data, pos, n);
 547
 548                                 /*
 549                                  * If the write overlaps the entire cache, then
 550                                  * discard the current contents of the cache.
 551                                  * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
 552                                  */
 553
 554                                 if ((pos <= wcp->offset) &&
 555                                                 (pos + n >= wcp->offset + wcp->data_size) ) {
 556                                         DEBUG(9,("write_file: discarding overwritten write \
 557 cache: fd = %d, off=%.0f, size=%u\n", fsp->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
 558                                         wcp->data_size = 0;
 559                                 }
 560
 561                                 DO_PROFILE_INC(writecache_direct_writes);
 562                                 if (ret == -1)
 563                                         return ret;
 564
 565                                 if (pos + ret > wcp->file_size) {
 566                                         wcp->file_size = pos + ret;
 567                                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 568                                 }
 569
 570                                 return ret;
 571                         }
 572
 573                         write_path = 4;
 574
 575                 }
 576
 577                 if(wcp->data_size > wcp->file_size) {
 578                         wcp->file_size = wcp->data_size;
 579                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 580                 }
 581
 582                 if (cache_flush_needed) {
 583                         DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
 584 n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
 585                                 write_path, fsp->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
 586                                 (double)wcp->offset, (unsigned int)wcp->data_size ));
 587
 588                         flush_write_cache(fsp, WRITE_FLUSH);
 589                 }
 590         }
 591
 592         /*
 593          * If the write request is bigger than the cache
 594          * size, write it all out.
 595          */
 596
 597         if (n > wcp->alloc_size ) {
 598                 ssize_t ret = real_write_file(fsp, data, pos, n);
 599                 if (ret == -1)
 600                         return -1;
 601
 602                 if (pos + ret > wcp->file_size) {
 603                         wcp->file_size = pos + n;
 604                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 605                 }
 606
 607                 DO_PROFILE_INC(writecache_direct_writes);
 608                 return total_written + n;
 609         }
 610
 611         /*
 612          * If there's any data left, cache it.
 613          */
 614
 615         if (n) {
 616 #ifdef WITH_PROFILE
 617                 if (wcp->data_size) {
 618                         DO_PROFILE_INC(writecache_abutted_writes);
 619                 } else {
 620                         DO_PROFILE_INC(writecache_init_writes);
 621                 }
 622 #endif
 623                 memcpy(wcp->data+wcp->data_size, data, n);
 624                 if (wcp->data_size == 0) {
 625                         wcp->offset = pos;
 626                         DO_PROFILE_INC(writecache_num_write_caches);
 627                 }
 628                 wcp->data_size += n;
 629
 630                 /*
 631                  * Update the file size if changed.
 632                  */
 633
 634                 if (wcp->offset + wcp->data_size > wcp->file_size) {
 635                         wcp->file_size = wcp->offset + wcp->data_size;
 636                         fsp->size = (SMB_BIG_UINT)wcp->file_size;
 637                 }
 638                 DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
 639                         (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
 640
 641                 total_written += n;
 642                 return total_written; /* .... that's a write :) */
 643         }
 644
 645         return total_written;
 646 }
 647
 648 /****************************************************************************
 649  Delete the write cache structure.
 650 ****************************************************************************/
 651
 652 void delete_write_cache(files_struct *fsp)
 653 {
 654         write_cache *wcp;
 655
 656         if(!fsp)
 657                 return;
 658
 659         if(!(wcp = fsp->wcp))
 660                 return;
 661
 662         DO_PROFILE_DEC(writecache_allocated_write_caches);
 663         allocated_write_caches--;
 664
 665         SMB_ASSERT(wcp->data_size == 0);
 666
 667         SAFE_FREE(wcp->data);
 668         SAFE_FREE(fsp->wcp);
 669
 670         DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
 671 }
 672
 673 /****************************************************************************
 674  Setup the write cache structure.
 675 ****************************************************************************/
 676
 677 static BOOL setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
 678 {
 679         ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
 680         write_cache *wcp;
 681
 682         if (allocated_write_caches >= MAX_WRITE_CACHES)
 683                 return False;
 684
 685         if(alloc_size == 0 || fsp->wcp)
 686                 return False;
 687
 688         if((wcp = (write_cache *)malloc(sizeof(write_cache))) == NULL) {
 689                 DEBUG(0,("setup_write_cache: malloc fail.\n"));
 690                 return False;
 691         }
 692
 693         wcp->file_size = file_size;
 694         wcp->offset = 0;
 695         wcp->alloc_size = alloc_size;
 696         wcp->data_size = 0;
 697         if((wcp->data = malloc(wcp->alloc_size)) == NULL) {
 698                 DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
 699                         (unsigned int)wcp->alloc_size ));
 700                 SAFE_FREE(wcp);
 701                 return False;
 702         }
 703
 704         memset(wcp->data, '\0', wcp->alloc_size );
 705
 706         fsp->wcp = wcp;
 707         DO_PROFILE_INC(writecache_allocated_write_caches);
 708         allocated_write_caches++;
 709
 710         DEBUG(10,("setup_write_cache: File %s allocated write cache size %u\n",
 711                 fsp->fsp_name, wcp->alloc_size ));
 712
 713         return True;
 714 }
 715
 716 /****************************************************************************
 717  Cope with a size change.
 718 ****************************************************************************/
 719
 720 void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
 721 {
 722         fsp->size = (SMB_BIG_UINT)file_size;
 723         if(fsp->wcp) {
 724                 /* The cache *must* have been flushed before we do this. */
 725                 if (fsp->wcp->data_size != 0) {
 726                         pstring msg;
 727                         slprintf(msg, sizeof(msg)-1, "set_filelen_write_cache: size change \
 728 on file %s with write cache size = %u\n", fsp->fsp_name, fsp->wcp->data_size );
 729                         smb_panic(msg);
 730                 }
 731                 fsp->wcp->file_size = file_size;
 732         }
 733 }
 734
 735 /*******************************************************************
 736  Flush a write cache struct to disk.
 737 ********************************************************************/
 738
 739 ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
 740 {
 741         write_cache *wcp = fsp->wcp;
 742         size_t data_size;
 743         ssize_t ret;
 744
 745         if(!wcp || !wcp->data_size)
 746                 return 0;
 747
 748         data_size = wcp->data_size;
 749         wcp->data_size = 0;
 750
 751         DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
 752
 753         DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
 754                 fsp->fd, (double)wcp->offset, (unsigned int)data_size));
 755
 756 #ifdef WITH_PROFILE
 757         if(data_size == wcp->alloc_size)
 758                 DO_PROFILE_INC(writecache_num_perfect_writes);
 759 #endif
 760
 761         ret = real_write_file(fsp, wcp->data, wcp->offset, data_size);
 762
 763         /*
 764          * Ensure file size if kept up to date if write extends file.
 765          */
 766
 767         if ((ret != -1) && (wcp->offset + ret > wcp->file_size))
 768                 wcp->file_size = wcp->offset + ret;
 769
 770         return ret;
 771 }
 772
 773 /*******************************************************************
 774 sync a file
 775 ********************************************************************/
 776
 777 void sync_file(connection_struct *conn, files_struct *fsp)
 778 {
 779         if(lp_strict_sync(SNUM(conn)) && fsp->fd != -1) {
 780                 flush_write_cache(fsp, SYNC_FLUSH);
 781                 SMB_VFS_FSYNC(fsp,fsp->fd);
 782         }
 783 }
 784
 785
 786 /************************************************************
 787  Perform a stat whether a valid fd or not.
 788 ************************************************************/
 789
 790 int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
 791 {
 792         if (fsp->fd == -1)
 793                 return SMB_VFS_STAT(fsp->conn, fsp->fsp_name, pst);
 794         else
 795                 return SMB_VFS_FSTAT(fsp,fsp->fd, pst);
 796 }