ntoskrnl/cc/view.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 1998, 1999, 2000, 2001 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /* $Id$
  20  *
  21  * PROJECT:         ReactOS kernel
  22  * FILE:            ntoskrnl/cc/view.c
  23  * PURPOSE:         Cache manager
  24  * PROGRAMMER:      David Welch (welch@mcmail.com)
  25  * PORTABILITY:     Checked
  26  * UPDATE HISTORY:
  27  *                  Created 22/05/98
  28  */
  29
  30 /* NOTES **********************************************************************
  31  *
  32  * This is not the NT implementation of a file cache nor anything much like
  33  * it.
  34  *
  35  * The general procedure for a filesystem to implement a read or write
  36  * dispatch routine is as follows
  37  *
  38  * (1) If caching for the FCB hasn't been initiated then so do by calling
  39  * CcInitializeFileCache.
  40  *
  41  * (2) For each 4k region which is being read or written obtain a cache page
  42  * by calling CcRequestCachePage.
  43  *
  44  * (3) If either the page is being read or not completely written, and it is
  45  * not up to date then read its data from the underlying medium. If the read
  46  * fails then call CcReleaseCachePage with VALID as FALSE and return a error.
  47  *
  48  * (4) Copy the data into or out of the page as necessary.
  49  *
  50  * (5) Release the cache page
  51  */
  52 /* INCLUDES ******************************************************************/
  53
  54 #include <ddk/ntddk.h>
  55 #include <ddk/ntifs.h>
  56 #include <internal/mm.h>
  57 #include <internal/cc.h>
  58 #include <internal/pool.h>
  59 #include <ntos/minmax.h>
  60
  61 #define NDEBUG
  62 #include <internal/debug.h>
  63
  64 /* GLOBALS *******************************************************************/
  65
  66 #define ROUND_UP(N, S) ((((N) + (S) - 1) / (S)) * (S))
  67 #define ROUND_DOWN(N, S) (((N) % (S)) ? ROUND_UP(N, S) - S : N)
  68
  69 #define TAG_CSEG  TAG('C', 'S', 'E', 'G')
  70 #define TAG_BCB   TAG('B', 'C', 'B', ' ')
  71
  72 static LIST_ENTRY DirtySegmentListHead;
  73 static LIST_ENTRY CacheSegmentListHead;
  74 static LIST_ENTRY CacheSegmentLRUListHead;
  75
  76 static FAST_MUTEX ViewLock;
  77
  78 void * alloca(size_t size);
  79
  80 NTSTATUS STDCALL
  81 CcRosInternalFreeCacheSegment(PCACHE_SEGMENT CacheSeg);
  82
  83 /* FUNCTIONS *****************************************************************/
  84
  85 NTSTATUS STATIC
  86 CcRosFlushCacheSegment(PCACHE_SEGMENT CacheSegment)
  87 {
  88   NTSTATUS Status;
  89   KIRQL oldIrql;
  90   Status = WriteCacheSegment(CacheSegment);
  91   if (NT_SUCCESS(Status))
  92     {
  93       ExAcquireFastMutex(&ViewLock);
  94       KeAcquireSpinLock(&CacheSegment->Bcb->BcbLock, &oldIrql);
  95       CacheSegment->Dirty = FALSE;
  96       RemoveEntryList(&CacheSegment->DirtySegmentListEntry);
  97       CacheSegment->ReferenceCount--;
  98       KeReleaseSpinLock(&CacheSegment->Bcb->BcbLock, oldIrql);
  99       ExReleaseFastMutex(&ViewLock);
 100     }
 101   return(Status);
 102 }
 103
 104 NTSTATUS
 105 CcRosFlushDirtyPages(ULONG Target, PULONG Count)
 106 {
 107   PLIST_ENTRY current_entry;
 108   PCACHE_SEGMENT current;
 109   ULONG PagesPerSegment;
 110   BOOLEAN Locked;
 111   NTSTATUS Status;
 112
 113   DPRINT("CcRosFlushDirtyPages(Target %d)\n", Target);
 114
 115   (*Count) = 0;
 116
 117   ExAcquireFastMutex(&ViewLock);
 118   current_entry = DirtySegmentListHead.Flink;
 119   while (current_entry != &DirtySegmentListHead && Target > 0)
 120     {
 121       current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT,
 122                                   DirtySegmentListEntry);
 123       current_entry = current_entry->Flink;
 124       Locked = ExTryToAcquireFastMutex(&current->Lock);
 125       if (!Locked)
 126         {
 127           continue;
 128         }
 129       assert(current->Dirty);
 130       if (current->ReferenceCount > 1)
 131         {
 132           ExReleaseFastMutex(&current->Lock);
 133           continue;
 134         }
 135       ExReleaseFastMutex(&ViewLock);
 136       PagesPerSegment = current->Bcb->CacheSegmentSize / PAGE_SIZE;
 137       Status = CcRosFlushCacheSegment(current);
 138       ExReleaseFastMutex(&current->Lock);
 139       if (!NT_SUCCESS(Status))
 140       {
 141          DPRINT1("CC: Failed to flush cache segment.\n");
 142       }
 143       else
 144       {
 145          (*Count) += PagesPerSegment;
 146          Target -= PagesPerSegment;
 147       }
 148       ExAcquireFastMutex(&ViewLock);
 149       current_entry = DirtySegmentListHead.Flink;
 150     }
 151   ExReleaseFastMutex(&ViewLock);
 152   DPRINT("CcRosTrimCache() finished\n");
 153   return(STATUS_SUCCESS);
 154 }
 155
 156 NTSTATUS
 157 CcRosTrimCache(ULONG Target, ULONG Priority, PULONG NrFreed)
 158 /*
 159  * FUNCTION: Try to free some memory from the file cache.
 160  * ARGUMENTS:
 161  *       Target - The number of pages to be freed.
 162  *       Priority - The priority of free (currently unused).
 163  *       NrFreed - Points to a variable where the number of pages
 164  *                 actually freed is returned.
 165  */
 166 {
 167   PLIST_ENTRY current_entry;
 168   PCACHE_SEGMENT current;
 169   ULONG PagesPerSegment;
 170   ULONG PagesFreed;
 171   KIRQL oldIrql;
 172   LIST_ENTRY FreeList;
 173
 174   DPRINT("CcRosTrimCache(Target %d)\n", Target);
 175
 176   *NrFreed = 0;
 177
 178   InitializeListHead(&FreeList);
 179
 180   ExAcquireFastMutex(&ViewLock);
 181   current_entry = CacheSegmentLRUListHead.Flink;
 182   while (current_entry != &CacheSegmentLRUListHead && Target > 0)
 183     {
 184       current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT,
 185                                   CacheSegmentLRUListEntry);
 186       current_entry = current_entry->Flink;
 187
 188       KeAcquireSpinLock(&current->Bcb->BcbLock, &oldIrql);
 189       if (current->ReferenceCount == 0)
 190       {
 191          RemoveEntryList(&current->BcbSegmentListEntry);
 192          KeReleaseSpinLock(&current->Bcb->BcbLock, oldIrql);
 193          RemoveEntryList(&current->CacheSegmentListEntry);
 194          RemoveEntryList(&current->CacheSegmentLRUListEntry);
 195          InsertHeadList(&FreeList, &current->BcbSegmentListEntry);
 196       }
 197       else
 198       {
 199          KeReleaseSpinLock(&current->Bcb->BcbLock, oldIrql);
 200       }
 201   }
 202   ExReleaseFastMutex(&ViewLock);
 203
 204   while (!IsListEmpty(&FreeList))
 205   {
 206      current_entry = RemoveHeadList(&FreeList);
 207      current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT,
 208                                  BcbSegmentListEntry);
 209      PagesPerSegment = current->Bcb->CacheSegmentSize / PAGE_SIZE;
 210      PagesFreed = min(PagesPerSegment, Target);
 211      Target -= PagesFreed;
 212      (*NrFreed) += PagesFreed;
 213      CcRosInternalFreeCacheSegment(current);
 214   }
 215
 216   DPRINT("CcRosTrimCache() finished\n");
 217   return(STATUS_SUCCESS);
 218 }
 219
 220 NTSTATUS STDCALL
 221 CcRosReleaseCacheSegment(PBCB Bcb,
 222                          PCACHE_SEGMENT CacheSeg,
 223                          BOOLEAN Valid,
 224                          BOOLEAN Dirty,
 225                          BOOLEAN Mapped)
 226 {
 227   BOOLEAN WasDirty = CacheSeg->Dirty;
 228   KIRQL oldIrql;
 229
 230   DPRINT("CcReleaseCacheSegment(Bcb %x, CacheSeg %x, Valid %d)\n",
 231          Bcb, CacheSeg, Valid);
 232
 233   CacheSeg->Valid = Valid;
 234   CacheSeg->Dirty = CacheSeg->Dirty || Dirty;
 235
 236   ExAcquireFastMutex(&ViewLock);
 237   if (!WasDirty && CacheSeg->Dirty)
 238     {
 239       InsertTailList(&DirtySegmentListHead, &CacheSeg->DirtySegmentListEntry);
 240     }
 241   RemoveEntryList(&CacheSeg->CacheSegmentLRUListEntry);
 242   InsertTailList(&CacheSegmentLRUListHead, &CacheSeg->CacheSegmentLRUListEntry);
 243
 244   if (Mapped)
 245   {
 246      CacheSeg->MappedCount++;
 247   }
 248   KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 249   CacheSeg->ReferenceCount--;
 250   if (Mapped && CacheSeg->MappedCount == 1)
 251   {
 252       CacheSeg->ReferenceCount++;
 253   }
 254   if (!WasDirty && CacheSeg->Dirty)
 255   {
 256       CacheSeg->ReferenceCount++;
 257   }
 258   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 259   ExReleaseFastMutex(&ViewLock);
 260   ExReleaseFastMutex(&CacheSeg->Lock);
 261
 262   return(STATUS_SUCCESS);
 263 }
 264
 265 PCACHE_SEGMENT CcRosLookupCacheSegment(PBCB Bcb, ULONG FileOffset)
 266 {
 267   PLIST_ENTRY current_entry;
 268   PCACHE_SEGMENT current;
 269   KIRQL oldIrql;
 270
 271   DPRINT("CcRosLookupCacheSegment(Bcb %x, FileOffset %d)\n", Bcb, FileOffset);
 272
 273   KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 274   current_entry = Bcb->BcbSegmentListHead.Flink;
 275   while (current_entry != &Bcb->BcbSegmentListHead)
 276     {
 277       current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT,
 278                                   BcbSegmentListEntry);
 279       if (current->FileOffset <= FileOffset &&
 280           (current->FileOffset + Bcb->CacheSegmentSize) > FileOffset)
 281         {
 282           current->ReferenceCount++;
 283           KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 284           return(current);
 285         }
 286       current_entry = current_entry->Flink;
 287     }
 288   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 289   return(NULL);
 290 }
 291
 292 NTSTATUS
 293 CcRosMarkDirtyCacheSegment(PBCB Bcb, ULONG FileOffset)
 294 {
 295   PCACHE_SEGMENT CacheSeg;
 296   KIRQL oldIrql;
 297
 298   DPRINT("CcRosMarkDirtyCacheSegment(Bcb %x, FileOffset %d)\n", Bcb, FileOffset);
 299
 300   CacheSeg = CcRosLookupCacheSegment(Bcb, FileOffset);
 301   if (CacheSeg == NULL)
 302     {
 303       KeBugCheck(0);
 304     }
 305   ExAcquireFastMutex(&CacheSeg->Lock);
 306   if (!CacheSeg->Dirty)
 307     {
 308       ExAcquireFastMutex(&ViewLock);
 309       InsertTailList(&DirtySegmentListHead, &CacheSeg->DirtySegmentListEntry);
 310       ExReleaseFastMutex(&ViewLock);
 311     }
 312   else
 313   {
 314      KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 315      CacheSeg->ReferenceCount--;
 316      KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 317   }
 318
 319
 320   CacheSeg->Dirty = TRUE;
 321   ExReleaseFastMutex(&CacheSeg->Lock);
 322
 323   return(STATUS_SUCCESS);
 324 }
 325
 326 NTSTATUS
 327 CcRosUnmapCacheSegment(PBCB Bcb, ULONG FileOffset, BOOLEAN NowDirty)
 328 {
 329   PCACHE_SEGMENT CacheSeg;
 330   BOOLEAN WasDirty;
 331   KIRQL oldIrql;
 332
 333   DPRINT("CcRosUnmapCacheSegment(Bcb %x, FileOffset %d, NowDirty %d)\n",
 334           Bcb, FileOffset, NowDirty);
 335
 336   CacheSeg = CcRosLookupCacheSegment(Bcb, FileOffset);
 337   if (CacheSeg == NULL)
 338     {
 339       return(STATUS_UNSUCCESSFUL);
 340     }
 341   ExAcquireFastMutex(&CacheSeg->Lock);
 342
 343   WasDirty = CacheSeg->Dirty;
 344   CacheSeg->Dirty = CacheSeg->Dirty || NowDirty;
 345
 346   CacheSeg->MappedCount--;
 347
 348   if (!WasDirty && NowDirty)
 349   {
 350      ExAcquireFastMutex(&ViewLock);
 351      InsertTailList(&DirtySegmentListHead, &CacheSeg->DirtySegmentListEntry);
 352      ExReleaseFastMutex(&ViewLock);
 353   }
 354
 355   KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 356   CacheSeg->ReferenceCount--;
 357   if (!WasDirty && NowDirty)
 358   {
 359      CacheSeg->ReferenceCount++;
 360   }
 361   if (CacheSeg->MappedCount == 0)
 362   {
 363      CacheSeg->ReferenceCount--;
 364   }
 365   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 366
 367   ExReleaseFastMutex(&CacheSeg->Lock);
 368   return(STATUS_SUCCESS);
 369 }
 370
 371 NTSTATUS STATIC
 372 CcRosCreateCacheSegment(PBCB Bcb,
 373                         ULONG FileOffset,
 374                         PCACHE_SEGMENT* CacheSeg,
 375                         BOOLEAN Lock)
 376 {
 377   ULONG i;
 378   PCACHE_SEGMENT current;
 379   PLIST_ENTRY current_entry;
 380   NTSTATUS Status;
 381   KIRQL oldIrql;
 382
 383   DPRINT("CcRosCreateCacheSegment()\n");
 384
 385   current = ExAllocatePoolWithTag(NonPagedPool, sizeof(CACHE_SEGMENT),
 386                                   TAG_CSEG);
 387   current->Valid = FALSE;
 388   current->Dirty = FALSE;
 389   current->FileOffset = ROUND_DOWN(FileOffset, Bcb->CacheSegmentSize);
 390   current->Bcb = Bcb;
 391   current->MappedCount = 0;
 392   current->DirtySegmentListEntry.Flink = NULL;
 393   current->DirtySegmentListEntry.Blink = NULL;
 394   current->ReferenceCount = 1;
 395   ExInitializeFastMutex(&current->Lock);
 396   ExAcquireFastMutex(&current->Lock);
 397   ExAcquireFastMutex(&ViewLock);
 398
 399   *CacheSeg = current;
 400   /* There is window between the call to CcRosLookupCacheSegment
 401    * and CcRosCreateCacheSegment. We must check if a segment on
 402    * the fileoffset exist. If there exist a segment, we release
 403    * our new created segment and return the existing one.
 404    */
 405   KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 406   current_entry = Bcb->BcbSegmentListHead.Flink;
 407   while (current_entry != &Bcb->BcbSegmentListHead)
 408   {
 409      current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT,
 410                                  BcbSegmentListEntry);
 411      if (current->FileOffset <= FileOffset &&
 412         (current->FileOffset + Bcb->CacheSegmentSize) > FileOffset)
 413      {
 414         current->ReferenceCount++;
 415         KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 416         ExReleaseFastMutex(&(*CacheSeg)->Lock);
 417         ExReleaseFastMutex(&ViewLock);
 418         ExFreePool(*CacheSeg);
 419         *CacheSeg = current;
 420         if (Lock)
 421         {
 422           ExAcquireFastMutex(&current->Lock);
 423         }
 424         return STATUS_SUCCESS;
 425      }
 426      current_entry = current_entry->Flink;
 427   }
 428   /* There was no existing segment. */
 429   current = *CacheSeg;
 430   InsertTailList(&Bcb->BcbSegmentListHead, &current->BcbSegmentListEntry);
 431   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 432   InsertTailList(&CacheSegmentListHead, &current->CacheSegmentListEntry);
 433   InsertTailList(&CacheSegmentLRUListHead, &current->CacheSegmentLRUListEntry);
 434   ExReleaseFastMutex(&ViewLock);
 435
 436   MmLockAddressSpace(MmGetKernelAddressSpace());
 437   current->BaseAddress = NULL;
 438   Status = MmCreateMemoryArea(NULL,
 439                               MmGetKernelAddressSpace(),
 440                               MEMORY_AREA_CACHE_SEGMENT,
 441                               &current->BaseAddress,
 442                               Bcb->CacheSegmentSize,
 443                               PAGE_READWRITE,
 444                               (PMEMORY_AREA*)&current->MemoryArea,
 445                               FALSE);
 446   MmUnlockAddressSpace(MmGetKernelAddressSpace());
 447   if (!NT_SUCCESS(Status))
 448   {
 449      KeBugCheck(0);
 450   }
 451   for (i = 0; i < (Bcb->CacheSegmentSize / PAGE_SIZE); i++)
 452   {
 453      PHYSICAL_ADDRESS Page;
 454
 455      Status = MmRequestPageMemoryConsumer(MC_CACHE, TRUE, &Page);
 456      if (!NT_SUCCESS(Status))
 457      {
 458         KeBugCheck(0);
 459      }
 460
 461      Status = MmCreateVirtualMapping(NULL,
 462                                      current->BaseAddress + (i * PAGE_SIZE),
 463                                      PAGE_READWRITE,
 464                                      Page,
 465                                      TRUE);
 466      if (!NT_SUCCESS(Status))
 467      {
 468         KeBugCheck(0);
 469      }
 470   }
 471   if (!Lock)
 472   {
 473      ExReleaseFastMutex(&current->Lock);
 474   }
 475
 476   return(STATUS_SUCCESS);
 477 }
 478
 479 NTSTATUS
 480 CcRosGetCacheSegmentChain(PBCB Bcb,
 481                           ULONG FileOffset,
 482                           ULONG Length,
 483                           PCACHE_SEGMENT* CacheSeg)
 484 {
 485   PCACHE_SEGMENT current;
 486   ULONG i;
 487   PCACHE_SEGMENT* CacheSegList;
 488   PCACHE_SEGMENT Previous = NULL;
 489
 490   DPRINT("CcRosGetCacheSegmentChain()\n");
 491
 492   Length = ROUND_UP(Length, Bcb->CacheSegmentSize);
 493
 494   CacheSegList = alloca(sizeof(PCACHE_SEGMENT) *
 495                         (Length / Bcb->CacheSegmentSize));
 496
 497   /*
 498    * Look for a cache segment already mapping the same data.
 499    */
 500   for (i = 0; i < (Length / Bcb->CacheSegmentSize); i++)
 501     {
 502       ULONG CurrentOffset = FileOffset + (i * Bcb->CacheSegmentSize);
 503       current = CcRosLookupCacheSegment(Bcb, CurrentOffset);
 504       if (current != NULL)
 505         {
 506           CacheSegList[i] = current;
 507         }
 508       else
 509         {
 510           CcRosCreateCacheSegment(Bcb, CurrentOffset, &current, FALSE);
 511           CacheSegList[i] = current;
 512         }
 513     }
 514
 515   for (i = 0; i < (Length / Bcb->CacheSegmentSize); i++)
 516     {
 517       ExAcquireFastMutex(&CacheSegList[i]->Lock);
 518       if (i == 0)
 519         {
 520           *CacheSeg = CacheSegList[i];
 521           Previous = CacheSegList[i];
 522         }
 523       else
 524         {
 525           Previous->NextInChain = CacheSegList[i];
 526           Previous = CacheSegList[i];
 527         }
 528     }
 529   Previous->NextInChain = NULL;
 530
 531   return(STATUS_SUCCESS);
 532 }
 533
 534 NTSTATUS
 535 CcRosGetCacheSegment(PBCB Bcb,
 536                      ULONG FileOffset,
 537                      PULONG BaseOffset,
 538                      PVOID* BaseAddress,
 539                      PBOOLEAN UptoDate,
 540                      PCACHE_SEGMENT* CacheSeg)
 541 {
 542    PCACHE_SEGMENT current;
 543    NTSTATUS Status;
 544
 545    DPRINT("CcRosGetCacheSegment()\n");
 546
 547    /*
 548     * Look for a cache segment already mapping the same data.
 549     */
 550    current = CcRosLookupCacheSegment(Bcb, FileOffset);
 551    if (current != NULL)
 552    {
 553       ExAcquireFastMutex(&current->Lock);
 554    }
 555    else
 556    {
 557      /*
 558       * Otherwise create a new segment.
 559       */
 560       Status = CcRosCreateCacheSegment(Bcb, FileOffset, &current, TRUE);
 561    }
 562    /*
 563     * Return information about the segment to the caller.
 564     */
 565    *UptoDate = current->Valid;
 566    *BaseAddress = current->BaseAddress;
 567    DPRINT("*BaseAddress 0x%.8X\n", *BaseAddress);
 568    *CacheSeg = current;
 569    *BaseOffset = current->FileOffset;
 570    return(STATUS_SUCCESS);
 571 }
 572
 573 NTSTATUS STDCALL
 574 CcRosRequestCacheSegment(PBCB Bcb,
 575                       ULONG FileOffset,
 576                       PVOID* BaseAddress,
 577                       PBOOLEAN UptoDate,
 578                       PCACHE_SEGMENT* CacheSeg)
 579 /*
 580  * FUNCTION: Request a page mapping for a BCB
 581  */
 582 {
 583   ULONG BaseOffset;
 584
 585   if ((FileOffset % Bcb->CacheSegmentSize) != 0)
 586     {
 587       CPRINT("Bad fileoffset %x should be multiple of %x",
 588         FileOffset, Bcb->CacheSegmentSize);
 589       KeBugCheck(0);
 590     }
 591
 592   return(CcRosGetCacheSegment(Bcb,
 593                            FileOffset,
 594                            &BaseOffset,
 595                            BaseAddress,
 596                            UptoDate,
 597                            CacheSeg));
 598 }
 599
 600 STATIC VOID
 601 CcFreeCachePage(PVOID Context, MEMORY_AREA* MemoryArea, PVOID Address,
 602                 PHYSICAL_ADDRESS PhysAddr, SWAPENTRY SwapEntry, BOOLEAN Dirty)
 603 {
 604   assert(SwapEntry == 0);
 605   if (PhysAddr.QuadPart != 0)
 606     {
 607       MmReleasePageMemoryConsumer(MC_CACHE, PhysAddr);
 608     }
 609 }
 610
 611 NTSTATUS STDCALL
 612 CcRosInternalFreeCacheSegment(PCACHE_SEGMENT CacheSeg)
 613 /*
 614  * FUNCTION: Releases a cache segment associated with a BCB
 615  */
 616 {
 617
 618   DPRINT("Freeing cache segment %x\n", CacheSeg);
 619
 620   MmLockAddressSpace(MmGetKernelAddressSpace());
 621   MmFreeMemoryArea(MmGetKernelAddressSpace(),
 622                    CacheSeg->BaseAddress,
 623                    CacheSeg->Bcb->CacheSegmentSize,
 624                    CcFreeCachePage,
 625                    NULL);
 626   MmUnlockAddressSpace(MmGetKernelAddressSpace());
 627   ExFreePool(CacheSeg);
 628   return(STATUS_SUCCESS);
 629 }
 630
 631 NTSTATUS STDCALL
 632 CcRosFreeCacheSegment(PBCB Bcb, PCACHE_SEGMENT CacheSeg)
 633 {
 634   NTSTATUS Status;
 635   KIRQL oldIrql;
 636
 637   DPRINT("CcRosFreeCacheSegment(Bcb %x, CacheSeg %x)\n",
 638          Bcb, CacheSeg);
 639
 640   ExAcquireFastMutex(&ViewLock);
 641   KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 642   RemoveEntryList(&CacheSeg->BcbSegmentListEntry);
 643   RemoveEntryList(&CacheSeg->CacheSegmentListEntry);
 644   RemoveEntryList(&CacheSeg->CacheSegmentLRUListEntry);
 645   if (CacheSeg->Dirty)
 646   {
 647      RemoveEntryList(&CacheSeg->DirtySegmentListEntry);
 648   }
 649   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 650   ExReleaseFastMutex(&ViewLock);
 651
 652   Status = CcRosInternalFreeCacheSegment(CacheSeg);
 653   return(Status);
 654 }
 655
 656 VOID STDCALL
 657 CcFlushCache(IN PSECTION_OBJECT_POINTERS SectionObjectPointers,
 658              IN PLARGE_INTEGER FileOffset OPTIONAL,
 659              IN ULONG Length,
 660              OUT PIO_STATUS_BLOCK IoStatus)
 661 {
 662    PBCB Bcb;
 663    LARGE_INTEGER Offset;
 664    PCACHE_SEGMENT current;
 665    NTSTATUS Status;
 666    KIRQL oldIrql;
 667
 668    DPRINT("CcFlushCache(SectionObjectPointers %x, FileOffset %x, Length %d, IoStatus %x)\n",
 669            SectionObjectPointers, FileOffset, Length, IoStatus);
 670
 671    if (SectionObjectPointers && SectionObjectPointers->SharedCacheMap)
 672    {
 673       Bcb = (PBCB)SectionObjectPointers->SharedCacheMap;
 674       if (FileOffset)
 675       {
 676          Offset = *FileOffset;
 677       }
 678       else
 679       {
 680          Offset.QuadPart = 0LL;
 681          Length = Bcb->FileSize.u.LowPart;
 682       }
 683
 684       if (IoStatus)
 685       {
 686          IoStatus->Status = STATUS_SUCCESS;
 687          IoStatus->Information = 0;
 688       }
 689
 690       while (Length > 0)
 691       {
 692          current = CcRosLookupCacheSegment (Bcb, Offset.u.LowPart);
 693          if (current != NULL)
 694          {
 695             ExAcquireFastMutex(&current->Lock);
 696             if (current->Dirty)
 697             {
 698                Status = CcRosFlushCacheSegment(current);
 699                if (!NT_SUCCESS(Status) && IoStatus != NULL)
 700                {
 701                    IoStatus->Status = Status;
 702                }
 703             }
 704             ExReleaseFastMutex(&current->Lock);
 705             KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 706             current->ReferenceCount--;
 707             KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 708          }
 709
 710          Offset.QuadPart += Bcb->CacheSegmentSize;
 711          if (Length > Bcb->CacheSegmentSize)
 712          {
 713             Length -= Bcb->CacheSegmentSize;
 714          }
 715          else
 716          {
 717             Length = 0;
 718          }
 719       }
 720    }
 721    else
 722    {
 723       if (IoStatus)
 724       {
 725          IoStatus->Status = STATUS_INVALID_PARAMETER;
 726       }
 727    }
 728 }
 729
 730 NTSTATUS STDCALL
 731 CcRosDeleteFileCache(PFILE_OBJECT FileObject, PBCB Bcb)
 732 /*
 733  * FUNCTION: Releases the BCB associated with a file object
 734  */
 735 {
 736    PLIST_ENTRY current_entry;
 737    PCACHE_SEGMENT current;
 738    NTSTATUS Status;
 739    LIST_ENTRY FreeList;
 740    KIRQL oldIrql;
 741
 742    DPRINT("CcRosDeleteFileCache(FileObject %x, Bcb %x)\n",
 743           Bcb->FileObject, Bcb);
 744
 745    ExReleaseFastMutex(&ViewLock);
 746
 747    CcFlushCache(FileObject->SectionObjectPointers, NULL, 0, NULL);
 748
 749    ExAcquireFastMutex(&ViewLock);
 750
 751    if (Bcb->RefCount == 0)
 752    {
 753       MmFreeSectionSegments(Bcb->FileObject);
 754
 755       /*
 756        * Release all cache segments.
 757        */
 758       InitializeListHead(&FreeList);
 759
 760       FileObject->SectionObjectPointers->SharedCacheMap = NULL;
 761       KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
 762       current_entry = Bcb->BcbSegmentListHead.Flink;
 763       while (!IsListEmpty(&Bcb->BcbSegmentListHead))
 764       {
 765          current_entry = RemoveTailList(&Bcb->BcbSegmentListHead);
 766          current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT, BcbSegmentListEntry);
 767          RemoveEntryList(&current->CacheSegmentListEntry);
 768          RemoveEntryList(&current->CacheSegmentLRUListEntry);
 769          if (current->Dirty)
 770          {
 771             RemoveEntryList(&current->DirtySegmentListEntry);
 772          }
 773          InsertHeadList(&FreeList, &current->BcbSegmentListEntry);
 774
 775       }
 776       KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
 777       while (!IsListEmpty(&FreeList))
 778       {
 779          current_entry = RemoveTailList(&FreeList);
 780          current = CONTAINING_RECORD(current_entry, CACHE_SEGMENT, BcbSegmentListEntry);
 781          Status = CcRosInternalFreeCacheSegment(current);
 782       }
 783
 784       ObDereferenceObject (Bcb->FileObject);
 785       ExFreePool(Bcb);
 786    }
 787    return(STATUS_SUCCESS);
 788 }
 789
 790 VOID CcRosReferenceCache(PFILE_OBJECT FileObject)
 791 {
 792   PBCB Bcb;
 793   ExAcquireFastMutex(&ViewLock);
 794   Bcb = (PBCB)FileObject->SectionObjectPointers->SharedCacheMap;
 795   Bcb->RefCount++;
 796   ExReleaseFastMutex(&ViewLock);
 797 }
 798
 799 VOID CcRosDereferenceCache(PFILE_OBJECT FileObject)
 800 {
 801   PBCB Bcb;
 802   ExAcquireFastMutex(&ViewLock);
 803   Bcb = (PBCB)FileObject->SectionObjectPointers->SharedCacheMap;
 804   Bcb->RefCount--;
 805   if (Bcb->RefCount == 0)
 806   {
 807      CcRosDeleteFileCache(FileObject, Bcb);
 808   }
 809   ExReleaseFastMutex(&ViewLock);
 810 }
 811
 812 NTSTATUS STDCALL
 813 CcRosReleaseFileCache(PFILE_OBJECT FileObject, PBCB Bcb)
 814 /*
 815  * FUNCTION: Called by the file system when a handle to a file object
 816  * has been closed.
 817  */
 818 {
 819   ExAcquireFastMutex(&ViewLock);
 820
 821   if (FileObject->SectionObjectPointers->SharedCacheMap != NULL)
 822   {
 823     if (FileObject->PrivateCacheMap != NULL)
 824     {
 825       FileObject->PrivateCacheMap = NULL;
 826       Bcb->RefCount--;
 827     }
 828     if (Bcb->RefCount == 0)
 829     {
 830       CcRosDeleteFileCache(FileObject, Bcb);
 831     }
 832   }
 833   ExReleaseFastMutex(&ViewLock);
 834   return(STATUS_SUCCESS);
 835 }
 836
 837 NTSTATUS STDCALL
 838 CcRosInitializeFileCache(PFILE_OBJECT FileObject,
 839                          PBCB* Bcb,
 840                          ULONG CacheSegmentSize)
 841 /*
 842  * FUNCTION: Initializes a BCB for a file object
 843  */
 844 {
 845    DPRINT("CcRosInitializeFileCache(FileObject %x, *Bcb %x, CacheSegmentSize %d)\n",
 846            FileObject, Bcb, CacheSegmentSize);
 847
 848    ExAcquireFastMutex(&ViewLock);
 849
 850    if (*Bcb == NULL)
 851    {
 852       (*Bcb) = ExAllocatePoolWithTag(NonPagedPool, sizeof(BCB), TAG_BCB);
 853       if ((*Bcb) == NULL)
 854       {
 855         return(STATUS_UNSUCCESSFUL);
 856       }
 857
 858       ObReferenceObjectByPointer(FileObject,
 859                                  FILE_ALL_ACCESS,
 860                                  NULL,
 861                                  KernelMode);
 862       (*Bcb)->FileObject = FileObject;
 863       (*Bcb)->CacheSegmentSize = CacheSegmentSize;
 864       if (FileObject->FsContext)
 865       {
 866          (*Bcb)->AllocationSize =
 867            ((REACTOS_COMMON_FCB_HEADER*)FileObject->FsContext)->AllocationSize;
 868          (*Bcb)->FileSize =
 869            ((REACTOS_COMMON_FCB_HEADER*)FileObject->FsContext)->FileSize;
 870       }
 871       KeInitializeSpinLock(&(*Bcb)->BcbLock);
 872       InitializeListHead(&(*Bcb)->BcbSegmentListHead);
 873       FileObject->SectionObjectPointers->SharedCacheMap = *Bcb;
 874    }
 875    if (FileObject->PrivateCacheMap == NULL)
 876    {
 877       FileObject->PrivateCacheMap = *Bcb;
 878       (*Bcb)->RefCount++;
 879    }
 880    ExReleaseFastMutex(&ViewLock);
 881
 882    return(STATUS_SUCCESS);
 883 }
 884
 885 PFILE_OBJECT STDCALL
 886 CcGetFileObjectFromSectionPtrs(IN PSECTION_OBJECT_POINTERS SectionObjectPointers)
 887 {
 888    PBCB Bcb;
 889    if (SectionObjectPointers && SectionObjectPointers->SharedCacheMap)
 890    {
 891       Bcb = (PBCB)SectionObjectPointers->SharedCacheMap;
 892       return Bcb->FileObject;
 893    }
 894    return NULL;
 895 }
 896
 897 VOID
 898 CcInitView(VOID)
 899 {
 900   DPRINT("CcInitView()\n");
 901   InitializeListHead(&CacheSegmentListHead);
 902   InitializeListHead(&DirtySegmentListHead);
 903   InitializeListHead(&CacheSegmentLRUListHead);
 904   ExInitializeFastMutex(&ViewLock);
 905   MmInitializeMemoryConsumer(MC_CACHE, CcRosTrimCache);
 906   CcInitCacheZeroPage();
 907 }
 908
 909 /* EOF */
 910
 911
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