reactos/ntoskrnl/cc/view.c
2021-02-19 15:48:31 +01:00

1503 lines
44 KiB
C

/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
* FILE: ntoskrnl/cc/view.c
* PURPOSE: Cache manager
*
* PROGRAMMERS: David Welch (welch@mcmail.com)
* Pierre Schweitzer (pierre@reactos.org)
*/
/* NOTES **********************************************************************
*
* This is not the NT implementation of a file cache nor anything much like
* it.
*
* The general procedure for a filesystem to implement a read or write
* dispatch routine is as follows
*
* (1) If caching for the FCB hasn't been initiated then so do by calling
* CcInitializeFileCache.
*
* (2) For each 4k region which is being read or written obtain a cache page
* by calling CcRequestCachePage.
*
* (3) If either the page is being read or not completely written, and it is
* not up to date then read its data from the underlying medium. If the read
* fails then call CcReleaseCachePage with VALID as FALSE and return a error.
*
* (4) Copy the data into or out of the page as necessary.
*
* (5) Release the cache page
*/
/* INCLUDES ******************************************************************/
#include <ntoskrnl.h>
#define NDEBUG
#include <debug.h>
/* GLOBALS *******************************************************************/
LIST_ENTRY DirtyVacbListHead;
static LIST_ENTRY VacbLruListHead;
NPAGED_LOOKASIDE_LIST iBcbLookasideList;
static NPAGED_LOOKASIDE_LIST SharedCacheMapLookasideList;
static NPAGED_LOOKASIDE_LIST VacbLookasideList;
/* Internal vars (MS):
* - Threshold above which lazy writer will start action
* - Amount of dirty pages
* - List for deferred writes
* - Spinlock when dealing with the deferred list
* - List for "clean" shared cache maps
*/
ULONG CcDirtyPageThreshold = 0;
ULONG CcTotalDirtyPages = 0;
LIST_ENTRY CcDeferredWrites;
KSPIN_LOCK CcDeferredWriteSpinLock;
LIST_ENTRY CcCleanSharedCacheMapList;
#if DBG
ULONG CcRosVacbIncRefCount_(PROS_VACB vacb, PCSTR file, INT line)
{
ULONG Refs;
Refs = InterlockedIncrement((PLONG)&vacb->ReferenceCount);
if (vacb->SharedCacheMap->Trace)
{
DbgPrint("(%s:%i) VACB %p ++RefCount=%lu, Dirty %u, PageOut %lu\n",
file, line, vacb, Refs, vacb->Dirty, vacb->PageOut);
}
return Refs;
}
ULONG CcRosVacbDecRefCount_(PROS_VACB vacb, PCSTR file, INT line)
{
ULONG Refs;
Refs = InterlockedDecrement((PLONG)&vacb->ReferenceCount);
ASSERT(!(Refs == 0 && vacb->Dirty));
if (vacb->SharedCacheMap->Trace)
{
DbgPrint("(%s:%i) VACB %p --RefCount=%lu, Dirty %u, PageOut %lu\n",
file, line, vacb, Refs, vacb->Dirty, vacb->PageOut);
}
if (Refs == 0)
{
CcRosInternalFreeVacb(vacb);
}
return Refs;
}
ULONG CcRosVacbGetRefCount_(PROS_VACB vacb, PCSTR file, INT line)
{
ULONG Refs;
Refs = InterlockedCompareExchange((PLONG)&vacb->ReferenceCount, 0, 0);
if (vacb->SharedCacheMap->Trace)
{
DbgPrint("(%s:%i) VACB %p ==RefCount=%lu, Dirty %u, PageOut %lu\n",
file, line, vacb, Refs, vacb->Dirty, vacb->PageOut);
}
return Refs;
}
#endif
/* FUNCTIONS *****************************************************************/
VOID
CcRosTraceCacheMap (
PROS_SHARED_CACHE_MAP SharedCacheMap,
BOOLEAN Trace )
{
#if DBG
KIRQL oldirql;
PLIST_ENTRY current_entry;
PROS_VACB current;
if (!SharedCacheMap)
return;
SharedCacheMap->Trace = Trace;
if (Trace)
{
DPRINT1("Enabling Tracing for CacheMap 0x%p:\n", SharedCacheMap);
oldirql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
current_entry = SharedCacheMap->CacheMapVacbListHead.Flink;
while (current_entry != &SharedCacheMap->CacheMapVacbListHead)
{
current = CONTAINING_RECORD(current_entry, ROS_VACB, CacheMapVacbListEntry);
current_entry = current_entry->Flink;
DPRINT1(" VACB 0x%p enabled, RefCount %lu, Dirty %u, PageOut %lu, BaseAddress %p, FileOffset %I64d\n",
current, current->ReferenceCount, current->Dirty, current->PageOut, current->BaseAddress, current->FileOffset.QuadPart);
}
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldirql);
}
else
{
DPRINT1("Disabling Tracing for CacheMap 0x%p:\n", SharedCacheMap);
}
#else
UNREFERENCED_PARAMETER(SharedCacheMap);
UNREFERENCED_PARAMETER(Trace);
#endif
}
NTSTATUS
CcRosFlushVacb (
_In_ PROS_VACB Vacb,
_In_ PIO_STATUS_BLOCK Iosb)
{
NTSTATUS Status;
BOOLEAN HaveLock = FALSE;
PROS_SHARED_CACHE_MAP SharedCacheMap = Vacb->SharedCacheMap;
CcRosUnmarkDirtyVacb(Vacb, TRUE);
/* Lock for flush, if we are not already the top-level */
if (IoGetTopLevelIrp() != (PIRP)FSRTL_CACHE_TOP_LEVEL_IRP)
{
Status = FsRtlAcquireFileForCcFlushEx(Vacb->SharedCacheMap->FileObject);
if (!NT_SUCCESS(Status))
goto quit;
HaveLock = TRUE;
}
Status = MmFlushSegment(SharedCacheMap->FileObject->SectionObjectPointer,
&Vacb->FileOffset,
VACB_MAPPING_GRANULARITY,
Iosb);
if (HaveLock)
{
FsRtlReleaseFileForCcFlush(Vacb->SharedCacheMap->FileObject);
}
quit:
if (!NT_SUCCESS(Status))
CcRosMarkDirtyVacb(Vacb);
else
{
/* Update VDL */
if (SharedCacheMap->ValidDataLength.QuadPart < (Vacb->FileOffset.QuadPart + VACB_MAPPING_GRANULARITY))
{
SharedCacheMap->ValidDataLength.QuadPart = Vacb->FileOffset.QuadPart + VACB_MAPPING_GRANULARITY;
}
}
return Status;
}
static
NTSTATUS
CcRosDeleteFileCache (
PFILE_OBJECT FileObject,
PROS_SHARED_CACHE_MAP SharedCacheMap,
PKIRQL OldIrql)
/*
* FUNCTION: Releases the shared cache map associated with a file object
*/
{
PLIST_ENTRY current_entry;
ASSERT(SharedCacheMap);
ASSERT(SharedCacheMap == FileObject->SectionObjectPointer->SharedCacheMap);
ASSERT(SharedCacheMap->OpenCount == 0);
/* Remove all VACBs from the global lists */
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
current_entry = SharedCacheMap->CacheMapVacbListHead.Flink;
while (current_entry != &SharedCacheMap->CacheMapVacbListHead)
{
PROS_VACB Vacb = CONTAINING_RECORD(current_entry, ROS_VACB, CacheMapVacbListEntry);
RemoveEntryList(&Vacb->VacbLruListEntry);
InitializeListHead(&Vacb->VacbLruListEntry);
if (Vacb->Dirty)
{
CcRosUnmarkDirtyVacb(Vacb, FALSE);
/* Mark it as dirty again so we know that we have to flush before freeing it */
Vacb->Dirty = TRUE;
}
current_entry = current_entry->Flink;
}
/* Make sure there is no trace anymore of this map */
FileObject->SectionObjectPointer->SharedCacheMap = NULL;
RemoveEntryList(&SharedCacheMap->SharedCacheMapLinks);
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
KeReleaseQueuedSpinLock(LockQueueMasterLock, *OldIrql);
/* Now that we're out of the locks, free everything for real */
while (!IsListEmpty(&SharedCacheMap->CacheMapVacbListHead))
{
PROS_VACB Vacb = CONTAINING_RECORD(RemoveHeadList(&SharedCacheMap->CacheMapVacbListHead), ROS_VACB, CacheMapVacbListEntry);
ULONG RefCount;
InitializeListHead(&Vacb->CacheMapVacbListEntry);
/* Flush to disk, if needed */
if (Vacb->Dirty)
{
IO_STATUS_BLOCK Iosb;
NTSTATUS Status;
Status = MmFlushSegment(FileObject->SectionObjectPointer, &Vacb->FileOffset, VACB_MAPPING_GRANULARITY, &Iosb);
if (!NT_SUCCESS(Status))
{
/* Complain. There's not much we can do */
DPRINT1("Failed to flush VACB to disk while deleting the cache entry. Status: 0x%08x\n", Status);
}
Vacb->Dirty = FALSE;
}
RefCount = CcRosVacbDecRefCount(Vacb);
#if DBG // CORE-14578
if (RefCount != 0)
{
DPRINT1("Leaking VACB %p attached to %p (%I64d)\n", Vacb, FileObject, Vacb->FileOffset.QuadPart);
DPRINT1("There are: %d references left\n", RefCount);
DPRINT1("Map: %d\n", Vacb->MappedCount);
DPRINT1("Dirty: %d\n", Vacb->Dirty);
if (FileObject->FileName.Length != 0)
{
DPRINT1("File was: %wZ\n", &FileObject->FileName);
}
else
{
DPRINT1("No name for the file\n");
}
}
#else
(void)RefCount;
#endif
}
/* Release the references we own */
if(SharedCacheMap->Section)
ObDereferenceObject(SharedCacheMap->Section);
ObDereferenceObject(SharedCacheMap->FileObject);
ExFreeToNPagedLookasideList(&SharedCacheMapLookasideList, SharedCacheMap);
/* Acquire the lock again for our caller */
*OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
return STATUS_SUCCESS;
}
NTSTATUS
CcRosFlushDirtyPages (
ULONG Target,
PULONG Count,
BOOLEAN Wait,
BOOLEAN CalledFromLazy)
{
PLIST_ENTRY current_entry;
NTSTATUS Status;
KIRQL OldIrql;
BOOLEAN FlushAll = (Target == MAXULONG);
DPRINT("CcRosFlushDirtyPages(Target %lu)\n", Target);
(*Count) = 0;
KeEnterCriticalRegion();
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
current_entry = DirtyVacbListHead.Flink;
if (current_entry == &DirtyVacbListHead)
{
DPRINT("No Dirty pages\n");
}
while (((current_entry != &DirtyVacbListHead) && (Target > 0)) || FlushAll)
{
PROS_SHARED_CACHE_MAP SharedCacheMap;
PROS_VACB current;
BOOLEAN Locked;
if (current_entry == &DirtyVacbListHead)
{
ASSERT(FlushAll);
if (IsListEmpty(&DirtyVacbListHead))
break;
current_entry = DirtyVacbListHead.Flink;
}
current = CONTAINING_RECORD(current_entry,
ROS_VACB,
DirtyVacbListEntry);
current_entry = current_entry->Flink;
CcRosVacbIncRefCount(current);
SharedCacheMap = current->SharedCacheMap;
/* When performing lazy write, don't handle temporary files */
if (CalledFromLazy && BooleanFlagOn(SharedCacheMap->FileObject->Flags, FO_TEMPORARY_FILE))
{
CcRosVacbDecRefCount(current);
continue;
}
/* Don't attempt to lazy write the files that asked not to */
if (CalledFromLazy && BooleanFlagOn(SharedCacheMap->Flags, WRITEBEHIND_DISABLED))
{
CcRosVacbDecRefCount(current);
continue;
}
ASSERT(current->Dirty);
/* Do not lazy-write the same file concurrently. Fastfat ASSERTS on that */
if (SharedCacheMap->Flags & SHARED_CACHE_MAP_IN_LAZYWRITE)
{
CcRosVacbDecRefCount(current);
continue;
}
SharedCacheMap->Flags |= SHARED_CACHE_MAP_IN_LAZYWRITE;
/* Keep a ref on the shared cache map */
SharedCacheMap->OpenCount++;
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
Locked = SharedCacheMap->Callbacks->AcquireForLazyWrite(SharedCacheMap->LazyWriteContext, Wait);
if (!Locked)
{
DPRINT("Not locked!");
ASSERT(!Wait);
CcRosVacbDecRefCount(current);
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
SharedCacheMap->Flags &= ~SHARED_CACHE_MAP_IN_LAZYWRITE;
if (--SharedCacheMap->OpenCount == 0)
CcRosDeleteFileCache(SharedCacheMap->FileObject, SharedCacheMap, &OldIrql);
continue;
}
IO_STATUS_BLOCK Iosb;
Status = CcRosFlushVacb(current, &Iosb);
SharedCacheMap->Callbacks->ReleaseFromLazyWrite(SharedCacheMap->LazyWriteContext);
/* We release the VACB before acquiring the lock again, because
* CcRosVacbDecRefCount might free the VACB, as CcRosFlushVacb dropped a
* Refcount. Freeing must be done outside of the lock.
* The refcount is decremented atomically. So this is OK. */
CcRosVacbDecRefCount(current);
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
SharedCacheMap->Flags &= ~SHARED_CACHE_MAP_IN_LAZYWRITE;
if (--SharedCacheMap->OpenCount == 0)
CcRosDeleteFileCache(SharedCacheMap->FileObject, SharedCacheMap, &OldIrql);
if (!NT_SUCCESS(Status) && (Status != STATUS_END_OF_FILE) &&
(Status != STATUS_MEDIA_WRITE_PROTECTED))
{
DPRINT1("CC: Failed to flush VACB.\n");
}
else
{
ULONG PagesFreed;
/* How many pages did we free? */
PagesFreed = Iosb.Information / PAGE_SIZE;
(*Count) += PagesFreed;
if (!Wait)
{
/* Make sure we don't overflow target! */
if (Target < PagesFreed)
{
/* If we would have, jump to zero directly */
Target = 0;
}
else
{
Target -= PagesFreed;
}
}
}
current_entry = DirtyVacbListHead.Flink;
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
KeLeaveCriticalRegion();
DPRINT("CcRosFlushDirtyPages() finished\n");
return STATUS_SUCCESS;
}
NTSTATUS
CcRosReleaseVacb (
PROS_SHARED_CACHE_MAP SharedCacheMap,
PROS_VACB Vacb,
BOOLEAN Dirty,
BOOLEAN Mapped)
{
ULONG Refs;
ASSERT(SharedCacheMap);
DPRINT("CcRosReleaseVacb(SharedCacheMap 0x%p, Vacb 0x%p)\n", SharedCacheMap, Vacb);
if (Dirty && !Vacb->Dirty)
{
CcRosMarkDirtyVacb(Vacb);
}
if (Mapped)
{
if (InterlockedIncrement((PLONG)&Vacb->MappedCount) == 1)
{
CcRosVacbIncRefCount(Vacb);
}
}
Refs = CcRosVacbDecRefCount(Vacb);
ASSERT(Refs > 0);
return STATUS_SUCCESS;
}
/* Returns with VACB Lock Held! */
PROS_VACB
CcRosLookupVacb (
PROS_SHARED_CACHE_MAP SharedCacheMap,
LONGLONG FileOffset)
{
PLIST_ENTRY current_entry;
PROS_VACB current;
KIRQL oldIrql;
ASSERT(SharedCacheMap);
DPRINT("CcRosLookupVacb(SharedCacheMap 0x%p, FileOffset %I64u)\n",
SharedCacheMap, FileOffset);
oldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
current_entry = SharedCacheMap->CacheMapVacbListHead.Flink;
while (current_entry != &SharedCacheMap->CacheMapVacbListHead)
{
current = CONTAINING_RECORD(current_entry,
ROS_VACB,
CacheMapVacbListEntry);
if (IsPointInRange(current->FileOffset.QuadPart,
VACB_MAPPING_GRANULARITY,
FileOffset))
{
CcRosVacbIncRefCount(current);
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
return current;
}
if (current->FileOffset.QuadPart > FileOffset)
break;
current_entry = current_entry->Flink;
}
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
return NULL;
}
VOID
CcRosMarkDirtyVacb (
PROS_VACB Vacb)
{
KIRQL oldIrql;
PROS_SHARED_CACHE_MAP SharedCacheMap;
SharedCacheMap = Vacb->SharedCacheMap;
oldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
ASSERT(!Vacb->Dirty);
InsertTailList(&DirtyVacbListHead, &Vacb->DirtyVacbListEntry);
/* FIXME: There is no reason to account for the whole VACB. */
CcTotalDirtyPages += VACB_MAPPING_GRANULARITY / PAGE_SIZE;
Vacb->SharedCacheMap->DirtyPages += VACB_MAPPING_GRANULARITY / PAGE_SIZE;
CcRosVacbIncRefCount(Vacb);
/* Move to the tail of the LRU list */
RemoveEntryList(&Vacb->VacbLruListEntry);
InsertTailList(&VacbLruListHead, &Vacb->VacbLruListEntry);
Vacb->Dirty = TRUE;
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
/* Schedule a lazy writer run to now that we have dirty VACB */
if (!LazyWriter.ScanActive)
{
CcScheduleLazyWriteScan(FALSE);
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
}
VOID
CcRosUnmarkDirtyVacb (
PROS_VACB Vacb,
BOOLEAN LockViews)
{
KIRQL oldIrql;
PROS_SHARED_CACHE_MAP SharedCacheMap;
SharedCacheMap = Vacb->SharedCacheMap;
if (LockViews)
{
oldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
}
ASSERT(Vacb->Dirty);
Vacb->Dirty = FALSE;
RemoveEntryList(&Vacb->DirtyVacbListEntry);
InitializeListHead(&Vacb->DirtyVacbListEntry);
CcTotalDirtyPages -= VACB_MAPPING_GRANULARITY / PAGE_SIZE;
Vacb->SharedCacheMap->DirtyPages -= VACB_MAPPING_GRANULARITY / PAGE_SIZE;
CcRosVacbDecRefCount(Vacb);
if (LockViews)
{
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
}
}
static
BOOLEAN
CcRosFreeUnusedVacb (
PULONG Count)
{
ULONG cFreed;
BOOLEAN Freed;
KIRQL oldIrql;
PROS_VACB current;
LIST_ENTRY FreeList;
PLIST_ENTRY current_entry;
cFreed = 0;
Freed = FALSE;
InitializeListHead(&FreeList);
oldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
/* Browse all the available VACB */
current_entry = VacbLruListHead.Flink;
while (current_entry != &VacbLruListHead)
{
ULONG Refs;
current = CONTAINING_RECORD(current_entry,
ROS_VACB,
VacbLruListEntry);
current_entry = current_entry->Flink;
KeAcquireSpinLockAtDpcLevel(&current->SharedCacheMap->CacheMapLock);
/* Only deal with unused VACB, we will free them */
Refs = CcRosVacbGetRefCount(current);
if (Refs < 2)
{
ASSERT(!current->Dirty);
ASSERT(!current->MappedCount);
ASSERT(Refs == 1);
/* Reset and move to free list */
RemoveEntryList(&current->CacheMapVacbListEntry);
RemoveEntryList(&current->VacbLruListEntry);
InitializeListHead(&current->VacbLruListEntry);
InsertHeadList(&FreeList, &current->CacheMapVacbListEntry);
}
KeReleaseSpinLockFromDpcLevel(&current->SharedCacheMap->CacheMapLock);
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
/* And now, free any of the found VACB, that'll free memory! */
while (!IsListEmpty(&FreeList))
{
ULONG Refs;
current_entry = RemoveHeadList(&FreeList);
current = CONTAINING_RECORD(current_entry,
ROS_VACB,
CacheMapVacbListEntry);
InitializeListHead(&current->CacheMapVacbListEntry);
Refs = CcRosVacbDecRefCount(current);
ASSERT(Refs == 0);
++cFreed;
}
/* If we freed at least one VACB, return success */
if (cFreed != 0)
{
Freed = TRUE;
}
/* If caller asked for free count, return it */
if (Count != NULL)
{
*Count = cFreed;
}
return Freed;
}
static
NTSTATUS
CcRosCreateVacb (
PROS_SHARED_CACHE_MAP SharedCacheMap,
LONGLONG FileOffset,
PROS_VACB *Vacb)
{
PROS_VACB current;
PROS_VACB previous;
PLIST_ENTRY current_entry;
NTSTATUS Status;
KIRQL oldIrql;
ULONG Refs;
BOOLEAN Retried;
SIZE_T ViewSize = VACB_MAPPING_GRANULARITY;
ASSERT(SharedCacheMap);
DPRINT("CcRosCreateVacb()\n");
current = ExAllocateFromNPagedLookasideList(&VacbLookasideList);
current->BaseAddress = NULL;
current->Dirty = FALSE;
current->PageOut = FALSE;
current->FileOffset.QuadPart = ROUND_DOWN(FileOffset, VACB_MAPPING_GRANULARITY);
current->SharedCacheMap = SharedCacheMap;
current->MappedCount = 0;
current->ReferenceCount = 0;
InitializeListHead(&current->CacheMapVacbListEntry);
InitializeListHead(&current->DirtyVacbListEntry);
InitializeListHead(&current->VacbLruListEntry);
CcRosVacbIncRefCount(current);
Retried = FALSE;
Retry:
/* Map VACB in system space */
Status = MmMapViewInSystemSpaceEx(SharedCacheMap->Section, &current->BaseAddress, &ViewSize, &current->FileOffset, 0);
if (!NT_SUCCESS(Status))
{
ULONG Freed;
/* If no space left, try to prune unused VACB
* to recover space to map our VACB
* If it succeed, retry to map, otherwise
* just fail.
*/
if (!Retried && CcRosFreeUnusedVacb(&Freed))
{
DPRINT("Prunned %d VACB, trying again\n", Freed);
Retried = TRUE;
goto Retry;
}
ExFreeToNPagedLookasideList(&VacbLookasideList, current);
return Status;
}
#if DBG
if (SharedCacheMap->Trace)
{
DPRINT1("CacheMap 0x%p: new VACB: 0x%p, file offset %I64d, BaseAddress %p\n",
SharedCacheMap, current, current->FileOffset.QuadPart, current->BaseAddress);
}
#endif
oldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
*Vacb = current;
/* There is window between the call to CcRosLookupVacb
* and CcRosCreateVacb. We must check if a VACB for the
* file offset exist. If there is a VACB, we release
* our newly created VACB and return the existing one.
*/
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
current_entry = SharedCacheMap->CacheMapVacbListHead.Flink;
previous = NULL;
while (current_entry != &SharedCacheMap->CacheMapVacbListHead)
{
current = CONTAINING_RECORD(current_entry,
ROS_VACB,
CacheMapVacbListEntry);
if (IsPointInRange(current->FileOffset.QuadPart,
VACB_MAPPING_GRANULARITY,
FileOffset))
{
CcRosVacbIncRefCount(current);
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
#if DBG
if (SharedCacheMap->Trace)
{
DPRINT1("CacheMap 0x%p: deleting newly created VACB 0x%p ( found existing one 0x%p )\n",
SharedCacheMap,
(*Vacb),
current);
}
#endif
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
Refs = CcRosVacbDecRefCount(*Vacb);
ASSERT(Refs == 0);
*Vacb = current;
return STATUS_SUCCESS;
}
if (current->FileOffset.QuadPart < FileOffset)
{
ASSERT(previous == NULL ||
previous->FileOffset.QuadPart < current->FileOffset.QuadPart);
previous = current;
}
if (current->FileOffset.QuadPart > FileOffset)
break;
current_entry = current_entry->Flink;
}
/* There was no existing VACB. */
current = *Vacb;
if (previous)
{
InsertHeadList(&previous->CacheMapVacbListEntry, &current->CacheMapVacbListEntry);
}
else
{
InsertHeadList(&SharedCacheMap->CacheMapVacbListHead, &current->CacheMapVacbListEntry);
}
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
InsertTailList(&VacbLruListHead, &current->VacbLruListEntry);
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
MI_SET_USAGE(MI_USAGE_CACHE);
#if MI_TRACE_PFNS
if ((SharedCacheMap->FileObject) && (SharedCacheMap->FileObject->FileName.Buffer))
{
PWCHAR pos;
ULONG len = 0;
pos = wcsrchr(SharedCacheMap->FileObject->FileName.Buffer, '\\');
if (pos)
{
len = wcslen(pos) * sizeof(WCHAR);
snprintf(MI_PFN_CURRENT_PROCESS_NAME, min(16, len), "%S", pos);
}
else
{
snprintf(MI_PFN_CURRENT_PROCESS_NAME, min(16, len), "%wZ", &SharedCacheMap->FileObject->FileName);
}
}
#endif
/* Reference it to allow release */
CcRosVacbIncRefCount(current);
return Status;
}
BOOLEAN
CcRosEnsureVacbResident(
_In_ PROS_VACB Vacb,
_In_ BOOLEAN Wait,
_In_ BOOLEAN NoRead,
_In_ ULONG Offset,
_In_ ULONG Length
)
{
PVOID BaseAddress;
ASSERT((Offset + Length) <= VACB_MAPPING_GRANULARITY);
#if 0
if ((Vacb->FileOffset.QuadPart + Offset) > Vacb->SharedCacheMap->SectionSize.QuadPart)
{
DPRINT1("Vacb read beyond the file size!\n");
return FALSE;
}
#endif
BaseAddress = (PVOID)((ULONG_PTR)Vacb->BaseAddress + Offset);
/* Check if the pages are resident */
if (!MmArePagesResident(NULL, BaseAddress, Length))
{
if (!Wait)
{
return FALSE;
}
if (!NoRead)
{
PROS_SHARED_CACHE_MAP SharedCacheMap = Vacb->SharedCacheMap;
NTSTATUS Status = MmMakeDataSectionResident(SharedCacheMap->FileObject->SectionObjectPointer,
Vacb->FileOffset.QuadPart + Offset,
Length,
&SharedCacheMap->ValidDataLength);
if (!NT_SUCCESS(Status))
ExRaiseStatus(Status);
}
}
return TRUE;
}
NTSTATUS
CcRosGetVacb (
PROS_SHARED_CACHE_MAP SharedCacheMap,
LONGLONG FileOffset,
PROS_VACB *Vacb)
{
PROS_VACB current;
NTSTATUS Status;
ULONG Refs;
KIRQL OldIrql;
ASSERT(SharedCacheMap);
DPRINT("CcRosGetVacb()\n");
/*
* Look for a VACB already mapping the same data.
*/
current = CcRosLookupVacb(SharedCacheMap, FileOffset);
if (current == NULL)
{
/*
* Otherwise create a new VACB.
*/
Status = CcRosCreateVacb(SharedCacheMap, FileOffset, &current);
if (!NT_SUCCESS(Status))
{
return Status;
}
}
Refs = CcRosVacbGetRefCount(current);
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
/* Move to the tail of the LRU list */
RemoveEntryList(&current->VacbLruListEntry);
InsertTailList(&VacbLruListHead, &current->VacbLruListEntry);
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
/*
* Return the VACB to the caller.
*/
*Vacb = current;
ASSERT(Refs > 1);
return STATUS_SUCCESS;
}
NTSTATUS
CcRosRequestVacb (
PROS_SHARED_CACHE_MAP SharedCacheMap,
LONGLONG FileOffset,
PROS_VACB *Vacb)
/*
* FUNCTION: Request a page mapping for a shared cache map
*/
{
ASSERT(SharedCacheMap);
if (FileOffset % VACB_MAPPING_GRANULARITY != 0)
{
DPRINT1("Bad fileoffset %I64x should be multiple of %x",
FileOffset, VACB_MAPPING_GRANULARITY);
KeBugCheck(CACHE_MANAGER);
}
return CcRosGetVacb(SharedCacheMap,
FileOffset,
Vacb);
}
NTSTATUS
CcRosInternalFreeVacb (
PROS_VACB Vacb)
/*
* FUNCTION: Releases a VACB associated with a shared cache map
*/
{
NTSTATUS Status;
DPRINT("Freeing VACB 0x%p\n", Vacb);
#if DBG
if (Vacb->SharedCacheMap->Trace)
{
DPRINT1("CacheMap 0x%p: deleting VACB: 0x%p\n", Vacb->SharedCacheMap, Vacb);
}
#endif
if (Vacb->ReferenceCount != 0)
{
DPRINT1("Invalid free: %ld\n", Vacb->ReferenceCount);
if (Vacb->SharedCacheMap->FileObject && Vacb->SharedCacheMap->FileObject->FileName.Length)
{
DPRINT1("For file: %wZ\n", &Vacb->SharedCacheMap->FileObject->FileName);
}
}
ASSERT(Vacb->ReferenceCount == 0);
ASSERT(IsListEmpty(&Vacb->CacheMapVacbListEntry));
ASSERT(IsListEmpty(&Vacb->DirtyVacbListEntry));
ASSERT(IsListEmpty(&Vacb->VacbLruListEntry));
/* Delete the mapping */
Status = MmUnmapViewInSystemSpace(Vacb->BaseAddress);
if (!NT_SUCCESS(Status))
{
DPRINT1("Failed to unmap VACB from System address space! Status 0x%08X\n", Status);
ASSERT(FALSE);
/* Proceed with the deĺetion anyway */
}
RtlFillMemory(Vacb, sizeof(*Vacb), 0xfd);
ExFreeToNPagedLookasideList(&VacbLookasideList, Vacb);
return STATUS_SUCCESS;
}
/*
* @implemented
*/
VOID
NTAPI
CcFlushCache (
IN PSECTION_OBJECT_POINTERS SectionObjectPointers,
IN PLARGE_INTEGER FileOffset OPTIONAL,
IN ULONG Length,
OUT PIO_STATUS_BLOCK IoStatus)
{
PROS_SHARED_CACHE_MAP SharedCacheMap;
LONGLONG FlushStart, FlushEnd;
NTSTATUS Status;
CCTRACE(CC_API_DEBUG, "SectionObjectPointers=%p FileOffset=0x%I64X Length=%lu\n",
SectionObjectPointers, FileOffset ? FileOffset->QuadPart : 0LL, Length);
if (!SectionObjectPointers)
{
Status = STATUS_INVALID_PARAMETER;
goto quit;
}
if (!SectionObjectPointers->SharedCacheMap)
{
/* Forward this to Mm */
MmFlushSegment(SectionObjectPointers, FileOffset, Length, IoStatus);
return;
}
SharedCacheMap = SectionObjectPointers->SharedCacheMap;
ASSERT(SharedCacheMap);
if (FileOffset)
{
FlushStart = FileOffset->QuadPart;
Status = RtlLongLongAdd(FlushStart, Length, &FlushEnd);
if (!NT_SUCCESS(Status))
goto quit;
}
else
{
FlushStart = 0;
FlushEnd = SharedCacheMap->FileSize.QuadPart;
}
Status = STATUS_SUCCESS;
if (IoStatus)
{
IoStatus->Information = 0;
}
/*
* We flush the VACBs that we find here.
* If there is no (dirty) VACB, it doesn't mean that there is no data to flush, so we call Mm to be sure.
* This is suboptimal, but this is due to the lack of granularity of how we track dirty cache data
*/
while (FlushStart < FlushEnd)
{
BOOLEAN DirtyVacb = FALSE;
PROS_VACB vacb = CcRosLookupVacb(SharedCacheMap, FlushStart);
if (vacb != NULL)
{
if (vacb->Dirty)
{
IO_STATUS_BLOCK VacbIosb;
Status = CcRosFlushVacb(vacb, &VacbIosb);
if (!NT_SUCCESS(Status))
{
goto quit;
}
DirtyVacb = TRUE;
if (IoStatus)
IoStatus->Information += VacbIosb.Information;
}
CcRosReleaseVacb(SharedCacheMap, vacb, FALSE, FALSE);
}
if (!DirtyVacb)
{
IO_STATUS_BLOCK MmIosb;
LARGE_INTEGER MmOffset;
MmOffset.QuadPart = FlushStart;
if (FlushEnd - (FlushEnd % VACB_MAPPING_GRANULARITY) <= FlushStart)
{
/* The whole range fits within a VACB chunk. */
Status = MmFlushSegment(SectionObjectPointers, &MmOffset, FlushEnd - FlushStart, &MmIosb);
}
else
{
ULONG MmLength = VACB_MAPPING_GRANULARITY - (FlushStart % VACB_MAPPING_GRANULARITY);
Status = MmFlushSegment(SectionObjectPointers, &MmOffset, MmLength, &MmIosb);
}
if (!NT_SUCCESS(Status))
goto quit;
if (IoStatus)
IoStatus->Information += MmIosb.Information;
/* Update VDL */
if (SharedCacheMap->ValidDataLength.QuadPart < FlushEnd)
SharedCacheMap->ValidDataLength.QuadPart = FlushEnd;
}
if (!NT_SUCCESS(RtlLongLongAdd(FlushStart, VACB_MAPPING_GRANULARITY, &FlushStart)))
{
/* We're at the end of file ! */
break;
}
/* Round down to next VACB start now */
FlushStart -= FlushStart % VACB_MAPPING_GRANULARITY;
}
quit:
if (IoStatus)
{
IoStatus->Status = Status;
}
}
NTSTATUS
CcRosReleaseFileCache (
PFILE_OBJECT FileObject)
/*
* FUNCTION: Called by the file system when a handle to a file object
* has been closed.
*/
{
KIRQL OldIrql;
PPRIVATE_CACHE_MAP PrivateMap;
PROS_SHARED_CACHE_MAP SharedCacheMap;
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
if (FileObject->SectionObjectPointer->SharedCacheMap != NULL)
{
SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
/* Closing the handle, so kill the private cache map
* Before you event try to remove it from FO, always
* lock the master lock, to be sure not to race
* with a potential read ahead ongoing!
*/
PrivateMap = FileObject->PrivateCacheMap;
FileObject->PrivateCacheMap = NULL;
if (PrivateMap != NULL)
{
/* Remove it from the file */
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
RemoveEntryList(&PrivateMap->PrivateLinks);
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
/* And free it. */
if (PrivateMap != &SharedCacheMap->PrivateCacheMap)
{
ExFreePoolWithTag(PrivateMap, TAG_PRIVATE_CACHE_MAP);
}
else
{
PrivateMap->NodeTypeCode = 0;
}
ASSERT(SharedCacheMap->OpenCount > 0);
SharedCacheMap->OpenCount--;
if (SharedCacheMap->OpenCount == 0)
{
CcRosDeleteFileCache(FileObject, SharedCacheMap, &OldIrql);
}
}
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
return STATUS_SUCCESS;
}
NTSTATUS
CcRosInitializeFileCache (
PFILE_OBJECT FileObject,
PCC_FILE_SIZES FileSizes,
BOOLEAN PinAccess,
PCACHE_MANAGER_CALLBACKS CallBacks,
PVOID LazyWriterContext)
/*
* FUNCTION: Initializes a shared cache map for a file object
*/
{
KIRQL OldIrql;
BOOLEAN Allocated;
PROS_SHARED_CACHE_MAP SharedCacheMap;
DPRINT("CcRosInitializeFileCache(FileObject 0x%p)\n", FileObject);
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
Allocated = FALSE;
SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
if (SharedCacheMap == NULL)
{
Allocated = TRUE;
SharedCacheMap = ExAllocateFromNPagedLookasideList(&SharedCacheMapLookasideList);
if (SharedCacheMap == NULL)
{
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(SharedCacheMap, sizeof(*SharedCacheMap));
SharedCacheMap->NodeTypeCode = NODE_TYPE_SHARED_MAP;
SharedCacheMap->NodeByteSize = sizeof(*SharedCacheMap);
SharedCacheMap->FileObject = FileObject;
SharedCacheMap->Callbacks = CallBacks;
SharedCacheMap->LazyWriteContext = LazyWriterContext;
SharedCacheMap->SectionSize = FileSizes->AllocationSize;
SharedCacheMap->FileSize = FileSizes->FileSize;
SharedCacheMap->ValidDataLength = FileSizes->ValidDataLength;
SharedCacheMap->PinAccess = PinAccess;
SharedCacheMap->DirtyPageThreshold = 0;
SharedCacheMap->DirtyPages = 0;
InitializeListHead(&SharedCacheMap->PrivateList);
KeInitializeSpinLock(&SharedCacheMap->CacheMapLock);
InitializeListHead(&SharedCacheMap->CacheMapVacbListHead);
InitializeListHead(&SharedCacheMap->BcbList);
SharedCacheMap->Flags = SHARED_CACHE_MAP_IN_CREATION;
ObReferenceObjectByPointer(FileObject,
FILE_ALL_ACCESS,
NULL,
KernelMode);
FileObject->SectionObjectPointer->SharedCacheMap = SharedCacheMap;
//CcRosTraceCacheMap(SharedCacheMap, TRUE);
}
else if (SharedCacheMap->Flags & SHARED_CACHE_MAP_IN_CREATION)
{
/* The shared cache map is being created somewhere else. Wait for that to happen */
KEVENT Waiter;
PKEVENT PreviousWaiter = SharedCacheMap->CreateEvent;
KeInitializeEvent(&Waiter, NotificationEvent, FALSE);
SharedCacheMap->CreateEvent = &Waiter;
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
KeWaitForSingleObject(&Waiter, Executive, KernelMode, FALSE, NULL);
if (PreviousWaiter)
KeSetEvent(PreviousWaiter, IO_NO_INCREMENT, FALSE);
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
}
if (FileObject->PrivateCacheMap == NULL)
{
PPRIVATE_CACHE_MAP PrivateMap;
/* Allocate the private cache map for this handle */
if (SharedCacheMap->PrivateCacheMap.NodeTypeCode != 0)
{
PrivateMap = ExAllocatePoolWithTag(NonPagedPool, sizeof(PRIVATE_CACHE_MAP), TAG_PRIVATE_CACHE_MAP);
}
else
{
PrivateMap = &SharedCacheMap->PrivateCacheMap;
}
if (PrivateMap == NULL)
{
/* If we also allocated the shared cache map for this file, kill it */
if (Allocated)
{
RemoveEntryList(&SharedCacheMap->SharedCacheMapLinks);
FileObject->SectionObjectPointer->SharedCacheMap = NULL;
ObDereferenceObject(FileObject);
ExFreeToNPagedLookasideList(&SharedCacheMapLookasideList, SharedCacheMap);
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
return STATUS_INSUFFICIENT_RESOURCES;
}
/* Initialize it */
RtlZeroMemory(PrivateMap, sizeof(PRIVATE_CACHE_MAP));
PrivateMap->NodeTypeCode = NODE_TYPE_PRIVATE_MAP;
PrivateMap->ReadAheadMask = PAGE_SIZE - 1;
PrivateMap->FileObject = FileObject;
KeInitializeSpinLock(&PrivateMap->ReadAheadSpinLock);
/* Link it to the file */
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
InsertTailList(&SharedCacheMap->PrivateList, &PrivateMap->PrivateLinks);
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
FileObject->PrivateCacheMap = PrivateMap;
SharedCacheMap->OpenCount++;
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
/* Create the section */
if (Allocated)
{
NTSTATUS Status;
ASSERT(SharedCacheMap->Section == NULL);
Status = MmCreateSection(
&SharedCacheMap->Section,
SECTION_ALL_ACCESS,
NULL,
&SharedCacheMap->SectionSize,
PAGE_READWRITE,
SEC_RESERVE,
NULL,
FileObject);
ASSERT(NT_SUCCESS(Status));
if (!NT_SUCCESS(Status))
{
CcRosReleaseFileCache(FileObject);
return Status;
}
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
InsertTailList(&CcCleanSharedCacheMapList, &SharedCacheMap->SharedCacheMapLinks);
SharedCacheMap->Flags &= ~SHARED_CACHE_MAP_IN_CREATION;
if (SharedCacheMap->CreateEvent)
{
KeSetEvent(SharedCacheMap->CreateEvent, IO_NO_INCREMENT, FALSE);
SharedCacheMap->CreateEvent = NULL;
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
}
return STATUS_SUCCESS;
}
/*
* @implemented
*/
PFILE_OBJECT
NTAPI
CcGetFileObjectFromSectionPtrs (
IN PSECTION_OBJECT_POINTERS SectionObjectPointers)
{
PROS_SHARED_CACHE_MAP SharedCacheMap;
CCTRACE(CC_API_DEBUG, "SectionObjectPointers=%p\n", SectionObjectPointers);
if (SectionObjectPointers && SectionObjectPointers->SharedCacheMap)
{
SharedCacheMap = SectionObjectPointers->SharedCacheMap;
ASSERT(SharedCacheMap);
return SharedCacheMap->FileObject;
}
return NULL;
}
CODE_SEG("INIT")
VOID
NTAPI
CcInitView (
VOID)
{
DPRINT("CcInitView()\n");
InitializeListHead(&DirtyVacbListHead);
InitializeListHead(&VacbLruListHead);
InitializeListHead(&CcDeferredWrites);
InitializeListHead(&CcCleanSharedCacheMapList);
KeInitializeSpinLock(&CcDeferredWriteSpinLock);
ExInitializeNPagedLookasideList(&iBcbLookasideList,
NULL,
NULL,
0,
sizeof(INTERNAL_BCB),
TAG_BCB,
20);
ExInitializeNPagedLookasideList(&SharedCacheMapLookasideList,
NULL,
NULL,
0,
sizeof(ROS_SHARED_CACHE_MAP),
TAG_SHARED_CACHE_MAP,
20);
ExInitializeNPagedLookasideList(&VacbLookasideList,
NULL,
NULL,
0,
sizeof(ROS_VACB),
TAG_VACB,
20);
CcInitCacheZeroPage();
}
#if DBG && defined(KDBG)
BOOLEAN
ExpKdbgExtFileCache(ULONG Argc, PCHAR Argv[])
{
PLIST_ENTRY ListEntry;
UNICODE_STRING NoName = RTL_CONSTANT_STRING(L"No name for File");
KdbpPrint(" Usage Summary (in kb)\n");
KdbpPrint("Shared\t\tMapped\tDirty\tName\n");
/* No need to lock the spin lock here, we're in DBG */
for (ListEntry = CcCleanSharedCacheMapList.Flink;
ListEntry != &CcCleanSharedCacheMapList;
ListEntry = ListEntry->Flink)
{
PLIST_ENTRY Vacbs;
ULONG Mapped = 0, Dirty = 0;
PROS_SHARED_CACHE_MAP SharedCacheMap;
PUNICODE_STRING FileName;
PWSTR Extra = L"";
SharedCacheMap = CONTAINING_RECORD(ListEntry, ROS_SHARED_CACHE_MAP, SharedCacheMapLinks);
/* Dirty size */
Dirty = (SharedCacheMap->DirtyPages * PAGE_SIZE) / 1024;
/* First, count for all the associated VACB */
for (Vacbs = SharedCacheMap->CacheMapVacbListHead.Flink;
Vacbs != &SharedCacheMap->CacheMapVacbListHead;
Vacbs = Vacbs->Flink)
{
Mapped += VACB_MAPPING_GRANULARITY / 1024;
}
/* Setup name */
if (SharedCacheMap->FileObject != NULL &&
SharedCacheMap->FileObject->FileName.Length != 0)
{
FileName = &SharedCacheMap->FileObject->FileName;
}
else if (SharedCacheMap->FileObject != NULL &&
SharedCacheMap->FileObject->FsContext != NULL &&
((PFSRTL_COMMON_FCB_HEADER)(SharedCacheMap->FileObject->FsContext))->NodeTypeCode == 0x0502 &&
((PFSRTL_COMMON_FCB_HEADER)(SharedCacheMap->FileObject->FsContext))->NodeByteSize == 0x1F8 &&
((PUNICODE_STRING)(((PUCHAR)SharedCacheMap->FileObject->FsContext) + 0x100))->Length != 0)
{
FileName = (PUNICODE_STRING)(((PUCHAR)SharedCacheMap->FileObject->FsContext) + 0x100);
Extra = L" (FastFAT)";
}
else
{
FileName = &NoName;
}
/* And print */
KdbpPrint("%p\t%d\t%d\t%wZ%S\n", SharedCacheMap, Mapped, Dirty, FileName, Extra);
}
return TRUE;
}
BOOLEAN
ExpKdbgExtDefWrites(ULONG Argc, PCHAR Argv[])
{
KdbpPrint("CcTotalDirtyPages:\t%lu (%lu Kb)\n", CcTotalDirtyPages,
(CcTotalDirtyPages * PAGE_SIZE) / 1024);
KdbpPrint("CcDirtyPageThreshold:\t%lu (%lu Kb)\n", CcDirtyPageThreshold,
(CcDirtyPageThreshold * PAGE_SIZE) / 1024);
KdbpPrint("MmAvailablePages:\t%lu (%lu Kb)\n", MmAvailablePages,
(MmAvailablePages * PAGE_SIZE) / 1024);
KdbpPrint("MmThrottleTop:\t\t%lu (%lu Kb)\n", MmThrottleTop,
(MmThrottleTop * PAGE_SIZE) / 1024);
KdbpPrint("MmThrottleBottom:\t%lu (%lu Kb)\n", MmThrottleBottom,
(MmThrottleBottom * PAGE_SIZE) / 1024);
KdbpPrint("MmModifiedPageListHead.Total:\t%lu (%lu Kb)\n", MmModifiedPageListHead.Total,
(MmModifiedPageListHead.Total * PAGE_SIZE) / 1024);
if (CcTotalDirtyPages >= CcDirtyPageThreshold)
{
KdbpPrint("CcTotalDirtyPages above the threshold, writes should be throttled\n");
}
else if (CcTotalDirtyPages + 64 >= CcDirtyPageThreshold)
{
KdbpPrint("CcTotalDirtyPages within 64 (max charge) pages of the threshold, writes may be throttled\n");
}
else
{
KdbpPrint("CcTotalDirtyPages below the threshold, writes should not be throttled\n");
}
return TRUE;
}
#endif
/* EOF */