reactos/ntoskrnl/cc/fs.c

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/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
* FILE: ntoskrnl/cc/fs.c
* PURPOSE: Implements cache managers functions useful for File Systems
*
* PROGRAMMERS: Alex Ionescu
*/
/* INCLUDES ******************************************************************/
#include <ntoskrnl.h>
#define NDEBUG
#include <debug.h>
/* FUNCTIONS *****************************************************************/
/*
* @unimplemented
*/
LARGE_INTEGER
NTAPI
CcGetDirtyPages (
IN PVOID LogHandle,
IN PDIRTY_PAGE_ROUTINE DirtyPageRoutine,
IN PVOID Context1,
IN PVOID Context2)
{
LARGE_INTEGER i;
CCTRACE(CC_API_DEBUG, "LogHandle=%p DirtyPageRoutine=%p Context1=%p Context2=%p\n",
LogHandle, DirtyPageRoutine, Context1, Context2);
UNIMPLEMENTED;
i.QuadPart = 0;
return i;
}
/*
* @implemented
*/
PFILE_OBJECT
NTAPI
CcGetFileObjectFromBcb (
IN PVOID Bcb)
{
PINTERNAL_BCB iBcb = CONTAINING_RECORD(Bcb, INTERNAL_BCB, PFCB);
CCTRACE(CC_API_DEBUG, "Bcb=%p\n", Bcb);
return iBcb->Vacb->SharedCacheMap->FileObject;
}
/*
* @unimplemented
*/
LARGE_INTEGER
NTAPI
CcGetLsnForFileObject (
IN PFILE_OBJECT FileObject,
OUT PLARGE_INTEGER OldestLsn OPTIONAL)
{
LARGE_INTEGER i;
CCTRACE(CC_API_DEBUG, "FileObject=%p\n", FileObject);
UNIMPLEMENTED;
i.QuadPart = 0;
return i;
}
/*
* @unimplemented
*/
VOID
NTAPI
CcInitializeCacheMap (
IN PFILE_OBJECT FileObject,
IN PCC_FILE_SIZES FileSizes,
IN BOOLEAN PinAccess,
IN PCACHE_MANAGER_CALLBACKS CallBacks,
IN PVOID LazyWriterContext)
{
NTSTATUS Status;
ASSERT(FileObject);
ASSERT(FileSizes);
CCTRACE(CC_API_DEBUG, "FileObject=%p FileSizes=%p PinAccess=%d CallBacks=%p LazyWriterContext=%p\n",
FileObject, FileSizes, PinAccess, CallBacks, LazyWriterContext);
/* Call old ROS cache init function */
Status = CcRosInitializeFileCache(FileObject,
FileSizes,
PinAccess,
CallBacks,
LazyWriterContext);
if (!NT_SUCCESS(Status))
ExRaiseStatus(Status);
}
/*
* @implemented
*/
BOOLEAN
NTAPI
CcIsThereDirtyData (
IN PVPB Vpb)
{
PROS_VACB Vacb;
PLIST_ENTRY Entry;
KIRQL oldIrql;
/* Assume no dirty data */
BOOLEAN Dirty = FALSE;
CCTRACE(CC_API_DEBUG, "Vpb=%p\n", Vpb);
oldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
/* Browse dirty VACBs */
for (Entry = DirtyVacbListHead.Flink; Entry != &DirtyVacbListHead; Entry = Entry->Flink)
{
Vacb = CONTAINING_RECORD(Entry, ROS_VACB, DirtyVacbListEntry);
/* Look for these associated with our volume */
if (Vacb->SharedCacheMap->FileObject->Vpb != Vpb)
{
continue;
}
/* From now on, we are associated with our VPB */
/* Temporary files are not counted as dirty */
if (BooleanFlagOn(Vacb->SharedCacheMap->FileObject->Flags, FO_TEMPORARY_FILE))
{
continue;
}
/* A single dirty VACB is enough to have dirty data */
if (Vacb->Dirty)
{
Dirty = TRUE;
break;
}
}
KeReleaseQueuedSpinLock(LockQueueMasterLock, oldIrql);
return Dirty;
}
/*
* @unimplemented
*/
BOOLEAN
NTAPI
CcPurgeCacheSection (
IN PSECTION_OBJECT_POINTERS SectionObjectPointer,
IN PLARGE_INTEGER FileOffset OPTIONAL,
IN ULONG Length,
IN BOOLEAN UninitializeCacheMaps)
{
PROS_SHARED_CACHE_MAP SharedCacheMap;
PPRIVATE_CACHE_MAP PrivateCacheMap;
LONGLONG StartOffset;
LONGLONG EndOffset;
LIST_ENTRY FreeList;
KIRQL OldIrql;
PLIST_ENTRY ListEntry;
PROS_VACB Vacb;
LONGLONG ViewEnd;
BOOLEAN Success;
CCTRACE(CC_API_DEBUG, "SectionObjectPointer=%p\n FileOffset=%p Length=%lu UninitializeCacheMaps=%d",
SectionObjectPointer, FileOffset, Length, UninitializeCacheMaps);
/* Obtain the shared cache from the section */
SharedCacheMap = SectionObjectPointer->SharedCacheMap;
if (!SharedCacheMap)
{
Success = TRUE;
goto purgeMm;
}
if (UninitializeCacheMaps)
{
/*
* We have gotten the acknowledgement that
* the caller wants to unintialize the private
* cache maps so let's do this. Since we already
* have the shared cache map from above, iterate
* over that cache's private lists.
*/
while (!IsListEmpty(&SharedCacheMap->PrivateList))
{
/*
* This list is not empty, grab the
* private cache map.
*/
PrivateCacheMap = CONTAINING_RECORD(SharedCacheMap->PrivateList.Flink, PRIVATE_CACHE_MAP, PrivateLinks);
/* Unintialize the private cache now */
CcUninitializeCacheMap(PrivateCacheMap->FileObject, NULL, NULL);
}
}
StartOffset = FileOffset != NULL ? FileOffset->QuadPart : 0;
if (Length == 0 || FileOffset == NULL)
{
EndOffset = MAXLONGLONG;
}
else
{
EndOffset = StartOffset + Length;
ASSERT(EndOffset > StartOffset);
}
InitializeListHead(&FreeList);
/* Assume success */
Success = TRUE;
OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->CacheMapLock);
ListEntry = SharedCacheMap->CacheMapVacbListHead.Flink;
while (ListEntry != &SharedCacheMap->CacheMapVacbListHead)
{
ULONG Refs;
Vacb = CONTAINING_RECORD(ListEntry, ROS_VACB, CacheMapVacbListEntry);
ListEntry = ListEntry->Flink;
/* Skip VACBs outside the range, or only partially in range */
if (Vacb->FileOffset.QuadPart < StartOffset)
{
continue;
}
ViewEnd = min(Vacb->FileOffset.QuadPart + VACB_MAPPING_GRANULARITY,
SharedCacheMap->SectionSize.QuadPart);
if (ViewEnd >= EndOffset)
{
break;
}
/* Still in use, it cannot be purged, fail
* Allow one ref: VACB is supposed to be always 1-referenced
*/
Refs = CcRosVacbGetRefCount(Vacb);
if ((Refs > 1 && !Vacb->Dirty) ||
(Refs > 2 && Vacb->Dirty))
{
Success = FALSE;
break;
}
/* This VACB is in range, so unlink it and mark for free */
ASSERT(Refs == 1 || Vacb->Dirty);
RemoveEntryList(&Vacb->VacbLruListEntry);
InitializeListHead(&Vacb->VacbLruListEntry);
if (Vacb->Dirty)
{
CcRosUnmarkDirtyVacb(Vacb, FALSE);
}
RemoveEntryList(&Vacb->CacheMapVacbListEntry);
InsertHeadList(&FreeList, &Vacb->CacheMapVacbListEntry);
}
KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->CacheMapLock);
KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
while (!IsListEmpty(&FreeList))
{
ULONG Refs;
Vacb = CONTAINING_RECORD(RemoveHeadList(&FreeList),
ROS_VACB,
CacheMapVacbListEntry);
InitializeListHead(&Vacb->CacheMapVacbListEntry);
Refs = CcRosVacbDecRefCount(Vacb);
ASSERT(Refs == 0);
}
/* Now make sure that Mm doesn't hold some pages here. */
purgeMm:
if (Success)
Success = MmPurgeSegment(SectionObjectPointer, FileOffset, Length);
return Success;
}
/*
* @implemented
*/
VOID NTAPI
CcSetFileSizes (
IN PFILE_OBJECT FileObject,
IN PCC_FILE_SIZES FileSizes)
{
KIRQL OldIrql;
PROS_SHARED_CACHE_MAP SharedCacheMap;
LARGE_INTEGER OldSectionSize;
CCTRACE(CC_API_DEBUG, "FileObject=%p FileSizes=%p\n",
FileObject, FileSizes);
DPRINT("CcSetFileSizes(FileObject 0x%p, FileSizes 0x%p)\n",
FileObject, FileSizes);
DPRINT("AllocationSize %I64d, FileSize %I64d, ValidDataLength %I64d\n",
FileSizes->AllocationSize.QuadPart,
FileSizes->FileSize.QuadPart,
FileSizes->ValidDataLength.QuadPart);
SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
/*
* It is valid to call this function on file objects that weren't
* initialized for caching. In this case it's simple no-op.
*/
if (SharedCacheMap == NULL)
return;
/* Update the relevant fields */
KeAcquireSpinLock(&SharedCacheMap->CacheMapLock, &OldIrql);
OldSectionSize = SharedCacheMap->SectionSize;
SharedCacheMap->SectionSize = FileSizes->AllocationSize;
SharedCacheMap->FileSize = FileSizes->FileSize;
SharedCacheMap->ValidDataLength = FileSizes->ValidDataLength;
KeReleaseSpinLock(&SharedCacheMap->CacheMapLock, OldIrql);
if (FileSizes->AllocationSize.QuadPart < OldSectionSize.QuadPart)
{
CcPurgeCacheSection(FileObject->SectionObjectPointer,
&FileSizes->AllocationSize,
0,
FALSE);
}
else
{
/* Extend our section object */
MmExtendSection(SharedCacheMap->Section, &SharedCacheMap->SectionSize);
}
}
/*
* @unimplemented
*/
VOID
NTAPI
CcSetLogHandleForFile (
IN PFILE_OBJECT FileObject,
IN PVOID LogHandle,
IN PFLUSH_TO_LSN FlushToLsnRoutine)
{
CCTRACE(CC_API_DEBUG, "FileObject=%p LogHandle=%p FlushToLsnRoutine=%p\n",
FileObject, LogHandle, FlushToLsnRoutine);
UNIMPLEMENTED;
}
/*
* @unimplemented
*/
BOOLEAN
NTAPI
CcUninitializeCacheMap (
IN PFILE_OBJECT FileObject,
IN PLARGE_INTEGER TruncateSize OPTIONAL,
IN PCACHE_UNINITIALIZE_EVENT UninitializeCompleteEvent OPTIONAL)
{
NTSTATUS Status;
PROS_SHARED_CACHE_MAP SharedCacheMap;
KIRQL OldIrql;
CCTRACE(CC_API_DEBUG, "FileObject=%p TruncateSize=%p UninitializeCompleteEvent=%p\n",
FileObject, TruncateSize, UninitializeCompleteEvent);
if (TruncateSize != NULL &&
FileObject->SectionObjectPointer->SharedCacheMap != NULL)
{
SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
KeAcquireSpinLock(&SharedCacheMap->CacheMapLock, &OldIrql);
if (SharedCacheMap->FileSize.QuadPart > TruncateSize->QuadPart)
{
SharedCacheMap->FileSize = *TruncateSize;
}
KeReleaseSpinLock(&SharedCacheMap->CacheMapLock, OldIrql);
CcPurgeCacheSection(FileObject->SectionObjectPointer,
TruncateSize,
0,
FALSE);
}
Status = CcRosReleaseFileCache(FileObject);
if (UninitializeCompleteEvent)
{
KeSetEvent(&UninitializeCompleteEvent->Event, IO_NO_INCREMENT, FALSE);
}
return NT_SUCCESS(Status);
}
[NEWCC] A reintegration checkpoint for the NewCC branch, brought to you by Team NewCC. Differences with current ReactOS trunk: * A new memory area type, MEMORY_AREA_CACHE, is added, which represents a mapped region of a file. In NEWCC mode, user sections are MEMORY_AREA_CACHE type as well, and obey new semantics. In non-NEWCC mode, they aren't used. * A way of claiming a page entry for a specific thread's work is added. Placing the special SWAPENTRY value MM_WAIT_ENTRY in a page table, or in a section page table should indicate that memory management code is intended to wait for another thread to make some status change before checking the state of the page entry again. In code that uses this convention, a return value of STATUS_SUCCESS + 1 is used to indicate that the caller should use the MiWaitForPageEvent macro to wait until somebody has change the state of a wait entry before checking again. This is a lighter weight mechanism than PAGEOPs. * A way of asking the caller to perform some blocking operation without locks held is provided. This replaces some spaghettified code in which locks are repeatedly taken and broken by code that performs various blocking operations. Using this mechanism, it is possible to do a small amount of non-blocking work, fill in a request, then return STATUS_MORE_PROCESSING_REQUIRED to request that locks be dropped and the blocking operation be carried out. A MM_REQUIRED_RESOURCES structure is provided to consumers of this contract to use to accumulate state across many blocking operations. Several functions wrapping blocking operations are provided in ntoskrnl/cache/reqtools.c. * Image section pages are no longer direct mapped. This is done to simplify consolidation of ownership of pages under the data section system. At a later time, it may be possible to make data pages directly available to image sections for the same file. This is likely the only direct performance impact this code makes on non-NEWCC mode. RMAPs: * A new type of RMAP entry is introduced, distinguished by RMAP_IS_SEGMENT(Address) of the rmap entry. This kind of entry contains a pointer to a section page table node in the Process pointer, which in turn links back to the MM_SECTION_SEGMENT it belongs to. Therefore, a page belonging only to a segment (that is, a segment page that isn't mapped) can exist and be evicted using the normal page eviction mechanism in balance.c. Each of the rmap function has been modified to deal with segment rmaps. * The low 8 bits of the Address field in a segment rmap denote the entry number in the generic table node pointed to by Process that points to the page the rmap belongs to. By combining them, you can determine the file offset the page belongs to. * In NEWCC mode, MmSharePageEntry/UnsharePageEntry are not used, and instead the page reference count is used to keep track of the number of mappings of a page, allowing the last reference expiring to allow the page to be recycled without much intervention. These are still used in non-NEWCC mode. One change has been made, the count fields have been narrowed by 1 bit to make room for a dirty bit in SSE entries, needed when a page is present but unmapped. Section page tables: * The section page tables are now implemented using RtlGenericTables. This enables a fairly compact representation of section page tables without having the existence of a section object imply 4k of fake PDEs. In addition, each node in the generic table has a wide file offset that is a multiple of 256 pages, or 1 megabyte total. Besides needing wide file offsets, the only other visible change caused by the switch to generic tables for section page tables is the need to lock the section segment before interacting with the section page table. Eviction: * Page eviction in cache sections is accomplished by MmpPageOutPhysicalAddress. In the case of a shared page, it tries to remove all mappings of the indicated page. If this process fails at any point, the page will simply be drawn back into the target address spaces. After succeeding at this, if TRUE has been accumulated into the page's dirty bit in the section page table, it is written back, and then permanently removed. NewCC mode: * NEWCC mode is introduced, which rewrites the file cache to a set of cache stripes actively mapped, along with unmapped section data. * NewCC is more authentic in its interpretation of the external interface to the windows cache than the current cache manager, implementing each of the cache manager functions according to the documented interface with no preconceived ideas about how anything should be implemented internally. Cache stripes are implemented on top of section objects, using the same memory manager paths, and therefore economizing code and complexity. This replaces a rather complicated system in which pages can be owned by the cache manager and the memory manager simultaneously and they must cooperate in a fairly sophisticated way to manage them. Since they're quite interdependent in the current code, modifying either is very difficult. In NEWCC, they have a clear division of labor and thus can be worked on independently. * Several third party filesystems that use the kernel Cc interface work properly using NEWCC, including matt wu's ext3 driver. * In contrast with code that tries to make CcInitializeCacheMap and CcUninitializeCacheMap into a pair that supports reference counting, NEWCC lazily initializes the shared and private cache maps as needed and uses the presence of a PrivateCacheMap on at least one file pointing to the SharedCacheMap as an indication that the FILE_OBJECT reference in the SharedCacheMap should still be held. When the last PrivateCacheMap is discarded, that's the appropriate time to tear down caching for a specific file, as the SharedCacheMap data is allowed to be saved and reused. We honor this by making the SharedCacheMap into a depot for keeping track of the PrivateCacheMap objects associated with views of a file. svn path=/trunk/; revision=55833
2012-02-23 12:03:06 +00:00
BOOLEAN
NTAPI
CcGetFileSizes (
IN PFILE_OBJECT FileObject,
IN PCC_FILE_SIZES FileSizes)
[NEWCC] A reintegration checkpoint for the NewCC branch, brought to you by Team NewCC. Differences with current ReactOS trunk: * A new memory area type, MEMORY_AREA_CACHE, is added, which represents a mapped region of a file. In NEWCC mode, user sections are MEMORY_AREA_CACHE type as well, and obey new semantics. In non-NEWCC mode, they aren't used. * A way of claiming a page entry for a specific thread's work is added. Placing the special SWAPENTRY value MM_WAIT_ENTRY in a page table, or in a section page table should indicate that memory management code is intended to wait for another thread to make some status change before checking the state of the page entry again. In code that uses this convention, a return value of STATUS_SUCCESS + 1 is used to indicate that the caller should use the MiWaitForPageEvent macro to wait until somebody has change the state of a wait entry before checking again. This is a lighter weight mechanism than PAGEOPs. * A way of asking the caller to perform some blocking operation without locks held is provided. This replaces some spaghettified code in which locks are repeatedly taken and broken by code that performs various blocking operations. Using this mechanism, it is possible to do a small amount of non-blocking work, fill in a request, then return STATUS_MORE_PROCESSING_REQUIRED to request that locks be dropped and the blocking operation be carried out. A MM_REQUIRED_RESOURCES structure is provided to consumers of this contract to use to accumulate state across many blocking operations. Several functions wrapping blocking operations are provided in ntoskrnl/cache/reqtools.c. * Image section pages are no longer direct mapped. This is done to simplify consolidation of ownership of pages under the data section system. At a later time, it may be possible to make data pages directly available to image sections for the same file. This is likely the only direct performance impact this code makes on non-NEWCC mode. RMAPs: * A new type of RMAP entry is introduced, distinguished by RMAP_IS_SEGMENT(Address) of the rmap entry. This kind of entry contains a pointer to a section page table node in the Process pointer, which in turn links back to the MM_SECTION_SEGMENT it belongs to. Therefore, a page belonging only to a segment (that is, a segment page that isn't mapped) can exist and be evicted using the normal page eviction mechanism in balance.c. Each of the rmap function has been modified to deal with segment rmaps. * The low 8 bits of the Address field in a segment rmap denote the entry number in the generic table node pointed to by Process that points to the page the rmap belongs to. By combining them, you can determine the file offset the page belongs to. * In NEWCC mode, MmSharePageEntry/UnsharePageEntry are not used, and instead the page reference count is used to keep track of the number of mappings of a page, allowing the last reference expiring to allow the page to be recycled without much intervention. These are still used in non-NEWCC mode. One change has been made, the count fields have been narrowed by 1 bit to make room for a dirty bit in SSE entries, needed when a page is present but unmapped. Section page tables: * The section page tables are now implemented using RtlGenericTables. This enables a fairly compact representation of section page tables without having the existence of a section object imply 4k of fake PDEs. In addition, each node in the generic table has a wide file offset that is a multiple of 256 pages, or 1 megabyte total. Besides needing wide file offsets, the only other visible change caused by the switch to generic tables for section page tables is the need to lock the section segment before interacting with the section page table. Eviction: * Page eviction in cache sections is accomplished by MmpPageOutPhysicalAddress. In the case of a shared page, it tries to remove all mappings of the indicated page. If this process fails at any point, the page will simply be drawn back into the target address spaces. After succeeding at this, if TRUE has been accumulated into the page's dirty bit in the section page table, it is written back, and then permanently removed. NewCC mode: * NEWCC mode is introduced, which rewrites the file cache to a set of cache stripes actively mapped, along with unmapped section data. * NewCC is more authentic in its interpretation of the external interface to the windows cache than the current cache manager, implementing each of the cache manager functions according to the documented interface with no preconceived ideas about how anything should be implemented internally. Cache stripes are implemented on top of section objects, using the same memory manager paths, and therefore economizing code and complexity. This replaces a rather complicated system in which pages can be owned by the cache manager and the memory manager simultaneously and they must cooperate in a fairly sophisticated way to manage them. Since they're quite interdependent in the current code, modifying either is very difficult. In NEWCC, they have a clear division of labor and thus can be worked on independently. * Several third party filesystems that use the kernel Cc interface work properly using NEWCC, including matt wu's ext3 driver. * In contrast with code that tries to make CcInitializeCacheMap and CcUninitializeCacheMap into a pair that supports reference counting, NEWCC lazily initializes the shared and private cache maps as needed and uses the presence of a PrivateCacheMap on at least one file pointing to the SharedCacheMap as an indication that the FILE_OBJECT reference in the SharedCacheMap should still be held. When the last PrivateCacheMap is discarded, that's the appropriate time to tear down caching for a specific file, as the SharedCacheMap data is allowed to be saved and reused. We honor this by making the SharedCacheMap into a depot for keeping track of the PrivateCacheMap objects associated with views of a file. svn path=/trunk/; revision=55833
2012-02-23 12:03:06 +00:00
{
PROS_SHARED_CACHE_MAP SharedCacheMap;
SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
[NEWCC] A reintegration checkpoint for the NewCC branch, brought to you by Team NewCC. Differences with current ReactOS trunk: * A new memory area type, MEMORY_AREA_CACHE, is added, which represents a mapped region of a file. In NEWCC mode, user sections are MEMORY_AREA_CACHE type as well, and obey new semantics. In non-NEWCC mode, they aren't used. * A way of claiming a page entry for a specific thread's work is added. Placing the special SWAPENTRY value MM_WAIT_ENTRY in a page table, or in a section page table should indicate that memory management code is intended to wait for another thread to make some status change before checking the state of the page entry again. In code that uses this convention, a return value of STATUS_SUCCESS + 1 is used to indicate that the caller should use the MiWaitForPageEvent macro to wait until somebody has change the state of a wait entry before checking again. This is a lighter weight mechanism than PAGEOPs. * A way of asking the caller to perform some blocking operation without locks held is provided. This replaces some spaghettified code in which locks are repeatedly taken and broken by code that performs various blocking operations. Using this mechanism, it is possible to do a small amount of non-blocking work, fill in a request, then return STATUS_MORE_PROCESSING_REQUIRED to request that locks be dropped and the blocking operation be carried out. A MM_REQUIRED_RESOURCES structure is provided to consumers of this contract to use to accumulate state across many blocking operations. Several functions wrapping blocking operations are provided in ntoskrnl/cache/reqtools.c. * Image section pages are no longer direct mapped. This is done to simplify consolidation of ownership of pages under the data section system. At a later time, it may be possible to make data pages directly available to image sections for the same file. This is likely the only direct performance impact this code makes on non-NEWCC mode. RMAPs: * A new type of RMAP entry is introduced, distinguished by RMAP_IS_SEGMENT(Address) of the rmap entry. This kind of entry contains a pointer to a section page table node in the Process pointer, which in turn links back to the MM_SECTION_SEGMENT it belongs to. Therefore, a page belonging only to a segment (that is, a segment page that isn't mapped) can exist and be evicted using the normal page eviction mechanism in balance.c. Each of the rmap function has been modified to deal with segment rmaps. * The low 8 bits of the Address field in a segment rmap denote the entry number in the generic table node pointed to by Process that points to the page the rmap belongs to. By combining them, you can determine the file offset the page belongs to. * In NEWCC mode, MmSharePageEntry/UnsharePageEntry are not used, and instead the page reference count is used to keep track of the number of mappings of a page, allowing the last reference expiring to allow the page to be recycled without much intervention. These are still used in non-NEWCC mode. One change has been made, the count fields have been narrowed by 1 bit to make room for a dirty bit in SSE entries, needed when a page is present but unmapped. Section page tables: * The section page tables are now implemented using RtlGenericTables. This enables a fairly compact representation of section page tables without having the existence of a section object imply 4k of fake PDEs. In addition, each node in the generic table has a wide file offset that is a multiple of 256 pages, or 1 megabyte total. Besides needing wide file offsets, the only other visible change caused by the switch to generic tables for section page tables is the need to lock the section segment before interacting with the section page table. Eviction: * Page eviction in cache sections is accomplished by MmpPageOutPhysicalAddress. In the case of a shared page, it tries to remove all mappings of the indicated page. If this process fails at any point, the page will simply be drawn back into the target address spaces. After succeeding at this, if TRUE has been accumulated into the page's dirty bit in the section page table, it is written back, and then permanently removed. NewCC mode: * NEWCC mode is introduced, which rewrites the file cache to a set of cache stripes actively mapped, along with unmapped section data. * NewCC is more authentic in its interpretation of the external interface to the windows cache than the current cache manager, implementing each of the cache manager functions according to the documented interface with no preconceived ideas about how anything should be implemented internally. Cache stripes are implemented on top of section objects, using the same memory manager paths, and therefore economizing code and complexity. This replaces a rather complicated system in which pages can be owned by the cache manager and the memory manager simultaneously and they must cooperate in a fairly sophisticated way to manage them. Since they're quite interdependent in the current code, modifying either is very difficult. In NEWCC, they have a clear division of labor and thus can be worked on independently. * Several third party filesystems that use the kernel Cc interface work properly using NEWCC, including matt wu's ext3 driver. * In contrast with code that tries to make CcInitializeCacheMap and CcUninitializeCacheMap into a pair that supports reference counting, NEWCC lazily initializes the shared and private cache maps as needed and uses the presence of a PrivateCacheMap on at least one file pointing to the SharedCacheMap as an indication that the FILE_OBJECT reference in the SharedCacheMap should still be held. When the last PrivateCacheMap is discarded, that's the appropriate time to tear down caching for a specific file, as the SharedCacheMap data is allowed to be saved and reused. We honor this by making the SharedCacheMap into a depot for keeping track of the PrivateCacheMap objects associated with views of a file. svn path=/trunk/; revision=55833
2012-02-23 12:03:06 +00:00
if (!SharedCacheMap)
return FALSE;
[NEWCC] A reintegration checkpoint for the NewCC branch, brought to you by Team NewCC. Differences with current ReactOS trunk: * A new memory area type, MEMORY_AREA_CACHE, is added, which represents a mapped region of a file. In NEWCC mode, user sections are MEMORY_AREA_CACHE type as well, and obey new semantics. In non-NEWCC mode, they aren't used. * A way of claiming a page entry for a specific thread's work is added. Placing the special SWAPENTRY value MM_WAIT_ENTRY in a page table, or in a section page table should indicate that memory management code is intended to wait for another thread to make some status change before checking the state of the page entry again. In code that uses this convention, a return value of STATUS_SUCCESS + 1 is used to indicate that the caller should use the MiWaitForPageEvent macro to wait until somebody has change the state of a wait entry before checking again. This is a lighter weight mechanism than PAGEOPs. * A way of asking the caller to perform some blocking operation without locks held is provided. This replaces some spaghettified code in which locks are repeatedly taken and broken by code that performs various blocking operations. Using this mechanism, it is possible to do a small amount of non-blocking work, fill in a request, then return STATUS_MORE_PROCESSING_REQUIRED to request that locks be dropped and the blocking operation be carried out. A MM_REQUIRED_RESOURCES structure is provided to consumers of this contract to use to accumulate state across many blocking operations. Several functions wrapping blocking operations are provided in ntoskrnl/cache/reqtools.c. * Image section pages are no longer direct mapped. This is done to simplify consolidation of ownership of pages under the data section system. At a later time, it may be possible to make data pages directly available to image sections for the same file. This is likely the only direct performance impact this code makes on non-NEWCC mode. RMAPs: * A new type of RMAP entry is introduced, distinguished by RMAP_IS_SEGMENT(Address) of the rmap entry. This kind of entry contains a pointer to a section page table node in the Process pointer, which in turn links back to the MM_SECTION_SEGMENT it belongs to. Therefore, a page belonging only to a segment (that is, a segment page that isn't mapped) can exist and be evicted using the normal page eviction mechanism in balance.c. Each of the rmap function has been modified to deal with segment rmaps. * The low 8 bits of the Address field in a segment rmap denote the entry number in the generic table node pointed to by Process that points to the page the rmap belongs to. By combining them, you can determine the file offset the page belongs to. * In NEWCC mode, MmSharePageEntry/UnsharePageEntry are not used, and instead the page reference count is used to keep track of the number of mappings of a page, allowing the last reference expiring to allow the page to be recycled without much intervention. These are still used in non-NEWCC mode. One change has been made, the count fields have been narrowed by 1 bit to make room for a dirty bit in SSE entries, needed when a page is present but unmapped. Section page tables: * The section page tables are now implemented using RtlGenericTables. This enables a fairly compact representation of section page tables without having the existence of a section object imply 4k of fake PDEs. In addition, each node in the generic table has a wide file offset that is a multiple of 256 pages, or 1 megabyte total. Besides needing wide file offsets, the only other visible change caused by the switch to generic tables for section page tables is the need to lock the section segment before interacting with the section page table. Eviction: * Page eviction in cache sections is accomplished by MmpPageOutPhysicalAddress. In the case of a shared page, it tries to remove all mappings of the indicated page. If this process fails at any point, the page will simply be drawn back into the target address spaces. After succeeding at this, if TRUE has been accumulated into the page's dirty bit in the section page table, it is written back, and then permanently removed. NewCC mode: * NEWCC mode is introduced, which rewrites the file cache to a set of cache stripes actively mapped, along with unmapped section data. * NewCC is more authentic in its interpretation of the external interface to the windows cache than the current cache manager, implementing each of the cache manager functions according to the documented interface with no preconceived ideas about how anything should be implemented internally. Cache stripes are implemented on top of section objects, using the same memory manager paths, and therefore economizing code and complexity. This replaces a rather complicated system in which pages can be owned by the cache manager and the memory manager simultaneously and they must cooperate in a fairly sophisticated way to manage them. Since they're quite interdependent in the current code, modifying either is very difficult. In NEWCC, they have a clear division of labor and thus can be worked on independently. * Several third party filesystems that use the kernel Cc interface work properly using NEWCC, including matt wu's ext3 driver. * In contrast with code that tries to make CcInitializeCacheMap and CcUninitializeCacheMap into a pair that supports reference counting, NEWCC lazily initializes the shared and private cache maps as needed and uses the presence of a PrivateCacheMap on at least one file pointing to the SharedCacheMap as an indication that the FILE_OBJECT reference in the SharedCacheMap should still be held. When the last PrivateCacheMap is discarded, that's the appropriate time to tear down caching for a specific file, as the SharedCacheMap data is allowed to be saved and reused. We honor this by making the SharedCacheMap into a depot for keeping track of the PrivateCacheMap objects associated with views of a file. svn path=/trunk/; revision=55833
2012-02-23 12:03:06 +00:00
FileSizes->AllocationSize = SharedCacheMap->SectionSize;
FileSizes->FileSize = FileSizes->ValidDataLength = SharedCacheMap->FileSize;
return TRUE;
[NEWCC] A reintegration checkpoint for the NewCC branch, brought to you by Team NewCC. Differences with current ReactOS trunk: * A new memory area type, MEMORY_AREA_CACHE, is added, which represents a mapped region of a file. In NEWCC mode, user sections are MEMORY_AREA_CACHE type as well, and obey new semantics. In non-NEWCC mode, they aren't used. * A way of claiming a page entry for a specific thread's work is added. Placing the special SWAPENTRY value MM_WAIT_ENTRY in a page table, or in a section page table should indicate that memory management code is intended to wait for another thread to make some status change before checking the state of the page entry again. In code that uses this convention, a return value of STATUS_SUCCESS + 1 is used to indicate that the caller should use the MiWaitForPageEvent macro to wait until somebody has change the state of a wait entry before checking again. This is a lighter weight mechanism than PAGEOPs. * A way of asking the caller to perform some blocking operation without locks held is provided. This replaces some spaghettified code in which locks are repeatedly taken and broken by code that performs various blocking operations. Using this mechanism, it is possible to do a small amount of non-blocking work, fill in a request, then return STATUS_MORE_PROCESSING_REQUIRED to request that locks be dropped and the blocking operation be carried out. A MM_REQUIRED_RESOURCES structure is provided to consumers of this contract to use to accumulate state across many blocking operations. Several functions wrapping blocking operations are provided in ntoskrnl/cache/reqtools.c. * Image section pages are no longer direct mapped. This is done to simplify consolidation of ownership of pages under the data section system. At a later time, it may be possible to make data pages directly available to image sections for the same file. This is likely the only direct performance impact this code makes on non-NEWCC mode. RMAPs: * A new type of RMAP entry is introduced, distinguished by RMAP_IS_SEGMENT(Address) of the rmap entry. This kind of entry contains a pointer to a section page table node in the Process pointer, which in turn links back to the MM_SECTION_SEGMENT it belongs to. Therefore, a page belonging only to a segment (that is, a segment page that isn't mapped) can exist and be evicted using the normal page eviction mechanism in balance.c. Each of the rmap function has been modified to deal with segment rmaps. * The low 8 bits of the Address field in a segment rmap denote the entry number in the generic table node pointed to by Process that points to the page the rmap belongs to. By combining them, you can determine the file offset the page belongs to. * In NEWCC mode, MmSharePageEntry/UnsharePageEntry are not used, and instead the page reference count is used to keep track of the number of mappings of a page, allowing the last reference expiring to allow the page to be recycled without much intervention. These are still used in non-NEWCC mode. One change has been made, the count fields have been narrowed by 1 bit to make room for a dirty bit in SSE entries, needed when a page is present but unmapped. Section page tables: * The section page tables are now implemented using RtlGenericTables. This enables a fairly compact representation of section page tables without having the existence of a section object imply 4k of fake PDEs. In addition, each node in the generic table has a wide file offset that is a multiple of 256 pages, or 1 megabyte total. Besides needing wide file offsets, the only other visible change caused by the switch to generic tables for section page tables is the need to lock the section segment before interacting with the section page table. Eviction: * Page eviction in cache sections is accomplished by MmpPageOutPhysicalAddress. In the case of a shared page, it tries to remove all mappings of the indicated page. If this process fails at any point, the page will simply be drawn back into the target address spaces. After succeeding at this, if TRUE has been accumulated into the page's dirty bit in the section page table, it is written back, and then permanently removed. NewCC mode: * NEWCC mode is introduced, which rewrites the file cache to a set of cache stripes actively mapped, along with unmapped section data. * NewCC is more authentic in its interpretation of the external interface to the windows cache than the current cache manager, implementing each of the cache manager functions according to the documented interface with no preconceived ideas about how anything should be implemented internally. Cache stripes are implemented on top of section objects, using the same memory manager paths, and therefore economizing code and complexity. This replaces a rather complicated system in which pages can be owned by the cache manager and the memory manager simultaneously and they must cooperate in a fairly sophisticated way to manage them. Since they're quite interdependent in the current code, modifying either is very difficult. In NEWCC, they have a clear division of labor and thus can be worked on independently. * Several third party filesystems that use the kernel Cc interface work properly using NEWCC, including matt wu's ext3 driver. * In contrast with code that tries to make CcInitializeCacheMap and CcUninitializeCacheMap into a pair that supports reference counting, NEWCC lazily initializes the shared and private cache maps as needed and uses the presence of a PrivateCacheMap on at least one file pointing to the SharedCacheMap as an indication that the FILE_OBJECT reference in the SharedCacheMap should still be held. When the last PrivateCacheMap is discarded, that's the appropriate time to tear down caching for a specific file, as the SharedCacheMap data is allowed to be saved and reused. We honor this by making the SharedCacheMap into a depot for keeping track of the PrivateCacheMap objects associated with views of a file. svn path=/trunk/; revision=55833
2012-02-23 12:03:06 +00:00
}