1000 lines
29 KiB
C
1000 lines
29 KiB
C
/*++
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Copyright (c) 1990 Microsoft Corporation
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Module Name:
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mdlsup.c
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Abstract:
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This module implements the Mdl support routines for the Cache subsystem.
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Author:
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Tom Miller [TomM] 4-May-1990
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Revision History:
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--*/
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#include "cc.h"
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//
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// Debug Trace Level
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//
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#define me (0x00000010)
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VOID
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CcMdlRead (
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IN PFILE_OBJECT FileObject,
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IN PLARGE_INTEGER FileOffset,
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IN ULONG Length,
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OUT PMDL *MdlChain,
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OUT PIO_STATUS_BLOCK IoStatus
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)
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/*++
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Routine Description:
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This routine attempts to lock the specified file data in the cache
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and return a description of it in an Mdl along with the correct
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I/O status. It is *not* safe to call this routine from Dpc level.
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This routine is synchronous, and raises on errors.
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As each call returns, the pages described by the Mdl are
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locked in memory, but not mapped in system space. If the caller
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needs the pages mapped in system space, then it must map them.
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Note that each call is a "single shot" which should be followed by
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a call to CcMdlReadComplete. To resume an Mdl-based transfer, the
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caller must form one or more subsequent calls to CcMdlRead with
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appropriately adjusted parameters.
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Arguments:
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FileObject - Pointer to the file object for a file which was
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opened with NO_INTERMEDIATE_BUFFERING clear, i.e., for
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which CcInitializeCacheMap was called by the file system.
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FileOffset - Byte offset in file for desired data.
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Length - Length of desired data in bytes.
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MdlChain - On output it returns a pointer to an Mdl chain describing
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the desired data. Note that even if FALSE is returned,
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one or more Mdls may have been allocated, as may be ascertained
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by the IoStatus.Information field (see below).
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IoStatus - Pointer to standard I/O status block to receive the status
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for the transfer. (STATUS_SUCCESS guaranteed for cache
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hits, otherwise the actual I/O status is returned.) The
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I/O Information Field indicates how many bytes have been
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successfully locked down in the Mdl Chain.
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Return Value:
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None
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Raises:
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STATUS_INSUFFICIENT_RESOURCES - If a pool allocation failure occurs.
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--*/
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{
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PSHARED_CACHE_MAP SharedCacheMap;
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PPRIVATE_CACHE_MAP PrivateCacheMap;
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PVOID CacheBuffer;
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LARGE_INTEGER FOffset;
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PMDL Mdl;
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PMDL MdlTemp;
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ULONG SavedState = 0;
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ULONG OriginalLength = Length;
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ULONG Information = 0;
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PVACB Vacb = NULL;
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ULONG SavedMissCounter = 0;
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KIRQL OldIrql;
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ULONG ActivePage;
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ULONG PageIsDirty;
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PVACB ActiveVacb = NULL;
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DebugTrace(+1, me, "CcMdlRead\n", 0 );
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DebugTrace( 0, me, " FileObject = %08lx\n", FileObject );
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DebugTrace2(0, me, " FileOffset = %08lx, %08lx\n", FileOffset->LowPart,
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FileOffset->HighPart );
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DebugTrace( 0, me, " Length = %08lx\n", Length );
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//
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// Get pointer to SharedCacheMap.
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//
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SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
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PrivateCacheMap = FileObject->PrivateCacheMap;
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//
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// See if we have an active Vacb, that we need to free.
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//
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GetActiveVacb( SharedCacheMap, OldIrql, ActiveVacb, ActivePage, PageIsDirty );
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//
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// If there is an end of a page to be zeroed, then free that page now,
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// so we don't send Greg the uninitialized data...
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//
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if ((ActiveVacb != NULL) || (SharedCacheMap->NeedToZero != NULL)) {
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CcFreeActiveVacb( SharedCacheMap, ActiveVacb, ActivePage, PageIsDirty );
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}
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//
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// If read ahead is enabled, then do the read ahead here so it
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// overlaps with the copy (otherwise we will do it below).
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// Note that we are assuming that we will not get ahead of our
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// current transfer - if read ahead is working it should either
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// already be in memory or else underway.
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//
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if (PrivateCacheMap->ReadAheadEnabled && (PrivateCacheMap->ReadAheadLength[1] == 0)) {
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CcScheduleReadAhead( FileObject, FileOffset, Length );
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}
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//
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// Increment performance counters
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//
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CcMdlReadWait += 1;
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//
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// This is not an exact solution, but when IoPageRead gets a miss,
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// it cannot tell whether it was CcCopyRead or CcMdlRead, but since
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// the miss should occur very soon, by loading the pointer here
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// probably the right counter will get incremented, and in any case,
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// we hope the errrors average out!
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//
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CcMissCounter = &CcMdlReadWaitMiss;
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FOffset = *FileOffset;
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//
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// Check for read past file size, the caller must filter this case out.
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//
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ASSERT( ( FOffset.QuadPart + (LONGLONG)Length ) <= SharedCacheMap->FileSize.QuadPart );
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//
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// Put try-finally around the loop to deal with any exceptions
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//
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try {
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//
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// Not all of the transfer will come back at once, so we have to loop
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// until the entire transfer is complete.
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//
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while (Length != 0) {
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ULONG ReceivedLength;
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LARGE_INTEGER BeyondLastByte;
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//
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// Map the data and read it in (if necessary) with the
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// MmProbeAndLockPages call below.
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//
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CacheBuffer = CcGetVirtualAddress( SharedCacheMap,
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FOffset,
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&Vacb,
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&ReceivedLength );
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if (ReceivedLength > Length) {
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ReceivedLength = Length;
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}
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BeyondLastByte.QuadPart = FOffset.QuadPart + (LONGLONG)ReceivedLength;
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//
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// Now attempt to allocate an Mdl to describe the mapped data.
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//
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DebugTrace( 0, mm, "IoAllocateMdl:\n", 0 );
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DebugTrace( 0, mm, " BaseAddress = %08lx\n", CacheBuffer );
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DebugTrace( 0, mm, " Length = %08lx\n", ReceivedLength );
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Mdl = IoAllocateMdl( CacheBuffer,
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ReceivedLength,
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FALSE,
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FALSE,
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NULL );
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DebugTrace( 0, mm, " <Mdl = %08lx\n", Mdl );
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if (Mdl == NULL) {
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DebugTrace( 0, 0, "Failed to allocate Mdl\n", 0 );
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ExRaiseStatus( STATUS_INSUFFICIENT_RESOURCES );
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}
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DebugTrace( 0, mm, "MmProbeAndLockPages:\n", 0 );
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DebugTrace( 0, mm, " Mdl = %08lx\n", Mdl );
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//
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// Note that this probe should never fail, because we can
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// trust the address returned from CcPinFileData. Therefore,
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// if we succeed in allocating the Mdl above, we should
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// manage to elude any expected exceptions through the end
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// of this loop.
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//
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//
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// Set to see if the miss counter changes in order to
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// detect when we should turn on read ahead.
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//
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SavedMissCounter += CcMdlReadWaitMiss;
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MmDisablePageFaultClustering(&SavedState);
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MmProbeAndLockPages( Mdl, KernelMode, IoReadAccess );
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MmEnablePageFaultClustering(SavedState);
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SavedState = 0;
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SavedMissCounter -= CcMdlReadWaitMiss;
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//
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// Unmap the data now, now that the pages are locked down.
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//
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CcFreeVirtualAddress( Vacb );
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Vacb = NULL;
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//
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// Now link the Mdl into the caller's chain
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//
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if ( *MdlChain == NULL ) {
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*MdlChain = Mdl;
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} else {
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MdlTemp = CONTAINING_RECORD( *MdlChain, MDL, Next );
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while (MdlTemp->Next != NULL) {
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MdlTemp = MdlTemp->Next;
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}
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MdlTemp->Next = Mdl;
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}
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//
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// Assume we did not get all the data we wanted, and set FOffset
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// to the end of the returned data.
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//
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FOffset = BeyondLastByte;
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//
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// Update number of bytes transferred.
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//
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Information += ReceivedLength;
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//
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// Calculate length left to transfer.
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//
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Length -= ReceivedLength;
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}
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}
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finally {
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CcMissCounter = &CcThrowAway;
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if (AbnormalTermination()) {
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if (SavedState != 0) {
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MmEnablePageFaultClustering(SavedState);
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}
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//
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// We may have failed to allocate an Mdl while still having
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// data mapped.
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//
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if (Vacb != NULL) {
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CcFreeVirtualAddress( Vacb );
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}
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//
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// Otherwise loop to deallocate the Mdls
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//
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while (*MdlChain != NULL) {
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MdlTemp = (*MdlChain)->Next;
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DebugTrace( 0, mm, "MmUnlockPages/IoFreeMdl:\n", 0 );
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DebugTrace( 0, mm, " Mdl = %08lx\n", *MdlChain );
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MmUnlockPages( *MdlChain );
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IoFreeMdl( *MdlChain );
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*MdlChain = MdlTemp;
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}
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DebugTrace(-1, me, "CcMdlRead -> Unwinding\n", 0 );
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}
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else {
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//
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// Now enable read ahead if it looks like we got any misses, and do
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// the first one.
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//
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if (!PrivateCacheMap->ReadAheadEnabled && (SavedMissCounter != 0)) {
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PrivateCacheMap->ReadAheadEnabled = TRUE;
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CcScheduleReadAhead( FileObject, FileOffset, OriginalLength );
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}
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//
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// Now that we have described our desired read ahead, let's
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// shift the read history down.
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//
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PrivateCacheMap->FileOffset1 = PrivateCacheMap->FileOffset2;
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PrivateCacheMap->BeyondLastByte1 = PrivateCacheMap->BeyondLastByte2;
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PrivateCacheMap->FileOffset2 = *FileOffset;
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PrivateCacheMap->BeyondLastByte2.QuadPart =
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FileOffset->QuadPart + (LONGLONG)OriginalLength;
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IoStatus->Status = STATUS_SUCCESS;
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IoStatus->Information = Information;
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}
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}
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DebugTrace( 0, me, " <MdlChain = %08lx\n", *MdlChain );
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DebugTrace2(0, me, " <IoStatus = %08lx, %08lx\n", IoStatus->Status,
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IoStatus->Information );
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DebugTrace(-1, me, "CcMdlRead -> VOID\n", 0 );
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return;
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}
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//
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// First we have the old routine which checks for an entry in the FastIo vector.
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// This routine becomes obsolete for every component that compiles with the new
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// definition of FsRtlMdlReadComplete in fsrtl.h.
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//
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VOID
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CcMdlReadComplete (
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IN PFILE_OBJECT FileObject,
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IN PMDL MdlChain
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)
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{
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PDEVICE_OBJECT DeviceObject;
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PFAST_IO_DISPATCH FastIoDispatch;
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DeviceObject = IoGetRelatedDeviceObject( FileObject );
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FastIoDispatch = DeviceObject->DriverObject->FastIoDispatch;
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if ((FastIoDispatch != NULL) &&
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(FastIoDispatch->SizeOfFastIoDispatch > FIELD_OFFSET(FAST_IO_DISPATCH, MdlWriteComplete)) &&
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(FastIoDispatch->MdlReadComplete != NULL)) {
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FastIoDispatch->MdlReadComplete( FileObject, MdlChain, DeviceObject );
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} else {
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CcMdlReadComplete2( FileObject, MdlChain );
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}
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}
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VOID
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CcMdlReadComplete2 (
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IN PFILE_OBJECT FileObject,
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IN PMDL MdlChain
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)
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/*++
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Routine Description:
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This routine must be called at IPL0 after a call to CcMdlRead. The
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caller must simply supply the address of the MdlChain returned in
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CcMdlRead.
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This call does the following:
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Deletes the MdlChain
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Arguments:
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FileObject - Pointer to the file object for a file which was
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opened with NO_INTERMEDIATE_BUFFERING clear, i.e., for
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which CcInitializeCacheMap was called by the file system.
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MdlChain - same as returned from corresponding call to CcMdlRead.
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Return Value:
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None.
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--*/
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{
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PMDL MdlNext;
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DebugTrace(+1, me, "CcMdlReadComplete\n", 0 );
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DebugTrace( 0, me, " FileObject = %08lx\n", FileObject );
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DebugTrace( 0, me, " MdlChain = %08lx\n", MdlChain );
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//
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// Deallocate the Mdls
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//
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while (MdlChain != NULL) {
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MdlNext = MdlChain->Next;
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DebugTrace( 0, mm, "MmUnlockPages/IoFreeMdl:\n", 0 );
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DebugTrace( 0, mm, " Mdl = %08lx\n", MdlChain );
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MmUnlockPages( MdlChain );
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IoFreeMdl( MdlChain );
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MdlChain = MdlNext;
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}
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DebugTrace(-1, me, "CcMdlReadComplete -> VOID\n", 0 );
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}
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VOID
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CcPrepareMdlWrite (
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IN PFILE_OBJECT FileObject,
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IN PLARGE_INTEGER FileOffset,
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IN ULONG Length,
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OUT PMDL *MdlChain,
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OUT PIO_STATUS_BLOCK IoStatus
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)
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/*++
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Routine Description:
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This routine attempts to lock the specified file data in the cache
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and return a description of it in an Mdl along with the correct
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I/O status. Pages to be completely overwritten may be satisfied
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with emtpy pages. It is *not* safe to call this routine from Dpc level.
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This call is synchronous and raises on error.
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When this call returns, the caller may immediately begin
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to transfer data into the buffers via the Mdl.
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When the call returns with TRUE, the pages described by the Mdl are
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locked in memory, but not mapped in system space. If the caller
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needs the pages mapped in system space, then it must map them.
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On the subsequent call to CcMdlWriteComplete the pages will be
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unmapped if they were mapped, and in any case unlocked and the Mdl
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deallocated.
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Arguments:
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FileObject - Pointer to the file object for a file which was
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opened with NO_INTERMEDIATE_BUFFERING clear, i.e., for
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which CcInitializeCacheMap was called by the file system.
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FileOffset - Byte offset in file for desired data.
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Length - Length of desired data in bytes.
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MdlChain - On output it returns a pointer to an Mdl chain describing
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the desired data. Note that even if FALSE is returned,
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one or more Mdls may have been allocated, as may be ascertained
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by the IoStatus.Information field (see below).
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IoStatus - Pointer to standard I/O status block to receive the status
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for the in-transfer of the data. (STATUS_SUCCESS guaranteed
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for cache hits, otherwise the actual I/O status is returned.)
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The I/O Information Field indicates how many bytes have been
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successfully locked down in the Mdl Chain.
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Return Value:
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None
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--*/
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{
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PSHARED_CACHE_MAP SharedCacheMap;
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PVOID CacheBuffer;
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LARGE_INTEGER FOffset;
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PVACB Vacb;
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PMDL Mdl;
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PMDL MdlTemp;
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LARGE_INTEGER Temp;
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ULONG SavedState = 0;
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ULONG ZeroFlags = 0;
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ULONG Information = 0;
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KIRQL OldIrql;
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ULONG ActivePage;
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ULONG PageIsDirty;
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PVACB ActiveVacb = NULL;
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DebugTrace(+1, me, "CcPrepareMdlWrite\n", 0 );
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DebugTrace( 0, me, " FileObject = %08lx\n", FileObject );
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DebugTrace2(0, me, " FileOffset = %08lx, %08lx\n", FileOffset->LowPart,
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FileOffset->HighPart );
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DebugTrace( 0, me, " Length = %08lx\n", Length );
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//
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// Get pointer to SharedCacheMap.
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//
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SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
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//
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// See if we have an active Vacb, that we need to free.
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//
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GetActiveVacb( SharedCacheMap, OldIrql, ActiveVacb, ActivePage, PageIsDirty );
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//
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// If there is an end of a page to be zeroed, then free that page now,
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// so it does not cause our data to get zeroed. If there is an active
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// page, free it so we have the correct ValidDataGoal.
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//
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if ((ActiveVacb != NULL) || (SharedCacheMap->NeedToZero != NULL)) {
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CcFreeActiveVacb( SharedCacheMap, ActiveVacb, ActivePage, PageIsDirty );
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}
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FOffset = *FileOffset;
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//
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// Put try-finally around the loop to deal with exceptions
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//
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try {
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//
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// Not all of the transfer will come back at once, so we have to loop
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// until the entire transfer is complete.
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//
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while (Length != 0) {
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ULONG ReceivedLength;
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LARGE_INTEGER BeyondLastByte;
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//
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// Calculate how much we could potentially access at this
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// FileOffset, then cut it down if it is more than we need.
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//
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ReceivedLength = VACB_MAPPING_GRANULARITY -
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(FOffset.LowPart & (VACB_MAPPING_GRANULARITY - 1));
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if (ReceivedLength > Length) {
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||
ReceivedLength = Length;
|
||
}
|
||
|
||
BeyondLastByte.QuadPart = FOffset.QuadPart + (LONGLONG)ReceivedLength;
|
||
|
||
//
|
||
// At this point we can calculate the ZeroFlags.
|
||
//
|
||
|
||
//
|
||
// We can always zero middle pages, if any.
|
||
//
|
||
|
||
ZeroFlags = ZERO_MIDDLE_PAGES;
|
||
|
||
//
|
||
// See if we are completely overwriting the first or last page.
|
||
//
|
||
|
||
if (((FOffset.LowPart & (PAGE_SIZE - 1)) == 0) &&
|
||
(ReceivedLength >= PAGE_SIZE)) {
|
||
ZeroFlags |= ZERO_FIRST_PAGE;
|
||
}
|
||
|
||
if ((BeyondLastByte.LowPart & (PAGE_SIZE - 1)) == 0) {
|
||
ZeroFlags |= ZERO_LAST_PAGE;
|
||
}
|
||
|
||
//
|
||
// See if the entire transfer is beyond valid data length,
|
||
// or at least starting from the second page.
|
||
//
|
||
|
||
Temp = FOffset;
|
||
Temp.LowPart &= ~(PAGE_SIZE -1);
|
||
Temp.QuadPart = SharedCacheMap->ValidDataGoal.QuadPart - Temp.QuadPart;
|
||
|
||
if (Temp.QuadPart <= 0) {
|
||
ZeroFlags |= ZERO_FIRST_PAGE | ZERO_MIDDLE_PAGES | ZERO_LAST_PAGE;
|
||
} else if ((Temp.HighPart == 0) && (Temp.LowPart <= PAGE_SIZE)) {
|
||
ZeroFlags |= ZERO_MIDDLE_PAGES | ZERO_LAST_PAGE;
|
||
}
|
||
|
||
(VOID)CcMapAndRead( SharedCacheMap,
|
||
&FOffset,
|
||
ReceivedLength,
|
||
ZeroFlags,
|
||
TRUE,
|
||
&Vacb,
|
||
&CacheBuffer );
|
||
|
||
//
|
||
// Now attempt to allocate an Mdl to describe the mapped data.
|
||
//
|
||
|
||
DebugTrace( 0, mm, "IoAllocateMdl:\n", 0 );
|
||
DebugTrace( 0, mm, " BaseAddress = %08lx\n", CacheBuffer );
|
||
DebugTrace( 0, mm, " Length = %08lx\n", ReceivedLength );
|
||
|
||
Mdl = IoAllocateMdl( CacheBuffer,
|
||
ReceivedLength,
|
||
FALSE,
|
||
FALSE,
|
||
NULL );
|
||
|
||
DebugTrace( 0, mm, " <Mdl = %08lx\n", Mdl );
|
||
|
||
if (Mdl == NULL) {
|
||
DebugTrace( 0, 0, "Failed to allocate Mdl\n", 0 );
|
||
|
||
ExRaiseStatus( STATUS_INSUFFICIENT_RESOURCES );
|
||
}
|
||
|
||
DebugTrace( 0, mm, "MmProbeAndLockPages:\n", 0 );
|
||
DebugTrace( 0, mm, " Mdl = %08lx\n", Mdl );
|
||
|
||
//
|
||
// Note that this probe should never fail, because we can
|
||
// trust the address returned from CcPinFileData. Therefore,
|
||
// if we succeed in allocating the Mdl above, we should
|
||
// manage to elude any expected exceptions through the end
|
||
// of this loop.
|
||
//
|
||
|
||
MmDisablePageFaultClustering(&SavedState);
|
||
MmProbeAndLockPages( Mdl, KernelMode, IoWriteAccess );
|
||
MmEnablePageFaultClustering(SavedState);
|
||
SavedState = 0;
|
||
|
||
//
|
||
// Now that some data (maybe zeros) is locked in memory and
|
||
// set dirty, it is safe, and necessary for us to advance
|
||
// valid data goal, so that we will not subsequently ask
|
||
// for a zero page. Note if we are extending valid data,
|
||
// our caller has the file exclusive.
|
||
//
|
||
|
||
if (BeyondLastByte.QuadPart > SharedCacheMap->ValidDataGoal.QuadPart) {
|
||
SharedCacheMap->ValidDataGoal = BeyondLastByte;
|
||
}
|
||
|
||
//
|
||
// Unmap the data now, now that the pages are locked down.
|
||
//
|
||
|
||
CcFreeVirtualAddress( Vacb );
|
||
Vacb = NULL;
|
||
|
||
//
|
||
// Now link the Mdl into the caller's chain
|
||
//
|
||
|
||
if ( *MdlChain == NULL ) {
|
||
*MdlChain = Mdl;
|
||
} else {
|
||
MdlTemp = CONTAINING_RECORD( *MdlChain, MDL, Next );
|
||
while (MdlTemp->Next != NULL) {
|
||
MdlTemp = MdlTemp->Next;
|
||
}
|
||
MdlTemp->Next = Mdl;
|
||
}
|
||
|
||
//
|
||
// Assume we did not get all the data we wanted, and set FOffset
|
||
// to the end of the returned data.
|
||
//
|
||
|
||
FOffset = BeyondLastByte;
|
||
|
||
//
|
||
// Update number of bytes transferred.
|
||
//
|
||
|
||
Information += ReceivedLength;
|
||
|
||
//
|
||
// Calculate length left to transfer.
|
||
//
|
||
|
||
Length -= ReceivedLength;
|
||
}
|
||
}
|
||
finally {
|
||
|
||
if (AbnormalTermination()) {
|
||
|
||
if (SavedState != 0) {
|
||
MmEnablePageFaultClustering(SavedState);
|
||
}
|
||
|
||
if (Vacb != NULL) {
|
||
CcFreeVirtualAddress( Vacb );
|
||
}
|
||
|
||
//
|
||
// Otherwise loop to deallocate the Mdls
|
||
//
|
||
|
||
FOffset = *FileOffset;
|
||
while (*MdlChain != NULL) {
|
||
MdlTemp = (*MdlChain)->Next;
|
||
|
||
DebugTrace( 0, mm, "MmUnlockPages/IoFreeMdl:\n", 0 );
|
||
DebugTrace( 0, mm, " Mdl = %08lx\n", *MdlChain );
|
||
|
||
MmUnlockPages( *MdlChain );
|
||
|
||
//
|
||
// Extract the File Offset for this part of the transfer, and
|
||
// tell the lazy writer to write these pages, since we have
|
||
// marked them dirty. Ignore the only exception (allocation
|
||
// error), and console ourselves for having tried.
|
||
//
|
||
|
||
//
|
||
// try-except does not work on MS compiler. We can accept
|
||
// leaving a few good pages dirty...
|
||
//
|
||
// try {
|
||
// CcSetDirtyInMask( SharedCacheMap, &FOffset, (*MdlChain)->ByteCount );
|
||
// } except( CcCopyReadExceptionFilter( GetExceptionInformation(), &ExceptionCode ) ) {
|
||
// NOTHING;
|
||
// }
|
||
|
||
FOffset.QuadPart = FOffset.QuadPart + (LONGLONG)((*MdlChain)->ByteCount);
|
||
|
||
IoFreeMdl( *MdlChain );
|
||
|
||
*MdlChain = MdlTemp;
|
||
}
|
||
|
||
DebugTrace(-1, me, "CcPrepareMdlWrite -> Unwinding\n", 0 );
|
||
}
|
||
else {
|
||
|
||
IoStatus->Status = STATUS_SUCCESS;
|
||
IoStatus->Information = Information;
|
||
|
||
//
|
||
// Make sure the SharedCacheMap does not go away while
|
||
// the Mdl write is in progress. We decrment below.
|
||
//
|
||
|
||
ExAcquireFastLock( &CcMasterSpinLock, &OldIrql );
|
||
SharedCacheMap->OpenCount += 1;
|
||
ExReleaseFastLock( &CcMasterSpinLock, OldIrql );
|
||
}
|
||
}
|
||
|
||
DebugTrace( 0, me, " <MdlChain = %08lx\n", *MdlChain );
|
||
DebugTrace(-1, me, "CcPrepareMdlWrite -> VOID\n", 0 );
|
||
|
||
return;
|
||
}
|
||
|
||
|
||
//
|
||
// First we have the old routine which checks for an entry in the FastIo vector.
|
||
// This routine becomes obsolete for every component that compiles with the new
|
||
// definition of FsRtlMdlWriteComplete in fsrtl.h.
|
||
//
|
||
|
||
VOID
|
||
CcMdlWriteComplete (
|
||
IN PFILE_OBJECT FileObject,
|
||
IN PLARGE_INTEGER FileOffset,
|
||
IN PMDL MdlChain
|
||
)
|
||
|
||
{
|
||
PDEVICE_OBJECT DeviceObject;
|
||
PFAST_IO_DISPATCH FastIoDispatch;
|
||
|
||
DeviceObject = IoGetRelatedDeviceObject( FileObject );
|
||
FastIoDispatch = DeviceObject->DriverObject->FastIoDispatch;
|
||
|
||
if ((FastIoDispatch != NULL) &&
|
||
(FastIoDispatch->SizeOfFastIoDispatch > FIELD_OFFSET(FAST_IO_DISPATCH, MdlWriteComplete)) &&
|
||
(FastIoDispatch->MdlWriteComplete != NULL)) {
|
||
|
||
FastIoDispatch->MdlWriteComplete( FileObject, FileOffset, MdlChain, DeviceObject );
|
||
|
||
} else {
|
||
CcMdlWriteComplete2( FileObject, FileOffset, MdlChain );
|
||
}
|
||
}
|
||
|
||
VOID
|
||
CcMdlWriteComplete2 (
|
||
IN PFILE_OBJECT FileObject,
|
||
IN PLARGE_INTEGER FileOffset,
|
||
IN PMDL MdlChain
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine must be called at IPL0 after a call to CcPrepareMdlWrite.
|
||
The caller supplies the ActualLength of data that it actually wrote
|
||
into the buffer, which may be less than or equal to the Length specified
|
||
in CcPrepareMdlWrite.
|
||
|
||
This call does the following:
|
||
|
||
Makes sure the data up to ActualLength eventually gets written.
|
||
If WriteThrough is FALSE, the data will not be written immediately.
|
||
If WriteThrough is TRUE, then the data is written synchronously.
|
||
|
||
Unmaps the pages (if mapped), unlocks them and deletes the MdlChain
|
||
|
||
Arguments:
|
||
|
||
FileObject - Pointer to the file object for a file which was
|
||
opened with NO_INTERMEDIATE_BUFFERING clear, i.e., for
|
||
which CcInitializeCacheMap was called by the file system.
|
||
|
||
FileOffset - Original file offset read above.
|
||
|
||
MdlChain - same as returned from corresponding call to CcPrepareMdlWrite.
|
||
|
||
Return Value:
|
||
|
||
None
|
||
|
||
--*/
|
||
|
||
{
|
||
PMDL MdlNext;
|
||
PSHARED_CACHE_MAP SharedCacheMap;
|
||
LARGE_INTEGER FOffset;
|
||
IO_STATUS_BLOCK IoStatus;
|
||
KIRQL OldIrql;
|
||
NTSTATUS StatusToRaise = STATUS_SUCCESS;
|
||
|
||
DebugTrace(+1, me, "CcMdlWriteComplete\n", 0 );
|
||
DebugTrace( 0, me, " FileObject = %08lx\n", FileObject );
|
||
DebugTrace( 0, me, " MdlChain = %08lx\n", MdlChain );
|
||
|
||
SharedCacheMap = FileObject->SectionObjectPointer->SharedCacheMap;
|
||
|
||
//
|
||
// Deallocate the Mdls
|
||
//
|
||
|
||
FOffset.QuadPart = *(LONGLONG UNALIGNED *)FileOffset;
|
||
while (MdlChain != NULL) {
|
||
|
||
MdlNext = MdlChain->Next;
|
||
|
||
DebugTrace( 0, mm, "MmUnlockPages/IoFreeMdl:\n", 0 );
|
||
DebugTrace( 0, mm, " Mdl = %08lx\n", MdlChain );
|
||
|
||
//
|
||
// Now clear the dirty bits in the Pte and set them in the
|
||
// Pfn.
|
||
//
|
||
|
||
MmUnlockPages( MdlChain );
|
||
|
||
//
|
||
// Extract the File Offset for this part of the transfer.
|
||
//
|
||
|
||
if (FlagOn(FileObject->Flags, FO_WRITE_THROUGH)) {
|
||
|
||
MmFlushSection ( FileObject->SectionObjectPointer,
|
||
&FOffset,
|
||
MdlChain->ByteCount,
|
||
&IoStatus,
|
||
TRUE );
|
||
|
||
//
|
||
// If we got an I/O error, remember it.
|
||
//
|
||
|
||
if (!NT_SUCCESS(IoStatus.Status)) {
|
||
StatusToRaise = IoStatus.Status;
|
||
}
|
||
|
||
} else {
|
||
|
||
NTSTATUS ExceptionCode;
|
||
|
||
//
|
||
// Ignore the only exception (allocation error), and console
|
||
// ourselves for having tried.
|
||
//
|
||
|
||
try {
|
||
CcSetDirtyInMask( SharedCacheMap, &FOffset, MdlChain->ByteCount );
|
||
} except( CcCopyReadExceptionFilter( GetExceptionInformation(), &ExceptionCode ) ) {
|
||
StatusToRaise = STATUS_INSUFFICIENT_RESOURCES;
|
||
}
|
||
}
|
||
|
||
FOffset.QuadPart = FOffset.QuadPart + (LONGLONG)(MdlChain->ByteCount);
|
||
|
||
IoFreeMdl( MdlChain );
|
||
|
||
MdlChain = MdlNext;
|
||
}
|
||
|
||
//
|
||
// Now release our open count.
|
||
//
|
||
|
||
ExAcquireSpinLock( &CcMasterSpinLock, &OldIrql );
|
||
|
||
SharedCacheMap->OpenCount -= 1;
|
||
|
||
if ((SharedCacheMap->OpenCount == 0) &&
|
||
!FlagOn(SharedCacheMap->Flags, WRITE_QUEUED) &&
|
||
(SharedCacheMap->DirtyPages == 0)) {
|
||
|
||
//
|
||
// Move to the dirty list.
|
||
//
|
||
|
||
RemoveEntryList( &SharedCacheMap->SharedCacheMapLinks );
|
||
InsertTailList( &CcDirtySharedCacheMapList.SharedCacheMapLinks,
|
||
&SharedCacheMap->SharedCacheMapLinks );
|
||
|
||
//
|
||
// Make sure the Lazy Writer will wake up, because we
|
||
// want him to delete this SharedCacheMap.
|
||
//
|
||
|
||
LazyWriter.OtherWork = TRUE;
|
||
if (!LazyWriter.ScanActive) {
|
||
CcScheduleLazyWriteScan();
|
||
}
|
||
}
|
||
|
||
ExReleaseSpinLock( &CcMasterSpinLock, OldIrql );
|
||
|
||
//
|
||
// If we got an I/O error, raise it now.
|
||
//
|
||
|
||
if (!NT_SUCCESS(StatusToRaise)) {
|
||
FsRtlNormalizeNtstatus( StatusToRaise,
|
||
STATUS_UNEXPECTED_IO_ERROR );
|
||
}
|
||
|
||
DebugTrace(-1, me, "CcMdlWriteComplete -> TRUE\n", 0 );
|
||
|
||
return;
|
||
}
|
||
|
||
|
||
|