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Windows2000/private/ntos/udfs/allocsup.c
Microsoft 45f4a58588 First commit
2020-09-30 17:12:32 +02:00

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/*++
Copyright (c) 1996 Microsoft Corporation
Module Name:
AllocSup.c
Abstract:
This module implements mappings to physical blocks on UDF media. The basic
structure used here is the Pcb, which contains lookup information for each
partition reference in the volume.
Author:
Dan Lovinger [DanLo] 5-Sep-1996
Revision History:
--*/
#include "UdfProcs.h"
// The Bug check file id for this module
#define BugCheckFileId (UDFS_BUG_CHECK_ALLOCSUP)
// The local debug trace level
#define Dbg (UDFS_DEBUG_LEVEL_ALLOCSUP)
// Local support routines.
PPCB
UdfCreatePcb (
IN ULONG NumberOfPartitions
);
NTSTATUS
UdfLoadSparingTables(
PIRP_CONTEXT IrpContext,
PVCB Vcb,
PPCB Pcb,
ULONG Reference
);
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, UdfAddToPcb)
#pragma alloc_text(PAGE, UdfCompletePcb)
#pragma alloc_text(PAGE, UdfCreatePcb)
#pragma alloc_text(PAGE, UdfDeletePcb)
#pragma alloc_text(PAGE, UdfEquivalentPcb)
#pragma alloc_text(PAGE, UdfInitializePcb)
#pragma alloc_text(PAGE, UdfLookupAllocation)
#pragma alloc_text(PAGE, UdfLookupMetaVsnOfExtent)
#pragma alloc_text(PAGE, UdfLookupPsnOfExtent)
#endif
BOOLEAN
UdfLookupAllocation (
IN PIRP_CONTEXT IrpContext,
IN PFCB Fcb,
IN LONGLONG FileOffset,
OUT PLONGLONG DiskOffset,
OUT PULONG ByteCount
)
/*++
Routine Description:
This routine looks through the mapping information for the file
to find the logical diskoffset and number of bytes at that offset.
This routine assumes we are looking up a valid range in the file. If
a mapping does not exist,
Arguments:
Fcb - Fcb representing this stream.
FileOffset - Lookup the allocation beginning at this point.
DiskOffset - Address to store the logical disk offset.
ByteCount - Address to store the number of contiguous bytes beginning
at DiskOffset above.
Return Value:
BOOLEAN - whether the extent is unrecorded data
--*/
{
PVCB Vcb;
BOOLEAN Recorded = TRUE;
BOOLEAN Result;
LARGE_INTEGER LocalPsn;
LARGE_INTEGER LocalSectorCount;
PAGED_CODE();
// Check inputs
ASSERT_IRP_CONTEXT( IrpContext );
ASSERT_FCB( Fcb );
// We will never be looking up the allocations of embedded objects.
ASSERT( !FlagOn( Fcb->FcbState, FCB_STATE_EMBEDDED_DATA ));
Vcb = Fcb->Vcb;
LocalPsn.QuadPart = LocalSectorCount.QuadPart = 0;
// Lookup the entry containing this file offset.
if (FlagOn( Fcb->FcbState, FCB_STATE_VMCB_MAPPING )) {
// Map this offset into the metadata stream.
ASSERT( SectorOffset( Vcb, FileOffset ) == 0 );
Result = UdfVmcbVbnToLbn( &Vcb->Vmcb,
SectorsFromBytes( Vcb, FileOffset ),
&LocalPsn.LowPart,
&LocalSectorCount.LowPart );
ASSERT( Result );
} else {
// Map this offset in a regular stream.
ASSERT( FlagOn( Fcb->FcbState, FCB_STATE_MCB_INITIALIZED ));
Result = FsRtlLookupLargeMcbEntry( &Fcb->Mcb,
LlSectorsFromBytes( Vcb, FileOffset ),
&LocalPsn.QuadPart,
&LocalSectorCount.QuadPart,
NULL,
NULL,
NULL );
}
// If within the Mcb then we use the data out of this entry and are nearly done.
if (Result) {
if ( LocalPsn.QuadPart == -1 ) {
// Regular files can have holey allocations which represent unrecorded extents. For
// such extents which are sandwiched in between recorded extents of the file, the Mcb
// package tells us that it found a valid mapping but that it doesn't correspond to
// any extents on the media yet. In this case, simply fake the disk offset. The
// returned sector count is accurate.
*DiskOffset = 0;
Recorded = FALSE;
} else {
// Now mimic the effects of physical sector sparing. This may shrink the size of the
// returned run if sparing interrupted the extent on disc.
ASSERT( LocalPsn.HighPart == 0 );
if (Vcb->Pcb->SparingMcb) {
LONGLONG SparingPsn;
LONGLONG SparingSectorCount;
if (FsRtlLookupLargeMcbEntry( Vcb->Pcb->SparingMcb,
LocalPsn.LowPart,
&SparingPsn,
&SparingSectorCount,
NULL,
NULL,
NULL )) {
// Only emit noise if we will really change anything as a result
// of the sparing table.
if (SparingPsn != -1 ||
SparingSectorCount < LocalSectorCount.QuadPart) {
DebugTrace(( 0, Dbg, "UdfLookupAllocation, spared [%x, +%x) onto [%x, +%x)\n",
LocalPsn.LowPart,
LocalSectorCount.LowPart,
(ULONG) SparingPsn,
(ULONG) SparingSectorCount ));
}
// If we did not land in a hole, map the sector.
if (SparingPsn != -1) {
LocalPsn.QuadPart = SparingPsn;
}
// The returned sector count now reduces the previous sector count.
// If we landed in a hole, this indicates that the trailing edge of
// the extent is spared, if not this indicates that the leading
// edge is spared.
if (SparingSectorCount < LocalSectorCount.QuadPart) {
LocalSectorCount.QuadPart = SparingSectorCount;
}
}
}
*DiskOffset = LlBytesFromSectors( Vcb, LocalPsn.QuadPart ) + SectorOffset( Vcb, FileOffset );
// Now we can apply method 2 fixups, which will again interrupt the size of the extent.
if (FlagOn( Vcb->VcbState, VCB_STATE_METHOD_2_FIXUP )) {
LARGE_INTEGER SectorsToRunout;
SectorsToRunout.QuadPart= UdfMethod2NextRunoutInSectors( Vcb, *DiskOffset );
if (SectorsToRunout.QuadPart < LocalSectorCount.QuadPart) {
LocalSectorCount.QuadPart = SectorsToRunout.QuadPart;
}
*DiskOffset = UdfMethod2TransformByteOffset( Vcb, *DiskOffset );
}
}
} else {
// We know that prior to this call the system has restricted IO to points within the
// the file data. Since we failed to find a mapping this is an unrecorded extent at
// the end of the file, so just conjure up a proper representation.
ASSERT( FileOffset < Fcb->FileSize.QuadPart );
*DiskOffset = 0;
LocalSectorCount.QuadPart = LlSectorsFromBytes( Vcb, Fcb->FileSize.QuadPart ) -
LlSectorsFromBytes( Vcb, FileOffset ) +
1;
Recorded = FALSE;
}
// Restrict to MAXULONG bytes of allocation
if (LocalSectorCount.QuadPart > SectorsFromBytes( Vcb, MAXULONG )) {
*ByteCount = MAXULONG;
} else {
*ByteCount = BytesFromSectors( Vcb, LocalSectorCount.LowPart );
}
*ByteCount -= SectorOffset( Vcb, FileOffset );
return Recorded;
}
VOID
UdfDeletePcb (
IN PPCB Pcb
)
/*++
Routine Description:
This routine deallocates a Pcb and all ancilliary structures.
Arguments:
Pcb - Pcb being deleted
Return Value:
None
--*/
{
PPARTITION Partition;
if (Pcb->SparingMcb) {
FsRtlUninitializeLargeMcb( Pcb->SparingMcb );
UdfFreePool( &Pcb->SparingMcb );
}
for (Partition = Pcb->Partition;
Partition < &Pcb->Partition[Pcb->Partitions];
Partition++) {
switch (Partition->Type) {
case Physical:
UdfFreePool( &Partition->Physical.PartitionDescriptor );
UdfFreePool( &Partition->Physical.SparingMap );
break;
case Virtual:
case Uninitialized:
break;
default:
ASSERT( FALSE );
break;
}
}
ExFreePool( Pcb );
}
NTSTATUS
UdfInitializePcb (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN OUT PPCB *Pcb,
IN PNSR_LVOL LVD
)
/*++
Routine Description:
This routine walks through the partition map of a Logical Volume Descriptor
and builds an intializing Pcb from it. The Pcb will be ready to be used
in searching for the partition descriptors of a volume.
Arguments:
Vcb - The volume this Pcb will pertain to
Pcb - Caller's pointer to the Pcb
LVD - The Logical Volume Descriptor being used
Return Value:
STATUS_SUCCESS if the partition map is good and the Pcb is built
STATUS_DISK_CORRUPT_ERROR if corrupt maps are found
STATUS_UNRECOGNIZED_VOLUME if noncompliant maps are found
--*/
{
PPARTMAP_UDF_GENERIC Map;
PPARTITION Partition;
BOOLEAN Found;
PAGED_CODE();
// Check the input parameters
ASSERT_OPTIONAL_PCB( *Pcb );
DebugTrace(( +1, Dbg,
"UdfInitializePcb, Lvd %08x\n",
LVD ));
// Delete a pre-existing (partially initialized from a failed
// crawl of a VDS) Pcb.
if (*Pcb != NULL) {
UdfDeletePcb( *Pcb );
*Pcb = NULL;
}
*Pcb = UdfCreatePcb( LVD->MapTableCount );
// Walk the table of partition maps intializing the Pcb for the descriptor
// initialization pass.
for (Map = (PPARTMAP_UDF_GENERIC) LVD->MapTable,
Partition = (*Pcb)->Partition;
Partition < &(*Pcb)->Partition[(*Pcb)->Partitions];
Map = Add2Ptr( Map, Map->Length, PPARTMAP_UDF_GENERIC ),
Partition++) {
// Now check that this LVD can actually contain this map entry. First check that
// the descriptor can contain the first few fields, then check that it can hold
// all of the bytes claimed by the descriptor.
if (Add2Ptr( Map, sizeof( PARTMAP_GENERIC ), PCHAR ) > Add2Ptr( LVD, ISONsrLvolSize( LVD ), PCHAR ) ||
Add2Ptr( Map, Map->Length, PCHAR ) > Add2Ptr( LVD, ISONsrLvolSize( LVD ), PCHAR )) {
DebugTrace(( 0, Dbg,
"UdfInitializePcb, map at +%04x beyond Lvd size %04x\n",
(PCHAR) Map - (PCHAR) LVD,
ISONsrLvolSize( LVD )));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
// Now load up this map entry.
switch (Map->Type) {
case PARTMAP_TYPE_PHYSICAL:
{
PPARTMAP_PHYSICAL MapPhysical = (PPARTMAP_PHYSICAL) Map;
// Type 1 - Physical Partition
DebugTrace(( 0, Dbg,
"UdfInitializePcb, map reference %02x is Physical (Partition # %08x)\n",
(Partition - (*Pcb)->Partition)/sizeof(PARTITION),
MapPhysical->Partition ));
// It must be the case that the volume the partition is on is the first
// one since we only do single disc UDF. This will have already been
// checked by the caller.
if (MapPhysical->VolSetSeq > 1) {
DebugTrace(( 0, Dbg,
"UdfInitializePcb, ... but physical partition resides on volume set volume # %08x (> 1)!\n",
MapPhysical->VolSetSeq ));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
SetFlag( (*Pcb)->Flags, PCB_FLAG_PHYSICAL_PARTITION );
Partition->Type = Physical;
Partition->Physical.PartitionNumber = MapPhysical->Partition;
}
break;
case PARTMAP_TYPE_PROXY:
// Type 2 - a Proxy Partition, something not explicitly physical.
DebugTrace(( 0, Dbg,
"UdfInitializePcb, map reference %02x is a proxy\n",
(Partition - (*Pcb)->Partition)/sizeof(PARTITION)));
// Handle the various types of proxy partitions we recognize
if (UdfDomainIdentifierContained( &Map->PartID,
&UdfVirtualPartitionDomainIdentifier,
UDF_VERSION_150,
UDF_VERSION_RECOGNIZED )) {
{
PPARTMAP_VIRTUAL MapVirtual = (PPARTMAP_VIRTUAL) Map;
// Only one of these guys can exist, since there can be only one VAT per media surface.
if (FlagOn( (*Pcb)->Flags, PCB_FLAG_VIRTUAL_PARTITION )) {
DebugTrace(( 0, Dbg,
"UdfInitializePcb, ... but this is a second virtual partition!?!!\n" ));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_UNCRECOGNIZED_VOLUME\n" ));
return STATUS_UNRECOGNIZED_VOLUME;
}
DebugTrace(( 0, Dbg,
"UdfInitializePcb, ... Virtual (Partition # %08x)\n",
MapVirtual->Partition ));
SetFlag( (*Pcb)->Flags, PCB_FLAG_VIRTUAL_PARTITION );
Partition->Type = Virtual;
// We will convert the partition number to a partition reference
// before returning.
Partition->Virtual.RelatedReference = MapVirtual->Partition;
}
} else if (UdfDomainIdentifierContained( &Map->PartID,
&UdfSparablePartitionDomainIdentifier,
UDF_VERSION_150,
UDF_VERSION_RECOGNIZED )) {
{
NTSTATUS Status;
PPARTMAP_SPARABLE MapSparable = (PPARTMAP_SPARABLE) Map;
// It must be the case that the volume the partition is on is the first
// one since we only do single disc UDF. This will have already been
// checked by the caller.
if (MapSparable->VolSetSeq > 1) {
DebugTrace(( 0, Dbg,
"UdfInitializePcb, ... but sparable partition resides on volume set volume # %08x (> 1)!\n",
MapSparable->VolSetSeq ));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
DebugTrace(( 0, Dbg,
"UdfInitializePcb, ... Sparable (Partition # %08x)\n",
MapSparable->Partition ));
// We pretend that sparable partitions are basically the same as
// physical partitions. Since we are not r/w (and will never be
// on media that requires host-based sparing in any case), this
// is a good simplification.
SetFlag( (*Pcb)->Flags, PCB_FLAG_SPARABLE_PARTITION );
Partition->Type = Physical;
Partition->Physical.PartitionNumber = MapSparable->Partition;
// Save this map for use when the partition descriptor is found.
// We can't load the sparing table at this time because we have
// to turn the Lbn->Psn mapping into a Psn->Psn mapping. UDF
// believes that the way sparing will be used in concert with
// the Lbn->Psn mapping engine (like UdfLookupPsnOfExtent).
// Unfortunately, this would be a bit painful at this time.
// The users of UdfLookupPsnOfExtent would need to iterate
// over a new interface (not so bad) but the Vmcb package
// would need to be turned inside out so that it didn't do
// the page-filling alignment of blocks in the metadata
// stream - instead, UdfLookupMetaVsnOfExtent would need to
// do this itself. I choose to lay the sparing engine into
// the read path and raw sector read engine instead.
Partition->Physical.SparingMap = FsRtlAllocatePoolWithTag( PagedPool,
sizeof(PARTMAP_SPARABLE),
TAG_NSR_FSD);
RtlCopyMemory( Partition->Physical.SparingMap,
MapSparable,
sizeof(PARTMAP_SPARABLE));
}
} else {
DebugTrace(( 0, Dbg,
"UdfInitializePcb, ... but we don't recognize this proxy!\n" ));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_UNRECOGNIZED_VOLUME\n" ));
return STATUS_UNRECOGNIZED_VOLUME;
}
break;
default:
DebugTrace(( 0, Dbg,
"UdfInitializePcb, map reference %02x is of unknown type %02x\n",
Map->Type ));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_UNRECOGNIZED_VOLUME\n" ));
return STATUS_UNRECOGNIZED_VOLUME;
break;
}
}
if (!FlagOn( (*Pcb)->Flags, PCB_FLAG_PHYSICAL_PARTITION | PCB_FLAG_SPARABLE_PARTITION )) {
DebugTrace(( 0, Dbg,
"UdfInitializePcb, no physical partition seen on this logical volume!\n" ));
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_UNRECOGNIZED_VOLUME\n" ));
return STATUS_UNRECOGNIZED_VOLUME;
}
if (FlagOn( (*Pcb)->Flags, PCB_FLAG_VIRTUAL_PARTITION )) {
PPARTITION Host;
// Confirm the validity of any type 2 virtual maps on this volume
// and convert partition numbers to partition references that will
// immediately index an element of the Pcb.
for (Partition = (*Pcb)->Partition;
Partition < &(*Pcb)->Partition[(*Pcb)->Partitions];
Partition++) {
if (Partition->Type == Virtual) {
// Go find the partition this thing is talking about
Found = FALSE;
for (Host = (*Pcb)->Partition;
Host < &(*Pcb)->Partition[(*Pcb)->Partitions];
Host++) {
if (Host->Type == Physical &&
Host->Physical.PartitionNumber ==
Partition->Virtual.RelatedReference) {
Partition->Virtual.RelatedReference =
(USHORT)(Host - (*Pcb)->Partition)/sizeof(PARTITION);
Found = TRUE;
break;
}
}
// Failure to find a physical partition for this virtual guy
// is not a good sign.
if (!Found) {
return STATUS_DISK_CORRUPT_ERROR;
}
}
}
}
DebugTrace(( -1, Dbg,
"UdfInitializePcb -> STATUS_SUCCESS\n" ));
return STATUS_SUCCESS;
}
VOID
UdfAddToPcb (
IN PPCB Pcb,
IN PNSR_PART PartitionDescriptor
)
/*++
Routine Description:
This routine possibly adds a partition descriptor into a Pcb if it
turns out to be of higher precendence than a descriptor already
present. Used in building a Pcb already initialized in preperation
for UdfCompletePcb.
Arguments:
Vcb - Vcb of the volume the Pcb describes
Pcb - Pcb being filled in
Return Value:
None. An old partition descriptor may be returned in the input field.
--*/
{
USHORT Reference;
PAGED_CODE();
// Check inputs
ASSERT_PCB( Pcb );
ASSERT( PartitionDescriptor );
for (Reference = 0;
Reference < Pcb->Partitions;
Reference++) {
DebugTrace(( 0, Dbg, "UdfAddToPcb, considering partition reference %d (type %d)\n", (ULONG)Reference, Pcb->Partition[Reference].Type));
switch (Pcb->Partition[Reference].Type) {
case Physical:
// Now possibly store this descriptor in the Pcb if it is
// the partition number for this partition reference.
if (Pcb->Partition[Reference].Physical.PartitionNumber == PartitionDescriptor->Number) {
// It seems to be legal (if questionable) for multiple partition maps to reference
// the same partition descriptor. So we make a copy of the descriptor for each
// referencing partitionmap to make life easier when it comes to freeing it.
UdfStoreVolumeDescriptorIfPrevailing( (PNSR_VD_GENERIC *) &Pcb->Partition[Reference].Physical.PartitionDescriptor,
(PNSR_VD_GENERIC) PartitionDescriptor );
}
break;
case Virtual:
break;
default:
ASSERT(FALSE);
break;
}
}
}
NTSTATUS
UdfCompletePcb (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN PPCB Pcb
)
/*++
Routine Description:
This routine completes initialization of a Pcb which has been filled
in with partition descriptors. Initialization-time data such as the
physical partition descriptors will be returned to the system.
Arguments:
Vcb - Vcb of the volume the Pcb describes
Pcb - Pcb being completed
Return Value:
NTSTATUS according to whether intialization completion was succesful
--*/
{
ULONG Reference;
NTSTATUS Status;
PAGED_CODE();
// Check inputs
ASSERT_IRP_CONTEXT( IrpContext );
ASSERT_VCB( Vcb );
ASSERT_PCB( Pcb );
DebugTrace(( +1, Dbg, "UdfCompletePcb, Vcb %08x Pcb %08x\n", Vcb, Pcb ));
// Complete intialization all physical partitions
for (Reference = 0;
Reference < Pcb->Partitions;
Reference++) {
DebugTrace(( 0, Dbg, "UdfCompletePcb, Examining Ref %u (type %u)!\n", Reference, Pcb->Partition[Reference].Type));
switch (Pcb->Partition[Reference].Type) {
case Physical:
if (Pcb->Partition[Reference].Physical.PartitionDescriptor == NULL) {
DebugTrace(( 0, Dbg,
"UdfCompletePcb, ... but didn't find Partition# %u!\n",
Pcb->Partition[Reference].Physical.PartitionNumber ));
DebugTrace(( -1, Dbg, "UdfCompletePcb -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
Pcb->Partition[Reference].Physical.Start =
Pcb->Partition[Reference].Physical.PartitionDescriptor->Start;
Pcb->Partition[Reference].Physical.Length =
Pcb->Partition[Reference].Physical.PartitionDescriptor->Length;
// Retrieve the sparing information at this point if appropriate.
// We have to do this when we can map logical -> physical blocks.
if (Pcb->Partition[Reference].Physical.SparingMap) {
Status = UdfLoadSparingTables( IrpContext,
Vcb,
Pcb,
Reference );
if (!NT_SUCCESS( Status )) {
DebugTrace(( -1, Dbg,
"UdfCompletePcb -> %08x\n", Status ));
return Status;
}
}
// We will not need the descriptor or sparing map anymore, so drop them.
UdfFreePool( &Pcb->Partition[Reference].Physical.PartitionDescriptor );
UdfFreePool( &Pcb->Partition[Reference].Physical.SparingMap );
break;
case Virtual:
break;
default:
ASSERT(FALSE);
break;
}
}
DebugTrace(( -1, Dbg, "UdfCompletePcb -> STATUS_SUCCESS\n" ));
return STATUS_SUCCESS;
}
BOOLEAN
UdfEquivalentPcb (
IN PIRP_CONTEXT IrpContext,
IN PPCB Pcb1,
IN PPCB Pcb2
)
/*++
Routine Description:
This routine compares two completed Pcbs to see if they appear equivalent.
Arguments:
Pcb1 - Pcb being compared
Pcb2 - Pcb being compared
Return Value:
BOOLEAN according to whether they are equivalent (TRUE, else FALSE)
--*/
{
ULONG Index;
PAGED_CODE();
// Check input.
ASSERT_IRP_CONTEXT( IrpContext );
if (Pcb1->Partitions != Pcb2->Partitions) {
return FALSE;
}
for (Index = 0;
Index < Pcb1->Partitions;
Index++) {
// First check that the partitions are of the same type.
if (Pcb1->Partition[Index].Type != Pcb2->Partition[Index].Type) {
return FALSE;
}
// Now the map content must be the same ...
switch (Pcb1->Partition[Index].Type) {
case Physical:
if (Pcb1->Partition[Index].Physical.PartitionNumber != Pcb2->Partition[Index].Physical.PartitionNumber ||
Pcb1->Partition[Index].Physical.Length != Pcb2->Partition[Index].Physical.Length ||
Pcb1->Partition[Index].Physical.Start != Pcb2->Partition[Index].Physical.Start) {
return FALSE;
}
break;
case Virtual:
if (Pcb1->Partition[Index].Virtual.RelatedReference != Pcb2->Partition[Index].Virtual.RelatedReference) {
return FALSE;
}
break;
default:
ASSERT( FALSE);
return FALSE;
break;
}
}
// All map elements were equivalent.
return TRUE;
}
ULONG
UdfLookupPsnOfExtent (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN USHORT Reference,
IN ULONG Lbn,
IN ULONG Len
)
/*++
Routine Description:
This routine maps the input logical block extent on a given partition to
a starting physical sector. It doubles as a bounds checker - if the routine
does not raise, the caller is guaranteed that the extent lies within the
partition.
Arguments:
Vcb - Vcb of logical volume
Reference - Partition reference to use in the mapping
Lbn - Logical block number
Len - Length of extent in bytes
Return Value:
ULONG physical sector number
--*/
{
PPCB Pcb = Vcb->Pcb;
ULONG Psn;
PBCB Bcb;
LARGE_INTEGER Offset;
PULONG MappedLbn;
PAGED_CODE();
// Check inputs
ASSERT_IRP_CONTEXT( IrpContext );
ASSERT_VCB( Vcb );
ASSERT_PCB( Pcb );
DebugTrace(( +1, Dbg, "UdfLookupPsnOfExtent, [%04x/%08x, +%08x)\n", Reference, Lbn, Len ));
if (Reference < Pcb->Partitions) {
while (TRUE) {
switch (Pcb->Partition[Reference].Type) {
case Physical:
// Check that the input extent lies inside the partition. Calculate the
// Lbn of the last block and see that it is interior.
if (SectorsFromBlocks( Vcb, Lbn ) + SectorsFromBytes( Vcb, Len ) >
Pcb->Partition[Reference].Physical.Length) {
goto NoGood;
}
Psn = Pcb->Partition[Reference].Physical.Start + SectorsFromBlocks( Vcb, Lbn );
DebugTrace(( -1, Dbg, "UdfLookupPsnOfExtent -> %08x\n", Psn ));
return Psn;
case Virtual:
// Bounds check. Per UDF 2.00 2.3.10 and implied in UDF 1.50, virtual
// extent lengths cannot be greater than one block in size.
if (Lbn + BlocksFromBytes( Vcb, Len ) > Pcb->Partition[Reference].Virtual.Length ||
Len > BlockSize( Vcb )) {
goto NoGood;
}
try {
// Calculate the location of the mapping element in the VAT
// and retrieve.
Offset.QuadPart = Lbn * sizeof(ULONG);
CcMapData( Vcb->VatFcb->FileObject,
&Offset,
sizeof(ULONG),
TRUE,
&Bcb,
&MappedLbn );
// Now rewrite the inputs in terms of the virtual mapping. We
// will reloop to perform the logical -> physical mapping.
DebugTrace(( 0, Dbg,
"UdfLookupPsnOfExtent, Mapping V %04x/%08x -> L %04x/%08x\n",
Reference,
Lbn,
Pcb->Partition[Reference].Virtual.RelatedReference,
*MappedLbn ));
Lbn = *MappedLbn;
Reference = Pcb->Partition[Reference].Virtual.RelatedReference;
} finally {
DebugUnwind( UdfLookupPsnOfExtent );
UdfUnpinData( IrpContext, &Bcb );
}
// An Lbn of ~0 in the VAT is defined to indicate that the sector is unused,
// so we should never see such a thing.
if (Lbn == ~0) {
goto NoGood;
}
break;
default:
ASSERT(FALSE);
break;
}
}
}
NoGood:
// Some people have misinterpreted a partition number to equal a
// partition reference, or perhaps this is just corrupt media.
UdfRaiseStatus( IrpContext, STATUS_FILE_CORRUPT_ERROR );
}
ULONG
UdfLookupMetaVsnOfExtent (
IN PIRP_CONTEXT IrpContext,
IN PVCB Vcb,
IN USHORT Reference,
IN ULONG Lbn,
IN ULONG Len,
IN BOOLEAN ExactEnd
)
/*++
Routine Description:
This routine maps the input logical block extent on a given partition to
a starting virtual block in the metadata stream. If a mapping does not
exist, one will be created and the metadata stream extended.
Arguments:
Vcb - Vcb of logical volume
Reference - Partition reference to use in the mapping
Lbn - Logical block number
Len - Length of extent in bytes
ExactEnd - Indicates the extension policy if these blocks are not mapped.
Return Value:
ULONG virtual sector number
Raised status if the Lbn extent is split across multiple Vbn extents.
--*/
{
ULONG Vsn;
ULONG Psn;
ULONG SectorCount;
BOOLEAN Result;
BOOLEAN UnwindExtension = FALSE;
LONGLONG UnwindAllocationSize;
PFCB Fcb = NULL;
// Check inputs
ASSERT_IRP_CONTEXT( IrpContext );
ASSERT_VCB( Vcb );
// The extent must be an integral number of logical blocks in length.
if (Len == 0 || BlockOffset( Vcb, Len )) {
UdfRaiseStatus( IrpContext, STATUS_FILE_CORRUPT_ERROR );
}
// Get the physical mapping of the extent. The Mcb package operates on ULONG/ULONG
// keys and values so we must render our 48bit address into 32. We can do this since
// this is a single surface implementation, and it is guaranteed that a surface cannot
// contain more than MAXULONG physical sectors.
Psn = UdfLookupPsnOfExtent( IrpContext,
Vcb,
Reference,
Lbn,
Len );
// Use try-finally for cleanup
try {
// We must safely establish a mapping and extend the metadata stream so that cached
// reads can occur on this new extent.
Fcb = Vcb->MetadataFcb;
UdfLockFcb( IrpContext, Fcb );
Result = UdfVmcbLbnToVbn( &Vcb->Vmcb,
Psn,
&Vsn,
&SectorCount );
if (Result) {
// If the mapping covers the extent, we can give this back.
if (BlocksFromSectors( Vcb, SectorCount ) >= BlocksFromBytes( Vcb, Len )) {
try_leave( NOTHING );
}
// It is a fatal error if the extent we are mapping is not wholly contained
// by an extent of Vsns in the Vmcb. This will indicate that some structure
// is trying to overlap another.
UdfRaiseStatus( IrpContext, STATUS_FILE_CORRUPT_ERROR );
}
// Add the new mapping. We know that it is being added to the end of the stream.
UdfAddVmcbMapping( &Vcb->Vmcb,
Psn,
SectorsFromBytes( Vcb, Len ),
ExactEnd,
&Vsn,
&SectorCount );
UnwindAllocationSize = Fcb->AllocationSize.QuadPart;
UnwindExtension = TRUE;
Fcb->AllocationSize.QuadPart =
Fcb->FileSize.QuadPart =
Fcb->ValidDataLength.QuadPart = LlBytesFromSectors( Vcb, Vsn + SectorCount);
CcSetFileSizes( Fcb->FileObject, (PCC_FILE_SIZES) &Fcb->AllocationSize );
UnwindExtension = FALSE;
// We do not need to purge the cache maps since the Vmcb will always be
// page aligned, and thus any reads will have filled it with valid data.
} finally {
if (UnwindExtension) {
ULONG FirstZappedVsn;
// Strip off the additional mappings we made.
Fcb->AllocationSize.QuadPart =
Fcb->FileSize.QuadPart =
Fcb->ValidDataLength.QuadPart = UnwindAllocationSize;
FirstZappedVsn = SectorsFromBytes( Vcb, UnwindAllocationSize );
UdfRemoveVmcbMapping( &Vcb->Vmcb,
FirstZappedVsn,
Vsn + SectorCount - FirstZappedVsn );
CcSetFileSizes( Fcb->FileObject, (PCC_FILE_SIZES) &Fcb->AllocationSize );
}
if (Fcb) { UdfUnlockFcb( IrpContext, Fcb ); }
}
return Vsn;
}
// Local support routine.
PPCB
UdfCreatePcb (
IN ULONG NumberOfPartitions
)
/*++
Routine Description:
This routine creates a new Pcb of the indicated size.
Arguments:
NumberOfPartitions - Number of partitions this Pcb will describe
Return Value:
PPCB - the Pcb created
--*/
{
PPCB Pcb;
ULONG Size = sizeof(PCB) + sizeof(PARTITION)*NumberOfPartitions;
PAGED_CODE();
ASSERT( NumberOfPartitions );
ASSERT( NumberOfPartitions < MAXUSHORT );
Pcb = (PPCB) FsRtlAllocatePoolWithTag( UdfPagedPool,
Size,
TAG_PCB );
RtlZeroMemory( Pcb, Size );
Pcb->NodeTypeCode = UDFS_NTC_PCB;
Pcb->NodeByteSize = (USHORT) Size;
Pcb->Partitions = (USHORT)NumberOfPartitions;
return Pcb;
}
// Internal support routine
NTSTATUS
UdfLoadSparingTables(
PIRP_CONTEXT IrpContext,
PVCB Vcb,
PPCB Pcb,
ULONG Reference
)
/*++
Routine Description:
This routine reads the sparing tables for a partition and fills
in the sparing Mcb.
Arguments:
Vcb - the volume hosting the spared partition
Pcb - the partion block corresponding to the volume
Reference - the partition reference being pulled in
Return Value:
NTSTATUS according to whether the sparing tables were loaded
--*/
{
NTSTATUS Status;
ULONG SparingTable;
PULONG SectorBuffer;
ULONG Psn;
ULONG RemainingBytes;
ULONG ByteOffset;
ULONG TotalBytes;
BOOLEAN Complete;
PSPARING_TABLE_HEADER Header;
PSPARING_TABLE_ENTRY Entry;
PPARTITION Partition = &Pcb->Partition[Reference];
PPARTMAP_SPARABLE Map = Partition->Physical.SparingMap;
ASSERT_IRP_CONTEXT( IrpContext );
ASSERT_VCB( Vcb );
ASSERT( Map != NULL );
DebugTrace(( +1, Dbg, "UdfLoadSparingTables, Vcb %08x, PcbPartition %08x, Map @ %08x\n", Vcb, Partition, Map ));
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, Map sez: PacketLen %u, NTables %u, TableSize %u\n",
Map->PacketLength,
Map->NumSparingTables,
Map->TableSize));
// Check that the sparale map appears sane. If there are no sparing tables that
// is pretty OK, and it'll wind up looking like a regular physical partition.
if (Map->NumSparingTables == 0) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, no sparing tables claimed!\n" ));
DebugTrace(( -1, Dbg, "UdfLoadSparingTables -> STATUS_SUCCESS\n" ));
return STATUS_SUCCESS;
}
if (Map->NumSparingTables > sizeof(Map->TableLocation)/sizeof(ULONG)) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, too many claimed tables to fit! (max %u)\n",
sizeof(Map->TableLocation)/sizeof(ULONG)));
DebugTrace(( -1, Dbg, "UdfLoadSparingTables -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
if (Map->PacketLength != UDF_SPARING_PACKET_LENGTH) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, packet size is %u (not %u!\n",
Map->PacketLength,
UDF_SPARING_PACKET_LENGTH ));
DebugTrace(( -1, Dbg, "UdfLoadSparingTables -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
if (Map->TableSize < sizeof(SPARING_TABLE_HEADER) ||
(Map->TableSize - sizeof(SPARING_TABLE_HEADER)) % sizeof(SPARING_TABLE_ENTRY) != 0) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, sparing table size is too small or unaligned!\n" ));
DebugTrace(( -1, Dbg, "UdfLoadSparingTables -> STATUS_DISK_CORRUPT_ERROR\n" ));
return STATUS_DISK_CORRUPT_ERROR;
}
#ifdef UDF_SANITY
DebugTrace(( 0, Dbg, "UdfLoadSparingTables" ));
for (SparingTable = 0; SparingTable < Map->NumSparingTables; SparingTable++) {
DebugTrace(( 0, Dbg, ", Table %u @ %x", SparingTable, Map->TableLocation[SparingTable] ));
}
DebugTrace(( 0, Dbg, "\n" ));
#endif
// If a sparing mcb doesn't exist, manufacture one.
if (Pcb->SparingMcb == NULL) {
Pcb->SparingMcb = FsRtlAllocatePoolWithTag( PagedPool, sizeof(LARGE_MCB), TAG_SPARING_MCB );
FsRtlInitializeLargeMcb( Pcb->SparingMcb, PagedPool );
}
SectorBuffer = FsRtlAllocatePoolWithTag( PagedPool, PAGE_SIZE, TAG_NSR_FSD );
// Now loop across the sparing tables and pull the data in.
try {
for (Complete = FALSE, SparingTable = 0;
SparingTable < Map->NumSparingTables;
SparingTable++) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, loading sparing table %u!\n",
SparingTable ));
ByteOffset = 0;
TotalBytes = 0;
RemainingBytes = 0;
do {
if (RemainingBytes == 0) {
(VOID) UdfReadSectors( IrpContext,
BytesFromSectors( Vcb, Map->TableLocation[SparingTable] ) + ByteOffset,
SectorSize( Vcb ),
FALSE,
SectorBuffer,
Vcb->TargetDeviceObject );
// Verify the descriptor at the head of the sparing table. If it is not
// valid, we just break out for a chance at the next table, if any.
if (ByteOffset == 0) {
Header = (PSPARING_TABLE_HEADER) SectorBuffer;
if (!UdfVerifyDescriptor( IrpContext,
&Header->Destag,
0,
SectorSize( Vcb ),
Header->Destag.Lbn,
TRUE )) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, sparing table %u didn't verify destag!\n",
SparingTable ));
break;
}
if (!UdfUdfIdentifierContained( &Header->RegID,
&UdfSparingTableIdentifier,
UDF_VERSION_150,
UDF_VERSION_RECOGNIZED,
OSCLASS_INVALID,
OSIDENTIFIER_INVALID)) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, sparing table %u didn't verify regid!\n",
SparingTable ));
break;
}
// Calculate the total number bytes this map spans and check it against what
// we were told the sparing table sizes are.
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, Sparing table %u has %u entries\n",
SparingTable,
Header->TableEntries ));
TotalBytes = sizeof(SPARING_TABLE_HEADER) + Header->TableEntries * sizeof(SPARING_TABLE_ENTRY);
if (Map->TableSize < TotalBytes) {
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, sparing table #ents %u overflows allocation!\n",
Header->TableEntries ));
break;
}
// So far so good, advance past the header.
ByteOffset = sizeof(SPARING_TABLE_HEADER);
Entry = Add2Ptr( SectorBuffer, sizeof(SPARING_TABLE_HEADER), PSPARING_TABLE_ENTRY );
} else {
// Pick up in the new sector.
Entry = (PSPARING_TABLE_ENTRY) SectorBuffer;
}
RemainingBytes = Min( SectorSize( Vcb ), TotalBytes - ByteOffset );
}
// Add the mapping. Since sparing tables are an Lbn->Psn mapping,
// very odd, and I want to simplify things by putting the sparing
// in right at IO dispatch, translate this to a Psn->Psn mapping.
if (Entry->Original != UDF_SPARING_AVALIABLE &&
Entry->Original != UDF_SPARING_DEFECTIVE) {
Psn = Partition->Physical.Start + SectorsFromBlocks( Vcb, Entry->Original );
DebugTrace(( 0, Dbg, "UdfLoadSparingTables, mapping from Psn %x (Lbn %x) -> Psn %x\n",
Psn,
Entry->Original,
Entry->Mapped ));
FsRtlAddLargeMcbEntry( Pcb->SparingMcb,
Psn,
Entry->Mapped,
UDF_SPARING_PACKET_LENGTH );
}
// Advance to the next, and drop out if we've hit the end.
ByteOffset += sizeof(SPARING_TABLE_ENTRY);
RemainingBytes -= sizeof(SPARING_TABLE_ENTRY);
Entry++;
} while ( ByteOffset < TotalBytes );
}
} finally {
DebugUnwind( UdfLoadSparingTables );
UdfFreePool( &SectorBuffer );
}
DebugTrace(( -1, Dbg, "UdfLoadSparingTables -> STATUS_SUCCESS\n" ));
return STATUS_SUCCESS;
}
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