10 Dec
2017
10 Dec
'17
11:50 a.m.
https://git.reactos.org/?p=reactos.git;a=commitdiff;h=1417f286e03dbb76ad9dd…
commit 1417f286e03dbb76ad9ddd99929fbfef5b789a68
Author: Trevor Thompson <tmt256(a)email.vccs.edu>
AuthorDate: Fri Jun 16 05:43:52 2017 +0000
[NTFS] - Restructure some code in preparation for the next commit:
-SetAttributeDataLength() has been split into two functions,
SetNonResidentAttributeDataLength() and SetResidentAttributeDataLength(). This should
improve code readibility and allows for resizing an attribute when there's no
FileObject associated with it.
-Added "MftDataOffset" member to DEVICE_EXTENSION, which stores the offset
of the Mft's $DATA attribute. (I'm starting to think it's better to add a
member for offset to NTFS_ATTR_CONTEXT directly, but I'll save that level of
restructuring for a future commit.)
svn path=/branches/GSoC_2016/NTFS/; revision=75055
---
drivers/filesystems/ntfs/fsctl.c | 8 +-
drivers/filesystems/ntfs/mft.c | 557 ++++++++++++++++++++++++---------------
drivers/filesystems/ntfs/ntfs.h | 15 ++
3 files changed, 360 insertions(+), 220 deletions(-)
diff --git a/drivers/filesystems/ntfs/fsctl.c b/drivers/filesystems/ntfs/fsctl.c
index a1f3048cd0..8acdd64e16 100644
--- a/drivers/filesystems/ntfs/fsctl.c
+++ b/drivers/filesystems/ntfs/fsctl.c
@@ -295,7 +295,13 @@ NtfsGetVolumeData(PDEVICE_OBJECT DeviceObject,
return Status;
}
- Status = FindAttribute(DeviceExt, DeviceExt->MasterFileTable, AttributeData,
L"", 0, &DeviceExt->MFTContext, NULL);
+ Status = FindAttribute(DeviceExt,
+ DeviceExt->MasterFileTable,
+ AttributeData,
+ L"",
+ 0,
+ &DeviceExt->MFTContext,
+ &DeviceExt->MftDataOffset);
if (!NT_SUCCESS(Status))
{
DPRINT1("Can't find data attribute for Master File Table.\n");
diff --git a/drivers/filesystems/ntfs/mft.c b/drivers/filesystems/ntfs/mft.c
index 5b9b291e4e..52a7caaa43 100644
--- a/drivers/filesystems/ntfs/mft.c
+++ b/drivers/filesystems/ntfs/mft.c
@@ -234,7 +234,6 @@ SetAttributeDataLength(PFILE_OBJECT FileObject,
PLARGE_INTEGER DataSize)
{
NTSTATUS Status = STATUS_SUCCESS;
- ULONG BytesPerCluster = Fcb->Vcb->NtfsInfo.BytesPerCluster;
// are we truncating the file?
if (DataSize->QuadPart < AttributeDataLength(&AttrContext->Record))
@@ -248,229 +247,26 @@ SetAttributeDataLength(PFILE_OBJECT FileObject,
if (AttrContext->Record.IsNonResident)
{
- ULONGLONG AllocationSize = ROUND_UP(DataSize->QuadPart, BytesPerCluster);
- PNTFS_ATTR_RECORD DestinationAttribute =
(PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord + AttrOffset);
- ULONG ExistingClusters = AttrContext->Record.NonResident.AllocatedSize /
BytesPerCluster;
-
- // do we need to increase the allocation size?
- if (AttrContext->Record.NonResident.AllocatedSize < AllocationSize)
- {
- ULONG ClustersNeeded = (AllocationSize / BytesPerCluster) -
ExistingClusters;
- LARGE_INTEGER LastClusterInDataRun;
- ULONG NextAssignedCluster;
- ULONG AssignedClusters;
-
- if (ExistingClusters == 0)
- {
- LastClusterInDataRun.QuadPart = 0;
- }
- else
- {
- if (!FsRtlLookupLargeMcbEntry(&AttrContext->DataRunsMCB,
-
(LONGLONG)AttrContext->Record.NonResident.HighestVCN,
-
(PLONGLONG)&LastClusterInDataRun.QuadPart,
- NULL,
- NULL,
- NULL,
- NULL))
- {
- DPRINT1("Error looking up final large MCB entry!\n");
-
- // Most likely, HighestVCN went above the largest mapping
- DPRINT1("Highest VCN of record: %I64u\n",
AttrContext->Record.NonResident.HighestVCN);
- return STATUS_INVALID_PARAMETER;
- }
- }
-
- DPRINT("LastClusterInDataRun: %I64u\n",
LastClusterInDataRun.QuadPart);
- DPRINT("Highest VCN of record: %I64u\n",
AttrContext->Record.NonResident.HighestVCN);
-
- while (ClustersNeeded > 0)
- {
- Status = NtfsAllocateClusters(Fcb->Vcb,
- LastClusterInDataRun.LowPart + 1,
- ClustersNeeded,
- &NextAssignedCluster,
- &AssignedClusters);
-
- if (!NT_SUCCESS(Status))
- {
- DPRINT1("Error: Unable to allocate requested
clusters!\n");
- return Status;
- }
-
- // now we need to add the clusters we allocated to the data run
- Status = AddRun(Fcb->Vcb, AttrContext, AttrOffset, FileRecord,
NextAssignedCluster, AssignedClusters);
- if (!NT_SUCCESS(Status))
- {
- DPRINT1("Error: Unable to add data run!\n");
- return Status;
- }
-
- ClustersNeeded -= AssignedClusters;
- LastClusterInDataRun.LowPart = NextAssignedCluster + AssignedClusters -
1;
- }
- }
- else if (AttrContext->Record.NonResident.AllocatedSize > AllocationSize)
- {
- // shrink allocation size
- ULONG ClustersToFree = ExistingClusters - (AllocationSize /
BytesPerCluster);
- Status = FreeClusters(Fcb->Vcb, AttrContext, AttrOffset, FileRecord,
ClustersToFree);
- }
-
- // TODO: is the file compressed, encrypted, or sparse?
-
- // NOTE: we need to have acquired the main resource exclusively, as well as(?)
the PagingIoResource
-
- Fcb->RFCB.AllocationSize.QuadPart = AllocationSize;
- AttrContext->Record.NonResident.AllocatedSize = AllocationSize;
- AttrContext->Record.NonResident.DataSize = DataSize->QuadPart;
- AttrContext->Record.NonResident.InitializedSize = DataSize->QuadPart;
-
- DestinationAttribute->NonResident.AllocatedSize = AllocationSize;
- DestinationAttribute->NonResident.DataSize = DataSize->QuadPart;
- DestinationAttribute->NonResident.InitializedSize = DataSize->QuadPart;
-
- DPRINT("Allocated Size: %I64u\n",
DestinationAttribute->NonResident.AllocatedSize);
+ Status = SetNonResidentAttributeDataLength(Fcb->Vcb,
+ AttrContext,
+ AttrOffset,
+ FileRecord,
+ DataSize);
}
else
{
// resident attribute
+ Status = SetResidentAttributeDataLength(Fcb->Vcb,
+ AttrContext,
+ AttrOffset,
+ FileRecord,
+ DataSize);
+ }
- // find the next attribute
- ULONG NextAttributeOffset = AttrOffset + AttrContext->Record.Length;
- PNTFS_ATTR_RECORD NextAttribute = (PNTFS_ATTR_RECORD)((PCHAR)FileRecord +
NextAttributeOffset);
-
- //NtfsDumpFileAttributes(Fcb->Vcb, FileRecord);
-
- // Do we need to increase the data length?
- if (DataSize->QuadPart > AttrContext->Record.Resident.ValueLength)
- {
- // There's usually padding at the end of a record. Do we need to extend
past it?
- ULONG MaxValueLength = AttrContext->Record.Length -
AttrContext->Record.Resident.ValueOffset;
- if (MaxValueLength < DataSize->LowPart)
- {
- // If this is the last attribute, we could move the end marker to the
very end of the file record
- MaxValueLength += Fcb->Vcb->NtfsInfo.BytesPerFileRecord -
NextAttributeOffset - (sizeof(ULONG) * 2);
-
- if (MaxValueLength < DataSize->LowPart || NextAttribute->Type !=
AttributeEnd)
- {
- // convert attribute to non-resident
- PNTFS_ATTR_RECORD Destination =
(PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord + AttrOffset);
- LARGE_INTEGER AttribDataSize;
- PVOID AttribData;
- ULONG EndAttributeOffset;
- ULONG LengthWritten;
-
- DPRINT1("Converting attribute to non-resident.\n");
-
- AttribDataSize.QuadPart =
AttrContext->Record.Resident.ValueLength;
-
- // Is there existing data we need to back-up?
- if (AttribDataSize.QuadPart > 0)
- {
- AttribData = ExAllocatePoolWithTag(NonPagedPool,
AttribDataSize.QuadPart, TAG_NTFS);
- if (AttribData == NULL)
- {
- DPRINT1("ERROR: Couldn't allocate memory for
attribute data. Can't migrate to non-resident!\n");
- return STATUS_INSUFFICIENT_RESOURCES;
- }
-
- // read data to temp buffer
- Status = ReadAttribute(Fcb->Vcb, AttrContext, 0, AttribData,
AttribDataSize.QuadPart);
- if (!NT_SUCCESS(Status))
- {
- DPRINT1("ERROR: Unable to read attribute before
migrating!\n");
- ExFreePoolWithTag(AttribData, TAG_NTFS);
- return Status;
- }
- }
-
- // Start by turning this attribute into a 0-length, non-resident
attribute, then enlarge it.
-
- // Zero out the NonResident structure
- RtlZeroMemory(&AttrContext->Record.NonResident.LowestVCN,
- FIELD_OFFSET(NTFS_ATTR_RECORD,
NonResident.CompressedSize) - FIELD_OFFSET(NTFS_ATTR_RECORD, NonResident.LowestVCN));
- RtlZeroMemory(&Destination->NonResident.LowestVCN,
- FIELD_OFFSET(NTFS_ATTR_RECORD,
NonResident.CompressedSize) - FIELD_OFFSET(NTFS_ATTR_RECORD, NonResident.LowestVCN));
-
- // update the mapping pairs offset, which will be 0x40 + length in
bytes of the name
- AttrContext->Record.NonResident.MappingPairsOffset =
Destination->NonResident.MappingPairsOffset = 0x40 + (Destination->NameLength * 2);
-
- // mark the attribute as non-resident
- AttrContext->Record.IsNonResident = Destination->IsNonResident
= 1;
-
- // update the end of the file record
- // calculate position of end markers (1 byte for empty data run)
- EndAttributeOffset = AttrOffset +
AttrContext->Record.NonResident.MappingPairsOffset + 1;
- EndAttributeOffset = ALIGN_UP_BY(EndAttributeOffset, 8);
-
- // Update the length
- Destination->Length = EndAttributeOffset - AttrOffset;
- AttrContext->Record.Length = Destination->Length;
-
- // Update the file record end
- SetFileRecordEnd(FileRecord,
- (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord +
EndAttributeOffset),
- FILE_RECORD_END);
-
- // update file record on disk
- Status = UpdateFileRecord(Fcb->Vcb, AttrContext->FileMFTIndex,
FileRecord);
- if (!NT_SUCCESS(Status))
- {
- DPRINT1("ERROR: Couldn't update file record to continue
migration!\n");
- if (AttribDataSize.QuadPart > 0)
- ExFreePoolWithTag(AttribData, TAG_NTFS);
- return Status;
- }
-
- // Initialize the MCB, potentially catch an exception
- _SEH2_TRY{
- FsRtlInitializeLargeMcb(&AttrContext->DataRunsMCB,
NonPagedPool);
- } _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER) {
- _SEH2_YIELD(return _SEH2_GetExceptionCode());
- } _SEH2_END;
-
- // Now we can treat the attribute as non-resident and enlarge it
normally
- Status = SetAttributeDataLength(FileObject, Fcb, AttrContext,
AttrOffset, FileRecord, DataSize);
- if (!NT_SUCCESS(Status))
- {
- DPRINT1("ERROR: Unable to migrate resident
attribute!\n");
- if (AttribDataSize.QuadPart > 0)
- ExFreePoolWithTag(AttribData, TAG_NTFS);
- return Status;
- }
-
- // restore the back-up attribute, if we made one
- if (AttribDataSize.QuadPart > 0)
- {
- Status = WriteAttribute(Fcb->Vcb, AttrContext, 0, AttribData,
AttribDataSize.QuadPart, &LengthWritten);
- if (!NT_SUCCESS(Status))
- {
- DPRINT1("ERROR: Unable to write attribute data to
non-resident clusters during migration!\n");
- // TODO: Reverse migration so no data is lost
- ExFreePoolWithTag(AttribData, TAG_NTFS);
- return Status;
- }
-
- ExFreePoolWithTag(AttribData, TAG_NTFS);
- }
- }
- }
- }
- else if (DataSize->LowPart < AttrContext->Record.Resident.ValueLength)
- {
- // we need to decrease the length
- if (NextAttribute->Type != AttributeEnd)
- {
- DPRINT1("FIXME: Don't know how to decrease length of resident
attribute unless it's the final attribute!\n");
- return STATUS_NOT_IMPLEMENTED;
- }
- }
-
- // set the new length of the resident attribute (if we didn't migrate it)
- if(!AttrContext->Record.IsNonResident)
- InternalSetResidentAttributeLength(AttrContext, FileRecord, AttrOffset,
DataSize->LowPart);
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("ERROR: Failed to set size of attribute!\n");
+ return Status;
}
//NtfsDumpFileAttributes(Fcb->Vcb, FileRecord);
@@ -480,6 +276,10 @@ SetAttributeDataLength(PFILE_OBJECT FileObject,
if (NT_SUCCESS(Status))
{
+ if(AttrContext->Record.IsNonResident)
+ Fcb->RFCB.AllocationSize.QuadPart =
AttrContext->Record.NonResident.AllocatedSize;
+ else
+ Fcb->RFCB.AllocationSize = *DataSize;
Fcb->RFCB.FileSize = *DataSize;
Fcb->RFCB.ValidDataLength = *DataSize;
CcSetFileSizes(FileObject, (PCC_FILE_SIZES)&Fcb->RFCB.AllocationSize);
@@ -523,6 +323,325 @@ SetFileRecordEnd(PFILE_RECORD_HEADER FileRecord,
FileRecord->BytesInUse = (ULONG_PTR)AttrEnd - (ULONG_PTR)FileRecord +
sizeof(ULONG) * 2;
}
+/**
+* @name SetNonResidentAttributeDataLength
+* @implemented
+*
+* Called by SetAttributeDataLength() to set the size of a non-resident attribute.
Doesn't update the file record.
+*
+* @param Vcb
+* Pointer to a DEVICE_EXTENSION describing the target disk.
+*
+* @param AttrContext
+* PNTFS_ATTR_CONTEXT describing the location of the attribute whose size is being set.
+*
+* @param AttrOffset
+* Offset, from the beginning of the record, of the attribute being sized.
+*
+* @param FileRecord
+* Pointer to a file record containing the attribute to be resized. Must be a complete
file record,
+* not just the header.
+*
+* @param DataSize
+* Pointer to a LARGE_INTEGER describing the new size of the attribute's data.
+*
+* @return
+* STATUS_SUCCESS on success;
+* STATUS_INSUFFICIENT_RESOURCES if an allocation fails.
+* STATUS_INVALID_PARAMETER if we can't find the last cluster in the data run.
+*
+* @remarks
+* Called by SetAttributeDataLength(). Use SetAttributeDataLength() unless you have a
good
+* reason to use this. Doesn't update the file record on disk. Doesn't inform the
cache controller of changes with
+* any associated files. Synchronization is the callers responsibility.
+*/
+NTSTATUS
+SetNonResidentAttributeDataLength(PDEVICE_EXTENSION Vcb,
+ PNTFS_ATTR_CONTEXT AttrContext,
+ ULONG AttrOffset,
+ PFILE_RECORD_HEADER FileRecord,
+ PLARGE_INTEGER DataSize)
+{
+ NTSTATUS Status = STATUS_SUCCESS;
+ ULONG BytesPerCluster = Vcb->NtfsInfo.BytesPerCluster;
+ ULONGLONG AllocationSize = ROUND_UP(DataSize->QuadPart, BytesPerCluster);
+ PNTFS_ATTR_RECORD DestinationAttribute = (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord +
AttrOffset);
+ ULONG ExistingClusters = AttrContext->Record.NonResident.AllocatedSize /
BytesPerCluster;
+
+ if (!AttrContext->Record.IsNonResident)
+ {
+ DPRINT1("ERROR: SetNonResidentAttributeDataLength() called for resident
attribute!\n");
+ return STATUS_INVALID_PARAMETER;
+ }
+
+ // do we need to increase the allocation size?
+ if (AttrContext->Record.NonResident.AllocatedSize < AllocationSize)
+ {
+ ULONG ClustersNeeded = (AllocationSize / BytesPerCluster) - ExistingClusters;
+ LARGE_INTEGER LastClusterInDataRun;
+ ULONG NextAssignedCluster;
+ ULONG AssignedClusters;
+
+ if (ExistingClusters == 0)
+ {
+ LastClusterInDataRun.QuadPart = 0;
+ }
+ else
+ {
+ if (!FsRtlLookupLargeMcbEntry(&AttrContext->DataRunsMCB,
+
(LONGLONG)AttrContext->Record.NonResident.HighestVCN,
+ (PLONGLONG)&LastClusterInDataRun.QuadPart,
+ NULL,
+ NULL,
+ NULL,
+ NULL))
+ {
+ DPRINT1("Error looking up final large MCB entry!\n");
+
+ // Most likely, HighestVCN went above the largest mapping
+ DPRINT1("Highest VCN of record: %I64u\n",
AttrContext->Record.NonResident.HighestVCN);
+ return STATUS_INVALID_PARAMETER;
+ }
+ }
+
+ DPRINT("LastClusterInDataRun: %I64u\n",
LastClusterInDataRun.QuadPart);
+ DPRINT("Highest VCN of record: %I64u\n",
AttrContext->Record.NonResident.HighestVCN);
+
+ while (ClustersNeeded > 0)
+ {
+ Status = NtfsAllocateClusters(Vcb,
+ LastClusterInDataRun.LowPart + 1,
+ ClustersNeeded,
+ &NextAssignedCluster,
+ &AssignedClusters);
+
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("Error: Unable to allocate requested clusters!\n");
+ return Status;
+ }
+
+ // now we need to add the clusters we allocated to the data run
+ Status = AddRun(Vcb, AttrContext, AttrOffset, FileRecord,
NextAssignedCluster, AssignedClusters);
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("Error: Unable to add data run!\n");
+ return Status;
+ }
+
+ ClustersNeeded -= AssignedClusters;
+ LastClusterInDataRun.LowPart = NextAssignedCluster + AssignedClusters - 1;
+ }
+ }
+ else if (AttrContext->Record.NonResident.AllocatedSize > AllocationSize)
+ {
+ // shrink allocation size
+ ULONG ClustersToFree = ExistingClusters - (AllocationSize / BytesPerCluster);
+ Status = FreeClusters(Vcb, AttrContext, AttrOffset, FileRecord, ClustersToFree);
+ }
+
+ // TODO: is the file compressed, encrypted, or sparse?
+
+ AttrContext->Record.NonResident.AllocatedSize = AllocationSize;
+ AttrContext->Record.NonResident.DataSize = DataSize->QuadPart;
+ AttrContext->Record.NonResident.InitializedSize = DataSize->QuadPart;
+
+ DestinationAttribute->NonResident.AllocatedSize = AllocationSize;
+ DestinationAttribute->NonResident.DataSize = DataSize->QuadPart;
+ DestinationAttribute->NonResident.InitializedSize = DataSize->QuadPart;
+
+ DPRINT("Allocated Size: %I64u\n",
DestinationAttribute->NonResident.AllocatedSize);
+
+ return Status;
+}
+
+/**
+* @name SetResidentAttributeDataLength
+* @implemented
+*
+* Called by SetAttributeDataLength() to set the size of a non-resident attribute.
Doesn't update the file record.
+*
+* @param Vcb
+* Pointer to a DEVICE_EXTENSION describing the target disk.
+*
+* @param AttrContext
+* PNTFS_ATTR_CONTEXT describing the location of the attribute whose size is being set.
+*
+* @param AttrOffset
+* Offset, from the beginning of the record, of the attribute being sized.
+*
+* @param FileRecord
+* Pointer to a file record containing the attribute to be resized. Must be a complete
file record,
+* not just the header.
+*
+* @param DataSize
+* Pointer to a LARGE_INTEGER describing the new size of the attribute's data.
+*
+* @return
+* STATUS_SUCCESS on success;
+* STATUS_INSUFFICIENT_RESOURCES if an allocation fails.
+* STATUS_INVALID_PARAMETER if AttrContext describes a non-resident attribute.
+* STATUS_NOT_IMPLEMENTED if requested to decrease the size of an attribute that isn't
the
+* last attribute listed in the file record.
+*
+* @remarks
+* Called by SetAttributeDataLength(). Use SetAttributeDataLength() unless you have a
good
+* reason to use this. Doesn't update the file record on disk. Doesn't inform the
cache controller of changes with
+* any associated files. Synchronization is the callers responsibility.
+*/
+NTSTATUS
+SetResidentAttributeDataLength(PDEVICE_EXTENSION Vcb,
+ PNTFS_ATTR_CONTEXT AttrContext,
+ ULONG AttrOffset,
+ PFILE_RECORD_HEADER FileRecord,
+ PLARGE_INTEGER DataSize)
+{
+ NTSTATUS Status;
+
+ // find the next attribute
+ ULONG NextAttributeOffset = AttrOffset + AttrContext->Record.Length;
+ PNTFS_ATTR_RECORD NextAttribute = (PNTFS_ATTR_RECORD)((PCHAR)FileRecord +
NextAttributeOffset);
+
+ if (AttrContext->Record.IsNonResident)
+ {
+ DPRINT1("ERROR: SetResidentAttributeDataLength() called for non-resident
attribute!\n");
+ return STATUS_INVALID_PARAMETER;
+ }
+
+ //NtfsDumpFileAttributes(Vcb, FileRecord);
+
+ // Do we need to increase the data length?
+ if (DataSize->QuadPart > AttrContext->Record.Resident.ValueLength)
+ {
+ // There's usually padding at the end of a record. Do we need to extend past
it?
+ ULONG MaxValueLength = AttrContext->Record.Length -
AttrContext->Record.Resident.ValueOffset;
+ if (MaxValueLength < DataSize->LowPart)
+ {
+ // If this is the last attribute, we could move the end marker to the very
end of the file record
+ MaxValueLength += Vcb->NtfsInfo.BytesPerFileRecord - NextAttributeOffset -
(sizeof(ULONG) * 2);
+
+ if (MaxValueLength < DataSize->LowPart || NextAttribute->Type !=
AttributeEnd)
+ {
+ // convert attribute to non-resident
+ PNTFS_ATTR_RECORD Destination = (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord
+ AttrOffset);
+ LARGE_INTEGER AttribDataSize;
+ PVOID AttribData;
+ ULONG EndAttributeOffset;
+ ULONG LengthWritten;
+
+ DPRINT1("Converting attribute to non-resident.\n");
+
+ AttribDataSize.QuadPart = AttrContext->Record.Resident.ValueLength;
+
+ // Is there existing data we need to back-up?
+ if (AttribDataSize.QuadPart > 0)
+ {
+ AttribData = ExAllocatePoolWithTag(NonPagedPool,
AttribDataSize.QuadPart, TAG_NTFS);
+ if (AttribData == NULL)
+ {
+ DPRINT1("ERROR: Couldn't allocate memory for attribute
data. Can't migrate to non-resident!\n");
+ return STATUS_INSUFFICIENT_RESOURCES;
+ }
+
+ // read data to temp buffer
+ Status = ReadAttribute(Vcb, AttrContext, 0, AttribData,
AttribDataSize.QuadPart);
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("ERROR: Unable to read attribute before
migrating!\n");
+ ExFreePoolWithTag(AttribData, TAG_NTFS);
+ return Status;
+ }
+ }
+
+ // Start by turning this attribute into a 0-length, non-resident
attribute, then enlarge it.
+
+ // Zero out the NonResident structure
+ RtlZeroMemory(&AttrContext->Record.NonResident.LowestVCN,
+ FIELD_OFFSET(NTFS_ATTR_RECORD, NonResident.CompressedSize)
- FIELD_OFFSET(NTFS_ATTR_RECORD, NonResident.LowestVCN));
+ RtlZeroMemory(&Destination->NonResident.LowestVCN,
+ FIELD_OFFSET(NTFS_ATTR_RECORD, NonResident.CompressedSize)
- FIELD_OFFSET(NTFS_ATTR_RECORD, NonResident.LowestVCN));
+
+ // update the mapping pairs offset, which will be 0x40 + length in bytes
of the name
+ AttrContext->Record.NonResident.MappingPairsOffset =
Destination->NonResident.MappingPairsOffset = 0x40 + (Destination->NameLength * 2);
+
+ // mark the attribute as non-resident
+ AttrContext->Record.IsNonResident = Destination->IsNonResident =
1;
+
+ // update the end of the file record
+ // calculate position of end markers (1 byte for empty data run)
+ EndAttributeOffset = AttrOffset +
AttrContext->Record.NonResident.MappingPairsOffset + 1;
+ EndAttributeOffset = ALIGN_UP_BY(EndAttributeOffset, 8);
+
+ // Update the length
+ Destination->Length = EndAttributeOffset - AttrOffset;
+ AttrContext->Record.Length = Destination->Length;
+
+ // Update the file record end
+ SetFileRecordEnd(FileRecord,
+ (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord +
EndAttributeOffset),
+ FILE_RECORD_END);
+
+ // update file record on disk
+ Status = UpdateFileRecord(Vcb, AttrContext->FileMFTIndex,
FileRecord);
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("ERROR: Couldn't update file record to continue
migration!\n");
+ if (AttribDataSize.QuadPart > 0)
+ ExFreePoolWithTag(AttribData, TAG_NTFS);
+ return Status;
+ }
+
+ // Initialize the MCB, potentially catch an exception
+ _SEH2_TRY{
+ FsRtlInitializeLargeMcb(&AttrContext->DataRunsMCB,
NonPagedPool);
+ } _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER) {
+ _SEH2_YIELD(return _SEH2_GetExceptionCode());
+ } _SEH2_END;
+
+ // Now we can treat the attribute as non-resident and enlarge it
normally
+ Status = SetNonResidentAttributeDataLength(Vcb, AttrContext, AttrOffset,
FileRecord, DataSize);
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("ERROR: Unable to migrate resident attribute!\n");
+ if (AttribDataSize.QuadPart > 0)
+ ExFreePoolWithTag(AttribData, TAG_NTFS);
+ return Status;
+ }
+
+ // restore the back-up attribute, if we made one
+ if (AttribDataSize.QuadPart > 0)
+ {
+ Status = WriteAttribute(Vcb, AttrContext, 0, AttribData,
AttribDataSize.QuadPart, &LengthWritten);
+ if (!NT_SUCCESS(Status))
+ {
+ DPRINT1("ERROR: Unable to write attribute data to
non-resident clusters during migration!\n");
+ // TODO: Reverse migration so no data is lost
+ ExFreePoolWithTag(AttribData, TAG_NTFS);
+ return Status;
+ }
+
+ ExFreePoolWithTag(AttribData, TAG_NTFS);
+ }
+ }
+ }
+ }
+ else if (DataSize->LowPart < AttrContext->Record.Resident.ValueLength)
+ {
+ // we need to decrease the length
+ if (NextAttribute->Type != AttributeEnd)
+ {
+ DPRINT1("FIXME: Don't know how to decrease length of resident
attribute unless it's the final attribute!\n");
+ return STATUS_NOT_IMPLEMENTED;
+ }
+ }
+
+ // set the new length of the resident attribute (if we didn't migrate it)
+ if (!AttrContext->Record.IsNonResident)
+ InternalSetResidentAttributeLength(AttrContext, FileRecord, AttrOffset,
DataSize->LowPart);
+
+ return STATUS_SUCCESS;
+}
+
ULONG
ReadAttribute(PDEVICE_EXTENSION Vcb,
PNTFS_ATTR_CONTEXT Context,
diff --git a/drivers/filesystems/ntfs/ntfs.h b/drivers/filesystems/ntfs/ntfs.h
index a3265db9da..b9336758ef 100644
--- a/drivers/filesystems/ntfs/ntfs.h
+++ b/drivers/filesystems/ntfs/ntfs.h
@@ -116,6 +116,7 @@ typedef struct
NTFS_INFO NtfsInfo;
+ ULONG MftDataOffset;
ULONG Flags;
ULONG OpenHandleCount;
@@ -869,6 +870,20 @@ SetFileRecordEnd(PFILE_RECORD_HEADER FileRecord,
PNTFS_ATTR_RECORD AttrEnd,
ULONG EndMarker);
+NTSTATUS
+SetNonResidentAttributeDataLength(PDEVICE_EXTENSION Vcb,
+ PNTFS_ATTR_CONTEXT AttrContext,
+ ULONG AttrOffset,
+ PFILE_RECORD_HEADER FileRecord,
+ PLARGE_INTEGER DataSize);
+
+NTSTATUS
+SetResidentAttributeDataLength(PDEVICE_EXTENSION Vcb,
+ PNTFS_ATTR_CONTEXT AttrContext,
+ ULONG AttrOffset,
+ PFILE_RECORD_HEADER FileRecord,
+ PLARGE_INTEGER DataSize);
+
ULONGLONG
AttributeAllocatedLength(PNTFS_ATTR_RECORD AttrRecord);