[tthompson] 75284: [NTFS] - Add some fixes and improvements to mft.c from CR-123: FindAttribute() - Use * sizeof(WCHAR) in place bit-shifting wizardry. IncreaseMftSize() - Remove two useless casts....
Author: tthompson Date: Wed Jul 5 05:09:51 2017 New Revision: 75284
URL: http://svn.reactos.org/svn/reactos?rev=75284&view=rev Log: [NTFS] - Add some fixes and improvements to mft.c from CR-123: FindAttribute() - Use * sizeof(WCHAR) in place bit-shifting wizardry. IncreaseMftSize() - Remove two useless casts. Return error code if WriteAttribute() fails. SetNonResidentAttributeDataLength() - Assert that AttrContext parameter describes a NonResident attribute. When migrating a resident attribute to non-resident, don't leak memory if FsRtlInitializeLargeMcb() throws an exception, and don't mark the attribute as non-resident until after the Mcb is initialized. InternalSetResidentAttributeLength() and SetResidentAttributeLength() - Assert that AttrContext parameter describes a resident attribute. AddNewMftEntry() - Simplify math of backing up and restoring reserved bits by changing BitmapData to PUCHAR type. Don't attempt to modify a volume with more than 2^32 clusters. AddFixupArray() - Use ULONG in place of int.
Modified: branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/mft.c
Modified: branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/mft.c URL: http://svn.reactos.org/svn/reactos/branches/GSoC_2016/NTFS/drivers/filesyste... ============================================================================== --- branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/mft.c [iso-8859-1] (original) +++ branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/mft.c [iso-8859-1] Wed Jul 5 05:09:51 2017 @@ -133,7 +133,7 @@
AttrName = (PWCHAR)((PCHAR)Attribute + Attribute->NameOffset); DPRINT("%.*S, %.*S\n", Attribute->NameLength, AttrName, NameLength, Name); - if (RtlCompareMemory(AttrName, Name, NameLength << 1) == (NameLength << 1)) + if (RtlCompareMemory(AttrName, Name, NameLength * sizeof(WCHAR)) == (NameLength * sizeof(WCHAR))) { Found = TRUE; } @@ -268,7 +268,7 @@ }
// Zero the bytes we'll be adding - RtlZeroMemory((PUCHAR)((ULONG_PTR)BitmapBuffer), NewBitmapSize); + RtlZeroMemory(BitmapBuffer, NewBitmapSize);
// Read the bitmap attribute BytesRead = ReadAttribute(Vcb, @@ -337,6 +337,7 @@ ExFreePoolWithTag(BitmapBuffer, TAG_NTFS); ReleaseAttributeContext(BitmapContext); DPRINT1("ERROR: Couldn't write to bitmap attribute of $MFT!\n"); + return Status; }
// Cleanup @@ -357,6 +358,8 @@ ULONG NextAttributeOffset;
DPRINT("InternalSetResidentAttributeLength( %p, %p, %lu, %lu )\n", AttrContext, FileRecord, AttrOffset, DataSize); + + ASSERT(!AttrContext->Record.IsNonResident);
// update ValueLength Field AttrContext->Record.Resident.ValueLength = @@ -537,11 +540,7 @@ 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; - } + ASSERT(AttrContext->Record.IsNonResident);
// do we need to increase the allocation size? if (AttrContext->Record.NonResident.AllocatedSize < AllocationSize) @@ -671,11 +670,7 @@ 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; - } + ASSERT(!AttrContext->Record.IsNonResident);
//NtfsDumpFileAttributes(Vcb, FileRecord);
@@ -733,9 +728,6 @@ // 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; @@ -750,7 +742,22 @@ (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord + EndAttributeOffset), FILE_RECORD_END);
- // update file record on disk + // Initialize the MCB, potentially catch an exception + _SEH2_TRY + { + FsRtlInitializeLargeMcb(&AttrContext->DataRunsMCB, NonPagedPool); + } + _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER) + { + DPRINT1("Unable to create LargeMcb!\n"); + ExFreePoolWithTag(AttribData, TAG_NTFS); + _SEH2_YIELD(return _SEH2_GetExceptionCode()); + } _SEH2_END; + + // Mark the attribute as non-resident (we wait until after we know the LargeMcb was initialized) + AttrContext->Record.IsNonResident = Destination->IsNonResident = 1; + + // Update file record on disk Status = UpdateFileRecord(Vcb, AttrContext->FileMFTIndex, FileRecord); if (!NT_SUCCESS(Status)) { @@ -759,13 +766,6 @@ 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); @@ -1729,7 +1729,7 @@ RTL_BITMAP Bitmap; ULONGLONG BitmapDataSize; ULONGLONG AttrBytesRead; - PVOID BitmapData; + PUCHAR BitmapData; ULONG LengthWritten; PNTFS_ATTR_CONTEXT BitmapContext; LARGE_INTEGER BitmapBits; @@ -1765,17 +1765,20 @@ return STATUS_OBJECT_NAME_NOT_FOUND; }
- // we need to backup the bits for records 0x10 - 0x17 and leave them unassigned if they aren't assigned - RtlCopyMemory(&SystemReservedBits, (PVOID)((ULONG_PTR)BitmapData + 2), 1); - RtlFillMemory((PVOID)((ULONG_PTR)BitmapData + 2), 1, (UCHAR)0xFF); + // We need to backup the bits for records 0x10 - 0x17 (3rd byte of bitmap) and mark these records + // as in-use so we don't assign files to those indices. They're reserved for the system (e.g. ChkDsk). + SystemReservedBits = BitmapData[2]; + BitmapData[2] = 0xff;
// Calculate bit count BitmapBits.QuadPart = AttributeDataLength(&(DeviceExt->MFTContext->Record)) / DeviceExt->NtfsInfo.BytesPerFileRecord; if (BitmapBits.HighPart != 0) { - DPRINT1("\tFIXME: bitmap sizes beyond 32bits are not yet supported!\n"); - BitmapBits.LowPart = 0xFFFFFFFF; + DPRINT1("\tFIXME: bitmap sizes beyond 32bits are not yet supported! (Your NTFS volume is too large)\n"); + ExFreePoolWithTag(BitmapData, TAG_NTFS); + ReleaseAttributeContext(BitmapContext); + return STATUS_NOT_IMPLEMENTED; }
// convert buffer into bitmap @@ -1809,7 +1812,7 @@ // [BitmapData should have been updated via RtlFindClearBitsAndSet()]
// Restore the system reserved bits - RtlCopyMemory((PVOID)((ULONG_PTR)BitmapData + 2), &SystemReservedBits, 1); + BitmapData[2] = SystemReservedBits;
// write the bitmap back to the MFT's $Bitmap attribute Status = WriteAttribute(DeviceExt, BitmapContext, 0, BitmapData, BitmapDataSize, &LengthWritten); @@ -1845,9 +1848,9 @@ PNTFS_RECORD_HEADER Record) { USHORT *pShortToFixUp; - unsigned int ArrayEntryCount = Record->UsaCount - 1; - unsigned int Offset = Vcb->NtfsInfo.BytesPerSector - 2; - int i; + ULONG ArrayEntryCount = Record->UsaCount - 1; + ULONG Offset = Vcb->NtfsInfo.BytesPerSector - 2; + ULONG i;
PFIXUP_ARRAY fixupArray = (PFIXUP_ARRAY)((UCHAR*)Record + Record->UsaOffset);
-
tthompson＠svn.reactos.org