Comment inline.
Le 19/07/2016 à 17:31, tthompson@svn.reactos.org a écrit :
Author: tthompson Date: Tue Jul 19 15:31:22 2016 New Revision: 71968
URL: http://svn.reactos.org/svn/reactos?rev=71968&view=rev Log: [NTFS] +FreeClusters(). Fix a DPRINT.
Modified: branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/attrib.c branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/mft.c branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/ntfs.h
Modified: branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/attrib.c URL: http://svn.reactos.org/svn/reactos/branches/GSoC_2016/NTFS/drivers/filesyste... ============================================================================== --- branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/attrib.c [iso-8859-1] (original) +++ branches/GSoC_2016/NTFS/drivers/filesystems/ntfs/attrib.c [iso-8859-1] Tue Jul 19 15:31:22 2016 @@ -409,6 +409,208 @@ return TRUE; }
+/** +* @name FreeClusters +* @implemented +* +* Shrinks the allocation size of a non-resident attribute by a given number of clusters. +* Frees the clusters from the volume's $BITMAP file as well as the attribute's data runs. +* +* @param Vcb +* Pointer to an NTFS_VCB for the destination volume. +* +* @param AttrContext +* Pointer to an NTFS_ATTR_CONTEXT describing the attribute from which the clusters will be freed. +* +* @param AttrOffset +* Byte offset of the destination attribute relative to its file record. +* +* @param FileRecord +* Pointer to a complete copy of the file record containing the attribute. Must be at least +* Vcb->NtfsInfo.BytesPerFileRecord bytes long. +* +* @param ClustersToFree +* Number of clusters that should be freed from the end of the data stream. Must be no more +* Than the number of clusters assigned to the attribute (HighestVCN + 1). +* +* @return +* STATUS_SUCCESS on success. STATUS_INVALID_PARAMETER if AttrContext describes a resident attribute, +* or if the caller requested more clusters be freed than the attribute has been allocated. +* STATUS_INSUFFICIENT_RESOURCES if ConvertDataRunsToLargeMCB() fails. +* STATUS_BUFFER_TOO_SMALL if ConvertLargeMCBToDataRuns() fails. +* +* +*/ +NTSTATUS +FreeClusters(PNTFS_VCB Vcb,
PNTFS_ATTR_CONTEXT AttrContext,ULONG AttrOffset,PFILE_RECORD_HEADER FileRecord,ULONG ClustersToFree)+{
- NTSTATUS Status = STATUS_SUCCESS;
- ULONG ClustersLeftToFree = ClustersToFree;
- // convert data runs to mcb
- PUCHAR DataRun = (PUCHAR)&AttrContext->Record + AttrContext->Record.NonResident.MappingPairsOffset;
- PNTFS_ATTR_RECORD DestinationAttribute = (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord + AttrOffset);
- LARGE_MCB DataRunsMCB;
- ULONG NextAttributeOffset = AttrOffset + AttrContext->Record.Length;
- PNTFS_ATTR_RECORD NextAttribute = (PNTFS_ATTR_RECORD)((ULONG_PTR)FileRecord + NextAttributeOffset);
- ULONGLONG NextVBN = AttrContext->Record.NonResident.LowestVCN;
- // Allocate some memory for the RunBuffer
- PUCHAR RunBuffer = ExAllocatePoolWithTag(NonPagedPool, Vcb->NtfsInfo.BytesPerFileRecord, TAG_NTFS);
- ULONG RunBufferOffset = 0;
Two notes regarding this allocation: - You should check allocation worked (obviously ;-)); - You should start memory work only after checking the record is not resident.
-
Pierre Schweitzer