[ros-diffs] [reactos] 10/72: [NTFS] Add ability to write to resident attributes. SetAttributeDataLength() - Check if the file is memory mapped before truncating +InternalSetResidentAttributeLength() - Used by SetAttributeDataLength()

[Trevor Thompson]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=760cdfb5aa5043c49c30b…

commit 760cdfb5aa5043c49c30bec6066f682df9e12d28
Author: Trevor Thompson <tmt256(a)email.vccs.edu>
AuthorDate: Tue Jul 5 07:00:43 2016 +0000

    [NTFS]
    Add ability to write to resident attributes.
    SetAttributeDataLength() - Check if the file is memory mapped before truncating
    +InternalSetResidentAttributeLength() - Used by SetAttributeDataLength()
    
    svn path=/branches/GSoC_2016/NTFS/; revision=71820
---
 drivers/filesystems/ntfs/attrib.c  |   2 +
 drivers/filesystems/ntfs/mft.c     | 189 +++++++++++++++++++++++++++++++------
 drivers/filesystems/ntfs/ntfs.h    |   5 +
 drivers/filesystems/ntfs/volinfo.c |   3 +-
 4 files changed, 170 insertions(+), 29 deletions(-)

diff --git a/drivers/filesystems/ntfs/attrib.c b/drivers/filesystems/ntfs/attrib.c
index 9608d1d17b..e8625903bc 100644
--- a/drivers/filesystems/ntfs/attrib.c
+++ b/drivers/filesystems/ntfs/attrib.c
@@ -509,6 +509,8 @@ NtfsDumpAttribute(PDEVICE_EXTENSION Vcb,
             DbgPrint("  logical clusters: %I64u - %I64u\n",
                      lcn, lcn + runcount - 1);
         }
+        else
+            DbgPrint("    %u bytes of data\n",
Attribute->Resident.ValueLength);
     }
 }
 
diff --git a/drivers/filesystems/ntfs/mft.c b/drivers/filesystems/ntfs/mft.c
index e1725f9a50..4e10584ce0 100644
--- a/drivers/filesystems/ntfs/mft.c
+++ b/drivers/filesystems/ntfs/mft.c
@@ -135,6 +135,8 @@ FindAttribute(PDEVICE_EXTENSION Vcb,
                 DPRINT("Found context\n");
                 *AttrCtx = PrepareAttributeContext(Attribute);
 
+                (*AttrCtx)->FileMFTIndex = MftRecord->MFTRecordNumber;
+
                 if (Offset != NULL)
                     *Offset = Context.Offset;
 
@@ -170,6 +172,50 @@ AttributeDataLength(PNTFS_ATTR_RECORD AttrRecord)
         return AttrRecord->Resident.ValueLength;
 }
 
+void
+InternalSetResidentAttributeLength(PNTFS_ATTR_CONTEXT AttrContext,
+                                   PFILE_RECORD_HEADER FileRecord,
+                                   ULONG AttrOffset,
+                                   ULONG DataSize)
+{
+    ULONG EndMarker = AttributeEnd;
+    ULONG FinalMarker = FILE_RECORD_END;
+    ULONG NextAttributeOffset;
+    ULONG Offset;
+    USHORT Padding;
+
+    DPRINT("InternalSetResidentAttributeLength( %p, %p, %lu, %lu )\n",
AttrContext, FileRecord, AttrOffset, DataSize);
+
+    // update ValueLength Field
+    AttrContext->Record.Resident.ValueLength = DataSize;
+    Offset = AttrOffset + FIELD_OFFSET(NTFS_ATTR_RECORD, Resident.ValueLength);
+    RtlCopyMemory((PCHAR)FileRecord + Offset, &DataSize, sizeof(ULONG));
+
+    // calculate the record length and end marker offset
+    AttrContext->Record.Length = DataSize +
AttrContext->Record.Resident.ValueOffset;
+    NextAttributeOffset = AttrOffset + AttrContext->Record.Length;
+
+    // Ensure NextAttributeOffset is aligned to an 8-byte boundary
+    if (NextAttributeOffset % 8 != 0)
+    {
+        Padding = 8 - (NextAttributeOffset % 8);
+        NextAttributeOffset += Padding;
+        AttrContext->Record.Length += Padding;
+    }
+
+    // update the record length
+    Offset = AttrOffset + FIELD_OFFSET(NTFS_ATTR_RECORD, Length);
+    RtlCopyMemory((PCHAR)FileRecord + Offset, &AttrContext->Record.Length,
sizeof(ULONG));
+
+    // write the end marker 
+    RtlCopyMemory((PCHAR)FileRecord + NextAttributeOffset, &EndMarker,
sizeof(ULONG));
+
+    // write the final marker
+    Offset = NextAttributeOffset + sizeof(ULONG);
+    RtlCopyMemory((PCHAR)FileRecord + Offset, &FinalMarker, sizeof(ULONG));
+
+    FileRecord->BytesInUse = Offset + sizeof(ULONG);
+}
 
 NTSTATUS
 SetAttributeDataLength(PFILE_OBJECT FileObject,
@@ -179,6 +225,18 @@ SetAttributeDataLength(PFILE_OBJECT FileObject,
                        PFILE_RECORD_HEADER FileRecord,
                        PLARGE_INTEGER DataSize)
 {
+    NTSTATUS Status = STATUS_SUCCESS;
+
+    // are we truncating the file?
+    if (DataSize->QuadPart < AttributeDataLength(&AttrContext->Record)
+    {
+        if (!MmCanFileBeTruncated(FileObject->SectionObjectPointer,
(PLARGE_INTEGER)&AllocationSize))
+        {
+            DPRINT1("Can't truncate a memory-mapped file!\n");
+            return STATUS_USER_MAPPED_FILE;
+        }
+    }
+
     if (AttrContext->Record.IsNonResident)
     {
         ULONG BytesPerCluster = Fcb->Vcb->NtfsInfo.BytesPerCluster;
@@ -238,28 +296,59 @@ SetAttributeDataLength(PFILE_OBJECT FileObject,
         AttrContext->Record.NonResident.DataSize = DataSize->QuadPart;
         AttrContext->Record.NonResident.InitializedSize = DataSize->QuadPart;
 
-        Fcb->RFCB.FileSize = *DataSize;
-        Fcb->RFCB.ValidDataLength = *DataSize;
+        // copy the attribute record back into the FileRecord
+        RtlCopyMemory((PCHAR)FileRecord + AttrOffset, &AttrContext->Record,
AttrContext->Record.Length);
+    }
+    else
+    {
+        // resident attribute
 
-        DPRINT("Data Size: %I64u\n", Fcb->RFCB.FileSize.QuadPart);
+        // find the next attribute
+        ULONG NextAttributeOffset = AttrOffset + AttrContext->Record.Length;
+        PNTFS_ATTR_RECORD NextAttribute = (PNTFS_ATTR_RECORD)((PCHAR)FileRecord +
NextAttributeOffset);
 
         //NtfsDumpFileAttributes(Fcb->Vcb, FileRecord);
 
-        // copy the attribute back into the FileRecord
-        RtlCopyMemory((PCHAR)FileRecord + AttrOffset, &AttrContext->Record,
AttrContext->Record.Length);
-
-        //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);
 
-        // write the updated file record back to disk
-        UpdateFileRecord(Fcb->Vcb, Fcb->MFTIndex, FileRecord);
+                if (MaxValueLength < DataSize->LowPart || NextAttribute->Type !=
AttributeEnd)
+                {
+                    DPRINT1("FIXME: Need to convert attribute to
non-resident!\n");
+                    return STATUS_NOT_IMPLEMENTED;
+                }
+            }
+        }
+        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;
+            }
+        }
 
-        CcSetFileSizes(FileObject, (PCC_FILE_SIZES)&Fcb->RFCB.AllocationSize);
+        InternalSetResidentAttributeLength(AttrContext, FileRecord, AttrOffset,
DataSize->LowPart);
     }
-    else
+
+    //NtfsDumpFileAttributes(Fcb->Vcb, FileRecord);
+
+    // write the updated file record back to disk
+    Status = UpdateFileRecord(Fcb->Vcb, Fcb->MFTIndex, FileRecord);
+
+    if (NT_SUCCESS(Status))
     {
-        // we can't yet handle resident attributes
-        DPRINT1("FixMe: Can't handle increasing length of resident
attribute\n");
-        return STATUS_NOT_IMPLEMENTED;
+        Fcb->RFCB.FileSize = *DataSize;
+        Fcb->RFCB.ValidDataLength = *DataSize;
+        CcSetFileSizes(FileObject, (PCC_FILE_SIZES)&Fcb->RFCB.AllocationSize);
     }
 
     return STATUS_SUCCESS;
@@ -501,29 +590,76 @@ WriteAttribute(PDEVICE_EXTENSION Vcb,
 
     DPRINT("WriteAttribute(%p, %p, %I64u, %p, %lu, %p)\n", Vcb, Context,
Offset, Buffer, Length, RealLengthWritten);
 
+    *RealLengthWritten = 0;
+
     // is this a resident attribute?
     if (!Context->Record.IsNonResident)
     {
-        DPRINT1("FIXME: Writing to resident NTFS records (small files) is not
supported at this time.\n");
-        // (TODO: This should be really easy to implement)
+        ULONG AttributeOffset;
+        PNTFS_ATTR_CONTEXT FoundContext;
+        PFILE_RECORD_HEADER FileRecord;
 
-        /* LeftOver code from ReadAttribute(), may be helpful:
-        if (Offset > Context->Record.Resident.ValueLength)
-        return 0;
         if (Offset + Length > Context->Record.Resident.ValueLength)
-        Length = (ULONG)(Context->Record.Resident.ValueLength - Offset);
-        RtlCopyMemory(Buffer, (PCHAR)&Context->Record +
Context->Record.Resident.ValueOffset + Offset, Length);
-        return Length;*/
+        {
+            DPRINT1("DRIVER ERROR: Attribute is too small!\n");
+            return STATUS_INVALID_PARAMETER;
+        }
+
+        FileRecord = ExAllocatePoolWithTag(NonPagedPool,
Vcb->NtfsInfo.BytesPerFileRecord, TAG_NTFS);
+
+        if (!FileRecord)
+        {
+            DPRINT1("Error: Couldn't allocate file record!\n");
+            return STATUS_NO_MEMORY;
+        }
+
+        // read the file record
+        ReadFileRecord(Vcb, Context->FileMFTIndex, FileRecord);
 
-        return STATUS_NOT_IMPLEMENTED;	// until we implement it
+        // find where to write the attribute data to
+        Status = FindAttribute(Vcb, FileRecord,
+                               Context->Record.Type,
+                               (PCWSTR)((PCHAR)&Context->Record +
Context->Record.NameOffset),
+                               Context->Record.NameLength,
+                               &FoundContext,
+                               &AttributeOffset);
+
+        if (!NT_SUCCESS(Status))
+        {
+            DPRINT1("ERROR: Couldn't find matching attribute!\n");
+            ExFreePoolWithTag(FileRecord, TAG_NTFS);
+            return Status;
+        }
+
+        DPRINT("Offset: %I64u, AttributeOffset: %u, ValueOffset: %u\n", Offset,
AttributeOffset, Context->Record.Resident.ValueLength);
+        Offset += AttributeOffset + Context->Record.Resident.ValueOffset;
+        
+        if (Offset + Length > Vcb->NtfsInfo.BytesPerFileRecord)
+        {
+            DPRINT1("DRIVER ERROR: Data being written extends past end of file
record!\n");
+            ReleaseAttributeContext(FoundContext);
+            ExFreePoolWithTag(FileRecord, TAG_NTFS);
+            return STATUS_INVALID_PARAMETER;
+        }
+
+        // copy the data being written into the file record
+        RtlCopyMemory((PCHAR)FileRecord + Offset, Buffer, Length);
+
+        Status = UpdateFileRecord(Vcb, Context->FileMFTIndex, FileRecord);
+
+        ReleaseAttributeContext(FoundContext);
+        ExFreePoolWithTag(FileRecord, TAG_NTFS);
+
+        if (NT_SUCCESS(Status))
+            *RealLengthWritten = Length;
+
+        return Status;
     }
 
     // This is a non-resident attribute.
 
     // I. Find the corresponding start data run.	
 
-    *RealLengthWritten = 0;
-
     // FIXME: Cache seems to be non-working. Disable it for now
     //if(Context->CacheRunOffset <= Offset && Offset <
Context->CacheRunOffset + Context->CacheRunLength * Volume->ClusterSize)
     /*if (0)
@@ -718,6 +854,7 @@ ReadFileRecord(PDEVICE_EXTENSION Vcb,
     }
 
     /* Apply update sequence array fixups. */
+    DPRINT("Sequence number: %u\n", file->SequenceNumber);
     return FixupUpdateSequenceArray(Vcb, &file->Ntfs);
 }
 
@@ -948,8 +1085,6 @@ UpdateFileRecord(PDEVICE_EXTENSION Vcb,
     // write the file record to the master file table
     Status = WriteAttribute(Vcb, Vcb->MFTContext, index *
Vcb->NtfsInfo.BytesPerFileRecord, (const PUCHAR)file,
Vcb->NtfsInfo.BytesPerFileRecord, &BytesWritten);
 
-    // TODO: Update MFT mirror
-
     if (!NT_SUCCESS(Status))
     {
         DPRINT1("UpdateFileRecord failed: %I64u written, %u expected\n",
BytesWritten, Vcb->NtfsInfo.BytesPerFileRecord);
diff --git a/drivers/filesystems/ntfs/ntfs.h b/drivers/filesystems/ntfs/ntfs.h
index 66cb37f4bd..238e6d5b2d 100644
--- a/drivers/filesystems/ntfs/ntfs.h
+++ b/drivers/filesystems/ntfs/ntfs.h
@@ -175,6 +175,10 @@ typedef enum
     AttributeEnd = 0xFFFFFFFF
 } ATTRIBUTE_TYPE, *PATTRIBUTE_TYPE;
 
+// FILE_RECORD_END seems to follow AttributeEnd in every file record starting with
$Quota.
+// No clue what data is being represented here.
+#define FILE_RECORD_END              0x11477982 
+
 #define NTFS_FILE_MFT                0
 #define NTFS_FILE_MFTMIRR            1
 #define NTFS_FILE_LOGFILE            2
@@ -433,6 +437,7 @@ typedef struct _NTFS_ATTR_CONTEXT
     ULONGLONG            CacheRunLength;
     LONGLONG            CacheRunLastLCN;
     ULONGLONG            CacheRunCurrentOffset;
+    ULONGLONG           FileMFTIndex;
     NTFS_ATTR_RECORD    Record;
 } NTFS_ATTR_CONTEXT, *PNTFS_ATTR_CONTEXT;
 
diff --git a/drivers/filesystems/ntfs/volinfo.c b/drivers/filesystems/ntfs/volinfo.c
index df3af4989a..0a54cf73b8 100644
--- a/drivers/filesystems/ntfs/volinfo.c
+++ b/drivers/filesystems/ntfs/volinfo.c
@@ -116,7 +116,6 @@ NtfsAllocateClusters(PDEVICE_EXTENSION DeviceExt,
     ULONGLONG BitmapDataSize;
     PCHAR BitmapData;
     ULONGLONG FreeClusters = 0;
-    ULONG Read = 0;
     RTL_BITMAP Bitmap;
 
     DPRINT1("NtfsAllocateClusters(%p, %lu, %lu, %p, %p)\n", DeviceExt,
FirstDesiredCluster, DesiredClusters, FirstAssignedCluster, AssignedClusters);
@@ -158,7 +157,7 @@ NtfsAllocateClusters(PDEVICE_EXTENSION DeviceExt,
     DPRINT1("Total clusters in bitmap: %I64x\n", BitmapDataSize * 8);
     DPRINT1("Diff in size: %I64d B\n", ((BitmapDataSize * 8) -
DeviceExt->NtfsInfo.ClusterCount) * DeviceExt->NtfsInfo.SectorsPerCluster *
DeviceExt->NtfsInfo.BytesPerSector);
 
-    ReadAttribute(DeviceExt, DataContext, Read, (PCHAR)((ULONG_PTR)BitmapData + Read),
(ULONG)BitmapDataSize);
+    ReadAttribute(DeviceExt, DataContext, 0, (PCHAR)BitmapData, (ULONG)BitmapDataSize);
 
     RtlInitializeBitMap(&Bitmap, (PULONG)BitmapData,
DeviceExt->NtfsInfo.ClusterCount);
     FreeClusters = RtlNumberOfClearBits(&Bitmap);