[pschweitzer] 65586: [NTFS] - Implement NtfsReadFCBAttribute() which is responsible for reading an attribute from a file which is referenced by its FCB. It will first read the file record in the MF...

Author: pschweitzer
Date: Sun Dec  7 20:59:45 2014
New Revision: 65586

URL: http://svn.reactos.org/svn/reactos?rev=65586&view=rev
Log:
[NTFS]
- Implement NtfsReadFCBAttribute() which is responsible for reading an attribute from a file which is referenced by its FCB. It will first read the file record in the MFT and then read the attribute, if found.
- Use NtfsReadFCBAttribute() to implement support for reparse point in NtfsCreateFile(). Once a reparse point is found, we attempt to open its data. Given their layout, we directly hand them to the Io manager. Just make sure that we return something consistent on disk. Only handle IO_REPARSE_TAG_MOUNT_POINT so far.
Next question to answer is: what to do when a reparse point is encountered during path traversal?

Modified:
    trunk/reactos/drivers/filesystems/ntfs/create.c
    trunk/reactos/drivers/filesystems/ntfs/fcb.c
    trunk/reactos/drivers/filesystems/ntfs/ntfs.h

Modified: trunk/reactos/drivers/filesystems/ntfs/create.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/filesystems/ntfs/cr...
==============================================================================
--- trunk/reactos/drivers/filesystems/ntfs/create.c	[iso-8859-1] (original)
+++ trunk/reactos/drivers/filesystems/ntfs/create.c	[iso-8859-1] Sun Dec  7 20:59:45 2014
@@ -245,21 +245,43 @@
             return STATUS_NOT_A_DIRECTORY;
         }

-        /* Properly handle reparse points:
-         * - likely overwrite FO name
-         * - return STATUS_REPARSE to IO manager
-         * - Do we have to attach reparse data to Irp->Tail.Overlay.AuxiliaryBuffer?
-         * See: http://www.osronline.com/showThread.cfm?link=6623
-         *
+        /*
          * If it is a reparse point & FILE_OPEN_REPARSE_POINT, then allow opening it
          * as a normal file.
+         * Otherwise, attempt to read reparse data and hand them to the Io manager
+         * with status reparse to force a reparse.
          */
         if (NtfsFCBIsReparsePoint(Fcb) &&
             ((RequestedOptions & FILE_OPEN_REPARSE_POINT) != FILE_OPEN_REPARSE_POINT))
         {
-            DPRINT1("Reparse point not handled!\n");
-            NtfsCloseFile(DeviceExt, FileObject);
-            return STATUS_NOT_IMPLEMENTED;
+            if (Fcb->Entry.Extended.ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
+            {
+                Status = NtfsReadFCBAttribute(DeviceExt, Fcb,
+                                              AttributeReparsePoint, L"", 0,
+                                              (PVOID *)&Irp->Tail.Overlay.AuxiliaryBuffer);
+                if (NT_SUCCESS(Status))
+                {
+                    PREPARSE_DATA_BUFFER ReparseData;
+
+                    ReparseData = (PREPARSE_DATA_BUFFER)Irp->Tail.Overlay.AuxiliaryBuffer;
+                    if (ReparseData->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
+                    {
+                        Status = STATUS_REPARSE;
+                    }
+                    else
+                    {
+                        Status = STATUS_FILE_CORRUPT_ERROR;
+                        ExFreePoolWithTag(ReparseData, TAG_NTFS);
+                    }
+                }
+            }
+            else
+            {
+                Status = STATUS_NOT_IMPLEMENTED;
+            }
+
+            NtfsCloseFile(DeviceExt, FileObject);
+            return Status;
         }

/* HUGLY HACK: remain RO so far... */

Modified: trunk/reactos/drivers/filesystems/ntfs/fcb.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/filesystems/ntfs/fc...
==============================================================================
--- trunk/reactos/drivers/filesystems/ntfs/fcb.c	[iso-8859-1] (original)
+++ trunk/reactos/drivers/filesystems/ntfs/fcb.c	[iso-8859-1] Sun Dec  7 20:59:45 2014
@@ -646,4 +646,57 @@
     return STATUS_SUCCESS;
 }

+
+NTSTATUS
+NtfsReadFCBAttribute(PNTFS_VCB Vcb,
+                     PNTFS_FCB pFCB,
+                     ULONG Type, 
+                     PCWSTR Name,
+                     ULONG NameLength,
+                     PVOID * Data)
+{
+    NTSTATUS Status;
+    PFILE_RECORD_HEADER FileRecord;
+    PNTFS_ATTR_CONTEXT AttrCtxt;
+    ULONGLONG AttrLength;
+
+    FileRecord = ExAllocatePoolWithTag(NonPagedPool,
+                                       Vcb->NtfsInfo.BytesPerFileRecord,
+                                       TAG_NTFS);
+    if (FileRecord == NULL)
+    {
+        return STATUS_INSUFFICIENT_RESOURCES;
+    }
+
+    Status = ReadFileRecord(Vcb, NTFS_FILE_BITMAP, FileRecord);
+    if (!NT_SUCCESS(Status))
+    {
+        ExFreePoolWithTag(FileRecord, TAG_NTFS);
+        return Status;
+    }
+
+    Status = FindAttribute(Vcb, FileRecord, Type, Name, NameLength, &AttrCtxt);
+    if (!NT_SUCCESS(Status))
+    {
+        ExFreePoolWithTag(FileRecord, TAG_NTFS);
+        return Status;
+    }
+
+    AttrLength = AttributeDataLength(&AttrCtxt->Record);
+    *Data = ExAllocatePoolWithTag(NonPagedPool, AttrLength, TAG_NTFS);
+    if (*Data == NULL)
+    {
+        ReleaseAttributeContext(AttrCtxt);
+        ExFreePoolWithTag(FileRecord, TAG_NTFS);
+        return STATUS_INSUFFICIENT_RESOURCES;
+    }
+
+    ReadAttribute(Vcb, AttrCtxt, 0, *Data, AttrLength);
+
+    ReleaseAttributeContext(AttrCtxt);
+    ExFreePoolWithTag(FileRecord, TAG_NTFS);
+
+    return STATUS_SUCCESS;
+}
+
 /* EOF */

Modified: trunk/reactos/drivers/filesystems/ntfs/ntfs.h
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/filesystems/ntfs/nt...
==============================================================================
--- trunk/reactos/drivers/filesystems/ntfs/ntfs.h	[iso-8859-1] (original)
+++ trunk/reactos/drivers/filesystems/ntfs/ntfs.h	[iso-8859-1] Sun Dec  7 20:59:45 2014
@@ -615,6 +615,14 @@
                   PNTFS_FCB *pFCB,
                   const PWSTR pFileName);

+NTSTATUS
+NtfsReadFCBAttribute(PNTFS_VCB Vcb,
+                     PNTFS_FCB pFCB,
+                     ULONG Type, 
+                     PCWSTR Name,
+                     ULONG NameLength,
+                     PVOID * Data);
+

/* finfo.c */