diff --git a/reactos/include/ddk/ntifs.h b/reactos/include/ddk/ntifs.h
index a0318e6b940..603531358c7 100644
--- a/reactos/include/ddk/ntifs.h
+++ b/reactos/include/ddk/ntifs.h
@@ -1639,6 +1639,65 @@ typedef struct _RTL_GENERIC_TABLE
     PVOID TableContext;
 } RTL_GENERIC_TABLE, *PRTL_GENERIC_TABLE;
 
+typedef struct _UNICODE_PREFIX_TABLE_ENTRY
+{
+    CSHORT NodeTypeCode;
+    CSHORT NameLength;
+    struct _UNICODE_PREFIX_TABLE_ENTRY *NextPrefixTree;
+    struct _UNICODE_PREFIX_TABLE_ENTRY *CaseMatch;
+    RTL_SPLAY_LINKS Links;
+    PUNICODE_STRING Prefix;
+} UNICODE_PREFIX_TABLE_ENTRY, *PUNICODE_PREFIX_TABLE_ENTRY;
+    
+typedef struct _UNICODE_PREFIX_TABLE
+{
+    CSHORT NodeTypeCode;
+    CSHORT NameLength;
+    PUNICODE_PREFIX_TABLE_ENTRY NextPrefixTree;
+    PUNICODE_PREFIX_TABLE_ENTRY LastNextEntry;
+} UNICODE_PREFIX_TABLE, *PUNICODE_PREFIX_TABLE;
+    
+NTSYSAPI
+VOID
+NTAPI
+RtlInitializeUnicodePrefix (
+    IN PUNICODE_PREFIX_TABLE PrefixTable
+);
+    
+NTSYSAPI
+BOOLEAN
+NTAPI
+RtlInsertUnicodePrefix (
+    IN PUNICODE_PREFIX_TABLE PrefixTable,
+    IN PUNICODE_STRING Prefix,
+    IN PUNICODE_PREFIX_TABLE_ENTRY PrefixTableEntry
+);
+    
+NTSYSAPI
+VOID
+NTAPI
+RtlRemoveUnicodePrefix (
+    IN PUNICODE_PREFIX_TABLE PrefixTable,
+    IN PUNICODE_PREFIX_TABLE_ENTRY PrefixTableEntry
+);
+
+NTSYSAPI
+PUNICODE_PREFIX_TABLE_ENTRY
+NTAPI
+RtlFindUnicodePrefix (
+    IN PUNICODE_PREFIX_TABLE PrefixTable,
+    IN PUNICODE_STRING FullName,
+    IN ULONG CaseInsensitiveIndex
+);
+    
+NTSYSAPI
+PUNICODE_PREFIX_TABLE_ENTRY
+NTAPI
+RtlNextUnicodePrefix (
+    IN PUNICODE_PREFIX_TABLE PrefixTable,
+    IN BOOLEAN Restart
+);
+
 #undef PRTL_GENERIC_COMPARE_ROUTINE
 #undef PRTL_GENERIC_ALLOCATE_ROUTINE
 #undef PRTL_GENERIC_FREE_ROUTINE
diff --git a/reactos/include/ddk/winddk.h b/reactos/include/ddk/winddk.h
index 6a9e8b8e51e..c41b093dc13 100644
--- a/reactos/include/ddk/winddk.h
+++ b/reactos/include/ddk/winddk.h
@@ -9205,12 +9205,11 @@ IoReuseIrp(
  *   IN PIRP  Irp,
  *   IN PDRIVER_CANCEL  CancelRoutine)
  */
-#define IoSetCancelRoutine(_Irp, \
-                           _CancelRoutine) \
-  ((PDRIVER_CANCEL) InterlockedExchangePointer( \
-    (PVOID *) &(_Irp)->CancelRoutine, (PVOID) (_CancelRoutine)))
-
-/*
+#define IoSetCancelRoutine( Irp, NewCancelRoutine ) (  \
+ InterlockedExchange( (PLONG)&(Irp)->CancelRoutine, (LONG)(NewCancelRoutine) ) )
+    
+    
+    /*
  * VOID
  * IoSetCompletionRoutine(
  *   IN PIRP  Irp,
diff --git a/reactos/ntoskrnl/io/iomgr/irp.c b/reactos/ntoskrnl/io/iomgr/irp.c
index 148babfcb75..146175f3a92 100644
--- a/reactos/ntoskrnl/io/iomgr/irp.c
+++ b/reactos/ntoskrnl/io/iomgr/irp.c
@@ -286,7 +286,7 @@ IopCompleteRequest(IN PKAPC Apc,
         if (Irp->Flags & IRP_DEALLOCATE_BUFFER)
         {
             /* Deallocate it */
-            ExFreePoolWithTag(Irp->AssociatedIrp.SystemBuffer, TAG_SYS_BUF);
+            ExFreePool(Irp->AssociatedIrp.SystemBuffer);
         }
     }
 
@@ -976,7 +976,7 @@ IoCancelIrp(IN PIRP Irp)
     Irp->Cancel = TRUE;
 
     /* Clear the cancel routine and get the old one */
-    CancelRoutine = IoSetCancelRoutine(Irp, NULL);
+    CancelRoutine = (PVOID)IoSetCancelRoutine(Irp, NULL);
     if (CancelRoutine)
     {
         /* We had a routine, make sure the IRP isn't completed */