[ros-diffs] [fireball] 58889: [FSRTL] - Start bringing sanity to FSRTL Large MCB implementation: * Get rid of the GET_LIST_HEAD macro and define a proper private struct to access its members. That's much more ...

Author: fireball
Date: Mon Apr 29 10:10:44 2013
New Revision: 58889

URL: http://svn.reactos.org/svn/reactos?rev=58889&view=rev
Log:
[FSRTL]
- Start bringing sanity to FSRTL Large MCB implementation:
 * Get rid of the GET_LIST_HEAD macro and define a proper private struct to access its
members. That's much more flexible,and that's how it's usually done in
hundreds of other places in the kernel. Otherwise we might just forget about structs and
invent macros to access individual virtual fields in a byte array :)
 * Going through the code (first, preliminary pass) and putting helper debug prints,
especially when the code does not work as expected.
 * Move variables definitions to the beginning of the function (thus get rid of up to
local vars being redifined up to 3x times within a single function).

Modified:
    trunk/reactos/ntoskrnl/fsrtl/largemcb.c

Modified: trunk/reactos/ntoskrnl/fsrtl/largemcb.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/fsrtl/largemcb.c?…
==============================================================================
--- trunk/reactos/ntoskrnl/fsrtl/largemcb.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/fsrtl/largemcb.c [iso-8859-1] Mon Apr 29 10:10:44 2013
@@ -16,8 +16,6 @@
 
 /* GLOBALS *******************************************************************/
 
-#define GET_LIST_HEAD(x) ((PLIST_ENTRY)(&((PRTL_GENERIC_TABLE)x)[1]))
-
 PAGED_LOOKASIDE_LIST FsRtlFirstMappingLookasideList;
 NPAGED_LOOKASIDE_LIST FsRtlFastMutexLookasideList;
 
@@ -28,6 +26,21 @@
 	LARGE_INTEGER StartingLbn;
 	LIST_ENTRY Sequence;
 } LARGE_MCB_MAPPING_ENTRY, *PLARGE_MCB_MAPPING_ENTRY;
+
+typedef struct _LARGE_MCB_MAPPING
+{
+    RTL_GENERIC_TABLE Table;
+    LIST_ENTRY SequenceList;
+} LARGE_MCB_MAPPING, *PLARGE_MCB_MAPPING;
+
+typedef struct _BASE_MCB_INTERNAL {
+    ULONG MaximumPairCount;
+    ULONG PairCount;
+    USHORT PoolType;
+    USHORT Flags;
+    PLARGE_MCB_MAPPING Mapping;
+} BASE_MCB_INTERNAL, *PBASE_MCB_INTERNAL;
+
 
 static PVOID NTAPI McbMappingAllocate(PRTL_GENERIC_TABLE Table, CLONG Bytes)
 {
@@ -63,11 +76,12 @@
  */
 BOOLEAN
 NTAPI
-FsRtlAddBaseMcbEntry(IN PBASE_MCB Mcb,
+FsRtlAddBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
                      IN LONGLONG Vbn,
                      IN LONGLONG Lbn,
                      IN LONGLONG SectorCount)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	LARGE_MCB_MAPPING_ENTRY Node;
 	PLARGE_MCB_MAPPING_ENTRY Existing = NULL;
 	BOOLEAN NewElement = FALSE;
@@ -79,8 +93,7 @@
 	while (!NewElement)
 	{
 		DPRINT("Inserting %x:%x\n", Node.RunStartVbn.LowPart,
Node.SectorCount.LowPart);
-		Existing = RtlInsertElementGenericTable
-			(Mcb->Mapping, &Node, sizeof(Node), &NewElement);
+		Existing = RtlInsertElementGenericTable(&Mcb->Mapping->Table, &Node,
sizeof(Node), &NewElement);
 		DPRINT("Existing %x\n", Existing);
 		if (!Existing) break;
 
@@ -89,8 +102,7 @@
 		{
 			// We merge the existing runs
 			LARGE_INTEGER StartVbn, FinalVbn;
-			DPRINT("Existing: %x:%x\n", 
-				   Existing->RunStartVbn.LowPart, Node.SectorCount.LowPart);
+			DPRINT("Existing: %x:%x\n", Existing->RunStartVbn.LowPart,
Node.SectorCount.LowPart);
 			if (Existing->RunStartVbn.QuadPart < Node.RunStartVbn.QuadPart)
 			{
 				StartVbn = Existing->RunStartVbn;
@@ -116,7 +128,7 @@
 			Node.RunStartVbn.QuadPart = StartVbn.QuadPart;
 			Node.SectorCount.QuadPart = FinalVbn.QuadPart - StartVbn.QuadPart;
 			RemoveHeadList(&Existing->Sequence);
-			RtlDeleteElementGenericTable(Mcb->Mapping, Existing);
+			RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Existing);
 			Mcb->PairCount--;
 		}
 		else
@@ -124,7 +136,7 @@
 			DPRINT("Mapping added %x\n", Existing);
 			Mcb->MaximumPairCount++;
 			Mcb->PairCount++;
-			InsertHeadList(GET_LIST_HEAD(Mcb->Mapping), &Existing->Sequence);
+			InsertHeadList(&Mcb->Mapping->SequenceList, &Existing->Sequence);
 		}
 	}
 
@@ -163,20 +175,21 @@
  */
 BOOLEAN
 NTAPI
-FsRtlGetNextBaseMcbEntry(IN PBASE_MCB Mcb,
+FsRtlGetNextBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
                          IN ULONG RunIndex,
                          OUT PLONGLONG Vbn,
                          OUT PLONGLONG Lbn,
                          OUT PLONGLONG SectorCount)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	ULONG i = 0;
 	BOOLEAN Result = FALSE;
 	PLARGE_MCB_MAPPING_ENTRY Entry;
 	for (Entry = (PLARGE_MCB_MAPPING_ENTRY)
-			 RtlEnumerateGenericTable(Mcb->Mapping, TRUE);
+			 RtlEnumerateGenericTable(&Mcb->Mapping->Table, TRUE);
 		 Entry && i < RunIndex;
 		 Entry = (PLARGE_MCB_MAPPING_ENTRY)
-			 RtlEnumerateGenericTable(Mcb->Mapping, FALSE), i++);
+			 RtlEnumerateGenericTable(&Mcb->Mapping->Table, FALSE), i++);
 	if (Entry)
 	{
 		Result = TRUE;
@@ -224,9 +237,10 @@
  */
 VOID
 NTAPI
-FsRtlInitializeBaseMcb(IN PBASE_MCB Mcb,
+FsRtlInitializeBaseMcb(IN PBASE_MCB OpaqueMcb,
                        IN POOL_TYPE PoolType)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
     Mcb->PairCount = 0;
 
     if (PoolType == PagedPool)
@@ -236,19 +250,19 @@
     else
     {
         Mcb->Mapping = ExAllocatePoolWithTag(PoolType |
POOL_RAISE_IF_ALLOCATION_FAILURE,
-											 sizeof(RTL_GENERIC_TABLE) + sizeof(LIST_ENTRY),
+											 sizeof(LARGE_MCB_MAPPING),
                                              'FSBC');
     }
 
     Mcb->PoolType = PoolType;
     Mcb->MaximumPairCount = MAXIMUM_PAIR_COUNT;
 	RtlInitializeGenericTable
-		(Mcb->Mapping,
+		(&Mcb->Mapping->Table,
 		 (PRTL_GENERIC_COMPARE_ROUTINE)McbMappingCompare,
 		 McbMappingAllocate,
 		 McbMappingFree,
 		 Mcb);
-	InitializeListHead(GET_LIST_HEAD(Mcb->Mapping));
+	InitializeListHead(&Mcb->Mapping->SequenceList);
 }
 
 /*
@@ -288,7 +302,7 @@
                                    NULL,
                                    NULL,
                                    POOL_RAISE_IF_ALLOCATION_FAILURE,
-								   sizeof(RTL_GENERIC_TABLE) + sizeof(LIST_ENTRY),
+								   sizeof(LARGE_MCB_MAPPING),
                                    IFS_POOL_TAG,
                                    0); /* FIXME: Should be 4 */
 
@@ -307,7 +321,7 @@
  */
 BOOLEAN
 NTAPI
-FsRtlLookupBaseMcbEntry(IN PBASE_MCB Mcb,
+FsRtlLookupBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
                         IN LONGLONG Vbn,
                         OUT PLONGLONG Lbn OPTIONAL,
                         OUT PLONGLONG SectorCountFromLbn OPTIONAL,
@@ -315,6 +329,7 @@
                         OUT PLONGLONG SectorCountFromStartingLbn OPTIONAL,
                         OUT PULONG Index OPTIONAL)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	BOOLEAN Result = FALSE;
 	LARGE_MCB_MAPPING_ENTRY ToLookup;
 	PLARGE_MCB_MAPPING_ENTRY Entry;
@@ -322,13 +337,15 @@
 	ToLookup.RunStartVbn.QuadPart = Vbn;
 	ToLookup.SectorCount.QuadPart = 1;
 
-	Entry = RtlLookupElementGenericTable(Mcb->Mapping, &ToLookup);
+	Entry = RtlLookupElementGenericTable(&Mcb->Mapping->Table, &ToLookup);
+    DPRINT("Entry %p\n", Entry);
 	if (!Entry)
 	{
 		// Find out if we have a following entry.  The spec says we should return
 		// found with Lbn == -1 when we're beneath the largest map.
 		ToLookup.SectorCount.QuadPart = (1ull<<62) - ToLookup.RunStartVbn.QuadPart;
-		Entry = RtlLookupElementGenericTable(Mcb->Mapping, &ToLookup);
+		Entry = RtlLookupElementGenericTable(&Mcb->Mapping->Table, &ToLookup);
+        DPRINT("Entry %p\n", Entry);
 		if (Entry)
 		{
 			Result = TRUE;
@@ -349,7 +366,7 @@
 		if (StartingLbn) *StartingLbn = Entry->StartingLbn.QuadPart;
 		if (SectorCountFromStartingLbn) *SectorCountFromStartingLbn =
Entry->SectorCount.QuadPart;
 	}
-	
+	DPRINT("Done\n");
     return Result;
 }
 
@@ -395,13 +412,14 @@
                                     IN OUT PLONGLONG LargeLbn,
                                     IN OUT PULONG Index)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	ULONG i = 0;
 	BOOLEAN Result = FALSE;
 	PLIST_ENTRY ListEntry;
 	PLARGE_MCB_MAPPING_ENTRY Entry;
 	PLARGE_MCB_MAPPING_ENTRY CountEntry;
 
-	ListEntry = GET_LIST_HEAD(OpaqueMcb->Mapping);
+	ListEntry = &Mcb->Mapping->SequenceList;
 	if (!IsListEmpty(ListEntry))
 	{
 		Entry = CONTAINING_RECORD(ListEntry->Flink, LARGE_MCB_MAPPING_ENTRY, Sequence);
@@ -409,10 +427,10 @@
 		*LargeVbn = Entry->RunStartVbn.QuadPart;
 		*LargeLbn = Entry->StartingLbn.QuadPart;
 
-		for (i = 0, CountEntry = RtlEnumerateGenericTable(OpaqueMcb->Mapping, TRUE);
+		for (i = 0, CountEntry = RtlEnumerateGenericTable(&Mcb->Mapping->Table,
TRUE);
 			 CountEntry != Entry;
-			 CountEntry = RtlEnumerateGenericTable(OpaqueMcb->Mapping, FALSE));
-
+			 CountEntry = RtlEnumerateGenericTable(&Mcb->Mapping->Table, FALSE));
+        DPRINT1("Most probably we are returning shit now\n");
 		*Index = i;
 	}
 
@@ -450,15 +468,16 @@
  */
 BOOLEAN
 NTAPI
-FsRtlLookupLastBaseMcbEntry(IN PBASE_MCB Mcb,
+FsRtlLookupLastBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
                             OUT PLONGLONG Vbn,
                             OUT PLONGLONG Lbn)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	BOOLEAN Result = FALSE;
 	PLIST_ENTRY ListEntry;
 	PLARGE_MCB_MAPPING_ENTRY Entry;
 
-	ListEntry = GET_LIST_HEAD(Mcb->Mapping);
+	ListEntry = &Mcb->Mapping->SequenceList;
 	if (!IsListEmpty(ListEntry))
 	{
 		Entry = CONTAINING_RECORD(ListEntry->Flink, LARGE_MCB_MAPPING_ENTRY, Sequence);
@@ -532,27 +551,32 @@
  */
 BOOLEAN
 NTAPI
-FsRtlRemoveBaseMcbEntry(IN PBASE_MCB Mcb,
+FsRtlRemoveBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
                         IN LONGLONG Vbn,
                         IN LONGLONG SectorCount)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	LARGE_MCB_MAPPING_ENTRY Node;
+	LARGE_MCB_MAPPING_ENTRY NewElement;
 	PLARGE_MCB_MAPPING_ENTRY Element;
+	PLARGE_MCB_MAPPING_ENTRY Reinserted, Inserted;
+	LARGE_INTEGER StartHole, EndHole, EndRun;
 
 	Node.RunStartVbn.QuadPart = Vbn;
 	Node.SectorCount.QuadPart = SectorCount;
 
-	while ((Element = RtlLookupElementGenericTable(Mcb->Mapping, &Node)))
-	{
+	while ((Element = RtlLookupElementGenericTable(&Mcb->Mapping->Table,
&Node)))
+	{
+        DPRINT1("Node.RunStartVbn %I64d, Node.SectorCount %I64d\n",
Node.RunStartVbn.QuadPart, Node.SectorCount.QuadPart);
+        DPRINT1("Element %p, .RunStartVbn %I64d, .SectorCount %I64d\n",
Element, Element->RunStartVbn.QuadPart, Element->SectorCount.QuadPart);
 		// Must split
 		if (Element->RunStartVbn.QuadPart < Node.RunStartVbn.QuadPart &&
 			Element->SectorCount.QuadPart > Node.SectorCount.QuadPart)
 		{
 			LARGE_MCB_MAPPING_ENTRY Upper, Reinsert;
-			PLARGE_MCB_MAPPING_ENTRY Reinserted, Inserted;
-			LARGE_INTEGER StartHole = Node.RunStartVbn;
-			LARGE_INTEGER EndHole;
+			StartHole = Node.RunStartVbn;
 			EndHole.QuadPart = Node.RunStartVbn.QuadPart + Node.SectorCount.QuadPart;
+
 			Upper.RunStartVbn.QuadPart = EndHole.QuadPart;
 			Upper.StartingLbn.QuadPart = 
 				Element->StartingLbn.QuadPart + 
@@ -565,57 +589,50 @@
 			Reinsert.SectorCount.QuadPart = 
 				Element->RunStartVbn.QuadPart - StartHole.QuadPart;
 			RemoveEntryList(&Element->Sequence);
-			RtlDeleteElementGenericTable(Mcb->Mapping, Element);
+			RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Element);
 			Mcb->PairCount--;
 
-			Reinserted = RtlInsertElementGenericTable
-				(Mcb->Mapping, &Reinsert, sizeof(Reinsert), NULL);
-			InsertHeadList(GET_LIST_HEAD(Mcb->Mapping), &Reinserted->Sequence);
+			Reinserted = RtlInsertElementGenericTable(&Mcb->Mapping->Table,
&Reinsert, sizeof(Reinsert), NULL);
+			InsertHeadList(&Mcb->Mapping->SequenceList, &Reinserted->Sequence);
 			Mcb->PairCount++;
 			
-			Inserted = RtlInsertElementGenericTable
-				(Mcb->Mapping, &Upper, sizeof(Upper), NULL);
-			InsertHeadList(GET_LIST_HEAD(Mcb->Mapping), &Inserted->Sequence);
+			Inserted = RtlInsertElementGenericTable(&Mcb->Mapping->Table, &Upper,
sizeof(Upper), NULL);
+			InsertHeadList(&Mcb->Mapping->SequenceList, &Inserted->Sequence);
 			Mcb->PairCount++;
 		}
 		else if (Element->RunStartVbn.QuadPart < Node.RunStartVbn.QuadPart)
 		{
-			LARGE_MCB_MAPPING_ENTRY NewElement;
-			PLARGE_MCB_MAPPING_ENTRY Reinserted;
-			LARGE_INTEGER StartHole = Node.RunStartVbn;
+			StartHole = Node.RunStartVbn;
 			NewElement.RunStartVbn = Element->RunStartVbn;
 			NewElement.StartingLbn = Element->StartingLbn;
 			NewElement.SectorCount.QuadPart = StartHole.QuadPart -
Element->StartingLbn.QuadPart;
 
 			RemoveEntryList(&Element->Sequence);
-			RtlDeleteElementGenericTable(Mcb->Mapping, Element);
+			RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Element);
 			Mcb->PairCount--;
 			
-			Reinserted = RtlInsertElementGenericTable
-				(Mcb->Mapping, &NewElement, sizeof(NewElement), NULL);
-			InsertHeadList(GET_LIST_HEAD(Mcb->Mapping), &Reinserted->Sequence);
-			Mcb->PairCount++;			
+			Reinserted = RtlInsertElementGenericTable(&Mcb->Mapping->Table,
&NewElement, sizeof(NewElement), NULL);
+			InsertHeadList(&Mcb->Mapping->SequenceList, &Reinserted->Sequence);
+			Mcb->PairCount++;
 		}
 		else
 		{
-			LARGE_MCB_MAPPING_ENTRY NewElement;
-			PLARGE_MCB_MAPPING_ENTRY Reinserted;
-			LARGE_INTEGER EndHole = Element->RunStartVbn;
-			LARGE_INTEGER EndRun;
+			EndHole = Element->RunStartVbn;
 			EndRun.QuadPart = Element->RunStartVbn.QuadPart +
Element->SectorCount.QuadPart;
 			NewElement.RunStartVbn = EndHole;
-			NewElement.StartingLbn.QuadPart = Element->StartingLbn.QuadPart + 
-				(EndHole.QuadPart - Element->RunStartVbn.QuadPart);
+			NewElement.StartingLbn.QuadPart = Element->StartingLbn.QuadPart + (EndHole.QuadPart
- Element->RunStartVbn.QuadPart);
 			NewElement.SectorCount.QuadPart = EndRun.QuadPart - EndHole.QuadPart;
 
 			RemoveEntryList(&Element->Sequence);
-			RtlDeleteElementGenericTable(Mcb->Mapping, Element);
+			RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Element);
 			Mcb->PairCount--;
 			
-			Reinserted = RtlInsertElementGenericTable
-				(Mcb->Mapping, &NewElement, sizeof(NewElement), NULL);
-			InsertHeadList(GET_LIST_HEAD(Mcb->Mapping), &Reinserted->Sequence);
-			Mcb->PairCount++;			
+			Reinserted = RtlInsertElementGenericTable(&Mcb->Mapping->Table,
&NewElement, sizeof(NewElement), NULL);
+			InsertHeadList(&Mcb->Mapping->SequenceList, &Reinserted->Sequence);
+			Mcb->PairCount++;
+
+            DPRINT1("Reinserted %p, .RunStartVbn %I64d, .SectorCount %I64d\n",
Reinserted, Reinserted->RunStartVbn.QuadPart, Reinserted->SectorCount.QuadPart);
+            DPRINT1("NewElement .RunStartVbn %I64d, .SectorCount %I64d\n",
NewElement.RunStartVbn.QuadPart, NewElement.SectorCount.QuadPart);
 		}
 	}
 
@@ -631,7 +648,7 @@
                          IN LONGLONG Vbn,
                          IN LONGLONG SectorCount)
 {
-	DPRINT("FsRtlRemoveLargeMcbEntry Mcb %x, Vbn %x, SectorCount %x\n", Mcb,
(ULONG)Vbn, (ULONG)SectorCount);
+	DPRINT("FsRtlRemoveLargeMcbEntry Mcb %x, Vbn %I64d, SectorCount %I64d\n", Mcb,
(ULONG)Vbn, (ULONG)SectorCount);
 
     KeAcquireGuardedMutex(Mcb->GuardedMutex);
     FsRtlRemoveBaseMcbEntry(&(Mcb->BaseMcb),
@@ -647,14 +664,15 @@
  */
 VOID
 NTAPI
-FsRtlResetBaseMcb(IN PBASE_MCB Mcb)
-{
+FsRtlResetBaseMcb(IN PBASE_MCB OpaqueMcb)
+{
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	PLARGE_MCB_MAPPING_ENTRY Element;
 
-	while (RtlNumberGenericTableElements(Mcb->Mapping) &&
-		   (Element = (PLARGE_MCB_MAPPING_ENTRY)RtlGetElementGenericTable(Mcb->Mapping,
0)))
-	{
-		RtlDeleteElementGenericTable(Mcb->Mapping, Element);
+	while (RtlNumberGenericTableElements(&Mcb->Mapping->Table) &&
+		   (Element =
(PLARGE_MCB_MAPPING_ENTRY)RtlGetElementGenericTable(&Mcb->Mapping->Table, 0)))
+	{
+		RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Element);
 	}
 
 	Mcb->PairCount = 0;
@@ -686,7 +704,7 @@
 #define MCB_BUMP_NO_MORE 0
 #define MCB_BUMP_AGAIN   1
 
-static ULONG NTAPI McbBump(PBASE_MCB Mcb, PLARGE_MCB_MAPPING_ENTRY FixedPart)
+static ULONG NTAPI McbBump(PBASE_MCB_INTERNAL Mcb, PLARGE_MCB_MAPPING_ENTRY FixedPart)
 {
 	LARGE_MCB_MAPPING_ENTRY Reimagined;
 	PLARGE_MCB_MAPPING_ENTRY Found = NULL;
@@ -694,7 +712,7 @@
 	DPRINT("McbBump %x (%x:%x)\n", Mcb, FixedPart->RunStartVbn.LowPart,
FixedPart->SectorCount.LowPart);
 
 	Reimagined = *FixedPart;
-	while ((Found = RtlLookupElementGenericTable(Mcb->Mapping, &Reimagined)))
+	while ((Found = RtlLookupElementGenericTable(&Mcb->Mapping->Table,
&Reimagined)))
 	{
 		Reimagined = *Found;
 		Reimagined.RunStartVbn.QuadPart = 
@@ -723,10 +741,11 @@
  */
 BOOLEAN
 NTAPI
-FsRtlSplitBaseMcb(IN PBASE_MCB Mcb,
+FsRtlSplitBaseMcb(IN PBASE_MCB OpaqueMcb,
                   IN LONGLONG Vbn,
                   IN LONGLONG Amount)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	ULONG Result;
 	LARGE_MCB_MAPPING_ENTRY Node;
 	PLARGE_MCB_MAPPING_ENTRY Existing = NULL;
@@ -734,7 +753,7 @@
 	Node.RunStartVbn.QuadPart = Vbn;
 	Node.SectorCount.QuadPart = 0;
 	
-	Existing = RtlLookupElementGenericTable(Mcb->Mapping, &Node);
+	Existing = RtlLookupElementGenericTable(&Mcb->Mapping->Table, &Node);
 
 	if (Existing)
 	{
@@ -765,21 +784,20 @@
 		{
 			Node = *Existing;
 			RemoveHeadList(&Existing->Sequence);
-			RtlDeleteElementGenericTable(Mcb->Mapping, Existing);
+			RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Existing);
 			Mcb->PairCount--;
 			
 			// Adjust the element we found.
 			Existing->SectorCount = LowerPart.SectorCount;
 
-			InsertedUpper = RtlInsertElementGenericTable
-				(Mcb->Mapping, &UpperPart, sizeof(UpperPart), NULL);
+			InsertedUpper = RtlInsertElementGenericTable(&Mcb->Mapping->Table,
&UpperPart, sizeof(UpperPart), NULL);
 			if (!InsertedUpper)
 			{
 				// Just make it like it was
 				Existing->SectorCount = Node.SectorCount;
 				return FALSE;
 			}
-			InsertHeadList(GET_LIST_HEAD(Mcb->Mapping), &InsertedUpper->Sequence);
+			InsertHeadList(&Mcb->Mapping->SequenceList,
&InsertedUpper->Sequence);
 			Mcb->PairCount++;
 		}
 		else
@@ -825,12 +843,13 @@
  */
 VOID
 NTAPI
-FsRtlTruncateBaseMcb(IN PBASE_MCB Mcb,
+FsRtlTruncateBaseMcb(IN PBASE_MCB OpaqueMcb,
                      IN LONGLONG Vbn)
 {
+    PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
 	if (!Vbn)
 	{
-		FsRtlResetBaseMcb(Mcb);
+		FsRtlResetBaseMcb(OpaqueMcb);
 	}
 	else
 	{
@@ -838,10 +857,10 @@
 		PLARGE_MCB_MAPPING_ENTRY Found;
 		Truncate.RunStartVbn.QuadPart = Vbn;
 		Truncate.SectorCount.QuadPart = (1ull<<62) - Truncate.RunStartVbn.QuadPart;
-		while ((Found = RtlLookupElementGenericTable(Mcb->Mapping, &Truncate)))
+		while ((Found = RtlLookupElementGenericTable(&Mcb->Mapping->Table,
&Truncate)))
 		{
 			RemoveEntryList(&Found->Sequence);
-			RtlDeleteElementGenericTable(Mcb->Mapping, Found);
+			RtlDeleteElementGenericTable(&Mcb->Mapping->Table, Found);
 			Mcb->PairCount--;
 		}
 	}