[NTFS] - Fix some errors that break building in C89 mode, and remove an extraneous...

SplitBTree() - comment-out redundant code for finding the median key and improve comments.

svn path=/branches/GSoC_2016/NTFS/; revision=75727

diff --git a/drivers/filesystems/ntfs/btree.c b/drivers/filesystems/ntfs/btree.c
index bb745c5..9fb1b29 100644 (file)
--- a/drivers/filesystems/ntfs/btree.c
+++ b/drivers/filesystems/ntfs/btree.c
@@ -1139,7 +1139,7 @@ DemoteBTreeRoot(PB_TREE Tree)
 
 #ifndef NDEBUG
     DumpBTree(Tree);
-#endif;
+#endif
 
     return STATUS_SUCCESS;
 }
@@ -1779,7 +1779,7 @@ NtfsInsertKey(PB_TREE Tree,
 
 #ifndef NDEBUG
                     DumpBTree(Tree);
-#endif NDEBUG
+#endif
                 }
             }
             else
@@ -1880,6 +1880,9 @@ SplitBTreeNode(PB_TREE Tree,
 {
     ULONG MedianKeyIndex;
     PB_TREE_KEY LastKeyBeforeMedian, FirstKeyAfterMedian;
+    ULONG KeyCount;
+    ULONG HalfSize;
+    ULONG SizeSum;
     ULONG i;
 
     DPRINT1("SplitBTreeNode(%p, %p, %p, %p, %s) called\n",
@@ -1889,7 +1892,9 @@ SplitBTreeNode(PB_TREE Tree,
             NewRightHandSibling,
             CaseSensitive ? "TRUE" : "FALSE");
 
-    //DumpBTreeNode(Node, 0, 0);
+#ifndef NDEBUG
+    DumpBTreeNode(Node, 0, 0);
+#endif
 
     // Create the right hand sibling
     *NewRightHandSibling = ExAllocatePoolWithTag(NonPagedPool, sizeof(B_TREE_FILENAME_NODE), TAG_NTFS);
@@ -1901,20 +1906,29 @@ SplitBTreeNode(PB_TREE Tree,
     RtlZeroMemory(*NewRightHandSibling, sizeof(B_TREE_FILENAME_NODE));
     (*NewRightHandSibling)->DiskNeedsUpdating = TRUE;
 
+
+    // Find the last key before the median
+
+    // This is roughly how NTFS-3G calculates median, and it's not congruent with what Windows does:
+    /*
     // find the median key index
     MedianKeyIndex = (Node->KeyCount + 1) / 2;
     MedianKeyIndex--;
 
-    // Find the last key before the median
     LastKeyBeforeMedian = Node->FirstKey;
     for (i = 0; i < MedianKeyIndex - 1; i++)
-        LastKeyBeforeMedian = LastKeyBeforeMedian->NextKey;
+        LastKeyBeforeMedian = LastKeyBeforeMedian->NextKey;*/
+
+    // The method we'll use is a little bit closer to how Windows determines the median but it's not identical.
+    // What Windows does is actually more complicated than this, I think because Windows allocates more slack space to Odd-numbered
+    // Index Records, leaving less room for index entries in these records (I haven't discovered why this is done).
+    // (Neither Windows nor chkdsk complain if we choose a different median than Windows would have chosen, as our median will be in the ballpark)
 
     // Use size to locate the median key / index
-    ULONG HalfSize = 2016; // half the allocated size after subtracting the first index entry offset (TODO: MATH)
-    ULONG SizeSum = 0;
     LastKeyBeforeMedian = Node->FirstKey;
     MedianKeyIndex = 0;
+    HalfSize = 2016; // half the allocated size after subtracting the first index entry offset (TODO: MATH)
+    SizeSum = 0;
     for (i = 0; i < Node->KeyCount; i++)
     {
         SizeSum += LastKeyBeforeMedian->IndexEntry->Length;
@@ -1989,7 +2003,7 @@ SplitBTreeNode(PB_TREE Tree,
     // Update Node's KeyCount (remember to add 1 for the new dummy key)
     Node->KeyCount = MedianKeyIndex + 2;
 
-    ULONG KeyCount = CountBTreeKeys(Node->FirstKey);
+    KeyCount = CountBTreeKeys(Node->FirstKey);
     ASSERT(Node->KeyCount == KeyCount);
 
     // everything to the right of MedianKey becomes the right hand sibling of Node

diff --git a/drivers/filesystems/ntfs/mft.c b/drivers/filesystems/ntfs/mft.c
index c4328a0..9d96bad 100644 (file)
--- a/drivers/filesystems/ntfs/mft.c
+++ b/drivers/filesystems/ntfs/mft.c
@@ -2138,6 +2138,9 @@ NtfsAddFilenameToDirectory(PDEVICE_EXTENSION DeviceExt,
     ULONG MaxIndexRootSize;
     PB_TREE_KEY NewLeftKey;
     PB_TREE_FILENAME_NODE NewRightHandNode;
+    LARGE_INTEGER MinIndexRootSize;
+    ULONG NewMaxIndexRootSize;
+    ULONG NodeSize;
 
     // Allocate memory for the parent directory
     ParentFileRecord = ExAllocatePoolWithTag(NonPagedPool,
@@ -2287,7 +2290,6 @@ NtfsAddFilenameToDirectory(PDEVICE_EXTENSION DeviceExt,
     // This a bit hacky, but it seems to be functional.
 
     // Calculate the minimum size of the index root attribute, considering one dummy key and one VCN
-    LARGE_INTEGER MinIndexRootSize;
     MinIndexRootSize.QuadPart = sizeof(INDEX_ROOT_ATTRIBUTE) // size of the index root headers
                                 + 0x18; // Size of dummy key with a VCN for a subnode
     ASSERT(MinIndexRootSize.QuadPart % ATTR_RECORD_ALIGNMENT == 0);
@@ -2335,7 +2337,7 @@ NtfsAddFilenameToDirectory(PDEVICE_EXTENSION DeviceExt,
 
     // Find the maximum index root size given what the file record can hold
     // First, find the max index size assuming index root is the last attribute
-    ULONG NewMaxIndexRootSize =
+    NewMaxIndexRootSize =
        DeviceExt->NtfsInfo.BytesPerFileRecord                // Start with the size of a file record
         - IndexRootOffset                                    // Subtract the length of everything that comes before index root
         - IndexRootContext->pRecord->Resident.ValueOffset    // Subtract the length of the attribute header for index root
@@ -2361,7 +2363,7 @@ NtfsAddFilenameToDirectory(PDEVICE_EXTENSION DeviceExt,
 
     // The index allocation and index bitmap may have grown, leaving less room for the index root,
     // so now we need to double-check that index root isn't too large 
-    ULONG NodeSize = GetSizeOfIndexEntries(NewTree->RootNode);
+    NodeSize = GetSizeOfIndexEntries(NewTree->RootNode);
     if (NodeSize > NewMaxIndexRootSize)
     {
         DPRINT1("Demoting index root.\nNodeSize: 0x%lx\nNewMaxIndexRootSize: 0x%lx\n", NodeSize, NewMaxIndexRootSize);
@@ -2624,7 +2626,7 @@ CompareFileName(PUNICODE_STRING FileName,
 * @param Vcb
 * Pointer to an NTFS_VCB for the volume whose Mft mirror is being updated.
 *
-* @returninja livecd
+* @return
 
 * STATUS_SUCCESS on success.
 * STATUS_INSUFFICIENT_RESOURCES if an allocation failed.