diff --git a/Cache/BlockCache.h b/Cache/BlockCache.h
index f740c32..d613cf0 100644
--- a/Cache/BlockCache.h
+++ b/Cache/BlockCache.h
@@ -5,13 +5,12 @@
 #include <vector>
 
 class MappedFile;
-class Device::BlockDevice;
 
 namespace Device {
 
+class BlockDevice;
 
-
-enum {
+enum BlockReleaseFlags {
     kBlockDirty = 1,
     kBlockCommitNow = 2,
     kBlockReuse = 3
@@ -38,72 +37,20 @@ public:
     virtual void markDirty(unsigned block) = 0;
     
     void release(unsigned block) { release(block, 0); }
-    void release(unsigned block, bool dirty)  { release(block, dirty ? kBlockDirty : 0); }
+    void release(unsigned block, bool dirty) 
+        { release(block, dirty ? kBlockDirty : 0); }
 
 protected:
     BlockCache(BlockDevice *device);
 
     BlockDevice *_device;
-private
+    
+private:
     unsigned _blocks;
     bool _readOnly;
 };
 
 
-class ConcreteBlockCache : public BlockCache {
-public:
-    ConcreteBlockCache(BlockDevice *device, unsigned size = 16);
-    virtual ~ConcreteBlockCache();
-    
-    virtual void sync();
-    virtual void write(unsigned block, const void *vp) = 0;
-
-
-    virtual void *acquire(unsigned block);
-    virtual void release(unsigned block, int flags);
-    virtual void markDirty(unsigned block);
-
-
-private:
-    struct Entry {
-        unsigned block;
-        unsigned count;
-        bool dirty;
-        
-        struct Entry *next;
-        struct Entry *prev;
-        struct Entry *nextHash;
-        
-        uint8_t buffer[512];
-    
-    };
-
-    enum { HashTableSize = 23 };
-    
-    std::vector<Entry *>_buffers;
-    
-    Entry *_hashTable[HashTableSize];
-    
-    Entry *_first;
-    Entry *_last;
-
-
-    unsigned hashFunction(unsigned block);
-    
-    Entry *findEntry(unsigned block);
-    void removeEntry(unsigned block);
-    void addEntry(Entry *);
-    
-    Entry *newEntry(unsigned block);
-    
-    void pushEntry(Entry *);
-    
-    void setLast(Entry *);
-    
-    incrementCount(Entry *);
-    decrementCount(Entry *);
-};
-
 } // namespace
 
 #endif
diff --git a/Cache/MappedBlockCache.cpp b/Cache/MappedBlockCache.cpp
index 103f846..95df640 100644
--- a/Cache/MappedBlockCache.cpp
+++ b/Cache/MappedBlockCache.cpp
@@ -7,6 +7,8 @@
 #include <unistd.h>
 
 #include <Cache/MappedBlockCache.h>
+#include <Device/BlockDevice.h>
+
 #include <ProFUSE/Exception.h>
 
 
@@ -17,7 +19,7 @@ using ProFUSE::Exception;
 using ProFUSE::POSIXException;
 
 
-MappedBlockCache::MappedBlockCache(Device *device, void *data) :
+MappedBlockCache::MappedBlockCache(BlockDevice *device, void *data) :
     BlockCache(device)
 {
     _data = (uint8_t *)data;
@@ -42,7 +44,7 @@ void *MappedBlockCache::acquire(unsigned block)
     return _data + block * 512;
 }
 
-void MappedBlockCache::unload(unsigned block, int flags)
+void MappedBlockCache::release(unsigned block, int flags)
 {
 #undef __METHOD__
 #define __METHOD__ "MappedBlockCache::unload"
@@ -50,7 +52,7 @@ void MappedBlockCache::unload(unsigned block, int flags)
     // kBlockCommitNow implies kBlockDirty. 
     if (flags & kBlockCommitNow)
     {
-        sync(block)
+        sync(block);
         return;
     }
 
@@ -75,10 +77,14 @@ void MappedBlockCache::sync(unsigned block)
 #define __METHOD__ "MappedBlockCache::sync"
 
 
-    int pageSize = ::getpagesize();
+    int pagesize = ::getpagesize();
         
-    void *start = (_data + block * 512) % pagesize;
-    void *end = (_data + 512 + block * 512) % pagesize;
+    void *start = _data + block * 512;
+    void *end = _data + 512 + block * 512;
+
+
+    start = (void *)((ptrdiff_t)start / pagesize * pagesize);
+    end = (void *)((ptrdiff_t)end / pagesize * pagesize);
 
     if (::msync(start, pagesize, MS_SYNC) != 0)
         throw POSIXException(__METHOD__ ": msync", errno);
diff --git a/Cache/MappedBlockCache.h b/Cache/MappedBlockCache.h
index c10a362..fac9504 100644
--- a/Cache/MappedBlockCache.h
+++ b/Cache/MappedBlockCache.h
@@ -20,7 +20,7 @@ class MappedBlockCache : public BlockCache {
     virtual void markDirty(unsigned block);
 
     private:
-        void sync(block);
+        void sync(unsigned block);
         
         uint8_t *_data;
         bool _dirty;
@@ -29,4 +29,5 @@ class MappedBlockCache : public BlockCache {
 
 } // namespace
 
+#endif