kernel: Make StorageCache have a reference to its parent BlockDevice

This will make it easier to implement sync later on.

kernel/src/fs/StorageCache.cpp

@@ -33,7 +33,7 @@ void StorageCache::clear()
     m_mutex.unlock();
 }
 
-StorageCache::StorageCache()
+StorageCache::StorageCache(BlockDevice* device) : m_device(device)
 {
     g_storage_caches.append(this);
 }

kernel/src/fs/StorageCache.h

@@ -4,12 +4,15 @@
 #include <luna/HashMap.h>
 #include <luna/LinkedList.h>
 
+class BlockDevice;
+
 class StorageCache : public LinkedListNode<StorageCache>
 {
   public:
     struct CacheEntry
     {
         Buffer buffer {};
+        bool dirty;
     };
 
     void lock()
@@ -28,10 +31,11 @@ class StorageCache : public LinkedListNode<StorageCache>
 
     static void clear_caches();
 
-    StorageCache();
+    StorageCache(BlockDevice* device);
     ~StorageCache();
 
   private:
     HashMap<u64, CacheEntry> m_cache_entries;
+    BlockDevice* m_device;
     Mutex m_mutex;
 };

kernel/src/fs/devices/BlockDevice.cpp

@@ -2,7 +2,8 @@
 #include "arch/MMU.h"
 #include <luna/Common.h>
 
-BlockDevice::BlockDevice(u64 block_size, u64 num_blocks) : m_cache(), m_block_size(block_size), m_num_blocks(num_blocks)
+BlockDevice::BlockDevice(u64 block_size, u64 num_blocks)
+    : m_cache(this), m_block_size(block_size), m_num_blocks(num_blocks)
 {
 }