Added Volume::IsValidInodeBlock().

* The method checks whether a block may be occupied by an inode, ie. is neither
  part of the bitmap nor of the log, and would also fit on the disk.
* Also made disk_super_block::IsValid() const.

src/add-ons/kernel/file_systems/bfs/Volume.cpp

@@ -1,8 +1,9 @@
 /*
- * Copyright 2001-2009, Axel Dörfler, [email protected].
+ * Copyright 2001-2012, Axel Dörfler, [email protected].
  * This file may be used under the terms of the MIT License.
  */
 
+
 //! super block, mounting, etc.
 
 
@@ -189,7 +190,7 @@ DeviceOpener::GetSize(off_t* _size, uint32* _blockSize)
 
 
 bool
-disk_super_block::IsValid()
+disk_super_block::IsValid() const
 {
 	if (Magic1() != (int32)SUPER_BLOCK_MAGIC1
 		|| Magic2() != (int32)SUPER_BLOCK_MAGIC2
@@ -296,12 +297,21 @@ Volume::~Volume()
 
 
 bool
-Volume::IsValidSuperBlock()
+Volume::IsValidSuperBlock() const
 {
 	return fSuperBlock.IsValid();
 }
 
 
+/*!	Checks whether the given block number may be the location of an inode block.
+*/
+bool
+Volume::IsValidInodeBlock(off_t block) const
+{
+	return block > fSuperBlock.LogEnd() && block < NumBlocks();
+}
+
+
 void
 Volume::Panic()
 {

src/add-ons/kernel/file_systems/bfs/Volume.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2010, Axel Dörfler, [email protected].
+ * Copyright 2001-2012, Axel Dörfler, [email protected].
  * This file may be used under the terms of the MIT License.
  */
 #ifndef VOLUME_H
@@ -40,7 +40,8 @@ public:
 
 			bool			IsInitializing() const { return fVolume == NULL; }
 
-			bool			IsValidSuperBlock();
+			bool			IsValidSuperBlock() const;
+			bool			IsValidInodeBlock(off_t block) const;
 			bool			IsReadOnly() const;
 			void			Panic();
 			mutex&			Lock();

src/add-ons/kernel/file_systems/bfs/bfs.h

@@ -99,7 +99,7 @@ struct disk_super_block {
 	off_t LogEnd() const { return BFS_ENDIAN_TO_HOST_INT64(log_end); }
 
 	// implemented in Volume.cpp:
-	bool IsValid();
+	bool IsValid() const;
 	void Initialize(const char *name, off_t numBlocks, uint32 blockSize);
 } _PACKED;