Make LispM code FREE (fwd)

Chris Bitmead chrisb@Ans.Com.Au
Wed, 01 Apr 1998 07:52:26 +0000

> > The internals of the file system design are utterly utterly
> > different. Yes at user level they look the same, but that's not
> > what I'm talking about. I'm talking about the implementation
> > design.
> Not only do they look the same at user level, but directories are
> implemented as lists of (name, inum) pairs 

Sure, you can't change that without changing the look from the
user level. But even the structure of a directory on disk is
different. The original UNIX had fixed length 16 byte entries,
Linux has variable length entries in 512 byte blocks.

> which are ordinary files
> with a special attribute bit, metadata is stored in `inodes', inodes
> have pointers to data blocks, an indirect block, and some doubly
> indirect blocks, and a triply indirect block, etc.  The disk is
> statically partitioned into inodes and data blocks.

Yeah, that is all basicly still user level details. The keeping
track of free blocks is different, the arrangment of the inodes
on the disk is different. No code would be salvagable.

Chris Bitmead