Re: fsck mode halfway between --fix-fixable and --rebuild-tree ?

[Hans Reiser <reiser@namesys.com>]

Matthias Urlichs wrote:

>Hi,
>
>Hans Reiser:
>  
>
>>>Actually, B-link trees (B-trees with sibling pointers) don't require any
>>>additional io for sibling pointers maintenance. Just draw a picture of
>>>what is going on during insertion of new node or node deletion and you
>>>will see. 
>>>
>>>      
>>>
>>They have constraints we do not desire.  Also, I think they link in only 
>>one direction.  Am I right?
>>
>>    
>>
>Whether you use just a forward-pointing link or also a back-pointing link
>(or nothing at all) is up to you. Personally I like sibling and parent
>links because it is very easy to walk the tree iteratively (just follow
>the "next" or "prev" pointer when you're done with a node). Trees which
>only use downward-pointing links need to be walked recursively.
>
>On the other hand, you're a multitasking file system, therefore you need
>locking, therefore side pointers won't be of much use to you for anything
>(except additional redundancy for error recovery).
>
>  
>
Oh, it is not nearly so simple an argument.... Please read the b-link 
literature.  It is at least interesting, even if we did something else.