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

["Matthias Urlichs" <smurf@noris.de>]

Hi,

Oleg Drokin:
> > When I tried this, reiserfsck with -S scanned the whole disk, as expected.
> > Reiserfsck without -S said it would scan roughly half of my disk. That led
> 
> Yes. It scans all the blocks that are marked as "used" in bitmap.
> 
That's not what I meant when I proposed this new option. The method 
which I proposed would walk the existing tree, both "downwards" and
"sideways", to find all reachable blocks with nodes, and then do the
existing rebuild-tree algorithm on the result.

> > me to conclude that whatever it does, it doesn't just use the blocks which
> > are actually used for the tree at the moment.
> 
> How can it know? It must find all the lost blocks too.
> 
... and how can it know that the bitmap represents reality?

Blocks have three pointers which point to them (left neighbour, right
neighbour, and parent).  (That's my understanding of the way people
usually lay out their B-trees, anyway; apologies if yours is radically
different.) I'd like to assume that blocks don't easily get lost when
there are so many ways to find them. Three pointers look safer than a
single bit, anyway.

This method would be a nice compromise between not fixing a problem,
depending on suspect information, and/or reconnecting every file which
I've deleted during the last year.

-- 
Matthias Urlichs     |     noris network AG     |     http://smurf.noris.de/