Duplication of dirent names in JFFS2 summary

[Artem B. Bityutskiy]

David Woodhouse wrote:
> It's a little unfortunate that we have to actually keep a second copy of
> the name in the summary. Is there any way we could avoid it?
> 
> One possibility might be to refrain from storing the name in the dirent
> node itself -- store it _only_ in the summary. This could happen only
> during garbage collection -- when we GC a dirent node, we could write it
> out _without_ its name. In fact, we could possibly refrain from writing
> the GC'd dirent to the log at all -- put it _only_ in the summary.
> 
> That does break backwards compatibility though, which isn't ideal.
And it's just bad:

o it's hacky;
o it'll introduce many if()s in code and make it even more copmplecated;
o finally, it'll interfer robustness: if the summary node get's 
corrupted, we may loose a lot - not just one node;

I believe that this approach has to be vetoed.

> Another possibility might be to omit the full name from the summary, but
> to store only the hash (or name_crc) instead. We hardly ever actually
> need the full name -- it's only used if there's a hash collision, in
> jffs2_add_fd_to_list().
Good idea.

-- 
Best Regards,
Artem B. Bityutskiy,
St.-Petersburg, Russia.