Re: pbuilder: cowdancer/cowbuilder status update

[Junichi Uekawa <dancer@netfort.gr.jp>]

Hi,

> > Another difference I noticed is that fl-cow takes a list of
> > directories to protect in FL_COW, and seems to copy files
> > unconditionally on 'open'.
> > 
> > cowdancer caches a list of i-nodes so that it won't try to break
> > hardlinks more than once. (cow-shell does this much work).
> 
> Nice. I'm not sure both tools need to be in debian. How mature is
> cowdancer - can it replace fl-cow at this point? (fl-cows primary use is
> to be told 'these paths may contain hardlinked files, please unhardlink
> any of them on write').

For an application like fl-cow/cowdancer to be used reliably these
things need to be considered:


1. How will it handle failure cases?

2. It's LD_PRELOAD from every application, is it thread-safe?

3. What happens if the filesystem has SELinux labels etc?

4. What happens if the user is running as root?

5. What happens if there is 0% free disk space available, will it
   erase the file or not touch it?


I think there are others, but anyway, I'm trying to address these
issues in cowdancer. 

I'll look into fl-cow and see what I can pick up from there.


regards,
	junichi
-- 
dancer@{debian.org,netfort.gr.jp}   Debian Project