On Sat Feb 24 2007 at 21:24:44 +0200, Alan Barrett wrote:
> > > $ /usr/pkg/bin/perl5.8.8 -e 'system "ls", "-l", "/proc/$$/exe"'
> > > lr-xr-xr-x  1 root  wheel  1 Feb 24 11:53 /proc/26280/exe -> /
> > 
> > This is probably because "exe" has never been "really" supported.
> > Rather, it's fetched from the name lookup cache.  If the entry for a
> > particular vnode gets flushed (or it's never entered - this is file
> > system specific behaviour), the exe-link is out of luck.
> 
> What confuses me is that /proc/${pid}/cwd does not suffer from the
> problem, although the code paths in procfs_vnops.c for PFScwd and PFSexe
> are so similar.  Anyway, I raised a PR (number 35830).

That's because cwd can do real getcwd if the entry is not found in the
cache - directories always have a unique parent.  Other types of file
system nodes, however, lack this luxury (think hardlinks).

As a hack to fix a hack, maybe we can add layerfs support the name cache?
What do people think?

-- 
Antti Kantee <pooka@iki.fi>                     Of course he runs NetBSD
http://www.iki.fi/pooka/                          http://www.NetBSD.org/
    "la qualité la plus indispensable du cuisinier est l'exactitude"