Re: Squashfs without ./..

[Jan Harkes <jaharkes@cs.cmu.edu>]

On Fri, Mar 25, 2005 at 02:59:14PM +0100, Jesper Juhl wrote:
> On Thu, 24 Mar 2005, H. Peter Anvin wrote:
> > Note that Linux always accepts . and .. so it's just a matter of making them
> > appear in readdir.
> > 
> I'm working on that, but it's a learning experience for me, so it's going 
> a bit slow - but I'll get there.

Check the top of coda_venus_readdir in fs/coda/dir.c.

Coda's directories internally don't have the '.' and '..' as the first
two entries. In general it works just fine, I think there was one
application where it was causing a problem so now we use 'f_pos == 0'
and 'f_pos == 1' to spit out those entries based on dcache data.
f_pos >= 2 goes through the normal directory, but we skip the
out-of-order '.' and '..' entries.

Btw. the '.' and '..' entries are used by applications that are linked
against libc5 for the getpwd() implementation. I guess it was the only
way to get path information before the introduction of the dcache.

Oh, and the find -noleaf thing, a workaround for filesystems that don't
count subdirectories is to set the directory linkcount to 1 instead of
2 + number of subdirs. The find optimization then subtracts 2, and as a
result thinks there are (unsigned)-1 aka. UINT_MAX subdirectories and
find will end up calling stat() on every directory entry.

Jan