Re: shadowfs

[Kalle Olavi Niemitalo <tosi@stekt.oulu.fi>]

Tomasz Wegrzanowski <maniek@beer.com> writes:

> They can be faked by shadowfs, with content scaned on demand as of other dirs
> and maybe cached until notified of directory change
>     (on notify not to rescan, only to invalidate cache)

So, for each open directory, the shadowfs would remember the
steps taken to get there?  That could work.

If the user:

1. makes a directory ~/1 and a shadowfs ~/shadow which uses it
2. makes a directory ~/1/foo
3. changes directory to ~/shadowfs/foo
4. renames ~/1/foo to ~/1/bar
5. ls

then the shadowfs tries to find ~/1/foo, and because it doesn't
exist, the user gets ENOENT.  This sounds reasonable.

If the user then makes another directory ~/1/foo, the current
directory starts referring to that instead, and ls works again.

ENOENT on missing directories isn't the only possible way: the
shadowfs could instead give the user an empty (except . and ..)
directory so that he can at least "cd ..".  Would that be better?