Re: semantics of TRYEMULROOT

[David Laight <david%l8s.co.uk@localhost>]

On Sun, Jan 02, 2011 at 09:52:31AM +0000, David Holland wrote:
> Has anyone ever sat down and clearly worked out the desired semantics
> for TRYEMULROOT? I've noted inconsistencies in the past, and because
> in a number of ways it's a special case of onionfs I'm somewhat
> concerned that there may be cases where the proper or desired behavior
> is unclear or ambiguous.

When I added TRYEMULROOT I did so in order to maintain the same actions
as the old code - which did all sorts of horrid checks before copying
a changed path out into the stackgap.
At that time I didn't want to be worried about which code paths should,
or should not, look in the emulated root - since many of the emulations
were probably broken.

You are probably the only one who has actually looked into this deeply!
It does seem likely that only ENOENT (and similar) should cause the
main fs to be checked.

        David

-- 
David Laight: david%l8s.co.uk@localhost