Re: autofs v4: speak now .... documents

[H. Peter Anvin]

> H. Peter Anvin writes:
> > Will do.  For what it's worth, I discussed a few options for
> > supporting direct mounts (based on Richard's suggestion) with Linus
> > today, and I might actually be able to get a VFS change into 2.3
> > that would let us support direct mounts; we're evaluating a few
> > methods (including one option of supporting sandwich mounts that
> > hadn't been considered before.)  Please don't get your hopes too far
> > up, but there is at least a possibility that direct mounts might be
> > supportable after all.
> 
> Could you explain what you have in mind for these sandwich mounts? How
> would they work?
> 

Basically, I argued with Linus for letting me add another pointer to
the dentry.  Instead of d_mounts and d_covers we would have a d_top,
d_bottom and d_down pointers.  This means you still don't need any
tests: d_top will always take you to the topmost dentry (like the
current d_mounts) and d_bottom will take you to the bottommost entry
(like the current d_covers).  The d_down pointers would form a linked
list of entries to be popped off by umount.

        -hpa