Re: vfs-scale, d_revalidate from nfsd

[Al Viro <viro@ZenIV.linux.org.uk>]

On Fri, Jan 14, 2011 at 02:29:11PM +1100, Nick Piggin wrote:
> > ? ? ? ?if (nd->flags & LOOKUP_RCU)
> > ? ? ? ? ? ? ? ?return -ECHILD;
> > ? ? ? ?return -EPERM;
> > }
> > when the sole intent of that sucker is to have dentry of /.xattr (pinned
> > in dcache and hashed all along) rejected on lookups from root? ?IOW, WTF
> > bother with -ECHILD here at all?
> 
> That's true. I guess I always have a weakness for doing "just one
> little easy optimisation/simplification" folded into patch that is supposed
> to be more mechanical changes :) I did have exactly that in the patch
> initially, but I decided it's better just to do everything with -ECHILD first.
> 
> That also gives the -ECHILD paths a bit more workout before
> fs conversions are done, too.

Not unless your test loads include trying to access pathnames like
/.xattr/whatever on reiserfs and watching those attempts fail...