Re: [Lsf-pc] [1/8] readdir-plus system call - LSF/MM follow up

["J. Bruce Fields" <bfields@redhat.com>]

On Tue, Jun 04, 2013 at 08:38:48AM -0700, Christoph Hellwig wrote:
> On Wed, May 29, 2013 at 10:04:56AM -0400, J. Bruce Fields wrote:
> > An odd exception: in the presence of "posix" acls, "ls -l" requests an
> > acl for every entry, so it can decide whether or not to add a "+" after
> > the mode (which indicates the presence of a non-trivial acl.) Judging
> > from http://www.bestbits.at/richacl/example.html, the same is intended
> > (but not yet implemented) for richacls.
> > 
> > Maybe if that case were common, there'd be some advantage to ls being
> > able to do a readdir plus to the nfs client that the nfs client could
> > translate into a single readdir to the server?
> > 
> > But I hope it doesn't come to that.
> 
> Having a xstat flag that a filesystem can set meaning there is no
> additional security information would be way more efficient for the
> common case.

I think that might make sense.

(Though I can't claim any evidence of an actual problem here.  Just that
if people are counting the stat's on "ls -l" then may find out they run
into those extra getxattrs too.)

--b.