[PATCH] VFS: convert to using ceph_statx structures and functions, when available

[Jeremy Allison]

On Thu, Nov 17, 2016 at 10:39:25PM +0100, Ralph Böhme wrote:
> Hi
> 
> On Thu, Nov 17, 2016 at 01:13:57PM -0500, Jeff Layton wrote:
> > Add a configure test for the ceph_statx function, and use that to
> > determine whether to compile in new functions that use it and its
> > variants, or whether to use a the older code that fetches birthtimes
> > from an xattr.
> > 
> > For cephwrap_lstat, we can use ceph_statx with the AT_SYMLINK_NOFOLLOW
> > flag to get the right lookup semantics.
> > 
> > For setting the times via cephwrap_ntimes, We can just use ceph_setattrx
> > and pass them all in at the same time.
> 
> fwiw, this is something that I've been working on lately: add a full
> fledged VFS_STATX call to out VFS.
> 
> The primary reason and benefit is performance, as it helps avoiding
> reduntant stuff in the VFS frontend->backend interaction.
> 
> It'll also allow fetching *all* relevant file metadata attributes in a
> VFS_STATX call, like btime or windows attributes, so it will be a nice
> cleanup as well.
> 
> This is not ready and still work in progress, but seeing Jeff's work
> on statx patches for ceph I thought I wanted to show what I have right
> now.

Cool ! Thanks for the snapshot Ralph - I look forward to reviewing
fully once you've fully baked it :-).

Cheers,

Jeremy.