Re: nfs-utils 1.1.2 + knfsd 2.6.27 (.5) breaks fsid= option

["J. Bruce Fields" <bfields@fieldses.org>]

On Sun, Nov 16, 2008 at 03:02:11PM -0500, bfields wrote:
> On Wed, Nov 12, 2008 at 08:48:47AM -0500, Steve Dickson wrote:
> > Frank van Maarseveen wrote:
> > > Tested on Debian lenny with nfs-kernel-server 1:1.1.2-6lenny1 and a
> > > 2.6.27.5 kernel. /etc/exports says:
> > > 
> > > 	/mp @general(rw,sync,no_root_squash,no_subtree_check,mp,fsid=2886795869)
> > > 
> > > After actually using it /proc/fs/nfsd/exports says:
> > > 
> > > 	/mp @general(rw,no_root_squash,sync,wdelay,no_subtree_check,fsid=-1408171427,uuid=db4387a6:bed949d0:8f5ef6a2:6a0c
> > > 
> > > (yes, 2886795869 == (ulong)-1408171427)
> > > However, file handles over the wire now seem to have fsid_type=6
> > > (FSID_UUID16) instead of 1 (FSID_NUM) due to this.
> > 
> > This is a known problem... The kernel checks UUIDs before FSIDS which cause
> > FSIDS to be ignored. There are two outstanding proposals to fix this problem.
> >    1) Move two lines in the kernel so FSIDs are checked before UUIDS
> >    2) Change mountd to only send down  the FSID or the UUID but
> >       not both as it does today.
> >  
> > Neither proposal has been accepted... yet...
> 
> I'd have a mild preference for the 2nd,

Maybe I should take that back--Neil, don't we need to pass down the uuid
to match the client-provided filehandle type in the case where they're
giving us uuid-style filehandles?  In that case we need to pass down
both so the kernel can choose the desired one.  So if we need to fix
this then that would make SteveD's patch the way to go.

--b.