Re: [RFC PATCH 3/6] NFSD: Avoid using rqstp->rq_vers in nfsd_set_fh_dentry()

[Mike Snitzer <snitzer@kernel.org>]

On Wed, Aug 28, 2024 at 09:45:31AM -0400, Chuck Lever wrote:
> On Wed, Aug 28, 2024 at 03:02:42PM +1000, NeilBrown wrote:
> > On Wed, 28 Aug 2024, cel@kernel.org wrote:
> > > From: Chuck Lever <chuck.lever@oracle.com>
> > > 
> > > Currently, fh_verify() makes some daring assumptions about which
> > > version of file handle the caller wants, based on the things it can
> > > find in the passed-in rqstp. The about-to-be-introduced LOCALIO use
> > > case sometimes has no svc_rqst context, so this logic won't work in
> > > that case.
> > > 
> > > Instead, examine the passed-in file handle. It's .max_size field
> > > should carry information to allow nfsd_set_fh_dentry() to initialize
> > > the file handle appropriately.
> > > 
> > > lockd appears to be the only kernel consumer that does not set the
> > > file handle .max_size when during initialization.
> > > 
> > > write_filehandle() is the other question mark, as it looks possible
> > > to specify a maxsize between NFS_FHSIZE and NFS3_FHSIZE here.
> > 
> > The file handle used by lockd and the one created by write_filehandle
> > never need any of the version-specific fields.
> > Those fields affect things like write requests and getattr requests and
> > pre/post attributes.
> 
> Then we could simply drop the "case 0:" arm and maybe the lockd hunk
> from this patch.

OK, will do.