Re: [PATCH v13 07/19] SUNRPC: add rpcauth_map_clnt_to_svc_cred_local

[Mike Snitzer <snitzer@kernel.org>]

On Sun, Aug 25, 2024 at 11:17:00AM -0400, Chuck Lever wrote:
> On Fri, Aug 23, 2024 at 02:14:05PM -0400, Mike Snitzer wrote:
> > From: Weston Andros Adamson <dros@primarydata.com>
> > 
> > Add new funtion rpcauth_map_clnt_to_svc_cred_local which maps a
> > generic cred to a svc_cred suitable for use in nfsd.
> > 
> > This is needed by the localio code to map nfs client creds to nfs
> > server credentials.
> > 
> > Following from net/sunrpc/auth_unix.c:unx_marshal() it is clear that
> > ->fsuid and ->fsgid must be used (rather than ->uid and ->gid).  In
> > addition, these uid and gid must be translated with from_kuid_munged()
> > so local client uses correct uid and gid when acting as local server.
> > 
> > Suggested-by: NeilBrown <neilb@suse.de> # to approximate unx_marshal()
> > Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
> > Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> > Co-developed-by: Mike Snitzer <snitzer@kernel.org>
> > Signed-off-by: Mike Snitzer <snitzer@kernel.org>
> > ---
> >  include/linux/sunrpc/auth.h |  4 ++++
> >  net/sunrpc/auth.c           | 22 ++++++++++++++++++++++
> >  2 files changed, 26 insertions(+)
> > 
> > diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
> > index 61e58327b1aa..4cfb68f511db 100644
> > --- a/include/linux/sunrpc/auth.h
> > +++ b/include/linux/sunrpc/auth.h
> > @@ -11,6 +11,7 @@
> >  #define _LINUX_SUNRPC_AUTH_H
> >  
> >  #include <linux/sunrpc/sched.h>
> > +#include <linux/sunrpc/svcauth.h>
> >  #include <linux/sunrpc/msg_prot.h>
> >  #include <linux/sunrpc/xdr.h>
> >  
> > @@ -184,6 +185,9 @@ int			rpcauth_uptodatecred(struct rpc_task *);
> >  int			rpcauth_init_credcache(struct rpc_auth *);
> >  void			rpcauth_destroy_credcache(struct rpc_auth *);
> >  void			rpcauth_clear_credcache(struct rpc_cred_cache *);
> > +void			rpcauth_map_clnt_to_svc_cred_local(struct rpc_clnt *clnt,
> > +							   const struct cred *,
> > +							   struct svc_cred *);
> >  char *			rpcauth_stringify_acceptor(struct rpc_cred *);
> >  
> >  static inline
> > diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
> > index 04534ea537c8..3b6d91b36589 100644
> > --- a/net/sunrpc/auth.c
> > +++ b/net/sunrpc/auth.c
> > @@ -17,6 +17,7 @@
> >  #include <linux/sunrpc/clnt.h>
> >  #include <linux/sunrpc/gss_api.h>
> >  #include <linux/spinlock.h>
> > +#include <linux/user_namespace.h>
> >  
> >  #include <trace/events/sunrpc.h>
> >  
> > @@ -308,6 +309,27 @@ rpcauth_init_credcache(struct rpc_auth *auth)
> >  }
> >  EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
> >  
> 
> rpcauth_map_clnt_to_svc_cred_local() needs a kdoc comment.
> 
> Since it is called only from fs/nfsd/localio.c -- should this API
>                                 ^^^^
> reside in net/sunrpc/svcauth.c instead of net/sunrpc/auth.c ?
> 

Yes, that makes sense.  I also renamed it to
svcauth_map_clnt_to_svc_cred_local

Thanks.