SUNRPC: add 'struct cred *' to auth_cred and rpc_cred

The SUNRPC credential framework was put together before
Linux has 'struct cred'.  Now that we have it, it makes sense to
use it.
This first step just includes a suitable 'struct cred *' pointer
in every 'struct auth_cred' and almost every 'struct rpc_cred'.

The rpc_cred used for auth_null has a NULL 'struct cred *' as nothing
else really makes sense.

For rpc_cred, the pointer is reference counted.
For auth_cred it isn't.  struct auth_cred are either allocated on
the stack, in which case the thread owns a reference to the auth,
or are part of 'struct generic_cred' in which case gc_base owns the
reference, and "acred" shares it.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 25987bcdf96f..7c7e3510599d 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -858,10 +858,21 @@ static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc
 	} else {
 		struct rpc_auth *auth = client->cl_auth;
 		struct auth_cred acred = {};
+		struct cred *kcred;
+		struct rpc_cred *ret;
+
+		kcred = prepare_kernel_cred(NULL);
+		if (!kcred)
+			return NULL;
 
 		acred.uid = ses->se_cb_sec.uid;
 		acred.gid = ses->se_cb_sec.gid;
-		return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
+		kcred->uid = acred.uid;
+		kcred->gid = acred.gid;
+		acred.cred = kcred;
+		ret = auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
+		put_cred(kcred);
+		return ret;
 	}
 }