NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

2 files changed, 6 insertions, 12 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 1dcee1fd32d9..c74e4538d0eb 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -844,18 +844,15 @@ static int max_cb_time(struct net *net)
 	return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
 }
 
-static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
+static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
 {
 	if (clp->cl_minorversion == 0) {
 		client->cl_principal = clp->cl_cred.cr_targ_princ ?
 			clp->cl_cred.cr_targ_princ : "nfs";
 
-		return get_rpccred(rpc_machine_cred());
+		return get_cred(rpc_machine_cred());
 	} 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)
@@ -863,10 +860,7 @@ static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc
 
 		kcred->uid = ses->se_cb_sec.uid;
 		kcred->gid = ses->se_cb_sec.gid;
-		acred.cred = kcred;
-		ret = auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
-		put_cred(kcred);
-		return ret;
+		return kcred;
 	}
 }
 
@@ -889,7 +883,7 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
 		.flags		= (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
 	};
 	struct rpc_clnt *client;
-	struct rpc_cred *cred;
+	const struct cred *cred;
 
 	if (clp->cl_minorversion == 0) {
 		if (!clp->cl_cred.cr_principal &&
@@ -1219,7 +1213,7 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
 	if (clp->cl_cb_client) {
 		rpc_shutdown_client(clp->cl_cb_client);
 		clp->cl_cb_client = NULL;
-		put_rpccred(clp->cl_cb_cred);
+		put_cred(clp->cl_cb_cred);
 		clp->cl_cb_cred = NULL;
 	}
 	if (clp->cl_cb_conn.cb_xprt) {
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 6aacb325b6a0..396c76755b03 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -327,7 +327,7 @@ struct nfs4_client {
 #define NFSD4_CLIENT_CB_FLAG_MASK	(1 << NFSD4_CLIENT_CB_UPDATE | \
 					 1 << NFSD4_CLIENT_CB_KILL)
 	unsigned long		cl_flags;
-	struct rpc_cred		*cl_cb_cred;
+	const struct cred	*cl_cb_cred;
 	struct rpc_clnt		*cl_cb_client;
 	u32			cl_cb_ident;
 #define NFSD4_CB_UP		0