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>

3 files changed, 12 insertions, 8 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index cf23eed01b1c..ac8f824ec34f 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -39,15 +39,15 @@ static const struct rpc_authops __rcu *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
 static LIST_HEAD(cred_unused);
 static unsigned long number_cred_unused;
 
-static struct rpc_cred machine_cred = {
-	.cr_count = REFCOUNT_INIT(1),
+static struct cred machine_cred = {
+	.usage = ATOMIC_INIT(1),
 };
 
 /*
  * Return the machine_cred pointer to be used whenever
  * the a generic machine credential is needed.
  */
-struct rpc_cred *rpc_machine_cred(void)
+const struct cred *rpc_machine_cred(void)
 {
 	return &machine_cred;
 }
@@ -720,11 +720,15 @@ rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
 }
 
 static int
-rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
+rpcauth_bindcred(struct rpc_task *task, const struct cred *cred, int flags)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
 	struct rpc_cred *new = NULL;
 	int lookupflags = 0;
+	struct rpc_auth *auth = task->tk_client->cl_auth;
+	struct auth_cred acred = {
+		.cred = cred,
+	};
 
 	if (flags & RPC_TASK_ASYNC)
 		lookupflags |= RPCAUTH_LOOKUP_NEW;
@@ -733,7 +737,7 @@ rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 		new = task->tk_op_cred->cr_ops->crbind(task, task->tk_op_cred,
 						       lookupflags);
 	else if (cred != NULL && cred != &machine_cred)
-		new = cred->cr_ops->crbind(task, cred, lookupflags);
+		new = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
 	else if (cred == &machine_cred)
 		new = rpcauth_bind_machine_cred(task, lookupflags);
 
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 4cb697cfb377..cad26f816d20 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1030,7 +1030,7 @@ rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 		task->tk_msg.rpc_argp = msg->rpc_argp;
 		task->tk_msg.rpc_resp = msg->rpc_resp;
 		if (msg->rpc_cred != NULL)
-			task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
+			task->tk_msg.rpc_cred = get_cred(msg->rpc_cred);
 	}
 }
 
@@ -2542,7 +2542,7 @@ struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
 		.rpc_op_cred = cred,
 		.callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
 		.callback_data = data,
-		.flags = flags,
+		.flags = flags | RPC_TASK_NULLCREDS,
 	};
 
 	return rpc_run_task(&task_setup_data);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index c9f65037a6ad..adc3c40cc733 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -1074,7 +1074,7 @@ static void rpc_release_resources_task(struct rpc_task *task)
 {
 	xprt_release(task);
 	if (task->tk_msg.rpc_cred) {
-		put_rpccred(task->tk_msg.rpc_cred);
+		put_cred(task->tk_msg.rpc_cred);
 		task->tk_msg.rpc_cred = NULL;
 	}
 	rpc_task_release_client(task);