NFS/SUNRPC: don't lookup machine credential until rpcauth_bindcred().
When NFS creates a machine credential, it is a "generic" credential,
not tied to any auth protocol, and is really just a container for
the princpal name.
This doesn't get linked to a genuine credential until rpcauth_bindcred()
is called.
The lookup always succeeds, so various places that test if the machine
credential is NULL, are pointless.
As a step towards getting rid of generic credentials, this patch gets
rid of generic machine credentials. The nfs_client and rpc_client
just hold a pointer to a constant principal name.
When a machine credential is wanted, a special static 'struct rpc_cred'
pointer is used. rpcauth_bindcred() recognizes this, finds the
principal from the client, and binds the correct credential.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index ad649a4..eab4149 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -338,7 +338,6 @@ static inline bool
_nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
struct rpc_clnt **clntp, struct rpc_message *msg)
{
- struct rpc_cred *newcred = NULL;
rpc_authflavor_t flavor;
if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
@@ -353,13 +352,7 @@ _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
return false;
}
if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
- spin_lock(&clp->cl_lock);
- if (clp->cl_machine_cred != NULL)
- /* don't call get_rpccred on the machine cred -
- * a reference will be held for life of clp */
- newcred = clp->cl_machine_cred;
- spin_unlock(&clp->cl_lock);
- msg->rpc_cred = newcred;
+ msg->rpc_cred = rpc_machine_cred();
flavor = clp->cl_rpcclient->cl_auth->au_flavor;
WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&