SUNRPC: Add a helper rpcauth_lookup_generic_cred()

The NFSv4 protocol allows clients to negotiate security protocols on the
fly in the case where an administrator on the server changes the export
settings and/or in the case where we may have a filesystem migration event.

Instead of having the NFS client code cache credentials that are tied to a
particular AUTH method it is therefore preferable to have a generic credential
that can be converted into whatever AUTH is in use by the RPC client when
the read/write/sillyrename/... is put on the wire.

We do this by means of the new "generic" credential, which basically just
caches the minimal information that is needed to look up an RPCSEC_GSS,
AUTH_SYS, or AUTH_NULL credential.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 6cea7479c5b4..d583654a0b39 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1966,7 +1966,7 @@ force_lookup:
         if (!NFS_PROTO(inode)->access)
                 goto out_notsup;
 
-        cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
+        cred = rpc_lookup_cred();
         if (!IS_ERR(cred)) {
                 res = nfs_do_access(inode, cred, mask);
                 put_rpccred(cred);