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>
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index a2e9e09..a3ad2d4 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -195,20 +195,15 @@ static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
 		.access		= entry->mask,
 	};
 	struct nfs3_accessres	res;
-	struct auth_cred acred = {
-		.cred		= entry->cred,
-	};
 	struct rpc_message msg = {
 		.rpc_proc	= &nfs3_procedures[NFS3PROC_ACCESS],
 		.rpc_argp	= &arg,
 		.rpc_resp	= &res,
-		.rpc_cred	= rpc_lookup_generic_cred(&acred, 0, GFP_NOFS),
+		.rpc_cred	= entry->cred,
 	};
 	int status = -ENOMEM;
 
 	dprintk("NFS call  access\n");
-	if (!msg.rpc_cred)
-		goto out;
 	res.fattr = nfs_alloc_fattr();
 	if (res.fattr == NULL)
 		goto out;
@@ -219,8 +214,6 @@ static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
 		nfs_access_set_mask(entry, res.access);
 	nfs_free_fattr(res.fattr);
 out:
-	if (msg.rpc_cred)
-		put_rpccred(msg.rpc_cred);
 	dprintk("NFS reply access: %d\n", status);
 	return status;
 }
@@ -631,15 +624,11 @@ nfs3_proc_readdir(struct dentry *dentry, const struct cred *cred,
 		.verf		= verf,
 		.plus		= plus
 	};
-	struct auth_cred acred = {
-		.cred		= cred,
-	};
 	struct rpc_message	msg = {
 		.rpc_proc	= &nfs3_procedures[NFS3PROC_READDIR],
 		.rpc_argp	= &arg,
 		.rpc_resp	= &res,
-		.rpc_cred	= rpc_lookup_generic_cred(&acred,
-							  0, GFP_NOFS),
+		.rpc_cred	= cred,
 	};
 	int status = -ENOMEM;
 
@@ -649,8 +638,6 @@ nfs3_proc_readdir(struct dentry *dentry, const struct cred *cred,
 	dprintk("NFS call  readdir%s %d\n",
 			plus? "plus" : "", (unsigned int) cookie);
 
-	if (!msg.rpc_cred)
-		return -ENOMEM;
 	res.dir_attr = nfs_alloc_fattr();
 	if (res.dir_attr == NULL)
 		goto out;
@@ -662,7 +649,6 @@ nfs3_proc_readdir(struct dentry *dentry, const struct cred *cred,
 
 	nfs_free_fattr(res.dir_attr);
 out:
-	put_rpccred(msg.rpc_cred);
 	dprintk("NFS reply readdir%s: %d\n",
 			plus? "plus" : "", status);
 	return status;