NFSv4: Add helpers for basic copying of stateids

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index c7249e2..87f7544 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -105,7 +105,7 @@
 			continue;
 		if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
 			continue;
-		if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
+		if (!nfs4_stateid_match(&state->stateid, stateid))
 			continue;
 		get_nfs_open_context(ctx);
 		spin_unlock(&inode->i_lock);
@@ -139,8 +139,7 @@
 	if (delegation != NULL) {
 		spin_lock(&delegation->lock);
 		if (delegation->inode != NULL) {
-			memcpy(delegation->stateid.data, res->delegation.data,
-			       sizeof(delegation->stateid.data));
+			nfs4_stateid_copy(&delegation->stateid, &res->delegation);
 			delegation->type = res->delegation_type;
 			delegation->maxsize = res->maxsize;
 			oldcred = delegation->cred;
@@ -236,8 +235,7 @@
 	delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
 	if (delegation == NULL)
 		return -ENOMEM;
-	memcpy(delegation->stateid.data, res->delegation.data,
-			sizeof(delegation->stateid.data));
+	nfs4_stateid_copy(&delegation->stateid, &res->delegation);
 	delegation->type = res->delegation_type;
 	delegation->maxsize = res->maxsize;
 	delegation->change_attr = inode->i_version;
@@ -250,8 +248,8 @@
 	old_delegation = rcu_dereference_protected(nfsi->delegation,
 					lockdep_is_held(&clp->cl_lock));
 	if (old_delegation != NULL) {
-		if (memcmp(&delegation->stateid, &old_delegation->stateid,
-					sizeof(old_delegation->stateid)) == 0 &&
+		if (nfs4_stateid_match(&delegation->stateid,
+					&old_delegation->stateid) &&
 				delegation->type == old_delegation->type) {
 			goto out;
 		}
@@ -708,7 +706,7 @@
 	rcu_read_lock();
 	delegation = rcu_dereference(nfsi->delegation);
 	if (delegation != NULL) {
-		memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
+		nfs4_stateid_copy(dst, &delegation->stateid);
 		ret = 1;
 	}
 	rcu_read_unlock();