NFS: Move cl_state_owners and related fields to the nfs_server struct

NFSv4 migration needs to reassociate state owners from the source to
the destination nfs_server data structures.  To make that easier, move
the cl_state_owners field to the nfs_server struct.  cl_openowner_id
and cl_lockowner_id accompany this move, as they are used in
conjunction with cl_state_owners.

The cl_lock field in the parent nfs_client continues to protect all
three of these fields.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4_fs.h

@@ -110,7 +110,7 @@ struct nfs_unique_id {
 struct nfs4_state_owner {
 	struct nfs_unique_id so_owner_id;
 	struct nfs_server    *so_server;
-	struct rb_node	     so_client_node;
+	struct rb_node	     so_server_node;
 
 	struct rpc_cred	     *so_cred;	 /* Associated cred */
 

include/linux/nfs_fs_sb.h

@@ -47,11 +47,7 @@ struct nfs_client {
 	u64			cl_clientid;	/* constant */
 	unsigned long		cl_state;
 
-	struct rb_root		cl_openowner_id;
-	struct rb_root		cl_lockowner_id;
-
 	struct list_head	cl_delegations;
-	struct rb_root		cl_state_owners;
 	spinlock_t		cl_lock;
 
 	unsigned long		cl_lease_time;
@@ -150,6 +146,11 @@ struct nfs_server {
 						   filesystem */
 	struct pnfs_layoutdriver_type  *pnfs_curr_ld; /* Active layout driver */
 	struct rpc_wait_queue	roc_rpcwaitq;
+
+	/* the following fields are protected by nfs_client->cl_lock */
+	struct rb_root		state_owners;
+	struct rb_root		openowner_id;
+	struct rb_root		lockowner_id;
 #endif
 	void (*destroy)(struct nfs_server *);