NFSv4.1: Ensure that we free the lock stateid on the server

This ensures that the server doesn't need to keep huge numbers of
lock stateids waiting around for the final CLOSE.
See section 8.2.4 in RFC5661.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4_fs.h

@@ -47,6 +47,8 @@ struct nfs4_minor_version_ops {
 			const nfs4_stateid *);
 	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
 			struct nfs_fsinfo *);
+	int	(*free_lock_state)(struct nfs_server *,
+			struct nfs4_lock_state *);
 	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
 	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
 	const struct nfs4_state_maintenance_ops *state_renewal_ops;
@@ -234,7 +236,6 @@ extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struc
 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, struct qstr *,
 			    struct nfs_fh *, struct nfs_fattr *);
 extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
-extern int nfs4_release_lockowner(struct nfs4_lock_state *);
 extern const struct xattr_handler *nfs4_xattr_handlers[];
 extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
 		const struct nfs_open_context *ctx,

fs/nfs/nfs4proc.c

@@ -5238,9 +5238,8 @@ static const struct rpc_call_ops nfs4_release_lockowner_ops = {
 	.rpc_release = nfs4_release_lockowner_release,
 };
 
-int nfs4_release_lockowner(struct nfs4_lock_state *lsp)
+static int nfs4_release_lockowner(struct nfs_server *server, struct nfs4_lock_state *lsp)
 {
-	struct nfs_server *server = lsp->ls_state->owner->so_server;
 	struct nfs_release_lockowner_data *data;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RELEASE_LOCKOWNER],
@@ -6879,6 +6878,18 @@ static int nfs41_free_stateid(struct nfs_server *server, nfs4_stateid *stateid)
 	return ret;
 }
 
+static int nfs41_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
+{
+	struct rpc_task *task;
+
+	task = _nfs41_free_stateid(server, &lsp->ls_stateid, false);
+	nfs4_free_lock_state(server, lsp);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+
 static bool nfs41_match_stateid(const nfs4_stateid *s1,
 		const nfs4_stateid *s2)
 {
@@ -6968,6 +6979,7 @@ static const struct nfs4_minor_version_ops nfs_v4_0_minor_ops = {
 	.call_sync = _nfs4_call_sync,
 	.match_stateid = nfs4_match_stateid,
 	.find_root_sec = nfs4_find_root_sec,
+	.free_lock_state = nfs4_release_lockowner,
 	.reboot_recovery_ops = &nfs40_reboot_recovery_ops,
 	.nograce_recovery_ops = &nfs40_nograce_recovery_ops,
 	.state_renewal_ops = &nfs40_state_renewal_ops,
@@ -6985,6 +6997,7 @@ static const struct nfs4_minor_version_ops nfs_v4_1_minor_ops = {
 	.call_sync = nfs4_call_sync_sequence,
 	.match_stateid = nfs41_match_stateid,
 	.find_root_sec = nfs41_find_root_sec,
+	.free_lock_state = nfs41_free_lock_state,
 	.reboot_recovery_ops = &nfs41_reboot_recovery_ops,
 	.nograce_recovery_ops = &nfs41_nograce_recovery_ops,
 	.state_renewal_ops = &nfs41_state_renewal_ops,

fs/nfs/nfs4state.c

@@ -921,6 +921,7 @@ static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_
  */
 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 {
+	struct nfs_server *server;
 	struct nfs4_state *state;
 
 	if (lsp == NULL)
@@ -932,11 +933,13 @@ void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 	if (list_empty(&state->lock_states))
 		clear_bit(LK_STATE_IN_USE, &state->flags);
 	spin_unlock(&state->state_lock);
+	server = state->owner->so_server;
 	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
-		if (nfs4_release_lockowner(lsp) == 0)
-			return;
-	}
-	nfs4_free_lock_state(lsp->ls_state->owner->so_server, lsp);
+		struct nfs_client *clp = server->nfs_client;
+
+		clp->cl_mvops->free_lock_state(server, lsp);
+	} else
+		nfs4_free_lock_state(server, lsp);
 }
 
 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)