path: root/fs/nfs/nfs4state.c

/*
 *  fs/nfs/nfs4state.c
 *
 *  Client-side XDR for NFSv4.
 *
 *  Copyright (c) 2002 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <kmsmith@umich.edu>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Implementation of the NFSv4 state model.  For the time being,
 * this is minimal, but will be made much more complex in a
 * subsequent patch.
 */

#include <linux/config.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_idmap.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>

#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"

#define OPENOWNER_POOL_SIZE	8

const nfs4_stateid zero_stateid;

static DEFINE_SPINLOCK(state_spinlock);
static LIST_HEAD(nfs4_clientid_list);

static void nfs4_recover_state(void *);

void
init_nfsv4_state(struct nfs_server *server)
{
	server->nfs4_state = NULL;
	INIT_LIST_HEAD(&server->nfs4_siblings);
}

void
destroy_nfsv4_state(struct nfs_server *server)
{
	if (server->mnt_path) {
		kfree(server->mnt_path);
		server->mnt_path = NULL;
	}
	if (server->nfs4_state) {
		nfs4_put_client(server->nfs4_state);
		server->nfs4_state = NULL;
	}
}

/*
 * nfs4_get_client(): returns an empty client structure
 * nfs4_put_client(): drops reference to client structure
 *
 * Since these are allocated/deallocated very rarely, we don't
 * bother putting them in a slab cache...
 */
static struct nfs4_client *
nfs4_alloc_client(struct in_addr *addr)
{
	struct nfs4_client *clp;

	if (nfs_callback_up() < 0)
		return NULL;
	if ((clp = kmalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
		nfs_callback_down();
		return NULL;
	}
	memset(clp, 0, sizeof(*clp));
	memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
	init_rwsem(&clp->cl_sem);
	INIT_LIST_HEAD(&clp->cl_delegations);
	INIT_LIST_HEAD(&clp->cl_state_owners);
	INIT_LIST_HEAD(&clp->cl_unused);
	spin_lock_init(&clp->cl_lock);
	atomic_set(&clp->cl_count, 1);
	INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
	INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
	INIT_LIST_HEAD(&clp->cl_superblocks);
	init_waitqueue_head(&clp->cl_waitq);
	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
	clp->cl_rpcclient = ERR_PTR(-EINVAL);
	clp->cl_boot_time = CURRENT_TIME;
	clp->cl_state = 1 << NFS4CLNT_OK;
	return clp;
}

static void
nfs4_free_client(struct nfs4_client *clp)
{
	struct nfs4_state_owner *sp;

	while (!list_empty(&clp->cl_unused)) {
		sp = list_entry(clp->cl_unused.next,
				struct nfs4_state_owner,
				so_list);
		list_del(&sp->so_list);
		kfree(sp);
	}
	BUG_ON(!list_empty(&clp->cl_state_owners));
	if (clp->cl_cred)
		put_rpccred(clp->cl_cred);
	nfs_idmap_delete(clp);
	if (!IS_ERR(clp->cl_rpcclient))
		rpc_shutdown_client(clp->cl_rpcclient);
	kfree(clp);
	nfs_callback_down();
}

static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
{
	struct nfs4_client *clp;
	list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
		if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
			atomic_inc(&clp->cl_count);
			return clp;
		}
	}
	return NULL;
}

struct nfs4_client *nfs4_find_client(struct in_addr *addr)
{
	struct nfs4_client *clp;
	spin_lock(&state_spinlock);
	clp = __nfs4_find_client(addr);
	spin_unlock(&state_spinlock);
	return clp;
}

struct nfs4_client *
nfs4_get_client(struct in_addr *addr)
{
	struct nfs4_client *clp, *new = NULL;

	spin_lock(&state_spinlock);
	for (;;) {
		clp = __nfs4_find_client(addr);
		if (clp