inode.c

	.get_sb		= nfs_clone_nfs_sb,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};

#ifdef CONFIG_NFS_V4

static void nfs4_clear_inode(struct inode *);


static struct super_operations nfs4_sops = { 
	.alloc_inode	= nfs_alloc_inode,
	.destroy_inode	= nfs_destroy_inode,
	.write_inode	= nfs_write_inode,
	.statfs		= nfs_statfs,
	.clear_inode	= nfs4_clear_inode,
	.umount_begin	= nfs_umount_begin,
	.show_options	= nfs_show_options,
	.show_stats	= nfs_show_stats,
};

/*
 * Clean out any remaining NFSv4 state that might be left over due
 * to open() calls that passed nfs_atomic_lookup, but failed to call
 * nfs_open().
 */
static void nfs4_clear_inode(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);

	/* If we are holding a delegation, return it! */
	nfs_inode_return_delegation(inode);
	/* First call standard NFS clear_inode() code */
	nfs_clear_inode(inode);
	/* Now clear out any remaining state */
	while (!list_empty(&nfsi->open_states)) {
		struct nfs4_state *state;
		
		state = list_entry(nfsi->open_states.next,
				struct nfs4_state,
				inode_states);
		dprintk("%s(%s/%Ld): found unclaimed NFSv4 state %p\n",
				__FUNCTION__,
				inode->i_sb->s_id,
				(long long)NFS_FILEID(inode),
				state);
		BUG_ON(atomic_read(&state->count) != 1);
		nfs4_close_state(state, state->state);
	}
}


static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
	struct rpc_timeout *timeparms, int proto, rpc_authflavor_t flavor)
{
	struct nfs4_client *clp;
	struct rpc_xprt *xprt = NULL;
	struct rpc_clnt *clnt = NULL;
	int err = -EIO;

	clp = nfs4_get_client(&server->addr.sin_addr);
	if (!clp) {
		dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
		return ERR_PTR(err);
	}

	/* Now create transport and client */
	down_write(&clp->cl_sem);
	if (IS_ERR(clp->cl_rpcclient)) {
		xprt = xprt_create_proto(proto, &server->addr, timeparms);
		if (IS_ERR(xprt)) {
			up_write(&clp->cl_sem);
			err = PTR_ERR(xprt);
			dprintk("%s: cannot create RPC transport. Error = %d\n",
					__FUNCTION__, err);
			goto out_fail;
		}
		clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
				server->rpc_ops->version, flavor);
		if (IS_ERR(clnt)) {
			up_write(&clp->cl_sem);
			err = PTR_ERR(clnt);
			dprintk("%s: cannot create RPC client. Error = %d\n",
					__FUNCTION__, err);
			goto out_fail;
		}
		clnt->cl_intr     = 1;
		clnt->cl_softrtry = 1;
		clp->cl_rpcclient = clnt;
		memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
		nfs_idmap_new(clp);
	}
	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
	clnt = rpc_clone_client(clp->cl_rpcclient);
	if (!IS_ERR(clnt))
		server->nfs4_state = clp;
	up_write(&clp->cl_sem);
	clp = NULL;

	if (IS_ERR(clnt)) {
		dprintk("%s: cannot create RPC client. Error = %d\n",
				__FUNCTION__, err);
		return clnt;
	}

	if (server->nfs4_state->cl_idmap == NULL) {
		dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
		return ERR_PTR(-ENOMEM);
	}

	if (clnt->cl_auth->au_flavor != flavor) {
		struct rpc_auth *auth;

		auth = rpcauth_create(flavor, clnt);
		if (IS_ERR(auth)) {
			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
			return (struct rpc_clnt *)auth;
		}
	}
	return clnt;

 out_fail:
	if (clp)
		nfs4_put_client(clp);
	return ERR_PTR(err);
}

static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
{
	struct nfs_server *server;
	struct rpc_timeout timeparms;
	rpc_authflavor_t authflavour;
	int err = -EIO;

	sb->s_blocksize_bits = 0;
	sb->s_blocksize = 0;
	server = NFS_SB(sb);
	if (data->rsize != 0)
		server->rsize = nfs_block_size(data->rsize, NULL);
	if (data->wsize != 0)
		server->wsize = nfs_block_size(data->wsize, NULL);
	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
	server->caps = NFS_CAP_ATOMIC_OPEN;

	server->acregmin = data->acregmin*HZ;
	server->acregmax = data->acregmax*HZ;
	server->acdirmin = data->acdirmin*HZ;
	server->acdirmax = data->acdirmax*HZ;

	server->rpc_ops = &nfs_v4_clientops;

	nfs_init_timeout_values(&timeparms, data->proto, data->timeo, data->retrans);

	server->retrans_timeo = timeparms.to_initval;
	server->retrans_count = timeparms.to_retries;

	/* Now create transport and client */
	authflavour = RPC_AUTH_UNIX;
	if (data->auth_flavourlen != 0) {
		if (data->auth_flavourlen != 1) {
			dprintk("%s: Invalid number of RPC auth flavours %d.\n",
					__FUNCTION__, data->auth_flavourlen);
			err = -EINVAL;
			goto out_fail;
		}
		if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
			err = -EFAULT;
			goto out_fail;
		}
	}

	server->client = nfs4_create_client(server, &timeparms, data->proto, authflavour);
	if (IS_ERR(server->client)) {
		err = PTR_ERR(server->client);
			dprintk("%s: cannot create RPC client. Error = %d\n",
					__FUNCTION__, err);
			goto out_fail;
	}

	sb->s_time_gran = 1;

	sb->s_op = &nfs4_sops;
	err = nfs_sb_init(sb, authflavour);

 out_fail:
	return err;
}

static int nfs4_compare_super(struct super_block *sb, void *data)
{
	struct nfs_server *server = data;
	struct nfs_server *old = NFS_SB(sb);

	if (strcmp(server->hostname, old->hostname) != 0)
		return 0;
	if (strcmp(server->mnt_path, old->mnt_path) != 0)
		return 0;
	return 1;
}

static void *
nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
{
	void *p = NULL;

	if (!src->len)
		return ERR_PTR(-EINVAL);
	if (src->len < maxlen)
		maxlen = src->len;
	if (dst == NULL) {
		p = dst = kmalloc(maxlen + 1, GFP_KERNEL);
		if (p == NULL)
			return ERR_PTR(-ENOMEM);
	}
	if (copy_from_user(dst, src->data, maxlen)) {
		kfree(p);
		return ERR_PTR(-EFAULT);
	}
	dst[maxlen] = '\0';
	return dst;
}

static struct super_block *nfs4_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data)
{
	int error;
	struct nfs_server *server;
	struct super_block *s;
	struct nfs4_mount_data *data = raw_data;
	void *p;

	if (data == NULL) {
		dprintk("%s: missing data argument\n", __FUNCTION__);
		return ERR_PTR(-EINVAL);
	}
	if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
		dprintk("%s: bad mount version\n", __FUNCTION__);
		return ERR_PTR(-EINVAL);
	}

	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
	if (!server)
		return ERR_PTR(-ENOMEM);
	/* Zero out the NFS state stuff */
	init_nfsv4_state(server);
	server->client = server->client_sys = server->client_acl = ERR_PTR(-EINVAL);

	p = nfs_copy_user_string(NULL, &data->hostname, 256);
	if (IS_ERR(p))
		goto out_err;
	server->hostname = p;

	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
	if (IS_ERR(p))
		goto out_err;
	server->mnt_path = p;

	p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
			sizeof(server->ip_addr) - 1);
	if (IS_ERR(p))
		goto out_err;

	/* We now require that the mount process passes the remote address */
	if (data->host_addrlen != sizeof(server->addr)) {
		s = ERR_PTR(-EINVAL);
		goto out_free;
	}
	if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
		s = ERR_PTR(-EFAULT);
		goto out_free;
	}
	if (server->addr.sin_family != AF_INET ||
	    server->addr.sin_addr.s_addr == INADDR_ANY) {
		dprintk("%s: mount program didn't pass remote IP address!\n",
				__FUNCTION__);
		s = ERR_PTR(-EINVAL);
		goto out_free;
	}

	/* Fire up rpciod if not yet running */
	s = ERR_PTR(rpciod_up());
	if (IS_ERR(s)) {
		dprintk("%s: couldn't start rpciod! Error = %ld\n",
				__FUNCTION__, PTR_ERR(s));
		goto out_free;
	}

	s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);

	if (IS_ERR(s) || s->s_root)
		goto out_free;

	s->s_flags = flags;

	error = nfs4_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
	if (error) {
		up_write(&s->s_umount);
		deactivate_super(s);
		return ERR_PTR(error);
	}
	s->s_flags |= MS_ACTIVE;
	return s;
out_err:
	s = (struct super_block *)p;
out_free:
	kfree(server->mnt_path);
	kfree(server->hostname);
	kfree(server);
	return s;
}

static void nfs4_kill_super(struct super_block *sb)
{
	struct nfs_server *server = NFS_SB(sb);

	nfs_return_all_delegations(sb);
	kill_anon_super(sb);

	nfs4_renewd_prepare_shutdown(server);

	if (server->client != NULL && !IS_ERR(server->client))
		rpc_shutdown_client(server->client);

	destroy_nfsv4_state(server);

	rpciod_down();

	nfs_free_iostats(server->io_stats);
	kfree(server->hostname);
	kfree(server);
	nfs_release_automount_timer();
}

static struct file_system_type nfs4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.get_sb		= nfs4_get_sb,
	.kill_sb	= nfs4_kill_super,
	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};

static const int nfs_set_port_min = 0;
static const int nfs_set_port_max = 65535;
static int param_set_port(const char *val, struct kernel_param *kp)
{
	char *endp;
	int num = simple_strtol(val, &endp, 0);
	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
		return -EINVAL;
	*((int *)kp->arg) = num;
	return 0;
}

module_param_call(callback_tcpport, param_set_port, param_get_int,
		 &nfs_callback_set_tcpport, 0644);

static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
{
	char *endp;
	int num = simple_strtol(val, &endp, 0);
	int jif = num * HZ;
	if (endp == val || *endp || num < 0 || jif < num)
		return -EINVAL;
	*((int *)kp->arg) = jif;
	return 0;
}

module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
		 &nfs_idmap_cache_timeout, 0644);

/* Constructs the SERVER-side path */
static inline char *nfs4_path(const struct dentry *dentry, char *buffer, ssize_t buflen)
{
	return nfs_path(NFS_SB(dentry->d_sb)->mnt_path, dentry, buffer, buflen);
}

static inline char *nfs4_dup_path(const struct dentry *dentry)
{
	char *page = (char *) __get_free_page(GFP_USER);
	char *path;

	path = nfs4_path(dentry, page, PAGE_SIZE);
	if (!IS_ERR(path)) {
		int len = PAGE_SIZE + page - path;
		char *tmp = path;

		path = kmalloc(len, GFP_KERNEL);
		if (path)
			memcpy(path, tmp, len);
		else
			path = ERR_PTR(-ENOMEM);
	}
	free_page((unsigned long)page);
	return path;
}

static struct super_block *nfs4_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
{
	const struct dentry *dentry = data->dentry;
	struct nfs4_client *clp = server->nfs4_state;
	struct super_block *sb;

	server->fsid = data->fattr->fsid;
	nfs_copy_fh(&server->fh, data->fh);
	server->mnt_path = nfs4_dup_path(dentry);
	if (IS_ERR(server->mnt_path)) {
		sb = (struct super_block *)server->mnt_path;
		goto err;
	}
	sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
	if (IS_ERR(sb) || sb->s_root)
		goto free_path;
	nfs4_server_capabilities(server, &server->fh);

	down_write(&clp->cl_sem);
	atomic_inc(&clp->cl_count);
	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
	up_write(&clp->cl_sem);
	return sb;
free_path:
	kfree(server->mnt_path);
err:
	server->mnt_path = NULL;
	return sb;
}

static struct super_block *nfs_clone_nfs4_sb(struct file_system_type *fs_type,
		int flags, const char *dev_name, void *raw_data)
{
	struct nfs_clone_mount *data = raw_data;
	return nfs_clone_generic_sb(data, nfs4_clone_sb, nfs_clone_server);
}

static struct file_system_type clone_nfs4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.get_sb		= nfs_clone_nfs4_sb,
	.kill_sb	= nfs4_kill_super,
	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};

#define nfs4_init_once(nfsi) \
	do { \
		INIT_LIST_HEAD(&(nfsi)->open_states); \
		nfsi->delegation = NULL; \
		nfsi->delegation_state = 0; \
		init_rwsem(&nfsi->rwsem); \
	} while(0)

static inline int register_nfs4fs(void)
{
	int ret;

	ret = nfs_register_sysctl();
	if (ret != 0)
		return ret;
	ret = register_filesystem(&nfs4_fs_type);
	if (ret != 0)
		nfs_unregister_sysctl();
	return ret;
}

static inline void unregister_nfs4fs(void)
{
	unregister_filesystem(&nfs4_fs_type);
	nfs_unregister_sysctl();
}
#else
#define nfs4_fill_sb(a,b)	ERR_PTR(-EINVAL)
#define nfs4_fill_super(a,b)	ERR_PTR(-EINVAL)
#define nfs4_init_once(nfsi) \
	do { } while (0)
#define register_nfs4fs() (0)
#define unregister_nfs4fs()
#endif

static inline char *nfs_devname(const struct vfsmount *mnt_parent,
			 const struct dentry *dentry,
			 char *buffer, ssize_t buflen)
{
	return nfs_path(mnt_parent->mnt_devname, dentry, buffer, buflen);
}

/**
 * nfs_do_submount - set up mountpoint when crossing a filesystem boundary
 * @mnt_parent - mountpoint of parent directory
 * @dentry - parent directory
 * @fh - filehandle for new root dentry
 * @fattr - attributes for new root inode
 *
 */
struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
		const struct dentry *dentry, struct nfs_fh *fh,
		struct nfs_fattr *fattr)
{
	struct nfs_clone_mount mountdata = {
		.sb = mnt_parent->mnt_sb,
		.dentry = dentry,
		.fh = fh,
		.fattr = fattr,
	};
	struct vfsmount *mnt = ERR_PTR(-ENOMEM);
	char *page = (char *) __get_free_page(GFP_USER);
	char *devname;

	dprintk("%s: submounting on %s/%s\n", __FUNCTION__,
			dentry->d_parent->d_name.name,
			dentry->d_name.name);
	if (page == NULL)
		goto out;
	devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
	mnt = (struct vfsmount *)devname;
	if (IS_ERR(devname))
		goto free_page;
	switch (NFS_SB(mnt_parent->mnt_sb)->rpc_ops->version) {
		case 2:
		case 3:
			mnt = vfs_kern_mount(&clone_nfs_fs_type, 0, devname, &mountdata);
			break;
		case 4:
			mnt = vfs_kern_mount(&clone_nfs4_fs_type, 0, devname, &mountdata);
			break;
		default:
			BUG();
	}
free_page:
	free_page((unsigned long)page);
out:
	dprintk("%s: done\n", __FUNCTION__);
	return mnt;
}

/* Check if fs_root is valid */
static inline char *nfs4_pathname_string(struct nfs4_pathname *pathname, char *buffer, ssize_t buflen)
{
	char *end = buffer + buflen;
	int n;

	*--end = '\0';
	buflen--;

	n = pathname->ncomponents;
	while (--n >= 0) {
		struct nfs4_string *component = &pathname->components[n];
		buflen -= component->len + 1;
		if (buflen < 0)
			goto Elong;
		end -= component->len;
		memcpy(end, component->data, component->len);
		*--end = '/';
	}
	return end;
Elong:
	return ERR_PTR(-ENAMETOOLONG);
}

/* Check if the string represents a "valid" IPv4 address */
static inline int valid_ipaddr4(const char *buf)
{
	int rc, count, in[4];

	rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
	if (rc != 4)
		return -EINVAL;
	for (count = 0; count < 4; count++) {
		if (in[count] > 255)
			return -EINVAL;
	}
	return 0;
}

static struct super_block *nfs4_referral_sb(struct nfs_server *server, struct nfs_clone_mount *data)
{
	struct super_block *sb = ERR_PTR(-ENOMEM);
	int len;

	len = strlen(data->mnt_path) + 1;
	server->mnt_path = kmalloc(len, GFP_KERNEL);
	if (server->mnt_path == NULL)
		goto err;
	memcpy(server->mnt_path, data->mnt_path, len);
	memcpy(&server->addr, data->addr, sizeof(struct sockaddr_in));

	sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
	if (IS_ERR(sb) || sb->s_root)
		goto free_path;
	return sb;
free_path:
	kfree(server->mnt_path);
err:
	server->mnt_path = NULL;
	return sb;
}

static struct nfs_server *nfs4_referral_server(struct super_block *sb, struct nfs_clone_mount *data)
{
	struct nfs_server *server = NFS_SB(sb);
	struct rpc_timeout timeparms;
	int proto, timeo, retrans;
	void *err;

	proto = IPPROTO_TCP;
	/* Since we are following a referral and there may be alternatives,
	   set the timeouts and retries to low values */
	timeo = 2;
	retrans = 1;
	nfs_init_timeout_values(&timeparms, proto, timeo, retrans);

	server->client = nfs4_create_client(server, &timeparms, proto, data->authflavor);
	if (IS_ERR((err = server->client)))
		goto out_err;

	sb->s_time_gran = 1;
	sb->s_op = &nfs4_sops;
	err = ERR_PTR(nfs_sb_init(sb, data->authflavor));
	if (!IS_ERR(err))
		return server;
out_err:
	return (struct nfs_server *)err;
}

static struct super_block *nfs_referral_nfs4_sb(struct file_system_type *fs_type,
		int flags, const char *dev_name, void *raw_data)
{
	struct nfs_clone_mount *data = raw_data;
	return nfs_clone_generic_sb(data, nfs4_referral_sb, nfs4_referral_server);
}

static struct file_system_type nfs_referral_nfs4_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.get_sb		= nfs_referral_nfs4_sb,
	.kill_sb	= nfs4_kill_super,
	.fs_flags	= FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
};

/**
 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
 * @mnt_parent - mountpoint of parent directory
 * @dentry - parent directory
 * @fspath - fs path returned in fs_locations
 * @mntpath - mount path to new server
 * @hostname - hostname of new server
 * @addr - host addr of new server
 *
 */
struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
	     const struct dentry *dentry, struct nfs4_fs_locations *locations)
{
	struct vfsmount *mnt = ERR_PTR(-ENOENT);
	struct nfs_clone_mount mountdata = {
		.sb = mnt_parent->mnt_sb,
		.dentry = dentry,
		.authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
	};
	char *page, *page2;
	char *path, *fs_path;
	char *devname;
	int loc, s;

	if (locations == NULL || locations->nlocations <= 0)
		goto out;

	dprintk("%s: referral at %s/%s\n", __FUNCTION__,
		dentry->d_parent->d_name.name, dentry->d_name.name);

	/* Ensure fs path is a prefix of current dentry path */
	page = (char *) __get_free_page(GFP_USER);
	if (page == NULL)
		goto out;
	page2 = (char *) __get_free_page(GFP_USER);
	if (page2 == NULL)
		goto out;

	path = nfs4_path(dentry, page, PAGE_SIZE);
	if (IS_ERR(path))
		goto out_free;

	fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
	if (IS_ERR(fs_path))
		goto out_free;

	if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
		dprintk("%s: path %s does not begin with fsroot %s\n", __FUNCTION__, path, fs_path);
		goto out_free;
	}

	devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
	if (IS_ERR(devname)) {
		mnt = (struct vfsmount *)devname;
		goto out_free;
	}

	loc = 0;
	while (loc < locations->nlocations && IS_ERR(mnt)) {
		struct nfs4_fs_location *location = &locations->locations[loc];
		char *mnt_path;

		if (location == NULL || location->nservers <= 0 ||
		    location->rootpath.ncomponents == 0) {
			loc++;
			continue;
		}

		mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
		if (IS_ERR(mnt_path)) {
			loc++;
			continue;
		}
		mountdata.mnt_path = mnt_path;

		s = 0;
		while (s < location->nservers) {
			struct sockaddr_in addr = {};

			if (location->servers[s].len <= 0 ||
			    valid_ipaddr4(location->servers[s].data) < 0) {
				s++;
				continue;
			}

			mountdata.hostname = location->servers[s].data;
			addr.sin_addr.s_addr = in_aton(mountdata.hostname);
			addr.sin_family = AF_INET;
			addr.sin_port = htons(NFS_PORT);
			mountdata.addr = &addr;

			mnt = vfs_kern_mount(&nfs_referral_nfs4_fs_type, 0, devname, &mountdata);
			if (!IS_ERR(mnt)) {
				break;
			}
			s++;
		}
		loc++;
	}

out_free:
	free_page((unsigned long)page);
	free_page((unsigned long)page2);
out:
	dprintk("%s: done\n", __FUNCTION__);
	return mnt;
}

/*
 * nfs_do_refmount - handle crossing a referral on server
 * @dentry - dentry of referral
 * @nd - nameidata info
 *
 */
struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
{
	struct vfsmount *mnt = ERR_PTR(-ENOENT);
	struct dentry *parent;
	struct nfs4_fs_locations *fs_locations = NULL;
	struct page *page;
	int err;

	/* BUG_ON(IS_ROOT(dentry)); */
	dprintk("%s: enter\n", __FUNCTION__);

	page = alloc_page(GFP_KERNEL);
	if (page == NULL)
		goto out;

	fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
	if (fs_locations == NULL)
		goto out_free;

	/* Get locations */
	parent = dget_parent(dentry);
	dprintk("%s: getting locations for %s/%s\n", __FUNCTION__, parent->d_name.name, dentry->d_name.name);
	err = nfs4_proc_fs_locations(parent->d_inode, dentry, fs_locations, page);
	dput(parent);
	if (err != 0 || fs_locations->nlocations <= 0 ||
	    fs_locations->fs_path.ncomponents <= 0)
		goto out_free;

	mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
out_free:
	__free_page(page);
	kfree(fs_locations);
out:
	dprintk("%s: done\n", __FUNCTION__);
	return mnt;
}

extern int nfs_init_nfspagecache(void);
extern void nfs_destroy_nfspagecache(void);
extern int nfs_init_readpagecache(void);
extern void nfs_destroy_readpagecache(void);
extern int nfs_init_writepagecache(void);
extern void nfs_destroy_writepagecache(void);
#ifdef CONFIG_NFS_DIRECTIO
extern int nfs_init_directcache(void);
extern void nfs_destroy_directcache(void);
#endif

static kmem_cache_t * nfs_inode_cachep;

static struct inode *nfs_alloc_inode(struct super_block *sb)
{
	struct nfs_inode *nfsi;
	nfsi = (struct nfs_inode *)kmem_cache_alloc(nfs_inode_cachep, SLAB_KERNEL);
	if (!nfsi)
		return NULL;
	nfsi->flags = 0UL;
	nfsi->cache_validity = 0UL;
	nfsi->cache_change_attribute = jiffies;
#ifdef CONFIG_NFS_V3_ACL
	nfsi->acl_access = ERR_PTR(-EAGAIN);
	nfsi->acl_default = ERR_PTR(-EAGAIN);
#endif
#ifdef CONFIG_NFS_V4
	nfsi->nfs4_acl = NULL;
#endif /* CONFIG_NFS_V4 */
	return &nfsi->vfs_inode;
}

static void nfs_destroy_inode(struct inode *inode)
{
	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
}

static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
{
	struct nfs_inode *nfsi = (struct nfs_inode *) foo;

	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
	    SLAB_CTOR_CONSTRUCTOR) {
		inode_init_once(&nfsi->vfs_inode);
		spin_lock_init(&nfsi->req_lock);
		INIT_LIST_HEAD(&nfsi->dirty);
		INIT_LIST_HEAD(&nfsi->commit);
		INIT_LIST_HEAD(&nfsi->open_files);
		INIT_RADIX_TREE(&nfsi->nfs_page_tree, GFP_ATOMIC);
		atomic_set(&nfsi->data_updates, 0);
		nfsi->ndirty = 0;
		nfsi->ncommit = 0;
		nfsi->npages = 0;
		nfs4_init_once(nfsi);
	}
}
 
static int nfs_init_inodecache(void)
{
	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
					     sizeof(struct nfs_inode),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once, NULL);
	if (nfs_inode_cachep == NULL)
		return -ENOMEM;

	return 0;
}

static void nfs_destroy_inodecache(void)
{
	if (kmem_cache_destroy(nfs_inode_cachep))
		printk(KERN_INFO "nfs_inode_cache: not all structures were freed\n");
}

/*
 * Initialize NFS
 */
static int __init init_nfs_fs(void)
{
	int err;

	err = nfs_init_nfspagecache();
	if (err)
		goto out4;

	err = nfs_init_inodecache();
	if (err)
		goto out3;

	err = nfs_init_readpagecache();
	if (err)
		goto out2;

	err = nfs_init_writepagecache();
	if (err)
		goto out1;

#ifdef CONFIG_NFS_DIRECTIO
	err = nfs_init_directcache();
	if (err)
		goto out0;
#endif

#ifdef CONFIG_PROC_FS
	rpc_proc_register(&nfs_rpcstat);
#endif
        err = register_filesystem(&nfs_fs_type);
	if (err)
		goto out;
	if ((err = register_nfs4fs()) != 0)
		goto out;
	return 0;
out:
#ifdef CONFIG_PROC_FS
	rpc_proc_unregister("nfs");
#endif
#ifdef CONFIG_NFS_DIRECTIO
	nfs_destroy_directcache();
out0:
#endif
	nfs_destroy_writepagecache();
out1:
	nfs_destroy_readpagecache();
out2:
	nfs_destroy_inodecache();
out3:
	nfs_destroy_nfspagecache();
out4:
	return err;
}

static void __exit exit_nfs_fs(void)
{
#ifdef CONFIG_NFS_DIRECTIO
	nfs_destroy_directcache();
#endif
	nfs_destroy_writepagecache();
	nfs_destroy_readpagecache();
	nfs_destroy_inodecache();
	nfs_destroy_nfspagecache();
#ifdef CONFIG_PROC_FS
	rpc_proc_unregister("nfs");
#endif
	unregister_filesystem(&nfs_fs_type);
	unregister_nfs4fs();
}

/* Not quite true; I just maintain it */
MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
MODULE_LICENSE("GPL");

module_init(init_nfs_fs)
module_exit(exit_nfs_fs)