inode.c

	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);
}

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);

#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_init_once(nfsi) \
	do { } while (0)
#define register_nfs4fs() (0)
#define unregister_nfs4fs()
#endif

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)