[mirror_ubuntu-bionic-kernel.git] / fs / nfs / nfs4super.c

/*
 * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/nfs4_mount.h>
#include <linux/nfs_fs.h>
#include "delegation.h"
#include "internal.h"
#include "nfs4_fs.h"
#include "nfs4idmap.h"
#include "dns_resolve.h"
#include "pnfs.h"
#include "nfs.h"

#define NFSDBG_FACILITY		NFSDBG_VFS

static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
static void nfs4_evict_inode(struct inode *inode);
static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data);
static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data);
static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data);

static struct file_system_type nfs4_remote_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.mount		= nfs4_remote_mount,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
};

static struct file_system_type nfs4_remote_referral_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.mount		= nfs4_remote_referral_mount,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
};

struct file_system_type nfs4_referral_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "nfs4",
	.mount		= nfs4_referral_mount,
	.kill_sb	= nfs_kill_super,
	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
};

static const struct super_operations nfs4_sops = {
	.alloc_inode	= nfs_alloc_inode,
	.destroy_inode	= nfs_destroy_inode,
	.write_inode	= nfs4_write_inode,
	.drop_inode	= nfs_drop_inode,
	.statfs		= nfs_statfs,
	.evict_inode	= nfs4_evict_inode,
	.umount_begin	= nfs_umount_begin,
	.show_options	= nfs_show_options,
	.show_devname	= nfs_show_devname,
	.show_path	= nfs_show_path,
	.show_stats	= nfs_show_stats,
	.remount_fs	= nfs_remount,
};

struct nfs_subversion nfs_v4 = {
	.owner = THIS_MODULE,
	.nfs_fs   = &nfs4_fs_type,
	.rpc_vers = &nfs_version4,
	.rpc_ops  = &nfs_v4_clientops,
	.sops     = &nfs4_sops,
	.xattr    = nfs4_xattr_handlers,
};

static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
{
	int ret = nfs_write_inode(inode, wbc);

	if (ret == 0)
		ret = pnfs_layoutcommit_inode(inode,
				wbc->sync_mode == WB_SYNC_ALL);
	return ret;
}

/*
 * 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_evict_inode(struct inode *inode)
{
	truncate_inode_pages_final(&inode->i_data);
	clear_inode(inode);
	/* If we are holding a delegation, return it! */
	nfs_inode_return_delegation_noreclaim(inode);
	/* Note that above delegreturn would trigger pnfs return-on-close */
	pnfs_return_layout(inode);
	pnfs_destroy_layout(NFS_I(inode));
	/* First call standard NFS clear_inode() code */
	nfs_clear_inode(inode);
}

/*
 * Get the superblock for the NFS4 root partition
 */
static struct dentry *
nfs4_remote_mount(struct file_system_type *fs_type, int flags,
		  const char *dev_name, void *info)
{
	struct nfs_mount_info *mount_info = info;
	struct nfs_server *server;
	struct dentry *mntroot = ERR_PTR(-ENOMEM);

	mount_info->set_security = nfs_set_sb_security;

	/* Get a volume representation */
	server = nfs4_create_server(mount_info, &nfs_v4);
	if (IS_ERR(server)) {
		mntroot = ERR_CAST(server);
		goto out;
	}

	mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);

out:
	return mntroot;
}

static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
		int flags, void *data, const char *hostname)
{
	struct vfsmount *root_mnt;
	char *root_devname;
	size_t len;

	len = strlen(hostname) + 5;
	root_devname = kmalloc(len, GFP_KERNEL);
	if (root_devname == NULL)
		return ERR_PTR(-ENOMEM);
	/* Does hostname needs to be enclosed in brackets? */
	if (strchr(hostname, ':'))
		snprintf(root_devname, len, "[%s]:/", hostname);
	else
		snprintf(root_devname, len, "%s:/", hostname);
	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
	kfree(root_devname);
	return root_mnt;
}

struct nfs_referral_count {
	struct list_head list;
	const struct task_struct *task;
	unsigned int referral_count;
};

static LIST_HEAD(nfs_referral_count_list);
static DEFINE_SPINLOCK(nfs_referral_count_list_lock);

static struct nfs_referral_count *nfs_find_referral_count(void)
{
	struct nfs_referral_count *p;

	list_for_each_entry(p, &nfs_referral_count_list, list) {
		if (p->task == current)
			return p;
	}
	return NULL;
}

#define NFS_MAX_NESTED_REFERRALS 2

static int nfs_referral_loop_protect(void)
{
	struct nfs_referral_count *p, *new;
	int ret = -ENOMEM;

	new = kmalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		goto out;
	new->task = current;
	new->referral_count = 1;

	ret = 0;
	spin_lock(&nfs_referral_count_list_lock);
	p = nfs_find_referral_count();
	if (p != NULL) {
		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
			ret = -ELOOP;
		else
			p->referral_count++;
	} else {
		list_add(&new->list, &nfs_referral_count_list);
		new = NULL;
	}
	spin_unlock(&nfs_referral_count_list_lock);
	kfree(new);
out:
	return ret;
}

static void nfs_referral_loop_unprotect(void)
{
	struct nfs_referral_count *p;

	spin_lock(&nfs_referral_count_list_lock);
	p = nfs_find_referral_count();
	p->referral_count--;
	if (p->referral_count == 0)
		list_del(&p->list);
	else
		p = NULL;
	spin_unlock(&nfs_referral_count_list_lock);
	kfree(p);
}

static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
		const char *export_path)
{
	struct dentry *dentry;
	int err;

	if (IS_ERR(root_mnt))
		return ERR_CAST(root_mnt);

	err = nfs_referral_loop_protect();
	if (err) {
		mntput(root_mnt);
		return ERR_PTR(err);
	}

	dentry = mount_subtree(root_mnt, export_path);
	nfs_referral_loop_unprotect();

	return dentry;
}

struct dentry *nfs4_try_mount(int flags, const char *dev_name,
			      struct nfs_mount_info *mount_info,
			      struct nfs_subversion *nfs_mod)
{
	char *export_path;
	struct vfsmount *root_mnt;
	struct dentry *res;
	struct nfs_parsed_mount_data *data = mount_info->parsed;

	dfprintk(MOUNT, "--> nfs4_try_mount()\n");

	export_path = data->nfs_server.export_path;
	data->nfs_server.export_path = "/";
	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
			data->nfs_server.hostname);
	data->nfs_server.export_path = export_path;

	res = nfs_follow_remote_path(root_mnt, export_path);

	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
		 PTR_ERR_OR_ZERO(res),
		 IS_ERR(res) ? " [error]" : "");
	return res;
}

static struct dentry *
nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
			   const char *dev_name, void *raw_data)
{
	struct nfs_mount_info mount_info = {
		.fill_super = nfs_fill_super,
		.set_security = nfs_clone_sb_security,
		.cloned = raw_data,
	};
	struct nfs_server *server;
	struct dentry *mntroot = ERR_PTR(-ENOMEM);

	dprintk("--> nfs4_referral_get_sb()\n");

	mount_info.mntfh = nfs_alloc_fhandle();
	if (mount_info.cloned == NULL || mount_info.mntfh == NULL)
		goto out;

	/* create a new volume representation */
	server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
	if (IS_ERR(server)) {
		mntroot = ERR_CAST(server);
		goto out;
	}

	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
out:
	nfs_free_fhandle(mount_info.mntfh);
	return mntroot;
}

/*
 * Create an NFS4 server record on referral traversal
 */
static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
		int flags, const char *dev_name, void *raw_data)
{
	struct nfs_clone_mount *data = raw_data;
	char *export_path;
	struct vfsmount *root_mnt;
	struct dentry *res;

	dprintk("--> nfs4_referral_mount()\n");

	export_path = data->mnt_path;
	data->mnt_path = "/";

	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
			flags, data, data->hostname);
	data->mnt_path = export_path;

	res = nfs_follow_remote_path(root_mnt, export_path);
	dprintk("<-- nfs4_referral_mount() = %d%s\n",
		PTR_ERR_OR_ZERO(res),
		IS_ERR(res) ? " [error]" : "");
	return res;
}


static int __init init_nfs_v4(void)
{
	int err;

	err = nfs_dns_resolver_init();
	if (err)
		goto out;

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

	err = nfs4_register_sysctl();
	if (err)
		goto out2;

	register_nfs_version(&nfs_v4);
	return 0;
out2:
	nfs_idmap_quit();
out1:
	nfs_dns_resolver_destroy();
out:
	return err;
}

static void __exit exit_nfs_v4(void)
{
	/* Not called in the _init(), conditionally loaded */
	nfs4_pnfs_v3_ds_connect_unload();

	unregister_nfs_version(&nfs_v4);
	nfs4_unregister_sysctl();
	nfs_idmap_quit();
	nfs_dns_resolver_destroy();
}

MODULE_LICENSE("GPL");

module_init(init_nfs_v4);
module_exit(exit_nfs_v4);
Commit	Line	Data
129d1977 BS	1	/*
	2	* Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
	3	*/
	4	#include <linux/init.h>
fbdefd64	5	#include <linux/module.h>
fbdefd64	6	#include <linux/nfs4_mount.h>
466bfe7f	7	#include <linux/nfs_fs.h>
19d87ca3	8	#include "delegation.h"
fbdefd64	9	#include "internal.h"
466bfe7f	10	#include "nfs4_fs.h"
40c64c26	11	#include "nfs4idmap.h"
c8d74d9b	12	#include "dns_resolve.h"
19d87ca3	13	#include "pnfs.h"
ab7017a3	14	#include "nfs.h"
129d1977	15
fbdefd64 BS	16	#define NFSDBG_FACILITY NFSDBG_VFS
fbdefd64 BS	17
19d87ca3 BS	18	static int nfs4_write_inode(struct inode inode, struct writeback_control wbc);
19d87ca3 BS	19	static void nfs4_evict_inode(struct inode *inode);
fbdefd64 BS	20	static struct dentry nfs4_remote_mount(struct file_system_type fs_type,
fbdefd64 BS	21	int flags, const char dev_name, void raw_data);
fbdefd64 BS	22	static struct dentry nfs4_referral_mount(struct file_system_type fs_type,
	23	int flags, const char dev_name, void raw_data);
	24	static struct dentry nfs4_remote_referral_mount(struct file_system_type fs_type,
	25	int flags, const char dev_name, void raw_data);
	26
fbdefd64 BS	27	static struct file_system_type nfs4_remote_fs_type = {
	28	.owner = THIS_MODULE,
	29	.name = "nfs4",
	30	.mount = nfs4_remote_mount,
	31	.kill_sb = nfs_kill_super,
ecf3d1f1	32	.fs_flags = FS_RENAME_DOES_D_MOVE\|FS_BINARY_MOUNTDATA,
fbdefd64 BS	33	};
fbdefd64 BS	34
fbdefd64 BS	35	static struct file_system_type nfs4_remote_referral_fs_type = {
	36	.owner = THIS_MODULE,
	37	.name = "nfs4",
	38	.mount = nfs4_remote_referral_mount,
	39	.kill_sb = nfs_kill_super,
ecf3d1f1	40	.fs_flags = FS_RENAME_DOES_D_MOVE\|FS_BINARY_MOUNTDATA,
fbdefd64 BS	41	};
	42
	43	struct file_system_type nfs4_referral_fs_type = {
	44	.owner = THIS_MODULE,
	45	.name = "nfs4",
	46	.mount = nfs4_referral_mount,
	47	.kill_sb = nfs_kill_super,
ecf3d1f1	48	.fs_flags = FS_RENAME_DOES_D_MOVE\|FS_BINARY_MOUNTDATA,
fbdefd64 BS	49	};
	50
	51	static const struct super_operations nfs4_sops = {
	52	.alloc_inode = nfs_alloc_inode,
	53	.destroy_inode = nfs_destroy_inode,
	54	.write_inode = nfs4_write_inode,
eed99357	55	.drop_inode = nfs_drop_inode,
fbdefd64 BS	56	.statfs = nfs_statfs,
	57	.evict_inode = nfs4_evict_inode,
	58	.umount_begin = nfs_umount_begin,
	59	.show_options = nfs_show_options,
	60	.show_devname = nfs_show_devname,
	61	.show_path = nfs_show_path,
	62	.show_stats = nfs_show_stats,
	63	.remount_fs = nfs_remount,
	64	};
	65
ab7017a3 BS	66	struct nfs_subversion nfs_v4 = {
	67	.owner = THIS_MODULE,
	68	.nfs_fs = &nfs4_fs_type,
	69	.rpc_vers = &nfs_version4,
	70	.rpc_ops = &nfs_v4_clientops,
6a74490d BS	71	.sops = &nfs4_sops,
6a74490d BS	72	.xattr = nfs4_xattr_handlers,
ab7017a3 BS	73	};
ab7017a3 BS	74
19d87ca3 BS	75	static int nfs4_write_inode(struct inode inode, struct writeback_control wbc)
	76	{
	77	int ret = nfs_write_inode(inode, wbc);
	78
71244d9b TM	79	if (ret == 0)
	80	ret = pnfs_layoutcommit_inode(inode,
	81	wbc->sync_mode == WB_SYNC_ALL);
19d87ca3 BS	82	return ret;
	83	}
	84
	85	/*
	86	* Clean out any remaining NFSv4 state that might be left over due
	87	* to open() calls that passed nfs_atomic_lookup, but failed to call
	88	* nfs_open().
	89	*/
	90	static void nfs4_evict_inode(struct inode *inode)
	91	{
91b0abe3	92	truncate_inode_pages_final(&inode->i_data);
19d87ca3	93	clear_inode(inode);
19d87ca3 BS	94	/* If we are holding a delegation, return it! */
19d87ca3 BS	95	nfs_inode_return_delegation_noreclaim(inode);
415320fc TM	96	/* Note that above delegreturn would trigger pnfs return-on-close */
	97	pnfs_return_layout(inode);
	98	pnfs_destroy_layout(NFS_I(inode));
19d87ca3 BS	99	/* First call standard NFS clear_inode() code */
	100	nfs_clear_inode(inode);
	101	}
	102
fbdefd64 BS	103	/*
	104	* Get the superblock for the NFS4 root partition
	105	*/
	106	static struct dentry *
	107	nfs4_remote_mount(struct file_system_type *fs_type, int flags,
	108	const char dev_name, void info)
	109	{
	110	struct nfs_mount_info *mount_info = info;
	111	struct nfs_server *server;
	112	struct dentry *mntroot = ERR_PTR(-ENOMEM);
	113
fbdefd64 BS	114	mount_info->set_security = nfs_set_sb_security;
	115
	116	/* Get a volume representation */
1179acc6	117	server = nfs4_create_server(mount_info, &nfs_v4);
fbdefd64 BS	118	if (IS_ERR(server)) {
	119	mntroot = ERR_CAST(server);
	120	goto out;
	121	}
	122
ab7017a3	123	mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);
fbdefd64 BS	124
	125	out:
	126	return mntroot;
	127	}
	128
	129	static struct vfsmount nfs_do_root_mount(struct file_system_type fs_type,
	130	int flags, void data, const char hostname)
	131	{
	132	struct vfsmount *root_mnt;
	133	char *root_devname;
	134	size_t len;
	135
	136	len = strlen(hostname) + 5;
	137	root_devname = kmalloc(len, GFP_KERNEL);
	138	if (root_devname == NULL)
	139	return ERR_PTR(-ENOMEM);
	140	/* Does hostname needs to be enclosed in brackets? */
	141	if (strchr(hostname, ':'))
	142	snprintf(root_devname, len, "[%s]:/", hostname);
	143	else
	144	snprintf(root_devname, len, "%s:/", hostname);
	145	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
	146	kfree(root_devname);
	147	return root_mnt;
	148	}
	149
	150	struct nfs_referral_count {
	151	struct list_head list;
	152	const struct task_struct *task;
	153	unsigned int referral_count;
	154	};
	155
	156	static LIST_HEAD(nfs_referral_count_list);
	157	static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
	158
	159	static struct nfs_referral_count *nfs_find_referral_count(void)
	160	{
	161	struct nfs_referral_count *p;
	162
	163	list_for_each_entry(p, &nfs_referral_count_list, list) {
	164	if (p->task == current)
	165	return p;
	166	}
	167	return NULL;
	168	}
	169
	170	#define NFS_MAX_NESTED_REFERRALS 2
	171
	172	static int nfs_referral_loop_protect(void)
	173	{
	174	struct nfs_referral_count p, new;
	175	int ret = -ENOMEM;
	176
	177	new = kmalloc(sizeof(*new), GFP_KERNEL);
	178	if (!new)
	179	goto out;
	180	new->task = current;
	181	new->referral_count = 1;
	182
	183	ret = 0;
	184	spin_lock(&nfs_referral_count_list_lock);
	185	p = nfs_find_referral_count();
	186	if (p != NULL) {
	187	if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
188	ret = -ELOOP;
189	else
190	p->referral_count++;
191	} else {
192	list_add(&new->list, &nfs_referral_count_list);
193	new = NULL;
194	}
195	spin_unlock(&nfs_referral_count_list_lock);
196	kfree(new);
197	out:
198	return ret;
199	}
200
201	static void nfs_referral_loop_unprotect(void)
202	{
203	struct nfs_referral_count *p;
204
205	spin_lock(&nfs_referral_count_list_lock);
206	p = nfs_find_referral_count();
207	p->referral_count--;
208	if (p->referral_count == 0)
209	list_del(&p->list);
210	else
211	p = NULL;
212	spin_unlock(&nfs_referral_count_list_lock);
213	kfree(p);
214	}
215
216	static struct dentry nfs_follow_remote_path(struct vfsmount root_mnt,
217	const char *export_path)
218	{
219	struct dentry *dentry;
220	int err;
221
222	if (IS_ERR(root_mnt))
223	return ERR_CAST(root_mnt);
224
225	err = nfs_referral_loop_protect();
226	if (err) {
227	mntput(root_mnt);
228	return ERR_PTR(err);
229	}
230
231	dentry = mount_subtree(root_mnt, export_path);
232	nfs_referral_loop_unprotect();
233
234	return dentry;
235	}
236
237	struct dentry nfs4_try_mount(int flags, const char dev_name,
ff9099f2 BS	238	struct nfs_mount_info *mount_info,
ff9099f2 BS	239	struct nfs_subversion *nfs_mod)
fbdefd64 BS	240	{
	241	char *export_path;
	242	struct vfsmount *root_mnt;
	243	struct dentry *res;
	244	struct nfs_parsed_mount_data *data = mount_info->parsed;
	245
	246	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
	247
fbdefd64 BS	248	export_path = data->nfs_server.export_path;
	249	data->nfs_server.export_path = "/";
	250	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
	251	data->nfs_server.hostname);
	252	data->nfs_server.export_path = export_path;
	253
	254	res = nfs_follow_remote_path(root_mnt, export_path);
	255
6706246b GB	256	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
	257	PTR_ERR_OR_ZERO(res),
	258	IS_ERR(res) ? " [error]" : "");
fbdefd64 BS	259	return res;
	260	}
	261
fbdefd64 BS	262	static struct dentry *
	263	nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
	264	const char dev_name, void raw_data)
	265	{
	266	struct nfs_mount_info mount_info = {
6a74490d	267	.fill_super = nfs_fill_super,
fbdefd64 BS	268	.set_security = nfs_clone_sb_security,
	269	.cloned = raw_data,
	270	};
	271	struct nfs_server *server;
	272	struct dentry *mntroot = ERR_PTR(-ENOMEM);
	273
	274	dprintk("--> nfs4_referral_get_sb()\n");
	275
	276	mount_info.mntfh = nfs_alloc_fhandle();
	277	if (mount_info.cloned == NULL \|\| mount_info.mntfh == NULL)
	278	goto out;
	279
	280	/* create a new volume representation */
	281	server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
	282	if (IS_ERR(server)) {
	283	mntroot = ERR_CAST(server);
	284	goto out;
	285	}
	286
ab7017a3	287	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
fbdefd64 BS	288	out:
	289	nfs_free_fhandle(mount_info.mntfh);
	290	return mntroot;
	291	}
	292
	293	/*
	294	* Create an NFS4 server record on referral traversal
	295	*/
	296	static struct dentry nfs4_referral_mount(struct file_system_type fs_type,
	297	int flags, const char dev_name, void raw_data)
	298	{
	299	struct nfs_clone_mount *data = raw_data;
	300	char *export_path;
	301	struct vfsmount *root_mnt;
	302	struct dentry *res;
	303
	304	dprintk("--> nfs4_referral_mount()\n");
	305
	306	export_path = data->mnt_path;
	307	data->mnt_path = "/";
	308
	309	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
	310	flags, data, data->hostname);
	311	data->mnt_path = export_path;
	312
	313	res = nfs_follow_remote_path(root_mnt, export_path);
6706246b GB	314	dprintk("<-- nfs4_referral_mount() = %d%s\n",
	315	PTR_ERR_OR_ZERO(res),
	316	IS_ERR(res) ? " [error]" : "");
fbdefd64 BS	317	return res;
	318	}
	319
	320
89d77c8f	321	static int __init init_nfs_v4(void)
129d1977 BS	322	{
	323	int err;
	324
c8d74d9b	325	err = nfs_dns_resolver_init();
129d1977 BS	326	if (err)
	327	goto out;
	328
c8d74d9b	329	err = nfs_idmap_init();
466bfe7f BS	330	if (err)
	331	goto out1;
	332
c8d74d9b TM	333	err = nfs4_register_sysctl();
	334	if (err)
	335	goto out2;
	336
ab7017a3	337	register_nfs_version(&nfs_v4);
129d1977	338	return 0;
c8d74d9b	339	out2:
466bfe7f	340	nfs_idmap_quit();
c8d74d9b TM	341	out1:
c8d74d9b TM	342	nfs_dns_resolver_destroy();
129d1977 BS	343	out:
	344	return err;
	345	}
	346
89d77c8f	347	static void __exit exit_nfs_v4(void)
129d1977	348	{
5f01d953 PT	349	/* Not called in the _init(), conditionally loaded */
	350	nfs4_pnfs_v3_ds_connect_unload();
	351
ab7017a3	352	unregister_nfs_version(&nfs_v4);
466bfe7f	353	nfs4_unregister_sysctl();
129d1977	354	nfs_idmap_quit();
c8d74d9b	355	nfs_dns_resolver_destroy();
129d1977	356	}
89d77c8f BS	357
	358	MODULE_LICENSE("GPL");
	359
	360	module_init(init_nfs_v4);
	361	module_exit(exit_nfs_v4);