[deliverable/linux.git] / fs / nfs / nfs4super.c

/*
 * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/nfs_idmap.h>
#include <linux/nfs4_mount.h>
#include <linux/nfs_fs.h>
#include "delegation.h"
#include "internal.h"
#include "nfs4_fs.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);
	pnfs_return_layout(inode);
	pnfs_destroy_layout(NFS_I(inode));
	/* If we are holding a delegation, return it! */
	nfs_inode_return_delegation_noreclaim(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>
129d1977	6	#include <linux/nfs_idmap.h>
fbdefd64	7	#include <linux/nfs4_mount.h>
466bfe7f	8	#include <linux/nfs_fs.h>
19d87ca3	9	#include "delegation.h"
fbdefd64	10	#include "internal.h"
466bfe7f	11	#include "nfs4_fs.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 BS	93	clear_inode(inode);
	94	pnfs_return_layout(inode);
	95	pnfs_destroy_layout(NFS_I(inode));
	96	/* If we are holding a delegation, return it! */
	97	nfs_inode_return_delegation_noreclaim(inode);
	98	/* First call standard NFS clear_inode() code */
	99	nfs_clear_inode(inode);
	100	}
	101
fbdefd64 BS	102	/*
	103	* Get the superblock for the NFS4 root partition
	104	*/
	105	static struct dentry *
	106	nfs4_remote_mount(struct file_system_type *fs_type, int flags,
	107	const char dev_name, void info)
	108	{
	109	struct nfs_mount_info *mount_info = info;
	110	struct nfs_server *server;
	111	struct dentry *mntroot = ERR_PTR(-ENOMEM);
	112
fbdefd64 BS	113	mount_info->set_security = nfs_set_sb_security;
	114
	115	/* Get a volume representation */
1179acc6	116	server = nfs4_create_server(mount_info, &nfs_v4);
fbdefd64 BS	117	if (IS_ERR(server)) {
	118	mntroot = ERR_CAST(server);
	119	goto out;
	120	}
	121
ab7017a3	122	mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);
fbdefd64 BS	123
	124	out:
	125	return mntroot;
	126	}
	127
	128	static struct vfsmount nfs_do_root_mount(struct file_system_type fs_type,
	129	int flags, void data, const char hostname)
	130	{
	131	struct vfsmount *root_mnt;
	132	char *root_devname;
	133	size_t len;
	134
	135	len = strlen(hostname) + 5;
	136	root_devname = kmalloc(len, GFP_KERNEL);
	137	if (root_devname == NULL)
	138	return ERR_PTR(-ENOMEM);
	139	/* Does hostname needs to be enclosed in brackets? */
	140	if (strchr(hostname, ':'))
	141	snprintf(root_devname, len, "[%s]:/", hostname);
	142	else
	143	snprintf(root_devname, len, "%s:/", hostname);
	144	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
	145	kfree(root_devname);
	146	return root_mnt;
	147	}
	148
	149	struct nfs_referral_count {
	150	struct list_head list;
	151	const struct task_struct *task;
	152	unsigned int referral_count;
	153	};
	154
	155	static LIST_HEAD(nfs_referral_count_list);
	156	static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
	157
	158	static struct nfs_referral_count *nfs_find_referral_count(void)
	159	{
	160	struct nfs_referral_count *p;
	161
	162	list_for_each_entry(p, &nfs_referral_count_list, list) {
	163	if (p->task == current)
	164	return p;
	165	}
	166	return NULL;
	167	}
	168
	169	#define NFS_MAX_NESTED_REFERRALS 2
	170
	171	static int nfs_referral_loop_protect(void)
	172	{
	173	struct nfs_referral_count p, new;
	174	int ret = -ENOMEM;
	175
	176	new = kmalloc(sizeof(*new), GFP_KERNEL);
	177	if (!new)
	178	goto out;
	179	new->task = current;
	180	new->referral_count = 1;
	181
	182	ret = 0;
	183	spin_lock(&nfs_referral_count_list_lock);
	184	p = nfs_find_referral_count();
	185	if (p != NULL) {
	186	if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
187	ret = -ELOOP;
188	else
189	p->referral_count++;
190	} else {
191	list_add(&new->list, &nfs_referral_count_list);
192	new = NULL;
193	}
194	spin_unlock(&nfs_referral_count_list_lock);
195	kfree(new);
196	out:
197	return ret;
198	}
199
200	static void nfs_referral_loop_unprotect(void)
201	{
202	struct nfs_referral_count *p;
203
204	spin_lock(&nfs_referral_count_list_lock);
205	p = nfs_find_referral_count();
206	p->referral_count--;
207	if (p->referral_count == 0)
208	list_del(&p->list);
209	else
210	p = NULL;
211	spin_unlock(&nfs_referral_count_list_lock);
212	kfree(p);
213	}
214
215	static struct dentry nfs_follow_remote_path(struct vfsmount root_mnt,
216	const char *export_path)
217	{
218	struct dentry *dentry;
219	int err;
220
221	if (IS_ERR(root_mnt))
222	return ERR_CAST(root_mnt);
223
224	err = nfs_referral_loop_protect();
225	if (err) {
226	mntput(root_mnt);
227	return ERR_PTR(err);
228	}
229
230	dentry = mount_subtree(root_mnt, export_path);
231	nfs_referral_loop_unprotect();
232
233	return dentry;
234	}
235
236	struct dentry nfs4_try_mount(int flags, const char dev_name,
ff9099f2 BS	237	struct nfs_mount_info *mount_info,
ff9099f2 BS	238	struct nfs_subversion *nfs_mod)
fbdefd64 BS	239	{
	240	char *export_path;
	241	struct vfsmount *root_mnt;
	242	struct dentry *res;
	243	struct nfs_parsed_mount_data *data = mount_info->parsed;
	244
	245	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
	246
fbdefd64 BS	247	export_path = data->nfs_server.export_path;
	248	data->nfs_server.export_path = "/";
	249	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
	250	data->nfs_server.hostname);
	251	data->nfs_server.export_path = export_path;
	252
	253	res = nfs_follow_remote_path(root_mnt, export_path);
	254
6706246b GB	255	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
	256	PTR_ERR_OR_ZERO(res),
	257	IS_ERR(res) ? " [error]" : "");
fbdefd64 BS	258	return res;
	259	}
	260
fbdefd64 BS	261	static struct dentry *
	262	nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
	263	const char dev_name, void raw_data)
	264	{
	265	struct nfs_mount_info mount_info = {
6a74490d	266	.fill_super = nfs_fill_super,
fbdefd64 BS	267	.set_security = nfs_clone_sb_security,
	268	.cloned = raw_data,
	269	};
	270	struct nfs_server *server;
	271	struct dentry *mntroot = ERR_PTR(-ENOMEM);
	272
	273	dprintk("--> nfs4_referral_get_sb()\n");
	274
	275	mount_info.mntfh = nfs_alloc_fhandle();
	276	if (mount_info.cloned == NULL \|\| mount_info.mntfh == NULL)
	277	goto out;
	278
	279	/* create a new volume representation */
	280	server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
	281	if (IS_ERR(server)) {
	282	mntroot = ERR_CAST(server);
	283	goto out;
	284	}
	285
ab7017a3	286	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
fbdefd64 BS	287	out:
	288	nfs_free_fhandle(mount_info.mntfh);
	289	return mntroot;
	290	}
	291
	292	/*
	293	* Create an NFS4 server record on referral traversal
	294	*/
	295	static struct dentry nfs4_referral_mount(struct file_system_type fs_type,
	296	int flags, const char dev_name, void raw_data)
	297	{
	298	struct nfs_clone_mount *data = raw_data;
	299	char *export_path;
	300	struct vfsmount *root_mnt;
	301	struct dentry *res;
	302
	303	dprintk("--> nfs4_referral_mount()\n");
	304
	305	export_path = data->mnt_path;
	306	data->mnt_path = "/";
	307
	308	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
	309	flags, data, data->hostname);
	310	data->mnt_path = export_path;
	311
	312	res = nfs_follow_remote_path(root_mnt, export_path);
6706246b GB	313	dprintk("<-- nfs4_referral_mount() = %d%s\n",
	314	PTR_ERR_OR_ZERO(res),
	315	IS_ERR(res) ? " [error]" : "");
fbdefd64 BS	316	return res;
	317	}
	318
	319
89d77c8f	320	static int __init init_nfs_v4(void)
129d1977 BS	321	{
	322	int err;
	323
c8d74d9b	324	err = nfs_dns_resolver_init();
129d1977 BS	325	if (err)
	326	goto out;
	327
c8d74d9b	328	err = nfs_idmap_init();
466bfe7f BS	329	if (err)
	330	goto out1;
	331
c8d74d9b TM	332	err = nfs4_register_sysctl();
	333	if (err)
	334	goto out2;
	335
ab7017a3	336	register_nfs_version(&nfs_v4);
129d1977	337	return 0;
c8d74d9b	338	out2:
466bfe7f	339	nfs_idmap_quit();
c8d74d9b TM	340	out1:
c8d74d9b TM	341	nfs_dns_resolver_destroy();
129d1977 BS	342	out:
	343	return err;
	344	}
	345
89d77c8f	346	static void __exit exit_nfs_v4(void)
129d1977	347	{
5f01d953 PT	348	/* Not called in the _init(), conditionally loaded */
	349	nfs4_pnfs_v3_ds_connect_unload();
	350
ab7017a3	351	unregister_nfs_version(&nfs_v4);
466bfe7f	352	nfs4_unregister_sysctl();
129d1977	353	nfs_idmap_quit();
c8d74d9b	354	nfs_dns_resolver_destroy();
129d1977	355	}
89d77c8f BS	356
	357	MODULE_LICENSE("GPL");
	358
	359	module_init(init_nfs_v4);
	360	module_exit(exit_nfs_v4);