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

/*
 * linux/fs/nfs/dns_resolve.c
 *
 * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
 *
 * Resolves DNS hostnames into valid ip addresses
 */

#ifdef CONFIG_NFS_USE_KERNEL_DNS

#include <linux/sunrpc/clnt.h>
#include <linux/dns_resolver.h>

ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen,
		struct sockaddr *sa, size_t salen)
{
	ssize_t ret;
	char *ip_addr = NULL;
	int ip_len;

	ip_len = dns_query(NULL, name, namelen, NULL, &ip_addr, NULL);
	if (ip_len > 0)
		ret = rpc_pton(ip_addr, ip_len, sa, salen);
	else
		ret = -ESRCH;
	kfree(ip_addr);
	return ret;
}

#else

#include <linux/hash.h>
#include <linux/string.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/seq_file.h>
#include <linux/inet.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/cache.h>
#include <linux/sunrpc/svcauth.h>

#include "dns_resolve.h"
#include "cache_lib.h"
#include "netns.h"

#define NFS_DNS_HASHBITS 4
#define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS)

struct nfs_dns_ent {
	struct cache_head h;

	char *hostname;
	size_t namelen;

	struct sockaddr_storage addr;
	size_t addrlen;
};


static void nfs_dns_ent_update(struct cache_head *cnew,
		struct cache_head *ckey)
{
	struct nfs_dns_ent *new;
	struct nfs_dns_ent *key;

	new = container_of(cnew, struct nfs_dns_ent, h);
	key = container_of(ckey, struct nfs_dns_ent, h);

	memcpy(&new->addr, &key->addr, key->addrlen);
	new->addrlen = key->addrlen;
}

static void nfs_dns_ent_init(struct cache_head *cnew,
		struct cache_head *ckey)
{
	struct nfs_dns_ent *new;
	struct nfs_dns_ent *key;

	new = container_of(cnew, struct nfs_dns_ent, h);
	key = container_of(ckey, struct nfs_dns_ent, h);

	kfree(new->hostname);
	new->hostname = kstrndup(key->hostname, key->namelen, GFP_KERNEL);
	if (new->hostname) {
		new->namelen = key->namelen;
		nfs_dns_ent_update(cnew, ckey);
	} else {
		new->namelen = 0;
		new->addrlen = 0;
	}
}

static void nfs_dns_ent_put(struct kref *ref)
{
	struct nfs_dns_ent *item;

	item = container_of(ref, struct nfs_dns_ent, h.ref);
	kfree(item->hostname);
	kfree(item);
}

static struct cache_head *nfs_dns_ent_alloc(void)
{
	struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL);

	if (item != NULL) {
		item->hostname = NULL;
		item->namelen = 0;
		item->addrlen = 0;
		return &item->h;
	}
	return NULL;
};

static unsigned int nfs_dns_hash(const struct nfs_dns_ent *key)
{
	return hash_str(key->hostname, NFS_DNS_HASHBITS);
}

static void nfs_dns_request(struct cache_detail *cd,
		struct cache_head *ch,
		char **bpp, int *blen)
{
	struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h);

	qword_add(bpp, blen, key->hostname);
	(*bpp)[-1] = '\n';
}

static int nfs_dns_upcall(struct cache_detail *cd,
		struct cache_head *ch)
{
	struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h);
	int ret;

	ret = nfs_cache_upcall(cd, key->hostname);
	if (ret)
		ret = sunrpc_cache_pipe_upcall(cd, ch, nfs_dns_request);
	return ret;
}

static int nfs_dns_match(struct cache_head *ca,
		struct cache_head *cb)
{
	struct nfs_dns_ent *a;
	struct nfs_dns_ent *b;

	a = container_of(ca, struct nfs_dns_ent, h);
	b = container_of(cb, struct nfs_dns_ent, h);

	if (a->namelen == 0 || a->namelen != b->namelen)
		return 0;
	return memcmp(a->hostname, b->hostname, a->namelen) == 0;
}

static int nfs_dns_show(struct seq_file *m, struct cache_detail *cd,
		struct cache_head *h)
{
	struct nfs_dns_ent *item;
	long ttl;

	if (h == NULL) {
		seq_puts(m, "# ip address      hostname        ttl\n");
		return 0;
	}
	item = container_of(h, struct nfs_dns_ent, h);
	ttl = item->h.expiry_time - seconds_since_boot();
	if (ttl < 0)
		ttl = 0;

	if (!test_bit(CACHE_NEGATIVE, &h->flags)) {
		char buf[INET6_ADDRSTRLEN+IPV6_SCOPE_ID_LEN+1];

		rpc_ntop((struct sockaddr *)&item->addr, buf, sizeof(buf));
		seq_printf(m, "%15s ", buf);
	} else
		seq_puts(m, "<none>          ");
	seq_printf(m, "%15s %ld\n", item->hostname, ttl);
	return 0;
}

static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd,
		struct nfs_dns_ent *key)
{
	struct cache_head *ch;

	ch = sunrpc_cache_lookup(cd,
			&key->h,
			nfs_dns_hash(key));
	if (!ch)
		return NULL;
	return container_of(ch, struct nfs_dns_ent, h);
}

static struct nfs_dns_ent *nfs_dns_update(struct cache_detail *cd,
		struct nfs_dns_ent *new,
		struct nfs_dns_ent *key)
{
	struct cache_head *ch;

	ch = sunrpc_cache_update(cd,
			&new->h, &key->h,
			nfs_dns_hash(key));
	if (!ch)
		return NULL;
	return container_of(ch, struct nfs_dns_ent, h);
}

static int nfs_dns_parse(struct cache_detail *cd, char *buf, int buflen)
{
	char buf1[NFS_DNS_HOSTNAME_MAXLEN+1];
	struct nfs_dns_ent key, *item;
	unsigned long ttl;
	ssize_t len;
	int ret = -EINVAL;

	if (buf[buflen-1] != '\n')
		goto out;
	buf[buflen-1] = '\0';

	len = qword_get(&buf, buf1, sizeof(buf1));
	if (len <= 0)
		goto out;
	key.addrlen = rpc_pton(buf1, len,
			(struct sockaddr *)&key.addr,
			sizeof(key.addr));

	len = qword_get(&buf, buf1, sizeof(buf1));
	if (len <= 0)
		goto out;

	key.hostname = buf1;
	key.namelen = len;
	memset(&key.h, 0, sizeof(key.h));

	ttl = get_expiry(&buf);
	if (ttl == 0)
		goto out;
	key.h.expiry_time = ttl + seconds_since_boot();

	ret = -ENOMEM;
	item = nfs_dns_lookup(cd, &key);
	if (item == NULL)
		goto out;

	if (key.addrlen == 0)
		set_bit(CACHE_NEGATIVE, &key.h.flags);

	item = nfs_dns_update(cd, &key, item);
	if (item == NULL)
		goto out;

	ret = 0;
	cache_put(&item->h, cd);
out:
	return ret;
}

static int do_cache_lookup(struct cache_detail *cd,
		struct nfs_dns_ent *key,
		struct nfs_dns_ent **item,
		struct nfs_cache_defer_req *dreq)
{
	int ret = -ENOMEM;

	*item = nfs_dns_lookup(cd, key);
	if (*item) {
		ret = cache_check(cd, &(*item)->h, &dreq->req);
		if (ret)
			*item = NULL;
	}
	return ret;
}

static int do_cache_lookup_nowait(struct cache_detail *cd,
		struct nfs_dns_ent *key,
		struct nfs_dns_ent **item)
{
	int ret = -ENOMEM;

	*item = nfs_dns_lookup(cd, key);
	if (!*item)
		goto out_err;
	ret = -ETIMEDOUT;
	if (!test_bit(CACHE_VALID, &(*item)->h.flags)
			|| (*item)->h.expiry_time < seconds_since_boot()
			|| cd->flush_time > (*item)->h.last_refresh)
		goto out_put;
	ret = -ENOENT;
	if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
		goto out_put;
	return 0;
out_put:
	cache_put(&(*item)->h, cd);
out_err:
	*item = NULL;
	return ret;
}

static int do_cache_lookup_wait(struct cache_detail *cd,
		struct nfs_dns_ent *key,
		struct nfs_dns_ent **item)
{
	struct nfs_cache_defer_req *dreq;
	int ret = -ENOMEM;

	dreq = nfs_cache_defer_req_alloc();
	if (!dreq)
		goto out;
	ret = do_cache_lookup(cd, key, item, dreq);
	if (ret == -EAGAIN) {
		ret = nfs_cache_wait_for_upcall(dreq);
		if (!ret)
			ret = do_cache_lookup_nowait(cd, key, item);
	}
	nfs_cache_defer_req_put(dreq);
out:
	return ret;
}

ssize_t nfs_dns_resolve_name(struct net *net, char *name,
		size_t namelen, struct sockaddr *sa, size_t salen)
{
	struct nfs_dns_ent key = {
		.hostname = name,
		.namelen = namelen,
	};
	struct nfs_dns_ent *item = NULL;
	ssize_t ret;
	struct nfs_net *nn = net_generic(net, nfs_net_id);

	ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item);
	if (ret == 0) {
		if (salen >= item->addrlen) {
			memcpy(sa, &item->addr, item->addrlen);
			ret = item->addrlen;
		} else
			ret = -EOVERFLOW;
		cache_put(&item->h, nn->nfs_dns_resolve);
	} else if (ret == -ENOENT)
		ret = -ESRCH;
	return ret;
}

int nfs_dns_resolver_cache_init(struct net *net)
{
	int err = -ENOMEM;
	struct nfs_net *nn = net_generic(net, nfs_net_id);
	struct cache_detail *cd;
	struct cache_head **tbl;

	cd = kzalloc(sizeof(struct cache_detail), GFP_KERNEL);
	if (cd == NULL)
		goto err_cd;

	tbl = kzalloc(NFS_DNS_HASHTBL_SIZE * sizeof(struct cache_head *),
			GFP_KERNEL);
	if (tbl == NULL)
		goto err_tbl;

	cd->owner = THIS_MODULE,
	cd->hash_size = NFS_DNS_HASHTBL_SIZE,
	cd->hash_table = tbl,
	cd->name = "dns_resolve",
	cd->cache_put = nfs_dns_ent_put,
	cd->cache_upcall = nfs_dns_upcall,
	cd->cache_parse = nfs_dns_parse,
	cd->cache_show = nfs_dns_show,
	cd->match = nfs_dns_match,
	cd->init = nfs_dns_ent_init,
	cd->update = nfs_dns_ent_update,
	cd->alloc = nfs_dns_ent_alloc,

	nfs_cache_init(cd);
	err = nfs_cache_register_net(net, cd);
	if (err)
		goto err_reg;
	nn->nfs_dns_resolve = cd;
	return 0;

err_reg:
	nfs_cache_destroy(cd);
	kfree(cd->hash_table);
err_tbl:
	kfree(cd);
err_cd:
	return err;
}

void nfs_dns_resolver_cache_destroy(struct net *net)
{
	struct nfs_net *nn = net_generic(net, nfs_net_id);
	struct cache_detail *cd = nn->nfs_dns_resolve;

	nfs_cache_unregister_net(net, cd);
	nfs_cache_destroy(cd);
	kfree(cd->hash_table);
	kfree(cd);
}

int nfs_dns_resolver_init(void)
{
	return 0;
}

void nfs_dns_resolver_destroy(void)
{
}
#endif
Commit	Line	Data
e571cbf1 TM	1	/*
	2	* linux/fs/nfs/dns_resolve.c
	3	*
	4	* Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
	5	*
	6	* Resolves DNS hostnames into valid ip addresses
	7	*/
	8
c2e8139c BS	9	#ifdef CONFIG_NFS_USE_KERNEL_DNS
	10
	11	#include <linux/sunrpc/clnt.h>
	12	#include <linux/dns_resolver.h>
	13
1b340d01	14	ssize_t nfs_dns_resolve_name(struct net net, char name, size_t namelen,
c2e8139c BS	15	struct sockaddr *sa, size_t salen)
	16	{
	17	ssize_t ret;
	18	char *ip_addr = NULL;
	19	int ip_len;
	20
	21	ip_len = dns_query(NULL, name, namelen, NULL, &ip_addr, NULL);
	22	if (ip_len > 0)
	23	ret = rpc_pton(ip_addr, ip_len, sa, salen);
	24	else
	25	ret = -ESRCH;
	26	kfree(ip_addr);
	27	return ret;
	28	}
	29
	30	#else
	31
e571cbf1 TM	32	#include <linux/hash.h>
	33	#include <linux/string.h>
	34	#include <linux/kmod.h>
5a0e3ad6	35	#include <linux/slab.h>
e571cbf1 TM	36	#include <linux/module.h>
	37	#include <linux/socket.h>
	38	#include <linux/seq_file.h>
	39	#include <linux/inet.h>
	40	#include <linux/sunrpc/clnt.h>
	41	#include <linux/sunrpc/cache.h>
	42	#include <linux/sunrpc/svcauth.h>
	43
	44	#include "dns_resolve.h"
	45	#include "cache_lib.h"
1b340d01	46	#include "netns.h"
e571cbf1 TM	47
	48	#define NFS_DNS_HASHBITS 4
	49	#define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS)
	50
e571cbf1 TM	51	struct nfs_dns_ent {
	52	struct cache_head h;
	53
	54	char *hostname;
	55	size_t namelen;
	56
	57	struct sockaddr_storage addr;
	58	size_t addrlen;
	59	};
	60
	61
ebed9203 TM	62	static void nfs_dns_ent_update(struct cache_head *cnew,
	63	struct cache_head *ckey)
	64	{
	65	struct nfs_dns_ent *new;
	66	struct nfs_dns_ent *key;
	67
	68	new = container_of(cnew, struct nfs_dns_ent, h);
	69	key = container_of(ckey, struct nfs_dns_ent, h);
	70
	71	memcpy(&new->addr, &key->addr, key->addrlen);
	72	new->addrlen = key->addrlen;
	73	}
	74
e571cbf1 TM	75	static void nfs_dns_ent_init(struct cache_head *cnew,
	76	struct cache_head *ckey)
	77	{
	78	struct nfs_dns_ent *new;
	79	struct nfs_dns_ent *key;
	80
	81	new = container_of(cnew, struct nfs_dns_ent, h);
	82	key = container_of(ckey, struct nfs_dns_ent, h);
	83
	84	kfree(new->hostname);
	85	new->hostname = kstrndup(key->hostname, key->namelen, GFP_KERNEL);
	86	if (new->hostname) {
	87	new->namelen = key->namelen;
ebed9203	88	nfs_dns_ent_update(cnew, ckey);
e571cbf1 TM	89	} else {
	90	new->namelen = 0;
	91	new->addrlen = 0;
	92	}
	93	}
	94
	95	static void nfs_dns_ent_put(struct kref *ref)
	96	{
	97	struct nfs_dns_ent *item;
	98
	99	item = container_of(ref, struct nfs_dns_ent, h.ref);
	100	kfree(item->hostname);
	101	kfree(item);
	102	}
	103
	104	static struct cache_head *nfs_dns_ent_alloc(void)
	105	{
	106	struct nfs_dns_ent item = kmalloc(sizeof(item), GFP_KERNEL);
	107
	108	if (item != NULL) {
	109	item->hostname = NULL;
	110	item->namelen = 0;
	111	item->addrlen = 0;
	112	return &item->h;
	113	}
	114	return NULL;
	115	};
	116
	117	static unsigned int nfs_dns_hash(const struct nfs_dns_ent *key)
	118	{
	119	return hash_str(key->hostname, NFS_DNS_HASHBITS);
	120	}
	121
	122	static void nfs_dns_request(struct cache_detail *cd,
	123	struct cache_head *ch,
	124	char *bpp, int blen)
	125	{
	126	struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h);
	127
	128	qword_add(bpp, blen, key->hostname);
	129	(*bpp)[-1] = '\n';
	130	}
	131
	132	static int nfs_dns_upcall(struct cache_detail *cd,
	133	struct cache_head *ch)
	134	{
	135	struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h);
	136	int ret;
	137
	138	ret = nfs_cache_upcall(cd, key->hostname);
	139	if (ret)
	140	ret = sunrpc_cache_pipe_upcall(cd, ch, nfs_dns_request);
	141	return ret;
	142	}
	143
	144	static int nfs_dns_match(struct cache_head *ca,
	145	struct cache_head *cb)
	146	{
	147	struct nfs_dns_ent *a;
	148	struct nfs_dns_ent *b;
	149
	150	a = container_of(ca, struct nfs_dns_ent, h);
	151	b = container_of(cb, struct nfs_dns_ent, h);
	152
153	if (a->namelen == 0 \|\| a->namelen != b->namelen)
154	return 0;
155	return memcmp(a->hostname, b->hostname, a->namelen) == 0;
156	}
157
158	static int nfs_dns_show(struct seq_file m, struct cache_detail cd,
159	struct cache_head *h)
160	{
161	struct nfs_dns_ent *item;
162	long ttl;
163
164	if (h == NULL) {
165	seq_puts(m, "# ip address hostname ttl\n");
166	return 0;
167	}
168	item = container_of(h, struct nfs_dns_ent, h);
c5b29f88	169	ttl = item->h.expiry_time - seconds_since_boot();
e571cbf1 TM	170	if (ttl < 0)
	171	ttl = 0;
	172
	173	if (!test_bit(CACHE_NEGATIVE, &h->flags)) {
	174	char buf[INET6_ADDRSTRLEN+IPV6_SCOPE_ID_LEN+1];
	175
	176	rpc_ntop((struct sockaddr *)&item->addr, buf, sizeof(buf));
	177	seq_printf(m, "%15s ", buf);
	178	} else
	179	seq_puts(m, "<none> ");
	180	seq_printf(m, "%15s %ld\n", item->hostname, ttl);
	181	return 0;
	182	}
	183
0a6566ec	184	static struct nfs_dns_ent nfs_dns_lookup(struct cache_detail cd,
e571cbf1 TM	185	struct nfs_dns_ent *key)
	186	{
	187	struct cache_head *ch;
	188
	189	ch = sunrpc_cache_lookup(cd,
	190	&key->h,
	191	nfs_dns_hash(key));
	192	if (!ch)
	193	return NULL;
	194	return container_of(ch, struct nfs_dns_ent, h);
	195	}
	196
0a6566ec	197	static struct nfs_dns_ent nfs_dns_update(struct cache_detail cd,
e571cbf1 TM	198	struct nfs_dns_ent *new,
	199	struct nfs_dns_ent *key)
	200	{
	201	struct cache_head *ch;
	202
	203	ch = sunrpc_cache_update(cd,
	204	&new->h, &key->h,
	205	nfs_dns_hash(key));
	206	if (!ch)
	207	return NULL;
	208	return container_of(ch, struct nfs_dns_ent, h);
	209	}
	210
	211	static int nfs_dns_parse(struct cache_detail cd, char buf, int buflen)
	212	{
	213	char buf1[NFS_DNS_HOSTNAME_MAXLEN+1];
	214	struct nfs_dns_ent key, *item;
	215	unsigned long ttl;
	216	ssize_t len;
	217	int ret = -EINVAL;
	218
	219	if (buf[buflen-1] != '\n')
	220	goto out;
	221	buf[buflen-1] = '\0';
	222
	223	len = qword_get(&buf, buf1, sizeof(buf1));
	224	if (len <= 0)
	225	goto out;
	226	key.addrlen = rpc_pton(buf1, len,
	227	(struct sockaddr *)&key.addr,
	228	sizeof(key.addr));
	229
	230	len = qword_get(&buf, buf1, sizeof(buf1));
	231	if (len <= 0)
	232	goto out;
	233
	234	key.hostname = buf1;
	235	key.namelen = len;
	236	memset(&key.h, 0, sizeof(key.h));
	237
	238	ttl = get_expiry(&buf);
	239	if (ttl == 0)
	240	goto out;
c5b29f88	241	key.h.expiry_time = ttl + seconds_since_boot();
e571cbf1 TM	242
	243	ret = -ENOMEM;
	244	item = nfs_dns_lookup(cd, &key);
	245	if (item == NULL)
	246	goto out;
	247
	248	if (key.addrlen == 0)
	249	set_bit(CACHE_NEGATIVE, &key.h.flags);
	250
	251	item = nfs_dns_update(cd, &key, item);
	252	if (item == NULL)
	253	goto out;
	254
	255	ret = 0;
	256	cache_put(&item->h, cd);
	257	out:
	258	return ret;
	259	}
	260
e571cbf1 TM	261	static int do_cache_lookup(struct cache_detail *cd,
	262	struct nfs_dns_ent *key,
	263	struct nfs_dns_ent **item,
	264	struct nfs_cache_defer_req *dreq)
	265	{
	266	int ret = -ENOMEM;
	267
	268	*item = nfs_dns_lookup(cd, key);
	269	if (*item) {
	270	ret = cache_check(cd, &(*item)->h, &dreq->req);
	271	if (ret)
	272	*item = NULL;
	273	}
	274	return ret;
	275	}
	276
	277	static int do_cache_lookup_nowait(struct cache_detail *cd,
	278	struct nfs_dns_ent *key,
	279	struct nfs_dns_ent **item)
	280	{
	281	int ret = -ENOMEM;
	282
	283	*item = nfs_dns_lookup(cd, key);
	284	if (!*item)
	285	goto out_err;
	286	ret = -ETIMEDOUT;
	287	if (!test_bit(CACHE_VALID, &(*item)->h.flags)
c5b29f88	288	\|\| (*item)->h.expiry_time < seconds_since_boot()
e571cbf1 TM	289	\|\| cd->flush_time > (*item)->h.last_refresh)
	290	goto out_put;
	291	ret = -ENOENT;
	292	if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
	293	goto out_put;
	294	return 0;
	295	out_put:
	296	cache_put(&(*item)->h, cd);
	297	out_err:
	298	*item = NULL;
	299	return ret;
	300	}
	301
	302	static int do_cache_lookup_wait(struct cache_detail *cd,
	303	struct nfs_dns_ent *key,
	304	struct nfs_dns_ent **item)
	305	{
	306	struct nfs_cache_defer_req *dreq;
	307	int ret = -ENOMEM;
	308
	309	dreq = nfs_cache_defer_req_alloc();
	310	if (!dreq)
	311	goto out;
	312	ret = do_cache_lookup(cd, key, item, dreq);
	313	if (ret == -EAGAIN) {
	314	ret = nfs_cache_wait_for_upcall(dreq);
	315	if (!ret)
	316	ret = do_cache_lookup_nowait(cd, key, item);
	317	}
	318	nfs_cache_defer_req_put(dreq);
	319	out:
	320	return ret;
	321	}
	322
1b340d01 SK	323	ssize_t nfs_dns_resolve_name(struct net net, char name,
1b340d01 SK	324	size_t namelen, struct sockaddr *sa, size_t salen)
e571cbf1 TM	325	{
	326	struct nfs_dns_ent key = {
	327	.hostname = name,
	328	.namelen = namelen,
	329	};
	330	struct nfs_dns_ent *item = NULL;
	331	ssize_t ret;
1b340d01	332	struct nfs_net *nn = net_generic(net, nfs_net_id);
e571cbf1	333
1b340d01	334	ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item);
e571cbf1 TM	335	if (ret == 0) {
	336	if (salen >= item->addrlen) {
	337	memcpy(sa, &item->addr, item->addrlen);
	338	ret = item->addrlen;
	339	} else
	340	ret = -EOVERFLOW;
1b340d01	341	cache_put(&item->h, nn->nfs_dns_resolve);
e571cbf1 TM	342	} else if (ret == -ENOENT)
	343	ret = -ESRCH;
	344	return ret;
	345	}
	346
1b340d01	347	int nfs_dns_resolver_cache_init(struct net *net)
e571cbf1	348	{
1b340d01 SK	349	int err = -ENOMEM;
	350	struct nfs_net *nn = net_generic(net, nfs_net_id);
	351	struct cache_detail *cd;
	352	struct cache_head **tbl;
	353
	354	cd = kzalloc(sizeof(struct cache_detail), GFP_KERNEL);
	355	if (cd == NULL)
	356	goto err_cd;
	357
	358	tbl = kzalloc(NFS_DNS_HASHTBL_SIZE * sizeof(struct cache_head *),
	359	GFP_KERNEL);
	360	if (tbl == NULL)
	361	goto err_tbl;
	362
	363	cd->owner = THIS_MODULE,
	364	cd->hash_size = NFS_DNS_HASHTBL_SIZE,
	365	cd->hash_table = tbl,
	366	cd->name = "dns_resolve",
	367	cd->cache_put = nfs_dns_ent_put,
	368	cd->cache_upcall = nfs_dns_upcall,
	369	cd->cache_parse = nfs_dns_parse,
	370	cd->cache_show = nfs_dns_show,
	371	cd->match = nfs_dns_match,
	372	cd->init = nfs_dns_ent_init,
	373	cd->update = nfs_dns_ent_update,
	374	cd->alloc = nfs_dns_ent_alloc,
	375
	376	nfs_cache_init(cd);
	377	err = nfs_cache_register_net(net, cd);
	378	if (err)
	379	goto err_reg;
	380	nn->nfs_dns_resolve = cd;
	381	return 0;
9222b955	382
1b340d01 SK	383	err_reg:
	384	nfs_cache_destroy(cd);
	385	kfree(cd->hash_table);
	386	err_tbl:
	387	kfree(cd);
	388	err_cd:
	389	return err;
	390	}
	391
	392	void nfs_dns_resolver_cache_destroy(struct net *net)
	393	{
	394	struct nfs_net *nn = net_generic(net, nfs_net_id);
	395	struct cache_detail *cd = nn->nfs_dns_resolve;
	396
	397	nfs_cache_unregister_net(net, cd);
	398	nfs_cache_destroy(cd);
	399	kfree(cd->hash_table);
	400	kfree(cd);
	401	}
	402
	403	int nfs_dns_resolver_init(void)
	404	{
9222b955	405	return 0;
e571cbf1 TM	406	}
	407
	408	void nfs_dns_resolver_destroy(void)
	409	{
e571cbf1	410	}
c2e8139c	411	#endif