Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 2 | /* |
| 3 | * linux/fs/nfs/dns_resolve.c |
| 4 | * |
| 5 | * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com> |
| 6 | * |
| 7 | * Resolves DNS hostnames into valid ip addresses |
| 8 | */ |
| 9 | |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 10 | #ifdef CONFIG_NFS_USE_KERNEL_DNS |
| 11 | |
Bryan Schumaker | 89d77c8 | 2012-07-30 16:05:25 -0400 | [diff] [blame] | 12 | #include <linux/module.h> |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 13 | #include <linux/sunrpc/clnt.h> |
Jeff Layton | 5976687 | 2013-02-04 12:50:00 -0500 | [diff] [blame] | 14 | #include <linux/sunrpc/addr.h> |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 15 | #include <linux/dns_resolver.h> |
Trond Myklebust | 1728017 | 2012-03-11 13:11:00 -0400 | [diff] [blame] | 16 | #include "dns_resolve.h" |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 17 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 18 | ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen, |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 19 | struct sockaddr *sa, size_t salen) |
| 20 | { |
| 21 | ssize_t ret; |
| 22 | char *ip_addr = NULL; |
| 23 | int ip_len; |
| 24 | |
| 25 | ip_len = dns_query(NULL, name, namelen, NULL, &ip_addr, NULL); |
| 26 | if (ip_len > 0) |
Stanislav Kinsbursky | bc224f5 | 2012-01-26 15:11:33 +0400 | [diff] [blame] | 27 | ret = rpc_pton(net, ip_addr, ip_len, sa, salen); |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 28 | else |
| 29 | ret = -ESRCH; |
| 30 | kfree(ip_addr); |
| 31 | return ret; |
| 32 | } |
| 33 | |
| 34 | #else |
| 35 | |
Bryan Schumaker | 89d77c8 | 2012-07-30 16:05:25 -0400 | [diff] [blame] | 36 | #include <linux/module.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 37 | #include <linux/hash.h> |
| 38 | #include <linux/string.h> |
| 39 | #include <linux/kmod.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 40 | #include <linux/slab.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 41 | #include <linux/module.h> |
| 42 | #include <linux/socket.h> |
| 43 | #include <linux/seq_file.h> |
| 44 | #include <linux/inet.h> |
| 45 | #include <linux/sunrpc/clnt.h> |
Jeff Layton | 5976687 | 2013-02-04 12:50:00 -0500 | [diff] [blame] | 46 | #include <linux/sunrpc/addr.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 47 | #include <linux/sunrpc/cache.h> |
| 48 | #include <linux/sunrpc/svcauth.h> |
Stanislav Kinsbursky | 9df69c8 | 2011-11-25 17:13:12 +0300 | [diff] [blame] | 49 | #include <linux/sunrpc/rpc_pipe_fs.h> |
Anna Schumaker | 694e096 | 2013-11-13 12:29:08 -0500 | [diff] [blame] | 50 | #include <linux/nfs_fs.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 51 | |
Anna Schumaker | 694e096 | 2013-11-13 12:29:08 -0500 | [diff] [blame] | 52 | #include "nfs4_fs.h" |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 53 | #include "dns_resolve.h" |
| 54 | #include "cache_lib.h" |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 55 | #include "netns.h" |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 56 | |
| 57 | #define NFS_DNS_HASHBITS 4 |
| 58 | #define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS) |
| 59 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 60 | struct nfs_dns_ent { |
| 61 | struct cache_head h; |
| 62 | |
| 63 | char *hostname; |
| 64 | size_t namelen; |
| 65 | |
| 66 | struct sockaddr_storage addr; |
| 67 | size_t addrlen; |
| 68 | }; |
| 69 | |
| 70 | |
Trond Myklebust | ebed920 | 2010-03-02 13:06:22 -0500 | [diff] [blame] | 71 | static void nfs_dns_ent_update(struct cache_head *cnew, |
| 72 | struct cache_head *ckey) |
| 73 | { |
| 74 | struct nfs_dns_ent *new; |
| 75 | struct nfs_dns_ent *key; |
| 76 | |
| 77 | new = container_of(cnew, struct nfs_dns_ent, h); |
| 78 | key = container_of(ckey, struct nfs_dns_ent, h); |
| 79 | |
| 80 | memcpy(&new->addr, &key->addr, key->addrlen); |
| 81 | new->addrlen = key->addrlen; |
| 82 | } |
| 83 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 84 | static void nfs_dns_ent_init(struct cache_head *cnew, |
| 85 | struct cache_head *ckey) |
| 86 | { |
| 87 | struct nfs_dns_ent *new; |
| 88 | struct nfs_dns_ent *key; |
| 89 | |
| 90 | new = container_of(cnew, struct nfs_dns_ent, h); |
| 91 | key = container_of(ckey, struct nfs_dns_ent, h); |
| 92 | |
| 93 | kfree(new->hostname); |
| 94 | new->hostname = kstrndup(key->hostname, key->namelen, GFP_KERNEL); |
| 95 | if (new->hostname) { |
| 96 | new->namelen = key->namelen; |
Trond Myklebust | ebed920 | 2010-03-02 13:06:22 -0500 | [diff] [blame] | 97 | nfs_dns_ent_update(cnew, ckey); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 98 | } else { |
| 99 | new->namelen = 0; |
| 100 | new->addrlen = 0; |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | static void nfs_dns_ent_put(struct kref *ref) |
| 105 | { |
| 106 | struct nfs_dns_ent *item; |
| 107 | |
| 108 | item = container_of(ref, struct nfs_dns_ent, h.ref); |
| 109 | kfree(item->hostname); |
| 110 | kfree(item); |
| 111 | } |
| 112 | |
| 113 | static struct cache_head *nfs_dns_ent_alloc(void) |
| 114 | { |
| 115 | struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL); |
| 116 | |
| 117 | if (item != NULL) { |
| 118 | item->hostname = NULL; |
| 119 | item->namelen = 0; |
| 120 | item->addrlen = 0; |
| 121 | return &item->h; |
| 122 | } |
| 123 | return NULL; |
| 124 | }; |
| 125 | |
| 126 | static unsigned int nfs_dns_hash(const struct nfs_dns_ent *key) |
| 127 | { |
| 128 | return hash_str(key->hostname, NFS_DNS_HASHBITS); |
| 129 | } |
| 130 | |
| 131 | static void nfs_dns_request(struct cache_detail *cd, |
| 132 | struct cache_head *ch, |
| 133 | char **bpp, int *blen) |
| 134 | { |
| 135 | struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h); |
| 136 | |
| 137 | qword_add(bpp, blen, key->hostname); |
| 138 | (*bpp)[-1] = '\n'; |
| 139 | } |
| 140 | |
| 141 | static int nfs_dns_upcall(struct cache_detail *cd, |
| 142 | struct cache_head *ch) |
| 143 | { |
| 144 | struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h); |
| 145 | int ret; |
| 146 | |
| 147 | ret = nfs_cache_upcall(cd, key->hostname); |
| 148 | if (ret) |
Stanislav Kinsbursky | 21cd125 | 2013-02-04 14:02:55 +0300 | [diff] [blame] | 149 | ret = sunrpc_cache_pipe_upcall(cd, ch); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 150 | return ret; |
| 151 | } |
| 152 | |
| 153 | static int nfs_dns_match(struct cache_head *ca, |
| 154 | struct cache_head *cb) |
| 155 | { |
| 156 | struct nfs_dns_ent *a; |
| 157 | struct nfs_dns_ent *b; |
| 158 | |
| 159 | a = container_of(ca, struct nfs_dns_ent, h); |
| 160 | b = container_of(cb, struct nfs_dns_ent, h); |
| 161 | |
| 162 | if (a->namelen == 0 || a->namelen != b->namelen) |
| 163 | return 0; |
| 164 | return memcmp(a->hostname, b->hostname, a->namelen) == 0; |
| 165 | } |
| 166 | |
| 167 | static int nfs_dns_show(struct seq_file *m, struct cache_detail *cd, |
| 168 | struct cache_head *h) |
| 169 | { |
| 170 | struct nfs_dns_ent *item; |
| 171 | long ttl; |
| 172 | |
| 173 | if (h == NULL) { |
| 174 | seq_puts(m, "# ip address hostname ttl\n"); |
| 175 | return 0; |
| 176 | } |
| 177 | item = container_of(h, struct nfs_dns_ent, h); |
NeilBrown | c5b29f8 | 2010-08-12 16:55:22 +1000 | [diff] [blame] | 178 | ttl = item->h.expiry_time - seconds_since_boot(); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 179 | if (ttl < 0) |
| 180 | ttl = 0; |
| 181 | |
| 182 | if (!test_bit(CACHE_NEGATIVE, &h->flags)) { |
| 183 | char buf[INET6_ADDRSTRLEN+IPV6_SCOPE_ID_LEN+1]; |
| 184 | |
| 185 | rpc_ntop((struct sockaddr *)&item->addr, buf, sizeof(buf)); |
| 186 | seq_printf(m, "%15s ", buf); |
| 187 | } else |
| 188 | seq_puts(m, "<none> "); |
| 189 | seq_printf(m, "%15s %ld\n", item->hostname, ttl); |
| 190 | return 0; |
| 191 | } |
| 192 | |
Trond Myklebust | 0a6566e | 2009-12-03 15:54:01 -0500 | [diff] [blame] | 193 | static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 194 | struct nfs_dns_ent *key) |
| 195 | { |
| 196 | struct cache_head *ch; |
| 197 | |
| 198 | ch = sunrpc_cache_lookup(cd, |
| 199 | &key->h, |
| 200 | nfs_dns_hash(key)); |
| 201 | if (!ch) |
| 202 | return NULL; |
| 203 | return container_of(ch, struct nfs_dns_ent, h); |
| 204 | } |
| 205 | |
Trond Myklebust | 0a6566e | 2009-12-03 15:54:01 -0500 | [diff] [blame] | 206 | static struct nfs_dns_ent *nfs_dns_update(struct cache_detail *cd, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 207 | struct nfs_dns_ent *new, |
| 208 | struct nfs_dns_ent *key) |
| 209 | { |
| 210 | struct cache_head *ch; |
| 211 | |
| 212 | ch = sunrpc_cache_update(cd, |
| 213 | &new->h, &key->h, |
| 214 | nfs_dns_hash(key)); |
| 215 | if (!ch) |
| 216 | return NULL; |
| 217 | return container_of(ch, struct nfs_dns_ent, h); |
| 218 | } |
| 219 | |
| 220 | static int nfs_dns_parse(struct cache_detail *cd, char *buf, int buflen) |
| 221 | { |
| 222 | char buf1[NFS_DNS_HOSTNAME_MAXLEN+1]; |
| 223 | struct nfs_dns_ent key, *item; |
NeilBrown | 8d96b10 | 2012-10-31 12:16:01 +1100 | [diff] [blame] | 224 | unsigned int ttl; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 225 | ssize_t len; |
| 226 | int ret = -EINVAL; |
| 227 | |
| 228 | if (buf[buflen-1] != '\n') |
| 229 | goto out; |
| 230 | buf[buflen-1] = '\0'; |
| 231 | |
| 232 | len = qword_get(&buf, buf1, sizeof(buf1)); |
| 233 | if (len <= 0) |
| 234 | goto out; |
Stanislav Kinsbursky | 599ec12 | 2012-01-19 18:51:04 +0400 | [diff] [blame] | 235 | key.addrlen = rpc_pton(cd->net, buf1, len, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 236 | (struct sockaddr *)&key.addr, |
| 237 | sizeof(key.addr)); |
| 238 | |
| 239 | len = qword_get(&buf, buf1, sizeof(buf1)); |
| 240 | if (len <= 0) |
| 241 | goto out; |
| 242 | |
| 243 | key.hostname = buf1; |
| 244 | key.namelen = len; |
| 245 | memset(&key.h, 0, sizeof(key.h)); |
| 246 | |
NeilBrown | 8d96b10 | 2012-10-31 12:16:01 +1100 | [diff] [blame] | 247 | if (get_uint(&buf, &ttl) < 0) |
| 248 | goto out; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 249 | if (ttl == 0) |
| 250 | goto out; |
NeilBrown | c5b29f8 | 2010-08-12 16:55:22 +1000 | [diff] [blame] | 251 | key.h.expiry_time = ttl + seconds_since_boot(); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 252 | |
| 253 | ret = -ENOMEM; |
| 254 | item = nfs_dns_lookup(cd, &key); |
| 255 | if (item == NULL) |
| 256 | goto out; |
| 257 | |
| 258 | if (key.addrlen == 0) |
| 259 | set_bit(CACHE_NEGATIVE, &key.h.flags); |
| 260 | |
| 261 | item = nfs_dns_update(cd, &key, item); |
| 262 | if (item == NULL) |
| 263 | goto out; |
| 264 | |
| 265 | ret = 0; |
| 266 | cache_put(&item->h, cd); |
| 267 | out: |
| 268 | return ret; |
| 269 | } |
| 270 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 271 | static int do_cache_lookup(struct cache_detail *cd, |
| 272 | struct nfs_dns_ent *key, |
| 273 | struct nfs_dns_ent **item, |
| 274 | struct nfs_cache_defer_req *dreq) |
| 275 | { |
| 276 | int ret = -ENOMEM; |
| 277 | |
| 278 | *item = nfs_dns_lookup(cd, key); |
| 279 | if (*item) { |
| 280 | ret = cache_check(cd, &(*item)->h, &dreq->req); |
| 281 | if (ret) |
| 282 | *item = NULL; |
| 283 | } |
| 284 | return ret; |
| 285 | } |
| 286 | |
| 287 | static int do_cache_lookup_nowait(struct cache_detail *cd, |
| 288 | struct nfs_dns_ent *key, |
| 289 | struct nfs_dns_ent **item) |
| 290 | { |
| 291 | int ret = -ENOMEM; |
| 292 | |
| 293 | *item = nfs_dns_lookup(cd, key); |
| 294 | if (!*item) |
| 295 | goto out_err; |
| 296 | ret = -ETIMEDOUT; |
| 297 | if (!test_bit(CACHE_VALID, &(*item)->h.flags) |
NeilBrown | c5b29f8 | 2010-08-12 16:55:22 +1000 | [diff] [blame] | 298 | || (*item)->h.expiry_time < seconds_since_boot() |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 299 | || cd->flush_time > (*item)->h.last_refresh) |
| 300 | goto out_put; |
| 301 | ret = -ENOENT; |
| 302 | if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags)) |
| 303 | goto out_put; |
| 304 | return 0; |
| 305 | out_put: |
| 306 | cache_put(&(*item)->h, cd); |
| 307 | out_err: |
| 308 | *item = NULL; |
| 309 | return ret; |
| 310 | } |
| 311 | |
| 312 | static int do_cache_lookup_wait(struct cache_detail *cd, |
| 313 | struct nfs_dns_ent *key, |
| 314 | struct nfs_dns_ent **item) |
| 315 | { |
| 316 | struct nfs_cache_defer_req *dreq; |
| 317 | int ret = -ENOMEM; |
| 318 | |
| 319 | dreq = nfs_cache_defer_req_alloc(); |
| 320 | if (!dreq) |
| 321 | goto out; |
| 322 | ret = do_cache_lookup(cd, key, item, dreq); |
| 323 | if (ret == -EAGAIN) { |
| 324 | ret = nfs_cache_wait_for_upcall(dreq); |
| 325 | if (!ret) |
| 326 | ret = do_cache_lookup_nowait(cd, key, item); |
| 327 | } |
| 328 | nfs_cache_defer_req_put(dreq); |
| 329 | out: |
| 330 | return ret; |
| 331 | } |
| 332 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 333 | ssize_t nfs_dns_resolve_name(struct net *net, char *name, |
| 334 | size_t namelen, struct sockaddr *sa, size_t salen) |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 335 | { |
| 336 | struct nfs_dns_ent key = { |
| 337 | .hostname = name, |
| 338 | .namelen = namelen, |
| 339 | }; |
| 340 | struct nfs_dns_ent *item = NULL; |
| 341 | ssize_t ret; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 342 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 343 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 344 | ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 345 | if (ret == 0) { |
| 346 | if (salen >= item->addrlen) { |
| 347 | memcpy(sa, &item->addr, item->addrlen); |
| 348 | ret = item->addrlen; |
| 349 | } else |
| 350 | ret = -EOVERFLOW; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 351 | cache_put(&item->h, nn->nfs_dns_resolve); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 352 | } else if (ret == -ENOENT) |
| 353 | ret = -ESRCH; |
| 354 | return ret; |
| 355 | } |
| 356 | |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 357 | static struct cache_detail nfs_dns_resolve_template = { |
| 358 | .owner = THIS_MODULE, |
| 359 | .hash_size = NFS_DNS_HASHTBL_SIZE, |
| 360 | .name = "dns_resolve", |
| 361 | .cache_put = nfs_dns_ent_put, |
| 362 | .cache_upcall = nfs_dns_upcall, |
Stanislav Kinsbursky | 73fb847 | 2013-02-04 14:02:45 +0300 | [diff] [blame] | 363 | .cache_request = nfs_dns_request, |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 364 | .cache_parse = nfs_dns_parse, |
| 365 | .cache_show = nfs_dns_show, |
| 366 | .match = nfs_dns_match, |
| 367 | .init = nfs_dns_ent_init, |
| 368 | .update = nfs_dns_ent_update, |
| 369 | .alloc = nfs_dns_ent_alloc, |
| 370 | }; |
| 371 | |
| 372 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 373 | int nfs_dns_resolver_cache_init(struct net *net) |
| 374 | { |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 375 | int err; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 376 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 377 | |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 378 | nn->nfs_dns_resolve = cache_create_net(&nfs_dns_resolve_template, net); |
| 379 | if (IS_ERR(nn->nfs_dns_resolve)) |
| 380 | return PTR_ERR(nn->nfs_dns_resolve); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 381 | |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 382 | err = nfs_cache_register_net(net, nn->nfs_dns_resolve); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 383 | if (err) |
| 384 | goto err_reg; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 385 | return 0; |
| 386 | |
| 387 | err_reg: |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 388 | cache_destroy_net(nn->nfs_dns_resolve, net); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 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); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 395 | |
Stanislav Kinsbursky | 462b8f6 | 2013-02-04 14:02:40 +0300 | [diff] [blame] | 396 | nfs_cache_unregister_net(net, nn->nfs_dns_resolve); |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 397 | cache_destroy_net(nn->nfs_dns_resolve, net); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 398 | } |
| 399 | |
Trond Myklebust | c8d74d9 | 2013-06-01 11:50:58 -0400 | [diff] [blame] | 400 | static int nfs4_dns_net_init(struct net *net) |
| 401 | { |
| 402 | return nfs_dns_resolver_cache_init(net); |
| 403 | } |
| 404 | |
| 405 | static void nfs4_dns_net_exit(struct net *net) |
| 406 | { |
| 407 | nfs_dns_resolver_cache_destroy(net); |
| 408 | } |
| 409 | |
| 410 | static struct pernet_operations nfs4_dns_resolver_ops = { |
| 411 | .init = nfs4_dns_net_init, |
| 412 | .exit = nfs4_dns_net_exit, |
| 413 | }; |
| 414 | |
Stanislav Kinsbursky | 9df69c8 | 2011-11-25 17:13:12 +0300 | [diff] [blame] | 415 | static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, |
| 416 | void *ptr) |
| 417 | { |
| 418 | struct super_block *sb = ptr; |
| 419 | struct net *net = sb->s_fs_info; |
| 420 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
| 421 | struct cache_detail *cd = nn->nfs_dns_resolve; |
| 422 | int ret = 0; |
| 423 | |
| 424 | if (cd == NULL) |
| 425 | return 0; |
| 426 | |
| 427 | if (!try_module_get(THIS_MODULE)) |
| 428 | return 0; |
| 429 | |
| 430 | switch (event) { |
| 431 | case RPC_PIPEFS_MOUNT: |
| 432 | ret = nfs_cache_register_sb(sb, cd); |
| 433 | break; |
| 434 | case RPC_PIPEFS_UMOUNT: |
| 435 | nfs_cache_unregister_sb(sb, cd); |
| 436 | break; |
| 437 | default: |
| 438 | ret = -ENOTSUPP; |
| 439 | break; |
| 440 | } |
| 441 | module_put(THIS_MODULE); |
| 442 | return ret; |
| 443 | } |
| 444 | |
| 445 | static struct notifier_block nfs_dns_resolver_block = { |
| 446 | .notifier_call = rpc_pipefs_event, |
| 447 | }; |
| 448 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 449 | int nfs_dns_resolver_init(void) |
| 450 | { |
Trond Myklebust | c8d74d9 | 2013-06-01 11:50:58 -0400 | [diff] [blame] | 451 | int err; |
| 452 | |
| 453 | err = register_pernet_subsys(&nfs4_dns_resolver_ops); |
| 454 | if (err < 0) |
| 455 | goto out; |
| 456 | err = rpc_pipefs_notifier_register(&nfs_dns_resolver_block); |
| 457 | if (err < 0) |
| 458 | goto out1; |
| 459 | return 0; |
| 460 | out1: |
| 461 | unregister_pernet_subsys(&nfs4_dns_resolver_ops); |
| 462 | out: |
| 463 | return err; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 464 | } |
| 465 | |
| 466 | void nfs_dns_resolver_destroy(void) |
| 467 | { |
Stanislav Kinsbursky | 9df69c8 | 2011-11-25 17:13:12 +0300 | [diff] [blame] | 468 | rpc_pipefs_notifier_unregister(&nfs_dns_resolver_block); |
Trond Myklebust | c8d74d9 | 2013-06-01 11:50:58 -0400 | [diff] [blame] | 469 | unregister_pernet_subsys(&nfs4_dns_resolver_ops); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 470 | } |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 471 | #endif |