fs/nfsd/nfs4idmap.c

   1 /*
   2  *  Mapping of UID/GIDs to name and vice versa.
   3  *
   4  *  Copyright (c) 2002, 2003 The Regents of the University of
   5  *  Michigan.  All rights reserved.
   6  *
   7  *  Marius Aamodt Eriksen <marius@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <linux/module.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/sched.h>
  38 #include <linux/slab.h>
  39 #include <linux/sunrpc/svc_xprt.h>
  40 #include <net/net_namespace.h>
  41 #include "idmap.h"
  42 #include "nfsd.h"
  43 #include "netns.h"
  44
  45 /*
  46  * Turn off idmapping when using AUTH_SYS.
  47  */
  48 static bool nfs4_disable_idmapping = true;
  49 module_param(nfs4_disable_idmapping, bool, 0644);
  50 MODULE_PARM_DESC(nfs4_disable_idmapping,
  51                 "Turn off server's NFSv4 idmapping when using 'sec=sys'");
  52
  53 /*
  54  * Cache entry
  55  */
  56
  57 /*
  58  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  59  * that.
  60  */
  61
  62 struct ent {
  63         struct cache_head h;
  64         int               type;                /* User / Group */
  65         u32               id;
  66         char              name[IDMAP_NAMESZ];
  67         char              authname[IDMAP_NAMESZ];
  68 };
  69
  70 /* Common entry handling */
  71
  72 #define ENT_HASHBITS          8
  73 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  74
  75 static void
  76 ent_init(struct cache_head *cnew, struct cache_head *citm)
  77 {
  78         struct ent *new = container_of(cnew, struct ent, h);
  79         struct ent *itm = container_of(citm, struct ent, h);
  80
  81         new->id = itm->id;
  82         new->type = itm->type;
  83
  84         strlcpy(new->name, itm->name, sizeof(new->name));
  85         strlcpy(new->authname, itm->authname, sizeof(new->name));
  86 }
  87
  88 static void
  89 ent_put(struct kref *ref)
  90 {
  91         struct ent *map = container_of(ref, struct ent, h.ref);
  92         kfree(map);
  93 }
  94
  95 static struct cache_head *
  96 ent_alloc(void)
  97 {
  98         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
  99         if (e)
 100                 return &e->h;
 101         else
 102                 return NULL;
 103 }
 104
 105 /*
 106  * ID -> Name cache
 107  */
 108
 109 static uint32_t
 110 idtoname_hash(struct ent *ent)
 111 {
 112         uint32_t hash;
 113
 114         hash = hash_str(ent->authname, ENT_HASHBITS);
 115         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 116
 117         /* Flip LSB for user/group */
 118         if (ent->type == IDMAP_TYPE_GROUP)
 119                 hash ^= 1;
 120
 121         return hash;
 122 }
 123
 124 static void
 125 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 126     int *blen)
 127 {
 128         struct ent *ent = container_of(ch, struct ent, h);
 129         char idstr[11];
 130
 131         qword_add(bpp, blen, ent->authname);
 132         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 133         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 134         qword_add(bpp, blen, idstr);
 135
 136         (*bpp)[-1] = '\n';
 137 }
 138
 139 static int
 140 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 141 {
 142         struct ent *a = container_of(ca, struct ent, h);
 143         struct ent *b = container_of(cb, struct ent, h);
 144
 145         return (a->id == b->id && a->type == b->type &&
 146             strcmp(a->authname, b->authname) == 0);
 147 }
 148
 149 static int
 150 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 151 {
 152         struct ent *ent;
 153
 154         if (h == NULL) {
 155                 seq_puts(m, "#domain type id [name]\n");
 156                 return 0;
 157         }
 158         ent = container_of(h, struct ent, h);
 159         seq_printf(m, "%s %s %u", ent->authname,
 160                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 161                         ent->id);
 162         if (test_bit(CACHE_VALID, &h->flags))
 163                 seq_printf(m, " %s", ent->name);
 164         seq_printf(m, "\n");
 165         return 0;
 166 }
 167
 168 static void
 169 warn_no_idmapd(struct cache_detail *detail, int has_died)
 170 {
 171         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 172                         has_died ? "died" : "not been started");
 173 }
 174
 175
 176 static int         idtoname_parse(struct cache_detail *, char *, int);
 177 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
 178 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
 179                                    struct ent *);
 180
 181 static struct cache_detail idtoname_cache_template = {
 182         .owner          = THIS_MODULE,
 183         .hash_size      = ENT_HASHMAX,
 184         .name           = "nfs4.idtoname",
 185         .cache_put      = ent_put,
 186         .cache_request  = idtoname_request,
 187         .cache_parse    = idtoname_parse,
 188         .cache_show     = idtoname_show,
 189         .warn_no_listener = warn_no_idmapd,
 190         .match          = idtoname_match,
 191         .init           = ent_init,
 192         .update         = ent_init,
 193         .alloc          = ent_alloc,
 194 };
 195
 196 static int
 197 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 198 {
 199         struct ent ent, *res;
 200         char *buf1, *bp;
 201         int len;
 202         int error = -EINVAL;
 203
 204         if (buf[buflen - 1] != '\n')
 205                 return (-EINVAL);
 206         buf[buflen - 1]= '\0';
 207
 208         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 209         if (buf1 == NULL)
 210                 return (-ENOMEM);
 211
 212         memset(&ent, 0, sizeof(ent));
 213
 214         /* Authentication name */
 215         len = qword_get(&buf, buf1, PAGE_SIZE);
 216         if (len <= 0 || len >= IDMAP_NAMESZ)
 217                 goto out;
 218         memcpy(ent.authname, buf1, sizeof(ent.authname));
 219
 220         /* Type */
 221         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 222                 goto out;
 223         ent.type = strcmp(buf1, "user") == 0 ?
 224                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 225
 226         /* ID */
 227         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 228                 goto out;
 229         ent.id = simple_strtoul(buf1, &bp, 10);
 230         if (bp == buf1)
 231                 goto out;
 232
 233         /* expiry */
 234         ent.h.expiry_time = get_expiry(&buf);
 235         if (ent.h.expiry_time == 0)
 236                 goto out;
 237
 238         error = -ENOMEM;
 239         res = idtoname_lookup(cd, &ent);
 240         if (!res)
 241                 goto out;
 242
 243         /* Name */
 244         error = -EINVAL;
 245         len = qword_get(&buf, buf1, PAGE_SIZE);
 246         if (len < 0 || len >= IDMAP_NAMESZ)
 247                 goto out;
 248         if (len == 0)
 249                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 250         else
 251                 memcpy(ent.name, buf1, sizeof(ent.name));
 252         error = -ENOMEM;
 253         res = idtoname_update(cd, &ent, res);
 254         if (res == NULL)
 255                 goto out;
 256
 257         cache_put(&res->h, cd);
 258         error = 0;
 259 out:
 260         kfree(buf1);
 261         return error;
 262 }
 263
 264 static struct ent *
 265 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 266 {
 267         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 268                                                     idtoname_hash(item));
 269         if (ch)
 270                 return container_of(ch, struct ent, h);
 271         else
 272                 return NULL;
 273 }
 274
 275 static struct ent *
 276 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 277 {
 278         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 279                                                     idtoname_hash(new));
 280         if (ch)
 281                 return container_of(ch, struct ent, h);
 282         else
 283                 return NULL;
 284 }
 285
 286
 287 /*
 288  * Name -> ID cache
 289  */
 290
 291 static inline int
 292 nametoid_hash(struct ent *ent)
 293 {
 294         return hash_str(ent->name, ENT_HASHBITS);
 295 }
 296
 297 static void
 298 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 299     int *blen)
 300 {
 301         struct ent *ent = container_of(ch, struct ent, h);
 302
 303         qword_add(bpp, blen, ent->authname);
 304         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 305         qword_add(bpp, blen, ent->name);
 306
 307         (*bpp)[-1] = '\n';
 308 }
 309
 310 static int
 311 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 312 {
 313         struct ent *a = container_of(ca, struct ent, h);
 314         struct ent *b = container_of(cb, struct ent, h);
 315
 316         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 317             strcmp(a->authname, b->authname) == 0);
 318 }
 319
 320 static int
 321 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 322 {
 323         struct ent *ent;
 324
 325         if (h == NULL) {
 326                 seq_puts(m, "#domain type name [id]\n");
 327                 return 0;
 328         }
 329         ent = container_of(h, struct ent, h);
 330         seq_printf(m, "%s %s %s", ent->authname,
 331                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 332                         ent->name);
 333         if (test_bit(CACHE_VALID, &h->flags))
 334                 seq_printf(m, " %u", ent->id);
 335         seq_printf(m, "\n");
 336         return 0;
 337 }
 338
 339 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
 340 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
 341                                    struct ent *);
 342 static int         nametoid_parse(struct cache_detail *, char *, int);
 343
 344 static struct cache_detail nametoid_cache_template = {
 345         .owner          = THIS_MODULE,
 346         .hash_size      = ENT_HASHMAX,
 347         .name           = "nfs4.nametoid",
 348         .cache_put      = ent_put,
 349         .cache_request  = nametoid_request,
 350         .cache_parse    = nametoid_parse,
 351         .cache_show     = nametoid_show,
 352         .warn_no_listener = warn_no_idmapd,
 353         .match          = nametoid_match,
 354         .init           = ent_init,
 355         .update         = ent_init,
 356         .alloc          = ent_alloc,
 357 };
 358
 359 static int
 360 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 361 {
 362         struct ent ent, *res;
 363         char *buf1;
 364         int len, error = -EINVAL;
 365
 366         if (buf[buflen - 1] != '\n')
 367                 return (-EINVAL);
 368         buf[buflen - 1]= '\0';
 369
 370         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 371         if (buf1 == NULL)
 372                 return (-ENOMEM);
 373
 374         memset(&ent, 0, sizeof(ent));
 375
 376         /* Authentication name */
 377         len = qword_get(&buf, buf1, PAGE_SIZE);
 378         if (len <= 0 || len >= IDMAP_NAMESZ)
 379                 goto out;
 380         memcpy(ent.authname, buf1, sizeof(ent.authname));
 381
 382         /* Type */
 383         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 384                 goto out;
 385         ent.type = strcmp(buf1, "user") == 0 ?
 386                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 387
 388         /* Name */
 389         len = qword_get(&buf, buf1, PAGE_SIZE);
 390         if (len <= 0 || len >= IDMAP_NAMESZ)
 391                 goto out;
 392         memcpy(ent.name, buf1, sizeof(ent.name));
 393
 394         /* expiry */
 395         ent.h.expiry_time = get_expiry(&buf);
 396         if (ent.h.expiry_time == 0)
 397                 goto out;
 398
 399         /* ID */
 400         error = get_int(&buf, &ent.id);
 401         if (error == -EINVAL)
 402                 goto out;
 403         if (error == -ENOENT)
 404                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 405
 406         error = -ENOMEM;
 407         res = nametoid_lookup(cd, &ent);
 408         if (res == NULL)
 409                 goto out;
 410         res = nametoid_update(cd, &ent, res);
 411         if (res == NULL)
 412                 goto out;
 413
 414         cache_put(&res->h, cd);
 415         error = 0;
 416 out:
 417         kfree(buf1);
 418         return (error);
 419 }
 420
 421
 422 static struct ent *
 423 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 424 {
 425         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 426                                                     nametoid_hash(item));
 427         if (ch)
 428                 return container_of(ch, struct ent, h);
 429         else
 430                 return NULL;
 431 }
 432
 433 static struct ent *
 434 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 435 {
 436         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 437                                                     nametoid_hash(new));
 438         if (ch)
 439                 return container_of(ch, struct ent, h);
 440         else
 441                 return NULL;
 442 }
 443
 444 /*
 445  * Exported API
 446  */
 447
 448 int
 449 nfsd_idmap_init(struct net *net)
 450 {
 451         int rv;
 452         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 453
 454         nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
 455         if (IS_ERR(nn->idtoname_cache))
 456                 return PTR_ERR(nn->idtoname_cache);
 457         rv = cache_register_net(nn->idtoname_cache, net);
 458         if (rv)
 459                 goto destroy_idtoname_cache;
 460         nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
 461         if (IS_ERR(nn->nametoid_cache)) {
 462                 rv = PTR_ERR(nn->nametoid_cache);
 463                 goto unregister_idtoname_cache;
 464         }
 465         rv = cache_register_net(nn->nametoid_cache, net);
 466         if (rv)
 467                 goto destroy_nametoid_cache;
 468         return 0;
 469
 470 destroy_nametoid_cache:
 471         cache_destroy_net(nn->nametoid_cache, net);
 472 unregister_idtoname_cache:
 473         cache_unregister_net(nn->idtoname_cache, net);
 474 destroy_idtoname_cache:
 475         cache_destroy_net(nn->idtoname_cache, net);
 476         return rv;
 477 }
 478
 479 void
 480 nfsd_idmap_shutdown(struct net *net)
 481 {
 482         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 483
 484         cache_unregister_net(nn->idtoname_cache, net);
 485         cache_unregister_net(nn->nametoid_cache, net);
 486         cache_destroy_net(nn->idtoname_cache, net);
 487         cache_destroy_net(nn->nametoid_cache, net);
 488 }
 489
 490 static int
 491 idmap_lookup(struct svc_rqst *rqstp,
 492                 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
 493                 struct ent *key, struct cache_detail *detail, struct ent **item)
 494 {
 495         int ret;
 496
 497         *item = lookup_fn(detail, key);
 498         if (!*item)
 499                 return -ENOMEM;
 500  retry:
 501         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 502
 503         if (ret == -ETIMEDOUT) {
 504                 struct ent *prev_item = *item;
 505                 *item = lookup_fn(detail, key);
 506                 if (*item != prev_item)
 507                         goto retry;
 508                 cache_put(&(*item)->h, detail);
 509         }
 510         return ret;
 511 }
 512
 513 static char *
 514 rqst_authname(struct svc_rqst *rqstp)
 515 {
 516         struct auth_domain *clp;
 517
 518         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 519         return clp->name;
 520 }
 521
 522 static __be32
 523 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 524                 u32 *id)
 525 {
 526         struct ent *item, key = {
 527                 .type = type,
 528         };
 529         int ret;
 530         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 531
 532         if (namelen + 1 > sizeof(key.name))
 533                 return nfserr_badowner;
 534         memcpy(key.name, name, namelen);
 535         key.name[namelen] = '\0';
 536         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 537         ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
 538         if (ret == -ENOENT)
 539                 return nfserr_badowner;
 540         if (ret)
 541                 return nfserrno(ret);
 542         *id = item->id;
 543         cache_put(&item->h, nn->nametoid_cache);
 544         return 0;
 545 }
 546
 547 static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
 548 {
 549         char buf[11];
 550         int len;
 551         __be32 *p;
 552
 553         len = sprintf(buf, "%u", id);
 554         p = xdr_reserve_space(xdr, len + 4);
 555         if (!p)
 556                 return nfserr_resource;
 557         p = xdr_encode_opaque(p, buf, len);
 558         return 0;
 559 }
 560
 561 static __be32 idmap_id_to_name(struct xdr_stream *xdr,
 562                                struct svc_rqst *rqstp, int type, u32 id)
 563 {
 564         struct ent *item, key = {
 565                 .id = id,
 566                 .type = type,
 567         };
 568         __be32 *p;
 569         int ret;
 570         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 571
 572         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 573         ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
 574         if (ret == -ENOENT)
 575                 return encode_ascii_id(xdr, id);
 576         if (ret)
 577                 return nfserrno(ret);
 578         ret = strlen(item->name);
 579         WARN_ON_ONCE(ret > IDMAP_NAMESZ);
 580         p = xdr_reserve_space(xdr, ret + 4);
 581         if (!p)
 582                 return nfserr_resource;
 583         p = xdr_encode_opaque(p, item->name, ret);
 584         cache_put(&item->h, nn->idtoname_cache);
 585         return 0;
 586 }
 587
 588 static bool
 589 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 590 {
 591         int ret;
 592         char buf[11];
 593
 594         if (namelen + 1 > sizeof(buf))
 595                 /* too long to represent a 32-bit id: */
 596                 return false;
 597         /* Just to make sure it's null-terminated: */
 598         memcpy(buf, name, namelen);
 599         buf[namelen] = '\0';
 600         ret = kstrtouint(buf, 10, id);
 601         return ret == 0;
 602 }
 603
 604 static __be32
 605 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 606 {
 607         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 608                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 609                         return 0;
 610                 /*
 611                  * otherwise, fall through and try idmapping, for
 612                  * backwards compatibility with clients sending names:
 613                  */
 614         return idmap_name_to_id(rqstp, type, name, namelen, id);
 615 }
 616
 617 static __be32 encode_name_from_id(struct xdr_stream *xdr,
 618                                   struct svc_rqst *rqstp, int type, u32 id)
 619 {
 620         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 621                 return encode_ascii_id(xdr, id);
 622         return idmap_id_to_name(xdr, rqstp, type, id);
 623 }
 624
 625 __be32
 626 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 627                 kuid_t *uid)
 628 {
 629         __be32 status;
 630         u32 id = -1;
 631         status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
 632         *uid = make_kuid(&init_user_ns, id);
 633         if (!uid_valid(*uid))
 634                 status = nfserr_badowner;
 635         return status;
 636 }
 637
 638 __be32
 639 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 640                 kgid_t *gid)
 641 {
 642         __be32 status;
 643         u32 id = -1;
 644         status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
 645         *gid = make_kgid(&init_user_ns, id);
 646         if (!gid_valid(*gid))
 647                 status = nfserr_badowner;
 648         return status;
 649 }
 650
 651 __be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 652                          kuid_t uid)
 653 {
 654         u32 id = from_kuid(&init_user_ns, uid);
 655         return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
 656 }
 657
 658 __be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 659                           kgid_t gid)
 660 {
 661         u32 id = from_kgid(&init_user_ns, gid);
 662         return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
 663 }