Pileus Git - ~andy/linux/blob - fs/posix_acl.c

   1 /*
   2  * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org>
   3  *
   4  * Fixes from William Schumacher incorporated on 15 March 2001.
   5  *    (Reported by Charles Bertsch, <CBertsch@microtest.com>).
   6  */
   7
   8 /*
   9  *  This file contains generic functions for manipulating
  10  *  POSIX 1003.1e draft standard 17 ACLs.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/atomic.h>
  16 #include <linux/fs.h>
  17 #include <linux/sched.h>
  18 #include <linux/posix_acl.h>
  19 #include <linux/posix_acl_xattr.h>
  20 #include <linux/xattr.h>
  21 #include <linux/export.h>
  22 #include <linux/user_namespace.h>
  23
  24 EXPORT_SYMBOL(posix_acl_init);
  25 EXPORT_SYMBOL(posix_acl_alloc);
  26 EXPORT_SYMBOL(posix_acl_valid);
  27 EXPORT_SYMBOL(posix_acl_equiv_mode);
  28 EXPORT_SYMBOL(posix_acl_from_mode);
  29
  30 struct posix_acl *get_acl(struct inode *inode, int type)
  31 {
  32         struct posix_acl *acl;
  33
  34         acl = get_cached_acl(inode, type);
  35         if (acl != ACL_NOT_CACHED)
  36                 return acl;
  37
  38         if (!IS_POSIXACL(inode))
  39                 return NULL;
  40
  41         /*
  42          * A filesystem can force a ACL callback by just never filling the
  43          * ACL cache. But normally you'd fill the cache either at inode
  44          * instantiation time, or on the first ->get_acl call.
  45          *
  46          * If the filesystem doesn't have a get_acl() function at all, we'll
  47          * just create the negative cache entry.
  48          */
  49         if (!inode->i_op->get_acl) {
  50                 set_cached_acl(inode, type, NULL);
  51                 return NULL;
  52         }
  53         return inode->i_op->get_acl(inode, type);
  54 }
  55 EXPORT_SYMBOL(get_acl);
  56
  57 /*
  58  * Init a fresh posix_acl
  59  */
  60 void
  61 posix_acl_init(struct posix_acl *acl, int count)
  62 {
  63         atomic_set(&acl->a_refcount, 1);
  64         acl->a_count = count;
  65 }
  66
  67 /*
  68  * Allocate a new ACL with the specified number of entries.
  69  */
  70 struct posix_acl *
  71 posix_acl_alloc(int count, gfp_t flags)
  72 {
  73         const size_t size = sizeof(struct posix_acl) +
  74                             count * sizeof(struct posix_acl_entry);
  75         struct posix_acl *acl = kmalloc(size, flags);
  76         if (acl)
  77                 posix_acl_init(acl, count);
  78         return acl;
  79 }
  80
  81 /*
  82  * Clone an ACL.
  83  */
  84 static struct posix_acl *
  85 posix_acl_clone(const struct posix_acl *acl, gfp_t flags)
  86 {
  87         struct posix_acl *clone = NULL;
  88
  89         if (acl) {
  90                 int size = sizeof(struct posix_acl) + acl->a_count *
  91                            sizeof(struct posix_acl_entry);
  92                 clone = kmemdup(acl, size, flags);
  93                 if (clone)
  94                         atomic_set(&clone->a_refcount, 1);
  95         }
  96         return clone;
  97 }
  98
  99 /*
 100  * Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
 101  */
 102 int
 103 posix_acl_valid(const struct posix_acl *acl)
 104 {
 105         const struct posix_acl_entry *pa, *pe;
 106         int state = ACL_USER_OBJ;
 107         kuid_t prev_uid = INVALID_UID;
 108         kgid_t prev_gid = INVALID_GID;
 109         int needs_mask = 0;
 110
 111         FOREACH_ACL_ENTRY(pa, acl, pe) {
 112                 if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
 113                         return -EINVAL;
 114                 switch (pa->e_tag) {
 115                         case ACL_USER_OBJ:
 116                                 if (state == ACL_USER_OBJ) {
 117                                         state = ACL_USER;
 118                                         break;
 119                                 }
 120                                 return -EINVAL;
 121
 122                         case ACL_USER:
 123                                 if (state != ACL_USER)
 124                                         return -EINVAL;
 125                                 if (!uid_valid(pa->e_uid))
 126                                         return -EINVAL;
 127                                 if (uid_valid(prev_uid) &&
 128                                     uid_lte(pa->e_uid, prev_uid))
 129                                         return -EINVAL;
 130                                 prev_uid = pa->e_uid;
 131                                 needs_mask = 1;
 132                                 break;
 133
 134                         case ACL_GROUP_OBJ:
 135                                 if (state == ACL_USER) {
 136                                         state = ACL_GROUP;
 137                                         break;
 138                                 }
 139                                 return -EINVAL;
 140
 141                         case ACL_GROUP:
 142                                 if (state != ACL_GROUP)
 143                                         return -EINVAL;
 144                                 if (!gid_valid(pa->e_gid))
 145                                         return -EINVAL;
 146                                 if (gid_valid(prev_gid) &&
 147                                     gid_lte(pa->e_gid, prev_gid))
 148                                         return -EINVAL;
 149                                 prev_gid = pa->e_gid;
 150                                 needs_mask = 1;
 151                                 break;
 152
 153                         case ACL_MASK:
 154                                 if (state != ACL_GROUP)
 155                                         return -EINVAL;
 156                                 state = ACL_OTHER;
 157                                 break;
 158
 159                         case ACL_OTHER:
 160                                 if (state == ACL_OTHER ||
 161                                     (state == ACL_GROUP && !needs_mask)) {
 162                                         state = 0;
 163                                         break;
 164                                 }
 165                                 return -EINVAL;
 166
 167                         default:
 168                                 return -EINVAL;
 169                 }
 170         }
 171         if (state == 0)
 172                 return 0;
 173         return -EINVAL;
 174 }
 175
 176 /*
 177  * Returns 0 if the acl can be exactly represented in the traditional
 178  * file mode permission bits, or else 1. Returns -E... on error.
 179  */
 180 int
 181 posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p)
 182 {
 183         const struct posix_acl_entry *pa, *pe;
 184         umode_t mode = 0;
 185         int not_equiv = 0;
 186
 187         FOREACH_ACL_ENTRY(pa, acl, pe) {
 188                 switch (pa->e_tag) {
 189                         case ACL_USER_OBJ:
 190                                 mode |= (pa->e_perm & S_IRWXO) << 6;
 191                                 break;
 192                         case ACL_GROUP_OBJ:
 193                                 mode |= (pa->e_perm & S_IRWXO) << 3;
 194                                 break;
 195                         case ACL_OTHER:
 196                                 mode |= pa->e_perm & S_IRWXO;
 197                                 break;
 198                         case ACL_MASK:
 199                                 mode = (mode & ~S_IRWXG) |
 200                                        ((pa->e_perm & S_IRWXO) << 3);
 201                                 not_equiv = 1;
 202                                 break;
 203                         case ACL_USER:
 204                         case ACL_GROUP:
 205                                 not_equiv = 1;
 206                                 break;
 207                         default:
 208                                 return -EINVAL;
 209                 }
 210         }
 211         if (mode_p)
 212                 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
 213         return not_equiv;
 214 }
 215
 216 /*
 217  * Create an ACL representing the file mode permission bits of an inode.
 218  */
 219 struct posix_acl *
 220 posix_acl_from_mode(umode_t mode, gfp_t flags)
 221 {
 222         struct posix_acl *acl = posix_acl_alloc(3, flags);
 223         if (!acl)
 224                 return ERR_PTR(-ENOMEM);
 225
 226         acl->a_entries[0].e_tag  = ACL_USER_OBJ;
 227         acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
 228
 229         acl->a_entries[1].e_tag  = ACL_GROUP_OBJ;
 230         acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
 231
 232         acl->a_entries[2].e_tag  = ACL_OTHER;
 233         acl->a_entries[2].e_perm = (mode & S_IRWXO);
 234         return acl;
 235 }
 236
 237 /*
 238  * Return 0 if current is granted want access to the inode
 239  * by the acl. Returns -E... otherwise.
 240  */
 241 int
 242 posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
 243 {
 244         const struct posix_acl_entry *pa, *pe, *mask_obj;
 245         int found = 0;
 246
 247         want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK;
 248
 249         FOREACH_ACL_ENTRY(pa, acl, pe) {
 250                 switch(pa->e_tag) {
 251                         case ACL_USER_OBJ:
 252                                 /* (May have been checked already) */
 253                                 if (uid_eq(inode->i_uid, current_fsuid()))
 254                                         goto check_perm;
 255                                 break;
 256                         case ACL_USER:
 257                                 if (uid_eq(pa->e_uid, current_fsuid()))
 258                                         goto mask;
 259                                 break;
 260                         case ACL_GROUP_OBJ:
 261                                 if (in_group_p(inode->i_gid)) {
 262                                         found = 1;
 263                                         if ((pa->e_perm & want) == want)
 264                                                 goto mask;
 265                                 }
 266                                 break;
 267                         case ACL_GROUP:
 268                                 if (in_group_p(pa->e_gid)) {
 269                                         found = 1;
 270                                         if ((pa->e_perm & want) == want)
 271                                                 goto mask;
 272                                 }
 273                                 break;
 274                         case ACL_MASK:
 275                                 break;
 276                         case ACL_OTHER:
 277                                 if (found)
 278                                         return -EACCES;
 279                                 else
 280                                         goto check_perm;
 281                         default:
 282                                 return -EIO;
 283                 }
 284         }
 285         return -EIO;
 286
 287 mask:
 288         for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
 289                 if (mask_obj->e_tag == ACL_MASK) {
 290                         if ((pa->e_perm & mask_obj->e_perm & want) == want)
 291                                 return 0;
 292                         return -EACCES;
 293                 }
 294         }
 295
 296 check_perm:
 297         if ((pa->e_perm & want) == want)
 298                 return 0;
 299         return -EACCES;
 300 }
 301
 302 /*
 303  * Modify acl when creating a new inode. The caller must ensure the acl is
 304  * only referenced once.
 305  *
 306  * mode_p initially must contain the mode parameter to the open() / creat()
 307  * system calls. All permissions that are not granted by the acl are removed.
 308  * The permissions in the acl are changed to reflect the mode_p parameter.
 309  */
 310 static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
 311 {
 312         struct posix_acl_entry *pa, *pe;
 313         struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
 314         umode_t mode = *mode_p;
 315         int not_equiv = 0;
 316
 317         /* assert(atomic_read(acl->a_refcount) == 1); */
 318
 319         FOREACH_ACL_ENTRY(pa, acl, pe) {
 320                 switch(pa->e_tag) {
 321                         case ACL_USER_OBJ:
 322                                 pa->e_perm &= (mode >> 6) | ~S_IRWXO;
 323                                 mode &= (pa->e_perm << 6) | ~S_IRWXU;
 324                                 break;
 325
 326                         case ACL_USER:
 327                         case ACL_GROUP:
 328                                 not_equiv = 1;
 329                                 break;
 330
 331                         case ACL_GROUP_OBJ:
 332                                 group_obj = pa;
 333                                 break;
 334
 335                         case ACL_OTHER:
 336                                 pa->e_perm &= mode | ~S_IRWXO;
 337                                 mode &= pa->e_perm | ~S_IRWXO;
 338                                 break;
 339
 340                         case ACL_MASK:
 341                                 mask_obj = pa;
 342                                 not_equiv = 1;
 343                                 break;
 344
 345                         default:
 346                                 return -EIO;
 347                 }
 348         }
 349
 350         if (mask_obj) {
 351                 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
 352                 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
 353         } else {
 354                 if (!group_obj)
 355                         return -EIO;
 356                 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
 357                 mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
 358         }
 359
 360         *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
 361         return not_equiv;
 362 }
 363
 364 /*
 365  * Modify the ACL for the chmod syscall.
 366  */
 367 static int posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
 368 {
 369         struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
 370         struct posix_acl_entry *pa, *pe;
 371
 372         /* assert(atomic_read(acl->a_refcount) == 1); */
 373
 374         FOREACH_ACL_ENTRY(pa, acl, pe) {
 375                 switch(pa->e_tag) {
 376                         case ACL_USER_OBJ:
 377                                 pa->e_perm = (mode & S_IRWXU) >> 6;
 378                                 break;
 379
 380                         case ACL_USER:
 381                         case ACL_GROUP:
 382                                 break;
 383
 384                         case ACL_GROUP_OBJ:
 385                                 group_obj = pa;
 386                                 break;
 387
 388                         case ACL_MASK:
 389                                 mask_obj = pa;
 390                                 break;
 391
 392                         case ACL_OTHER:
 393                                 pa->e_perm = (mode & S_IRWXO);
 394                                 break;
 395
 396                         default:
 397                                 return -EIO;
 398                 }
 399         }
 400
 401         if (mask_obj) {
 402                 mask_obj->e_perm = (mode & S_IRWXG) >> 3;
 403         } else {
 404                 if (!group_obj)
 405                         return -EIO;
 406                 group_obj->e_perm = (mode & S_IRWXG) >> 3;
 407         }
 408
 409         return 0;
 410 }
 411
 412 int
 413 posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
 414 {
 415         struct posix_acl *clone = posix_acl_clone(*acl, gfp);
 416         int err = -ENOMEM;
 417         if (clone) {
 418                 err = posix_acl_create_masq(clone, mode_p);
 419                 if (err < 0) {
 420                         posix_acl_release(clone);
 421                         clone = NULL;
 422                 }
 423         }
 424         posix_acl_release(*acl);
 425         *acl = clone;
 426         return err;
 427 }
 428 EXPORT_SYMBOL(posix_acl_create);
 429
 430 int
 431 posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
 432 {
 433         struct posix_acl *clone = posix_acl_clone(*acl, gfp);
 434         int err = -ENOMEM;
 435         if (clone) {
 436                 err = posix_acl_chmod_masq(clone, mode);
 437                 if (err) {
 438                         posix_acl_release(clone);
 439                         clone = NULL;
 440                 }
 441         }
 442         posix_acl_release(*acl);
 443         *acl = clone;
 444         return err;
 445 }
 446 EXPORT_SYMBOL(posix_acl_chmod);
 447
 448 /*
 449  * Fix up the uids and gids in posix acl extended attributes in place.
 450  */
 451 static void posix_acl_fix_xattr_userns(
 452         struct user_namespace *to, struct user_namespace *from,
 453         void *value, size_t size)
 454 {
 455         posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
 456         posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
 457         int count;
 458         kuid_t uid;
 459         kgid_t gid;
 460
 461         if (!value)
 462                 return;
 463         if (size < sizeof(posix_acl_xattr_header))
 464                 return;
 465         if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 466                 return;
 467
 468         count = posix_acl_xattr_count(size);
 469         if (count < 0)
 470                 return;
 471         if (count == 0)
 472                 return;
 473
 474         for (end = entry + count; entry != end; entry++) {
 475                 switch(le16_to_cpu(entry->e_tag)) {
 476                 case ACL_USER:
 477                         uid = make_kuid(from, le32_to_cpu(entry->e_id));
 478                         entry->e_id = cpu_to_le32(from_kuid(to, uid));
 479                         break;
 480                 case ACL_GROUP:
 481                         gid = make_kgid(from, le32_to_cpu(entry->e_id));
 482                         entry->e_id = cpu_to_le32(from_kgid(to, gid));
 483                         break;
 484                 default:
 485                         break;
 486                 }
 487         }
 488 }
 489
 490 void posix_acl_fix_xattr_from_user(void *value, size_t size)
 491 {
 492         struct user_namespace *user_ns = current_user_ns();
 493         if (user_ns == &init_user_ns)
 494                 return;
 495         posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
 496 }
 497
 498 void posix_acl_fix_xattr_to_user(void *value, size_t size)
 499 {
 500         struct user_namespace *user_ns = current_user_ns();
 501         if (user_ns == &init_user_ns)
 502                 return;
 503         posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
 504 }
 505
 506 /*
 507  * Convert from extended attribute to in-memory representation.
 508  */
 509 struct posix_acl *
 510 posix_acl_from_xattr(struct user_namespace *user_ns,
 511                      const void *value, size_t size)
 512 {
 513         posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
 514         posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
 515         int count;
 516         struct posix_acl *acl;
 517         struct posix_acl_entry *acl_e;
 518
 519         if (!value)
 520                 return NULL;
 521         if (size < sizeof(posix_acl_xattr_header))
 522                  return ERR_PTR(-EINVAL);
 523         if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 524                 return ERR_PTR(-EOPNOTSUPP);
 525
 526         count = posix_acl_xattr_count(size);
 527         if (count < 0)
 528                 return ERR_PTR(-EINVAL);
 529         if (count == 0)
 530                 return NULL;
 531
 532         acl = posix_acl_alloc(count, GFP_NOFS);
 533         if (!acl)
 534                 return ERR_PTR(-ENOMEM);
 535         acl_e = acl->a_entries;
 536
 537         for (end = entry + count; entry != end; acl_e++, entry++) {
 538                 acl_e->e_tag  = le16_to_cpu(entry->e_tag);
 539                 acl_e->e_perm = le16_to_cpu(entry->e_perm);
 540
 541                 switch(acl_e->e_tag) {
 542                         case ACL_USER_OBJ:
 543                         case ACL_GROUP_OBJ:
 544                         case ACL_MASK:
 545                         case ACL_OTHER:
 546                                 break;
 547
 548                         case ACL_USER:
 549                                 acl_e->e_uid =
 550                                         make_kuid(user_ns,
 551                                                   le32_to_cpu(entry->e_id));
 552                                 if (!uid_valid(acl_e->e_uid))
 553                                         goto fail;
 554                                 break;
 555                         case ACL_GROUP:
 556                                 acl_e->e_gid =
 557                                         make_kgid(user_ns,
 558                                                   le32_to_cpu(entry->e_id));
 559                                 if (!gid_valid(acl_e->e_gid))
 560                                         goto fail;
 561                                 break;
 562
 563                         default:
 564                                 goto fail;
 565                 }
 566         }
 567         return acl;
 568
 569 fail:
 570         posix_acl_release(acl);
 571         return ERR_PTR(-EINVAL);
 572 }
 573 EXPORT_SYMBOL (posix_acl_from_xattr);
 574
 575 /*
 576  * Convert from in-memory to extended attribute representation.
 577  */
 578 int
 579 posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
 580                    void *buffer, size_t size)
 581 {
 582         posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
 583         posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
 584         int real_size, n;
 585
 586         real_size = posix_acl_xattr_size(acl->a_count);
 587         if (!buffer)
 588                 return real_size;
 589         if (real_size > size)
 590                 return -ERANGE;
 591
 592         ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
 593
 594         for (n=0; n < acl->a_count; n++, ext_entry++) {
 595                 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
 596                 ext_entry->e_tag  = cpu_to_le16(acl_e->e_tag);
 597                 ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
 598                 switch(acl_e->e_tag) {
 599                 case ACL_USER:
 600                         ext_entry->e_id =
 601                                 cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
 602                         break;
 603                 case ACL_GROUP:
 604                         ext_entry->e_id =
 605                                 cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
 606                         break;
 607                 default:
 608                         ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 609                         break;
 610                 }
 611         }
 612         return real_size;
 613 }
 614 EXPORT_SYMBOL (posix_acl_to_xattr);
 615
 616 static int
 617 posix_acl_xattr_get(struct dentry *dentry, const char *name,
 618                 void *value, size_t size, int type)
 619 {
 620         struct posix_acl *acl;
 621         int error;
 622
 623         if (!IS_POSIXACL(dentry->d_inode))
 624                 return -EOPNOTSUPP;
 625         if (S_ISLNK(dentry->d_inode->i_mode))
 626                 return -EOPNOTSUPP;
 627
 628         acl = get_acl(dentry->d_inode, type);
 629         if (IS_ERR(acl))
 630                 return PTR_ERR(acl);
 631         if (acl == NULL)
 632                 return -ENODATA;
 633
 634         error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 635         posix_acl_release(acl);
 636
 637         return error;
 638 }
 639
 640 static int
 641 posix_acl_xattr_set(struct dentry *dentry, const char *name,
 642                 const void *value, size_t size, int flags, int type)
 643 {
 644         struct inode *inode = dentry->d_inode;
 645         struct posix_acl *acl = NULL;
 646         int ret;
 647
 648         if (!IS_POSIXACL(inode))
 649                 return -EOPNOTSUPP;
 650         if (!inode->i_op->set_acl)
 651                 return -EOPNOTSUPP;
 652
 653         if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
 654                 return value ? -EACCES : 0;
 655         if (!inode_owner_or_capable(inode))
 656                 return -EPERM;
 657
 658         if (value) {
 659                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
 660                 if (IS_ERR(acl))
 661                         return PTR_ERR(acl);
 662
 663                 if (acl) {
 664                         ret = posix_acl_valid(acl);
 665                         if (ret)
 666                                 goto out;
 667                 }
 668         }
 669
 670         ret = inode->i_op->set_acl(inode, acl, type);
 671 out:
 672         posix_acl_release(acl);
 673         return ret;
 674 }
 675
 676 static size_t
 677 posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
 678                 const char *name, size_t name_len, int type)
 679 {
 680         const char *xname;
 681         size_t size;
 682
 683         if (!IS_POSIXACL(dentry->d_inode))
 684                 return -EOPNOTSUPP;
 685         if (S_ISLNK(dentry->d_inode->i_mode))
 686                 return -EOPNOTSUPP;
 687
 688         if (type == ACL_TYPE_ACCESS)
 689                 xname = POSIX_ACL_XATTR_ACCESS;
 690         else
 691                 xname = POSIX_ACL_XATTR_DEFAULT;
 692
 693         size = strlen(xname) + 1;
 694         if (list && size <= list_size)
 695                 memcpy(list, xname, size);
 696         return size;
 697 }
 698
 699 const struct xattr_handler posix_acl_access_xattr_handler = {
 700         .prefix = POSIX_ACL_XATTR_ACCESS,
 701         .flags = ACL_TYPE_ACCESS,
 702         .list = posix_acl_xattr_list,
 703         .get = posix_acl_xattr_get,
 704         .set = posix_acl_xattr_set,
 705 };
 706 EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
 707
 708 const struct xattr_handler posix_acl_default_xattr_handler = {
 709         .prefix = POSIX_ACL_XATTR_DEFAULT,
 710         .flags = ACL_TYPE_DEFAULT,
 711         .list = posix_acl_xattr_list,
 712         .get = posix_acl_xattr_get,
 713         .set = posix_acl_xattr_set,
 714 };
 715 EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);