1 #include <linux/capability.h> 2 #include <linux/fs.h> 3 #include <linux/posix_acl.h> 4 #include "reiserfs.h" 5 #include <linux/errno.h> 6 #include <linux/pagemap.h> 7 #include <linux/xattr.h> 8 #include <linux/slab.h> 9 #include <linux/posix_acl_xattr.h> 10 #include "xattr.h" 11 #include "acl.h" 12 #include <asm/uaccess.h> 13 14 static int reiserfs_set_acl(struct reiserfs_transaction_handle *th, 15 struct inode *inode, int type, 16 struct posix_acl *acl); 17 18 static int 19 posix_acl_set(struct dentry *dentry, const char *name, const void *value, 20 size_t size, int flags, int type) 21 { 22 struct inode *inode = dentry->d_inode; 23 struct posix_acl *acl; 24 int error, error2; 25 struct reiserfs_transaction_handle th; 26 size_t jcreate_blocks; 27 if (!reiserfs_posixacl(inode->i_sb)) 28 return -EOPNOTSUPP; 29 if (!inode_owner_or_capable(inode)) 30 return -EPERM; 31 32 if (value) { 33 acl = posix_acl_from_xattr(&init_user_ns, value, size); 34 if (IS_ERR(acl)) { 35 return PTR_ERR(acl); 36 } else if (acl) { 37 error = posix_acl_valid(acl); 38 if (error) 39 goto release_and_out; 40 } 41 } else 42 acl = NULL; 43 44 /* Pessimism: We can't assume that anything from the xattr root up 45 * has been created. */ 46 47 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + 48 reiserfs_xattr_nblocks(inode, size) * 2; 49 50 reiserfs_write_lock(inode->i_sb); 51 error = journal_begin(&th, inode->i_sb, jcreate_blocks); 52 if (error == 0) { 53 error = reiserfs_set_acl(&th, inode, type, acl); 54 error2 = journal_end(&th, inode->i_sb, jcreate_blocks); 55 if (error2) 56 error = error2; 57 } 58 reiserfs_write_unlock(inode->i_sb); 59 60 release_and_out: 61 posix_acl_release(acl); 62 return error; 63 } 64 65 static int 66 posix_acl_get(struct dentry *dentry, const char *name, void *buffer, 67 size_t size, int type) 68 { 69 struct posix_acl *acl; 70 int error; 71 72 if (!reiserfs_posixacl(dentry->d_sb)) 73 return -EOPNOTSUPP; 74 75 acl = reiserfs_get_acl(dentry->d_inode, type); 76 if (IS_ERR(acl)) 77 return PTR_ERR(acl); 78 if (acl == NULL) 79 return -ENODATA; 80 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); 81 posix_acl_release(acl); 82 83 return error; 84 } 85 86 /* 87 * Convert from filesystem to in-memory representation. 88 */ 89 static struct posix_acl *posix_acl_from_disk(const void *value, size_t size) 90 { 91 const char *end = (char *)value + size; 92 int n, count; 93 struct posix_acl *acl; 94 95 if (!value) 96 return NULL; 97 if (size < sizeof(reiserfs_acl_header)) 98 return ERR_PTR(-EINVAL); 99 if (((reiserfs_acl_header *) value)->a_version != 100 cpu_to_le32(REISERFS_ACL_VERSION)) 101 return ERR_PTR(-EINVAL); 102 value = (char *)value + sizeof(reiserfs_acl_header); 103 count = reiserfs_acl_count(size); 104 if (count < 0) 105 return ERR_PTR(-EINVAL); 106 if (count == 0) 107 return NULL; 108 acl = posix_acl_alloc(count, GFP_NOFS); 109 if (!acl) 110 return ERR_PTR(-ENOMEM); 111 for (n = 0; n < count; n++) { 112 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; 113 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) 114 goto fail; 115 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); 116 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); 117 switch (acl->a_entries[n].e_tag) { 118 case ACL_USER_OBJ: 119 case ACL_GROUP_OBJ: 120 case ACL_MASK: 121 case ACL_OTHER: 122 value = (char *)value + 123 sizeof(reiserfs_acl_entry_short); 124 break; 125 126 case ACL_USER: 127 value = (char *)value + sizeof(reiserfs_acl_entry); 128 if ((char *)value > end) 129 goto fail; 130 acl->a_entries[n].e_uid = 131 make_kuid(&init_user_ns, 132 le32_to_cpu(entry->e_id)); 133 break; 134 case ACL_GROUP: 135 value = (char *)value + sizeof(reiserfs_acl_entry); 136 if ((char *)value > end) 137 goto fail; 138 acl->a_entries[n].e_gid = 139 make_kgid(&init_user_ns, 140 le32_to_cpu(entry->e_id)); 141 break; 142 143 default: 144 goto fail; 145 } 146 } 147 if (value != end) 148 goto fail; 149 return acl; 150 151 fail: 152 posix_acl_release(acl); 153 return ERR_PTR(-EINVAL); 154 } 155 156 /* 157 * Convert from in-memory to filesystem representation. 158 */ 159 static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size) 160 { 161 reiserfs_acl_header *ext_acl; 162 char *e; 163 int n; 164 165 *size = reiserfs_acl_size(acl->a_count); 166 ext_acl = kmalloc(sizeof(reiserfs_acl_header) + 167 acl->a_count * 168 sizeof(reiserfs_acl_entry), 169 GFP_NOFS); 170 if (!ext_acl) 171 return ERR_PTR(-ENOMEM); 172 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); 173 e = (char *)ext_acl + sizeof(reiserfs_acl_header); 174 for (n = 0; n < acl->a_count; n++) { 175 const struct posix_acl_entry *acl_e = &acl->a_entries[n]; 176 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; 177 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); 178 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); 179 switch (acl->a_entries[n].e_tag) { 180 case ACL_USER: 181 entry->e_id = cpu_to_le32( 182 from_kuid(&init_user_ns, acl_e->e_uid)); 183 e += sizeof(reiserfs_acl_entry); 184 break; 185 case ACL_GROUP: 186 entry->e_id = cpu_to_le32( 187 from_kgid(&init_user_ns, acl_e->e_gid)); 188 e += sizeof(reiserfs_acl_entry); 189 break; 190 191 case ACL_USER_OBJ: 192 case ACL_GROUP_OBJ: 193 case ACL_MASK: 194 case ACL_OTHER: 195 e += sizeof(reiserfs_acl_entry_short); 196 break; 197 198 default: 199 goto fail; 200 } 201 } 202 return (char *)ext_acl; 203 204 fail: 205 kfree(ext_acl); 206 return ERR_PTR(-EINVAL); 207 } 208 209 /* 210 * Inode operation get_posix_acl(). 211 * 212 * inode->i_mutex: down 213 * BKL held [before 2.5.x] 214 */ 215 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) 216 { 217 char *name, *value; 218 struct posix_acl *acl; 219 int size; 220 int retval; 221 222 acl = get_cached_acl(inode, type); 223 if (acl != ACL_NOT_CACHED) 224 return acl; 225 226 switch (type) { 227 case ACL_TYPE_ACCESS: 228 name = POSIX_ACL_XATTR_ACCESS; 229 break; 230 case ACL_TYPE_DEFAULT: 231 name = POSIX_ACL_XATTR_DEFAULT; 232 break; 233 default: 234 BUG(); 235 } 236 237 size = reiserfs_xattr_get(inode, name, NULL, 0); 238 if (size < 0) { 239 if (size == -ENODATA || size == -ENOSYS) { 240 set_cached_acl(inode, type, NULL); 241 return NULL; 242 } 243 return ERR_PTR(size); 244 } 245 246 value = kmalloc(size, GFP_NOFS); 247 if (!value) 248 return ERR_PTR(-ENOMEM); 249 250 retval = reiserfs_xattr_get(inode, name, value, size); 251 if (retval == -ENODATA || retval == -ENOSYS) { 252 /* This shouldn't actually happen as it should have 253 been caught above.. but just in case */ 254 acl = NULL; 255 } else if (retval < 0) { 256 acl = ERR_PTR(retval); 257 } else { 258 acl = posix_acl_from_disk(value, retval); 259 } 260 if (!IS_ERR(acl)) 261 set_cached_acl(inode, type, acl); 262 263 kfree(value); 264 return acl; 265 } 266 267 /* 268 * Inode operation set_posix_acl(). 269 * 270 * inode->i_mutex: down 271 * BKL held [before 2.5.x] 272 */ 273 static int 274 reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, 275 int type, struct posix_acl *acl) 276 { 277 char *name; 278 void *value = NULL; 279 size_t size = 0; 280 int error; 281 282 if (S_ISLNK(inode->i_mode)) 283 return -EOPNOTSUPP; 284 285 switch (type) { 286 case ACL_TYPE_ACCESS: 287 name = POSIX_ACL_XATTR_ACCESS; 288 if (acl) { 289 error = posix_acl_equiv_mode(acl, &inode->i_mode); 290 if (error < 0) 291 return error; 292 else { 293 if (error == 0) 294 acl = NULL; 295 } 296 } 297 break; 298 case ACL_TYPE_DEFAULT: 299 name = POSIX_ACL_XATTR_DEFAULT; 300 if (!S_ISDIR(inode->i_mode)) 301 return acl ? -EACCES : 0; 302 break; 303 default: 304 return -EINVAL; 305 } 306 307 if (acl) { 308 value = posix_acl_to_disk(acl, &size); 309 if (IS_ERR(value)) 310 return (int)PTR_ERR(value); 311 } 312 313 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); 314 315 /* 316 * Ensure that the inode gets dirtied if we're only using 317 * the mode bits and an old ACL didn't exist. We don't need 318 * to check if the inode is hashed here since we won't get 319 * called by reiserfs_inherit_default_acl(). 320 */ 321 if (error == -ENODATA) { 322 error = 0; 323 if (type == ACL_TYPE_ACCESS) { 324 inode->i_ctime = CURRENT_TIME_SEC; 325 mark_inode_dirty(inode); 326 } 327 } 328 329 kfree(value); 330 331 if (!error) 332 set_cached_acl(inode, type, acl); 333 334 return error; 335 } 336 337 /* dir->i_mutex: locked, 338 * inode is new and not released into the wild yet */ 339 int 340 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, 341 struct inode *dir, struct dentry *dentry, 342 struct inode *inode) 343 { 344 struct posix_acl *acl; 345 int err = 0; 346 347 /* ACLs only get applied to files and directories */ 348 if (S_ISLNK(inode->i_mode)) 349 return 0; 350 351 /* ACLs can only be used on "new" objects, so if it's an old object 352 * there is nothing to inherit from */ 353 if (get_inode_sd_version(dir) == STAT_DATA_V1) 354 goto apply_umask; 355 356 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This 357 * would be useless since permissions are ignored, and a pain because 358 * it introduces locking cycles */ 359 if (IS_PRIVATE(dir)) { 360 inode->i_flags |= S_PRIVATE; 361 goto apply_umask; 362 } 363 364 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT); 365 if (IS_ERR(acl)) 366 return PTR_ERR(acl); 367 368 if (acl) { 369 /* Copy the default ACL to the default ACL of a new directory */ 370 if (S_ISDIR(inode->i_mode)) { 371 err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, 372 acl); 373 if (err) 374 goto cleanup; 375 } 376 377 /* Now we reconcile the new ACL and the mode, 378 potentially modifying both */ 379 err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode); 380 if (err < 0) 381 return err; 382 383 /* If we need an ACL.. */ 384 if (err > 0) 385 err = reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl); 386 cleanup: 387 posix_acl_release(acl); 388 } else { 389 apply_umask: 390 /* no ACL, apply umask */ 391 inode->i_mode &= ~current_umask(); 392 } 393 394 return err; 395 } 396 397 /* This is used to cache the default acl before a new object is created. 398 * The biggest reason for this is to get an idea of how many blocks will 399 * actually be required for the create operation if we must inherit an ACL. 400 * An ACL write can add up to 3 object creations and an additional file write 401 * so we'd prefer not to reserve that many blocks in the journal if we can. 402 * It also has the advantage of not loading the ACL with a transaction open, 403 * this may seem silly, but if the owner of the directory is doing the 404 * creation, the ACL may not be loaded since the permissions wouldn't require 405 * it. 406 * We return the number of blocks required for the transaction. 407 */ 408 int reiserfs_cache_default_acl(struct inode *inode) 409 { 410 struct posix_acl *acl; 411 int nblocks = 0; 412 413 if (IS_PRIVATE(inode)) 414 return 0; 415 416 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT); 417 418 if (acl && !IS_ERR(acl)) { 419 int size = reiserfs_acl_size(acl->a_count); 420 421 /* Other xattrs can be created during inode creation. We don't 422 * want to claim too many blocks, so we check to see if we 423 * we need to create the tree to the xattrs, and then we 424 * just want two files. */ 425 nblocks = reiserfs_xattr_jcreate_nblocks(inode); 426 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); 427 428 REISERFS_I(inode)->i_flags |= i_has_xattr_dir; 429 430 /* We need to account for writes + bitmaps for two files */ 431 nblocks += reiserfs_xattr_nblocks(inode, size) * 4; 432 posix_acl_release(acl); 433 } 434 435 return nblocks; 436 } 437 438 int reiserfs_acl_chmod(struct inode *inode) 439 { 440 struct reiserfs_transaction_handle th; 441 struct posix_acl *acl; 442 size_t size; 443 int depth; 444 int error; 445 446 if (S_ISLNK(inode->i_mode)) 447 return -EOPNOTSUPP; 448 449 if (get_inode_sd_version(inode) == STAT_DATA_V1 || 450 !reiserfs_posixacl(inode->i_sb)) { 451 return 0; 452 } 453 454 reiserfs_write_unlock(inode->i_sb); 455 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); 456 reiserfs_write_lock(inode->i_sb); 457 if (!acl) 458 return 0; 459 if (IS_ERR(acl)) 460 return PTR_ERR(acl); 461 error = posix_acl_chmod(&acl, GFP_NOFS, inode->i_mode); 462 if (error) 463 return error; 464 465 size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count)); 466 depth = reiserfs_write_lock_once(inode->i_sb); 467 error = journal_begin(&th, inode->i_sb, size * 2); 468 if (!error) { 469 int error2; 470 error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl); 471 error2 = journal_end(&th, inode->i_sb, size * 2); 472 if (error2) 473 error = error2; 474 } 475 reiserfs_write_unlock_once(inode->i_sb, depth); 476 posix_acl_release(acl); 477 return error; 478 } 479 480 static size_t posix_acl_access_list(struct dentry *dentry, char *list, 481 size_t list_size, const char *name, 482 size_t name_len, int type) 483 { 484 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); 485 if (!reiserfs_posixacl(dentry->d_sb)) 486 return 0; 487 if (list && size <= list_size) 488 memcpy(list, POSIX_ACL_XATTR_ACCESS, size); 489 return size; 490 } 491 492 const struct xattr_handler reiserfs_posix_acl_access_handler = { 493 .prefix = POSIX_ACL_XATTR_ACCESS, 494 .flags = ACL_TYPE_ACCESS, 495 .get = posix_acl_get, 496 .set = posix_acl_set, 497 .list = posix_acl_access_list, 498 }; 499 500 static size_t posix_acl_default_list(struct dentry *dentry, char *list, 501 size_t list_size, const char *name, 502 size_t name_len, int type) 503 { 504 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); 505 if (!reiserfs_posixacl(dentry->d_sb)) 506 return 0; 507 if (list && size <= list_size) 508 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); 509 return size; 510 } 511 512 const struct xattr_handler reiserfs_posix_acl_default_handler = { 513 .prefix = POSIX_ACL_XATTR_DEFAULT, 514 .flags = ACL_TYPE_DEFAULT, 515 .get = posix_acl_get, 516 .set = posix_acl_set, 517 .list = posix_acl_default_list, 518 }; 519