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