1 /* 2 * linux/fs/ext4/xattr.c 3 * 4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 5 * 6 * Fix by Harrison Xing <harrison@mountainviewdata.com>. 7 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>. 8 * Extended attributes for symlinks and special files added per 9 * suggestion of Luka Renko <luka.renko@hermes.si>. 10 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, 11 * Red Hat Inc. 12 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz 13 * and Andreas Gruenbacher <agruen@suse.de>. 14 */ 15 16 /* 17 * Extended attributes are stored directly in inodes (on file systems with 18 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl 19 * field contains the block number if an inode uses an additional block. All 20 * attributes must fit in the inode and one additional block. Blocks that 21 * contain the identical set of attributes may be shared among several inodes. 22 * Identical blocks are detected by keeping a cache of blocks that have 23 * recently been accessed. 24 * 25 * The attributes in inodes and on blocks have a different header; the entries 26 * are stored in the same format: 27 * 28 * +------------------+ 29 * | header | 30 * | entry 1 | | 31 * | entry 2 | | growing downwards 32 * | entry 3 | v 33 * | four null bytes | 34 * | . . . | 35 * | value 1 | ^ 36 * | value 3 | | growing upwards 37 * | value 2 | | 38 * +------------------+ 39 * 40 * The header is followed by multiple entry descriptors. In disk blocks, the 41 * entry descriptors are kept sorted. In inodes, they are unsorted. The 42 * attribute values are aligned to the end of the block in no specific order. 43 * 44 * Locking strategy 45 * ---------------- 46 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem. 47 * EA blocks are only changed if they are exclusive to an inode, so 48 * holding xattr_sem also means that nothing but the EA block's reference 49 * count can change. Multiple writers to the same block are synchronized 50 * by the buffer lock. 51 */ 52 53 #include <linux/init.h> 54 #include <linux/fs.h> 55 #include <linux/slab.h> 56 #include <linux/mbcache.h> 57 #include <linux/quotaops.h> 58 #include "ext4_jbd2.h" 59 #include "ext4.h" 60 #include "xattr.h" 61 #include "acl.h" 62 63 #ifdef EXT4_XATTR_DEBUG 64 # define ea_idebug(inode, fmt, ...) \ 65 printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \ 66 inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__) 67 # define ea_bdebug(bh, fmt, ...) \ 68 printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \ 69 bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__) 70 #else 71 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 72 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 73 #endif 74 75 static void ext4_xattr_block_cache_insert(struct mb_cache *, 76 struct buffer_head *); 77 static struct buffer_head * 78 ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *, 79 struct mb_cache_entry **); 80 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 81 size_t value_count); 82 static void ext4_xattr_rehash(struct ext4_xattr_header *); 83 84 static const struct xattr_handler * const ext4_xattr_handler_map[] = { 85 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, 86 #ifdef CONFIG_EXT4_FS_POSIX_ACL 87 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 88 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 89 #endif 90 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, 91 #ifdef CONFIG_EXT4_FS_SECURITY 92 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, 93 #endif 94 }; 95 96 const struct xattr_handler *ext4_xattr_handlers[] = { 97 &ext4_xattr_user_handler, 98 &ext4_xattr_trusted_handler, 99 #ifdef CONFIG_EXT4_FS_POSIX_ACL 100 &posix_acl_access_xattr_handler, 101 &posix_acl_default_xattr_handler, 102 #endif 103 #ifdef CONFIG_EXT4_FS_SECURITY 104 &ext4_xattr_security_handler, 105 #endif 106 NULL 107 }; 108 109 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ 110 inode->i_sb->s_fs_info)->s_ea_block_cache) 111 112 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \ 113 inode->i_sb->s_fs_info)->s_ea_inode_cache) 114 115 static int 116 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 117 struct inode *inode); 118 119 #ifdef CONFIG_LOCKDEP 120 void ext4_xattr_inode_set_class(struct inode *ea_inode) 121 { 122 lockdep_set_subclass(&ea_inode->i_rwsem, 1); 123 } 124 #endif 125 126 static __le32 ext4_xattr_block_csum(struct inode *inode, 127 sector_t block_nr, 128 struct ext4_xattr_header *hdr) 129 { 130 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 131 __u32 csum; 132 __le64 dsk_block_nr = cpu_to_le64(block_nr); 133 __u32 dummy_csum = 0; 134 int offset = offsetof(struct ext4_xattr_header, h_checksum); 135 136 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr, 137 sizeof(dsk_block_nr)); 138 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset); 139 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 140 offset += sizeof(dummy_csum); 141 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset, 142 EXT4_BLOCK_SIZE(inode->i_sb) - offset); 143 144 return cpu_to_le32(csum); 145 } 146 147 static int ext4_xattr_block_csum_verify(struct inode *inode, 148 struct buffer_head *bh) 149 { 150 struct ext4_xattr_header *hdr = BHDR(bh); 151 int ret = 1; 152 153 if (ext4_has_metadata_csum(inode->i_sb)) { 154 lock_buffer(bh); 155 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, 156 bh->b_blocknr, hdr)); 157 unlock_buffer(bh); 158 } 159 return ret; 160 } 161 162 static void ext4_xattr_block_csum_set(struct inode *inode, 163 struct buffer_head *bh) 164 { 165 if (ext4_has_metadata_csum(inode->i_sb)) 166 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, 167 bh->b_blocknr, BHDR(bh)); 168 } 169 170 static inline const struct xattr_handler * 171 ext4_xattr_handler(int name_index) 172 { 173 const struct xattr_handler *handler = NULL; 174 175 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) 176 handler = ext4_xattr_handler_map[name_index]; 177 return handler; 178 } 179 180 static int 181 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, 182 void *value_start) 183 { 184 struct ext4_xattr_entry *e = entry; 185 186 /* Find the end of the names list */ 187 while (!IS_LAST_ENTRY(e)) { 188 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); 189 if ((void *)next >= end) 190 return -EFSCORRUPTED; 191 e = next; 192 } 193 194 /* Check the values */ 195 while (!IS_LAST_ENTRY(entry)) { 196 if (entry->e_value_size != 0 && 197 entry->e_value_inum == 0) { 198 u16 offs = le16_to_cpu(entry->e_value_offs); 199 u32 size = le32_to_cpu(entry->e_value_size); 200 void *value; 201 202 /* 203 * The value cannot overlap the names, and the value 204 * with padding cannot extend beyond 'end'. Check both 205 * the padded and unpadded sizes, since the size may 206 * overflow to 0 when adding padding. 207 */ 208 if (offs > end - value_start) 209 return -EFSCORRUPTED; 210 value = value_start + offs; 211 if (value < (void *)e + sizeof(u32) || 212 size > end - value || 213 EXT4_XATTR_SIZE(size) > end - value) 214 return -EFSCORRUPTED; 215 } 216 entry = EXT4_XATTR_NEXT(entry); 217 } 218 219 return 0; 220 } 221 222 static inline int 223 ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh) 224 { 225 int error; 226 227 if (buffer_verified(bh)) 228 return 0; 229 230 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || 231 BHDR(bh)->h_blocks != cpu_to_le32(1)) 232 return -EFSCORRUPTED; 233 if (!ext4_xattr_block_csum_verify(inode, bh)) 234 return -EFSBADCRC; 235 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, 236 bh->b_data); 237 if (!error) 238 set_buffer_verified(bh); 239 return error; 240 } 241 242 static int 243 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, 244 void *end, const char *function, unsigned int line) 245 { 246 int error = -EFSCORRUPTED; 247 248 if (end - (void *)header < sizeof(*header) + sizeof(u32) || 249 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC))) 250 goto errout; 251 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header)); 252 errout: 253 if (error) 254 __ext4_error_inode(inode, function, line, 0, 255 "corrupted in-inode xattr"); 256 return error; 257 } 258 259 #define xattr_check_inode(inode, header, end) \ 260 __xattr_check_inode((inode), (header), (end), __func__, __LINE__) 261 262 static int 263 ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, 264 const char *name, int sorted) 265 { 266 struct ext4_xattr_entry *entry; 267 size_t name_len; 268 int cmp = 1; 269 270 if (name == NULL) 271 return -EINVAL; 272 name_len = strlen(name); 273 entry = *pentry; 274 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 275 cmp = name_index - entry->e_name_index; 276 if (!cmp) 277 cmp = name_len - entry->e_name_len; 278 if (!cmp) 279 cmp = memcmp(name, entry->e_name, name_len); 280 if (cmp <= 0 && (sorted || cmp == 0)) 281 break; 282 } 283 *pentry = entry; 284 return cmp ? -ENODATA : 0; 285 } 286 287 static u32 288 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size) 289 { 290 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size); 291 } 292 293 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode) 294 { 295 return ((u64)ea_inode->i_ctime.tv_sec << 32) | 296 ((u32)ea_inode->i_version); 297 } 298 299 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count) 300 { 301 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32); 302 ea_inode->i_version = (u32)ref_count; 303 } 304 305 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode) 306 { 307 return (u32)ea_inode->i_atime.tv_sec; 308 } 309 310 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash) 311 { 312 ea_inode->i_atime.tv_sec = hash; 313 } 314 315 /* 316 * Read the EA value from an inode. 317 */ 318 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) 319 { 320 int blocksize = 1 << ea_inode->i_blkbits; 321 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits; 322 int tail_size = (size % blocksize) ?: blocksize; 323 struct buffer_head *bhs_inline[8]; 324 struct buffer_head **bhs = bhs_inline; 325 int i, ret; 326 327 if (bh_count > ARRAY_SIZE(bhs_inline)) { 328 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS); 329 if (!bhs) 330 return -ENOMEM; 331 } 332 333 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count, 334 true /* wait */, bhs); 335 if (ret) 336 goto free_bhs; 337 338 for (i = 0; i < bh_count; i++) { 339 /* There shouldn't be any holes in ea_inode. */ 340 if (!bhs[i]) { 341 ret = -EFSCORRUPTED; 342 goto put_bhs; 343 } 344 memcpy((char *)buf + blocksize * i, bhs[i]->b_data, 345 i < bh_count - 1 ? blocksize : tail_size); 346 } 347 ret = 0; 348 put_bhs: 349 for (i = 0; i < bh_count; i++) 350 brelse(bhs[i]); 351 free_bhs: 352 if (bhs != bhs_inline) 353 kfree(bhs); 354 return ret; 355 } 356 357 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, 358 struct inode **ea_inode) 359 { 360 struct inode *inode; 361 int err; 362 363 inode = ext4_iget(parent->i_sb, ea_ino); 364 if (IS_ERR(inode)) { 365 err = PTR_ERR(inode); 366 ext4_error(parent->i_sb, 367 "error while reading EA inode %lu err=%d", ea_ino, 368 err); 369 return err; 370 } 371 372 if (is_bad_inode(inode)) { 373 ext4_error(parent->i_sb, 374 "error while reading EA inode %lu is_bad_inode", 375 ea_ino); 376 err = -EIO; 377 goto error; 378 } 379 380 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { 381 ext4_error(parent->i_sb, 382 "EA inode %lu does not have EXT4_EA_INODE_FL flag", 383 ea_ino); 384 err = -EINVAL; 385 goto error; 386 } 387 388 *ea_inode = inode; 389 return 0; 390 error: 391 iput(inode); 392 return err; 393 } 394 395 static int 396 ext4_xattr_inode_verify_hashes(struct inode *ea_inode, 397 struct ext4_xattr_entry *entry, void *buffer, 398 size_t size) 399 { 400 u32 hash; 401 402 /* Verify stored hash matches calculated hash. */ 403 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size); 404 if (hash != ext4_xattr_inode_get_hash(ea_inode)) 405 return -EFSCORRUPTED; 406 407 if (entry) { 408 __le32 e_hash, tmp_data; 409 410 /* Verify entry hash. */ 411 tmp_data = cpu_to_le32(hash); 412 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len, 413 &tmp_data, 1); 414 if (e_hash != entry->e_hash) 415 return -EFSCORRUPTED; 416 } 417 return 0; 418 } 419 420 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec) 421 422 /* 423 * Read xattr value from the EA inode. 424 */ 425 static int 426 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry, 427 void *buffer, size_t size) 428 { 429 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 430 struct inode *ea_inode; 431 int err; 432 433 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum), 434 &ea_inode); 435 if (err) { 436 ea_inode = NULL; 437 goto out; 438 } 439 440 if (i_size_read(ea_inode) != size) { 441 ext4_warning_inode(ea_inode, 442 "ea_inode file size=%llu entry size=%zu", 443 i_size_read(ea_inode), size); 444 err = -EFSCORRUPTED; 445 goto out; 446 } 447 448 err = ext4_xattr_inode_read(ea_inode, buffer, size); 449 if (err) 450 goto out; 451 452 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer, size); 453 /* 454 * Compatibility check for old Lustre ea_inode implementation. Old 455 * version does not have hash validation, but it has a backpointer 456 * from ea_inode to the parent inode. 457 */ 458 if (err == -EFSCORRUPTED) { 459 if (EXT4_XATTR_INODE_GET_PARENT(ea_inode) != inode->i_ino || 460 ea_inode->i_generation != inode->i_generation) { 461 ext4_warning_inode(ea_inode, 462 "EA inode hash validation failed"); 463 goto out; 464 } 465 /* Do not add ea_inode to the cache. */ 466 ea_inode_cache = NULL; 467 err = 0; 468 } else if (err) 469 goto out; 470 471 if (ea_inode_cache) 472 mb_cache_entry_create(ea_inode_cache, GFP_NOFS, 473 ext4_xattr_inode_get_hash(ea_inode), 474 ea_inode->i_ino, true /* reusable */); 475 out: 476 iput(ea_inode); 477 return err; 478 } 479 480 static int 481 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, 482 void *buffer, size_t buffer_size) 483 { 484 struct buffer_head *bh = NULL; 485 struct ext4_xattr_entry *entry; 486 size_t size; 487 int error; 488 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 489 490 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 491 name_index, name, buffer, (long)buffer_size); 492 493 error = -ENODATA; 494 if (!EXT4_I(inode)->i_file_acl) 495 goto cleanup; 496 ea_idebug(inode, "reading block %llu", 497 (unsigned long long)EXT4_I(inode)->i_file_acl); 498 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 499 if (!bh) 500 goto cleanup; 501 ea_bdebug(bh, "b_count=%d, refcount=%d", 502 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 503 if (ext4_xattr_check_block(inode, bh)) { 504 EXT4_ERROR_INODE(inode, "bad block %llu", 505 EXT4_I(inode)->i_file_acl); 506 error = -EFSCORRUPTED; 507 goto cleanup; 508 } 509 ext4_xattr_block_cache_insert(ea_block_cache, bh); 510 entry = BFIRST(bh); 511 error = ext4_xattr_find_entry(&entry, name_index, name, 1); 512 if (error) 513 goto cleanup; 514 size = le32_to_cpu(entry->e_value_size); 515 if (buffer) { 516 error = -ERANGE; 517 if (size > buffer_size) 518 goto cleanup; 519 if (entry->e_value_inum) { 520 error = ext4_xattr_inode_get(inode, entry, buffer, 521 size); 522 if (error) 523 goto cleanup; 524 } else { 525 memcpy(buffer, bh->b_data + 526 le16_to_cpu(entry->e_value_offs), size); 527 } 528 } 529 error = size; 530 531 cleanup: 532 brelse(bh); 533 return error; 534 } 535 536 int 537 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 538 void *buffer, size_t buffer_size) 539 { 540 struct ext4_xattr_ibody_header *header; 541 struct ext4_xattr_entry *entry; 542 struct ext4_inode *raw_inode; 543 struct ext4_iloc iloc; 544 size_t size; 545 void *end; 546 int error; 547 548 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 549 return -ENODATA; 550 error = ext4_get_inode_loc(inode, &iloc); 551 if (error) 552 return error; 553 raw_inode = ext4_raw_inode(&iloc); 554 header = IHDR(inode, raw_inode); 555 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 556 error = xattr_check_inode(inode, header, end); 557 if (error) 558 goto cleanup; 559 entry = IFIRST(header); 560 error = ext4_xattr_find_entry(&entry, name_index, name, 0); 561 if (error) 562 goto cleanup; 563 size = le32_to_cpu(entry->e_value_size); 564 if (buffer) { 565 error = -ERANGE; 566 if (size > buffer_size) 567 goto cleanup; 568 if (entry->e_value_inum) { 569 error = ext4_xattr_inode_get(inode, entry, buffer, 570 size); 571 if (error) 572 goto cleanup; 573 } else { 574 memcpy(buffer, (void *)IFIRST(header) + 575 le16_to_cpu(entry->e_value_offs), size); 576 } 577 } 578 error = size; 579 580 cleanup: 581 brelse(iloc.bh); 582 return error; 583 } 584 585 /* 586 * ext4_xattr_get() 587 * 588 * Copy an extended attribute into the buffer 589 * provided, or compute the buffer size required. 590 * Buffer is NULL to compute the size of the buffer required. 591 * 592 * Returns a negative error number on failure, or the number of bytes 593 * used / required on success. 594 */ 595 int 596 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 597 void *buffer, size_t buffer_size) 598 { 599 int error; 600 601 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 602 return -EIO; 603 604 if (strlen(name) > 255) 605 return -ERANGE; 606 607 down_read(&EXT4_I(inode)->xattr_sem); 608 error = ext4_xattr_ibody_get(inode, name_index, name, buffer, 609 buffer_size); 610 if (error == -ENODATA) 611 error = ext4_xattr_block_get(inode, name_index, name, buffer, 612 buffer_size); 613 up_read(&EXT4_I(inode)->xattr_sem); 614 return error; 615 } 616 617 static int 618 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, 619 char *buffer, size_t buffer_size) 620 { 621 size_t rest = buffer_size; 622 623 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 624 const struct xattr_handler *handler = 625 ext4_xattr_handler(entry->e_name_index); 626 627 if (handler && (!handler->list || handler->list(dentry))) { 628 const char *prefix = handler->prefix ?: handler->name; 629 size_t prefix_len = strlen(prefix); 630 size_t size = prefix_len + entry->e_name_len + 1; 631 632 if (buffer) { 633 if (size > rest) 634 return -ERANGE; 635 memcpy(buffer, prefix, prefix_len); 636 buffer += prefix_len; 637 memcpy(buffer, entry->e_name, entry->e_name_len); 638 buffer += entry->e_name_len; 639 *buffer++ = 0; 640 } 641 rest -= size; 642 } 643 } 644 return buffer_size - rest; /* total size */ 645 } 646 647 static int 648 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) 649 { 650 struct inode *inode = d_inode(dentry); 651 struct buffer_head *bh = NULL; 652 int error; 653 654 ea_idebug(inode, "buffer=%p, buffer_size=%ld", 655 buffer, (long)buffer_size); 656 657 error = 0; 658 if (!EXT4_I(inode)->i_file_acl) 659 goto cleanup; 660 ea_idebug(inode, "reading block %llu", 661 (unsigned long long)EXT4_I(inode)->i_file_acl); 662 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 663 error = -EIO; 664 if (!bh) 665 goto cleanup; 666 ea_bdebug(bh, "b_count=%d, refcount=%d", 667 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 668 if (ext4_xattr_check_block(inode, bh)) { 669 EXT4_ERROR_INODE(inode, "bad block %llu", 670 EXT4_I(inode)->i_file_acl); 671 error = -EFSCORRUPTED; 672 goto cleanup; 673 } 674 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); 675 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size); 676 677 cleanup: 678 brelse(bh); 679 680 return error; 681 } 682 683 static int 684 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 685 { 686 struct inode *inode = d_inode(dentry); 687 struct ext4_xattr_ibody_header *header; 688 struct ext4_inode *raw_inode; 689 struct ext4_iloc iloc; 690 void *end; 691 int error; 692 693 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 694 return 0; 695 error = ext4_get_inode_loc(inode, &iloc); 696 if (error) 697 return error; 698 raw_inode = ext4_raw_inode(&iloc); 699 header = IHDR(inode, raw_inode); 700 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 701 error = xattr_check_inode(inode, header, end); 702 if (error) 703 goto cleanup; 704 error = ext4_xattr_list_entries(dentry, IFIRST(header), 705 buffer, buffer_size); 706 707 cleanup: 708 brelse(iloc.bh); 709 return error; 710 } 711 712 /* 713 * Inode operation listxattr() 714 * 715 * d_inode(dentry)->i_rwsem: don't care 716 * 717 * Copy a list of attribute names into the buffer 718 * provided, or compute the buffer size required. 719 * Buffer is NULL to compute the size of the buffer required. 720 * 721 * Returns a negative error number on failure, or the number of bytes 722 * used / required on success. 723 */ 724 ssize_t 725 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 726 { 727 int ret, ret2; 728 729 down_read(&EXT4_I(d_inode(dentry))->xattr_sem); 730 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); 731 if (ret < 0) 732 goto errout; 733 if (buffer) { 734 buffer += ret; 735 buffer_size -= ret; 736 } 737 ret = ext4_xattr_block_list(dentry, buffer, buffer_size); 738 if (ret < 0) 739 goto errout; 740 ret += ret2; 741 errout: 742 up_read(&EXT4_I(d_inode(dentry))->xattr_sem); 743 return ret; 744 } 745 746 /* 747 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is 748 * not set, set it. 749 */ 750 static void ext4_xattr_update_super_block(handle_t *handle, 751 struct super_block *sb) 752 { 753 if (ext4_has_feature_xattr(sb)) 754 return; 755 756 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 757 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { 758 ext4_set_feature_xattr(sb); 759 ext4_handle_dirty_super(handle, sb); 760 } 761 } 762 763 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 764 { 765 struct ext4_iloc iloc = { .bh = NULL }; 766 struct buffer_head *bh = NULL; 767 struct ext4_inode *raw_inode; 768 struct ext4_xattr_ibody_header *header; 769 struct ext4_xattr_entry *entry; 770 qsize_t ea_inode_refs = 0; 771 void *end; 772 int ret; 773 774 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); 775 776 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 777 ret = ext4_get_inode_loc(inode, &iloc); 778 if (ret) 779 goto out; 780 raw_inode = ext4_raw_inode(&iloc); 781 header = IHDR(inode, raw_inode); 782 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 783 ret = xattr_check_inode(inode, header, end); 784 if (ret) 785 goto out; 786 787 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); 788 entry = EXT4_XATTR_NEXT(entry)) 789 if (entry->e_value_inum) 790 ea_inode_refs++; 791 } 792 793 if (EXT4_I(inode)->i_file_acl) { 794 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 795 if (!bh) { 796 ret = -EIO; 797 goto out; 798 } 799 800 if (ext4_xattr_check_block(inode, bh)) { 801 ret = -EFSCORRUPTED; 802 goto out; 803 } 804 805 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 806 entry = EXT4_XATTR_NEXT(entry)) 807 if (entry->e_value_inum) 808 ea_inode_refs++; 809 } 810 *usage = ea_inode_refs + 1; 811 ret = 0; 812 out: 813 brelse(iloc.bh); 814 brelse(bh); 815 return ret; 816 } 817 818 static inline size_t round_up_cluster(struct inode *inode, size_t length) 819 { 820 struct super_block *sb = inode->i_sb; 821 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits + 822 inode->i_blkbits); 823 size_t mask = ~(cluster_size - 1); 824 825 return (length + cluster_size - 1) & mask; 826 } 827 828 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len) 829 { 830 int err; 831 832 err = dquot_alloc_inode(inode); 833 if (err) 834 return err; 835 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len)); 836 if (err) 837 dquot_free_inode(inode); 838 return err; 839 } 840 841 static void ext4_xattr_inode_free_quota(struct inode *inode, size_t len) 842 { 843 dquot_free_space_nodirty(inode, round_up_cluster(inode, len)); 844 dquot_free_inode(inode); 845 } 846 847 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, 848 struct buffer_head *block_bh, size_t value_len, 849 bool is_create) 850 { 851 int credits; 852 int blocks; 853 854 /* 855 * 1) Owner inode update 856 * 2) Ref count update on old xattr block 857 * 3) new xattr block 858 * 4) block bitmap update for new xattr block 859 * 5) group descriptor for new xattr block 860 * 6) block bitmap update for old xattr block 861 * 7) group descriptor for old block 862 * 863 * 6 & 7 can happen if we have two racing threads T_a and T_b 864 * which are each trying to set an xattr on inodes I_a and I_b 865 * which were both initially sharing an xattr block. 866 */ 867 credits = 7; 868 869 /* Quota updates. */ 870 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb); 871 872 /* 873 * In case of inline data, we may push out the data to a block, 874 * so we need to reserve credits for this eventuality 875 */ 876 if (inode && ext4_has_inline_data(inode)) 877 credits += ext4_writepage_trans_blocks(inode) + 1; 878 879 /* We are done if ea_inode feature is not enabled. */ 880 if (!ext4_has_feature_ea_inode(sb)) 881 return credits; 882 883 /* New ea_inode, inode map, block bitmap, group descriptor. */ 884 credits += 4; 885 886 /* Data blocks. */ 887 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 888 889 /* Indirection block or one level of extent tree. */ 890 blocks += 1; 891 892 /* Block bitmap and group descriptor updates for each block. */ 893 credits += blocks * 2; 894 895 /* Blocks themselves. */ 896 credits += blocks; 897 898 if (!is_create) { 899 /* Dereference ea_inode holding old xattr value. 900 * Old ea_inode, inode map, block bitmap, group descriptor. 901 */ 902 credits += 4; 903 904 /* Data blocks for old ea_inode. */ 905 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits; 906 907 /* Indirection block or one level of extent tree for old 908 * ea_inode. 909 */ 910 blocks += 1; 911 912 /* Block bitmap and group descriptor updates for each block. */ 913 credits += blocks * 2; 914 } 915 916 /* We may need to clone the existing xattr block in which case we need 917 * to increment ref counts for existing ea_inodes referenced by it. 918 */ 919 if (block_bh) { 920 struct ext4_xattr_entry *entry = BFIRST(block_bh); 921 922 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) 923 if (entry->e_value_inum) 924 /* Ref count update on ea_inode. */ 925 credits += 1; 926 } 927 return credits; 928 } 929 930 static int ext4_xattr_ensure_credits(handle_t *handle, struct inode *inode, 931 int credits, struct buffer_head *bh, 932 bool dirty, bool block_csum) 933 { 934 int error; 935 936 if (!ext4_handle_valid(handle)) 937 return 0; 938 939 if (handle->h_buffer_credits >= credits) 940 return 0; 941 942 error = ext4_journal_extend(handle, credits - handle->h_buffer_credits); 943 if (!error) 944 return 0; 945 if (error < 0) { 946 ext4_warning(inode->i_sb, "Extend journal (error %d)", error); 947 return error; 948 } 949 950 if (bh && dirty) { 951 if (block_csum) 952 ext4_xattr_block_csum_set(inode, bh); 953 error = ext4_handle_dirty_metadata(handle, NULL, bh); 954 if (error) { 955 ext4_warning(inode->i_sb, "Handle metadata (error %d)", 956 error); 957 return error; 958 } 959 } 960 961 error = ext4_journal_restart(handle, credits); 962 if (error) { 963 ext4_warning(inode->i_sb, "Restart journal (error %d)", error); 964 return error; 965 } 966 967 if (bh) { 968 error = ext4_journal_get_write_access(handle, bh); 969 if (error) { 970 ext4_warning(inode->i_sb, 971 "Get write access failed (error %d)", 972 error); 973 return error; 974 } 975 } 976 return 0; 977 } 978 979 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode, 980 int ref_change) 981 { 982 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode); 983 struct ext4_iloc iloc; 984 s64 ref_count; 985 u32 hash; 986 int ret; 987 988 inode_lock(ea_inode); 989 990 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc); 991 if (ret) { 992 iloc.bh = NULL; 993 goto out; 994 } 995 996 ref_count = ext4_xattr_inode_get_ref(ea_inode); 997 ref_count += ref_change; 998 ext4_xattr_inode_set_ref(ea_inode, ref_count); 999 1000 if (ref_change > 0) { 1001 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld", 1002 ea_inode->i_ino, ref_count); 1003 1004 if (ref_count == 1) { 1005 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u", 1006 ea_inode->i_ino, ea_inode->i_nlink); 1007 1008 set_nlink(ea_inode, 1); 1009 ext4_orphan_del(handle, ea_inode); 1010 1011 if (ea_inode_cache) { 1012 hash = ext4_xattr_inode_get_hash(ea_inode); 1013 mb_cache_entry_create(ea_inode_cache, 1014 GFP_NOFS, hash, 1015 ea_inode->i_ino, 1016 true /* reusable */); 1017 } 1018 } 1019 } else { 1020 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld", 1021 ea_inode->i_ino, ref_count); 1022 1023 if (ref_count == 0) { 1024 WARN_ONCE(ea_inode->i_nlink != 1, 1025 "EA inode %lu i_nlink=%u", 1026 ea_inode->i_ino, ea_inode->i_nlink); 1027 1028 clear_nlink(ea_inode); 1029 ext4_orphan_add(handle, ea_inode); 1030 1031 if (ea_inode_cache) { 1032 hash = ext4_xattr_inode_get_hash(ea_inode); 1033 mb_cache_entry_delete(ea_inode_cache, hash, 1034 ea_inode->i_ino); 1035 } 1036 } 1037 } 1038 1039 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc); 1040 iloc.bh = NULL; 1041 if (ret) 1042 ext4_warning_inode(ea_inode, 1043 "ext4_mark_iloc_dirty() failed ret=%d", ret); 1044 out: 1045 brelse(iloc.bh); 1046 inode_unlock(ea_inode); 1047 return ret; 1048 } 1049 1050 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode) 1051 { 1052 return ext4_xattr_inode_update_ref(handle, ea_inode, 1); 1053 } 1054 1055 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode) 1056 { 1057 return ext4_xattr_inode_update_ref(handle, ea_inode, -1); 1058 } 1059 1060 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent, 1061 struct ext4_xattr_entry *first) 1062 { 1063 struct inode *ea_inode; 1064 struct ext4_xattr_entry *entry; 1065 struct ext4_xattr_entry *failed_entry; 1066 unsigned int ea_ino; 1067 int err, saved_err; 1068 1069 for (entry = first; !IS_LAST_ENTRY(entry); 1070 entry = EXT4_XATTR_NEXT(entry)) { 1071 if (!entry->e_value_inum) 1072 continue; 1073 ea_ino = le32_to_cpu(entry->e_value_inum); 1074 err = ext4_xattr_inode_iget(parent, ea_ino, &ea_inode); 1075 if (err) 1076 goto cleanup; 1077 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1078 if (err) { 1079 ext4_warning_inode(ea_inode, "inc ref error %d", err); 1080 iput(ea_inode); 1081 goto cleanup; 1082 } 1083 iput(ea_inode); 1084 } 1085 return 0; 1086 1087 cleanup: 1088 saved_err = err; 1089 failed_entry = entry; 1090 1091 for (entry = first; entry != failed_entry; 1092 entry = EXT4_XATTR_NEXT(entry)) { 1093 if (!entry->e_value_inum) 1094 continue; 1095 ea_ino = le32_to_cpu(entry->e_value_inum); 1096 err = ext4_xattr_inode_iget(parent, ea_ino, &ea_inode); 1097 if (err) { 1098 ext4_warning(parent->i_sb, 1099 "cleanup ea_ino %u iget error %d", ea_ino, 1100 err); 1101 continue; 1102 } 1103 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1104 if (err) 1105 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", 1106 err); 1107 iput(ea_inode); 1108 } 1109 return saved_err; 1110 } 1111 1112 static void 1113 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent, 1114 struct buffer_head *bh, 1115 struct ext4_xattr_entry *first, bool block_csum, 1116 struct ext4_xattr_inode_array **ea_inode_array, 1117 int extra_credits, bool skip_quota) 1118 { 1119 struct inode *ea_inode; 1120 struct ext4_xattr_entry *entry; 1121 bool dirty = false; 1122 unsigned int ea_ino; 1123 int err; 1124 int credits; 1125 1126 /* One credit for dec ref on ea_inode, one for orphan list addition, */ 1127 credits = 2 + extra_credits; 1128 1129 for (entry = first; !IS_LAST_ENTRY(entry); 1130 entry = EXT4_XATTR_NEXT(entry)) { 1131 if (!entry->e_value_inum) 1132 continue; 1133 ea_ino = le32_to_cpu(entry->e_value_inum); 1134 err = ext4_xattr_inode_iget(parent, ea_ino, &ea_inode); 1135 if (err) 1136 continue; 1137 1138 err = ext4_expand_inode_array(ea_inode_array, ea_inode); 1139 if (err) { 1140 ext4_warning_inode(ea_inode, 1141 "Expand inode array err=%d", err); 1142 iput(ea_inode); 1143 continue; 1144 } 1145 1146 err = ext4_xattr_ensure_credits(handle, parent, credits, bh, 1147 dirty, block_csum); 1148 if (err) { 1149 ext4_warning_inode(ea_inode, "Ensure credits err=%d", 1150 err); 1151 continue; 1152 } 1153 1154 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1155 if (err) { 1156 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d", 1157 err); 1158 continue; 1159 } 1160 1161 if (!skip_quota) 1162 ext4_xattr_inode_free_quota(parent, 1163 le32_to_cpu(entry->e_value_size)); 1164 1165 /* 1166 * Forget about ea_inode within the same transaction that 1167 * decrements the ref count. This avoids duplicate decrements in 1168 * case the rest of the work spills over to subsequent 1169 * transactions. 1170 */ 1171 entry->e_value_inum = 0; 1172 entry->e_value_size = 0; 1173 1174 dirty = true; 1175 } 1176 1177 if (dirty) { 1178 /* 1179 * Note that we are deliberately skipping csum calculation for 1180 * the final update because we do not expect any journal 1181 * restarts until xattr block is freed. 1182 */ 1183 1184 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1185 if (err) 1186 ext4_warning_inode(parent, 1187 "handle dirty metadata err=%d", err); 1188 } 1189 } 1190 1191 /* 1192 * Release the xattr block BH: If the reference count is > 1, decrement it; 1193 * otherwise free the block. 1194 */ 1195 static void 1196 ext4_xattr_release_block(handle_t *handle, struct inode *inode, 1197 struct buffer_head *bh, 1198 struct ext4_xattr_inode_array **ea_inode_array, 1199 int extra_credits) 1200 { 1201 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1202 u32 hash, ref; 1203 int error = 0; 1204 1205 BUFFER_TRACE(bh, "get_write_access"); 1206 error = ext4_journal_get_write_access(handle, bh); 1207 if (error) 1208 goto out; 1209 1210 lock_buffer(bh); 1211 hash = le32_to_cpu(BHDR(bh)->h_hash); 1212 ref = le32_to_cpu(BHDR(bh)->h_refcount); 1213 if (ref == 1) { 1214 ea_bdebug(bh, "refcount now=0; freeing"); 1215 /* 1216 * This must happen under buffer lock for 1217 * ext4_xattr_block_set() to reliably detect freed block 1218 */ 1219 if (ea_block_cache) 1220 mb_cache_entry_delete(ea_block_cache, hash, 1221 bh->b_blocknr); 1222 get_bh(bh); 1223 unlock_buffer(bh); 1224 1225 if (ext4_has_feature_ea_inode(inode->i_sb)) 1226 ext4_xattr_inode_dec_ref_all(handle, inode, bh, 1227 BFIRST(bh), 1228 true /* block_csum */, 1229 ea_inode_array, 1230 extra_credits, 1231 true /* skip_quota */); 1232 ext4_free_blocks(handle, inode, bh, 0, 1, 1233 EXT4_FREE_BLOCKS_METADATA | 1234 EXT4_FREE_BLOCKS_FORGET); 1235 } else { 1236 ref--; 1237 BHDR(bh)->h_refcount = cpu_to_le32(ref); 1238 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) { 1239 struct mb_cache_entry *ce; 1240 1241 if (ea_block_cache) { 1242 ce = mb_cache_entry_get(ea_block_cache, hash, 1243 bh->b_blocknr); 1244 if (ce) { 1245 ce->e_reusable = 1; 1246 mb_cache_entry_put(ea_block_cache, ce); 1247 } 1248 } 1249 } 1250 1251 ext4_xattr_block_csum_set(inode, bh); 1252 /* 1253 * Beware of this ugliness: Releasing of xattr block references 1254 * from different inodes can race and so we have to protect 1255 * from a race where someone else frees the block (and releases 1256 * its journal_head) before we are done dirtying the buffer. In 1257 * nojournal mode this race is harmless and we actually cannot 1258 * call ext4_handle_dirty_metadata() with locked buffer as 1259 * that function can call sync_dirty_buffer() so for that case 1260 * we handle the dirtying after unlocking the buffer. 1261 */ 1262 if (ext4_handle_valid(handle)) 1263 error = ext4_handle_dirty_metadata(handle, inode, bh); 1264 unlock_buffer(bh); 1265 if (!ext4_handle_valid(handle)) 1266 error = ext4_handle_dirty_metadata(handle, inode, bh); 1267 if (IS_SYNC(inode)) 1268 ext4_handle_sync(handle); 1269 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); 1270 ea_bdebug(bh, "refcount now=%d; releasing", 1271 le32_to_cpu(BHDR(bh)->h_refcount)); 1272 } 1273 out: 1274 ext4_std_error(inode->i_sb, error); 1275 return; 1276 } 1277 1278 /* 1279 * Find the available free space for EAs. This also returns the total number of 1280 * bytes used by EA entries. 1281 */ 1282 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, 1283 size_t *min_offs, void *base, int *total) 1284 { 1285 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1286 if (!last->e_value_inum && last->e_value_size) { 1287 size_t offs = le16_to_cpu(last->e_value_offs); 1288 if (offs < *min_offs) 1289 *min_offs = offs; 1290 } 1291 if (total) 1292 *total += EXT4_XATTR_LEN(last->e_name_len); 1293 } 1294 return (*min_offs - ((void *)last - base) - sizeof(__u32)); 1295 } 1296 1297 /* 1298 * Write the value of the EA in an inode. 1299 */ 1300 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode, 1301 const void *buf, int bufsize) 1302 { 1303 struct buffer_head *bh = NULL; 1304 unsigned long block = 0; 1305 int blocksize = ea_inode->i_sb->s_blocksize; 1306 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits; 1307 int csize, wsize = 0; 1308 int ret = 0; 1309 int retries = 0; 1310 1311 retry: 1312 while (ret >= 0 && ret < max_blocks) { 1313 struct ext4_map_blocks map; 1314 map.m_lblk = block += ret; 1315 map.m_len = max_blocks -= ret; 1316 1317 ret = ext4_map_blocks(handle, ea_inode, &map, 1318 EXT4_GET_BLOCKS_CREATE); 1319 if (ret <= 0) { 1320 ext4_mark_inode_dirty(handle, ea_inode); 1321 if (ret == -ENOSPC && 1322 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) { 1323 ret = 0; 1324 goto retry; 1325 } 1326 break; 1327 } 1328 } 1329 1330 if (ret < 0) 1331 return ret; 1332 1333 block = 0; 1334 while (wsize < bufsize) { 1335 if (bh != NULL) 1336 brelse(bh); 1337 csize = (bufsize - wsize) > blocksize ? blocksize : 1338 bufsize - wsize; 1339 bh = ext4_getblk(handle, ea_inode, block, 0); 1340 if (IS_ERR(bh)) 1341 return PTR_ERR(bh); 1342 ret = ext4_journal_get_write_access(handle, bh); 1343 if (ret) 1344 goto out; 1345 1346 memcpy(bh->b_data, buf, csize); 1347 set_buffer_uptodate(bh); 1348 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1349 1350 buf += csize; 1351 wsize += csize; 1352 block += 1; 1353 } 1354 1355 inode_lock(ea_inode); 1356 i_size_write(ea_inode, wsize); 1357 ext4_update_i_disksize(ea_inode, wsize); 1358 inode_unlock(ea_inode); 1359 1360 ext4_mark_inode_dirty(handle, ea_inode); 1361 1362 out: 1363 brelse(bh); 1364 1365 return ret; 1366 } 1367 1368 /* 1369 * Create an inode to store the value of a large EA. 1370 */ 1371 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1372 struct inode *inode, u32 hash) 1373 { 1374 struct inode *ea_inode = NULL; 1375 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1376 int err; 1377 1378 /* 1379 * Let the next inode be the goal, so we try and allocate the EA inode 1380 * in the same group, or nearby one. 1381 */ 1382 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1383 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1384 EXT4_EA_INODE_FL); 1385 if (!IS_ERR(ea_inode)) { 1386 ea_inode->i_op = &ext4_file_inode_operations; 1387 ea_inode->i_fop = &ext4_file_operations; 1388 ext4_set_aops(ea_inode); 1389 ext4_xattr_inode_set_class(ea_inode); 1390 unlock_new_inode(ea_inode); 1391 ext4_xattr_inode_set_ref(ea_inode, 1); 1392 ext4_xattr_inode_set_hash(ea_inode, hash); 1393 err = ext4_mark_inode_dirty(handle, ea_inode); 1394 if (!err) 1395 err = ext4_inode_attach_jinode(ea_inode); 1396 if (err) { 1397 iput(ea_inode); 1398 return ERR_PTR(err); 1399 } 1400 1401 /* 1402 * Xattr inodes are shared therefore quota charging is performed 1403 * at a higher level. 1404 */ 1405 dquot_free_inode(ea_inode); 1406 dquot_drop(ea_inode); 1407 inode_lock(ea_inode); 1408 ea_inode->i_flags |= S_NOQUOTA; 1409 inode_unlock(ea_inode); 1410 } 1411 1412 return ea_inode; 1413 } 1414 1415 static struct inode * 1416 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1417 size_t value_len, u32 hash) 1418 { 1419 struct inode *ea_inode; 1420 struct mb_cache_entry *ce; 1421 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1422 void *ea_data; 1423 1424 if (!ea_inode_cache) 1425 return NULL; 1426 1427 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1428 if (!ce) 1429 return NULL; 1430 1431 ea_data = ext4_kvmalloc(value_len, GFP_NOFS); 1432 if (!ea_data) { 1433 mb_cache_entry_put(ea_inode_cache, ce); 1434 return NULL; 1435 } 1436 1437 while (ce) { 1438 ea_inode = ext4_iget(inode->i_sb, ce->e_value); 1439 if (!IS_ERR(ea_inode) && 1440 !is_bad_inode(ea_inode) && 1441 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1442 i_size_read(ea_inode) == value_len && 1443 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1444 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1445 value_len) && 1446 !memcmp(value, ea_data, value_len)) { 1447 mb_cache_entry_touch(ea_inode_cache, ce); 1448 mb_cache_entry_put(ea_inode_cache, ce); 1449 kvfree(ea_data); 1450 return ea_inode; 1451 } 1452 1453 if (!IS_ERR(ea_inode)) 1454 iput(ea_inode); 1455 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1456 } 1457 kvfree(ea_data); 1458 return NULL; 1459 } 1460 1461 /* 1462 * Add value of the EA in an inode. 1463 */ 1464 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1465 const void *value, size_t value_len, 1466 struct inode **ret_inode) 1467 { 1468 struct inode *ea_inode; 1469 u32 hash; 1470 int err; 1471 1472 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1473 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1474 if (ea_inode) { 1475 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1476 if (err) { 1477 iput(ea_inode); 1478 return err; 1479 } 1480 1481 *ret_inode = ea_inode; 1482 return 0; 1483 } 1484 1485 /* Create an inode for the EA value */ 1486 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1487 if (IS_ERR(ea_inode)) 1488 return PTR_ERR(ea_inode); 1489 1490 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1491 if (err) { 1492 ext4_xattr_inode_dec_ref(handle, ea_inode); 1493 iput(ea_inode); 1494 return err; 1495 } 1496 1497 if (EA_INODE_CACHE(inode)) 1498 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1499 ea_inode->i_ino, true /* reusable */); 1500 1501 *ret_inode = ea_inode; 1502 return 0; 1503 } 1504 1505 /* 1506 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1507 * feature is enabled. 1508 */ 1509 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1510 1511 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1512 struct ext4_xattr_search *s, 1513 handle_t *handle, struct inode *inode, 1514 bool is_block) 1515 { 1516 struct ext4_xattr_entry *last; 1517 struct ext4_xattr_entry *here = s->here; 1518 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1519 int in_inode = i->in_inode; 1520 struct inode *old_ea_inode = NULL; 1521 struct inode *new_ea_inode = NULL; 1522 size_t old_size, new_size; 1523 int ret; 1524 1525 /* Space used by old and new values. */ 1526 old_size = (!s->not_found && !here->e_value_inum) ? 1527 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1528 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1529 1530 /* 1531 * Optimization for the simple case when old and new values have the 1532 * same padded sizes. Not applicable if external inodes are involved. 1533 */ 1534 if (new_size && new_size == old_size) { 1535 size_t offs = le16_to_cpu(here->e_value_offs); 1536 void *val = s->base + offs; 1537 1538 here->e_value_size = cpu_to_le32(i->value_len); 1539 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1540 memset(val, 0, new_size); 1541 } else { 1542 memcpy(val, i->value, i->value_len); 1543 /* Clear padding bytes. */ 1544 memset(val + i->value_len, 0, new_size - i->value_len); 1545 } 1546 return 0; 1547 } 1548 1549 /* Compute min_offs and last. */ 1550 last = s->first; 1551 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1552 if (!last->e_value_inum && last->e_value_size) { 1553 size_t offs = le16_to_cpu(last->e_value_offs); 1554 if (offs < min_offs) 1555 min_offs = offs; 1556 } 1557 } 1558 1559 /* Check whether we have enough space. */ 1560 if (i->value) { 1561 size_t free; 1562 1563 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1564 if (!s->not_found) 1565 free += EXT4_XATTR_LEN(name_len) + old_size; 1566 1567 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1568 ret = -ENOSPC; 1569 goto out; 1570 } 1571 1572 /* 1573 * If storing the value in an external inode is an option, 1574 * reserve space for xattr entries/names in the external 1575 * attribute block so that a long value does not occupy the 1576 * whole space and prevent futher entries being added. 1577 */ 1578 if (ext4_has_feature_ea_inode(inode->i_sb) && 1579 new_size && is_block && 1580 (min_offs + old_size - new_size) < 1581 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1582 ret = -ENOSPC; 1583 goto out; 1584 } 1585 } 1586 1587 /* 1588 * Getting access to old and new ea inodes is subject to failures. 1589 * Finish that work before doing any modifications to the xattr data. 1590 */ 1591 if (!s->not_found && here->e_value_inum) { 1592 ret = ext4_xattr_inode_iget(inode, 1593 le32_to_cpu(here->e_value_inum), 1594 &old_ea_inode); 1595 if (ret) { 1596 old_ea_inode = NULL; 1597 goto out; 1598 } 1599 } 1600 if (i->value && in_inode) { 1601 WARN_ON_ONCE(!i->value_len); 1602 1603 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1604 if (ret) 1605 goto out; 1606 1607 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1608 i->value_len, 1609 &new_ea_inode); 1610 if (ret) { 1611 new_ea_inode = NULL; 1612 ext4_xattr_inode_free_quota(inode, i->value_len); 1613 goto out; 1614 } 1615 } 1616 1617 if (old_ea_inode) { 1618 /* We are ready to release ref count on the old_ea_inode. */ 1619 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1620 if (ret) { 1621 /* Release newly required ref count on new_ea_inode. */ 1622 if (new_ea_inode) { 1623 int err; 1624 1625 err = ext4_xattr_inode_dec_ref(handle, 1626 new_ea_inode); 1627 if (err) 1628 ext4_warning_inode(new_ea_inode, 1629 "dec ref new_ea_inode err=%d", 1630 err); 1631 ext4_xattr_inode_free_quota(inode, 1632 i->value_len); 1633 } 1634 goto out; 1635 } 1636 1637 ext4_xattr_inode_free_quota(inode, 1638 le32_to_cpu(here->e_value_size)); 1639 } 1640 1641 /* No failures allowed past this point. */ 1642 1643 if (!s->not_found && here->e_value_offs) { 1644 /* Remove the old value. */ 1645 void *first_val = s->base + min_offs; 1646 size_t offs = le16_to_cpu(here->e_value_offs); 1647 void *val = s->base + offs; 1648 1649 memmove(first_val + old_size, first_val, val - first_val); 1650 memset(first_val, 0, old_size); 1651 min_offs += old_size; 1652 1653 /* Adjust all value offsets. */ 1654 last = s->first; 1655 while (!IS_LAST_ENTRY(last)) { 1656 size_t o = le16_to_cpu(last->e_value_offs); 1657 1658 if (!last->e_value_inum && 1659 last->e_value_size && o < offs) 1660 last->e_value_offs = cpu_to_le16(o + old_size); 1661 last = EXT4_XATTR_NEXT(last); 1662 } 1663 } 1664 1665 if (!i->value) { 1666 /* Remove old name. */ 1667 size_t size = EXT4_XATTR_LEN(name_len); 1668 1669 last = ENTRY((void *)last - size); 1670 memmove(here, (void *)here + size, 1671 (void *)last - (void *)here + sizeof(__u32)); 1672 memset(last, 0, size); 1673 } else if (s->not_found) { 1674 /* Insert new name. */ 1675 size_t size = EXT4_XATTR_LEN(name_len); 1676 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1677 1678 memmove((void *)here + size, here, rest); 1679 memset(here, 0, size); 1680 here->e_name_index = i->name_index; 1681 here->e_name_len = name_len; 1682 memcpy(here->e_name, i->name, name_len); 1683 } else { 1684 /* This is an update, reset value info. */ 1685 here->e_value_inum = 0; 1686 here->e_value_offs = 0; 1687 here->e_value_size = 0; 1688 } 1689 1690 if (i->value) { 1691 /* Insert new value. */ 1692 if (in_inode) { 1693 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1694 } else if (i->value_len) { 1695 void *val = s->base + min_offs - new_size; 1696 1697 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1698 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1699 memset(val, 0, new_size); 1700 } else { 1701 memcpy(val, i->value, i->value_len); 1702 /* Clear padding bytes. */ 1703 memset(val + i->value_len, 0, 1704 new_size - i->value_len); 1705 } 1706 } 1707 here->e_value_size = cpu_to_le32(i->value_len); 1708 } 1709 1710 if (i->value) { 1711 __le32 hash = 0; 1712 1713 /* Entry hash calculation. */ 1714 if (in_inode) { 1715 __le32 crc32c_hash; 1716 1717 /* 1718 * Feed crc32c hash instead of the raw value for entry 1719 * hash calculation. This is to avoid walking 1720 * potentially long value buffer again. 1721 */ 1722 crc32c_hash = cpu_to_le32( 1723 ext4_xattr_inode_get_hash(new_ea_inode)); 1724 hash = ext4_xattr_hash_entry(here->e_name, 1725 here->e_name_len, 1726 &crc32c_hash, 1); 1727 } else if (is_block) { 1728 __le32 *value = s->base + min_offs - new_size; 1729 1730 hash = ext4_xattr_hash_entry(here->e_name, 1731 here->e_name_len, value, 1732 new_size >> 2); 1733 } 1734 here->e_hash = hash; 1735 } 1736 1737 if (is_block) 1738 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1739 1740 ret = 0; 1741 out: 1742 iput(old_ea_inode); 1743 iput(new_ea_inode); 1744 return ret; 1745 } 1746 1747 struct ext4_xattr_block_find { 1748 struct ext4_xattr_search s; 1749 struct buffer_head *bh; 1750 }; 1751 1752 static int 1753 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1754 struct ext4_xattr_block_find *bs) 1755 { 1756 struct super_block *sb = inode->i_sb; 1757 int error; 1758 1759 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1760 i->name_index, i->name, i->value, (long)i->value_len); 1761 1762 if (EXT4_I(inode)->i_file_acl) { 1763 /* The inode already has an extended attribute block. */ 1764 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl); 1765 error = -EIO; 1766 if (!bs->bh) 1767 goto cleanup; 1768 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1769 atomic_read(&(bs->bh->b_count)), 1770 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1771 if (ext4_xattr_check_block(inode, bs->bh)) { 1772 EXT4_ERROR_INODE(inode, "bad block %llu", 1773 EXT4_I(inode)->i_file_acl); 1774 error = -EFSCORRUPTED; 1775 goto cleanup; 1776 } 1777 /* Find the named attribute. */ 1778 bs->s.base = BHDR(bs->bh); 1779 bs->s.first = BFIRST(bs->bh); 1780 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1781 bs->s.here = bs->s.first; 1782 error = ext4_xattr_find_entry(&bs->s.here, i->name_index, 1783 i->name, 1); 1784 if (error && error != -ENODATA) 1785 goto cleanup; 1786 bs->s.not_found = error; 1787 } 1788 error = 0; 1789 1790 cleanup: 1791 return error; 1792 } 1793 1794 static int 1795 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1796 struct ext4_xattr_info *i, 1797 struct ext4_xattr_block_find *bs) 1798 { 1799 struct super_block *sb = inode->i_sb; 1800 struct buffer_head *new_bh = NULL; 1801 struct ext4_xattr_search s_copy = bs->s; 1802 struct ext4_xattr_search *s = &s_copy; 1803 struct mb_cache_entry *ce = NULL; 1804 int error = 0; 1805 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1806 struct inode *ea_inode = NULL; 1807 size_t old_ea_inode_size = 0; 1808 1809 #define header(x) ((struct ext4_xattr_header *)(x)) 1810 1811 if (s->base) { 1812 BUFFER_TRACE(bs->bh, "get_write_access"); 1813 error = ext4_journal_get_write_access(handle, bs->bh); 1814 if (error) 1815 goto cleanup; 1816 lock_buffer(bs->bh); 1817 1818 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1819 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1820 1821 /* 1822 * This must happen under buffer lock for 1823 * ext4_xattr_block_set() to reliably detect modified 1824 * block 1825 */ 1826 if (ea_block_cache) 1827 mb_cache_entry_delete(ea_block_cache, hash, 1828 bs->bh->b_blocknr); 1829 ea_bdebug(bs->bh, "modifying in-place"); 1830 error = ext4_xattr_set_entry(i, s, handle, inode, 1831 true /* is_block */); 1832 ext4_xattr_block_csum_set(inode, bs->bh); 1833 unlock_buffer(bs->bh); 1834 if (error == -EFSCORRUPTED) 1835 goto bad_block; 1836 if (!error) 1837 error = ext4_handle_dirty_metadata(handle, 1838 inode, 1839 bs->bh); 1840 if (error) 1841 goto cleanup; 1842 goto inserted; 1843 } else { 1844 int offset = (char *)s->here - bs->bh->b_data; 1845 1846 unlock_buffer(bs->bh); 1847 ea_bdebug(bs->bh, "cloning"); 1848 s->base = kmalloc(bs->bh->b_size, GFP_NOFS); 1849 error = -ENOMEM; 1850 if (s->base == NULL) 1851 goto cleanup; 1852 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); 1853 s->first = ENTRY(header(s->base)+1); 1854 header(s->base)->h_refcount = cpu_to_le32(1); 1855 s->here = ENTRY(s->base + offset); 1856 s->end = s->base + bs->bh->b_size; 1857 1858 /* 1859 * If existing entry points to an xattr inode, we need 1860 * to prevent ext4_xattr_set_entry() from decrementing 1861 * ref count on it because the reference belongs to the 1862 * original block. In this case, make the entry look 1863 * like it has an empty value. 1864 */ 1865 if (!s->not_found && s->here->e_value_inum) { 1866 /* 1867 * Defer quota free call for previous inode 1868 * until success is guaranteed. 1869 */ 1870 old_ea_inode_size = le32_to_cpu( 1871 s->here->e_value_size); 1872 s->here->e_value_inum = 0; 1873 s->here->e_value_size = 0; 1874 } 1875 } 1876 } else { 1877 /* Allocate a buffer where we construct the new block. */ 1878 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1879 /* assert(header == s->base) */ 1880 error = -ENOMEM; 1881 if (s->base == NULL) 1882 goto cleanup; 1883 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1884 header(s->base)->h_blocks = cpu_to_le32(1); 1885 header(s->base)->h_refcount = cpu_to_le32(1); 1886 s->first = ENTRY(header(s->base)+1); 1887 s->here = ENTRY(header(s->base)+1); 1888 s->end = s->base + sb->s_blocksize; 1889 } 1890 1891 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1892 if (error == -EFSCORRUPTED) 1893 goto bad_block; 1894 if (error) 1895 goto cleanup; 1896 1897 if (i->value && s->here->e_value_inum) { 1898 unsigned int ea_ino; 1899 1900 /* 1901 * A ref count on ea_inode has been taken as part of the call to 1902 * ext4_xattr_set_entry() above. We would like to drop this 1903 * extra ref but we have to wait until the xattr block is 1904 * initialized and has its own ref count on the ea_inode. 1905 */ 1906 ea_ino = le32_to_cpu(s->here->e_value_inum); 1907 error = ext4_xattr_inode_iget(inode, ea_ino, &ea_inode); 1908 if (error) { 1909 ea_inode = NULL; 1910 goto cleanup; 1911 } 1912 } 1913 1914 inserted: 1915 if (!IS_LAST_ENTRY(s->first)) { 1916 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 1917 &ce); 1918 if (new_bh) { 1919 /* We found an identical block in the cache. */ 1920 if (new_bh == bs->bh) 1921 ea_bdebug(new_bh, "keeping"); 1922 else { 1923 u32 ref; 1924 1925 WARN_ON_ONCE(dquot_initialize_needed(inode)); 1926 1927 /* The old block is released after updating 1928 the inode. */ 1929 error = dquot_alloc_block(inode, 1930 EXT4_C2B(EXT4_SB(sb), 1)); 1931 if (error) 1932 goto cleanup; 1933 BUFFER_TRACE(new_bh, "get_write_access"); 1934 error = ext4_journal_get_write_access(handle, 1935 new_bh); 1936 if (error) 1937 goto cleanup_dquot; 1938 lock_buffer(new_bh); 1939 /* 1940 * We have to be careful about races with 1941 * freeing, rehashing or adding references to 1942 * xattr block. Once we hold buffer lock xattr 1943 * block's state is stable so we can check 1944 * whether the block got freed / rehashed or 1945 * not. Since we unhash mbcache entry under 1946 * buffer lock when freeing / rehashing xattr 1947 * block, checking whether entry is still 1948 * hashed is reliable. Same rules hold for 1949 * e_reusable handling. 1950 */ 1951 if (hlist_bl_unhashed(&ce->e_hash_list) || 1952 !ce->e_reusable) { 1953 /* 1954 * Undo everything and check mbcache 1955 * again. 1956 */ 1957 unlock_buffer(new_bh); 1958 dquot_free_block(inode, 1959 EXT4_C2B(EXT4_SB(sb), 1960 1)); 1961 brelse(new_bh); 1962 mb_cache_entry_put(ea_block_cache, ce); 1963 ce = NULL; 1964 new_bh = NULL; 1965 goto inserted; 1966 } 1967 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 1968 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 1969 if (ref >= EXT4_XATTR_REFCOUNT_MAX) 1970 ce->e_reusable = 0; 1971 ea_bdebug(new_bh, "reusing; refcount now=%d", 1972 ref); 1973 ext4_xattr_block_csum_set(inode, new_bh); 1974 unlock_buffer(new_bh); 1975 error = ext4_handle_dirty_metadata(handle, 1976 inode, 1977 new_bh); 1978 if (error) 1979 goto cleanup_dquot; 1980 } 1981 mb_cache_entry_touch(ea_block_cache, ce); 1982 mb_cache_entry_put(ea_block_cache, ce); 1983 ce = NULL; 1984 } else if (bs->bh && s->base == bs->bh->b_data) { 1985 /* We were modifying this block in-place. */ 1986 ea_bdebug(bs->bh, "keeping this block"); 1987 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 1988 new_bh = bs->bh; 1989 get_bh(new_bh); 1990 } else { 1991 /* We need to allocate a new block */ 1992 ext4_fsblk_t goal, block; 1993 1994 WARN_ON_ONCE(dquot_initialize_needed(inode)); 1995 1996 goal = ext4_group_first_block_no(sb, 1997 EXT4_I(inode)->i_block_group); 1998 1999 /* non-extent files can't have physical blocks past 2^32 */ 2000 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2001 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; 2002 2003 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2004 NULL, &error); 2005 if (error) 2006 goto cleanup; 2007 2008 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2009 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); 2010 2011 ea_idebug(inode, "creating block %llu", 2012 (unsigned long long)block); 2013 2014 new_bh = sb_getblk(sb, block); 2015 if (unlikely(!new_bh)) { 2016 error = -ENOMEM; 2017 getblk_failed: 2018 ext4_free_blocks(handle, inode, NULL, block, 1, 2019 EXT4_FREE_BLOCKS_METADATA); 2020 goto cleanup; 2021 } 2022 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2023 ENTRY(header(s->base)+1)); 2024 if (error) 2025 goto getblk_failed; 2026 if (ea_inode) { 2027 /* Drop the extra ref on ea_inode. */ 2028 error = ext4_xattr_inode_dec_ref(handle, 2029 ea_inode); 2030 if (error) 2031 ext4_warning_inode(ea_inode, 2032 "dec ref error=%d", 2033 error); 2034 iput(ea_inode); 2035 ea_inode = NULL; 2036 } 2037 2038 lock_buffer(new_bh); 2039 error = ext4_journal_get_create_access(handle, new_bh); 2040 if (error) { 2041 unlock_buffer(new_bh); 2042 error = -EIO; 2043 goto getblk_failed; 2044 } 2045 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2046 ext4_xattr_block_csum_set(inode, new_bh); 2047 set_buffer_uptodate(new_bh); 2048 unlock_buffer(new_bh); 2049 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2050 error = ext4_handle_dirty_metadata(handle, inode, 2051 new_bh); 2052 if (error) 2053 goto cleanup; 2054 } 2055 } 2056 2057 if (old_ea_inode_size) 2058 ext4_xattr_inode_free_quota(inode, old_ea_inode_size); 2059 2060 /* Update the inode. */ 2061 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2062 2063 /* Drop the previous xattr block. */ 2064 if (bs->bh && bs->bh != new_bh) { 2065 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2066 2067 ext4_xattr_release_block(handle, inode, bs->bh, 2068 &ea_inode_array, 2069 0 /* extra_credits */); 2070 ext4_xattr_inode_array_free(ea_inode_array); 2071 } 2072 error = 0; 2073 2074 cleanup: 2075 if (ea_inode) { 2076 int error2; 2077 2078 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2079 if (error2) 2080 ext4_warning_inode(ea_inode, "dec ref error=%d", 2081 error2); 2082 2083 /* If there was an error, revert the quota charge. */ 2084 if (error) 2085 ext4_xattr_inode_free_quota(inode, 2086 i_size_read(ea_inode)); 2087 iput(ea_inode); 2088 } 2089 if (ce) 2090 mb_cache_entry_put(ea_block_cache, ce); 2091 brelse(new_bh); 2092 if (!(bs->bh && s->base == bs->bh->b_data)) 2093 kfree(s->base); 2094 2095 return error; 2096 2097 cleanup_dquot: 2098 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2099 goto cleanup; 2100 2101 bad_block: 2102 EXT4_ERROR_INODE(inode, "bad block %llu", 2103 EXT4_I(inode)->i_file_acl); 2104 goto cleanup; 2105 2106 #undef header 2107 } 2108 2109 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2110 struct ext4_xattr_ibody_find *is) 2111 { 2112 struct ext4_xattr_ibody_header *header; 2113 struct ext4_inode *raw_inode; 2114 int error; 2115 2116 if (EXT4_I(inode)->i_extra_isize == 0) 2117 return 0; 2118 raw_inode = ext4_raw_inode(&is->iloc); 2119 header = IHDR(inode, raw_inode); 2120 is->s.base = is->s.first = IFIRST(header); 2121 is->s.here = is->s.first; 2122 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2123 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2124 error = xattr_check_inode(inode, header, is->s.end); 2125 if (error) 2126 return error; 2127 /* Find the named attribute. */ 2128 error = ext4_xattr_find_entry(&is->s.here, i->name_index, 2129 i->name, 0); 2130 if (error && error != -ENODATA) 2131 return error; 2132 is->s.not_found = error; 2133 } 2134 return 0; 2135 } 2136 2137 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 2138 struct ext4_xattr_info *i, 2139 struct ext4_xattr_ibody_find *is) 2140 { 2141 struct ext4_xattr_ibody_header *header; 2142 struct ext4_xattr_search *s = &is->s; 2143 int error; 2144 2145 if (EXT4_I(inode)->i_extra_isize == 0) 2146 return -ENOSPC; 2147 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2148 if (error) { 2149 if (error == -ENOSPC && 2150 ext4_has_inline_data(inode)) { 2151 error = ext4_try_to_evict_inline_data(handle, inode, 2152 EXT4_XATTR_LEN(strlen(i->name) + 2153 EXT4_XATTR_SIZE(i->value_len))); 2154 if (error) 2155 return error; 2156 error = ext4_xattr_ibody_find(inode, i, is); 2157 if (error) 2158 return error; 2159 error = ext4_xattr_set_entry(i, s, handle, inode, 2160 false /* is_block */); 2161 } 2162 if (error) 2163 return error; 2164 } 2165 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2166 if (!IS_LAST_ENTRY(s->first)) { 2167 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2168 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2169 } else { 2170 header->h_magic = cpu_to_le32(0); 2171 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2172 } 2173 return 0; 2174 } 2175 2176 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2177 struct ext4_xattr_info *i, 2178 struct ext4_xattr_ibody_find *is) 2179 { 2180 struct ext4_xattr_ibody_header *header; 2181 struct ext4_xattr_search *s = &is->s; 2182 int error; 2183 2184 if (EXT4_I(inode)->i_extra_isize == 0) 2185 return -ENOSPC; 2186 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2187 if (error) 2188 return error; 2189 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2190 if (!IS_LAST_ENTRY(s->first)) { 2191 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2192 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2193 } else { 2194 header->h_magic = cpu_to_le32(0); 2195 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2196 } 2197 return 0; 2198 } 2199 2200 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2201 struct ext4_xattr_info *i) 2202 { 2203 void *value; 2204 2205 /* When e_value_inum is set the value is stored externally. */ 2206 if (s->here->e_value_inum) 2207 return 0; 2208 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2209 return 0; 2210 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2211 return !memcmp(value, i->value, i->value_len); 2212 } 2213 2214 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2215 { 2216 struct buffer_head *bh; 2217 int error; 2218 2219 if (!EXT4_I(inode)->i_file_acl) 2220 return NULL; 2221 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 2222 if (!bh) 2223 return ERR_PTR(-EIO); 2224 error = ext4_xattr_check_block(inode, bh); 2225 if (error) 2226 return ERR_PTR(error); 2227 return bh; 2228 } 2229 2230 /* 2231 * ext4_xattr_set_handle() 2232 * 2233 * Create, replace or remove an extended attribute for this inode. Value 2234 * is NULL to remove an existing extended attribute, and non-NULL to 2235 * either replace an existing extended attribute, or create a new extended 2236 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2237 * specify that an extended attribute must exist and must not exist 2238 * previous to the call, respectively. 2239 * 2240 * Returns 0, or a negative error number on failure. 2241 */ 2242 int 2243 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2244 const char *name, const void *value, size_t value_len, 2245 int flags) 2246 { 2247 struct ext4_xattr_info i = { 2248 .name_index = name_index, 2249 .name = name, 2250 .value = value, 2251 .value_len = value_len, 2252 .in_inode = 0, 2253 }; 2254 struct ext4_xattr_ibody_find is = { 2255 .s = { .not_found = -ENODATA, }, 2256 }; 2257 struct ext4_xattr_block_find bs = { 2258 .s = { .not_found = -ENODATA, }, 2259 }; 2260 int no_expand; 2261 int error; 2262 2263 if (!name) 2264 return -EINVAL; 2265 if (strlen(name) > 255) 2266 return -ERANGE; 2267 2268 ext4_write_lock_xattr(inode, &no_expand); 2269 2270 /* Check journal credits under write lock. */ 2271 if (ext4_handle_valid(handle)) { 2272 struct buffer_head *bh; 2273 int credits; 2274 2275 bh = ext4_xattr_get_block(inode); 2276 if (IS_ERR(bh)) { 2277 error = PTR_ERR(bh); 2278 goto cleanup; 2279 } 2280 2281 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2282 value_len, 2283 flags & XATTR_CREATE); 2284 brelse(bh); 2285 2286 if (!ext4_handle_has_enough_credits(handle, credits)) { 2287 error = -ENOSPC; 2288 goto cleanup; 2289 } 2290 } 2291 2292 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2293 if (error) 2294 goto cleanup; 2295 2296 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2297 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2298 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2299 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2300 } 2301 2302 error = ext4_xattr_ibody_find(inode, &i, &is); 2303 if (error) 2304 goto cleanup; 2305 if (is.s.not_found) 2306 error = ext4_xattr_block_find(inode, &i, &bs); 2307 if (error) 2308 goto cleanup; 2309 if (is.s.not_found && bs.s.not_found) { 2310 error = -ENODATA; 2311 if (flags & XATTR_REPLACE) 2312 goto cleanup; 2313 error = 0; 2314 if (!value) 2315 goto cleanup; 2316 } else { 2317 error = -EEXIST; 2318 if (flags & XATTR_CREATE) 2319 goto cleanup; 2320 } 2321 2322 if (!value) { 2323 if (!is.s.not_found) 2324 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2325 else if (!bs.s.not_found) 2326 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2327 } else { 2328 error = 0; 2329 /* Xattr value did not change? Save us some work and bail out */ 2330 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2331 goto cleanup; 2332 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2333 goto cleanup; 2334 2335 if (ext4_has_feature_ea_inode(inode->i_sb) && 2336 (EXT4_XATTR_SIZE(i.value_len) > 2337 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2338 i.in_inode = 1; 2339 retry_inode: 2340 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2341 if (!error && !bs.s.not_found) { 2342 i.value = NULL; 2343 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2344 } else if (error == -ENOSPC) { 2345 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2346 error = ext4_xattr_block_find(inode, &i, &bs); 2347 if (error) 2348 goto cleanup; 2349 } 2350 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2351 if (!error && !is.s.not_found) { 2352 i.value = NULL; 2353 error = ext4_xattr_ibody_set(handle, inode, &i, 2354 &is); 2355 } else if (error == -ENOSPC) { 2356 /* 2357 * Xattr does not fit in the block, store at 2358 * external inode if possible. 2359 */ 2360 if (ext4_has_feature_ea_inode(inode->i_sb) && 2361 !i.in_inode) { 2362 i.in_inode = 1; 2363 goto retry_inode; 2364 } 2365 } 2366 } 2367 } 2368 if (!error) { 2369 ext4_xattr_update_super_block(handle, inode->i_sb); 2370 inode->i_ctime = current_time(inode); 2371 if (!value) 2372 no_expand = 0; 2373 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2374 /* 2375 * The bh is consumed by ext4_mark_iloc_dirty, even with 2376 * error != 0. 2377 */ 2378 is.iloc.bh = NULL; 2379 if (IS_SYNC(inode)) 2380 ext4_handle_sync(handle); 2381 } 2382 2383 cleanup: 2384 brelse(is.iloc.bh); 2385 brelse(bs.bh); 2386 ext4_write_unlock_xattr(inode, &no_expand); 2387 return error; 2388 } 2389 2390 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2391 bool is_create, int *credits) 2392 { 2393 struct buffer_head *bh; 2394 int err; 2395 2396 *credits = 0; 2397 2398 if (!EXT4_SB(inode->i_sb)->s_journal) 2399 return 0; 2400 2401 down_read(&EXT4_I(inode)->xattr_sem); 2402 2403 bh = ext4_xattr_get_block(inode); 2404 if (IS_ERR(bh)) { 2405 err = PTR_ERR(bh); 2406 } else { 2407 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2408 value_len, is_create); 2409 brelse(bh); 2410 err = 0; 2411 } 2412 2413 up_read(&EXT4_I(inode)->xattr_sem); 2414 return err; 2415 } 2416 2417 /* 2418 * ext4_xattr_set() 2419 * 2420 * Like ext4_xattr_set_handle, but start from an inode. This extended 2421 * attribute modification is a filesystem transaction by itself. 2422 * 2423 * Returns 0, or a negative error number on failure. 2424 */ 2425 int 2426 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2427 const void *value, size_t value_len, int flags) 2428 { 2429 handle_t *handle; 2430 struct super_block *sb = inode->i_sb; 2431 int error, retries = 0; 2432 int credits; 2433 2434 error = dquot_initialize(inode); 2435 if (error) 2436 return error; 2437 2438 retry: 2439 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2440 &credits); 2441 if (error) 2442 return error; 2443 2444 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2445 if (IS_ERR(handle)) { 2446 error = PTR_ERR(handle); 2447 } else { 2448 int error2; 2449 2450 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2451 value, value_len, flags); 2452 error2 = ext4_journal_stop(handle); 2453 if (error == -ENOSPC && 2454 ext4_should_retry_alloc(sb, &retries)) 2455 goto retry; 2456 if (error == 0) 2457 error = error2; 2458 } 2459 2460 return error; 2461 } 2462 2463 /* 2464 * Shift the EA entries in the inode to create space for the increased 2465 * i_extra_isize. 2466 */ 2467 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2468 int value_offs_shift, void *to, 2469 void *from, size_t n) 2470 { 2471 struct ext4_xattr_entry *last = entry; 2472 int new_offs; 2473 2474 /* We always shift xattr headers further thus offsets get lower */ 2475 BUG_ON(value_offs_shift > 0); 2476 2477 /* Adjust the value offsets of the entries */ 2478 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2479 if (!last->e_value_inum && last->e_value_size) { 2480 new_offs = le16_to_cpu(last->e_value_offs) + 2481 value_offs_shift; 2482 last->e_value_offs = cpu_to_le16(new_offs); 2483 } 2484 } 2485 /* Shift the entries by n bytes */ 2486 memmove(to, from, n); 2487 } 2488 2489 /* 2490 * Move xattr pointed to by 'entry' from inode into external xattr block 2491 */ 2492 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2493 struct ext4_inode *raw_inode, 2494 struct ext4_xattr_entry *entry) 2495 { 2496 struct ext4_xattr_ibody_find *is = NULL; 2497 struct ext4_xattr_block_find *bs = NULL; 2498 char *buffer = NULL, *b_entry_name = NULL; 2499 size_t value_size = le32_to_cpu(entry->e_value_size); 2500 struct ext4_xattr_info i = { 2501 .value = NULL, 2502 .value_len = 0, 2503 .name_index = entry->e_name_index, 2504 .in_inode = !!entry->e_value_inum, 2505 }; 2506 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2507 int error; 2508 2509 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2510 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2511 buffer = kmalloc(value_size, GFP_NOFS); 2512 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2513 if (!is || !bs || !buffer || !b_entry_name) { 2514 error = -ENOMEM; 2515 goto out; 2516 } 2517 2518 is->s.not_found = -ENODATA; 2519 bs->s.not_found = -ENODATA; 2520 is->iloc.bh = NULL; 2521 bs->bh = NULL; 2522 2523 /* Save the entry name and the entry value */ 2524 if (entry->e_value_inum) { 2525 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2526 if (error) 2527 goto out; 2528 } else { 2529 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2530 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2531 } 2532 2533 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2534 b_entry_name[entry->e_name_len] = '\0'; 2535 i.name = b_entry_name; 2536 2537 error = ext4_get_inode_loc(inode, &is->iloc); 2538 if (error) 2539 goto out; 2540 2541 error = ext4_xattr_ibody_find(inode, &i, is); 2542 if (error) 2543 goto out; 2544 2545 /* Remove the chosen entry from the inode */ 2546 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2547 if (error) 2548 goto out; 2549 2550 i.value = buffer; 2551 i.value_len = value_size; 2552 error = ext4_xattr_block_find(inode, &i, bs); 2553 if (error) 2554 goto out; 2555 2556 /* Add entry which was removed from the inode into the block */ 2557 error = ext4_xattr_block_set(handle, inode, &i, bs); 2558 if (error) 2559 goto out; 2560 error = 0; 2561 out: 2562 kfree(b_entry_name); 2563 kfree(buffer); 2564 if (is) 2565 brelse(is->iloc.bh); 2566 kfree(is); 2567 kfree(bs); 2568 2569 return error; 2570 } 2571 2572 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2573 struct ext4_inode *raw_inode, 2574 int isize_diff, size_t ifree, 2575 size_t bfree, int *total_ino) 2576 { 2577 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2578 struct ext4_xattr_entry *small_entry; 2579 struct ext4_xattr_entry *entry; 2580 struct ext4_xattr_entry *last; 2581 unsigned int entry_size; /* EA entry size */ 2582 unsigned int total_size; /* EA entry size + value size */ 2583 unsigned int min_total_size; 2584 int error; 2585 2586 while (isize_diff > ifree) { 2587 entry = NULL; 2588 small_entry = NULL; 2589 min_total_size = ~0U; 2590 last = IFIRST(header); 2591 /* Find the entry best suited to be pushed into EA block */ 2592 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2593 total_size = EXT4_XATTR_LEN(last->e_name_len); 2594 if (!last->e_value_inum) 2595 total_size += EXT4_XATTR_SIZE( 2596 le32_to_cpu(last->e_value_size)); 2597 if (total_size <= bfree && 2598 total_size < min_total_size) { 2599 if (total_size + ifree < isize_diff) { 2600 small_entry = last; 2601 } else { 2602 entry = last; 2603 min_total_size = total_size; 2604 } 2605 } 2606 } 2607 2608 if (entry == NULL) { 2609 if (small_entry == NULL) 2610 return -ENOSPC; 2611 entry = small_entry; 2612 } 2613 2614 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2615 total_size = entry_size; 2616 if (!entry->e_value_inum) 2617 total_size += EXT4_XATTR_SIZE( 2618 le32_to_cpu(entry->e_value_size)); 2619 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2620 entry); 2621 if (error) 2622 return error; 2623 2624 *total_ino -= entry_size; 2625 ifree += total_size; 2626 bfree -= total_size; 2627 } 2628 2629 return 0; 2630 } 2631 2632 /* 2633 * Expand an inode by new_extra_isize bytes when EAs are present. 2634 * Returns 0 on success or negative error number on failure. 2635 */ 2636 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2637 struct ext4_inode *raw_inode, handle_t *handle) 2638 { 2639 struct ext4_xattr_ibody_header *header; 2640 struct buffer_head *bh; 2641 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2642 static unsigned int mnt_count; 2643 size_t min_offs; 2644 size_t ifree, bfree; 2645 int total_ino; 2646 void *base, *end; 2647 int error = 0, tried_min_extra_isize = 0; 2648 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2649 int isize_diff; /* How much do we need to grow i_extra_isize */ 2650 2651 retry: 2652 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2653 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2654 return 0; 2655 2656 header = IHDR(inode, raw_inode); 2657 2658 /* 2659 * Check if enough free space is available in the inode to shift the 2660 * entries ahead by new_extra_isize. 2661 */ 2662 2663 base = IFIRST(header); 2664 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2665 min_offs = end - base; 2666 total_ino = sizeof(struct ext4_xattr_ibody_header); 2667 2668 error = xattr_check_inode(inode, header, end); 2669 if (error) 2670 goto cleanup; 2671 2672 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2673 if (ifree >= isize_diff) 2674 goto shift; 2675 2676 /* 2677 * Enough free space isn't available in the inode, check if 2678 * EA block can hold new_extra_isize bytes. 2679 */ 2680 if (EXT4_I(inode)->i_file_acl) { 2681 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 2682 error = -EIO; 2683 if (!bh) 2684 goto cleanup; 2685 if (ext4_xattr_check_block(inode, bh)) { 2686 EXT4_ERROR_INODE(inode, "bad block %llu", 2687 EXT4_I(inode)->i_file_acl); 2688 error = -EFSCORRUPTED; 2689 brelse(bh); 2690 goto cleanup; 2691 } 2692 base = BHDR(bh); 2693 end = bh->b_data + bh->b_size; 2694 min_offs = end - base; 2695 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2696 NULL); 2697 brelse(bh); 2698 if (bfree + ifree < isize_diff) { 2699 if (!tried_min_extra_isize && s_min_extra_isize) { 2700 tried_min_extra_isize++; 2701 new_extra_isize = s_min_extra_isize; 2702 goto retry; 2703 } 2704 error = -ENOSPC; 2705 goto cleanup; 2706 } 2707 } else { 2708 bfree = inode->i_sb->s_blocksize; 2709 } 2710 2711 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2712 isize_diff, ifree, bfree, 2713 &total_ino); 2714 if (error) { 2715 if (error == -ENOSPC && !tried_min_extra_isize && 2716 s_min_extra_isize) { 2717 tried_min_extra_isize++; 2718 new_extra_isize = s_min_extra_isize; 2719 goto retry; 2720 } 2721 goto cleanup; 2722 } 2723 shift: 2724 /* Adjust the offsets and shift the remaining entries ahead */ 2725 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2726 - new_extra_isize, (void *)raw_inode + 2727 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2728 (void *)header, total_ino); 2729 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2730 2731 cleanup: 2732 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2733 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2734 inode->i_ino); 2735 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2736 } 2737 return error; 2738 } 2739 2740 #define EIA_INCR 16 /* must be 2^n */ 2741 #define EIA_MASK (EIA_INCR - 1) 2742 2743 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2744 * If @ea_inode_array is new or full it will be grown and the old 2745 * contents copied over. 2746 */ 2747 static int 2748 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2749 struct inode *inode) 2750 { 2751 if (*ea_inode_array == NULL) { 2752 /* 2753 * Start with 15 inodes, so it fits into a power-of-two size. 2754 * If *ea_inode_array is NULL, this is essentially offsetof() 2755 */ 2756 (*ea_inode_array) = 2757 kmalloc(offsetof(struct ext4_xattr_inode_array, 2758 inodes[EIA_MASK]), 2759 GFP_NOFS); 2760 if (*ea_inode_array == NULL) 2761 return -ENOMEM; 2762 (*ea_inode_array)->count = 0; 2763 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2764 /* expand the array once all 15 + n * 16 slots are full */ 2765 struct ext4_xattr_inode_array *new_array = NULL; 2766 int count = (*ea_inode_array)->count; 2767 2768 /* if new_array is NULL, this is essentially offsetof() */ 2769 new_array = kmalloc( 2770 offsetof(struct ext4_xattr_inode_array, 2771 inodes[count + EIA_INCR]), 2772 GFP_NOFS); 2773 if (new_array == NULL) 2774 return -ENOMEM; 2775 memcpy(new_array, *ea_inode_array, 2776 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2777 kfree(*ea_inode_array); 2778 *ea_inode_array = new_array; 2779 } 2780 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2781 return 0; 2782 } 2783 2784 /* 2785 * ext4_xattr_delete_inode() 2786 * 2787 * Free extended attribute resources associated with this inode. Traverse 2788 * all entries and decrement reference on any xattr inodes associated with this 2789 * inode. This is called immediately before an inode is freed. We have exclusive 2790 * access to the inode. If an orphan inode is deleted it will also release its 2791 * references on xattr block and xattr inodes. 2792 */ 2793 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2794 struct ext4_xattr_inode_array **ea_inode_array, 2795 int extra_credits) 2796 { 2797 struct buffer_head *bh = NULL; 2798 struct ext4_xattr_ibody_header *header; 2799 struct ext4_iloc iloc = { .bh = NULL }; 2800 struct ext4_xattr_entry *entry; 2801 int error; 2802 2803 error = ext4_xattr_ensure_credits(handle, inode, extra_credits, 2804 NULL /* bh */, 2805 false /* dirty */, 2806 false /* block_csum */); 2807 if (error) { 2808 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2809 goto cleanup; 2810 } 2811 2812 if (ext4_has_feature_ea_inode(inode->i_sb) && 2813 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2814 2815 error = ext4_get_inode_loc(inode, &iloc); 2816 if (error) { 2817 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2818 goto cleanup; 2819 } 2820 2821 error = ext4_journal_get_write_access(handle, iloc.bh); 2822 if (error) { 2823 EXT4_ERROR_INODE(inode, "write access (error %d)", 2824 error); 2825 goto cleanup; 2826 } 2827 2828 header = IHDR(inode, ext4_raw_inode(&iloc)); 2829 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2830 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2831 IFIRST(header), 2832 false /* block_csum */, 2833 ea_inode_array, 2834 extra_credits, 2835 false /* skip_quota */); 2836 } 2837 2838 if (EXT4_I(inode)->i_file_acl) { 2839 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 2840 if (!bh) { 2841 EXT4_ERROR_INODE(inode, "block %llu read error", 2842 EXT4_I(inode)->i_file_acl); 2843 error = -EIO; 2844 goto cleanup; 2845 } 2846 error = ext4_xattr_check_block(inode, bh); 2847 if (error) { 2848 EXT4_ERROR_INODE(inode, "bad block %llu (error %d)", 2849 EXT4_I(inode)->i_file_acl, error); 2850 goto cleanup; 2851 } 2852 2853 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2854 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2855 entry = EXT4_XATTR_NEXT(entry)) 2856 if (entry->e_value_inum) 2857 ext4_xattr_inode_free_quota(inode, 2858 le32_to_cpu(entry->e_value_size)); 2859 2860 } 2861 2862 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2863 extra_credits); 2864 /* 2865 * Update i_file_acl value in the same transaction that releases 2866 * block. 2867 */ 2868 EXT4_I(inode)->i_file_acl = 0; 2869 error = ext4_mark_inode_dirty(handle, inode); 2870 if (error) { 2871 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2872 error); 2873 goto cleanup; 2874 } 2875 } 2876 error = 0; 2877 cleanup: 2878 brelse(iloc.bh); 2879 brelse(bh); 2880 return error; 2881 } 2882 2883 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2884 { 2885 int idx; 2886 2887 if (ea_inode_array == NULL) 2888 return; 2889 2890 for (idx = 0; idx < ea_inode_array->count; ++idx) 2891 iput(ea_inode_array->inodes[idx]); 2892 kfree(ea_inode_array); 2893 } 2894 2895 /* 2896 * ext4_xattr_block_cache_insert() 2897 * 2898 * Create a new entry in the extended attribute block cache, and insert 2899 * it unless such an entry is already in the cache. 2900 * 2901 * Returns 0, or a negative error number on failure. 2902 */ 2903 static void 2904 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2905 struct buffer_head *bh) 2906 { 2907 struct ext4_xattr_header *header = BHDR(bh); 2908 __u32 hash = le32_to_cpu(header->h_hash); 2909 int reusable = le32_to_cpu(header->h_refcount) < 2910 EXT4_XATTR_REFCOUNT_MAX; 2911 int error; 2912 2913 if (!ea_block_cache) 2914 return; 2915 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2916 bh->b_blocknr, reusable); 2917 if (error) { 2918 if (error == -EBUSY) 2919 ea_bdebug(bh, "already in cache"); 2920 } else 2921 ea_bdebug(bh, "inserting [%x]", (int)hash); 2922 } 2923 2924 /* 2925 * ext4_xattr_cmp() 2926 * 2927 * Compare two extended attribute blocks for equality. 2928 * 2929 * Returns 0 if the blocks are equal, 1 if they differ, and 2930 * a negative error number on errors. 2931 */ 2932 static int 2933 ext4_xattr_cmp(struct ext4_xattr_header *header1, 2934 struct ext4_xattr_header *header2) 2935 { 2936 struct ext4_xattr_entry *entry1, *entry2; 2937 2938 entry1 = ENTRY(header1+1); 2939 entry2 = ENTRY(header2+1); 2940 while (!IS_LAST_ENTRY(entry1)) { 2941 if (IS_LAST_ENTRY(entry2)) 2942 return 1; 2943 if (entry1->e_hash != entry2->e_hash || 2944 entry1->e_name_index != entry2->e_name_index || 2945 entry1->e_name_len != entry2->e_name_len || 2946 entry1->e_value_size != entry2->e_value_size || 2947 entry1->e_value_inum != entry2->e_value_inum || 2948 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 2949 return 1; 2950 if (!entry1->e_value_inum && 2951 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 2952 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 2953 le32_to_cpu(entry1->e_value_size))) 2954 return 1; 2955 2956 entry1 = EXT4_XATTR_NEXT(entry1); 2957 entry2 = EXT4_XATTR_NEXT(entry2); 2958 } 2959 if (!IS_LAST_ENTRY(entry2)) 2960 return 1; 2961 return 0; 2962 } 2963 2964 /* 2965 * ext4_xattr_block_cache_find() 2966 * 2967 * Find an identical extended attribute block. 2968 * 2969 * Returns a pointer to the block found, or NULL if such a block was 2970 * not found or an error occurred. 2971 */ 2972 static struct buffer_head * 2973 ext4_xattr_block_cache_find(struct inode *inode, 2974 struct ext4_xattr_header *header, 2975 struct mb_cache_entry **pce) 2976 { 2977 __u32 hash = le32_to_cpu(header->h_hash); 2978 struct mb_cache_entry *ce; 2979 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 2980 2981 if (!ea_block_cache) 2982 return NULL; 2983 if (!header->h_hash) 2984 return NULL; /* never share */ 2985 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 2986 ce = mb_cache_entry_find_first(ea_block_cache, hash); 2987 while (ce) { 2988 struct buffer_head *bh; 2989 2990 bh = sb_bread(inode->i_sb, ce->e_value); 2991 if (!bh) { 2992 EXT4_ERROR_INODE(inode, "block %lu read error", 2993 (unsigned long)ce->e_value); 2994 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 2995 *pce = ce; 2996 return bh; 2997 } 2998 brelse(bh); 2999 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3000 } 3001 return NULL; 3002 } 3003 3004 #define NAME_HASH_SHIFT 5 3005 #define VALUE_HASH_SHIFT 16 3006 3007 /* 3008 * ext4_xattr_hash_entry() 3009 * 3010 * Compute the hash of an extended attribute. 3011 */ 3012 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3013 size_t value_count) 3014 { 3015 __u32 hash = 0; 3016 3017 while (name_len--) { 3018 hash = (hash << NAME_HASH_SHIFT) ^ 3019 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3020 *name++; 3021 } 3022 while (value_count--) { 3023 hash = (hash << VALUE_HASH_SHIFT) ^ 3024 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3025 le32_to_cpu(*value++); 3026 } 3027 return cpu_to_le32(hash); 3028 } 3029 3030 #undef NAME_HASH_SHIFT 3031 #undef VALUE_HASH_SHIFT 3032 3033 #define BLOCK_HASH_SHIFT 16 3034 3035 /* 3036 * ext4_xattr_rehash() 3037 * 3038 * Re-compute the extended attribute hash value after an entry has changed. 3039 */ 3040 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3041 { 3042 struct ext4_xattr_entry *here; 3043 __u32 hash = 0; 3044 3045 here = ENTRY(header+1); 3046 while (!IS_LAST_ENTRY(here)) { 3047 if (!here->e_hash) { 3048 /* Block is not shared if an entry's hash value == 0 */ 3049 hash = 0; 3050 break; 3051 } 3052 hash = (hash << BLOCK_HASH_SHIFT) ^ 3053 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3054 le32_to_cpu(here->e_hash); 3055 here = EXT4_XATTR_NEXT(here); 3056 } 3057 header->h_hash = cpu_to_le32(hash); 3058 } 3059 3060 #undef BLOCK_HASH_SHIFT 3061 3062 #define HASH_BUCKET_BITS 10 3063 3064 struct mb_cache * 3065 ext4_xattr_create_cache(void) 3066 { 3067 return mb_cache_create(HASH_BUCKET_BITS); 3068 } 3069 3070 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3071 { 3072 if (cache) 3073 mb_cache_destroy(cache); 3074 } 3075 3076