1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext4/xattr.c 4 * 5 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 6 * 7 * Fix by Harrison Xing <harrison@mountainviewdata.com>. 8 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>. 9 * Extended attributes for symlinks and special files added per 10 * suggestion of Luka Renko <luka.renko@hermes.si>. 11 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, 12 * Red Hat Inc. 13 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz 14 * and Andreas Gruenbacher <agruen@suse.de>. 15 */ 16 17 /* 18 * Extended attributes are stored directly in inodes (on file systems with 19 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl 20 * field contains the block number if an inode uses an additional block. All 21 * attributes must fit in the inode and one additional block. Blocks that 22 * contain the identical set of attributes may be shared among several inodes. 23 * Identical blocks are detected by keeping a cache of blocks that have 24 * recently been accessed. 25 * 26 * The attributes in inodes and on blocks have a different header; the entries 27 * are stored in the same format: 28 * 29 * +------------------+ 30 * | header | 31 * | entry 1 | | 32 * | entry 2 | | growing downwards 33 * | entry 3 | v 34 * | four null bytes | 35 * | . . . | 36 * | value 1 | ^ 37 * | value 3 | | growing upwards 38 * | value 2 | | 39 * +------------------+ 40 * 41 * The header is followed by multiple entry descriptors. In disk blocks, the 42 * entry descriptors are kept sorted. In inodes, they are unsorted. The 43 * attribute values are aligned to the end of the block in no specific order. 44 * 45 * Locking strategy 46 * ---------------- 47 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem. 48 * EA blocks are only changed if they are exclusive to an inode, so 49 * holding xattr_sem also means that nothing but the EA block's reference 50 * count can change. Multiple writers to the same block are synchronized 51 * by the buffer lock. 52 */ 53 54 #include <linux/init.h> 55 #include <linux/fs.h> 56 #include <linux/slab.h> 57 #include <linux/mbcache.h> 58 #include <linux/quotaops.h> 59 #include <linux/iversion.h> 60 #include "ext4_jbd2.h" 61 #include "ext4.h" 62 #include "xattr.h" 63 #include "acl.h" 64 65 #ifdef EXT4_XATTR_DEBUG 66 # define ea_idebug(inode, fmt, ...) \ 67 printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \ 68 inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__) 69 # define ea_bdebug(bh, fmt, ...) \ 70 printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \ 71 bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__) 72 #else 73 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 74 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 75 #endif 76 77 static void ext4_xattr_block_cache_insert(struct mb_cache *, 78 struct buffer_head *); 79 static struct buffer_head * 80 ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *, 81 struct mb_cache_entry **); 82 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 83 size_t value_count); 84 static void ext4_xattr_rehash(struct ext4_xattr_header *); 85 86 static const struct xattr_handler * const ext4_xattr_handler_map[] = { 87 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, 88 #ifdef CONFIG_EXT4_FS_POSIX_ACL 89 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 90 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 91 #endif 92 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, 93 #ifdef CONFIG_EXT4_FS_SECURITY 94 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, 95 #endif 96 }; 97 98 const struct xattr_handler *ext4_xattr_handlers[] = { 99 &ext4_xattr_user_handler, 100 &ext4_xattr_trusted_handler, 101 #ifdef CONFIG_EXT4_FS_POSIX_ACL 102 &posix_acl_access_xattr_handler, 103 &posix_acl_default_xattr_handler, 104 #endif 105 #ifdef CONFIG_EXT4_FS_SECURITY 106 &ext4_xattr_security_handler, 107 #endif 108 NULL 109 }; 110 111 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ 112 inode->i_sb->s_fs_info)->s_ea_block_cache) 113 114 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \ 115 inode->i_sb->s_fs_info)->s_ea_inode_cache) 116 117 static int 118 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 119 struct inode *inode); 120 121 #ifdef CONFIG_LOCKDEP 122 void ext4_xattr_inode_set_class(struct inode *ea_inode) 123 { 124 lockdep_set_subclass(&ea_inode->i_rwsem, 1); 125 } 126 #endif 127 128 static __le32 ext4_xattr_block_csum(struct inode *inode, 129 sector_t block_nr, 130 struct ext4_xattr_header *hdr) 131 { 132 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 133 __u32 csum; 134 __le64 dsk_block_nr = cpu_to_le64(block_nr); 135 __u32 dummy_csum = 0; 136 int offset = offsetof(struct ext4_xattr_header, h_checksum); 137 138 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr, 139 sizeof(dsk_block_nr)); 140 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset); 141 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 142 offset += sizeof(dummy_csum); 143 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset, 144 EXT4_BLOCK_SIZE(inode->i_sb) - offset); 145 146 return cpu_to_le32(csum); 147 } 148 149 static int ext4_xattr_block_csum_verify(struct inode *inode, 150 struct buffer_head *bh) 151 { 152 struct ext4_xattr_header *hdr = BHDR(bh); 153 int ret = 1; 154 155 if (ext4_has_metadata_csum(inode->i_sb)) { 156 lock_buffer(bh); 157 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, 158 bh->b_blocknr, hdr)); 159 unlock_buffer(bh); 160 } 161 return ret; 162 } 163 164 static void ext4_xattr_block_csum_set(struct inode *inode, 165 struct buffer_head *bh) 166 { 167 if (ext4_has_metadata_csum(inode->i_sb)) 168 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, 169 bh->b_blocknr, BHDR(bh)); 170 } 171 172 static inline const struct xattr_handler * 173 ext4_xattr_handler(int name_index) 174 { 175 const struct xattr_handler *handler = NULL; 176 177 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) 178 handler = ext4_xattr_handler_map[name_index]; 179 return handler; 180 } 181 182 static int 183 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, 184 void *value_start) 185 { 186 struct ext4_xattr_entry *e = entry; 187 188 /* Find the end of the names list */ 189 while (!IS_LAST_ENTRY(e)) { 190 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); 191 if ((void *)next >= end) 192 return -EFSCORRUPTED; 193 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) 194 return -EFSCORRUPTED; 195 e = next; 196 } 197 198 /* Check the values */ 199 while (!IS_LAST_ENTRY(entry)) { 200 u32 size = le32_to_cpu(entry->e_value_size); 201 202 if (size > EXT4_XATTR_SIZE_MAX) 203 return -EFSCORRUPTED; 204 205 if (size != 0 && entry->e_value_inum == 0) { 206 u16 offs = le16_to_cpu(entry->e_value_offs); 207 void *value; 208 209 /* 210 * The value cannot overlap the names, and the value 211 * with padding cannot extend beyond 'end'. Check both 212 * the padded and unpadded sizes, since the size may 213 * overflow to 0 when adding padding. 214 */ 215 if (offs > end - value_start) 216 return -EFSCORRUPTED; 217 value = value_start + offs; 218 if (value < (void *)e + sizeof(u32) || 219 size > end - value || 220 EXT4_XATTR_SIZE(size) > end - value) 221 return -EFSCORRUPTED; 222 } 223 entry = EXT4_XATTR_NEXT(entry); 224 } 225 226 return 0; 227 } 228 229 static inline int 230 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, 231 const char *function, unsigned int line) 232 { 233 int error = -EFSCORRUPTED; 234 235 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || 236 BHDR(bh)->h_blocks != cpu_to_le32(1)) 237 goto errout; 238 if (buffer_verified(bh)) 239 return 0; 240 241 error = -EFSBADCRC; 242 if (!ext4_xattr_block_csum_verify(inode, bh)) 243 goto errout; 244 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, 245 bh->b_data); 246 errout: 247 if (error) 248 __ext4_error_inode(inode, function, line, 0, 249 "corrupted xattr block %llu", 250 (unsigned long long) bh->b_blocknr); 251 else 252 set_buffer_verified(bh); 253 return error; 254 } 255 256 #define ext4_xattr_check_block(inode, bh) \ 257 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) 258 259 260 static int 261 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, 262 void *end, const char *function, unsigned int line) 263 { 264 int error = -EFSCORRUPTED; 265 266 if (end - (void *)header < sizeof(*header) + sizeof(u32) || 267 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC))) 268 goto errout; 269 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header)); 270 errout: 271 if (error) 272 __ext4_error_inode(inode, function, line, 0, 273 "corrupted in-inode xattr"); 274 return error; 275 } 276 277 #define xattr_check_inode(inode, header, end) \ 278 __xattr_check_inode((inode), (header), (end), __func__, __LINE__) 279 280 static int 281 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, 282 void *end, int name_index, const char *name, int sorted) 283 { 284 struct ext4_xattr_entry *entry, *next; 285 size_t name_len; 286 int cmp = 1; 287 288 if (name == NULL) 289 return -EINVAL; 290 name_len = strlen(name); 291 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { 292 next = EXT4_XATTR_NEXT(entry); 293 if ((void *) next >= end) { 294 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 295 return -EFSCORRUPTED; 296 } 297 cmp = name_index - entry->e_name_index; 298 if (!cmp) 299 cmp = name_len - entry->e_name_len; 300 if (!cmp) 301 cmp = memcmp(name, entry->e_name, name_len); 302 if (cmp <= 0 && (sorted || cmp == 0)) 303 break; 304 } 305 *pentry = entry; 306 return cmp ? -ENODATA : 0; 307 } 308 309 static u32 310 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size) 311 { 312 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size); 313 } 314 315 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode) 316 { 317 return ((u64)ea_inode->i_ctime.tv_sec << 32) | 318 (u32) inode_peek_iversion_raw(ea_inode); 319 } 320 321 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count) 322 { 323 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32); 324 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff); 325 } 326 327 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode) 328 { 329 return (u32)ea_inode->i_atime.tv_sec; 330 } 331 332 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash) 333 { 334 ea_inode->i_atime.tv_sec = hash; 335 } 336 337 /* 338 * Read the EA value from an inode. 339 */ 340 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) 341 { 342 int blocksize = 1 << ea_inode->i_blkbits; 343 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits; 344 int tail_size = (size % blocksize) ?: blocksize; 345 struct buffer_head *bhs_inline[8]; 346 struct buffer_head **bhs = bhs_inline; 347 int i, ret; 348 349 if (bh_count > ARRAY_SIZE(bhs_inline)) { 350 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS); 351 if (!bhs) 352 return -ENOMEM; 353 } 354 355 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count, 356 true /* wait */, bhs); 357 if (ret) 358 goto free_bhs; 359 360 for (i = 0; i < bh_count; i++) { 361 /* There shouldn't be any holes in ea_inode. */ 362 if (!bhs[i]) { 363 ret = -EFSCORRUPTED; 364 goto put_bhs; 365 } 366 memcpy((char *)buf + blocksize * i, bhs[i]->b_data, 367 i < bh_count - 1 ? blocksize : tail_size); 368 } 369 ret = 0; 370 put_bhs: 371 for (i = 0; i < bh_count; i++) 372 brelse(bhs[i]); 373 free_bhs: 374 if (bhs != bhs_inline) 375 kfree(bhs); 376 return ret; 377 } 378 379 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec) 380 381 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, 382 u32 ea_inode_hash, struct inode **ea_inode) 383 { 384 struct inode *inode; 385 int err; 386 387 inode = ext4_iget(parent->i_sb, ea_ino); 388 if (IS_ERR(inode)) { 389 err = PTR_ERR(inode); 390 ext4_error(parent->i_sb, 391 "error while reading EA inode %lu err=%d", ea_ino, 392 err); 393 return err; 394 } 395 396 if (is_bad_inode(inode)) { 397 ext4_error(parent->i_sb, 398 "error while reading EA inode %lu is_bad_inode", 399 ea_ino); 400 err = -EIO; 401 goto error; 402 } 403 404 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { 405 ext4_error(parent->i_sb, 406 "EA inode %lu does not have EXT4_EA_INODE_FL flag", 407 ea_ino); 408 err = -EINVAL; 409 goto error; 410 } 411 412 ext4_xattr_inode_set_class(inode); 413 414 /* 415 * Check whether this is an old Lustre-style xattr inode. Lustre 416 * implementation does not have hash validation, rather it has a 417 * backpointer from ea_inode to the parent inode. 418 */ 419 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) && 420 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino && 421 inode->i_generation == parent->i_generation) { 422 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE); 423 ext4_xattr_inode_set_ref(inode, 1); 424 } else { 425 inode_lock(inode); 426 inode->i_flags |= S_NOQUOTA; 427 inode_unlock(inode); 428 } 429 430 *ea_inode = inode; 431 return 0; 432 error: 433 iput(inode); 434 return err; 435 } 436 437 static int 438 ext4_xattr_inode_verify_hashes(struct inode *ea_inode, 439 struct ext4_xattr_entry *entry, void *buffer, 440 size_t size) 441 { 442 u32 hash; 443 444 /* Verify stored hash matches calculated hash. */ 445 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size); 446 if (hash != ext4_xattr_inode_get_hash(ea_inode)) 447 return -EFSCORRUPTED; 448 449 if (entry) { 450 __le32 e_hash, tmp_data; 451 452 /* Verify entry hash. */ 453 tmp_data = cpu_to_le32(hash); 454 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len, 455 &tmp_data, 1); 456 if (e_hash != entry->e_hash) 457 return -EFSCORRUPTED; 458 } 459 return 0; 460 } 461 462 /* 463 * Read xattr value from the EA inode. 464 */ 465 static int 466 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry, 467 void *buffer, size_t size) 468 { 469 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 470 struct inode *ea_inode; 471 int err; 472 473 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum), 474 le32_to_cpu(entry->e_hash), &ea_inode); 475 if (err) { 476 ea_inode = NULL; 477 goto out; 478 } 479 480 if (i_size_read(ea_inode) != size) { 481 ext4_warning_inode(ea_inode, 482 "ea_inode file size=%llu entry size=%zu", 483 i_size_read(ea_inode), size); 484 err = -EFSCORRUPTED; 485 goto out; 486 } 487 488 err = ext4_xattr_inode_read(ea_inode, buffer, size); 489 if (err) 490 goto out; 491 492 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) { 493 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer, 494 size); 495 if (err) { 496 ext4_warning_inode(ea_inode, 497 "EA inode hash validation failed"); 498 goto out; 499 } 500 501 if (ea_inode_cache) 502 mb_cache_entry_create(ea_inode_cache, GFP_NOFS, 503 ext4_xattr_inode_get_hash(ea_inode), 504 ea_inode->i_ino, true /* reusable */); 505 } 506 out: 507 iput(ea_inode); 508 return err; 509 } 510 511 static int 512 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, 513 void *buffer, size_t buffer_size) 514 { 515 struct buffer_head *bh = NULL; 516 struct ext4_xattr_entry *entry; 517 size_t size; 518 void *end; 519 int error; 520 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 521 522 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 523 name_index, name, buffer, (long)buffer_size); 524 525 error = -ENODATA; 526 if (!EXT4_I(inode)->i_file_acl) 527 goto cleanup; 528 ea_idebug(inode, "reading block %llu", 529 (unsigned long long)EXT4_I(inode)->i_file_acl); 530 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 531 if (!bh) 532 goto cleanup; 533 ea_bdebug(bh, "b_count=%d, refcount=%d", 534 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 535 error = ext4_xattr_check_block(inode, bh); 536 if (error) 537 goto cleanup; 538 ext4_xattr_block_cache_insert(ea_block_cache, bh); 539 entry = BFIRST(bh); 540 end = bh->b_data + bh->b_size; 541 error = xattr_find_entry(inode, &entry, end, name_index, name, 1); 542 if (error) 543 goto cleanup; 544 size = le32_to_cpu(entry->e_value_size); 545 error = -ERANGE; 546 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 547 goto cleanup; 548 if (buffer) { 549 if (size > buffer_size) 550 goto cleanup; 551 if (entry->e_value_inum) { 552 error = ext4_xattr_inode_get(inode, entry, buffer, 553 size); 554 if (error) 555 goto cleanup; 556 } else { 557 u16 offset = le16_to_cpu(entry->e_value_offs); 558 void *p = bh->b_data + offset; 559 560 if (unlikely(p + size > end)) 561 goto cleanup; 562 memcpy(buffer, p, size); 563 } 564 } 565 error = size; 566 567 cleanup: 568 brelse(bh); 569 return error; 570 } 571 572 int 573 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 574 void *buffer, size_t buffer_size) 575 { 576 struct ext4_xattr_ibody_header *header; 577 struct ext4_xattr_entry *entry; 578 struct ext4_inode *raw_inode; 579 struct ext4_iloc iloc; 580 size_t size; 581 void *end; 582 int error; 583 584 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 585 return -ENODATA; 586 error = ext4_get_inode_loc(inode, &iloc); 587 if (error) 588 return error; 589 raw_inode = ext4_raw_inode(&iloc); 590 header = IHDR(inode, raw_inode); 591 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 592 error = xattr_check_inode(inode, header, end); 593 if (error) 594 goto cleanup; 595 entry = IFIRST(header); 596 error = xattr_find_entry(inode, &entry, end, name_index, name, 0); 597 if (error) 598 goto cleanup; 599 size = le32_to_cpu(entry->e_value_size); 600 error = -ERANGE; 601 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 602 goto cleanup; 603 if (buffer) { 604 if (size > buffer_size) 605 goto cleanup; 606 if (entry->e_value_inum) { 607 error = ext4_xattr_inode_get(inode, entry, buffer, 608 size); 609 if (error) 610 goto cleanup; 611 } else { 612 u16 offset = le16_to_cpu(entry->e_value_offs); 613 void *p = (void *)IFIRST(header) + offset; 614 615 if (unlikely(p + size > end)) 616 goto cleanup; 617 memcpy(buffer, p, size); 618 } 619 } 620 error = size; 621 622 cleanup: 623 brelse(iloc.bh); 624 return error; 625 } 626 627 /* 628 * ext4_xattr_get() 629 * 630 * Copy an extended attribute into the buffer 631 * provided, or compute the buffer size required. 632 * Buffer is NULL to compute the size of the buffer required. 633 * 634 * Returns a negative error number on failure, or the number of bytes 635 * used / required on success. 636 */ 637 int 638 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 639 void *buffer, size_t buffer_size) 640 { 641 int error; 642 643 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 644 return -EIO; 645 646 if (strlen(name) > 255) 647 return -ERANGE; 648 649 down_read(&EXT4_I(inode)->xattr_sem); 650 error = ext4_xattr_ibody_get(inode, name_index, name, buffer, 651 buffer_size); 652 if (error == -ENODATA) 653 error = ext4_xattr_block_get(inode, name_index, name, buffer, 654 buffer_size); 655 up_read(&EXT4_I(inode)->xattr_sem); 656 return error; 657 } 658 659 static int 660 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, 661 char *buffer, size_t buffer_size) 662 { 663 size_t rest = buffer_size; 664 665 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 666 const struct xattr_handler *handler = 667 ext4_xattr_handler(entry->e_name_index); 668 669 if (handler && (!handler->list || handler->list(dentry))) { 670 const char *prefix = handler->prefix ?: handler->name; 671 size_t prefix_len = strlen(prefix); 672 size_t size = prefix_len + entry->e_name_len + 1; 673 674 if (buffer) { 675 if (size > rest) 676 return -ERANGE; 677 memcpy(buffer, prefix, prefix_len); 678 buffer += prefix_len; 679 memcpy(buffer, entry->e_name, entry->e_name_len); 680 buffer += entry->e_name_len; 681 *buffer++ = 0; 682 } 683 rest -= size; 684 } 685 } 686 return buffer_size - rest; /* total size */ 687 } 688 689 static int 690 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) 691 { 692 struct inode *inode = d_inode(dentry); 693 struct buffer_head *bh = NULL; 694 int error; 695 696 ea_idebug(inode, "buffer=%p, buffer_size=%ld", 697 buffer, (long)buffer_size); 698 699 error = 0; 700 if (!EXT4_I(inode)->i_file_acl) 701 goto cleanup; 702 ea_idebug(inode, "reading block %llu", 703 (unsigned long long)EXT4_I(inode)->i_file_acl); 704 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 705 error = -EIO; 706 if (!bh) 707 goto cleanup; 708 ea_bdebug(bh, "b_count=%d, refcount=%d", 709 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 710 error = ext4_xattr_check_block(inode, bh); 711 if (error) 712 goto cleanup; 713 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); 714 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size); 715 716 cleanup: 717 brelse(bh); 718 719 return error; 720 } 721 722 static int 723 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 724 { 725 struct inode *inode = d_inode(dentry); 726 struct ext4_xattr_ibody_header *header; 727 struct ext4_inode *raw_inode; 728 struct ext4_iloc iloc; 729 void *end; 730 int error; 731 732 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 733 return 0; 734 error = ext4_get_inode_loc(inode, &iloc); 735 if (error) 736 return error; 737 raw_inode = ext4_raw_inode(&iloc); 738 header = IHDR(inode, raw_inode); 739 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 740 error = xattr_check_inode(inode, header, end); 741 if (error) 742 goto cleanup; 743 error = ext4_xattr_list_entries(dentry, IFIRST(header), 744 buffer, buffer_size); 745 746 cleanup: 747 brelse(iloc.bh); 748 return error; 749 } 750 751 /* 752 * Inode operation listxattr() 753 * 754 * d_inode(dentry)->i_rwsem: don't care 755 * 756 * Copy a list of attribute names into the buffer 757 * provided, or compute the buffer size required. 758 * Buffer is NULL to compute the size of the buffer required. 759 * 760 * Returns a negative error number on failure, or the number of bytes 761 * used / required on success. 762 */ 763 ssize_t 764 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 765 { 766 int ret, ret2; 767 768 down_read(&EXT4_I(d_inode(dentry))->xattr_sem); 769 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); 770 if (ret < 0) 771 goto errout; 772 if (buffer) { 773 buffer += ret; 774 buffer_size -= ret; 775 } 776 ret = ext4_xattr_block_list(dentry, buffer, buffer_size); 777 if (ret < 0) 778 goto errout; 779 ret += ret2; 780 errout: 781 up_read(&EXT4_I(d_inode(dentry))->xattr_sem); 782 return ret; 783 } 784 785 /* 786 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is 787 * not set, set it. 788 */ 789 static void ext4_xattr_update_super_block(handle_t *handle, 790 struct super_block *sb) 791 { 792 if (ext4_has_feature_xattr(sb)) 793 return; 794 795 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 796 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { 797 ext4_set_feature_xattr(sb); 798 ext4_handle_dirty_super(handle, sb); 799 } 800 } 801 802 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 803 { 804 struct ext4_iloc iloc = { .bh = NULL }; 805 struct buffer_head *bh = NULL; 806 struct ext4_inode *raw_inode; 807 struct ext4_xattr_ibody_header *header; 808 struct ext4_xattr_entry *entry; 809 qsize_t ea_inode_refs = 0; 810 void *end; 811 int ret; 812 813 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); 814 815 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 816 ret = ext4_get_inode_loc(inode, &iloc); 817 if (ret) 818 goto out; 819 raw_inode = ext4_raw_inode(&iloc); 820 header = IHDR(inode, raw_inode); 821 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 822 ret = xattr_check_inode(inode, header, end); 823 if (ret) 824 goto out; 825 826 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); 827 entry = EXT4_XATTR_NEXT(entry)) 828 if (entry->e_value_inum) 829 ea_inode_refs++; 830 } 831 832 if (EXT4_I(inode)->i_file_acl) { 833 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 834 if (!bh) { 835 ret = -EIO; 836 goto out; 837 } 838 839 ret = ext4_xattr_check_block(inode, bh); 840 if (ret) 841 goto out; 842 843 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 844 entry = EXT4_XATTR_NEXT(entry)) 845 if (entry->e_value_inum) 846 ea_inode_refs++; 847 } 848 *usage = ea_inode_refs + 1; 849 ret = 0; 850 out: 851 brelse(iloc.bh); 852 brelse(bh); 853 return ret; 854 } 855 856 static inline size_t round_up_cluster(struct inode *inode, size_t length) 857 { 858 struct super_block *sb = inode->i_sb; 859 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits + 860 inode->i_blkbits); 861 size_t mask = ~(cluster_size - 1); 862 863 return (length + cluster_size - 1) & mask; 864 } 865 866 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len) 867 { 868 int err; 869 870 err = dquot_alloc_inode(inode); 871 if (err) 872 return err; 873 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len)); 874 if (err) 875 dquot_free_inode(inode); 876 return err; 877 } 878 879 static void ext4_xattr_inode_free_quota(struct inode *parent, 880 struct inode *ea_inode, 881 size_t len) 882 { 883 if (ea_inode && 884 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) 885 return; 886 dquot_free_space_nodirty(parent, round_up_cluster(parent, len)); 887 dquot_free_inode(parent); 888 } 889 890 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, 891 struct buffer_head *block_bh, size_t value_len, 892 bool is_create) 893 { 894 int credits; 895 int blocks; 896 897 /* 898 * 1) Owner inode update 899 * 2) Ref count update on old xattr block 900 * 3) new xattr block 901 * 4) block bitmap update for new xattr block 902 * 5) group descriptor for new xattr block 903 * 6) block bitmap update for old xattr block 904 * 7) group descriptor for old block 905 * 906 * 6 & 7 can happen if we have two racing threads T_a and T_b 907 * which are each trying to set an xattr on inodes I_a and I_b 908 * which were both initially sharing an xattr block. 909 */ 910 credits = 7; 911 912 /* Quota updates. */ 913 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb); 914 915 /* 916 * In case of inline data, we may push out the data to a block, 917 * so we need to reserve credits for this eventuality 918 */ 919 if (inode && ext4_has_inline_data(inode)) 920 credits += ext4_writepage_trans_blocks(inode) + 1; 921 922 /* We are done if ea_inode feature is not enabled. */ 923 if (!ext4_has_feature_ea_inode(sb)) 924 return credits; 925 926 /* New ea_inode, inode map, block bitmap, group descriptor. */ 927 credits += 4; 928 929 /* Data blocks. */ 930 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 931 932 /* Indirection block or one level of extent tree. */ 933 blocks += 1; 934 935 /* Block bitmap and group descriptor updates for each block. */ 936 credits += blocks * 2; 937 938 /* Blocks themselves. */ 939 credits += blocks; 940 941 if (!is_create) { 942 /* Dereference ea_inode holding old xattr value. 943 * Old ea_inode, inode map, block bitmap, group descriptor. 944 */ 945 credits += 4; 946 947 /* Data blocks for old ea_inode. */ 948 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits; 949 950 /* Indirection block or one level of extent tree for old 951 * ea_inode. 952 */ 953 blocks += 1; 954 955 /* Block bitmap and group descriptor updates for each block. */ 956 credits += blocks * 2; 957 } 958 959 /* We may need to clone the existing xattr block in which case we need 960 * to increment ref counts for existing ea_inodes referenced by it. 961 */ 962 if (block_bh) { 963 struct ext4_xattr_entry *entry = BFIRST(block_bh); 964 965 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) 966 if (entry->e_value_inum) 967 /* Ref count update on ea_inode. */ 968 credits += 1; 969 } 970 return credits; 971 } 972 973 static int ext4_xattr_ensure_credits(handle_t *handle, struct inode *inode, 974 int credits, struct buffer_head *bh, 975 bool dirty, bool block_csum) 976 { 977 int error; 978 979 if (!ext4_handle_valid(handle)) 980 return 0; 981 982 if (handle->h_buffer_credits >= credits) 983 return 0; 984 985 error = ext4_journal_extend(handle, credits - handle->h_buffer_credits); 986 if (!error) 987 return 0; 988 if (error < 0) { 989 ext4_warning(inode->i_sb, "Extend journal (error %d)", error); 990 return error; 991 } 992 993 if (bh && dirty) { 994 if (block_csum) 995 ext4_xattr_block_csum_set(inode, bh); 996 error = ext4_handle_dirty_metadata(handle, NULL, bh); 997 if (error) { 998 ext4_warning(inode->i_sb, "Handle metadata (error %d)", 999 error); 1000 return error; 1001 } 1002 } 1003 1004 error = ext4_journal_restart(handle, credits); 1005 if (error) { 1006 ext4_warning(inode->i_sb, "Restart journal (error %d)", error); 1007 return error; 1008 } 1009 1010 if (bh) { 1011 error = ext4_journal_get_write_access(handle, bh); 1012 if (error) { 1013 ext4_warning(inode->i_sb, 1014 "Get write access failed (error %d)", 1015 error); 1016 return error; 1017 } 1018 } 1019 return 0; 1020 } 1021 1022 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode, 1023 int ref_change) 1024 { 1025 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode); 1026 struct ext4_iloc iloc; 1027 s64 ref_count; 1028 u32 hash; 1029 int ret; 1030 1031 inode_lock(ea_inode); 1032 1033 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc); 1034 if (ret) 1035 goto out; 1036 1037 ref_count = ext4_xattr_inode_get_ref(ea_inode); 1038 ref_count += ref_change; 1039 ext4_xattr_inode_set_ref(ea_inode, ref_count); 1040 1041 if (ref_change > 0) { 1042 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld", 1043 ea_inode->i_ino, ref_count); 1044 1045 if (ref_count == 1) { 1046 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u", 1047 ea_inode->i_ino, ea_inode->i_nlink); 1048 1049 set_nlink(ea_inode, 1); 1050 ext4_orphan_del(handle, ea_inode); 1051 1052 if (ea_inode_cache) { 1053 hash = ext4_xattr_inode_get_hash(ea_inode); 1054 mb_cache_entry_create(ea_inode_cache, 1055 GFP_NOFS, hash, 1056 ea_inode->i_ino, 1057 true /* reusable */); 1058 } 1059 } 1060 } else { 1061 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld", 1062 ea_inode->i_ino, ref_count); 1063 1064 if (ref_count == 0) { 1065 WARN_ONCE(ea_inode->i_nlink != 1, 1066 "EA inode %lu i_nlink=%u", 1067 ea_inode->i_ino, ea_inode->i_nlink); 1068 1069 clear_nlink(ea_inode); 1070 ext4_orphan_add(handle, ea_inode); 1071 1072 if (ea_inode_cache) { 1073 hash = ext4_xattr_inode_get_hash(ea_inode); 1074 mb_cache_entry_delete(ea_inode_cache, hash, 1075 ea_inode->i_ino); 1076 } 1077 } 1078 } 1079 1080 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc); 1081 if (ret) 1082 ext4_warning_inode(ea_inode, 1083 "ext4_mark_iloc_dirty() failed ret=%d", ret); 1084 out: 1085 inode_unlock(ea_inode); 1086 return ret; 1087 } 1088 1089 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode) 1090 { 1091 return ext4_xattr_inode_update_ref(handle, ea_inode, 1); 1092 } 1093 1094 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode) 1095 { 1096 return ext4_xattr_inode_update_ref(handle, ea_inode, -1); 1097 } 1098 1099 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent, 1100 struct ext4_xattr_entry *first) 1101 { 1102 struct inode *ea_inode; 1103 struct ext4_xattr_entry *entry; 1104 struct ext4_xattr_entry *failed_entry; 1105 unsigned int ea_ino; 1106 int err, saved_err; 1107 1108 for (entry = first; !IS_LAST_ENTRY(entry); 1109 entry = EXT4_XATTR_NEXT(entry)) { 1110 if (!entry->e_value_inum) 1111 continue; 1112 ea_ino = le32_to_cpu(entry->e_value_inum); 1113 err = ext4_xattr_inode_iget(parent, ea_ino, 1114 le32_to_cpu(entry->e_hash), 1115 &ea_inode); 1116 if (err) 1117 goto cleanup; 1118 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1119 if (err) { 1120 ext4_warning_inode(ea_inode, "inc ref error %d", err); 1121 iput(ea_inode); 1122 goto cleanup; 1123 } 1124 iput(ea_inode); 1125 } 1126 return 0; 1127 1128 cleanup: 1129 saved_err = err; 1130 failed_entry = entry; 1131 1132 for (entry = first; entry != failed_entry; 1133 entry = EXT4_XATTR_NEXT(entry)) { 1134 if (!entry->e_value_inum) 1135 continue; 1136 ea_ino = le32_to_cpu(entry->e_value_inum); 1137 err = ext4_xattr_inode_iget(parent, ea_ino, 1138 le32_to_cpu(entry->e_hash), 1139 &ea_inode); 1140 if (err) { 1141 ext4_warning(parent->i_sb, 1142 "cleanup ea_ino %u iget error %d", ea_ino, 1143 err); 1144 continue; 1145 } 1146 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1147 if (err) 1148 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", 1149 err); 1150 iput(ea_inode); 1151 } 1152 return saved_err; 1153 } 1154 1155 static void 1156 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent, 1157 struct buffer_head *bh, 1158 struct ext4_xattr_entry *first, bool block_csum, 1159 struct ext4_xattr_inode_array **ea_inode_array, 1160 int extra_credits, bool skip_quota) 1161 { 1162 struct inode *ea_inode; 1163 struct ext4_xattr_entry *entry; 1164 bool dirty = false; 1165 unsigned int ea_ino; 1166 int err; 1167 int credits; 1168 1169 /* One credit for dec ref on ea_inode, one for orphan list addition, */ 1170 credits = 2 + extra_credits; 1171 1172 for (entry = first; !IS_LAST_ENTRY(entry); 1173 entry = EXT4_XATTR_NEXT(entry)) { 1174 if (!entry->e_value_inum) 1175 continue; 1176 ea_ino = le32_to_cpu(entry->e_value_inum); 1177 err = ext4_xattr_inode_iget(parent, ea_ino, 1178 le32_to_cpu(entry->e_hash), 1179 &ea_inode); 1180 if (err) 1181 continue; 1182 1183 err = ext4_expand_inode_array(ea_inode_array, ea_inode); 1184 if (err) { 1185 ext4_warning_inode(ea_inode, 1186 "Expand inode array err=%d", err); 1187 iput(ea_inode); 1188 continue; 1189 } 1190 1191 err = ext4_xattr_ensure_credits(handle, parent, credits, bh, 1192 dirty, block_csum); 1193 if (err) { 1194 ext4_warning_inode(ea_inode, "Ensure credits err=%d", 1195 err); 1196 continue; 1197 } 1198 1199 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1200 if (err) { 1201 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d", 1202 err); 1203 continue; 1204 } 1205 1206 if (!skip_quota) 1207 ext4_xattr_inode_free_quota(parent, ea_inode, 1208 le32_to_cpu(entry->e_value_size)); 1209 1210 /* 1211 * Forget about ea_inode within the same transaction that 1212 * decrements the ref count. This avoids duplicate decrements in 1213 * case the rest of the work spills over to subsequent 1214 * transactions. 1215 */ 1216 entry->e_value_inum = 0; 1217 entry->e_value_size = 0; 1218 1219 dirty = true; 1220 } 1221 1222 if (dirty) { 1223 /* 1224 * Note that we are deliberately skipping csum calculation for 1225 * the final update because we do not expect any journal 1226 * restarts until xattr block is freed. 1227 */ 1228 1229 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1230 if (err) 1231 ext4_warning_inode(parent, 1232 "handle dirty metadata err=%d", err); 1233 } 1234 } 1235 1236 /* 1237 * Release the xattr block BH: If the reference count is > 1, decrement it; 1238 * otherwise free the block. 1239 */ 1240 static void 1241 ext4_xattr_release_block(handle_t *handle, struct inode *inode, 1242 struct buffer_head *bh, 1243 struct ext4_xattr_inode_array **ea_inode_array, 1244 int extra_credits) 1245 { 1246 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1247 u32 hash, ref; 1248 int error = 0; 1249 1250 BUFFER_TRACE(bh, "get_write_access"); 1251 error = ext4_journal_get_write_access(handle, bh); 1252 if (error) 1253 goto out; 1254 1255 lock_buffer(bh); 1256 hash = le32_to_cpu(BHDR(bh)->h_hash); 1257 ref = le32_to_cpu(BHDR(bh)->h_refcount); 1258 if (ref == 1) { 1259 ea_bdebug(bh, "refcount now=0; freeing"); 1260 /* 1261 * This must happen under buffer lock for 1262 * ext4_xattr_block_set() to reliably detect freed block 1263 */ 1264 if (ea_block_cache) 1265 mb_cache_entry_delete(ea_block_cache, hash, 1266 bh->b_blocknr); 1267 get_bh(bh); 1268 unlock_buffer(bh); 1269 1270 if (ext4_has_feature_ea_inode(inode->i_sb)) 1271 ext4_xattr_inode_dec_ref_all(handle, inode, bh, 1272 BFIRST(bh), 1273 true /* block_csum */, 1274 ea_inode_array, 1275 extra_credits, 1276 true /* skip_quota */); 1277 ext4_free_blocks(handle, inode, bh, 0, 1, 1278 EXT4_FREE_BLOCKS_METADATA | 1279 EXT4_FREE_BLOCKS_FORGET); 1280 } else { 1281 ref--; 1282 BHDR(bh)->h_refcount = cpu_to_le32(ref); 1283 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) { 1284 struct mb_cache_entry *ce; 1285 1286 if (ea_block_cache) { 1287 ce = mb_cache_entry_get(ea_block_cache, hash, 1288 bh->b_blocknr); 1289 if (ce) { 1290 ce->e_reusable = 1; 1291 mb_cache_entry_put(ea_block_cache, ce); 1292 } 1293 } 1294 } 1295 1296 ext4_xattr_block_csum_set(inode, bh); 1297 /* 1298 * Beware of this ugliness: Releasing of xattr block references 1299 * from different inodes can race and so we have to protect 1300 * from a race where someone else frees the block (and releases 1301 * its journal_head) before we are done dirtying the buffer. In 1302 * nojournal mode this race is harmless and we actually cannot 1303 * call ext4_handle_dirty_metadata() with locked buffer as 1304 * that function can call sync_dirty_buffer() so for that case 1305 * we handle the dirtying after unlocking the buffer. 1306 */ 1307 if (ext4_handle_valid(handle)) 1308 error = ext4_handle_dirty_metadata(handle, inode, bh); 1309 unlock_buffer(bh); 1310 if (!ext4_handle_valid(handle)) 1311 error = ext4_handle_dirty_metadata(handle, inode, bh); 1312 if (IS_SYNC(inode)) 1313 ext4_handle_sync(handle); 1314 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); 1315 ea_bdebug(bh, "refcount now=%d; releasing", 1316 le32_to_cpu(BHDR(bh)->h_refcount)); 1317 } 1318 out: 1319 ext4_std_error(inode->i_sb, error); 1320 return; 1321 } 1322 1323 /* 1324 * Find the available free space for EAs. This also returns the total number of 1325 * bytes used by EA entries. 1326 */ 1327 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, 1328 size_t *min_offs, void *base, int *total) 1329 { 1330 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1331 if (!last->e_value_inum && last->e_value_size) { 1332 size_t offs = le16_to_cpu(last->e_value_offs); 1333 if (offs < *min_offs) 1334 *min_offs = offs; 1335 } 1336 if (total) 1337 *total += EXT4_XATTR_LEN(last->e_name_len); 1338 } 1339 return (*min_offs - ((void *)last - base) - sizeof(__u32)); 1340 } 1341 1342 /* 1343 * Write the value of the EA in an inode. 1344 */ 1345 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode, 1346 const void *buf, int bufsize) 1347 { 1348 struct buffer_head *bh = NULL; 1349 unsigned long block = 0; 1350 int blocksize = ea_inode->i_sb->s_blocksize; 1351 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits; 1352 int csize, wsize = 0; 1353 int ret = 0; 1354 int retries = 0; 1355 1356 retry: 1357 while (ret >= 0 && ret < max_blocks) { 1358 struct ext4_map_blocks map; 1359 map.m_lblk = block += ret; 1360 map.m_len = max_blocks -= ret; 1361 1362 ret = ext4_map_blocks(handle, ea_inode, &map, 1363 EXT4_GET_BLOCKS_CREATE); 1364 if (ret <= 0) { 1365 ext4_mark_inode_dirty(handle, ea_inode); 1366 if (ret == -ENOSPC && 1367 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) { 1368 ret = 0; 1369 goto retry; 1370 } 1371 break; 1372 } 1373 } 1374 1375 if (ret < 0) 1376 return ret; 1377 1378 block = 0; 1379 while (wsize < bufsize) { 1380 if (bh != NULL) 1381 brelse(bh); 1382 csize = (bufsize - wsize) > blocksize ? blocksize : 1383 bufsize - wsize; 1384 bh = ext4_getblk(handle, ea_inode, block, 0); 1385 if (IS_ERR(bh)) 1386 return PTR_ERR(bh); 1387 if (!bh) { 1388 WARN_ON_ONCE(1); 1389 EXT4_ERROR_INODE(ea_inode, 1390 "ext4_getblk() return bh = NULL"); 1391 return -EFSCORRUPTED; 1392 } 1393 ret = ext4_journal_get_write_access(handle, bh); 1394 if (ret) 1395 goto out; 1396 1397 memcpy(bh->b_data, buf, csize); 1398 set_buffer_uptodate(bh); 1399 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1400 1401 buf += csize; 1402 wsize += csize; 1403 block += 1; 1404 } 1405 1406 inode_lock(ea_inode); 1407 i_size_write(ea_inode, wsize); 1408 ext4_update_i_disksize(ea_inode, wsize); 1409 inode_unlock(ea_inode); 1410 1411 ext4_mark_inode_dirty(handle, ea_inode); 1412 1413 out: 1414 brelse(bh); 1415 1416 return ret; 1417 } 1418 1419 /* 1420 * Create an inode to store the value of a large EA. 1421 */ 1422 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1423 struct inode *inode, u32 hash) 1424 { 1425 struct inode *ea_inode = NULL; 1426 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1427 int err; 1428 1429 /* 1430 * Let the next inode be the goal, so we try and allocate the EA inode 1431 * in the same group, or nearby one. 1432 */ 1433 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1434 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1435 EXT4_EA_INODE_FL); 1436 if (!IS_ERR(ea_inode)) { 1437 ea_inode->i_op = &ext4_file_inode_operations; 1438 ea_inode->i_fop = &ext4_file_operations; 1439 ext4_set_aops(ea_inode); 1440 ext4_xattr_inode_set_class(ea_inode); 1441 unlock_new_inode(ea_inode); 1442 ext4_xattr_inode_set_ref(ea_inode, 1); 1443 ext4_xattr_inode_set_hash(ea_inode, hash); 1444 err = ext4_mark_inode_dirty(handle, ea_inode); 1445 if (!err) 1446 err = ext4_inode_attach_jinode(ea_inode); 1447 if (err) { 1448 iput(ea_inode); 1449 return ERR_PTR(err); 1450 } 1451 1452 /* 1453 * Xattr inodes are shared therefore quota charging is performed 1454 * at a higher level. 1455 */ 1456 dquot_free_inode(ea_inode); 1457 dquot_drop(ea_inode); 1458 inode_lock(ea_inode); 1459 ea_inode->i_flags |= S_NOQUOTA; 1460 inode_unlock(ea_inode); 1461 } 1462 1463 return ea_inode; 1464 } 1465 1466 static struct inode * 1467 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1468 size_t value_len, u32 hash) 1469 { 1470 struct inode *ea_inode; 1471 struct mb_cache_entry *ce; 1472 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1473 void *ea_data; 1474 1475 if (!ea_inode_cache) 1476 return NULL; 1477 1478 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1479 if (!ce) 1480 return NULL; 1481 1482 ea_data = ext4_kvmalloc(value_len, GFP_NOFS); 1483 if (!ea_data) { 1484 mb_cache_entry_put(ea_inode_cache, ce); 1485 return NULL; 1486 } 1487 1488 while (ce) { 1489 ea_inode = ext4_iget(inode->i_sb, ce->e_value); 1490 if (!IS_ERR(ea_inode) && 1491 !is_bad_inode(ea_inode) && 1492 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1493 i_size_read(ea_inode) == value_len && 1494 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1495 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1496 value_len) && 1497 !memcmp(value, ea_data, value_len)) { 1498 mb_cache_entry_touch(ea_inode_cache, ce); 1499 mb_cache_entry_put(ea_inode_cache, ce); 1500 kvfree(ea_data); 1501 return ea_inode; 1502 } 1503 1504 if (!IS_ERR(ea_inode)) 1505 iput(ea_inode); 1506 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1507 } 1508 kvfree(ea_data); 1509 return NULL; 1510 } 1511 1512 /* 1513 * Add value of the EA in an inode. 1514 */ 1515 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1516 const void *value, size_t value_len, 1517 struct inode **ret_inode) 1518 { 1519 struct inode *ea_inode; 1520 u32 hash; 1521 int err; 1522 1523 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1524 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1525 if (ea_inode) { 1526 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1527 if (err) { 1528 iput(ea_inode); 1529 return err; 1530 } 1531 1532 *ret_inode = ea_inode; 1533 return 0; 1534 } 1535 1536 /* Create an inode for the EA value */ 1537 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1538 if (IS_ERR(ea_inode)) 1539 return PTR_ERR(ea_inode); 1540 1541 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1542 if (err) { 1543 ext4_xattr_inode_dec_ref(handle, ea_inode); 1544 iput(ea_inode); 1545 return err; 1546 } 1547 1548 if (EA_INODE_CACHE(inode)) 1549 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1550 ea_inode->i_ino, true /* reusable */); 1551 1552 *ret_inode = ea_inode; 1553 return 0; 1554 } 1555 1556 /* 1557 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1558 * feature is enabled. 1559 */ 1560 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1561 1562 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1563 struct ext4_xattr_search *s, 1564 handle_t *handle, struct inode *inode, 1565 bool is_block) 1566 { 1567 struct ext4_xattr_entry *last, *next; 1568 struct ext4_xattr_entry *here = s->here; 1569 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1570 int in_inode = i->in_inode; 1571 struct inode *old_ea_inode = NULL; 1572 struct inode *new_ea_inode = NULL; 1573 size_t old_size, new_size; 1574 int ret; 1575 1576 /* Space used by old and new values. */ 1577 old_size = (!s->not_found && !here->e_value_inum) ? 1578 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1579 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1580 1581 /* 1582 * Optimization for the simple case when old and new values have the 1583 * same padded sizes. Not applicable if external inodes are involved. 1584 */ 1585 if (new_size && new_size == old_size) { 1586 size_t offs = le16_to_cpu(here->e_value_offs); 1587 void *val = s->base + offs; 1588 1589 here->e_value_size = cpu_to_le32(i->value_len); 1590 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1591 memset(val, 0, new_size); 1592 } else { 1593 memcpy(val, i->value, i->value_len); 1594 /* Clear padding bytes. */ 1595 memset(val + i->value_len, 0, new_size - i->value_len); 1596 } 1597 goto update_hash; 1598 } 1599 1600 /* Compute min_offs and last. */ 1601 last = s->first; 1602 for (; !IS_LAST_ENTRY(last); last = next) { 1603 next = EXT4_XATTR_NEXT(last); 1604 if ((void *)next >= s->end) { 1605 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 1606 ret = -EFSCORRUPTED; 1607 goto out; 1608 } 1609 if (!last->e_value_inum && last->e_value_size) { 1610 size_t offs = le16_to_cpu(last->e_value_offs); 1611 if (offs < min_offs) 1612 min_offs = offs; 1613 } 1614 } 1615 1616 /* Check whether we have enough space. */ 1617 if (i->value) { 1618 size_t free; 1619 1620 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1621 if (!s->not_found) 1622 free += EXT4_XATTR_LEN(name_len) + old_size; 1623 1624 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1625 ret = -ENOSPC; 1626 goto out; 1627 } 1628 1629 /* 1630 * If storing the value in an external inode is an option, 1631 * reserve space for xattr entries/names in the external 1632 * attribute block so that a long value does not occupy the 1633 * whole space and prevent futher entries being added. 1634 */ 1635 if (ext4_has_feature_ea_inode(inode->i_sb) && 1636 new_size && is_block && 1637 (min_offs + old_size - new_size) < 1638 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1639 ret = -ENOSPC; 1640 goto out; 1641 } 1642 } 1643 1644 /* 1645 * Getting access to old and new ea inodes is subject to failures. 1646 * Finish that work before doing any modifications to the xattr data. 1647 */ 1648 if (!s->not_found && here->e_value_inum) { 1649 ret = ext4_xattr_inode_iget(inode, 1650 le32_to_cpu(here->e_value_inum), 1651 le32_to_cpu(here->e_hash), 1652 &old_ea_inode); 1653 if (ret) { 1654 old_ea_inode = NULL; 1655 goto out; 1656 } 1657 } 1658 if (i->value && in_inode) { 1659 WARN_ON_ONCE(!i->value_len); 1660 1661 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1662 if (ret) 1663 goto out; 1664 1665 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1666 i->value_len, 1667 &new_ea_inode); 1668 if (ret) { 1669 new_ea_inode = NULL; 1670 ext4_xattr_inode_free_quota(inode, NULL, i->value_len); 1671 goto out; 1672 } 1673 } 1674 1675 if (old_ea_inode) { 1676 /* We are ready to release ref count on the old_ea_inode. */ 1677 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1678 if (ret) { 1679 /* Release newly required ref count on new_ea_inode. */ 1680 if (new_ea_inode) { 1681 int err; 1682 1683 err = ext4_xattr_inode_dec_ref(handle, 1684 new_ea_inode); 1685 if (err) 1686 ext4_warning_inode(new_ea_inode, 1687 "dec ref new_ea_inode err=%d", 1688 err); 1689 ext4_xattr_inode_free_quota(inode, new_ea_inode, 1690 i->value_len); 1691 } 1692 goto out; 1693 } 1694 1695 ext4_xattr_inode_free_quota(inode, old_ea_inode, 1696 le32_to_cpu(here->e_value_size)); 1697 } 1698 1699 /* No failures allowed past this point. */ 1700 1701 if (!s->not_found && here->e_value_size && here->e_value_offs) { 1702 /* Remove the old value. */ 1703 void *first_val = s->base + min_offs; 1704 size_t offs = le16_to_cpu(here->e_value_offs); 1705 void *val = s->base + offs; 1706 1707 memmove(first_val + old_size, first_val, val - first_val); 1708 memset(first_val, 0, old_size); 1709 min_offs += old_size; 1710 1711 /* Adjust all value offsets. */ 1712 last = s->first; 1713 while (!IS_LAST_ENTRY(last)) { 1714 size_t o = le16_to_cpu(last->e_value_offs); 1715 1716 if (!last->e_value_inum && 1717 last->e_value_size && o < offs) 1718 last->e_value_offs = cpu_to_le16(o + old_size); 1719 last = EXT4_XATTR_NEXT(last); 1720 } 1721 } 1722 1723 if (!i->value) { 1724 /* Remove old name. */ 1725 size_t size = EXT4_XATTR_LEN(name_len); 1726 1727 last = ENTRY((void *)last - size); 1728 memmove(here, (void *)here + size, 1729 (void *)last - (void *)here + sizeof(__u32)); 1730 memset(last, 0, size); 1731 } else if (s->not_found) { 1732 /* Insert new name. */ 1733 size_t size = EXT4_XATTR_LEN(name_len); 1734 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1735 1736 memmove((void *)here + size, here, rest); 1737 memset(here, 0, size); 1738 here->e_name_index = i->name_index; 1739 here->e_name_len = name_len; 1740 memcpy(here->e_name, i->name, name_len); 1741 } else { 1742 /* This is an update, reset value info. */ 1743 here->e_value_inum = 0; 1744 here->e_value_offs = 0; 1745 here->e_value_size = 0; 1746 } 1747 1748 if (i->value) { 1749 /* Insert new value. */ 1750 if (in_inode) { 1751 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1752 } else if (i->value_len) { 1753 void *val = s->base + min_offs - new_size; 1754 1755 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1756 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1757 memset(val, 0, new_size); 1758 } else { 1759 memcpy(val, i->value, i->value_len); 1760 /* Clear padding bytes. */ 1761 memset(val + i->value_len, 0, 1762 new_size - i->value_len); 1763 } 1764 } 1765 here->e_value_size = cpu_to_le32(i->value_len); 1766 } 1767 1768 update_hash: 1769 if (i->value) { 1770 __le32 hash = 0; 1771 1772 /* Entry hash calculation. */ 1773 if (in_inode) { 1774 __le32 crc32c_hash; 1775 1776 /* 1777 * Feed crc32c hash instead of the raw value for entry 1778 * hash calculation. This is to avoid walking 1779 * potentially long value buffer again. 1780 */ 1781 crc32c_hash = cpu_to_le32( 1782 ext4_xattr_inode_get_hash(new_ea_inode)); 1783 hash = ext4_xattr_hash_entry(here->e_name, 1784 here->e_name_len, 1785 &crc32c_hash, 1); 1786 } else if (is_block) { 1787 __le32 *value = s->base + le16_to_cpu( 1788 here->e_value_offs); 1789 1790 hash = ext4_xattr_hash_entry(here->e_name, 1791 here->e_name_len, value, 1792 new_size >> 2); 1793 } 1794 here->e_hash = hash; 1795 } 1796 1797 if (is_block) 1798 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1799 1800 ret = 0; 1801 out: 1802 iput(old_ea_inode); 1803 iput(new_ea_inode); 1804 return ret; 1805 } 1806 1807 struct ext4_xattr_block_find { 1808 struct ext4_xattr_search s; 1809 struct buffer_head *bh; 1810 }; 1811 1812 static int 1813 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1814 struct ext4_xattr_block_find *bs) 1815 { 1816 struct super_block *sb = inode->i_sb; 1817 int error; 1818 1819 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1820 i->name_index, i->name, i->value, (long)i->value_len); 1821 1822 if (EXT4_I(inode)->i_file_acl) { 1823 /* The inode already has an extended attribute block. */ 1824 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl); 1825 error = -EIO; 1826 if (!bs->bh) 1827 goto cleanup; 1828 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1829 atomic_read(&(bs->bh->b_count)), 1830 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1831 error = ext4_xattr_check_block(inode, bs->bh); 1832 if (error) 1833 goto cleanup; 1834 /* Find the named attribute. */ 1835 bs->s.base = BHDR(bs->bh); 1836 bs->s.first = BFIRST(bs->bh); 1837 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1838 bs->s.here = bs->s.first; 1839 error = xattr_find_entry(inode, &bs->s.here, bs->s.end, 1840 i->name_index, i->name, 1); 1841 if (error && error != -ENODATA) 1842 goto cleanup; 1843 bs->s.not_found = error; 1844 } 1845 error = 0; 1846 1847 cleanup: 1848 return error; 1849 } 1850 1851 static int 1852 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1853 struct ext4_xattr_info *i, 1854 struct ext4_xattr_block_find *bs) 1855 { 1856 struct super_block *sb = inode->i_sb; 1857 struct buffer_head *new_bh = NULL; 1858 struct ext4_xattr_search s_copy = bs->s; 1859 struct ext4_xattr_search *s = &s_copy; 1860 struct mb_cache_entry *ce = NULL; 1861 int error = 0; 1862 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1863 struct inode *ea_inode = NULL, *tmp_inode; 1864 size_t old_ea_inode_quota = 0; 1865 unsigned int ea_ino; 1866 1867 1868 #define header(x) ((struct ext4_xattr_header *)(x)) 1869 1870 if (s->base) { 1871 BUFFER_TRACE(bs->bh, "get_write_access"); 1872 error = ext4_journal_get_write_access(handle, bs->bh); 1873 if (error) 1874 goto cleanup; 1875 lock_buffer(bs->bh); 1876 1877 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1878 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1879 1880 /* 1881 * This must happen under buffer lock for 1882 * ext4_xattr_block_set() to reliably detect modified 1883 * block 1884 */ 1885 if (ea_block_cache) 1886 mb_cache_entry_delete(ea_block_cache, hash, 1887 bs->bh->b_blocknr); 1888 ea_bdebug(bs->bh, "modifying in-place"); 1889 error = ext4_xattr_set_entry(i, s, handle, inode, 1890 true /* is_block */); 1891 ext4_xattr_block_csum_set(inode, bs->bh); 1892 unlock_buffer(bs->bh); 1893 if (error == -EFSCORRUPTED) 1894 goto bad_block; 1895 if (!error) 1896 error = ext4_handle_dirty_metadata(handle, 1897 inode, 1898 bs->bh); 1899 if (error) 1900 goto cleanup; 1901 goto inserted; 1902 } else { 1903 int offset = (char *)s->here - bs->bh->b_data; 1904 1905 unlock_buffer(bs->bh); 1906 ea_bdebug(bs->bh, "cloning"); 1907 s->base = kmalloc(bs->bh->b_size, GFP_NOFS); 1908 error = -ENOMEM; 1909 if (s->base == NULL) 1910 goto cleanup; 1911 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); 1912 s->first = ENTRY(header(s->base)+1); 1913 header(s->base)->h_refcount = cpu_to_le32(1); 1914 s->here = ENTRY(s->base + offset); 1915 s->end = s->base + bs->bh->b_size; 1916 1917 /* 1918 * If existing entry points to an xattr inode, we need 1919 * to prevent ext4_xattr_set_entry() from decrementing 1920 * ref count on it because the reference belongs to the 1921 * original block. In this case, make the entry look 1922 * like it has an empty value. 1923 */ 1924 if (!s->not_found && s->here->e_value_inum) { 1925 ea_ino = le32_to_cpu(s->here->e_value_inum); 1926 error = ext4_xattr_inode_iget(inode, ea_ino, 1927 le32_to_cpu(s->here->e_hash), 1928 &tmp_inode); 1929 if (error) 1930 goto cleanup; 1931 1932 if (!ext4_test_inode_state(tmp_inode, 1933 EXT4_STATE_LUSTRE_EA_INODE)) { 1934 /* 1935 * Defer quota free call for previous 1936 * inode until success is guaranteed. 1937 */ 1938 old_ea_inode_quota = le32_to_cpu( 1939 s->here->e_value_size); 1940 } 1941 iput(tmp_inode); 1942 1943 s->here->e_value_inum = 0; 1944 s->here->e_value_size = 0; 1945 } 1946 } 1947 } else { 1948 /* Allocate a buffer where we construct the new block. */ 1949 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1950 /* assert(header == s->base) */ 1951 error = -ENOMEM; 1952 if (s->base == NULL) 1953 goto cleanup; 1954 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1955 header(s->base)->h_blocks = cpu_to_le32(1); 1956 header(s->base)->h_refcount = cpu_to_le32(1); 1957 s->first = ENTRY(header(s->base)+1); 1958 s->here = ENTRY(header(s->base)+1); 1959 s->end = s->base + sb->s_blocksize; 1960 } 1961 1962 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1963 if (error == -EFSCORRUPTED) 1964 goto bad_block; 1965 if (error) 1966 goto cleanup; 1967 1968 if (i->value && s->here->e_value_inum) { 1969 /* 1970 * A ref count on ea_inode has been taken as part of the call to 1971 * ext4_xattr_set_entry() above. We would like to drop this 1972 * extra ref but we have to wait until the xattr block is 1973 * initialized and has its own ref count on the ea_inode. 1974 */ 1975 ea_ino = le32_to_cpu(s->here->e_value_inum); 1976 error = ext4_xattr_inode_iget(inode, ea_ino, 1977 le32_to_cpu(s->here->e_hash), 1978 &ea_inode); 1979 if (error) { 1980 ea_inode = NULL; 1981 goto cleanup; 1982 } 1983 } 1984 1985 inserted: 1986 if (!IS_LAST_ENTRY(s->first)) { 1987 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 1988 &ce); 1989 if (new_bh) { 1990 /* We found an identical block in the cache. */ 1991 if (new_bh == bs->bh) 1992 ea_bdebug(new_bh, "keeping"); 1993 else { 1994 u32 ref; 1995 1996 WARN_ON_ONCE(dquot_initialize_needed(inode)); 1997 1998 /* The old block is released after updating 1999 the inode. */ 2000 error = dquot_alloc_block(inode, 2001 EXT4_C2B(EXT4_SB(sb), 1)); 2002 if (error) 2003 goto cleanup; 2004 BUFFER_TRACE(new_bh, "get_write_access"); 2005 error = ext4_journal_get_write_access(handle, 2006 new_bh); 2007 if (error) 2008 goto cleanup_dquot; 2009 lock_buffer(new_bh); 2010 /* 2011 * We have to be careful about races with 2012 * freeing, rehashing or adding references to 2013 * xattr block. Once we hold buffer lock xattr 2014 * block's state is stable so we can check 2015 * whether the block got freed / rehashed or 2016 * not. Since we unhash mbcache entry under 2017 * buffer lock when freeing / rehashing xattr 2018 * block, checking whether entry is still 2019 * hashed is reliable. Same rules hold for 2020 * e_reusable handling. 2021 */ 2022 if (hlist_bl_unhashed(&ce->e_hash_list) || 2023 !ce->e_reusable) { 2024 /* 2025 * Undo everything and check mbcache 2026 * again. 2027 */ 2028 unlock_buffer(new_bh); 2029 dquot_free_block(inode, 2030 EXT4_C2B(EXT4_SB(sb), 2031 1)); 2032 brelse(new_bh); 2033 mb_cache_entry_put(ea_block_cache, ce); 2034 ce = NULL; 2035 new_bh = NULL; 2036 goto inserted; 2037 } 2038 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 2039 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 2040 if (ref >= EXT4_XATTR_REFCOUNT_MAX) 2041 ce->e_reusable = 0; 2042 ea_bdebug(new_bh, "reusing; refcount now=%d", 2043 ref); 2044 ext4_xattr_block_csum_set(inode, new_bh); 2045 unlock_buffer(new_bh); 2046 error = ext4_handle_dirty_metadata(handle, 2047 inode, 2048 new_bh); 2049 if (error) 2050 goto cleanup_dquot; 2051 } 2052 mb_cache_entry_touch(ea_block_cache, ce); 2053 mb_cache_entry_put(ea_block_cache, ce); 2054 ce = NULL; 2055 } else if (bs->bh && s->base == bs->bh->b_data) { 2056 /* We were modifying this block in-place. */ 2057 ea_bdebug(bs->bh, "keeping this block"); 2058 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 2059 new_bh = bs->bh; 2060 get_bh(new_bh); 2061 } else { 2062 /* We need to allocate a new block */ 2063 ext4_fsblk_t goal, block; 2064 2065 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2066 2067 goal = ext4_group_first_block_no(sb, 2068 EXT4_I(inode)->i_block_group); 2069 2070 /* non-extent files can't have physical blocks past 2^32 */ 2071 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2072 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; 2073 2074 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2075 NULL, &error); 2076 if (error) 2077 goto cleanup; 2078 2079 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2080 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); 2081 2082 ea_idebug(inode, "creating block %llu", 2083 (unsigned long long)block); 2084 2085 new_bh = sb_getblk(sb, block); 2086 if (unlikely(!new_bh)) { 2087 error = -ENOMEM; 2088 getblk_failed: 2089 ext4_free_blocks(handle, inode, NULL, block, 1, 2090 EXT4_FREE_BLOCKS_METADATA); 2091 goto cleanup; 2092 } 2093 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2094 ENTRY(header(s->base)+1)); 2095 if (error) 2096 goto getblk_failed; 2097 if (ea_inode) { 2098 /* Drop the extra ref on ea_inode. */ 2099 error = ext4_xattr_inode_dec_ref(handle, 2100 ea_inode); 2101 if (error) 2102 ext4_warning_inode(ea_inode, 2103 "dec ref error=%d", 2104 error); 2105 iput(ea_inode); 2106 ea_inode = NULL; 2107 } 2108 2109 lock_buffer(new_bh); 2110 error = ext4_journal_get_create_access(handle, new_bh); 2111 if (error) { 2112 unlock_buffer(new_bh); 2113 error = -EIO; 2114 goto getblk_failed; 2115 } 2116 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2117 ext4_xattr_block_csum_set(inode, new_bh); 2118 set_buffer_uptodate(new_bh); 2119 unlock_buffer(new_bh); 2120 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2121 error = ext4_handle_dirty_metadata(handle, inode, 2122 new_bh); 2123 if (error) 2124 goto cleanup; 2125 } 2126 } 2127 2128 if (old_ea_inode_quota) 2129 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota); 2130 2131 /* Update the inode. */ 2132 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2133 2134 /* Drop the previous xattr block. */ 2135 if (bs->bh && bs->bh != new_bh) { 2136 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2137 2138 ext4_xattr_release_block(handle, inode, bs->bh, 2139 &ea_inode_array, 2140 0 /* extra_credits */); 2141 ext4_xattr_inode_array_free(ea_inode_array); 2142 } 2143 error = 0; 2144 2145 cleanup: 2146 if (ea_inode) { 2147 int error2; 2148 2149 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2150 if (error2) 2151 ext4_warning_inode(ea_inode, "dec ref error=%d", 2152 error2); 2153 2154 /* If there was an error, revert the quota charge. */ 2155 if (error) 2156 ext4_xattr_inode_free_quota(inode, ea_inode, 2157 i_size_read(ea_inode)); 2158 iput(ea_inode); 2159 } 2160 if (ce) 2161 mb_cache_entry_put(ea_block_cache, ce); 2162 brelse(new_bh); 2163 if (!(bs->bh && s->base == bs->bh->b_data)) 2164 kfree(s->base); 2165 2166 return error; 2167 2168 cleanup_dquot: 2169 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2170 goto cleanup; 2171 2172 bad_block: 2173 EXT4_ERROR_INODE(inode, "bad block %llu", 2174 EXT4_I(inode)->i_file_acl); 2175 goto cleanup; 2176 2177 #undef header 2178 } 2179 2180 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2181 struct ext4_xattr_ibody_find *is) 2182 { 2183 struct ext4_xattr_ibody_header *header; 2184 struct ext4_inode *raw_inode; 2185 int error; 2186 2187 if (EXT4_I(inode)->i_extra_isize == 0) 2188 return 0; 2189 raw_inode = ext4_raw_inode(&is->iloc); 2190 header = IHDR(inode, raw_inode); 2191 is->s.base = is->s.first = IFIRST(header); 2192 is->s.here = is->s.first; 2193 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2194 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2195 error = xattr_check_inode(inode, header, is->s.end); 2196 if (error) 2197 return error; 2198 /* Find the named attribute. */ 2199 error = xattr_find_entry(inode, &is->s.here, is->s.end, 2200 i->name_index, i->name, 0); 2201 if (error && error != -ENODATA) 2202 return error; 2203 is->s.not_found = error; 2204 } 2205 return 0; 2206 } 2207 2208 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 2209 struct ext4_xattr_info *i, 2210 struct ext4_xattr_ibody_find *is) 2211 { 2212 struct ext4_xattr_ibody_header *header; 2213 struct ext4_xattr_search *s = &is->s; 2214 int error; 2215 2216 if (EXT4_I(inode)->i_extra_isize == 0) 2217 return -ENOSPC; 2218 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2219 if (error) 2220 return error; 2221 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2222 if (!IS_LAST_ENTRY(s->first)) { 2223 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2224 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2225 } else { 2226 header->h_magic = cpu_to_le32(0); 2227 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2228 } 2229 return 0; 2230 } 2231 2232 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2233 struct ext4_xattr_info *i, 2234 struct ext4_xattr_ibody_find *is) 2235 { 2236 struct ext4_xattr_ibody_header *header; 2237 struct ext4_xattr_search *s = &is->s; 2238 int error; 2239 2240 if (EXT4_I(inode)->i_extra_isize == 0) 2241 return -ENOSPC; 2242 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2243 if (error) 2244 return error; 2245 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2246 if (!IS_LAST_ENTRY(s->first)) { 2247 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2248 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2249 } else { 2250 header->h_magic = cpu_to_le32(0); 2251 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2252 } 2253 return 0; 2254 } 2255 2256 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2257 struct ext4_xattr_info *i) 2258 { 2259 void *value; 2260 2261 /* When e_value_inum is set the value is stored externally. */ 2262 if (s->here->e_value_inum) 2263 return 0; 2264 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2265 return 0; 2266 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2267 return !memcmp(value, i->value, i->value_len); 2268 } 2269 2270 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2271 { 2272 struct buffer_head *bh; 2273 int error; 2274 2275 if (!EXT4_I(inode)->i_file_acl) 2276 return NULL; 2277 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 2278 if (!bh) 2279 return ERR_PTR(-EIO); 2280 error = ext4_xattr_check_block(inode, bh); 2281 if (error) { 2282 brelse(bh); 2283 return ERR_PTR(error); 2284 } 2285 return bh; 2286 } 2287 2288 /* 2289 * ext4_xattr_set_handle() 2290 * 2291 * Create, replace or remove an extended attribute for this inode. Value 2292 * is NULL to remove an existing extended attribute, and non-NULL to 2293 * either replace an existing extended attribute, or create a new extended 2294 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2295 * specify that an extended attribute must exist and must not exist 2296 * previous to the call, respectively. 2297 * 2298 * Returns 0, or a negative error number on failure. 2299 */ 2300 int 2301 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2302 const char *name, const void *value, size_t value_len, 2303 int flags) 2304 { 2305 struct ext4_xattr_info i = { 2306 .name_index = name_index, 2307 .name = name, 2308 .value = value, 2309 .value_len = value_len, 2310 .in_inode = 0, 2311 }; 2312 struct ext4_xattr_ibody_find is = { 2313 .s = { .not_found = -ENODATA, }, 2314 }; 2315 struct ext4_xattr_block_find bs = { 2316 .s = { .not_found = -ENODATA, }, 2317 }; 2318 int no_expand; 2319 int error; 2320 2321 if (!name) 2322 return -EINVAL; 2323 if (strlen(name) > 255) 2324 return -ERANGE; 2325 2326 ext4_write_lock_xattr(inode, &no_expand); 2327 2328 /* Check journal credits under write lock. */ 2329 if (ext4_handle_valid(handle)) { 2330 struct buffer_head *bh; 2331 int credits; 2332 2333 bh = ext4_xattr_get_block(inode); 2334 if (IS_ERR(bh)) { 2335 error = PTR_ERR(bh); 2336 goto cleanup; 2337 } 2338 2339 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2340 value_len, 2341 flags & XATTR_CREATE); 2342 brelse(bh); 2343 2344 if (!ext4_handle_has_enough_credits(handle, credits)) { 2345 error = -ENOSPC; 2346 goto cleanup; 2347 } 2348 } 2349 2350 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2351 if (error) 2352 goto cleanup; 2353 2354 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2355 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2356 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2357 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2358 } 2359 2360 error = ext4_xattr_ibody_find(inode, &i, &is); 2361 if (error) 2362 goto cleanup; 2363 if (is.s.not_found) 2364 error = ext4_xattr_block_find(inode, &i, &bs); 2365 if (error) 2366 goto cleanup; 2367 if (is.s.not_found && bs.s.not_found) { 2368 error = -ENODATA; 2369 if (flags & XATTR_REPLACE) 2370 goto cleanup; 2371 error = 0; 2372 if (!value) 2373 goto cleanup; 2374 } else { 2375 error = -EEXIST; 2376 if (flags & XATTR_CREATE) 2377 goto cleanup; 2378 } 2379 2380 if (!value) { 2381 if (!is.s.not_found) 2382 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2383 else if (!bs.s.not_found) 2384 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2385 } else { 2386 error = 0; 2387 /* Xattr value did not change? Save us some work and bail out */ 2388 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2389 goto cleanup; 2390 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2391 goto cleanup; 2392 2393 if (ext4_has_feature_ea_inode(inode->i_sb) && 2394 (EXT4_XATTR_SIZE(i.value_len) > 2395 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2396 i.in_inode = 1; 2397 retry_inode: 2398 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2399 if (!error && !bs.s.not_found) { 2400 i.value = NULL; 2401 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2402 } else if (error == -ENOSPC) { 2403 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2404 brelse(bs.bh); 2405 bs.bh = NULL; 2406 error = ext4_xattr_block_find(inode, &i, &bs); 2407 if (error) 2408 goto cleanup; 2409 } 2410 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2411 if (!error && !is.s.not_found) { 2412 i.value = NULL; 2413 error = ext4_xattr_ibody_set(handle, inode, &i, 2414 &is); 2415 } else if (error == -ENOSPC) { 2416 /* 2417 * Xattr does not fit in the block, store at 2418 * external inode if possible. 2419 */ 2420 if (ext4_has_feature_ea_inode(inode->i_sb) && 2421 !i.in_inode) { 2422 i.in_inode = 1; 2423 goto retry_inode; 2424 } 2425 } 2426 } 2427 } 2428 if (!error) { 2429 ext4_xattr_update_super_block(handle, inode->i_sb); 2430 inode->i_ctime = current_time(inode); 2431 if (!value) 2432 no_expand = 0; 2433 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2434 /* 2435 * The bh is consumed by ext4_mark_iloc_dirty, even with 2436 * error != 0. 2437 */ 2438 is.iloc.bh = NULL; 2439 if (IS_SYNC(inode)) 2440 ext4_handle_sync(handle); 2441 } 2442 2443 cleanup: 2444 brelse(is.iloc.bh); 2445 brelse(bs.bh); 2446 ext4_write_unlock_xattr(inode, &no_expand); 2447 return error; 2448 } 2449 2450 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2451 bool is_create, int *credits) 2452 { 2453 struct buffer_head *bh; 2454 int err; 2455 2456 *credits = 0; 2457 2458 if (!EXT4_SB(inode->i_sb)->s_journal) 2459 return 0; 2460 2461 down_read(&EXT4_I(inode)->xattr_sem); 2462 2463 bh = ext4_xattr_get_block(inode); 2464 if (IS_ERR(bh)) { 2465 err = PTR_ERR(bh); 2466 } else { 2467 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2468 value_len, is_create); 2469 brelse(bh); 2470 err = 0; 2471 } 2472 2473 up_read(&EXT4_I(inode)->xattr_sem); 2474 return err; 2475 } 2476 2477 /* 2478 * ext4_xattr_set() 2479 * 2480 * Like ext4_xattr_set_handle, but start from an inode. This extended 2481 * attribute modification is a filesystem transaction by itself. 2482 * 2483 * Returns 0, or a negative error number on failure. 2484 */ 2485 int 2486 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2487 const void *value, size_t value_len, int flags) 2488 { 2489 handle_t *handle; 2490 struct super_block *sb = inode->i_sb; 2491 int error, retries = 0; 2492 int credits; 2493 2494 error = dquot_initialize(inode); 2495 if (error) 2496 return error; 2497 2498 retry: 2499 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2500 &credits); 2501 if (error) 2502 return error; 2503 2504 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2505 if (IS_ERR(handle)) { 2506 error = PTR_ERR(handle); 2507 } else { 2508 int error2; 2509 2510 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2511 value, value_len, flags); 2512 error2 = ext4_journal_stop(handle); 2513 if (error == -ENOSPC && 2514 ext4_should_retry_alloc(sb, &retries)) 2515 goto retry; 2516 if (error == 0) 2517 error = error2; 2518 } 2519 2520 return error; 2521 } 2522 2523 /* 2524 * Shift the EA entries in the inode to create space for the increased 2525 * i_extra_isize. 2526 */ 2527 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2528 int value_offs_shift, void *to, 2529 void *from, size_t n) 2530 { 2531 struct ext4_xattr_entry *last = entry; 2532 int new_offs; 2533 2534 /* We always shift xattr headers further thus offsets get lower */ 2535 BUG_ON(value_offs_shift > 0); 2536 2537 /* Adjust the value offsets of the entries */ 2538 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2539 if (!last->e_value_inum && last->e_value_size) { 2540 new_offs = le16_to_cpu(last->e_value_offs) + 2541 value_offs_shift; 2542 last->e_value_offs = cpu_to_le16(new_offs); 2543 } 2544 } 2545 /* Shift the entries by n bytes */ 2546 memmove(to, from, n); 2547 } 2548 2549 /* 2550 * Move xattr pointed to by 'entry' from inode into external xattr block 2551 */ 2552 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2553 struct ext4_inode *raw_inode, 2554 struct ext4_xattr_entry *entry) 2555 { 2556 struct ext4_xattr_ibody_find *is = NULL; 2557 struct ext4_xattr_block_find *bs = NULL; 2558 char *buffer = NULL, *b_entry_name = NULL; 2559 size_t value_size = le32_to_cpu(entry->e_value_size); 2560 struct ext4_xattr_info i = { 2561 .value = NULL, 2562 .value_len = 0, 2563 .name_index = entry->e_name_index, 2564 .in_inode = !!entry->e_value_inum, 2565 }; 2566 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2567 int error; 2568 2569 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2570 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2571 buffer = kmalloc(value_size, GFP_NOFS); 2572 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2573 if (!is || !bs || !buffer || !b_entry_name) { 2574 error = -ENOMEM; 2575 goto out; 2576 } 2577 2578 is->s.not_found = -ENODATA; 2579 bs->s.not_found = -ENODATA; 2580 is->iloc.bh = NULL; 2581 bs->bh = NULL; 2582 2583 /* Save the entry name and the entry value */ 2584 if (entry->e_value_inum) { 2585 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2586 if (error) 2587 goto out; 2588 } else { 2589 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2590 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2591 } 2592 2593 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2594 b_entry_name[entry->e_name_len] = '\0'; 2595 i.name = b_entry_name; 2596 2597 error = ext4_get_inode_loc(inode, &is->iloc); 2598 if (error) 2599 goto out; 2600 2601 error = ext4_xattr_ibody_find(inode, &i, is); 2602 if (error) 2603 goto out; 2604 2605 /* Remove the chosen entry from the inode */ 2606 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2607 if (error) 2608 goto out; 2609 2610 i.value = buffer; 2611 i.value_len = value_size; 2612 error = ext4_xattr_block_find(inode, &i, bs); 2613 if (error) 2614 goto out; 2615 2616 /* Add entry which was removed from the inode into the block */ 2617 error = ext4_xattr_block_set(handle, inode, &i, bs); 2618 if (error) 2619 goto out; 2620 error = 0; 2621 out: 2622 kfree(b_entry_name); 2623 kfree(buffer); 2624 if (is) 2625 brelse(is->iloc.bh); 2626 if (bs) 2627 brelse(bs->bh); 2628 kfree(is); 2629 kfree(bs); 2630 2631 return error; 2632 } 2633 2634 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2635 struct ext4_inode *raw_inode, 2636 int isize_diff, size_t ifree, 2637 size_t bfree, int *total_ino) 2638 { 2639 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2640 struct ext4_xattr_entry *small_entry; 2641 struct ext4_xattr_entry *entry; 2642 struct ext4_xattr_entry *last; 2643 unsigned int entry_size; /* EA entry size */ 2644 unsigned int total_size; /* EA entry size + value size */ 2645 unsigned int min_total_size; 2646 int error; 2647 2648 while (isize_diff > ifree) { 2649 entry = NULL; 2650 small_entry = NULL; 2651 min_total_size = ~0U; 2652 last = IFIRST(header); 2653 /* Find the entry best suited to be pushed into EA block */ 2654 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2655 /* never move system.data out of the inode */ 2656 if ((last->e_name_len == 4) && 2657 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) && 2658 !memcmp(last->e_name, "data", 4)) 2659 continue; 2660 total_size = EXT4_XATTR_LEN(last->e_name_len); 2661 if (!last->e_value_inum) 2662 total_size += EXT4_XATTR_SIZE( 2663 le32_to_cpu(last->e_value_size)); 2664 if (total_size <= bfree && 2665 total_size < min_total_size) { 2666 if (total_size + ifree < isize_diff) { 2667 small_entry = last; 2668 } else { 2669 entry = last; 2670 min_total_size = total_size; 2671 } 2672 } 2673 } 2674 2675 if (entry == NULL) { 2676 if (small_entry == NULL) 2677 return -ENOSPC; 2678 entry = small_entry; 2679 } 2680 2681 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2682 total_size = entry_size; 2683 if (!entry->e_value_inum) 2684 total_size += EXT4_XATTR_SIZE( 2685 le32_to_cpu(entry->e_value_size)); 2686 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2687 entry); 2688 if (error) 2689 return error; 2690 2691 *total_ino -= entry_size; 2692 ifree += total_size; 2693 bfree -= total_size; 2694 } 2695 2696 return 0; 2697 } 2698 2699 /* 2700 * Expand an inode by new_extra_isize bytes when EAs are present. 2701 * Returns 0 on success or negative error number on failure. 2702 */ 2703 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2704 struct ext4_inode *raw_inode, handle_t *handle) 2705 { 2706 struct ext4_xattr_ibody_header *header; 2707 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2708 static unsigned int mnt_count; 2709 size_t min_offs; 2710 size_t ifree, bfree; 2711 int total_ino; 2712 void *base, *end; 2713 int error = 0, tried_min_extra_isize = 0; 2714 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2715 int isize_diff; /* How much do we need to grow i_extra_isize */ 2716 2717 retry: 2718 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2719 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2720 return 0; 2721 2722 header = IHDR(inode, raw_inode); 2723 2724 /* 2725 * Check if enough free space is available in the inode to shift the 2726 * entries ahead by new_extra_isize. 2727 */ 2728 2729 base = IFIRST(header); 2730 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2731 min_offs = end - base; 2732 total_ino = sizeof(struct ext4_xattr_ibody_header); 2733 2734 error = xattr_check_inode(inode, header, end); 2735 if (error) 2736 goto cleanup; 2737 2738 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2739 if (ifree >= isize_diff) 2740 goto shift; 2741 2742 /* 2743 * Enough free space isn't available in the inode, check if 2744 * EA block can hold new_extra_isize bytes. 2745 */ 2746 if (EXT4_I(inode)->i_file_acl) { 2747 struct buffer_head *bh; 2748 2749 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 2750 error = -EIO; 2751 if (!bh) 2752 goto cleanup; 2753 error = ext4_xattr_check_block(inode, bh); 2754 if (error) { 2755 brelse(bh); 2756 goto cleanup; 2757 } 2758 base = BHDR(bh); 2759 end = bh->b_data + bh->b_size; 2760 min_offs = end - base; 2761 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2762 NULL); 2763 brelse(bh); 2764 if (bfree + ifree < isize_diff) { 2765 if (!tried_min_extra_isize && s_min_extra_isize) { 2766 tried_min_extra_isize++; 2767 new_extra_isize = s_min_extra_isize; 2768 goto retry; 2769 } 2770 error = -ENOSPC; 2771 goto cleanup; 2772 } 2773 } else { 2774 bfree = inode->i_sb->s_blocksize; 2775 } 2776 2777 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2778 isize_diff, ifree, bfree, 2779 &total_ino); 2780 if (error) { 2781 if (error == -ENOSPC && !tried_min_extra_isize && 2782 s_min_extra_isize) { 2783 tried_min_extra_isize++; 2784 new_extra_isize = s_min_extra_isize; 2785 goto retry; 2786 } 2787 goto cleanup; 2788 } 2789 shift: 2790 /* Adjust the offsets and shift the remaining entries ahead */ 2791 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2792 - new_extra_isize, (void *)raw_inode + 2793 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2794 (void *)header, total_ino); 2795 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2796 2797 cleanup: 2798 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2799 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2800 inode->i_ino); 2801 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2802 } 2803 return error; 2804 } 2805 2806 #define EIA_INCR 16 /* must be 2^n */ 2807 #define EIA_MASK (EIA_INCR - 1) 2808 2809 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2810 * If @ea_inode_array is new or full it will be grown and the old 2811 * contents copied over. 2812 */ 2813 static int 2814 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2815 struct inode *inode) 2816 { 2817 if (*ea_inode_array == NULL) { 2818 /* 2819 * Start with 15 inodes, so it fits into a power-of-two size. 2820 * If *ea_inode_array is NULL, this is essentially offsetof() 2821 */ 2822 (*ea_inode_array) = 2823 kmalloc(offsetof(struct ext4_xattr_inode_array, 2824 inodes[EIA_MASK]), 2825 GFP_NOFS); 2826 if (*ea_inode_array == NULL) 2827 return -ENOMEM; 2828 (*ea_inode_array)->count = 0; 2829 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2830 /* expand the array once all 15 + n * 16 slots are full */ 2831 struct ext4_xattr_inode_array *new_array = NULL; 2832 int count = (*ea_inode_array)->count; 2833 2834 /* if new_array is NULL, this is essentially offsetof() */ 2835 new_array = kmalloc( 2836 offsetof(struct ext4_xattr_inode_array, 2837 inodes[count + EIA_INCR]), 2838 GFP_NOFS); 2839 if (new_array == NULL) 2840 return -ENOMEM; 2841 memcpy(new_array, *ea_inode_array, 2842 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2843 kfree(*ea_inode_array); 2844 *ea_inode_array = new_array; 2845 } 2846 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2847 return 0; 2848 } 2849 2850 /* 2851 * ext4_xattr_delete_inode() 2852 * 2853 * Free extended attribute resources associated with this inode. Traverse 2854 * all entries and decrement reference on any xattr inodes associated with this 2855 * inode. This is called immediately before an inode is freed. We have exclusive 2856 * access to the inode. If an orphan inode is deleted it will also release its 2857 * references on xattr block and xattr inodes. 2858 */ 2859 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2860 struct ext4_xattr_inode_array **ea_inode_array, 2861 int extra_credits) 2862 { 2863 struct buffer_head *bh = NULL; 2864 struct ext4_xattr_ibody_header *header; 2865 struct ext4_iloc iloc = { .bh = NULL }; 2866 struct ext4_xattr_entry *entry; 2867 struct inode *ea_inode; 2868 int error; 2869 2870 error = ext4_xattr_ensure_credits(handle, inode, extra_credits, 2871 NULL /* bh */, 2872 false /* dirty */, 2873 false /* block_csum */); 2874 if (error) { 2875 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2876 goto cleanup; 2877 } 2878 2879 if (ext4_has_feature_ea_inode(inode->i_sb) && 2880 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2881 2882 error = ext4_get_inode_loc(inode, &iloc); 2883 if (error) { 2884 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2885 goto cleanup; 2886 } 2887 2888 error = ext4_journal_get_write_access(handle, iloc.bh); 2889 if (error) { 2890 EXT4_ERROR_INODE(inode, "write access (error %d)", 2891 error); 2892 goto cleanup; 2893 } 2894 2895 header = IHDR(inode, ext4_raw_inode(&iloc)); 2896 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2897 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2898 IFIRST(header), 2899 false /* block_csum */, 2900 ea_inode_array, 2901 extra_credits, 2902 false /* skip_quota */); 2903 } 2904 2905 if (EXT4_I(inode)->i_file_acl) { 2906 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); 2907 if (!bh) { 2908 EXT4_ERROR_INODE(inode, "block %llu read error", 2909 EXT4_I(inode)->i_file_acl); 2910 error = -EIO; 2911 goto cleanup; 2912 } 2913 error = ext4_xattr_check_block(inode, bh); 2914 if (error) 2915 goto cleanup; 2916 2917 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2918 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2919 entry = EXT4_XATTR_NEXT(entry)) { 2920 if (!entry->e_value_inum) 2921 continue; 2922 error = ext4_xattr_inode_iget(inode, 2923 le32_to_cpu(entry->e_value_inum), 2924 le32_to_cpu(entry->e_hash), 2925 &ea_inode); 2926 if (error) 2927 continue; 2928 ext4_xattr_inode_free_quota(inode, ea_inode, 2929 le32_to_cpu(entry->e_value_size)); 2930 iput(ea_inode); 2931 } 2932 2933 } 2934 2935 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2936 extra_credits); 2937 /* 2938 * Update i_file_acl value in the same transaction that releases 2939 * block. 2940 */ 2941 EXT4_I(inode)->i_file_acl = 0; 2942 error = ext4_mark_inode_dirty(handle, inode); 2943 if (error) { 2944 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2945 error); 2946 goto cleanup; 2947 } 2948 } 2949 error = 0; 2950 cleanup: 2951 brelse(iloc.bh); 2952 brelse(bh); 2953 return error; 2954 } 2955 2956 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2957 { 2958 int idx; 2959 2960 if (ea_inode_array == NULL) 2961 return; 2962 2963 for (idx = 0; idx < ea_inode_array->count; ++idx) 2964 iput(ea_inode_array->inodes[idx]); 2965 kfree(ea_inode_array); 2966 } 2967 2968 /* 2969 * ext4_xattr_block_cache_insert() 2970 * 2971 * Create a new entry in the extended attribute block cache, and insert 2972 * it unless such an entry is already in the cache. 2973 * 2974 * Returns 0, or a negative error number on failure. 2975 */ 2976 static void 2977 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2978 struct buffer_head *bh) 2979 { 2980 struct ext4_xattr_header *header = BHDR(bh); 2981 __u32 hash = le32_to_cpu(header->h_hash); 2982 int reusable = le32_to_cpu(header->h_refcount) < 2983 EXT4_XATTR_REFCOUNT_MAX; 2984 int error; 2985 2986 if (!ea_block_cache) 2987 return; 2988 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2989 bh->b_blocknr, reusable); 2990 if (error) { 2991 if (error == -EBUSY) 2992 ea_bdebug(bh, "already in cache"); 2993 } else 2994 ea_bdebug(bh, "inserting [%x]", (int)hash); 2995 } 2996 2997 /* 2998 * ext4_xattr_cmp() 2999 * 3000 * Compare two extended attribute blocks for equality. 3001 * 3002 * Returns 0 if the blocks are equal, 1 if they differ, and 3003 * a negative error number on errors. 3004 */ 3005 static int 3006 ext4_xattr_cmp(struct ext4_xattr_header *header1, 3007 struct ext4_xattr_header *header2) 3008 { 3009 struct ext4_xattr_entry *entry1, *entry2; 3010 3011 entry1 = ENTRY(header1+1); 3012 entry2 = ENTRY(header2+1); 3013 while (!IS_LAST_ENTRY(entry1)) { 3014 if (IS_LAST_ENTRY(entry2)) 3015 return 1; 3016 if (entry1->e_hash != entry2->e_hash || 3017 entry1->e_name_index != entry2->e_name_index || 3018 entry1->e_name_len != entry2->e_name_len || 3019 entry1->e_value_size != entry2->e_value_size || 3020 entry1->e_value_inum != entry2->e_value_inum || 3021 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 3022 return 1; 3023 if (!entry1->e_value_inum && 3024 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 3025 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 3026 le32_to_cpu(entry1->e_value_size))) 3027 return 1; 3028 3029 entry1 = EXT4_XATTR_NEXT(entry1); 3030 entry2 = EXT4_XATTR_NEXT(entry2); 3031 } 3032 if (!IS_LAST_ENTRY(entry2)) 3033 return 1; 3034 return 0; 3035 } 3036 3037 /* 3038 * ext4_xattr_block_cache_find() 3039 * 3040 * Find an identical extended attribute block. 3041 * 3042 * Returns a pointer to the block found, or NULL if such a block was 3043 * not found or an error occurred. 3044 */ 3045 static struct buffer_head * 3046 ext4_xattr_block_cache_find(struct inode *inode, 3047 struct ext4_xattr_header *header, 3048 struct mb_cache_entry **pce) 3049 { 3050 __u32 hash = le32_to_cpu(header->h_hash); 3051 struct mb_cache_entry *ce; 3052 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 3053 3054 if (!ea_block_cache) 3055 return NULL; 3056 if (!header->h_hash) 3057 return NULL; /* never share */ 3058 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 3059 ce = mb_cache_entry_find_first(ea_block_cache, hash); 3060 while (ce) { 3061 struct buffer_head *bh; 3062 3063 bh = sb_bread(inode->i_sb, ce->e_value); 3064 if (!bh) { 3065 EXT4_ERROR_INODE(inode, "block %lu read error", 3066 (unsigned long)ce->e_value); 3067 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 3068 *pce = ce; 3069 return bh; 3070 } 3071 brelse(bh); 3072 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3073 } 3074 return NULL; 3075 } 3076 3077 #define NAME_HASH_SHIFT 5 3078 #define VALUE_HASH_SHIFT 16 3079 3080 /* 3081 * ext4_xattr_hash_entry() 3082 * 3083 * Compute the hash of an extended attribute. 3084 */ 3085 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3086 size_t value_count) 3087 { 3088 __u32 hash = 0; 3089 3090 while (name_len--) { 3091 hash = (hash << NAME_HASH_SHIFT) ^ 3092 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3093 *name++; 3094 } 3095 while (value_count--) { 3096 hash = (hash << VALUE_HASH_SHIFT) ^ 3097 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3098 le32_to_cpu(*value++); 3099 } 3100 return cpu_to_le32(hash); 3101 } 3102 3103 #undef NAME_HASH_SHIFT 3104 #undef VALUE_HASH_SHIFT 3105 3106 #define BLOCK_HASH_SHIFT 16 3107 3108 /* 3109 * ext4_xattr_rehash() 3110 * 3111 * Re-compute the extended attribute hash value after an entry has changed. 3112 */ 3113 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3114 { 3115 struct ext4_xattr_entry *here; 3116 __u32 hash = 0; 3117 3118 here = ENTRY(header+1); 3119 while (!IS_LAST_ENTRY(here)) { 3120 if (!here->e_hash) { 3121 /* Block is not shared if an entry's hash value == 0 */ 3122 hash = 0; 3123 break; 3124 } 3125 hash = (hash << BLOCK_HASH_SHIFT) ^ 3126 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3127 le32_to_cpu(here->e_hash); 3128 here = EXT4_XATTR_NEXT(here); 3129 } 3130 header->h_hash = cpu_to_le32(hash); 3131 } 3132 3133 #undef BLOCK_HASH_SHIFT 3134 3135 #define HASH_BUCKET_BITS 10 3136 3137 struct mb_cache * 3138 ext4_xattr_create_cache(void) 3139 { 3140 return mb_cache_create(HASH_BUCKET_BITS); 3141 } 3142 3143 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3144 { 3145 if (cache) 3146 mb_cache_destroy(cache); 3147 } 3148 3149