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 [EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler, 97 }; 98 99 const struct xattr_handler *ext4_xattr_handlers[] = { 100 &ext4_xattr_user_handler, 101 &ext4_xattr_trusted_handler, 102 #ifdef CONFIG_EXT4_FS_POSIX_ACL 103 &posix_acl_access_xattr_handler, 104 &posix_acl_default_xattr_handler, 105 #endif 106 #ifdef CONFIG_EXT4_FS_SECURITY 107 &ext4_xattr_security_handler, 108 #endif 109 &ext4_xattr_hurd_handler, 110 NULL 111 }; 112 113 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ 114 inode->i_sb->s_fs_info)->s_ea_block_cache) 115 116 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \ 117 inode->i_sb->s_fs_info)->s_ea_inode_cache) 118 119 static int 120 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 121 struct inode *inode); 122 123 #ifdef CONFIG_LOCKDEP 124 void ext4_xattr_inode_set_class(struct inode *ea_inode) 125 { 126 lockdep_set_subclass(&ea_inode->i_rwsem, 1); 127 } 128 #endif 129 130 static __le32 ext4_xattr_block_csum(struct inode *inode, 131 sector_t block_nr, 132 struct ext4_xattr_header *hdr) 133 { 134 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 135 __u32 csum; 136 __le64 dsk_block_nr = cpu_to_le64(block_nr); 137 __u32 dummy_csum = 0; 138 int offset = offsetof(struct ext4_xattr_header, h_checksum); 139 140 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr, 141 sizeof(dsk_block_nr)); 142 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset); 143 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 144 offset += sizeof(dummy_csum); 145 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset, 146 EXT4_BLOCK_SIZE(inode->i_sb) - offset); 147 148 return cpu_to_le32(csum); 149 } 150 151 static int ext4_xattr_block_csum_verify(struct inode *inode, 152 struct buffer_head *bh) 153 { 154 struct ext4_xattr_header *hdr = BHDR(bh); 155 int ret = 1; 156 157 if (ext4_has_metadata_csum(inode->i_sb)) { 158 lock_buffer(bh); 159 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, 160 bh->b_blocknr, hdr)); 161 unlock_buffer(bh); 162 } 163 return ret; 164 } 165 166 static void ext4_xattr_block_csum_set(struct inode *inode, 167 struct buffer_head *bh) 168 { 169 if (ext4_has_metadata_csum(inode->i_sb)) 170 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, 171 bh->b_blocknr, BHDR(bh)); 172 } 173 174 static inline const struct xattr_handler * 175 ext4_xattr_handler(int name_index) 176 { 177 const struct xattr_handler *handler = NULL; 178 179 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) 180 handler = ext4_xattr_handler_map[name_index]; 181 return handler; 182 } 183 184 static int 185 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, 186 void *value_start) 187 { 188 struct ext4_xattr_entry *e = entry; 189 190 /* Find the end of the names list */ 191 while (!IS_LAST_ENTRY(e)) { 192 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); 193 if ((void *)next >= end) 194 return -EFSCORRUPTED; 195 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) 196 return -EFSCORRUPTED; 197 e = next; 198 } 199 200 /* Check the values */ 201 while (!IS_LAST_ENTRY(entry)) { 202 u32 size = le32_to_cpu(entry->e_value_size); 203 204 if (size > EXT4_XATTR_SIZE_MAX) 205 return -EFSCORRUPTED; 206 207 if (size != 0 && entry->e_value_inum == 0) { 208 u16 offs = le16_to_cpu(entry->e_value_offs); 209 void *value; 210 211 /* 212 * The value cannot overlap the names, and the value 213 * with padding cannot extend beyond 'end'. Check both 214 * the padded and unpadded sizes, since the size may 215 * overflow to 0 when adding padding. 216 */ 217 if (offs > end - value_start) 218 return -EFSCORRUPTED; 219 value = value_start + offs; 220 if (value < (void *)e + sizeof(u32) || 221 size > end - value || 222 EXT4_XATTR_SIZE(size) > end - value) 223 return -EFSCORRUPTED; 224 } 225 entry = EXT4_XATTR_NEXT(entry); 226 } 227 228 return 0; 229 } 230 231 static inline int 232 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, 233 const char *function, unsigned int line) 234 { 235 int error = -EFSCORRUPTED; 236 237 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || 238 BHDR(bh)->h_blocks != cpu_to_le32(1)) 239 goto errout; 240 if (buffer_verified(bh)) 241 return 0; 242 243 error = -EFSBADCRC; 244 if (!ext4_xattr_block_csum_verify(inode, bh)) 245 goto errout; 246 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, 247 bh->b_data); 248 errout: 249 if (error) 250 __ext4_error_inode(inode, function, line, 0, -error, 251 "corrupted xattr block %llu", 252 (unsigned long long) bh->b_blocknr); 253 else 254 set_buffer_verified(bh); 255 return error; 256 } 257 258 #define ext4_xattr_check_block(inode, bh) \ 259 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) 260 261 262 static int 263 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, 264 void *end, const char *function, unsigned int line) 265 { 266 int error = -EFSCORRUPTED; 267 268 if (end - (void *)header < sizeof(*header) + sizeof(u32) || 269 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC))) 270 goto errout; 271 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header)); 272 errout: 273 if (error) 274 __ext4_error_inode(inode, function, line, 0, -error, 275 "corrupted in-inode xattr"); 276 return error; 277 } 278 279 #define xattr_check_inode(inode, header, end) \ 280 __xattr_check_inode((inode), (header), (end), __func__, __LINE__) 281 282 static int 283 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, 284 void *end, int name_index, const char *name, int sorted) 285 { 286 struct ext4_xattr_entry *entry, *next; 287 size_t name_len; 288 int cmp = 1; 289 290 if (name == NULL) 291 return -EINVAL; 292 name_len = strlen(name); 293 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { 294 next = EXT4_XATTR_NEXT(entry); 295 if ((void *) next >= end) { 296 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 297 return -EFSCORRUPTED; 298 } 299 cmp = name_index - entry->e_name_index; 300 if (!cmp) 301 cmp = name_len - entry->e_name_len; 302 if (!cmp) 303 cmp = memcmp(name, entry->e_name, name_len); 304 if (cmp <= 0 && (sorted || cmp == 0)) 305 break; 306 } 307 *pentry = entry; 308 return cmp ? -ENODATA : 0; 309 } 310 311 static u32 312 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size) 313 { 314 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size); 315 } 316 317 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode) 318 { 319 return ((u64)ea_inode->i_ctime.tv_sec << 32) | 320 (u32) inode_peek_iversion_raw(ea_inode); 321 } 322 323 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count) 324 { 325 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32); 326 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff); 327 } 328 329 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode) 330 { 331 return (u32)ea_inode->i_atime.tv_sec; 332 } 333 334 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash) 335 { 336 ea_inode->i_atime.tv_sec = hash; 337 } 338 339 /* 340 * Read the EA value from an inode. 341 */ 342 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) 343 { 344 int blocksize = 1 << ea_inode->i_blkbits; 345 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits; 346 int tail_size = (size % blocksize) ?: blocksize; 347 struct buffer_head *bhs_inline[8]; 348 struct buffer_head **bhs = bhs_inline; 349 int i, ret; 350 351 if (bh_count > ARRAY_SIZE(bhs_inline)) { 352 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS); 353 if (!bhs) 354 return -ENOMEM; 355 } 356 357 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count, 358 true /* wait */, bhs); 359 if (ret) 360 goto free_bhs; 361 362 for (i = 0; i < bh_count; i++) { 363 /* There shouldn't be any holes in ea_inode. */ 364 if (!bhs[i]) { 365 ret = -EFSCORRUPTED; 366 goto put_bhs; 367 } 368 memcpy((char *)buf + blocksize * i, bhs[i]->b_data, 369 i < bh_count - 1 ? blocksize : tail_size); 370 } 371 ret = 0; 372 put_bhs: 373 for (i = 0; i < bh_count; i++) 374 brelse(bhs[i]); 375 free_bhs: 376 if (bhs != bhs_inline) 377 kfree(bhs); 378 return ret; 379 } 380 381 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec) 382 383 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, 384 u32 ea_inode_hash, struct inode **ea_inode) 385 { 386 struct inode *inode; 387 int err; 388 389 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL); 390 if (IS_ERR(inode)) { 391 err = PTR_ERR(inode); 392 ext4_error(parent->i_sb, 393 "error while reading EA inode %lu err=%d", ea_ino, 394 err); 395 return err; 396 } 397 398 if (is_bad_inode(inode)) { 399 ext4_error(parent->i_sb, 400 "error while reading EA inode %lu is_bad_inode", 401 ea_ino); 402 err = -EIO; 403 goto error; 404 } 405 406 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { 407 ext4_error(parent->i_sb, 408 "EA inode %lu does not have EXT4_EA_INODE_FL flag", 409 ea_ino); 410 err = -EINVAL; 411 goto error; 412 } 413 414 ext4_xattr_inode_set_class(inode); 415 416 /* 417 * Check whether this is an old Lustre-style xattr inode. Lustre 418 * implementation does not have hash validation, rather it has a 419 * backpointer from ea_inode to the parent inode. 420 */ 421 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) && 422 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino && 423 inode->i_generation == parent->i_generation) { 424 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE); 425 ext4_xattr_inode_set_ref(inode, 1); 426 } else { 427 inode_lock(inode); 428 inode->i_flags |= S_NOQUOTA; 429 inode_unlock(inode); 430 } 431 432 *ea_inode = inode; 433 return 0; 434 error: 435 iput(inode); 436 return err; 437 } 438 439 static int 440 ext4_xattr_inode_verify_hashes(struct inode *ea_inode, 441 struct ext4_xattr_entry *entry, void *buffer, 442 size_t size) 443 { 444 u32 hash; 445 446 /* Verify stored hash matches calculated hash. */ 447 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size); 448 if (hash != ext4_xattr_inode_get_hash(ea_inode)) 449 return -EFSCORRUPTED; 450 451 if (entry) { 452 __le32 e_hash, tmp_data; 453 454 /* Verify entry hash. */ 455 tmp_data = cpu_to_le32(hash); 456 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len, 457 &tmp_data, 1); 458 if (e_hash != entry->e_hash) 459 return -EFSCORRUPTED; 460 } 461 return 0; 462 } 463 464 /* 465 * Read xattr value from the EA inode. 466 */ 467 static int 468 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry, 469 void *buffer, size_t size) 470 { 471 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 472 struct inode *ea_inode; 473 int err; 474 475 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum), 476 le32_to_cpu(entry->e_hash), &ea_inode); 477 if (err) { 478 ea_inode = NULL; 479 goto out; 480 } 481 482 if (i_size_read(ea_inode) != size) { 483 ext4_warning_inode(ea_inode, 484 "ea_inode file size=%llu entry size=%zu", 485 i_size_read(ea_inode), size); 486 err = -EFSCORRUPTED; 487 goto out; 488 } 489 490 err = ext4_xattr_inode_read(ea_inode, buffer, size); 491 if (err) 492 goto out; 493 494 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) { 495 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer, 496 size); 497 if (err) { 498 ext4_warning_inode(ea_inode, 499 "EA inode hash validation failed"); 500 goto out; 501 } 502 503 if (ea_inode_cache) 504 mb_cache_entry_create(ea_inode_cache, GFP_NOFS, 505 ext4_xattr_inode_get_hash(ea_inode), 506 ea_inode->i_ino, true /* reusable */); 507 } 508 out: 509 iput(ea_inode); 510 return err; 511 } 512 513 static int 514 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, 515 void *buffer, size_t buffer_size) 516 { 517 struct buffer_head *bh = NULL; 518 struct ext4_xattr_entry *entry; 519 size_t size; 520 void *end; 521 int error; 522 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 523 524 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 525 name_index, name, buffer, (long)buffer_size); 526 527 if (!EXT4_I(inode)->i_file_acl) 528 return -ENODATA; 529 ea_idebug(inode, "reading block %llu", 530 (unsigned long long)EXT4_I(inode)->i_file_acl); 531 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 532 if (IS_ERR(bh)) 533 return PTR_ERR(bh); 534 ea_bdebug(bh, "b_count=%d, refcount=%d", 535 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 536 error = ext4_xattr_check_block(inode, bh); 537 if (error) 538 goto cleanup; 539 ext4_xattr_block_cache_insert(ea_block_cache, bh); 540 entry = BFIRST(bh); 541 end = bh->b_data + bh->b_size; 542 error = xattr_find_entry(inode, &entry, end, name_index, name, 1); 543 if (error) 544 goto cleanup; 545 size = le32_to_cpu(entry->e_value_size); 546 error = -ERANGE; 547 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 548 goto cleanup; 549 if (buffer) { 550 if (size > buffer_size) 551 goto cleanup; 552 if (entry->e_value_inum) { 553 error = ext4_xattr_inode_get(inode, entry, buffer, 554 size); 555 if (error) 556 goto cleanup; 557 } else { 558 u16 offset = le16_to_cpu(entry->e_value_offs); 559 void *p = bh->b_data + offset; 560 561 if (unlikely(p + size > end)) 562 goto cleanup; 563 memcpy(buffer, p, size); 564 } 565 } 566 error = size; 567 568 cleanup: 569 brelse(bh); 570 return error; 571 } 572 573 int 574 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 575 void *buffer, size_t buffer_size) 576 { 577 struct ext4_xattr_ibody_header *header; 578 struct ext4_xattr_entry *entry; 579 struct ext4_inode *raw_inode; 580 struct ext4_iloc iloc; 581 size_t size; 582 void *end; 583 int error; 584 585 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 586 return -ENODATA; 587 error = ext4_get_inode_loc(inode, &iloc); 588 if (error) 589 return error; 590 raw_inode = ext4_raw_inode(&iloc); 591 header = IHDR(inode, raw_inode); 592 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 593 error = xattr_check_inode(inode, header, end); 594 if (error) 595 goto cleanup; 596 entry = IFIRST(header); 597 error = xattr_find_entry(inode, &entry, end, name_index, name, 0); 598 if (error) 599 goto cleanup; 600 size = le32_to_cpu(entry->e_value_size); 601 error = -ERANGE; 602 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 603 goto cleanup; 604 if (buffer) { 605 if (size > buffer_size) 606 goto cleanup; 607 if (entry->e_value_inum) { 608 error = ext4_xattr_inode_get(inode, entry, buffer, 609 size); 610 if (error) 611 goto cleanup; 612 } else { 613 u16 offset = le16_to_cpu(entry->e_value_offs); 614 void *p = (void *)IFIRST(header) + offset; 615 616 if (unlikely(p + size > end)) 617 goto cleanup; 618 memcpy(buffer, p, size); 619 } 620 } 621 error = size; 622 623 cleanup: 624 brelse(iloc.bh); 625 return error; 626 } 627 628 /* 629 * ext4_xattr_get() 630 * 631 * Copy an extended attribute into the buffer 632 * provided, or compute the buffer size required. 633 * Buffer is NULL to compute the size of the buffer required. 634 * 635 * Returns a negative error number on failure, or the number of bytes 636 * used / required on success. 637 */ 638 int 639 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 640 void *buffer, size_t buffer_size) 641 { 642 int error; 643 644 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 645 return -EIO; 646 647 if (strlen(name) > 255) 648 return -ERANGE; 649 650 down_read(&EXT4_I(inode)->xattr_sem); 651 error = ext4_xattr_ibody_get(inode, name_index, name, buffer, 652 buffer_size); 653 if (error == -ENODATA) 654 error = ext4_xattr_block_get(inode, name_index, name, buffer, 655 buffer_size); 656 up_read(&EXT4_I(inode)->xattr_sem); 657 return error; 658 } 659 660 static int 661 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, 662 char *buffer, size_t buffer_size) 663 { 664 size_t rest = buffer_size; 665 666 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 667 const struct xattr_handler *handler = 668 ext4_xattr_handler(entry->e_name_index); 669 670 if (handler && (!handler->list || handler->list(dentry))) { 671 const char *prefix = handler->prefix ?: handler->name; 672 size_t prefix_len = strlen(prefix); 673 size_t size = prefix_len + entry->e_name_len + 1; 674 675 if (buffer) { 676 if (size > rest) 677 return -ERANGE; 678 memcpy(buffer, prefix, prefix_len); 679 buffer += prefix_len; 680 memcpy(buffer, entry->e_name, entry->e_name_len); 681 buffer += entry->e_name_len; 682 *buffer++ = 0; 683 } 684 rest -= size; 685 } 686 } 687 return buffer_size - rest; /* total size */ 688 } 689 690 static int 691 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) 692 { 693 struct inode *inode = d_inode(dentry); 694 struct buffer_head *bh = NULL; 695 int error; 696 697 ea_idebug(inode, "buffer=%p, buffer_size=%ld", 698 buffer, (long)buffer_size); 699 700 if (!EXT4_I(inode)->i_file_acl) 701 return 0; 702 ea_idebug(inode, "reading block %llu", 703 (unsigned long long)EXT4_I(inode)->i_file_acl); 704 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 705 if (IS_ERR(bh)) 706 return PTR_ERR(bh); 707 ea_bdebug(bh, "b_count=%d, refcount=%d", 708 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 709 error = ext4_xattr_check_block(inode, bh); 710 if (error) 711 goto cleanup; 712 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); 713 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, 714 buffer_size); 715 cleanup: 716 brelse(bh); 717 return error; 718 } 719 720 static int 721 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 722 { 723 struct inode *inode = d_inode(dentry); 724 struct ext4_xattr_ibody_header *header; 725 struct ext4_inode *raw_inode; 726 struct ext4_iloc iloc; 727 void *end; 728 int error; 729 730 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 731 return 0; 732 error = ext4_get_inode_loc(inode, &iloc); 733 if (error) 734 return error; 735 raw_inode = ext4_raw_inode(&iloc); 736 header = IHDR(inode, raw_inode); 737 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 738 error = xattr_check_inode(inode, header, end); 739 if (error) 740 goto cleanup; 741 error = ext4_xattr_list_entries(dentry, IFIRST(header), 742 buffer, buffer_size); 743 744 cleanup: 745 brelse(iloc.bh); 746 return error; 747 } 748 749 /* 750 * Inode operation listxattr() 751 * 752 * d_inode(dentry)->i_rwsem: don't care 753 * 754 * Copy a list of attribute names into the buffer 755 * provided, or compute the buffer size required. 756 * Buffer is NULL to compute the size of the buffer required. 757 * 758 * Returns a negative error number on failure, or the number of bytes 759 * used / required on success. 760 */ 761 ssize_t 762 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 763 { 764 int ret, ret2; 765 766 down_read(&EXT4_I(d_inode(dentry))->xattr_sem); 767 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); 768 if (ret < 0) 769 goto errout; 770 if (buffer) { 771 buffer += ret; 772 buffer_size -= ret; 773 } 774 ret = ext4_xattr_block_list(dentry, buffer, buffer_size); 775 if (ret < 0) 776 goto errout; 777 ret += ret2; 778 errout: 779 up_read(&EXT4_I(d_inode(dentry))->xattr_sem); 780 return ret; 781 } 782 783 /* 784 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is 785 * not set, set it. 786 */ 787 static void ext4_xattr_update_super_block(handle_t *handle, 788 struct super_block *sb) 789 { 790 if (ext4_has_feature_xattr(sb)) 791 return; 792 793 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 794 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { 795 ext4_set_feature_xattr(sb); 796 ext4_handle_dirty_super(handle, sb); 797 } 798 } 799 800 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 801 { 802 struct ext4_iloc iloc = { .bh = NULL }; 803 struct buffer_head *bh = NULL; 804 struct ext4_inode *raw_inode; 805 struct ext4_xattr_ibody_header *header; 806 struct ext4_xattr_entry *entry; 807 qsize_t ea_inode_refs = 0; 808 void *end; 809 int ret; 810 811 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); 812 813 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 814 ret = ext4_get_inode_loc(inode, &iloc); 815 if (ret) 816 goto out; 817 raw_inode = ext4_raw_inode(&iloc); 818 header = IHDR(inode, raw_inode); 819 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 820 ret = xattr_check_inode(inode, header, end); 821 if (ret) 822 goto out; 823 824 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); 825 entry = EXT4_XATTR_NEXT(entry)) 826 if (entry->e_value_inum) 827 ea_inode_refs++; 828 } 829 830 if (EXT4_I(inode)->i_file_acl) { 831 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 832 if (IS_ERR(bh)) { 833 ret = PTR_ERR(bh); 834 bh = NULL; 835 goto out; 836 } 837 838 ret = ext4_xattr_check_block(inode, bh); 839 if (ret) 840 goto out; 841 842 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 843 entry = EXT4_XATTR_NEXT(entry)) 844 if (entry->e_value_inum) 845 ea_inode_refs++; 846 } 847 *usage = ea_inode_refs + 1; 848 ret = 0; 849 out: 850 brelse(iloc.bh); 851 brelse(bh); 852 return ret; 853 } 854 855 static inline size_t round_up_cluster(struct inode *inode, size_t length) 856 { 857 struct super_block *sb = inode->i_sb; 858 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits + 859 inode->i_blkbits); 860 size_t mask = ~(cluster_size - 1); 861 862 return (length + cluster_size - 1) & mask; 863 } 864 865 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len) 866 { 867 int err; 868 869 err = dquot_alloc_inode(inode); 870 if (err) 871 return err; 872 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len)); 873 if (err) 874 dquot_free_inode(inode); 875 return err; 876 } 877 878 static void ext4_xattr_inode_free_quota(struct inode *parent, 879 struct inode *ea_inode, 880 size_t len) 881 { 882 if (ea_inode && 883 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) 884 return; 885 dquot_free_space_nodirty(parent, round_up_cluster(parent, len)); 886 dquot_free_inode(parent); 887 } 888 889 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, 890 struct buffer_head *block_bh, size_t value_len, 891 bool is_create) 892 { 893 int credits; 894 int blocks; 895 896 /* 897 * 1) Owner inode update 898 * 2) Ref count update on old xattr block 899 * 3) new xattr block 900 * 4) block bitmap update for new xattr block 901 * 5) group descriptor for new xattr block 902 * 6) block bitmap update for old xattr block 903 * 7) group descriptor for old block 904 * 905 * 6 & 7 can happen if we have two racing threads T_a and T_b 906 * which are each trying to set an xattr on inodes I_a and I_b 907 * which were both initially sharing an xattr block. 908 */ 909 credits = 7; 910 911 /* Quota updates. */ 912 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb); 913 914 /* 915 * In case of inline data, we may push out the data to a block, 916 * so we need to reserve credits for this eventuality 917 */ 918 if (inode && ext4_has_inline_data(inode)) 919 credits += ext4_writepage_trans_blocks(inode) + 1; 920 921 /* We are done if ea_inode feature is not enabled. */ 922 if (!ext4_has_feature_ea_inode(sb)) 923 return credits; 924 925 /* New ea_inode, inode map, block bitmap, group descriptor. */ 926 credits += 4; 927 928 /* Data blocks. */ 929 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 930 931 /* Indirection block or one level of extent tree. */ 932 blocks += 1; 933 934 /* Block bitmap and group descriptor updates for each block. */ 935 credits += blocks * 2; 936 937 /* Blocks themselves. */ 938 credits += blocks; 939 940 if (!is_create) { 941 /* Dereference ea_inode holding old xattr value. 942 * Old ea_inode, inode map, block bitmap, group descriptor. 943 */ 944 credits += 4; 945 946 /* Data blocks for old ea_inode. */ 947 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits; 948 949 /* Indirection block or one level of extent tree for old 950 * ea_inode. 951 */ 952 blocks += 1; 953 954 /* Block bitmap and group descriptor updates for each block. */ 955 credits += blocks * 2; 956 } 957 958 /* We may need to clone the existing xattr block in which case we need 959 * to increment ref counts for existing ea_inodes referenced by it. 960 */ 961 if (block_bh) { 962 struct ext4_xattr_entry *entry = BFIRST(block_bh); 963 964 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) 965 if (entry->e_value_inum) 966 /* Ref count update on ea_inode. */ 967 credits += 1; 968 } 969 return credits; 970 } 971 972 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode, 973 int ref_change) 974 { 975 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode); 976 struct ext4_iloc iloc; 977 s64 ref_count; 978 u32 hash; 979 int ret; 980 981 inode_lock(ea_inode); 982 983 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc); 984 if (ret) 985 goto out; 986 987 ref_count = ext4_xattr_inode_get_ref(ea_inode); 988 ref_count += ref_change; 989 ext4_xattr_inode_set_ref(ea_inode, ref_count); 990 991 if (ref_change > 0) { 992 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld", 993 ea_inode->i_ino, ref_count); 994 995 if (ref_count == 1) { 996 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u", 997 ea_inode->i_ino, ea_inode->i_nlink); 998 999 set_nlink(ea_inode, 1); 1000 ext4_orphan_del(handle, ea_inode); 1001 1002 if (ea_inode_cache) { 1003 hash = ext4_xattr_inode_get_hash(ea_inode); 1004 mb_cache_entry_create(ea_inode_cache, 1005 GFP_NOFS, hash, 1006 ea_inode->i_ino, 1007 true /* reusable */); 1008 } 1009 } 1010 } else { 1011 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld", 1012 ea_inode->i_ino, ref_count); 1013 1014 if (ref_count == 0) { 1015 WARN_ONCE(ea_inode->i_nlink != 1, 1016 "EA inode %lu i_nlink=%u", 1017 ea_inode->i_ino, ea_inode->i_nlink); 1018 1019 clear_nlink(ea_inode); 1020 ext4_orphan_add(handle, ea_inode); 1021 1022 if (ea_inode_cache) { 1023 hash = ext4_xattr_inode_get_hash(ea_inode); 1024 mb_cache_entry_delete(ea_inode_cache, hash, 1025 ea_inode->i_ino); 1026 } 1027 } 1028 } 1029 1030 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc); 1031 if (ret) 1032 ext4_warning_inode(ea_inode, 1033 "ext4_mark_iloc_dirty() failed ret=%d", ret); 1034 out: 1035 inode_unlock(ea_inode); 1036 return ret; 1037 } 1038 1039 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode) 1040 { 1041 return ext4_xattr_inode_update_ref(handle, ea_inode, 1); 1042 } 1043 1044 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode) 1045 { 1046 return ext4_xattr_inode_update_ref(handle, ea_inode, -1); 1047 } 1048 1049 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent, 1050 struct ext4_xattr_entry *first) 1051 { 1052 struct inode *ea_inode; 1053 struct ext4_xattr_entry *entry; 1054 struct ext4_xattr_entry *failed_entry; 1055 unsigned int ea_ino; 1056 int err, saved_err; 1057 1058 for (entry = first; !IS_LAST_ENTRY(entry); 1059 entry = EXT4_XATTR_NEXT(entry)) { 1060 if (!entry->e_value_inum) 1061 continue; 1062 ea_ino = le32_to_cpu(entry->e_value_inum); 1063 err = ext4_xattr_inode_iget(parent, ea_ino, 1064 le32_to_cpu(entry->e_hash), 1065 &ea_inode); 1066 if (err) 1067 goto cleanup; 1068 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1069 if (err) { 1070 ext4_warning_inode(ea_inode, "inc ref error %d", err); 1071 iput(ea_inode); 1072 goto cleanup; 1073 } 1074 iput(ea_inode); 1075 } 1076 return 0; 1077 1078 cleanup: 1079 saved_err = err; 1080 failed_entry = entry; 1081 1082 for (entry = first; entry != failed_entry; 1083 entry = EXT4_XATTR_NEXT(entry)) { 1084 if (!entry->e_value_inum) 1085 continue; 1086 ea_ino = le32_to_cpu(entry->e_value_inum); 1087 err = ext4_xattr_inode_iget(parent, ea_ino, 1088 le32_to_cpu(entry->e_hash), 1089 &ea_inode); 1090 if (err) { 1091 ext4_warning(parent->i_sb, 1092 "cleanup ea_ino %u iget error %d", ea_ino, 1093 err); 1094 continue; 1095 } 1096 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1097 if (err) 1098 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", 1099 err); 1100 iput(ea_inode); 1101 } 1102 return saved_err; 1103 } 1104 1105 static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode, 1106 struct buffer_head *bh, bool block_csum, bool dirty) 1107 { 1108 int error; 1109 1110 if (bh && dirty) { 1111 if (block_csum) 1112 ext4_xattr_block_csum_set(inode, bh); 1113 error = ext4_handle_dirty_metadata(handle, NULL, bh); 1114 if (error) { 1115 ext4_warning(inode->i_sb, "Handle metadata (error %d)", 1116 error); 1117 return error; 1118 } 1119 } 1120 return 0; 1121 } 1122 1123 static void 1124 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent, 1125 struct buffer_head *bh, 1126 struct ext4_xattr_entry *first, bool block_csum, 1127 struct ext4_xattr_inode_array **ea_inode_array, 1128 int extra_credits, bool skip_quota) 1129 { 1130 struct inode *ea_inode; 1131 struct ext4_xattr_entry *entry; 1132 bool dirty = false; 1133 unsigned int ea_ino; 1134 int err; 1135 int credits; 1136 1137 /* One credit for dec ref on ea_inode, one for orphan list addition, */ 1138 credits = 2 + extra_credits; 1139 1140 for (entry = first; !IS_LAST_ENTRY(entry); 1141 entry = EXT4_XATTR_NEXT(entry)) { 1142 if (!entry->e_value_inum) 1143 continue; 1144 ea_ino = le32_to_cpu(entry->e_value_inum); 1145 err = ext4_xattr_inode_iget(parent, ea_ino, 1146 le32_to_cpu(entry->e_hash), 1147 &ea_inode); 1148 if (err) 1149 continue; 1150 1151 err = ext4_expand_inode_array(ea_inode_array, ea_inode); 1152 if (err) { 1153 ext4_warning_inode(ea_inode, 1154 "Expand inode array err=%d", err); 1155 iput(ea_inode); 1156 continue; 1157 } 1158 1159 err = ext4_journal_ensure_credits_fn(handle, credits, credits, 1160 ext4_free_metadata_revoke_credits(parent->i_sb, 1), 1161 ext4_xattr_restart_fn(handle, parent, bh, block_csum, 1162 dirty)); 1163 if (err < 0) { 1164 ext4_warning_inode(ea_inode, "Ensure credits err=%d", 1165 err); 1166 continue; 1167 } 1168 if (err > 0) { 1169 err = ext4_journal_get_write_access(handle, bh); 1170 if (err) { 1171 ext4_warning_inode(ea_inode, 1172 "Re-get write access err=%d", 1173 err); 1174 continue; 1175 } 1176 } 1177 1178 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1179 if (err) { 1180 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d", 1181 err); 1182 continue; 1183 } 1184 1185 if (!skip_quota) 1186 ext4_xattr_inode_free_quota(parent, ea_inode, 1187 le32_to_cpu(entry->e_value_size)); 1188 1189 /* 1190 * Forget about ea_inode within the same transaction that 1191 * decrements the ref count. This avoids duplicate decrements in 1192 * case the rest of the work spills over to subsequent 1193 * transactions. 1194 */ 1195 entry->e_value_inum = 0; 1196 entry->e_value_size = 0; 1197 1198 dirty = true; 1199 } 1200 1201 if (dirty) { 1202 /* 1203 * Note that we are deliberately skipping csum calculation for 1204 * the final update because we do not expect any journal 1205 * restarts until xattr block is freed. 1206 */ 1207 1208 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1209 if (err) 1210 ext4_warning_inode(parent, 1211 "handle dirty metadata err=%d", err); 1212 } 1213 } 1214 1215 /* 1216 * Release the xattr block BH: If the reference count is > 1, decrement it; 1217 * otherwise free the block. 1218 */ 1219 static void 1220 ext4_xattr_release_block(handle_t *handle, struct inode *inode, 1221 struct buffer_head *bh, 1222 struct ext4_xattr_inode_array **ea_inode_array, 1223 int extra_credits) 1224 { 1225 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1226 u32 hash, ref; 1227 int error = 0; 1228 1229 BUFFER_TRACE(bh, "get_write_access"); 1230 error = ext4_journal_get_write_access(handle, bh); 1231 if (error) 1232 goto out; 1233 1234 lock_buffer(bh); 1235 hash = le32_to_cpu(BHDR(bh)->h_hash); 1236 ref = le32_to_cpu(BHDR(bh)->h_refcount); 1237 if (ref == 1) { 1238 ea_bdebug(bh, "refcount now=0; freeing"); 1239 /* 1240 * This must happen under buffer lock for 1241 * ext4_xattr_block_set() to reliably detect freed block 1242 */ 1243 if (ea_block_cache) 1244 mb_cache_entry_delete(ea_block_cache, hash, 1245 bh->b_blocknr); 1246 get_bh(bh); 1247 unlock_buffer(bh); 1248 1249 if (ext4_has_feature_ea_inode(inode->i_sb)) 1250 ext4_xattr_inode_dec_ref_all(handle, inode, bh, 1251 BFIRST(bh), 1252 true /* block_csum */, 1253 ea_inode_array, 1254 extra_credits, 1255 true /* skip_quota */); 1256 ext4_free_blocks(handle, inode, bh, 0, 1, 1257 EXT4_FREE_BLOCKS_METADATA | 1258 EXT4_FREE_BLOCKS_FORGET); 1259 } else { 1260 ref--; 1261 BHDR(bh)->h_refcount = cpu_to_le32(ref); 1262 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) { 1263 struct mb_cache_entry *ce; 1264 1265 if (ea_block_cache) { 1266 ce = mb_cache_entry_get(ea_block_cache, hash, 1267 bh->b_blocknr); 1268 if (ce) { 1269 ce->e_reusable = 1; 1270 mb_cache_entry_put(ea_block_cache, ce); 1271 } 1272 } 1273 } 1274 1275 ext4_xattr_block_csum_set(inode, bh); 1276 /* 1277 * Beware of this ugliness: Releasing of xattr block references 1278 * from different inodes can race and so we have to protect 1279 * from a race where someone else frees the block (and releases 1280 * its journal_head) before we are done dirtying the buffer. In 1281 * nojournal mode this race is harmless and we actually cannot 1282 * call ext4_handle_dirty_metadata() with locked buffer as 1283 * that function can call sync_dirty_buffer() so for that case 1284 * we handle the dirtying after unlocking the buffer. 1285 */ 1286 if (ext4_handle_valid(handle)) 1287 error = ext4_handle_dirty_metadata(handle, inode, bh); 1288 unlock_buffer(bh); 1289 if (!ext4_handle_valid(handle)) 1290 error = ext4_handle_dirty_metadata(handle, inode, bh); 1291 if (IS_SYNC(inode)) 1292 ext4_handle_sync(handle); 1293 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); 1294 ea_bdebug(bh, "refcount now=%d; releasing", 1295 le32_to_cpu(BHDR(bh)->h_refcount)); 1296 } 1297 out: 1298 ext4_std_error(inode->i_sb, error); 1299 return; 1300 } 1301 1302 /* 1303 * Find the available free space for EAs. This also returns the total number of 1304 * bytes used by EA entries. 1305 */ 1306 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, 1307 size_t *min_offs, void *base, int *total) 1308 { 1309 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1310 if (!last->e_value_inum && last->e_value_size) { 1311 size_t offs = le16_to_cpu(last->e_value_offs); 1312 if (offs < *min_offs) 1313 *min_offs = offs; 1314 } 1315 if (total) 1316 *total += EXT4_XATTR_LEN(last->e_name_len); 1317 } 1318 return (*min_offs - ((void *)last - base) - sizeof(__u32)); 1319 } 1320 1321 /* 1322 * Write the value of the EA in an inode. 1323 */ 1324 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode, 1325 const void *buf, int bufsize) 1326 { 1327 struct buffer_head *bh = NULL; 1328 unsigned long block = 0; 1329 int blocksize = ea_inode->i_sb->s_blocksize; 1330 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits; 1331 int csize, wsize = 0; 1332 int ret = 0, ret2 = 0; 1333 int retries = 0; 1334 1335 retry: 1336 while (ret >= 0 && ret < max_blocks) { 1337 struct ext4_map_blocks map; 1338 map.m_lblk = block += ret; 1339 map.m_len = max_blocks -= ret; 1340 1341 ret = ext4_map_blocks(handle, ea_inode, &map, 1342 EXT4_GET_BLOCKS_CREATE); 1343 if (ret <= 0) { 1344 ext4_mark_inode_dirty(handle, ea_inode); 1345 if (ret == -ENOSPC && 1346 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) { 1347 ret = 0; 1348 goto retry; 1349 } 1350 break; 1351 } 1352 } 1353 1354 if (ret < 0) 1355 return ret; 1356 1357 block = 0; 1358 while (wsize < bufsize) { 1359 brelse(bh); 1360 csize = (bufsize - wsize) > blocksize ? blocksize : 1361 bufsize - wsize; 1362 bh = ext4_getblk(handle, ea_inode, block, 0); 1363 if (IS_ERR(bh)) 1364 return PTR_ERR(bh); 1365 if (!bh) { 1366 WARN_ON_ONCE(1); 1367 EXT4_ERROR_INODE(ea_inode, 1368 "ext4_getblk() return bh = NULL"); 1369 return -EFSCORRUPTED; 1370 } 1371 ret = ext4_journal_get_write_access(handle, bh); 1372 if (ret) 1373 goto out; 1374 1375 memcpy(bh->b_data, buf, csize); 1376 set_buffer_uptodate(bh); 1377 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1378 1379 buf += csize; 1380 wsize += csize; 1381 block += 1; 1382 } 1383 1384 inode_lock(ea_inode); 1385 i_size_write(ea_inode, wsize); 1386 ext4_update_i_disksize(ea_inode, wsize); 1387 inode_unlock(ea_inode); 1388 1389 ret2 = ext4_mark_inode_dirty(handle, ea_inode); 1390 if (unlikely(ret2 && !ret)) 1391 ret = ret2; 1392 1393 out: 1394 brelse(bh); 1395 1396 return ret; 1397 } 1398 1399 /* 1400 * Create an inode to store the value of a large EA. 1401 */ 1402 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1403 struct inode *inode, u32 hash) 1404 { 1405 struct inode *ea_inode = NULL; 1406 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1407 int err; 1408 1409 /* 1410 * Let the next inode be the goal, so we try and allocate the EA inode 1411 * in the same group, or nearby one. 1412 */ 1413 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1414 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1415 EXT4_EA_INODE_FL); 1416 if (!IS_ERR(ea_inode)) { 1417 ea_inode->i_op = &ext4_file_inode_operations; 1418 ea_inode->i_fop = &ext4_file_operations; 1419 ext4_set_aops(ea_inode); 1420 ext4_xattr_inode_set_class(ea_inode); 1421 unlock_new_inode(ea_inode); 1422 ext4_xattr_inode_set_ref(ea_inode, 1); 1423 ext4_xattr_inode_set_hash(ea_inode, hash); 1424 err = ext4_mark_inode_dirty(handle, ea_inode); 1425 if (!err) 1426 err = ext4_inode_attach_jinode(ea_inode); 1427 if (err) { 1428 iput(ea_inode); 1429 return ERR_PTR(err); 1430 } 1431 1432 /* 1433 * Xattr inodes are shared therefore quota charging is performed 1434 * at a higher level. 1435 */ 1436 dquot_free_inode(ea_inode); 1437 dquot_drop(ea_inode); 1438 inode_lock(ea_inode); 1439 ea_inode->i_flags |= S_NOQUOTA; 1440 inode_unlock(ea_inode); 1441 } 1442 1443 return ea_inode; 1444 } 1445 1446 static struct inode * 1447 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1448 size_t value_len, u32 hash) 1449 { 1450 struct inode *ea_inode; 1451 struct mb_cache_entry *ce; 1452 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1453 void *ea_data; 1454 1455 if (!ea_inode_cache) 1456 return NULL; 1457 1458 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1459 if (!ce) 1460 return NULL; 1461 1462 ea_data = kvmalloc(value_len, GFP_KERNEL); 1463 if (!ea_data) { 1464 mb_cache_entry_put(ea_inode_cache, ce); 1465 return NULL; 1466 } 1467 1468 while (ce) { 1469 ea_inode = ext4_iget(inode->i_sb, ce->e_value, 1470 EXT4_IGET_NORMAL); 1471 if (!IS_ERR(ea_inode) && 1472 !is_bad_inode(ea_inode) && 1473 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1474 i_size_read(ea_inode) == value_len && 1475 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1476 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1477 value_len) && 1478 !memcmp(value, ea_data, value_len)) { 1479 mb_cache_entry_touch(ea_inode_cache, ce); 1480 mb_cache_entry_put(ea_inode_cache, ce); 1481 kvfree(ea_data); 1482 return ea_inode; 1483 } 1484 1485 if (!IS_ERR(ea_inode)) 1486 iput(ea_inode); 1487 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1488 } 1489 kvfree(ea_data); 1490 return NULL; 1491 } 1492 1493 /* 1494 * Add value of the EA in an inode. 1495 */ 1496 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1497 const void *value, size_t value_len, 1498 struct inode **ret_inode) 1499 { 1500 struct inode *ea_inode; 1501 u32 hash; 1502 int err; 1503 1504 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1505 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1506 if (ea_inode) { 1507 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1508 if (err) { 1509 iput(ea_inode); 1510 return err; 1511 } 1512 1513 *ret_inode = ea_inode; 1514 return 0; 1515 } 1516 1517 /* Create an inode for the EA value */ 1518 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1519 if (IS_ERR(ea_inode)) 1520 return PTR_ERR(ea_inode); 1521 1522 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1523 if (err) { 1524 ext4_xattr_inode_dec_ref(handle, ea_inode); 1525 iput(ea_inode); 1526 return err; 1527 } 1528 1529 if (EA_INODE_CACHE(inode)) 1530 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1531 ea_inode->i_ino, true /* reusable */); 1532 1533 *ret_inode = ea_inode; 1534 return 0; 1535 } 1536 1537 /* 1538 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1539 * feature is enabled. 1540 */ 1541 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1542 1543 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1544 struct ext4_xattr_search *s, 1545 handle_t *handle, struct inode *inode, 1546 bool is_block) 1547 { 1548 struct ext4_xattr_entry *last, *next; 1549 struct ext4_xattr_entry *here = s->here; 1550 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1551 int in_inode = i->in_inode; 1552 struct inode *old_ea_inode = NULL; 1553 struct inode *new_ea_inode = NULL; 1554 size_t old_size, new_size; 1555 int ret; 1556 1557 /* Space used by old and new values. */ 1558 old_size = (!s->not_found && !here->e_value_inum) ? 1559 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1560 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1561 1562 /* 1563 * Optimization for the simple case when old and new values have the 1564 * same padded sizes. Not applicable if external inodes are involved. 1565 */ 1566 if (new_size && new_size == old_size) { 1567 size_t offs = le16_to_cpu(here->e_value_offs); 1568 void *val = s->base + offs; 1569 1570 here->e_value_size = cpu_to_le32(i->value_len); 1571 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1572 memset(val, 0, new_size); 1573 } else { 1574 memcpy(val, i->value, i->value_len); 1575 /* Clear padding bytes. */ 1576 memset(val + i->value_len, 0, new_size - i->value_len); 1577 } 1578 goto update_hash; 1579 } 1580 1581 /* Compute min_offs and last. */ 1582 last = s->first; 1583 for (; !IS_LAST_ENTRY(last); last = next) { 1584 next = EXT4_XATTR_NEXT(last); 1585 if ((void *)next >= s->end) { 1586 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 1587 ret = -EFSCORRUPTED; 1588 goto out; 1589 } 1590 if (!last->e_value_inum && last->e_value_size) { 1591 size_t offs = le16_to_cpu(last->e_value_offs); 1592 if (offs < min_offs) 1593 min_offs = offs; 1594 } 1595 } 1596 1597 /* Check whether we have enough space. */ 1598 if (i->value) { 1599 size_t free; 1600 1601 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1602 if (!s->not_found) 1603 free += EXT4_XATTR_LEN(name_len) + old_size; 1604 1605 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1606 ret = -ENOSPC; 1607 goto out; 1608 } 1609 1610 /* 1611 * If storing the value in an external inode is an option, 1612 * reserve space for xattr entries/names in the external 1613 * attribute block so that a long value does not occupy the 1614 * whole space and prevent futher entries being added. 1615 */ 1616 if (ext4_has_feature_ea_inode(inode->i_sb) && 1617 new_size && is_block && 1618 (min_offs + old_size - new_size) < 1619 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1620 ret = -ENOSPC; 1621 goto out; 1622 } 1623 } 1624 1625 /* 1626 * Getting access to old and new ea inodes is subject to failures. 1627 * Finish that work before doing any modifications to the xattr data. 1628 */ 1629 if (!s->not_found && here->e_value_inum) { 1630 ret = ext4_xattr_inode_iget(inode, 1631 le32_to_cpu(here->e_value_inum), 1632 le32_to_cpu(here->e_hash), 1633 &old_ea_inode); 1634 if (ret) { 1635 old_ea_inode = NULL; 1636 goto out; 1637 } 1638 } 1639 if (i->value && in_inode) { 1640 WARN_ON_ONCE(!i->value_len); 1641 1642 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1643 if (ret) 1644 goto out; 1645 1646 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1647 i->value_len, 1648 &new_ea_inode); 1649 if (ret) { 1650 new_ea_inode = NULL; 1651 ext4_xattr_inode_free_quota(inode, NULL, i->value_len); 1652 goto out; 1653 } 1654 } 1655 1656 if (old_ea_inode) { 1657 /* We are ready to release ref count on the old_ea_inode. */ 1658 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1659 if (ret) { 1660 /* Release newly required ref count on new_ea_inode. */ 1661 if (new_ea_inode) { 1662 int err; 1663 1664 err = ext4_xattr_inode_dec_ref(handle, 1665 new_ea_inode); 1666 if (err) 1667 ext4_warning_inode(new_ea_inode, 1668 "dec ref new_ea_inode err=%d", 1669 err); 1670 ext4_xattr_inode_free_quota(inode, new_ea_inode, 1671 i->value_len); 1672 } 1673 goto out; 1674 } 1675 1676 ext4_xattr_inode_free_quota(inode, old_ea_inode, 1677 le32_to_cpu(here->e_value_size)); 1678 } 1679 1680 /* No failures allowed past this point. */ 1681 1682 if (!s->not_found && here->e_value_size && !here->e_value_inum) { 1683 /* Remove the old value. */ 1684 void *first_val = s->base + min_offs; 1685 size_t offs = le16_to_cpu(here->e_value_offs); 1686 void *val = s->base + offs; 1687 1688 memmove(first_val + old_size, first_val, val - first_val); 1689 memset(first_val, 0, old_size); 1690 min_offs += old_size; 1691 1692 /* Adjust all value offsets. */ 1693 last = s->first; 1694 while (!IS_LAST_ENTRY(last)) { 1695 size_t o = le16_to_cpu(last->e_value_offs); 1696 1697 if (!last->e_value_inum && 1698 last->e_value_size && o < offs) 1699 last->e_value_offs = cpu_to_le16(o + old_size); 1700 last = EXT4_XATTR_NEXT(last); 1701 } 1702 } 1703 1704 if (!i->value) { 1705 /* Remove old name. */ 1706 size_t size = EXT4_XATTR_LEN(name_len); 1707 1708 last = ENTRY((void *)last - size); 1709 memmove(here, (void *)here + size, 1710 (void *)last - (void *)here + sizeof(__u32)); 1711 memset(last, 0, size); 1712 } else if (s->not_found) { 1713 /* Insert new name. */ 1714 size_t size = EXT4_XATTR_LEN(name_len); 1715 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1716 1717 memmove((void *)here + size, here, rest); 1718 memset(here, 0, size); 1719 here->e_name_index = i->name_index; 1720 here->e_name_len = name_len; 1721 memcpy(here->e_name, i->name, name_len); 1722 } else { 1723 /* This is an update, reset value info. */ 1724 here->e_value_inum = 0; 1725 here->e_value_offs = 0; 1726 here->e_value_size = 0; 1727 } 1728 1729 if (i->value) { 1730 /* Insert new value. */ 1731 if (in_inode) { 1732 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1733 } else if (i->value_len) { 1734 void *val = s->base + min_offs - new_size; 1735 1736 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1737 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1738 memset(val, 0, new_size); 1739 } else { 1740 memcpy(val, i->value, i->value_len); 1741 /* Clear padding bytes. */ 1742 memset(val + i->value_len, 0, 1743 new_size - i->value_len); 1744 } 1745 } 1746 here->e_value_size = cpu_to_le32(i->value_len); 1747 } 1748 1749 update_hash: 1750 if (i->value) { 1751 __le32 hash = 0; 1752 1753 /* Entry hash calculation. */ 1754 if (in_inode) { 1755 __le32 crc32c_hash; 1756 1757 /* 1758 * Feed crc32c hash instead of the raw value for entry 1759 * hash calculation. This is to avoid walking 1760 * potentially long value buffer again. 1761 */ 1762 crc32c_hash = cpu_to_le32( 1763 ext4_xattr_inode_get_hash(new_ea_inode)); 1764 hash = ext4_xattr_hash_entry(here->e_name, 1765 here->e_name_len, 1766 &crc32c_hash, 1); 1767 } else if (is_block) { 1768 __le32 *value = s->base + le16_to_cpu( 1769 here->e_value_offs); 1770 1771 hash = ext4_xattr_hash_entry(here->e_name, 1772 here->e_name_len, value, 1773 new_size >> 2); 1774 } 1775 here->e_hash = hash; 1776 } 1777 1778 if (is_block) 1779 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1780 1781 ret = 0; 1782 out: 1783 iput(old_ea_inode); 1784 iput(new_ea_inode); 1785 return ret; 1786 } 1787 1788 struct ext4_xattr_block_find { 1789 struct ext4_xattr_search s; 1790 struct buffer_head *bh; 1791 }; 1792 1793 static int 1794 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1795 struct ext4_xattr_block_find *bs) 1796 { 1797 struct super_block *sb = inode->i_sb; 1798 int error; 1799 1800 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1801 i->name_index, i->name, i->value, (long)i->value_len); 1802 1803 if (EXT4_I(inode)->i_file_acl) { 1804 /* The inode already has an extended attribute block. */ 1805 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 1806 if (IS_ERR(bs->bh)) { 1807 error = PTR_ERR(bs->bh); 1808 bs->bh = NULL; 1809 return error; 1810 } 1811 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1812 atomic_read(&(bs->bh->b_count)), 1813 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1814 error = ext4_xattr_check_block(inode, bs->bh); 1815 if (error) 1816 return error; 1817 /* Find the named attribute. */ 1818 bs->s.base = BHDR(bs->bh); 1819 bs->s.first = BFIRST(bs->bh); 1820 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1821 bs->s.here = bs->s.first; 1822 error = xattr_find_entry(inode, &bs->s.here, bs->s.end, 1823 i->name_index, i->name, 1); 1824 if (error && error != -ENODATA) 1825 return error; 1826 bs->s.not_found = error; 1827 } 1828 return 0; 1829 } 1830 1831 static int 1832 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1833 struct ext4_xattr_info *i, 1834 struct ext4_xattr_block_find *bs) 1835 { 1836 struct super_block *sb = inode->i_sb; 1837 struct buffer_head *new_bh = NULL; 1838 struct ext4_xattr_search s_copy = bs->s; 1839 struct ext4_xattr_search *s = &s_copy; 1840 struct mb_cache_entry *ce = NULL; 1841 int error = 0; 1842 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1843 struct inode *ea_inode = NULL, *tmp_inode; 1844 size_t old_ea_inode_quota = 0; 1845 unsigned int ea_ino; 1846 1847 1848 #define header(x) ((struct ext4_xattr_header *)(x)) 1849 1850 if (s->base) { 1851 BUFFER_TRACE(bs->bh, "get_write_access"); 1852 error = ext4_journal_get_write_access(handle, bs->bh); 1853 if (error) 1854 goto cleanup; 1855 lock_buffer(bs->bh); 1856 1857 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1858 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1859 1860 /* 1861 * This must happen under buffer lock for 1862 * ext4_xattr_block_set() to reliably detect modified 1863 * block 1864 */ 1865 if (ea_block_cache) 1866 mb_cache_entry_delete(ea_block_cache, hash, 1867 bs->bh->b_blocknr); 1868 ea_bdebug(bs->bh, "modifying in-place"); 1869 error = ext4_xattr_set_entry(i, s, handle, inode, 1870 true /* is_block */); 1871 ext4_xattr_block_csum_set(inode, bs->bh); 1872 unlock_buffer(bs->bh); 1873 if (error == -EFSCORRUPTED) 1874 goto bad_block; 1875 if (!error) 1876 error = ext4_handle_dirty_metadata(handle, 1877 inode, 1878 bs->bh); 1879 if (error) 1880 goto cleanup; 1881 goto inserted; 1882 } else { 1883 int offset = (char *)s->here - bs->bh->b_data; 1884 1885 unlock_buffer(bs->bh); 1886 ea_bdebug(bs->bh, "cloning"); 1887 s->base = kmalloc(bs->bh->b_size, GFP_NOFS); 1888 error = -ENOMEM; 1889 if (s->base == NULL) 1890 goto cleanup; 1891 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); 1892 s->first = ENTRY(header(s->base)+1); 1893 header(s->base)->h_refcount = cpu_to_le32(1); 1894 s->here = ENTRY(s->base + offset); 1895 s->end = s->base + bs->bh->b_size; 1896 1897 /* 1898 * If existing entry points to an xattr inode, we need 1899 * to prevent ext4_xattr_set_entry() from decrementing 1900 * ref count on it because the reference belongs to the 1901 * original block. In this case, make the entry look 1902 * like it has an empty value. 1903 */ 1904 if (!s->not_found && s->here->e_value_inum) { 1905 ea_ino = le32_to_cpu(s->here->e_value_inum); 1906 error = ext4_xattr_inode_iget(inode, ea_ino, 1907 le32_to_cpu(s->here->e_hash), 1908 &tmp_inode); 1909 if (error) 1910 goto cleanup; 1911 1912 if (!ext4_test_inode_state(tmp_inode, 1913 EXT4_STATE_LUSTRE_EA_INODE)) { 1914 /* 1915 * Defer quota free call for previous 1916 * inode until success is guaranteed. 1917 */ 1918 old_ea_inode_quota = le32_to_cpu( 1919 s->here->e_value_size); 1920 } 1921 iput(tmp_inode); 1922 1923 s->here->e_value_inum = 0; 1924 s->here->e_value_size = 0; 1925 } 1926 } 1927 } else { 1928 /* Allocate a buffer where we construct the new block. */ 1929 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1930 /* assert(header == s->base) */ 1931 error = -ENOMEM; 1932 if (s->base == NULL) 1933 goto cleanup; 1934 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1935 header(s->base)->h_blocks = cpu_to_le32(1); 1936 header(s->base)->h_refcount = cpu_to_le32(1); 1937 s->first = ENTRY(header(s->base)+1); 1938 s->here = ENTRY(header(s->base)+1); 1939 s->end = s->base + sb->s_blocksize; 1940 } 1941 1942 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1943 if (error == -EFSCORRUPTED) 1944 goto bad_block; 1945 if (error) 1946 goto cleanup; 1947 1948 if (i->value && s->here->e_value_inum) { 1949 /* 1950 * A ref count on ea_inode has been taken as part of the call to 1951 * ext4_xattr_set_entry() above. We would like to drop this 1952 * extra ref but we have to wait until the xattr block is 1953 * initialized and has its own ref count on the ea_inode. 1954 */ 1955 ea_ino = le32_to_cpu(s->here->e_value_inum); 1956 error = ext4_xattr_inode_iget(inode, ea_ino, 1957 le32_to_cpu(s->here->e_hash), 1958 &ea_inode); 1959 if (error) { 1960 ea_inode = NULL; 1961 goto cleanup; 1962 } 1963 } 1964 1965 inserted: 1966 if (!IS_LAST_ENTRY(s->first)) { 1967 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 1968 &ce); 1969 if (new_bh) { 1970 /* We found an identical block in the cache. */ 1971 if (new_bh == bs->bh) 1972 ea_bdebug(new_bh, "keeping"); 1973 else { 1974 u32 ref; 1975 1976 WARN_ON_ONCE(dquot_initialize_needed(inode)); 1977 1978 /* The old block is released after updating 1979 the inode. */ 1980 error = dquot_alloc_block(inode, 1981 EXT4_C2B(EXT4_SB(sb), 1)); 1982 if (error) 1983 goto cleanup; 1984 BUFFER_TRACE(new_bh, "get_write_access"); 1985 error = ext4_journal_get_write_access(handle, 1986 new_bh); 1987 if (error) 1988 goto cleanup_dquot; 1989 lock_buffer(new_bh); 1990 /* 1991 * We have to be careful about races with 1992 * freeing, rehashing or adding references to 1993 * xattr block. Once we hold buffer lock xattr 1994 * block's state is stable so we can check 1995 * whether the block got freed / rehashed or 1996 * not. Since we unhash mbcache entry under 1997 * buffer lock when freeing / rehashing xattr 1998 * block, checking whether entry is still 1999 * hashed is reliable. Same rules hold for 2000 * e_reusable handling. 2001 */ 2002 if (hlist_bl_unhashed(&ce->e_hash_list) || 2003 !ce->e_reusable) { 2004 /* 2005 * Undo everything and check mbcache 2006 * again. 2007 */ 2008 unlock_buffer(new_bh); 2009 dquot_free_block(inode, 2010 EXT4_C2B(EXT4_SB(sb), 2011 1)); 2012 brelse(new_bh); 2013 mb_cache_entry_put(ea_block_cache, ce); 2014 ce = NULL; 2015 new_bh = NULL; 2016 goto inserted; 2017 } 2018 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 2019 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 2020 if (ref >= EXT4_XATTR_REFCOUNT_MAX) 2021 ce->e_reusable = 0; 2022 ea_bdebug(new_bh, "reusing; refcount now=%d", 2023 ref); 2024 ext4_xattr_block_csum_set(inode, new_bh); 2025 unlock_buffer(new_bh); 2026 error = ext4_handle_dirty_metadata(handle, 2027 inode, 2028 new_bh); 2029 if (error) 2030 goto cleanup_dquot; 2031 } 2032 mb_cache_entry_touch(ea_block_cache, ce); 2033 mb_cache_entry_put(ea_block_cache, ce); 2034 ce = NULL; 2035 } else if (bs->bh && s->base == bs->bh->b_data) { 2036 /* We were modifying this block in-place. */ 2037 ea_bdebug(bs->bh, "keeping this block"); 2038 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 2039 new_bh = bs->bh; 2040 get_bh(new_bh); 2041 } else { 2042 /* We need to allocate a new block */ 2043 ext4_fsblk_t goal, block; 2044 2045 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2046 2047 goal = ext4_group_first_block_no(sb, 2048 EXT4_I(inode)->i_block_group); 2049 2050 /* non-extent files can't have physical blocks past 2^32 */ 2051 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2052 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; 2053 2054 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2055 NULL, &error); 2056 if (error) 2057 goto cleanup; 2058 2059 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2060 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); 2061 2062 ea_idebug(inode, "creating block %llu", 2063 (unsigned long long)block); 2064 2065 new_bh = sb_getblk(sb, block); 2066 if (unlikely(!new_bh)) { 2067 error = -ENOMEM; 2068 getblk_failed: 2069 ext4_free_blocks(handle, inode, NULL, block, 1, 2070 EXT4_FREE_BLOCKS_METADATA); 2071 goto cleanup; 2072 } 2073 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2074 ENTRY(header(s->base)+1)); 2075 if (error) 2076 goto getblk_failed; 2077 if (ea_inode) { 2078 /* Drop the extra ref on ea_inode. */ 2079 error = ext4_xattr_inode_dec_ref(handle, 2080 ea_inode); 2081 if (error) 2082 ext4_warning_inode(ea_inode, 2083 "dec ref error=%d", 2084 error); 2085 iput(ea_inode); 2086 ea_inode = NULL; 2087 } 2088 2089 lock_buffer(new_bh); 2090 error = ext4_journal_get_create_access(handle, new_bh); 2091 if (error) { 2092 unlock_buffer(new_bh); 2093 error = -EIO; 2094 goto getblk_failed; 2095 } 2096 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2097 ext4_xattr_block_csum_set(inode, new_bh); 2098 set_buffer_uptodate(new_bh); 2099 unlock_buffer(new_bh); 2100 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2101 error = ext4_handle_dirty_metadata(handle, inode, 2102 new_bh); 2103 if (error) 2104 goto cleanup; 2105 } 2106 } 2107 2108 if (old_ea_inode_quota) 2109 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota); 2110 2111 /* Update the inode. */ 2112 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2113 2114 /* Drop the previous xattr block. */ 2115 if (bs->bh && bs->bh != new_bh) { 2116 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2117 2118 ext4_xattr_release_block(handle, inode, bs->bh, 2119 &ea_inode_array, 2120 0 /* extra_credits */); 2121 ext4_xattr_inode_array_free(ea_inode_array); 2122 } 2123 error = 0; 2124 2125 cleanup: 2126 if (ea_inode) { 2127 int error2; 2128 2129 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2130 if (error2) 2131 ext4_warning_inode(ea_inode, "dec ref error=%d", 2132 error2); 2133 2134 /* If there was an error, revert the quota charge. */ 2135 if (error) 2136 ext4_xattr_inode_free_quota(inode, ea_inode, 2137 i_size_read(ea_inode)); 2138 iput(ea_inode); 2139 } 2140 if (ce) 2141 mb_cache_entry_put(ea_block_cache, ce); 2142 brelse(new_bh); 2143 if (!(bs->bh && s->base == bs->bh->b_data)) 2144 kfree(s->base); 2145 2146 return error; 2147 2148 cleanup_dquot: 2149 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2150 goto cleanup; 2151 2152 bad_block: 2153 EXT4_ERROR_INODE(inode, "bad block %llu", 2154 EXT4_I(inode)->i_file_acl); 2155 goto cleanup; 2156 2157 #undef header 2158 } 2159 2160 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2161 struct ext4_xattr_ibody_find *is) 2162 { 2163 struct ext4_xattr_ibody_header *header; 2164 struct ext4_inode *raw_inode; 2165 int error; 2166 2167 if (EXT4_I(inode)->i_extra_isize == 0) 2168 return 0; 2169 raw_inode = ext4_raw_inode(&is->iloc); 2170 header = IHDR(inode, raw_inode); 2171 is->s.base = is->s.first = IFIRST(header); 2172 is->s.here = is->s.first; 2173 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2174 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2175 error = xattr_check_inode(inode, header, is->s.end); 2176 if (error) 2177 return error; 2178 /* Find the named attribute. */ 2179 error = xattr_find_entry(inode, &is->s.here, is->s.end, 2180 i->name_index, i->name, 0); 2181 if (error && error != -ENODATA) 2182 return error; 2183 is->s.not_found = error; 2184 } 2185 return 0; 2186 } 2187 2188 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 2189 struct ext4_xattr_info *i, 2190 struct ext4_xattr_ibody_find *is) 2191 { 2192 struct ext4_xattr_ibody_header *header; 2193 struct ext4_xattr_search *s = &is->s; 2194 int error; 2195 2196 if (EXT4_I(inode)->i_extra_isize == 0) 2197 return -ENOSPC; 2198 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2199 if (error) 2200 return error; 2201 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2202 if (!IS_LAST_ENTRY(s->first)) { 2203 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2204 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2205 } else { 2206 header->h_magic = cpu_to_le32(0); 2207 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2208 } 2209 return 0; 2210 } 2211 2212 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2213 struct ext4_xattr_info *i, 2214 struct ext4_xattr_ibody_find *is) 2215 { 2216 struct ext4_xattr_ibody_header *header; 2217 struct ext4_xattr_search *s = &is->s; 2218 int error; 2219 2220 if (EXT4_I(inode)->i_extra_isize == 0) 2221 return -ENOSPC; 2222 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2223 if (error) 2224 return error; 2225 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2226 if (!IS_LAST_ENTRY(s->first)) { 2227 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2228 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2229 } else { 2230 header->h_magic = cpu_to_le32(0); 2231 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2232 } 2233 return 0; 2234 } 2235 2236 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2237 struct ext4_xattr_info *i) 2238 { 2239 void *value; 2240 2241 /* When e_value_inum is set the value is stored externally. */ 2242 if (s->here->e_value_inum) 2243 return 0; 2244 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2245 return 0; 2246 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2247 return !memcmp(value, i->value, i->value_len); 2248 } 2249 2250 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2251 { 2252 struct buffer_head *bh; 2253 int error; 2254 2255 if (!EXT4_I(inode)->i_file_acl) 2256 return NULL; 2257 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2258 if (IS_ERR(bh)) 2259 return bh; 2260 error = ext4_xattr_check_block(inode, bh); 2261 if (error) { 2262 brelse(bh); 2263 return ERR_PTR(error); 2264 } 2265 return bh; 2266 } 2267 2268 /* 2269 * ext4_xattr_set_handle() 2270 * 2271 * Create, replace or remove an extended attribute for this inode. Value 2272 * is NULL to remove an existing extended attribute, and non-NULL to 2273 * either replace an existing extended attribute, or create a new extended 2274 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2275 * specify that an extended attribute must exist and must not exist 2276 * previous to the call, respectively. 2277 * 2278 * Returns 0, or a negative error number on failure. 2279 */ 2280 int 2281 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2282 const char *name, const void *value, size_t value_len, 2283 int flags) 2284 { 2285 struct ext4_xattr_info i = { 2286 .name_index = name_index, 2287 .name = name, 2288 .value = value, 2289 .value_len = value_len, 2290 .in_inode = 0, 2291 }; 2292 struct ext4_xattr_ibody_find is = { 2293 .s = { .not_found = -ENODATA, }, 2294 }; 2295 struct ext4_xattr_block_find bs = { 2296 .s = { .not_found = -ENODATA, }, 2297 }; 2298 int no_expand; 2299 int error; 2300 2301 if (!name) 2302 return -EINVAL; 2303 if (strlen(name) > 255) 2304 return -ERANGE; 2305 2306 ext4_write_lock_xattr(inode, &no_expand); 2307 2308 /* Check journal credits under write lock. */ 2309 if (ext4_handle_valid(handle)) { 2310 struct buffer_head *bh; 2311 int credits; 2312 2313 bh = ext4_xattr_get_block(inode); 2314 if (IS_ERR(bh)) { 2315 error = PTR_ERR(bh); 2316 goto cleanup; 2317 } 2318 2319 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2320 value_len, 2321 flags & XATTR_CREATE); 2322 brelse(bh); 2323 2324 if (jbd2_handle_buffer_credits(handle) < credits) { 2325 error = -ENOSPC; 2326 goto cleanup; 2327 } 2328 } 2329 2330 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2331 if (error) 2332 goto cleanup; 2333 2334 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2335 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2336 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2337 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2338 } 2339 2340 error = ext4_xattr_ibody_find(inode, &i, &is); 2341 if (error) 2342 goto cleanup; 2343 if (is.s.not_found) 2344 error = ext4_xattr_block_find(inode, &i, &bs); 2345 if (error) 2346 goto cleanup; 2347 if (is.s.not_found && bs.s.not_found) { 2348 error = -ENODATA; 2349 if (flags & XATTR_REPLACE) 2350 goto cleanup; 2351 error = 0; 2352 if (!value) 2353 goto cleanup; 2354 } else { 2355 error = -EEXIST; 2356 if (flags & XATTR_CREATE) 2357 goto cleanup; 2358 } 2359 2360 if (!value) { 2361 if (!is.s.not_found) 2362 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2363 else if (!bs.s.not_found) 2364 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2365 } else { 2366 error = 0; 2367 /* Xattr value did not change? Save us some work and bail out */ 2368 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2369 goto cleanup; 2370 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2371 goto cleanup; 2372 2373 if (ext4_has_feature_ea_inode(inode->i_sb) && 2374 (EXT4_XATTR_SIZE(i.value_len) > 2375 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2376 i.in_inode = 1; 2377 retry_inode: 2378 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2379 if (!error && !bs.s.not_found) { 2380 i.value = NULL; 2381 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2382 } else if (error == -ENOSPC) { 2383 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2384 brelse(bs.bh); 2385 bs.bh = NULL; 2386 error = ext4_xattr_block_find(inode, &i, &bs); 2387 if (error) 2388 goto cleanup; 2389 } 2390 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2391 if (!error && !is.s.not_found) { 2392 i.value = NULL; 2393 error = ext4_xattr_ibody_set(handle, inode, &i, 2394 &is); 2395 } else if (error == -ENOSPC) { 2396 /* 2397 * Xattr does not fit in the block, store at 2398 * external inode if possible. 2399 */ 2400 if (ext4_has_feature_ea_inode(inode->i_sb) && 2401 !i.in_inode) { 2402 i.in_inode = 1; 2403 goto retry_inode; 2404 } 2405 } 2406 } 2407 } 2408 if (!error) { 2409 ext4_xattr_update_super_block(handle, inode->i_sb); 2410 inode->i_ctime = current_time(inode); 2411 if (!value) 2412 no_expand = 0; 2413 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2414 /* 2415 * The bh is consumed by ext4_mark_iloc_dirty, even with 2416 * error != 0. 2417 */ 2418 is.iloc.bh = NULL; 2419 if (IS_SYNC(inode)) 2420 ext4_handle_sync(handle); 2421 } 2422 2423 cleanup: 2424 brelse(is.iloc.bh); 2425 brelse(bs.bh); 2426 ext4_write_unlock_xattr(inode, &no_expand); 2427 return error; 2428 } 2429 2430 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2431 bool is_create, int *credits) 2432 { 2433 struct buffer_head *bh; 2434 int err; 2435 2436 *credits = 0; 2437 2438 if (!EXT4_SB(inode->i_sb)->s_journal) 2439 return 0; 2440 2441 down_read(&EXT4_I(inode)->xattr_sem); 2442 2443 bh = ext4_xattr_get_block(inode); 2444 if (IS_ERR(bh)) { 2445 err = PTR_ERR(bh); 2446 } else { 2447 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2448 value_len, is_create); 2449 brelse(bh); 2450 err = 0; 2451 } 2452 2453 up_read(&EXT4_I(inode)->xattr_sem); 2454 return err; 2455 } 2456 2457 /* 2458 * ext4_xattr_set() 2459 * 2460 * Like ext4_xattr_set_handle, but start from an inode. This extended 2461 * attribute modification is a filesystem transaction by itself. 2462 * 2463 * Returns 0, or a negative error number on failure. 2464 */ 2465 int 2466 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2467 const void *value, size_t value_len, int flags) 2468 { 2469 handle_t *handle; 2470 struct super_block *sb = inode->i_sb; 2471 int error, retries = 0; 2472 int credits; 2473 2474 error = dquot_initialize(inode); 2475 if (error) 2476 return error; 2477 2478 retry: 2479 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2480 &credits); 2481 if (error) 2482 return error; 2483 2484 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2485 if (IS_ERR(handle)) { 2486 error = PTR_ERR(handle); 2487 } else { 2488 int error2; 2489 2490 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2491 value, value_len, flags); 2492 error2 = ext4_journal_stop(handle); 2493 if (error == -ENOSPC && 2494 ext4_should_retry_alloc(sb, &retries)) 2495 goto retry; 2496 if (error == 0) 2497 error = error2; 2498 } 2499 2500 return error; 2501 } 2502 2503 /* 2504 * Shift the EA entries in the inode to create space for the increased 2505 * i_extra_isize. 2506 */ 2507 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2508 int value_offs_shift, void *to, 2509 void *from, size_t n) 2510 { 2511 struct ext4_xattr_entry *last = entry; 2512 int new_offs; 2513 2514 /* We always shift xattr headers further thus offsets get lower */ 2515 BUG_ON(value_offs_shift > 0); 2516 2517 /* Adjust the value offsets of the entries */ 2518 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2519 if (!last->e_value_inum && last->e_value_size) { 2520 new_offs = le16_to_cpu(last->e_value_offs) + 2521 value_offs_shift; 2522 last->e_value_offs = cpu_to_le16(new_offs); 2523 } 2524 } 2525 /* Shift the entries by n bytes */ 2526 memmove(to, from, n); 2527 } 2528 2529 /* 2530 * Move xattr pointed to by 'entry' from inode into external xattr block 2531 */ 2532 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2533 struct ext4_inode *raw_inode, 2534 struct ext4_xattr_entry *entry) 2535 { 2536 struct ext4_xattr_ibody_find *is = NULL; 2537 struct ext4_xattr_block_find *bs = NULL; 2538 char *buffer = NULL, *b_entry_name = NULL; 2539 size_t value_size = le32_to_cpu(entry->e_value_size); 2540 struct ext4_xattr_info i = { 2541 .value = NULL, 2542 .value_len = 0, 2543 .name_index = entry->e_name_index, 2544 .in_inode = !!entry->e_value_inum, 2545 }; 2546 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2547 int error; 2548 2549 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2550 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2551 buffer = kmalloc(value_size, GFP_NOFS); 2552 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2553 if (!is || !bs || !buffer || !b_entry_name) { 2554 error = -ENOMEM; 2555 goto out; 2556 } 2557 2558 is->s.not_found = -ENODATA; 2559 bs->s.not_found = -ENODATA; 2560 is->iloc.bh = NULL; 2561 bs->bh = NULL; 2562 2563 /* Save the entry name and the entry value */ 2564 if (entry->e_value_inum) { 2565 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2566 if (error) 2567 goto out; 2568 } else { 2569 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2570 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2571 } 2572 2573 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2574 b_entry_name[entry->e_name_len] = '\0'; 2575 i.name = b_entry_name; 2576 2577 error = ext4_get_inode_loc(inode, &is->iloc); 2578 if (error) 2579 goto out; 2580 2581 error = ext4_xattr_ibody_find(inode, &i, is); 2582 if (error) 2583 goto out; 2584 2585 /* Remove the chosen entry from the inode */ 2586 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2587 if (error) 2588 goto out; 2589 2590 i.value = buffer; 2591 i.value_len = value_size; 2592 error = ext4_xattr_block_find(inode, &i, bs); 2593 if (error) 2594 goto out; 2595 2596 /* Add entry which was removed from the inode into the block */ 2597 error = ext4_xattr_block_set(handle, inode, &i, bs); 2598 if (error) 2599 goto out; 2600 error = 0; 2601 out: 2602 kfree(b_entry_name); 2603 kfree(buffer); 2604 if (is) 2605 brelse(is->iloc.bh); 2606 if (bs) 2607 brelse(bs->bh); 2608 kfree(is); 2609 kfree(bs); 2610 2611 return error; 2612 } 2613 2614 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2615 struct ext4_inode *raw_inode, 2616 int isize_diff, size_t ifree, 2617 size_t bfree, int *total_ino) 2618 { 2619 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2620 struct ext4_xattr_entry *small_entry; 2621 struct ext4_xattr_entry *entry; 2622 struct ext4_xattr_entry *last; 2623 unsigned int entry_size; /* EA entry size */ 2624 unsigned int total_size; /* EA entry size + value size */ 2625 unsigned int min_total_size; 2626 int error; 2627 2628 while (isize_diff > ifree) { 2629 entry = NULL; 2630 small_entry = NULL; 2631 min_total_size = ~0U; 2632 last = IFIRST(header); 2633 /* Find the entry best suited to be pushed into EA block */ 2634 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2635 /* never move system.data out of the inode */ 2636 if ((last->e_name_len == 4) && 2637 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) && 2638 !memcmp(last->e_name, "data", 4)) 2639 continue; 2640 total_size = EXT4_XATTR_LEN(last->e_name_len); 2641 if (!last->e_value_inum) 2642 total_size += EXT4_XATTR_SIZE( 2643 le32_to_cpu(last->e_value_size)); 2644 if (total_size <= bfree && 2645 total_size < min_total_size) { 2646 if (total_size + ifree < isize_diff) { 2647 small_entry = last; 2648 } else { 2649 entry = last; 2650 min_total_size = total_size; 2651 } 2652 } 2653 } 2654 2655 if (entry == NULL) { 2656 if (small_entry == NULL) 2657 return -ENOSPC; 2658 entry = small_entry; 2659 } 2660 2661 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2662 total_size = entry_size; 2663 if (!entry->e_value_inum) 2664 total_size += EXT4_XATTR_SIZE( 2665 le32_to_cpu(entry->e_value_size)); 2666 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2667 entry); 2668 if (error) 2669 return error; 2670 2671 *total_ino -= entry_size; 2672 ifree += total_size; 2673 bfree -= total_size; 2674 } 2675 2676 return 0; 2677 } 2678 2679 /* 2680 * Expand an inode by new_extra_isize bytes when EAs are present. 2681 * Returns 0 on success or negative error number on failure. 2682 */ 2683 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2684 struct ext4_inode *raw_inode, handle_t *handle) 2685 { 2686 struct ext4_xattr_ibody_header *header; 2687 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2688 static unsigned int mnt_count; 2689 size_t min_offs; 2690 size_t ifree, bfree; 2691 int total_ino; 2692 void *base, *end; 2693 int error = 0, tried_min_extra_isize = 0; 2694 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2695 int isize_diff; /* How much do we need to grow i_extra_isize */ 2696 2697 retry: 2698 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2699 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2700 return 0; 2701 2702 header = IHDR(inode, raw_inode); 2703 2704 /* 2705 * Check if enough free space is available in the inode to shift the 2706 * entries ahead by new_extra_isize. 2707 */ 2708 2709 base = IFIRST(header); 2710 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2711 min_offs = end - base; 2712 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32); 2713 2714 error = xattr_check_inode(inode, header, end); 2715 if (error) 2716 goto cleanup; 2717 2718 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2719 if (ifree >= isize_diff) 2720 goto shift; 2721 2722 /* 2723 * Enough free space isn't available in the inode, check if 2724 * EA block can hold new_extra_isize bytes. 2725 */ 2726 if (EXT4_I(inode)->i_file_acl) { 2727 struct buffer_head *bh; 2728 2729 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2730 if (IS_ERR(bh)) { 2731 error = PTR_ERR(bh); 2732 goto cleanup; 2733 } 2734 error = ext4_xattr_check_block(inode, bh); 2735 if (error) { 2736 brelse(bh); 2737 goto cleanup; 2738 } 2739 base = BHDR(bh); 2740 end = bh->b_data + bh->b_size; 2741 min_offs = end - base; 2742 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2743 NULL); 2744 brelse(bh); 2745 if (bfree + ifree < isize_diff) { 2746 if (!tried_min_extra_isize && s_min_extra_isize) { 2747 tried_min_extra_isize++; 2748 new_extra_isize = s_min_extra_isize; 2749 goto retry; 2750 } 2751 error = -ENOSPC; 2752 goto cleanup; 2753 } 2754 } else { 2755 bfree = inode->i_sb->s_blocksize; 2756 } 2757 2758 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2759 isize_diff, ifree, bfree, 2760 &total_ino); 2761 if (error) { 2762 if (error == -ENOSPC && !tried_min_extra_isize && 2763 s_min_extra_isize) { 2764 tried_min_extra_isize++; 2765 new_extra_isize = s_min_extra_isize; 2766 goto retry; 2767 } 2768 goto cleanup; 2769 } 2770 shift: 2771 /* Adjust the offsets and shift the remaining entries ahead */ 2772 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2773 - new_extra_isize, (void *)raw_inode + 2774 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2775 (void *)header, total_ino); 2776 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2777 2778 cleanup: 2779 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2780 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2781 inode->i_ino); 2782 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2783 } 2784 return error; 2785 } 2786 2787 #define EIA_INCR 16 /* must be 2^n */ 2788 #define EIA_MASK (EIA_INCR - 1) 2789 2790 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2791 * If @ea_inode_array is new or full it will be grown and the old 2792 * contents copied over. 2793 */ 2794 static int 2795 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2796 struct inode *inode) 2797 { 2798 if (*ea_inode_array == NULL) { 2799 /* 2800 * Start with 15 inodes, so it fits into a power-of-two size. 2801 * If *ea_inode_array is NULL, this is essentially offsetof() 2802 */ 2803 (*ea_inode_array) = 2804 kmalloc(offsetof(struct ext4_xattr_inode_array, 2805 inodes[EIA_MASK]), 2806 GFP_NOFS); 2807 if (*ea_inode_array == NULL) 2808 return -ENOMEM; 2809 (*ea_inode_array)->count = 0; 2810 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2811 /* expand the array once all 15 + n * 16 slots are full */ 2812 struct ext4_xattr_inode_array *new_array = NULL; 2813 int count = (*ea_inode_array)->count; 2814 2815 /* if new_array is NULL, this is essentially offsetof() */ 2816 new_array = kmalloc( 2817 offsetof(struct ext4_xattr_inode_array, 2818 inodes[count + EIA_INCR]), 2819 GFP_NOFS); 2820 if (new_array == NULL) 2821 return -ENOMEM; 2822 memcpy(new_array, *ea_inode_array, 2823 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2824 kfree(*ea_inode_array); 2825 *ea_inode_array = new_array; 2826 } 2827 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2828 return 0; 2829 } 2830 2831 /* 2832 * ext4_xattr_delete_inode() 2833 * 2834 * Free extended attribute resources associated with this inode. Traverse 2835 * all entries and decrement reference on any xattr inodes associated with this 2836 * inode. This is called immediately before an inode is freed. We have exclusive 2837 * access to the inode. If an orphan inode is deleted it will also release its 2838 * references on xattr block and xattr inodes. 2839 */ 2840 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2841 struct ext4_xattr_inode_array **ea_inode_array, 2842 int extra_credits) 2843 { 2844 struct buffer_head *bh = NULL; 2845 struct ext4_xattr_ibody_header *header; 2846 struct ext4_iloc iloc = { .bh = NULL }; 2847 struct ext4_xattr_entry *entry; 2848 struct inode *ea_inode; 2849 int error; 2850 2851 error = ext4_journal_ensure_credits(handle, extra_credits, 2852 ext4_free_metadata_revoke_credits(inode->i_sb, 1)); 2853 if (error < 0) { 2854 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2855 goto cleanup; 2856 } 2857 2858 if (ext4_has_feature_ea_inode(inode->i_sb) && 2859 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2860 2861 error = ext4_get_inode_loc(inode, &iloc); 2862 if (error) { 2863 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2864 goto cleanup; 2865 } 2866 2867 error = ext4_journal_get_write_access(handle, iloc.bh); 2868 if (error) { 2869 EXT4_ERROR_INODE(inode, "write access (error %d)", 2870 error); 2871 goto cleanup; 2872 } 2873 2874 header = IHDR(inode, ext4_raw_inode(&iloc)); 2875 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2876 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2877 IFIRST(header), 2878 false /* block_csum */, 2879 ea_inode_array, 2880 extra_credits, 2881 false /* skip_quota */); 2882 } 2883 2884 if (EXT4_I(inode)->i_file_acl) { 2885 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2886 if (IS_ERR(bh)) { 2887 error = PTR_ERR(bh); 2888 if (error == -EIO) { 2889 EXT4_ERROR_INODE_ERR(inode, EIO, 2890 "block %llu read error", 2891 EXT4_I(inode)->i_file_acl); 2892 } 2893 bh = NULL; 2894 goto cleanup; 2895 } 2896 error = ext4_xattr_check_block(inode, bh); 2897 if (error) 2898 goto cleanup; 2899 2900 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2901 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2902 entry = EXT4_XATTR_NEXT(entry)) { 2903 if (!entry->e_value_inum) 2904 continue; 2905 error = ext4_xattr_inode_iget(inode, 2906 le32_to_cpu(entry->e_value_inum), 2907 le32_to_cpu(entry->e_hash), 2908 &ea_inode); 2909 if (error) 2910 continue; 2911 ext4_xattr_inode_free_quota(inode, ea_inode, 2912 le32_to_cpu(entry->e_value_size)); 2913 iput(ea_inode); 2914 } 2915 2916 } 2917 2918 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2919 extra_credits); 2920 /* 2921 * Update i_file_acl value in the same transaction that releases 2922 * block. 2923 */ 2924 EXT4_I(inode)->i_file_acl = 0; 2925 error = ext4_mark_inode_dirty(handle, inode); 2926 if (error) { 2927 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2928 error); 2929 goto cleanup; 2930 } 2931 } 2932 error = 0; 2933 cleanup: 2934 brelse(iloc.bh); 2935 brelse(bh); 2936 return error; 2937 } 2938 2939 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2940 { 2941 int idx; 2942 2943 if (ea_inode_array == NULL) 2944 return; 2945 2946 for (idx = 0; idx < ea_inode_array->count; ++idx) 2947 iput(ea_inode_array->inodes[idx]); 2948 kfree(ea_inode_array); 2949 } 2950 2951 /* 2952 * ext4_xattr_block_cache_insert() 2953 * 2954 * Create a new entry in the extended attribute block cache, and insert 2955 * it unless such an entry is already in the cache. 2956 * 2957 * Returns 0, or a negative error number on failure. 2958 */ 2959 static void 2960 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2961 struct buffer_head *bh) 2962 { 2963 struct ext4_xattr_header *header = BHDR(bh); 2964 __u32 hash = le32_to_cpu(header->h_hash); 2965 int reusable = le32_to_cpu(header->h_refcount) < 2966 EXT4_XATTR_REFCOUNT_MAX; 2967 int error; 2968 2969 if (!ea_block_cache) 2970 return; 2971 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2972 bh->b_blocknr, reusable); 2973 if (error) { 2974 if (error == -EBUSY) 2975 ea_bdebug(bh, "already in cache"); 2976 } else 2977 ea_bdebug(bh, "inserting [%x]", (int)hash); 2978 } 2979 2980 /* 2981 * ext4_xattr_cmp() 2982 * 2983 * Compare two extended attribute blocks for equality. 2984 * 2985 * Returns 0 if the blocks are equal, 1 if they differ, and 2986 * a negative error number on errors. 2987 */ 2988 static int 2989 ext4_xattr_cmp(struct ext4_xattr_header *header1, 2990 struct ext4_xattr_header *header2) 2991 { 2992 struct ext4_xattr_entry *entry1, *entry2; 2993 2994 entry1 = ENTRY(header1+1); 2995 entry2 = ENTRY(header2+1); 2996 while (!IS_LAST_ENTRY(entry1)) { 2997 if (IS_LAST_ENTRY(entry2)) 2998 return 1; 2999 if (entry1->e_hash != entry2->e_hash || 3000 entry1->e_name_index != entry2->e_name_index || 3001 entry1->e_name_len != entry2->e_name_len || 3002 entry1->e_value_size != entry2->e_value_size || 3003 entry1->e_value_inum != entry2->e_value_inum || 3004 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 3005 return 1; 3006 if (!entry1->e_value_inum && 3007 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 3008 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 3009 le32_to_cpu(entry1->e_value_size))) 3010 return 1; 3011 3012 entry1 = EXT4_XATTR_NEXT(entry1); 3013 entry2 = EXT4_XATTR_NEXT(entry2); 3014 } 3015 if (!IS_LAST_ENTRY(entry2)) 3016 return 1; 3017 return 0; 3018 } 3019 3020 /* 3021 * ext4_xattr_block_cache_find() 3022 * 3023 * Find an identical extended attribute block. 3024 * 3025 * Returns a pointer to the block found, or NULL if such a block was 3026 * not found or an error occurred. 3027 */ 3028 static struct buffer_head * 3029 ext4_xattr_block_cache_find(struct inode *inode, 3030 struct ext4_xattr_header *header, 3031 struct mb_cache_entry **pce) 3032 { 3033 __u32 hash = le32_to_cpu(header->h_hash); 3034 struct mb_cache_entry *ce; 3035 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 3036 3037 if (!ea_block_cache) 3038 return NULL; 3039 if (!header->h_hash) 3040 return NULL; /* never share */ 3041 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 3042 ce = mb_cache_entry_find_first(ea_block_cache, hash); 3043 while (ce) { 3044 struct buffer_head *bh; 3045 3046 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO); 3047 if (IS_ERR(bh)) { 3048 if (PTR_ERR(bh) == -ENOMEM) 3049 return NULL; 3050 bh = NULL; 3051 EXT4_ERROR_INODE(inode, "block %lu read error", 3052 (unsigned long)ce->e_value); 3053 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 3054 *pce = ce; 3055 return bh; 3056 } 3057 brelse(bh); 3058 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3059 } 3060 return NULL; 3061 } 3062 3063 #define NAME_HASH_SHIFT 5 3064 #define VALUE_HASH_SHIFT 16 3065 3066 /* 3067 * ext4_xattr_hash_entry() 3068 * 3069 * Compute the hash of an extended attribute. 3070 */ 3071 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3072 size_t value_count) 3073 { 3074 __u32 hash = 0; 3075 3076 while (name_len--) { 3077 hash = (hash << NAME_HASH_SHIFT) ^ 3078 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3079 *name++; 3080 } 3081 while (value_count--) { 3082 hash = (hash << VALUE_HASH_SHIFT) ^ 3083 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3084 le32_to_cpu(*value++); 3085 } 3086 return cpu_to_le32(hash); 3087 } 3088 3089 #undef NAME_HASH_SHIFT 3090 #undef VALUE_HASH_SHIFT 3091 3092 #define BLOCK_HASH_SHIFT 16 3093 3094 /* 3095 * ext4_xattr_rehash() 3096 * 3097 * Re-compute the extended attribute hash value after an entry has changed. 3098 */ 3099 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3100 { 3101 struct ext4_xattr_entry *here; 3102 __u32 hash = 0; 3103 3104 here = ENTRY(header+1); 3105 while (!IS_LAST_ENTRY(here)) { 3106 if (!here->e_hash) { 3107 /* Block is not shared if an entry's hash value == 0 */ 3108 hash = 0; 3109 break; 3110 } 3111 hash = (hash << BLOCK_HASH_SHIFT) ^ 3112 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3113 le32_to_cpu(here->e_hash); 3114 here = EXT4_XATTR_NEXT(here); 3115 } 3116 header->h_hash = cpu_to_le32(hash); 3117 } 3118 3119 #undef BLOCK_HASH_SHIFT 3120 3121 #define HASH_BUCKET_BITS 10 3122 3123 struct mb_cache * 3124 ext4_xattr_create_cache(void) 3125 { 3126 return mb_cache_create(HASH_BUCKET_BITS); 3127 } 3128 3129 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3130 { 3131 if (cache) 3132 mb_cache_destroy(cache); 3133 } 3134 3135