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 if (bh != NULL) 1360 brelse(bh); 1361 csize = (bufsize - wsize) > blocksize ? blocksize : 1362 bufsize - wsize; 1363 bh = ext4_getblk(handle, ea_inode, block, 0); 1364 if (IS_ERR(bh)) 1365 return PTR_ERR(bh); 1366 if (!bh) { 1367 WARN_ON_ONCE(1); 1368 EXT4_ERROR_INODE(ea_inode, 1369 "ext4_getblk() return bh = NULL"); 1370 return -EFSCORRUPTED; 1371 } 1372 ret = ext4_journal_get_write_access(handle, bh); 1373 if (ret) 1374 goto out; 1375 1376 memcpy(bh->b_data, buf, csize); 1377 set_buffer_uptodate(bh); 1378 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1379 1380 buf += csize; 1381 wsize += csize; 1382 block += 1; 1383 } 1384 1385 inode_lock(ea_inode); 1386 i_size_write(ea_inode, wsize); 1387 ext4_update_i_disksize(ea_inode, wsize); 1388 inode_unlock(ea_inode); 1389 1390 ret2 = ext4_mark_inode_dirty(handle, ea_inode); 1391 if (unlikely(ret2 && !ret)) 1392 ret = ret2; 1393 1394 out: 1395 brelse(bh); 1396 1397 return ret; 1398 } 1399 1400 /* 1401 * Create an inode to store the value of a large EA. 1402 */ 1403 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1404 struct inode *inode, u32 hash) 1405 { 1406 struct inode *ea_inode = NULL; 1407 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1408 int err; 1409 1410 /* 1411 * Let the next inode be the goal, so we try and allocate the EA inode 1412 * in the same group, or nearby one. 1413 */ 1414 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1415 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1416 EXT4_EA_INODE_FL); 1417 if (!IS_ERR(ea_inode)) { 1418 ea_inode->i_op = &ext4_file_inode_operations; 1419 ea_inode->i_fop = &ext4_file_operations; 1420 ext4_set_aops(ea_inode); 1421 ext4_xattr_inode_set_class(ea_inode); 1422 unlock_new_inode(ea_inode); 1423 ext4_xattr_inode_set_ref(ea_inode, 1); 1424 ext4_xattr_inode_set_hash(ea_inode, hash); 1425 err = ext4_mark_inode_dirty(handle, ea_inode); 1426 if (!err) 1427 err = ext4_inode_attach_jinode(ea_inode); 1428 if (err) { 1429 iput(ea_inode); 1430 return ERR_PTR(err); 1431 } 1432 1433 /* 1434 * Xattr inodes are shared therefore quota charging is performed 1435 * at a higher level. 1436 */ 1437 dquot_free_inode(ea_inode); 1438 dquot_drop(ea_inode); 1439 inode_lock(ea_inode); 1440 ea_inode->i_flags |= S_NOQUOTA; 1441 inode_unlock(ea_inode); 1442 } 1443 1444 return ea_inode; 1445 } 1446 1447 static struct inode * 1448 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1449 size_t value_len, u32 hash) 1450 { 1451 struct inode *ea_inode; 1452 struct mb_cache_entry *ce; 1453 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1454 void *ea_data; 1455 1456 if (!ea_inode_cache) 1457 return NULL; 1458 1459 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1460 if (!ce) 1461 return NULL; 1462 1463 ea_data = kvmalloc(value_len, GFP_KERNEL); 1464 if (!ea_data) { 1465 mb_cache_entry_put(ea_inode_cache, ce); 1466 return NULL; 1467 } 1468 1469 while (ce) { 1470 ea_inode = ext4_iget(inode->i_sb, ce->e_value, 1471 EXT4_IGET_NORMAL); 1472 if (!IS_ERR(ea_inode) && 1473 !is_bad_inode(ea_inode) && 1474 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1475 i_size_read(ea_inode) == value_len && 1476 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1477 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1478 value_len) && 1479 !memcmp(value, ea_data, value_len)) { 1480 mb_cache_entry_touch(ea_inode_cache, ce); 1481 mb_cache_entry_put(ea_inode_cache, ce); 1482 kvfree(ea_data); 1483 return ea_inode; 1484 } 1485 1486 if (!IS_ERR(ea_inode)) 1487 iput(ea_inode); 1488 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1489 } 1490 kvfree(ea_data); 1491 return NULL; 1492 } 1493 1494 /* 1495 * Add value of the EA in an inode. 1496 */ 1497 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1498 const void *value, size_t value_len, 1499 struct inode **ret_inode) 1500 { 1501 struct inode *ea_inode; 1502 u32 hash; 1503 int err; 1504 1505 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1506 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1507 if (ea_inode) { 1508 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1509 if (err) { 1510 iput(ea_inode); 1511 return err; 1512 } 1513 1514 *ret_inode = ea_inode; 1515 return 0; 1516 } 1517 1518 /* Create an inode for the EA value */ 1519 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1520 if (IS_ERR(ea_inode)) 1521 return PTR_ERR(ea_inode); 1522 1523 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1524 if (err) { 1525 ext4_xattr_inode_dec_ref(handle, ea_inode); 1526 iput(ea_inode); 1527 return err; 1528 } 1529 1530 if (EA_INODE_CACHE(inode)) 1531 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1532 ea_inode->i_ino, true /* reusable */); 1533 1534 *ret_inode = ea_inode; 1535 return 0; 1536 } 1537 1538 /* 1539 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1540 * feature is enabled. 1541 */ 1542 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1543 1544 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1545 struct ext4_xattr_search *s, 1546 handle_t *handle, struct inode *inode, 1547 bool is_block) 1548 { 1549 struct ext4_xattr_entry *last, *next; 1550 struct ext4_xattr_entry *here = s->here; 1551 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1552 int in_inode = i->in_inode; 1553 struct inode *old_ea_inode = NULL; 1554 struct inode *new_ea_inode = NULL; 1555 size_t old_size, new_size; 1556 int ret; 1557 1558 /* Space used by old and new values. */ 1559 old_size = (!s->not_found && !here->e_value_inum) ? 1560 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1561 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1562 1563 /* 1564 * Optimization for the simple case when old and new values have the 1565 * same padded sizes. Not applicable if external inodes are involved. 1566 */ 1567 if (new_size && new_size == old_size) { 1568 size_t offs = le16_to_cpu(here->e_value_offs); 1569 void *val = s->base + offs; 1570 1571 here->e_value_size = cpu_to_le32(i->value_len); 1572 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1573 memset(val, 0, new_size); 1574 } else { 1575 memcpy(val, i->value, i->value_len); 1576 /* Clear padding bytes. */ 1577 memset(val + i->value_len, 0, new_size - i->value_len); 1578 } 1579 goto update_hash; 1580 } 1581 1582 /* Compute min_offs and last. */ 1583 last = s->first; 1584 for (; !IS_LAST_ENTRY(last); last = next) { 1585 next = EXT4_XATTR_NEXT(last); 1586 if ((void *)next >= s->end) { 1587 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 1588 ret = -EFSCORRUPTED; 1589 goto out; 1590 } 1591 if (!last->e_value_inum && last->e_value_size) { 1592 size_t offs = le16_to_cpu(last->e_value_offs); 1593 if (offs < min_offs) 1594 min_offs = offs; 1595 } 1596 } 1597 1598 /* Check whether we have enough space. */ 1599 if (i->value) { 1600 size_t free; 1601 1602 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1603 if (!s->not_found) 1604 free += EXT4_XATTR_LEN(name_len) + old_size; 1605 1606 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1607 ret = -ENOSPC; 1608 goto out; 1609 } 1610 1611 /* 1612 * If storing the value in an external inode is an option, 1613 * reserve space for xattr entries/names in the external 1614 * attribute block so that a long value does not occupy the 1615 * whole space and prevent futher entries being added. 1616 */ 1617 if (ext4_has_feature_ea_inode(inode->i_sb) && 1618 new_size && is_block && 1619 (min_offs + old_size - new_size) < 1620 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1621 ret = -ENOSPC; 1622 goto out; 1623 } 1624 } 1625 1626 /* 1627 * Getting access to old and new ea inodes is subject to failures. 1628 * Finish that work before doing any modifications to the xattr data. 1629 */ 1630 if (!s->not_found && here->e_value_inum) { 1631 ret = ext4_xattr_inode_iget(inode, 1632 le32_to_cpu(here->e_value_inum), 1633 le32_to_cpu(here->e_hash), 1634 &old_ea_inode); 1635 if (ret) { 1636 old_ea_inode = NULL; 1637 goto out; 1638 } 1639 } 1640 if (i->value && in_inode) { 1641 WARN_ON_ONCE(!i->value_len); 1642 1643 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1644 if (ret) 1645 goto out; 1646 1647 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1648 i->value_len, 1649 &new_ea_inode); 1650 if (ret) { 1651 new_ea_inode = NULL; 1652 ext4_xattr_inode_free_quota(inode, NULL, i->value_len); 1653 goto out; 1654 } 1655 } 1656 1657 if (old_ea_inode) { 1658 /* We are ready to release ref count on the old_ea_inode. */ 1659 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1660 if (ret) { 1661 /* Release newly required ref count on new_ea_inode. */ 1662 if (new_ea_inode) { 1663 int err; 1664 1665 err = ext4_xattr_inode_dec_ref(handle, 1666 new_ea_inode); 1667 if (err) 1668 ext4_warning_inode(new_ea_inode, 1669 "dec ref new_ea_inode err=%d", 1670 err); 1671 ext4_xattr_inode_free_quota(inode, new_ea_inode, 1672 i->value_len); 1673 } 1674 goto out; 1675 } 1676 1677 ext4_xattr_inode_free_quota(inode, old_ea_inode, 1678 le32_to_cpu(here->e_value_size)); 1679 } 1680 1681 /* No failures allowed past this point. */ 1682 1683 if (!s->not_found && here->e_value_size && !here->e_value_inum) { 1684 /* Remove the old value. */ 1685 void *first_val = s->base + min_offs; 1686 size_t offs = le16_to_cpu(here->e_value_offs); 1687 void *val = s->base + offs; 1688 1689 memmove(first_val + old_size, first_val, val - first_val); 1690 memset(first_val, 0, old_size); 1691 min_offs += old_size; 1692 1693 /* Adjust all value offsets. */ 1694 last = s->first; 1695 while (!IS_LAST_ENTRY(last)) { 1696 size_t o = le16_to_cpu(last->e_value_offs); 1697 1698 if (!last->e_value_inum && 1699 last->e_value_size && o < offs) 1700 last->e_value_offs = cpu_to_le16(o + old_size); 1701 last = EXT4_XATTR_NEXT(last); 1702 } 1703 } 1704 1705 if (!i->value) { 1706 /* Remove old name. */ 1707 size_t size = EXT4_XATTR_LEN(name_len); 1708 1709 last = ENTRY((void *)last - size); 1710 memmove(here, (void *)here + size, 1711 (void *)last - (void *)here + sizeof(__u32)); 1712 memset(last, 0, size); 1713 } else if (s->not_found) { 1714 /* Insert new name. */ 1715 size_t size = EXT4_XATTR_LEN(name_len); 1716 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1717 1718 memmove((void *)here + size, here, rest); 1719 memset(here, 0, size); 1720 here->e_name_index = i->name_index; 1721 here->e_name_len = name_len; 1722 memcpy(here->e_name, i->name, name_len); 1723 } else { 1724 /* This is an update, reset value info. */ 1725 here->e_value_inum = 0; 1726 here->e_value_offs = 0; 1727 here->e_value_size = 0; 1728 } 1729 1730 if (i->value) { 1731 /* Insert new value. */ 1732 if (in_inode) { 1733 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1734 } else if (i->value_len) { 1735 void *val = s->base + min_offs - new_size; 1736 1737 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1738 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1739 memset(val, 0, new_size); 1740 } else { 1741 memcpy(val, i->value, i->value_len); 1742 /* Clear padding bytes. */ 1743 memset(val + i->value_len, 0, 1744 new_size - i->value_len); 1745 } 1746 } 1747 here->e_value_size = cpu_to_le32(i->value_len); 1748 } 1749 1750 update_hash: 1751 if (i->value) { 1752 __le32 hash = 0; 1753 1754 /* Entry hash calculation. */ 1755 if (in_inode) { 1756 __le32 crc32c_hash; 1757 1758 /* 1759 * Feed crc32c hash instead of the raw value for entry 1760 * hash calculation. This is to avoid walking 1761 * potentially long value buffer again. 1762 */ 1763 crc32c_hash = cpu_to_le32( 1764 ext4_xattr_inode_get_hash(new_ea_inode)); 1765 hash = ext4_xattr_hash_entry(here->e_name, 1766 here->e_name_len, 1767 &crc32c_hash, 1); 1768 } else if (is_block) { 1769 __le32 *value = s->base + le16_to_cpu( 1770 here->e_value_offs); 1771 1772 hash = ext4_xattr_hash_entry(here->e_name, 1773 here->e_name_len, value, 1774 new_size >> 2); 1775 } 1776 here->e_hash = hash; 1777 } 1778 1779 if (is_block) 1780 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1781 1782 ret = 0; 1783 out: 1784 iput(old_ea_inode); 1785 iput(new_ea_inode); 1786 return ret; 1787 } 1788 1789 struct ext4_xattr_block_find { 1790 struct ext4_xattr_search s; 1791 struct buffer_head *bh; 1792 }; 1793 1794 static int 1795 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1796 struct ext4_xattr_block_find *bs) 1797 { 1798 struct super_block *sb = inode->i_sb; 1799 int error; 1800 1801 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1802 i->name_index, i->name, i->value, (long)i->value_len); 1803 1804 if (EXT4_I(inode)->i_file_acl) { 1805 /* The inode already has an extended attribute block. */ 1806 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 1807 if (IS_ERR(bs->bh)) { 1808 error = PTR_ERR(bs->bh); 1809 bs->bh = NULL; 1810 return error; 1811 } 1812 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1813 atomic_read(&(bs->bh->b_count)), 1814 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1815 error = ext4_xattr_check_block(inode, bs->bh); 1816 if (error) 1817 return error; 1818 /* Find the named attribute. */ 1819 bs->s.base = BHDR(bs->bh); 1820 bs->s.first = BFIRST(bs->bh); 1821 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1822 bs->s.here = bs->s.first; 1823 error = xattr_find_entry(inode, &bs->s.here, bs->s.end, 1824 i->name_index, i->name, 1); 1825 if (error && error != -ENODATA) 1826 return error; 1827 bs->s.not_found = error; 1828 } 1829 return 0; 1830 } 1831 1832 static int 1833 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1834 struct ext4_xattr_info *i, 1835 struct ext4_xattr_block_find *bs) 1836 { 1837 struct super_block *sb = inode->i_sb; 1838 struct buffer_head *new_bh = NULL; 1839 struct ext4_xattr_search s_copy = bs->s; 1840 struct ext4_xattr_search *s = &s_copy; 1841 struct mb_cache_entry *ce = NULL; 1842 int error = 0; 1843 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1844 struct inode *ea_inode = NULL, *tmp_inode; 1845 size_t old_ea_inode_quota = 0; 1846 unsigned int ea_ino; 1847 1848 1849 #define header(x) ((struct ext4_xattr_header *)(x)) 1850 1851 if (s->base) { 1852 BUFFER_TRACE(bs->bh, "get_write_access"); 1853 error = ext4_journal_get_write_access(handle, bs->bh); 1854 if (error) 1855 goto cleanup; 1856 lock_buffer(bs->bh); 1857 1858 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1859 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1860 1861 /* 1862 * This must happen under buffer lock for 1863 * ext4_xattr_block_set() to reliably detect modified 1864 * block 1865 */ 1866 if (ea_block_cache) 1867 mb_cache_entry_delete(ea_block_cache, hash, 1868 bs->bh->b_blocknr); 1869 ea_bdebug(bs->bh, "modifying in-place"); 1870 error = ext4_xattr_set_entry(i, s, handle, inode, 1871 true /* is_block */); 1872 ext4_xattr_block_csum_set(inode, bs->bh); 1873 unlock_buffer(bs->bh); 1874 if (error == -EFSCORRUPTED) 1875 goto bad_block; 1876 if (!error) 1877 error = ext4_handle_dirty_metadata(handle, 1878 inode, 1879 bs->bh); 1880 if (error) 1881 goto cleanup; 1882 goto inserted; 1883 } else { 1884 int offset = (char *)s->here - bs->bh->b_data; 1885 1886 unlock_buffer(bs->bh); 1887 ea_bdebug(bs->bh, "cloning"); 1888 s->base = kmalloc(bs->bh->b_size, GFP_NOFS); 1889 error = -ENOMEM; 1890 if (s->base == NULL) 1891 goto cleanup; 1892 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); 1893 s->first = ENTRY(header(s->base)+1); 1894 header(s->base)->h_refcount = cpu_to_le32(1); 1895 s->here = ENTRY(s->base + offset); 1896 s->end = s->base + bs->bh->b_size; 1897 1898 /* 1899 * If existing entry points to an xattr inode, we need 1900 * to prevent ext4_xattr_set_entry() from decrementing 1901 * ref count on it because the reference belongs to the 1902 * original block. In this case, make the entry look 1903 * like it has an empty value. 1904 */ 1905 if (!s->not_found && s->here->e_value_inum) { 1906 ea_ino = le32_to_cpu(s->here->e_value_inum); 1907 error = ext4_xattr_inode_iget(inode, ea_ino, 1908 le32_to_cpu(s->here->e_hash), 1909 &tmp_inode); 1910 if (error) 1911 goto cleanup; 1912 1913 if (!ext4_test_inode_state(tmp_inode, 1914 EXT4_STATE_LUSTRE_EA_INODE)) { 1915 /* 1916 * Defer quota free call for previous 1917 * inode until success is guaranteed. 1918 */ 1919 old_ea_inode_quota = le32_to_cpu( 1920 s->here->e_value_size); 1921 } 1922 iput(tmp_inode); 1923 1924 s->here->e_value_inum = 0; 1925 s->here->e_value_size = 0; 1926 } 1927 } 1928 } else { 1929 /* Allocate a buffer where we construct the new block. */ 1930 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1931 /* assert(header == s->base) */ 1932 error = -ENOMEM; 1933 if (s->base == NULL) 1934 goto cleanup; 1935 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1936 header(s->base)->h_blocks = cpu_to_le32(1); 1937 header(s->base)->h_refcount = cpu_to_le32(1); 1938 s->first = ENTRY(header(s->base)+1); 1939 s->here = ENTRY(header(s->base)+1); 1940 s->end = s->base + sb->s_blocksize; 1941 } 1942 1943 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1944 if (error == -EFSCORRUPTED) 1945 goto bad_block; 1946 if (error) 1947 goto cleanup; 1948 1949 if (i->value && s->here->e_value_inum) { 1950 /* 1951 * A ref count on ea_inode has been taken as part of the call to 1952 * ext4_xattr_set_entry() above. We would like to drop this 1953 * extra ref but we have to wait until the xattr block is 1954 * initialized and has its own ref count on the ea_inode. 1955 */ 1956 ea_ino = le32_to_cpu(s->here->e_value_inum); 1957 error = ext4_xattr_inode_iget(inode, ea_ino, 1958 le32_to_cpu(s->here->e_hash), 1959 &ea_inode); 1960 if (error) { 1961 ea_inode = NULL; 1962 goto cleanup; 1963 } 1964 } 1965 1966 inserted: 1967 if (!IS_LAST_ENTRY(s->first)) { 1968 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 1969 &ce); 1970 if (new_bh) { 1971 /* We found an identical block in the cache. */ 1972 if (new_bh == bs->bh) 1973 ea_bdebug(new_bh, "keeping"); 1974 else { 1975 u32 ref; 1976 1977 WARN_ON_ONCE(dquot_initialize_needed(inode)); 1978 1979 /* The old block is released after updating 1980 the inode. */ 1981 error = dquot_alloc_block(inode, 1982 EXT4_C2B(EXT4_SB(sb), 1)); 1983 if (error) 1984 goto cleanup; 1985 BUFFER_TRACE(new_bh, "get_write_access"); 1986 error = ext4_journal_get_write_access(handle, 1987 new_bh); 1988 if (error) 1989 goto cleanup_dquot; 1990 lock_buffer(new_bh); 1991 /* 1992 * We have to be careful about races with 1993 * freeing, rehashing or adding references to 1994 * xattr block. Once we hold buffer lock xattr 1995 * block's state is stable so we can check 1996 * whether the block got freed / rehashed or 1997 * not. Since we unhash mbcache entry under 1998 * buffer lock when freeing / rehashing xattr 1999 * block, checking whether entry is still 2000 * hashed is reliable. Same rules hold for 2001 * e_reusable handling. 2002 */ 2003 if (hlist_bl_unhashed(&ce->e_hash_list) || 2004 !ce->e_reusable) { 2005 /* 2006 * Undo everything and check mbcache 2007 * again. 2008 */ 2009 unlock_buffer(new_bh); 2010 dquot_free_block(inode, 2011 EXT4_C2B(EXT4_SB(sb), 2012 1)); 2013 brelse(new_bh); 2014 mb_cache_entry_put(ea_block_cache, ce); 2015 ce = NULL; 2016 new_bh = NULL; 2017 goto inserted; 2018 } 2019 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 2020 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 2021 if (ref >= EXT4_XATTR_REFCOUNT_MAX) 2022 ce->e_reusable = 0; 2023 ea_bdebug(new_bh, "reusing; refcount now=%d", 2024 ref); 2025 ext4_xattr_block_csum_set(inode, new_bh); 2026 unlock_buffer(new_bh); 2027 error = ext4_handle_dirty_metadata(handle, 2028 inode, 2029 new_bh); 2030 if (error) 2031 goto cleanup_dquot; 2032 } 2033 mb_cache_entry_touch(ea_block_cache, ce); 2034 mb_cache_entry_put(ea_block_cache, ce); 2035 ce = NULL; 2036 } else if (bs->bh && s->base == bs->bh->b_data) { 2037 /* We were modifying this block in-place. */ 2038 ea_bdebug(bs->bh, "keeping this block"); 2039 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 2040 new_bh = bs->bh; 2041 get_bh(new_bh); 2042 } else { 2043 /* We need to allocate a new block */ 2044 ext4_fsblk_t goal, block; 2045 2046 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2047 2048 goal = ext4_group_first_block_no(sb, 2049 EXT4_I(inode)->i_block_group); 2050 2051 /* non-extent files can't have physical blocks past 2^32 */ 2052 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2053 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; 2054 2055 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2056 NULL, &error); 2057 if (error) 2058 goto cleanup; 2059 2060 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2061 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); 2062 2063 ea_idebug(inode, "creating block %llu", 2064 (unsigned long long)block); 2065 2066 new_bh = sb_getblk(sb, block); 2067 if (unlikely(!new_bh)) { 2068 error = -ENOMEM; 2069 getblk_failed: 2070 ext4_free_blocks(handle, inode, NULL, block, 1, 2071 EXT4_FREE_BLOCKS_METADATA); 2072 goto cleanup; 2073 } 2074 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2075 ENTRY(header(s->base)+1)); 2076 if (error) 2077 goto getblk_failed; 2078 if (ea_inode) { 2079 /* Drop the extra ref on ea_inode. */ 2080 error = ext4_xattr_inode_dec_ref(handle, 2081 ea_inode); 2082 if (error) 2083 ext4_warning_inode(ea_inode, 2084 "dec ref error=%d", 2085 error); 2086 iput(ea_inode); 2087 ea_inode = NULL; 2088 } 2089 2090 lock_buffer(new_bh); 2091 error = ext4_journal_get_create_access(handle, new_bh); 2092 if (error) { 2093 unlock_buffer(new_bh); 2094 error = -EIO; 2095 goto getblk_failed; 2096 } 2097 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2098 ext4_xattr_block_csum_set(inode, new_bh); 2099 set_buffer_uptodate(new_bh); 2100 unlock_buffer(new_bh); 2101 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2102 error = ext4_handle_dirty_metadata(handle, inode, 2103 new_bh); 2104 if (error) 2105 goto cleanup; 2106 } 2107 } 2108 2109 if (old_ea_inode_quota) 2110 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota); 2111 2112 /* Update the inode. */ 2113 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2114 2115 /* Drop the previous xattr block. */ 2116 if (bs->bh && bs->bh != new_bh) { 2117 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2118 2119 ext4_xattr_release_block(handle, inode, bs->bh, 2120 &ea_inode_array, 2121 0 /* extra_credits */); 2122 ext4_xattr_inode_array_free(ea_inode_array); 2123 } 2124 error = 0; 2125 2126 cleanup: 2127 if (ea_inode) { 2128 int error2; 2129 2130 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2131 if (error2) 2132 ext4_warning_inode(ea_inode, "dec ref error=%d", 2133 error2); 2134 2135 /* If there was an error, revert the quota charge. */ 2136 if (error) 2137 ext4_xattr_inode_free_quota(inode, ea_inode, 2138 i_size_read(ea_inode)); 2139 iput(ea_inode); 2140 } 2141 if (ce) 2142 mb_cache_entry_put(ea_block_cache, ce); 2143 brelse(new_bh); 2144 if (!(bs->bh && s->base == bs->bh->b_data)) 2145 kfree(s->base); 2146 2147 return error; 2148 2149 cleanup_dquot: 2150 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2151 goto cleanup; 2152 2153 bad_block: 2154 EXT4_ERROR_INODE(inode, "bad block %llu", 2155 EXT4_I(inode)->i_file_acl); 2156 goto cleanup; 2157 2158 #undef header 2159 } 2160 2161 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2162 struct ext4_xattr_ibody_find *is) 2163 { 2164 struct ext4_xattr_ibody_header *header; 2165 struct ext4_inode *raw_inode; 2166 int error; 2167 2168 if (EXT4_I(inode)->i_extra_isize == 0) 2169 return 0; 2170 raw_inode = ext4_raw_inode(&is->iloc); 2171 header = IHDR(inode, raw_inode); 2172 is->s.base = is->s.first = IFIRST(header); 2173 is->s.here = is->s.first; 2174 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2175 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2176 error = xattr_check_inode(inode, header, is->s.end); 2177 if (error) 2178 return error; 2179 /* Find the named attribute. */ 2180 error = xattr_find_entry(inode, &is->s.here, is->s.end, 2181 i->name_index, i->name, 0); 2182 if (error && error != -ENODATA) 2183 return error; 2184 is->s.not_found = error; 2185 } 2186 return 0; 2187 } 2188 2189 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 2190 struct ext4_xattr_info *i, 2191 struct ext4_xattr_ibody_find *is) 2192 { 2193 struct ext4_xattr_ibody_header *header; 2194 struct ext4_xattr_search *s = &is->s; 2195 int error; 2196 2197 if (EXT4_I(inode)->i_extra_isize == 0) 2198 return -ENOSPC; 2199 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2200 if (error) 2201 return error; 2202 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2203 if (!IS_LAST_ENTRY(s->first)) { 2204 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2205 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2206 } else { 2207 header->h_magic = cpu_to_le32(0); 2208 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2209 } 2210 return 0; 2211 } 2212 2213 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2214 struct ext4_xattr_info *i, 2215 struct ext4_xattr_ibody_find *is) 2216 { 2217 struct ext4_xattr_ibody_header *header; 2218 struct ext4_xattr_search *s = &is->s; 2219 int error; 2220 2221 if (EXT4_I(inode)->i_extra_isize == 0) 2222 return -ENOSPC; 2223 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2224 if (error) 2225 return error; 2226 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2227 if (!IS_LAST_ENTRY(s->first)) { 2228 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2229 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2230 } else { 2231 header->h_magic = cpu_to_le32(0); 2232 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2233 } 2234 return 0; 2235 } 2236 2237 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2238 struct ext4_xattr_info *i) 2239 { 2240 void *value; 2241 2242 /* When e_value_inum is set the value is stored externally. */ 2243 if (s->here->e_value_inum) 2244 return 0; 2245 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2246 return 0; 2247 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2248 return !memcmp(value, i->value, i->value_len); 2249 } 2250 2251 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2252 { 2253 struct buffer_head *bh; 2254 int error; 2255 2256 if (!EXT4_I(inode)->i_file_acl) 2257 return NULL; 2258 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2259 if (IS_ERR(bh)) 2260 return bh; 2261 error = ext4_xattr_check_block(inode, bh); 2262 if (error) { 2263 brelse(bh); 2264 return ERR_PTR(error); 2265 } 2266 return bh; 2267 } 2268 2269 /* 2270 * ext4_xattr_set_handle() 2271 * 2272 * Create, replace or remove an extended attribute for this inode. Value 2273 * is NULL to remove an existing extended attribute, and non-NULL to 2274 * either replace an existing extended attribute, or create a new extended 2275 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2276 * specify that an extended attribute must exist and must not exist 2277 * previous to the call, respectively. 2278 * 2279 * Returns 0, or a negative error number on failure. 2280 */ 2281 int 2282 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2283 const char *name, const void *value, size_t value_len, 2284 int flags) 2285 { 2286 struct ext4_xattr_info i = { 2287 .name_index = name_index, 2288 .name = name, 2289 .value = value, 2290 .value_len = value_len, 2291 .in_inode = 0, 2292 }; 2293 struct ext4_xattr_ibody_find is = { 2294 .s = { .not_found = -ENODATA, }, 2295 }; 2296 struct ext4_xattr_block_find bs = { 2297 .s = { .not_found = -ENODATA, }, 2298 }; 2299 int no_expand; 2300 int error; 2301 2302 if (!name) 2303 return -EINVAL; 2304 if (strlen(name) > 255) 2305 return -ERANGE; 2306 2307 ext4_write_lock_xattr(inode, &no_expand); 2308 2309 /* Check journal credits under write lock. */ 2310 if (ext4_handle_valid(handle)) { 2311 struct buffer_head *bh; 2312 int credits; 2313 2314 bh = ext4_xattr_get_block(inode); 2315 if (IS_ERR(bh)) { 2316 error = PTR_ERR(bh); 2317 goto cleanup; 2318 } 2319 2320 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2321 value_len, 2322 flags & XATTR_CREATE); 2323 brelse(bh); 2324 2325 if (jbd2_handle_buffer_credits(handle) < credits) { 2326 error = -ENOSPC; 2327 goto cleanup; 2328 } 2329 } 2330 2331 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2332 if (error) 2333 goto cleanup; 2334 2335 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2336 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2337 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2338 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2339 } 2340 2341 error = ext4_xattr_ibody_find(inode, &i, &is); 2342 if (error) 2343 goto cleanup; 2344 if (is.s.not_found) 2345 error = ext4_xattr_block_find(inode, &i, &bs); 2346 if (error) 2347 goto cleanup; 2348 if (is.s.not_found && bs.s.not_found) { 2349 error = -ENODATA; 2350 if (flags & XATTR_REPLACE) 2351 goto cleanup; 2352 error = 0; 2353 if (!value) 2354 goto cleanup; 2355 } else { 2356 error = -EEXIST; 2357 if (flags & XATTR_CREATE) 2358 goto cleanup; 2359 } 2360 2361 if (!value) { 2362 if (!is.s.not_found) 2363 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2364 else if (!bs.s.not_found) 2365 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2366 } else { 2367 error = 0; 2368 /* Xattr value did not change? Save us some work and bail out */ 2369 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2370 goto cleanup; 2371 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2372 goto cleanup; 2373 2374 if (ext4_has_feature_ea_inode(inode->i_sb) && 2375 (EXT4_XATTR_SIZE(i.value_len) > 2376 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2377 i.in_inode = 1; 2378 retry_inode: 2379 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2380 if (!error && !bs.s.not_found) { 2381 i.value = NULL; 2382 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2383 } else if (error == -ENOSPC) { 2384 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2385 brelse(bs.bh); 2386 bs.bh = NULL; 2387 error = ext4_xattr_block_find(inode, &i, &bs); 2388 if (error) 2389 goto cleanup; 2390 } 2391 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2392 if (!error && !is.s.not_found) { 2393 i.value = NULL; 2394 error = ext4_xattr_ibody_set(handle, inode, &i, 2395 &is); 2396 } else if (error == -ENOSPC) { 2397 /* 2398 * Xattr does not fit in the block, store at 2399 * external inode if possible. 2400 */ 2401 if (ext4_has_feature_ea_inode(inode->i_sb) && 2402 !i.in_inode) { 2403 i.in_inode = 1; 2404 goto retry_inode; 2405 } 2406 } 2407 } 2408 } 2409 if (!error) { 2410 ext4_xattr_update_super_block(handle, inode->i_sb); 2411 inode->i_ctime = current_time(inode); 2412 if (!value) 2413 no_expand = 0; 2414 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2415 /* 2416 * The bh is consumed by ext4_mark_iloc_dirty, even with 2417 * error != 0. 2418 */ 2419 is.iloc.bh = NULL; 2420 if (IS_SYNC(inode)) 2421 ext4_handle_sync(handle); 2422 } 2423 2424 cleanup: 2425 brelse(is.iloc.bh); 2426 brelse(bs.bh); 2427 ext4_write_unlock_xattr(inode, &no_expand); 2428 return error; 2429 } 2430 2431 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2432 bool is_create, int *credits) 2433 { 2434 struct buffer_head *bh; 2435 int err; 2436 2437 *credits = 0; 2438 2439 if (!EXT4_SB(inode->i_sb)->s_journal) 2440 return 0; 2441 2442 down_read(&EXT4_I(inode)->xattr_sem); 2443 2444 bh = ext4_xattr_get_block(inode); 2445 if (IS_ERR(bh)) { 2446 err = PTR_ERR(bh); 2447 } else { 2448 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2449 value_len, is_create); 2450 brelse(bh); 2451 err = 0; 2452 } 2453 2454 up_read(&EXT4_I(inode)->xattr_sem); 2455 return err; 2456 } 2457 2458 /* 2459 * ext4_xattr_set() 2460 * 2461 * Like ext4_xattr_set_handle, but start from an inode. This extended 2462 * attribute modification is a filesystem transaction by itself. 2463 * 2464 * Returns 0, or a negative error number on failure. 2465 */ 2466 int 2467 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2468 const void *value, size_t value_len, int flags) 2469 { 2470 handle_t *handle; 2471 struct super_block *sb = inode->i_sb; 2472 int error, retries = 0; 2473 int credits; 2474 2475 error = dquot_initialize(inode); 2476 if (error) 2477 return error; 2478 2479 retry: 2480 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2481 &credits); 2482 if (error) 2483 return error; 2484 2485 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2486 if (IS_ERR(handle)) { 2487 error = PTR_ERR(handle); 2488 } else { 2489 int error2; 2490 2491 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2492 value, value_len, flags); 2493 error2 = ext4_journal_stop(handle); 2494 if (error == -ENOSPC && 2495 ext4_should_retry_alloc(sb, &retries)) 2496 goto retry; 2497 if (error == 0) 2498 error = error2; 2499 } 2500 2501 return error; 2502 } 2503 2504 /* 2505 * Shift the EA entries in the inode to create space for the increased 2506 * i_extra_isize. 2507 */ 2508 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2509 int value_offs_shift, void *to, 2510 void *from, size_t n) 2511 { 2512 struct ext4_xattr_entry *last = entry; 2513 int new_offs; 2514 2515 /* We always shift xattr headers further thus offsets get lower */ 2516 BUG_ON(value_offs_shift > 0); 2517 2518 /* Adjust the value offsets of the entries */ 2519 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2520 if (!last->e_value_inum && last->e_value_size) { 2521 new_offs = le16_to_cpu(last->e_value_offs) + 2522 value_offs_shift; 2523 last->e_value_offs = cpu_to_le16(new_offs); 2524 } 2525 } 2526 /* Shift the entries by n bytes */ 2527 memmove(to, from, n); 2528 } 2529 2530 /* 2531 * Move xattr pointed to by 'entry' from inode into external xattr block 2532 */ 2533 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2534 struct ext4_inode *raw_inode, 2535 struct ext4_xattr_entry *entry) 2536 { 2537 struct ext4_xattr_ibody_find *is = NULL; 2538 struct ext4_xattr_block_find *bs = NULL; 2539 char *buffer = NULL, *b_entry_name = NULL; 2540 size_t value_size = le32_to_cpu(entry->e_value_size); 2541 struct ext4_xattr_info i = { 2542 .value = NULL, 2543 .value_len = 0, 2544 .name_index = entry->e_name_index, 2545 .in_inode = !!entry->e_value_inum, 2546 }; 2547 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2548 int error; 2549 2550 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2551 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2552 buffer = kmalloc(value_size, GFP_NOFS); 2553 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2554 if (!is || !bs || !buffer || !b_entry_name) { 2555 error = -ENOMEM; 2556 goto out; 2557 } 2558 2559 is->s.not_found = -ENODATA; 2560 bs->s.not_found = -ENODATA; 2561 is->iloc.bh = NULL; 2562 bs->bh = NULL; 2563 2564 /* Save the entry name and the entry value */ 2565 if (entry->e_value_inum) { 2566 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2567 if (error) 2568 goto out; 2569 } else { 2570 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2571 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2572 } 2573 2574 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2575 b_entry_name[entry->e_name_len] = '\0'; 2576 i.name = b_entry_name; 2577 2578 error = ext4_get_inode_loc(inode, &is->iloc); 2579 if (error) 2580 goto out; 2581 2582 error = ext4_xattr_ibody_find(inode, &i, is); 2583 if (error) 2584 goto out; 2585 2586 /* Remove the chosen entry from the inode */ 2587 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2588 if (error) 2589 goto out; 2590 2591 i.value = buffer; 2592 i.value_len = value_size; 2593 error = ext4_xattr_block_find(inode, &i, bs); 2594 if (error) 2595 goto out; 2596 2597 /* Add entry which was removed from the inode into the block */ 2598 error = ext4_xattr_block_set(handle, inode, &i, bs); 2599 if (error) 2600 goto out; 2601 error = 0; 2602 out: 2603 kfree(b_entry_name); 2604 kfree(buffer); 2605 if (is) 2606 brelse(is->iloc.bh); 2607 if (bs) 2608 brelse(bs->bh); 2609 kfree(is); 2610 kfree(bs); 2611 2612 return error; 2613 } 2614 2615 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2616 struct ext4_inode *raw_inode, 2617 int isize_diff, size_t ifree, 2618 size_t bfree, int *total_ino) 2619 { 2620 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2621 struct ext4_xattr_entry *small_entry; 2622 struct ext4_xattr_entry *entry; 2623 struct ext4_xattr_entry *last; 2624 unsigned int entry_size; /* EA entry size */ 2625 unsigned int total_size; /* EA entry size + value size */ 2626 unsigned int min_total_size; 2627 int error; 2628 2629 while (isize_diff > ifree) { 2630 entry = NULL; 2631 small_entry = NULL; 2632 min_total_size = ~0U; 2633 last = IFIRST(header); 2634 /* Find the entry best suited to be pushed into EA block */ 2635 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2636 /* never move system.data out of the inode */ 2637 if ((last->e_name_len == 4) && 2638 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) && 2639 !memcmp(last->e_name, "data", 4)) 2640 continue; 2641 total_size = EXT4_XATTR_LEN(last->e_name_len); 2642 if (!last->e_value_inum) 2643 total_size += EXT4_XATTR_SIZE( 2644 le32_to_cpu(last->e_value_size)); 2645 if (total_size <= bfree && 2646 total_size < min_total_size) { 2647 if (total_size + ifree < isize_diff) { 2648 small_entry = last; 2649 } else { 2650 entry = last; 2651 min_total_size = total_size; 2652 } 2653 } 2654 } 2655 2656 if (entry == NULL) { 2657 if (small_entry == NULL) 2658 return -ENOSPC; 2659 entry = small_entry; 2660 } 2661 2662 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2663 total_size = entry_size; 2664 if (!entry->e_value_inum) 2665 total_size += EXT4_XATTR_SIZE( 2666 le32_to_cpu(entry->e_value_size)); 2667 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2668 entry); 2669 if (error) 2670 return error; 2671 2672 *total_ino -= entry_size; 2673 ifree += total_size; 2674 bfree -= total_size; 2675 } 2676 2677 return 0; 2678 } 2679 2680 /* 2681 * Expand an inode by new_extra_isize bytes when EAs are present. 2682 * Returns 0 on success or negative error number on failure. 2683 */ 2684 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2685 struct ext4_inode *raw_inode, handle_t *handle) 2686 { 2687 struct ext4_xattr_ibody_header *header; 2688 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2689 static unsigned int mnt_count; 2690 size_t min_offs; 2691 size_t ifree, bfree; 2692 int total_ino; 2693 void *base, *end; 2694 int error = 0, tried_min_extra_isize = 0; 2695 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2696 int isize_diff; /* How much do we need to grow i_extra_isize */ 2697 2698 retry: 2699 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2700 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2701 return 0; 2702 2703 header = IHDR(inode, raw_inode); 2704 2705 /* 2706 * Check if enough free space is available in the inode to shift the 2707 * entries ahead by new_extra_isize. 2708 */ 2709 2710 base = IFIRST(header); 2711 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2712 min_offs = end - base; 2713 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32); 2714 2715 error = xattr_check_inode(inode, header, end); 2716 if (error) 2717 goto cleanup; 2718 2719 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2720 if (ifree >= isize_diff) 2721 goto shift; 2722 2723 /* 2724 * Enough free space isn't available in the inode, check if 2725 * EA block can hold new_extra_isize bytes. 2726 */ 2727 if (EXT4_I(inode)->i_file_acl) { 2728 struct buffer_head *bh; 2729 2730 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2731 if (IS_ERR(bh)) { 2732 error = PTR_ERR(bh); 2733 goto cleanup; 2734 } 2735 error = ext4_xattr_check_block(inode, bh); 2736 if (error) { 2737 brelse(bh); 2738 goto cleanup; 2739 } 2740 base = BHDR(bh); 2741 end = bh->b_data + bh->b_size; 2742 min_offs = end - base; 2743 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2744 NULL); 2745 brelse(bh); 2746 if (bfree + ifree < isize_diff) { 2747 if (!tried_min_extra_isize && s_min_extra_isize) { 2748 tried_min_extra_isize++; 2749 new_extra_isize = s_min_extra_isize; 2750 goto retry; 2751 } 2752 error = -ENOSPC; 2753 goto cleanup; 2754 } 2755 } else { 2756 bfree = inode->i_sb->s_blocksize; 2757 } 2758 2759 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2760 isize_diff, ifree, bfree, 2761 &total_ino); 2762 if (error) { 2763 if (error == -ENOSPC && !tried_min_extra_isize && 2764 s_min_extra_isize) { 2765 tried_min_extra_isize++; 2766 new_extra_isize = s_min_extra_isize; 2767 goto retry; 2768 } 2769 goto cleanup; 2770 } 2771 shift: 2772 /* Adjust the offsets and shift the remaining entries ahead */ 2773 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2774 - new_extra_isize, (void *)raw_inode + 2775 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2776 (void *)header, total_ino); 2777 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2778 2779 cleanup: 2780 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2781 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2782 inode->i_ino); 2783 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2784 } 2785 return error; 2786 } 2787 2788 #define EIA_INCR 16 /* must be 2^n */ 2789 #define EIA_MASK (EIA_INCR - 1) 2790 2791 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2792 * If @ea_inode_array is new or full it will be grown and the old 2793 * contents copied over. 2794 */ 2795 static int 2796 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2797 struct inode *inode) 2798 { 2799 if (*ea_inode_array == NULL) { 2800 /* 2801 * Start with 15 inodes, so it fits into a power-of-two size. 2802 * If *ea_inode_array is NULL, this is essentially offsetof() 2803 */ 2804 (*ea_inode_array) = 2805 kmalloc(offsetof(struct ext4_xattr_inode_array, 2806 inodes[EIA_MASK]), 2807 GFP_NOFS); 2808 if (*ea_inode_array == NULL) 2809 return -ENOMEM; 2810 (*ea_inode_array)->count = 0; 2811 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2812 /* expand the array once all 15 + n * 16 slots are full */ 2813 struct ext4_xattr_inode_array *new_array = NULL; 2814 int count = (*ea_inode_array)->count; 2815 2816 /* if new_array is NULL, this is essentially offsetof() */ 2817 new_array = kmalloc( 2818 offsetof(struct ext4_xattr_inode_array, 2819 inodes[count + EIA_INCR]), 2820 GFP_NOFS); 2821 if (new_array == NULL) 2822 return -ENOMEM; 2823 memcpy(new_array, *ea_inode_array, 2824 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2825 kfree(*ea_inode_array); 2826 *ea_inode_array = new_array; 2827 } 2828 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2829 return 0; 2830 } 2831 2832 /* 2833 * ext4_xattr_delete_inode() 2834 * 2835 * Free extended attribute resources associated with this inode. Traverse 2836 * all entries and decrement reference on any xattr inodes associated with this 2837 * inode. This is called immediately before an inode is freed. We have exclusive 2838 * access to the inode. If an orphan inode is deleted it will also release its 2839 * references on xattr block and xattr inodes. 2840 */ 2841 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2842 struct ext4_xattr_inode_array **ea_inode_array, 2843 int extra_credits) 2844 { 2845 struct buffer_head *bh = NULL; 2846 struct ext4_xattr_ibody_header *header; 2847 struct ext4_iloc iloc = { .bh = NULL }; 2848 struct ext4_xattr_entry *entry; 2849 struct inode *ea_inode; 2850 int error; 2851 2852 error = ext4_journal_ensure_credits(handle, extra_credits, 2853 ext4_free_metadata_revoke_credits(inode->i_sb, 1)); 2854 if (error < 0) { 2855 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2856 goto cleanup; 2857 } 2858 2859 if (ext4_has_feature_ea_inode(inode->i_sb) && 2860 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2861 2862 error = ext4_get_inode_loc(inode, &iloc); 2863 if (error) { 2864 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2865 goto cleanup; 2866 } 2867 2868 error = ext4_journal_get_write_access(handle, iloc.bh); 2869 if (error) { 2870 EXT4_ERROR_INODE(inode, "write access (error %d)", 2871 error); 2872 goto cleanup; 2873 } 2874 2875 header = IHDR(inode, ext4_raw_inode(&iloc)); 2876 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2877 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2878 IFIRST(header), 2879 false /* block_csum */, 2880 ea_inode_array, 2881 extra_credits, 2882 false /* skip_quota */); 2883 } 2884 2885 if (EXT4_I(inode)->i_file_acl) { 2886 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2887 if (IS_ERR(bh)) { 2888 error = PTR_ERR(bh); 2889 if (error == -EIO) { 2890 EXT4_ERROR_INODE_ERR(inode, EIO, 2891 "block %llu read error", 2892 EXT4_I(inode)->i_file_acl); 2893 } 2894 bh = NULL; 2895 goto cleanup; 2896 } 2897 error = ext4_xattr_check_block(inode, bh); 2898 if (error) 2899 goto cleanup; 2900 2901 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2902 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2903 entry = EXT4_XATTR_NEXT(entry)) { 2904 if (!entry->e_value_inum) 2905 continue; 2906 error = ext4_xattr_inode_iget(inode, 2907 le32_to_cpu(entry->e_value_inum), 2908 le32_to_cpu(entry->e_hash), 2909 &ea_inode); 2910 if (error) 2911 continue; 2912 ext4_xattr_inode_free_quota(inode, ea_inode, 2913 le32_to_cpu(entry->e_value_size)); 2914 iput(ea_inode); 2915 } 2916 2917 } 2918 2919 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2920 extra_credits); 2921 /* 2922 * Update i_file_acl value in the same transaction that releases 2923 * block. 2924 */ 2925 EXT4_I(inode)->i_file_acl = 0; 2926 error = ext4_mark_inode_dirty(handle, inode); 2927 if (error) { 2928 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2929 error); 2930 goto cleanup; 2931 } 2932 } 2933 error = 0; 2934 cleanup: 2935 brelse(iloc.bh); 2936 brelse(bh); 2937 return error; 2938 } 2939 2940 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2941 { 2942 int idx; 2943 2944 if (ea_inode_array == NULL) 2945 return; 2946 2947 for (idx = 0; idx < ea_inode_array->count; ++idx) 2948 iput(ea_inode_array->inodes[idx]); 2949 kfree(ea_inode_array); 2950 } 2951 2952 /* 2953 * ext4_xattr_block_cache_insert() 2954 * 2955 * Create a new entry in the extended attribute block cache, and insert 2956 * it unless such an entry is already in the cache. 2957 * 2958 * Returns 0, or a negative error number on failure. 2959 */ 2960 static void 2961 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2962 struct buffer_head *bh) 2963 { 2964 struct ext4_xattr_header *header = BHDR(bh); 2965 __u32 hash = le32_to_cpu(header->h_hash); 2966 int reusable = le32_to_cpu(header->h_refcount) < 2967 EXT4_XATTR_REFCOUNT_MAX; 2968 int error; 2969 2970 if (!ea_block_cache) 2971 return; 2972 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2973 bh->b_blocknr, reusable); 2974 if (error) { 2975 if (error == -EBUSY) 2976 ea_bdebug(bh, "already in cache"); 2977 } else 2978 ea_bdebug(bh, "inserting [%x]", (int)hash); 2979 } 2980 2981 /* 2982 * ext4_xattr_cmp() 2983 * 2984 * Compare two extended attribute blocks for equality. 2985 * 2986 * Returns 0 if the blocks are equal, 1 if they differ, and 2987 * a negative error number on errors. 2988 */ 2989 static int 2990 ext4_xattr_cmp(struct ext4_xattr_header *header1, 2991 struct ext4_xattr_header *header2) 2992 { 2993 struct ext4_xattr_entry *entry1, *entry2; 2994 2995 entry1 = ENTRY(header1+1); 2996 entry2 = ENTRY(header2+1); 2997 while (!IS_LAST_ENTRY(entry1)) { 2998 if (IS_LAST_ENTRY(entry2)) 2999 return 1; 3000 if (entry1->e_hash != entry2->e_hash || 3001 entry1->e_name_index != entry2->e_name_index || 3002 entry1->e_name_len != entry2->e_name_len || 3003 entry1->e_value_size != entry2->e_value_size || 3004 entry1->e_value_inum != entry2->e_value_inum || 3005 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 3006 return 1; 3007 if (!entry1->e_value_inum && 3008 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 3009 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 3010 le32_to_cpu(entry1->e_value_size))) 3011 return 1; 3012 3013 entry1 = EXT4_XATTR_NEXT(entry1); 3014 entry2 = EXT4_XATTR_NEXT(entry2); 3015 } 3016 if (!IS_LAST_ENTRY(entry2)) 3017 return 1; 3018 return 0; 3019 } 3020 3021 /* 3022 * ext4_xattr_block_cache_find() 3023 * 3024 * Find an identical extended attribute block. 3025 * 3026 * Returns a pointer to the block found, or NULL if such a block was 3027 * not found or an error occurred. 3028 */ 3029 static struct buffer_head * 3030 ext4_xattr_block_cache_find(struct inode *inode, 3031 struct ext4_xattr_header *header, 3032 struct mb_cache_entry **pce) 3033 { 3034 __u32 hash = le32_to_cpu(header->h_hash); 3035 struct mb_cache_entry *ce; 3036 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 3037 3038 if (!ea_block_cache) 3039 return NULL; 3040 if (!header->h_hash) 3041 return NULL; /* never share */ 3042 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 3043 ce = mb_cache_entry_find_first(ea_block_cache, hash); 3044 while (ce) { 3045 struct buffer_head *bh; 3046 3047 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO); 3048 if (IS_ERR(bh)) { 3049 if (PTR_ERR(bh) == -ENOMEM) 3050 return NULL; 3051 bh = NULL; 3052 EXT4_ERROR_INODE(inode, "block %lu read error", 3053 (unsigned long)ce->e_value); 3054 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 3055 *pce = ce; 3056 return bh; 3057 } 3058 brelse(bh); 3059 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3060 } 3061 return NULL; 3062 } 3063 3064 #define NAME_HASH_SHIFT 5 3065 #define VALUE_HASH_SHIFT 16 3066 3067 /* 3068 * ext4_xattr_hash_entry() 3069 * 3070 * Compute the hash of an extended attribute. 3071 */ 3072 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3073 size_t value_count) 3074 { 3075 __u32 hash = 0; 3076 3077 while (name_len--) { 3078 hash = (hash << NAME_HASH_SHIFT) ^ 3079 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3080 *name++; 3081 } 3082 while (value_count--) { 3083 hash = (hash << VALUE_HASH_SHIFT) ^ 3084 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3085 le32_to_cpu(*value++); 3086 } 3087 return cpu_to_le32(hash); 3088 } 3089 3090 #undef NAME_HASH_SHIFT 3091 #undef VALUE_HASH_SHIFT 3092 3093 #define BLOCK_HASH_SHIFT 16 3094 3095 /* 3096 * ext4_xattr_rehash() 3097 * 3098 * Re-compute the extended attribute hash value after an entry has changed. 3099 */ 3100 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3101 { 3102 struct ext4_xattr_entry *here; 3103 __u32 hash = 0; 3104 3105 here = ENTRY(header+1); 3106 while (!IS_LAST_ENTRY(here)) { 3107 if (!here->e_hash) { 3108 /* Block is not shared if an entry's hash value == 0 */ 3109 hash = 0; 3110 break; 3111 } 3112 hash = (hash << BLOCK_HASH_SHIFT) ^ 3113 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3114 le32_to_cpu(here->e_hash); 3115 here = EXT4_XATTR_NEXT(here); 3116 } 3117 header->h_hash = cpu_to_le32(hash); 3118 } 3119 3120 #undef BLOCK_HASH_SHIFT 3121 3122 #define HASH_BUCKET_BITS 10 3123 3124 struct mb_cache * 3125 ext4_xattr_create_cache(void) 3126 { 3127 return mb_cache_create(HASH_BUCKET_BITS); 3128 } 3129 3130 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3131 { 3132 if (cache) 3133 mb_cache_destroy(cache); 3134 } 3135 3136