1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext4/xattr.c 4 * 5 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 6 * 7 * Fix by Harrison Xing <harrison@mountainviewdata.com>. 8 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>. 9 * Extended attributes for symlinks and special files added per 10 * suggestion of Luka Renko <luka.renko@hermes.si>. 11 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, 12 * Red Hat Inc. 13 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz 14 * and Andreas Gruenbacher <agruen@suse.de>. 15 */ 16 17 /* 18 * Extended attributes are stored directly in inodes (on file systems with 19 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl 20 * field contains the block number if an inode uses an additional block. All 21 * attributes must fit in the inode and one additional block. Blocks that 22 * contain the identical set of attributes may be shared among several inodes. 23 * Identical blocks are detected by keeping a cache of blocks that have 24 * recently been accessed. 25 * 26 * The attributes in inodes and on blocks have a different header; the entries 27 * are stored in the same format: 28 * 29 * +------------------+ 30 * | header | 31 * | entry 1 | | 32 * | entry 2 | | growing downwards 33 * | entry 3 | v 34 * | four null bytes | 35 * | . . . | 36 * | value 1 | ^ 37 * | value 3 | | growing upwards 38 * | value 2 | | 39 * +------------------+ 40 * 41 * The header is followed by multiple entry descriptors. In disk blocks, the 42 * entry descriptors are kept sorted. In inodes, they are unsorted. The 43 * attribute values are aligned to the end of the block in no specific order. 44 * 45 * Locking strategy 46 * ---------------- 47 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem. 48 * EA blocks are only changed if they are exclusive to an inode, so 49 * holding xattr_sem also means that nothing but the EA block's reference 50 * count can change. Multiple writers to the same block are synchronized 51 * by the buffer lock. 52 */ 53 54 #include <linux/init.h> 55 #include <linux/fs.h> 56 #include <linux/slab.h> 57 #include <linux/mbcache.h> 58 #include <linux/quotaops.h> 59 #include <linux/iversion.h> 60 #include "ext4_jbd2.h" 61 #include "ext4.h" 62 #include "xattr.h" 63 #include "acl.h" 64 65 #ifdef EXT4_XATTR_DEBUG 66 # define ea_idebug(inode, fmt, ...) \ 67 printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \ 68 inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__) 69 # define ea_bdebug(bh, fmt, ...) \ 70 printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \ 71 bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__) 72 #else 73 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 74 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 75 #endif 76 77 static void ext4_xattr_block_cache_insert(struct mb_cache *, 78 struct buffer_head *); 79 static struct buffer_head * 80 ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *, 81 struct mb_cache_entry **); 82 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 83 size_t value_count); 84 static void ext4_xattr_rehash(struct ext4_xattr_header *); 85 86 static const struct xattr_handler * const ext4_xattr_handler_map[] = { 87 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, 88 #ifdef CONFIG_EXT4_FS_POSIX_ACL 89 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 90 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 91 #endif 92 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, 93 #ifdef CONFIG_EXT4_FS_SECURITY 94 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, 95 #endif 96 }; 97 98 const struct xattr_handler *ext4_xattr_handlers[] = { 99 &ext4_xattr_user_handler, 100 &ext4_xattr_trusted_handler, 101 #ifdef CONFIG_EXT4_FS_POSIX_ACL 102 &posix_acl_access_xattr_handler, 103 &posix_acl_default_xattr_handler, 104 #endif 105 #ifdef CONFIG_EXT4_FS_SECURITY 106 &ext4_xattr_security_handler, 107 #endif 108 NULL 109 }; 110 111 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ 112 inode->i_sb->s_fs_info)->s_ea_block_cache) 113 114 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \ 115 inode->i_sb->s_fs_info)->s_ea_inode_cache) 116 117 static int 118 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 119 struct inode *inode); 120 121 #ifdef CONFIG_LOCKDEP 122 void ext4_xattr_inode_set_class(struct inode *ea_inode) 123 { 124 lockdep_set_subclass(&ea_inode->i_rwsem, 1); 125 } 126 #endif 127 128 static __le32 ext4_xattr_block_csum(struct inode *inode, 129 sector_t block_nr, 130 struct ext4_xattr_header *hdr) 131 { 132 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 133 __u32 csum; 134 __le64 dsk_block_nr = cpu_to_le64(block_nr); 135 __u32 dummy_csum = 0; 136 int offset = offsetof(struct ext4_xattr_header, h_checksum); 137 138 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr, 139 sizeof(dsk_block_nr)); 140 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset); 141 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 142 offset += sizeof(dummy_csum); 143 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset, 144 EXT4_BLOCK_SIZE(inode->i_sb) - offset); 145 146 return cpu_to_le32(csum); 147 } 148 149 static int ext4_xattr_block_csum_verify(struct inode *inode, 150 struct buffer_head *bh) 151 { 152 struct ext4_xattr_header *hdr = BHDR(bh); 153 int ret = 1; 154 155 if (ext4_has_metadata_csum(inode->i_sb)) { 156 lock_buffer(bh); 157 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, 158 bh->b_blocknr, hdr)); 159 unlock_buffer(bh); 160 } 161 return ret; 162 } 163 164 static void ext4_xattr_block_csum_set(struct inode *inode, 165 struct buffer_head *bh) 166 { 167 if (ext4_has_metadata_csum(inode->i_sb)) 168 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, 169 bh->b_blocknr, BHDR(bh)); 170 } 171 172 static inline const struct xattr_handler * 173 ext4_xattr_handler(int name_index) 174 { 175 const struct xattr_handler *handler = NULL; 176 177 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) 178 handler = ext4_xattr_handler_map[name_index]; 179 return handler; 180 } 181 182 static int 183 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, 184 void *value_start) 185 { 186 struct ext4_xattr_entry *e = entry; 187 188 /* Find the end of the names list */ 189 while (!IS_LAST_ENTRY(e)) { 190 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); 191 if ((void *)next >= end) 192 return -EFSCORRUPTED; 193 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) 194 return -EFSCORRUPTED; 195 e = next; 196 } 197 198 /* Check the values */ 199 while (!IS_LAST_ENTRY(entry)) { 200 u32 size = le32_to_cpu(entry->e_value_size); 201 202 if (size > EXT4_XATTR_SIZE_MAX) 203 return -EFSCORRUPTED; 204 205 if (size != 0 && entry->e_value_inum == 0) { 206 u16 offs = le16_to_cpu(entry->e_value_offs); 207 void *value; 208 209 /* 210 * The value cannot overlap the names, and the value 211 * with padding cannot extend beyond 'end'. Check both 212 * the padded and unpadded sizes, since the size may 213 * overflow to 0 when adding padding. 214 */ 215 if (offs > end - value_start) 216 return -EFSCORRUPTED; 217 value = value_start + offs; 218 if (value < (void *)e + sizeof(u32) || 219 size > end - value || 220 EXT4_XATTR_SIZE(size) > end - value) 221 return -EFSCORRUPTED; 222 } 223 entry = EXT4_XATTR_NEXT(entry); 224 } 225 226 return 0; 227 } 228 229 static inline int 230 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, 231 const char *function, unsigned int line) 232 { 233 int error = -EFSCORRUPTED; 234 235 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || 236 BHDR(bh)->h_blocks != cpu_to_le32(1)) 237 goto errout; 238 if (buffer_verified(bh)) 239 return 0; 240 241 error = -EFSBADCRC; 242 if (!ext4_xattr_block_csum_verify(inode, bh)) 243 goto errout; 244 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, 245 bh->b_data); 246 errout: 247 if (error) 248 __ext4_error_inode(inode, function, line, 0, 249 "corrupted xattr block %llu", 250 (unsigned long long) bh->b_blocknr); 251 else 252 set_buffer_verified(bh); 253 return error; 254 } 255 256 #define ext4_xattr_check_block(inode, bh) \ 257 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) 258 259 260 static int 261 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, 262 void *end, const char *function, unsigned int line) 263 { 264 int error = -EFSCORRUPTED; 265 266 if (end - (void *)header < sizeof(*header) + sizeof(u32) || 267 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC))) 268 goto errout; 269 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header)); 270 errout: 271 if (error) 272 __ext4_error_inode(inode, function, line, 0, 273 "corrupted in-inode xattr"); 274 return error; 275 } 276 277 #define xattr_check_inode(inode, header, end) \ 278 __xattr_check_inode((inode), (header), (end), __func__, __LINE__) 279 280 static int 281 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, 282 void *end, int name_index, const char *name, int sorted) 283 { 284 struct ext4_xattr_entry *entry, *next; 285 size_t name_len; 286 int cmp = 1; 287 288 if (name == NULL) 289 return -EINVAL; 290 name_len = strlen(name); 291 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { 292 next = EXT4_XATTR_NEXT(entry); 293 if ((void *) next >= end) { 294 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 295 return -EFSCORRUPTED; 296 } 297 cmp = name_index - entry->e_name_index; 298 if (!cmp) 299 cmp = name_len - entry->e_name_len; 300 if (!cmp) 301 cmp = memcmp(name, entry->e_name, name_len); 302 if (cmp <= 0 && (sorted || cmp == 0)) 303 break; 304 } 305 *pentry = entry; 306 return cmp ? -ENODATA : 0; 307 } 308 309 static u32 310 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size) 311 { 312 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size); 313 } 314 315 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode) 316 { 317 return ((u64)ea_inode->i_ctime.tv_sec << 32) | 318 (u32) inode_peek_iversion_raw(ea_inode); 319 } 320 321 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count) 322 { 323 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32); 324 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff); 325 } 326 327 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode) 328 { 329 return (u32)ea_inode->i_atime.tv_sec; 330 } 331 332 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash) 333 { 334 ea_inode->i_atime.tv_sec = hash; 335 } 336 337 /* 338 * Read the EA value from an inode. 339 */ 340 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) 341 { 342 int blocksize = 1 << ea_inode->i_blkbits; 343 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits; 344 int tail_size = (size % blocksize) ?: blocksize; 345 struct buffer_head *bhs_inline[8]; 346 struct buffer_head **bhs = bhs_inline; 347 int i, ret; 348 349 if (bh_count > ARRAY_SIZE(bhs_inline)) { 350 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS); 351 if (!bhs) 352 return -ENOMEM; 353 } 354 355 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count, 356 true /* wait */, bhs); 357 if (ret) 358 goto free_bhs; 359 360 for (i = 0; i < bh_count; i++) { 361 /* There shouldn't be any holes in ea_inode. */ 362 if (!bhs[i]) { 363 ret = -EFSCORRUPTED; 364 goto put_bhs; 365 } 366 memcpy((char *)buf + blocksize * i, bhs[i]->b_data, 367 i < bh_count - 1 ? blocksize : tail_size); 368 } 369 ret = 0; 370 put_bhs: 371 for (i = 0; i < bh_count; i++) 372 brelse(bhs[i]); 373 free_bhs: 374 if (bhs != bhs_inline) 375 kfree(bhs); 376 return ret; 377 } 378 379 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec) 380 381 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, 382 u32 ea_inode_hash, struct inode **ea_inode) 383 { 384 struct inode *inode; 385 int err; 386 387 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL); 388 if (IS_ERR(inode)) { 389 err = PTR_ERR(inode); 390 ext4_error(parent->i_sb, 391 "error while reading EA inode %lu err=%d", ea_ino, 392 err); 393 return err; 394 } 395 396 if (is_bad_inode(inode)) { 397 ext4_error(parent->i_sb, 398 "error while reading EA inode %lu is_bad_inode", 399 ea_ino); 400 err = -EIO; 401 goto error; 402 } 403 404 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { 405 ext4_error(parent->i_sb, 406 "EA inode %lu does not have EXT4_EA_INODE_FL flag", 407 ea_ino); 408 err = -EINVAL; 409 goto error; 410 } 411 412 ext4_xattr_inode_set_class(inode); 413 414 /* 415 * Check whether this is an old Lustre-style xattr inode. Lustre 416 * implementation does not have hash validation, rather it has a 417 * backpointer from ea_inode to the parent inode. 418 */ 419 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) && 420 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino && 421 inode->i_generation == parent->i_generation) { 422 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE); 423 ext4_xattr_inode_set_ref(inode, 1); 424 } else { 425 inode_lock(inode); 426 inode->i_flags |= S_NOQUOTA; 427 inode_unlock(inode); 428 } 429 430 *ea_inode = inode; 431 return 0; 432 error: 433 iput(inode); 434 return err; 435 } 436 437 static int 438 ext4_xattr_inode_verify_hashes(struct inode *ea_inode, 439 struct ext4_xattr_entry *entry, void *buffer, 440 size_t size) 441 { 442 u32 hash; 443 444 /* Verify stored hash matches calculated hash. */ 445 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size); 446 if (hash != ext4_xattr_inode_get_hash(ea_inode)) 447 return -EFSCORRUPTED; 448 449 if (entry) { 450 __le32 e_hash, tmp_data; 451 452 /* Verify entry hash. */ 453 tmp_data = cpu_to_le32(hash); 454 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len, 455 &tmp_data, 1); 456 if (e_hash != entry->e_hash) 457 return -EFSCORRUPTED; 458 } 459 return 0; 460 } 461 462 /* 463 * Read xattr value from the EA inode. 464 */ 465 static int 466 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry, 467 void *buffer, size_t size) 468 { 469 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 470 struct inode *ea_inode; 471 int err; 472 473 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum), 474 le32_to_cpu(entry->e_hash), &ea_inode); 475 if (err) { 476 ea_inode = NULL; 477 goto out; 478 } 479 480 if (i_size_read(ea_inode) != size) { 481 ext4_warning_inode(ea_inode, 482 "ea_inode file size=%llu entry size=%zu", 483 i_size_read(ea_inode), size); 484 err = -EFSCORRUPTED; 485 goto out; 486 } 487 488 err = ext4_xattr_inode_read(ea_inode, buffer, size); 489 if (err) 490 goto out; 491 492 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) { 493 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer, 494 size); 495 if (err) { 496 ext4_warning_inode(ea_inode, 497 "EA inode hash validation failed"); 498 goto out; 499 } 500 501 if (ea_inode_cache) 502 mb_cache_entry_create(ea_inode_cache, GFP_NOFS, 503 ext4_xattr_inode_get_hash(ea_inode), 504 ea_inode->i_ino, true /* reusable */); 505 } 506 out: 507 iput(ea_inode); 508 return err; 509 } 510 511 static int 512 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, 513 void *buffer, size_t buffer_size) 514 { 515 struct buffer_head *bh = NULL; 516 struct ext4_xattr_entry *entry; 517 size_t size; 518 void *end; 519 int error; 520 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 521 522 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 523 name_index, name, buffer, (long)buffer_size); 524 525 if (!EXT4_I(inode)->i_file_acl) 526 return -ENODATA; 527 ea_idebug(inode, "reading block %llu", 528 (unsigned long long)EXT4_I(inode)->i_file_acl); 529 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 530 if (IS_ERR(bh)) 531 return PTR_ERR(bh); 532 ea_bdebug(bh, "b_count=%d, refcount=%d", 533 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 534 error = ext4_xattr_check_block(inode, bh); 535 if (error) 536 goto cleanup; 537 ext4_xattr_block_cache_insert(ea_block_cache, bh); 538 entry = BFIRST(bh); 539 end = bh->b_data + bh->b_size; 540 error = xattr_find_entry(inode, &entry, end, name_index, name, 1); 541 if (error) 542 goto cleanup; 543 size = le32_to_cpu(entry->e_value_size); 544 error = -ERANGE; 545 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 546 goto cleanup; 547 if (buffer) { 548 if (size > buffer_size) 549 goto cleanup; 550 if (entry->e_value_inum) { 551 error = ext4_xattr_inode_get(inode, entry, buffer, 552 size); 553 if (error) 554 goto cleanup; 555 } else { 556 u16 offset = le16_to_cpu(entry->e_value_offs); 557 void *p = bh->b_data + offset; 558 559 if (unlikely(p + size > end)) 560 goto cleanup; 561 memcpy(buffer, p, size); 562 } 563 } 564 error = size; 565 566 cleanup: 567 brelse(bh); 568 return error; 569 } 570 571 int 572 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 573 void *buffer, size_t buffer_size) 574 { 575 struct ext4_xattr_ibody_header *header; 576 struct ext4_xattr_entry *entry; 577 struct ext4_inode *raw_inode; 578 struct ext4_iloc iloc; 579 size_t size; 580 void *end; 581 int error; 582 583 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 584 return -ENODATA; 585 error = ext4_get_inode_loc(inode, &iloc); 586 if (error) 587 return error; 588 raw_inode = ext4_raw_inode(&iloc); 589 header = IHDR(inode, raw_inode); 590 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 591 error = xattr_check_inode(inode, header, end); 592 if (error) 593 goto cleanup; 594 entry = IFIRST(header); 595 error = xattr_find_entry(inode, &entry, end, name_index, name, 0); 596 if (error) 597 goto cleanup; 598 size = le32_to_cpu(entry->e_value_size); 599 error = -ERANGE; 600 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 601 goto cleanup; 602 if (buffer) { 603 if (size > buffer_size) 604 goto cleanup; 605 if (entry->e_value_inum) { 606 error = ext4_xattr_inode_get(inode, entry, buffer, 607 size); 608 if (error) 609 goto cleanup; 610 } else { 611 u16 offset = le16_to_cpu(entry->e_value_offs); 612 void *p = (void *)IFIRST(header) + offset; 613 614 if (unlikely(p + size > end)) 615 goto cleanup; 616 memcpy(buffer, p, size); 617 } 618 } 619 error = size; 620 621 cleanup: 622 brelse(iloc.bh); 623 return error; 624 } 625 626 /* 627 * ext4_xattr_get() 628 * 629 * Copy an extended attribute into the buffer 630 * provided, or compute the buffer size required. 631 * Buffer is NULL to compute the size of the buffer required. 632 * 633 * Returns a negative error number on failure, or the number of bytes 634 * used / required on success. 635 */ 636 int 637 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 638 void *buffer, size_t buffer_size) 639 { 640 int error; 641 642 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 643 return -EIO; 644 645 if (strlen(name) > 255) 646 return -ERANGE; 647 648 down_read(&EXT4_I(inode)->xattr_sem); 649 error = ext4_xattr_ibody_get(inode, name_index, name, buffer, 650 buffer_size); 651 if (error == -ENODATA) 652 error = ext4_xattr_block_get(inode, name_index, name, buffer, 653 buffer_size); 654 up_read(&EXT4_I(inode)->xattr_sem); 655 return error; 656 } 657 658 static int 659 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, 660 char *buffer, size_t buffer_size) 661 { 662 size_t rest = buffer_size; 663 664 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 665 const struct xattr_handler *handler = 666 ext4_xattr_handler(entry->e_name_index); 667 668 if (handler && (!handler->list || handler->list(dentry))) { 669 const char *prefix = handler->prefix ?: handler->name; 670 size_t prefix_len = strlen(prefix); 671 size_t size = prefix_len + entry->e_name_len + 1; 672 673 if (buffer) { 674 if (size > rest) 675 return -ERANGE; 676 memcpy(buffer, prefix, prefix_len); 677 buffer += prefix_len; 678 memcpy(buffer, entry->e_name, entry->e_name_len); 679 buffer += entry->e_name_len; 680 *buffer++ = 0; 681 } 682 rest -= size; 683 } 684 } 685 return buffer_size - rest; /* total size */ 686 } 687 688 static int 689 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) 690 { 691 struct inode *inode = d_inode(dentry); 692 struct buffer_head *bh = NULL; 693 int error; 694 695 ea_idebug(inode, "buffer=%p, buffer_size=%ld", 696 buffer, (long)buffer_size); 697 698 if (!EXT4_I(inode)->i_file_acl) 699 return 0; 700 ea_idebug(inode, "reading block %llu", 701 (unsigned long long)EXT4_I(inode)->i_file_acl); 702 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 703 if (IS_ERR(bh)) 704 return PTR_ERR(bh); 705 ea_bdebug(bh, "b_count=%d, refcount=%d", 706 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 707 error = ext4_xattr_check_block(inode, bh); 708 if (error) 709 goto cleanup; 710 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); 711 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, 712 buffer_size); 713 cleanup: 714 brelse(bh); 715 return error; 716 } 717 718 static int 719 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 720 { 721 struct inode *inode = d_inode(dentry); 722 struct ext4_xattr_ibody_header *header; 723 struct ext4_inode *raw_inode; 724 struct ext4_iloc iloc; 725 void *end; 726 int error; 727 728 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 729 return 0; 730 error = ext4_get_inode_loc(inode, &iloc); 731 if (error) 732 return error; 733 raw_inode = ext4_raw_inode(&iloc); 734 header = IHDR(inode, raw_inode); 735 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 736 error = xattr_check_inode(inode, header, end); 737 if (error) 738 goto cleanup; 739 error = ext4_xattr_list_entries(dentry, IFIRST(header), 740 buffer, buffer_size); 741 742 cleanup: 743 brelse(iloc.bh); 744 return error; 745 } 746 747 /* 748 * Inode operation listxattr() 749 * 750 * d_inode(dentry)->i_rwsem: don't care 751 * 752 * Copy a list of attribute names into the buffer 753 * provided, or compute the buffer size required. 754 * Buffer is NULL to compute the size of the buffer required. 755 * 756 * Returns a negative error number on failure, or the number of bytes 757 * used / required on success. 758 */ 759 ssize_t 760 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 761 { 762 int ret, ret2; 763 764 down_read(&EXT4_I(d_inode(dentry))->xattr_sem); 765 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); 766 if (ret < 0) 767 goto errout; 768 if (buffer) { 769 buffer += ret; 770 buffer_size -= ret; 771 } 772 ret = ext4_xattr_block_list(dentry, buffer, buffer_size); 773 if (ret < 0) 774 goto errout; 775 ret += ret2; 776 errout: 777 up_read(&EXT4_I(d_inode(dentry))->xattr_sem); 778 return ret; 779 } 780 781 /* 782 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is 783 * not set, set it. 784 */ 785 static void ext4_xattr_update_super_block(handle_t *handle, 786 struct super_block *sb) 787 { 788 if (ext4_has_feature_xattr(sb)) 789 return; 790 791 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 792 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { 793 ext4_set_feature_xattr(sb); 794 ext4_handle_dirty_super(handle, sb); 795 } 796 } 797 798 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 799 { 800 struct ext4_iloc iloc = { .bh = NULL }; 801 struct buffer_head *bh = NULL; 802 struct ext4_inode *raw_inode; 803 struct ext4_xattr_ibody_header *header; 804 struct ext4_xattr_entry *entry; 805 qsize_t ea_inode_refs = 0; 806 void *end; 807 int ret; 808 809 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); 810 811 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 812 ret = ext4_get_inode_loc(inode, &iloc); 813 if (ret) 814 goto out; 815 raw_inode = ext4_raw_inode(&iloc); 816 header = IHDR(inode, raw_inode); 817 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 818 ret = xattr_check_inode(inode, header, end); 819 if (ret) 820 goto out; 821 822 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); 823 entry = EXT4_XATTR_NEXT(entry)) 824 if (entry->e_value_inum) 825 ea_inode_refs++; 826 } 827 828 if (EXT4_I(inode)->i_file_acl) { 829 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 830 if (IS_ERR(bh)) { 831 ret = PTR_ERR(bh); 832 bh = NULL; 833 goto out; 834 } 835 836 ret = ext4_xattr_check_block(inode, bh); 837 if (ret) 838 goto out; 839 840 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 841 entry = EXT4_XATTR_NEXT(entry)) 842 if (entry->e_value_inum) 843 ea_inode_refs++; 844 } 845 *usage = ea_inode_refs + 1; 846 ret = 0; 847 out: 848 brelse(iloc.bh); 849 brelse(bh); 850 return ret; 851 } 852 853 static inline size_t round_up_cluster(struct inode *inode, size_t length) 854 { 855 struct super_block *sb = inode->i_sb; 856 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits + 857 inode->i_blkbits); 858 size_t mask = ~(cluster_size - 1); 859 860 return (length + cluster_size - 1) & mask; 861 } 862 863 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len) 864 { 865 int err; 866 867 err = dquot_alloc_inode(inode); 868 if (err) 869 return err; 870 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len)); 871 if (err) 872 dquot_free_inode(inode); 873 return err; 874 } 875 876 static void ext4_xattr_inode_free_quota(struct inode *parent, 877 struct inode *ea_inode, 878 size_t len) 879 { 880 if (ea_inode && 881 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) 882 return; 883 dquot_free_space_nodirty(parent, round_up_cluster(parent, len)); 884 dquot_free_inode(parent); 885 } 886 887 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, 888 struct buffer_head *block_bh, size_t value_len, 889 bool is_create) 890 { 891 int credits; 892 int blocks; 893 894 /* 895 * 1) Owner inode update 896 * 2) Ref count update on old xattr block 897 * 3) new xattr block 898 * 4) block bitmap update for new xattr block 899 * 5) group descriptor for new xattr block 900 * 6) block bitmap update for old xattr block 901 * 7) group descriptor for old block 902 * 903 * 6 & 7 can happen if we have two racing threads T_a and T_b 904 * which are each trying to set an xattr on inodes I_a and I_b 905 * which were both initially sharing an xattr block. 906 */ 907 credits = 7; 908 909 /* Quota updates. */ 910 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb); 911 912 /* 913 * In case of inline data, we may push out the data to a block, 914 * so we need to reserve credits for this eventuality 915 */ 916 if (inode && ext4_has_inline_data(inode)) 917 credits += ext4_writepage_trans_blocks(inode) + 1; 918 919 /* We are done if ea_inode feature is not enabled. */ 920 if (!ext4_has_feature_ea_inode(sb)) 921 return credits; 922 923 /* New ea_inode, inode map, block bitmap, group descriptor. */ 924 credits += 4; 925 926 /* Data blocks. */ 927 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 928 929 /* Indirection block or one level of extent tree. */ 930 blocks += 1; 931 932 /* Block bitmap and group descriptor updates for each block. */ 933 credits += blocks * 2; 934 935 /* Blocks themselves. */ 936 credits += blocks; 937 938 if (!is_create) { 939 /* Dereference ea_inode holding old xattr value. 940 * Old ea_inode, inode map, block bitmap, group descriptor. 941 */ 942 credits += 4; 943 944 /* Data blocks for old ea_inode. */ 945 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits; 946 947 /* Indirection block or one level of extent tree for old 948 * ea_inode. 949 */ 950 blocks += 1; 951 952 /* Block bitmap and group descriptor updates for each block. */ 953 credits += blocks * 2; 954 } 955 956 /* We may need to clone the existing xattr block in which case we need 957 * to increment ref counts for existing ea_inodes referenced by it. 958 */ 959 if (block_bh) { 960 struct ext4_xattr_entry *entry = BFIRST(block_bh); 961 962 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) 963 if (entry->e_value_inum) 964 /* Ref count update on ea_inode. */ 965 credits += 1; 966 } 967 return credits; 968 } 969 970 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode, 971 int ref_change) 972 { 973 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode); 974 struct ext4_iloc iloc; 975 s64 ref_count; 976 u32 hash; 977 int ret; 978 979 inode_lock(ea_inode); 980 981 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc); 982 if (ret) 983 goto out; 984 985 ref_count = ext4_xattr_inode_get_ref(ea_inode); 986 ref_count += ref_change; 987 ext4_xattr_inode_set_ref(ea_inode, ref_count); 988 989 if (ref_change > 0) { 990 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld", 991 ea_inode->i_ino, ref_count); 992 993 if (ref_count == 1) { 994 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u", 995 ea_inode->i_ino, ea_inode->i_nlink); 996 997 set_nlink(ea_inode, 1); 998 ext4_orphan_del(handle, ea_inode); 999 1000 if (ea_inode_cache) { 1001 hash = ext4_xattr_inode_get_hash(ea_inode); 1002 mb_cache_entry_create(ea_inode_cache, 1003 GFP_NOFS, hash, 1004 ea_inode->i_ino, 1005 true /* reusable */); 1006 } 1007 } 1008 } else { 1009 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld", 1010 ea_inode->i_ino, ref_count); 1011 1012 if (ref_count == 0) { 1013 WARN_ONCE(ea_inode->i_nlink != 1, 1014 "EA inode %lu i_nlink=%u", 1015 ea_inode->i_ino, ea_inode->i_nlink); 1016 1017 clear_nlink(ea_inode); 1018 ext4_orphan_add(handle, ea_inode); 1019 1020 if (ea_inode_cache) { 1021 hash = ext4_xattr_inode_get_hash(ea_inode); 1022 mb_cache_entry_delete(ea_inode_cache, hash, 1023 ea_inode->i_ino); 1024 } 1025 } 1026 } 1027 1028 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc); 1029 if (ret) 1030 ext4_warning_inode(ea_inode, 1031 "ext4_mark_iloc_dirty() failed ret=%d", ret); 1032 out: 1033 inode_unlock(ea_inode); 1034 return ret; 1035 } 1036 1037 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode) 1038 { 1039 return ext4_xattr_inode_update_ref(handle, ea_inode, 1); 1040 } 1041 1042 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode) 1043 { 1044 return ext4_xattr_inode_update_ref(handle, ea_inode, -1); 1045 } 1046 1047 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent, 1048 struct ext4_xattr_entry *first) 1049 { 1050 struct inode *ea_inode; 1051 struct ext4_xattr_entry *entry; 1052 struct ext4_xattr_entry *failed_entry; 1053 unsigned int ea_ino; 1054 int err, saved_err; 1055 1056 for (entry = first; !IS_LAST_ENTRY(entry); 1057 entry = EXT4_XATTR_NEXT(entry)) { 1058 if (!entry->e_value_inum) 1059 continue; 1060 ea_ino = le32_to_cpu(entry->e_value_inum); 1061 err = ext4_xattr_inode_iget(parent, ea_ino, 1062 le32_to_cpu(entry->e_hash), 1063 &ea_inode); 1064 if (err) 1065 goto cleanup; 1066 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1067 if (err) { 1068 ext4_warning_inode(ea_inode, "inc ref error %d", err); 1069 iput(ea_inode); 1070 goto cleanup; 1071 } 1072 iput(ea_inode); 1073 } 1074 return 0; 1075 1076 cleanup: 1077 saved_err = err; 1078 failed_entry = entry; 1079 1080 for (entry = first; entry != failed_entry; 1081 entry = EXT4_XATTR_NEXT(entry)) { 1082 if (!entry->e_value_inum) 1083 continue; 1084 ea_ino = le32_to_cpu(entry->e_value_inum); 1085 err = ext4_xattr_inode_iget(parent, ea_ino, 1086 le32_to_cpu(entry->e_hash), 1087 &ea_inode); 1088 if (err) { 1089 ext4_warning(parent->i_sb, 1090 "cleanup ea_ino %u iget error %d", ea_ino, 1091 err); 1092 continue; 1093 } 1094 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1095 if (err) 1096 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", 1097 err); 1098 iput(ea_inode); 1099 } 1100 return saved_err; 1101 } 1102 1103 static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode, 1104 struct buffer_head *bh, bool block_csum, bool dirty) 1105 { 1106 int error; 1107 1108 if (bh && dirty) { 1109 if (block_csum) 1110 ext4_xattr_block_csum_set(inode, bh); 1111 error = ext4_handle_dirty_metadata(handle, NULL, bh); 1112 if (error) { 1113 ext4_warning(inode->i_sb, "Handle metadata (error %d)", 1114 error); 1115 return error; 1116 } 1117 } 1118 return 0; 1119 } 1120 1121 static void 1122 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent, 1123 struct buffer_head *bh, 1124 struct ext4_xattr_entry *first, bool block_csum, 1125 struct ext4_xattr_inode_array **ea_inode_array, 1126 int extra_credits, bool skip_quota) 1127 { 1128 struct inode *ea_inode; 1129 struct ext4_xattr_entry *entry; 1130 bool dirty = false; 1131 unsigned int ea_ino; 1132 int err; 1133 int credits; 1134 1135 /* One credit for dec ref on ea_inode, one for orphan list addition, */ 1136 credits = 2 + extra_credits; 1137 1138 for (entry = first; !IS_LAST_ENTRY(entry); 1139 entry = EXT4_XATTR_NEXT(entry)) { 1140 if (!entry->e_value_inum) 1141 continue; 1142 ea_ino = le32_to_cpu(entry->e_value_inum); 1143 err = ext4_xattr_inode_iget(parent, ea_ino, 1144 le32_to_cpu(entry->e_hash), 1145 &ea_inode); 1146 if (err) 1147 continue; 1148 1149 err = ext4_expand_inode_array(ea_inode_array, ea_inode); 1150 if (err) { 1151 ext4_warning_inode(ea_inode, 1152 "Expand inode array err=%d", err); 1153 iput(ea_inode); 1154 continue; 1155 } 1156 1157 err = ext4_journal_ensure_credits_fn(handle, credits, credits, 1158 ext4_free_metadata_revoke_credits(parent->i_sb, 1), 1159 ext4_xattr_restart_fn(handle, parent, bh, block_csum, 1160 dirty)); 1161 if (err < 0) { 1162 ext4_warning_inode(ea_inode, "Ensure credits err=%d", 1163 err); 1164 continue; 1165 } 1166 if (err > 0) { 1167 err = ext4_journal_get_write_access(handle, bh); 1168 if (err) { 1169 ext4_warning_inode(ea_inode, 1170 "Re-get write access err=%d", 1171 err); 1172 continue; 1173 } 1174 } 1175 1176 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1177 if (err) { 1178 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d", 1179 err); 1180 continue; 1181 } 1182 1183 if (!skip_quota) 1184 ext4_xattr_inode_free_quota(parent, ea_inode, 1185 le32_to_cpu(entry->e_value_size)); 1186 1187 /* 1188 * Forget about ea_inode within the same transaction that 1189 * decrements the ref count. This avoids duplicate decrements in 1190 * case the rest of the work spills over to subsequent 1191 * transactions. 1192 */ 1193 entry->e_value_inum = 0; 1194 entry->e_value_size = 0; 1195 1196 dirty = true; 1197 } 1198 1199 if (dirty) { 1200 /* 1201 * Note that we are deliberately skipping csum calculation for 1202 * the final update because we do not expect any journal 1203 * restarts until xattr block is freed. 1204 */ 1205 1206 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1207 if (err) 1208 ext4_warning_inode(parent, 1209 "handle dirty metadata err=%d", err); 1210 } 1211 } 1212 1213 /* 1214 * Release the xattr block BH: If the reference count is > 1, decrement it; 1215 * otherwise free the block. 1216 */ 1217 static void 1218 ext4_xattr_release_block(handle_t *handle, struct inode *inode, 1219 struct buffer_head *bh, 1220 struct ext4_xattr_inode_array **ea_inode_array, 1221 int extra_credits) 1222 { 1223 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1224 u32 hash, ref; 1225 int error = 0; 1226 1227 BUFFER_TRACE(bh, "get_write_access"); 1228 error = ext4_journal_get_write_access(handle, bh); 1229 if (error) 1230 goto out; 1231 1232 lock_buffer(bh); 1233 hash = le32_to_cpu(BHDR(bh)->h_hash); 1234 ref = le32_to_cpu(BHDR(bh)->h_refcount); 1235 if (ref == 1) { 1236 ea_bdebug(bh, "refcount now=0; freeing"); 1237 /* 1238 * This must happen under buffer lock for 1239 * ext4_xattr_block_set() to reliably detect freed block 1240 */ 1241 if (ea_block_cache) 1242 mb_cache_entry_delete(ea_block_cache, hash, 1243 bh->b_blocknr); 1244 get_bh(bh); 1245 unlock_buffer(bh); 1246 1247 if (ext4_has_feature_ea_inode(inode->i_sb)) 1248 ext4_xattr_inode_dec_ref_all(handle, inode, bh, 1249 BFIRST(bh), 1250 true /* block_csum */, 1251 ea_inode_array, 1252 extra_credits, 1253 true /* skip_quota */); 1254 ext4_free_blocks(handle, inode, bh, 0, 1, 1255 EXT4_FREE_BLOCKS_METADATA | 1256 EXT4_FREE_BLOCKS_FORGET); 1257 } else { 1258 ref--; 1259 BHDR(bh)->h_refcount = cpu_to_le32(ref); 1260 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) { 1261 struct mb_cache_entry *ce; 1262 1263 if (ea_block_cache) { 1264 ce = mb_cache_entry_get(ea_block_cache, hash, 1265 bh->b_blocknr); 1266 if (ce) { 1267 ce->e_reusable = 1; 1268 mb_cache_entry_put(ea_block_cache, ce); 1269 } 1270 } 1271 } 1272 1273 ext4_xattr_block_csum_set(inode, bh); 1274 /* 1275 * Beware of this ugliness: Releasing of xattr block references 1276 * from different inodes can race and so we have to protect 1277 * from a race where someone else frees the block (and releases 1278 * its journal_head) before we are done dirtying the buffer. In 1279 * nojournal mode this race is harmless and we actually cannot 1280 * call ext4_handle_dirty_metadata() with locked buffer as 1281 * that function can call sync_dirty_buffer() so for that case 1282 * we handle the dirtying after unlocking the buffer. 1283 */ 1284 if (ext4_handle_valid(handle)) 1285 error = ext4_handle_dirty_metadata(handle, inode, bh); 1286 unlock_buffer(bh); 1287 if (!ext4_handle_valid(handle)) 1288 error = ext4_handle_dirty_metadata(handle, inode, bh); 1289 if (IS_SYNC(inode)) 1290 ext4_handle_sync(handle); 1291 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); 1292 ea_bdebug(bh, "refcount now=%d; releasing", 1293 le32_to_cpu(BHDR(bh)->h_refcount)); 1294 } 1295 out: 1296 ext4_std_error(inode->i_sb, error); 1297 return; 1298 } 1299 1300 /* 1301 * Find the available free space for EAs. This also returns the total number of 1302 * bytes used by EA entries. 1303 */ 1304 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, 1305 size_t *min_offs, void *base, int *total) 1306 { 1307 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1308 if (!last->e_value_inum && last->e_value_size) { 1309 size_t offs = le16_to_cpu(last->e_value_offs); 1310 if (offs < *min_offs) 1311 *min_offs = offs; 1312 } 1313 if (total) 1314 *total += EXT4_XATTR_LEN(last->e_name_len); 1315 } 1316 return (*min_offs - ((void *)last - base) - sizeof(__u32)); 1317 } 1318 1319 /* 1320 * Write the value of the EA in an inode. 1321 */ 1322 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode, 1323 const void *buf, int bufsize) 1324 { 1325 struct buffer_head *bh = NULL; 1326 unsigned long block = 0; 1327 int blocksize = ea_inode->i_sb->s_blocksize; 1328 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits; 1329 int csize, wsize = 0; 1330 int ret = 0; 1331 int retries = 0; 1332 1333 retry: 1334 while (ret >= 0 && ret < max_blocks) { 1335 struct ext4_map_blocks map; 1336 map.m_lblk = block += ret; 1337 map.m_len = max_blocks -= ret; 1338 1339 ret = ext4_map_blocks(handle, ea_inode, &map, 1340 EXT4_GET_BLOCKS_CREATE); 1341 if (ret <= 0) { 1342 ext4_mark_inode_dirty(handle, ea_inode); 1343 if (ret == -ENOSPC && 1344 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) { 1345 ret = 0; 1346 goto retry; 1347 } 1348 break; 1349 } 1350 } 1351 1352 if (ret < 0) 1353 return ret; 1354 1355 block = 0; 1356 while (wsize < bufsize) { 1357 if (bh != NULL) 1358 brelse(bh); 1359 csize = (bufsize - wsize) > blocksize ? blocksize : 1360 bufsize - wsize; 1361 bh = ext4_getblk(handle, ea_inode, block, 0); 1362 if (IS_ERR(bh)) 1363 return PTR_ERR(bh); 1364 if (!bh) { 1365 WARN_ON_ONCE(1); 1366 EXT4_ERROR_INODE(ea_inode, 1367 "ext4_getblk() return bh = NULL"); 1368 return -EFSCORRUPTED; 1369 } 1370 ret = ext4_journal_get_write_access(handle, bh); 1371 if (ret) 1372 goto out; 1373 1374 memcpy(bh->b_data, buf, csize); 1375 set_buffer_uptodate(bh); 1376 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1377 1378 buf += csize; 1379 wsize += csize; 1380 block += 1; 1381 } 1382 1383 inode_lock(ea_inode); 1384 i_size_write(ea_inode, wsize); 1385 ext4_update_i_disksize(ea_inode, wsize); 1386 inode_unlock(ea_inode); 1387 1388 ext4_mark_inode_dirty(handle, ea_inode); 1389 1390 out: 1391 brelse(bh); 1392 1393 return ret; 1394 } 1395 1396 /* 1397 * Create an inode to store the value of a large EA. 1398 */ 1399 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1400 struct inode *inode, u32 hash) 1401 { 1402 struct inode *ea_inode = NULL; 1403 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1404 int err; 1405 1406 /* 1407 * Let the next inode be the goal, so we try and allocate the EA inode 1408 * in the same group, or nearby one. 1409 */ 1410 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1411 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1412 EXT4_EA_INODE_FL); 1413 if (!IS_ERR(ea_inode)) { 1414 ea_inode->i_op = &ext4_file_inode_operations; 1415 ea_inode->i_fop = &ext4_file_operations; 1416 ext4_set_aops(ea_inode); 1417 ext4_xattr_inode_set_class(ea_inode); 1418 unlock_new_inode(ea_inode); 1419 ext4_xattr_inode_set_ref(ea_inode, 1); 1420 ext4_xattr_inode_set_hash(ea_inode, hash); 1421 err = ext4_mark_inode_dirty(handle, ea_inode); 1422 if (!err) 1423 err = ext4_inode_attach_jinode(ea_inode); 1424 if (err) { 1425 iput(ea_inode); 1426 return ERR_PTR(err); 1427 } 1428 1429 /* 1430 * Xattr inodes are shared therefore quota charging is performed 1431 * at a higher level. 1432 */ 1433 dquot_free_inode(ea_inode); 1434 dquot_drop(ea_inode); 1435 inode_lock(ea_inode); 1436 ea_inode->i_flags |= S_NOQUOTA; 1437 inode_unlock(ea_inode); 1438 } 1439 1440 return ea_inode; 1441 } 1442 1443 static struct inode * 1444 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1445 size_t value_len, u32 hash) 1446 { 1447 struct inode *ea_inode; 1448 struct mb_cache_entry *ce; 1449 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1450 void *ea_data; 1451 1452 if (!ea_inode_cache) 1453 return NULL; 1454 1455 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1456 if (!ce) 1457 return NULL; 1458 1459 ea_data = kvmalloc(value_len, GFP_KERNEL); 1460 if (!ea_data) { 1461 mb_cache_entry_put(ea_inode_cache, ce); 1462 return NULL; 1463 } 1464 1465 while (ce) { 1466 ea_inode = ext4_iget(inode->i_sb, ce->e_value, 1467 EXT4_IGET_NORMAL); 1468 if (!IS_ERR(ea_inode) && 1469 !is_bad_inode(ea_inode) && 1470 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1471 i_size_read(ea_inode) == value_len && 1472 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1473 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1474 value_len) && 1475 !memcmp(value, ea_data, value_len)) { 1476 mb_cache_entry_touch(ea_inode_cache, ce); 1477 mb_cache_entry_put(ea_inode_cache, ce); 1478 kvfree(ea_data); 1479 return ea_inode; 1480 } 1481 1482 if (!IS_ERR(ea_inode)) 1483 iput(ea_inode); 1484 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1485 } 1486 kvfree(ea_data); 1487 return NULL; 1488 } 1489 1490 /* 1491 * Add value of the EA in an inode. 1492 */ 1493 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1494 const void *value, size_t value_len, 1495 struct inode **ret_inode) 1496 { 1497 struct inode *ea_inode; 1498 u32 hash; 1499 int err; 1500 1501 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1502 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1503 if (ea_inode) { 1504 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1505 if (err) { 1506 iput(ea_inode); 1507 return err; 1508 } 1509 1510 *ret_inode = ea_inode; 1511 return 0; 1512 } 1513 1514 /* Create an inode for the EA value */ 1515 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1516 if (IS_ERR(ea_inode)) 1517 return PTR_ERR(ea_inode); 1518 1519 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1520 if (err) { 1521 ext4_xattr_inode_dec_ref(handle, ea_inode); 1522 iput(ea_inode); 1523 return err; 1524 } 1525 1526 if (EA_INODE_CACHE(inode)) 1527 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1528 ea_inode->i_ino, true /* reusable */); 1529 1530 *ret_inode = ea_inode; 1531 return 0; 1532 } 1533 1534 /* 1535 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1536 * feature is enabled. 1537 */ 1538 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1539 1540 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1541 struct ext4_xattr_search *s, 1542 handle_t *handle, struct inode *inode, 1543 bool is_block) 1544 { 1545 struct ext4_xattr_entry *last, *next; 1546 struct ext4_xattr_entry *here = s->here; 1547 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1548 int in_inode = i->in_inode; 1549 struct inode *old_ea_inode = NULL; 1550 struct inode *new_ea_inode = NULL; 1551 size_t old_size, new_size; 1552 int ret; 1553 1554 /* Space used by old and new values. */ 1555 old_size = (!s->not_found && !here->e_value_inum) ? 1556 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1557 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1558 1559 /* 1560 * Optimization for the simple case when old and new values have the 1561 * same padded sizes. Not applicable if external inodes are involved. 1562 */ 1563 if (new_size && new_size == old_size) { 1564 size_t offs = le16_to_cpu(here->e_value_offs); 1565 void *val = s->base + offs; 1566 1567 here->e_value_size = cpu_to_le32(i->value_len); 1568 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1569 memset(val, 0, new_size); 1570 } else { 1571 memcpy(val, i->value, i->value_len); 1572 /* Clear padding bytes. */ 1573 memset(val + i->value_len, 0, new_size - i->value_len); 1574 } 1575 goto update_hash; 1576 } 1577 1578 /* Compute min_offs and last. */ 1579 last = s->first; 1580 for (; !IS_LAST_ENTRY(last); last = next) { 1581 next = EXT4_XATTR_NEXT(last); 1582 if ((void *)next >= s->end) { 1583 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 1584 ret = -EFSCORRUPTED; 1585 goto out; 1586 } 1587 if (!last->e_value_inum && last->e_value_size) { 1588 size_t offs = le16_to_cpu(last->e_value_offs); 1589 if (offs < min_offs) 1590 min_offs = offs; 1591 } 1592 } 1593 1594 /* Check whether we have enough space. */ 1595 if (i->value) { 1596 size_t free; 1597 1598 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1599 if (!s->not_found) 1600 free += EXT4_XATTR_LEN(name_len) + old_size; 1601 1602 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1603 ret = -ENOSPC; 1604 goto out; 1605 } 1606 1607 /* 1608 * If storing the value in an external inode is an option, 1609 * reserve space for xattr entries/names in the external 1610 * attribute block so that a long value does not occupy the 1611 * whole space and prevent futher entries being added. 1612 */ 1613 if (ext4_has_feature_ea_inode(inode->i_sb) && 1614 new_size && is_block && 1615 (min_offs + old_size - new_size) < 1616 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1617 ret = -ENOSPC; 1618 goto out; 1619 } 1620 } 1621 1622 /* 1623 * Getting access to old and new ea inodes is subject to failures. 1624 * Finish that work before doing any modifications to the xattr data. 1625 */ 1626 if (!s->not_found && here->e_value_inum) { 1627 ret = ext4_xattr_inode_iget(inode, 1628 le32_to_cpu(here->e_value_inum), 1629 le32_to_cpu(here->e_hash), 1630 &old_ea_inode); 1631 if (ret) { 1632 old_ea_inode = NULL; 1633 goto out; 1634 } 1635 } 1636 if (i->value && in_inode) { 1637 WARN_ON_ONCE(!i->value_len); 1638 1639 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1640 if (ret) 1641 goto out; 1642 1643 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1644 i->value_len, 1645 &new_ea_inode); 1646 if (ret) { 1647 new_ea_inode = NULL; 1648 ext4_xattr_inode_free_quota(inode, NULL, i->value_len); 1649 goto out; 1650 } 1651 } 1652 1653 if (old_ea_inode) { 1654 /* We are ready to release ref count on the old_ea_inode. */ 1655 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1656 if (ret) { 1657 /* Release newly required ref count on new_ea_inode. */ 1658 if (new_ea_inode) { 1659 int err; 1660 1661 err = ext4_xattr_inode_dec_ref(handle, 1662 new_ea_inode); 1663 if (err) 1664 ext4_warning_inode(new_ea_inode, 1665 "dec ref new_ea_inode err=%d", 1666 err); 1667 ext4_xattr_inode_free_quota(inode, new_ea_inode, 1668 i->value_len); 1669 } 1670 goto out; 1671 } 1672 1673 ext4_xattr_inode_free_quota(inode, old_ea_inode, 1674 le32_to_cpu(here->e_value_size)); 1675 } 1676 1677 /* No failures allowed past this point. */ 1678 1679 if (!s->not_found && here->e_value_size && !here->e_value_inum) { 1680 /* Remove the old value. */ 1681 void *first_val = s->base + min_offs; 1682 size_t offs = le16_to_cpu(here->e_value_offs); 1683 void *val = s->base + offs; 1684 1685 memmove(first_val + old_size, first_val, val - first_val); 1686 memset(first_val, 0, old_size); 1687 min_offs += old_size; 1688 1689 /* Adjust all value offsets. */ 1690 last = s->first; 1691 while (!IS_LAST_ENTRY(last)) { 1692 size_t o = le16_to_cpu(last->e_value_offs); 1693 1694 if (!last->e_value_inum && 1695 last->e_value_size && o < offs) 1696 last->e_value_offs = cpu_to_le16(o + old_size); 1697 last = EXT4_XATTR_NEXT(last); 1698 } 1699 } 1700 1701 if (!i->value) { 1702 /* Remove old name. */ 1703 size_t size = EXT4_XATTR_LEN(name_len); 1704 1705 last = ENTRY((void *)last - size); 1706 memmove(here, (void *)here + size, 1707 (void *)last - (void *)here + sizeof(__u32)); 1708 memset(last, 0, size); 1709 } else if (s->not_found) { 1710 /* Insert new name. */ 1711 size_t size = EXT4_XATTR_LEN(name_len); 1712 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1713 1714 memmove((void *)here + size, here, rest); 1715 memset(here, 0, size); 1716 here->e_name_index = i->name_index; 1717 here->e_name_len = name_len; 1718 memcpy(here->e_name, i->name, name_len); 1719 } else { 1720 /* This is an update, reset value info. */ 1721 here->e_value_inum = 0; 1722 here->e_value_offs = 0; 1723 here->e_value_size = 0; 1724 } 1725 1726 if (i->value) { 1727 /* Insert new value. */ 1728 if (in_inode) { 1729 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1730 } else if (i->value_len) { 1731 void *val = s->base + min_offs - new_size; 1732 1733 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1734 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1735 memset(val, 0, new_size); 1736 } else { 1737 memcpy(val, i->value, i->value_len); 1738 /* Clear padding bytes. */ 1739 memset(val + i->value_len, 0, 1740 new_size - i->value_len); 1741 } 1742 } 1743 here->e_value_size = cpu_to_le32(i->value_len); 1744 } 1745 1746 update_hash: 1747 if (i->value) { 1748 __le32 hash = 0; 1749 1750 /* Entry hash calculation. */ 1751 if (in_inode) { 1752 __le32 crc32c_hash; 1753 1754 /* 1755 * Feed crc32c hash instead of the raw value for entry 1756 * hash calculation. This is to avoid walking 1757 * potentially long value buffer again. 1758 */ 1759 crc32c_hash = cpu_to_le32( 1760 ext4_xattr_inode_get_hash(new_ea_inode)); 1761 hash = ext4_xattr_hash_entry(here->e_name, 1762 here->e_name_len, 1763 &crc32c_hash, 1); 1764 } else if (is_block) { 1765 __le32 *value = s->base + le16_to_cpu( 1766 here->e_value_offs); 1767 1768 hash = ext4_xattr_hash_entry(here->e_name, 1769 here->e_name_len, value, 1770 new_size >> 2); 1771 } 1772 here->e_hash = hash; 1773 } 1774 1775 if (is_block) 1776 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1777 1778 ret = 0; 1779 out: 1780 iput(old_ea_inode); 1781 iput(new_ea_inode); 1782 return ret; 1783 } 1784 1785 struct ext4_xattr_block_find { 1786 struct ext4_xattr_search s; 1787 struct buffer_head *bh; 1788 }; 1789 1790 static int 1791 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1792 struct ext4_xattr_block_find *bs) 1793 { 1794 struct super_block *sb = inode->i_sb; 1795 int error; 1796 1797 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1798 i->name_index, i->name, i->value, (long)i->value_len); 1799 1800 if (EXT4_I(inode)->i_file_acl) { 1801 /* The inode already has an extended attribute block. */ 1802 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 1803 if (IS_ERR(bs->bh)) 1804 return PTR_ERR(bs->bh); 1805 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1806 atomic_read(&(bs->bh->b_count)), 1807 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1808 error = ext4_xattr_check_block(inode, bs->bh); 1809 if (error) 1810 return error; 1811 /* Find the named attribute. */ 1812 bs->s.base = BHDR(bs->bh); 1813 bs->s.first = BFIRST(bs->bh); 1814 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1815 bs->s.here = bs->s.first; 1816 error = xattr_find_entry(inode, &bs->s.here, bs->s.end, 1817 i->name_index, i->name, 1); 1818 if (error && error != -ENODATA) 1819 return error; 1820 bs->s.not_found = error; 1821 } 1822 return 0; 1823 } 1824 1825 static int 1826 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1827 struct ext4_xattr_info *i, 1828 struct ext4_xattr_block_find *bs) 1829 { 1830 struct super_block *sb = inode->i_sb; 1831 struct buffer_head *new_bh = NULL; 1832 struct ext4_xattr_search s_copy = bs->s; 1833 struct ext4_xattr_search *s = &s_copy; 1834 struct mb_cache_entry *ce = NULL; 1835 int error = 0; 1836 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1837 struct inode *ea_inode = NULL, *tmp_inode; 1838 size_t old_ea_inode_quota = 0; 1839 unsigned int ea_ino; 1840 1841 1842 #define header(x) ((struct ext4_xattr_header *)(x)) 1843 1844 if (s->base) { 1845 BUFFER_TRACE(bs->bh, "get_write_access"); 1846 error = ext4_journal_get_write_access(handle, bs->bh); 1847 if (error) 1848 goto cleanup; 1849 lock_buffer(bs->bh); 1850 1851 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1852 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1853 1854 /* 1855 * This must happen under buffer lock for 1856 * ext4_xattr_block_set() to reliably detect modified 1857 * block 1858 */ 1859 if (ea_block_cache) 1860 mb_cache_entry_delete(ea_block_cache, hash, 1861 bs->bh->b_blocknr); 1862 ea_bdebug(bs->bh, "modifying in-place"); 1863 error = ext4_xattr_set_entry(i, s, handle, inode, 1864 true /* is_block */); 1865 ext4_xattr_block_csum_set(inode, bs->bh); 1866 unlock_buffer(bs->bh); 1867 if (error == -EFSCORRUPTED) 1868 goto bad_block; 1869 if (!error) 1870 error = ext4_handle_dirty_metadata(handle, 1871 inode, 1872 bs->bh); 1873 if (error) 1874 goto cleanup; 1875 goto inserted; 1876 } else { 1877 int offset = (char *)s->here - bs->bh->b_data; 1878 1879 unlock_buffer(bs->bh); 1880 ea_bdebug(bs->bh, "cloning"); 1881 s->base = kmalloc(bs->bh->b_size, GFP_NOFS); 1882 error = -ENOMEM; 1883 if (s->base == NULL) 1884 goto cleanup; 1885 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); 1886 s->first = ENTRY(header(s->base)+1); 1887 header(s->base)->h_refcount = cpu_to_le32(1); 1888 s->here = ENTRY(s->base + offset); 1889 s->end = s->base + bs->bh->b_size; 1890 1891 /* 1892 * If existing entry points to an xattr inode, we need 1893 * to prevent ext4_xattr_set_entry() from decrementing 1894 * ref count on it because the reference belongs to the 1895 * original block. In this case, make the entry look 1896 * like it has an empty value. 1897 */ 1898 if (!s->not_found && s->here->e_value_inum) { 1899 ea_ino = le32_to_cpu(s->here->e_value_inum); 1900 error = ext4_xattr_inode_iget(inode, ea_ino, 1901 le32_to_cpu(s->here->e_hash), 1902 &tmp_inode); 1903 if (error) 1904 goto cleanup; 1905 1906 if (!ext4_test_inode_state(tmp_inode, 1907 EXT4_STATE_LUSTRE_EA_INODE)) { 1908 /* 1909 * Defer quota free call for previous 1910 * inode until success is guaranteed. 1911 */ 1912 old_ea_inode_quota = le32_to_cpu( 1913 s->here->e_value_size); 1914 } 1915 iput(tmp_inode); 1916 1917 s->here->e_value_inum = 0; 1918 s->here->e_value_size = 0; 1919 } 1920 } 1921 } else { 1922 /* Allocate a buffer where we construct the new block. */ 1923 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1924 /* assert(header == s->base) */ 1925 error = -ENOMEM; 1926 if (s->base == NULL) 1927 goto cleanup; 1928 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1929 header(s->base)->h_blocks = cpu_to_le32(1); 1930 header(s->base)->h_refcount = cpu_to_le32(1); 1931 s->first = ENTRY(header(s->base)+1); 1932 s->here = ENTRY(header(s->base)+1); 1933 s->end = s->base + sb->s_blocksize; 1934 } 1935 1936 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1937 if (error == -EFSCORRUPTED) 1938 goto bad_block; 1939 if (error) 1940 goto cleanup; 1941 1942 if (i->value && s->here->e_value_inum) { 1943 /* 1944 * A ref count on ea_inode has been taken as part of the call to 1945 * ext4_xattr_set_entry() above. We would like to drop this 1946 * extra ref but we have to wait until the xattr block is 1947 * initialized and has its own ref count on the ea_inode. 1948 */ 1949 ea_ino = le32_to_cpu(s->here->e_value_inum); 1950 error = ext4_xattr_inode_iget(inode, ea_ino, 1951 le32_to_cpu(s->here->e_hash), 1952 &ea_inode); 1953 if (error) { 1954 ea_inode = NULL; 1955 goto cleanup; 1956 } 1957 } 1958 1959 inserted: 1960 if (!IS_LAST_ENTRY(s->first)) { 1961 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 1962 &ce); 1963 if (new_bh) { 1964 /* We found an identical block in the cache. */ 1965 if (new_bh == bs->bh) 1966 ea_bdebug(new_bh, "keeping"); 1967 else { 1968 u32 ref; 1969 1970 WARN_ON_ONCE(dquot_initialize_needed(inode)); 1971 1972 /* The old block is released after updating 1973 the inode. */ 1974 error = dquot_alloc_block(inode, 1975 EXT4_C2B(EXT4_SB(sb), 1)); 1976 if (error) 1977 goto cleanup; 1978 BUFFER_TRACE(new_bh, "get_write_access"); 1979 error = ext4_journal_get_write_access(handle, 1980 new_bh); 1981 if (error) 1982 goto cleanup_dquot; 1983 lock_buffer(new_bh); 1984 /* 1985 * We have to be careful about races with 1986 * freeing, rehashing or adding references to 1987 * xattr block. Once we hold buffer lock xattr 1988 * block's state is stable so we can check 1989 * whether the block got freed / rehashed or 1990 * not. Since we unhash mbcache entry under 1991 * buffer lock when freeing / rehashing xattr 1992 * block, checking whether entry is still 1993 * hashed is reliable. Same rules hold for 1994 * e_reusable handling. 1995 */ 1996 if (hlist_bl_unhashed(&ce->e_hash_list) || 1997 !ce->e_reusable) { 1998 /* 1999 * Undo everything and check mbcache 2000 * again. 2001 */ 2002 unlock_buffer(new_bh); 2003 dquot_free_block(inode, 2004 EXT4_C2B(EXT4_SB(sb), 2005 1)); 2006 brelse(new_bh); 2007 mb_cache_entry_put(ea_block_cache, ce); 2008 ce = NULL; 2009 new_bh = NULL; 2010 goto inserted; 2011 } 2012 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 2013 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 2014 if (ref >= EXT4_XATTR_REFCOUNT_MAX) 2015 ce->e_reusable = 0; 2016 ea_bdebug(new_bh, "reusing; refcount now=%d", 2017 ref); 2018 ext4_xattr_block_csum_set(inode, new_bh); 2019 unlock_buffer(new_bh); 2020 error = ext4_handle_dirty_metadata(handle, 2021 inode, 2022 new_bh); 2023 if (error) 2024 goto cleanup_dquot; 2025 } 2026 mb_cache_entry_touch(ea_block_cache, ce); 2027 mb_cache_entry_put(ea_block_cache, ce); 2028 ce = NULL; 2029 } else if (bs->bh && s->base == bs->bh->b_data) { 2030 /* We were modifying this block in-place. */ 2031 ea_bdebug(bs->bh, "keeping this block"); 2032 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 2033 new_bh = bs->bh; 2034 get_bh(new_bh); 2035 } else { 2036 /* We need to allocate a new block */ 2037 ext4_fsblk_t goal, block; 2038 2039 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2040 2041 goal = ext4_group_first_block_no(sb, 2042 EXT4_I(inode)->i_block_group); 2043 2044 /* non-extent files can't have physical blocks past 2^32 */ 2045 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2046 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; 2047 2048 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2049 NULL, &error); 2050 if (error) 2051 goto cleanup; 2052 2053 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2054 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); 2055 2056 ea_idebug(inode, "creating block %llu", 2057 (unsigned long long)block); 2058 2059 new_bh = sb_getblk(sb, block); 2060 if (unlikely(!new_bh)) { 2061 error = -ENOMEM; 2062 getblk_failed: 2063 ext4_free_blocks(handle, inode, NULL, block, 1, 2064 EXT4_FREE_BLOCKS_METADATA); 2065 goto cleanup; 2066 } 2067 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2068 ENTRY(header(s->base)+1)); 2069 if (error) 2070 goto getblk_failed; 2071 if (ea_inode) { 2072 /* Drop the extra ref on ea_inode. */ 2073 error = ext4_xattr_inode_dec_ref(handle, 2074 ea_inode); 2075 if (error) 2076 ext4_warning_inode(ea_inode, 2077 "dec ref error=%d", 2078 error); 2079 iput(ea_inode); 2080 ea_inode = NULL; 2081 } 2082 2083 lock_buffer(new_bh); 2084 error = ext4_journal_get_create_access(handle, new_bh); 2085 if (error) { 2086 unlock_buffer(new_bh); 2087 error = -EIO; 2088 goto getblk_failed; 2089 } 2090 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2091 ext4_xattr_block_csum_set(inode, new_bh); 2092 set_buffer_uptodate(new_bh); 2093 unlock_buffer(new_bh); 2094 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2095 error = ext4_handle_dirty_metadata(handle, inode, 2096 new_bh); 2097 if (error) 2098 goto cleanup; 2099 } 2100 } 2101 2102 if (old_ea_inode_quota) 2103 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota); 2104 2105 /* Update the inode. */ 2106 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2107 2108 /* Drop the previous xattr block. */ 2109 if (bs->bh && bs->bh != new_bh) { 2110 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2111 2112 ext4_xattr_release_block(handle, inode, bs->bh, 2113 &ea_inode_array, 2114 0 /* extra_credits */); 2115 ext4_xattr_inode_array_free(ea_inode_array); 2116 } 2117 error = 0; 2118 2119 cleanup: 2120 if (ea_inode) { 2121 int error2; 2122 2123 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2124 if (error2) 2125 ext4_warning_inode(ea_inode, "dec ref error=%d", 2126 error2); 2127 2128 /* If there was an error, revert the quota charge. */ 2129 if (error) 2130 ext4_xattr_inode_free_quota(inode, ea_inode, 2131 i_size_read(ea_inode)); 2132 iput(ea_inode); 2133 } 2134 if (ce) 2135 mb_cache_entry_put(ea_block_cache, ce); 2136 brelse(new_bh); 2137 if (!(bs->bh && s->base == bs->bh->b_data)) 2138 kfree(s->base); 2139 2140 return error; 2141 2142 cleanup_dquot: 2143 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2144 goto cleanup; 2145 2146 bad_block: 2147 EXT4_ERROR_INODE(inode, "bad block %llu", 2148 EXT4_I(inode)->i_file_acl); 2149 goto cleanup; 2150 2151 #undef header 2152 } 2153 2154 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2155 struct ext4_xattr_ibody_find *is) 2156 { 2157 struct ext4_xattr_ibody_header *header; 2158 struct ext4_inode *raw_inode; 2159 int error; 2160 2161 if (EXT4_I(inode)->i_extra_isize == 0) 2162 return 0; 2163 raw_inode = ext4_raw_inode(&is->iloc); 2164 header = IHDR(inode, raw_inode); 2165 is->s.base = is->s.first = IFIRST(header); 2166 is->s.here = is->s.first; 2167 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2168 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2169 error = xattr_check_inode(inode, header, is->s.end); 2170 if (error) 2171 return error; 2172 /* Find the named attribute. */ 2173 error = xattr_find_entry(inode, &is->s.here, is->s.end, 2174 i->name_index, i->name, 0); 2175 if (error && error != -ENODATA) 2176 return error; 2177 is->s.not_found = error; 2178 } 2179 return 0; 2180 } 2181 2182 int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 2183 struct ext4_xattr_info *i, 2184 struct ext4_xattr_ibody_find *is) 2185 { 2186 struct ext4_xattr_ibody_header *header; 2187 struct ext4_xattr_search *s = &is->s; 2188 int error; 2189 2190 if (EXT4_I(inode)->i_extra_isize == 0) 2191 return -ENOSPC; 2192 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2193 if (error) 2194 return error; 2195 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2196 if (!IS_LAST_ENTRY(s->first)) { 2197 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2198 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2199 } else { 2200 header->h_magic = cpu_to_le32(0); 2201 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2202 } 2203 return 0; 2204 } 2205 2206 static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2207 struct ext4_xattr_info *i, 2208 struct ext4_xattr_ibody_find *is) 2209 { 2210 struct ext4_xattr_ibody_header *header; 2211 struct ext4_xattr_search *s = &is->s; 2212 int error; 2213 2214 if (EXT4_I(inode)->i_extra_isize == 0) 2215 return -ENOSPC; 2216 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2217 if (error) 2218 return error; 2219 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2220 if (!IS_LAST_ENTRY(s->first)) { 2221 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2222 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2223 } else { 2224 header->h_magic = cpu_to_le32(0); 2225 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2226 } 2227 return 0; 2228 } 2229 2230 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2231 struct ext4_xattr_info *i) 2232 { 2233 void *value; 2234 2235 /* When e_value_inum is set the value is stored externally. */ 2236 if (s->here->e_value_inum) 2237 return 0; 2238 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2239 return 0; 2240 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2241 return !memcmp(value, i->value, i->value_len); 2242 } 2243 2244 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2245 { 2246 struct buffer_head *bh; 2247 int error; 2248 2249 if (!EXT4_I(inode)->i_file_acl) 2250 return NULL; 2251 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2252 if (IS_ERR(bh)) 2253 return bh; 2254 error = ext4_xattr_check_block(inode, bh); 2255 if (error) { 2256 brelse(bh); 2257 return ERR_PTR(error); 2258 } 2259 return bh; 2260 } 2261 2262 /* 2263 * ext4_xattr_set_handle() 2264 * 2265 * Create, replace or remove an extended attribute for this inode. Value 2266 * is NULL to remove an existing extended attribute, and non-NULL to 2267 * either replace an existing extended attribute, or create a new extended 2268 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2269 * specify that an extended attribute must exist and must not exist 2270 * previous to the call, respectively. 2271 * 2272 * Returns 0, or a negative error number on failure. 2273 */ 2274 int 2275 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2276 const char *name, const void *value, size_t value_len, 2277 int flags) 2278 { 2279 struct ext4_xattr_info i = { 2280 .name_index = name_index, 2281 .name = name, 2282 .value = value, 2283 .value_len = value_len, 2284 .in_inode = 0, 2285 }; 2286 struct ext4_xattr_ibody_find is = { 2287 .s = { .not_found = -ENODATA, }, 2288 }; 2289 struct ext4_xattr_block_find bs = { 2290 .s = { .not_found = -ENODATA, }, 2291 }; 2292 int no_expand; 2293 int error; 2294 2295 if (!name) 2296 return -EINVAL; 2297 if (strlen(name) > 255) 2298 return -ERANGE; 2299 2300 ext4_write_lock_xattr(inode, &no_expand); 2301 2302 /* Check journal credits under write lock. */ 2303 if (ext4_handle_valid(handle)) { 2304 struct buffer_head *bh; 2305 int credits; 2306 2307 bh = ext4_xattr_get_block(inode); 2308 if (IS_ERR(bh)) { 2309 error = PTR_ERR(bh); 2310 goto cleanup; 2311 } 2312 2313 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2314 value_len, 2315 flags & XATTR_CREATE); 2316 brelse(bh); 2317 2318 if (jbd2_handle_buffer_credits(handle) < credits) { 2319 error = -ENOSPC; 2320 goto cleanup; 2321 } 2322 } 2323 2324 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2325 if (error) 2326 goto cleanup; 2327 2328 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2329 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2330 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2331 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2332 } 2333 2334 error = ext4_xattr_ibody_find(inode, &i, &is); 2335 if (error) 2336 goto cleanup; 2337 if (is.s.not_found) 2338 error = ext4_xattr_block_find(inode, &i, &bs); 2339 if (error) 2340 goto cleanup; 2341 if (is.s.not_found && bs.s.not_found) { 2342 error = -ENODATA; 2343 if (flags & XATTR_REPLACE) 2344 goto cleanup; 2345 error = 0; 2346 if (!value) 2347 goto cleanup; 2348 } else { 2349 error = -EEXIST; 2350 if (flags & XATTR_CREATE) 2351 goto cleanup; 2352 } 2353 2354 if (!value) { 2355 if (!is.s.not_found) 2356 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2357 else if (!bs.s.not_found) 2358 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2359 } else { 2360 error = 0; 2361 /* Xattr value did not change? Save us some work and bail out */ 2362 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2363 goto cleanup; 2364 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2365 goto cleanup; 2366 2367 if (ext4_has_feature_ea_inode(inode->i_sb) && 2368 (EXT4_XATTR_SIZE(i.value_len) > 2369 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2370 i.in_inode = 1; 2371 retry_inode: 2372 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2373 if (!error && !bs.s.not_found) { 2374 i.value = NULL; 2375 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2376 } else if (error == -ENOSPC) { 2377 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2378 brelse(bs.bh); 2379 bs.bh = NULL; 2380 error = ext4_xattr_block_find(inode, &i, &bs); 2381 if (error) 2382 goto cleanup; 2383 } 2384 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2385 if (!error && !is.s.not_found) { 2386 i.value = NULL; 2387 error = ext4_xattr_ibody_set(handle, inode, &i, 2388 &is); 2389 } else if (error == -ENOSPC) { 2390 /* 2391 * Xattr does not fit in the block, store at 2392 * external inode if possible. 2393 */ 2394 if (ext4_has_feature_ea_inode(inode->i_sb) && 2395 !i.in_inode) { 2396 i.in_inode = 1; 2397 goto retry_inode; 2398 } 2399 } 2400 } 2401 } 2402 if (!error) { 2403 ext4_xattr_update_super_block(handle, inode->i_sb); 2404 inode->i_ctime = current_time(inode); 2405 if (!value) 2406 no_expand = 0; 2407 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2408 /* 2409 * The bh is consumed by ext4_mark_iloc_dirty, even with 2410 * error != 0. 2411 */ 2412 is.iloc.bh = NULL; 2413 if (IS_SYNC(inode)) 2414 ext4_handle_sync(handle); 2415 } 2416 2417 cleanup: 2418 brelse(is.iloc.bh); 2419 brelse(bs.bh); 2420 ext4_write_unlock_xattr(inode, &no_expand); 2421 return error; 2422 } 2423 2424 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2425 bool is_create, int *credits) 2426 { 2427 struct buffer_head *bh; 2428 int err; 2429 2430 *credits = 0; 2431 2432 if (!EXT4_SB(inode->i_sb)->s_journal) 2433 return 0; 2434 2435 down_read(&EXT4_I(inode)->xattr_sem); 2436 2437 bh = ext4_xattr_get_block(inode); 2438 if (IS_ERR(bh)) { 2439 err = PTR_ERR(bh); 2440 } else { 2441 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2442 value_len, is_create); 2443 brelse(bh); 2444 err = 0; 2445 } 2446 2447 up_read(&EXT4_I(inode)->xattr_sem); 2448 return err; 2449 } 2450 2451 /* 2452 * ext4_xattr_set() 2453 * 2454 * Like ext4_xattr_set_handle, but start from an inode. This extended 2455 * attribute modification is a filesystem transaction by itself. 2456 * 2457 * Returns 0, or a negative error number on failure. 2458 */ 2459 int 2460 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2461 const void *value, size_t value_len, int flags) 2462 { 2463 handle_t *handle; 2464 struct super_block *sb = inode->i_sb; 2465 int error, retries = 0; 2466 int credits; 2467 2468 error = dquot_initialize(inode); 2469 if (error) 2470 return error; 2471 2472 retry: 2473 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2474 &credits); 2475 if (error) 2476 return error; 2477 2478 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2479 if (IS_ERR(handle)) { 2480 error = PTR_ERR(handle); 2481 } else { 2482 int error2; 2483 2484 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2485 value, value_len, flags); 2486 error2 = ext4_journal_stop(handle); 2487 if (error == -ENOSPC && 2488 ext4_should_retry_alloc(sb, &retries)) 2489 goto retry; 2490 if (error == 0) 2491 error = error2; 2492 } 2493 2494 return error; 2495 } 2496 2497 /* 2498 * Shift the EA entries in the inode to create space for the increased 2499 * i_extra_isize. 2500 */ 2501 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2502 int value_offs_shift, void *to, 2503 void *from, size_t n) 2504 { 2505 struct ext4_xattr_entry *last = entry; 2506 int new_offs; 2507 2508 /* We always shift xattr headers further thus offsets get lower */ 2509 BUG_ON(value_offs_shift > 0); 2510 2511 /* Adjust the value offsets of the entries */ 2512 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2513 if (!last->e_value_inum && last->e_value_size) { 2514 new_offs = le16_to_cpu(last->e_value_offs) + 2515 value_offs_shift; 2516 last->e_value_offs = cpu_to_le16(new_offs); 2517 } 2518 } 2519 /* Shift the entries by n bytes */ 2520 memmove(to, from, n); 2521 } 2522 2523 /* 2524 * Move xattr pointed to by 'entry' from inode into external xattr block 2525 */ 2526 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2527 struct ext4_inode *raw_inode, 2528 struct ext4_xattr_entry *entry) 2529 { 2530 struct ext4_xattr_ibody_find *is = NULL; 2531 struct ext4_xattr_block_find *bs = NULL; 2532 char *buffer = NULL, *b_entry_name = NULL; 2533 size_t value_size = le32_to_cpu(entry->e_value_size); 2534 struct ext4_xattr_info i = { 2535 .value = NULL, 2536 .value_len = 0, 2537 .name_index = entry->e_name_index, 2538 .in_inode = !!entry->e_value_inum, 2539 }; 2540 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2541 int error; 2542 2543 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2544 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2545 buffer = kmalloc(value_size, GFP_NOFS); 2546 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2547 if (!is || !bs || !buffer || !b_entry_name) { 2548 error = -ENOMEM; 2549 goto out; 2550 } 2551 2552 is->s.not_found = -ENODATA; 2553 bs->s.not_found = -ENODATA; 2554 is->iloc.bh = NULL; 2555 bs->bh = NULL; 2556 2557 /* Save the entry name and the entry value */ 2558 if (entry->e_value_inum) { 2559 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2560 if (error) 2561 goto out; 2562 } else { 2563 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2564 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2565 } 2566 2567 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2568 b_entry_name[entry->e_name_len] = '\0'; 2569 i.name = b_entry_name; 2570 2571 error = ext4_get_inode_loc(inode, &is->iloc); 2572 if (error) 2573 goto out; 2574 2575 error = ext4_xattr_ibody_find(inode, &i, is); 2576 if (error) 2577 goto out; 2578 2579 /* Remove the chosen entry from the inode */ 2580 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2581 if (error) 2582 goto out; 2583 2584 i.value = buffer; 2585 i.value_len = value_size; 2586 error = ext4_xattr_block_find(inode, &i, bs); 2587 if (error) 2588 goto out; 2589 2590 /* Add entry which was removed from the inode into the block */ 2591 error = ext4_xattr_block_set(handle, inode, &i, bs); 2592 if (error) 2593 goto out; 2594 error = 0; 2595 out: 2596 kfree(b_entry_name); 2597 kfree(buffer); 2598 if (is) 2599 brelse(is->iloc.bh); 2600 if (bs) 2601 brelse(bs->bh); 2602 kfree(is); 2603 kfree(bs); 2604 2605 return error; 2606 } 2607 2608 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2609 struct ext4_inode *raw_inode, 2610 int isize_diff, size_t ifree, 2611 size_t bfree, int *total_ino) 2612 { 2613 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2614 struct ext4_xattr_entry *small_entry; 2615 struct ext4_xattr_entry *entry; 2616 struct ext4_xattr_entry *last; 2617 unsigned int entry_size; /* EA entry size */ 2618 unsigned int total_size; /* EA entry size + value size */ 2619 unsigned int min_total_size; 2620 int error; 2621 2622 while (isize_diff > ifree) { 2623 entry = NULL; 2624 small_entry = NULL; 2625 min_total_size = ~0U; 2626 last = IFIRST(header); 2627 /* Find the entry best suited to be pushed into EA block */ 2628 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2629 /* never move system.data out of the inode */ 2630 if ((last->e_name_len == 4) && 2631 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) && 2632 !memcmp(last->e_name, "data", 4)) 2633 continue; 2634 total_size = EXT4_XATTR_LEN(last->e_name_len); 2635 if (!last->e_value_inum) 2636 total_size += EXT4_XATTR_SIZE( 2637 le32_to_cpu(last->e_value_size)); 2638 if (total_size <= bfree && 2639 total_size < min_total_size) { 2640 if (total_size + ifree < isize_diff) { 2641 small_entry = last; 2642 } else { 2643 entry = last; 2644 min_total_size = total_size; 2645 } 2646 } 2647 } 2648 2649 if (entry == NULL) { 2650 if (small_entry == NULL) 2651 return -ENOSPC; 2652 entry = small_entry; 2653 } 2654 2655 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2656 total_size = entry_size; 2657 if (!entry->e_value_inum) 2658 total_size += EXT4_XATTR_SIZE( 2659 le32_to_cpu(entry->e_value_size)); 2660 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2661 entry); 2662 if (error) 2663 return error; 2664 2665 *total_ino -= entry_size; 2666 ifree += total_size; 2667 bfree -= total_size; 2668 } 2669 2670 return 0; 2671 } 2672 2673 /* 2674 * Expand an inode by new_extra_isize bytes when EAs are present. 2675 * Returns 0 on success or negative error number on failure. 2676 */ 2677 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2678 struct ext4_inode *raw_inode, handle_t *handle) 2679 { 2680 struct ext4_xattr_ibody_header *header; 2681 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2682 static unsigned int mnt_count; 2683 size_t min_offs; 2684 size_t ifree, bfree; 2685 int total_ino; 2686 void *base, *end; 2687 int error = 0, tried_min_extra_isize = 0; 2688 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2689 int isize_diff; /* How much do we need to grow i_extra_isize */ 2690 2691 retry: 2692 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2693 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2694 return 0; 2695 2696 header = IHDR(inode, raw_inode); 2697 2698 /* 2699 * Check if enough free space is available in the inode to shift the 2700 * entries ahead by new_extra_isize. 2701 */ 2702 2703 base = IFIRST(header); 2704 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2705 min_offs = end - base; 2706 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32); 2707 2708 error = xattr_check_inode(inode, header, end); 2709 if (error) 2710 goto cleanup; 2711 2712 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2713 if (ifree >= isize_diff) 2714 goto shift; 2715 2716 /* 2717 * Enough free space isn't available in the inode, check if 2718 * EA block can hold new_extra_isize bytes. 2719 */ 2720 if (EXT4_I(inode)->i_file_acl) { 2721 struct buffer_head *bh; 2722 2723 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2724 if (IS_ERR(bh)) { 2725 error = PTR_ERR(bh); 2726 goto cleanup; 2727 } 2728 error = ext4_xattr_check_block(inode, bh); 2729 if (error) { 2730 brelse(bh); 2731 goto cleanup; 2732 } 2733 base = BHDR(bh); 2734 end = bh->b_data + bh->b_size; 2735 min_offs = end - base; 2736 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2737 NULL); 2738 brelse(bh); 2739 if (bfree + ifree < isize_diff) { 2740 if (!tried_min_extra_isize && s_min_extra_isize) { 2741 tried_min_extra_isize++; 2742 new_extra_isize = s_min_extra_isize; 2743 goto retry; 2744 } 2745 error = -ENOSPC; 2746 goto cleanup; 2747 } 2748 } else { 2749 bfree = inode->i_sb->s_blocksize; 2750 } 2751 2752 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2753 isize_diff, ifree, bfree, 2754 &total_ino); 2755 if (error) { 2756 if (error == -ENOSPC && !tried_min_extra_isize && 2757 s_min_extra_isize) { 2758 tried_min_extra_isize++; 2759 new_extra_isize = s_min_extra_isize; 2760 goto retry; 2761 } 2762 goto cleanup; 2763 } 2764 shift: 2765 /* Adjust the offsets and shift the remaining entries ahead */ 2766 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2767 - new_extra_isize, (void *)raw_inode + 2768 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2769 (void *)header, total_ino); 2770 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2771 2772 cleanup: 2773 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2774 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2775 inode->i_ino); 2776 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2777 } 2778 return error; 2779 } 2780 2781 #define EIA_INCR 16 /* must be 2^n */ 2782 #define EIA_MASK (EIA_INCR - 1) 2783 2784 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2785 * If @ea_inode_array is new or full it will be grown and the old 2786 * contents copied over. 2787 */ 2788 static int 2789 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2790 struct inode *inode) 2791 { 2792 if (*ea_inode_array == NULL) { 2793 /* 2794 * Start with 15 inodes, so it fits into a power-of-two size. 2795 * If *ea_inode_array is NULL, this is essentially offsetof() 2796 */ 2797 (*ea_inode_array) = 2798 kmalloc(offsetof(struct ext4_xattr_inode_array, 2799 inodes[EIA_MASK]), 2800 GFP_NOFS); 2801 if (*ea_inode_array == NULL) 2802 return -ENOMEM; 2803 (*ea_inode_array)->count = 0; 2804 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2805 /* expand the array once all 15 + n * 16 slots are full */ 2806 struct ext4_xattr_inode_array *new_array = NULL; 2807 int count = (*ea_inode_array)->count; 2808 2809 /* if new_array is NULL, this is essentially offsetof() */ 2810 new_array = kmalloc( 2811 offsetof(struct ext4_xattr_inode_array, 2812 inodes[count + EIA_INCR]), 2813 GFP_NOFS); 2814 if (new_array == NULL) 2815 return -ENOMEM; 2816 memcpy(new_array, *ea_inode_array, 2817 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2818 kfree(*ea_inode_array); 2819 *ea_inode_array = new_array; 2820 } 2821 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2822 return 0; 2823 } 2824 2825 /* 2826 * ext4_xattr_delete_inode() 2827 * 2828 * Free extended attribute resources associated with this inode. Traverse 2829 * all entries and decrement reference on any xattr inodes associated with this 2830 * inode. This is called immediately before an inode is freed. We have exclusive 2831 * access to the inode. If an orphan inode is deleted it will also release its 2832 * references on xattr block and xattr inodes. 2833 */ 2834 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2835 struct ext4_xattr_inode_array **ea_inode_array, 2836 int extra_credits) 2837 { 2838 struct buffer_head *bh = NULL; 2839 struct ext4_xattr_ibody_header *header; 2840 struct ext4_iloc iloc = { .bh = NULL }; 2841 struct ext4_xattr_entry *entry; 2842 struct inode *ea_inode; 2843 int error; 2844 2845 error = ext4_journal_ensure_credits(handle, extra_credits, 2846 ext4_free_metadata_revoke_credits(inode->i_sb, 1)); 2847 if (error < 0) { 2848 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2849 goto cleanup; 2850 } 2851 2852 if (ext4_has_feature_ea_inode(inode->i_sb) && 2853 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2854 2855 error = ext4_get_inode_loc(inode, &iloc); 2856 if (error) { 2857 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2858 goto cleanup; 2859 } 2860 2861 error = ext4_journal_get_write_access(handle, iloc.bh); 2862 if (error) { 2863 EXT4_ERROR_INODE(inode, "write access (error %d)", 2864 error); 2865 goto cleanup; 2866 } 2867 2868 header = IHDR(inode, ext4_raw_inode(&iloc)); 2869 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2870 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2871 IFIRST(header), 2872 false /* block_csum */, 2873 ea_inode_array, 2874 extra_credits, 2875 false /* skip_quota */); 2876 } 2877 2878 if (EXT4_I(inode)->i_file_acl) { 2879 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2880 if (IS_ERR(bh)) { 2881 error = PTR_ERR(bh); 2882 if (error == -EIO) { 2883 ext4_set_errno(inode->i_sb, EIO); 2884 EXT4_ERROR_INODE(inode, "block %llu read error", 2885 EXT4_I(inode)->i_file_acl); 2886 } 2887 bh = NULL; 2888 goto cleanup; 2889 } 2890 error = ext4_xattr_check_block(inode, bh); 2891 if (error) 2892 goto cleanup; 2893 2894 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2895 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2896 entry = EXT4_XATTR_NEXT(entry)) { 2897 if (!entry->e_value_inum) 2898 continue; 2899 error = ext4_xattr_inode_iget(inode, 2900 le32_to_cpu(entry->e_value_inum), 2901 le32_to_cpu(entry->e_hash), 2902 &ea_inode); 2903 if (error) 2904 continue; 2905 ext4_xattr_inode_free_quota(inode, ea_inode, 2906 le32_to_cpu(entry->e_value_size)); 2907 iput(ea_inode); 2908 } 2909 2910 } 2911 2912 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2913 extra_credits); 2914 /* 2915 * Update i_file_acl value in the same transaction that releases 2916 * block. 2917 */ 2918 EXT4_I(inode)->i_file_acl = 0; 2919 error = ext4_mark_inode_dirty(handle, inode); 2920 if (error) { 2921 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2922 error); 2923 goto cleanup; 2924 } 2925 } 2926 error = 0; 2927 cleanup: 2928 brelse(iloc.bh); 2929 brelse(bh); 2930 return error; 2931 } 2932 2933 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2934 { 2935 int idx; 2936 2937 if (ea_inode_array == NULL) 2938 return; 2939 2940 for (idx = 0; idx < ea_inode_array->count; ++idx) 2941 iput(ea_inode_array->inodes[idx]); 2942 kfree(ea_inode_array); 2943 } 2944 2945 /* 2946 * ext4_xattr_block_cache_insert() 2947 * 2948 * Create a new entry in the extended attribute block cache, and insert 2949 * it unless such an entry is already in the cache. 2950 * 2951 * Returns 0, or a negative error number on failure. 2952 */ 2953 static void 2954 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2955 struct buffer_head *bh) 2956 { 2957 struct ext4_xattr_header *header = BHDR(bh); 2958 __u32 hash = le32_to_cpu(header->h_hash); 2959 int reusable = le32_to_cpu(header->h_refcount) < 2960 EXT4_XATTR_REFCOUNT_MAX; 2961 int error; 2962 2963 if (!ea_block_cache) 2964 return; 2965 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2966 bh->b_blocknr, reusable); 2967 if (error) { 2968 if (error == -EBUSY) 2969 ea_bdebug(bh, "already in cache"); 2970 } else 2971 ea_bdebug(bh, "inserting [%x]", (int)hash); 2972 } 2973 2974 /* 2975 * ext4_xattr_cmp() 2976 * 2977 * Compare two extended attribute blocks for equality. 2978 * 2979 * Returns 0 if the blocks are equal, 1 if they differ, and 2980 * a negative error number on errors. 2981 */ 2982 static int 2983 ext4_xattr_cmp(struct ext4_xattr_header *header1, 2984 struct ext4_xattr_header *header2) 2985 { 2986 struct ext4_xattr_entry *entry1, *entry2; 2987 2988 entry1 = ENTRY(header1+1); 2989 entry2 = ENTRY(header2+1); 2990 while (!IS_LAST_ENTRY(entry1)) { 2991 if (IS_LAST_ENTRY(entry2)) 2992 return 1; 2993 if (entry1->e_hash != entry2->e_hash || 2994 entry1->e_name_index != entry2->e_name_index || 2995 entry1->e_name_len != entry2->e_name_len || 2996 entry1->e_value_size != entry2->e_value_size || 2997 entry1->e_value_inum != entry2->e_value_inum || 2998 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 2999 return 1; 3000 if (!entry1->e_value_inum && 3001 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 3002 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 3003 le32_to_cpu(entry1->e_value_size))) 3004 return 1; 3005 3006 entry1 = EXT4_XATTR_NEXT(entry1); 3007 entry2 = EXT4_XATTR_NEXT(entry2); 3008 } 3009 if (!IS_LAST_ENTRY(entry2)) 3010 return 1; 3011 return 0; 3012 } 3013 3014 /* 3015 * ext4_xattr_block_cache_find() 3016 * 3017 * Find an identical extended attribute block. 3018 * 3019 * Returns a pointer to the block found, or NULL if such a block was 3020 * not found or an error occurred. 3021 */ 3022 static struct buffer_head * 3023 ext4_xattr_block_cache_find(struct inode *inode, 3024 struct ext4_xattr_header *header, 3025 struct mb_cache_entry **pce) 3026 { 3027 __u32 hash = le32_to_cpu(header->h_hash); 3028 struct mb_cache_entry *ce; 3029 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 3030 3031 if (!ea_block_cache) 3032 return NULL; 3033 if (!header->h_hash) 3034 return NULL; /* never share */ 3035 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 3036 ce = mb_cache_entry_find_first(ea_block_cache, hash); 3037 while (ce) { 3038 struct buffer_head *bh; 3039 3040 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO); 3041 if (IS_ERR(bh)) { 3042 if (PTR_ERR(bh) == -ENOMEM) 3043 return NULL; 3044 bh = NULL; 3045 EXT4_ERROR_INODE(inode, "block %lu read error", 3046 (unsigned long)ce->e_value); 3047 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 3048 *pce = ce; 3049 return bh; 3050 } 3051 brelse(bh); 3052 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3053 } 3054 return NULL; 3055 } 3056 3057 #define NAME_HASH_SHIFT 5 3058 #define VALUE_HASH_SHIFT 16 3059 3060 /* 3061 * ext4_xattr_hash_entry() 3062 * 3063 * Compute the hash of an extended attribute. 3064 */ 3065 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3066 size_t value_count) 3067 { 3068 __u32 hash = 0; 3069 3070 while (name_len--) { 3071 hash = (hash << NAME_HASH_SHIFT) ^ 3072 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3073 *name++; 3074 } 3075 while (value_count--) { 3076 hash = (hash << VALUE_HASH_SHIFT) ^ 3077 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3078 le32_to_cpu(*value++); 3079 } 3080 return cpu_to_le32(hash); 3081 } 3082 3083 #undef NAME_HASH_SHIFT 3084 #undef VALUE_HASH_SHIFT 3085 3086 #define BLOCK_HASH_SHIFT 16 3087 3088 /* 3089 * ext4_xattr_rehash() 3090 * 3091 * Re-compute the extended attribute hash value after an entry has changed. 3092 */ 3093 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3094 { 3095 struct ext4_xattr_entry *here; 3096 __u32 hash = 0; 3097 3098 here = ENTRY(header+1); 3099 while (!IS_LAST_ENTRY(here)) { 3100 if (!here->e_hash) { 3101 /* Block is not shared if an entry's hash value == 0 */ 3102 hash = 0; 3103 break; 3104 } 3105 hash = (hash << BLOCK_HASH_SHIFT) ^ 3106 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3107 le32_to_cpu(here->e_hash); 3108 here = EXT4_XATTR_NEXT(here); 3109 } 3110 header->h_hash = cpu_to_le32(hash); 3111 } 3112 3113 #undef BLOCK_HASH_SHIFT 3114 3115 #define HASH_BUCKET_BITS 10 3116 3117 struct mb_cache * 3118 ext4_xattr_create_cache(void) 3119 { 3120 return mb_cache_create(HASH_BUCKET_BITS); 3121 } 3122 3123 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3124 { 3125 if (cache) 3126 mb_cache_destroy(cache); 3127 } 3128 3129