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 __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value, 85 size_t value_count); 86 static void ext4_xattr_rehash(struct ext4_xattr_header *); 87 88 static const struct xattr_handler * const ext4_xattr_handler_map[] = { 89 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, 90 #ifdef CONFIG_EXT4_FS_POSIX_ACL 91 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 92 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 93 #endif 94 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, 95 #ifdef CONFIG_EXT4_FS_SECURITY 96 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, 97 #endif 98 [EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler, 99 }; 100 101 const struct xattr_handler *ext4_xattr_handlers[] = { 102 &ext4_xattr_user_handler, 103 &ext4_xattr_trusted_handler, 104 #ifdef CONFIG_EXT4_FS_POSIX_ACL 105 &posix_acl_access_xattr_handler, 106 &posix_acl_default_xattr_handler, 107 #endif 108 #ifdef CONFIG_EXT4_FS_SECURITY 109 &ext4_xattr_security_handler, 110 #endif 111 &ext4_xattr_hurd_handler, 112 NULL 113 }; 114 115 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ 116 inode->i_sb->s_fs_info)->s_ea_block_cache) 117 118 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \ 119 inode->i_sb->s_fs_info)->s_ea_inode_cache) 120 121 static int 122 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 123 struct inode *inode); 124 125 #ifdef CONFIG_LOCKDEP 126 void ext4_xattr_inode_set_class(struct inode *ea_inode) 127 { 128 lockdep_set_subclass(&ea_inode->i_rwsem, 1); 129 } 130 #endif 131 132 static __le32 ext4_xattr_block_csum(struct inode *inode, 133 sector_t block_nr, 134 struct ext4_xattr_header *hdr) 135 { 136 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 137 __u32 csum; 138 __le64 dsk_block_nr = cpu_to_le64(block_nr); 139 __u32 dummy_csum = 0; 140 int offset = offsetof(struct ext4_xattr_header, h_checksum); 141 142 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr, 143 sizeof(dsk_block_nr)); 144 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset); 145 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 146 offset += sizeof(dummy_csum); 147 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset, 148 EXT4_BLOCK_SIZE(inode->i_sb) - offset); 149 150 return cpu_to_le32(csum); 151 } 152 153 static int ext4_xattr_block_csum_verify(struct inode *inode, 154 struct buffer_head *bh) 155 { 156 struct ext4_xattr_header *hdr = BHDR(bh); 157 int ret = 1; 158 159 if (ext4_has_metadata_csum(inode->i_sb)) { 160 lock_buffer(bh); 161 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, 162 bh->b_blocknr, hdr)); 163 unlock_buffer(bh); 164 } 165 return ret; 166 } 167 168 static void ext4_xattr_block_csum_set(struct inode *inode, 169 struct buffer_head *bh) 170 { 171 if (ext4_has_metadata_csum(inode->i_sb)) 172 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, 173 bh->b_blocknr, BHDR(bh)); 174 } 175 176 static inline const struct xattr_handler * 177 ext4_xattr_handler(int name_index) 178 { 179 const struct xattr_handler *handler = NULL; 180 181 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) 182 handler = ext4_xattr_handler_map[name_index]; 183 return handler; 184 } 185 186 static int 187 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, 188 void *value_start) 189 { 190 struct ext4_xattr_entry *e = entry; 191 192 /* Find the end of the names list */ 193 while (!IS_LAST_ENTRY(e)) { 194 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); 195 if ((void *)next >= end) 196 return -EFSCORRUPTED; 197 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) 198 return -EFSCORRUPTED; 199 e = next; 200 } 201 202 /* Check the values */ 203 while (!IS_LAST_ENTRY(entry)) { 204 u32 size = le32_to_cpu(entry->e_value_size); 205 206 if (size > EXT4_XATTR_SIZE_MAX) 207 return -EFSCORRUPTED; 208 209 if (size != 0 && entry->e_value_inum == 0) { 210 u16 offs = le16_to_cpu(entry->e_value_offs); 211 void *value; 212 213 /* 214 * The value cannot overlap the names, and the value 215 * with padding cannot extend beyond 'end'. Check both 216 * the padded and unpadded sizes, since the size may 217 * overflow to 0 when adding padding. 218 */ 219 if (offs > end - value_start) 220 return -EFSCORRUPTED; 221 value = value_start + offs; 222 if (value < (void *)e + sizeof(u32) || 223 size > end - value || 224 EXT4_XATTR_SIZE(size) > end - value) 225 return -EFSCORRUPTED; 226 } 227 entry = EXT4_XATTR_NEXT(entry); 228 } 229 230 return 0; 231 } 232 233 static inline int 234 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, 235 const char *function, unsigned int line) 236 { 237 int error = -EFSCORRUPTED; 238 239 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || 240 BHDR(bh)->h_blocks != cpu_to_le32(1)) 241 goto errout; 242 if (buffer_verified(bh)) 243 return 0; 244 245 error = -EFSBADCRC; 246 if (!ext4_xattr_block_csum_verify(inode, bh)) 247 goto errout; 248 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, 249 bh->b_data); 250 errout: 251 if (error) 252 __ext4_error_inode(inode, function, line, 0, -error, 253 "corrupted xattr block %llu", 254 (unsigned long long) bh->b_blocknr); 255 else 256 set_buffer_verified(bh); 257 return error; 258 } 259 260 #define ext4_xattr_check_block(inode, bh) \ 261 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) 262 263 264 static int 265 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, 266 void *end, const char *function, unsigned int line) 267 { 268 int error = -EFSCORRUPTED; 269 270 if (end - (void *)header < sizeof(*header) + sizeof(u32) || 271 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC))) 272 goto errout; 273 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header)); 274 errout: 275 if (error) 276 __ext4_error_inode(inode, function, line, 0, -error, 277 "corrupted in-inode xattr"); 278 return error; 279 } 280 281 #define xattr_check_inode(inode, header, end) \ 282 __xattr_check_inode((inode), (header), (end), __func__, __LINE__) 283 284 static int 285 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, 286 void *end, int name_index, const char *name, int sorted) 287 { 288 struct ext4_xattr_entry *entry, *next; 289 size_t name_len; 290 int cmp = 1; 291 292 if (name == NULL) 293 return -EINVAL; 294 name_len = strlen(name); 295 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { 296 next = EXT4_XATTR_NEXT(entry); 297 if ((void *) next >= end) { 298 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 299 return -EFSCORRUPTED; 300 } 301 cmp = name_index - entry->e_name_index; 302 if (!cmp) 303 cmp = name_len - entry->e_name_len; 304 if (!cmp) 305 cmp = memcmp(name, entry->e_name, name_len); 306 if (cmp <= 0 && (sorted || cmp == 0)) 307 break; 308 } 309 *pentry = entry; 310 return cmp ? -ENODATA : 0; 311 } 312 313 static u32 314 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size) 315 { 316 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size); 317 } 318 319 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode) 320 { 321 return ((u64)ea_inode->i_ctime.tv_sec << 32) | 322 (u32) inode_peek_iversion_raw(ea_inode); 323 } 324 325 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count) 326 { 327 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32); 328 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff); 329 } 330 331 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode) 332 { 333 return (u32)ea_inode->i_atime.tv_sec; 334 } 335 336 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash) 337 { 338 ea_inode->i_atime.tv_sec = hash; 339 } 340 341 /* 342 * Read the EA value from an inode. 343 */ 344 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) 345 { 346 int blocksize = 1 << ea_inode->i_blkbits; 347 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits; 348 int tail_size = (size % blocksize) ?: blocksize; 349 struct buffer_head *bhs_inline[8]; 350 struct buffer_head **bhs = bhs_inline; 351 int i, ret; 352 353 if (bh_count > ARRAY_SIZE(bhs_inline)) { 354 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS); 355 if (!bhs) 356 return -ENOMEM; 357 } 358 359 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count, 360 true /* wait */, bhs); 361 if (ret) 362 goto free_bhs; 363 364 for (i = 0; i < bh_count; i++) { 365 /* There shouldn't be any holes in ea_inode. */ 366 if (!bhs[i]) { 367 ret = -EFSCORRUPTED; 368 goto put_bhs; 369 } 370 memcpy((char *)buf + blocksize * i, bhs[i]->b_data, 371 i < bh_count - 1 ? blocksize : tail_size); 372 } 373 ret = 0; 374 put_bhs: 375 for (i = 0; i < bh_count; i++) 376 brelse(bhs[i]); 377 free_bhs: 378 if (bhs != bhs_inline) 379 kfree(bhs); 380 return ret; 381 } 382 383 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec) 384 385 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, 386 u32 ea_inode_hash, struct inode **ea_inode) 387 { 388 struct inode *inode; 389 int err; 390 391 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL); 392 if (IS_ERR(inode)) { 393 err = PTR_ERR(inode); 394 ext4_error(parent->i_sb, 395 "error while reading EA inode %lu err=%d", ea_ino, 396 err); 397 return err; 398 } 399 400 if (is_bad_inode(inode)) { 401 ext4_error(parent->i_sb, 402 "error while reading EA inode %lu is_bad_inode", 403 ea_ino); 404 err = -EIO; 405 goto error; 406 } 407 408 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { 409 ext4_error(parent->i_sb, 410 "EA inode %lu does not have EXT4_EA_INODE_FL flag", 411 ea_ino); 412 err = -EINVAL; 413 goto error; 414 } 415 416 ext4_xattr_inode_set_class(inode); 417 418 /* 419 * Check whether this is an old Lustre-style xattr inode. Lustre 420 * implementation does not have hash validation, rather it has a 421 * backpointer from ea_inode to the parent inode. 422 */ 423 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) && 424 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino && 425 inode->i_generation == parent->i_generation) { 426 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE); 427 ext4_xattr_inode_set_ref(inode, 1); 428 } else { 429 inode_lock(inode); 430 inode->i_flags |= S_NOQUOTA; 431 inode_unlock(inode); 432 } 433 434 *ea_inode = inode; 435 return 0; 436 error: 437 iput(inode); 438 return err; 439 } 440 441 /* Remove entry from mbcache when EA inode is getting evicted */ 442 void ext4_evict_ea_inode(struct inode *inode) 443 { 444 struct mb_cache_entry *oe; 445 446 if (!EA_INODE_CACHE(inode)) 447 return; 448 /* Wait for entry to get unused so that we can remove it */ 449 while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode), 450 ext4_xattr_inode_get_hash(inode), inode->i_ino))) { 451 mb_cache_entry_wait_unused(oe); 452 mb_cache_entry_put(EA_INODE_CACHE(inode), oe); 453 } 454 } 455 456 static int 457 ext4_xattr_inode_verify_hashes(struct inode *ea_inode, 458 struct ext4_xattr_entry *entry, void *buffer, 459 size_t size) 460 { 461 u32 hash; 462 463 /* Verify stored hash matches calculated hash. */ 464 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size); 465 if (hash != ext4_xattr_inode_get_hash(ea_inode)) 466 return -EFSCORRUPTED; 467 468 if (entry) { 469 __le32 e_hash, tmp_data; 470 471 /* Verify entry hash. */ 472 tmp_data = cpu_to_le32(hash); 473 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len, 474 &tmp_data, 1); 475 /* All good? */ 476 if (e_hash == entry->e_hash) 477 return 0; 478 479 /* 480 * Not good. Maybe the entry hash was calculated 481 * using the buggy signed char version? 482 */ 483 e_hash = ext4_xattr_hash_entry_signed(entry->e_name, entry->e_name_len, 484 &tmp_data, 1); 485 if (e_hash == entry->e_hash) 486 return 0; 487 488 /* Still no match - bad */ 489 return -EFSCORRUPTED; 490 } 491 return 0; 492 } 493 494 /* 495 * Read xattr value from the EA inode. 496 */ 497 static int 498 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry, 499 void *buffer, size_t size) 500 { 501 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 502 struct inode *ea_inode; 503 int err; 504 505 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum), 506 le32_to_cpu(entry->e_hash), &ea_inode); 507 if (err) { 508 ea_inode = NULL; 509 goto out; 510 } 511 512 if (i_size_read(ea_inode) != size) { 513 ext4_warning_inode(ea_inode, 514 "ea_inode file size=%llu entry size=%zu", 515 i_size_read(ea_inode), size); 516 err = -EFSCORRUPTED; 517 goto out; 518 } 519 520 err = ext4_xattr_inode_read(ea_inode, buffer, size); 521 if (err) 522 goto out; 523 524 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) { 525 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer, 526 size); 527 if (err) { 528 ext4_warning_inode(ea_inode, 529 "EA inode hash validation failed"); 530 goto out; 531 } 532 533 if (ea_inode_cache) 534 mb_cache_entry_create(ea_inode_cache, GFP_NOFS, 535 ext4_xattr_inode_get_hash(ea_inode), 536 ea_inode->i_ino, true /* reusable */); 537 } 538 out: 539 iput(ea_inode); 540 return err; 541 } 542 543 static int 544 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, 545 void *buffer, size_t buffer_size) 546 { 547 struct buffer_head *bh = NULL; 548 struct ext4_xattr_entry *entry; 549 size_t size; 550 void *end; 551 int error; 552 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 553 554 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 555 name_index, name, buffer, (long)buffer_size); 556 557 if (!EXT4_I(inode)->i_file_acl) 558 return -ENODATA; 559 ea_idebug(inode, "reading block %llu", 560 (unsigned long long)EXT4_I(inode)->i_file_acl); 561 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 562 if (IS_ERR(bh)) 563 return PTR_ERR(bh); 564 ea_bdebug(bh, "b_count=%d, refcount=%d", 565 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 566 error = ext4_xattr_check_block(inode, bh); 567 if (error) 568 goto cleanup; 569 ext4_xattr_block_cache_insert(ea_block_cache, bh); 570 entry = BFIRST(bh); 571 end = bh->b_data + bh->b_size; 572 error = xattr_find_entry(inode, &entry, end, name_index, name, 1); 573 if (error) 574 goto cleanup; 575 size = le32_to_cpu(entry->e_value_size); 576 error = -ERANGE; 577 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 578 goto cleanup; 579 if (buffer) { 580 if (size > buffer_size) 581 goto cleanup; 582 if (entry->e_value_inum) { 583 error = ext4_xattr_inode_get(inode, entry, buffer, 584 size); 585 if (error) 586 goto cleanup; 587 } else { 588 u16 offset = le16_to_cpu(entry->e_value_offs); 589 void *p = bh->b_data + offset; 590 591 if (unlikely(p + size > end)) 592 goto cleanup; 593 memcpy(buffer, p, size); 594 } 595 } 596 error = size; 597 598 cleanup: 599 brelse(bh); 600 return error; 601 } 602 603 int 604 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 605 void *buffer, size_t buffer_size) 606 { 607 struct ext4_xattr_ibody_header *header; 608 struct ext4_xattr_entry *entry; 609 struct ext4_inode *raw_inode; 610 struct ext4_iloc iloc; 611 size_t size; 612 void *end; 613 int error; 614 615 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 616 return -ENODATA; 617 error = ext4_get_inode_loc(inode, &iloc); 618 if (error) 619 return error; 620 raw_inode = ext4_raw_inode(&iloc); 621 header = IHDR(inode, raw_inode); 622 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 623 error = xattr_check_inode(inode, header, end); 624 if (error) 625 goto cleanup; 626 entry = IFIRST(header); 627 error = xattr_find_entry(inode, &entry, end, name_index, name, 0); 628 if (error) 629 goto cleanup; 630 size = le32_to_cpu(entry->e_value_size); 631 error = -ERANGE; 632 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 633 goto cleanup; 634 if (buffer) { 635 if (size > buffer_size) 636 goto cleanup; 637 if (entry->e_value_inum) { 638 error = ext4_xattr_inode_get(inode, entry, buffer, 639 size); 640 if (error) 641 goto cleanup; 642 } else { 643 u16 offset = le16_to_cpu(entry->e_value_offs); 644 void *p = (void *)IFIRST(header) + offset; 645 646 if (unlikely(p + size > end)) 647 goto cleanup; 648 memcpy(buffer, p, size); 649 } 650 } 651 error = size; 652 653 cleanup: 654 brelse(iloc.bh); 655 return error; 656 } 657 658 /* 659 * ext4_xattr_get() 660 * 661 * Copy an extended attribute into the buffer 662 * provided, or compute the buffer size required. 663 * Buffer is NULL to compute the size of the buffer required. 664 * 665 * Returns a negative error number on failure, or the number of bytes 666 * used / required on success. 667 */ 668 int 669 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 670 void *buffer, size_t buffer_size) 671 { 672 int error; 673 674 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 675 return -EIO; 676 677 if (strlen(name) > 255) 678 return -ERANGE; 679 680 down_read(&EXT4_I(inode)->xattr_sem); 681 error = ext4_xattr_ibody_get(inode, name_index, name, buffer, 682 buffer_size); 683 if (error == -ENODATA) 684 error = ext4_xattr_block_get(inode, name_index, name, buffer, 685 buffer_size); 686 up_read(&EXT4_I(inode)->xattr_sem); 687 return error; 688 } 689 690 static int 691 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, 692 char *buffer, size_t buffer_size) 693 { 694 size_t rest = buffer_size; 695 696 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 697 const struct xattr_handler *handler = 698 ext4_xattr_handler(entry->e_name_index); 699 700 if (handler && (!handler->list || handler->list(dentry))) { 701 const char *prefix = handler->prefix ?: handler->name; 702 size_t prefix_len = strlen(prefix); 703 size_t size = prefix_len + entry->e_name_len + 1; 704 705 if (buffer) { 706 if (size > rest) 707 return -ERANGE; 708 memcpy(buffer, prefix, prefix_len); 709 buffer += prefix_len; 710 memcpy(buffer, entry->e_name, entry->e_name_len); 711 buffer += entry->e_name_len; 712 *buffer++ = 0; 713 } 714 rest -= size; 715 } 716 } 717 return buffer_size - rest; /* total size */ 718 } 719 720 static int 721 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) 722 { 723 struct inode *inode = d_inode(dentry); 724 struct buffer_head *bh = NULL; 725 int error; 726 727 ea_idebug(inode, "buffer=%p, buffer_size=%ld", 728 buffer, (long)buffer_size); 729 730 if (!EXT4_I(inode)->i_file_acl) 731 return 0; 732 ea_idebug(inode, "reading block %llu", 733 (unsigned long long)EXT4_I(inode)->i_file_acl); 734 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 735 if (IS_ERR(bh)) 736 return PTR_ERR(bh); 737 ea_bdebug(bh, "b_count=%d, refcount=%d", 738 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 739 error = ext4_xattr_check_block(inode, bh); 740 if (error) 741 goto cleanup; 742 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); 743 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, 744 buffer_size); 745 cleanup: 746 brelse(bh); 747 return error; 748 } 749 750 static int 751 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 752 { 753 struct inode *inode = d_inode(dentry); 754 struct ext4_xattr_ibody_header *header; 755 struct ext4_inode *raw_inode; 756 struct ext4_iloc iloc; 757 void *end; 758 int error; 759 760 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 761 return 0; 762 error = ext4_get_inode_loc(inode, &iloc); 763 if (error) 764 return error; 765 raw_inode = ext4_raw_inode(&iloc); 766 header = IHDR(inode, raw_inode); 767 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 768 error = xattr_check_inode(inode, header, end); 769 if (error) 770 goto cleanup; 771 error = ext4_xattr_list_entries(dentry, IFIRST(header), 772 buffer, buffer_size); 773 774 cleanup: 775 brelse(iloc.bh); 776 return error; 777 } 778 779 /* 780 * Inode operation listxattr() 781 * 782 * d_inode(dentry)->i_rwsem: don't care 783 * 784 * Copy a list of attribute names into the buffer 785 * provided, or compute the buffer size required. 786 * Buffer is NULL to compute the size of the buffer required. 787 * 788 * Returns a negative error number on failure, or the number of bytes 789 * used / required on success. 790 */ 791 ssize_t 792 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 793 { 794 int ret, ret2; 795 796 down_read(&EXT4_I(d_inode(dentry))->xattr_sem); 797 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); 798 if (ret < 0) 799 goto errout; 800 if (buffer) { 801 buffer += ret; 802 buffer_size -= ret; 803 } 804 ret = ext4_xattr_block_list(dentry, buffer, buffer_size); 805 if (ret < 0) 806 goto errout; 807 ret += ret2; 808 errout: 809 up_read(&EXT4_I(d_inode(dentry))->xattr_sem); 810 return ret; 811 } 812 813 /* 814 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is 815 * not set, set it. 816 */ 817 static void ext4_xattr_update_super_block(handle_t *handle, 818 struct super_block *sb) 819 { 820 if (ext4_has_feature_xattr(sb)) 821 return; 822 823 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 824 if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh, 825 EXT4_JTR_NONE) == 0) { 826 lock_buffer(EXT4_SB(sb)->s_sbh); 827 ext4_set_feature_xattr(sb); 828 ext4_superblock_csum_set(sb); 829 unlock_buffer(EXT4_SB(sb)->s_sbh); 830 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 831 } 832 } 833 834 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 835 { 836 struct ext4_iloc iloc = { .bh = NULL }; 837 struct buffer_head *bh = NULL; 838 struct ext4_inode *raw_inode; 839 struct ext4_xattr_ibody_header *header; 840 struct ext4_xattr_entry *entry; 841 qsize_t ea_inode_refs = 0; 842 void *end; 843 int ret; 844 845 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); 846 847 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 848 ret = ext4_get_inode_loc(inode, &iloc); 849 if (ret) 850 goto out; 851 raw_inode = ext4_raw_inode(&iloc); 852 header = IHDR(inode, raw_inode); 853 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 854 ret = xattr_check_inode(inode, header, end); 855 if (ret) 856 goto out; 857 858 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); 859 entry = EXT4_XATTR_NEXT(entry)) 860 if (entry->e_value_inum) 861 ea_inode_refs++; 862 } 863 864 if (EXT4_I(inode)->i_file_acl) { 865 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 866 if (IS_ERR(bh)) { 867 ret = PTR_ERR(bh); 868 bh = NULL; 869 goto out; 870 } 871 872 ret = ext4_xattr_check_block(inode, bh); 873 if (ret) 874 goto out; 875 876 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 877 entry = EXT4_XATTR_NEXT(entry)) 878 if (entry->e_value_inum) 879 ea_inode_refs++; 880 } 881 *usage = ea_inode_refs + 1; 882 ret = 0; 883 out: 884 brelse(iloc.bh); 885 brelse(bh); 886 return ret; 887 } 888 889 static inline size_t round_up_cluster(struct inode *inode, size_t length) 890 { 891 struct super_block *sb = inode->i_sb; 892 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits + 893 inode->i_blkbits); 894 size_t mask = ~(cluster_size - 1); 895 896 return (length + cluster_size - 1) & mask; 897 } 898 899 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len) 900 { 901 int err; 902 903 err = dquot_alloc_inode(inode); 904 if (err) 905 return err; 906 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len)); 907 if (err) 908 dquot_free_inode(inode); 909 return err; 910 } 911 912 static void ext4_xattr_inode_free_quota(struct inode *parent, 913 struct inode *ea_inode, 914 size_t len) 915 { 916 if (ea_inode && 917 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) 918 return; 919 dquot_free_space_nodirty(parent, round_up_cluster(parent, len)); 920 dquot_free_inode(parent); 921 } 922 923 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, 924 struct buffer_head *block_bh, size_t value_len, 925 bool is_create) 926 { 927 int credits; 928 int blocks; 929 930 /* 931 * 1) Owner inode update 932 * 2) Ref count update on old xattr block 933 * 3) new xattr block 934 * 4) block bitmap update for new xattr block 935 * 5) group descriptor for new xattr block 936 * 6) block bitmap update for old xattr block 937 * 7) group descriptor for old block 938 * 939 * 6 & 7 can happen if we have two racing threads T_a and T_b 940 * which are each trying to set an xattr on inodes I_a and I_b 941 * which were both initially sharing an xattr block. 942 */ 943 credits = 7; 944 945 /* Quota updates. */ 946 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb); 947 948 /* 949 * In case of inline data, we may push out the data to a block, 950 * so we need to reserve credits for this eventuality 951 */ 952 if (inode && ext4_has_inline_data(inode)) 953 credits += ext4_writepage_trans_blocks(inode) + 1; 954 955 /* We are done if ea_inode feature is not enabled. */ 956 if (!ext4_has_feature_ea_inode(sb)) 957 return credits; 958 959 /* New ea_inode, inode map, block bitmap, group descriptor. */ 960 credits += 4; 961 962 /* Data blocks. */ 963 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 964 965 /* Indirection block or one level of extent tree. */ 966 blocks += 1; 967 968 /* Block bitmap and group descriptor updates for each block. */ 969 credits += blocks * 2; 970 971 /* Blocks themselves. */ 972 credits += blocks; 973 974 if (!is_create) { 975 /* Dereference ea_inode holding old xattr value. 976 * Old ea_inode, inode map, block bitmap, group descriptor. 977 */ 978 credits += 4; 979 980 /* Data blocks for old ea_inode. */ 981 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits; 982 983 /* Indirection block or one level of extent tree for old 984 * ea_inode. 985 */ 986 blocks += 1; 987 988 /* Block bitmap and group descriptor updates for each block. */ 989 credits += blocks * 2; 990 } 991 992 /* We may need to clone the existing xattr block in which case we need 993 * to increment ref counts for existing ea_inodes referenced by it. 994 */ 995 if (block_bh) { 996 struct ext4_xattr_entry *entry = BFIRST(block_bh); 997 998 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) 999 if (entry->e_value_inum) 1000 /* Ref count update on ea_inode. */ 1001 credits += 1; 1002 } 1003 return credits; 1004 } 1005 1006 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode, 1007 int ref_change) 1008 { 1009 struct ext4_iloc iloc; 1010 s64 ref_count; 1011 int ret; 1012 1013 inode_lock(ea_inode); 1014 1015 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc); 1016 if (ret) 1017 goto out; 1018 1019 ref_count = ext4_xattr_inode_get_ref(ea_inode); 1020 ref_count += ref_change; 1021 ext4_xattr_inode_set_ref(ea_inode, ref_count); 1022 1023 if (ref_change > 0) { 1024 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld", 1025 ea_inode->i_ino, ref_count); 1026 1027 if (ref_count == 1) { 1028 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u", 1029 ea_inode->i_ino, ea_inode->i_nlink); 1030 1031 set_nlink(ea_inode, 1); 1032 ext4_orphan_del(handle, ea_inode); 1033 } 1034 } else { 1035 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld", 1036 ea_inode->i_ino, ref_count); 1037 1038 if (ref_count == 0) { 1039 WARN_ONCE(ea_inode->i_nlink != 1, 1040 "EA inode %lu i_nlink=%u", 1041 ea_inode->i_ino, ea_inode->i_nlink); 1042 1043 clear_nlink(ea_inode); 1044 ext4_orphan_add(handle, ea_inode); 1045 } 1046 } 1047 1048 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc); 1049 if (ret) 1050 ext4_warning_inode(ea_inode, 1051 "ext4_mark_iloc_dirty() failed ret=%d", ret); 1052 out: 1053 inode_unlock(ea_inode); 1054 return ret; 1055 } 1056 1057 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode) 1058 { 1059 return ext4_xattr_inode_update_ref(handle, ea_inode, 1); 1060 } 1061 1062 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode) 1063 { 1064 return ext4_xattr_inode_update_ref(handle, ea_inode, -1); 1065 } 1066 1067 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent, 1068 struct ext4_xattr_entry *first) 1069 { 1070 struct inode *ea_inode; 1071 struct ext4_xattr_entry *entry; 1072 struct ext4_xattr_entry *failed_entry; 1073 unsigned int ea_ino; 1074 int err, saved_err; 1075 1076 for (entry = first; !IS_LAST_ENTRY(entry); 1077 entry = EXT4_XATTR_NEXT(entry)) { 1078 if (!entry->e_value_inum) 1079 continue; 1080 ea_ino = le32_to_cpu(entry->e_value_inum); 1081 err = ext4_xattr_inode_iget(parent, ea_ino, 1082 le32_to_cpu(entry->e_hash), 1083 &ea_inode); 1084 if (err) 1085 goto cleanup; 1086 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1087 if (err) { 1088 ext4_warning_inode(ea_inode, "inc ref error %d", err); 1089 iput(ea_inode); 1090 goto cleanup; 1091 } 1092 iput(ea_inode); 1093 } 1094 return 0; 1095 1096 cleanup: 1097 saved_err = err; 1098 failed_entry = entry; 1099 1100 for (entry = first; entry != failed_entry; 1101 entry = EXT4_XATTR_NEXT(entry)) { 1102 if (!entry->e_value_inum) 1103 continue; 1104 ea_ino = le32_to_cpu(entry->e_value_inum); 1105 err = ext4_xattr_inode_iget(parent, ea_ino, 1106 le32_to_cpu(entry->e_hash), 1107 &ea_inode); 1108 if (err) { 1109 ext4_warning(parent->i_sb, 1110 "cleanup ea_ino %u iget error %d", ea_ino, 1111 err); 1112 continue; 1113 } 1114 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1115 if (err) 1116 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", 1117 err); 1118 iput(ea_inode); 1119 } 1120 return saved_err; 1121 } 1122 1123 static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode, 1124 struct buffer_head *bh, bool block_csum, bool dirty) 1125 { 1126 int error; 1127 1128 if (bh && dirty) { 1129 if (block_csum) 1130 ext4_xattr_block_csum_set(inode, bh); 1131 error = ext4_handle_dirty_metadata(handle, NULL, bh); 1132 if (error) { 1133 ext4_warning(inode->i_sb, "Handle metadata (error %d)", 1134 error); 1135 return error; 1136 } 1137 } 1138 return 0; 1139 } 1140 1141 static void 1142 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent, 1143 struct buffer_head *bh, 1144 struct ext4_xattr_entry *first, bool block_csum, 1145 struct ext4_xattr_inode_array **ea_inode_array, 1146 int extra_credits, bool skip_quota) 1147 { 1148 struct inode *ea_inode; 1149 struct ext4_xattr_entry *entry; 1150 bool dirty = false; 1151 unsigned int ea_ino; 1152 int err; 1153 int credits; 1154 1155 /* One credit for dec ref on ea_inode, one for orphan list addition, */ 1156 credits = 2 + extra_credits; 1157 1158 for (entry = first; !IS_LAST_ENTRY(entry); 1159 entry = EXT4_XATTR_NEXT(entry)) { 1160 if (!entry->e_value_inum) 1161 continue; 1162 ea_ino = le32_to_cpu(entry->e_value_inum); 1163 err = ext4_xattr_inode_iget(parent, ea_ino, 1164 le32_to_cpu(entry->e_hash), 1165 &ea_inode); 1166 if (err) 1167 continue; 1168 1169 err = ext4_expand_inode_array(ea_inode_array, ea_inode); 1170 if (err) { 1171 ext4_warning_inode(ea_inode, 1172 "Expand inode array err=%d", err); 1173 iput(ea_inode); 1174 continue; 1175 } 1176 1177 err = ext4_journal_ensure_credits_fn(handle, credits, credits, 1178 ext4_free_metadata_revoke_credits(parent->i_sb, 1), 1179 ext4_xattr_restart_fn(handle, parent, bh, block_csum, 1180 dirty)); 1181 if (err < 0) { 1182 ext4_warning_inode(ea_inode, "Ensure credits err=%d", 1183 err); 1184 continue; 1185 } 1186 if (err > 0) { 1187 err = ext4_journal_get_write_access(handle, 1188 parent->i_sb, bh, EXT4_JTR_NONE); 1189 if (err) { 1190 ext4_warning_inode(ea_inode, 1191 "Re-get write access err=%d", 1192 err); 1193 continue; 1194 } 1195 } 1196 1197 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1198 if (err) { 1199 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d", 1200 err); 1201 continue; 1202 } 1203 1204 if (!skip_quota) 1205 ext4_xattr_inode_free_quota(parent, ea_inode, 1206 le32_to_cpu(entry->e_value_size)); 1207 1208 /* 1209 * Forget about ea_inode within the same transaction that 1210 * decrements the ref count. This avoids duplicate decrements in 1211 * case the rest of the work spills over to subsequent 1212 * transactions. 1213 */ 1214 entry->e_value_inum = 0; 1215 entry->e_value_size = 0; 1216 1217 dirty = true; 1218 } 1219 1220 if (dirty) { 1221 /* 1222 * Note that we are deliberately skipping csum calculation for 1223 * the final update because we do not expect any journal 1224 * restarts until xattr block is freed. 1225 */ 1226 1227 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1228 if (err) 1229 ext4_warning_inode(parent, 1230 "handle dirty metadata err=%d", err); 1231 } 1232 } 1233 1234 /* 1235 * Release the xattr block BH: If the reference count is > 1, decrement it; 1236 * otherwise free the block. 1237 */ 1238 static void 1239 ext4_xattr_release_block(handle_t *handle, struct inode *inode, 1240 struct buffer_head *bh, 1241 struct ext4_xattr_inode_array **ea_inode_array, 1242 int extra_credits) 1243 { 1244 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1245 u32 hash, ref; 1246 int error = 0; 1247 1248 BUFFER_TRACE(bh, "get_write_access"); 1249 error = ext4_journal_get_write_access(handle, inode->i_sb, bh, 1250 EXT4_JTR_NONE); 1251 if (error) 1252 goto out; 1253 1254 retry_ref: 1255 lock_buffer(bh); 1256 hash = le32_to_cpu(BHDR(bh)->h_hash); 1257 ref = le32_to_cpu(BHDR(bh)->h_refcount); 1258 if (ref == 1) { 1259 ea_bdebug(bh, "refcount now=0; freeing"); 1260 /* 1261 * This must happen under buffer lock for 1262 * ext4_xattr_block_set() to reliably detect freed block 1263 */ 1264 if (ea_block_cache) { 1265 struct mb_cache_entry *oe; 1266 1267 oe = mb_cache_entry_delete_or_get(ea_block_cache, hash, 1268 bh->b_blocknr); 1269 if (oe) { 1270 unlock_buffer(bh); 1271 mb_cache_entry_wait_unused(oe); 1272 mb_cache_entry_put(ea_block_cache, oe); 1273 goto retry_ref; 1274 } 1275 } 1276 get_bh(bh); 1277 unlock_buffer(bh); 1278 1279 if (ext4_has_feature_ea_inode(inode->i_sb)) 1280 ext4_xattr_inode_dec_ref_all(handle, inode, bh, 1281 BFIRST(bh), 1282 true /* block_csum */, 1283 ea_inode_array, 1284 extra_credits, 1285 true /* skip_quota */); 1286 ext4_free_blocks(handle, inode, bh, 0, 1, 1287 EXT4_FREE_BLOCKS_METADATA | 1288 EXT4_FREE_BLOCKS_FORGET); 1289 } else { 1290 ref--; 1291 BHDR(bh)->h_refcount = cpu_to_le32(ref); 1292 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) { 1293 struct mb_cache_entry *ce; 1294 1295 if (ea_block_cache) { 1296 ce = mb_cache_entry_get(ea_block_cache, hash, 1297 bh->b_blocknr); 1298 if (ce) { 1299 set_bit(MBE_REUSABLE_B, &ce->e_flags); 1300 mb_cache_entry_put(ea_block_cache, ce); 1301 } 1302 } 1303 } 1304 1305 ext4_xattr_block_csum_set(inode, bh); 1306 /* 1307 * Beware of this ugliness: Releasing of xattr block references 1308 * from different inodes can race and so we have to protect 1309 * from a race where someone else frees the block (and releases 1310 * its journal_head) before we are done dirtying the buffer. In 1311 * nojournal mode this race is harmless and we actually cannot 1312 * call ext4_handle_dirty_metadata() with locked buffer as 1313 * that function can call sync_dirty_buffer() so for that case 1314 * we handle the dirtying after unlocking the buffer. 1315 */ 1316 if (ext4_handle_valid(handle)) 1317 error = ext4_handle_dirty_metadata(handle, inode, bh); 1318 unlock_buffer(bh); 1319 if (!ext4_handle_valid(handle)) 1320 error = ext4_handle_dirty_metadata(handle, inode, bh); 1321 if (IS_SYNC(inode)) 1322 ext4_handle_sync(handle); 1323 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); 1324 ea_bdebug(bh, "refcount now=%d; releasing", 1325 le32_to_cpu(BHDR(bh)->h_refcount)); 1326 } 1327 out: 1328 ext4_std_error(inode->i_sb, error); 1329 return; 1330 } 1331 1332 /* 1333 * Find the available free space for EAs. This also returns the total number of 1334 * bytes used by EA entries. 1335 */ 1336 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, 1337 size_t *min_offs, void *base, int *total) 1338 { 1339 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1340 if (!last->e_value_inum && last->e_value_size) { 1341 size_t offs = le16_to_cpu(last->e_value_offs); 1342 if (offs < *min_offs) 1343 *min_offs = offs; 1344 } 1345 if (total) 1346 *total += EXT4_XATTR_LEN(last->e_name_len); 1347 } 1348 return (*min_offs - ((void *)last - base) - sizeof(__u32)); 1349 } 1350 1351 /* 1352 * Write the value of the EA in an inode. 1353 */ 1354 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode, 1355 const void *buf, int bufsize) 1356 { 1357 struct buffer_head *bh = NULL; 1358 unsigned long block = 0; 1359 int blocksize = ea_inode->i_sb->s_blocksize; 1360 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits; 1361 int csize, wsize = 0; 1362 int ret = 0, ret2 = 0; 1363 int retries = 0; 1364 1365 retry: 1366 while (ret >= 0 && ret < max_blocks) { 1367 struct ext4_map_blocks map; 1368 map.m_lblk = block += ret; 1369 map.m_len = max_blocks -= ret; 1370 1371 ret = ext4_map_blocks(handle, ea_inode, &map, 1372 EXT4_GET_BLOCKS_CREATE); 1373 if (ret <= 0) { 1374 ext4_mark_inode_dirty(handle, ea_inode); 1375 if (ret == -ENOSPC && 1376 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) { 1377 ret = 0; 1378 goto retry; 1379 } 1380 break; 1381 } 1382 } 1383 1384 if (ret < 0) 1385 return ret; 1386 1387 block = 0; 1388 while (wsize < bufsize) { 1389 brelse(bh); 1390 csize = (bufsize - wsize) > blocksize ? blocksize : 1391 bufsize - wsize; 1392 bh = ext4_getblk(handle, ea_inode, block, 0); 1393 if (IS_ERR(bh)) 1394 return PTR_ERR(bh); 1395 if (!bh) { 1396 WARN_ON_ONCE(1); 1397 EXT4_ERROR_INODE(ea_inode, 1398 "ext4_getblk() return bh = NULL"); 1399 return -EFSCORRUPTED; 1400 } 1401 ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh, 1402 EXT4_JTR_NONE); 1403 if (ret) 1404 goto out; 1405 1406 memcpy(bh->b_data, buf, csize); 1407 set_buffer_uptodate(bh); 1408 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1409 1410 buf += csize; 1411 wsize += csize; 1412 block += 1; 1413 } 1414 1415 inode_lock(ea_inode); 1416 i_size_write(ea_inode, wsize); 1417 ext4_update_i_disksize(ea_inode, wsize); 1418 inode_unlock(ea_inode); 1419 1420 ret2 = ext4_mark_inode_dirty(handle, ea_inode); 1421 if (unlikely(ret2 && !ret)) 1422 ret = ret2; 1423 1424 out: 1425 brelse(bh); 1426 1427 return ret; 1428 } 1429 1430 /* 1431 * Create an inode to store the value of a large EA. 1432 */ 1433 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1434 struct inode *inode, u32 hash) 1435 { 1436 struct inode *ea_inode = NULL; 1437 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1438 int err; 1439 1440 /* 1441 * Let the next inode be the goal, so we try and allocate the EA inode 1442 * in the same group, or nearby one. 1443 */ 1444 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1445 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1446 EXT4_EA_INODE_FL); 1447 if (!IS_ERR(ea_inode)) { 1448 ea_inode->i_op = &ext4_file_inode_operations; 1449 ea_inode->i_fop = &ext4_file_operations; 1450 ext4_set_aops(ea_inode); 1451 ext4_xattr_inode_set_class(ea_inode); 1452 unlock_new_inode(ea_inode); 1453 ext4_xattr_inode_set_ref(ea_inode, 1); 1454 ext4_xattr_inode_set_hash(ea_inode, hash); 1455 err = ext4_mark_inode_dirty(handle, ea_inode); 1456 if (!err) 1457 err = ext4_inode_attach_jinode(ea_inode); 1458 if (err) { 1459 if (ext4_xattr_inode_dec_ref(handle, ea_inode)) 1460 ext4_warning_inode(ea_inode, 1461 "cleanup dec ref error %d", err); 1462 iput(ea_inode); 1463 return ERR_PTR(err); 1464 } 1465 1466 /* 1467 * Xattr inodes are shared therefore quota charging is performed 1468 * at a higher level. 1469 */ 1470 dquot_free_inode(ea_inode); 1471 dquot_drop(ea_inode); 1472 inode_lock(ea_inode); 1473 ea_inode->i_flags |= S_NOQUOTA; 1474 inode_unlock(ea_inode); 1475 } 1476 1477 return ea_inode; 1478 } 1479 1480 static struct inode * 1481 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1482 size_t value_len, u32 hash) 1483 { 1484 struct inode *ea_inode; 1485 struct mb_cache_entry *ce; 1486 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1487 void *ea_data; 1488 1489 if (!ea_inode_cache) 1490 return NULL; 1491 1492 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1493 if (!ce) 1494 return NULL; 1495 1496 WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) && 1497 !(current->flags & PF_MEMALLOC_NOFS)); 1498 1499 ea_data = kvmalloc(value_len, GFP_KERNEL); 1500 if (!ea_data) { 1501 mb_cache_entry_put(ea_inode_cache, ce); 1502 return NULL; 1503 } 1504 1505 while (ce) { 1506 ea_inode = ext4_iget(inode->i_sb, ce->e_value, 1507 EXT4_IGET_NORMAL); 1508 if (!IS_ERR(ea_inode) && 1509 !is_bad_inode(ea_inode) && 1510 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1511 i_size_read(ea_inode) == value_len && 1512 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1513 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1514 value_len) && 1515 !memcmp(value, ea_data, value_len)) { 1516 mb_cache_entry_touch(ea_inode_cache, ce); 1517 mb_cache_entry_put(ea_inode_cache, ce); 1518 kvfree(ea_data); 1519 return ea_inode; 1520 } 1521 1522 if (!IS_ERR(ea_inode)) 1523 iput(ea_inode); 1524 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1525 } 1526 kvfree(ea_data); 1527 return NULL; 1528 } 1529 1530 /* 1531 * Add value of the EA in an inode. 1532 */ 1533 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1534 const void *value, size_t value_len, 1535 struct inode **ret_inode) 1536 { 1537 struct inode *ea_inode; 1538 u32 hash; 1539 int err; 1540 1541 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1542 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1543 if (ea_inode) { 1544 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1545 if (err) { 1546 iput(ea_inode); 1547 return err; 1548 } 1549 1550 *ret_inode = ea_inode; 1551 return 0; 1552 } 1553 1554 /* Create an inode for the EA value */ 1555 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1556 if (IS_ERR(ea_inode)) 1557 return PTR_ERR(ea_inode); 1558 1559 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1560 if (err) { 1561 if (ext4_xattr_inode_dec_ref(handle, ea_inode)) 1562 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err); 1563 iput(ea_inode); 1564 return err; 1565 } 1566 1567 if (EA_INODE_CACHE(inode)) 1568 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1569 ea_inode->i_ino, true /* reusable */); 1570 1571 *ret_inode = ea_inode; 1572 return 0; 1573 } 1574 1575 /* 1576 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1577 * feature is enabled. 1578 */ 1579 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1580 1581 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1582 struct ext4_xattr_search *s, 1583 handle_t *handle, struct inode *inode, 1584 bool is_block) 1585 { 1586 struct ext4_xattr_entry *last, *next; 1587 struct ext4_xattr_entry *here = s->here; 1588 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1589 int in_inode = i->in_inode; 1590 struct inode *old_ea_inode = NULL; 1591 struct inode *new_ea_inode = NULL; 1592 size_t old_size, new_size; 1593 int ret; 1594 1595 /* Space used by old and new values. */ 1596 old_size = (!s->not_found && !here->e_value_inum) ? 1597 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1598 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1599 1600 /* 1601 * Optimization for the simple case when old and new values have the 1602 * same padded sizes. Not applicable if external inodes are involved. 1603 */ 1604 if (new_size && new_size == old_size) { 1605 size_t offs = le16_to_cpu(here->e_value_offs); 1606 void *val = s->base + offs; 1607 1608 here->e_value_size = cpu_to_le32(i->value_len); 1609 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1610 memset(val, 0, new_size); 1611 } else { 1612 memcpy(val, i->value, i->value_len); 1613 /* Clear padding bytes. */ 1614 memset(val + i->value_len, 0, new_size - i->value_len); 1615 } 1616 goto update_hash; 1617 } 1618 1619 /* Compute min_offs and last. */ 1620 last = s->first; 1621 for (; !IS_LAST_ENTRY(last); last = next) { 1622 next = EXT4_XATTR_NEXT(last); 1623 if ((void *)next >= s->end) { 1624 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 1625 ret = -EFSCORRUPTED; 1626 goto out; 1627 } 1628 if (!last->e_value_inum && last->e_value_size) { 1629 size_t offs = le16_to_cpu(last->e_value_offs); 1630 if (offs < min_offs) 1631 min_offs = offs; 1632 } 1633 } 1634 1635 /* Check whether we have enough space. */ 1636 if (i->value) { 1637 size_t free; 1638 1639 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1640 if (!s->not_found) 1641 free += EXT4_XATTR_LEN(name_len) + old_size; 1642 1643 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1644 ret = -ENOSPC; 1645 goto out; 1646 } 1647 1648 /* 1649 * If storing the value in an external inode is an option, 1650 * reserve space for xattr entries/names in the external 1651 * attribute block so that a long value does not occupy the 1652 * whole space and prevent further entries being added. 1653 */ 1654 if (ext4_has_feature_ea_inode(inode->i_sb) && 1655 new_size && is_block && 1656 (min_offs + old_size - new_size) < 1657 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1658 ret = -ENOSPC; 1659 goto out; 1660 } 1661 } 1662 1663 /* 1664 * Getting access to old and new ea inodes is subject to failures. 1665 * Finish that work before doing any modifications to the xattr data. 1666 */ 1667 if (!s->not_found && here->e_value_inum) { 1668 ret = ext4_xattr_inode_iget(inode, 1669 le32_to_cpu(here->e_value_inum), 1670 le32_to_cpu(here->e_hash), 1671 &old_ea_inode); 1672 if (ret) { 1673 old_ea_inode = NULL; 1674 goto out; 1675 } 1676 } 1677 if (i->value && in_inode) { 1678 WARN_ON_ONCE(!i->value_len); 1679 1680 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1681 if (ret) 1682 goto out; 1683 1684 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1685 i->value_len, 1686 &new_ea_inode); 1687 if (ret) { 1688 new_ea_inode = NULL; 1689 ext4_xattr_inode_free_quota(inode, NULL, i->value_len); 1690 goto out; 1691 } 1692 } 1693 1694 if (old_ea_inode) { 1695 /* We are ready to release ref count on the old_ea_inode. */ 1696 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1697 if (ret) { 1698 /* Release newly required ref count on new_ea_inode. */ 1699 if (new_ea_inode) { 1700 int err; 1701 1702 err = ext4_xattr_inode_dec_ref(handle, 1703 new_ea_inode); 1704 if (err) 1705 ext4_warning_inode(new_ea_inode, 1706 "dec ref new_ea_inode err=%d", 1707 err); 1708 ext4_xattr_inode_free_quota(inode, new_ea_inode, 1709 i->value_len); 1710 } 1711 goto out; 1712 } 1713 1714 ext4_xattr_inode_free_quota(inode, old_ea_inode, 1715 le32_to_cpu(here->e_value_size)); 1716 } 1717 1718 /* No failures allowed past this point. */ 1719 1720 if (!s->not_found && here->e_value_size && !here->e_value_inum) { 1721 /* Remove the old value. */ 1722 void *first_val = s->base + min_offs; 1723 size_t offs = le16_to_cpu(here->e_value_offs); 1724 void *val = s->base + offs; 1725 1726 memmove(first_val + old_size, first_val, val - first_val); 1727 memset(first_val, 0, old_size); 1728 min_offs += old_size; 1729 1730 /* Adjust all value offsets. */ 1731 last = s->first; 1732 while (!IS_LAST_ENTRY(last)) { 1733 size_t o = le16_to_cpu(last->e_value_offs); 1734 1735 if (!last->e_value_inum && 1736 last->e_value_size && o < offs) 1737 last->e_value_offs = cpu_to_le16(o + old_size); 1738 last = EXT4_XATTR_NEXT(last); 1739 } 1740 } 1741 1742 if (!i->value) { 1743 /* Remove old name. */ 1744 size_t size = EXT4_XATTR_LEN(name_len); 1745 1746 last = ENTRY((void *)last - size); 1747 memmove(here, (void *)here + size, 1748 (void *)last - (void *)here + sizeof(__u32)); 1749 memset(last, 0, size); 1750 } else if (s->not_found) { 1751 /* Insert new name. */ 1752 size_t size = EXT4_XATTR_LEN(name_len); 1753 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1754 1755 memmove((void *)here + size, here, rest); 1756 memset(here, 0, size); 1757 here->e_name_index = i->name_index; 1758 here->e_name_len = name_len; 1759 memcpy(here->e_name, i->name, name_len); 1760 } else { 1761 /* This is an update, reset value info. */ 1762 here->e_value_inum = 0; 1763 here->e_value_offs = 0; 1764 here->e_value_size = 0; 1765 } 1766 1767 if (i->value) { 1768 /* Insert new value. */ 1769 if (in_inode) { 1770 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1771 } else if (i->value_len) { 1772 void *val = s->base + min_offs - new_size; 1773 1774 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1775 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1776 memset(val, 0, new_size); 1777 } else { 1778 memcpy(val, i->value, i->value_len); 1779 /* Clear padding bytes. */ 1780 memset(val + i->value_len, 0, 1781 new_size - i->value_len); 1782 } 1783 } 1784 here->e_value_size = cpu_to_le32(i->value_len); 1785 } 1786 1787 update_hash: 1788 if (i->value) { 1789 __le32 hash = 0; 1790 1791 /* Entry hash calculation. */ 1792 if (in_inode) { 1793 __le32 crc32c_hash; 1794 1795 /* 1796 * Feed crc32c hash instead of the raw value for entry 1797 * hash calculation. This is to avoid walking 1798 * potentially long value buffer again. 1799 */ 1800 crc32c_hash = cpu_to_le32( 1801 ext4_xattr_inode_get_hash(new_ea_inode)); 1802 hash = ext4_xattr_hash_entry(here->e_name, 1803 here->e_name_len, 1804 &crc32c_hash, 1); 1805 } else if (is_block) { 1806 __le32 *value = s->base + le16_to_cpu( 1807 here->e_value_offs); 1808 1809 hash = ext4_xattr_hash_entry(here->e_name, 1810 here->e_name_len, value, 1811 new_size >> 2); 1812 } 1813 here->e_hash = hash; 1814 } 1815 1816 if (is_block) 1817 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1818 1819 ret = 0; 1820 out: 1821 iput(old_ea_inode); 1822 iput(new_ea_inode); 1823 return ret; 1824 } 1825 1826 struct ext4_xattr_block_find { 1827 struct ext4_xattr_search s; 1828 struct buffer_head *bh; 1829 }; 1830 1831 static int 1832 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1833 struct ext4_xattr_block_find *bs) 1834 { 1835 struct super_block *sb = inode->i_sb; 1836 int error; 1837 1838 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1839 i->name_index, i->name, i->value, (long)i->value_len); 1840 1841 if (EXT4_I(inode)->i_file_acl) { 1842 /* The inode already has an extended attribute block. */ 1843 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 1844 if (IS_ERR(bs->bh)) { 1845 error = PTR_ERR(bs->bh); 1846 bs->bh = NULL; 1847 return error; 1848 } 1849 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1850 atomic_read(&(bs->bh->b_count)), 1851 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1852 error = ext4_xattr_check_block(inode, bs->bh); 1853 if (error) 1854 return error; 1855 /* Find the named attribute. */ 1856 bs->s.base = BHDR(bs->bh); 1857 bs->s.first = BFIRST(bs->bh); 1858 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1859 bs->s.here = bs->s.first; 1860 error = xattr_find_entry(inode, &bs->s.here, bs->s.end, 1861 i->name_index, i->name, 1); 1862 if (error && error != -ENODATA) 1863 return error; 1864 bs->s.not_found = error; 1865 } 1866 return 0; 1867 } 1868 1869 static int 1870 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1871 struct ext4_xattr_info *i, 1872 struct ext4_xattr_block_find *bs) 1873 { 1874 struct super_block *sb = inode->i_sb; 1875 struct buffer_head *new_bh = NULL; 1876 struct ext4_xattr_search s_copy = bs->s; 1877 struct ext4_xattr_search *s = &s_copy; 1878 struct mb_cache_entry *ce = NULL; 1879 int error = 0; 1880 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1881 struct inode *ea_inode = NULL, *tmp_inode; 1882 size_t old_ea_inode_quota = 0; 1883 unsigned int ea_ino; 1884 1885 1886 #define header(x) ((struct ext4_xattr_header *)(x)) 1887 1888 if (s->base) { 1889 int offset = (char *)s->here - bs->bh->b_data; 1890 1891 BUFFER_TRACE(bs->bh, "get_write_access"); 1892 error = ext4_journal_get_write_access(handle, sb, bs->bh, 1893 EXT4_JTR_NONE); 1894 if (error) 1895 goto cleanup; 1896 lock_buffer(bs->bh); 1897 1898 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1899 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1900 1901 /* 1902 * This must happen under buffer lock for 1903 * ext4_xattr_block_set() to reliably detect modified 1904 * block 1905 */ 1906 if (ea_block_cache) { 1907 struct mb_cache_entry *oe; 1908 1909 oe = mb_cache_entry_delete_or_get(ea_block_cache, 1910 hash, bs->bh->b_blocknr); 1911 if (oe) { 1912 /* 1913 * Xattr block is getting reused. Leave 1914 * it alone. 1915 */ 1916 mb_cache_entry_put(ea_block_cache, oe); 1917 goto clone_block; 1918 } 1919 } 1920 ea_bdebug(bs->bh, "modifying in-place"); 1921 error = ext4_xattr_set_entry(i, s, handle, inode, 1922 true /* is_block */); 1923 ext4_xattr_block_csum_set(inode, bs->bh); 1924 unlock_buffer(bs->bh); 1925 if (error == -EFSCORRUPTED) 1926 goto bad_block; 1927 if (!error) 1928 error = ext4_handle_dirty_metadata(handle, 1929 inode, 1930 bs->bh); 1931 if (error) 1932 goto cleanup; 1933 goto inserted; 1934 } 1935 clone_block: 1936 unlock_buffer(bs->bh); 1937 ea_bdebug(bs->bh, "cloning"); 1938 s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS); 1939 error = -ENOMEM; 1940 if (s->base == NULL) 1941 goto cleanup; 1942 s->first = ENTRY(header(s->base)+1); 1943 header(s->base)->h_refcount = cpu_to_le32(1); 1944 s->here = ENTRY(s->base + offset); 1945 s->end = s->base + bs->bh->b_size; 1946 1947 /* 1948 * If existing entry points to an xattr inode, we need 1949 * to prevent ext4_xattr_set_entry() from decrementing 1950 * ref count on it because the reference belongs to the 1951 * original block. In this case, make the entry look 1952 * like it has an empty value. 1953 */ 1954 if (!s->not_found && s->here->e_value_inum) { 1955 ea_ino = le32_to_cpu(s->here->e_value_inum); 1956 error = ext4_xattr_inode_iget(inode, ea_ino, 1957 le32_to_cpu(s->here->e_hash), 1958 &tmp_inode); 1959 if (error) 1960 goto cleanup; 1961 1962 if (!ext4_test_inode_state(tmp_inode, 1963 EXT4_STATE_LUSTRE_EA_INODE)) { 1964 /* 1965 * Defer quota free call for previous 1966 * inode until success is guaranteed. 1967 */ 1968 old_ea_inode_quota = le32_to_cpu( 1969 s->here->e_value_size); 1970 } 1971 iput(tmp_inode); 1972 1973 s->here->e_value_inum = 0; 1974 s->here->e_value_size = 0; 1975 } 1976 } else { 1977 /* Allocate a buffer where we construct the new block. */ 1978 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1979 error = -ENOMEM; 1980 if (s->base == NULL) 1981 goto cleanup; 1982 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1983 header(s->base)->h_blocks = cpu_to_le32(1); 1984 header(s->base)->h_refcount = cpu_to_le32(1); 1985 s->first = ENTRY(header(s->base)+1); 1986 s->here = ENTRY(header(s->base)+1); 1987 s->end = s->base + sb->s_blocksize; 1988 } 1989 1990 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1991 if (error == -EFSCORRUPTED) 1992 goto bad_block; 1993 if (error) 1994 goto cleanup; 1995 1996 if (i->value && s->here->e_value_inum) { 1997 /* 1998 * A ref count on ea_inode has been taken as part of the call to 1999 * ext4_xattr_set_entry() above. We would like to drop this 2000 * extra ref but we have to wait until the xattr block is 2001 * initialized and has its own ref count on the ea_inode. 2002 */ 2003 ea_ino = le32_to_cpu(s->here->e_value_inum); 2004 error = ext4_xattr_inode_iget(inode, ea_ino, 2005 le32_to_cpu(s->here->e_hash), 2006 &ea_inode); 2007 if (error) { 2008 ea_inode = NULL; 2009 goto cleanup; 2010 } 2011 } 2012 2013 inserted: 2014 if (!IS_LAST_ENTRY(s->first)) { 2015 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 2016 &ce); 2017 if (new_bh) { 2018 /* We found an identical block in the cache. */ 2019 if (new_bh == bs->bh) 2020 ea_bdebug(new_bh, "keeping"); 2021 else { 2022 u32 ref; 2023 2024 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2025 2026 /* The old block is released after updating 2027 the inode. */ 2028 error = dquot_alloc_block(inode, 2029 EXT4_C2B(EXT4_SB(sb), 1)); 2030 if (error) 2031 goto cleanup; 2032 BUFFER_TRACE(new_bh, "get_write_access"); 2033 error = ext4_journal_get_write_access( 2034 handle, sb, new_bh, 2035 EXT4_JTR_NONE); 2036 if (error) 2037 goto cleanup_dquot; 2038 lock_buffer(new_bh); 2039 /* 2040 * We have to be careful about races with 2041 * adding references to xattr block. Once we 2042 * hold buffer lock xattr block's state is 2043 * stable so we can check the additional 2044 * reference fits. 2045 */ 2046 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 2047 if (ref > EXT4_XATTR_REFCOUNT_MAX) { 2048 /* 2049 * Undo everything and check mbcache 2050 * again. 2051 */ 2052 unlock_buffer(new_bh); 2053 dquot_free_block(inode, 2054 EXT4_C2B(EXT4_SB(sb), 2055 1)); 2056 brelse(new_bh); 2057 mb_cache_entry_put(ea_block_cache, ce); 2058 ce = NULL; 2059 new_bh = NULL; 2060 goto inserted; 2061 } 2062 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 2063 if (ref == EXT4_XATTR_REFCOUNT_MAX) 2064 clear_bit(MBE_REUSABLE_B, &ce->e_flags); 2065 ea_bdebug(new_bh, "reusing; refcount now=%d", 2066 ref); 2067 ext4_xattr_block_csum_set(inode, new_bh); 2068 unlock_buffer(new_bh); 2069 error = ext4_handle_dirty_metadata(handle, 2070 inode, 2071 new_bh); 2072 if (error) 2073 goto cleanup_dquot; 2074 } 2075 mb_cache_entry_touch(ea_block_cache, ce); 2076 mb_cache_entry_put(ea_block_cache, ce); 2077 ce = NULL; 2078 } else if (bs->bh && s->base == bs->bh->b_data) { 2079 /* We were modifying this block in-place. */ 2080 ea_bdebug(bs->bh, "keeping this block"); 2081 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 2082 new_bh = bs->bh; 2083 get_bh(new_bh); 2084 } else { 2085 /* We need to allocate a new block */ 2086 ext4_fsblk_t goal, block; 2087 2088 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2089 2090 goal = ext4_group_first_block_no(sb, 2091 EXT4_I(inode)->i_block_group); 2092 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2093 NULL, &error); 2094 if (error) 2095 goto cleanup; 2096 2097 ea_idebug(inode, "creating block %llu", 2098 (unsigned long long)block); 2099 2100 new_bh = sb_getblk(sb, block); 2101 if (unlikely(!new_bh)) { 2102 error = -ENOMEM; 2103 getblk_failed: 2104 ext4_free_blocks(handle, inode, NULL, block, 1, 2105 EXT4_FREE_BLOCKS_METADATA); 2106 goto cleanup; 2107 } 2108 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2109 ENTRY(header(s->base)+1)); 2110 if (error) 2111 goto getblk_failed; 2112 if (ea_inode) { 2113 /* Drop the extra ref on ea_inode. */ 2114 error = ext4_xattr_inode_dec_ref(handle, 2115 ea_inode); 2116 if (error) 2117 ext4_warning_inode(ea_inode, 2118 "dec ref error=%d", 2119 error); 2120 iput(ea_inode); 2121 ea_inode = NULL; 2122 } 2123 2124 lock_buffer(new_bh); 2125 error = ext4_journal_get_create_access(handle, sb, 2126 new_bh, EXT4_JTR_NONE); 2127 if (error) { 2128 unlock_buffer(new_bh); 2129 error = -EIO; 2130 goto getblk_failed; 2131 } 2132 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2133 ext4_xattr_block_csum_set(inode, new_bh); 2134 set_buffer_uptodate(new_bh); 2135 unlock_buffer(new_bh); 2136 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2137 error = ext4_handle_dirty_metadata(handle, inode, 2138 new_bh); 2139 if (error) 2140 goto cleanup; 2141 } 2142 } 2143 2144 if (old_ea_inode_quota) 2145 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota); 2146 2147 /* Update the inode. */ 2148 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2149 2150 /* Drop the previous xattr block. */ 2151 if (bs->bh && bs->bh != new_bh) { 2152 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2153 2154 ext4_xattr_release_block(handle, inode, bs->bh, 2155 &ea_inode_array, 2156 0 /* extra_credits */); 2157 ext4_xattr_inode_array_free(ea_inode_array); 2158 } 2159 error = 0; 2160 2161 cleanup: 2162 if (ea_inode) { 2163 int error2; 2164 2165 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2166 if (error2) 2167 ext4_warning_inode(ea_inode, "dec ref error=%d", 2168 error2); 2169 2170 /* If there was an error, revert the quota charge. */ 2171 if (error) 2172 ext4_xattr_inode_free_quota(inode, ea_inode, 2173 i_size_read(ea_inode)); 2174 iput(ea_inode); 2175 } 2176 if (ce) 2177 mb_cache_entry_put(ea_block_cache, ce); 2178 brelse(new_bh); 2179 if (!(bs->bh && s->base == bs->bh->b_data)) 2180 kfree(s->base); 2181 2182 return error; 2183 2184 cleanup_dquot: 2185 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2186 goto cleanup; 2187 2188 bad_block: 2189 EXT4_ERROR_INODE(inode, "bad block %llu", 2190 EXT4_I(inode)->i_file_acl); 2191 goto cleanup; 2192 2193 #undef header 2194 } 2195 2196 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2197 struct ext4_xattr_ibody_find *is) 2198 { 2199 struct ext4_xattr_ibody_header *header; 2200 struct ext4_inode *raw_inode; 2201 int error; 2202 2203 if (!EXT4_INODE_HAS_XATTR_SPACE(inode)) 2204 return 0; 2205 2206 raw_inode = ext4_raw_inode(&is->iloc); 2207 header = IHDR(inode, raw_inode); 2208 is->s.base = is->s.first = IFIRST(header); 2209 is->s.here = is->s.first; 2210 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2211 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2212 error = xattr_check_inode(inode, header, is->s.end); 2213 if (error) 2214 return error; 2215 /* Find the named attribute. */ 2216 error = xattr_find_entry(inode, &is->s.here, is->s.end, 2217 i->name_index, i->name, 0); 2218 if (error && error != -ENODATA) 2219 return error; 2220 is->s.not_found = error; 2221 } 2222 return 0; 2223 } 2224 2225 int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2226 struct ext4_xattr_info *i, 2227 struct ext4_xattr_ibody_find *is) 2228 { 2229 struct ext4_xattr_ibody_header *header; 2230 struct ext4_xattr_search *s = &is->s; 2231 int error; 2232 2233 if (!EXT4_INODE_HAS_XATTR_SPACE(inode)) 2234 return -ENOSPC; 2235 2236 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2237 if (error) 2238 return error; 2239 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2240 if (!IS_LAST_ENTRY(s->first)) { 2241 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2242 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2243 } else { 2244 header->h_magic = cpu_to_le32(0); 2245 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2246 } 2247 return 0; 2248 } 2249 2250 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2251 struct ext4_xattr_info *i) 2252 { 2253 void *value; 2254 2255 /* When e_value_inum is set the value is stored externally. */ 2256 if (s->here->e_value_inum) 2257 return 0; 2258 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2259 return 0; 2260 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2261 return !memcmp(value, i->value, i->value_len); 2262 } 2263 2264 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2265 { 2266 struct buffer_head *bh; 2267 int error; 2268 2269 if (!EXT4_I(inode)->i_file_acl) 2270 return NULL; 2271 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2272 if (IS_ERR(bh)) 2273 return bh; 2274 error = ext4_xattr_check_block(inode, bh); 2275 if (error) { 2276 brelse(bh); 2277 return ERR_PTR(error); 2278 } 2279 return bh; 2280 } 2281 2282 /* 2283 * ext4_xattr_set_handle() 2284 * 2285 * Create, replace or remove an extended attribute for this inode. Value 2286 * is NULL to remove an existing extended attribute, and non-NULL to 2287 * either replace an existing extended attribute, or create a new extended 2288 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2289 * specify that an extended attribute must exist and must not exist 2290 * previous to the call, respectively. 2291 * 2292 * Returns 0, or a negative error number on failure. 2293 */ 2294 int 2295 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2296 const char *name, const void *value, size_t value_len, 2297 int flags) 2298 { 2299 struct ext4_xattr_info i = { 2300 .name_index = name_index, 2301 .name = name, 2302 .value = value, 2303 .value_len = value_len, 2304 .in_inode = 0, 2305 }; 2306 struct ext4_xattr_ibody_find is = { 2307 .s = { .not_found = -ENODATA, }, 2308 }; 2309 struct ext4_xattr_block_find bs = { 2310 .s = { .not_found = -ENODATA, }, 2311 }; 2312 int no_expand; 2313 int error; 2314 2315 if (!name) 2316 return -EINVAL; 2317 if (strlen(name) > 255) 2318 return -ERANGE; 2319 2320 ext4_write_lock_xattr(inode, &no_expand); 2321 2322 /* Check journal credits under write lock. */ 2323 if (ext4_handle_valid(handle)) { 2324 struct buffer_head *bh; 2325 int credits; 2326 2327 bh = ext4_xattr_get_block(inode); 2328 if (IS_ERR(bh)) { 2329 error = PTR_ERR(bh); 2330 goto cleanup; 2331 } 2332 2333 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2334 value_len, 2335 flags & XATTR_CREATE); 2336 brelse(bh); 2337 2338 if (jbd2_handle_buffer_credits(handle) < credits) { 2339 error = -ENOSPC; 2340 goto cleanup; 2341 } 2342 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS)); 2343 } 2344 2345 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2346 if (error) 2347 goto cleanup; 2348 2349 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2350 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2351 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2352 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2353 } 2354 2355 error = ext4_xattr_ibody_find(inode, &i, &is); 2356 if (error) 2357 goto cleanup; 2358 if (is.s.not_found) 2359 error = ext4_xattr_block_find(inode, &i, &bs); 2360 if (error) 2361 goto cleanup; 2362 if (is.s.not_found && bs.s.not_found) { 2363 error = -ENODATA; 2364 if (flags & XATTR_REPLACE) 2365 goto cleanup; 2366 error = 0; 2367 if (!value) 2368 goto cleanup; 2369 } else { 2370 error = -EEXIST; 2371 if (flags & XATTR_CREATE) 2372 goto cleanup; 2373 } 2374 2375 if (!value) { 2376 if (!is.s.not_found) 2377 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2378 else if (!bs.s.not_found) 2379 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2380 } else { 2381 error = 0; 2382 /* Xattr value did not change? Save us some work and bail out */ 2383 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2384 goto cleanup; 2385 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2386 goto cleanup; 2387 2388 if (ext4_has_feature_ea_inode(inode->i_sb) && 2389 (EXT4_XATTR_SIZE(i.value_len) > 2390 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2391 i.in_inode = 1; 2392 retry_inode: 2393 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2394 if (!error && !bs.s.not_found) { 2395 i.value = NULL; 2396 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2397 } else if (error == -ENOSPC) { 2398 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2399 brelse(bs.bh); 2400 bs.bh = NULL; 2401 error = ext4_xattr_block_find(inode, &i, &bs); 2402 if (error) 2403 goto cleanup; 2404 } 2405 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2406 if (!error && !is.s.not_found) { 2407 i.value = NULL; 2408 error = ext4_xattr_ibody_set(handle, inode, &i, 2409 &is); 2410 } else if (error == -ENOSPC) { 2411 /* 2412 * Xattr does not fit in the block, store at 2413 * external inode if possible. 2414 */ 2415 if (ext4_has_feature_ea_inode(inode->i_sb) && 2416 i.value_len && !i.in_inode) { 2417 i.in_inode = 1; 2418 goto retry_inode; 2419 } 2420 } 2421 } 2422 } 2423 if (!error) { 2424 ext4_xattr_update_super_block(handle, inode->i_sb); 2425 inode->i_ctime = current_time(inode); 2426 inode_inc_iversion(inode); 2427 if (!value) 2428 no_expand = 0; 2429 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2430 /* 2431 * The bh is consumed by ext4_mark_iloc_dirty, even with 2432 * error != 0. 2433 */ 2434 is.iloc.bh = NULL; 2435 if (IS_SYNC(inode)) 2436 ext4_handle_sync(handle); 2437 } 2438 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle); 2439 2440 cleanup: 2441 brelse(is.iloc.bh); 2442 brelse(bs.bh); 2443 ext4_write_unlock_xattr(inode, &no_expand); 2444 return error; 2445 } 2446 2447 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2448 bool is_create, int *credits) 2449 { 2450 struct buffer_head *bh; 2451 int err; 2452 2453 *credits = 0; 2454 2455 if (!EXT4_SB(inode->i_sb)->s_journal) 2456 return 0; 2457 2458 down_read(&EXT4_I(inode)->xattr_sem); 2459 2460 bh = ext4_xattr_get_block(inode); 2461 if (IS_ERR(bh)) { 2462 err = PTR_ERR(bh); 2463 } else { 2464 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2465 value_len, is_create); 2466 brelse(bh); 2467 err = 0; 2468 } 2469 2470 up_read(&EXT4_I(inode)->xattr_sem); 2471 return err; 2472 } 2473 2474 /* 2475 * ext4_xattr_set() 2476 * 2477 * Like ext4_xattr_set_handle, but start from an inode. This extended 2478 * attribute modification is a filesystem transaction by itself. 2479 * 2480 * Returns 0, or a negative error number on failure. 2481 */ 2482 int 2483 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2484 const void *value, size_t value_len, int flags) 2485 { 2486 handle_t *handle; 2487 struct super_block *sb = inode->i_sb; 2488 int error, retries = 0; 2489 int credits; 2490 2491 error = dquot_initialize(inode); 2492 if (error) 2493 return error; 2494 2495 retry: 2496 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2497 &credits); 2498 if (error) 2499 return error; 2500 2501 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2502 if (IS_ERR(handle)) { 2503 error = PTR_ERR(handle); 2504 } else { 2505 int error2; 2506 2507 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2508 value, value_len, flags); 2509 error2 = ext4_journal_stop(handle); 2510 if (error == -ENOSPC && 2511 ext4_should_retry_alloc(sb, &retries)) 2512 goto retry; 2513 if (error == 0) 2514 error = error2; 2515 } 2516 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL); 2517 2518 return error; 2519 } 2520 2521 /* 2522 * Shift the EA entries in the inode to create space for the increased 2523 * i_extra_isize. 2524 */ 2525 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2526 int value_offs_shift, void *to, 2527 void *from, size_t n) 2528 { 2529 struct ext4_xattr_entry *last = entry; 2530 int new_offs; 2531 2532 /* We always shift xattr headers further thus offsets get lower */ 2533 BUG_ON(value_offs_shift > 0); 2534 2535 /* Adjust the value offsets of the entries */ 2536 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2537 if (!last->e_value_inum && last->e_value_size) { 2538 new_offs = le16_to_cpu(last->e_value_offs) + 2539 value_offs_shift; 2540 last->e_value_offs = cpu_to_le16(new_offs); 2541 } 2542 } 2543 /* Shift the entries by n bytes */ 2544 memmove(to, from, n); 2545 } 2546 2547 /* 2548 * Move xattr pointed to by 'entry' from inode into external xattr block 2549 */ 2550 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2551 struct ext4_inode *raw_inode, 2552 struct ext4_xattr_entry *entry) 2553 { 2554 struct ext4_xattr_ibody_find *is = NULL; 2555 struct ext4_xattr_block_find *bs = NULL; 2556 char *buffer = NULL, *b_entry_name = NULL; 2557 size_t value_size = le32_to_cpu(entry->e_value_size); 2558 struct ext4_xattr_info i = { 2559 .value = NULL, 2560 .value_len = 0, 2561 .name_index = entry->e_name_index, 2562 .in_inode = !!entry->e_value_inum, 2563 }; 2564 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2565 int error; 2566 2567 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2568 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2569 buffer = kvmalloc(value_size, GFP_NOFS); 2570 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2571 if (!is || !bs || !buffer || !b_entry_name) { 2572 error = -ENOMEM; 2573 goto out; 2574 } 2575 2576 is->s.not_found = -ENODATA; 2577 bs->s.not_found = -ENODATA; 2578 is->iloc.bh = NULL; 2579 bs->bh = NULL; 2580 2581 /* Save the entry name and the entry value */ 2582 if (entry->e_value_inum) { 2583 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2584 if (error) 2585 goto out; 2586 } else { 2587 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2588 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2589 } 2590 2591 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2592 b_entry_name[entry->e_name_len] = '\0'; 2593 i.name = b_entry_name; 2594 2595 error = ext4_get_inode_loc(inode, &is->iloc); 2596 if (error) 2597 goto out; 2598 2599 error = ext4_xattr_ibody_find(inode, &i, is); 2600 if (error) 2601 goto out; 2602 2603 /* Remove the chosen entry from the inode */ 2604 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2605 if (error) 2606 goto out; 2607 2608 i.value = buffer; 2609 i.value_len = value_size; 2610 error = ext4_xattr_block_find(inode, &i, bs); 2611 if (error) 2612 goto out; 2613 2614 /* Add entry which was removed from the inode into the block */ 2615 error = ext4_xattr_block_set(handle, inode, &i, bs); 2616 if (error) 2617 goto out; 2618 error = 0; 2619 out: 2620 kfree(b_entry_name); 2621 kvfree(buffer); 2622 if (is) 2623 brelse(is->iloc.bh); 2624 if (bs) 2625 brelse(bs->bh); 2626 kfree(is); 2627 kfree(bs); 2628 2629 return error; 2630 } 2631 2632 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2633 struct ext4_inode *raw_inode, 2634 int isize_diff, size_t ifree, 2635 size_t bfree, int *total_ino) 2636 { 2637 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2638 struct ext4_xattr_entry *small_entry; 2639 struct ext4_xattr_entry *entry; 2640 struct ext4_xattr_entry *last; 2641 unsigned int entry_size; /* EA entry size */ 2642 unsigned int total_size; /* EA entry size + value size */ 2643 unsigned int min_total_size; 2644 int error; 2645 2646 while (isize_diff > ifree) { 2647 entry = NULL; 2648 small_entry = NULL; 2649 min_total_size = ~0U; 2650 last = IFIRST(header); 2651 /* Find the entry best suited to be pushed into EA block */ 2652 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2653 /* never move system.data out of the inode */ 2654 if ((last->e_name_len == 4) && 2655 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) && 2656 !memcmp(last->e_name, "data", 4)) 2657 continue; 2658 total_size = EXT4_XATTR_LEN(last->e_name_len); 2659 if (!last->e_value_inum) 2660 total_size += EXT4_XATTR_SIZE( 2661 le32_to_cpu(last->e_value_size)); 2662 if (total_size <= bfree && 2663 total_size < min_total_size) { 2664 if (total_size + ifree < isize_diff) { 2665 small_entry = last; 2666 } else { 2667 entry = last; 2668 min_total_size = total_size; 2669 } 2670 } 2671 } 2672 2673 if (entry == NULL) { 2674 if (small_entry == NULL) 2675 return -ENOSPC; 2676 entry = small_entry; 2677 } 2678 2679 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2680 total_size = entry_size; 2681 if (!entry->e_value_inum) 2682 total_size += EXT4_XATTR_SIZE( 2683 le32_to_cpu(entry->e_value_size)); 2684 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2685 entry); 2686 if (error) 2687 return error; 2688 2689 *total_ino -= entry_size; 2690 ifree += total_size; 2691 bfree -= total_size; 2692 } 2693 2694 return 0; 2695 } 2696 2697 /* 2698 * Expand an inode by new_extra_isize bytes when EAs are present. 2699 * Returns 0 on success or negative error number on failure. 2700 */ 2701 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2702 struct ext4_inode *raw_inode, handle_t *handle) 2703 { 2704 struct ext4_xattr_ibody_header *header; 2705 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2706 static unsigned int mnt_count; 2707 size_t min_offs; 2708 size_t ifree, bfree; 2709 int total_ino; 2710 void *base, *end; 2711 int error = 0, tried_min_extra_isize = 0; 2712 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2713 int isize_diff; /* How much do we need to grow i_extra_isize */ 2714 2715 retry: 2716 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2717 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2718 return 0; 2719 2720 header = IHDR(inode, raw_inode); 2721 2722 /* 2723 * Check if enough free space is available in the inode to shift the 2724 * entries ahead by new_extra_isize. 2725 */ 2726 2727 base = IFIRST(header); 2728 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2729 min_offs = end - base; 2730 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32); 2731 2732 error = xattr_check_inode(inode, header, end); 2733 if (error) 2734 goto cleanup; 2735 2736 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2737 if (ifree >= isize_diff) 2738 goto shift; 2739 2740 /* 2741 * Enough free space isn't available in the inode, check if 2742 * EA block can hold new_extra_isize bytes. 2743 */ 2744 if (EXT4_I(inode)->i_file_acl) { 2745 struct buffer_head *bh; 2746 2747 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2748 if (IS_ERR(bh)) { 2749 error = PTR_ERR(bh); 2750 goto cleanup; 2751 } 2752 error = ext4_xattr_check_block(inode, bh); 2753 if (error) { 2754 brelse(bh); 2755 goto cleanup; 2756 } 2757 base = BHDR(bh); 2758 end = bh->b_data + bh->b_size; 2759 min_offs = end - base; 2760 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2761 NULL); 2762 brelse(bh); 2763 if (bfree + ifree < isize_diff) { 2764 if (!tried_min_extra_isize && s_min_extra_isize) { 2765 tried_min_extra_isize++; 2766 new_extra_isize = s_min_extra_isize; 2767 goto retry; 2768 } 2769 error = -ENOSPC; 2770 goto cleanup; 2771 } 2772 } else { 2773 bfree = inode->i_sb->s_blocksize; 2774 } 2775 2776 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2777 isize_diff, ifree, bfree, 2778 &total_ino); 2779 if (error) { 2780 if (error == -ENOSPC && !tried_min_extra_isize && 2781 s_min_extra_isize) { 2782 tried_min_extra_isize++; 2783 new_extra_isize = s_min_extra_isize; 2784 goto retry; 2785 } 2786 goto cleanup; 2787 } 2788 shift: 2789 /* Adjust the offsets and shift the remaining entries ahead */ 2790 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2791 - new_extra_isize, (void *)raw_inode + 2792 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2793 (void *)header, total_ino); 2794 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2795 2796 cleanup: 2797 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2798 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2799 inode->i_ino); 2800 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2801 } 2802 return error; 2803 } 2804 2805 #define EIA_INCR 16 /* must be 2^n */ 2806 #define EIA_MASK (EIA_INCR - 1) 2807 2808 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2809 * If @ea_inode_array is new or full it will be grown and the old 2810 * contents copied over. 2811 */ 2812 static int 2813 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2814 struct inode *inode) 2815 { 2816 if (*ea_inode_array == NULL) { 2817 /* 2818 * Start with 15 inodes, so it fits into a power-of-two size. 2819 * If *ea_inode_array is NULL, this is essentially offsetof() 2820 */ 2821 (*ea_inode_array) = 2822 kmalloc(offsetof(struct ext4_xattr_inode_array, 2823 inodes[EIA_MASK]), 2824 GFP_NOFS); 2825 if (*ea_inode_array == NULL) 2826 return -ENOMEM; 2827 (*ea_inode_array)->count = 0; 2828 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2829 /* expand the array once all 15 + n * 16 slots are full */ 2830 struct ext4_xattr_inode_array *new_array = NULL; 2831 int count = (*ea_inode_array)->count; 2832 2833 /* if new_array is NULL, this is essentially offsetof() */ 2834 new_array = kmalloc( 2835 offsetof(struct ext4_xattr_inode_array, 2836 inodes[count + EIA_INCR]), 2837 GFP_NOFS); 2838 if (new_array == NULL) 2839 return -ENOMEM; 2840 memcpy(new_array, *ea_inode_array, 2841 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2842 kfree(*ea_inode_array); 2843 *ea_inode_array = new_array; 2844 } 2845 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2846 return 0; 2847 } 2848 2849 /* 2850 * ext4_xattr_delete_inode() 2851 * 2852 * Free extended attribute resources associated with this inode. Traverse 2853 * all entries and decrement reference on any xattr inodes associated with this 2854 * inode. This is called immediately before an inode is freed. We have exclusive 2855 * access to the inode. If an orphan inode is deleted it will also release its 2856 * references on xattr block and xattr inodes. 2857 */ 2858 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2859 struct ext4_xattr_inode_array **ea_inode_array, 2860 int extra_credits) 2861 { 2862 struct buffer_head *bh = NULL; 2863 struct ext4_xattr_ibody_header *header; 2864 struct ext4_iloc iloc = { .bh = NULL }; 2865 struct ext4_xattr_entry *entry; 2866 struct inode *ea_inode; 2867 int error; 2868 2869 error = ext4_journal_ensure_credits(handle, extra_credits, 2870 ext4_free_metadata_revoke_credits(inode->i_sb, 1)); 2871 if (error < 0) { 2872 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2873 goto cleanup; 2874 } 2875 2876 if (ext4_has_feature_ea_inode(inode->i_sb) && 2877 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2878 2879 error = ext4_get_inode_loc(inode, &iloc); 2880 if (error) { 2881 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2882 goto cleanup; 2883 } 2884 2885 error = ext4_journal_get_write_access(handle, inode->i_sb, 2886 iloc.bh, EXT4_JTR_NONE); 2887 if (error) { 2888 EXT4_ERROR_INODE(inode, "write access (error %d)", 2889 error); 2890 goto cleanup; 2891 } 2892 2893 header = IHDR(inode, ext4_raw_inode(&iloc)); 2894 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2895 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2896 IFIRST(header), 2897 false /* block_csum */, 2898 ea_inode_array, 2899 extra_credits, 2900 false /* skip_quota */); 2901 } 2902 2903 if (EXT4_I(inode)->i_file_acl) { 2904 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2905 if (IS_ERR(bh)) { 2906 error = PTR_ERR(bh); 2907 if (error == -EIO) { 2908 EXT4_ERROR_INODE_ERR(inode, EIO, 2909 "block %llu read error", 2910 EXT4_I(inode)->i_file_acl); 2911 } 2912 bh = NULL; 2913 goto cleanup; 2914 } 2915 error = ext4_xattr_check_block(inode, bh); 2916 if (error) 2917 goto cleanup; 2918 2919 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2920 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2921 entry = EXT4_XATTR_NEXT(entry)) { 2922 if (!entry->e_value_inum) 2923 continue; 2924 error = ext4_xattr_inode_iget(inode, 2925 le32_to_cpu(entry->e_value_inum), 2926 le32_to_cpu(entry->e_hash), 2927 &ea_inode); 2928 if (error) 2929 continue; 2930 ext4_xattr_inode_free_quota(inode, ea_inode, 2931 le32_to_cpu(entry->e_value_size)); 2932 iput(ea_inode); 2933 } 2934 2935 } 2936 2937 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2938 extra_credits); 2939 /* 2940 * Update i_file_acl value in the same transaction that releases 2941 * block. 2942 */ 2943 EXT4_I(inode)->i_file_acl = 0; 2944 error = ext4_mark_inode_dirty(handle, inode); 2945 if (error) { 2946 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2947 error); 2948 goto cleanup; 2949 } 2950 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle); 2951 } 2952 error = 0; 2953 cleanup: 2954 brelse(iloc.bh); 2955 brelse(bh); 2956 return error; 2957 } 2958 2959 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2960 { 2961 int idx; 2962 2963 if (ea_inode_array == NULL) 2964 return; 2965 2966 for (idx = 0; idx < ea_inode_array->count; ++idx) 2967 iput(ea_inode_array->inodes[idx]); 2968 kfree(ea_inode_array); 2969 } 2970 2971 /* 2972 * ext4_xattr_block_cache_insert() 2973 * 2974 * Create a new entry in the extended attribute block cache, and insert 2975 * it unless such an entry is already in the cache. 2976 * 2977 * Returns 0, or a negative error number on failure. 2978 */ 2979 static void 2980 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2981 struct buffer_head *bh) 2982 { 2983 struct ext4_xattr_header *header = BHDR(bh); 2984 __u32 hash = le32_to_cpu(header->h_hash); 2985 int reusable = le32_to_cpu(header->h_refcount) < 2986 EXT4_XATTR_REFCOUNT_MAX; 2987 int error; 2988 2989 if (!ea_block_cache) 2990 return; 2991 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2992 bh->b_blocknr, reusable); 2993 if (error) { 2994 if (error == -EBUSY) 2995 ea_bdebug(bh, "already in cache"); 2996 } else 2997 ea_bdebug(bh, "inserting [%x]", (int)hash); 2998 } 2999 3000 /* 3001 * ext4_xattr_cmp() 3002 * 3003 * Compare two extended attribute blocks for equality. 3004 * 3005 * Returns 0 if the blocks are equal, 1 if they differ, and 3006 * a negative error number on errors. 3007 */ 3008 static int 3009 ext4_xattr_cmp(struct ext4_xattr_header *header1, 3010 struct ext4_xattr_header *header2) 3011 { 3012 struct ext4_xattr_entry *entry1, *entry2; 3013 3014 entry1 = ENTRY(header1+1); 3015 entry2 = ENTRY(header2+1); 3016 while (!IS_LAST_ENTRY(entry1)) { 3017 if (IS_LAST_ENTRY(entry2)) 3018 return 1; 3019 if (entry1->e_hash != entry2->e_hash || 3020 entry1->e_name_index != entry2->e_name_index || 3021 entry1->e_name_len != entry2->e_name_len || 3022 entry1->e_value_size != entry2->e_value_size || 3023 entry1->e_value_inum != entry2->e_value_inum || 3024 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 3025 return 1; 3026 if (!entry1->e_value_inum && 3027 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 3028 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 3029 le32_to_cpu(entry1->e_value_size))) 3030 return 1; 3031 3032 entry1 = EXT4_XATTR_NEXT(entry1); 3033 entry2 = EXT4_XATTR_NEXT(entry2); 3034 } 3035 if (!IS_LAST_ENTRY(entry2)) 3036 return 1; 3037 return 0; 3038 } 3039 3040 /* 3041 * ext4_xattr_block_cache_find() 3042 * 3043 * Find an identical extended attribute block. 3044 * 3045 * Returns a pointer to the block found, or NULL if such a block was 3046 * not found or an error occurred. 3047 */ 3048 static struct buffer_head * 3049 ext4_xattr_block_cache_find(struct inode *inode, 3050 struct ext4_xattr_header *header, 3051 struct mb_cache_entry **pce) 3052 { 3053 __u32 hash = le32_to_cpu(header->h_hash); 3054 struct mb_cache_entry *ce; 3055 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 3056 3057 if (!ea_block_cache) 3058 return NULL; 3059 if (!header->h_hash) 3060 return NULL; /* never share */ 3061 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 3062 ce = mb_cache_entry_find_first(ea_block_cache, hash); 3063 while (ce) { 3064 struct buffer_head *bh; 3065 3066 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO); 3067 if (IS_ERR(bh)) { 3068 if (PTR_ERR(bh) == -ENOMEM) 3069 return NULL; 3070 bh = NULL; 3071 EXT4_ERROR_INODE(inode, "block %lu read error", 3072 (unsigned long)ce->e_value); 3073 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 3074 *pce = ce; 3075 return bh; 3076 } 3077 brelse(bh); 3078 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3079 } 3080 return NULL; 3081 } 3082 3083 #define NAME_HASH_SHIFT 5 3084 #define VALUE_HASH_SHIFT 16 3085 3086 /* 3087 * ext4_xattr_hash_entry() 3088 * 3089 * Compute the hash of an extended attribute. 3090 */ 3091 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3092 size_t value_count) 3093 { 3094 __u32 hash = 0; 3095 3096 while (name_len--) { 3097 hash = (hash << NAME_HASH_SHIFT) ^ 3098 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3099 *name++; 3100 } 3101 while (value_count--) { 3102 hash = (hash << VALUE_HASH_SHIFT) ^ 3103 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3104 le32_to_cpu(*value++); 3105 } 3106 return cpu_to_le32(hash); 3107 } 3108 3109 /* 3110 * ext4_xattr_hash_entry_signed() 3111 * 3112 * Compute the hash of an extended attribute incorrectly. 3113 */ 3114 static __le32 ext4_xattr_hash_entry_signed(char *name, size_t name_len, __le32 *value, size_t value_count) 3115 { 3116 __u32 hash = 0; 3117 3118 while (name_len--) { 3119 hash = (hash << NAME_HASH_SHIFT) ^ 3120 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3121 (signed char)*name++; 3122 } 3123 while (value_count--) { 3124 hash = (hash << VALUE_HASH_SHIFT) ^ 3125 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3126 le32_to_cpu(*value++); 3127 } 3128 return cpu_to_le32(hash); 3129 } 3130 3131 #undef NAME_HASH_SHIFT 3132 #undef VALUE_HASH_SHIFT 3133 3134 #define BLOCK_HASH_SHIFT 16 3135 3136 /* 3137 * ext4_xattr_rehash() 3138 * 3139 * Re-compute the extended attribute hash value after an entry has changed. 3140 */ 3141 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3142 { 3143 struct ext4_xattr_entry *here; 3144 __u32 hash = 0; 3145 3146 here = ENTRY(header+1); 3147 while (!IS_LAST_ENTRY(here)) { 3148 if (!here->e_hash) { 3149 /* Block is not shared if an entry's hash value == 0 */ 3150 hash = 0; 3151 break; 3152 } 3153 hash = (hash << BLOCK_HASH_SHIFT) ^ 3154 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3155 le32_to_cpu(here->e_hash); 3156 here = EXT4_XATTR_NEXT(here); 3157 } 3158 header->h_hash = cpu_to_le32(hash); 3159 } 3160 3161 #undef BLOCK_HASH_SHIFT 3162 3163 #define HASH_BUCKET_BITS 10 3164 3165 struct mb_cache * 3166 ext4_xattr_create_cache(void) 3167 { 3168 return mb_cache_create(HASH_BUCKET_BITS); 3169 } 3170 3171 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3172 { 3173 if (cache) 3174 mb_cache_destroy(cache); 3175 } 3176 3177