1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext4/xattr.c 4 * 5 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 6 * 7 * Fix by Harrison Xing <harrison@mountainviewdata.com>. 8 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>. 9 * Extended attributes for symlinks and special files added per 10 * suggestion of Luka Renko <luka.renko@hermes.si>. 11 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, 12 * Red Hat Inc. 13 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz 14 * and Andreas Gruenbacher <agruen@suse.de>. 15 */ 16 17 /* 18 * Extended attributes are stored directly in inodes (on file systems with 19 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl 20 * field contains the block number if an inode uses an additional block. All 21 * attributes must fit in the inode and one additional block. Blocks that 22 * contain the identical set of attributes may be shared among several inodes. 23 * Identical blocks are detected by keeping a cache of blocks that have 24 * recently been accessed. 25 * 26 * The attributes in inodes and on blocks have a different header; the entries 27 * are stored in the same format: 28 * 29 * +------------------+ 30 * | header | 31 * | entry 1 | | 32 * | entry 2 | | growing downwards 33 * | entry 3 | v 34 * | four null bytes | 35 * | . . . | 36 * | value 1 | ^ 37 * | value 3 | | growing upwards 38 * | value 2 | | 39 * +------------------+ 40 * 41 * The header is followed by multiple entry descriptors. In disk blocks, the 42 * entry descriptors are kept sorted. In inodes, they are unsorted. The 43 * attribute values are aligned to the end of the block in no specific order. 44 * 45 * Locking strategy 46 * ---------------- 47 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem. 48 * EA blocks are only changed if they are exclusive to an inode, so 49 * holding xattr_sem also means that nothing but the EA block's reference 50 * count can change. Multiple writers to the same block are synchronized 51 * by the buffer lock. 52 */ 53 54 #include <linux/init.h> 55 #include <linux/fs.h> 56 #include <linux/slab.h> 57 #include <linux/mbcache.h> 58 #include <linux/quotaops.h> 59 #include <linux/iversion.h> 60 #include "ext4_jbd2.h" 61 #include "ext4.h" 62 #include "xattr.h" 63 #include "acl.h" 64 65 #ifdef EXT4_XATTR_DEBUG 66 # define ea_idebug(inode, fmt, ...) \ 67 printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \ 68 inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__) 69 # define ea_bdebug(bh, fmt, ...) \ 70 printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \ 71 bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__) 72 #else 73 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 74 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 75 #endif 76 77 static void ext4_xattr_block_cache_insert(struct mb_cache *, 78 struct buffer_head *); 79 static struct buffer_head * 80 ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *, 81 struct mb_cache_entry **); 82 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 83 size_t value_count); 84 static void ext4_xattr_rehash(struct ext4_xattr_header *); 85 86 static const struct xattr_handler * const ext4_xattr_handler_map[] = { 87 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, 88 #ifdef CONFIG_EXT4_FS_POSIX_ACL 89 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 90 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 91 #endif 92 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, 93 #ifdef CONFIG_EXT4_FS_SECURITY 94 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, 95 #endif 96 [EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler, 97 }; 98 99 const struct xattr_handler *ext4_xattr_handlers[] = { 100 &ext4_xattr_user_handler, 101 &ext4_xattr_trusted_handler, 102 #ifdef CONFIG_EXT4_FS_POSIX_ACL 103 &posix_acl_access_xattr_handler, 104 &posix_acl_default_xattr_handler, 105 #endif 106 #ifdef CONFIG_EXT4_FS_SECURITY 107 &ext4_xattr_security_handler, 108 #endif 109 &ext4_xattr_hurd_handler, 110 NULL 111 }; 112 113 #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ 114 inode->i_sb->s_fs_info)->s_ea_block_cache) 115 116 #define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \ 117 inode->i_sb->s_fs_info)->s_ea_inode_cache) 118 119 static int 120 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 121 struct inode *inode); 122 123 #ifdef CONFIG_LOCKDEP 124 void ext4_xattr_inode_set_class(struct inode *ea_inode) 125 { 126 lockdep_set_subclass(&ea_inode->i_rwsem, 1); 127 } 128 #endif 129 130 static __le32 ext4_xattr_block_csum(struct inode *inode, 131 sector_t block_nr, 132 struct ext4_xattr_header *hdr) 133 { 134 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 135 __u32 csum; 136 __le64 dsk_block_nr = cpu_to_le64(block_nr); 137 __u32 dummy_csum = 0; 138 int offset = offsetof(struct ext4_xattr_header, h_checksum); 139 140 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr, 141 sizeof(dsk_block_nr)); 142 csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset); 143 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 144 offset += sizeof(dummy_csum); 145 csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset, 146 EXT4_BLOCK_SIZE(inode->i_sb) - offset); 147 148 return cpu_to_le32(csum); 149 } 150 151 static int ext4_xattr_block_csum_verify(struct inode *inode, 152 struct buffer_head *bh) 153 { 154 struct ext4_xattr_header *hdr = BHDR(bh); 155 int ret = 1; 156 157 if (ext4_has_metadata_csum(inode->i_sb)) { 158 lock_buffer(bh); 159 ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, 160 bh->b_blocknr, hdr)); 161 unlock_buffer(bh); 162 } 163 return ret; 164 } 165 166 static void ext4_xattr_block_csum_set(struct inode *inode, 167 struct buffer_head *bh) 168 { 169 if (ext4_has_metadata_csum(inode->i_sb)) 170 BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, 171 bh->b_blocknr, BHDR(bh)); 172 } 173 174 static inline const struct xattr_handler * 175 ext4_xattr_handler(int name_index) 176 { 177 const struct xattr_handler *handler = NULL; 178 179 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) 180 handler = ext4_xattr_handler_map[name_index]; 181 return handler; 182 } 183 184 static int 185 ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, 186 void *value_start) 187 { 188 struct ext4_xattr_entry *e = entry; 189 190 /* Find the end of the names list */ 191 while (!IS_LAST_ENTRY(e)) { 192 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); 193 if ((void *)next >= end) 194 return -EFSCORRUPTED; 195 if (strnlen(e->e_name, e->e_name_len) != e->e_name_len) 196 return -EFSCORRUPTED; 197 e = next; 198 } 199 200 /* Check the values */ 201 while (!IS_LAST_ENTRY(entry)) { 202 u32 size = le32_to_cpu(entry->e_value_size); 203 204 if (size > EXT4_XATTR_SIZE_MAX) 205 return -EFSCORRUPTED; 206 207 if (size != 0 && entry->e_value_inum == 0) { 208 u16 offs = le16_to_cpu(entry->e_value_offs); 209 void *value; 210 211 /* 212 * The value cannot overlap the names, and the value 213 * with padding cannot extend beyond 'end'. Check both 214 * the padded and unpadded sizes, since the size may 215 * overflow to 0 when adding padding. 216 */ 217 if (offs > end - value_start) 218 return -EFSCORRUPTED; 219 value = value_start + offs; 220 if (value < (void *)e + sizeof(u32) || 221 size > end - value || 222 EXT4_XATTR_SIZE(size) > end - value) 223 return -EFSCORRUPTED; 224 } 225 entry = EXT4_XATTR_NEXT(entry); 226 } 227 228 return 0; 229 } 230 231 static inline int 232 __ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, 233 const char *function, unsigned int line) 234 { 235 int error = -EFSCORRUPTED; 236 237 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || 238 BHDR(bh)->h_blocks != cpu_to_le32(1)) 239 goto errout; 240 if (buffer_verified(bh)) 241 return 0; 242 243 error = -EFSBADCRC; 244 if (!ext4_xattr_block_csum_verify(inode, bh)) 245 goto errout; 246 error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, 247 bh->b_data); 248 errout: 249 if (error) 250 __ext4_error_inode(inode, function, line, 0, -error, 251 "corrupted xattr block %llu", 252 (unsigned long long) bh->b_blocknr); 253 else 254 set_buffer_verified(bh); 255 return error; 256 } 257 258 #define ext4_xattr_check_block(inode, bh) \ 259 __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) 260 261 262 static int 263 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, 264 void *end, const char *function, unsigned int line) 265 { 266 int error = -EFSCORRUPTED; 267 268 if (end - (void *)header < sizeof(*header) + sizeof(u32) || 269 (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC))) 270 goto errout; 271 error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header)); 272 errout: 273 if (error) 274 __ext4_error_inode(inode, function, line, 0, -error, 275 "corrupted in-inode xattr"); 276 return error; 277 } 278 279 #define xattr_check_inode(inode, header, end) \ 280 __xattr_check_inode((inode), (header), (end), __func__, __LINE__) 281 282 static int 283 xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, 284 void *end, int name_index, const char *name, int sorted) 285 { 286 struct ext4_xattr_entry *entry, *next; 287 size_t name_len; 288 int cmp = 1; 289 290 if (name == NULL) 291 return -EINVAL; 292 name_len = strlen(name); 293 for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { 294 next = EXT4_XATTR_NEXT(entry); 295 if ((void *) next >= end) { 296 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 297 return -EFSCORRUPTED; 298 } 299 cmp = name_index - entry->e_name_index; 300 if (!cmp) 301 cmp = name_len - entry->e_name_len; 302 if (!cmp) 303 cmp = memcmp(name, entry->e_name, name_len); 304 if (cmp <= 0 && (sorted || cmp == 0)) 305 break; 306 } 307 *pentry = entry; 308 return cmp ? -ENODATA : 0; 309 } 310 311 static u32 312 ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size) 313 { 314 return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size); 315 } 316 317 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode) 318 { 319 return ((u64)ea_inode->i_ctime.tv_sec << 32) | 320 (u32) inode_peek_iversion_raw(ea_inode); 321 } 322 323 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count) 324 { 325 ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32); 326 inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff); 327 } 328 329 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode) 330 { 331 return (u32)ea_inode->i_atime.tv_sec; 332 } 333 334 static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash) 335 { 336 ea_inode->i_atime.tv_sec = hash; 337 } 338 339 /* 340 * Read the EA value from an inode. 341 */ 342 static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) 343 { 344 int blocksize = 1 << ea_inode->i_blkbits; 345 int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits; 346 int tail_size = (size % blocksize) ?: blocksize; 347 struct buffer_head *bhs_inline[8]; 348 struct buffer_head **bhs = bhs_inline; 349 int i, ret; 350 351 if (bh_count > ARRAY_SIZE(bhs_inline)) { 352 bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS); 353 if (!bhs) 354 return -ENOMEM; 355 } 356 357 ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count, 358 true /* wait */, bhs); 359 if (ret) 360 goto free_bhs; 361 362 for (i = 0; i < bh_count; i++) { 363 /* There shouldn't be any holes in ea_inode. */ 364 if (!bhs[i]) { 365 ret = -EFSCORRUPTED; 366 goto put_bhs; 367 } 368 memcpy((char *)buf + blocksize * i, bhs[i]->b_data, 369 i < bh_count - 1 ? blocksize : tail_size); 370 } 371 ret = 0; 372 put_bhs: 373 for (i = 0; i < bh_count; i++) 374 brelse(bhs[i]); 375 free_bhs: 376 if (bhs != bhs_inline) 377 kfree(bhs); 378 return ret; 379 } 380 381 #define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec) 382 383 static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino, 384 u32 ea_inode_hash, struct inode **ea_inode) 385 { 386 struct inode *inode; 387 int err; 388 389 inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL); 390 if (IS_ERR(inode)) { 391 err = PTR_ERR(inode); 392 ext4_error(parent->i_sb, 393 "error while reading EA inode %lu err=%d", ea_ino, 394 err); 395 return err; 396 } 397 398 if (is_bad_inode(inode)) { 399 ext4_error(parent->i_sb, 400 "error while reading EA inode %lu is_bad_inode", 401 ea_ino); 402 err = -EIO; 403 goto error; 404 } 405 406 if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { 407 ext4_error(parent->i_sb, 408 "EA inode %lu does not have EXT4_EA_INODE_FL flag", 409 ea_ino); 410 err = -EINVAL; 411 goto error; 412 } 413 414 ext4_xattr_inode_set_class(inode); 415 416 /* 417 * Check whether this is an old Lustre-style xattr inode. Lustre 418 * implementation does not have hash validation, rather it has a 419 * backpointer from ea_inode to the parent inode. 420 */ 421 if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) && 422 EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino && 423 inode->i_generation == parent->i_generation) { 424 ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE); 425 ext4_xattr_inode_set_ref(inode, 1); 426 } else { 427 inode_lock(inode); 428 inode->i_flags |= S_NOQUOTA; 429 inode_unlock(inode); 430 } 431 432 *ea_inode = inode; 433 return 0; 434 error: 435 iput(inode); 436 return err; 437 } 438 439 /* Remove entry from mbcache when EA inode is getting evicted */ 440 void ext4_evict_ea_inode(struct inode *inode) 441 { 442 struct mb_cache_entry *oe; 443 444 if (!EA_INODE_CACHE(inode)) 445 return; 446 /* Wait for entry to get unused so that we can remove it */ 447 while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode), 448 ext4_xattr_inode_get_hash(inode), inode->i_ino))) { 449 mb_cache_entry_wait_unused(oe); 450 mb_cache_entry_put(EA_INODE_CACHE(inode), oe); 451 } 452 } 453 454 static int 455 ext4_xattr_inode_verify_hashes(struct inode *ea_inode, 456 struct ext4_xattr_entry *entry, void *buffer, 457 size_t size) 458 { 459 u32 hash; 460 461 /* Verify stored hash matches calculated hash. */ 462 hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size); 463 if (hash != ext4_xattr_inode_get_hash(ea_inode)) 464 return -EFSCORRUPTED; 465 466 if (entry) { 467 __le32 e_hash, tmp_data; 468 469 /* Verify entry hash. */ 470 tmp_data = cpu_to_le32(hash); 471 e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len, 472 &tmp_data, 1); 473 if (e_hash != entry->e_hash) 474 return -EFSCORRUPTED; 475 } 476 return 0; 477 } 478 479 /* 480 * Read xattr value from the EA inode. 481 */ 482 static int 483 ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry, 484 void *buffer, size_t size) 485 { 486 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 487 struct inode *ea_inode; 488 int err; 489 490 err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum), 491 le32_to_cpu(entry->e_hash), &ea_inode); 492 if (err) { 493 ea_inode = NULL; 494 goto out; 495 } 496 497 if (i_size_read(ea_inode) != size) { 498 ext4_warning_inode(ea_inode, 499 "ea_inode file size=%llu entry size=%zu", 500 i_size_read(ea_inode), size); 501 err = -EFSCORRUPTED; 502 goto out; 503 } 504 505 err = ext4_xattr_inode_read(ea_inode, buffer, size); 506 if (err) 507 goto out; 508 509 if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) { 510 err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer, 511 size); 512 if (err) { 513 ext4_warning_inode(ea_inode, 514 "EA inode hash validation failed"); 515 goto out; 516 } 517 518 if (ea_inode_cache) 519 mb_cache_entry_create(ea_inode_cache, GFP_NOFS, 520 ext4_xattr_inode_get_hash(ea_inode), 521 ea_inode->i_ino, true /* reusable */); 522 } 523 out: 524 iput(ea_inode); 525 return err; 526 } 527 528 static int 529 ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, 530 void *buffer, size_t buffer_size) 531 { 532 struct buffer_head *bh = NULL; 533 struct ext4_xattr_entry *entry; 534 size_t size; 535 void *end; 536 int error; 537 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 538 539 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 540 name_index, name, buffer, (long)buffer_size); 541 542 if (!EXT4_I(inode)->i_file_acl) 543 return -ENODATA; 544 ea_idebug(inode, "reading block %llu", 545 (unsigned long long)EXT4_I(inode)->i_file_acl); 546 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 547 if (IS_ERR(bh)) 548 return PTR_ERR(bh); 549 ea_bdebug(bh, "b_count=%d, refcount=%d", 550 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 551 error = ext4_xattr_check_block(inode, bh); 552 if (error) 553 goto cleanup; 554 ext4_xattr_block_cache_insert(ea_block_cache, bh); 555 entry = BFIRST(bh); 556 end = bh->b_data + bh->b_size; 557 error = xattr_find_entry(inode, &entry, end, name_index, name, 1); 558 if (error) 559 goto cleanup; 560 size = le32_to_cpu(entry->e_value_size); 561 error = -ERANGE; 562 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 563 goto cleanup; 564 if (buffer) { 565 if (size > buffer_size) 566 goto cleanup; 567 if (entry->e_value_inum) { 568 error = ext4_xattr_inode_get(inode, entry, buffer, 569 size); 570 if (error) 571 goto cleanup; 572 } else { 573 u16 offset = le16_to_cpu(entry->e_value_offs); 574 void *p = bh->b_data + offset; 575 576 if (unlikely(p + size > end)) 577 goto cleanup; 578 memcpy(buffer, p, size); 579 } 580 } 581 error = size; 582 583 cleanup: 584 brelse(bh); 585 return error; 586 } 587 588 int 589 ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 590 void *buffer, size_t buffer_size) 591 { 592 struct ext4_xattr_ibody_header *header; 593 struct ext4_xattr_entry *entry; 594 struct ext4_inode *raw_inode; 595 struct ext4_iloc iloc; 596 size_t size; 597 void *end; 598 int error; 599 600 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 601 return -ENODATA; 602 error = ext4_get_inode_loc(inode, &iloc); 603 if (error) 604 return error; 605 raw_inode = ext4_raw_inode(&iloc); 606 header = IHDR(inode, raw_inode); 607 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 608 error = xattr_check_inode(inode, header, end); 609 if (error) 610 goto cleanup; 611 entry = IFIRST(header); 612 error = xattr_find_entry(inode, &entry, end, name_index, name, 0); 613 if (error) 614 goto cleanup; 615 size = le32_to_cpu(entry->e_value_size); 616 error = -ERANGE; 617 if (unlikely(size > EXT4_XATTR_SIZE_MAX)) 618 goto cleanup; 619 if (buffer) { 620 if (size > buffer_size) 621 goto cleanup; 622 if (entry->e_value_inum) { 623 error = ext4_xattr_inode_get(inode, entry, buffer, 624 size); 625 if (error) 626 goto cleanup; 627 } else { 628 u16 offset = le16_to_cpu(entry->e_value_offs); 629 void *p = (void *)IFIRST(header) + offset; 630 631 if (unlikely(p + size > end)) 632 goto cleanup; 633 memcpy(buffer, p, size); 634 } 635 } 636 error = size; 637 638 cleanup: 639 brelse(iloc.bh); 640 return error; 641 } 642 643 /* 644 * ext4_xattr_get() 645 * 646 * Copy an extended attribute into the buffer 647 * provided, or compute the buffer size required. 648 * Buffer is NULL to compute the size of the buffer required. 649 * 650 * Returns a negative error number on failure, or the number of bytes 651 * used / required on success. 652 */ 653 int 654 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 655 void *buffer, size_t buffer_size) 656 { 657 int error; 658 659 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) 660 return -EIO; 661 662 if (strlen(name) > 255) 663 return -ERANGE; 664 665 down_read(&EXT4_I(inode)->xattr_sem); 666 error = ext4_xattr_ibody_get(inode, name_index, name, buffer, 667 buffer_size); 668 if (error == -ENODATA) 669 error = ext4_xattr_block_get(inode, name_index, name, buffer, 670 buffer_size); 671 up_read(&EXT4_I(inode)->xattr_sem); 672 return error; 673 } 674 675 static int 676 ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, 677 char *buffer, size_t buffer_size) 678 { 679 size_t rest = buffer_size; 680 681 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { 682 const struct xattr_handler *handler = 683 ext4_xattr_handler(entry->e_name_index); 684 685 if (handler && (!handler->list || handler->list(dentry))) { 686 const char *prefix = handler->prefix ?: handler->name; 687 size_t prefix_len = strlen(prefix); 688 size_t size = prefix_len + entry->e_name_len + 1; 689 690 if (buffer) { 691 if (size > rest) 692 return -ERANGE; 693 memcpy(buffer, prefix, prefix_len); 694 buffer += prefix_len; 695 memcpy(buffer, entry->e_name, entry->e_name_len); 696 buffer += entry->e_name_len; 697 *buffer++ = 0; 698 } 699 rest -= size; 700 } 701 } 702 return buffer_size - rest; /* total size */ 703 } 704 705 static int 706 ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) 707 { 708 struct inode *inode = d_inode(dentry); 709 struct buffer_head *bh = NULL; 710 int error; 711 712 ea_idebug(inode, "buffer=%p, buffer_size=%ld", 713 buffer, (long)buffer_size); 714 715 if (!EXT4_I(inode)->i_file_acl) 716 return 0; 717 ea_idebug(inode, "reading block %llu", 718 (unsigned long long)EXT4_I(inode)->i_file_acl); 719 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 720 if (IS_ERR(bh)) 721 return PTR_ERR(bh); 722 ea_bdebug(bh, "b_count=%d, refcount=%d", 723 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); 724 error = ext4_xattr_check_block(inode, bh); 725 if (error) 726 goto cleanup; 727 ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); 728 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, 729 buffer_size); 730 cleanup: 731 brelse(bh); 732 return error; 733 } 734 735 static int 736 ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 737 { 738 struct inode *inode = d_inode(dentry); 739 struct ext4_xattr_ibody_header *header; 740 struct ext4_inode *raw_inode; 741 struct ext4_iloc iloc; 742 void *end; 743 int error; 744 745 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) 746 return 0; 747 error = ext4_get_inode_loc(inode, &iloc); 748 if (error) 749 return error; 750 raw_inode = ext4_raw_inode(&iloc); 751 header = IHDR(inode, raw_inode); 752 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 753 error = xattr_check_inode(inode, header, end); 754 if (error) 755 goto cleanup; 756 error = ext4_xattr_list_entries(dentry, IFIRST(header), 757 buffer, buffer_size); 758 759 cleanup: 760 brelse(iloc.bh); 761 return error; 762 } 763 764 /* 765 * Inode operation listxattr() 766 * 767 * d_inode(dentry)->i_rwsem: don't care 768 * 769 * Copy a list of attribute names into the buffer 770 * provided, or compute the buffer size required. 771 * Buffer is NULL to compute the size of the buffer required. 772 * 773 * Returns a negative error number on failure, or the number of bytes 774 * used / required on success. 775 */ 776 ssize_t 777 ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 778 { 779 int ret, ret2; 780 781 down_read(&EXT4_I(d_inode(dentry))->xattr_sem); 782 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); 783 if (ret < 0) 784 goto errout; 785 if (buffer) { 786 buffer += ret; 787 buffer_size -= ret; 788 } 789 ret = ext4_xattr_block_list(dentry, buffer, buffer_size); 790 if (ret < 0) 791 goto errout; 792 ret += ret2; 793 errout: 794 up_read(&EXT4_I(d_inode(dentry))->xattr_sem); 795 return ret; 796 } 797 798 /* 799 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is 800 * not set, set it. 801 */ 802 static void ext4_xattr_update_super_block(handle_t *handle, 803 struct super_block *sb) 804 { 805 if (ext4_has_feature_xattr(sb)) 806 return; 807 808 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 809 if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh, 810 EXT4_JTR_NONE) == 0) { 811 lock_buffer(EXT4_SB(sb)->s_sbh); 812 ext4_set_feature_xattr(sb); 813 ext4_superblock_csum_set(sb); 814 unlock_buffer(EXT4_SB(sb)->s_sbh); 815 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 816 } 817 } 818 819 int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) 820 { 821 struct ext4_iloc iloc = { .bh = NULL }; 822 struct buffer_head *bh = NULL; 823 struct ext4_inode *raw_inode; 824 struct ext4_xattr_ibody_header *header; 825 struct ext4_xattr_entry *entry; 826 qsize_t ea_inode_refs = 0; 827 void *end; 828 int ret; 829 830 lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem); 831 832 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 833 ret = ext4_get_inode_loc(inode, &iloc); 834 if (ret) 835 goto out; 836 raw_inode = ext4_raw_inode(&iloc); 837 header = IHDR(inode, raw_inode); 838 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 839 ret = xattr_check_inode(inode, header, end); 840 if (ret) 841 goto out; 842 843 for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); 844 entry = EXT4_XATTR_NEXT(entry)) 845 if (entry->e_value_inum) 846 ea_inode_refs++; 847 } 848 849 if (EXT4_I(inode)->i_file_acl) { 850 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 851 if (IS_ERR(bh)) { 852 ret = PTR_ERR(bh); 853 bh = NULL; 854 goto out; 855 } 856 857 ret = ext4_xattr_check_block(inode, bh); 858 if (ret) 859 goto out; 860 861 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 862 entry = EXT4_XATTR_NEXT(entry)) 863 if (entry->e_value_inum) 864 ea_inode_refs++; 865 } 866 *usage = ea_inode_refs + 1; 867 ret = 0; 868 out: 869 brelse(iloc.bh); 870 brelse(bh); 871 return ret; 872 } 873 874 static inline size_t round_up_cluster(struct inode *inode, size_t length) 875 { 876 struct super_block *sb = inode->i_sb; 877 size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits + 878 inode->i_blkbits); 879 size_t mask = ~(cluster_size - 1); 880 881 return (length + cluster_size - 1) & mask; 882 } 883 884 static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len) 885 { 886 int err; 887 888 err = dquot_alloc_inode(inode); 889 if (err) 890 return err; 891 err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len)); 892 if (err) 893 dquot_free_inode(inode); 894 return err; 895 } 896 897 static void ext4_xattr_inode_free_quota(struct inode *parent, 898 struct inode *ea_inode, 899 size_t len) 900 { 901 if (ea_inode && 902 ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) 903 return; 904 dquot_free_space_nodirty(parent, round_up_cluster(parent, len)); 905 dquot_free_inode(parent); 906 } 907 908 int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, 909 struct buffer_head *block_bh, size_t value_len, 910 bool is_create) 911 { 912 int credits; 913 int blocks; 914 915 /* 916 * 1) Owner inode update 917 * 2) Ref count update on old xattr block 918 * 3) new xattr block 919 * 4) block bitmap update for new xattr block 920 * 5) group descriptor for new xattr block 921 * 6) block bitmap update for old xattr block 922 * 7) group descriptor for old block 923 * 924 * 6 & 7 can happen if we have two racing threads T_a and T_b 925 * which are each trying to set an xattr on inodes I_a and I_b 926 * which were both initially sharing an xattr block. 927 */ 928 credits = 7; 929 930 /* Quota updates. */ 931 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb); 932 933 /* 934 * In case of inline data, we may push out the data to a block, 935 * so we need to reserve credits for this eventuality 936 */ 937 if (inode && ext4_has_inline_data(inode)) 938 credits += ext4_writepage_trans_blocks(inode) + 1; 939 940 /* We are done if ea_inode feature is not enabled. */ 941 if (!ext4_has_feature_ea_inode(sb)) 942 return credits; 943 944 /* New ea_inode, inode map, block bitmap, group descriptor. */ 945 credits += 4; 946 947 /* Data blocks. */ 948 blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits; 949 950 /* Indirection block or one level of extent tree. */ 951 blocks += 1; 952 953 /* Block bitmap and group descriptor updates for each block. */ 954 credits += blocks * 2; 955 956 /* Blocks themselves. */ 957 credits += blocks; 958 959 if (!is_create) { 960 /* Dereference ea_inode holding old xattr value. 961 * Old ea_inode, inode map, block bitmap, group descriptor. 962 */ 963 credits += 4; 964 965 /* Data blocks for old ea_inode. */ 966 blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits; 967 968 /* Indirection block or one level of extent tree for old 969 * ea_inode. 970 */ 971 blocks += 1; 972 973 /* Block bitmap and group descriptor updates for each block. */ 974 credits += blocks * 2; 975 } 976 977 /* We may need to clone the existing xattr block in which case we need 978 * to increment ref counts for existing ea_inodes referenced by it. 979 */ 980 if (block_bh) { 981 struct ext4_xattr_entry *entry = BFIRST(block_bh); 982 983 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) 984 if (entry->e_value_inum) 985 /* Ref count update on ea_inode. */ 986 credits += 1; 987 } 988 return credits; 989 } 990 991 static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode, 992 int ref_change) 993 { 994 struct ext4_iloc iloc; 995 s64 ref_count; 996 int ret; 997 998 inode_lock(ea_inode); 999 1000 ret = ext4_reserve_inode_write(handle, ea_inode, &iloc); 1001 if (ret) 1002 goto out; 1003 1004 ref_count = ext4_xattr_inode_get_ref(ea_inode); 1005 ref_count += ref_change; 1006 ext4_xattr_inode_set_ref(ea_inode, ref_count); 1007 1008 if (ref_change > 0) { 1009 WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld", 1010 ea_inode->i_ino, ref_count); 1011 1012 if (ref_count == 1) { 1013 WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u", 1014 ea_inode->i_ino, ea_inode->i_nlink); 1015 1016 set_nlink(ea_inode, 1); 1017 ext4_orphan_del(handle, ea_inode); 1018 } 1019 } else { 1020 WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld", 1021 ea_inode->i_ino, ref_count); 1022 1023 if (ref_count == 0) { 1024 WARN_ONCE(ea_inode->i_nlink != 1, 1025 "EA inode %lu i_nlink=%u", 1026 ea_inode->i_ino, ea_inode->i_nlink); 1027 1028 clear_nlink(ea_inode); 1029 ext4_orphan_add(handle, ea_inode); 1030 } 1031 } 1032 1033 ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc); 1034 if (ret) 1035 ext4_warning_inode(ea_inode, 1036 "ext4_mark_iloc_dirty() failed ret=%d", ret); 1037 out: 1038 inode_unlock(ea_inode); 1039 return ret; 1040 } 1041 1042 static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode) 1043 { 1044 return ext4_xattr_inode_update_ref(handle, ea_inode, 1); 1045 } 1046 1047 static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode) 1048 { 1049 return ext4_xattr_inode_update_ref(handle, ea_inode, -1); 1050 } 1051 1052 static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent, 1053 struct ext4_xattr_entry *first) 1054 { 1055 struct inode *ea_inode; 1056 struct ext4_xattr_entry *entry; 1057 struct ext4_xattr_entry *failed_entry; 1058 unsigned int ea_ino; 1059 int err, saved_err; 1060 1061 for (entry = first; !IS_LAST_ENTRY(entry); 1062 entry = EXT4_XATTR_NEXT(entry)) { 1063 if (!entry->e_value_inum) 1064 continue; 1065 ea_ino = le32_to_cpu(entry->e_value_inum); 1066 err = ext4_xattr_inode_iget(parent, ea_ino, 1067 le32_to_cpu(entry->e_hash), 1068 &ea_inode); 1069 if (err) 1070 goto cleanup; 1071 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1072 if (err) { 1073 ext4_warning_inode(ea_inode, "inc ref error %d", err); 1074 iput(ea_inode); 1075 goto cleanup; 1076 } 1077 iput(ea_inode); 1078 } 1079 return 0; 1080 1081 cleanup: 1082 saved_err = err; 1083 failed_entry = entry; 1084 1085 for (entry = first; entry != failed_entry; 1086 entry = EXT4_XATTR_NEXT(entry)) { 1087 if (!entry->e_value_inum) 1088 continue; 1089 ea_ino = le32_to_cpu(entry->e_value_inum); 1090 err = ext4_xattr_inode_iget(parent, ea_ino, 1091 le32_to_cpu(entry->e_hash), 1092 &ea_inode); 1093 if (err) { 1094 ext4_warning(parent->i_sb, 1095 "cleanup ea_ino %u iget error %d", ea_ino, 1096 err); 1097 continue; 1098 } 1099 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1100 if (err) 1101 ext4_warning_inode(ea_inode, "cleanup dec ref error %d", 1102 err); 1103 iput(ea_inode); 1104 } 1105 return saved_err; 1106 } 1107 1108 static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode, 1109 struct buffer_head *bh, bool block_csum, bool dirty) 1110 { 1111 int error; 1112 1113 if (bh && dirty) { 1114 if (block_csum) 1115 ext4_xattr_block_csum_set(inode, bh); 1116 error = ext4_handle_dirty_metadata(handle, NULL, bh); 1117 if (error) { 1118 ext4_warning(inode->i_sb, "Handle metadata (error %d)", 1119 error); 1120 return error; 1121 } 1122 } 1123 return 0; 1124 } 1125 1126 static void 1127 ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent, 1128 struct buffer_head *bh, 1129 struct ext4_xattr_entry *first, bool block_csum, 1130 struct ext4_xattr_inode_array **ea_inode_array, 1131 int extra_credits, bool skip_quota) 1132 { 1133 struct inode *ea_inode; 1134 struct ext4_xattr_entry *entry; 1135 bool dirty = false; 1136 unsigned int ea_ino; 1137 int err; 1138 int credits; 1139 1140 /* One credit for dec ref on ea_inode, one for orphan list addition, */ 1141 credits = 2 + extra_credits; 1142 1143 for (entry = first; !IS_LAST_ENTRY(entry); 1144 entry = EXT4_XATTR_NEXT(entry)) { 1145 if (!entry->e_value_inum) 1146 continue; 1147 ea_ino = le32_to_cpu(entry->e_value_inum); 1148 err = ext4_xattr_inode_iget(parent, ea_ino, 1149 le32_to_cpu(entry->e_hash), 1150 &ea_inode); 1151 if (err) 1152 continue; 1153 1154 err = ext4_expand_inode_array(ea_inode_array, ea_inode); 1155 if (err) { 1156 ext4_warning_inode(ea_inode, 1157 "Expand inode array err=%d", err); 1158 iput(ea_inode); 1159 continue; 1160 } 1161 1162 err = ext4_journal_ensure_credits_fn(handle, credits, credits, 1163 ext4_free_metadata_revoke_credits(parent->i_sb, 1), 1164 ext4_xattr_restart_fn(handle, parent, bh, block_csum, 1165 dirty)); 1166 if (err < 0) { 1167 ext4_warning_inode(ea_inode, "Ensure credits err=%d", 1168 err); 1169 continue; 1170 } 1171 if (err > 0) { 1172 err = ext4_journal_get_write_access(handle, 1173 parent->i_sb, bh, EXT4_JTR_NONE); 1174 if (err) { 1175 ext4_warning_inode(ea_inode, 1176 "Re-get write access err=%d", 1177 err); 1178 continue; 1179 } 1180 } 1181 1182 err = ext4_xattr_inode_dec_ref(handle, ea_inode); 1183 if (err) { 1184 ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d", 1185 err); 1186 continue; 1187 } 1188 1189 if (!skip_quota) 1190 ext4_xattr_inode_free_quota(parent, ea_inode, 1191 le32_to_cpu(entry->e_value_size)); 1192 1193 /* 1194 * Forget about ea_inode within the same transaction that 1195 * decrements the ref count. This avoids duplicate decrements in 1196 * case the rest of the work spills over to subsequent 1197 * transactions. 1198 */ 1199 entry->e_value_inum = 0; 1200 entry->e_value_size = 0; 1201 1202 dirty = true; 1203 } 1204 1205 if (dirty) { 1206 /* 1207 * Note that we are deliberately skipping csum calculation for 1208 * the final update because we do not expect any journal 1209 * restarts until xattr block is freed. 1210 */ 1211 1212 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1213 if (err) 1214 ext4_warning_inode(parent, 1215 "handle dirty metadata err=%d", err); 1216 } 1217 } 1218 1219 /* 1220 * Release the xattr block BH: If the reference count is > 1, decrement it; 1221 * otherwise free the block. 1222 */ 1223 static void 1224 ext4_xattr_release_block(handle_t *handle, struct inode *inode, 1225 struct buffer_head *bh, 1226 struct ext4_xattr_inode_array **ea_inode_array, 1227 int extra_credits) 1228 { 1229 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1230 u32 hash, ref; 1231 int error = 0; 1232 1233 BUFFER_TRACE(bh, "get_write_access"); 1234 error = ext4_journal_get_write_access(handle, inode->i_sb, bh, 1235 EXT4_JTR_NONE); 1236 if (error) 1237 goto out; 1238 1239 retry_ref: 1240 lock_buffer(bh); 1241 hash = le32_to_cpu(BHDR(bh)->h_hash); 1242 ref = le32_to_cpu(BHDR(bh)->h_refcount); 1243 if (ref == 1) { 1244 ea_bdebug(bh, "refcount now=0; freeing"); 1245 /* 1246 * This must happen under buffer lock for 1247 * ext4_xattr_block_set() to reliably detect freed block 1248 */ 1249 if (ea_block_cache) { 1250 struct mb_cache_entry *oe; 1251 1252 oe = mb_cache_entry_delete_or_get(ea_block_cache, hash, 1253 bh->b_blocknr); 1254 if (oe) { 1255 unlock_buffer(bh); 1256 mb_cache_entry_wait_unused(oe); 1257 mb_cache_entry_put(ea_block_cache, oe); 1258 goto retry_ref; 1259 } 1260 } 1261 get_bh(bh); 1262 unlock_buffer(bh); 1263 1264 if (ext4_has_feature_ea_inode(inode->i_sb)) 1265 ext4_xattr_inode_dec_ref_all(handle, inode, bh, 1266 BFIRST(bh), 1267 true /* block_csum */, 1268 ea_inode_array, 1269 extra_credits, 1270 true /* skip_quota */); 1271 ext4_free_blocks(handle, inode, bh, 0, 1, 1272 EXT4_FREE_BLOCKS_METADATA | 1273 EXT4_FREE_BLOCKS_FORGET); 1274 } else { 1275 ref--; 1276 BHDR(bh)->h_refcount = cpu_to_le32(ref); 1277 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) { 1278 struct mb_cache_entry *ce; 1279 1280 if (ea_block_cache) { 1281 ce = mb_cache_entry_get(ea_block_cache, hash, 1282 bh->b_blocknr); 1283 if (ce) { 1284 ce->e_reusable = 1; 1285 mb_cache_entry_put(ea_block_cache, ce); 1286 } 1287 } 1288 } 1289 1290 ext4_xattr_block_csum_set(inode, bh); 1291 /* 1292 * Beware of this ugliness: Releasing of xattr block references 1293 * from different inodes can race and so we have to protect 1294 * from a race where someone else frees the block (and releases 1295 * its journal_head) before we are done dirtying the buffer. In 1296 * nojournal mode this race is harmless and we actually cannot 1297 * call ext4_handle_dirty_metadata() with locked buffer as 1298 * that function can call sync_dirty_buffer() so for that case 1299 * we handle the dirtying after unlocking the buffer. 1300 */ 1301 if (ext4_handle_valid(handle)) 1302 error = ext4_handle_dirty_metadata(handle, inode, bh); 1303 unlock_buffer(bh); 1304 if (!ext4_handle_valid(handle)) 1305 error = ext4_handle_dirty_metadata(handle, inode, bh); 1306 if (IS_SYNC(inode)) 1307 ext4_handle_sync(handle); 1308 dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); 1309 ea_bdebug(bh, "refcount now=%d; releasing", 1310 le32_to_cpu(BHDR(bh)->h_refcount)); 1311 } 1312 out: 1313 ext4_std_error(inode->i_sb, error); 1314 return; 1315 } 1316 1317 /* 1318 * Find the available free space for EAs. This also returns the total number of 1319 * bytes used by EA entries. 1320 */ 1321 static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, 1322 size_t *min_offs, void *base, int *total) 1323 { 1324 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 1325 if (!last->e_value_inum && last->e_value_size) { 1326 size_t offs = le16_to_cpu(last->e_value_offs); 1327 if (offs < *min_offs) 1328 *min_offs = offs; 1329 } 1330 if (total) 1331 *total += EXT4_XATTR_LEN(last->e_name_len); 1332 } 1333 return (*min_offs - ((void *)last - base) - sizeof(__u32)); 1334 } 1335 1336 /* 1337 * Write the value of the EA in an inode. 1338 */ 1339 static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode, 1340 const void *buf, int bufsize) 1341 { 1342 struct buffer_head *bh = NULL; 1343 unsigned long block = 0; 1344 int blocksize = ea_inode->i_sb->s_blocksize; 1345 int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits; 1346 int csize, wsize = 0; 1347 int ret = 0, ret2 = 0; 1348 int retries = 0; 1349 1350 retry: 1351 while (ret >= 0 && ret < max_blocks) { 1352 struct ext4_map_blocks map; 1353 map.m_lblk = block += ret; 1354 map.m_len = max_blocks -= ret; 1355 1356 ret = ext4_map_blocks(handle, ea_inode, &map, 1357 EXT4_GET_BLOCKS_CREATE); 1358 if (ret <= 0) { 1359 ext4_mark_inode_dirty(handle, ea_inode); 1360 if (ret == -ENOSPC && 1361 ext4_should_retry_alloc(ea_inode->i_sb, &retries)) { 1362 ret = 0; 1363 goto retry; 1364 } 1365 break; 1366 } 1367 } 1368 1369 if (ret < 0) 1370 return ret; 1371 1372 block = 0; 1373 while (wsize < bufsize) { 1374 brelse(bh); 1375 csize = (bufsize - wsize) > blocksize ? blocksize : 1376 bufsize - wsize; 1377 bh = ext4_getblk(handle, ea_inode, block, 0); 1378 if (IS_ERR(bh)) 1379 return PTR_ERR(bh); 1380 if (!bh) { 1381 WARN_ON_ONCE(1); 1382 EXT4_ERROR_INODE(ea_inode, 1383 "ext4_getblk() return bh = NULL"); 1384 return -EFSCORRUPTED; 1385 } 1386 ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh, 1387 EXT4_JTR_NONE); 1388 if (ret) 1389 goto out; 1390 1391 memcpy(bh->b_data, buf, csize); 1392 set_buffer_uptodate(bh); 1393 ext4_handle_dirty_metadata(handle, ea_inode, bh); 1394 1395 buf += csize; 1396 wsize += csize; 1397 block += 1; 1398 } 1399 1400 inode_lock(ea_inode); 1401 i_size_write(ea_inode, wsize); 1402 ext4_update_i_disksize(ea_inode, wsize); 1403 inode_unlock(ea_inode); 1404 1405 ret2 = ext4_mark_inode_dirty(handle, ea_inode); 1406 if (unlikely(ret2 && !ret)) 1407 ret = ret2; 1408 1409 out: 1410 brelse(bh); 1411 1412 return ret; 1413 } 1414 1415 /* 1416 * Create an inode to store the value of a large EA. 1417 */ 1418 static struct inode *ext4_xattr_inode_create(handle_t *handle, 1419 struct inode *inode, u32 hash) 1420 { 1421 struct inode *ea_inode = NULL; 1422 uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) }; 1423 int err; 1424 1425 /* 1426 * Let the next inode be the goal, so we try and allocate the EA inode 1427 * in the same group, or nearby one. 1428 */ 1429 ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, 1430 S_IFREG | 0600, NULL, inode->i_ino + 1, owner, 1431 EXT4_EA_INODE_FL); 1432 if (!IS_ERR(ea_inode)) { 1433 ea_inode->i_op = &ext4_file_inode_operations; 1434 ea_inode->i_fop = &ext4_file_operations; 1435 ext4_set_aops(ea_inode); 1436 ext4_xattr_inode_set_class(ea_inode); 1437 unlock_new_inode(ea_inode); 1438 ext4_xattr_inode_set_ref(ea_inode, 1); 1439 ext4_xattr_inode_set_hash(ea_inode, hash); 1440 err = ext4_mark_inode_dirty(handle, ea_inode); 1441 if (!err) 1442 err = ext4_inode_attach_jinode(ea_inode); 1443 if (err) { 1444 iput(ea_inode); 1445 return ERR_PTR(err); 1446 } 1447 1448 /* 1449 * Xattr inodes are shared therefore quota charging is performed 1450 * at a higher level. 1451 */ 1452 dquot_free_inode(ea_inode); 1453 dquot_drop(ea_inode); 1454 inode_lock(ea_inode); 1455 ea_inode->i_flags |= S_NOQUOTA; 1456 inode_unlock(ea_inode); 1457 } 1458 1459 return ea_inode; 1460 } 1461 1462 static struct inode * 1463 ext4_xattr_inode_cache_find(struct inode *inode, const void *value, 1464 size_t value_len, u32 hash) 1465 { 1466 struct inode *ea_inode; 1467 struct mb_cache_entry *ce; 1468 struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode); 1469 void *ea_data; 1470 1471 if (!ea_inode_cache) 1472 return NULL; 1473 1474 ce = mb_cache_entry_find_first(ea_inode_cache, hash); 1475 if (!ce) 1476 return NULL; 1477 1478 WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) && 1479 !(current->flags & PF_MEMALLOC_NOFS)); 1480 1481 ea_data = kvmalloc(value_len, GFP_KERNEL); 1482 if (!ea_data) { 1483 mb_cache_entry_put(ea_inode_cache, ce); 1484 return NULL; 1485 } 1486 1487 while (ce) { 1488 ea_inode = ext4_iget(inode->i_sb, ce->e_value, 1489 EXT4_IGET_NORMAL); 1490 if (!IS_ERR(ea_inode) && 1491 !is_bad_inode(ea_inode) && 1492 (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && 1493 i_size_read(ea_inode) == value_len && 1494 !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && 1495 !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, 1496 value_len) && 1497 !memcmp(value, ea_data, value_len)) { 1498 mb_cache_entry_touch(ea_inode_cache, ce); 1499 mb_cache_entry_put(ea_inode_cache, ce); 1500 kvfree(ea_data); 1501 return ea_inode; 1502 } 1503 1504 if (!IS_ERR(ea_inode)) 1505 iput(ea_inode); 1506 ce = mb_cache_entry_find_next(ea_inode_cache, ce); 1507 } 1508 kvfree(ea_data); 1509 return NULL; 1510 } 1511 1512 /* 1513 * Add value of the EA in an inode. 1514 */ 1515 static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode, 1516 const void *value, size_t value_len, 1517 struct inode **ret_inode) 1518 { 1519 struct inode *ea_inode; 1520 u32 hash; 1521 int err; 1522 1523 hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len); 1524 ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash); 1525 if (ea_inode) { 1526 err = ext4_xattr_inode_inc_ref(handle, ea_inode); 1527 if (err) { 1528 iput(ea_inode); 1529 return err; 1530 } 1531 1532 *ret_inode = ea_inode; 1533 return 0; 1534 } 1535 1536 /* Create an inode for the EA value */ 1537 ea_inode = ext4_xattr_inode_create(handle, inode, hash); 1538 if (IS_ERR(ea_inode)) 1539 return PTR_ERR(ea_inode); 1540 1541 err = ext4_xattr_inode_write(handle, ea_inode, value, value_len); 1542 if (err) { 1543 ext4_xattr_inode_dec_ref(handle, ea_inode); 1544 iput(ea_inode); 1545 return err; 1546 } 1547 1548 if (EA_INODE_CACHE(inode)) 1549 mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash, 1550 ea_inode->i_ino, true /* reusable */); 1551 1552 *ret_inode = ea_inode; 1553 return 0; 1554 } 1555 1556 /* 1557 * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode 1558 * feature is enabled. 1559 */ 1560 #define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U) 1561 1562 static int ext4_xattr_set_entry(struct ext4_xattr_info *i, 1563 struct ext4_xattr_search *s, 1564 handle_t *handle, struct inode *inode, 1565 bool is_block) 1566 { 1567 struct ext4_xattr_entry *last, *next; 1568 struct ext4_xattr_entry *here = s->here; 1569 size_t min_offs = s->end - s->base, name_len = strlen(i->name); 1570 int in_inode = i->in_inode; 1571 struct inode *old_ea_inode = NULL; 1572 struct inode *new_ea_inode = NULL; 1573 size_t old_size, new_size; 1574 int ret; 1575 1576 /* Space used by old and new values. */ 1577 old_size = (!s->not_found && !here->e_value_inum) ? 1578 EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0; 1579 new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0; 1580 1581 /* 1582 * Optimization for the simple case when old and new values have the 1583 * same padded sizes. Not applicable if external inodes are involved. 1584 */ 1585 if (new_size && new_size == old_size) { 1586 size_t offs = le16_to_cpu(here->e_value_offs); 1587 void *val = s->base + offs; 1588 1589 here->e_value_size = cpu_to_le32(i->value_len); 1590 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1591 memset(val, 0, new_size); 1592 } else { 1593 memcpy(val, i->value, i->value_len); 1594 /* Clear padding bytes. */ 1595 memset(val + i->value_len, 0, new_size - i->value_len); 1596 } 1597 goto update_hash; 1598 } 1599 1600 /* Compute min_offs and last. */ 1601 last = s->first; 1602 for (; !IS_LAST_ENTRY(last); last = next) { 1603 next = EXT4_XATTR_NEXT(last); 1604 if ((void *)next >= s->end) { 1605 EXT4_ERROR_INODE(inode, "corrupted xattr entries"); 1606 ret = -EFSCORRUPTED; 1607 goto out; 1608 } 1609 if (!last->e_value_inum && last->e_value_size) { 1610 size_t offs = le16_to_cpu(last->e_value_offs); 1611 if (offs < min_offs) 1612 min_offs = offs; 1613 } 1614 } 1615 1616 /* Check whether we have enough space. */ 1617 if (i->value) { 1618 size_t free; 1619 1620 free = min_offs - ((void *)last - s->base) - sizeof(__u32); 1621 if (!s->not_found) 1622 free += EXT4_XATTR_LEN(name_len) + old_size; 1623 1624 if (free < EXT4_XATTR_LEN(name_len) + new_size) { 1625 ret = -ENOSPC; 1626 goto out; 1627 } 1628 1629 /* 1630 * If storing the value in an external inode is an option, 1631 * reserve space for xattr entries/names in the external 1632 * attribute block so that a long value does not occupy the 1633 * whole space and prevent further entries being added. 1634 */ 1635 if (ext4_has_feature_ea_inode(inode->i_sb) && 1636 new_size && is_block && 1637 (min_offs + old_size - new_size) < 1638 EXT4_XATTR_BLOCK_RESERVE(inode)) { 1639 ret = -ENOSPC; 1640 goto out; 1641 } 1642 } 1643 1644 /* 1645 * Getting access to old and new ea inodes is subject to failures. 1646 * Finish that work before doing any modifications to the xattr data. 1647 */ 1648 if (!s->not_found && here->e_value_inum) { 1649 ret = ext4_xattr_inode_iget(inode, 1650 le32_to_cpu(here->e_value_inum), 1651 le32_to_cpu(here->e_hash), 1652 &old_ea_inode); 1653 if (ret) { 1654 old_ea_inode = NULL; 1655 goto out; 1656 } 1657 } 1658 if (i->value && in_inode) { 1659 WARN_ON_ONCE(!i->value_len); 1660 1661 ret = ext4_xattr_inode_alloc_quota(inode, i->value_len); 1662 if (ret) 1663 goto out; 1664 1665 ret = ext4_xattr_inode_lookup_create(handle, inode, i->value, 1666 i->value_len, 1667 &new_ea_inode); 1668 if (ret) { 1669 new_ea_inode = NULL; 1670 ext4_xattr_inode_free_quota(inode, NULL, i->value_len); 1671 goto out; 1672 } 1673 } 1674 1675 if (old_ea_inode) { 1676 /* We are ready to release ref count on the old_ea_inode. */ 1677 ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode); 1678 if (ret) { 1679 /* Release newly required ref count on new_ea_inode. */ 1680 if (new_ea_inode) { 1681 int err; 1682 1683 err = ext4_xattr_inode_dec_ref(handle, 1684 new_ea_inode); 1685 if (err) 1686 ext4_warning_inode(new_ea_inode, 1687 "dec ref new_ea_inode err=%d", 1688 err); 1689 ext4_xattr_inode_free_quota(inode, new_ea_inode, 1690 i->value_len); 1691 } 1692 goto out; 1693 } 1694 1695 ext4_xattr_inode_free_quota(inode, old_ea_inode, 1696 le32_to_cpu(here->e_value_size)); 1697 } 1698 1699 /* No failures allowed past this point. */ 1700 1701 if (!s->not_found && here->e_value_size && !here->e_value_inum) { 1702 /* Remove the old value. */ 1703 void *first_val = s->base + min_offs; 1704 size_t offs = le16_to_cpu(here->e_value_offs); 1705 void *val = s->base + offs; 1706 1707 memmove(first_val + old_size, first_val, val - first_val); 1708 memset(first_val, 0, old_size); 1709 min_offs += old_size; 1710 1711 /* Adjust all value offsets. */ 1712 last = s->first; 1713 while (!IS_LAST_ENTRY(last)) { 1714 size_t o = le16_to_cpu(last->e_value_offs); 1715 1716 if (!last->e_value_inum && 1717 last->e_value_size && o < offs) 1718 last->e_value_offs = cpu_to_le16(o + old_size); 1719 last = EXT4_XATTR_NEXT(last); 1720 } 1721 } 1722 1723 if (!i->value) { 1724 /* Remove old name. */ 1725 size_t size = EXT4_XATTR_LEN(name_len); 1726 1727 last = ENTRY((void *)last - size); 1728 memmove(here, (void *)here + size, 1729 (void *)last - (void *)here + sizeof(__u32)); 1730 memset(last, 0, size); 1731 } else if (s->not_found) { 1732 /* Insert new name. */ 1733 size_t size = EXT4_XATTR_LEN(name_len); 1734 size_t rest = (void *)last - (void *)here + sizeof(__u32); 1735 1736 memmove((void *)here + size, here, rest); 1737 memset(here, 0, size); 1738 here->e_name_index = i->name_index; 1739 here->e_name_len = name_len; 1740 memcpy(here->e_name, i->name, name_len); 1741 } else { 1742 /* This is an update, reset value info. */ 1743 here->e_value_inum = 0; 1744 here->e_value_offs = 0; 1745 here->e_value_size = 0; 1746 } 1747 1748 if (i->value) { 1749 /* Insert new value. */ 1750 if (in_inode) { 1751 here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino); 1752 } else if (i->value_len) { 1753 void *val = s->base + min_offs - new_size; 1754 1755 here->e_value_offs = cpu_to_le16(min_offs - new_size); 1756 if (i->value == EXT4_ZERO_XATTR_VALUE) { 1757 memset(val, 0, new_size); 1758 } else { 1759 memcpy(val, i->value, i->value_len); 1760 /* Clear padding bytes. */ 1761 memset(val + i->value_len, 0, 1762 new_size - i->value_len); 1763 } 1764 } 1765 here->e_value_size = cpu_to_le32(i->value_len); 1766 } 1767 1768 update_hash: 1769 if (i->value) { 1770 __le32 hash = 0; 1771 1772 /* Entry hash calculation. */ 1773 if (in_inode) { 1774 __le32 crc32c_hash; 1775 1776 /* 1777 * Feed crc32c hash instead of the raw value for entry 1778 * hash calculation. This is to avoid walking 1779 * potentially long value buffer again. 1780 */ 1781 crc32c_hash = cpu_to_le32( 1782 ext4_xattr_inode_get_hash(new_ea_inode)); 1783 hash = ext4_xattr_hash_entry(here->e_name, 1784 here->e_name_len, 1785 &crc32c_hash, 1); 1786 } else if (is_block) { 1787 __le32 *value = s->base + le16_to_cpu( 1788 here->e_value_offs); 1789 1790 hash = ext4_xattr_hash_entry(here->e_name, 1791 here->e_name_len, value, 1792 new_size >> 2); 1793 } 1794 here->e_hash = hash; 1795 } 1796 1797 if (is_block) 1798 ext4_xattr_rehash((struct ext4_xattr_header *)s->base); 1799 1800 ret = 0; 1801 out: 1802 iput(old_ea_inode); 1803 iput(new_ea_inode); 1804 return ret; 1805 } 1806 1807 struct ext4_xattr_block_find { 1808 struct ext4_xattr_search s; 1809 struct buffer_head *bh; 1810 }; 1811 1812 static int 1813 ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, 1814 struct ext4_xattr_block_find *bs) 1815 { 1816 struct super_block *sb = inode->i_sb; 1817 int error; 1818 1819 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 1820 i->name_index, i->name, i->value, (long)i->value_len); 1821 1822 if (EXT4_I(inode)->i_file_acl) { 1823 /* The inode already has an extended attribute block. */ 1824 bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 1825 if (IS_ERR(bs->bh)) { 1826 error = PTR_ERR(bs->bh); 1827 bs->bh = NULL; 1828 return error; 1829 } 1830 ea_bdebug(bs->bh, "b_count=%d, refcount=%d", 1831 atomic_read(&(bs->bh->b_count)), 1832 le32_to_cpu(BHDR(bs->bh)->h_refcount)); 1833 error = ext4_xattr_check_block(inode, bs->bh); 1834 if (error) 1835 return error; 1836 /* Find the named attribute. */ 1837 bs->s.base = BHDR(bs->bh); 1838 bs->s.first = BFIRST(bs->bh); 1839 bs->s.end = bs->bh->b_data + bs->bh->b_size; 1840 bs->s.here = bs->s.first; 1841 error = xattr_find_entry(inode, &bs->s.here, bs->s.end, 1842 i->name_index, i->name, 1); 1843 if (error && error != -ENODATA) 1844 return error; 1845 bs->s.not_found = error; 1846 } 1847 return 0; 1848 } 1849 1850 static int 1851 ext4_xattr_block_set(handle_t *handle, struct inode *inode, 1852 struct ext4_xattr_info *i, 1853 struct ext4_xattr_block_find *bs) 1854 { 1855 struct super_block *sb = inode->i_sb; 1856 struct buffer_head *new_bh = NULL; 1857 struct ext4_xattr_search s_copy = bs->s; 1858 struct ext4_xattr_search *s = &s_copy; 1859 struct mb_cache_entry *ce = NULL; 1860 int error = 0; 1861 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1862 struct inode *ea_inode = NULL, *tmp_inode; 1863 size_t old_ea_inode_quota = 0; 1864 unsigned int ea_ino; 1865 1866 1867 #define header(x) ((struct ext4_xattr_header *)(x)) 1868 1869 if (s->base) { 1870 int offset = (char *)s->here - bs->bh->b_data; 1871 1872 BUFFER_TRACE(bs->bh, "get_write_access"); 1873 error = ext4_journal_get_write_access(handle, sb, bs->bh, 1874 EXT4_JTR_NONE); 1875 if (error) 1876 goto cleanup; 1877 lock_buffer(bs->bh); 1878 1879 if (header(s->base)->h_refcount == cpu_to_le32(1)) { 1880 __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash); 1881 1882 /* 1883 * This must happen under buffer lock for 1884 * ext4_xattr_block_set() to reliably detect modified 1885 * block 1886 */ 1887 if (ea_block_cache) { 1888 struct mb_cache_entry *oe; 1889 1890 oe = mb_cache_entry_delete_or_get(ea_block_cache, 1891 hash, bs->bh->b_blocknr); 1892 if (oe) { 1893 /* 1894 * Xattr block is getting reused. Leave 1895 * it alone. 1896 */ 1897 mb_cache_entry_put(ea_block_cache, oe); 1898 goto clone_block; 1899 } 1900 } 1901 ea_bdebug(bs->bh, "modifying in-place"); 1902 error = ext4_xattr_set_entry(i, s, handle, inode, 1903 true /* is_block */); 1904 ext4_xattr_block_csum_set(inode, bs->bh); 1905 unlock_buffer(bs->bh); 1906 if (error == -EFSCORRUPTED) 1907 goto bad_block; 1908 if (!error) 1909 error = ext4_handle_dirty_metadata(handle, 1910 inode, 1911 bs->bh); 1912 if (error) 1913 goto cleanup; 1914 goto inserted; 1915 } 1916 clone_block: 1917 unlock_buffer(bs->bh); 1918 ea_bdebug(bs->bh, "cloning"); 1919 s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS); 1920 error = -ENOMEM; 1921 if (s->base == NULL) 1922 goto cleanup; 1923 s->first = ENTRY(header(s->base)+1); 1924 header(s->base)->h_refcount = cpu_to_le32(1); 1925 s->here = ENTRY(s->base + offset); 1926 s->end = s->base + bs->bh->b_size; 1927 1928 /* 1929 * If existing entry points to an xattr inode, we need 1930 * to prevent ext4_xattr_set_entry() from decrementing 1931 * ref count on it because the reference belongs to the 1932 * original block. In this case, make the entry look 1933 * like it has an empty value. 1934 */ 1935 if (!s->not_found && s->here->e_value_inum) { 1936 ea_ino = le32_to_cpu(s->here->e_value_inum); 1937 error = ext4_xattr_inode_iget(inode, ea_ino, 1938 le32_to_cpu(s->here->e_hash), 1939 &tmp_inode); 1940 if (error) 1941 goto cleanup; 1942 1943 if (!ext4_test_inode_state(tmp_inode, 1944 EXT4_STATE_LUSTRE_EA_INODE)) { 1945 /* 1946 * Defer quota free call for previous 1947 * inode until success is guaranteed. 1948 */ 1949 old_ea_inode_quota = le32_to_cpu( 1950 s->here->e_value_size); 1951 } 1952 iput(tmp_inode); 1953 1954 s->here->e_value_inum = 0; 1955 s->here->e_value_size = 0; 1956 } 1957 } else { 1958 /* Allocate a buffer where we construct the new block. */ 1959 s->base = kzalloc(sb->s_blocksize, GFP_NOFS); 1960 error = -ENOMEM; 1961 if (s->base == NULL) 1962 goto cleanup; 1963 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 1964 header(s->base)->h_blocks = cpu_to_le32(1); 1965 header(s->base)->h_refcount = cpu_to_le32(1); 1966 s->first = ENTRY(header(s->base)+1); 1967 s->here = ENTRY(header(s->base)+1); 1968 s->end = s->base + sb->s_blocksize; 1969 } 1970 1971 error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */); 1972 if (error == -EFSCORRUPTED) 1973 goto bad_block; 1974 if (error) 1975 goto cleanup; 1976 1977 if (i->value && s->here->e_value_inum) { 1978 /* 1979 * A ref count on ea_inode has been taken as part of the call to 1980 * ext4_xattr_set_entry() above. We would like to drop this 1981 * extra ref but we have to wait until the xattr block is 1982 * initialized and has its own ref count on the ea_inode. 1983 */ 1984 ea_ino = le32_to_cpu(s->here->e_value_inum); 1985 error = ext4_xattr_inode_iget(inode, ea_ino, 1986 le32_to_cpu(s->here->e_hash), 1987 &ea_inode); 1988 if (error) { 1989 ea_inode = NULL; 1990 goto cleanup; 1991 } 1992 } 1993 1994 inserted: 1995 if (!IS_LAST_ENTRY(s->first)) { 1996 new_bh = ext4_xattr_block_cache_find(inode, header(s->base), 1997 &ce); 1998 if (new_bh) { 1999 /* We found an identical block in the cache. */ 2000 if (new_bh == bs->bh) 2001 ea_bdebug(new_bh, "keeping"); 2002 else { 2003 u32 ref; 2004 2005 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2006 2007 /* The old block is released after updating 2008 the inode. */ 2009 error = dquot_alloc_block(inode, 2010 EXT4_C2B(EXT4_SB(sb), 1)); 2011 if (error) 2012 goto cleanup; 2013 BUFFER_TRACE(new_bh, "get_write_access"); 2014 error = ext4_journal_get_write_access( 2015 handle, sb, new_bh, 2016 EXT4_JTR_NONE); 2017 if (error) 2018 goto cleanup_dquot; 2019 lock_buffer(new_bh); 2020 /* 2021 * We have to be careful about races with 2022 * adding references to xattr block. Once we 2023 * hold buffer lock xattr block's state is 2024 * stable so we can check the additional 2025 * reference fits. 2026 */ 2027 ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1; 2028 if (ref > EXT4_XATTR_REFCOUNT_MAX) { 2029 /* 2030 * Undo everything and check mbcache 2031 * again. 2032 */ 2033 unlock_buffer(new_bh); 2034 dquot_free_block(inode, 2035 EXT4_C2B(EXT4_SB(sb), 2036 1)); 2037 brelse(new_bh); 2038 mb_cache_entry_put(ea_block_cache, ce); 2039 ce = NULL; 2040 new_bh = NULL; 2041 goto inserted; 2042 } 2043 BHDR(new_bh)->h_refcount = cpu_to_le32(ref); 2044 if (ref == EXT4_XATTR_REFCOUNT_MAX) 2045 ce->e_reusable = 0; 2046 ea_bdebug(new_bh, "reusing; refcount now=%d", 2047 ref); 2048 ext4_xattr_block_csum_set(inode, new_bh); 2049 unlock_buffer(new_bh); 2050 error = ext4_handle_dirty_metadata(handle, 2051 inode, 2052 new_bh); 2053 if (error) 2054 goto cleanup_dquot; 2055 } 2056 mb_cache_entry_touch(ea_block_cache, ce); 2057 mb_cache_entry_put(ea_block_cache, ce); 2058 ce = NULL; 2059 } else if (bs->bh && s->base == bs->bh->b_data) { 2060 /* We were modifying this block in-place. */ 2061 ea_bdebug(bs->bh, "keeping this block"); 2062 ext4_xattr_block_cache_insert(ea_block_cache, bs->bh); 2063 new_bh = bs->bh; 2064 get_bh(new_bh); 2065 } else { 2066 /* We need to allocate a new block */ 2067 ext4_fsblk_t goal, block; 2068 2069 WARN_ON_ONCE(dquot_initialize_needed(inode)); 2070 2071 goal = ext4_group_first_block_no(sb, 2072 EXT4_I(inode)->i_block_group); 2073 2074 /* non-extent files can't have physical blocks past 2^32 */ 2075 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2076 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; 2077 2078 block = ext4_new_meta_blocks(handle, inode, goal, 0, 2079 NULL, &error); 2080 if (error) 2081 goto cleanup; 2082 2083 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 2084 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); 2085 2086 ea_idebug(inode, "creating block %llu", 2087 (unsigned long long)block); 2088 2089 new_bh = sb_getblk(sb, block); 2090 if (unlikely(!new_bh)) { 2091 error = -ENOMEM; 2092 getblk_failed: 2093 ext4_free_blocks(handle, inode, NULL, block, 1, 2094 EXT4_FREE_BLOCKS_METADATA); 2095 goto cleanup; 2096 } 2097 error = ext4_xattr_inode_inc_ref_all(handle, inode, 2098 ENTRY(header(s->base)+1)); 2099 if (error) 2100 goto getblk_failed; 2101 if (ea_inode) { 2102 /* Drop the extra ref on ea_inode. */ 2103 error = ext4_xattr_inode_dec_ref(handle, 2104 ea_inode); 2105 if (error) 2106 ext4_warning_inode(ea_inode, 2107 "dec ref error=%d", 2108 error); 2109 iput(ea_inode); 2110 ea_inode = NULL; 2111 } 2112 2113 lock_buffer(new_bh); 2114 error = ext4_journal_get_create_access(handle, sb, 2115 new_bh, EXT4_JTR_NONE); 2116 if (error) { 2117 unlock_buffer(new_bh); 2118 error = -EIO; 2119 goto getblk_failed; 2120 } 2121 memcpy(new_bh->b_data, s->base, new_bh->b_size); 2122 ext4_xattr_block_csum_set(inode, new_bh); 2123 set_buffer_uptodate(new_bh); 2124 unlock_buffer(new_bh); 2125 ext4_xattr_block_cache_insert(ea_block_cache, new_bh); 2126 error = ext4_handle_dirty_metadata(handle, inode, 2127 new_bh); 2128 if (error) 2129 goto cleanup; 2130 } 2131 } 2132 2133 if (old_ea_inode_quota) 2134 ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota); 2135 2136 /* Update the inode. */ 2137 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 2138 2139 /* Drop the previous xattr block. */ 2140 if (bs->bh && bs->bh != new_bh) { 2141 struct ext4_xattr_inode_array *ea_inode_array = NULL; 2142 2143 ext4_xattr_release_block(handle, inode, bs->bh, 2144 &ea_inode_array, 2145 0 /* extra_credits */); 2146 ext4_xattr_inode_array_free(ea_inode_array); 2147 } 2148 error = 0; 2149 2150 cleanup: 2151 if (ea_inode) { 2152 int error2; 2153 2154 error2 = ext4_xattr_inode_dec_ref(handle, ea_inode); 2155 if (error2) 2156 ext4_warning_inode(ea_inode, "dec ref error=%d", 2157 error2); 2158 2159 /* If there was an error, revert the quota charge. */ 2160 if (error) 2161 ext4_xattr_inode_free_quota(inode, ea_inode, 2162 i_size_read(ea_inode)); 2163 iput(ea_inode); 2164 } 2165 if (ce) 2166 mb_cache_entry_put(ea_block_cache, ce); 2167 brelse(new_bh); 2168 if (!(bs->bh && s->base == bs->bh->b_data)) 2169 kfree(s->base); 2170 2171 return error; 2172 2173 cleanup_dquot: 2174 dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1)); 2175 goto cleanup; 2176 2177 bad_block: 2178 EXT4_ERROR_INODE(inode, "bad block %llu", 2179 EXT4_I(inode)->i_file_acl); 2180 goto cleanup; 2181 2182 #undef header 2183 } 2184 2185 int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 2186 struct ext4_xattr_ibody_find *is) 2187 { 2188 struct ext4_xattr_ibody_header *header; 2189 struct ext4_inode *raw_inode; 2190 int error; 2191 2192 if (!EXT4_INODE_HAS_XATTR_SPACE(inode)) 2193 return 0; 2194 2195 raw_inode = ext4_raw_inode(&is->iloc); 2196 header = IHDR(inode, raw_inode); 2197 is->s.base = is->s.first = IFIRST(header); 2198 is->s.here = is->s.first; 2199 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2200 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2201 error = xattr_check_inode(inode, header, is->s.end); 2202 if (error) 2203 return error; 2204 /* Find the named attribute. */ 2205 error = xattr_find_entry(inode, &is->s.here, is->s.end, 2206 i->name_index, i->name, 0); 2207 if (error && error != -ENODATA) 2208 return error; 2209 is->s.not_found = error; 2210 } 2211 return 0; 2212 } 2213 2214 int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, 2215 struct ext4_xattr_info *i, 2216 struct ext4_xattr_ibody_find *is) 2217 { 2218 struct ext4_xattr_ibody_header *header; 2219 struct ext4_xattr_search *s = &is->s; 2220 int error; 2221 2222 if (!EXT4_INODE_HAS_XATTR_SPACE(inode)) 2223 return -ENOSPC; 2224 2225 error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); 2226 if (error) 2227 return error; 2228 header = IHDR(inode, ext4_raw_inode(&is->iloc)); 2229 if (!IS_LAST_ENTRY(s->first)) { 2230 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); 2231 ext4_set_inode_state(inode, EXT4_STATE_XATTR); 2232 } else { 2233 header->h_magic = cpu_to_le32(0); 2234 ext4_clear_inode_state(inode, EXT4_STATE_XATTR); 2235 } 2236 return 0; 2237 } 2238 2239 static int ext4_xattr_value_same(struct ext4_xattr_search *s, 2240 struct ext4_xattr_info *i) 2241 { 2242 void *value; 2243 2244 /* When e_value_inum is set the value is stored externally. */ 2245 if (s->here->e_value_inum) 2246 return 0; 2247 if (le32_to_cpu(s->here->e_value_size) != i->value_len) 2248 return 0; 2249 value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs); 2250 return !memcmp(value, i->value, i->value_len); 2251 } 2252 2253 static struct buffer_head *ext4_xattr_get_block(struct inode *inode) 2254 { 2255 struct buffer_head *bh; 2256 int error; 2257 2258 if (!EXT4_I(inode)->i_file_acl) 2259 return NULL; 2260 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2261 if (IS_ERR(bh)) 2262 return bh; 2263 error = ext4_xattr_check_block(inode, bh); 2264 if (error) { 2265 brelse(bh); 2266 return ERR_PTR(error); 2267 } 2268 return bh; 2269 } 2270 2271 /* 2272 * ext4_xattr_set_handle() 2273 * 2274 * Create, replace or remove an extended attribute for this inode. Value 2275 * is NULL to remove an existing extended attribute, and non-NULL to 2276 * either replace an existing extended attribute, or create a new extended 2277 * attribute. The flags XATTR_REPLACE and XATTR_CREATE 2278 * specify that an extended attribute must exist and must not exist 2279 * previous to the call, respectively. 2280 * 2281 * Returns 0, or a negative error number on failure. 2282 */ 2283 int 2284 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 2285 const char *name, const void *value, size_t value_len, 2286 int flags) 2287 { 2288 struct ext4_xattr_info i = { 2289 .name_index = name_index, 2290 .name = name, 2291 .value = value, 2292 .value_len = value_len, 2293 .in_inode = 0, 2294 }; 2295 struct ext4_xattr_ibody_find is = { 2296 .s = { .not_found = -ENODATA, }, 2297 }; 2298 struct ext4_xattr_block_find bs = { 2299 .s = { .not_found = -ENODATA, }, 2300 }; 2301 int no_expand; 2302 int error; 2303 2304 if (!name) 2305 return -EINVAL; 2306 if (strlen(name) > 255) 2307 return -ERANGE; 2308 2309 ext4_write_lock_xattr(inode, &no_expand); 2310 2311 /* Check journal credits under write lock. */ 2312 if (ext4_handle_valid(handle)) { 2313 struct buffer_head *bh; 2314 int credits; 2315 2316 bh = ext4_xattr_get_block(inode); 2317 if (IS_ERR(bh)) { 2318 error = PTR_ERR(bh); 2319 goto cleanup; 2320 } 2321 2322 credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2323 value_len, 2324 flags & XATTR_CREATE); 2325 brelse(bh); 2326 2327 if (jbd2_handle_buffer_credits(handle) < credits) { 2328 error = -ENOSPC; 2329 goto cleanup; 2330 } 2331 WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS)); 2332 } 2333 2334 error = ext4_reserve_inode_write(handle, inode, &is.iloc); 2335 if (error) 2336 goto cleanup; 2337 2338 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { 2339 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); 2340 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); 2341 ext4_clear_inode_state(inode, EXT4_STATE_NEW); 2342 } 2343 2344 error = ext4_xattr_ibody_find(inode, &i, &is); 2345 if (error) 2346 goto cleanup; 2347 if (is.s.not_found) 2348 error = ext4_xattr_block_find(inode, &i, &bs); 2349 if (error) 2350 goto cleanup; 2351 if (is.s.not_found && bs.s.not_found) { 2352 error = -ENODATA; 2353 if (flags & XATTR_REPLACE) 2354 goto cleanup; 2355 error = 0; 2356 if (!value) 2357 goto cleanup; 2358 } else { 2359 error = -EEXIST; 2360 if (flags & XATTR_CREATE) 2361 goto cleanup; 2362 } 2363 2364 if (!value) { 2365 if (!is.s.not_found) 2366 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2367 else if (!bs.s.not_found) 2368 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2369 } else { 2370 error = 0; 2371 /* Xattr value did not change? Save us some work and bail out */ 2372 if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i)) 2373 goto cleanup; 2374 if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i)) 2375 goto cleanup; 2376 2377 if (ext4_has_feature_ea_inode(inode->i_sb) && 2378 (EXT4_XATTR_SIZE(i.value_len) > 2379 EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize))) 2380 i.in_inode = 1; 2381 retry_inode: 2382 error = ext4_xattr_ibody_set(handle, inode, &i, &is); 2383 if (!error && !bs.s.not_found) { 2384 i.value = NULL; 2385 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2386 } else if (error == -ENOSPC) { 2387 if (EXT4_I(inode)->i_file_acl && !bs.s.base) { 2388 brelse(bs.bh); 2389 bs.bh = NULL; 2390 error = ext4_xattr_block_find(inode, &i, &bs); 2391 if (error) 2392 goto cleanup; 2393 } 2394 error = ext4_xattr_block_set(handle, inode, &i, &bs); 2395 if (!error && !is.s.not_found) { 2396 i.value = NULL; 2397 error = ext4_xattr_ibody_set(handle, inode, &i, 2398 &is); 2399 } else if (error == -ENOSPC) { 2400 /* 2401 * Xattr does not fit in the block, store at 2402 * external inode if possible. 2403 */ 2404 if (ext4_has_feature_ea_inode(inode->i_sb) && 2405 i.value_len && !i.in_inode) { 2406 i.in_inode = 1; 2407 goto retry_inode; 2408 } 2409 } 2410 } 2411 } 2412 if (!error) { 2413 ext4_xattr_update_super_block(handle, inode->i_sb); 2414 inode->i_ctime = current_time(inode); 2415 inode_inc_iversion(inode); 2416 if (!value) 2417 no_expand = 0; 2418 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); 2419 /* 2420 * The bh is consumed by ext4_mark_iloc_dirty, even with 2421 * error != 0. 2422 */ 2423 is.iloc.bh = NULL; 2424 if (IS_SYNC(inode)) 2425 ext4_handle_sync(handle); 2426 } 2427 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle); 2428 2429 cleanup: 2430 brelse(is.iloc.bh); 2431 brelse(bs.bh); 2432 ext4_write_unlock_xattr(inode, &no_expand); 2433 return error; 2434 } 2435 2436 int ext4_xattr_set_credits(struct inode *inode, size_t value_len, 2437 bool is_create, int *credits) 2438 { 2439 struct buffer_head *bh; 2440 int err; 2441 2442 *credits = 0; 2443 2444 if (!EXT4_SB(inode->i_sb)->s_journal) 2445 return 0; 2446 2447 down_read(&EXT4_I(inode)->xattr_sem); 2448 2449 bh = ext4_xattr_get_block(inode); 2450 if (IS_ERR(bh)) { 2451 err = PTR_ERR(bh); 2452 } else { 2453 *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh, 2454 value_len, is_create); 2455 brelse(bh); 2456 err = 0; 2457 } 2458 2459 up_read(&EXT4_I(inode)->xattr_sem); 2460 return err; 2461 } 2462 2463 /* 2464 * ext4_xattr_set() 2465 * 2466 * Like ext4_xattr_set_handle, but start from an inode. This extended 2467 * attribute modification is a filesystem transaction by itself. 2468 * 2469 * Returns 0, or a negative error number on failure. 2470 */ 2471 int 2472 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 2473 const void *value, size_t value_len, int flags) 2474 { 2475 handle_t *handle; 2476 struct super_block *sb = inode->i_sb; 2477 int error, retries = 0; 2478 int credits; 2479 2480 error = dquot_initialize(inode); 2481 if (error) 2482 return error; 2483 2484 retry: 2485 error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE, 2486 &credits); 2487 if (error) 2488 return error; 2489 2490 handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); 2491 if (IS_ERR(handle)) { 2492 error = PTR_ERR(handle); 2493 } else { 2494 int error2; 2495 2496 error = ext4_xattr_set_handle(handle, inode, name_index, name, 2497 value, value_len, flags); 2498 error2 = ext4_journal_stop(handle); 2499 if (error == -ENOSPC && 2500 ext4_should_retry_alloc(sb, &retries)) 2501 goto retry; 2502 if (error == 0) 2503 error = error2; 2504 } 2505 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL); 2506 2507 return error; 2508 } 2509 2510 /* 2511 * Shift the EA entries in the inode to create space for the increased 2512 * i_extra_isize. 2513 */ 2514 static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, 2515 int value_offs_shift, void *to, 2516 void *from, size_t n) 2517 { 2518 struct ext4_xattr_entry *last = entry; 2519 int new_offs; 2520 2521 /* We always shift xattr headers further thus offsets get lower */ 2522 BUG_ON(value_offs_shift > 0); 2523 2524 /* Adjust the value offsets of the entries */ 2525 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2526 if (!last->e_value_inum && last->e_value_size) { 2527 new_offs = le16_to_cpu(last->e_value_offs) + 2528 value_offs_shift; 2529 last->e_value_offs = cpu_to_le16(new_offs); 2530 } 2531 } 2532 /* Shift the entries by n bytes */ 2533 memmove(to, from, n); 2534 } 2535 2536 /* 2537 * Move xattr pointed to by 'entry' from inode into external xattr block 2538 */ 2539 static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode, 2540 struct ext4_inode *raw_inode, 2541 struct ext4_xattr_entry *entry) 2542 { 2543 struct ext4_xattr_ibody_find *is = NULL; 2544 struct ext4_xattr_block_find *bs = NULL; 2545 char *buffer = NULL, *b_entry_name = NULL; 2546 size_t value_size = le32_to_cpu(entry->e_value_size); 2547 struct ext4_xattr_info i = { 2548 .value = NULL, 2549 .value_len = 0, 2550 .name_index = entry->e_name_index, 2551 .in_inode = !!entry->e_value_inum, 2552 }; 2553 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2554 int error; 2555 2556 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); 2557 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); 2558 buffer = kmalloc(value_size, GFP_NOFS); 2559 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); 2560 if (!is || !bs || !buffer || !b_entry_name) { 2561 error = -ENOMEM; 2562 goto out; 2563 } 2564 2565 is->s.not_found = -ENODATA; 2566 bs->s.not_found = -ENODATA; 2567 is->iloc.bh = NULL; 2568 bs->bh = NULL; 2569 2570 /* Save the entry name and the entry value */ 2571 if (entry->e_value_inum) { 2572 error = ext4_xattr_inode_get(inode, entry, buffer, value_size); 2573 if (error) 2574 goto out; 2575 } else { 2576 size_t value_offs = le16_to_cpu(entry->e_value_offs); 2577 memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size); 2578 } 2579 2580 memcpy(b_entry_name, entry->e_name, entry->e_name_len); 2581 b_entry_name[entry->e_name_len] = '\0'; 2582 i.name = b_entry_name; 2583 2584 error = ext4_get_inode_loc(inode, &is->iloc); 2585 if (error) 2586 goto out; 2587 2588 error = ext4_xattr_ibody_find(inode, &i, is); 2589 if (error) 2590 goto out; 2591 2592 /* Remove the chosen entry from the inode */ 2593 error = ext4_xattr_ibody_set(handle, inode, &i, is); 2594 if (error) 2595 goto out; 2596 2597 i.value = buffer; 2598 i.value_len = value_size; 2599 error = ext4_xattr_block_find(inode, &i, bs); 2600 if (error) 2601 goto out; 2602 2603 /* Add entry which was removed from the inode into the block */ 2604 error = ext4_xattr_block_set(handle, inode, &i, bs); 2605 if (error) 2606 goto out; 2607 error = 0; 2608 out: 2609 kfree(b_entry_name); 2610 kfree(buffer); 2611 if (is) 2612 brelse(is->iloc.bh); 2613 if (bs) 2614 brelse(bs->bh); 2615 kfree(is); 2616 kfree(bs); 2617 2618 return error; 2619 } 2620 2621 static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode, 2622 struct ext4_inode *raw_inode, 2623 int isize_diff, size_t ifree, 2624 size_t bfree, int *total_ino) 2625 { 2626 struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); 2627 struct ext4_xattr_entry *small_entry; 2628 struct ext4_xattr_entry *entry; 2629 struct ext4_xattr_entry *last; 2630 unsigned int entry_size; /* EA entry size */ 2631 unsigned int total_size; /* EA entry size + value size */ 2632 unsigned int min_total_size; 2633 int error; 2634 2635 while (isize_diff > ifree) { 2636 entry = NULL; 2637 small_entry = NULL; 2638 min_total_size = ~0U; 2639 last = IFIRST(header); 2640 /* Find the entry best suited to be pushed into EA block */ 2641 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { 2642 /* never move system.data out of the inode */ 2643 if ((last->e_name_len == 4) && 2644 (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) && 2645 !memcmp(last->e_name, "data", 4)) 2646 continue; 2647 total_size = EXT4_XATTR_LEN(last->e_name_len); 2648 if (!last->e_value_inum) 2649 total_size += EXT4_XATTR_SIZE( 2650 le32_to_cpu(last->e_value_size)); 2651 if (total_size <= bfree && 2652 total_size < min_total_size) { 2653 if (total_size + ifree < isize_diff) { 2654 small_entry = last; 2655 } else { 2656 entry = last; 2657 min_total_size = total_size; 2658 } 2659 } 2660 } 2661 2662 if (entry == NULL) { 2663 if (small_entry == NULL) 2664 return -ENOSPC; 2665 entry = small_entry; 2666 } 2667 2668 entry_size = EXT4_XATTR_LEN(entry->e_name_len); 2669 total_size = entry_size; 2670 if (!entry->e_value_inum) 2671 total_size += EXT4_XATTR_SIZE( 2672 le32_to_cpu(entry->e_value_size)); 2673 error = ext4_xattr_move_to_block(handle, inode, raw_inode, 2674 entry); 2675 if (error) 2676 return error; 2677 2678 *total_ino -= entry_size; 2679 ifree += total_size; 2680 bfree -= total_size; 2681 } 2682 2683 return 0; 2684 } 2685 2686 /* 2687 * Expand an inode by new_extra_isize bytes when EAs are present. 2688 * Returns 0 on success or negative error number on failure. 2689 */ 2690 int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 2691 struct ext4_inode *raw_inode, handle_t *handle) 2692 { 2693 struct ext4_xattr_ibody_header *header; 2694 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2695 static unsigned int mnt_count; 2696 size_t min_offs; 2697 size_t ifree, bfree; 2698 int total_ino; 2699 void *base, *end; 2700 int error = 0, tried_min_extra_isize = 0; 2701 int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize); 2702 int isize_diff; /* How much do we need to grow i_extra_isize */ 2703 2704 retry: 2705 isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; 2706 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) 2707 return 0; 2708 2709 header = IHDR(inode, raw_inode); 2710 2711 /* 2712 * Check if enough free space is available in the inode to shift the 2713 * entries ahead by new_extra_isize. 2714 */ 2715 2716 base = IFIRST(header); 2717 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; 2718 min_offs = end - base; 2719 total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32); 2720 2721 error = xattr_check_inode(inode, header, end); 2722 if (error) 2723 goto cleanup; 2724 2725 ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino); 2726 if (ifree >= isize_diff) 2727 goto shift; 2728 2729 /* 2730 * Enough free space isn't available in the inode, check if 2731 * EA block can hold new_extra_isize bytes. 2732 */ 2733 if (EXT4_I(inode)->i_file_acl) { 2734 struct buffer_head *bh; 2735 2736 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2737 if (IS_ERR(bh)) { 2738 error = PTR_ERR(bh); 2739 goto cleanup; 2740 } 2741 error = ext4_xattr_check_block(inode, bh); 2742 if (error) { 2743 brelse(bh); 2744 goto cleanup; 2745 } 2746 base = BHDR(bh); 2747 end = bh->b_data + bh->b_size; 2748 min_offs = end - base; 2749 bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base, 2750 NULL); 2751 brelse(bh); 2752 if (bfree + ifree < isize_diff) { 2753 if (!tried_min_extra_isize && s_min_extra_isize) { 2754 tried_min_extra_isize++; 2755 new_extra_isize = s_min_extra_isize; 2756 goto retry; 2757 } 2758 error = -ENOSPC; 2759 goto cleanup; 2760 } 2761 } else { 2762 bfree = inode->i_sb->s_blocksize; 2763 } 2764 2765 error = ext4_xattr_make_inode_space(handle, inode, raw_inode, 2766 isize_diff, ifree, bfree, 2767 &total_ino); 2768 if (error) { 2769 if (error == -ENOSPC && !tried_min_extra_isize && 2770 s_min_extra_isize) { 2771 tried_min_extra_isize++; 2772 new_extra_isize = s_min_extra_isize; 2773 goto retry; 2774 } 2775 goto cleanup; 2776 } 2777 shift: 2778 /* Adjust the offsets and shift the remaining entries ahead */ 2779 ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize 2780 - new_extra_isize, (void *)raw_inode + 2781 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, 2782 (void *)header, total_ino); 2783 EXT4_I(inode)->i_extra_isize = new_extra_isize; 2784 2785 cleanup: 2786 if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) { 2787 ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.", 2788 inode->i_ino); 2789 mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count); 2790 } 2791 return error; 2792 } 2793 2794 #define EIA_INCR 16 /* must be 2^n */ 2795 #define EIA_MASK (EIA_INCR - 1) 2796 2797 /* Add the large xattr @inode into @ea_inode_array for deferred iput(). 2798 * If @ea_inode_array is new or full it will be grown and the old 2799 * contents copied over. 2800 */ 2801 static int 2802 ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, 2803 struct inode *inode) 2804 { 2805 if (*ea_inode_array == NULL) { 2806 /* 2807 * Start with 15 inodes, so it fits into a power-of-two size. 2808 * If *ea_inode_array is NULL, this is essentially offsetof() 2809 */ 2810 (*ea_inode_array) = 2811 kmalloc(offsetof(struct ext4_xattr_inode_array, 2812 inodes[EIA_MASK]), 2813 GFP_NOFS); 2814 if (*ea_inode_array == NULL) 2815 return -ENOMEM; 2816 (*ea_inode_array)->count = 0; 2817 } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { 2818 /* expand the array once all 15 + n * 16 slots are full */ 2819 struct ext4_xattr_inode_array *new_array = NULL; 2820 int count = (*ea_inode_array)->count; 2821 2822 /* if new_array is NULL, this is essentially offsetof() */ 2823 new_array = kmalloc( 2824 offsetof(struct ext4_xattr_inode_array, 2825 inodes[count + EIA_INCR]), 2826 GFP_NOFS); 2827 if (new_array == NULL) 2828 return -ENOMEM; 2829 memcpy(new_array, *ea_inode_array, 2830 offsetof(struct ext4_xattr_inode_array, inodes[count])); 2831 kfree(*ea_inode_array); 2832 *ea_inode_array = new_array; 2833 } 2834 (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; 2835 return 0; 2836 } 2837 2838 /* 2839 * ext4_xattr_delete_inode() 2840 * 2841 * Free extended attribute resources associated with this inode. Traverse 2842 * all entries and decrement reference on any xattr inodes associated with this 2843 * inode. This is called immediately before an inode is freed. We have exclusive 2844 * access to the inode. If an orphan inode is deleted it will also release its 2845 * references on xattr block and xattr inodes. 2846 */ 2847 int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, 2848 struct ext4_xattr_inode_array **ea_inode_array, 2849 int extra_credits) 2850 { 2851 struct buffer_head *bh = NULL; 2852 struct ext4_xattr_ibody_header *header; 2853 struct ext4_iloc iloc = { .bh = NULL }; 2854 struct ext4_xattr_entry *entry; 2855 struct inode *ea_inode; 2856 int error; 2857 2858 error = ext4_journal_ensure_credits(handle, extra_credits, 2859 ext4_free_metadata_revoke_credits(inode->i_sb, 1)); 2860 if (error < 0) { 2861 EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); 2862 goto cleanup; 2863 } 2864 2865 if (ext4_has_feature_ea_inode(inode->i_sb) && 2866 ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { 2867 2868 error = ext4_get_inode_loc(inode, &iloc); 2869 if (error) { 2870 EXT4_ERROR_INODE(inode, "inode loc (error %d)", error); 2871 goto cleanup; 2872 } 2873 2874 error = ext4_journal_get_write_access(handle, inode->i_sb, 2875 iloc.bh, EXT4_JTR_NONE); 2876 if (error) { 2877 EXT4_ERROR_INODE(inode, "write access (error %d)", 2878 error); 2879 goto cleanup; 2880 } 2881 2882 header = IHDR(inode, ext4_raw_inode(&iloc)); 2883 if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC)) 2884 ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh, 2885 IFIRST(header), 2886 false /* block_csum */, 2887 ea_inode_array, 2888 extra_credits, 2889 false /* skip_quota */); 2890 } 2891 2892 if (EXT4_I(inode)->i_file_acl) { 2893 bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); 2894 if (IS_ERR(bh)) { 2895 error = PTR_ERR(bh); 2896 if (error == -EIO) { 2897 EXT4_ERROR_INODE_ERR(inode, EIO, 2898 "block %llu read error", 2899 EXT4_I(inode)->i_file_acl); 2900 } 2901 bh = NULL; 2902 goto cleanup; 2903 } 2904 error = ext4_xattr_check_block(inode, bh); 2905 if (error) 2906 goto cleanup; 2907 2908 if (ext4_has_feature_ea_inode(inode->i_sb)) { 2909 for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); 2910 entry = EXT4_XATTR_NEXT(entry)) { 2911 if (!entry->e_value_inum) 2912 continue; 2913 error = ext4_xattr_inode_iget(inode, 2914 le32_to_cpu(entry->e_value_inum), 2915 le32_to_cpu(entry->e_hash), 2916 &ea_inode); 2917 if (error) 2918 continue; 2919 ext4_xattr_inode_free_quota(inode, ea_inode, 2920 le32_to_cpu(entry->e_value_size)); 2921 iput(ea_inode); 2922 } 2923 2924 } 2925 2926 ext4_xattr_release_block(handle, inode, bh, ea_inode_array, 2927 extra_credits); 2928 /* 2929 * Update i_file_acl value in the same transaction that releases 2930 * block. 2931 */ 2932 EXT4_I(inode)->i_file_acl = 0; 2933 error = ext4_mark_inode_dirty(handle, inode); 2934 if (error) { 2935 EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", 2936 error); 2937 goto cleanup; 2938 } 2939 ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle); 2940 } 2941 error = 0; 2942 cleanup: 2943 brelse(iloc.bh); 2944 brelse(bh); 2945 return error; 2946 } 2947 2948 void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array) 2949 { 2950 int idx; 2951 2952 if (ea_inode_array == NULL) 2953 return; 2954 2955 for (idx = 0; idx < ea_inode_array->count; ++idx) 2956 iput(ea_inode_array->inodes[idx]); 2957 kfree(ea_inode_array); 2958 } 2959 2960 /* 2961 * ext4_xattr_block_cache_insert() 2962 * 2963 * Create a new entry in the extended attribute block cache, and insert 2964 * it unless such an entry is already in the cache. 2965 * 2966 * Returns 0, or a negative error number on failure. 2967 */ 2968 static void 2969 ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache, 2970 struct buffer_head *bh) 2971 { 2972 struct ext4_xattr_header *header = BHDR(bh); 2973 __u32 hash = le32_to_cpu(header->h_hash); 2974 int reusable = le32_to_cpu(header->h_refcount) < 2975 EXT4_XATTR_REFCOUNT_MAX; 2976 int error; 2977 2978 if (!ea_block_cache) 2979 return; 2980 error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash, 2981 bh->b_blocknr, reusable); 2982 if (error) { 2983 if (error == -EBUSY) 2984 ea_bdebug(bh, "already in cache"); 2985 } else 2986 ea_bdebug(bh, "inserting [%x]", (int)hash); 2987 } 2988 2989 /* 2990 * ext4_xattr_cmp() 2991 * 2992 * Compare two extended attribute blocks for equality. 2993 * 2994 * Returns 0 if the blocks are equal, 1 if they differ, and 2995 * a negative error number on errors. 2996 */ 2997 static int 2998 ext4_xattr_cmp(struct ext4_xattr_header *header1, 2999 struct ext4_xattr_header *header2) 3000 { 3001 struct ext4_xattr_entry *entry1, *entry2; 3002 3003 entry1 = ENTRY(header1+1); 3004 entry2 = ENTRY(header2+1); 3005 while (!IS_LAST_ENTRY(entry1)) { 3006 if (IS_LAST_ENTRY(entry2)) 3007 return 1; 3008 if (entry1->e_hash != entry2->e_hash || 3009 entry1->e_name_index != entry2->e_name_index || 3010 entry1->e_name_len != entry2->e_name_len || 3011 entry1->e_value_size != entry2->e_value_size || 3012 entry1->e_value_inum != entry2->e_value_inum || 3013 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 3014 return 1; 3015 if (!entry1->e_value_inum && 3016 memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 3017 (char *)header2 + le16_to_cpu(entry2->e_value_offs), 3018 le32_to_cpu(entry1->e_value_size))) 3019 return 1; 3020 3021 entry1 = EXT4_XATTR_NEXT(entry1); 3022 entry2 = EXT4_XATTR_NEXT(entry2); 3023 } 3024 if (!IS_LAST_ENTRY(entry2)) 3025 return 1; 3026 return 0; 3027 } 3028 3029 /* 3030 * ext4_xattr_block_cache_find() 3031 * 3032 * Find an identical extended attribute block. 3033 * 3034 * Returns a pointer to the block found, or NULL if such a block was 3035 * not found or an error occurred. 3036 */ 3037 static struct buffer_head * 3038 ext4_xattr_block_cache_find(struct inode *inode, 3039 struct ext4_xattr_header *header, 3040 struct mb_cache_entry **pce) 3041 { 3042 __u32 hash = le32_to_cpu(header->h_hash); 3043 struct mb_cache_entry *ce; 3044 struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 3045 3046 if (!ea_block_cache) 3047 return NULL; 3048 if (!header->h_hash) 3049 return NULL; /* never share */ 3050 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 3051 ce = mb_cache_entry_find_first(ea_block_cache, hash); 3052 while (ce) { 3053 struct buffer_head *bh; 3054 3055 bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO); 3056 if (IS_ERR(bh)) { 3057 if (PTR_ERR(bh) == -ENOMEM) 3058 return NULL; 3059 bh = NULL; 3060 EXT4_ERROR_INODE(inode, "block %lu read error", 3061 (unsigned long)ce->e_value); 3062 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { 3063 *pce = ce; 3064 return bh; 3065 } 3066 brelse(bh); 3067 ce = mb_cache_entry_find_next(ea_block_cache, ce); 3068 } 3069 return NULL; 3070 } 3071 3072 #define NAME_HASH_SHIFT 5 3073 #define VALUE_HASH_SHIFT 16 3074 3075 /* 3076 * ext4_xattr_hash_entry() 3077 * 3078 * Compute the hash of an extended attribute. 3079 */ 3080 static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value, 3081 size_t value_count) 3082 { 3083 __u32 hash = 0; 3084 3085 while (name_len--) { 3086 hash = (hash << NAME_HASH_SHIFT) ^ 3087 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 3088 *name++; 3089 } 3090 while (value_count--) { 3091 hash = (hash << VALUE_HASH_SHIFT) ^ 3092 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 3093 le32_to_cpu(*value++); 3094 } 3095 return cpu_to_le32(hash); 3096 } 3097 3098 #undef NAME_HASH_SHIFT 3099 #undef VALUE_HASH_SHIFT 3100 3101 #define BLOCK_HASH_SHIFT 16 3102 3103 /* 3104 * ext4_xattr_rehash() 3105 * 3106 * Re-compute the extended attribute hash value after an entry has changed. 3107 */ 3108 static void ext4_xattr_rehash(struct ext4_xattr_header *header) 3109 { 3110 struct ext4_xattr_entry *here; 3111 __u32 hash = 0; 3112 3113 here = ENTRY(header+1); 3114 while (!IS_LAST_ENTRY(here)) { 3115 if (!here->e_hash) { 3116 /* Block is not shared if an entry's hash value == 0 */ 3117 hash = 0; 3118 break; 3119 } 3120 hash = (hash << BLOCK_HASH_SHIFT) ^ 3121 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 3122 le32_to_cpu(here->e_hash); 3123 here = EXT4_XATTR_NEXT(here); 3124 } 3125 header->h_hash = cpu_to_le32(hash); 3126 } 3127 3128 #undef BLOCK_HASH_SHIFT 3129 3130 #define HASH_BUCKET_BITS 10 3131 3132 struct mb_cache * 3133 ext4_xattr_create_cache(void) 3134 { 3135 return mb_cache_create(HASH_BUCKET_BITS); 3136 } 3137 3138 void ext4_xattr_destroy_cache(struct mb_cache *cache) 3139 { 3140 if (cache) 3141 mb_cache_destroy(cache); 3142 } 3143 3144