1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. 4 */ 5 6 #include <linux/init.h> 7 #include <linux/buffer_head.h> 8 #include <linux/mpage.h> 9 #include <linux/bio.h> 10 #include <linux/blkdev.h> 11 #include <linux/time.h> 12 #include <linux/writeback.h> 13 #include <linux/uio.h> 14 #include <linux/random.h> 15 #include <linux/iversion.h> 16 17 #include "exfat_raw.h" 18 #include "exfat_fs.h" 19 20 int __exfat_write_inode(struct inode *inode, int sync) 21 { 22 unsigned long long on_disk_size; 23 struct exfat_dentry *ep, *ep2; 24 struct exfat_entry_set_cache es; 25 struct super_block *sb = inode->i_sb; 26 struct exfat_sb_info *sbi = EXFAT_SB(sb); 27 struct exfat_inode_info *ei = EXFAT_I(inode); 28 bool is_dir = (ei->type == TYPE_DIR) ? true : false; 29 30 if (inode->i_ino == EXFAT_ROOT_INO) 31 return 0; 32 33 /* 34 * If the inode is already unlinked, there is no need for updating it. 35 */ 36 if (ei->dir.dir == DIR_DELETED) 37 return 0; 38 39 if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1) 40 return 0; 41 42 exfat_set_volume_dirty(sb); 43 44 /* get the directory entry of given file or directory */ 45 if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES)) 46 return -EIO; 47 ep = exfat_get_dentry_cached(&es, ES_IDX_FILE); 48 ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM); 49 50 ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode)); 51 52 /* set FILE_INFO structure using the acquired struct exfat_dentry */ 53 exfat_set_entry_time(sbi, &ei->i_crtime, 54 &ep->dentry.file.create_tz, 55 &ep->dentry.file.create_time, 56 &ep->dentry.file.create_date, 57 &ep->dentry.file.create_time_cs); 58 exfat_set_entry_time(sbi, &inode->i_mtime, 59 &ep->dentry.file.modify_tz, 60 &ep->dentry.file.modify_time, 61 &ep->dentry.file.modify_date, 62 &ep->dentry.file.modify_time_cs); 63 exfat_set_entry_time(sbi, &inode->i_atime, 64 &ep->dentry.file.access_tz, 65 &ep->dentry.file.access_time, 66 &ep->dentry.file.access_date, 67 NULL); 68 69 /* File size should be zero if there is no cluster allocated */ 70 on_disk_size = i_size_read(inode); 71 72 if (ei->start_clu == EXFAT_EOF_CLUSTER) 73 on_disk_size = 0; 74 75 ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size); 76 ep2->dentry.stream.size = ep2->dentry.stream.valid_size; 77 if (on_disk_size) { 78 ep2->dentry.stream.flags = ei->flags; 79 ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu); 80 } else { 81 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN; 82 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER; 83 } 84 85 exfat_update_dir_chksum_with_entry_set(&es); 86 return exfat_put_dentry_set(&es, sync); 87 } 88 89 int exfat_write_inode(struct inode *inode, struct writeback_control *wbc) 90 { 91 int ret; 92 93 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 94 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 95 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 96 97 return ret; 98 } 99 100 void exfat_sync_inode(struct inode *inode) 101 { 102 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock); 103 __exfat_write_inode(inode, 1); 104 } 105 106 /* 107 * Input: inode, (logical) clu_offset, target allocation area 108 * Output: errcode, cluster number 109 * *clu = (~0), if it's unable to allocate a new cluster 110 */ 111 static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, 112 unsigned int *clu, int create) 113 { 114 int ret; 115 unsigned int last_clu; 116 struct exfat_chain new_clu; 117 struct super_block *sb = inode->i_sb; 118 struct exfat_sb_info *sbi = EXFAT_SB(sb); 119 struct exfat_inode_info *ei = EXFAT_I(inode); 120 unsigned int local_clu_offset = clu_offset; 121 unsigned int num_to_be_allocated = 0, num_clusters = 0; 122 123 if (ei->i_size_ondisk > 0) 124 num_clusters = 125 EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi); 126 127 if (clu_offset >= num_clusters) 128 num_to_be_allocated = clu_offset - num_clusters + 1; 129 130 if (!create && (num_to_be_allocated > 0)) { 131 *clu = EXFAT_EOF_CLUSTER; 132 return 0; 133 } 134 135 *clu = last_clu = ei->start_clu; 136 137 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 138 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 139 last_clu += clu_offset - 1; 140 141 if (clu_offset == num_clusters) 142 *clu = EXFAT_EOF_CLUSTER; 143 else 144 *clu += clu_offset; 145 } 146 } else if (ei->type == TYPE_FILE) { 147 unsigned int fclus = 0; 148 int err = exfat_get_cluster(inode, clu_offset, 149 &fclus, clu, &last_clu, 1); 150 if (err) 151 return -EIO; 152 153 clu_offset -= fclus; 154 } else { 155 /* hint information */ 156 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 157 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 158 clu_offset -= ei->hint_bmap.off; 159 /* hint_bmap.clu should be valid */ 160 WARN_ON(ei->hint_bmap.clu < 2); 161 *clu = ei->hint_bmap.clu; 162 } 163 164 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 165 last_clu = *clu; 166 if (exfat_get_next_cluster(sb, clu)) 167 return -EIO; 168 clu_offset--; 169 } 170 } 171 172 if (*clu == EXFAT_EOF_CLUSTER) { 173 exfat_set_volume_dirty(sb); 174 175 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? 176 EXFAT_EOF_CLUSTER : last_clu + 1; 177 new_clu.size = 0; 178 new_clu.flags = ei->flags; 179 180 /* allocate a cluster */ 181 if (num_to_be_allocated < 1) { 182 /* Broken FAT (i_sze > allocated FAT) */ 183 exfat_fs_error(sb, "broken FAT chain."); 184 return -EIO; 185 } 186 187 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu, 188 inode_needs_sync(inode)); 189 if (ret) 190 return ret; 191 192 if (new_clu.dir == EXFAT_EOF_CLUSTER || 193 new_clu.dir == EXFAT_FREE_CLUSTER) { 194 exfat_fs_error(sb, 195 "bogus cluster new allocated (last_clu : %u, new_clu : %u)", 196 last_clu, new_clu.dir); 197 return -EIO; 198 } 199 200 /* append to the FAT chain */ 201 if (last_clu == EXFAT_EOF_CLUSTER) { 202 if (new_clu.flags == ALLOC_FAT_CHAIN) 203 ei->flags = ALLOC_FAT_CHAIN; 204 ei->start_clu = new_clu.dir; 205 } else { 206 if (new_clu.flags != ei->flags) { 207 /* no-fat-chain bit is disabled, 208 * so fat-chain should be synced with 209 * alloc-bitmap 210 */ 211 exfat_chain_cont_cluster(sb, ei->start_clu, 212 num_clusters); 213 ei->flags = ALLOC_FAT_CHAIN; 214 } 215 if (new_clu.flags == ALLOC_FAT_CHAIN) 216 if (exfat_ent_set(sb, last_clu, new_clu.dir)) 217 return -EIO; 218 } 219 220 num_clusters += num_to_be_allocated; 221 *clu = new_clu.dir; 222 223 inode->i_blocks += 224 num_to_be_allocated << sbi->sect_per_clus_bits; 225 226 /* 227 * Move *clu pointer along FAT chains (hole care) because the 228 * caller of this function expect *clu to be the last cluster. 229 * This only works when num_to_be_allocated >= 2, 230 * *clu = (the first cluster of the allocated chain) => 231 * (the last cluster of ...) 232 */ 233 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 234 *clu += num_to_be_allocated - 1; 235 } else { 236 while (num_to_be_allocated > 1) { 237 if (exfat_get_next_cluster(sb, clu)) 238 return -EIO; 239 num_to_be_allocated--; 240 } 241 } 242 243 } 244 245 /* hint information */ 246 ei->hint_bmap.off = local_clu_offset; 247 ei->hint_bmap.clu = *clu; 248 249 return 0; 250 } 251 252 static int exfat_map_new_buffer(struct exfat_inode_info *ei, 253 struct buffer_head *bh, loff_t pos) 254 { 255 if (buffer_delay(bh) && pos > ei->i_size_aligned) 256 return -EIO; 257 set_buffer_new(bh); 258 259 /* 260 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 261 */ 262 if (ei->i_size_ondisk > ei->i_size_aligned) 263 ei->i_size_aligned = ei->i_size_ondisk; 264 return 0; 265 } 266 267 static int exfat_get_block(struct inode *inode, sector_t iblock, 268 struct buffer_head *bh_result, int create) 269 { 270 struct exfat_inode_info *ei = EXFAT_I(inode); 271 struct super_block *sb = inode->i_sb; 272 struct exfat_sb_info *sbi = EXFAT_SB(sb); 273 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 274 int err = 0; 275 unsigned long mapped_blocks = 0; 276 unsigned int cluster, sec_offset; 277 sector_t last_block; 278 sector_t phys = 0; 279 loff_t pos; 280 281 mutex_lock(&sbi->s_lock); 282 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 283 if (iblock >= last_block && !create) 284 goto done; 285 286 /* Is this block already allocated? */ 287 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 288 &cluster, create); 289 if (err) { 290 if (err != -ENOSPC) 291 exfat_fs_error_ratelimit(sb, 292 "failed to bmap (inode : %p iblock : %llu, err : %d)", 293 inode, (unsigned long long)iblock, err); 294 goto unlock_ret; 295 } 296 297 if (cluster == EXFAT_EOF_CLUSTER) 298 goto done; 299 300 /* sector offset in cluster */ 301 sec_offset = iblock & (sbi->sect_per_clus - 1); 302 303 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 304 mapped_blocks = sbi->sect_per_clus - sec_offset; 305 max_blocks = min(mapped_blocks, max_blocks); 306 307 /* Treat newly added block / cluster */ 308 if (iblock < last_block) 309 create = 0; 310 311 if (create || buffer_delay(bh_result)) { 312 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 313 if (ei->i_size_ondisk < pos) 314 ei->i_size_ondisk = pos; 315 } 316 317 if (create) { 318 err = exfat_map_new_buffer(ei, bh_result, pos); 319 if (err) { 320 exfat_fs_error(sb, 321 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 322 pos, ei->i_size_aligned); 323 goto unlock_ret; 324 } 325 } 326 327 if (buffer_delay(bh_result)) 328 clear_buffer_delay(bh_result); 329 map_bh(bh_result, sb, phys); 330 done: 331 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 332 unlock_ret: 333 mutex_unlock(&sbi->s_lock); 334 return err; 335 } 336 337 static int exfat_read_folio(struct file *file, struct folio *folio) 338 { 339 return mpage_read_folio(folio, exfat_get_block); 340 } 341 342 static void exfat_readahead(struct readahead_control *rac) 343 { 344 mpage_readahead(rac, exfat_get_block); 345 } 346 347 static int exfat_writepages(struct address_space *mapping, 348 struct writeback_control *wbc) 349 { 350 return mpage_writepages(mapping, wbc, exfat_get_block); 351 } 352 353 static void exfat_write_failed(struct address_space *mapping, loff_t to) 354 { 355 struct inode *inode = mapping->host; 356 357 if (to > i_size_read(inode)) { 358 truncate_pagecache(inode, i_size_read(inode)); 359 inode->i_mtime = inode->i_ctime = current_time(inode); 360 exfat_truncate(inode); 361 } 362 } 363 364 static int exfat_write_begin(struct file *file, struct address_space *mapping, 365 loff_t pos, unsigned int len, 366 struct page **pagep, void **fsdata) 367 { 368 int ret; 369 370 *pagep = NULL; 371 ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, 372 exfat_get_block, 373 &EXFAT_I(mapping->host)->i_size_ondisk); 374 375 if (ret < 0) 376 exfat_write_failed(mapping, pos+len); 377 378 return ret; 379 } 380 381 static int exfat_write_end(struct file *file, struct address_space *mapping, 382 loff_t pos, unsigned int len, unsigned int copied, 383 struct page *pagep, void *fsdata) 384 { 385 struct inode *inode = mapping->host; 386 struct exfat_inode_info *ei = EXFAT_I(inode); 387 int err; 388 389 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 390 391 if (ei->i_size_aligned < i_size_read(inode)) { 392 exfat_fs_error(inode->i_sb, 393 "invalid size(size(%llu) > aligned(%llu)\n", 394 i_size_read(inode), ei->i_size_aligned); 395 return -EIO; 396 } 397 398 if (err < len) 399 exfat_write_failed(mapping, pos+len); 400 401 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) { 402 inode->i_mtime = inode->i_ctime = current_time(inode); 403 ei->attr |= ATTR_ARCHIVE; 404 mark_inode_dirty(inode); 405 } 406 407 return err; 408 } 409 410 static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 411 { 412 struct address_space *mapping = iocb->ki_filp->f_mapping; 413 struct inode *inode = mapping->host; 414 loff_t size = iocb->ki_pos + iov_iter_count(iter); 415 int rw = iov_iter_rw(iter); 416 ssize_t ret; 417 418 if (rw == WRITE) { 419 /* 420 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 421 * so we need to update the ->i_size_aligned to block boundary. 422 * 423 * But we must fill the remaining area or hole by nul for 424 * updating ->i_size_aligned 425 * 426 * Return 0, and fallback to normal buffered write. 427 */ 428 if (EXFAT_I(inode)->i_size_aligned < size) 429 return 0; 430 } 431 432 /* 433 * Need to use the DIO_LOCKING for avoiding the race 434 * condition of exfat_get_block() and ->truncate(). 435 */ 436 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 437 if (ret < 0 && (rw & WRITE)) 438 exfat_write_failed(mapping, size); 439 return ret; 440 } 441 442 static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 443 { 444 sector_t blocknr; 445 446 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 447 down_read(&EXFAT_I(mapping->host)->truncate_lock); 448 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 449 up_read(&EXFAT_I(mapping->host)->truncate_lock); 450 return blocknr; 451 } 452 453 /* 454 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 455 * up to the end of the block which corresponds to `from'. 456 * This is required during truncate to physically zeroout the tail end 457 * of that block so it doesn't yield old data if the file is later grown. 458 * Also, avoid causing failure from fsx for cases of "data past EOF" 459 */ 460 int exfat_block_truncate_page(struct inode *inode, loff_t from) 461 { 462 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 463 } 464 465 static const struct address_space_operations exfat_aops = { 466 .dirty_folio = block_dirty_folio, 467 .invalidate_folio = block_invalidate_folio, 468 .read_folio = exfat_read_folio, 469 .readahead = exfat_readahead, 470 .writepages = exfat_writepages, 471 .write_begin = exfat_write_begin, 472 .write_end = exfat_write_end, 473 .direct_IO = exfat_direct_IO, 474 .bmap = exfat_aop_bmap, 475 .migrate_folio = buffer_migrate_folio, 476 }; 477 478 static inline unsigned long exfat_hash(loff_t i_pos) 479 { 480 return hash_32(i_pos, EXFAT_HASH_BITS); 481 } 482 483 void exfat_hash_inode(struct inode *inode, loff_t i_pos) 484 { 485 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 486 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 487 488 spin_lock(&sbi->inode_hash_lock); 489 EXFAT_I(inode)->i_pos = i_pos; 490 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 491 spin_unlock(&sbi->inode_hash_lock); 492 } 493 494 void exfat_unhash_inode(struct inode *inode) 495 { 496 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 497 498 spin_lock(&sbi->inode_hash_lock); 499 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 500 EXFAT_I(inode)->i_pos = 0; 501 spin_unlock(&sbi->inode_hash_lock); 502 } 503 504 struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 505 { 506 struct exfat_sb_info *sbi = EXFAT_SB(sb); 507 struct exfat_inode_info *info; 508 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 509 struct inode *inode = NULL; 510 511 spin_lock(&sbi->inode_hash_lock); 512 hlist_for_each_entry(info, head, i_hash_fat) { 513 WARN_ON(info->vfs_inode.i_sb != sb); 514 515 if (i_pos != info->i_pos) 516 continue; 517 inode = igrab(&info->vfs_inode); 518 if (inode) 519 break; 520 } 521 spin_unlock(&sbi->inode_hash_lock); 522 return inode; 523 } 524 525 /* doesn't deal with root inode */ 526 static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 527 { 528 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 529 struct exfat_inode_info *ei = EXFAT_I(inode); 530 loff_t size = info->size; 531 532 ei->dir = info->dir; 533 ei->entry = info->entry; 534 ei->attr = info->attr; 535 ei->start_clu = info->start_clu; 536 ei->flags = info->flags; 537 ei->type = info->type; 538 539 ei->version = 0; 540 ei->hint_stat.eidx = 0; 541 ei->hint_stat.clu = info->start_clu; 542 ei->hint_femp.eidx = EXFAT_HINT_NONE; 543 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 544 ei->i_pos = 0; 545 546 inode->i_uid = sbi->options.fs_uid; 547 inode->i_gid = sbi->options.fs_gid; 548 inode_inc_iversion(inode); 549 inode->i_generation = get_random_u32(); 550 551 if (info->attr & ATTR_SUBDIR) { /* directory */ 552 inode->i_generation &= ~1; 553 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 554 inode->i_op = &exfat_dir_inode_operations; 555 inode->i_fop = &exfat_dir_operations; 556 set_nlink(inode, info->num_subdirs); 557 } else { /* regular file */ 558 inode->i_generation |= 1; 559 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 560 inode->i_op = &exfat_file_inode_operations; 561 inode->i_fop = &exfat_file_operations; 562 inode->i_mapping->a_ops = &exfat_aops; 563 inode->i_mapping->nrpages = 0; 564 } 565 566 i_size_write(inode, size); 567 568 /* ondisk and aligned size should be aligned with block size */ 569 if (size & (inode->i_sb->s_blocksize - 1)) { 570 size |= (inode->i_sb->s_blocksize - 1); 571 size++; 572 } 573 574 ei->i_size_aligned = size; 575 ei->i_size_ondisk = size; 576 577 exfat_save_attr(inode, info->attr); 578 579 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 580 inode->i_blkbits; 581 inode->i_mtime = info->mtime; 582 inode->i_ctime = info->mtime; 583 ei->i_crtime = info->crtime; 584 inode->i_atime = info->atime; 585 586 return 0; 587 } 588 589 struct inode *exfat_build_inode(struct super_block *sb, 590 struct exfat_dir_entry *info, loff_t i_pos) 591 { 592 struct inode *inode; 593 int err; 594 595 inode = exfat_iget(sb, i_pos); 596 if (inode) 597 goto out; 598 inode = new_inode(sb); 599 if (!inode) { 600 inode = ERR_PTR(-ENOMEM); 601 goto out; 602 } 603 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 604 inode_set_iversion(inode, 1); 605 err = exfat_fill_inode(inode, info); 606 if (err) { 607 iput(inode); 608 inode = ERR_PTR(err); 609 goto out; 610 } 611 exfat_hash_inode(inode, i_pos); 612 insert_inode_hash(inode); 613 out: 614 return inode; 615 } 616 617 void exfat_evict_inode(struct inode *inode) 618 { 619 truncate_inode_pages(&inode->i_data, 0); 620 621 if (!inode->i_nlink) { 622 i_size_write(inode, 0); 623 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 624 __exfat_truncate(inode); 625 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 626 } 627 628 invalidate_inode_buffers(inode); 629 clear_inode(inode); 630 exfat_cache_inval_inode(inode); 631 exfat_unhash_inode(inode); 632 } 633