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 struct timespec64 ts; 30 31 if (inode->i_ino == EXFAT_ROOT_INO) 32 return 0; 33 34 /* 35 * If the inode is already unlinked, there is no need for updating it. 36 */ 37 if (ei->dir.dir == DIR_DELETED) 38 return 0; 39 40 if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1) 41 return 0; 42 43 exfat_set_volume_dirty(sb); 44 45 /* get the directory entry of given file or directory */ 46 if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES)) 47 return -EIO; 48 ep = exfat_get_dentry_cached(&es, ES_IDX_FILE); 49 ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM); 50 51 ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode)); 52 53 /* set FILE_INFO structure using the acquired struct exfat_dentry */ 54 exfat_set_entry_time(sbi, &ei->i_crtime, 55 &ep->dentry.file.create_tz, 56 &ep->dentry.file.create_time, 57 &ep->dentry.file.create_date, 58 &ep->dentry.file.create_time_cs); 59 exfat_set_entry_time(sbi, &ts, 60 &ep->dentry.file.modify_tz, 61 &ep->dentry.file.modify_time, 62 &ep->dentry.file.modify_date, 63 &ep->dentry.file.modify_time_cs); 64 inode_set_mtime_to_ts(inode, ts); 65 exfat_set_entry_time(sbi, &ts, 66 &ep->dentry.file.access_tz, 67 &ep->dentry.file.access_time, 68 &ep->dentry.file.access_date, 69 NULL); 70 inode_set_atime_to_ts(inode, ts); 71 72 /* File size should be zero if there is no cluster allocated */ 73 on_disk_size = i_size_read(inode); 74 75 if (ei->start_clu == EXFAT_EOF_CLUSTER) 76 on_disk_size = 0; 77 78 ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size); 79 ep2->dentry.stream.size = ep2->dentry.stream.valid_size; 80 if (on_disk_size) { 81 ep2->dentry.stream.flags = ei->flags; 82 ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu); 83 } else { 84 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN; 85 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER; 86 } 87 88 exfat_update_dir_chksum_with_entry_set(&es); 89 return exfat_put_dentry_set(&es, sync); 90 } 91 92 int exfat_write_inode(struct inode *inode, struct writeback_control *wbc) 93 { 94 int ret; 95 96 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 97 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 98 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 99 100 return ret; 101 } 102 103 void exfat_sync_inode(struct inode *inode) 104 { 105 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock); 106 __exfat_write_inode(inode, 1); 107 } 108 109 /* 110 * Input: inode, (logical) clu_offset, target allocation area 111 * Output: errcode, cluster number 112 * *clu = (~0), if it's unable to allocate a new cluster 113 */ 114 static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, 115 unsigned int *clu, int create) 116 { 117 int ret; 118 unsigned int last_clu; 119 struct exfat_chain new_clu; 120 struct super_block *sb = inode->i_sb; 121 struct exfat_sb_info *sbi = EXFAT_SB(sb); 122 struct exfat_inode_info *ei = EXFAT_I(inode); 123 unsigned int local_clu_offset = clu_offset; 124 unsigned int num_to_be_allocated = 0, num_clusters = 0; 125 126 if (ei->i_size_ondisk > 0) 127 num_clusters = 128 EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi); 129 130 if (clu_offset >= num_clusters) 131 num_to_be_allocated = clu_offset - num_clusters + 1; 132 133 if (!create && (num_to_be_allocated > 0)) { 134 *clu = EXFAT_EOF_CLUSTER; 135 return 0; 136 } 137 138 *clu = last_clu = ei->start_clu; 139 140 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 141 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 142 last_clu += clu_offset - 1; 143 144 if (clu_offset == num_clusters) 145 *clu = EXFAT_EOF_CLUSTER; 146 else 147 *clu += clu_offset; 148 } 149 } else if (ei->type == TYPE_FILE) { 150 unsigned int fclus = 0; 151 int err = exfat_get_cluster(inode, clu_offset, 152 &fclus, clu, &last_clu, 1); 153 if (err) 154 return -EIO; 155 156 clu_offset -= fclus; 157 } else { 158 /* hint information */ 159 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 160 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 161 clu_offset -= ei->hint_bmap.off; 162 /* hint_bmap.clu should be valid */ 163 WARN_ON(ei->hint_bmap.clu < 2); 164 *clu = ei->hint_bmap.clu; 165 } 166 167 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 168 last_clu = *clu; 169 if (exfat_get_next_cluster(sb, clu)) 170 return -EIO; 171 clu_offset--; 172 } 173 } 174 175 if (*clu == EXFAT_EOF_CLUSTER) { 176 exfat_set_volume_dirty(sb); 177 178 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? 179 EXFAT_EOF_CLUSTER : last_clu + 1; 180 new_clu.size = 0; 181 new_clu.flags = ei->flags; 182 183 /* allocate a cluster */ 184 if (num_to_be_allocated < 1) { 185 /* Broken FAT (i_sze > allocated FAT) */ 186 exfat_fs_error(sb, "broken FAT chain."); 187 return -EIO; 188 } 189 190 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu, 191 inode_needs_sync(inode)); 192 if (ret) 193 return ret; 194 195 if (new_clu.dir == EXFAT_EOF_CLUSTER || 196 new_clu.dir == EXFAT_FREE_CLUSTER) { 197 exfat_fs_error(sb, 198 "bogus cluster new allocated (last_clu : %u, new_clu : %u)", 199 last_clu, new_clu.dir); 200 return -EIO; 201 } 202 203 /* append to the FAT chain */ 204 if (last_clu == EXFAT_EOF_CLUSTER) { 205 if (new_clu.flags == ALLOC_FAT_CHAIN) 206 ei->flags = ALLOC_FAT_CHAIN; 207 ei->start_clu = new_clu.dir; 208 } else { 209 if (new_clu.flags != ei->flags) { 210 /* no-fat-chain bit is disabled, 211 * so fat-chain should be synced with 212 * alloc-bitmap 213 */ 214 exfat_chain_cont_cluster(sb, ei->start_clu, 215 num_clusters); 216 ei->flags = ALLOC_FAT_CHAIN; 217 } 218 if (new_clu.flags == ALLOC_FAT_CHAIN) 219 if (exfat_ent_set(sb, last_clu, new_clu.dir)) 220 return -EIO; 221 } 222 223 num_clusters += num_to_be_allocated; 224 *clu = new_clu.dir; 225 226 inode->i_blocks += EXFAT_CLU_TO_B(num_to_be_allocated, sbi) >> 9; 227 228 /* 229 * Move *clu pointer along FAT chains (hole care) because the 230 * caller of this function expect *clu to be the last cluster. 231 * This only works when num_to_be_allocated >= 2, 232 * *clu = (the first cluster of the allocated chain) => 233 * (the last cluster of ...) 234 */ 235 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 236 *clu += num_to_be_allocated - 1; 237 } else { 238 while (num_to_be_allocated > 1) { 239 if (exfat_get_next_cluster(sb, clu)) 240 return -EIO; 241 num_to_be_allocated--; 242 } 243 } 244 245 } 246 247 /* hint information */ 248 ei->hint_bmap.off = local_clu_offset; 249 ei->hint_bmap.clu = *clu; 250 251 return 0; 252 } 253 254 static int exfat_map_new_buffer(struct exfat_inode_info *ei, 255 struct buffer_head *bh, loff_t pos) 256 { 257 if (buffer_delay(bh) && pos > ei->i_size_aligned) 258 return -EIO; 259 set_buffer_new(bh); 260 261 /* 262 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 263 */ 264 if (ei->i_size_ondisk > ei->i_size_aligned) 265 ei->i_size_aligned = ei->i_size_ondisk; 266 return 0; 267 } 268 269 static int exfat_get_block(struct inode *inode, sector_t iblock, 270 struct buffer_head *bh_result, int create) 271 { 272 struct exfat_inode_info *ei = EXFAT_I(inode); 273 struct super_block *sb = inode->i_sb; 274 struct exfat_sb_info *sbi = EXFAT_SB(sb); 275 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 276 int err = 0; 277 unsigned long mapped_blocks = 0; 278 unsigned int cluster, sec_offset; 279 sector_t last_block; 280 sector_t phys = 0; 281 loff_t pos; 282 283 mutex_lock(&sbi->s_lock); 284 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 285 if (iblock >= last_block && !create) 286 goto done; 287 288 /* Is this block already allocated? */ 289 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 290 &cluster, create); 291 if (err) { 292 if (err != -ENOSPC) 293 exfat_fs_error_ratelimit(sb, 294 "failed to bmap (inode : %p iblock : %llu, err : %d)", 295 inode, (unsigned long long)iblock, err); 296 goto unlock_ret; 297 } 298 299 if (cluster == EXFAT_EOF_CLUSTER) 300 goto done; 301 302 /* sector offset in cluster */ 303 sec_offset = iblock & (sbi->sect_per_clus - 1); 304 305 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 306 mapped_blocks = sbi->sect_per_clus - sec_offset; 307 max_blocks = min(mapped_blocks, max_blocks); 308 309 /* Treat newly added block / cluster */ 310 if (iblock < last_block) 311 create = 0; 312 313 if (create || buffer_delay(bh_result)) { 314 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 315 if (ei->i_size_ondisk < pos) 316 ei->i_size_ondisk = pos; 317 } 318 319 if (create) { 320 err = exfat_map_new_buffer(ei, bh_result, pos); 321 if (err) { 322 exfat_fs_error(sb, 323 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 324 pos, ei->i_size_aligned); 325 goto unlock_ret; 326 } 327 } 328 329 if (buffer_delay(bh_result)) 330 clear_buffer_delay(bh_result); 331 map_bh(bh_result, sb, phys); 332 done: 333 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 334 unlock_ret: 335 mutex_unlock(&sbi->s_lock); 336 return err; 337 } 338 339 static int exfat_read_folio(struct file *file, struct folio *folio) 340 { 341 return mpage_read_folio(folio, exfat_get_block); 342 } 343 344 static void exfat_readahead(struct readahead_control *rac) 345 { 346 mpage_readahead(rac, exfat_get_block); 347 } 348 349 static int exfat_writepages(struct address_space *mapping, 350 struct writeback_control *wbc) 351 { 352 return mpage_writepages(mapping, wbc, exfat_get_block); 353 } 354 355 static void exfat_write_failed(struct address_space *mapping, loff_t to) 356 { 357 struct inode *inode = mapping->host; 358 359 if (to > i_size_read(inode)) { 360 truncate_pagecache(inode, i_size_read(inode)); 361 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); 362 exfat_truncate(inode); 363 } 364 } 365 366 static int exfat_write_begin(struct file *file, struct address_space *mapping, 367 loff_t pos, unsigned int len, 368 struct page **pagep, void **fsdata) 369 { 370 int ret; 371 372 *pagep = NULL; 373 ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, 374 exfat_get_block, 375 &EXFAT_I(mapping->host)->i_size_ondisk); 376 377 if (ret < 0) 378 exfat_write_failed(mapping, pos+len); 379 380 return ret; 381 } 382 383 static int exfat_write_end(struct file *file, struct address_space *mapping, 384 loff_t pos, unsigned int len, unsigned int copied, 385 struct page *pagep, void *fsdata) 386 { 387 struct inode *inode = mapping->host; 388 struct exfat_inode_info *ei = EXFAT_I(inode); 389 int err; 390 391 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 392 393 if (ei->i_size_aligned < i_size_read(inode)) { 394 exfat_fs_error(inode->i_sb, 395 "invalid size(size(%llu) > aligned(%llu)\n", 396 i_size_read(inode), ei->i_size_aligned); 397 return -EIO; 398 } 399 400 if (err < len) 401 exfat_write_failed(mapping, pos+len); 402 403 if (!(err < 0) && !(ei->attr & EXFAT_ATTR_ARCHIVE)) { 404 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); 405 ei->attr |= EXFAT_ATTR_ARCHIVE; 406 mark_inode_dirty(inode); 407 } 408 409 return err; 410 } 411 412 static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 413 { 414 struct address_space *mapping = iocb->ki_filp->f_mapping; 415 struct inode *inode = mapping->host; 416 loff_t size = iocb->ki_pos + iov_iter_count(iter); 417 int rw = iov_iter_rw(iter); 418 ssize_t ret; 419 420 if (rw == WRITE) { 421 /* 422 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 423 * so we need to update the ->i_size_aligned to block boundary. 424 * 425 * But we must fill the remaining area or hole by nul for 426 * updating ->i_size_aligned 427 * 428 * Return 0, and fallback to normal buffered write. 429 */ 430 if (EXFAT_I(inode)->i_size_aligned < size) 431 return 0; 432 } 433 434 /* 435 * Need to use the DIO_LOCKING for avoiding the race 436 * condition of exfat_get_block() and ->truncate(). 437 */ 438 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 439 if (ret < 0 && (rw & WRITE)) 440 exfat_write_failed(mapping, size); 441 return ret; 442 } 443 444 static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 445 { 446 sector_t blocknr; 447 448 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 449 down_read(&EXFAT_I(mapping->host)->truncate_lock); 450 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 451 up_read(&EXFAT_I(mapping->host)->truncate_lock); 452 return blocknr; 453 } 454 455 /* 456 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 457 * up to the end of the block which corresponds to `from'. 458 * This is required during truncate to physically zeroout the tail end 459 * of that block so it doesn't yield old data if the file is later grown. 460 * Also, avoid causing failure from fsx for cases of "data past EOF" 461 */ 462 int exfat_block_truncate_page(struct inode *inode, loff_t from) 463 { 464 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 465 } 466 467 static const struct address_space_operations exfat_aops = { 468 .dirty_folio = block_dirty_folio, 469 .invalidate_folio = block_invalidate_folio, 470 .read_folio = exfat_read_folio, 471 .readahead = exfat_readahead, 472 .writepages = exfat_writepages, 473 .write_begin = exfat_write_begin, 474 .write_end = exfat_write_end, 475 .direct_IO = exfat_direct_IO, 476 .bmap = exfat_aop_bmap, 477 .migrate_folio = buffer_migrate_folio, 478 }; 479 480 static inline unsigned long exfat_hash(loff_t i_pos) 481 { 482 return hash_32(i_pos, EXFAT_HASH_BITS); 483 } 484 485 void exfat_hash_inode(struct inode *inode, loff_t i_pos) 486 { 487 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 488 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 489 490 spin_lock(&sbi->inode_hash_lock); 491 EXFAT_I(inode)->i_pos = i_pos; 492 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 493 spin_unlock(&sbi->inode_hash_lock); 494 } 495 496 void exfat_unhash_inode(struct inode *inode) 497 { 498 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 499 500 spin_lock(&sbi->inode_hash_lock); 501 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 502 EXFAT_I(inode)->i_pos = 0; 503 spin_unlock(&sbi->inode_hash_lock); 504 } 505 506 struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 507 { 508 struct exfat_sb_info *sbi = EXFAT_SB(sb); 509 struct exfat_inode_info *info; 510 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 511 struct inode *inode = NULL; 512 513 spin_lock(&sbi->inode_hash_lock); 514 hlist_for_each_entry(info, head, i_hash_fat) { 515 WARN_ON(info->vfs_inode.i_sb != sb); 516 517 if (i_pos != info->i_pos) 518 continue; 519 inode = igrab(&info->vfs_inode); 520 if (inode) 521 break; 522 } 523 spin_unlock(&sbi->inode_hash_lock); 524 return inode; 525 } 526 527 /* doesn't deal with root inode */ 528 static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 529 { 530 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 531 struct exfat_inode_info *ei = EXFAT_I(inode); 532 loff_t size = info->size; 533 534 ei->dir = info->dir; 535 ei->entry = info->entry; 536 ei->attr = info->attr; 537 ei->start_clu = info->start_clu; 538 ei->flags = info->flags; 539 ei->type = info->type; 540 541 ei->version = 0; 542 ei->hint_stat.eidx = 0; 543 ei->hint_stat.clu = info->start_clu; 544 ei->hint_femp.eidx = EXFAT_HINT_NONE; 545 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 546 ei->i_pos = 0; 547 548 inode->i_uid = sbi->options.fs_uid; 549 inode->i_gid = sbi->options.fs_gid; 550 inode_inc_iversion(inode); 551 inode->i_generation = get_random_u32(); 552 553 if (info->attr & EXFAT_ATTR_SUBDIR) { /* directory */ 554 inode->i_generation &= ~1; 555 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 556 inode->i_op = &exfat_dir_inode_operations; 557 inode->i_fop = &exfat_dir_operations; 558 set_nlink(inode, info->num_subdirs); 559 } else { /* regular file */ 560 inode->i_generation |= 1; 561 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 562 inode->i_op = &exfat_file_inode_operations; 563 inode->i_fop = &exfat_file_operations; 564 inode->i_mapping->a_ops = &exfat_aops; 565 inode->i_mapping->nrpages = 0; 566 } 567 568 i_size_write(inode, size); 569 570 /* ondisk and aligned size should be aligned with block size */ 571 if (size & (inode->i_sb->s_blocksize - 1)) { 572 size |= (inode->i_sb->s_blocksize - 1); 573 size++; 574 } 575 576 ei->i_size_aligned = size; 577 ei->i_size_ondisk = size; 578 579 exfat_save_attr(inode, info->attr); 580 581 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 582 inode_set_mtime_to_ts(inode, info->mtime); 583 inode_set_ctime_to_ts(inode, info->mtime); 584 ei->i_crtime = info->crtime; 585 inode_set_atime_to_ts(inode, info->atime); 586 587 return 0; 588 } 589 590 struct inode *exfat_build_inode(struct super_block *sb, 591 struct exfat_dir_entry *info, loff_t i_pos) 592 { 593 struct inode *inode; 594 int err; 595 596 inode = exfat_iget(sb, i_pos); 597 if (inode) 598 goto out; 599 inode = new_inode(sb); 600 if (!inode) { 601 inode = ERR_PTR(-ENOMEM); 602 goto out; 603 } 604 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 605 inode_set_iversion(inode, 1); 606 err = exfat_fill_inode(inode, info); 607 if (err) { 608 iput(inode); 609 inode = ERR_PTR(err); 610 goto out; 611 } 612 exfat_hash_inode(inode, i_pos); 613 insert_inode_hash(inode); 614 out: 615 return inode; 616 } 617 618 void exfat_evict_inode(struct inode *inode) 619 { 620 truncate_inode_pages(&inode->i_data, 0); 621 622 if (!inode->i_nlink) { 623 i_size_write(inode, 0); 624 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 625 __exfat_truncate(inode); 626 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 627 } 628 629 invalidate_inode_buffers(inode); 630 clear_inode(inode); 631 exfat_cache_inval_inode(inode); 632 exfat_unhash_inode(inode); 633 } 634