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 = NULL; 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 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES); 46 if (!es) 47 return -EIO; 48 ep = exfat_get_dentry_cached(es, 0); 49 ep2 = exfat_get_dentry_cached(es, 1); 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, &inode->i_mtime, 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 exfat_set_entry_time(sbi, &inode->i_atime, 65 &ep->dentry.file.access_tz, 66 &ep->dentry.file.access_time, 67 &ep->dentry.file.access_date, 68 NULL); 69 70 /* File size should be zero if there is no cluster allocated */ 71 on_disk_size = i_size_read(inode); 72 73 if (ei->start_clu == EXFAT_EOF_CLUSTER) 74 on_disk_size = 0; 75 76 ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size); 77 ep2->dentry.stream.size = ep2->dentry.stream.valid_size; 78 if (on_disk_size) { 79 ep2->dentry.stream.flags = ei->flags; 80 ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu); 81 } else { 82 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN; 83 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER; 84 } 85 86 exfat_update_dir_chksum_with_entry_set(es); 87 return exfat_free_dentry_set(es, sync); 88 } 89 90 int exfat_write_inode(struct inode *inode, struct writeback_control *wbc) 91 { 92 int ret; 93 94 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 95 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 96 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 97 98 return ret; 99 } 100 101 void exfat_sync_inode(struct inode *inode) 102 { 103 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock); 104 __exfat_write_inode(inode, 1); 105 } 106 107 /* 108 * Input: inode, (logical) clu_offset, target allocation area 109 * Output: errcode, cluster number 110 * *clu = (~0), if it's unable to allocate a new cluster 111 */ 112 static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, 113 unsigned int *clu, int create) 114 { 115 int ret; 116 unsigned int last_clu; 117 struct exfat_chain new_clu; 118 struct super_block *sb = inode->i_sb; 119 struct exfat_sb_info *sbi = EXFAT_SB(sb); 120 struct exfat_inode_info *ei = EXFAT_I(inode); 121 unsigned int local_clu_offset = clu_offset; 122 unsigned int num_to_be_allocated = 0, num_clusters = 0; 123 124 if (ei->i_size_ondisk > 0) 125 num_clusters = 126 EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi); 127 128 if (clu_offset >= num_clusters) 129 num_to_be_allocated = clu_offset - num_clusters + 1; 130 131 if (!create && (num_to_be_allocated > 0)) { 132 *clu = EXFAT_EOF_CLUSTER; 133 return 0; 134 } 135 136 *clu = last_clu = ei->start_clu; 137 138 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 139 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 140 last_clu += clu_offset - 1; 141 142 if (clu_offset == num_clusters) 143 *clu = EXFAT_EOF_CLUSTER; 144 else 145 *clu += clu_offset; 146 } 147 } else if (ei->type == TYPE_FILE) { 148 unsigned int fclus = 0; 149 int err = exfat_get_cluster(inode, clu_offset, 150 &fclus, clu, &last_clu, 1); 151 if (err) 152 return -EIO; 153 154 clu_offset -= fclus; 155 } else { 156 /* hint information */ 157 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 158 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 159 clu_offset -= ei->hint_bmap.off; 160 /* hint_bmap.clu should be valid */ 161 WARN_ON(ei->hint_bmap.clu < 2); 162 *clu = ei->hint_bmap.clu; 163 } 164 165 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 166 last_clu = *clu; 167 if (exfat_get_next_cluster(sb, clu)) 168 return -EIO; 169 clu_offset--; 170 } 171 } 172 173 if (*clu == EXFAT_EOF_CLUSTER) { 174 exfat_set_volume_dirty(sb); 175 176 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? 177 EXFAT_EOF_CLUSTER : last_clu + 1; 178 new_clu.size = 0; 179 new_clu.flags = ei->flags; 180 181 /* allocate a cluster */ 182 if (num_to_be_allocated < 1) { 183 /* Broken FAT (i_sze > allocated FAT) */ 184 exfat_fs_error(sb, "broken FAT chain."); 185 return -EIO; 186 } 187 188 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu, 189 inode_needs_sync(inode)); 190 if (ret) 191 return ret; 192 193 if (new_clu.dir == EXFAT_EOF_CLUSTER || 194 new_clu.dir == EXFAT_FREE_CLUSTER) { 195 exfat_fs_error(sb, 196 "bogus cluster new allocated (last_clu : %u, new_clu : %u)", 197 last_clu, new_clu.dir); 198 return -EIO; 199 } 200 201 /* append to the FAT chain */ 202 if (last_clu == EXFAT_EOF_CLUSTER) { 203 if (new_clu.flags == ALLOC_FAT_CHAIN) 204 ei->flags = ALLOC_FAT_CHAIN; 205 ei->start_clu = new_clu.dir; 206 } else { 207 if (new_clu.flags != ei->flags) { 208 /* no-fat-chain bit is disabled, 209 * so fat-chain should be synced with 210 * alloc-bitmap 211 */ 212 exfat_chain_cont_cluster(sb, ei->start_clu, 213 num_clusters); 214 ei->flags = ALLOC_FAT_CHAIN; 215 } 216 if (new_clu.flags == ALLOC_FAT_CHAIN) 217 if (exfat_ent_set(sb, last_clu, new_clu.dir)) 218 return -EIO; 219 } 220 221 num_clusters += num_to_be_allocated; 222 *clu = new_clu.dir; 223 224 inode->i_blocks += 225 num_to_be_allocated << sbi->sect_per_clus_bits; 226 227 /* 228 * Move *clu pointer along FAT chains (hole care) because the 229 * caller of this function expect *clu to be the last cluster. 230 * This only works when num_to_be_allocated >= 2, 231 * *clu = (the first cluster of the allocated chain) => 232 * (the last cluster of ...) 233 */ 234 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 235 *clu += num_to_be_allocated - 1; 236 } else { 237 while (num_to_be_allocated > 1) { 238 if (exfat_get_next_cluster(sb, clu)) 239 return -EIO; 240 num_to_be_allocated--; 241 } 242 } 243 244 } 245 246 /* hint information */ 247 ei->hint_bmap.off = local_clu_offset; 248 ei->hint_bmap.clu = *clu; 249 250 return 0; 251 } 252 253 static int exfat_map_new_buffer(struct exfat_inode_info *ei, 254 struct buffer_head *bh, loff_t pos) 255 { 256 if (buffer_delay(bh) && pos > ei->i_size_aligned) 257 return -EIO; 258 set_buffer_new(bh); 259 260 /* 261 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 262 */ 263 if (ei->i_size_ondisk > ei->i_size_aligned) 264 ei->i_size_aligned = ei->i_size_ondisk; 265 return 0; 266 } 267 268 static int exfat_get_block(struct inode *inode, sector_t iblock, 269 struct buffer_head *bh_result, int create) 270 { 271 struct exfat_inode_info *ei = EXFAT_I(inode); 272 struct super_block *sb = inode->i_sb; 273 struct exfat_sb_info *sbi = EXFAT_SB(sb); 274 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 275 int err = 0; 276 unsigned long mapped_blocks = 0; 277 unsigned int cluster, sec_offset; 278 sector_t last_block; 279 sector_t phys = 0; 280 loff_t pos; 281 282 mutex_lock(&sbi->s_lock); 283 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 284 if (iblock >= last_block && !create) 285 goto done; 286 287 /* Is this block already allocated? */ 288 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 289 &cluster, create); 290 if (err) { 291 if (err != -ENOSPC) 292 exfat_fs_error_ratelimit(sb, 293 "failed to bmap (inode : %p iblock : %llu, err : %d)", 294 inode, (unsigned long long)iblock, err); 295 goto unlock_ret; 296 } 297 298 if (cluster == EXFAT_EOF_CLUSTER) 299 goto done; 300 301 /* sector offset in cluster */ 302 sec_offset = iblock & (sbi->sect_per_clus - 1); 303 304 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 305 mapped_blocks = sbi->sect_per_clus - sec_offset; 306 max_blocks = min(mapped_blocks, max_blocks); 307 308 /* Treat newly added block / cluster */ 309 if (iblock < last_block) 310 create = 0; 311 312 if (create || buffer_delay(bh_result)) { 313 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 314 if (ei->i_size_ondisk < pos) 315 ei->i_size_ondisk = pos; 316 } 317 318 if (create) { 319 err = exfat_map_new_buffer(ei, bh_result, pos); 320 if (err) { 321 exfat_fs_error(sb, 322 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 323 pos, ei->i_size_aligned); 324 goto unlock_ret; 325 } 326 } 327 328 if (buffer_delay(bh_result)) 329 clear_buffer_delay(bh_result); 330 map_bh(bh_result, sb, phys); 331 done: 332 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 333 unlock_ret: 334 mutex_unlock(&sbi->s_lock); 335 return err; 336 } 337 338 static int exfat_read_folio(struct file *file, struct folio *folio) 339 { 340 return mpage_read_folio(folio, exfat_get_block); 341 } 342 343 static void exfat_readahead(struct readahead_control *rac) 344 { 345 mpage_readahead(rac, exfat_get_block); 346 } 347 348 static int exfat_writepage(struct page *page, struct writeback_control *wbc) 349 { 350 return block_write_full_page(page, exfat_get_block, wbc); 351 } 352 353 static int exfat_writepages(struct address_space *mapping, 354 struct writeback_control *wbc) 355 { 356 return mpage_writepages(mapping, wbc, exfat_get_block); 357 } 358 359 static void exfat_write_failed(struct address_space *mapping, loff_t to) 360 { 361 struct inode *inode = mapping->host; 362 363 if (to > i_size_read(inode)) { 364 truncate_pagecache(inode, i_size_read(inode)); 365 inode->i_mtime = inode->i_ctime = current_time(inode); 366 exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned); 367 } 368 } 369 370 static int exfat_write_begin(struct file *file, struct address_space *mapping, 371 loff_t pos, unsigned int len, 372 struct page **pagep, void **fsdata) 373 { 374 int ret; 375 376 *pagep = NULL; 377 ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, 378 exfat_get_block, 379 &EXFAT_I(mapping->host)->i_size_ondisk); 380 381 if (ret < 0) 382 exfat_write_failed(mapping, pos+len); 383 384 return ret; 385 } 386 387 static int exfat_write_end(struct file *file, struct address_space *mapping, 388 loff_t pos, unsigned int len, unsigned int copied, 389 struct page *pagep, void *fsdata) 390 { 391 struct inode *inode = mapping->host; 392 struct exfat_inode_info *ei = EXFAT_I(inode); 393 int err; 394 395 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 396 397 if (ei->i_size_aligned < i_size_read(inode)) { 398 exfat_fs_error(inode->i_sb, 399 "invalid size(size(%llu) > aligned(%llu)\n", 400 i_size_read(inode), ei->i_size_aligned); 401 return -EIO; 402 } 403 404 if (err < len) 405 exfat_write_failed(mapping, pos+len); 406 407 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) { 408 inode->i_mtime = inode->i_ctime = current_time(inode); 409 ei->attr |= ATTR_ARCHIVE; 410 mark_inode_dirty(inode); 411 } 412 413 return err; 414 } 415 416 static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 417 { 418 struct address_space *mapping = iocb->ki_filp->f_mapping; 419 struct inode *inode = mapping->host; 420 loff_t size = iocb->ki_pos + iov_iter_count(iter); 421 int rw = iov_iter_rw(iter); 422 ssize_t ret; 423 424 if (rw == WRITE) { 425 /* 426 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 427 * so we need to update the ->i_size_aligned to block boundary. 428 * 429 * But we must fill the remaining area or hole by nul for 430 * updating ->i_size_aligned 431 * 432 * Return 0, and fallback to normal buffered write. 433 */ 434 if (EXFAT_I(inode)->i_size_aligned < size) 435 return 0; 436 } 437 438 /* 439 * Need to use the DIO_LOCKING for avoiding the race 440 * condition of exfat_get_block() and ->truncate(). 441 */ 442 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 443 if (ret < 0 && (rw & WRITE)) 444 exfat_write_failed(mapping, size); 445 return ret; 446 } 447 448 static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 449 { 450 sector_t blocknr; 451 452 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 453 down_read(&EXFAT_I(mapping->host)->truncate_lock); 454 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 455 up_read(&EXFAT_I(mapping->host)->truncate_lock); 456 return blocknr; 457 } 458 459 /* 460 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 461 * up to the end of the block which corresponds to `from'. 462 * This is required during truncate to physically zeroout the tail end 463 * of that block so it doesn't yield old data if the file is later grown. 464 * Also, avoid causing failure from fsx for cases of "data past EOF" 465 */ 466 int exfat_block_truncate_page(struct inode *inode, loff_t from) 467 { 468 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 469 } 470 471 static const struct address_space_operations exfat_aops = { 472 .dirty_folio = block_dirty_folio, 473 .invalidate_folio = block_invalidate_folio, 474 .read_folio = exfat_read_folio, 475 .readahead = exfat_readahead, 476 .writepage = exfat_writepage, 477 .writepages = exfat_writepages, 478 .write_begin = exfat_write_begin, 479 .write_end = exfat_write_end, 480 .direct_IO = exfat_direct_IO, 481 .bmap = exfat_aop_bmap 482 }; 483 484 static inline unsigned long exfat_hash(loff_t i_pos) 485 { 486 return hash_32(i_pos, EXFAT_HASH_BITS); 487 } 488 489 void exfat_hash_inode(struct inode *inode, loff_t i_pos) 490 { 491 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 492 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 493 494 spin_lock(&sbi->inode_hash_lock); 495 EXFAT_I(inode)->i_pos = i_pos; 496 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 497 spin_unlock(&sbi->inode_hash_lock); 498 } 499 500 void exfat_unhash_inode(struct inode *inode) 501 { 502 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 503 504 spin_lock(&sbi->inode_hash_lock); 505 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 506 EXFAT_I(inode)->i_pos = 0; 507 spin_unlock(&sbi->inode_hash_lock); 508 } 509 510 struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 511 { 512 struct exfat_sb_info *sbi = EXFAT_SB(sb); 513 struct exfat_inode_info *info; 514 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 515 struct inode *inode = NULL; 516 517 spin_lock(&sbi->inode_hash_lock); 518 hlist_for_each_entry(info, head, i_hash_fat) { 519 WARN_ON(info->vfs_inode.i_sb != sb); 520 521 if (i_pos != info->i_pos) 522 continue; 523 inode = igrab(&info->vfs_inode); 524 if (inode) 525 break; 526 } 527 spin_unlock(&sbi->inode_hash_lock); 528 return inode; 529 } 530 531 /* doesn't deal with root inode */ 532 static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 533 { 534 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 535 struct exfat_inode_info *ei = EXFAT_I(inode); 536 loff_t size = info->size; 537 538 ei->dir = info->dir; 539 ei->entry = info->entry; 540 ei->attr = info->attr; 541 ei->start_clu = info->start_clu; 542 ei->flags = info->flags; 543 ei->type = info->type; 544 545 ei->version = 0; 546 ei->hint_stat.eidx = 0; 547 ei->hint_stat.clu = info->start_clu; 548 ei->hint_femp.eidx = EXFAT_HINT_NONE; 549 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 550 ei->i_pos = 0; 551 552 inode->i_uid = sbi->options.fs_uid; 553 inode->i_gid = sbi->options.fs_gid; 554 inode_inc_iversion(inode); 555 inode->i_generation = prandom_u32(); 556 557 if (info->attr & ATTR_SUBDIR) { /* directory */ 558 inode->i_generation &= ~1; 559 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 560 inode->i_op = &exfat_dir_inode_operations; 561 inode->i_fop = &exfat_dir_operations; 562 set_nlink(inode, info->num_subdirs); 563 } else { /* regular file */ 564 inode->i_generation |= 1; 565 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 566 inode->i_op = &exfat_file_inode_operations; 567 inode->i_fop = &exfat_file_operations; 568 inode->i_mapping->a_ops = &exfat_aops; 569 inode->i_mapping->nrpages = 0; 570 } 571 572 i_size_write(inode, size); 573 574 /* ondisk and aligned size should be aligned with block size */ 575 if (size & (inode->i_sb->s_blocksize - 1)) { 576 size |= (inode->i_sb->s_blocksize - 1); 577 size++; 578 } 579 580 ei->i_size_aligned = size; 581 ei->i_size_ondisk = size; 582 583 exfat_save_attr(inode, info->attr); 584 585 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 586 inode->i_blkbits; 587 inode->i_mtime = info->mtime; 588 inode->i_ctime = info->mtime; 589 ei->i_crtime = info->crtime; 590 inode->i_atime = info->atime; 591 592 return 0; 593 } 594 595 struct inode *exfat_build_inode(struct super_block *sb, 596 struct exfat_dir_entry *info, loff_t i_pos) 597 { 598 struct inode *inode; 599 int err; 600 601 inode = exfat_iget(sb, i_pos); 602 if (inode) 603 goto out; 604 inode = new_inode(sb); 605 if (!inode) { 606 inode = ERR_PTR(-ENOMEM); 607 goto out; 608 } 609 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 610 inode_set_iversion(inode, 1); 611 err = exfat_fill_inode(inode, info); 612 if (err) { 613 iput(inode); 614 inode = ERR_PTR(err); 615 goto out; 616 } 617 exfat_hash_inode(inode, i_pos); 618 insert_inode_hash(inode); 619 out: 620 return inode; 621 } 622 623 void exfat_evict_inode(struct inode *inode) 624 { 625 truncate_inode_pages(&inode->i_data, 0); 626 627 if (!inode->i_nlink) { 628 i_size_write(inode, 0); 629 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 630 __exfat_truncate(inode, 0); 631 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 632 } 633 634 invalidate_inode_buffers(inode); 635 clear_inode(inode); 636 exfat_cache_inval_inode(inode); 637 exfat_unhash_inode(inode); 638 } 639