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 static 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 indode 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 79 exfat_update_dir_chksum_with_entry_set(es); 80 return exfat_free_dentry_set(es, sync); 81 } 82 83 int exfat_write_inode(struct inode *inode, struct writeback_control *wbc) 84 { 85 int ret; 86 87 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 88 ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 89 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 90 91 return ret; 92 } 93 94 void exfat_sync_inode(struct inode *inode) 95 { 96 lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock); 97 __exfat_write_inode(inode, 1); 98 } 99 100 /* 101 * Input: inode, (logical) clu_offset, target allocation area 102 * Output: errcode, cluster number 103 * *clu = (~0), if it's unable to allocate a new cluster 104 */ 105 static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, 106 unsigned int *clu, int create) 107 { 108 int ret, modified = false; 109 unsigned int last_clu; 110 struct exfat_chain new_clu; 111 struct super_block *sb = inode->i_sb; 112 struct exfat_sb_info *sbi = EXFAT_SB(sb); 113 struct exfat_inode_info *ei = EXFAT_I(inode); 114 unsigned int local_clu_offset = clu_offset; 115 unsigned int num_to_be_allocated = 0, num_clusters = 0; 116 117 if (EXFAT_I(inode)->i_size_ondisk > 0) 118 num_clusters = 119 EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, 120 sbi); 121 122 if (clu_offset >= num_clusters) 123 num_to_be_allocated = clu_offset - num_clusters + 1; 124 125 if (!create && (num_to_be_allocated > 0)) { 126 *clu = EXFAT_EOF_CLUSTER; 127 return 0; 128 } 129 130 *clu = last_clu = ei->start_clu; 131 132 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 133 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 134 last_clu += clu_offset - 1; 135 136 if (clu_offset == num_clusters) 137 *clu = EXFAT_EOF_CLUSTER; 138 else 139 *clu += clu_offset; 140 } 141 } else if (ei->type == TYPE_FILE) { 142 unsigned int fclus = 0; 143 int err = exfat_get_cluster(inode, clu_offset, 144 &fclus, clu, &last_clu, 1); 145 if (err) 146 return -EIO; 147 148 clu_offset -= fclus; 149 } else { 150 /* hint information */ 151 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 152 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 153 clu_offset -= ei->hint_bmap.off; 154 /* hint_bmap.clu should be valid */ 155 WARN_ON(ei->hint_bmap.clu < 2); 156 *clu = ei->hint_bmap.clu; 157 } 158 159 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 160 last_clu = *clu; 161 if (exfat_get_next_cluster(sb, clu)) 162 return -EIO; 163 clu_offset--; 164 } 165 } 166 167 if (*clu == EXFAT_EOF_CLUSTER) { 168 exfat_set_volume_dirty(sb); 169 170 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? 171 EXFAT_EOF_CLUSTER : last_clu + 1; 172 new_clu.size = 0; 173 new_clu.flags = ei->flags; 174 175 /* allocate a cluster */ 176 if (num_to_be_allocated < 1) { 177 /* Broken FAT (i_sze > allocated FAT) */ 178 exfat_fs_error(sb, "broken FAT chain."); 179 return -EIO; 180 } 181 182 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu); 183 if (ret) 184 return ret; 185 186 if (new_clu.dir == EXFAT_EOF_CLUSTER || 187 new_clu.dir == EXFAT_FREE_CLUSTER) { 188 exfat_fs_error(sb, 189 "bogus cluster new allocated (last_clu : %u, new_clu : %u)", 190 last_clu, new_clu.dir); 191 return -EIO; 192 } 193 194 /* append to the FAT chain */ 195 if (last_clu == EXFAT_EOF_CLUSTER) { 196 if (new_clu.flags == ALLOC_FAT_CHAIN) 197 ei->flags = ALLOC_FAT_CHAIN; 198 ei->start_clu = new_clu.dir; 199 modified = true; 200 } else { 201 if (new_clu.flags != ei->flags) { 202 /* no-fat-chain bit is disabled, 203 * so fat-chain should be synced with 204 * alloc-bitmap 205 */ 206 exfat_chain_cont_cluster(sb, ei->start_clu, 207 num_clusters); 208 ei->flags = ALLOC_FAT_CHAIN; 209 modified = true; 210 } 211 if (new_clu.flags == ALLOC_FAT_CHAIN) 212 if (exfat_ent_set(sb, last_clu, new_clu.dir)) 213 return -EIO; 214 } 215 216 num_clusters += num_to_be_allocated; 217 *clu = new_clu.dir; 218 219 if (ei->dir.dir != DIR_DELETED && modified) { 220 struct exfat_dentry *ep; 221 struct exfat_entry_set_cache *es; 222 int err; 223 224 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, 225 ES_ALL_ENTRIES); 226 if (!es) 227 return -EIO; 228 /* get stream entry */ 229 ep = exfat_get_dentry_cached(es, 1); 230 231 /* update directory entry */ 232 ep->dentry.stream.flags = ei->flags; 233 ep->dentry.stream.start_clu = 234 cpu_to_le32(ei->start_clu); 235 ep->dentry.stream.valid_size = 236 cpu_to_le64(i_size_read(inode)); 237 ep->dentry.stream.size = 238 ep->dentry.stream.valid_size; 239 240 exfat_update_dir_chksum_with_entry_set(es); 241 err = exfat_free_dentry_set(es, inode_needs_sync(inode)); 242 if (err) 243 return err; 244 } /* end of if != DIR_DELETED */ 245 246 inode->i_blocks += 247 num_to_be_allocated << sbi->sect_per_clus_bits; 248 249 /* 250 * Move *clu pointer along FAT chains (hole care) because the 251 * caller of this function expect *clu to be the last cluster. 252 * This only works when num_to_be_allocated >= 2, 253 * *clu = (the first cluster of the allocated chain) => 254 * (the last cluster of ...) 255 */ 256 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 257 *clu += num_to_be_allocated - 1; 258 } else { 259 while (num_to_be_allocated > 1) { 260 if (exfat_get_next_cluster(sb, clu)) 261 return -EIO; 262 num_to_be_allocated--; 263 } 264 } 265 266 } 267 268 /* hint information */ 269 ei->hint_bmap.off = local_clu_offset; 270 ei->hint_bmap.clu = *clu; 271 272 return 0; 273 } 274 275 static int exfat_map_new_buffer(struct exfat_inode_info *ei, 276 struct buffer_head *bh, loff_t pos) 277 { 278 if (buffer_delay(bh) && pos > ei->i_size_aligned) 279 return -EIO; 280 set_buffer_new(bh); 281 282 /* 283 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 284 */ 285 if (ei->i_size_ondisk > ei->i_size_aligned) 286 ei->i_size_aligned = ei->i_size_ondisk; 287 return 0; 288 } 289 290 static int exfat_get_block(struct inode *inode, sector_t iblock, 291 struct buffer_head *bh_result, int create) 292 { 293 struct exfat_inode_info *ei = EXFAT_I(inode); 294 struct super_block *sb = inode->i_sb; 295 struct exfat_sb_info *sbi = EXFAT_SB(sb); 296 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 297 int err = 0; 298 unsigned long mapped_blocks = 0; 299 unsigned int cluster, sec_offset; 300 sector_t last_block; 301 sector_t phys = 0; 302 loff_t pos; 303 304 mutex_lock(&sbi->s_lock); 305 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 306 if (iblock >= last_block && !create) 307 goto done; 308 309 /* Is this block already allocated? */ 310 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 311 &cluster, create); 312 if (err) { 313 if (err != -ENOSPC) 314 exfat_fs_error_ratelimit(sb, 315 "failed to bmap (inode : %p iblock : %llu, err : %d)", 316 inode, (unsigned long long)iblock, err); 317 goto unlock_ret; 318 } 319 320 if (cluster == EXFAT_EOF_CLUSTER) 321 goto done; 322 323 /* sector offset in cluster */ 324 sec_offset = iblock & (sbi->sect_per_clus - 1); 325 326 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 327 mapped_blocks = sbi->sect_per_clus - sec_offset; 328 max_blocks = min(mapped_blocks, max_blocks); 329 330 /* Treat newly added block / cluster */ 331 if (iblock < last_block) 332 create = 0; 333 334 if (create || buffer_delay(bh_result)) { 335 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 336 if (ei->i_size_ondisk < pos) 337 ei->i_size_ondisk = pos; 338 } 339 340 if (create) { 341 err = exfat_map_new_buffer(ei, bh_result, pos); 342 if (err) { 343 exfat_fs_error(sb, 344 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 345 pos, ei->i_size_aligned); 346 goto unlock_ret; 347 } 348 } 349 350 if (buffer_delay(bh_result)) 351 clear_buffer_delay(bh_result); 352 map_bh(bh_result, sb, phys); 353 done: 354 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 355 unlock_ret: 356 mutex_unlock(&sbi->s_lock); 357 return err; 358 } 359 360 static int exfat_readpage(struct file *file, struct page *page) 361 { 362 return mpage_readpage(page, exfat_get_block); 363 } 364 365 static void exfat_readahead(struct readahead_control *rac) 366 { 367 mpage_readahead(rac, exfat_get_block); 368 } 369 370 static int exfat_writepage(struct page *page, struct writeback_control *wbc) 371 { 372 return block_write_full_page(page, exfat_get_block, wbc); 373 } 374 375 static int exfat_writepages(struct address_space *mapping, 376 struct writeback_control *wbc) 377 { 378 return mpage_writepages(mapping, wbc, exfat_get_block); 379 } 380 381 static void exfat_write_failed(struct address_space *mapping, loff_t to) 382 { 383 struct inode *inode = mapping->host; 384 385 if (to > i_size_read(inode)) { 386 truncate_pagecache(inode, i_size_read(inode)); 387 exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned); 388 } 389 } 390 391 static int exfat_write_begin(struct file *file, struct address_space *mapping, 392 loff_t pos, unsigned int len, unsigned int flags, 393 struct page **pagep, void **fsdata) 394 { 395 int ret; 396 397 *pagep = NULL; 398 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 399 exfat_get_block, 400 &EXFAT_I(mapping->host)->i_size_ondisk); 401 402 if (ret < 0) 403 exfat_write_failed(mapping, pos+len); 404 405 return ret; 406 } 407 408 static int exfat_write_end(struct file *file, struct address_space *mapping, 409 loff_t pos, unsigned int len, unsigned int copied, 410 struct page *pagep, void *fsdata) 411 { 412 struct inode *inode = mapping->host; 413 struct exfat_inode_info *ei = EXFAT_I(inode); 414 int err; 415 416 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 417 418 if (EXFAT_I(inode)->i_size_aligned < i_size_read(inode)) { 419 exfat_fs_error(inode->i_sb, 420 "invalid size(size(%llu) > aligned(%llu)\n", 421 i_size_read(inode), EXFAT_I(inode)->i_size_aligned); 422 return -EIO; 423 } 424 425 if (err < len) 426 exfat_write_failed(mapping, pos+len); 427 428 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) { 429 inode->i_mtime = inode->i_ctime = current_time(inode); 430 ei->attr |= ATTR_ARCHIVE; 431 mark_inode_dirty(inode); 432 } 433 434 return err; 435 } 436 437 static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 438 { 439 struct address_space *mapping = iocb->ki_filp->f_mapping; 440 struct inode *inode = mapping->host; 441 loff_t size = iocb->ki_pos + iov_iter_count(iter); 442 int rw = iov_iter_rw(iter); 443 ssize_t ret; 444 445 if (rw == WRITE) { 446 /* 447 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 448 * so we need to update the ->i_size_aligned to block boundary. 449 * 450 * But we must fill the remaining area or hole by nul for 451 * updating ->i_size_aligned 452 * 453 * Return 0, and fallback to normal buffered write. 454 */ 455 if (EXFAT_I(inode)->i_size_aligned < size) 456 return 0; 457 } 458 459 /* 460 * Need to use the DIO_LOCKING for avoiding the race 461 * condition of exfat_get_block() and ->truncate(). 462 */ 463 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 464 if (ret < 0 && (rw & WRITE)) 465 exfat_write_failed(mapping, size); 466 return ret; 467 } 468 469 static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 470 { 471 sector_t blocknr; 472 473 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 474 down_read(&EXFAT_I(mapping->host)->truncate_lock); 475 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 476 up_read(&EXFAT_I(mapping->host)->truncate_lock); 477 return blocknr; 478 } 479 480 /* 481 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 482 * up to the end of the block which corresponds to `from'. 483 * This is required during truncate to physically zeroout the tail end 484 * of that block so it doesn't yield old data if the file is later grown. 485 * Also, avoid causing failure from fsx for cases of "data past EOF" 486 */ 487 int exfat_block_truncate_page(struct inode *inode, loff_t from) 488 { 489 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 490 } 491 492 static const struct address_space_operations exfat_aops = { 493 .readpage = exfat_readpage, 494 .readahead = exfat_readahead, 495 .writepage = exfat_writepage, 496 .writepages = exfat_writepages, 497 .write_begin = exfat_write_begin, 498 .write_end = exfat_write_end, 499 .direct_IO = exfat_direct_IO, 500 .bmap = exfat_aop_bmap 501 }; 502 503 static inline unsigned long exfat_hash(loff_t i_pos) 504 { 505 return hash_32(i_pos, EXFAT_HASH_BITS); 506 } 507 508 void exfat_hash_inode(struct inode *inode, loff_t i_pos) 509 { 510 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 511 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 512 513 spin_lock(&sbi->inode_hash_lock); 514 EXFAT_I(inode)->i_pos = i_pos; 515 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 516 spin_unlock(&sbi->inode_hash_lock); 517 } 518 519 void exfat_unhash_inode(struct inode *inode) 520 { 521 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 522 523 spin_lock(&sbi->inode_hash_lock); 524 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 525 EXFAT_I(inode)->i_pos = 0; 526 spin_unlock(&sbi->inode_hash_lock); 527 } 528 529 struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 530 { 531 struct exfat_sb_info *sbi = EXFAT_SB(sb); 532 struct exfat_inode_info *info; 533 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 534 struct inode *inode = NULL; 535 536 spin_lock(&sbi->inode_hash_lock); 537 hlist_for_each_entry(info, head, i_hash_fat) { 538 WARN_ON(info->vfs_inode.i_sb != sb); 539 540 if (i_pos != info->i_pos) 541 continue; 542 inode = igrab(&info->vfs_inode); 543 if (inode) 544 break; 545 } 546 spin_unlock(&sbi->inode_hash_lock); 547 return inode; 548 } 549 550 /* doesn't deal with root inode */ 551 static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 552 { 553 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 554 struct exfat_inode_info *ei = EXFAT_I(inode); 555 loff_t size = info->size; 556 557 ei->dir = info->dir; 558 ei->entry = info->entry; 559 ei->attr = info->attr; 560 ei->start_clu = info->start_clu; 561 ei->flags = info->flags; 562 ei->type = info->type; 563 564 ei->version = 0; 565 ei->hint_stat.eidx = 0; 566 ei->hint_stat.clu = info->start_clu; 567 ei->hint_femp.eidx = EXFAT_HINT_NONE; 568 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 569 ei->i_pos = 0; 570 571 inode->i_uid = sbi->options.fs_uid; 572 inode->i_gid = sbi->options.fs_gid; 573 inode_inc_iversion(inode); 574 inode->i_generation = prandom_u32(); 575 576 if (info->attr & ATTR_SUBDIR) { /* directory */ 577 inode->i_generation &= ~1; 578 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 579 inode->i_op = &exfat_dir_inode_operations; 580 inode->i_fop = &exfat_dir_operations; 581 set_nlink(inode, info->num_subdirs); 582 } else { /* regular file */ 583 inode->i_generation |= 1; 584 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 585 inode->i_op = &exfat_file_inode_operations; 586 inode->i_fop = &exfat_file_operations; 587 inode->i_mapping->a_ops = &exfat_aops; 588 inode->i_mapping->nrpages = 0; 589 } 590 591 i_size_write(inode, size); 592 593 /* ondisk and aligned size should be aligned with block size */ 594 if (size & (inode->i_sb->s_blocksize - 1)) { 595 size |= (inode->i_sb->s_blocksize - 1); 596 size++; 597 } 598 599 ei->i_size_aligned = size; 600 ei->i_size_ondisk = size; 601 602 exfat_save_attr(inode, info->attr); 603 604 inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) & 605 ~(sbi->cluster_size - 1)) >> inode->i_blkbits; 606 inode->i_mtime = info->mtime; 607 inode->i_ctime = info->mtime; 608 ei->i_crtime = info->crtime; 609 inode->i_atime = info->atime; 610 611 return 0; 612 } 613 614 struct inode *exfat_build_inode(struct super_block *sb, 615 struct exfat_dir_entry *info, loff_t i_pos) 616 { 617 struct inode *inode; 618 int err; 619 620 inode = exfat_iget(sb, i_pos); 621 if (inode) 622 goto out; 623 inode = new_inode(sb); 624 if (!inode) { 625 inode = ERR_PTR(-ENOMEM); 626 goto out; 627 } 628 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 629 inode_set_iversion(inode, 1); 630 err = exfat_fill_inode(inode, info); 631 if (err) { 632 iput(inode); 633 inode = ERR_PTR(err); 634 goto out; 635 } 636 exfat_hash_inode(inode, i_pos); 637 insert_inode_hash(inode); 638 out: 639 return inode; 640 } 641 642 void exfat_evict_inode(struct inode *inode) 643 { 644 truncate_inode_pages(&inode->i_data, 0); 645 646 if (!inode->i_nlink) { 647 i_size_write(inode, 0); 648 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 649 __exfat_truncate(inode, 0); 650 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 651 } 652 653 invalidate_inode_buffers(inode); 654 clear_inode(inode); 655 exfat_cache_inval_inode(inode); 656 exfat_unhash_inode(inode); 657 } 658