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 ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi); 118 119 if (EXFAT_I(inode)->i_size_ondisk > 0) 120 num_clusters = 121 EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, 122 sbi); 123 124 if (clu_offset >= num_clusters) 125 num_to_be_allocated = clu_offset - num_clusters + 1; 126 127 if (!create && (num_to_be_allocated > 0)) { 128 *clu = EXFAT_EOF_CLUSTER; 129 return 0; 130 } 131 132 *clu = last_clu = ei->start_clu; 133 134 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 135 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 136 last_clu += clu_offset - 1; 137 138 if (clu_offset == num_clusters) 139 *clu = EXFAT_EOF_CLUSTER; 140 else 141 *clu += clu_offset; 142 } 143 } else if (ei->type == TYPE_FILE) { 144 unsigned int fclus = 0; 145 int err = exfat_get_cluster(inode, clu_offset, 146 &fclus, clu, &last_clu, 1); 147 if (err) 148 return -EIO; 149 150 clu_offset -= fclus; 151 } else { 152 /* hint information */ 153 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 154 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 155 clu_offset -= ei->hint_bmap.off; 156 /* hint_bmap.clu should be valid */ 157 WARN_ON(ei->hint_bmap.clu < 2); 158 *clu = ei->hint_bmap.clu; 159 } 160 161 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 162 last_clu = *clu; 163 if (exfat_get_next_cluster(sb, clu)) 164 return -EIO; 165 clu_offset--; 166 } 167 } 168 169 if (*clu == EXFAT_EOF_CLUSTER) { 170 exfat_set_volume_dirty(sb); 171 172 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? 173 EXFAT_EOF_CLUSTER : last_clu + 1; 174 new_clu.size = 0; 175 new_clu.flags = ei->flags; 176 177 /* allocate a cluster */ 178 if (num_to_be_allocated < 1) { 179 /* Broken FAT (i_sze > allocated FAT) */ 180 exfat_fs_error(sb, "broken FAT chain."); 181 return -EIO; 182 } 183 184 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu); 185 if (ret) 186 return ret; 187 188 if (new_clu.dir == EXFAT_EOF_CLUSTER || 189 new_clu.dir == EXFAT_FREE_CLUSTER) { 190 exfat_fs_error(sb, 191 "bogus cluster new allocated (last_clu : %u, new_clu : %u)", 192 last_clu, new_clu.dir); 193 return -EIO; 194 } 195 196 /* append to the FAT chain */ 197 if (last_clu == EXFAT_EOF_CLUSTER) { 198 if (new_clu.flags == ALLOC_FAT_CHAIN) 199 ei->flags = ALLOC_FAT_CHAIN; 200 ei->start_clu = new_clu.dir; 201 modified = true; 202 } else { 203 if (new_clu.flags != ei->flags) { 204 /* no-fat-chain bit is disabled, 205 * so fat-chain should be synced with 206 * alloc-bitmap 207 */ 208 exfat_chain_cont_cluster(sb, ei->start_clu, 209 num_clusters); 210 ei->flags = ALLOC_FAT_CHAIN; 211 modified = true; 212 } 213 if (new_clu.flags == ALLOC_FAT_CHAIN) 214 if (exfat_ent_set(sb, last_clu, new_clu.dir)) 215 return -EIO; 216 } 217 218 num_clusters += num_to_be_allocated; 219 *clu = new_clu.dir; 220 221 if (ei->dir.dir != DIR_DELETED && modified) { 222 struct exfat_dentry *ep; 223 struct exfat_entry_set_cache *es; 224 int err; 225 226 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, 227 ES_ALL_ENTRIES); 228 if (!es) 229 return -EIO; 230 /* get stream entry */ 231 ep = exfat_get_dentry_cached(es, 1); 232 233 /* update directory entry */ 234 ep->dentry.stream.flags = ei->flags; 235 ep->dentry.stream.start_clu = 236 cpu_to_le32(ei->start_clu); 237 ep->dentry.stream.valid_size = 238 cpu_to_le64(i_size_read(inode)); 239 ep->dentry.stream.size = 240 ep->dentry.stream.valid_size; 241 242 exfat_update_dir_chksum_with_entry_set(es); 243 err = exfat_free_dentry_set(es, inode_needs_sync(inode)); 244 if (err) 245 return err; 246 } /* end of if != DIR_DELETED */ 247 248 inode->i_blocks += 249 num_to_be_allocated << sbi->sect_per_clus_bits; 250 251 /* 252 * Move *clu pointer along FAT chains (hole care) because the 253 * caller of this function expect *clu to be the last cluster. 254 * This only works when num_to_be_allocated >= 2, 255 * *clu = (the first cluster of the allocated chain) => 256 * (the last cluster of ...) 257 */ 258 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 259 *clu += num_to_be_allocated - 1; 260 } else { 261 while (num_to_be_allocated > 1) { 262 if (exfat_get_next_cluster(sb, clu)) 263 return -EIO; 264 num_to_be_allocated--; 265 } 266 } 267 268 } 269 270 /* hint information */ 271 ei->hint_bmap.off = local_clu_offset; 272 ei->hint_bmap.clu = *clu; 273 274 return 0; 275 } 276 277 static int exfat_map_new_buffer(struct exfat_inode_info *ei, 278 struct buffer_head *bh, loff_t pos) 279 { 280 if (buffer_delay(bh) && pos > ei->i_size_aligned) 281 return -EIO; 282 set_buffer_new(bh); 283 284 /* 285 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 286 */ 287 if (ei->i_size_ondisk > ei->i_size_aligned) 288 ei->i_size_aligned = ei->i_size_ondisk; 289 return 0; 290 } 291 292 static int exfat_get_block(struct inode *inode, sector_t iblock, 293 struct buffer_head *bh_result, int create) 294 { 295 struct exfat_inode_info *ei = EXFAT_I(inode); 296 struct super_block *sb = inode->i_sb; 297 struct exfat_sb_info *sbi = EXFAT_SB(sb); 298 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 299 int err = 0; 300 unsigned long mapped_blocks = 0; 301 unsigned int cluster, sec_offset; 302 sector_t last_block; 303 sector_t phys = 0; 304 loff_t pos; 305 306 mutex_lock(&sbi->s_lock); 307 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 308 if (iblock >= last_block && !create) 309 goto done; 310 311 /* Is this block already allocated? */ 312 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 313 &cluster, create); 314 if (err) { 315 if (err != -ENOSPC) 316 exfat_fs_error_ratelimit(sb, 317 "failed to bmap (inode : %p iblock : %llu, err : %d)", 318 inode, (unsigned long long)iblock, err); 319 goto unlock_ret; 320 } 321 322 if (cluster == EXFAT_EOF_CLUSTER) 323 goto done; 324 325 /* sector offset in cluster */ 326 sec_offset = iblock & (sbi->sect_per_clus - 1); 327 328 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 329 mapped_blocks = sbi->sect_per_clus - sec_offset; 330 max_blocks = min(mapped_blocks, max_blocks); 331 332 /* Treat newly added block / cluster */ 333 if (iblock < last_block) 334 create = 0; 335 336 if (create || buffer_delay(bh_result)) { 337 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 338 if (ei->i_size_ondisk < pos) 339 ei->i_size_ondisk = pos; 340 } 341 342 if (create) { 343 err = exfat_map_new_buffer(ei, bh_result, pos); 344 if (err) { 345 exfat_fs_error(sb, 346 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 347 pos, ei->i_size_aligned); 348 goto unlock_ret; 349 } 350 } 351 352 if (buffer_delay(bh_result)) 353 clear_buffer_delay(bh_result); 354 map_bh(bh_result, sb, phys); 355 done: 356 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 357 unlock_ret: 358 mutex_unlock(&sbi->s_lock); 359 return err; 360 } 361 362 static int exfat_readpage(struct file *file, struct page *page) 363 { 364 return mpage_readpage(page, exfat_get_block); 365 } 366 367 static void exfat_readahead(struct readahead_control *rac) 368 { 369 mpage_readahead(rac, exfat_get_block); 370 } 371 372 static int exfat_writepage(struct page *page, struct writeback_control *wbc) 373 { 374 return block_write_full_page(page, exfat_get_block, wbc); 375 } 376 377 static int exfat_writepages(struct address_space *mapping, 378 struct writeback_control *wbc) 379 { 380 return mpage_writepages(mapping, wbc, exfat_get_block); 381 } 382 383 static void exfat_write_failed(struct address_space *mapping, loff_t to) 384 { 385 struct inode *inode = mapping->host; 386 387 if (to > i_size_read(inode)) { 388 truncate_pagecache(inode, i_size_read(inode)); 389 exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned); 390 } 391 } 392 393 static int exfat_write_begin(struct file *file, struct address_space *mapping, 394 loff_t pos, unsigned int len, unsigned int flags, 395 struct page **pagep, void **fsdata) 396 { 397 int ret; 398 399 *pagep = NULL; 400 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 401 exfat_get_block, 402 &EXFAT_I(mapping->host)->i_size_ondisk); 403 404 if (ret < 0) 405 exfat_write_failed(mapping, pos+len); 406 407 return ret; 408 } 409 410 static int exfat_write_end(struct file *file, struct address_space *mapping, 411 loff_t pos, unsigned int len, unsigned int copied, 412 struct page *pagep, void *fsdata) 413 { 414 struct inode *inode = mapping->host; 415 struct exfat_inode_info *ei = EXFAT_I(inode); 416 int err; 417 418 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 419 420 if (EXFAT_I(inode)->i_size_aligned < i_size_read(inode)) { 421 exfat_fs_error(inode->i_sb, 422 "invalid size(size(%llu) > aligned(%llu)\n", 423 i_size_read(inode), EXFAT_I(inode)->i_size_aligned); 424 return -EIO; 425 } 426 427 if (err < len) 428 exfat_write_failed(mapping, pos+len); 429 430 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) { 431 inode->i_mtime = inode->i_ctime = current_time(inode); 432 ei->attr |= ATTR_ARCHIVE; 433 mark_inode_dirty(inode); 434 } 435 436 return err; 437 } 438 439 static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 440 { 441 struct address_space *mapping = iocb->ki_filp->f_mapping; 442 struct inode *inode = mapping->host; 443 loff_t size = iocb->ki_pos + iov_iter_count(iter); 444 int rw = iov_iter_rw(iter); 445 ssize_t ret; 446 447 if (rw == WRITE) { 448 /* 449 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 450 * so we need to update the ->i_size_aligned to block boundary. 451 * 452 * But we must fill the remaining area or hole by nul for 453 * updating ->i_size_aligned 454 * 455 * Return 0, and fallback to normal buffered write. 456 */ 457 if (EXFAT_I(inode)->i_size_aligned < size) 458 return 0; 459 } 460 461 /* 462 * Need to use the DIO_LOCKING for avoiding the race 463 * condition of exfat_get_block() and ->truncate(). 464 */ 465 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 466 if (ret < 0 && (rw & WRITE)) 467 exfat_write_failed(mapping, size); 468 return ret; 469 } 470 471 static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 472 { 473 sector_t blocknr; 474 475 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 476 down_read(&EXFAT_I(mapping->host)->truncate_lock); 477 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 478 up_read(&EXFAT_I(mapping->host)->truncate_lock); 479 return blocknr; 480 } 481 482 /* 483 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 484 * up to the end of the block which corresponds to `from'. 485 * This is required during truncate to physically zeroout the tail end 486 * of that block so it doesn't yield old data if the file is later grown. 487 * Also, avoid causing failure from fsx for cases of "data past EOF" 488 */ 489 int exfat_block_truncate_page(struct inode *inode, loff_t from) 490 { 491 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 492 } 493 494 static const struct address_space_operations exfat_aops = { 495 .readpage = exfat_readpage, 496 .readahead = exfat_readahead, 497 .writepage = exfat_writepage, 498 .writepages = exfat_writepages, 499 .write_begin = exfat_write_begin, 500 .write_end = exfat_write_end, 501 .direct_IO = exfat_direct_IO, 502 .bmap = exfat_aop_bmap 503 }; 504 505 static inline unsigned long exfat_hash(loff_t i_pos) 506 { 507 return hash_32(i_pos, EXFAT_HASH_BITS); 508 } 509 510 void exfat_hash_inode(struct inode *inode, loff_t i_pos) 511 { 512 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 513 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 514 515 spin_lock(&sbi->inode_hash_lock); 516 EXFAT_I(inode)->i_pos = i_pos; 517 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 518 spin_unlock(&sbi->inode_hash_lock); 519 } 520 521 void exfat_unhash_inode(struct inode *inode) 522 { 523 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 524 525 spin_lock(&sbi->inode_hash_lock); 526 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 527 EXFAT_I(inode)->i_pos = 0; 528 spin_unlock(&sbi->inode_hash_lock); 529 } 530 531 struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 532 { 533 struct exfat_sb_info *sbi = EXFAT_SB(sb); 534 struct exfat_inode_info *info; 535 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 536 struct inode *inode = NULL; 537 538 spin_lock(&sbi->inode_hash_lock); 539 hlist_for_each_entry(info, head, i_hash_fat) { 540 WARN_ON(info->vfs_inode.i_sb != sb); 541 542 if (i_pos != info->i_pos) 543 continue; 544 inode = igrab(&info->vfs_inode); 545 if (inode) 546 break; 547 } 548 spin_unlock(&sbi->inode_hash_lock); 549 return inode; 550 } 551 552 /* doesn't deal with root inode */ 553 static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 554 { 555 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 556 struct exfat_inode_info *ei = EXFAT_I(inode); 557 loff_t size = info->size; 558 559 memcpy(&ei->dir, &info->dir, sizeof(struct exfat_chain)); 560 ei->entry = info->entry; 561 ei->attr = info->attr; 562 ei->start_clu = info->start_clu; 563 ei->flags = info->flags; 564 ei->type = info->type; 565 566 ei->version = 0; 567 ei->hint_stat.eidx = 0; 568 ei->hint_stat.clu = info->start_clu; 569 ei->hint_femp.eidx = EXFAT_HINT_NONE; 570 ei->rwoffset = 0; 571 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 572 ei->i_pos = 0; 573 574 inode->i_uid = sbi->options.fs_uid; 575 inode->i_gid = sbi->options.fs_gid; 576 inode_inc_iversion(inode); 577 inode->i_generation = prandom_u32(); 578 579 if (info->attr & ATTR_SUBDIR) { /* directory */ 580 inode->i_generation &= ~1; 581 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 582 inode->i_op = &exfat_dir_inode_operations; 583 inode->i_fop = &exfat_dir_operations; 584 set_nlink(inode, info->num_subdirs); 585 } else { /* regular file */ 586 inode->i_generation |= 1; 587 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 588 inode->i_op = &exfat_file_inode_operations; 589 inode->i_fop = &exfat_file_operations; 590 inode->i_mapping->a_ops = &exfat_aops; 591 inode->i_mapping->nrpages = 0; 592 } 593 594 i_size_write(inode, size); 595 596 /* ondisk and aligned size should be aligned with block size */ 597 if (size & (inode->i_sb->s_blocksize - 1)) { 598 size |= (inode->i_sb->s_blocksize - 1); 599 size++; 600 } 601 602 ei->i_size_aligned = size; 603 ei->i_size_ondisk = size; 604 605 exfat_save_attr(inode, info->attr); 606 607 inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) & 608 ~(sbi->cluster_size - 1)) >> inode->i_blkbits; 609 inode->i_mtime = info->mtime; 610 inode->i_ctime = info->mtime; 611 ei->i_crtime = info->crtime; 612 inode->i_atime = info->atime; 613 614 exfat_cache_init_inode(inode); 615 616 return 0; 617 } 618 619 struct inode *exfat_build_inode(struct super_block *sb, 620 struct exfat_dir_entry *info, loff_t i_pos) 621 { 622 struct inode *inode; 623 int err; 624 625 inode = exfat_iget(sb, i_pos); 626 if (inode) 627 goto out; 628 inode = new_inode(sb); 629 if (!inode) { 630 inode = ERR_PTR(-ENOMEM); 631 goto out; 632 } 633 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 634 inode_set_iversion(inode, 1); 635 err = exfat_fill_inode(inode, info); 636 if (err) { 637 iput(inode); 638 inode = ERR_PTR(err); 639 goto out; 640 } 641 exfat_hash_inode(inode, i_pos); 642 insert_inode_hash(inode); 643 out: 644 return inode; 645 } 646 647 void exfat_evict_inode(struct inode *inode) 648 { 649 truncate_inode_pages(&inode->i_data, 0); 650 651 if (!inode->i_nlink) { 652 i_size_write(inode, 0); 653 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 654 __exfat_truncate(inode, 0); 655 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 656 } 657 658 invalidate_inode_buffers(inode); 659 clear_inode(inode); 660 exfat_cache_inval_inode(inode); 661 exfat_unhash_inode(inode); 662 } 663