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 20int __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 89int 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 100void 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 */ 111static 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 += EXFAT_CLU_TO_B(num_to_be_allocated, sbi) >> 9; 224 225 /* 226 * Move *clu pointer along FAT chains (hole care) because the 227 * caller of this function expect *clu to be the last cluster. 228 * This only works when num_to_be_allocated >= 2, 229 * *clu = (the first cluster of the allocated chain) => 230 * (the last cluster of ...) 231 */ 232 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 233 *clu += num_to_be_allocated - 1; 234 } else { 235 while (num_to_be_allocated > 1) { 236 if (exfat_get_next_cluster(sb, clu)) 237 return -EIO; 238 num_to_be_allocated--; 239 } 240 } 241 242 } 243 244 /* hint information */ 245 ei->hint_bmap.off = local_clu_offset; 246 ei->hint_bmap.clu = *clu; 247 248 return 0; 249} 250 251static int exfat_map_new_buffer(struct exfat_inode_info *ei, 252 struct buffer_head *bh, loff_t pos) 253{ 254 if (buffer_delay(bh) && pos > ei->i_size_aligned) 255 return -EIO; 256 set_buffer_new(bh); 257 258 /* 259 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 260 */ 261 if (ei->i_size_ondisk > ei->i_size_aligned) 262 ei->i_size_aligned = ei->i_size_ondisk; 263 return 0; 264} 265 266static int exfat_get_block(struct inode *inode, sector_t iblock, 267 struct buffer_head *bh_result, int create) 268{ 269 struct exfat_inode_info *ei = EXFAT_I(inode); 270 struct super_block *sb = inode->i_sb; 271 struct exfat_sb_info *sbi = EXFAT_SB(sb); 272 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 273 int err = 0; 274 unsigned long mapped_blocks = 0; 275 unsigned int cluster, sec_offset; 276 sector_t last_block; 277 sector_t phys = 0; 278 loff_t pos; 279 280 mutex_lock(&sbi->s_lock); 281 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 282 if (iblock >= last_block && !create) 283 goto done; 284 285 /* Is this block already allocated? */ 286 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 287 &cluster, create); 288 if (err) { 289 if (err != -ENOSPC) 290 exfat_fs_error_ratelimit(sb, 291 "failed to bmap (inode : %p iblock : %llu, err : %d)", 292 inode, (unsigned long long)iblock, err); 293 goto unlock_ret; 294 } 295 296 if (cluster == EXFAT_EOF_CLUSTER) 297 goto done; 298 299 /* sector offset in cluster */ 300 sec_offset = iblock & (sbi->sect_per_clus - 1); 301 302 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 303 mapped_blocks = sbi->sect_per_clus - sec_offset; 304 max_blocks = min(mapped_blocks, max_blocks); 305 306 /* Treat newly added block / cluster */ 307 if (iblock < last_block) 308 create = 0; 309 310 if (create || buffer_delay(bh_result)) { 311 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 312 if (ei->i_size_ondisk < pos) 313 ei->i_size_ondisk = pos; 314 } 315 316 if (create) { 317 err = exfat_map_new_buffer(ei, bh_result, pos); 318 if (err) { 319 exfat_fs_error(sb, 320 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 321 pos, ei->i_size_aligned); 322 goto unlock_ret; 323 } 324 } 325 326 if (buffer_delay(bh_result)) 327 clear_buffer_delay(bh_result); 328 map_bh(bh_result, sb, phys); 329done: 330 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 331unlock_ret: 332 mutex_unlock(&sbi->s_lock); 333 return err; 334} 335 336static int exfat_read_folio(struct file *file, struct folio *folio) 337{ 338 return mpage_read_folio(folio, exfat_get_block); 339} 340 341static void exfat_readahead(struct readahead_control *rac) 342{ 343 mpage_readahead(rac, exfat_get_block); 344} 345 346static int exfat_writepages(struct address_space *mapping, 347 struct writeback_control *wbc) 348{ 349 return mpage_writepages(mapping, wbc, exfat_get_block); 350} 351 352static void exfat_write_failed(struct address_space *mapping, loff_t to) 353{ 354 struct inode *inode = mapping->host; 355 356 if (to > i_size_read(inode)) { 357 truncate_pagecache(inode, i_size_read(inode)); 358 inode->i_mtime = inode_set_ctime_current(inode); 359 exfat_truncate(inode); 360 } 361} 362 363static int exfat_write_begin(struct file *file, struct address_space *mapping, 364 loff_t pos, unsigned int len, 365 struct page **pagep, void **fsdata) 366{ 367 int ret; 368 369 *pagep = NULL; 370 ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, 371 exfat_get_block, 372 &EXFAT_I(mapping->host)->i_size_ondisk); 373 374 if (ret < 0) 375 exfat_write_failed(mapping, pos+len); 376 377 return ret; 378} 379 380static int exfat_write_end(struct file *file, struct address_space *mapping, 381 loff_t pos, unsigned int len, unsigned int copied, 382 struct page *pagep, void *fsdata) 383{ 384 struct inode *inode = mapping->host; 385 struct exfat_inode_info *ei = EXFAT_I(inode); 386 int err; 387 388 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 389 390 if (ei->i_size_aligned < i_size_read(inode)) { 391 exfat_fs_error(inode->i_sb, 392 "invalid size(size(%llu) > aligned(%llu)\n", 393 i_size_read(inode), ei->i_size_aligned); 394 return -EIO; 395 } 396 397 if (err < len) 398 exfat_write_failed(mapping, pos+len); 399 400 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) { 401 inode->i_mtime = inode_set_ctime_current(inode); 402 ei->attr |= ATTR_ARCHIVE; 403 mark_inode_dirty(inode); 404 } 405 406 return err; 407} 408 409static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 410{ 411 struct address_space *mapping = iocb->ki_filp->f_mapping; 412 struct inode *inode = mapping->host; 413 loff_t size = iocb->ki_pos + iov_iter_count(iter); 414 int rw = iov_iter_rw(iter); 415 ssize_t ret; 416 417 if (rw == WRITE) { 418 /* 419 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 420 * so we need to update the ->i_size_aligned to block boundary. 421 * 422 * But we must fill the remaining area or hole by nul for 423 * updating ->i_size_aligned 424 * 425 * Return 0, and fallback to normal buffered write. 426 */ 427 if (EXFAT_I(inode)->i_size_aligned < size) 428 return 0; 429 } 430 431 /* 432 * Need to use the DIO_LOCKING for avoiding the race 433 * condition of exfat_get_block() and ->truncate(). 434 */ 435 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 436 if (ret < 0 && (rw & WRITE)) 437 exfat_write_failed(mapping, size); 438 return ret; 439} 440 441static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 442{ 443 sector_t blocknr; 444 445 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 446 down_read(&EXFAT_I(mapping->host)->truncate_lock); 447 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 448 up_read(&EXFAT_I(mapping->host)->truncate_lock); 449 return blocknr; 450} 451 452/* 453 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 454 * up to the end of the block which corresponds to `from'. 455 * This is required during truncate to physically zeroout the tail end 456 * of that block so it doesn't yield old data if the file is later grown. 457 * Also, avoid causing failure from fsx for cases of "data past EOF" 458 */ 459int exfat_block_truncate_page(struct inode *inode, loff_t from) 460{ 461 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 462} 463 464static const struct address_space_operations exfat_aops = { 465 .dirty_folio = block_dirty_folio, 466 .invalidate_folio = block_invalidate_folio, 467 .read_folio = exfat_read_folio, 468 .readahead = exfat_readahead, 469 .writepages = exfat_writepages, 470 .write_begin = exfat_write_begin, 471 .write_end = exfat_write_end, 472 .direct_IO = exfat_direct_IO, 473 .bmap = exfat_aop_bmap, 474 .migrate_folio = buffer_migrate_folio, 475}; 476 477static inline unsigned long exfat_hash(loff_t i_pos) 478{ 479 return hash_32(i_pos, EXFAT_HASH_BITS); 480} 481 482void exfat_hash_inode(struct inode *inode, loff_t i_pos) 483{ 484 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 485 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 486 487 spin_lock(&sbi->inode_hash_lock); 488 EXFAT_I(inode)->i_pos = i_pos; 489 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 490 spin_unlock(&sbi->inode_hash_lock); 491} 492 493void exfat_unhash_inode(struct inode *inode) 494{ 495 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 496 497 spin_lock(&sbi->inode_hash_lock); 498 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 499 EXFAT_I(inode)->i_pos = 0; 500 spin_unlock(&sbi->inode_hash_lock); 501} 502 503struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 504{ 505 struct exfat_sb_info *sbi = EXFAT_SB(sb); 506 struct exfat_inode_info *info; 507 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 508 struct inode *inode = NULL; 509 510 spin_lock(&sbi->inode_hash_lock); 511 hlist_for_each_entry(info, head, i_hash_fat) { 512 WARN_ON(info->vfs_inode.i_sb != sb); 513 514 if (i_pos != info->i_pos) 515 continue; 516 inode = igrab(&info->vfs_inode); 517 if (inode) 518 break; 519 } 520 spin_unlock(&sbi->inode_hash_lock); 521 return inode; 522} 523 524/* doesn't deal with root inode */ 525static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 526{ 527 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 528 struct exfat_inode_info *ei = EXFAT_I(inode); 529 loff_t size = info->size; 530 531 ei->dir = info->dir; 532 ei->entry = info->entry; 533 ei->attr = info->attr; 534 ei->start_clu = info->start_clu; 535 ei->flags = info->flags; 536 ei->type = info->type; 537 538 ei->version = 0; 539 ei->hint_stat.eidx = 0; 540 ei->hint_stat.clu = info->start_clu; 541 ei->hint_femp.eidx = EXFAT_HINT_NONE; 542 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 543 ei->i_pos = 0; 544 545 inode->i_uid = sbi->options.fs_uid; 546 inode->i_gid = sbi->options.fs_gid; 547 inode_inc_iversion(inode); 548 inode->i_generation = get_random_u32(); 549 550 if (info->attr & ATTR_SUBDIR) { /* directory */ 551 inode->i_generation &= ~1; 552 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 553 inode->i_op = &exfat_dir_inode_operations; 554 inode->i_fop = &exfat_dir_operations; 555 set_nlink(inode, info->num_subdirs); 556 } else { /* regular file */ 557 inode->i_generation |= 1; 558 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 559 inode->i_op = &exfat_file_inode_operations; 560 inode->i_fop = &exfat_file_operations; 561 inode->i_mapping->a_ops = &exfat_aops; 562 inode->i_mapping->nrpages = 0; 563 } 564 565 i_size_write(inode, size); 566 567 /* ondisk and aligned size should be aligned with block size */ 568 if (size & (inode->i_sb->s_blocksize - 1)) { 569 size |= (inode->i_sb->s_blocksize - 1); 570 size++; 571 } 572 573 ei->i_size_aligned = size; 574 ei->i_size_ondisk = size; 575 576 exfat_save_attr(inode, info->attr); 577 578 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 579 inode->i_mtime = info->mtime; 580 inode_set_ctime_to_ts(inode, info->mtime); 581 ei->i_crtime = info->crtime; 582 inode->i_atime = info->atime; 583 584 return 0; 585} 586 587struct inode *exfat_build_inode(struct super_block *sb, 588 struct exfat_dir_entry *info, loff_t i_pos) 589{ 590 struct inode *inode; 591 int err; 592 593 inode = exfat_iget(sb, i_pos); 594 if (inode) 595 goto out; 596 inode = new_inode(sb); 597 if (!inode) { 598 inode = ERR_PTR(-ENOMEM); 599 goto out; 600 } 601 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 602 inode_set_iversion(inode, 1); 603 err = exfat_fill_inode(inode, info); 604 if (err) { 605 iput(inode); 606 inode = ERR_PTR(err); 607 goto out; 608 } 609 exfat_hash_inode(inode, i_pos); 610 insert_inode_hash(inode); 611out: 612 return inode; 613} 614 615void exfat_evict_inode(struct inode *inode) 616{ 617 truncate_inode_pages(&inode->i_data, 0); 618 619 if (!inode->i_nlink) { 620 i_size_write(inode, 0); 621 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 622 __exfat_truncate(inode); 623 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 624 } 625 626 invalidate_inode_buffers(inode); 627 clear_inode(inode); 628 exfat_cache_inval_inode(inode); 629 exfat_unhash_inode(inode); 630} 631