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 20static 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 83int 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 94void 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 */ 105static 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 (ei->i_size_ondisk > 0) 118 num_clusters = 119 EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi); 120 121 if (clu_offset >= num_clusters) 122 num_to_be_allocated = clu_offset - num_clusters + 1; 123 124 if (!create && (num_to_be_allocated > 0)) { 125 *clu = EXFAT_EOF_CLUSTER; 126 return 0; 127 } 128 129 *clu = last_clu = ei->start_clu; 130 131 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 132 if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 133 last_clu += clu_offset - 1; 134 135 if (clu_offset == num_clusters) 136 *clu = EXFAT_EOF_CLUSTER; 137 else 138 *clu += clu_offset; 139 } 140 } else if (ei->type == TYPE_FILE) { 141 unsigned int fclus = 0; 142 int err = exfat_get_cluster(inode, clu_offset, 143 &fclus, clu, &last_clu, 1); 144 if (err) 145 return -EIO; 146 147 clu_offset -= fclus; 148 } else { 149 /* hint information */ 150 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 151 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 152 clu_offset -= ei->hint_bmap.off; 153 /* hint_bmap.clu should be valid */ 154 WARN_ON(ei->hint_bmap.clu < 2); 155 *clu = ei->hint_bmap.clu; 156 } 157 158 while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { 159 last_clu = *clu; 160 if (exfat_get_next_cluster(sb, clu)) 161 return -EIO; 162 clu_offset--; 163 } 164 } 165 166 if (*clu == EXFAT_EOF_CLUSTER) { 167 exfat_set_volume_dirty(sb); 168 169 new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? 170 EXFAT_EOF_CLUSTER : last_clu + 1; 171 new_clu.size = 0; 172 new_clu.flags = ei->flags; 173 174 /* allocate a cluster */ 175 if (num_to_be_allocated < 1) { 176 /* Broken FAT (i_sze > allocated FAT) */ 177 exfat_fs_error(sb, "broken FAT chain."); 178 return -EIO; 179 } 180 181 ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu); 182 if (ret) 183 return ret; 184 185 if (new_clu.dir == EXFAT_EOF_CLUSTER || 186 new_clu.dir == EXFAT_FREE_CLUSTER) { 187 exfat_fs_error(sb, 188 "bogus cluster new allocated (last_clu : %u, new_clu : %u)", 189 last_clu, new_clu.dir); 190 return -EIO; 191 } 192 193 /* append to the FAT chain */ 194 if (last_clu == EXFAT_EOF_CLUSTER) { 195 if (new_clu.flags == ALLOC_FAT_CHAIN) 196 ei->flags = ALLOC_FAT_CHAIN; 197 ei->start_clu = new_clu.dir; 198 modified = true; 199 } else { 200 if (new_clu.flags != ei->flags) { 201 /* no-fat-chain bit is disabled, 202 * so fat-chain should be synced with 203 * alloc-bitmap 204 */ 205 exfat_chain_cont_cluster(sb, ei->start_clu, 206 num_clusters); 207 ei->flags = ALLOC_FAT_CHAIN; 208 modified = true; 209 } 210 if (new_clu.flags == ALLOC_FAT_CHAIN) 211 if (exfat_ent_set(sb, last_clu, new_clu.dir)) 212 return -EIO; 213 } 214 215 num_clusters += num_to_be_allocated; 216 *clu = new_clu.dir; 217 218 if (ei->dir.dir != DIR_DELETED && modified) { 219 struct exfat_dentry *ep; 220 struct exfat_entry_set_cache *es; 221 int err; 222 223 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, 224 ES_ALL_ENTRIES); 225 if (!es) 226 return -EIO; 227 /* get stream entry */ 228 ep = exfat_get_dentry_cached(es, 1); 229 230 /* update directory entry */ 231 ep->dentry.stream.flags = ei->flags; 232 ep->dentry.stream.start_clu = 233 cpu_to_le32(ei->start_clu); 234 ep->dentry.stream.valid_size = 235 cpu_to_le64(i_size_read(inode)); 236 ep->dentry.stream.size = 237 ep->dentry.stream.valid_size; 238 239 exfat_update_dir_chksum_with_entry_set(es); 240 err = exfat_free_dentry_set(es, inode_needs_sync(inode)); 241 if (err) 242 return err; 243 } /* end of if != DIR_DELETED */ 244 245 inode->i_blocks += EXFAT_CLU_TO_B(num_to_be_allocated, sbi) >> 9; 246 247 /* 248 * Move *clu pointer along FAT chains (hole care) because the 249 * caller of this function expect *clu to be the last cluster. 250 * This only works when num_to_be_allocated >= 2, 251 * *clu = (the first cluster of the allocated chain) => 252 * (the last cluster of ...) 253 */ 254 if (ei->flags == ALLOC_NO_FAT_CHAIN) { 255 *clu += num_to_be_allocated - 1; 256 } else { 257 while (num_to_be_allocated > 1) { 258 if (exfat_get_next_cluster(sb, clu)) 259 return -EIO; 260 num_to_be_allocated--; 261 } 262 } 263 264 } 265 266 /* hint information */ 267 ei->hint_bmap.off = local_clu_offset; 268 ei->hint_bmap.clu = *clu; 269 270 return 0; 271} 272 273static int exfat_map_new_buffer(struct exfat_inode_info *ei, 274 struct buffer_head *bh, loff_t pos) 275{ 276 if (buffer_delay(bh) && pos > ei->i_size_aligned) 277 return -EIO; 278 set_buffer_new(bh); 279 280 /* 281 * Adjust i_size_aligned if i_size_ondisk is bigger than it. 282 */ 283 if (ei->i_size_ondisk > ei->i_size_aligned) 284 ei->i_size_aligned = ei->i_size_ondisk; 285 return 0; 286} 287 288static int exfat_get_block(struct inode *inode, sector_t iblock, 289 struct buffer_head *bh_result, int create) 290{ 291 struct exfat_inode_info *ei = EXFAT_I(inode); 292 struct super_block *sb = inode->i_sb; 293 struct exfat_sb_info *sbi = EXFAT_SB(sb); 294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 295 int err = 0; 296 unsigned long mapped_blocks = 0; 297 unsigned int cluster, sec_offset; 298 sector_t last_block; 299 sector_t phys = 0; 300 loff_t pos; 301 302 mutex_lock(&sbi->s_lock); 303 last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb); 304 if (iblock >= last_block && !create) 305 goto done; 306 307 /* Is this block already allocated? */ 308 err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits, 309 &cluster, create); 310 if (err) { 311 if (err != -ENOSPC) 312 exfat_fs_error_ratelimit(sb, 313 "failed to bmap (inode : %p iblock : %llu, err : %d)", 314 inode, (unsigned long long)iblock, err); 315 goto unlock_ret; 316 } 317 318 if (cluster == EXFAT_EOF_CLUSTER) 319 goto done; 320 321 /* sector offset in cluster */ 322 sec_offset = iblock & (sbi->sect_per_clus - 1); 323 324 phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset; 325 mapped_blocks = sbi->sect_per_clus - sec_offset; 326 max_blocks = min(mapped_blocks, max_blocks); 327 328 /* Treat newly added block / cluster */ 329 if (iblock < last_block) 330 create = 0; 331 332 if (create || buffer_delay(bh_result)) { 333 pos = EXFAT_BLK_TO_B((iblock + 1), sb); 334 if (ei->i_size_ondisk < pos) 335 ei->i_size_ondisk = pos; 336 } 337 338 if (create) { 339 err = exfat_map_new_buffer(ei, bh_result, pos); 340 if (err) { 341 exfat_fs_error(sb, 342 "requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n", 343 pos, ei->i_size_aligned); 344 goto unlock_ret; 345 } 346 } 347 348 if (buffer_delay(bh_result)) 349 clear_buffer_delay(bh_result); 350 map_bh(bh_result, sb, phys); 351done: 352 bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb); 353unlock_ret: 354 mutex_unlock(&sbi->s_lock); 355 return err; 356} 357 358static int exfat_readpage(struct file *file, struct page *page) 359{ 360 return mpage_readpage(page, exfat_get_block); 361} 362 363static void exfat_readahead(struct readahead_control *rac) 364{ 365 mpage_readahead(rac, exfat_get_block); 366} 367 368static int exfat_writepage(struct page *page, struct writeback_control *wbc) 369{ 370 return block_write_full_page(page, exfat_get_block, wbc); 371} 372 373static int exfat_writepages(struct address_space *mapping, 374 struct writeback_control *wbc) 375{ 376 return mpage_writepages(mapping, wbc, exfat_get_block); 377} 378 379static void exfat_write_failed(struct address_space *mapping, loff_t to) 380{ 381 struct inode *inode = mapping->host; 382 383 if (to > i_size_read(inode)) { 384 truncate_pagecache(inode, i_size_read(inode)); 385 exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned); 386 } 387} 388 389static int exfat_write_begin(struct file *file, struct address_space *mapping, 390 loff_t pos, unsigned int len, unsigned int flags, 391 struct page **pagep, void **fsdata) 392{ 393 int ret; 394 395 *pagep = NULL; 396 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 397 exfat_get_block, 398 &EXFAT_I(mapping->host)->i_size_ondisk); 399 400 if (ret < 0) 401 exfat_write_failed(mapping, pos+len); 402 403 return ret; 404} 405 406static int exfat_write_end(struct file *file, struct address_space *mapping, 407 loff_t pos, unsigned int len, unsigned int copied, 408 struct page *pagep, void *fsdata) 409{ 410 struct inode *inode = mapping->host; 411 struct exfat_inode_info *ei = EXFAT_I(inode); 412 int err; 413 414 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 415 416 if (ei->i_size_aligned < i_size_read(inode)) { 417 exfat_fs_error(inode->i_sb, 418 "invalid size(size(%llu) > aligned(%llu)\n", 419 i_size_read(inode), ei->i_size_aligned); 420 return -EIO; 421 } 422 423 if (err < len) 424 exfat_write_failed(mapping, pos+len); 425 426 if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) { 427 inode->i_mtime = inode->i_ctime = current_time(inode); 428 ei->attr |= ATTR_ARCHIVE; 429 mark_inode_dirty(inode); 430 } 431 432 return err; 433} 434 435static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 436{ 437 struct address_space *mapping = iocb->ki_filp->f_mapping; 438 struct inode *inode = mapping->host; 439 loff_t size = iocb->ki_pos + iov_iter_count(iter); 440 int rw = iov_iter_rw(iter); 441 ssize_t ret; 442 443 if (rw == WRITE) { 444 /* 445 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 446 * so we need to update the ->i_size_aligned to block boundary. 447 * 448 * But we must fill the remaining area or hole by nul for 449 * updating ->i_size_aligned 450 * 451 * Return 0, and fallback to normal buffered write. 452 */ 453 if (EXFAT_I(inode)->i_size_aligned < size) 454 return 0; 455 } 456 457 /* 458 * Need to use the DIO_LOCKING for avoiding the race 459 * condition of exfat_get_block() and ->truncate(). 460 */ 461 ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block); 462 if (ret < 0 && (rw & WRITE)) 463 exfat_write_failed(mapping, size); 464 return ret; 465} 466 467static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) 468{ 469 sector_t blocknr; 470 471 /* exfat_get_cluster() assumes the requested blocknr isn't truncated. */ 472 down_read(&EXFAT_I(mapping->host)->truncate_lock); 473 blocknr = generic_block_bmap(mapping, block, exfat_get_block); 474 up_read(&EXFAT_I(mapping->host)->truncate_lock); 475 return blocknr; 476} 477 478/* 479 * exfat_block_truncate_page() zeroes out a mapping from file offset `from' 480 * up to the end of the block which corresponds to `from'. 481 * This is required during truncate to physically zeroout the tail end 482 * of that block so it doesn't yield old data if the file is later grown. 483 * Also, avoid causing failure from fsx for cases of "data past EOF" 484 */ 485int exfat_block_truncate_page(struct inode *inode, loff_t from) 486{ 487 return block_truncate_page(inode->i_mapping, from, exfat_get_block); 488} 489 490static const struct address_space_operations exfat_aops = { 491 .readpage = exfat_readpage, 492 .readahead = exfat_readahead, 493 .writepage = exfat_writepage, 494 .writepages = exfat_writepages, 495 .write_begin = exfat_write_begin, 496 .write_end = exfat_write_end, 497 .direct_IO = exfat_direct_IO, 498 .bmap = exfat_aop_bmap 499}; 500 501static inline unsigned long exfat_hash(loff_t i_pos) 502{ 503 return hash_32(i_pos, EXFAT_HASH_BITS); 504} 505 506void exfat_hash_inode(struct inode *inode, loff_t i_pos) 507{ 508 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 509 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 510 511 spin_lock(&sbi->inode_hash_lock); 512 EXFAT_I(inode)->i_pos = i_pos; 513 hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); 514 spin_unlock(&sbi->inode_hash_lock); 515} 516 517void exfat_unhash_inode(struct inode *inode) 518{ 519 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 520 521 spin_lock(&sbi->inode_hash_lock); 522 hlist_del_init(&EXFAT_I(inode)->i_hash_fat); 523 EXFAT_I(inode)->i_pos = 0; 524 spin_unlock(&sbi->inode_hash_lock); 525} 526 527struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) 528{ 529 struct exfat_sb_info *sbi = EXFAT_SB(sb); 530 struct exfat_inode_info *info; 531 struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); 532 struct inode *inode = NULL; 533 534 spin_lock(&sbi->inode_hash_lock); 535 hlist_for_each_entry(info, head, i_hash_fat) { 536 WARN_ON(info->vfs_inode.i_sb != sb); 537 538 if (i_pos != info->i_pos) 539 continue; 540 inode = igrab(&info->vfs_inode); 541 if (inode) 542 break; 543 } 544 spin_unlock(&sbi->inode_hash_lock); 545 return inode; 546} 547 548/* doesn't deal with root inode */ 549static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) 550{ 551 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 552 struct exfat_inode_info *ei = EXFAT_I(inode); 553 loff_t size = info->size; 554 555 ei->dir = info->dir; 556 ei->entry = info->entry; 557 ei->attr = info->attr; 558 ei->start_clu = info->start_clu; 559 ei->flags = info->flags; 560 ei->type = info->type; 561 562 ei->version = 0; 563 ei->hint_stat.eidx = 0; 564 ei->hint_stat.clu = info->start_clu; 565 ei->hint_femp.eidx = EXFAT_HINT_NONE; 566 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 567 ei->i_pos = 0; 568 569 inode->i_uid = sbi->options.fs_uid; 570 inode->i_gid = sbi->options.fs_gid; 571 inode_inc_iversion(inode); 572 inode->i_generation = prandom_u32(); 573 574 if (info->attr & ATTR_SUBDIR) { /* directory */ 575 inode->i_generation &= ~1; 576 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 577 inode->i_op = &exfat_dir_inode_operations; 578 inode->i_fop = &exfat_dir_operations; 579 set_nlink(inode, info->num_subdirs); 580 } else { /* regular file */ 581 inode->i_generation |= 1; 582 inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); 583 inode->i_op = &exfat_file_inode_operations; 584 inode->i_fop = &exfat_file_operations; 585 inode->i_mapping->a_ops = &exfat_aops; 586 inode->i_mapping->nrpages = 0; 587 } 588 589 i_size_write(inode, size); 590 591 /* ondisk and aligned size should be aligned with block size */ 592 if (size & (inode->i_sb->s_blocksize - 1)) { 593 size |= (inode->i_sb->s_blocksize - 1); 594 size++; 595 } 596 597 ei->i_size_aligned = size; 598 ei->i_size_ondisk = size; 599 600 exfat_save_attr(inode, info->attr); 601 602 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 603 inode->i_mtime = info->mtime; 604 inode->i_ctime = info->mtime; 605 ei->i_crtime = info->crtime; 606 inode->i_atime = info->atime; 607 608 return 0; 609} 610 611struct inode *exfat_build_inode(struct super_block *sb, 612 struct exfat_dir_entry *info, loff_t i_pos) 613{ 614 struct inode *inode; 615 int err; 616 617 inode = exfat_iget(sb, i_pos); 618 if (inode) 619 goto out; 620 inode = new_inode(sb); 621 if (!inode) { 622 inode = ERR_PTR(-ENOMEM); 623 goto out; 624 } 625 inode->i_ino = iunique(sb, EXFAT_ROOT_INO); 626 inode_set_iversion(inode, 1); 627 err = exfat_fill_inode(inode, info); 628 if (err) { 629 iput(inode); 630 inode = ERR_PTR(err); 631 goto out; 632 } 633 exfat_hash_inode(inode, i_pos); 634 insert_inode_hash(inode); 635out: 636 return inode; 637} 638 639void exfat_evict_inode(struct inode *inode) 640{ 641 truncate_inode_pages(&inode->i_data, 0); 642 643 if (!inode->i_nlink) { 644 i_size_write(inode, 0); 645 mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); 646 __exfat_truncate(inode, 0); 647 mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); 648 } 649 650 invalidate_inode_buffers(inode); 651 clear_inode(inode); 652 exfat_cache_inval_inode(inode); 653 exfat_unhash_inode(inode); 654} 655