1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/fat/inode.c 4 * 5 * Written 1992,1993 by Werner Almesberger 6 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner 7 * Rewritten for the constant inumbers support by Al Viro 8 * 9 * Fixes: 10 * 11 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0 12 */ 13 14 #include <linux/module.h> 15 #include <linux/pagemap.h> 16 #include <linux/mpage.h> 17 #include <linux/vfs.h> 18 #include <linux/seq_file.h> 19 #include <linux/uio.h> 20 #include <linux/blkdev.h> 21 #include <linux/backing-dev.h> 22 #include <linux/unaligned.h> 23 #include <linux/random.h> 24 #include <linux/iversion.h> 25 #include "fat.h" 26 27 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 28 /* if user don't select VFAT, this is undefined. */ 29 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 30 #endif 31 32 #define KB_IN_SECTORS 2 33 34 /* DOS dates from 1980/1/1 through 2107/12/31 */ 35 #define FAT_DATE_MIN (0<<9 | 1<<5 | 1) 36 #define FAT_DATE_MAX (127<<9 | 12<<5 | 31) 37 #define FAT_TIME_MAX (23<<11 | 59<<5 | 29) 38 39 /* 40 * A deserialized copy of the on-disk structure laid out in struct 41 * fat_boot_sector. 42 */ 43 struct fat_bios_param_block { 44 u16 fat_sector_size; 45 u8 fat_sec_per_clus; 46 u16 fat_reserved; 47 u8 fat_fats; 48 u16 fat_dir_entries; 49 u16 fat_sectors; 50 u16 fat_fat_length; 51 u32 fat_total_sect; 52 53 u8 fat16_state; 54 u32 fat16_vol_id; 55 56 u32 fat32_length; 57 u32 fat32_root_cluster; 58 u16 fat32_info_sector; 59 u8 fat32_state; 60 u32 fat32_vol_id; 61 }; 62 63 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 64 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 65 66 static struct fat_floppy_defaults { 67 unsigned nr_sectors; 68 unsigned sec_per_clus; 69 unsigned dir_entries; 70 unsigned media; 71 unsigned fat_length; 72 } floppy_defaults[] = { 73 { 74 .nr_sectors = 160 * KB_IN_SECTORS, 75 .sec_per_clus = 1, 76 .dir_entries = 64, 77 .media = 0xFE, 78 .fat_length = 1, 79 }, 80 { 81 .nr_sectors = 180 * KB_IN_SECTORS, 82 .sec_per_clus = 1, 83 .dir_entries = 64, 84 .media = 0xFC, 85 .fat_length = 2, 86 }, 87 { 88 .nr_sectors = 320 * KB_IN_SECTORS, 89 .sec_per_clus = 2, 90 .dir_entries = 112, 91 .media = 0xFF, 92 .fat_length = 1, 93 }, 94 { 95 .nr_sectors = 360 * KB_IN_SECTORS, 96 .sec_per_clus = 2, 97 .dir_entries = 112, 98 .media = 0xFD, 99 .fat_length = 2, 100 }, 101 }; 102 103 int fat_add_cluster(struct inode *inode) 104 { 105 int err, cluster; 106 107 err = fat_alloc_clusters(inode, &cluster, 1); 108 if (err) 109 return err; 110 /* FIXME: this cluster should be added after data of this 111 * cluster is writed */ 112 err = fat_chain_add(inode, cluster, 1); 113 if (err) 114 fat_free_clusters(inode, cluster); 115 return err; 116 } 117 118 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 119 unsigned long *max_blocks, 120 struct buffer_head *bh_result, int create) 121 { 122 struct super_block *sb = inode->i_sb; 123 struct msdos_sb_info *sbi = MSDOS_SB(sb); 124 unsigned long mapped_blocks; 125 sector_t phys, last_block; 126 int err, offset; 127 128 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 129 if (err) 130 return err; 131 if (phys) { 132 map_bh(bh_result, sb, phys); 133 *max_blocks = min(mapped_blocks, *max_blocks); 134 return 0; 135 } 136 if (!create) 137 return 0; 138 139 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 140 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 141 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 142 return -EIO; 143 } 144 145 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); 146 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 147 /* 148 * allocate a cluster according to the following. 149 * 1) no more available blocks 150 * 2) not part of fallocate region 151 */ 152 if (!offset && !(iblock < last_block)) { 153 /* TODO: multiple cluster allocation would be desirable. */ 154 err = fat_add_cluster(inode); 155 if (err) 156 return err; 157 } 158 /* available blocks on this cluster */ 159 mapped_blocks = sbi->sec_per_clus - offset; 160 161 *max_blocks = min(mapped_blocks, *max_blocks); 162 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 163 164 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 165 if (err) 166 return err; 167 if (!phys) { 168 fat_fs_error(sb, 169 "invalid FAT chain (i_pos %lld, last_block %llu)", 170 MSDOS_I(inode)->i_pos, 171 (unsigned long long)last_block); 172 return -EIO; 173 } 174 175 BUG_ON(*max_blocks != mapped_blocks); 176 set_buffer_new(bh_result); 177 map_bh(bh_result, sb, phys); 178 179 return 0; 180 } 181 182 static int fat_get_block(struct inode *inode, sector_t iblock, 183 struct buffer_head *bh_result, int create) 184 { 185 struct super_block *sb = inode->i_sb; 186 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 187 int err; 188 189 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 190 if (err) 191 return err; 192 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 193 return 0; 194 } 195 196 static int fat_writepages(struct address_space *mapping, 197 struct writeback_control *wbc) 198 { 199 return mpage_writepages(mapping, wbc, fat_get_block); 200 } 201 202 static int fat_read_folio(struct file *file, struct folio *folio) 203 { 204 return mpage_read_folio(folio, fat_get_block); 205 } 206 207 static void fat_readahead(struct readahead_control *rac) 208 { 209 mpage_readahead(rac, fat_get_block); 210 } 211 212 static void fat_write_failed(struct address_space *mapping, loff_t to) 213 { 214 struct inode *inode = mapping->host; 215 216 if (to > inode->i_size) { 217 truncate_pagecache(inode, inode->i_size); 218 fat_truncate_blocks(inode, inode->i_size); 219 } 220 } 221 222 static int fat_write_begin(const struct kiocb *iocb, 223 struct address_space *mapping, 224 loff_t pos, unsigned len, 225 struct folio **foliop, void **fsdata) 226 { 227 int err; 228 229 err = cont_write_begin(iocb, mapping, pos, len, 230 foliop, fsdata, fat_get_block, 231 &MSDOS_I(mapping->host)->mmu_private); 232 if (err < 0) 233 fat_write_failed(mapping, pos + len); 234 return err; 235 } 236 237 static int fat_write_end(const struct kiocb *iocb, 238 struct address_space *mapping, 239 loff_t pos, unsigned len, unsigned copied, 240 struct folio *folio, void *fsdata) 241 { 242 struct inode *inode = mapping->host; 243 int err; 244 err = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata); 245 if (err < len) 246 fat_write_failed(mapping, pos + len); 247 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 248 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 249 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 250 mark_inode_dirty(inode); 251 } 252 return err; 253 } 254 255 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 256 { 257 struct file *file = iocb->ki_filp; 258 struct address_space *mapping = file->f_mapping; 259 struct inode *inode = mapping->host; 260 size_t count = iov_iter_count(iter); 261 loff_t offset = iocb->ki_pos; 262 ssize_t ret; 263 264 if (iov_iter_rw(iter) == WRITE) { 265 /* 266 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 267 * so we need to update the ->mmu_private to block boundary. 268 * 269 * But we must fill the remaining area or hole by nul for 270 * updating ->mmu_private. 271 * 272 * Return 0, and fallback to normal buffered write. 273 */ 274 loff_t size = offset + count; 275 if (MSDOS_I(inode)->mmu_private < size) 276 return 0; 277 } 278 279 /* 280 * FAT need to use the DIO_LOCKING for avoiding the race 281 * condition of fat_get_block() and ->truncate(). 282 */ 283 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 284 if (ret < 0 && iov_iter_rw(iter) == WRITE) 285 fat_write_failed(mapping, offset + count); 286 287 return ret; 288 } 289 290 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 291 struct buffer_head *bh_result, int create) 292 { 293 struct super_block *sb = inode->i_sb; 294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 295 int err; 296 sector_t bmap; 297 unsigned long mapped_blocks; 298 299 BUG_ON(create != 0); 300 301 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 302 if (err) 303 return err; 304 305 if (bmap) { 306 map_bh(bh_result, sb, bmap); 307 max_blocks = min(mapped_blocks, max_blocks); 308 } 309 310 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 311 312 return 0; 313 } 314 315 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 316 { 317 sector_t blocknr; 318 319 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 320 down_read(&MSDOS_I(mapping->host)->truncate_lock); 321 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 322 up_read(&MSDOS_I(mapping->host)->truncate_lock); 323 324 return blocknr; 325 } 326 327 /* 328 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 329 * up to the end of the block which corresponds to `from'. 330 * This is required during truncate to physically zeroout the tail end 331 * of that block so it doesn't yield old data if the file is later grown. 332 * Also, avoid causing failure from fsx for cases of "data past EOF" 333 */ 334 int fat_block_truncate_page(struct inode *inode, loff_t from) 335 { 336 return block_truncate_page(inode->i_mapping, from, fat_get_block); 337 } 338 339 static const struct address_space_operations fat_aops = { 340 .dirty_folio = block_dirty_folio, 341 .invalidate_folio = block_invalidate_folio, 342 .read_folio = fat_read_folio, 343 .readahead = fat_readahead, 344 .writepages = fat_writepages, 345 .write_begin = fat_write_begin, 346 .write_end = fat_write_end, 347 .direct_IO = fat_direct_IO, 348 .bmap = _fat_bmap, 349 .migrate_folio = buffer_migrate_folio, 350 }; 351 352 /* 353 * New FAT inode stuff. We do the following: 354 * a) i_ino is constant and has nothing with on-disk location. 355 * b) FAT manages its own cache of directory entries. 356 * c) *This* cache is indexed by on-disk location. 357 * d) inode has an associated directory entry, all right, but 358 * it may be unhashed. 359 * e) currently entries are stored within struct inode. That should 360 * change. 361 * f) we deal with races in the following way: 362 * 1. readdir() and lookup() do FAT-dir-cache lookup. 363 * 2. rename() unhashes the F-d-c entry and rehashes it in 364 * a new place. 365 * 3. unlink() and rmdir() unhash F-d-c entry. 366 * 4. fat_write_inode() checks whether the thing is unhashed. 367 * If it is we silently return. If it isn't we do bread(), 368 * check if the location is still valid and retry if it 369 * isn't. Otherwise we do changes. 370 * 5. Spinlock is used to protect hash/unhash/location check/lookup 371 * 6. fat_evict_inode() unhashes the F-d-c entry. 372 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 373 * and consider negative result as cache miss. 374 */ 375 376 static void fat_hash_init(struct super_block *sb) 377 { 378 struct msdos_sb_info *sbi = MSDOS_SB(sb); 379 int i; 380 381 spin_lock_init(&sbi->inode_hash_lock); 382 for (i = 0; i < FAT_HASH_SIZE; i++) 383 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 384 } 385 386 static inline unsigned long fat_hash(loff_t i_pos) 387 { 388 return hash_32(i_pos, FAT_HASH_BITS); 389 } 390 391 static void dir_hash_init(struct super_block *sb) 392 { 393 struct msdos_sb_info *sbi = MSDOS_SB(sb); 394 int i; 395 396 spin_lock_init(&sbi->dir_hash_lock); 397 for (i = 0; i < FAT_HASH_SIZE; i++) 398 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 399 } 400 401 void fat_attach(struct inode *inode, loff_t i_pos) 402 { 403 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 404 405 if (inode->i_ino != MSDOS_ROOT_INO) { 406 struct hlist_head *head = sbi->inode_hashtable 407 + fat_hash(i_pos); 408 409 spin_lock(&sbi->inode_hash_lock); 410 MSDOS_I(inode)->i_pos = i_pos; 411 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 412 spin_unlock(&sbi->inode_hash_lock); 413 } 414 415 /* If NFS support is enabled, cache the mapping of start cluster 416 * to directory inode. This is used during reconnection of 417 * dentries to the filesystem root. 418 */ 419 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 420 struct hlist_head *d_head = sbi->dir_hashtable; 421 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 422 423 spin_lock(&sbi->dir_hash_lock); 424 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 425 spin_unlock(&sbi->dir_hash_lock); 426 } 427 } 428 EXPORT_SYMBOL_GPL(fat_attach); 429 430 void fat_detach(struct inode *inode) 431 { 432 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 433 spin_lock(&sbi->inode_hash_lock); 434 MSDOS_I(inode)->i_pos = 0; 435 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 436 spin_unlock(&sbi->inode_hash_lock); 437 438 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 439 spin_lock(&sbi->dir_hash_lock); 440 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 441 spin_unlock(&sbi->dir_hash_lock); 442 } 443 } 444 EXPORT_SYMBOL_GPL(fat_detach); 445 446 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 447 { 448 struct msdos_sb_info *sbi = MSDOS_SB(sb); 449 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 450 struct msdos_inode_info *i; 451 struct inode *inode = NULL; 452 453 spin_lock(&sbi->inode_hash_lock); 454 hlist_for_each_entry(i, head, i_fat_hash) { 455 BUG_ON(i->vfs_inode.i_sb != sb); 456 if (i->i_pos != i_pos) 457 continue; 458 inode = igrab(&i->vfs_inode); 459 if (inode) 460 break; 461 } 462 spin_unlock(&sbi->inode_hash_lock); 463 return inode; 464 } 465 466 static int is_exec(unsigned char *extension) 467 { 468 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 469 470 for (walk = exe_extensions; *walk; walk += 3) 471 if (!strncmp(extension, walk, 3)) 472 return 1; 473 return 0; 474 } 475 476 static int fat_calc_dir_size(struct inode *inode) 477 { 478 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 479 int ret, fclus, dclus; 480 481 inode->i_size = 0; 482 if (MSDOS_I(inode)->i_start == 0) 483 return 0; 484 485 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 486 if (ret < 0) 487 return ret; 488 inode->i_size = (fclus + 1) << sbi->cluster_bits; 489 490 return 0; 491 } 492 493 static int fat_validate_dir(struct inode *dir) 494 { 495 struct super_block *sb = dir->i_sb; 496 497 if (dir->i_nlink < 2) { 498 /* Directory should have "."/".." entries at least. */ 499 fat_fs_error(sb, "corrupted directory (invalid entries)"); 500 return -EIO; 501 } 502 if (MSDOS_I(dir)->i_start == 0 || 503 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 504 /* Directory should point valid cluster. */ 505 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 506 return -EIO; 507 } 508 return 0; 509 } 510 511 /* doesn't deal with root inode */ 512 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 513 { 514 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 515 struct timespec64 mtime; 516 int error; 517 518 MSDOS_I(inode)->i_pos = 0; 519 inode->i_uid = sbi->options.fs_uid; 520 inode->i_gid = sbi->options.fs_gid; 521 inode_inc_iversion(inode); 522 inode->i_generation = get_random_u32(); 523 524 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 525 inode->i_generation &= ~1; 526 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 527 inode->i_op = sbi->dir_ops; 528 inode->i_fop = &fat_dir_operations; 529 530 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 531 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 532 error = fat_calc_dir_size(inode); 533 if (error < 0) 534 return error; 535 MSDOS_I(inode)->mmu_private = inode->i_size; 536 537 set_nlink(inode, fat_subdirs(inode)); 538 539 error = fat_validate_dir(inode); 540 if (error < 0) 541 return error; 542 } else { /* not a directory */ 543 inode->i_generation |= 1; 544 inode->i_mode = fat_make_mode(sbi, de->attr, 545 ((sbi->options.showexec && !is_exec(de->name + 8)) 546 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 547 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 548 549 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 550 inode->i_size = le32_to_cpu(de->size); 551 inode->i_op = &fat_file_inode_operations; 552 inode->i_fop = &fat_file_operations; 553 inode->i_mapping->a_ops = &fat_aops; 554 MSDOS_I(inode)->mmu_private = inode->i_size; 555 } 556 if (de->attr & ATTR_SYS) { 557 if (sbi->options.sys_immutable) 558 inode->i_flags |= S_IMMUTABLE; 559 } 560 fat_save_attrs(inode, de->attr); 561 562 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 563 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 564 565 fat_time_fat2unix(sbi, &mtime, de->time, de->date, 0); 566 inode_set_mtime_to_ts(inode, mtime); 567 inode_set_ctime_to_ts(inode, mtime); 568 if (sbi->options.isvfat) { 569 struct timespec64 atime; 570 571 fat_time_fat2unix(sbi, &atime, 0, de->adate, 0); 572 inode_set_atime_to_ts(inode, atime); 573 fat_time_fat2unix(sbi, &MSDOS_I(inode)->i_crtime, de->ctime, 574 de->cdate, de->ctime_cs); 575 } else 576 inode_set_atime_to_ts(inode, fat_truncate_atime(sbi, &mtime)); 577 578 return 0; 579 } 580 581 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 582 { 583 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 584 mutex_lock(&sbi->nfs_build_inode_lock); 585 } 586 587 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 588 { 589 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 590 mutex_unlock(&sbi->nfs_build_inode_lock); 591 } 592 593 struct inode *fat_build_inode(struct super_block *sb, 594 struct msdos_dir_entry *de, loff_t i_pos) 595 { 596 struct inode *inode; 597 int err; 598 599 fat_lock_build_inode(MSDOS_SB(sb)); 600 inode = fat_iget(sb, i_pos); 601 if (inode) 602 goto out; 603 inode = new_inode(sb); 604 if (!inode) { 605 inode = ERR_PTR(-ENOMEM); 606 goto out; 607 } 608 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 609 inode_set_iversion(inode, 1); 610 err = fat_fill_inode(inode, de); 611 if (err) { 612 iput(inode); 613 inode = ERR_PTR(err); 614 goto out; 615 } 616 fat_attach(inode, i_pos); 617 insert_inode_hash(inode); 618 out: 619 fat_unlock_build_inode(MSDOS_SB(sb)); 620 return inode; 621 } 622 623 EXPORT_SYMBOL_GPL(fat_build_inode); 624 625 static int __fat_write_inode(struct inode *inode, int wait); 626 627 static void fat_free_eofblocks(struct inode *inode) 628 { 629 /* Release unwritten fallocated blocks on inode eviction. */ 630 if ((inode->i_blocks << 9) > 631 round_up(MSDOS_I(inode)->mmu_private, 632 MSDOS_SB(inode->i_sb)->cluster_size)) { 633 int err; 634 635 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 636 /* Fallocate results in updating the i_start/iogstart 637 * for the zero byte file. So, make it return to 638 * original state during evict and commit it to avoid 639 * any corruption on the next access to the cluster 640 * chain for the file. 641 */ 642 err = __fat_write_inode(inode, inode_needs_sync(inode)); 643 if (err) { 644 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 645 "update on disk inode for unused " 646 "fallocated blocks, inode could be " 647 "corrupted. Please run fsck"); 648 } 649 650 } 651 } 652 653 static void fat_evict_inode(struct inode *inode) 654 { 655 truncate_inode_pages_final(&inode->i_data); 656 if (!inode->i_nlink) { 657 inode->i_size = 0; 658 fat_truncate_blocks(inode, 0); 659 } else 660 fat_free_eofblocks(inode); 661 662 invalidate_inode_buffers(inode); 663 clear_inode(inode); 664 fat_cache_inval_inode(inode); 665 fat_detach(inode); 666 } 667 668 static void fat_set_state(struct super_block *sb, 669 unsigned int set, unsigned int force) 670 { 671 struct buffer_head *bh; 672 struct fat_boot_sector *b; 673 struct msdos_sb_info *sbi = MSDOS_SB(sb); 674 675 /* do not change any thing if mounted read only */ 676 if (sb_rdonly(sb) && !force) 677 return; 678 679 /* do not change state if fs was dirty */ 680 if (sbi->dirty) { 681 /* warn only on set (mount). */ 682 if (set) 683 fat_msg(sb, KERN_WARNING, "Volume was not properly " 684 "unmounted. Some data may be corrupt. " 685 "Please run fsck."); 686 return; 687 } 688 689 bh = sb_bread(sb, 0); 690 if (bh == NULL) { 691 fat_msg(sb, KERN_ERR, "unable to read boot sector " 692 "to mark fs as dirty"); 693 return; 694 } 695 696 b = (struct fat_boot_sector *) bh->b_data; 697 698 if (is_fat32(sbi)) { 699 if (set) 700 b->fat32.state |= FAT_STATE_DIRTY; 701 else 702 b->fat32.state &= ~FAT_STATE_DIRTY; 703 } else /* fat 16 and 12 */ { 704 if (set) 705 b->fat16.state |= FAT_STATE_DIRTY; 706 else 707 b->fat16.state &= ~FAT_STATE_DIRTY; 708 } 709 710 mark_buffer_dirty(bh); 711 sync_dirty_buffer(bh); 712 brelse(bh); 713 } 714 715 static void fat_reset_iocharset(struct fat_mount_options *opts) 716 { 717 if (opts->iocharset != fat_default_iocharset) { 718 /* Note: opts->iocharset can be NULL here */ 719 kfree(opts->iocharset); 720 opts->iocharset = fat_default_iocharset; 721 } 722 } 723 724 static void delayed_free(struct rcu_head *p) 725 { 726 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 727 unload_nls(sbi->nls_disk); 728 unload_nls(sbi->nls_io); 729 fat_reset_iocharset(&sbi->options); 730 kfree(sbi); 731 } 732 733 static void fat_put_super(struct super_block *sb) 734 { 735 struct msdos_sb_info *sbi = MSDOS_SB(sb); 736 737 fat_set_state(sb, 0, 0); 738 739 iput(sbi->fsinfo_inode); 740 iput(sbi->fat_inode); 741 742 call_rcu(&sbi->rcu, delayed_free); 743 } 744 745 static struct kmem_cache *fat_inode_cachep; 746 747 static struct inode *fat_alloc_inode(struct super_block *sb) 748 { 749 struct msdos_inode_info *ei; 750 ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS); 751 if (!ei) 752 return NULL; 753 754 init_rwsem(&ei->truncate_lock); 755 /* Zeroing to allow iput() even if partial initialized inode. */ 756 ei->mmu_private = 0; 757 ei->i_start = 0; 758 ei->i_logstart = 0; 759 ei->i_attrs = 0; 760 ei->i_pos = 0; 761 ei->i_crtime.tv_sec = 0; 762 ei->i_crtime.tv_nsec = 0; 763 764 return &ei->vfs_inode; 765 } 766 767 static void fat_free_inode(struct inode *inode) 768 { 769 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 770 } 771 772 static void init_once(void *foo) 773 { 774 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 775 776 spin_lock_init(&ei->cache_lru_lock); 777 ei->nr_caches = 0; 778 ei->cache_valid_id = FAT_CACHE_VALID + 1; 779 INIT_LIST_HEAD(&ei->cache_lru); 780 INIT_HLIST_NODE(&ei->i_fat_hash); 781 INIT_HLIST_NODE(&ei->i_dir_hash); 782 inode_init_once(&ei->vfs_inode); 783 } 784 785 static int __init fat_init_inodecache(void) 786 { 787 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 788 sizeof(struct msdos_inode_info), 789 0, (SLAB_RECLAIM_ACCOUNT| 790 SLAB_ACCOUNT), 791 init_once); 792 if (fat_inode_cachep == NULL) 793 return -ENOMEM; 794 return 0; 795 } 796 797 static void __exit fat_destroy_inodecache(void) 798 { 799 /* 800 * Make sure all delayed rcu free inodes are flushed before we 801 * destroy cache. 802 */ 803 rcu_barrier(); 804 kmem_cache_destroy(fat_inode_cachep); 805 } 806 807 int fat_reconfigure(struct fs_context *fc) 808 { 809 bool new_rdonly; 810 struct super_block *sb = fc->root->d_sb; 811 struct msdos_sb_info *sbi = MSDOS_SB(sb); 812 fc->sb_flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 813 814 sync_filesystem(sb); 815 816 /* make sure we update state on remount. */ 817 new_rdonly = fc->sb_flags & SB_RDONLY; 818 if (new_rdonly != sb_rdonly(sb)) { 819 if (new_rdonly) 820 fat_set_state(sb, 0, 0); 821 else 822 fat_set_state(sb, 1, 1); 823 } 824 return 0; 825 } 826 EXPORT_SYMBOL_GPL(fat_reconfigure); 827 828 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 829 { 830 struct super_block *sb = dentry->d_sb; 831 struct msdos_sb_info *sbi = MSDOS_SB(sb); 832 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 833 834 /* If the count of free cluster is still unknown, counts it here. */ 835 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 836 int err = fat_count_free_clusters(dentry->d_sb); 837 if (err) 838 return err; 839 } 840 841 buf->f_type = dentry->d_sb->s_magic; 842 buf->f_bsize = sbi->cluster_size; 843 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 844 buf->f_bfree = sbi->free_clusters; 845 buf->f_bavail = sbi->free_clusters; 846 buf->f_fsid = u64_to_fsid(id); 847 buf->f_namelen = 848 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 849 850 return 0; 851 } 852 853 static int __fat_write_inode(struct inode *inode, int wait) 854 { 855 struct super_block *sb = inode->i_sb; 856 struct msdos_sb_info *sbi = MSDOS_SB(sb); 857 struct buffer_head *bh; 858 struct msdos_dir_entry *raw_entry; 859 struct timespec64 mtime; 860 loff_t i_pos; 861 sector_t blocknr; 862 int err, offset; 863 864 if (inode->i_ino == MSDOS_ROOT_INO) 865 return 0; 866 867 retry: 868 i_pos = fat_i_pos_read(sbi, inode); 869 if (!i_pos) 870 return 0; 871 872 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 873 bh = sb_bread(sb, blocknr); 874 if (!bh) { 875 fat_msg(sb, KERN_ERR, "unable to read inode block " 876 "for updating (i_pos %lld)", i_pos); 877 return -EIO; 878 } 879 spin_lock(&sbi->inode_hash_lock); 880 if (i_pos != MSDOS_I(inode)->i_pos) { 881 spin_unlock(&sbi->inode_hash_lock); 882 brelse(bh); 883 goto retry; 884 } 885 886 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 887 if (S_ISDIR(inode->i_mode)) 888 raw_entry->size = 0; 889 else 890 raw_entry->size = cpu_to_le32(inode->i_size); 891 raw_entry->attr = fat_make_attrs(inode); 892 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 893 mtime = inode_get_mtime(inode); 894 fat_time_unix2fat(sbi, &mtime, &raw_entry->time, 895 &raw_entry->date, NULL); 896 if (sbi->options.isvfat) { 897 struct timespec64 ts = inode_get_atime(inode); 898 __le16 atime; 899 900 fat_time_unix2fat(sbi, &ts, &atime, &raw_entry->adate, NULL); 901 fat_time_unix2fat(sbi, &MSDOS_I(inode)->i_crtime, &raw_entry->ctime, 902 &raw_entry->cdate, &raw_entry->ctime_cs); 903 } 904 spin_unlock(&sbi->inode_hash_lock); 905 mark_buffer_dirty(bh); 906 err = 0; 907 if (wait) 908 err = sync_dirty_buffer(bh); 909 brelse(bh); 910 return err; 911 } 912 913 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 914 { 915 int err; 916 917 if (inode->i_ino == MSDOS_FSINFO_INO) { 918 struct super_block *sb = inode->i_sb; 919 920 mutex_lock(&MSDOS_SB(sb)->s_lock); 921 err = fat_clusters_flush(sb); 922 mutex_unlock(&MSDOS_SB(sb)->s_lock); 923 } else 924 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 925 926 return err; 927 } 928 929 int fat_sync_inode(struct inode *inode) 930 { 931 return __fat_write_inode(inode, 1); 932 } 933 934 EXPORT_SYMBOL_GPL(fat_sync_inode); 935 936 static int fat_show_options(struct seq_file *m, struct dentry *root); 937 static const struct super_operations fat_sops = { 938 .alloc_inode = fat_alloc_inode, 939 .free_inode = fat_free_inode, 940 .write_inode = fat_write_inode, 941 .evict_inode = fat_evict_inode, 942 .put_super = fat_put_super, 943 .statfs = fat_statfs, 944 .show_options = fat_show_options, 945 }; 946 947 static int fat_show_options(struct seq_file *m, struct dentry *root) 948 { 949 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 950 struct fat_mount_options *opts = &sbi->options; 951 int isvfat = opts->isvfat; 952 953 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 954 seq_printf(m, ",uid=%u", 955 from_kuid_munged(&init_user_ns, opts->fs_uid)); 956 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 957 seq_printf(m, ",gid=%u", 958 from_kgid_munged(&init_user_ns, opts->fs_gid)); 959 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 960 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 961 if (opts->allow_utime) 962 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 963 if (sbi->nls_disk) 964 /* strip "cp" prefix from displayed option */ 965 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 966 if (isvfat) { 967 if (sbi->nls_io) 968 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 969 970 switch (opts->shortname) { 971 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 972 seq_puts(m, ",shortname=win95"); 973 break; 974 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 975 seq_puts(m, ",shortname=winnt"); 976 break; 977 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 978 seq_puts(m, ",shortname=mixed"); 979 break; 980 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 981 seq_puts(m, ",shortname=lower"); 982 break; 983 default: 984 seq_puts(m, ",shortname=unknown"); 985 break; 986 } 987 } 988 if (opts->name_check != 'n') 989 seq_printf(m, ",check=%c", opts->name_check); 990 if (opts->usefree) 991 seq_puts(m, ",usefree"); 992 if (opts->quiet) 993 seq_puts(m, ",quiet"); 994 if (opts->showexec) 995 seq_puts(m, ",showexec"); 996 if (opts->sys_immutable) 997 seq_puts(m, ",sys_immutable"); 998 if (!isvfat) { 999 if (opts->dotsOK) 1000 seq_puts(m, ",dotsOK=yes"); 1001 if (opts->nocase) 1002 seq_puts(m, ",nocase"); 1003 } else { 1004 if (opts->utf8) 1005 seq_puts(m, ",utf8"); 1006 if (opts->unicode_xlate) 1007 seq_puts(m, ",uni_xlate"); 1008 if (!opts->numtail) 1009 seq_puts(m, ",nonumtail"); 1010 if (opts->rodir) 1011 seq_puts(m, ",rodir"); 1012 } 1013 if (opts->flush) 1014 seq_puts(m, ",flush"); 1015 if (opts->tz_set) { 1016 if (opts->time_offset) 1017 seq_printf(m, ",time_offset=%d", opts->time_offset); 1018 else 1019 seq_puts(m, ",tz=UTC"); 1020 } 1021 if (opts->errors == FAT_ERRORS_CONT) 1022 seq_puts(m, ",errors=continue"); 1023 else if (opts->errors == FAT_ERRORS_PANIC) 1024 seq_puts(m, ",errors=panic"); 1025 else 1026 seq_puts(m, ",errors=remount-ro"); 1027 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1028 seq_puts(m, ",nfs=nostale_ro"); 1029 else if (opts->nfs) 1030 seq_puts(m, ",nfs=stale_rw"); 1031 if (opts->discard) 1032 seq_puts(m, ",discard"); 1033 if (opts->dos1xfloppy) 1034 seq_puts(m, ",dos1xfloppy"); 1035 1036 return 0; 1037 } 1038 1039 enum { 1040 Opt_check, Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, 1041 Opt_allow_utime, Opt_codepage, Opt_usefree, Opt_nocase, Opt_quiet, 1042 Opt_showexec, Opt_debug, Opt_immutable, Opt_dots, Opt_dotsOK, 1043 Opt_charset, Opt_shortname, Opt_utf8, Opt_utf8_bool, 1044 Opt_uni_xl, Opt_uni_xl_bool, Opt_nonumtail, Opt_nonumtail_bool, 1045 Opt_obsolete, Opt_flush, Opt_tz, Opt_rodir, Opt_errors, Opt_discard, 1046 Opt_nfs, Opt_nfs_enum, Opt_time_offset, Opt_dos1xfloppy, 1047 }; 1048 1049 static const struct constant_table fat_param_check[] = { 1050 {"relaxed", 'r'}, 1051 {"r", 'r'}, 1052 {"strict", 's'}, 1053 {"s", 's'}, 1054 {"normal", 'n'}, 1055 {"n", 'n'}, 1056 {} 1057 }; 1058 1059 static const struct constant_table fat_param_tz[] = { 1060 {"UTC", 0}, 1061 {} 1062 }; 1063 1064 static const struct constant_table fat_param_errors[] = { 1065 {"continue", FAT_ERRORS_CONT}, 1066 {"panic", FAT_ERRORS_PANIC}, 1067 {"remount-ro", FAT_ERRORS_RO}, 1068 {} 1069 }; 1070 1071 1072 static const struct constant_table fat_param_nfs[] = { 1073 {"stale_rw", FAT_NFS_STALE_RW}, 1074 {"nostale_ro", FAT_NFS_NOSTALE_RO}, 1075 {} 1076 }; 1077 1078 /* 1079 * These are all obsolete but we still reject invalid options. 1080 * The corresponding values are therefore meaningless. 1081 */ 1082 static const struct constant_table fat_param_conv[] = { 1083 {"binary", 0}, 1084 {"text", 0}, 1085 {"auto", 0}, 1086 {"b", 0}, 1087 {"t", 0}, 1088 {"a", 0}, 1089 {} 1090 }; 1091 1092 /* Core options. See below for vfat and msdos extras */ 1093 const struct fs_parameter_spec fat_param_spec[] = { 1094 fsparam_enum ("check", Opt_check, fat_param_check), 1095 fsparam_uid ("uid", Opt_uid), 1096 fsparam_gid ("gid", Opt_gid), 1097 fsparam_u32oct ("umask", Opt_umask), 1098 fsparam_u32oct ("dmask", Opt_dmask), 1099 fsparam_u32oct ("fmask", Opt_fmask), 1100 fsparam_u32oct ("allow_utime", Opt_allow_utime), 1101 fsparam_u32 ("codepage", Opt_codepage), 1102 fsparam_flag ("usefree", Opt_usefree), 1103 fsparam_flag ("nocase", Opt_nocase), 1104 fsparam_flag ("quiet", Opt_quiet), 1105 fsparam_flag ("showexec", Opt_showexec), 1106 fsparam_flag ("debug", Opt_debug), 1107 fsparam_flag ("sys_immutable", Opt_immutable), 1108 fsparam_flag ("flush", Opt_flush), 1109 fsparam_enum ("tz", Opt_tz, fat_param_tz), 1110 fsparam_s32 ("time_offset", Opt_time_offset), 1111 fsparam_enum ("errors", Opt_errors, fat_param_errors), 1112 fsparam_flag ("discard", Opt_discard), 1113 fsparam_flag ("nfs", Opt_nfs), 1114 fsparam_enum ("nfs", Opt_nfs_enum, fat_param_nfs), 1115 fsparam_flag ("dos1xfloppy", Opt_dos1xfloppy), 1116 __fsparam(fs_param_is_enum, "conv", 1117 Opt_obsolete, fs_param_deprecated, fat_param_conv), 1118 __fsparam(fs_param_is_u32, "fat", 1119 Opt_obsolete, fs_param_deprecated, NULL), 1120 __fsparam(fs_param_is_u32, "blocksize", 1121 Opt_obsolete, fs_param_deprecated, NULL), 1122 __fsparam(fs_param_is_string, "cvf_format", 1123 Opt_obsolete, fs_param_deprecated, NULL), 1124 __fsparam(fs_param_is_string, "cvf_options", 1125 Opt_obsolete, fs_param_deprecated, NULL), 1126 __fsparam(NULL, "posix", 1127 Opt_obsolete, fs_param_deprecated, NULL), 1128 {} 1129 }; 1130 EXPORT_SYMBOL_GPL(fat_param_spec); 1131 1132 static const struct fs_parameter_spec msdos_param_spec[] = { 1133 fsparam_flag_no ("dots", Opt_dots), 1134 fsparam_bool ("dotsOK", Opt_dotsOK), 1135 {} 1136 }; 1137 1138 static const struct constant_table fat_param_shortname[] = { 1139 {"lower", VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95}, 1140 {"win95", VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95}, 1141 {"winnt", VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT}, 1142 {"mixed", VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95}, 1143 {} 1144 }; 1145 1146 static const struct fs_parameter_spec vfat_param_spec[] = { 1147 fsparam_string ("iocharset", Opt_charset), 1148 fsparam_enum ("shortname", Opt_shortname, fat_param_shortname), 1149 fsparam_flag ("utf8", Opt_utf8), 1150 fsparam_bool ("utf8", Opt_utf8_bool), 1151 fsparam_flag ("uni_xlate", Opt_uni_xl), 1152 fsparam_bool ("uni_xlate", Opt_uni_xl_bool), 1153 fsparam_flag ("nonumtail", Opt_nonumtail), 1154 fsparam_bool ("nonumtail", Opt_nonumtail_bool), 1155 fsparam_flag ("rodir", Opt_rodir), 1156 {} 1157 }; 1158 1159 int fat_parse_param(struct fs_context *fc, struct fs_parameter *param, 1160 bool is_vfat) 1161 { 1162 struct fat_mount_options *opts = fc->fs_private; 1163 struct fs_parse_result result; 1164 int opt; 1165 1166 /* remount options have traditionally been ignored */ 1167 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) 1168 return 0; 1169 1170 opt = fs_parse(fc, fat_param_spec, param, &result); 1171 /* If option not found in fat_param_spec, try vfat/msdos options */ 1172 if (opt == -ENOPARAM) { 1173 if (is_vfat) 1174 opt = fs_parse(fc, vfat_param_spec, param, &result); 1175 else 1176 opt = fs_parse(fc, msdos_param_spec, param, &result); 1177 } 1178 1179 if (opt < 0) 1180 return opt; 1181 1182 switch (opt) { 1183 case Opt_check: 1184 opts->name_check = result.uint_32; 1185 break; 1186 case Opt_usefree: 1187 opts->usefree = 1; 1188 break; 1189 case Opt_nocase: 1190 if (!is_vfat) 1191 opts->nocase = 1; 1192 else { 1193 /* for backward compatibility */ 1194 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1195 | VFAT_SFN_CREATE_WIN95; 1196 } 1197 break; 1198 case Opt_quiet: 1199 opts->quiet = 1; 1200 break; 1201 case Opt_showexec: 1202 opts->showexec = 1; 1203 break; 1204 case Opt_debug: 1205 opts->debug = 1; 1206 break; 1207 case Opt_immutable: 1208 opts->sys_immutable = 1; 1209 break; 1210 case Opt_uid: 1211 opts->fs_uid = result.uid; 1212 break; 1213 case Opt_gid: 1214 opts->fs_gid = result.gid; 1215 break; 1216 case Opt_umask: 1217 opts->fs_fmask = opts->fs_dmask = result.uint_32; 1218 break; 1219 case Opt_dmask: 1220 opts->fs_dmask = result.uint_32; 1221 break; 1222 case Opt_fmask: 1223 opts->fs_fmask = result.uint_32; 1224 break; 1225 case Opt_allow_utime: 1226 opts->allow_utime = result.uint_32 & (S_IWGRP | S_IWOTH); 1227 break; 1228 case Opt_codepage: 1229 opts->codepage = result.uint_32; 1230 break; 1231 case Opt_flush: 1232 opts->flush = 1; 1233 break; 1234 case Opt_time_offset: 1235 /* 1236 * GMT+-12 zones may have DST corrections so at least 1237 * 13 hours difference is needed. Make the limit 24 1238 * just in case someone invents something unusual. 1239 */ 1240 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) 1241 return -EINVAL; 1242 opts->tz_set = 1; 1243 opts->time_offset = result.int_32; 1244 break; 1245 case Opt_tz: 1246 opts->tz_set = 1; 1247 opts->time_offset = result.uint_32; 1248 break; 1249 case Opt_errors: 1250 opts->errors = result.uint_32; 1251 break; 1252 case Opt_nfs: 1253 opts->nfs = FAT_NFS_STALE_RW; 1254 break; 1255 case Opt_nfs_enum: 1256 opts->nfs = result.uint_32; 1257 break; 1258 case Opt_dos1xfloppy: 1259 opts->dos1xfloppy = 1; 1260 break; 1261 1262 /* msdos specific */ 1263 case Opt_dots: /* dots / nodots */ 1264 opts->dotsOK = !result.negated; 1265 break; 1266 case Opt_dotsOK: /* dotsOK = yes/no */ 1267 opts->dotsOK = result.boolean; 1268 break; 1269 1270 /* vfat specific */ 1271 case Opt_charset: 1272 fat_reset_iocharset(opts); 1273 opts->iocharset = param->string; 1274 param->string = NULL; /* Steal string */ 1275 break; 1276 case Opt_shortname: 1277 opts->shortname = result.uint_32; 1278 break; 1279 case Opt_utf8: 1280 opts->utf8 = 1; 1281 break; 1282 case Opt_utf8_bool: 1283 opts->utf8 = result.boolean; 1284 break; 1285 case Opt_uni_xl: 1286 opts->unicode_xlate = 1; 1287 break; 1288 case Opt_uni_xl_bool: 1289 opts->unicode_xlate = result.boolean; 1290 break; 1291 case Opt_nonumtail: 1292 opts->numtail = 0; /* negated option */ 1293 break; 1294 case Opt_nonumtail_bool: 1295 opts->numtail = !result.boolean; /* negated option */ 1296 break; 1297 case Opt_rodir: 1298 opts->rodir = 1; 1299 break; 1300 case Opt_discard: 1301 opts->discard = 1; 1302 break; 1303 1304 /* obsolete mount options */ 1305 case Opt_obsolete: 1306 printk(KERN_INFO "FAT-fs: \"%s\" option is obsolete, " 1307 "not supported now", param->key); 1308 break; 1309 default: 1310 return -EINVAL; 1311 } 1312 1313 return 0; 1314 } 1315 EXPORT_SYMBOL_GPL(fat_parse_param); 1316 1317 static int fat_read_root(struct inode *inode) 1318 { 1319 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1320 int error; 1321 1322 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1323 inode->i_uid = sbi->options.fs_uid; 1324 inode->i_gid = sbi->options.fs_gid; 1325 inode_inc_iversion(inode); 1326 inode->i_generation = 0; 1327 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1328 inode->i_op = sbi->dir_ops; 1329 inode->i_fop = &fat_dir_operations; 1330 if (is_fat32(sbi)) { 1331 MSDOS_I(inode)->i_start = sbi->root_cluster; 1332 error = fat_calc_dir_size(inode); 1333 if (error < 0) 1334 return error; 1335 } else { 1336 MSDOS_I(inode)->i_start = 0; 1337 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1338 } 1339 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1340 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1341 MSDOS_I(inode)->i_logstart = 0; 1342 MSDOS_I(inode)->mmu_private = inode->i_size; 1343 1344 fat_save_attrs(inode, ATTR_DIR); 1345 inode_set_mtime_to_ts(inode, 1346 inode_set_atime_to_ts(inode, inode_set_ctime(inode, 0, 0))); 1347 set_nlink(inode, fat_subdirs(inode)+2); 1348 1349 return 0; 1350 } 1351 1352 static unsigned long calc_fat_clusters(struct super_block *sb) 1353 { 1354 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1355 1356 /* Divide first to avoid overflow */ 1357 if (!is_fat12(sbi)) { 1358 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1359 return ent_per_sec * sbi->fat_length; 1360 } 1361 1362 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1363 } 1364 1365 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1366 { 1367 if (get_unaligned_le16(&b->sector_size)) 1368 return false; 1369 if (b->sec_per_clus) 1370 return false; 1371 if (b->reserved) 1372 return false; 1373 if (b->fats) 1374 return false; 1375 if (get_unaligned_le16(&b->dir_entries)) 1376 return false; 1377 if (get_unaligned_le16(&b->sectors)) 1378 return false; 1379 if (b->media) 1380 return false; 1381 if (b->fat_length) 1382 return false; 1383 if (b->secs_track) 1384 return false; 1385 if (b->heads) 1386 return false; 1387 return true; 1388 } 1389 1390 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1391 int silent, struct fat_bios_param_block *bpb) 1392 { 1393 int error = -EINVAL; 1394 1395 /* Read in BPB ... */ 1396 memset(bpb, 0, sizeof(*bpb)); 1397 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1398 bpb->fat_sec_per_clus = b->sec_per_clus; 1399 bpb->fat_reserved = le16_to_cpu(b->reserved); 1400 bpb->fat_fats = b->fats; 1401 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1402 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1403 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1404 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1405 1406 bpb->fat16_state = b->fat16.state; 1407 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1408 1409 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1410 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1411 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1412 bpb->fat32_state = b->fat32.state; 1413 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1414 1415 /* Validate this looks like a FAT filesystem BPB */ 1416 if (!bpb->fat_reserved) { 1417 if (!silent) 1418 fat_msg(sb, KERN_ERR, 1419 "bogus number of reserved sectors"); 1420 goto out; 1421 } 1422 if (!bpb->fat_fats) { 1423 if (!silent) 1424 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1425 goto out; 1426 } 1427 1428 /* 1429 * Earlier we checked here that b->secs_track and b->head are nonzero, 1430 * but it turns out valid FAT filesystems can have zero there. 1431 */ 1432 1433 if (!fat_valid_media(b->media)) { 1434 if (!silent) 1435 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1436 (unsigned)b->media); 1437 goto out; 1438 } 1439 1440 if (!is_power_of_2(bpb->fat_sector_size) 1441 || (bpb->fat_sector_size < 512) 1442 || (bpb->fat_sector_size > 4096)) { 1443 if (!silent) 1444 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1445 (unsigned)bpb->fat_sector_size); 1446 goto out; 1447 } 1448 1449 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1450 if (!silent) 1451 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1452 (unsigned)bpb->fat_sec_per_clus); 1453 goto out; 1454 } 1455 1456 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1457 if (!silent) 1458 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1459 goto out; 1460 } 1461 1462 error = 0; 1463 1464 out: 1465 return error; 1466 } 1467 1468 static int fat_read_static_bpb(struct super_block *sb, 1469 struct fat_boot_sector *b, int silent, 1470 struct fat_bios_param_block *bpb) 1471 { 1472 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1473 sector_t bd_sects = bdev_nr_sectors(sb->s_bdev); 1474 struct fat_floppy_defaults *fdefaults = NULL; 1475 int error = -EINVAL; 1476 unsigned i; 1477 1478 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1479 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1480 if (!silent) 1481 fat_msg(sb, KERN_ERR, 1482 "%s; no bootstrapping code", notdos1x); 1483 goto out; 1484 } 1485 1486 /* 1487 * If any value in this region is non-zero, it isn't archaic 1488 * DOS. 1489 */ 1490 if (!fat_bpb_is_zero(b)) { 1491 if (!silent) 1492 fat_msg(sb, KERN_ERR, 1493 "%s; DOS 2.x BPB is non-zero", notdos1x); 1494 goto out; 1495 } 1496 1497 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1498 if (floppy_defaults[i].nr_sectors == bd_sects) { 1499 fdefaults = &floppy_defaults[i]; 1500 break; 1501 } 1502 } 1503 1504 if (fdefaults == NULL) { 1505 if (!silent) 1506 fat_msg(sb, KERN_WARNING, 1507 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1508 (u64)bd_sects); 1509 goto out; 1510 } 1511 1512 if (!silent) 1513 fat_msg(sb, KERN_INFO, 1514 "This looks like a DOS 1.x volume; assuming default BPB values"); 1515 1516 memset(bpb, 0, sizeof(*bpb)); 1517 bpb->fat_sector_size = SECTOR_SIZE; 1518 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1519 bpb->fat_reserved = 1; 1520 bpb->fat_fats = 2; 1521 bpb->fat_dir_entries = fdefaults->dir_entries; 1522 bpb->fat_sectors = fdefaults->nr_sectors; 1523 bpb->fat_fat_length = fdefaults->fat_length; 1524 1525 error = 0; 1526 1527 out: 1528 return error; 1529 } 1530 1531 /* 1532 * Read the super block of an MS-DOS FS. 1533 */ 1534 int fat_fill_super(struct super_block *sb, struct fs_context *fc, 1535 void (*setup)(struct super_block *)) 1536 { 1537 struct fat_mount_options *opts = fc->fs_private; 1538 int silent = fc->sb_flags & SB_SILENT; 1539 struct inode *root_inode = NULL, *fat_inode = NULL; 1540 struct inode *fsinfo_inode = NULL; 1541 struct buffer_head *bh; 1542 struct fat_bios_param_block bpb; 1543 struct msdos_sb_info *sbi; 1544 u16 logical_sector_size; 1545 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1546 long error; 1547 char buf[50]; 1548 struct timespec64 ts; 1549 1550 /* 1551 * GFP_KERNEL is ok here, because while we do hold the 1552 * superblock lock, memory pressure can't call back into 1553 * the filesystem, since we're only just about to mount 1554 * it and have no inodes etc active! 1555 */ 1556 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1557 if (!sbi) 1558 return -ENOMEM; 1559 sb->s_fs_info = sbi; 1560 1561 sb->s_flags |= SB_NODIRATIME; 1562 sb->s_magic = MSDOS_SUPER_MAGIC; 1563 sb->s_op = &fat_sops; 1564 sb->s_export_op = &fat_export_ops; 1565 /* 1566 * fat timestamps are complex and truncated by fat itself, so 1567 * we set 1 here to be fast 1568 */ 1569 sb->s_time_gran = 1; 1570 mutex_init(&sbi->nfs_build_inode_lock); 1571 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1572 DEFAULT_RATELIMIT_BURST); 1573 1574 /* UTF-8 doesn't provide FAT semantics */ 1575 if (!strcmp(opts->iocharset, "utf8")) { 1576 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1577 " for FAT filesystems, filesystem will be" 1578 " case sensitive!"); 1579 } 1580 1581 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1582 if (opts->allow_utime == (unsigned short)-1) 1583 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1584 if (opts->unicode_xlate) 1585 opts->utf8 = 0; 1586 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1587 sb->s_flags |= SB_RDONLY; 1588 sb->s_export_op = &fat_export_ops_nostale; 1589 } 1590 1591 /* Apply parsed options to sbi (structure copy) */ 1592 sbi->options = *opts; 1593 /* Transfer ownership of iocharset to sbi->options */ 1594 opts->iocharset = NULL; 1595 1596 setup(sb); /* flavour-specific stuff that needs options */ 1597 1598 error = -EIO; 1599 sb_min_blocksize(sb, 512); 1600 bh = sb_bread(sb, 0); 1601 if (bh == NULL) { 1602 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1603 goto out_fail; 1604 } 1605 1606 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1607 &bpb); 1608 if (error == -EINVAL && sbi->options.dos1xfloppy) 1609 error = fat_read_static_bpb(sb, 1610 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1611 brelse(bh); 1612 1613 if (error == -EINVAL) 1614 goto out_invalid; 1615 else if (error) 1616 goto out_fail; 1617 1618 logical_sector_size = bpb.fat_sector_size; 1619 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1620 1621 error = -EIO; 1622 if (logical_sector_size < sb->s_blocksize) { 1623 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1624 " (logical sector size = %u)", logical_sector_size); 1625 goto out_fail; 1626 } 1627 1628 if (logical_sector_size > sb->s_blocksize) { 1629 struct buffer_head *bh_resize; 1630 1631 if (!sb_set_blocksize(sb, logical_sector_size)) { 1632 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1633 logical_sector_size); 1634 goto out_fail; 1635 } 1636 1637 /* Verify that the larger boot sector is fully readable */ 1638 bh_resize = sb_bread(sb, 0); 1639 if (bh_resize == NULL) { 1640 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1641 " (logical sector size = %lu)", 1642 sb->s_blocksize); 1643 goto out_fail; 1644 } 1645 brelse(bh_resize); 1646 } 1647 1648 mutex_init(&sbi->s_lock); 1649 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1650 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1651 sbi->fats = bpb.fat_fats; 1652 sbi->fat_bits = 0; /* Don't know yet */ 1653 sbi->fat_start = bpb.fat_reserved; 1654 sbi->fat_length = bpb.fat_fat_length; 1655 sbi->root_cluster = 0; 1656 sbi->free_clusters = -1; /* Don't know yet */ 1657 sbi->free_clus_valid = 0; 1658 sbi->prev_free = FAT_START_ENT; 1659 sb->s_maxbytes = 0xffffffff; 1660 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1661 sb->s_time_min = ts.tv_sec; 1662 1663 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1664 cpu_to_le16(FAT_DATE_MAX), 0); 1665 sb->s_time_max = ts.tv_sec; 1666 1667 if (!sbi->fat_length && bpb.fat32_length) { 1668 struct fat_boot_fsinfo *fsinfo; 1669 struct buffer_head *fsinfo_bh; 1670 1671 /* Must be FAT32 */ 1672 sbi->fat_bits = 32; 1673 sbi->fat_length = bpb.fat32_length; 1674 sbi->root_cluster = bpb.fat32_root_cluster; 1675 1676 /* MC - if info_sector is 0, don't multiply by 0 */ 1677 sbi->fsinfo_sector = bpb.fat32_info_sector; 1678 if (sbi->fsinfo_sector == 0) 1679 sbi->fsinfo_sector = 1; 1680 1681 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1682 if (fsinfo_bh == NULL) { 1683 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1684 " (sector = %lu)", sbi->fsinfo_sector); 1685 goto out_fail; 1686 } 1687 1688 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1689 if (!IS_FSINFO(fsinfo)) { 1690 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1691 "0x%08x, 0x%08x (sector = %lu)", 1692 le32_to_cpu(fsinfo->signature1), 1693 le32_to_cpu(fsinfo->signature2), 1694 sbi->fsinfo_sector); 1695 } else { 1696 if (sbi->options.usefree) 1697 sbi->free_clus_valid = 1; 1698 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1699 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1700 } 1701 1702 brelse(fsinfo_bh); 1703 } 1704 1705 /* interpret volume ID as a little endian 32 bit integer */ 1706 if (is_fat32(sbi)) 1707 sbi->vol_id = bpb.fat32_vol_id; 1708 else /* fat 16 or 12 */ 1709 sbi->vol_id = bpb.fat16_vol_id; 1710 1711 __le32 vol_id_le = cpu_to_le32(sbi->vol_id); 1712 super_set_uuid(sb, (void *) &vol_id_le, sizeof(vol_id_le)); 1713 1714 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1715 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1716 1717 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1718 sbi->dir_entries = bpb.fat_dir_entries; 1719 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1720 if (!silent) 1721 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1722 " (%u)", sbi->dir_entries); 1723 goto out_invalid; 1724 } 1725 1726 rootdir_sectors = sbi->dir_entries 1727 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1728 sbi->data_start = sbi->dir_start + rootdir_sectors; 1729 total_sectors = bpb.fat_sectors; 1730 if (total_sectors == 0) 1731 total_sectors = bpb.fat_total_sect; 1732 1733 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1734 1735 if (!is_fat32(sbi)) 1736 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1737 1738 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1739 if (is_fat32(sbi)) 1740 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1741 else /* fat 16 or 12 */ 1742 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1743 1744 /* check that FAT table does not overflow */ 1745 fat_clusters = calc_fat_clusters(sb); 1746 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1747 if (total_clusters > max_fat(sb)) { 1748 if (!silent) 1749 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1750 total_clusters); 1751 goto out_invalid; 1752 } 1753 1754 sbi->max_cluster = total_clusters + FAT_START_ENT; 1755 /* check the free_clusters, it's not necessarily correct */ 1756 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1757 sbi->free_clusters = -1; 1758 /* check the prev_free, it's not necessarily correct */ 1759 sbi->prev_free %= sbi->max_cluster; 1760 if (sbi->prev_free < FAT_START_ENT) 1761 sbi->prev_free = FAT_START_ENT; 1762 1763 /* set up enough so that it can read an inode */ 1764 fat_hash_init(sb); 1765 dir_hash_init(sb); 1766 fat_ent_access_init(sb); 1767 1768 /* 1769 * The low byte of the first FAT entry must have the same value as 1770 * the media field of the boot sector. But in real world, too many 1771 * devices are writing wrong values. So, removed that validity check. 1772 * 1773 * The removed check compared the first FAT entry to a value dependent 1774 * on the media field like this: 1775 * == (0x0F00 | media), for FAT12 1776 * == (0XFF00 | media), for FAT16 1777 * == (0x0FFFFF | media), for FAT32 1778 */ 1779 1780 error = -EINVAL; 1781 sprintf(buf, "cp%d", sbi->options.codepage); 1782 sbi->nls_disk = load_nls(buf); 1783 if (!sbi->nls_disk) { 1784 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1785 goto out_fail; 1786 } 1787 1788 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1789 if (sbi->options.isvfat) { 1790 sbi->nls_io = load_nls(sbi->options.iocharset); 1791 if (!sbi->nls_io) { 1792 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1793 sbi->options.iocharset); 1794 goto out_fail; 1795 } 1796 } 1797 1798 error = -ENOMEM; 1799 fat_inode = new_inode(sb); 1800 if (!fat_inode) 1801 goto out_fail; 1802 sbi->fat_inode = fat_inode; 1803 1804 fsinfo_inode = new_inode(sb); 1805 if (!fsinfo_inode) 1806 goto out_fail; 1807 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1808 sbi->fsinfo_inode = fsinfo_inode; 1809 insert_inode_hash(fsinfo_inode); 1810 1811 root_inode = new_inode(sb); 1812 if (!root_inode) 1813 goto out_fail; 1814 root_inode->i_ino = MSDOS_ROOT_INO; 1815 inode_set_iversion(root_inode, 1); 1816 error = fat_read_root(root_inode); 1817 if (error < 0) { 1818 iput(root_inode); 1819 goto out_fail; 1820 } 1821 error = -ENOMEM; 1822 insert_inode_hash(root_inode); 1823 fat_attach(root_inode, 0); 1824 sb->s_root = d_make_root(root_inode); 1825 if (!sb->s_root) { 1826 fat_msg(sb, KERN_ERR, "get root inode failed"); 1827 goto out_fail; 1828 } 1829 1830 if (sbi->options.discard && !bdev_max_discard_sectors(sb->s_bdev)) 1831 fat_msg(sb, KERN_WARNING, 1832 "mounting with \"discard\" option, but the device does not support discard"); 1833 1834 fat_set_state(sb, 1, 0); 1835 return 0; 1836 1837 out_invalid: 1838 error = -EINVAL; 1839 if (!silent) 1840 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1841 1842 out_fail: 1843 iput(fsinfo_inode); 1844 iput(fat_inode); 1845 unload_nls(sbi->nls_io); 1846 unload_nls(sbi->nls_disk); 1847 fat_reset_iocharset(&sbi->options); 1848 sb->s_fs_info = NULL; 1849 kfree(sbi); 1850 return error; 1851 } 1852 1853 EXPORT_SYMBOL_GPL(fat_fill_super); 1854 1855 /* 1856 * helper function for fat_flush_inodes. This writes both the inode 1857 * and the file data blocks, waiting for in flight data blocks before 1858 * the start of the call. It does not wait for any io started 1859 * during the call 1860 */ 1861 static int writeback_inode(struct inode *inode) 1862 { 1863 1864 int ret; 1865 1866 /* if we used wait=1, sync_inode_metadata waits for the io for the 1867 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1868 * and filemap_fdatawrite is used for the data blocks 1869 */ 1870 ret = sync_inode_metadata(inode, 0); 1871 if (!ret) 1872 ret = filemap_fdatawrite(inode->i_mapping); 1873 return ret; 1874 } 1875 1876 /* 1877 * write data and metadata corresponding to i1 and i2. The io is 1878 * started but we do not wait for any of it to finish. 1879 * 1880 * filemap_flush is used for the block device, so if there is a dirty 1881 * page for a block already in flight, we will not wait and start the 1882 * io over again 1883 */ 1884 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1885 { 1886 int ret = 0; 1887 if (!MSDOS_SB(sb)->options.flush) 1888 return 0; 1889 if (i1) 1890 ret = writeback_inode(i1); 1891 if (!ret && i2) 1892 ret = writeback_inode(i2); 1893 if (!ret) 1894 ret = sync_blockdev_nowait(sb->s_bdev); 1895 return ret; 1896 } 1897 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1898 1899 int fat_init_fs_context(struct fs_context *fc, bool is_vfat) 1900 { 1901 struct fat_mount_options *opts; 1902 1903 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 1904 if (!opts) 1905 return -ENOMEM; 1906 1907 opts->isvfat = is_vfat; 1908 opts->fs_uid = current_uid(); 1909 opts->fs_gid = current_gid(); 1910 opts->fs_fmask = opts->fs_dmask = current_umask(); 1911 opts->allow_utime = -1; 1912 opts->codepage = fat_default_codepage; 1913 fat_reset_iocharset(opts); 1914 if (is_vfat) { 1915 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1916 opts->rodir = 0; 1917 } else { 1918 opts->shortname = 0; 1919 opts->rodir = 1; 1920 } 1921 opts->name_check = 'n'; 1922 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1923 opts->unicode_xlate = 0; 1924 opts->numtail = 1; 1925 opts->usefree = opts->nocase = 0; 1926 opts->tz_set = 0; 1927 opts->nfs = 0; 1928 opts->errors = FAT_ERRORS_RO; 1929 opts->debug = 0; 1930 1931 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1932 1933 fc->fs_private = opts; 1934 /* fc->ops assigned by caller */ 1935 1936 return 0; 1937 } 1938 EXPORT_SYMBOL_GPL(fat_init_fs_context); 1939 1940 void fat_free_fc(struct fs_context *fc) 1941 { 1942 struct fat_mount_options *opts = fc->fs_private; 1943 1944 if (opts->iocharset != fat_default_iocharset) 1945 kfree(opts->iocharset); 1946 kfree(fc->fs_private); 1947 } 1948 EXPORT_SYMBOL_GPL(fat_free_fc); 1949 1950 static int __init init_fat_fs(void) 1951 { 1952 int err; 1953 1954 err = fat_cache_init(); 1955 if (err) 1956 return err; 1957 1958 err = fat_init_inodecache(); 1959 if (err) 1960 goto failed; 1961 1962 return 0; 1963 1964 failed: 1965 fat_cache_destroy(); 1966 return err; 1967 } 1968 1969 static void __exit exit_fat_fs(void) 1970 { 1971 fat_cache_destroy(); 1972 fat_destroy_inodecache(); 1973 } 1974 1975 module_init(init_fat_fs) 1976 module_exit(exit_fat_fs) 1977 1978 MODULE_DESCRIPTION("Core FAT filesystem support"); 1979 MODULE_LICENSE("GPL"); 1980