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