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