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/parser.h> 20 #include <linux/uio.h> 21 #include <linux/blkdev.h> 22 #include <linux/backing-dev.h> 23 #include <asm/unaligned.h> 24 #include <linux/random.h> 25 #include <linux/iversion.h> 26 #include "fat.h" 27 28 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 29 /* if user don't select VFAT, this is undefined. */ 30 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 31 #endif 32 33 #define KB_IN_SECTORS 2 34 35 /* DOS dates from 1980/1/1 through 2107/12/31 */ 36 #define FAT_DATE_MIN (0<<9 | 1<<5 | 1) 37 #define FAT_DATE_MAX (127<<9 | 12<<5 | 31) 38 #define FAT_TIME_MAX (23<<11 | 59<<5 | 29) 39 40 /* 41 * A deserialized copy of the on-disk structure laid out in struct 42 * fat_boot_sector. 43 */ 44 struct fat_bios_param_block { 45 u16 fat_sector_size; 46 u8 fat_sec_per_clus; 47 u16 fat_reserved; 48 u8 fat_fats; 49 u16 fat_dir_entries; 50 u16 fat_sectors; 51 u16 fat_fat_length; 52 u32 fat_total_sect; 53 54 u8 fat16_state; 55 u32 fat16_vol_id; 56 57 u32 fat32_length; 58 u32 fat32_root_cluster; 59 u16 fat32_info_sector; 60 u8 fat32_state; 61 u32 fat32_vol_id; 62 }; 63 64 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 65 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 66 67 static struct fat_floppy_defaults { 68 unsigned nr_sectors; 69 unsigned sec_per_clus; 70 unsigned dir_entries; 71 unsigned media; 72 unsigned fat_length; 73 } floppy_defaults[] = { 74 { 75 .nr_sectors = 160 * KB_IN_SECTORS, 76 .sec_per_clus = 1, 77 .dir_entries = 64, 78 .media = 0xFE, 79 .fat_length = 1, 80 }, 81 { 82 .nr_sectors = 180 * KB_IN_SECTORS, 83 .sec_per_clus = 1, 84 .dir_entries = 64, 85 .media = 0xFC, 86 .fat_length = 2, 87 }, 88 { 89 .nr_sectors = 320 * KB_IN_SECTORS, 90 .sec_per_clus = 2, 91 .dir_entries = 112, 92 .media = 0xFF, 93 .fat_length = 1, 94 }, 95 { 96 .nr_sectors = 360 * KB_IN_SECTORS, 97 .sec_per_clus = 2, 98 .dir_entries = 112, 99 .media = 0xFD, 100 .fat_length = 2, 101 }, 102 }; 103 104 int fat_add_cluster(struct inode *inode) 105 { 106 int err, cluster; 107 108 err = fat_alloc_clusters(inode, &cluster, 1); 109 if (err) 110 return err; 111 /* FIXME: this cluster should be added after data of this 112 * cluster is writed */ 113 err = fat_chain_add(inode, cluster, 1); 114 if (err) 115 fat_free_clusters(inode, cluster); 116 return err; 117 } 118 119 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 120 unsigned long *max_blocks, 121 struct buffer_head *bh_result, int create) 122 { 123 struct super_block *sb = inode->i_sb; 124 struct msdos_sb_info *sbi = MSDOS_SB(sb); 125 unsigned long mapped_blocks; 126 sector_t phys, last_block; 127 int err, offset; 128 129 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 130 if (err) 131 return err; 132 if (phys) { 133 map_bh(bh_result, sb, phys); 134 *max_blocks = min(mapped_blocks, *max_blocks); 135 return 0; 136 } 137 if (!create) 138 return 0; 139 140 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 141 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 142 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 143 return -EIO; 144 } 145 146 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); 147 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 148 /* 149 * allocate a cluster according to the following. 150 * 1) no more available blocks 151 * 2) not part of fallocate region 152 */ 153 if (!offset && !(iblock < last_block)) { 154 /* TODO: multiple cluster allocation would be desirable. */ 155 err = fat_add_cluster(inode); 156 if (err) 157 return err; 158 } 159 /* available blocks on this cluster */ 160 mapped_blocks = sbi->sec_per_clus - offset; 161 162 *max_blocks = min(mapped_blocks, *max_blocks); 163 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 164 165 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 166 if (err) 167 return err; 168 if (!phys) { 169 fat_fs_error(sb, 170 "invalid FAT chain (i_pos %lld, last_block %llu)", 171 MSDOS_I(inode)->i_pos, 172 (unsigned long long)last_block); 173 return -EIO; 174 } 175 176 BUG_ON(*max_blocks != mapped_blocks); 177 set_buffer_new(bh_result); 178 map_bh(bh_result, sb, phys); 179 180 return 0; 181 } 182 183 static int fat_get_block(struct inode *inode, sector_t iblock, 184 struct buffer_head *bh_result, int create) 185 { 186 struct super_block *sb = inode->i_sb; 187 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 188 int err; 189 190 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 191 if (err) 192 return err; 193 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 194 return 0; 195 } 196 197 static int fat_writepages(struct address_space *mapping, 198 struct writeback_control *wbc) 199 { 200 return mpage_writepages(mapping, wbc, fat_get_block); 201 } 202 203 static int fat_read_folio(struct file *file, struct folio *folio) 204 { 205 return mpage_read_folio(folio, fat_get_block); 206 } 207 208 static void fat_readahead(struct readahead_control *rac) 209 { 210 mpage_readahead(rac, fat_get_block); 211 } 212 213 static void fat_write_failed(struct address_space *mapping, loff_t to) 214 { 215 struct inode *inode = mapping->host; 216 217 if (to > inode->i_size) { 218 truncate_pagecache(inode, inode->i_size); 219 fat_truncate_blocks(inode, inode->i_size); 220 } 221 } 222 223 static int fat_write_begin(struct file *file, struct address_space *mapping, 224 loff_t pos, unsigned len, 225 struct page **pagep, void **fsdata) 226 { 227 int err; 228 229 *pagep = NULL; 230 err = cont_write_begin(file, mapping, pos, len, 231 pagep, fsdata, fat_get_block, 232 &MSDOS_I(mapping->host)->mmu_private); 233 if (err < 0) 234 fat_write_failed(mapping, pos + len); 235 return err; 236 } 237 238 static int fat_write_end(struct file *file, struct address_space *mapping, 239 loff_t pos, unsigned len, unsigned copied, 240 struct page *pagep, void *fsdata) 241 { 242 struct inode *inode = mapping->host; 243 int err; 244 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 245 if (err < len) 246 fat_write_failed(mapping, pos + len); 247 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 248 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 249 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 250 mark_inode_dirty(inode); 251 } 252 return err; 253 } 254 255 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 256 { 257 struct file *file = iocb->ki_filp; 258 struct address_space *mapping = file->f_mapping; 259 struct inode *inode = mapping->host; 260 size_t count = iov_iter_count(iter); 261 loff_t offset = iocb->ki_pos; 262 ssize_t ret; 263 264 if (iov_iter_rw(iter) == WRITE) { 265 /* 266 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 267 * so we need to update the ->mmu_private to block boundary. 268 * 269 * But we must fill the remaining area or hole by nul for 270 * updating ->mmu_private. 271 * 272 * Return 0, and fallback to normal buffered write. 273 */ 274 loff_t size = offset + count; 275 if (MSDOS_I(inode)->mmu_private < size) 276 return 0; 277 } 278 279 /* 280 * FAT need to use the DIO_LOCKING for avoiding the race 281 * condition of fat_get_block() and ->truncate(). 282 */ 283 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 284 if (ret < 0 && iov_iter_rw(iter) == WRITE) 285 fat_write_failed(mapping, offset + count); 286 287 return ret; 288 } 289 290 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 291 struct buffer_head *bh_result, int create) 292 { 293 struct super_block *sb = inode->i_sb; 294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 295 int err; 296 sector_t bmap; 297 unsigned long mapped_blocks; 298 299 BUG_ON(create != 0); 300 301 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 302 if (err) 303 return err; 304 305 if (bmap) { 306 map_bh(bh_result, sb, bmap); 307 max_blocks = min(mapped_blocks, max_blocks); 308 } 309 310 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 311 312 return 0; 313 } 314 315 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 316 { 317 sector_t blocknr; 318 319 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 320 down_read(&MSDOS_I(mapping->host)->truncate_lock); 321 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 322 up_read(&MSDOS_I(mapping->host)->truncate_lock); 323 324 return blocknr; 325 } 326 327 /* 328 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 329 * up to the end of the block which corresponds to `from'. 330 * This is required during truncate to physically zeroout the tail end 331 * of that block so it doesn't yield old data if the file is later grown. 332 * Also, avoid causing failure from fsx for cases of "data past EOF" 333 */ 334 int fat_block_truncate_page(struct inode *inode, loff_t from) 335 { 336 return block_truncate_page(inode->i_mapping, from, fat_get_block); 337 } 338 339 static const struct address_space_operations fat_aops = { 340 .dirty_folio = block_dirty_folio, 341 .invalidate_folio = block_invalidate_folio, 342 .read_folio = fat_read_folio, 343 .readahead = fat_readahead, 344 .writepages = fat_writepages, 345 .write_begin = fat_write_begin, 346 .write_end = fat_write_end, 347 .direct_IO = fat_direct_IO, 348 .bmap = _fat_bmap, 349 .migrate_folio = buffer_migrate_folio, 350 }; 351 352 /* 353 * New FAT inode stuff. We do the following: 354 * a) i_ino is constant and has nothing with on-disk location. 355 * b) FAT manages its own cache of directory entries. 356 * c) *This* cache is indexed by on-disk location. 357 * d) inode has an associated directory entry, all right, but 358 * it may be unhashed. 359 * e) currently entries are stored within struct inode. That should 360 * change. 361 * f) we deal with races in the following way: 362 * 1. readdir() and lookup() do FAT-dir-cache lookup. 363 * 2. rename() unhashes the F-d-c entry and rehashes it in 364 * a new place. 365 * 3. unlink() and rmdir() unhash F-d-c entry. 366 * 4. fat_write_inode() checks whether the thing is unhashed. 367 * If it is we silently return. If it isn't we do bread(), 368 * check if the location is still valid and retry if it 369 * isn't. Otherwise we do changes. 370 * 5. Spinlock is used to protect hash/unhash/location check/lookup 371 * 6. fat_evict_inode() unhashes the F-d-c entry. 372 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 373 * and consider negative result as cache miss. 374 */ 375 376 static void fat_hash_init(struct super_block *sb) 377 { 378 struct msdos_sb_info *sbi = MSDOS_SB(sb); 379 int i; 380 381 spin_lock_init(&sbi->inode_hash_lock); 382 for (i = 0; i < FAT_HASH_SIZE; i++) 383 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 384 } 385 386 static inline unsigned long fat_hash(loff_t i_pos) 387 { 388 return hash_32(i_pos, FAT_HASH_BITS); 389 } 390 391 static void dir_hash_init(struct super_block *sb) 392 { 393 struct msdos_sb_info *sbi = MSDOS_SB(sb); 394 int i; 395 396 spin_lock_init(&sbi->dir_hash_lock); 397 for (i = 0; i < FAT_HASH_SIZE; i++) 398 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 399 } 400 401 void fat_attach(struct inode *inode, loff_t i_pos) 402 { 403 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 404 405 if (inode->i_ino != MSDOS_ROOT_INO) { 406 struct hlist_head *head = sbi->inode_hashtable 407 + fat_hash(i_pos); 408 409 spin_lock(&sbi->inode_hash_lock); 410 MSDOS_I(inode)->i_pos = i_pos; 411 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 412 spin_unlock(&sbi->inode_hash_lock); 413 } 414 415 /* If NFS support is enabled, cache the mapping of start cluster 416 * to directory inode. This is used during reconnection of 417 * dentries to the filesystem root. 418 */ 419 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 420 struct hlist_head *d_head = sbi->dir_hashtable; 421 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 422 423 spin_lock(&sbi->dir_hash_lock); 424 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 425 spin_unlock(&sbi->dir_hash_lock); 426 } 427 } 428 EXPORT_SYMBOL_GPL(fat_attach); 429 430 void fat_detach(struct inode *inode) 431 { 432 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 433 spin_lock(&sbi->inode_hash_lock); 434 MSDOS_I(inode)->i_pos = 0; 435 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 436 spin_unlock(&sbi->inode_hash_lock); 437 438 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 439 spin_lock(&sbi->dir_hash_lock); 440 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 441 spin_unlock(&sbi->dir_hash_lock); 442 } 443 } 444 EXPORT_SYMBOL_GPL(fat_detach); 445 446 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 447 { 448 struct msdos_sb_info *sbi = MSDOS_SB(sb); 449 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 450 struct msdos_inode_info *i; 451 struct inode *inode = NULL; 452 453 spin_lock(&sbi->inode_hash_lock); 454 hlist_for_each_entry(i, head, i_fat_hash) { 455 BUG_ON(i->vfs_inode.i_sb != sb); 456 if (i->i_pos != i_pos) 457 continue; 458 inode = igrab(&i->vfs_inode); 459 if (inode) 460 break; 461 } 462 spin_unlock(&sbi->inode_hash_lock); 463 return inode; 464 } 465 466 static int is_exec(unsigned char *extension) 467 { 468 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 469 470 for (walk = exe_extensions; *walk; walk += 3) 471 if (!strncmp(extension, walk, 3)) 472 return 1; 473 return 0; 474 } 475 476 static int fat_calc_dir_size(struct inode *inode) 477 { 478 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 479 int ret, fclus, dclus; 480 481 inode->i_size = 0; 482 if (MSDOS_I(inode)->i_start == 0) 483 return 0; 484 485 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 486 if (ret < 0) 487 return ret; 488 inode->i_size = (fclus + 1) << sbi->cluster_bits; 489 490 return 0; 491 } 492 493 static int fat_validate_dir(struct inode *dir) 494 { 495 struct super_block *sb = dir->i_sb; 496 497 if (dir->i_nlink < 2) { 498 /* Directory should have "."/".." entries at least. */ 499 fat_fs_error(sb, "corrupted directory (invalid entries)"); 500 return -EIO; 501 } 502 if (MSDOS_I(dir)->i_start == 0 || 503 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 504 /* Directory should point valid cluster. */ 505 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 506 return -EIO; 507 } 508 return 0; 509 } 510 511 /* doesn't deal with root inode */ 512 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 513 { 514 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 515 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, &inode->i_mtime, de->time, de->date, 0); 565 inode_set_ctime_to_ts(inode, inode->i_mtime); 566 if (sbi->options.isvfat) { 567 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 568 fat_time_fat2unix(sbi, &MSDOS_I(inode)->i_crtime, de->ctime, 569 de->cdate, de->ctime_cs); 570 } else 571 inode->i_atime = fat_truncate_atime(sbi, &inode->i_mtime); 572 573 return 0; 574 } 575 576 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 577 { 578 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 579 mutex_lock(&sbi->nfs_build_inode_lock); 580 } 581 582 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 583 { 584 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 585 mutex_unlock(&sbi->nfs_build_inode_lock); 586 } 587 588 struct inode *fat_build_inode(struct super_block *sb, 589 struct msdos_dir_entry *de, loff_t i_pos) 590 { 591 struct inode *inode; 592 int err; 593 594 fat_lock_build_inode(MSDOS_SB(sb)); 595 inode = fat_iget(sb, i_pos); 596 if (inode) 597 goto out; 598 inode = new_inode(sb); 599 if (!inode) { 600 inode = ERR_PTR(-ENOMEM); 601 goto out; 602 } 603 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 604 inode_set_iversion(inode, 1); 605 err = fat_fill_inode(inode, de); 606 if (err) { 607 iput(inode); 608 inode = ERR_PTR(err); 609 goto out; 610 } 611 fat_attach(inode, i_pos); 612 insert_inode_hash(inode); 613 out: 614 fat_unlock_build_inode(MSDOS_SB(sb)); 615 return inode; 616 } 617 618 EXPORT_SYMBOL_GPL(fat_build_inode); 619 620 static int __fat_write_inode(struct inode *inode, int wait); 621 622 static void fat_free_eofblocks(struct inode *inode) 623 { 624 /* Release unwritten fallocated blocks on inode eviction. */ 625 if ((inode->i_blocks << 9) > 626 round_up(MSDOS_I(inode)->mmu_private, 627 MSDOS_SB(inode->i_sb)->cluster_size)) { 628 int err; 629 630 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 631 /* Fallocate results in updating the i_start/iogstart 632 * for the zero byte file. So, make it return to 633 * original state during evict and commit it to avoid 634 * any corruption on the next access to the cluster 635 * chain for the file. 636 */ 637 err = __fat_write_inode(inode, inode_needs_sync(inode)); 638 if (err) { 639 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 640 "update on disk inode for unused " 641 "fallocated blocks, inode could be " 642 "corrupted. Please run fsck"); 643 } 644 645 } 646 } 647 648 static void fat_evict_inode(struct inode *inode) 649 { 650 truncate_inode_pages_final(&inode->i_data); 651 if (!inode->i_nlink) { 652 inode->i_size = 0; 653 fat_truncate_blocks(inode, 0); 654 } else 655 fat_free_eofblocks(inode); 656 657 invalidate_inode_buffers(inode); 658 clear_inode(inode); 659 fat_cache_inval_inode(inode); 660 fat_detach(inode); 661 } 662 663 static void fat_set_state(struct super_block *sb, 664 unsigned int set, unsigned int force) 665 { 666 struct buffer_head *bh; 667 struct fat_boot_sector *b; 668 struct msdos_sb_info *sbi = MSDOS_SB(sb); 669 670 /* do not change any thing if mounted read only */ 671 if (sb_rdonly(sb) && !force) 672 return; 673 674 /* do not change state if fs was dirty */ 675 if (sbi->dirty) { 676 /* warn only on set (mount). */ 677 if (set) 678 fat_msg(sb, KERN_WARNING, "Volume was not properly " 679 "unmounted. Some data may be corrupt. " 680 "Please run fsck."); 681 return; 682 } 683 684 bh = sb_bread(sb, 0); 685 if (bh == NULL) { 686 fat_msg(sb, KERN_ERR, "unable to read boot sector " 687 "to mark fs as dirty"); 688 return; 689 } 690 691 b = (struct fat_boot_sector *) bh->b_data; 692 693 if (is_fat32(sbi)) { 694 if (set) 695 b->fat32.state |= FAT_STATE_DIRTY; 696 else 697 b->fat32.state &= ~FAT_STATE_DIRTY; 698 } else /* fat 16 and 12 */ { 699 if (set) 700 b->fat16.state |= FAT_STATE_DIRTY; 701 else 702 b->fat16.state &= ~FAT_STATE_DIRTY; 703 } 704 705 mark_buffer_dirty(bh); 706 sync_dirty_buffer(bh); 707 brelse(bh); 708 } 709 710 static void fat_reset_iocharset(struct fat_mount_options *opts) 711 { 712 if (opts->iocharset != fat_default_iocharset) { 713 /* Note: opts->iocharset can be NULL here */ 714 kfree(opts->iocharset); 715 opts->iocharset = fat_default_iocharset; 716 } 717 } 718 719 static void delayed_free(struct rcu_head *p) 720 { 721 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 722 unload_nls(sbi->nls_disk); 723 unload_nls(sbi->nls_io); 724 fat_reset_iocharset(&sbi->options); 725 kfree(sbi); 726 } 727 728 static void fat_put_super(struct super_block *sb) 729 { 730 struct msdos_sb_info *sbi = MSDOS_SB(sb); 731 732 fat_set_state(sb, 0, 0); 733 734 iput(sbi->fsinfo_inode); 735 iput(sbi->fat_inode); 736 737 call_rcu(&sbi->rcu, delayed_free); 738 } 739 740 static struct kmem_cache *fat_inode_cachep; 741 742 static struct inode *fat_alloc_inode(struct super_block *sb) 743 { 744 struct msdos_inode_info *ei; 745 ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS); 746 if (!ei) 747 return NULL; 748 749 init_rwsem(&ei->truncate_lock); 750 /* Zeroing to allow iput() even if partial initialized inode. */ 751 ei->mmu_private = 0; 752 ei->i_start = 0; 753 ei->i_logstart = 0; 754 ei->i_attrs = 0; 755 ei->i_pos = 0; 756 ei->i_crtime.tv_sec = 0; 757 ei->i_crtime.tv_nsec = 0; 758 759 return &ei->vfs_inode; 760 } 761 762 static void fat_free_inode(struct inode *inode) 763 { 764 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 765 } 766 767 static void init_once(void *foo) 768 { 769 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 770 771 spin_lock_init(&ei->cache_lru_lock); 772 ei->nr_caches = 0; 773 ei->cache_valid_id = FAT_CACHE_VALID + 1; 774 INIT_LIST_HEAD(&ei->cache_lru); 775 INIT_HLIST_NODE(&ei->i_fat_hash); 776 INIT_HLIST_NODE(&ei->i_dir_hash); 777 inode_init_once(&ei->vfs_inode); 778 } 779 780 static int __init fat_init_inodecache(void) 781 { 782 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 783 sizeof(struct msdos_inode_info), 784 0, (SLAB_RECLAIM_ACCOUNT| 785 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 786 init_once); 787 if (fat_inode_cachep == NULL) 788 return -ENOMEM; 789 return 0; 790 } 791 792 static void __exit fat_destroy_inodecache(void) 793 { 794 /* 795 * Make sure all delayed rcu free inodes are flushed before we 796 * destroy cache. 797 */ 798 rcu_barrier(); 799 kmem_cache_destroy(fat_inode_cachep); 800 } 801 802 static int fat_remount(struct super_block *sb, int *flags, char *data) 803 { 804 bool new_rdonly; 805 struct msdos_sb_info *sbi = MSDOS_SB(sb); 806 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 807 808 sync_filesystem(sb); 809 810 /* make sure we update state on remount. */ 811 new_rdonly = *flags & SB_RDONLY; 812 if (new_rdonly != sb_rdonly(sb)) { 813 if (new_rdonly) 814 fat_set_state(sb, 0, 0); 815 else 816 fat_set_state(sb, 1, 1); 817 } 818 return 0; 819 } 820 821 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 822 { 823 struct super_block *sb = dentry->d_sb; 824 struct msdos_sb_info *sbi = MSDOS_SB(sb); 825 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 826 827 /* If the count of free cluster is still unknown, counts it here. */ 828 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 829 int err = fat_count_free_clusters(dentry->d_sb); 830 if (err) 831 return err; 832 } 833 834 buf->f_type = dentry->d_sb->s_magic; 835 buf->f_bsize = sbi->cluster_size; 836 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 837 buf->f_bfree = sbi->free_clusters; 838 buf->f_bavail = sbi->free_clusters; 839 buf->f_fsid = u64_to_fsid(id); 840 buf->f_namelen = 841 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 842 843 return 0; 844 } 845 846 static int __fat_write_inode(struct inode *inode, int wait) 847 { 848 struct super_block *sb = inode->i_sb; 849 struct msdos_sb_info *sbi = MSDOS_SB(sb); 850 struct buffer_head *bh; 851 struct msdos_dir_entry *raw_entry; 852 loff_t i_pos; 853 sector_t blocknr; 854 int err, offset; 855 856 if (inode->i_ino == MSDOS_ROOT_INO) 857 return 0; 858 859 retry: 860 i_pos = fat_i_pos_read(sbi, inode); 861 if (!i_pos) 862 return 0; 863 864 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 865 bh = sb_bread(sb, blocknr); 866 if (!bh) { 867 fat_msg(sb, KERN_ERR, "unable to read inode block " 868 "for updating (i_pos %lld)", i_pos); 869 return -EIO; 870 } 871 spin_lock(&sbi->inode_hash_lock); 872 if (i_pos != MSDOS_I(inode)->i_pos) { 873 spin_unlock(&sbi->inode_hash_lock); 874 brelse(bh); 875 goto retry; 876 } 877 878 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 879 if (S_ISDIR(inode->i_mode)) 880 raw_entry->size = 0; 881 else 882 raw_entry->size = cpu_to_le32(inode->i_size); 883 raw_entry->attr = fat_make_attrs(inode); 884 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 885 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 886 &raw_entry->date, NULL); 887 if (sbi->options.isvfat) { 888 __le16 atime; 889 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 890 &raw_entry->adate, NULL); 891 fat_time_unix2fat(sbi, &MSDOS_I(inode)->i_crtime, &raw_entry->ctime, 892 &raw_entry->cdate, &raw_entry->ctime_cs); 893 } 894 spin_unlock(&sbi->inode_hash_lock); 895 mark_buffer_dirty(bh); 896 err = 0; 897 if (wait) 898 err = sync_dirty_buffer(bh); 899 brelse(bh); 900 return err; 901 } 902 903 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 904 { 905 int err; 906 907 if (inode->i_ino == MSDOS_FSINFO_INO) { 908 struct super_block *sb = inode->i_sb; 909 910 mutex_lock(&MSDOS_SB(sb)->s_lock); 911 err = fat_clusters_flush(sb); 912 mutex_unlock(&MSDOS_SB(sb)->s_lock); 913 } else 914 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 915 916 return err; 917 } 918 919 int fat_sync_inode(struct inode *inode) 920 { 921 return __fat_write_inode(inode, 1); 922 } 923 924 EXPORT_SYMBOL_GPL(fat_sync_inode); 925 926 static int fat_show_options(struct seq_file *m, struct dentry *root); 927 static const struct super_operations fat_sops = { 928 .alloc_inode = fat_alloc_inode, 929 .free_inode = fat_free_inode, 930 .write_inode = fat_write_inode, 931 .evict_inode = fat_evict_inode, 932 .put_super = fat_put_super, 933 .statfs = fat_statfs, 934 .remount_fs = fat_remount, 935 936 .show_options = fat_show_options, 937 }; 938 939 static int fat_show_options(struct seq_file *m, struct dentry *root) 940 { 941 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 942 struct fat_mount_options *opts = &sbi->options; 943 int isvfat = opts->isvfat; 944 945 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 946 seq_printf(m, ",uid=%u", 947 from_kuid_munged(&init_user_ns, opts->fs_uid)); 948 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 949 seq_printf(m, ",gid=%u", 950 from_kgid_munged(&init_user_ns, opts->fs_gid)); 951 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 952 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 953 if (opts->allow_utime) 954 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 955 if (sbi->nls_disk) 956 /* strip "cp" prefix from displayed option */ 957 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 958 if (isvfat) { 959 if (sbi->nls_io) 960 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 961 962 switch (opts->shortname) { 963 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 964 seq_puts(m, ",shortname=win95"); 965 break; 966 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 967 seq_puts(m, ",shortname=winnt"); 968 break; 969 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 970 seq_puts(m, ",shortname=mixed"); 971 break; 972 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 973 seq_puts(m, ",shortname=lower"); 974 break; 975 default: 976 seq_puts(m, ",shortname=unknown"); 977 break; 978 } 979 } 980 if (opts->name_check != 'n') 981 seq_printf(m, ",check=%c", opts->name_check); 982 if (opts->usefree) 983 seq_puts(m, ",usefree"); 984 if (opts->quiet) 985 seq_puts(m, ",quiet"); 986 if (opts->showexec) 987 seq_puts(m, ",showexec"); 988 if (opts->sys_immutable) 989 seq_puts(m, ",sys_immutable"); 990 if (!isvfat) { 991 if (opts->dotsOK) 992 seq_puts(m, ",dotsOK=yes"); 993 if (opts->nocase) 994 seq_puts(m, ",nocase"); 995 } else { 996 if (opts->utf8) 997 seq_puts(m, ",utf8"); 998 if (opts->unicode_xlate) 999 seq_puts(m, ",uni_xlate"); 1000 if (!opts->numtail) 1001 seq_puts(m, ",nonumtail"); 1002 if (opts->rodir) 1003 seq_puts(m, ",rodir"); 1004 } 1005 if (opts->flush) 1006 seq_puts(m, ",flush"); 1007 if (opts->tz_set) { 1008 if (opts->time_offset) 1009 seq_printf(m, ",time_offset=%d", opts->time_offset); 1010 else 1011 seq_puts(m, ",tz=UTC"); 1012 } 1013 if (opts->errors == FAT_ERRORS_CONT) 1014 seq_puts(m, ",errors=continue"); 1015 else if (opts->errors == FAT_ERRORS_PANIC) 1016 seq_puts(m, ",errors=panic"); 1017 else 1018 seq_puts(m, ",errors=remount-ro"); 1019 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1020 seq_puts(m, ",nfs=nostale_ro"); 1021 else if (opts->nfs) 1022 seq_puts(m, ",nfs=stale_rw"); 1023 if (opts->discard) 1024 seq_puts(m, ",discard"); 1025 if (opts->dos1xfloppy) 1026 seq_puts(m, ",dos1xfloppy"); 1027 1028 return 0; 1029 } 1030 1031 enum { 1032 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1033 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1034 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1035 Opt_immutable, Opt_dots, Opt_nodots, 1036 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1037 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1038 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1039 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1040 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1041 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1042 }; 1043 1044 static const match_table_t fat_tokens = { 1045 {Opt_check_r, "check=relaxed"}, 1046 {Opt_check_s, "check=strict"}, 1047 {Opt_check_n, "check=normal"}, 1048 {Opt_check_r, "check=r"}, 1049 {Opt_check_s, "check=s"}, 1050 {Opt_check_n, "check=n"}, 1051 {Opt_uid, "uid=%u"}, 1052 {Opt_gid, "gid=%u"}, 1053 {Opt_umask, "umask=%o"}, 1054 {Opt_dmask, "dmask=%o"}, 1055 {Opt_fmask, "fmask=%o"}, 1056 {Opt_allow_utime, "allow_utime=%o"}, 1057 {Opt_codepage, "codepage=%u"}, 1058 {Opt_usefree, "usefree"}, 1059 {Opt_nocase, "nocase"}, 1060 {Opt_quiet, "quiet"}, 1061 {Opt_showexec, "showexec"}, 1062 {Opt_debug, "debug"}, 1063 {Opt_immutable, "sys_immutable"}, 1064 {Opt_flush, "flush"}, 1065 {Opt_tz_utc, "tz=UTC"}, 1066 {Opt_time_offset, "time_offset=%d"}, 1067 {Opt_err_cont, "errors=continue"}, 1068 {Opt_err_panic, "errors=panic"}, 1069 {Opt_err_ro, "errors=remount-ro"}, 1070 {Opt_discard, "discard"}, 1071 {Opt_nfs_stale_rw, "nfs"}, 1072 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1073 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1074 {Opt_dos1xfloppy, "dos1xfloppy"}, 1075 {Opt_obsolete, "conv=binary"}, 1076 {Opt_obsolete, "conv=text"}, 1077 {Opt_obsolete, "conv=auto"}, 1078 {Opt_obsolete, "conv=b"}, 1079 {Opt_obsolete, "conv=t"}, 1080 {Opt_obsolete, "conv=a"}, 1081 {Opt_obsolete, "fat=%u"}, 1082 {Opt_obsolete, "blocksize=%u"}, 1083 {Opt_obsolete, "cvf_format=%20s"}, 1084 {Opt_obsolete, "cvf_options=%100s"}, 1085 {Opt_obsolete, "posix"}, 1086 {Opt_err, NULL}, 1087 }; 1088 static const match_table_t msdos_tokens = { 1089 {Opt_nodots, "nodots"}, 1090 {Opt_nodots, "dotsOK=no"}, 1091 {Opt_dots, "dots"}, 1092 {Opt_dots, "dotsOK=yes"}, 1093 {Opt_err, NULL} 1094 }; 1095 static const match_table_t vfat_tokens = { 1096 {Opt_charset, "iocharset=%s"}, 1097 {Opt_shortname_lower, "shortname=lower"}, 1098 {Opt_shortname_win95, "shortname=win95"}, 1099 {Opt_shortname_winnt, "shortname=winnt"}, 1100 {Opt_shortname_mixed, "shortname=mixed"}, 1101 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1102 {Opt_utf8_no, "utf8=no"}, 1103 {Opt_utf8_no, "utf8=false"}, 1104 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1105 {Opt_utf8_yes, "utf8=yes"}, 1106 {Opt_utf8_yes, "utf8=true"}, 1107 {Opt_utf8_yes, "utf8"}, 1108 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1109 {Opt_uni_xl_no, "uni_xlate=no"}, 1110 {Opt_uni_xl_no, "uni_xlate=false"}, 1111 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1112 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1113 {Opt_uni_xl_yes, "uni_xlate=true"}, 1114 {Opt_uni_xl_yes, "uni_xlate"}, 1115 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1116 {Opt_nonumtail_no, "nonumtail=no"}, 1117 {Opt_nonumtail_no, "nonumtail=false"}, 1118 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1119 {Opt_nonumtail_yes, "nonumtail=yes"}, 1120 {Opt_nonumtail_yes, "nonumtail=true"}, 1121 {Opt_nonumtail_yes, "nonumtail"}, 1122 {Opt_rodir, "rodir"}, 1123 {Opt_err, NULL} 1124 }; 1125 1126 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1127 int silent, int *debug, struct fat_mount_options *opts) 1128 { 1129 char *p; 1130 substring_t args[MAX_OPT_ARGS]; 1131 int option; 1132 char *iocharset; 1133 1134 opts->isvfat = is_vfat; 1135 1136 opts->fs_uid = current_uid(); 1137 opts->fs_gid = current_gid(); 1138 opts->fs_fmask = opts->fs_dmask = current_umask(); 1139 opts->allow_utime = -1; 1140 opts->codepage = fat_default_codepage; 1141 fat_reset_iocharset(opts); 1142 if (is_vfat) { 1143 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1144 opts->rodir = 0; 1145 } else { 1146 opts->shortname = 0; 1147 opts->rodir = 1; 1148 } 1149 opts->name_check = 'n'; 1150 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1151 opts->unicode_xlate = 0; 1152 opts->numtail = 1; 1153 opts->usefree = opts->nocase = 0; 1154 opts->tz_set = 0; 1155 opts->nfs = 0; 1156 opts->errors = FAT_ERRORS_RO; 1157 *debug = 0; 1158 1159 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1160 1161 if (!options) 1162 goto out; 1163 1164 while ((p = strsep(&options, ",")) != NULL) { 1165 int token; 1166 if (!*p) 1167 continue; 1168 1169 token = match_token(p, fat_tokens, args); 1170 if (token == Opt_err) { 1171 if (is_vfat) 1172 token = match_token(p, vfat_tokens, args); 1173 else 1174 token = match_token(p, msdos_tokens, args); 1175 } 1176 switch (token) { 1177 case Opt_check_s: 1178 opts->name_check = 's'; 1179 break; 1180 case Opt_check_r: 1181 opts->name_check = 'r'; 1182 break; 1183 case Opt_check_n: 1184 opts->name_check = 'n'; 1185 break; 1186 case Opt_usefree: 1187 opts->usefree = 1; 1188 break; 1189 case Opt_nocase: 1190 if (!is_vfat) 1191 opts->nocase = 1; 1192 else { 1193 /* for backward compatibility */ 1194 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1195 | VFAT_SFN_CREATE_WIN95; 1196 } 1197 break; 1198 case Opt_quiet: 1199 opts->quiet = 1; 1200 break; 1201 case Opt_showexec: 1202 opts->showexec = 1; 1203 break; 1204 case Opt_debug: 1205 *debug = 1; 1206 break; 1207 case Opt_immutable: 1208 opts->sys_immutable = 1; 1209 break; 1210 case Opt_uid: 1211 if (match_int(&args[0], &option)) 1212 return -EINVAL; 1213 opts->fs_uid = make_kuid(current_user_ns(), option); 1214 if (!uid_valid(opts->fs_uid)) 1215 return -EINVAL; 1216 break; 1217 case Opt_gid: 1218 if (match_int(&args[0], &option)) 1219 return -EINVAL; 1220 opts->fs_gid = make_kgid(current_user_ns(), option); 1221 if (!gid_valid(opts->fs_gid)) 1222 return -EINVAL; 1223 break; 1224 case Opt_umask: 1225 if (match_octal(&args[0], &option)) 1226 return -EINVAL; 1227 opts->fs_fmask = opts->fs_dmask = option; 1228 break; 1229 case Opt_dmask: 1230 if (match_octal(&args[0], &option)) 1231 return -EINVAL; 1232 opts->fs_dmask = option; 1233 break; 1234 case Opt_fmask: 1235 if (match_octal(&args[0], &option)) 1236 return -EINVAL; 1237 opts->fs_fmask = option; 1238 break; 1239 case Opt_allow_utime: 1240 if (match_octal(&args[0], &option)) 1241 return -EINVAL; 1242 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1243 break; 1244 case Opt_codepage: 1245 if (match_int(&args[0], &option)) 1246 return -EINVAL; 1247 opts->codepage = option; 1248 break; 1249 case Opt_flush: 1250 opts->flush = 1; 1251 break; 1252 case Opt_time_offset: 1253 if (match_int(&args[0], &option)) 1254 return -EINVAL; 1255 /* 1256 * GMT+-12 zones may have DST corrections so at least 1257 * 13 hours difference is needed. Make the limit 24 1258 * just in case someone invents something unusual. 1259 */ 1260 if (option < -24 * 60 || option > 24 * 60) 1261 return -EINVAL; 1262 opts->tz_set = 1; 1263 opts->time_offset = option; 1264 break; 1265 case Opt_tz_utc: 1266 opts->tz_set = 1; 1267 opts->time_offset = 0; 1268 break; 1269 case Opt_err_cont: 1270 opts->errors = FAT_ERRORS_CONT; 1271 break; 1272 case Opt_err_panic: 1273 opts->errors = FAT_ERRORS_PANIC; 1274 break; 1275 case Opt_err_ro: 1276 opts->errors = FAT_ERRORS_RO; 1277 break; 1278 case Opt_nfs_stale_rw: 1279 opts->nfs = FAT_NFS_STALE_RW; 1280 break; 1281 case Opt_nfs_nostale_ro: 1282 opts->nfs = FAT_NFS_NOSTALE_RO; 1283 break; 1284 case Opt_dos1xfloppy: 1285 opts->dos1xfloppy = 1; 1286 break; 1287 1288 /* msdos specific */ 1289 case Opt_dots: 1290 opts->dotsOK = 1; 1291 break; 1292 case Opt_nodots: 1293 opts->dotsOK = 0; 1294 break; 1295 1296 /* vfat specific */ 1297 case Opt_charset: 1298 fat_reset_iocharset(opts); 1299 iocharset = match_strdup(&args[0]); 1300 if (!iocharset) 1301 return -ENOMEM; 1302 opts->iocharset = iocharset; 1303 break; 1304 case Opt_shortname_lower: 1305 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1306 | VFAT_SFN_CREATE_WIN95; 1307 break; 1308 case Opt_shortname_win95: 1309 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1310 | VFAT_SFN_CREATE_WIN95; 1311 break; 1312 case Opt_shortname_winnt: 1313 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1314 | VFAT_SFN_CREATE_WINNT; 1315 break; 1316 case Opt_shortname_mixed: 1317 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1318 | VFAT_SFN_CREATE_WIN95; 1319 break; 1320 case Opt_utf8_no: /* 0 or no or false */ 1321 opts->utf8 = 0; 1322 break; 1323 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1324 opts->utf8 = 1; 1325 break; 1326 case Opt_uni_xl_no: /* 0 or no or false */ 1327 opts->unicode_xlate = 0; 1328 break; 1329 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1330 opts->unicode_xlate = 1; 1331 break; 1332 case Opt_nonumtail_no: /* 0 or no or false */ 1333 opts->numtail = 1; /* negated option */ 1334 break; 1335 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1336 opts->numtail = 0; /* negated option */ 1337 break; 1338 case Opt_rodir: 1339 opts->rodir = 1; 1340 break; 1341 case Opt_discard: 1342 opts->discard = 1; 1343 break; 1344 1345 /* obsolete mount options */ 1346 case Opt_obsolete: 1347 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1348 "not supported now", p); 1349 break; 1350 /* unknown option */ 1351 default: 1352 if (!silent) { 1353 fat_msg(sb, KERN_ERR, 1354 "Unrecognized mount option \"%s\" " 1355 "or missing value", p); 1356 } 1357 return -EINVAL; 1358 } 1359 } 1360 1361 out: 1362 /* UTF-8 doesn't provide FAT semantics */ 1363 if (!strcmp(opts->iocharset, "utf8")) { 1364 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1365 " for FAT filesystems, filesystem will be " 1366 "case sensitive!"); 1367 } 1368 1369 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1370 if (opts->allow_utime == (unsigned short)-1) 1371 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1372 if (opts->unicode_xlate) 1373 opts->utf8 = 0; 1374 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1375 sb->s_flags |= SB_RDONLY; 1376 sb->s_export_op = &fat_export_ops_nostale; 1377 } 1378 1379 return 0; 1380 } 1381 1382 static int fat_read_root(struct inode *inode) 1383 { 1384 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1385 int error; 1386 1387 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1388 inode->i_uid = sbi->options.fs_uid; 1389 inode->i_gid = sbi->options.fs_gid; 1390 inode_inc_iversion(inode); 1391 inode->i_generation = 0; 1392 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1393 inode->i_op = sbi->dir_ops; 1394 inode->i_fop = &fat_dir_operations; 1395 if (is_fat32(sbi)) { 1396 MSDOS_I(inode)->i_start = sbi->root_cluster; 1397 error = fat_calc_dir_size(inode); 1398 if (error < 0) 1399 return error; 1400 } else { 1401 MSDOS_I(inode)->i_start = 0; 1402 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1403 } 1404 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1405 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1406 MSDOS_I(inode)->i_logstart = 0; 1407 MSDOS_I(inode)->mmu_private = inode->i_size; 1408 1409 fat_save_attrs(inode, ATTR_DIR); 1410 inode->i_mtime = inode->i_atime = inode_set_ctime(inode, 0, 0); 1411 set_nlink(inode, fat_subdirs(inode)+2); 1412 1413 return 0; 1414 } 1415 1416 static unsigned long calc_fat_clusters(struct super_block *sb) 1417 { 1418 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1419 1420 /* Divide first to avoid overflow */ 1421 if (!is_fat12(sbi)) { 1422 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1423 return ent_per_sec * sbi->fat_length; 1424 } 1425 1426 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1427 } 1428 1429 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1430 { 1431 if (get_unaligned_le16(&b->sector_size)) 1432 return false; 1433 if (b->sec_per_clus) 1434 return false; 1435 if (b->reserved) 1436 return false; 1437 if (b->fats) 1438 return false; 1439 if (get_unaligned_le16(&b->dir_entries)) 1440 return false; 1441 if (get_unaligned_le16(&b->sectors)) 1442 return false; 1443 if (b->media) 1444 return false; 1445 if (b->fat_length) 1446 return false; 1447 if (b->secs_track) 1448 return false; 1449 if (b->heads) 1450 return false; 1451 return true; 1452 } 1453 1454 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1455 int silent, struct fat_bios_param_block *bpb) 1456 { 1457 int error = -EINVAL; 1458 1459 /* Read in BPB ... */ 1460 memset(bpb, 0, sizeof(*bpb)); 1461 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1462 bpb->fat_sec_per_clus = b->sec_per_clus; 1463 bpb->fat_reserved = le16_to_cpu(b->reserved); 1464 bpb->fat_fats = b->fats; 1465 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1466 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1467 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1468 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1469 1470 bpb->fat16_state = b->fat16.state; 1471 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1472 1473 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1474 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1475 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1476 bpb->fat32_state = b->fat32.state; 1477 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1478 1479 /* Validate this looks like a FAT filesystem BPB */ 1480 if (!bpb->fat_reserved) { 1481 if (!silent) 1482 fat_msg(sb, KERN_ERR, 1483 "bogus number of reserved sectors"); 1484 goto out; 1485 } 1486 if (!bpb->fat_fats) { 1487 if (!silent) 1488 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1489 goto out; 1490 } 1491 1492 /* 1493 * Earlier we checked here that b->secs_track and b->head are nonzero, 1494 * but it turns out valid FAT filesystems can have zero there. 1495 */ 1496 1497 if (!fat_valid_media(b->media)) { 1498 if (!silent) 1499 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1500 (unsigned)b->media); 1501 goto out; 1502 } 1503 1504 if (!is_power_of_2(bpb->fat_sector_size) 1505 || (bpb->fat_sector_size < 512) 1506 || (bpb->fat_sector_size > 4096)) { 1507 if (!silent) 1508 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1509 (unsigned)bpb->fat_sector_size); 1510 goto out; 1511 } 1512 1513 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1514 if (!silent) 1515 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1516 (unsigned)bpb->fat_sec_per_clus); 1517 goto out; 1518 } 1519 1520 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1521 if (!silent) 1522 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1523 goto out; 1524 } 1525 1526 error = 0; 1527 1528 out: 1529 return error; 1530 } 1531 1532 static int fat_read_static_bpb(struct super_block *sb, 1533 struct fat_boot_sector *b, int silent, 1534 struct fat_bios_param_block *bpb) 1535 { 1536 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1537 sector_t bd_sects = bdev_nr_sectors(sb->s_bdev); 1538 struct fat_floppy_defaults *fdefaults = NULL; 1539 int error = -EINVAL; 1540 unsigned i; 1541 1542 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1543 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1544 if (!silent) 1545 fat_msg(sb, KERN_ERR, 1546 "%s; no bootstrapping code", notdos1x); 1547 goto out; 1548 } 1549 1550 /* 1551 * If any value in this region is non-zero, it isn't archaic 1552 * DOS. 1553 */ 1554 if (!fat_bpb_is_zero(b)) { 1555 if (!silent) 1556 fat_msg(sb, KERN_ERR, 1557 "%s; DOS 2.x BPB is non-zero", notdos1x); 1558 goto out; 1559 } 1560 1561 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1562 if (floppy_defaults[i].nr_sectors == bd_sects) { 1563 fdefaults = &floppy_defaults[i]; 1564 break; 1565 } 1566 } 1567 1568 if (fdefaults == NULL) { 1569 if (!silent) 1570 fat_msg(sb, KERN_WARNING, 1571 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1572 (u64)bd_sects); 1573 goto out; 1574 } 1575 1576 if (!silent) 1577 fat_msg(sb, KERN_INFO, 1578 "This looks like a DOS 1.x volume; assuming default BPB values"); 1579 1580 memset(bpb, 0, sizeof(*bpb)); 1581 bpb->fat_sector_size = SECTOR_SIZE; 1582 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1583 bpb->fat_reserved = 1; 1584 bpb->fat_fats = 2; 1585 bpb->fat_dir_entries = fdefaults->dir_entries; 1586 bpb->fat_sectors = fdefaults->nr_sectors; 1587 bpb->fat_fat_length = fdefaults->fat_length; 1588 1589 error = 0; 1590 1591 out: 1592 return error; 1593 } 1594 1595 /* 1596 * Read the super block of an MS-DOS FS. 1597 */ 1598 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1599 void (*setup)(struct super_block *)) 1600 { 1601 struct inode *root_inode = NULL, *fat_inode = NULL; 1602 struct inode *fsinfo_inode = NULL; 1603 struct buffer_head *bh; 1604 struct fat_bios_param_block bpb; 1605 struct msdos_sb_info *sbi; 1606 u16 logical_sector_size; 1607 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1608 int debug; 1609 long error; 1610 char buf[50]; 1611 struct timespec64 ts; 1612 1613 /* 1614 * GFP_KERNEL is ok here, because while we do hold the 1615 * superblock lock, memory pressure can't call back into 1616 * the filesystem, since we're only just about to mount 1617 * it and have no inodes etc active! 1618 */ 1619 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1620 if (!sbi) 1621 return -ENOMEM; 1622 sb->s_fs_info = sbi; 1623 1624 sb->s_flags |= SB_NODIRATIME; 1625 sb->s_magic = MSDOS_SUPER_MAGIC; 1626 sb->s_op = &fat_sops; 1627 sb->s_export_op = &fat_export_ops; 1628 /* 1629 * fat timestamps are complex and truncated by fat itself, so 1630 * we set 1 here to be fast 1631 */ 1632 sb->s_time_gran = 1; 1633 mutex_init(&sbi->nfs_build_inode_lock); 1634 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1635 DEFAULT_RATELIMIT_BURST); 1636 1637 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1638 if (error) 1639 goto out_fail; 1640 1641 setup(sb); /* flavour-specific stuff that needs options */ 1642 1643 error = -EIO; 1644 sb_min_blocksize(sb, 512); 1645 bh = sb_bread(sb, 0); 1646 if (bh == NULL) { 1647 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1648 goto out_fail; 1649 } 1650 1651 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1652 &bpb); 1653 if (error == -EINVAL && sbi->options.dos1xfloppy) 1654 error = fat_read_static_bpb(sb, 1655 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1656 brelse(bh); 1657 1658 if (error == -EINVAL) 1659 goto out_invalid; 1660 else if (error) 1661 goto out_fail; 1662 1663 logical_sector_size = bpb.fat_sector_size; 1664 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1665 1666 error = -EIO; 1667 if (logical_sector_size < sb->s_blocksize) { 1668 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1669 " (logical sector size = %u)", logical_sector_size); 1670 goto out_fail; 1671 } 1672 1673 if (logical_sector_size > sb->s_blocksize) { 1674 struct buffer_head *bh_resize; 1675 1676 if (!sb_set_blocksize(sb, logical_sector_size)) { 1677 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1678 logical_sector_size); 1679 goto out_fail; 1680 } 1681 1682 /* Verify that the larger boot sector is fully readable */ 1683 bh_resize = sb_bread(sb, 0); 1684 if (bh_resize == NULL) { 1685 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1686 " (logical sector size = %lu)", 1687 sb->s_blocksize); 1688 goto out_fail; 1689 } 1690 brelse(bh_resize); 1691 } 1692 1693 mutex_init(&sbi->s_lock); 1694 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1695 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1696 sbi->fats = bpb.fat_fats; 1697 sbi->fat_bits = 0; /* Don't know yet */ 1698 sbi->fat_start = bpb.fat_reserved; 1699 sbi->fat_length = bpb.fat_fat_length; 1700 sbi->root_cluster = 0; 1701 sbi->free_clusters = -1; /* Don't know yet */ 1702 sbi->free_clus_valid = 0; 1703 sbi->prev_free = FAT_START_ENT; 1704 sb->s_maxbytes = 0xffffffff; 1705 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1706 sb->s_time_min = ts.tv_sec; 1707 1708 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1709 cpu_to_le16(FAT_DATE_MAX), 0); 1710 sb->s_time_max = ts.tv_sec; 1711 1712 if (!sbi->fat_length && bpb.fat32_length) { 1713 struct fat_boot_fsinfo *fsinfo; 1714 struct buffer_head *fsinfo_bh; 1715 1716 /* Must be FAT32 */ 1717 sbi->fat_bits = 32; 1718 sbi->fat_length = bpb.fat32_length; 1719 sbi->root_cluster = bpb.fat32_root_cluster; 1720 1721 /* MC - if info_sector is 0, don't multiply by 0 */ 1722 sbi->fsinfo_sector = bpb.fat32_info_sector; 1723 if (sbi->fsinfo_sector == 0) 1724 sbi->fsinfo_sector = 1; 1725 1726 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1727 if (fsinfo_bh == NULL) { 1728 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1729 " (sector = %lu)", sbi->fsinfo_sector); 1730 goto out_fail; 1731 } 1732 1733 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1734 if (!IS_FSINFO(fsinfo)) { 1735 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1736 "0x%08x, 0x%08x (sector = %lu)", 1737 le32_to_cpu(fsinfo->signature1), 1738 le32_to_cpu(fsinfo->signature2), 1739 sbi->fsinfo_sector); 1740 } else { 1741 if (sbi->options.usefree) 1742 sbi->free_clus_valid = 1; 1743 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1744 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1745 } 1746 1747 brelse(fsinfo_bh); 1748 } 1749 1750 /* interpret volume ID as a little endian 32 bit integer */ 1751 if (is_fat32(sbi)) 1752 sbi->vol_id = bpb.fat32_vol_id; 1753 else /* fat 16 or 12 */ 1754 sbi->vol_id = bpb.fat16_vol_id; 1755 1756 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1757 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1758 1759 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1760 sbi->dir_entries = bpb.fat_dir_entries; 1761 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1762 if (!silent) 1763 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1764 " (%u)", sbi->dir_entries); 1765 goto out_invalid; 1766 } 1767 1768 rootdir_sectors = sbi->dir_entries 1769 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1770 sbi->data_start = sbi->dir_start + rootdir_sectors; 1771 total_sectors = bpb.fat_sectors; 1772 if (total_sectors == 0) 1773 total_sectors = bpb.fat_total_sect; 1774 1775 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1776 1777 if (!is_fat32(sbi)) 1778 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1779 1780 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1781 if (is_fat32(sbi)) 1782 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1783 else /* fat 16 or 12 */ 1784 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1785 1786 /* check that FAT table does not overflow */ 1787 fat_clusters = calc_fat_clusters(sb); 1788 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1789 if (total_clusters > max_fat(sb)) { 1790 if (!silent) 1791 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1792 total_clusters); 1793 goto out_invalid; 1794 } 1795 1796 sbi->max_cluster = total_clusters + FAT_START_ENT; 1797 /* check the free_clusters, it's not necessarily correct */ 1798 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1799 sbi->free_clusters = -1; 1800 /* check the prev_free, it's not necessarily correct */ 1801 sbi->prev_free %= sbi->max_cluster; 1802 if (sbi->prev_free < FAT_START_ENT) 1803 sbi->prev_free = FAT_START_ENT; 1804 1805 /* set up enough so that it can read an inode */ 1806 fat_hash_init(sb); 1807 dir_hash_init(sb); 1808 fat_ent_access_init(sb); 1809 1810 /* 1811 * The low byte of the first FAT entry must have the same value as 1812 * the media field of the boot sector. But in real world, too many 1813 * devices are writing wrong values. So, removed that validity check. 1814 * 1815 * The removed check compared the first FAT entry to a value dependent 1816 * on the media field like this: 1817 * == (0x0F00 | media), for FAT12 1818 * == (0XFF00 | media), for FAT16 1819 * == (0x0FFFFF | media), for FAT32 1820 */ 1821 1822 error = -EINVAL; 1823 sprintf(buf, "cp%d", sbi->options.codepage); 1824 sbi->nls_disk = load_nls(buf); 1825 if (!sbi->nls_disk) { 1826 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1827 goto out_fail; 1828 } 1829 1830 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1831 if (sbi->options.isvfat) { 1832 sbi->nls_io = load_nls(sbi->options.iocharset); 1833 if (!sbi->nls_io) { 1834 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1835 sbi->options.iocharset); 1836 goto out_fail; 1837 } 1838 } 1839 1840 error = -ENOMEM; 1841 fat_inode = new_inode(sb); 1842 if (!fat_inode) 1843 goto out_fail; 1844 sbi->fat_inode = fat_inode; 1845 1846 fsinfo_inode = new_inode(sb); 1847 if (!fsinfo_inode) 1848 goto out_fail; 1849 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1850 sbi->fsinfo_inode = fsinfo_inode; 1851 insert_inode_hash(fsinfo_inode); 1852 1853 root_inode = new_inode(sb); 1854 if (!root_inode) 1855 goto out_fail; 1856 root_inode->i_ino = MSDOS_ROOT_INO; 1857 inode_set_iversion(root_inode, 1); 1858 error = fat_read_root(root_inode); 1859 if (error < 0) { 1860 iput(root_inode); 1861 goto out_fail; 1862 } 1863 error = -ENOMEM; 1864 insert_inode_hash(root_inode); 1865 fat_attach(root_inode, 0); 1866 sb->s_root = d_make_root(root_inode); 1867 if (!sb->s_root) { 1868 fat_msg(sb, KERN_ERR, "get root inode failed"); 1869 goto out_fail; 1870 } 1871 1872 if (sbi->options.discard && !bdev_max_discard_sectors(sb->s_bdev)) 1873 fat_msg(sb, KERN_WARNING, 1874 "mounting with \"discard\" option, but the device does not support discard"); 1875 1876 fat_set_state(sb, 1, 0); 1877 return 0; 1878 1879 out_invalid: 1880 error = -EINVAL; 1881 if (!silent) 1882 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1883 1884 out_fail: 1885 iput(fsinfo_inode); 1886 iput(fat_inode); 1887 unload_nls(sbi->nls_io); 1888 unload_nls(sbi->nls_disk); 1889 fat_reset_iocharset(&sbi->options); 1890 sb->s_fs_info = NULL; 1891 kfree(sbi); 1892 return error; 1893 } 1894 1895 EXPORT_SYMBOL_GPL(fat_fill_super); 1896 1897 /* 1898 * helper function for fat_flush_inodes. This writes both the inode 1899 * and the file data blocks, waiting for in flight data blocks before 1900 * the start of the call. It does not wait for any io started 1901 * during the call 1902 */ 1903 static int writeback_inode(struct inode *inode) 1904 { 1905 1906 int ret; 1907 1908 /* if we used wait=1, sync_inode_metadata waits for the io for the 1909 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1910 * and filemap_fdatawrite is used for the data blocks 1911 */ 1912 ret = sync_inode_metadata(inode, 0); 1913 if (!ret) 1914 ret = filemap_fdatawrite(inode->i_mapping); 1915 return ret; 1916 } 1917 1918 /* 1919 * write data and metadata corresponding to i1 and i2. The io is 1920 * started but we do not wait for any of it to finish. 1921 * 1922 * filemap_flush is used for the block device, so if there is a dirty 1923 * page for a block already in flight, we will not wait and start the 1924 * io over again 1925 */ 1926 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1927 { 1928 int ret = 0; 1929 if (!MSDOS_SB(sb)->options.flush) 1930 return 0; 1931 if (i1) 1932 ret = writeback_inode(i1); 1933 if (!ret && i2) 1934 ret = writeback_inode(i2); 1935 if (!ret) 1936 ret = sync_blockdev_nowait(sb->s_bdev); 1937 return ret; 1938 } 1939 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1940 1941 static int __init init_fat_fs(void) 1942 { 1943 int err; 1944 1945 err = fat_cache_init(); 1946 if (err) 1947 return err; 1948 1949 err = fat_init_inodecache(); 1950 if (err) 1951 goto failed; 1952 1953 return 0; 1954 1955 failed: 1956 fat_cache_destroy(); 1957 return err; 1958 } 1959 1960 static void __exit exit_fat_fs(void) 1961 { 1962 fat_cache_destroy(); 1963 fat_destroy_inodecache(); 1964 } 1965 1966 module_init(init_fat_fs) 1967 module_exit(exit_fat_fs) 1968 1969 MODULE_LICENSE("GPL"); 1970