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_writepage(struct page *page, struct writeback_control *wbc) 198 { 199 return block_write_full_page(page, fat_get_block, wbc); 200 } 201 202 static int fat_writepages(struct address_space *mapping, 203 struct writeback_control *wbc) 204 { 205 return mpage_writepages(mapping, wbc, fat_get_block); 206 } 207 208 static int fat_read_folio(struct file *file, struct folio *folio) 209 { 210 return mpage_read_folio(folio, fat_get_block); 211 } 212 213 static void fat_readahead(struct readahead_control *rac) 214 { 215 mpage_readahead(rac, fat_get_block); 216 } 217 218 static void fat_write_failed(struct address_space *mapping, loff_t to) 219 { 220 struct inode *inode = mapping->host; 221 222 if (to > inode->i_size) { 223 truncate_pagecache(inode, inode->i_size); 224 fat_truncate_blocks(inode, inode->i_size); 225 } 226 } 227 228 static int fat_write_begin(struct file *file, struct address_space *mapping, 229 loff_t pos, unsigned len, 230 struct page **pagep, void **fsdata) 231 { 232 int err; 233 234 *pagep = NULL; 235 err = cont_write_begin(file, mapping, pos, len, 236 pagep, fsdata, fat_get_block, 237 &MSDOS_I(mapping->host)->mmu_private); 238 if (err < 0) 239 fat_write_failed(mapping, pos + len); 240 return err; 241 } 242 243 static int fat_write_end(struct file *file, struct address_space *mapping, 244 loff_t pos, unsigned len, unsigned copied, 245 struct page *pagep, void *fsdata) 246 { 247 struct inode *inode = mapping->host; 248 int err; 249 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 250 if (err < len) 251 fat_write_failed(mapping, pos + len); 252 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 253 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 254 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 255 mark_inode_dirty(inode); 256 } 257 return err; 258 } 259 260 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 261 { 262 struct file *file = iocb->ki_filp; 263 struct address_space *mapping = file->f_mapping; 264 struct inode *inode = mapping->host; 265 size_t count = iov_iter_count(iter); 266 loff_t offset = iocb->ki_pos; 267 ssize_t ret; 268 269 if (iov_iter_rw(iter) == WRITE) { 270 /* 271 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 272 * so we need to update the ->mmu_private to block boundary. 273 * 274 * But we must fill the remaining area or hole by nul for 275 * updating ->mmu_private. 276 * 277 * Return 0, and fallback to normal buffered write. 278 */ 279 loff_t size = offset + count; 280 if (MSDOS_I(inode)->mmu_private < size) 281 return 0; 282 } 283 284 /* 285 * FAT need to use the DIO_LOCKING for avoiding the race 286 * condition of fat_get_block() and ->truncate(). 287 */ 288 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 289 if (ret < 0 && iov_iter_rw(iter) == WRITE) 290 fat_write_failed(mapping, offset + count); 291 292 return ret; 293 } 294 295 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 296 struct buffer_head *bh_result, int create) 297 { 298 struct super_block *sb = inode->i_sb; 299 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 300 int err; 301 sector_t bmap; 302 unsigned long mapped_blocks; 303 304 BUG_ON(create != 0); 305 306 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 307 if (err) 308 return err; 309 310 if (bmap) { 311 map_bh(bh_result, sb, bmap); 312 max_blocks = min(mapped_blocks, max_blocks); 313 } 314 315 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 316 317 return 0; 318 } 319 320 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 321 { 322 sector_t blocknr; 323 324 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 325 down_read(&MSDOS_I(mapping->host)->truncate_lock); 326 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 327 up_read(&MSDOS_I(mapping->host)->truncate_lock); 328 329 return blocknr; 330 } 331 332 /* 333 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 334 * up to the end of the block which corresponds to `from'. 335 * This is required during truncate to physically zeroout the tail end 336 * of that block so it doesn't yield old data if the file is later grown. 337 * Also, avoid causing failure from fsx for cases of "data past EOF" 338 */ 339 int fat_block_truncate_page(struct inode *inode, loff_t from) 340 { 341 return block_truncate_page(inode->i_mapping, from, fat_get_block); 342 } 343 344 static const struct address_space_operations fat_aops = { 345 .dirty_folio = block_dirty_folio, 346 .invalidate_folio = block_invalidate_folio, 347 .read_folio = fat_read_folio, 348 .readahead = fat_readahead, 349 .writepage = fat_writepage, 350 .writepages = fat_writepages, 351 .write_begin = fat_write_begin, 352 .write_end = fat_write_end, 353 .direct_IO = fat_direct_IO, 354 .bmap = _fat_bmap 355 }; 356 357 /* 358 * New FAT inode stuff. We do the following: 359 * a) i_ino is constant and has nothing with on-disk location. 360 * b) FAT manages its own cache of directory entries. 361 * c) *This* cache is indexed by on-disk location. 362 * d) inode has an associated directory entry, all right, but 363 * it may be unhashed. 364 * e) currently entries are stored within struct inode. That should 365 * change. 366 * f) we deal with races in the following way: 367 * 1. readdir() and lookup() do FAT-dir-cache lookup. 368 * 2. rename() unhashes the F-d-c entry and rehashes it in 369 * a new place. 370 * 3. unlink() and rmdir() unhash F-d-c entry. 371 * 4. fat_write_inode() checks whether the thing is unhashed. 372 * If it is we silently return. If it isn't we do bread(), 373 * check if the location is still valid and retry if it 374 * isn't. Otherwise we do changes. 375 * 5. Spinlock is used to protect hash/unhash/location check/lookup 376 * 6. fat_evict_inode() unhashes the F-d-c entry. 377 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 378 * and consider negative result as cache miss. 379 */ 380 381 static void fat_hash_init(struct super_block *sb) 382 { 383 struct msdos_sb_info *sbi = MSDOS_SB(sb); 384 int i; 385 386 spin_lock_init(&sbi->inode_hash_lock); 387 for (i = 0; i < FAT_HASH_SIZE; i++) 388 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 389 } 390 391 static inline unsigned long fat_hash(loff_t i_pos) 392 { 393 return hash_32(i_pos, FAT_HASH_BITS); 394 } 395 396 static void dir_hash_init(struct super_block *sb) 397 { 398 struct msdos_sb_info *sbi = MSDOS_SB(sb); 399 int i; 400 401 spin_lock_init(&sbi->dir_hash_lock); 402 for (i = 0; i < FAT_HASH_SIZE; i++) 403 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 404 } 405 406 void fat_attach(struct inode *inode, loff_t i_pos) 407 { 408 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 409 410 if (inode->i_ino != MSDOS_ROOT_INO) { 411 struct hlist_head *head = sbi->inode_hashtable 412 + fat_hash(i_pos); 413 414 spin_lock(&sbi->inode_hash_lock); 415 MSDOS_I(inode)->i_pos = i_pos; 416 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 417 spin_unlock(&sbi->inode_hash_lock); 418 } 419 420 /* If NFS support is enabled, cache the mapping of start cluster 421 * to directory inode. This is used during reconnection of 422 * dentries to the filesystem root. 423 */ 424 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 425 struct hlist_head *d_head = sbi->dir_hashtable; 426 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 427 428 spin_lock(&sbi->dir_hash_lock); 429 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 430 spin_unlock(&sbi->dir_hash_lock); 431 } 432 } 433 EXPORT_SYMBOL_GPL(fat_attach); 434 435 void fat_detach(struct inode *inode) 436 { 437 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 438 spin_lock(&sbi->inode_hash_lock); 439 MSDOS_I(inode)->i_pos = 0; 440 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 441 spin_unlock(&sbi->inode_hash_lock); 442 443 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 444 spin_lock(&sbi->dir_hash_lock); 445 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 446 spin_unlock(&sbi->dir_hash_lock); 447 } 448 } 449 EXPORT_SYMBOL_GPL(fat_detach); 450 451 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 452 { 453 struct msdos_sb_info *sbi = MSDOS_SB(sb); 454 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 455 struct msdos_inode_info *i; 456 struct inode *inode = NULL; 457 458 spin_lock(&sbi->inode_hash_lock); 459 hlist_for_each_entry(i, head, i_fat_hash) { 460 BUG_ON(i->vfs_inode.i_sb != sb); 461 if (i->i_pos != i_pos) 462 continue; 463 inode = igrab(&i->vfs_inode); 464 if (inode) 465 break; 466 } 467 spin_unlock(&sbi->inode_hash_lock); 468 return inode; 469 } 470 471 static int is_exec(unsigned char *extension) 472 { 473 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 474 475 for (walk = exe_extensions; *walk; walk += 3) 476 if (!strncmp(extension, walk, 3)) 477 return 1; 478 return 0; 479 } 480 481 static int fat_calc_dir_size(struct inode *inode) 482 { 483 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 484 int ret, fclus, dclus; 485 486 inode->i_size = 0; 487 if (MSDOS_I(inode)->i_start == 0) 488 return 0; 489 490 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 491 if (ret < 0) 492 return ret; 493 inode->i_size = (fclus + 1) << sbi->cluster_bits; 494 495 return 0; 496 } 497 498 static int fat_validate_dir(struct inode *dir) 499 { 500 struct super_block *sb = dir->i_sb; 501 502 if (dir->i_nlink < 2) { 503 /* Directory should have "."/".." entries at least. */ 504 fat_fs_error(sb, "corrupted directory (invalid entries)"); 505 return -EIO; 506 } 507 if (MSDOS_I(dir)->i_start == 0 || 508 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 509 /* Directory should point valid cluster. */ 510 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 511 return -EIO; 512 } 513 return 0; 514 } 515 516 /* doesn't deal with root inode */ 517 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 518 { 519 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 520 int error; 521 522 MSDOS_I(inode)->i_pos = 0; 523 inode->i_uid = sbi->options.fs_uid; 524 inode->i_gid = sbi->options.fs_gid; 525 inode_inc_iversion(inode); 526 inode->i_generation = prandom_u32(); 527 528 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 529 inode->i_generation &= ~1; 530 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 531 inode->i_op = sbi->dir_ops; 532 inode->i_fop = &fat_dir_operations; 533 534 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 535 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 536 error = fat_calc_dir_size(inode); 537 if (error < 0) 538 return error; 539 MSDOS_I(inode)->mmu_private = inode->i_size; 540 541 set_nlink(inode, fat_subdirs(inode)); 542 543 error = fat_validate_dir(inode); 544 if (error < 0) 545 return error; 546 } else { /* not a directory */ 547 inode->i_generation |= 1; 548 inode->i_mode = fat_make_mode(sbi, de->attr, 549 ((sbi->options.showexec && !is_exec(de->name + 8)) 550 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 551 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 552 553 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 554 inode->i_size = le32_to_cpu(de->size); 555 inode->i_op = &fat_file_inode_operations; 556 inode->i_fop = &fat_file_operations; 557 inode->i_mapping->a_ops = &fat_aops; 558 MSDOS_I(inode)->mmu_private = inode->i_size; 559 } 560 if (de->attr & ATTR_SYS) { 561 if (sbi->options.sys_immutable) 562 inode->i_flags |= S_IMMUTABLE; 563 } 564 fat_save_attrs(inode, de->attr); 565 566 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 567 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 568 569 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 570 inode->i_ctime = inode->i_mtime; 571 if (sbi->options.isvfat) { 572 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 573 fat_time_fat2unix(sbi, &MSDOS_I(inode)->i_crtime, de->ctime, 574 de->cdate, de->ctime_cs); 575 } else 576 inode->i_atime = fat_truncate_atime(sbi, &inode->i_mtime); 577 578 return 0; 579 } 580 581 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 582 { 583 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 584 mutex_lock(&sbi->nfs_build_inode_lock); 585 } 586 587 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 588 { 589 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 590 mutex_unlock(&sbi->nfs_build_inode_lock); 591 } 592 593 struct inode *fat_build_inode(struct super_block *sb, 594 struct msdos_dir_entry *de, loff_t i_pos) 595 { 596 struct inode *inode; 597 int err; 598 599 fat_lock_build_inode(MSDOS_SB(sb)); 600 inode = fat_iget(sb, i_pos); 601 if (inode) 602 goto out; 603 inode = new_inode(sb); 604 if (!inode) { 605 inode = ERR_PTR(-ENOMEM); 606 goto out; 607 } 608 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 609 inode_set_iversion(inode, 1); 610 err = fat_fill_inode(inode, de); 611 if (err) { 612 iput(inode); 613 inode = ERR_PTR(err); 614 goto out; 615 } 616 fat_attach(inode, i_pos); 617 insert_inode_hash(inode); 618 out: 619 fat_unlock_build_inode(MSDOS_SB(sb)); 620 return inode; 621 } 622 623 EXPORT_SYMBOL_GPL(fat_build_inode); 624 625 static int __fat_write_inode(struct inode *inode, int wait); 626 627 static void fat_free_eofblocks(struct inode *inode) 628 { 629 /* Release unwritten fallocated blocks on inode eviction. */ 630 if ((inode->i_blocks << 9) > 631 round_up(MSDOS_I(inode)->mmu_private, 632 MSDOS_SB(inode->i_sb)->cluster_size)) { 633 int err; 634 635 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 636 /* Fallocate results in updating the i_start/iogstart 637 * for the zero byte file. So, make it return to 638 * original state during evict and commit it to avoid 639 * any corruption on the next access to the cluster 640 * chain for the file. 641 */ 642 err = __fat_write_inode(inode, inode_needs_sync(inode)); 643 if (err) { 644 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 645 "update on disk inode for unused " 646 "fallocated blocks, inode could be " 647 "corrupted. Please run fsck"); 648 } 649 650 } 651 } 652 653 static void fat_evict_inode(struct inode *inode) 654 { 655 truncate_inode_pages_final(&inode->i_data); 656 if (!inode->i_nlink) { 657 inode->i_size = 0; 658 fat_truncate_blocks(inode, 0); 659 } else 660 fat_free_eofblocks(inode); 661 662 invalidate_inode_buffers(inode); 663 clear_inode(inode); 664 fat_cache_inval_inode(inode); 665 fat_detach(inode); 666 } 667 668 static void fat_set_state(struct super_block *sb, 669 unsigned int set, unsigned int force) 670 { 671 struct buffer_head *bh; 672 struct fat_boot_sector *b; 673 struct msdos_sb_info *sbi = MSDOS_SB(sb); 674 675 /* do not change any thing if mounted read only */ 676 if (sb_rdonly(sb) && !force) 677 return; 678 679 /* do not change state if fs was dirty */ 680 if (sbi->dirty) { 681 /* warn only on set (mount). */ 682 if (set) 683 fat_msg(sb, KERN_WARNING, "Volume was not properly " 684 "unmounted. Some data may be corrupt. " 685 "Please run fsck."); 686 return; 687 } 688 689 bh = sb_bread(sb, 0); 690 if (bh == NULL) { 691 fat_msg(sb, KERN_ERR, "unable to read boot sector " 692 "to mark fs as dirty"); 693 return; 694 } 695 696 b = (struct fat_boot_sector *) bh->b_data; 697 698 if (is_fat32(sbi)) { 699 if (set) 700 b->fat32.state |= FAT_STATE_DIRTY; 701 else 702 b->fat32.state &= ~FAT_STATE_DIRTY; 703 } else /* fat 16 and 12 */ { 704 if (set) 705 b->fat16.state |= FAT_STATE_DIRTY; 706 else 707 b->fat16.state &= ~FAT_STATE_DIRTY; 708 } 709 710 mark_buffer_dirty(bh); 711 sync_dirty_buffer(bh); 712 brelse(bh); 713 } 714 715 static void fat_reset_iocharset(struct fat_mount_options *opts) 716 { 717 if (opts->iocharset != fat_default_iocharset) { 718 /* Note: opts->iocharset can be NULL here */ 719 kfree(opts->iocharset); 720 opts->iocharset = fat_default_iocharset; 721 } 722 } 723 724 static void delayed_free(struct rcu_head *p) 725 { 726 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 727 unload_nls(sbi->nls_disk); 728 unload_nls(sbi->nls_io); 729 fat_reset_iocharset(&sbi->options); 730 kfree(sbi); 731 } 732 733 static void fat_put_super(struct super_block *sb) 734 { 735 struct msdos_sb_info *sbi = MSDOS_SB(sb); 736 737 fat_set_state(sb, 0, 0); 738 739 iput(sbi->fsinfo_inode); 740 iput(sbi->fat_inode); 741 742 call_rcu(&sbi->rcu, delayed_free); 743 } 744 745 static struct kmem_cache *fat_inode_cachep; 746 747 static struct inode *fat_alloc_inode(struct super_block *sb) 748 { 749 struct msdos_inode_info *ei; 750 ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS); 751 if (!ei) 752 return NULL; 753 754 init_rwsem(&ei->truncate_lock); 755 /* Zeroing to allow iput() even if partial initialized inode. */ 756 ei->mmu_private = 0; 757 ei->i_start = 0; 758 ei->i_logstart = 0; 759 ei->i_attrs = 0; 760 ei->i_pos = 0; 761 ei->i_crtime.tv_sec = 0; 762 ei->i_crtime.tv_nsec = 0; 763 764 return &ei->vfs_inode; 765 } 766 767 static void fat_free_inode(struct inode *inode) 768 { 769 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 770 } 771 772 static void init_once(void *foo) 773 { 774 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 775 776 spin_lock_init(&ei->cache_lru_lock); 777 ei->nr_caches = 0; 778 ei->cache_valid_id = FAT_CACHE_VALID + 1; 779 INIT_LIST_HEAD(&ei->cache_lru); 780 INIT_HLIST_NODE(&ei->i_fat_hash); 781 INIT_HLIST_NODE(&ei->i_dir_hash); 782 inode_init_once(&ei->vfs_inode); 783 } 784 785 static int __init fat_init_inodecache(void) 786 { 787 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 788 sizeof(struct msdos_inode_info), 789 0, (SLAB_RECLAIM_ACCOUNT| 790 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 791 init_once); 792 if (fat_inode_cachep == NULL) 793 return -ENOMEM; 794 return 0; 795 } 796 797 static void __exit fat_destroy_inodecache(void) 798 { 799 /* 800 * Make sure all delayed rcu free inodes are flushed before we 801 * destroy cache. 802 */ 803 rcu_barrier(); 804 kmem_cache_destroy(fat_inode_cachep); 805 } 806 807 static int fat_remount(struct super_block *sb, int *flags, char *data) 808 { 809 bool new_rdonly; 810 struct msdos_sb_info *sbi = MSDOS_SB(sb); 811 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 812 813 sync_filesystem(sb); 814 815 /* make sure we update state on remount. */ 816 new_rdonly = *flags & SB_RDONLY; 817 if (new_rdonly != sb_rdonly(sb)) { 818 if (new_rdonly) 819 fat_set_state(sb, 0, 0); 820 else 821 fat_set_state(sb, 1, 1); 822 } 823 return 0; 824 } 825 826 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 loff_t i_pos; 858 sector_t blocknr; 859 int err, offset; 860 861 if (inode->i_ino == MSDOS_ROOT_INO) 862 return 0; 863 864 retry: 865 i_pos = fat_i_pos_read(sbi, inode); 866 if (!i_pos) 867 return 0; 868 869 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 870 bh = sb_bread(sb, blocknr); 871 if (!bh) { 872 fat_msg(sb, KERN_ERR, "unable to read inode block " 873 "for updating (i_pos %lld)", i_pos); 874 return -EIO; 875 } 876 spin_lock(&sbi->inode_hash_lock); 877 if (i_pos != MSDOS_I(inode)->i_pos) { 878 spin_unlock(&sbi->inode_hash_lock); 879 brelse(bh); 880 goto retry; 881 } 882 883 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 884 if (S_ISDIR(inode->i_mode)) 885 raw_entry->size = 0; 886 else 887 raw_entry->size = cpu_to_le32(inode->i_size); 888 raw_entry->attr = fat_make_attrs(inode); 889 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 890 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 891 &raw_entry->date, NULL); 892 if (sbi->options.isvfat) { 893 __le16 atime; 894 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 895 &raw_entry->adate, NULL); 896 fat_time_unix2fat(sbi, &MSDOS_I(inode)->i_crtime, &raw_entry->ctime, 897 &raw_entry->cdate, &raw_entry->ctime_cs); 898 } 899 spin_unlock(&sbi->inode_hash_lock); 900 mark_buffer_dirty(bh); 901 err = 0; 902 if (wait) 903 err = sync_dirty_buffer(bh); 904 brelse(bh); 905 return err; 906 } 907 908 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 909 { 910 int err; 911 912 if (inode->i_ino == MSDOS_FSINFO_INO) { 913 struct super_block *sb = inode->i_sb; 914 915 mutex_lock(&MSDOS_SB(sb)->s_lock); 916 err = fat_clusters_flush(sb); 917 mutex_unlock(&MSDOS_SB(sb)->s_lock); 918 } else 919 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 920 921 return err; 922 } 923 924 int fat_sync_inode(struct inode *inode) 925 { 926 return __fat_write_inode(inode, 1); 927 } 928 929 EXPORT_SYMBOL_GPL(fat_sync_inode); 930 931 static int fat_show_options(struct seq_file *m, struct dentry *root); 932 static const struct super_operations fat_sops = { 933 .alloc_inode = fat_alloc_inode, 934 .free_inode = fat_free_inode, 935 .write_inode = fat_write_inode, 936 .evict_inode = fat_evict_inode, 937 .put_super = fat_put_super, 938 .statfs = fat_statfs, 939 .remount_fs = fat_remount, 940 941 .show_options = fat_show_options, 942 }; 943 944 static int fat_show_options(struct seq_file *m, struct dentry *root) 945 { 946 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 947 struct fat_mount_options *opts = &sbi->options; 948 int isvfat = opts->isvfat; 949 950 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 951 seq_printf(m, ",uid=%u", 952 from_kuid_munged(&init_user_ns, opts->fs_uid)); 953 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 954 seq_printf(m, ",gid=%u", 955 from_kgid_munged(&init_user_ns, opts->fs_gid)); 956 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 957 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 958 if (opts->allow_utime) 959 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 960 if (sbi->nls_disk) 961 /* strip "cp" prefix from displayed option */ 962 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 963 if (isvfat) { 964 if (sbi->nls_io) 965 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 966 967 switch (opts->shortname) { 968 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 969 seq_puts(m, ",shortname=win95"); 970 break; 971 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 972 seq_puts(m, ",shortname=winnt"); 973 break; 974 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 975 seq_puts(m, ",shortname=mixed"); 976 break; 977 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 978 seq_puts(m, ",shortname=lower"); 979 break; 980 default: 981 seq_puts(m, ",shortname=unknown"); 982 break; 983 } 984 } 985 if (opts->name_check != 'n') 986 seq_printf(m, ",check=%c", opts->name_check); 987 if (opts->usefree) 988 seq_puts(m, ",usefree"); 989 if (opts->quiet) 990 seq_puts(m, ",quiet"); 991 if (opts->showexec) 992 seq_puts(m, ",showexec"); 993 if (opts->sys_immutable) 994 seq_puts(m, ",sys_immutable"); 995 if (!isvfat) { 996 if (opts->dotsOK) 997 seq_puts(m, ",dotsOK=yes"); 998 if (opts->nocase) 999 seq_puts(m, ",nocase"); 1000 } else { 1001 if (opts->utf8) 1002 seq_puts(m, ",utf8"); 1003 if (opts->unicode_xlate) 1004 seq_puts(m, ",uni_xlate"); 1005 if (!opts->numtail) 1006 seq_puts(m, ",nonumtail"); 1007 if (opts->rodir) 1008 seq_puts(m, ",rodir"); 1009 } 1010 if (opts->flush) 1011 seq_puts(m, ",flush"); 1012 if (opts->tz_set) { 1013 if (opts->time_offset) 1014 seq_printf(m, ",time_offset=%d", opts->time_offset); 1015 else 1016 seq_puts(m, ",tz=UTC"); 1017 } 1018 if (opts->errors == FAT_ERRORS_CONT) 1019 seq_puts(m, ",errors=continue"); 1020 else if (opts->errors == FAT_ERRORS_PANIC) 1021 seq_puts(m, ",errors=panic"); 1022 else 1023 seq_puts(m, ",errors=remount-ro"); 1024 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1025 seq_puts(m, ",nfs=nostale_ro"); 1026 else if (opts->nfs) 1027 seq_puts(m, ",nfs=stale_rw"); 1028 if (opts->discard) 1029 seq_puts(m, ",discard"); 1030 if (opts->dos1xfloppy) 1031 seq_puts(m, ",dos1xfloppy"); 1032 1033 return 0; 1034 } 1035 1036 enum { 1037 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1038 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1039 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1040 Opt_immutable, Opt_dots, Opt_nodots, 1041 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1042 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1043 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1044 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1045 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1046 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1047 }; 1048 1049 static const match_table_t fat_tokens = { 1050 {Opt_check_r, "check=relaxed"}, 1051 {Opt_check_s, "check=strict"}, 1052 {Opt_check_n, "check=normal"}, 1053 {Opt_check_r, "check=r"}, 1054 {Opt_check_s, "check=s"}, 1055 {Opt_check_n, "check=n"}, 1056 {Opt_uid, "uid=%u"}, 1057 {Opt_gid, "gid=%u"}, 1058 {Opt_umask, "umask=%o"}, 1059 {Opt_dmask, "dmask=%o"}, 1060 {Opt_fmask, "fmask=%o"}, 1061 {Opt_allow_utime, "allow_utime=%o"}, 1062 {Opt_codepage, "codepage=%u"}, 1063 {Opt_usefree, "usefree"}, 1064 {Opt_nocase, "nocase"}, 1065 {Opt_quiet, "quiet"}, 1066 {Opt_showexec, "showexec"}, 1067 {Opt_debug, "debug"}, 1068 {Opt_immutable, "sys_immutable"}, 1069 {Opt_flush, "flush"}, 1070 {Opt_tz_utc, "tz=UTC"}, 1071 {Opt_time_offset, "time_offset=%d"}, 1072 {Opt_err_cont, "errors=continue"}, 1073 {Opt_err_panic, "errors=panic"}, 1074 {Opt_err_ro, "errors=remount-ro"}, 1075 {Opt_discard, "discard"}, 1076 {Opt_nfs_stale_rw, "nfs"}, 1077 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1078 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1079 {Opt_dos1xfloppy, "dos1xfloppy"}, 1080 {Opt_obsolete, "conv=binary"}, 1081 {Opt_obsolete, "conv=text"}, 1082 {Opt_obsolete, "conv=auto"}, 1083 {Opt_obsolete, "conv=b"}, 1084 {Opt_obsolete, "conv=t"}, 1085 {Opt_obsolete, "conv=a"}, 1086 {Opt_obsolete, "fat=%u"}, 1087 {Opt_obsolete, "blocksize=%u"}, 1088 {Opt_obsolete, "cvf_format=%20s"}, 1089 {Opt_obsolete, "cvf_options=%100s"}, 1090 {Opt_obsolete, "posix"}, 1091 {Opt_err, NULL}, 1092 }; 1093 static const match_table_t msdos_tokens = { 1094 {Opt_nodots, "nodots"}, 1095 {Opt_nodots, "dotsOK=no"}, 1096 {Opt_dots, "dots"}, 1097 {Opt_dots, "dotsOK=yes"}, 1098 {Opt_err, NULL} 1099 }; 1100 static const match_table_t vfat_tokens = { 1101 {Opt_charset, "iocharset=%s"}, 1102 {Opt_shortname_lower, "shortname=lower"}, 1103 {Opt_shortname_win95, "shortname=win95"}, 1104 {Opt_shortname_winnt, "shortname=winnt"}, 1105 {Opt_shortname_mixed, "shortname=mixed"}, 1106 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1107 {Opt_utf8_no, "utf8=no"}, 1108 {Opt_utf8_no, "utf8=false"}, 1109 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1110 {Opt_utf8_yes, "utf8=yes"}, 1111 {Opt_utf8_yes, "utf8=true"}, 1112 {Opt_utf8_yes, "utf8"}, 1113 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1114 {Opt_uni_xl_no, "uni_xlate=no"}, 1115 {Opt_uni_xl_no, "uni_xlate=false"}, 1116 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1117 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1118 {Opt_uni_xl_yes, "uni_xlate=true"}, 1119 {Opt_uni_xl_yes, "uni_xlate"}, 1120 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1121 {Opt_nonumtail_no, "nonumtail=no"}, 1122 {Opt_nonumtail_no, "nonumtail=false"}, 1123 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1124 {Opt_nonumtail_yes, "nonumtail=yes"}, 1125 {Opt_nonumtail_yes, "nonumtail=true"}, 1126 {Opt_nonumtail_yes, "nonumtail"}, 1127 {Opt_rodir, "rodir"}, 1128 {Opt_err, NULL} 1129 }; 1130 1131 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1132 int silent, int *debug, struct fat_mount_options *opts) 1133 { 1134 char *p; 1135 substring_t args[MAX_OPT_ARGS]; 1136 int option; 1137 char *iocharset; 1138 1139 opts->isvfat = is_vfat; 1140 1141 opts->fs_uid = current_uid(); 1142 opts->fs_gid = current_gid(); 1143 opts->fs_fmask = opts->fs_dmask = current_umask(); 1144 opts->allow_utime = -1; 1145 opts->codepage = fat_default_codepage; 1146 fat_reset_iocharset(opts); 1147 if (is_vfat) { 1148 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1149 opts->rodir = 0; 1150 } else { 1151 opts->shortname = 0; 1152 opts->rodir = 1; 1153 } 1154 opts->name_check = 'n'; 1155 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1156 opts->unicode_xlate = 0; 1157 opts->numtail = 1; 1158 opts->usefree = opts->nocase = 0; 1159 opts->tz_set = 0; 1160 opts->nfs = 0; 1161 opts->errors = FAT_ERRORS_RO; 1162 *debug = 0; 1163 1164 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1165 1166 if (!options) 1167 goto out; 1168 1169 while ((p = strsep(&options, ",")) != NULL) { 1170 int token; 1171 if (!*p) 1172 continue; 1173 1174 token = match_token(p, fat_tokens, args); 1175 if (token == Opt_err) { 1176 if (is_vfat) 1177 token = match_token(p, vfat_tokens, args); 1178 else 1179 token = match_token(p, msdos_tokens, args); 1180 } 1181 switch (token) { 1182 case Opt_check_s: 1183 opts->name_check = 's'; 1184 break; 1185 case Opt_check_r: 1186 opts->name_check = 'r'; 1187 break; 1188 case Opt_check_n: 1189 opts->name_check = 'n'; 1190 break; 1191 case Opt_usefree: 1192 opts->usefree = 1; 1193 break; 1194 case Opt_nocase: 1195 if (!is_vfat) 1196 opts->nocase = 1; 1197 else { 1198 /* for backward compatibility */ 1199 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1200 | VFAT_SFN_CREATE_WIN95; 1201 } 1202 break; 1203 case Opt_quiet: 1204 opts->quiet = 1; 1205 break; 1206 case Opt_showexec: 1207 opts->showexec = 1; 1208 break; 1209 case Opt_debug: 1210 *debug = 1; 1211 break; 1212 case Opt_immutable: 1213 opts->sys_immutable = 1; 1214 break; 1215 case Opt_uid: 1216 if (match_int(&args[0], &option)) 1217 return -EINVAL; 1218 opts->fs_uid = make_kuid(current_user_ns(), option); 1219 if (!uid_valid(opts->fs_uid)) 1220 return -EINVAL; 1221 break; 1222 case Opt_gid: 1223 if (match_int(&args[0], &option)) 1224 return -EINVAL; 1225 opts->fs_gid = make_kgid(current_user_ns(), option); 1226 if (!gid_valid(opts->fs_gid)) 1227 return -EINVAL; 1228 break; 1229 case Opt_umask: 1230 if (match_octal(&args[0], &option)) 1231 return -EINVAL; 1232 opts->fs_fmask = opts->fs_dmask = option; 1233 break; 1234 case Opt_dmask: 1235 if (match_octal(&args[0], &option)) 1236 return -EINVAL; 1237 opts->fs_dmask = option; 1238 break; 1239 case Opt_fmask: 1240 if (match_octal(&args[0], &option)) 1241 return -EINVAL; 1242 opts->fs_fmask = option; 1243 break; 1244 case Opt_allow_utime: 1245 if (match_octal(&args[0], &option)) 1246 return -EINVAL; 1247 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1248 break; 1249 case Opt_codepage: 1250 if (match_int(&args[0], &option)) 1251 return -EINVAL; 1252 opts->codepage = option; 1253 break; 1254 case Opt_flush: 1255 opts->flush = 1; 1256 break; 1257 case Opt_time_offset: 1258 if (match_int(&args[0], &option)) 1259 return -EINVAL; 1260 /* 1261 * GMT+-12 zones may have DST corrections so at least 1262 * 13 hours difference is needed. Make the limit 24 1263 * just in case someone invents something unusual. 1264 */ 1265 if (option < -24 * 60 || option > 24 * 60) 1266 return -EINVAL; 1267 opts->tz_set = 1; 1268 opts->time_offset = option; 1269 break; 1270 case Opt_tz_utc: 1271 opts->tz_set = 1; 1272 opts->time_offset = 0; 1273 break; 1274 case Opt_err_cont: 1275 opts->errors = FAT_ERRORS_CONT; 1276 break; 1277 case Opt_err_panic: 1278 opts->errors = FAT_ERRORS_PANIC; 1279 break; 1280 case Opt_err_ro: 1281 opts->errors = FAT_ERRORS_RO; 1282 break; 1283 case Opt_nfs_stale_rw: 1284 opts->nfs = FAT_NFS_STALE_RW; 1285 break; 1286 case Opt_nfs_nostale_ro: 1287 opts->nfs = FAT_NFS_NOSTALE_RO; 1288 break; 1289 case Opt_dos1xfloppy: 1290 opts->dos1xfloppy = 1; 1291 break; 1292 1293 /* msdos specific */ 1294 case Opt_dots: 1295 opts->dotsOK = 1; 1296 break; 1297 case Opt_nodots: 1298 opts->dotsOK = 0; 1299 break; 1300 1301 /* vfat specific */ 1302 case Opt_charset: 1303 fat_reset_iocharset(opts); 1304 iocharset = match_strdup(&args[0]); 1305 if (!iocharset) 1306 return -ENOMEM; 1307 opts->iocharset = iocharset; 1308 break; 1309 case Opt_shortname_lower: 1310 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1311 | VFAT_SFN_CREATE_WIN95; 1312 break; 1313 case Opt_shortname_win95: 1314 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1315 | VFAT_SFN_CREATE_WIN95; 1316 break; 1317 case Opt_shortname_winnt: 1318 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1319 | VFAT_SFN_CREATE_WINNT; 1320 break; 1321 case Opt_shortname_mixed: 1322 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1323 | VFAT_SFN_CREATE_WIN95; 1324 break; 1325 case Opt_utf8_no: /* 0 or no or false */ 1326 opts->utf8 = 0; 1327 break; 1328 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1329 opts->utf8 = 1; 1330 break; 1331 case Opt_uni_xl_no: /* 0 or no or false */ 1332 opts->unicode_xlate = 0; 1333 break; 1334 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1335 opts->unicode_xlate = 1; 1336 break; 1337 case Opt_nonumtail_no: /* 0 or no or false */ 1338 opts->numtail = 1; /* negated option */ 1339 break; 1340 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1341 opts->numtail = 0; /* negated option */ 1342 break; 1343 case Opt_rodir: 1344 opts->rodir = 1; 1345 break; 1346 case Opt_discard: 1347 opts->discard = 1; 1348 break; 1349 1350 /* obsolete mount options */ 1351 case Opt_obsolete: 1352 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1353 "not supported now", p); 1354 break; 1355 /* unknown option */ 1356 default: 1357 if (!silent) { 1358 fat_msg(sb, KERN_ERR, 1359 "Unrecognized mount option \"%s\" " 1360 "or missing value", p); 1361 } 1362 return -EINVAL; 1363 } 1364 } 1365 1366 out: 1367 /* UTF-8 doesn't provide FAT semantics */ 1368 if (!strcmp(opts->iocharset, "utf8")) { 1369 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1370 " for FAT filesystems, filesystem will be " 1371 "case sensitive!"); 1372 } 1373 1374 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1375 if (opts->allow_utime == (unsigned short)-1) 1376 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1377 if (opts->unicode_xlate) 1378 opts->utf8 = 0; 1379 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1380 sb->s_flags |= SB_RDONLY; 1381 sb->s_export_op = &fat_export_ops_nostale; 1382 } 1383 1384 return 0; 1385 } 1386 1387 static int fat_read_root(struct inode *inode) 1388 { 1389 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1390 int error; 1391 1392 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1393 inode->i_uid = sbi->options.fs_uid; 1394 inode->i_gid = sbi->options.fs_gid; 1395 inode_inc_iversion(inode); 1396 inode->i_generation = 0; 1397 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1398 inode->i_op = sbi->dir_ops; 1399 inode->i_fop = &fat_dir_operations; 1400 if (is_fat32(sbi)) { 1401 MSDOS_I(inode)->i_start = sbi->root_cluster; 1402 error = fat_calc_dir_size(inode); 1403 if (error < 0) 1404 return error; 1405 } else { 1406 MSDOS_I(inode)->i_start = 0; 1407 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1408 } 1409 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1410 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1411 MSDOS_I(inode)->i_logstart = 0; 1412 MSDOS_I(inode)->mmu_private = inode->i_size; 1413 1414 fat_save_attrs(inode, ATTR_DIR); 1415 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1416 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1417 set_nlink(inode, fat_subdirs(inode)+2); 1418 1419 return 0; 1420 } 1421 1422 static unsigned long calc_fat_clusters(struct super_block *sb) 1423 { 1424 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1425 1426 /* Divide first to avoid overflow */ 1427 if (!is_fat12(sbi)) { 1428 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1429 return ent_per_sec * sbi->fat_length; 1430 } 1431 1432 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1433 } 1434 1435 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1436 { 1437 if (get_unaligned_le16(&b->sector_size)) 1438 return false; 1439 if (b->sec_per_clus) 1440 return false; 1441 if (b->reserved) 1442 return false; 1443 if (b->fats) 1444 return false; 1445 if (get_unaligned_le16(&b->dir_entries)) 1446 return false; 1447 if (get_unaligned_le16(&b->sectors)) 1448 return false; 1449 if (b->media) 1450 return false; 1451 if (b->fat_length) 1452 return false; 1453 if (b->secs_track) 1454 return false; 1455 if (b->heads) 1456 return false; 1457 return true; 1458 } 1459 1460 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1461 int silent, struct fat_bios_param_block *bpb) 1462 { 1463 int error = -EINVAL; 1464 1465 /* Read in BPB ... */ 1466 memset(bpb, 0, sizeof(*bpb)); 1467 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1468 bpb->fat_sec_per_clus = b->sec_per_clus; 1469 bpb->fat_reserved = le16_to_cpu(b->reserved); 1470 bpb->fat_fats = b->fats; 1471 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1472 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1473 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1474 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1475 1476 bpb->fat16_state = b->fat16.state; 1477 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1478 1479 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1480 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1481 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1482 bpb->fat32_state = b->fat32.state; 1483 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1484 1485 /* Validate this looks like a FAT filesystem BPB */ 1486 if (!bpb->fat_reserved) { 1487 if (!silent) 1488 fat_msg(sb, KERN_ERR, 1489 "bogus number of reserved sectors"); 1490 goto out; 1491 } 1492 if (!bpb->fat_fats) { 1493 if (!silent) 1494 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1495 goto out; 1496 } 1497 1498 /* 1499 * Earlier we checked here that b->secs_track and b->head are nonzero, 1500 * but it turns out valid FAT filesystems can have zero there. 1501 */ 1502 1503 if (!fat_valid_media(b->media)) { 1504 if (!silent) 1505 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1506 (unsigned)b->media); 1507 goto out; 1508 } 1509 1510 if (!is_power_of_2(bpb->fat_sector_size) 1511 || (bpb->fat_sector_size < 512) 1512 || (bpb->fat_sector_size > 4096)) { 1513 if (!silent) 1514 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1515 (unsigned)bpb->fat_sector_size); 1516 goto out; 1517 } 1518 1519 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1520 if (!silent) 1521 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1522 (unsigned)bpb->fat_sec_per_clus); 1523 goto out; 1524 } 1525 1526 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1527 if (!silent) 1528 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1529 goto out; 1530 } 1531 1532 error = 0; 1533 1534 out: 1535 return error; 1536 } 1537 1538 static int fat_read_static_bpb(struct super_block *sb, 1539 struct fat_boot_sector *b, int silent, 1540 struct fat_bios_param_block *bpb) 1541 { 1542 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1543 sector_t bd_sects = bdev_nr_sectors(sb->s_bdev); 1544 struct fat_floppy_defaults *fdefaults = NULL; 1545 int error = -EINVAL; 1546 unsigned i; 1547 1548 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1549 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1550 if (!silent) 1551 fat_msg(sb, KERN_ERR, 1552 "%s; no bootstrapping code", notdos1x); 1553 goto out; 1554 } 1555 1556 /* 1557 * If any value in this region is non-zero, it isn't archaic 1558 * DOS. 1559 */ 1560 if (!fat_bpb_is_zero(b)) { 1561 if (!silent) 1562 fat_msg(sb, KERN_ERR, 1563 "%s; DOS 2.x BPB is non-zero", notdos1x); 1564 goto out; 1565 } 1566 1567 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1568 if (floppy_defaults[i].nr_sectors == bd_sects) { 1569 fdefaults = &floppy_defaults[i]; 1570 break; 1571 } 1572 } 1573 1574 if (fdefaults == NULL) { 1575 if (!silent) 1576 fat_msg(sb, KERN_WARNING, 1577 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1578 (u64)bd_sects); 1579 goto out; 1580 } 1581 1582 if (!silent) 1583 fat_msg(sb, KERN_INFO, 1584 "This looks like a DOS 1.x volume; assuming default BPB values"); 1585 1586 memset(bpb, 0, sizeof(*bpb)); 1587 bpb->fat_sector_size = SECTOR_SIZE; 1588 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1589 bpb->fat_reserved = 1; 1590 bpb->fat_fats = 2; 1591 bpb->fat_dir_entries = fdefaults->dir_entries; 1592 bpb->fat_sectors = fdefaults->nr_sectors; 1593 bpb->fat_fat_length = fdefaults->fat_length; 1594 1595 error = 0; 1596 1597 out: 1598 return error; 1599 } 1600 1601 /* 1602 * Read the super block of an MS-DOS FS. 1603 */ 1604 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1605 void (*setup)(struct super_block *)) 1606 { 1607 struct inode *root_inode = NULL, *fat_inode = NULL; 1608 struct inode *fsinfo_inode = NULL; 1609 struct buffer_head *bh; 1610 struct fat_bios_param_block bpb; 1611 struct msdos_sb_info *sbi; 1612 u16 logical_sector_size; 1613 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1614 int debug; 1615 long error; 1616 char buf[50]; 1617 struct timespec64 ts; 1618 1619 /* 1620 * GFP_KERNEL is ok here, because while we do hold the 1621 * superblock lock, memory pressure can't call back into 1622 * the filesystem, since we're only just about to mount 1623 * it and have no inodes etc active! 1624 */ 1625 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1626 if (!sbi) 1627 return -ENOMEM; 1628 sb->s_fs_info = sbi; 1629 1630 sb->s_flags |= SB_NODIRATIME; 1631 sb->s_magic = MSDOS_SUPER_MAGIC; 1632 sb->s_op = &fat_sops; 1633 sb->s_export_op = &fat_export_ops; 1634 /* 1635 * fat timestamps are complex and truncated by fat itself, so 1636 * we set 1 here to be fast 1637 */ 1638 sb->s_time_gran = 1; 1639 mutex_init(&sbi->nfs_build_inode_lock); 1640 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1641 DEFAULT_RATELIMIT_BURST); 1642 1643 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1644 if (error) 1645 goto out_fail; 1646 1647 setup(sb); /* flavour-specific stuff that needs options */ 1648 1649 error = -EIO; 1650 sb_min_blocksize(sb, 512); 1651 bh = sb_bread(sb, 0); 1652 if (bh == NULL) { 1653 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1654 goto out_fail; 1655 } 1656 1657 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1658 &bpb); 1659 if (error == -EINVAL && sbi->options.dos1xfloppy) 1660 error = fat_read_static_bpb(sb, 1661 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1662 brelse(bh); 1663 1664 if (error == -EINVAL) 1665 goto out_invalid; 1666 else if (error) 1667 goto out_fail; 1668 1669 logical_sector_size = bpb.fat_sector_size; 1670 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1671 1672 error = -EIO; 1673 if (logical_sector_size < sb->s_blocksize) { 1674 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1675 " (logical sector size = %u)", logical_sector_size); 1676 goto out_fail; 1677 } 1678 1679 if (logical_sector_size > sb->s_blocksize) { 1680 struct buffer_head *bh_resize; 1681 1682 if (!sb_set_blocksize(sb, logical_sector_size)) { 1683 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1684 logical_sector_size); 1685 goto out_fail; 1686 } 1687 1688 /* Verify that the larger boot sector is fully readable */ 1689 bh_resize = sb_bread(sb, 0); 1690 if (bh_resize == NULL) { 1691 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1692 " (logical sector size = %lu)", 1693 sb->s_blocksize); 1694 goto out_fail; 1695 } 1696 brelse(bh_resize); 1697 } 1698 1699 mutex_init(&sbi->s_lock); 1700 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1701 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1702 sbi->fats = bpb.fat_fats; 1703 sbi->fat_bits = 0; /* Don't know yet */ 1704 sbi->fat_start = bpb.fat_reserved; 1705 sbi->fat_length = bpb.fat_fat_length; 1706 sbi->root_cluster = 0; 1707 sbi->free_clusters = -1; /* Don't know yet */ 1708 sbi->free_clus_valid = 0; 1709 sbi->prev_free = FAT_START_ENT; 1710 sb->s_maxbytes = 0xffffffff; 1711 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1712 sb->s_time_min = ts.tv_sec; 1713 1714 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1715 cpu_to_le16(FAT_DATE_MAX), 0); 1716 sb->s_time_max = ts.tv_sec; 1717 1718 if (!sbi->fat_length && bpb.fat32_length) { 1719 struct fat_boot_fsinfo *fsinfo; 1720 struct buffer_head *fsinfo_bh; 1721 1722 /* Must be FAT32 */ 1723 sbi->fat_bits = 32; 1724 sbi->fat_length = bpb.fat32_length; 1725 sbi->root_cluster = bpb.fat32_root_cluster; 1726 1727 /* MC - if info_sector is 0, don't multiply by 0 */ 1728 sbi->fsinfo_sector = bpb.fat32_info_sector; 1729 if (sbi->fsinfo_sector == 0) 1730 sbi->fsinfo_sector = 1; 1731 1732 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1733 if (fsinfo_bh == NULL) { 1734 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1735 " (sector = %lu)", sbi->fsinfo_sector); 1736 goto out_fail; 1737 } 1738 1739 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1740 if (!IS_FSINFO(fsinfo)) { 1741 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1742 "0x%08x, 0x%08x (sector = %lu)", 1743 le32_to_cpu(fsinfo->signature1), 1744 le32_to_cpu(fsinfo->signature2), 1745 sbi->fsinfo_sector); 1746 } else { 1747 if (sbi->options.usefree) 1748 sbi->free_clus_valid = 1; 1749 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1750 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1751 } 1752 1753 brelse(fsinfo_bh); 1754 } 1755 1756 /* interpret volume ID as a little endian 32 bit integer */ 1757 if (is_fat32(sbi)) 1758 sbi->vol_id = bpb.fat32_vol_id; 1759 else /* fat 16 or 12 */ 1760 sbi->vol_id = bpb.fat16_vol_id; 1761 1762 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1763 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1764 1765 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1766 sbi->dir_entries = bpb.fat_dir_entries; 1767 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1768 if (!silent) 1769 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1770 " (%u)", sbi->dir_entries); 1771 goto out_invalid; 1772 } 1773 1774 rootdir_sectors = sbi->dir_entries 1775 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1776 sbi->data_start = sbi->dir_start + rootdir_sectors; 1777 total_sectors = bpb.fat_sectors; 1778 if (total_sectors == 0) 1779 total_sectors = bpb.fat_total_sect; 1780 1781 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1782 1783 if (!is_fat32(sbi)) 1784 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1785 1786 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1787 if (is_fat32(sbi)) 1788 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1789 else /* fat 16 or 12 */ 1790 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1791 1792 /* check that FAT table does not overflow */ 1793 fat_clusters = calc_fat_clusters(sb); 1794 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1795 if (total_clusters > max_fat(sb)) { 1796 if (!silent) 1797 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1798 total_clusters); 1799 goto out_invalid; 1800 } 1801 1802 sbi->max_cluster = total_clusters + FAT_START_ENT; 1803 /* check the free_clusters, it's not necessarily correct */ 1804 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1805 sbi->free_clusters = -1; 1806 /* check the prev_free, it's not necessarily correct */ 1807 sbi->prev_free %= sbi->max_cluster; 1808 if (sbi->prev_free < FAT_START_ENT) 1809 sbi->prev_free = FAT_START_ENT; 1810 1811 /* set up enough so that it can read an inode */ 1812 fat_hash_init(sb); 1813 dir_hash_init(sb); 1814 fat_ent_access_init(sb); 1815 1816 /* 1817 * The low byte of the first FAT entry must have the same value as 1818 * the media field of the boot sector. But in real world, too many 1819 * devices are writing wrong values. So, removed that validity check. 1820 * 1821 * The removed check compared the first FAT entry to a value dependent 1822 * on the media field like this: 1823 * == (0x0F00 | media), for FAT12 1824 * == (0XFF00 | media), for FAT16 1825 * == (0x0FFFFF | media), for FAT32 1826 */ 1827 1828 error = -EINVAL; 1829 sprintf(buf, "cp%d", sbi->options.codepage); 1830 sbi->nls_disk = load_nls(buf); 1831 if (!sbi->nls_disk) { 1832 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1833 goto out_fail; 1834 } 1835 1836 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1837 if (sbi->options.isvfat) { 1838 sbi->nls_io = load_nls(sbi->options.iocharset); 1839 if (!sbi->nls_io) { 1840 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1841 sbi->options.iocharset); 1842 goto out_fail; 1843 } 1844 } 1845 1846 error = -ENOMEM; 1847 fat_inode = new_inode(sb); 1848 if (!fat_inode) 1849 goto out_fail; 1850 sbi->fat_inode = fat_inode; 1851 1852 fsinfo_inode = new_inode(sb); 1853 if (!fsinfo_inode) 1854 goto out_fail; 1855 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1856 sbi->fsinfo_inode = fsinfo_inode; 1857 insert_inode_hash(fsinfo_inode); 1858 1859 root_inode = new_inode(sb); 1860 if (!root_inode) 1861 goto out_fail; 1862 root_inode->i_ino = MSDOS_ROOT_INO; 1863 inode_set_iversion(root_inode, 1); 1864 error = fat_read_root(root_inode); 1865 if (error < 0) { 1866 iput(root_inode); 1867 goto out_fail; 1868 } 1869 error = -ENOMEM; 1870 insert_inode_hash(root_inode); 1871 fat_attach(root_inode, 0); 1872 sb->s_root = d_make_root(root_inode); 1873 if (!sb->s_root) { 1874 fat_msg(sb, KERN_ERR, "get root inode failed"); 1875 goto out_fail; 1876 } 1877 1878 if (sbi->options.discard && !bdev_max_discard_sectors(sb->s_bdev)) 1879 fat_msg(sb, KERN_WARNING, 1880 "mounting with \"discard\" option, but the device does not support discard"); 1881 1882 fat_set_state(sb, 1, 0); 1883 return 0; 1884 1885 out_invalid: 1886 error = -EINVAL; 1887 if (!silent) 1888 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1889 1890 out_fail: 1891 iput(fsinfo_inode); 1892 iput(fat_inode); 1893 unload_nls(sbi->nls_io); 1894 unload_nls(sbi->nls_disk); 1895 fat_reset_iocharset(&sbi->options); 1896 sb->s_fs_info = NULL; 1897 kfree(sbi); 1898 return error; 1899 } 1900 1901 EXPORT_SYMBOL_GPL(fat_fill_super); 1902 1903 /* 1904 * helper function for fat_flush_inodes. This writes both the inode 1905 * and the file data blocks, waiting for in flight data blocks before 1906 * the start of the call. It does not wait for any io started 1907 * during the call 1908 */ 1909 static int writeback_inode(struct inode *inode) 1910 { 1911 1912 int ret; 1913 1914 /* if we used wait=1, sync_inode_metadata waits for the io for the 1915 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1916 * and filemap_fdatawrite is used for the data blocks 1917 */ 1918 ret = sync_inode_metadata(inode, 0); 1919 if (!ret) 1920 ret = filemap_fdatawrite(inode->i_mapping); 1921 return ret; 1922 } 1923 1924 /* 1925 * write data and metadata corresponding to i1 and i2. The io is 1926 * started but we do not wait for any of it to finish. 1927 * 1928 * filemap_flush is used for the block device, so if there is a dirty 1929 * page for a block already in flight, we will not wait and start the 1930 * io over again 1931 */ 1932 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1933 { 1934 int ret = 0; 1935 if (!MSDOS_SB(sb)->options.flush) 1936 return 0; 1937 if (i1) 1938 ret = writeback_inode(i1); 1939 if (!ret && i2) 1940 ret = writeback_inode(i2); 1941 if (!ret) 1942 ret = sync_blockdev_nowait(sb->s_bdev); 1943 return ret; 1944 } 1945 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1946 1947 static int __init init_fat_fs(void) 1948 { 1949 int err; 1950 1951 err = fat_cache_init(); 1952 if (err) 1953 return err; 1954 1955 err = fat_init_inodecache(); 1956 if (err) 1957 goto failed; 1958 1959 return 0; 1960 1961 failed: 1962 fat_cache_destroy(); 1963 return err; 1964 } 1965 1966 static void __exit exit_fat_fs(void) 1967 { 1968 fat_cache_destroy(); 1969 fat_destroy_inodecache(); 1970 } 1971 1972 module_init(init_fat_fs) 1973 module_exit(exit_fat_fs) 1974 1975 MODULE_LICENSE("GPL"); 1976