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_readpage(struct file *file, struct page *page) 209 { 210 return mpage_readpage(page, 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, unsigned flags, 230 struct page **pagep, void **fsdata) 231 { 232 int err; 233 234 *pagep = NULL; 235 err = cont_write_begin(file, mapping, pos, len, flags, 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 .readpage = fat_readpage, 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 if (sbi->options.isvfat) { 571 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 572 de->cdate, de->ctime_cs); 573 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 574 } else 575 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME); 576 577 return 0; 578 } 579 580 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 581 { 582 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 583 mutex_lock(&sbi->nfs_build_inode_lock); 584 } 585 586 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 587 { 588 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 589 mutex_unlock(&sbi->nfs_build_inode_lock); 590 } 591 592 struct inode *fat_build_inode(struct super_block *sb, 593 struct msdos_dir_entry *de, loff_t i_pos) 594 { 595 struct inode *inode; 596 int err; 597 598 fat_lock_build_inode(MSDOS_SB(sb)); 599 inode = fat_iget(sb, i_pos); 600 if (inode) 601 goto out; 602 inode = new_inode(sb); 603 if (!inode) { 604 inode = ERR_PTR(-ENOMEM); 605 goto out; 606 } 607 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 608 inode_set_iversion(inode, 1); 609 err = fat_fill_inode(inode, de); 610 if (err) { 611 iput(inode); 612 inode = ERR_PTR(err); 613 goto out; 614 } 615 fat_attach(inode, i_pos); 616 insert_inode_hash(inode); 617 out: 618 fat_unlock_build_inode(MSDOS_SB(sb)); 619 return inode; 620 } 621 622 EXPORT_SYMBOL_GPL(fat_build_inode); 623 624 static int __fat_write_inode(struct inode *inode, int wait); 625 626 static void fat_free_eofblocks(struct inode *inode) 627 { 628 /* Release unwritten fallocated blocks on inode eviction. */ 629 if ((inode->i_blocks << 9) > 630 round_up(MSDOS_I(inode)->mmu_private, 631 MSDOS_SB(inode->i_sb)->cluster_size)) { 632 int err; 633 634 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 635 /* Fallocate results in updating the i_start/iogstart 636 * for the zero byte file. So, make it return to 637 * original state during evict and commit it to avoid 638 * any corruption on the next access to the cluster 639 * chain for the file. 640 */ 641 err = __fat_write_inode(inode, inode_needs_sync(inode)); 642 if (err) { 643 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 644 "update on disk inode for unused " 645 "fallocated blocks, inode could be " 646 "corrupted. Please run fsck"); 647 } 648 649 } 650 } 651 652 static void fat_evict_inode(struct inode *inode) 653 { 654 truncate_inode_pages_final(&inode->i_data); 655 if (!inode->i_nlink) { 656 inode->i_size = 0; 657 fat_truncate_blocks(inode, 0); 658 } else 659 fat_free_eofblocks(inode); 660 661 invalidate_inode_buffers(inode); 662 clear_inode(inode); 663 fat_cache_inval_inode(inode); 664 fat_detach(inode); 665 } 666 667 static void fat_set_state(struct super_block *sb, 668 unsigned int set, unsigned int force) 669 { 670 struct buffer_head *bh; 671 struct fat_boot_sector *b; 672 struct msdos_sb_info *sbi = MSDOS_SB(sb); 673 674 /* do not change any thing if mounted read only */ 675 if (sb_rdonly(sb) && !force) 676 return; 677 678 /* do not change state if fs was dirty */ 679 if (sbi->dirty) { 680 /* warn only on set (mount). */ 681 if (set) 682 fat_msg(sb, KERN_WARNING, "Volume was not properly " 683 "unmounted. Some data may be corrupt. " 684 "Please run fsck."); 685 return; 686 } 687 688 bh = sb_bread(sb, 0); 689 if (bh == NULL) { 690 fat_msg(sb, KERN_ERR, "unable to read boot sector " 691 "to mark fs as dirty"); 692 return; 693 } 694 695 b = (struct fat_boot_sector *) bh->b_data; 696 697 if (is_fat32(sbi)) { 698 if (set) 699 b->fat32.state |= FAT_STATE_DIRTY; 700 else 701 b->fat32.state &= ~FAT_STATE_DIRTY; 702 } else /* fat 16 and 12 */ { 703 if (set) 704 b->fat16.state |= FAT_STATE_DIRTY; 705 else 706 b->fat16.state &= ~FAT_STATE_DIRTY; 707 } 708 709 mark_buffer_dirty(bh); 710 sync_dirty_buffer(bh); 711 brelse(bh); 712 } 713 714 static void fat_reset_iocharset(struct fat_mount_options *opts) 715 { 716 if (opts->iocharset != fat_default_iocharset) { 717 /* Note: opts->iocharset can be NULL here */ 718 kfree(opts->iocharset); 719 opts->iocharset = fat_default_iocharset; 720 } 721 } 722 723 static void delayed_free(struct rcu_head *p) 724 { 725 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 726 unload_nls(sbi->nls_disk); 727 unload_nls(sbi->nls_io); 728 fat_reset_iocharset(&sbi->options); 729 kfree(sbi); 730 } 731 732 static void fat_put_super(struct super_block *sb) 733 { 734 struct msdos_sb_info *sbi = MSDOS_SB(sb); 735 736 fat_set_state(sb, 0, 0); 737 738 iput(sbi->fsinfo_inode); 739 iput(sbi->fat_inode); 740 741 call_rcu(&sbi->rcu, delayed_free); 742 } 743 744 static struct kmem_cache *fat_inode_cachep; 745 746 static struct inode *fat_alloc_inode(struct super_block *sb) 747 { 748 struct msdos_inode_info *ei; 749 ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS); 750 if (!ei) 751 return NULL; 752 753 init_rwsem(&ei->truncate_lock); 754 /* Zeroing to allow iput() even if partial initialized inode. */ 755 ei->mmu_private = 0; 756 ei->i_start = 0; 757 ei->i_logstart = 0; 758 ei->i_attrs = 0; 759 ei->i_pos = 0; 760 761 return &ei->vfs_inode; 762 } 763 764 static void fat_free_inode(struct inode *inode) 765 { 766 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 767 } 768 769 static void init_once(void *foo) 770 { 771 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 772 773 spin_lock_init(&ei->cache_lru_lock); 774 ei->nr_caches = 0; 775 ei->cache_valid_id = FAT_CACHE_VALID + 1; 776 INIT_LIST_HEAD(&ei->cache_lru); 777 INIT_HLIST_NODE(&ei->i_fat_hash); 778 INIT_HLIST_NODE(&ei->i_dir_hash); 779 inode_init_once(&ei->vfs_inode); 780 } 781 782 static int __init fat_init_inodecache(void) 783 { 784 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 785 sizeof(struct msdos_inode_info), 786 0, (SLAB_RECLAIM_ACCOUNT| 787 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 788 init_once); 789 if (fat_inode_cachep == NULL) 790 return -ENOMEM; 791 return 0; 792 } 793 794 static void __exit fat_destroy_inodecache(void) 795 { 796 /* 797 * Make sure all delayed rcu free inodes are flushed before we 798 * destroy cache. 799 */ 800 rcu_barrier(); 801 kmem_cache_destroy(fat_inode_cachep); 802 } 803 804 static int fat_remount(struct super_block *sb, int *flags, char *data) 805 { 806 bool new_rdonly; 807 struct msdos_sb_info *sbi = MSDOS_SB(sb); 808 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 809 810 sync_filesystem(sb); 811 812 /* make sure we update state on remount. */ 813 new_rdonly = *flags & SB_RDONLY; 814 if (new_rdonly != sb_rdonly(sb)) { 815 if (new_rdonly) 816 fat_set_state(sb, 0, 0); 817 else 818 fat_set_state(sb, 1, 1); 819 } 820 return 0; 821 } 822 823 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 824 { 825 struct super_block *sb = dentry->d_sb; 826 struct msdos_sb_info *sbi = MSDOS_SB(sb); 827 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 828 829 /* If the count of free cluster is still unknown, counts it here. */ 830 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 831 int err = fat_count_free_clusters(dentry->d_sb); 832 if (err) 833 return err; 834 } 835 836 buf->f_type = dentry->d_sb->s_magic; 837 buf->f_bsize = sbi->cluster_size; 838 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 839 buf->f_bfree = sbi->free_clusters; 840 buf->f_bavail = sbi->free_clusters; 841 buf->f_fsid = u64_to_fsid(id); 842 buf->f_namelen = 843 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 844 845 return 0; 846 } 847 848 static int __fat_write_inode(struct inode *inode, int wait) 849 { 850 struct super_block *sb = inode->i_sb; 851 struct msdos_sb_info *sbi = MSDOS_SB(sb); 852 struct buffer_head *bh; 853 struct msdos_dir_entry *raw_entry; 854 loff_t i_pos; 855 sector_t blocknr; 856 int err, offset; 857 858 if (inode->i_ino == MSDOS_ROOT_INO) 859 return 0; 860 861 retry: 862 i_pos = fat_i_pos_read(sbi, inode); 863 if (!i_pos) 864 return 0; 865 866 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 867 bh = sb_bread(sb, blocknr); 868 if (!bh) { 869 fat_msg(sb, KERN_ERR, "unable to read inode block " 870 "for updating (i_pos %lld)", i_pos); 871 return -EIO; 872 } 873 spin_lock(&sbi->inode_hash_lock); 874 if (i_pos != MSDOS_I(inode)->i_pos) { 875 spin_unlock(&sbi->inode_hash_lock); 876 brelse(bh); 877 goto retry; 878 } 879 880 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 881 if (S_ISDIR(inode->i_mode)) 882 raw_entry->size = 0; 883 else 884 raw_entry->size = cpu_to_le32(inode->i_size); 885 raw_entry->attr = fat_make_attrs(inode); 886 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 887 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 888 &raw_entry->date, NULL); 889 if (sbi->options.isvfat) { 890 __le16 atime; 891 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 892 &raw_entry->cdate, &raw_entry->ctime_cs); 893 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 894 &raw_entry->adate, NULL); 895 } 896 spin_unlock(&sbi->inode_hash_lock); 897 mark_buffer_dirty(bh); 898 err = 0; 899 if (wait) 900 err = sync_dirty_buffer(bh); 901 brelse(bh); 902 return err; 903 } 904 905 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 906 { 907 int err; 908 909 if (inode->i_ino == MSDOS_FSINFO_INO) { 910 struct super_block *sb = inode->i_sb; 911 912 mutex_lock(&MSDOS_SB(sb)->s_lock); 913 err = fat_clusters_flush(sb); 914 mutex_unlock(&MSDOS_SB(sb)->s_lock); 915 } else 916 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 917 918 return err; 919 } 920 921 int fat_sync_inode(struct inode *inode) 922 { 923 return __fat_write_inode(inode, 1); 924 } 925 926 EXPORT_SYMBOL_GPL(fat_sync_inode); 927 928 static int fat_show_options(struct seq_file *m, struct dentry *root); 929 static const struct super_operations fat_sops = { 930 .alloc_inode = fat_alloc_inode, 931 .free_inode = fat_free_inode, 932 .write_inode = fat_write_inode, 933 .evict_inode = fat_evict_inode, 934 .put_super = fat_put_super, 935 .statfs = fat_statfs, 936 .remount_fs = fat_remount, 937 938 .show_options = fat_show_options, 939 }; 940 941 static int fat_show_options(struct seq_file *m, struct dentry *root) 942 { 943 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 944 struct fat_mount_options *opts = &sbi->options; 945 int isvfat = opts->isvfat; 946 947 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 948 seq_printf(m, ",uid=%u", 949 from_kuid_munged(&init_user_ns, opts->fs_uid)); 950 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 951 seq_printf(m, ",gid=%u", 952 from_kgid_munged(&init_user_ns, opts->fs_gid)); 953 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 954 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 955 if (opts->allow_utime) 956 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 957 if (sbi->nls_disk) 958 /* strip "cp" prefix from displayed option */ 959 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 960 if (isvfat) { 961 if (sbi->nls_io) 962 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 963 964 switch (opts->shortname) { 965 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 966 seq_puts(m, ",shortname=win95"); 967 break; 968 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 969 seq_puts(m, ",shortname=winnt"); 970 break; 971 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 972 seq_puts(m, ",shortname=mixed"); 973 break; 974 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 975 seq_puts(m, ",shortname=lower"); 976 break; 977 default: 978 seq_puts(m, ",shortname=unknown"); 979 break; 980 } 981 } 982 if (opts->name_check != 'n') 983 seq_printf(m, ",check=%c", opts->name_check); 984 if (opts->usefree) 985 seq_puts(m, ",usefree"); 986 if (opts->quiet) 987 seq_puts(m, ",quiet"); 988 if (opts->showexec) 989 seq_puts(m, ",showexec"); 990 if (opts->sys_immutable) 991 seq_puts(m, ",sys_immutable"); 992 if (!isvfat) { 993 if (opts->dotsOK) 994 seq_puts(m, ",dotsOK=yes"); 995 if (opts->nocase) 996 seq_puts(m, ",nocase"); 997 } else { 998 if (opts->utf8) 999 seq_puts(m, ",utf8"); 1000 if (opts->unicode_xlate) 1001 seq_puts(m, ",uni_xlate"); 1002 if (!opts->numtail) 1003 seq_puts(m, ",nonumtail"); 1004 if (opts->rodir) 1005 seq_puts(m, ",rodir"); 1006 } 1007 if (opts->flush) 1008 seq_puts(m, ",flush"); 1009 if (opts->tz_set) { 1010 if (opts->time_offset) 1011 seq_printf(m, ",time_offset=%d", opts->time_offset); 1012 else 1013 seq_puts(m, ",tz=UTC"); 1014 } 1015 if (opts->errors == FAT_ERRORS_CONT) 1016 seq_puts(m, ",errors=continue"); 1017 else if (opts->errors == FAT_ERRORS_PANIC) 1018 seq_puts(m, ",errors=panic"); 1019 else 1020 seq_puts(m, ",errors=remount-ro"); 1021 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1022 seq_puts(m, ",nfs=nostale_ro"); 1023 else if (opts->nfs) 1024 seq_puts(m, ",nfs=stale_rw"); 1025 if (opts->discard) 1026 seq_puts(m, ",discard"); 1027 if (opts->dos1xfloppy) 1028 seq_puts(m, ",dos1xfloppy"); 1029 1030 return 0; 1031 } 1032 1033 enum { 1034 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1035 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1036 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1037 Opt_immutable, Opt_dots, Opt_nodots, 1038 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1039 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1040 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1041 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1042 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1043 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1044 }; 1045 1046 static const match_table_t fat_tokens = { 1047 {Opt_check_r, "check=relaxed"}, 1048 {Opt_check_s, "check=strict"}, 1049 {Opt_check_n, "check=normal"}, 1050 {Opt_check_r, "check=r"}, 1051 {Opt_check_s, "check=s"}, 1052 {Opt_check_n, "check=n"}, 1053 {Opt_uid, "uid=%u"}, 1054 {Opt_gid, "gid=%u"}, 1055 {Opt_umask, "umask=%o"}, 1056 {Opt_dmask, "dmask=%o"}, 1057 {Opt_fmask, "fmask=%o"}, 1058 {Opt_allow_utime, "allow_utime=%o"}, 1059 {Opt_codepage, "codepage=%u"}, 1060 {Opt_usefree, "usefree"}, 1061 {Opt_nocase, "nocase"}, 1062 {Opt_quiet, "quiet"}, 1063 {Opt_showexec, "showexec"}, 1064 {Opt_debug, "debug"}, 1065 {Opt_immutable, "sys_immutable"}, 1066 {Opt_flush, "flush"}, 1067 {Opt_tz_utc, "tz=UTC"}, 1068 {Opt_time_offset, "time_offset=%d"}, 1069 {Opt_err_cont, "errors=continue"}, 1070 {Opt_err_panic, "errors=panic"}, 1071 {Opt_err_ro, "errors=remount-ro"}, 1072 {Opt_discard, "discard"}, 1073 {Opt_nfs_stale_rw, "nfs"}, 1074 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1075 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1076 {Opt_dos1xfloppy, "dos1xfloppy"}, 1077 {Opt_obsolete, "conv=binary"}, 1078 {Opt_obsolete, "conv=text"}, 1079 {Opt_obsolete, "conv=auto"}, 1080 {Opt_obsolete, "conv=b"}, 1081 {Opt_obsolete, "conv=t"}, 1082 {Opt_obsolete, "conv=a"}, 1083 {Opt_obsolete, "fat=%u"}, 1084 {Opt_obsolete, "blocksize=%u"}, 1085 {Opt_obsolete, "cvf_format=%20s"}, 1086 {Opt_obsolete, "cvf_options=%100s"}, 1087 {Opt_obsolete, "posix"}, 1088 {Opt_err, NULL}, 1089 }; 1090 static const match_table_t msdos_tokens = { 1091 {Opt_nodots, "nodots"}, 1092 {Opt_nodots, "dotsOK=no"}, 1093 {Opt_dots, "dots"}, 1094 {Opt_dots, "dotsOK=yes"}, 1095 {Opt_err, NULL} 1096 }; 1097 static const match_table_t vfat_tokens = { 1098 {Opt_charset, "iocharset=%s"}, 1099 {Opt_shortname_lower, "shortname=lower"}, 1100 {Opt_shortname_win95, "shortname=win95"}, 1101 {Opt_shortname_winnt, "shortname=winnt"}, 1102 {Opt_shortname_mixed, "shortname=mixed"}, 1103 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1104 {Opt_utf8_no, "utf8=no"}, 1105 {Opt_utf8_no, "utf8=false"}, 1106 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1107 {Opt_utf8_yes, "utf8=yes"}, 1108 {Opt_utf8_yes, "utf8=true"}, 1109 {Opt_utf8_yes, "utf8"}, 1110 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1111 {Opt_uni_xl_no, "uni_xlate=no"}, 1112 {Opt_uni_xl_no, "uni_xlate=false"}, 1113 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1114 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1115 {Opt_uni_xl_yes, "uni_xlate=true"}, 1116 {Opt_uni_xl_yes, "uni_xlate"}, 1117 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1118 {Opt_nonumtail_no, "nonumtail=no"}, 1119 {Opt_nonumtail_no, "nonumtail=false"}, 1120 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1121 {Opt_nonumtail_yes, "nonumtail=yes"}, 1122 {Opt_nonumtail_yes, "nonumtail=true"}, 1123 {Opt_nonumtail_yes, "nonumtail"}, 1124 {Opt_rodir, "rodir"}, 1125 {Opt_err, NULL} 1126 }; 1127 1128 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1129 int silent, int *debug, struct fat_mount_options *opts) 1130 { 1131 char *p; 1132 substring_t args[MAX_OPT_ARGS]; 1133 int option; 1134 char *iocharset; 1135 1136 opts->isvfat = is_vfat; 1137 1138 opts->fs_uid = current_uid(); 1139 opts->fs_gid = current_gid(); 1140 opts->fs_fmask = opts->fs_dmask = current_umask(); 1141 opts->allow_utime = -1; 1142 opts->codepage = fat_default_codepage; 1143 fat_reset_iocharset(opts); 1144 if (is_vfat) { 1145 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1146 opts->rodir = 0; 1147 } else { 1148 opts->shortname = 0; 1149 opts->rodir = 1; 1150 } 1151 opts->name_check = 'n'; 1152 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1153 opts->unicode_xlate = 0; 1154 opts->numtail = 1; 1155 opts->usefree = opts->nocase = 0; 1156 opts->tz_set = 0; 1157 opts->nfs = 0; 1158 opts->errors = FAT_ERRORS_RO; 1159 *debug = 0; 1160 1161 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1162 1163 if (!options) 1164 goto out; 1165 1166 while ((p = strsep(&options, ",")) != NULL) { 1167 int token; 1168 if (!*p) 1169 continue; 1170 1171 token = match_token(p, fat_tokens, args); 1172 if (token == Opt_err) { 1173 if (is_vfat) 1174 token = match_token(p, vfat_tokens, args); 1175 else 1176 token = match_token(p, msdos_tokens, args); 1177 } 1178 switch (token) { 1179 case Opt_check_s: 1180 opts->name_check = 's'; 1181 break; 1182 case Opt_check_r: 1183 opts->name_check = 'r'; 1184 break; 1185 case Opt_check_n: 1186 opts->name_check = 'n'; 1187 break; 1188 case Opt_usefree: 1189 opts->usefree = 1; 1190 break; 1191 case Opt_nocase: 1192 if (!is_vfat) 1193 opts->nocase = 1; 1194 else { 1195 /* for backward compatibility */ 1196 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1197 | VFAT_SFN_CREATE_WIN95; 1198 } 1199 break; 1200 case Opt_quiet: 1201 opts->quiet = 1; 1202 break; 1203 case Opt_showexec: 1204 opts->showexec = 1; 1205 break; 1206 case Opt_debug: 1207 *debug = 1; 1208 break; 1209 case Opt_immutable: 1210 opts->sys_immutable = 1; 1211 break; 1212 case Opt_uid: 1213 if (match_int(&args[0], &option)) 1214 return -EINVAL; 1215 opts->fs_uid = make_kuid(current_user_ns(), option); 1216 if (!uid_valid(opts->fs_uid)) 1217 return -EINVAL; 1218 break; 1219 case Opt_gid: 1220 if (match_int(&args[0], &option)) 1221 return -EINVAL; 1222 opts->fs_gid = make_kgid(current_user_ns(), option); 1223 if (!gid_valid(opts->fs_gid)) 1224 return -EINVAL; 1225 break; 1226 case Opt_umask: 1227 if (match_octal(&args[0], &option)) 1228 return -EINVAL; 1229 opts->fs_fmask = opts->fs_dmask = option; 1230 break; 1231 case Opt_dmask: 1232 if (match_octal(&args[0], &option)) 1233 return -EINVAL; 1234 opts->fs_dmask = option; 1235 break; 1236 case Opt_fmask: 1237 if (match_octal(&args[0], &option)) 1238 return -EINVAL; 1239 opts->fs_fmask = option; 1240 break; 1241 case Opt_allow_utime: 1242 if (match_octal(&args[0], &option)) 1243 return -EINVAL; 1244 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1245 break; 1246 case Opt_codepage: 1247 if (match_int(&args[0], &option)) 1248 return -EINVAL; 1249 opts->codepage = option; 1250 break; 1251 case Opt_flush: 1252 opts->flush = 1; 1253 break; 1254 case Opt_time_offset: 1255 if (match_int(&args[0], &option)) 1256 return -EINVAL; 1257 /* 1258 * GMT+-12 zones may have DST corrections so at least 1259 * 13 hours difference is needed. Make the limit 24 1260 * just in case someone invents something unusual. 1261 */ 1262 if (option < -24 * 60 || option > 24 * 60) 1263 return -EINVAL; 1264 opts->tz_set = 1; 1265 opts->time_offset = option; 1266 break; 1267 case Opt_tz_utc: 1268 opts->tz_set = 1; 1269 opts->time_offset = 0; 1270 break; 1271 case Opt_err_cont: 1272 opts->errors = FAT_ERRORS_CONT; 1273 break; 1274 case Opt_err_panic: 1275 opts->errors = FAT_ERRORS_PANIC; 1276 break; 1277 case Opt_err_ro: 1278 opts->errors = FAT_ERRORS_RO; 1279 break; 1280 case Opt_nfs_stale_rw: 1281 opts->nfs = FAT_NFS_STALE_RW; 1282 break; 1283 case Opt_nfs_nostale_ro: 1284 opts->nfs = FAT_NFS_NOSTALE_RO; 1285 break; 1286 case Opt_dos1xfloppy: 1287 opts->dos1xfloppy = 1; 1288 break; 1289 1290 /* msdos specific */ 1291 case Opt_dots: 1292 opts->dotsOK = 1; 1293 break; 1294 case Opt_nodots: 1295 opts->dotsOK = 0; 1296 break; 1297 1298 /* vfat specific */ 1299 case Opt_charset: 1300 fat_reset_iocharset(opts); 1301 iocharset = match_strdup(&args[0]); 1302 if (!iocharset) 1303 return -ENOMEM; 1304 opts->iocharset = iocharset; 1305 break; 1306 case Opt_shortname_lower: 1307 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1308 | VFAT_SFN_CREATE_WIN95; 1309 break; 1310 case Opt_shortname_win95: 1311 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1312 | VFAT_SFN_CREATE_WIN95; 1313 break; 1314 case Opt_shortname_winnt: 1315 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1316 | VFAT_SFN_CREATE_WINNT; 1317 break; 1318 case Opt_shortname_mixed: 1319 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1320 | VFAT_SFN_CREATE_WIN95; 1321 break; 1322 case Opt_utf8_no: /* 0 or no or false */ 1323 opts->utf8 = 0; 1324 break; 1325 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1326 opts->utf8 = 1; 1327 break; 1328 case Opt_uni_xl_no: /* 0 or no or false */ 1329 opts->unicode_xlate = 0; 1330 break; 1331 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1332 opts->unicode_xlate = 1; 1333 break; 1334 case Opt_nonumtail_no: /* 0 or no or false */ 1335 opts->numtail = 1; /* negated option */ 1336 break; 1337 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1338 opts->numtail = 0; /* negated option */ 1339 break; 1340 case Opt_rodir: 1341 opts->rodir = 1; 1342 break; 1343 case Opt_discard: 1344 opts->discard = 1; 1345 break; 1346 1347 /* obsolete mount options */ 1348 case Opt_obsolete: 1349 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1350 "not supported now", p); 1351 break; 1352 /* unknown option */ 1353 default: 1354 if (!silent) { 1355 fat_msg(sb, KERN_ERR, 1356 "Unrecognized mount option \"%s\" " 1357 "or missing value", p); 1358 } 1359 return -EINVAL; 1360 } 1361 } 1362 1363 out: 1364 /* UTF-8 doesn't provide FAT semantics */ 1365 if (!strcmp(opts->iocharset, "utf8")) { 1366 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1367 " for FAT filesystems, filesystem will be " 1368 "case sensitive!"); 1369 } 1370 1371 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1372 if (opts->allow_utime == (unsigned short)-1) 1373 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1374 if (opts->unicode_xlate) 1375 opts->utf8 = 0; 1376 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1377 sb->s_flags |= SB_RDONLY; 1378 sb->s_export_op = &fat_export_ops_nostale; 1379 } 1380 1381 return 0; 1382 } 1383 1384 static int fat_read_root(struct inode *inode) 1385 { 1386 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1387 int error; 1388 1389 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1390 inode->i_uid = sbi->options.fs_uid; 1391 inode->i_gid = sbi->options.fs_gid; 1392 inode_inc_iversion(inode); 1393 inode->i_generation = 0; 1394 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1395 inode->i_op = sbi->dir_ops; 1396 inode->i_fop = &fat_dir_operations; 1397 if (is_fat32(sbi)) { 1398 MSDOS_I(inode)->i_start = sbi->root_cluster; 1399 error = fat_calc_dir_size(inode); 1400 if (error < 0) 1401 return error; 1402 } else { 1403 MSDOS_I(inode)->i_start = 0; 1404 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1405 } 1406 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1407 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1408 MSDOS_I(inode)->i_logstart = 0; 1409 MSDOS_I(inode)->mmu_private = inode->i_size; 1410 1411 fat_save_attrs(inode, ATTR_DIR); 1412 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1413 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1414 set_nlink(inode, fat_subdirs(inode)+2); 1415 1416 return 0; 1417 } 1418 1419 static unsigned long calc_fat_clusters(struct super_block *sb) 1420 { 1421 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1422 1423 /* Divide first to avoid overflow */ 1424 if (!is_fat12(sbi)) { 1425 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1426 return ent_per_sec * sbi->fat_length; 1427 } 1428 1429 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1430 } 1431 1432 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1433 { 1434 if (get_unaligned_le16(&b->sector_size)) 1435 return false; 1436 if (b->sec_per_clus) 1437 return false; 1438 if (b->reserved) 1439 return false; 1440 if (b->fats) 1441 return false; 1442 if (get_unaligned_le16(&b->dir_entries)) 1443 return false; 1444 if (get_unaligned_le16(&b->sectors)) 1445 return false; 1446 if (b->media) 1447 return false; 1448 if (b->fat_length) 1449 return false; 1450 if (b->secs_track) 1451 return false; 1452 if (b->heads) 1453 return false; 1454 return true; 1455 } 1456 1457 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1458 int silent, struct fat_bios_param_block *bpb) 1459 { 1460 int error = -EINVAL; 1461 1462 /* Read in BPB ... */ 1463 memset(bpb, 0, sizeof(*bpb)); 1464 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1465 bpb->fat_sec_per_clus = b->sec_per_clus; 1466 bpb->fat_reserved = le16_to_cpu(b->reserved); 1467 bpb->fat_fats = b->fats; 1468 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1469 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1470 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1471 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1472 1473 bpb->fat16_state = b->fat16.state; 1474 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1475 1476 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1477 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1478 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1479 bpb->fat32_state = b->fat32.state; 1480 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1481 1482 /* Validate this looks like a FAT filesystem BPB */ 1483 if (!bpb->fat_reserved) { 1484 if (!silent) 1485 fat_msg(sb, KERN_ERR, 1486 "bogus number of reserved sectors"); 1487 goto out; 1488 } 1489 if (!bpb->fat_fats) { 1490 if (!silent) 1491 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1492 goto out; 1493 } 1494 1495 /* 1496 * Earlier we checked here that b->secs_track and b->head are nonzero, 1497 * but it turns out valid FAT filesystems can have zero there. 1498 */ 1499 1500 if (!fat_valid_media(b->media)) { 1501 if (!silent) 1502 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1503 (unsigned)b->media); 1504 goto out; 1505 } 1506 1507 if (!is_power_of_2(bpb->fat_sector_size) 1508 || (bpb->fat_sector_size < 512) 1509 || (bpb->fat_sector_size > 4096)) { 1510 if (!silent) 1511 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1512 (unsigned)bpb->fat_sector_size); 1513 goto out; 1514 } 1515 1516 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1517 if (!silent) 1518 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1519 (unsigned)bpb->fat_sec_per_clus); 1520 goto out; 1521 } 1522 1523 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1524 if (!silent) 1525 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1526 goto out; 1527 } 1528 1529 error = 0; 1530 1531 out: 1532 return error; 1533 } 1534 1535 static int fat_read_static_bpb(struct super_block *sb, 1536 struct fat_boot_sector *b, int silent, 1537 struct fat_bios_param_block *bpb) 1538 { 1539 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1540 sector_t bd_sects = bdev_nr_sectors(sb->s_bdev); 1541 struct fat_floppy_defaults *fdefaults = NULL; 1542 int error = -EINVAL; 1543 unsigned i; 1544 1545 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1546 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1547 if (!silent) 1548 fat_msg(sb, KERN_ERR, 1549 "%s; no bootstrapping code", notdos1x); 1550 goto out; 1551 } 1552 1553 /* 1554 * If any value in this region is non-zero, it isn't archaic 1555 * DOS. 1556 */ 1557 if (!fat_bpb_is_zero(b)) { 1558 if (!silent) 1559 fat_msg(sb, KERN_ERR, 1560 "%s; DOS 2.x BPB is non-zero", notdos1x); 1561 goto out; 1562 } 1563 1564 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1565 if (floppy_defaults[i].nr_sectors == bd_sects) { 1566 fdefaults = &floppy_defaults[i]; 1567 break; 1568 } 1569 } 1570 1571 if (fdefaults == NULL) { 1572 if (!silent) 1573 fat_msg(sb, KERN_WARNING, 1574 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1575 (u64)bd_sects); 1576 goto out; 1577 } 1578 1579 if (!silent) 1580 fat_msg(sb, KERN_INFO, 1581 "This looks like a DOS 1.x volume; assuming default BPB values"); 1582 1583 memset(bpb, 0, sizeof(*bpb)); 1584 bpb->fat_sector_size = SECTOR_SIZE; 1585 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1586 bpb->fat_reserved = 1; 1587 bpb->fat_fats = 2; 1588 bpb->fat_dir_entries = fdefaults->dir_entries; 1589 bpb->fat_sectors = fdefaults->nr_sectors; 1590 bpb->fat_fat_length = fdefaults->fat_length; 1591 1592 error = 0; 1593 1594 out: 1595 return error; 1596 } 1597 1598 /* 1599 * Read the super block of an MS-DOS FS. 1600 */ 1601 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1602 void (*setup)(struct super_block *)) 1603 { 1604 struct inode *root_inode = NULL, *fat_inode = NULL; 1605 struct inode *fsinfo_inode = NULL; 1606 struct buffer_head *bh; 1607 struct fat_bios_param_block bpb; 1608 struct msdos_sb_info *sbi; 1609 u16 logical_sector_size; 1610 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1611 int debug; 1612 long error; 1613 char buf[50]; 1614 struct timespec64 ts; 1615 1616 /* 1617 * GFP_KERNEL is ok here, because while we do hold the 1618 * superblock lock, memory pressure can't call back into 1619 * the filesystem, since we're only just about to mount 1620 * it and have no inodes etc active! 1621 */ 1622 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1623 if (!sbi) 1624 return -ENOMEM; 1625 sb->s_fs_info = sbi; 1626 1627 sb->s_flags |= SB_NODIRATIME; 1628 sb->s_magic = MSDOS_SUPER_MAGIC; 1629 sb->s_op = &fat_sops; 1630 sb->s_export_op = &fat_export_ops; 1631 /* 1632 * fat timestamps are complex and truncated by fat itself, so 1633 * we set 1 here to be fast 1634 */ 1635 sb->s_time_gran = 1; 1636 mutex_init(&sbi->nfs_build_inode_lock); 1637 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1638 DEFAULT_RATELIMIT_BURST); 1639 1640 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1641 if (error) 1642 goto out_fail; 1643 1644 setup(sb); /* flavour-specific stuff that needs options */ 1645 1646 error = -EIO; 1647 sb_min_blocksize(sb, 512); 1648 bh = sb_bread(sb, 0); 1649 if (bh == NULL) { 1650 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1651 goto out_fail; 1652 } 1653 1654 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1655 &bpb); 1656 if (error == -EINVAL && sbi->options.dos1xfloppy) 1657 error = fat_read_static_bpb(sb, 1658 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1659 brelse(bh); 1660 1661 if (error == -EINVAL) 1662 goto out_invalid; 1663 else if (error) 1664 goto out_fail; 1665 1666 logical_sector_size = bpb.fat_sector_size; 1667 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1668 1669 error = -EIO; 1670 if (logical_sector_size < sb->s_blocksize) { 1671 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1672 " (logical sector size = %u)", logical_sector_size); 1673 goto out_fail; 1674 } 1675 1676 if (logical_sector_size > sb->s_blocksize) { 1677 struct buffer_head *bh_resize; 1678 1679 if (!sb_set_blocksize(sb, logical_sector_size)) { 1680 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1681 logical_sector_size); 1682 goto out_fail; 1683 } 1684 1685 /* Verify that the larger boot sector is fully readable */ 1686 bh_resize = sb_bread(sb, 0); 1687 if (bh_resize == NULL) { 1688 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1689 " (logical sector size = %lu)", 1690 sb->s_blocksize); 1691 goto out_fail; 1692 } 1693 brelse(bh_resize); 1694 } 1695 1696 mutex_init(&sbi->s_lock); 1697 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1698 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1699 sbi->fats = bpb.fat_fats; 1700 sbi->fat_bits = 0; /* Don't know yet */ 1701 sbi->fat_start = bpb.fat_reserved; 1702 sbi->fat_length = bpb.fat_fat_length; 1703 sbi->root_cluster = 0; 1704 sbi->free_clusters = -1; /* Don't know yet */ 1705 sbi->free_clus_valid = 0; 1706 sbi->prev_free = FAT_START_ENT; 1707 sb->s_maxbytes = 0xffffffff; 1708 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1709 sb->s_time_min = ts.tv_sec; 1710 1711 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1712 cpu_to_le16(FAT_DATE_MAX), 0); 1713 sb->s_time_max = ts.tv_sec; 1714 1715 if (!sbi->fat_length && bpb.fat32_length) { 1716 struct fat_boot_fsinfo *fsinfo; 1717 struct buffer_head *fsinfo_bh; 1718 1719 /* Must be FAT32 */ 1720 sbi->fat_bits = 32; 1721 sbi->fat_length = bpb.fat32_length; 1722 sbi->root_cluster = bpb.fat32_root_cluster; 1723 1724 /* MC - if info_sector is 0, don't multiply by 0 */ 1725 sbi->fsinfo_sector = bpb.fat32_info_sector; 1726 if (sbi->fsinfo_sector == 0) 1727 sbi->fsinfo_sector = 1; 1728 1729 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1730 if (fsinfo_bh == NULL) { 1731 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1732 " (sector = %lu)", sbi->fsinfo_sector); 1733 goto out_fail; 1734 } 1735 1736 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1737 if (!IS_FSINFO(fsinfo)) { 1738 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1739 "0x%08x, 0x%08x (sector = %lu)", 1740 le32_to_cpu(fsinfo->signature1), 1741 le32_to_cpu(fsinfo->signature2), 1742 sbi->fsinfo_sector); 1743 } else { 1744 if (sbi->options.usefree) 1745 sbi->free_clus_valid = 1; 1746 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1747 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1748 } 1749 1750 brelse(fsinfo_bh); 1751 } 1752 1753 /* interpret volume ID as a little endian 32 bit integer */ 1754 if (is_fat32(sbi)) 1755 sbi->vol_id = bpb.fat32_vol_id; 1756 else /* fat 16 or 12 */ 1757 sbi->vol_id = bpb.fat16_vol_id; 1758 1759 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1760 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1761 1762 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1763 sbi->dir_entries = bpb.fat_dir_entries; 1764 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1765 if (!silent) 1766 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1767 " (%u)", sbi->dir_entries); 1768 goto out_invalid; 1769 } 1770 1771 rootdir_sectors = sbi->dir_entries 1772 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1773 sbi->data_start = sbi->dir_start + rootdir_sectors; 1774 total_sectors = bpb.fat_sectors; 1775 if (total_sectors == 0) 1776 total_sectors = bpb.fat_total_sect; 1777 1778 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1779 1780 if (!is_fat32(sbi)) 1781 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1782 1783 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1784 if (is_fat32(sbi)) 1785 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1786 else /* fat 16 or 12 */ 1787 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1788 1789 /* check that FAT table does not overflow */ 1790 fat_clusters = calc_fat_clusters(sb); 1791 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1792 if (total_clusters > max_fat(sb)) { 1793 if (!silent) 1794 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1795 total_clusters); 1796 goto out_invalid; 1797 } 1798 1799 sbi->max_cluster = total_clusters + FAT_START_ENT; 1800 /* check the free_clusters, it's not necessarily correct */ 1801 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1802 sbi->free_clusters = -1; 1803 /* check the prev_free, it's not necessarily correct */ 1804 sbi->prev_free %= sbi->max_cluster; 1805 if (sbi->prev_free < FAT_START_ENT) 1806 sbi->prev_free = FAT_START_ENT; 1807 1808 /* set up enough so that it can read an inode */ 1809 fat_hash_init(sb); 1810 dir_hash_init(sb); 1811 fat_ent_access_init(sb); 1812 1813 /* 1814 * The low byte of the first FAT entry must have the same value as 1815 * the media field of the boot sector. But in real world, too many 1816 * devices are writing wrong values. So, removed that validity check. 1817 * 1818 * The removed check compared the first FAT entry to a value dependent 1819 * on the media field like this: 1820 * == (0x0F00 | media), for FAT12 1821 * == (0XFF00 | media), for FAT16 1822 * == (0x0FFFFF | media), for FAT32 1823 */ 1824 1825 error = -EINVAL; 1826 sprintf(buf, "cp%d", sbi->options.codepage); 1827 sbi->nls_disk = load_nls(buf); 1828 if (!sbi->nls_disk) { 1829 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1830 goto out_fail; 1831 } 1832 1833 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1834 if (sbi->options.isvfat) { 1835 sbi->nls_io = load_nls(sbi->options.iocharset); 1836 if (!sbi->nls_io) { 1837 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1838 sbi->options.iocharset); 1839 goto out_fail; 1840 } 1841 } 1842 1843 error = -ENOMEM; 1844 fat_inode = new_inode(sb); 1845 if (!fat_inode) 1846 goto out_fail; 1847 sbi->fat_inode = fat_inode; 1848 1849 fsinfo_inode = new_inode(sb); 1850 if (!fsinfo_inode) 1851 goto out_fail; 1852 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1853 sbi->fsinfo_inode = fsinfo_inode; 1854 insert_inode_hash(fsinfo_inode); 1855 1856 root_inode = new_inode(sb); 1857 if (!root_inode) 1858 goto out_fail; 1859 root_inode->i_ino = MSDOS_ROOT_INO; 1860 inode_set_iversion(root_inode, 1); 1861 error = fat_read_root(root_inode); 1862 if (error < 0) { 1863 iput(root_inode); 1864 goto out_fail; 1865 } 1866 error = -ENOMEM; 1867 insert_inode_hash(root_inode); 1868 fat_attach(root_inode, 0); 1869 sb->s_root = d_make_root(root_inode); 1870 if (!sb->s_root) { 1871 fat_msg(sb, KERN_ERR, "get root inode failed"); 1872 goto out_fail; 1873 } 1874 1875 if (sbi->options.discard) { 1876 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1877 if (!blk_queue_discard(q)) 1878 fat_msg(sb, KERN_WARNING, 1879 "mounting with \"discard\" option, but " 1880 "the device does not support discard"); 1881 } 1882 1883 fat_set_state(sb, 1, 0); 1884 return 0; 1885 1886 out_invalid: 1887 error = -EINVAL; 1888 if (!silent) 1889 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1890 1891 out_fail: 1892 if (fsinfo_inode) 1893 iput(fsinfo_inode); 1894 if (fat_inode) 1895 iput(fat_inode); 1896 unload_nls(sbi->nls_io); 1897 unload_nls(sbi->nls_disk); 1898 fat_reset_iocharset(&sbi->options); 1899 sb->s_fs_info = NULL; 1900 kfree(sbi); 1901 return error; 1902 } 1903 1904 EXPORT_SYMBOL_GPL(fat_fill_super); 1905 1906 /* 1907 * helper function for fat_flush_inodes. This writes both the inode 1908 * and the file data blocks, waiting for in flight data blocks before 1909 * the start of the call. It does not wait for any io started 1910 * during the call 1911 */ 1912 static int writeback_inode(struct inode *inode) 1913 { 1914 1915 int ret; 1916 1917 /* if we used wait=1, sync_inode_metadata waits for the io for the 1918 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1919 * and filemap_fdatawrite is used for the data blocks 1920 */ 1921 ret = sync_inode_metadata(inode, 0); 1922 if (!ret) 1923 ret = filemap_fdatawrite(inode->i_mapping); 1924 return ret; 1925 } 1926 1927 /* 1928 * write data and metadata corresponding to i1 and i2. The io is 1929 * started but we do not wait for any of it to finish. 1930 * 1931 * filemap_flush is used for the block device, so if there is a dirty 1932 * page for a block already in flight, we will not wait and start the 1933 * io over again 1934 */ 1935 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1936 { 1937 int ret = 0; 1938 if (!MSDOS_SB(sb)->options.flush) 1939 return 0; 1940 if (i1) 1941 ret = writeback_inode(i1); 1942 if (!ret && i2) 1943 ret = writeback_inode(i2); 1944 if (!ret) 1945 ret = sync_blockdev_nowait(sb->s_bdev); 1946 return ret; 1947 } 1948 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1949 1950 static int __init init_fat_fs(void) 1951 { 1952 int err; 1953 1954 err = fat_cache_init(); 1955 if (err) 1956 return err; 1957 1958 err = fat_init_inodecache(); 1959 if (err) 1960 goto failed; 1961 1962 return 0; 1963 1964 failed: 1965 fat_cache_destroy(); 1966 return err; 1967 } 1968 1969 static void __exit exit_fat_fs(void) 1970 { 1971 fat_cache_destroy(); 1972 fat_destroy_inodecache(); 1973 } 1974 1975 module_init(init_fat_fs) 1976 module_exit(exit_fat_fs) 1977 1978 MODULE_LICENSE("GPL"); 1979