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 .set_page_dirty = __set_page_dirty_buffers, 346 .readpage = fat_readpage, 347 .readahead = fat_readahead, 348 .writepage = fat_writepage, 349 .writepages = fat_writepages, 350 .write_begin = fat_write_begin, 351 .write_end = fat_write_end, 352 .direct_IO = fat_direct_IO, 353 .bmap = _fat_bmap 354 }; 355 356 /* 357 * New FAT inode stuff. We do the following: 358 * a) i_ino is constant and has nothing with on-disk location. 359 * b) FAT manages its own cache of directory entries. 360 * c) *This* cache is indexed by on-disk location. 361 * d) inode has an associated directory entry, all right, but 362 * it may be unhashed. 363 * e) currently entries are stored within struct inode. That should 364 * change. 365 * f) we deal with races in the following way: 366 * 1. readdir() and lookup() do FAT-dir-cache lookup. 367 * 2. rename() unhashes the F-d-c entry and rehashes it in 368 * a new place. 369 * 3. unlink() and rmdir() unhash F-d-c entry. 370 * 4. fat_write_inode() checks whether the thing is unhashed. 371 * If it is we silently return. If it isn't we do bread(), 372 * check if the location is still valid and retry if it 373 * isn't. Otherwise we do changes. 374 * 5. Spinlock is used to protect hash/unhash/location check/lookup 375 * 6. fat_evict_inode() unhashes the F-d-c entry. 376 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 377 * and consider negative result as cache miss. 378 */ 379 380 static void fat_hash_init(struct super_block *sb) 381 { 382 struct msdos_sb_info *sbi = MSDOS_SB(sb); 383 int i; 384 385 spin_lock_init(&sbi->inode_hash_lock); 386 for (i = 0; i < FAT_HASH_SIZE; i++) 387 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 388 } 389 390 static inline unsigned long fat_hash(loff_t i_pos) 391 { 392 return hash_32(i_pos, FAT_HASH_BITS); 393 } 394 395 static void dir_hash_init(struct super_block *sb) 396 { 397 struct msdos_sb_info *sbi = MSDOS_SB(sb); 398 int i; 399 400 spin_lock_init(&sbi->dir_hash_lock); 401 for (i = 0; i < FAT_HASH_SIZE; i++) 402 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 403 } 404 405 void fat_attach(struct inode *inode, loff_t i_pos) 406 { 407 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 408 409 if (inode->i_ino != MSDOS_ROOT_INO) { 410 struct hlist_head *head = sbi->inode_hashtable 411 + fat_hash(i_pos); 412 413 spin_lock(&sbi->inode_hash_lock); 414 MSDOS_I(inode)->i_pos = i_pos; 415 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 416 spin_unlock(&sbi->inode_hash_lock); 417 } 418 419 /* If NFS support is enabled, cache the mapping of start cluster 420 * to directory inode. This is used during reconnection of 421 * dentries to the filesystem root. 422 */ 423 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 424 struct hlist_head *d_head = sbi->dir_hashtable; 425 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 426 427 spin_lock(&sbi->dir_hash_lock); 428 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 429 spin_unlock(&sbi->dir_hash_lock); 430 } 431 } 432 EXPORT_SYMBOL_GPL(fat_attach); 433 434 void fat_detach(struct inode *inode) 435 { 436 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 437 spin_lock(&sbi->inode_hash_lock); 438 MSDOS_I(inode)->i_pos = 0; 439 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 440 spin_unlock(&sbi->inode_hash_lock); 441 442 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 443 spin_lock(&sbi->dir_hash_lock); 444 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 445 spin_unlock(&sbi->dir_hash_lock); 446 } 447 } 448 EXPORT_SYMBOL_GPL(fat_detach); 449 450 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 451 { 452 struct msdos_sb_info *sbi = MSDOS_SB(sb); 453 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 454 struct msdos_inode_info *i; 455 struct inode *inode = NULL; 456 457 spin_lock(&sbi->inode_hash_lock); 458 hlist_for_each_entry(i, head, i_fat_hash) { 459 BUG_ON(i->vfs_inode.i_sb != sb); 460 if (i->i_pos != i_pos) 461 continue; 462 inode = igrab(&i->vfs_inode); 463 if (inode) 464 break; 465 } 466 spin_unlock(&sbi->inode_hash_lock); 467 return inode; 468 } 469 470 static int is_exec(unsigned char *extension) 471 { 472 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 473 474 for (walk = exe_extensions; *walk; walk += 3) 475 if (!strncmp(extension, walk, 3)) 476 return 1; 477 return 0; 478 } 479 480 static int fat_calc_dir_size(struct inode *inode) 481 { 482 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 483 int ret, fclus, dclus; 484 485 inode->i_size = 0; 486 if (MSDOS_I(inode)->i_start == 0) 487 return 0; 488 489 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 490 if (ret < 0) 491 return ret; 492 inode->i_size = (fclus + 1) << sbi->cluster_bits; 493 494 return 0; 495 } 496 497 static int fat_validate_dir(struct inode *dir) 498 { 499 struct super_block *sb = dir->i_sb; 500 501 if (dir->i_nlink < 2) { 502 /* Directory should have "."/".." entries at least. */ 503 fat_fs_error(sb, "corrupted directory (invalid entries)"); 504 return -EIO; 505 } 506 if (MSDOS_I(dir)->i_start == 0 || 507 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 508 /* Directory should point valid cluster. */ 509 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 510 return -EIO; 511 } 512 return 0; 513 } 514 515 /* doesn't deal with root inode */ 516 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 517 { 518 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 519 int error; 520 521 MSDOS_I(inode)->i_pos = 0; 522 inode->i_uid = sbi->options.fs_uid; 523 inode->i_gid = sbi->options.fs_gid; 524 inode_inc_iversion(inode); 525 inode->i_generation = prandom_u32(); 526 527 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 528 inode->i_generation &= ~1; 529 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 530 inode->i_op = sbi->dir_ops; 531 inode->i_fop = &fat_dir_operations; 532 533 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 534 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 535 error = fat_calc_dir_size(inode); 536 if (error < 0) 537 return error; 538 MSDOS_I(inode)->mmu_private = inode->i_size; 539 540 set_nlink(inode, fat_subdirs(inode)); 541 542 error = fat_validate_dir(inode); 543 if (error < 0) 544 return error; 545 } else { /* not a directory */ 546 inode->i_generation |= 1; 547 inode->i_mode = fat_make_mode(sbi, de->attr, 548 ((sbi->options.showexec && !is_exec(de->name + 8)) 549 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 550 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 551 552 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 553 inode->i_size = le32_to_cpu(de->size); 554 inode->i_op = &fat_file_inode_operations; 555 inode->i_fop = &fat_file_operations; 556 inode->i_mapping->a_ops = &fat_aops; 557 MSDOS_I(inode)->mmu_private = inode->i_size; 558 } 559 if (de->attr & ATTR_SYS) { 560 if (sbi->options.sys_immutable) 561 inode->i_flags |= S_IMMUTABLE; 562 } 563 fat_save_attrs(inode, de->attr); 564 565 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 566 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 567 568 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 569 if (sbi->options.isvfat) { 570 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 571 de->cdate, de->ctime_cs); 572 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 573 } else 574 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME); 575 576 return 0; 577 } 578 579 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 580 { 581 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 582 mutex_lock(&sbi->nfs_build_inode_lock); 583 } 584 585 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 586 { 587 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 588 mutex_unlock(&sbi->nfs_build_inode_lock); 589 } 590 591 struct inode *fat_build_inode(struct super_block *sb, 592 struct msdos_dir_entry *de, loff_t i_pos) 593 { 594 struct inode *inode; 595 int err; 596 597 fat_lock_build_inode(MSDOS_SB(sb)); 598 inode = fat_iget(sb, i_pos); 599 if (inode) 600 goto out; 601 inode = new_inode(sb); 602 if (!inode) { 603 inode = ERR_PTR(-ENOMEM); 604 goto out; 605 } 606 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 607 inode_set_iversion(inode, 1); 608 err = fat_fill_inode(inode, de); 609 if (err) { 610 iput(inode); 611 inode = ERR_PTR(err); 612 goto out; 613 } 614 fat_attach(inode, i_pos); 615 insert_inode_hash(inode); 616 out: 617 fat_unlock_build_inode(MSDOS_SB(sb)); 618 return inode; 619 } 620 621 EXPORT_SYMBOL_GPL(fat_build_inode); 622 623 static int __fat_write_inode(struct inode *inode, int wait); 624 625 static void fat_free_eofblocks(struct inode *inode) 626 { 627 /* Release unwritten fallocated blocks on inode eviction. */ 628 if ((inode->i_blocks << 9) > 629 round_up(MSDOS_I(inode)->mmu_private, 630 MSDOS_SB(inode->i_sb)->cluster_size)) { 631 int err; 632 633 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 634 /* Fallocate results in updating the i_start/iogstart 635 * for the zero byte file. So, make it return to 636 * original state during evict and commit it to avoid 637 * any corruption on the next access to the cluster 638 * chain for the file. 639 */ 640 err = __fat_write_inode(inode, inode_needs_sync(inode)); 641 if (err) { 642 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 643 "update on disk inode for unused " 644 "fallocated blocks, inode could be " 645 "corrupted. Please run fsck"); 646 } 647 648 } 649 } 650 651 static void fat_evict_inode(struct inode *inode) 652 { 653 truncate_inode_pages_final(&inode->i_data); 654 if (!inode->i_nlink) { 655 inode->i_size = 0; 656 fat_truncate_blocks(inode, 0); 657 } else 658 fat_free_eofblocks(inode); 659 660 invalidate_inode_buffers(inode); 661 clear_inode(inode); 662 fat_cache_inval_inode(inode); 663 fat_detach(inode); 664 } 665 666 static void fat_set_state(struct super_block *sb, 667 unsigned int set, unsigned int force) 668 { 669 struct buffer_head *bh; 670 struct fat_boot_sector *b; 671 struct msdos_sb_info *sbi = MSDOS_SB(sb); 672 673 /* do not change any thing if mounted read only */ 674 if (sb_rdonly(sb) && !force) 675 return; 676 677 /* do not change state if fs was dirty */ 678 if (sbi->dirty) { 679 /* warn only on set (mount). */ 680 if (set) 681 fat_msg(sb, KERN_WARNING, "Volume was not properly " 682 "unmounted. Some data may be corrupt. " 683 "Please run fsck."); 684 return; 685 } 686 687 bh = sb_bread(sb, 0); 688 if (bh == NULL) { 689 fat_msg(sb, KERN_ERR, "unable to read boot sector " 690 "to mark fs as dirty"); 691 return; 692 } 693 694 b = (struct fat_boot_sector *) bh->b_data; 695 696 if (is_fat32(sbi)) { 697 if (set) 698 b->fat32.state |= FAT_STATE_DIRTY; 699 else 700 b->fat32.state &= ~FAT_STATE_DIRTY; 701 } else /* fat 16 and 12 */ { 702 if (set) 703 b->fat16.state |= FAT_STATE_DIRTY; 704 else 705 b->fat16.state &= ~FAT_STATE_DIRTY; 706 } 707 708 mark_buffer_dirty(bh); 709 sync_dirty_buffer(bh); 710 brelse(bh); 711 } 712 713 static void fat_reset_iocharset(struct fat_mount_options *opts) 714 { 715 if (opts->iocharset != fat_default_iocharset) { 716 /* Note: opts->iocharset can be NULL here */ 717 kfree(opts->iocharset); 718 opts->iocharset = fat_default_iocharset; 719 } 720 } 721 722 static void delayed_free(struct rcu_head *p) 723 { 724 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 725 unload_nls(sbi->nls_disk); 726 unload_nls(sbi->nls_io); 727 fat_reset_iocharset(&sbi->options); 728 kfree(sbi); 729 } 730 731 static void fat_put_super(struct super_block *sb) 732 { 733 struct msdos_sb_info *sbi = MSDOS_SB(sb); 734 735 fat_set_state(sb, 0, 0); 736 737 iput(sbi->fsinfo_inode); 738 iput(sbi->fat_inode); 739 740 call_rcu(&sbi->rcu, delayed_free); 741 } 742 743 static struct kmem_cache *fat_inode_cachep; 744 745 static struct inode *fat_alloc_inode(struct super_block *sb) 746 { 747 struct msdos_inode_info *ei; 748 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 749 if (!ei) 750 return NULL; 751 752 init_rwsem(&ei->truncate_lock); 753 /* Zeroing to allow iput() even if partial initialized inode. */ 754 ei->mmu_private = 0; 755 ei->i_start = 0; 756 ei->i_logstart = 0; 757 ei->i_attrs = 0; 758 ei->i_pos = 0; 759 760 return &ei->vfs_inode; 761 } 762 763 static void fat_free_inode(struct inode *inode) 764 { 765 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 766 } 767 768 static void init_once(void *foo) 769 { 770 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 771 772 spin_lock_init(&ei->cache_lru_lock); 773 ei->nr_caches = 0; 774 ei->cache_valid_id = FAT_CACHE_VALID + 1; 775 INIT_LIST_HEAD(&ei->cache_lru); 776 INIT_HLIST_NODE(&ei->i_fat_hash); 777 INIT_HLIST_NODE(&ei->i_dir_hash); 778 inode_init_once(&ei->vfs_inode); 779 } 780 781 static int __init fat_init_inodecache(void) 782 { 783 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 784 sizeof(struct msdos_inode_info), 785 0, (SLAB_RECLAIM_ACCOUNT| 786 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 787 init_once); 788 if (fat_inode_cachep == NULL) 789 return -ENOMEM; 790 return 0; 791 } 792 793 static void __exit fat_destroy_inodecache(void) 794 { 795 /* 796 * Make sure all delayed rcu free inodes are flushed before we 797 * destroy cache. 798 */ 799 rcu_barrier(); 800 kmem_cache_destroy(fat_inode_cachep); 801 } 802 803 static int fat_remount(struct super_block *sb, int *flags, char *data) 804 { 805 bool new_rdonly; 806 struct msdos_sb_info *sbi = MSDOS_SB(sb); 807 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 808 809 sync_filesystem(sb); 810 811 /* make sure we update state on remount. */ 812 new_rdonly = *flags & SB_RDONLY; 813 if (new_rdonly != sb_rdonly(sb)) { 814 if (new_rdonly) 815 fat_set_state(sb, 0, 0); 816 else 817 fat_set_state(sb, 1, 1); 818 } 819 return 0; 820 } 821 822 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 823 { 824 struct super_block *sb = dentry->d_sb; 825 struct msdos_sb_info *sbi = MSDOS_SB(sb); 826 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 827 828 /* If the count of free cluster is still unknown, counts it here. */ 829 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 830 int err = fat_count_free_clusters(dentry->d_sb); 831 if (err) 832 return err; 833 } 834 835 buf->f_type = dentry->d_sb->s_magic; 836 buf->f_bsize = sbi->cluster_size; 837 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 838 buf->f_bfree = sbi->free_clusters; 839 buf->f_bavail = sbi->free_clusters; 840 buf->f_fsid = u64_to_fsid(id); 841 buf->f_namelen = 842 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 843 844 return 0; 845 } 846 847 static int __fat_write_inode(struct inode *inode, int wait) 848 { 849 struct super_block *sb = inode->i_sb; 850 struct msdos_sb_info *sbi = MSDOS_SB(sb); 851 struct buffer_head *bh; 852 struct msdos_dir_entry *raw_entry; 853 loff_t i_pos; 854 sector_t blocknr; 855 int err, offset; 856 857 if (inode->i_ino == MSDOS_ROOT_INO) 858 return 0; 859 860 retry: 861 i_pos = fat_i_pos_read(sbi, inode); 862 if (!i_pos) 863 return 0; 864 865 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 866 bh = sb_bread(sb, blocknr); 867 if (!bh) { 868 fat_msg(sb, KERN_ERR, "unable to read inode block " 869 "for updating (i_pos %lld)", i_pos); 870 return -EIO; 871 } 872 spin_lock(&sbi->inode_hash_lock); 873 if (i_pos != MSDOS_I(inode)->i_pos) { 874 spin_unlock(&sbi->inode_hash_lock); 875 brelse(bh); 876 goto retry; 877 } 878 879 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 880 if (S_ISDIR(inode->i_mode)) 881 raw_entry->size = 0; 882 else 883 raw_entry->size = cpu_to_le32(inode->i_size); 884 raw_entry->attr = fat_make_attrs(inode); 885 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 886 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 887 &raw_entry->date, NULL); 888 if (sbi->options.isvfat) { 889 __le16 atime; 890 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 891 &raw_entry->cdate, &raw_entry->ctime_cs); 892 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 893 &raw_entry->adate, NULL); 894 } 895 spin_unlock(&sbi->inode_hash_lock); 896 mark_buffer_dirty(bh); 897 err = 0; 898 if (wait) 899 err = sync_dirty_buffer(bh); 900 brelse(bh); 901 return err; 902 } 903 904 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 905 { 906 int err; 907 908 if (inode->i_ino == MSDOS_FSINFO_INO) { 909 struct super_block *sb = inode->i_sb; 910 911 mutex_lock(&MSDOS_SB(sb)->s_lock); 912 err = fat_clusters_flush(sb); 913 mutex_unlock(&MSDOS_SB(sb)->s_lock); 914 } else 915 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 916 917 return err; 918 } 919 920 int fat_sync_inode(struct inode *inode) 921 { 922 return __fat_write_inode(inode, 1); 923 } 924 925 EXPORT_SYMBOL_GPL(fat_sync_inode); 926 927 static int fat_show_options(struct seq_file *m, struct dentry *root); 928 static const struct super_operations fat_sops = { 929 .alloc_inode = fat_alloc_inode, 930 .free_inode = fat_free_inode, 931 .write_inode = fat_write_inode, 932 .evict_inode = fat_evict_inode, 933 .put_super = fat_put_super, 934 .statfs = fat_statfs, 935 .remount_fs = fat_remount, 936 937 .show_options = fat_show_options, 938 }; 939 940 static int fat_show_options(struct seq_file *m, struct dentry *root) 941 { 942 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 943 struct fat_mount_options *opts = &sbi->options; 944 int isvfat = opts->isvfat; 945 946 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 947 seq_printf(m, ",uid=%u", 948 from_kuid_munged(&init_user_ns, opts->fs_uid)); 949 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 950 seq_printf(m, ",gid=%u", 951 from_kgid_munged(&init_user_ns, opts->fs_gid)); 952 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 953 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 954 if (opts->allow_utime) 955 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 956 if (sbi->nls_disk) 957 /* strip "cp" prefix from displayed option */ 958 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 959 if (isvfat) { 960 if (sbi->nls_io) 961 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 962 963 switch (opts->shortname) { 964 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 965 seq_puts(m, ",shortname=win95"); 966 break; 967 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 968 seq_puts(m, ",shortname=winnt"); 969 break; 970 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 971 seq_puts(m, ",shortname=mixed"); 972 break; 973 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 974 seq_puts(m, ",shortname=lower"); 975 break; 976 default: 977 seq_puts(m, ",shortname=unknown"); 978 break; 979 } 980 } 981 if (opts->name_check != 'n') 982 seq_printf(m, ",check=%c", opts->name_check); 983 if (opts->usefree) 984 seq_puts(m, ",usefree"); 985 if (opts->quiet) 986 seq_puts(m, ",quiet"); 987 if (opts->showexec) 988 seq_puts(m, ",showexec"); 989 if (opts->sys_immutable) 990 seq_puts(m, ",sys_immutable"); 991 if (!isvfat) { 992 if (opts->dotsOK) 993 seq_puts(m, ",dotsOK=yes"); 994 if (opts->nocase) 995 seq_puts(m, ",nocase"); 996 } else { 997 if (opts->utf8) 998 seq_puts(m, ",utf8"); 999 if (opts->unicode_xlate) 1000 seq_puts(m, ",uni_xlate"); 1001 if (!opts->numtail) 1002 seq_puts(m, ",nonumtail"); 1003 if (opts->rodir) 1004 seq_puts(m, ",rodir"); 1005 } 1006 if (opts->flush) 1007 seq_puts(m, ",flush"); 1008 if (opts->tz_set) { 1009 if (opts->time_offset) 1010 seq_printf(m, ",time_offset=%d", opts->time_offset); 1011 else 1012 seq_puts(m, ",tz=UTC"); 1013 } 1014 if (opts->errors == FAT_ERRORS_CONT) 1015 seq_puts(m, ",errors=continue"); 1016 else if (opts->errors == FAT_ERRORS_PANIC) 1017 seq_puts(m, ",errors=panic"); 1018 else 1019 seq_puts(m, ",errors=remount-ro"); 1020 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1021 seq_puts(m, ",nfs=nostale_ro"); 1022 else if (opts->nfs) 1023 seq_puts(m, ",nfs=stale_rw"); 1024 if (opts->discard) 1025 seq_puts(m, ",discard"); 1026 if (opts->dos1xfloppy) 1027 seq_puts(m, ",dos1xfloppy"); 1028 1029 return 0; 1030 } 1031 1032 enum { 1033 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1034 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1035 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1036 Opt_immutable, Opt_dots, Opt_nodots, 1037 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1038 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1039 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1040 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1041 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1042 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1043 }; 1044 1045 static const match_table_t fat_tokens = { 1046 {Opt_check_r, "check=relaxed"}, 1047 {Opt_check_s, "check=strict"}, 1048 {Opt_check_n, "check=normal"}, 1049 {Opt_check_r, "check=r"}, 1050 {Opt_check_s, "check=s"}, 1051 {Opt_check_n, "check=n"}, 1052 {Opt_uid, "uid=%u"}, 1053 {Opt_gid, "gid=%u"}, 1054 {Opt_umask, "umask=%o"}, 1055 {Opt_dmask, "dmask=%o"}, 1056 {Opt_fmask, "fmask=%o"}, 1057 {Opt_allow_utime, "allow_utime=%o"}, 1058 {Opt_codepage, "codepage=%u"}, 1059 {Opt_usefree, "usefree"}, 1060 {Opt_nocase, "nocase"}, 1061 {Opt_quiet, "quiet"}, 1062 {Opt_showexec, "showexec"}, 1063 {Opt_debug, "debug"}, 1064 {Opt_immutable, "sys_immutable"}, 1065 {Opt_flush, "flush"}, 1066 {Opt_tz_utc, "tz=UTC"}, 1067 {Opt_time_offset, "time_offset=%d"}, 1068 {Opt_err_cont, "errors=continue"}, 1069 {Opt_err_panic, "errors=panic"}, 1070 {Opt_err_ro, "errors=remount-ro"}, 1071 {Opt_discard, "discard"}, 1072 {Opt_nfs_stale_rw, "nfs"}, 1073 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1074 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1075 {Opt_dos1xfloppy, "dos1xfloppy"}, 1076 {Opt_obsolete, "conv=binary"}, 1077 {Opt_obsolete, "conv=text"}, 1078 {Opt_obsolete, "conv=auto"}, 1079 {Opt_obsolete, "conv=b"}, 1080 {Opt_obsolete, "conv=t"}, 1081 {Opt_obsolete, "conv=a"}, 1082 {Opt_obsolete, "fat=%u"}, 1083 {Opt_obsolete, "blocksize=%u"}, 1084 {Opt_obsolete, "cvf_format=%20s"}, 1085 {Opt_obsolete, "cvf_options=%100s"}, 1086 {Opt_obsolete, "posix"}, 1087 {Opt_err, NULL}, 1088 }; 1089 static const match_table_t msdos_tokens = { 1090 {Opt_nodots, "nodots"}, 1091 {Opt_nodots, "dotsOK=no"}, 1092 {Opt_dots, "dots"}, 1093 {Opt_dots, "dotsOK=yes"}, 1094 {Opt_err, NULL} 1095 }; 1096 static const match_table_t vfat_tokens = { 1097 {Opt_charset, "iocharset=%s"}, 1098 {Opt_shortname_lower, "shortname=lower"}, 1099 {Opt_shortname_win95, "shortname=win95"}, 1100 {Opt_shortname_winnt, "shortname=winnt"}, 1101 {Opt_shortname_mixed, "shortname=mixed"}, 1102 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1103 {Opt_utf8_no, "utf8=no"}, 1104 {Opt_utf8_no, "utf8=false"}, 1105 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1106 {Opt_utf8_yes, "utf8=yes"}, 1107 {Opt_utf8_yes, "utf8=true"}, 1108 {Opt_utf8_yes, "utf8"}, 1109 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1110 {Opt_uni_xl_no, "uni_xlate=no"}, 1111 {Opt_uni_xl_no, "uni_xlate=false"}, 1112 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1113 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1114 {Opt_uni_xl_yes, "uni_xlate=true"}, 1115 {Opt_uni_xl_yes, "uni_xlate"}, 1116 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1117 {Opt_nonumtail_no, "nonumtail=no"}, 1118 {Opt_nonumtail_no, "nonumtail=false"}, 1119 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1120 {Opt_nonumtail_yes, "nonumtail=yes"}, 1121 {Opt_nonumtail_yes, "nonumtail=true"}, 1122 {Opt_nonumtail_yes, "nonumtail"}, 1123 {Opt_rodir, "rodir"}, 1124 {Opt_err, NULL} 1125 }; 1126 1127 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1128 int silent, int *debug, struct fat_mount_options *opts) 1129 { 1130 char *p; 1131 substring_t args[MAX_OPT_ARGS]; 1132 int option; 1133 char *iocharset; 1134 1135 opts->isvfat = is_vfat; 1136 1137 opts->fs_uid = current_uid(); 1138 opts->fs_gid = current_gid(); 1139 opts->fs_fmask = opts->fs_dmask = current_umask(); 1140 opts->allow_utime = -1; 1141 opts->codepage = fat_default_codepage; 1142 fat_reset_iocharset(opts); 1143 if (is_vfat) { 1144 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1145 opts->rodir = 0; 1146 } else { 1147 opts->shortname = 0; 1148 opts->rodir = 1; 1149 } 1150 opts->name_check = 'n'; 1151 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1152 opts->unicode_xlate = 0; 1153 opts->numtail = 1; 1154 opts->usefree = opts->nocase = 0; 1155 opts->tz_set = 0; 1156 opts->nfs = 0; 1157 opts->errors = FAT_ERRORS_RO; 1158 *debug = 0; 1159 1160 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1161 1162 if (!options) 1163 goto out; 1164 1165 while ((p = strsep(&options, ",")) != NULL) { 1166 int token; 1167 if (!*p) 1168 continue; 1169 1170 token = match_token(p, fat_tokens, args); 1171 if (token == Opt_err) { 1172 if (is_vfat) 1173 token = match_token(p, vfat_tokens, args); 1174 else 1175 token = match_token(p, msdos_tokens, args); 1176 } 1177 switch (token) { 1178 case Opt_check_s: 1179 opts->name_check = 's'; 1180 break; 1181 case Opt_check_r: 1182 opts->name_check = 'r'; 1183 break; 1184 case Opt_check_n: 1185 opts->name_check = 'n'; 1186 break; 1187 case Opt_usefree: 1188 opts->usefree = 1; 1189 break; 1190 case Opt_nocase: 1191 if (!is_vfat) 1192 opts->nocase = 1; 1193 else { 1194 /* for backward compatibility */ 1195 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1196 | VFAT_SFN_CREATE_WIN95; 1197 } 1198 break; 1199 case Opt_quiet: 1200 opts->quiet = 1; 1201 break; 1202 case Opt_showexec: 1203 opts->showexec = 1; 1204 break; 1205 case Opt_debug: 1206 *debug = 1; 1207 break; 1208 case Opt_immutable: 1209 opts->sys_immutable = 1; 1210 break; 1211 case Opt_uid: 1212 if (match_int(&args[0], &option)) 1213 return -EINVAL; 1214 opts->fs_uid = make_kuid(current_user_ns(), option); 1215 if (!uid_valid(opts->fs_uid)) 1216 return -EINVAL; 1217 break; 1218 case Opt_gid: 1219 if (match_int(&args[0], &option)) 1220 return -EINVAL; 1221 opts->fs_gid = make_kgid(current_user_ns(), option); 1222 if (!gid_valid(opts->fs_gid)) 1223 return -EINVAL; 1224 break; 1225 case Opt_umask: 1226 if (match_octal(&args[0], &option)) 1227 return -EINVAL; 1228 opts->fs_fmask = opts->fs_dmask = option; 1229 break; 1230 case Opt_dmask: 1231 if (match_octal(&args[0], &option)) 1232 return -EINVAL; 1233 opts->fs_dmask = option; 1234 break; 1235 case Opt_fmask: 1236 if (match_octal(&args[0], &option)) 1237 return -EINVAL; 1238 opts->fs_fmask = option; 1239 break; 1240 case Opt_allow_utime: 1241 if (match_octal(&args[0], &option)) 1242 return -EINVAL; 1243 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1244 break; 1245 case Opt_codepage: 1246 if (match_int(&args[0], &option)) 1247 return -EINVAL; 1248 opts->codepage = option; 1249 break; 1250 case Opt_flush: 1251 opts->flush = 1; 1252 break; 1253 case Opt_time_offset: 1254 if (match_int(&args[0], &option)) 1255 return -EINVAL; 1256 /* 1257 * GMT+-12 zones may have DST corrections so at least 1258 * 13 hours difference is needed. Make the limit 24 1259 * just in case someone invents something unusual. 1260 */ 1261 if (option < -24 * 60 || option > 24 * 60) 1262 return -EINVAL; 1263 opts->tz_set = 1; 1264 opts->time_offset = option; 1265 break; 1266 case Opt_tz_utc: 1267 opts->tz_set = 1; 1268 opts->time_offset = 0; 1269 break; 1270 case Opt_err_cont: 1271 opts->errors = FAT_ERRORS_CONT; 1272 break; 1273 case Opt_err_panic: 1274 opts->errors = FAT_ERRORS_PANIC; 1275 break; 1276 case Opt_err_ro: 1277 opts->errors = FAT_ERRORS_RO; 1278 break; 1279 case Opt_nfs_stale_rw: 1280 opts->nfs = FAT_NFS_STALE_RW; 1281 break; 1282 case Opt_nfs_nostale_ro: 1283 opts->nfs = FAT_NFS_NOSTALE_RO; 1284 break; 1285 case Opt_dos1xfloppy: 1286 opts->dos1xfloppy = 1; 1287 break; 1288 1289 /* msdos specific */ 1290 case Opt_dots: 1291 opts->dotsOK = 1; 1292 break; 1293 case Opt_nodots: 1294 opts->dotsOK = 0; 1295 break; 1296 1297 /* vfat specific */ 1298 case Opt_charset: 1299 fat_reset_iocharset(opts); 1300 iocharset = match_strdup(&args[0]); 1301 if (!iocharset) 1302 return -ENOMEM; 1303 opts->iocharset = iocharset; 1304 break; 1305 case Opt_shortname_lower: 1306 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1307 | VFAT_SFN_CREATE_WIN95; 1308 break; 1309 case Opt_shortname_win95: 1310 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1311 | VFAT_SFN_CREATE_WIN95; 1312 break; 1313 case Opt_shortname_winnt: 1314 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1315 | VFAT_SFN_CREATE_WINNT; 1316 break; 1317 case Opt_shortname_mixed: 1318 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1319 | VFAT_SFN_CREATE_WIN95; 1320 break; 1321 case Opt_utf8_no: /* 0 or no or false */ 1322 opts->utf8 = 0; 1323 break; 1324 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1325 opts->utf8 = 1; 1326 break; 1327 case Opt_uni_xl_no: /* 0 or no or false */ 1328 opts->unicode_xlate = 0; 1329 break; 1330 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1331 opts->unicode_xlate = 1; 1332 break; 1333 case Opt_nonumtail_no: /* 0 or no or false */ 1334 opts->numtail = 1; /* negated option */ 1335 break; 1336 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1337 opts->numtail = 0; /* negated option */ 1338 break; 1339 case Opt_rodir: 1340 opts->rodir = 1; 1341 break; 1342 case Opt_discard: 1343 opts->discard = 1; 1344 break; 1345 1346 /* obsolete mount options */ 1347 case Opt_obsolete: 1348 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1349 "not supported now", p); 1350 break; 1351 /* unknown option */ 1352 default: 1353 if (!silent) { 1354 fat_msg(sb, KERN_ERR, 1355 "Unrecognized mount option \"%s\" " 1356 "or missing value", p); 1357 } 1358 return -EINVAL; 1359 } 1360 } 1361 1362 out: 1363 /* UTF-8 doesn't provide FAT semantics */ 1364 if (!strcmp(opts->iocharset, "utf8")) { 1365 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1366 " for FAT filesystems, filesystem will be " 1367 "case sensitive!"); 1368 } 1369 1370 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1371 if (opts->allow_utime == (unsigned short)-1) 1372 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1373 if (opts->unicode_xlate) 1374 opts->utf8 = 0; 1375 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1376 sb->s_flags |= SB_RDONLY; 1377 sb->s_export_op = &fat_export_ops_nostale; 1378 } 1379 1380 return 0; 1381 } 1382 1383 static int fat_read_root(struct inode *inode) 1384 { 1385 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1386 int error; 1387 1388 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1389 inode->i_uid = sbi->options.fs_uid; 1390 inode->i_gid = sbi->options.fs_gid; 1391 inode_inc_iversion(inode); 1392 inode->i_generation = 0; 1393 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1394 inode->i_op = sbi->dir_ops; 1395 inode->i_fop = &fat_dir_operations; 1396 if (is_fat32(sbi)) { 1397 MSDOS_I(inode)->i_start = sbi->root_cluster; 1398 error = fat_calc_dir_size(inode); 1399 if (error < 0) 1400 return error; 1401 } else { 1402 MSDOS_I(inode)->i_start = 0; 1403 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1404 } 1405 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1406 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1407 MSDOS_I(inode)->i_logstart = 0; 1408 MSDOS_I(inode)->mmu_private = inode->i_size; 1409 1410 fat_save_attrs(inode, ATTR_DIR); 1411 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1412 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1413 set_nlink(inode, fat_subdirs(inode)+2); 1414 1415 return 0; 1416 } 1417 1418 static unsigned long calc_fat_clusters(struct super_block *sb) 1419 { 1420 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1421 1422 /* Divide first to avoid overflow */ 1423 if (!is_fat12(sbi)) { 1424 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1425 return ent_per_sec * sbi->fat_length; 1426 } 1427 1428 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1429 } 1430 1431 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1432 { 1433 if (get_unaligned_le16(&b->sector_size)) 1434 return false; 1435 if (b->sec_per_clus) 1436 return false; 1437 if (b->reserved) 1438 return false; 1439 if (b->fats) 1440 return false; 1441 if (get_unaligned_le16(&b->dir_entries)) 1442 return false; 1443 if (get_unaligned_le16(&b->sectors)) 1444 return false; 1445 if (b->media) 1446 return false; 1447 if (b->fat_length) 1448 return false; 1449 if (b->secs_track) 1450 return false; 1451 if (b->heads) 1452 return false; 1453 return true; 1454 } 1455 1456 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1457 int silent, struct fat_bios_param_block *bpb) 1458 { 1459 int error = -EINVAL; 1460 1461 /* Read in BPB ... */ 1462 memset(bpb, 0, sizeof(*bpb)); 1463 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1464 bpb->fat_sec_per_clus = b->sec_per_clus; 1465 bpb->fat_reserved = le16_to_cpu(b->reserved); 1466 bpb->fat_fats = b->fats; 1467 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1468 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1469 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1470 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1471 1472 bpb->fat16_state = b->fat16.state; 1473 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1474 1475 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1476 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1477 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1478 bpb->fat32_state = b->fat32.state; 1479 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1480 1481 /* Validate this looks like a FAT filesystem BPB */ 1482 if (!bpb->fat_reserved) { 1483 if (!silent) 1484 fat_msg(sb, KERN_ERR, 1485 "bogus number of reserved sectors"); 1486 goto out; 1487 } 1488 if (!bpb->fat_fats) { 1489 if (!silent) 1490 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1491 goto out; 1492 } 1493 1494 /* 1495 * Earlier we checked here that b->secs_track and b->head are nonzero, 1496 * but it turns out valid FAT filesystems can have zero there. 1497 */ 1498 1499 if (!fat_valid_media(b->media)) { 1500 if (!silent) 1501 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1502 (unsigned)b->media); 1503 goto out; 1504 } 1505 1506 if (!is_power_of_2(bpb->fat_sector_size) 1507 || (bpb->fat_sector_size < 512) 1508 || (bpb->fat_sector_size > 4096)) { 1509 if (!silent) 1510 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1511 (unsigned)bpb->fat_sector_size); 1512 goto out; 1513 } 1514 1515 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1516 if (!silent) 1517 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1518 (unsigned)bpb->fat_sec_per_clus); 1519 goto out; 1520 } 1521 1522 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1523 if (!silent) 1524 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1525 goto out; 1526 } 1527 1528 error = 0; 1529 1530 out: 1531 return error; 1532 } 1533 1534 static int fat_read_static_bpb(struct super_block *sb, 1535 struct fat_boot_sector *b, int silent, 1536 struct fat_bios_param_block *bpb) 1537 { 1538 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1539 1540 struct fat_floppy_defaults *fdefaults = NULL; 1541 int error = -EINVAL; 1542 sector_t bd_sects; 1543 unsigned i; 1544 1545 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1546 1547 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1548 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1549 if (!silent) 1550 fat_msg(sb, KERN_ERR, 1551 "%s; no bootstrapping code", notdos1x); 1552 goto out; 1553 } 1554 1555 /* 1556 * If any value in this region is non-zero, it isn't archaic 1557 * DOS. 1558 */ 1559 if (!fat_bpb_is_zero(b)) { 1560 if (!silent) 1561 fat_msg(sb, KERN_ERR, 1562 "%s; DOS 2.x BPB is non-zero", notdos1x); 1563 goto out; 1564 } 1565 1566 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1567 if (floppy_defaults[i].nr_sectors == bd_sects) { 1568 fdefaults = &floppy_defaults[i]; 1569 break; 1570 } 1571 } 1572 1573 if (fdefaults == NULL) { 1574 if (!silent) 1575 fat_msg(sb, KERN_WARNING, 1576 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1577 (u64)bd_sects); 1578 goto out; 1579 } 1580 1581 if (!silent) 1582 fat_msg(sb, KERN_INFO, 1583 "This looks like a DOS 1.x volume; assuming default BPB values"); 1584 1585 memset(bpb, 0, sizeof(*bpb)); 1586 bpb->fat_sector_size = SECTOR_SIZE; 1587 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1588 bpb->fat_reserved = 1; 1589 bpb->fat_fats = 2; 1590 bpb->fat_dir_entries = fdefaults->dir_entries; 1591 bpb->fat_sectors = fdefaults->nr_sectors; 1592 bpb->fat_fat_length = fdefaults->fat_length; 1593 1594 error = 0; 1595 1596 out: 1597 return error; 1598 } 1599 1600 /* 1601 * Read the super block of an MS-DOS FS. 1602 */ 1603 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1604 void (*setup)(struct super_block *)) 1605 { 1606 struct inode *root_inode = NULL, *fat_inode = NULL; 1607 struct inode *fsinfo_inode = NULL; 1608 struct buffer_head *bh; 1609 struct fat_bios_param_block bpb; 1610 struct msdos_sb_info *sbi; 1611 u16 logical_sector_size; 1612 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1613 int debug; 1614 long error; 1615 char buf[50]; 1616 struct timespec64 ts; 1617 1618 /* 1619 * GFP_KERNEL is ok here, because while we do hold the 1620 * superblock lock, memory pressure can't call back into 1621 * the filesystem, since we're only just about to mount 1622 * it and have no inodes etc active! 1623 */ 1624 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1625 if (!sbi) 1626 return -ENOMEM; 1627 sb->s_fs_info = sbi; 1628 1629 sb->s_flags |= SB_NODIRATIME; 1630 sb->s_magic = MSDOS_SUPER_MAGIC; 1631 sb->s_op = &fat_sops; 1632 sb->s_export_op = &fat_export_ops; 1633 /* 1634 * fat timestamps are complex and truncated by fat itself, so 1635 * we set 1 here to be fast 1636 */ 1637 sb->s_time_gran = 1; 1638 mutex_init(&sbi->nfs_build_inode_lock); 1639 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1640 DEFAULT_RATELIMIT_BURST); 1641 1642 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1643 if (error) 1644 goto out_fail; 1645 1646 setup(sb); /* flavour-specific stuff that needs options */ 1647 1648 error = -EIO; 1649 sb_min_blocksize(sb, 512); 1650 bh = sb_bread(sb, 0); 1651 if (bh == NULL) { 1652 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1653 goto out_fail; 1654 } 1655 1656 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1657 &bpb); 1658 if (error == -EINVAL && sbi->options.dos1xfloppy) 1659 error = fat_read_static_bpb(sb, 1660 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1661 brelse(bh); 1662 1663 if (error == -EINVAL) 1664 goto out_invalid; 1665 else if (error) 1666 goto out_fail; 1667 1668 logical_sector_size = bpb.fat_sector_size; 1669 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1670 1671 error = -EIO; 1672 if (logical_sector_size < sb->s_blocksize) { 1673 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1674 " (logical sector size = %u)", logical_sector_size); 1675 goto out_fail; 1676 } 1677 1678 if (logical_sector_size > sb->s_blocksize) { 1679 struct buffer_head *bh_resize; 1680 1681 if (!sb_set_blocksize(sb, logical_sector_size)) { 1682 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1683 logical_sector_size); 1684 goto out_fail; 1685 } 1686 1687 /* Verify that the larger boot sector is fully readable */ 1688 bh_resize = sb_bread(sb, 0); 1689 if (bh_resize == NULL) { 1690 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1691 " (logical sector size = %lu)", 1692 sb->s_blocksize); 1693 goto out_fail; 1694 } 1695 brelse(bh_resize); 1696 } 1697 1698 mutex_init(&sbi->s_lock); 1699 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1700 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1701 sbi->fats = bpb.fat_fats; 1702 sbi->fat_bits = 0; /* Don't know yet */ 1703 sbi->fat_start = bpb.fat_reserved; 1704 sbi->fat_length = bpb.fat_fat_length; 1705 sbi->root_cluster = 0; 1706 sbi->free_clusters = -1; /* Don't know yet */ 1707 sbi->free_clus_valid = 0; 1708 sbi->prev_free = FAT_START_ENT; 1709 sb->s_maxbytes = 0xffffffff; 1710 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1711 sb->s_time_min = ts.tv_sec; 1712 1713 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1714 cpu_to_le16(FAT_DATE_MAX), 0); 1715 sb->s_time_max = ts.tv_sec; 1716 1717 if (!sbi->fat_length && bpb.fat32_length) { 1718 struct fat_boot_fsinfo *fsinfo; 1719 struct buffer_head *fsinfo_bh; 1720 1721 /* Must be FAT32 */ 1722 sbi->fat_bits = 32; 1723 sbi->fat_length = bpb.fat32_length; 1724 sbi->root_cluster = bpb.fat32_root_cluster; 1725 1726 /* MC - if info_sector is 0, don't multiply by 0 */ 1727 sbi->fsinfo_sector = bpb.fat32_info_sector; 1728 if (sbi->fsinfo_sector == 0) 1729 sbi->fsinfo_sector = 1; 1730 1731 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1732 if (fsinfo_bh == NULL) { 1733 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1734 " (sector = %lu)", sbi->fsinfo_sector); 1735 goto out_fail; 1736 } 1737 1738 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1739 if (!IS_FSINFO(fsinfo)) { 1740 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1741 "0x%08x, 0x%08x (sector = %lu)", 1742 le32_to_cpu(fsinfo->signature1), 1743 le32_to_cpu(fsinfo->signature2), 1744 sbi->fsinfo_sector); 1745 } else { 1746 if (sbi->options.usefree) 1747 sbi->free_clus_valid = 1; 1748 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1749 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1750 } 1751 1752 brelse(fsinfo_bh); 1753 } 1754 1755 /* interpret volume ID as a little endian 32 bit integer */ 1756 if (is_fat32(sbi)) 1757 sbi->vol_id = bpb.fat32_vol_id; 1758 else /* fat 16 or 12 */ 1759 sbi->vol_id = bpb.fat16_vol_id; 1760 1761 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1762 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1763 1764 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1765 sbi->dir_entries = bpb.fat_dir_entries; 1766 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1767 if (!silent) 1768 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1769 " (%u)", sbi->dir_entries); 1770 goto out_invalid; 1771 } 1772 1773 rootdir_sectors = sbi->dir_entries 1774 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1775 sbi->data_start = sbi->dir_start + rootdir_sectors; 1776 total_sectors = bpb.fat_sectors; 1777 if (total_sectors == 0) 1778 total_sectors = bpb.fat_total_sect; 1779 1780 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1781 1782 if (!is_fat32(sbi)) 1783 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1784 1785 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1786 if (is_fat32(sbi)) 1787 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1788 else /* fat 16 or 12 */ 1789 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1790 1791 /* check that FAT table does not overflow */ 1792 fat_clusters = calc_fat_clusters(sb); 1793 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1794 if (total_clusters > max_fat(sb)) { 1795 if (!silent) 1796 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1797 total_clusters); 1798 goto out_invalid; 1799 } 1800 1801 sbi->max_cluster = total_clusters + FAT_START_ENT; 1802 /* check the free_clusters, it's not necessarily correct */ 1803 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1804 sbi->free_clusters = -1; 1805 /* check the prev_free, it's not necessarily correct */ 1806 sbi->prev_free %= sbi->max_cluster; 1807 if (sbi->prev_free < FAT_START_ENT) 1808 sbi->prev_free = FAT_START_ENT; 1809 1810 /* set up enough so that it can read an inode */ 1811 fat_hash_init(sb); 1812 dir_hash_init(sb); 1813 fat_ent_access_init(sb); 1814 1815 /* 1816 * The low byte of the first FAT entry must have the same value as 1817 * the media field of the boot sector. But in real world, too many 1818 * devices are writing wrong values. So, removed that validity check. 1819 * 1820 * The removed check compared the first FAT entry to a value dependent 1821 * on the media field like this: 1822 * == (0x0F00 | media), for FAT12 1823 * == (0XFF00 | media), for FAT16 1824 * == (0x0FFFFF | media), for FAT32 1825 */ 1826 1827 error = -EINVAL; 1828 sprintf(buf, "cp%d", sbi->options.codepage); 1829 sbi->nls_disk = load_nls(buf); 1830 if (!sbi->nls_disk) { 1831 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1832 goto out_fail; 1833 } 1834 1835 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1836 if (sbi->options.isvfat) { 1837 sbi->nls_io = load_nls(sbi->options.iocharset); 1838 if (!sbi->nls_io) { 1839 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1840 sbi->options.iocharset); 1841 goto out_fail; 1842 } 1843 } 1844 1845 error = -ENOMEM; 1846 fat_inode = new_inode(sb); 1847 if (!fat_inode) 1848 goto out_fail; 1849 sbi->fat_inode = fat_inode; 1850 1851 fsinfo_inode = new_inode(sb); 1852 if (!fsinfo_inode) 1853 goto out_fail; 1854 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1855 sbi->fsinfo_inode = fsinfo_inode; 1856 insert_inode_hash(fsinfo_inode); 1857 1858 root_inode = new_inode(sb); 1859 if (!root_inode) 1860 goto out_fail; 1861 root_inode->i_ino = MSDOS_ROOT_INO; 1862 inode_set_iversion(root_inode, 1); 1863 error = fat_read_root(root_inode); 1864 if (error < 0) { 1865 iput(root_inode); 1866 goto out_fail; 1867 } 1868 error = -ENOMEM; 1869 insert_inode_hash(root_inode); 1870 fat_attach(root_inode, 0); 1871 sb->s_root = d_make_root(root_inode); 1872 if (!sb->s_root) { 1873 fat_msg(sb, KERN_ERR, "get root inode failed"); 1874 goto out_fail; 1875 } 1876 1877 if (sbi->options.discard) { 1878 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1879 if (!blk_queue_discard(q)) 1880 fat_msg(sb, KERN_WARNING, 1881 "mounting with \"discard\" option, but " 1882 "the device does not support discard"); 1883 } 1884 1885 fat_set_state(sb, 1, 0); 1886 return 0; 1887 1888 out_invalid: 1889 error = -EINVAL; 1890 if (!silent) 1891 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1892 1893 out_fail: 1894 if (fsinfo_inode) 1895 iput(fsinfo_inode); 1896 if (fat_inode) 1897 iput(fat_inode); 1898 unload_nls(sbi->nls_io); 1899 unload_nls(sbi->nls_disk); 1900 fat_reset_iocharset(&sbi->options); 1901 sb->s_fs_info = NULL; 1902 kfree(sbi); 1903 return error; 1904 } 1905 1906 EXPORT_SYMBOL_GPL(fat_fill_super); 1907 1908 /* 1909 * helper function for fat_flush_inodes. This writes both the inode 1910 * and the file data blocks, waiting for in flight data blocks before 1911 * the start of the call. It does not wait for any io started 1912 * during the call 1913 */ 1914 static int writeback_inode(struct inode *inode) 1915 { 1916 1917 int ret; 1918 1919 /* if we used wait=1, sync_inode_metadata waits for the io for the 1920 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1921 * and filemap_fdatawrite is used for the data blocks 1922 */ 1923 ret = sync_inode_metadata(inode, 0); 1924 if (!ret) 1925 ret = filemap_fdatawrite(inode->i_mapping); 1926 return ret; 1927 } 1928 1929 /* 1930 * write data and metadata corresponding to i1 and i2. The io is 1931 * started but we do not wait for any of it to finish. 1932 * 1933 * filemap_flush is used for the block device, so if there is a dirty 1934 * page for a block already in flight, we will not wait and start the 1935 * io over again 1936 */ 1937 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1938 { 1939 int ret = 0; 1940 if (!MSDOS_SB(sb)->options.flush) 1941 return 0; 1942 if (i1) 1943 ret = writeback_inode(i1); 1944 if (!ret && i2) 1945 ret = writeback_inode(i2); 1946 if (!ret) { 1947 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1948 ret = filemap_flush(mapping); 1949 } 1950 return ret; 1951 } 1952 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1953 1954 static int __init init_fat_fs(void) 1955 { 1956 int err; 1957 1958 err = fat_cache_init(); 1959 if (err) 1960 return err; 1961 1962 err = fat_init_inodecache(); 1963 if (err) 1964 goto failed; 1965 1966 return 0; 1967 1968 failed: 1969 fat_cache_destroy(); 1970 return err; 1971 } 1972 1973 static void __exit exit_fat_fs(void) 1974 { 1975 fat_cache_destroy(); 1976 fat_destroy_inodecache(); 1977 } 1978 1979 module_init(init_fat_fs) 1980 module_exit(exit_fat_fs) 1981 1982 MODULE_LICENSE("GPL"); 1983