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/iversion.h> 25 #include "fat.h" 26 27 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 28 /* if user don't select VFAT, this is undefined. */ 29 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 30 #endif 31 32 #define KB_IN_SECTORS 2 33 34 /* 35 * A deserialized copy of the on-disk structure laid out in struct 36 * fat_boot_sector. 37 */ 38 struct fat_bios_param_block { 39 u16 fat_sector_size; 40 u8 fat_sec_per_clus; 41 u16 fat_reserved; 42 u8 fat_fats; 43 u16 fat_dir_entries; 44 u16 fat_sectors; 45 u16 fat_fat_length; 46 u32 fat_total_sect; 47 48 u8 fat16_state; 49 u32 fat16_vol_id; 50 51 u32 fat32_length; 52 u32 fat32_root_cluster; 53 u16 fat32_info_sector; 54 u8 fat32_state; 55 u32 fat32_vol_id; 56 }; 57 58 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 59 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 60 61 static struct fat_floppy_defaults { 62 unsigned nr_sectors; 63 unsigned sec_per_clus; 64 unsigned dir_entries; 65 unsigned media; 66 unsigned fat_length; 67 } floppy_defaults[] = { 68 { 69 .nr_sectors = 160 * KB_IN_SECTORS, 70 .sec_per_clus = 1, 71 .dir_entries = 64, 72 .media = 0xFE, 73 .fat_length = 1, 74 }, 75 { 76 .nr_sectors = 180 * KB_IN_SECTORS, 77 .sec_per_clus = 1, 78 .dir_entries = 64, 79 .media = 0xFC, 80 .fat_length = 2, 81 }, 82 { 83 .nr_sectors = 320 * KB_IN_SECTORS, 84 .sec_per_clus = 2, 85 .dir_entries = 112, 86 .media = 0xFF, 87 .fat_length = 1, 88 }, 89 { 90 .nr_sectors = 360 * KB_IN_SECTORS, 91 .sec_per_clus = 2, 92 .dir_entries = 112, 93 .media = 0xFD, 94 .fat_length = 2, 95 }, 96 }; 97 98 int fat_add_cluster(struct inode *inode) 99 { 100 int err, cluster; 101 102 err = fat_alloc_clusters(inode, &cluster, 1); 103 if (err) 104 return err; 105 /* FIXME: this cluster should be added after data of this 106 * cluster is writed */ 107 err = fat_chain_add(inode, cluster, 1); 108 if (err) 109 fat_free_clusters(inode, cluster); 110 return err; 111 } 112 113 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 114 unsigned long *max_blocks, 115 struct buffer_head *bh_result, int create) 116 { 117 struct super_block *sb = inode->i_sb; 118 struct msdos_sb_info *sbi = MSDOS_SB(sb); 119 unsigned long mapped_blocks; 120 sector_t phys, last_block; 121 int err, offset; 122 123 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 124 if (err) 125 return err; 126 if (phys) { 127 map_bh(bh_result, sb, phys); 128 *max_blocks = min(mapped_blocks, *max_blocks); 129 return 0; 130 } 131 if (!create) 132 return 0; 133 134 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 135 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 136 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 137 return -EIO; 138 } 139 140 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); 141 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 142 /* 143 * allocate a cluster according to the following. 144 * 1) no more available blocks 145 * 2) not part of fallocate region 146 */ 147 if (!offset && !(iblock < last_block)) { 148 /* TODO: multiple cluster allocation would be desirable. */ 149 err = fat_add_cluster(inode); 150 if (err) 151 return err; 152 } 153 /* available blocks on this cluster */ 154 mapped_blocks = sbi->sec_per_clus - offset; 155 156 *max_blocks = min(mapped_blocks, *max_blocks); 157 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 158 159 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 160 if (err) 161 return err; 162 if (!phys) { 163 fat_fs_error(sb, 164 "invalid FAT chain (i_pos %lld, last_block %llu)", 165 MSDOS_I(inode)->i_pos, 166 (unsigned long long)last_block); 167 return -EIO; 168 } 169 170 BUG_ON(*max_blocks != mapped_blocks); 171 set_buffer_new(bh_result); 172 map_bh(bh_result, sb, phys); 173 174 return 0; 175 } 176 177 static int fat_get_block(struct inode *inode, sector_t iblock, 178 struct buffer_head *bh_result, int create) 179 { 180 struct super_block *sb = inode->i_sb; 181 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 182 int err; 183 184 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 185 if (err) 186 return err; 187 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 188 return 0; 189 } 190 191 static int fat_writepage(struct page *page, struct writeback_control *wbc) 192 { 193 return block_write_full_page(page, fat_get_block, wbc); 194 } 195 196 static int fat_writepages(struct address_space *mapping, 197 struct writeback_control *wbc) 198 { 199 return mpage_writepages(mapping, wbc, fat_get_block); 200 } 201 202 static int fat_readpage(struct file *file, struct page *page) 203 { 204 return mpage_readpage(page, fat_get_block); 205 } 206 207 static int fat_readpages(struct file *file, struct address_space *mapping, 208 struct list_head *pages, unsigned nr_pages) 209 { 210 return mpage_readpages(mapping, pages, nr_pages, fat_get_block); 211 } 212 213 static void fat_write_failed(struct address_space *mapping, loff_t to) 214 { 215 struct inode *inode = mapping->host; 216 217 if (to > inode->i_size) { 218 truncate_pagecache(inode, inode->i_size); 219 fat_truncate_blocks(inode, inode->i_size); 220 } 221 } 222 223 static int fat_write_begin(struct file *file, struct address_space *mapping, 224 loff_t pos, unsigned len, unsigned flags, 225 struct page **pagep, void **fsdata) 226 { 227 int err; 228 229 *pagep = NULL; 230 err = cont_write_begin(file, mapping, pos, len, flags, 231 pagep, fsdata, fat_get_block, 232 &MSDOS_I(mapping->host)->mmu_private); 233 if (err < 0) 234 fat_write_failed(mapping, pos + len); 235 return err; 236 } 237 238 static int fat_write_end(struct file *file, struct address_space *mapping, 239 loff_t pos, unsigned len, unsigned copied, 240 struct page *pagep, void *fsdata) 241 { 242 struct inode *inode = mapping->host; 243 int err; 244 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 245 if (err < len) 246 fat_write_failed(mapping, pos + len); 247 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 248 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 249 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 250 mark_inode_dirty(inode); 251 } 252 return err; 253 } 254 255 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 256 { 257 struct file *file = iocb->ki_filp; 258 struct address_space *mapping = file->f_mapping; 259 struct inode *inode = mapping->host; 260 size_t count = iov_iter_count(iter); 261 loff_t offset = iocb->ki_pos; 262 ssize_t ret; 263 264 if (iov_iter_rw(iter) == WRITE) { 265 /* 266 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 267 * so we need to update the ->mmu_private to block boundary. 268 * 269 * But we must fill the remaining area or hole by nul for 270 * updating ->mmu_private. 271 * 272 * Return 0, and fallback to normal buffered write. 273 */ 274 loff_t size = offset + count; 275 if (MSDOS_I(inode)->mmu_private < size) 276 return 0; 277 } 278 279 /* 280 * FAT need to use the DIO_LOCKING for avoiding the race 281 * condition of fat_get_block() and ->truncate(). 282 */ 283 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 284 if (ret < 0 && iov_iter_rw(iter) == WRITE) 285 fat_write_failed(mapping, offset + count); 286 287 return ret; 288 } 289 290 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 291 struct buffer_head *bh_result, int create) 292 { 293 struct super_block *sb = inode->i_sb; 294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 295 int err; 296 sector_t bmap; 297 unsigned long mapped_blocks; 298 299 BUG_ON(create != 0); 300 301 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 302 if (err) 303 return err; 304 305 if (bmap) { 306 map_bh(bh_result, sb, bmap); 307 max_blocks = min(mapped_blocks, max_blocks); 308 } 309 310 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 311 312 return 0; 313 } 314 315 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 316 { 317 sector_t blocknr; 318 319 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 320 down_read(&MSDOS_I(mapping->host)->truncate_lock); 321 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 322 up_read(&MSDOS_I(mapping->host)->truncate_lock); 323 324 return blocknr; 325 } 326 327 /* 328 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 329 * up to the end of the block which corresponds to `from'. 330 * This is required during truncate to physically zeroout the tail end 331 * of that block so it doesn't yield old data if the file is later grown. 332 * Also, avoid causing failure from fsx for cases of "data past EOF" 333 */ 334 int fat_block_truncate_page(struct inode *inode, loff_t from) 335 { 336 return block_truncate_page(inode->i_mapping, from, fat_get_block); 337 } 338 339 static const struct address_space_operations fat_aops = { 340 .readpage = fat_readpage, 341 .readpages = fat_readpages, 342 .writepage = fat_writepage, 343 .writepages = fat_writepages, 344 .write_begin = fat_write_begin, 345 .write_end = fat_write_end, 346 .direct_IO = fat_direct_IO, 347 .bmap = _fat_bmap 348 }; 349 350 /* 351 * New FAT inode stuff. We do the following: 352 * a) i_ino is constant and has nothing with on-disk location. 353 * b) FAT manages its own cache of directory entries. 354 * c) *This* cache is indexed by on-disk location. 355 * d) inode has an associated directory entry, all right, but 356 * it may be unhashed. 357 * e) currently entries are stored within struct inode. That should 358 * change. 359 * f) we deal with races in the following way: 360 * 1. readdir() and lookup() do FAT-dir-cache lookup. 361 * 2. rename() unhashes the F-d-c entry and rehashes it in 362 * a new place. 363 * 3. unlink() and rmdir() unhash F-d-c entry. 364 * 4. fat_write_inode() checks whether the thing is unhashed. 365 * If it is we silently return. If it isn't we do bread(), 366 * check if the location is still valid and retry if it 367 * isn't. Otherwise we do changes. 368 * 5. Spinlock is used to protect hash/unhash/location check/lookup 369 * 6. fat_evict_inode() unhashes the F-d-c entry. 370 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 371 * and consider negative result as cache miss. 372 */ 373 374 static void fat_hash_init(struct super_block *sb) 375 { 376 struct msdos_sb_info *sbi = MSDOS_SB(sb); 377 int i; 378 379 spin_lock_init(&sbi->inode_hash_lock); 380 for (i = 0; i < FAT_HASH_SIZE; i++) 381 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 382 } 383 384 static inline unsigned long fat_hash(loff_t i_pos) 385 { 386 return hash_32(i_pos, FAT_HASH_BITS); 387 } 388 389 static void dir_hash_init(struct super_block *sb) 390 { 391 struct msdos_sb_info *sbi = MSDOS_SB(sb); 392 int i; 393 394 spin_lock_init(&sbi->dir_hash_lock); 395 for (i = 0; i < FAT_HASH_SIZE; i++) 396 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 397 } 398 399 void fat_attach(struct inode *inode, loff_t i_pos) 400 { 401 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 402 403 if (inode->i_ino != MSDOS_ROOT_INO) { 404 struct hlist_head *head = sbi->inode_hashtable 405 + fat_hash(i_pos); 406 407 spin_lock(&sbi->inode_hash_lock); 408 MSDOS_I(inode)->i_pos = i_pos; 409 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 410 spin_unlock(&sbi->inode_hash_lock); 411 } 412 413 /* If NFS support is enabled, cache the mapping of start cluster 414 * to directory inode. This is used during reconnection of 415 * dentries to the filesystem root. 416 */ 417 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 418 struct hlist_head *d_head = sbi->dir_hashtable; 419 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 420 421 spin_lock(&sbi->dir_hash_lock); 422 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 423 spin_unlock(&sbi->dir_hash_lock); 424 } 425 } 426 EXPORT_SYMBOL_GPL(fat_attach); 427 428 void fat_detach(struct inode *inode) 429 { 430 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 431 spin_lock(&sbi->inode_hash_lock); 432 MSDOS_I(inode)->i_pos = 0; 433 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 434 spin_unlock(&sbi->inode_hash_lock); 435 436 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 437 spin_lock(&sbi->dir_hash_lock); 438 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 439 spin_unlock(&sbi->dir_hash_lock); 440 } 441 } 442 EXPORT_SYMBOL_GPL(fat_detach); 443 444 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 445 { 446 struct msdos_sb_info *sbi = MSDOS_SB(sb); 447 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 448 struct msdos_inode_info *i; 449 struct inode *inode = NULL; 450 451 spin_lock(&sbi->inode_hash_lock); 452 hlist_for_each_entry(i, head, i_fat_hash) { 453 BUG_ON(i->vfs_inode.i_sb != sb); 454 if (i->i_pos != i_pos) 455 continue; 456 inode = igrab(&i->vfs_inode); 457 if (inode) 458 break; 459 } 460 spin_unlock(&sbi->inode_hash_lock); 461 return inode; 462 } 463 464 static int is_exec(unsigned char *extension) 465 { 466 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 467 468 for (walk = exe_extensions; *walk; walk += 3) 469 if (!strncmp(extension, walk, 3)) 470 return 1; 471 return 0; 472 } 473 474 static int fat_calc_dir_size(struct inode *inode) 475 { 476 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 477 int ret, fclus, dclus; 478 479 inode->i_size = 0; 480 if (MSDOS_I(inode)->i_start == 0) 481 return 0; 482 483 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 484 if (ret < 0) 485 return ret; 486 inode->i_size = (fclus + 1) << sbi->cluster_bits; 487 488 return 0; 489 } 490 491 static int fat_validate_dir(struct inode *dir) 492 { 493 struct super_block *sb = dir->i_sb; 494 495 if (dir->i_nlink < 2) { 496 /* Directory should have "."/".." entries at least. */ 497 fat_fs_error(sb, "corrupted directory (invalid entries)"); 498 return -EIO; 499 } 500 if (MSDOS_I(dir)->i_start == 0 || 501 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 502 /* Directory should point valid cluster. */ 503 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 504 return -EIO; 505 } 506 return 0; 507 } 508 509 /* doesn't deal with root inode */ 510 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 511 { 512 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 513 int error; 514 515 MSDOS_I(inode)->i_pos = 0; 516 inode->i_uid = sbi->options.fs_uid; 517 inode->i_gid = sbi->options.fs_gid; 518 inode_inc_iversion(inode); 519 inode->i_generation = get_seconds(); 520 521 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 522 inode->i_generation &= ~1; 523 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 524 inode->i_op = sbi->dir_ops; 525 inode->i_fop = &fat_dir_operations; 526 527 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 528 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 529 error = fat_calc_dir_size(inode); 530 if (error < 0) 531 return error; 532 MSDOS_I(inode)->mmu_private = inode->i_size; 533 534 set_nlink(inode, fat_subdirs(inode)); 535 536 error = fat_validate_dir(inode); 537 if (error < 0) 538 return error; 539 } else { /* not a directory */ 540 inode->i_generation |= 1; 541 inode->i_mode = fat_make_mode(sbi, de->attr, 542 ((sbi->options.showexec && !is_exec(de->name + 8)) 543 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 544 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 545 546 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 547 inode->i_size = le32_to_cpu(de->size); 548 inode->i_op = &fat_file_inode_operations; 549 inode->i_fop = &fat_file_operations; 550 inode->i_mapping->a_ops = &fat_aops; 551 MSDOS_I(inode)->mmu_private = inode->i_size; 552 } 553 if (de->attr & ATTR_SYS) { 554 if (sbi->options.sys_immutable) 555 inode->i_flags |= S_IMMUTABLE; 556 } 557 fat_save_attrs(inode, de->attr); 558 559 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 560 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 561 562 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 563 if (sbi->options.isvfat) { 564 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 565 de->cdate, de->ctime_cs); 566 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 567 } else 568 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME); 569 570 return 0; 571 } 572 573 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 574 { 575 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 576 mutex_lock(&sbi->nfs_build_inode_lock); 577 } 578 579 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 580 { 581 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 582 mutex_unlock(&sbi->nfs_build_inode_lock); 583 } 584 585 struct inode *fat_build_inode(struct super_block *sb, 586 struct msdos_dir_entry *de, loff_t i_pos) 587 { 588 struct inode *inode; 589 int err; 590 591 fat_lock_build_inode(MSDOS_SB(sb)); 592 inode = fat_iget(sb, i_pos); 593 if (inode) 594 goto out; 595 inode = new_inode(sb); 596 if (!inode) { 597 inode = ERR_PTR(-ENOMEM); 598 goto out; 599 } 600 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 601 inode_set_iversion(inode, 1); 602 err = fat_fill_inode(inode, de); 603 if (err) { 604 iput(inode); 605 inode = ERR_PTR(err); 606 goto out; 607 } 608 fat_attach(inode, i_pos); 609 insert_inode_hash(inode); 610 out: 611 fat_unlock_build_inode(MSDOS_SB(sb)); 612 return inode; 613 } 614 615 EXPORT_SYMBOL_GPL(fat_build_inode); 616 617 static int __fat_write_inode(struct inode *inode, int wait); 618 619 static void fat_free_eofblocks(struct inode *inode) 620 { 621 /* Release unwritten fallocated blocks on inode eviction. */ 622 if ((inode->i_blocks << 9) > 623 round_up(MSDOS_I(inode)->mmu_private, 624 MSDOS_SB(inode->i_sb)->cluster_size)) { 625 int err; 626 627 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 628 /* Fallocate results in updating the i_start/iogstart 629 * for the zero byte file. So, make it return to 630 * original state during evict and commit it to avoid 631 * any corruption on the next access to the cluster 632 * chain for the file. 633 */ 634 err = __fat_write_inode(inode, inode_needs_sync(inode)); 635 if (err) { 636 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 637 "update on disk inode for unused " 638 "fallocated blocks, inode could be " 639 "corrupted. Please run fsck"); 640 } 641 642 } 643 } 644 645 static void fat_evict_inode(struct inode *inode) 646 { 647 truncate_inode_pages_final(&inode->i_data); 648 if (!inode->i_nlink) { 649 inode->i_size = 0; 650 fat_truncate_blocks(inode, 0); 651 } else 652 fat_free_eofblocks(inode); 653 654 invalidate_inode_buffers(inode); 655 clear_inode(inode); 656 fat_cache_inval_inode(inode); 657 fat_detach(inode); 658 } 659 660 static void fat_set_state(struct super_block *sb, 661 unsigned int set, unsigned int force) 662 { 663 struct buffer_head *bh; 664 struct fat_boot_sector *b; 665 struct msdos_sb_info *sbi = MSDOS_SB(sb); 666 667 /* do not change any thing if mounted read only */ 668 if (sb_rdonly(sb) && !force) 669 return; 670 671 /* do not change state if fs was dirty */ 672 if (sbi->dirty) { 673 /* warn only on set (mount). */ 674 if (set) 675 fat_msg(sb, KERN_WARNING, "Volume was not properly " 676 "unmounted. Some data may be corrupt. " 677 "Please run fsck."); 678 return; 679 } 680 681 bh = sb_bread(sb, 0); 682 if (bh == NULL) { 683 fat_msg(sb, KERN_ERR, "unable to read boot sector " 684 "to mark fs as dirty"); 685 return; 686 } 687 688 b = (struct fat_boot_sector *) bh->b_data; 689 690 if (is_fat32(sbi)) { 691 if (set) 692 b->fat32.state |= FAT_STATE_DIRTY; 693 else 694 b->fat32.state &= ~FAT_STATE_DIRTY; 695 } else /* fat 16 and 12 */ { 696 if (set) 697 b->fat16.state |= FAT_STATE_DIRTY; 698 else 699 b->fat16.state &= ~FAT_STATE_DIRTY; 700 } 701 702 mark_buffer_dirty(bh); 703 sync_dirty_buffer(bh); 704 brelse(bh); 705 } 706 707 static void fat_reset_iocharset(struct fat_mount_options *opts) 708 { 709 if (opts->iocharset != fat_default_iocharset) { 710 /* Note: opts->iocharset can be NULL here */ 711 kfree(opts->iocharset); 712 opts->iocharset = fat_default_iocharset; 713 } 714 } 715 716 static void delayed_free(struct rcu_head *p) 717 { 718 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 719 unload_nls(sbi->nls_disk); 720 unload_nls(sbi->nls_io); 721 fat_reset_iocharset(&sbi->options); 722 kfree(sbi); 723 } 724 725 static void fat_put_super(struct super_block *sb) 726 { 727 struct msdos_sb_info *sbi = MSDOS_SB(sb); 728 729 fat_set_state(sb, 0, 0); 730 731 iput(sbi->fsinfo_inode); 732 iput(sbi->fat_inode); 733 734 call_rcu(&sbi->rcu, delayed_free); 735 } 736 737 static struct kmem_cache *fat_inode_cachep; 738 739 static struct inode *fat_alloc_inode(struct super_block *sb) 740 { 741 struct msdos_inode_info *ei; 742 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 743 if (!ei) 744 return NULL; 745 746 init_rwsem(&ei->truncate_lock); 747 return &ei->vfs_inode; 748 } 749 750 static void fat_free_inode(struct inode *inode) 751 { 752 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 753 } 754 755 static void init_once(void *foo) 756 { 757 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 758 759 spin_lock_init(&ei->cache_lru_lock); 760 ei->nr_caches = 0; 761 ei->cache_valid_id = FAT_CACHE_VALID + 1; 762 INIT_LIST_HEAD(&ei->cache_lru); 763 INIT_HLIST_NODE(&ei->i_fat_hash); 764 INIT_HLIST_NODE(&ei->i_dir_hash); 765 inode_init_once(&ei->vfs_inode); 766 } 767 768 static int __init fat_init_inodecache(void) 769 { 770 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 771 sizeof(struct msdos_inode_info), 772 0, (SLAB_RECLAIM_ACCOUNT| 773 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 774 init_once); 775 if (fat_inode_cachep == NULL) 776 return -ENOMEM; 777 return 0; 778 } 779 780 static void __exit fat_destroy_inodecache(void) 781 { 782 /* 783 * Make sure all delayed rcu free inodes are flushed before we 784 * destroy cache. 785 */ 786 rcu_barrier(); 787 kmem_cache_destroy(fat_inode_cachep); 788 } 789 790 static int fat_remount(struct super_block *sb, int *flags, char *data) 791 { 792 bool new_rdonly; 793 struct msdos_sb_info *sbi = MSDOS_SB(sb); 794 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 795 796 sync_filesystem(sb); 797 798 /* make sure we update state on remount. */ 799 new_rdonly = *flags & SB_RDONLY; 800 if (new_rdonly != sb_rdonly(sb)) { 801 if (new_rdonly) 802 fat_set_state(sb, 0, 0); 803 else 804 fat_set_state(sb, 1, 1); 805 } 806 return 0; 807 } 808 809 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 810 { 811 struct super_block *sb = dentry->d_sb; 812 struct msdos_sb_info *sbi = MSDOS_SB(sb); 813 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 814 815 /* If the count of free cluster is still unknown, counts it here. */ 816 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 817 int err = fat_count_free_clusters(dentry->d_sb); 818 if (err) 819 return err; 820 } 821 822 buf->f_type = dentry->d_sb->s_magic; 823 buf->f_bsize = sbi->cluster_size; 824 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 825 buf->f_bfree = sbi->free_clusters; 826 buf->f_bavail = sbi->free_clusters; 827 buf->f_fsid.val[0] = (u32)id; 828 buf->f_fsid.val[1] = (u32)(id >> 32); 829 buf->f_namelen = 830 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 831 832 return 0; 833 } 834 835 static int __fat_write_inode(struct inode *inode, int wait) 836 { 837 struct super_block *sb = inode->i_sb; 838 struct msdos_sb_info *sbi = MSDOS_SB(sb); 839 struct buffer_head *bh; 840 struct msdos_dir_entry *raw_entry; 841 loff_t i_pos; 842 sector_t blocknr; 843 int err, offset; 844 845 if (inode->i_ino == MSDOS_ROOT_INO) 846 return 0; 847 848 retry: 849 i_pos = fat_i_pos_read(sbi, inode); 850 if (!i_pos) 851 return 0; 852 853 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 854 bh = sb_bread(sb, blocknr); 855 if (!bh) { 856 fat_msg(sb, KERN_ERR, "unable to read inode block " 857 "for updating (i_pos %lld)", i_pos); 858 return -EIO; 859 } 860 spin_lock(&sbi->inode_hash_lock); 861 if (i_pos != MSDOS_I(inode)->i_pos) { 862 spin_unlock(&sbi->inode_hash_lock); 863 brelse(bh); 864 goto retry; 865 } 866 867 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 868 if (S_ISDIR(inode->i_mode)) 869 raw_entry->size = 0; 870 else 871 raw_entry->size = cpu_to_le32(inode->i_size); 872 raw_entry->attr = fat_make_attrs(inode); 873 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 874 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 875 &raw_entry->date, NULL); 876 if (sbi->options.isvfat) { 877 __le16 atime; 878 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 879 &raw_entry->cdate, &raw_entry->ctime_cs); 880 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 881 &raw_entry->adate, NULL); 882 } 883 spin_unlock(&sbi->inode_hash_lock); 884 mark_buffer_dirty(bh); 885 err = 0; 886 if (wait) 887 err = sync_dirty_buffer(bh); 888 brelse(bh); 889 return err; 890 } 891 892 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 893 { 894 int err; 895 896 if (inode->i_ino == MSDOS_FSINFO_INO) { 897 struct super_block *sb = inode->i_sb; 898 899 mutex_lock(&MSDOS_SB(sb)->s_lock); 900 err = fat_clusters_flush(sb); 901 mutex_unlock(&MSDOS_SB(sb)->s_lock); 902 } else 903 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 904 905 return err; 906 } 907 908 int fat_sync_inode(struct inode *inode) 909 { 910 return __fat_write_inode(inode, 1); 911 } 912 913 EXPORT_SYMBOL_GPL(fat_sync_inode); 914 915 static int fat_show_options(struct seq_file *m, struct dentry *root); 916 static const struct super_operations fat_sops = { 917 .alloc_inode = fat_alloc_inode, 918 .free_inode = fat_free_inode, 919 .write_inode = fat_write_inode, 920 .evict_inode = fat_evict_inode, 921 .put_super = fat_put_super, 922 .statfs = fat_statfs, 923 .remount_fs = fat_remount, 924 925 .show_options = fat_show_options, 926 }; 927 928 static int fat_show_options(struct seq_file *m, struct dentry *root) 929 { 930 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 931 struct fat_mount_options *opts = &sbi->options; 932 int isvfat = opts->isvfat; 933 934 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 935 seq_printf(m, ",uid=%u", 936 from_kuid_munged(&init_user_ns, opts->fs_uid)); 937 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 938 seq_printf(m, ",gid=%u", 939 from_kgid_munged(&init_user_ns, opts->fs_gid)); 940 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 941 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 942 if (opts->allow_utime) 943 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 944 if (sbi->nls_disk) 945 /* strip "cp" prefix from displayed option */ 946 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 947 if (isvfat) { 948 if (sbi->nls_io) 949 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 950 951 switch (opts->shortname) { 952 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 953 seq_puts(m, ",shortname=win95"); 954 break; 955 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 956 seq_puts(m, ",shortname=winnt"); 957 break; 958 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 959 seq_puts(m, ",shortname=mixed"); 960 break; 961 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 962 seq_puts(m, ",shortname=lower"); 963 break; 964 default: 965 seq_puts(m, ",shortname=unknown"); 966 break; 967 } 968 } 969 if (opts->name_check != 'n') 970 seq_printf(m, ",check=%c", opts->name_check); 971 if (opts->usefree) 972 seq_puts(m, ",usefree"); 973 if (opts->quiet) 974 seq_puts(m, ",quiet"); 975 if (opts->showexec) 976 seq_puts(m, ",showexec"); 977 if (opts->sys_immutable) 978 seq_puts(m, ",sys_immutable"); 979 if (!isvfat) { 980 if (opts->dotsOK) 981 seq_puts(m, ",dotsOK=yes"); 982 if (opts->nocase) 983 seq_puts(m, ",nocase"); 984 } else { 985 if (opts->utf8) 986 seq_puts(m, ",utf8"); 987 if (opts->unicode_xlate) 988 seq_puts(m, ",uni_xlate"); 989 if (!opts->numtail) 990 seq_puts(m, ",nonumtail"); 991 if (opts->rodir) 992 seq_puts(m, ",rodir"); 993 } 994 if (opts->flush) 995 seq_puts(m, ",flush"); 996 if (opts->tz_set) { 997 if (opts->time_offset) 998 seq_printf(m, ",time_offset=%d", opts->time_offset); 999 else 1000 seq_puts(m, ",tz=UTC"); 1001 } 1002 if (opts->errors == FAT_ERRORS_CONT) 1003 seq_puts(m, ",errors=continue"); 1004 else if (opts->errors == FAT_ERRORS_PANIC) 1005 seq_puts(m, ",errors=panic"); 1006 else 1007 seq_puts(m, ",errors=remount-ro"); 1008 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1009 seq_puts(m, ",nfs=nostale_ro"); 1010 else if (opts->nfs) 1011 seq_puts(m, ",nfs=stale_rw"); 1012 if (opts->discard) 1013 seq_puts(m, ",discard"); 1014 if (opts->dos1xfloppy) 1015 seq_puts(m, ",dos1xfloppy"); 1016 1017 return 0; 1018 } 1019 1020 enum { 1021 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1022 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1023 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1024 Opt_immutable, Opt_dots, Opt_nodots, 1025 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1026 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1027 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1028 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1029 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1030 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1031 }; 1032 1033 static const match_table_t fat_tokens = { 1034 {Opt_check_r, "check=relaxed"}, 1035 {Opt_check_s, "check=strict"}, 1036 {Opt_check_n, "check=normal"}, 1037 {Opt_check_r, "check=r"}, 1038 {Opt_check_s, "check=s"}, 1039 {Opt_check_n, "check=n"}, 1040 {Opt_uid, "uid=%u"}, 1041 {Opt_gid, "gid=%u"}, 1042 {Opt_umask, "umask=%o"}, 1043 {Opt_dmask, "dmask=%o"}, 1044 {Opt_fmask, "fmask=%o"}, 1045 {Opt_allow_utime, "allow_utime=%o"}, 1046 {Opt_codepage, "codepage=%u"}, 1047 {Opt_usefree, "usefree"}, 1048 {Opt_nocase, "nocase"}, 1049 {Opt_quiet, "quiet"}, 1050 {Opt_showexec, "showexec"}, 1051 {Opt_debug, "debug"}, 1052 {Opt_immutable, "sys_immutable"}, 1053 {Opt_flush, "flush"}, 1054 {Opt_tz_utc, "tz=UTC"}, 1055 {Opt_time_offset, "time_offset=%d"}, 1056 {Opt_err_cont, "errors=continue"}, 1057 {Opt_err_panic, "errors=panic"}, 1058 {Opt_err_ro, "errors=remount-ro"}, 1059 {Opt_discard, "discard"}, 1060 {Opt_nfs_stale_rw, "nfs"}, 1061 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1062 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1063 {Opt_dos1xfloppy, "dos1xfloppy"}, 1064 {Opt_obsolete, "conv=binary"}, 1065 {Opt_obsolete, "conv=text"}, 1066 {Opt_obsolete, "conv=auto"}, 1067 {Opt_obsolete, "conv=b"}, 1068 {Opt_obsolete, "conv=t"}, 1069 {Opt_obsolete, "conv=a"}, 1070 {Opt_obsolete, "fat=%u"}, 1071 {Opt_obsolete, "blocksize=%u"}, 1072 {Opt_obsolete, "cvf_format=%20s"}, 1073 {Opt_obsolete, "cvf_options=%100s"}, 1074 {Opt_obsolete, "posix"}, 1075 {Opt_err, NULL}, 1076 }; 1077 static const match_table_t msdos_tokens = { 1078 {Opt_nodots, "nodots"}, 1079 {Opt_nodots, "dotsOK=no"}, 1080 {Opt_dots, "dots"}, 1081 {Opt_dots, "dotsOK=yes"}, 1082 {Opt_err, NULL} 1083 }; 1084 static const match_table_t vfat_tokens = { 1085 {Opt_charset, "iocharset=%s"}, 1086 {Opt_shortname_lower, "shortname=lower"}, 1087 {Opt_shortname_win95, "shortname=win95"}, 1088 {Opt_shortname_winnt, "shortname=winnt"}, 1089 {Opt_shortname_mixed, "shortname=mixed"}, 1090 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1091 {Opt_utf8_no, "utf8=no"}, 1092 {Opt_utf8_no, "utf8=false"}, 1093 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1094 {Opt_utf8_yes, "utf8=yes"}, 1095 {Opt_utf8_yes, "utf8=true"}, 1096 {Opt_utf8_yes, "utf8"}, 1097 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1098 {Opt_uni_xl_no, "uni_xlate=no"}, 1099 {Opt_uni_xl_no, "uni_xlate=false"}, 1100 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1101 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1102 {Opt_uni_xl_yes, "uni_xlate=true"}, 1103 {Opt_uni_xl_yes, "uni_xlate"}, 1104 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1105 {Opt_nonumtail_no, "nonumtail=no"}, 1106 {Opt_nonumtail_no, "nonumtail=false"}, 1107 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1108 {Opt_nonumtail_yes, "nonumtail=yes"}, 1109 {Opt_nonumtail_yes, "nonumtail=true"}, 1110 {Opt_nonumtail_yes, "nonumtail"}, 1111 {Opt_rodir, "rodir"}, 1112 {Opt_err, NULL} 1113 }; 1114 1115 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1116 int silent, int *debug, struct fat_mount_options *opts) 1117 { 1118 char *p; 1119 substring_t args[MAX_OPT_ARGS]; 1120 int option; 1121 char *iocharset; 1122 1123 opts->isvfat = is_vfat; 1124 1125 opts->fs_uid = current_uid(); 1126 opts->fs_gid = current_gid(); 1127 opts->fs_fmask = opts->fs_dmask = current_umask(); 1128 opts->allow_utime = -1; 1129 opts->codepage = fat_default_codepage; 1130 fat_reset_iocharset(opts); 1131 if (is_vfat) { 1132 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1133 opts->rodir = 0; 1134 } else { 1135 opts->shortname = 0; 1136 opts->rodir = 1; 1137 } 1138 opts->name_check = 'n'; 1139 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1140 opts->unicode_xlate = 0; 1141 opts->numtail = 1; 1142 opts->usefree = opts->nocase = 0; 1143 opts->tz_set = 0; 1144 opts->nfs = 0; 1145 opts->errors = FAT_ERRORS_RO; 1146 *debug = 0; 1147 1148 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1149 1150 if (!options) 1151 goto out; 1152 1153 while ((p = strsep(&options, ",")) != NULL) { 1154 int token; 1155 if (!*p) 1156 continue; 1157 1158 token = match_token(p, fat_tokens, args); 1159 if (token == Opt_err) { 1160 if (is_vfat) 1161 token = match_token(p, vfat_tokens, args); 1162 else 1163 token = match_token(p, msdos_tokens, args); 1164 } 1165 switch (token) { 1166 case Opt_check_s: 1167 opts->name_check = 's'; 1168 break; 1169 case Opt_check_r: 1170 opts->name_check = 'r'; 1171 break; 1172 case Opt_check_n: 1173 opts->name_check = 'n'; 1174 break; 1175 case Opt_usefree: 1176 opts->usefree = 1; 1177 break; 1178 case Opt_nocase: 1179 if (!is_vfat) 1180 opts->nocase = 1; 1181 else { 1182 /* for backward compatibility */ 1183 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1184 | VFAT_SFN_CREATE_WIN95; 1185 } 1186 break; 1187 case Opt_quiet: 1188 opts->quiet = 1; 1189 break; 1190 case Opt_showexec: 1191 opts->showexec = 1; 1192 break; 1193 case Opt_debug: 1194 *debug = 1; 1195 break; 1196 case Opt_immutable: 1197 opts->sys_immutable = 1; 1198 break; 1199 case Opt_uid: 1200 if (match_int(&args[0], &option)) 1201 return -EINVAL; 1202 opts->fs_uid = make_kuid(current_user_ns(), option); 1203 if (!uid_valid(opts->fs_uid)) 1204 return -EINVAL; 1205 break; 1206 case Opt_gid: 1207 if (match_int(&args[0], &option)) 1208 return -EINVAL; 1209 opts->fs_gid = make_kgid(current_user_ns(), option); 1210 if (!gid_valid(opts->fs_gid)) 1211 return -EINVAL; 1212 break; 1213 case Opt_umask: 1214 if (match_octal(&args[0], &option)) 1215 return -EINVAL; 1216 opts->fs_fmask = opts->fs_dmask = option; 1217 break; 1218 case Opt_dmask: 1219 if (match_octal(&args[0], &option)) 1220 return -EINVAL; 1221 opts->fs_dmask = option; 1222 break; 1223 case Opt_fmask: 1224 if (match_octal(&args[0], &option)) 1225 return -EINVAL; 1226 opts->fs_fmask = option; 1227 break; 1228 case Opt_allow_utime: 1229 if (match_octal(&args[0], &option)) 1230 return -EINVAL; 1231 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1232 break; 1233 case Opt_codepage: 1234 if (match_int(&args[0], &option)) 1235 return -EINVAL; 1236 opts->codepage = option; 1237 break; 1238 case Opt_flush: 1239 opts->flush = 1; 1240 break; 1241 case Opt_time_offset: 1242 if (match_int(&args[0], &option)) 1243 return -EINVAL; 1244 /* 1245 * GMT+-12 zones may have DST corrections so at least 1246 * 13 hours difference is needed. Make the limit 24 1247 * just in case someone invents something unusual. 1248 */ 1249 if (option < -24 * 60 || option > 24 * 60) 1250 return -EINVAL; 1251 opts->tz_set = 1; 1252 opts->time_offset = option; 1253 break; 1254 case Opt_tz_utc: 1255 opts->tz_set = 1; 1256 opts->time_offset = 0; 1257 break; 1258 case Opt_err_cont: 1259 opts->errors = FAT_ERRORS_CONT; 1260 break; 1261 case Opt_err_panic: 1262 opts->errors = FAT_ERRORS_PANIC; 1263 break; 1264 case Opt_err_ro: 1265 opts->errors = FAT_ERRORS_RO; 1266 break; 1267 case Opt_nfs_stale_rw: 1268 opts->nfs = FAT_NFS_STALE_RW; 1269 break; 1270 case Opt_nfs_nostale_ro: 1271 opts->nfs = FAT_NFS_NOSTALE_RO; 1272 break; 1273 case Opt_dos1xfloppy: 1274 opts->dos1xfloppy = 1; 1275 break; 1276 1277 /* msdos specific */ 1278 case Opt_dots: 1279 opts->dotsOK = 1; 1280 break; 1281 case Opt_nodots: 1282 opts->dotsOK = 0; 1283 break; 1284 1285 /* vfat specific */ 1286 case Opt_charset: 1287 fat_reset_iocharset(opts); 1288 iocharset = match_strdup(&args[0]); 1289 if (!iocharset) 1290 return -ENOMEM; 1291 opts->iocharset = iocharset; 1292 break; 1293 case Opt_shortname_lower: 1294 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1295 | VFAT_SFN_CREATE_WIN95; 1296 break; 1297 case Opt_shortname_win95: 1298 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1299 | VFAT_SFN_CREATE_WIN95; 1300 break; 1301 case Opt_shortname_winnt: 1302 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1303 | VFAT_SFN_CREATE_WINNT; 1304 break; 1305 case Opt_shortname_mixed: 1306 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1307 | VFAT_SFN_CREATE_WIN95; 1308 break; 1309 case Opt_utf8_no: /* 0 or no or false */ 1310 opts->utf8 = 0; 1311 break; 1312 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1313 opts->utf8 = 1; 1314 break; 1315 case Opt_uni_xl_no: /* 0 or no or false */ 1316 opts->unicode_xlate = 0; 1317 break; 1318 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1319 opts->unicode_xlate = 1; 1320 break; 1321 case Opt_nonumtail_no: /* 0 or no or false */ 1322 opts->numtail = 1; /* negated option */ 1323 break; 1324 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1325 opts->numtail = 0; /* negated option */ 1326 break; 1327 case Opt_rodir: 1328 opts->rodir = 1; 1329 break; 1330 case Opt_discard: 1331 opts->discard = 1; 1332 break; 1333 1334 /* obsolete mount options */ 1335 case Opt_obsolete: 1336 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1337 "not supported now", p); 1338 break; 1339 /* unknown option */ 1340 default: 1341 if (!silent) { 1342 fat_msg(sb, KERN_ERR, 1343 "Unrecognized mount option \"%s\" " 1344 "or missing value", p); 1345 } 1346 return -EINVAL; 1347 } 1348 } 1349 1350 out: 1351 /* UTF-8 doesn't provide FAT semantics */ 1352 if (!strcmp(opts->iocharset, "utf8")) { 1353 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1354 " for FAT filesystems, filesystem will be " 1355 "case sensitive!"); 1356 } 1357 1358 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1359 if (opts->allow_utime == (unsigned short)-1) 1360 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1361 if (opts->unicode_xlate) 1362 opts->utf8 = 0; 1363 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1364 sb->s_flags |= SB_RDONLY; 1365 sb->s_export_op = &fat_export_ops_nostale; 1366 } 1367 1368 return 0; 1369 } 1370 1371 static void fat_dummy_inode_init(struct inode *inode) 1372 { 1373 /* Initialize this dummy inode to work as no-op. */ 1374 MSDOS_I(inode)->mmu_private = 0; 1375 MSDOS_I(inode)->i_start = 0; 1376 MSDOS_I(inode)->i_logstart = 0; 1377 MSDOS_I(inode)->i_attrs = 0; 1378 MSDOS_I(inode)->i_pos = 0; 1379 } 1380 1381 static int fat_read_root(struct inode *inode) 1382 { 1383 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1384 int error; 1385 1386 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1387 inode->i_uid = sbi->options.fs_uid; 1388 inode->i_gid = sbi->options.fs_gid; 1389 inode_inc_iversion(inode); 1390 inode->i_generation = 0; 1391 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1392 inode->i_op = sbi->dir_ops; 1393 inode->i_fop = &fat_dir_operations; 1394 if (is_fat32(sbi)) { 1395 MSDOS_I(inode)->i_start = sbi->root_cluster; 1396 error = fat_calc_dir_size(inode); 1397 if (error < 0) 1398 return error; 1399 } else { 1400 MSDOS_I(inode)->i_start = 0; 1401 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1402 } 1403 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1404 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1405 MSDOS_I(inode)->i_logstart = 0; 1406 MSDOS_I(inode)->mmu_private = inode->i_size; 1407 1408 fat_save_attrs(inode, ATTR_DIR); 1409 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1410 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1411 set_nlink(inode, fat_subdirs(inode)+2); 1412 1413 return 0; 1414 } 1415 1416 static unsigned long calc_fat_clusters(struct super_block *sb) 1417 { 1418 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1419 1420 /* Divide first to avoid overflow */ 1421 if (!is_fat12(sbi)) { 1422 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1423 return ent_per_sec * sbi->fat_length; 1424 } 1425 1426 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1427 } 1428 1429 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1430 { 1431 if (get_unaligned_le16(&b->sector_size)) 1432 return false; 1433 if (b->sec_per_clus) 1434 return false; 1435 if (b->reserved) 1436 return false; 1437 if (b->fats) 1438 return false; 1439 if (get_unaligned_le16(&b->dir_entries)) 1440 return false; 1441 if (get_unaligned_le16(&b->sectors)) 1442 return false; 1443 if (b->media) 1444 return false; 1445 if (b->fat_length) 1446 return false; 1447 if (b->secs_track) 1448 return false; 1449 if (b->heads) 1450 return false; 1451 return true; 1452 } 1453 1454 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1455 int silent, struct fat_bios_param_block *bpb) 1456 { 1457 int error = -EINVAL; 1458 1459 /* Read in BPB ... */ 1460 memset(bpb, 0, sizeof(*bpb)); 1461 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1462 bpb->fat_sec_per_clus = b->sec_per_clus; 1463 bpb->fat_reserved = le16_to_cpu(b->reserved); 1464 bpb->fat_fats = b->fats; 1465 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1466 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1467 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1468 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1469 1470 bpb->fat16_state = b->fat16.state; 1471 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1472 1473 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1474 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1475 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1476 bpb->fat32_state = b->fat32.state; 1477 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1478 1479 /* Validate this looks like a FAT filesystem BPB */ 1480 if (!bpb->fat_reserved) { 1481 if (!silent) 1482 fat_msg(sb, KERN_ERR, 1483 "bogus number of reserved sectors"); 1484 goto out; 1485 } 1486 if (!bpb->fat_fats) { 1487 if (!silent) 1488 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1489 goto out; 1490 } 1491 1492 /* 1493 * Earlier we checked here that b->secs_track and b->head are nonzero, 1494 * but it turns out valid FAT filesystems can have zero there. 1495 */ 1496 1497 if (!fat_valid_media(b->media)) { 1498 if (!silent) 1499 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1500 (unsigned)b->media); 1501 goto out; 1502 } 1503 1504 if (!is_power_of_2(bpb->fat_sector_size) 1505 || (bpb->fat_sector_size < 512) 1506 || (bpb->fat_sector_size > 4096)) { 1507 if (!silent) 1508 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1509 (unsigned)bpb->fat_sector_size); 1510 goto out; 1511 } 1512 1513 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1514 if (!silent) 1515 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1516 (unsigned)bpb->fat_sec_per_clus); 1517 goto out; 1518 } 1519 1520 error = 0; 1521 1522 out: 1523 return error; 1524 } 1525 1526 static int fat_read_static_bpb(struct super_block *sb, 1527 struct fat_boot_sector *b, int silent, 1528 struct fat_bios_param_block *bpb) 1529 { 1530 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1531 1532 struct fat_floppy_defaults *fdefaults = NULL; 1533 int error = -EINVAL; 1534 sector_t bd_sects; 1535 unsigned i; 1536 1537 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1538 1539 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1540 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1541 if (!silent) 1542 fat_msg(sb, KERN_ERR, 1543 "%s; no bootstrapping code", notdos1x); 1544 goto out; 1545 } 1546 1547 /* 1548 * If any value in this region is non-zero, it isn't archaic 1549 * DOS. 1550 */ 1551 if (!fat_bpb_is_zero(b)) { 1552 if (!silent) 1553 fat_msg(sb, KERN_ERR, 1554 "%s; DOS 2.x BPB is non-zero", notdos1x); 1555 goto out; 1556 } 1557 1558 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1559 if (floppy_defaults[i].nr_sectors == bd_sects) { 1560 fdefaults = &floppy_defaults[i]; 1561 break; 1562 } 1563 } 1564 1565 if (fdefaults == NULL) { 1566 if (!silent) 1567 fat_msg(sb, KERN_WARNING, 1568 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1569 (u64)bd_sects); 1570 goto out; 1571 } 1572 1573 if (!silent) 1574 fat_msg(sb, KERN_INFO, 1575 "This looks like a DOS 1.x volume; assuming default BPB values"); 1576 1577 memset(bpb, 0, sizeof(*bpb)); 1578 bpb->fat_sector_size = SECTOR_SIZE; 1579 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1580 bpb->fat_reserved = 1; 1581 bpb->fat_fats = 2; 1582 bpb->fat_dir_entries = fdefaults->dir_entries; 1583 bpb->fat_sectors = fdefaults->nr_sectors; 1584 bpb->fat_fat_length = fdefaults->fat_length; 1585 1586 error = 0; 1587 1588 out: 1589 return error; 1590 } 1591 1592 /* 1593 * Read the super block of an MS-DOS FS. 1594 */ 1595 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1596 void (*setup)(struct super_block *)) 1597 { 1598 struct inode *root_inode = NULL, *fat_inode = NULL; 1599 struct inode *fsinfo_inode = NULL; 1600 struct buffer_head *bh; 1601 struct fat_bios_param_block bpb; 1602 struct msdos_sb_info *sbi; 1603 u16 logical_sector_size; 1604 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1605 int debug; 1606 long error; 1607 char buf[50]; 1608 1609 /* 1610 * GFP_KERNEL is ok here, because while we do hold the 1611 * superblock lock, memory pressure can't call back into 1612 * the filesystem, since we're only just about to mount 1613 * it and have no inodes etc active! 1614 */ 1615 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1616 if (!sbi) 1617 return -ENOMEM; 1618 sb->s_fs_info = sbi; 1619 1620 sb->s_flags |= SB_NODIRATIME; 1621 sb->s_magic = MSDOS_SUPER_MAGIC; 1622 sb->s_op = &fat_sops; 1623 sb->s_export_op = &fat_export_ops; 1624 /* 1625 * fat timestamps are complex and truncated by fat itself, so 1626 * we set 1 here to be fast 1627 */ 1628 sb->s_time_gran = 1; 1629 mutex_init(&sbi->nfs_build_inode_lock); 1630 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1631 DEFAULT_RATELIMIT_BURST); 1632 1633 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1634 if (error) 1635 goto out_fail; 1636 1637 setup(sb); /* flavour-specific stuff that needs options */ 1638 1639 error = -EIO; 1640 sb_min_blocksize(sb, 512); 1641 bh = sb_bread(sb, 0); 1642 if (bh == NULL) { 1643 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1644 goto out_fail; 1645 } 1646 1647 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1648 &bpb); 1649 if (error == -EINVAL && sbi->options.dos1xfloppy) 1650 error = fat_read_static_bpb(sb, 1651 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1652 brelse(bh); 1653 1654 if (error == -EINVAL) 1655 goto out_invalid; 1656 else if (error) 1657 goto out_fail; 1658 1659 logical_sector_size = bpb.fat_sector_size; 1660 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1661 1662 error = -EIO; 1663 if (logical_sector_size < sb->s_blocksize) { 1664 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1665 " (logical sector size = %u)", logical_sector_size); 1666 goto out_fail; 1667 } 1668 1669 if (logical_sector_size > sb->s_blocksize) { 1670 struct buffer_head *bh_resize; 1671 1672 if (!sb_set_blocksize(sb, logical_sector_size)) { 1673 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1674 logical_sector_size); 1675 goto out_fail; 1676 } 1677 1678 /* Verify that the larger boot sector is fully readable */ 1679 bh_resize = sb_bread(sb, 0); 1680 if (bh_resize == NULL) { 1681 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1682 " (logical sector size = %lu)", 1683 sb->s_blocksize); 1684 goto out_fail; 1685 } 1686 brelse(bh_resize); 1687 } 1688 1689 mutex_init(&sbi->s_lock); 1690 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1691 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1692 sbi->fats = bpb.fat_fats; 1693 sbi->fat_bits = 0; /* Don't know yet */ 1694 sbi->fat_start = bpb.fat_reserved; 1695 sbi->fat_length = bpb.fat_fat_length; 1696 sbi->root_cluster = 0; 1697 sbi->free_clusters = -1; /* Don't know yet */ 1698 sbi->free_clus_valid = 0; 1699 sbi->prev_free = FAT_START_ENT; 1700 sb->s_maxbytes = 0xffffffff; 1701 1702 if (!sbi->fat_length && bpb.fat32_length) { 1703 struct fat_boot_fsinfo *fsinfo; 1704 struct buffer_head *fsinfo_bh; 1705 1706 /* Must be FAT32 */ 1707 sbi->fat_bits = 32; 1708 sbi->fat_length = bpb.fat32_length; 1709 sbi->root_cluster = bpb.fat32_root_cluster; 1710 1711 /* MC - if info_sector is 0, don't multiply by 0 */ 1712 sbi->fsinfo_sector = bpb.fat32_info_sector; 1713 if (sbi->fsinfo_sector == 0) 1714 sbi->fsinfo_sector = 1; 1715 1716 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1717 if (fsinfo_bh == NULL) { 1718 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1719 " (sector = %lu)", sbi->fsinfo_sector); 1720 goto out_fail; 1721 } 1722 1723 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1724 if (!IS_FSINFO(fsinfo)) { 1725 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1726 "0x%08x, 0x%08x (sector = %lu)", 1727 le32_to_cpu(fsinfo->signature1), 1728 le32_to_cpu(fsinfo->signature2), 1729 sbi->fsinfo_sector); 1730 } else { 1731 if (sbi->options.usefree) 1732 sbi->free_clus_valid = 1; 1733 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1734 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1735 } 1736 1737 brelse(fsinfo_bh); 1738 } 1739 1740 /* interpret volume ID as a little endian 32 bit integer */ 1741 if (is_fat32(sbi)) 1742 sbi->vol_id = bpb.fat32_vol_id; 1743 else /* fat 16 or 12 */ 1744 sbi->vol_id = bpb.fat16_vol_id; 1745 1746 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1747 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1748 1749 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1750 sbi->dir_entries = bpb.fat_dir_entries; 1751 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1752 if (!silent) 1753 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1754 " (%u)", sbi->dir_entries); 1755 goto out_invalid; 1756 } 1757 1758 rootdir_sectors = sbi->dir_entries 1759 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1760 sbi->data_start = sbi->dir_start + rootdir_sectors; 1761 total_sectors = bpb.fat_sectors; 1762 if (total_sectors == 0) 1763 total_sectors = bpb.fat_total_sect; 1764 1765 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1766 1767 if (!is_fat32(sbi)) 1768 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1769 1770 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1771 if (is_fat32(sbi)) 1772 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1773 else /* fat 16 or 12 */ 1774 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1775 1776 /* check that FAT table does not overflow */ 1777 fat_clusters = calc_fat_clusters(sb); 1778 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1779 if (total_clusters > max_fat(sb)) { 1780 if (!silent) 1781 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1782 total_clusters); 1783 goto out_invalid; 1784 } 1785 1786 sbi->max_cluster = total_clusters + FAT_START_ENT; 1787 /* check the free_clusters, it's not necessarily correct */ 1788 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1789 sbi->free_clusters = -1; 1790 /* check the prev_free, it's not necessarily correct */ 1791 sbi->prev_free %= sbi->max_cluster; 1792 if (sbi->prev_free < FAT_START_ENT) 1793 sbi->prev_free = FAT_START_ENT; 1794 1795 /* set up enough so that it can read an inode */ 1796 fat_hash_init(sb); 1797 dir_hash_init(sb); 1798 fat_ent_access_init(sb); 1799 1800 /* 1801 * The low byte of the first FAT entry must have the same value as 1802 * the media field of the boot sector. But in real world, too many 1803 * devices are writing wrong values. So, removed that validity check. 1804 * 1805 * The removed check compared the first FAT entry to a value dependent 1806 * on the media field like this: 1807 * == (0x0F00 | media), for FAT12 1808 * == (0XFF00 | media), for FAT16 1809 * == (0x0FFFFF | media), for FAT32 1810 */ 1811 1812 error = -EINVAL; 1813 sprintf(buf, "cp%d", sbi->options.codepage); 1814 sbi->nls_disk = load_nls(buf); 1815 if (!sbi->nls_disk) { 1816 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1817 goto out_fail; 1818 } 1819 1820 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1821 if (sbi->options.isvfat) { 1822 sbi->nls_io = load_nls(sbi->options.iocharset); 1823 if (!sbi->nls_io) { 1824 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1825 sbi->options.iocharset); 1826 goto out_fail; 1827 } 1828 } 1829 1830 error = -ENOMEM; 1831 fat_inode = new_inode(sb); 1832 if (!fat_inode) 1833 goto out_fail; 1834 fat_dummy_inode_init(fat_inode); 1835 sbi->fat_inode = fat_inode; 1836 1837 fsinfo_inode = new_inode(sb); 1838 if (!fsinfo_inode) 1839 goto out_fail; 1840 fat_dummy_inode_init(fsinfo_inode); 1841 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1842 sbi->fsinfo_inode = fsinfo_inode; 1843 insert_inode_hash(fsinfo_inode); 1844 1845 root_inode = new_inode(sb); 1846 if (!root_inode) 1847 goto out_fail; 1848 root_inode->i_ino = MSDOS_ROOT_INO; 1849 inode_set_iversion(root_inode, 1); 1850 error = fat_read_root(root_inode); 1851 if (error < 0) { 1852 iput(root_inode); 1853 goto out_fail; 1854 } 1855 error = -ENOMEM; 1856 insert_inode_hash(root_inode); 1857 fat_attach(root_inode, 0); 1858 sb->s_root = d_make_root(root_inode); 1859 if (!sb->s_root) { 1860 fat_msg(sb, KERN_ERR, "get root inode failed"); 1861 goto out_fail; 1862 } 1863 1864 if (sbi->options.discard) { 1865 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1866 if (!blk_queue_discard(q)) 1867 fat_msg(sb, KERN_WARNING, 1868 "mounting with \"discard\" option, but " 1869 "the device does not support discard"); 1870 } 1871 1872 fat_set_state(sb, 1, 0); 1873 return 0; 1874 1875 out_invalid: 1876 error = -EINVAL; 1877 if (!silent) 1878 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1879 1880 out_fail: 1881 if (fsinfo_inode) 1882 iput(fsinfo_inode); 1883 if (fat_inode) 1884 iput(fat_inode); 1885 unload_nls(sbi->nls_io); 1886 unload_nls(sbi->nls_disk); 1887 fat_reset_iocharset(&sbi->options); 1888 sb->s_fs_info = NULL; 1889 kfree(sbi); 1890 return error; 1891 } 1892 1893 EXPORT_SYMBOL_GPL(fat_fill_super); 1894 1895 /* 1896 * helper function for fat_flush_inodes. This writes both the inode 1897 * and the file data blocks, waiting for in flight data blocks before 1898 * the start of the call. It does not wait for any io started 1899 * during the call 1900 */ 1901 static int writeback_inode(struct inode *inode) 1902 { 1903 1904 int ret; 1905 1906 /* if we used wait=1, sync_inode_metadata waits for the io for the 1907 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1908 * and filemap_fdatawrite is used for the data blocks 1909 */ 1910 ret = sync_inode_metadata(inode, 0); 1911 if (!ret) 1912 ret = filemap_fdatawrite(inode->i_mapping); 1913 return ret; 1914 } 1915 1916 /* 1917 * write data and metadata corresponding to i1 and i2. The io is 1918 * started but we do not wait for any of it to finish. 1919 * 1920 * filemap_flush is used for the block device, so if there is a dirty 1921 * page for a block already in flight, we will not wait and start the 1922 * io over again 1923 */ 1924 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1925 { 1926 int ret = 0; 1927 if (!MSDOS_SB(sb)->options.flush) 1928 return 0; 1929 if (i1) 1930 ret = writeback_inode(i1); 1931 if (!ret && i2) 1932 ret = writeback_inode(i2); 1933 if (!ret) { 1934 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1935 ret = filemap_flush(mapping); 1936 } 1937 return ret; 1938 } 1939 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1940 1941 static int __init init_fat_fs(void) 1942 { 1943 int err; 1944 1945 err = fat_cache_init(); 1946 if (err) 1947 return err; 1948 1949 err = fat_init_inodecache(); 1950 if (err) 1951 goto failed; 1952 1953 return 0; 1954 1955 failed: 1956 fat_cache_destroy(); 1957 return err; 1958 } 1959 1960 static void __exit exit_fat_fs(void) 1961 { 1962 fat_cache_destroy(); 1963 fat_destroy_inodecache(); 1964 } 1965 1966 module_init(init_fat_fs) 1967 module_exit(exit_fat_fs) 1968 1969 MODULE_LICENSE("GPL"); 1970