1 /* 2 * linux/fs/fat/inode.c 3 * 4 * Written 1992,1993 by Werner Almesberger 5 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner 6 * Rewritten for the constant inumbers support by Al Viro 7 * 8 * Fixes: 9 * 10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0 11 */ 12 13 #include <linux/module.h> 14 #include <linux/pagemap.h> 15 #include <linux/mpage.h> 16 #include <linux/vfs.h> 17 #include <linux/seq_file.h> 18 #include <linux/parser.h> 19 #include <linux/uio.h> 20 #include <linux/blkdev.h> 21 #include <linux/backing-dev.h> 22 #include <asm/unaligned.h> 23 #include <linux/iversion.h> 24 #include "fat.h" 25 26 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 27 /* if user don't select VFAT, this is undefined. */ 28 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 29 #endif 30 31 #define KB_IN_SECTORS 2 32 33 /* 34 * A deserialized copy of the on-disk structure laid out in struct 35 * fat_boot_sector. 36 */ 37 struct fat_bios_param_block { 38 u16 fat_sector_size; 39 u8 fat_sec_per_clus; 40 u16 fat_reserved; 41 u8 fat_fats; 42 u16 fat_dir_entries; 43 u16 fat_sectors; 44 u16 fat_fat_length; 45 u32 fat_total_sect; 46 47 u8 fat16_state; 48 u32 fat16_vol_id; 49 50 u32 fat32_length; 51 u32 fat32_root_cluster; 52 u16 fat32_info_sector; 53 u8 fat32_state; 54 u32 fat32_vol_id; 55 }; 56 57 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 58 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 59 60 static struct fat_floppy_defaults { 61 unsigned nr_sectors; 62 unsigned sec_per_clus; 63 unsigned dir_entries; 64 unsigned media; 65 unsigned fat_length; 66 } floppy_defaults[] = { 67 { 68 .nr_sectors = 160 * KB_IN_SECTORS, 69 .sec_per_clus = 1, 70 .dir_entries = 64, 71 .media = 0xFE, 72 .fat_length = 1, 73 }, 74 { 75 .nr_sectors = 180 * KB_IN_SECTORS, 76 .sec_per_clus = 1, 77 .dir_entries = 64, 78 .media = 0xFC, 79 .fat_length = 2, 80 }, 81 { 82 .nr_sectors = 320 * KB_IN_SECTORS, 83 .sec_per_clus = 2, 84 .dir_entries = 112, 85 .media = 0xFF, 86 .fat_length = 1, 87 }, 88 { 89 .nr_sectors = 360 * KB_IN_SECTORS, 90 .sec_per_clus = 2, 91 .dir_entries = 112, 92 .media = 0xFD, 93 .fat_length = 2, 94 }, 95 }; 96 97 int fat_add_cluster(struct inode *inode) 98 { 99 int err, cluster; 100 101 err = fat_alloc_clusters(inode, &cluster, 1); 102 if (err) 103 return err; 104 /* FIXME: this cluster should be added after data of this 105 * cluster is writed */ 106 err = fat_chain_add(inode, cluster, 1); 107 if (err) 108 fat_free_clusters(inode, cluster); 109 return err; 110 } 111 112 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 113 unsigned long *max_blocks, 114 struct buffer_head *bh_result, int create) 115 { 116 struct super_block *sb = inode->i_sb; 117 struct msdos_sb_info *sbi = MSDOS_SB(sb); 118 unsigned long mapped_blocks; 119 sector_t phys, last_block; 120 int err, offset; 121 122 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 123 if (err) 124 return err; 125 if (phys) { 126 map_bh(bh_result, sb, phys); 127 *max_blocks = min(mapped_blocks, *max_blocks); 128 return 0; 129 } 130 if (!create) 131 return 0; 132 133 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 134 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 135 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 136 return -EIO; 137 } 138 139 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); 140 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 141 /* 142 * allocate a cluster according to the following. 143 * 1) no more available blocks 144 * 2) not part of fallocate region 145 */ 146 if (!offset && !(iblock < last_block)) { 147 /* TODO: multiple cluster allocation would be desirable. */ 148 err = fat_add_cluster(inode); 149 if (err) 150 return err; 151 } 152 /* available blocks on this cluster */ 153 mapped_blocks = sbi->sec_per_clus - offset; 154 155 *max_blocks = min(mapped_blocks, *max_blocks); 156 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 157 158 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 159 if (err) 160 return err; 161 if (!phys) { 162 fat_fs_error(sb, 163 "invalid FAT chain (i_pos %lld, last_block %llu)", 164 MSDOS_I(inode)->i_pos, 165 (unsigned long long)last_block); 166 return -EIO; 167 } 168 169 BUG_ON(*max_blocks != mapped_blocks); 170 set_buffer_new(bh_result); 171 map_bh(bh_result, sb, phys); 172 173 return 0; 174 } 175 176 static int fat_get_block(struct inode *inode, sector_t iblock, 177 struct buffer_head *bh_result, int create) 178 { 179 struct super_block *sb = inode->i_sb; 180 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 181 int err; 182 183 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 184 if (err) 185 return err; 186 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 187 return 0; 188 } 189 190 static int fat_writepage(struct page *page, struct writeback_control *wbc) 191 { 192 return block_write_full_page(page, fat_get_block, wbc); 193 } 194 195 static int fat_writepages(struct address_space *mapping, 196 struct writeback_control *wbc) 197 { 198 return mpage_writepages(mapping, wbc, fat_get_block); 199 } 200 201 static int fat_readpage(struct file *file, struct page *page) 202 { 203 return mpage_readpage(page, fat_get_block); 204 } 205 206 static int fat_readpages(struct file *file, struct address_space *mapping, 207 struct list_head *pages, unsigned nr_pages) 208 { 209 return mpage_readpages(mapping, pages, nr_pages, fat_get_block); 210 } 211 212 static void fat_write_failed(struct address_space *mapping, loff_t to) 213 { 214 struct inode *inode = mapping->host; 215 216 if (to > inode->i_size) { 217 truncate_pagecache(inode, inode->i_size); 218 fat_truncate_blocks(inode, inode->i_size); 219 } 220 } 221 222 static int fat_write_begin(struct file *file, struct address_space *mapping, 223 loff_t pos, unsigned len, unsigned flags, 224 struct page **pagep, void **fsdata) 225 { 226 int err; 227 228 *pagep = NULL; 229 err = cont_write_begin(file, mapping, pos, len, flags, 230 pagep, fsdata, fat_get_block, 231 &MSDOS_I(mapping->host)->mmu_private); 232 if (err < 0) 233 fat_write_failed(mapping, pos + len); 234 return err; 235 } 236 237 static int fat_write_end(struct file *file, struct address_space *mapping, 238 loff_t pos, unsigned len, unsigned copied, 239 struct page *pagep, void *fsdata) 240 { 241 struct inode *inode = mapping->host; 242 int err; 243 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 244 if (err < len) 245 fat_write_failed(mapping, pos + len); 246 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 247 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 248 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 249 mark_inode_dirty(inode); 250 } 251 return err; 252 } 253 254 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 255 { 256 struct file *file = iocb->ki_filp; 257 struct address_space *mapping = file->f_mapping; 258 struct inode *inode = mapping->host; 259 size_t count = iov_iter_count(iter); 260 loff_t offset = iocb->ki_pos; 261 ssize_t ret; 262 263 if (iov_iter_rw(iter) == WRITE) { 264 /* 265 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 266 * so we need to update the ->mmu_private to block boundary. 267 * 268 * But we must fill the remaining area or hole by nul for 269 * updating ->mmu_private. 270 * 271 * Return 0, and fallback to normal buffered write. 272 */ 273 loff_t size = offset + count; 274 if (MSDOS_I(inode)->mmu_private < size) 275 return 0; 276 } 277 278 /* 279 * FAT need to use the DIO_LOCKING for avoiding the race 280 * condition of fat_get_block() and ->truncate(). 281 */ 282 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 283 if (ret < 0 && iov_iter_rw(iter) == WRITE) 284 fat_write_failed(mapping, offset + count); 285 286 return ret; 287 } 288 289 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 290 struct buffer_head *bh_result, int create) 291 { 292 struct super_block *sb = inode->i_sb; 293 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 294 int err; 295 sector_t bmap; 296 unsigned long mapped_blocks; 297 298 BUG_ON(create != 0); 299 300 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 301 if (err) 302 return err; 303 304 if (bmap) { 305 map_bh(bh_result, sb, bmap); 306 max_blocks = min(mapped_blocks, max_blocks); 307 } 308 309 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 310 311 return 0; 312 } 313 314 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 315 { 316 sector_t blocknr; 317 318 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 319 down_read(&MSDOS_I(mapping->host)->truncate_lock); 320 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 321 up_read(&MSDOS_I(mapping->host)->truncate_lock); 322 323 return blocknr; 324 } 325 326 /* 327 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 328 * up to the end of the block which corresponds to `from'. 329 * This is required during truncate to physically zeroout the tail end 330 * of that block so it doesn't yield old data if the file is later grown. 331 * Also, avoid causing failure from fsx for cases of "data past EOF" 332 */ 333 int fat_block_truncate_page(struct inode *inode, loff_t from) 334 { 335 return block_truncate_page(inode->i_mapping, from, fat_get_block); 336 } 337 338 static const struct address_space_operations fat_aops = { 339 .readpage = fat_readpage, 340 .readpages = fat_readpages, 341 .writepage = fat_writepage, 342 .writepages = fat_writepages, 343 .write_begin = fat_write_begin, 344 .write_end = fat_write_end, 345 .direct_IO = fat_direct_IO, 346 .bmap = _fat_bmap 347 }; 348 349 /* 350 * New FAT inode stuff. We do the following: 351 * a) i_ino is constant and has nothing with on-disk location. 352 * b) FAT manages its own cache of directory entries. 353 * c) *This* cache is indexed by on-disk location. 354 * d) inode has an associated directory entry, all right, but 355 * it may be unhashed. 356 * e) currently entries are stored within struct inode. That should 357 * change. 358 * f) we deal with races in the following way: 359 * 1. readdir() and lookup() do FAT-dir-cache lookup. 360 * 2. rename() unhashes the F-d-c entry and rehashes it in 361 * a new place. 362 * 3. unlink() and rmdir() unhash F-d-c entry. 363 * 4. fat_write_inode() checks whether the thing is unhashed. 364 * If it is we silently return. If it isn't we do bread(), 365 * check if the location is still valid and retry if it 366 * isn't. Otherwise we do changes. 367 * 5. Spinlock is used to protect hash/unhash/location check/lookup 368 * 6. fat_evict_inode() unhashes the F-d-c entry. 369 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 370 * and consider negative result as cache miss. 371 */ 372 373 static void fat_hash_init(struct super_block *sb) 374 { 375 struct msdos_sb_info *sbi = MSDOS_SB(sb); 376 int i; 377 378 spin_lock_init(&sbi->inode_hash_lock); 379 for (i = 0; i < FAT_HASH_SIZE; i++) 380 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 381 } 382 383 static inline unsigned long fat_hash(loff_t i_pos) 384 { 385 return hash_32(i_pos, FAT_HASH_BITS); 386 } 387 388 static void dir_hash_init(struct super_block *sb) 389 { 390 struct msdos_sb_info *sbi = MSDOS_SB(sb); 391 int i; 392 393 spin_lock_init(&sbi->dir_hash_lock); 394 for (i = 0; i < FAT_HASH_SIZE; i++) 395 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 396 } 397 398 void fat_attach(struct inode *inode, loff_t i_pos) 399 { 400 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 401 402 if (inode->i_ino != MSDOS_ROOT_INO) { 403 struct hlist_head *head = sbi->inode_hashtable 404 + fat_hash(i_pos); 405 406 spin_lock(&sbi->inode_hash_lock); 407 MSDOS_I(inode)->i_pos = i_pos; 408 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 409 spin_unlock(&sbi->inode_hash_lock); 410 } 411 412 /* If NFS support is enabled, cache the mapping of start cluster 413 * to directory inode. This is used during reconnection of 414 * dentries to the filesystem root. 415 */ 416 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 417 struct hlist_head *d_head = sbi->dir_hashtable; 418 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 419 420 spin_lock(&sbi->dir_hash_lock); 421 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 422 spin_unlock(&sbi->dir_hash_lock); 423 } 424 } 425 EXPORT_SYMBOL_GPL(fat_attach); 426 427 void fat_detach(struct inode *inode) 428 { 429 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 430 spin_lock(&sbi->inode_hash_lock); 431 MSDOS_I(inode)->i_pos = 0; 432 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 433 spin_unlock(&sbi->inode_hash_lock); 434 435 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 436 spin_lock(&sbi->dir_hash_lock); 437 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 438 spin_unlock(&sbi->dir_hash_lock); 439 } 440 } 441 EXPORT_SYMBOL_GPL(fat_detach); 442 443 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 444 { 445 struct msdos_sb_info *sbi = MSDOS_SB(sb); 446 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 447 struct msdos_inode_info *i; 448 struct inode *inode = NULL; 449 450 spin_lock(&sbi->inode_hash_lock); 451 hlist_for_each_entry(i, head, i_fat_hash) { 452 BUG_ON(i->vfs_inode.i_sb != sb); 453 if (i->i_pos != i_pos) 454 continue; 455 inode = igrab(&i->vfs_inode); 456 if (inode) 457 break; 458 } 459 spin_unlock(&sbi->inode_hash_lock); 460 return inode; 461 } 462 463 static int is_exec(unsigned char *extension) 464 { 465 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 466 467 for (walk = exe_extensions; *walk; walk += 3) 468 if (!strncmp(extension, walk, 3)) 469 return 1; 470 return 0; 471 } 472 473 static int fat_calc_dir_size(struct inode *inode) 474 { 475 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 476 int ret, fclus, dclus; 477 478 inode->i_size = 0; 479 if (MSDOS_I(inode)->i_start == 0) 480 return 0; 481 482 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 483 if (ret < 0) 484 return ret; 485 inode->i_size = (fclus + 1) << sbi->cluster_bits; 486 487 return 0; 488 } 489 490 static int fat_validate_dir(struct inode *dir) 491 { 492 struct super_block *sb = dir->i_sb; 493 494 if (dir->i_nlink < 2) { 495 /* Directory should have "."/".." entries at least. */ 496 fat_fs_error(sb, "corrupted directory (invalid entries)"); 497 return -EIO; 498 } 499 if (MSDOS_I(dir)->i_start == 0 || 500 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 501 /* Directory should point valid cluster. */ 502 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 503 return -EIO; 504 } 505 return 0; 506 } 507 508 /* doesn't deal with root inode */ 509 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 510 { 511 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 512 int error; 513 514 MSDOS_I(inode)->i_pos = 0; 515 inode->i_uid = sbi->options.fs_uid; 516 inode->i_gid = sbi->options.fs_gid; 517 inode_inc_iversion(inode); 518 inode->i_generation = get_seconds(); 519 520 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 521 inode->i_generation &= ~1; 522 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 523 inode->i_op = sbi->dir_ops; 524 inode->i_fop = &fat_dir_operations; 525 526 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 527 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 528 error = fat_calc_dir_size(inode); 529 if (error < 0) 530 return error; 531 MSDOS_I(inode)->mmu_private = inode->i_size; 532 533 set_nlink(inode, fat_subdirs(inode)); 534 535 error = fat_validate_dir(inode); 536 if (error < 0) 537 return error; 538 } else { /* not a directory */ 539 inode->i_generation |= 1; 540 inode->i_mode = fat_make_mode(sbi, de->attr, 541 ((sbi->options.showexec && !is_exec(de->name + 8)) 542 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 543 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 544 545 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 546 inode->i_size = le32_to_cpu(de->size); 547 inode->i_op = &fat_file_inode_operations; 548 inode->i_fop = &fat_file_operations; 549 inode->i_mapping->a_ops = &fat_aops; 550 MSDOS_I(inode)->mmu_private = inode->i_size; 551 } 552 if (de->attr & ATTR_SYS) { 553 if (sbi->options.sys_immutable) 554 inode->i_flags |= S_IMMUTABLE; 555 } 556 fat_save_attrs(inode, de->attr); 557 558 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 559 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 560 561 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 562 if (sbi->options.isvfat) { 563 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 564 de->cdate, de->ctime_cs); 565 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 566 } else 567 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME); 568 569 return 0; 570 } 571 572 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 573 { 574 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 575 mutex_lock(&sbi->nfs_build_inode_lock); 576 } 577 578 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 579 { 580 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 581 mutex_unlock(&sbi->nfs_build_inode_lock); 582 } 583 584 struct inode *fat_build_inode(struct super_block *sb, 585 struct msdos_dir_entry *de, loff_t i_pos) 586 { 587 struct inode *inode; 588 int err; 589 590 fat_lock_build_inode(MSDOS_SB(sb)); 591 inode = fat_iget(sb, i_pos); 592 if (inode) 593 goto out; 594 inode = new_inode(sb); 595 if (!inode) { 596 inode = ERR_PTR(-ENOMEM); 597 goto out; 598 } 599 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 600 inode_set_iversion(inode, 1); 601 err = fat_fill_inode(inode, de); 602 if (err) { 603 iput(inode); 604 inode = ERR_PTR(err); 605 goto out; 606 } 607 fat_attach(inode, i_pos); 608 insert_inode_hash(inode); 609 out: 610 fat_unlock_build_inode(MSDOS_SB(sb)); 611 return inode; 612 } 613 614 EXPORT_SYMBOL_GPL(fat_build_inode); 615 616 static int __fat_write_inode(struct inode *inode, int wait); 617 618 static void fat_free_eofblocks(struct inode *inode) 619 { 620 /* Release unwritten fallocated blocks on inode eviction. */ 621 if ((inode->i_blocks << 9) > 622 round_up(MSDOS_I(inode)->mmu_private, 623 MSDOS_SB(inode->i_sb)->cluster_size)) { 624 int err; 625 626 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 627 /* Fallocate results in updating the i_start/iogstart 628 * for the zero byte file. So, make it return to 629 * original state during evict and commit it to avoid 630 * any corruption on the next access to the cluster 631 * chain for the file. 632 */ 633 err = __fat_write_inode(inode, inode_needs_sync(inode)); 634 if (err) { 635 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 636 "update on disk inode for unused " 637 "fallocated blocks, inode could be " 638 "corrupted. Please run fsck"); 639 } 640 641 } 642 } 643 644 static void fat_evict_inode(struct inode *inode) 645 { 646 truncate_inode_pages_final(&inode->i_data); 647 if (!inode->i_nlink) { 648 inode->i_size = 0; 649 fat_truncate_blocks(inode, 0); 650 } else 651 fat_free_eofblocks(inode); 652 653 invalidate_inode_buffers(inode); 654 clear_inode(inode); 655 fat_cache_inval_inode(inode); 656 fat_detach(inode); 657 } 658 659 static void fat_set_state(struct super_block *sb, 660 unsigned int set, unsigned int force) 661 { 662 struct buffer_head *bh; 663 struct fat_boot_sector *b; 664 struct msdos_sb_info *sbi = MSDOS_SB(sb); 665 666 /* do not change any thing if mounted read only */ 667 if (sb_rdonly(sb) && !force) 668 return; 669 670 /* do not change state if fs was dirty */ 671 if (sbi->dirty) { 672 /* warn only on set (mount). */ 673 if (set) 674 fat_msg(sb, KERN_WARNING, "Volume was not properly " 675 "unmounted. Some data may be corrupt. " 676 "Please run fsck."); 677 return; 678 } 679 680 bh = sb_bread(sb, 0); 681 if (bh == NULL) { 682 fat_msg(sb, KERN_ERR, "unable to read boot sector " 683 "to mark fs as dirty"); 684 return; 685 } 686 687 b = (struct fat_boot_sector *) bh->b_data; 688 689 if (is_fat32(sbi)) { 690 if (set) 691 b->fat32.state |= FAT_STATE_DIRTY; 692 else 693 b->fat32.state &= ~FAT_STATE_DIRTY; 694 } else /* fat 16 and 12 */ { 695 if (set) 696 b->fat16.state |= FAT_STATE_DIRTY; 697 else 698 b->fat16.state &= ~FAT_STATE_DIRTY; 699 } 700 701 mark_buffer_dirty(bh); 702 sync_dirty_buffer(bh); 703 brelse(bh); 704 } 705 706 static void fat_reset_iocharset(struct fat_mount_options *opts) 707 { 708 if (opts->iocharset != fat_default_iocharset) { 709 /* Note: opts->iocharset can be NULL here */ 710 kfree(opts->iocharset); 711 opts->iocharset = fat_default_iocharset; 712 } 713 } 714 715 static void delayed_free(struct rcu_head *p) 716 { 717 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 718 unload_nls(sbi->nls_disk); 719 unload_nls(sbi->nls_io); 720 fat_reset_iocharset(&sbi->options); 721 kfree(sbi); 722 } 723 724 static void fat_put_super(struct super_block *sb) 725 { 726 struct msdos_sb_info *sbi = MSDOS_SB(sb); 727 728 fat_set_state(sb, 0, 0); 729 730 iput(sbi->fsinfo_inode); 731 iput(sbi->fat_inode); 732 733 call_rcu(&sbi->rcu, delayed_free); 734 } 735 736 static struct kmem_cache *fat_inode_cachep; 737 738 static struct inode *fat_alloc_inode(struct super_block *sb) 739 { 740 struct msdos_inode_info *ei; 741 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 742 if (!ei) 743 return NULL; 744 745 init_rwsem(&ei->truncate_lock); 746 return &ei->vfs_inode; 747 } 748 749 static void fat_i_callback(struct rcu_head *head) 750 { 751 struct inode *inode = container_of(head, struct inode, i_rcu); 752 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 753 } 754 755 static void fat_destroy_inode(struct inode *inode) 756 { 757 call_rcu(&inode->i_rcu, fat_i_callback); 758 } 759 760 static void init_once(void *foo) 761 { 762 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 763 764 spin_lock_init(&ei->cache_lru_lock); 765 ei->nr_caches = 0; 766 ei->cache_valid_id = FAT_CACHE_VALID + 1; 767 INIT_LIST_HEAD(&ei->cache_lru); 768 INIT_HLIST_NODE(&ei->i_fat_hash); 769 INIT_HLIST_NODE(&ei->i_dir_hash); 770 inode_init_once(&ei->vfs_inode); 771 } 772 773 static int __init fat_init_inodecache(void) 774 { 775 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 776 sizeof(struct msdos_inode_info), 777 0, (SLAB_RECLAIM_ACCOUNT| 778 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 779 init_once); 780 if (fat_inode_cachep == NULL) 781 return -ENOMEM; 782 return 0; 783 } 784 785 static void __exit fat_destroy_inodecache(void) 786 { 787 /* 788 * Make sure all delayed rcu free inodes are flushed before we 789 * destroy cache. 790 */ 791 rcu_barrier(); 792 kmem_cache_destroy(fat_inode_cachep); 793 } 794 795 static int fat_remount(struct super_block *sb, int *flags, char *data) 796 { 797 bool new_rdonly; 798 struct msdos_sb_info *sbi = MSDOS_SB(sb); 799 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 800 801 sync_filesystem(sb); 802 803 /* make sure we update state on remount. */ 804 new_rdonly = *flags & SB_RDONLY; 805 if (new_rdonly != sb_rdonly(sb)) { 806 if (new_rdonly) 807 fat_set_state(sb, 0, 0); 808 else 809 fat_set_state(sb, 1, 1); 810 } 811 return 0; 812 } 813 814 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 815 { 816 struct super_block *sb = dentry->d_sb; 817 struct msdos_sb_info *sbi = MSDOS_SB(sb); 818 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 819 820 /* If the count of free cluster is still unknown, counts it here. */ 821 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 822 int err = fat_count_free_clusters(dentry->d_sb); 823 if (err) 824 return err; 825 } 826 827 buf->f_type = dentry->d_sb->s_magic; 828 buf->f_bsize = sbi->cluster_size; 829 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 830 buf->f_bfree = sbi->free_clusters; 831 buf->f_bavail = sbi->free_clusters; 832 buf->f_fsid.val[0] = (u32)id; 833 buf->f_fsid.val[1] = (u32)(id >> 32); 834 buf->f_namelen = 835 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 836 837 return 0; 838 } 839 840 static int __fat_write_inode(struct inode *inode, int wait) 841 { 842 struct super_block *sb = inode->i_sb; 843 struct msdos_sb_info *sbi = MSDOS_SB(sb); 844 struct buffer_head *bh; 845 struct msdos_dir_entry *raw_entry; 846 loff_t i_pos; 847 sector_t blocknr; 848 int err, offset; 849 850 if (inode->i_ino == MSDOS_ROOT_INO) 851 return 0; 852 853 retry: 854 i_pos = fat_i_pos_read(sbi, inode); 855 if (!i_pos) 856 return 0; 857 858 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 859 bh = sb_bread(sb, blocknr); 860 if (!bh) { 861 fat_msg(sb, KERN_ERR, "unable to read inode block " 862 "for updating (i_pos %lld)", i_pos); 863 return -EIO; 864 } 865 spin_lock(&sbi->inode_hash_lock); 866 if (i_pos != MSDOS_I(inode)->i_pos) { 867 spin_unlock(&sbi->inode_hash_lock); 868 brelse(bh); 869 goto retry; 870 } 871 872 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 873 if (S_ISDIR(inode->i_mode)) 874 raw_entry->size = 0; 875 else 876 raw_entry->size = cpu_to_le32(inode->i_size); 877 raw_entry->attr = fat_make_attrs(inode); 878 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 879 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 880 &raw_entry->date, NULL); 881 if (sbi->options.isvfat) { 882 __le16 atime; 883 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 884 &raw_entry->cdate, &raw_entry->ctime_cs); 885 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 886 &raw_entry->adate, NULL); 887 } 888 spin_unlock(&sbi->inode_hash_lock); 889 mark_buffer_dirty(bh); 890 err = 0; 891 if (wait) 892 err = sync_dirty_buffer(bh); 893 brelse(bh); 894 return err; 895 } 896 897 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 898 { 899 int err; 900 901 if (inode->i_ino == MSDOS_FSINFO_INO) { 902 struct super_block *sb = inode->i_sb; 903 904 mutex_lock(&MSDOS_SB(sb)->s_lock); 905 err = fat_clusters_flush(sb); 906 mutex_unlock(&MSDOS_SB(sb)->s_lock); 907 } else 908 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 909 910 return err; 911 } 912 913 int fat_sync_inode(struct inode *inode) 914 { 915 return __fat_write_inode(inode, 1); 916 } 917 918 EXPORT_SYMBOL_GPL(fat_sync_inode); 919 920 static int fat_show_options(struct seq_file *m, struct dentry *root); 921 static const struct super_operations fat_sops = { 922 .alloc_inode = fat_alloc_inode, 923 .destroy_inode = fat_destroy_inode, 924 .write_inode = fat_write_inode, 925 .evict_inode = fat_evict_inode, 926 .put_super = fat_put_super, 927 .statfs = fat_statfs, 928 .remount_fs = fat_remount, 929 930 .show_options = fat_show_options, 931 }; 932 933 static int fat_show_options(struct seq_file *m, struct dentry *root) 934 { 935 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 936 struct fat_mount_options *opts = &sbi->options; 937 int isvfat = opts->isvfat; 938 939 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 940 seq_printf(m, ",uid=%u", 941 from_kuid_munged(&init_user_ns, opts->fs_uid)); 942 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 943 seq_printf(m, ",gid=%u", 944 from_kgid_munged(&init_user_ns, opts->fs_gid)); 945 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 946 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 947 if (opts->allow_utime) 948 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 949 if (sbi->nls_disk) 950 /* strip "cp" prefix from displayed option */ 951 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 952 if (isvfat) { 953 if (sbi->nls_io) 954 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 955 956 switch (opts->shortname) { 957 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 958 seq_puts(m, ",shortname=win95"); 959 break; 960 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 961 seq_puts(m, ",shortname=winnt"); 962 break; 963 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 964 seq_puts(m, ",shortname=mixed"); 965 break; 966 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 967 seq_puts(m, ",shortname=lower"); 968 break; 969 default: 970 seq_puts(m, ",shortname=unknown"); 971 break; 972 } 973 } 974 if (opts->name_check != 'n') 975 seq_printf(m, ",check=%c", opts->name_check); 976 if (opts->usefree) 977 seq_puts(m, ",usefree"); 978 if (opts->quiet) 979 seq_puts(m, ",quiet"); 980 if (opts->showexec) 981 seq_puts(m, ",showexec"); 982 if (opts->sys_immutable) 983 seq_puts(m, ",sys_immutable"); 984 if (!isvfat) { 985 if (opts->dotsOK) 986 seq_puts(m, ",dotsOK=yes"); 987 if (opts->nocase) 988 seq_puts(m, ",nocase"); 989 } else { 990 if (opts->utf8) 991 seq_puts(m, ",utf8"); 992 if (opts->unicode_xlate) 993 seq_puts(m, ",uni_xlate"); 994 if (!opts->numtail) 995 seq_puts(m, ",nonumtail"); 996 if (opts->rodir) 997 seq_puts(m, ",rodir"); 998 } 999 if (opts->flush) 1000 seq_puts(m, ",flush"); 1001 if (opts->tz_set) { 1002 if (opts->time_offset) 1003 seq_printf(m, ",time_offset=%d", opts->time_offset); 1004 else 1005 seq_puts(m, ",tz=UTC"); 1006 } 1007 if (opts->errors == FAT_ERRORS_CONT) 1008 seq_puts(m, ",errors=continue"); 1009 else if (opts->errors == FAT_ERRORS_PANIC) 1010 seq_puts(m, ",errors=panic"); 1011 else 1012 seq_puts(m, ",errors=remount-ro"); 1013 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1014 seq_puts(m, ",nfs=nostale_ro"); 1015 else if (opts->nfs) 1016 seq_puts(m, ",nfs=stale_rw"); 1017 if (opts->discard) 1018 seq_puts(m, ",discard"); 1019 if (opts->dos1xfloppy) 1020 seq_puts(m, ",dos1xfloppy"); 1021 1022 return 0; 1023 } 1024 1025 enum { 1026 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1027 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1028 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1029 Opt_immutable, Opt_dots, Opt_nodots, 1030 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1031 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1032 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1033 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1034 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1035 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1036 }; 1037 1038 static const match_table_t fat_tokens = { 1039 {Opt_check_r, "check=relaxed"}, 1040 {Opt_check_s, "check=strict"}, 1041 {Opt_check_n, "check=normal"}, 1042 {Opt_check_r, "check=r"}, 1043 {Opt_check_s, "check=s"}, 1044 {Opt_check_n, "check=n"}, 1045 {Opt_uid, "uid=%u"}, 1046 {Opt_gid, "gid=%u"}, 1047 {Opt_umask, "umask=%o"}, 1048 {Opt_dmask, "dmask=%o"}, 1049 {Opt_fmask, "fmask=%o"}, 1050 {Opt_allow_utime, "allow_utime=%o"}, 1051 {Opt_codepage, "codepage=%u"}, 1052 {Opt_usefree, "usefree"}, 1053 {Opt_nocase, "nocase"}, 1054 {Opt_quiet, "quiet"}, 1055 {Opt_showexec, "showexec"}, 1056 {Opt_debug, "debug"}, 1057 {Opt_immutable, "sys_immutable"}, 1058 {Opt_flush, "flush"}, 1059 {Opt_tz_utc, "tz=UTC"}, 1060 {Opt_time_offset, "time_offset=%d"}, 1061 {Opt_err_cont, "errors=continue"}, 1062 {Opt_err_panic, "errors=panic"}, 1063 {Opt_err_ro, "errors=remount-ro"}, 1064 {Opt_discard, "discard"}, 1065 {Opt_nfs_stale_rw, "nfs"}, 1066 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1067 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1068 {Opt_dos1xfloppy, "dos1xfloppy"}, 1069 {Opt_obsolete, "conv=binary"}, 1070 {Opt_obsolete, "conv=text"}, 1071 {Opt_obsolete, "conv=auto"}, 1072 {Opt_obsolete, "conv=b"}, 1073 {Opt_obsolete, "conv=t"}, 1074 {Opt_obsolete, "conv=a"}, 1075 {Opt_obsolete, "fat=%u"}, 1076 {Opt_obsolete, "blocksize=%u"}, 1077 {Opt_obsolete, "cvf_format=%20s"}, 1078 {Opt_obsolete, "cvf_options=%100s"}, 1079 {Opt_obsolete, "posix"}, 1080 {Opt_err, NULL}, 1081 }; 1082 static const match_table_t msdos_tokens = { 1083 {Opt_nodots, "nodots"}, 1084 {Opt_nodots, "dotsOK=no"}, 1085 {Opt_dots, "dots"}, 1086 {Opt_dots, "dotsOK=yes"}, 1087 {Opt_err, NULL} 1088 }; 1089 static const match_table_t vfat_tokens = { 1090 {Opt_charset, "iocharset=%s"}, 1091 {Opt_shortname_lower, "shortname=lower"}, 1092 {Opt_shortname_win95, "shortname=win95"}, 1093 {Opt_shortname_winnt, "shortname=winnt"}, 1094 {Opt_shortname_mixed, "shortname=mixed"}, 1095 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1096 {Opt_utf8_no, "utf8=no"}, 1097 {Opt_utf8_no, "utf8=false"}, 1098 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1099 {Opt_utf8_yes, "utf8=yes"}, 1100 {Opt_utf8_yes, "utf8=true"}, 1101 {Opt_utf8_yes, "utf8"}, 1102 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1103 {Opt_uni_xl_no, "uni_xlate=no"}, 1104 {Opt_uni_xl_no, "uni_xlate=false"}, 1105 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1106 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1107 {Opt_uni_xl_yes, "uni_xlate=true"}, 1108 {Opt_uni_xl_yes, "uni_xlate"}, 1109 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1110 {Opt_nonumtail_no, "nonumtail=no"}, 1111 {Opt_nonumtail_no, "nonumtail=false"}, 1112 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1113 {Opt_nonumtail_yes, "nonumtail=yes"}, 1114 {Opt_nonumtail_yes, "nonumtail=true"}, 1115 {Opt_nonumtail_yes, "nonumtail"}, 1116 {Opt_rodir, "rodir"}, 1117 {Opt_err, NULL} 1118 }; 1119 1120 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1121 int silent, int *debug, struct fat_mount_options *opts) 1122 { 1123 char *p; 1124 substring_t args[MAX_OPT_ARGS]; 1125 int option; 1126 char *iocharset; 1127 1128 opts->isvfat = is_vfat; 1129 1130 opts->fs_uid = current_uid(); 1131 opts->fs_gid = current_gid(); 1132 opts->fs_fmask = opts->fs_dmask = current_umask(); 1133 opts->allow_utime = -1; 1134 opts->codepage = fat_default_codepage; 1135 fat_reset_iocharset(opts); 1136 if (is_vfat) { 1137 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1138 opts->rodir = 0; 1139 } else { 1140 opts->shortname = 0; 1141 opts->rodir = 1; 1142 } 1143 opts->name_check = 'n'; 1144 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1145 opts->unicode_xlate = 0; 1146 opts->numtail = 1; 1147 opts->usefree = opts->nocase = 0; 1148 opts->tz_set = 0; 1149 opts->nfs = 0; 1150 opts->errors = FAT_ERRORS_RO; 1151 *debug = 0; 1152 1153 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1154 1155 if (!options) 1156 goto out; 1157 1158 while ((p = strsep(&options, ",")) != NULL) { 1159 int token; 1160 if (!*p) 1161 continue; 1162 1163 token = match_token(p, fat_tokens, args); 1164 if (token == Opt_err) { 1165 if (is_vfat) 1166 token = match_token(p, vfat_tokens, args); 1167 else 1168 token = match_token(p, msdos_tokens, args); 1169 } 1170 switch (token) { 1171 case Opt_check_s: 1172 opts->name_check = 's'; 1173 break; 1174 case Opt_check_r: 1175 opts->name_check = 'r'; 1176 break; 1177 case Opt_check_n: 1178 opts->name_check = 'n'; 1179 break; 1180 case Opt_usefree: 1181 opts->usefree = 1; 1182 break; 1183 case Opt_nocase: 1184 if (!is_vfat) 1185 opts->nocase = 1; 1186 else { 1187 /* for backward compatibility */ 1188 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1189 | VFAT_SFN_CREATE_WIN95; 1190 } 1191 break; 1192 case Opt_quiet: 1193 opts->quiet = 1; 1194 break; 1195 case Opt_showexec: 1196 opts->showexec = 1; 1197 break; 1198 case Opt_debug: 1199 *debug = 1; 1200 break; 1201 case Opt_immutable: 1202 opts->sys_immutable = 1; 1203 break; 1204 case Opt_uid: 1205 if (match_int(&args[0], &option)) 1206 return -EINVAL; 1207 opts->fs_uid = make_kuid(current_user_ns(), option); 1208 if (!uid_valid(opts->fs_uid)) 1209 return -EINVAL; 1210 break; 1211 case Opt_gid: 1212 if (match_int(&args[0], &option)) 1213 return -EINVAL; 1214 opts->fs_gid = make_kgid(current_user_ns(), option); 1215 if (!gid_valid(opts->fs_gid)) 1216 return -EINVAL; 1217 break; 1218 case Opt_umask: 1219 if (match_octal(&args[0], &option)) 1220 return -EINVAL; 1221 opts->fs_fmask = opts->fs_dmask = option; 1222 break; 1223 case Opt_dmask: 1224 if (match_octal(&args[0], &option)) 1225 return -EINVAL; 1226 opts->fs_dmask = option; 1227 break; 1228 case Opt_fmask: 1229 if (match_octal(&args[0], &option)) 1230 return -EINVAL; 1231 opts->fs_fmask = option; 1232 break; 1233 case Opt_allow_utime: 1234 if (match_octal(&args[0], &option)) 1235 return -EINVAL; 1236 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1237 break; 1238 case Opt_codepage: 1239 if (match_int(&args[0], &option)) 1240 return -EINVAL; 1241 opts->codepage = option; 1242 break; 1243 case Opt_flush: 1244 opts->flush = 1; 1245 break; 1246 case Opt_time_offset: 1247 if (match_int(&args[0], &option)) 1248 return -EINVAL; 1249 /* 1250 * GMT+-12 zones may have DST corrections so at least 1251 * 13 hours difference is needed. Make the limit 24 1252 * just in case someone invents something unusual. 1253 */ 1254 if (option < -24 * 60 || option > 24 * 60) 1255 return -EINVAL; 1256 opts->tz_set = 1; 1257 opts->time_offset = option; 1258 break; 1259 case Opt_tz_utc: 1260 opts->tz_set = 1; 1261 opts->time_offset = 0; 1262 break; 1263 case Opt_err_cont: 1264 opts->errors = FAT_ERRORS_CONT; 1265 break; 1266 case Opt_err_panic: 1267 opts->errors = FAT_ERRORS_PANIC; 1268 break; 1269 case Opt_err_ro: 1270 opts->errors = FAT_ERRORS_RO; 1271 break; 1272 case Opt_nfs_stale_rw: 1273 opts->nfs = FAT_NFS_STALE_RW; 1274 break; 1275 case Opt_nfs_nostale_ro: 1276 opts->nfs = FAT_NFS_NOSTALE_RO; 1277 break; 1278 case Opt_dos1xfloppy: 1279 opts->dos1xfloppy = 1; 1280 break; 1281 1282 /* msdos specific */ 1283 case Opt_dots: 1284 opts->dotsOK = 1; 1285 break; 1286 case Opt_nodots: 1287 opts->dotsOK = 0; 1288 break; 1289 1290 /* vfat specific */ 1291 case Opt_charset: 1292 fat_reset_iocharset(opts); 1293 iocharset = match_strdup(&args[0]); 1294 if (!iocharset) 1295 return -ENOMEM; 1296 opts->iocharset = iocharset; 1297 break; 1298 case Opt_shortname_lower: 1299 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1300 | VFAT_SFN_CREATE_WIN95; 1301 break; 1302 case Opt_shortname_win95: 1303 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1304 | VFAT_SFN_CREATE_WIN95; 1305 break; 1306 case Opt_shortname_winnt: 1307 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1308 | VFAT_SFN_CREATE_WINNT; 1309 break; 1310 case Opt_shortname_mixed: 1311 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1312 | VFAT_SFN_CREATE_WIN95; 1313 break; 1314 case Opt_utf8_no: /* 0 or no or false */ 1315 opts->utf8 = 0; 1316 break; 1317 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1318 opts->utf8 = 1; 1319 break; 1320 case Opt_uni_xl_no: /* 0 or no or false */ 1321 opts->unicode_xlate = 0; 1322 break; 1323 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1324 opts->unicode_xlate = 1; 1325 break; 1326 case Opt_nonumtail_no: /* 0 or no or false */ 1327 opts->numtail = 1; /* negated option */ 1328 break; 1329 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1330 opts->numtail = 0; /* negated option */ 1331 break; 1332 case Opt_rodir: 1333 opts->rodir = 1; 1334 break; 1335 case Opt_discard: 1336 opts->discard = 1; 1337 break; 1338 1339 /* obsolete mount options */ 1340 case Opt_obsolete: 1341 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1342 "not supported now", p); 1343 break; 1344 /* unknown option */ 1345 default: 1346 if (!silent) { 1347 fat_msg(sb, KERN_ERR, 1348 "Unrecognized mount option \"%s\" " 1349 "or missing value", p); 1350 } 1351 return -EINVAL; 1352 } 1353 } 1354 1355 out: 1356 /* UTF-8 doesn't provide FAT semantics */ 1357 if (!strcmp(opts->iocharset, "utf8")) { 1358 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1359 " for FAT filesystems, filesystem will be " 1360 "case sensitive!"); 1361 } 1362 1363 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1364 if (opts->allow_utime == (unsigned short)-1) 1365 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1366 if (opts->unicode_xlate) 1367 opts->utf8 = 0; 1368 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1369 sb->s_flags |= SB_RDONLY; 1370 sb->s_export_op = &fat_export_ops_nostale; 1371 } 1372 1373 return 0; 1374 } 1375 1376 static void fat_dummy_inode_init(struct inode *inode) 1377 { 1378 /* Initialize this dummy inode to work as no-op. */ 1379 MSDOS_I(inode)->mmu_private = 0; 1380 MSDOS_I(inode)->i_start = 0; 1381 MSDOS_I(inode)->i_logstart = 0; 1382 MSDOS_I(inode)->i_attrs = 0; 1383 MSDOS_I(inode)->i_pos = 0; 1384 } 1385 1386 static int fat_read_root(struct inode *inode) 1387 { 1388 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1389 int error; 1390 1391 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1392 inode->i_uid = sbi->options.fs_uid; 1393 inode->i_gid = sbi->options.fs_gid; 1394 inode_inc_iversion(inode); 1395 inode->i_generation = 0; 1396 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1397 inode->i_op = sbi->dir_ops; 1398 inode->i_fop = &fat_dir_operations; 1399 if (is_fat32(sbi)) { 1400 MSDOS_I(inode)->i_start = sbi->root_cluster; 1401 error = fat_calc_dir_size(inode); 1402 if (error < 0) 1403 return error; 1404 } else { 1405 MSDOS_I(inode)->i_start = 0; 1406 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1407 } 1408 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1409 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1410 MSDOS_I(inode)->i_logstart = 0; 1411 MSDOS_I(inode)->mmu_private = inode->i_size; 1412 1413 fat_save_attrs(inode, ATTR_DIR); 1414 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1415 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1416 set_nlink(inode, fat_subdirs(inode)+2); 1417 1418 return 0; 1419 } 1420 1421 static unsigned long calc_fat_clusters(struct super_block *sb) 1422 { 1423 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1424 1425 /* Divide first to avoid overflow */ 1426 if (!is_fat12(sbi)) { 1427 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1428 return ent_per_sec * sbi->fat_length; 1429 } 1430 1431 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1432 } 1433 1434 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1435 { 1436 if (get_unaligned_le16(&b->sector_size)) 1437 return false; 1438 if (b->sec_per_clus) 1439 return false; 1440 if (b->reserved) 1441 return false; 1442 if (b->fats) 1443 return false; 1444 if (get_unaligned_le16(&b->dir_entries)) 1445 return false; 1446 if (get_unaligned_le16(&b->sectors)) 1447 return false; 1448 if (b->media) 1449 return false; 1450 if (b->fat_length) 1451 return false; 1452 if (b->secs_track) 1453 return false; 1454 if (b->heads) 1455 return false; 1456 return true; 1457 } 1458 1459 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1460 int silent, struct fat_bios_param_block *bpb) 1461 { 1462 int error = -EINVAL; 1463 1464 /* Read in BPB ... */ 1465 memset(bpb, 0, sizeof(*bpb)); 1466 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1467 bpb->fat_sec_per_clus = b->sec_per_clus; 1468 bpb->fat_reserved = le16_to_cpu(b->reserved); 1469 bpb->fat_fats = b->fats; 1470 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1471 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1472 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1473 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1474 1475 bpb->fat16_state = b->fat16.state; 1476 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1477 1478 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1479 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1480 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1481 bpb->fat32_state = b->fat32.state; 1482 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1483 1484 /* Validate this looks like a FAT filesystem BPB */ 1485 if (!bpb->fat_reserved) { 1486 if (!silent) 1487 fat_msg(sb, KERN_ERR, 1488 "bogus number of reserved sectors"); 1489 goto out; 1490 } 1491 if (!bpb->fat_fats) { 1492 if (!silent) 1493 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1494 goto out; 1495 } 1496 1497 /* 1498 * Earlier we checked here that b->secs_track and b->head are nonzero, 1499 * but it turns out valid FAT filesystems can have zero there. 1500 */ 1501 1502 if (!fat_valid_media(b->media)) { 1503 if (!silent) 1504 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1505 (unsigned)b->media); 1506 goto out; 1507 } 1508 1509 if (!is_power_of_2(bpb->fat_sector_size) 1510 || (bpb->fat_sector_size < 512) 1511 || (bpb->fat_sector_size > 4096)) { 1512 if (!silent) 1513 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1514 (unsigned)bpb->fat_sector_size); 1515 goto out; 1516 } 1517 1518 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1519 if (!silent) 1520 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1521 (unsigned)bpb->fat_sec_per_clus); 1522 goto out; 1523 } 1524 1525 error = 0; 1526 1527 out: 1528 return error; 1529 } 1530 1531 static int fat_read_static_bpb(struct super_block *sb, 1532 struct fat_boot_sector *b, int silent, 1533 struct fat_bios_param_block *bpb) 1534 { 1535 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1536 1537 struct fat_floppy_defaults *fdefaults = NULL; 1538 int error = -EINVAL; 1539 sector_t bd_sects; 1540 unsigned i; 1541 1542 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1543 1544 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1545 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1546 if (!silent) 1547 fat_msg(sb, KERN_ERR, 1548 "%s; no bootstrapping code", notdos1x); 1549 goto out; 1550 } 1551 1552 /* 1553 * If any value in this region is non-zero, it isn't archaic 1554 * DOS. 1555 */ 1556 if (!fat_bpb_is_zero(b)) { 1557 if (!silent) 1558 fat_msg(sb, KERN_ERR, 1559 "%s; DOS 2.x BPB is non-zero", notdos1x); 1560 goto out; 1561 } 1562 1563 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1564 if (floppy_defaults[i].nr_sectors == bd_sects) { 1565 fdefaults = &floppy_defaults[i]; 1566 break; 1567 } 1568 } 1569 1570 if (fdefaults == NULL) { 1571 if (!silent) 1572 fat_msg(sb, KERN_WARNING, 1573 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1574 (u64)bd_sects); 1575 goto out; 1576 } 1577 1578 if (!silent) 1579 fat_msg(sb, KERN_INFO, 1580 "This looks like a DOS 1.x volume; assuming default BPB values"); 1581 1582 memset(bpb, 0, sizeof(*bpb)); 1583 bpb->fat_sector_size = SECTOR_SIZE; 1584 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1585 bpb->fat_reserved = 1; 1586 bpb->fat_fats = 2; 1587 bpb->fat_dir_entries = fdefaults->dir_entries; 1588 bpb->fat_sectors = fdefaults->nr_sectors; 1589 bpb->fat_fat_length = fdefaults->fat_length; 1590 1591 error = 0; 1592 1593 out: 1594 return error; 1595 } 1596 1597 /* 1598 * Read the super block of an MS-DOS FS. 1599 */ 1600 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1601 void (*setup)(struct super_block *)) 1602 { 1603 struct inode *root_inode = NULL, *fat_inode = NULL; 1604 struct inode *fsinfo_inode = NULL; 1605 struct buffer_head *bh; 1606 struct fat_bios_param_block bpb; 1607 struct msdos_sb_info *sbi; 1608 u16 logical_sector_size; 1609 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1610 int debug; 1611 long error; 1612 char buf[50]; 1613 1614 /* 1615 * GFP_KERNEL is ok here, because while we do hold the 1616 * superblock lock, memory pressure can't call back into 1617 * the filesystem, since we're only just about to mount 1618 * it and have no inodes etc active! 1619 */ 1620 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1621 if (!sbi) 1622 return -ENOMEM; 1623 sb->s_fs_info = sbi; 1624 1625 sb->s_flags |= SB_NODIRATIME; 1626 sb->s_magic = MSDOS_SUPER_MAGIC; 1627 sb->s_op = &fat_sops; 1628 sb->s_export_op = &fat_export_ops; 1629 /* 1630 * fat timestamps are complex and truncated by fat itself, so 1631 * we set 1 here to be fast 1632 */ 1633 sb->s_time_gran = 1; 1634 mutex_init(&sbi->nfs_build_inode_lock); 1635 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1636 DEFAULT_RATELIMIT_BURST); 1637 1638 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1639 if (error) 1640 goto out_fail; 1641 1642 setup(sb); /* flavour-specific stuff that needs options */ 1643 1644 error = -EIO; 1645 sb_min_blocksize(sb, 512); 1646 bh = sb_bread(sb, 0); 1647 if (bh == NULL) { 1648 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1649 goto out_fail; 1650 } 1651 1652 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1653 &bpb); 1654 if (error == -EINVAL && sbi->options.dos1xfloppy) 1655 error = fat_read_static_bpb(sb, 1656 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1657 brelse(bh); 1658 1659 if (error == -EINVAL) 1660 goto out_invalid; 1661 else if (error) 1662 goto out_fail; 1663 1664 logical_sector_size = bpb.fat_sector_size; 1665 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1666 1667 error = -EIO; 1668 if (logical_sector_size < sb->s_blocksize) { 1669 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1670 " (logical sector size = %u)", logical_sector_size); 1671 goto out_fail; 1672 } 1673 1674 if (logical_sector_size > sb->s_blocksize) { 1675 struct buffer_head *bh_resize; 1676 1677 if (!sb_set_blocksize(sb, logical_sector_size)) { 1678 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1679 logical_sector_size); 1680 goto out_fail; 1681 } 1682 1683 /* Verify that the larger boot sector is fully readable */ 1684 bh_resize = sb_bread(sb, 0); 1685 if (bh_resize == NULL) { 1686 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1687 " (logical sector size = %lu)", 1688 sb->s_blocksize); 1689 goto out_fail; 1690 } 1691 brelse(bh_resize); 1692 } 1693 1694 mutex_init(&sbi->s_lock); 1695 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1696 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1697 sbi->fats = bpb.fat_fats; 1698 sbi->fat_bits = 0; /* Don't know yet */ 1699 sbi->fat_start = bpb.fat_reserved; 1700 sbi->fat_length = bpb.fat_fat_length; 1701 sbi->root_cluster = 0; 1702 sbi->free_clusters = -1; /* Don't know yet */ 1703 sbi->free_clus_valid = 0; 1704 sbi->prev_free = FAT_START_ENT; 1705 sb->s_maxbytes = 0xffffffff; 1706 1707 if (!sbi->fat_length && bpb.fat32_length) { 1708 struct fat_boot_fsinfo *fsinfo; 1709 struct buffer_head *fsinfo_bh; 1710 1711 /* Must be FAT32 */ 1712 sbi->fat_bits = 32; 1713 sbi->fat_length = bpb.fat32_length; 1714 sbi->root_cluster = bpb.fat32_root_cluster; 1715 1716 /* MC - if info_sector is 0, don't multiply by 0 */ 1717 sbi->fsinfo_sector = bpb.fat32_info_sector; 1718 if (sbi->fsinfo_sector == 0) 1719 sbi->fsinfo_sector = 1; 1720 1721 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1722 if (fsinfo_bh == NULL) { 1723 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1724 " (sector = %lu)", sbi->fsinfo_sector); 1725 goto out_fail; 1726 } 1727 1728 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1729 if (!IS_FSINFO(fsinfo)) { 1730 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1731 "0x%08x, 0x%08x (sector = %lu)", 1732 le32_to_cpu(fsinfo->signature1), 1733 le32_to_cpu(fsinfo->signature2), 1734 sbi->fsinfo_sector); 1735 } else { 1736 if (sbi->options.usefree) 1737 sbi->free_clus_valid = 1; 1738 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1739 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1740 } 1741 1742 brelse(fsinfo_bh); 1743 } 1744 1745 /* interpret volume ID as a little endian 32 bit integer */ 1746 if (is_fat32(sbi)) 1747 sbi->vol_id = bpb.fat32_vol_id; 1748 else /* fat 16 or 12 */ 1749 sbi->vol_id = bpb.fat16_vol_id; 1750 1751 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1752 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1753 1754 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1755 sbi->dir_entries = bpb.fat_dir_entries; 1756 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1757 if (!silent) 1758 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1759 " (%u)", sbi->dir_entries); 1760 goto out_invalid; 1761 } 1762 1763 rootdir_sectors = sbi->dir_entries 1764 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1765 sbi->data_start = sbi->dir_start + rootdir_sectors; 1766 total_sectors = bpb.fat_sectors; 1767 if (total_sectors == 0) 1768 total_sectors = bpb.fat_total_sect; 1769 1770 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1771 1772 if (!is_fat32(sbi)) 1773 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1774 1775 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1776 if (is_fat32(sbi)) 1777 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1778 else /* fat 16 or 12 */ 1779 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1780 1781 /* check that FAT table does not overflow */ 1782 fat_clusters = calc_fat_clusters(sb); 1783 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1784 if (total_clusters > max_fat(sb)) { 1785 if (!silent) 1786 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1787 total_clusters); 1788 goto out_invalid; 1789 } 1790 1791 sbi->max_cluster = total_clusters + FAT_START_ENT; 1792 /* check the free_clusters, it's not necessarily correct */ 1793 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1794 sbi->free_clusters = -1; 1795 /* check the prev_free, it's not necessarily correct */ 1796 sbi->prev_free %= sbi->max_cluster; 1797 if (sbi->prev_free < FAT_START_ENT) 1798 sbi->prev_free = FAT_START_ENT; 1799 1800 /* set up enough so that it can read an inode */ 1801 fat_hash_init(sb); 1802 dir_hash_init(sb); 1803 fat_ent_access_init(sb); 1804 1805 /* 1806 * The low byte of the first FAT entry must have the same value as 1807 * the media field of the boot sector. But in real world, too many 1808 * devices are writing wrong values. So, removed that validity check. 1809 * 1810 * The removed check compared the first FAT entry to a value dependent 1811 * on the media field like this: 1812 * == (0x0F00 | media), for FAT12 1813 * == (0XFF00 | media), for FAT16 1814 * == (0x0FFFFF | media), for FAT32 1815 */ 1816 1817 error = -EINVAL; 1818 sprintf(buf, "cp%d", sbi->options.codepage); 1819 sbi->nls_disk = load_nls(buf); 1820 if (!sbi->nls_disk) { 1821 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1822 goto out_fail; 1823 } 1824 1825 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1826 if (sbi->options.isvfat) { 1827 sbi->nls_io = load_nls(sbi->options.iocharset); 1828 if (!sbi->nls_io) { 1829 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1830 sbi->options.iocharset); 1831 goto out_fail; 1832 } 1833 } 1834 1835 error = -ENOMEM; 1836 fat_inode = new_inode(sb); 1837 if (!fat_inode) 1838 goto out_fail; 1839 fat_dummy_inode_init(fat_inode); 1840 sbi->fat_inode = fat_inode; 1841 1842 fsinfo_inode = new_inode(sb); 1843 if (!fsinfo_inode) 1844 goto out_fail; 1845 fat_dummy_inode_init(fsinfo_inode); 1846 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1847 sbi->fsinfo_inode = fsinfo_inode; 1848 insert_inode_hash(fsinfo_inode); 1849 1850 root_inode = new_inode(sb); 1851 if (!root_inode) 1852 goto out_fail; 1853 root_inode->i_ino = MSDOS_ROOT_INO; 1854 inode_set_iversion(root_inode, 1); 1855 error = fat_read_root(root_inode); 1856 if (error < 0) { 1857 iput(root_inode); 1858 goto out_fail; 1859 } 1860 error = -ENOMEM; 1861 insert_inode_hash(root_inode); 1862 fat_attach(root_inode, 0); 1863 sb->s_root = d_make_root(root_inode); 1864 if (!sb->s_root) { 1865 fat_msg(sb, KERN_ERR, "get root inode failed"); 1866 goto out_fail; 1867 } 1868 1869 if (sbi->options.discard) { 1870 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1871 if (!blk_queue_discard(q)) 1872 fat_msg(sb, KERN_WARNING, 1873 "mounting with \"discard\" option, but " 1874 "the device does not support discard"); 1875 } 1876 1877 fat_set_state(sb, 1, 0); 1878 return 0; 1879 1880 out_invalid: 1881 error = -EINVAL; 1882 if (!silent) 1883 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1884 1885 out_fail: 1886 if (fsinfo_inode) 1887 iput(fsinfo_inode); 1888 if (fat_inode) 1889 iput(fat_inode); 1890 unload_nls(sbi->nls_io); 1891 unload_nls(sbi->nls_disk); 1892 fat_reset_iocharset(&sbi->options); 1893 sb->s_fs_info = NULL; 1894 kfree(sbi); 1895 return error; 1896 } 1897 1898 EXPORT_SYMBOL_GPL(fat_fill_super); 1899 1900 /* 1901 * helper function for fat_flush_inodes. This writes both the inode 1902 * and the file data blocks, waiting for in flight data blocks before 1903 * the start of the call. It does not wait for any io started 1904 * during the call 1905 */ 1906 static int writeback_inode(struct inode *inode) 1907 { 1908 1909 int ret; 1910 1911 /* if we used wait=1, sync_inode_metadata waits for the io for the 1912 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1913 * and filemap_fdatawrite is used for the data blocks 1914 */ 1915 ret = sync_inode_metadata(inode, 0); 1916 if (!ret) 1917 ret = filemap_fdatawrite(inode->i_mapping); 1918 return ret; 1919 } 1920 1921 /* 1922 * write data and metadata corresponding to i1 and i2. The io is 1923 * started but we do not wait for any of it to finish. 1924 * 1925 * filemap_flush is used for the block device, so if there is a dirty 1926 * page for a block already in flight, we will not wait and start the 1927 * io over again 1928 */ 1929 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1930 { 1931 int ret = 0; 1932 if (!MSDOS_SB(sb)->options.flush) 1933 return 0; 1934 if (i1) 1935 ret = writeback_inode(i1); 1936 if (!ret && i2) 1937 ret = writeback_inode(i2); 1938 if (!ret) { 1939 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1940 ret = filemap_flush(mapping); 1941 } 1942 return ret; 1943 } 1944 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1945 1946 static int __init init_fat_fs(void) 1947 { 1948 int err; 1949 1950 err = fat_cache_init(); 1951 if (err) 1952 return err; 1953 1954 err = fat_init_inodecache(); 1955 if (err) 1956 goto failed; 1957 1958 return 0; 1959 1960 failed: 1961 fat_cache_destroy(); 1962 return err; 1963 } 1964 1965 static void __exit exit_fat_fs(void) 1966 { 1967 fat_cache_destroy(); 1968 fat_destroy_inodecache(); 1969 } 1970 1971 module_init(init_fat_fs) 1972 module_exit(exit_fat_fs) 1973 1974 MODULE_LICENSE("GPL"); 1975