1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/fat/inode.c 4 * 5 * Written 1992,1993 by Werner Almesberger 6 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner 7 * Rewritten for the constant inumbers support by Al Viro 8 * 9 * Fixes: 10 * 11 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0 12 */ 13 14 #include <linux/module.h> 15 #include <linux/pagemap.h> 16 #include <linux/mpage.h> 17 #include <linux/vfs.h> 18 #include <linux/seq_file.h> 19 #include <linux/parser.h> 20 #include <linux/uio.h> 21 #include <linux/blkdev.h> 22 #include <linux/backing-dev.h> 23 #include <asm/unaligned.h> 24 #include <linux/random.h> 25 #include <linux/iversion.h> 26 #include "fat.h" 27 28 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 29 /* if user don't select VFAT, this is undefined. */ 30 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 31 #endif 32 33 #define KB_IN_SECTORS 2 34 35 /* DOS dates from 1980/1/1 through 2107/12/31 */ 36 #define FAT_DATE_MIN (0<<9 | 1<<5 | 1) 37 #define FAT_DATE_MAX (127<<9 | 12<<5 | 31) 38 #define FAT_TIME_MAX (23<<11 | 59<<5 | 29) 39 40 /* 41 * A deserialized copy of the on-disk structure laid out in struct 42 * fat_boot_sector. 43 */ 44 struct fat_bios_param_block { 45 u16 fat_sector_size; 46 u8 fat_sec_per_clus; 47 u16 fat_reserved; 48 u8 fat_fats; 49 u16 fat_dir_entries; 50 u16 fat_sectors; 51 u16 fat_fat_length; 52 u32 fat_total_sect; 53 54 u8 fat16_state; 55 u32 fat16_vol_id; 56 57 u32 fat32_length; 58 u32 fat32_root_cluster; 59 u16 fat32_info_sector; 60 u8 fat32_state; 61 u32 fat32_vol_id; 62 }; 63 64 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 65 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 66 67 static struct fat_floppy_defaults { 68 unsigned nr_sectors; 69 unsigned sec_per_clus; 70 unsigned dir_entries; 71 unsigned media; 72 unsigned fat_length; 73 } floppy_defaults[] = { 74 { 75 .nr_sectors = 160 * KB_IN_SECTORS, 76 .sec_per_clus = 1, 77 .dir_entries = 64, 78 .media = 0xFE, 79 .fat_length = 1, 80 }, 81 { 82 .nr_sectors = 180 * KB_IN_SECTORS, 83 .sec_per_clus = 1, 84 .dir_entries = 64, 85 .media = 0xFC, 86 .fat_length = 2, 87 }, 88 { 89 .nr_sectors = 320 * KB_IN_SECTORS, 90 .sec_per_clus = 2, 91 .dir_entries = 112, 92 .media = 0xFF, 93 .fat_length = 1, 94 }, 95 { 96 .nr_sectors = 360 * KB_IN_SECTORS, 97 .sec_per_clus = 2, 98 .dir_entries = 112, 99 .media = 0xFD, 100 .fat_length = 2, 101 }, 102 }; 103 104 int fat_add_cluster(struct inode *inode) 105 { 106 int err, cluster; 107 108 err = fat_alloc_clusters(inode, &cluster, 1); 109 if (err) 110 return err; 111 /* FIXME: this cluster should be added after data of this 112 * cluster is writed */ 113 err = fat_chain_add(inode, cluster, 1); 114 if (err) 115 fat_free_clusters(inode, cluster); 116 return err; 117 } 118 119 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 120 unsigned long *max_blocks, 121 struct buffer_head *bh_result, int create) 122 { 123 struct super_block *sb = inode->i_sb; 124 struct msdos_sb_info *sbi = MSDOS_SB(sb); 125 unsigned long mapped_blocks; 126 sector_t phys, last_block; 127 int err, offset; 128 129 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 130 if (err) 131 return err; 132 if (phys) { 133 map_bh(bh_result, sb, phys); 134 *max_blocks = min(mapped_blocks, *max_blocks); 135 return 0; 136 } 137 if (!create) 138 return 0; 139 140 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 141 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 142 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 143 return -EIO; 144 } 145 146 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); 147 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 148 /* 149 * allocate a cluster according to the following. 150 * 1) no more available blocks 151 * 2) not part of fallocate region 152 */ 153 if (!offset && !(iblock < last_block)) { 154 /* TODO: multiple cluster allocation would be desirable. */ 155 err = fat_add_cluster(inode); 156 if (err) 157 return err; 158 } 159 /* available blocks on this cluster */ 160 mapped_blocks = sbi->sec_per_clus - offset; 161 162 *max_blocks = min(mapped_blocks, *max_blocks); 163 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 164 165 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 166 if (err) 167 return err; 168 if (!phys) { 169 fat_fs_error(sb, 170 "invalid FAT chain (i_pos %lld, last_block %llu)", 171 MSDOS_I(inode)->i_pos, 172 (unsigned long long)last_block); 173 return -EIO; 174 } 175 176 BUG_ON(*max_blocks != mapped_blocks); 177 set_buffer_new(bh_result); 178 map_bh(bh_result, sb, phys); 179 180 return 0; 181 } 182 183 static int fat_get_block(struct inode *inode, sector_t iblock, 184 struct buffer_head *bh_result, int create) 185 { 186 struct super_block *sb = inode->i_sb; 187 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 188 int err; 189 190 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 191 if (err) 192 return err; 193 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 194 return 0; 195 } 196 197 static int fat_writepage(struct page *page, struct writeback_control *wbc) 198 { 199 return block_write_full_page(page, fat_get_block, wbc); 200 } 201 202 static int fat_writepages(struct address_space *mapping, 203 struct writeback_control *wbc) 204 { 205 return mpage_writepages(mapping, wbc, fat_get_block); 206 } 207 208 static int fat_readpage(struct file *file, struct page *page) 209 { 210 return mpage_readpage(page, fat_get_block); 211 } 212 213 static int fat_readpages(struct file *file, struct address_space *mapping, 214 struct list_head *pages, unsigned nr_pages) 215 { 216 return mpage_readpages(mapping, pages, nr_pages, fat_get_block); 217 } 218 219 static void fat_write_failed(struct address_space *mapping, loff_t to) 220 { 221 struct inode *inode = mapping->host; 222 223 if (to > inode->i_size) { 224 truncate_pagecache(inode, inode->i_size); 225 fat_truncate_blocks(inode, inode->i_size); 226 } 227 } 228 229 static int fat_write_begin(struct file *file, struct address_space *mapping, 230 loff_t pos, unsigned len, unsigned flags, 231 struct page **pagep, void **fsdata) 232 { 233 int err; 234 235 *pagep = NULL; 236 err = cont_write_begin(file, mapping, pos, len, flags, 237 pagep, fsdata, fat_get_block, 238 &MSDOS_I(mapping->host)->mmu_private); 239 if (err < 0) 240 fat_write_failed(mapping, pos + len); 241 return err; 242 } 243 244 static int fat_write_end(struct file *file, struct address_space *mapping, 245 loff_t pos, unsigned len, unsigned copied, 246 struct page *pagep, void *fsdata) 247 { 248 struct inode *inode = mapping->host; 249 int err; 250 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 251 if (err < len) 252 fat_write_failed(mapping, pos + len); 253 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 254 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 255 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 256 mark_inode_dirty(inode); 257 } 258 return err; 259 } 260 261 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 262 { 263 struct file *file = iocb->ki_filp; 264 struct address_space *mapping = file->f_mapping; 265 struct inode *inode = mapping->host; 266 size_t count = iov_iter_count(iter); 267 loff_t offset = iocb->ki_pos; 268 ssize_t ret; 269 270 if (iov_iter_rw(iter) == WRITE) { 271 /* 272 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 273 * so we need to update the ->mmu_private to block boundary. 274 * 275 * But we must fill the remaining area or hole by nul for 276 * updating ->mmu_private. 277 * 278 * Return 0, and fallback to normal buffered write. 279 */ 280 loff_t size = offset + count; 281 if (MSDOS_I(inode)->mmu_private < size) 282 return 0; 283 } 284 285 /* 286 * FAT need to use the DIO_LOCKING for avoiding the race 287 * condition of fat_get_block() and ->truncate(). 288 */ 289 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 290 if (ret < 0 && iov_iter_rw(iter) == WRITE) 291 fat_write_failed(mapping, offset + count); 292 293 return ret; 294 } 295 296 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 297 struct buffer_head *bh_result, int create) 298 { 299 struct super_block *sb = inode->i_sb; 300 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 301 int err; 302 sector_t bmap; 303 unsigned long mapped_blocks; 304 305 BUG_ON(create != 0); 306 307 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 308 if (err) 309 return err; 310 311 if (bmap) { 312 map_bh(bh_result, sb, bmap); 313 max_blocks = min(mapped_blocks, max_blocks); 314 } 315 316 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 317 318 return 0; 319 } 320 321 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 322 { 323 sector_t blocknr; 324 325 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 326 down_read(&MSDOS_I(mapping->host)->truncate_lock); 327 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 328 up_read(&MSDOS_I(mapping->host)->truncate_lock); 329 330 return blocknr; 331 } 332 333 /* 334 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 335 * up to the end of the block which corresponds to `from'. 336 * This is required during truncate to physically zeroout the tail end 337 * of that block so it doesn't yield old data if the file is later grown. 338 * Also, avoid causing failure from fsx for cases of "data past EOF" 339 */ 340 int fat_block_truncate_page(struct inode *inode, loff_t from) 341 { 342 return block_truncate_page(inode->i_mapping, from, fat_get_block); 343 } 344 345 static const struct address_space_operations fat_aops = { 346 .readpage = fat_readpage, 347 .readpages = fat_readpages, 348 .writepage = fat_writepage, 349 .writepages = fat_writepages, 350 .write_begin = fat_write_begin, 351 .write_end = fat_write_end, 352 .direct_IO = fat_direct_IO, 353 .bmap = _fat_bmap 354 }; 355 356 /* 357 * New FAT inode stuff. We do the following: 358 * a) i_ino is constant and has nothing with on-disk location. 359 * b) FAT manages its own cache of directory entries. 360 * c) *This* cache is indexed by on-disk location. 361 * d) inode has an associated directory entry, all right, but 362 * it may be unhashed. 363 * e) currently entries are stored within struct inode. That should 364 * change. 365 * f) we deal with races in the following way: 366 * 1. readdir() and lookup() do FAT-dir-cache lookup. 367 * 2. rename() unhashes the F-d-c entry and rehashes it in 368 * a new place. 369 * 3. unlink() and rmdir() unhash F-d-c entry. 370 * 4. fat_write_inode() checks whether the thing is unhashed. 371 * If it is we silently return. If it isn't we do bread(), 372 * check if the location is still valid and retry if it 373 * isn't. Otherwise we do changes. 374 * 5. Spinlock is used to protect hash/unhash/location check/lookup 375 * 6. fat_evict_inode() unhashes the F-d-c entry. 376 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 377 * and consider negative result as cache miss. 378 */ 379 380 static void fat_hash_init(struct super_block *sb) 381 { 382 struct msdos_sb_info *sbi = MSDOS_SB(sb); 383 int i; 384 385 spin_lock_init(&sbi->inode_hash_lock); 386 for (i = 0; i < FAT_HASH_SIZE; i++) 387 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 388 } 389 390 static inline unsigned long fat_hash(loff_t i_pos) 391 { 392 return hash_32(i_pos, FAT_HASH_BITS); 393 } 394 395 static void dir_hash_init(struct super_block *sb) 396 { 397 struct msdos_sb_info *sbi = MSDOS_SB(sb); 398 int i; 399 400 spin_lock_init(&sbi->dir_hash_lock); 401 for (i = 0; i < FAT_HASH_SIZE; i++) 402 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 403 } 404 405 void fat_attach(struct inode *inode, loff_t i_pos) 406 { 407 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 408 409 if (inode->i_ino != MSDOS_ROOT_INO) { 410 struct hlist_head *head = sbi->inode_hashtable 411 + fat_hash(i_pos); 412 413 spin_lock(&sbi->inode_hash_lock); 414 MSDOS_I(inode)->i_pos = i_pos; 415 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 416 spin_unlock(&sbi->inode_hash_lock); 417 } 418 419 /* If NFS support is enabled, cache the mapping of start cluster 420 * to directory inode. This is used during reconnection of 421 * dentries to the filesystem root. 422 */ 423 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 424 struct hlist_head *d_head = sbi->dir_hashtable; 425 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 426 427 spin_lock(&sbi->dir_hash_lock); 428 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 429 spin_unlock(&sbi->dir_hash_lock); 430 } 431 } 432 EXPORT_SYMBOL_GPL(fat_attach); 433 434 void fat_detach(struct inode *inode) 435 { 436 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 437 spin_lock(&sbi->inode_hash_lock); 438 MSDOS_I(inode)->i_pos = 0; 439 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 440 spin_unlock(&sbi->inode_hash_lock); 441 442 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 443 spin_lock(&sbi->dir_hash_lock); 444 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 445 spin_unlock(&sbi->dir_hash_lock); 446 } 447 } 448 EXPORT_SYMBOL_GPL(fat_detach); 449 450 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 451 { 452 struct msdos_sb_info *sbi = MSDOS_SB(sb); 453 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 454 struct msdos_inode_info *i; 455 struct inode *inode = NULL; 456 457 spin_lock(&sbi->inode_hash_lock); 458 hlist_for_each_entry(i, head, i_fat_hash) { 459 BUG_ON(i->vfs_inode.i_sb != sb); 460 if (i->i_pos != i_pos) 461 continue; 462 inode = igrab(&i->vfs_inode); 463 if (inode) 464 break; 465 } 466 spin_unlock(&sbi->inode_hash_lock); 467 return inode; 468 } 469 470 static int is_exec(unsigned char *extension) 471 { 472 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 473 474 for (walk = exe_extensions; *walk; walk += 3) 475 if (!strncmp(extension, walk, 3)) 476 return 1; 477 return 0; 478 } 479 480 static int fat_calc_dir_size(struct inode *inode) 481 { 482 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 483 int ret, fclus, dclus; 484 485 inode->i_size = 0; 486 if (MSDOS_I(inode)->i_start == 0) 487 return 0; 488 489 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 490 if (ret < 0) 491 return ret; 492 inode->i_size = (fclus + 1) << sbi->cluster_bits; 493 494 return 0; 495 } 496 497 static int fat_validate_dir(struct inode *dir) 498 { 499 struct super_block *sb = dir->i_sb; 500 501 if (dir->i_nlink < 2) { 502 /* Directory should have "."/".." entries at least. */ 503 fat_fs_error(sb, "corrupted directory (invalid entries)"); 504 return -EIO; 505 } 506 if (MSDOS_I(dir)->i_start == 0 || 507 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 508 /* Directory should point valid cluster. */ 509 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 510 return -EIO; 511 } 512 return 0; 513 } 514 515 /* doesn't deal with root inode */ 516 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 517 { 518 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 519 int error; 520 521 MSDOS_I(inode)->i_pos = 0; 522 inode->i_uid = sbi->options.fs_uid; 523 inode->i_gid = sbi->options.fs_gid; 524 inode_inc_iversion(inode); 525 inode->i_generation = prandom_u32(); 526 527 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 528 inode->i_generation &= ~1; 529 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 530 inode->i_op = sbi->dir_ops; 531 inode->i_fop = &fat_dir_operations; 532 533 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 534 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 535 error = fat_calc_dir_size(inode); 536 if (error < 0) 537 return error; 538 MSDOS_I(inode)->mmu_private = inode->i_size; 539 540 set_nlink(inode, fat_subdirs(inode)); 541 542 error = fat_validate_dir(inode); 543 if (error < 0) 544 return error; 545 } else { /* not a directory */ 546 inode->i_generation |= 1; 547 inode->i_mode = fat_make_mode(sbi, de->attr, 548 ((sbi->options.showexec && !is_exec(de->name + 8)) 549 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 550 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 551 552 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 553 inode->i_size = le32_to_cpu(de->size); 554 inode->i_op = &fat_file_inode_operations; 555 inode->i_fop = &fat_file_operations; 556 inode->i_mapping->a_ops = &fat_aops; 557 MSDOS_I(inode)->mmu_private = inode->i_size; 558 } 559 if (de->attr & ATTR_SYS) { 560 if (sbi->options.sys_immutable) 561 inode->i_flags |= S_IMMUTABLE; 562 } 563 fat_save_attrs(inode, de->attr); 564 565 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 566 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 567 568 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 569 if (sbi->options.isvfat) { 570 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 571 de->cdate, de->ctime_cs); 572 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 573 } else 574 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME); 575 576 return 0; 577 } 578 579 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 580 { 581 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 582 mutex_lock(&sbi->nfs_build_inode_lock); 583 } 584 585 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 586 { 587 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 588 mutex_unlock(&sbi->nfs_build_inode_lock); 589 } 590 591 struct inode *fat_build_inode(struct super_block *sb, 592 struct msdos_dir_entry *de, loff_t i_pos) 593 { 594 struct inode *inode; 595 int err; 596 597 fat_lock_build_inode(MSDOS_SB(sb)); 598 inode = fat_iget(sb, i_pos); 599 if (inode) 600 goto out; 601 inode = new_inode(sb); 602 if (!inode) { 603 inode = ERR_PTR(-ENOMEM); 604 goto out; 605 } 606 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 607 inode_set_iversion(inode, 1); 608 err = fat_fill_inode(inode, de); 609 if (err) { 610 iput(inode); 611 inode = ERR_PTR(err); 612 goto out; 613 } 614 fat_attach(inode, i_pos); 615 insert_inode_hash(inode); 616 out: 617 fat_unlock_build_inode(MSDOS_SB(sb)); 618 return inode; 619 } 620 621 EXPORT_SYMBOL_GPL(fat_build_inode); 622 623 static int __fat_write_inode(struct inode *inode, int wait); 624 625 static void fat_free_eofblocks(struct inode *inode) 626 { 627 /* Release unwritten fallocated blocks on inode eviction. */ 628 if ((inode->i_blocks << 9) > 629 round_up(MSDOS_I(inode)->mmu_private, 630 MSDOS_SB(inode->i_sb)->cluster_size)) { 631 int err; 632 633 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 634 /* Fallocate results in updating the i_start/iogstart 635 * for the zero byte file. So, make it return to 636 * original state during evict and commit it to avoid 637 * any corruption on the next access to the cluster 638 * chain for the file. 639 */ 640 err = __fat_write_inode(inode, inode_needs_sync(inode)); 641 if (err) { 642 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 643 "update on disk inode for unused " 644 "fallocated blocks, inode could be " 645 "corrupted. Please run fsck"); 646 } 647 648 } 649 } 650 651 static void fat_evict_inode(struct inode *inode) 652 { 653 truncate_inode_pages_final(&inode->i_data); 654 if (!inode->i_nlink) { 655 inode->i_size = 0; 656 fat_truncate_blocks(inode, 0); 657 } else 658 fat_free_eofblocks(inode); 659 660 invalidate_inode_buffers(inode); 661 clear_inode(inode); 662 fat_cache_inval_inode(inode); 663 fat_detach(inode); 664 } 665 666 static void fat_set_state(struct super_block *sb, 667 unsigned int set, unsigned int force) 668 { 669 struct buffer_head *bh; 670 struct fat_boot_sector *b; 671 struct msdos_sb_info *sbi = MSDOS_SB(sb); 672 673 /* do not change any thing if mounted read only */ 674 if (sb_rdonly(sb) && !force) 675 return; 676 677 /* do not change state if fs was dirty */ 678 if (sbi->dirty) { 679 /* warn only on set (mount). */ 680 if (set) 681 fat_msg(sb, KERN_WARNING, "Volume was not properly " 682 "unmounted. Some data may be corrupt. " 683 "Please run fsck."); 684 return; 685 } 686 687 bh = sb_bread(sb, 0); 688 if (bh == NULL) { 689 fat_msg(sb, KERN_ERR, "unable to read boot sector " 690 "to mark fs as dirty"); 691 return; 692 } 693 694 b = (struct fat_boot_sector *) bh->b_data; 695 696 if (is_fat32(sbi)) { 697 if (set) 698 b->fat32.state |= FAT_STATE_DIRTY; 699 else 700 b->fat32.state &= ~FAT_STATE_DIRTY; 701 } else /* fat 16 and 12 */ { 702 if (set) 703 b->fat16.state |= FAT_STATE_DIRTY; 704 else 705 b->fat16.state &= ~FAT_STATE_DIRTY; 706 } 707 708 mark_buffer_dirty(bh); 709 sync_dirty_buffer(bh); 710 brelse(bh); 711 } 712 713 static void fat_reset_iocharset(struct fat_mount_options *opts) 714 { 715 if (opts->iocharset != fat_default_iocharset) { 716 /* Note: opts->iocharset can be NULL here */ 717 kfree(opts->iocharset); 718 opts->iocharset = fat_default_iocharset; 719 } 720 } 721 722 static void delayed_free(struct rcu_head *p) 723 { 724 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 725 unload_nls(sbi->nls_disk); 726 unload_nls(sbi->nls_io); 727 fat_reset_iocharset(&sbi->options); 728 kfree(sbi); 729 } 730 731 static void fat_put_super(struct super_block *sb) 732 { 733 struct msdos_sb_info *sbi = MSDOS_SB(sb); 734 735 fat_set_state(sb, 0, 0); 736 737 iput(sbi->fsinfo_inode); 738 iput(sbi->fat_inode); 739 740 call_rcu(&sbi->rcu, delayed_free); 741 } 742 743 static struct kmem_cache *fat_inode_cachep; 744 745 static struct inode *fat_alloc_inode(struct super_block *sb) 746 { 747 struct msdos_inode_info *ei; 748 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 749 if (!ei) 750 return NULL; 751 752 init_rwsem(&ei->truncate_lock); 753 /* Zeroing to allow iput() even if partial initialized inode. */ 754 ei->mmu_private = 0; 755 ei->i_start = 0; 756 ei->i_logstart = 0; 757 ei->i_attrs = 0; 758 ei->i_pos = 0; 759 760 return &ei->vfs_inode; 761 } 762 763 static void fat_free_inode(struct inode *inode) 764 { 765 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 766 } 767 768 static void init_once(void *foo) 769 { 770 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 771 772 spin_lock_init(&ei->cache_lru_lock); 773 ei->nr_caches = 0; 774 ei->cache_valid_id = FAT_CACHE_VALID + 1; 775 INIT_LIST_HEAD(&ei->cache_lru); 776 INIT_HLIST_NODE(&ei->i_fat_hash); 777 INIT_HLIST_NODE(&ei->i_dir_hash); 778 inode_init_once(&ei->vfs_inode); 779 } 780 781 static int __init fat_init_inodecache(void) 782 { 783 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 784 sizeof(struct msdos_inode_info), 785 0, (SLAB_RECLAIM_ACCOUNT| 786 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 787 init_once); 788 if (fat_inode_cachep == NULL) 789 return -ENOMEM; 790 return 0; 791 } 792 793 static void __exit fat_destroy_inodecache(void) 794 { 795 /* 796 * Make sure all delayed rcu free inodes are flushed before we 797 * destroy cache. 798 */ 799 rcu_barrier(); 800 kmem_cache_destroy(fat_inode_cachep); 801 } 802 803 static int fat_remount(struct super_block *sb, int *flags, char *data) 804 { 805 bool new_rdonly; 806 struct msdos_sb_info *sbi = MSDOS_SB(sb); 807 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 808 809 sync_filesystem(sb); 810 811 /* make sure we update state on remount. */ 812 new_rdonly = *flags & SB_RDONLY; 813 if (new_rdonly != sb_rdonly(sb)) { 814 if (new_rdonly) 815 fat_set_state(sb, 0, 0); 816 else 817 fat_set_state(sb, 1, 1); 818 } 819 return 0; 820 } 821 822 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 823 { 824 struct super_block *sb = dentry->d_sb; 825 struct msdos_sb_info *sbi = MSDOS_SB(sb); 826 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 827 828 /* If the count of free cluster is still unknown, counts it here. */ 829 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 830 int err = fat_count_free_clusters(dentry->d_sb); 831 if (err) 832 return err; 833 } 834 835 buf->f_type = dentry->d_sb->s_magic; 836 buf->f_bsize = sbi->cluster_size; 837 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 838 buf->f_bfree = sbi->free_clusters; 839 buf->f_bavail = sbi->free_clusters; 840 buf->f_fsid.val[0] = (u32)id; 841 buf->f_fsid.val[1] = (u32)(id >> 32); 842 buf->f_namelen = 843 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 844 845 return 0; 846 } 847 848 static int __fat_write_inode(struct inode *inode, int wait) 849 { 850 struct super_block *sb = inode->i_sb; 851 struct msdos_sb_info *sbi = MSDOS_SB(sb); 852 struct buffer_head *bh; 853 struct msdos_dir_entry *raw_entry; 854 loff_t i_pos; 855 sector_t blocknr; 856 int err, offset; 857 858 if (inode->i_ino == MSDOS_ROOT_INO) 859 return 0; 860 861 retry: 862 i_pos = fat_i_pos_read(sbi, inode); 863 if (!i_pos) 864 return 0; 865 866 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 867 bh = sb_bread(sb, blocknr); 868 if (!bh) { 869 fat_msg(sb, KERN_ERR, "unable to read inode block " 870 "for updating (i_pos %lld)", i_pos); 871 return -EIO; 872 } 873 spin_lock(&sbi->inode_hash_lock); 874 if (i_pos != MSDOS_I(inode)->i_pos) { 875 spin_unlock(&sbi->inode_hash_lock); 876 brelse(bh); 877 goto retry; 878 } 879 880 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 881 if (S_ISDIR(inode->i_mode)) 882 raw_entry->size = 0; 883 else 884 raw_entry->size = cpu_to_le32(inode->i_size); 885 raw_entry->attr = fat_make_attrs(inode); 886 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 887 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 888 &raw_entry->date, NULL); 889 if (sbi->options.isvfat) { 890 __le16 atime; 891 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 892 &raw_entry->cdate, &raw_entry->ctime_cs); 893 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 894 &raw_entry->adate, NULL); 895 } 896 spin_unlock(&sbi->inode_hash_lock); 897 mark_buffer_dirty(bh); 898 err = 0; 899 if (wait) 900 err = sync_dirty_buffer(bh); 901 brelse(bh); 902 return err; 903 } 904 905 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 906 { 907 int err; 908 909 if (inode->i_ino == MSDOS_FSINFO_INO) { 910 struct super_block *sb = inode->i_sb; 911 912 mutex_lock(&MSDOS_SB(sb)->s_lock); 913 err = fat_clusters_flush(sb); 914 mutex_unlock(&MSDOS_SB(sb)->s_lock); 915 } else 916 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 917 918 return err; 919 } 920 921 int fat_sync_inode(struct inode *inode) 922 { 923 return __fat_write_inode(inode, 1); 924 } 925 926 EXPORT_SYMBOL_GPL(fat_sync_inode); 927 928 static int fat_show_options(struct seq_file *m, struct dentry *root); 929 static const struct super_operations fat_sops = { 930 .alloc_inode = fat_alloc_inode, 931 .free_inode = fat_free_inode, 932 .write_inode = fat_write_inode, 933 .evict_inode = fat_evict_inode, 934 .put_super = fat_put_super, 935 .statfs = fat_statfs, 936 .remount_fs = fat_remount, 937 938 .show_options = fat_show_options, 939 }; 940 941 static int fat_show_options(struct seq_file *m, struct dentry *root) 942 { 943 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 944 struct fat_mount_options *opts = &sbi->options; 945 int isvfat = opts->isvfat; 946 947 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 948 seq_printf(m, ",uid=%u", 949 from_kuid_munged(&init_user_ns, opts->fs_uid)); 950 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 951 seq_printf(m, ",gid=%u", 952 from_kgid_munged(&init_user_ns, opts->fs_gid)); 953 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 954 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 955 if (opts->allow_utime) 956 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 957 if (sbi->nls_disk) 958 /* strip "cp" prefix from displayed option */ 959 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 960 if (isvfat) { 961 if (sbi->nls_io) 962 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 963 964 switch (opts->shortname) { 965 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 966 seq_puts(m, ",shortname=win95"); 967 break; 968 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 969 seq_puts(m, ",shortname=winnt"); 970 break; 971 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 972 seq_puts(m, ",shortname=mixed"); 973 break; 974 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 975 seq_puts(m, ",shortname=lower"); 976 break; 977 default: 978 seq_puts(m, ",shortname=unknown"); 979 break; 980 } 981 } 982 if (opts->name_check != 'n') 983 seq_printf(m, ",check=%c", opts->name_check); 984 if (opts->usefree) 985 seq_puts(m, ",usefree"); 986 if (opts->quiet) 987 seq_puts(m, ",quiet"); 988 if (opts->showexec) 989 seq_puts(m, ",showexec"); 990 if (opts->sys_immutable) 991 seq_puts(m, ",sys_immutable"); 992 if (!isvfat) { 993 if (opts->dotsOK) 994 seq_puts(m, ",dotsOK=yes"); 995 if (opts->nocase) 996 seq_puts(m, ",nocase"); 997 } else { 998 if (opts->utf8) 999 seq_puts(m, ",utf8"); 1000 if (opts->unicode_xlate) 1001 seq_puts(m, ",uni_xlate"); 1002 if (!opts->numtail) 1003 seq_puts(m, ",nonumtail"); 1004 if (opts->rodir) 1005 seq_puts(m, ",rodir"); 1006 } 1007 if (opts->flush) 1008 seq_puts(m, ",flush"); 1009 if (opts->tz_set) { 1010 if (opts->time_offset) 1011 seq_printf(m, ",time_offset=%d", opts->time_offset); 1012 else 1013 seq_puts(m, ",tz=UTC"); 1014 } 1015 if (opts->errors == FAT_ERRORS_CONT) 1016 seq_puts(m, ",errors=continue"); 1017 else if (opts->errors == FAT_ERRORS_PANIC) 1018 seq_puts(m, ",errors=panic"); 1019 else 1020 seq_puts(m, ",errors=remount-ro"); 1021 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1022 seq_puts(m, ",nfs=nostale_ro"); 1023 else if (opts->nfs) 1024 seq_puts(m, ",nfs=stale_rw"); 1025 if (opts->discard) 1026 seq_puts(m, ",discard"); 1027 if (opts->dos1xfloppy) 1028 seq_puts(m, ",dos1xfloppy"); 1029 1030 return 0; 1031 } 1032 1033 enum { 1034 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1035 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1036 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1037 Opt_immutable, Opt_dots, Opt_nodots, 1038 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1039 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1040 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1041 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1042 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1043 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1044 }; 1045 1046 static const match_table_t fat_tokens = { 1047 {Opt_check_r, "check=relaxed"}, 1048 {Opt_check_s, "check=strict"}, 1049 {Opt_check_n, "check=normal"}, 1050 {Opt_check_r, "check=r"}, 1051 {Opt_check_s, "check=s"}, 1052 {Opt_check_n, "check=n"}, 1053 {Opt_uid, "uid=%u"}, 1054 {Opt_gid, "gid=%u"}, 1055 {Opt_umask, "umask=%o"}, 1056 {Opt_dmask, "dmask=%o"}, 1057 {Opt_fmask, "fmask=%o"}, 1058 {Opt_allow_utime, "allow_utime=%o"}, 1059 {Opt_codepage, "codepage=%u"}, 1060 {Opt_usefree, "usefree"}, 1061 {Opt_nocase, "nocase"}, 1062 {Opt_quiet, "quiet"}, 1063 {Opt_showexec, "showexec"}, 1064 {Opt_debug, "debug"}, 1065 {Opt_immutable, "sys_immutable"}, 1066 {Opt_flush, "flush"}, 1067 {Opt_tz_utc, "tz=UTC"}, 1068 {Opt_time_offset, "time_offset=%d"}, 1069 {Opt_err_cont, "errors=continue"}, 1070 {Opt_err_panic, "errors=panic"}, 1071 {Opt_err_ro, "errors=remount-ro"}, 1072 {Opt_discard, "discard"}, 1073 {Opt_nfs_stale_rw, "nfs"}, 1074 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1075 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1076 {Opt_dos1xfloppy, "dos1xfloppy"}, 1077 {Opt_obsolete, "conv=binary"}, 1078 {Opt_obsolete, "conv=text"}, 1079 {Opt_obsolete, "conv=auto"}, 1080 {Opt_obsolete, "conv=b"}, 1081 {Opt_obsolete, "conv=t"}, 1082 {Opt_obsolete, "conv=a"}, 1083 {Opt_obsolete, "fat=%u"}, 1084 {Opt_obsolete, "blocksize=%u"}, 1085 {Opt_obsolete, "cvf_format=%20s"}, 1086 {Opt_obsolete, "cvf_options=%100s"}, 1087 {Opt_obsolete, "posix"}, 1088 {Opt_err, NULL}, 1089 }; 1090 static const match_table_t msdos_tokens = { 1091 {Opt_nodots, "nodots"}, 1092 {Opt_nodots, "dotsOK=no"}, 1093 {Opt_dots, "dots"}, 1094 {Opt_dots, "dotsOK=yes"}, 1095 {Opt_err, NULL} 1096 }; 1097 static const match_table_t vfat_tokens = { 1098 {Opt_charset, "iocharset=%s"}, 1099 {Opt_shortname_lower, "shortname=lower"}, 1100 {Opt_shortname_win95, "shortname=win95"}, 1101 {Opt_shortname_winnt, "shortname=winnt"}, 1102 {Opt_shortname_mixed, "shortname=mixed"}, 1103 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1104 {Opt_utf8_no, "utf8=no"}, 1105 {Opt_utf8_no, "utf8=false"}, 1106 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1107 {Opt_utf8_yes, "utf8=yes"}, 1108 {Opt_utf8_yes, "utf8=true"}, 1109 {Opt_utf8_yes, "utf8"}, 1110 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1111 {Opt_uni_xl_no, "uni_xlate=no"}, 1112 {Opt_uni_xl_no, "uni_xlate=false"}, 1113 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1114 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1115 {Opt_uni_xl_yes, "uni_xlate=true"}, 1116 {Opt_uni_xl_yes, "uni_xlate"}, 1117 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1118 {Opt_nonumtail_no, "nonumtail=no"}, 1119 {Opt_nonumtail_no, "nonumtail=false"}, 1120 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1121 {Opt_nonumtail_yes, "nonumtail=yes"}, 1122 {Opt_nonumtail_yes, "nonumtail=true"}, 1123 {Opt_nonumtail_yes, "nonumtail"}, 1124 {Opt_rodir, "rodir"}, 1125 {Opt_err, NULL} 1126 }; 1127 1128 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1129 int silent, int *debug, struct fat_mount_options *opts) 1130 { 1131 char *p; 1132 substring_t args[MAX_OPT_ARGS]; 1133 int option; 1134 char *iocharset; 1135 1136 opts->isvfat = is_vfat; 1137 1138 opts->fs_uid = current_uid(); 1139 opts->fs_gid = current_gid(); 1140 opts->fs_fmask = opts->fs_dmask = current_umask(); 1141 opts->allow_utime = -1; 1142 opts->codepage = fat_default_codepage; 1143 fat_reset_iocharset(opts); 1144 if (is_vfat) { 1145 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1146 opts->rodir = 0; 1147 } else { 1148 opts->shortname = 0; 1149 opts->rodir = 1; 1150 } 1151 opts->name_check = 'n'; 1152 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1153 opts->unicode_xlate = 0; 1154 opts->numtail = 1; 1155 opts->usefree = opts->nocase = 0; 1156 opts->tz_set = 0; 1157 opts->nfs = 0; 1158 opts->errors = FAT_ERRORS_RO; 1159 *debug = 0; 1160 1161 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1162 1163 if (!options) 1164 goto out; 1165 1166 while ((p = strsep(&options, ",")) != NULL) { 1167 int token; 1168 if (!*p) 1169 continue; 1170 1171 token = match_token(p, fat_tokens, args); 1172 if (token == Opt_err) { 1173 if (is_vfat) 1174 token = match_token(p, vfat_tokens, args); 1175 else 1176 token = match_token(p, msdos_tokens, args); 1177 } 1178 switch (token) { 1179 case Opt_check_s: 1180 opts->name_check = 's'; 1181 break; 1182 case Opt_check_r: 1183 opts->name_check = 'r'; 1184 break; 1185 case Opt_check_n: 1186 opts->name_check = 'n'; 1187 break; 1188 case Opt_usefree: 1189 opts->usefree = 1; 1190 break; 1191 case Opt_nocase: 1192 if (!is_vfat) 1193 opts->nocase = 1; 1194 else { 1195 /* for backward compatibility */ 1196 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1197 | VFAT_SFN_CREATE_WIN95; 1198 } 1199 break; 1200 case Opt_quiet: 1201 opts->quiet = 1; 1202 break; 1203 case Opt_showexec: 1204 opts->showexec = 1; 1205 break; 1206 case Opt_debug: 1207 *debug = 1; 1208 break; 1209 case Opt_immutable: 1210 opts->sys_immutable = 1; 1211 break; 1212 case Opt_uid: 1213 if (match_int(&args[0], &option)) 1214 return -EINVAL; 1215 opts->fs_uid = make_kuid(current_user_ns(), option); 1216 if (!uid_valid(opts->fs_uid)) 1217 return -EINVAL; 1218 break; 1219 case Opt_gid: 1220 if (match_int(&args[0], &option)) 1221 return -EINVAL; 1222 opts->fs_gid = make_kgid(current_user_ns(), option); 1223 if (!gid_valid(opts->fs_gid)) 1224 return -EINVAL; 1225 break; 1226 case Opt_umask: 1227 if (match_octal(&args[0], &option)) 1228 return -EINVAL; 1229 opts->fs_fmask = opts->fs_dmask = option; 1230 break; 1231 case Opt_dmask: 1232 if (match_octal(&args[0], &option)) 1233 return -EINVAL; 1234 opts->fs_dmask = option; 1235 break; 1236 case Opt_fmask: 1237 if (match_octal(&args[0], &option)) 1238 return -EINVAL; 1239 opts->fs_fmask = option; 1240 break; 1241 case Opt_allow_utime: 1242 if (match_octal(&args[0], &option)) 1243 return -EINVAL; 1244 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1245 break; 1246 case Opt_codepage: 1247 if (match_int(&args[0], &option)) 1248 return -EINVAL; 1249 opts->codepage = option; 1250 break; 1251 case Opt_flush: 1252 opts->flush = 1; 1253 break; 1254 case Opt_time_offset: 1255 if (match_int(&args[0], &option)) 1256 return -EINVAL; 1257 /* 1258 * GMT+-12 zones may have DST corrections so at least 1259 * 13 hours difference is needed. Make the limit 24 1260 * just in case someone invents something unusual. 1261 */ 1262 if (option < -24 * 60 || option > 24 * 60) 1263 return -EINVAL; 1264 opts->tz_set = 1; 1265 opts->time_offset = option; 1266 break; 1267 case Opt_tz_utc: 1268 opts->tz_set = 1; 1269 opts->time_offset = 0; 1270 break; 1271 case Opt_err_cont: 1272 opts->errors = FAT_ERRORS_CONT; 1273 break; 1274 case Opt_err_panic: 1275 opts->errors = FAT_ERRORS_PANIC; 1276 break; 1277 case Opt_err_ro: 1278 opts->errors = FAT_ERRORS_RO; 1279 break; 1280 case Opt_nfs_stale_rw: 1281 opts->nfs = FAT_NFS_STALE_RW; 1282 break; 1283 case Opt_nfs_nostale_ro: 1284 opts->nfs = FAT_NFS_NOSTALE_RO; 1285 break; 1286 case Opt_dos1xfloppy: 1287 opts->dos1xfloppy = 1; 1288 break; 1289 1290 /* msdos specific */ 1291 case Opt_dots: 1292 opts->dotsOK = 1; 1293 break; 1294 case Opt_nodots: 1295 opts->dotsOK = 0; 1296 break; 1297 1298 /* vfat specific */ 1299 case Opt_charset: 1300 fat_reset_iocharset(opts); 1301 iocharset = match_strdup(&args[0]); 1302 if (!iocharset) 1303 return -ENOMEM; 1304 opts->iocharset = iocharset; 1305 break; 1306 case Opt_shortname_lower: 1307 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1308 | VFAT_SFN_CREATE_WIN95; 1309 break; 1310 case Opt_shortname_win95: 1311 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1312 | VFAT_SFN_CREATE_WIN95; 1313 break; 1314 case Opt_shortname_winnt: 1315 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1316 | VFAT_SFN_CREATE_WINNT; 1317 break; 1318 case Opt_shortname_mixed: 1319 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1320 | VFAT_SFN_CREATE_WIN95; 1321 break; 1322 case Opt_utf8_no: /* 0 or no or false */ 1323 opts->utf8 = 0; 1324 break; 1325 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1326 opts->utf8 = 1; 1327 break; 1328 case Opt_uni_xl_no: /* 0 or no or false */ 1329 opts->unicode_xlate = 0; 1330 break; 1331 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1332 opts->unicode_xlate = 1; 1333 break; 1334 case Opt_nonumtail_no: /* 0 or no or false */ 1335 opts->numtail = 1; /* negated option */ 1336 break; 1337 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1338 opts->numtail = 0; /* negated option */ 1339 break; 1340 case Opt_rodir: 1341 opts->rodir = 1; 1342 break; 1343 case Opt_discard: 1344 opts->discard = 1; 1345 break; 1346 1347 /* obsolete mount options */ 1348 case Opt_obsolete: 1349 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1350 "not supported now", p); 1351 break; 1352 /* unknown option */ 1353 default: 1354 if (!silent) { 1355 fat_msg(sb, KERN_ERR, 1356 "Unrecognized mount option \"%s\" " 1357 "or missing value", p); 1358 } 1359 return -EINVAL; 1360 } 1361 } 1362 1363 out: 1364 /* UTF-8 doesn't provide FAT semantics */ 1365 if (!strcmp(opts->iocharset, "utf8")) { 1366 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1367 " for FAT filesystems, filesystem will be " 1368 "case sensitive!"); 1369 } 1370 1371 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1372 if (opts->allow_utime == (unsigned short)-1) 1373 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1374 if (opts->unicode_xlate) 1375 opts->utf8 = 0; 1376 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1377 sb->s_flags |= SB_RDONLY; 1378 sb->s_export_op = &fat_export_ops_nostale; 1379 } 1380 1381 return 0; 1382 } 1383 1384 static int fat_read_root(struct inode *inode) 1385 { 1386 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1387 int error; 1388 1389 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1390 inode->i_uid = sbi->options.fs_uid; 1391 inode->i_gid = sbi->options.fs_gid; 1392 inode_inc_iversion(inode); 1393 inode->i_generation = 0; 1394 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1395 inode->i_op = sbi->dir_ops; 1396 inode->i_fop = &fat_dir_operations; 1397 if (is_fat32(sbi)) { 1398 MSDOS_I(inode)->i_start = sbi->root_cluster; 1399 error = fat_calc_dir_size(inode); 1400 if (error < 0) 1401 return error; 1402 } else { 1403 MSDOS_I(inode)->i_start = 0; 1404 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1405 } 1406 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1407 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1408 MSDOS_I(inode)->i_logstart = 0; 1409 MSDOS_I(inode)->mmu_private = inode->i_size; 1410 1411 fat_save_attrs(inode, ATTR_DIR); 1412 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1413 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1414 set_nlink(inode, fat_subdirs(inode)+2); 1415 1416 return 0; 1417 } 1418 1419 static unsigned long calc_fat_clusters(struct super_block *sb) 1420 { 1421 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1422 1423 /* Divide first to avoid overflow */ 1424 if (!is_fat12(sbi)) { 1425 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1426 return ent_per_sec * sbi->fat_length; 1427 } 1428 1429 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1430 } 1431 1432 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1433 { 1434 if (get_unaligned_le16(&b->sector_size)) 1435 return false; 1436 if (b->sec_per_clus) 1437 return false; 1438 if (b->reserved) 1439 return false; 1440 if (b->fats) 1441 return false; 1442 if (get_unaligned_le16(&b->dir_entries)) 1443 return false; 1444 if (get_unaligned_le16(&b->sectors)) 1445 return false; 1446 if (b->media) 1447 return false; 1448 if (b->fat_length) 1449 return false; 1450 if (b->secs_track) 1451 return false; 1452 if (b->heads) 1453 return false; 1454 return true; 1455 } 1456 1457 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1458 int silent, struct fat_bios_param_block *bpb) 1459 { 1460 int error = -EINVAL; 1461 1462 /* Read in BPB ... */ 1463 memset(bpb, 0, sizeof(*bpb)); 1464 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1465 bpb->fat_sec_per_clus = b->sec_per_clus; 1466 bpb->fat_reserved = le16_to_cpu(b->reserved); 1467 bpb->fat_fats = b->fats; 1468 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1469 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1470 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1471 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1472 1473 bpb->fat16_state = b->fat16.state; 1474 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1475 1476 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1477 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1478 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1479 bpb->fat32_state = b->fat32.state; 1480 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1481 1482 /* Validate this looks like a FAT filesystem BPB */ 1483 if (!bpb->fat_reserved) { 1484 if (!silent) 1485 fat_msg(sb, KERN_ERR, 1486 "bogus number of reserved sectors"); 1487 goto out; 1488 } 1489 if (!bpb->fat_fats) { 1490 if (!silent) 1491 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1492 goto out; 1493 } 1494 1495 /* 1496 * Earlier we checked here that b->secs_track and b->head are nonzero, 1497 * but it turns out valid FAT filesystems can have zero there. 1498 */ 1499 1500 if (!fat_valid_media(b->media)) { 1501 if (!silent) 1502 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1503 (unsigned)b->media); 1504 goto out; 1505 } 1506 1507 if (!is_power_of_2(bpb->fat_sector_size) 1508 || (bpb->fat_sector_size < 512) 1509 || (bpb->fat_sector_size > 4096)) { 1510 if (!silent) 1511 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1512 (unsigned)bpb->fat_sector_size); 1513 goto out; 1514 } 1515 1516 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1517 if (!silent) 1518 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1519 (unsigned)bpb->fat_sec_per_clus); 1520 goto out; 1521 } 1522 1523 error = 0; 1524 1525 out: 1526 return error; 1527 } 1528 1529 static int fat_read_static_bpb(struct super_block *sb, 1530 struct fat_boot_sector *b, int silent, 1531 struct fat_bios_param_block *bpb) 1532 { 1533 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1534 1535 struct fat_floppy_defaults *fdefaults = NULL; 1536 int error = -EINVAL; 1537 sector_t bd_sects; 1538 unsigned i; 1539 1540 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1541 1542 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1543 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1544 if (!silent) 1545 fat_msg(sb, KERN_ERR, 1546 "%s; no bootstrapping code", notdos1x); 1547 goto out; 1548 } 1549 1550 /* 1551 * If any value in this region is non-zero, it isn't archaic 1552 * DOS. 1553 */ 1554 if (!fat_bpb_is_zero(b)) { 1555 if (!silent) 1556 fat_msg(sb, KERN_ERR, 1557 "%s; DOS 2.x BPB is non-zero", notdos1x); 1558 goto out; 1559 } 1560 1561 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1562 if (floppy_defaults[i].nr_sectors == bd_sects) { 1563 fdefaults = &floppy_defaults[i]; 1564 break; 1565 } 1566 } 1567 1568 if (fdefaults == NULL) { 1569 if (!silent) 1570 fat_msg(sb, KERN_WARNING, 1571 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1572 (u64)bd_sects); 1573 goto out; 1574 } 1575 1576 if (!silent) 1577 fat_msg(sb, KERN_INFO, 1578 "This looks like a DOS 1.x volume; assuming default BPB values"); 1579 1580 memset(bpb, 0, sizeof(*bpb)); 1581 bpb->fat_sector_size = SECTOR_SIZE; 1582 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1583 bpb->fat_reserved = 1; 1584 bpb->fat_fats = 2; 1585 bpb->fat_dir_entries = fdefaults->dir_entries; 1586 bpb->fat_sectors = fdefaults->nr_sectors; 1587 bpb->fat_fat_length = fdefaults->fat_length; 1588 1589 error = 0; 1590 1591 out: 1592 return error; 1593 } 1594 1595 /* 1596 * Read the super block of an MS-DOS FS. 1597 */ 1598 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1599 void (*setup)(struct super_block *)) 1600 { 1601 struct inode *root_inode = NULL, *fat_inode = NULL; 1602 struct inode *fsinfo_inode = NULL; 1603 struct buffer_head *bh; 1604 struct fat_bios_param_block bpb; 1605 struct msdos_sb_info *sbi; 1606 u16 logical_sector_size; 1607 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1608 int debug; 1609 long error; 1610 char buf[50]; 1611 struct timespec64 ts; 1612 1613 /* 1614 * GFP_KERNEL is ok here, because while we do hold the 1615 * superblock lock, memory pressure can't call back into 1616 * the filesystem, since we're only just about to mount 1617 * it and have no inodes etc active! 1618 */ 1619 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1620 if (!sbi) 1621 return -ENOMEM; 1622 sb->s_fs_info = sbi; 1623 1624 sb->s_flags |= SB_NODIRATIME; 1625 sb->s_magic = MSDOS_SUPER_MAGIC; 1626 sb->s_op = &fat_sops; 1627 sb->s_export_op = &fat_export_ops; 1628 /* 1629 * fat timestamps are complex and truncated by fat itself, so 1630 * we set 1 here to be fast 1631 */ 1632 sb->s_time_gran = 1; 1633 mutex_init(&sbi->nfs_build_inode_lock); 1634 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1635 DEFAULT_RATELIMIT_BURST); 1636 1637 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1638 if (error) 1639 goto out_fail; 1640 1641 setup(sb); /* flavour-specific stuff that needs options */ 1642 1643 error = -EIO; 1644 sb_min_blocksize(sb, 512); 1645 bh = sb_bread(sb, 0); 1646 if (bh == NULL) { 1647 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1648 goto out_fail; 1649 } 1650 1651 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1652 &bpb); 1653 if (error == -EINVAL && sbi->options.dos1xfloppy) 1654 error = fat_read_static_bpb(sb, 1655 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1656 brelse(bh); 1657 1658 if (error == -EINVAL) 1659 goto out_invalid; 1660 else if (error) 1661 goto out_fail; 1662 1663 logical_sector_size = bpb.fat_sector_size; 1664 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1665 1666 error = -EIO; 1667 if (logical_sector_size < sb->s_blocksize) { 1668 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1669 " (logical sector size = %u)", logical_sector_size); 1670 goto out_fail; 1671 } 1672 1673 if (logical_sector_size > sb->s_blocksize) { 1674 struct buffer_head *bh_resize; 1675 1676 if (!sb_set_blocksize(sb, logical_sector_size)) { 1677 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1678 logical_sector_size); 1679 goto out_fail; 1680 } 1681 1682 /* Verify that the larger boot sector is fully readable */ 1683 bh_resize = sb_bread(sb, 0); 1684 if (bh_resize == NULL) { 1685 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1686 " (logical sector size = %lu)", 1687 sb->s_blocksize); 1688 goto out_fail; 1689 } 1690 brelse(bh_resize); 1691 } 1692 1693 mutex_init(&sbi->s_lock); 1694 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1695 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1696 sbi->fats = bpb.fat_fats; 1697 sbi->fat_bits = 0; /* Don't know yet */ 1698 sbi->fat_start = bpb.fat_reserved; 1699 sbi->fat_length = bpb.fat_fat_length; 1700 sbi->root_cluster = 0; 1701 sbi->free_clusters = -1; /* Don't know yet */ 1702 sbi->free_clus_valid = 0; 1703 sbi->prev_free = FAT_START_ENT; 1704 sb->s_maxbytes = 0xffffffff; 1705 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1706 sb->s_time_min = ts.tv_sec; 1707 1708 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1709 cpu_to_le16(FAT_DATE_MAX), 0); 1710 sb->s_time_max = ts.tv_sec; 1711 1712 if (!sbi->fat_length && bpb.fat32_length) { 1713 struct fat_boot_fsinfo *fsinfo; 1714 struct buffer_head *fsinfo_bh; 1715 1716 /* Must be FAT32 */ 1717 sbi->fat_bits = 32; 1718 sbi->fat_length = bpb.fat32_length; 1719 sbi->root_cluster = bpb.fat32_root_cluster; 1720 1721 /* MC - if info_sector is 0, don't multiply by 0 */ 1722 sbi->fsinfo_sector = bpb.fat32_info_sector; 1723 if (sbi->fsinfo_sector == 0) 1724 sbi->fsinfo_sector = 1; 1725 1726 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1727 if (fsinfo_bh == NULL) { 1728 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1729 " (sector = %lu)", sbi->fsinfo_sector); 1730 goto out_fail; 1731 } 1732 1733 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1734 if (!IS_FSINFO(fsinfo)) { 1735 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1736 "0x%08x, 0x%08x (sector = %lu)", 1737 le32_to_cpu(fsinfo->signature1), 1738 le32_to_cpu(fsinfo->signature2), 1739 sbi->fsinfo_sector); 1740 } else { 1741 if (sbi->options.usefree) 1742 sbi->free_clus_valid = 1; 1743 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1744 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1745 } 1746 1747 brelse(fsinfo_bh); 1748 } 1749 1750 /* interpret volume ID as a little endian 32 bit integer */ 1751 if (is_fat32(sbi)) 1752 sbi->vol_id = bpb.fat32_vol_id; 1753 else /* fat 16 or 12 */ 1754 sbi->vol_id = bpb.fat16_vol_id; 1755 1756 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1757 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1758 1759 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1760 sbi->dir_entries = bpb.fat_dir_entries; 1761 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1762 if (!silent) 1763 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1764 " (%u)", sbi->dir_entries); 1765 goto out_invalid; 1766 } 1767 1768 rootdir_sectors = sbi->dir_entries 1769 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1770 sbi->data_start = sbi->dir_start + rootdir_sectors; 1771 total_sectors = bpb.fat_sectors; 1772 if (total_sectors == 0) 1773 total_sectors = bpb.fat_total_sect; 1774 1775 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1776 1777 if (!is_fat32(sbi)) 1778 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1779 1780 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1781 if (is_fat32(sbi)) 1782 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1783 else /* fat 16 or 12 */ 1784 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1785 1786 /* check that FAT table does not overflow */ 1787 fat_clusters = calc_fat_clusters(sb); 1788 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1789 if (total_clusters > max_fat(sb)) { 1790 if (!silent) 1791 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1792 total_clusters); 1793 goto out_invalid; 1794 } 1795 1796 sbi->max_cluster = total_clusters + FAT_START_ENT; 1797 /* check the free_clusters, it's not necessarily correct */ 1798 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1799 sbi->free_clusters = -1; 1800 /* check the prev_free, it's not necessarily correct */ 1801 sbi->prev_free %= sbi->max_cluster; 1802 if (sbi->prev_free < FAT_START_ENT) 1803 sbi->prev_free = FAT_START_ENT; 1804 1805 /* set up enough so that it can read an inode */ 1806 fat_hash_init(sb); 1807 dir_hash_init(sb); 1808 fat_ent_access_init(sb); 1809 1810 /* 1811 * The low byte of the first FAT entry must have the same value as 1812 * the media field of the boot sector. But in real world, too many 1813 * devices are writing wrong values. So, removed that validity check. 1814 * 1815 * The removed check compared the first FAT entry to a value dependent 1816 * on the media field like this: 1817 * == (0x0F00 | media), for FAT12 1818 * == (0XFF00 | media), for FAT16 1819 * == (0x0FFFFF | media), for FAT32 1820 */ 1821 1822 error = -EINVAL; 1823 sprintf(buf, "cp%d", sbi->options.codepage); 1824 sbi->nls_disk = load_nls(buf); 1825 if (!sbi->nls_disk) { 1826 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1827 goto out_fail; 1828 } 1829 1830 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1831 if (sbi->options.isvfat) { 1832 sbi->nls_io = load_nls(sbi->options.iocharset); 1833 if (!sbi->nls_io) { 1834 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1835 sbi->options.iocharset); 1836 goto out_fail; 1837 } 1838 } 1839 1840 error = -ENOMEM; 1841 fat_inode = new_inode(sb); 1842 if (!fat_inode) 1843 goto out_fail; 1844 sbi->fat_inode = fat_inode; 1845 1846 fsinfo_inode = new_inode(sb); 1847 if (!fsinfo_inode) 1848 goto out_fail; 1849 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1850 sbi->fsinfo_inode = fsinfo_inode; 1851 insert_inode_hash(fsinfo_inode); 1852 1853 root_inode = new_inode(sb); 1854 if (!root_inode) 1855 goto out_fail; 1856 root_inode->i_ino = MSDOS_ROOT_INO; 1857 inode_set_iversion(root_inode, 1); 1858 error = fat_read_root(root_inode); 1859 if (error < 0) { 1860 iput(root_inode); 1861 goto out_fail; 1862 } 1863 error = -ENOMEM; 1864 insert_inode_hash(root_inode); 1865 fat_attach(root_inode, 0); 1866 sb->s_root = d_make_root(root_inode); 1867 if (!sb->s_root) { 1868 fat_msg(sb, KERN_ERR, "get root inode failed"); 1869 goto out_fail; 1870 } 1871 1872 if (sbi->options.discard) { 1873 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1874 if (!blk_queue_discard(q)) 1875 fat_msg(sb, KERN_WARNING, 1876 "mounting with \"discard\" option, but " 1877 "the device does not support discard"); 1878 } 1879 1880 fat_set_state(sb, 1, 0); 1881 return 0; 1882 1883 out_invalid: 1884 error = -EINVAL; 1885 if (!silent) 1886 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1887 1888 out_fail: 1889 if (fsinfo_inode) 1890 iput(fsinfo_inode); 1891 if (fat_inode) 1892 iput(fat_inode); 1893 unload_nls(sbi->nls_io); 1894 unload_nls(sbi->nls_disk); 1895 fat_reset_iocharset(&sbi->options); 1896 sb->s_fs_info = NULL; 1897 kfree(sbi); 1898 return error; 1899 } 1900 1901 EXPORT_SYMBOL_GPL(fat_fill_super); 1902 1903 /* 1904 * helper function for fat_flush_inodes. This writes both the inode 1905 * and the file data blocks, waiting for in flight data blocks before 1906 * the start of the call. It does not wait for any io started 1907 * during the call 1908 */ 1909 static int writeback_inode(struct inode *inode) 1910 { 1911 1912 int ret; 1913 1914 /* if we used wait=1, sync_inode_metadata waits for the io for the 1915 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1916 * and filemap_fdatawrite is used for the data blocks 1917 */ 1918 ret = sync_inode_metadata(inode, 0); 1919 if (!ret) 1920 ret = filemap_fdatawrite(inode->i_mapping); 1921 return ret; 1922 } 1923 1924 /* 1925 * write data and metadata corresponding to i1 and i2. The io is 1926 * started but we do not wait for any of it to finish. 1927 * 1928 * filemap_flush is used for the block device, so if there is a dirty 1929 * page for a block already in flight, we will not wait and start the 1930 * io over again 1931 */ 1932 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1933 { 1934 int ret = 0; 1935 if (!MSDOS_SB(sb)->options.flush) 1936 return 0; 1937 if (i1) 1938 ret = writeback_inode(i1); 1939 if (!ret && i2) 1940 ret = writeback_inode(i2); 1941 if (!ret) { 1942 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1943 ret = filemap_flush(mapping); 1944 } 1945 return ret; 1946 } 1947 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1948 1949 static int __init init_fat_fs(void) 1950 { 1951 int err; 1952 1953 err = fat_cache_init(); 1954 if (err) 1955 return err; 1956 1957 err = fat_init_inodecache(); 1958 if (err) 1959 goto failed; 1960 1961 return 0; 1962 1963 failed: 1964 fat_cache_destroy(); 1965 return err; 1966 } 1967 1968 static void __exit exit_fat_fs(void) 1969 { 1970 fat_cache_destroy(); 1971 fat_destroy_inodecache(); 1972 } 1973 1974 module_init(init_fat_fs) 1975 module_exit(exit_fat_fs) 1976 1977 MODULE_LICENSE("GPL"); 1978