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 */ 44struct 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 64static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 65static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 66 67static 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 104int 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 119static 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 183static 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 197static int fat_writepages(struct address_space *mapping, 198 struct writeback_control *wbc) 199{ 200 return mpage_writepages(mapping, wbc, fat_get_block); 201} 202 203static int fat_read_folio(struct file *file, struct folio *folio) 204{ 205 return mpage_read_folio(folio, fat_get_block); 206} 207 208static void fat_readahead(struct readahead_control *rac) 209{ 210 mpage_readahead(rac, fat_get_block); 211} 212 213static void fat_write_failed(struct address_space *mapping, loff_t to) 214{ 215 struct inode *inode = mapping->host; 216 217 if (to > inode->i_size) { 218 truncate_pagecache(inode, inode->i_size); 219 fat_truncate_blocks(inode, inode->i_size); 220 } 221} 222 223static int fat_write_begin(struct file *file, struct address_space *mapping, 224 loff_t pos, unsigned len, 225 struct page **pagep, void **fsdata) 226{ 227 int err; 228 229 *pagep = NULL; 230 err = cont_write_begin(file, mapping, pos, len, 231 pagep, fsdata, fat_get_block, 232 &MSDOS_I(mapping->host)->mmu_private); 233 if (err < 0) 234 fat_write_failed(mapping, pos + len); 235 return err; 236} 237 238static int fat_write_end(struct file *file, struct address_space *mapping, 239 loff_t pos, unsigned len, unsigned copied, 240 struct page *pagep, void *fsdata) 241{ 242 struct inode *inode = mapping->host; 243 int err; 244 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 245 if (err < len) 246 fat_write_failed(mapping, pos + len); 247 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 248 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 249 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 250 mark_inode_dirty(inode); 251 } 252 return err; 253} 254 255static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 256{ 257 struct file *file = iocb->ki_filp; 258 struct address_space *mapping = file->f_mapping; 259 struct inode *inode = mapping->host; 260 size_t count = iov_iter_count(iter); 261 loff_t offset = iocb->ki_pos; 262 ssize_t ret; 263 264 if (iov_iter_rw(iter) == WRITE) { 265 /* 266 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 267 * so we need to update the ->mmu_private to block boundary. 268 * 269 * But we must fill the remaining area or hole by nul for 270 * updating ->mmu_private. 271 * 272 * Return 0, and fallback to normal buffered write. 273 */ 274 loff_t size = offset + count; 275 if (MSDOS_I(inode)->mmu_private < size) 276 return 0; 277 } 278 279 /* 280 * FAT need to use the DIO_LOCKING for avoiding the race 281 * condition of fat_get_block() and ->truncate(). 282 */ 283 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 284 if (ret < 0 && iov_iter_rw(iter) == WRITE) 285 fat_write_failed(mapping, offset + count); 286 287 return ret; 288} 289 290static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 291 struct buffer_head *bh_result, int create) 292{ 293 struct super_block *sb = inode->i_sb; 294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 295 int err; 296 sector_t bmap; 297 unsigned long mapped_blocks; 298 299 BUG_ON(create != 0); 300 301 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 302 if (err) 303 return err; 304 305 if (bmap) { 306 map_bh(bh_result, sb, bmap); 307 max_blocks = min(mapped_blocks, max_blocks); 308 } 309 310 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 311 312 return 0; 313} 314 315static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 316{ 317 sector_t blocknr; 318 319 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 320 down_read(&MSDOS_I(mapping->host)->truncate_lock); 321 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 322 up_read(&MSDOS_I(mapping->host)->truncate_lock); 323 324 return blocknr; 325} 326 327/* 328 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 329 * up to the end of the block which corresponds to `from'. 330 * This is required during truncate to physically zeroout the tail end 331 * of that block so it doesn't yield old data if the file is later grown. 332 * Also, avoid causing failure from fsx for cases of "data past EOF" 333 */ 334int fat_block_truncate_page(struct inode *inode, loff_t from) 335{ 336 return block_truncate_page(inode->i_mapping, from, fat_get_block); 337} 338 339static const struct address_space_operations fat_aops = { 340 .dirty_folio = block_dirty_folio, 341 .invalidate_folio = block_invalidate_folio, 342 .read_folio = fat_read_folio, 343 .readahead = fat_readahead, 344 .writepages = fat_writepages, 345 .write_begin = fat_write_begin, 346 .write_end = fat_write_end, 347 .direct_IO = fat_direct_IO, 348 .bmap = _fat_bmap, 349 .migrate_folio = buffer_migrate_folio, 350}; 351 352/* 353 * New FAT inode stuff. We do the following: 354 * a) i_ino is constant and has nothing with on-disk location. 355 * b) FAT manages its own cache of directory entries. 356 * c) *This* cache is indexed by on-disk location. 357 * d) inode has an associated directory entry, all right, but 358 * it may be unhashed. 359 * e) currently entries are stored within struct inode. That should 360 * change. 361 * f) we deal with races in the following way: 362 * 1. readdir() and lookup() do FAT-dir-cache lookup. 363 * 2. rename() unhashes the F-d-c entry and rehashes it in 364 * a new place. 365 * 3. unlink() and rmdir() unhash F-d-c entry. 366 * 4. fat_write_inode() checks whether the thing is unhashed. 367 * If it is we silently return. If it isn't we do bread(), 368 * check if the location is still valid and retry if it 369 * isn't. Otherwise we do changes. 370 * 5. Spinlock is used to protect hash/unhash/location check/lookup 371 * 6. fat_evict_inode() unhashes the F-d-c entry. 372 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 373 * and consider negative result as cache miss. 374 */ 375 376static void fat_hash_init(struct super_block *sb) 377{ 378 struct msdos_sb_info *sbi = MSDOS_SB(sb); 379 int i; 380 381 spin_lock_init(&sbi->inode_hash_lock); 382 for (i = 0; i < FAT_HASH_SIZE; i++) 383 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 384} 385 386static inline unsigned long fat_hash(loff_t i_pos) 387{ 388 return hash_32(i_pos, FAT_HASH_BITS); 389} 390 391static void dir_hash_init(struct super_block *sb) 392{ 393 struct msdos_sb_info *sbi = MSDOS_SB(sb); 394 int i; 395 396 spin_lock_init(&sbi->dir_hash_lock); 397 for (i = 0; i < FAT_HASH_SIZE; i++) 398 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 399} 400 401void fat_attach(struct inode *inode, loff_t i_pos) 402{ 403 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 404 405 if (inode->i_ino != MSDOS_ROOT_INO) { 406 struct hlist_head *head = sbi->inode_hashtable 407 + fat_hash(i_pos); 408 409 spin_lock(&sbi->inode_hash_lock); 410 MSDOS_I(inode)->i_pos = i_pos; 411 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 412 spin_unlock(&sbi->inode_hash_lock); 413 } 414 415 /* If NFS support is enabled, cache the mapping of start cluster 416 * to directory inode. This is used during reconnection of 417 * dentries to the filesystem root. 418 */ 419 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 420 struct hlist_head *d_head = sbi->dir_hashtable; 421 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 422 423 spin_lock(&sbi->dir_hash_lock); 424 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 425 spin_unlock(&sbi->dir_hash_lock); 426 } 427} 428EXPORT_SYMBOL_GPL(fat_attach); 429 430void fat_detach(struct inode *inode) 431{ 432 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 433 spin_lock(&sbi->inode_hash_lock); 434 MSDOS_I(inode)->i_pos = 0; 435 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 436 spin_unlock(&sbi->inode_hash_lock); 437 438 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 439 spin_lock(&sbi->dir_hash_lock); 440 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 441 spin_unlock(&sbi->dir_hash_lock); 442 } 443} 444EXPORT_SYMBOL_GPL(fat_detach); 445 446struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 447{ 448 struct msdos_sb_info *sbi = MSDOS_SB(sb); 449 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 450 struct msdos_inode_info *i; 451 struct inode *inode = NULL; 452 453 spin_lock(&sbi->inode_hash_lock); 454 hlist_for_each_entry(i, head, i_fat_hash) { 455 BUG_ON(i->vfs_inode.i_sb != sb); 456 if (i->i_pos != i_pos) 457 continue; 458 inode = igrab(&i->vfs_inode); 459 if (inode) 460 break; 461 } 462 spin_unlock(&sbi->inode_hash_lock); 463 return inode; 464} 465 466static int is_exec(unsigned char *extension) 467{ 468 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 469 470 for (walk = exe_extensions; *walk; walk += 3) 471 if (!strncmp(extension, walk, 3)) 472 return 1; 473 return 0; 474} 475 476static int fat_calc_dir_size(struct inode *inode) 477{ 478 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 479 int ret, fclus, dclus; 480 481 inode->i_size = 0; 482 if (MSDOS_I(inode)->i_start == 0) 483 return 0; 484 485 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 486 if (ret < 0) 487 return ret; 488 inode->i_size = (fclus + 1) << sbi->cluster_bits; 489 490 return 0; 491} 492 493static int fat_validate_dir(struct inode *dir) 494{ 495 struct super_block *sb = dir->i_sb; 496 497 if (dir->i_nlink < 2) { 498 /* Directory should have "."/".." entries at least. */ 499 fat_fs_error(sb, "corrupted directory (invalid entries)"); 500 return -EIO; 501 } 502 if (MSDOS_I(dir)->i_start == 0 || 503 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 504 /* Directory should point valid cluster. */ 505 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 506 return -EIO; 507 } 508 return 0; 509} 510 511/* doesn't deal with root inode */ 512int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 513{ 514 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 515 struct timespec64 mtime; 516 int error; 517 518 MSDOS_I(inode)->i_pos = 0; 519 inode->i_uid = sbi->options.fs_uid; 520 inode->i_gid = sbi->options.fs_gid; 521 inode_inc_iversion(inode); 522 inode->i_generation = get_random_u32(); 523 524 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 525 inode->i_generation &= ~1; 526 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 527 inode->i_op = sbi->dir_ops; 528 inode->i_fop = &fat_dir_operations; 529 530 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 531 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 532 error = fat_calc_dir_size(inode); 533 if (error < 0) 534 return error; 535 MSDOS_I(inode)->mmu_private = inode->i_size; 536 537 set_nlink(inode, fat_subdirs(inode)); 538 539 error = fat_validate_dir(inode); 540 if (error < 0) 541 return error; 542 } else { /* not a directory */ 543 inode->i_generation |= 1; 544 inode->i_mode = fat_make_mode(sbi, de->attr, 545 ((sbi->options.showexec && !is_exec(de->name + 8)) 546 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 547 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 548 549 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 550 inode->i_size = le32_to_cpu(de->size); 551 inode->i_op = &fat_file_inode_operations; 552 inode->i_fop = &fat_file_operations; 553 inode->i_mapping->a_ops = &fat_aops; 554 MSDOS_I(inode)->mmu_private = inode->i_size; 555 } 556 if (de->attr & ATTR_SYS) { 557 if (sbi->options.sys_immutable) 558 inode->i_flags |= S_IMMUTABLE; 559 } 560 fat_save_attrs(inode, de->attr); 561 562 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 563 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 564 565 fat_time_fat2unix(sbi, &mtime, de->time, de->date, 0); 566 inode_set_mtime_to_ts(inode, mtime); 567 inode_set_ctime_to_ts(inode, mtime); 568 if (sbi->options.isvfat) { 569 struct timespec64 atime; 570 571 fat_time_fat2unix(sbi, &atime, 0, de->adate, 0); 572 inode_set_atime_to_ts(inode, atime); 573 fat_time_fat2unix(sbi, &MSDOS_I(inode)->i_crtime, de->ctime, 574 de->cdate, de->ctime_cs); 575 } else 576 inode_set_atime_to_ts(inode, fat_truncate_atime(sbi, &mtime)); 577 578 return 0; 579} 580 581static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 582{ 583 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 584 mutex_lock(&sbi->nfs_build_inode_lock); 585} 586 587static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 588{ 589 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 590 mutex_unlock(&sbi->nfs_build_inode_lock); 591} 592 593struct inode *fat_build_inode(struct super_block *sb, 594 struct msdos_dir_entry *de, loff_t i_pos) 595{ 596 struct inode *inode; 597 int err; 598 599 fat_lock_build_inode(MSDOS_SB(sb)); 600 inode = fat_iget(sb, i_pos); 601 if (inode) 602 goto out; 603 inode = new_inode(sb); 604 if (!inode) { 605 inode = ERR_PTR(-ENOMEM); 606 goto out; 607 } 608 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 609 inode_set_iversion(inode, 1); 610 err = fat_fill_inode(inode, de); 611 if (err) { 612 iput(inode); 613 inode = ERR_PTR(err); 614 goto out; 615 } 616 fat_attach(inode, i_pos); 617 insert_inode_hash(inode); 618out: 619 fat_unlock_build_inode(MSDOS_SB(sb)); 620 return inode; 621} 622 623EXPORT_SYMBOL_GPL(fat_build_inode); 624 625static int __fat_write_inode(struct inode *inode, int wait); 626 627static void fat_free_eofblocks(struct inode *inode) 628{ 629 /* Release unwritten fallocated blocks on inode eviction. */ 630 if ((inode->i_blocks << 9) > 631 round_up(MSDOS_I(inode)->mmu_private, 632 MSDOS_SB(inode->i_sb)->cluster_size)) { 633 int err; 634 635 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 636 /* Fallocate results in updating the i_start/iogstart 637 * for the zero byte file. So, make it return to 638 * original state during evict and commit it to avoid 639 * any corruption on the next access to the cluster 640 * chain for the file. 641 */ 642 err = __fat_write_inode(inode, inode_needs_sync(inode)); 643 if (err) { 644 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 645 "update on disk inode for unused " 646 "fallocated blocks, inode could be " 647 "corrupted. Please run fsck"); 648 } 649 650 } 651} 652 653static void fat_evict_inode(struct inode *inode) 654{ 655 truncate_inode_pages_final(&inode->i_data); 656 if (!inode->i_nlink) { 657 inode->i_size = 0; 658 fat_truncate_blocks(inode, 0); 659 } else 660 fat_free_eofblocks(inode); 661 662 invalidate_inode_buffers(inode); 663 clear_inode(inode); 664 fat_cache_inval_inode(inode); 665 fat_detach(inode); 666} 667 668static void fat_set_state(struct super_block *sb, 669 unsigned int set, unsigned int force) 670{ 671 struct buffer_head *bh; 672 struct fat_boot_sector *b; 673 struct msdos_sb_info *sbi = MSDOS_SB(sb); 674 675 /* do not change any thing if mounted read only */ 676 if (sb_rdonly(sb) && !force) 677 return; 678 679 /* do not change state if fs was dirty */ 680 if (sbi->dirty) { 681 /* warn only on set (mount). */ 682 if (set) 683 fat_msg(sb, KERN_WARNING, "Volume was not properly " 684 "unmounted. Some data may be corrupt. " 685 "Please run fsck."); 686 return; 687 } 688 689 bh = sb_bread(sb, 0); 690 if (bh == NULL) { 691 fat_msg(sb, KERN_ERR, "unable to read boot sector " 692 "to mark fs as dirty"); 693 return; 694 } 695 696 b = (struct fat_boot_sector *) bh->b_data; 697 698 if (is_fat32(sbi)) { 699 if (set) 700 b->fat32.state |= FAT_STATE_DIRTY; 701 else 702 b->fat32.state &= ~FAT_STATE_DIRTY; 703 } else /* fat 16 and 12 */ { 704 if (set) 705 b->fat16.state |= FAT_STATE_DIRTY; 706 else 707 b->fat16.state &= ~FAT_STATE_DIRTY; 708 } 709 710 mark_buffer_dirty(bh); 711 sync_dirty_buffer(bh); 712 brelse(bh); 713} 714 715static void fat_reset_iocharset(struct fat_mount_options *opts) 716{ 717 if (opts->iocharset != fat_default_iocharset) { 718 /* Note: opts->iocharset can be NULL here */ 719 kfree(opts->iocharset); 720 opts->iocharset = fat_default_iocharset; 721 } 722} 723 724static void delayed_free(struct rcu_head *p) 725{ 726 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 727 unload_nls(sbi->nls_disk); 728 unload_nls(sbi->nls_io); 729 fat_reset_iocharset(&sbi->options); 730 kfree(sbi); 731} 732 733static void fat_put_super(struct super_block *sb) 734{ 735 struct msdos_sb_info *sbi = MSDOS_SB(sb); 736 737 fat_set_state(sb, 0, 0); 738 739 iput(sbi->fsinfo_inode); 740 iput(sbi->fat_inode); 741 742 call_rcu(&sbi->rcu, delayed_free); 743} 744 745static struct kmem_cache *fat_inode_cachep; 746 747static struct inode *fat_alloc_inode(struct super_block *sb) 748{ 749 struct msdos_inode_info *ei; 750 ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS); 751 if (!ei) 752 return NULL; 753 754 init_rwsem(&ei->truncate_lock); 755 /* Zeroing to allow iput() even if partial initialized inode. */ 756 ei->mmu_private = 0; 757 ei->i_start = 0; 758 ei->i_logstart = 0; 759 ei->i_attrs = 0; 760 ei->i_pos = 0; 761 ei->i_crtime.tv_sec = 0; 762 ei->i_crtime.tv_nsec = 0; 763 764 return &ei->vfs_inode; 765} 766 767static void fat_free_inode(struct inode *inode) 768{ 769 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 770} 771 772static void init_once(void *foo) 773{ 774 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 775 776 spin_lock_init(&ei->cache_lru_lock); 777 ei->nr_caches = 0; 778 ei->cache_valid_id = FAT_CACHE_VALID + 1; 779 INIT_LIST_HEAD(&ei->cache_lru); 780 INIT_HLIST_NODE(&ei->i_fat_hash); 781 INIT_HLIST_NODE(&ei->i_dir_hash); 782 inode_init_once(&ei->vfs_inode); 783} 784 785static int __init fat_init_inodecache(void) 786{ 787 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 788 sizeof(struct msdos_inode_info), 789 0, (SLAB_RECLAIM_ACCOUNT| 790 SLAB_ACCOUNT), 791 init_once); 792 if (fat_inode_cachep == NULL) 793 return -ENOMEM; 794 return 0; 795} 796 797static void __exit fat_destroy_inodecache(void) 798{ 799 /* 800 * Make sure all delayed rcu free inodes are flushed before we 801 * destroy cache. 802 */ 803 rcu_barrier(); 804 kmem_cache_destroy(fat_inode_cachep); 805} 806 807static int fat_remount(struct super_block *sb, int *flags, char *data) 808{ 809 bool new_rdonly; 810 struct msdos_sb_info *sbi = MSDOS_SB(sb); 811 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 812 813 sync_filesystem(sb); 814 815 /* make sure we update state on remount. */ 816 new_rdonly = *flags & SB_RDONLY; 817 if (new_rdonly != sb_rdonly(sb)) { 818 if (new_rdonly) 819 fat_set_state(sb, 0, 0); 820 else 821 fat_set_state(sb, 1, 1); 822 } 823 return 0; 824} 825 826static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 827{ 828 struct super_block *sb = dentry->d_sb; 829 struct msdos_sb_info *sbi = MSDOS_SB(sb); 830 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 831 832 /* If the count of free cluster is still unknown, counts it here. */ 833 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 834 int err = fat_count_free_clusters(dentry->d_sb); 835 if (err) 836 return err; 837 } 838 839 buf->f_type = dentry->d_sb->s_magic; 840 buf->f_bsize = sbi->cluster_size; 841 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 842 buf->f_bfree = sbi->free_clusters; 843 buf->f_bavail = sbi->free_clusters; 844 buf->f_fsid = u64_to_fsid(id); 845 buf->f_namelen = 846 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 847 848 return 0; 849} 850 851static int __fat_write_inode(struct inode *inode, int wait) 852{ 853 struct super_block *sb = inode->i_sb; 854 struct msdos_sb_info *sbi = MSDOS_SB(sb); 855 struct buffer_head *bh; 856 struct msdos_dir_entry *raw_entry; 857 struct timespec64 mtime; 858 loff_t i_pos; 859 sector_t blocknr; 860 int err, offset; 861 862 if (inode->i_ino == MSDOS_ROOT_INO) 863 return 0; 864 865retry: 866 i_pos = fat_i_pos_read(sbi, inode); 867 if (!i_pos) 868 return 0; 869 870 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 871 bh = sb_bread(sb, blocknr); 872 if (!bh) { 873 fat_msg(sb, KERN_ERR, "unable to read inode block " 874 "for updating (i_pos %lld)", i_pos); 875 return -EIO; 876 } 877 spin_lock(&sbi->inode_hash_lock); 878 if (i_pos != MSDOS_I(inode)->i_pos) { 879 spin_unlock(&sbi->inode_hash_lock); 880 brelse(bh); 881 goto retry; 882 } 883 884 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 885 if (S_ISDIR(inode->i_mode)) 886 raw_entry->size = 0; 887 else 888 raw_entry->size = cpu_to_le32(inode->i_size); 889 raw_entry->attr = fat_make_attrs(inode); 890 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 891 mtime = inode_get_mtime(inode); 892 fat_time_unix2fat(sbi, &mtime, &raw_entry->time, 893 &raw_entry->date, NULL); 894 if (sbi->options.isvfat) { 895 struct timespec64 ts = inode_get_atime(inode); 896 __le16 atime; 897 898 fat_time_unix2fat(sbi, &ts, &atime, &raw_entry->adate, NULL); 899 fat_time_unix2fat(sbi, &MSDOS_I(inode)->i_crtime, &raw_entry->ctime, 900 &raw_entry->cdate, &raw_entry->ctime_cs); 901 } 902 spin_unlock(&sbi->inode_hash_lock); 903 mark_buffer_dirty(bh); 904 err = 0; 905 if (wait) 906 err = sync_dirty_buffer(bh); 907 brelse(bh); 908 return err; 909} 910 911static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 912{ 913 int err; 914 915 if (inode->i_ino == MSDOS_FSINFO_INO) { 916 struct super_block *sb = inode->i_sb; 917 918 mutex_lock(&MSDOS_SB(sb)->s_lock); 919 err = fat_clusters_flush(sb); 920 mutex_unlock(&MSDOS_SB(sb)->s_lock); 921 } else 922 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 923 924 return err; 925} 926 927int fat_sync_inode(struct inode *inode) 928{ 929 return __fat_write_inode(inode, 1); 930} 931 932EXPORT_SYMBOL_GPL(fat_sync_inode); 933 934static int fat_show_options(struct seq_file *m, struct dentry *root); 935static const struct super_operations fat_sops = { 936 .alloc_inode = fat_alloc_inode, 937 .free_inode = fat_free_inode, 938 .write_inode = fat_write_inode, 939 .evict_inode = fat_evict_inode, 940 .put_super = fat_put_super, 941 .statfs = fat_statfs, 942 .remount_fs = fat_remount, 943 944 .show_options = fat_show_options, 945}; 946 947static int fat_show_options(struct seq_file *m, struct dentry *root) 948{ 949 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 950 struct fat_mount_options *opts = &sbi->options; 951 int isvfat = opts->isvfat; 952 953 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 954 seq_printf(m, ",uid=%u", 955 from_kuid_munged(&init_user_ns, opts->fs_uid)); 956 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 957 seq_printf(m, ",gid=%u", 958 from_kgid_munged(&init_user_ns, opts->fs_gid)); 959 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 960 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 961 if (opts->allow_utime) 962 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 963 if (sbi->nls_disk) 964 /* strip "cp" prefix from displayed option */ 965 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 966 if (isvfat) { 967 if (sbi->nls_io) 968 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 969 970 switch (opts->shortname) { 971 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 972 seq_puts(m, ",shortname=win95"); 973 break; 974 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 975 seq_puts(m, ",shortname=winnt"); 976 break; 977 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 978 seq_puts(m, ",shortname=mixed"); 979 break; 980 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 981 seq_puts(m, ",shortname=lower"); 982 break; 983 default: 984 seq_puts(m, ",shortname=unknown"); 985 break; 986 } 987 } 988 if (opts->name_check != 'n') 989 seq_printf(m, ",check=%c", opts->name_check); 990 if (opts->usefree) 991 seq_puts(m, ",usefree"); 992 if (opts->quiet) 993 seq_puts(m, ",quiet"); 994 if (opts->showexec) 995 seq_puts(m, ",showexec"); 996 if (opts->sys_immutable) 997 seq_puts(m, ",sys_immutable"); 998 if (!isvfat) { 999 if (opts->dotsOK) 1000 seq_puts(m, ",dotsOK=yes"); 1001 if (opts->nocase) 1002 seq_puts(m, ",nocase"); 1003 } else { 1004 if (opts->utf8) 1005 seq_puts(m, ",utf8"); 1006 if (opts->unicode_xlate) 1007 seq_puts(m, ",uni_xlate"); 1008 if (!opts->numtail) 1009 seq_puts(m, ",nonumtail"); 1010 if (opts->rodir) 1011 seq_puts(m, ",rodir"); 1012 } 1013 if (opts->flush) 1014 seq_puts(m, ",flush"); 1015 if (opts->tz_set) { 1016 if (opts->time_offset) 1017 seq_printf(m, ",time_offset=%d", opts->time_offset); 1018 else 1019 seq_puts(m, ",tz=UTC"); 1020 } 1021 if (opts->errors == FAT_ERRORS_CONT) 1022 seq_puts(m, ",errors=continue"); 1023 else if (opts->errors == FAT_ERRORS_PANIC) 1024 seq_puts(m, ",errors=panic"); 1025 else 1026 seq_puts(m, ",errors=remount-ro"); 1027 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1028 seq_puts(m, ",nfs=nostale_ro"); 1029 else if (opts->nfs) 1030 seq_puts(m, ",nfs=stale_rw"); 1031 if (opts->discard) 1032 seq_puts(m, ",discard"); 1033 if (opts->dos1xfloppy) 1034 seq_puts(m, ",dos1xfloppy"); 1035 1036 return 0; 1037} 1038 1039enum { 1040 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1041 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1042 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1043 Opt_immutable, Opt_dots, Opt_nodots, 1044 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1045 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1046 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1047 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1048 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1049 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1050}; 1051 1052static const match_table_t fat_tokens = { 1053 {Opt_check_r, "check=relaxed"}, 1054 {Opt_check_s, "check=strict"}, 1055 {Opt_check_n, "check=normal"}, 1056 {Opt_check_r, "check=r"}, 1057 {Opt_check_s, "check=s"}, 1058 {Opt_check_n, "check=n"}, 1059 {Opt_uid, "uid=%u"}, 1060 {Opt_gid, "gid=%u"}, 1061 {Opt_umask, "umask=%o"}, 1062 {Opt_dmask, "dmask=%o"}, 1063 {Opt_fmask, "fmask=%o"}, 1064 {Opt_allow_utime, "allow_utime=%o"}, 1065 {Opt_codepage, "codepage=%u"}, 1066 {Opt_usefree, "usefree"}, 1067 {Opt_nocase, "nocase"}, 1068 {Opt_quiet, "quiet"}, 1069 {Opt_showexec, "showexec"}, 1070 {Opt_debug, "debug"}, 1071 {Opt_immutable, "sys_immutable"}, 1072 {Opt_flush, "flush"}, 1073 {Opt_tz_utc, "tz=UTC"}, 1074 {Opt_time_offset, "time_offset=%d"}, 1075 {Opt_err_cont, "errors=continue"}, 1076 {Opt_err_panic, "errors=panic"}, 1077 {Opt_err_ro, "errors=remount-ro"}, 1078 {Opt_discard, "discard"}, 1079 {Opt_nfs_stale_rw, "nfs"}, 1080 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1081 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1082 {Opt_dos1xfloppy, "dos1xfloppy"}, 1083 {Opt_obsolete, "conv=binary"}, 1084 {Opt_obsolete, "conv=text"}, 1085 {Opt_obsolete, "conv=auto"}, 1086 {Opt_obsolete, "conv=b"}, 1087 {Opt_obsolete, "conv=t"}, 1088 {Opt_obsolete, "conv=a"}, 1089 {Opt_obsolete, "fat=%u"}, 1090 {Opt_obsolete, "blocksize=%u"}, 1091 {Opt_obsolete, "cvf_format=%20s"}, 1092 {Opt_obsolete, "cvf_options=%100s"}, 1093 {Opt_obsolete, "posix"}, 1094 {Opt_err, NULL}, 1095}; 1096static const match_table_t msdos_tokens = { 1097 {Opt_nodots, "nodots"}, 1098 {Opt_nodots, "dotsOK=no"}, 1099 {Opt_dots, "dots"}, 1100 {Opt_dots, "dotsOK=yes"}, 1101 {Opt_err, NULL} 1102}; 1103static const match_table_t vfat_tokens = { 1104 {Opt_charset, "iocharset=%s"}, 1105 {Opt_shortname_lower, "shortname=lower"}, 1106 {Opt_shortname_win95, "shortname=win95"}, 1107 {Opt_shortname_winnt, "shortname=winnt"}, 1108 {Opt_shortname_mixed, "shortname=mixed"}, 1109 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1110 {Opt_utf8_no, "utf8=no"}, 1111 {Opt_utf8_no, "utf8=false"}, 1112 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1113 {Opt_utf8_yes, "utf8=yes"}, 1114 {Opt_utf8_yes, "utf8=true"}, 1115 {Opt_utf8_yes, "utf8"}, 1116 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1117 {Opt_uni_xl_no, "uni_xlate=no"}, 1118 {Opt_uni_xl_no, "uni_xlate=false"}, 1119 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1120 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1121 {Opt_uni_xl_yes, "uni_xlate=true"}, 1122 {Opt_uni_xl_yes, "uni_xlate"}, 1123 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1124 {Opt_nonumtail_no, "nonumtail=no"}, 1125 {Opt_nonumtail_no, "nonumtail=false"}, 1126 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1127 {Opt_nonumtail_yes, "nonumtail=yes"}, 1128 {Opt_nonumtail_yes, "nonumtail=true"}, 1129 {Opt_nonumtail_yes, "nonumtail"}, 1130 {Opt_rodir, "rodir"}, 1131 {Opt_err, NULL} 1132}; 1133 1134static int parse_options(struct super_block *sb, char *options, int is_vfat, 1135 int silent, int *debug, struct fat_mount_options *opts) 1136{ 1137 char *p; 1138 substring_t args[MAX_OPT_ARGS]; 1139 int option; 1140 char *iocharset; 1141 1142 opts->isvfat = is_vfat; 1143 1144 opts->fs_uid = current_uid(); 1145 opts->fs_gid = current_gid(); 1146 opts->fs_fmask = opts->fs_dmask = current_umask(); 1147 opts->allow_utime = -1; 1148 opts->codepage = fat_default_codepage; 1149 fat_reset_iocharset(opts); 1150 if (is_vfat) { 1151 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1152 opts->rodir = 0; 1153 } else { 1154 opts->shortname = 0; 1155 opts->rodir = 1; 1156 } 1157 opts->name_check = 'n'; 1158 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1159 opts->unicode_xlate = 0; 1160 opts->numtail = 1; 1161 opts->usefree = opts->nocase = 0; 1162 opts->tz_set = 0; 1163 opts->nfs = 0; 1164 opts->errors = FAT_ERRORS_RO; 1165 *debug = 0; 1166 1167 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1168 1169 if (!options) 1170 goto out; 1171 1172 while ((p = strsep(&options, ",")) != NULL) { 1173 int token; 1174 if (!*p) 1175 continue; 1176 1177 token = match_token(p, fat_tokens, args); 1178 if (token == Opt_err) { 1179 if (is_vfat) 1180 token = match_token(p, vfat_tokens, args); 1181 else 1182 token = match_token(p, msdos_tokens, args); 1183 } 1184 switch (token) { 1185 case Opt_check_s: 1186 opts->name_check = 's'; 1187 break; 1188 case Opt_check_r: 1189 opts->name_check = 'r'; 1190 break; 1191 case Opt_check_n: 1192 opts->name_check = 'n'; 1193 break; 1194 case Opt_usefree: 1195 opts->usefree = 1; 1196 break; 1197 case Opt_nocase: 1198 if (!is_vfat) 1199 opts->nocase = 1; 1200 else { 1201 /* for backward compatibility */ 1202 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1203 | VFAT_SFN_CREATE_WIN95; 1204 } 1205 break; 1206 case Opt_quiet: 1207 opts->quiet = 1; 1208 break; 1209 case Opt_showexec: 1210 opts->showexec = 1; 1211 break; 1212 case Opt_debug: 1213 *debug = 1; 1214 break; 1215 case Opt_immutable: 1216 opts->sys_immutable = 1; 1217 break; 1218 case Opt_uid: 1219 if (match_int(&args[0], &option)) 1220 return -EINVAL; 1221 opts->fs_uid = make_kuid(current_user_ns(), option); 1222 if (!uid_valid(opts->fs_uid)) 1223 return -EINVAL; 1224 break; 1225 case Opt_gid: 1226 if (match_int(&args[0], &option)) 1227 return -EINVAL; 1228 opts->fs_gid = make_kgid(current_user_ns(), option); 1229 if (!gid_valid(opts->fs_gid)) 1230 return -EINVAL; 1231 break; 1232 case Opt_umask: 1233 if (match_octal(&args[0], &option)) 1234 return -EINVAL; 1235 opts->fs_fmask = opts->fs_dmask = option; 1236 break; 1237 case Opt_dmask: 1238 if (match_octal(&args[0], &option)) 1239 return -EINVAL; 1240 opts->fs_dmask = option; 1241 break; 1242 case Opt_fmask: 1243 if (match_octal(&args[0], &option)) 1244 return -EINVAL; 1245 opts->fs_fmask = option; 1246 break; 1247 case Opt_allow_utime: 1248 if (match_octal(&args[0], &option)) 1249 return -EINVAL; 1250 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1251 break; 1252 case Opt_codepage: 1253 if (match_int(&args[0], &option)) 1254 return -EINVAL; 1255 opts->codepage = option; 1256 break; 1257 case Opt_flush: 1258 opts->flush = 1; 1259 break; 1260 case Opt_time_offset: 1261 if (match_int(&args[0], &option)) 1262 return -EINVAL; 1263 /* 1264 * GMT+-12 zones may have DST corrections so at least 1265 * 13 hours difference is needed. Make the limit 24 1266 * just in case someone invents something unusual. 1267 */ 1268 if (option < -24 * 60 || option > 24 * 60) 1269 return -EINVAL; 1270 opts->tz_set = 1; 1271 opts->time_offset = option; 1272 break; 1273 case Opt_tz_utc: 1274 opts->tz_set = 1; 1275 opts->time_offset = 0; 1276 break; 1277 case Opt_err_cont: 1278 opts->errors = FAT_ERRORS_CONT; 1279 break; 1280 case Opt_err_panic: 1281 opts->errors = FAT_ERRORS_PANIC; 1282 break; 1283 case Opt_err_ro: 1284 opts->errors = FAT_ERRORS_RO; 1285 break; 1286 case Opt_nfs_stale_rw: 1287 opts->nfs = FAT_NFS_STALE_RW; 1288 break; 1289 case Opt_nfs_nostale_ro: 1290 opts->nfs = FAT_NFS_NOSTALE_RO; 1291 break; 1292 case Opt_dos1xfloppy: 1293 opts->dos1xfloppy = 1; 1294 break; 1295 1296 /* msdos specific */ 1297 case Opt_dots: 1298 opts->dotsOK = 1; 1299 break; 1300 case Opt_nodots: 1301 opts->dotsOK = 0; 1302 break; 1303 1304 /* vfat specific */ 1305 case Opt_charset: 1306 fat_reset_iocharset(opts); 1307 iocharset = match_strdup(&args[0]); 1308 if (!iocharset) 1309 return -ENOMEM; 1310 opts->iocharset = iocharset; 1311 break; 1312 case Opt_shortname_lower: 1313 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1314 | VFAT_SFN_CREATE_WIN95; 1315 break; 1316 case Opt_shortname_win95: 1317 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1318 | VFAT_SFN_CREATE_WIN95; 1319 break; 1320 case Opt_shortname_winnt: 1321 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1322 | VFAT_SFN_CREATE_WINNT; 1323 break; 1324 case Opt_shortname_mixed: 1325 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1326 | VFAT_SFN_CREATE_WIN95; 1327 break; 1328 case Opt_utf8_no: /* 0 or no or false */ 1329 opts->utf8 = 0; 1330 break; 1331 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1332 opts->utf8 = 1; 1333 break; 1334 case Opt_uni_xl_no: /* 0 or no or false */ 1335 opts->unicode_xlate = 0; 1336 break; 1337 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1338 opts->unicode_xlate = 1; 1339 break; 1340 case Opt_nonumtail_no: /* 0 or no or false */ 1341 opts->numtail = 1; /* negated option */ 1342 break; 1343 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1344 opts->numtail = 0; /* negated option */ 1345 break; 1346 case Opt_rodir: 1347 opts->rodir = 1; 1348 break; 1349 case Opt_discard: 1350 opts->discard = 1; 1351 break; 1352 1353 /* obsolete mount options */ 1354 case Opt_obsolete: 1355 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1356 "not supported now", p); 1357 break; 1358 /* unknown option */ 1359 default: 1360 if (!silent) { 1361 fat_msg(sb, KERN_ERR, 1362 "Unrecognized mount option \"%s\" " 1363 "or missing value", p); 1364 } 1365 return -EINVAL; 1366 } 1367 } 1368 1369out: 1370 /* UTF-8 doesn't provide FAT semantics */ 1371 if (!strcmp(opts->iocharset, "utf8")) { 1372 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1373 " for FAT filesystems, filesystem will be " 1374 "case sensitive!"); 1375 } 1376 1377 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1378 if (opts->allow_utime == (unsigned short)-1) 1379 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1380 if (opts->unicode_xlate) 1381 opts->utf8 = 0; 1382 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1383 sb->s_flags |= SB_RDONLY; 1384 sb->s_export_op = &fat_export_ops_nostale; 1385 } 1386 1387 return 0; 1388} 1389 1390static int fat_read_root(struct inode *inode) 1391{ 1392 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1393 int error; 1394 1395 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1396 inode->i_uid = sbi->options.fs_uid; 1397 inode->i_gid = sbi->options.fs_gid; 1398 inode_inc_iversion(inode); 1399 inode->i_generation = 0; 1400 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1401 inode->i_op = sbi->dir_ops; 1402 inode->i_fop = &fat_dir_operations; 1403 if (is_fat32(sbi)) { 1404 MSDOS_I(inode)->i_start = sbi->root_cluster; 1405 error = fat_calc_dir_size(inode); 1406 if (error < 0) 1407 return error; 1408 } else { 1409 MSDOS_I(inode)->i_start = 0; 1410 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1411 } 1412 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1413 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1414 MSDOS_I(inode)->i_logstart = 0; 1415 MSDOS_I(inode)->mmu_private = inode->i_size; 1416 1417 fat_save_attrs(inode, ATTR_DIR); 1418 inode_set_mtime_to_ts(inode, 1419 inode_set_atime_to_ts(inode, inode_set_ctime(inode, 0, 0))); 1420 set_nlink(inode, fat_subdirs(inode)+2); 1421 1422 return 0; 1423} 1424 1425static unsigned long calc_fat_clusters(struct super_block *sb) 1426{ 1427 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1428 1429 /* Divide first to avoid overflow */ 1430 if (!is_fat12(sbi)) { 1431 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1432 return ent_per_sec * sbi->fat_length; 1433 } 1434 1435 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1436} 1437 1438static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1439{ 1440 if (get_unaligned_le16(&b->sector_size)) 1441 return false; 1442 if (b->sec_per_clus) 1443 return false; 1444 if (b->reserved) 1445 return false; 1446 if (b->fats) 1447 return false; 1448 if (get_unaligned_le16(&b->dir_entries)) 1449 return false; 1450 if (get_unaligned_le16(&b->sectors)) 1451 return false; 1452 if (b->media) 1453 return false; 1454 if (b->fat_length) 1455 return false; 1456 if (b->secs_track) 1457 return false; 1458 if (b->heads) 1459 return false; 1460 return true; 1461} 1462 1463static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1464 int silent, struct fat_bios_param_block *bpb) 1465{ 1466 int error = -EINVAL; 1467 1468 /* Read in BPB ... */ 1469 memset(bpb, 0, sizeof(*bpb)); 1470 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1471 bpb->fat_sec_per_clus = b->sec_per_clus; 1472 bpb->fat_reserved = le16_to_cpu(b->reserved); 1473 bpb->fat_fats = b->fats; 1474 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1475 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1476 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1477 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1478 1479 bpb->fat16_state = b->fat16.state; 1480 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1481 1482 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1483 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1484 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1485 bpb->fat32_state = b->fat32.state; 1486 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1487 1488 /* Validate this looks like a FAT filesystem BPB */ 1489 if (!bpb->fat_reserved) { 1490 if (!silent) 1491 fat_msg(sb, KERN_ERR, 1492 "bogus number of reserved sectors"); 1493 goto out; 1494 } 1495 if (!bpb->fat_fats) { 1496 if (!silent) 1497 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1498 goto out; 1499 } 1500 1501 /* 1502 * Earlier we checked here that b->secs_track and b->head are nonzero, 1503 * but it turns out valid FAT filesystems can have zero there. 1504 */ 1505 1506 if (!fat_valid_media(b->media)) { 1507 if (!silent) 1508 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1509 (unsigned)b->media); 1510 goto out; 1511 } 1512 1513 if (!is_power_of_2(bpb->fat_sector_size) 1514 || (bpb->fat_sector_size < 512) 1515 || (bpb->fat_sector_size > 4096)) { 1516 if (!silent) 1517 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1518 (unsigned)bpb->fat_sector_size); 1519 goto out; 1520 } 1521 1522 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1523 if (!silent) 1524 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1525 (unsigned)bpb->fat_sec_per_clus); 1526 goto out; 1527 } 1528 1529 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1530 if (!silent) 1531 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1532 goto out; 1533 } 1534 1535 error = 0; 1536 1537out: 1538 return error; 1539} 1540 1541static int fat_read_static_bpb(struct super_block *sb, 1542 struct fat_boot_sector *b, int silent, 1543 struct fat_bios_param_block *bpb) 1544{ 1545 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1546 sector_t bd_sects = bdev_nr_sectors(sb->s_bdev); 1547 struct fat_floppy_defaults *fdefaults = NULL; 1548 int error = -EINVAL; 1549 unsigned i; 1550 1551 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1552 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1553 if (!silent) 1554 fat_msg(sb, KERN_ERR, 1555 "%s; no bootstrapping code", notdos1x); 1556 goto out; 1557 } 1558 1559 /* 1560 * If any value in this region is non-zero, it isn't archaic 1561 * DOS. 1562 */ 1563 if (!fat_bpb_is_zero(b)) { 1564 if (!silent) 1565 fat_msg(sb, KERN_ERR, 1566 "%s; DOS 2.x BPB is non-zero", notdos1x); 1567 goto out; 1568 } 1569 1570 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1571 if (floppy_defaults[i].nr_sectors == bd_sects) { 1572 fdefaults = &floppy_defaults[i]; 1573 break; 1574 } 1575 } 1576 1577 if (fdefaults == NULL) { 1578 if (!silent) 1579 fat_msg(sb, KERN_WARNING, 1580 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1581 (u64)bd_sects); 1582 goto out; 1583 } 1584 1585 if (!silent) 1586 fat_msg(sb, KERN_INFO, 1587 "This looks like a DOS 1.x volume; assuming default BPB values"); 1588 1589 memset(bpb, 0, sizeof(*bpb)); 1590 bpb->fat_sector_size = SECTOR_SIZE; 1591 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1592 bpb->fat_reserved = 1; 1593 bpb->fat_fats = 2; 1594 bpb->fat_dir_entries = fdefaults->dir_entries; 1595 bpb->fat_sectors = fdefaults->nr_sectors; 1596 bpb->fat_fat_length = fdefaults->fat_length; 1597 1598 error = 0; 1599 1600out: 1601 return error; 1602} 1603 1604/* 1605 * Read the super block of an MS-DOS FS. 1606 */ 1607int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1608 void (*setup)(struct super_block *)) 1609{ 1610 struct inode *root_inode = NULL, *fat_inode = NULL; 1611 struct inode *fsinfo_inode = NULL; 1612 struct buffer_head *bh; 1613 struct fat_bios_param_block bpb; 1614 struct msdos_sb_info *sbi; 1615 u16 logical_sector_size; 1616 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1617 int debug; 1618 long error; 1619 char buf[50]; 1620 struct timespec64 ts; 1621 1622 /* 1623 * GFP_KERNEL is ok here, because while we do hold the 1624 * superblock lock, memory pressure can't call back into 1625 * the filesystem, since we're only just about to mount 1626 * it and have no inodes etc active! 1627 */ 1628 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1629 if (!sbi) 1630 return -ENOMEM; 1631 sb->s_fs_info = sbi; 1632 1633 sb->s_flags |= SB_NODIRATIME; 1634 sb->s_magic = MSDOS_SUPER_MAGIC; 1635 sb->s_op = &fat_sops; 1636 sb->s_export_op = &fat_export_ops; 1637 /* 1638 * fat timestamps are complex and truncated by fat itself, so 1639 * we set 1 here to be fast 1640 */ 1641 sb->s_time_gran = 1; 1642 mutex_init(&sbi->nfs_build_inode_lock); 1643 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1644 DEFAULT_RATELIMIT_BURST); 1645 1646 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1647 if (error) 1648 goto out_fail; 1649 1650 setup(sb); /* flavour-specific stuff that needs options */ 1651 1652 error = -EIO; 1653 sb_min_blocksize(sb, 512); 1654 bh = sb_bread(sb, 0); 1655 if (bh == NULL) { 1656 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1657 goto out_fail; 1658 } 1659 1660 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1661 &bpb); 1662 if (error == -EINVAL && sbi->options.dos1xfloppy) 1663 error = fat_read_static_bpb(sb, 1664 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1665 brelse(bh); 1666 1667 if (error == -EINVAL) 1668 goto out_invalid; 1669 else if (error) 1670 goto out_fail; 1671 1672 logical_sector_size = bpb.fat_sector_size; 1673 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1674 1675 error = -EIO; 1676 if (logical_sector_size < sb->s_blocksize) { 1677 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1678 " (logical sector size = %u)", logical_sector_size); 1679 goto out_fail; 1680 } 1681 1682 if (logical_sector_size > sb->s_blocksize) { 1683 struct buffer_head *bh_resize; 1684 1685 if (!sb_set_blocksize(sb, logical_sector_size)) { 1686 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1687 logical_sector_size); 1688 goto out_fail; 1689 } 1690 1691 /* Verify that the larger boot sector is fully readable */ 1692 bh_resize = sb_bread(sb, 0); 1693 if (bh_resize == NULL) { 1694 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1695 " (logical sector size = %lu)", 1696 sb->s_blocksize); 1697 goto out_fail; 1698 } 1699 brelse(bh_resize); 1700 } 1701 1702 mutex_init(&sbi->s_lock); 1703 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1704 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1705 sbi->fats = bpb.fat_fats; 1706 sbi->fat_bits = 0; /* Don't know yet */ 1707 sbi->fat_start = bpb.fat_reserved; 1708 sbi->fat_length = bpb.fat_fat_length; 1709 sbi->root_cluster = 0; 1710 sbi->free_clusters = -1; /* Don't know yet */ 1711 sbi->free_clus_valid = 0; 1712 sbi->prev_free = FAT_START_ENT; 1713 sb->s_maxbytes = 0xffffffff; 1714 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1715 sb->s_time_min = ts.tv_sec; 1716 1717 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1718 cpu_to_le16(FAT_DATE_MAX), 0); 1719 sb->s_time_max = ts.tv_sec; 1720 1721 if (!sbi->fat_length && bpb.fat32_length) { 1722 struct fat_boot_fsinfo *fsinfo; 1723 struct buffer_head *fsinfo_bh; 1724 1725 /* Must be FAT32 */ 1726 sbi->fat_bits = 32; 1727 sbi->fat_length = bpb.fat32_length; 1728 sbi->root_cluster = bpb.fat32_root_cluster; 1729 1730 /* MC - if info_sector is 0, don't multiply by 0 */ 1731 sbi->fsinfo_sector = bpb.fat32_info_sector; 1732 if (sbi->fsinfo_sector == 0) 1733 sbi->fsinfo_sector = 1; 1734 1735 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1736 if (fsinfo_bh == NULL) { 1737 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1738 " (sector = %lu)", sbi->fsinfo_sector); 1739 goto out_fail; 1740 } 1741 1742 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1743 if (!IS_FSINFO(fsinfo)) { 1744 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1745 "0x%08x, 0x%08x (sector = %lu)", 1746 le32_to_cpu(fsinfo->signature1), 1747 le32_to_cpu(fsinfo->signature2), 1748 sbi->fsinfo_sector); 1749 } else { 1750 if (sbi->options.usefree) 1751 sbi->free_clus_valid = 1; 1752 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1753 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1754 } 1755 1756 brelse(fsinfo_bh); 1757 } 1758 1759 /* interpret volume ID as a little endian 32 bit integer */ 1760 if (is_fat32(sbi)) 1761 sbi->vol_id = bpb.fat32_vol_id; 1762 else /* fat 16 or 12 */ 1763 sbi->vol_id = bpb.fat16_vol_id; 1764 1765 __le32 vol_id_le = cpu_to_le32(sbi->vol_id); 1766 super_set_uuid(sb, (void *) &vol_id_le, sizeof(vol_id_le)); 1767 1768 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1769 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1770 1771 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1772 sbi->dir_entries = bpb.fat_dir_entries; 1773 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1774 if (!silent) 1775 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1776 " (%u)", sbi->dir_entries); 1777 goto out_invalid; 1778 } 1779 1780 rootdir_sectors = sbi->dir_entries 1781 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1782 sbi->data_start = sbi->dir_start + rootdir_sectors; 1783 total_sectors = bpb.fat_sectors; 1784 if (total_sectors == 0) 1785 total_sectors = bpb.fat_total_sect; 1786 1787 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1788 1789 if (!is_fat32(sbi)) 1790 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1791 1792 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1793 if (is_fat32(sbi)) 1794 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1795 else /* fat 16 or 12 */ 1796 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1797 1798 /* check that FAT table does not overflow */ 1799 fat_clusters = calc_fat_clusters(sb); 1800 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1801 if (total_clusters > max_fat(sb)) { 1802 if (!silent) 1803 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1804 total_clusters); 1805 goto out_invalid; 1806 } 1807 1808 sbi->max_cluster = total_clusters + FAT_START_ENT; 1809 /* check the free_clusters, it's not necessarily correct */ 1810 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1811 sbi->free_clusters = -1; 1812 /* check the prev_free, it's not necessarily correct */ 1813 sbi->prev_free %= sbi->max_cluster; 1814 if (sbi->prev_free < FAT_START_ENT) 1815 sbi->prev_free = FAT_START_ENT; 1816 1817 /* set up enough so that it can read an inode */ 1818 fat_hash_init(sb); 1819 dir_hash_init(sb); 1820 fat_ent_access_init(sb); 1821 1822 /* 1823 * The low byte of the first FAT entry must have the same value as 1824 * the media field of the boot sector. But in real world, too many 1825 * devices are writing wrong values. So, removed that validity check. 1826 * 1827 * The removed check compared the first FAT entry to a value dependent 1828 * on the media field like this: 1829 * == (0x0F00 | media), for FAT12 1830 * == (0XFF00 | media), for FAT16 1831 * == (0x0FFFFF | media), for FAT32 1832 */ 1833 1834 error = -EINVAL; 1835 sprintf(buf, "cp%d", sbi->options.codepage); 1836 sbi->nls_disk = load_nls(buf); 1837 if (!sbi->nls_disk) { 1838 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1839 goto out_fail; 1840 } 1841 1842 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1843 if (sbi->options.isvfat) { 1844 sbi->nls_io = load_nls(sbi->options.iocharset); 1845 if (!sbi->nls_io) { 1846 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1847 sbi->options.iocharset); 1848 goto out_fail; 1849 } 1850 } 1851 1852 error = -ENOMEM; 1853 fat_inode = new_inode(sb); 1854 if (!fat_inode) 1855 goto out_fail; 1856 sbi->fat_inode = fat_inode; 1857 1858 fsinfo_inode = new_inode(sb); 1859 if (!fsinfo_inode) 1860 goto out_fail; 1861 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1862 sbi->fsinfo_inode = fsinfo_inode; 1863 insert_inode_hash(fsinfo_inode); 1864 1865 root_inode = new_inode(sb); 1866 if (!root_inode) 1867 goto out_fail; 1868 root_inode->i_ino = MSDOS_ROOT_INO; 1869 inode_set_iversion(root_inode, 1); 1870 error = fat_read_root(root_inode); 1871 if (error < 0) { 1872 iput(root_inode); 1873 goto out_fail; 1874 } 1875 error = -ENOMEM; 1876 insert_inode_hash(root_inode); 1877 fat_attach(root_inode, 0); 1878 sb->s_root = d_make_root(root_inode); 1879 if (!sb->s_root) { 1880 fat_msg(sb, KERN_ERR, "get root inode failed"); 1881 goto out_fail; 1882 } 1883 1884 if (sbi->options.discard && !bdev_max_discard_sectors(sb->s_bdev)) 1885 fat_msg(sb, KERN_WARNING, 1886 "mounting with \"discard\" option, but the device does not support discard"); 1887 1888 fat_set_state(sb, 1, 0); 1889 return 0; 1890 1891out_invalid: 1892 error = -EINVAL; 1893 if (!silent) 1894 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1895 1896out_fail: 1897 iput(fsinfo_inode); 1898 iput(fat_inode); 1899 unload_nls(sbi->nls_io); 1900 unload_nls(sbi->nls_disk); 1901 fat_reset_iocharset(&sbi->options); 1902 sb->s_fs_info = NULL; 1903 kfree(sbi); 1904 return error; 1905} 1906 1907EXPORT_SYMBOL_GPL(fat_fill_super); 1908 1909/* 1910 * helper function for fat_flush_inodes. This writes both the inode 1911 * and the file data blocks, waiting for in flight data blocks before 1912 * the start of the call. It does not wait for any io started 1913 * during the call 1914 */ 1915static int writeback_inode(struct inode *inode) 1916{ 1917 1918 int ret; 1919 1920 /* if we used wait=1, sync_inode_metadata waits for the io for the 1921 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1922 * and filemap_fdatawrite is used for the data blocks 1923 */ 1924 ret = sync_inode_metadata(inode, 0); 1925 if (!ret) 1926 ret = filemap_fdatawrite(inode->i_mapping); 1927 return ret; 1928} 1929 1930/* 1931 * write data and metadata corresponding to i1 and i2. The io is 1932 * started but we do not wait for any of it to finish. 1933 * 1934 * filemap_flush is used for the block device, so if there is a dirty 1935 * page for a block already in flight, we will not wait and start the 1936 * io over again 1937 */ 1938int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1939{ 1940 int ret = 0; 1941 if (!MSDOS_SB(sb)->options.flush) 1942 return 0; 1943 if (i1) 1944 ret = writeback_inode(i1); 1945 if (!ret && i2) 1946 ret = writeback_inode(i2); 1947 if (!ret) 1948 ret = sync_blockdev_nowait(sb->s_bdev); 1949 return ret; 1950} 1951EXPORT_SYMBOL_GPL(fat_flush_inodes); 1952 1953static int __init init_fat_fs(void) 1954{ 1955 int err; 1956 1957 err = fat_cache_init(); 1958 if (err) 1959 return err; 1960 1961 err = fat_init_inodecache(); 1962 if (err) 1963 goto failed; 1964 1965 return 0; 1966 1967failed: 1968 fat_cache_destroy(); 1969 return err; 1970} 1971 1972static void __exit exit_fat_fs(void) 1973{ 1974 fat_cache_destroy(); 1975 fat_destroy_inodecache(); 1976} 1977 1978module_init(init_fat_fs) 1979module_exit(exit_fat_fs) 1980 1981MODULE_LICENSE("GPL"); 1982