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_writepage(struct page *page, struct writeback_control *wbc) 198{ 199 return block_write_full_page(page, fat_get_block, wbc); 200} 201 202static int fat_writepages(struct address_space *mapping, 203 struct writeback_control *wbc) 204{ 205 return mpage_writepages(mapping, wbc, fat_get_block); 206} 207 208static int fat_readpage(struct file *file, struct page *page) 209{ 210 return mpage_readpage(page, fat_get_block); 211} 212 213static void fat_readahead(struct readahead_control *rac) 214{ 215 mpage_readahead(rac, fat_get_block); 216} 217 218static void fat_write_failed(struct address_space *mapping, loff_t to) 219{ 220 struct inode *inode = mapping->host; 221 222 if (to > inode->i_size) { 223 truncate_pagecache(inode, inode->i_size); 224 fat_truncate_blocks(inode, inode->i_size); 225 } 226} 227 228static int fat_write_begin(struct file *file, struct address_space *mapping, 229 loff_t pos, unsigned len, unsigned flags, 230 struct page **pagep, void **fsdata) 231{ 232 int err; 233 234 *pagep = NULL; 235 err = cont_write_begin(file, mapping, pos, len, flags, 236 pagep, fsdata, fat_get_block, 237 &MSDOS_I(mapping->host)->mmu_private); 238 if (err < 0) 239 fat_write_failed(mapping, pos + len); 240 return err; 241} 242 243static int fat_write_end(struct file *file, struct address_space *mapping, 244 loff_t pos, unsigned len, unsigned copied, 245 struct page *pagep, void *fsdata) 246{ 247 struct inode *inode = mapping->host; 248 int err; 249 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 250 if (err < len) 251 fat_write_failed(mapping, pos + len); 252 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 253 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); 254 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 255 mark_inode_dirty(inode); 256 } 257 return err; 258} 259 260static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 261{ 262 struct file *file = iocb->ki_filp; 263 struct address_space *mapping = file->f_mapping; 264 struct inode *inode = mapping->host; 265 size_t count = iov_iter_count(iter); 266 loff_t offset = iocb->ki_pos; 267 ssize_t ret; 268 269 if (iov_iter_rw(iter) == WRITE) { 270 /* 271 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 272 * so we need to update the ->mmu_private to block boundary. 273 * 274 * But we must fill the remaining area or hole by nul for 275 * updating ->mmu_private. 276 * 277 * Return 0, and fallback to normal buffered write. 278 */ 279 loff_t size = offset + count; 280 if (MSDOS_I(inode)->mmu_private < size) 281 return 0; 282 } 283 284 /* 285 * FAT need to use the DIO_LOCKING for avoiding the race 286 * condition of fat_get_block() and ->truncate(). 287 */ 288 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 289 if (ret < 0 && iov_iter_rw(iter) == WRITE) 290 fat_write_failed(mapping, offset + count); 291 292 return ret; 293} 294 295static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 296 struct buffer_head *bh_result, int create) 297{ 298 struct super_block *sb = inode->i_sb; 299 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 300 int err; 301 sector_t bmap; 302 unsigned long mapped_blocks; 303 304 BUG_ON(create != 0); 305 306 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 307 if (err) 308 return err; 309 310 if (bmap) { 311 map_bh(bh_result, sb, bmap); 312 max_blocks = min(mapped_blocks, max_blocks); 313 } 314 315 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 316 317 return 0; 318} 319 320static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 321{ 322 sector_t blocknr; 323 324 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 325 down_read(&MSDOS_I(mapping->host)->truncate_lock); 326 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 327 up_read(&MSDOS_I(mapping->host)->truncate_lock); 328 329 return blocknr; 330} 331 332/* 333 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 334 * up to the end of the block which corresponds to `from'. 335 * This is required during truncate to physically zeroout the tail end 336 * of that block so it doesn't yield old data if the file is later grown. 337 * Also, avoid causing failure from fsx for cases of "data past EOF" 338 */ 339int fat_block_truncate_page(struct inode *inode, loff_t from) 340{ 341 return block_truncate_page(inode->i_mapping, from, fat_get_block); 342} 343 344static const struct address_space_operations fat_aops = { 345 .readpage = fat_readpage, 346 .readahead = fat_readahead, 347 .writepage = fat_writepage, 348 .writepages = fat_writepages, 349 .write_begin = fat_write_begin, 350 .write_end = fat_write_end, 351 .direct_IO = fat_direct_IO, 352 .bmap = _fat_bmap 353}; 354 355/* 356 * New FAT inode stuff. We do the following: 357 * a) i_ino is constant and has nothing with on-disk location. 358 * b) FAT manages its own cache of directory entries. 359 * c) *This* cache is indexed by on-disk location. 360 * d) inode has an associated directory entry, all right, but 361 * it may be unhashed. 362 * e) currently entries are stored within struct inode. That should 363 * change. 364 * f) we deal with races in the following way: 365 * 1. readdir() and lookup() do FAT-dir-cache lookup. 366 * 2. rename() unhashes the F-d-c entry and rehashes it in 367 * a new place. 368 * 3. unlink() and rmdir() unhash F-d-c entry. 369 * 4. fat_write_inode() checks whether the thing is unhashed. 370 * If it is we silently return. If it isn't we do bread(), 371 * check if the location is still valid and retry if it 372 * isn't. Otherwise we do changes. 373 * 5. Spinlock is used to protect hash/unhash/location check/lookup 374 * 6. fat_evict_inode() unhashes the F-d-c entry. 375 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 376 * and consider negative result as cache miss. 377 */ 378 379static void fat_hash_init(struct super_block *sb) 380{ 381 struct msdos_sb_info *sbi = MSDOS_SB(sb); 382 int i; 383 384 spin_lock_init(&sbi->inode_hash_lock); 385 for (i = 0; i < FAT_HASH_SIZE; i++) 386 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 387} 388 389static inline unsigned long fat_hash(loff_t i_pos) 390{ 391 return hash_32(i_pos, FAT_HASH_BITS); 392} 393 394static void dir_hash_init(struct super_block *sb) 395{ 396 struct msdos_sb_info *sbi = MSDOS_SB(sb); 397 int i; 398 399 spin_lock_init(&sbi->dir_hash_lock); 400 for (i = 0; i < FAT_HASH_SIZE; i++) 401 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 402} 403 404void fat_attach(struct inode *inode, loff_t i_pos) 405{ 406 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 407 408 if (inode->i_ino != MSDOS_ROOT_INO) { 409 struct hlist_head *head = sbi->inode_hashtable 410 + fat_hash(i_pos); 411 412 spin_lock(&sbi->inode_hash_lock); 413 MSDOS_I(inode)->i_pos = i_pos; 414 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 415 spin_unlock(&sbi->inode_hash_lock); 416 } 417 418 /* If NFS support is enabled, cache the mapping of start cluster 419 * to directory inode. This is used during reconnection of 420 * dentries to the filesystem root. 421 */ 422 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 423 struct hlist_head *d_head = sbi->dir_hashtable; 424 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 425 426 spin_lock(&sbi->dir_hash_lock); 427 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 428 spin_unlock(&sbi->dir_hash_lock); 429 } 430} 431EXPORT_SYMBOL_GPL(fat_attach); 432 433void fat_detach(struct inode *inode) 434{ 435 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 436 spin_lock(&sbi->inode_hash_lock); 437 MSDOS_I(inode)->i_pos = 0; 438 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 439 spin_unlock(&sbi->inode_hash_lock); 440 441 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 442 spin_lock(&sbi->dir_hash_lock); 443 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 444 spin_unlock(&sbi->dir_hash_lock); 445 } 446} 447EXPORT_SYMBOL_GPL(fat_detach); 448 449struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 450{ 451 struct msdos_sb_info *sbi = MSDOS_SB(sb); 452 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 453 struct msdos_inode_info *i; 454 struct inode *inode = NULL; 455 456 spin_lock(&sbi->inode_hash_lock); 457 hlist_for_each_entry(i, head, i_fat_hash) { 458 BUG_ON(i->vfs_inode.i_sb != sb); 459 if (i->i_pos != i_pos) 460 continue; 461 inode = igrab(&i->vfs_inode); 462 if (inode) 463 break; 464 } 465 spin_unlock(&sbi->inode_hash_lock); 466 return inode; 467} 468 469static int is_exec(unsigned char *extension) 470{ 471 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 472 473 for (walk = exe_extensions; *walk; walk += 3) 474 if (!strncmp(extension, walk, 3)) 475 return 1; 476 return 0; 477} 478 479static int fat_calc_dir_size(struct inode *inode) 480{ 481 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 482 int ret, fclus, dclus; 483 484 inode->i_size = 0; 485 if (MSDOS_I(inode)->i_start == 0) 486 return 0; 487 488 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 489 if (ret < 0) 490 return ret; 491 inode->i_size = (fclus + 1) << sbi->cluster_bits; 492 493 return 0; 494} 495 496static int fat_validate_dir(struct inode *dir) 497{ 498 struct super_block *sb = dir->i_sb; 499 500 if (dir->i_nlink < 2) { 501 /* Directory should have "."/".." entries at least. */ 502 fat_fs_error(sb, "corrupted directory (invalid entries)"); 503 return -EIO; 504 } 505 if (MSDOS_I(dir)->i_start == 0 || 506 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 507 /* Directory should point valid cluster. */ 508 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 509 return -EIO; 510 } 511 return 0; 512} 513 514/* doesn't deal with root inode */ 515int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 516{ 517 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 518 int error; 519 520 MSDOS_I(inode)->i_pos = 0; 521 inode->i_uid = sbi->options.fs_uid; 522 inode->i_gid = sbi->options.fs_gid; 523 inode_inc_iversion(inode); 524 inode->i_generation = prandom_u32(); 525 526 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 527 inode->i_generation &= ~1; 528 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 529 inode->i_op = sbi->dir_ops; 530 inode->i_fop = &fat_dir_operations; 531 532 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 533 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 534 error = fat_calc_dir_size(inode); 535 if (error < 0) 536 return error; 537 MSDOS_I(inode)->mmu_private = inode->i_size; 538 539 set_nlink(inode, fat_subdirs(inode)); 540 541 error = fat_validate_dir(inode); 542 if (error < 0) 543 return error; 544 } else { /* not a directory */ 545 inode->i_generation |= 1; 546 inode->i_mode = fat_make_mode(sbi, de->attr, 547 ((sbi->options.showexec && !is_exec(de->name + 8)) 548 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 549 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 550 551 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 552 inode->i_size = le32_to_cpu(de->size); 553 inode->i_op = &fat_file_inode_operations; 554 inode->i_fop = &fat_file_operations; 555 inode->i_mapping->a_ops = &fat_aops; 556 MSDOS_I(inode)->mmu_private = inode->i_size; 557 } 558 if (de->attr & ATTR_SYS) { 559 if (sbi->options.sys_immutable) 560 inode->i_flags |= S_IMMUTABLE; 561 } 562 fat_save_attrs(inode, de->attr); 563 564 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 565 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 566 567 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 568 if (sbi->options.isvfat) { 569 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 570 de->cdate, de->ctime_cs); 571 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 572 } else 573 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME); 574 575 return 0; 576} 577 578static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 579{ 580 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 581 mutex_lock(&sbi->nfs_build_inode_lock); 582} 583 584static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 585{ 586 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 587 mutex_unlock(&sbi->nfs_build_inode_lock); 588} 589 590struct inode *fat_build_inode(struct super_block *sb, 591 struct msdos_dir_entry *de, loff_t i_pos) 592{ 593 struct inode *inode; 594 int err; 595 596 fat_lock_build_inode(MSDOS_SB(sb)); 597 inode = fat_iget(sb, i_pos); 598 if (inode) 599 goto out; 600 inode = new_inode(sb); 601 if (!inode) { 602 inode = ERR_PTR(-ENOMEM); 603 goto out; 604 } 605 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 606 inode_set_iversion(inode, 1); 607 err = fat_fill_inode(inode, de); 608 if (err) { 609 iput(inode); 610 inode = ERR_PTR(err); 611 goto out; 612 } 613 fat_attach(inode, i_pos); 614 insert_inode_hash(inode); 615out: 616 fat_unlock_build_inode(MSDOS_SB(sb)); 617 return inode; 618} 619 620EXPORT_SYMBOL_GPL(fat_build_inode); 621 622static int __fat_write_inode(struct inode *inode, int wait); 623 624static void fat_free_eofblocks(struct inode *inode) 625{ 626 /* Release unwritten fallocated blocks on inode eviction. */ 627 if ((inode->i_blocks << 9) > 628 round_up(MSDOS_I(inode)->mmu_private, 629 MSDOS_SB(inode->i_sb)->cluster_size)) { 630 int err; 631 632 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 633 /* Fallocate results in updating the i_start/iogstart 634 * for the zero byte file. So, make it return to 635 * original state during evict and commit it to avoid 636 * any corruption on the next access to the cluster 637 * chain for the file. 638 */ 639 err = __fat_write_inode(inode, inode_needs_sync(inode)); 640 if (err) { 641 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 642 "update on disk inode for unused " 643 "fallocated blocks, inode could be " 644 "corrupted. Please run fsck"); 645 } 646 647 } 648} 649 650static void fat_evict_inode(struct inode *inode) 651{ 652 truncate_inode_pages_final(&inode->i_data); 653 if (!inode->i_nlink) { 654 inode->i_size = 0; 655 fat_truncate_blocks(inode, 0); 656 } else 657 fat_free_eofblocks(inode); 658 659 invalidate_inode_buffers(inode); 660 clear_inode(inode); 661 fat_cache_inval_inode(inode); 662 fat_detach(inode); 663} 664 665static void fat_set_state(struct super_block *sb, 666 unsigned int set, unsigned int force) 667{ 668 struct buffer_head *bh; 669 struct fat_boot_sector *b; 670 struct msdos_sb_info *sbi = MSDOS_SB(sb); 671 672 /* do not change any thing if mounted read only */ 673 if (sb_rdonly(sb) && !force) 674 return; 675 676 /* do not change state if fs was dirty */ 677 if (sbi->dirty) { 678 /* warn only on set (mount). */ 679 if (set) 680 fat_msg(sb, KERN_WARNING, "Volume was not properly " 681 "unmounted. Some data may be corrupt. " 682 "Please run fsck."); 683 return; 684 } 685 686 bh = sb_bread(sb, 0); 687 if (bh == NULL) { 688 fat_msg(sb, KERN_ERR, "unable to read boot sector " 689 "to mark fs as dirty"); 690 return; 691 } 692 693 b = (struct fat_boot_sector *) bh->b_data; 694 695 if (is_fat32(sbi)) { 696 if (set) 697 b->fat32.state |= FAT_STATE_DIRTY; 698 else 699 b->fat32.state &= ~FAT_STATE_DIRTY; 700 } else /* fat 16 and 12 */ { 701 if (set) 702 b->fat16.state |= FAT_STATE_DIRTY; 703 else 704 b->fat16.state &= ~FAT_STATE_DIRTY; 705 } 706 707 mark_buffer_dirty(bh); 708 sync_dirty_buffer(bh); 709 brelse(bh); 710} 711 712static void fat_reset_iocharset(struct fat_mount_options *opts) 713{ 714 if (opts->iocharset != fat_default_iocharset) { 715 /* Note: opts->iocharset can be NULL here */ 716 kfree(opts->iocharset); 717 opts->iocharset = fat_default_iocharset; 718 } 719} 720 721static void delayed_free(struct rcu_head *p) 722{ 723 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 724 unload_nls(sbi->nls_disk); 725 unload_nls(sbi->nls_io); 726 fat_reset_iocharset(&sbi->options); 727 kfree(sbi); 728} 729 730static void fat_put_super(struct super_block *sb) 731{ 732 struct msdos_sb_info *sbi = MSDOS_SB(sb); 733 734 fat_set_state(sb, 0, 0); 735 736 iput(sbi->fsinfo_inode); 737 iput(sbi->fat_inode); 738 739 call_rcu(&sbi->rcu, delayed_free); 740} 741 742static struct kmem_cache *fat_inode_cachep; 743 744static struct inode *fat_alloc_inode(struct super_block *sb) 745{ 746 struct msdos_inode_info *ei; 747 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 748 if (!ei) 749 return NULL; 750 751 init_rwsem(&ei->truncate_lock); 752 /* Zeroing to allow iput() even if partial initialized inode. */ 753 ei->mmu_private = 0; 754 ei->i_start = 0; 755 ei->i_logstart = 0; 756 ei->i_attrs = 0; 757 ei->i_pos = 0; 758 759 return &ei->vfs_inode; 760} 761 762static void fat_free_inode(struct inode *inode) 763{ 764 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 765} 766 767static void init_once(void *foo) 768{ 769 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 770 771 spin_lock_init(&ei->cache_lru_lock); 772 ei->nr_caches = 0; 773 ei->cache_valid_id = FAT_CACHE_VALID + 1; 774 INIT_LIST_HEAD(&ei->cache_lru); 775 INIT_HLIST_NODE(&ei->i_fat_hash); 776 INIT_HLIST_NODE(&ei->i_dir_hash); 777 inode_init_once(&ei->vfs_inode); 778} 779 780static int __init fat_init_inodecache(void) 781{ 782 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 783 sizeof(struct msdos_inode_info), 784 0, (SLAB_RECLAIM_ACCOUNT| 785 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 786 init_once); 787 if (fat_inode_cachep == NULL) 788 return -ENOMEM; 789 return 0; 790} 791 792static void __exit fat_destroy_inodecache(void) 793{ 794 /* 795 * Make sure all delayed rcu free inodes are flushed before we 796 * destroy cache. 797 */ 798 rcu_barrier(); 799 kmem_cache_destroy(fat_inode_cachep); 800} 801 802static int fat_remount(struct super_block *sb, int *flags, char *data) 803{ 804 bool new_rdonly; 805 struct msdos_sb_info *sbi = MSDOS_SB(sb); 806 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 807 808 sync_filesystem(sb); 809 810 /* make sure we update state on remount. */ 811 new_rdonly = *flags & SB_RDONLY; 812 if (new_rdonly != sb_rdonly(sb)) { 813 if (new_rdonly) 814 fat_set_state(sb, 0, 0); 815 else 816 fat_set_state(sb, 1, 1); 817 } 818 return 0; 819} 820 821static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 822{ 823 struct super_block *sb = dentry->d_sb; 824 struct msdos_sb_info *sbi = MSDOS_SB(sb); 825 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 826 827 /* If the count of free cluster is still unknown, counts it here. */ 828 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 829 int err = fat_count_free_clusters(dentry->d_sb); 830 if (err) 831 return err; 832 } 833 834 buf->f_type = dentry->d_sb->s_magic; 835 buf->f_bsize = sbi->cluster_size; 836 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 837 buf->f_bfree = sbi->free_clusters; 838 buf->f_bavail = sbi->free_clusters; 839 buf->f_fsid = u64_to_fsid(id); 840 buf->f_namelen = 841 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 842 843 return 0; 844} 845 846static int __fat_write_inode(struct inode *inode, int wait) 847{ 848 struct super_block *sb = inode->i_sb; 849 struct msdos_sb_info *sbi = MSDOS_SB(sb); 850 struct buffer_head *bh; 851 struct msdos_dir_entry *raw_entry; 852 loff_t i_pos; 853 sector_t blocknr; 854 int err, offset; 855 856 if (inode->i_ino == MSDOS_ROOT_INO) 857 return 0; 858 859retry: 860 i_pos = fat_i_pos_read(sbi, inode); 861 if (!i_pos) 862 return 0; 863 864 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 865 bh = sb_bread(sb, blocknr); 866 if (!bh) { 867 fat_msg(sb, KERN_ERR, "unable to read inode block " 868 "for updating (i_pos %lld)", i_pos); 869 return -EIO; 870 } 871 spin_lock(&sbi->inode_hash_lock); 872 if (i_pos != MSDOS_I(inode)->i_pos) { 873 spin_unlock(&sbi->inode_hash_lock); 874 brelse(bh); 875 goto retry; 876 } 877 878 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 879 if (S_ISDIR(inode->i_mode)) 880 raw_entry->size = 0; 881 else 882 raw_entry->size = cpu_to_le32(inode->i_size); 883 raw_entry->attr = fat_make_attrs(inode); 884 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 885 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 886 &raw_entry->date, NULL); 887 if (sbi->options.isvfat) { 888 __le16 atime; 889 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 890 &raw_entry->cdate, &raw_entry->ctime_cs); 891 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 892 &raw_entry->adate, NULL); 893 } 894 spin_unlock(&sbi->inode_hash_lock); 895 mark_buffer_dirty(bh); 896 err = 0; 897 if (wait) 898 err = sync_dirty_buffer(bh); 899 brelse(bh); 900 return err; 901} 902 903static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 904{ 905 int err; 906 907 if (inode->i_ino == MSDOS_FSINFO_INO) { 908 struct super_block *sb = inode->i_sb; 909 910 mutex_lock(&MSDOS_SB(sb)->s_lock); 911 err = fat_clusters_flush(sb); 912 mutex_unlock(&MSDOS_SB(sb)->s_lock); 913 } else 914 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 915 916 return err; 917} 918 919int fat_sync_inode(struct inode *inode) 920{ 921 return __fat_write_inode(inode, 1); 922} 923 924EXPORT_SYMBOL_GPL(fat_sync_inode); 925 926static int fat_show_options(struct seq_file *m, struct dentry *root); 927static const struct super_operations fat_sops = { 928 .alloc_inode = fat_alloc_inode, 929 .free_inode = fat_free_inode, 930 .write_inode = fat_write_inode, 931 .evict_inode = fat_evict_inode, 932 .put_super = fat_put_super, 933 .statfs = fat_statfs, 934 .remount_fs = fat_remount, 935 936 .show_options = fat_show_options, 937}; 938 939static int fat_show_options(struct seq_file *m, struct dentry *root) 940{ 941 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 942 struct fat_mount_options *opts = &sbi->options; 943 int isvfat = opts->isvfat; 944 945 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 946 seq_printf(m, ",uid=%u", 947 from_kuid_munged(&init_user_ns, opts->fs_uid)); 948 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 949 seq_printf(m, ",gid=%u", 950 from_kgid_munged(&init_user_ns, opts->fs_gid)); 951 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 952 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 953 if (opts->allow_utime) 954 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 955 if (sbi->nls_disk) 956 /* strip "cp" prefix from displayed option */ 957 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 958 if (isvfat) { 959 if (sbi->nls_io) 960 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 961 962 switch (opts->shortname) { 963 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 964 seq_puts(m, ",shortname=win95"); 965 break; 966 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 967 seq_puts(m, ",shortname=winnt"); 968 break; 969 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 970 seq_puts(m, ",shortname=mixed"); 971 break; 972 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 973 seq_puts(m, ",shortname=lower"); 974 break; 975 default: 976 seq_puts(m, ",shortname=unknown"); 977 break; 978 } 979 } 980 if (opts->name_check != 'n') 981 seq_printf(m, ",check=%c", opts->name_check); 982 if (opts->usefree) 983 seq_puts(m, ",usefree"); 984 if (opts->quiet) 985 seq_puts(m, ",quiet"); 986 if (opts->showexec) 987 seq_puts(m, ",showexec"); 988 if (opts->sys_immutable) 989 seq_puts(m, ",sys_immutable"); 990 if (!isvfat) { 991 if (opts->dotsOK) 992 seq_puts(m, ",dotsOK=yes"); 993 if (opts->nocase) 994 seq_puts(m, ",nocase"); 995 } else { 996 if (opts->utf8) 997 seq_puts(m, ",utf8"); 998 if (opts->unicode_xlate) 999 seq_puts(m, ",uni_xlate"); 1000 if (!opts->numtail) 1001 seq_puts(m, ",nonumtail"); 1002 if (opts->rodir) 1003 seq_puts(m, ",rodir"); 1004 } 1005 if (opts->flush) 1006 seq_puts(m, ",flush"); 1007 if (opts->tz_set) { 1008 if (opts->time_offset) 1009 seq_printf(m, ",time_offset=%d", opts->time_offset); 1010 else 1011 seq_puts(m, ",tz=UTC"); 1012 } 1013 if (opts->errors == FAT_ERRORS_CONT) 1014 seq_puts(m, ",errors=continue"); 1015 else if (opts->errors == FAT_ERRORS_PANIC) 1016 seq_puts(m, ",errors=panic"); 1017 else 1018 seq_puts(m, ",errors=remount-ro"); 1019 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1020 seq_puts(m, ",nfs=nostale_ro"); 1021 else if (opts->nfs) 1022 seq_puts(m, ",nfs=stale_rw"); 1023 if (opts->discard) 1024 seq_puts(m, ",discard"); 1025 if (opts->dos1xfloppy) 1026 seq_puts(m, ",dos1xfloppy"); 1027 1028 return 0; 1029} 1030 1031enum { 1032 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1033 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1034 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1035 Opt_immutable, Opt_dots, Opt_nodots, 1036 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1037 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1038 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1039 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1040 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1041 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1042}; 1043 1044static const match_table_t fat_tokens = { 1045 {Opt_check_r, "check=relaxed"}, 1046 {Opt_check_s, "check=strict"}, 1047 {Opt_check_n, "check=normal"}, 1048 {Opt_check_r, "check=r"}, 1049 {Opt_check_s, "check=s"}, 1050 {Opt_check_n, "check=n"}, 1051 {Opt_uid, "uid=%u"}, 1052 {Opt_gid, "gid=%u"}, 1053 {Opt_umask, "umask=%o"}, 1054 {Opt_dmask, "dmask=%o"}, 1055 {Opt_fmask, "fmask=%o"}, 1056 {Opt_allow_utime, "allow_utime=%o"}, 1057 {Opt_codepage, "codepage=%u"}, 1058 {Opt_usefree, "usefree"}, 1059 {Opt_nocase, "nocase"}, 1060 {Opt_quiet, "quiet"}, 1061 {Opt_showexec, "showexec"}, 1062 {Opt_debug, "debug"}, 1063 {Opt_immutable, "sys_immutable"}, 1064 {Opt_flush, "flush"}, 1065 {Opt_tz_utc, "tz=UTC"}, 1066 {Opt_time_offset, "time_offset=%d"}, 1067 {Opt_err_cont, "errors=continue"}, 1068 {Opt_err_panic, "errors=panic"}, 1069 {Opt_err_ro, "errors=remount-ro"}, 1070 {Opt_discard, "discard"}, 1071 {Opt_nfs_stale_rw, "nfs"}, 1072 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1073 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1074 {Opt_dos1xfloppy, "dos1xfloppy"}, 1075 {Opt_obsolete, "conv=binary"}, 1076 {Opt_obsolete, "conv=text"}, 1077 {Opt_obsolete, "conv=auto"}, 1078 {Opt_obsolete, "conv=b"}, 1079 {Opt_obsolete, "conv=t"}, 1080 {Opt_obsolete, "conv=a"}, 1081 {Opt_obsolete, "fat=%u"}, 1082 {Opt_obsolete, "blocksize=%u"}, 1083 {Opt_obsolete, "cvf_format=%20s"}, 1084 {Opt_obsolete, "cvf_options=%100s"}, 1085 {Opt_obsolete, "posix"}, 1086 {Opt_err, NULL}, 1087}; 1088static const match_table_t msdos_tokens = { 1089 {Opt_nodots, "nodots"}, 1090 {Opt_nodots, "dotsOK=no"}, 1091 {Opt_dots, "dots"}, 1092 {Opt_dots, "dotsOK=yes"}, 1093 {Opt_err, NULL} 1094}; 1095static const match_table_t vfat_tokens = { 1096 {Opt_charset, "iocharset=%s"}, 1097 {Opt_shortname_lower, "shortname=lower"}, 1098 {Opt_shortname_win95, "shortname=win95"}, 1099 {Opt_shortname_winnt, "shortname=winnt"}, 1100 {Opt_shortname_mixed, "shortname=mixed"}, 1101 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1102 {Opt_utf8_no, "utf8=no"}, 1103 {Opt_utf8_no, "utf8=false"}, 1104 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1105 {Opt_utf8_yes, "utf8=yes"}, 1106 {Opt_utf8_yes, "utf8=true"}, 1107 {Opt_utf8_yes, "utf8"}, 1108 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1109 {Opt_uni_xl_no, "uni_xlate=no"}, 1110 {Opt_uni_xl_no, "uni_xlate=false"}, 1111 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1112 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1113 {Opt_uni_xl_yes, "uni_xlate=true"}, 1114 {Opt_uni_xl_yes, "uni_xlate"}, 1115 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1116 {Opt_nonumtail_no, "nonumtail=no"}, 1117 {Opt_nonumtail_no, "nonumtail=false"}, 1118 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1119 {Opt_nonumtail_yes, "nonumtail=yes"}, 1120 {Opt_nonumtail_yes, "nonumtail=true"}, 1121 {Opt_nonumtail_yes, "nonumtail"}, 1122 {Opt_rodir, "rodir"}, 1123 {Opt_err, NULL} 1124}; 1125 1126static int parse_options(struct super_block *sb, char *options, int is_vfat, 1127 int silent, int *debug, struct fat_mount_options *opts) 1128{ 1129 char *p; 1130 substring_t args[MAX_OPT_ARGS]; 1131 int option; 1132 char *iocharset; 1133 1134 opts->isvfat = is_vfat; 1135 1136 opts->fs_uid = current_uid(); 1137 opts->fs_gid = current_gid(); 1138 opts->fs_fmask = opts->fs_dmask = current_umask(); 1139 opts->allow_utime = -1; 1140 opts->codepage = fat_default_codepage; 1141 fat_reset_iocharset(opts); 1142 if (is_vfat) { 1143 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1144 opts->rodir = 0; 1145 } else { 1146 opts->shortname = 0; 1147 opts->rodir = 1; 1148 } 1149 opts->name_check = 'n'; 1150 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1151 opts->unicode_xlate = 0; 1152 opts->numtail = 1; 1153 opts->usefree = opts->nocase = 0; 1154 opts->tz_set = 0; 1155 opts->nfs = 0; 1156 opts->errors = FAT_ERRORS_RO; 1157 *debug = 0; 1158 1159 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1160 1161 if (!options) 1162 goto out; 1163 1164 while ((p = strsep(&options, ",")) != NULL) { 1165 int token; 1166 if (!*p) 1167 continue; 1168 1169 token = match_token(p, fat_tokens, args); 1170 if (token == Opt_err) { 1171 if (is_vfat) 1172 token = match_token(p, vfat_tokens, args); 1173 else 1174 token = match_token(p, msdos_tokens, args); 1175 } 1176 switch (token) { 1177 case Opt_check_s: 1178 opts->name_check = 's'; 1179 break; 1180 case Opt_check_r: 1181 opts->name_check = 'r'; 1182 break; 1183 case Opt_check_n: 1184 opts->name_check = 'n'; 1185 break; 1186 case Opt_usefree: 1187 opts->usefree = 1; 1188 break; 1189 case Opt_nocase: 1190 if (!is_vfat) 1191 opts->nocase = 1; 1192 else { 1193 /* for backward compatibility */ 1194 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1195 | VFAT_SFN_CREATE_WIN95; 1196 } 1197 break; 1198 case Opt_quiet: 1199 opts->quiet = 1; 1200 break; 1201 case Opt_showexec: 1202 opts->showexec = 1; 1203 break; 1204 case Opt_debug: 1205 *debug = 1; 1206 break; 1207 case Opt_immutable: 1208 opts->sys_immutable = 1; 1209 break; 1210 case Opt_uid: 1211 if (match_int(&args[0], &option)) 1212 return -EINVAL; 1213 opts->fs_uid = make_kuid(current_user_ns(), option); 1214 if (!uid_valid(opts->fs_uid)) 1215 return -EINVAL; 1216 break; 1217 case Opt_gid: 1218 if (match_int(&args[0], &option)) 1219 return -EINVAL; 1220 opts->fs_gid = make_kgid(current_user_ns(), option); 1221 if (!gid_valid(opts->fs_gid)) 1222 return -EINVAL; 1223 break; 1224 case Opt_umask: 1225 if (match_octal(&args[0], &option)) 1226 return -EINVAL; 1227 opts->fs_fmask = opts->fs_dmask = option; 1228 break; 1229 case Opt_dmask: 1230 if (match_octal(&args[0], &option)) 1231 return -EINVAL; 1232 opts->fs_dmask = option; 1233 break; 1234 case Opt_fmask: 1235 if (match_octal(&args[0], &option)) 1236 return -EINVAL; 1237 opts->fs_fmask = option; 1238 break; 1239 case Opt_allow_utime: 1240 if (match_octal(&args[0], &option)) 1241 return -EINVAL; 1242 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1243 break; 1244 case Opt_codepage: 1245 if (match_int(&args[0], &option)) 1246 return -EINVAL; 1247 opts->codepage = option; 1248 break; 1249 case Opt_flush: 1250 opts->flush = 1; 1251 break; 1252 case Opt_time_offset: 1253 if (match_int(&args[0], &option)) 1254 return -EINVAL; 1255 /* 1256 * GMT+-12 zones may have DST corrections so at least 1257 * 13 hours difference is needed. Make the limit 24 1258 * just in case someone invents something unusual. 1259 */ 1260 if (option < -24 * 60 || option > 24 * 60) 1261 return -EINVAL; 1262 opts->tz_set = 1; 1263 opts->time_offset = option; 1264 break; 1265 case Opt_tz_utc: 1266 opts->tz_set = 1; 1267 opts->time_offset = 0; 1268 break; 1269 case Opt_err_cont: 1270 opts->errors = FAT_ERRORS_CONT; 1271 break; 1272 case Opt_err_panic: 1273 opts->errors = FAT_ERRORS_PANIC; 1274 break; 1275 case Opt_err_ro: 1276 opts->errors = FAT_ERRORS_RO; 1277 break; 1278 case Opt_nfs_stale_rw: 1279 opts->nfs = FAT_NFS_STALE_RW; 1280 break; 1281 case Opt_nfs_nostale_ro: 1282 opts->nfs = FAT_NFS_NOSTALE_RO; 1283 break; 1284 case Opt_dos1xfloppy: 1285 opts->dos1xfloppy = 1; 1286 break; 1287 1288 /* msdos specific */ 1289 case Opt_dots: 1290 opts->dotsOK = 1; 1291 break; 1292 case Opt_nodots: 1293 opts->dotsOK = 0; 1294 break; 1295 1296 /* vfat specific */ 1297 case Opt_charset: 1298 fat_reset_iocharset(opts); 1299 iocharset = match_strdup(&args[0]); 1300 if (!iocharset) 1301 return -ENOMEM; 1302 opts->iocharset = iocharset; 1303 break; 1304 case Opt_shortname_lower: 1305 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1306 | VFAT_SFN_CREATE_WIN95; 1307 break; 1308 case Opt_shortname_win95: 1309 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1310 | VFAT_SFN_CREATE_WIN95; 1311 break; 1312 case Opt_shortname_winnt: 1313 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1314 | VFAT_SFN_CREATE_WINNT; 1315 break; 1316 case Opt_shortname_mixed: 1317 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1318 | VFAT_SFN_CREATE_WIN95; 1319 break; 1320 case Opt_utf8_no: /* 0 or no or false */ 1321 opts->utf8 = 0; 1322 break; 1323 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1324 opts->utf8 = 1; 1325 break; 1326 case Opt_uni_xl_no: /* 0 or no or false */ 1327 opts->unicode_xlate = 0; 1328 break; 1329 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1330 opts->unicode_xlate = 1; 1331 break; 1332 case Opt_nonumtail_no: /* 0 or no or false */ 1333 opts->numtail = 1; /* negated option */ 1334 break; 1335 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1336 opts->numtail = 0; /* negated option */ 1337 break; 1338 case Opt_rodir: 1339 opts->rodir = 1; 1340 break; 1341 case Opt_discard: 1342 opts->discard = 1; 1343 break; 1344 1345 /* obsolete mount options */ 1346 case Opt_obsolete: 1347 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1348 "not supported now", p); 1349 break; 1350 /* unknown option */ 1351 default: 1352 if (!silent) { 1353 fat_msg(sb, KERN_ERR, 1354 "Unrecognized mount option \"%s\" " 1355 "or missing value", p); 1356 } 1357 return -EINVAL; 1358 } 1359 } 1360 1361out: 1362 /* UTF-8 doesn't provide FAT semantics */ 1363 if (!strcmp(opts->iocharset, "utf8")) { 1364 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1365 " for FAT filesystems, filesystem will be " 1366 "case sensitive!"); 1367 } 1368 1369 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1370 if (opts->allow_utime == (unsigned short)-1) 1371 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1372 if (opts->unicode_xlate) 1373 opts->utf8 = 0; 1374 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1375 sb->s_flags |= SB_RDONLY; 1376 sb->s_export_op = &fat_export_ops_nostale; 1377 } 1378 1379 return 0; 1380} 1381 1382static int fat_read_root(struct inode *inode) 1383{ 1384 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1385 int error; 1386 1387 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1388 inode->i_uid = sbi->options.fs_uid; 1389 inode->i_gid = sbi->options.fs_gid; 1390 inode_inc_iversion(inode); 1391 inode->i_generation = 0; 1392 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1393 inode->i_op = sbi->dir_ops; 1394 inode->i_fop = &fat_dir_operations; 1395 if (is_fat32(sbi)) { 1396 MSDOS_I(inode)->i_start = sbi->root_cluster; 1397 error = fat_calc_dir_size(inode); 1398 if (error < 0) 1399 return error; 1400 } else { 1401 MSDOS_I(inode)->i_start = 0; 1402 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1403 } 1404 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1405 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1406 MSDOS_I(inode)->i_logstart = 0; 1407 MSDOS_I(inode)->mmu_private = inode->i_size; 1408 1409 fat_save_attrs(inode, ATTR_DIR); 1410 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1411 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1412 set_nlink(inode, fat_subdirs(inode)+2); 1413 1414 return 0; 1415} 1416 1417static unsigned long calc_fat_clusters(struct super_block *sb) 1418{ 1419 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1420 1421 /* Divide first to avoid overflow */ 1422 if (!is_fat12(sbi)) { 1423 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1424 return ent_per_sec * sbi->fat_length; 1425 } 1426 1427 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1428} 1429 1430static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1431{ 1432 if (get_unaligned_le16(&b->sector_size)) 1433 return false; 1434 if (b->sec_per_clus) 1435 return false; 1436 if (b->reserved) 1437 return false; 1438 if (b->fats) 1439 return false; 1440 if (get_unaligned_le16(&b->dir_entries)) 1441 return false; 1442 if (get_unaligned_le16(&b->sectors)) 1443 return false; 1444 if (b->media) 1445 return false; 1446 if (b->fat_length) 1447 return false; 1448 if (b->secs_track) 1449 return false; 1450 if (b->heads) 1451 return false; 1452 return true; 1453} 1454 1455static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1456 int silent, struct fat_bios_param_block *bpb) 1457{ 1458 int error = -EINVAL; 1459 1460 /* Read in BPB ... */ 1461 memset(bpb, 0, sizeof(*bpb)); 1462 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1463 bpb->fat_sec_per_clus = b->sec_per_clus; 1464 bpb->fat_reserved = le16_to_cpu(b->reserved); 1465 bpb->fat_fats = b->fats; 1466 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1467 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1468 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1469 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1470 1471 bpb->fat16_state = b->fat16.state; 1472 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1473 1474 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1475 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1476 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1477 bpb->fat32_state = b->fat32.state; 1478 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1479 1480 /* Validate this looks like a FAT filesystem BPB */ 1481 if (!bpb->fat_reserved) { 1482 if (!silent) 1483 fat_msg(sb, KERN_ERR, 1484 "bogus number of reserved sectors"); 1485 goto out; 1486 } 1487 if (!bpb->fat_fats) { 1488 if (!silent) 1489 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1490 goto out; 1491 } 1492 1493 /* 1494 * Earlier we checked here that b->secs_track and b->head are nonzero, 1495 * but it turns out valid FAT filesystems can have zero there. 1496 */ 1497 1498 if (!fat_valid_media(b->media)) { 1499 if (!silent) 1500 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1501 (unsigned)b->media); 1502 goto out; 1503 } 1504 1505 if (!is_power_of_2(bpb->fat_sector_size) 1506 || (bpb->fat_sector_size < 512) 1507 || (bpb->fat_sector_size > 4096)) { 1508 if (!silent) 1509 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1510 (unsigned)bpb->fat_sector_size); 1511 goto out; 1512 } 1513 1514 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1515 if (!silent) 1516 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1517 (unsigned)bpb->fat_sec_per_clus); 1518 goto out; 1519 } 1520 1521 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { 1522 if (!silent) 1523 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); 1524 goto out; 1525 } 1526 1527 error = 0; 1528 1529out: 1530 return error; 1531} 1532 1533static int fat_read_static_bpb(struct super_block *sb, 1534 struct fat_boot_sector *b, int silent, 1535 struct fat_bios_param_block *bpb) 1536{ 1537 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1538 1539 struct fat_floppy_defaults *fdefaults = NULL; 1540 int error = -EINVAL; 1541 sector_t bd_sects; 1542 unsigned i; 1543 1544 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1545 1546 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1547 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1548 if (!silent) 1549 fat_msg(sb, KERN_ERR, 1550 "%s; no bootstrapping code", notdos1x); 1551 goto out; 1552 } 1553 1554 /* 1555 * If any value in this region is non-zero, it isn't archaic 1556 * DOS. 1557 */ 1558 if (!fat_bpb_is_zero(b)) { 1559 if (!silent) 1560 fat_msg(sb, KERN_ERR, 1561 "%s; DOS 2.x BPB is non-zero", notdos1x); 1562 goto out; 1563 } 1564 1565 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1566 if (floppy_defaults[i].nr_sectors == bd_sects) { 1567 fdefaults = &floppy_defaults[i]; 1568 break; 1569 } 1570 } 1571 1572 if (fdefaults == NULL) { 1573 if (!silent) 1574 fat_msg(sb, KERN_WARNING, 1575 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1576 (u64)bd_sects); 1577 goto out; 1578 } 1579 1580 if (!silent) 1581 fat_msg(sb, KERN_INFO, 1582 "This looks like a DOS 1.x volume; assuming default BPB values"); 1583 1584 memset(bpb, 0, sizeof(*bpb)); 1585 bpb->fat_sector_size = SECTOR_SIZE; 1586 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1587 bpb->fat_reserved = 1; 1588 bpb->fat_fats = 2; 1589 bpb->fat_dir_entries = fdefaults->dir_entries; 1590 bpb->fat_sectors = fdefaults->nr_sectors; 1591 bpb->fat_fat_length = fdefaults->fat_length; 1592 1593 error = 0; 1594 1595out: 1596 return error; 1597} 1598 1599/* 1600 * Read the super block of an MS-DOS FS. 1601 */ 1602int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1603 void (*setup)(struct super_block *)) 1604{ 1605 struct inode *root_inode = NULL, *fat_inode = NULL; 1606 struct inode *fsinfo_inode = NULL; 1607 struct buffer_head *bh; 1608 struct fat_bios_param_block bpb; 1609 struct msdos_sb_info *sbi; 1610 u16 logical_sector_size; 1611 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1612 int debug; 1613 long error; 1614 char buf[50]; 1615 struct timespec64 ts; 1616 1617 /* 1618 * GFP_KERNEL is ok here, because while we do hold the 1619 * superblock lock, memory pressure can't call back into 1620 * the filesystem, since we're only just about to mount 1621 * it and have no inodes etc active! 1622 */ 1623 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1624 if (!sbi) 1625 return -ENOMEM; 1626 sb->s_fs_info = sbi; 1627 1628 sb->s_flags |= SB_NODIRATIME; 1629 sb->s_magic = MSDOS_SUPER_MAGIC; 1630 sb->s_op = &fat_sops; 1631 sb->s_export_op = &fat_export_ops; 1632 /* 1633 * fat timestamps are complex and truncated by fat itself, so 1634 * we set 1 here to be fast 1635 */ 1636 sb->s_time_gran = 1; 1637 mutex_init(&sbi->nfs_build_inode_lock); 1638 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1639 DEFAULT_RATELIMIT_BURST); 1640 1641 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1642 if (error) 1643 goto out_fail; 1644 1645 setup(sb); /* flavour-specific stuff that needs options */ 1646 1647 error = -EIO; 1648 sb_min_blocksize(sb, 512); 1649 bh = sb_bread(sb, 0); 1650 if (bh == NULL) { 1651 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1652 goto out_fail; 1653 } 1654 1655 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1656 &bpb); 1657 if (error == -EINVAL && sbi->options.dos1xfloppy) 1658 error = fat_read_static_bpb(sb, 1659 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1660 brelse(bh); 1661 1662 if (error == -EINVAL) 1663 goto out_invalid; 1664 else if (error) 1665 goto out_fail; 1666 1667 logical_sector_size = bpb.fat_sector_size; 1668 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1669 1670 error = -EIO; 1671 if (logical_sector_size < sb->s_blocksize) { 1672 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1673 " (logical sector size = %u)", logical_sector_size); 1674 goto out_fail; 1675 } 1676 1677 if (logical_sector_size > sb->s_blocksize) { 1678 struct buffer_head *bh_resize; 1679 1680 if (!sb_set_blocksize(sb, logical_sector_size)) { 1681 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1682 logical_sector_size); 1683 goto out_fail; 1684 } 1685 1686 /* Verify that the larger boot sector is fully readable */ 1687 bh_resize = sb_bread(sb, 0); 1688 if (bh_resize == NULL) { 1689 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1690 " (logical sector size = %lu)", 1691 sb->s_blocksize); 1692 goto out_fail; 1693 } 1694 brelse(bh_resize); 1695 } 1696 1697 mutex_init(&sbi->s_lock); 1698 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1699 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1700 sbi->fats = bpb.fat_fats; 1701 sbi->fat_bits = 0; /* Don't know yet */ 1702 sbi->fat_start = bpb.fat_reserved; 1703 sbi->fat_length = bpb.fat_fat_length; 1704 sbi->root_cluster = 0; 1705 sbi->free_clusters = -1; /* Don't know yet */ 1706 sbi->free_clus_valid = 0; 1707 sbi->prev_free = FAT_START_ENT; 1708 sb->s_maxbytes = 0xffffffff; 1709 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); 1710 sb->s_time_min = ts.tv_sec; 1711 1712 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), 1713 cpu_to_le16(FAT_DATE_MAX), 0); 1714 sb->s_time_max = ts.tv_sec; 1715 1716 if (!sbi->fat_length && bpb.fat32_length) { 1717 struct fat_boot_fsinfo *fsinfo; 1718 struct buffer_head *fsinfo_bh; 1719 1720 /* Must be FAT32 */ 1721 sbi->fat_bits = 32; 1722 sbi->fat_length = bpb.fat32_length; 1723 sbi->root_cluster = bpb.fat32_root_cluster; 1724 1725 /* MC - if info_sector is 0, don't multiply by 0 */ 1726 sbi->fsinfo_sector = bpb.fat32_info_sector; 1727 if (sbi->fsinfo_sector == 0) 1728 sbi->fsinfo_sector = 1; 1729 1730 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1731 if (fsinfo_bh == NULL) { 1732 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1733 " (sector = %lu)", sbi->fsinfo_sector); 1734 goto out_fail; 1735 } 1736 1737 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1738 if (!IS_FSINFO(fsinfo)) { 1739 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1740 "0x%08x, 0x%08x (sector = %lu)", 1741 le32_to_cpu(fsinfo->signature1), 1742 le32_to_cpu(fsinfo->signature2), 1743 sbi->fsinfo_sector); 1744 } else { 1745 if (sbi->options.usefree) 1746 sbi->free_clus_valid = 1; 1747 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1748 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1749 } 1750 1751 brelse(fsinfo_bh); 1752 } 1753 1754 /* interpret volume ID as a little endian 32 bit integer */ 1755 if (is_fat32(sbi)) 1756 sbi->vol_id = bpb.fat32_vol_id; 1757 else /* fat 16 or 12 */ 1758 sbi->vol_id = bpb.fat16_vol_id; 1759 1760 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1761 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1762 1763 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1764 sbi->dir_entries = bpb.fat_dir_entries; 1765 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1766 if (!silent) 1767 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1768 " (%u)", sbi->dir_entries); 1769 goto out_invalid; 1770 } 1771 1772 rootdir_sectors = sbi->dir_entries 1773 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1774 sbi->data_start = sbi->dir_start + rootdir_sectors; 1775 total_sectors = bpb.fat_sectors; 1776 if (total_sectors == 0) 1777 total_sectors = bpb.fat_total_sect; 1778 1779 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1780 1781 if (!is_fat32(sbi)) 1782 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1783 1784 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1785 if (is_fat32(sbi)) 1786 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1787 else /* fat 16 or 12 */ 1788 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1789 1790 /* check that FAT table does not overflow */ 1791 fat_clusters = calc_fat_clusters(sb); 1792 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1793 if (total_clusters > max_fat(sb)) { 1794 if (!silent) 1795 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1796 total_clusters); 1797 goto out_invalid; 1798 } 1799 1800 sbi->max_cluster = total_clusters + FAT_START_ENT; 1801 /* check the free_clusters, it's not necessarily correct */ 1802 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1803 sbi->free_clusters = -1; 1804 /* check the prev_free, it's not necessarily correct */ 1805 sbi->prev_free %= sbi->max_cluster; 1806 if (sbi->prev_free < FAT_START_ENT) 1807 sbi->prev_free = FAT_START_ENT; 1808 1809 /* set up enough so that it can read an inode */ 1810 fat_hash_init(sb); 1811 dir_hash_init(sb); 1812 fat_ent_access_init(sb); 1813 1814 /* 1815 * The low byte of the first FAT entry must have the same value as 1816 * the media field of the boot sector. But in real world, too many 1817 * devices are writing wrong values. So, removed that validity check. 1818 * 1819 * The removed check compared the first FAT entry to a value dependent 1820 * on the media field like this: 1821 * == (0x0F00 | media), for FAT12 1822 * == (0XFF00 | media), for FAT16 1823 * == (0x0FFFFF | media), for FAT32 1824 */ 1825 1826 error = -EINVAL; 1827 sprintf(buf, "cp%d", sbi->options.codepage); 1828 sbi->nls_disk = load_nls(buf); 1829 if (!sbi->nls_disk) { 1830 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1831 goto out_fail; 1832 } 1833 1834 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1835 if (sbi->options.isvfat) { 1836 sbi->nls_io = load_nls(sbi->options.iocharset); 1837 if (!sbi->nls_io) { 1838 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1839 sbi->options.iocharset); 1840 goto out_fail; 1841 } 1842 } 1843 1844 error = -ENOMEM; 1845 fat_inode = new_inode(sb); 1846 if (!fat_inode) 1847 goto out_fail; 1848 sbi->fat_inode = fat_inode; 1849 1850 fsinfo_inode = new_inode(sb); 1851 if (!fsinfo_inode) 1852 goto out_fail; 1853 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1854 sbi->fsinfo_inode = fsinfo_inode; 1855 insert_inode_hash(fsinfo_inode); 1856 1857 root_inode = new_inode(sb); 1858 if (!root_inode) 1859 goto out_fail; 1860 root_inode->i_ino = MSDOS_ROOT_INO; 1861 inode_set_iversion(root_inode, 1); 1862 error = fat_read_root(root_inode); 1863 if (error < 0) { 1864 iput(root_inode); 1865 goto out_fail; 1866 } 1867 error = -ENOMEM; 1868 insert_inode_hash(root_inode); 1869 fat_attach(root_inode, 0); 1870 sb->s_root = d_make_root(root_inode); 1871 if (!sb->s_root) { 1872 fat_msg(sb, KERN_ERR, "get root inode failed"); 1873 goto out_fail; 1874 } 1875 1876 if (sbi->options.discard) { 1877 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1878 if (!blk_queue_discard(q)) 1879 fat_msg(sb, KERN_WARNING, 1880 "mounting with \"discard\" option, but " 1881 "the device does not support discard"); 1882 } 1883 1884 fat_set_state(sb, 1, 0); 1885 return 0; 1886 1887out_invalid: 1888 error = -EINVAL; 1889 if (!silent) 1890 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1891 1892out_fail: 1893 if (fsinfo_inode) 1894 iput(fsinfo_inode); 1895 if (fat_inode) 1896 iput(fat_inode); 1897 unload_nls(sbi->nls_io); 1898 unload_nls(sbi->nls_disk); 1899 fat_reset_iocharset(&sbi->options); 1900 sb->s_fs_info = NULL; 1901 kfree(sbi); 1902 return error; 1903} 1904 1905EXPORT_SYMBOL_GPL(fat_fill_super); 1906 1907/* 1908 * helper function for fat_flush_inodes. This writes both the inode 1909 * and the file data blocks, waiting for in flight data blocks before 1910 * the start of the call. It does not wait for any io started 1911 * during the call 1912 */ 1913static int writeback_inode(struct inode *inode) 1914{ 1915 1916 int ret; 1917 1918 /* if we used wait=1, sync_inode_metadata waits for the io for the 1919 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1920 * and filemap_fdatawrite is used for the data blocks 1921 */ 1922 ret = sync_inode_metadata(inode, 0); 1923 if (!ret) 1924 ret = filemap_fdatawrite(inode->i_mapping); 1925 return ret; 1926} 1927 1928/* 1929 * write data and metadata corresponding to i1 and i2. The io is 1930 * started but we do not wait for any of it to finish. 1931 * 1932 * filemap_flush is used for the block device, so if there is a dirty 1933 * page for a block already in flight, we will not wait and start the 1934 * io over again 1935 */ 1936int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1937{ 1938 int ret = 0; 1939 if (!MSDOS_SB(sb)->options.flush) 1940 return 0; 1941 if (i1) 1942 ret = writeback_inode(i1); 1943 if (!ret && i2) 1944 ret = writeback_inode(i2); 1945 if (!ret) { 1946 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1947 ret = filemap_flush(mapping); 1948 } 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