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