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