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/init.h> 15 #include <linux/time.h> 16 #include <linux/slab.h> 17 #include <linux/seq_file.h> 18 #include <linux/pagemap.h> 19 #include <linux/mpage.h> 20 #include <linux/buffer_head.h> 21 #include <linux/mount.h> 22 #include <linux/aio.h> 23 #include <linux/vfs.h> 24 #include <linux/parser.h> 25 #include <linux/uio.h> 26 #include <linux/writeback.h> 27 #include <linux/log2.h> 28 #include <linux/hash.h> 29 #include <linux/blkdev.h> 30 #include <asm/unaligned.h> 31 #include "fat.h" 32 33 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 34 /* if user don't select VFAT, this is undefined. */ 35 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 36 #endif 37 38 #define KB_IN_SECTORS 2 39 40 /* 41 * A deserialized copy of the on-disk structure laid out in struct 42 * fat_boot_sector. 43 */ 44 struct fat_bios_param_block { 45 u16 fat_sector_size; 46 u8 fat_sec_per_clus; 47 u16 fat_reserved; 48 u8 fat_fats; 49 u16 fat_dir_entries; 50 u16 fat_sectors; 51 u16 fat_fat_length; 52 u32 fat_total_sect; 53 54 u8 fat16_state; 55 u32 fat16_vol_id; 56 57 u32 fat32_length; 58 u32 fat32_root_cluster; 59 u16 fat32_info_sector; 60 u8 fat32_state; 61 u32 fat32_vol_id; 62 }; 63 64 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 65 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 66 67 static struct fat_floppy_defaults { 68 unsigned nr_sectors; 69 unsigned sec_per_clus; 70 unsigned dir_entries; 71 unsigned media; 72 unsigned fat_length; 73 } floppy_defaults[] = { 74 { 75 .nr_sectors = 160 * KB_IN_SECTORS, 76 .sec_per_clus = 1, 77 .dir_entries = 64, 78 .media = 0xFE, 79 .fat_length = 1, 80 }, 81 { 82 .nr_sectors = 180 * KB_IN_SECTORS, 83 .sec_per_clus = 1, 84 .dir_entries = 64, 85 .media = 0xFC, 86 .fat_length = 2, 87 }, 88 { 89 .nr_sectors = 320 * KB_IN_SECTORS, 90 .sec_per_clus = 2, 91 .dir_entries = 112, 92 .media = 0xFF, 93 .fat_length = 1, 94 }, 95 { 96 .nr_sectors = 360 * KB_IN_SECTORS, 97 .sec_per_clus = 2, 98 .dir_entries = 112, 99 .media = 0xFD, 100 .fat_length = 2, 101 }, 102 }; 103 104 static int fat_add_cluster(struct inode *inode) 105 { 106 int err, cluster; 107 108 err = fat_alloc_clusters(inode, &cluster, 1); 109 if (err) 110 return err; 111 /* FIXME: this cluster should be added after data of this 112 * cluster is writed */ 113 err = fat_chain_add(inode, cluster, 1); 114 if (err) 115 fat_free_clusters(inode, cluster); 116 return err; 117 } 118 119 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 120 unsigned long *max_blocks, 121 struct buffer_head *bh_result, int create) 122 { 123 struct super_block *sb = inode->i_sb; 124 struct msdos_sb_info *sbi = MSDOS_SB(sb); 125 unsigned long mapped_blocks; 126 sector_t phys; 127 int err, offset; 128 129 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); 130 if (err) 131 return err; 132 if (phys) { 133 map_bh(bh_result, sb, phys); 134 *max_blocks = min(mapped_blocks, *max_blocks); 135 return 0; 136 } 137 if (!create) 138 return 0; 139 140 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 141 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 142 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 143 return -EIO; 144 } 145 146 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 147 if (!offset) { 148 /* TODO: multiple cluster allocation would be desirable. */ 149 err = fat_add_cluster(inode); 150 if (err) 151 return err; 152 } 153 /* available blocks on this cluster */ 154 mapped_blocks = sbi->sec_per_clus - offset; 155 156 *max_blocks = min(mapped_blocks, *max_blocks); 157 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 158 159 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); 160 if (err) 161 return err; 162 163 BUG_ON(!phys); 164 BUG_ON(*max_blocks != mapped_blocks); 165 set_buffer_new(bh_result); 166 map_bh(bh_result, sb, phys); 167 168 return 0; 169 } 170 171 static int fat_get_block(struct inode *inode, sector_t iblock, 172 struct buffer_head *bh_result, int create) 173 { 174 struct super_block *sb = inode->i_sb; 175 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 176 int err; 177 178 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 179 if (err) 180 return err; 181 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 182 return 0; 183 } 184 185 static int fat_writepage(struct page *page, struct writeback_control *wbc) 186 { 187 return block_write_full_page(page, fat_get_block, wbc); 188 } 189 190 static int fat_writepages(struct address_space *mapping, 191 struct writeback_control *wbc) 192 { 193 return mpage_writepages(mapping, wbc, fat_get_block); 194 } 195 196 static int fat_readpage(struct file *file, struct page *page) 197 { 198 return mpage_readpage(page, fat_get_block); 199 } 200 201 static int fat_readpages(struct file *file, struct address_space *mapping, 202 struct list_head *pages, unsigned nr_pages) 203 { 204 return mpage_readpages(mapping, pages, nr_pages, fat_get_block); 205 } 206 207 static void fat_write_failed(struct address_space *mapping, loff_t to) 208 { 209 struct inode *inode = mapping->host; 210 211 if (to > inode->i_size) { 212 truncate_pagecache(inode, inode->i_size); 213 fat_truncate_blocks(inode, inode->i_size); 214 } 215 } 216 217 static int fat_write_begin(struct file *file, struct address_space *mapping, 218 loff_t pos, unsigned len, unsigned flags, 219 struct page **pagep, void **fsdata) 220 { 221 int err; 222 223 *pagep = NULL; 224 err = cont_write_begin(file, mapping, pos, len, flags, 225 pagep, fsdata, fat_get_block, 226 &MSDOS_I(mapping->host)->mmu_private); 227 if (err < 0) 228 fat_write_failed(mapping, pos + len); 229 return err; 230 } 231 232 static int fat_write_end(struct file *file, struct address_space *mapping, 233 loff_t pos, unsigned len, unsigned copied, 234 struct page *pagep, void *fsdata) 235 { 236 struct inode *inode = mapping->host; 237 int err; 238 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 239 if (err < len) 240 fat_write_failed(mapping, pos + len); 241 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 242 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; 243 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 244 mark_inode_dirty(inode); 245 } 246 return err; 247 } 248 249 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb, 250 struct iov_iter *iter, 251 loff_t offset) 252 { 253 struct file *file = iocb->ki_filp; 254 struct address_space *mapping = file->f_mapping; 255 struct inode *inode = mapping->host; 256 size_t count = iov_iter_count(iter); 257 ssize_t ret; 258 259 if (rw == WRITE) { 260 /* 261 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 262 * so we need to update the ->mmu_private to block boundary. 263 * 264 * But we must fill the remaining area or hole by nul for 265 * updating ->mmu_private. 266 * 267 * Return 0, and fallback to normal buffered write. 268 */ 269 loff_t size = offset + count; 270 if (MSDOS_I(inode)->mmu_private < size) 271 return 0; 272 } 273 274 /* 275 * FAT need to use the DIO_LOCKING for avoiding the race 276 * condition of fat_get_block() and ->truncate(). 277 */ 278 ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, fat_get_block); 279 if (ret < 0 && (rw & WRITE)) 280 fat_write_failed(mapping, offset + count); 281 282 return ret; 283 } 284 285 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 286 { 287 sector_t blocknr; 288 289 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 290 down_read(&MSDOS_I(mapping->host)->truncate_lock); 291 blocknr = generic_block_bmap(mapping, block, fat_get_block); 292 up_read(&MSDOS_I(mapping->host)->truncate_lock); 293 294 return blocknr; 295 } 296 297 /* 298 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 299 * up to the end of the block which corresponds to `from'. 300 * This is required during truncate to physically zeroout the tail end 301 * of that block so it doesn't yield old data if the file is later grown. 302 * Also, avoid causing failure from fsx for cases of "data past EOF" 303 */ 304 int fat_block_truncate_page(struct inode *inode, loff_t from) 305 { 306 return block_truncate_page(inode->i_mapping, from, fat_get_block); 307 } 308 309 static const struct address_space_operations fat_aops = { 310 .readpage = fat_readpage, 311 .readpages = fat_readpages, 312 .writepage = fat_writepage, 313 .writepages = fat_writepages, 314 .write_begin = fat_write_begin, 315 .write_end = fat_write_end, 316 .direct_IO = fat_direct_IO, 317 .bmap = _fat_bmap 318 }; 319 320 /* 321 * New FAT inode stuff. We do the following: 322 * a) i_ino is constant and has nothing with on-disk location. 323 * b) FAT manages its own cache of directory entries. 324 * c) *This* cache is indexed by on-disk location. 325 * d) inode has an associated directory entry, all right, but 326 * it may be unhashed. 327 * e) currently entries are stored within struct inode. That should 328 * change. 329 * f) we deal with races in the following way: 330 * 1. readdir() and lookup() do FAT-dir-cache lookup. 331 * 2. rename() unhashes the F-d-c entry and rehashes it in 332 * a new place. 333 * 3. unlink() and rmdir() unhash F-d-c entry. 334 * 4. fat_write_inode() checks whether the thing is unhashed. 335 * If it is we silently return. If it isn't we do bread(), 336 * check if the location is still valid and retry if it 337 * isn't. Otherwise we do changes. 338 * 5. Spinlock is used to protect hash/unhash/location check/lookup 339 * 6. fat_evict_inode() unhashes the F-d-c entry. 340 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 341 * and consider negative result as cache miss. 342 */ 343 344 static void fat_hash_init(struct super_block *sb) 345 { 346 struct msdos_sb_info *sbi = MSDOS_SB(sb); 347 int i; 348 349 spin_lock_init(&sbi->inode_hash_lock); 350 for (i = 0; i < FAT_HASH_SIZE; i++) 351 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 352 } 353 354 static inline unsigned long fat_hash(loff_t i_pos) 355 { 356 return hash_32(i_pos, FAT_HASH_BITS); 357 } 358 359 static void dir_hash_init(struct super_block *sb) 360 { 361 struct msdos_sb_info *sbi = MSDOS_SB(sb); 362 int i; 363 364 spin_lock_init(&sbi->dir_hash_lock); 365 for (i = 0; i < FAT_HASH_SIZE; i++) 366 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 367 } 368 369 void fat_attach(struct inode *inode, loff_t i_pos) 370 { 371 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 372 373 if (inode->i_ino != MSDOS_ROOT_INO) { 374 struct hlist_head *head = sbi->inode_hashtable 375 + fat_hash(i_pos); 376 377 spin_lock(&sbi->inode_hash_lock); 378 MSDOS_I(inode)->i_pos = i_pos; 379 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 380 spin_unlock(&sbi->inode_hash_lock); 381 } 382 383 /* If NFS support is enabled, cache the mapping of start cluster 384 * to directory inode. This is used during reconnection of 385 * dentries to the filesystem root. 386 */ 387 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 388 struct hlist_head *d_head = sbi->dir_hashtable; 389 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 390 391 spin_lock(&sbi->dir_hash_lock); 392 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 393 spin_unlock(&sbi->dir_hash_lock); 394 } 395 } 396 EXPORT_SYMBOL_GPL(fat_attach); 397 398 void fat_detach(struct inode *inode) 399 { 400 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 401 spin_lock(&sbi->inode_hash_lock); 402 MSDOS_I(inode)->i_pos = 0; 403 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 404 spin_unlock(&sbi->inode_hash_lock); 405 406 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 407 spin_lock(&sbi->dir_hash_lock); 408 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 409 spin_unlock(&sbi->dir_hash_lock); 410 } 411 } 412 EXPORT_SYMBOL_GPL(fat_detach); 413 414 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 415 { 416 struct msdos_sb_info *sbi = MSDOS_SB(sb); 417 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 418 struct msdos_inode_info *i; 419 struct inode *inode = NULL; 420 421 spin_lock(&sbi->inode_hash_lock); 422 hlist_for_each_entry(i, head, i_fat_hash) { 423 BUG_ON(i->vfs_inode.i_sb != sb); 424 if (i->i_pos != i_pos) 425 continue; 426 inode = igrab(&i->vfs_inode); 427 if (inode) 428 break; 429 } 430 spin_unlock(&sbi->inode_hash_lock); 431 return inode; 432 } 433 434 static int is_exec(unsigned char *extension) 435 { 436 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 437 438 for (walk = exe_extensions; *walk; walk += 3) 439 if (!strncmp(extension, walk, 3)) 440 return 1; 441 return 0; 442 } 443 444 static int fat_calc_dir_size(struct inode *inode) 445 { 446 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 447 int ret, fclus, dclus; 448 449 inode->i_size = 0; 450 if (MSDOS_I(inode)->i_start == 0) 451 return 0; 452 453 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 454 if (ret < 0) 455 return ret; 456 inode->i_size = (fclus + 1) << sbi->cluster_bits; 457 458 return 0; 459 } 460 461 /* doesn't deal with root inode */ 462 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 463 { 464 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 465 int error; 466 467 MSDOS_I(inode)->i_pos = 0; 468 inode->i_uid = sbi->options.fs_uid; 469 inode->i_gid = sbi->options.fs_gid; 470 inode->i_version++; 471 inode->i_generation = get_seconds(); 472 473 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 474 inode->i_generation &= ~1; 475 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 476 inode->i_op = sbi->dir_ops; 477 inode->i_fop = &fat_dir_operations; 478 479 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 480 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 481 error = fat_calc_dir_size(inode); 482 if (error < 0) 483 return error; 484 MSDOS_I(inode)->mmu_private = inode->i_size; 485 486 set_nlink(inode, fat_subdirs(inode)); 487 } else { /* not a directory */ 488 inode->i_generation |= 1; 489 inode->i_mode = fat_make_mode(sbi, de->attr, 490 ((sbi->options.showexec && !is_exec(de->name + 8)) 491 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 492 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 493 494 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 495 inode->i_size = le32_to_cpu(de->size); 496 inode->i_op = &fat_file_inode_operations; 497 inode->i_fop = &fat_file_operations; 498 inode->i_mapping->a_ops = &fat_aops; 499 MSDOS_I(inode)->mmu_private = inode->i_size; 500 } 501 if (de->attr & ATTR_SYS) { 502 if (sbi->options.sys_immutable) 503 inode->i_flags |= S_IMMUTABLE; 504 } 505 fat_save_attrs(inode, de->attr); 506 507 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 508 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 509 510 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 511 if (sbi->options.isvfat) { 512 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 513 de->cdate, de->ctime_cs); 514 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 515 } else 516 inode->i_ctime = inode->i_atime = inode->i_mtime; 517 518 return 0; 519 } 520 521 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 522 { 523 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 524 mutex_lock(&sbi->nfs_build_inode_lock); 525 } 526 527 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 528 { 529 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 530 mutex_unlock(&sbi->nfs_build_inode_lock); 531 } 532 533 struct inode *fat_build_inode(struct super_block *sb, 534 struct msdos_dir_entry *de, loff_t i_pos) 535 { 536 struct inode *inode; 537 int err; 538 539 fat_lock_build_inode(MSDOS_SB(sb)); 540 inode = fat_iget(sb, i_pos); 541 if (inode) 542 goto out; 543 inode = new_inode(sb); 544 if (!inode) { 545 inode = ERR_PTR(-ENOMEM); 546 goto out; 547 } 548 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 549 inode->i_version = 1; 550 err = fat_fill_inode(inode, de); 551 if (err) { 552 iput(inode); 553 inode = ERR_PTR(err); 554 goto out; 555 } 556 fat_attach(inode, i_pos); 557 insert_inode_hash(inode); 558 out: 559 fat_unlock_build_inode(MSDOS_SB(sb)); 560 return inode; 561 } 562 563 EXPORT_SYMBOL_GPL(fat_build_inode); 564 565 static void fat_evict_inode(struct inode *inode) 566 { 567 truncate_inode_pages_final(&inode->i_data); 568 if (!inode->i_nlink) { 569 inode->i_size = 0; 570 fat_truncate_blocks(inode, 0); 571 } 572 invalidate_inode_buffers(inode); 573 clear_inode(inode); 574 fat_cache_inval_inode(inode); 575 fat_detach(inode); 576 } 577 578 static void fat_set_state(struct super_block *sb, 579 unsigned int set, unsigned int force) 580 { 581 struct buffer_head *bh; 582 struct fat_boot_sector *b; 583 struct msdos_sb_info *sbi = sb->s_fs_info; 584 585 /* do not change any thing if mounted read only */ 586 if ((sb->s_flags & MS_RDONLY) && !force) 587 return; 588 589 /* do not change state if fs was dirty */ 590 if (sbi->dirty) { 591 /* warn only on set (mount). */ 592 if (set) 593 fat_msg(sb, KERN_WARNING, "Volume was not properly " 594 "unmounted. Some data may be corrupt. " 595 "Please run fsck."); 596 return; 597 } 598 599 bh = sb_bread(sb, 0); 600 if (bh == NULL) { 601 fat_msg(sb, KERN_ERR, "unable to read boot sector " 602 "to mark fs as dirty"); 603 return; 604 } 605 606 b = (struct fat_boot_sector *) bh->b_data; 607 608 if (sbi->fat_bits == 32) { 609 if (set) 610 b->fat32.state |= FAT_STATE_DIRTY; 611 else 612 b->fat32.state &= ~FAT_STATE_DIRTY; 613 } else /* fat 16 and 12 */ { 614 if (set) 615 b->fat16.state |= FAT_STATE_DIRTY; 616 else 617 b->fat16.state &= ~FAT_STATE_DIRTY; 618 } 619 620 mark_buffer_dirty(bh); 621 sync_dirty_buffer(bh); 622 brelse(bh); 623 } 624 625 static void delayed_free(struct rcu_head *p) 626 { 627 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 628 unload_nls(sbi->nls_disk); 629 unload_nls(sbi->nls_io); 630 if (sbi->options.iocharset != fat_default_iocharset) 631 kfree(sbi->options.iocharset); 632 kfree(sbi); 633 } 634 635 static void fat_put_super(struct super_block *sb) 636 { 637 struct msdos_sb_info *sbi = MSDOS_SB(sb); 638 639 fat_set_state(sb, 0, 0); 640 641 iput(sbi->fsinfo_inode); 642 iput(sbi->fat_inode); 643 644 call_rcu(&sbi->rcu, delayed_free); 645 } 646 647 static struct kmem_cache *fat_inode_cachep; 648 649 static struct inode *fat_alloc_inode(struct super_block *sb) 650 { 651 struct msdos_inode_info *ei; 652 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 653 if (!ei) 654 return NULL; 655 656 init_rwsem(&ei->truncate_lock); 657 return &ei->vfs_inode; 658 } 659 660 static void fat_i_callback(struct rcu_head *head) 661 { 662 struct inode *inode = container_of(head, struct inode, i_rcu); 663 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 664 } 665 666 static void fat_destroy_inode(struct inode *inode) 667 { 668 call_rcu(&inode->i_rcu, fat_i_callback); 669 } 670 671 static void init_once(void *foo) 672 { 673 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 674 675 spin_lock_init(&ei->cache_lru_lock); 676 ei->nr_caches = 0; 677 ei->cache_valid_id = FAT_CACHE_VALID + 1; 678 INIT_LIST_HEAD(&ei->cache_lru); 679 INIT_HLIST_NODE(&ei->i_fat_hash); 680 INIT_HLIST_NODE(&ei->i_dir_hash); 681 inode_init_once(&ei->vfs_inode); 682 } 683 684 static int __init fat_init_inodecache(void) 685 { 686 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 687 sizeof(struct msdos_inode_info), 688 0, (SLAB_RECLAIM_ACCOUNT| 689 SLAB_MEM_SPREAD), 690 init_once); 691 if (fat_inode_cachep == NULL) 692 return -ENOMEM; 693 return 0; 694 } 695 696 static void __exit fat_destroy_inodecache(void) 697 { 698 /* 699 * Make sure all delayed rcu free inodes are flushed before we 700 * destroy cache. 701 */ 702 rcu_barrier(); 703 kmem_cache_destroy(fat_inode_cachep); 704 } 705 706 static int fat_remount(struct super_block *sb, int *flags, char *data) 707 { 708 int new_rdonly; 709 struct msdos_sb_info *sbi = MSDOS_SB(sb); 710 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME); 711 712 sync_filesystem(sb); 713 714 /* make sure we update state on remount. */ 715 new_rdonly = *flags & MS_RDONLY; 716 if (new_rdonly != (sb->s_flags & MS_RDONLY)) { 717 if (new_rdonly) 718 fat_set_state(sb, 0, 0); 719 else 720 fat_set_state(sb, 1, 1); 721 } 722 return 0; 723 } 724 725 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 726 { 727 struct super_block *sb = dentry->d_sb; 728 struct msdos_sb_info *sbi = MSDOS_SB(sb); 729 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 730 731 /* If the count of free cluster is still unknown, counts it here. */ 732 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 733 int err = fat_count_free_clusters(dentry->d_sb); 734 if (err) 735 return err; 736 } 737 738 buf->f_type = dentry->d_sb->s_magic; 739 buf->f_bsize = sbi->cluster_size; 740 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 741 buf->f_bfree = sbi->free_clusters; 742 buf->f_bavail = sbi->free_clusters; 743 buf->f_fsid.val[0] = (u32)id; 744 buf->f_fsid.val[1] = (u32)(id >> 32); 745 buf->f_namelen = 746 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 747 748 return 0; 749 } 750 751 static int __fat_write_inode(struct inode *inode, int wait) 752 { 753 struct super_block *sb = inode->i_sb; 754 struct msdos_sb_info *sbi = MSDOS_SB(sb); 755 struct buffer_head *bh; 756 struct msdos_dir_entry *raw_entry; 757 loff_t i_pos; 758 sector_t blocknr; 759 int err, offset; 760 761 if (inode->i_ino == MSDOS_ROOT_INO) 762 return 0; 763 764 retry: 765 i_pos = fat_i_pos_read(sbi, inode); 766 if (!i_pos) 767 return 0; 768 769 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 770 bh = sb_bread(sb, blocknr); 771 if (!bh) { 772 fat_msg(sb, KERN_ERR, "unable to read inode block " 773 "for updating (i_pos %lld)", i_pos); 774 return -EIO; 775 } 776 spin_lock(&sbi->inode_hash_lock); 777 if (i_pos != MSDOS_I(inode)->i_pos) { 778 spin_unlock(&sbi->inode_hash_lock); 779 brelse(bh); 780 goto retry; 781 } 782 783 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 784 if (S_ISDIR(inode->i_mode)) 785 raw_entry->size = 0; 786 else 787 raw_entry->size = cpu_to_le32(inode->i_size); 788 raw_entry->attr = fat_make_attrs(inode); 789 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 790 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 791 &raw_entry->date, NULL); 792 if (sbi->options.isvfat) { 793 __le16 atime; 794 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 795 &raw_entry->cdate, &raw_entry->ctime_cs); 796 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 797 &raw_entry->adate, NULL); 798 } 799 spin_unlock(&sbi->inode_hash_lock); 800 mark_buffer_dirty(bh); 801 err = 0; 802 if (wait) 803 err = sync_dirty_buffer(bh); 804 brelse(bh); 805 return err; 806 } 807 808 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 809 { 810 int err; 811 812 if (inode->i_ino == MSDOS_FSINFO_INO) { 813 struct super_block *sb = inode->i_sb; 814 815 mutex_lock(&MSDOS_SB(sb)->s_lock); 816 err = fat_clusters_flush(sb); 817 mutex_unlock(&MSDOS_SB(sb)->s_lock); 818 } else 819 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 820 821 return err; 822 } 823 824 int fat_sync_inode(struct inode *inode) 825 { 826 return __fat_write_inode(inode, 1); 827 } 828 829 EXPORT_SYMBOL_GPL(fat_sync_inode); 830 831 static int fat_show_options(struct seq_file *m, struct dentry *root); 832 static const struct super_operations fat_sops = { 833 .alloc_inode = fat_alloc_inode, 834 .destroy_inode = fat_destroy_inode, 835 .write_inode = fat_write_inode, 836 .evict_inode = fat_evict_inode, 837 .put_super = fat_put_super, 838 .statfs = fat_statfs, 839 .remount_fs = fat_remount, 840 841 .show_options = fat_show_options, 842 }; 843 844 static int fat_show_options(struct seq_file *m, struct dentry *root) 845 { 846 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 847 struct fat_mount_options *opts = &sbi->options; 848 int isvfat = opts->isvfat; 849 850 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 851 seq_printf(m, ",uid=%u", 852 from_kuid_munged(&init_user_ns, opts->fs_uid)); 853 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 854 seq_printf(m, ",gid=%u", 855 from_kgid_munged(&init_user_ns, opts->fs_gid)); 856 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 857 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 858 if (opts->allow_utime) 859 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 860 if (sbi->nls_disk) 861 /* strip "cp" prefix from displayed option */ 862 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 863 if (isvfat) { 864 if (sbi->nls_io) 865 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 866 867 switch (opts->shortname) { 868 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 869 seq_puts(m, ",shortname=win95"); 870 break; 871 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 872 seq_puts(m, ",shortname=winnt"); 873 break; 874 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 875 seq_puts(m, ",shortname=mixed"); 876 break; 877 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 878 seq_puts(m, ",shortname=lower"); 879 break; 880 default: 881 seq_puts(m, ",shortname=unknown"); 882 break; 883 } 884 } 885 if (opts->name_check != 'n') 886 seq_printf(m, ",check=%c", opts->name_check); 887 if (opts->usefree) 888 seq_puts(m, ",usefree"); 889 if (opts->quiet) 890 seq_puts(m, ",quiet"); 891 if (opts->showexec) 892 seq_puts(m, ",showexec"); 893 if (opts->sys_immutable) 894 seq_puts(m, ",sys_immutable"); 895 if (!isvfat) { 896 if (opts->dotsOK) 897 seq_puts(m, ",dotsOK=yes"); 898 if (opts->nocase) 899 seq_puts(m, ",nocase"); 900 } else { 901 if (opts->utf8) 902 seq_puts(m, ",utf8"); 903 if (opts->unicode_xlate) 904 seq_puts(m, ",uni_xlate"); 905 if (!opts->numtail) 906 seq_puts(m, ",nonumtail"); 907 if (opts->rodir) 908 seq_puts(m, ",rodir"); 909 } 910 if (opts->flush) 911 seq_puts(m, ",flush"); 912 if (opts->tz_set) { 913 if (opts->time_offset) 914 seq_printf(m, ",time_offset=%d", opts->time_offset); 915 else 916 seq_puts(m, ",tz=UTC"); 917 } 918 if (opts->errors == FAT_ERRORS_CONT) 919 seq_puts(m, ",errors=continue"); 920 else if (opts->errors == FAT_ERRORS_PANIC) 921 seq_puts(m, ",errors=panic"); 922 else 923 seq_puts(m, ",errors=remount-ro"); 924 if (opts->nfs == FAT_NFS_NOSTALE_RO) 925 seq_puts(m, ",nfs=nostale_ro"); 926 else if (opts->nfs) 927 seq_puts(m, ",nfs=stale_rw"); 928 if (opts->discard) 929 seq_puts(m, ",discard"); 930 if (opts->dos1xfloppy) 931 seq_puts(m, ",dos1xfloppy"); 932 933 return 0; 934 } 935 936 enum { 937 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 938 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 939 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 940 Opt_immutable, Opt_dots, Opt_nodots, 941 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 942 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 943 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 944 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 945 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 946 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 947 }; 948 949 static const match_table_t fat_tokens = { 950 {Opt_check_r, "check=relaxed"}, 951 {Opt_check_s, "check=strict"}, 952 {Opt_check_n, "check=normal"}, 953 {Opt_check_r, "check=r"}, 954 {Opt_check_s, "check=s"}, 955 {Opt_check_n, "check=n"}, 956 {Opt_uid, "uid=%u"}, 957 {Opt_gid, "gid=%u"}, 958 {Opt_umask, "umask=%o"}, 959 {Opt_dmask, "dmask=%o"}, 960 {Opt_fmask, "fmask=%o"}, 961 {Opt_allow_utime, "allow_utime=%o"}, 962 {Opt_codepage, "codepage=%u"}, 963 {Opt_usefree, "usefree"}, 964 {Opt_nocase, "nocase"}, 965 {Opt_quiet, "quiet"}, 966 {Opt_showexec, "showexec"}, 967 {Opt_debug, "debug"}, 968 {Opt_immutable, "sys_immutable"}, 969 {Opt_flush, "flush"}, 970 {Opt_tz_utc, "tz=UTC"}, 971 {Opt_time_offset, "time_offset=%d"}, 972 {Opt_err_cont, "errors=continue"}, 973 {Opt_err_panic, "errors=panic"}, 974 {Opt_err_ro, "errors=remount-ro"}, 975 {Opt_discard, "discard"}, 976 {Opt_nfs_stale_rw, "nfs"}, 977 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 978 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 979 {Opt_dos1xfloppy, "dos1xfloppy"}, 980 {Opt_obsolete, "conv=binary"}, 981 {Opt_obsolete, "conv=text"}, 982 {Opt_obsolete, "conv=auto"}, 983 {Opt_obsolete, "conv=b"}, 984 {Opt_obsolete, "conv=t"}, 985 {Opt_obsolete, "conv=a"}, 986 {Opt_obsolete, "fat=%u"}, 987 {Opt_obsolete, "blocksize=%u"}, 988 {Opt_obsolete, "cvf_format=%20s"}, 989 {Opt_obsolete, "cvf_options=%100s"}, 990 {Opt_obsolete, "posix"}, 991 {Opt_err, NULL}, 992 }; 993 static const match_table_t msdos_tokens = { 994 {Opt_nodots, "nodots"}, 995 {Opt_nodots, "dotsOK=no"}, 996 {Opt_dots, "dots"}, 997 {Opt_dots, "dotsOK=yes"}, 998 {Opt_err, NULL} 999 }; 1000 static const match_table_t vfat_tokens = { 1001 {Opt_charset, "iocharset=%s"}, 1002 {Opt_shortname_lower, "shortname=lower"}, 1003 {Opt_shortname_win95, "shortname=win95"}, 1004 {Opt_shortname_winnt, "shortname=winnt"}, 1005 {Opt_shortname_mixed, "shortname=mixed"}, 1006 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1007 {Opt_utf8_no, "utf8=no"}, 1008 {Opt_utf8_no, "utf8=false"}, 1009 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1010 {Opt_utf8_yes, "utf8=yes"}, 1011 {Opt_utf8_yes, "utf8=true"}, 1012 {Opt_utf8_yes, "utf8"}, 1013 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1014 {Opt_uni_xl_no, "uni_xlate=no"}, 1015 {Opt_uni_xl_no, "uni_xlate=false"}, 1016 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1017 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1018 {Opt_uni_xl_yes, "uni_xlate=true"}, 1019 {Opt_uni_xl_yes, "uni_xlate"}, 1020 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1021 {Opt_nonumtail_no, "nonumtail=no"}, 1022 {Opt_nonumtail_no, "nonumtail=false"}, 1023 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1024 {Opt_nonumtail_yes, "nonumtail=yes"}, 1025 {Opt_nonumtail_yes, "nonumtail=true"}, 1026 {Opt_nonumtail_yes, "nonumtail"}, 1027 {Opt_rodir, "rodir"}, 1028 {Opt_err, NULL} 1029 }; 1030 1031 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1032 int silent, int *debug, struct fat_mount_options *opts) 1033 { 1034 char *p; 1035 substring_t args[MAX_OPT_ARGS]; 1036 int option; 1037 char *iocharset; 1038 1039 opts->isvfat = is_vfat; 1040 1041 opts->fs_uid = current_uid(); 1042 opts->fs_gid = current_gid(); 1043 opts->fs_fmask = opts->fs_dmask = current_umask(); 1044 opts->allow_utime = -1; 1045 opts->codepage = fat_default_codepage; 1046 opts->iocharset = fat_default_iocharset; 1047 if (is_vfat) { 1048 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1049 opts->rodir = 0; 1050 } else { 1051 opts->shortname = 0; 1052 opts->rodir = 1; 1053 } 1054 opts->name_check = 'n'; 1055 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1056 opts->utf8 = opts->unicode_xlate = 0; 1057 opts->numtail = 1; 1058 opts->usefree = opts->nocase = 0; 1059 opts->tz_set = 0; 1060 opts->nfs = 0; 1061 opts->errors = FAT_ERRORS_RO; 1062 *debug = 0; 1063 1064 if (!options) 1065 goto out; 1066 1067 while ((p = strsep(&options, ",")) != NULL) { 1068 int token; 1069 if (!*p) 1070 continue; 1071 1072 token = match_token(p, fat_tokens, args); 1073 if (token == Opt_err) { 1074 if (is_vfat) 1075 token = match_token(p, vfat_tokens, args); 1076 else 1077 token = match_token(p, msdos_tokens, args); 1078 } 1079 switch (token) { 1080 case Opt_check_s: 1081 opts->name_check = 's'; 1082 break; 1083 case Opt_check_r: 1084 opts->name_check = 'r'; 1085 break; 1086 case Opt_check_n: 1087 opts->name_check = 'n'; 1088 break; 1089 case Opt_usefree: 1090 opts->usefree = 1; 1091 break; 1092 case Opt_nocase: 1093 if (!is_vfat) 1094 opts->nocase = 1; 1095 else { 1096 /* for backward compatibility */ 1097 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1098 | VFAT_SFN_CREATE_WIN95; 1099 } 1100 break; 1101 case Opt_quiet: 1102 opts->quiet = 1; 1103 break; 1104 case Opt_showexec: 1105 opts->showexec = 1; 1106 break; 1107 case Opt_debug: 1108 *debug = 1; 1109 break; 1110 case Opt_immutable: 1111 opts->sys_immutable = 1; 1112 break; 1113 case Opt_uid: 1114 if (match_int(&args[0], &option)) 1115 return -EINVAL; 1116 opts->fs_uid = make_kuid(current_user_ns(), option); 1117 if (!uid_valid(opts->fs_uid)) 1118 return -EINVAL; 1119 break; 1120 case Opt_gid: 1121 if (match_int(&args[0], &option)) 1122 return -EINVAL; 1123 opts->fs_gid = make_kgid(current_user_ns(), option); 1124 if (!gid_valid(opts->fs_gid)) 1125 return -EINVAL; 1126 break; 1127 case Opt_umask: 1128 if (match_octal(&args[0], &option)) 1129 return -EINVAL; 1130 opts->fs_fmask = opts->fs_dmask = option; 1131 break; 1132 case Opt_dmask: 1133 if (match_octal(&args[0], &option)) 1134 return -EINVAL; 1135 opts->fs_dmask = option; 1136 break; 1137 case Opt_fmask: 1138 if (match_octal(&args[0], &option)) 1139 return -EINVAL; 1140 opts->fs_fmask = option; 1141 break; 1142 case Opt_allow_utime: 1143 if (match_octal(&args[0], &option)) 1144 return -EINVAL; 1145 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1146 break; 1147 case Opt_codepage: 1148 if (match_int(&args[0], &option)) 1149 return -EINVAL; 1150 opts->codepage = option; 1151 break; 1152 case Opt_flush: 1153 opts->flush = 1; 1154 break; 1155 case Opt_time_offset: 1156 if (match_int(&args[0], &option)) 1157 return -EINVAL; 1158 if (option < -12 * 60 || option > 12 * 60) 1159 return -EINVAL; 1160 opts->tz_set = 1; 1161 opts->time_offset = option; 1162 break; 1163 case Opt_tz_utc: 1164 opts->tz_set = 1; 1165 opts->time_offset = 0; 1166 break; 1167 case Opt_err_cont: 1168 opts->errors = FAT_ERRORS_CONT; 1169 break; 1170 case Opt_err_panic: 1171 opts->errors = FAT_ERRORS_PANIC; 1172 break; 1173 case Opt_err_ro: 1174 opts->errors = FAT_ERRORS_RO; 1175 break; 1176 case Opt_nfs_stale_rw: 1177 opts->nfs = FAT_NFS_STALE_RW; 1178 break; 1179 case Opt_nfs_nostale_ro: 1180 opts->nfs = FAT_NFS_NOSTALE_RO; 1181 break; 1182 case Opt_dos1xfloppy: 1183 opts->dos1xfloppy = 1; 1184 break; 1185 1186 /* msdos specific */ 1187 case Opt_dots: 1188 opts->dotsOK = 1; 1189 break; 1190 case Opt_nodots: 1191 opts->dotsOK = 0; 1192 break; 1193 1194 /* vfat specific */ 1195 case Opt_charset: 1196 if (opts->iocharset != fat_default_iocharset) 1197 kfree(opts->iocharset); 1198 iocharset = match_strdup(&args[0]); 1199 if (!iocharset) 1200 return -ENOMEM; 1201 opts->iocharset = iocharset; 1202 break; 1203 case Opt_shortname_lower: 1204 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1205 | VFAT_SFN_CREATE_WIN95; 1206 break; 1207 case Opt_shortname_win95: 1208 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1209 | VFAT_SFN_CREATE_WIN95; 1210 break; 1211 case Opt_shortname_winnt: 1212 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1213 | VFAT_SFN_CREATE_WINNT; 1214 break; 1215 case Opt_shortname_mixed: 1216 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1217 | VFAT_SFN_CREATE_WIN95; 1218 break; 1219 case Opt_utf8_no: /* 0 or no or false */ 1220 opts->utf8 = 0; 1221 break; 1222 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1223 opts->utf8 = 1; 1224 break; 1225 case Opt_uni_xl_no: /* 0 or no or false */ 1226 opts->unicode_xlate = 0; 1227 break; 1228 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1229 opts->unicode_xlate = 1; 1230 break; 1231 case Opt_nonumtail_no: /* 0 or no or false */ 1232 opts->numtail = 1; /* negated option */ 1233 break; 1234 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1235 opts->numtail = 0; /* negated option */ 1236 break; 1237 case Opt_rodir: 1238 opts->rodir = 1; 1239 break; 1240 case Opt_discard: 1241 opts->discard = 1; 1242 break; 1243 1244 /* obsolete mount options */ 1245 case Opt_obsolete: 1246 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1247 "not supported now", p); 1248 break; 1249 /* unknown option */ 1250 default: 1251 if (!silent) { 1252 fat_msg(sb, KERN_ERR, 1253 "Unrecognized mount option \"%s\" " 1254 "or missing value", p); 1255 } 1256 return -EINVAL; 1257 } 1258 } 1259 1260 out: 1261 /* UTF-8 doesn't provide FAT semantics */ 1262 if (!strcmp(opts->iocharset, "utf8")) { 1263 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1264 " for FAT filesystems, filesystem will be " 1265 "case sensitive!"); 1266 } 1267 1268 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1269 if (opts->allow_utime == (unsigned short)-1) 1270 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1271 if (opts->unicode_xlate) 1272 opts->utf8 = 0; 1273 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1274 sb->s_flags |= MS_RDONLY; 1275 sb->s_export_op = &fat_export_ops_nostale; 1276 } 1277 1278 return 0; 1279 } 1280 1281 static int fat_read_root(struct inode *inode) 1282 { 1283 struct super_block *sb = inode->i_sb; 1284 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1285 int error; 1286 1287 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1288 inode->i_uid = sbi->options.fs_uid; 1289 inode->i_gid = sbi->options.fs_gid; 1290 inode->i_version++; 1291 inode->i_generation = 0; 1292 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1293 inode->i_op = sbi->dir_ops; 1294 inode->i_fop = &fat_dir_operations; 1295 if (sbi->fat_bits == 32) { 1296 MSDOS_I(inode)->i_start = sbi->root_cluster; 1297 error = fat_calc_dir_size(inode); 1298 if (error < 0) 1299 return error; 1300 } else { 1301 MSDOS_I(inode)->i_start = 0; 1302 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1303 } 1304 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1305 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1306 MSDOS_I(inode)->i_logstart = 0; 1307 MSDOS_I(inode)->mmu_private = inode->i_size; 1308 1309 fat_save_attrs(inode, ATTR_DIR); 1310 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1311 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1312 set_nlink(inode, fat_subdirs(inode)+2); 1313 1314 return 0; 1315 } 1316 1317 static unsigned long calc_fat_clusters(struct super_block *sb) 1318 { 1319 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1320 1321 /* Divide first to avoid overflow */ 1322 if (sbi->fat_bits != 12) { 1323 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1324 return ent_per_sec * sbi->fat_length; 1325 } 1326 1327 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1328 } 1329 1330 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1331 { 1332 if (get_unaligned_le16(&b->sector_size)) 1333 return false; 1334 if (b->sec_per_clus) 1335 return false; 1336 if (b->reserved) 1337 return false; 1338 if (b->fats) 1339 return false; 1340 if (get_unaligned_le16(&b->dir_entries)) 1341 return false; 1342 if (get_unaligned_le16(&b->sectors)) 1343 return false; 1344 if (b->media) 1345 return false; 1346 if (b->fat_length) 1347 return false; 1348 if (b->secs_track) 1349 return false; 1350 if (b->heads) 1351 return false; 1352 return true; 1353 } 1354 1355 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1356 int silent, struct fat_bios_param_block *bpb) 1357 { 1358 int error = -EINVAL; 1359 1360 /* Read in BPB ... */ 1361 memset(bpb, 0, sizeof(*bpb)); 1362 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1363 bpb->fat_sec_per_clus = b->sec_per_clus; 1364 bpb->fat_reserved = le16_to_cpu(b->reserved); 1365 bpb->fat_fats = b->fats; 1366 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1367 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1368 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1369 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1370 1371 bpb->fat16_state = b->fat16.state; 1372 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1373 1374 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1375 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1376 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1377 bpb->fat32_state = b->fat32.state; 1378 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1379 1380 /* Validate this looks like a FAT filesystem BPB */ 1381 if (!bpb->fat_reserved) { 1382 if (!silent) 1383 fat_msg(sb, KERN_ERR, 1384 "bogus number of reserved sectors"); 1385 goto out; 1386 } 1387 if (!bpb->fat_fats) { 1388 if (!silent) 1389 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1390 goto out; 1391 } 1392 1393 /* 1394 * Earlier we checked here that b->secs_track and b->head are nonzero, 1395 * but it turns out valid FAT filesystems can have zero there. 1396 */ 1397 1398 if (!fat_valid_media(b->media)) { 1399 if (!silent) 1400 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1401 (unsigned)b->media); 1402 goto out; 1403 } 1404 1405 if (!is_power_of_2(bpb->fat_sector_size) 1406 || (bpb->fat_sector_size < 512) 1407 || (bpb->fat_sector_size > 4096)) { 1408 if (!silent) 1409 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1410 (unsigned)bpb->fat_sector_size); 1411 goto out; 1412 } 1413 1414 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1415 if (!silent) 1416 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1417 (unsigned)bpb->fat_sec_per_clus); 1418 goto out; 1419 } 1420 1421 error = 0; 1422 1423 out: 1424 return error; 1425 } 1426 1427 static int fat_read_static_bpb(struct super_block *sb, 1428 struct fat_boot_sector *b, int silent, 1429 struct fat_bios_param_block *bpb) 1430 { 1431 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1432 1433 struct fat_floppy_defaults *fdefaults = NULL; 1434 int error = -EINVAL; 1435 sector_t bd_sects; 1436 unsigned i; 1437 1438 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1439 1440 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1441 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1442 if (!silent) 1443 fat_msg(sb, KERN_ERR, 1444 "%s; no bootstrapping code", notdos1x); 1445 goto out; 1446 } 1447 1448 /* 1449 * If any value in this region is non-zero, it isn't archaic 1450 * DOS. 1451 */ 1452 if (!fat_bpb_is_zero(b)) { 1453 if (!silent) 1454 fat_msg(sb, KERN_ERR, 1455 "%s; DOS 2.x BPB is non-zero", notdos1x); 1456 goto out; 1457 } 1458 1459 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1460 if (floppy_defaults[i].nr_sectors == bd_sects) { 1461 fdefaults = &floppy_defaults[i]; 1462 break; 1463 } 1464 } 1465 1466 if (fdefaults == NULL) { 1467 if (!silent) 1468 fat_msg(sb, KERN_WARNING, 1469 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1470 (u64)bd_sects); 1471 goto out; 1472 } 1473 1474 if (!silent) 1475 fat_msg(sb, KERN_INFO, 1476 "This looks like a DOS 1.x volume; assuming default BPB values"); 1477 1478 memset(bpb, 0, sizeof(*bpb)); 1479 bpb->fat_sector_size = SECTOR_SIZE; 1480 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1481 bpb->fat_reserved = 1; 1482 bpb->fat_fats = 2; 1483 bpb->fat_dir_entries = fdefaults->dir_entries; 1484 bpb->fat_sectors = fdefaults->nr_sectors; 1485 bpb->fat_fat_length = fdefaults->fat_length; 1486 1487 error = 0; 1488 1489 out: 1490 return error; 1491 } 1492 1493 /* 1494 * Read the super block of an MS-DOS FS. 1495 */ 1496 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1497 void (*setup)(struct super_block *)) 1498 { 1499 struct inode *root_inode = NULL, *fat_inode = NULL; 1500 struct inode *fsinfo_inode = NULL; 1501 struct buffer_head *bh; 1502 struct fat_bios_param_block bpb; 1503 struct msdos_sb_info *sbi; 1504 u16 logical_sector_size; 1505 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1506 int debug; 1507 long error; 1508 char buf[50]; 1509 1510 /* 1511 * GFP_KERNEL is ok here, because while we do hold the 1512 * supeblock lock, memory pressure can't call back into 1513 * the filesystem, since we're only just about to mount 1514 * it and have no inodes etc active! 1515 */ 1516 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1517 if (!sbi) 1518 return -ENOMEM; 1519 sb->s_fs_info = sbi; 1520 1521 sb->s_flags |= MS_NODIRATIME; 1522 sb->s_magic = MSDOS_SUPER_MAGIC; 1523 sb->s_op = &fat_sops; 1524 sb->s_export_op = &fat_export_ops; 1525 mutex_init(&sbi->nfs_build_inode_lock); 1526 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1527 DEFAULT_RATELIMIT_BURST); 1528 1529 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1530 if (error) 1531 goto out_fail; 1532 1533 setup(sb); /* flavour-specific stuff that needs options */ 1534 1535 error = -EIO; 1536 sb_min_blocksize(sb, 512); 1537 bh = sb_bread(sb, 0); 1538 if (bh == NULL) { 1539 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1540 goto out_fail; 1541 } 1542 1543 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1544 &bpb); 1545 if (error == -EINVAL && sbi->options.dos1xfloppy) 1546 error = fat_read_static_bpb(sb, 1547 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1548 brelse(bh); 1549 1550 if (error == -EINVAL) 1551 goto out_invalid; 1552 else if (error) 1553 goto out_fail; 1554 1555 logical_sector_size = bpb.fat_sector_size; 1556 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1557 1558 error = -EIO; 1559 if (logical_sector_size < sb->s_blocksize) { 1560 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1561 " (logical sector size = %u)", logical_sector_size); 1562 goto out_fail; 1563 } 1564 1565 if (logical_sector_size > sb->s_blocksize) { 1566 struct buffer_head *bh_resize; 1567 1568 if (!sb_set_blocksize(sb, logical_sector_size)) { 1569 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1570 logical_sector_size); 1571 goto out_fail; 1572 } 1573 1574 /* Verify that the larger boot sector is fully readable */ 1575 bh_resize = sb_bread(sb, 0); 1576 if (bh_resize == NULL) { 1577 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1578 " (logical sector size = %lu)", 1579 sb->s_blocksize); 1580 goto out_fail; 1581 } 1582 brelse(bh_resize); 1583 } 1584 1585 mutex_init(&sbi->s_lock); 1586 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1587 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1588 sbi->fats = bpb.fat_fats; 1589 sbi->fat_bits = 0; /* Don't know yet */ 1590 sbi->fat_start = bpb.fat_reserved; 1591 sbi->fat_length = bpb.fat_fat_length; 1592 sbi->root_cluster = 0; 1593 sbi->free_clusters = -1; /* Don't know yet */ 1594 sbi->free_clus_valid = 0; 1595 sbi->prev_free = FAT_START_ENT; 1596 sb->s_maxbytes = 0xffffffff; 1597 1598 if (!sbi->fat_length && bpb.fat32_length) { 1599 struct fat_boot_fsinfo *fsinfo; 1600 struct buffer_head *fsinfo_bh; 1601 1602 /* Must be FAT32 */ 1603 sbi->fat_bits = 32; 1604 sbi->fat_length = bpb.fat32_length; 1605 sbi->root_cluster = bpb.fat32_root_cluster; 1606 1607 /* MC - if info_sector is 0, don't multiply by 0 */ 1608 sbi->fsinfo_sector = bpb.fat32_info_sector; 1609 if (sbi->fsinfo_sector == 0) 1610 sbi->fsinfo_sector = 1; 1611 1612 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1613 if (fsinfo_bh == NULL) { 1614 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1615 " (sector = %lu)", sbi->fsinfo_sector); 1616 goto out_fail; 1617 } 1618 1619 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1620 if (!IS_FSINFO(fsinfo)) { 1621 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1622 "0x%08x, 0x%08x (sector = %lu)", 1623 le32_to_cpu(fsinfo->signature1), 1624 le32_to_cpu(fsinfo->signature2), 1625 sbi->fsinfo_sector); 1626 } else { 1627 if (sbi->options.usefree) 1628 sbi->free_clus_valid = 1; 1629 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1630 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1631 } 1632 1633 brelse(fsinfo_bh); 1634 } 1635 1636 /* interpret volume ID as a little endian 32 bit integer */ 1637 if (sbi->fat_bits == 32) 1638 sbi->vol_id = bpb.fat32_vol_id; 1639 else /* fat 16 or 12 */ 1640 sbi->vol_id = bpb.fat16_vol_id; 1641 1642 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1643 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1644 1645 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1646 sbi->dir_entries = bpb.fat_dir_entries; 1647 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1648 if (!silent) 1649 fat_msg(sb, KERN_ERR, "bogus directory-entries per block" 1650 " (%u)", sbi->dir_entries); 1651 goto out_invalid; 1652 } 1653 1654 rootdir_sectors = sbi->dir_entries 1655 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1656 sbi->data_start = sbi->dir_start + rootdir_sectors; 1657 total_sectors = bpb.fat_sectors; 1658 if (total_sectors == 0) 1659 total_sectors = bpb.fat_total_sect; 1660 1661 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1662 1663 if (sbi->fat_bits != 32) 1664 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1665 1666 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1667 if (sbi->fat_bits == 32) 1668 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1669 else /* fat 16 or 12 */ 1670 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1671 1672 /* check that FAT table does not overflow */ 1673 fat_clusters = calc_fat_clusters(sb); 1674 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1675 if (total_clusters > MAX_FAT(sb)) { 1676 if (!silent) 1677 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1678 total_clusters); 1679 goto out_invalid; 1680 } 1681 1682 sbi->max_cluster = total_clusters + FAT_START_ENT; 1683 /* check the free_clusters, it's not necessarily correct */ 1684 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1685 sbi->free_clusters = -1; 1686 /* check the prev_free, it's not necessarily correct */ 1687 sbi->prev_free %= sbi->max_cluster; 1688 if (sbi->prev_free < FAT_START_ENT) 1689 sbi->prev_free = FAT_START_ENT; 1690 1691 /* set up enough so that it can read an inode */ 1692 fat_hash_init(sb); 1693 dir_hash_init(sb); 1694 fat_ent_access_init(sb); 1695 1696 /* 1697 * The low byte of FAT's first entry must have same value with 1698 * media-field. But in real world, too many devices is 1699 * writing wrong value. So, removed that validity check. 1700 * 1701 * if (FAT_FIRST_ENT(sb, media) != first) 1702 */ 1703 1704 error = -EINVAL; 1705 sprintf(buf, "cp%d", sbi->options.codepage); 1706 sbi->nls_disk = load_nls(buf); 1707 if (!sbi->nls_disk) { 1708 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1709 goto out_fail; 1710 } 1711 1712 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1713 if (sbi->options.isvfat) { 1714 sbi->nls_io = load_nls(sbi->options.iocharset); 1715 if (!sbi->nls_io) { 1716 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1717 sbi->options.iocharset); 1718 goto out_fail; 1719 } 1720 } 1721 1722 error = -ENOMEM; 1723 fat_inode = new_inode(sb); 1724 if (!fat_inode) 1725 goto out_fail; 1726 MSDOS_I(fat_inode)->i_pos = 0; 1727 sbi->fat_inode = fat_inode; 1728 1729 fsinfo_inode = new_inode(sb); 1730 if (!fsinfo_inode) 1731 goto out_fail; 1732 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1733 sbi->fsinfo_inode = fsinfo_inode; 1734 insert_inode_hash(fsinfo_inode); 1735 1736 root_inode = new_inode(sb); 1737 if (!root_inode) 1738 goto out_fail; 1739 root_inode->i_ino = MSDOS_ROOT_INO; 1740 root_inode->i_version = 1; 1741 error = fat_read_root(root_inode); 1742 if (error < 0) { 1743 iput(root_inode); 1744 goto out_fail; 1745 } 1746 error = -ENOMEM; 1747 insert_inode_hash(root_inode); 1748 fat_attach(root_inode, 0); 1749 sb->s_root = d_make_root(root_inode); 1750 if (!sb->s_root) { 1751 fat_msg(sb, KERN_ERR, "get root inode failed"); 1752 goto out_fail; 1753 } 1754 1755 if (sbi->options.discard) { 1756 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1757 if (!blk_queue_discard(q)) 1758 fat_msg(sb, KERN_WARNING, 1759 "mounting with \"discard\" option, but " 1760 "the device does not support discard"); 1761 } 1762 1763 fat_set_state(sb, 1, 0); 1764 return 0; 1765 1766 out_invalid: 1767 error = -EINVAL; 1768 if (!silent) 1769 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1770 1771 out_fail: 1772 if (fsinfo_inode) 1773 iput(fsinfo_inode); 1774 if (fat_inode) 1775 iput(fat_inode); 1776 unload_nls(sbi->nls_io); 1777 unload_nls(sbi->nls_disk); 1778 if (sbi->options.iocharset != fat_default_iocharset) 1779 kfree(sbi->options.iocharset); 1780 sb->s_fs_info = NULL; 1781 kfree(sbi); 1782 return error; 1783 } 1784 1785 EXPORT_SYMBOL_GPL(fat_fill_super); 1786 1787 /* 1788 * helper function for fat_flush_inodes. This writes both the inode 1789 * and the file data blocks, waiting for in flight data blocks before 1790 * the start of the call. It does not wait for any io started 1791 * during the call 1792 */ 1793 static int writeback_inode(struct inode *inode) 1794 { 1795 1796 int ret; 1797 1798 /* if we used wait=1, sync_inode_metadata waits for the io for the 1799 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1800 * and filemap_fdatawrite is used for the data blocks 1801 */ 1802 ret = sync_inode_metadata(inode, 0); 1803 if (!ret) 1804 ret = filemap_fdatawrite(inode->i_mapping); 1805 return ret; 1806 } 1807 1808 /* 1809 * write data and metadata corresponding to i1 and i2. The io is 1810 * started but we do not wait for any of it to finish. 1811 * 1812 * filemap_flush is used for the block device, so if there is a dirty 1813 * page for a block already in flight, we will not wait and start the 1814 * io over again 1815 */ 1816 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1817 { 1818 int ret = 0; 1819 if (!MSDOS_SB(sb)->options.flush) 1820 return 0; 1821 if (i1) 1822 ret = writeback_inode(i1); 1823 if (!ret && i2) 1824 ret = writeback_inode(i2); 1825 if (!ret) { 1826 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1827 ret = filemap_flush(mapping); 1828 } 1829 return ret; 1830 } 1831 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1832 1833 static int __init init_fat_fs(void) 1834 { 1835 int err; 1836 1837 err = fat_cache_init(); 1838 if (err) 1839 return err; 1840 1841 err = fat_init_inodecache(); 1842 if (err) 1843 goto failed; 1844 1845 return 0; 1846 1847 failed: 1848 fat_cache_destroy(); 1849 return err; 1850 } 1851 1852 static void __exit exit_fat_fs(void) 1853 { 1854 fat_cache_destroy(); 1855 fat_destroy_inodecache(); 1856 } 1857 1858 module_init(init_fat_fs) 1859 module_exit(exit_fat_fs) 1860 1861 MODULE_LICENSE("GPL"); 1862