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