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