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/exportfs.h> 22 #include <linux/mount.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, to, 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 hlist_node *_p; 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, _p, 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 static 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 struct inode *fat_build_inode(struct super_block *sb, 449 struct msdos_dir_entry *de, loff_t i_pos) 450 { 451 struct inode *inode; 452 int err; 453 454 inode = fat_iget(sb, i_pos); 455 if (inode) 456 goto out; 457 inode = new_inode(sb); 458 if (!inode) { 459 inode = ERR_PTR(-ENOMEM); 460 goto out; 461 } 462 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 463 inode->i_version = 1; 464 err = fat_fill_inode(inode, de); 465 if (err) { 466 iput(inode); 467 inode = ERR_PTR(err); 468 goto out; 469 } 470 fat_attach(inode, i_pos); 471 insert_inode_hash(inode); 472 out: 473 return inode; 474 } 475 476 EXPORT_SYMBOL_GPL(fat_build_inode); 477 478 static void fat_evict_inode(struct inode *inode) 479 { 480 truncate_inode_pages(&inode->i_data, 0); 481 if (!inode->i_nlink) { 482 inode->i_size = 0; 483 fat_truncate_blocks(inode, 0); 484 } 485 invalidate_inode_buffers(inode); 486 clear_inode(inode); 487 fat_cache_inval_inode(inode); 488 fat_detach(inode); 489 } 490 491 static void fat_set_state(struct super_block *sb, 492 unsigned int set, unsigned int force) 493 { 494 struct buffer_head *bh; 495 struct fat_boot_sector *b; 496 struct msdos_sb_info *sbi = sb->s_fs_info; 497 498 /* do not change any thing if mounted read only */ 499 if ((sb->s_flags & MS_RDONLY) && !force) 500 return; 501 502 /* do not change state if fs was dirty */ 503 if (sbi->dirty) { 504 /* warn only on set (mount). */ 505 if (set) 506 fat_msg(sb, KERN_WARNING, "Volume was not properly " 507 "unmounted. Some data may be corrupt. " 508 "Please run fsck."); 509 return; 510 } 511 512 bh = sb_bread(sb, 0); 513 if (bh == NULL) { 514 fat_msg(sb, KERN_ERR, "unable to read boot sector " 515 "to mark fs as dirty"); 516 return; 517 } 518 519 b = (struct fat_boot_sector *) bh->b_data; 520 521 if (sbi->fat_bits == 32) { 522 if (set) 523 b->fat32.state |= FAT_STATE_DIRTY; 524 else 525 b->fat32.state &= ~FAT_STATE_DIRTY; 526 } else /* fat 16 and 12 */ { 527 if (set) 528 b->fat16.state |= FAT_STATE_DIRTY; 529 else 530 b->fat16.state &= ~FAT_STATE_DIRTY; 531 } 532 533 mark_buffer_dirty(bh); 534 sync_dirty_buffer(bh); 535 brelse(bh); 536 } 537 538 static void fat_put_super(struct super_block *sb) 539 { 540 struct msdos_sb_info *sbi = MSDOS_SB(sb); 541 542 fat_set_state(sb, 0, 0); 543 544 iput(sbi->fsinfo_inode); 545 iput(sbi->fat_inode); 546 547 unload_nls(sbi->nls_disk); 548 unload_nls(sbi->nls_io); 549 550 if (sbi->options.iocharset != fat_default_iocharset) 551 kfree(sbi->options.iocharset); 552 553 sb->s_fs_info = NULL; 554 kfree(sbi); 555 } 556 557 static struct kmem_cache *fat_inode_cachep; 558 559 static struct inode *fat_alloc_inode(struct super_block *sb) 560 { 561 struct msdos_inode_info *ei; 562 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 563 if (!ei) 564 return NULL; 565 566 init_rwsem(&ei->truncate_lock); 567 return &ei->vfs_inode; 568 } 569 570 static void fat_i_callback(struct rcu_head *head) 571 { 572 struct inode *inode = container_of(head, struct inode, i_rcu); 573 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 574 } 575 576 static void fat_destroy_inode(struct inode *inode) 577 { 578 call_rcu(&inode->i_rcu, fat_i_callback); 579 } 580 581 static void init_once(void *foo) 582 { 583 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 584 585 spin_lock_init(&ei->cache_lru_lock); 586 ei->nr_caches = 0; 587 ei->cache_valid_id = FAT_CACHE_VALID + 1; 588 INIT_LIST_HEAD(&ei->cache_lru); 589 INIT_HLIST_NODE(&ei->i_fat_hash); 590 INIT_HLIST_NODE(&ei->i_dir_hash); 591 inode_init_once(&ei->vfs_inode); 592 } 593 594 static int __init fat_init_inodecache(void) 595 { 596 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 597 sizeof(struct msdos_inode_info), 598 0, (SLAB_RECLAIM_ACCOUNT| 599 SLAB_MEM_SPREAD), 600 init_once); 601 if (fat_inode_cachep == NULL) 602 return -ENOMEM; 603 return 0; 604 } 605 606 static void __exit fat_destroy_inodecache(void) 607 { 608 /* 609 * Make sure all delayed rcu free inodes are flushed before we 610 * destroy cache. 611 */ 612 rcu_barrier(); 613 kmem_cache_destroy(fat_inode_cachep); 614 } 615 616 static int fat_remount(struct super_block *sb, int *flags, char *data) 617 { 618 int new_rdonly; 619 struct msdos_sb_info *sbi = MSDOS_SB(sb); 620 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME); 621 622 /* make sure we update state on remount. */ 623 new_rdonly = *flags & MS_RDONLY; 624 if (new_rdonly != (sb->s_flags & MS_RDONLY)) { 625 if (new_rdonly) 626 fat_set_state(sb, 0, 0); 627 else 628 fat_set_state(sb, 1, 1); 629 } 630 return 0; 631 } 632 633 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 634 { 635 struct super_block *sb = dentry->d_sb; 636 struct msdos_sb_info *sbi = MSDOS_SB(sb); 637 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 638 639 /* If the count of free cluster is still unknown, counts it here. */ 640 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 641 int err = fat_count_free_clusters(dentry->d_sb); 642 if (err) 643 return err; 644 } 645 646 buf->f_type = dentry->d_sb->s_magic; 647 buf->f_bsize = sbi->cluster_size; 648 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 649 buf->f_bfree = sbi->free_clusters; 650 buf->f_bavail = sbi->free_clusters; 651 buf->f_fsid.val[0] = (u32)id; 652 buf->f_fsid.val[1] = (u32)(id >> 32); 653 buf->f_namelen = 654 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 655 656 return 0; 657 } 658 659 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, 660 struct inode *inode) 661 { 662 loff_t i_pos; 663 #if BITS_PER_LONG == 32 664 spin_lock(&sbi->inode_hash_lock); 665 #endif 666 i_pos = MSDOS_I(inode)->i_pos; 667 #if BITS_PER_LONG == 32 668 spin_unlock(&sbi->inode_hash_lock); 669 #endif 670 return i_pos; 671 } 672 673 static int __fat_write_inode(struct inode *inode, int wait) 674 { 675 struct super_block *sb = inode->i_sb; 676 struct msdos_sb_info *sbi = MSDOS_SB(sb); 677 struct buffer_head *bh; 678 struct msdos_dir_entry *raw_entry; 679 loff_t i_pos; 680 int err; 681 682 if (inode->i_ino == MSDOS_ROOT_INO) 683 return 0; 684 685 retry: 686 i_pos = fat_i_pos_read(sbi, inode); 687 if (!i_pos) 688 return 0; 689 690 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits); 691 if (!bh) { 692 fat_msg(sb, KERN_ERR, "unable to read inode block " 693 "for updating (i_pos %lld)", i_pos); 694 return -EIO; 695 } 696 spin_lock(&sbi->inode_hash_lock); 697 if (i_pos != MSDOS_I(inode)->i_pos) { 698 spin_unlock(&sbi->inode_hash_lock); 699 brelse(bh); 700 goto retry; 701 } 702 703 raw_entry = &((struct msdos_dir_entry *) (bh->b_data)) 704 [i_pos & (sbi->dir_per_block - 1)]; 705 if (S_ISDIR(inode->i_mode)) 706 raw_entry->size = 0; 707 else 708 raw_entry->size = cpu_to_le32(inode->i_size); 709 raw_entry->attr = fat_make_attrs(inode); 710 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 711 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 712 &raw_entry->date, NULL); 713 if (sbi->options.isvfat) { 714 __le16 atime; 715 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 716 &raw_entry->cdate, &raw_entry->ctime_cs); 717 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 718 &raw_entry->adate, NULL); 719 } 720 spin_unlock(&sbi->inode_hash_lock); 721 mark_buffer_dirty(bh); 722 err = 0; 723 if (wait) 724 err = sync_dirty_buffer(bh); 725 brelse(bh); 726 return err; 727 } 728 729 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 730 { 731 int err; 732 733 if (inode->i_ino == MSDOS_FSINFO_INO) { 734 struct super_block *sb = inode->i_sb; 735 736 mutex_lock(&MSDOS_SB(sb)->s_lock); 737 err = fat_clusters_flush(sb); 738 mutex_unlock(&MSDOS_SB(sb)->s_lock); 739 } else 740 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 741 742 return err; 743 } 744 745 int fat_sync_inode(struct inode *inode) 746 { 747 return __fat_write_inode(inode, 1); 748 } 749 750 EXPORT_SYMBOL_GPL(fat_sync_inode); 751 752 static int fat_show_options(struct seq_file *m, struct dentry *root); 753 static const struct super_operations fat_sops = { 754 .alloc_inode = fat_alloc_inode, 755 .destroy_inode = fat_destroy_inode, 756 .write_inode = fat_write_inode, 757 .evict_inode = fat_evict_inode, 758 .put_super = fat_put_super, 759 .statfs = fat_statfs, 760 .remount_fs = fat_remount, 761 762 .show_options = fat_show_options, 763 }; 764 765 static const struct export_operations fat_export_ops = { 766 .fh_to_dentry = fat_fh_to_dentry, 767 .fh_to_parent = fat_fh_to_parent, 768 .get_parent = fat_get_parent, 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->nfs) 819 seq_puts(m, ",nfs"); 820 if (opts->showexec) 821 seq_puts(m, ",showexec"); 822 if (opts->sys_immutable) 823 seq_puts(m, ",sys_immutable"); 824 if (!isvfat) { 825 if (opts->dotsOK) 826 seq_puts(m, ",dotsOK=yes"); 827 if (opts->nocase) 828 seq_puts(m, ",nocase"); 829 } else { 830 if (opts->utf8) 831 seq_puts(m, ",utf8"); 832 if (opts->unicode_xlate) 833 seq_puts(m, ",uni_xlate"); 834 if (!opts->numtail) 835 seq_puts(m, ",nonumtail"); 836 if (opts->rodir) 837 seq_puts(m, ",rodir"); 838 } 839 if (opts->flush) 840 seq_puts(m, ",flush"); 841 if (opts->tz_set) { 842 if (opts->time_offset) 843 seq_printf(m, ",time_offset=%d", opts->time_offset); 844 else 845 seq_puts(m, ",tz=UTC"); 846 } 847 if (opts->errors == FAT_ERRORS_CONT) 848 seq_puts(m, ",errors=continue"); 849 else if (opts->errors == FAT_ERRORS_PANIC) 850 seq_puts(m, ",errors=panic"); 851 else 852 seq_puts(m, ",errors=remount-ro"); 853 if (opts->discard) 854 seq_puts(m, ",discard"); 855 856 return 0; 857 } 858 859 enum { 860 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 861 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 862 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 863 Opt_immutable, Opt_dots, Opt_nodots, 864 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 865 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 866 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 867 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 868 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 869 Opt_err, 870 }; 871 872 static const match_table_t fat_tokens = { 873 {Opt_check_r, "check=relaxed"}, 874 {Opt_check_s, "check=strict"}, 875 {Opt_check_n, "check=normal"}, 876 {Opt_check_r, "check=r"}, 877 {Opt_check_s, "check=s"}, 878 {Opt_check_n, "check=n"}, 879 {Opt_uid, "uid=%u"}, 880 {Opt_gid, "gid=%u"}, 881 {Opt_umask, "umask=%o"}, 882 {Opt_dmask, "dmask=%o"}, 883 {Opt_fmask, "fmask=%o"}, 884 {Opt_allow_utime, "allow_utime=%o"}, 885 {Opt_codepage, "codepage=%u"}, 886 {Opt_usefree, "usefree"}, 887 {Opt_nocase, "nocase"}, 888 {Opt_quiet, "quiet"}, 889 {Opt_showexec, "showexec"}, 890 {Opt_debug, "debug"}, 891 {Opt_immutable, "sys_immutable"}, 892 {Opt_flush, "flush"}, 893 {Opt_tz_utc, "tz=UTC"}, 894 {Opt_time_offset, "time_offset=%d"}, 895 {Opt_err_cont, "errors=continue"}, 896 {Opt_err_panic, "errors=panic"}, 897 {Opt_err_ro, "errors=remount-ro"}, 898 {Opt_discard, "discard"}, 899 {Opt_nfs, "nfs"}, 900 {Opt_obsolete, "conv=binary"}, 901 {Opt_obsolete, "conv=text"}, 902 {Opt_obsolete, "conv=auto"}, 903 {Opt_obsolete, "conv=b"}, 904 {Opt_obsolete, "conv=t"}, 905 {Opt_obsolete, "conv=a"}, 906 {Opt_obsolete, "fat=%u"}, 907 {Opt_obsolete, "blocksize=%u"}, 908 {Opt_obsolete, "cvf_format=%20s"}, 909 {Opt_obsolete, "cvf_options=%100s"}, 910 {Opt_obsolete, "posix"}, 911 {Opt_err, NULL}, 912 }; 913 static const match_table_t msdos_tokens = { 914 {Opt_nodots, "nodots"}, 915 {Opt_nodots, "dotsOK=no"}, 916 {Opt_dots, "dots"}, 917 {Opt_dots, "dotsOK=yes"}, 918 {Opt_err, NULL} 919 }; 920 static const match_table_t vfat_tokens = { 921 {Opt_charset, "iocharset=%s"}, 922 {Opt_shortname_lower, "shortname=lower"}, 923 {Opt_shortname_win95, "shortname=win95"}, 924 {Opt_shortname_winnt, "shortname=winnt"}, 925 {Opt_shortname_mixed, "shortname=mixed"}, 926 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 927 {Opt_utf8_no, "utf8=no"}, 928 {Opt_utf8_no, "utf8=false"}, 929 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 930 {Opt_utf8_yes, "utf8=yes"}, 931 {Opt_utf8_yes, "utf8=true"}, 932 {Opt_utf8_yes, "utf8"}, 933 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 934 {Opt_uni_xl_no, "uni_xlate=no"}, 935 {Opt_uni_xl_no, "uni_xlate=false"}, 936 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 937 {Opt_uni_xl_yes, "uni_xlate=yes"}, 938 {Opt_uni_xl_yes, "uni_xlate=true"}, 939 {Opt_uni_xl_yes, "uni_xlate"}, 940 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 941 {Opt_nonumtail_no, "nonumtail=no"}, 942 {Opt_nonumtail_no, "nonumtail=false"}, 943 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 944 {Opt_nonumtail_yes, "nonumtail=yes"}, 945 {Opt_nonumtail_yes, "nonumtail=true"}, 946 {Opt_nonumtail_yes, "nonumtail"}, 947 {Opt_rodir, "rodir"}, 948 {Opt_err, NULL} 949 }; 950 951 static int parse_options(struct super_block *sb, char *options, int is_vfat, 952 int silent, int *debug, struct fat_mount_options *opts) 953 { 954 char *p; 955 substring_t args[MAX_OPT_ARGS]; 956 int option; 957 char *iocharset; 958 959 opts->isvfat = is_vfat; 960 961 opts->fs_uid = current_uid(); 962 opts->fs_gid = current_gid(); 963 opts->fs_fmask = opts->fs_dmask = current_umask(); 964 opts->allow_utime = -1; 965 opts->codepage = fat_default_codepage; 966 opts->iocharset = fat_default_iocharset; 967 if (is_vfat) { 968 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 969 opts->rodir = 0; 970 } else { 971 opts->shortname = 0; 972 opts->rodir = 1; 973 } 974 opts->name_check = 'n'; 975 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 976 opts->utf8 = opts->unicode_xlate = 0; 977 opts->numtail = 1; 978 opts->usefree = opts->nocase = 0; 979 opts->tz_set = 0; 980 opts->nfs = 0; 981 opts->errors = FAT_ERRORS_RO; 982 *debug = 0; 983 984 if (!options) 985 goto out; 986 987 while ((p = strsep(&options, ",")) != NULL) { 988 int token; 989 if (!*p) 990 continue; 991 992 token = match_token(p, fat_tokens, args); 993 if (token == Opt_err) { 994 if (is_vfat) 995 token = match_token(p, vfat_tokens, args); 996 else 997 token = match_token(p, msdos_tokens, args); 998 } 999 switch (token) { 1000 case Opt_check_s: 1001 opts->name_check = 's'; 1002 break; 1003 case Opt_check_r: 1004 opts->name_check = 'r'; 1005 break; 1006 case Opt_check_n: 1007 opts->name_check = 'n'; 1008 break; 1009 case Opt_usefree: 1010 opts->usefree = 1; 1011 break; 1012 case Opt_nocase: 1013 if (!is_vfat) 1014 opts->nocase = 1; 1015 else { 1016 /* for backward compatibility */ 1017 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1018 | VFAT_SFN_CREATE_WIN95; 1019 } 1020 break; 1021 case Opt_quiet: 1022 opts->quiet = 1; 1023 break; 1024 case Opt_showexec: 1025 opts->showexec = 1; 1026 break; 1027 case Opt_debug: 1028 *debug = 1; 1029 break; 1030 case Opt_immutable: 1031 opts->sys_immutable = 1; 1032 break; 1033 case Opt_uid: 1034 if (match_int(&args[0], &option)) 1035 return -EINVAL; 1036 opts->fs_uid = make_kuid(current_user_ns(), option); 1037 if (!uid_valid(opts->fs_uid)) 1038 return -EINVAL; 1039 break; 1040 case Opt_gid: 1041 if (match_int(&args[0], &option)) 1042 return -EINVAL; 1043 opts->fs_gid = make_kgid(current_user_ns(), option); 1044 if (!gid_valid(opts->fs_gid)) 1045 return -EINVAL; 1046 break; 1047 case Opt_umask: 1048 if (match_octal(&args[0], &option)) 1049 return -EINVAL; 1050 opts->fs_fmask = opts->fs_dmask = option; 1051 break; 1052 case Opt_dmask: 1053 if (match_octal(&args[0], &option)) 1054 return -EINVAL; 1055 opts->fs_dmask = option; 1056 break; 1057 case Opt_fmask: 1058 if (match_octal(&args[0], &option)) 1059 return -EINVAL; 1060 opts->fs_fmask = option; 1061 break; 1062 case Opt_allow_utime: 1063 if (match_octal(&args[0], &option)) 1064 return -EINVAL; 1065 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1066 break; 1067 case Opt_codepage: 1068 if (match_int(&args[0], &option)) 1069 return -EINVAL; 1070 opts->codepage = option; 1071 break; 1072 case Opt_flush: 1073 opts->flush = 1; 1074 break; 1075 case Opt_time_offset: 1076 if (match_int(&args[0], &option)) 1077 return -EINVAL; 1078 if (option < -12 * 60 || option > 12 * 60) 1079 return -EINVAL; 1080 opts->tz_set = 1; 1081 opts->time_offset = option; 1082 break; 1083 case Opt_tz_utc: 1084 opts->tz_set = 1; 1085 opts->time_offset = 0; 1086 break; 1087 case Opt_err_cont: 1088 opts->errors = FAT_ERRORS_CONT; 1089 break; 1090 case Opt_err_panic: 1091 opts->errors = FAT_ERRORS_PANIC; 1092 break; 1093 case Opt_err_ro: 1094 opts->errors = FAT_ERRORS_RO; 1095 break; 1096 1097 /* msdos specific */ 1098 case Opt_dots: 1099 opts->dotsOK = 1; 1100 break; 1101 case Opt_nodots: 1102 opts->dotsOK = 0; 1103 break; 1104 1105 /* vfat specific */ 1106 case Opt_charset: 1107 if (opts->iocharset != fat_default_iocharset) 1108 kfree(opts->iocharset); 1109 iocharset = match_strdup(&args[0]); 1110 if (!iocharset) 1111 return -ENOMEM; 1112 opts->iocharset = iocharset; 1113 break; 1114 case Opt_shortname_lower: 1115 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1116 | VFAT_SFN_CREATE_WIN95; 1117 break; 1118 case Opt_shortname_win95: 1119 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1120 | VFAT_SFN_CREATE_WIN95; 1121 break; 1122 case Opt_shortname_winnt: 1123 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1124 | VFAT_SFN_CREATE_WINNT; 1125 break; 1126 case Opt_shortname_mixed: 1127 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1128 | VFAT_SFN_CREATE_WIN95; 1129 break; 1130 case Opt_utf8_no: /* 0 or no or false */ 1131 opts->utf8 = 0; 1132 break; 1133 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1134 opts->utf8 = 1; 1135 break; 1136 case Opt_uni_xl_no: /* 0 or no or false */ 1137 opts->unicode_xlate = 0; 1138 break; 1139 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1140 opts->unicode_xlate = 1; 1141 break; 1142 case Opt_nonumtail_no: /* 0 or no or false */ 1143 opts->numtail = 1; /* negated option */ 1144 break; 1145 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1146 opts->numtail = 0; /* negated option */ 1147 break; 1148 case Opt_rodir: 1149 opts->rodir = 1; 1150 break; 1151 case Opt_discard: 1152 opts->discard = 1; 1153 break; 1154 case Opt_nfs: 1155 opts->nfs = 1; 1156 break; 1157 1158 /* obsolete mount options */ 1159 case Opt_obsolete: 1160 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1161 "not supported now", p); 1162 break; 1163 /* unknown option */ 1164 default: 1165 if (!silent) { 1166 fat_msg(sb, KERN_ERR, 1167 "Unrecognized mount option \"%s\" " 1168 "or missing value", p); 1169 } 1170 return -EINVAL; 1171 } 1172 } 1173 1174 out: 1175 /* UTF-8 doesn't provide FAT semantics */ 1176 if (!strcmp(opts->iocharset, "utf8")) { 1177 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1178 " for FAT filesystems, filesystem will be " 1179 "case sensitive!"); 1180 } 1181 1182 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1183 if (opts->allow_utime == (unsigned short)-1) 1184 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1185 if (opts->unicode_xlate) 1186 opts->utf8 = 0; 1187 1188 return 0; 1189 } 1190 1191 static int fat_read_root(struct inode *inode) 1192 { 1193 struct super_block *sb = inode->i_sb; 1194 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1195 int error; 1196 1197 MSDOS_I(inode)->i_pos = 0; 1198 inode->i_uid = sbi->options.fs_uid; 1199 inode->i_gid = sbi->options.fs_gid; 1200 inode->i_version++; 1201 inode->i_generation = 0; 1202 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1203 inode->i_op = sbi->dir_ops; 1204 inode->i_fop = &fat_dir_operations; 1205 if (sbi->fat_bits == 32) { 1206 MSDOS_I(inode)->i_start = sbi->root_cluster; 1207 error = fat_calc_dir_size(inode); 1208 if (error < 0) 1209 return error; 1210 } else { 1211 MSDOS_I(inode)->i_start = 0; 1212 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1213 } 1214 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1215 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1216 MSDOS_I(inode)->i_logstart = 0; 1217 MSDOS_I(inode)->mmu_private = inode->i_size; 1218 1219 fat_save_attrs(inode, ATTR_DIR); 1220 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1221 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1222 set_nlink(inode, fat_subdirs(inode)+2); 1223 1224 return 0; 1225 } 1226 1227 /* 1228 * Read the super block of an MS-DOS FS. 1229 */ 1230 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1231 void (*setup)(struct super_block *)) 1232 { 1233 struct inode *root_inode = NULL, *fat_inode = NULL; 1234 struct inode *fsinfo_inode = NULL; 1235 struct buffer_head *bh; 1236 struct fat_boot_sector *b; 1237 struct msdos_sb_info *sbi; 1238 u16 logical_sector_size; 1239 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1240 int debug; 1241 unsigned int media; 1242 long error; 1243 char buf[50]; 1244 1245 /* 1246 * GFP_KERNEL is ok here, because while we do hold the 1247 * supeblock lock, memory pressure can't call back into 1248 * the filesystem, since we're only just about to mount 1249 * it and have no inodes etc active! 1250 */ 1251 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1252 if (!sbi) 1253 return -ENOMEM; 1254 sb->s_fs_info = sbi; 1255 1256 sb->s_flags |= MS_NODIRATIME; 1257 sb->s_magic = MSDOS_SUPER_MAGIC; 1258 sb->s_op = &fat_sops; 1259 sb->s_export_op = &fat_export_ops; 1260 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1261 DEFAULT_RATELIMIT_BURST); 1262 1263 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1264 if (error) 1265 goto out_fail; 1266 1267 setup(sb); /* flavour-specific stuff that needs options */ 1268 1269 error = -EIO; 1270 sb_min_blocksize(sb, 512); 1271 bh = sb_bread(sb, 0); 1272 if (bh == NULL) { 1273 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1274 goto out_fail; 1275 } 1276 1277 b = (struct fat_boot_sector *) bh->b_data; 1278 if (!b->reserved) { 1279 if (!silent) 1280 fat_msg(sb, KERN_ERR, "bogus number of reserved sectors"); 1281 brelse(bh); 1282 goto out_invalid; 1283 } 1284 if (!b->fats) { 1285 if (!silent) 1286 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1287 brelse(bh); 1288 goto out_invalid; 1289 } 1290 1291 /* 1292 * Earlier we checked here that b->secs_track and b->head are nonzero, 1293 * but it turns out valid FAT filesystems can have zero there. 1294 */ 1295 1296 media = b->media; 1297 if (!fat_valid_media(media)) { 1298 if (!silent) 1299 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1300 media); 1301 brelse(bh); 1302 goto out_invalid; 1303 } 1304 logical_sector_size = get_unaligned_le16(&b->sector_size); 1305 if (!is_power_of_2(logical_sector_size) 1306 || (logical_sector_size < 512) 1307 || (logical_sector_size > 4096)) { 1308 if (!silent) 1309 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1310 logical_sector_size); 1311 brelse(bh); 1312 goto out_invalid; 1313 } 1314 sbi->sec_per_clus = b->sec_per_clus; 1315 if (!is_power_of_2(sbi->sec_per_clus)) { 1316 if (!silent) 1317 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1318 sbi->sec_per_clus); 1319 brelse(bh); 1320 goto out_invalid; 1321 } 1322 1323 if (logical_sector_size < sb->s_blocksize) { 1324 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1325 " (logical sector size = %u)", logical_sector_size); 1326 brelse(bh); 1327 goto out_fail; 1328 } 1329 if (logical_sector_size > sb->s_blocksize) { 1330 brelse(bh); 1331 1332 if (!sb_set_blocksize(sb, logical_sector_size)) { 1333 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1334 logical_sector_size); 1335 goto out_fail; 1336 } 1337 bh = sb_bread(sb, 0); 1338 if (bh == NULL) { 1339 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1340 " (logical sector size = %lu)", 1341 sb->s_blocksize); 1342 goto out_fail; 1343 } 1344 b = (struct fat_boot_sector *) bh->b_data; 1345 } 1346 1347 mutex_init(&sbi->s_lock); 1348 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1349 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1350 sbi->fats = b->fats; 1351 sbi->fat_bits = 0; /* Don't know yet */ 1352 sbi->fat_start = le16_to_cpu(b->reserved); 1353 sbi->fat_length = le16_to_cpu(b->fat_length); 1354 sbi->root_cluster = 0; 1355 sbi->free_clusters = -1; /* Don't know yet */ 1356 sbi->free_clus_valid = 0; 1357 sbi->prev_free = FAT_START_ENT; 1358 sb->s_maxbytes = 0xffffffff; 1359 1360 if (!sbi->fat_length && b->fat32.length) { 1361 struct fat_boot_fsinfo *fsinfo; 1362 struct buffer_head *fsinfo_bh; 1363 1364 /* Must be FAT32 */ 1365 sbi->fat_bits = 32; 1366 sbi->fat_length = le32_to_cpu(b->fat32.length); 1367 sbi->root_cluster = le32_to_cpu(b->fat32.root_cluster); 1368 1369 /* MC - if info_sector is 0, don't multiply by 0 */ 1370 sbi->fsinfo_sector = le16_to_cpu(b->fat32.info_sector); 1371 if (sbi->fsinfo_sector == 0) 1372 sbi->fsinfo_sector = 1; 1373 1374 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1375 if (fsinfo_bh == NULL) { 1376 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1377 " (sector = %lu)", sbi->fsinfo_sector); 1378 brelse(bh); 1379 goto out_fail; 1380 } 1381 1382 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1383 if (!IS_FSINFO(fsinfo)) { 1384 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1385 "0x%08x, 0x%08x (sector = %lu)", 1386 le32_to_cpu(fsinfo->signature1), 1387 le32_to_cpu(fsinfo->signature2), 1388 sbi->fsinfo_sector); 1389 } else { 1390 if (sbi->options.usefree) 1391 sbi->free_clus_valid = 1; 1392 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1393 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1394 } 1395 1396 brelse(fsinfo_bh); 1397 } 1398 1399 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1400 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1401 1402 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1403 sbi->dir_entries = get_unaligned_le16(&b->dir_entries); 1404 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1405 if (!silent) 1406 fat_msg(sb, KERN_ERR, "bogus directory-entries per block" 1407 " (%u)", sbi->dir_entries); 1408 brelse(bh); 1409 goto out_invalid; 1410 } 1411 1412 rootdir_sectors = sbi->dir_entries 1413 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1414 sbi->data_start = sbi->dir_start + rootdir_sectors; 1415 total_sectors = get_unaligned_le16(&b->sectors); 1416 if (total_sectors == 0) 1417 total_sectors = le32_to_cpu(b->total_sect); 1418 1419 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1420 1421 if (sbi->fat_bits != 32) 1422 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1423 1424 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1425 if (sbi->fat_bits == 32) 1426 sbi->dirty = b->fat32.state & FAT_STATE_DIRTY; 1427 else /* fat 16 or 12 */ 1428 sbi->dirty = b->fat16.state & FAT_STATE_DIRTY; 1429 1430 /* check that FAT table does not overflow */ 1431 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1432 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1433 if (total_clusters > MAX_FAT(sb)) { 1434 if (!silent) 1435 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1436 total_clusters); 1437 brelse(bh); 1438 goto out_invalid; 1439 } 1440 1441 sbi->max_cluster = total_clusters + FAT_START_ENT; 1442 /* check the free_clusters, it's not necessarily correct */ 1443 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1444 sbi->free_clusters = -1; 1445 /* check the prev_free, it's not necessarily correct */ 1446 sbi->prev_free %= sbi->max_cluster; 1447 if (sbi->prev_free < FAT_START_ENT) 1448 sbi->prev_free = FAT_START_ENT; 1449 1450 brelse(bh); 1451 1452 /* set up enough so that it can read an inode */ 1453 fat_hash_init(sb); 1454 dir_hash_init(sb); 1455 fat_ent_access_init(sb); 1456 1457 /* 1458 * The low byte of FAT's first entry must have same value with 1459 * media-field. But in real world, too many devices is 1460 * writing wrong value. So, removed that validity check. 1461 * 1462 * if (FAT_FIRST_ENT(sb, media) != first) 1463 */ 1464 1465 error = -EINVAL; 1466 sprintf(buf, "cp%d", sbi->options.codepage); 1467 sbi->nls_disk = load_nls(buf); 1468 if (!sbi->nls_disk) { 1469 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1470 goto out_fail; 1471 } 1472 1473 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1474 if (sbi->options.isvfat) { 1475 sbi->nls_io = load_nls(sbi->options.iocharset); 1476 if (!sbi->nls_io) { 1477 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1478 sbi->options.iocharset); 1479 goto out_fail; 1480 } 1481 } 1482 1483 error = -ENOMEM; 1484 fat_inode = new_inode(sb); 1485 if (!fat_inode) 1486 goto out_fail; 1487 MSDOS_I(fat_inode)->i_pos = 0; 1488 sbi->fat_inode = fat_inode; 1489 1490 fsinfo_inode = new_inode(sb); 1491 if (!fsinfo_inode) 1492 goto out_fail; 1493 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1494 sbi->fsinfo_inode = fsinfo_inode; 1495 insert_inode_hash(fsinfo_inode); 1496 1497 root_inode = new_inode(sb); 1498 if (!root_inode) 1499 goto out_fail; 1500 root_inode->i_ino = MSDOS_ROOT_INO; 1501 root_inode->i_version = 1; 1502 error = fat_read_root(root_inode); 1503 if (error < 0) { 1504 iput(root_inode); 1505 goto out_fail; 1506 } 1507 error = -ENOMEM; 1508 insert_inode_hash(root_inode); 1509 fat_attach(root_inode, 0); 1510 sb->s_root = d_make_root(root_inode); 1511 if (!sb->s_root) { 1512 fat_msg(sb, KERN_ERR, "get root inode failed"); 1513 goto out_fail; 1514 } 1515 1516 if (sbi->options.discard) { 1517 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1518 if (!blk_queue_discard(q)) 1519 fat_msg(sb, KERN_WARNING, 1520 "mounting with \"discard\" option, but " 1521 "the device does not support discard"); 1522 } 1523 1524 fat_set_state(sb, 1, 0); 1525 return 0; 1526 1527 out_invalid: 1528 error = -EINVAL; 1529 if (!silent) 1530 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1531 1532 out_fail: 1533 if (fsinfo_inode) 1534 iput(fsinfo_inode); 1535 if (fat_inode) 1536 iput(fat_inode); 1537 unload_nls(sbi->nls_io); 1538 unload_nls(sbi->nls_disk); 1539 if (sbi->options.iocharset != fat_default_iocharset) 1540 kfree(sbi->options.iocharset); 1541 sb->s_fs_info = NULL; 1542 kfree(sbi); 1543 return error; 1544 } 1545 1546 EXPORT_SYMBOL_GPL(fat_fill_super); 1547 1548 /* 1549 * helper function for fat_flush_inodes. This writes both the inode 1550 * and the file data blocks, waiting for in flight data blocks before 1551 * the start of the call. It does not wait for any io started 1552 * during the call 1553 */ 1554 static int writeback_inode(struct inode *inode) 1555 { 1556 1557 int ret; 1558 1559 /* if we used wait=1, sync_inode_metadata waits for the io for the 1560 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1561 * and filemap_fdatawrite is used for the data blocks 1562 */ 1563 ret = sync_inode_metadata(inode, 0); 1564 if (!ret) 1565 ret = filemap_fdatawrite(inode->i_mapping); 1566 return ret; 1567 } 1568 1569 /* 1570 * write data and metadata corresponding to i1 and i2. The io is 1571 * started but we do not wait for any of it to finish. 1572 * 1573 * filemap_flush is used for the block device, so if there is a dirty 1574 * page for a block already in flight, we will not wait and start the 1575 * io over again 1576 */ 1577 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1578 { 1579 int ret = 0; 1580 if (!MSDOS_SB(sb)->options.flush) 1581 return 0; 1582 if (i1) 1583 ret = writeback_inode(i1); 1584 if (!ret && i2) 1585 ret = writeback_inode(i2); 1586 if (!ret) { 1587 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1588 ret = filemap_flush(mapping); 1589 } 1590 return ret; 1591 } 1592 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1593 1594 static int __init init_fat_fs(void) 1595 { 1596 int err; 1597 1598 err = fat_cache_init(); 1599 if (err) 1600 return err; 1601 1602 err = fat_init_inodecache(); 1603 if (err) 1604 goto failed; 1605 1606 return 0; 1607 1608 failed: 1609 fat_cache_destroy(); 1610 return err; 1611 } 1612 1613 static void __exit exit_fat_fs(void) 1614 { 1615 fat_cache_destroy(); 1616 fat_destroy_inodecache(); 1617 } 1618 1619 module_init(init_fat_fs) 1620 module_exit(exit_fat_fs) 1621 1622 MODULE_LICENSE("GPL"); 1623