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_put_super(struct super_block *sb) 492 { 493 struct msdos_sb_info *sbi = MSDOS_SB(sb); 494 495 iput(sbi->fsinfo_inode); 496 iput(sbi->fat_inode); 497 498 unload_nls(sbi->nls_disk); 499 unload_nls(sbi->nls_io); 500 501 if (sbi->options.iocharset != fat_default_iocharset) 502 kfree(sbi->options.iocharset); 503 504 sb->s_fs_info = NULL; 505 kfree(sbi); 506 } 507 508 static struct kmem_cache *fat_inode_cachep; 509 510 static struct inode *fat_alloc_inode(struct super_block *sb) 511 { 512 struct msdos_inode_info *ei; 513 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 514 if (!ei) 515 return NULL; 516 517 init_rwsem(&ei->truncate_lock); 518 return &ei->vfs_inode; 519 } 520 521 static void fat_i_callback(struct rcu_head *head) 522 { 523 struct inode *inode = container_of(head, struct inode, i_rcu); 524 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 525 } 526 527 static void fat_destroy_inode(struct inode *inode) 528 { 529 call_rcu(&inode->i_rcu, fat_i_callback); 530 } 531 532 static void init_once(void *foo) 533 { 534 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 535 536 spin_lock_init(&ei->cache_lru_lock); 537 ei->nr_caches = 0; 538 ei->cache_valid_id = FAT_CACHE_VALID + 1; 539 INIT_LIST_HEAD(&ei->cache_lru); 540 INIT_HLIST_NODE(&ei->i_fat_hash); 541 INIT_HLIST_NODE(&ei->i_dir_hash); 542 inode_init_once(&ei->vfs_inode); 543 } 544 545 static int __init fat_init_inodecache(void) 546 { 547 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 548 sizeof(struct msdos_inode_info), 549 0, (SLAB_RECLAIM_ACCOUNT| 550 SLAB_MEM_SPREAD), 551 init_once); 552 if (fat_inode_cachep == NULL) 553 return -ENOMEM; 554 return 0; 555 } 556 557 static void __exit fat_destroy_inodecache(void) 558 { 559 /* 560 * Make sure all delayed rcu free inodes are flushed before we 561 * destroy cache. 562 */ 563 rcu_barrier(); 564 kmem_cache_destroy(fat_inode_cachep); 565 } 566 567 static int fat_remount(struct super_block *sb, int *flags, char *data) 568 { 569 struct msdos_sb_info *sbi = MSDOS_SB(sb); 570 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME); 571 return 0; 572 } 573 574 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 575 { 576 struct super_block *sb = dentry->d_sb; 577 struct msdos_sb_info *sbi = MSDOS_SB(sb); 578 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 579 580 /* If the count of free cluster is still unknown, counts it here. */ 581 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 582 int err = fat_count_free_clusters(dentry->d_sb); 583 if (err) 584 return err; 585 } 586 587 buf->f_type = dentry->d_sb->s_magic; 588 buf->f_bsize = sbi->cluster_size; 589 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 590 buf->f_bfree = sbi->free_clusters; 591 buf->f_bavail = sbi->free_clusters; 592 buf->f_fsid.val[0] = (u32)id; 593 buf->f_fsid.val[1] = (u32)(id >> 32); 594 buf->f_namelen = 595 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 596 597 return 0; 598 } 599 600 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, 601 struct inode *inode) 602 { 603 loff_t i_pos; 604 #if BITS_PER_LONG == 32 605 spin_lock(&sbi->inode_hash_lock); 606 #endif 607 i_pos = MSDOS_I(inode)->i_pos; 608 #if BITS_PER_LONG == 32 609 spin_unlock(&sbi->inode_hash_lock); 610 #endif 611 return i_pos; 612 } 613 614 static int __fat_write_inode(struct inode *inode, int wait) 615 { 616 struct super_block *sb = inode->i_sb; 617 struct msdos_sb_info *sbi = MSDOS_SB(sb); 618 struct buffer_head *bh; 619 struct msdos_dir_entry *raw_entry; 620 loff_t i_pos; 621 int err; 622 623 if (inode->i_ino == MSDOS_ROOT_INO) 624 return 0; 625 626 retry: 627 i_pos = fat_i_pos_read(sbi, inode); 628 if (!i_pos) 629 return 0; 630 631 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits); 632 if (!bh) { 633 fat_msg(sb, KERN_ERR, "unable to read inode block " 634 "for updating (i_pos %lld)", i_pos); 635 return -EIO; 636 } 637 spin_lock(&sbi->inode_hash_lock); 638 if (i_pos != MSDOS_I(inode)->i_pos) { 639 spin_unlock(&sbi->inode_hash_lock); 640 brelse(bh); 641 goto retry; 642 } 643 644 raw_entry = &((struct msdos_dir_entry *) (bh->b_data)) 645 [i_pos & (sbi->dir_per_block - 1)]; 646 if (S_ISDIR(inode->i_mode)) 647 raw_entry->size = 0; 648 else 649 raw_entry->size = cpu_to_le32(inode->i_size); 650 raw_entry->attr = fat_make_attrs(inode); 651 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 652 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 653 &raw_entry->date, NULL); 654 if (sbi->options.isvfat) { 655 __le16 atime; 656 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 657 &raw_entry->cdate, &raw_entry->ctime_cs); 658 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 659 &raw_entry->adate, NULL); 660 } 661 spin_unlock(&sbi->inode_hash_lock); 662 mark_buffer_dirty(bh); 663 err = 0; 664 if (wait) 665 err = sync_dirty_buffer(bh); 666 brelse(bh); 667 return err; 668 } 669 670 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 671 { 672 int err; 673 674 if (inode->i_ino == MSDOS_FSINFO_INO) { 675 struct super_block *sb = inode->i_sb; 676 677 mutex_lock(&MSDOS_SB(sb)->s_lock); 678 err = fat_clusters_flush(sb); 679 mutex_unlock(&MSDOS_SB(sb)->s_lock); 680 } else 681 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 682 683 return err; 684 } 685 686 int fat_sync_inode(struct inode *inode) 687 { 688 return __fat_write_inode(inode, 1); 689 } 690 691 EXPORT_SYMBOL_GPL(fat_sync_inode); 692 693 static int fat_show_options(struct seq_file *m, struct dentry *root); 694 static const struct super_operations fat_sops = { 695 .alloc_inode = fat_alloc_inode, 696 .destroy_inode = fat_destroy_inode, 697 .write_inode = fat_write_inode, 698 .evict_inode = fat_evict_inode, 699 .put_super = fat_put_super, 700 .statfs = fat_statfs, 701 .remount_fs = fat_remount, 702 703 .show_options = fat_show_options, 704 }; 705 706 static const struct export_operations fat_export_ops = { 707 .fh_to_dentry = fat_fh_to_dentry, 708 .fh_to_parent = fat_fh_to_parent, 709 .get_parent = fat_get_parent, 710 }; 711 712 static int fat_show_options(struct seq_file *m, struct dentry *root) 713 { 714 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 715 struct fat_mount_options *opts = &sbi->options; 716 int isvfat = opts->isvfat; 717 718 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 719 seq_printf(m, ",uid=%u", 720 from_kuid_munged(&init_user_ns, opts->fs_uid)); 721 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 722 seq_printf(m, ",gid=%u", 723 from_kgid_munged(&init_user_ns, opts->fs_gid)); 724 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 725 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 726 if (opts->allow_utime) 727 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 728 if (sbi->nls_disk) 729 /* strip "cp" prefix from displayed option */ 730 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 731 if (isvfat) { 732 if (sbi->nls_io) 733 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 734 735 switch (opts->shortname) { 736 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 737 seq_puts(m, ",shortname=win95"); 738 break; 739 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 740 seq_puts(m, ",shortname=winnt"); 741 break; 742 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 743 seq_puts(m, ",shortname=mixed"); 744 break; 745 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 746 seq_puts(m, ",shortname=lower"); 747 break; 748 default: 749 seq_puts(m, ",shortname=unknown"); 750 break; 751 } 752 } 753 if (opts->name_check != 'n') 754 seq_printf(m, ",check=%c", opts->name_check); 755 if (opts->usefree) 756 seq_puts(m, ",usefree"); 757 if (opts->quiet) 758 seq_puts(m, ",quiet"); 759 if (opts->nfs) 760 seq_puts(m, ",nfs"); 761 if (opts->showexec) 762 seq_puts(m, ",showexec"); 763 if (opts->sys_immutable) 764 seq_puts(m, ",sys_immutable"); 765 if (!isvfat) { 766 if (opts->dotsOK) 767 seq_puts(m, ",dotsOK=yes"); 768 if (opts->nocase) 769 seq_puts(m, ",nocase"); 770 } else { 771 if (opts->utf8) 772 seq_puts(m, ",utf8"); 773 if (opts->unicode_xlate) 774 seq_puts(m, ",uni_xlate"); 775 if (!opts->numtail) 776 seq_puts(m, ",nonumtail"); 777 if (opts->rodir) 778 seq_puts(m, ",rodir"); 779 } 780 if (opts->flush) 781 seq_puts(m, ",flush"); 782 if (opts->tz_set) { 783 if (opts->time_offset) 784 seq_printf(m, ",time_offset=%d", opts->time_offset); 785 else 786 seq_puts(m, ",tz=UTC"); 787 } 788 if (opts->errors == FAT_ERRORS_CONT) 789 seq_puts(m, ",errors=continue"); 790 else if (opts->errors == FAT_ERRORS_PANIC) 791 seq_puts(m, ",errors=panic"); 792 else 793 seq_puts(m, ",errors=remount-ro"); 794 if (opts->discard) 795 seq_puts(m, ",discard"); 796 797 return 0; 798 } 799 800 enum { 801 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 802 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 803 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 804 Opt_immutable, Opt_dots, Opt_nodots, 805 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 806 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 807 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 808 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 809 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 810 Opt_err, 811 }; 812 813 static const match_table_t fat_tokens = { 814 {Opt_check_r, "check=relaxed"}, 815 {Opt_check_s, "check=strict"}, 816 {Opt_check_n, "check=normal"}, 817 {Opt_check_r, "check=r"}, 818 {Opt_check_s, "check=s"}, 819 {Opt_check_n, "check=n"}, 820 {Opt_uid, "uid=%u"}, 821 {Opt_gid, "gid=%u"}, 822 {Opt_umask, "umask=%o"}, 823 {Opt_dmask, "dmask=%o"}, 824 {Opt_fmask, "fmask=%o"}, 825 {Opt_allow_utime, "allow_utime=%o"}, 826 {Opt_codepage, "codepage=%u"}, 827 {Opt_usefree, "usefree"}, 828 {Opt_nocase, "nocase"}, 829 {Opt_quiet, "quiet"}, 830 {Opt_showexec, "showexec"}, 831 {Opt_debug, "debug"}, 832 {Opt_immutable, "sys_immutable"}, 833 {Opt_flush, "flush"}, 834 {Opt_tz_utc, "tz=UTC"}, 835 {Opt_time_offset, "time_offset=%d"}, 836 {Opt_err_cont, "errors=continue"}, 837 {Opt_err_panic, "errors=panic"}, 838 {Opt_err_ro, "errors=remount-ro"}, 839 {Opt_discard, "discard"}, 840 {Opt_nfs, "nfs"}, 841 {Opt_obsolete, "conv=binary"}, 842 {Opt_obsolete, "conv=text"}, 843 {Opt_obsolete, "conv=auto"}, 844 {Opt_obsolete, "conv=b"}, 845 {Opt_obsolete, "conv=t"}, 846 {Opt_obsolete, "conv=a"}, 847 {Opt_obsolete, "fat=%u"}, 848 {Opt_obsolete, "blocksize=%u"}, 849 {Opt_obsolete, "cvf_format=%20s"}, 850 {Opt_obsolete, "cvf_options=%100s"}, 851 {Opt_obsolete, "posix"}, 852 {Opt_err, NULL}, 853 }; 854 static const match_table_t msdos_tokens = { 855 {Opt_nodots, "nodots"}, 856 {Opt_nodots, "dotsOK=no"}, 857 {Opt_dots, "dots"}, 858 {Opt_dots, "dotsOK=yes"}, 859 {Opt_err, NULL} 860 }; 861 static const match_table_t vfat_tokens = { 862 {Opt_charset, "iocharset=%s"}, 863 {Opt_shortname_lower, "shortname=lower"}, 864 {Opt_shortname_win95, "shortname=win95"}, 865 {Opt_shortname_winnt, "shortname=winnt"}, 866 {Opt_shortname_mixed, "shortname=mixed"}, 867 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 868 {Opt_utf8_no, "utf8=no"}, 869 {Opt_utf8_no, "utf8=false"}, 870 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 871 {Opt_utf8_yes, "utf8=yes"}, 872 {Opt_utf8_yes, "utf8=true"}, 873 {Opt_utf8_yes, "utf8"}, 874 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 875 {Opt_uni_xl_no, "uni_xlate=no"}, 876 {Opt_uni_xl_no, "uni_xlate=false"}, 877 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 878 {Opt_uni_xl_yes, "uni_xlate=yes"}, 879 {Opt_uni_xl_yes, "uni_xlate=true"}, 880 {Opt_uni_xl_yes, "uni_xlate"}, 881 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 882 {Opt_nonumtail_no, "nonumtail=no"}, 883 {Opt_nonumtail_no, "nonumtail=false"}, 884 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 885 {Opt_nonumtail_yes, "nonumtail=yes"}, 886 {Opt_nonumtail_yes, "nonumtail=true"}, 887 {Opt_nonumtail_yes, "nonumtail"}, 888 {Opt_rodir, "rodir"}, 889 {Opt_err, NULL} 890 }; 891 892 static int parse_options(struct super_block *sb, char *options, int is_vfat, 893 int silent, int *debug, struct fat_mount_options *opts) 894 { 895 char *p; 896 substring_t args[MAX_OPT_ARGS]; 897 int option; 898 char *iocharset; 899 900 opts->isvfat = is_vfat; 901 902 opts->fs_uid = current_uid(); 903 opts->fs_gid = current_gid(); 904 opts->fs_fmask = opts->fs_dmask = current_umask(); 905 opts->allow_utime = -1; 906 opts->codepage = fat_default_codepage; 907 opts->iocharset = fat_default_iocharset; 908 if (is_vfat) { 909 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 910 opts->rodir = 0; 911 } else { 912 opts->shortname = 0; 913 opts->rodir = 1; 914 } 915 opts->name_check = 'n'; 916 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 917 opts->utf8 = opts->unicode_xlate = 0; 918 opts->numtail = 1; 919 opts->usefree = opts->nocase = 0; 920 opts->tz_set = 0; 921 opts->nfs = 0; 922 opts->errors = FAT_ERRORS_RO; 923 *debug = 0; 924 925 if (!options) 926 goto out; 927 928 while ((p = strsep(&options, ",")) != NULL) { 929 int token; 930 if (!*p) 931 continue; 932 933 token = match_token(p, fat_tokens, args); 934 if (token == Opt_err) { 935 if (is_vfat) 936 token = match_token(p, vfat_tokens, args); 937 else 938 token = match_token(p, msdos_tokens, args); 939 } 940 switch (token) { 941 case Opt_check_s: 942 opts->name_check = 's'; 943 break; 944 case Opt_check_r: 945 opts->name_check = 'r'; 946 break; 947 case Opt_check_n: 948 opts->name_check = 'n'; 949 break; 950 case Opt_usefree: 951 opts->usefree = 1; 952 break; 953 case Opt_nocase: 954 if (!is_vfat) 955 opts->nocase = 1; 956 else { 957 /* for backward compatibility */ 958 opts->shortname = VFAT_SFN_DISPLAY_WIN95 959 | VFAT_SFN_CREATE_WIN95; 960 } 961 break; 962 case Opt_quiet: 963 opts->quiet = 1; 964 break; 965 case Opt_showexec: 966 opts->showexec = 1; 967 break; 968 case Opt_debug: 969 *debug = 1; 970 break; 971 case Opt_immutable: 972 opts->sys_immutable = 1; 973 break; 974 case Opt_uid: 975 if (match_int(&args[0], &option)) 976 return -EINVAL; 977 opts->fs_uid = make_kuid(current_user_ns(), option); 978 if (!uid_valid(opts->fs_uid)) 979 return -EINVAL; 980 break; 981 case Opt_gid: 982 if (match_int(&args[0], &option)) 983 return -EINVAL; 984 opts->fs_gid = make_kgid(current_user_ns(), option); 985 if (!gid_valid(opts->fs_gid)) 986 return -EINVAL; 987 break; 988 case Opt_umask: 989 if (match_octal(&args[0], &option)) 990 return -EINVAL; 991 opts->fs_fmask = opts->fs_dmask = option; 992 break; 993 case Opt_dmask: 994 if (match_octal(&args[0], &option)) 995 return -EINVAL; 996 opts->fs_dmask = option; 997 break; 998 case Opt_fmask: 999 if (match_octal(&args[0], &option)) 1000 return -EINVAL; 1001 opts->fs_fmask = option; 1002 break; 1003 case Opt_allow_utime: 1004 if (match_octal(&args[0], &option)) 1005 return -EINVAL; 1006 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1007 break; 1008 case Opt_codepage: 1009 if (match_int(&args[0], &option)) 1010 return -EINVAL; 1011 opts->codepage = option; 1012 break; 1013 case Opt_flush: 1014 opts->flush = 1; 1015 break; 1016 case Opt_time_offset: 1017 if (match_int(&args[0], &option)) 1018 return -EINVAL; 1019 if (option < -12 * 60 || option > 12 * 60) 1020 return -EINVAL; 1021 opts->tz_set = 1; 1022 opts->time_offset = option; 1023 break; 1024 case Opt_tz_utc: 1025 opts->tz_set = 1; 1026 opts->time_offset = 0; 1027 break; 1028 case Opt_err_cont: 1029 opts->errors = FAT_ERRORS_CONT; 1030 break; 1031 case Opt_err_panic: 1032 opts->errors = FAT_ERRORS_PANIC; 1033 break; 1034 case Opt_err_ro: 1035 opts->errors = FAT_ERRORS_RO; 1036 break; 1037 1038 /* msdos specific */ 1039 case Opt_dots: 1040 opts->dotsOK = 1; 1041 break; 1042 case Opt_nodots: 1043 opts->dotsOK = 0; 1044 break; 1045 1046 /* vfat specific */ 1047 case Opt_charset: 1048 if (opts->iocharset != fat_default_iocharset) 1049 kfree(opts->iocharset); 1050 iocharset = match_strdup(&args[0]); 1051 if (!iocharset) 1052 return -ENOMEM; 1053 opts->iocharset = iocharset; 1054 break; 1055 case Opt_shortname_lower: 1056 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1057 | VFAT_SFN_CREATE_WIN95; 1058 break; 1059 case Opt_shortname_win95: 1060 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1061 | VFAT_SFN_CREATE_WIN95; 1062 break; 1063 case Opt_shortname_winnt: 1064 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1065 | VFAT_SFN_CREATE_WINNT; 1066 break; 1067 case Opt_shortname_mixed: 1068 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1069 | VFAT_SFN_CREATE_WIN95; 1070 break; 1071 case Opt_utf8_no: /* 0 or no or false */ 1072 opts->utf8 = 0; 1073 break; 1074 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1075 opts->utf8 = 1; 1076 break; 1077 case Opt_uni_xl_no: /* 0 or no or false */ 1078 opts->unicode_xlate = 0; 1079 break; 1080 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1081 opts->unicode_xlate = 1; 1082 break; 1083 case Opt_nonumtail_no: /* 0 or no or false */ 1084 opts->numtail = 1; /* negated option */ 1085 break; 1086 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1087 opts->numtail = 0; /* negated option */ 1088 break; 1089 case Opt_rodir: 1090 opts->rodir = 1; 1091 break; 1092 case Opt_discard: 1093 opts->discard = 1; 1094 break; 1095 case Opt_nfs: 1096 opts->nfs = 1; 1097 break; 1098 1099 /* obsolete mount options */ 1100 case Opt_obsolete: 1101 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1102 "not supported now", p); 1103 break; 1104 /* unknown option */ 1105 default: 1106 if (!silent) { 1107 fat_msg(sb, KERN_ERR, 1108 "Unrecognized mount option \"%s\" " 1109 "or missing value", p); 1110 } 1111 return -EINVAL; 1112 } 1113 } 1114 1115 out: 1116 /* UTF-8 doesn't provide FAT semantics */ 1117 if (!strcmp(opts->iocharset, "utf8")) { 1118 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1119 " for FAT filesystems, filesystem will be " 1120 "case sensitive!"); 1121 } 1122 1123 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1124 if (opts->allow_utime == (unsigned short)-1) 1125 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1126 if (opts->unicode_xlate) 1127 opts->utf8 = 0; 1128 1129 return 0; 1130 } 1131 1132 static int fat_read_root(struct inode *inode) 1133 { 1134 struct super_block *sb = inode->i_sb; 1135 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1136 int error; 1137 1138 MSDOS_I(inode)->i_pos = 0; 1139 inode->i_uid = sbi->options.fs_uid; 1140 inode->i_gid = sbi->options.fs_gid; 1141 inode->i_version++; 1142 inode->i_generation = 0; 1143 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1144 inode->i_op = sbi->dir_ops; 1145 inode->i_fop = &fat_dir_operations; 1146 if (sbi->fat_bits == 32) { 1147 MSDOS_I(inode)->i_start = sbi->root_cluster; 1148 error = fat_calc_dir_size(inode); 1149 if (error < 0) 1150 return error; 1151 } else { 1152 MSDOS_I(inode)->i_start = 0; 1153 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1154 } 1155 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1156 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1157 MSDOS_I(inode)->i_logstart = 0; 1158 MSDOS_I(inode)->mmu_private = inode->i_size; 1159 1160 fat_save_attrs(inode, ATTR_DIR); 1161 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1162 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1163 set_nlink(inode, fat_subdirs(inode)+2); 1164 1165 return 0; 1166 } 1167 1168 /* 1169 * Read the super block of an MS-DOS FS. 1170 */ 1171 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1172 void (*setup)(struct super_block *)) 1173 { 1174 struct inode *root_inode = NULL, *fat_inode = NULL; 1175 struct inode *fsinfo_inode = NULL; 1176 struct buffer_head *bh; 1177 struct fat_boot_sector *b; 1178 struct msdos_sb_info *sbi; 1179 u16 logical_sector_size; 1180 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1181 int debug; 1182 unsigned int media; 1183 long error; 1184 char buf[50]; 1185 1186 /* 1187 * GFP_KERNEL is ok here, because while we do hold the 1188 * supeblock lock, memory pressure can't call back into 1189 * the filesystem, since we're only just about to mount 1190 * it and have no inodes etc active! 1191 */ 1192 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1193 if (!sbi) 1194 return -ENOMEM; 1195 sb->s_fs_info = sbi; 1196 1197 sb->s_flags |= MS_NODIRATIME; 1198 sb->s_magic = MSDOS_SUPER_MAGIC; 1199 sb->s_op = &fat_sops; 1200 sb->s_export_op = &fat_export_ops; 1201 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1202 DEFAULT_RATELIMIT_BURST); 1203 1204 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1205 if (error) 1206 goto out_fail; 1207 1208 setup(sb); /* flavour-specific stuff that needs options */ 1209 1210 error = -EIO; 1211 sb_min_blocksize(sb, 512); 1212 bh = sb_bread(sb, 0); 1213 if (bh == NULL) { 1214 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1215 goto out_fail; 1216 } 1217 1218 b = (struct fat_boot_sector *) bh->b_data; 1219 if (!b->reserved) { 1220 if (!silent) 1221 fat_msg(sb, KERN_ERR, "bogus number of reserved sectors"); 1222 brelse(bh); 1223 goto out_invalid; 1224 } 1225 if (!b->fats) { 1226 if (!silent) 1227 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1228 brelse(bh); 1229 goto out_invalid; 1230 } 1231 1232 /* 1233 * Earlier we checked here that b->secs_track and b->head are nonzero, 1234 * but it turns out valid FAT filesystems can have zero there. 1235 */ 1236 1237 media = b->media; 1238 if (!fat_valid_media(media)) { 1239 if (!silent) 1240 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1241 media); 1242 brelse(bh); 1243 goto out_invalid; 1244 } 1245 logical_sector_size = get_unaligned_le16(&b->sector_size); 1246 if (!is_power_of_2(logical_sector_size) 1247 || (logical_sector_size < 512) 1248 || (logical_sector_size > 4096)) { 1249 if (!silent) 1250 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1251 logical_sector_size); 1252 brelse(bh); 1253 goto out_invalid; 1254 } 1255 sbi->sec_per_clus = b->sec_per_clus; 1256 if (!is_power_of_2(sbi->sec_per_clus)) { 1257 if (!silent) 1258 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1259 sbi->sec_per_clus); 1260 brelse(bh); 1261 goto out_invalid; 1262 } 1263 1264 if (logical_sector_size < sb->s_blocksize) { 1265 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1266 " (logical sector size = %u)", logical_sector_size); 1267 brelse(bh); 1268 goto out_fail; 1269 } 1270 if (logical_sector_size > sb->s_blocksize) { 1271 brelse(bh); 1272 1273 if (!sb_set_blocksize(sb, logical_sector_size)) { 1274 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1275 logical_sector_size); 1276 goto out_fail; 1277 } 1278 bh = sb_bread(sb, 0); 1279 if (bh == NULL) { 1280 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1281 " (logical sector size = %lu)", 1282 sb->s_blocksize); 1283 goto out_fail; 1284 } 1285 b = (struct fat_boot_sector *) bh->b_data; 1286 } 1287 1288 mutex_init(&sbi->s_lock); 1289 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1290 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1291 sbi->fats = b->fats; 1292 sbi->fat_bits = 0; /* Don't know yet */ 1293 sbi->fat_start = le16_to_cpu(b->reserved); 1294 sbi->fat_length = le16_to_cpu(b->fat_length); 1295 sbi->root_cluster = 0; 1296 sbi->free_clusters = -1; /* Don't know yet */ 1297 sbi->free_clus_valid = 0; 1298 sbi->prev_free = FAT_START_ENT; 1299 sb->s_maxbytes = 0xffffffff; 1300 1301 if (!sbi->fat_length && b->fat32_length) { 1302 struct fat_boot_fsinfo *fsinfo; 1303 struct buffer_head *fsinfo_bh; 1304 1305 /* Must be FAT32 */ 1306 sbi->fat_bits = 32; 1307 sbi->fat_length = le32_to_cpu(b->fat32_length); 1308 sbi->root_cluster = le32_to_cpu(b->root_cluster); 1309 1310 /* MC - if info_sector is 0, don't multiply by 0 */ 1311 sbi->fsinfo_sector = le16_to_cpu(b->info_sector); 1312 if (sbi->fsinfo_sector == 0) 1313 sbi->fsinfo_sector = 1; 1314 1315 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1316 if (fsinfo_bh == NULL) { 1317 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1318 " (sector = %lu)", sbi->fsinfo_sector); 1319 brelse(bh); 1320 goto out_fail; 1321 } 1322 1323 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1324 if (!IS_FSINFO(fsinfo)) { 1325 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1326 "0x%08x, 0x%08x (sector = %lu)", 1327 le32_to_cpu(fsinfo->signature1), 1328 le32_to_cpu(fsinfo->signature2), 1329 sbi->fsinfo_sector); 1330 } else { 1331 if (sbi->options.usefree) 1332 sbi->free_clus_valid = 1; 1333 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1334 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1335 } 1336 1337 brelse(fsinfo_bh); 1338 } 1339 1340 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1341 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1342 1343 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1344 sbi->dir_entries = get_unaligned_le16(&b->dir_entries); 1345 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1346 if (!silent) 1347 fat_msg(sb, KERN_ERR, "bogus directroy-entries per block" 1348 " (%u)", sbi->dir_entries); 1349 brelse(bh); 1350 goto out_invalid; 1351 } 1352 1353 rootdir_sectors = sbi->dir_entries 1354 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1355 sbi->data_start = sbi->dir_start + rootdir_sectors; 1356 total_sectors = get_unaligned_le16(&b->sectors); 1357 if (total_sectors == 0) 1358 total_sectors = le32_to_cpu(b->total_sect); 1359 1360 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1361 1362 if (sbi->fat_bits != 32) 1363 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1364 1365 /* check that FAT table does not overflow */ 1366 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1367 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1368 if (total_clusters > MAX_FAT(sb)) { 1369 if (!silent) 1370 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1371 total_clusters); 1372 brelse(bh); 1373 goto out_invalid; 1374 } 1375 1376 sbi->max_cluster = total_clusters + FAT_START_ENT; 1377 /* check the free_clusters, it's not necessarily correct */ 1378 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1379 sbi->free_clusters = -1; 1380 /* check the prev_free, it's not necessarily correct */ 1381 sbi->prev_free %= sbi->max_cluster; 1382 if (sbi->prev_free < FAT_START_ENT) 1383 sbi->prev_free = FAT_START_ENT; 1384 1385 brelse(bh); 1386 1387 /* set up enough so that it can read an inode */ 1388 fat_hash_init(sb); 1389 dir_hash_init(sb); 1390 fat_ent_access_init(sb); 1391 1392 /* 1393 * The low byte of FAT's first entry must have same value with 1394 * media-field. But in real world, too many devices is 1395 * writing wrong value. So, removed that validity check. 1396 * 1397 * if (FAT_FIRST_ENT(sb, media) != first) 1398 */ 1399 1400 error = -EINVAL; 1401 sprintf(buf, "cp%d", sbi->options.codepage); 1402 sbi->nls_disk = load_nls(buf); 1403 if (!sbi->nls_disk) { 1404 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1405 goto out_fail; 1406 } 1407 1408 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1409 if (sbi->options.isvfat) { 1410 sbi->nls_io = load_nls(sbi->options.iocharset); 1411 if (!sbi->nls_io) { 1412 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1413 sbi->options.iocharset); 1414 goto out_fail; 1415 } 1416 } 1417 1418 error = -ENOMEM; 1419 fat_inode = new_inode(sb); 1420 if (!fat_inode) 1421 goto out_fail; 1422 MSDOS_I(fat_inode)->i_pos = 0; 1423 sbi->fat_inode = fat_inode; 1424 1425 fsinfo_inode = new_inode(sb); 1426 if (!fsinfo_inode) 1427 goto out_fail; 1428 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1429 sbi->fsinfo_inode = fsinfo_inode; 1430 insert_inode_hash(fsinfo_inode); 1431 1432 root_inode = new_inode(sb); 1433 if (!root_inode) 1434 goto out_fail; 1435 root_inode->i_ino = MSDOS_ROOT_INO; 1436 root_inode->i_version = 1; 1437 error = fat_read_root(root_inode); 1438 if (error < 0) { 1439 iput(root_inode); 1440 goto out_fail; 1441 } 1442 error = -ENOMEM; 1443 insert_inode_hash(root_inode); 1444 fat_attach(root_inode, 0); 1445 sb->s_root = d_make_root(root_inode); 1446 if (!sb->s_root) { 1447 fat_msg(sb, KERN_ERR, "get root inode failed"); 1448 goto out_fail; 1449 } 1450 1451 if (sbi->options.discard) { 1452 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1453 if (!blk_queue_discard(q)) 1454 fat_msg(sb, KERN_WARNING, 1455 "mounting with \"discard\" option, but " 1456 "the device does not support discard"); 1457 } 1458 1459 return 0; 1460 1461 out_invalid: 1462 error = -EINVAL; 1463 if (!silent) 1464 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1465 1466 out_fail: 1467 if (fsinfo_inode) 1468 iput(fsinfo_inode); 1469 if (fat_inode) 1470 iput(fat_inode); 1471 unload_nls(sbi->nls_io); 1472 unload_nls(sbi->nls_disk); 1473 if (sbi->options.iocharset != fat_default_iocharset) 1474 kfree(sbi->options.iocharset); 1475 sb->s_fs_info = NULL; 1476 kfree(sbi); 1477 return error; 1478 } 1479 1480 EXPORT_SYMBOL_GPL(fat_fill_super); 1481 1482 /* 1483 * helper function for fat_flush_inodes. This writes both the inode 1484 * and the file data blocks, waiting for in flight data blocks before 1485 * the start of the call. It does not wait for any io started 1486 * during the call 1487 */ 1488 static int writeback_inode(struct inode *inode) 1489 { 1490 1491 int ret; 1492 1493 /* if we used wait=1, sync_inode_metadata waits for the io for the 1494 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1495 * and filemap_fdatawrite is used for the data blocks 1496 */ 1497 ret = sync_inode_metadata(inode, 0); 1498 if (!ret) 1499 ret = filemap_fdatawrite(inode->i_mapping); 1500 return ret; 1501 } 1502 1503 /* 1504 * write data and metadata corresponding to i1 and i2. The io is 1505 * started but we do not wait for any of it to finish. 1506 * 1507 * filemap_flush is used for the block device, so if there is a dirty 1508 * page for a block already in flight, we will not wait and start the 1509 * io over again 1510 */ 1511 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1512 { 1513 int ret = 0; 1514 if (!MSDOS_SB(sb)->options.flush) 1515 return 0; 1516 if (i1) 1517 ret = writeback_inode(i1); 1518 if (!ret && i2) 1519 ret = writeback_inode(i2); 1520 if (!ret) { 1521 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1522 ret = filemap_flush(mapping); 1523 } 1524 return ret; 1525 } 1526 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1527 1528 static int __init init_fat_fs(void) 1529 { 1530 int err; 1531 1532 err = fat_cache_init(); 1533 if (err) 1534 return err; 1535 1536 err = fat_init_inodecache(); 1537 if (err) 1538 goto failed; 1539 1540 return 0; 1541 1542 failed: 1543 fat_cache_destroy(); 1544 return err; 1545 } 1546 1547 static void __exit exit_fat_fs(void) 1548 { 1549 fat_cache_destroy(); 1550 fat_destroy_inodecache(); 1551 } 1552 1553 module_init(init_fat_fs) 1554 module_exit(exit_fat_fs) 1555 1556 MODULE_LICENSE("GPL"); 1557