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/pagemap.h> 15 #include <linux/mpage.h> 16 #include <linux/vfs.h> 17 #include <linux/seq_file.h> 18 #include <linux/parser.h> 19 #include <linux/uio.h> 20 #include <linux/blkdev.h> 21 #include <linux/backing-dev.h> 22 #include <asm/unaligned.h> 23 #include <linux/iversion.h> 24 #include "fat.h" 25 26 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET 27 /* if user don't select VFAT, this is undefined. */ 28 #define CONFIG_FAT_DEFAULT_IOCHARSET "" 29 #endif 30 31 #define KB_IN_SECTORS 2 32 33 /* 34 * A deserialized copy of the on-disk structure laid out in struct 35 * fat_boot_sector. 36 */ 37 struct fat_bios_param_block { 38 u16 fat_sector_size; 39 u8 fat_sec_per_clus; 40 u16 fat_reserved; 41 u8 fat_fats; 42 u16 fat_dir_entries; 43 u16 fat_sectors; 44 u16 fat_fat_length; 45 u32 fat_total_sect; 46 47 u8 fat16_state; 48 u32 fat16_vol_id; 49 50 u32 fat32_length; 51 u32 fat32_root_cluster; 52 u16 fat32_info_sector; 53 u8 fat32_state; 54 u32 fat32_vol_id; 55 }; 56 57 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; 58 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; 59 60 static struct fat_floppy_defaults { 61 unsigned nr_sectors; 62 unsigned sec_per_clus; 63 unsigned dir_entries; 64 unsigned media; 65 unsigned fat_length; 66 } floppy_defaults[] = { 67 { 68 .nr_sectors = 160 * KB_IN_SECTORS, 69 .sec_per_clus = 1, 70 .dir_entries = 64, 71 .media = 0xFE, 72 .fat_length = 1, 73 }, 74 { 75 .nr_sectors = 180 * KB_IN_SECTORS, 76 .sec_per_clus = 1, 77 .dir_entries = 64, 78 .media = 0xFC, 79 .fat_length = 2, 80 }, 81 { 82 .nr_sectors = 320 * KB_IN_SECTORS, 83 .sec_per_clus = 2, 84 .dir_entries = 112, 85 .media = 0xFF, 86 .fat_length = 1, 87 }, 88 { 89 .nr_sectors = 360 * KB_IN_SECTORS, 90 .sec_per_clus = 2, 91 .dir_entries = 112, 92 .media = 0xFD, 93 .fat_length = 2, 94 }, 95 }; 96 97 int fat_add_cluster(struct inode *inode) 98 { 99 int err, cluster; 100 101 err = fat_alloc_clusters(inode, &cluster, 1); 102 if (err) 103 return err; 104 /* FIXME: this cluster should be added after data of this 105 * cluster is writed */ 106 err = fat_chain_add(inode, cluster, 1); 107 if (err) 108 fat_free_clusters(inode, cluster); 109 return err; 110 } 111 112 static inline int __fat_get_block(struct inode *inode, sector_t iblock, 113 unsigned long *max_blocks, 114 struct buffer_head *bh_result, int create) 115 { 116 struct super_block *sb = inode->i_sb; 117 struct msdos_sb_info *sbi = MSDOS_SB(sb); 118 unsigned long mapped_blocks; 119 sector_t phys, last_block; 120 int err, offset; 121 122 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 123 if (err) 124 return err; 125 if (phys) { 126 map_bh(bh_result, sb, phys); 127 *max_blocks = min(mapped_blocks, *max_blocks); 128 return 0; 129 } 130 if (!create) 131 return 0; 132 133 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { 134 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", 135 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); 136 return -EIO; 137 } 138 139 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); 140 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); 141 /* 142 * allocate a cluster according to the following. 143 * 1) no more available blocks 144 * 2) not part of fallocate region 145 */ 146 if (!offset && !(iblock < last_block)) { 147 /* TODO: multiple cluster allocation would be desirable. */ 148 err = fat_add_cluster(inode); 149 if (err) 150 return err; 151 } 152 /* available blocks on this cluster */ 153 mapped_blocks = sbi->sec_per_clus - offset; 154 155 *max_blocks = min(mapped_blocks, *max_blocks); 156 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; 157 158 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); 159 if (err) 160 return err; 161 162 BUG_ON(!phys); 163 BUG_ON(*max_blocks != mapped_blocks); 164 set_buffer_new(bh_result); 165 map_bh(bh_result, sb, phys); 166 167 return 0; 168 } 169 170 static int fat_get_block(struct inode *inode, sector_t iblock, 171 struct buffer_head *bh_result, int create) 172 { 173 struct super_block *sb = inode->i_sb; 174 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 175 int err; 176 177 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); 178 if (err) 179 return err; 180 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 181 return 0; 182 } 183 184 static int fat_writepage(struct page *page, struct writeback_control *wbc) 185 { 186 return block_write_full_page(page, fat_get_block, wbc); 187 } 188 189 static int fat_writepages(struct address_space *mapping, 190 struct writeback_control *wbc) 191 { 192 return mpage_writepages(mapping, wbc, fat_get_block); 193 } 194 195 static int fat_readpage(struct file *file, struct page *page) 196 { 197 return mpage_readpage(page, fat_get_block); 198 } 199 200 static int fat_readpages(struct file *file, struct address_space *mapping, 201 struct list_head *pages, unsigned nr_pages) 202 { 203 return mpage_readpages(mapping, pages, nr_pages, fat_get_block); 204 } 205 206 static void fat_write_failed(struct address_space *mapping, loff_t to) 207 { 208 struct inode *inode = mapping->host; 209 210 if (to > inode->i_size) { 211 truncate_pagecache(inode, inode->i_size); 212 fat_truncate_blocks(inode, inode->i_size); 213 } 214 } 215 216 static int fat_write_begin(struct file *file, struct address_space *mapping, 217 loff_t pos, unsigned len, unsigned flags, 218 struct page **pagep, void **fsdata) 219 { 220 int err; 221 222 *pagep = NULL; 223 err = cont_write_begin(file, mapping, pos, len, flags, 224 pagep, fsdata, fat_get_block, 225 &MSDOS_I(mapping->host)->mmu_private); 226 if (err < 0) 227 fat_write_failed(mapping, pos + len); 228 return err; 229 } 230 231 static int fat_write_end(struct file *file, struct address_space *mapping, 232 loff_t pos, unsigned len, unsigned copied, 233 struct page *pagep, void *fsdata) 234 { 235 struct inode *inode = mapping->host; 236 int err; 237 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 238 if (err < len) 239 fat_write_failed(mapping, pos + len); 240 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { 241 inode->i_mtime = inode->i_ctime = current_time(inode); 242 MSDOS_I(inode)->i_attrs |= ATTR_ARCH; 243 mark_inode_dirty(inode); 244 } 245 return err; 246 } 247 248 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 249 { 250 struct file *file = iocb->ki_filp; 251 struct address_space *mapping = file->f_mapping; 252 struct inode *inode = mapping->host; 253 size_t count = iov_iter_count(iter); 254 loff_t offset = iocb->ki_pos; 255 ssize_t ret; 256 257 if (iov_iter_rw(iter) == WRITE) { 258 /* 259 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), 260 * so we need to update the ->mmu_private to block boundary. 261 * 262 * But we must fill the remaining area or hole by nul for 263 * updating ->mmu_private. 264 * 265 * Return 0, and fallback to normal buffered write. 266 */ 267 loff_t size = offset + count; 268 if (MSDOS_I(inode)->mmu_private < size) 269 return 0; 270 } 271 272 /* 273 * FAT need to use the DIO_LOCKING for avoiding the race 274 * condition of fat_get_block() and ->truncate(). 275 */ 276 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); 277 if (ret < 0 && iov_iter_rw(iter) == WRITE) 278 fat_write_failed(mapping, offset + count); 279 280 return ret; 281 } 282 283 static int fat_get_block_bmap(struct inode *inode, sector_t iblock, 284 struct buffer_head *bh_result, int create) 285 { 286 struct super_block *sb = inode->i_sb; 287 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; 288 int err; 289 sector_t bmap; 290 unsigned long mapped_blocks; 291 292 BUG_ON(create != 0); 293 294 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); 295 if (err) 296 return err; 297 298 if (bmap) { 299 map_bh(bh_result, sb, bmap); 300 max_blocks = min(mapped_blocks, max_blocks); 301 } 302 303 bh_result->b_size = max_blocks << sb->s_blocksize_bits; 304 305 return 0; 306 } 307 308 static sector_t _fat_bmap(struct address_space *mapping, sector_t block) 309 { 310 sector_t blocknr; 311 312 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ 313 down_read(&MSDOS_I(mapping->host)->truncate_lock); 314 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); 315 up_read(&MSDOS_I(mapping->host)->truncate_lock); 316 317 return blocknr; 318 } 319 320 /* 321 * fat_block_truncate_page() zeroes out a mapping from file offset `from' 322 * up to the end of the block which corresponds to `from'. 323 * This is required during truncate to physically zeroout the tail end 324 * of that block so it doesn't yield old data if the file is later grown. 325 * Also, avoid causing failure from fsx for cases of "data past EOF" 326 */ 327 int fat_block_truncate_page(struct inode *inode, loff_t from) 328 { 329 return block_truncate_page(inode->i_mapping, from, fat_get_block); 330 } 331 332 static const struct address_space_operations fat_aops = { 333 .readpage = fat_readpage, 334 .readpages = fat_readpages, 335 .writepage = fat_writepage, 336 .writepages = fat_writepages, 337 .write_begin = fat_write_begin, 338 .write_end = fat_write_end, 339 .direct_IO = fat_direct_IO, 340 .bmap = _fat_bmap 341 }; 342 343 /* 344 * New FAT inode stuff. We do the following: 345 * a) i_ino is constant and has nothing with on-disk location. 346 * b) FAT manages its own cache of directory entries. 347 * c) *This* cache is indexed by on-disk location. 348 * d) inode has an associated directory entry, all right, but 349 * it may be unhashed. 350 * e) currently entries are stored within struct inode. That should 351 * change. 352 * f) we deal with races in the following way: 353 * 1. readdir() and lookup() do FAT-dir-cache lookup. 354 * 2. rename() unhashes the F-d-c entry and rehashes it in 355 * a new place. 356 * 3. unlink() and rmdir() unhash F-d-c entry. 357 * 4. fat_write_inode() checks whether the thing is unhashed. 358 * If it is we silently return. If it isn't we do bread(), 359 * check if the location is still valid and retry if it 360 * isn't. Otherwise we do changes. 361 * 5. Spinlock is used to protect hash/unhash/location check/lookup 362 * 6. fat_evict_inode() unhashes the F-d-c entry. 363 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry 364 * and consider negative result as cache miss. 365 */ 366 367 static void fat_hash_init(struct super_block *sb) 368 { 369 struct msdos_sb_info *sbi = MSDOS_SB(sb); 370 int i; 371 372 spin_lock_init(&sbi->inode_hash_lock); 373 for (i = 0; i < FAT_HASH_SIZE; i++) 374 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); 375 } 376 377 static inline unsigned long fat_hash(loff_t i_pos) 378 { 379 return hash_32(i_pos, FAT_HASH_BITS); 380 } 381 382 static void dir_hash_init(struct super_block *sb) 383 { 384 struct msdos_sb_info *sbi = MSDOS_SB(sb); 385 int i; 386 387 spin_lock_init(&sbi->dir_hash_lock); 388 for (i = 0; i < FAT_HASH_SIZE; i++) 389 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); 390 } 391 392 void fat_attach(struct inode *inode, loff_t i_pos) 393 { 394 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 395 396 if (inode->i_ino != MSDOS_ROOT_INO) { 397 struct hlist_head *head = sbi->inode_hashtable 398 + fat_hash(i_pos); 399 400 spin_lock(&sbi->inode_hash_lock); 401 MSDOS_I(inode)->i_pos = i_pos; 402 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); 403 spin_unlock(&sbi->inode_hash_lock); 404 } 405 406 /* If NFS support is enabled, cache the mapping of start cluster 407 * to directory inode. This is used during reconnection of 408 * dentries to the filesystem root. 409 */ 410 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 411 struct hlist_head *d_head = sbi->dir_hashtable; 412 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); 413 414 spin_lock(&sbi->dir_hash_lock); 415 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); 416 spin_unlock(&sbi->dir_hash_lock); 417 } 418 } 419 EXPORT_SYMBOL_GPL(fat_attach); 420 421 void fat_detach(struct inode *inode) 422 { 423 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 424 spin_lock(&sbi->inode_hash_lock); 425 MSDOS_I(inode)->i_pos = 0; 426 hlist_del_init(&MSDOS_I(inode)->i_fat_hash); 427 spin_unlock(&sbi->inode_hash_lock); 428 429 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { 430 spin_lock(&sbi->dir_hash_lock); 431 hlist_del_init(&MSDOS_I(inode)->i_dir_hash); 432 spin_unlock(&sbi->dir_hash_lock); 433 } 434 } 435 EXPORT_SYMBOL_GPL(fat_detach); 436 437 struct inode *fat_iget(struct super_block *sb, loff_t i_pos) 438 { 439 struct msdos_sb_info *sbi = MSDOS_SB(sb); 440 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); 441 struct msdos_inode_info *i; 442 struct inode *inode = NULL; 443 444 spin_lock(&sbi->inode_hash_lock); 445 hlist_for_each_entry(i, head, i_fat_hash) { 446 BUG_ON(i->vfs_inode.i_sb != sb); 447 if (i->i_pos != i_pos) 448 continue; 449 inode = igrab(&i->vfs_inode); 450 if (inode) 451 break; 452 } 453 spin_unlock(&sbi->inode_hash_lock); 454 return inode; 455 } 456 457 static int is_exec(unsigned char *extension) 458 { 459 unsigned char exe_extensions[] = "EXECOMBAT", *walk; 460 461 for (walk = exe_extensions; *walk; walk += 3) 462 if (!strncmp(extension, walk, 3)) 463 return 1; 464 return 0; 465 } 466 467 static int fat_calc_dir_size(struct inode *inode) 468 { 469 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 470 int ret, fclus, dclus; 471 472 inode->i_size = 0; 473 if (MSDOS_I(inode)->i_start == 0) 474 return 0; 475 476 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); 477 if (ret < 0) 478 return ret; 479 inode->i_size = (fclus + 1) << sbi->cluster_bits; 480 481 return 0; 482 } 483 484 static int fat_validate_dir(struct inode *dir) 485 { 486 struct super_block *sb = dir->i_sb; 487 488 if (dir->i_nlink < 2) { 489 /* Directory should have "."/".." entries at least. */ 490 fat_fs_error(sb, "corrupted directory (invalid entries)"); 491 return -EIO; 492 } 493 if (MSDOS_I(dir)->i_start == 0 || 494 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { 495 /* Directory should point valid cluster. */ 496 fat_fs_error(sb, "corrupted directory (invalid i_start)"); 497 return -EIO; 498 } 499 return 0; 500 } 501 502 /* doesn't deal with root inode */ 503 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 504 { 505 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 506 int error; 507 508 MSDOS_I(inode)->i_pos = 0; 509 inode->i_uid = sbi->options.fs_uid; 510 inode->i_gid = sbi->options.fs_gid; 511 inode_inc_iversion(inode); 512 inode->i_generation = get_seconds(); 513 514 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { 515 inode->i_generation &= ~1; 516 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); 517 inode->i_op = sbi->dir_ops; 518 inode->i_fop = &fat_dir_operations; 519 520 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 521 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 522 error = fat_calc_dir_size(inode); 523 if (error < 0) 524 return error; 525 MSDOS_I(inode)->mmu_private = inode->i_size; 526 527 set_nlink(inode, fat_subdirs(inode)); 528 529 error = fat_validate_dir(inode); 530 if (error < 0) 531 return error; 532 } else { /* not a directory */ 533 inode->i_generation |= 1; 534 inode->i_mode = fat_make_mode(sbi, de->attr, 535 ((sbi->options.showexec && !is_exec(de->name + 8)) 536 ? S_IRUGO|S_IWUGO : S_IRWXUGO)); 537 MSDOS_I(inode)->i_start = fat_get_start(sbi, de); 538 539 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; 540 inode->i_size = le32_to_cpu(de->size); 541 inode->i_op = &fat_file_inode_operations; 542 inode->i_fop = &fat_file_operations; 543 inode->i_mapping->a_ops = &fat_aops; 544 MSDOS_I(inode)->mmu_private = inode->i_size; 545 } 546 if (de->attr & ATTR_SYS) { 547 if (sbi->options.sys_immutable) 548 inode->i_flags |= S_IMMUTABLE; 549 } 550 fat_save_attrs(inode, de->attr); 551 552 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 553 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 554 555 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); 556 if (sbi->options.isvfat) { 557 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, 558 de->cdate, de->ctime_cs); 559 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); 560 } else 561 inode->i_ctime = inode->i_atime = inode->i_mtime; 562 563 return 0; 564 } 565 566 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) 567 { 568 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 569 mutex_lock(&sbi->nfs_build_inode_lock); 570 } 571 572 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) 573 { 574 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) 575 mutex_unlock(&sbi->nfs_build_inode_lock); 576 } 577 578 struct inode *fat_build_inode(struct super_block *sb, 579 struct msdos_dir_entry *de, loff_t i_pos) 580 { 581 struct inode *inode; 582 int err; 583 584 fat_lock_build_inode(MSDOS_SB(sb)); 585 inode = fat_iget(sb, i_pos); 586 if (inode) 587 goto out; 588 inode = new_inode(sb); 589 if (!inode) { 590 inode = ERR_PTR(-ENOMEM); 591 goto out; 592 } 593 inode->i_ino = iunique(sb, MSDOS_ROOT_INO); 594 inode_set_iversion(inode, 1); 595 err = fat_fill_inode(inode, de); 596 if (err) { 597 iput(inode); 598 inode = ERR_PTR(err); 599 goto out; 600 } 601 fat_attach(inode, i_pos); 602 insert_inode_hash(inode); 603 out: 604 fat_unlock_build_inode(MSDOS_SB(sb)); 605 return inode; 606 } 607 608 EXPORT_SYMBOL_GPL(fat_build_inode); 609 610 static int __fat_write_inode(struct inode *inode, int wait); 611 612 static void fat_free_eofblocks(struct inode *inode) 613 { 614 /* Release unwritten fallocated blocks on inode eviction. */ 615 if ((inode->i_blocks << 9) > 616 round_up(MSDOS_I(inode)->mmu_private, 617 MSDOS_SB(inode->i_sb)->cluster_size)) { 618 int err; 619 620 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); 621 /* Fallocate results in updating the i_start/iogstart 622 * for the zero byte file. So, make it return to 623 * original state during evict and commit it to avoid 624 * any corruption on the next access to the cluster 625 * chain for the file. 626 */ 627 err = __fat_write_inode(inode, inode_needs_sync(inode)); 628 if (err) { 629 fat_msg(inode->i_sb, KERN_WARNING, "Failed to " 630 "update on disk inode for unused " 631 "fallocated blocks, inode could be " 632 "corrupted. Please run fsck"); 633 } 634 635 } 636 } 637 638 static void fat_evict_inode(struct inode *inode) 639 { 640 truncate_inode_pages_final(&inode->i_data); 641 if (!inode->i_nlink) { 642 inode->i_size = 0; 643 fat_truncate_blocks(inode, 0); 644 } else 645 fat_free_eofblocks(inode); 646 647 invalidate_inode_buffers(inode); 648 clear_inode(inode); 649 fat_cache_inval_inode(inode); 650 fat_detach(inode); 651 } 652 653 static void fat_set_state(struct super_block *sb, 654 unsigned int set, unsigned int force) 655 { 656 struct buffer_head *bh; 657 struct fat_boot_sector *b; 658 struct msdos_sb_info *sbi = MSDOS_SB(sb); 659 660 /* do not change any thing if mounted read only */ 661 if (sb_rdonly(sb) && !force) 662 return; 663 664 /* do not change state if fs was dirty */ 665 if (sbi->dirty) { 666 /* warn only on set (mount). */ 667 if (set) 668 fat_msg(sb, KERN_WARNING, "Volume was not properly " 669 "unmounted. Some data may be corrupt. " 670 "Please run fsck."); 671 return; 672 } 673 674 bh = sb_bread(sb, 0); 675 if (bh == NULL) { 676 fat_msg(sb, KERN_ERR, "unable to read boot sector " 677 "to mark fs as dirty"); 678 return; 679 } 680 681 b = (struct fat_boot_sector *) bh->b_data; 682 683 if (sbi->fat_bits == 32) { 684 if (set) 685 b->fat32.state |= FAT_STATE_DIRTY; 686 else 687 b->fat32.state &= ~FAT_STATE_DIRTY; 688 } else /* fat 16 and 12 */ { 689 if (set) 690 b->fat16.state |= FAT_STATE_DIRTY; 691 else 692 b->fat16.state &= ~FAT_STATE_DIRTY; 693 } 694 695 mark_buffer_dirty(bh); 696 sync_dirty_buffer(bh); 697 brelse(bh); 698 } 699 700 static void delayed_free(struct rcu_head *p) 701 { 702 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); 703 unload_nls(sbi->nls_disk); 704 unload_nls(sbi->nls_io); 705 if (sbi->options.iocharset != fat_default_iocharset) 706 kfree(sbi->options.iocharset); 707 kfree(sbi); 708 } 709 710 static void fat_put_super(struct super_block *sb) 711 { 712 struct msdos_sb_info *sbi = MSDOS_SB(sb); 713 714 fat_set_state(sb, 0, 0); 715 716 iput(sbi->fsinfo_inode); 717 iput(sbi->fat_inode); 718 719 call_rcu(&sbi->rcu, delayed_free); 720 } 721 722 static struct kmem_cache *fat_inode_cachep; 723 724 static struct inode *fat_alloc_inode(struct super_block *sb) 725 { 726 struct msdos_inode_info *ei; 727 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); 728 if (!ei) 729 return NULL; 730 731 init_rwsem(&ei->truncate_lock); 732 return &ei->vfs_inode; 733 } 734 735 static void fat_i_callback(struct rcu_head *head) 736 { 737 struct inode *inode = container_of(head, struct inode, i_rcu); 738 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); 739 } 740 741 static void fat_destroy_inode(struct inode *inode) 742 { 743 call_rcu(&inode->i_rcu, fat_i_callback); 744 } 745 746 static void init_once(void *foo) 747 { 748 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; 749 750 spin_lock_init(&ei->cache_lru_lock); 751 ei->nr_caches = 0; 752 ei->cache_valid_id = FAT_CACHE_VALID + 1; 753 INIT_LIST_HEAD(&ei->cache_lru); 754 INIT_HLIST_NODE(&ei->i_fat_hash); 755 INIT_HLIST_NODE(&ei->i_dir_hash); 756 inode_init_once(&ei->vfs_inode); 757 } 758 759 static int __init fat_init_inodecache(void) 760 { 761 fat_inode_cachep = kmem_cache_create("fat_inode_cache", 762 sizeof(struct msdos_inode_info), 763 0, (SLAB_RECLAIM_ACCOUNT| 764 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 765 init_once); 766 if (fat_inode_cachep == NULL) 767 return -ENOMEM; 768 return 0; 769 } 770 771 static void __exit fat_destroy_inodecache(void) 772 { 773 /* 774 * Make sure all delayed rcu free inodes are flushed before we 775 * destroy cache. 776 */ 777 rcu_barrier(); 778 kmem_cache_destroy(fat_inode_cachep); 779 } 780 781 static int fat_remount(struct super_block *sb, int *flags, char *data) 782 { 783 bool new_rdonly; 784 struct msdos_sb_info *sbi = MSDOS_SB(sb); 785 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); 786 787 sync_filesystem(sb); 788 789 /* make sure we update state on remount. */ 790 new_rdonly = *flags & SB_RDONLY; 791 if (new_rdonly != sb_rdonly(sb)) { 792 if (new_rdonly) 793 fat_set_state(sb, 0, 0); 794 else 795 fat_set_state(sb, 1, 1); 796 } 797 return 0; 798 } 799 800 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) 801 { 802 struct super_block *sb = dentry->d_sb; 803 struct msdos_sb_info *sbi = MSDOS_SB(sb); 804 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 805 806 /* If the count of free cluster is still unknown, counts it here. */ 807 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { 808 int err = fat_count_free_clusters(dentry->d_sb); 809 if (err) 810 return err; 811 } 812 813 buf->f_type = dentry->d_sb->s_magic; 814 buf->f_bsize = sbi->cluster_size; 815 buf->f_blocks = sbi->max_cluster - FAT_START_ENT; 816 buf->f_bfree = sbi->free_clusters; 817 buf->f_bavail = sbi->free_clusters; 818 buf->f_fsid.val[0] = (u32)id; 819 buf->f_fsid.val[1] = (u32)(id >> 32); 820 buf->f_namelen = 821 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; 822 823 return 0; 824 } 825 826 static int __fat_write_inode(struct inode *inode, int wait) 827 { 828 struct super_block *sb = inode->i_sb; 829 struct msdos_sb_info *sbi = MSDOS_SB(sb); 830 struct buffer_head *bh; 831 struct msdos_dir_entry *raw_entry; 832 loff_t i_pos; 833 sector_t blocknr; 834 int err, offset; 835 836 if (inode->i_ino == MSDOS_ROOT_INO) 837 return 0; 838 839 retry: 840 i_pos = fat_i_pos_read(sbi, inode); 841 if (!i_pos) 842 return 0; 843 844 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); 845 bh = sb_bread(sb, blocknr); 846 if (!bh) { 847 fat_msg(sb, KERN_ERR, "unable to read inode block " 848 "for updating (i_pos %lld)", i_pos); 849 return -EIO; 850 } 851 spin_lock(&sbi->inode_hash_lock); 852 if (i_pos != MSDOS_I(inode)->i_pos) { 853 spin_unlock(&sbi->inode_hash_lock); 854 brelse(bh); 855 goto retry; 856 } 857 858 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; 859 if (S_ISDIR(inode->i_mode)) 860 raw_entry->size = 0; 861 else 862 raw_entry->size = cpu_to_le32(inode->i_size); 863 raw_entry->attr = fat_make_attrs(inode); 864 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); 865 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, 866 &raw_entry->date, NULL); 867 if (sbi->options.isvfat) { 868 __le16 atime; 869 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, 870 &raw_entry->cdate, &raw_entry->ctime_cs); 871 fat_time_unix2fat(sbi, &inode->i_atime, &atime, 872 &raw_entry->adate, NULL); 873 } 874 spin_unlock(&sbi->inode_hash_lock); 875 mark_buffer_dirty(bh); 876 err = 0; 877 if (wait) 878 err = sync_dirty_buffer(bh); 879 brelse(bh); 880 return err; 881 } 882 883 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) 884 { 885 int err; 886 887 if (inode->i_ino == MSDOS_FSINFO_INO) { 888 struct super_block *sb = inode->i_sb; 889 890 mutex_lock(&MSDOS_SB(sb)->s_lock); 891 err = fat_clusters_flush(sb); 892 mutex_unlock(&MSDOS_SB(sb)->s_lock); 893 } else 894 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 895 896 return err; 897 } 898 899 int fat_sync_inode(struct inode *inode) 900 { 901 return __fat_write_inode(inode, 1); 902 } 903 904 EXPORT_SYMBOL_GPL(fat_sync_inode); 905 906 static int fat_show_options(struct seq_file *m, struct dentry *root); 907 static const struct super_operations fat_sops = { 908 .alloc_inode = fat_alloc_inode, 909 .destroy_inode = fat_destroy_inode, 910 .write_inode = fat_write_inode, 911 .evict_inode = fat_evict_inode, 912 .put_super = fat_put_super, 913 .statfs = fat_statfs, 914 .remount_fs = fat_remount, 915 916 .show_options = fat_show_options, 917 }; 918 919 static int fat_show_options(struct seq_file *m, struct dentry *root) 920 { 921 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); 922 struct fat_mount_options *opts = &sbi->options; 923 int isvfat = opts->isvfat; 924 925 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) 926 seq_printf(m, ",uid=%u", 927 from_kuid_munged(&init_user_ns, opts->fs_uid)); 928 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) 929 seq_printf(m, ",gid=%u", 930 from_kgid_munged(&init_user_ns, opts->fs_gid)); 931 seq_printf(m, ",fmask=%04o", opts->fs_fmask); 932 seq_printf(m, ",dmask=%04o", opts->fs_dmask); 933 if (opts->allow_utime) 934 seq_printf(m, ",allow_utime=%04o", opts->allow_utime); 935 if (sbi->nls_disk) 936 /* strip "cp" prefix from displayed option */ 937 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); 938 if (isvfat) { 939 if (sbi->nls_io) 940 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); 941 942 switch (opts->shortname) { 943 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: 944 seq_puts(m, ",shortname=win95"); 945 break; 946 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: 947 seq_puts(m, ",shortname=winnt"); 948 break; 949 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: 950 seq_puts(m, ",shortname=mixed"); 951 break; 952 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: 953 seq_puts(m, ",shortname=lower"); 954 break; 955 default: 956 seq_puts(m, ",shortname=unknown"); 957 break; 958 } 959 } 960 if (opts->name_check != 'n') 961 seq_printf(m, ",check=%c", opts->name_check); 962 if (opts->usefree) 963 seq_puts(m, ",usefree"); 964 if (opts->quiet) 965 seq_puts(m, ",quiet"); 966 if (opts->showexec) 967 seq_puts(m, ",showexec"); 968 if (opts->sys_immutable) 969 seq_puts(m, ",sys_immutable"); 970 if (!isvfat) { 971 if (opts->dotsOK) 972 seq_puts(m, ",dotsOK=yes"); 973 if (opts->nocase) 974 seq_puts(m, ",nocase"); 975 } else { 976 if (opts->utf8) 977 seq_puts(m, ",utf8"); 978 if (opts->unicode_xlate) 979 seq_puts(m, ",uni_xlate"); 980 if (!opts->numtail) 981 seq_puts(m, ",nonumtail"); 982 if (opts->rodir) 983 seq_puts(m, ",rodir"); 984 } 985 if (opts->flush) 986 seq_puts(m, ",flush"); 987 if (opts->tz_set) { 988 if (opts->time_offset) 989 seq_printf(m, ",time_offset=%d", opts->time_offset); 990 else 991 seq_puts(m, ",tz=UTC"); 992 } 993 if (opts->errors == FAT_ERRORS_CONT) 994 seq_puts(m, ",errors=continue"); 995 else if (opts->errors == FAT_ERRORS_PANIC) 996 seq_puts(m, ",errors=panic"); 997 else 998 seq_puts(m, ",errors=remount-ro"); 999 if (opts->nfs == FAT_NFS_NOSTALE_RO) 1000 seq_puts(m, ",nfs=nostale_ro"); 1001 else if (opts->nfs) 1002 seq_puts(m, ",nfs=stale_rw"); 1003 if (opts->discard) 1004 seq_puts(m, ",discard"); 1005 if (opts->dos1xfloppy) 1006 seq_puts(m, ",dos1xfloppy"); 1007 1008 return 0; 1009 } 1010 1011 enum { 1012 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, 1013 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, 1014 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, 1015 Opt_immutable, Opt_dots, Opt_nodots, 1016 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 1017 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 1018 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 1019 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, 1020 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, 1021 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, 1022 }; 1023 1024 static const match_table_t fat_tokens = { 1025 {Opt_check_r, "check=relaxed"}, 1026 {Opt_check_s, "check=strict"}, 1027 {Opt_check_n, "check=normal"}, 1028 {Opt_check_r, "check=r"}, 1029 {Opt_check_s, "check=s"}, 1030 {Opt_check_n, "check=n"}, 1031 {Opt_uid, "uid=%u"}, 1032 {Opt_gid, "gid=%u"}, 1033 {Opt_umask, "umask=%o"}, 1034 {Opt_dmask, "dmask=%o"}, 1035 {Opt_fmask, "fmask=%o"}, 1036 {Opt_allow_utime, "allow_utime=%o"}, 1037 {Opt_codepage, "codepage=%u"}, 1038 {Opt_usefree, "usefree"}, 1039 {Opt_nocase, "nocase"}, 1040 {Opt_quiet, "quiet"}, 1041 {Opt_showexec, "showexec"}, 1042 {Opt_debug, "debug"}, 1043 {Opt_immutable, "sys_immutable"}, 1044 {Opt_flush, "flush"}, 1045 {Opt_tz_utc, "tz=UTC"}, 1046 {Opt_time_offset, "time_offset=%d"}, 1047 {Opt_err_cont, "errors=continue"}, 1048 {Opt_err_panic, "errors=panic"}, 1049 {Opt_err_ro, "errors=remount-ro"}, 1050 {Opt_discard, "discard"}, 1051 {Opt_nfs_stale_rw, "nfs"}, 1052 {Opt_nfs_stale_rw, "nfs=stale_rw"}, 1053 {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, 1054 {Opt_dos1xfloppy, "dos1xfloppy"}, 1055 {Opt_obsolete, "conv=binary"}, 1056 {Opt_obsolete, "conv=text"}, 1057 {Opt_obsolete, "conv=auto"}, 1058 {Opt_obsolete, "conv=b"}, 1059 {Opt_obsolete, "conv=t"}, 1060 {Opt_obsolete, "conv=a"}, 1061 {Opt_obsolete, "fat=%u"}, 1062 {Opt_obsolete, "blocksize=%u"}, 1063 {Opt_obsolete, "cvf_format=%20s"}, 1064 {Opt_obsolete, "cvf_options=%100s"}, 1065 {Opt_obsolete, "posix"}, 1066 {Opt_err, NULL}, 1067 }; 1068 static const match_table_t msdos_tokens = { 1069 {Opt_nodots, "nodots"}, 1070 {Opt_nodots, "dotsOK=no"}, 1071 {Opt_dots, "dots"}, 1072 {Opt_dots, "dotsOK=yes"}, 1073 {Opt_err, NULL} 1074 }; 1075 static const match_table_t vfat_tokens = { 1076 {Opt_charset, "iocharset=%s"}, 1077 {Opt_shortname_lower, "shortname=lower"}, 1078 {Opt_shortname_win95, "shortname=win95"}, 1079 {Opt_shortname_winnt, "shortname=winnt"}, 1080 {Opt_shortname_mixed, "shortname=mixed"}, 1081 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ 1082 {Opt_utf8_no, "utf8=no"}, 1083 {Opt_utf8_no, "utf8=false"}, 1084 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ 1085 {Opt_utf8_yes, "utf8=yes"}, 1086 {Opt_utf8_yes, "utf8=true"}, 1087 {Opt_utf8_yes, "utf8"}, 1088 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ 1089 {Opt_uni_xl_no, "uni_xlate=no"}, 1090 {Opt_uni_xl_no, "uni_xlate=false"}, 1091 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ 1092 {Opt_uni_xl_yes, "uni_xlate=yes"}, 1093 {Opt_uni_xl_yes, "uni_xlate=true"}, 1094 {Opt_uni_xl_yes, "uni_xlate"}, 1095 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ 1096 {Opt_nonumtail_no, "nonumtail=no"}, 1097 {Opt_nonumtail_no, "nonumtail=false"}, 1098 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ 1099 {Opt_nonumtail_yes, "nonumtail=yes"}, 1100 {Opt_nonumtail_yes, "nonumtail=true"}, 1101 {Opt_nonumtail_yes, "nonumtail"}, 1102 {Opt_rodir, "rodir"}, 1103 {Opt_err, NULL} 1104 }; 1105 1106 static int parse_options(struct super_block *sb, char *options, int is_vfat, 1107 int silent, int *debug, struct fat_mount_options *opts) 1108 { 1109 char *p; 1110 substring_t args[MAX_OPT_ARGS]; 1111 int option; 1112 char *iocharset; 1113 1114 opts->isvfat = is_vfat; 1115 1116 opts->fs_uid = current_uid(); 1117 opts->fs_gid = current_gid(); 1118 opts->fs_fmask = opts->fs_dmask = current_umask(); 1119 opts->allow_utime = -1; 1120 opts->codepage = fat_default_codepage; 1121 opts->iocharset = fat_default_iocharset; 1122 if (is_vfat) { 1123 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; 1124 opts->rodir = 0; 1125 } else { 1126 opts->shortname = 0; 1127 opts->rodir = 1; 1128 } 1129 opts->name_check = 'n'; 1130 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; 1131 opts->unicode_xlate = 0; 1132 opts->numtail = 1; 1133 opts->usefree = opts->nocase = 0; 1134 opts->tz_set = 0; 1135 opts->nfs = 0; 1136 opts->errors = FAT_ERRORS_RO; 1137 *debug = 0; 1138 1139 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; 1140 1141 if (!options) 1142 goto out; 1143 1144 while ((p = strsep(&options, ",")) != NULL) { 1145 int token; 1146 if (!*p) 1147 continue; 1148 1149 token = match_token(p, fat_tokens, args); 1150 if (token == Opt_err) { 1151 if (is_vfat) 1152 token = match_token(p, vfat_tokens, args); 1153 else 1154 token = match_token(p, msdos_tokens, args); 1155 } 1156 switch (token) { 1157 case Opt_check_s: 1158 opts->name_check = 's'; 1159 break; 1160 case Opt_check_r: 1161 opts->name_check = 'r'; 1162 break; 1163 case Opt_check_n: 1164 opts->name_check = 'n'; 1165 break; 1166 case Opt_usefree: 1167 opts->usefree = 1; 1168 break; 1169 case Opt_nocase: 1170 if (!is_vfat) 1171 opts->nocase = 1; 1172 else { 1173 /* for backward compatibility */ 1174 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1175 | VFAT_SFN_CREATE_WIN95; 1176 } 1177 break; 1178 case Opt_quiet: 1179 opts->quiet = 1; 1180 break; 1181 case Opt_showexec: 1182 opts->showexec = 1; 1183 break; 1184 case Opt_debug: 1185 *debug = 1; 1186 break; 1187 case Opt_immutable: 1188 opts->sys_immutable = 1; 1189 break; 1190 case Opt_uid: 1191 if (match_int(&args[0], &option)) 1192 return -EINVAL; 1193 opts->fs_uid = make_kuid(current_user_ns(), option); 1194 if (!uid_valid(opts->fs_uid)) 1195 return -EINVAL; 1196 break; 1197 case Opt_gid: 1198 if (match_int(&args[0], &option)) 1199 return -EINVAL; 1200 opts->fs_gid = make_kgid(current_user_ns(), option); 1201 if (!gid_valid(opts->fs_gid)) 1202 return -EINVAL; 1203 break; 1204 case Opt_umask: 1205 if (match_octal(&args[0], &option)) 1206 return -EINVAL; 1207 opts->fs_fmask = opts->fs_dmask = option; 1208 break; 1209 case Opt_dmask: 1210 if (match_octal(&args[0], &option)) 1211 return -EINVAL; 1212 opts->fs_dmask = option; 1213 break; 1214 case Opt_fmask: 1215 if (match_octal(&args[0], &option)) 1216 return -EINVAL; 1217 opts->fs_fmask = option; 1218 break; 1219 case Opt_allow_utime: 1220 if (match_octal(&args[0], &option)) 1221 return -EINVAL; 1222 opts->allow_utime = option & (S_IWGRP | S_IWOTH); 1223 break; 1224 case Opt_codepage: 1225 if (match_int(&args[0], &option)) 1226 return -EINVAL; 1227 opts->codepage = option; 1228 break; 1229 case Opt_flush: 1230 opts->flush = 1; 1231 break; 1232 case Opt_time_offset: 1233 if (match_int(&args[0], &option)) 1234 return -EINVAL; 1235 /* 1236 * GMT+-12 zones may have DST corrections so at least 1237 * 13 hours difference is needed. Make the limit 24 1238 * just in case someone invents something unusual. 1239 */ 1240 if (option < -24 * 60 || option > 24 * 60) 1241 return -EINVAL; 1242 opts->tz_set = 1; 1243 opts->time_offset = option; 1244 break; 1245 case Opt_tz_utc: 1246 opts->tz_set = 1; 1247 opts->time_offset = 0; 1248 break; 1249 case Opt_err_cont: 1250 opts->errors = FAT_ERRORS_CONT; 1251 break; 1252 case Opt_err_panic: 1253 opts->errors = FAT_ERRORS_PANIC; 1254 break; 1255 case Opt_err_ro: 1256 opts->errors = FAT_ERRORS_RO; 1257 break; 1258 case Opt_nfs_stale_rw: 1259 opts->nfs = FAT_NFS_STALE_RW; 1260 break; 1261 case Opt_nfs_nostale_ro: 1262 opts->nfs = FAT_NFS_NOSTALE_RO; 1263 break; 1264 case Opt_dos1xfloppy: 1265 opts->dos1xfloppy = 1; 1266 break; 1267 1268 /* msdos specific */ 1269 case Opt_dots: 1270 opts->dotsOK = 1; 1271 break; 1272 case Opt_nodots: 1273 opts->dotsOK = 0; 1274 break; 1275 1276 /* vfat specific */ 1277 case Opt_charset: 1278 if (opts->iocharset != fat_default_iocharset) 1279 kfree(opts->iocharset); 1280 iocharset = match_strdup(&args[0]); 1281 if (!iocharset) 1282 return -ENOMEM; 1283 opts->iocharset = iocharset; 1284 break; 1285 case Opt_shortname_lower: 1286 opts->shortname = VFAT_SFN_DISPLAY_LOWER 1287 | VFAT_SFN_CREATE_WIN95; 1288 break; 1289 case Opt_shortname_win95: 1290 opts->shortname = VFAT_SFN_DISPLAY_WIN95 1291 | VFAT_SFN_CREATE_WIN95; 1292 break; 1293 case Opt_shortname_winnt: 1294 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1295 | VFAT_SFN_CREATE_WINNT; 1296 break; 1297 case Opt_shortname_mixed: 1298 opts->shortname = VFAT_SFN_DISPLAY_WINNT 1299 | VFAT_SFN_CREATE_WIN95; 1300 break; 1301 case Opt_utf8_no: /* 0 or no or false */ 1302 opts->utf8 = 0; 1303 break; 1304 case Opt_utf8_yes: /* empty or 1 or yes or true */ 1305 opts->utf8 = 1; 1306 break; 1307 case Opt_uni_xl_no: /* 0 or no or false */ 1308 opts->unicode_xlate = 0; 1309 break; 1310 case Opt_uni_xl_yes: /* empty or 1 or yes or true */ 1311 opts->unicode_xlate = 1; 1312 break; 1313 case Opt_nonumtail_no: /* 0 or no or false */ 1314 opts->numtail = 1; /* negated option */ 1315 break; 1316 case Opt_nonumtail_yes: /* empty or 1 or yes or true */ 1317 opts->numtail = 0; /* negated option */ 1318 break; 1319 case Opt_rodir: 1320 opts->rodir = 1; 1321 break; 1322 case Opt_discard: 1323 opts->discard = 1; 1324 break; 1325 1326 /* obsolete mount options */ 1327 case Opt_obsolete: 1328 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " 1329 "not supported now", p); 1330 break; 1331 /* unknown option */ 1332 default: 1333 if (!silent) { 1334 fat_msg(sb, KERN_ERR, 1335 "Unrecognized mount option \"%s\" " 1336 "or missing value", p); 1337 } 1338 return -EINVAL; 1339 } 1340 } 1341 1342 out: 1343 /* UTF-8 doesn't provide FAT semantics */ 1344 if (!strcmp(opts->iocharset, "utf8")) { 1345 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" 1346 " for FAT filesystems, filesystem will be " 1347 "case sensitive!"); 1348 } 1349 1350 /* If user doesn't specify allow_utime, it's initialized from dmask. */ 1351 if (opts->allow_utime == (unsigned short)-1) 1352 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); 1353 if (opts->unicode_xlate) 1354 opts->utf8 = 0; 1355 if (opts->nfs == FAT_NFS_NOSTALE_RO) { 1356 sb->s_flags |= SB_RDONLY; 1357 sb->s_export_op = &fat_export_ops_nostale; 1358 } 1359 1360 return 0; 1361 } 1362 1363 static void fat_dummy_inode_init(struct inode *inode) 1364 { 1365 /* Initialize this dummy inode to work as no-op. */ 1366 MSDOS_I(inode)->mmu_private = 0; 1367 MSDOS_I(inode)->i_start = 0; 1368 MSDOS_I(inode)->i_logstart = 0; 1369 MSDOS_I(inode)->i_attrs = 0; 1370 MSDOS_I(inode)->i_pos = 0; 1371 } 1372 1373 static int fat_read_root(struct inode *inode) 1374 { 1375 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 1376 int error; 1377 1378 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; 1379 inode->i_uid = sbi->options.fs_uid; 1380 inode->i_gid = sbi->options.fs_gid; 1381 inode_inc_iversion(inode); 1382 inode->i_generation = 0; 1383 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); 1384 inode->i_op = sbi->dir_ops; 1385 inode->i_fop = &fat_dir_operations; 1386 if (sbi->fat_bits == 32) { 1387 MSDOS_I(inode)->i_start = sbi->root_cluster; 1388 error = fat_calc_dir_size(inode); 1389 if (error < 0) 1390 return error; 1391 } else { 1392 MSDOS_I(inode)->i_start = 0; 1393 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); 1394 } 1395 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 1396 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 1397 MSDOS_I(inode)->i_logstart = 0; 1398 MSDOS_I(inode)->mmu_private = inode->i_size; 1399 1400 fat_save_attrs(inode, ATTR_DIR); 1401 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; 1402 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; 1403 set_nlink(inode, fat_subdirs(inode)+2); 1404 1405 return 0; 1406 } 1407 1408 static unsigned long calc_fat_clusters(struct super_block *sb) 1409 { 1410 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1411 1412 /* Divide first to avoid overflow */ 1413 if (sbi->fat_bits != 12) { 1414 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; 1415 return ent_per_sec * sbi->fat_length; 1416 } 1417 1418 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; 1419 } 1420 1421 static bool fat_bpb_is_zero(struct fat_boot_sector *b) 1422 { 1423 if (get_unaligned_le16(&b->sector_size)) 1424 return false; 1425 if (b->sec_per_clus) 1426 return false; 1427 if (b->reserved) 1428 return false; 1429 if (b->fats) 1430 return false; 1431 if (get_unaligned_le16(&b->dir_entries)) 1432 return false; 1433 if (get_unaligned_le16(&b->sectors)) 1434 return false; 1435 if (b->media) 1436 return false; 1437 if (b->fat_length) 1438 return false; 1439 if (b->secs_track) 1440 return false; 1441 if (b->heads) 1442 return false; 1443 return true; 1444 } 1445 1446 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, 1447 int silent, struct fat_bios_param_block *bpb) 1448 { 1449 int error = -EINVAL; 1450 1451 /* Read in BPB ... */ 1452 memset(bpb, 0, sizeof(*bpb)); 1453 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); 1454 bpb->fat_sec_per_clus = b->sec_per_clus; 1455 bpb->fat_reserved = le16_to_cpu(b->reserved); 1456 bpb->fat_fats = b->fats; 1457 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); 1458 bpb->fat_sectors = get_unaligned_le16(&b->sectors); 1459 bpb->fat_fat_length = le16_to_cpu(b->fat_length); 1460 bpb->fat_total_sect = le32_to_cpu(b->total_sect); 1461 1462 bpb->fat16_state = b->fat16.state; 1463 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); 1464 1465 bpb->fat32_length = le32_to_cpu(b->fat32.length); 1466 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); 1467 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); 1468 bpb->fat32_state = b->fat32.state; 1469 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); 1470 1471 /* Validate this looks like a FAT filesystem BPB */ 1472 if (!bpb->fat_reserved) { 1473 if (!silent) 1474 fat_msg(sb, KERN_ERR, 1475 "bogus number of reserved sectors"); 1476 goto out; 1477 } 1478 if (!bpb->fat_fats) { 1479 if (!silent) 1480 fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); 1481 goto out; 1482 } 1483 1484 /* 1485 * Earlier we checked here that b->secs_track and b->head are nonzero, 1486 * but it turns out valid FAT filesystems can have zero there. 1487 */ 1488 1489 if (!fat_valid_media(b->media)) { 1490 if (!silent) 1491 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", 1492 (unsigned)b->media); 1493 goto out; 1494 } 1495 1496 if (!is_power_of_2(bpb->fat_sector_size) 1497 || (bpb->fat_sector_size < 512) 1498 || (bpb->fat_sector_size > 4096)) { 1499 if (!silent) 1500 fat_msg(sb, KERN_ERR, "bogus logical sector size %u", 1501 (unsigned)bpb->fat_sector_size); 1502 goto out; 1503 } 1504 1505 if (!is_power_of_2(bpb->fat_sec_per_clus)) { 1506 if (!silent) 1507 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", 1508 (unsigned)bpb->fat_sec_per_clus); 1509 goto out; 1510 } 1511 1512 error = 0; 1513 1514 out: 1515 return error; 1516 } 1517 1518 static int fat_read_static_bpb(struct super_block *sb, 1519 struct fat_boot_sector *b, int silent, 1520 struct fat_bios_param_block *bpb) 1521 { 1522 static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; 1523 1524 struct fat_floppy_defaults *fdefaults = NULL; 1525 int error = -EINVAL; 1526 sector_t bd_sects; 1527 unsigned i; 1528 1529 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; 1530 1531 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ 1532 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { 1533 if (!silent) 1534 fat_msg(sb, KERN_ERR, 1535 "%s; no bootstrapping code", notdos1x); 1536 goto out; 1537 } 1538 1539 /* 1540 * If any value in this region is non-zero, it isn't archaic 1541 * DOS. 1542 */ 1543 if (!fat_bpb_is_zero(b)) { 1544 if (!silent) 1545 fat_msg(sb, KERN_ERR, 1546 "%s; DOS 2.x BPB is non-zero", notdos1x); 1547 goto out; 1548 } 1549 1550 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { 1551 if (floppy_defaults[i].nr_sectors == bd_sects) { 1552 fdefaults = &floppy_defaults[i]; 1553 break; 1554 } 1555 } 1556 1557 if (fdefaults == NULL) { 1558 if (!silent) 1559 fat_msg(sb, KERN_WARNING, 1560 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", 1561 (u64)bd_sects); 1562 goto out; 1563 } 1564 1565 if (!silent) 1566 fat_msg(sb, KERN_INFO, 1567 "This looks like a DOS 1.x volume; assuming default BPB values"); 1568 1569 memset(bpb, 0, sizeof(*bpb)); 1570 bpb->fat_sector_size = SECTOR_SIZE; 1571 bpb->fat_sec_per_clus = fdefaults->sec_per_clus; 1572 bpb->fat_reserved = 1; 1573 bpb->fat_fats = 2; 1574 bpb->fat_dir_entries = fdefaults->dir_entries; 1575 bpb->fat_sectors = fdefaults->nr_sectors; 1576 bpb->fat_fat_length = fdefaults->fat_length; 1577 1578 error = 0; 1579 1580 out: 1581 return error; 1582 } 1583 1584 /* 1585 * Read the super block of an MS-DOS FS. 1586 */ 1587 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 1588 void (*setup)(struct super_block *)) 1589 { 1590 struct inode *root_inode = NULL, *fat_inode = NULL; 1591 struct inode *fsinfo_inode = NULL; 1592 struct buffer_head *bh; 1593 struct fat_bios_param_block bpb; 1594 struct msdos_sb_info *sbi; 1595 u16 logical_sector_size; 1596 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; 1597 int debug; 1598 long error; 1599 char buf[50]; 1600 1601 /* 1602 * GFP_KERNEL is ok here, because while we do hold the 1603 * superblock lock, memory pressure can't call back into 1604 * the filesystem, since we're only just about to mount 1605 * it and have no inodes etc active! 1606 */ 1607 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); 1608 if (!sbi) 1609 return -ENOMEM; 1610 sb->s_fs_info = sbi; 1611 1612 sb->s_flags |= SB_NODIRATIME; 1613 sb->s_magic = MSDOS_SUPER_MAGIC; 1614 sb->s_op = &fat_sops; 1615 sb->s_export_op = &fat_export_ops; 1616 mutex_init(&sbi->nfs_build_inode_lock); 1617 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, 1618 DEFAULT_RATELIMIT_BURST); 1619 1620 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); 1621 if (error) 1622 goto out_fail; 1623 1624 setup(sb); /* flavour-specific stuff that needs options */ 1625 1626 error = -EIO; 1627 sb_min_blocksize(sb, 512); 1628 bh = sb_bread(sb, 0); 1629 if (bh == NULL) { 1630 fat_msg(sb, KERN_ERR, "unable to read boot sector"); 1631 goto out_fail; 1632 } 1633 1634 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, 1635 &bpb); 1636 if (error == -EINVAL && sbi->options.dos1xfloppy) 1637 error = fat_read_static_bpb(sb, 1638 (struct fat_boot_sector *)bh->b_data, silent, &bpb); 1639 brelse(bh); 1640 1641 if (error == -EINVAL) 1642 goto out_invalid; 1643 else if (error) 1644 goto out_fail; 1645 1646 logical_sector_size = bpb.fat_sector_size; 1647 sbi->sec_per_clus = bpb.fat_sec_per_clus; 1648 1649 error = -EIO; 1650 if (logical_sector_size < sb->s_blocksize) { 1651 fat_msg(sb, KERN_ERR, "logical sector size too small for device" 1652 " (logical sector size = %u)", logical_sector_size); 1653 goto out_fail; 1654 } 1655 1656 if (logical_sector_size > sb->s_blocksize) { 1657 struct buffer_head *bh_resize; 1658 1659 if (!sb_set_blocksize(sb, logical_sector_size)) { 1660 fat_msg(sb, KERN_ERR, "unable to set blocksize %u", 1661 logical_sector_size); 1662 goto out_fail; 1663 } 1664 1665 /* Verify that the larger boot sector is fully readable */ 1666 bh_resize = sb_bread(sb, 0); 1667 if (bh_resize == NULL) { 1668 fat_msg(sb, KERN_ERR, "unable to read boot sector" 1669 " (logical sector size = %lu)", 1670 sb->s_blocksize); 1671 goto out_fail; 1672 } 1673 brelse(bh_resize); 1674 } 1675 1676 mutex_init(&sbi->s_lock); 1677 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; 1678 sbi->cluster_bits = ffs(sbi->cluster_size) - 1; 1679 sbi->fats = bpb.fat_fats; 1680 sbi->fat_bits = 0; /* Don't know yet */ 1681 sbi->fat_start = bpb.fat_reserved; 1682 sbi->fat_length = bpb.fat_fat_length; 1683 sbi->root_cluster = 0; 1684 sbi->free_clusters = -1; /* Don't know yet */ 1685 sbi->free_clus_valid = 0; 1686 sbi->prev_free = FAT_START_ENT; 1687 sb->s_maxbytes = 0xffffffff; 1688 1689 if (!sbi->fat_length && bpb.fat32_length) { 1690 struct fat_boot_fsinfo *fsinfo; 1691 struct buffer_head *fsinfo_bh; 1692 1693 /* Must be FAT32 */ 1694 sbi->fat_bits = 32; 1695 sbi->fat_length = bpb.fat32_length; 1696 sbi->root_cluster = bpb.fat32_root_cluster; 1697 1698 /* MC - if info_sector is 0, don't multiply by 0 */ 1699 sbi->fsinfo_sector = bpb.fat32_info_sector; 1700 if (sbi->fsinfo_sector == 0) 1701 sbi->fsinfo_sector = 1; 1702 1703 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); 1704 if (fsinfo_bh == NULL) { 1705 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" 1706 " (sector = %lu)", sbi->fsinfo_sector); 1707 goto out_fail; 1708 } 1709 1710 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; 1711 if (!IS_FSINFO(fsinfo)) { 1712 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " 1713 "0x%08x, 0x%08x (sector = %lu)", 1714 le32_to_cpu(fsinfo->signature1), 1715 le32_to_cpu(fsinfo->signature2), 1716 sbi->fsinfo_sector); 1717 } else { 1718 if (sbi->options.usefree) 1719 sbi->free_clus_valid = 1; 1720 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); 1721 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); 1722 } 1723 1724 brelse(fsinfo_bh); 1725 } 1726 1727 /* interpret volume ID as a little endian 32 bit integer */ 1728 if (sbi->fat_bits == 32) 1729 sbi->vol_id = bpb.fat32_vol_id; 1730 else /* fat 16 or 12 */ 1731 sbi->vol_id = bpb.fat16_vol_id; 1732 1733 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); 1734 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; 1735 1736 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; 1737 sbi->dir_entries = bpb.fat_dir_entries; 1738 if (sbi->dir_entries & (sbi->dir_per_block - 1)) { 1739 if (!silent) 1740 fat_msg(sb, KERN_ERR, "bogus number of directory entries" 1741 " (%u)", sbi->dir_entries); 1742 goto out_invalid; 1743 } 1744 1745 rootdir_sectors = sbi->dir_entries 1746 * sizeof(struct msdos_dir_entry) / sb->s_blocksize; 1747 sbi->data_start = sbi->dir_start + rootdir_sectors; 1748 total_sectors = bpb.fat_sectors; 1749 if (total_sectors == 0) 1750 total_sectors = bpb.fat_total_sect; 1751 1752 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; 1753 1754 if (sbi->fat_bits != 32) 1755 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; 1756 1757 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ 1758 if (sbi->fat_bits == 32) 1759 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; 1760 else /* fat 16 or 12 */ 1761 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; 1762 1763 /* check that FAT table does not overflow */ 1764 fat_clusters = calc_fat_clusters(sb); 1765 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); 1766 if (total_clusters > MAX_FAT(sb)) { 1767 if (!silent) 1768 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", 1769 total_clusters); 1770 goto out_invalid; 1771 } 1772 1773 sbi->max_cluster = total_clusters + FAT_START_ENT; 1774 /* check the free_clusters, it's not necessarily correct */ 1775 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) 1776 sbi->free_clusters = -1; 1777 /* check the prev_free, it's not necessarily correct */ 1778 sbi->prev_free %= sbi->max_cluster; 1779 if (sbi->prev_free < FAT_START_ENT) 1780 sbi->prev_free = FAT_START_ENT; 1781 1782 /* set up enough so that it can read an inode */ 1783 fat_hash_init(sb); 1784 dir_hash_init(sb); 1785 fat_ent_access_init(sb); 1786 1787 /* 1788 * The low byte of FAT's first entry must have same value with 1789 * media-field. But in real world, too many devices is 1790 * writing wrong value. So, removed that validity check. 1791 * 1792 * if (FAT_FIRST_ENT(sb, media) != first) 1793 */ 1794 1795 error = -EINVAL; 1796 sprintf(buf, "cp%d", sbi->options.codepage); 1797 sbi->nls_disk = load_nls(buf); 1798 if (!sbi->nls_disk) { 1799 fat_msg(sb, KERN_ERR, "codepage %s not found", buf); 1800 goto out_fail; 1801 } 1802 1803 /* FIXME: utf8 is using iocharset for upper/lower conversion */ 1804 if (sbi->options.isvfat) { 1805 sbi->nls_io = load_nls(sbi->options.iocharset); 1806 if (!sbi->nls_io) { 1807 fat_msg(sb, KERN_ERR, "IO charset %s not found", 1808 sbi->options.iocharset); 1809 goto out_fail; 1810 } 1811 } 1812 1813 error = -ENOMEM; 1814 fat_inode = new_inode(sb); 1815 if (!fat_inode) 1816 goto out_fail; 1817 fat_dummy_inode_init(fat_inode); 1818 sbi->fat_inode = fat_inode; 1819 1820 fsinfo_inode = new_inode(sb); 1821 if (!fsinfo_inode) 1822 goto out_fail; 1823 fat_dummy_inode_init(fsinfo_inode); 1824 fsinfo_inode->i_ino = MSDOS_FSINFO_INO; 1825 sbi->fsinfo_inode = fsinfo_inode; 1826 insert_inode_hash(fsinfo_inode); 1827 1828 root_inode = new_inode(sb); 1829 if (!root_inode) 1830 goto out_fail; 1831 root_inode->i_ino = MSDOS_ROOT_INO; 1832 inode_set_iversion(root_inode, 1); 1833 error = fat_read_root(root_inode); 1834 if (error < 0) { 1835 iput(root_inode); 1836 goto out_fail; 1837 } 1838 error = -ENOMEM; 1839 insert_inode_hash(root_inode); 1840 fat_attach(root_inode, 0); 1841 sb->s_root = d_make_root(root_inode); 1842 if (!sb->s_root) { 1843 fat_msg(sb, KERN_ERR, "get root inode failed"); 1844 goto out_fail; 1845 } 1846 1847 if (sbi->options.discard) { 1848 struct request_queue *q = bdev_get_queue(sb->s_bdev); 1849 if (!blk_queue_discard(q)) 1850 fat_msg(sb, KERN_WARNING, 1851 "mounting with \"discard\" option, but " 1852 "the device does not support discard"); 1853 } 1854 1855 fat_set_state(sb, 1, 0); 1856 return 0; 1857 1858 out_invalid: 1859 error = -EINVAL; 1860 if (!silent) 1861 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); 1862 1863 out_fail: 1864 if (fsinfo_inode) 1865 iput(fsinfo_inode); 1866 if (fat_inode) 1867 iput(fat_inode); 1868 unload_nls(sbi->nls_io); 1869 unload_nls(sbi->nls_disk); 1870 if (sbi->options.iocharset != fat_default_iocharset) 1871 kfree(sbi->options.iocharset); 1872 sb->s_fs_info = NULL; 1873 kfree(sbi); 1874 return error; 1875 } 1876 1877 EXPORT_SYMBOL_GPL(fat_fill_super); 1878 1879 /* 1880 * helper function for fat_flush_inodes. This writes both the inode 1881 * and the file data blocks, waiting for in flight data blocks before 1882 * the start of the call. It does not wait for any io started 1883 * during the call 1884 */ 1885 static int writeback_inode(struct inode *inode) 1886 { 1887 1888 int ret; 1889 1890 /* if we used wait=1, sync_inode_metadata waits for the io for the 1891 * inode to finish. So wait=0 is sent down to sync_inode_metadata 1892 * and filemap_fdatawrite is used for the data blocks 1893 */ 1894 ret = sync_inode_metadata(inode, 0); 1895 if (!ret) 1896 ret = filemap_fdatawrite(inode->i_mapping); 1897 return ret; 1898 } 1899 1900 /* 1901 * write data and metadata corresponding to i1 and i2. The io is 1902 * started but we do not wait for any of it to finish. 1903 * 1904 * filemap_flush is used for the block device, so if there is a dirty 1905 * page for a block already in flight, we will not wait and start the 1906 * io over again 1907 */ 1908 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) 1909 { 1910 int ret = 0; 1911 if (!MSDOS_SB(sb)->options.flush) 1912 return 0; 1913 if (i1) 1914 ret = writeback_inode(i1); 1915 if (!ret && i2) 1916 ret = writeback_inode(i2); 1917 if (!ret) { 1918 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 1919 ret = filemap_flush(mapping); 1920 } 1921 return ret; 1922 } 1923 EXPORT_SYMBOL_GPL(fat_flush_inodes); 1924 1925 static int __init init_fat_fs(void) 1926 { 1927 int err; 1928 1929 err = fat_cache_init(); 1930 if (err) 1931 return err; 1932 1933 err = fat_init_inodecache(); 1934 if (err) 1935 goto failed; 1936 1937 return 0; 1938 1939 failed: 1940 fat_cache_destroy(); 1941 return err; 1942 } 1943 1944 static void __exit exit_fat_fs(void) 1945 { 1946 fat_cache_destroy(); 1947 fat_destroy_inodecache(); 1948 } 1949 1950 module_init(init_fat_fs) 1951 module_exit(exit_fat_fs) 1952 1953 MODULE_LICENSE("GPL"); 1954