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