| 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 | if (!phys) { |
| 162 | fat_fs_error(sb, |
| 163 | "invalid FAT chain (i_pos %lld, last_block %llu)", |
| 164 | MSDOS_I(inode)->i_pos, |
| 165 | (unsigned long long)last_block); |
| 166 | return -EIO; |
| 167 | } |
| 168 | |
| 169 | BUG_ON(*max_blocks != mapped_blocks); |
| 170 | set_buffer_new(bh_result); |
| 171 | map_bh(bh_result, sb, phys); |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | static int fat_get_block(struct inode *inode, sector_t iblock, |
| 177 | struct buffer_head *bh_result, int create) |
| 178 | { |
| 179 | struct super_block *sb = inode->i_sb; |
| 180 | unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; |
| 181 | int err; |
| 182 | |
| 183 | err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); |
| 184 | if (err) |
| 185 | return err; |
| 186 | bh_result->b_size = max_blocks << sb->s_blocksize_bits; |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | static int fat_writepage(struct page *page, struct writeback_control *wbc) |
| 191 | { |
| 192 | return block_write_full_page(page, fat_get_block, wbc); |
| 193 | } |
| 194 | |
| 195 | static int fat_writepages(struct address_space *mapping, |
| 196 | struct writeback_control *wbc) |
| 197 | { |
| 198 | return mpage_writepages(mapping, wbc, fat_get_block); |
| 199 | } |
| 200 | |
| 201 | static int fat_readpage(struct file *file, struct page *page) |
| 202 | { |
| 203 | return mpage_readpage(page, fat_get_block); |
| 204 | } |
| 205 | |
| 206 | static int fat_readpages(struct file *file, struct address_space *mapping, |
| 207 | struct list_head *pages, unsigned nr_pages) |
| 208 | { |
| 209 | return mpage_readpages(mapping, pages, nr_pages, fat_get_block); |
| 210 | } |
| 211 | |
| 212 | static void fat_write_failed(struct address_space *mapping, loff_t to) |
| 213 | { |
| 214 | struct inode *inode = mapping->host; |
| 215 | |
| 216 | if (to > inode->i_size) { |
| 217 | truncate_pagecache(inode, inode->i_size); |
| 218 | fat_truncate_blocks(inode, inode->i_size); |
| 219 | } |
| 220 | } |
| 221 | |
| 222 | static int fat_write_begin(struct file *file, struct address_space *mapping, |
| 223 | loff_t pos, unsigned len, unsigned flags, |
| 224 | struct page **pagep, void **fsdata) |
| 225 | { |
| 226 | int err; |
| 227 | |
| 228 | *pagep = NULL; |
| 229 | err = cont_write_begin(file, mapping, pos, len, flags, |
| 230 | pagep, fsdata, fat_get_block, |
| 231 | &MSDOS_I(mapping->host)->mmu_private); |
| 232 | if (err < 0) |
| 233 | fat_write_failed(mapping, pos + len); |
| 234 | return err; |
| 235 | } |
| 236 | |
| 237 | static int fat_write_end(struct file *file, struct address_space *mapping, |
| 238 | loff_t pos, unsigned len, unsigned copied, |
| 239 | struct page *pagep, void *fsdata) |
| 240 | { |
| 241 | struct inode *inode = mapping->host; |
| 242 | int err; |
| 243 | err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); |
| 244 | if (err < len) |
| 245 | fat_write_failed(mapping, pos + len); |
| 246 | if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { |
| 247 | inode->i_mtime = inode->i_ctime = current_time(inode); |
| 248 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; |
| 249 | mark_inode_dirty(inode); |
| 250 | } |
| 251 | return err; |
| 252 | } |
| 253 | |
| 254 | static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
| 255 | { |
| 256 | struct file *file = iocb->ki_filp; |
| 257 | struct address_space *mapping = file->f_mapping; |
| 258 | struct inode *inode = mapping->host; |
| 259 | size_t count = iov_iter_count(iter); |
| 260 | loff_t offset = iocb->ki_pos; |
| 261 | ssize_t ret; |
| 262 | |
| 263 | if (iov_iter_rw(iter) == WRITE) { |
| 264 | /* |
| 265 | * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), |
| 266 | * so we need to update the ->mmu_private to block boundary. |
| 267 | * |
| 268 | * But we must fill the remaining area or hole by nul for |
| 269 | * updating ->mmu_private. |
| 270 | * |
| 271 | * Return 0, and fallback to normal buffered write. |
| 272 | */ |
| 273 | loff_t size = offset + count; |
| 274 | if (MSDOS_I(inode)->mmu_private < size) |
| 275 | return 0; |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * FAT need to use the DIO_LOCKING for avoiding the race |
| 280 | * condition of fat_get_block() and ->truncate(). |
| 281 | */ |
| 282 | ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); |
| 283 | if (ret < 0 && iov_iter_rw(iter) == WRITE) |
| 284 | fat_write_failed(mapping, offset + count); |
| 285 | |
| 286 | return ret; |
| 287 | } |
| 288 | |
| 289 | static int fat_get_block_bmap(struct inode *inode, sector_t iblock, |
| 290 | struct buffer_head *bh_result, int create) |
| 291 | { |
| 292 | struct super_block *sb = inode->i_sb; |
| 293 | unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; |
| 294 | int err; |
| 295 | sector_t bmap; |
| 296 | unsigned long mapped_blocks; |
| 297 | |
| 298 | BUG_ON(create != 0); |
| 299 | |
| 300 | err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); |
| 301 | if (err) |
| 302 | return err; |
| 303 | |
| 304 | if (bmap) { |
| 305 | map_bh(bh_result, sb, bmap); |
| 306 | max_blocks = min(mapped_blocks, max_blocks); |
| 307 | } |
| 308 | |
| 309 | bh_result->b_size = max_blocks << sb->s_blocksize_bits; |
| 310 | |
| 311 | return 0; |
| 312 | } |
| 313 | |
| 314 | static sector_t _fat_bmap(struct address_space *mapping, sector_t block) |
| 315 | { |
| 316 | sector_t blocknr; |
| 317 | |
| 318 | /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ |
| 319 | down_read(&MSDOS_I(mapping->host)->truncate_lock); |
| 320 | blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); |
| 321 | up_read(&MSDOS_I(mapping->host)->truncate_lock); |
| 322 | |
| 323 | return blocknr; |
| 324 | } |
| 325 | |
| 326 | /* |
| 327 | * fat_block_truncate_page() zeroes out a mapping from file offset `from' |
| 328 | * up to the end of the block which corresponds to `from'. |
| 329 | * This is required during truncate to physically zeroout the tail end |
| 330 | * of that block so it doesn't yield old data if the file is later grown. |
| 331 | * Also, avoid causing failure from fsx for cases of "data past EOF" |
| 332 | */ |
| 333 | int fat_block_truncate_page(struct inode *inode, loff_t from) |
| 334 | { |
| 335 | return block_truncate_page(inode->i_mapping, from, fat_get_block); |
| 336 | } |
| 337 | |
| 338 | static const struct address_space_operations fat_aops = { |
| 339 | .readpage = fat_readpage, |
| 340 | .readpages = fat_readpages, |
| 341 | .writepage = fat_writepage, |
| 342 | .writepages = fat_writepages, |
| 343 | .write_begin = fat_write_begin, |
| 344 | .write_end = fat_write_end, |
| 345 | .direct_IO = fat_direct_IO, |
| 346 | .bmap = _fat_bmap |
| 347 | }; |
| 348 | |
| 349 | /* |
| 350 | * New FAT inode stuff. We do the following: |
| 351 | * a) i_ino is constant and has nothing with on-disk location. |
| 352 | * b) FAT manages its own cache of directory entries. |
| 353 | * c) *This* cache is indexed by on-disk location. |
| 354 | * d) inode has an associated directory entry, all right, but |
| 355 | * it may be unhashed. |
| 356 | * e) currently entries are stored within struct inode. That should |
| 357 | * change. |
| 358 | * f) we deal with races in the following way: |
| 359 | * 1. readdir() and lookup() do FAT-dir-cache lookup. |
| 360 | * 2. rename() unhashes the F-d-c entry and rehashes it in |
| 361 | * a new place. |
| 362 | * 3. unlink() and rmdir() unhash F-d-c entry. |
| 363 | * 4. fat_write_inode() checks whether the thing is unhashed. |
| 364 | * If it is we silently return. If it isn't we do bread(), |
| 365 | * check if the location is still valid and retry if it |
| 366 | * isn't. Otherwise we do changes. |
| 367 | * 5. Spinlock is used to protect hash/unhash/location check/lookup |
| 368 | * 6. fat_evict_inode() unhashes the F-d-c entry. |
| 369 | * 7. lookup() and readdir() do igrab() if they find a F-d-c entry |
| 370 | * and consider negative result as cache miss. |
| 371 | */ |
| 372 | |
| 373 | static void fat_hash_init(struct super_block *sb) |
| 374 | { |
| 375 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 376 | int i; |
| 377 | |
| 378 | spin_lock_init(&sbi->inode_hash_lock); |
| 379 | for (i = 0; i < FAT_HASH_SIZE; i++) |
| 380 | INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); |
| 381 | } |
| 382 | |
| 383 | static inline unsigned long fat_hash(loff_t i_pos) |
| 384 | { |
| 385 | return hash_32(i_pos, FAT_HASH_BITS); |
| 386 | } |
| 387 | |
| 388 | static void dir_hash_init(struct super_block *sb) |
| 389 | { |
| 390 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 391 | int i; |
| 392 | |
| 393 | spin_lock_init(&sbi->dir_hash_lock); |
| 394 | for (i = 0; i < FAT_HASH_SIZE; i++) |
| 395 | INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); |
| 396 | } |
| 397 | |
| 398 | void fat_attach(struct inode *inode, loff_t i_pos) |
| 399 | { |
| 400 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| 401 | |
| 402 | if (inode->i_ino != MSDOS_ROOT_INO) { |
| 403 | struct hlist_head *head = sbi->inode_hashtable |
| 404 | + fat_hash(i_pos); |
| 405 | |
| 406 | spin_lock(&sbi->inode_hash_lock); |
| 407 | MSDOS_I(inode)->i_pos = i_pos; |
| 408 | hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); |
| 409 | spin_unlock(&sbi->inode_hash_lock); |
| 410 | } |
| 411 | |
| 412 | /* If NFS support is enabled, cache the mapping of start cluster |
| 413 | * to directory inode. This is used during reconnection of |
| 414 | * dentries to the filesystem root. |
| 415 | */ |
| 416 | if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { |
| 417 | struct hlist_head *d_head = sbi->dir_hashtable; |
| 418 | d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); |
| 419 | |
| 420 | spin_lock(&sbi->dir_hash_lock); |
| 421 | hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); |
| 422 | spin_unlock(&sbi->dir_hash_lock); |
| 423 | } |
| 424 | } |
| 425 | EXPORT_SYMBOL_GPL(fat_attach); |
| 426 | |
| 427 | void fat_detach(struct inode *inode) |
| 428 | { |
| 429 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| 430 | spin_lock(&sbi->inode_hash_lock); |
| 431 | MSDOS_I(inode)->i_pos = 0; |
| 432 | hlist_del_init(&MSDOS_I(inode)->i_fat_hash); |
| 433 | spin_unlock(&sbi->inode_hash_lock); |
| 434 | |
| 435 | if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { |
| 436 | spin_lock(&sbi->dir_hash_lock); |
| 437 | hlist_del_init(&MSDOS_I(inode)->i_dir_hash); |
| 438 | spin_unlock(&sbi->dir_hash_lock); |
| 439 | } |
| 440 | } |
| 441 | EXPORT_SYMBOL_GPL(fat_detach); |
| 442 | |
| 443 | struct inode *fat_iget(struct super_block *sb, loff_t i_pos) |
| 444 | { |
| 445 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 446 | struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); |
| 447 | struct msdos_inode_info *i; |
| 448 | struct inode *inode = NULL; |
| 449 | |
| 450 | spin_lock(&sbi->inode_hash_lock); |
| 451 | hlist_for_each_entry(i, head, i_fat_hash) { |
| 452 | BUG_ON(i->vfs_inode.i_sb != sb); |
| 453 | if (i->i_pos != i_pos) |
| 454 | continue; |
| 455 | inode = igrab(&i->vfs_inode); |
| 456 | if (inode) |
| 457 | break; |
| 458 | } |
| 459 | spin_unlock(&sbi->inode_hash_lock); |
| 460 | return inode; |
| 461 | } |
| 462 | |
| 463 | static int is_exec(unsigned char *extension) |
| 464 | { |
| 465 | unsigned char exe_extensions[] = "EXECOMBAT", *walk; |
| 466 | |
| 467 | for (walk = exe_extensions; *walk; walk += 3) |
| 468 | if (!strncmp(extension, walk, 3)) |
| 469 | return 1; |
| 470 | return 0; |
| 471 | } |
| 472 | |
| 473 | static int fat_calc_dir_size(struct inode *inode) |
| 474 | { |
| 475 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| 476 | int ret, fclus, dclus; |
| 477 | |
| 478 | inode->i_size = 0; |
| 479 | if (MSDOS_I(inode)->i_start == 0) |
| 480 | return 0; |
| 481 | |
| 482 | ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); |
| 483 | if (ret < 0) |
| 484 | return ret; |
| 485 | inode->i_size = (fclus + 1) << sbi->cluster_bits; |
| 486 | |
| 487 | return 0; |
| 488 | } |
| 489 | |
| 490 | static int fat_validate_dir(struct inode *dir) |
| 491 | { |
| 492 | struct super_block *sb = dir->i_sb; |
| 493 | |
| 494 | if (dir->i_nlink < 2) { |
| 495 | /* Directory should have "."/".." entries at least. */ |
| 496 | fat_fs_error(sb, "corrupted directory (invalid entries)"); |
| 497 | return -EIO; |
| 498 | } |
| 499 | if (MSDOS_I(dir)->i_start == 0 || |
| 500 | MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { |
| 501 | /* Directory should point valid cluster. */ |
| 502 | fat_fs_error(sb, "corrupted directory (invalid i_start)"); |
| 503 | return -EIO; |
| 504 | } |
| 505 | return 0; |
| 506 | } |
| 507 | |
| 508 | /* doesn't deal with root inode */ |
| 509 | int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) |
| 510 | { |
| 511 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| 512 | int error; |
| 513 | |
| 514 | MSDOS_I(inode)->i_pos = 0; |
| 515 | inode->i_uid = sbi->options.fs_uid; |
| 516 | inode->i_gid = sbi->options.fs_gid; |
| 517 | inode_inc_iversion(inode); |
| 518 | inode->i_generation = get_seconds(); |
| 519 | |
| 520 | if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { |
| 521 | inode->i_generation &= ~1; |
| 522 | inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); |
| 523 | inode->i_op = sbi->dir_ops; |
| 524 | inode->i_fop = &fat_dir_operations; |
| 525 | |
| 526 | MSDOS_I(inode)->i_start = fat_get_start(sbi, de); |
| 527 | MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; |
| 528 | error = fat_calc_dir_size(inode); |
| 529 | if (error < 0) |
| 530 | return error; |
| 531 | MSDOS_I(inode)->mmu_private = inode->i_size; |
| 532 | |
| 533 | set_nlink(inode, fat_subdirs(inode)); |
| 534 | |
| 535 | error = fat_validate_dir(inode); |
| 536 | if (error < 0) |
| 537 | return error; |
| 538 | } else { /* not a directory */ |
| 539 | inode->i_generation |= 1; |
| 540 | inode->i_mode = fat_make_mode(sbi, de->attr, |
| 541 | ((sbi->options.showexec && !is_exec(de->name + 8)) |
| 542 | ? S_IRUGO|S_IWUGO : S_IRWXUGO)); |
| 543 | MSDOS_I(inode)->i_start = fat_get_start(sbi, de); |
| 544 | |
| 545 | MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; |
| 546 | inode->i_size = le32_to_cpu(de->size); |
| 547 | inode->i_op = &fat_file_inode_operations; |
| 548 | inode->i_fop = &fat_file_operations; |
| 549 | inode->i_mapping->a_ops = &fat_aops; |
| 550 | MSDOS_I(inode)->mmu_private = inode->i_size; |
| 551 | } |
| 552 | if (de->attr & ATTR_SYS) { |
| 553 | if (sbi->options.sys_immutable) |
| 554 | inode->i_flags |= S_IMMUTABLE; |
| 555 | } |
| 556 | fat_save_attrs(inode, de->attr); |
| 557 | |
| 558 | inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) |
| 559 | & ~((loff_t)sbi->cluster_size - 1)) >> 9; |
| 560 | |
| 561 | fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); |
| 562 | if (sbi->options.isvfat) { |
| 563 | fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, |
| 564 | de->cdate, de->ctime_cs); |
| 565 | fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); |
| 566 | } else |
| 567 | inode->i_ctime = inode->i_atime = inode->i_mtime; |
| 568 | |
| 569 | return 0; |
| 570 | } |
| 571 | |
| 572 | static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) |
| 573 | { |
| 574 | if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) |
| 575 | mutex_lock(&sbi->nfs_build_inode_lock); |
| 576 | } |
| 577 | |
| 578 | static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) |
| 579 | { |
| 580 | if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) |
| 581 | mutex_unlock(&sbi->nfs_build_inode_lock); |
| 582 | } |
| 583 | |
| 584 | struct inode *fat_build_inode(struct super_block *sb, |
| 585 | struct msdos_dir_entry *de, loff_t i_pos) |
| 586 | { |
| 587 | struct inode *inode; |
| 588 | int err; |
| 589 | |
| 590 | fat_lock_build_inode(MSDOS_SB(sb)); |
| 591 | inode = fat_iget(sb, i_pos); |
| 592 | if (inode) |
| 593 | goto out; |
| 594 | inode = new_inode(sb); |
| 595 | if (!inode) { |
| 596 | inode = ERR_PTR(-ENOMEM); |
| 597 | goto out; |
| 598 | } |
| 599 | inode->i_ino = iunique(sb, MSDOS_ROOT_INO); |
| 600 | inode_set_iversion(inode, 1); |
| 601 | err = fat_fill_inode(inode, de); |
| 602 | if (err) { |
| 603 | iput(inode); |
| 604 | inode = ERR_PTR(err); |
| 605 | goto out; |
| 606 | } |
| 607 | fat_attach(inode, i_pos); |
| 608 | insert_inode_hash(inode); |
| 609 | out: |
| 610 | fat_unlock_build_inode(MSDOS_SB(sb)); |
| 611 | return inode; |
| 612 | } |
| 613 | |
| 614 | EXPORT_SYMBOL_GPL(fat_build_inode); |
| 615 | |
| 616 | static int __fat_write_inode(struct inode *inode, int wait); |
| 617 | |
| 618 | static void fat_free_eofblocks(struct inode *inode) |
| 619 | { |
| 620 | /* Release unwritten fallocated blocks on inode eviction. */ |
| 621 | if ((inode->i_blocks << 9) > |
| 622 | round_up(MSDOS_I(inode)->mmu_private, |
| 623 | MSDOS_SB(inode->i_sb)->cluster_size)) { |
| 624 | int err; |
| 625 | |
| 626 | fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); |
| 627 | /* Fallocate results in updating the i_start/iogstart |
| 628 | * for the zero byte file. So, make it return to |
| 629 | * original state during evict and commit it to avoid |
| 630 | * any corruption on the next access to the cluster |
| 631 | * chain for the file. |
| 632 | */ |
| 633 | err = __fat_write_inode(inode, inode_needs_sync(inode)); |
| 634 | if (err) { |
| 635 | fat_msg(inode->i_sb, KERN_WARNING, "Failed to " |
| 636 | "update on disk inode for unused " |
| 637 | "fallocated blocks, inode could be " |
| 638 | "corrupted. Please run fsck"); |
| 639 | } |
| 640 | |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | static void fat_evict_inode(struct inode *inode) |
| 645 | { |
| 646 | truncate_inode_pages_final(&inode->i_data); |
| 647 | if (!inode->i_nlink) { |
| 648 | inode->i_size = 0; |
| 649 | fat_truncate_blocks(inode, 0); |
| 650 | } else |
| 651 | fat_free_eofblocks(inode); |
| 652 | |
| 653 | invalidate_inode_buffers(inode); |
| 654 | clear_inode(inode); |
| 655 | fat_cache_inval_inode(inode); |
| 656 | fat_detach(inode); |
| 657 | } |
| 658 | |
| 659 | static void fat_set_state(struct super_block *sb, |
| 660 | unsigned int set, unsigned int force) |
| 661 | { |
| 662 | struct buffer_head *bh; |
| 663 | struct fat_boot_sector *b; |
| 664 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 665 | |
| 666 | /* do not change any thing if mounted read only */ |
| 667 | if (sb_rdonly(sb) && !force) |
| 668 | return; |
| 669 | |
| 670 | /* do not change state if fs was dirty */ |
| 671 | if (sbi->dirty) { |
| 672 | /* warn only on set (mount). */ |
| 673 | if (set) |
| 674 | fat_msg(sb, KERN_WARNING, "Volume was not properly " |
| 675 | "unmounted. Some data may be corrupt. " |
| 676 | "Please run fsck."); |
| 677 | return; |
| 678 | } |
| 679 | |
| 680 | bh = sb_bread(sb, 0); |
| 681 | if (bh == NULL) { |
| 682 | fat_msg(sb, KERN_ERR, "unable to read boot sector " |
| 683 | "to mark fs as dirty"); |
| 684 | return; |
| 685 | } |
| 686 | |
| 687 | b = (struct fat_boot_sector *) bh->b_data; |
| 688 | |
| 689 | if (sbi->fat_bits == 32) { |
| 690 | if (set) |
| 691 | b->fat32.state |= FAT_STATE_DIRTY; |
| 692 | else |
| 693 | b->fat32.state &= ~FAT_STATE_DIRTY; |
| 694 | } else /* fat 16 and 12 */ { |
| 695 | if (set) |
| 696 | b->fat16.state |= FAT_STATE_DIRTY; |
| 697 | else |
| 698 | b->fat16.state &= ~FAT_STATE_DIRTY; |
| 699 | } |
| 700 | |
| 701 | mark_buffer_dirty(bh); |
| 702 | sync_dirty_buffer(bh); |
| 703 | brelse(bh); |
| 704 | } |
| 705 | |
| 706 | static void fat_reset_iocharset(struct fat_mount_options *opts) |
| 707 | { |
| 708 | if (opts->iocharset != fat_default_iocharset) { |
| 709 | /* Note: opts->iocharset can be NULL here */ |
| 710 | kfree(opts->iocharset); |
| 711 | opts->iocharset = fat_default_iocharset; |
| 712 | } |
| 713 | } |
| 714 | |
| 715 | static void delayed_free(struct rcu_head *p) |
| 716 | { |
| 717 | struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); |
| 718 | unload_nls(sbi->nls_disk); |
| 719 | unload_nls(sbi->nls_io); |
| 720 | fat_reset_iocharset(&sbi->options); |
| 721 | kfree(sbi); |
| 722 | } |
| 723 | |
| 724 | static void fat_put_super(struct super_block *sb) |
| 725 | { |
| 726 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 727 | |
| 728 | fat_set_state(sb, 0, 0); |
| 729 | |
| 730 | iput(sbi->fsinfo_inode); |
| 731 | iput(sbi->fat_inode); |
| 732 | |
| 733 | call_rcu(&sbi->rcu, delayed_free); |
| 734 | } |
| 735 | |
| 736 | static struct kmem_cache *fat_inode_cachep; |
| 737 | |
| 738 | static struct inode *fat_alloc_inode(struct super_block *sb) |
| 739 | { |
| 740 | struct msdos_inode_info *ei; |
| 741 | ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); |
| 742 | if (!ei) |
| 743 | return NULL; |
| 744 | |
| 745 | init_rwsem(&ei->truncate_lock); |
| 746 | return &ei->vfs_inode; |
| 747 | } |
| 748 | |
| 749 | static void fat_i_callback(struct rcu_head *head) |
| 750 | { |
| 751 | struct inode *inode = container_of(head, struct inode, i_rcu); |
| 752 | kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); |
| 753 | } |
| 754 | |
| 755 | static void fat_destroy_inode(struct inode *inode) |
| 756 | { |
| 757 | call_rcu(&inode->i_rcu, fat_i_callback); |
| 758 | } |
| 759 | |
| 760 | static void init_once(void *foo) |
| 761 | { |
| 762 | struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; |
| 763 | |
| 764 | spin_lock_init(&ei->cache_lru_lock); |
| 765 | ei->nr_caches = 0; |
| 766 | ei->cache_valid_id = FAT_CACHE_VALID + 1; |
| 767 | INIT_LIST_HEAD(&ei->cache_lru); |
| 768 | INIT_HLIST_NODE(&ei->i_fat_hash); |
| 769 | INIT_HLIST_NODE(&ei->i_dir_hash); |
| 770 | inode_init_once(&ei->vfs_inode); |
| 771 | } |
| 772 | |
| 773 | static int __init fat_init_inodecache(void) |
| 774 | { |
| 775 | fat_inode_cachep = kmem_cache_create("fat_inode_cache", |
| 776 | sizeof(struct msdos_inode_info), |
| 777 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 778 | SLAB_MEM_SPREAD|SLAB_ACCOUNT), |
| 779 | init_once); |
| 780 | if (fat_inode_cachep == NULL) |
| 781 | return -ENOMEM; |
| 782 | return 0; |
| 783 | } |
| 784 | |
| 785 | static void __exit fat_destroy_inodecache(void) |
| 786 | { |
| 787 | /* |
| 788 | * Make sure all delayed rcu free inodes are flushed before we |
| 789 | * destroy cache. |
| 790 | */ |
| 791 | rcu_barrier(); |
| 792 | kmem_cache_destroy(fat_inode_cachep); |
| 793 | } |
| 794 | |
| 795 | static int fat_remount(struct super_block *sb, int *flags, char *data) |
| 796 | { |
| 797 | bool new_rdonly; |
| 798 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 799 | *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); |
| 800 | |
| 801 | sync_filesystem(sb); |
| 802 | |
| 803 | /* make sure we update state on remount. */ |
| 804 | new_rdonly = *flags & SB_RDONLY; |
| 805 | if (new_rdonly != sb_rdonly(sb)) { |
| 806 | if (new_rdonly) |
| 807 | fat_set_state(sb, 0, 0); |
| 808 | else |
| 809 | fat_set_state(sb, 1, 1); |
| 810 | } |
| 811 | return 0; |
| 812 | } |
| 813 | |
| 814 | static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 815 | { |
| 816 | struct super_block *sb = dentry->d_sb; |
| 817 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 818 | u64 id = huge_encode_dev(sb->s_bdev->bd_dev); |
| 819 | |
| 820 | /* If the count of free cluster is still unknown, counts it here. */ |
| 821 | if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { |
| 822 | int err = fat_count_free_clusters(dentry->d_sb); |
| 823 | if (err) |
| 824 | return err; |
| 825 | } |
| 826 | |
| 827 | buf->f_type = dentry->d_sb->s_magic; |
| 828 | buf->f_bsize = sbi->cluster_size; |
| 829 | buf->f_blocks = sbi->max_cluster - FAT_START_ENT; |
| 830 | buf->f_bfree = sbi->free_clusters; |
| 831 | buf->f_bavail = sbi->free_clusters; |
| 832 | buf->f_fsid.val[0] = (u32)id; |
| 833 | buf->f_fsid.val[1] = (u32)(id >> 32); |
| 834 | buf->f_namelen = |
| 835 | (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; |
| 836 | |
| 837 | return 0; |
| 838 | } |
| 839 | |
| 840 | static int __fat_write_inode(struct inode *inode, int wait) |
| 841 | { |
| 842 | struct super_block *sb = inode->i_sb; |
| 843 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 844 | struct buffer_head *bh; |
| 845 | struct msdos_dir_entry *raw_entry; |
| 846 | loff_t i_pos; |
| 847 | sector_t blocknr; |
| 848 | int err, offset; |
| 849 | |
| 850 | if (inode->i_ino == MSDOS_ROOT_INO) |
| 851 | return 0; |
| 852 | |
| 853 | retry: |
| 854 | i_pos = fat_i_pos_read(sbi, inode); |
| 855 | if (!i_pos) |
| 856 | return 0; |
| 857 | |
| 858 | fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); |
| 859 | bh = sb_bread(sb, blocknr); |
| 860 | if (!bh) { |
| 861 | fat_msg(sb, KERN_ERR, "unable to read inode block " |
| 862 | "for updating (i_pos %lld)", i_pos); |
| 863 | return -EIO; |
| 864 | } |
| 865 | spin_lock(&sbi->inode_hash_lock); |
| 866 | if (i_pos != MSDOS_I(inode)->i_pos) { |
| 867 | spin_unlock(&sbi->inode_hash_lock); |
| 868 | brelse(bh); |
| 869 | goto retry; |
| 870 | } |
| 871 | |
| 872 | raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; |
| 873 | if (S_ISDIR(inode->i_mode)) |
| 874 | raw_entry->size = 0; |
| 875 | else |
| 876 | raw_entry->size = cpu_to_le32(inode->i_size); |
| 877 | raw_entry->attr = fat_make_attrs(inode); |
| 878 | fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); |
| 879 | fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, |
| 880 | &raw_entry->date, NULL); |
| 881 | if (sbi->options.isvfat) { |
| 882 | __le16 atime; |
| 883 | fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, |
| 884 | &raw_entry->cdate, &raw_entry->ctime_cs); |
| 885 | fat_time_unix2fat(sbi, &inode->i_atime, &atime, |
| 886 | &raw_entry->adate, NULL); |
| 887 | } |
| 888 | spin_unlock(&sbi->inode_hash_lock); |
| 889 | mark_buffer_dirty(bh); |
| 890 | err = 0; |
| 891 | if (wait) |
| 892 | err = sync_dirty_buffer(bh); |
| 893 | brelse(bh); |
| 894 | return err; |
| 895 | } |
| 896 | |
| 897 | static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) |
| 898 | { |
| 899 | int err; |
| 900 | |
| 901 | if (inode->i_ino == MSDOS_FSINFO_INO) { |
| 902 | struct super_block *sb = inode->i_sb; |
| 903 | |
| 904 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
| 905 | err = fat_clusters_flush(sb); |
| 906 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
| 907 | } else |
| 908 | err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); |
| 909 | |
| 910 | return err; |
| 911 | } |
| 912 | |
| 913 | int fat_sync_inode(struct inode *inode) |
| 914 | { |
| 915 | return __fat_write_inode(inode, 1); |
| 916 | } |
| 917 | |
| 918 | EXPORT_SYMBOL_GPL(fat_sync_inode); |
| 919 | |
| 920 | static int fat_show_options(struct seq_file *m, struct dentry *root); |
| 921 | static const struct super_operations fat_sops = { |
| 922 | .alloc_inode = fat_alloc_inode, |
| 923 | .destroy_inode = fat_destroy_inode, |
| 924 | .write_inode = fat_write_inode, |
| 925 | .evict_inode = fat_evict_inode, |
| 926 | .put_super = fat_put_super, |
| 927 | .statfs = fat_statfs, |
| 928 | .remount_fs = fat_remount, |
| 929 | |
| 930 | .show_options = fat_show_options, |
| 931 | }; |
| 932 | |
| 933 | static int fat_show_options(struct seq_file *m, struct dentry *root) |
| 934 | { |
| 935 | struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); |
| 936 | struct fat_mount_options *opts = &sbi->options; |
| 937 | int isvfat = opts->isvfat; |
| 938 | |
| 939 | if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) |
| 940 | seq_printf(m, ",uid=%u", |
| 941 | from_kuid_munged(&init_user_ns, opts->fs_uid)); |
| 942 | if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) |
| 943 | seq_printf(m, ",gid=%u", |
| 944 | from_kgid_munged(&init_user_ns, opts->fs_gid)); |
| 945 | seq_printf(m, ",fmask=%04o", opts->fs_fmask); |
| 946 | seq_printf(m, ",dmask=%04o", opts->fs_dmask); |
| 947 | if (opts->allow_utime) |
| 948 | seq_printf(m, ",allow_utime=%04o", opts->allow_utime); |
| 949 | if (sbi->nls_disk) |
| 950 | /* strip "cp" prefix from displayed option */ |
| 951 | seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); |
| 952 | if (isvfat) { |
| 953 | if (sbi->nls_io) |
| 954 | seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); |
| 955 | |
| 956 | switch (opts->shortname) { |
| 957 | case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: |
| 958 | seq_puts(m, ",shortname=win95"); |
| 959 | break; |
| 960 | case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: |
| 961 | seq_puts(m, ",shortname=winnt"); |
| 962 | break; |
| 963 | case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: |
| 964 | seq_puts(m, ",shortname=mixed"); |
| 965 | break; |
| 966 | case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: |
| 967 | seq_puts(m, ",shortname=lower"); |
| 968 | break; |
| 969 | default: |
| 970 | seq_puts(m, ",shortname=unknown"); |
| 971 | break; |
| 972 | } |
| 973 | } |
| 974 | if (opts->name_check != 'n') |
| 975 | seq_printf(m, ",check=%c", opts->name_check); |
| 976 | if (opts->usefree) |
| 977 | seq_puts(m, ",usefree"); |
| 978 | if (opts->quiet) |
| 979 | seq_puts(m, ",quiet"); |
| 980 | if (opts->showexec) |
| 981 | seq_puts(m, ",showexec"); |
| 982 | if (opts->sys_immutable) |
| 983 | seq_puts(m, ",sys_immutable"); |
| 984 | if (!isvfat) { |
| 985 | if (opts->dotsOK) |
| 986 | seq_puts(m, ",dotsOK=yes"); |
| 987 | if (opts->nocase) |
| 988 | seq_puts(m, ",nocase"); |
| 989 | } else { |
| 990 | if (opts->utf8) |
| 991 | seq_puts(m, ",utf8"); |
| 992 | if (opts->unicode_xlate) |
| 993 | seq_puts(m, ",uni_xlate"); |
| 994 | if (!opts->numtail) |
| 995 | seq_puts(m, ",nonumtail"); |
| 996 | if (opts->rodir) |
| 997 | seq_puts(m, ",rodir"); |
| 998 | } |
| 999 | if (opts->flush) |
| 1000 | seq_puts(m, ",flush"); |
| 1001 | if (opts->tz_set) { |
| 1002 | if (opts->time_offset) |
| 1003 | seq_printf(m, ",time_offset=%d", opts->time_offset); |
| 1004 | else |
| 1005 | seq_puts(m, ",tz=UTC"); |
| 1006 | } |
| 1007 | if (opts->errors == FAT_ERRORS_CONT) |
| 1008 | seq_puts(m, ",errors=continue"); |
| 1009 | else if (opts->errors == FAT_ERRORS_PANIC) |
| 1010 | seq_puts(m, ",errors=panic"); |
| 1011 | else |
| 1012 | seq_puts(m, ",errors=remount-ro"); |
| 1013 | if (opts->nfs == FAT_NFS_NOSTALE_RO) |
| 1014 | seq_puts(m, ",nfs=nostale_ro"); |
| 1015 | else if (opts->nfs) |
| 1016 | seq_puts(m, ",nfs=stale_rw"); |
| 1017 | if (opts->discard) |
| 1018 | seq_puts(m, ",discard"); |
| 1019 | if (opts->dos1xfloppy) |
| 1020 | seq_puts(m, ",dos1xfloppy"); |
| 1021 | |
| 1022 | return 0; |
| 1023 | } |
| 1024 | |
| 1025 | enum { |
| 1026 | Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, |
| 1027 | Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, |
| 1028 | Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, |
| 1029 | Opt_immutable, Opt_dots, Opt_nodots, |
| 1030 | Opt_charset, Opt_shortname_lower, Opt_shortname_win95, |
| 1031 | Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, |
| 1032 | Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, |
| 1033 | Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, |
| 1034 | Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, |
| 1035 | Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, |
| 1036 | }; |
| 1037 | |
| 1038 | static const match_table_t fat_tokens = { |
| 1039 | {Opt_check_r, "check=relaxed"}, |
| 1040 | {Opt_check_s, "check=strict"}, |
| 1041 | {Opt_check_n, "check=normal"}, |
| 1042 | {Opt_check_r, "check=r"}, |
| 1043 | {Opt_check_s, "check=s"}, |
| 1044 | {Opt_check_n, "check=n"}, |
| 1045 | {Opt_uid, "uid=%u"}, |
| 1046 | {Opt_gid, "gid=%u"}, |
| 1047 | {Opt_umask, "umask=%o"}, |
| 1048 | {Opt_dmask, "dmask=%o"}, |
| 1049 | {Opt_fmask, "fmask=%o"}, |
| 1050 | {Opt_allow_utime, "allow_utime=%o"}, |
| 1051 | {Opt_codepage, "codepage=%u"}, |
| 1052 | {Opt_usefree, "usefree"}, |
| 1053 | {Opt_nocase, "nocase"}, |
| 1054 | {Opt_quiet, "quiet"}, |
| 1055 | {Opt_showexec, "showexec"}, |
| 1056 | {Opt_debug, "debug"}, |
| 1057 | {Opt_immutable, "sys_immutable"}, |
| 1058 | {Opt_flush, "flush"}, |
| 1059 | {Opt_tz_utc, "tz=UTC"}, |
| 1060 | {Opt_time_offset, "time_offset=%d"}, |
| 1061 | {Opt_err_cont, "errors=continue"}, |
| 1062 | {Opt_err_panic, "errors=panic"}, |
| 1063 | {Opt_err_ro, "errors=remount-ro"}, |
| 1064 | {Opt_discard, "discard"}, |
| 1065 | {Opt_nfs_stale_rw, "nfs"}, |
| 1066 | {Opt_nfs_stale_rw, "nfs=stale_rw"}, |
| 1067 | {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, |
| 1068 | {Opt_dos1xfloppy, "dos1xfloppy"}, |
| 1069 | {Opt_obsolete, "conv=binary"}, |
| 1070 | {Opt_obsolete, "conv=text"}, |
| 1071 | {Opt_obsolete, "conv=auto"}, |
| 1072 | {Opt_obsolete, "conv=b"}, |
| 1073 | {Opt_obsolete, "conv=t"}, |
| 1074 | {Opt_obsolete, "conv=a"}, |
| 1075 | {Opt_obsolete, "fat=%u"}, |
| 1076 | {Opt_obsolete, "blocksize=%u"}, |
| 1077 | {Opt_obsolete, "cvf_format=%20s"}, |
| 1078 | {Opt_obsolete, "cvf_options=%100s"}, |
| 1079 | {Opt_obsolete, "posix"}, |
| 1080 | {Opt_err, NULL}, |
| 1081 | }; |
| 1082 | static const match_table_t msdos_tokens = { |
| 1083 | {Opt_nodots, "nodots"}, |
| 1084 | {Opt_nodots, "dotsOK=no"}, |
| 1085 | {Opt_dots, "dots"}, |
| 1086 | {Opt_dots, "dotsOK=yes"}, |
| 1087 | {Opt_err, NULL} |
| 1088 | }; |
| 1089 | static const match_table_t vfat_tokens = { |
| 1090 | {Opt_charset, "iocharset=%s"}, |
| 1091 | {Opt_shortname_lower, "shortname=lower"}, |
| 1092 | {Opt_shortname_win95, "shortname=win95"}, |
| 1093 | {Opt_shortname_winnt, "shortname=winnt"}, |
| 1094 | {Opt_shortname_mixed, "shortname=mixed"}, |
| 1095 | {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ |
| 1096 | {Opt_utf8_no, "utf8=no"}, |
| 1097 | {Opt_utf8_no, "utf8=false"}, |
| 1098 | {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ |
| 1099 | {Opt_utf8_yes, "utf8=yes"}, |
| 1100 | {Opt_utf8_yes, "utf8=true"}, |
| 1101 | {Opt_utf8_yes, "utf8"}, |
| 1102 | {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ |
| 1103 | {Opt_uni_xl_no, "uni_xlate=no"}, |
| 1104 | {Opt_uni_xl_no, "uni_xlate=false"}, |
| 1105 | {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ |
| 1106 | {Opt_uni_xl_yes, "uni_xlate=yes"}, |
| 1107 | {Opt_uni_xl_yes, "uni_xlate=true"}, |
| 1108 | {Opt_uni_xl_yes, "uni_xlate"}, |
| 1109 | {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ |
| 1110 | {Opt_nonumtail_no, "nonumtail=no"}, |
| 1111 | {Opt_nonumtail_no, "nonumtail=false"}, |
| 1112 | {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ |
| 1113 | {Opt_nonumtail_yes, "nonumtail=yes"}, |
| 1114 | {Opt_nonumtail_yes, "nonumtail=true"}, |
| 1115 | {Opt_nonumtail_yes, "nonumtail"}, |
| 1116 | {Opt_rodir, "rodir"}, |
| 1117 | {Opt_err, NULL} |
| 1118 | }; |
| 1119 | |
| 1120 | static int parse_options(struct super_block *sb, char *options, int is_vfat, |
| 1121 | int silent, int *debug, struct fat_mount_options *opts) |
| 1122 | { |
| 1123 | char *p; |
| 1124 | substring_t args[MAX_OPT_ARGS]; |
| 1125 | int option; |
| 1126 | char *iocharset; |
| 1127 | |
| 1128 | opts->isvfat = is_vfat; |
| 1129 | |
| 1130 | opts->fs_uid = current_uid(); |
| 1131 | opts->fs_gid = current_gid(); |
| 1132 | opts->fs_fmask = opts->fs_dmask = current_umask(); |
| 1133 | opts->allow_utime = -1; |
| 1134 | opts->codepage = fat_default_codepage; |
| 1135 | fat_reset_iocharset(opts); |
| 1136 | if (is_vfat) { |
| 1137 | opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; |
| 1138 | opts->rodir = 0; |
| 1139 | } else { |
| 1140 | opts->shortname = 0; |
| 1141 | opts->rodir = 1; |
| 1142 | } |
| 1143 | opts->name_check = 'n'; |
| 1144 | opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; |
| 1145 | opts->unicode_xlate = 0; |
| 1146 | opts->numtail = 1; |
| 1147 | opts->usefree = opts->nocase = 0; |
| 1148 | opts->tz_set = 0; |
| 1149 | opts->nfs = 0; |
| 1150 | opts->errors = FAT_ERRORS_RO; |
| 1151 | *debug = 0; |
| 1152 | |
| 1153 | opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; |
| 1154 | |
| 1155 | if (!options) |
| 1156 | goto out; |
| 1157 | |
| 1158 | while ((p = strsep(&options, ",")) != NULL) { |
| 1159 | int token; |
| 1160 | if (!*p) |
| 1161 | continue; |
| 1162 | |
| 1163 | token = match_token(p, fat_tokens, args); |
| 1164 | if (token == Opt_err) { |
| 1165 | if (is_vfat) |
| 1166 | token = match_token(p, vfat_tokens, args); |
| 1167 | else |
| 1168 | token = match_token(p, msdos_tokens, args); |
| 1169 | } |
| 1170 | switch (token) { |
| 1171 | case Opt_check_s: |
| 1172 | opts->name_check = 's'; |
| 1173 | break; |
| 1174 | case Opt_check_r: |
| 1175 | opts->name_check = 'r'; |
| 1176 | break; |
| 1177 | case Opt_check_n: |
| 1178 | opts->name_check = 'n'; |
| 1179 | break; |
| 1180 | case Opt_usefree: |
| 1181 | opts->usefree = 1; |
| 1182 | break; |
| 1183 | case Opt_nocase: |
| 1184 | if (!is_vfat) |
| 1185 | opts->nocase = 1; |
| 1186 | else { |
| 1187 | /* for backward compatibility */ |
| 1188 | opts->shortname = VFAT_SFN_DISPLAY_WIN95 |
| 1189 | | VFAT_SFN_CREATE_WIN95; |
| 1190 | } |
| 1191 | break; |
| 1192 | case Opt_quiet: |
| 1193 | opts->quiet = 1; |
| 1194 | break; |
| 1195 | case Opt_showexec: |
| 1196 | opts->showexec = 1; |
| 1197 | break; |
| 1198 | case Opt_debug: |
| 1199 | *debug = 1; |
| 1200 | break; |
| 1201 | case Opt_immutable: |
| 1202 | opts->sys_immutable = 1; |
| 1203 | break; |
| 1204 | case Opt_uid: |
| 1205 | if (match_int(&args[0], &option)) |
| 1206 | return -EINVAL; |
| 1207 | opts->fs_uid = make_kuid(current_user_ns(), option); |
| 1208 | if (!uid_valid(opts->fs_uid)) |
| 1209 | return -EINVAL; |
| 1210 | break; |
| 1211 | case Opt_gid: |
| 1212 | if (match_int(&args[0], &option)) |
| 1213 | return -EINVAL; |
| 1214 | opts->fs_gid = make_kgid(current_user_ns(), option); |
| 1215 | if (!gid_valid(opts->fs_gid)) |
| 1216 | return -EINVAL; |
| 1217 | break; |
| 1218 | case Opt_umask: |
| 1219 | if (match_octal(&args[0], &option)) |
| 1220 | return -EINVAL; |
| 1221 | opts->fs_fmask = opts->fs_dmask = option; |
| 1222 | break; |
| 1223 | case Opt_dmask: |
| 1224 | if (match_octal(&args[0], &option)) |
| 1225 | return -EINVAL; |
| 1226 | opts->fs_dmask = option; |
| 1227 | break; |
| 1228 | case Opt_fmask: |
| 1229 | if (match_octal(&args[0], &option)) |
| 1230 | return -EINVAL; |
| 1231 | opts->fs_fmask = option; |
| 1232 | break; |
| 1233 | case Opt_allow_utime: |
| 1234 | if (match_octal(&args[0], &option)) |
| 1235 | return -EINVAL; |
| 1236 | opts->allow_utime = option & (S_IWGRP | S_IWOTH); |
| 1237 | break; |
| 1238 | case Opt_codepage: |
| 1239 | if (match_int(&args[0], &option)) |
| 1240 | return -EINVAL; |
| 1241 | opts->codepage = option; |
| 1242 | break; |
| 1243 | case Opt_flush: |
| 1244 | opts->flush = 1; |
| 1245 | break; |
| 1246 | case Opt_time_offset: |
| 1247 | if (match_int(&args[0], &option)) |
| 1248 | return -EINVAL; |
| 1249 | /* |
| 1250 | * GMT+-12 zones may have DST corrections so at least |
| 1251 | * 13 hours difference is needed. Make the limit 24 |
| 1252 | * just in case someone invents something unusual. |
| 1253 | */ |
| 1254 | if (option < -24 * 60 || option > 24 * 60) |
| 1255 | return -EINVAL; |
| 1256 | opts->tz_set = 1; |
| 1257 | opts->time_offset = option; |
| 1258 | break; |
| 1259 | case Opt_tz_utc: |
| 1260 | opts->tz_set = 1; |
| 1261 | opts->time_offset = 0; |
| 1262 | break; |
| 1263 | case Opt_err_cont: |
| 1264 | opts->errors = FAT_ERRORS_CONT; |
| 1265 | break; |
| 1266 | case Opt_err_panic: |
| 1267 | opts->errors = FAT_ERRORS_PANIC; |
| 1268 | break; |
| 1269 | case Opt_err_ro: |
| 1270 | opts->errors = FAT_ERRORS_RO; |
| 1271 | break; |
| 1272 | case Opt_nfs_stale_rw: |
| 1273 | opts->nfs = FAT_NFS_STALE_RW; |
| 1274 | break; |
| 1275 | case Opt_nfs_nostale_ro: |
| 1276 | opts->nfs = FAT_NFS_NOSTALE_RO; |
| 1277 | break; |
| 1278 | case Opt_dos1xfloppy: |
| 1279 | opts->dos1xfloppy = 1; |
| 1280 | break; |
| 1281 | |
| 1282 | /* msdos specific */ |
| 1283 | case Opt_dots: |
| 1284 | opts->dotsOK = 1; |
| 1285 | break; |
| 1286 | case Opt_nodots: |
| 1287 | opts->dotsOK = 0; |
| 1288 | break; |
| 1289 | |
| 1290 | /* vfat specific */ |
| 1291 | case Opt_charset: |
| 1292 | fat_reset_iocharset(opts); |
| 1293 | iocharset = match_strdup(&args[0]); |
| 1294 | if (!iocharset) |
| 1295 | return -ENOMEM; |
| 1296 | opts->iocharset = iocharset; |
| 1297 | break; |
| 1298 | case Opt_shortname_lower: |
| 1299 | opts->shortname = VFAT_SFN_DISPLAY_LOWER |
| 1300 | | VFAT_SFN_CREATE_WIN95; |
| 1301 | break; |
| 1302 | case Opt_shortname_win95: |
| 1303 | opts->shortname = VFAT_SFN_DISPLAY_WIN95 |
| 1304 | | VFAT_SFN_CREATE_WIN95; |
| 1305 | break; |
| 1306 | case Opt_shortname_winnt: |
| 1307 | opts->shortname = VFAT_SFN_DISPLAY_WINNT |
| 1308 | | VFAT_SFN_CREATE_WINNT; |
| 1309 | break; |
| 1310 | case Opt_shortname_mixed: |
| 1311 | opts->shortname = VFAT_SFN_DISPLAY_WINNT |
| 1312 | | VFAT_SFN_CREATE_WIN95; |
| 1313 | break; |
| 1314 | case Opt_utf8_no: /* 0 or no or false */ |
| 1315 | opts->utf8 = 0; |
| 1316 | break; |
| 1317 | case Opt_utf8_yes: /* empty or 1 or yes or true */ |
| 1318 | opts->utf8 = 1; |
| 1319 | break; |
| 1320 | case Opt_uni_xl_no: /* 0 or no or false */ |
| 1321 | opts->unicode_xlate = 0; |
| 1322 | break; |
| 1323 | case Opt_uni_xl_yes: /* empty or 1 or yes or true */ |
| 1324 | opts->unicode_xlate = 1; |
| 1325 | break; |
| 1326 | case Opt_nonumtail_no: /* 0 or no or false */ |
| 1327 | opts->numtail = 1; /* negated option */ |
| 1328 | break; |
| 1329 | case Opt_nonumtail_yes: /* empty or 1 or yes or true */ |
| 1330 | opts->numtail = 0; /* negated option */ |
| 1331 | break; |
| 1332 | case Opt_rodir: |
| 1333 | opts->rodir = 1; |
| 1334 | break; |
| 1335 | case Opt_discard: |
| 1336 | opts->discard = 1; |
| 1337 | break; |
| 1338 | |
| 1339 | /* obsolete mount options */ |
| 1340 | case Opt_obsolete: |
| 1341 | fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " |
| 1342 | "not supported now", p); |
| 1343 | break; |
| 1344 | /* unknown option */ |
| 1345 | default: |
| 1346 | if (!silent) { |
| 1347 | fat_msg(sb, KERN_ERR, |
| 1348 | "Unrecognized mount option \"%s\" " |
| 1349 | "or missing value", p); |
| 1350 | } |
| 1351 | return -EINVAL; |
| 1352 | } |
| 1353 | } |
| 1354 | |
| 1355 | out: |
| 1356 | /* UTF-8 doesn't provide FAT semantics */ |
| 1357 | if (!strcmp(opts->iocharset, "utf8")) { |
| 1358 | fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" |
| 1359 | " for FAT filesystems, filesystem will be " |
| 1360 | "case sensitive!"); |
| 1361 | } |
| 1362 | |
| 1363 | /* If user doesn't specify allow_utime, it's initialized from dmask. */ |
| 1364 | if (opts->allow_utime == (unsigned short)-1) |
| 1365 | opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); |
| 1366 | if (opts->unicode_xlate) |
| 1367 | opts->utf8 = 0; |
| 1368 | if (opts->nfs == FAT_NFS_NOSTALE_RO) { |
| 1369 | sb->s_flags |= SB_RDONLY; |
| 1370 | sb->s_export_op = &fat_export_ops_nostale; |
| 1371 | } |
| 1372 | |
| 1373 | return 0; |
| 1374 | } |
| 1375 | |
| 1376 | static void fat_dummy_inode_init(struct inode *inode) |
| 1377 | { |
| 1378 | /* Initialize this dummy inode to work as no-op. */ |
| 1379 | MSDOS_I(inode)->mmu_private = 0; |
| 1380 | MSDOS_I(inode)->i_start = 0; |
| 1381 | MSDOS_I(inode)->i_logstart = 0; |
| 1382 | MSDOS_I(inode)->i_attrs = 0; |
| 1383 | MSDOS_I(inode)->i_pos = 0; |
| 1384 | } |
| 1385 | |
| 1386 | static int fat_read_root(struct inode *inode) |
| 1387 | { |
| 1388 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| 1389 | int error; |
| 1390 | |
| 1391 | MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; |
| 1392 | inode->i_uid = sbi->options.fs_uid; |
| 1393 | inode->i_gid = sbi->options.fs_gid; |
| 1394 | inode_inc_iversion(inode); |
| 1395 | inode->i_generation = 0; |
| 1396 | inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); |
| 1397 | inode->i_op = sbi->dir_ops; |
| 1398 | inode->i_fop = &fat_dir_operations; |
| 1399 | if (sbi->fat_bits == 32) { |
| 1400 | MSDOS_I(inode)->i_start = sbi->root_cluster; |
| 1401 | error = fat_calc_dir_size(inode); |
| 1402 | if (error < 0) |
| 1403 | return error; |
| 1404 | } else { |
| 1405 | MSDOS_I(inode)->i_start = 0; |
| 1406 | inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); |
| 1407 | } |
| 1408 | inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) |
| 1409 | & ~((loff_t)sbi->cluster_size - 1)) >> 9; |
| 1410 | MSDOS_I(inode)->i_logstart = 0; |
| 1411 | MSDOS_I(inode)->mmu_private = inode->i_size; |
| 1412 | |
| 1413 | fat_save_attrs(inode, ATTR_DIR); |
| 1414 | inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; |
| 1415 | inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; |
| 1416 | set_nlink(inode, fat_subdirs(inode)+2); |
| 1417 | |
| 1418 | return 0; |
| 1419 | } |
| 1420 | |
| 1421 | static unsigned long calc_fat_clusters(struct super_block *sb) |
| 1422 | { |
| 1423 | struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| 1424 | |
| 1425 | /* Divide first to avoid overflow */ |
| 1426 | if (sbi->fat_bits != 12) { |
| 1427 | unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; |
| 1428 | return ent_per_sec * sbi->fat_length; |
| 1429 | } |
| 1430 | |
| 1431 | return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; |
| 1432 | } |
| 1433 | |
| 1434 | static bool fat_bpb_is_zero(struct fat_boot_sector *b) |
| 1435 | { |
| 1436 | if (get_unaligned_le16(&b->sector_size)) |
| 1437 | return false; |
| 1438 | if (b->sec_per_clus) |
| 1439 | return false; |
| 1440 | if (b->reserved) |
| 1441 | return false; |
| 1442 | if (b->fats) |
| 1443 | return false; |
| 1444 | if (get_unaligned_le16(&b->dir_entries)) |
| 1445 | return false; |
| 1446 | if (get_unaligned_le16(&b->sectors)) |
| 1447 | return false; |
| 1448 | if (b->media) |
| 1449 | return false; |
| 1450 | if (b->fat_length) |
| 1451 | return false; |
| 1452 | if (b->secs_track) |
| 1453 | return false; |
| 1454 | if (b->heads) |
| 1455 | return false; |
| 1456 | return true; |
| 1457 | } |
| 1458 | |
| 1459 | static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, |
| 1460 | int silent, struct fat_bios_param_block *bpb) |
| 1461 | { |
| 1462 | int error = -EINVAL; |
| 1463 | |
| 1464 | /* Read in BPB ... */ |
| 1465 | memset(bpb, 0, sizeof(*bpb)); |
| 1466 | bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); |
| 1467 | bpb->fat_sec_per_clus = b->sec_per_clus; |
| 1468 | bpb->fat_reserved = le16_to_cpu(b->reserved); |
| 1469 | bpb->fat_fats = b->fats; |
| 1470 | bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); |
| 1471 | bpb->fat_sectors = get_unaligned_le16(&b->sectors); |
| 1472 | bpb->fat_fat_length = le16_to_cpu(b->fat_length); |
| 1473 | bpb->fat_total_sect = le32_to_cpu(b->total_sect); |
| 1474 | |
| 1475 | bpb->fat16_state = b->fat16.state; |
| 1476 | bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); |
| 1477 | |
| 1478 | bpb->fat32_length = le32_to_cpu(b->fat32.length); |
| 1479 | bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); |
| 1480 | bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); |
| 1481 | bpb->fat32_state = b->fat32.state; |
| 1482 | bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); |
| 1483 | |
| 1484 | /* Validate this looks like a FAT filesystem BPB */ |
| 1485 | if (!bpb->fat_reserved) { |
| 1486 | if (!silent) |
| 1487 | fat_msg(sb, KERN_ERR, |
| 1488 | "bogus number of reserved sectors"); |
| 1489 | goto out; |
| 1490 | } |
| 1491 | if (!bpb->fat_fats) { |
| 1492 | if (!silent) |
| 1493 | fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); |
| 1494 | goto out; |
| 1495 | } |
| 1496 | |
| 1497 | /* |
| 1498 | * Earlier we checked here that b->secs_track and b->head are nonzero, |
| 1499 | * but it turns out valid FAT filesystems can have zero there. |
| 1500 | */ |
| 1501 | |
| 1502 | if (!fat_valid_media(b->media)) { |
| 1503 | if (!silent) |
| 1504 | fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", |
| 1505 | (unsigned)b->media); |
| 1506 | goto out; |
| 1507 | } |
| 1508 | |
| 1509 | if (!is_power_of_2(bpb->fat_sector_size) |
| 1510 | || (bpb->fat_sector_size < 512) |
| 1511 | || (bpb->fat_sector_size > 4096)) { |
| 1512 | if (!silent) |
| 1513 | fat_msg(sb, KERN_ERR, "bogus logical sector size %u", |
| 1514 | (unsigned)bpb->fat_sector_size); |
| 1515 | goto out; |
| 1516 | } |
| 1517 | |
| 1518 | if (!is_power_of_2(bpb->fat_sec_per_clus)) { |
| 1519 | if (!silent) |
| 1520 | fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", |
| 1521 | (unsigned)bpb->fat_sec_per_clus); |
| 1522 | goto out; |
| 1523 | } |
| 1524 | |
| 1525 | error = 0; |
| 1526 | |
| 1527 | out: |
| 1528 | return error; |
| 1529 | } |
| 1530 | |
| 1531 | static int fat_read_static_bpb(struct super_block *sb, |
| 1532 | struct fat_boot_sector *b, int silent, |
| 1533 | struct fat_bios_param_block *bpb) |
| 1534 | { |
| 1535 | static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; |
| 1536 | |
| 1537 | struct fat_floppy_defaults *fdefaults = NULL; |
| 1538 | int error = -EINVAL; |
| 1539 | sector_t bd_sects; |
| 1540 | unsigned i; |
| 1541 | |
| 1542 | bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE; |
| 1543 | |
| 1544 | /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ |
| 1545 | if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { |
| 1546 | if (!silent) |
| 1547 | fat_msg(sb, KERN_ERR, |
| 1548 | "%s; no bootstrapping code", notdos1x); |
| 1549 | goto out; |
| 1550 | } |
| 1551 | |
| 1552 | /* |
| 1553 | * If any value in this region is non-zero, it isn't archaic |
| 1554 | * DOS. |
| 1555 | */ |
| 1556 | if (!fat_bpb_is_zero(b)) { |
| 1557 | if (!silent) |
| 1558 | fat_msg(sb, KERN_ERR, |
| 1559 | "%s; DOS 2.x BPB is non-zero", notdos1x); |
| 1560 | goto out; |
| 1561 | } |
| 1562 | |
| 1563 | for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { |
| 1564 | if (floppy_defaults[i].nr_sectors == bd_sects) { |
| 1565 | fdefaults = &floppy_defaults[i]; |
| 1566 | break; |
| 1567 | } |
| 1568 | } |
| 1569 | |
| 1570 | if (fdefaults == NULL) { |
| 1571 | if (!silent) |
| 1572 | fat_msg(sb, KERN_WARNING, |
| 1573 | "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", |
| 1574 | (u64)bd_sects); |
| 1575 | goto out; |
| 1576 | } |
| 1577 | |
| 1578 | if (!silent) |
| 1579 | fat_msg(sb, KERN_INFO, |
| 1580 | "This looks like a DOS 1.x volume; assuming default BPB values"); |
| 1581 | |
| 1582 | memset(bpb, 0, sizeof(*bpb)); |
| 1583 | bpb->fat_sector_size = SECTOR_SIZE; |
| 1584 | bpb->fat_sec_per_clus = fdefaults->sec_per_clus; |
| 1585 | bpb->fat_reserved = 1; |
| 1586 | bpb->fat_fats = 2; |
| 1587 | bpb->fat_dir_entries = fdefaults->dir_entries; |
| 1588 | bpb->fat_sectors = fdefaults->nr_sectors; |
| 1589 | bpb->fat_fat_length = fdefaults->fat_length; |
| 1590 | |
| 1591 | error = 0; |
| 1592 | |
| 1593 | out: |
| 1594 | return error; |
| 1595 | } |
| 1596 | |
| 1597 | /* |
| 1598 | * Read the super block of an MS-DOS FS. |
| 1599 | */ |
| 1600 | int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, |
| 1601 | void (*setup)(struct super_block *)) |
| 1602 | { |
| 1603 | struct inode *root_inode = NULL, *fat_inode = NULL; |
| 1604 | struct inode *fsinfo_inode = NULL; |
| 1605 | struct buffer_head *bh; |
| 1606 | struct fat_bios_param_block bpb; |
| 1607 | struct msdos_sb_info *sbi; |
| 1608 | u16 logical_sector_size; |
| 1609 | u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; |
| 1610 | int debug; |
| 1611 | long error; |
| 1612 | char buf[50]; |
| 1613 | |
| 1614 | /* |
| 1615 | * GFP_KERNEL is ok here, because while we do hold the |
| 1616 | * superblock lock, memory pressure can't call back into |
| 1617 | * the filesystem, since we're only just about to mount |
| 1618 | * it and have no inodes etc active! |
| 1619 | */ |
| 1620 | sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); |
| 1621 | if (!sbi) |
| 1622 | return -ENOMEM; |
| 1623 | sb->s_fs_info = sbi; |
| 1624 | |
| 1625 | sb->s_flags |= SB_NODIRATIME; |
| 1626 | sb->s_magic = MSDOS_SUPER_MAGIC; |
| 1627 | sb->s_op = &fat_sops; |
| 1628 | sb->s_export_op = &fat_export_ops; |
| 1629 | /* |
| 1630 | * fat timestamps are complex and truncated by fat itself, so |
| 1631 | * we set 1 here to be fast |
| 1632 | */ |
| 1633 | sb->s_time_gran = 1; |
| 1634 | mutex_init(&sbi->nfs_build_inode_lock); |
| 1635 | ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, |
| 1636 | DEFAULT_RATELIMIT_BURST); |
| 1637 | |
| 1638 | error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); |
| 1639 | if (error) |
| 1640 | goto out_fail; |
| 1641 | |
| 1642 | setup(sb); /* flavour-specific stuff that needs options */ |
| 1643 | |
| 1644 | error = -EIO; |
| 1645 | sb_min_blocksize(sb, 512); |
| 1646 | bh = sb_bread(sb, 0); |
| 1647 | if (bh == NULL) { |
| 1648 | fat_msg(sb, KERN_ERR, "unable to read boot sector"); |
| 1649 | goto out_fail; |
| 1650 | } |
| 1651 | |
| 1652 | error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, |
| 1653 | &bpb); |
| 1654 | if (error == -EINVAL && sbi->options.dos1xfloppy) |
| 1655 | error = fat_read_static_bpb(sb, |
| 1656 | (struct fat_boot_sector *)bh->b_data, silent, &bpb); |
| 1657 | brelse(bh); |
| 1658 | |
| 1659 | if (error == -EINVAL) |
| 1660 | goto out_invalid; |
| 1661 | else if (error) |
| 1662 | goto out_fail; |
| 1663 | |
| 1664 | logical_sector_size = bpb.fat_sector_size; |
| 1665 | sbi->sec_per_clus = bpb.fat_sec_per_clus; |
| 1666 | |
| 1667 | error = -EIO; |
| 1668 | if (logical_sector_size < sb->s_blocksize) { |
| 1669 | fat_msg(sb, KERN_ERR, "logical sector size too small for device" |
| 1670 | " (logical sector size = %u)", logical_sector_size); |
| 1671 | goto out_fail; |
| 1672 | } |
| 1673 | |
| 1674 | if (logical_sector_size > sb->s_blocksize) { |
| 1675 | struct buffer_head *bh_resize; |
| 1676 | |
| 1677 | if (!sb_set_blocksize(sb, logical_sector_size)) { |
| 1678 | fat_msg(sb, KERN_ERR, "unable to set blocksize %u", |
| 1679 | logical_sector_size); |
| 1680 | goto out_fail; |
| 1681 | } |
| 1682 | |
| 1683 | /* Verify that the larger boot sector is fully readable */ |
| 1684 | bh_resize = sb_bread(sb, 0); |
| 1685 | if (bh_resize == NULL) { |
| 1686 | fat_msg(sb, KERN_ERR, "unable to read boot sector" |
| 1687 | " (logical sector size = %lu)", |
| 1688 | sb->s_blocksize); |
| 1689 | goto out_fail; |
| 1690 | } |
| 1691 | brelse(bh_resize); |
| 1692 | } |
| 1693 | |
| 1694 | mutex_init(&sbi->s_lock); |
| 1695 | sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; |
| 1696 | sbi->cluster_bits = ffs(sbi->cluster_size) - 1; |
| 1697 | sbi->fats = bpb.fat_fats; |
| 1698 | sbi->fat_bits = 0; /* Don't know yet */ |
| 1699 | sbi->fat_start = bpb.fat_reserved; |
| 1700 | sbi->fat_length = bpb.fat_fat_length; |
| 1701 | sbi->root_cluster = 0; |
| 1702 | sbi->free_clusters = -1; /* Don't know yet */ |
| 1703 | sbi->free_clus_valid = 0; |
| 1704 | sbi->prev_free = FAT_START_ENT; |
| 1705 | sb->s_maxbytes = 0xffffffff; |
| 1706 | |
| 1707 | if (!sbi->fat_length && bpb.fat32_length) { |
| 1708 | struct fat_boot_fsinfo *fsinfo; |
| 1709 | struct buffer_head *fsinfo_bh; |
| 1710 | |
| 1711 | /* Must be FAT32 */ |
| 1712 | sbi->fat_bits = 32; |
| 1713 | sbi->fat_length = bpb.fat32_length; |
| 1714 | sbi->root_cluster = bpb.fat32_root_cluster; |
| 1715 | |
| 1716 | /* MC - if info_sector is 0, don't multiply by 0 */ |
| 1717 | sbi->fsinfo_sector = bpb.fat32_info_sector; |
| 1718 | if (sbi->fsinfo_sector == 0) |
| 1719 | sbi->fsinfo_sector = 1; |
| 1720 | |
| 1721 | fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); |
| 1722 | if (fsinfo_bh == NULL) { |
| 1723 | fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" |
| 1724 | " (sector = %lu)", sbi->fsinfo_sector); |
| 1725 | goto out_fail; |
| 1726 | } |
| 1727 | |
| 1728 | fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; |
| 1729 | if (!IS_FSINFO(fsinfo)) { |
| 1730 | fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " |
| 1731 | "0x%08x, 0x%08x (sector = %lu)", |
| 1732 | le32_to_cpu(fsinfo->signature1), |
| 1733 | le32_to_cpu(fsinfo->signature2), |
| 1734 | sbi->fsinfo_sector); |
| 1735 | } else { |
| 1736 | if (sbi->options.usefree) |
| 1737 | sbi->free_clus_valid = 1; |
| 1738 | sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); |
| 1739 | sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); |
| 1740 | } |
| 1741 | |
| 1742 | brelse(fsinfo_bh); |
| 1743 | } |
| 1744 | |
| 1745 | /* interpret volume ID as a little endian 32 bit integer */ |
| 1746 | if (sbi->fat_bits == 32) |
| 1747 | sbi->vol_id = bpb.fat32_vol_id; |
| 1748 | else /* fat 16 or 12 */ |
| 1749 | sbi->vol_id = bpb.fat16_vol_id; |
| 1750 | |
| 1751 | sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); |
| 1752 | sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; |
| 1753 | |
| 1754 | sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; |
| 1755 | sbi->dir_entries = bpb.fat_dir_entries; |
| 1756 | if (sbi->dir_entries & (sbi->dir_per_block - 1)) { |
| 1757 | if (!silent) |
| 1758 | fat_msg(sb, KERN_ERR, "bogus number of directory entries" |
| 1759 | " (%u)", sbi->dir_entries); |
| 1760 | goto out_invalid; |
| 1761 | } |
| 1762 | |
| 1763 | rootdir_sectors = sbi->dir_entries |
| 1764 | * sizeof(struct msdos_dir_entry) / sb->s_blocksize; |
| 1765 | sbi->data_start = sbi->dir_start + rootdir_sectors; |
| 1766 | total_sectors = bpb.fat_sectors; |
| 1767 | if (total_sectors == 0) |
| 1768 | total_sectors = bpb.fat_total_sect; |
| 1769 | |
| 1770 | total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; |
| 1771 | |
| 1772 | if (sbi->fat_bits != 32) |
| 1773 | sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; |
| 1774 | |
| 1775 | /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ |
| 1776 | if (sbi->fat_bits == 32) |
| 1777 | sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; |
| 1778 | else /* fat 16 or 12 */ |
| 1779 | sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; |
| 1780 | |
| 1781 | /* check that FAT table does not overflow */ |
| 1782 | fat_clusters = calc_fat_clusters(sb); |
| 1783 | total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); |
| 1784 | if (total_clusters > MAX_FAT(sb)) { |
| 1785 | if (!silent) |
| 1786 | fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", |
| 1787 | total_clusters); |
| 1788 | goto out_invalid; |
| 1789 | } |
| 1790 | |
| 1791 | sbi->max_cluster = total_clusters + FAT_START_ENT; |
| 1792 | /* check the free_clusters, it's not necessarily correct */ |
| 1793 | if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) |
| 1794 | sbi->free_clusters = -1; |
| 1795 | /* check the prev_free, it's not necessarily correct */ |
| 1796 | sbi->prev_free %= sbi->max_cluster; |
| 1797 | if (sbi->prev_free < FAT_START_ENT) |
| 1798 | sbi->prev_free = FAT_START_ENT; |
| 1799 | |
| 1800 | /* set up enough so that it can read an inode */ |
| 1801 | fat_hash_init(sb); |
| 1802 | dir_hash_init(sb); |
| 1803 | fat_ent_access_init(sb); |
| 1804 | |
| 1805 | /* |
| 1806 | * The low byte of FAT's first entry must have same value with |
| 1807 | * media-field. But in real world, too many devices is |
| 1808 | * writing wrong value. So, removed that validity check. |
| 1809 | * |
| 1810 | * if (FAT_FIRST_ENT(sb, media) != first) |
| 1811 | */ |
| 1812 | |
| 1813 | error = -EINVAL; |
| 1814 | sprintf(buf, "cp%d", sbi->options.codepage); |
| 1815 | sbi->nls_disk = load_nls(buf); |
| 1816 | if (!sbi->nls_disk) { |
| 1817 | fat_msg(sb, KERN_ERR, "codepage %s not found", buf); |
| 1818 | goto out_fail; |
| 1819 | } |
| 1820 | |
| 1821 | /* FIXME: utf8 is using iocharset for upper/lower conversion */ |
| 1822 | if (sbi->options.isvfat) { |
| 1823 | sbi->nls_io = load_nls(sbi->options.iocharset); |
| 1824 | if (!sbi->nls_io) { |
| 1825 | fat_msg(sb, KERN_ERR, "IO charset %s not found", |
| 1826 | sbi->options.iocharset); |
| 1827 | goto out_fail; |
| 1828 | } |
| 1829 | } |
| 1830 | |
| 1831 | error = -ENOMEM; |
| 1832 | fat_inode = new_inode(sb); |
| 1833 | if (!fat_inode) |
| 1834 | goto out_fail; |
| 1835 | fat_dummy_inode_init(fat_inode); |
| 1836 | sbi->fat_inode = fat_inode; |
| 1837 | |
| 1838 | fsinfo_inode = new_inode(sb); |
| 1839 | if (!fsinfo_inode) |
| 1840 | goto out_fail; |
| 1841 | fat_dummy_inode_init(fsinfo_inode); |
| 1842 | fsinfo_inode->i_ino = MSDOS_FSINFO_INO; |
| 1843 | sbi->fsinfo_inode = fsinfo_inode; |
| 1844 | insert_inode_hash(fsinfo_inode); |
| 1845 | |
| 1846 | root_inode = new_inode(sb); |
| 1847 | if (!root_inode) |
| 1848 | goto out_fail; |
| 1849 | root_inode->i_ino = MSDOS_ROOT_INO; |
| 1850 | inode_set_iversion(root_inode, 1); |
| 1851 | error = fat_read_root(root_inode); |
| 1852 | if (error < 0) { |
| 1853 | iput(root_inode); |
| 1854 | goto out_fail; |
| 1855 | } |
| 1856 | error = -ENOMEM; |
| 1857 | insert_inode_hash(root_inode); |
| 1858 | fat_attach(root_inode, 0); |
| 1859 | sb->s_root = d_make_root(root_inode); |
| 1860 | if (!sb->s_root) { |
| 1861 | fat_msg(sb, KERN_ERR, "get root inode failed"); |
| 1862 | goto out_fail; |
| 1863 | } |
| 1864 | |
| 1865 | if (sbi->options.discard) { |
| 1866 | struct request_queue *q = bdev_get_queue(sb->s_bdev); |
| 1867 | if (!blk_queue_discard(q)) |
| 1868 | fat_msg(sb, KERN_WARNING, |
| 1869 | "mounting with \"discard\" option, but " |
| 1870 | "the device does not support discard"); |
| 1871 | } |
| 1872 | |
| 1873 | fat_set_state(sb, 1, 0); |
| 1874 | return 0; |
| 1875 | |
| 1876 | out_invalid: |
| 1877 | error = -EINVAL; |
| 1878 | if (!silent) |
| 1879 | fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); |
| 1880 | |
| 1881 | out_fail: |
| 1882 | if (fsinfo_inode) |
| 1883 | iput(fsinfo_inode); |
| 1884 | if (fat_inode) |
| 1885 | iput(fat_inode); |
| 1886 | unload_nls(sbi->nls_io); |
| 1887 | unload_nls(sbi->nls_disk); |
| 1888 | fat_reset_iocharset(&sbi->options); |
| 1889 | sb->s_fs_info = NULL; |
| 1890 | kfree(sbi); |
| 1891 | return error; |
| 1892 | } |
| 1893 | |
| 1894 | EXPORT_SYMBOL_GPL(fat_fill_super); |
| 1895 | |
| 1896 | /* |
| 1897 | * helper function for fat_flush_inodes. This writes both the inode |
| 1898 | * and the file data blocks, waiting for in flight data blocks before |
| 1899 | * the start of the call. It does not wait for any io started |
| 1900 | * during the call |
| 1901 | */ |
| 1902 | static int writeback_inode(struct inode *inode) |
| 1903 | { |
| 1904 | |
| 1905 | int ret; |
| 1906 | |
| 1907 | /* if we used wait=1, sync_inode_metadata waits for the io for the |
| 1908 | * inode to finish. So wait=0 is sent down to sync_inode_metadata |
| 1909 | * and filemap_fdatawrite is used for the data blocks |
| 1910 | */ |
| 1911 | ret = sync_inode_metadata(inode, 0); |
| 1912 | if (!ret) |
| 1913 | ret = filemap_fdatawrite(inode->i_mapping); |
| 1914 | return ret; |
| 1915 | } |
| 1916 | |
| 1917 | /* |
| 1918 | * write data and metadata corresponding to i1 and i2. The io is |
| 1919 | * started but we do not wait for any of it to finish. |
| 1920 | * |
| 1921 | * filemap_flush is used for the block device, so if there is a dirty |
| 1922 | * page for a block already in flight, we will not wait and start the |
| 1923 | * io over again |
| 1924 | */ |
| 1925 | int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) |
| 1926 | { |
| 1927 | int ret = 0; |
| 1928 | if (!MSDOS_SB(sb)->options.flush) |
| 1929 | return 0; |
| 1930 | if (i1) |
| 1931 | ret = writeback_inode(i1); |
| 1932 | if (!ret && i2) |
| 1933 | ret = writeback_inode(i2); |
| 1934 | if (!ret) { |
| 1935 | struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; |
| 1936 | ret = filemap_flush(mapping); |
| 1937 | } |
| 1938 | return ret; |
| 1939 | } |
| 1940 | EXPORT_SYMBOL_GPL(fat_flush_inodes); |
| 1941 | |
| 1942 | static int __init init_fat_fs(void) |
| 1943 | { |
| 1944 | int err; |
| 1945 | |
| 1946 | err = fat_cache_init(); |
| 1947 | if (err) |
| 1948 | return err; |
| 1949 | |
| 1950 | err = fat_init_inodecache(); |
| 1951 | if (err) |
| 1952 | goto failed; |
| 1953 | |
| 1954 | return 0; |
| 1955 | |
| 1956 | failed: |
| 1957 | fat_cache_destroy(); |
| 1958 | return err; |
| 1959 | } |
| 1960 | |
| 1961 | static void __exit exit_fat_fs(void) |
| 1962 | { |
| 1963 | fat_cache_destroy(); |
| 1964 | fat_destroy_inodecache(); |
| 1965 | } |
| 1966 | |
| 1967 | module_init(init_fat_fs) |
| 1968 | module_exit(exit_fat_fs) |
| 1969 | |
| 1970 | MODULE_LICENSE("GPL"); |