inode.c 39 KB

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  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. #include <linux/module.h>
  13. #include <linux/init.h>
  14. #include <linux/time.h>
  15. #include <linux/slab.h>
  16. #include <linux/smp_lock.h>
  17. #include <linux/seq_file.h>
  18. #include <linux/msdos_fs.h>
  19. #include <linux/pagemap.h>
  20. #include <linux/mpage.h>
  21. #include <linux/buffer_head.h>
  22. #include <linux/mount.h>
  23. #include <linux/vfs.h>
  24. #include <linux/parser.h>
  25. #include <linux/uio.h>
  26. #include <linux/writeback.h>
  27. #include <asm/unaligned.h>
  28. #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
  29. /* if user don't select VFAT, this is undefined. */
  30. #define CONFIG_FAT_DEFAULT_IOCHARSET ""
  31. #endif
  32. static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
  33. static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
  34. static int fat_add_cluster(struct inode *inode)
  35. {
  36. int err, cluster;
  37. err = fat_alloc_clusters(inode, &cluster, 1);
  38. if (err)
  39. return err;
  40. /* FIXME: this cluster should be added after data of this
  41. * cluster is writed */
  42. err = fat_chain_add(inode, cluster, 1);
  43. if (err)
  44. fat_free_clusters(inode, cluster);
  45. return err;
  46. }
  47. static inline int __fat_get_block(struct inode *inode, sector_t iblock,
  48. unsigned long *max_blocks,
  49. struct buffer_head *bh_result, int create)
  50. {
  51. struct super_block *sb = inode->i_sb;
  52. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  53. unsigned long mapped_blocks;
  54. sector_t phys;
  55. int err, offset;
  56. err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
  57. if (err)
  58. return err;
  59. if (phys) {
  60. map_bh(bh_result, sb, phys);
  61. *max_blocks = min(mapped_blocks, *max_blocks);
  62. return 0;
  63. }
  64. if (!create)
  65. return 0;
  66. if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
  67. fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
  68. MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
  69. return -EIO;
  70. }
  71. offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
  72. if (!offset) {
  73. /* TODO: multiple cluster allocation would be desirable. */
  74. err = fat_add_cluster(inode);
  75. if (err)
  76. return err;
  77. }
  78. /* available blocks on this cluster */
  79. mapped_blocks = sbi->sec_per_clus - offset;
  80. *max_blocks = min(mapped_blocks, *max_blocks);
  81. MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
  82. err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
  83. if (err)
  84. return err;
  85. BUG_ON(!phys);
  86. BUG_ON(*max_blocks != mapped_blocks);
  87. set_buffer_new(bh_result);
  88. map_bh(bh_result, sb, phys);
  89. return 0;
  90. }
  91. static int fat_get_block(struct inode *inode, sector_t iblock,
  92. struct buffer_head *bh_result, int create)
  93. {
  94. struct super_block *sb = inode->i_sb;
  95. unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
  96. int err;
  97. err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
  98. if (err)
  99. return err;
  100. bh_result->b_size = max_blocks << sb->s_blocksize_bits;
  101. return 0;
  102. }
  103. static int fat_writepage(struct page *page, struct writeback_control *wbc)
  104. {
  105. return block_write_full_page(page, fat_get_block, wbc);
  106. }
  107. static int fat_writepages(struct address_space *mapping,
  108. struct writeback_control *wbc)
  109. {
  110. return mpage_writepages(mapping, wbc, fat_get_block);
  111. }
  112. static int fat_readpage(struct file *file, struct page *page)
  113. {
  114. return mpage_readpage(page, fat_get_block);
  115. }
  116. static int fat_readpages(struct file *file, struct address_space *mapping,
  117. struct list_head *pages, unsigned nr_pages)
  118. {
  119. return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
  120. }
  121. static int fat_prepare_write(struct file *file, struct page *page,
  122. unsigned from, unsigned to)
  123. {
  124. return cont_prepare_write(page, from, to, fat_get_block,
  125. &MSDOS_I(page->mapping->host)->mmu_private);
  126. }
  127. static int fat_commit_write(struct file *file, struct page *page,
  128. unsigned from, unsigned to)
  129. {
  130. struct inode *inode = page->mapping->host;
  131. int err = generic_commit_write(file, page, from, to);
  132. if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
  133. inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
  134. MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
  135. mark_inode_dirty(inode);
  136. }
  137. return err;
  138. }
  139. static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
  140. const struct iovec *iov,
  141. loff_t offset, unsigned long nr_segs)
  142. {
  143. struct file *file = iocb->ki_filp;
  144. struct inode *inode = file->f_mapping->host;
  145. if (rw == WRITE) {
  146. /*
  147. * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
  148. * so we need to update the ->mmu_private to block boundary.
  149. *
  150. * But we must fill the remaining area or hole by nul for
  151. * updating ->mmu_private.
  152. *
  153. * Return 0, and fallback to normal buffered write.
  154. */
  155. loff_t size = offset + iov_length(iov, nr_segs);
  156. if (MSDOS_I(inode)->mmu_private < size)
  157. return 0;
  158. }
  159. /*
  160. * FAT need to use the DIO_LOCKING for avoiding the race
  161. * condition of fat_get_block() and ->truncate().
  162. */
  163. return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
  164. offset, nr_segs, fat_get_block, NULL);
  165. }
  166. static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
  167. {
  168. return generic_block_bmap(mapping, block, fat_get_block);
  169. }
  170. static const struct address_space_operations fat_aops = {
  171. .readpage = fat_readpage,
  172. .readpages = fat_readpages,
  173. .writepage = fat_writepage,
  174. .writepages = fat_writepages,
  175. .sync_page = block_sync_page,
  176. .prepare_write = fat_prepare_write,
  177. .commit_write = fat_commit_write,
  178. .direct_IO = fat_direct_IO,
  179. .bmap = _fat_bmap
  180. };
  181. /*
  182. * New FAT inode stuff. We do the following:
  183. * a) i_ino is constant and has nothing with on-disk location.
  184. * b) FAT manages its own cache of directory entries.
  185. * c) *This* cache is indexed by on-disk location.
  186. * d) inode has an associated directory entry, all right, but
  187. * it may be unhashed.
  188. * e) currently entries are stored within struct inode. That should
  189. * change.
  190. * f) we deal with races in the following way:
  191. * 1. readdir() and lookup() do FAT-dir-cache lookup.
  192. * 2. rename() unhashes the F-d-c entry and rehashes it in
  193. * a new place.
  194. * 3. unlink() and rmdir() unhash F-d-c entry.
  195. * 4. fat_write_inode() checks whether the thing is unhashed.
  196. * If it is we silently return. If it isn't we do bread(),
  197. * check if the location is still valid and retry if it
  198. * isn't. Otherwise we do changes.
  199. * 5. Spinlock is used to protect hash/unhash/location check/lookup
  200. * 6. fat_clear_inode() unhashes the F-d-c entry.
  201. * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
  202. * and consider negative result as cache miss.
  203. */
  204. static void fat_hash_init(struct super_block *sb)
  205. {
  206. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  207. int i;
  208. spin_lock_init(&sbi->inode_hash_lock);
  209. for (i = 0; i < FAT_HASH_SIZE; i++)
  210. INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
  211. }
  212. static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
  213. {
  214. unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
  215. tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
  216. return tmp & FAT_HASH_MASK;
  217. }
  218. void fat_attach(struct inode *inode, loff_t i_pos)
  219. {
  220. struct super_block *sb = inode->i_sb;
  221. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  222. spin_lock(&sbi->inode_hash_lock);
  223. MSDOS_I(inode)->i_pos = i_pos;
  224. hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
  225. sbi->inode_hashtable + fat_hash(sb, i_pos));
  226. spin_unlock(&sbi->inode_hash_lock);
  227. }
  228. EXPORT_SYMBOL_GPL(fat_attach);
  229. void fat_detach(struct inode *inode)
  230. {
  231. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  232. spin_lock(&sbi->inode_hash_lock);
  233. MSDOS_I(inode)->i_pos = 0;
  234. hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
  235. spin_unlock(&sbi->inode_hash_lock);
  236. }
  237. EXPORT_SYMBOL_GPL(fat_detach);
  238. struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
  239. {
  240. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  241. struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
  242. struct hlist_node *_p;
  243. struct msdos_inode_info *i;
  244. struct inode *inode = NULL;
  245. spin_lock(&sbi->inode_hash_lock);
  246. hlist_for_each_entry(i, _p, head, i_fat_hash) {
  247. BUG_ON(i->vfs_inode.i_sb != sb);
  248. if (i->i_pos != i_pos)
  249. continue;
  250. inode = igrab(&i->vfs_inode);
  251. if (inode)
  252. break;
  253. }
  254. spin_unlock(&sbi->inode_hash_lock);
  255. return inode;
  256. }
  257. static int is_exec(unsigned char *extension)
  258. {
  259. unsigned char *exe_extensions = "EXECOMBAT", *walk;
  260. for (walk = exe_extensions; *walk; walk += 3)
  261. if (!strncmp(extension, walk, 3))
  262. return 1;
  263. return 0;
  264. }
  265. static int fat_calc_dir_size(struct inode *inode)
  266. {
  267. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  268. int ret, fclus, dclus;
  269. inode->i_size = 0;
  270. if (MSDOS_I(inode)->i_start == 0)
  271. return 0;
  272. ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
  273. if (ret < 0)
  274. return ret;
  275. inode->i_size = (fclus + 1) << sbi->cluster_bits;
  276. return 0;
  277. }
  278. /* doesn't deal with root inode */
  279. static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
  280. {
  281. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  282. int error;
  283. MSDOS_I(inode)->i_pos = 0;
  284. inode->i_uid = sbi->options.fs_uid;
  285. inode->i_gid = sbi->options.fs_gid;
  286. inode->i_version++;
  287. inode->i_generation = get_seconds();
  288. if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
  289. inode->i_generation &= ~1;
  290. inode->i_mode = MSDOS_MKMODE(de->attr,
  291. S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
  292. inode->i_op = sbi->dir_ops;
  293. inode->i_fop = &fat_dir_operations;
  294. MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
  295. if (sbi->fat_bits == 32)
  296. MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
  297. MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
  298. error = fat_calc_dir_size(inode);
  299. if (error < 0)
  300. return error;
  301. MSDOS_I(inode)->mmu_private = inode->i_size;
  302. inode->i_nlink = fat_subdirs(inode);
  303. } else { /* not a directory */
  304. inode->i_generation |= 1;
  305. inode->i_mode = MSDOS_MKMODE(de->attr,
  306. ((sbi->options.showexec &&
  307. !is_exec(de->ext))
  308. ? S_IRUGO|S_IWUGO : S_IRWXUGO)
  309. & ~sbi->options.fs_fmask) | S_IFREG;
  310. MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
  311. if (sbi->fat_bits == 32)
  312. MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
  313. MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
  314. inode->i_size = le32_to_cpu(de->size);
  315. inode->i_op = &fat_file_inode_operations;
  316. inode->i_fop = &fat_file_operations;
  317. inode->i_mapping->a_ops = &fat_aops;
  318. MSDOS_I(inode)->mmu_private = inode->i_size;
  319. }
  320. if (de->attr & ATTR_SYS) {
  321. if (sbi->options.sys_immutable)
  322. inode->i_flags |= S_IMMUTABLE;
  323. }
  324. MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
  325. inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
  326. & ~((loff_t)sbi->cluster_size - 1)) >> 9;
  327. inode->i_mtime.tv_sec =
  328. date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
  329. inode->i_mtime.tv_nsec = 0;
  330. if (sbi->options.isvfat) {
  331. int secs = de->ctime_cs / 100;
  332. int csecs = de->ctime_cs % 100;
  333. inode->i_ctime.tv_sec =
  334. date_dos2unix(le16_to_cpu(de->ctime),
  335. le16_to_cpu(de->cdate)) + secs;
  336. inode->i_ctime.tv_nsec = csecs * 10000000;
  337. inode->i_atime.tv_sec =
  338. date_dos2unix(0, le16_to_cpu(de->adate));
  339. inode->i_atime.tv_nsec = 0;
  340. } else
  341. inode->i_ctime = inode->i_atime = inode->i_mtime;
  342. return 0;
  343. }
  344. struct inode *fat_build_inode(struct super_block *sb,
  345. struct msdos_dir_entry *de, loff_t i_pos)
  346. {
  347. struct inode *inode;
  348. int err;
  349. inode = fat_iget(sb, i_pos);
  350. if (inode)
  351. goto out;
  352. inode = new_inode(sb);
  353. if (!inode) {
  354. inode = ERR_PTR(-ENOMEM);
  355. goto out;
  356. }
  357. inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
  358. inode->i_version = 1;
  359. err = fat_fill_inode(inode, de);
  360. if (err) {
  361. iput(inode);
  362. inode = ERR_PTR(err);
  363. goto out;
  364. }
  365. fat_attach(inode, i_pos);
  366. insert_inode_hash(inode);
  367. out:
  368. return inode;
  369. }
  370. EXPORT_SYMBOL_GPL(fat_build_inode);
  371. static void fat_delete_inode(struct inode *inode)
  372. {
  373. truncate_inode_pages(&inode->i_data, 0);
  374. if (!is_bad_inode(inode)) {
  375. inode->i_size = 0;
  376. fat_truncate(inode);
  377. }
  378. clear_inode(inode);
  379. }
  380. static void fat_clear_inode(struct inode *inode)
  381. {
  382. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  383. if (is_bad_inode(inode))
  384. return;
  385. lock_kernel();
  386. spin_lock(&sbi->inode_hash_lock);
  387. fat_cache_inval_inode(inode);
  388. hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
  389. spin_unlock(&sbi->inode_hash_lock);
  390. unlock_kernel();
  391. }
  392. static void fat_write_super(struct super_block *sb)
  393. {
  394. sb->s_dirt = 0;
  395. if (!(sb->s_flags & MS_RDONLY))
  396. fat_clusters_flush(sb);
  397. }
  398. static void fat_put_super(struct super_block *sb)
  399. {
  400. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  401. if (sbi->nls_disk) {
  402. unload_nls(sbi->nls_disk);
  403. sbi->nls_disk = NULL;
  404. sbi->options.codepage = fat_default_codepage;
  405. }
  406. if (sbi->nls_io) {
  407. unload_nls(sbi->nls_io);
  408. sbi->nls_io = NULL;
  409. }
  410. if (sbi->options.iocharset != fat_default_iocharset) {
  411. kfree(sbi->options.iocharset);
  412. sbi->options.iocharset = fat_default_iocharset;
  413. }
  414. sb->s_fs_info = NULL;
  415. kfree(sbi);
  416. }
  417. static struct kmem_cache *fat_inode_cachep;
  418. static struct inode *fat_alloc_inode(struct super_block *sb)
  419. {
  420. struct msdos_inode_info *ei;
  421. ei = kmem_cache_alloc(fat_inode_cachep, GFP_KERNEL);
  422. if (!ei)
  423. return NULL;
  424. return &ei->vfs_inode;
  425. }
  426. static void fat_destroy_inode(struct inode *inode)
  427. {
  428. kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
  429. }
  430. static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
  431. {
  432. struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
  433. if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
  434. SLAB_CTOR_CONSTRUCTOR) {
  435. spin_lock_init(&ei->cache_lru_lock);
  436. ei->nr_caches = 0;
  437. ei->cache_valid_id = FAT_CACHE_VALID + 1;
  438. INIT_LIST_HEAD(&ei->cache_lru);
  439. INIT_HLIST_NODE(&ei->i_fat_hash);
  440. inode_init_once(&ei->vfs_inode);
  441. }
  442. }
  443. static int __init fat_init_inodecache(void)
  444. {
  445. fat_inode_cachep = kmem_cache_create("fat_inode_cache",
  446. sizeof(struct msdos_inode_info),
  447. 0, (SLAB_RECLAIM_ACCOUNT|
  448. SLAB_MEM_SPREAD),
  449. init_once, NULL);
  450. if (fat_inode_cachep == NULL)
  451. return -ENOMEM;
  452. return 0;
  453. }
  454. static void __exit fat_destroy_inodecache(void)
  455. {
  456. kmem_cache_destroy(fat_inode_cachep);
  457. }
  458. static int fat_remount(struct super_block *sb, int *flags, char *data)
  459. {
  460. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  461. *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
  462. return 0;
  463. }
  464. static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
  465. {
  466. struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
  467. /* If the count of free cluster is still unknown, counts it here. */
  468. if (sbi->free_clusters == -1) {
  469. int err = fat_count_free_clusters(dentry->d_sb);
  470. if (err)
  471. return err;
  472. }
  473. buf->f_type = dentry->d_sb->s_magic;
  474. buf->f_bsize = sbi->cluster_size;
  475. buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
  476. buf->f_bfree = sbi->free_clusters;
  477. buf->f_bavail = sbi->free_clusters;
  478. buf->f_namelen = sbi->options.isvfat ? 260 : 12;
  479. return 0;
  480. }
  481. static int fat_write_inode(struct inode *inode, int wait)
  482. {
  483. struct super_block *sb = inode->i_sb;
  484. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  485. struct buffer_head *bh;
  486. struct msdos_dir_entry *raw_entry;
  487. loff_t i_pos;
  488. int err = 0;
  489. retry:
  490. i_pos = MSDOS_I(inode)->i_pos;
  491. if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
  492. return 0;
  493. lock_kernel();
  494. bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
  495. if (!bh) {
  496. printk(KERN_ERR "FAT: unable to read inode block "
  497. "for updating (i_pos %lld)\n", i_pos);
  498. err = -EIO;
  499. goto out;
  500. }
  501. spin_lock(&sbi->inode_hash_lock);
  502. if (i_pos != MSDOS_I(inode)->i_pos) {
  503. spin_unlock(&sbi->inode_hash_lock);
  504. brelse(bh);
  505. unlock_kernel();
  506. goto retry;
  507. }
  508. raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
  509. [i_pos & (sbi->dir_per_block - 1)];
  510. if (S_ISDIR(inode->i_mode))
  511. raw_entry->size = 0;
  512. else
  513. raw_entry->size = cpu_to_le32(inode->i_size);
  514. raw_entry->attr = fat_attr(inode);
  515. raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
  516. raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
  517. fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
  518. if (sbi->options.isvfat) {
  519. __le16 atime;
  520. fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
  521. fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate);
  522. raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
  523. inode->i_ctime.tv_nsec / 10000000;
  524. }
  525. spin_unlock(&sbi->inode_hash_lock);
  526. mark_buffer_dirty(bh);
  527. if (wait)
  528. err = sync_dirty_buffer(bh);
  529. brelse(bh);
  530. out:
  531. unlock_kernel();
  532. return err;
  533. }
  534. int fat_sync_inode(struct inode *inode)
  535. {
  536. return fat_write_inode(inode, 1);
  537. }
  538. EXPORT_SYMBOL_GPL(fat_sync_inode);
  539. static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
  540. static const struct super_operations fat_sops = {
  541. .alloc_inode = fat_alloc_inode,
  542. .destroy_inode = fat_destroy_inode,
  543. .write_inode = fat_write_inode,
  544. .delete_inode = fat_delete_inode,
  545. .put_super = fat_put_super,
  546. .write_super = fat_write_super,
  547. .statfs = fat_statfs,
  548. .clear_inode = fat_clear_inode,
  549. .remount_fs = fat_remount,
  550. .read_inode = make_bad_inode,
  551. .show_options = fat_show_options,
  552. };
  553. /*
  554. * a FAT file handle with fhtype 3 is
  555. * 0/ i_ino - for fast, reliable lookup if still in the cache
  556. * 1/ i_generation - to see if i_ino is still valid
  557. * bit 0 == 0 iff directory
  558. * 2/ i_pos(8-39) - if ino has changed, but still in cache
  559. * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
  560. * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
  561. *
  562. * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
  563. * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
  564. * of i_logstart is used to store the directory entry offset.
  565. */
  566. static struct dentry *
  567. fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
  568. int (*acceptable)(void *context, struct dentry *de),
  569. void *context)
  570. {
  571. if (fhtype != 3)
  572. return ERR_PTR(-ESTALE);
  573. if (len < 5)
  574. return ERR_PTR(-ESTALE);
  575. return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
  576. }
  577. static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
  578. {
  579. struct inode *inode = NULL;
  580. struct dentry *result;
  581. __u32 *fh = inump;
  582. inode = iget(sb, fh[0]);
  583. if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
  584. if (inode)
  585. iput(inode);
  586. inode = NULL;
  587. }
  588. if (!inode) {
  589. loff_t i_pos;
  590. int i_logstart = fh[3] & 0x0fffffff;
  591. i_pos = (loff_t)fh[2] << 8;
  592. i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
  593. /* try 2 - see if i_pos is in F-d-c
  594. * require i_logstart to be the same
  595. * Will fail if you truncate and then re-write
  596. */
  597. inode = fat_iget(sb, i_pos);
  598. if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
  599. iput(inode);
  600. inode = NULL;
  601. }
  602. }
  603. if (!inode) {
  604. /* For now, do nothing
  605. * What we could do is:
  606. * follow the file starting at fh[4], and record
  607. * the ".." entry, and the name of the fh[2] entry.
  608. * The follow the ".." file finding the next step up.
  609. * This way we build a path to the root of
  610. * the tree. If this works, we lookup the path and so
  611. * get this inode into the cache.
  612. * Finally try the fat_iget lookup again
  613. * If that fails, then weare totally out of luck
  614. * But all that is for another day
  615. */
  616. }
  617. if (!inode)
  618. return ERR_PTR(-ESTALE);
  619. /* now to find a dentry.
  620. * If possible, get a well-connected one
  621. */
  622. result = d_alloc_anon(inode);
  623. if (result == NULL) {
  624. iput(inode);
  625. return ERR_PTR(-ENOMEM);
  626. }
  627. result->d_op = sb->s_root->d_op;
  628. return result;
  629. }
  630. static int
  631. fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
  632. {
  633. int len = *lenp;
  634. struct inode *inode = de->d_inode;
  635. u32 ipos_h, ipos_m, ipos_l;
  636. if (len < 5)
  637. return 255; /* no room */
  638. ipos_h = MSDOS_I(inode)->i_pos >> 8;
  639. ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
  640. ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
  641. *lenp = 5;
  642. fh[0] = inode->i_ino;
  643. fh[1] = inode->i_generation;
  644. fh[2] = ipos_h;
  645. fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
  646. spin_lock(&de->d_lock);
  647. fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
  648. spin_unlock(&de->d_lock);
  649. return 3;
  650. }
  651. static struct dentry *fat_get_parent(struct dentry *child)
  652. {
  653. struct buffer_head *bh;
  654. struct msdos_dir_entry *de;
  655. loff_t i_pos;
  656. struct dentry *parent;
  657. struct inode *inode;
  658. int err;
  659. lock_kernel();
  660. err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
  661. if (err) {
  662. parent = ERR_PTR(err);
  663. goto out;
  664. }
  665. inode = fat_build_inode(child->d_sb, de, i_pos);
  666. brelse(bh);
  667. if (IS_ERR(inode)) {
  668. parent = ERR_PTR(PTR_ERR(inode));
  669. goto out;
  670. }
  671. parent = d_alloc_anon(inode);
  672. if (!parent) {
  673. iput(inode);
  674. parent = ERR_PTR(-ENOMEM);
  675. }
  676. out:
  677. unlock_kernel();
  678. return parent;
  679. }
  680. static struct export_operations fat_export_ops = {
  681. .decode_fh = fat_decode_fh,
  682. .encode_fh = fat_encode_fh,
  683. .get_dentry = fat_get_dentry,
  684. .get_parent = fat_get_parent,
  685. };
  686. static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
  687. {
  688. struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
  689. struct fat_mount_options *opts = &sbi->options;
  690. int isvfat = opts->isvfat;
  691. if (opts->fs_uid != 0)
  692. seq_printf(m, ",uid=%u", opts->fs_uid);
  693. if (opts->fs_gid != 0)
  694. seq_printf(m, ",gid=%u", opts->fs_gid);
  695. seq_printf(m, ",fmask=%04o", opts->fs_fmask);
  696. seq_printf(m, ",dmask=%04o", opts->fs_dmask);
  697. if (sbi->nls_disk)
  698. seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
  699. if (isvfat) {
  700. if (sbi->nls_io)
  701. seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
  702. switch (opts->shortname) {
  703. case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
  704. seq_puts(m, ",shortname=win95");
  705. break;
  706. case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
  707. seq_puts(m, ",shortname=winnt");
  708. break;
  709. case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
  710. seq_puts(m, ",shortname=mixed");
  711. break;
  712. case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
  713. /* seq_puts(m, ",shortname=lower"); */
  714. break;
  715. default:
  716. seq_puts(m, ",shortname=unknown");
  717. break;
  718. }
  719. }
  720. if (opts->name_check != 'n')
  721. seq_printf(m, ",check=%c", opts->name_check);
  722. if (opts->quiet)
  723. seq_puts(m, ",quiet");
  724. if (opts->showexec)
  725. seq_puts(m, ",showexec");
  726. if (opts->sys_immutable)
  727. seq_puts(m, ",sys_immutable");
  728. if (!isvfat) {
  729. if (opts->dotsOK)
  730. seq_puts(m, ",dotsOK=yes");
  731. if (opts->nocase)
  732. seq_puts(m, ",nocase");
  733. } else {
  734. if (opts->utf8)
  735. seq_puts(m, ",utf8");
  736. if (opts->unicode_xlate)
  737. seq_puts(m, ",uni_xlate");
  738. if (!opts->numtail)
  739. seq_puts(m, ",nonumtail");
  740. }
  741. return 0;
  742. }
  743. enum {
  744. Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
  745. Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
  746. Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
  747. Opt_dots, Opt_nodots,
  748. Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
  749. Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
  750. Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
  751. Opt_obsolate, Opt_flush, Opt_err,
  752. };
  753. static match_table_t fat_tokens = {
  754. {Opt_check_r, "check=relaxed"},
  755. {Opt_check_s, "check=strict"},
  756. {Opt_check_n, "check=normal"},
  757. {Opt_check_r, "check=r"},
  758. {Opt_check_s, "check=s"},
  759. {Opt_check_n, "check=n"},
  760. {Opt_uid, "uid=%u"},
  761. {Opt_gid, "gid=%u"},
  762. {Opt_umask, "umask=%o"},
  763. {Opt_dmask, "dmask=%o"},
  764. {Opt_fmask, "fmask=%o"},
  765. {Opt_codepage, "codepage=%u"},
  766. {Opt_nocase, "nocase"},
  767. {Opt_quiet, "quiet"},
  768. {Opt_showexec, "showexec"},
  769. {Opt_debug, "debug"},
  770. {Opt_immutable, "sys_immutable"},
  771. {Opt_obsolate, "conv=binary"},
  772. {Opt_obsolate, "conv=text"},
  773. {Opt_obsolate, "conv=auto"},
  774. {Opt_obsolate, "conv=b"},
  775. {Opt_obsolate, "conv=t"},
  776. {Opt_obsolate, "conv=a"},
  777. {Opt_obsolate, "fat=%u"},
  778. {Opt_obsolate, "blocksize=%u"},
  779. {Opt_obsolate, "cvf_format=%20s"},
  780. {Opt_obsolate, "cvf_options=%100s"},
  781. {Opt_obsolate, "posix"},
  782. {Opt_flush, "flush"},
  783. {Opt_err, NULL},
  784. };
  785. static match_table_t msdos_tokens = {
  786. {Opt_nodots, "nodots"},
  787. {Opt_nodots, "dotsOK=no"},
  788. {Opt_dots, "dots"},
  789. {Opt_dots, "dotsOK=yes"},
  790. {Opt_err, NULL}
  791. };
  792. static match_table_t vfat_tokens = {
  793. {Opt_charset, "iocharset=%s"},
  794. {Opt_shortname_lower, "shortname=lower"},
  795. {Opt_shortname_win95, "shortname=win95"},
  796. {Opt_shortname_winnt, "shortname=winnt"},
  797. {Opt_shortname_mixed, "shortname=mixed"},
  798. {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
  799. {Opt_utf8_no, "utf8=no"},
  800. {Opt_utf8_no, "utf8=false"},
  801. {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
  802. {Opt_utf8_yes, "utf8=yes"},
  803. {Opt_utf8_yes, "utf8=true"},
  804. {Opt_utf8_yes, "utf8"},
  805. {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
  806. {Opt_uni_xl_no, "uni_xlate=no"},
  807. {Opt_uni_xl_no, "uni_xlate=false"},
  808. {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
  809. {Opt_uni_xl_yes, "uni_xlate=yes"},
  810. {Opt_uni_xl_yes, "uni_xlate=true"},
  811. {Opt_uni_xl_yes, "uni_xlate"},
  812. {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
  813. {Opt_nonumtail_no, "nonumtail=no"},
  814. {Opt_nonumtail_no, "nonumtail=false"},
  815. {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
  816. {Opt_nonumtail_yes, "nonumtail=yes"},
  817. {Opt_nonumtail_yes, "nonumtail=true"},
  818. {Opt_nonumtail_yes, "nonumtail"},
  819. {Opt_err, NULL}
  820. };
  821. static int parse_options(char *options, int is_vfat, int silent, int *debug,
  822. struct fat_mount_options *opts)
  823. {
  824. char *p;
  825. substring_t args[MAX_OPT_ARGS];
  826. int option;
  827. char *iocharset;
  828. opts->isvfat = is_vfat;
  829. opts->fs_uid = current->uid;
  830. opts->fs_gid = current->gid;
  831. opts->fs_fmask = opts->fs_dmask = current->fs->umask;
  832. opts->codepage = fat_default_codepage;
  833. opts->iocharset = fat_default_iocharset;
  834. if (is_vfat)
  835. opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
  836. else
  837. opts->shortname = 0;
  838. opts->name_check = 'n';
  839. opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
  840. opts->utf8 = opts->unicode_xlate = 0;
  841. opts->numtail = 1;
  842. opts->nocase = 0;
  843. *debug = 0;
  844. if (!options)
  845. return 0;
  846. while ((p = strsep(&options, ",")) != NULL) {
  847. int token;
  848. if (!*p)
  849. continue;
  850. token = match_token(p, fat_tokens, args);
  851. if (token == Opt_err) {
  852. if (is_vfat)
  853. token = match_token(p, vfat_tokens, args);
  854. else
  855. token = match_token(p, msdos_tokens, args);
  856. }
  857. switch (token) {
  858. case Opt_check_s:
  859. opts->name_check = 's';
  860. break;
  861. case Opt_check_r:
  862. opts->name_check = 'r';
  863. break;
  864. case Opt_check_n:
  865. opts->name_check = 'n';
  866. break;
  867. case Opt_nocase:
  868. if (!is_vfat)
  869. opts->nocase = 1;
  870. else {
  871. /* for backward compatibility */
  872. opts->shortname = VFAT_SFN_DISPLAY_WIN95
  873. | VFAT_SFN_CREATE_WIN95;
  874. }
  875. break;
  876. case Opt_quiet:
  877. opts->quiet = 1;
  878. break;
  879. case Opt_showexec:
  880. opts->showexec = 1;
  881. break;
  882. case Opt_debug:
  883. *debug = 1;
  884. break;
  885. case Opt_immutable:
  886. opts->sys_immutable = 1;
  887. break;
  888. case Opt_uid:
  889. if (match_int(&args[0], &option))
  890. return 0;
  891. opts->fs_uid = option;
  892. break;
  893. case Opt_gid:
  894. if (match_int(&args[0], &option))
  895. return 0;
  896. opts->fs_gid = option;
  897. break;
  898. case Opt_umask:
  899. if (match_octal(&args[0], &option))
  900. return 0;
  901. opts->fs_fmask = opts->fs_dmask = option;
  902. break;
  903. case Opt_dmask:
  904. if (match_octal(&args[0], &option))
  905. return 0;
  906. opts->fs_dmask = option;
  907. break;
  908. case Opt_fmask:
  909. if (match_octal(&args[0], &option))
  910. return 0;
  911. opts->fs_fmask = option;
  912. break;
  913. case Opt_codepage:
  914. if (match_int(&args[0], &option))
  915. return 0;
  916. opts->codepage = option;
  917. break;
  918. case Opt_flush:
  919. opts->flush = 1;
  920. break;
  921. /* msdos specific */
  922. case Opt_dots:
  923. opts->dotsOK = 1;
  924. break;
  925. case Opt_nodots:
  926. opts->dotsOK = 0;
  927. break;
  928. /* vfat specific */
  929. case Opt_charset:
  930. if (opts->iocharset != fat_default_iocharset)
  931. kfree(opts->iocharset);
  932. iocharset = match_strdup(&args[0]);
  933. if (!iocharset)
  934. return -ENOMEM;
  935. opts->iocharset = iocharset;
  936. break;
  937. case Opt_shortname_lower:
  938. opts->shortname = VFAT_SFN_DISPLAY_LOWER
  939. | VFAT_SFN_CREATE_WIN95;
  940. break;
  941. case Opt_shortname_win95:
  942. opts->shortname = VFAT_SFN_DISPLAY_WIN95
  943. | VFAT_SFN_CREATE_WIN95;
  944. break;
  945. case Opt_shortname_winnt:
  946. opts->shortname = VFAT_SFN_DISPLAY_WINNT
  947. | VFAT_SFN_CREATE_WINNT;
  948. break;
  949. case Opt_shortname_mixed:
  950. opts->shortname = VFAT_SFN_DISPLAY_WINNT
  951. | VFAT_SFN_CREATE_WIN95;
  952. break;
  953. case Opt_utf8_no: /* 0 or no or false */
  954. opts->utf8 = 0;
  955. break;
  956. case Opt_utf8_yes: /* empty or 1 or yes or true */
  957. opts->utf8 = 1;
  958. break;
  959. case Opt_uni_xl_no: /* 0 or no or false */
  960. opts->unicode_xlate = 0;
  961. break;
  962. case Opt_uni_xl_yes: /* empty or 1 or yes or true */
  963. opts->unicode_xlate = 1;
  964. break;
  965. case Opt_nonumtail_no: /* 0 or no or false */
  966. opts->numtail = 1; /* negated option */
  967. break;
  968. case Opt_nonumtail_yes: /* empty or 1 or yes or true */
  969. opts->numtail = 0; /* negated option */
  970. break;
  971. /* obsolete mount options */
  972. case Opt_obsolate:
  973. printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
  974. "not supported now\n", p);
  975. break;
  976. /* unknown option */
  977. default:
  978. if (!silent) {
  979. printk(KERN_ERR
  980. "FAT: Unrecognized mount option \"%s\" "
  981. "or missing value\n", p);
  982. }
  983. return -EINVAL;
  984. }
  985. }
  986. /* UTF-8 doesn't provide FAT semantics */
  987. if (!strcmp(opts->iocharset, "utf8")) {
  988. printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
  989. " for FAT filesystems, filesystem will be case sensitive!\n");
  990. }
  991. if (opts->unicode_xlate)
  992. opts->utf8 = 0;
  993. return 0;
  994. }
  995. static int fat_read_root(struct inode *inode)
  996. {
  997. struct super_block *sb = inode->i_sb;
  998. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  999. int error;
  1000. MSDOS_I(inode)->i_pos = 0;
  1001. inode->i_uid = sbi->options.fs_uid;
  1002. inode->i_gid = sbi->options.fs_gid;
  1003. inode->i_version++;
  1004. inode->i_generation = 0;
  1005. inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
  1006. inode->i_op = sbi->dir_ops;
  1007. inode->i_fop = &fat_dir_operations;
  1008. if (sbi->fat_bits == 32) {
  1009. MSDOS_I(inode)->i_start = sbi->root_cluster;
  1010. error = fat_calc_dir_size(inode);
  1011. if (error < 0)
  1012. return error;
  1013. } else {
  1014. MSDOS_I(inode)->i_start = 0;
  1015. inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
  1016. }
  1017. inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
  1018. & ~((loff_t)sbi->cluster_size - 1)) >> 9;
  1019. MSDOS_I(inode)->i_logstart = 0;
  1020. MSDOS_I(inode)->mmu_private = inode->i_size;
  1021. MSDOS_I(inode)->i_attrs = ATTR_NONE;
  1022. inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
  1023. inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
  1024. inode->i_nlink = fat_subdirs(inode)+2;
  1025. return 0;
  1026. }
  1027. /*
  1028. * Read the super block of an MS-DOS FS.
  1029. */
  1030. int fat_fill_super(struct super_block *sb, void *data, int silent,
  1031. const struct inode_operations *fs_dir_inode_ops, int isvfat)
  1032. {
  1033. struct inode *root_inode = NULL;
  1034. struct buffer_head *bh;
  1035. struct fat_boot_sector *b;
  1036. struct msdos_sb_info *sbi;
  1037. u16 logical_sector_size;
  1038. u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
  1039. int debug;
  1040. unsigned int media;
  1041. long error;
  1042. char buf[50];
  1043. sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
  1044. if (!sbi)
  1045. return -ENOMEM;
  1046. sb->s_fs_info = sbi;
  1047. sb->s_flags |= MS_NODIRATIME;
  1048. sb->s_magic = MSDOS_SUPER_MAGIC;
  1049. sb->s_op = &fat_sops;
  1050. sb->s_export_op = &fat_export_ops;
  1051. sbi->dir_ops = fs_dir_inode_ops;
  1052. error = parse_options(data, isvfat, silent, &debug, &sbi->options);
  1053. if (error)
  1054. goto out_fail;
  1055. error = -EIO;
  1056. sb_min_blocksize(sb, 512);
  1057. bh = sb_bread(sb, 0);
  1058. if (bh == NULL) {
  1059. printk(KERN_ERR "FAT: unable to read boot sector\n");
  1060. goto out_fail;
  1061. }
  1062. b = (struct fat_boot_sector *) bh->b_data;
  1063. if (!b->reserved) {
  1064. if (!silent)
  1065. printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
  1066. brelse(bh);
  1067. goto out_invalid;
  1068. }
  1069. if (!b->fats) {
  1070. if (!silent)
  1071. printk(KERN_ERR "FAT: bogus number of FAT structure\n");
  1072. brelse(bh);
  1073. goto out_invalid;
  1074. }
  1075. /*
  1076. * Earlier we checked here that b->secs_track and b->head are nonzero,
  1077. * but it turns out valid FAT filesystems can have zero there.
  1078. */
  1079. media = b->media;
  1080. if (!FAT_VALID_MEDIA(media)) {
  1081. if (!silent)
  1082. printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
  1083. media);
  1084. brelse(bh);
  1085. goto out_invalid;
  1086. }
  1087. logical_sector_size =
  1088. le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
  1089. if (!logical_sector_size
  1090. || (logical_sector_size & (logical_sector_size - 1))
  1091. || (logical_sector_size < 512)
  1092. || (PAGE_CACHE_SIZE < logical_sector_size)) {
  1093. if (!silent)
  1094. printk(KERN_ERR "FAT: bogus logical sector size %u\n",
  1095. logical_sector_size);
  1096. brelse(bh);
  1097. goto out_invalid;
  1098. }
  1099. sbi->sec_per_clus = b->sec_per_clus;
  1100. if (!sbi->sec_per_clus
  1101. || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
  1102. if (!silent)
  1103. printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
  1104. sbi->sec_per_clus);
  1105. brelse(bh);
  1106. goto out_invalid;
  1107. }
  1108. if (logical_sector_size < sb->s_blocksize) {
  1109. printk(KERN_ERR "FAT: logical sector size too small for device"
  1110. " (logical sector size = %u)\n", logical_sector_size);
  1111. brelse(bh);
  1112. goto out_fail;
  1113. }
  1114. if (logical_sector_size > sb->s_blocksize) {
  1115. brelse(bh);
  1116. if (!sb_set_blocksize(sb, logical_sector_size)) {
  1117. printk(KERN_ERR "FAT: unable to set blocksize %u\n",
  1118. logical_sector_size);
  1119. goto out_fail;
  1120. }
  1121. bh = sb_bread(sb, 0);
  1122. if (bh == NULL) {
  1123. printk(KERN_ERR "FAT: unable to read boot sector"
  1124. " (logical sector size = %lu)\n",
  1125. sb->s_blocksize);
  1126. goto out_fail;
  1127. }
  1128. b = (struct fat_boot_sector *) bh->b_data;
  1129. }
  1130. sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
  1131. sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
  1132. sbi->fats = b->fats;
  1133. sbi->fat_bits = 0; /* Don't know yet */
  1134. sbi->fat_start = le16_to_cpu(b->reserved);
  1135. sbi->fat_length = le16_to_cpu(b->fat_length);
  1136. sbi->root_cluster = 0;
  1137. sbi->free_clusters = -1; /* Don't know yet */
  1138. sbi->prev_free = FAT_START_ENT;
  1139. if (!sbi->fat_length && b->fat32_length) {
  1140. struct fat_boot_fsinfo *fsinfo;
  1141. struct buffer_head *fsinfo_bh;
  1142. /* Must be FAT32 */
  1143. sbi->fat_bits = 32;
  1144. sbi->fat_length = le32_to_cpu(b->fat32_length);
  1145. sbi->root_cluster = le32_to_cpu(b->root_cluster);
  1146. sb->s_maxbytes = 0xffffffff;
  1147. /* MC - if info_sector is 0, don't multiply by 0 */
  1148. sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
  1149. if (sbi->fsinfo_sector == 0)
  1150. sbi->fsinfo_sector = 1;
  1151. fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
  1152. if (fsinfo_bh == NULL) {
  1153. printk(KERN_ERR "FAT: bread failed, FSINFO block"
  1154. " (sector = %lu)\n", sbi->fsinfo_sector);
  1155. brelse(bh);
  1156. goto out_fail;
  1157. }
  1158. fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
  1159. if (!IS_FSINFO(fsinfo)) {
  1160. printk(KERN_WARNING
  1161. "FAT: Did not find valid FSINFO signature.\n"
  1162. " Found signature1 0x%08x signature2 0x%08x"
  1163. " (sector = %lu)\n",
  1164. le32_to_cpu(fsinfo->signature1),
  1165. le32_to_cpu(fsinfo->signature2),
  1166. sbi->fsinfo_sector);
  1167. } else {
  1168. sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
  1169. sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
  1170. }
  1171. brelse(fsinfo_bh);
  1172. }
  1173. sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
  1174. sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
  1175. sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
  1176. sbi->dir_entries =
  1177. le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
  1178. if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
  1179. if (!silent)
  1180. printk(KERN_ERR "FAT: bogus directroy-entries per block"
  1181. " (%u)\n", sbi->dir_entries);
  1182. brelse(bh);
  1183. goto out_invalid;
  1184. }
  1185. rootdir_sectors = sbi->dir_entries
  1186. * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
  1187. sbi->data_start = sbi->dir_start + rootdir_sectors;
  1188. total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
  1189. if (total_sectors == 0)
  1190. total_sectors = le32_to_cpu(b->total_sect);
  1191. total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
  1192. if (sbi->fat_bits != 32)
  1193. sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
  1194. /* check that FAT table does not overflow */
  1195. fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
  1196. total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
  1197. if (total_clusters > MAX_FAT(sb)) {
  1198. if (!silent)
  1199. printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
  1200. total_clusters);
  1201. brelse(bh);
  1202. goto out_invalid;
  1203. }
  1204. sbi->max_cluster = total_clusters + FAT_START_ENT;
  1205. /* check the free_clusters, it's not necessarily correct */
  1206. if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
  1207. sbi->free_clusters = -1;
  1208. /* check the prev_free, it's not necessarily correct */
  1209. sbi->prev_free %= sbi->max_cluster;
  1210. if (sbi->prev_free < FAT_START_ENT)
  1211. sbi->prev_free = FAT_START_ENT;
  1212. brelse(bh);
  1213. /* set up enough so that it can read an inode */
  1214. fat_hash_init(sb);
  1215. fat_ent_access_init(sb);
  1216. /*
  1217. * The low byte of FAT's first entry must have same value with
  1218. * media-field. But in real world, too many devices is
  1219. * writing wrong value. So, removed that validity check.
  1220. *
  1221. * if (FAT_FIRST_ENT(sb, media) != first)
  1222. */
  1223. error = -EINVAL;
  1224. sprintf(buf, "cp%d", sbi->options.codepage);
  1225. sbi->nls_disk = load_nls(buf);
  1226. if (!sbi->nls_disk) {
  1227. printk(KERN_ERR "FAT: codepage %s not found\n", buf);
  1228. goto out_fail;
  1229. }
  1230. /* FIXME: utf8 is using iocharset for upper/lower conversion */
  1231. if (sbi->options.isvfat) {
  1232. sbi->nls_io = load_nls(sbi->options.iocharset);
  1233. if (!sbi->nls_io) {
  1234. printk(KERN_ERR "FAT: IO charset %s not found\n",
  1235. sbi->options.iocharset);
  1236. goto out_fail;
  1237. }
  1238. }
  1239. error = -ENOMEM;
  1240. root_inode = new_inode(sb);
  1241. if (!root_inode)
  1242. goto out_fail;
  1243. root_inode->i_ino = MSDOS_ROOT_INO;
  1244. root_inode->i_version = 1;
  1245. error = fat_read_root(root_inode);
  1246. if (error < 0)
  1247. goto out_fail;
  1248. error = -ENOMEM;
  1249. insert_inode_hash(root_inode);
  1250. sb->s_root = d_alloc_root(root_inode);
  1251. if (!sb->s_root) {
  1252. printk(KERN_ERR "FAT: get root inode failed\n");
  1253. goto out_fail;
  1254. }
  1255. return 0;
  1256. out_invalid:
  1257. error = -EINVAL;
  1258. if (!silent)
  1259. printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
  1260. " on dev %s.\n", sb->s_id);
  1261. out_fail:
  1262. if (root_inode)
  1263. iput(root_inode);
  1264. if (sbi->nls_io)
  1265. unload_nls(sbi->nls_io);
  1266. if (sbi->nls_disk)
  1267. unload_nls(sbi->nls_disk);
  1268. if (sbi->options.iocharset != fat_default_iocharset)
  1269. kfree(sbi->options.iocharset);
  1270. sb->s_fs_info = NULL;
  1271. kfree(sbi);
  1272. return error;
  1273. }
  1274. EXPORT_SYMBOL_GPL(fat_fill_super);
  1275. /*
  1276. * helper function for fat_flush_inodes. This writes both the inode
  1277. * and the file data blocks, waiting for in flight data blocks before
  1278. * the start of the call. It does not wait for any io started
  1279. * during the call
  1280. */
  1281. static int writeback_inode(struct inode *inode)
  1282. {
  1283. int ret;
  1284. struct address_space *mapping = inode->i_mapping;
  1285. struct writeback_control wbc = {
  1286. .sync_mode = WB_SYNC_NONE,
  1287. .nr_to_write = 0,
  1288. };
  1289. /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
  1290. * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
  1291. * and filemap_fdatawrite is used for the data blocks
  1292. */
  1293. ret = sync_inode(inode, &wbc);
  1294. if (!ret)
  1295. ret = filemap_fdatawrite(mapping);
  1296. return ret;
  1297. }
  1298. /*
  1299. * write data and metadata corresponding to i1 and i2. The io is
  1300. * started but we do not wait for any of it to finish.
  1301. *
  1302. * filemap_flush is used for the block device, so if there is a dirty
  1303. * page for a block already in flight, we will not wait and start the
  1304. * io over again
  1305. */
  1306. int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
  1307. {
  1308. int ret = 0;
  1309. if (!MSDOS_SB(sb)->options.flush)
  1310. return 0;
  1311. if (i1)
  1312. ret = writeback_inode(i1);
  1313. if (!ret && i2)
  1314. ret = writeback_inode(i2);
  1315. if (!ret) {
  1316. struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
  1317. ret = filemap_flush(mapping);
  1318. }
  1319. return ret;
  1320. }
  1321. EXPORT_SYMBOL_GPL(fat_flush_inodes);
  1322. static int __init init_fat_fs(void)
  1323. {
  1324. int err;
  1325. err = fat_cache_init();
  1326. if (err)
  1327. return err;
  1328. err = fat_init_inodecache();
  1329. if (err)
  1330. goto failed;
  1331. return 0;
  1332. failed:
  1333. fat_cache_destroy();
  1334. return err;
  1335. }
  1336. static void __exit exit_fat_fs(void)
  1337. {
  1338. fat_cache_destroy();
  1339. fat_destroy_inodecache();
  1340. }
  1341. module_init(init_fat_fs)
  1342. module_exit(exit_fat_fs)
  1343. MODULE_LICENSE("GPL");