inode.c 42 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/seq_file.h>
  17. #include <linux/pagemap.h>
  18. #include <linux/mpage.h>
  19. #include <linux/buffer_head.h>
  20. #include <linux/mount.h>
  21. #include <linux/aio.h>
  22. #include <linux/vfs.h>
  23. #include <linux/parser.h>
  24. #include <linux/uio.h>
  25. #include <linux/writeback.h>
  26. #include <linux/log2.h>
  27. #include <linux/hash.h>
  28. #include <linux/blkdev.h>
  29. #include <asm/unaligned.h>
  30. #include "fat.h"
  31. #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
  32. /* if user don't select VFAT, this is undefined. */
  33. #define CONFIG_FAT_DEFAULT_IOCHARSET ""
  34. #endif
  35. static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
  36. static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
  37. static int fat_add_cluster(struct inode *inode)
  38. {
  39. int err, cluster;
  40. err = fat_alloc_clusters(inode, &cluster, 1);
  41. if (err)
  42. return err;
  43. /* FIXME: this cluster should be added after data of this
  44. * cluster is writed */
  45. err = fat_chain_add(inode, cluster, 1);
  46. if (err)
  47. fat_free_clusters(inode, cluster);
  48. return err;
  49. }
  50. static inline int __fat_get_block(struct inode *inode, sector_t iblock,
  51. unsigned long *max_blocks,
  52. struct buffer_head *bh_result, int create)
  53. {
  54. struct super_block *sb = inode->i_sb;
  55. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  56. unsigned long mapped_blocks;
  57. sector_t phys;
  58. int err, offset;
  59. err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
  60. if (err)
  61. return err;
  62. if (phys) {
  63. map_bh(bh_result, sb, phys);
  64. *max_blocks = min(mapped_blocks, *max_blocks);
  65. return 0;
  66. }
  67. if (!create)
  68. return 0;
  69. if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
  70. fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
  71. MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
  72. return -EIO;
  73. }
  74. offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
  75. if (!offset) {
  76. /* TODO: multiple cluster allocation would be desirable. */
  77. err = fat_add_cluster(inode);
  78. if (err)
  79. return err;
  80. }
  81. /* available blocks on this cluster */
  82. mapped_blocks = sbi->sec_per_clus - offset;
  83. *max_blocks = min(mapped_blocks, *max_blocks);
  84. MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
  85. err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
  86. if (err)
  87. return err;
  88. BUG_ON(!phys);
  89. BUG_ON(*max_blocks != mapped_blocks);
  90. set_buffer_new(bh_result);
  91. map_bh(bh_result, sb, phys);
  92. return 0;
  93. }
  94. static int fat_get_block(struct inode *inode, sector_t iblock,
  95. struct buffer_head *bh_result, int create)
  96. {
  97. struct super_block *sb = inode->i_sb;
  98. unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
  99. int err;
  100. err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
  101. if (err)
  102. return err;
  103. bh_result->b_size = max_blocks << sb->s_blocksize_bits;
  104. return 0;
  105. }
  106. static int fat_writepage(struct page *page, struct writeback_control *wbc)
  107. {
  108. return block_write_full_page(page, fat_get_block, wbc);
  109. }
  110. static int fat_writepages(struct address_space *mapping,
  111. struct writeback_control *wbc)
  112. {
  113. return mpage_writepages(mapping, wbc, fat_get_block);
  114. }
  115. static int fat_readpage(struct file *file, struct page *page)
  116. {
  117. return mpage_readpage(page, fat_get_block);
  118. }
  119. static int fat_readpages(struct file *file, struct address_space *mapping,
  120. struct list_head *pages, unsigned nr_pages)
  121. {
  122. return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
  123. }
  124. static void fat_write_failed(struct address_space *mapping, loff_t to)
  125. {
  126. struct inode *inode = mapping->host;
  127. if (to > inode->i_size) {
  128. truncate_pagecache(inode, to, inode->i_size);
  129. fat_truncate_blocks(inode, inode->i_size);
  130. }
  131. }
  132. static int fat_write_begin(struct file *file, struct address_space *mapping,
  133. loff_t pos, unsigned len, unsigned flags,
  134. struct page **pagep, void **fsdata)
  135. {
  136. int err;
  137. *pagep = NULL;
  138. err = cont_write_begin(file, mapping, pos, len, flags,
  139. pagep, fsdata, fat_get_block,
  140. &MSDOS_I(mapping->host)->mmu_private);
  141. if (err < 0)
  142. fat_write_failed(mapping, pos + len);
  143. return err;
  144. }
  145. static int fat_write_end(struct file *file, struct address_space *mapping,
  146. loff_t pos, unsigned len, unsigned copied,
  147. struct page *pagep, void *fsdata)
  148. {
  149. struct inode *inode = mapping->host;
  150. int err;
  151. err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
  152. if (err < len)
  153. fat_write_failed(mapping, pos + len);
  154. if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
  155. inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
  156. MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
  157. mark_inode_dirty(inode);
  158. }
  159. return err;
  160. }
  161. static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
  162. const struct iovec *iov,
  163. loff_t offset, unsigned long nr_segs)
  164. {
  165. struct file *file = iocb->ki_filp;
  166. struct address_space *mapping = file->f_mapping;
  167. struct inode *inode = mapping->host;
  168. ssize_t ret;
  169. if (rw == WRITE) {
  170. /*
  171. * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
  172. * so we need to update the ->mmu_private to block boundary.
  173. *
  174. * But we must fill the remaining area or hole by nul for
  175. * updating ->mmu_private.
  176. *
  177. * Return 0, and fallback to normal buffered write.
  178. */
  179. loff_t size = offset + iov_length(iov, nr_segs);
  180. if (MSDOS_I(inode)->mmu_private < size)
  181. return 0;
  182. }
  183. /*
  184. * FAT need to use the DIO_LOCKING for avoiding the race
  185. * condition of fat_get_block() and ->truncate().
  186. */
  187. ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
  188. fat_get_block);
  189. if (ret < 0 && (rw & WRITE))
  190. fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
  191. return ret;
  192. }
  193. static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
  194. {
  195. sector_t blocknr;
  196. /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
  197. down_read(&MSDOS_I(mapping->host)->truncate_lock);
  198. blocknr = generic_block_bmap(mapping, block, fat_get_block);
  199. up_read(&MSDOS_I(mapping->host)->truncate_lock);
  200. return blocknr;
  201. }
  202. static const struct address_space_operations fat_aops = {
  203. .readpage = fat_readpage,
  204. .readpages = fat_readpages,
  205. .writepage = fat_writepage,
  206. .writepages = fat_writepages,
  207. .write_begin = fat_write_begin,
  208. .write_end = fat_write_end,
  209. .direct_IO = fat_direct_IO,
  210. .bmap = _fat_bmap
  211. };
  212. /*
  213. * New FAT inode stuff. We do the following:
  214. * a) i_ino is constant and has nothing with on-disk location.
  215. * b) FAT manages its own cache of directory entries.
  216. * c) *This* cache is indexed by on-disk location.
  217. * d) inode has an associated directory entry, all right, but
  218. * it may be unhashed.
  219. * e) currently entries are stored within struct inode. That should
  220. * change.
  221. * f) we deal with races in the following way:
  222. * 1. readdir() and lookup() do FAT-dir-cache lookup.
  223. * 2. rename() unhashes the F-d-c entry and rehashes it in
  224. * a new place.
  225. * 3. unlink() and rmdir() unhash F-d-c entry.
  226. * 4. fat_write_inode() checks whether the thing is unhashed.
  227. * If it is we silently return. If it isn't we do bread(),
  228. * check if the location is still valid and retry if it
  229. * isn't. Otherwise we do changes.
  230. * 5. Spinlock is used to protect hash/unhash/location check/lookup
  231. * 6. fat_evict_inode() unhashes the F-d-c entry.
  232. * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
  233. * and consider negative result as cache miss.
  234. */
  235. static void fat_hash_init(struct super_block *sb)
  236. {
  237. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  238. int i;
  239. spin_lock_init(&sbi->inode_hash_lock);
  240. for (i = 0; i < FAT_HASH_SIZE; i++)
  241. INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
  242. }
  243. static inline unsigned long fat_hash(loff_t i_pos)
  244. {
  245. return hash_32(i_pos, FAT_HASH_BITS);
  246. }
  247. static void dir_hash_init(struct super_block *sb)
  248. {
  249. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  250. int i;
  251. spin_lock_init(&sbi->dir_hash_lock);
  252. for (i = 0; i < FAT_HASH_SIZE; i++)
  253. INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
  254. }
  255. void fat_attach(struct inode *inode, loff_t i_pos)
  256. {
  257. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  258. if (inode->i_ino != MSDOS_ROOT_INO) {
  259. struct hlist_head *head = sbi->inode_hashtable
  260. + fat_hash(i_pos);
  261. spin_lock(&sbi->inode_hash_lock);
  262. MSDOS_I(inode)->i_pos = i_pos;
  263. hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
  264. spin_unlock(&sbi->inode_hash_lock);
  265. }
  266. /* If NFS support is enabled, cache the mapping of start cluster
  267. * to directory inode. This is used during reconnection of
  268. * dentries to the filesystem root.
  269. */
  270. if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
  271. struct hlist_head *d_head = sbi->dir_hashtable;
  272. d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
  273. spin_lock(&sbi->dir_hash_lock);
  274. hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
  275. spin_unlock(&sbi->dir_hash_lock);
  276. }
  277. }
  278. EXPORT_SYMBOL_GPL(fat_attach);
  279. void fat_detach(struct inode *inode)
  280. {
  281. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  282. spin_lock(&sbi->inode_hash_lock);
  283. MSDOS_I(inode)->i_pos = 0;
  284. hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
  285. spin_unlock(&sbi->inode_hash_lock);
  286. if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
  287. spin_lock(&sbi->dir_hash_lock);
  288. hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
  289. spin_unlock(&sbi->dir_hash_lock);
  290. }
  291. }
  292. EXPORT_SYMBOL_GPL(fat_detach);
  293. struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
  294. {
  295. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  296. struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
  297. struct msdos_inode_info *i;
  298. struct inode *inode = NULL;
  299. spin_lock(&sbi->inode_hash_lock);
  300. hlist_for_each_entry(i, head, i_fat_hash) {
  301. BUG_ON(i->vfs_inode.i_sb != sb);
  302. if (i->i_pos != i_pos)
  303. continue;
  304. inode = igrab(&i->vfs_inode);
  305. if (inode)
  306. break;
  307. }
  308. spin_unlock(&sbi->inode_hash_lock);
  309. return inode;
  310. }
  311. static int is_exec(unsigned char *extension)
  312. {
  313. unsigned char *exe_extensions = "EXECOMBAT", *walk;
  314. for (walk = exe_extensions; *walk; walk += 3)
  315. if (!strncmp(extension, walk, 3))
  316. return 1;
  317. return 0;
  318. }
  319. static int fat_calc_dir_size(struct inode *inode)
  320. {
  321. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  322. int ret, fclus, dclus;
  323. inode->i_size = 0;
  324. if (MSDOS_I(inode)->i_start == 0)
  325. return 0;
  326. ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
  327. if (ret < 0)
  328. return ret;
  329. inode->i_size = (fclus + 1) << sbi->cluster_bits;
  330. return 0;
  331. }
  332. /* doesn't deal with root inode */
  333. int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
  334. {
  335. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  336. int error;
  337. MSDOS_I(inode)->i_pos = 0;
  338. inode->i_uid = sbi->options.fs_uid;
  339. inode->i_gid = sbi->options.fs_gid;
  340. inode->i_version++;
  341. inode->i_generation = get_seconds();
  342. if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
  343. inode->i_generation &= ~1;
  344. inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
  345. inode->i_op = sbi->dir_ops;
  346. inode->i_fop = &fat_dir_operations;
  347. MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
  348. MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
  349. error = fat_calc_dir_size(inode);
  350. if (error < 0)
  351. return error;
  352. MSDOS_I(inode)->mmu_private = inode->i_size;
  353. set_nlink(inode, fat_subdirs(inode));
  354. } else { /* not a directory */
  355. inode->i_generation |= 1;
  356. inode->i_mode = fat_make_mode(sbi, de->attr,
  357. ((sbi->options.showexec && !is_exec(de->name + 8))
  358. ? S_IRUGO|S_IWUGO : S_IRWXUGO));
  359. MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
  360. MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
  361. inode->i_size = le32_to_cpu(de->size);
  362. inode->i_op = &fat_file_inode_operations;
  363. inode->i_fop = &fat_file_operations;
  364. inode->i_mapping->a_ops = &fat_aops;
  365. MSDOS_I(inode)->mmu_private = inode->i_size;
  366. }
  367. if (de->attr & ATTR_SYS) {
  368. if (sbi->options.sys_immutable)
  369. inode->i_flags |= S_IMMUTABLE;
  370. }
  371. fat_save_attrs(inode, de->attr);
  372. inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
  373. & ~((loff_t)sbi->cluster_size - 1)) >> 9;
  374. fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
  375. if (sbi->options.isvfat) {
  376. fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
  377. de->cdate, de->ctime_cs);
  378. fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
  379. } else
  380. inode->i_ctime = inode->i_atime = inode->i_mtime;
  381. return 0;
  382. }
  383. static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
  384. {
  385. if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
  386. mutex_lock(&sbi->nfs_build_inode_lock);
  387. }
  388. static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
  389. {
  390. if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
  391. mutex_unlock(&sbi->nfs_build_inode_lock);
  392. }
  393. struct inode *fat_build_inode(struct super_block *sb,
  394. struct msdos_dir_entry *de, loff_t i_pos)
  395. {
  396. struct inode *inode;
  397. int err;
  398. fat_lock_build_inode(MSDOS_SB(sb));
  399. inode = fat_iget(sb, i_pos);
  400. if (inode)
  401. goto out;
  402. inode = new_inode(sb);
  403. if (!inode) {
  404. inode = ERR_PTR(-ENOMEM);
  405. goto out;
  406. }
  407. inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
  408. inode->i_version = 1;
  409. err = fat_fill_inode(inode, de);
  410. if (err) {
  411. iput(inode);
  412. inode = ERR_PTR(err);
  413. goto out;
  414. }
  415. fat_attach(inode, i_pos);
  416. insert_inode_hash(inode);
  417. out:
  418. fat_unlock_build_inode(MSDOS_SB(sb));
  419. return inode;
  420. }
  421. EXPORT_SYMBOL_GPL(fat_build_inode);
  422. static void fat_evict_inode(struct inode *inode)
  423. {
  424. truncate_inode_pages(&inode->i_data, 0);
  425. if (!inode->i_nlink) {
  426. inode->i_size = 0;
  427. fat_truncate_blocks(inode, 0);
  428. }
  429. invalidate_inode_buffers(inode);
  430. clear_inode(inode);
  431. fat_cache_inval_inode(inode);
  432. fat_detach(inode);
  433. }
  434. static void fat_set_state(struct super_block *sb,
  435. unsigned int set, unsigned int force)
  436. {
  437. struct buffer_head *bh;
  438. struct fat_boot_sector *b;
  439. struct msdos_sb_info *sbi = sb->s_fs_info;
  440. /* do not change any thing if mounted read only */
  441. if ((sb->s_flags & MS_RDONLY) && !force)
  442. return;
  443. /* do not change state if fs was dirty */
  444. if (sbi->dirty) {
  445. /* warn only on set (mount). */
  446. if (set)
  447. fat_msg(sb, KERN_WARNING, "Volume was not properly "
  448. "unmounted. Some data may be corrupt. "
  449. "Please run fsck.");
  450. return;
  451. }
  452. bh = sb_bread(sb, 0);
  453. if (bh == NULL) {
  454. fat_msg(sb, KERN_ERR, "unable to read boot sector "
  455. "to mark fs as dirty");
  456. return;
  457. }
  458. b = (struct fat_boot_sector *) bh->b_data;
  459. if (sbi->fat_bits == 32) {
  460. if (set)
  461. b->fat32.state |= FAT_STATE_DIRTY;
  462. else
  463. b->fat32.state &= ~FAT_STATE_DIRTY;
  464. } else /* fat 16 and 12 */ {
  465. if (set)
  466. b->fat16.state |= FAT_STATE_DIRTY;
  467. else
  468. b->fat16.state &= ~FAT_STATE_DIRTY;
  469. }
  470. mark_buffer_dirty(bh);
  471. sync_dirty_buffer(bh);
  472. brelse(bh);
  473. }
  474. static void fat_put_super(struct super_block *sb)
  475. {
  476. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  477. fat_set_state(sb, 0, 0);
  478. iput(sbi->fsinfo_inode);
  479. iput(sbi->fat_inode);
  480. unload_nls(sbi->nls_disk);
  481. unload_nls(sbi->nls_io);
  482. if (sbi->options.iocharset != fat_default_iocharset)
  483. kfree(sbi->options.iocharset);
  484. sb->s_fs_info = NULL;
  485. kfree(sbi);
  486. }
  487. static struct kmem_cache *fat_inode_cachep;
  488. static struct inode *fat_alloc_inode(struct super_block *sb)
  489. {
  490. struct msdos_inode_info *ei;
  491. ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
  492. if (!ei)
  493. return NULL;
  494. init_rwsem(&ei->truncate_lock);
  495. return &ei->vfs_inode;
  496. }
  497. static void fat_i_callback(struct rcu_head *head)
  498. {
  499. struct inode *inode = container_of(head, struct inode, i_rcu);
  500. kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
  501. }
  502. static void fat_destroy_inode(struct inode *inode)
  503. {
  504. call_rcu(&inode->i_rcu, fat_i_callback);
  505. }
  506. static void init_once(void *foo)
  507. {
  508. struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
  509. spin_lock_init(&ei->cache_lru_lock);
  510. ei->nr_caches = 0;
  511. ei->cache_valid_id = FAT_CACHE_VALID + 1;
  512. INIT_LIST_HEAD(&ei->cache_lru);
  513. INIT_HLIST_NODE(&ei->i_fat_hash);
  514. INIT_HLIST_NODE(&ei->i_dir_hash);
  515. inode_init_once(&ei->vfs_inode);
  516. }
  517. static int __init fat_init_inodecache(void)
  518. {
  519. fat_inode_cachep = kmem_cache_create("fat_inode_cache",
  520. sizeof(struct msdos_inode_info),
  521. 0, (SLAB_RECLAIM_ACCOUNT|
  522. SLAB_MEM_SPREAD),
  523. init_once);
  524. if (fat_inode_cachep == NULL)
  525. return -ENOMEM;
  526. return 0;
  527. }
  528. static void __exit fat_destroy_inodecache(void)
  529. {
  530. /*
  531. * Make sure all delayed rcu free inodes are flushed before we
  532. * destroy cache.
  533. */
  534. rcu_barrier();
  535. kmem_cache_destroy(fat_inode_cachep);
  536. }
  537. static int fat_remount(struct super_block *sb, int *flags, char *data)
  538. {
  539. int new_rdonly;
  540. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  541. *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
  542. /* make sure we update state on remount. */
  543. new_rdonly = *flags & MS_RDONLY;
  544. if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
  545. if (new_rdonly)
  546. fat_set_state(sb, 0, 0);
  547. else
  548. fat_set_state(sb, 1, 1);
  549. }
  550. return 0;
  551. }
  552. static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
  553. {
  554. struct super_block *sb = dentry->d_sb;
  555. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  556. u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  557. /* If the count of free cluster is still unknown, counts it here. */
  558. if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
  559. int err = fat_count_free_clusters(dentry->d_sb);
  560. if (err)
  561. return err;
  562. }
  563. buf->f_type = dentry->d_sb->s_magic;
  564. buf->f_bsize = sbi->cluster_size;
  565. buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
  566. buf->f_bfree = sbi->free_clusters;
  567. buf->f_bavail = sbi->free_clusters;
  568. buf->f_fsid.val[0] = (u32)id;
  569. buf->f_fsid.val[1] = (u32)(id >> 32);
  570. buf->f_namelen =
  571. (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
  572. return 0;
  573. }
  574. static int __fat_write_inode(struct inode *inode, int wait)
  575. {
  576. struct super_block *sb = inode->i_sb;
  577. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  578. struct buffer_head *bh;
  579. struct msdos_dir_entry *raw_entry;
  580. loff_t i_pos;
  581. sector_t blocknr;
  582. int err, offset;
  583. if (inode->i_ino == MSDOS_ROOT_INO)
  584. return 0;
  585. retry:
  586. i_pos = fat_i_pos_read(sbi, inode);
  587. if (!i_pos)
  588. return 0;
  589. fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
  590. bh = sb_bread(sb, blocknr);
  591. if (!bh) {
  592. fat_msg(sb, KERN_ERR, "unable to read inode block "
  593. "for updating (i_pos %lld)", i_pos);
  594. return -EIO;
  595. }
  596. spin_lock(&sbi->inode_hash_lock);
  597. if (i_pos != MSDOS_I(inode)->i_pos) {
  598. spin_unlock(&sbi->inode_hash_lock);
  599. brelse(bh);
  600. goto retry;
  601. }
  602. raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
  603. if (S_ISDIR(inode->i_mode))
  604. raw_entry->size = 0;
  605. else
  606. raw_entry->size = cpu_to_le32(inode->i_size);
  607. raw_entry->attr = fat_make_attrs(inode);
  608. fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
  609. fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
  610. &raw_entry->date, NULL);
  611. if (sbi->options.isvfat) {
  612. __le16 atime;
  613. fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
  614. &raw_entry->cdate, &raw_entry->ctime_cs);
  615. fat_time_unix2fat(sbi, &inode->i_atime, &atime,
  616. &raw_entry->adate, NULL);
  617. }
  618. spin_unlock(&sbi->inode_hash_lock);
  619. mark_buffer_dirty(bh);
  620. err = 0;
  621. if (wait)
  622. err = sync_dirty_buffer(bh);
  623. brelse(bh);
  624. return err;
  625. }
  626. static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
  627. {
  628. int err;
  629. if (inode->i_ino == MSDOS_FSINFO_INO) {
  630. struct super_block *sb = inode->i_sb;
  631. mutex_lock(&MSDOS_SB(sb)->s_lock);
  632. err = fat_clusters_flush(sb);
  633. mutex_unlock(&MSDOS_SB(sb)->s_lock);
  634. } else
  635. err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
  636. return err;
  637. }
  638. int fat_sync_inode(struct inode *inode)
  639. {
  640. return __fat_write_inode(inode, 1);
  641. }
  642. EXPORT_SYMBOL_GPL(fat_sync_inode);
  643. static int fat_show_options(struct seq_file *m, struct dentry *root);
  644. static const struct super_operations fat_sops = {
  645. .alloc_inode = fat_alloc_inode,
  646. .destroy_inode = fat_destroy_inode,
  647. .write_inode = fat_write_inode,
  648. .evict_inode = fat_evict_inode,
  649. .put_super = fat_put_super,
  650. .statfs = fat_statfs,
  651. .remount_fs = fat_remount,
  652. .show_options = fat_show_options,
  653. };
  654. static int fat_show_options(struct seq_file *m, struct dentry *root)
  655. {
  656. struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
  657. struct fat_mount_options *opts = &sbi->options;
  658. int isvfat = opts->isvfat;
  659. if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
  660. seq_printf(m, ",uid=%u",
  661. from_kuid_munged(&init_user_ns, opts->fs_uid));
  662. if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
  663. seq_printf(m, ",gid=%u",
  664. from_kgid_munged(&init_user_ns, opts->fs_gid));
  665. seq_printf(m, ",fmask=%04o", opts->fs_fmask);
  666. seq_printf(m, ",dmask=%04o", opts->fs_dmask);
  667. if (opts->allow_utime)
  668. seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
  669. if (sbi->nls_disk)
  670. /* strip "cp" prefix from displayed option */
  671. seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
  672. if (isvfat) {
  673. if (sbi->nls_io)
  674. seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
  675. switch (opts->shortname) {
  676. case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
  677. seq_puts(m, ",shortname=win95");
  678. break;
  679. case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
  680. seq_puts(m, ",shortname=winnt");
  681. break;
  682. case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
  683. seq_puts(m, ",shortname=mixed");
  684. break;
  685. case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
  686. seq_puts(m, ",shortname=lower");
  687. break;
  688. default:
  689. seq_puts(m, ",shortname=unknown");
  690. break;
  691. }
  692. }
  693. if (opts->name_check != 'n')
  694. seq_printf(m, ",check=%c", opts->name_check);
  695. if (opts->usefree)
  696. seq_puts(m, ",usefree");
  697. if (opts->quiet)
  698. seq_puts(m, ",quiet");
  699. if (opts->showexec)
  700. seq_puts(m, ",showexec");
  701. if (opts->sys_immutable)
  702. seq_puts(m, ",sys_immutable");
  703. if (!isvfat) {
  704. if (opts->dotsOK)
  705. seq_puts(m, ",dotsOK=yes");
  706. if (opts->nocase)
  707. seq_puts(m, ",nocase");
  708. } else {
  709. if (opts->utf8)
  710. seq_puts(m, ",utf8");
  711. if (opts->unicode_xlate)
  712. seq_puts(m, ",uni_xlate");
  713. if (!opts->numtail)
  714. seq_puts(m, ",nonumtail");
  715. if (opts->rodir)
  716. seq_puts(m, ",rodir");
  717. }
  718. if (opts->flush)
  719. seq_puts(m, ",flush");
  720. if (opts->tz_set) {
  721. if (opts->time_offset)
  722. seq_printf(m, ",time_offset=%d", opts->time_offset);
  723. else
  724. seq_puts(m, ",tz=UTC");
  725. }
  726. if (opts->errors == FAT_ERRORS_CONT)
  727. seq_puts(m, ",errors=continue");
  728. else if (opts->errors == FAT_ERRORS_PANIC)
  729. seq_puts(m, ",errors=panic");
  730. else
  731. seq_puts(m, ",errors=remount-ro");
  732. if (opts->nfs == FAT_NFS_NOSTALE_RO)
  733. seq_puts(m, ",nfs=nostale_ro");
  734. else if (opts->nfs)
  735. seq_puts(m, ",nfs=stale_rw");
  736. if (opts->discard)
  737. seq_puts(m, ",discard");
  738. return 0;
  739. }
  740. enum {
  741. Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
  742. Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
  743. Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
  744. Opt_immutable, Opt_dots, Opt_nodots,
  745. Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
  746. Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
  747. Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
  748. Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
  749. Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
  750. Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err,
  751. };
  752. static const match_table_t fat_tokens = {
  753. {Opt_check_r, "check=relaxed"},
  754. {Opt_check_s, "check=strict"},
  755. {Opt_check_n, "check=normal"},
  756. {Opt_check_r, "check=r"},
  757. {Opt_check_s, "check=s"},
  758. {Opt_check_n, "check=n"},
  759. {Opt_uid, "uid=%u"},
  760. {Opt_gid, "gid=%u"},
  761. {Opt_umask, "umask=%o"},
  762. {Opt_dmask, "dmask=%o"},
  763. {Opt_fmask, "fmask=%o"},
  764. {Opt_allow_utime, "allow_utime=%o"},
  765. {Opt_codepage, "codepage=%u"},
  766. {Opt_usefree, "usefree"},
  767. {Opt_nocase, "nocase"},
  768. {Opt_quiet, "quiet"},
  769. {Opt_showexec, "showexec"},
  770. {Opt_debug, "debug"},
  771. {Opt_immutable, "sys_immutable"},
  772. {Opt_flush, "flush"},
  773. {Opt_tz_utc, "tz=UTC"},
  774. {Opt_time_offset, "time_offset=%d"},
  775. {Opt_err_cont, "errors=continue"},
  776. {Opt_err_panic, "errors=panic"},
  777. {Opt_err_ro, "errors=remount-ro"},
  778. {Opt_discard, "discard"},
  779. {Opt_nfs_stale_rw, "nfs"},
  780. {Opt_nfs_stale_rw, "nfs=stale_rw"},
  781. {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
  782. {Opt_obsolete, "conv=binary"},
  783. {Opt_obsolete, "conv=text"},
  784. {Opt_obsolete, "conv=auto"},
  785. {Opt_obsolete, "conv=b"},
  786. {Opt_obsolete, "conv=t"},
  787. {Opt_obsolete, "conv=a"},
  788. {Opt_obsolete, "fat=%u"},
  789. {Opt_obsolete, "blocksize=%u"},
  790. {Opt_obsolete, "cvf_format=%20s"},
  791. {Opt_obsolete, "cvf_options=%100s"},
  792. {Opt_obsolete, "posix"},
  793. {Opt_err, NULL},
  794. };
  795. static const match_table_t msdos_tokens = {
  796. {Opt_nodots, "nodots"},
  797. {Opt_nodots, "dotsOK=no"},
  798. {Opt_dots, "dots"},
  799. {Opt_dots, "dotsOK=yes"},
  800. {Opt_err, NULL}
  801. };
  802. static const match_table_t vfat_tokens = {
  803. {Opt_charset, "iocharset=%s"},
  804. {Opt_shortname_lower, "shortname=lower"},
  805. {Opt_shortname_win95, "shortname=win95"},
  806. {Opt_shortname_winnt, "shortname=winnt"},
  807. {Opt_shortname_mixed, "shortname=mixed"},
  808. {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
  809. {Opt_utf8_no, "utf8=no"},
  810. {Opt_utf8_no, "utf8=false"},
  811. {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
  812. {Opt_utf8_yes, "utf8=yes"},
  813. {Opt_utf8_yes, "utf8=true"},
  814. {Opt_utf8_yes, "utf8"},
  815. {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
  816. {Opt_uni_xl_no, "uni_xlate=no"},
  817. {Opt_uni_xl_no, "uni_xlate=false"},
  818. {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
  819. {Opt_uni_xl_yes, "uni_xlate=yes"},
  820. {Opt_uni_xl_yes, "uni_xlate=true"},
  821. {Opt_uni_xl_yes, "uni_xlate"},
  822. {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
  823. {Opt_nonumtail_no, "nonumtail=no"},
  824. {Opt_nonumtail_no, "nonumtail=false"},
  825. {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
  826. {Opt_nonumtail_yes, "nonumtail=yes"},
  827. {Opt_nonumtail_yes, "nonumtail=true"},
  828. {Opt_nonumtail_yes, "nonumtail"},
  829. {Opt_rodir, "rodir"},
  830. {Opt_err, NULL}
  831. };
  832. static int parse_options(struct super_block *sb, char *options, int is_vfat,
  833. int silent, int *debug, struct fat_mount_options *opts)
  834. {
  835. char *p;
  836. substring_t args[MAX_OPT_ARGS];
  837. int option;
  838. char *iocharset;
  839. opts->isvfat = is_vfat;
  840. opts->fs_uid = current_uid();
  841. opts->fs_gid = current_gid();
  842. opts->fs_fmask = opts->fs_dmask = current_umask();
  843. opts->allow_utime = -1;
  844. opts->codepage = fat_default_codepage;
  845. opts->iocharset = fat_default_iocharset;
  846. if (is_vfat) {
  847. opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
  848. opts->rodir = 0;
  849. } else {
  850. opts->shortname = 0;
  851. opts->rodir = 1;
  852. }
  853. opts->name_check = 'n';
  854. opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
  855. opts->utf8 = opts->unicode_xlate = 0;
  856. opts->numtail = 1;
  857. opts->usefree = opts->nocase = 0;
  858. opts->tz_set = 0;
  859. opts->nfs = 0;
  860. opts->errors = FAT_ERRORS_RO;
  861. *debug = 0;
  862. if (!options)
  863. goto out;
  864. while ((p = strsep(&options, ",")) != NULL) {
  865. int token;
  866. if (!*p)
  867. continue;
  868. token = match_token(p, fat_tokens, args);
  869. if (token == Opt_err) {
  870. if (is_vfat)
  871. token = match_token(p, vfat_tokens, args);
  872. else
  873. token = match_token(p, msdos_tokens, args);
  874. }
  875. switch (token) {
  876. case Opt_check_s:
  877. opts->name_check = 's';
  878. break;
  879. case Opt_check_r:
  880. opts->name_check = 'r';
  881. break;
  882. case Opt_check_n:
  883. opts->name_check = 'n';
  884. break;
  885. case Opt_usefree:
  886. opts->usefree = 1;
  887. break;
  888. case Opt_nocase:
  889. if (!is_vfat)
  890. opts->nocase = 1;
  891. else {
  892. /* for backward compatibility */
  893. opts->shortname = VFAT_SFN_DISPLAY_WIN95
  894. | VFAT_SFN_CREATE_WIN95;
  895. }
  896. break;
  897. case Opt_quiet:
  898. opts->quiet = 1;
  899. break;
  900. case Opt_showexec:
  901. opts->showexec = 1;
  902. break;
  903. case Opt_debug:
  904. *debug = 1;
  905. break;
  906. case Opt_immutable:
  907. opts->sys_immutable = 1;
  908. break;
  909. case Opt_uid:
  910. if (match_int(&args[0], &option))
  911. return -EINVAL;
  912. opts->fs_uid = make_kuid(current_user_ns(), option);
  913. if (!uid_valid(opts->fs_uid))
  914. return -EINVAL;
  915. break;
  916. case Opt_gid:
  917. if (match_int(&args[0], &option))
  918. return -EINVAL;
  919. opts->fs_gid = make_kgid(current_user_ns(), option);
  920. if (!gid_valid(opts->fs_gid))
  921. return -EINVAL;
  922. break;
  923. case Opt_umask:
  924. if (match_octal(&args[0], &option))
  925. return -EINVAL;
  926. opts->fs_fmask = opts->fs_dmask = option;
  927. break;
  928. case Opt_dmask:
  929. if (match_octal(&args[0], &option))
  930. return -EINVAL;
  931. opts->fs_dmask = option;
  932. break;
  933. case Opt_fmask:
  934. if (match_octal(&args[0], &option))
  935. return -EINVAL;
  936. opts->fs_fmask = option;
  937. break;
  938. case Opt_allow_utime:
  939. if (match_octal(&args[0], &option))
  940. return -EINVAL;
  941. opts->allow_utime = option & (S_IWGRP | S_IWOTH);
  942. break;
  943. case Opt_codepage:
  944. if (match_int(&args[0], &option))
  945. return -EINVAL;
  946. opts->codepage = option;
  947. break;
  948. case Opt_flush:
  949. opts->flush = 1;
  950. break;
  951. case Opt_time_offset:
  952. if (match_int(&args[0], &option))
  953. return -EINVAL;
  954. if (option < -12 * 60 || option > 12 * 60)
  955. return -EINVAL;
  956. opts->tz_set = 1;
  957. opts->time_offset = option;
  958. break;
  959. case Opt_tz_utc:
  960. opts->tz_set = 1;
  961. opts->time_offset = 0;
  962. break;
  963. case Opt_err_cont:
  964. opts->errors = FAT_ERRORS_CONT;
  965. break;
  966. case Opt_err_panic:
  967. opts->errors = FAT_ERRORS_PANIC;
  968. break;
  969. case Opt_err_ro:
  970. opts->errors = FAT_ERRORS_RO;
  971. break;
  972. case Opt_nfs_stale_rw:
  973. opts->nfs = FAT_NFS_STALE_RW;
  974. break;
  975. case Opt_nfs_nostale_ro:
  976. opts->nfs = FAT_NFS_NOSTALE_RO;
  977. break;
  978. /* msdos specific */
  979. case Opt_dots:
  980. opts->dotsOK = 1;
  981. break;
  982. case Opt_nodots:
  983. opts->dotsOK = 0;
  984. break;
  985. /* vfat specific */
  986. case Opt_charset:
  987. if (opts->iocharset != fat_default_iocharset)
  988. kfree(opts->iocharset);
  989. iocharset = match_strdup(&args[0]);
  990. if (!iocharset)
  991. return -ENOMEM;
  992. opts->iocharset = iocharset;
  993. break;
  994. case Opt_shortname_lower:
  995. opts->shortname = VFAT_SFN_DISPLAY_LOWER
  996. | VFAT_SFN_CREATE_WIN95;
  997. break;
  998. case Opt_shortname_win95:
  999. opts->shortname = VFAT_SFN_DISPLAY_WIN95
  1000. | VFAT_SFN_CREATE_WIN95;
  1001. break;
  1002. case Opt_shortname_winnt:
  1003. opts->shortname = VFAT_SFN_DISPLAY_WINNT
  1004. | VFAT_SFN_CREATE_WINNT;
  1005. break;
  1006. case Opt_shortname_mixed:
  1007. opts->shortname = VFAT_SFN_DISPLAY_WINNT
  1008. | VFAT_SFN_CREATE_WIN95;
  1009. break;
  1010. case Opt_utf8_no: /* 0 or no or false */
  1011. opts->utf8 = 0;
  1012. break;
  1013. case Opt_utf8_yes: /* empty or 1 or yes or true */
  1014. opts->utf8 = 1;
  1015. break;
  1016. case Opt_uni_xl_no: /* 0 or no or false */
  1017. opts->unicode_xlate = 0;
  1018. break;
  1019. case Opt_uni_xl_yes: /* empty or 1 or yes or true */
  1020. opts->unicode_xlate = 1;
  1021. break;
  1022. case Opt_nonumtail_no: /* 0 or no or false */
  1023. opts->numtail = 1; /* negated option */
  1024. break;
  1025. case Opt_nonumtail_yes: /* empty or 1 or yes or true */
  1026. opts->numtail = 0; /* negated option */
  1027. break;
  1028. case Opt_rodir:
  1029. opts->rodir = 1;
  1030. break;
  1031. case Opt_discard:
  1032. opts->discard = 1;
  1033. break;
  1034. /* obsolete mount options */
  1035. case Opt_obsolete:
  1036. fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
  1037. "not supported now", p);
  1038. break;
  1039. /* unknown option */
  1040. default:
  1041. if (!silent) {
  1042. fat_msg(sb, KERN_ERR,
  1043. "Unrecognized mount option \"%s\" "
  1044. "or missing value", p);
  1045. }
  1046. return -EINVAL;
  1047. }
  1048. }
  1049. out:
  1050. /* UTF-8 doesn't provide FAT semantics */
  1051. if (!strcmp(opts->iocharset, "utf8")) {
  1052. fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
  1053. " for FAT filesystems, filesystem will be "
  1054. "case sensitive!");
  1055. }
  1056. /* If user doesn't specify allow_utime, it's initialized from dmask. */
  1057. if (opts->allow_utime == (unsigned short)-1)
  1058. opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
  1059. if (opts->unicode_xlate)
  1060. opts->utf8 = 0;
  1061. if (opts->nfs == FAT_NFS_NOSTALE_RO) {
  1062. sb->s_flags |= MS_RDONLY;
  1063. sb->s_export_op = &fat_export_ops_nostale;
  1064. }
  1065. return 0;
  1066. }
  1067. static int fat_read_root(struct inode *inode)
  1068. {
  1069. struct super_block *sb = inode->i_sb;
  1070. struct msdos_sb_info *sbi = MSDOS_SB(sb);
  1071. int error;
  1072. MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
  1073. inode->i_uid = sbi->options.fs_uid;
  1074. inode->i_gid = sbi->options.fs_gid;
  1075. inode->i_version++;
  1076. inode->i_generation = 0;
  1077. inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
  1078. inode->i_op = sbi->dir_ops;
  1079. inode->i_fop = &fat_dir_operations;
  1080. if (sbi->fat_bits == 32) {
  1081. MSDOS_I(inode)->i_start = sbi->root_cluster;
  1082. error = fat_calc_dir_size(inode);
  1083. if (error < 0)
  1084. return error;
  1085. } else {
  1086. MSDOS_I(inode)->i_start = 0;
  1087. inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
  1088. }
  1089. inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
  1090. & ~((loff_t)sbi->cluster_size - 1)) >> 9;
  1091. MSDOS_I(inode)->i_logstart = 0;
  1092. MSDOS_I(inode)->mmu_private = inode->i_size;
  1093. fat_save_attrs(inode, ATTR_DIR);
  1094. inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
  1095. inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
  1096. set_nlink(inode, fat_subdirs(inode)+2);
  1097. return 0;
  1098. }
  1099. /*
  1100. * Read the super block of an MS-DOS FS.
  1101. */
  1102. int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
  1103. void (*setup)(struct super_block *))
  1104. {
  1105. struct inode *root_inode = NULL, *fat_inode = NULL;
  1106. struct inode *fsinfo_inode = NULL;
  1107. struct buffer_head *bh;
  1108. struct fat_boot_sector *b;
  1109. struct msdos_sb_info *sbi;
  1110. u16 logical_sector_size;
  1111. u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
  1112. int debug;
  1113. unsigned int media;
  1114. long error;
  1115. char buf[50];
  1116. /*
  1117. * GFP_KERNEL is ok here, because while we do hold the
  1118. * supeblock lock, memory pressure can't call back into
  1119. * the filesystem, since we're only just about to mount
  1120. * it and have no inodes etc active!
  1121. */
  1122. sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
  1123. if (!sbi)
  1124. return -ENOMEM;
  1125. sb->s_fs_info = sbi;
  1126. sb->s_flags |= MS_NODIRATIME;
  1127. sb->s_magic = MSDOS_SUPER_MAGIC;
  1128. sb->s_op = &fat_sops;
  1129. sb->s_export_op = &fat_export_ops;
  1130. mutex_init(&sbi->nfs_build_inode_lock);
  1131. ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
  1132. DEFAULT_RATELIMIT_BURST);
  1133. error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
  1134. if (error)
  1135. goto out_fail;
  1136. setup(sb); /* flavour-specific stuff that needs options */
  1137. error = -EIO;
  1138. sb_min_blocksize(sb, 512);
  1139. bh = sb_bread(sb, 0);
  1140. if (bh == NULL) {
  1141. fat_msg(sb, KERN_ERR, "unable to read boot sector");
  1142. goto out_fail;
  1143. }
  1144. b = (struct fat_boot_sector *) bh->b_data;
  1145. if (!b->reserved) {
  1146. if (!silent)
  1147. fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
  1148. brelse(bh);
  1149. goto out_invalid;
  1150. }
  1151. if (!b->fats) {
  1152. if (!silent)
  1153. fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
  1154. brelse(bh);
  1155. goto out_invalid;
  1156. }
  1157. /*
  1158. * Earlier we checked here that b->secs_track and b->head are nonzero,
  1159. * but it turns out valid FAT filesystems can have zero there.
  1160. */
  1161. media = b->media;
  1162. if (!fat_valid_media(media)) {
  1163. if (!silent)
  1164. fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
  1165. media);
  1166. brelse(bh);
  1167. goto out_invalid;
  1168. }
  1169. logical_sector_size = get_unaligned_le16(&b->sector_size);
  1170. if (!is_power_of_2(logical_sector_size)
  1171. || (logical_sector_size < 512)
  1172. || (logical_sector_size > 4096)) {
  1173. if (!silent)
  1174. fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
  1175. logical_sector_size);
  1176. brelse(bh);
  1177. goto out_invalid;
  1178. }
  1179. sbi->sec_per_clus = b->sec_per_clus;
  1180. if (!is_power_of_2(sbi->sec_per_clus)) {
  1181. if (!silent)
  1182. fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
  1183. sbi->sec_per_clus);
  1184. brelse(bh);
  1185. goto out_invalid;
  1186. }
  1187. if (logical_sector_size < sb->s_blocksize) {
  1188. fat_msg(sb, KERN_ERR, "logical sector size too small for device"
  1189. " (logical sector size = %u)", logical_sector_size);
  1190. brelse(bh);
  1191. goto out_fail;
  1192. }
  1193. if (logical_sector_size > sb->s_blocksize) {
  1194. brelse(bh);
  1195. if (!sb_set_blocksize(sb, logical_sector_size)) {
  1196. fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
  1197. logical_sector_size);
  1198. goto out_fail;
  1199. }
  1200. bh = sb_bread(sb, 0);
  1201. if (bh == NULL) {
  1202. fat_msg(sb, KERN_ERR, "unable to read boot sector"
  1203. " (logical sector size = %lu)",
  1204. sb->s_blocksize);
  1205. goto out_fail;
  1206. }
  1207. b = (struct fat_boot_sector *) bh->b_data;
  1208. }
  1209. mutex_init(&sbi->s_lock);
  1210. sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
  1211. sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
  1212. sbi->fats = b->fats;
  1213. sbi->fat_bits = 0; /* Don't know yet */
  1214. sbi->fat_start = le16_to_cpu(b->reserved);
  1215. sbi->fat_length = le16_to_cpu(b->fat_length);
  1216. sbi->root_cluster = 0;
  1217. sbi->free_clusters = -1; /* Don't know yet */
  1218. sbi->free_clus_valid = 0;
  1219. sbi->prev_free = FAT_START_ENT;
  1220. sb->s_maxbytes = 0xffffffff;
  1221. if (!sbi->fat_length && b->fat32.length) {
  1222. struct fat_boot_fsinfo *fsinfo;
  1223. struct buffer_head *fsinfo_bh;
  1224. /* Must be FAT32 */
  1225. sbi->fat_bits = 32;
  1226. sbi->fat_length = le32_to_cpu(b->fat32.length);
  1227. sbi->root_cluster = le32_to_cpu(b->fat32.root_cluster);
  1228. /* MC - if info_sector is 0, don't multiply by 0 */
  1229. sbi->fsinfo_sector = le16_to_cpu(b->fat32.info_sector);
  1230. if (sbi->fsinfo_sector == 0)
  1231. sbi->fsinfo_sector = 1;
  1232. fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
  1233. if (fsinfo_bh == NULL) {
  1234. fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
  1235. " (sector = %lu)", sbi->fsinfo_sector);
  1236. brelse(bh);
  1237. goto out_fail;
  1238. }
  1239. fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
  1240. if (!IS_FSINFO(fsinfo)) {
  1241. fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
  1242. "0x%08x, 0x%08x (sector = %lu)",
  1243. le32_to_cpu(fsinfo->signature1),
  1244. le32_to_cpu(fsinfo->signature2),
  1245. sbi->fsinfo_sector);
  1246. } else {
  1247. if (sbi->options.usefree)
  1248. sbi->free_clus_valid = 1;
  1249. sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
  1250. sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
  1251. }
  1252. brelse(fsinfo_bh);
  1253. }
  1254. sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
  1255. sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
  1256. sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
  1257. sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
  1258. if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
  1259. if (!silent)
  1260. fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
  1261. " (%u)", sbi->dir_entries);
  1262. brelse(bh);
  1263. goto out_invalid;
  1264. }
  1265. rootdir_sectors = sbi->dir_entries
  1266. * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
  1267. sbi->data_start = sbi->dir_start + rootdir_sectors;
  1268. total_sectors = get_unaligned_le16(&b->sectors);
  1269. if (total_sectors == 0)
  1270. total_sectors = le32_to_cpu(b->total_sect);
  1271. total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
  1272. if (sbi->fat_bits != 32)
  1273. sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
  1274. /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
  1275. if (sbi->fat_bits == 32)
  1276. sbi->dirty = b->fat32.state & FAT_STATE_DIRTY;
  1277. else /* fat 16 or 12 */
  1278. sbi->dirty = b->fat16.state & FAT_STATE_DIRTY;
  1279. /* check that FAT table does not overflow */
  1280. fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
  1281. total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
  1282. if (total_clusters > MAX_FAT(sb)) {
  1283. if (!silent)
  1284. fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
  1285. total_clusters);
  1286. brelse(bh);
  1287. goto out_invalid;
  1288. }
  1289. sbi->max_cluster = total_clusters + FAT_START_ENT;
  1290. /* check the free_clusters, it's not necessarily correct */
  1291. if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
  1292. sbi->free_clusters = -1;
  1293. /* check the prev_free, it's not necessarily correct */
  1294. sbi->prev_free %= sbi->max_cluster;
  1295. if (sbi->prev_free < FAT_START_ENT)
  1296. sbi->prev_free = FAT_START_ENT;
  1297. brelse(bh);
  1298. /* set up enough so that it can read an inode */
  1299. fat_hash_init(sb);
  1300. dir_hash_init(sb);
  1301. fat_ent_access_init(sb);
  1302. /*
  1303. * The low byte of FAT's first entry must have same value with
  1304. * media-field. But in real world, too many devices is
  1305. * writing wrong value. So, removed that validity check.
  1306. *
  1307. * if (FAT_FIRST_ENT(sb, media) != first)
  1308. */
  1309. error = -EINVAL;
  1310. sprintf(buf, "cp%d", sbi->options.codepage);
  1311. sbi->nls_disk = load_nls(buf);
  1312. if (!sbi->nls_disk) {
  1313. fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
  1314. goto out_fail;
  1315. }
  1316. /* FIXME: utf8 is using iocharset for upper/lower conversion */
  1317. if (sbi->options.isvfat) {
  1318. sbi->nls_io = load_nls(sbi->options.iocharset);
  1319. if (!sbi->nls_io) {
  1320. fat_msg(sb, KERN_ERR, "IO charset %s not found",
  1321. sbi->options.iocharset);
  1322. goto out_fail;
  1323. }
  1324. }
  1325. error = -ENOMEM;
  1326. fat_inode = new_inode(sb);
  1327. if (!fat_inode)
  1328. goto out_fail;
  1329. MSDOS_I(fat_inode)->i_pos = 0;
  1330. sbi->fat_inode = fat_inode;
  1331. fsinfo_inode = new_inode(sb);
  1332. if (!fsinfo_inode)
  1333. goto out_fail;
  1334. fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
  1335. sbi->fsinfo_inode = fsinfo_inode;
  1336. insert_inode_hash(fsinfo_inode);
  1337. root_inode = new_inode(sb);
  1338. if (!root_inode)
  1339. goto out_fail;
  1340. root_inode->i_ino = MSDOS_ROOT_INO;
  1341. root_inode->i_version = 1;
  1342. error = fat_read_root(root_inode);
  1343. if (error < 0) {
  1344. iput(root_inode);
  1345. goto out_fail;
  1346. }
  1347. error = -ENOMEM;
  1348. insert_inode_hash(root_inode);
  1349. fat_attach(root_inode, 0);
  1350. sb->s_root = d_make_root(root_inode);
  1351. if (!sb->s_root) {
  1352. fat_msg(sb, KERN_ERR, "get root inode failed");
  1353. goto out_fail;
  1354. }
  1355. if (sbi->options.discard) {
  1356. struct request_queue *q = bdev_get_queue(sb->s_bdev);
  1357. if (!blk_queue_discard(q))
  1358. fat_msg(sb, KERN_WARNING,
  1359. "mounting with \"discard\" option, but "
  1360. "the device does not support discard");
  1361. }
  1362. fat_set_state(sb, 1, 0);
  1363. return 0;
  1364. out_invalid:
  1365. error = -EINVAL;
  1366. if (!silent)
  1367. fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
  1368. out_fail:
  1369. if (fsinfo_inode)
  1370. iput(fsinfo_inode);
  1371. if (fat_inode)
  1372. iput(fat_inode);
  1373. unload_nls(sbi->nls_io);
  1374. unload_nls(sbi->nls_disk);
  1375. if (sbi->options.iocharset != fat_default_iocharset)
  1376. kfree(sbi->options.iocharset);
  1377. sb->s_fs_info = NULL;
  1378. kfree(sbi);
  1379. return error;
  1380. }
  1381. EXPORT_SYMBOL_GPL(fat_fill_super);
  1382. /*
  1383. * helper function for fat_flush_inodes. This writes both the inode
  1384. * and the file data blocks, waiting for in flight data blocks before
  1385. * the start of the call. It does not wait for any io started
  1386. * during the call
  1387. */
  1388. static int writeback_inode(struct inode *inode)
  1389. {
  1390. int ret;
  1391. /* if we used wait=1, sync_inode_metadata waits for the io for the
  1392. * inode to finish. So wait=0 is sent down to sync_inode_metadata
  1393. * and filemap_fdatawrite is used for the data blocks
  1394. */
  1395. ret = sync_inode_metadata(inode, 0);
  1396. if (!ret)
  1397. ret = filemap_fdatawrite(inode->i_mapping);
  1398. return ret;
  1399. }
  1400. /*
  1401. * write data and metadata corresponding to i1 and i2. The io is
  1402. * started but we do not wait for any of it to finish.
  1403. *
  1404. * filemap_flush is used for the block device, so if there is a dirty
  1405. * page for a block already in flight, we will not wait and start the
  1406. * io over again
  1407. */
  1408. int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
  1409. {
  1410. int ret = 0;
  1411. if (!MSDOS_SB(sb)->options.flush)
  1412. return 0;
  1413. if (i1)
  1414. ret = writeback_inode(i1);
  1415. if (!ret && i2)
  1416. ret = writeback_inode(i2);
  1417. if (!ret) {
  1418. struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
  1419. ret = filemap_flush(mapping);
  1420. }
  1421. return ret;
  1422. }
  1423. EXPORT_SYMBOL_GPL(fat_flush_inodes);
  1424. static int __init init_fat_fs(void)
  1425. {
  1426. int err;
  1427. err = fat_cache_init();
  1428. if (err)
  1429. return err;
  1430. err = fat_init_inodecache();
  1431. if (err)
  1432. goto failed;
  1433. return 0;
  1434. failed:
  1435. fat_cache_destroy();
  1436. return err;
  1437. }
  1438. static void __exit exit_fat_fs(void)
  1439. {
  1440. fat_cache_destroy();
  1441. fat_destroy_inodecache();
  1442. }
  1443. module_init(init_fat_fs)
  1444. module_exit(exit_fat_fs)
  1445. MODULE_LICENSE("GPL");