fat.h 13 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392
  1. #ifndef _FAT_H
  2. #define _FAT_H
  3. #include <linux/buffer_head.h>
  4. #include <linux/string.h>
  5. #include <linux/nls.h>
  6. #include <linux/fs.h>
  7. #include <linux/mutex.h>
  8. #include <linux/ratelimit.h>
  9. #include <linux/msdos_fs.h>
  10. #ifdef CONFIG_FAT_SUPPORT_STLOG
  11. #include <linux/stlog.h>
  12. #else
  13. #define ST_LOG(fmt,...)
  14. #endif
  15. /*
  16. * vfat shortname flags
  17. */
  18. #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
  19. #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
  20. #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
  21. #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
  22. #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
  23. #define FAT_ERRORS_CONT 1 /* ignore error and continue */
  24. #define FAT_ERRORS_PANIC 2 /* panic on error */
  25. #define FAT_ERRORS_RO 3 /* remount r/o on error */
  26. struct fat_mount_options {
  27. uid_t fs_uid;
  28. gid_t fs_gid;
  29. unsigned short fs_fmask;
  30. unsigned short fs_dmask;
  31. unsigned short codepage; /* Codepage for shortname conversions */
  32. char *iocharset; /* Charset used for filename input/display */
  33. unsigned short shortname; /* flags for shortname display/create rule */
  34. unsigned char name_check; /* r = relaxed, n = normal, s = strict */
  35. unsigned char errors; /* On error: continue, panic, remount-ro */
  36. unsigned short allow_utime;/* permission for setting the [am]time */
  37. unsigned quiet:1, /* set = fake successful chmods and chowns */
  38. showexec:1, /* set = only set x bit for com/exe/bat */
  39. sys_immutable:1, /* set = system files are immutable */
  40. dotsOK:1, /* set = hidden and system files are named '.filename' */
  41. isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
  42. utf8:1, /* Use of UTF-8 character set (Default) */
  43. unicode_xlate:1, /* create escape sequences for unhandled Unicode */
  44. numtail:1, /* Does first alias have a numeric '~1' type tail? */
  45. flush:1, /* write things quickly */
  46. nocase:1, /* Does this need case conversion? 0=need case conversion*/
  47. usefree:1, /* Use free_clusters for FAT32 */
  48. tz_utc:1, /* Filesystem timestamps are in UTC */
  49. rodir:1, /* allow ATTR_RO for directory */
  50. discard:1; /* Issue discard requests on deletions */
  51. };
  52. #define FAT_HASH_BITS 8
  53. #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
  54. /*
  55. * MS-DOS file system in-core superblock data
  56. */
  57. struct msdos_sb_info {
  58. unsigned short sec_per_clus; /* sectors/cluster */
  59. unsigned short cluster_bits; /* log2(cluster_size) */
  60. unsigned int cluster_size; /* cluster size */
  61. unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
  62. unsigned short fat_start;
  63. unsigned long fat_length; /* FAT start & length (sec.) */
  64. unsigned long dir_start;
  65. unsigned short dir_entries; /* root dir start & entries */
  66. unsigned long data_start; /* first data sector */
  67. unsigned long max_cluster; /* maximum cluster number */
  68. unsigned long root_cluster; /* first cluster of the root directory */
  69. unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
  70. struct mutex fat_lock;
  71. unsigned int prev_free; /* previously allocated cluster number */
  72. unsigned int free_clusters; /* -1 if undefined */
  73. unsigned int free_clus_valid; /* is free_clusters valid? */
  74. struct fat_mount_options options;
  75. struct nls_table *nls_disk; /* Codepage used on disk */
  76. struct nls_table *nls_io; /* Charset used for input and display */
  77. const void *dir_ops; /* Opaque; default directory operations */
  78. int dir_per_block; /* dir entries per block */
  79. int dir_per_block_bits; /* log2(dir_per_block) */
  80. unsigned long vol_id; /* volume ID */
  81. int fatent_shift;
  82. struct fatent_operations *fatent_ops;
  83. struct inode *fat_inode;
  84. struct inode *fsinfo_inode;
  85. struct ratelimit_state ratelimit;
  86. spinlock_t inode_hash_lock;
  87. struct hlist_head inode_hashtable[FAT_HASH_SIZE];
  88. };
  89. #define FAT_CACHE_VALID 0 /* special case for valid cache */
  90. /*
  91. * MS-DOS file system inode data in memory
  92. */
  93. struct msdos_inode_info {
  94. spinlock_t cache_lru_lock;
  95. struct list_head cache_lru;
  96. int nr_caches;
  97. /* for avoiding the race between fat_free() and fat_get_cluster() */
  98. unsigned int cache_valid_id;
  99. /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
  100. loff_t mmu_private; /* physically allocated size */
  101. int i_start; /* first cluster or 0 */
  102. int i_logstart; /* logical first cluster */
  103. int i_attrs; /* unused attribute bits */
  104. loff_t i_pos; /* on-disk position of directory entry or 0 */
  105. struct hlist_node i_fat_hash; /* hash by i_location */
  106. struct rw_semaphore truncate_lock; /* protect bmap against truncate */
  107. struct inode vfs_inode;
  108. };
  109. struct fat_slot_info {
  110. loff_t i_pos; /* on-disk position of directory entry */
  111. loff_t slot_off; /* offset for slot or de start */
  112. int nr_slots; /* number of slots + 1(de) in filename */
  113. struct msdos_dir_entry *de;
  114. struct buffer_head *bh;
  115. };
  116. static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
  117. {
  118. return sb->s_fs_info;
  119. }
  120. static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
  121. {
  122. return container_of(inode, struct msdos_inode_info, vfs_inode);
  123. }
  124. /*
  125. * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
  126. * save ATTR_RO instead of ->i_mode.
  127. *
  128. * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
  129. * bit, it's just used as flag for app.
  130. */
  131. static inline int fat_mode_can_hold_ro(struct inode *inode)
  132. {
  133. struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
  134. umode_t mask;
  135. if (S_ISDIR(inode->i_mode)) {
  136. if (!sbi->options.rodir)
  137. return 0;
  138. mask = ~sbi->options.fs_dmask;
  139. } else
  140. mask = ~sbi->options.fs_fmask;
  141. if (!(mask & S_IWUGO))
  142. return 0;
  143. return 1;
  144. }
  145. /* Convert attribute bits and a mask to the UNIX mode. */
  146. static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
  147. u8 attrs, umode_t mode)
  148. {
  149. if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
  150. mode &= ~S_IWUGO;
  151. if (attrs & ATTR_DIR)
  152. return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
  153. else
  154. return (mode & ~sbi->options.fs_fmask) | S_IFREG;
  155. }
  156. /* Return the FAT attribute byte for this inode */
  157. static inline u8 fat_make_attrs(struct inode *inode)
  158. {
  159. u8 attrs = MSDOS_I(inode)->i_attrs;
  160. if (S_ISDIR(inode->i_mode))
  161. attrs |= ATTR_DIR;
  162. if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
  163. attrs |= ATTR_RO;
  164. return attrs;
  165. }
  166. static inline void fat_save_attrs(struct inode *inode, u8 attrs)
  167. {
  168. if (fat_mode_can_hold_ro(inode))
  169. MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
  170. else
  171. MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
  172. }
  173. static inline unsigned char fat_checksum(const __u8 *name)
  174. {
  175. unsigned char s = name[0];
  176. s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
  177. s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
  178. s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
  179. s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
  180. s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
  181. return s;
  182. }
  183. static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
  184. {
  185. return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
  186. + sbi->data_start;
  187. }
  188. static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
  189. {
  190. #ifdef __BIG_ENDIAN
  191. while (len--) {
  192. *dst++ = src[0] | (src[1] << 8);
  193. src += 2;
  194. }
  195. #else
  196. memcpy(dst, src, len * 2);
  197. #endif
  198. }
  199. static inline int fat_get_start(const struct msdos_sb_info *sbi,
  200. const struct msdos_dir_entry *de)
  201. {
  202. int cluster = le16_to_cpu(de->start);
  203. if (sbi->fat_bits == 32)
  204. cluster |= (le16_to_cpu(de->starthi) << 16);
  205. return cluster;
  206. }
  207. static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
  208. {
  209. de->start = cpu_to_le16(cluster);
  210. de->starthi = cpu_to_le16(cluster >> 16);
  211. }
  212. static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
  213. {
  214. #ifdef __BIG_ENDIAN
  215. while (len--) {
  216. dst[0] = *src & 0x00FF;
  217. dst[1] = (*src & 0xFF00) >> 8;
  218. dst += 2;
  219. src++;
  220. }
  221. #else
  222. memcpy(dst, src, len * 2);
  223. #endif
  224. }
  225. /* fat/cache.c */
  226. extern void fat_cache_inval_inode(struct inode *inode);
  227. extern int fat_get_cluster(struct inode *inode, int cluster,
  228. int *fclus, int *dclus);
  229. extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
  230. unsigned long *mapped_blocks, int create);
  231. /* fat/dir.c */
  232. extern const struct file_operations fat_dir_operations;
  233. extern int fat_search_long(struct inode *inode, const unsigned char *name,
  234. int name_len, struct fat_slot_info *sinfo);
  235. extern int fat_dir_empty(struct inode *dir);
  236. extern int fat_subdirs(struct inode *dir);
  237. extern int fat_scan(struct inode *dir, const unsigned char *name,
  238. struct fat_slot_info *sinfo);
  239. extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
  240. struct msdos_dir_entry **de, loff_t *i_pos);
  241. extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
  242. extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
  243. struct fat_slot_info *sinfo);
  244. extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
  245. /* fat/fatent.c */
  246. struct fat_entry {
  247. int entry;
  248. union {
  249. u8 *ent12_p[2];
  250. __le16 *ent16_p;
  251. __le32 *ent32_p;
  252. } u;
  253. int nr_bhs;
  254. struct buffer_head *bhs[2];
  255. struct inode *fat_inode;
  256. };
  257. static inline void fatent_init(struct fat_entry *fatent)
  258. {
  259. fatent->nr_bhs = 0;
  260. fatent->entry = 0;
  261. fatent->u.ent32_p = NULL;
  262. fatent->bhs[0] = fatent->bhs[1] = NULL;
  263. fatent->fat_inode = NULL;
  264. }
  265. static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
  266. {
  267. fatent->entry = entry;
  268. fatent->u.ent32_p = NULL;
  269. }
  270. static inline void fatent_brelse(struct fat_entry *fatent)
  271. {
  272. int i;
  273. fatent->u.ent32_p = NULL;
  274. for (i = 0; i < fatent->nr_bhs; i++)
  275. brelse(fatent->bhs[i]);
  276. fatent->nr_bhs = 0;
  277. fatent->bhs[0] = fatent->bhs[1] = NULL;
  278. fatent->fat_inode = NULL;
  279. }
  280. extern void fat_ent_access_init(struct super_block *sb);
  281. extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
  282. int entry);
  283. extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
  284. int new, int wait);
  285. extern int fat_alloc_clusters(struct inode *inode, int *cluster,
  286. int nr_cluster);
  287. extern int fat_free_clusters(struct inode *inode, int cluster);
  288. extern int fat_count_free_clusters(struct super_block *sb);
  289. /* fat/file.c */
  290. extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
  291. unsigned long arg);
  292. extern const struct file_operations fat_file_operations;
  293. extern const struct inode_operations fat_file_inode_operations;
  294. extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
  295. extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
  296. extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
  297. struct kstat *stat);
  298. extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
  299. int datasync);
  300. /* fat/inode.c */
  301. extern void fat_attach(struct inode *inode, loff_t i_pos);
  302. extern void fat_detach(struct inode *inode);
  303. extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
  304. extern struct inode *fat_build_inode(struct super_block *sb,
  305. struct msdos_dir_entry *de, loff_t i_pos);
  306. extern int fat_sync_inode(struct inode *inode);
  307. extern int fat_fill_super(struct super_block *sb, void *data, int silent,
  308. int isvfat, void (*setup)(struct super_block *));
  309. extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
  310. struct inode *i2);
  311. /* fat/misc.c */
  312. extern __printf(3, 4) __cold
  313. void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
  314. #define fat_fs_error_ratelimit(sb, fmt, args...) \
  315. __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
  316. /*
  317. * If removable devices with a fat fs are removed without a unmount, further
  318. * accesses to the device by applications causes a large number of error prints
  319. * & in some cases leads to watchdog bark.
  320. */
  321. #define fat_fs_error(sb, fmt, args...) fat_fs_error_ratelimit(sb, fmt, ## args)
  322. __printf(3, 4) __cold
  323. void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
  324. #define fat_msg_ratelimit(sb, level, fmt, args...) \
  325. do { \
  326. if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
  327. fat_msg(sb, level, fmt, ## args); \
  328. } while (0)
  329. extern int fat_clusters_flush(struct super_block *sb);
  330. extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
  331. extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
  332. __le16 __time, __le16 __date, u8 time_cs);
  333. extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
  334. __le16 *time, __le16 *date, u8 *time_cs);
  335. extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
  336. int fat_cache_init(void);
  337. void fat_cache_destroy(void);
  338. /* fat/xattr.c */
  339. extern int fat_setxattr(struct dentry *dentry, const char *name,
  340. const void *value, size_t size, int flags);
  341. extern ssize_t fat_getxattr(struct dentry *dentry, const char *name,
  342. void *value, size_t size);
  343. extern ssize_t fat_listxattr(struct dentry *dentry, char *list, size_t size);
  344. extern int fat_removexattr(struct dentry *dentry, const char *name);
  345. /* helper for printk */
  346. typedef unsigned long long llu;
  347. #endif /* !_FAT_H */