1 #ifndef _FAT_H 2 #define _FAT_H 3 4 #include <linux/buffer_head.h> 5 #include <linux/nls.h> 6 #include <linux/hash.h> 7 #include <linux/ratelimit.h> 8 #include <linux/msdos_fs.h> 9 10 /* 11 * vfat shortname flags 12 */ 13 #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */ 14 #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */ 15 #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */ 16 #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */ 17 #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */ 18 19 #define FAT_ERRORS_CONT 1 /* ignore error and continue */ 20 #define FAT_ERRORS_PANIC 2 /* panic on error */ 21 #define FAT_ERRORS_RO 3 /* remount r/o on error */ 22 23 #define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */ 24 #define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */ 25 26 struct fat_mount_options { 27 kuid_t fs_uid; 28 kgid_t fs_gid; 29 unsigned short fs_fmask; 30 unsigned short fs_dmask; 31 unsigned short codepage; /* Codepage for shortname conversions */ 32 int time_offset; /* Offset of timestamps from UTC (in minutes) */ 33 char *iocharset; /* Charset used for filename input/display */ 34 unsigned short shortname; /* flags for shortname display/create rule */ 35 unsigned char name_check; /* r = relaxed, n = normal, s = strict */ 36 unsigned char errors; /* On error: continue, panic, remount-ro */ 37 unsigned char nfs; /* NFS support: nostale_ro, stale_rw */ 38 unsigned short allow_utime;/* permission for setting the [am]time */ 39 unsigned quiet:1, /* set = fake successful chmods and chowns */ 40 showexec:1, /* set = only set x bit for com/exe/bat */ 41 sys_immutable:1, /* set = system files are immutable */ 42 dotsOK:1, /* set = hidden and system files are named '.filename' */ 43 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */ 44 utf8:1, /* Use of UTF-8 character set (Default) */ 45 unicode_xlate:1, /* create escape sequences for unhandled Unicode */ 46 numtail:1, /* Does first alias have a numeric '~1' type tail? */ 47 flush:1, /* write things quickly */ 48 nocase:1, /* Does this need case conversion? 0=need case conversion*/ 49 usefree:1, /* Use free_clusters for FAT32 */ 50 tz_set:1, /* Filesystem timestamps' offset set */ 51 rodir:1, /* allow ATTR_RO for directory */ 52 discard:1, /* Issue discard requests on deletions */ 53 dos1xfloppy:1; /* Assume default BPB for DOS 1.x floppies */ 54 }; 55 56 #define FAT_HASH_BITS 8 57 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) 58 59 /* 60 * MS-DOS file system in-core superblock data 61 */ 62 struct msdos_sb_info { 63 unsigned short sec_per_clus; /* sectors/cluster */ 64 unsigned short cluster_bits; /* log2(cluster_size) */ 65 unsigned int cluster_size; /* cluster size */ 66 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */ 67 unsigned short fat_start; 68 unsigned long fat_length; /* FAT start & length (sec.) */ 69 unsigned long dir_start; 70 unsigned short dir_entries; /* root dir start & entries */ 71 unsigned long data_start; /* first data sector */ 72 unsigned long max_cluster; /* maximum cluster number */ 73 unsigned long root_cluster; /* first cluster of the root directory */ 74 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ 75 struct mutex fat_lock; 76 struct mutex nfs_build_inode_lock; 77 struct mutex s_lock; 78 unsigned int prev_free; /* previously allocated cluster number */ 79 unsigned int free_clusters; /* -1 if undefined */ 80 unsigned int free_clus_valid; /* is free_clusters valid? */ 81 struct fat_mount_options options; 82 struct nls_table *nls_disk; /* Codepage used on disk */ 83 struct nls_table *nls_io; /* Charset used for input and display */ 84 const void *dir_ops; /* Opaque; default directory operations */ 85 int dir_per_block; /* dir entries per block */ 86 int dir_per_block_bits; /* log2(dir_per_block) */ 87 unsigned int vol_id; /*volume ID*/ 88 89 int fatent_shift; 90 const struct fatent_operations *fatent_ops; 91 struct inode *fat_inode; 92 struct inode *fsinfo_inode; 93 94 struct ratelimit_state ratelimit; 95 96 spinlock_t inode_hash_lock; 97 struct hlist_head inode_hashtable[FAT_HASH_SIZE]; 98 99 spinlock_t dir_hash_lock; 100 struct hlist_head dir_hashtable[FAT_HASH_SIZE]; 101 102 unsigned int dirty; /* fs state before mount */ 103 struct rcu_head rcu; 104 }; 105 106 #define FAT_CACHE_VALID 0 /* special case for valid cache */ 107 108 /* 109 * MS-DOS file system inode data in memory 110 */ 111 struct msdos_inode_info { 112 spinlock_t cache_lru_lock; 113 struct list_head cache_lru; 114 int nr_caches; 115 /* for avoiding the race between fat_free() and fat_get_cluster() */ 116 unsigned int cache_valid_id; 117 118 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ 119 loff_t mmu_private; /* physically allocated size */ 120 121 int i_start; /* first cluster or 0 */ 122 int i_logstart; /* logical first cluster */ 123 int i_attrs; /* unused attribute bits */ 124 loff_t i_pos; /* on-disk position of directory entry or 0 */ 125 struct hlist_node i_fat_hash; /* hash by i_location */ 126 struct hlist_node i_dir_hash; /* hash by i_logstart */ 127 struct rw_semaphore truncate_lock; /* protect bmap against truncate */ 128 struct inode vfs_inode; 129 }; 130 131 struct fat_slot_info { 132 loff_t i_pos; /* on-disk position of directory entry */ 133 loff_t slot_off; /* offset for slot or de start */ 134 int nr_slots; /* number of slots + 1(de) in filename */ 135 struct msdos_dir_entry *de; 136 struct buffer_head *bh; 137 }; 138 139 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 140 { 141 return sb->s_fs_info; 142 } 143 144 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 145 { 146 return container_of(inode, struct msdos_inode_info, vfs_inode); 147 } 148 149 /* 150 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to 151 * save ATTR_RO instead of ->i_mode. 152 * 153 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only 154 * bit, it's just used as flag for app. 155 */ 156 static inline int fat_mode_can_hold_ro(struct inode *inode) 157 { 158 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 159 umode_t mask; 160 161 if (S_ISDIR(inode->i_mode)) { 162 if (!sbi->options.rodir) 163 return 0; 164 mask = ~sbi->options.fs_dmask; 165 } else 166 mask = ~sbi->options.fs_fmask; 167 168 if (!(mask & S_IWUGO)) 169 return 0; 170 return 1; 171 } 172 173 /* Convert attribute bits and a mask to the UNIX mode. */ 174 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi, 175 u8 attrs, umode_t mode) 176 { 177 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir)) 178 mode &= ~S_IWUGO; 179 180 if (attrs & ATTR_DIR) 181 return (mode & ~sbi->options.fs_dmask) | S_IFDIR; 182 else 183 return (mode & ~sbi->options.fs_fmask) | S_IFREG; 184 } 185 186 /* Return the FAT attribute byte for this inode */ 187 static inline u8 fat_make_attrs(struct inode *inode) 188 { 189 u8 attrs = MSDOS_I(inode)->i_attrs; 190 if (S_ISDIR(inode->i_mode)) 191 attrs |= ATTR_DIR; 192 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) 193 attrs |= ATTR_RO; 194 return attrs; 195 } 196 197 static inline void fat_save_attrs(struct inode *inode, u8 attrs) 198 { 199 if (fat_mode_can_hold_ro(inode)) 200 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; 201 else 202 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); 203 } 204 205 static inline unsigned char fat_checksum(const __u8 *name) 206 { 207 unsigned char s = name[0]; 208 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; 209 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; 210 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; 211 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; 212 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; 213 return s; 214 } 215 216 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) 217 { 218 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus 219 + sbi->data_start; 220 } 221 222 static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi, 223 loff_t i_pos, sector_t *blknr, int *offset) 224 { 225 *blknr = i_pos >> sbi->dir_per_block_bits; 226 *offset = i_pos & (sbi->dir_per_block - 1); 227 } 228 229 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, 230 struct inode *inode) 231 { 232 loff_t i_pos; 233 #if BITS_PER_LONG == 32 234 spin_lock(&sbi->inode_hash_lock); 235 #endif 236 i_pos = MSDOS_I(inode)->i_pos; 237 #if BITS_PER_LONG == 32 238 spin_unlock(&sbi->inode_hash_lock); 239 #endif 240 return i_pos; 241 } 242 243 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) 244 { 245 #ifdef __BIG_ENDIAN 246 while (len--) { 247 *dst++ = src[0] | (src[1] << 8); 248 src += 2; 249 } 250 #else 251 memcpy(dst, src, len * 2); 252 #endif 253 } 254 255 static inline int fat_get_start(const struct msdos_sb_info *sbi, 256 const struct msdos_dir_entry *de) 257 { 258 int cluster = le16_to_cpu(de->start); 259 if (sbi->fat_bits == 32) 260 cluster |= (le16_to_cpu(de->starthi) << 16); 261 return cluster; 262 } 263 264 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster) 265 { 266 de->start = cpu_to_le16(cluster); 267 de->starthi = cpu_to_le16(cluster >> 16); 268 } 269 270 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) 271 { 272 #ifdef __BIG_ENDIAN 273 while (len--) { 274 dst[0] = *src & 0x00FF; 275 dst[1] = (*src & 0xFF00) >> 8; 276 dst += 2; 277 src++; 278 } 279 #else 280 memcpy(dst, src, len * 2); 281 #endif 282 } 283 284 /* fat/cache.c */ 285 extern void fat_cache_inval_inode(struct inode *inode); 286 extern int fat_get_cluster(struct inode *inode, int cluster, 287 int *fclus, int *dclus); 288 extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector, 289 sector_t last_block, 290 unsigned long *mapped_blocks, sector_t *bmap); 291 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 292 unsigned long *mapped_blocks, int create, bool from_bmap); 293 294 /* fat/dir.c */ 295 extern const struct file_operations fat_dir_operations; 296 extern int fat_search_long(struct inode *inode, const unsigned char *name, 297 int name_len, struct fat_slot_info *sinfo); 298 extern int fat_dir_empty(struct inode *dir); 299 extern int fat_subdirs(struct inode *dir); 300 extern int fat_scan(struct inode *dir, const unsigned char *name, 301 struct fat_slot_info *sinfo); 302 extern int fat_scan_logstart(struct inode *dir, int i_logstart, 303 struct fat_slot_info *sinfo); 304 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 305 struct msdos_dir_entry **de); 306 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 307 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 308 struct fat_slot_info *sinfo); 309 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 310 311 /* fat/fatent.c */ 312 struct fat_entry { 313 int entry; 314 union { 315 u8 *ent12_p[2]; 316 __le16 *ent16_p; 317 __le32 *ent32_p; 318 } u; 319 int nr_bhs; 320 struct buffer_head *bhs[2]; 321 struct inode *fat_inode; 322 }; 323 324 static inline void fatent_init(struct fat_entry *fatent) 325 { 326 fatent->nr_bhs = 0; 327 fatent->entry = 0; 328 fatent->u.ent32_p = NULL; 329 fatent->bhs[0] = fatent->bhs[1] = NULL; 330 fatent->fat_inode = NULL; 331 } 332 333 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 334 { 335 fatent->entry = entry; 336 fatent->u.ent32_p = NULL; 337 } 338 339 static inline void fatent_brelse(struct fat_entry *fatent) 340 { 341 int i; 342 fatent->u.ent32_p = NULL; 343 for (i = 0; i < fatent->nr_bhs; i++) 344 brelse(fatent->bhs[i]); 345 fatent->nr_bhs = 0; 346 fatent->bhs[0] = fatent->bhs[1] = NULL; 347 fatent->fat_inode = NULL; 348 } 349 350 extern void fat_ent_access_init(struct super_block *sb); 351 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 352 int entry); 353 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 354 int new, int wait); 355 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 356 int nr_cluster); 357 extern int fat_free_clusters(struct inode *inode, int cluster); 358 extern int fat_count_free_clusters(struct super_block *sb); 359 360 /* fat/file.c */ 361 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, 362 unsigned long arg); 363 extern const struct file_operations fat_file_operations; 364 extern const struct inode_operations fat_file_inode_operations; 365 extern int fat_setattr(struct dentry *dentry, struct iattr *attr); 366 extern void fat_truncate_blocks(struct inode *inode, loff_t offset); 367 extern int fat_getattr(const struct path *path, struct kstat *stat, 368 u32 request_mask, unsigned int flags); 369 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, 370 int datasync); 371 372 /* fat/inode.c */ 373 extern int fat_block_truncate_page(struct inode *inode, loff_t from); 374 extern void fat_attach(struct inode *inode, loff_t i_pos); 375 extern void fat_detach(struct inode *inode); 376 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 377 extern struct inode *fat_build_inode(struct super_block *sb, 378 struct msdos_dir_entry *de, loff_t i_pos); 379 extern int fat_sync_inode(struct inode *inode); 380 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 381 int isvfat, void (*setup)(struct super_block *)); 382 extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de); 383 384 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 385 struct inode *i2); 386 static inline unsigned long fat_dir_hash(int logstart) 387 { 388 return hash_32(logstart, FAT_HASH_BITS); 389 } 390 extern int fat_add_cluster(struct inode *inode); 391 392 /* fat/misc.c */ 393 extern __printf(3, 4) __cold 394 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); 395 #define fat_fs_error(sb, fmt, args...) \ 396 __fat_fs_error(sb, 1, fmt , ## args) 397 #define fat_fs_error_ratelimit(sb, fmt, args...) \ 398 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) 399 __printf(3, 4) __cold 400 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); 401 #define fat_msg_ratelimit(sb, level, fmt, args...) \ 402 do { \ 403 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ 404 fat_msg(sb, level, fmt, ## args); \ 405 } while (0) 406 extern int fat_clusters_flush(struct super_block *sb); 407 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 408 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, 409 __le16 __time, __le16 __date, u8 time_cs); 410 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, 411 __le16 *time, __le16 *date, u8 *time_cs); 412 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 413 414 int fat_cache_init(void); 415 void fat_cache_destroy(void); 416 417 /* fat/nfs.c */ 418 extern const struct export_operations fat_export_ops; 419 extern const struct export_operations fat_export_ops_nostale; 420 421 /* helper for printk */ 422 typedef unsigned long long llu; 423 424 #endif /* !_FAT_H */ 425