1 #ifndef _LINUX_MSDOS_FS_H 2 #define _LINUX_MSDOS_FS_H 3 4 #include <linux/magic.h> 5 6 /* 7 * The MS-DOS filesystem constants/structures 8 */ 9 #include <asm/byteorder.h> 10 11 #define SECTOR_SIZE 512 /* sector size (bytes) */ 12 #define SECTOR_BITS 9 /* log2(SECTOR_SIZE) */ 13 #define MSDOS_DPB (MSDOS_DPS) /* dir entries per block */ 14 #define MSDOS_DPB_BITS 4 /* log2(MSDOS_DPB) */ 15 #define MSDOS_DPS (SECTOR_SIZE / sizeof(struct msdos_dir_entry)) 16 #define MSDOS_DPS_BITS 4 /* log2(MSDOS_DPS) */ 17 #define CF_LE_W(v) le16_to_cpu(v) 18 #define CF_LE_L(v) le32_to_cpu(v) 19 #define CT_LE_W(v) cpu_to_le16(v) 20 #define CT_LE_L(v) cpu_to_le32(v) 21 22 23 #define MSDOS_ROOT_INO 1 /* == MINIX_ROOT_INO */ 24 #define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */ 25 26 /* directory limit */ 27 #define FAT_MAX_DIR_ENTRIES (65536) 28 #define FAT_MAX_DIR_SIZE (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS) 29 30 #define ATTR_NONE 0 /* no attribute bits */ 31 #define ATTR_RO 1 /* read-only */ 32 #define ATTR_HIDDEN 2 /* hidden */ 33 #define ATTR_SYS 4 /* system */ 34 #define ATTR_VOLUME 8 /* volume label */ 35 #define ATTR_DIR 16 /* directory */ 36 #define ATTR_ARCH 32 /* archived */ 37 38 /* attribute bits that are copied "as is" */ 39 #define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN) 40 /* bits that are used by the Windows 95/Windows NT extended FAT */ 41 #define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME) 42 43 #define CASE_LOWER_BASE 8 /* base is lower case */ 44 #define CASE_LOWER_EXT 16 /* extension is lower case */ 45 46 #define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */ 47 #define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG) 48 49 /* valid file mode bits */ 50 #define MSDOS_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO) 51 /* Convert attribute bits and a mask to the UNIX mode. */ 52 #define MSDOS_MKMODE(a, m) (m & (a & ATTR_RO ? S_IRUGO|S_IXUGO : S_IRWXUGO)) 53 54 #define MSDOS_NAME 11 /* maximum name length */ 55 #define MSDOS_LONGNAME 256 /* maximum name length */ 56 #define MSDOS_SLOTS 21 /* max # of slots for short and long names */ 57 #define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */ 58 #define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */ 59 60 #define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \ 61 MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x)) 62 63 /* start of data cluster's entry (number of reserved clusters) */ 64 #define FAT_START_ENT 2 65 66 /* maximum number of clusters */ 67 #define MAX_FAT12 0xFF4 68 #define MAX_FAT16 0xFFF4 69 #define MAX_FAT32 0x0FFFFFF6 70 #define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \ 71 MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12) 72 73 /* bad cluster mark */ 74 #define BAD_FAT12 0xFF7 75 #define BAD_FAT16 0xFFF7 76 #define BAD_FAT32 0x0FFFFFF7 77 78 /* standard EOF */ 79 #define EOF_FAT12 0xFFF 80 #define EOF_FAT16 0xFFFF 81 #define EOF_FAT32 0x0FFFFFFF 82 83 #define FAT_ENT_FREE (0) 84 #define FAT_ENT_BAD (BAD_FAT32) 85 #define FAT_ENT_EOF (EOF_FAT32) 86 87 #define FAT_FSINFO_SIG1 0x41615252 88 #define FAT_FSINFO_SIG2 0x61417272 89 #define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \ 90 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2) 91 92 /* 93 * ioctl commands 94 */ 95 #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2]) 96 #define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct dirent [2]) 97 /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */ 98 #define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32) 99 #define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32) 100 101 /* 102 * vfat shortname flags 103 */ 104 #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */ 105 #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */ 106 #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */ 107 #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */ 108 #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */ 109 110 struct fat_boot_sector { 111 __u8 ignored[3]; /* Boot strap short or near jump */ 112 __u8 system_id[8]; /* Name - can be used to special case 113 partition manager volumes */ 114 __u8 sector_size[2]; /* bytes per logical sector */ 115 __u8 sec_per_clus; /* sectors/cluster */ 116 __le16 reserved; /* reserved sectors */ 117 __u8 fats; /* number of FATs */ 118 __u8 dir_entries[2]; /* root directory entries */ 119 __u8 sectors[2]; /* number of sectors */ 120 __u8 media; /* media code */ 121 __le16 fat_length; /* sectors/FAT */ 122 __le16 secs_track; /* sectors per track */ 123 __le16 heads; /* number of heads */ 124 __le32 hidden; /* hidden sectors (unused) */ 125 __le32 total_sect; /* number of sectors (if sectors == 0) */ 126 127 /* The following fields are only used by FAT32 */ 128 __le32 fat32_length; /* sectors/FAT */ 129 __le16 flags; /* bit 8: fat mirroring, low 4: active fat */ 130 __u8 version[2]; /* major, minor filesystem version */ 131 __le32 root_cluster; /* first cluster in root directory */ 132 __le16 info_sector; /* filesystem info sector */ 133 __le16 backup_boot; /* backup boot sector */ 134 __le16 reserved2[6]; /* Unused */ 135 }; 136 137 struct fat_boot_fsinfo { 138 __le32 signature1; /* 0x41615252L */ 139 __le32 reserved1[120]; /* Nothing as far as I can tell */ 140 __le32 signature2; /* 0x61417272L */ 141 __le32 free_clusters; /* Free cluster count. -1 if unknown */ 142 __le32 next_cluster; /* Most recently allocated cluster */ 143 __le32 reserved2[4]; 144 }; 145 146 struct msdos_dir_entry { 147 __u8 name[MSDOS_NAME];/* name and extension */ 148 __u8 attr; /* attribute bits */ 149 __u8 lcase; /* Case for base and extension */ 150 __u8 ctime_cs; /* Creation time, centiseconds (0-199) */ 151 __le16 ctime; /* Creation time */ 152 __le16 cdate; /* Creation date */ 153 __le16 adate; /* Last access date */ 154 __le16 starthi; /* High 16 bits of cluster in FAT32 */ 155 __le16 time,date,start;/* time, date and first cluster */ 156 __le32 size; /* file size (in bytes) */ 157 }; 158 159 /* Up to 13 characters of the name */ 160 struct msdos_dir_slot { 161 __u8 id; /* sequence number for slot */ 162 __u8 name0_4[10]; /* first 5 characters in name */ 163 __u8 attr; /* attribute byte */ 164 __u8 reserved; /* always 0 */ 165 __u8 alias_checksum; /* checksum for 8.3 alias */ 166 __u8 name5_10[12]; /* 6 more characters in name */ 167 __le16 start; /* starting cluster number, 0 in long slots */ 168 __u8 name11_12[4]; /* last 2 characters in name */ 169 }; 170 171 struct fat_slot_info { 172 loff_t i_pos; /* on-disk position of directory entry */ 173 loff_t slot_off; /* offset for slot or de start */ 174 int nr_slots; /* number of slots + 1(de) in filename */ 175 struct msdos_dir_entry *de; 176 struct buffer_head *bh; 177 }; 178 179 #ifdef __KERNEL__ 180 181 #include <linux/buffer_head.h> 182 #include <linux/string.h> 183 #include <linux/nls.h> 184 #include <linux/fs.h> 185 #include <linux/mutex.h> 186 187 struct fat_mount_options { 188 uid_t fs_uid; 189 gid_t fs_gid; 190 unsigned short fs_fmask; 191 unsigned short fs_dmask; 192 unsigned short codepage; /* Codepage for shortname conversions */ 193 char *iocharset; /* Charset used for filename input/display */ 194 unsigned short shortname; /* flags for shortname display/create rule */ 195 unsigned char name_check; /* r = relaxed, n = normal, s = strict */ 196 unsigned short allow_utime;/* permission for setting the [am]time */ 197 unsigned quiet:1, /* set = fake successful chmods and chowns */ 198 showexec:1, /* set = only set x bit for com/exe/bat */ 199 sys_immutable:1, /* set = system files are immutable */ 200 dotsOK:1, /* set = hidden and system files are named '.filename' */ 201 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */ 202 utf8:1, /* Use of UTF-8 character set (Default) */ 203 unicode_xlate:1, /* create escape sequences for unhandled Unicode */ 204 numtail:1, /* Does first alias have a numeric '~1' type tail? */ 205 atari:1, /* Use Atari GEMDOS variation of MS-DOS fs */ 206 flush:1, /* write things quickly */ 207 nocase:1, /* Does this need case conversion? 0=need case conversion*/ 208 usefree:1; /* Use free_clusters for FAT32 */ 209 }; 210 211 #define FAT_HASH_BITS 8 212 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) 213 #define FAT_HASH_MASK (FAT_HASH_SIZE-1) 214 215 /* 216 * MS-DOS file system in-core superblock data 217 */ 218 struct msdos_sb_info { 219 unsigned short sec_per_clus; /* sectors/cluster */ 220 unsigned short cluster_bits; /* log2(cluster_size) */ 221 unsigned int cluster_size; /* cluster size */ 222 unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */ 223 unsigned short fat_start; 224 unsigned long fat_length; /* FAT start & length (sec.) */ 225 unsigned long dir_start; 226 unsigned short dir_entries; /* root dir start & entries */ 227 unsigned long data_start; /* first data sector */ 228 unsigned long max_cluster; /* maximum cluster number */ 229 unsigned long root_cluster; /* first cluster of the root directory */ 230 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ 231 struct mutex fat_lock; 232 unsigned int prev_free; /* previously allocated cluster number */ 233 unsigned int free_clusters; /* -1 if undefined */ 234 unsigned int free_clus_valid; /* is free_clusters valid? */ 235 struct fat_mount_options options; 236 struct nls_table *nls_disk; /* Codepage used on disk */ 237 struct nls_table *nls_io; /* Charset used for input and display */ 238 const void *dir_ops; /* Opaque; default directory operations */ 239 int dir_per_block; /* dir entries per block */ 240 int dir_per_block_bits; /* log2(dir_per_block) */ 241 242 int fatent_shift; 243 struct fatent_operations *fatent_ops; 244 245 spinlock_t inode_hash_lock; 246 struct hlist_head inode_hashtable[FAT_HASH_SIZE]; 247 }; 248 249 #define FAT_CACHE_VALID 0 /* special case for valid cache */ 250 251 /* 252 * MS-DOS file system inode data in memory 253 */ 254 struct msdos_inode_info { 255 spinlock_t cache_lru_lock; 256 struct list_head cache_lru; 257 int nr_caches; 258 /* for avoiding the race between fat_free() and fat_get_cluster() */ 259 unsigned int cache_valid_id; 260 261 loff_t mmu_private; 262 int i_start; /* first cluster or 0 */ 263 int i_logstart; /* logical first cluster */ 264 int i_attrs; /* unused attribute bits */ 265 loff_t i_pos; /* on-disk position of directory entry or 0 */ 266 struct hlist_node i_fat_hash; /* hash by i_location */ 267 struct inode vfs_inode; 268 }; 269 270 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 271 { 272 return sb->s_fs_info; 273 } 274 275 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 276 { 277 return container_of(inode, struct msdos_inode_info, vfs_inode); 278 } 279 280 /* Return the FAT attribute byte for this inode */ 281 static inline u8 fat_attr(struct inode *inode) 282 { 283 return ((inode->i_mode & S_IWUGO) ? ATTR_NONE : ATTR_RO) | 284 (S_ISDIR(inode->i_mode) ? ATTR_DIR : ATTR_NONE) | 285 MSDOS_I(inode)->i_attrs; 286 } 287 288 static inline unsigned char fat_checksum(const __u8 *name) 289 { 290 unsigned char s = name[0]; 291 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; 292 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; 293 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; 294 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; 295 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; 296 return s; 297 } 298 299 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) 300 { 301 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus 302 + sbi->data_start; 303 } 304 305 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) 306 { 307 #ifdef __BIG_ENDIAN 308 while (len--) { 309 *dst++ = src[0] | (src[1] << 8); 310 src += 2; 311 } 312 #else 313 memcpy(dst, src, len * 2); 314 #endif 315 } 316 317 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) 318 { 319 #ifdef __BIG_ENDIAN 320 while (len--) { 321 dst[0] = *src & 0x00FF; 322 dst[1] = (*src & 0xFF00) >> 8; 323 dst += 2; 324 src++; 325 } 326 #else 327 memcpy(dst, src, len * 2); 328 #endif 329 } 330 331 /* media of boot sector */ 332 static inline int fat_valid_media(u8 media) 333 { 334 return 0xf8 <= media || media == 0xf0; 335 } 336 337 /* fat/cache.c */ 338 extern void fat_cache_inval_inode(struct inode *inode); 339 extern int fat_get_cluster(struct inode *inode, int cluster, 340 int *fclus, int *dclus); 341 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 342 unsigned long *mapped_blocks); 343 344 /* fat/dir.c */ 345 extern const struct file_operations fat_dir_operations; 346 extern int fat_search_long(struct inode *inode, const unsigned char *name, 347 int name_len, struct fat_slot_info *sinfo); 348 extern int fat_dir_empty(struct inode *dir); 349 extern int fat_subdirs(struct inode *dir); 350 extern int fat_scan(struct inode *dir, const unsigned char *name, 351 struct fat_slot_info *sinfo); 352 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 353 struct msdos_dir_entry **de, loff_t *i_pos); 354 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 355 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 356 struct fat_slot_info *sinfo); 357 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 358 359 /* fat/fatent.c */ 360 struct fat_entry { 361 int entry; 362 union { 363 u8 *ent12_p[2]; 364 __le16 *ent16_p; 365 __le32 *ent32_p; 366 } u; 367 int nr_bhs; 368 struct buffer_head *bhs[2]; 369 }; 370 371 static inline void fatent_init(struct fat_entry *fatent) 372 { 373 fatent->nr_bhs = 0; 374 fatent->entry = 0; 375 fatent->u.ent32_p = NULL; 376 fatent->bhs[0] = fatent->bhs[1] = NULL; 377 } 378 379 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 380 { 381 fatent->entry = entry; 382 fatent->u.ent32_p = NULL; 383 } 384 385 static inline void fatent_brelse(struct fat_entry *fatent) 386 { 387 int i; 388 fatent->u.ent32_p = NULL; 389 for (i = 0; i < fatent->nr_bhs; i++) 390 brelse(fatent->bhs[i]); 391 fatent->nr_bhs = 0; 392 fatent->bhs[0] = fatent->bhs[1] = NULL; 393 } 394 395 extern void fat_ent_access_init(struct super_block *sb); 396 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 397 int entry); 398 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 399 int new, int wait); 400 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 401 int nr_cluster); 402 extern int fat_free_clusters(struct inode *inode, int cluster); 403 extern int fat_count_free_clusters(struct super_block *sb); 404 405 /* fat/file.c */ 406 extern int fat_generic_ioctl(struct inode *inode, struct file *filp, 407 unsigned int cmd, unsigned long arg); 408 extern const struct file_operations fat_file_operations; 409 extern const struct inode_operations fat_file_inode_operations; 410 extern int fat_setattr(struct dentry * dentry, struct iattr * attr); 411 extern void fat_truncate(struct inode *inode); 412 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, 413 struct kstat *stat); 414 415 /* fat/inode.c */ 416 extern void fat_attach(struct inode *inode, loff_t i_pos); 417 extern void fat_detach(struct inode *inode); 418 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 419 extern struct inode *fat_build_inode(struct super_block *sb, 420 struct msdos_dir_entry *de, loff_t i_pos); 421 extern int fat_sync_inode(struct inode *inode); 422 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 423 const struct inode_operations *fs_dir_inode_ops, int isvfat); 424 425 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 426 struct inode *i2); 427 /* fat/misc.c */ 428 extern void fat_fs_panic(struct super_block *s, const char *fmt, ...); 429 extern void fat_clusters_flush(struct super_block *sb); 430 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 431 extern int date_dos2unix(unsigned short time, unsigned short date); 432 extern void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date); 433 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 434 435 int fat_cache_init(void); 436 void fat_cache_destroy(void); 437 438 #endif /* __KERNEL__ */ 439 440 #endif 441