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