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 }; 57 58 #define FAT_HASH_BITS 8 59 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) 60 61 /* 62 * MS-DOS file system in-core superblock data 63 */ 64 struct msdos_sb_info { 65 unsigned short sec_per_clus; /* sectors/cluster */ 66 unsigned short cluster_bits; /* log2(cluster_size) */ 67 unsigned int cluster_size; /* cluster size */ 68 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */ 69 unsigned short fat_start; 70 unsigned long fat_length; /* FAT start & length (sec.) */ 71 unsigned long dir_start; 72 unsigned short dir_entries; /* root dir start & entries */ 73 unsigned long data_start; /* first data sector */ 74 unsigned long max_cluster; /* maximum cluster number */ 75 unsigned long root_cluster; /* first cluster of the root directory */ 76 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ 77 struct mutex fat_lock; 78 struct mutex s_lock; 79 unsigned int prev_free; /* previously allocated cluster number */ 80 unsigned int free_clusters; /* -1 if undefined */ 81 unsigned int free_clus_valid; /* is free_clusters valid? */ 82 struct fat_mount_options options; 83 struct nls_table *nls_disk; /* Codepage used on disk */ 84 struct nls_table *nls_io; /* Charset used for input and display */ 85 const void *dir_ops; /* Opaque; default directory operations */ 86 int dir_per_block; /* dir entries per block */ 87 int dir_per_block_bits; /* log2(dir_per_block) */ 88 89 int fatent_shift; 90 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 }; 104 105 #define FAT_CACHE_VALID 0 /* special case for valid cache */ 106 107 /* 108 * MS-DOS file system inode data in memory 109 */ 110 struct msdos_inode_info { 111 spinlock_t cache_lru_lock; 112 struct list_head cache_lru; 113 int nr_caches; 114 /* for avoiding the race between fat_free() and fat_get_cluster() */ 115 unsigned int cache_valid_id; 116 117 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ 118 loff_t mmu_private; /* physically allocated size */ 119 120 int i_start; /* first cluster or 0 */ 121 int i_logstart; /* logical first cluster */ 122 int i_attrs; /* unused attribute bits */ 123 loff_t i_pos; /* on-disk position of directory entry or 0 */ 124 struct hlist_node i_fat_hash; /* hash by i_location */ 125 struct hlist_node i_dir_hash; /* hash by i_logstart */ 126 struct rw_semaphore truncate_lock; /* protect bmap against truncate */ 127 struct inode vfs_inode; 128 }; 129 130 struct fat_slot_info { 131 loff_t i_pos; /* on-disk position of directory entry */ 132 loff_t slot_off; /* offset for slot or de start */ 133 int nr_slots; /* number of slots + 1(de) in filename */ 134 struct msdos_dir_entry *de; 135 struct buffer_head *bh; 136 }; 137 138 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 139 { 140 return sb->s_fs_info; 141 } 142 143 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 144 { 145 return container_of(inode, struct msdos_inode_info, vfs_inode); 146 } 147 148 /* 149 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to 150 * save ATTR_RO instead of ->i_mode. 151 * 152 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only 153 * bit, it's just used as flag for app. 154 */ 155 static inline int fat_mode_can_hold_ro(struct inode *inode) 156 { 157 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 158 umode_t mask; 159 160 if (S_ISDIR(inode->i_mode)) { 161 if (!sbi->options.rodir) 162 return 0; 163 mask = ~sbi->options.fs_dmask; 164 } else 165 mask = ~sbi->options.fs_fmask; 166 167 if (!(mask & S_IWUGO)) 168 return 0; 169 return 1; 170 } 171 172 /* Convert attribute bits and a mask to the UNIX mode. */ 173 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi, 174 u8 attrs, umode_t mode) 175 { 176 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir)) 177 mode &= ~S_IWUGO; 178 179 if (attrs & ATTR_DIR) 180 return (mode & ~sbi->options.fs_dmask) | S_IFDIR; 181 else 182 return (mode & ~sbi->options.fs_fmask) | S_IFREG; 183 } 184 185 /* Return the FAT attribute byte for this inode */ 186 static inline u8 fat_make_attrs(struct inode *inode) 187 { 188 u8 attrs = MSDOS_I(inode)->i_attrs; 189 if (S_ISDIR(inode->i_mode)) 190 attrs |= ATTR_DIR; 191 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) 192 attrs |= ATTR_RO; 193 return attrs; 194 } 195 196 static inline void fat_save_attrs(struct inode *inode, u8 attrs) 197 { 198 if (fat_mode_can_hold_ro(inode)) 199 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; 200 else 201 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); 202 } 203 204 static inline unsigned char fat_checksum(const __u8 *name) 205 { 206 unsigned char s = name[0]; 207 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; 208 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; 209 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; 210 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; 211 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; 212 return s; 213 } 214 215 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) 216 { 217 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus 218 + sbi->data_start; 219 } 220 221 static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi, 222 loff_t i_pos, sector_t *blknr, int *offset) 223 { 224 *blknr = i_pos >> sbi->dir_per_block_bits; 225 *offset = i_pos & (sbi->dir_per_block - 1); 226 } 227 228 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, 229 struct inode *inode) 230 { 231 loff_t i_pos; 232 #if BITS_PER_LONG == 32 233 spin_lock(&sbi->inode_hash_lock); 234 #endif 235 i_pos = MSDOS_I(inode)->i_pos; 236 #if BITS_PER_LONG == 32 237 spin_unlock(&sbi->inode_hash_lock); 238 #endif 239 return i_pos; 240 } 241 242 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) 243 { 244 #ifdef __BIG_ENDIAN 245 while (len--) { 246 *dst++ = src[0] | (src[1] << 8); 247 src += 2; 248 } 249 #else 250 memcpy(dst, src, len * 2); 251 #endif 252 } 253 254 static inline int fat_get_start(const struct msdos_sb_info *sbi, 255 const struct msdos_dir_entry *de) 256 { 257 int cluster = le16_to_cpu(de->start); 258 if (sbi->fat_bits == 32) 259 cluster |= (le16_to_cpu(de->starthi) << 16); 260 return cluster; 261 } 262 263 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster) 264 { 265 de->start = cpu_to_le16(cluster); 266 de->starthi = cpu_to_le16(cluster >> 16); 267 } 268 269 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) 270 { 271 #ifdef __BIG_ENDIAN 272 while (len--) { 273 dst[0] = *src & 0x00FF; 274 dst[1] = (*src & 0xFF00) >> 8; 275 dst += 2; 276 src++; 277 } 278 #else 279 memcpy(dst, src, len * 2); 280 #endif 281 } 282 283 /* fat/cache.c */ 284 extern void fat_cache_inval_inode(struct inode *inode); 285 extern int fat_get_cluster(struct inode *inode, int cluster, 286 int *fclus, int *dclus); 287 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 288 unsigned long *mapped_blocks, int create); 289 290 /* fat/dir.c */ 291 extern const struct file_operations fat_dir_operations; 292 extern int fat_search_long(struct inode *inode, const unsigned char *name, 293 int name_len, struct fat_slot_info *sinfo); 294 extern int fat_dir_empty(struct inode *dir); 295 extern int fat_subdirs(struct inode *dir); 296 extern int fat_scan(struct inode *dir, const unsigned char *name, 297 struct fat_slot_info *sinfo); 298 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 299 struct msdos_dir_entry **de); 300 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 301 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 302 struct fat_slot_info *sinfo); 303 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 304 305 /* fat/fatent.c */ 306 struct fat_entry { 307 int entry; 308 union { 309 u8 *ent12_p[2]; 310 __le16 *ent16_p; 311 __le32 *ent32_p; 312 } u; 313 int nr_bhs; 314 struct buffer_head *bhs[2]; 315 struct inode *fat_inode; 316 }; 317 318 static inline void fatent_init(struct fat_entry *fatent) 319 { 320 fatent->nr_bhs = 0; 321 fatent->entry = 0; 322 fatent->u.ent32_p = NULL; 323 fatent->bhs[0] = fatent->bhs[1] = NULL; 324 fatent->fat_inode = NULL; 325 } 326 327 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 328 { 329 fatent->entry = entry; 330 fatent->u.ent32_p = NULL; 331 } 332 333 static inline void fatent_brelse(struct fat_entry *fatent) 334 { 335 int i; 336 fatent->u.ent32_p = NULL; 337 for (i = 0; i < fatent->nr_bhs; i++) 338 brelse(fatent->bhs[i]); 339 fatent->nr_bhs = 0; 340 fatent->bhs[0] = fatent->bhs[1] = NULL; 341 fatent->fat_inode = NULL; 342 } 343 344 extern void fat_ent_access_init(struct super_block *sb); 345 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 346 int entry); 347 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 348 int new, int wait); 349 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 350 int nr_cluster); 351 extern int fat_free_clusters(struct inode *inode, int cluster); 352 extern int fat_count_free_clusters(struct super_block *sb); 353 354 /* fat/file.c */ 355 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, 356 unsigned long arg); 357 extern const struct file_operations fat_file_operations; 358 extern const struct inode_operations fat_file_inode_operations; 359 extern int fat_setattr(struct dentry *dentry, struct iattr *attr); 360 extern void fat_truncate_blocks(struct inode *inode, loff_t offset); 361 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, 362 struct kstat *stat); 363 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, 364 int datasync); 365 366 /* fat/inode.c */ 367 extern void fat_attach(struct inode *inode, loff_t i_pos); 368 extern void fat_detach(struct inode *inode); 369 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 370 extern struct inode *fat_build_inode(struct super_block *sb, 371 struct msdos_dir_entry *de, loff_t i_pos); 372 extern int fat_sync_inode(struct inode *inode); 373 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 374 int isvfat, void (*setup)(struct super_block *)); 375 376 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 377 struct inode *i2); 378 static inline unsigned long fat_dir_hash(int logstart) 379 { 380 return hash_32(logstart, FAT_HASH_BITS); 381 } 382 383 /* fat/misc.c */ 384 extern __printf(3, 4) __cold 385 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); 386 #define fat_fs_error(sb, fmt, args...) \ 387 __fat_fs_error(sb, 1, fmt , ## args) 388 #define fat_fs_error_ratelimit(sb, fmt, args...) \ 389 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) 390 __printf(3, 4) __cold 391 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); 392 #define fat_msg_ratelimit(sb, level, fmt, args...) \ 393 do { \ 394 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ 395 fat_msg(sb, level, fmt, ## args); \ 396 } while (0) 397 extern int fat_clusters_flush(struct super_block *sb); 398 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 399 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, 400 __le16 __time, __le16 __date, u8 time_cs); 401 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, 402 __le16 *time, __le16 *date, u8 *time_cs); 403 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 404 405 int fat_cache_init(void); 406 void fat_cache_destroy(void); 407 408 /* fat/nfs.c */ 409 extern const struct export_operations fat_export_ops; 410 extern const struct export_operations fat_export_ops_nostale; 411 412 /* helper for printk */ 413 typedef unsigned long long llu; 414 415 #endif /* !_FAT_H */ 416