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 nfs_build_inode_lock; 79 struct mutex s_lock; 80 unsigned int prev_free; /* previously allocated cluster number */ 81 unsigned int free_clusters; /* -1 if undefined */ 82 unsigned int free_clus_valid; /* is free_clusters valid? */ 83 struct fat_mount_options options; 84 struct nls_table *nls_disk; /* Codepage used on disk */ 85 struct nls_table *nls_io; /* Charset used for input and display */ 86 const void *dir_ops; /* Opaque; default directory operations */ 87 int dir_per_block; /* dir entries per block */ 88 int dir_per_block_bits; /* log2(dir_per_block) */ 89 90 int fatent_shift; 91 struct fatent_operations *fatent_ops; 92 struct inode *fat_inode; 93 struct inode *fsinfo_inode; 94 95 struct ratelimit_state ratelimit; 96 97 spinlock_t inode_hash_lock; 98 struct hlist_head inode_hashtable[FAT_HASH_SIZE]; 99 100 spinlock_t dir_hash_lock; 101 struct hlist_head dir_hashtable[FAT_HASH_SIZE]; 102 103 unsigned int dirty; /* fs state before mount */ 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_bmap(struct inode *inode, sector_t sector, sector_t *phys, 289 unsigned long *mapped_blocks, int create); 290 291 /* fat/dir.c */ 292 extern const struct file_operations fat_dir_operations; 293 extern int fat_search_long(struct inode *inode, const unsigned char *name, 294 int name_len, struct fat_slot_info *sinfo); 295 extern int fat_dir_empty(struct inode *dir); 296 extern int fat_subdirs(struct inode *dir); 297 extern int fat_scan(struct inode *dir, const unsigned char *name, 298 struct fat_slot_info *sinfo); 299 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 300 struct msdos_dir_entry **de); 301 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 302 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 303 struct fat_slot_info *sinfo); 304 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 305 306 /* fat/fatent.c */ 307 struct fat_entry { 308 int entry; 309 union { 310 u8 *ent12_p[2]; 311 __le16 *ent16_p; 312 __le32 *ent32_p; 313 } u; 314 int nr_bhs; 315 struct buffer_head *bhs[2]; 316 struct inode *fat_inode; 317 }; 318 319 static inline void fatent_init(struct fat_entry *fatent) 320 { 321 fatent->nr_bhs = 0; 322 fatent->entry = 0; 323 fatent->u.ent32_p = NULL; 324 fatent->bhs[0] = fatent->bhs[1] = NULL; 325 fatent->fat_inode = NULL; 326 } 327 328 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 329 { 330 fatent->entry = entry; 331 fatent->u.ent32_p = NULL; 332 } 333 334 static inline void fatent_brelse(struct fat_entry *fatent) 335 { 336 int i; 337 fatent->u.ent32_p = NULL; 338 for (i = 0; i < fatent->nr_bhs; i++) 339 brelse(fatent->bhs[i]); 340 fatent->nr_bhs = 0; 341 fatent->bhs[0] = fatent->bhs[1] = NULL; 342 fatent->fat_inode = NULL; 343 } 344 345 extern void fat_ent_access_init(struct super_block *sb); 346 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 347 int entry); 348 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 349 int new, int wait); 350 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 351 int nr_cluster); 352 extern int fat_free_clusters(struct inode *inode, int cluster); 353 extern int fat_count_free_clusters(struct super_block *sb); 354 355 /* fat/file.c */ 356 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, 357 unsigned long arg); 358 extern const struct file_operations fat_file_operations; 359 extern const struct inode_operations fat_file_inode_operations; 360 extern int fat_setattr(struct dentry *dentry, struct iattr *attr); 361 extern void fat_truncate_blocks(struct inode *inode, loff_t offset); 362 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, 363 struct kstat *stat); 364 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, 365 int datasync); 366 367 /* fat/inode.c */ 368 extern void fat_attach(struct inode *inode, loff_t i_pos); 369 extern void fat_detach(struct inode *inode); 370 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 371 extern struct inode *fat_build_inode(struct super_block *sb, 372 struct msdos_dir_entry *de, loff_t i_pos); 373 extern int fat_sync_inode(struct inode *inode); 374 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 375 int isvfat, void (*setup)(struct super_block *)); 376 377 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 378 struct inode *i2); 379 static inline unsigned long fat_dir_hash(int logstart) 380 { 381 return hash_32(logstart, FAT_HASH_BITS); 382 } 383 384 /* fat/misc.c */ 385 extern __printf(3, 4) __cold 386 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); 387 #define fat_fs_error(sb, fmt, args...) \ 388 __fat_fs_error(sb, 1, fmt , ## args) 389 #define fat_fs_error_ratelimit(sb, fmt, args...) \ 390 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) 391 __printf(3, 4) __cold 392 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); 393 #define fat_msg_ratelimit(sb, level, fmt, args...) \ 394 do { \ 395 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ 396 fat_msg(sb, level, fmt, ## args); \ 397 } while (0) 398 extern int fat_clusters_flush(struct super_block *sb); 399 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 400 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, 401 __le16 __time, __le16 __date, u8 time_cs); 402 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, 403 __le16 *time, __le16 *date, u8 *time_cs); 404 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 405 406 int fat_cache_init(void); 407 void fat_cache_destroy(void); 408 409 /* fat/nfs.c */ 410 extern const struct export_operations fat_export_ops; 411 extern const struct export_operations fat_export_ops_nostale; 412 413 /* helper for printk */ 414 typedef unsigned long long llu; 415 416 #endif /* !_FAT_H */ 417