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