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 struct fat_mount_options { 27 kuid_t fs_uid; 28 kgid_t fs_gid; 29 unsigned short fs_fmask; 30 unsigned short fs_dmask; 31 unsigned short codepage; /* Codepage for shortname conversions */ 32 char *iocharset; /* Charset used for filename input/display */ 33 unsigned short shortname; /* flags for shortname display/create rule */ 34 unsigned char name_check; /* r = relaxed, n = normal, s = strict */ 35 unsigned char errors; /* On error: continue, panic, remount-ro */ 36 unsigned short allow_utime;/* permission for setting the [am]time */ 37 unsigned quiet:1, /* set = fake successful chmods and chowns */ 38 showexec:1, /* set = only set x bit for com/exe/bat */ 39 sys_immutable:1, /* set = system files are immutable */ 40 dotsOK:1, /* set = hidden and system files are named '.filename' */ 41 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */ 42 utf8:1, /* Use of UTF-8 character set (Default) */ 43 unicode_xlate:1, /* create escape sequences for unhandled Unicode */ 44 numtail:1, /* Does first alias have a numeric '~1' type tail? */ 45 flush:1, /* write things quickly */ 46 nocase:1, /* Does this need case conversion? 0=need case conversion*/ 47 usefree:1, /* Use free_clusters for FAT32 */ 48 tz_utc:1, /* Filesystem timestamps are in UTC */ 49 rodir:1, /* allow ATTR_RO for directory */ 50 discard:1, /* Issue discard requests on deletions */ 51 nfs:1; /* Do extra work needed for NFS export */ 52 }; 53 54 #define FAT_HASH_BITS 8 55 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) 56 57 /* 58 * MS-DOS file system in-core superblock data 59 */ 60 struct msdos_sb_info { 61 unsigned short sec_per_clus; /* sectors/cluster */ 62 unsigned short cluster_bits; /* log2(cluster_size) */ 63 unsigned int cluster_size; /* cluster size */ 64 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */ 65 unsigned short fat_start; 66 unsigned long fat_length; /* FAT start & length (sec.) */ 67 unsigned long dir_start; 68 unsigned short dir_entries; /* root dir start & entries */ 69 unsigned long data_start; /* first data sector */ 70 unsigned long max_cluster; /* maximum cluster number */ 71 unsigned long root_cluster; /* first cluster of the root directory */ 72 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ 73 struct mutex fat_lock; 74 struct mutex s_lock; 75 unsigned int prev_free; /* previously allocated cluster number */ 76 unsigned int free_clusters; /* -1 if undefined */ 77 unsigned int free_clus_valid; /* is free_clusters valid? */ 78 struct fat_mount_options options; 79 struct nls_table *nls_disk; /* Codepage used on disk */ 80 struct nls_table *nls_io; /* Charset used for input and display */ 81 const void *dir_ops; /* Opaque; default directory operations */ 82 int dir_per_block; /* dir entries per block */ 83 int dir_per_block_bits; /* log2(dir_per_block) */ 84 85 int fatent_shift; 86 struct fatent_operations *fatent_ops; 87 struct inode *fat_inode; 88 struct inode *fsinfo_inode; 89 90 struct ratelimit_state ratelimit; 91 92 spinlock_t inode_hash_lock; 93 struct hlist_head inode_hashtable[FAT_HASH_SIZE]; 94 95 spinlock_t dir_hash_lock; 96 struct hlist_head dir_hashtable[FAT_HASH_SIZE]; 97 }; 98 99 #define FAT_CACHE_VALID 0 /* special case for valid cache */ 100 101 /* 102 * MS-DOS file system inode data in memory 103 */ 104 struct msdos_inode_info { 105 spinlock_t cache_lru_lock; 106 struct list_head cache_lru; 107 int nr_caches; 108 /* for avoiding the race between fat_free() and fat_get_cluster() */ 109 unsigned int cache_valid_id; 110 111 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ 112 loff_t mmu_private; /* physically allocated size */ 113 114 int i_start; /* first cluster or 0 */ 115 int i_logstart; /* logical first cluster */ 116 int i_attrs; /* unused attribute bits */ 117 loff_t i_pos; /* on-disk position of directory entry or 0 */ 118 struct hlist_node i_fat_hash; /* hash by i_location */ 119 struct hlist_node i_dir_hash; /* hash by i_logstart */ 120 struct rw_semaphore truncate_lock; /* protect bmap against truncate */ 121 struct inode vfs_inode; 122 }; 123 124 struct fat_slot_info { 125 loff_t i_pos; /* on-disk position of directory entry */ 126 loff_t slot_off; /* offset for slot or de start */ 127 int nr_slots; /* number of slots + 1(de) in filename */ 128 struct msdos_dir_entry *de; 129 struct buffer_head *bh; 130 }; 131 132 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 133 { 134 return sb->s_fs_info; 135 } 136 137 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 138 { 139 return container_of(inode, struct msdos_inode_info, vfs_inode); 140 } 141 142 /* 143 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to 144 * save ATTR_RO instead of ->i_mode. 145 * 146 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only 147 * bit, it's just used as flag for app. 148 */ 149 static inline int fat_mode_can_hold_ro(struct inode *inode) 150 { 151 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 152 umode_t mask; 153 154 if (S_ISDIR(inode->i_mode)) { 155 if (!sbi->options.rodir) 156 return 0; 157 mask = ~sbi->options.fs_dmask; 158 } else 159 mask = ~sbi->options.fs_fmask; 160 161 if (!(mask & S_IWUGO)) 162 return 0; 163 return 1; 164 } 165 166 /* Convert attribute bits and a mask to the UNIX mode. */ 167 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi, 168 u8 attrs, umode_t mode) 169 { 170 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir)) 171 mode &= ~S_IWUGO; 172 173 if (attrs & ATTR_DIR) 174 return (mode & ~sbi->options.fs_dmask) | S_IFDIR; 175 else 176 return (mode & ~sbi->options.fs_fmask) | S_IFREG; 177 } 178 179 /* Return the FAT attribute byte for this inode */ 180 static inline u8 fat_make_attrs(struct inode *inode) 181 { 182 u8 attrs = MSDOS_I(inode)->i_attrs; 183 if (S_ISDIR(inode->i_mode)) 184 attrs |= ATTR_DIR; 185 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) 186 attrs |= ATTR_RO; 187 return attrs; 188 } 189 190 static inline void fat_save_attrs(struct inode *inode, u8 attrs) 191 { 192 if (fat_mode_can_hold_ro(inode)) 193 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; 194 else 195 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); 196 } 197 198 static inline unsigned char fat_checksum(const __u8 *name) 199 { 200 unsigned char s = name[0]; 201 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; 202 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; 203 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; 204 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; 205 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; 206 return s; 207 } 208 209 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) 210 { 211 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus 212 + sbi->data_start; 213 } 214 215 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) 216 { 217 #ifdef __BIG_ENDIAN 218 while (len--) { 219 *dst++ = src[0] | (src[1] << 8); 220 src += 2; 221 } 222 #else 223 memcpy(dst, src, len * 2); 224 #endif 225 } 226 227 static inline int fat_get_start(const struct msdos_sb_info *sbi, 228 const struct msdos_dir_entry *de) 229 { 230 int cluster = le16_to_cpu(de->start); 231 if (sbi->fat_bits == 32) 232 cluster |= (le16_to_cpu(de->starthi) << 16); 233 return cluster; 234 } 235 236 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster) 237 { 238 de->start = cpu_to_le16(cluster); 239 de->starthi = cpu_to_le16(cluster >> 16); 240 } 241 242 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) 243 { 244 #ifdef __BIG_ENDIAN 245 while (len--) { 246 dst[0] = *src & 0x00FF; 247 dst[1] = (*src & 0xFF00) >> 8; 248 dst += 2; 249 src++; 250 } 251 #else 252 memcpy(dst, src, len * 2); 253 #endif 254 } 255 256 /* fat/cache.c */ 257 extern void fat_cache_inval_inode(struct inode *inode); 258 extern int fat_get_cluster(struct inode *inode, int cluster, 259 int *fclus, int *dclus); 260 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 261 unsigned long *mapped_blocks, int create); 262 263 /* fat/dir.c */ 264 extern const struct file_operations fat_dir_operations; 265 extern int fat_search_long(struct inode *inode, const unsigned char *name, 266 int name_len, struct fat_slot_info *sinfo); 267 extern int fat_dir_empty(struct inode *dir); 268 extern int fat_subdirs(struct inode *dir); 269 extern int fat_scan(struct inode *dir, const unsigned char *name, 270 struct fat_slot_info *sinfo); 271 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 272 struct msdos_dir_entry **de); 273 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 274 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 275 struct fat_slot_info *sinfo); 276 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 277 278 /* fat/fatent.c */ 279 struct fat_entry { 280 int entry; 281 union { 282 u8 *ent12_p[2]; 283 __le16 *ent16_p; 284 __le32 *ent32_p; 285 } u; 286 int nr_bhs; 287 struct buffer_head *bhs[2]; 288 struct inode *fat_inode; 289 }; 290 291 static inline void fatent_init(struct fat_entry *fatent) 292 { 293 fatent->nr_bhs = 0; 294 fatent->entry = 0; 295 fatent->u.ent32_p = NULL; 296 fatent->bhs[0] = fatent->bhs[1] = NULL; 297 fatent->fat_inode = NULL; 298 } 299 300 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 301 { 302 fatent->entry = entry; 303 fatent->u.ent32_p = NULL; 304 } 305 306 static inline void fatent_brelse(struct fat_entry *fatent) 307 { 308 int i; 309 fatent->u.ent32_p = NULL; 310 for (i = 0; i < fatent->nr_bhs; i++) 311 brelse(fatent->bhs[i]); 312 fatent->nr_bhs = 0; 313 fatent->bhs[0] = fatent->bhs[1] = NULL; 314 fatent->fat_inode = NULL; 315 } 316 317 extern void fat_ent_access_init(struct super_block *sb); 318 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 319 int entry); 320 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 321 int new, int wait); 322 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 323 int nr_cluster); 324 extern int fat_free_clusters(struct inode *inode, int cluster); 325 extern int fat_count_free_clusters(struct super_block *sb); 326 327 /* fat/file.c */ 328 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, 329 unsigned long arg); 330 extern const struct file_operations fat_file_operations; 331 extern const struct inode_operations fat_file_inode_operations; 332 extern int fat_setattr(struct dentry *dentry, struct iattr *attr); 333 extern void fat_truncate_blocks(struct inode *inode, loff_t offset); 334 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, 335 struct kstat *stat); 336 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, 337 int datasync); 338 339 /* fat/inode.c */ 340 extern void fat_attach(struct inode *inode, loff_t i_pos); 341 extern void fat_detach(struct inode *inode); 342 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 343 extern struct inode *fat_build_inode(struct super_block *sb, 344 struct msdos_dir_entry *de, loff_t i_pos); 345 extern int fat_sync_inode(struct inode *inode); 346 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 347 int isvfat, void (*setup)(struct super_block *)); 348 349 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 350 struct inode *i2); 351 static inline unsigned long fat_dir_hash(int logstart) 352 { 353 return hash_32(logstart, FAT_HASH_BITS); 354 } 355 356 /* fat/misc.c */ 357 extern __printf(3, 4) __cold 358 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); 359 #define fat_fs_error(sb, fmt, args...) \ 360 __fat_fs_error(sb, 1, fmt , ## args) 361 #define fat_fs_error_ratelimit(sb, fmt, args...) \ 362 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) 363 __printf(3, 4) __cold 364 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); 365 #define fat_msg_ratelimit(sb, level, fmt, args...) \ 366 do { \ 367 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ 368 fat_msg(sb, level, fmt, ## args); \ 369 } while (0) 370 extern int fat_clusters_flush(struct super_block *sb); 371 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 372 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, 373 __le16 __time, __le16 __date, u8 time_cs); 374 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, 375 __le16 *time, __le16 *date, u8 *time_cs); 376 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 377 378 int fat_cache_init(void); 379 void fat_cache_destroy(void); 380 381 /* fat/nfs.c */ 382 struct fid; 383 extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, 384 int fh_len, int fh_type); 385 extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, 386 int fh_len, int fh_type); 387 extern struct dentry *fat_get_parent(struct dentry *child_dir); 388 389 /* helper for printk */ 390 typedef unsigned long long llu; 391 392 #endif /* !_FAT_H */ 393