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 int time_offset; /* Offset of timestamps from UTC (in minutes) */ 33 char *iocharset; /* Charset used for filename input/display */ 34 unsigned short shortname; /* flags for shortname display/create rule */ 35 unsigned char name_check; /* r = relaxed, n = normal, s = strict */ 36 unsigned char errors; /* On error: continue, panic, remount-ro */ 37 unsigned short allow_utime;/* permission for setting the [am]time */ 38 unsigned quiet:1, /* set = fake successful chmods and chowns */ 39 showexec:1, /* set = only set x bit for com/exe/bat */ 40 sys_immutable:1, /* set = system files are immutable */ 41 dotsOK:1, /* set = hidden and system files are named '.filename' */ 42 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */ 43 utf8:1, /* Use of UTF-8 character set (Default) */ 44 unicode_xlate:1, /* create escape sequences for unhandled Unicode */ 45 numtail:1, /* Does first alias have a numeric '~1' type tail? */ 46 flush:1, /* write things quickly */ 47 nocase:1, /* Does this need case conversion? 0=need case conversion*/ 48 usefree:1, /* Use free_clusters for FAT32 */ 49 tz_set:1, /* Filesystem timestamps' offset set */ 50 rodir:1, /* allow ATTR_RO for directory */ 51 discard:1, /* Issue discard requests on deletions */ 52 nfs:1; /* Do extra work needed for NFS export */ 53 }; 54 55 #define FAT_HASH_BITS 8 56 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) 57 58 /* 59 * MS-DOS file system in-core superblock data 60 */ 61 struct msdos_sb_info { 62 unsigned short sec_per_clus; /* sectors/cluster */ 63 unsigned short cluster_bits; /* log2(cluster_size) */ 64 unsigned int cluster_size; /* cluster size */ 65 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */ 66 unsigned short fat_start; 67 unsigned long fat_length; /* FAT start & length (sec.) */ 68 unsigned long dir_start; 69 unsigned short dir_entries; /* root dir start & entries */ 70 unsigned long data_start; /* first data sector */ 71 unsigned long max_cluster; /* maximum cluster number */ 72 unsigned long root_cluster; /* first cluster of the root directory */ 73 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ 74 struct mutex fat_lock; 75 struct mutex s_lock; 76 unsigned int prev_free; /* previously allocated cluster number */ 77 unsigned int free_clusters; /* -1 if undefined */ 78 unsigned int free_clus_valid; /* is free_clusters valid? */ 79 struct fat_mount_options options; 80 struct nls_table *nls_disk; /* Codepage used on disk */ 81 struct nls_table *nls_io; /* Charset used for input and display */ 82 const void *dir_ops; /* Opaque; default directory operations */ 83 int dir_per_block; /* dir entries per block */ 84 int dir_per_block_bits; /* log2(dir_per_block) */ 85 86 int fatent_shift; 87 struct fatent_operations *fatent_ops; 88 struct inode *fat_inode; 89 struct inode *fsinfo_inode; 90 91 struct ratelimit_state ratelimit; 92 93 spinlock_t inode_hash_lock; 94 struct hlist_head inode_hashtable[FAT_HASH_SIZE]; 95 96 spinlock_t dir_hash_lock; 97 struct hlist_head dir_hashtable[FAT_HASH_SIZE]; 98 }; 99 100 #define FAT_CACHE_VALID 0 /* special case for valid cache */ 101 102 /* 103 * MS-DOS file system inode data in memory 104 */ 105 struct msdos_inode_info { 106 spinlock_t cache_lru_lock; 107 struct list_head cache_lru; 108 int nr_caches; 109 /* for avoiding the race between fat_free() and fat_get_cluster() */ 110 unsigned int cache_valid_id; 111 112 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ 113 loff_t mmu_private; /* physically allocated size */ 114 115 int i_start; /* first cluster or 0 */ 116 int i_logstart; /* logical first cluster */ 117 int i_attrs; /* unused attribute bits */ 118 loff_t i_pos; /* on-disk position of directory entry or 0 */ 119 struct hlist_node i_fat_hash; /* hash by i_location */ 120 struct hlist_node i_dir_hash; /* hash by i_logstart */ 121 struct rw_semaphore truncate_lock; /* protect bmap against truncate */ 122 struct inode vfs_inode; 123 }; 124 125 struct fat_slot_info { 126 loff_t i_pos; /* on-disk position of directory entry */ 127 loff_t slot_off; /* offset for slot or de start */ 128 int nr_slots; /* number of slots + 1(de) in filename */ 129 struct msdos_dir_entry *de; 130 struct buffer_head *bh; 131 }; 132 133 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 134 { 135 return sb->s_fs_info; 136 } 137 138 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 139 { 140 return container_of(inode, struct msdos_inode_info, vfs_inode); 141 } 142 143 /* 144 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to 145 * save ATTR_RO instead of ->i_mode. 146 * 147 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only 148 * bit, it's just used as flag for app. 149 */ 150 static inline int fat_mode_can_hold_ro(struct inode *inode) 151 { 152 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); 153 umode_t mask; 154 155 if (S_ISDIR(inode->i_mode)) { 156 if (!sbi->options.rodir) 157 return 0; 158 mask = ~sbi->options.fs_dmask; 159 } else 160 mask = ~sbi->options.fs_fmask; 161 162 if (!(mask & S_IWUGO)) 163 return 0; 164 return 1; 165 } 166 167 /* Convert attribute bits and a mask to the UNIX mode. */ 168 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi, 169 u8 attrs, umode_t mode) 170 { 171 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir)) 172 mode &= ~S_IWUGO; 173 174 if (attrs & ATTR_DIR) 175 return (mode & ~sbi->options.fs_dmask) | S_IFDIR; 176 else 177 return (mode & ~sbi->options.fs_fmask) | S_IFREG; 178 } 179 180 /* Return the FAT attribute byte for this inode */ 181 static inline u8 fat_make_attrs(struct inode *inode) 182 { 183 u8 attrs = MSDOS_I(inode)->i_attrs; 184 if (S_ISDIR(inode->i_mode)) 185 attrs |= ATTR_DIR; 186 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) 187 attrs |= ATTR_RO; 188 return attrs; 189 } 190 191 static inline void fat_save_attrs(struct inode *inode, u8 attrs) 192 { 193 if (fat_mode_can_hold_ro(inode)) 194 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; 195 else 196 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); 197 } 198 199 static inline unsigned char fat_checksum(const __u8 *name) 200 { 201 unsigned char s = name[0]; 202 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; 203 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; 204 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; 205 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; 206 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; 207 return s; 208 } 209 210 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) 211 { 212 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus 213 + sbi->data_start; 214 } 215 216 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) 217 { 218 #ifdef __BIG_ENDIAN 219 while (len--) { 220 *dst++ = src[0] | (src[1] << 8); 221 src += 2; 222 } 223 #else 224 memcpy(dst, src, len * 2); 225 #endif 226 } 227 228 static inline int fat_get_start(const struct msdos_sb_info *sbi, 229 const struct msdos_dir_entry *de) 230 { 231 int cluster = le16_to_cpu(de->start); 232 if (sbi->fat_bits == 32) 233 cluster |= (le16_to_cpu(de->starthi) << 16); 234 return cluster; 235 } 236 237 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster) 238 { 239 de->start = cpu_to_le16(cluster); 240 de->starthi = cpu_to_le16(cluster >> 16); 241 } 242 243 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) 244 { 245 #ifdef __BIG_ENDIAN 246 while (len--) { 247 dst[0] = *src & 0x00FF; 248 dst[1] = (*src & 0xFF00) >> 8; 249 dst += 2; 250 src++; 251 } 252 #else 253 memcpy(dst, src, len * 2); 254 #endif 255 } 256 257 /* fat/cache.c */ 258 extern void fat_cache_inval_inode(struct inode *inode); 259 extern int fat_get_cluster(struct inode *inode, int cluster, 260 int *fclus, int *dclus); 261 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 262 unsigned long *mapped_blocks, int create); 263 264 /* fat/dir.c */ 265 extern const struct file_operations fat_dir_operations; 266 extern int fat_search_long(struct inode *inode, const unsigned char *name, 267 int name_len, struct fat_slot_info *sinfo); 268 extern int fat_dir_empty(struct inode *dir); 269 extern int fat_subdirs(struct inode *dir); 270 extern int fat_scan(struct inode *dir, const unsigned char *name, 271 struct fat_slot_info *sinfo); 272 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 273 struct msdos_dir_entry **de); 274 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); 275 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 276 struct fat_slot_info *sinfo); 277 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); 278 279 /* fat/fatent.c */ 280 struct fat_entry { 281 int entry; 282 union { 283 u8 *ent12_p[2]; 284 __le16 *ent16_p; 285 __le32 *ent32_p; 286 } u; 287 int nr_bhs; 288 struct buffer_head *bhs[2]; 289 struct inode *fat_inode; 290 }; 291 292 static inline void fatent_init(struct fat_entry *fatent) 293 { 294 fatent->nr_bhs = 0; 295 fatent->entry = 0; 296 fatent->u.ent32_p = NULL; 297 fatent->bhs[0] = fatent->bhs[1] = NULL; 298 fatent->fat_inode = NULL; 299 } 300 301 static inline void fatent_set_entry(struct fat_entry *fatent, int entry) 302 { 303 fatent->entry = entry; 304 fatent->u.ent32_p = NULL; 305 } 306 307 static inline void fatent_brelse(struct fat_entry *fatent) 308 { 309 int i; 310 fatent->u.ent32_p = NULL; 311 for (i = 0; i < fatent->nr_bhs; i++) 312 brelse(fatent->bhs[i]); 313 fatent->nr_bhs = 0; 314 fatent->bhs[0] = fatent->bhs[1] = NULL; 315 fatent->fat_inode = NULL; 316 } 317 318 extern void fat_ent_access_init(struct super_block *sb); 319 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, 320 int entry); 321 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, 322 int new, int wait); 323 extern int fat_alloc_clusters(struct inode *inode, int *cluster, 324 int nr_cluster); 325 extern int fat_free_clusters(struct inode *inode, int cluster); 326 extern int fat_count_free_clusters(struct super_block *sb); 327 328 /* fat/file.c */ 329 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, 330 unsigned long arg); 331 extern const struct file_operations fat_file_operations; 332 extern const struct inode_operations fat_file_inode_operations; 333 extern int fat_setattr(struct dentry *dentry, struct iattr *attr); 334 extern void fat_truncate_blocks(struct inode *inode, loff_t offset); 335 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, 336 struct kstat *stat); 337 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, 338 int datasync); 339 340 /* fat/inode.c */ 341 extern void fat_attach(struct inode *inode, loff_t i_pos); 342 extern void fat_detach(struct inode *inode); 343 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); 344 extern struct inode *fat_build_inode(struct super_block *sb, 345 struct msdos_dir_entry *de, loff_t i_pos); 346 extern int fat_sync_inode(struct inode *inode); 347 extern int fat_fill_super(struct super_block *sb, void *data, int silent, 348 int isvfat, void (*setup)(struct super_block *)); 349 350 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, 351 struct inode *i2); 352 static inline unsigned long fat_dir_hash(int logstart) 353 { 354 return hash_32(logstart, FAT_HASH_BITS); 355 } 356 357 /* fat/misc.c */ 358 extern __printf(3, 4) __cold 359 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); 360 #define fat_fs_error(sb, fmt, args...) \ 361 __fat_fs_error(sb, 1, fmt , ## args) 362 #define fat_fs_error_ratelimit(sb, fmt, args...) \ 363 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) 364 __printf(3, 4) __cold 365 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); 366 #define fat_msg_ratelimit(sb, level, fmt, args...) \ 367 do { \ 368 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ 369 fat_msg(sb, level, fmt, ## args); \ 370 } while (0) 371 extern int fat_clusters_flush(struct super_block *sb); 372 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); 373 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, 374 __le16 __time, __le16 __date, u8 time_cs); 375 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, 376 __le16 *time, __le16 *date, u8 *time_cs); 377 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); 378 379 int fat_cache_init(void); 380 void fat_cache_destroy(void); 381 382 /* fat/nfs.c */ 383 struct fid; 384 extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, 385 int fh_len, int fh_type); 386 extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, 387 int fh_len, int fh_type); 388 extern struct dentry *fat_get_parent(struct dentry *child_dir); 389 390 /* helper for printk */ 391 typedef unsigned long long llu; 392 393 #endif /* !_FAT_H */ 394