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