include/linux/msdos_fs.h

   1 #ifndef _LINUX_MSDOS_FS_H
   2 #define _LINUX_MSDOS_FS_H
   3
   4 /*
   5  * The MS-DOS filesystem constants/structures
   6  */
   7 #include <asm/byteorder.h>
   8
   9 #define SECTOR_SIZE     512             /* sector size (bytes) */
  10 #define SECTOR_BITS     9               /* log2(SECTOR_SIZE) */
  11 #define MSDOS_DPB       (MSDOS_DPS)     /* dir entries per block */
  12 #define MSDOS_DPB_BITS  4               /* log2(MSDOS_DPB) */
  13 #define MSDOS_DPS       (SECTOR_SIZE / sizeof(struct msdos_dir_entry))
  14 #define MSDOS_DPS_BITS  4               /* log2(MSDOS_DPS) */
  15
  16
  17 #define MSDOS_SUPER_MAGIC 0x4d44 /* MD */
  18
  19 #define MSDOS_ROOT_INO  1       /* == MINIX_ROOT_INO */
  20 #define MSDOS_DIR_BITS  5       /* log2(sizeof(struct msdos_dir_entry)) */
  21
  22 /* directory limit */
  23 #define FAT_MAX_DIR_ENTRIES     (65536)
  24 #define FAT_MAX_DIR_SIZE        (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)
  25
  26 #define ATTR_NONE    0 /* no attribute bits */
  27 #define ATTR_RO      1  /* read-only */
  28 #define ATTR_HIDDEN  2  /* hidden */
  29 #define ATTR_SYS     4  /* system */
  30 #define ATTR_VOLUME  8  /* volume label */
  31 #define ATTR_DIR     16 /* directory */
  32 #define ATTR_ARCH    32 /* archived */
  33
  34 /* attribute bits that are copied "as is" */
  35 #define ATTR_UNUSED  (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
  36 /* bits that are used by the Windows 95/Windows NT extended FAT */
  37 #define ATTR_EXT     (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
  38
  39 #define CASE_LOWER_BASE 8       /* base is lower case */
  40 #define CASE_LOWER_EXT  16      /* extension is lower case */
  41
  42 #define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */
  43 #define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG)
  44
  45 /* valid file mode bits */
  46 #define MSDOS_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO)
  47 /* Convert attribute bits and a mask to the UNIX mode. */
  48 #define MSDOS_MKMODE(a, m) (m & (a & ATTR_RO ? S_IRUGO|S_IXUGO : S_IRWXUGO))
  49 /* Convert the UNIX mode to MS-DOS attribute bits. */
  50 #define MSDOS_MKATTR(m) ((m & S_IWUGO) ? ATTR_NONE : ATTR_RO)
  51
  52 #define MSDOS_NAME 11 /* maximum name length */
  53 #define MSDOS_LONGNAME 256 /* maximum name length */
  54 #define MSDOS_SLOTS 21  /* max # of slots needed for short and long names */
  55 #define MSDOS_DOT    ".          " /* ".", padded to MSDOS_NAME chars */
  56 #define MSDOS_DOTDOT "..         " /* "..", padded to MSDOS_NAME chars */
  57
  58 /* media of boot sector */
  59 #define FAT_VALID_MEDIA(x)      ((0xF8 <= (x) && (x) <= 0xFF) || (x) == 0xF0)
  60 #define FAT_FIRST_ENT(s, x)     ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
  61         MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
  62
  63 /* maximum number of clusters */
  64 #define MAX_FAT12 0xFF4
  65 #define MAX_FAT16 0xFFF4
  66 #define MAX_FAT32 0x0FFFFFF6
  67 #define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
  68         MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
  69
  70 /* bad cluster mark */
  71 #define BAD_FAT12 0xFF7
  72 #define BAD_FAT16 0xFFF7
  73 #define BAD_FAT32 0x0FFFFFF7
  74 #define BAD_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? BAD_FAT32 : \
  75         MSDOS_SB(s)->fat_bits == 16 ? BAD_FAT16 : BAD_FAT12)
  76
  77 /* standard EOF */
  78 #define EOF_FAT12 0xFFF
  79 #define EOF_FAT16 0xFFFF
  80 #define EOF_FAT32 0x0FFFFFFF
  81 #define EOF_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? EOF_FAT32 : \
  82         MSDOS_SB(s)->fat_bits == 16 ? EOF_FAT16 : EOF_FAT12)
  83
  84 #define FAT_ENT_FREE    (0)
  85 #define FAT_ENT_BAD     (BAD_FAT32)
  86 #define FAT_ENT_EOF     (EOF_FAT32)
  87
  88 #define FAT_FSINFO_SIG1 0x41615252
  89 #define FAT_FSINFO_SIG2 0x61417272
  90 #define IS_FSINFO(x)    (CF_LE_L((x)->signature1) == FAT_FSINFO_SIG1    \
  91                          && CF_LE_L((x)->signature2) == FAT_FSINFO_SIG2)
  92
  93 /*
  94  * ioctl commands
  95  */
  96 #define VFAT_IOCTL_READDIR_BOTH         _IOR('r', 1, struct dirent [2])
  97 #define VFAT_IOCTL_READDIR_SHORT        _IOR('r', 2, struct dirent [2])
  98
  99 /*
 100  * vfat shortname flags
 101  */
 102 #define VFAT_SFN_DISPLAY_LOWER  0x0001 /* convert to lowercase for display */
 103 #define VFAT_SFN_DISPLAY_WIN95  0x0002 /* emulate win95 rule for display */
 104 #define VFAT_SFN_DISPLAY_WINNT  0x0004 /* emulate winnt rule for display */
 105 #define VFAT_SFN_CREATE_WIN95   0x0100 /* emulate win95 rule for create */
 106 #define VFAT_SFN_CREATE_WINNT   0x0200 /* emulate winnt rule for create */
 107
 108 /*
 109  * Conversion from and to little-endian byte order. (no-op on i386/i486)
 110  *
 111  * Naming: Ca_b_c, where a: F = from, T = to, b: LE = little-endian,
 112  * BE = big-endian, c: W = word (16 bits), L = longword (32 bits)
 113  */
 114
 115 #define CF_LE_W(v) le16_to_cpu(v)
 116 #define CF_LE_L(v) le32_to_cpu(v)
 117 #define CT_LE_W(v) cpu_to_le16(v)
 118 #define CT_LE_L(v) cpu_to_le32(v)
 119
 120 struct fat_boot_sector {
 121         __u8    ignored[3];     /* Boot strap short or near jump */
 122         __u8    system_id[8];   /* Name - can be used to special case
 123                                    partition manager volumes */
 124         __u8    sector_size[2]; /* bytes per logical sector */
 125         __u8    sec_per_clus;   /* sectors/cluster */
 126         __le16  reserved;       /* reserved sectors */
 127         __u8    fats;           /* number of FATs */
 128         __u8    dir_entries[2]; /* root directory entries */
 129         __u8    sectors[2];     /* number of sectors */
 130         __u8    media;          /* media code */
 131         __le16  fat_length;     /* sectors/FAT */
 132         __le16  secs_track;     /* sectors per track */
 133         __le16  heads;          /* number of heads */
 134         __le32  hidden;         /* hidden sectors (unused) */
 135         __le32  total_sect;     /* number of sectors (if sectors == 0) */
 136
 137         /* The following fields are only used by FAT32 */
 138         __le32  fat32_length;   /* sectors/FAT */
 139         __le16  flags;          /* bit 8: fat mirroring, low 4: active fat */
 140         __u8    version[2];     /* major, minor filesystem version */
 141         __le32  root_cluster;   /* first cluster in root directory */
 142         __le16  info_sector;    /* filesystem info sector */
 143         __le16  backup_boot;    /* backup boot sector */
 144         __le16  reserved2[6];   /* Unused */
 145 };
 146
 147 struct fat_boot_fsinfo {
 148         __le32   signature1;    /* 0x41615252L */
 149         __le32   reserved1[120];        /* Nothing as far as I can tell */
 150         __le32   signature2;    /* 0x61417272L */
 151         __le32   free_clusters; /* Free cluster count.  -1 if unknown */
 152         __le32   next_cluster;  /* Most recently allocated cluster */
 153         __le32   reserved2[4];
 154 };
 155
 156 struct msdos_dir_entry {
 157         __u8    name[8],ext[3]; /* name and extension */
 158         __u8    attr;           /* attribute bits */
 159         __u8    lcase;          /* Case for base and extension */
 160         __u8    ctime_ms;       /* Creation time, milliseconds */
 161         __le16  ctime;          /* Creation time */
 162         __le16  cdate;          /* Creation date */
 163         __le16  adate;          /* Last access date */
 164         __le16   starthi;       /* High 16 bits of cluster in FAT32 */
 165         __le16  time,date,start;/* time, date and first cluster */
 166         __le32  size;           /* file size (in bytes) */
 167 };
 168
 169 /* Up to 13 characters of the name */
 170 struct msdos_dir_slot {
 171         __u8    id;             /* sequence number for slot */
 172         __u8    name0_4[10];    /* first 5 characters in name */
 173         __u8    attr;           /* attribute byte */
 174         __u8    reserved;       /* always 0 */
 175         __u8    alias_checksum; /* checksum for 8.3 alias */
 176         __u8    name5_10[12];   /* 6 more characters in name */
 177         __le16   start;         /* starting cluster number, 0 in long slots */
 178         __u8    name11_12[4];   /* last 2 characters in name */
 179 };
 180
 181 struct vfat_slot_info {
 182         int long_slots;                /* number of long slots in filename */
 183         loff_t longname_offset;        /* dir offset for longname start */
 184         loff_t i_pos;                  /* on-disk position of directory entry */
 185 };
 186
 187 #ifdef __KERNEL__
 188
 189 #include <linux/buffer_head.h>
 190 #include <linux/string.h>
 191 #include <linux/nls.h>
 192 #include <linux/msdos_fs_i.h>
 193 #include <linux/msdos_fs_sb.h>
 194
 195 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
 196 {
 197         return sb->s_fs_info;
 198 }
 199
 200 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
 201 {
 202         return container_of(inode, struct msdos_inode_info, vfs_inode);
 203 }
 204
 205 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
 206 {
 207 #ifdef __BIG_ENDIAN
 208         while (len--) {
 209                 *dst++ = src[0] | (src[1] << 8);
 210                 src += 2;
 211         }
 212 #else
 213         memcpy(dst, src, len * 2);
 214 #endif
 215 }
 216
 217 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
 218 {
 219 #ifdef __BIG_ENDIAN
 220         while (len--) {
 221                 dst[0] = *src & 0x00FF;
 222                 dst[1] = (*src & 0xFF00) >> 8;
 223                 dst += 2;
 224                 src++;
 225         }
 226 #else
 227         memcpy(dst, src, len * 2);
 228 #endif
 229 }
 230
 231 /* fat/cache.c */
 232 extern int fat_access(struct super_block *sb, int nr, int new_value);
 233 extern int __fat_access(struct super_block *sb, int nr, int new_value);
 234 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys);
 235 extern void fat_cache_init(struct super_block *sb);
 236 extern void fat_cache_add(struct inode *inode, int f_clu, int d_clu);
 237 extern void fat_cache_inval_inode(struct inode *inode);
 238 extern int fat_get_cluster(struct inode *inode, int cluster,
 239                            int *fclus, int *dclus);
 240 extern int fat_free(struct inode *inode, int skip);
 241
 242 /* fat/dir.c */
 243 extern struct file_operations fat_dir_operations;
 244 extern int fat_search_long(struct inode *inode, const unsigned char *name,
 245                            int name_len, int anycase,
 246                            loff_t *spos, loff_t *lpos);
 247 extern int fat_readdir(struct file *filp, void *dirent, filldir_t filldir);
 248 extern int fat_dir_ioctl(struct inode * inode, struct file * filp,
 249                          unsigned int cmd, unsigned long arg);
 250 extern int fat_add_entries(struct inode *dir, int slots, struct buffer_head **bh,
 251                         struct msdos_dir_entry **de, loff_t *i_pos);
 252 extern int fat_new_dir(struct inode *dir, struct inode *parent, int is_vfat);
 253 extern int fat_dir_empty(struct inode *dir);
 254 extern int fat_subdirs(struct inode *dir);
 255 extern int fat_scan(struct inode *dir, const unsigned char *name,
 256                     struct buffer_head **res_bh,
 257                     struct msdos_dir_entry **res_de, loff_t *i_pos);
 258
 259 /* fat/file.c */
 260 extern struct file_operations fat_file_operations;
 261 extern struct inode_operations fat_file_inode_operations;
 262 extern int fat_get_block(struct inode *inode, sector_t iblock,
 263                          struct buffer_head *bh_result, int create);
 264 extern void fat_truncate(struct inode *inode);
 265
 266 /* fat/inode.c */
 267 extern void fat_hash_init(void);
 268 extern void fat_attach(struct inode *inode, loff_t i_pos);
 269 extern void fat_detach(struct inode *inode);
 270 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
 271 extern struct inode *fat_build_inode(struct super_block *sb,
 272                         struct msdos_dir_entry *de, loff_t i_pos, int *res);
 273 extern void fat_delete_inode(struct inode *inode);
 274 extern void fat_clear_inode(struct inode *inode);
 275 extern void fat_put_super(struct super_block *sb);
 276 int fat_fill_super(struct super_block *sb, void *data, int silent,
 277                    struct inode_operations *fs_dir_inode_ops, int isvfat);
 278 extern int fat_statfs(struct super_block *sb, struct kstatfs *buf);
 279 extern int fat_write_inode(struct inode *inode, int wait);
 280 extern int fat_notify_change(struct dentry * dentry, struct iattr * attr);
 281
 282 /* fat/misc.c */
 283 extern void fat_fs_panic(struct super_block *s, const char *fmt, ...);
 284 extern void lock_fat(struct super_block *sb);
 285 extern void unlock_fat(struct super_block *sb);
 286 extern void fat_clusters_flush(struct super_block *sb);
 287 extern int fat_add_cluster(struct inode *inode);
 288 extern struct buffer_head *fat_extend_dir(struct inode *inode);
 289 extern int date_dos2unix(unsigned short time, unsigned short date);
 290 extern void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date);
 291 extern int fat__get_entry(struct inode *dir, loff_t *pos,
 292                           struct buffer_head **bh,
 293                           struct msdos_dir_entry **de, loff_t *i_pos);
 294 static __inline__ int fat_get_entry(struct inode *dir, loff_t *pos,
 295                                     struct buffer_head **bh,
 296                                     struct msdos_dir_entry **de, loff_t *i_pos)
 297 {
 298         /* Fast stuff first */
 299         if (*bh && *de &&
 300             (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
 301                 *pos += sizeof(struct msdos_dir_entry);
 302                 (*de)++;
 303                 (*i_pos)++;
 304                 return 0;
 305         }
 306         return fat__get_entry(dir, pos, bh, de, i_pos);
 307 }
 308
 309 #endif /* __KERNEL__ */
 310
 311 #endif