fs/fat/fat.h

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