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