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/ratelimit.h>
  10 #include <linux/msdos_fs.h>
  11
  12 /*
  13  * vfat shortname flags
  14  */
  15 #define VFAT_SFN_DISPLAY_LOWER  0x0001 /* convert to lowercase for display */
  16 #define VFAT_SFN_DISPLAY_WIN95  0x0002 /* emulate win95 rule for display */
  17 #define VFAT_SFN_DISPLAY_WINNT  0x0004 /* emulate winnt rule for display */
  18 #define VFAT_SFN_CREATE_WIN95   0x0100 /* emulate win95 rule for create */
  19 #define VFAT_SFN_CREATE_WINNT   0x0200 /* emulate winnt rule for create */
  20
  21 #define FAT_ERRORS_CONT         1      /* ignore error and continue */
  22 #define FAT_ERRORS_PANIC        2      /* panic on error */
  23 #define FAT_ERRORS_RO           3      /* remount r/o on error */
  24
  25 struct fat_mount_options {
  26         uid_t fs_uid;
  27         gid_t fs_gid;
  28         unsigned short fs_fmask;
  29         unsigned short fs_dmask;
  30         unsigned short codepage;  /* Codepage for shortname conversions */
  31         char *iocharset;          /* Charset used for filename input/display */
  32         unsigned short shortname; /* flags for shortname display/create rule */
  33         unsigned char name_check; /* r = relaxed, n = normal, s = strict */
  34         unsigned char errors;     /* On error: continue, panic, remount-ro */
  35         unsigned short allow_utime;/* permission for setting the [am]time */
  36         unsigned quiet:1,         /* set = fake successful chmods and chowns */
  37                  showexec:1,      /* set = only set x bit for com/exe/bat */
  38                  sys_immutable:1, /* set = system files are immutable */
  39                  dotsOK:1,        /* set = hidden and system files are named '.filename' */
  40                  isvfat:1,        /* 0=no vfat long filename support, 1=vfat support */
  41                  utf8:1,          /* Use of UTF-8 character set (Default) */
  42                  unicode_xlate:1, /* create escape sequences for unhandled Unicode */
  43                  numtail:1,       /* Does first alias have a numeric '~1' type tail? */
  44                  flush:1,         /* write things quickly */
  45                  nocase:1,        /* Does this need case conversion? 0=need case conversion*/
  46                  usefree:1,       /* Use free_clusters for FAT32 */
  47                  tz_utc:1,        /* Filesystem timestamps are in UTC */
  48                  rodir:1,         /* allow ATTR_RO for directory */
  49                  discard:1;       /* Issue discard requests on deletions */
  50 };
  51
  52 #define FAT_HASH_BITS   8
  53 #define FAT_HASH_SIZE   (1UL << FAT_HASH_BITS)
  54
  55 /*
  56  * MS-DOS file system in-core superblock data
  57  */
  58 struct msdos_sb_info {
  59         unsigned short sec_per_clus; /* sectors/cluster */
  60         unsigned short cluster_bits; /* log2(cluster_size) */
  61         unsigned int cluster_size;   /* cluster size */
  62         unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
  63         unsigned short fat_start;
  64         unsigned long fat_length;    /* FAT start & length (sec.) */
  65         unsigned long dir_start;
  66         unsigned short dir_entries;  /* root dir start & entries */
  67         unsigned long data_start;    /* first data sector */
  68         unsigned long max_cluster;   /* maximum cluster number */
  69         unsigned long root_cluster;  /* first cluster of the root directory */
  70         unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
  71         struct mutex fat_lock;
  72         unsigned int prev_free;      /* previously allocated cluster number */
  73         unsigned int free_clusters;  /* -1 if undefined */
  74         unsigned int free_clus_valid; /* is free_clusters valid? */
  75         struct fat_mount_options options;
  76         struct nls_table *nls_disk;  /* Codepage used on disk */
  77         struct nls_table *nls_io;    /* Charset used for input and display */
  78         const void *dir_ops;                 /* Opaque; default directory operations */
  79         int dir_per_block;           /* dir entries per block */
  80         int dir_per_block_bits;      /* log2(dir_per_block) */
  81
  82         int fatent_shift;
  83         struct fatent_operations *fatent_ops;
  84         struct inode *fat_inode;
  85         struct inode *fsinfo_inode;
  86
  87         struct ratelimit_state ratelimit;
  88
  89         spinlock_t inode_hash_lock;
  90         struct hlist_head inode_hashtable[FAT_HASH_SIZE];
  91 };
  92
  93 #define FAT_CACHE_VALID 0       /* special case for valid cache */
  94
  95 /*
  96  * MS-DOS file system inode data in memory
  97  */
  98 struct msdos_inode_info {
  99         spinlock_t cache_lru_lock;
 100         struct list_head cache_lru;
 101         int nr_caches;
 102         /* for avoiding the race between fat_free() and fat_get_cluster() */
 103         unsigned int cache_valid_id;
 104
 105         /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
 106         loff_t mmu_private;     /* physically allocated size */
 107
 108         int i_start;            /* first cluster or 0 */
 109         int i_logstart;         /* logical first cluster */
 110         int i_attrs;            /* unused attribute bits */
 111         loff_t i_pos;           /* on-disk position of directory entry or 0 */
 112         struct hlist_node i_fat_hash;   /* hash by i_location */
 113         struct rw_semaphore truncate_lock; /* protect bmap against truncate */
 114         struct inode vfs_inode;
 115 };
 116
 117 struct fat_slot_info {
 118         loff_t i_pos;           /* on-disk position of directory entry */
 119         loff_t slot_off;        /* offset for slot or de start */
 120         int nr_slots;           /* number of slots + 1(de) in filename */
 121         struct msdos_dir_entry *de;
 122         struct buffer_head *bh;
 123 };
 124
 125 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
 126 {
 127         return sb->s_fs_info;
 128 }
 129
 130 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
 131 {
 132         return container_of(inode, struct msdos_inode_info, vfs_inode);
 133 }
 134
 135 /*
 136  * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
 137  * save ATTR_RO instead of ->i_mode.
 138  *
 139  * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
 140  * bit, it's just used as flag for app.
 141  */
 142 static inline int fat_mode_can_hold_ro(struct inode *inode)
 143 {
 144         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 145         umode_t mask;
 146
 147         if (S_ISDIR(inode->i_mode)) {
 148                 if (!sbi->options.rodir)
 149                         return 0;
 150                 mask = ~sbi->options.fs_dmask;
 151         } else
 152                 mask = ~sbi->options.fs_fmask;
 153
 154         if (!(mask & S_IWUGO))
 155                 return 0;
 156         return 1;
 157 }
 158
 159 /* Convert attribute bits and a mask to the UNIX mode. */
 160 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
 161                                    u8 attrs, umode_t mode)
 162 {
 163         if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
 164                 mode &= ~S_IWUGO;
 165
 166         if (attrs & ATTR_DIR)
 167                 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
 168         else
 169                 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
 170 }
 171
 172 /* Return the FAT attribute byte for this inode */
 173 static inline u8 fat_make_attrs(struct inode *inode)
 174 {
 175         u8 attrs = MSDOS_I(inode)->i_attrs;
 176         if (S_ISDIR(inode->i_mode))
 177                 attrs |= ATTR_DIR;
 178         if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
 179                 attrs |= ATTR_RO;
 180         return attrs;
 181 }
 182
 183 static inline void fat_save_attrs(struct inode *inode, u8 attrs)
 184 {
 185         if (fat_mode_can_hold_ro(inode))
 186                 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
 187         else
 188                 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
 189 }
 190
 191 static inline unsigned char fat_checksum(const __u8 *name)
 192 {
 193         unsigned char s = name[0];
 194         s = (s<<7) + (s>>1) + name[1];  s = (s<<7) + (s>>1) + name[2];
 195         s = (s<<7) + (s>>1) + name[3];  s = (s<<7) + (s>>1) + name[4];
 196         s = (s<<7) + (s>>1) + name[5];  s = (s<<7) + (s>>1) + name[6];
 197         s = (s<<7) + (s>>1) + name[7];  s = (s<<7) + (s>>1) + name[8];
 198         s = (s<<7) + (s>>1) + name[9];  s = (s<<7) + (s>>1) + name[10];
 199         return s;
 200 }
 201
 202 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
 203 {
 204         return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
 205                 + sbi->data_start;
 206 }
 207
 208 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
 209 {
 210 #ifdef __BIG_ENDIAN
 211         while (len--) {
 212                 *dst++ = src[0] | (src[1] << 8);
 213                 src += 2;
 214         }
 215 #else
 216         memcpy(dst, src, len * 2);
 217 #endif
 218 }
 219
 220 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
 221 {
 222 #ifdef __BIG_ENDIAN
 223         while (len--) {
 224                 dst[0] = *src & 0x00FF;
 225                 dst[1] = (*src & 0xFF00) >> 8;
 226                 dst += 2;
 227                 src++;
 228         }
 229 #else
 230         memcpy(dst, src, len * 2);
 231 #endif
 232 }
 233
 234 /* fat/cache.c */
 235 extern void fat_cache_inval_inode(struct inode *inode);
 236 extern int fat_get_cluster(struct inode *inode, int cluster,
 237                            int *fclus, int *dclus);
 238 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
 239                     unsigned long *mapped_blocks, int create);
 240
 241 /* fat/dir.c */
 242 extern const struct file_operations fat_dir_operations;
 243 extern int fat_search_long(struct inode *inode, const unsigned char *name,
 244                            int name_len, struct fat_slot_info *sinfo);
 245 extern int fat_dir_empty(struct inode *dir);
 246 extern int fat_subdirs(struct inode *dir);
 247 extern int fat_scan(struct inode *dir, const unsigned char *name,
 248                     struct fat_slot_info *sinfo);
 249 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 250                                 struct msdos_dir_entry **de, loff_t *i_pos);
 251 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
 252 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
 253                            struct fat_slot_info *sinfo);
 254 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
 255
 256 /* fat/fatent.c */
 257 struct fat_entry {
 258         int entry;
 259         union {
 260                 u8 *ent12_p[2];
 261                 __le16 *ent16_p;
 262                 __le32 *ent32_p;
 263         } u;
 264         int nr_bhs;
 265         struct buffer_head *bhs[2];
 266         struct inode *fat_inode;
 267 };
 268
 269 static inline void fatent_init(struct fat_entry *fatent)
 270 {
 271         fatent->nr_bhs = 0;
 272         fatent->entry = 0;
 273         fatent->u.ent32_p = NULL;
 274         fatent->bhs[0] = fatent->bhs[1] = NULL;
 275         fatent->fat_inode = NULL;
 276 }
 277
 278 static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
 279 {
 280         fatent->entry = entry;
 281         fatent->u.ent32_p = NULL;
 282 }
 283
 284 static inline void fatent_brelse(struct fat_entry *fatent)
 285 {
 286         int i;
 287         fatent->u.ent32_p = NULL;
 288         for (i = 0; i < fatent->nr_bhs; i++)
 289                 brelse(fatent->bhs[i]);
 290         fatent->nr_bhs = 0;
 291         fatent->bhs[0] = fatent->bhs[1] = NULL;
 292         fatent->fat_inode = NULL;
 293 }
 294
 295 extern void fat_ent_access_init(struct super_block *sb);
 296 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
 297                         int entry);
 298 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
 299                          int new, int wait);
 300 extern int fat_alloc_clusters(struct inode *inode, int *cluster,
 301                               int nr_cluster);
 302 extern int fat_free_clusters(struct inode *inode, int cluster);
 303 extern int fat_count_free_clusters(struct super_block *sb);
 304
 305 /* fat/file.c */
 306 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
 307                               unsigned long arg);
 308 extern const struct file_operations fat_file_operations;
 309 extern const struct inode_operations fat_file_inode_operations;
 310 extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
 311 extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
 312 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
 313                        struct kstat *stat);
 314 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
 315                           int datasync);
 316
 317 /* fat/inode.c */
 318 extern void fat_attach(struct inode *inode, loff_t i_pos);
 319 extern void fat_detach(struct inode *inode);
 320 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
 321 extern struct inode *fat_build_inode(struct super_block *sb,
 322                         struct msdos_dir_entry *de, loff_t i_pos);
 323 extern int fat_sync_inode(struct inode *inode);
 324 extern int fat_fill_super(struct super_block *sb, void *data, int silent,
 325                           int isvfat, void (*setup)(struct super_block *));
 326
 327 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
 328                             struct inode *i2);
 329 /* fat/misc.c */
 330 extern __printf(3, 4) __cold
 331 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
 332 #define fat_fs_error(sb, fmt, args...)          \
 333         __fat_fs_error(sb, 1, fmt , ## args)
 334 #define fat_fs_error_ratelimit(sb, fmt, args...) \
 335         __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
 336 __printf(3, 4) __cold
 337 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
 338 #define fat_msg_ratelimit(sb, level, fmt, args...)      \
 339         do {    \
 340                         if (__ratelimit(&MSDOS_SB(sb)->ratelimit))      \
 341                                 fat_msg(sb, level, fmt, ## args);       \
 342          } while (0)
 343 extern int fat_clusters_flush(struct super_block *sb);
 344 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
 345 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
 346                               __le16 __time, __le16 __date, u8 time_cs);
 347 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
 348                               __le16 *time, __le16 *date, u8 *time_cs);
 349 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
 350
 351 int fat_cache_init(void);
 352 void fat_cache_destroy(void);
 353
 354 /* helper for printk */
 355 typedef unsigned long long      llu;
 356
 357 #endif /* !_FAT_H */