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/hash.h>
   9 #include <linux/mutex.h>
  10 #include <linux/ratelimit.h>
  11 #include <linux/msdos_fs.h>
  12
  13 /*
  14  * vfat shortname flags
  15  */
  16 #define VFAT_SFN_DISPLAY_LOWER  0x0001 /* convert to lowercase for display */
  17 #define VFAT_SFN_DISPLAY_WIN95  0x0002 /* emulate win95 rule for display */
  18 #define VFAT_SFN_DISPLAY_WINNT  0x0004 /* emulate winnt rule for display */
  19 #define VFAT_SFN_CREATE_WIN95   0x0100 /* emulate win95 rule for create */
  20 #define VFAT_SFN_CREATE_WINNT   0x0200 /* emulate winnt rule for create */
  21
  22 #define FAT_ERRORS_CONT         1      /* ignore error and continue */
  23 #define FAT_ERRORS_PANIC        2      /* panic on error */
  24 #define FAT_ERRORS_RO           3      /* remount r/o on error */
  25
  26 #define FAT_NFS_STALE_RW        1      /* NFS RW support, can cause ESTALE */
  27 #define FAT_NFS_NOSTALE_RO      2      /* NFS RO support, no ESTALE issue */
  28
  29 struct fat_mount_options {
  30         kuid_t fs_uid;
  31         kgid_t fs_gid;
  32         unsigned short fs_fmask;
  33         unsigned short fs_dmask;
  34         unsigned short codepage;   /* Codepage for shortname conversions */
  35         int time_offset;           /* Offset of timestamps from UTC (in minutes) */
  36         char *iocharset;           /* Charset used for filename input/display */
  37         unsigned short shortname;  /* flags for shortname display/create rule */
  38         unsigned char name_check;  /* r = relaxed, n = normal, s = strict */
  39         unsigned char errors;      /* On error: continue, panic, remount-ro */
  40         unsigned char nfs;        /* NFS support: nostale_ro, stale_rw */
  41         unsigned short allow_utime;/* permission for setting the [am]time */
  42         unsigned quiet:1,          /* set = fake successful chmods and chowns */
  43                  showexec:1,       /* set = only set x bit for com/exe/bat */
  44                  sys_immutable:1,  /* set = system files are immutable */
  45                  dotsOK:1,         /* set = hidden and system files are named '.filename' */
  46                  isvfat:1,         /* 0=no vfat long filename support, 1=vfat support */
  47                  utf8:1,           /* Use of UTF-8 character set (Default) */
  48                  unicode_xlate:1,  /* create escape sequences for unhandled Unicode */
  49                  numtail:1,        /* Does first alias have a numeric '~1' type tail? */
  50                  flush:1,          /* write things quickly */
  51                  nocase:1,         /* Does this need case conversion? 0=need case conversion*/
  52                  usefree:1,        /* Use free_clusters for FAT32 */
  53                  tz_set:1,         /* Filesystem timestamps' offset set */
  54                  rodir:1,          /* allow ATTR_RO for directory */
  55                  discard:1,        /* Issue discard requests on deletions */
  56                  dos1xfloppy:1;    /* Assume default BPB for DOS 1.x floppies */
  57 };
  58
  59 #define FAT_HASH_BITS   8
  60 #define FAT_HASH_SIZE   (1UL << FAT_HASH_BITS)
  61
  62 /*
  63  * MS-DOS file system in-core superblock data
  64  */
  65 struct msdos_sb_info {
  66         unsigned short sec_per_clus;  /* sectors/cluster */
  67         unsigned short cluster_bits;  /* log2(cluster_size) */
  68         unsigned int cluster_size;    /* cluster size */
  69         unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */
  70         unsigned short fat_start;
  71         unsigned long fat_length;     /* FAT start & length (sec.) */
  72         unsigned long dir_start;
  73         unsigned short dir_entries;   /* root dir start & entries */
  74         unsigned long data_start;     /* first data sector */
  75         unsigned long max_cluster;    /* maximum cluster number */
  76         unsigned long root_cluster;   /* first cluster of the root directory */
  77         unsigned long fsinfo_sector;  /* sector number of FAT32 fsinfo */
  78         struct mutex fat_lock;
  79         struct mutex nfs_build_inode_lock;
  80         struct mutex s_lock;
  81         unsigned int prev_free;      /* previously allocated cluster number */
  82         unsigned int free_clusters;  /* -1 if undefined */
  83         unsigned int free_clus_valid; /* is free_clusters valid? */
  84         struct fat_mount_options options;
  85         struct nls_table *nls_disk;   /* Codepage used on disk */
  86         struct nls_table *nls_io;     /* Charset used for input and display */
  87         const void *dir_ops;          /* Opaque; default directory operations */
  88         int dir_per_block;            /* dir entries per block */
  89         int dir_per_block_bits;       /* log2(dir_per_block) */
  90         unsigned int vol_id;            /*volume ID*/
  91
  92         int fatent_shift;
  93         struct fatent_operations *fatent_ops;
  94         struct inode *fat_inode;
  95         struct inode *fsinfo_inode;
  96
  97         struct ratelimit_state ratelimit;
  98
  99         spinlock_t inode_hash_lock;
 100         struct hlist_head inode_hashtable[FAT_HASH_SIZE];
 101
 102         spinlock_t dir_hash_lock;
 103         struct hlist_head dir_hashtable[FAT_HASH_SIZE];
 104
 105         unsigned int dirty;           /* fs state before mount */
 106         struct rcu_head rcu;
 107 };
 108
 109 #define FAT_CACHE_VALID 0       /* special case for valid cache */
 110
 111 /*
 112  * MS-DOS file system inode data in memory
 113  */
 114 struct msdos_inode_info {
 115         spinlock_t cache_lru_lock;
 116         struct list_head cache_lru;
 117         int nr_caches;
 118         /* for avoiding the race between fat_free() and fat_get_cluster() */
 119         unsigned int cache_valid_id;
 120
 121         /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
 122         loff_t mmu_private;     /* physically allocated size */
 123
 124         int i_start;            /* first cluster or 0 */
 125         int i_logstart;         /* logical first cluster */
 126         int i_attrs;            /* unused attribute bits */
 127         loff_t i_pos;           /* on-disk position of directory entry or 0 */
 128         struct hlist_node i_fat_hash;   /* hash by i_location */
 129         struct hlist_node i_dir_hash;   /* hash by i_logstart */
 130         struct rw_semaphore truncate_lock; /* protect bmap against truncate */
 131         struct inode vfs_inode;
 132 };
 133
 134 struct fat_slot_info {
 135         loff_t i_pos;           /* on-disk position of directory entry */
 136         loff_t slot_off;        /* offset for slot or de start */
 137         int nr_slots;           /* number of slots + 1(de) in filename */
 138         struct msdos_dir_entry *de;
 139         struct buffer_head *bh;
 140 };
 141
 142 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
 143 {
 144         return sb->s_fs_info;
 145 }
 146
 147 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
 148 {
 149         return container_of(inode, struct msdos_inode_info, vfs_inode);
 150 }
 151
 152 /*
 153  * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
 154  * save ATTR_RO instead of ->i_mode.
 155  *
 156  * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
 157  * bit, it's just used as flag for app.
 158  */
 159 static inline int fat_mode_can_hold_ro(struct inode *inode)
 160 {
 161         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 162         umode_t mask;
 163
 164         if (S_ISDIR(inode->i_mode)) {
 165                 if (!sbi->options.rodir)
 166                         return 0;
 167                 mask = ~sbi->options.fs_dmask;
 168         } else
 169                 mask = ~sbi->options.fs_fmask;
 170
 171         if (!(mask & S_IWUGO))
 172                 return 0;
 173         return 1;
 174 }
 175
 176 /* Convert attribute bits and a mask to the UNIX mode. */
 177 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
 178                                    u8 attrs, umode_t mode)
 179 {
 180         if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
 181                 mode &= ~S_IWUGO;
 182
 183         if (attrs & ATTR_DIR)
 184                 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
 185         else
 186                 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
 187 }
 188
 189 /* Return the FAT attribute byte for this inode */
 190 static inline u8 fat_make_attrs(struct inode *inode)
 191 {
 192         u8 attrs = MSDOS_I(inode)->i_attrs;
 193         if (S_ISDIR(inode->i_mode))
 194                 attrs |= ATTR_DIR;
 195         if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
 196                 attrs |= ATTR_RO;
 197         return attrs;
 198 }
 199
 200 static inline void fat_save_attrs(struct inode *inode, u8 attrs)
 201 {
 202         if (fat_mode_can_hold_ro(inode))
 203                 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
 204         else
 205                 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
 206 }
 207
 208 static inline unsigned char fat_checksum(const __u8 *name)
 209 {
 210         unsigned char s = name[0];
 211         s = (s<<7) + (s>>1) + name[1];  s = (s<<7) + (s>>1) + name[2];
 212         s = (s<<7) + (s>>1) + name[3];  s = (s<<7) + (s>>1) + name[4];
 213         s = (s<<7) + (s>>1) + name[5];  s = (s<<7) + (s>>1) + name[6];
 214         s = (s<<7) + (s>>1) + name[7];  s = (s<<7) + (s>>1) + name[8];
 215         s = (s<<7) + (s>>1) + name[9];  s = (s<<7) + (s>>1) + name[10];
 216         return s;
 217 }
 218
 219 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
 220 {
 221         return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
 222                 + sbi->data_start;
 223 }
 224
 225 static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
 226                                 loff_t i_pos, sector_t *blknr, int *offset)
 227 {
 228         *blknr = i_pos >> sbi->dir_per_block_bits;
 229         *offset = i_pos & (sbi->dir_per_block - 1);
 230 }
 231
 232 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
 233                                         struct inode *inode)
 234 {
 235         loff_t i_pos;
 236 #if BITS_PER_LONG == 32
 237         spin_lock(&sbi->inode_hash_lock);
 238 #endif
 239         i_pos = MSDOS_I(inode)->i_pos;
 240 #if BITS_PER_LONG == 32
 241         spin_unlock(&sbi->inode_hash_lock);
 242 #endif
 243         return i_pos;
 244 }
 245
 246 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
 247 {
 248 #ifdef __BIG_ENDIAN
 249         while (len--) {
 250                 *dst++ = src[0] | (src[1] << 8);
 251                 src += 2;
 252         }
 253 #else
 254         memcpy(dst, src, len * 2);
 255 #endif
 256 }
 257
 258 static inline int fat_get_start(const struct msdos_sb_info *sbi,
 259                                 const struct msdos_dir_entry *de)
 260 {
 261         int cluster = le16_to_cpu(de->start);
 262         if (sbi->fat_bits == 32)
 263                 cluster |= (le16_to_cpu(de->starthi) << 16);
 264         return cluster;
 265 }
 266
 267 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
 268 {
 269         de->start   = cpu_to_le16(cluster);
 270         de->starthi = cpu_to_le16(cluster >> 16);
 271 }
 272
 273 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
 274 {
 275 #ifdef __BIG_ENDIAN
 276         while (len--) {
 277                 dst[0] = *src & 0x00FF;
 278                 dst[1] = (*src & 0xFF00) >> 8;
 279                 dst += 2;
 280                 src++;
 281         }
 282 #else
 283         memcpy(dst, src, len * 2);
 284 #endif
 285 }
 286
 287 /* fat/cache.c */
 288 extern void fat_cache_inval_inode(struct inode *inode);
 289 extern int fat_get_cluster(struct inode *inode, int cluster,
 290                            int *fclus, int *dclus);
 291 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
 292                     unsigned long *mapped_blocks, int create);
 293
 294 /* fat/dir.c */
 295 extern const struct file_operations fat_dir_operations;
 296 extern int fat_search_long(struct inode *inode, const unsigned char *name,
 297                            int name_len, struct fat_slot_info *sinfo);
 298 extern int fat_dir_empty(struct inode *dir);
 299 extern int fat_subdirs(struct inode *dir);
 300 extern int fat_scan(struct inode *dir, const unsigned char *name,
 301                     struct fat_slot_info *sinfo);
 302 extern int fat_scan_logstart(struct inode *dir, int i_logstart,
 303                              struct fat_slot_info *sinfo);
 304 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 305                                 struct msdos_dir_entry **de);
 306 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
 307 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
 308                            struct fat_slot_info *sinfo);
 309 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
 310
 311 /* fat/fatent.c */
 312 struct fat_entry {
 313         int entry;
 314         union {
 315                 u8 *ent12_p[2];
 316                 __le16 *ent16_p;
 317                 __le32 *ent32_p;
 318         } u;
 319         int nr_bhs;
 320         struct buffer_head *bhs[2];
 321         struct inode *fat_inode;
 322 };
 323
 324 static inline void fatent_init(struct fat_entry *fatent)
 325 {
 326         fatent->nr_bhs = 0;
 327         fatent->entry = 0;
 328         fatent->u.ent32_p = NULL;
 329         fatent->bhs[0] = fatent->bhs[1] = NULL;
 330         fatent->fat_inode = NULL;
 331 }
 332
 333 static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
 334 {
 335         fatent->entry = entry;
 336         fatent->u.ent32_p = NULL;
 337 }
 338
 339 static inline void fatent_brelse(struct fat_entry *fatent)
 340 {
 341         int i;
 342         fatent->u.ent32_p = NULL;
 343         for (i = 0; i < fatent->nr_bhs; i++)
 344                 brelse(fatent->bhs[i]);
 345         fatent->nr_bhs = 0;
 346         fatent->bhs[0] = fatent->bhs[1] = NULL;
 347         fatent->fat_inode = NULL;
 348 }
 349
 350 extern void fat_ent_access_init(struct super_block *sb);
 351 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
 352                         int entry);
 353 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
 354                          int new, int wait);
 355 extern int fat_alloc_clusters(struct inode *inode, int *cluster,
 356                               int nr_cluster);
 357 extern int fat_free_clusters(struct inode *inode, int cluster);
 358 extern int fat_count_free_clusters(struct super_block *sb);
 359
 360 /* fat/file.c */
 361 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
 362                               unsigned long arg);
 363 extern const struct file_operations fat_file_operations;
 364 extern const struct inode_operations fat_file_inode_operations;
 365 extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
 366 extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
 367 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
 368                        struct kstat *stat);
 369 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
 370                           int datasync);
 371
 372 /* fat/inode.c */
 373 extern void fat_attach(struct inode *inode, loff_t i_pos);
 374 extern void fat_detach(struct inode *inode);
 375 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
 376 extern struct inode *fat_build_inode(struct super_block *sb,
 377                         struct msdos_dir_entry *de, loff_t i_pos);
 378 extern int fat_sync_inode(struct inode *inode);
 379 extern int fat_fill_super(struct super_block *sb, void *data, int silent,
 380                           int isvfat, void (*setup)(struct super_block *));
 381 extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
 382
 383 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
 384                             struct inode *i2);
 385 static inline unsigned long fat_dir_hash(int logstart)
 386 {
 387         return hash_32(logstart, FAT_HASH_BITS);
 388 }
 389
 390 /* fat/misc.c */
 391 extern __printf(3, 4) __cold
 392 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
 393 #define fat_fs_error(sb, fmt, args...)          \
 394         __fat_fs_error(sb, 1, fmt , ## args)
 395 #define fat_fs_error_ratelimit(sb, fmt, args...) \
 396         __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
 397 __printf(3, 4) __cold
 398 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
 399 #define fat_msg_ratelimit(sb, level, fmt, args...)      \
 400         do {    \
 401                         if (__ratelimit(&MSDOS_SB(sb)->ratelimit))      \
 402                                 fat_msg(sb, level, fmt, ## args);       \
 403          } while (0)
 404 extern int fat_clusters_flush(struct super_block *sb);
 405 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
 406 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
 407                               __le16 __time, __le16 __date, u8 time_cs);
 408 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
 409                               __le16 *time, __le16 *date, u8 *time_cs);
 410 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
 411
 412 int fat_cache_init(void);
 413 void fat_cache_destroy(void);
 414
 415 /* fat/nfs.c */
 416 extern const struct export_operations fat_export_ops;
 417 extern const struct export_operations fat_export_ops_nostale;
 418
 419 /* helper for printk */
 420 typedef unsigned long long      llu;
 421
 422 #endif /* !_FAT_H */