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