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