LXR linux/fs/fat/fat.h

   1#ifndef _FAT_H
   2#define _FAT_H
   3
   4#include <linux/buffer_head.h>
   5#include <linux/nls.h>
   6#include <linux/hash.h>
   7#include <linux/ratelimit.h>
   8#include <linux/msdos_fs.h>
   9
  10/*
  11 * vfat shortname flags
  12 */
  13#define VFAT_SFN_DISPLAY_LOWER  0x0001 /* convert to lowercase for display */
  14#define VFAT_SFN_DISPLAY_WIN95  0x0002 /* emulate win95 rule for display */
  15#define VFAT_SFN_DISPLAY_WINNT  0x0004 /* emulate winnt rule for display */
  16#define VFAT_SFN_CREATE_WIN95   0x0100 /* emulate win95 rule for create */
  17#define VFAT_SFN_CREATE_WINNT   0x0200 /* emulate winnt rule for create */
  18
  19#define FAT_ERRORS_CONT         1      /* ignore error and continue */
  20#define FAT_ERRORS_PANIC        2      /* panic on error */
  21#define FAT_ERRORS_RO           3      /* remount r/o on error */
  22
  23#define FAT_NFS_STALE_RW        1      /* NFS RW support, can cause ESTALE */
  24#define FAT_NFS_NOSTALE_RO      2      /* NFS RO support, no ESTALE issue */
  25
  26struct 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 char nfs;        /* NFS support: nostale_ro, stale_rw */
  38        unsigned short allow_utime;/* permission for setting the [am]time */
  39        unsigned quiet:1,          /* set = fake successful chmods and chowns */
  40                 showexec:1,       /* set = only set x bit for com/exe/bat */
  41                 sys_immutable:1,  /* set = system files are immutable */
  42                 dotsOK:1,         /* set = hidden and system files are named '.filename' */
  43                 isvfat:1,         /* 0=no vfat long filename support, 1=vfat support */
  44                 utf8:1,           /* Use of UTF-8 character set (Default) */
  45                 unicode_xlate:1,  /* create escape sequences for unhandled Unicode */
  46                 numtail:1,        /* Does first alias have a numeric '~1' type tail? */
  47                 flush:1,          /* write things quickly */
  48                 nocase:1,         /* Does this need case conversion? 0=need case conversion*/
  49                 usefree:1,        /* Use free_clusters for FAT32 */
  50                 tz_set:1,         /* Filesystem timestamps' offset set */
  51                 rodir:1,          /* allow ATTR_RO for directory */
  52                 discard:1,        /* Issue discard requests on deletions */
  53                 dos1xfloppy:1;    /* Assume default BPB for DOS 1.x floppies */
  54};
  55
  56#define FAT_HASH_BITS   8
  57#define FAT_HASH_SIZE   (1UL << FAT_HASH_BITS)
  58
  59/*
  60 * MS-DOS file system in-core superblock data
  61 */
  62struct msdos_sb_info {
  63        unsigned short sec_per_clus;  /* sectors/cluster */
  64        unsigned short cluster_bits;  /* log2(cluster_size) */
  65        unsigned int cluster_size;    /* cluster size */
  66        unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */
  67        unsigned short fat_start;
  68        unsigned long fat_length;     /* FAT start & length (sec.) */
  69        unsigned long dir_start;
  70        unsigned short dir_entries;   /* root dir start & entries */
  71        unsigned long data_start;     /* first data sector */
  72        unsigned long max_cluster;    /* maximum cluster number */
  73        unsigned long root_cluster;   /* first cluster of the root directory */
  74        unsigned long fsinfo_sector;  /* sector number of FAT32 fsinfo */
  75        struct mutex fat_lock;
  76        struct mutex nfs_build_inode_lock;
  77        struct mutex s_lock;
  78        unsigned int prev_free;      /* previously allocated cluster number */
  79        unsigned int free_clusters;  /* -1 if undefined */
  80        unsigned int free_clus_valid; /* is free_clusters valid? */
  81        struct fat_mount_options options;
  82        struct nls_table *nls_disk;   /* Codepage used on disk */
  83        struct nls_table *nls_io;     /* Charset used for input and display */
  84        const void *dir_ops;          /* Opaque; default directory operations */
  85        int dir_per_block;            /* dir entries per block */
  86        int dir_per_block_bits;       /* log2(dir_per_block) */
  87        unsigned int vol_id;            /*volume ID*/
  88
  89        int fatent_shift;
  90        const struct fatent_operations *fatent_ops;
  91        struct inode *fat_inode;
  92        struct inode *fsinfo_inode;
  93
  94        struct ratelimit_state ratelimit;
  95
  96        spinlock_t inode_hash_lock;
  97        struct hlist_head inode_hashtable[FAT_HASH_SIZE];
  98
  99        spinlock_t dir_hash_lock;
 100        struct hlist_head dir_hashtable[FAT_HASH_SIZE];
 101
 102        unsigned int dirty;           /* fs state before mount */
 103        struct rcu_head rcu;
 104};
 105
 106#define FAT_CACHE_VALID 0       /* special case for valid cache */
 107
 108/*
 109 * MS-DOS file system inode data in memory
 110 */
 111struct msdos_inode_info {
 112        spinlock_t cache_lru_lock;
 113        struct list_head cache_lru;
 114        int nr_caches;
 115        /* for avoiding the race between fat_free() and fat_get_cluster() */
 116        unsigned int cache_valid_id;
 117
 118        /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
 119        loff_t mmu_private;     /* physically allocated size */
 120
 121        int i_start;            /* first cluster or 0 */
 122        int i_logstart;         /* logical first cluster */
 123        int i_attrs;            /* unused attribute bits */
 124        loff_t i_pos;           /* on-disk position of directory entry or 0 */
 125        struct hlist_node i_fat_hash;   /* hash by i_location */
 126        struct hlist_node i_dir_hash;   /* hash by i_logstart */
 127        struct rw_semaphore truncate_lock; /* protect bmap against truncate */
 128        struct inode vfs_inode;
 129};
 130
 131struct fat_slot_info {
 132        loff_t i_pos;           /* on-disk position of directory entry */
 133        loff_t slot_off;        /* offset for slot or de start */
 134        int nr_slots;           /* number of slots + 1(de) in filename */
 135        struct msdos_dir_entry *de;
 136        struct buffer_head *bh;
 137};
 138
 139static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
 140{
 141        return sb->s_fs_info;
 142}
 143
 144static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
 145{
 146        return container_of(inode, struct msdos_inode_info, vfs_inode);
 147}
 148
 149/*
 150 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
 151 * save ATTR_RO instead of ->i_mode.
 152 *
 153 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
 154 * bit, it's just used as flag for app.
 155 */
 156static inline int fat_mode_can_hold_ro(struct inode *inode)
 157{
 158        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 159        umode_t mask;
 160
 161        if (S_ISDIR(inode->i_mode)) {
 162                if (!sbi->options.rodir)
 163                        return 0;
 164                mask = ~sbi->options.fs_dmask;
 165        } else
 166                mask = ~sbi->options.fs_fmask;
 167
 168        if (!(mask & S_IWUGO))
 169                return 0;
 170        return 1;
 171}
 172
 173/* Convert attribute bits and a mask to the UNIX mode. */
 174static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
 175                                   u8 attrs, umode_t mode)
 176{
 177        if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
 178                mode &= ~S_IWUGO;
 179
 180        if (attrs & ATTR_DIR)
 181                return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
 182        else
 183                return (mode & ~sbi->options.fs_fmask) | S_IFREG;
 184}
 185
 186/* Return the FAT attribute byte for this inode */
 187static inline u8 fat_make_attrs(struct inode *inode)
 188{
 189        u8 attrs = MSDOS_I(inode)->i_attrs;
 190        if (S_ISDIR(inode->i_mode))
 191                attrs |= ATTR_DIR;
 192        if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
 193                attrs |= ATTR_RO;
 194        return attrs;
 195}
 196
 197static inline void fat_save_attrs(struct inode *inode, u8 attrs)
 198{
 199        if (fat_mode_can_hold_ro(inode))
 200                MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
 201        else
 202                MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
 203}
 204
 205static inline unsigned char fat_checksum(const __u8 *name)
 206{
 207        unsigned char s = name[0];
 208        s = (s<<7) + (s>>1) + name[1];  s = (s<<7) + (s>>1) + name[2];
 209        s = (s<<7) + (s>>1) + name[3];  s = (s<<7) + (s>>1) + name[4];
 210        s = (s<<7) + (s>>1) + name[5];  s = (s<<7) + (s>>1) + name[6];
 211        s = (s<<7) + (s>>1) + name[7];  s = (s<<7) + (s>>1) + name[8];
 212        s = (s<<7) + (s>>1) + name[9];  s = (s<<7) + (s>>1) + name[10];
 213        return s;
 214}
 215
 216static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
 217{
 218        return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
 219                + sbi->data_start;
 220}
 221
 222static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
 223                                loff_t i_pos, sector_t *blknr, int *offset)
 224{
 225        *blknr = i_pos >> sbi->dir_per_block_bits;
 226        *offset = i_pos & (sbi->dir_per_block - 1);
 227}
 228
 229static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
 230                                        struct inode *inode)
 231{
 232        loff_t i_pos;
 233#if BITS_PER_LONG == 32
 234        spin_lock(&sbi->inode_hash_lock);
 235#endif
 236        i_pos = MSDOS_I(inode)->i_pos;
 237#if BITS_PER_LONG == 32
 238        spin_unlock(&sbi->inode_hash_lock);
 239#endif
 240        return i_pos;
 241}
 242
 243static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
 244{
 245#ifdef __BIG_ENDIAN
 246        while (len--) {
 247                *dst++ = src[0] | (src[1] << 8);
 248                src += 2;
 249        }
 250#else
 251        memcpy(dst, src, len * 2);
 252#endif
 253}
 254
 255static inline int fat_get_start(const struct msdos_sb_info *sbi,
 256                                const struct msdos_dir_entry *de)
 257{
 258        int cluster = le16_to_cpu(de->start);
 259        if (sbi->fat_bits == 32)
 260                cluster |= (le16_to_cpu(de->starthi) << 16);
 261        return cluster;
 262}
 263
 264static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
 265{
 266        de->start   = cpu_to_le16(cluster);
 267        de->starthi = cpu_to_le16(cluster >> 16);
 268}
 269
 270static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
 271{
 272#ifdef __BIG_ENDIAN
 273        while (len--) {
 274                dst[0] = *src & 0x00FF;
 275                dst[1] = (*src & 0xFF00) >> 8;
 276                dst += 2;
 277                src++;
 278        }
 279#else
 280        memcpy(dst, src, len * 2);
 281#endif
 282}
 283
 284/* fat/cache.c */
 285extern void fat_cache_inval_inode(struct inode *inode);
 286extern int fat_get_cluster(struct inode *inode, int cluster,
 287                           int *fclus, int *dclus);
 288extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector,
 289                                  sector_t last_block,
 290                                  unsigned long *mapped_blocks, sector_t *bmap);
 291extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
 292                    unsigned long *mapped_blocks, int create, bool from_bmap);
 293
 294/* fat/dir.c */
 295extern const struct file_operations fat_dir_operations;
 296extern int fat_search_long(struct inode *inode, const unsigned char *name,
 297                           int name_len, struct fat_slot_info *sinfo);
 298extern int fat_dir_empty(struct inode *dir);
 299extern int fat_subdirs(struct inode *dir);
 300extern int fat_scan(struct inode *dir, const unsigned char *name,
 301                    struct fat_slot_info *sinfo);
 302extern int fat_scan_logstart(struct inode *dir, int i_logstart,
 303                             struct fat_slot_info *sinfo);
 304extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 305                                struct msdos_dir_entry **de);
 306extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
 307extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
 308                           struct fat_slot_info *sinfo);
 309extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
 310
 311/* fat/fatent.c */
 312struct 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
 324static 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
 333static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
 334{
 335        fatent->entry = entry;
 336        fatent->u.ent32_p = NULL;
 337}
 338
 339static 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
 350extern void fat_ent_access_init(struct super_block *sb);
 351extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
 352                        int entry);
 353extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
 354                         int new, int wait);
 355extern int fat_alloc_clusters(struct inode *inode, int *cluster,
 356                              int nr_cluster);
 357extern int fat_free_clusters(struct inode *inode, int cluster);
 358extern int fat_count_free_clusters(struct super_block *sb);
 359
 360/* fat/file.c */
 361extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
 362                              unsigned long arg);
 363extern const struct file_operations fat_file_operations;
 364extern const struct inode_operations fat_file_inode_operations;
 365extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
 366extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
 367extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
 368                       struct kstat *stat);
 369extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
 370                          int datasync);
 371
 372/* fat/inode.c */
 373extern int fat_block_truncate_page(struct inode *inode, loff_t from);
 374extern void fat_attach(struct inode *inode, loff_t i_pos);
 375extern void fat_detach(struct inode *inode);
 376extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
 377extern struct inode *fat_build_inode(struct super_block *sb,
 378                        struct msdos_dir_entry *de, loff_t i_pos);
 379extern int fat_sync_inode(struct inode *inode);
 380extern int fat_fill_super(struct super_block *sb, void *data, int silent,
 381                          int isvfat, void (*setup)(struct super_block *));
 382extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
 383
 384extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
 385                            struct inode *i2);
 386static inline unsigned long fat_dir_hash(int logstart)
 387{
 388        return hash_32(logstart, FAT_HASH_BITS);
 389}
 390extern int fat_add_cluster(struct inode *inode);
 391
 392/* fat/misc.c */
 393extern __printf(3, 4) __cold
 394void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
 395#define fat_fs_error(sb, fmt, args...)          \
 396        __fat_fs_error(sb, 1, fmt , ## args)
 397#define fat_fs_error_ratelimit(sb, fmt, args...) \
 398        __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
 399__printf(3, 4) __cold
 400void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
 401#define fat_msg_ratelimit(sb, level, fmt, args...)      \
 402        do {    \
 403                        if (__ratelimit(&MSDOS_SB(sb)->ratelimit))      \
 404                                fat_msg(sb, level, fmt, ## args);       \
 405         } while (0)
 406extern int fat_clusters_flush(struct super_block *sb);
 407extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
 408extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
 409                              __le16 __time, __le16 __date, u8 time_cs);
 410extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
 411                              __le16 *time, __le16 *date, u8 *time_cs);
 412extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
 413
 414int fat_cache_init(void);
 415void fat_cache_destroy(void);
 416
 417/* fat/nfs.c */
 418extern const struct export_operations fat_export_ops;
 419extern const struct export_operations fat_export_ops_nostale;
 420
 421/* helper for printk */
 422typedef unsigned long long      llu;
 423
 424#endif /* !_FAT_H */
 425