/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
 */

#ifndef _EXFAT_FS_H
#define _EXFAT_FS_H

#include <linux/fs.h>
#include <linux/ratelimit.h>
#include <linux/nls.h>
#include <linux/blkdev.h>
#include <uapi/linux/exfat.h>

#define EXFAT_ROOT_INO          1

/*
 * exfat error flags
 */
enum exfat_error_mode {
        EXFAT_ERRORS_CONT,      /* ignore error and continue */
        EXFAT_ERRORS_PANIC,     /* panic on error */
        EXFAT_ERRORS_RO,        /* remount r/o on error */
};

/*
 * exfat nls lossy flag
 */
enum {
        NLS_NAME_NO_LOSSY =     0,      /* no lossy */
        NLS_NAME_LOSSY =        1 << 0, /* just detected incorrect filename(s) */
};

#define EXFAT_HASH_BITS         8
#define EXFAT_HASH_SIZE         (1UL << EXFAT_HASH_BITS)

/*
 * Type Definitions
 */
#define ES_2_ENTRIES            2
#define ES_ALL_ENTRIES          0

#define ES_IDX_FILE             0
#define ES_IDX_STREAM           1
#define ES_IDX_FIRST_FILENAME   2
#define EXFAT_FILENAME_ENTRY_NUM(name_len) \
        DIV_ROUND_UP(name_len, EXFAT_FILE_NAME_LEN)
#define ES_IDX_LAST_FILENAME(name_len)  \
        (ES_IDX_FIRST_FILENAME + EXFAT_FILENAME_ENTRY_NUM(name_len) - 1)

#define DIR_DELETED             0xFFFFFFF7

/* type values */
#define TYPE_UNUSED             0x0000
#define TYPE_DELETED            0x0001
#define TYPE_INVALID            0x0002
#define TYPE_CRITICAL_PRI       0x0100
#define TYPE_BITMAP             0x0101
#define TYPE_UPCASE             0x0102
#define TYPE_VOLUME             0x0103
#define TYPE_DIR                0x0104
#define TYPE_FILE               0x011F
#define TYPE_CRITICAL_SEC       0x0200
#define TYPE_STREAM             0x0201
#define TYPE_EXTEND             0x0202
#define TYPE_ACL                0x0203
#define TYPE_BENIGN_PRI         0x0400
#define TYPE_GUID               0x0401
#define TYPE_PADDING            0x0402
#define TYPE_ACLTAB             0x0403
#define TYPE_BENIGN_SEC         0x0800
#define TYPE_VENDOR_EXT         0x0801
#define TYPE_VENDOR_ALLOC       0x0802

#define MAX_CHARSET_SIZE        6 /* max size of multi-byte character */
#define MAX_NAME_LENGTH         255 /* max len of file name excluding NULL */
#define MAX_VFSNAME_BUF_SIZE    ((MAX_NAME_LENGTH + 1) * MAX_CHARSET_SIZE)

#define EXFAT_HINT_NONE         -1
#define EXFAT_MIN_SUBDIR        2

/*
 * helpers for cluster size to byte conversion.
 */
#define EXFAT_CLU_TO_B(b, sbi)          ((b) << (sbi)->cluster_size_bits)
#define EXFAT_B_TO_CLU(b, sbi)          ((b) >> (sbi)->cluster_size_bits)
#define EXFAT_B_TO_CLU_ROUND_UP(b, sbi) \
        (((b - 1) >> (sbi)->cluster_size_bits) + 1)
#define EXFAT_CLU_OFFSET(off, sbi)      ((off) & ((sbi)->cluster_size - 1))

/*
 * helpers for block size to byte conversion.
 */
#define EXFAT_BLK_TO_B(b, sb)           ((b) << (sb)->s_blocksize_bits)
#define EXFAT_B_TO_BLK(b, sb)           ((b) >> (sb)->s_blocksize_bits)
#define EXFAT_B_TO_BLK_ROUND_UP(b, sb)  \
        (((b - 1) >> (sb)->s_blocksize_bits) + 1)
#define EXFAT_BLK_OFFSET(off, sb)       ((off) & ((sb)->s_blocksize - 1))

/*
 * helpers for block size to dentry size conversion.
 */
#define EXFAT_B_TO_DEN(b)               ((b) >> DENTRY_SIZE_BITS)
#define EXFAT_DEN_TO_B(b)               ((b) << DENTRY_SIZE_BITS)

/*
 * helpers for cluster size to dentry size conversion.
 */
#define EXFAT_CLU_TO_DEN(clu, sbi)      \
        ((clu) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
#define EXFAT_DEN_TO_CLU(dentry, sbi)   \
        ((dentry) >> ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))

/*
 * helpers for fat entry.
 */
#define FAT_ENT_SIZE (4)
#define FAT_ENT_SIZE_BITS (2)
#define FAT_ENT_OFFSET_SECTOR(sb, loc) (EXFAT_SB(sb)->FAT1_start_sector + \
        (((u64)loc << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits))
#define FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc)  \
        ((loc << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1))

/*
 * helpers for bitmap.
 */
#define CLUSTER_TO_BITMAP_ENT(clu) ((clu) - EXFAT_RESERVED_CLUSTERS)
#define BITMAP_ENT_TO_CLUSTER(ent) ((ent) + EXFAT_RESERVED_CLUSTERS)
#define BITS_PER_SECTOR(sb) ((sb)->s_blocksize * BITS_PER_BYTE)
#define BITS_PER_SECTOR_MASK(sb) (BITS_PER_SECTOR(sb) - 1)
#define BITMAP_OFFSET_SECTOR_INDEX(sb, ent) \
        ((ent / BITS_PER_BYTE) >> (sb)->s_blocksize_bits)
#define BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent) (ent & BITS_PER_SECTOR_MASK(sb))
#define BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent) \
        ((ent / BITS_PER_BYTE) & ((sb)->s_blocksize - 1))
#define IGNORED_BITS_REMAINED(clu, clu_base) ((1UL << ((clu) - (clu_base))) - 1)

#define ES_ENTRY_NUM(name_len)  (ES_IDX_LAST_FILENAME(name_len) + 1)
/* 19 entries = 1 file entry + 1 stream entry + 17 filename entries */
#define ES_MAX_ENTRY_NUM        ES_ENTRY_NUM(MAX_NAME_LENGTH)

/*
 * 19 entries x 32 bytes/entry = 608 bytes.
 * The 608 bytes are in 3 sectors at most (even 512 Byte sector).
 */
#define DIR_CACHE_SIZE          \
        (DIV_ROUND_UP(EXFAT_DEN_TO_B(ES_MAX_ENTRY_NUM), SECTOR_SIZE) + 1)

/* Superblock flags */
#define EXFAT_FLAGS_SHUTDOWN    1

struct exfat_dentry_namebuf {
        char *lfn;
        int lfnbuf_len; /* usually MAX_UNINAME_BUF_SIZE */
};

/* unicode name structure */
struct exfat_uni_name {
        /* +3 for null and for converting */
        unsigned short name[MAX_NAME_LENGTH + 3];
        u16 name_hash;
        unsigned char name_len;
};

/* directory structure */
struct exfat_chain {
        unsigned int dir;
        unsigned int size;
        unsigned char flags;
};

/* first empty entry hint information */
struct exfat_hint_femp {
        /* entry index of a directory */
        int eidx;
        /* count of continuous empty entry */
        int count;
        /* the cluster that first empty slot exists in */
        struct exfat_chain cur;
};

/* hint structure */
struct exfat_hint {
        unsigned int clu;
        union {
                unsigned int off; /* cluster offset */
                int eidx; /* entry index */
        };
};

struct exfat_entry_set_cache {
        struct super_block *sb;
        unsigned int start_off;
        int num_bh;
        struct buffer_head *__bh[DIR_CACHE_SIZE];
        struct buffer_head **bh;
        unsigned int num_entries;
        bool modified;
};

#define IS_DYNAMIC_ES(es)       ((es)->__bh != (es)->bh)

struct exfat_dir_entry {
        /* the cluster where file dentry is located */
        struct exfat_chain dir;
        /* the index of file dentry in ->dir */
        int entry;
        unsigned int type;
        unsigned int start_clu;
        unsigned char flags;
        unsigned short attr;
        loff_t size;
        loff_t valid_size;
        unsigned int num_subdirs;
        struct timespec64 atime;
        struct timespec64 mtime;
        struct timespec64 crtime;
        struct exfat_dentry_namebuf namebuf;
};

/*
 * exfat mount in-memory data
 */
struct exfat_mount_options {
        kuid_t fs_uid;
        kgid_t fs_gid;
        unsigned short fs_fmask;
        unsigned short fs_dmask;
        /* permission for setting the [am]time */
        unsigned short allow_utime;
        /* charset for filename input/display */
        char *iocharset;
        /* on error: continue, panic, remount-ro */
        enum exfat_error_mode errors;
        unsigned utf8:1, /* Use of UTF-8 character set */
                 sys_tz:1, /* Use local timezone */
                 discard:1, /* Issue discard requests on deletions */
                 keep_last_dots:1; /* Keep trailing periods in paths */
        int time_offset; /* Offset of timestamps from UTC (in minutes) */
        /* Support creating zero-size directory, default: false */
        bool zero_size_dir;
};

/*
 * EXFAT file system superblock in-memory data
 */
struct exfat_sb_info {
        unsigned long long num_sectors; /* num of sectors in volume */
        unsigned int num_clusters; /* num of clusters in volume */
        unsigned int cluster_size; /* cluster size in bytes */
        unsigned int cluster_size_bits;
        unsigned int sect_per_clus; /* cluster size in sectors */
        unsigned int sect_per_clus_bits;
        unsigned long long FAT1_start_sector; /* FAT1 start sector */
        unsigned long long FAT2_start_sector; /* FAT2 start sector */
        unsigned long long data_start_sector; /* data area start sector */
        unsigned int num_FAT_sectors; /* num of FAT sectors */
        unsigned int root_dir; /* root dir cluster */
        unsigned int dentries_per_clu; /* num of dentries per cluster */
        unsigned int vol_flags; /* volume flags */
        unsigned int vol_flags_persistent; /* volume flags to retain */
        struct buffer_head *boot_bh; /* buffer_head of BOOT sector */

        unsigned int map_clu; /* allocation bitmap start cluster */
        unsigned int map_sectors; /* num of allocation bitmap sectors */
        struct buffer_head **vol_amap; /* allocation bitmap */

        unsigned short *vol_utbl; /* upcase table */

        unsigned int clu_srch_ptr; /* cluster search pointer */
        unsigned int used_clusters; /* number of used clusters */

        unsigned long s_exfat_flags; /* Exfat superblock flags */

        struct mutex s_lock; /* superblock lock */
        struct mutex bitmap_lock; /* bitmap lock */
        struct exfat_mount_options options;
        struct nls_table *nls_io; /* Charset used for input and display */
        struct ratelimit_state ratelimit;

        spinlock_t inode_hash_lock;
        struct hlist_head inode_hashtable[EXFAT_HASH_SIZE];
        struct rcu_head rcu;
};

#define EXFAT_CACHE_VALID       0

/*
 * EXFAT file system inode in-memory data
 */
struct exfat_inode_info {
        /* the cluster where file dentry is located */
        struct exfat_chain dir;
        /* the index of file dentry in ->dir */
        int entry;
        unsigned int type;
        unsigned short attr;
        unsigned int start_clu;
        unsigned char flags;
        /*
         * the copy of low 32bit of i_version to check
         * the validation of hint_stat.
         */
        unsigned int version;

        /* hint for cluster last accessed */
        struct exfat_hint hint_bmap;
        /* hint for entry index we try to lookup next time */
        struct exfat_hint hint_stat;
        /* hint for first empty entry */
        struct exfat_hint_femp hint_femp;

        spinlock_t cache_lru_lock;
        struct list_head cache_lru;
        int nr_caches;
        /* for avoiding the race between alloc and free */
        unsigned int cache_valid_id;

        /* on-disk position of directory entry or 0 */
        loff_t i_pos;
        loff_t valid_size;
        /* hash by i_location */
        struct hlist_node i_hash_fat;
        /* protect bmap against truncate */
        struct rw_semaphore truncate_lock;
        struct inode vfs_inode;
        /* File creation time */
        struct timespec64 i_crtime;
};

static inline struct exfat_sb_info *EXFAT_SB(struct super_block *sb)
{
        return sb->s_fs_info;
}

static inline struct exfat_inode_info *EXFAT_I(struct inode *inode)
{
        return container_of(inode, struct exfat_inode_info, vfs_inode);
}

static inline int exfat_forced_shutdown(struct super_block *sb)
{
        return test_bit(EXFAT_FLAGS_SHUTDOWN, &EXFAT_SB(sb)->s_exfat_flags);
}

/*
 * If ->i_mode can't hold 0222 (i.e. ATTR_RO), we use ->i_attrs to
 * save ATTR_RO instead of ->i_mode.
 *
 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
 * bit, it's just used as flag for app.
 */
static inline int exfat_mode_can_hold_ro(struct inode *inode)
{
        struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);

        if (S_ISDIR(inode->i_mode))
                return 0;

        if ((~sbi->options.fs_fmask) & 0222)
                return 1;
        return 0;
}

/* Convert attribute bits and a mask to the UNIX mode. */
static inline mode_t exfat_make_mode(struct exfat_sb_info *sbi,
                unsigned short attr, mode_t mode)
{
        if ((attr & EXFAT_ATTR_READONLY) && !(attr & EXFAT_ATTR_SUBDIR))
                mode &= ~0222;

        if (attr & EXFAT_ATTR_SUBDIR)
                return (mode & ~sbi->options.fs_dmask) | S_IFDIR;

        return (mode & ~sbi->options.fs_fmask) | S_IFREG;
}

/* Return the FAT attribute byte for this inode */
static inline unsigned short exfat_make_attr(struct inode *inode)
{
        unsigned short attr = EXFAT_I(inode)->attr;

        if (S_ISDIR(inode->i_mode))
                attr |= EXFAT_ATTR_SUBDIR;
        if (exfat_mode_can_hold_ro(inode) && !(inode->i_mode & 0222))
                attr |= EXFAT_ATTR_READONLY;
        return attr;
}

static inline void exfat_save_attr(struct inode *inode, unsigned short attr)
{
        if (exfat_mode_can_hold_ro(inode))
                EXFAT_I(inode)->attr = attr & (EXFAT_ATTR_RWMASK | EXFAT_ATTR_READONLY);
        else
                EXFAT_I(inode)->attr = attr & EXFAT_ATTR_RWMASK;
}

static inline bool exfat_is_last_sector_in_cluster(struct exfat_sb_info *sbi,
                sector_t sec)
{
        return ((sec - sbi->data_start_sector + 1) &
                ((1 << sbi->sect_per_clus_bits) - 1)) == 0;
}

static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
                unsigned int clus)
{
        return ((sector_t)(clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
                sbi->data_start_sector;
}

static inline unsigned int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
                sector_t sec)
{
        return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
                EXFAT_RESERVED_CLUSTERS;
}

static inline bool is_valid_cluster(struct exfat_sb_info *sbi,
                unsigned int clus)
{
        return clus >= EXFAT_FIRST_CLUSTER && clus < sbi->num_clusters;
}

static inline loff_t exfat_ondisk_size(const struct inode *inode)
{
        return ((loff_t)inode->i_blocks) << 9;
}

/* super.c */
int exfat_set_volume_dirty(struct super_block *sb);
int exfat_clear_volume_dirty(struct super_block *sb);

/* fatent.c */
#define exfat_get_next_cluster(sb, pclu) exfat_ent_get(sb, *(pclu), pclu, NULL)

int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
                struct exfat_chain *p_chain, bool sync_bmap);
int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain);
int exfat_ent_get(struct super_block *sb, unsigned int loc,
                unsigned int *content, struct buffer_head **last);
int exfat_ent_set(struct super_block *sb, unsigned int loc,
                unsigned int content);
int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
                unsigned int len);
int exfat_zeroed_cluster(struct inode *dir, unsigned int clu);
int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
                unsigned int *ret_clu);
int exfat_count_num_clusters(struct super_block *sb,
                struct exfat_chain *p_chain, unsigned int *ret_count);

/* balloc.c */
int exfat_load_bitmap(struct super_block *sb);
void exfat_free_bitmap(struct exfat_sb_info *sbi);
int exfat_set_bitmap(struct super_block *sb, unsigned int clu, bool sync);
int exfat_clear_bitmap(struct super_block *sb, unsigned int clu, bool sync);
bool exfat_test_bitmap(struct super_block *sb, unsigned int clu);
unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
int exfat_trim_fs(struct inode *inode, struct fstrim_range *range);

/* file.c */
extern const struct file_operations exfat_file_operations;
int __exfat_truncate(struct inode *inode);
void exfat_truncate(struct inode *inode);
int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                  struct iattr *attr);
int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
                  struct kstat *stat, unsigned int request_mask,
                  unsigned int query_flags);
int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
                                unsigned long arg);
int exfat_force_shutdown(struct super_block *sb, u32 flags);

/* namei.c */
extern const struct dentry_operations exfat_dentry_ops;
extern const struct dentry_operations exfat_utf8_dentry_ops;
int exfat_find_empty_entry(struct inode *inode,
                struct exfat_chain *p_dir, int num_entries,
                           struct exfat_entry_set_cache *es);

/* cache.c */
int exfat_cache_init(void);
void exfat_cache_shutdown(void);
void exfat_cache_inval_inode(struct inode *inode);
int exfat_get_cluster(struct inode *inode, unsigned int cluster,
                unsigned int *dclus, unsigned int *count, unsigned int *last_dclus);

/* dir.c */
extern const struct inode_operations exfat_dir_inode_operations;
extern const struct file_operations exfat_dir_operations;
unsigned int exfat_get_entry_type(struct exfat_dentry *p_entry);
void exfat_init_dir_entry(struct exfat_entry_set_cache *es,
                unsigned int type, unsigned int start_clu,
                unsigned long long size, struct timespec64 *ts);
void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries,
                struct exfat_uni_name *p_uniname);
void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es,
                int order);
void exfat_update_dir_chksum(struct exfat_entry_set_cache *es);
int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
                struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
                struct exfat_hint *hint_opt);
int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
                struct exfat_chain *p_dir, int entry, struct buffer_head **bh);
struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
                int num);
int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
                struct super_block *sb, struct exfat_chain *p_dir, int entry,
                unsigned int num_entries);
#define exfat_get_dentry_set_by_ei(es, sb, ei)          \
        exfat_get_dentry_set(es, sb, &(ei)->dir, (ei)->entry, ES_ALL_ENTRIES)
int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es,
                struct super_block *sb, struct exfat_chain *p_dir, int entry,
                unsigned int num_entries);
int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync);
int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
int exfat_read_volume_label(struct super_block *sb,
                            struct exfat_uni_name *label_out);
int exfat_write_volume_label(struct super_block *sb,
                             struct exfat_uni_name *label);

/* inode.c */
extern const struct inode_operations exfat_file_inode_operations;
void exfat_sync_inode(struct inode *inode);
struct inode *exfat_build_inode(struct super_block *sb,
                struct exfat_dir_entry *info, loff_t i_pos);
void exfat_hash_inode(struct inode *inode, loff_t i_pos);
void exfat_unhash_inode(struct inode *inode);
struct inode *exfat_iget(struct super_block *sb, loff_t i_pos);
int __exfat_write_inode(struct inode *inode, int sync);
int exfat_write_inode(struct inode *inode, struct writeback_control *wbc);
void exfat_evict_inode(struct inode *inode);
int exfat_block_truncate_page(struct inode *inode, loff_t from);

/* exfat/nls.c */
unsigned short exfat_toupper(struct super_block *sb, unsigned short a);
int exfat_uniname_ncmp(struct super_block *sb, unsigned short *a,
                unsigned short *b, unsigned int len);
int exfat_utf16_to_nls(struct super_block *sb,
                struct exfat_uni_name *uniname, unsigned char *p_cstring,
                int len);
int exfat_nls_to_utf16(struct super_block *sb,
                const unsigned char *p_cstring, const int len,
                struct exfat_uni_name *uniname, int *p_lossy);
int exfat_create_upcase_table(struct super_block *sb);
void exfat_free_upcase_table(struct exfat_sb_info *sbi);

/* exfat/misc.c */
void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
                __printf(3, 4) __cold;
#define exfat_fs_error(sb, fmt, args...)          \
                __exfat_fs_error(sb, 1, fmt, ## args)
#define exfat_fs_error_ratelimit(sb, fmt, args...) \
                __exfat_fs_error(sb, __ratelimit(&EXFAT_SB(sb)->ratelimit), \
                fmt, ## args)

/* expand to pr_*() with prefix */
#define exfat_err(sb, fmt, ...)                                         \
        pr_err("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
#define exfat_warn(sb, fmt, ...)                                        \
        pr_warn("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
#define exfat_info(sb, fmt, ...)                                        \
        pr_info("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
#define exfat_debug(sb, fmt, ...)                                       \
        pr_debug("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)

void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
                u8 tz, __le16 time, __le16 date, u8 time_cs);
void exfat_truncate_atime(struct timespec64 *ts);
void exfat_truncate_inode_atime(struct inode *inode);
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
                u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
void exfat_update_bh(struct buffer_head *bh, int sync);
int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync);
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
                unsigned int size, unsigned char flags);
void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);

#endif /* !_EXFAT_FS_H */