/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FAT_H
#define _FAT_H
#include <linux/buffer_head.h>
#include <linux/nls.h>
#include <linux/hash.h>
#include <linux/ratelimit.h>
#include <linux/msdos_fs.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
/*
* vfat shortname flags
*/
#define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
#define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
#define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
#define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
#define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
#define FAT_ERRORS_CONT 1 /* ignore error and continue */
#define FAT_ERRORS_PANIC 2 /* panic on error */
#define FAT_ERRORS_RO 3 /* remount r/o on error */
#define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */
#define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */
struct fat_mount_options {
kuid_t fs_uid;
kgid_t fs_gid;
unsigned short fs_fmask;
unsigned short fs_dmask;
unsigned short codepage; /* Codepage for shortname conversions */
int time_offset; /* Offset of timestamps from UTC (in minutes) */
char *iocharset; /* Charset used for filename input/display */
unsigned short shortname; /* flags for shortname display/create rule */
unsigned char name_check; /* r = relaxed, n = normal, s = strict */
unsigned char errors; /* On error: continue, panic, remount-ro */
unsigned char nfs; /* NFS support: nostale_ro, stale_rw */
unsigned short allow_utime;/* permission for setting the [am]time */
unsigned quiet:1, /* set = fake successful chmods and chowns */
showexec:1, /* set = only set x bit for com/exe/bat */
sys_immutable:1, /* set = system files are immutable */
dotsOK:1, /* set = hidden and system files are named '.filename' */
isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
utf8:1, /* Use of UTF-8 character set (Default) */
unicode_xlate:1, /* create escape sequences for unhandled Unicode */
numtail:1, /* Does first alias have a numeric '~1' type tail? */
flush:1, /* write things quickly */
nocase:1, /* Does this need case conversion? 0=need case conversion*/
usefree:1, /* Use free_clusters for FAT32 */
tz_set:1, /* Filesystem timestamps' offset set */
rodir:1, /* allow ATTR_RO for directory */
discard:1, /* Issue discard requests on deletions */
dos1xfloppy:1, /* Assume default BPB for DOS 1.x floppies */
debug:1; /* Not currently used */
};
#define FAT_HASH_BITS 8
#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
/*
* MS-DOS file system in-core superblock data
*/
struct msdos_sb_info {
unsigned short sec_per_clus; /* sectors/cluster */
unsigned short cluster_bits; /* log2(cluster_size) */
unsigned int cluster_size; /* cluster size */
unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */
unsigned short fat_start;
unsigned long fat_length; /* FAT start & length (sec.) */
unsigned long dir_start;
unsigned short dir_entries; /* root dir start & entries */
unsigned long data_start; /* first data sector */
unsigned long max_cluster; /* maximum cluster number */
unsigned long root_cluster; /* first cluster of the root directory */
unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
struct mutex fat_lock;
struct mutex nfs_build_inode_lock;
struct mutex s_lock;
unsigned int prev_free; /* previously allocated cluster number */
unsigned int free_clusters; /* -1 if undefined */
unsigned int free_clus_valid; /* is free_clusters valid? */
struct fat_mount_options options;
struct nls_table *nls_disk; /* Codepage used on disk */
struct nls_table *nls_io; /* Charset used for input and display */
const void *dir_ops; /* Opaque; default directory operations */
int dir_per_block; /* dir entries per block */
int dir_per_block_bits; /* log2(dir_per_block) */
unsigned int vol_id; /*volume ID*/
int fatent_shift;
const struct fatent_operations *fatent_ops;
struct inode *fat_inode;
struct inode *fsinfo_inode;
struct ratelimit_state ratelimit;
spinlock_t inode_hash_lock;
struct hlist_head inode_hashtable[FAT_HASH_SIZE];
spinlock_t dir_hash_lock;
struct hlist_head dir_hashtable[FAT_HASH_SIZE];
unsigned int dirty; /* fs state before mount */
struct rcu_head rcu;
};
#define FAT_CACHE_VALID 0 /* special case for valid cache */
/*
* MS-DOS file system inode data in memory
*/
struct msdos_inode_info {
spinlock_t cache_lru_lock;
struct list_head cache_lru;
int nr_caches;
/* for avoiding the race between fat_free() and fat_get_cluster() */
unsigned int cache_valid_id;
/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
loff_t mmu_private; /* physically allocated size */
int i_start; /* first cluster or 0 */
int i_logstart; /* logical first cluster */
int i_attrs; /* unused attribute bits */
loff_t i_pos; /* on-disk position of directory entry or 0 */
struct hlist_node i_fat_hash; /* hash by i_location */
struct hlist_node i_dir_hash; /* hash by i_logstart */
struct rw_semaphore truncate_lock; /* protect bmap against truncate */
struct timespec64 i_crtime; /* File creation (birth) time */
struct inode vfs_inode;
};
struct fat_slot_info {
loff_t i_pos; /* on-disk position of directory entry */
loff_t slot_off; /* offset for slot or de start */
int nr_slots; /* number of slots + 1(de) in filename */
struct msdos_dir_entry *de;
struct buffer_head *bh;
};
static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
{
return sb->s_fs_info;
}
/*
* Functions that determine the variant of the FAT file system (i.e.,
* whether this is FAT12, FAT16 or FAT32.
*/
static inline bool is_fat12(const struct msdos_sb_info *sbi)
{
return sbi->fat_bits == 12;
}
static inline bool is_fat16(const struct msdos_sb_info *sbi)
{
return sbi->fat_bits == 16;
}
static inline bool is_fat32(const struct msdos_sb_info *sbi)
{
return sbi->fat_bits == 32;
}
/* Maximum number of clusters */
static inline u32 max_fat(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
return is_fat32(sbi) ? MAX_FAT32 :
is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12;
}
static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
{
return container_of(inode, struct msdos_inode_info, vfs_inode);
}
/*
* If ->i_mode can't hold S_IWUGO (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 fat_mode_can_hold_ro(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
umode_t mask;
if (S_ISDIR(inode->i_mode)) {
if (!sbi->options.rodir)
return 0;
mask = ~sbi->options.fs_dmask;
} else
mask = ~sbi->options.fs_fmask;
if (!(mask & S_IWUGO))
return 0;
return 1;
}
/* Convert attribute bits and a mask to the UNIX mode. */
static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
u8 attrs, umode_t mode)
{
if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
mode &= ~S_IWUGO;
if (attrs & ATTR_DIR)
return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
else
return (mode & ~sbi->options.fs_fmask) | S_IFREG;
}
/* Return the FAT attribute byte for this inode */
static inline u8 fat_make_attrs(struct inode *inode)
{
u8 attrs = MSDOS_I(inode)->i_attrs;
if (S_ISDIR(inode->i_mode))
attrs |= ATTR_DIR;
if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
attrs |= ATTR_RO;
return attrs;
}
static inline void fat_save_attrs(struct inode *inode, u8 attrs)
{
if (fat_mode_can_hold_ro(inode))
MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
else
MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
}
static inline unsigned char fat_checksum(const __u8 *name)
{
unsigned char s = name[0];
s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
return s;
}
static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
{
return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
+ sbi->data_start;
}
static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
loff_t i_pos, sector_t *blknr, int *offset)
{
*blknr = i_pos >> sbi->dir_per_block_bits;
*offset = i_pos & (sbi->dir_per_block - 1);
}
static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
struct inode *inode)
{
loff_t i_pos;
#if BITS_PER_LONG == 32
spin_lock(&sbi->inode_hash_lock);
#endif
i_pos = MSDOS_I(inode)->i_pos;
#if BITS_PER_LONG == 32
spin_unlock(&sbi->inode_hash_lock);
#endif
return i_pos;
}
static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
{
#ifdef __BIG_ENDIAN
while (len--) {
*dst++ = src[0] | (src[1] << 8);
src += 2;
}
#else
memcpy(dst, src, len * 2);
#endif
}
static inline int fat_get_start(const struct msdos_sb_info *sbi,
const struct msdos_dir_entry *de)
{
int cluster = le16_to_cpu(de->start);
if (is_fat32(sbi))
cluster |= (le16_to_cpu(de->starthi) << 16);
return cluster;
}
static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
{
de->start = cpu_to_le16(cluster);
de->starthi = cpu_to_le16(cluster >> 16);
}
static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
{
#ifdef __BIG_ENDIAN
while (len--) {
dst[0] = *src & 0x00FF;
dst[1] = (*src & 0xFF00) >> 8;
dst += 2;
src++;
}
#else
memcpy(dst, src, len * 2);
#endif
}
/* fat/cache.c */
extern void fat_cache_inval_inode(struct inode *inode);
extern int fat_get_cluster(struct inode *inode, int cluster,
int *fclus, int *dclus);
extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector,
sector_t last_block,
unsigned long *mapped_blocks, sector_t *bmap);
extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
unsigned long *mapped_blocks, int create, bool from_bmap);
/* fat/dir.c */
extern const struct file_operations fat_dir_operations;
extern int fat_search_long(struct inode *inode, const unsigned char *name,
int name_len, struct fat_slot_info *sinfo);
extern int fat_dir_empty(struct inode *dir);
extern int fat_subdirs(struct inode *dir);
extern int fat_scan(struct inode *dir, const unsigned char *name,
struct fat_slot_info *sinfo);
extern int fat_scan_logstart(struct inode *dir, int i_logstart,
struct fat_slot_info *sinfo);
extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
struct msdos_dir_entry **de);
extern int fat_alloc_new_dir(struct inode *dir, struct timespec64 *ts);
extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
struct fat_slot_info *sinfo);
extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
/* fat/fatent.c */
struct fat_entry {
int entry;
union {
u8 *ent12_p[2];
__le16 *ent16_p;
__le32 *ent32_p;
} u;
int nr_bhs;
struct buffer_head *bhs[2];
struct inode *fat_inode;
};
static inline void fatent_init(struct fat_entry *fatent)
{
fatent->nr_bhs = 0;
fatent->entry = 0;
fatent->u.ent32_p = NULL;
fatent->bhs[0] = fatent->bhs[1] = NULL;
fatent->fat_inode = NULL;
}
static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
{
fatent->entry = entry;
fatent->u.ent32_p = NULL;
}
static inline void fatent_brelse(struct fat_entry *fatent)
{
int i;
fatent->u.ent32_p = NULL;
for (i = 0; i < fatent->nr_bhs; i++)
brelse(fatent->bhs[i]);
fatent->nr_bhs = 0;
fatent->bhs[0] = fatent->bhs[1] = NULL;
fatent->fat_inode = NULL;
}
static inline bool fat_valid_entry(struct msdos_sb_info *sbi, int entry)
{
return FAT_START_ENT <= entry && entry < sbi->max_cluster;
}
extern void fat_ent_access_init(struct super_block *sb);
extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
int entry);
extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
int new, int wait);
extern int fat_alloc_clusters(struct inode *inode, int *cluster,
int nr_cluster);
extern int fat_free_clusters(struct inode *inode, int cluster);
extern int fat_count_free_clusters(struct super_block *sb);
extern int fat_trim_fs(struct inode *inode, struct fstrim_range *range);
/* fat/file.c */
extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg);
extern const struct file_operations fat_file_operations;
extern const struct inode_operations fat_file_inode_operations;
extern int fat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr);
extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
extern int fat_getattr(struct mnt_idmap *idmap,
const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags);
extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
int datasync);
/* fat/inode.c */
extern int fat_block_truncate_page(struct inode *inode, loff_t from);
extern void fat_attach(struct inode *inode, loff_t i_pos);
extern void fat_detach(struct inode *inode);
extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
extern struct inode *fat_build_inode(struct super_block *sb,
struct msdos_dir_entry *de, loff_t i_pos);
extern int fat_sync_inode(struct inode *inode);
extern int fat_fill_super(struct super_block *sb, struct fs_context *fc,
void (*setup)(struct super_block *));
extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
struct inode *i2);
extern const struct fs_parameter_spec fat_param_spec[];
int fat_init_fs_context(struct fs_context *fc, bool is_vfat);
void fat_free_fc(struct fs_context *fc);
int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
bool is_vfat);
int fat_reconfigure(struct fs_context *fc);
static inline unsigned long fat_dir_hash(int logstart)
{
return hash_32(logstart, FAT_HASH_BITS);
}
extern int fat_add_cluster(struct inode *inode);
/* fat/misc.c */
extern __printf(3, 4) __cold
void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
#define fat_fs_error(sb, fmt, args...) \
__fat_fs_error(sb, 1, fmt , ## args)
#define fat_fs_error_ratelimit(sb, fmt, args...) \
__fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
#define FAT_PRINTK_PREFIX "%sFAT-fs (%s): "
#define fat_msg(sb, level, fmt, args...) \
do { \
printk_index_subsys_emit(FAT_PRINTK_PREFIX, level, fmt, ##args);\
_fat_msg(sb, level, fmt, ##args); \
} while (0)
__printf(3, 4) __cold
void _fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
#define fat_msg_ratelimit(sb, level, fmt, args...) \
do { \
if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
fat_msg(sb, level, fmt, ## args); \
} while (0)
extern int fat_clusters_flush(struct super_block *sb);
extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec64 *ts,
__le16 __time, __le16 __date, u8 time_cs);
extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts,
__le16 *time, __le16 *date, u8 *time_cs);
extern struct timespec64 fat_truncate_atime(const struct msdos_sb_info *sbi,
const struct timespec64 *ts);
extern struct timespec64 fat_truncate_mtime(const struct msdos_sb_info *sbi,
const struct timespec64 *ts);
extern int fat_truncate_time(struct inode *inode, struct timespec64 *now,
int flags);
extern int fat_update_time(struct inode *inode, int flags);
extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
int fat_cache_init(void);
void fat_cache_destroy(void);
/* fat/nfs.c */
extern const struct export_operations fat_export_ops;
extern const struct export_operations fat_export_ops_nostale;
/* helper for printk */
typedef unsigned long long llu;
#endif /* !_FAT_H */
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