[linux.git] / fs / fat / fat.h

/* 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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
9e975dae OH	2	#ifndef _FAT_H
	3	#define _FAT_H
	4
	5	#include <linux/buffer_head.h>
9e975dae	6	#include <linux/nls.h>
7669e8fb	7	#include <linux/hash.h>
aaa04b48	8	#include <linux/ratelimit.h>
9e975dae	9	#include <linux/msdos_fs.h>
634440b6 ES	10	#include <linux/fs_context.h>
634440b6 ES	11	#include <linux/fs_parser.h>
9e975dae OH	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
85c78591 DK	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
2628b7a6 NJ	26	#define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */
	27	#define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */
	28
9e975dae	29	struct fat_mount_options {
170782eb EB	30	kuid_t fs_uid;
170782eb EB	31	kgid_t fs_gid;
9e975dae OH	32	unsigned short fs_fmask;
9e975dae OH	33	unsigned short fs_dmask;
4a3aeb13	34	unsigned short codepage; /* Codepage for shortname conversions */
58156c8f	35	int time_offset; /* Offset of timestamps from UTC (in minutes) */
4a3aeb13 CJB	36	char iocharset; / Charset used for filename input/display */
	37	unsigned short shortname; /* flags for shortname display/create rule */
	38	unsigned char name_check; /* r = relaxed, n = normal, s = strict */
	39	unsigned char errors; /* On error: continue, panic, remount-ro */
2628b7a6	40	unsigned char nfs; /* NFS support: nostale_ro, stale_rw */
9e975dae	41	unsigned short allow_utime;/* permission for setting the [am]time */
4a3aeb13 CJB	42	unsigned quiet:1, /* set = fake successful chmods and chowns */
	43	showexec:1, /* set = only set x bit for com/exe/bat */
	44	sys_immutable:1, /* set = system files are immutable */
	45	dotsOK:1, /* set = hidden and system files are named '.filename' */
	46	isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
	47	utf8:1, /* Use of UTF-8 character set (Default) */
	48	unicode_xlate:1, /* create escape sequences for unhandled Unicode */
	49	numtail:1, /* Does first alias have a numeric '~1' type tail? */
	50	flush:1, /* write things quickly */
	51	nocase:1, /* Does this need case conversion? 0=need case conversion*/
	52	usefree:1, /* Use free_clusters for FAT32 */
58156c8f	53	tz_set:1, /* Filesystem timestamps' offset set */
4a3aeb13	54	rodir:1, /* allow ATTR_RO for directory */
190a8843	55	discard:1, /* Issue discard requests on deletions */
206d3d8e ES	56	dos1xfloppy:1, /* Assume default BPB for DOS 1.x floppies */
206d3d8e ES	57	debug:1; /* Not currently used */
9e975dae OH	58	};
	59
	60	#define FAT_HASH_BITS 8
	61	#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
9e975dae OH	62
	63	/*
	64	* MS-DOS file system in-core superblock data
	65	*/
	66	struct msdos_sb_info {
4a3aeb13 CJB	67	unsigned short sec_per_clus; /* sectors/cluster */
	68	unsigned short cluster_bits; /* log2(cluster_size) */
	69	unsigned int cluster_size; /* cluster size */
8de560de	70	unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */
9e975dae	71	unsigned short fat_start;
4a3aeb13	72	unsigned long fat_length; /* FAT start & length (sec.) */
9e975dae	73	unsigned long dir_start;
4a3aeb13 CJB	74	unsigned short dir_entries; /* root dir start & entries */
	75	unsigned long data_start; /* first data sector */
	76	unsigned long max_cluster; /* maximum cluster number */
	77	unsigned long root_cluster; /* first cluster of the root directory */
	78	unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
9e975dae	79	struct mutex fat_lock;
8fceb4e0	80	struct mutex nfs_build_inode_lock;
e40b34c7 MS	81	struct mutex s_lock;
	82	unsigned int prev_free; /* previously allocated cluster number */
	83	unsigned int free_clusters; /* -1 if undefined */
9e975dae OH	84	unsigned int free_clus_valid; /* is free_clusters valid? */
9e975dae OH	85	struct fat_mount_options options;
4a3aeb13 CJB	86	struct nls_table nls_disk; / Codepage used on disk */
	87	struct nls_table nls_io; / Charset used for input and display */
	88	const void dir_ops; / Opaque; default directory operations */
	89	int dir_per_block; /* dir entries per block */
	90	int dir_per_block_bits; /* log2(dir_per_block) */
6e5b93ee	91	unsigned int vol_id; /volume ID/
9e975dae OH	92
9e975dae OH	93	int fatent_shift;
8992de4c	94	const struct fatent_operations *fatent_ops;
b522412a	95	struct inode *fat_inode;
020ac5b6	96	struct inode *fsinfo_inode;
9e975dae	97
aaa04b48 OH	98	struct ratelimit_state ratelimit;
aaa04b48 OH	99
9e975dae OH	100	spinlock_t inode_hash_lock;
9e975dae OH	101	struct hlist_head inode_hashtable[FAT_HASH_SIZE];
7669e8fb SM	102
	103	spinlock_t dir_hash_lock;
	104	struct hlist_head dir_hashtable[FAT_HASH_SIZE];
b88a1058 OR	105
b88a1058 OR	106	unsigned int dirty; /* fs state before mount */
cac45b06	107	struct rcu_head rcu;
9e975dae OH	108	};
	109
	110	#define FAT_CACHE_VALID 0 /* special case for valid cache */
	111
	112	/*
	113	* MS-DOS file system inode data in memory
	114	*/
	115	struct msdos_inode_info {
	116	spinlock_t cache_lru_lock;
	117	struct list_head cache_lru;
	118	int nr_caches;
	119	/* for avoiding the race between fat_free() and fat_get_cluster() */
	120	unsigned int cache_valid_id;
	121
2bdf67eb OH	122	/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
	123	loff_t mmu_private; /* physically allocated size */
	124
9e975dae OH	125	int i_start; /* first cluster or 0 */
	126	int i_logstart; /* logical first cluster */
	127	int i_attrs; /* unused attribute bits */
	128	loff_t i_pos; /* on-disk position of directory entry or 0 */
	129	struct hlist_node i_fat_hash; /* hash by i_location */
7669e8fb	130	struct hlist_node i_dir_hash; /* hash by i_logstart */
58268691	131	struct rw_semaphore truncate_lock; /* protect bmap against truncate */
30abce05	132	struct timespec64 i_crtime; /* File creation (birth) time */
9e975dae OH	133	struct inode vfs_inode;
	134	};
	135
	136	struct fat_slot_info {
	137	loff_t i_pos; /* on-disk position of directory entry */
	138	loff_t slot_off; /* offset for slot or de start */
	139	int nr_slots; /* number of slots + 1(de) in filename */
	140	struct msdos_dir_entry *de;
	141	struct buffer_head *bh;
	142	};
	143
	144	static inline struct msdos_sb_info MSDOS_SB(struct super_block sb)
	145	{
	146	return sb->s_fs_info;
	147	}
	148
306790f7 CT	149	/*
	150	* Functions that determine the variant of the FAT file system (i.e.,
	151	* whether this is FAT12, FAT16 or FAT32.
	152	*/
	153	static inline bool is_fat12(const struct msdos_sb_info *sbi)
	154	{
	155	return sbi->fat_bits == 12;
	156	}
	157
	158	static inline bool is_fat16(const struct msdos_sb_info *sbi)
	159	{
	160	return sbi->fat_bits == 16;
	161	}
	162
	163	static inline bool is_fat32(const struct msdos_sb_info *sbi)
	164	{
	165	return sbi->fat_bits == 32;
	166	}
	167
d19dc016 CT	168	/* Maximum number of clusters */
	169	static inline u32 max_fat(struct super_block *sb)
	170	{
	171	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	172
306790f7 CT	173	return is_fat32(sbi) ? MAX_FAT32 :
306790f7 CT	174	is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12;
d19dc016 CT	175	}
d19dc016 CT	176
9e975dae OH	177	static inline struct msdos_inode_info MSDOS_I(struct inode inode)
	178	{
	179	return container_of(inode, struct msdos_inode_info, vfs_inode);
	180	}
	181
9183482f OH	182	/*
	183	* If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
	184	* save ATTR_RO instead of ->i_mode.
dfc209c0 OH	185	*
	186	* If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
	187	* bit, it's just used as flag for app.
9183482f OH	188	*/
	189	static inline int fat_mode_can_hold_ro(struct inode *inode)
	190	{
	191	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
dacd0e7b	192	umode_t mask;
9183482f	193
dfc209c0 OH	194	if (S_ISDIR(inode->i_mode)) {
	195	if (!sbi->options.rodir)
	196	return 0;
9183482f	197	mask = ~sbi->options.fs_dmask;
dfc209c0	198	} else
9183482f OH	199	mask = ~sbi->options.fs_fmask;
	200
	201	if (!(mask & S_IWUGO))
	202	return 0;
	203	return 1;
	204	}
	205
9c0aa1b8	206	/* Convert attribute bits and a mask to the UNIX mode. */
dacd0e7b AV	207	static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
dacd0e7b AV	208	u8 attrs, umode_t mode)
9c0aa1b8	209	{
dfc209c0	210	if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
9c0aa1b8 OH	211	mode &= ~S_IWUGO;
	212
	213	if (attrs & ATTR_DIR)
	214	return (mode & ~sbi->options.fs_dmask) \| S_IFDIR;
	215	else
	216	return (mode & ~sbi->options.fs_fmask) \| S_IFREG;
	217	}
	218
9e975dae	219	/* Return the FAT attribute byte for this inode */
9c0aa1b8	220	static inline u8 fat_make_attrs(struct inode *inode)
9e975dae	221	{
9183482f OH	222	u8 attrs = MSDOS_I(inode)->i_attrs;
	223	if (S_ISDIR(inode->i_mode))
	224	attrs \|= ATTR_DIR;
	225	if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
	226	attrs \|= ATTR_RO;
	227	return attrs;
9e975dae OH	228	}
9e975dae OH	229
9c0aa1b8 OH	230	static inline void fat_save_attrs(struct inode *inode, u8 attrs)
9c0aa1b8 OH	231	{
9183482f OH	232	if (fat_mode_can_hold_ro(inode))
	233	MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
	234	else
	235	MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED \| ATTR_RO);
9c0aa1b8 OH	236	}
9c0aa1b8 OH	237
9e975dae OH	238	static inline unsigned char fat_checksum(const __u8 *name)
	239	{
	240	unsigned char s = name[0];
	241	s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
	242	s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
	243	s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
	244	s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
	245	s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
	246	return s;
	247	}
	248
	249	static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
	250	{
	251	return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
	252	+ sbi->data_start;
	253	}
	254
e22a4442 NJ	255	static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
	256	loff_t i_pos, sector_t blknr, int offset)
	257	{
	258	*blknr = i_pos >> sbi->dir_per_block_bits;
	259	*offset = i_pos & (sbi->dir_per_block - 1);
	260	}
	261
f21735d5 NJ	262	static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
	263	struct inode *inode)
	264	{
	265	loff_t i_pos;
	266	#if BITS_PER_LONG == 32
	267	spin_lock(&sbi->inode_hash_lock);
	268	#endif
	269	i_pos = MSDOS_I(inode)->i_pos;
	270	#if BITS_PER_LONG == 32
	271	spin_unlock(&sbi->inode_hash_lock);
	272	#endif
	273	return i_pos;
	274	}
	275
9e975dae OH	276	static inline void fat16_towchar(wchar_t dst, const __u8 src, size_t len)
	277	{
	278	#ifdef __BIG_ENDIAN
	279	while (len--) {
	280	*dst++ = src[0] \| (src[1] << 8);
	281	src += 2;
	282	}
	283	#else
	284	memcpy(dst, src, len * 2);
	285	#endif
	286	}
	287
a943ed71 SM	288	static inline int fat_get_start(const struct msdos_sb_info *sbi,
	289	const struct msdos_dir_entry *de)
	290	{
	291	int cluster = le16_to_cpu(de->start);
306790f7	292	if (is_fat32(sbi))
a943ed71 SM	293	cluster \|= (le16_to_cpu(de->starthi) << 16);
	294	return cluster;
	295	}
	296
	297	static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
	298	{
	299	de->start = cpu_to_le16(cluster);
	300	de->starthi = cpu_to_le16(cluster >> 16);
	301	}
	302
9e975dae OH	303	static inline void fatwchar_to16(__u8 dst, const wchar_t src, size_t len)
	304	{
	305	#ifdef __BIG_ENDIAN
	306	while (len--) {
	307	dst[0] = *src & 0x00FF;
	308	dst[1] = (*src & 0xFF00) >> 8;
	309	dst += 2;
	310	src++;
	311	}
	312	#else
	313	memcpy(dst, src, len * 2);
	314	#endif
	315	}
	316
	317	/* fat/cache.c */
	318	extern void fat_cache_inval_inode(struct inode *inode);
	319	extern int fat_get_cluster(struct inode *inode, int cluster,
	320	int fclus, int dclus);
16fab201 NJ	321	extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector,
	322	sector_t last_block,
	323	unsigned long mapped_blocks, sector_t bmap);
9e975dae	324	extern int fat_bmap(struct inode inode, sector_t sector, sector_t phys,
16fab201	325	unsigned long *mapped_blocks, int create, bool from_bmap);
9e975dae OH	326
	327	/* fat/dir.c */
	328	extern const struct file_operations fat_dir_operations;
	329	extern int fat_search_long(struct inode inode, const unsigned char name,
	330	int name_len, struct fat_slot_info *sinfo);
	331	extern int fat_dir_empty(struct inode *dir);
	332	extern int fat_subdirs(struct inode *dir);
	333	extern int fat_scan(struct inode dir, const unsigned char name,
	334	struct fat_slot_info *sinfo);
f1e6fb0a NJ	335	extern int fat_scan_logstart(struct inode *dir, int i_logstart,
f1e6fb0a NJ	336	struct fat_slot_info *sinfo);
9e975dae	337	extern int fat_get_dotdot_entry(struct inode dir, struct buffer_head *bh,
7669e8fb	338	struct msdos_dir_entry **de);
f423420c	339	extern int fat_alloc_new_dir(struct inode dir, struct timespec64 ts);
9e975dae OH	340	extern int fat_add_entries(struct inode dir, void slots, int nr_slots,
	341	struct fat_slot_info *sinfo);
	342	extern int fat_remove_entries(struct inode dir, struct fat_slot_info sinfo);
	343
	344	/* fat/fatent.c */
	345	struct fat_entry {
	346	int entry;
	347	union {
	348	u8 *ent12_p[2];
	349	__le16 *ent16_p;
	350	__le32 *ent32_p;
	351	} u;
	352	int nr_bhs;
	353	struct buffer_head *bhs[2];
b522412a	354	struct inode *fat_inode;
9e975dae OH	355	};
	356
	357	static inline void fatent_init(struct fat_entry *fatent)
	358	{
	359	fatent->nr_bhs = 0;
	360	fatent->entry = 0;
	361	fatent->u.ent32_p = NULL;
	362	fatent->bhs[0] = fatent->bhs[1] = NULL;
b522412a	363	fatent->fat_inode = NULL;
9e975dae OH	364	}
	365
	366	static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
	367	{
	368	fatent->entry = entry;
	369	fatent->u.ent32_p = NULL;
	370	}
	371
	372	static inline void fatent_brelse(struct fat_entry *fatent)
	373	{
	374	int i;
	375	fatent->u.ent32_p = NULL;
	376	for (i = 0; i < fatent->nr_bhs; i++)
	377	brelse(fatent->bhs[i]);
	378	fatent->nr_bhs = 0;
	379	fatent->bhs[0] = fatent->bhs[1] = NULL;
b522412a	380	fatent->fat_inode = NULL;
9e975dae OH	381	}
9e975dae OH	382
0afa9626 OH	383	static inline bool fat_valid_entry(struct msdos_sb_info *sbi, int entry)
	384	{
	385	return FAT_START_ENT <= entry && entry < sbi->max_cluster;
	386	}
	387
9e975dae OH	388	extern void fat_ent_access_init(struct super_block *sb);
	389	extern int fat_ent_read(struct inode inode, struct fat_entry fatent,
	390	int entry);
	391	extern int fat_ent_write(struct inode inode, struct fat_entry fatent,
	392	int new, int wait);
	393	extern int fat_alloc_clusters(struct inode inode, int cluster,
	394	int nr_cluster);
	395	extern int fat_free_clusters(struct inode *inode, int cluster);
	396	extern int fat_count_free_clusters(struct super_block *sb);
f663b5b3	397	extern int fat_trim_fs(struct inode inode, struct fstrim_range range);
9e975dae OH	398
9e975dae OH	399	/* fat/file.c */
7845bc3e AB	400	extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
7845bc3e AB	401	unsigned long arg);
9e975dae OH	402	extern const struct file_operations fat_file_operations;
9e975dae OH	403	extern const struct inode_operations fat_file_inode_operations;
c1632a0f	404	extern int fat_setattr(struct mnt_idmap idmap, struct dentry dentry,
549c7297	405	struct iattr *attr);
459f6ed3	406	extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
b74d24f7	407	extern int fat_getattr(struct mnt_idmap *idmap,
549c7297	408	const struct path path, struct kstat stat,
a528d35e	409	u32 request_mask, unsigned int flags);
02c24a82 JB	410	extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
02c24a82 JB	411	int datasync);
9e975dae OH	412
9e975dae OH	413	/* fat/inode.c */
c0ef0cc9	414	extern int fat_block_truncate_page(struct inode *inode, loff_t from);
9e975dae OH	415	extern void fat_attach(struct inode *inode, loff_t i_pos);
	416	extern void fat_detach(struct inode *inode);
	417	extern struct inode fat_iget(struct super_block sb, loff_t i_pos);
	418	extern struct inode fat_build_inode(struct super_block sb,
	419	struct msdos_dir_entry *de, loff_t i_pos);
	420	extern int fat_sync_inode(struct inode *inode);
634440b6 ES	421	extern int fat_fill_super(struct super_block sb, struct fs_context fc,
634440b6 ES	422	void (setup)(struct super_block ));
f1e6fb0a	423	extern int fat_fill_inode(struct inode inode, struct msdos_dir_entry de);
9e975dae OH	424
9e975dae OH	425	extern int fat_flush_inodes(struct super_block sb, struct inode i1,
d5a4a386	426	struct inode *i2);
634440b6 ES	427
	428	extern const struct fs_parameter_spec fat_param_spec[];
	429	int fat_init_fs_context(struct fs_context *fc, bool is_vfat);
	430	void fat_free_fc(struct fs_context *fc);
	431
	432	int fat_parse_param(struct fs_context fc, struct fs_parameter param,
	433	bool is_vfat);
	434	int fat_reconfigure(struct fs_context *fc);
	435
7669e8fb	436	static inline unsigned long fat_dir_hash(int logstart)
21b6633d	437	{
7669e8fb	438	return hash_32(logstart, FAT_HASH_BITS);
21b6633d	439	}
b13bb33e	440	extern int fat_add_cluster(struct inode *inode);
21b6633d	441
9e975dae	442	/* fat/misc.c */
b9075fa9 JP	443	extern __printf(3, 4) __cold
b9075fa9 JP	444	void __fat_fs_error(struct super_block sb, int report, const char fmt, ...);
2c8a5ffb OR	445	#define fat_fs_error(sb, fmt, args...) \
	446	__fat_fs_error(sb, 1, fmt , ## args)
	447	#define fat_fs_error_ratelimit(sb, fmt, args...) \
	448	__fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
e057aaec JL	449
	450	#define FAT_PRINTK_PREFIX "%sFAT-fs (%s): "
	451	#define fat_msg(sb, level, fmt, args...) \
	452	do { \
	453	printk_index_subsys_emit(FAT_PRINTK_PREFIX, level, fmt, ##args);\
	454	_fat_msg(sb, level, fmt, ##args); \
	455	} while (0)
b9075fa9	456	__printf(3, 4) __cold
e057aaec	457	void _fat_msg(struct super_block sb, const char level, const char *fmt, ...);
b742c341 NJ	458	#define fat_msg_ratelimit(sb, level, fmt, args...) \
	459	do { \
	460	if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
	461	fat_msg(sb, level, fmt, ## args); \
	462	} while (0)
ed248b29	463	extern int fat_clusters_flush(struct super_block *sb);
9e975dae	464	extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
f423420c	465	extern void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec64 ts,
7decd1cb	466	__le16 __time, __le16 __date, u8 time_cs);
f423420c	467	extern void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec64 ts,
7decd1cb	468	__le16 time, __le16 date, u8 *time_cs);
4dcc3f96 CCC	469	extern struct timespec64 fat_truncate_atime(const struct msdos_sb_info *sbi,
4dcc3f96 CCC	470	const struct timespec64 *ts);
4dcc3f96 CCC	471	extern struct timespec64 fat_truncate_mtime(const struct msdos_sb_info *sbi,
4dcc3f96 CCC	472	const struct timespec64 *ts);
6bb885ec FS	473	extern int fat_truncate_time(struct inode inode, struct timespec64 now,
6bb885ec FS	474	int flags);
913e9928	475	extern int fat_update_time(struct inode *inode, int flags);
9e975dae OH	476	extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
	477
	478	int fat_cache_init(void);
	479	void fat_cache_destroy(void);
	480
21b6633d	481	/* fat/nfs.c */
ea3983ac NJ	482	extern const struct export_operations fat_export_ops;
ea3983ac NJ	483	extern const struct export_operations fat_export_ops_nostale;
21b6633d	484
c3302931 OH	485	/* helper for printk */
	486	typedef unsigned long long llu;
	487
9e975dae	488	#endif /* !_FAT_H */