[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>

/*
 * 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 */
};

#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, void *data, int silent,
			  int isvfat, 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);
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 OH	9	#include <linux/msdos_fs.h>
	10
	11	/*
	12	* vfat shortname flags
	13	*/
	14	#define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
	15	#define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
	16	#define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
	17	#define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
	18	#define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
	19
85c78591 DK	20	#define FAT_ERRORS_CONT 1 /* ignore error and continue */
	21	#define FAT_ERRORS_PANIC 2 /* panic on error */
	22	#define FAT_ERRORS_RO 3 /* remount r/o on error */
	23
2628b7a6 NJ	24	#define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */
	25	#define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */
	26
9e975dae	27	struct fat_mount_options {
170782eb EB	28	kuid_t fs_uid;
170782eb EB	29	kgid_t fs_gid;
9e975dae OH	30	unsigned short fs_fmask;
9e975dae OH	31	unsigned short fs_dmask;
4a3aeb13	32	unsigned short codepage; /* Codepage for shortname conversions */
58156c8f	33	int time_offset; /* Offset of timestamps from UTC (in minutes) */
4a3aeb13 CJB	34	char iocharset; / Charset used for filename input/display */
	35	unsigned short shortname; /* flags for shortname display/create rule */
	36	unsigned char name_check; /* r = relaxed, n = normal, s = strict */
	37	unsigned char errors; /* On error: continue, panic, remount-ro */
2628b7a6	38	unsigned char nfs; /* NFS support: nostale_ro, stale_rw */
9e975dae	39	unsigned short allow_utime;/* permission for setting the [am]time */
4a3aeb13 CJB	40	unsigned quiet:1, /* set = fake successful chmods and chowns */
	41	showexec:1, /* set = only set x bit for com/exe/bat */
	42	sys_immutable:1, /* set = system files are immutable */
	43	dotsOK:1, /* set = hidden and system files are named '.filename' */
	44	isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
	45	utf8:1, /* Use of UTF-8 character set (Default) */
	46	unicode_xlate:1, /* create escape sequences for unhandled Unicode */
	47	numtail:1, /* Does first alias have a numeric '~1' type tail? */
	48	flush:1, /* write things quickly */
	49	nocase:1, /* Does this need case conversion? 0=need case conversion*/
	50	usefree:1, /* Use free_clusters for FAT32 */
58156c8f	51	tz_set:1, /* Filesystem timestamps' offset set */
4a3aeb13	52	rodir:1, /* allow ATTR_RO for directory */
190a8843 CM	53	discard:1, /* Issue discard requests on deletions */
190a8843 CM	54	dos1xfloppy:1; /* Assume default BPB for DOS 1.x floppies */
9e975dae OH	55	};
	56
	57	#define FAT_HASH_BITS 8
	58	#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
9e975dae OH	59
	60	/*
	61	* MS-DOS file system in-core superblock data
	62	*/
	63	struct msdos_sb_info {
4a3aeb13 CJB	64	unsigned short sec_per_clus; /* sectors/cluster */
	65	unsigned short cluster_bits; /* log2(cluster_size) */
	66	unsigned int cluster_size; /* cluster size */
8de560de	67	unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */
9e975dae	68	unsigned short fat_start;
4a3aeb13	69	unsigned long fat_length; /* FAT start & length (sec.) */
9e975dae	70	unsigned long dir_start;
4a3aeb13 CJB	71	unsigned short dir_entries; /* root dir start & entries */
	72	unsigned long data_start; /* first data sector */
	73	unsigned long max_cluster; /* maximum cluster number */
	74	unsigned long root_cluster; /* first cluster of the root directory */
	75	unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
9e975dae	76	struct mutex fat_lock;
8fceb4e0	77	struct mutex nfs_build_inode_lock;
e40b34c7 MS	78	struct mutex s_lock;
	79	unsigned int prev_free; /* previously allocated cluster number */
	80	unsigned int free_clusters; /* -1 if undefined */
9e975dae OH	81	unsigned int free_clus_valid; /* is free_clusters valid? */
9e975dae OH	82	struct fat_mount_options options;
4a3aeb13 CJB	83	struct nls_table nls_disk; / Codepage used on disk */
	84	struct nls_table nls_io; / Charset used for input and display */
	85	const void dir_ops; / Opaque; default directory operations */
	86	int dir_per_block; /* dir entries per block */
	87	int dir_per_block_bits; /* log2(dir_per_block) */
6e5b93ee	88	unsigned int vol_id; /volume ID/
9e975dae OH	89
9e975dae OH	90	int fatent_shift;
8992de4c	91	const struct fatent_operations *fatent_ops;
b522412a	92	struct inode *fat_inode;
020ac5b6	93	struct inode *fsinfo_inode;
9e975dae	94
aaa04b48 OH	95	struct ratelimit_state ratelimit;
aaa04b48 OH	96
9e975dae OH	97	spinlock_t inode_hash_lock;
9e975dae OH	98	struct hlist_head inode_hashtable[FAT_HASH_SIZE];
7669e8fb SM	99
	100	spinlock_t dir_hash_lock;
	101	struct hlist_head dir_hashtable[FAT_HASH_SIZE];
b88a1058 OR	102
b88a1058 OR	103	unsigned int dirty; /* fs state before mount */
cac45b06	104	struct rcu_head rcu;
9e975dae OH	105	};
	106
	107	#define FAT_CACHE_VALID 0 /* special case for valid cache */
	108
	109	/*
	110	* MS-DOS file system inode data in memory
	111	*/
	112	struct msdos_inode_info {
	113	spinlock_t cache_lru_lock;
	114	struct list_head cache_lru;
	115	int nr_caches;
	116	/* for avoiding the race between fat_free() and fat_get_cluster() */
	117	unsigned int cache_valid_id;
	118
2bdf67eb OH	119	/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
	120	loff_t mmu_private; /* physically allocated size */
	121
9e975dae OH	122	int i_start; /* first cluster or 0 */
	123	int i_logstart; /* logical first cluster */
	124	int i_attrs; /* unused attribute bits */
	125	loff_t i_pos; /* on-disk position of directory entry or 0 */
	126	struct hlist_node i_fat_hash; /* hash by i_location */
7669e8fb	127	struct hlist_node i_dir_hash; /* hash by i_logstart */
58268691	128	struct rw_semaphore truncate_lock; /* protect bmap against truncate */
30abce05	129	struct timespec64 i_crtime; /* File creation (birth) time */
9e975dae OH	130	struct inode vfs_inode;
	131	};
	132
	133	struct fat_slot_info {
	134	loff_t i_pos; /* on-disk position of directory entry */
	135	loff_t slot_off; /* offset for slot or de start */
	136	int nr_slots; /* number of slots + 1(de) in filename */
	137	struct msdos_dir_entry *de;
	138	struct buffer_head *bh;
	139	};
	140
	141	static inline struct msdos_sb_info MSDOS_SB(struct super_block sb)
	142	{
	143	return sb->s_fs_info;
	144	}
	145
306790f7 CT	146	/*
	147	* Functions that determine the variant of the FAT file system (i.e.,
	148	* whether this is FAT12, FAT16 or FAT32.
	149	*/
	150	static inline bool is_fat12(const struct msdos_sb_info *sbi)
	151	{
	152	return sbi->fat_bits == 12;
	153	}
	154
	155	static inline bool is_fat16(const struct msdos_sb_info *sbi)
	156	{
	157	return sbi->fat_bits == 16;
	158	}
	159
	160	static inline bool is_fat32(const struct msdos_sb_info *sbi)
	161	{
	162	return sbi->fat_bits == 32;
	163	}
	164
d19dc016 CT	165	/* Maximum number of clusters */
	166	static inline u32 max_fat(struct super_block *sb)
	167	{
	168	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	169
306790f7 CT	170	return is_fat32(sbi) ? MAX_FAT32 :
306790f7 CT	171	is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12;
d19dc016 CT	172	}
d19dc016 CT	173
9e975dae OH	174	static inline struct msdos_inode_info MSDOS_I(struct inode inode)
	175	{
	176	return container_of(inode, struct msdos_inode_info, vfs_inode);
	177	}
	178
9183482f OH	179	/*
	180	* If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
	181	* save ATTR_RO instead of ->i_mode.
dfc209c0 OH	182	*
	183	* If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
	184	* bit, it's just used as flag for app.
9183482f OH	185	*/
	186	static inline int fat_mode_can_hold_ro(struct inode *inode)
	187	{
	188	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
dacd0e7b	189	umode_t mask;
9183482f	190
dfc209c0 OH	191	if (S_ISDIR(inode->i_mode)) {
	192	if (!sbi->options.rodir)
	193	return 0;
9183482f	194	mask = ~sbi->options.fs_dmask;
dfc209c0	195	} else
9183482f OH	196	mask = ~sbi->options.fs_fmask;
	197
	198	if (!(mask & S_IWUGO))
	199	return 0;
	200	return 1;
	201	}
	202
9c0aa1b8	203	/* Convert attribute bits and a mask to the UNIX mode. */
dacd0e7b AV	204	static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
dacd0e7b AV	205	u8 attrs, umode_t mode)
9c0aa1b8	206	{
dfc209c0	207	if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
9c0aa1b8 OH	208	mode &= ~S_IWUGO;
	209
	210	if (attrs & ATTR_DIR)
	211	return (mode & ~sbi->options.fs_dmask) \| S_IFDIR;
	212	else
	213	return (mode & ~sbi->options.fs_fmask) \| S_IFREG;
	214	}
	215
9e975dae	216	/* Return the FAT attribute byte for this inode */
9c0aa1b8	217	static inline u8 fat_make_attrs(struct inode *inode)
9e975dae	218	{
9183482f OH	219	u8 attrs = MSDOS_I(inode)->i_attrs;
	220	if (S_ISDIR(inode->i_mode))
	221	attrs \|= ATTR_DIR;
	222	if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
	223	attrs \|= ATTR_RO;
	224	return attrs;
9e975dae OH	225	}
9e975dae OH	226
9c0aa1b8 OH	227	static inline void fat_save_attrs(struct inode *inode, u8 attrs)
9c0aa1b8 OH	228	{
9183482f OH	229	if (fat_mode_can_hold_ro(inode))
	230	MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
	231	else
	232	MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED \| ATTR_RO);
9c0aa1b8 OH	233	}
9c0aa1b8 OH	234
9e975dae OH	235	static inline unsigned char fat_checksum(const __u8 *name)
	236	{
	237	unsigned char s = name[0];
	238	s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
	239	s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
	240	s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
	241	s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
	242	s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
	243	return s;
	244	}
	245
	246	static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
	247	{
	248	return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
	249	+ sbi->data_start;
	250	}
	251
e22a4442 NJ	252	static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
	253	loff_t i_pos, sector_t blknr, int offset)
	254	{
	255	*blknr = i_pos >> sbi->dir_per_block_bits;
	256	*offset = i_pos & (sbi->dir_per_block - 1);
	257	}
	258
f21735d5 NJ	259	static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
	260	struct inode *inode)
	261	{
	262	loff_t i_pos;
	263	#if BITS_PER_LONG == 32
	264	spin_lock(&sbi->inode_hash_lock);
	265	#endif
	266	i_pos = MSDOS_I(inode)->i_pos;
	267	#if BITS_PER_LONG == 32
	268	spin_unlock(&sbi->inode_hash_lock);
	269	#endif
	270	return i_pos;
	271	}
	272
9e975dae OH	273	static inline void fat16_towchar(wchar_t dst, const __u8 src, size_t len)
	274	{
	275	#ifdef __BIG_ENDIAN
	276	while (len--) {
	277	*dst++ = src[0] \| (src[1] << 8);
	278	src += 2;
	279	}
	280	#else
	281	memcpy(dst, src, len * 2);
	282	#endif
	283	}
	284
a943ed71 SM	285	static inline int fat_get_start(const struct msdos_sb_info *sbi,
	286	const struct msdos_dir_entry *de)
	287	{
	288	int cluster = le16_to_cpu(de->start);
306790f7	289	if (is_fat32(sbi))
a943ed71 SM	290	cluster \|= (le16_to_cpu(de->starthi) << 16);
	291	return cluster;
	292	}
	293
	294	static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
	295	{
	296	de->start = cpu_to_le16(cluster);
	297	de->starthi = cpu_to_le16(cluster >> 16);
	298	}
	299
9e975dae OH	300	static inline void fatwchar_to16(__u8 dst, const wchar_t src, size_t len)
	301	{
	302	#ifdef __BIG_ENDIAN
	303	while (len--) {
	304	dst[0] = *src & 0x00FF;
	305	dst[1] = (*src & 0xFF00) >> 8;
	306	dst += 2;
	307	src++;
	308	}
	309	#else
	310	memcpy(dst, src, len * 2);
	311	#endif
	312	}
	313
	314	/* fat/cache.c */
	315	extern void fat_cache_inval_inode(struct inode *inode);
	316	extern int fat_get_cluster(struct inode *inode, int cluster,
	317	int fclus, int dclus);
16fab201 NJ	318	extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector,
	319	sector_t last_block,
	320	unsigned long mapped_blocks, sector_t bmap);
9e975dae	321	extern int fat_bmap(struct inode inode, sector_t sector, sector_t phys,
16fab201	322	unsigned long *mapped_blocks, int create, bool from_bmap);
9e975dae OH	323
	324	/* fat/dir.c */
	325	extern const struct file_operations fat_dir_operations;
	326	extern int fat_search_long(struct inode inode, const unsigned char name,
	327	int name_len, struct fat_slot_info *sinfo);
	328	extern int fat_dir_empty(struct inode *dir);
	329	extern int fat_subdirs(struct inode *dir);
	330	extern int fat_scan(struct inode dir, const unsigned char name,
	331	struct fat_slot_info *sinfo);
f1e6fb0a NJ	332	extern int fat_scan_logstart(struct inode *dir, int i_logstart,
f1e6fb0a NJ	333	struct fat_slot_info *sinfo);
9e975dae	334	extern int fat_get_dotdot_entry(struct inode dir, struct buffer_head *bh,
7669e8fb	335	struct msdos_dir_entry **de);
f423420c	336	extern int fat_alloc_new_dir(struct inode dir, struct timespec64 ts);
9e975dae OH	337	extern int fat_add_entries(struct inode dir, void slots, int nr_slots,
	338	struct fat_slot_info *sinfo);
	339	extern int fat_remove_entries(struct inode dir, struct fat_slot_info sinfo);
	340
	341	/* fat/fatent.c */
	342	struct fat_entry {
	343	int entry;
	344	union {
	345	u8 *ent12_p[2];
	346	__le16 *ent16_p;
	347	__le32 *ent32_p;
	348	} u;
	349	int nr_bhs;
	350	struct buffer_head *bhs[2];
b522412a	351	struct inode *fat_inode;
9e975dae OH	352	};
	353
	354	static inline void fatent_init(struct fat_entry *fatent)
	355	{
	356	fatent->nr_bhs = 0;
	357	fatent->entry = 0;
	358	fatent->u.ent32_p = NULL;
	359	fatent->bhs[0] = fatent->bhs[1] = NULL;
b522412a	360	fatent->fat_inode = NULL;
9e975dae OH	361	}
	362
	363	static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
	364	{
	365	fatent->entry = entry;
	366	fatent->u.ent32_p = NULL;
	367	}
	368
	369	static inline void fatent_brelse(struct fat_entry *fatent)
	370	{
	371	int i;
	372	fatent->u.ent32_p = NULL;
	373	for (i = 0; i < fatent->nr_bhs; i++)
	374	brelse(fatent->bhs[i]);
	375	fatent->nr_bhs = 0;
	376	fatent->bhs[0] = fatent->bhs[1] = NULL;
b522412a	377	fatent->fat_inode = NULL;
9e975dae OH	378	}
9e975dae OH	379
0afa9626 OH	380	static inline bool fat_valid_entry(struct msdos_sb_info *sbi, int entry)
	381	{
	382	return FAT_START_ENT <= entry && entry < sbi->max_cluster;
	383	}
	384
9e975dae OH	385	extern void fat_ent_access_init(struct super_block *sb);
	386	extern int fat_ent_read(struct inode inode, struct fat_entry fatent,
	387	int entry);
	388	extern int fat_ent_write(struct inode inode, struct fat_entry fatent,
	389	int new, int wait);
	390	extern int fat_alloc_clusters(struct inode inode, int cluster,
	391	int nr_cluster);
	392	extern int fat_free_clusters(struct inode *inode, int cluster);
	393	extern int fat_count_free_clusters(struct super_block *sb);
f663b5b3	394	extern int fat_trim_fs(struct inode inode, struct fstrim_range range);
9e975dae OH	395
9e975dae OH	396	/* fat/file.c */
7845bc3e AB	397	extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
7845bc3e AB	398	unsigned long arg);
9e975dae OH	399	extern const struct file_operations fat_file_operations;
9e975dae OH	400	extern const struct inode_operations fat_file_inode_operations;
c1632a0f	401	extern int fat_setattr(struct mnt_idmap idmap, struct dentry dentry,
549c7297	402	struct iattr *attr);
459f6ed3	403	extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
b74d24f7	404	extern int fat_getattr(struct mnt_idmap *idmap,
549c7297	405	const struct path path, struct kstat stat,
a528d35e	406	u32 request_mask, unsigned int flags);
02c24a82 JB	407	extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
02c24a82 JB	408	int datasync);
9e975dae OH	409
9e975dae OH	410	/* fat/inode.c */
c0ef0cc9	411	extern int fat_block_truncate_page(struct inode *inode, loff_t from);
9e975dae OH	412	extern void fat_attach(struct inode *inode, loff_t i_pos);
	413	extern void fat_detach(struct inode *inode);
	414	extern struct inode fat_iget(struct super_block sb, loff_t i_pos);
	415	extern struct inode fat_build_inode(struct super_block sb,
	416	struct msdos_dir_entry *de, loff_t i_pos);
	417	extern int fat_sync_inode(struct inode *inode);
	418	extern int fat_fill_super(struct super_block sb, void data, int silent,
384f5c96	419	int isvfat, void (setup)(struct super_block ));
f1e6fb0a	420	extern int fat_fill_inode(struct inode inode, struct msdos_dir_entry de);
9e975dae OH	421
9e975dae OH	422	extern int fat_flush_inodes(struct super_block sb, struct inode i1,
d5a4a386	423	struct inode *i2);
7669e8fb	424	static inline unsigned long fat_dir_hash(int logstart)
21b6633d	425	{
7669e8fb	426	return hash_32(logstart, FAT_HASH_BITS);
21b6633d	427	}
b13bb33e	428	extern int fat_add_cluster(struct inode *inode);
21b6633d	429
9e975dae	430	/* fat/misc.c */
b9075fa9 JP	431	extern __printf(3, 4) __cold
b9075fa9 JP	432	void __fat_fs_error(struct super_block sb, int report, const char fmt, ...);
2c8a5ffb OR	433	#define fat_fs_error(sb, fmt, args...) \
	434	__fat_fs_error(sb, 1, fmt , ## args)
	435	#define fat_fs_error_ratelimit(sb, fmt, args...) \
	436	__fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
e057aaec JL	437
	438	#define FAT_PRINTK_PREFIX "%sFAT-fs (%s): "
	439	#define fat_msg(sb, level, fmt, args...) \
	440	do { \
	441	printk_index_subsys_emit(FAT_PRINTK_PREFIX, level, fmt, ##args);\
	442	_fat_msg(sb, level, fmt, ##args); \
	443	} while (0)
b9075fa9	444	__printf(3, 4) __cold
e057aaec	445	void _fat_msg(struct super_block sb, const char level, const char *fmt, ...);
b742c341 NJ	446	#define fat_msg_ratelimit(sb, level, fmt, args...) \
	447	do { \
	448	if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
	449	fat_msg(sb, level, fmt, ## args); \
	450	} while (0)
ed248b29	451	extern int fat_clusters_flush(struct super_block *sb);
9e975dae	452	extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
f423420c	453	extern void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec64 ts,
7decd1cb	454	__le16 __time, __le16 __date, u8 time_cs);
f423420c	455	extern void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec64 ts,
7decd1cb	456	__le16 time, __le16 date, u8 *time_cs);
4dcc3f96 CCC	457	extern struct timespec64 fat_truncate_atime(const struct msdos_sb_info *sbi,
4dcc3f96 CCC	458	const struct timespec64 *ts);
4dcc3f96 CCC	459	extern struct timespec64 fat_truncate_mtime(const struct msdos_sb_info *sbi,
4dcc3f96 CCC	460	const struct timespec64 *ts);
6bb885ec FS	461	extern int fat_truncate_time(struct inode inode, struct timespec64 now,
6bb885ec FS	462	int flags);
913e9928	463	extern int fat_update_time(struct inode *inode, int flags);
9e975dae OH	464	extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
	465
	466	int fat_cache_init(void);
	467	void fat_cache_destroy(void);
	468
21b6633d	469	/* fat/nfs.c */
ea3983ac NJ	470	extern const struct export_operations fat_export_ops;
ea3983ac NJ	471	extern const struct export_operations fat_export_ops_nostale;
21b6633d	472
c3302931 OH	473	/* helper for printk */
	474	typedef unsigned long long llu;
	475
9e975dae	476	#endif /* !_FAT_H */