LXR linux/fs/exfat/exfat

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
   4 */
   5
   6#ifndef _EXFAT_FS_H
   7#define _EXFAT_FS_H
   8
   9#include <linux/fs.h>
  10#include <linux/ratelimit.h>
  11#include <linux/nls.h>
  12
  13#define EXFAT_SUPER_MAGIC       0x2011BAB0UL
  14#define EXFAT_ROOT_INO          1
  15
  16#define EXFAT_CLUSTERS_UNTRACKED (~0u)
  17
  18/*
  19 * exfat error flags
  20 */
  21enum exfat_error_mode {
  22        EXFAT_ERRORS_CONT,      /* ignore error and continue */
  23        EXFAT_ERRORS_PANIC,     /* panic on error */
  24        EXFAT_ERRORS_RO,        /* remount r/o on error */
  25};
  26
  27/*
  28 * exfat nls lossy flag
  29 */
  30enum {
  31        NLS_NAME_NO_LOSSY,      /* no lossy */
  32        NLS_NAME_LOSSY,         /* just detected incorrect filename(s) */
  33        NLS_NAME_OVERLEN,       /* the length is over than its limit */
  34};
  35
  36#define EXFAT_HASH_BITS         8
  37#define EXFAT_HASH_SIZE         (1UL << EXFAT_HASH_BITS)
  38
  39/*
  40 * Type Definitions
  41 */
  42#define ES_2_ENTRIES            2
  43#define ES_ALL_ENTRIES          0
  44
  45#define DIR_DELETED             0xFFFF0321
  46
  47/* type values */
  48#define TYPE_UNUSED             0x0000
  49#define TYPE_DELETED            0x0001
  50#define TYPE_INVALID            0x0002
  51#define TYPE_CRITICAL_PRI       0x0100
  52#define TYPE_BITMAP             0x0101
  53#define TYPE_UPCASE             0x0102
  54#define TYPE_VOLUME             0x0103
  55#define TYPE_DIR                0x0104
  56#define TYPE_FILE               0x011F
  57#define TYPE_CRITICAL_SEC       0x0200
  58#define TYPE_STREAM             0x0201
  59#define TYPE_EXTEND             0x0202
  60#define TYPE_ACL                0x0203
  61#define TYPE_BENIGN_PRI         0x0400
  62#define TYPE_GUID               0x0401
  63#define TYPE_PADDING            0x0402
  64#define TYPE_ACLTAB             0x0403
  65#define TYPE_BENIGN_SEC         0x0800
  66#define TYPE_ALL                0x0FFF
  67
  68#define MAX_CHARSET_SIZE        6 /* max size of multi-byte character */
  69#define MAX_NAME_LENGTH         255 /* max len of file name excluding NULL */
  70#define MAX_VFSNAME_BUF_SIZE    ((MAX_NAME_LENGTH + 1) * MAX_CHARSET_SIZE)
  71
  72/* Enough size to hold 256 dentry (even 512 Byte sector) */
  73#define DIR_CACHE_SIZE          (256*sizeof(struct exfat_dentry)/512+1)
  74
  75#define EXFAT_HINT_NONE         -1
  76#define EXFAT_MIN_SUBDIR        2
  77
  78/*
  79 * helpers for cluster size to byte conversion.
  80 */
  81#define EXFAT_CLU_TO_B(b, sbi)          ((b) << (sbi)->cluster_size_bits)
  82#define EXFAT_B_TO_CLU(b, sbi)          ((b) >> (sbi)->cluster_size_bits)
  83#define EXFAT_B_TO_CLU_ROUND_UP(b, sbi) \
  84        (((b - 1) >> (sbi)->cluster_size_bits) + 1)
  85#define EXFAT_CLU_OFFSET(off, sbi)      ((off) & ((sbi)->cluster_size - 1))
  86
  87/*
  88 * helpers for block size to byte conversion.
  89 */
  90#define EXFAT_BLK_TO_B(b, sb)           ((b) << (sb)->s_blocksize_bits)
  91#define EXFAT_B_TO_BLK(b, sb)           ((b) >> (sb)->s_blocksize_bits)
  92#define EXFAT_B_TO_BLK_ROUND_UP(b, sb)  \
  93        (((b - 1) >> (sb)->s_blocksize_bits) + 1)
  94#define EXFAT_BLK_OFFSET(off, sb)       ((off) & ((sb)->s_blocksize - 1))
  95
  96/*
  97 * helpers for block size to dentry size conversion.
  98 */
  99#define EXFAT_B_TO_DEN_IDX(b, sbi)      \
 100        ((b) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
 101#define EXFAT_B_TO_DEN(b)               ((b) >> DENTRY_SIZE_BITS)
 102#define EXFAT_DEN_TO_B(b)               ((b) << DENTRY_SIZE_BITS)
 103
 104/*
 105 * helpers for fat entry.
 106 */
 107#define FAT_ENT_SIZE (4)
 108#define FAT_ENT_SIZE_BITS (2)
 109#define FAT_ENT_OFFSET_SECTOR(sb, loc) (EXFAT_SB(sb)->FAT1_start_sector + \
 110        (((u64)loc << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits))
 111#define FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc)  \
 112        ((loc << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1))
 113
 114/*
 115 * helpers for bitmap.
 116 */
 117#define CLUSTER_TO_BITMAP_ENT(clu) ((clu) - EXFAT_RESERVED_CLUSTERS)
 118#define BITMAP_ENT_TO_CLUSTER(ent) ((ent) + EXFAT_RESERVED_CLUSTERS)
 119#define BITS_PER_SECTOR(sb) ((sb)->s_blocksize * BITS_PER_BYTE)
 120#define BITS_PER_SECTOR_MASK(sb) (BITS_PER_SECTOR(sb) - 1)
 121#define BITMAP_OFFSET_SECTOR_INDEX(sb, ent) \
 122        ((ent / BITS_PER_BYTE) >> (sb)->s_blocksize_bits)
 123#define BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent) (ent & BITS_PER_SECTOR_MASK(sb))
 124#define BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent) \
 125        ((ent / BITS_PER_BYTE) & ((sb)->s_blocksize - 1))
 126#define BITS_PER_BYTE_MASK      0x7
 127#define IGNORED_BITS_REMAINED(clu, clu_base) ((1 << ((clu) - (clu_base))) - 1)
 128
 129struct exfat_dentry_namebuf {
 130        char *lfn;
 131        int lfnbuf_len; /* usally MAX_UNINAME_BUF_SIZE */
 132};
 133
 134/* unicode name structure */
 135struct exfat_uni_name {
 136        /* +3 for null and for converting */
 137        unsigned short name[MAX_NAME_LENGTH + 3];
 138        u16 name_hash;
 139        unsigned char name_len;
 140};
 141
 142/* directory structure */
 143struct exfat_chain {
 144        unsigned int dir;
 145        unsigned int size;
 146        unsigned char flags;
 147};
 148
 149/* first empty entry hint information */
 150struct exfat_hint_femp {
 151        /* entry index of a directory */
 152        int eidx;
 153        /* count of continuous empty entry */
 154        int count;
 155        /* the cluster that first empty slot exists in */
 156        struct exfat_chain cur;
 157};
 158
 159/* hint structure */
 160struct exfat_hint {
 161        unsigned int clu;
 162        union {
 163                unsigned int off; /* cluster offset */
 164                int eidx; /* entry index */
 165        };
 166};
 167
 168struct exfat_entry_set_cache {
 169        struct super_block *sb;
 170        bool modified;
 171        unsigned int start_off;
 172        int num_bh;
 173        struct buffer_head *bh[DIR_CACHE_SIZE];
 174        unsigned int num_entries;
 175};
 176
 177struct exfat_dir_entry {
 178        struct exfat_chain dir;
 179        int entry;
 180        unsigned int type;
 181        unsigned int start_clu;
 182        unsigned char flags;
 183        unsigned short attr;
 184        loff_t size;
 185        unsigned int num_subdirs;
 186        struct timespec64 atime;
 187        struct timespec64 mtime;
 188        struct timespec64 crtime;
 189        struct exfat_dentry_namebuf namebuf;
 190};
 191
 192/*
 193 * exfat mount in-memory data
 194 */
 195struct exfat_mount_options {
 196        kuid_t fs_uid;
 197        kgid_t fs_gid;
 198        unsigned short fs_fmask;
 199        unsigned short fs_dmask;
 200        /* permission for setting the [am]time */
 201        unsigned short allow_utime;
 202        /* charset for filename input/display */
 203        char *iocharset;
 204        /* on error: continue, panic, remount-ro */
 205        enum exfat_error_mode errors;
 206        unsigned utf8:1, /* Use of UTF-8 character set */
 207                 discard:1; /* Issue discard requests on deletions */
 208        int time_offset; /* Offset of timestamps from UTC (in minutes) */
 209};
 210
 211/*
 212 * EXFAT file system superblock in-memory data
 213 */
 214struct exfat_sb_info {
 215        unsigned long long num_sectors; /* num of sectors in volume */
 216        unsigned int num_clusters; /* num of clusters in volume */
 217        unsigned int cluster_size; /* cluster size in bytes */
 218        unsigned int cluster_size_bits;
 219        unsigned int sect_per_clus; /* cluster size in sectors */
 220        unsigned int sect_per_clus_bits;
 221        unsigned long long FAT1_start_sector; /* FAT1 start sector */
 222        unsigned long long FAT2_start_sector; /* FAT2 start sector */
 223        unsigned long long data_start_sector; /* data area start sector */
 224        unsigned int num_FAT_sectors; /* num of FAT sectors */
 225        unsigned int root_dir; /* root dir cluster */
 226        unsigned int dentries_per_clu; /* num of dentries per cluster */
 227        unsigned int vol_flags; /* volume flags */
 228        unsigned int vol_flags_persistent; /* volume flags to retain */
 229        struct buffer_head *boot_bh; /* buffer_head of BOOT sector */
 230
 231        unsigned int map_clu; /* allocation bitmap start cluster */
 232        unsigned int map_sectors; /* num of allocation bitmap sectors */
 233        struct buffer_head **vol_amap; /* allocation bitmap */
 234
 235        unsigned short *vol_utbl; /* upcase table */
 236
 237        unsigned int clu_srch_ptr; /* cluster search pointer */
 238        unsigned int used_clusters; /* number of used clusters */
 239
 240        struct mutex s_lock; /* superblock lock */
 241        struct exfat_mount_options options;
 242        struct nls_table *nls_io; /* Charset used for input and display */
 243        struct ratelimit_state ratelimit;
 244
 245        spinlock_t inode_hash_lock;
 246        struct hlist_head inode_hashtable[EXFAT_HASH_SIZE];
 247
 248        struct rcu_head rcu;
 249};
 250
 251#define EXFAT_CACHE_VALID       0
 252
 253/*
 254 * EXFAT file system inode in-memory data
 255 */
 256struct exfat_inode_info {
 257        struct exfat_chain dir;
 258        int entry;
 259        unsigned int type;
 260        unsigned short attr;
 261        unsigned int start_clu;
 262        unsigned char flags;
 263        /*
 264         * the copy of low 32bit of i_version to check
 265         * the validation of hint_stat.
 266         */
 267        unsigned int version;
 268        /* file offset or dentry index for readdir */
 269        loff_t rwoffset;
 270
 271        /* hint for cluster last accessed */
 272        struct exfat_hint hint_bmap;
 273        /* hint for entry index we try to lookup next time */
 274        struct exfat_hint hint_stat;
 275        /* hint for first empty entry */
 276        struct exfat_hint_femp hint_femp;
 277
 278        spinlock_t cache_lru_lock;
 279        struct list_head cache_lru;
 280        int nr_caches;
 281        /* for avoiding the race between alloc and free */
 282        unsigned int cache_valid_id;
 283
 284        /*
 285         * NOTE: i_size_ondisk is 64bits, so must hold ->inode_lock to access.
 286         * physically allocated size.
 287         */
 288        loff_t i_size_ondisk;
 289        /* block-aligned i_size (used in cont_write_begin) */
 290        loff_t i_size_aligned;
 291        /* on-disk position of directory entry or 0 */
 292        loff_t i_pos;
 293        /* hash by i_location */
 294        struct hlist_node i_hash_fat;
 295        /* protect bmap against truncate */
 296        struct rw_semaphore truncate_lock;
 297        struct inode vfs_inode;
 298        /* File creation time */
 299        struct timespec64 i_crtime;
 300};
 301
 302static inline struct exfat_sb_info *EXFAT_SB(struct super_block *sb)
 303{
 304        return sb->s_fs_info;
 305}
 306
 307static inline struct exfat_inode_info *EXFAT_I(struct inode *inode)
 308{
 309        return container_of(inode, struct exfat_inode_info, vfs_inode);
 310}
 311
 312/*
 313 * If ->i_mode can't hold 0222 (i.e. ATTR_RO), we use ->i_attrs to
 314 * save ATTR_RO instead of ->i_mode.
 315 *
 316 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
 317 * bit, it's just used as flag for app.
 318 */
 319static inline int exfat_mode_can_hold_ro(struct inode *inode)
 320{
 321        struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
 322
 323        if (S_ISDIR(inode->i_mode))
 324                return 0;
 325
 326        if ((~sbi->options.fs_fmask) & 0222)
 327                return 1;
 328        return 0;
 329}
 330
 331/* Convert attribute bits and a mask to the UNIX mode. */
 332static inline mode_t exfat_make_mode(struct exfat_sb_info *sbi,
 333                unsigned short attr, mode_t mode)
 334{
 335        if ((attr & ATTR_READONLY) && !(attr & ATTR_SUBDIR))
 336                mode &= ~0222;
 337
 338        if (attr & ATTR_SUBDIR)
 339                return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
 340
 341        return (mode & ~sbi->options.fs_fmask) | S_IFREG;
 342}
 343
 344/* Return the FAT attribute byte for this inode */
 345static inline unsigned short exfat_make_attr(struct inode *inode)
 346{
 347        unsigned short attr = EXFAT_I(inode)->attr;
 348
 349        if (S_ISDIR(inode->i_mode))
 350                attr |= ATTR_SUBDIR;
 351        if (exfat_mode_can_hold_ro(inode) && !(inode->i_mode & 0222))
 352                attr |= ATTR_READONLY;
 353        return attr;
 354}
 355
 356static inline void exfat_save_attr(struct inode *inode, unsigned short attr)
 357{
 358        if (exfat_mode_can_hold_ro(inode))
 359                EXFAT_I(inode)->attr = attr & (ATTR_RWMASK | ATTR_READONLY);
 360        else
 361                EXFAT_I(inode)->attr = attr & ATTR_RWMASK;
 362}
 363
 364static inline bool exfat_is_last_sector_in_cluster(struct exfat_sb_info *sbi,
 365                sector_t sec)
 366{
 367        return ((sec - sbi->data_start_sector + 1) &
 368                ((1 << sbi->sect_per_clus_bits) - 1)) == 0;
 369}
 370
 371static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
 372                unsigned int clus)
 373{
 374        return ((sector_t)(clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
 375                sbi->data_start_sector;
 376}
 377
 378static inline int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
 379                sector_t sec)
 380{
 381        return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
 382                EXFAT_RESERVED_CLUSTERS;
 383}
 384
 385/* super.c */
 386int exfat_set_volume_dirty(struct super_block *sb);
 387int exfat_clear_volume_dirty(struct super_block *sb);
 388
 389/* fatent.c */
 390#define exfat_get_next_cluster(sb, pclu) exfat_ent_get(sb, *(pclu), pclu)
 391
 392int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
 393                struct exfat_chain *p_chain);
 394int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain);
 395int exfat_ent_get(struct super_block *sb, unsigned int loc,
 396                unsigned int *content);
 397int exfat_ent_set(struct super_block *sb, unsigned int loc,
 398                unsigned int content);
 399int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
 400                int entry, struct exfat_dentry *p_entry);
 401int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
 402                unsigned int len);
 403int exfat_zeroed_cluster(struct inode *dir, unsigned int clu);
 404int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
 405                unsigned int *ret_clu);
 406int exfat_count_num_clusters(struct super_block *sb,
 407                struct exfat_chain *p_chain, unsigned int *ret_count);
 408
 409/* balloc.c */
 410int exfat_load_bitmap(struct super_block *sb);
 411void exfat_free_bitmap(struct exfat_sb_info *sbi);
 412int exfat_set_bitmap(struct inode *inode, unsigned int clu);
 413void exfat_clear_bitmap(struct inode *inode, unsigned int clu);
 414unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
 415int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
 416
 417/* file.c */
 418extern const struct file_operations exfat_file_operations;
 419int __exfat_truncate(struct inode *inode, loff_t new_size);
 420void exfat_truncate(struct inode *inode, loff_t size);
 421int exfat_setattr(struct dentry *dentry, struct iattr *attr);
 422int exfat_getattr(const struct path *path, struct kstat *stat,
 423                unsigned int request_mask, unsigned int query_flags);
 424int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
 425
 426/* namei.c */
 427extern const struct dentry_operations exfat_dentry_ops;
 428extern const struct dentry_operations exfat_utf8_dentry_ops;
 429
 430/* cache.c */
 431int exfat_cache_init(void);
 432void exfat_cache_shutdown(void);
 433void exfat_cache_inval_inode(struct inode *inode);
 434int exfat_get_cluster(struct inode *inode, unsigned int cluster,
 435                unsigned int *fclus, unsigned int *dclus,
 436                unsigned int *last_dclus, int allow_eof);
 437
 438/* dir.c */
 439extern const struct inode_operations exfat_dir_inode_operations;
 440extern const struct file_operations exfat_dir_operations;
 441unsigned int exfat_get_entry_type(struct exfat_dentry *p_entry);
 442int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
 443                int entry, unsigned int type, unsigned int start_clu,
 444                unsigned long long size);
 445int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
 446                int entry, int num_entries, struct exfat_uni_name *p_uniname);
 447int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
 448                int entry, int order, int num_entries);
 449int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
 450                int entry);
 451void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es);
 452int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
 453int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
 454                struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
 455                int num_entries, unsigned int type);
 456int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
 457int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
 458                int entry, sector_t *sector, int *offset);
 459struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
 460                struct exfat_chain *p_dir, int entry, struct buffer_head **bh,
 461                sector_t *sector);
 462struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
 463                int num);
 464struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
 465                struct exfat_chain *p_dir, int entry, unsigned int type);
 466int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
 467int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
 468
 469/* inode.c */
 470extern const struct inode_operations exfat_file_inode_operations;
 471void exfat_sync_inode(struct inode *inode);
 472struct inode *exfat_build_inode(struct super_block *sb,
 473                struct exfat_dir_entry *info, loff_t i_pos);
 474void exfat_hash_inode(struct inode *inode, loff_t i_pos);
 475void exfat_unhash_inode(struct inode *inode);
 476struct inode *exfat_iget(struct super_block *sb, loff_t i_pos);
 477int exfat_write_inode(struct inode *inode, struct writeback_control *wbc);
 478void exfat_evict_inode(struct inode *inode);
 479int exfat_block_truncate_page(struct inode *inode, loff_t from);
 480
 481/* exfat/nls.c */
 482unsigned short exfat_toupper(struct super_block *sb, unsigned short a);
 483int exfat_uniname_ncmp(struct super_block *sb, unsigned short *a,
 484                unsigned short *b, unsigned int len);
 485int exfat_utf16_to_nls(struct super_block *sb,
 486                struct exfat_uni_name *uniname, unsigned char *p_cstring,
 487                int len);
 488int exfat_nls_to_utf16(struct super_block *sb,
 489                const unsigned char *p_cstring, const int len,
 490                struct exfat_uni_name *uniname, int *p_lossy);
 491int exfat_create_upcase_table(struct super_block *sb);
 492void exfat_free_upcase_table(struct exfat_sb_info *sbi);
 493
 494/* exfat/misc.c */
 495void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
 496                __printf(3, 4) __cold;
 497#define exfat_fs_error(sb, fmt, args...)          \
 498                __exfat_fs_error(sb, 1, fmt, ## args)
 499#define exfat_fs_error_ratelimit(sb, fmt, args...) \
 500                __exfat_fs_error(sb, __ratelimit(&EXFAT_SB(sb)->ratelimit), \
 501                fmt, ## args)
 502void exfat_msg(struct super_block *sb, const char *lv, const char *fmt, ...)
 503                __printf(3, 4) __cold;
 504#define exfat_err(sb, fmt, ...)                                         \
 505        exfat_msg(sb, KERN_ERR, fmt, ##__VA_ARGS__)
 506#define exfat_warn(sb, fmt, ...)                                        \
 507        exfat_msg(sb, KERN_WARNING, fmt, ##__VA_ARGS__)
 508#define exfat_info(sb, fmt, ...)                                        \
 509        exfat_msg(sb, KERN_INFO, fmt, ##__VA_ARGS__)
 510
 511void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
 512                u8 tz, __le16 time, __le16 date, u8 time_cs);
 513void exfat_truncate_atime(struct timespec64 *ts);
 514void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
 515                u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
 516u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
 517u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
 518void exfat_update_bh(struct buffer_head *bh, int sync);
 519int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync);
 520void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
 521                unsigned int size, unsigned char flags);
 522void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);
 523
 524#endif /* !_EXFAT_FS_H */
 525