fs/hfsplus/hfsplus_fs.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  linux/include/linux/hfsplus_fs.h
   4  *
   5  * Copyright (C) 1999
   6  * Brad Boyer (flar@pants.nu)
   7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8  *
   9  */
  10
  11 #ifndef _LINUX_HFSPLUS_FS_H
  12 #define _LINUX_HFSPLUS_FS_H
  13
  14 #ifdef pr_fmt
  15 #undef pr_fmt
  16 #endif
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/fs.h>
  21 #include <linux/mutex.h>
  22 #include <linux/buffer_head.h>
  23 #include <linux/blkdev.h>
  24 #include <linux/fs_context.h>
  25 #include "hfsplus_raw.h"
  26
  27 #define DBG_BNODE_REFS  0x00000001
  28 #define DBG_BNODE_MOD   0x00000002
  29 #define DBG_CAT_MOD     0x00000004
  30 #define DBG_INODE       0x00000008
  31 #define DBG_SUPER       0x00000010
  32 #define DBG_EXTENT      0x00000020
  33 #define DBG_BITMAP      0x00000040
  34 #define DBG_ATTR_MOD    0x00000080
  35
  36 #if 0
  37 #define DBG_MASK        (DBG_EXTENT|DBG_INODE|DBG_BNODE_MOD)
  38 #define DBG_MASK        (DBG_BNODE_MOD|DBG_CAT_MOD|DBG_INODE)
  39 #define DBG_MASK        (DBG_CAT_MOD|DBG_BNODE_REFS|DBG_INODE|DBG_EXTENT)
  40 #endif
  41 #define DBG_MASK        (0)
  42
  43 #define hfs_dbg(flg, fmt, ...)                                  \
  44 do {                                                            \
  45         if (DBG_##flg & DBG_MASK)                               \
  46                 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);  \
  47 } while (0)
  48
  49 #define hfs_dbg_cont(flg, fmt, ...)                             \
  50 do {                                                            \
  51         if (DBG_##flg & DBG_MASK)                               \
  52                 pr_cont(fmt, ##__VA_ARGS__);                    \
  53 } while (0)
  54
  55 /* Runtime config options */
  56 #define HFSPLUS_DEF_CR_TYPE    0x3F3F3F3F  /* '????' */
  57
  58 #define HFSPLUS_TYPE_DATA 0x00
  59 #define HFSPLUS_TYPE_RSRC 0xFF
  60
  61 typedef int (*btree_keycmp)(const hfsplus_btree_key *,
  62                 const hfsplus_btree_key *);
  63
  64 #define NODE_HASH_SIZE  256
  65
  66 /* B-tree mutex nested subclasses */
  67 enum hfsplus_btree_mutex_classes {
  68         CATALOG_BTREE_MUTEX,
  69         EXTENTS_BTREE_MUTEX,
  70         ATTR_BTREE_MUTEX,
  71 };
  72
  73 /* An HFS+ BTree held in memory */
  74 struct hfs_btree {
  75         struct super_block *sb;
  76         struct inode *inode;
  77         btree_keycmp keycmp;
  78
  79         u32 cnid;
  80         u32 root;
  81         u32 leaf_count;
  82         u32 leaf_head;
  83         u32 leaf_tail;
  84         u32 node_count;
  85         u32 free_nodes;
  86         u32 attributes;
  87
  88         unsigned int node_size;
  89         unsigned int node_size_shift;
  90         unsigned int max_key_len;
  91         unsigned int depth;
  92
  93         struct mutex tree_lock;
  94
  95         unsigned int pages_per_bnode;
  96         spinlock_t hash_lock;
  97         struct hfs_bnode *node_hash[NODE_HASH_SIZE];
  98         int node_hash_cnt;
  99 };
 100
 101 struct page;
 102
 103 /* An HFS+ BTree node in memory */
 104 struct hfs_bnode {
 105         struct hfs_btree *tree;
 106
 107         u32 prev;
 108         u32 this;
 109         u32 next;
 110         u32 parent;
 111
 112         u16 num_recs;
 113         u8 type;
 114         u8 height;
 115
 116         struct hfs_bnode *next_hash;
 117         unsigned long flags;
 118         wait_queue_head_t lock_wq;
 119         atomic_t refcnt;
 120         unsigned int page_offset;
 121         struct page *page[];
 122 };
 123
 124 #define HFS_BNODE_LOCK          0
 125 #define HFS_BNODE_ERROR         1
 126 #define HFS_BNODE_NEW           2
 127 #define HFS_BNODE_DIRTY         3
 128 #define HFS_BNODE_DELETED       4
 129
 130 /*
 131  * Attributes file states
 132  */
 133 #define HFSPLUS_EMPTY_ATTR_TREE         0
 134 #define HFSPLUS_CREATING_ATTR_TREE      1
 135 #define HFSPLUS_VALID_ATTR_TREE         2
 136 #define HFSPLUS_FAILED_ATTR_TREE        3
 137
 138 /*
 139  * HFS+ superblock info (built from Volume Header on disk)
 140  */
 141
 142 struct hfsplus_vh;
 143 struct hfs_btree;
 144
 145 struct hfsplus_sb_info {
 146         void *s_vhdr_buf;
 147         struct hfsplus_vh *s_vhdr;
 148         void *s_backup_vhdr_buf;
 149         struct hfsplus_vh *s_backup_vhdr;
 150         struct hfs_btree *ext_tree;
 151         struct hfs_btree *cat_tree;
 152         struct hfs_btree *attr_tree;
 153         atomic_t attr_tree_state;
 154         struct inode *alloc_file;
 155         struct inode *hidden_dir;
 156         struct nls_table *nls;
 157
 158         /* Runtime variables */
 159         u32 blockoffset;
 160         u32 min_io_size;
 161         sector_t part_start;
 162         sector_t sect_count;
 163         int fs_shift;
 164
 165         /* immutable data from the volume header */
 166         u32 alloc_blksz;
 167         int alloc_blksz_shift;
 168         u32 total_blocks;
 169         u32 data_clump_blocks, rsrc_clump_blocks;
 170
 171         /* mutable data from the volume header, protected by alloc_mutex */
 172         u32 free_blocks;
 173         struct mutex alloc_mutex;
 174
 175         /* mutable data from the volume header, protected by vh_mutex */
 176         u32 next_cnid;
 177         u32 file_count;
 178         u32 folder_count;
 179         struct mutex vh_mutex;
 180
 181         /* Config options */
 182         u32 creator;
 183         u32 type;
 184
 185         umode_t umask;
 186         kuid_t uid;
 187         kgid_t gid;
 188
 189         int part, session;
 190         unsigned long flags;
 191
 192         int work_queued;               /* non-zero delayed work is queued */
 193         struct delayed_work sync_work; /* FS sync delayed work */
 194         spinlock_t work_lock;          /* protects sync_work and work_queued */
 195         struct rcu_head rcu;
 196 };
 197
 198 #define HFSPLUS_SB_WRITEBACKUP  0
 199 #define HFSPLUS_SB_NODECOMPOSE  1
 200 #define HFSPLUS_SB_FORCE        2
 201 #define HFSPLUS_SB_HFSX         3
 202 #define HFSPLUS_SB_CASEFOLD     4
 203 #define HFSPLUS_SB_NOBARRIER    5
 204 #define HFSPLUS_SB_UID          6
 205 #define HFSPLUS_SB_GID          7
 206
 207 static inline struct hfsplus_sb_info *HFSPLUS_SB(struct super_block *sb)
 208 {
 209         return sb->s_fs_info;
 210 }
 211
 212
 213 struct hfsplus_inode_info {
 214         atomic_t opencnt;
 215
 216         /*
 217          * Extent allocation information, protected by extents_lock.
 218          */
 219         u32 first_blocks;
 220         u32 clump_blocks;
 221         u32 alloc_blocks;
 222         u32 cached_start;
 223         u32 cached_blocks;
 224         hfsplus_extent_rec first_extents;
 225         hfsplus_extent_rec cached_extents;
 226         unsigned int extent_state;
 227         struct mutex extents_lock;
 228
 229         /*
 230          * Immutable data.
 231          */
 232         struct inode *rsrc_inode;
 233         __be32 create_date;
 234
 235         /*
 236          * Protected by sbi->vh_mutex.
 237          */
 238         u32 linkid;
 239
 240         /*
 241          * Accessed using atomic bitops.
 242          */
 243         unsigned long flags;
 244
 245         /*
 246          * Protected by i_mutex.
 247          */
 248         sector_t fs_blocks;
 249         u8 userflags;           /* BSD user file flags */
 250         u32 subfolders;         /* Subfolder count (HFSX only) */
 251         struct list_head open_dir_list;
 252         spinlock_t open_dir_lock;
 253         loff_t phys_size;
 254
 255         struct inode vfs_inode;
 256 };
 257
 258 #define HFSPLUS_EXT_DIRTY       0x0001
 259 #define HFSPLUS_EXT_NEW         0x0002
 260
 261 #define HFSPLUS_I_RSRC          0       /* represents a resource fork */
 262 #define HFSPLUS_I_CAT_DIRTY     1       /* has changes in the catalog tree */
 263 #define HFSPLUS_I_EXT_DIRTY     2       /* has changes in the extent tree */
 264 #define HFSPLUS_I_ALLOC_DIRTY   3       /* has changes in the allocation file */
 265 #define HFSPLUS_I_ATTR_DIRTY    4       /* has changes in the attributes tree */
 266
 267 #define HFSPLUS_IS_RSRC(inode) \
 268         test_bit(HFSPLUS_I_RSRC, &HFSPLUS_I(inode)->flags)
 269
 270 static inline struct hfsplus_inode_info *HFSPLUS_I(struct inode *inode)
 271 {
 272         return container_of(inode, struct hfsplus_inode_info, vfs_inode);
 273 }
 274
 275 /*
 276  * Mark an inode dirty, and also mark the btree in which the
 277  * specific type of metadata is stored.
 278  * For data or metadata that gets written back by into the catalog btree
 279  * by hfsplus_write_inode a plain mark_inode_dirty call is enough.
 280  */
 281 static inline void hfsplus_mark_inode_dirty(struct inode *inode,
 282                 unsigned int flag)
 283 {
 284         set_bit(flag, &HFSPLUS_I(inode)->flags);
 285         mark_inode_dirty(inode);
 286 }
 287
 288 struct hfs_find_data {
 289         /* filled by caller */
 290         hfsplus_btree_key *search_key;
 291         hfsplus_btree_key *key;
 292         /* filled by find */
 293         struct hfs_btree *tree;
 294         struct hfs_bnode *bnode;
 295         /* filled by findrec */
 296         int record;
 297         int keyoffset, keylength;
 298         int entryoffset, entrylength;
 299 };
 300
 301 struct hfsplus_readdir_data {
 302         struct list_head list;
 303         struct file *file;
 304         struct hfsplus_cat_key key;
 305 };
 306
 307 /*
 308  * Find minimum acceptible I/O size for an hfsplus sb.
 309  */
 310 static inline unsigned short hfsplus_min_io_size(struct super_block *sb)
 311 {
 312         return max_t(unsigned short, HFSPLUS_SB(sb)->min_io_size,
 313                      HFSPLUS_SECTOR_SIZE);
 314 }
 315
 316 #define hfs_btree_open hfsplus_btree_open
 317 #define hfs_btree_close hfsplus_btree_close
 318 #define hfs_btree_write hfsplus_btree_write
 319 #define hfs_bmap_reserve hfsplus_bmap_reserve
 320 #define hfs_bmap_alloc hfsplus_bmap_alloc
 321 #define hfs_bmap_free hfsplus_bmap_free
 322 #define hfs_bnode_read hfsplus_bnode_read
 323 #define hfs_bnode_read_u16 hfsplus_bnode_read_u16
 324 #define hfs_bnode_read_u8 hfsplus_bnode_read_u8
 325 #define hfs_bnode_read_key hfsplus_bnode_read_key
 326 #define hfs_bnode_write hfsplus_bnode_write
 327 #define hfs_bnode_write_u16 hfsplus_bnode_write_u16
 328 #define hfs_bnode_clear hfsplus_bnode_clear
 329 #define hfs_bnode_copy hfsplus_bnode_copy
 330 #define hfs_bnode_move hfsplus_bnode_move
 331 #define hfs_bnode_dump hfsplus_bnode_dump
 332 #define hfs_bnode_unlink hfsplus_bnode_unlink
 333 #define hfs_bnode_findhash hfsplus_bnode_findhash
 334 #define hfs_bnode_find hfsplus_bnode_find
 335 #define hfs_bnode_unhash hfsplus_bnode_unhash
 336 #define hfs_bnode_free hfsplus_bnode_free
 337 #define hfs_bnode_create hfsplus_bnode_create
 338 #define hfs_bnode_get hfsplus_bnode_get
 339 #define hfs_bnode_put hfsplus_bnode_put
 340 #define hfs_brec_lenoff hfsplus_brec_lenoff
 341 #define hfs_brec_keylen hfsplus_brec_keylen
 342 #define hfs_brec_insert hfsplus_brec_insert
 343 #define hfs_brec_remove hfsplus_brec_remove
 344 #define hfs_find_init hfsplus_find_init
 345 #define hfs_find_exit hfsplus_find_exit
 346 #define __hfs_brec_find __hfsplus_brec_find
 347 #define hfs_brec_find hfsplus_brec_find
 348 #define hfs_brec_read hfsplus_brec_read
 349 #define hfs_brec_goto hfsplus_brec_goto
 350 #define hfs_part_find hfsplus_part_find
 351
 352 /*
 353  * hfs+-specific ioctl for making the filesystem bootable
 354  */
 355 #define HFSPLUS_IOC_BLESS _IO('h', 0x80)
 356
 357 typedef int (*search_strategy_t)(struct hfs_bnode *,
 358                                 struct hfs_find_data *,
 359                                 int *, int *, int *);
 360
 361 /*
 362  * Functions in any *.c used in other files
 363  */
 364
 365 /* attributes.c */
 366 int __init hfsplus_create_attr_tree_cache(void);
 367 void hfsplus_destroy_attr_tree_cache(void);
 368 int hfsplus_attr_bin_cmp_key(const hfsplus_btree_key *k1,
 369                              const hfsplus_btree_key *k2);
 370 int hfsplus_attr_build_key(struct super_block *sb, hfsplus_btree_key *key,
 371                            u32 cnid, const char *name);
 372 hfsplus_attr_entry *hfsplus_alloc_attr_entry(void);
 373 void hfsplus_destroy_attr_entry(hfsplus_attr_entry *entry);
 374 int hfsplus_find_attr(struct super_block *sb, u32 cnid, const char *name,
 375                       struct hfs_find_data *fd);
 376 int hfsplus_attr_exists(struct inode *inode, const char *name);
 377 int hfsplus_create_attr(struct inode *inode, const char *name,
 378                         const void *value, size_t size);
 379 int hfsplus_delete_attr(struct inode *inode, const char *name);
 380 int hfsplus_delete_all_attrs(struct inode *dir, u32 cnid);
 381
 382 /* bitmap.c */
 383 int hfsplus_block_allocate(struct super_block *sb, u32 size, u32 offset,
 384                            u32 *max);
 385 int hfsplus_block_free(struct super_block *sb, u32 offset, u32 count);
 386
 387 /* btree.c */
 388 u32 hfsplus_calc_btree_clump_size(u32 block_size, u32 node_size, u64 sectors,
 389                                   int file_id);
 390 struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id);
 391 void hfs_btree_close(struct hfs_btree *tree);
 392 int hfs_btree_write(struct hfs_btree *tree);
 393 int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes);
 394 struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree);
 395 void hfs_bmap_free(struct hfs_bnode *node);
 396
 397 /* bnode.c */
 398 void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len);
 399 u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off);
 400 u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off);
 401 void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off);
 402 void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len);
 403 void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data);
 404 void hfs_bnode_clear(struct hfs_bnode *node, int off, int len);
 405 void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
 406                     struct hfs_bnode *src_node, int src, int len);
 407 void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len);
 408 void hfs_bnode_dump(struct hfs_bnode *node);
 409 void hfs_bnode_unlink(struct hfs_bnode *node);
 410 struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid);
 411 void hfs_bnode_unhash(struct hfs_bnode *node);
 412 struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num);
 413 void hfs_bnode_free(struct hfs_bnode *node);
 414 struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num);
 415 void hfs_bnode_get(struct hfs_bnode *node);
 416 void hfs_bnode_put(struct hfs_bnode *node);
 417 bool hfs_bnode_need_zeroout(struct hfs_btree *tree);
 418
 419 /* brec.c */
 420 u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off);
 421 u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec);
 422 int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len);
 423 int hfs_brec_remove(struct hfs_find_data *fd);
 424
 425 /* bfind.c */
 426 int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd);
 427 void hfs_find_exit(struct hfs_find_data *fd);
 428 int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode, struct hfs_find_data *fd,
 429                              int *begin, int *end, int *cur_rec);
 430 int hfs_find_rec_by_key(struct hfs_bnode *bnode, struct hfs_find_data *fd,
 431                         int *begin, int *end, int *cur_rec);
 432 int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd,
 433                     search_strategy_t rec_found);
 434 int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare);
 435 int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len);
 436 int hfs_brec_goto(struct hfs_find_data *fd, int cnt);
 437
 438 /* catalog.c */
 439 int hfsplus_cat_case_cmp_key(const hfsplus_btree_key *k1,
 440                              const hfsplus_btree_key *k2);
 441 int hfsplus_cat_bin_cmp_key(const hfsplus_btree_key *k1,
 442                             const hfsplus_btree_key *k2);
 443 int hfsplus_cat_build_key(struct super_block *sb, hfsplus_btree_key *key,
 444                            u32 parent, const struct qstr *str);
 445 void hfsplus_cat_build_key_with_cnid(struct super_block *sb,
 446                                      hfsplus_btree_key *key, u32 parent);
 447 void hfsplus_cat_set_perms(struct inode *inode, struct hfsplus_perm *perms);
 448 int hfsplus_find_cat(struct super_block *sb, u32 cnid,
 449                      struct hfs_find_data *fd);
 450 int hfsplus_create_cat(u32 cnid, struct inode *dir, const struct qstr *str,
 451                        struct inode *inode);
 452 int hfsplus_delete_cat(u32 cnid, struct inode *dir, const struct qstr *str);
 453 int hfsplus_rename_cat(u32 cnid, struct inode *src_dir, const struct qstr *src_name,
 454                        struct inode *dst_dir, const struct qstr *dst_name);
 455
 456 /* dir.c */
 457 extern const struct inode_operations hfsplus_dir_inode_operations;
 458 extern const struct file_operations hfsplus_dir_operations;
 459
 460 /* extents.c */
 461 int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
 462                         const hfsplus_btree_key *k2);
 463 int hfsplus_ext_write_extent(struct inode *inode);
 464 int hfsplus_get_block(struct inode *inode, sector_t iblock,
 465                       struct buffer_head *bh_result, int create);
 466 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
 467                       struct hfsplus_fork_raw *fork, int type);
 468 int hfsplus_file_extend(struct inode *inode, bool zeroout);
 469 void hfsplus_file_truncate(struct inode *inode);
 470
 471 /* inode.c */
 472 extern const struct address_space_operations hfsplus_aops;
 473 extern const struct address_space_operations hfsplus_btree_aops;
 474 extern const struct dentry_operations hfsplus_dentry_operations;
 475
 476 int hfsplus_write_begin(struct file *file, struct address_space *mapping,
 477                 loff_t pos, unsigned len, struct folio **foliop, void **fsdata);
 478 struct inode *hfsplus_new_inode(struct super_block *sb, struct inode *dir,
 479                                 umode_t mode);
 480 void hfsplus_delete_inode(struct inode *inode);
 481 void hfsplus_inode_read_fork(struct inode *inode,
 482                              struct hfsplus_fork_raw *fork);
 483 void hfsplus_inode_write_fork(struct inode *inode,
 484                               struct hfsplus_fork_raw *fork);
 485 int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd);
 486 int hfsplus_cat_write_inode(struct inode *inode);
 487 int hfsplus_getattr(struct mnt_idmap *idmap, const struct path *path,
 488                     struct kstat *stat, u32 request_mask,
 489                     unsigned int query_flags);
 490 int hfsplus_file_fsync(struct file *file, loff_t start, loff_t end,
 491                        int datasync);
 492 int hfsplus_fileattr_get(struct dentry *dentry, struct fileattr *fa);
 493 int hfsplus_fileattr_set(struct mnt_idmap *idmap,
 494                          struct dentry *dentry, struct fileattr *fa);
 495
 496 /* ioctl.c */
 497 long hfsplus_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 498
 499 /* options.c */
 500 void hfsplus_fill_defaults(struct hfsplus_sb_info *opts);
 501 int hfsplus_parse_param(struct fs_context *fc, struct fs_parameter *param);
 502 int hfsplus_show_options(struct seq_file *seq, struct dentry *root);
 503
 504 /* part_tbl.c */
 505 int hfs_part_find(struct super_block *sb, sector_t *part_start,
 506                   sector_t *part_size);
 507
 508 /* super.c */
 509 struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino);
 510 void hfsplus_mark_mdb_dirty(struct super_block *sb);
 511
 512 /* tables.c */
 513 extern u16 hfsplus_case_fold_table[];
 514 extern u16 hfsplus_decompose_table[];
 515 extern u16 hfsplus_compose_table[];
 516
 517 /* unicode.c */
 518 int hfsplus_strcasecmp(const struct hfsplus_unistr *s1,
 519                        const struct hfsplus_unistr *s2);
 520 int hfsplus_strcmp(const struct hfsplus_unistr *s1,
 521                    const struct hfsplus_unistr *s2);
 522 int hfsplus_uni2asc(struct super_block *sb, const struct hfsplus_unistr *ustr,
 523                     char *astr, int *len_p);
 524 int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
 525                     int max_unistr_len, const char *astr, int len);
 526 int hfsplus_hash_dentry(const struct dentry *dentry, struct qstr *str);
 527 int hfsplus_compare_dentry(const struct dentry *dentry, unsigned int len,
 528                            const char *str, const struct qstr *name);
 529
 530 /* wrapper.c */
 531 int hfsplus_submit_bio(struct super_block *sb, sector_t sector, void *buf,
 532                        void **data, blk_opf_t opf);
 533 int hfsplus_read_wrapper(struct super_block *sb);
 534
 535 /*
 536  * time helpers: convert between 1904-base and 1970-base timestamps
 537  *
 538  * HFS+ implementations are highly inconsistent, this one matches the
 539  * traditional behavior of 64-bit Linux, giving the most useful
 540  * time range between 1970 and 2106, by treating any on-disk timestamp
 541  * under HFSPLUS_UTC_OFFSET (Jan 1 1970) as a time between 2040 and 2106.
 542  */
 543 #define HFSPLUS_UTC_OFFSET 2082844800U
 544
 545 static inline time64_t __hfsp_mt2ut(__be32 mt)
 546 {
 547         time64_t ut = (u32)(be32_to_cpu(mt) - HFSPLUS_UTC_OFFSET);
 548
 549         return ut;
 550 }
 551
 552 static inline __be32 __hfsp_ut2mt(time64_t ut)
 553 {
 554         return cpu_to_be32(lower_32_bits(ut) + HFSPLUS_UTC_OFFSET);
 555 }
 556
 557 static inline enum hfsplus_btree_mutex_classes
 558 hfsplus_btree_lock_class(struct hfs_btree *tree)
 559 {
 560         enum hfsplus_btree_mutex_classes class;
 561
 562         switch (tree->cnid) {
 563         case HFSPLUS_CAT_CNID:
 564                 class = CATALOG_BTREE_MUTEX;
 565                 break;
 566         case HFSPLUS_EXT_CNID:
 567                 class = EXTENTS_BTREE_MUTEX;
 568                 break;
 569         case HFSPLUS_ATTR_CNID:
 570                 class = ATTR_BTREE_MUTEX;
 571                 break;
 572         default:
 573                 BUG();
 574         }
 575         return class;
 576 }
 577
 578 /* compatibility */
 579 #define hfsp_mt2ut(t)           (struct timespec64){ .tv_sec = __hfsp_mt2ut(t) }
 580 #define hfsp_ut2mt(t)           __hfsp_ut2mt((t).tv_sec)
 581 #define hfsp_now2mt()           __hfsp_ut2mt(ktime_get_real_seconds())
 582
 583 #endif