LXR linux/fs/hpfs/hpfs

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 *  linux/fs/hpfs/hpfs_fn.h
   4 *
   5 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   6 *
   7 *  function headers
   8 */
   9
  10//#define DBG
  11//#define DEBUG_LOCKS
  12#ifdef pr_fmt
  13#undef pr_fmt
  14#endif
  15
  16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18#include <linux/mutex.h>
  19#include <linux/pagemap.h>
  20#include <linux/buffer_head.h>
  21#include <linux/slab.h>
  22#include <linux/sched/signal.h>
  23#include <linux/blkdev.h>
  24#include <asm/unaligned.h>
  25
  26#include "hpfs.h"
  27
  28#define EIOERROR  EIO
  29#define EFSERROR  EUCLEAN
  30
  31#define ANODE_ALLOC_FWD 512
  32#define FNODE_ALLOC_FWD 0
  33#define ALLOC_FWD_MIN   16
  34#define ALLOC_FWD_MAX   128
  35#define ALLOC_M         1
  36#define FNODE_RD_AHEAD  16
  37#define ANODE_RD_AHEAD  0
  38#define DNODE_RD_AHEAD  72
  39#define COUNT_RD_AHEAD  62
  40
  41#define FREE_DNODES_ADD 58
  42#define FREE_DNODES_DEL 29
  43
  44#define CHKCOND(x,y) if (!(x)) printk y
  45
  46struct hpfs_inode_info {
  47        loff_t mmu_private;
  48        ino_t i_parent_dir;     /* (directories) gives fnode of parent dir */
  49        unsigned i_dno;         /* (directories) root dnode */
  50        unsigned i_dpos;        /* (directories) temp for readdir */
  51        unsigned i_dsubdno;     /* (directories) temp for readdir */
  52        unsigned i_file_sec;    /* (files) minimalist cache of alloc info */
  53        unsigned i_disk_sec;    /* (files) minimalist cache of alloc info */
  54        unsigned i_n_secs;      /* (files) minimalist cache of alloc info */
  55        unsigned i_ea_size;     /* size of extended attributes */
  56        unsigned i_ea_mode : 1; /* file's permission is stored in ea */
  57        unsigned i_ea_uid : 1;  /* file's uid is stored in ea */
  58        unsigned i_ea_gid : 1;  /* file's gid is stored in ea */
  59        unsigned i_dirty : 1;
  60        loff_t **i_rddir_off;
  61        struct inode vfs_inode;
  62};
  63
  64struct hpfs_sb_info {
  65        struct mutex hpfs_mutex;        /* global hpfs lock */
  66        ino_t sb_root;                  /* inode number of root dir */
  67        unsigned sb_fs_size;            /* file system size, sectors */
  68        unsigned sb_bitmaps;            /* sector number of bitmap list */
  69        unsigned sb_dirband_start;      /* directory band start sector */
  70        unsigned sb_dirband_size;       /* directory band size, dnodes */
  71        unsigned sb_dmap;               /* sector number of dnode bit map */
  72        unsigned sb_n_free;             /* free blocks for statfs, or -1 */
  73        unsigned sb_n_free_dnodes;      /* free dnodes for statfs, or -1 */
  74        kuid_t sb_uid;                  /* uid from mount options */
  75        kgid_t sb_gid;                  /* gid from mount options */
  76        umode_t sb_mode;                /* mode from mount options */
  77        unsigned sb_eas : 2;            /* eas: 0-ignore, 1-ro, 2-rw */
  78        unsigned sb_err : 2;            /* on errs: 0-cont, 1-ro, 2-panic */
  79        unsigned sb_chk : 2;            /* checks: 0-no, 1-normal, 2-strict */
  80        unsigned sb_lowercase : 1;      /* downcase filenames hackery */
  81        unsigned sb_was_error : 1;      /* there was an error, set dirty flag */
  82        unsigned sb_chkdsk : 2;         /* chkdsk: 0-no, 1-on errs, 2-allways */
  83        unsigned char *sb_cp_table;     /* code page tables: */
  84                                        /*      128 bytes uppercasing table & */
  85                                        /*      128 bytes lowercasing table */
  86        __le32 *sb_bmp_dir;             /* main bitmap directory */
  87        unsigned sb_c_bitmap;           /* current bitmap */
  88        unsigned sb_max_fwd_alloc;      /* max forwad allocation */
  89        int sb_timeshift;
  90        struct rcu_head rcu;
  91
  92        unsigned n_hotfixes;
  93        secno hotfix_from[256];
  94        secno hotfix_to[256];
  95};
  96
  97/* Four 512-byte buffers and the 2k block obtained by concatenating them */
  98
  99struct quad_buffer_head {
 100        struct buffer_head *bh[4];
 101        void *data;
 102};
 103
 104/* The b-tree down pointer from a dir entry */
 105
 106static inline dnode_secno de_down_pointer (struct hpfs_dirent *de)
 107{
 108  CHKCOND(de->down,("HPFS: de_down_pointer: !de->down\n"));
 109  return le32_to_cpu(*(__le32 *) ((void *) de + le16_to_cpu(de->length) - 4));
 110}
 111
 112/* The first dir entry in a dnode */
 113
 114static inline struct hpfs_dirent *dnode_first_de (struct dnode *dnode)
 115{
 116  return (void *) dnode->dirent;
 117}
 118
 119/* The end+1 of the dir entries */
 120
 121static inline struct hpfs_dirent *dnode_end_de (struct dnode *dnode)
 122{
 123  CHKCOND(le32_to_cpu(dnode->first_free)>=0x14 && le32_to_cpu(dnode->first_free)<=0xa00,("HPFS: dnode_end_de: dnode->first_free = %x\n",(unsigned)le32_to_cpu(dnode->first_free)));
 124  return (void *) dnode + le32_to_cpu(dnode->first_free);
 125}
 126
 127/* The dir entry after dir entry de */
 128
 129static inline struct hpfs_dirent *de_next_de (struct hpfs_dirent *de)
 130{
 131  CHKCOND(le16_to_cpu(de->length)>=0x20 && le16_to_cpu(de->length)<0x800,("HPFS: de_next_de: de->length = %x\n",(unsigned)le16_to_cpu(de->length)));
 132  return (void *) de + le16_to_cpu(de->length);
 133}
 134
 135static inline struct extended_attribute *fnode_ea(struct fnode *fnode)
 136{
 137        return (struct extended_attribute *)((char *)fnode + le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s));
 138}
 139
 140static inline struct extended_attribute *fnode_end_ea(struct fnode *fnode)
 141{
 142        return (struct extended_attribute *)((char *)fnode + le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s));
 143}
 144
 145static unsigned ea_valuelen(struct extended_attribute *ea)
 146{
 147        return ea->valuelen_lo + 256 * ea->valuelen_hi;
 148}
 149
 150static inline struct extended_attribute *next_ea(struct extended_attribute *ea)
 151{
 152        return (struct extended_attribute *)((char *)ea + 5 + ea->namelen + ea_valuelen(ea));
 153}
 154
 155static inline secno ea_sec(struct extended_attribute *ea)
 156{
 157        return le32_to_cpu(get_unaligned((__le32 *)((char *)ea + 9 + ea->namelen)));
 158}
 159
 160static inline secno ea_len(struct extended_attribute *ea)
 161{
 162        return le32_to_cpu(get_unaligned((__le32 *)((char *)ea + 5 + ea->namelen)));
 163}
 164
 165static inline char *ea_data(struct extended_attribute *ea)
 166{
 167        return (char *)((char *)ea + 5 + ea->namelen);
 168}
 169
 170static inline unsigned de_size(int namelen, secno down_ptr)
 171{
 172        return ((0x1f + namelen + 3) & ~3) + (down_ptr ? 4 : 0);
 173}
 174
 175static inline void copy_de(struct hpfs_dirent *dst, struct hpfs_dirent *src)
 176{
 177        int a;
 178        int n;
 179        if (!dst || !src) return;
 180        a = dst->down;
 181        n = dst->not_8x3;
 182        memcpy((char *)dst + 2, (char *)src + 2, 28);
 183        dst->down = a;
 184        dst->not_8x3 = n;
 185}
 186
 187static inline unsigned tstbits(__le32 *bmp, unsigned b, unsigned n)
 188{
 189        int i;
 190        if ((b >= 0x4000) || (b + n - 1 >= 0x4000)) return n;
 191        if (!((le32_to_cpu(bmp[(b & 0x3fff) >> 5]) >> (b & 0x1f)) & 1)) return 1;
 192        for (i = 1; i < n; i++)
 193                if (!((le32_to_cpu(bmp[((b+i) & 0x3fff) >> 5]) >> ((b+i) & 0x1f)) & 1))
 194                        return i + 1;
 195        return 0;
 196}
 197
 198/* alloc.c */
 199
 200int hpfs_chk_sectors(struct super_block *, secno, int, char *);
 201secno hpfs_alloc_sector(struct super_block *, secno, unsigned, int);
 202int hpfs_alloc_if_possible(struct super_block *, secno);
 203void hpfs_free_sectors(struct super_block *, secno, unsigned);
 204int hpfs_check_free_dnodes(struct super_block *, int);
 205void hpfs_free_dnode(struct super_block *, secno);
 206struct dnode *hpfs_alloc_dnode(struct super_block *, secno, dnode_secno *, struct quad_buffer_head *);
 207struct fnode *hpfs_alloc_fnode(struct super_block *, secno, fnode_secno *, struct buffer_head **);
 208struct anode *hpfs_alloc_anode(struct super_block *, secno, anode_secno *, struct buffer_head **);
 209int hpfs_trim_fs(struct super_block *, u64, u64, u64, unsigned *);
 210
 211/* anode.c */
 212
 213secno hpfs_bplus_lookup(struct super_block *, struct inode *, struct bplus_header *, unsigned, struct buffer_head *);
 214secno hpfs_add_sector_to_btree(struct super_block *, secno, int, unsigned);
 215void hpfs_remove_btree(struct super_block *, struct bplus_header *);
 216int hpfs_ea_read(struct super_block *, secno, int, unsigned, unsigned, char *);
 217int hpfs_ea_write(struct super_block *, secno, int, unsigned, unsigned, const char *);
 218void hpfs_ea_remove(struct super_block *, secno, int, unsigned);
 219void hpfs_truncate_btree(struct super_block *, secno, int, unsigned);
 220void hpfs_remove_fnode(struct super_block *, fnode_secno fno);
 221
 222/* buffer.c */
 223
 224secno hpfs_search_hotfix_map(struct super_block *s, secno sec);
 225unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n);
 226void hpfs_prefetch_sectors(struct super_block *, unsigned, int);
 227void *hpfs_map_sector(struct super_block *, unsigned, struct buffer_head **, int);
 228void *hpfs_get_sector(struct super_block *, unsigned, struct buffer_head **);
 229void *hpfs_map_4sectors(struct super_block *, unsigned, struct quad_buffer_head *, int);
 230void *hpfs_get_4sectors(struct super_block *, unsigned, struct quad_buffer_head *);
 231void hpfs_brelse4(struct quad_buffer_head *);
 232void hpfs_mark_4buffers_dirty(struct quad_buffer_head *);
 233
 234/* dentry.c */
 235
 236extern const struct dentry_operations hpfs_dentry_operations;
 237
 238/* dir.c */
 239
 240struct dentry *hpfs_lookup(struct inode *, struct dentry *, unsigned int);
 241extern const struct file_operations hpfs_dir_ops;
 242
 243/* dnode.c */
 244
 245int hpfs_add_pos(struct inode *, loff_t *);
 246void hpfs_del_pos(struct inode *, loff_t *);
 247struct hpfs_dirent *hpfs_add_de(struct super_block *, struct dnode *,
 248                                const unsigned char *, unsigned, secno);
 249int hpfs_add_dirent(struct inode *, const unsigned char *, unsigned,
 250                    struct hpfs_dirent *);
 251int hpfs_remove_dirent(struct inode *, dnode_secno, struct hpfs_dirent *, struct quad_buffer_head *, int);
 252void hpfs_count_dnodes(struct super_block *, dnode_secno, int *, int *, int *);
 253dnode_secno hpfs_de_as_down_as_possible(struct super_block *, dnode_secno dno);
 254struct hpfs_dirent *map_pos_dirent(struct inode *, loff_t *, struct quad_buffer_head *);
 255struct hpfs_dirent *map_dirent(struct inode *, dnode_secno,
 256                               const unsigned char *, unsigned, dnode_secno *,
 257                               struct quad_buffer_head *);
 258void hpfs_remove_dtree(struct super_block *, dnode_secno);
 259struct hpfs_dirent *map_fnode_dirent(struct super_block *, fnode_secno, struct fnode *, struct quad_buffer_head *);
 260
 261/* ea.c */
 262
 263void hpfs_ea_ext_remove(struct super_block *, secno, int, unsigned);
 264int hpfs_read_ea(struct super_block *, struct fnode *, char *, char *, int);
 265char *hpfs_get_ea(struct super_block *, struct fnode *, char *, int *);
 266void hpfs_set_ea(struct inode *, struct fnode *, const char *,
 267                 const char *, int);
 268
 269/* file.c */
 270
 271int hpfs_file_fsync(struct file *, loff_t, loff_t, int);
 272void hpfs_truncate(struct inode *);
 273extern const struct file_operations hpfs_file_ops;
 274extern const struct inode_operations hpfs_file_iops;
 275extern const struct address_space_operations hpfs_aops;
 276
 277/* inode.c */
 278
 279void hpfs_init_inode(struct inode *);
 280void hpfs_read_inode(struct inode *);
 281void hpfs_write_inode(struct inode *);
 282void hpfs_write_inode_nolock(struct inode *);
 283int hpfs_setattr(struct dentry *, struct iattr *);
 284void hpfs_write_if_changed(struct inode *);
 285void hpfs_evict_inode(struct inode *);
 286
 287/* map.c */
 288
 289__le32 *hpfs_map_dnode_bitmap(struct super_block *, struct quad_buffer_head *);
 290__le32 *hpfs_map_bitmap(struct super_block *, unsigned, struct quad_buffer_head *, char *);
 291void hpfs_prefetch_bitmap(struct super_block *, unsigned);
 292unsigned char *hpfs_load_code_page(struct super_block *, secno);
 293__le32 *hpfs_load_bitmap_directory(struct super_block *, secno bmp);
 294void hpfs_load_hotfix_map(struct super_block *s, struct hpfs_spare_block *spareblock);
 295struct fnode *hpfs_map_fnode(struct super_block *s, ino_t, struct buffer_head **);
 296struct anode *hpfs_map_anode(struct super_block *s, anode_secno, struct buffer_head **);
 297struct dnode *hpfs_map_dnode(struct super_block *s, dnode_secno, struct quad_buffer_head *);
 298dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino);
 299
 300/* name.c */
 301
 302unsigned char hpfs_upcase(unsigned char *, unsigned char);
 303int hpfs_chk_name(const unsigned char *, unsigned *);
 304unsigned char *hpfs_translate_name(struct super_block *, unsigned char *, unsigned, int, int);
 305int hpfs_compare_names(struct super_block *, const unsigned char *, unsigned,
 306                       const unsigned char *, unsigned, int);
 307int hpfs_is_name_long(const unsigned char *, unsigned);
 308void hpfs_adjust_length(const unsigned char *, unsigned *);
 309
 310/* namei.c */
 311
 312extern const struct inode_operations hpfs_dir_iops;
 313extern const struct address_space_operations hpfs_symlink_aops;
 314
 315static inline struct hpfs_inode_info *hpfs_i(struct inode *inode)
 316{
 317        return container_of(inode, struct hpfs_inode_info, vfs_inode);
 318}
 319
 320static inline struct hpfs_sb_info *hpfs_sb(struct super_block *sb)
 321{
 322        return sb->s_fs_info;
 323}
 324
 325/* super.c */
 326
 327__printf(2, 3)
 328void hpfs_error(struct super_block *, const char *, ...);
 329int hpfs_stop_cycles(struct super_block *, int, int *, int *, char *);
 330unsigned hpfs_get_free_dnodes(struct super_block *);
 331long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 332
 333/*
 334 * local time (HPFS) to GMT (Unix)
 335 */
 336
 337static inline time64_t local_to_gmt(struct super_block *s, time32_t t)
 338{
 339        extern struct timezone sys_tz;
 340        return t + sys_tz.tz_minuteswest * 60 + hpfs_sb(s)->sb_timeshift;
 341}
 342
 343static inline time32_t gmt_to_local(struct super_block *s, time64_t t)
 344{
 345        extern struct timezone sys_tz;
 346        t = t - sys_tz.tz_minuteswest * 60 - hpfs_sb(s)->sb_timeshift;
 347
 348        return clamp_t(time64_t, t, 0, U32_MAX);
 349}
 350
 351static inline time32_t local_get_seconds(struct super_block *s)
 352{
 353        return gmt_to_local(s, ktime_get_real_seconds());
 354}
 355
 356/*
 357 * Locking:
 358 *
 359 * hpfs_lock() locks the whole filesystem. It must be taken
 360 * on any method called by the VFS.
 361 *
 362 * We don't do any per-file locking anymore, it is hard to
 363 * review and HPFS is not performance-sensitive anyway.
 364 */
 365static inline void hpfs_lock(struct super_block *s)
 366{
 367        struct hpfs_sb_info *sbi = hpfs_sb(s);
 368        mutex_lock(&sbi->hpfs_mutex);
 369}
 370
 371static inline void hpfs_unlock(struct super_block *s)
 372{
 373        struct hpfs_sb_info *sbi = hpfs_sb(s);
 374        mutex_unlock(&sbi->hpfs_mutex);
 375}
 376
 377static inline void hpfs_lock_assert(struct super_block *s)
 378{
 379        struct hpfs_sb_info *sbi = hpfs_sb(s);
 380        WARN_ON(!mutex_is_locked(&sbi->hpfs_mutex));
 381}
 382