LXR linux/fs/sysv/sysv.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _SYSV_H
   3#define _SYSV_H
   4
   5#include <linux/buffer_head.h>
   6
   7typedef __u16 __bitwise __fs16;
   8typedef __u32 __bitwise __fs32;
   9
  10#include <linux/sysv_fs.h>
  11
  12/*
  13 * SystemV/V7/Coherent super-block data in memory
  14 *
  15 * The SystemV/V7/Coherent superblock contains dynamic data (it gets modified
  16 * while the system is running). This is in contrast to the Minix and Berkeley
  17 * filesystems (where the superblock is never modified). This affects the
  18 * sync() operation: we must keep the superblock in a disk buffer and use this
  19 * one as our "working copy".
  20 */
  21
  22struct sysv_sb_info {
  23        struct super_block *s_sb;       /* VFS superblock */
  24        int            s_type;          /* file system type: FSTYPE_{XENIX|SYSV|COH} */
  25        char           s_bytesex;       /* bytesex (le/be/pdp) */
  26        unsigned int   s_inodes_per_block;      /* number of inodes per block */
  27        unsigned int   s_inodes_per_block_1;    /* inodes_per_block - 1 */
  28        unsigned int   s_inodes_per_block_bits; /* log2(inodes_per_block) */
  29        unsigned int   s_ind_per_block;         /* number of indirections per block */
  30        unsigned int   s_ind_per_block_bits;    /* log2(ind_per_block) */
  31        unsigned int   s_ind_per_block_2;       /* ind_per_block ^ 2 */
  32        unsigned int   s_toobig_block;          /* 10 + ipb + ipb^2 + ipb^3 */
  33        unsigned int   s_block_base;    /* physical block number of block 0 */
  34        unsigned short s_fic_size;      /* free inode cache size, NICINOD */
  35        unsigned short s_flc_size;      /* free block list chunk size, NICFREE */
  36        /* The superblock is kept in one or two disk buffers: */
  37        struct buffer_head *s_bh1;
  38        struct buffer_head *s_bh2;
  39        /* These are pointers into the disk buffer, to compensate for
  40           different superblock layout. */
  41        char *         s_sbd1;          /* entire superblock data, for part 1 */
  42        char *         s_sbd2;          /* entire superblock data, for part 2 */
  43        __fs16         *s_sb_fic_count; /* pointer to s_sbd->s_ninode */
  44        sysv_ino_t     *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
  45        __fs16         *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
  46        __fs16         *s_bcache_count; /* pointer to s_sbd->s_nfree */
  47        sysv_zone_t    *s_bcache;       /* pointer to s_sbd->s_free */
  48        __fs32         *s_free_blocks;  /* pointer to s_sbd->s_tfree */
  49        __fs32         *s_sb_time;      /* pointer to s_sbd->s_time */
  50        __fs32         *s_sb_state;     /* pointer to s_sbd->s_state, only FSTYPE_SYSV */
  51        /* We keep those superblock entities that don't change here;
  52           this saves us an indirection and perhaps a conversion. */
  53        u32            s_firstinodezone; /* index of first inode zone */
  54        u32            s_firstdatazone; /* same as s_sbd->s_isize */
  55        u32            s_ninodes;       /* total number of inodes */
  56        u32            s_ndatazones;    /* total number of data zones */
  57        u32            s_nzones;        /* same as s_sbd->s_fsize */
  58        u16            s_namelen;       /* max length of dir entry */
  59        int            s_forced_ro;
  60        struct mutex s_lock;
  61};
  62
  63/*
  64 * SystemV/V7/Coherent FS inode data in memory
  65 */
  66struct sysv_inode_info {
  67        __fs32          i_data[13];
  68        u32             i_dir_start_lookup;
  69        struct inode    vfs_inode;
  70};
  71
  72
  73static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
  74{
  75        return container_of(inode, struct sysv_inode_info, vfs_inode);
  76}
  77
  78static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
  79{
  80        return sb->s_fs_info;
  81}
  82
  83
  84/* identify the FS in memory */
  85enum {
  86        FSTYPE_NONE = 0,
  87        FSTYPE_XENIX,
  88        FSTYPE_SYSV4,
  89        FSTYPE_SYSV2,
  90        FSTYPE_COH,
  91        FSTYPE_V7,
  92        FSTYPE_AFS,
  93        FSTYPE_END,
  94};
  95
  96#define SYSV_MAGIC_BASE         0x012FF7B3
  97
  98#define XENIX_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_XENIX)
  99#define SYSV4_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
 100#define SYSV2_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
 101#define COH_SUPER_MAGIC         (SYSV_MAGIC_BASE+FSTYPE_COH)
 102
 103
 104/* Admissible values for i_nlink: 0.._LINK_MAX */
 105enum {
 106        XENIX_LINK_MAX  =       126,    /* ?? */
 107        SYSV_LINK_MAX   =       126,    /* 127? 251? */
 108        V7_LINK_MAX     =       126,    /* ?? */
 109        COH_LINK_MAX    =       10000,
 110};
 111
 112
 113static inline void dirty_sb(struct super_block *sb)
 114{
 115        struct sysv_sb_info *sbi = SYSV_SB(sb);
 116
 117        mark_buffer_dirty(sbi->s_bh1);
 118        if (sbi->s_bh1 != sbi->s_bh2)
 119                mark_buffer_dirty(sbi->s_bh2);
 120}
 121
 122
 123/* ialloc.c */
 124extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
 125                        struct buffer_head **);
 126extern struct inode * sysv_new_inode(const struct inode *, umode_t);
 127extern void sysv_free_inode(struct inode *);
 128extern unsigned long sysv_count_free_inodes(struct super_block *);
 129
 130/* balloc.c */
 131extern sysv_zone_t sysv_new_block(struct super_block *);
 132extern void sysv_free_block(struct super_block *, sysv_zone_t);
 133extern unsigned long sysv_count_free_blocks(struct super_block *);
 134
 135/* itree.c */
 136extern void sysv_truncate(struct inode *);
 137extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 138
 139/* inode.c */
 140extern struct inode *sysv_iget(struct super_block *, unsigned int);
 141extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
 142extern int sysv_sync_inode(struct inode *);
 143extern void sysv_set_inode(struct inode *, dev_t);
 144extern int sysv_getattr(const struct path *, struct kstat *, u32, unsigned int);
 145extern int sysv_init_icache(void);
 146extern void sysv_destroy_icache(void);
 147
 148
 149/* dir.c */
 150extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
 151extern int sysv_add_link(struct dentry *, struct inode *);
 152extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
 153extern int sysv_make_empty(struct inode *, struct inode *);
 154extern int sysv_empty_dir(struct inode *);
 155extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
 156                        struct inode *);
 157extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
 158extern ino_t sysv_inode_by_name(struct dentry *);
 159
 160
 161extern const struct inode_operations sysv_file_inode_operations;
 162extern const struct inode_operations sysv_dir_inode_operations;
 163extern const struct file_operations sysv_file_operations;
 164extern const struct file_operations sysv_dir_operations;
 165extern const struct address_space_operations sysv_aops;
 166extern const struct super_operations sysv_sops;
 167
 168
 169enum {
 170        BYTESEX_LE,
 171        BYTESEX_PDP,
 172        BYTESEX_BE,
 173};
 174
 175static inline u32 PDP_swab(u32 x)
 176{
 177#ifdef __LITTLE_ENDIAN
 178        return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
 179#else
 180#ifdef __BIG_ENDIAN
 181        return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
 182#else
 183#error BYTESEX
 184#endif
 185#endif
 186}
 187
 188static inline __u32 fs32_to_cpu(struct sysv_sb_info *sbi, __fs32 n)
 189{
 190        if (sbi->s_bytesex == BYTESEX_PDP)
 191                return PDP_swab((__force __u32)n);
 192        else if (sbi->s_bytesex == BYTESEX_LE)
 193                return le32_to_cpu((__force __le32)n);
 194        else
 195                return be32_to_cpu((__force __be32)n);
 196}
 197
 198static inline __fs32 cpu_to_fs32(struct sysv_sb_info *sbi, __u32 n)
 199{
 200        if (sbi->s_bytesex == BYTESEX_PDP)
 201                return (__force __fs32)PDP_swab(n);
 202        else if (sbi->s_bytesex == BYTESEX_LE)
 203                return (__force __fs32)cpu_to_le32(n);
 204        else
 205                return (__force __fs32)cpu_to_be32(n);
 206}
 207
 208static inline __fs32 fs32_add(struct sysv_sb_info *sbi, __fs32 *n, int d)
 209{
 210        if (sbi->s_bytesex == BYTESEX_PDP)
 211                *(__u32*)n = PDP_swab(PDP_swab(*(__u32*)n)+d);
 212        else if (sbi->s_bytesex == BYTESEX_LE)
 213                le32_add_cpu((__le32 *)n, d);
 214        else
 215                be32_add_cpu((__be32 *)n, d);
 216        return *n;
 217}
 218
 219static inline __u16 fs16_to_cpu(struct sysv_sb_info *sbi, __fs16 n)
 220{
 221        if (sbi->s_bytesex != BYTESEX_BE)
 222                return le16_to_cpu((__force __le16)n);
 223        else
 224                return be16_to_cpu((__force __be16)n);
 225}
 226
 227static inline __fs16 cpu_to_fs16(struct sysv_sb_info *sbi, __u16 n)
 228{
 229        if (sbi->s_bytesex != BYTESEX_BE)
 230                return (__force __fs16)cpu_to_le16(n);
 231        else
 232                return (__force __fs16)cpu_to_be16(n);
 233}
 234
 235static inline __fs16 fs16_add(struct sysv_sb_info *sbi, __fs16 *n, int d)
 236{
 237        if (sbi->s_bytesex != BYTESEX_BE)
 238                le16_add_cpu((__le16 *)n, d);
 239        else
 240                be16_add_cpu((__be16 *)n, d);
 241        return *n;
 242}
 243
 244#endif /* _SYSV_H */
 245