linux/fs/sysv/sysv.h
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   1#ifndef _SYSV_H
   2#define _SYSV_H
   3
   4#include <linux/buffer_head.h>
   5
   6typedef __u16 __bitwise __fs16;
   7typedef __u32 __bitwise __fs32;
   8
   9#include <linux/sysv_fs.h>
  10
  11/*
  12 * SystemV/V7/Coherent super-block data in memory
  13 *
  14 * The SystemV/V7/Coherent superblock contains dynamic data (it gets modified
  15 * while the system is running). This is in contrast to the Minix and Berkeley
  16 * filesystems (where the superblock is never modified). This affects the
  17 * sync() operation: we must keep the superblock in a disk buffer and use this
  18 * one as our "working copy".
  19 */
  20
  21struct sysv_sb_info {
  22        struct super_block *s_sb;       /* VFS superblock */
  23        int            s_type;          /* file system type: FSTYPE_{XENIX|SYSV|COH} */
  24        char           s_bytesex;       /* bytesex (le/be/pdp) */
  25        char           s_truncate;      /* if 1: names > SYSV_NAMELEN chars are truncated */
  26                                        /* if 0: they are disallowed (ENAMETOOLONG) */
  27        unsigned int   s_inodes_per_block;      /* number of inodes per block */
  28        unsigned int   s_inodes_per_block_1;    /* inodes_per_block - 1 */
  29        unsigned int   s_inodes_per_block_bits; /* log2(inodes_per_block) */
  30        unsigned int   s_ind_per_block;         /* number of indirections per block */
  31        unsigned int   s_ind_per_block_bits;    /* log2(ind_per_block) */
  32        unsigned int   s_ind_per_block_2;       /* ind_per_block ^ 2 */
  33        unsigned int   s_toobig_block;          /* 10 + ipb + ipb^2 + ipb^3 */
  34        unsigned int   s_block_base;    /* physical block number of block 0 */
  35        unsigned short s_fic_size;      /* free inode cache size, NICINOD */
  36        unsigned short s_flc_size;      /* free block list chunk size, NICFREE */
  37        /* The superblock is kept in one or two disk buffers: */
  38        struct buffer_head *s_bh1;
  39        struct buffer_head *s_bh2;
  40        /* These are pointers into the disk buffer, to compensate for
  41           different superblock layout. */
  42        char *         s_sbd1;          /* entire superblock data, for part 1 */
  43        char *         s_sbd2;          /* entire superblock data, for part 2 */
  44        __fs16         *s_sb_fic_count; /* pointer to s_sbd->s_ninode */
  45        sysv_ino_t     *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
  46        __fs16         *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
  47        __fs16         *s_bcache_count; /* pointer to s_sbd->s_nfree */
  48        sysv_zone_t    *s_bcache;       /* pointer to s_sbd->s_free */
  49        __fs32         *s_free_blocks;  /* pointer to s_sbd->s_tfree */
  50        __fs32         *s_sb_time;      /* pointer to s_sbd->s_time */
  51        __fs32         *s_sb_state;     /* pointer to s_sbd->s_state, only FSTYPE_SYSV */
  52        /* We keep those superblock entities that don't change here;
  53           this saves us an indirection and perhaps a conversion. */
  54        u32            s_firstinodezone; /* index of first inode zone */
  55        u32            s_firstdatazone; /* same as s_sbd->s_isize */
  56        u32            s_ninodes;       /* total number of inodes */
  57        u32            s_ndatazones;    /* total number of data zones */
  58        u32            s_nzones;        /* same as s_sbd->s_fsize */
  59        u16            s_namelen;       /* max length of dir entry */
  60        int            s_forced_ro;
  61        struct mutex s_lock;
  62};
  63
  64/*
  65 * SystemV/V7/Coherent FS inode data in memory
  66 */
  67struct sysv_inode_info {
  68        __fs32          i_data[13];
  69        u32             i_dir_start_lookup;
  70        struct inode    vfs_inode;
  71};
  72
  73
  74static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
  75{
  76        return list_entry(inode, struct sysv_inode_info, vfs_inode);
  77}
  78
  79static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
  80{
  81        return sb->s_fs_info;
  82}
  83
  84
  85/* identify the FS in memory */
  86enum {
  87        FSTYPE_NONE = 0,
  88        FSTYPE_XENIX,
  89        FSTYPE_SYSV4,
  90        FSTYPE_SYSV2,
  91        FSTYPE_COH,
  92        FSTYPE_V7,
  93        FSTYPE_AFS,
  94        FSTYPE_END,
  95};
  96
  97#define SYSV_MAGIC_BASE         0x012FF7B3
  98
  99#define XENIX_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_XENIX)
 100#define SYSV4_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
 101#define SYSV2_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
 102#define COH_SUPER_MAGIC         (SYSV_MAGIC_BASE+FSTYPE_COH)
 103
 104
 105/* Admissible values for i_nlink: 0.._LINK_MAX */
 106enum {
 107        XENIX_LINK_MAX  =       126,    /* ?? */
 108        SYSV_LINK_MAX   =       126,    /* 127? 251? */
 109        V7_LINK_MAX     =       126,    /* ?? */
 110        COH_LINK_MAX    =       10000,
 111};
 112
 113
 114static inline void dirty_sb(struct super_block *sb)
 115{
 116        struct sysv_sb_info *sbi = SYSV_SB(sb);
 117
 118        mark_buffer_dirty(sbi->s_bh1);
 119        if (sbi->s_bh1 != sbi->s_bh2)
 120                mark_buffer_dirty(sbi->s_bh2);
 121}
 122
 123
 124/* ialloc.c */
 125extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
 126                        struct buffer_head **);
 127extern struct inode * sysv_new_inode(const struct inode *, umode_t);
 128extern void sysv_free_inode(struct inode *);
 129extern unsigned long sysv_count_free_inodes(struct super_block *);
 130
 131/* balloc.c */
 132extern sysv_zone_t sysv_new_block(struct super_block *);
 133extern void sysv_free_block(struct super_block *, sysv_zone_t);
 134extern unsigned long sysv_count_free_blocks(struct super_block *);
 135
 136/* itree.c */
 137extern void sysv_truncate(struct inode *);
 138extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 139
 140/* inode.c */
 141extern struct inode *sysv_iget(struct super_block *, unsigned int);
 142extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
 143extern int sysv_sync_inode(struct inode *);
 144extern void sysv_set_inode(struct inode *, dev_t);
 145extern int sysv_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 146extern int sysv_init_icache(void);
 147extern void sysv_destroy_icache(void);
 148
 149
 150/* dir.c */
 151extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
 152extern int sysv_add_link(struct dentry *, struct inode *);
 153extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
 154extern int sysv_make_empty(struct inode *, struct inode *);
 155extern int sysv_empty_dir(struct inode *);
 156extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
 157                        struct inode *);
 158extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
 159extern ino_t sysv_inode_by_name(struct dentry *);
 160
 161
 162extern const struct inode_operations sysv_file_inode_operations;
 163extern const struct inode_operations sysv_dir_inode_operations;
 164extern const struct inode_operations sysv_fast_symlink_inode_operations;
 165extern const struct file_operations sysv_file_operations;
 166extern const struct file_operations sysv_dir_operations;
 167extern const struct address_space_operations sysv_aops;
 168extern const struct super_operations sysv_sops;
 169extern const struct dentry_operations sysv_dentry_operations;
 170
 171
 172enum {
 173        BYTESEX_LE,
 174        BYTESEX_PDP,
 175        BYTESEX_BE,
 176};
 177
 178static inline u32 PDP_swab(u32 x)
 179{
 180#ifdef __LITTLE_ENDIAN
 181        return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
 182#else
 183#ifdef __BIG_ENDIAN
 184        return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
 185#else
 186#error BYTESEX
 187#endif
 188#endif
 189}
 190
 191static inline __u32 fs32_to_cpu(struct sysv_sb_info *sbi, __fs32 n)
 192{
 193        if (sbi->s_bytesex == BYTESEX_PDP)
 194                return PDP_swab((__force __u32)n);
 195        else if (sbi->s_bytesex == BYTESEX_LE)
 196                return le32_to_cpu((__force __le32)n);
 197        else
 198                return be32_to_cpu((__force __be32)n);
 199}
 200
 201static inline __fs32 cpu_to_fs32(struct sysv_sb_info *sbi, __u32 n)
 202{
 203        if (sbi->s_bytesex == BYTESEX_PDP)
 204                return (__force __fs32)PDP_swab(n);
 205        else if (sbi->s_bytesex == BYTESEX_LE)
 206                return (__force __fs32)cpu_to_le32(n);
 207        else
 208                return (__force __fs32)cpu_to_be32(n);
 209}
 210
 211static inline __fs32 fs32_add(struct sysv_sb_info *sbi, __fs32 *n, int d)
 212{
 213        if (sbi->s_bytesex == BYTESEX_PDP)
 214                *(__u32*)n = PDP_swab(PDP_swab(*(__u32*)n)+d);
 215        else if (sbi->s_bytesex == BYTESEX_LE)
 216                le32_add_cpu((__le32 *)n, d);
 217        else
 218                be32_add_cpu((__be32 *)n, d);
 219        return *n;
 220}
 221
 222static inline __u16 fs16_to_cpu(struct sysv_sb_info *sbi, __fs16 n)
 223{
 224        if (sbi->s_bytesex != BYTESEX_BE)
 225                return le16_to_cpu((__force __le16)n);
 226        else
 227                return be16_to_cpu((__force __be16)n);
 228}
 229
 230static inline __fs16 cpu_to_fs16(struct sysv_sb_info *sbi, __u16 n)
 231{
 232        if (sbi->s_bytesex != BYTESEX_BE)
 233                return (__force __fs16)cpu_to_le16(n);
 234        else
 235                return (__force __fs16)cpu_to_be16(n);
 236}
 237
 238static inline __fs16 fs16_add(struct sysv_sb_info *sbi, __fs16 *n, int d)
 239{
 240        if (sbi->s_bytesex != BYTESEX_BE)
 241                le16_add_cpu((__le16 *)n, d);
 242        else
 243                be16_add_cpu((__be16 *)n, d);
 244        return *n;
 245}
 246
 247#endif /* _SYSV_H */
 248
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