fs/sysv/sysv.h

   1 #ifndef _SYSV_H
   2 #define _SYSV_H
   3
   4 #include <linux/buffer_head.h>
   5
   6 typedef __u16 __bitwise __fs16;
   7 typedef __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
  21 struct 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         nlink_t        s_link_max;      /* max number of hard links to a file */
  28         unsigned int   s_inodes_per_block;      /* number of inodes per block */
  29         unsigned int   s_inodes_per_block_1;    /* inodes_per_block - 1 */
  30         unsigned int   s_inodes_per_block_bits; /* log2(inodes_per_block) */
  31         unsigned int   s_ind_per_block;         /* number of indirections per block */
  32         unsigned int   s_ind_per_block_bits;    /* log2(ind_per_block) */
  33         unsigned int   s_ind_per_block_2;       /* ind_per_block ^ 2 */
  34         unsigned int   s_toobig_block;          /* 10 + ipb + ipb^2 + ipb^3 */
  35         unsigned int   s_block_base;    /* physical block number of block 0 */
  36         unsigned short s_fic_size;      /* free inode cache size, NICINOD */
  37         unsigned short s_flc_size;      /* free block list chunk size, NICFREE */
  38         /* The superblock is kept in one or two disk buffers: */
  39         struct buffer_head *s_bh1;
  40         struct buffer_head *s_bh2;
  41         /* These are pointers into the disk buffer, to compensate for
  42            different superblock layout. */
  43         char *         s_sbd1;          /* entire superblock data, for part 1 */
  44         char *         s_sbd2;          /* entire superblock data, for part 2 */
  45         __fs16         *s_sb_fic_count; /* pointer to s_sbd->s_ninode */
  46         sysv_ino_t     *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
  47         __fs16         *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
  48         __fs16         *s_bcache_count; /* pointer to s_sbd->s_nfree */
  49         sysv_zone_t    *s_bcache;       /* pointer to s_sbd->s_free */
  50         __fs32         *s_free_blocks;  /* pointer to s_sbd->s_tfree */
  51         __fs32         *s_sb_time;      /* pointer to s_sbd->s_time */
  52         __fs32         *s_sb_state;     /* pointer to s_sbd->s_state, only FSTYPE_SYSV */
  53         /* We keep those superblock entities that don't change here;
  54            this saves us an indirection and perhaps a conversion. */
  55         u32            s_firstinodezone; /* index of first inode zone */
  56         u32            s_firstdatazone; /* same as s_sbd->s_isize */
  57         u32            s_ninodes;       /* total number of inodes */
  58         u32            s_ndatazones;    /* total number of data zones */
  59         u32            s_nzones;        /* same as s_sbd->s_fsize */
  60         u16            s_namelen;       /* max length of dir entry */
  61         int            s_forced_ro;
  62 };
  63
  64 /*
  65  * SystemV/V7/Coherent FS inode data in memory
  66  */
  67 struct sysv_inode_info {
  68         __fs32          i_data[13];
  69         u32             i_dir_start_lookup;
  70         struct inode    vfs_inode;
  71 };
  72
  73
  74 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
  75 {
  76         return list_entry(inode, struct sysv_inode_info, vfs_inode);
  77 }
  78
  79 static 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 */
  86 enum {
  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 */
 106 enum {
 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
 114 static 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         sb->s_dirt = 1;
 122 }
 123
 124
 125 /* ialloc.c */
 126 extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
 127                         struct buffer_head **);
 128 extern struct inode * sysv_new_inode(const struct inode *, umode_t);
 129 extern void sysv_free_inode(struct inode *);
 130 extern unsigned long sysv_count_free_inodes(struct super_block *);
 131
 132 /* balloc.c */
 133 extern sysv_zone_t sysv_new_block(struct super_block *);
 134 extern void sysv_free_block(struct super_block *, sysv_zone_t);
 135 extern unsigned long sysv_count_free_blocks(struct super_block *);
 136
 137 /* itree.c */
 138 extern void sysv_truncate(struct inode *);
 139 extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 140
 141 /* inode.c */
 142 extern struct inode *sysv_iget(struct super_block *, unsigned int);
 143 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
 144 extern int sysv_sync_inode(struct inode *);
 145 extern void sysv_set_inode(struct inode *, dev_t);
 146 extern int sysv_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 147 extern int sysv_init_icache(void);
 148 extern void sysv_destroy_icache(void);
 149
 150
 151 /* dir.c */
 152 extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
 153 extern int sysv_add_link(struct dentry *, struct inode *);
 154 extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
 155 extern int sysv_make_empty(struct inode *, struct inode *);
 156 extern int sysv_empty_dir(struct inode *);
 157 extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
 158                         struct inode *);
 159 extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
 160 extern ino_t sysv_inode_by_name(struct dentry *);
 161
 162
 163 extern const struct inode_operations sysv_file_inode_operations;
 164 extern const struct inode_operations sysv_dir_inode_operations;
 165 extern const struct inode_operations sysv_fast_symlink_inode_operations;
 166 extern const struct file_operations sysv_file_operations;
 167 extern const struct file_operations sysv_dir_operations;
 168 extern const struct address_space_operations sysv_aops;
 169 extern const struct super_operations sysv_sops;
 170 extern const struct dentry_operations sysv_dentry_operations;
 171
 172
 173 enum {
 174         BYTESEX_LE,
 175         BYTESEX_PDP,
 176         BYTESEX_BE,
 177 };
 178
 179 static inline u32 PDP_swab(u32 x)
 180 {
 181 #ifdef __LITTLE_ENDIAN
 182         return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
 183 #else
 184 #ifdef __BIG_ENDIAN
 185         return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
 186 #else
 187 #error BYTESEX
 188 #endif
 189 #endif
 190 }
 191
 192 static inline __u32 fs32_to_cpu(struct sysv_sb_info *sbi, __fs32 n)
 193 {
 194         if (sbi->s_bytesex == BYTESEX_PDP)
 195                 return PDP_swab((__force __u32)n);
 196         else if (sbi->s_bytesex == BYTESEX_LE)
 197                 return le32_to_cpu((__force __le32)n);
 198         else
 199                 return be32_to_cpu((__force __be32)n);
 200 }
 201
 202 static inline __fs32 cpu_to_fs32(struct sysv_sb_info *sbi, __u32 n)
 203 {
 204         if (sbi->s_bytesex == BYTESEX_PDP)
 205                 return (__force __fs32)PDP_swab(n);
 206         else if (sbi->s_bytesex == BYTESEX_LE)
 207                 return (__force __fs32)cpu_to_le32(n);
 208         else
 209                 return (__force __fs32)cpu_to_be32(n);
 210 }
 211
 212 static inline __fs32 fs32_add(struct sysv_sb_info *sbi, __fs32 *n, int d)
 213 {
 214         if (sbi->s_bytesex == BYTESEX_PDP)
 215                 *(__u32*)n = PDP_swab(PDP_swab(*(__u32*)n)+d);
 216         else if (sbi->s_bytesex == BYTESEX_LE)
 217                 le32_add_cpu((__le32 *)n, d);
 218         else
 219                 be32_add_cpu((__be32 *)n, d);
 220         return *n;
 221 }
 222
 223 static inline __u16 fs16_to_cpu(struct sysv_sb_info *sbi, __fs16 n)
 224 {
 225         if (sbi->s_bytesex != BYTESEX_BE)
 226                 return le16_to_cpu((__force __le16)n);
 227         else
 228                 return be16_to_cpu((__force __be16)n);
 229 }
 230
 231 static inline __fs16 cpu_to_fs16(struct sysv_sb_info *sbi, __u16 n)
 232 {
 233         if (sbi->s_bytesex != BYTESEX_BE)
 234                 return (__force __fs16)cpu_to_le16(n);
 235         else
 236                 return (__force __fs16)cpu_to_be16(n);
 237 }
 238
 239 static inline __fs16 fs16_add(struct sysv_sb_info *sbi, __fs16 *n, int d)
 240 {
 241         if (sbi->s_bytesex != BYTESEX_BE)
 242                 le16_add_cpu((__le16 *)n, d);
 243         else
 244                 be16_add_cpu((__be16 *)n, d);
 245         return *n;
 246 }
 247
 248 #endif /* _SYSV_H */