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
   7 typedef __u16 __bitwise __fs16;
   8 typedef __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
  22 struct 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         char           s_truncate;      /* if 1: names > SYSV_NAMELEN chars are truncated */
  27                                         /* if 0: they are disallowed (ENAMETOOLONG) */
  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         struct mutex s_lock;
  63 };
  64
  65 /*
  66  * SystemV/V7/Coherent FS inode data in memory
  67  */
  68 struct sysv_inode_info {
  69         __fs32          i_data[13];
  70         u32             i_dir_start_lookup;
  71         struct inode    vfs_inode;
  72 };
  73
  74
  75 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
  76 {
  77         return container_of(inode, struct sysv_inode_info, vfs_inode);
  78 }
  79
  80 static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
  81 {
  82         return sb->s_fs_info;
  83 }
  84
  85
  86 /* identify the FS in memory */
  87 enum {
  88         FSTYPE_NONE = 0,
  89         FSTYPE_XENIX,
  90         FSTYPE_SYSV4,
  91         FSTYPE_SYSV2,
  92         FSTYPE_COH,
  93         FSTYPE_V7,
  94         FSTYPE_AFS,
  95         FSTYPE_END,
  96 };
  97
  98 #define SYSV_MAGIC_BASE         0x012FF7B3
  99
 100 #define XENIX_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_XENIX)
 101 #define SYSV4_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
 102 #define SYSV2_SUPER_MAGIC       (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
 103 #define COH_SUPER_MAGIC         (SYSV_MAGIC_BASE+FSTYPE_COH)
 104
 105
 106 /* Admissible values for i_nlink: 0.._LINK_MAX */
 107 enum {
 108         XENIX_LINK_MAX  =       126,    /* ?? */
 109         SYSV_LINK_MAX   =       126,    /* 127? 251? */
 110         V7_LINK_MAX     =       126,    /* ?? */
 111         COH_LINK_MAX    =       10000,
 112 };
 113
 114
 115 static inline void dirty_sb(struct super_block *sb)
 116 {
 117         struct sysv_sb_info *sbi = SYSV_SB(sb);
 118
 119         mark_buffer_dirty(sbi->s_bh1);
 120         if (sbi->s_bh1 != sbi->s_bh2)
 121                 mark_buffer_dirty(sbi->s_bh2);
 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(const struct path *, struct kstat *, u32, unsigned int);
 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 file_operations sysv_file_operations;
 166 extern const struct file_operations sysv_dir_operations;
 167 extern const struct address_space_operations sysv_aops;
 168 extern const struct super_operations sysv_sops;
 169 extern const struct dentry_operations sysv_dentry_operations;
 170
 171
 172 enum {
 173         BYTESEX_LE,
 174         BYTESEX_PDP,
 175         BYTESEX_BE,
 176 };
 177
 178 static 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
 191 static 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
 201 static 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
 211 static 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
 222 static 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
 230 static 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
 238 static 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 */