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         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  */
  66 struct sysv_inode_info {
  67         __fs32          i_data[13];
  68         u32             i_dir_start_lookup;
  69         struct inode    vfs_inode;
  70 };
  71
  72
  73 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
  74 {
  75         return container_of(inode, struct sysv_inode_info, vfs_inode);
  76 }
  77
  78 static 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 */
  85 enum {
  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 */
 105 enum {
 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
 113 static 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 */
 124 extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
 125                         struct buffer_head **);
 126 extern struct inode * sysv_new_inode(const struct inode *, umode_t);
 127 extern void sysv_free_inode(struct inode *);
 128 extern unsigned long sysv_count_free_inodes(struct super_block *);
 129
 130 /* balloc.c */
 131 extern sysv_zone_t sysv_new_block(struct super_block *);
 132 extern void sysv_free_block(struct super_block *, sysv_zone_t);
 133 extern unsigned long sysv_count_free_blocks(struct super_block *);
 134
 135 /* itree.c */
 136 extern void sysv_truncate(struct inode *);
 137 extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 138
 139 /* inode.c */
 140 extern struct inode *sysv_iget(struct super_block *, unsigned int);
 141 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
 142 extern int sysv_sync_inode(struct inode *);
 143 extern void sysv_set_inode(struct inode *, dev_t);
 144 extern int sysv_getattr(const struct path *, struct kstat *, u32, unsigned int);
 145 extern int sysv_init_icache(void);
 146 extern void sysv_destroy_icache(void);
 147
 148
 149 /* dir.c */
 150 extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
 151 extern int sysv_add_link(struct dentry *, struct inode *);
 152 extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
 153 extern int sysv_make_empty(struct inode *, struct inode *);
 154 extern int sysv_empty_dir(struct inode *);
 155 extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
 156                         struct inode *);
 157 extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
 158 extern ino_t sysv_inode_by_name(struct dentry *);
 159
 160
 161 extern const struct inode_operations sysv_file_inode_operations;
 162 extern const struct inode_operations sysv_dir_inode_operations;
 163 extern const struct file_operations sysv_file_operations;
 164 extern const struct file_operations sysv_dir_operations;
 165 extern const struct address_space_operations sysv_aops;
 166 extern const struct super_operations sysv_sops;
 167
 168
 169 enum {
 170         BYTESEX_LE,
 171         BYTESEX_PDP,
 172         BYTESEX_BE,
 173 };
 174
 175 static 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
 188 static 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
 198 static 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
 208 static 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
 219 static 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
 227 static 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
 235 static 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 */