fs/efs/efs.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (c) 1999 Al Smith, <Al.Smith@aeschi.ch.eu.org>
   4  *
   5  * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
   6  * Portions derived from IRIX header files (c) 1988 Silicon Graphics
   7  */
   8 #ifndef _EFS_EFS_H_
   9 #define _EFS_EFS_H_
  10
  11 #ifdef pr_fmt
  12 #undef pr_fmt
  13 #endif
  14
  15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17 #include <linux/fs.h>
  18 #include <linux/uaccess.h>
  19
  20 #define EFS_VERSION "1.0a"
  21
  22 /* 1 block is 512 bytes */
  23 #define EFS_BLOCKSIZE_BITS      9
  24 #define EFS_BLOCKSIZE           (1 << EFS_BLOCKSIZE_BITS)
  25
  26 typedef int32_t         efs_block_t;
  27 typedef uint32_t        efs_ino_t;
  28
  29 #define EFS_DIRECTEXTENTS       12
  30
  31 /*
  32  * layout of an extent, in memory and on disk. 8 bytes exactly.
  33  */
  34 typedef union extent_u {
  35         unsigned char raw[8];
  36         struct extent_s {
  37                 unsigned int    ex_magic:8;     /* magic # (zero) */
  38                 unsigned int    ex_bn:24;       /* basic block */
  39                 unsigned int    ex_length:8;    /* numblocks in this extent */
  40                 unsigned int    ex_offset:24;   /* logical offset into file */
  41         } cooked;
  42 } efs_extent;
  43
  44 typedef struct edevs {
  45         __be16          odev;
  46         __be32          ndev;
  47 } efs_devs;
  48
  49 /*
  50  * extent based filesystem inode as it appears on disk.  The efs inode
  51  * is exactly 128 bytes long.
  52  */
  53 struct  efs_dinode {
  54         __be16          di_mode;        /* mode and type of file */
  55         __be16          di_nlink;       /* number of links to file */
  56         __be16          di_uid;         /* owner's user id */
  57         __be16          di_gid;         /* owner's group id */
  58         __be32          di_size;        /* number of bytes in file */
  59         __be32          di_atime;       /* time last accessed */
  60         __be32          di_mtime;       /* time last modified */
  61         __be32          di_ctime;       /* time created */
  62         __be32          di_gen;         /* generation number */
  63         __be16          di_numextents;  /* # of extents */
  64         u_char          di_version;     /* version of inode */
  65         u_char          di_spare;       /* spare - used by AFS */
  66         union di_addr {
  67                 efs_extent      di_extents[EFS_DIRECTEXTENTS];
  68                 efs_devs        di_dev; /* device for IFCHR/IFBLK */
  69         } di_u;
  70 };
  71
  72 /* efs inode storage in memory */
  73 struct efs_inode_info {
  74         int             numextents;
  75         int             lastextent;
  76
  77         efs_extent      extents[EFS_DIRECTEXTENTS];
  78         struct inode    vfs_inode;
  79 };
  80
  81 #include <linux/efs_fs_sb.h>
  82
  83 #define EFS_DIRBSIZE_BITS       EFS_BLOCKSIZE_BITS
  84 #define EFS_DIRBSIZE            (1 << EFS_DIRBSIZE_BITS)
  85
  86 struct efs_dentry {
  87         __be32          inode;
  88         unsigned char   namelen;
  89         char            name[3];
  90 };
  91
  92 #define EFS_DENTSIZE    (sizeof(struct efs_dentry) - 3 + 1)
  93 #define EFS_MAXNAMELEN  ((1 << (sizeof(char) * 8)) - 1)
  94
  95 #define EFS_DIRBLK_HEADERSIZE   4
  96 #define EFS_DIRBLK_MAGIC        0xbeef  /* moo */
  97
  98 struct efs_dir {
  99         __be16  magic;
 100         unsigned char   firstused;
 101         unsigned char   slots;
 102
 103         unsigned char   space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE];
 104 };
 105
 106 #define EFS_MAXENTS \
 107         ((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \
 108          (EFS_DENTSIZE + sizeof(char)))
 109
 110 #define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot])
 111
 112 #define EFS_REALOFF(offset) ((offset << 1))
 113
 114
 115 static inline struct efs_inode_info *INODE_INFO(struct inode *inode)
 116 {
 117         return container_of(inode, struct efs_inode_info, vfs_inode);
 118 }
 119
 120 static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb)
 121 {
 122         return sb->s_fs_info;
 123 }
 124
 125 struct statfs;
 126 struct fid;
 127
 128 extern const struct inode_operations efs_dir_inode_operations;
 129 extern const struct file_operations efs_dir_operations;
 130 extern const struct address_space_operations efs_symlink_aops;
 131
 132 extern struct inode *efs_iget(struct super_block *, unsigned long);
 133 extern efs_block_t efs_map_block(struct inode *, efs_block_t);
 134 extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 135
 136 extern struct dentry *efs_lookup(struct inode *, struct dentry *, unsigned int);
 137 extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 138                 int fh_len, int fh_type);
 139 extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
 140                 int fh_len, int fh_type);
 141 extern struct dentry *efs_get_parent(struct dentry *);
 142 extern int efs_bmap(struct inode *, int);
 143
 144 #endif /* _EFS_EFS_H_ */