fs/efs/efs.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * Copyright (c) 1999 Al Smith
0004  *
0005  * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
0006  * Portions derived from IRIX header files (c) 1988 Silicon Graphics
0007  */
0008 #ifndef _EFS_EFS_H_
0009 #define _EFS_EFS_H_
0010
0011 #ifdef pr_fmt
0012 #undef pr_fmt
0013 #endif
0014
0015 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0016
0017 #include <linux/fs.h>
0018 #include <linux/uaccess.h>
0019
0020 #define EFS_VERSION "1.0a"
0021
0022 static const char cprt[] = "EFS: "EFS_VERSION" - (c) 1999 Al Smith <Al.Smith@aeschi.ch.eu.org>";
0023
0024
0025 /* 1 block is 512 bytes */
0026 #define EFS_BLOCKSIZE_BITS  9
0027 #define EFS_BLOCKSIZE       (1 << EFS_BLOCKSIZE_BITS)
0028
0029 typedef int32_t     efs_block_t;
0030 typedef uint32_t    efs_ino_t;
0031
0032 #define EFS_DIRECTEXTENTS   12
0033
0034 /*
0035  * layout of an extent, in memory and on disk. 8 bytes exactly.
0036  */
0037 typedef union extent_u {
0038     unsigned char raw[8];
0039     struct extent_s {
0040         unsigned int    ex_magic:8; /* magic # (zero) */
0041         unsigned int    ex_bn:24;   /* basic block */
0042         unsigned int    ex_length:8;    /* numblocks in this extent */
0043         unsigned int    ex_offset:24;   /* logical offset into file */
0044     } cooked;
0045 } efs_extent;
0046
0047 typedef struct edevs {
0048     __be16      odev;
0049     __be32      ndev;
0050 } efs_devs;
0051
0052 /*
0053  * extent based filesystem inode as it appears on disk.  The efs inode
0054  * is exactly 128 bytes long.
0055  */
0056 struct  efs_dinode {
0057     __be16      di_mode;    /* mode and type of file */
0058     __be16      di_nlink;   /* number of links to file */
0059     __be16      di_uid;     /* owner's user id */
0060     __be16      di_gid;     /* owner's group id */
0061     __be32      di_size;    /* number of bytes in file */
0062     __be32      di_atime;   /* time last accessed */
0063     __be32      di_mtime;   /* time last modified */
0064     __be32      di_ctime;   /* time created */
0065     __be32      di_gen;     /* generation number */
0066     __be16      di_numextents;  /* # of extents */
0067     u_char      di_version; /* version of inode */
0068     u_char      di_spare;   /* spare - used by AFS */
0069     union di_addr {
0070         efs_extent  di_extents[EFS_DIRECTEXTENTS];
0071         efs_devs    di_dev; /* device for IFCHR/IFBLK */
0072     } di_u;
0073 };
0074
0075 /* efs inode storage in memory */
0076 struct efs_inode_info {
0077     int     numextents;
0078     int     lastextent;
0079
0080     efs_extent  extents[EFS_DIRECTEXTENTS];
0081     struct inode    vfs_inode;
0082 };
0083
0084 #include <linux/efs_fs_sb.h>
0085
0086 #define EFS_DIRBSIZE_BITS   EFS_BLOCKSIZE_BITS
0087 #define EFS_DIRBSIZE        (1 << EFS_DIRBSIZE_BITS)
0088
0089 struct efs_dentry {
0090     __be32      inode;
0091     unsigned char   namelen;
0092     char        name[3];
0093 };
0094
0095 #define EFS_DENTSIZE    (sizeof(struct efs_dentry) - 3 + 1)
0096 #define EFS_MAXNAMELEN  ((1 << (sizeof(char) * 8)) - 1)
0097
0098 #define EFS_DIRBLK_HEADERSIZE   4
0099 #define EFS_DIRBLK_MAGIC    0xbeef  /* moo */
0100
0101 struct efs_dir {
0102     __be16  magic;
0103     unsigned char   firstused;
0104     unsigned char   slots;
0105
0106     unsigned char   space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE];
0107 };
0108
0109 #define EFS_MAXENTS \
0110     ((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \
0111      (EFS_DENTSIZE + sizeof(char)))
0112
0113 #define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot])
0114
0115 #define EFS_REALOFF(offset) ((offset << 1))
0116
0117
0118 static inline struct efs_inode_info *INODE_INFO(struct inode *inode)
0119 {
0120     return container_of(inode, struct efs_inode_info, vfs_inode);
0121 }
0122
0123 static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb)
0124 {
0125     return sb->s_fs_info;
0126 }
0127
0128 struct statfs;
0129 struct fid;
0130
0131 extern const struct inode_operations efs_dir_inode_operations;
0132 extern const struct file_operations efs_dir_operations;
0133 extern const struct address_space_operations efs_symlink_aops;
0134
0135 extern struct inode *efs_iget(struct super_block *, unsigned long);
0136 extern efs_block_t efs_map_block(struct inode *, efs_block_t);
0137 extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);
0138
0139 extern struct dentry *efs_lookup(struct inode *, struct dentry *, unsigned int);
0140 extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
0141         int fh_len, int fh_type);
0142 extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
0143         int fh_len, int fh_type);
0144 extern struct dentry *efs_get_parent(struct dentry *);
0145 extern int efs_bmap(struct inode *, int);
0146
0147 #endif /* _EFS_EFS_H_ */