Annotation of sys/ufs/ufs/dir.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: dir.h,v 1.10 2005/06/18 18:09:43 millert Exp $ */
! 2: /* $NetBSD: dir.h,v 1.8 1996/03/09 19:42:41 scottr Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1982, 1986, 1989, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: * (c) UNIX System Laboratories, Inc.
! 8: * All or some portions of this file are derived from material licensed
! 9: * to the University of California by American Telephone and Telegraph
! 10: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
! 11: * the permission of UNIX System Laboratories, Inc.
! 12: *
! 13: * Redistribution and use in source and binary forms, with or without
! 14: * modification, are permitted provided that the following conditions
! 15: * are met:
! 16: * 1. Redistributions of source code must retain the above copyright
! 17: * notice, this list of conditions and the following disclaimer.
! 18: * 2. Redistributions in binary form must reproduce the above copyright
! 19: * notice, this list of conditions and the following disclaimer in the
! 20: * documentation and/or other materials provided with the distribution.
! 21: * 3. Neither the name of the University nor the names of its contributors
! 22: * may be used to endorse or promote products derived from this software
! 23: * without specific prior written permission.
! 24: *
! 25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 35: * SUCH DAMAGE.
! 36: *
! 37: * @(#)dir.h 8.4 (Berkeley) 8/10/94
! 38: */
! 39:
! 40: #ifndef _DIR_H_
! 41: #define _DIR_H_
! 42:
! 43: /*
! 44: * Theoretically, directories can be more than 2Gb in length, however, in
! 45: * practice this seems unlikely. So, we define the type doff_t as a 32-bit
! 46: * quantity to keep down the cost of doing lookup on a 32-bit machine.
! 47: */
! 48: #define doff_t int32_t
! 49: #define MAXDIRSIZE (0x7fffffff)
! 50:
! 51: /*
! 52: * A directory consists of some number of blocks of DIRBLKSIZ
! 53: * bytes, where DIRBLKSIZ is chosen such that it can be transferred
! 54: * to disk in a single atomic operation (e.g. 512 bytes on most machines).
! 55: *
! 56: * Each DIRBLKSIZ byte block contains some number of directory entry
! 57: * structures, which are of variable length. Each directory entry has
! 58: * a struct direct at the front of it, containing its inode number,
! 59: * the length of the entry, and the length of the name contained in
! 60: * the entry. These are followed by the name padded to a 4 byte boundary
! 61: * with null bytes. All names are guaranteed null terminated.
! 62: * The maximum length of a name in a directory is MAXNAMLEN.
! 63: *
! 64: * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent
! 65: * a directory entry. Free space in a directory is represented by
! 66: * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes
! 67: * in a directory block are claimed by the directory entries. This
! 68: * usually results in the last entry in a directory having a large
! 69: * dp->d_reclen. When entries are deleted from a directory, the
! 70: * space is returned to the previous entry in the same directory
! 71: * block by increasing its dp->d_reclen. If the first entry of
! 72: * a directory block is free, then its dp->d_ino is set to 0.
! 73: * Entries other than the first in a directory do not normally have
! 74: * dp->d_ino set to 0.
! 75: */
! 76: #define DIRBLKSIZ DEV_BSIZE
! 77: #define MAXNAMLEN 255
! 78:
! 79: struct direct {
! 80: u_int32_t d_ino; /* inode number of entry */
! 81: u_int16_t d_reclen; /* length of this record */
! 82: u_int8_t d_type; /* file type, see below */
! 83: u_int8_t d_namlen; /* length of string in d_name */
! 84: char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */
! 85: };
! 86:
! 87: /*
! 88: * File types
! 89: */
! 90: #define DT_UNKNOWN 0
! 91: #define DT_FIFO 1
! 92: #define DT_CHR 2
! 93: #define DT_DIR 4
! 94: #define DT_BLK 6
! 95: #define DT_REG 8
! 96: #define DT_LNK 10
! 97: #define DT_SOCK 12
! 98:
! 99: /*
! 100: * Convert between stat structure types and directory types.
! 101: */
! 102: #define IFTODT(mode) (((mode) & 0170000) >> 12)
! 103: #define DTTOIF(dirtype) ((dirtype) << 12)
! 104:
! 105: /*
! 106: * The DIRSIZ macro gives the minimum record length which will hold
! 107: * the directory entry. This requires the amount of space in struct direct
! 108: * without the d_name field, plus enough space for the name with a terminating
! 109: * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
! 110: */
! 111: #define DIRECTSIZ(namlen) \
! 112: (((int)&((struct direct *)0)->d_name + \
! 113: ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3)
! 114: #if (BYTE_ORDER == LITTLE_ENDIAN)
! 115: #define DIRSIZ(oldfmt, dp) \
! 116: ((oldfmt) ? \
! 117: ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_type+1 + 3) &~ 3)) : \
! 118: ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)))
! 119: #else
! 120: #define DIRSIZ(oldfmt, dp) \
! 121: ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
! 122: #endif
! 123: #define OLDDIRFMT 1
! 124: #define NEWDIRFMT 0
! 125:
! 126: /*
! 127: * Template for manipulating directories. Should use struct direct's,
! 128: * but the name field is MAXNAMLEN - 1, and this just won't do.
! 129: */
! 130: struct dirtemplate {
! 131: u_int32_t dot_ino;
! 132: int16_t dot_reclen;
! 133: u_int8_t dot_type;
! 134: u_int8_t dot_namlen;
! 135: char dot_name[4]; /* must be multiple of 4 */
! 136: u_int32_t dotdot_ino;
! 137: int16_t dotdot_reclen;
! 138: u_int8_t dotdot_type;
! 139: u_int8_t dotdot_namlen;
! 140: char dotdot_name[4]; /* ditto */
! 141: };
! 142:
! 143: /*
! 144: * This is the old format of directories, sanz type element.
! 145: */
! 146: struct odirtemplate {
! 147: u_int32_t dot_ino;
! 148: int16_t dot_reclen;
! 149: u_int16_t dot_namlen;
! 150: char dot_name[4]; /* must be multiple of 4 */
! 151: u_int32_t dotdot_ino;
! 152: int16_t dotdot_reclen;
! 153: u_int16_t dotdot_namlen;
! 154: char dotdot_name[4]; /* ditto */
! 155: };
! 156: #endif /* !_DIR_H_ */
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