141 lines
4.9 KiB
C
141 lines
4.9 KiB
C
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/*
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* Mach Operating System
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* Copyright (c) 1991,1990 Carnegie Mellon University
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* All Rights Reserved.
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
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* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie Mellon
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* the rights to redistribute these changes.
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*/
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/*
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* Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* @(#)dir.h 7.6 (Berkeley) 5/9/89
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*/
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#ifndef _BOOT_UFS_DIR_H_
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#define _BOOT_UFS_DIR_H_
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/*
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* A directory consists of some number of blocks of DIRBLKSIZ
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* bytes, where DIRBLKSIZ is chosen such that it can be transferred
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* to disk in a single atomic operation (e.g. 512 bytes on most machines).
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*
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* Each DIRBLKSIZ byte block contains some number of directory entry
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* structures, which are of variable length. Each directory entry has
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* a struct direct at the front of it, containing its inode number,
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* the length of the entry, and the length of the name contained in
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* the entry. These are followed by the name padded to a 4 byte boundary
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* with null bytes. All names are guaranteed null terminated.
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* The maximum length of a name in a directory is MAXNAMLEN.
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*
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* The macro DIRSIZ(dp) gives the amount of space required to represent
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* a directory entry. Free space in a directory is represented by
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* entries which have dp->d_reclen > DIRSIZ(dp). All DIRBLKSIZ bytes
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* in a directory block are claimed by the directory entries. This
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* usually results in the last entry in a directory having a large
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* dp->d_reclen. When entries are deleted from a directory, the
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* space is returned to the previous entry in the same directory
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* block by increasing its dp->d_reclen. If the first entry of
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* a directory block is free, then its dp->d_ino is set to 0.
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* Entries other than the first in a directory do not normally have
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* dp->d_ino set to 0.
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*/
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#define DIRBLKSIZ DEV_BSIZE
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#define MAXNAMLEN 255
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struct direct
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{
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unsigned int d_ino; /* inode number of entry */
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unsigned short d_reclen; /* length of this record */
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unsigned short d_namlen; /* length of string in d_name */
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char d_name[MAXNAMLEN + 1]; /* name with length <= MAXNAMLEN */
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};
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/*
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* The DIRSIZ macro gives the minimum record length which will hold
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* the directory entry. This requires the amount of space in struct direct
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* without the d_name field, plus enough space for the name with a terminating
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* null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
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*/
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#undef DIRSIZ
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#define DIRSIZ(dp) \
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((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
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#ifdef KERNEL
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/*
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* Template for manipulating directories.
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* Should use struct direct's, but the name field
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* is MAXNAMLEN - 1, and this just won't do.
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*/
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struct dirtemplate
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{
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unsigned int dot_ino;
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short dot_reclen;
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short dot_namlen;
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char dot_name[4]; /* must be multiple of 4 */
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unsigned int dotdot_ino;
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short dotdot_reclen;
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short dotdot_namlen;
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char dotdot_name[4]; /* ditto */
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};
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#endif
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/*
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* The following information should be obtained from <dirent.h>
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* and is provided solely (and temporarily) for backward compatibility.
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*/
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#ifndef KERNEL
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#define d_fileno d_ino /* compatibility with POSIX */
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#ifndef DEV_BSIZE
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#define DEV_BSIZE 512
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#endif
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/*
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* Definitions for library routines operating on directories.
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*/
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typedef struct _dirdesc
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{
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int dd_fd;
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int dd_loc;
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int dd_size;
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char dd_buf[DIRBLKSIZ];
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}
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DIR;
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#define dirfd(dirp) ((dirp)->dd_fd)
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#ifndef NULL
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#define NULL 0
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#endif
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#endif /* not KERNEL */
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#endif /* _BOOT_UFS_DIR_H_ */
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