xref: /freebsd/usr.sbin/makefs/ffs/ffs_subr.c (revision 55a1bde99c06db049fced70693ff92d9c6a8ac87)

/*	$NetBSD: ffs_subr.c,v 1.32 2003/12/30 12:33:24 pk Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ffs_subr.c	8.5 (Berkeley) 3/21/95
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>

#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include "ffs/ffs_extern.h"
#include "ffs/ufs_bswap.h"

/*
 * Update the frsum fields to reflect addition or deletion
 * of some frags.
 */
void
ffs_fragacct_swap(struct fs *fs, int fragmap, int32_t fraglist[], int cnt, int needswap)
{
	int inblk;
	int field, subfield;
	int siz, pos;

	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
	fragmap <<= 1;
	for (siz = 1; siz < fs->fs_frag; siz++) {
		if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0)
			continue;
		field = around[siz];
		subfield = inside[siz];
		for (pos = siz; pos <= fs->fs_frag; pos++) {
			if ((fragmap & field) == subfield) {
				fraglist[siz] = ufs_rw32(
				    ufs_rw32(fraglist[siz], needswap) + cnt,
				    needswap);
				pos += siz;
				field <<= siz;
				subfield <<= siz;
			}
			field <<= 1;
			subfield <<= 1;
		}
	}
}

/*
 * block operations
 *
 * check if a block is available
 *  returns true if all the correponding bits in the free map are 1
 *  returns false if any corresponding bit in the free map is 0
 */
int
ffs_isblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	int32_t h;
{
	u_char mask;

	switch ((int)fs->fs_fragshift) {
	case 3:
		return (cp[h] == 0xff);
	case 2:
		mask = 0x0f << ((h & 0x1) << 2);
		return ((cp[h >> 1] & mask) == mask);
	case 1:
		mask = 0x03 << ((h & 0x3) << 1);
		return ((cp[h >> 2] & mask) == mask);
	case 0:
		mask = 0x01 << (h & 0x7);
		return ((cp[h >> 3] & mask) == mask);
	default:
		panic("ffs_isblock: unknown fs_fragshift %d",
		    (int)fs->fs_fragshift);
	}
}

/*
 * check if a block is completely allocated
 *  returns true if all the corresponding bits in the free map are 0
 *  returns false if any corresponding bit in the free map is 1
 */
int
ffs_isfreeblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	int32_t h;
{

	switch ((int)fs->fs_fragshift) {
	case 3:
		return (cp[h] == 0);
	case 2:
		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
	case 1:
		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
	case 0:
		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
	default:
		panic("ffs_isfreeblock: unknown fs_fragshift %d",
		    (int)fs->fs_fragshift);
	}
}

/*
 * take a block out of the map
 */
void
ffs_clrblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	int32_t h;
{

	switch ((int)fs->fs_fragshift) {
	case 3:
		cp[h] = 0;
		return;
	case 2:
		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
		return;
	case 1:
		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
		return;
	case 0:
		cp[h >> 3] &= ~(0x01 << (h & 0x7));
		return;
	default:
		panic("ffs_clrblock: unknown fs_fragshift %d",
		    (int)fs->fs_fragshift);
	}
}

/*
 * put a block into the map
 */
void
ffs_setblock(fs, cp, h)
	struct fs *fs;
	u_char *cp;
	int32_t h;
{

	switch ((int)fs->fs_fragshift) {
	case 3:
		cp[h] = 0xff;
		return;
	case 2:
		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
		return;
	case 1:
		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
		return;
	case 0:
		cp[h >> 3] |= (0x01 << (h & 0x7));
		return;
	default:
		panic("ffs_setblock: unknown fs_fragshift %d",
		    (int)fs->fs_fragshift);
	}
}