InfoMagic Source Code 1993 July/THE_SOURCE_CODE_CD_ROM.iso/bsd_srcs/sys/ufs/ufs_subr.c

C/C++ Source or Header | 1991-05-08 | 4.8 KB | 211 lines

/*
 * Copyright (c) 1982, 1986, 1989 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the University of
 *    California, Berkeley and its contributors.
 * 4. 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.
 *
 *    @(#)ufs_subr.c    7.13 (Berkeley) 6/28/90
 */

#ifdef KERNEL
#include "param.h"
#include "../ufs/fs.h"
#else
#include <sys/param.h>
#include <ufs/fs.h>
#endif

extern    int around[9];
extern    int inside[9];
extern    u_char *fragtbl[];

/*
 * Update the frsum fields to reflect addition or deletion
 * of some frags.
 */
fragacct(fs, fragmap, fraglist, cnt)
    struct fs *fs;
    int fragmap;
    long fraglist[];
    int cnt;
{
    int inblk;
    register int field, subfield;
    register 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)))) == 0)
            continue;
        field = around[siz];
        subfield = inside[siz];
        for (pos = siz; pos <= fs->fs_frag; pos++) {
            if ((fragmap & field) == subfield) {
                fraglist[siz] += cnt;
                pos += siz;
                field <<= siz;
                subfield <<= siz;
            }
            field <<= 1;
            subfield <<= 1;
        }
    }
}

/*
 * block operations
 *
 * check if a block is available
 */
isblock(fs, cp, h)
    struct fs *fs;
    unsigned char *cp;
    daddr_t h;
{
    unsigned char mask;

    switch ((int)fs->fs_frag) {
    case 8:
        return (cp[h] == 0xff);
    case 4:
        mask = 0x0f << ((h & 0x1) << 2);
        return ((cp[h >> 1] & mask) == mask);
    case 2:
        mask = 0x03 << ((h & 0x3) << 1);
        return ((cp[h >> 2] & mask) == mask);
    case 1:
        mask = 0x01 << (h & 0x7);
        return ((cp[h >> 3] & mask) == mask);
    default:
        panic("isblock");
        return (NULL);
    }
}

/*
 * take a block out of the map
 */
clrblock(fs, cp, h)
    struct fs *fs;
    u_char *cp;
    daddr_t h;
{

    switch ((int)fs->fs_frag) {
    case 8:
        cp[h] = 0;
        return;
    case 4:
        cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
        return;
    case 2:
        cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
        return;
    case 1:
        cp[h >> 3] &= ~(0x01 << (h & 0x7));
        return;
    default:
        panic("clrblock");
    }
}

/*
 * put a block into the map
 */
setblock(fs, cp, h)
    struct fs *fs;
    unsigned char *cp;
    daddr_t h;
{

    switch ((int)fs->fs_frag) {

    case 8:
        cp[h] = 0xff;
        return;
    case 4:
        cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
        return;
    case 2:
        cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
        return;
    case 1:
        cp[h >> 3] |= (0x01 << (h & 0x7));
        return;
    default:
        panic("setblock");
    }
}

#if (!defined(vax) && !defined(tahoe) && !defined(hp300)) \
    || defined(VAX630) || defined(VAX650)
/*
 * C definitions of special instructions.
 * Normally expanded with inline.
 */
scanc(size, cp, table, mask)
    u_int size;
    register u_char *cp, table[];
    register u_char mask;
{
    register u_char *end = &cp[size];

    while (cp < end && (table[*cp] & mask) == 0)
        cp++;
    return (end - cp);
}
#endif

#if !defined(vax) && !defined(tahoe) && !defined(hp300)
skpc(mask, size, cp)
    register u_char mask;
    u_int size;
    register u_char *cp;
{
    register u_char *end = &cp[size];

    while (cp < end && *cp == mask)
        cp++;
    return (end - cp);
}

locc(mask, size, cp)
    register u_char mask;
    u_int size;
    register u_char *cp;
{
    register u_char *end = &cp[size];

    while (cp < end && *cp != mask)
        cp++;
    return (end - cp);
}
#endif