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/* Miscellaneous map manipulation routines
Copyright (C) 1991, 1992, 1994 Free Software Foundation
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
The GNU Hurd is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the GNU Hurd; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Slightly modified from UCB by Michael I. Bushnell. */
/*
* Copyright (c) 1982, 1986, 1989 Regents of the University of California.
* All rights reserved.
*
* Redistribution is only permitted until one year after the first shipment
* of 4.4BSD by the Regents. Otherwise, redistribution and use in source and
* binary forms are permitted provided that: (1) source distributions retain
* this entire copyright notice and comment, and (2) distributions including
* binaries display the following acknowledgement: This product includes
* software developed by the University of California, Berkeley and its
* contributors'' in the documentation or other materials provided with the
* distribution and in all advertising materials mentioning features or use
* of this software. 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 AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* @(#)ufs_subr.c 7.13 (Berkeley) 6/28/90
*/
#include <assert.h>
extern int around[9];
extern int inside[9];
extern u_char *fragtbl[];
/*
* Update the frsum fields to reflect addition or deletion
* of some frags.
*/
void
fragacct(int fragmap,
long fraglist[],
int cnt)
{
int inblk;
int field, subfield;
int siz, pos;
inblk = (int)(fragtbl[sblock->fs_frag][fragmap]) << 1;
fragmap <<= 1;
for (siz = 1; siz < sblock->fs_frag; siz++) {
if ((inblk & (1 << (siz + (sblock->fs_frag % NBBY)))) == 0)
continue;
field = around[siz];
subfield = inside[siz];
for (pos = siz; pos <= sblock->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
*/
int
isblock(u_char *cp,
daddr_t h)
{
u_char mask;
switch ((int)sblock->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:
assert (0);
}
}
/*
* take a block out of the map
*/
void
clrblock(u_char *cp,
daddr_t h)
{
switch ((int)sblock->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:
assert (0);
}
}
/*
* put a block into the map
*/
void
setblock(u_char *cp,
daddr_t h)
{
switch ((int)sblock->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:
assert (0);
}
}
int
skpc(u_char mask,
u_int size,
u_char *cp)
{
u_char *end = &cp[size];
while (cp < end && *cp == mask)
cp++;
return (end - cp);
}
int
scanc(u_int size,
u_char *cp,
u_char table[],
u_char mask)
{
register u_char *end = &cp[size];
while (cp < end && (table[*cp] & mask) == 0)
cp++;
return (end - cp);
}
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