Source to ufs/ufs_subr.c
/*
* 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