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/* $OpenBSD: ffs_subr.c,v 1.5 2016/10/16 22:26:34 tedu Exp $ */
/* $NetBSD: ffs_subr.c,v 1.49 2016/05/07 11:59:08 maxv 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/param.h>
/* in ffs_tables.c */
extern const int inside[], around[];
extern const u_char * const fragtbl[];
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/ufs/ufs_bswap.h>
#include <ufs/ufs/dinode.h>
void panic(const char *, ...)
__attribute__((__noreturn__,__format__(__printf__,1,2)));
/*
* 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(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);
}
}
/*
* take a block out of the map
*/
void
ffs_clrblock(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(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);
}
}
/*
* Update the cluster map because of an allocation or free.
*
* Cnt == 1 means free; cnt == -1 means allocating.
*/
void
ffs_clusteracct(struct fs *fs, struct cg *cgp, int32_t blkno, int cnt)
{
int32_t *sump;
int32_t *lp;
u_char *freemapp, *mapp;
int i, start, end, forw, back, map, bit;
/* KASSERT(mutex_owned(&ump->um_lock)); */
if (fs->fs_contigsumsize <= 0)
return;
freemapp = cg_clustersfree(cgp, 0);
sump = cg_clustersum(cgp, 0);
/*
* Allocate or clear the actual block.
*/
if (cnt > 0)
setbit(freemapp, blkno);
else
clrbit(freemapp, blkno);
/*
* Find the size of the cluster going forward.
*/
start = blkno + 1;
end = start + fs->fs_contigsumsize;
if ((uint32_t)end >= ufs_rw32(cgp->cg_nclusterblks, 0))
end = ufs_rw32(cgp->cg_nclusterblks, 0);
mapp = &freemapp[start / NBBY];
map = *mapp++;
bit = 1 << (start % NBBY);
for (i = start; i < end; i++) {
if ((map & bit) == 0)
break;
if ((i & (NBBY - 1)) != (NBBY - 1)) {
bit <<= 1;
} else {
map = *mapp++;
bit = 1;
}
}
forw = i - start;
/*
* Find the size of the cluster going backward.
*/
start = blkno - 1;
end = start - fs->fs_contigsumsize;
if (end < 0)
end = -1;
mapp = &freemapp[start / NBBY];
map = *mapp--;
bit = 1 << (start % NBBY);
for (i = start; i > end; i--) {
if ((map & bit) == 0)
break;
if ((i & (NBBY - 1)) != 0) {
bit >>= 1;
} else {
map = *mapp--;
bit = 1 << (NBBY - 1);
}
}
back = start - i;
/*
* Account for old cluster and the possibly new forward and
* back clusters.
*/
i = back + forw + 1;
if (i > fs->fs_contigsumsize)
i = fs->fs_contigsumsize;
sump[i] += cnt;
if (back > 0)
sump[back] -= cnt;
if (forw > 0)
sump[forw] -= cnt;
/*
* Update cluster summary information.
*/
lp = &sump[fs->fs_contigsumsize];
for (i = fs->fs_contigsumsize; i > 0; i--)
if (ufs_rw32(*lp--, 0) > 0)
break;
}
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