NetBSD/sys/filecorefs/filecore_bmap.c

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/* $NetBSD: filecore_bmap.c,v 1.3 1998/10/29 23:18:57 mark Exp $ */
/*-
* Copyright (c) 1998 Andrew McMurry
* Copyright (c) 1994 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. 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.
*
* filecore_bmap.c 1.1 1998/6/26
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <filecorefs/filecore.h>
#include <filecorefs/filecore_extern.h>
#include <filecorefs/filecore_node.h>
/*
* Bmap converts a the logical block number of a file to its physical block
* number on the disk. The conversion is done by using the logical block
* number to index into the data block (extent) for the file.
*/
int
filecore_bmap(v)
void *v;
{
struct vop_bmap_args /* {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
} */ *ap = v;
struct filecore_node *ip = VTOI(ap->a_vp);
struct filecore_mnt *fcmp = ip->i_mnt;
daddr_t lbn = ap->a_bn;
/*
* Check for underlying vnode requests and ensure that logical
* to physical mapping is requested.
*/
if (ap->a_vpp != NULL)
*ap->a_vpp = ip->i_devvp;
if (ap->a_bnp == NULL)
return (0);
/*
* Determine maximum number of readahead blocks following the
* requested block.
*/
if (ap->a_runp) {
int nblk;
int bshift=fcmp->log2bsize;
nblk = (ip->i_size >> bshift) - (lbn + 1);
if (nblk <= 0)
*ap->a_runp = 0;
else if (nblk >= (MAXBSIZE >> bshift))
*ap->a_runp = (MAXBSIZE >> bshift) - 1;
else
*ap->a_runp = nblk;
}
/*
* Compute the requested block number
*/
return filecore_map(fcmp, ip->i_dirent.addr, lbn, ap->a_bnp);
}
int
filecore_map(fcmp, addr, lbn, bnp)
struct filecore_mnt *fcmp;
u_int32_t addr;
daddr_t lbn;
daddr_t *bnp;
{
struct buf *bp;
u_long frag, sect, zone, izone, a, b, m, n;
u_int64_t zaddr;
u_long *ptr;
long c;
int error = 0;
#ifdef FILECORE_DEBUG
printf("filecore_map(addr=%x, lbn=%x)\n", addr, lbn);
#endif
frag = addr >> 8;
sect = (addr & 0xff) +
((lbn << fcmp->log2bsize) >> fcmp->drec.log2secsize);
if (frag != 2)
zone = frag / fcmp->idspz;
else
zone = fcmp->drec.nzones / 2;
izone = zone;
if (zone != 0)
zaddr=((8<<fcmp->drec.log2secsize)-fcmp->drec.zone_spare)*zone
- 8*FILECORE_DISCREC_SIZE;
else
zaddr = 0;
if (sect > 0)
sect--;
sect <<= fcmp->drec.share_size;
do {
error=bread(fcmp->fc_devvp, fcmp->map + zone,
1 << fcmp->drec.log2secsize, NOCRED, &bp);
#ifdef FILECORE_DEBUG_BR
printf("bread(%p, %lx, %d, CRED, %p)=%d\n", fcmp->fc_devvp,
fcmp->map+zone, 1 << fcmp->drec.log2secsize, bp, error);
printf("block is at %p\n", bp->b_data);
#endif
if (error != 0) {
#ifdef FILECORE_DEBUG_BR
printf("brelse(%p) bm1\n", bp);
#endif
brelse(bp);
return error;
}
ptr = (u_long *)(bp->b_data) + 1; /* skip map zone header */
if (zone == 0)
ptr += FILECORE_DISCREC_SIZE >> 2;
b = 0;
while (b < (8 << (fcmp->drec.log2secsize))
- fcmp->drec.zone_spare) {
a = ptr[b >> 5] >> (b & 31);
c = 32 - (b & 31) - fcmp->drec.idlen;
if (c <= 0) {
m = ptr[(b >> 5) + 1];
a |= m << (fcmp->drec.idlen+c);
m >>= -c;
c += 32;
} else
m = a >> fcmp->drec.idlen;
n = fcmp->drec.idlen + 1;
while ((m & 1) == 0) {
m >>= 1;
n++;
if (--c == 0) {
c=32;
m = ptr[(b + n - 1) >> 5];
}
}
a &= fcmp->mask;
if (a == frag) {
if (sect << fcmp->drec.log2secsize < n
<< fcmp->drec.log2bpmb) {
*bnp = (((zaddr+b)
<< fcmp->drec.log2bpmb)
>> fcmp->drec.log2secsize) + sect;
#ifdef FILECORE_DEBUG_BR
printf("brelse(%p) bm2\n", bp);
#endif
brelse(bp);
return 0;
} else
sect -= (n<<fcmp->drec.log2bpmb)
>> fcmp->drec.log2secsize;
}
b += n;
}
#ifdef FILECORE_DEBUG_BR
printf("brelse(%p) bm3\n", bp);
#endif
brelse(bp);
if (++zone == fcmp->drec.nzones) {
zone = 0;
zaddr=0;
} else
zaddr += ((8 << fcmp->drec.log2secsize)
- fcmp->drec.zone_spare);
} while (zone != izone);
return (E2BIG);
}
int
filecore_bread(fcmp, addr, size, cred, bp)
struct filecore_mnt *fcmp;
u_int32_t addr;
int size;
struct ucred *cred;
struct buf **bp;
{
int error = 0;
daddr_t bn;
error = filecore_map(fcmp, addr, 0, &bn);
if (error) {
#ifdef FILECORE_DEBUG
printf("filecore_bread(error=%d)\n", error);
#endif
return error;
}
error = bread(fcmp->fc_devvp, bn, size, cred, bp);
#ifdef FILECORE_DEBUG_BR
printf("bread(%p, %x, %d, CRED, %p)=%d\n", fcmp->fc_devvp, bn, size,
*bp, error);
#endif
return error;
}
int
filecore_dbread(ip, bp)
struct filecore_node *ip;
struct buf **bp;
{
int error = 0;
if (ip->i_block == -1)
error = filecore_map(ip->i_mnt, ip->i_dirent.addr,
0, &(ip->i_block));
if (error)
return error;
error = bread(ip->i_mnt->fc_devvp, ip->i_block, FILECORE_DIR_SIZE,
NOCRED, bp);
#ifdef FILECORE_DEBUG_BR
printf("bread(%p, %x, %d, CRED, %p)=%d\n", ip->i_mnt->fc_devvp,
ip->i_block, FILECORE_DIR_SIZE, *bp, error);
#endif
return error;
}