freebsd-skq/ffs/ffs_balloc.c
2008-11-23 19:59:42 +00:00

585 lines
14 KiB
C

/* $NetBSD: ffs_balloc.c,v 1.13 2004/06/20 22:20:18 jmc Exp $ */
/* From NetBSD: ffs_balloc.c,v 1.25 2001/08/08 08:36:36 lukem 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_balloc.c 8.8 (Berkeley) 6/16/95
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(__lint)
__RCSID("$NetBSD: ffs_balloc.c,v 1.13 2004/06/20 22:20:18 jmc Exp $");
#endif /* !__lint */
#include <sys/param.h>
#include <sys/time.h>
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "makefs.h"
#include <ufs/ufs/dinode.h>
#include <ufs/ufs/ufs_bswap.h>
#include <ufs/ffs/fs.h>
#include "ffs/buf.h"
#include "ffs/ufs_inode.h"
#include "ffs/ffs_extern.h"
static int ffs_balloc_ufs1(struct inode *, off_t, int, struct buf **);
static int ffs_balloc_ufs2(struct inode *, off_t, int, struct buf **);
/*
* Balloc defines the structure of file system storage
* by allocating the physical blocks on a device given
* the inode and the logical block number in a file.
*
* Assume: flags == B_SYNC | B_CLRBUF
*/
int
ffs_balloc(struct inode *ip, off_t offset, int bufsize, struct buf **bpp)
{
if (ip->i_fs->fs_magic == FS_UFS2_MAGIC)
return ffs_balloc_ufs2(ip, offset, bufsize, bpp);
else
return ffs_balloc_ufs1(ip, offset, bufsize, bpp);
}
static int
ffs_balloc_ufs1(struct inode *ip, off_t offset, int bufsize, struct buf **bpp)
{
daddr_t lbn, lastlbn;
int size;
int32_t nb;
struct buf *bp, *nbp;
struct fs *fs = ip->i_fs;
struct indir indirs[NIADDR + 2];
daddr_t newb, pref;
int32_t *bap;
int osize, nsize, num, i, error;
int32_t *allocblk, allociblk[NIADDR + 1];
int32_t *allocib;
const int needswap = UFS_FSNEEDSWAP(fs);
lbn = lblkno(fs, offset);
size = blkoff(fs, offset) + bufsize;
if (bpp != NULL) {
*bpp = NULL;
}
assert(size <= fs->fs_bsize);
if (lbn < 0)
return (EFBIG);
/*
* If the next write will extend the file into a new block,
* and the file is currently composed of a fragment
* this fragment has to be extended to be a full block.
*/
lastlbn = lblkno(fs, ip->i_ffs1_size);
if (lastlbn < NDADDR && lastlbn < lbn) {
nb = lastlbn;
osize = blksize(fs, ip, nb);
if (osize < fs->fs_bsize && osize > 0) {
warnx("need to ffs_realloccg; not supported!");
abort();
}
}
/*
* The first NDADDR blocks are direct blocks
*/
if (lbn < NDADDR) {
nb = ufs_rw32(ip->i_ffs1_db[lbn], needswap);
if (nb != 0 && ip->i_ffs1_size >= lblktosize(fs, lbn + 1)) {
/*
* The block is an already-allocated direct block
* and the file already extends past this block,
* thus this must be a whole block.
* Just read the block (if requested).
*/
if (bpp != NULL) {
error = bread(ip->i_fd, ip->i_fs, lbn,
fs->fs_bsize, bpp);
if (error) {
brelse(*bpp);
return (error);
}
}
return (0);
}
if (nb != 0) {
/*
* Consider need to reallocate a fragment.
*/
osize = fragroundup(fs, blkoff(fs, ip->i_ffs1_size));
nsize = fragroundup(fs, size);
if (nsize <= osize) {
/*
* The existing block is already
* at least as big as we want.
* Just read the block (if requested).
*/
if (bpp != NULL) {
error = bread(ip->i_fd, ip->i_fs, lbn,
osize, bpp);
if (error) {
brelse(*bpp);
return (error);
}
}
return 0;
} else {
warnx("need to ffs_realloccg; not supported!");
abort();
}
} else {
/*
* the block was not previously allocated,
* allocate a new block or fragment.
*/
if (ip->i_ffs1_size < lblktosize(fs, lbn + 1))
nsize = fragroundup(fs, size);
else
nsize = fs->fs_bsize;
error = ffs_alloc(ip, lbn,
ffs_blkpref_ufs1(ip, lbn, (int)lbn,
&ip->i_ffs1_db[0]),
nsize, &newb);
if (error)
return (error);
if (bpp != NULL) {
bp = getblk(ip->i_fd, ip->i_fs, lbn, nsize);
bp->b_blkno = fsbtodb(fs, newb);
clrbuf(bp);
*bpp = bp;
}
}
ip->i_ffs1_db[lbn] = ufs_rw32((int32_t)newb, needswap);
return (0);
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0)
return (error);
if (num < 1) {
warnx("ffs_balloc: ufs_getlbns returned indirect block");
abort();
}
/*
* Fetch the first indirect block allocating if necessary.
*/
--num;
nb = ufs_rw32(ip->i_ffs1_ib[indirs[0].in_off], needswap);
allocib = NULL;
allocblk = allociblk;
if (nb == 0) {
pref = ffs_blkpref_ufs1(ip, lbn, 0, (int32_t *)0);
error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
if (error)
return error;
nb = newb;
*allocblk++ = nb;
bp = getblk(ip->i_fd, ip->i_fs, indirs[1].in_lbn, fs->fs_bsize);
bp->b_blkno = fsbtodb(fs, nb);
clrbuf(bp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(bp)) != 0)
return error;
allocib = &ip->i_ffs1_ib[indirs[0].in_off];
*allocib = ufs_rw32((int32_t)nb, needswap);
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (i = 1;;) {
error = bread(ip->i_fd, ip->i_fs, indirs[i].in_lbn,
fs->fs_bsize, &bp);
if (error) {
brelse(bp);
return error;
}
bap = (int32_t *)bp->b_data;
nb = ufs_rw32(bap[indirs[i].in_off], needswap);
if (i == num)
break;
i++;
if (nb != 0) {
brelse(bp);
continue;
}
if (pref == 0)
pref = ffs_blkpref_ufs1(ip, lbn, 0, (int32_t *)0);
error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
if (error) {
brelse(bp);
return error;
}
nb = newb;
*allocblk++ = nb;
nbp = getblk(ip->i_fd, ip->i_fs, indirs[i].in_lbn,
fs->fs_bsize);
nbp->b_blkno = fsbtodb(fs, nb);
clrbuf(nbp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(nbp)) != 0) {
brelse(bp);
return error;
}
bap[indirs[i - 1].in_off] = ufs_rw32(nb, needswap);
bwrite(bp);
}
/*
* Get the data block, allocating if necessary.
*/
if (nb == 0) {
pref = ffs_blkpref_ufs1(ip, lbn, indirs[num].in_off, &bap[0]);
error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
if (error) {
brelse(bp);
return error;
}
nb = newb;
*allocblk++ = nb;
if (bpp != NULL) {
nbp = getblk(ip->i_fd, ip->i_fs, lbn, fs->fs_bsize);
nbp->b_blkno = fsbtodb(fs, nb);
clrbuf(nbp);
*bpp = nbp;
}
bap[indirs[num].in_off] = ufs_rw32(nb, needswap);
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
bwrite(bp);
return (0);
}
brelse(bp);
if (bpp != NULL) {
error = bread(ip->i_fd, ip->i_fs, lbn, (int)fs->fs_bsize, &nbp);
if (error) {
brelse(nbp);
return error;
}
*bpp = nbp;
}
return (0);
}
static int
ffs_balloc_ufs2(struct inode *ip, off_t offset, int bufsize, struct buf **bpp)
{
daddr_t lbn, lastlbn;
int size;
struct buf *bp, *nbp;
struct fs *fs = ip->i_fs;
struct indir indirs[NIADDR + 2];
daddr_t newb, pref, nb;
int64_t *bap;
int osize, nsize, num, i, error;
int64_t *allocblk, allociblk[NIADDR + 1];
int64_t *allocib;
const int needswap = UFS_FSNEEDSWAP(fs);
lbn = lblkno(fs, offset);
size = blkoff(fs, offset) + bufsize;
if (bpp != NULL) {
*bpp = NULL;
}
assert(size <= fs->fs_bsize);
if (lbn < 0)
return (EFBIG);
/*
* If the next write will extend the file into a new block,
* and the file is currently composed of a fragment
* this fragment has to be extended to be a full block.
*/
lastlbn = lblkno(fs, ip->i_ffs2_size);
if (lastlbn < NDADDR && lastlbn < lbn) {
nb = lastlbn;
osize = blksize(fs, ip, nb);
if (osize < fs->fs_bsize && osize > 0) {
warnx("need to ffs_realloccg; not supported!");
abort();
}
}
/*
* The first NDADDR blocks are direct blocks
*/
if (lbn < NDADDR) {
nb = ufs_rw64(ip->i_ffs2_db[lbn], needswap);
if (nb != 0 && ip->i_ffs2_size >= lblktosize(fs, lbn + 1)) {
/*
* The block is an already-allocated direct block
* and the file already extends past this block,
* thus this must be a whole block.
* Just read the block (if requested).
*/
if (bpp != NULL) {
error = bread(ip->i_fd, ip->i_fs, lbn,
fs->fs_bsize, bpp);
if (error) {
brelse(*bpp);
return (error);
}
}
return (0);
}
if (nb != 0) {
/*
* Consider need to reallocate a fragment.
*/
osize = fragroundup(fs, blkoff(fs, ip->i_ffs2_size));
nsize = fragroundup(fs, size);
if (nsize <= osize) {
/*
* The existing block is already
* at least as big as we want.
* Just read the block (if requested).
*/
if (bpp != NULL) {
error = bread(ip->i_fd, ip->i_fs, lbn,
osize, bpp);
if (error) {
brelse(*bpp);
return (error);
}
}
return 0;
} else {
warnx("need to ffs_realloccg; not supported!");
abort();
}
} else {
/*
* the block was not previously allocated,
* allocate a new block or fragment.
*/
if (ip->i_ffs2_size < lblktosize(fs, lbn + 1))
nsize = fragroundup(fs, size);
else
nsize = fs->fs_bsize;
error = ffs_alloc(ip, lbn,
ffs_blkpref_ufs2(ip, lbn, (int)lbn,
&ip->i_ffs2_db[0]),
nsize, &newb);
if (error)
return (error);
if (bpp != NULL) {
bp = getblk(ip->i_fd, ip->i_fs, lbn, nsize);
bp->b_blkno = fsbtodb(fs, newb);
clrbuf(bp);
*bpp = bp;
}
}
ip->i_ffs2_db[lbn] = ufs_rw64(newb, needswap);
return (0);
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
if ((error = ufs_getlbns(ip, lbn, indirs, &num)) != 0)
return (error);
if (num < 1) {
warnx("ffs_balloc: ufs_getlbns returned indirect block");
abort();
}
/*
* Fetch the first indirect block allocating if necessary.
*/
--num;
nb = ufs_rw64(ip->i_ffs2_ib[indirs[0].in_off], needswap);
allocib = NULL;
allocblk = allociblk;
if (nb == 0) {
pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0);
error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
if (error)
return error;
nb = newb;
*allocblk++ = nb;
bp = getblk(ip->i_fd, ip->i_fs, indirs[1].in_lbn, fs->fs_bsize);
bp->b_blkno = fsbtodb(fs, nb);
clrbuf(bp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(bp)) != 0)
return error;
allocib = &ip->i_ffs2_ib[indirs[0].in_off];
*allocib = ufs_rw64(nb, needswap);
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (i = 1;;) {
error = bread(ip->i_fd, ip->i_fs, indirs[i].in_lbn,
fs->fs_bsize, &bp);
if (error) {
brelse(bp);
return error;
}
bap = (int64_t *)bp->b_data;
nb = ufs_rw64(bap[indirs[i].in_off], needswap);
if (i == num)
break;
i++;
if (nb != 0) {
brelse(bp);
continue;
}
if (pref == 0)
pref = ffs_blkpref_ufs2(ip, lbn, 0, (int64_t *)0);
error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
if (error) {
brelse(bp);
return error;
}
nb = newb;
*allocblk++ = nb;
nbp = getblk(ip->i_fd, ip->i_fs, indirs[i].in_lbn,
fs->fs_bsize);
nbp->b_blkno = fsbtodb(fs, nb);
clrbuf(nbp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(nbp)) != 0) {
brelse(bp);
return error;
}
bap[indirs[i - 1].in_off] = ufs_rw64(nb, needswap);
bwrite(bp);
}
/*
* Get the data block, allocating if necessary.
*/
if (nb == 0) {
pref = ffs_blkpref_ufs2(ip, lbn, indirs[num].in_off, &bap[0]);
error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb);
if (error) {
brelse(bp);
return error;
}
nb = newb;
*allocblk++ = nb;
if (bpp != NULL) {
nbp = getblk(ip->i_fd, ip->i_fs, lbn, fs->fs_bsize);
nbp->b_blkno = fsbtodb(fs, nb);
clrbuf(nbp);
*bpp = nbp;
}
bap[indirs[num].in_off] = ufs_rw64(nb, needswap);
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
bwrite(bp);
return (0);
}
brelse(bp);
if (bpp != NULL) {
error = bread(ip->i_fd, ip->i_fs, lbn, (int)fs->fs_bsize, &nbp);
if (error) {
brelse(nbp);
return error;
}
*bpp = nbp;
}
return (0);
}