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BSD 4_3_Net_2 release
[unix-history] / usr / src / sys / ufs / ufs_bmap.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_bmap.c 7.13 (Berkeley) 5/8/91
*/
#include "param.h"
#include "systm.h"
#include "buf.h"
#include "proc.h"
#include "file.h"
#include "vnode.h"
#include "quota.h"
#include "inode.h"
#include "fs.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 array of block pointers described by the dinode.
*/
bmap(ip, bn, bnp)
register struct inode *ip;
register daddr_t bn;
daddr_t *bnp;
{
register struct fs *fs;
register daddr_t nb;
struct buf *bp;
daddr_t *bap;
int i, j, sh;
int error;
if (bn < 0)
return (EFBIG);
fs = ip->i_fs;
/*
* The first NDADDR blocks are direct blocks
*/
if (bn < NDADDR) {
nb = ip->i_db[bn];
if (nb == 0) {
*bnp = (daddr_t)-1;
return (0);
}
*bnp = fsbtodb(fs, nb);
return (0);
}
/*
* Determine the number of levels of indirection.
*/
sh = 1;
bn -= NDADDR;
for (j = NIADDR; j > 0; j--) {
sh *= NINDIR(fs);
if (bn < sh)
break;
bn -= sh;
}
if (j == 0)
return (EFBIG);
/*
* Fetch through the indirect blocks.
*/
nb = ip->i_ib[NIADDR - j];
if (nb == 0) {
*bnp = (daddr_t)-1;
return (0);
}
for (; j <= NIADDR; j++) {
if (error = bread(ip->i_devvp, fsbtodb(fs, nb),
(int)fs->fs_bsize, NOCRED, &bp)) {
brelse(bp);
return (error);
}
bap = bp->b_un.b_daddr;
sh /= NINDIR(fs);
i = (bn / sh) % NINDIR(fs);
nb = bap[i];
if (nb == 0) {
*bnp = (daddr_t)-1;
brelse(bp);
return (0);
}
brelse(bp);
}
*bnp = fsbtodb(fs, nb);
return (0);
}
/*
* 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.
*/
balloc(ip, bn, size, bpp, flags)
register struct inode *ip;
register daddr_t bn;
int size;
struct buf **bpp;
int flags;
{
register struct fs *fs;
register daddr_t nb;
struct buf *bp, *nbp;
struct vnode *vp = ITOV(ip);
int osize, nsize, i, j, sh, error;
daddr_t newb, lbn, *bap, pref, blkpref();
*bpp = (struct buf *)0;
if (bn < 0)
return (EFBIG);
fs = ip->i_fs;
/*
* 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.
*/
nb = lblkno(fs, ip->i_size);
if (nb < NDADDR && nb < bn) {
osize = blksize(fs, ip, nb);
if (osize < fs->fs_bsize && osize > 0) {
error = realloccg(ip, nb,
blkpref(ip, nb, (int)nb, &ip->i_db[0]),
osize, (int)fs->fs_bsize, &bp);
if (error)
return (error);
ip->i_size = (nb + 1) * fs->fs_bsize;
vnode_pager_setsize(ITOV(ip), (u_long)ip->i_size);
ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
ip->i_flag |= IUPD|ICHG;
if (flags & B_SYNC)
bwrite(bp);
else
bawrite(bp);
}
}
/*
* The first NDADDR blocks are direct blocks
*/
if (bn < NDADDR) {
nb = ip->i_db[bn];
if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
*bpp = bp;
return (0);
}
if (nb != 0) {
/*
* Consider need to reallocate a fragment.
*/
osize = fragroundup(fs, blkoff(fs, ip->i_size));
nsize = fragroundup(fs, size);
if (nsize <= osize) {
error = bread(vp, bn, osize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
} else {
error = realloccg(ip, bn,
blkpref(ip, bn, (int)bn, &ip->i_db[0]),
osize, nsize, &bp);
if (error)
return (error);
}
} else {
if (ip->i_size < (bn + 1) * fs->fs_bsize)
nsize = fragroundup(fs, size);
else
nsize = fs->fs_bsize;
error = alloc(ip, bn,
blkpref(ip, bn, (int)bn, &ip->i_db[0]),
nsize, &newb);
if (error)
return (error);
bp = getblk(vp, bn, nsize);
bp->b_blkno = fsbtodb(fs, newb);
if (flags & B_CLRBUF)
clrbuf(bp);
}
ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
ip->i_flag |= IUPD|ICHG;
*bpp = bp;
return (0);
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
sh = 1;
lbn = bn;
bn -= NDADDR;
for (j = NIADDR; j > 0; j--) {
sh *= NINDIR(fs);
if (bn < sh)
break;
bn -= sh;
}
if (j == 0)
return (EFBIG);
/*
* Fetch the first indirect block allocating if necessary.
*/
nb = ip->i_ib[NIADDR - j];
if (nb == 0) {
pref = blkpref(ip, lbn, 0, (daddr_t *)0);
if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb))
return (error);
nb = newb;
bp = getblk(ip->i_devvp, fsbtodb(fs, nb), fs->fs_bsize);
clrbuf(bp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if (error = bwrite(bp)) {
blkfree(ip, nb, fs->fs_bsize);
return (error);
}
ip->i_ib[NIADDR - j] = nb;
ip->i_flag |= IUPD|ICHG;
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (; ; j++) {
error = bread(ip->i_devvp, fsbtodb(fs, nb),
(int)fs->fs_bsize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
bap = bp->b_un.b_daddr;
sh /= NINDIR(fs);
i = (bn / sh) % NINDIR(fs);
nb = bap[i];
if (j == NIADDR)
break;
if (nb != 0) {
brelse(bp);
continue;
}
if (pref == 0)
pref = blkpref(ip, lbn, 0, (daddr_t *)0);
if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb)) {
brelse(bp);
return (error);
}
nb = newb;
nbp = getblk(ip->i_devvp, fsbtodb(fs, nb), fs->fs_bsize);
clrbuf(nbp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if (error = bwrite(nbp)) {
blkfree(ip, nb, fs->fs_bsize);
brelse(bp);
return (error);
}
bap[i] = nb;
/*
* If required, write synchronously, otherwise use
* delayed write. If this is the first instance of
* the delayed write, reassociate the buffer with the
* file so it will be written if the file is sync'ed.
*/
if (flags & B_SYNC) {
bwrite(bp);
} else if (bp->b_flags & B_DELWRI) {
bdwrite(bp);
} else {
bdwrite(bp);
reassignbuf(bp, vp);
}
}
/*
* Get the data block, allocating if necessary.
*/
if (nb == 0) {
pref = blkpref(ip, lbn, i, &bap[0]);
if (error = alloc(ip, lbn, pref, (int)fs->fs_bsize, &newb)) {
brelse(bp);
return (error);
}
nb = newb;
nbp = getblk(vp, lbn, fs->fs_bsize);
nbp->b_blkno = fsbtodb(fs, nb);
if (flags & B_CLRBUF)
clrbuf(nbp);
bap[i] = nb;
/*
* If required, write synchronously, otherwise use
* delayed write. If this is the first instance of
* the delayed write, reassociate the buffer with the
* file so it will be written if the file is sync'ed.
*/
if (flags & B_SYNC) {
bwrite(bp);
} else if (bp->b_flags & B_DELWRI) {
bdwrite(bp);
} else {
bdwrite(bp);
reassignbuf(bp, vp);
}
*bpp = nbp;
return (0);
}
brelse(bp);
if (flags & B_CLRBUF) {
error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
if (error) {
brelse(nbp);
return (error);
}
} else {
nbp = getblk(vp, lbn, fs->fs_bsize);
nbp->b_blkno = fsbtodb(fs, nb);
}
*bpp = nbp;
return (0);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.