/*-
* modified for Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*/
/*-
* 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.
* 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.
*
* @(#)ffs_balloc.c 8.4 (Berkeley) 9/23/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/lock.h>
#include <sys/ucred.h>
#include <sys/vnode.h>
#include <gnu/fs/ext2fs/inode.h>
#include <gnu/fs/ext2fs/ext2_fs.h>
#include <gnu/fs/ext2fs/ext2_fs_sb.h>
#include <gnu/fs/ext2fs/fs.h>
#include <gnu/fs/ext2fs/ext2_extern.h>
/*
* 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.
*/
int
ext2_balloc(ip, bn, size, cred, bpp, flags)
struct inode *ip;
int32_t bn;
int size;
struct ucred *cred;
struct buf **bpp;
int flags;
{
struct ext2_sb_info *fs;
int32_t nb;
struct buf *bp, *nbp;
struct vnode *vp = ITOV(ip);
struct indir indirs[NIADDR + 2];
int32_t newb, lbn, *bap, pref;
int osize, nsize, num, i, error;
/*
ext2_debug("ext2_balloc called (%d, %d, %d)\n",
ip->i_number, (int)bn, (int)size);
*/
*bpp = NULL;
if (bn < 0)
return (EFBIG);
fs = ip->i_e2fs;
lbn = bn;
/*
* check if this is a sequential block allocation.
* If so, increment next_alloc fields to allow ext2_blkpref
* to make a good guess
*/
if (lbn == ip->i_next_alloc_block + 1) {
ip->i_next_alloc_block++;
ip->i_next_alloc_goal++;
}
/*
* The first NDADDR blocks are direct blocks
*/
if (bn < NDADDR) {
nb = ip->i_db[bn];
/* no new block is to be allocated, and no need to expand
the file */
if (nb != 0 && ip->i_size >= (bn + 1) * fs->s_blocksize) {
error = bread(vp, bn, fs->s_blocksize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
bp->b_blkno = fsbtodb(fs, nb);
*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);
}
bp->b_blkno = fsbtodb(fs, nb);
} else {
/* Godmar thinks: this shouldn't happen w/o fragments */
printf("nsize %d(%d) > osize %d(%d) nb %d\n",
(int)nsize, (int)size, (int)osize,
(int)ip->i_size, (int)nb);
panic(
"ext2_balloc: Something is terribly wrong");
/*
* please note there haven't been any changes from here on -
* FFS seems to work.
*/
}
} else {
if (ip->i_size < (bn + 1) * fs->s_blocksize)
nsize = fragroundup(fs, size);
else
nsize = fs->s_blocksize;
error = ext2_alloc(ip, bn,
ext2_blkpref(ip, bn, (int)bn, &ip->i_db[0], 0),
nsize, cred, &newb);
if (error)
return (error);
bp = getblk(vp, bn, nsize, 0, 0, 0);
bp->b_blkno = fsbtodb(fs, newb);
if (flags & B_CLRBUF)
vfs_bio_clrbuf(bp);
}
ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
*bpp = bp;
return (0);
}
/*
* Determine the number of levels of indirection.
*/
pref = 0;
if ((error = ext2_getlbns(vp, bn, indirs, &num)) != 0)
return(error);
#ifdef DIAGNOSTIC
if (num < 1)
panic ("ext2_balloc: ext2_getlbns returned indirect block");
#endif
/*
* Fetch the first indirect block allocating if necessary.
*/
--num;
nb = ip->i_ib[indirs[0].in_off];
if (nb == 0) {
#if 0
pref = ext2_blkpref(ip, lbn, 0, (int32_t *)0, 0);
#else
/* see the comment by ext2_blkpref. What we do here is
to pretend that it'd be good for a block holding indirect
pointers to be allocated near its predecessor in terms
of indirection, or the last direct block.
We shamelessly exploit the fact that i_ib immediately
follows i_db.
Godmar thinks it make sense to allocate i_ib[0] immediately
after i_db[11], but it's not utterly clear whether this also
applies to i_ib[1] and i_ib[0]
*/
pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
#endif
if ((error = ext2_alloc(ip, lbn, pref, (int)fs->s_blocksize,
cred, &newb)) != 0)
return (error);
nb = newb;
bp = getblk(vp, indirs[1].in_lbn, fs->s_blocksize, 0, 0, 0);
bp->b_blkno = fsbtodb(fs, newb);
vfs_bio_clrbuf(bp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(bp)) != 0) {
ext2_blkfree(ip, nb, fs->s_blocksize);
return (error);
}
ip->i_ib[indirs[0].in_off] = newb;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* Fetch through the indirect blocks, allocating as necessary.
*/
for (i = 1;;) {
error = bread(vp,
indirs[i].in_lbn, (int)fs->s_blocksize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
bap = (int32_t *)bp->b_data;
nb = bap[indirs[i].in_off];
if (i == num)
break;
i += 1;
if (nb != 0) {
brelse(bp);
continue;
}
if (pref == 0)
#if 1
/* see the comment above and by ext2_blkpref
* I think this implements Linux policy, but
* does it really make sense to allocate to
* block containing pointers together ?
* Also, will it ever succeed ?
*/
pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
bp->b_lblkno);
#else
pref = ext2_blkpref(ip, lbn, 0, (int32_t *)0, 0);
#endif
if ((error =
ext2_alloc(ip, lbn, pref, (int)fs->s_blocksize, cred, &newb)) != 0) {
brelse(bp);
return (error);
}
nb = newb;
nbp = getblk(vp, indirs[i].in_lbn, fs->s_blocksize, 0, 0, 0);
nbp->b_blkno = fsbtodb(fs, nb);
vfs_bio_clrbuf(nbp);
/*
* Write synchronously so that indirect blocks
* never point at garbage.
*/
if ((error = bwrite(nbp)) != 0) {
ext2_blkfree(ip, nb, fs->s_blocksize);
brelse(bp);
return (error);
}
bap[indirs[i - 1].in_off] = nb;
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
bwrite(bp);
} else {
bdwrite(bp);
}
}
/*
* Get the data block, allocating if necessary.
*/
if (nb == 0) {
pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
bp->b_lblkno);
if ((error = ext2_alloc(ip,
lbn, pref, (int)fs->s_blocksize, cred, &newb)) != 0) {
brelse(bp);
return (error);
}
nb = newb;
nbp = getblk(vp, lbn, fs->s_blocksize, 0, 0, 0);
nbp->b_blkno = fsbtodb(fs, nb);
if (flags & B_CLRBUF)
vfs_bio_clrbuf(nbp);
bap[indirs[i].in_off] = nb;
/*
* If required, write synchronously, otherwise use
* delayed write.
*/
if (flags & B_SYNC) {
bwrite(bp);
} else {
bdwrite(bp);
}
*bpp = nbp;
return (0);
}
brelse(bp);
if (flags & B_CLRBUF) {
error = bread(vp, lbn, (int)fs->s_blocksize, NOCRED, &nbp);
if (error) {
brelse(nbp);
return (error);
}
} else {
nbp = getblk(vp, lbn, fs->s_blocksize, 0, 0, 0);
nbp->b_blkno = fsbtodb(fs, nb);
}
*bpp = nbp;
return (0);
}
