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NetBSD/sys/ufs/ext2fs/ext2fs_bmap.c

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/* $NetBSD: ext2fs_bmap.c,v 1.27 2016/06/03 15:35:48 christos Exp $ */
/*
* Copyright (c) 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
*
* @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94
* Modified for ext2fs by Manuel Bouyer.
*/
/*
* Copyright (c) 1997 Manuel Bouyer.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 8.6 (Berkeley) 1/21/94
* Modified for ext2fs by Manuel Bouyer.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ext2fs_bmap.c,v 1.27 2016/06/03 15:35:48 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/resourcevar.h>
#include <sys/trace.h>
#include <miscfs/specfs/specdev.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ext2fs/ext2fs.h>
#include <ufs/ext2fs/ext2fs_extern.h>
static int ext4_bmapext(struct vnode *, int32_t, int64_t *, int *, int *);
static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, struct indir *,
int *, int *);
#define is_sequential(ump, a, b) ((b) == (a) + ump->um_seqinc)
/*
* 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.
*/
int
ext2fs_bmap(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;
/*
* Check for underlying vnode requests and ensure that logical
* to physical mapping is requested.
*/
if (ap->a_vpp != NULL)
*ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
if (ap->a_bnp == NULL)
return (0);
if (VTOI(ap->a_vp)->i_din.e2fs_din->e2di_flags & IN_E4EXTENTS)
return ext4_bmapext(ap->a_vp, ap->a_bn, ap->a_bnp,
ap->a_runp, NULL);
else
return ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL,
NULL, ap->a_runp);
}
/*
* Convert the logical block number of a file to its physical block number
* on the disk within ext4 extents.
*/
static int
ext4_bmapext(struct vnode *vp, int32_t bn, int64_t *bnp, int *runp, int *runb)
{
struct inode *ip;
struct m_ext2fs *fs;
struct ext4_extent *ep;
struct ext4_extent_path path = { .ep_bp = NULL };
daddr_t lbn;
int error = 0;
ip = VTOI(vp);
fs = ip->i_e2fs;
lbn = bn;
/* XXX: Should not initialize on error? */
if (runp != NULL)
*runp = 0;
if (runb != NULL)
*runb = 0;
ext4_ext_find_extent(fs, ip, lbn, &path);
if (path.ep_is_sparse) {
*bnp = -1;
if (runp != NULL)
*runp = path.ep_sparse_ext.e_len -
(lbn - path.ep_sparse_ext.e_blk) - 1;
if (runb != NULL)
*runb = lbn - path.ep_sparse_ext.e_blk;
} else {
if (path.ep_ext == NULL) {
error = EIO;
goto out;
}
ep = path.ep_ext;
*bnp = fsbtodb(fs, lbn - ep->e_blk
+ (ep->e_start_lo | (daddr_t)ep->e_start_hi << 32));
if (*bnp == 0)
*bnp = -1;
if (runp != NULL)
*runp = ep->e_len - (lbn - ep->e_blk) - 1;
if (runb != NULL)
*runb = lbn - ep->e_blk;
}
out:
if (path.ep_bp != NULL) {
brelse(path.ep_bp, 0);
}
return error;
}
/*
* Indirect blocks are now on the vnode for the file. They are given negative
* logical block numbers. Indirect blocks are addressed by the negative
* address of the first data block to which they point. Double indirect blocks
* are addressed by one less than the address of the first indirect block to
* which they point. Triple indirect blocks are addressed by one less than
* the address of the first double indirect block to which they point.
*
* ext2fs_bmaparray does the bmap conversion, and if requested returns the
* array of logical blocks which must be traversed to get to a block.
* Each entry contains the offset into that block that gets you to the
* next block and the disk address of the block (if it is assigned).
*/
int
ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap,
int *nump, int *runp)
{
struct inode *ip;
struct buf *bp, *cbp;
struct ufsmount *ump;
struct mount *mp;
struct indir a[EXT2FS_NIADDR+1], *xap;
daddr_t daddr;
daddr_t metalbn;
int error, maxrun = 0, num;
ip = VTOI(vp);
mp = vp->v_mount;
ump = ip->i_ump;
#ifdef DIAGNOSTIC
if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL))
panic("ext2fs_bmaparray: invalid arguments");
#endif
if (runp) {
/*
* XXX
* If MAXBSIZE is the largest transfer the disks can handle,
* we probably want maxrun to be 1 block less so that we
* don't create a block larger than the device can handle.
*/
*runp = 0;
maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
}
if (bn >= 0 && bn < EXT2FS_NDADDR) {
/* XXX ondisk32 */
*bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn]));
if (*bnp == 0)
*bnp = -1;
else if (runp)
/* XXX ondisk32 */
for (++bn; bn < EXT2FS_NDADDR && *runp < maxrun &&
is_sequential(ump, (daddr_t)fs2h32(ip->i_e2fs_blocks[bn - 1]),
(daddr_t)fs2h32(ip->i_e2fs_blocks[bn]));
++bn, ++*runp);
return (0);
}
xap = ap == NULL ? a : ap;
if (!nump)
nump = &num;
if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0)
return (error);
num = *nump;
/* Get disk address out of indirect block array */
/* XXX ondisk32 */
daddr = fs2h32(ip->i_e2fs_blocks[EXT2FS_NDADDR + xap->in_off]);
#ifdef DIAGNOSTIC
if (num > EXT2FS_NIADDR + 1 || num < 1) {
printf("ext2fs_bmaparray: num=%d\n", num);
panic("ext2fs_bmaparray: num");
}
#endif
for (bp = NULL, ++xap; --num; ++xap) {
/*
* Exit the loop if there is no disk address assigned yet and
* the indirect block isn't in the cache, or if we were
* looking for an indirect block and we've found it.
*/
metalbn = xap->in_lbn;
if (metalbn == bn)
break;
if (daddr == 0) {
mutex_enter(&bufcache_lock);
cbp = incore(vp, metalbn);
mutex_exit(&bufcache_lock);
if (cbp == NULL)
break;
}
/*
* If we get here, we've either got the block in the cache
* or we have a disk address for it, go fetch it.
*/
if (bp)
brelse(bp, 0);
xap->in_exists = 1;
bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0);
if (bp == NULL) {
/*
* getblk() above returns NULL only iff we are
* pagedaemon. See the implementation of getblk
* for detail.
*/
return (ENOMEM);
}
if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
trace(TR_BREADHIT, pack(vp, size), metalbn);
}
#ifdef DIAGNOSTIC
else if (!daddr)
panic("ext2fs_bmaparry: indirect block not in cache");
#endif
else {
trace(TR_BREADMISS, pack(vp, size), metalbn);
bp->b_blkno = blkptrtodb(ump, daddr);
bp->b_flags |= B_READ;
VOP_STRATEGY(vp, bp);
curlwp->l_ru.ru_inblock++; /* XXX */
if ((error = biowait(bp)) != 0) {
brelse(bp, 0);
return (error);
}
}
/* XXX ondisk32 */
daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]);
if (num == 1 && daddr && runp)
/* XXX ondisk32 */
for (bn = xap->in_off + 1;
bn < MNINDIR(ump) && *runp < maxrun &&
is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1],
((int32_t *)bp->b_data)[bn]);
++bn, ++*runp);
}
if (bp)
brelse(bp, 0);
daddr = blkptrtodb(ump, daddr);
*bnp = daddr == 0 ? -1 : daddr;
return (0);
}
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