freebsd-dev/usr.sbin/makefs/ffs/ufs_bmap.c
Pedro F. Giffuni 8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00

143 lines
4.5 KiB
C

/* $NetBSD: ufs_bmap.c,v 1.14 2004/06/20 22:20:18 jmc Exp $ */
/* From: NetBSD: ufs_bmap.c,v 1.14 2001/11/08 05:00:51 chs Exp */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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 8.8 (Berkeley) 8/11/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/time.h>
#include <assert.h>
#include <errno.h>
#include <strings.h>
#include "makefs.h"
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include "ffs/ufs_bswap.h"
#include "ffs/ufs_inode.h"
#include "ffs/ffs_extern.h"
/*
* Create an array of logical block number/offset pairs which represent the
* path of indirect blocks required to access a data block. The first "pair"
* contains the logical block number of the appropriate single, double or
* triple indirect block and the offset into the inode indirect block array.
* Note, the logical block number of the inode single/double/triple indirect
* block appears twice in the array, once with the offset into the i_ffs_ib and
* once with the offset into the page itself.
*/
int
ufs_getlbns(struct inode *ip, daddr_t bn, struct indir *ap, int *nump)
{
daddr_t metalbn, realbn;
int64_t blockcnt;
int lbc;
int i, numlevels, off;
u_long lognindir;
lognindir = ffs(NINDIR(ip->i_fs)) - 1;
if (nump)
*nump = 0;
numlevels = 0;
realbn = bn;
if ((long)bn < 0)
bn = -(long)bn;
assert (bn >= UFS_NDADDR);
/*
* Determine the number of levels of indirection. After this loop
* is done, blockcnt indicates the number of data blocks possible
* at the given level of indirection, and UFS_NIADDR - i is the number
* of levels of indirection needed to locate the requested block.
*/
bn -= UFS_NDADDR;
for (lbc = 0, i = UFS_NIADDR;; i--, bn -= blockcnt) {
if (i == 0)
return (EFBIG);
lbc += lognindir;
blockcnt = (int64_t)1 << lbc;
if (bn < blockcnt)
break;
}
/* Calculate the address of the first meta-block. */
if (realbn >= 0)
metalbn = -(realbn - bn + UFS_NIADDR - i);
else
metalbn = -(-realbn - bn + UFS_NIADDR - i);
/*
* At each iteration, off is the offset into the bap array which is
* an array of disk addresses at the current level of indirection.
* The logical block number and the offset in that block are stored
* into the argument array.
*/
ap->in_lbn = metalbn;
ap->in_off = off = UFS_NIADDR - i;
ap++;
for (++numlevels; i <= UFS_NIADDR; i++) {
/* If searching for a meta-data block, quit when found. */
if (metalbn == realbn)
break;
lbc -= lognindir;
blockcnt = (int64_t)1 << lbc;
off = (bn >> lbc) & (NINDIR(ip->i_fs) - 1);
++numlevels;
ap->in_lbn = metalbn;
ap->in_off = off;
++ap;
metalbn -= -1 + (off << lbc);
}
if (nump)
*nump = numlevels;
return (0);
}