diff options
Diffstat (limited to 'usr.sbin/makefs/ffs/ufs_bmap.c')
| -rw-r--r-- | usr.sbin/makefs/ffs/ufs_bmap.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/usr.sbin/makefs/ffs/ufs_bmap.c b/usr.sbin/makefs/ffs/ufs_bmap.c new file mode 100644 index 0000000..b65b416 --- /dev/null +++ b/usr.sbin/makefs/ffs/ufs_bmap.c @@ -0,0 +1,140 @@ +/* $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 */ + +/* + * 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 >= 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 NIADDR - i is the number + * of levels of indirection needed to locate the requested block. + */ + + bn -= NDADDR; + for (lbc = 0, i = 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 + NIADDR - i); + else + metalbn = -(-realbn - bn + 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 = NIADDR - i; + ap++; + for (++numlevels; i <= 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); +} |
