| File: | src/usr.sbin/makefs/ffs/ufs_bmap.c |
| Warning: | line 112, column 15 Although the value stored to 'off' is used in the enclosing expression, the value is never actually read from 'off' |
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| 1 | /* $OpenBSD: ufs_bmap.c,v 1.7 2021/10/06 00:40:41 deraadt Exp $ */ |
| 2 | /* $NetBSD: ufs_bmap.c,v 1.18 2013/06/19 17:51:27 dholland Exp $ */ |
| 3 | /* From: NetBSD: ufs_bmap.c,v 1.14 2001/11/08 05:00:51 chs Exp */ |
| 4 | |
| 5 | /* |
| 6 | * Copyright (c) 1989, 1991, 1993 |
| 7 | * The Regents of the University of California. All rights reserved. |
| 8 | * (c) UNIX System Laboratories, Inc. |
| 9 | * All or some portions of this file are derived from material licensed |
| 10 | * to the University of California by American Telephone and Telegraph |
| 11 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 12 | * the permission of UNIX System Laboratories, Inc. |
| 13 | * |
| 14 | * Redistribution and use in source and binary forms, with or without |
| 15 | * modification, are permitted provided that the following conditions |
| 16 | * are met: |
| 17 | * 1. Redistributions of source code must retain the above copyright |
| 18 | * notice, this list of conditions and the following disclaimer. |
| 19 | * 2. Redistributions in binary form must reproduce the above copyright |
| 20 | * notice, this list of conditions and the following disclaimer in the |
| 21 | * documentation and/or other materials provided with the distribution. |
| 22 | * 3. Neither the name of the University nor the names of its contributors |
| 23 | * may be used to endorse or promote products derived from this software |
| 24 | * without specific prior written permission. |
| 25 | * |
| 26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 36 | * SUCH DAMAGE. |
| 37 | * |
| 38 | * @(#)ufs_bmap.c 8.8 (Berkeley) 8/11/95 |
| 39 | */ |
| 40 | |
| 41 | #include <sys/time.h> |
| 42 | |
| 43 | #include <assert.h> |
| 44 | #include <errno(*__errno()).h> |
| 45 | #include <strings.h> |
| 46 | |
| 47 | #include "makefs.h" |
| 48 | |
| 49 | #include <ufs/ufs/dinode.h> |
| 50 | #include <ufs/ffs/fs.h> |
| 51 | |
| 52 | #include "ffs/ufs_inode.h" |
| 53 | #include "ffs/ffs_extern.h" |
| 54 | |
| 55 | /* |
| 56 | * Create an array of logical block number/offset pairs which represent the |
| 57 | * path of indirect blocks required to access a data block. The first "pair" |
| 58 | * contains the logical block number of the appropriate single, double or |
| 59 | * triple indirect block and the offset into the inode indirect block array. |
| 60 | * Note, the logical block number of the inode single/double/triple indirect |
| 61 | * block appears twice in the array, once with the offset into the i_ffs_ib and |
| 62 | * once with the offset into the page itself. |
| 63 | */ |
| 64 | int |
| 65 | ufs_getlbns(struct inode *ip, daddr_t bn, struct indir *ap, int *nump) |
| 66 | { |
| 67 | daddr_t metalbn, realbn; |
| 68 | int64_t blockcnt; |
| 69 | int lbc; |
| 70 | int i, numlevels, off; |
| 71 | u_long lognindir; |
| 72 | |
| 73 | lognindir = ffs(NINDIR(ip->i_fs)((ip->i_fs)->fs_nindir)) - 1; |
| 74 | if (nump) |
| 75 | *nump = 0; |
| 76 | numlevels = 0; |
| 77 | realbn = bn; |
| 78 | if ((long)bn < 0) |
| 79 | bn = -(long)bn; |
| 80 | |
| 81 | assert (bn >= NDADDR)((bn >= 12) ? (void)0 : __assert2("/usr/src/usr.sbin/makefs/ffs/ufs_bmap.c" , 81, __func__, "bn >= NDADDR")); |
| 82 | |
| 83 | /* |
| 84 | * Determine the number of levels of indirection. After this loop |
| 85 | * is done, blockcnt indicates the number of data blocks possible |
| 86 | * at the given level of indirection, and NIADDR - i is the number |
| 87 | * of levels of indirection needed to locate the requested block. |
| 88 | */ |
| 89 | |
| 90 | bn -= NDADDR12; |
| 91 | for (lbc = 0, i = NIADDR3;; i--, bn -= blockcnt) { |
| 92 | if (i == 0) |
| 93 | return (EFBIG27); |
| 94 | |
| 95 | lbc += lognindir; |
| 96 | blockcnt = (int64_t)1 << lbc; |
| 97 | |
| 98 | if (bn < blockcnt) |
| 99 | break; |
| 100 | } |
| 101 | |
| 102 | /* Calculate the address of the first meta-block. */ |
| 103 | metalbn = -((realbn >= 0 ? realbn : -realbn) - bn + NIADDR3 - i); |
| 104 | |
| 105 | /* |
| 106 | * At each iteration, off is the offset into the bap array which is |
| 107 | * an array of disk addresses at the current level of indirection. |
| 108 | * The logical block number and the offset in that block are stored |
| 109 | * into the argument array. |
| 110 | */ |
| 111 | ap->in_lbn = metalbn; |
| 112 | ap->in_off = off = NIADDR3 - i; |
Although the value stored to 'off' is used in the enclosing expression, the value is never actually read from 'off' | |
| 113 | ap->in_exists = 0; |
| 114 | ap++; |
| 115 | for (++numlevels; i <= NIADDR3; i++) { |
| 116 | /* If searching for a meta-data block, quit when found. */ |
| 117 | if (metalbn == realbn) |
| 118 | break; |
| 119 | |
| 120 | lbc -= lognindir; |
| 121 | blockcnt = (int64_t)1 << lbc; |
| 122 | off = (bn >> lbc) & (NINDIR(ip->i_fs)((ip->i_fs)->fs_nindir) - 1); |
| 123 | |
| 124 | ++numlevels; |
| 125 | ap->in_lbn = metalbn; |
| 126 | ap->in_off = off; |
| 127 | ap->in_exists = 0; |
| 128 | ++ap; |
| 129 | |
| 130 | metalbn -= -1 + (off << lbc); |
| 131 | } |
| 132 | if (nump) |
| 133 | *nump = numlevels; |
| 134 | return (0); |
| 135 | } |