disksubr.c revision 1.3
1/* $NetBSD: disksubr.c,v 1.3 1994/10/26 21:10:20 cgd Exp $ */ 2 3/* 4 * Copyright (c) 1982, 1986, 1988 Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 36 */ 37 38#include "param.h" 39#include "systm.h" 40#include "buf.h" 41#include "disklabel.h" 42#include "syslog.h" 43 44#define b_cylin b_resid 45 46/* 47 * Attempt to read a disk label from a device 48 * using the indicated stategy routine. 49 * The label must be partly set up before this: 50 * secpercyl and anything required in the strategy routine 51 * (e.g., sector size) must be filled in before calling us. 52 * Returns null on success and an error string on failure. 53 */ 54char * 55readdisklabel(dev, strat, lp, osdep) 56 dev_t dev; 57 void (*strat)(); 58 register struct disklabel *lp; 59 struct cpu_disklabel *osdep; 60{ 61 register struct buf *bp; 62 struct disklabel *dlp; 63 char *msg = NULL; 64 65 if (lp->d_secperunit == 0) 66 lp->d_secperunit = 0x1fffffff; 67 lp->d_npartitions = 1; 68 if (lp->d_partitions[0].p_size == 0) 69 lp->d_partitions[0].p_size = 0x1fffffff; 70 lp->d_partitions[0].p_offset = 0; 71 72 bp = geteblk((int)lp->d_secsize); 73 bp->b_dev = dev; 74 bp->b_blkno = LABELSECTOR; 75 bp->b_bcount = lp->d_secsize; 76 bp->b_flags = B_BUSY | B_READ; 77 bp->b_cylin = LABELSECTOR / lp->d_secpercyl; 78 (*strat)(bp); 79 if (biowait(bp)) { 80 msg = "I/O error"; 81 } else for (dlp = (struct disklabel *)bp->b_un.b_addr; 82 dlp <= (struct disklabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp)); 83 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 84 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) { 85 if (msg == NULL) 86 msg = "no disk label"; 87 } else if (dlp->d_npartitions > MAXPARTITIONS || 88 dkcksum(dlp) != 0) 89 msg = "disk label corrupted"; 90 else { 91 *lp = *dlp; 92 msg = NULL; 93 break; 94 } 95 } 96 bp->b_flags = B_INVAL | B_AGE; 97 brelse(bp); 98 return (msg); 99} 100 101/* 102 * Check new disk label for sensibility 103 * before setting it. 104 */ 105setdisklabel(olp, nlp, openmask, osdep) 106 register struct disklabel *olp, *nlp; 107 u_long openmask; 108 struct cpu_disklabel *osdep; 109{ 110 register i; 111 register struct partition *opp, *npp; 112 113 if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC || 114 dkcksum(nlp) != 0) 115 return (EINVAL); 116 while ((i = ffs((long)openmask)) != 0) { 117 i--; 118 openmask &= ~(1 << i); 119 if (nlp->d_npartitions <= i) 120 return (EBUSY); 121 opp = &olp->d_partitions[i]; 122 npp = &nlp->d_partitions[i]; 123 if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size) 124 return (EBUSY); 125 /* 126 * Copy internally-set partition information 127 * if new label doesn't include it. XXX 128 */ 129 if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) { 130 npp->p_fstype = opp->p_fstype; 131 npp->p_fsize = opp->p_fsize; 132 npp->p_frag = opp->p_frag; 133 npp->p_cpg = opp->p_cpg; 134 } 135 } 136 nlp->d_checksum = 0; 137 nlp->d_checksum = dkcksum(nlp); 138 *olp = *nlp; 139 return (0); 140} 141 142/* encoding of disk minor numbers, should be elsewhere... */ 143#define dkunit(dev) (minor(dev) >> 3) 144#define dkpart(dev) (minor(dev) & 07) 145#define dkminor(unit, part) (((unit) << 3) | (part)) 146 147/* 148 * Write disk label back to device after modification. 149 */ 150writedisklabel(dev, strat, lp, osdep) 151 dev_t dev; 152 void (*strat)(); 153 register struct disklabel *lp; 154 struct cpu_disklabel *osdep; 155{ 156 struct buf *bp; 157 struct disklabel *dlp; 158 int labelpart; 159 int error = 0; 160 161 labelpart = dkpart(dev); 162 if (lp->d_partitions[labelpart].p_offset != 0) { 163 if (lp->d_partitions[0].p_offset != 0) 164 return (EXDEV); /* not quite right */ 165 labelpart = 0; 166 } 167 bp = geteblk((int)lp->d_secsize); 168 bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), labelpart)); 169 bp->b_blkno = LABELSECTOR; 170 bp->b_bcount = lp->d_secsize; 171 bp->b_flags = B_READ; 172 (*strat)(bp); 173 if (error = biowait(bp)) 174 goto done; 175 for (dlp = (struct disklabel *)bp->b_un.b_addr; 176 dlp <= (struct disklabel *) 177 (bp->b_un.b_addr + lp->d_secsize - sizeof(*dlp)); 178 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 179 if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC && 180 dkcksum(dlp) == 0) { 181 *dlp = *lp; 182 bp->b_flags = B_WRITE; 183 (*strat)(bp); 184 error = biowait(bp); 185 goto done; 186 } 187 } 188 error = ESRCH; 189done: 190 brelse(bp); 191 return (error); 192} 193