disksubr.c revision 1.1
1/* 2 * Copyright (c) 1982, 1986, 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 34 * $Id: disksubr.c,v 1.1 1994/01/15 02:04:56 deraadt Exp $ 35 */ 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/buf.h> 40#include <sys/disklabel.h> 41#include <sys/syslog.h> 42 43/* XXX encoding of disk minor numbers, should be elsewhere... */ 44#define dkunit(dev) (minor(dev) >> 3) 45#define dkpart(dev) (minor(dev) & 7) 46#define dkminor(unit, part) (((unit) << 3) | (part)) 47 48#define b_cylin b_resid 49 50/* 51 * Attempt to read a disk label from a device 52 * using the indicated stategy routine. 53 * The label must be partly set up before this: 54 * secpercyl and anything required in the strategy routine 55 * (e.g., sector size) must be filled in before calling us. 56 * Returns null on success and an error string on failure. 57 */ 58char * 59readdisklabel(dev, strat, lp, osdep) 60 dev_t dev; 61 void (*strat)(); 62 register struct disklabel *lp; 63 struct cpu_disklabel *osdep; 64{ 65 register struct buf *bp; 66 struct disklabel *dlp; 67 char *msg = NULL; 68 69 if (lp->d_secperunit == 0) 70 lp->d_secperunit = 0x1fffffff; 71 lp->d_npartitions = 1; 72 if (lp->d_partitions[0].p_size == 0) 73 lp->d_partitions[0].p_size = 0x1fffffff; 74 lp->d_partitions[0].p_offset = 0; 75 76 bp = geteblk((int)lp->d_secsize); 77 bp->b_dev = dev; 78 bp->b_blkno = LABELSECTOR; 79 bp->b_bcount = lp->d_secsize; 80 bp->b_flags = B_BUSY | B_READ; 81 bp->b_cylin = LABELSECTOR / lp->d_secpercyl; 82 (*strat)(bp); 83 if (biowait(bp)) { 84 msg = "I/O error"; 85 } else for (dlp = (struct disklabel *)bp->b_un.b_addr; 86 dlp <= (struct disklabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp)); 87 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 88 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) { 89 if (msg == NULL) 90 msg = "no disk label"; 91 } else if (dlp->d_npartitions > MAXPARTITIONS || 92 dkcksum(dlp) != 0) 93 msg = "disk label corrupted"; 94 else { 95 *lp = *dlp; 96 msg = NULL; 97 break; 98 } 99 } 100 bp->b_flags = B_INVAL | B_AGE; 101 brelse(bp); 102 return (msg); 103} 104 105/* 106 * Check new disk label for sensibility 107 * before setting it. 108 */ 109setdisklabel(olp, nlp, openmask, osdep) 110 register struct disklabel *olp, *nlp; 111 u_long openmask; 112 struct cpu_disklabel *osdep; 113{ 114 register i; 115 register struct partition *opp, *npp; 116 117 if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC || 118 dkcksum(nlp) != 0) 119 return (EINVAL); 120 while ((i = ffs((long)openmask)) != 0) { 121 i--; 122 openmask &= ~(1 << i); 123 if (nlp->d_npartitions <= i) 124 return (EBUSY); 125 opp = &olp->d_partitions[i]; 126 npp = &nlp->d_partitions[i]; 127 if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size) 128 return (EBUSY); 129 /* 130 * Copy internally-set partition information 131 * if new label doesn't include it. XXX 132 */ 133 if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) { 134 npp->p_fstype = opp->p_fstype; 135 npp->p_fsize = opp->p_fsize; 136 npp->p_frag = opp->p_frag; 137 npp->p_cpg = opp->p_cpg; 138 } 139 } 140 nlp->d_checksum = 0; 141 nlp->d_checksum = dkcksum(nlp); 142 *olp = *nlp; 143 return (0); 144} 145 146/* encoding of disk minor numbers, should be elsewhere... */ 147#define dkunit(dev) (minor(dev) >> 3) 148#define dkpart(dev) (minor(dev) & 07) 149#define dkminor(unit, part) (((unit) << 3) | (part)) 150 151/* 152 * Write disk label back to device after modification. 153 */ 154writedisklabel(dev, strat, lp, osdep) 155 dev_t dev; 156 void (*strat)(); 157 register struct disklabel *lp; 158 struct cpu_disklabel *osdep; 159{ 160 struct buf *bp; 161 struct disklabel *dlp; 162 int labelpart; 163 int error = 0; 164 165 labelpart = dkpart(dev); 166 if (lp->d_partitions[labelpart].p_offset != 0) { 167 if (lp->d_partitions[0].p_offset != 0) 168 return (EXDEV); /* not quite right */ 169 labelpart = 0; 170 } 171 bp = geteblk((int)lp->d_secsize); 172 bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), labelpart)); 173 bp->b_blkno = LABELSECTOR; 174 bp->b_bcount = lp->d_secsize; 175 bp->b_flags = B_READ; 176 (*strat)(bp); 177 if (error = biowait(bp)) 178 goto done; 179 for (dlp = (struct disklabel *)bp->b_un.b_addr; 180 dlp <= (struct disklabel *) 181 (bp->b_un.b_addr + lp->d_secsize - sizeof(*dlp)); 182 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 183 if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC && 184 dkcksum(dlp) == 0) { 185 *dlp = *lp; 186 bp->b_flags = B_WRITE; 187 (*strat)(bp); 188 error = biowait(bp); 189 goto done; 190 } 191 } 192 error = ESRCH; 193done: 194 brelse(bp); 195 return (error); 196} 197