subr_disk_4bsd.c revision 1.1
1 /* $NetBSD: subr_disk_4bsd.c,v 1.1 2026/04/04 00:23:09 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: subr_disk_4bsd.c,v 1.1 2026/04/04 00:23:09 thorpej Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/buf.h> 45 #include <sys/disk.h> 46 #include <sys/disklabel.h> 47 48 /* 49 * Implementation of readdisklabel() and writedisklabel() for the simple 50 * "basic scheme from 4BSD". 51 * 52 * Lifted verbatim from the hp300 copy. 53 */ 54 55 /* 56 * Attempt to read a disk label from a device using the indicated strategy 57 * routine. The label must be partly set up before this: secpercyl and 58 * anything required in the strategy routine (e.g., sector size) must be 59 * filled in before calling us. Returns null on success and an error 60 * string on failure. 61 */ 62 const char * 63 readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 64 struct cpu_disklabel *osdep) 65 { 66 struct buf *bp; 67 struct disklabel *dlp; 68 const char *msg = NULL; 69 int i; 70 71 if (lp->d_secsize == 0) 72 lp->d_secsize = DEV_BSIZE; 73 if (lp->d_secperunit == 0) 74 lp->d_secperunit = 0x1fffffff; 75 if (lp->d_npartitions < RAW_PART + 1) 76 lp->d_npartitions = RAW_PART + 1; 77 for (i = 0; i < RAW_PART; i++) { 78 lp->d_partitions[i].p_size = 0; 79 lp->d_partitions[i].p_offset = 0; 80 } 81 if (lp->d_partitions[RAW_PART].p_size == 0) 82 lp->d_partitions[RAW_PART].p_size = lp->d_secperunit; 83 lp->d_partitions[RAW_PART].p_offset = 0; 84 85 lp->d_partitions[0].p_size = lp->d_partitions[RAW_PART].p_size; 86 lp->d_partitions[0].p_fstype = FS_BSDFFS; 87 88 bp = geteblk((int)lp->d_secsize); 89 bp->b_dev = dev; 90 bp->b_blkno = LABELSECTOR; 91 bp->b_bcount = lp->d_secsize; 92 bp->b_flags |= B_READ; 93 bp->b_cylinder = LABELSECTOR / lp->d_secpercyl; 94 (*strat)(bp); 95 if (biowait(bp)) 96 msg = "I/O error"; 97 else for (dlp = (struct disklabel *)bp->b_data; 98 dlp <= (struct disklabel *)((char *)bp->b_data + 99 DEV_BSIZE - sizeof(*dlp)); 100 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 101 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) { 102 if (msg == NULL) 103 msg = "no disk label"; 104 } else if (dlp->d_npartitions > MAXPARTITIONS || 105 dkcksum(dlp) != 0) 106 msg = "disk label corrupted"; 107 else { 108 *lp = *dlp; 109 msg = NULL; 110 break; 111 } 112 } 113 brelse(bp, 0); 114 return msg; 115 } 116 117 /* 118 * Write disk label back to device after modification. 119 */ 120 int 121 writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 122 struct cpu_disklabel *osdep) 123 { 124 struct buf *bp; 125 struct disklabel *dlp; 126 int labelpart; 127 int error = 0; 128 129 labelpart = DISKPART(dev); 130 if (lp->d_partitions[labelpart].p_offset != 0) { 131 if (lp->d_partitions[0].p_offset != 0) 132 return EXDEV; /* not quite right */ 133 labelpart = 0; 134 } 135 bp = geteblk((int)lp->d_secsize); 136 bp->b_dev = MAKEDISKDEV(major(dev), DISKUNIT(dev), labelpart); 137 bp->b_blkno = LABELSECTOR; 138 bp->b_bcount = lp->d_secsize; 139 bp->b_flags |= B_READ; 140 (*strat)(bp); 141 if ((error = biowait(bp)) != 0) 142 goto done; 143 for (dlp = (struct disklabel *)bp->b_data; 144 dlp <= (struct disklabel *) 145 ((char *)bp->b_data + lp->d_secsize - sizeof(*dlp)); 146 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 147 if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC && 148 dkcksum(dlp) == 0) { 149 *dlp = *lp; 150 bp->b_oflags &= ~(BO_DONE); 151 bp->b_flags &= ~(B_READ); 152 bp->b_flags |= B_WRITE; 153 (*strat)(bp); 154 error = biowait(bp); 155 goto done; 156 } 157 } 158 error = ESRCH; 159 done: 160 brelse(bp, 0); 161 return error; 162 } 163
Indexes created Tue Oct 27 00:25:24 UTC 2026