1 /* $NetBSD: disksubr.c,v 1.29 2019/04/03 22:10:51 christos 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: disksubr.c,v 1.29 2019/04/03 22:10:51 christos Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/buf.h> 40 #include <sys/device.h> 41 #include <sys/disk.h> 42 #include <sys/disklabel.h> 43 #include <sys/kauth.h> 44 #include <sys/proc.h> 45 46 /* 47 * Attempt to read a disk label from a device 48 * using the indicated strategy 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 */ 54 const char * 55 readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 56 struct cpu_disklabel *osdep) 57 { 58 struct buf *bp; 59 struct disklabel *dlp; 60 const char *msg = NULL; 61 int i; 62 63 if (lp->d_secsize == 0) 64 lp->d_secsize = DEV_BSIZE; 65 if (lp->d_secperunit == 0) 66 lp->d_secperunit = 0x1fffffff; 67 if (lp->d_npartitions < RAW_PART + 1) 68 lp->d_npartitions = RAW_PART + 1; 69 for (i = 0; i < RAW_PART; i++) { 70 lp->d_partitions[i].p_size = 0; 71 lp->d_partitions[i].p_offset = 0; 72 } 73 if (lp->d_partitions[RAW_PART].p_size == 0) 74 lp->d_partitions[RAW_PART].p_size = lp->d_secperunit; 75 lp->d_partitions[RAW_PART].p_offset = 0; 76 77 lp->d_partitions[0].p_size = lp->d_partitions[RAW_PART].p_size; 78 lp->d_partitions[0].p_fstype = FS_BSDFFS; 79 80 bp = geteblk((int)lp->d_secsize); 81 bp->b_dev = dev; 82 bp->b_blkno = LABELSECTOR; 83 bp->b_bcount = lp->d_secsize; 84 bp->b_flags |= B_READ; 85 bp->b_cylinder = LABELSECTOR / lp->d_secpercyl; 86 (*strat)(bp); 87 if (biowait(bp)) 88 msg = "I/O error"; 89 else for (dlp = (struct disklabel *)bp->b_data; 90 dlp <= (struct disklabel *)((char *)bp->b_data + DEV_BSIZE - 91 sizeof(*dlp)); 92 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 93 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) { 94 if (msg == NULL) 95 msg = "no disk label"; 96 } else if (dlp->d_npartitions > MAXPARTITIONS || 97 dkcksum(dlp) != 0) 98 msg = "disk label corrupted"; 99 else { 100 *lp = *dlp; 101 msg = NULL; 102 break; 103 } 104 } 105 brelse(bp, 0); 106 return msg; 107 } 108 109 /* 110 * Write disk label back to device after modification. 111 */ 112 int 113 writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 114 struct cpu_disklabel *osdep) 115 { 116 struct buf *bp; 117 struct disklabel *dlp; 118 int labelpart; 119 int error = 0; 120 121 labelpart = DISKPART(dev); 122 if (lp->d_partitions[labelpart].p_offset != 0) { 123 if (lp->d_partitions[0].p_offset != 0) 124 return EXDEV; /* not quite right */ 125 labelpart = 0; 126 } 127 bp = geteblk((int)lp->d_secsize); 128 bp->b_dev = MAKEDISKDEV(major(dev), DISKUNIT(dev), labelpart); 129 bp->b_blkno = LABELSECTOR; 130 bp->b_bcount = lp->d_secsize; 131 bp->b_flags |= B_READ; 132 (*strat)(bp); 133 if ((error = biowait(bp)) != 0) 134 goto done; 135 for (dlp = (struct disklabel *)bp->b_data; 136 dlp <= (struct disklabel *) 137 ((char *)bp->b_data + lp->d_secsize - sizeof(*dlp)); 138 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 139 if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC && 140 dkcksum(dlp) == 0) { 141 *dlp = *lp; 142 bp->b_flags &= ~(B_READ); 143 bp->b_oflags &= ~(BO_DONE); 144 bp->b_flags |= B_WRITE; 145 (*strat)(bp); 146 error = biowait(bp); 147 goto done; 148 } 149 } 150 error = ESRCH; 151 done: 152 brelse(bp, 0); 153 return error; 154 } 155
Indexes created Sun Oct 25 00:26:45 UTC 2026