1 /* $OpenBSD: disksubr.c,v 1.1 2020/05/16 17:11:14 kettenis Exp $ */ 2 /* $NetBSD: disksubr.c,v 1.21 1996/05/03 19:42:03 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1996 Theo de Raadt 6 * Copyright (c) 1982, 1986, 1988 Regents of the University of California. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. 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 34 #include <sys/param.h> 35 #include <sys/buf.h> 36 #include <sys/disklabel.h> 37 #include <sys/disk.h> 38 39 /* 40 * Attempt to read a disk label from a device 41 * using the indicated strategy routine. 42 * The label must be partly set up before this: 43 * secpercyl, secsize and anything required for a block i/o read 44 * operation in the driver's strategy/start routines 45 * must be filled in before calling us. 46 * 47 * If dos partition table requested, attempt to load it and 48 * find disklabel inside a DOS partition. 49 * 50 * We would like to check if each MBR has a valid DOSMBR_SIGNATURE, but 51 * we cannot because it doesn't always exist. So.. we assume the 52 * MBR is valid. 53 */ 54 int 55 readdisklabel(dev_t dev, void (*strat)(struct buf *), 56 struct disklabel *lp, int spoofonly) 57 { 58 struct buf *bp = NULL; 59 int error; 60 61 if ((error = initdisklabel(lp))) 62 goto done; 63 64 /* get a buffer and initialize it */ 65 bp = geteblk(lp->d_secsize); 66 bp->b_dev = dev; 67 68 error = readdoslabel(bp, strat, lp, NULL, spoofonly); 69 if (error == 0) 70 goto done; 71 72 #if defined(CD9660) 73 error = iso_disklabelspoof(dev, strat, lp); 74 if (error == 0) 75 goto done; 76 #endif 77 #if defined(UDF) 78 error = udf_disklabelspoof(dev, strat, lp); 79 if (error == 0) 80 goto done; 81 #endif 82 83 done: 84 if (bp) { 85 bp->b_flags |= B_INVAL; 86 brelse(bp); 87 } 88 disk_change = 1; 89 return (error); 90 } 91 92 /* 93 * Write disk label back to device after modification. 94 */ 95 int 96 writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp) 97 { 98 daddr_t partoff = -1; 99 int error = EIO; 100 int offset; 101 struct disklabel *dlp; 102 struct buf *bp = NULL; 103 104 /* get a buffer and initialize it */ 105 bp = geteblk(lp->d_secsize); 106 bp->b_dev = dev; 107 108 if (readdoslabel(bp, strat, lp, &partoff, 1) != 0) 109 goto done; 110 111 /* Read it in, slap the new label in, and write it back out */ 112 error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp, partoff + 113 DOS_LABELSECTOR)); 114 if (error) 115 goto done; 116 offset = DL_BLKOFFSET(lp, partoff + DOS_LABELSECTOR); 117 118 dlp = (struct disklabel *)(bp->b_data + offset); 119 *dlp = *lp; 120 CLR(bp->b_flags, B_READ | B_WRITE | B_DONE); 121 SET(bp->b_flags, B_BUSY | B_WRITE | B_RAW); 122 (*strat)(bp); 123 error = biowait(bp); 124 125 done: 126 if (bp) { 127 bp->b_flags |= B_INVAL; 128 brelse(bp); 129 } 130 disk_change = 1; 131 return (error); 132 } 133