1 /* $OpenBSD: disksubr.c,v 1.1.1.1 2009/08/17 06:34:30 miod 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/systm.h> 36 #include <sys/buf.h> 37 #include <sys/disklabel.h> 38 #include <sys/disk.h> 39 40 /* 41 * Attempt to read a disk label from a device 42 * using the indicated strategy routine. 43 * The label must be partly set up before this: 44 * secpercyl, secsize and anything required for a block i/o read 45 * operation in the driver's strategy/start routines 46 * must be filled in before calling us. 47 * 48 * If dos partition table requested, attempt to load it and 49 * find disklabel inside a DOS partition. Return buffer 50 * for use in signalling errors if requested. 51 * 52 * We would like to check if each MBR has a valid DOSMBR_SIGNATURE, but 53 * we cannot because it doesn't always exist. So.. we assume the 54 * MBR is valid. 55 * 56 * Returns null on success and an error string on failure. 57 */ 58 int 59 readdisklabel(dev_t dev, void (*strat)(struct buf *), 60 struct disklabel *lp, int spoofonly) 61 { 62 struct buf *bp = NULL; 63 int error; 64 65 if ((error = initdisklabel(lp))) 66 goto done; 67 68 /* get a buffer and initialize it */ 69 bp = geteblk((int)lp->d_secsize); 70 bp->b_dev = dev; 71 72 error = readdoslabel(bp, strat, lp, NULL, spoofonly); 73 if (error == 0) 74 goto done; 75 76 #if defined(CD9660) 77 error = iso_disklabelspoof(dev, strat, lp); 78 if (error == 0) 79 goto done; 80 #endif 81 #if defined(UDF) 82 error = udf_disklabelspoof(dev, strat, lp); 83 if (error == 0) 84 goto done; 85 #endif 86 87 done: 88 if (bp) { 89 bp->b_flags |= B_INVAL; 90 brelse(bp); 91 } 92 return (error); 93 } 94 95 /* 96 * Write disk label back to device after modification. 97 */ 98 int 99 writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp) 100 { 101 int error = EIO, partoff = -1; 102 struct disklabel *dlp; 103 struct buf *bp = NULL; 104 105 /* get a buffer and initialize it */ 106 bp = geteblk((int)lp->d_secsize); 107 bp->b_dev = dev; 108 109 if (readdoslabel(bp, strat, lp, &partoff, 1) != NULL) 110 goto done; 111 112 /* Read it in, slap the new label in, and write it back out */ 113 bp->b_blkno = partoff + LABELSECTOR; 114 bp->b_bcount = lp->d_secsize; 115 bp->b_flags = B_BUSY | B_READ | B_RAW; 116 (*strat)(bp); 117 if ((error = biowait(bp)) != 0) 118 goto done; 119 120 dlp = (struct disklabel *)(bp->b_data + LABELOFFSET); 121 *dlp = *lp; 122 bp->b_flags = B_BUSY | B_WRITE | B_RAW; 123 (*strat)(bp); 124 error = biowait(bp); 125 126 done: 127 if (bp) { 128 bp->b_flags |= B_INVAL; 129 brelse(bp); 130 } 131 return (error); 132 } 133