Annotation of sys/arch/i386/i386/disksubr.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: disksubr.c,v 1.94 2007/06/20 18:15:45 deraadt 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: #include <sys/reboot.h>
40: #include <sys/conf.h>
41:
42: #include <machine/biosvar.h>
43:
44: /*
45: * Attempt to read a disk label from a device
46: * using the indicated strategy routine.
47: * The label must be partly set up before this:
48: * secpercyl, secsize and anything required for a block i/o read
49: * operation in the driver's strategy/start routines
50: * must be filled in before calling us.
51: *
52: * If dos partition table requested, attempt to load it and
53: * find disklabel inside a DOS partition. Return buffer
54: * for use in signalling errors if requested.
55: *
56: * We would like to check if each MBR has a valid DOSMBR_SIGNATURE, but
57: * we cannot because it doesn't always exist. So.. we assume the
58: * MBR is valid.
59: *
60: * Returns null on success and an error string on failure.
61: */
62: bios_diskinfo_t *bios_getdiskinfo(dev_t dev);
63:
64: char *
65: readdisklabel(dev_t dev, void (*strat)(struct buf *),
66: struct disklabel *lp, int spoofonly)
67: {
68: bios_diskinfo_t *pdi;
69: struct buf *bp = NULL;
70: dev_t devno;
71: char *msg;
72:
73: if ((msg = initdisklabel(lp)))
74: goto done;
75:
76: /* Look for any BIOS geometry information we should honour. */
77: devno = chrtoblk(dev);
78: if (devno == NODEV)
79: devno = dev;
80: pdi = bios_getdiskinfo(MAKEBOOTDEV(major(devno), 0, 0, DISKUNIT(devno),
81: RAW_PART));
82: if (pdi != NULL && pdi->bios_heads > 0 && pdi->bios_sectors > 0) {
83: #ifdef DEBUG
84: printf("Disk GEOM %u/%u/%u -> BIOS GEOM %u/%u/%u\n",
85: lp->d_ntracks, lp->d_nsectors, lp->d_ncylinders,
86: pdi->bios_heads, pdi->bios_sectors,
87: DL_GETDSIZE(lp) / (pdi->bios_heads * pdi->bios_sectors));
88: #endif
89: lp->d_ntracks = pdi->bios_heads;
90: lp->d_nsectors = pdi->bios_sectors;
91: lp->d_secpercyl = pdi->bios_sectors * pdi->bios_heads;
92: lp->d_ncylinders = DL_GETDSIZE(lp) / lp->d_secpercyl;
93: }
94:
95: /* get a buffer and initialize it */
96: bp = geteblk((int)lp->d_secsize);
97: bp->b_dev = dev;
98:
99: msg = readdoslabel(bp, strat, lp, NULL, spoofonly);
100: if (msg == NULL)
101: goto done;
102:
103: #if defined(CD9660)
104: if (iso_disklabelspoof(dev, strat, lp) == 0) {
105: msg = NULL;
106: goto done;
107: }
108: #endif
109: #if defined(UDF)
110: if (udf_disklabelspoof(dev, strat, lp) == 0) {
111: msg = NULL;
112: goto done;
113: }
114: #endif
115:
116: done:
117: if (bp) {
118: bp->b_flags |= B_INVAL;
119: brelse(bp);
120: }
121: return (msg);
122: }
123:
124: /*
125: * Write disk label back to device after modification.
126: */
127: int
128: writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp)
129: {
130: int error = EIO, partoff = -1;
131: struct disklabel *dlp;
132: struct buf *bp = NULL;
133:
134: /* get a buffer and initialize it */
135: bp = geteblk((int)lp->d_secsize);
136: bp->b_dev = dev;
137:
138: if (readdoslabel(bp, strat, lp, &partoff, 1) != NULL)
139: goto done;
140:
141: /* Read it in, slap the new label in, and write it back out */
142: bp->b_blkno = partoff + LABELSECTOR;
143: bp->b_bcount = lp->d_secsize;
144: bp->b_flags = B_BUSY | B_READ;
145: (*strat)(bp);
146: if ((error = biowait(bp)) != 0)
147: goto done;
148:
149: dlp = (struct disklabel *)(bp->b_data + LABELOFFSET);
150: *dlp = *lp;
151: bp->b_flags = B_BUSY | B_WRITE;
152: (*strat)(bp);
153: error = biowait(bp);
154:
155: done:
156: if (bp) {
157: bp->b_flags |= B_INVAL;
158: brelse(bp);
159: }
160: return (error);
161: }
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