1/* $NetBSD: disksubr.c,v 1.23 2024/02/10 18:43:51 andvar 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 1.23 2024/02/10 18:43:51 andvar Exp $"); 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/buf.h> 40#include <sys/disklabel.h> 41#include <sys/disk.h> 42#include <sys/syslog.h> 43 44#include "opt_mbr.h" 45 46int fat_types[] = { MBR_PTYPE_FAT12, MBR_PTYPE_FAT16S, 47 MBR_PTYPE_FAT16B, MBR_PTYPE_FAT32, 48 MBR_PTYPE_FAT32L, MBR_PTYPE_FAT16L, 49 -1 }; 50 51#define NO_MBR_SIGNATURE ((struct mbr_partition *) -1) 52 53static struct mbr_partition * 54mbr_findslice(struct mbr_partition* dp, struct buf *bp); 55 56/* 57 * Scan MBR for NetBSD partition. Return NO_MBR_SIGNATURE if no MBR found 58 * Otherwise, copy valid MBR partition-table into dp, and if a NetBSD 59 * partition is found, return a pointer to it; else return NULL. 60 */ 61static 62struct mbr_partition * 63mbr_findslice(struct mbr_partition *dp, struct buf *bp) 64{ 65 struct mbr_partition *ourdp = NULL; 66 uint16_t *mbrmagicp; 67 int i; 68 69 /* Note: Magic number is little-endian. */ 70 mbrmagicp = (uint16_t *)((char*)bp->b_data + MBR_MAGIC_OFFSET); 71 if (*mbrmagicp != MBR_MAGIC) 72 return (NO_MBR_SIGNATURE); 73 74 /* XXX how do we check veracity/bounds of this? */ 75 memcpy(dp, (char*)bp->b_data + MBR_PART_OFFSET, 76 MBR_PART_COUNT * sizeof(*dp)); 77 78 /* look for NetBSD partition */ 79 for (i = 0; i < MBR_PART_COUNT; i++) { 80 if (dp[i].mbrp_type == MBR_PTYPE_NETBSD) { 81 ourdp = &dp[i]; 82 break; 83 } 84 } 85 86#ifdef COMPAT_386BSD_MBRPART 87 /* didn't find it -- look for 386BSD partition */ 88 if (!ourdp) { 89 for (i = 0; i < MBR_PART_COUNT; i++) { 90 if (dp[i].mbrp_type == MBR_PTYPE_386BSD) { 91 printf("WARNING: old BSD partition ID!\n"); 92 ourdp = &dp[i]; 93 /* 94 * If more than one matches, take last, 95 * as NetBSD install tool does. 96 */ 97#if 0 98 break; 99#endif 100 } 101 } 102 } 103#endif /* COMPAT_386BSD_MBRPART */ 104 105 return (ourdp); 106} 107 108 109/* 110 * Attempt to read a disk label from a device 111 * using the indicated strategy routine. 112 * The label must be partly set up before this: 113 * secpercyl, secsize and anything required for a block i/o read 114 * operation in the driver's strategy/start routines 115 * must be filled in before calling us. 116 * 117 * If dos partition table requested, attempt to load it and 118 * find disklabel inside a DOS partition. Also, if bad block 119 * table needed, attempt to extract it as well. Return buffer 120 * for use in signalling errors if requested. 121 * 122 * Returns null on success and an error string on failure. 123 */ 124const char * 125readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 126 struct cpu_disklabel *osdep) 127{ 128 struct mbr_partition *dp; 129 struct partition *pp; 130 struct dkbad *bdp; 131 struct buf *bp; 132 struct disklabel *dlp; 133 const char *msg = NULL; 134 int dospartoff, cyl, i, *ip; 135 136 /* minimal requirements for archtypal disk label */ 137 if (lp->d_secsize == 0) 138 lp->d_secsize = DEV_BSIZE; 139 if (lp->d_secperunit == 0) 140 lp->d_secperunit = 0x1fffffff; 141#if 0 142 if (lp->d_ncylinders == 16383) { 143 printf("disklabel: Disk > 8G ... readjusting chs %d/%d/%d to ", 144 lp->d_ncylinders, lp->d_ntracks, lp->d_nsectors); 145 lp->d_ncylinders = lp->d_secperunit / lp->d_ntracks / lp->d_nsectors; 146 printf("%d/%d/%d\n", 147 lp->d_ncylinders, lp->d_ntracks, lp->d_nsectors); 148 } 149#endif 150 lp->d_npartitions = RAW_PART + 1; 151 for (i = 0; i < RAW_PART; i++) { 152 lp->d_partitions[i].p_size = 0; 153 lp->d_partitions[i].p_offset = 0; 154 } 155 if (lp->d_partitions[i].p_size == 0) 156 lp->d_partitions[i].p_size = 0x1fffffff; 157 lp->d_partitions[i].p_offset = 0; 158 159 /* get a buffer and initialize it */ 160 bp = geteblk((int)lp->d_secsize); 161 bp->b_dev = dev; 162 163 /* do dos partitions in the process of getting disklabel? */ 164 dospartoff = 0; 165 cyl = LABELSECTOR / lp->d_secpercyl; 166 if (!osdep) 167 goto nombrpart; 168 dp = osdep->mbrparts; 169 170 /* read master boot record */ 171 bp->b_blkno = MBR_BBSECTOR; 172 bp->b_bcount = lp->d_secsize; 173 bp->b_flags |= B_READ; 174 bp->b_cylinder = MBR_BBSECTOR / lp->d_secpercyl; 175 (*strat)(bp); 176 177 /* if successful, wander through dos partition table */ 178 if (biowait(bp)) { 179 msg = "dos partition I/O error"; 180 goto done; 181 } else { 182 struct mbr_partition *ourdp = NULL; 183 184 ourdp = mbr_findslice(dp, bp); 185 if (ourdp == NO_MBR_SIGNATURE) 186 goto nombrpart; 187 188 for (i = 0; i < MBR_PART_COUNT; i++, dp++) { 189 /* Install in partition e, f, g, or h. */ 190 pp = &lp->d_partitions[RAW_PART + 1 + i]; 191 pp->p_offset = dp->mbrp_start; 192 pp->p_size = dp->mbrp_size; 193 for (ip = fat_types; *ip != -1; ip++) { 194 if (dp->mbrp_type == *ip) 195 pp->p_fstype = FS_MSDOS; 196 } 197 if (dp->mbrp_type == MBR_PTYPE_LNXEXT2) 198 pp->p_fstype = FS_EX2FS; 199 200 if (dp->mbrp_type == MBR_PTYPE_NTFS) 201 pp->p_fstype = FS_NTFS; 202 203 /* is this ours? */ 204 if (dp == ourdp) { 205 /* need sector address for SCSI/IDE, 206 cylinder for ESDI/ST506/RLL */ 207 dospartoff = dp->mbrp_start; 208 cyl = MBR_PCYL(dp->mbrp_scyl, dp->mbrp_ssect); 209 210 /* update disklabel with details */ 211 lp->d_partitions[2].p_size = 212 dp->mbrp_size; 213 lp->d_partitions[2].p_offset = 214 dp->mbrp_start; 215#if 0 216 if (lp->d_ntracks != dp->mbrp_ehd + 1 || 217 lp->d_nsectors != DPSECT(dp->mbrp_esect)) { 218 printf("disklabel: BIOS sees chs %d/%d/%d as ", 219 lp->d_ncylinders, lp->d_ntracks, 220 lp->d_nsectors); 221 lp->d_ntracks = dp->mbrp_ehd + 1; 222 lp->d_nsectors = DPSECT(dp->mbrp_esect); 223 lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; 224 lp->d_ncylinders = lp->d_secperunit / lp->d_secpercyl; 225 if (! lp->d_ncylinders) 226 lp->d_ncylinders = 1; 227 printf("%d/%d/%d\n", 228 lp->d_ncylinders, lp->d_ntracks, 229 lp->d_nsectors); 230 } 231#endif 232 } 233 } 234 lp->d_npartitions = RAW_PART + 1 + i; 235 } 236 237nombrpart: 238 /* next, dig out disk label */ 239 bp->b_blkno = dospartoff + LABELSECTOR; 240 bp->b_cylinder = cyl; 241 bp->b_bcount = lp->d_secsize; 242 bp->b_oflags &= ~(BO_DONE); 243 bp->b_flags |= B_READ; 244 (*strat)(bp); 245 246 /* if successful, locate disk label within block and validate */ 247 if (biowait(bp)) { 248 msg = "disk label I/O error"; 249 goto done; 250 } 251 for (dlp = (struct disklabel *)bp->b_data; 252 dlp <= (struct disklabel *)((char*)bp->b_data + 253 lp->d_secsize - sizeof(*dlp)); 254 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 255 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) { 256 if (msg == NULL) 257 msg = "no disk label"; 258 } else if (dlp->d_npartitions > MAXPARTITIONS || 259 dkcksum(dlp) != 0) 260 msg = "disk label corrupted"; 261 else { 262 *lp = *dlp; 263 msg = NULL; 264 break; 265 } 266 } 267 268 if (msg) 269 goto done; 270 271 /* obtain bad sector table if requested and present */ 272 if (osdep && (lp->d_flags & D_BADSECT)) { 273 struct dkbad *db; 274 275 bdp = &osdep->bad; 276 i = 0; 277 do { 278 /* read a bad sector table */ 279 bp->b_oflags &= ~(BO_DONE); 280 bp->b_flags |= B_READ; 281 bp->b_blkno = lp->d_secperunit - lp->d_nsectors + i; 282 if (lp->d_secsize > DEV_BSIZE) 283 bp->b_blkno *= lp->d_secsize / DEV_BSIZE; 284 else 285 bp->b_blkno /= DEV_BSIZE / lp->d_secsize; 286 bp->b_bcount = lp->d_secsize; 287 bp->b_cylinder = lp->d_ncylinders - 1; 288 (*strat)(bp); 289 290 /* if successful, validate, otherwise try another */ 291 if (biowait(bp)) { 292 msg = "bad sector table I/O error"; 293 } else { 294 db = (struct dkbad *)(bp->b_data); 295#define DKBAD_MAGIC 0x4321 296 if (db->bt_mbz == 0 297 && db->bt_flag == DKBAD_MAGIC) { 298 msg = NULL; 299 *bdp = *db; 300 break; 301 } else 302 msg = "bad sector table corrupted"; 303 } 304 } while (bp->b_error != 0 && (i += 2) < 10 && 305 i < lp->d_nsectors); 306 } 307 308done: 309 brelse(bp, 0); 310 return (msg); 311} 312 313/* 314 * Write disk label back to device after modification. 315 */ 316int 317writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 318 struct cpu_disklabel *osdep) 319{ 320 struct mbr_partition *dp; 321 struct buf *bp; 322 struct disklabel *dlp; 323 int error, dospartoff, cyl; 324 325 /* get a buffer and initialize it */ 326 bp = geteblk((int)lp->d_secsize); 327 bp->b_dev = dev; 328 329 /* do dos partitions in the process of getting disklabel? */ 330 dospartoff = 0; 331 cyl = LABELSECTOR / lp->d_secpercyl; 332 if (!osdep) 333 goto nombrpart; 334 dp = osdep->mbrparts; 335 336 /* read master boot record */ 337 bp->b_blkno = MBR_BBSECTOR; 338 bp->b_bcount = lp->d_secsize; 339 bp->b_flags |= B_READ; 340 bp->b_cylinder = MBR_BBSECTOR / lp->d_secpercyl; 341 (*strat)(bp); 342 343 if ((error = biowait(bp)) == 0) { 344 struct mbr_partition *ourdp = NULL; 345 346 ourdp = mbr_findslice(dp, bp); 347 if (ourdp == NO_MBR_SIGNATURE) 348 goto nombrpart; 349 350 if (ourdp) { 351 /* need sector address for SCSI/IDE, 352 cylinder for ESDI/ST506/RLL */ 353 dospartoff = ourdp->mbrp_start; 354 cyl = MBR_PCYL(ourdp->mbrp_scyl, ourdp->mbrp_ssect); 355 } 356 } 357 358nombrpart: 359#ifdef maybe 360 /* disklabel in appropriate location? */ 361 if (lp->d_partitions[2].p_offset != 0 362 && lp->d_partitions[2].p_offset != dospartoff) { 363 error = EXDEV; 364 goto done; 365 } 366#endif 367 368 /* next, dig out disk label */ 369 bp->b_blkno = dospartoff + LABELSECTOR; 370 bp->b_cylinder = cyl; 371 bp->b_bcount = lp->d_secsize; 372 bp->b_oflags &= ~(BO_DONE); 373 bp->b_flags |= B_READ; 374 (*strat)(bp); 375 376 /* if successful, locate disk label within block and validate */ 377 if ((error = biowait(bp)) != 0) 378 goto done; 379 for (dlp = (struct disklabel *)bp->b_data; 380 dlp <= (struct disklabel *)((char *)bp->b_data + 381 lp->d_secsize - sizeof(*dlp)); 382 dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { 383 if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC && 384 dkcksum(dlp) == 0) { 385 *dlp = *lp; 386 bp->b_oflags &= ~(BO_DONE); 387 bp->b_flags &= ~(B_READ); 388 bp->b_flags |= B_WRITE; 389 (*strat)(bp); 390 error = biowait(bp); 391 goto done; 392 } 393 } 394 error = ESRCH; 395 396done: 397 brelse(bp, 0); 398 return (error); 399} 400