/* $NetBSD: disksubr.c,v 1.25 2013/05/16 19:06:44 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1988 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: disksubr.c,v 1.25 2013/05/16 19:06:44 christos Exp $"); #include #include #include #include #include #include #define NO_MBR_SIGNATURE ((struct mbr_partition *) -1) static struct mbr_partition * mbr_findslice(struct mbr_partition* dp, struct buf *bp); /* * Scan MBR for NetBSD partittion. Return NO_MBR_SIGNATURE if no MBR found * Otherwise, copy valid MBR partition-table into dp, and if a NetBSD * partition is found, return a pointer to it; else return NULL. */ static struct mbr_partition * mbr_findslice(struct mbr_partition *dp, struct buf *bp) { struct mbr_partition *ourdp = NULL; uint16_t *mbrmagicp; int i; /* Note: Magic number is little-endian. */ mbrmagicp = (uint16_t *)((char *)bp->b_data + MBR_MAGIC_OFFSET); if (*mbrmagicp != MBR_MAGIC) return NO_MBR_SIGNATURE; /* XXX how do we check veracity/bounds of this? */ memcpy(dp, (char *)bp->b_data + MBR_PART_OFFSET, MBR_PART_COUNT * sizeof(*dp)); /* look for NetBSD partition */ for (i = 0; i < MBR_PART_COUNT; i++) { if (dp[i].mbrp_type == MBR_PTYPE_NETBSD) { ourdp = &dp[i]; break; } } return ourdp; } /* * Attempt to read a disk label from a device * using the indicated strategy routine. * The label must be partly set up before this: * secpercyl, secsize and anything required for a block i/o read * operation in the driver's strategy/start routines * must be filled in before calling us. * * If dos partition table requested, attempt to load it and * find disklabel inside a DOS partition. Also, if bad block * table needed, attempt to extract it as well. Return buffer * for use in signalling errors if requested. * * Returns null on success and an error string on failure. */ const char * readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, struct cpu_disklabel *osdep) { struct mbr_partition *dp; struct partition *pp; struct dkbad *bdp; struct buf *bp; struct disklabel *dlp; const char *msg = NULL; int dospartoff, cyl, i; /* minimal requirements for archtypal disk label */ if (lp->d_secsize == 0) lp->d_secsize = DEV_BSIZE; if (lp->d_secperunit == 0) lp->d_secperunit = 0x1fffffff; #if 0 if (lp->d_ncylinders == 16383) { printf("disklabel: Disk > 8G ... readjusting chs %d/%d/%d to ", lp->d_ncylinders, lp->d_ntracks, lp->d_nsectors); lp->d_ncylinders = lp->d_secperunit / lp->d_ntracks / lp->d_nsectors; printf("%d/%d/%d\n", lp->d_ncylinders, lp->d_ntracks, lp->d_nsectors); } #endif lp->d_npartitions = RAW_PART + 1; for (i = 0; i < RAW_PART; i++) { lp->d_partitions[i].p_size = 0; lp->d_partitions[i].p_offset = 0; } if (lp->d_partitions[i].p_size == 0) lp->d_partitions[i].p_size = 0x1fffffff; lp->d_partitions[i].p_offset = 0; /* get a buffer and initialize it */ bp = geteblk((int)lp->d_secsize); bp->b_dev = dev; /* do dos partitions in the process of getting disklabel? */ dospartoff = 0; cyl = LABELSECTOR / lp->d_secpercyl; if (!osdep) goto nombrpart; dp = osdep->mbrparts; /* read master boot record */ bp->b_blkno = MBR_BBSECTOR; bp->b_bcount = lp->d_secsize; bp->b_flags |= B_READ; bp->b_cylinder = MBR_BBSECTOR / lp->d_secpercyl; (*strat)(bp); /* if successful, wander through dos partition table */ if (biowait(bp)) { msg = "dos partition I/O error"; goto done; } else { struct mbr_partition *ourdp = NULL; ourdp = mbr_findslice(dp, bp); if (ourdp == NO_MBR_SIGNATURE) goto nombrpart; for (i = 0; i < MBR_PART_COUNT; i++, dp++) { /* Install in partition e, f, g, or h. */ pp = &lp->d_partitions[RAW_PART + 1 + i]; pp->p_offset = dp->mbrp_start; pp->p_size = dp->mbrp_size; pp->p_fstype = xlat_mbr_fstype(dp->mbrp_type); /* is this ours? */ if (dp == ourdp) { /* need sector address for SCSI/IDE, cylinder for ESDI/ST506/RLL */ dospartoff = dp->mbrp_start; cyl = MBR_PCYL(dp->mbrp_scyl, dp->mbrp_ssect); /* update disklabel with details */ lp->d_partitions[2].p_size = dp->mbrp_size; lp->d_partitions[2].p_offset = dp->mbrp_start; } } lp->d_npartitions = RAW_PART + 1 + i; } nombrpart: /* next, dig out disk label */ bp->b_blkno = dospartoff + LABELSECTOR; bp->b_cylinder = cyl; bp->b_bcount = lp->d_secsize; bp->b_oflags &= ~(BO_DONE); bp->b_flags |= B_READ; (*strat)(bp); /* if successful, locate disk label within block and validate */ if (biowait(bp)) { msg = "disk label I/O error"; goto done; } for (dlp = (struct disklabel *)bp->b_data; dlp <= (struct disklabel *)((char *)bp->b_data + lp->d_secsize - sizeof(*dlp)); dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) { if (msg == NULL) msg = "no disk label"; } else if (dlp->d_npartitions > MAXPARTITIONS || dkcksum(dlp) != 0) msg = "disk label corrupted"; else { *lp = *dlp; msg = NULL; break; } } if (msg) goto done; /* obtain bad sector table if requested and present */ if (osdep && (lp->d_flags & D_BADSECT)) { struct dkbad *db; bdp = &osdep->bad; i = 0; do { /* read a bad sector table */ bp->b_oflags &= ~(BO_DONE); bp->b_flags |= B_READ; bp->b_blkno = lp->d_secperunit - lp->d_nsectors + i; if (lp->d_secsize > DEV_BSIZE) bp->b_blkno *= lp->d_secsize / DEV_BSIZE; else bp->b_blkno /= DEV_BSIZE / lp->d_secsize; bp->b_bcount = lp->d_secsize; bp->b_cylinder = lp->d_ncylinders - 1; (*strat)(bp); /* if successful, validate, otherwise try another */ if (biowait(bp)) { msg = "bad sector table I/O error"; } else { db = (struct dkbad *)(bp->b_data); #define DKBAD_MAGIC 0x4321 if (db->bt_mbz == 0 && db->bt_flag == DKBAD_MAGIC) { msg = NULL; *bdp = *db; break; } else msg = "bad sector table corrupted"; } } while (bp->b_error != 0 && (i += 2) < 10 && i < lp->d_nsectors); } done: brelse(bp, 0); return msg; } /* * Check new disk label for sensibility * before setting it. */ int setdisklabel(struct disklabel *olp, struct disklabel *nlp, u_long openmask, struct cpu_disklabel *osdep) { int i; struct partition *opp, *npp; /* sanity clause */ if (nlp->d_secpercyl == 0 || nlp->d_secsize == 0 || (nlp->d_secsize % DEV_BSIZE) != 0) return EINVAL; /* special case to allow disklabel to be invalidated */ if (nlp->d_magic == 0xffffffff) { *olp = *nlp; return 0; } if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC || dkcksum(nlp) != 0) return EINVAL; /* XXX missing check if other dos partitions will be overwritten */ while (openmask != 0) { i = ffs(openmask) - 1; openmask &= ~(1 << i); if (nlp->d_npartitions <= i) return EBUSY; opp = &olp->d_partitions[i]; npp = &nlp->d_partitions[i]; if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size) return EBUSY; /* * Copy internally-set partition information * if new label doesn't include it. XXX */ if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) { npp->p_fstype = opp->p_fstype; npp->p_fsize = opp->p_fsize; npp->p_frag = opp->p_frag; npp->p_cpg = opp->p_cpg; } } nlp->d_checksum = 0; nlp->d_checksum = dkcksum(nlp); *olp = *nlp; return 0; } /* * Write disk label back to device after modification. */ int writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, struct cpu_disklabel *osdep) { struct mbr_partition *dp; struct buf *bp; struct disklabel *dlp; int error, dospartoff, cyl; /* get a buffer and initialize it */ bp = geteblk((int)lp->d_secsize); bp->b_dev = dev; /* do dos partitions in the process of getting disklabel? */ dospartoff = 0; cyl = LABELSECTOR / lp->d_secpercyl; if (!osdep) goto nombrpart; dp = osdep->mbrparts; /* read master boot record */ bp->b_blkno = MBR_BBSECTOR; bp->b_bcount = lp->d_secsize; bp->b_flags |= B_READ; bp->b_cylinder = MBR_BBSECTOR / lp->d_secpercyl; (*strat)(bp); if ((error = biowait(bp)) == 0) { struct mbr_partition *ourdp = NULL; ourdp = mbr_findslice(dp, bp); if (ourdp == NO_MBR_SIGNATURE) goto nombrpart; if (ourdp) { /* need sector address for SCSI/IDE, cylinder for ESDI/ST506/RLL */ dospartoff = ourdp->mbrp_start; cyl = MBR_PCYL(ourdp->mbrp_scyl, ourdp->mbrp_ssect); } } nombrpart: /* next, dig out disk label */ bp->b_blkno = dospartoff + LABELSECTOR; bp->b_cylinder = cyl; bp->b_bcount = lp->d_secsize; bp->b_oflags &= ~(BO_DONE); bp->b_flags |= B_READ; (*strat)(bp); /* if successful, locate disk label within block and validate */ if ((error = biowait(bp)) != 0) goto done; for (dlp = (struct disklabel *)bp->b_data; dlp <= (struct disklabel *)((char *)bp->b_data + lp->d_secsize - sizeof(*dlp)); dlp = (struct disklabel *)((char *)dlp + sizeof(long))) { if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC && dkcksum(dlp) == 0) { *dlp = *lp; bp->b_oflags &= ~(BO_DONE); bp->b_flags &= ~(B_READ); bp->b_flags |= B_WRITE; (*strat)(bp); error = biowait(bp); goto done; } } error = ESRCH; done: brelse(bp, 0); return error; }