/* * 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. */ 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; 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->dosparts; /* 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 < NMBRPART; 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; if (dp->mbrp_typ == MBR_PTYPE_LNXEXT2) pp->p_fstype = FS_EX2FS; if (dp->mbrp_typ == MBR_PTYPE_LNXSWAP) pp->p_fstype = FS_SWAP; /* 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_flags &= ~(B_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 *)(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_flags &= ~(B_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_flags & B_ERROR) && (i += 2) < 10 && i < lp->d_nsectors); } done: brelse(bp); return (msg); }
/* * 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 = le32toh(ourdp->mbrp_start); cyl = MBR_PCYL(ourdp->mbrp_scyl, ourdp->mbrp_ssect); } } nombrpart: #ifdef maybe /* disklabel in appropriate location? */ if (lp->d_partitions[2].p_offset != 0 && lp->d_partitions[2].p_offset != dospartoff) { error = EXDEV; goto done; } #endif /* 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 && dlp->d_npartitions <= MAXPARTITIONS && dkcksum(dlp) == 0) { /* found disklabel in host's endian */ *dlp = *lp; goto found; #ifdef BSDDISKLABEL_EI } else if (bswap32(dlp->d_magic) == DISKMAGIC && bswap32(dlp->d_magic2) == DISKMAGIC && bswap16(dlp->d_npartitions) <= MAXPARTITIONS && dkcksum_re(dlp) == 0) { /* found disklabel in the opposite endian */ swap_endian_disklabel(dlp, lp); /* recalculate cksum in reversed endian */ dlp->d_checksum = 0; dlp->d_checksum = dkcksum_re(dlp); goto found; #endif #ifdef COMPAT_MMEYE_OLDLABEL } else if (le32toh(dlp->d_magic) == DISKMAGIC && le32toh(dlp->d_magic2) == DISKMAGIC && le16toh(dlp->d_npartitions) <= MAXPARTITIONS && dkcksum_mmeye(dlp) == 0) { /* found disklabel by old mmeye's rule */ swap_mmeye_disklabel(dlp, lp); /* recalculate cksum for it */ dlp->d_checksum = 0; dlp->d_checksum = dkcksum_mmeye(dlp); goto found; #endif } } /* No valid disklabel found on disk */ error = ESRCH; goto done; found: bp->b_oflags &= ~(BO_DONE); bp->b_flags &= ~(B_READ); bp->b_flags |= B_WRITE; (*strat)(bp); error = biowait(bp); done: brelse(bp, 0); return (error); }
/* * 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->dosparts; /* 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_flags &= ~(B_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 *)(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_flags &= ~(B_READ|B_DONE); bp->b_flags |= B_WRITE; (*strat)(bp); error = biowait(bp); goto done; } } error = ESRCH; done: brelse(bp); return (error); }
/* * 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, *ip; /* 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 = le32toh(dp->mbrp_start); pp->p_size = le32toh(dp->mbrp_size); for (ip = fat_types; *ip != -1; ip++) { if (dp->mbrp_type == *ip) pp->p_fstype = FS_MSDOS; } if (dp->mbrp_type == MBR_PTYPE_LNXEXT2) pp->p_fstype = FS_EX2FS; if (dp->mbrp_type == MBR_PTYPE_NTFS) pp->p_fstype = FS_NTFS; /* is this ours? */ if (dp == ourdp) { /* need sector address for SCSI/IDE, cylinder for ESDI/ST506/RLL */ dospartoff = le32toh(dp->mbrp_start); cyl = MBR_PCYL(dp->mbrp_scyl, dp->mbrp_ssect); /* update disklabel with details */ lp->d_partitions[2].p_size = le32toh(dp->mbrp_size); lp->d_partitions[2].p_offset = le32toh(dp->mbrp_start); #if 0 if (lp->d_ntracks != dp->mbrp_ehd + 1 || lp->d_nsectors != MBR_PSECT(dp->mbrp_esect)) { printf("disklabel: BIOS sees chs %d/%d/%d as ", lp->d_ncylinders, lp->d_ntracks, lp->d_nsectors); lp->d_ntracks = dp->mbrp_ehd + 1; lp->d_nsectors = MBR_PSECT(dp->mbrp_esect); lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors; lp->d_ncylinders = lp->d_secperunit / lp->d_secpercyl; if (! lp->d_ncylinders) lp->d_ncylinders = 1; printf("%d/%d/%d\n", lp->d_ncylinders, lp->d_ntracks, lp->d_nsectors); } #endif } } 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) { /* disklabel is written in host's endian */ if (dlp->d_npartitions > MAXPARTITIONS || dkcksum(dlp) != 0) msg = "disk label corruptted"; else { *lp = *dlp; msg = NULL; break; } } #ifdef BSDDISKLABEL_EI if (bswap32(dlp->d_magic) == DISKMAGIC && bswap32(dlp->d_magic2) == DISKMAGIC) { /* disklabel is written in reversed endian */ if (bswap16(dlp->d_npartitions) > MAXPARTITIONS || dkcksum_re(dlp) != 0) msg = "disk label corruptted"; else { swap_endian_disklabel(lp, dlp); /* recalculate cksum in host's endian */ lp->d_checksum = 0; lp->d_checksum = dkcksum(lp); msg = NULL; break; } } #endif #ifdef COMPAT_MMEYE_OLDLABEL if (le32toh(dlp->d_magic) == DISKMAGIC && le32toh(dlp->d_magic2) == DISKMAGIC) { if (le16toh(dlp->d_npartitions) > MAXPARTITIONS || dkcksum_mmeye(dlp) != 0) msg = "disk label corruptted"; else { /* disklabel is written in old mmeye's way */ swap_mmeye_disklabel(lp, dlp); /* recalculate cksum in host's endian */ lp->d_checksum = 0; lp->d_checksum = dkcksum(lp); msg = NULL; break; } } #endif if (msg == NULL) msg = "no disk label"; } 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); }