/* * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. * * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94 * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include /* * 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 in the strategy routine (e.g., dummy bounds for the * partition containing the label) must be filled in before calling us. * Returns NULL on success and an error string on failure. */ char * readdisklabel(dev, lp) dev_t dev; register struct disklabel *lp; { register struct buf *bp; struct disklabel *dlp; char *msg = NULL; bp = geteblk((int)lp->d_secsize); bp->b_dev = dev; bp->b_blkno = LABELSECTOR * ((int)lp->d_secsize/DEV_BSIZE); bp->b_bcount = lp->d_secsize; bp->b_flags &= ~B_INVAL; bp->b_iocmd = BIO_READ; DEV_STRATEGY(bp); if (bufwait(bp)) msg = "I/O error"; else if (bp->b_resid != 0) msg = "disk too small for a label"; else 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; } } bp->b_flags |= B_INVAL | B_AGE; brelse(bp); return (msg); } /* * Check new disk label for sensibility before setting it. */ int setdisklabel(olp, nlp, openmask) register struct disklabel *olp, *nlp; u_long openmask; { register int i; register struct partition *opp, *npp; /* * Check it is actually a disklabel we are looking at. */ if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC || dkcksum(nlp) != 0) return (EINVAL); /* * For each partition that we think is open, */ while ((i = ffs((long)openmask)) != 0) { i--; /* * Check it is not changing.... */ 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 we are using it then we had better stay the same type) * This is possibly dubious, as someone else noted (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, lp) dev_t dev; register struct disklabel *lp; { struct buf *bp; struct disklabel *dlp; int error = 0; if (lp->d_partitions[RAW_PART].p_offset != 0) return (EXDEV); /* not quite right */ bp = geteblk((int)lp->d_secsize); bp->b_dev = dkmodpart(dev, RAW_PART); bp->b_blkno = LABELSECTOR * ((int)lp->d_secsize/DEV_BSIZE); bp->b_bcount = lp->d_secsize; #if 1 /* * We read the label first to see if it's there, * in which case we will put ours at the same offset into the block.. * (I think this is stupid [Julian]) * Note that you can't write a label out over a corrupted label! * (also stupid.. how do you write the first one? by raw writes?) */ bp->b_flags &= ~B_INVAL; bp->b_iocmd = BIO_READ; DEV_STRATEGY(bp); error = bufwait(bp); if (error) goto done; if (bp->b_resid != 0) { error = ENOSPC; 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_flags &= ~B_DONE; bp->b_iocmd = BIO_WRITE; #ifdef __alpha__ alpha_fix_srm_checksum(bp); #endif DEV_STRATEGY(bp); error = bufwait(bp); goto done; } } error = ESRCH; done: #else bzero(bp->b_data, lp->d_secsize); dlp = (struct disklabel *)bp->b_data; *dlp = *lp; bp->b_flags &= ~B_INVAL; bp->b_iocmd = BIO_WRITE; DEV_STRATEGY(bp); error = bufwait(bp); #endif bp->b_flags |= B_INVAL | B_AGE; brelse(bp); return (error); } /* * Determine the size of the transfer, and make sure it is * within the boundaries of the partition. Adjust transfer * if needed, and signal errors or early completion. */ int bounds_check_with_label(struct bio *bp, struct disklabel *lp, int wlabel) { struct partition *p = lp->d_partitions + dkpart(bp->bio_dev); int labelsect = lp->d_partitions[0].p_offset; int maxsz = p->p_size, sz = (bp->bio_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* overwriting disk label ? */ /* XXX should also protect bootstrap in first 8K */ if (bp->bio_blkno + p->p_offset <= LABELSECTOR + labelsect && #if LABELSECTOR != 0 bp->bio_blkno + p->p_offset + sz > LABELSECTOR + labelsect && #endif (bp->bio_cmd == BIO_WRITE) && wlabel == 0) { bp->bio_error = EROFS; goto bad; } #if defined(DOSBBSECTOR) && defined(notyet) /* overwriting master boot record? */ if (bp->bio_blkno + p->p_offset <= DOSBBSECTOR && (bp->bio_cmd == BIO_WRITE) && wlabel == 0) { bp->bio_error = EROFS; goto bad; } #endif /* beyond partition? */ if (bp->bio_blkno < 0 || bp->bio_blkno + sz > maxsz) { /* if exactly at end of disk, return an EOF */ if (bp->bio_blkno == maxsz) { bp->bio_resid = bp->bio_bcount; return(0); } /* or truncate if part of it fits */ sz = maxsz - bp->bio_blkno; if (sz <= 0) { bp->bio_error = EINVAL; goto bad; } bp->bio_bcount = sz << DEV_BSHIFT; } bp->bio_pblkno = bp->bio_blkno + p->p_offset; return(1); bad: bp->bio_flags |= BIO_ERROR; return(-1); }