diff options
Diffstat (limited to 'sys/kern/subr_disklabel.c')
| -rw-r--r-- | sys/kern/subr_disklabel.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/sys/kern/subr_disklabel.c b/sys/kern/subr_disklabel.c new file mode 100644 index 0000000..78dede4 --- /dev/null +++ b/sys/kern/subr_disklabel.c @@ -0,0 +1,364 @@ +/* + * 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 + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/buf.h> +#include <sys/disklabel.h> +#include <sys/syslog.h> + +/* + * Seek sort for disks. We depend on the driver which calls us using b_resid + * as the current cylinder number. + * + * The argument ap structure holds a b_actf activity chain pointer on which we + * keep two queues, sorted in ascending cylinder order. The first queue holds + * those requests which are positioned after the current cylinder (in the first + * request); the second holds requests which came in after their cylinder number + * was passed. Thus we implement a one way scan, retracting after reaching the + * end of the drive to the first request on the second queue, at which time it + * becomes the first queue. + * + * A one-way scan is natural because of the way UNIX read-ahead blocks are + * allocated. + */ + +/* + * For portability with historic industry practice, the + * cylinder number has to be maintained in the `b_resid' + * field. + */ +#define b_cylinder b_resid + +void +disksort(ap, bp) + register struct buf *ap, *bp; +{ + register struct buf *bq; + + /* If the queue is empty, then it's easy. */ + if (ap->b_actf == NULL) { + bp->b_actf = NULL; + ap->b_actf = bp; + return; + } + + /* + * If we lie after the first (currently active) request, then we + * must locate the second request list and add ourselves to it. + */ + bq = ap->b_actf; + if (bp->b_cylinder < bq->b_cylinder) { + while (bq->b_actf) { + /* + * Check for an ``inversion'' in the normally ascending + * cylinder numbers, indicating the start of the second + * request list. + */ + if (bq->b_actf->b_cylinder < bq->b_cylinder) { + /* + * Search the second request list for the first + * request at a larger cylinder number. We go + * before that; if there is no such request, we + * go at end. + */ + do { + if (bp->b_cylinder < + bq->b_actf->b_cylinder) + goto insert; + if (bp->b_cylinder == + bq->b_actf->b_cylinder && + bp->b_blkno < bq->b_actf->b_blkno) + goto insert; + bq = bq->b_actf; + } while (bq->b_actf); + goto insert; /* after last */ + } + bq = bq->b_actf; + } + /* + * No inversions... we will go after the last, and + * be the first request in the second request list. + */ + goto insert; + } + /* + * Request is at/after the current request... + * sort in the first request list. + */ + while (bq->b_actf) { + /* + * We want to go after the current request if there is an + * inversion after it (i.e. it is the end of the first + * request list), or if the next request is a larger cylinder + * than our request. + */ + if (bq->b_actf->b_cylinder < bq->b_cylinder || + bp->b_cylinder < bq->b_actf->b_cylinder || + (bp->b_cylinder == bq->b_actf->b_cylinder && + bp->b_blkno < bq->b_actf->b_blkno)) + goto insert; + bq = bq->b_actf; + } + /* + * Neither a second list nor a larger request... we go at the end of + * the first list, which is the same as the end of the whole schebang. + */ +insert: bp->b_actf = bq->b_actf; + bq->b_actf = bp; +} + +/* + * Attempt to read a disk label from a device using the indicated stategy + * routine. The label must be partly set up before this: secpercyl and + * anything required in the strategy routine (e.g., sector size) must be + * filled in before calling us. Returns NULL on success and an error + * string on failure. + */ +char * +readdisklabel(dev, strat, lp) + dev_t dev; + int (*strat)(); + register struct disklabel *lp; +{ + register struct buf *bp; + struct disklabel *dlp; + char *msg = NULL; + + if (lp->d_secperunit == 0) + lp->d_secperunit = 0x1fffffff; + lp->d_npartitions = 1; + if (lp->d_partitions[0].p_size == 0) + lp->d_partitions[0].p_size = 0x1fffffff; + lp->d_partitions[0].p_offset = 0; + + bp = geteblk((int)lp->d_secsize); + bp->b_dev = dev; + bp->b_blkno = LABELSECTOR; + bp->b_bcount = lp->d_secsize; + bp->b_flags = B_BUSY | B_READ; + bp->b_cylinder = LABELSECTOR / lp->d_secpercyl; + (*strat)(bp); + if (biowait(bp)) + msg = "I/O error"; + else for (dlp = (struct disklabel *)bp->b_data; + dlp <= (struct disklabel *)((char *)bp->b_data + + DEV_BSIZE - 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 i; + register struct partition *opp, *npp; + + if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC || + dkcksum(nlp) != 0) + return (EINVAL); + while ((i = ffs((long)openmask)) != 0) { + i--; + 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); +} + +/* encoding of disk minor numbers, should be elsewhere... */ +#define dkunit(dev) (minor(dev) >> 3) +#define dkpart(dev) (minor(dev) & 07) +#define dkminor(unit, part) (((unit) << 3) | (part)) + +/* + * Write disk label back to device after modification. + */ +int +writedisklabel(dev, strat, lp) + dev_t dev; + int (*strat)(); + register struct disklabel *lp; +{ + struct buf *bp; + struct disklabel *dlp; + int labelpart; + int error = 0; + + labelpart = dkpart(dev); + if (lp->d_partitions[labelpart].p_offset != 0) { + if (lp->d_partitions[0].p_offset != 0) + return (EXDEV); /* not quite right */ + labelpart = 0; + } + bp = geteblk((int)lp->d_secsize); + bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), labelpart)); + bp->b_blkno = LABELSECTOR; + bp->b_bcount = lp->d_secsize; + bp->b_flags = B_READ; + (*strat)(bp); + if (error = biowait(bp)) + 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_WRITE; + (*strat)(bp); + error = biowait(bp); + goto done; + } + } + error = ESRCH; +done: + brelse(bp); + return (error); +} + +/* + * Compute checksum for disk label. + */ +dkcksum(lp) + register struct disklabel *lp; +{ + register u_short *start, *end; + register u_short sum = 0; + + start = (u_short *)lp; + end = (u_short *)&lp->d_partitions[lp->d_npartitions]; + while (start < end) + sum ^= *start++; + return (sum); +} + +/* + * Disk error is the preface to plaintive error messages + * about failing disk transfers. It prints messages of the form + +hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d) + + * if the offset of the error in the transfer and a disk label + * are both available. blkdone should be -1 if the position of the error + * is unknown; the disklabel pointer may be null from drivers that have not + * been converted to use them. The message is printed with printf + * if pri is LOG_PRINTF, otherwise it uses log at the specified priority. + * The message should be completed (with at least a newline) with printf + * or addlog, respectively. There is no trailing space. + */ +void +diskerr(bp, dname, what, pri, blkdone, lp) + register struct buf *bp; + char *dname, *what; + int pri, blkdone; + register struct disklabel *lp; +{ + int unit = dkunit(bp->b_dev), part = dkpart(bp->b_dev); + register void (*pr) __P((const char *, ...)); + char partname = 'a' + part; + int sn; + + if (pri != LOG_PRINTF) { + log(pri, ""); + pr = addlog; + } else + pr = printf; + (*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what, + bp->b_flags & B_READ ? "read" : "writ"); + sn = bp->b_blkno; + if (bp->b_bcount <= DEV_BSIZE) + (*pr)("%d", sn); + else { + if (blkdone >= 0) { + sn += blkdone; + (*pr)("%d of ", sn); + } + (*pr)("%d-%d", bp->b_blkno, + bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE); + } + if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) { +#ifdef tahoe + sn *= DEV_BSIZE / lp->d_secsize; /* XXX */ +#endif + sn += lp->d_partitions[part].p_offset; + (*pr)(" (%s%d bn %d; cn %d", dname, unit, sn, + sn / lp->d_secpercyl); + sn %= lp->d_secpercyl; + (*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors); + } +} |
