diff options
Diffstat (limited to 'sys/kern/subr_disklabel.c')
| -rw-r--r-- | sys/kern/subr_disklabel.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/sys/kern/subr_disklabel.c b/sys/kern/subr_disklabel.c new file mode 100644 index 0000000..33f1d2a --- /dev/null +++ b/sys/kern/subr_disklabel.c @@ -0,0 +1,410 @@ +/* + * 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 + * $Id: ufs_disksubr.c,v 1.38 1998/10/17 07:49:04 bde Exp $ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/buf.h> +#include <sys/conf.h> +#include <sys/disklabel.h> +#include <sys/diskslice.h> +#include <sys/syslog.h> + +/* + * Seek sort for disks. + * + * The buf_queue keep two queues, sorted in ascending block order. The first + * queue holds those requests which are positioned after the current block + * (in the first request); the second, which starts at queue->switch_point, + * holds requests which came in after their block 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. + */ + +void +bufqdisksort(bufq, bp) + struct buf_queue_head *bufq; + struct buf *bp; +{ + struct buf *bq; + struct buf *bn; + struct buf *be; + + be = TAILQ_LAST(&bufq->queue, buf_queue); + /* + * If the queue is empty or we are an + * ordered transaction, then it's easy. + */ + if ((bq = bufq_first(bufq)) == NULL + || (bp->b_flags & B_ORDERED) != 0) { + bufq_insert_tail(bufq, bp); + return; + } else if (bufq->insert_point != NULL) { + + /* + * A certain portion of the list is + * "locked" to preserve ordering, so + * we can only insert after the insert + * point. + */ + bq = bufq->insert_point; + } else { + + /* + * If we lie before the last removed (currently active) + * request, and are not inserting ourselves into the + * "locked" portion of the list, then we must add ourselves + * to the second request list. + */ + if (bp->b_pblkno < bufq->last_pblkno) { + + bq = bufq->switch_point; + /* + * If we are starting a new secondary list, + * then it's easy. + */ + if (bq == NULL) { + bufq->switch_point = bp; + bufq_insert_tail(bufq, bp); + return; + } + /* + * If we lie ahead of the current switch point, + * insert us before the switch point and move + * the switch point. + */ + if (bp->b_pblkno < bq->b_pblkno) { + bufq->switch_point = bp; + TAILQ_INSERT_BEFORE(bq, bp, b_act); + return; + } + } else { + if (bufq->switch_point != NULL) + be = TAILQ_PREV(bufq->switch_point, + buf_queue, b_act); + /* + * If we lie between last_pblkno and bq, + * insert before bq. + */ + if (bp->b_pblkno < bq->b_pblkno) { + TAILQ_INSERT_BEFORE(bq, bp, b_act); + return; + } + } + } + + /* + * Request is at/after our current position in the list. + * Optimize for sequential I/O by seeing if we go at the tail. + */ + if (bp->b_pblkno > be->b_pblkno) { + TAILQ_INSERT_AFTER(&bufq->queue, be, bp, b_act); + return; + } + + /* Otherwise, insertion sort */ + while ((bn = TAILQ_NEXT(bq, b_act)) != NULL) { + + /* + * We want to go after the current request if it is the end + * of the first request list, or if the next request is a + * larger cylinder than our request. + */ + if (bn == bufq->switch_point + || bp->b_pblkno < bn->b_pblkno) + break; + bq = bn; + } + TAILQ_INSERT_AFTER(&bufq->queue, bq, bp, b_act); +} + + +/* + * 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, strat, lp) + dev_t dev; + d_strategy_t *strat; + 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_flags |= B_BUSY | B_READ; + (*strat)(bp); + if (biowait(bp)) + msg = "I/O error"; + 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, strat, lp) + dev_t dev; + d_strategy_t *strat; + 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_flags |= B_BUSY | B_READ; + (*strat)(bp); + error = biowait(bp); + if (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 && + dkcksum(dlp) == 0) { + *dlp = *lp; + bp->b_flags &= ~(B_DONE | B_READ); + bp->b_flags |= B_BUSY | B_WRITE; +#ifdef __alpha__ + alpha_fix_srm_checksum(bp); +#endif + (*strat)(bp); + error = biowait(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_flags |= B_BUSY | B_WRITE; + (*strat)(bp); + error = biowait(bp); +#endif + bp->b_flags |= B_INVAL | B_AGE; + brelse(bp); + return (error); +} + +/* + * Compute checksum for disk label. + */ +u_int +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); + int slice = dkslice(bp->b_dev); + int part = dkpart(bp->b_dev); + register int (*pr) __P((const char *, ...)); + char partname[2]; + char *sname; + daddr_t sn; + + if (pri != LOG_PRINTF) { + log(pri, "%s", ""); + pr = addlog; + } else + pr = printf; + sname = dsname(dname, unit, slice, part, partname); + (*pr)("%s%s: %s %sing fsbn ", sname, partname, what, + bp->b_flags & B_READ ? "read" : "writ"); + sn = bp->b_blkno; + if (bp->b_bcount <= DEV_BSIZE) + (*pr)("%ld", (long)sn); + else { + if (blkdone >= 0) { + sn += blkdone; + (*pr)("%ld of ", (long)sn); + } + (*pr)("%ld-%ld", (long)bp->b_blkno, + (long)(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; + /* + * XXX should add slice offset and not print the slice, + * but we don't know the slice pointer. + * XXX should print bp->b_pblkno so that this will work + * independent of slices, labels and bad sector remapping, + * but some drivers don't set bp->b_pblkno. + */ + (*pr)(" (%s bn %ld; cn %ld", sname, (long)sn, + (long)(sn / lp->d_secpercyl)); + sn %= (long)lp->d_secpercyl; + (*pr)(" tn %ld sn %ld)", (long)(sn / lp->d_nsectors), + (long)(sn % lp->d_nsectors)); + } +} |
