/* * 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. 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 7.16 (Berkeley) 5/4/91 */ #include "param.h" #include "systm.h" #include "buf.h" #include "disklabel.h" #include "syslog.h" /* * Seek sort for disks. We depend on the driver * which calls us using b_resid as the current cylinder number. * * The argument dp 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. */ #define b_cylin b_resid disksort(dp, bp) register struct buf *dp, *bp; { register struct buf *ap; /* * If nothing on the activity queue, then * we become the only thing. */ ap = dp->b_actf; if(ap == NULL) { dp->b_actf = bp; dp->b_actl = bp; bp->av_forw = NULL; return; } /* * If we lie after the first (currently active) * request, then we must locate the second request list * and add ourselves to it. */ if (bp->b_cylin < ap->b_cylin) { while (ap->av_forw) { /* * Check for an ``inversion'' in the * normally ascending cylinder numbers, * indicating the start of the second request list. */ if (ap->av_forw->b_cylin < ap->b_cylin) { /* * 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_cylin < ap->av_forw->b_cylin) goto insert; if (bp->b_cylin == ap->av_forw->b_cylin && bp->b_blkno < ap->av_forw->b_blkno) goto insert; ap = ap->av_forw; } while (ap->av_forw); goto insert; /* after last */ } ap = ap->av_forw; } /* * 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 (ap->av_forw) { /* * 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 (ap->av_forw->b_cylin < ap->b_cylin || bp->b_cylin < ap->av_forw->b_cylin || (bp->b_cylin == ap->av_forw->b_cylin && bp->b_blkno < ap->av_forw->b_blkno)) goto insert; ap = ap->av_forw; } /* * 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->av_forw = ap->av_forw; ap->av_forw = bp; if (ap == dp->b_actl) dp->b_actl = 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_cylin = LABELSECTOR / lp->d_secpercyl; (*strat)(bp); if (biowait(bp)) { msg = "I/O error"; } else for (dlp = (struct disklabel *)bp->b_un.b_addr; dlp <= (struct disklabel *)(bp->b_un.b_addr+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. */ 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. */ 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_un.b_addr; dlp <= (struct disklabel *) (bp->b_un.b_addr + 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. */ 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); } }