1 /* $NetBSD: subr_disk.c,v 1.13 1995/03/29 20:57:35 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/buf.h> 46 #include <sys/disklabel.h> 47 #include <sys/syslog.h> 48 49 /* 50 * Seek sort for disks. We depend on the driver which calls us using b_resid 51 * as the current cylinder number. 52 * 53 * The argument ap structure holds a b_actf activity chain pointer on which we 54 * keep two queues, sorted in ascending cylinder order. The first queue holds 55 * those requests which are positioned after the current cylinder (in the first 56 * request); the second holds requests which came in after their cylinder number 57 * was passed. Thus we implement a one way scan, retracting after reaching the 58 * end of the drive to the first request on the second queue, at which time it 59 * becomes the first queue. 60 * 61 * A one-way scan is natural because of the way UNIX read-ahead blocks are 62 * allocated. 63 */ 64 65 void 66 disksort(ap, bp) 67 register struct buf *ap, *bp; 68 { 69 register struct buf *bq; 70 71 /* If the queue is empty, then it's easy. */ 72 if (ap->b_actf == NULL) { 73 bp->b_actf = NULL; 74 ap->b_actf = bp; 75 return; 76 } 77 78 /* 79 * If we lie after the first (currently active) request, then we 80 * must locate the second request list and add ourselves to it. 81 */ 82 bq = ap->b_actf; 83 if (bp->b_cylinder < bq->b_cylinder) { 84 while (bq->b_actf) { 85 /* 86 * Check for an ``inversion'' in the normally ascending 87 * cylinder numbers, indicating the start of the second 88 * request list. 89 */ 90 if (bq->b_actf->b_cylinder < bq->b_cylinder) { 91 /* 92 * Search the second request list for the first 93 * request at a larger cylinder number. We go 94 * before that; if there is no such request, we 95 * go at end. 96 */ 97 do { 98 if (bp->b_cylinder < 99 bq->b_actf->b_cylinder) 100 goto insert; 101 if (bp->b_cylinder == 102 bq->b_actf->b_cylinder && 103 bp->b_blkno < bq->b_actf->b_blkno) 104 goto insert; 105 bq = bq->b_actf; 106 } while (bq->b_actf); 107 goto insert; /* after last */ 108 } 109 bq = bq->b_actf; 110 } 111 /* 112 * No inversions... we will go after the last, and 113 * be the first request in the second request list. 114 */ 115 goto insert; 116 } 117 /* 118 * Request is at/after the current request... 119 * sort in the first request list. 120 */ 121 while (bq->b_actf) { 122 /* 123 * We want to go after the current request if there is an 124 * inversion after it (i.e. it is the end of the first 125 * request list), or if the next request is a larger cylinder 126 * than our request. 127 */ 128 if (bq->b_actf->b_cylinder < bq->b_cylinder || 129 bp->b_cylinder < bq->b_actf->b_cylinder || 130 (bp->b_cylinder == bq->b_actf->b_cylinder && 131 bp->b_blkno < bq->b_actf->b_blkno)) 132 goto insert; 133 bq = bq->b_actf; 134 } 135 /* 136 * Neither a second list nor a larger request... we go at the end of 137 * the first list, which is the same as the end of the whole schebang. 138 */ 139 insert: bp->b_actf = bq->b_actf; 140 bq->b_actf = bp; 141 } 142 143 /* encoding of disk minor numbers, should be elsewhere... */ 144 #define dkunit(dev) (minor(dev) >> 3) 145 #define dkpart(dev) (minor(dev) & 07) 146 #define dkminor(unit, part) (((unit) << 3) | (part)) 147 148 /* 149 * Compute checksum for disk label. 150 */ 151 u_int 152 dkcksum(lp) 153 register struct disklabel *lp; 154 { 155 register u_short *start, *end; 156 register u_short sum = 0; 157 158 start = (u_short *)lp; 159 end = (u_short *)&lp->d_partitions[lp->d_npartitions]; 160 while (start < end) 161 sum ^= *start++; 162 return (sum); 163 } 164 165 /* 166 * Disk error is the preface to plaintive error messages 167 * about failing disk transfers. It prints messages of the form 168 169 hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d) 170 171 * if the offset of the error in the transfer and a disk label 172 * are both available. blkdone should be -1 if the position of the error 173 * is unknown; the disklabel pointer may be null from drivers that have not 174 * been converted to use them. The message is printed with printf 175 * if pri is LOG_PRINTF, otherwise it uses log at the specified priority. 176 * The message should be completed (with at least a newline) with printf 177 * or addlog, respectively. There is no trailing space. 178 */ 179 void 180 diskerr(bp, dname, what, pri, blkdone, lp) 181 register struct buf *bp; 182 char *dname, *what; 183 int pri, blkdone; 184 register struct disklabel *lp; 185 { 186 int unit = dkunit(bp->b_dev), part = dkpart(bp->b_dev); 187 register void (*pr) __P((const char *, ...)); 188 char partname = 'a' + part; 189 int sn; 190 191 if (pri != LOG_PRINTF) { 192 log(pri, ""); 193 pr = addlog; 194 } else 195 pr = printf; 196 (*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what, 197 bp->b_flags & B_READ ? "read" : "writ"); 198 sn = bp->b_blkno; 199 if (bp->b_bcount <= DEV_BSIZE) 200 (*pr)("%d", sn); 201 else { 202 if (blkdone >= 0) { 203 sn += blkdone; 204 (*pr)("%d of ", sn); 205 } 206 (*pr)("%d-%d", bp->b_blkno, 207 bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE); 208 } 209 if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) { 210 #ifdef tahoe 211 sn *= DEV_BSIZE / lp->d_secsize; /* XXX */ 212 #endif 213 sn += lp->d_partitions[part].p_offset; 214 (*pr)(" (%s%d bn %d; cn %d", dname, unit, sn, 215 sn / lp->d_secpercyl); 216 sn %= lp->d_secpercyl; 217 (*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors); 218 } 219 } 220