1 /* $NetBSD: subr_disk.c,v 1.30 2001/07/09 10:54:12 simonb Exp $ */ 2 3 /*- 4 * Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright (c) 1982, 1986, 1988, 1993 42 * The Regents of the University of California. All rights reserved. 43 * (c) UNIX System Laboratories, Inc. 44 * All or some portions of this file are derived from material licensed 45 * to the University of California by American Telephone and Telegraph 46 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 47 * the permission of UNIX System Laboratories, Inc. 48 * 49 * Redistribution and use in source and binary forms, with or without 50 * modification, are permitted provided that the following conditions 51 * are met: 52 * 1. Redistributions of source code must retain the above copyright 53 * notice, this list of conditions and the following disclaimer. 54 * 2. Redistributions in binary form must reproduce the above copyright 55 * notice, this list of conditions and the following disclaimer in the 56 * documentation and/or other materials provided with the distribution. 57 * 3. All advertising materials mentioning features or use of this software 58 * must display the following acknowledgement: 59 * This product includes software developed by the University of 60 * California, Berkeley and its contributors. 61 * 4. Neither the name of the University nor the names of its contributors 62 * may be used to endorse or promote products derived from this software 63 * without specific prior written permission. 64 * 65 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 66 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 67 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 68 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 69 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 70 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 71 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 72 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 73 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 74 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 75 * SUCH DAMAGE. 76 * 77 * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94 78 */ 79 80 #include <sys/param.h> 81 #include <sys/systm.h> 82 #include <sys/kernel.h> 83 #include <sys/malloc.h> 84 #include <sys/buf.h> 85 #include <sys/syslog.h> 86 #include <sys/time.h> 87 #include <sys/disklabel.h> 88 #include <sys/disk.h> 89 90 /* 91 * A global list of all disks attached to the system. May grow or 92 * shrink over time. 93 */ 94 struct disklist_head disklist; /* TAILQ_HEAD */ 95 int disk_count; /* number of drives in global disklist */ 96 97 /* 98 * Seek sort for disks. We depend on the driver which calls us using b_resid 99 * as the current cylinder number. 100 * 101 * The argument bufq is an I/O queue for the device, on which there are 102 * actually two queues, sorted in ascending cylinder order. The first 103 * queue holds those requests which are positioned after the current 104 * cylinder (in the first request); the second holds requests which came 105 * in after their cylinder number was passed. Thus we implement a one-way 106 * scan, retracting after reaching the end of the drive to the first request 107 * on the second queue, at which time it becomes the first queue. 108 * 109 * A one-way scan is natural because of the way UNIX read-ahead blocks are 110 * allocated. 111 * 112 * This is further adjusted by any `barriers' which may exist in the queue. 113 * The bufq points to the last such ordered request. 114 */ 115 void 116 disksort_cylinder(struct buf_queue *bufq, struct buf *bp) 117 { 118 struct buf *bq, *nbq; 119 120 /* 121 * If there are ordered requests on the queue, we must start 122 * the elevator sort after the last of these. 123 */ 124 if ((bq = bufq->bq_barrier) == NULL) 125 bq = BUFQ_FIRST(bufq); 126 127 /* 128 * If the queue is empty, of if it's an ordered request, 129 * it's easy; we just go on the end. 130 */ 131 if (bq == NULL || (bp->b_flags & B_ORDERED) != 0) { 132 BUFQ_INSERT_TAIL(bufq, bp); 133 return; 134 } 135 136 /* 137 * If we lie after the first (currently active) request, then we 138 * must locate the second request list and add ourselves to it. 139 */ 140 if (bp->b_cylinder < bq->b_cylinder || 141 (bp->b_cylinder == bq->b_cylinder && 142 bp->b_rawblkno < bq->b_rawblkno)) { 143 while ((nbq = BUFQ_NEXT(bq)) != NULL) { 144 /* 145 * Check for an ``inversion'' in the normally ascending 146 * cylinder numbers, indicating the start of the second 147 * request list. 148 */ 149 if (nbq->b_cylinder < bq->b_cylinder) { 150 /* 151 * Search the second request list for the first 152 * request at a larger cylinder number. We go 153 * before that; if there is no such request, we 154 * go at end. 155 */ 156 do { 157 if (bp->b_cylinder < nbq->b_cylinder) 158 goto insert; 159 if (bp->b_cylinder == nbq->b_cylinder && 160 bp->b_rawblkno < nbq->b_rawblkno) 161 goto insert; 162 bq = nbq; 163 } while ((nbq = BUFQ_NEXT(bq)) != NULL); 164 goto insert; /* after last */ 165 } 166 bq = BUFQ_NEXT(bq); 167 } 168 /* 169 * No inversions... we will go after the last, and 170 * be the first request in the second request list. 171 */ 172 goto insert; 173 } 174 /* 175 * Request is at/after the current request... 176 * sort in the first request list. 177 */ 178 while ((nbq = BUFQ_NEXT(bq)) != NULL) { 179 /* 180 * We want to go after the current request if there is an 181 * inversion after it (i.e. it is the end of the first 182 * request list), or if the next request is a larger cylinder 183 * than our request. 184 */ 185 if (nbq->b_cylinder < bq->b_cylinder || 186 bp->b_cylinder < nbq->b_cylinder || 187 (bp->b_cylinder == nbq->b_cylinder && 188 bp->b_rawblkno < nbq->b_rawblkno)) 189 goto insert; 190 bq = nbq; 191 } 192 /* 193 * Neither a second list nor a larger request... we go at the end of 194 * the first list, which is the same as the end of the whole schebang. 195 */ 196 insert: BUFQ_INSERT_AFTER(bufq, bq, bp); 197 } 198 199 /* 200 * Seek sort for disks. This version sorts based on b_rawblkno, which 201 * indicates the block number. 202 * 203 * As before, there are actually two queues, sorted in ascendening block 204 * order. The first queue holds those requests which are positioned after 205 * the current block (in the first request); the second holds requests which 206 * came in after their block number was passed. Thus we implement a one-way 207 * scan, retracting after reaching the end of the driver to the first request 208 * on the second queue, at which time it becomes the first queue. 209 * 210 * A one-way scan is natural because of the way UNIX read-ahead blocks are 211 * allocated. 212 * 213 * This is further adjusted by any `barriers' which may exist in the queue. 214 * The bufq points to the last such ordered request. 215 */ 216 void 217 disksort_blkno(struct buf_queue *bufq, struct buf *bp) 218 { 219 struct buf *bq, *nbq; 220 221 /* 222 * If there are ordered requests on the queue, we must start 223 * the elevator sort after the last of these. 224 */ 225 if ((bq = bufq->bq_barrier) == NULL) 226 bq = BUFQ_FIRST(bufq); 227 228 /* 229 * If the queue is empty, or if it's an ordered request, 230 * it's easy; we just go on the end. 231 */ 232 if (bq == NULL || (bp->b_flags & B_ORDERED) != 0) { 233 BUFQ_INSERT_TAIL(bufq, bp); 234 return; 235 } 236 237 /* 238 * If we lie after the first (currently active) request, then we 239 * must locate the second request list and add ourselves to it. 240 */ 241 if (bp->b_rawblkno < bq->b_rawblkno) { 242 while ((nbq = BUFQ_NEXT(bq)) != NULL) { 243 /* 244 * Check for an ``inversion'' in the normally ascending 245 * block numbers, indicating the start of the second 246 * request list. 247 */ 248 if (nbq->b_rawblkno < bq->b_rawblkno) { 249 /* 250 * Search the second request list for the first 251 * request at a larger block number. We go 252 * after that; if there is no such request, we 253 * go at the end. 254 */ 255 do { 256 if (bp->b_rawblkno < nbq->b_rawblkno) 257 goto insert; 258 bq = nbq; 259 } while ((nbq = BUFQ_NEXT(bq)) != NULL); 260 goto insert; /* after last */ 261 } 262 bq = BUFQ_NEXT(bq); 263 } 264 /* 265 * No inversions... we will go after the last, and 266 * be the first request in the second request list. 267 */ 268 goto insert; 269 } 270 /* 271 * Request is at/after the current request... 272 * sort in the first request list. 273 */ 274 while ((nbq = BUFQ_NEXT(bq)) != NULL) { 275 /* 276 * We want to go after the current request if there is an 277 * inversion after it (i.e. it is the end of the first 278 * request list), or if the next request is a larger cylinder 279 * than our request. 280 */ 281 if (nbq->b_rawblkno < bq->b_rawblkno || 282 bp->b_rawblkno < nbq->b_rawblkno) 283 goto insert; 284 bq = nbq; 285 } 286 /* 287 * Neither a second list nor a larger request... we go at the end of 288 * the first list, which is the same as the end of the whole schebang. 289 */ 290 insert: BUFQ_INSERT_AFTER(bufq, bq, bp); 291 } 292 293 /* 294 * Seek non-sort for disks. This version simply inserts requests at 295 * the tail of the queue. 296 */ 297 void 298 disksort_tail(struct buf_queue *bufq, struct buf *bp) 299 { 300 301 BUFQ_INSERT_TAIL(bufq, bp); 302 } 303 304 /* 305 * Compute checksum for disk label. 306 */ 307 u_int 308 dkcksum(struct disklabel *lp) 309 { 310 u_short *start, *end; 311 u_short sum = 0; 312 313 start = (u_short *)lp; 314 end = (u_short *)&lp->d_partitions[lp->d_npartitions]; 315 while (start < end) 316 sum ^= *start++; 317 return (sum); 318 } 319 320 /* 321 * Disk error is the preface to plaintive error messages 322 * about failing disk transfers. It prints messages of the form 323 324 hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d) 325 326 * if the offset of the error in the transfer and a disk label 327 * are both available. blkdone should be -1 if the position of the error 328 * is unknown; the disklabel pointer may be null from drivers that have not 329 * been converted to use them. The message is printed with printf 330 * if pri is LOG_PRINTF, otherwise it uses log at the specified priority. 331 * The message should be completed (with at least a newline) with printf 332 * or addlog, respectively. There is no trailing space. 333 */ 334 void 335 diskerr(struct buf *bp, char *dname, char *what, int pri, int blkdone, 336 struct disklabel *lp) 337 { 338 int unit = DISKUNIT(bp->b_dev), part = DISKPART(bp->b_dev); 339 void (*pr)(const char *, ...); 340 char partname = 'a' + part; 341 int sn; 342 343 if (pri != LOG_PRINTF) { 344 static const char fmt[] = ""; 345 log(pri, fmt); 346 pr = addlog; 347 } else 348 pr = printf; 349 (*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what, 350 bp->b_flags & B_READ ? "read" : "writ"); 351 sn = bp->b_blkno; 352 if (bp->b_bcount <= DEV_BSIZE) 353 (*pr)("%d", sn); 354 else { 355 if (blkdone >= 0) { 356 sn += blkdone; 357 (*pr)("%d of ", sn); 358 } 359 (*pr)("%d-%d", bp->b_blkno, 360 bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE); 361 } 362 if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) { 363 sn += lp->d_partitions[part].p_offset; 364 (*pr)(" (%s%d bn %d; cn %d", dname, unit, sn, 365 sn / lp->d_secpercyl); 366 sn %= lp->d_secpercyl; 367 (*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors); 368 } 369 } 370 371 /* 372 * Initialize the disklist. Called by main() before autoconfiguration. 373 */ 374 void 375 disk_init(void) 376 { 377 378 TAILQ_INIT(&disklist); 379 disk_count = 0; 380 } 381 382 /* 383 * Searches the disklist for the disk corresponding to the 384 * name provided. 385 */ 386 struct disk * 387 disk_find(char *name) 388 { 389 struct disk *diskp; 390 391 if ((name == NULL) || (disk_count <= 0)) 392 return (NULL); 393 394 for (diskp = disklist.tqh_first; diskp != NULL; 395 diskp = diskp->dk_link.tqe_next) 396 if (strcmp(diskp->dk_name, name) == 0) 397 return (diskp); 398 399 return (NULL); 400 } 401 402 /* 403 * Attach a disk. 404 */ 405 void 406 disk_attach(struct disk *diskp) 407 { 408 int s; 409 410 /* 411 * Allocate and initialize the disklabel structures. Note that 412 * it's not safe to sleep here, since we're probably going to be 413 * called during autoconfiguration. 414 */ 415 diskp->dk_label = malloc(sizeof(struct disklabel), M_DEVBUF, M_NOWAIT); 416 diskp->dk_cpulabel = malloc(sizeof(struct cpu_disklabel), M_DEVBUF, 417 M_NOWAIT); 418 if ((diskp->dk_label == NULL) || (diskp->dk_cpulabel == NULL)) 419 panic("disk_attach: can't allocate storage for disklabel"); 420 421 memset(diskp->dk_label, 0, sizeof(struct disklabel)); 422 memset(diskp->dk_cpulabel, 0, sizeof(struct cpu_disklabel)); 423 424 /* 425 * Set the attached timestamp. 426 */ 427 s = splclock(); 428 diskp->dk_attachtime = mono_time; 429 splx(s); 430 431 /* 432 * Link into the disklist. 433 */ 434 TAILQ_INSERT_TAIL(&disklist, diskp, dk_link); 435 ++disk_count; 436 } 437 438 /* 439 * Detach a disk. 440 */ 441 void 442 disk_detach(struct disk *diskp) 443 { 444 445 /* 446 * Remove from the disklist. 447 */ 448 if (--disk_count < 0) 449 panic("disk_detach: disk_count < 0"); 450 TAILQ_REMOVE(&disklist, diskp, dk_link); 451 452 /* 453 * Free the space used by the disklabel structures. 454 */ 455 free(diskp->dk_label, M_DEVBUF); 456 free(diskp->dk_cpulabel, M_DEVBUF); 457 } 458 459 /* 460 * Increment a disk's busy counter. If the counter is going from 461 * 0 to 1, set the timestamp. 462 */ 463 void 464 disk_busy(struct disk *diskp) 465 { 466 int s; 467 468 /* 469 * XXX We'd like to use something as accurate as microtime(), 470 * but that doesn't depend on the system TOD clock. 471 */ 472 if (diskp->dk_busy++ == 0) { 473 s = splclock(); 474 diskp->dk_timestamp = mono_time; 475 splx(s); 476 } 477 } 478 479 /* 480 * Decrement a disk's busy counter, increment the byte count, total busy 481 * time, and reset the timestamp. 482 */ 483 void 484 disk_unbusy(struct disk *diskp, long bcount) 485 { 486 int s; 487 struct timeval dv_time, diff_time; 488 489 if (diskp->dk_busy-- == 0) { 490 printf("%s: dk_busy < 0\n", diskp->dk_name); 491 panic("disk_unbusy"); 492 } 493 494 s = splclock(); 495 dv_time = mono_time; 496 splx(s); 497 498 timersub(&dv_time, &diskp->dk_timestamp, &diff_time); 499 timeradd(&diskp->dk_time, &diff_time, &diskp->dk_time); 500 501 diskp->dk_timestamp = dv_time; 502 if (bcount > 0) { 503 diskp->dk_bytes += bcount; 504 diskp->dk_xfer++; 505 } 506 } 507 508 /* 509 * Reset the metrics counters on the given disk. Note that we cannot 510 * reset the busy counter, as it may case a panic in disk_unbusy(). 511 * We also must avoid playing with the timestamp information, as it 512 * may skew any pending transfer results. 513 */ 514 void 515 disk_resetstat(struct disk *diskp) 516 { 517 int s = splbio(), t; 518 519 diskp->dk_xfer = 0; 520 diskp->dk_bytes = 0; 521 522 t = splclock(); 523 diskp->dk_attachtime = mono_time; 524 splx(t); 525 526 timerclear(&diskp->dk_time); 527 528 splx(s); 529 } 530