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sys/dev/raid/vinum/vinumrequest.c
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1 /*- 2 * Copyright (c) 1997, 1998, 1999 3 * Nan Yang Computer Services Limited. All rights reserved. 4 * 5 * Parts copyright (c) 1997, 1998 Cybernet Corporation, NetMAX project. 6 * 7 * Written by Greg Lehey 8 * 9 * This software is distributed under the so-called ``Berkeley 10 * License'': 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 Nan Yang Computer 23 * Services Limited. 24 * 4. Neither the name of the Company 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 ``as is'', and any express or implied 29 * warranties, including, but not limited to, the implied warranties of 30 * merchantability and fitness for a particular purpose are disclaimed. 31 * In no event shall the company or contributors be liable for any 32 * direct, indirect, incidental, special, exemplary, or consequential 33 * damages (including, but not limited to, procurement of substitute 34 * goods or services; loss of use, data, or profits; or business 35 * interruption) however caused and on any theory of liability, whether 36 * in contract, strict liability, or tort (including negligence or 37 * otherwise) arising in any way out of the use of this software, even if 38 * advised of the possibility of such damage. 39 * 40 * $Id: vinumrequest.c,v 1.30 2001/01/09 04:20:55 grog Exp grog $ 41 * $FreeBSD: src/sys/dev/vinum/vinumrequest.c,v 1.44.2.5 2002/08/28 04:30:56 grog Exp $ 42 */ 43 44 #include "vinumhdr.h" 45 #include "request.h" 46 #include <sys/resourcevar.h> 47 48 enum requeststatus bre(struct request *rq, 49 int plexno, 50 vinum_off_t * diskstart, 51 vinum_off_t diskend); 52 enum requeststatus bre5(struct request *rq, 53 int plexno, 54 vinum_off_t * diskstart, 55 vinum_off_t diskend); 56 enum requeststatus build_read_request(struct request *rq, int volplexno); 57 enum requeststatus build_write_request(struct request *rq); 58 enum requeststatus build_rq_buffer(struct rqelement *rqe, struct plex *plex); 59 int find_alternate_sd(struct request *rq); 60 int check_range_covered(struct request *); 61 void complete_rqe(struct bio *bio); 62 void complete_raid5_write(struct rqelement *); 63 int abortrequest(struct request *rq, int error); 64 void sdio_done(struct bio *bio); 65 struct bio *vinum_bounds_check(struct bio *bio, struct volume *vol); 66 caddr_t allocdatabuf(struct rqelement *rqe); 67 void freedatabuf(struct rqelement *rqe); 68 69 #ifdef VINUMDEBUG 70 struct rqinfo rqinfo[RQINFO_SIZE]; 71 struct rqinfo *rqip = rqinfo; 72 73 void 74 logrq(enum rqinfo_type type, union rqinfou info, struct bio *ubio) 75 { 76 cdev_t dev; 77 78 crit_enter(); 79 80 microtime(&rqip->timestamp); /* when did this happen? */ 81 rqip->type = type; 82 rqip->bio = ubio; /* user buffer */ 83 84 switch (type) { 85 case loginfo_user_bp: 86 case loginfo_user_bpl: 87 case loginfo_sdio: /* subdisk I/O */ 88 case loginfo_sdiol: /* subdisk I/O launch */ 89 case loginfo_sdiodone: /* subdisk I/O complete */ 90 bcopy(info.bio, &rqip->info.bio, sizeof(struct bio)); 91 dev = info.bio->bio_driver_info; 92 rqip->devmajor = major(dev); 93 rqip->devminor = minor(dev); 94 break; 95 96 case loginfo_iodone: 97 case loginfo_rqe: 98 case loginfo_raid5_data: 99 case loginfo_raid5_parity: 100 bcopy(info.rqe, &rqip->info.rqe, sizeof(struct rqelement)); 101 dev = info.rqe->b.b_bio1.bio_driver_info; 102 rqip->devmajor = major(dev); 103 rqip->devminor = minor(dev); 104 break; 105 106 case loginfo_lockwait: 107 case loginfo_lock: 108 case loginfo_unlock: 109 bcopy(info.lockinfo, &rqip->info.lockinfo, sizeof(struct rangelock)); 110 111 break; 112 113 case loginfo_unused: 114 break; 115 } 116 rqip++; 117 if (rqip >= &rqinfo[RQINFO_SIZE]) /* wrap around */ 118 rqip = rqinfo; 119 crit_exit(); 120 } 121 122 #endif 123 124 int 125 vinumstrategy(struct dev_strategy_args *ap) 126 { 127 cdev_t dev = ap->a_head.a_dev; 128 struct bio *bio = ap->a_bio; 129 struct buf *bp = bio->bio_buf; 130 struct bio *nbio = bio; 131 struct volume *vol = NULL; 132 int volno; 133 134 switch (DEVTYPE(dev)) { 135 case VINUM_SD_TYPE: 136 case VINUM_RAWSD_TYPE: 137 bio->bio_driver_info = dev; 138 sdio(bio); 139 break; 140 case VINUM_DRIVE_TYPE: 141 default: 142 /* 143 * In fact, vinum doesn't handle drives: they're 144 * handled directly by the disk drivers 145 */ 146 bp->b_error = EIO; /* I/O error */ 147 bp->b_flags |= B_ERROR; 148 biodone(bio); 149 break; 150 151 case VINUM_VOLUME_TYPE: /* volume I/O */ 152 volno = Volno(dev); 153 vol = &VOL[volno]; 154 if (vol->state != volume_up) { /* can't access this volume */ 155 bp->b_error = EIO; /* I/O error */ 156 bp->b_flags |= B_ERROR; 157 biodone(bio); 158 break; 159 } 160 nbio = vinum_bounds_check(bio, vol); 161 if (nbio == NULL) { 162 biodone(bio); 163 break; 164 } 165 /* FALLTHROUGH */ 166 case VINUM_PLEX_TYPE: 167 case VINUM_RAWPLEX_TYPE: 168 /* 169 * Plex I/O is pretty much the same as volume I/O 170 * for a single plex. Indicate this by passing a NULL 171 * pointer (set above) for the volume 172 */ 173 bp->b_resid = bp->b_bcount; /* transfer everything */ 174 vinumstart(dev, nbio, 0); 175 break; 176 } 177 return(0); 178 } 179 180 /* 181 * Start a transfer. Return -1 on error, 182 * 0 if OK, 1 if we need to retry. 183 * Parameter reviveok is set when doing 184 * transfers for revives: it allows transfers to 185 * be started immediately when a revive is in 186 * progress. During revive, normal transfers 187 * are queued if they share address space with 188 * a currently active revive operation. 189 */ 190 int 191 vinumstart(cdev_t dev, struct bio *bio, int reviveok) 192 { 193 struct buf *bp = bio->bio_buf; 194 int plexno; 195 struct volume *vol; 196 struct request *rq; /* build up our request here */ 197 enum requeststatus status; 198 199 bio->bio_driver_info = dev; 200 201 #if VINUMDEBUG 202 if (debug & DEBUG_LASTREQS) 203 logrq(loginfo_user_bp, (union rqinfou) bio, bio); 204 #endif 205 206 if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */ 207 bp->b_error = EINVAL; /* invalid size */ 208 bp->b_flags |= B_ERROR; 209 biodone(bio); 210 return -1; 211 } 212 rq = (struct request *) Malloc(sizeof(struct request)); /* allocate a request struct */ 213 if (rq == NULL) { /* can't do it */ 214 bp->b_error = ENOMEM; /* can't get memory */ 215 bp->b_flags |= B_ERROR; 216 biodone(bio); 217 return -1; 218 } 219 bzero(rq, sizeof(struct request)); 220 221 /* 222 * Note the volume ID. This can be NULL, which 223 * the request building functions use as an 224 * indication for single plex I/O 225 */ 226 rq->bio = bio; /* and the user buffer struct */ 227 228 if (DEVTYPE(dev) == VINUM_VOLUME_TYPE) { /* it's a volume, */ 229 rq->volplex.volno = Volno(dev); /* get the volume number */ 230 vol = &VOL[rq->volplex.volno]; /* and point to it */ 231 vol->active++; /* one more active request */ 232 } else { 233 vol = NULL; /* no volume */ 234 rq->volplex.plexno = Plexno(dev); /* point to the plex */ 235 rq->isplex = 1; /* note that it's a plex */ 236 } 237 238 if (bp->b_cmd == BUF_CMD_READ) { 239 /* 240 * This is a read request. Decide 241 * which plex to read from. 242 * 243 * There's a potential race condition here, 244 * since we're not locked, and we could end 245 * up multiply incrementing the round-robin 246 * counter. This doesn't have any serious 247 * effects, however. 248 */ 249 if (vol != NULL) { 250 plexno = vol->preferred_plex; /* get the plex to use */ 251 if (plexno < 0) { /* round robin */ 252 plexno = vol->last_plex_read; 253 vol->last_plex_read++; 254 if (vol->last_plex_read >= vol->plexes) /* got the the end? */ 255 vol->last_plex_read = 0; /* wrap around */ 256 } 257 status = build_read_request(rq, plexno); /* build a request */ 258 } else { 259 vinum_off_t diskaddr = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT); 260 /* start offset of transfer */ 261 status = bre(rq, /* build a request list */ 262 rq->volplex.plexno, 263 &diskaddr, 264 diskaddr + (bp->b_bcount / DEV_BSIZE)); 265 } 266 267 if (status > REQUEST_RECOVERED) { /* can't satisfy it */ 268 if (status == REQUEST_DOWN) { /* not enough subdisks */ 269 bp->b_error = EIO; /* I/O error */ 270 bp->b_flags |= B_ERROR; 271 } 272 biodone(bio); 273 freerq(rq); 274 return -1; 275 } 276 return launch_requests(rq, reviveok); /* now start the requests if we can */ 277 } else 278 /* 279 * This is a write operation. We write to all plexes. If this is 280 * a RAID-4 or RAID-5 plex, we must also update the parity stripe. 281 */ 282 { 283 if (vol != NULL) 284 status = build_write_request(rq); /* Not all the subdisks are up */ 285 else { /* plex I/O */ 286 vinum_off_t diskstart; 287 vinum_off_t diskend; 288 289 diskstart = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */ 290 diskend = diskstart + bp->b_bcount / DEV_BSIZE; 291 status = bre(rq, Plexno(dev), 292 &diskstart, diskend); /* build requests for the plex */ 293 } 294 if (status > REQUEST_RECOVERED) { /* can't satisfy it */ 295 if (status == REQUEST_DOWN) { /* not enough subdisks */ 296 bp->b_error = EIO; /* I/O error */ 297 bp->b_flags |= B_ERROR; 298 } 299 biodone(bio); 300 freerq(rq); 301 return -1; 302 } 303 return launch_requests(rq, reviveok); /* now start the requests if we can */ 304 } 305 } 306 307 /* 308 * Call the low-level strategy routines to 309 * perform the requests in a struct request 310 */ 311 int 312 launch_requests(struct request *rq, int reviveok) 313 { 314 struct rqgroup *rqg; 315 int rqno; /* loop index */ 316 struct rqelement *rqe; /* current element */ 317 struct drive *drive; 318 int rcount; /* request count */ 319 320 /* 321 * First find out whether we're reviving, and the 322 * request contains a conflict. If so, we hang 323 * the request off plex->waitlist of the first 324 * plex we find which is reviving 325 */ 326 327 if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */ 328 &&(!reviveok)) { /* and we don't want to do it now, */ 329 struct sd *sd; 330 struct request *waitlist; /* point to the waitlist */ 331 332 sd = &SD[rq->sdno]; 333 if (sd->waitlist != NULL) { /* something there already, */ 334 waitlist = sd->waitlist; 335 while (waitlist->next != NULL) /* find the end */ 336 waitlist = waitlist->next; 337 waitlist->next = rq; /* hook our request there */ 338 } else 339 sd->waitlist = rq; /* hook our request at the front */ 340 341 #if VINUMDEBUG 342 if (debug & DEBUG_REVIVECONFLICT) { 343 log(LOG_DEBUG, 344 "Revive conflict sd %d: %p\n%s dev %d.%d, offset 0x%llx, length %d\n", 345 rq->sdno, 346 rq, 347 (rq->bio->bio_buf->b_cmd & BUF_CMD_READ) ? "Read" : "Write", 348 major(((cdev_t)rq->bio->bio_driver_info)), 349 minor(((cdev_t)rq->bio->bio_driver_info)), 350 rq->bio->bio_offset, 351 rq->bio->bio_buf->b_bcount); 352 } 353 #endif 354 return 0; /* and get out of here */ 355 } 356 rq->active = 0; /* nothing yet */ 357 #if VINUMDEBUG 358 if (debug & DEBUG_ADDRESSES) 359 log(LOG_DEBUG, 360 "Request: %p\n%s dev %d.%d, offset 0x%llx, length %d\n", 361 rq, 362 (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) ? "Read" : "Write", 363 major(((cdev_t)rq->bio->bio_driver_info)), 364 minor(((cdev_t)rq->bio->bio_driver_info)), 365 rq->bio->bio_offset, 366 rq->bio->bio_buf->b_bcount); 367 vinum_conf.lastrq = rq; 368 vinum_conf.lastbio = rq->bio; 369 if (debug & DEBUG_LASTREQS) 370 logrq(loginfo_user_bpl, (union rqinfou) rq->bio, rq->bio); 371 #endif 372 373 /* 374 * This loop happens without any participation 375 * of the bottom half, so it requires no 376 * protection. 377 */ 378 for (rqg = rq->rqg; rqg != NULL; rqg = rqg->next) { /* through the whole request chain */ 379 rqg->active = rqg->count; /* they're all active */ 380 for (rqno = 0; rqno < rqg->count; rqno++) { 381 rqe = &rqg->rqe[rqno]; 382 if (rqe->flags & XFR_BAD_SUBDISK) /* this subdisk is bad, */ 383 rqg->active--; /* one less active request */ 384 } 385 if (rqg->active) /* we have at least one active request, */ 386 rq->active++; /* one more active request group */ 387 } 388 389 /* 390 * Now fire off the requests. In this loop the 391 * bottom half could be completing requests 392 * before we finish, so we need critical section protection. 393 */ 394 crit_enter(); 395 for (rqg = rq->rqg; rqg != NULL;) { /* through the whole request chain */ 396 if (rqg->lockbase >= 0) /* this rqg needs a lock first */ 397 rqg->lock = lockrange(rqg->lockbase, rqg->rq->bio->bio_buf, &PLEX[rqg->plexno]); 398 rcount = rqg->count; 399 for (rqno = 0; rqno < rcount;) { 400 cdev_t dev; 401 402 rqe = &rqg->rqe[rqno]; 403 404 /* 405 * Point to next rqg before the bottom end 406 * changes the structures. 407 */ 408 if (++rqno >= rcount) 409 rqg = rqg->next; 410 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) { /* this subdisk is good, */ 411 drive = &DRIVE[rqe->driveno]; /* look at drive */ 412 drive->active++; 413 if (drive->active >= drive->maxactive) 414 drive->maxactive = drive->active; 415 vinum_conf.active++; 416 if (vinum_conf.active >= vinum_conf.maxactive) 417 vinum_conf.maxactive = vinum_conf.active; 418 419 dev = rqe->b.b_bio1.bio_driver_info; 420 #ifdef VINUMDEBUG 421 if (debug & DEBUG_ADDRESSES) 422 log(LOG_DEBUG, 423 " %s dev %d.%d, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n", 424 (rqe->b.b_cmd == BUF_CMD_READ) ? "Read" : "Write", 425 major(dev), 426 minor(dev), 427 rqe->sdno, 428 rqe->b.b_bio1.bio_offset - ((off_t)SD[rqe->sdno].driveoffset << DEV_BSHIFT), 429 rqe->b.b_bio1.bio_offset, 430 rqe->b.b_bcount); 431 if (debug & DEBUG_LASTREQS) 432 logrq(loginfo_rqe, (union rqinfou) rqe, rq->bio); 433 #endif 434 /* fire off the request */ 435 /* XXX this had better not be a low level drive */ 436 dev_dstrategy(dev, &rqe->b.b_bio1); 437 } 438 } 439 } 440 crit_exit(); 441 return 0; 442 } 443 444 /* 445 * define the low-level requests needed to perform a 446 * high-level I/O operation for a specific plex 'plexno'. 447 * 448 * Return REQUEST_OK if all subdisks involved in the request are up, 449 * REQUEST_DOWN if some subdisks are not up, and REQUEST_EOF if the 450 * request is at least partially outside the bounds of the subdisks. 451 * 452 * Modify the pointer *diskstart to point to the end address. On 453 * read, return on the first bad subdisk, so that the caller 454 * (build_read_request) can try alternatives. 455 * 456 * On entry to this routine, the rqg structures are not assigned. The 457 * assignment is performed by expandrq(). Strictly speaking, the 458 * elements rqe->sdno of all entries should be set to -1, since 0 459 * (from bzero) is a valid subdisk number. We avoid this problem by 460 * initializing the ones we use, and not looking at the others (index 461 * >= rqg->requests). 462 */ 463 enum requeststatus 464 bre(struct request *rq, 465 int plexno, 466 vinum_off_t * diskaddr, 467 vinum_off_t diskend) 468 { 469 int sdno; 470 struct sd *sd; 471 struct rqgroup *rqg; 472 struct bio *bio; 473 struct buf *bp; /* user's bp */ 474 struct plex *plex; 475 enum requeststatus status; /* return value */ 476 vinum_off_t plexoffset; /* offset of transfer in plex */ 477 vinum_off_t stripebase; /* base address of stripe (1st subdisk) */ 478 vinum_off_t stripeoffset; /* offset in stripe */ 479 vinum_off_t blockoffset; /* offset in stripe on subdisk */ 480 struct rqelement *rqe; /* point to this request information */ 481 vinum_off_t diskstart = *diskaddr; /* remember where this transfer starts */ 482 enum requeststatus s; /* temp return value */ 483 484 bio = rq->bio; /* buffer pointer */ 485 bp = bio->bio_buf; 486 status = REQUEST_OK; /* return value: OK until proven otherwise */ 487 plex = &PLEX[plexno]; /* point to the plex */ 488 489 switch (plex->organization) { 490 case plex_concat: 491 sd = NULL; /* (keep compiler quiet) */ 492 for (sdno = 0; sdno < plex->subdisks; sdno++) { 493 sd = &SD[plex->sdnos[sdno]]; 494 if (*diskaddr < sd->plexoffset) /* we must have a hole, */ 495 status = REQUEST_DEGRADED; /* note the fact */ 496 if (*diskaddr < (sd->plexoffset + sd->sectors)) { /* the request starts in this subdisk */ 497 rqg = allocrqg(rq, 1); /* space for the request */ 498 if (rqg == NULL) { /* malloc failed */ 499 bp->b_error = ENOMEM; 500 bp->b_flags |= B_ERROR; 501 return REQUEST_ENOMEM; 502 } 503 rqg->plexno = plexno; 504 505 rqe = &rqg->rqe[0]; /* point to the element */ 506 rqe->rqg = rqg; /* group */ 507 rqe->sdno = sd->sdno; /* put in the subdisk number */ 508 plexoffset = *diskaddr; /* start offset in plex */ 509 rqe->sdoffset = plexoffset - sd->plexoffset; /* start offset in subdisk */ 510 rqe->useroffset = plexoffset - diskstart; /* start offset in user buffer */ 511 rqe->dataoffset = 0; 512 rqe->datalen = u64min(diskend - *diskaddr, 513 sd->sectors - rqe->sdoffset); 514 rqe->groupoffset = 0; /* no groups for concatenated plexes */ 515 rqe->grouplen = 0; 516 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ 517 rqe->flags = 0; 518 rqe->driveno = sd->driveno; 519 if (sd->state != sd_up) { /* *now* we find the sd is down */ 520 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ 521 if (s == REQUEST_DOWN) { /* down? */ 522 rqe->flags = XFR_BAD_SUBDISK; /* yup */ 523 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */ 524 return REQUEST_DEGRADED; /* give up here */ 525 /* 526 * If we're writing, don't give up 527 * because of a bad subdisk. Go 528 * through to the bitter end, but note 529 * which ones we can't access. 530 */ 531 status = REQUEST_DEGRADED; /* can't do it all */ 532 } 533 } 534 *diskaddr += rqe->datalen; /* bump the address */ 535 if (build_rq_buffer(rqe, plex)) { /* build the buffer */ 536 deallocrqg(rqg); 537 bp->b_error = ENOMEM; 538 bp->b_flags |= B_ERROR; 539 return REQUEST_ENOMEM; /* can't do it */ 540 } 541 } 542 if (*diskaddr == diskend) /* we're finished, */ 543 break; /* get out of here */ 544 } 545 /* 546 * We've got to the end of the plex. Have we got to the end of 547 * the transfer? It would seem that having an offset beyond the 548 * end of the subdisk is an error, but in fact it can happen if 549 * the volume has another plex of different size. There's a valid 550 * question as to why you would want to do this, but currently 551 * it's allowed. 552 * 553 * In a previous version, I returned REQUEST_DOWN here. I think 554 * REQUEST_EOF is more appropriate now. 555 */ 556 if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */ 557 status = REQUEST_EOF; 558 break; 559 560 case plex_striped: 561 { 562 while (*diskaddr < diskend) { /* until we get it all sorted out */ 563 if (*diskaddr >= plex->length) /* beyond the end of the plex */ 564 return REQUEST_EOF; /* can't continue */ 565 566 /* The offset of the start address from the start of the stripe. */ 567 stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks); 568 569 /* The plex-relative address of the start of the stripe. */ 570 stripebase = *diskaddr - stripeoffset; 571 572 /* The number of the subdisk in which the start is located. */ 573 sdno = stripeoffset / plex->stripesize; 574 575 /* The offset from the beginning of the stripe on this subdisk. */ 576 blockoffset = stripeoffset % plex->stripesize; 577 578 sd = &SD[plex->sdnos[sdno]]; /* the subdisk in question */ 579 rqg = allocrqg(rq, 1); /* space for the request */ 580 if (rqg == NULL) { /* malloc failed */ 581 bp->b_error = ENOMEM; 582 bp->b_flags |= B_ERROR; 583 return REQUEST_ENOMEM; 584 } 585 rqg->plexno = plexno; 586 587 rqe = &rqg->rqe[0]; /* point to the element */ 588 rqe->rqg = rqg; 589 rqe->sdoffset = stripebase / plex->subdisks + blockoffset; /* start offset in this subdisk */ 590 rqe->useroffset = *diskaddr - diskstart; /* The offset of the start in the user buffer */ 591 rqe->dataoffset = 0; 592 rqe->datalen = u64min(diskend - *diskaddr, 593 plex->stripesize - blockoffset); 594 rqe->groupoffset = 0; /* no groups for striped plexes */ 595 rqe->grouplen = 0; 596 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ 597 rqe->flags = 0; 598 rqe->sdno = sd->sdno; /* put in the subdisk number */ 599 rqe->driveno = sd->driveno; 600 601 if (sd->state != sd_up) { /* *now* we find the sd is down */ 602 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ 603 if (s == REQUEST_DOWN) { /* down? */ 604 rqe->flags = XFR_BAD_SUBDISK; /* yup */ 605 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */ 606 return REQUEST_DEGRADED; /* give up here */ 607 /* 608 * If we're writing, don't give up 609 * because of a bad subdisk. Go through 610 * to the bitter end, but note which 611 * ones we can't access. 612 */ 613 status = REQUEST_DEGRADED; /* can't do it all */ 614 } 615 } 616 /* 617 * It would seem that having an offset 618 * beyond the end of the subdisk is an 619 * error, but in fact it can happen if the 620 * volume has another plex of different 621 * size. There's a valid question as to why 622 * you would want to do this, but currently 623 * it's allowed. 624 */ 625 if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */ 626 rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */ 627 #if VINUMDEBUG 628 if (debug & DEBUG_EOFINFO) { /* tell on the request */ 629 log(LOG_DEBUG, 630 "vinum: EOF on plex %s, sd %s offset %jx (user offset %jx)\n", 631 plex->name, 632 sd->name, 633 (uintmax_t)sd->sectors, 634 (uintmax_t)bp->b_bio1.bio_offset); 635 log(LOG_DEBUG, 636 "vinum: stripebase 0x%llx, stripeoffset 0x%llx, " 637 "blockoffset 0x%llx\n", 638 (long long)stripebase, 639 (long long)stripeoffset, 640 (long long)blockoffset); 641 } 642 #endif 643 } 644 if (build_rq_buffer(rqe, plex)) { /* build the buffer */ 645 deallocrqg(rqg); 646 bp->b_error = ENOMEM; 647 bp->b_flags |= B_ERROR; 648 return REQUEST_ENOMEM; /* can't do it */ 649 } 650 *diskaddr += rqe->datalen; /* look at the remainder */ 651 if ((*diskaddr < diskend) /* didn't finish the request on this stripe */ 652 &&(*diskaddr < plex->length)) { /* and there's more to come */ 653 plex->multiblock++; /* count another one */ 654 if (sdno == plex->subdisks - 1) /* last subdisk, */ 655 plex->multistripe++; /* another stripe as well */ 656 } 657 } 658 } 659 break; 660 661 /* 662 * RAID-4 and RAID-5 are complicated enough to have their own 663 * function. 664 */ 665 case plex_raid4: 666 case plex_raid5: 667 status = bre5(rq, plexno, diskaddr, diskend); 668 break; 669 670 default: 671 log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization); 672 status = REQUEST_DOWN; /* can't access it */ 673 } 674 675 return status; 676 } 677 678 /* 679 * Build up a request structure for reading volumes. 680 * This function is not needed for plex reads, since there's 681 * no recovery if a plex read can't be satisified. 682 */ 683 enum requeststatus 684 build_read_request(struct request *rq, /* request */ 685 int plexindex) 686 { /* index in the volume's plex table */ 687 struct bio *bio; 688 struct buf *bp; 689 vinum_off_t startaddr; /* offset of previous part of transfer */ 690 vinum_off_t diskaddr; /* offset of current part of transfer */ 691 vinum_off_t diskend; /* and end offset of transfer */ 692 int plexno; /* plex index in vinum_conf */ 693 struct volume *vol; /* volume in question */ 694 int recovered = 0; /* set if we recover a read */ 695 enum requeststatus status = REQUEST_OK; 696 int plexmask; /* bit mask of plexes, for recovery */ 697 698 bio = rq->bio; /* buffer pointer */ 699 bp = bio->bio_buf; 700 diskaddr = bio->bio_offset >> DEV_BSHIFT; /* start offset of transfer */ 701 diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */ 702 vol = &VOL[rq->volplex.volno]; /* point to volume */ 703 704 while (diskaddr < diskend) { /* build up request components */ 705 startaddr = diskaddr; 706 status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */ 707 switch (status) { 708 case REQUEST_OK: 709 continue; 710 711 case REQUEST_RECOVERED: 712 /* 713 * XXX FIXME if we have more than one plex, and we can 714 * satisfy the request from another, don't use the 715 * recovered request, since it's more expensive. 716 */ 717 recovered = 1; 718 break; 719 720 case REQUEST_ENOMEM: 721 return status; 722 /* 723 * If we get here, our request is not complete. Try 724 * to fill in the missing parts from another plex. 725 * This can happen multiple times in this function, 726 * and we reinitialize the plex mask each time, since 727 * we could have a hole in our plexes. 728 */ 729 case REQUEST_EOF: 730 case REQUEST_DOWN: /* can't access the plex */ 731 case REQUEST_DEGRADED: /* can't access the plex */ 732 plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */ 733 &~(1 << plexindex); /* except for the one we were looking at */ 734 for (plexno = 0; plexno < vol->plexes; plexno++) { 735 if (plexmask == 0) /* no plexes left to try */ 736 return REQUEST_DOWN; /* failed */ 737 diskaddr = startaddr; /* start at the beginning again */ 738 if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */ 739 bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */ 740 if (diskaddr > startaddr) { /* we satisfied another part */ 741 recovered = 1; /* we recovered from the problem */ 742 status = REQUEST_OK; /* don't complain about it */ 743 break; 744 } 745 } 746 } 747 if (diskaddr == startaddr) /* didn't get any further, */ 748 return status; 749 } 750 if (recovered) 751 vol->recovered_reads += recovered; /* adjust our recovery count */ 752 } 753 return status; 754 } 755 756 /* 757 * Build up a request structure for writes. 758 * Return 0 if all subdisks involved in the request are up, 1 if some 759 * subdisks are not up, and -1 if the request is at least partially 760 * outside the bounds of the subdisks. 761 */ 762 enum requeststatus 763 build_write_request(struct request *rq) 764 { /* request */ 765 struct bio *bio; 766 struct buf *bp; 767 vinum_off_t diskstart; /* offset of current part of transfer */ 768 vinum_off_t diskend; /* and end offset of transfer */ 769 int plexno; /* plex index in vinum_conf */ 770 struct volume *vol; /* volume in question */ 771 enum requeststatus status; 772 773 bio = rq->bio; /* buffer pointer */ 774 bp = bio->bio_buf; 775 vol = &VOL[rq->volplex.volno]; /* point to volume */ 776 diskend = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT) + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */ 777 status = REQUEST_DOWN; /* assume the worst */ 778 for (plexno = 0; plexno < vol->plexes; plexno++) { 779 diskstart = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */ 780 /* 781 * Build requests for the plex. 782 * We take the best possible result here (min, 783 * not max): we're happy if we can write at all 784 */ 785 status = u64min(status, 786 bre(rq, vol->plex[plexno], &diskstart, diskend)); 787 } 788 return status; 789 } 790 791 /* Fill in the struct buf part of a request element. */ 792 enum requeststatus 793 build_rq_buffer(struct rqelement *rqe, struct plex *plex) 794 { 795 struct sd *sd; /* point to subdisk */ 796 struct buf *bp; 797 struct buf *ubp; /* user (high level) buffer header */ 798 struct bio *ubio; 799 800 sd = &SD[rqe->sdno]; /* point to subdisk */ 801 bp = &rqe->b; 802 ubio = rqe->rqg->rq->bio; /* pointer to user buffer header */ 803 ubp = ubio->bio_buf; 804 805 /* Initialize the buf struct */ 806 /* copy these flags from user bp */ 807 bp->b_flags = ubp->b_flags & (B_ORDERED | B_NOCACHE); 808 bp->b_cmd = ubp->b_cmd; 809 #ifdef VINUMDEBUG 810 if (rqe->flags & XFR_BUFLOCKED) /* paranoia */ 811 panic("build_rq_buffer: rqe already locked"); /* XXX remove this when we're sure */ 812 #endif 813 initbufbio(bp); 814 BUF_LOCK(bp, LK_EXCLUSIVE); /* and lock it */ 815 BUF_KERNPROC(bp); 816 rqe->flags |= XFR_BUFLOCKED; 817 bp->b_bio1.bio_done = complete_rqe; 818 /* 819 * You'd think that we wouldn't need to even 820 * build the request buffer for a dead subdisk, 821 * but in some cases we need information like 822 * the user buffer address. Err on the side of 823 * generosity and supply what we can. That 824 * obviously doesn't include drive information 825 * when the drive is dead. 826 */ 827 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) /* subdisk is accessible, */ 828 bp->b_bio1.bio_driver_info = DRIVE[rqe->driveno].dev; /* drive device */ 829 bp->b_bio1.bio_offset = (off_t)(rqe->sdoffset + sd->driveoffset) << DEV_BSHIFT; /* start address */ 830 bp->b_bcount = rqe->buflen << DEV_BSHIFT; /* number of bytes to transfer */ 831 bp->b_resid = bp->b_bcount; /* and it's still all waiting */ 832 833 if (rqe->flags & XFR_MALLOCED) { /* this operation requires a malloced buffer */ 834 bp->b_data = Malloc(bp->b_bcount); /* get a buffer to put it in */ 835 if (bp->b_data == NULL) { /* failed */ 836 abortrequest(rqe->rqg->rq, ENOMEM); 837 return REQUEST_ENOMEM; /* no memory */ 838 } 839 } else 840 /* 841 * Point directly to user buffer data. This means 842 * that we don't need to do anything when we have 843 * finished the transfer 844 */ 845 bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE; 846 /* 847 * On a recovery read, we perform an XOR of 848 * all blocks to the user buffer. To make 849 * this work, we first clean out the buffer 850 */ 851 if ((rqe->flags & (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) 852 == (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) { /* bad subdisk of a recovery read */ 853 int length = rqe->grouplen << DEV_BSHIFT; /* and count involved */ 854 char *data = (char *) &rqe->b.b_data[rqe->groupoffset << DEV_BSHIFT]; /* destination */ 855 856 bzero(data, length); /* clean it out */ 857 } 858 return 0; 859 } 860 861 /* 862 * Abort a request: free resources and complete the 863 * user request with the specified error 864 */ 865 int 866 abortrequest(struct request *rq, int error) 867 { 868 struct buf *bp = rq->bio->bio_buf; /* user buffer */ 869 870 bp->b_error = error; 871 freerq(rq); /* free everything we're doing */ 872 bp->b_flags |= B_ERROR; 873 return error; /* and give up */ 874 } 875 876 /* 877 * Check that our transfer will cover the 878 * complete address space of the user request. 879 * 880 * Return 1 if it can, otherwise 0 881 */ 882 int 883 check_range_covered(struct request *rq) 884 { 885 return 1; 886 } 887 888 /* Perform I/O on a subdisk */ 889 void 890 sdio(struct bio *bio) 891 { 892 cdev_t dev; 893 struct sd *sd; 894 struct sdbuf *sbp; 895 vinum_off_t endoffset; 896 struct drive *drive; 897 struct buf *bp = bio->bio_buf; 898 899 dev = bio->bio_driver_info; 900 901 #if VINUMDEBUG 902 if (debug & DEBUG_LASTREQS) 903 logrq(loginfo_sdio, (union rqinfou) bio, bio); 904 #endif 905 sd = &SD[Sdno(dev)]; /* point to the subdisk */ 906 drive = &DRIVE[sd->driveno]; 907 908 if (drive->state != drive_up) { 909 if (sd->state >= sd_crashed) { 910 if (bp->b_cmd != BUF_CMD_READ) /* writing, */ 911 set_sd_state(sd->sdno, sd_stale, setstate_force); 912 else 913 set_sd_state(sd->sdno, sd_crashed, setstate_force); 914 } 915 bp->b_error = EIO; 916 bp->b_flags |= B_ERROR; 917 biodone(bio); 918 return; 919 } 920 /* 921 * We allow access to any kind of subdisk as long as we can expect 922 * to get the I/O performed. 923 */ 924 if (sd->state < sd_empty) { /* nothing to talk to, */ 925 bp->b_error = EIO; 926 bp->b_flags |= B_ERROR; 927 biodone(bio); 928 return; 929 } 930 /* Get a buffer */ 931 sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf)); 932 if (sbp == NULL) { 933 bp->b_error = ENOMEM; 934 bp->b_flags |= B_ERROR; 935 biodone(bio); 936 return; 937 } 938 bzero(sbp, sizeof(struct sdbuf)); /* start with nothing */ 939 sbp->b.b_cmd = bp->b_cmd; 940 sbp->b.b_bcount = bp->b_bcount; /* number of bytes to transfer */ 941 sbp->b.b_resid = bp->b_resid; /* and amount waiting */ 942 sbp->b.b_data = bp->b_data; /* data buffer */ 943 initbufbio(&sbp->b); 944 BUF_LOCK(&sbp->b, LK_EXCLUSIVE); /* and lock it */ 945 BUF_KERNPROC(&sbp->b); 946 sbp->b.b_bio1.bio_offset = bio->bio_offset + ((off_t)sd->driveoffset << DEV_BSHIFT); 947 sbp->b.b_bio1.bio_done = sdio_done; /* come here on completion */ 948 sbp->b.b_bio1.bio_flags |= BIO_SYNC; 949 sbp->bio = bio; /* note the address of the original header */ 950 sbp->sdno = sd->sdno; /* note for statistics */ 951 sbp->driveno = sd->driveno; 952 endoffset = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT) + sbp->b.b_bcount / DEV_BSIZE; /* final sector offset */ 953 if (endoffset > sd->sectors) { /* beyond the end */ 954 sbp->b.b_bcount -= (endoffset - sd->sectors) * DEV_BSIZE; /* trim */ 955 if (sbp->b.b_bcount <= 0) { /* nothing to transfer */ 956 bp->b_resid = bp->b_bcount; /* nothing transferred */ 957 biodone(bio); 958 BUF_UNLOCK(&sbp->b); 959 uninitbufbio(&sbp->b); 960 Free(sbp); 961 return; 962 } 963 } 964 #if VINUMDEBUG 965 if (debug & DEBUG_ADDRESSES) 966 log(LOG_DEBUG, 967 " %s dev %s, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n", 968 (sbp->b.b_cmd == BUF_CMD_READ) ? "Read" : "Write", 969 drive->devicename, 970 sbp->sdno, 971 sbp->b.b_bio1.bio_offset - ((off_t)SD[sbp->sdno].driveoffset << DEV_BSHIFT), 972 sbp->b.b_bio1.bio_offset, 973 sbp->b.b_bcount); 974 #endif 975 crit_enter(); 976 #if VINUMDEBUG 977 if (debug & DEBUG_LASTREQS) 978 logrq(loginfo_sdiol, (union rqinfou) &sbp->b.b_bio1, &sbp->b.b_bio1); 979 #endif 980 vn_strategy(drive->vp, &sbp->b.b_bio1); 981 crit_exit(); 982 } 983 984 /* 985 * Determine the size of the transfer, and make sure it is 986 * within the boundaries of the partition. Adjust transfer 987 * if needed, and signal errors or early completion. 988 * 989 * Volumes are simpler than disk slices: they only contain 990 * one component (though we call them a, b and c to make 991 * system utilities happy), and they always take up the 992 * complete space of the "partition". 993 * 994 * I'm still not happy with this: why should the label be 995 * protected? If it weren't so damned difficult to write 996 * one in the first pleace (because it's protected), it wouldn't 997 * be a problem. 998 */ 999 struct bio * 1000 vinum_bounds_check(struct bio *bio, struct volume *vol) 1001 { 1002 struct buf *bp = bio->bio_buf; 1003 struct bio *nbio; 1004 vinum_off_t maxsize = vol->size; /* size of the partition (sectors) */ 1005 int size = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* size of this request (sectors) */ 1006 vinum_off_t blkno = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT); 1007 1008 if (size == 0) /* no transfer specified, */ 1009 return 0; /* treat as EOF */ 1010 /* beyond partition? */ 1011 if (bio->bio_offset < 0 /* negative start */ 1012 || blkno + size > maxsize) { /* or goes beyond the end of the partition */ 1013 /* if exactly at end of disk, return an EOF */ 1014 if (blkno == maxsize) { 1015 bp->b_resid = bp->b_bcount; 1016 return (NULL); 1017 } 1018 /* or truncate if part of it fits */ 1019 size = maxsize - blkno; 1020 if (size <= 0) { /* nothing to transfer */ 1021 bp->b_error = EINVAL; 1022 bp->b_flags |= B_ERROR; 1023 return (NULL); 1024 } 1025 bp->b_bcount = size << DEV_BSHIFT; 1026 } 1027 nbio = push_bio(bio); 1028 nbio->bio_offset = bio->bio_offset; 1029 return (nbio); 1030 } 1031 1032 /* 1033 * Allocate a request group and hook 1034 * it in in the list for rq 1035 */ 1036 struct rqgroup * 1037 allocrqg(struct request *rq, int elements) 1038 { 1039 struct rqgroup *rqg; /* the one we're going to allocate */ 1040 int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement); 1041 1042 rqg = (struct rqgroup *) Malloc(size); 1043 if (rqg != NULL) { /* malloc OK, */ 1044 if (rq->rqg) /* we already have requests */ 1045 rq->lrqg->next = rqg; /* hang it off the end */ 1046 else /* first request */ 1047 rq->rqg = rqg; /* at the start */ 1048 rq->lrqg = rqg; /* this one is the last in the list */ 1049 1050 bzero(rqg, size); /* no old junk */ 1051 rqg->rq = rq; /* point back to the parent request */ 1052 rqg->count = elements; /* number of requests in the group */ 1053 rqg->lockbase = -1; /* no lock required yet */ 1054 } 1055 return rqg; 1056 } 1057 1058 /* 1059 * Deallocate a request group out of a chain. We do 1060 * this by linear search: the chain is short, this 1061 * almost never happens, and currently it can only 1062 * happen to the first member of the chain. 1063 */ 1064 void 1065 deallocrqg(struct rqgroup *rqg) 1066 { 1067 struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */ 1068 1069 if (rqg->lock) /* got a lock? */ 1070 unlockrange(rqg->plexno, rqg->lock); /* yes, free it */ 1071 if (rqgc == rqg) /* we're first in line */ 1072 rqg->rq->rqg = rqg->next; /* unhook ourselves */ 1073 else { 1074 while ((rqgc->next != NULL) /* find the group */ 1075 &&(rqgc->next != rqg)) 1076 rqgc = rqgc->next; 1077 if (rqgc->next == NULL) 1078 log(LOG_ERR, 1079 "vinum deallocrqg: rqg %p not found in request %p\n", 1080 rqg->rq, 1081 rqg); 1082 else 1083 rqgc->next = rqg->next; /* make the chain jump over us */ 1084 } 1085 Free(rqg); 1086 }
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