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 * $DragonFly: src/sys/dev/raid/vinum/vinumrequest.c,v 1.21 2007/09/15 20:06:39 swildner Exp $ 43 */ 44 45 #include "vinumhdr.h" 46 #include "request.h" 47 #include <sys/resourcevar.h> 48 49 enum requeststatus bre(struct request *rq, 50 int plexno, 51 daddr_t * diskstart, 52 daddr_t diskend); 53 enum requeststatus bre5(struct request *rq, 54 int plexno, 55 daddr_t * diskstart, 56 daddr_t diskend); 57 enum requeststatus build_read_request(struct request *rq, int volplexno); 58 enum requeststatus build_write_request(struct request *rq); 59 enum requeststatus build_rq_buffer(struct rqelement *rqe, struct plex *plex); 60 int find_alternate_sd(struct request *rq); 61 int check_range_covered(struct request *); 62 void complete_rqe(struct bio *bio); 63 void complete_raid5_write(struct rqelement *); 64 int abortrequest(struct request *rq, int error); 65 void sdio_done(struct bio *bio); 66 struct bio *vinum_bounds_check(struct bio *bio, struct volume *vol); 67 caddr_t allocdatabuf(struct rqelement *rqe); 68 void freedatabuf(struct rqelement *rqe); 69 70 #ifdef VINUMDEBUG 71 struct rqinfo rqinfo[RQINFO_SIZE]; 72 struct rqinfo *rqip = rqinfo; 73 74 void 75 logrq(enum rqinfo_type type, union rqinfou info, struct bio *ubio) 76 { 77 cdev_t dev; 78 79 crit_enter(); 80 81 microtime(&rqip->timestamp); /* when did this happen? */ 82 rqip->type = type; 83 rqip->bio = ubio; /* user buffer */ 84 85 switch (type) { 86 case loginfo_user_bp: 87 case loginfo_user_bpl: 88 case loginfo_sdio: /* subdisk I/O */ 89 case loginfo_sdiol: /* subdisk I/O launch */ 90 case loginfo_sdiodone: /* subdisk I/O complete */ 91 bcopy(info.bio, &rqip->info.bio, sizeof(struct bio)); 92 dev = info.bio->bio_driver_info; 93 rqip->devmajor = major(dev); 94 rqip->devminor = minor(dev); 95 break; 96 97 case loginfo_iodone: 98 case loginfo_rqe: 99 case loginfo_raid5_data: 100 case loginfo_raid5_parity: 101 bcopy(info.rqe, &rqip->info.rqe, sizeof(struct rqelement)); 102 dev = info.rqe->b.b_bio1.bio_driver_info; 103 rqip->devmajor = major(dev); 104 rqip->devminor = minor(dev); 105 break; 106 107 case loginfo_lockwait: 108 case loginfo_lock: 109 case loginfo_unlock: 110 bcopy(info.lockinfo, &rqip->info.lockinfo, sizeof(struct rangelock)); 111 112 break; 113 114 case loginfo_unused: 115 break; 116 } 117 rqip++; 118 if (rqip >= &rqinfo[RQINFO_SIZE]) /* wrap around */ 119 rqip = rqinfo; 120 crit_exit(); 121 } 122 123 #endif 124 125 int 126 vinumstrategy(struct dev_strategy_args *ap) 127 { 128 cdev_t dev = ap->a_head.a_dev; 129 struct bio *bio = ap->a_bio; 130 struct buf *bp = bio->bio_buf; 131 struct bio *nbio = bio; 132 struct volume *vol = NULL; 133 int volno; 134 135 switch (DEVTYPE(dev)) { 136 case VINUM_SD_TYPE: 137 case VINUM_RAWSD_TYPE: 138 bio->bio_driver_info = dev; 139 sdio(bio); 140 break; 141 case VINUM_DRIVE_TYPE: 142 default: 143 /* 144 * In fact, vinum doesn't handle drives: they're 145 * handled directly by the disk drivers 146 */ 147 bp->b_error = EIO; /* I/O error */ 148 bp->b_flags |= B_ERROR; 149 biodone(bio); 150 break; 151 152 case VINUM_VOLUME_TYPE: /* volume I/O */ 153 volno = Volno(dev); 154 vol = &VOL[volno]; 155 if (vol->state != volume_up) { /* can't access this volume */ 156 bp->b_error = EIO; /* I/O error */ 157 bp->b_flags |= B_ERROR; 158 biodone(bio); 159 break; 160 } 161 nbio = vinum_bounds_check(bio, vol); 162 if (nbio == NULL) { 163 biodone(bio); 164 break; 165 } 166 /* FALLTHROUGH */ 167 case VINUM_PLEX_TYPE: 168 case VINUM_RAWPLEX_TYPE: 169 /* 170 * Plex I/O is pretty much the same as volume I/O 171 * for a single plex. Indicate this by passing a NULL 172 * pointer (set above) for the volume 173 */ 174 bp->b_resid = bp->b_bcount; /* transfer everything */ 175 vinumstart(dev, nbio, 0); 176 break; 177 } 178 return(0); 179 } 180 181 /* 182 * Start a transfer. Return -1 on error, 183 * 0 if OK, 1 if we need to retry. 184 * Parameter reviveok is set when doing 185 * transfers for revives: it allows transfers to 186 * be started immediately when a revive is in 187 * progress. During revive, normal transfers 188 * are queued if they share address space with 189 * a currently active revive operation. 190 */ 191 int 192 vinumstart(cdev_t dev, struct bio *bio, int reviveok) 193 { 194 struct buf *bp = bio->bio_buf; 195 int plexno; 196 int maxplex; /* maximum number of plexes to handle */ 197 struct volume *vol; 198 struct request *rq; /* build up our request here */ 199 enum requeststatus status; 200 201 bio->bio_driver_info = dev; 202 203 #if VINUMDEBUG 204 if (debug & DEBUG_LASTREQS) 205 logrq(loginfo_user_bp, (union rqinfou) bio, bio); 206 #endif 207 208 if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */ 209 bp->b_error = EINVAL; /* invalid size */ 210 bp->b_flags |= B_ERROR; 211 biodone(bio); 212 return -1; 213 } 214 rq = (struct request *) Malloc(sizeof(struct request)); /* allocate a request struct */ 215 if (rq == NULL) { /* can't do it */ 216 bp->b_error = ENOMEM; /* can't get memory */ 217 bp->b_flags |= B_ERROR; 218 biodone(bio); 219 return -1; 220 } 221 bzero(rq, sizeof(struct request)); 222 223 /* 224 * Note the volume ID. This can be NULL, which 225 * the request building functions use as an 226 * indication for single plex I/O 227 */ 228 rq->bio = bio; /* and the user buffer struct */ 229 230 if (DEVTYPE(dev) == VINUM_VOLUME_TYPE) { /* it's a volume, */ 231 rq->volplex.volno = Volno(dev); /* get the volume number */ 232 vol = &VOL[rq->volplex.volno]; /* and point to it */ 233 vol->active++; /* one more active request */ 234 maxplex = vol->plexes; /* consider all its plexes */ 235 } else { 236 vol = NULL; /* no volume */ 237 rq->volplex.plexno = Plexno(dev); /* point to the plex */ 238 rq->isplex = 1; /* note that it's a plex */ 239 maxplex = 1; /* just the one plex */ 240 } 241 242 if (bp->b_cmd == BUF_CMD_READ) { 243 /* 244 * This is a read request. Decide 245 * which plex to read from. 246 * 247 * There's a potential race condition here, 248 * since we're not locked, and we could end 249 * up multiply incrementing the round-robin 250 * counter. This doesn't have any serious 251 * effects, however. 252 */ 253 if (vol != NULL) { 254 plexno = vol->preferred_plex; /* get the plex to use */ 255 if (plexno < 0) { /* round robin */ 256 plexno = vol->last_plex_read; 257 vol->last_plex_read++; 258 if (vol->last_plex_read >= vol->plexes) /* got the the end? */ 259 vol->last_plex_read = 0; /* wrap around */ 260 } 261 status = build_read_request(rq, plexno); /* build a request */ 262 } else { 263 daddr_t diskaddr = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); 264 /* start offset of transfer */ 265 status = bre(rq, /* build a request list */ 266 rq->volplex.plexno, 267 &diskaddr, 268 diskaddr + (bp->b_bcount / DEV_BSIZE)); 269 } 270 271 if (status > REQUEST_RECOVERED) { /* can't satisfy it */ 272 if (status == REQUEST_DOWN) { /* not enough subdisks */ 273 bp->b_error = EIO; /* I/O error */ 274 bp->b_flags |= B_ERROR; 275 } 276 biodone(bio); 277 freerq(rq); 278 return -1; 279 } 280 return launch_requests(rq, reviveok); /* now start the requests if we can */ 281 } else 282 /* 283 * This is a write operation. We write to all plexes. If this is 284 * a RAID-4 or RAID-5 plex, we must also update the parity stripe. 285 */ 286 { 287 if (vol != NULL) 288 status = build_write_request(rq); /* Not all the subdisks are up */ 289 else { /* plex I/O */ 290 daddr_t diskstart; 291 daddr_t diskend; 292 293 diskstart = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */ 294 diskend = diskstart + bp->b_bcount / DEV_BSIZE; 295 status = bre(rq, Plexno(dev), 296 &diskstart, diskend); /* build requests for the plex */ 297 } 298 if (status > REQUEST_RECOVERED) { /* can't satisfy it */ 299 if (status == REQUEST_DOWN) { /* not enough subdisks */ 300 bp->b_error = EIO; /* I/O error */ 301 bp->b_flags |= B_ERROR; 302 } 303 biodone(bio); 304 freerq(rq); 305 return -1; 306 } 307 return launch_requests(rq, reviveok); /* now start the requests if we can */ 308 } 309 } 310 311 /* 312 * Call the low-level strategy routines to 313 * perform the requests in a struct request 314 */ 315 int 316 launch_requests(struct request *rq, int reviveok) 317 { 318 struct rqgroup *rqg; 319 int rqno; /* loop index */ 320 struct rqelement *rqe; /* current element */ 321 struct drive *drive; 322 int rcount; /* request count */ 323 324 /* 325 * First find out whether we're reviving, and the 326 * request contains a conflict. If so, we hang 327 * the request off plex->waitlist of the first 328 * plex we find which is reviving 329 */ 330 331 if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */ 332 &&(!reviveok)) { /* and we don't want to do it now, */ 333 struct sd *sd; 334 struct request *waitlist; /* point to the waitlist */ 335 336 sd = &SD[rq->sdno]; 337 if (sd->waitlist != NULL) { /* something there already, */ 338 waitlist = sd->waitlist; 339 while (waitlist->next != NULL) /* find the end */ 340 waitlist = waitlist->next; 341 waitlist->next = rq; /* hook our request there */ 342 } else 343 sd->waitlist = rq; /* hook our request at the front */ 344 345 #if VINUMDEBUG 346 if (debug & DEBUG_REVIVECONFLICT) { 347 log(LOG_DEBUG, 348 "Revive conflict sd %d: %p\n%s dev %d.%d, offset 0x%llx, length %d\n", 349 rq->sdno, 350 rq, 351 (rq->bio->bio_buf->b_cmd & BUF_CMD_READ) ? "Read" : "Write", 352 major(((cdev_t)rq->bio->bio_driver_info)), 353 minor(((cdev_t)rq->bio->bio_driver_info)), 354 rq->bio->bio_offset, 355 rq->bio->bio_buf->b_bcount); 356 } 357 #endif 358 return 0; /* and get out of here */ 359 } 360 rq->active = 0; /* nothing yet */ 361 #if VINUMDEBUG 362 if (debug & DEBUG_ADDRESSES) 363 log(LOG_DEBUG, 364 "Request: %p\n%s dev %d.%d, offset 0x%llx, length %d\n", 365 rq, 366 (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) ? "Read" : "Write", 367 major(((cdev_t)rq->bio->bio_driver_info)), 368 minor(((cdev_t)rq->bio->bio_driver_info)), 369 rq->bio->bio_offset, 370 rq->bio->bio_buf->b_bcount); 371 vinum_conf.lastrq = rq; 372 vinum_conf.lastbio = rq->bio; 373 if (debug & DEBUG_LASTREQS) 374 logrq(loginfo_user_bpl, (union rqinfou) rq->bio, rq->bio); 375 #endif 376 377 /* 378 * This loop happens without any participation 379 * of the bottom half, so it requires no 380 * protection. 381 */ 382 for (rqg = rq->rqg; rqg != NULL; rqg = rqg->next) { /* through the whole request chain */ 383 rqg->active = rqg->count; /* they're all active */ 384 for (rqno = 0; rqno < rqg->count; rqno++) { 385 rqe = &rqg->rqe[rqno]; 386 if (rqe->flags & XFR_BAD_SUBDISK) /* this subdisk is bad, */ 387 rqg->active--; /* one less active request */ 388 } 389 if (rqg->active) /* we have at least one active request, */ 390 rq->active++; /* one more active request group */ 391 } 392 393 /* 394 * Now fire off the requests. In this loop the 395 * bottom half could be completing requests 396 * before we finish, so we need critical section protection. 397 */ 398 crit_enter(); 399 for (rqg = rq->rqg; rqg != NULL;) { /* through the whole request chain */ 400 if (rqg->lockbase >= 0) /* this rqg needs a lock first */ 401 rqg->lock = lockrange(rqg->lockbase, rqg->rq->bio->bio_buf, &PLEX[rqg->plexno]); 402 rcount = rqg->count; 403 for (rqno = 0; rqno < rcount;) { 404 cdev_t dev; 405 406 rqe = &rqg->rqe[rqno]; 407 408 /* 409 * Point to next rqg before the bottom end 410 * changes the structures. 411 */ 412 if (++rqno >= rcount) 413 rqg = rqg->next; 414 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) { /* this subdisk is good, */ 415 drive = &DRIVE[rqe->driveno]; /* look at drive */ 416 drive->active++; 417 if (drive->active >= drive->maxactive) 418 drive->maxactive = drive->active; 419 vinum_conf.active++; 420 if (vinum_conf.active >= vinum_conf.maxactive) 421 vinum_conf.maxactive = vinum_conf.active; 422 423 dev = rqe->b.b_bio1.bio_driver_info; 424 #ifdef VINUMDEBUG 425 if (debug & DEBUG_ADDRESSES) 426 log(LOG_DEBUG, 427 " %s dev %d.%d, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n", 428 (rqe->b.b_cmd == BUF_CMD_READ) ? "Read" : "Write", 429 major(dev), 430 minor(dev), 431 rqe->sdno, 432 rqe->b.b_bio1.bio_offset - ((off_t)SD[rqe->sdno].driveoffset << DEV_BSHIFT), 433 rqe->b.b_bio1.bio_offset, 434 rqe->b.b_bcount); 435 if (debug & DEBUG_LASTREQS) 436 logrq(loginfo_rqe, (union rqinfou) rqe, rq->bio); 437 #endif 438 /* fire off the request */ 439 /* XXX this had better not be a low level drive */ 440 dev_dstrategy(dev, &rqe->b.b_bio1); 441 } 442 } 443 } 444 crit_exit(); 445 return 0; 446 } 447 448 /* 449 * define the low-level requests needed to perform a 450 * high-level I/O operation for a specific plex 'plexno'. 451 * 452 * Return REQUEST_OK if all subdisks involved in the request are up, 453 * REQUEST_DOWN if some subdisks are not up, and REQUEST_EOF if the 454 * request is at least partially outside the bounds of the subdisks. 455 * 456 * Modify the pointer *diskstart to point to the end address. On 457 * read, return on the first bad subdisk, so that the caller 458 * (build_read_request) can try alternatives. 459 * 460 * On entry to this routine, the rqg structures are not assigned. The 461 * assignment is performed by expandrq(). Strictly speaking, the 462 * elements rqe->sdno of all entries should be set to -1, since 0 463 * (from bzero) is a valid subdisk number. We avoid this problem by 464 * initializing the ones we use, and not looking at the others (index 465 * >= rqg->requests). 466 */ 467 enum requeststatus 468 bre(struct request *rq, 469 int plexno, 470 daddr_t * diskaddr, 471 daddr_t diskend) 472 { 473 int sdno; 474 struct sd *sd; 475 struct rqgroup *rqg; 476 struct bio *bio; 477 struct buf *bp; /* user's bp */ 478 struct plex *plex; 479 enum requeststatus status; /* return value */ 480 daddr_t plexoffset; /* offset of transfer in plex */ 481 daddr_t stripebase; /* base address of stripe (1st subdisk) */ 482 daddr_t stripeoffset; /* offset in stripe */ 483 daddr_t blockoffset; /* offset in stripe on subdisk */ 484 struct rqelement *rqe; /* point to this request information */ 485 daddr_t diskstart = *diskaddr; /* remember where this transfer starts */ 486 enum requeststatus s; /* temp return value */ 487 488 bio = rq->bio; /* buffer pointer */ 489 bp = bio->bio_buf; 490 status = REQUEST_OK; /* return value: OK until proven otherwise */ 491 plex = &PLEX[plexno]; /* point to the plex */ 492 493 switch (plex->organization) { 494 case plex_concat: 495 sd = NULL; /* (keep compiler quiet) */ 496 for (sdno = 0; sdno < plex->subdisks; sdno++) { 497 sd = &SD[plex->sdnos[sdno]]; 498 if (*diskaddr < sd->plexoffset) /* we must have a hole, */ 499 status = REQUEST_DEGRADED; /* note the fact */ 500 if (*diskaddr < (sd->plexoffset + sd->sectors)) { /* the request starts in this subdisk */ 501 rqg = allocrqg(rq, 1); /* space for the request */ 502 if (rqg == NULL) { /* malloc failed */ 503 bp->b_error = ENOMEM; 504 bp->b_flags |= B_ERROR; 505 return REQUEST_ENOMEM; 506 } 507 rqg->plexno = plexno; 508 509 rqe = &rqg->rqe[0]; /* point to the element */ 510 rqe->rqg = rqg; /* group */ 511 rqe->sdno = sd->sdno; /* put in the subdisk number */ 512 plexoffset = *diskaddr; /* start offset in plex */ 513 rqe->sdoffset = plexoffset - sd->plexoffset; /* start offset in subdisk */ 514 rqe->useroffset = plexoffset - diskstart; /* start offset in user buffer */ 515 rqe->dataoffset = 0; 516 rqe->datalen = min(diskend - *diskaddr, /* number of sectors to transfer in this sd */ 517 sd->sectors - rqe->sdoffset); 518 rqe->groupoffset = 0; /* no groups for concatenated plexes */ 519 rqe->grouplen = 0; 520 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ 521 rqe->flags = 0; 522 rqe->driveno = sd->driveno; 523 if (sd->state != sd_up) { /* *now* we find the sd is down */ 524 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ 525 if (s == REQUEST_DOWN) { /* down? */ 526 rqe->flags = XFR_BAD_SUBDISK; /* yup */ 527 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */ 528 return REQUEST_DEGRADED; /* give up here */ 529 /* 530 * If we're writing, don't give up 531 * because of a bad subdisk. Go 532 * through to the bitter end, but note 533 * which ones we can't access. 534 */ 535 status = REQUEST_DEGRADED; /* can't do it all */ 536 } 537 } 538 *diskaddr += rqe->datalen; /* bump the address */ 539 if (build_rq_buffer(rqe, plex)) { /* build the buffer */ 540 deallocrqg(rqg); 541 bp->b_error = ENOMEM; 542 bp->b_flags |= B_ERROR; 543 return REQUEST_ENOMEM; /* can't do it */ 544 } 545 } 546 if (*diskaddr == diskend) /* we're finished, */ 547 break; /* get out of here */ 548 } 549 /* 550 * We've got to the end of the plex. Have we got to the end of 551 * the transfer? It would seem that having an offset beyond the 552 * end of the subdisk is an error, but in fact it can happen if 553 * the volume has another plex of different size. There's a valid 554 * question as to why you would want to do this, but currently 555 * it's allowed. 556 * 557 * In a previous version, I returned REQUEST_DOWN here. I think 558 * REQUEST_EOF is more appropriate now. 559 */ 560 if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */ 561 status = REQUEST_EOF; 562 break; 563 564 case plex_striped: 565 { 566 while (*diskaddr < diskend) { /* until we get it all sorted out */ 567 if (*diskaddr >= plex->length) /* beyond the end of the plex */ 568 return REQUEST_EOF; /* can't continue */ 569 570 /* The offset of the start address from the start of the stripe. */ 571 stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks); 572 573 /* The plex-relative address of the start of the stripe. */ 574 stripebase = *diskaddr - stripeoffset; 575 576 /* The number of the subdisk in which the start is located. */ 577 sdno = stripeoffset / plex->stripesize; 578 579 /* The offset from the beginning of the stripe on this subdisk. */ 580 blockoffset = stripeoffset % plex->stripesize; 581 582 sd = &SD[plex->sdnos[sdno]]; /* the subdisk in question */ 583 rqg = allocrqg(rq, 1); /* space for the request */ 584 if (rqg == NULL) { /* malloc failed */ 585 bp->b_error = ENOMEM; 586 bp->b_flags |= B_ERROR; 587 return REQUEST_ENOMEM; 588 } 589 rqg->plexno = plexno; 590 591 rqe = &rqg->rqe[0]; /* point to the element */ 592 rqe->rqg = rqg; 593 rqe->sdoffset = stripebase / plex->subdisks + blockoffset; /* start offset in this subdisk */ 594 rqe->useroffset = *diskaddr - diskstart; /* The offset of the start in the user buffer */ 595 rqe->dataoffset = 0; 596 rqe->datalen = min(diskend - *diskaddr, /* the amount remaining to transfer */ 597 plex->stripesize - blockoffset); /* and the amount left in this stripe */ 598 rqe->groupoffset = 0; /* no groups for striped plexes */ 599 rqe->grouplen = 0; 600 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ 601 rqe->flags = 0; 602 rqe->sdno = sd->sdno; /* put in the subdisk number */ 603 rqe->driveno = sd->driveno; 604 605 if (sd->state != sd_up) { /* *now* we find the sd is down */ 606 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ 607 if (s == REQUEST_DOWN) { /* down? */ 608 rqe->flags = XFR_BAD_SUBDISK; /* yup */ 609 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */ 610 return REQUEST_DEGRADED; /* give up here */ 611 /* 612 * If we're writing, don't give up 613 * because of a bad subdisk. Go through 614 * to the bitter end, but note which 615 * ones we can't access. 616 */ 617 status = REQUEST_DEGRADED; /* can't do it all */ 618 } 619 } 620 /* 621 * It would seem that having an offset 622 * beyond the end of the subdisk is an 623 * error, but in fact it can happen if the 624 * volume has another plex of different 625 * size. There's a valid question as to why 626 * you would want to do this, but currently 627 * it's allowed. 628 */ 629 if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */ 630 rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */ 631 #if VINUMDEBUG 632 if (debug & DEBUG_EOFINFO) { /* tell on the request */ 633 log(LOG_DEBUG, 634 "vinum: EOF on plex %s, sd %s offset %jx (user offset %jx)\n", 635 plex->name, 636 sd->name, 637 (uintmax_t)sd->sectors, 638 (uintmax_t)bp->b_bio1.bio_offset); 639 log(LOG_DEBUG, 640 "vinum: stripebase %x, stripeoffset %x, blockoffset %x\n", 641 stripebase, 642 stripeoffset, 643 blockoffset); 644 } 645 #endif 646 } 647 if (build_rq_buffer(rqe, plex)) { /* build the buffer */ 648 deallocrqg(rqg); 649 bp->b_error = ENOMEM; 650 bp->b_flags |= B_ERROR; 651 return REQUEST_ENOMEM; /* can't do it */ 652 } 653 *diskaddr += rqe->datalen; /* look at the remainder */ 654 if ((*diskaddr < diskend) /* didn't finish the request on this stripe */ 655 &&(*diskaddr < plex->length)) { /* and there's more to come */ 656 plex->multiblock++; /* count another one */ 657 if (sdno == plex->subdisks - 1) /* last subdisk, */ 658 plex->multistripe++; /* another stripe as well */ 659 } 660 } 661 } 662 break; 663 664 /* 665 * RAID-4 and RAID-5 are complicated enough to have their own 666 * function. 667 */ 668 case plex_raid4: 669 case plex_raid5: 670 status = bre5(rq, plexno, diskaddr, diskend); 671 break; 672 673 default: 674 log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization); 675 status = REQUEST_DOWN; /* can't access it */ 676 } 677 678 return status; 679 } 680 681 /* 682 * Build up a request structure for reading volumes. 683 * This function is not needed for plex reads, since there's 684 * no recovery if a plex read can't be satisified. 685 */ 686 enum requeststatus 687 build_read_request(struct request *rq, /* request */ 688 int plexindex) 689 { /* index in the volume's plex table */ 690 struct bio *bio; 691 struct buf *bp; 692 daddr_t startaddr; /* offset of previous part of transfer */ 693 daddr_t diskaddr; /* offset of current part of transfer */ 694 daddr_t diskend; /* and end offset of transfer */ 695 int plexno; /* plex index in vinum_conf */ 696 struct rqgroup *rqg; /* point to the request we're working on */ 697 struct volume *vol; /* volume in question */ 698 int recovered = 0; /* set if we recover a read */ 699 enum requeststatus status = REQUEST_OK; 700 int plexmask; /* bit mask of plexes, for recovery */ 701 702 bio = rq->bio; /* buffer pointer */ 703 bp = bio->bio_buf; 704 diskaddr = bio->bio_offset >> DEV_BSHIFT; /* start offset of transfer */ 705 diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */ 706 rqg = &rq->rqg[plexindex]; /* plex request */ 707 vol = &VOL[rq->volplex.volno]; /* point to volume */ 708 709 while (diskaddr < diskend) { /* build up request components */ 710 startaddr = diskaddr; 711 status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */ 712 switch (status) { 713 case REQUEST_OK: 714 continue; 715 716 case REQUEST_RECOVERED: 717 /* 718 * XXX FIXME if we have more than one plex, and we can 719 * satisfy the request from another, don't use the 720 * recovered request, since it's more expensive. 721 */ 722 recovered = 1; 723 break; 724 725 case REQUEST_ENOMEM: 726 return status; 727 /* 728 * If we get here, our request is not complete. Try 729 * to fill in the missing parts from another plex. 730 * This can happen multiple times in this function, 731 * and we reinitialize the plex mask each time, since 732 * we could have a hole in our plexes. 733 */ 734 case REQUEST_EOF: 735 case REQUEST_DOWN: /* can't access the plex */ 736 case REQUEST_DEGRADED: /* can't access the plex */ 737 plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */ 738 &~(1 << plexindex); /* except for the one we were looking at */ 739 for (plexno = 0; plexno < vol->plexes; plexno++) { 740 if (plexmask == 0) /* no plexes left to try */ 741 return REQUEST_DOWN; /* failed */ 742 diskaddr = startaddr; /* start at the beginning again */ 743 if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */ 744 bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */ 745 if (diskaddr > startaddr) { /* we satisfied another part */ 746 recovered = 1; /* we recovered from the problem */ 747 status = REQUEST_OK; /* don't complain about it */ 748 break; 749 } 750 } 751 } 752 if (diskaddr == startaddr) /* didn't get any further, */ 753 return status; 754 } 755 if (recovered) 756 vol->recovered_reads += recovered; /* adjust our recovery count */ 757 } 758 return status; 759 } 760 761 /* 762 * Build up a request structure for writes. 763 * Return 0 if all subdisks involved in the request are up, 1 if some 764 * subdisks are not up, and -1 if the request is at least partially 765 * outside the bounds of the subdisks. 766 */ 767 enum requeststatus 768 build_write_request(struct request *rq) 769 { /* request */ 770 struct bio *bio; 771 struct buf *bp; 772 daddr_t diskstart; /* offset of current part of transfer */ 773 daddr_t diskend; /* and end offset of transfer */ 774 int plexno; /* plex index in vinum_conf */ 775 struct volume *vol; /* volume in question */ 776 enum requeststatus status; 777 778 bio = rq->bio; /* buffer pointer */ 779 bp = bio->bio_buf; 780 vol = &VOL[rq->volplex.volno]; /* point to volume */ 781 diskend = (daddr_t)(bio->bio_offset >> DEV_BSHIFT) + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */ 782 status = REQUEST_DOWN; /* assume the worst */ 783 for (plexno = 0; plexno < vol->plexes; plexno++) { 784 diskstart = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */ 785 /* 786 * Build requests for the plex. 787 * We take the best possible result here (min, 788 * not max): we're happy if we can write at all 789 */ 790 status = min(status, bre(rq, 791 vol->plex[plexno], 792 &diskstart, 793 diskend)); 794 } 795 return status; 796 } 797 798 /* Fill in the struct buf part of a request element. */ 799 enum requeststatus 800 build_rq_buffer(struct rqelement *rqe, struct plex *plex) 801 { 802 struct sd *sd; /* point to subdisk */ 803 struct volume *vol; 804 struct buf *bp; 805 struct buf *ubp; /* user (high level) buffer header */ 806 struct bio *ubio; 807 808 vol = &VOL[rqe->rqg->rq->volplex.volno]; 809 sd = &SD[rqe->sdno]; /* point to subdisk */ 810 bp = &rqe->b; 811 ubio = rqe->rqg->rq->bio; /* pointer to user buffer header */ 812 ubp = ubio->bio_buf; 813 814 /* Initialize the buf struct */ 815 /* copy these flags from user bp */ 816 bp->b_flags = ubp->b_flags & (B_ORDERED | B_NOCACHE | B_ASYNC); 817 bp->b_cmd = ubp->b_cmd; 818 #ifdef VINUMDEBUG 819 if (rqe->flags & XFR_BUFLOCKED) /* paranoia */ 820 panic("build_rq_buffer: rqe already locked"); /* XXX remove this when we're sure */ 821 #endif 822 BUF_LOCKINIT(bp); /* get a lock for the buffer */ 823 BUF_LOCK(bp, LK_EXCLUSIVE); /* and lock it */ 824 BUF_KERNPROC(bp); 825 initbufbio(bp); 826 rqe->flags |= XFR_BUFLOCKED; 827 bp->b_bio1.bio_done = complete_rqe; 828 /* 829 * You'd think that we wouldn't need to even 830 * build the request buffer for a dead subdisk, 831 * but in some cases we need information like 832 * the user buffer address. Err on the side of 833 * generosity and supply what we can. That 834 * obviously doesn't include drive information 835 * when the drive is dead. 836 */ 837 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) /* subdisk is accessible, */ 838 bp->b_bio1.bio_driver_info = DRIVE[rqe->driveno].dev; /* drive device */ 839 bp->b_bio1.bio_offset = (off_t)(rqe->sdoffset + sd->driveoffset) << DEV_BSHIFT; /* start address */ 840 bp->b_bcount = rqe->buflen << DEV_BSHIFT; /* number of bytes to transfer */ 841 bp->b_resid = bp->b_bcount; /* and it's still all waiting */ 842 843 if (rqe->flags & XFR_MALLOCED) { /* this operation requires a malloced buffer */ 844 bp->b_data = Malloc(bp->b_bcount); /* get a buffer to put it in */ 845 if (bp->b_data == NULL) { /* failed */ 846 abortrequest(rqe->rqg->rq, ENOMEM); 847 return REQUEST_ENOMEM; /* no memory */ 848 } 849 } else 850 /* 851 * Point directly to user buffer data. This means 852 * that we don't need to do anything when we have 853 * finished the transfer 854 */ 855 bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE; 856 /* 857 * On a recovery read, we perform an XOR of 858 * all blocks to the user buffer. To make 859 * this work, we first clean out the buffer 860 */ 861 if ((rqe->flags & (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) 862 == (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) { /* bad subdisk of a recovery read */ 863 int length = rqe->grouplen << DEV_BSHIFT; /* and count involved */ 864 char *data = (char *) &rqe->b.b_data[rqe->groupoffset << DEV_BSHIFT]; /* destination */ 865 866 bzero(data, length); /* clean it out */ 867 } 868 return 0; 869 } 870 871 /* 872 * Abort a request: free resources and complete the 873 * user request with the specified error 874 */ 875 int 876 abortrequest(struct request *rq, int error) 877 { 878 struct buf *bp = rq->bio->bio_buf; /* user buffer */ 879 880 bp->b_error = error; 881 freerq(rq); /* free everything we're doing */ 882 bp->b_flags |= B_ERROR; 883 return error; /* and give up */ 884 } 885 886 /* 887 * Check that our transfer will cover the 888 * complete address space of the user request. 889 * 890 * Return 1 if it can, otherwise 0 891 */ 892 int 893 check_range_covered(struct request *rq) 894 { 895 return 1; 896 } 897 898 /* Perform I/O on a subdisk */ 899 void 900 sdio(struct bio *bio) 901 { 902 cdev_t dev; 903 struct sd *sd; 904 struct sdbuf *sbp; 905 daddr_t endoffset; 906 struct drive *drive; 907 struct buf *bp = bio->bio_buf; 908 909 dev = bio->bio_driver_info; 910 911 #if VINUMDEBUG 912 if (debug & DEBUG_LASTREQS) 913 logrq(loginfo_sdio, (union rqinfou) bio, bio); 914 #endif 915 sd = &SD[Sdno(dev)]; /* point to the subdisk */ 916 drive = &DRIVE[sd->driveno]; 917 918 if (drive->state != drive_up) { 919 if (sd->state >= sd_crashed) { 920 if (bp->b_cmd != BUF_CMD_READ) /* writing, */ 921 set_sd_state(sd->sdno, sd_stale, setstate_force); 922 else 923 set_sd_state(sd->sdno, sd_crashed, setstate_force); 924 } 925 bp->b_error = EIO; 926 bp->b_flags |= B_ERROR; 927 biodone(bio); 928 return; 929 } 930 /* 931 * We allow access to any kind of subdisk as long as we can expect 932 * to get the I/O performed. 933 */ 934 if (sd->state < sd_empty) { /* nothing to talk to, */ 935 bp->b_error = EIO; 936 bp->b_flags |= B_ERROR; 937 biodone(bio); 938 return; 939 } 940 /* Get a buffer */ 941 sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf)); 942 if (sbp == NULL) { 943 bp->b_error = ENOMEM; 944 bp->b_flags |= B_ERROR; 945 biodone(bio); 946 return; 947 } 948 bzero(sbp, sizeof(struct sdbuf)); /* start with nothing */ 949 sbp->b.b_cmd = bp->b_cmd; 950 sbp->b.b_bcount = bp->b_bcount; /* number of bytes to transfer */ 951 sbp->b.b_resid = bp->b_resid; /* and amount waiting */ 952 sbp->b.b_data = bp->b_data; /* data buffer */ 953 BUF_LOCKINIT(&sbp->b); /* get a lock for the buffer */ 954 BUF_LOCK(&sbp->b, LK_EXCLUSIVE); /* and lock it */ 955 BUF_KERNPROC(&sbp->b); 956 initbufbio(&sbp->b); 957 sbp->b.b_bio1.bio_offset = bio->bio_offset + ((off_t)sd->driveoffset << DEV_BSHIFT); 958 sbp->b.b_bio1.bio_done = sdio_done; /* come here on completion */ 959 sbp->bio = bio; /* note the address of the original header */ 960 sbp->sdno = sd->sdno; /* note for statistics */ 961 sbp->driveno = sd->driveno; 962 endoffset = (daddr_t)(bio->bio_offset >> DEV_BSHIFT) + sbp->b.b_bcount / DEV_BSIZE; /* final sector offset */ 963 if (endoffset > sd->sectors) { /* beyond the end */ 964 sbp->b.b_bcount -= (endoffset - sd->sectors) * DEV_BSIZE; /* trim */ 965 if (sbp->b.b_bcount <= 0) { /* nothing to transfer */ 966 bp->b_resid = bp->b_bcount; /* nothing transferred */ 967 biodone(bio); 968 BUF_UNLOCK(&sbp->b); 969 BUF_LOCKFREE(&sbp->b); 970 Free(sbp); 971 return; 972 } 973 } 974 #if VINUMDEBUG 975 if (debug & DEBUG_ADDRESSES) 976 log(LOG_DEBUG, 977 " %s dev %s, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n", 978 (sbp->b.b_cmd == BUF_CMD_READ) ? "Read" : "Write", 979 drive->devicename, 980 sbp->sdno, 981 sbp->b.b_bio1.bio_offset - ((off_t)SD[sbp->sdno].driveoffset << DEV_BSHIFT), 982 sbp->b.b_bio1.bio_offset, 983 sbp->b.b_bcount); 984 #endif 985 crit_enter(); 986 #if VINUMDEBUG 987 if (debug & DEBUG_LASTREQS) 988 logrq(loginfo_sdiol, (union rqinfou) &sbp->b.b_bio1, &sbp->b.b_bio1); 989 #endif 990 vn_strategy(drive->vp, &sbp->b.b_bio1); 991 crit_exit(); 992 } 993 994 /* 995 * Determine the size of the transfer, and make sure it is 996 * within the boundaries of the partition. Adjust transfer 997 * if needed, and signal errors or early completion. 998 * 999 * Volumes are simpler than disk slices: they only contain 1000 * one component (though we call them a, b and c to make 1001 * system utilities happy), and they always take up the 1002 * complete space of the "partition". 1003 * 1004 * I'm still not happy with this: why should the label be 1005 * protected? If it weren't so damned difficult to write 1006 * one in the first pleace (because it's protected), it wouldn't 1007 * be a problem. 1008 */ 1009 struct bio * 1010 vinum_bounds_check(struct bio *bio, struct volume *vol) 1011 { 1012 struct buf *bp = bio->bio_buf; 1013 struct bio *nbio; 1014 int maxsize = vol->size; /* size of the partition (sectors) */ 1015 int size = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* size of this request (sectors) */ 1016 daddr_t blkno = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); 1017 1018 if (size == 0) /* no transfer specified, */ 1019 return 0; /* treat as EOF */ 1020 /* beyond partition? */ 1021 if (bio->bio_offset < 0 /* negative start */ 1022 || blkno + size > maxsize) { /* or goes beyond the end of the partition */ 1023 /* if exactly at end of disk, return an EOF */ 1024 if (blkno == maxsize) { 1025 bp->b_resid = bp->b_bcount; 1026 return (NULL); 1027 } 1028 /* or truncate if part of it fits */ 1029 size = maxsize - blkno; 1030 if (size <= 0) { /* nothing to transfer */ 1031 bp->b_error = EINVAL; 1032 bp->b_flags |= B_ERROR; 1033 return (NULL); 1034 } 1035 bp->b_bcount = size << DEV_BSHIFT; 1036 } 1037 nbio = push_bio(bio); 1038 nbio->bio_offset = bio->bio_offset; 1039 return (nbio); 1040 } 1041 1042 /* 1043 * Allocate a request group and hook 1044 * it in in the list for rq 1045 */ 1046 struct rqgroup * 1047 allocrqg(struct request *rq, int elements) 1048 { 1049 struct rqgroup *rqg; /* the one we're going to allocate */ 1050 int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement); 1051 1052 rqg = (struct rqgroup *) Malloc(size); 1053 if (rqg != NULL) { /* malloc OK, */ 1054 if (rq->rqg) /* we already have requests */ 1055 rq->lrqg->next = rqg; /* hang it off the end */ 1056 else /* first request */ 1057 rq->rqg = rqg; /* at the start */ 1058 rq->lrqg = rqg; /* this one is the last in the list */ 1059 1060 bzero(rqg, size); /* no old junk */ 1061 rqg->rq = rq; /* point back to the parent request */ 1062 rqg->count = elements; /* number of requests in the group */ 1063 rqg->lockbase = -1; /* no lock required yet */ 1064 } 1065 return rqg; 1066 } 1067 1068 /* 1069 * Deallocate a request group out of a chain. We do 1070 * this by linear search: the chain is short, this 1071 * almost never happens, and currently it can only 1072 * happen to the first member of the chain. 1073 */ 1074 void 1075 deallocrqg(struct rqgroup *rqg) 1076 { 1077 struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */ 1078 1079 if (rqg->lock) /* got a lock? */ 1080 unlockrange(rqg->plexno, rqg->lock); /* yes, free it */ 1081 if (rqgc == rqg) /* we're first in line */ 1082 rqg->rq->rqg = rqg->next; /* unhook ourselves */ 1083 else { 1084 while ((rqgc->next != NULL) /* find the group */ 1085 &&(rqgc->next != rqg)) 1086 rqgc = rqgc->next; 1087 if (rqgc->next == NULL) 1088 log(LOG_ERR, 1089 "vinum deallocrqg: rqg %p not found in request %p\n", 1090 rqg->rq, 1091 rqg); 1092 else 1093 rqgc->next = rqg->next; /* make the chain jump over us */ 1094 } 1095 Free(rqg); 1096 } 1097 1098 /* Local Variables: */ 1099 /* fill-column: 50 */ 1100 /* End: */ 1101