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 1.17 2006/09/10 01:26:36 dillon 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 dev_dstrategy(dev, &rqe->b.b_bio1); 440 } 441 } 442 } 443 crit_exit(); 444 return 0; 445 } 446 447 /* 448 * define the low-level requests needed to perform a 449 * high-level I/O operation for a specific plex 'plexno'. 450 * 451 * Return REQUEST_OK if all subdisks involved in the request are up, 452 * REQUEST_DOWN if some subdisks are not up, and REQUEST_EOF if the 453 * request is at least partially outside the bounds of the subdisks. 454 * 455 * Modify the pointer *diskstart to point to the end address. On 456 * read, return on the first bad subdisk, so that the caller 457 * (build_read_request) can try alternatives. 458 * 459 * On entry to this routine, the rqg structures are not assigned. The 460 * assignment is performed by expandrq(). Strictly speaking, the 461 * elements rqe->sdno of all entries should be set to -1, since 0 462 * (from bzero) is a valid subdisk number. We avoid this problem by 463 * initializing the ones we use, and not looking at the others (index 464 * >= rqg->requests). 465 */ 466 enum requeststatus 467 bre(struct request *rq, 468 int plexno, 469 daddr_t * diskaddr, 470 daddr_t diskend) 471 { 472 int sdno; 473 struct sd *sd; 474 struct rqgroup *rqg; 475 struct bio *bio; 476 struct buf *bp; /* user's bp */ 477 struct plex *plex; 478 enum requeststatus status; /* return value */ 479 daddr_t plexoffset; /* offset of transfer in plex */ 480 daddr_t stripebase; /* base address of stripe (1st subdisk) */ 481 daddr_t stripeoffset; /* offset in stripe */ 482 daddr_t blockoffset; /* offset in stripe on subdisk */ 483 struct rqelement *rqe; /* point to this request information */ 484 daddr_t diskstart = *diskaddr; /* remember where this transfer starts */ 485 enum requeststatus s; /* temp return value */ 486 487 bio = rq->bio; /* buffer pointer */ 488 bp = bio->bio_buf; 489 status = REQUEST_OK; /* return value: OK until proven otherwise */ 490 plex = &PLEX[plexno]; /* point to the plex */ 491 492 switch (plex->organization) { 493 case plex_concat: 494 sd = NULL; /* (keep compiler quiet) */ 495 for (sdno = 0; sdno < plex->subdisks; sdno++) { 496 sd = &SD[plex->sdnos[sdno]]; 497 if (*diskaddr < sd->plexoffset) /* we must have a hole, */ 498 status = REQUEST_DEGRADED; /* note the fact */ 499 if (*diskaddr < (sd->plexoffset + sd->sectors)) { /* the request starts in this subdisk */ 500 rqg = allocrqg(rq, 1); /* space for the request */ 501 if (rqg == NULL) { /* malloc failed */ 502 bp->b_error = ENOMEM; 503 bp->b_flags |= B_ERROR; 504 return REQUEST_ENOMEM; 505 } 506 rqg->plexno = plexno; 507 508 rqe = &rqg->rqe[0]; /* point to the element */ 509 rqe->rqg = rqg; /* group */ 510 rqe->sdno = sd->sdno; /* put in the subdisk number */ 511 plexoffset = *diskaddr; /* start offset in plex */ 512 rqe->sdoffset = plexoffset - sd->plexoffset; /* start offset in subdisk */ 513 rqe->useroffset = plexoffset - diskstart; /* start offset in user buffer */ 514 rqe->dataoffset = 0; 515 rqe->datalen = min(diskend - *diskaddr, /* number of sectors to transfer in this sd */ 516 sd->sectors - rqe->sdoffset); 517 rqe->groupoffset = 0; /* no groups for concatenated plexes */ 518 rqe->grouplen = 0; 519 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ 520 rqe->flags = 0; 521 rqe->driveno = sd->driveno; 522 if (sd->state != sd_up) { /* *now* we find the sd is down */ 523 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ 524 if (s == REQUEST_DOWN) { /* down? */ 525 rqe->flags = XFR_BAD_SUBDISK; /* yup */ 526 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */ 527 return REQUEST_DEGRADED; /* give up here */ 528 /* 529 * If we're writing, don't give up 530 * because of a bad subdisk. Go 531 * through to the bitter end, but note 532 * which ones we can't access. 533 */ 534 status = REQUEST_DEGRADED; /* can't do it all */ 535 } 536 } 537 *diskaddr += rqe->datalen; /* bump the address */ 538 if (build_rq_buffer(rqe, plex)) { /* build the buffer */ 539 deallocrqg(rqg); 540 bp->b_error = ENOMEM; 541 bp->b_flags |= B_ERROR; 542 return REQUEST_ENOMEM; /* can't do it */ 543 } 544 } 545 if (*diskaddr == diskend) /* we're finished, */ 546 break; /* get out of here */ 547 } 548 /* 549 * We've got to the end of the plex. Have we got to the end of 550 * the transfer? It would seem that having an offset beyond the 551 * end of the subdisk is an error, but in fact it can happen if 552 * the volume has another plex of different size. There's a valid 553 * question as to why you would want to do this, but currently 554 * it's allowed. 555 * 556 * In a previous version, I returned REQUEST_DOWN here. I think 557 * REQUEST_EOF is more appropriate now. 558 */ 559 if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */ 560 status = REQUEST_EOF; 561 break; 562 563 case plex_striped: 564 { 565 while (*diskaddr < diskend) { /* until we get it all sorted out */ 566 if (*diskaddr >= plex->length) /* beyond the end of the plex */ 567 return REQUEST_EOF; /* can't continue */ 568 569 /* The offset of the start address from the start of the stripe. */ 570 stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks); 571 572 /* The plex-relative address of the start of the stripe. */ 573 stripebase = *diskaddr - stripeoffset; 574 575 /* The number of the subdisk in which the start is located. */ 576 sdno = stripeoffset / plex->stripesize; 577 578 /* The offset from the beginning of the stripe on this subdisk. */ 579 blockoffset = stripeoffset % plex->stripesize; 580 581 sd = &SD[plex->sdnos[sdno]]; /* the subdisk in question */ 582 rqg = allocrqg(rq, 1); /* space for the request */ 583 if (rqg == NULL) { /* malloc failed */ 584 bp->b_error = ENOMEM; 585 bp->b_flags |= B_ERROR; 586 return REQUEST_ENOMEM; 587 } 588 rqg->plexno = plexno; 589 590 rqe = &rqg->rqe[0]; /* point to the element */ 591 rqe->rqg = rqg; 592 rqe->sdoffset = stripebase / plex->subdisks + blockoffset; /* start offset in this subdisk */ 593 rqe->useroffset = *diskaddr - diskstart; /* The offset of the start in the user buffer */ 594 rqe->dataoffset = 0; 595 rqe->datalen = min(diskend - *diskaddr, /* the amount remaining to transfer */ 596 plex->stripesize - blockoffset); /* and the amount left in this stripe */ 597 rqe->groupoffset = 0; /* no groups for striped plexes */ 598 rqe->grouplen = 0; 599 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ 600 rqe->flags = 0; 601 rqe->sdno = sd->sdno; /* put in the subdisk number */ 602 rqe->driveno = sd->driveno; 603 604 if (sd->state != sd_up) { /* *now* we find the sd is down */ 605 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ 606 if (s == REQUEST_DOWN) { /* down? */ 607 rqe->flags = XFR_BAD_SUBDISK; /* yup */ 608 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */ 609 return REQUEST_DEGRADED; /* give up here */ 610 /* 611 * If we're writing, don't give up 612 * because of a bad subdisk. Go through 613 * to the bitter end, but note which 614 * ones we can't access. 615 */ 616 status = REQUEST_DEGRADED; /* can't do it all */ 617 } 618 } 619 /* 620 * It would seem that having an offset 621 * beyond the end of the subdisk is an 622 * error, but in fact it can happen if the 623 * volume has another plex of different 624 * size. There's a valid question as to why 625 * you would want to do this, but currently 626 * it's allowed. 627 */ 628 if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */ 629 rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */ 630 #if VINUMDEBUG 631 if (debug & DEBUG_EOFINFO) { /* tell on the request */ 632 log(LOG_DEBUG, 633 "vinum: EOF on plex %s, sd %s offset %llx (user offset %x)\n", 634 plex->name, 635 sd->name, 636 (u_int) sd->sectors, 637 bp->b_bio1.bio_offset); 638 log(LOG_DEBUG, 639 "vinum: stripebase %x, stripeoffset %x, blockoffset %x\n", 640 stripebase, 641 stripeoffset, 642 blockoffset); 643 } 644 #endif 645 } 646 if (build_rq_buffer(rqe, plex)) { /* build the buffer */ 647 deallocrqg(rqg); 648 bp->b_error = ENOMEM; 649 bp->b_flags |= B_ERROR; 650 return REQUEST_ENOMEM; /* can't do it */ 651 } 652 *diskaddr += rqe->datalen; /* look at the remainder */ 653 if ((*diskaddr < diskend) /* didn't finish the request on this stripe */ 654 &&(*diskaddr < plex->length)) { /* and there's more to come */ 655 plex->multiblock++; /* count another one */ 656 if (sdno == plex->subdisks - 1) /* last subdisk, */ 657 plex->multistripe++; /* another stripe as well */ 658 } 659 } 660 } 661 break; 662 663 /* 664 * RAID-4 and RAID-5 are complicated enough to have their own 665 * function. 666 */ 667 case plex_raid4: 668 case plex_raid5: 669 status = bre5(rq, plexno, diskaddr, diskend); 670 break; 671 672 default: 673 log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization); 674 status = REQUEST_DOWN; /* can't access it */ 675 } 676 677 return status; 678 } 679 680 /* 681 * Build up a request structure for reading volumes. 682 * This function is not needed for plex reads, since there's 683 * no recovery if a plex read can't be satisified. 684 */ 685 enum requeststatus 686 build_read_request(struct request *rq, /* request */ 687 int plexindex) 688 { /* index in the volume's plex table */ 689 struct bio *bio; 690 struct buf *bp; 691 daddr_t startaddr; /* offset of previous part of transfer */ 692 daddr_t diskaddr; /* offset of current part of transfer */ 693 daddr_t diskend; /* and end offset of transfer */ 694 int plexno; /* plex index in vinum_conf */ 695 struct rqgroup *rqg; /* point to the request we're working on */ 696 struct volume *vol; /* volume in question */ 697 int recovered = 0; /* set if we recover a read */ 698 enum requeststatus status = REQUEST_OK; 699 int plexmask; /* bit mask of plexes, for recovery */ 700 701 bio = rq->bio; /* buffer pointer */ 702 bp = bio->bio_buf; 703 diskaddr = bio->bio_offset >> DEV_BSHIFT; /* start offset of transfer */ 704 diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */ 705 rqg = &rq->rqg[plexindex]; /* plex request */ 706 vol = &VOL[rq->volplex.volno]; /* point to volume */ 707 708 while (diskaddr < diskend) { /* build up request components */ 709 startaddr = diskaddr; 710 status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */ 711 switch (status) { 712 case REQUEST_OK: 713 continue; 714 715 case REQUEST_RECOVERED: 716 /* 717 * XXX FIXME if we have more than one plex, and we can 718 * satisfy the request from another, don't use the 719 * recovered request, since it's more expensive. 720 */ 721 recovered = 1; 722 break; 723 724 case REQUEST_ENOMEM: 725 return status; 726 /* 727 * If we get here, our request is not complete. Try 728 * to fill in the missing parts from another plex. 729 * This can happen multiple times in this function, 730 * and we reinitialize the plex mask each time, since 731 * we could have a hole in our plexes. 732 */ 733 case REQUEST_EOF: 734 case REQUEST_DOWN: /* can't access the plex */ 735 case REQUEST_DEGRADED: /* can't access the plex */ 736 plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */ 737 &~(1 << plexindex); /* except for the one we were looking at */ 738 for (plexno = 0; plexno < vol->plexes; plexno++) { 739 if (plexmask == 0) /* no plexes left to try */ 740 return REQUEST_DOWN; /* failed */ 741 diskaddr = startaddr; /* start at the beginning again */ 742 if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */ 743 bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */ 744 if (diskaddr > startaddr) { /* we satisfied another part */ 745 recovered = 1; /* we recovered from the problem */ 746 status = REQUEST_OK; /* don't complain about it */ 747 break; 748 } 749 } 750 } 751 if (diskaddr == startaddr) /* didn't get any further, */ 752 return status; 753 } 754 if (recovered) 755 vol->recovered_reads += recovered; /* adjust our recovery count */ 756 } 757 return status; 758 } 759 760 /* 761 * Build up a request structure for writes. 762 * Return 0 if all subdisks involved in the request are up, 1 if some 763 * subdisks are not up, and -1 if the request is at least partially 764 * outside the bounds of the subdisks. 765 */ 766 enum requeststatus 767 build_write_request(struct request *rq) 768 { /* request */ 769 struct bio *bio; 770 struct buf *bp; 771 daddr_t diskstart; /* offset of current part of transfer */ 772 daddr_t diskend; /* and end offset of transfer */ 773 int plexno; /* plex index in vinum_conf */ 774 struct volume *vol; /* volume in question */ 775 enum requeststatus status; 776 777 bio = rq->bio; /* buffer pointer */ 778 bp = bio->bio_buf; 779 vol = &VOL[rq->volplex.volno]; /* point to volume */ 780 diskend = (daddr_t)(bio->bio_offset >> DEV_BSHIFT) + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */ 781 status = REQUEST_DOWN; /* assume the worst */ 782 for (plexno = 0; plexno < vol->plexes; plexno++) { 783 diskstart = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */ 784 /* 785 * Build requests for the plex. 786 * We take the best possible result here (min, 787 * not max): we're happy if we can write at all 788 */ 789 status = min(status, bre(rq, 790 vol->plex[plexno], 791 &diskstart, 792 diskend)); 793 } 794 return status; 795 } 796 797 /* Fill in the struct buf part of a request element. */ 798 enum requeststatus 799 build_rq_buffer(struct rqelement *rqe, struct plex *plex) 800 { 801 struct sd *sd; /* point to subdisk */ 802 struct volume *vol; 803 struct buf *bp; 804 struct buf *ubp; /* user (high level) buffer header */ 805 struct bio *ubio; 806 807 vol = &VOL[rqe->rqg->rq->volplex.volno]; 808 sd = &SD[rqe->sdno]; /* point to subdisk */ 809 bp = &rqe->b; 810 ubio = rqe->rqg->rq->bio; /* pointer to user buffer header */ 811 ubp = ubio->bio_buf; 812 813 /* Initialize the buf struct */ 814 /* copy these flags from user bp */ 815 bp->b_flags = ubp->b_flags & (B_ORDERED | B_NOCACHE | B_ASYNC); 816 bp->b_cmd = ubp->b_cmd; 817 #ifdef VINUMDEBUG 818 if (rqe->flags & XFR_BUFLOCKED) /* paranoia */ 819 panic("build_rq_buffer: rqe already locked"); /* XXX remove this when we're sure */ 820 #endif 821 BUF_LOCKINIT(bp); /* get a lock for the buffer */ 822 BUF_LOCK(bp, LK_EXCLUSIVE); /* and lock it */ 823 BUF_KERNPROC(bp); 824 initbufbio(bp); 825 rqe->flags |= XFR_BUFLOCKED; 826 bp->b_bio1.bio_done = complete_rqe; 827 /* 828 * You'd think that we wouldn't need to even 829 * build the request buffer for a dead subdisk, 830 * but in some cases we need information like 831 * the user buffer address. Err on the side of 832 * generosity and supply what we can. That 833 * obviously doesn't include drive information 834 * when the drive is dead. 835 */ 836 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) /* subdisk is accessible, */ 837 bp->b_bio1.bio_driver_info = DRIVE[rqe->driveno].dev; /* drive device */ 838 bp->b_bio1.bio_offset = (off_t)(rqe->sdoffset + sd->driveoffset) << DEV_BSHIFT; /* start address */ 839 bp->b_bcount = rqe->buflen << DEV_BSHIFT; /* number of bytes to transfer */ 840 bp->b_resid = bp->b_bcount; /* and it's still all waiting */ 841 842 if (rqe->flags & XFR_MALLOCED) { /* this operation requires a malloced buffer */ 843 bp->b_data = Malloc(bp->b_bcount); /* get a buffer to put it in */ 844 if (bp->b_data == NULL) { /* failed */ 845 abortrequest(rqe->rqg->rq, ENOMEM); 846 return REQUEST_ENOMEM; /* no memory */ 847 } 848 } else 849 /* 850 * Point directly to user buffer data. This means 851 * that we don't need to do anything when we have 852 * finished the transfer 853 */ 854 bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE; 855 /* 856 * On a recovery read, we perform an XOR of 857 * all blocks to the user buffer. To make 858 * this work, we first clean out the buffer 859 */ 860 if ((rqe->flags & (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) 861 == (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) { /* bad subdisk of a recovery read */ 862 int length = rqe->grouplen << DEV_BSHIFT; /* and count involved */ 863 char *data = (char *) &rqe->b.b_data[rqe->groupoffset << DEV_BSHIFT]; /* destination */ 864 865 bzero(data, length); /* clean it out */ 866 } 867 return 0; 868 } 869 870 /* 871 * Abort a request: free resources and complete the 872 * user request with the specified error 873 */ 874 int 875 abortrequest(struct request *rq, int error) 876 { 877 struct buf *bp = rq->bio->bio_buf; /* user buffer */ 878 879 bp->b_error = error; 880 freerq(rq); /* free everything we're doing */ 881 bp->b_flags |= B_ERROR; 882 return error; /* and give up */ 883 } 884 885 /* 886 * Check that our transfer will cover the 887 * complete address space of the user request. 888 * 889 * Return 1 if it can, otherwise 0 890 */ 891 int 892 check_range_covered(struct request *rq) 893 { 894 return 1; 895 } 896 897 /* Perform I/O on a subdisk */ 898 void 899 sdio(struct bio *bio) 900 { 901 cdev_t dev; 902 cdev_t sddev; 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 sddev = DRIVE[sd->driveno].dev; /* device */ 949 bzero(sbp, sizeof(struct sdbuf)); /* start with nothing */ 950 sbp->b.b_cmd = bp->b_cmd; 951 sbp->b.b_bcount = bp->b_bcount; /* number of bytes to transfer */ 952 sbp->b.b_resid = bp->b_resid; /* and amount waiting */ 953 sbp->b.b_data = bp->b_data; /* data buffer */ 954 BUF_LOCKINIT(&sbp->b); /* get a lock for the buffer */ 955 BUF_LOCK(&sbp->b, LK_EXCLUSIVE); /* and lock it */ 956 BUF_KERNPROC(&sbp->b); 957 initbufbio(&sbp->b); 958 sbp->b.b_bio1.bio_offset = bio->bio_offset + ((off_t)sd->driveoffset << DEV_BSHIFT); 959 sbp->b.b_bio1.bio_done = sdio_done; /* come here on completion */ 960 sbp->bio = bio; /* note the address of the original header */ 961 sbp->sdno = sd->sdno; /* note for statistics */ 962 sbp->driveno = sd->driveno; 963 endoffset = (daddr_t)(bio->bio_offset >> DEV_BSHIFT) + sbp->b.b_bcount / DEV_BSIZE; /* final sector offset */ 964 if (endoffset > sd->sectors) { /* beyond the end */ 965 sbp->b.b_bcount -= (endoffset - sd->sectors) * DEV_BSIZE; /* trim */ 966 if (sbp->b.b_bcount <= 0) { /* nothing to transfer */ 967 bp->b_resid = bp->b_bcount; /* nothing transferred */ 968 biodone(bio); 969 BUF_UNLOCK(&sbp->b); 970 BUF_LOCKFREE(&sbp->b); 971 Free(sbp); 972 return; 973 } 974 } 975 #if VINUMDEBUG 976 if (debug & DEBUG_ADDRESSES) 977 log(LOG_DEBUG, 978 " %s dev %d.%d, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n", 979 (sbp->b.b_cmd == BUF_CMD_READ) ? "Read" : "Write", 980 major(sddev), 981 minor(sddev), 982 sbp->sdno, 983 sbp->b.b_bio1.bio_offset - ((off_t)SD[sbp->sdno].driveoffset << DEV_BSHIFT), 984 sbp->b.b_bio1.bio_offset, 985 sbp->b.b_bcount); 986 #endif 987 crit_enter(); 988 #if VINUMDEBUG 989 if (debug & DEBUG_LASTREQS) 990 logrq(loginfo_sdiol, (union rqinfou) &sbp->b.b_bio1, &sbp->b.b_bio1); 991 #endif 992 dev_dstrategy(sddev, &sbp->b.b_bio1); 993 crit_exit(); 994 } 995 996 /* 997 * Simplified version of bounds_check_with_label 998 * Determine the size of the transfer, and make sure it is 999 * within the boundaries of the partition. Adjust transfer 1000 * if needed, and signal errors or early completion. 1001 * 1002 * Volumes are simpler than disk slices: they only contain 1003 * one component (though we call them a, b and c to make 1004 * system utilities happy), and they always take up the 1005 * complete space of the "partition". 1006 * 1007 * I'm still not happy with this: why should the label be 1008 * protected? If it weren't so damned difficult to write 1009 * one in the first pleace (because it's protected), it wouldn't 1010 * be a problem. 1011 */ 1012 struct bio * 1013 vinum_bounds_check(struct bio *bio, struct volume *vol) 1014 { 1015 struct buf *bp = bio->bio_buf; 1016 struct bio *nbio; 1017 int maxsize = vol->size; /* size of the partition (sectors) */ 1018 int size = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* size of this request (sectors) */ 1019 daddr_t blkno = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); 1020 1021 /* Would this transfer overwrite the disk label? */ 1022 if (blkno <= LABELSECTOR /* starts before or at the label */ 1023 #if LABELSECTOR != 0 1024 && blkno + size > LABELSECTOR /* and finishes after */ 1025 #endif 1026 && (!(vol->flags & VF_RAW)) /* and it's not raw */ 1027 && (bp->b_cmd != BUF_CMD_READ) /* and it's a write */ 1028 &&(!vol->flags & (VF_WLABEL | VF_LABELLING))) { /* and we're not allowed to write the label */ 1029 bp->b_error = EROFS; /* read-only */ 1030 bp->b_flags |= B_ERROR; 1031 return (NULL); 1032 } 1033 if (size == 0) /* no transfer specified, */ 1034 return 0; /* treat as EOF */ 1035 /* beyond partition? */ 1036 if (bio->bio_offset < 0 /* negative start */ 1037 || blkno + size > maxsize) { /* or goes beyond the end of the partition */ 1038 /* if exactly at end of disk, return an EOF */ 1039 if (blkno == maxsize) { 1040 bp->b_resid = bp->b_bcount; 1041 return (NULL); 1042 } 1043 /* or truncate if part of it fits */ 1044 size = maxsize - blkno; 1045 if (size <= 0) { /* nothing to transfer */ 1046 bp->b_error = EINVAL; 1047 bp->b_flags |= B_ERROR; 1048 return (NULL); 1049 } 1050 bp->b_bcount = size << DEV_BSHIFT; 1051 } 1052 nbio = push_bio(bio); 1053 nbio->bio_offset = bio->bio_offset; 1054 return (nbio); 1055 } 1056 1057 /* 1058 * Allocate a request group and hook 1059 * it in in the list for rq 1060 */ 1061 struct rqgroup * 1062 allocrqg(struct request *rq, int elements) 1063 { 1064 struct rqgroup *rqg; /* the one we're going to allocate */ 1065 int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement); 1066 1067 rqg = (struct rqgroup *) Malloc(size); 1068 if (rqg != NULL) { /* malloc OK, */ 1069 if (rq->rqg) /* we already have requests */ 1070 rq->lrqg->next = rqg; /* hang it off the end */ 1071 else /* first request */ 1072 rq->rqg = rqg; /* at the start */ 1073 rq->lrqg = rqg; /* this one is the last in the list */ 1074 1075 bzero(rqg, size); /* no old junk */ 1076 rqg->rq = rq; /* point back to the parent request */ 1077 rqg->count = elements; /* number of requests in the group */ 1078 rqg->lockbase = -1; /* no lock required yet */ 1079 } 1080 return rqg; 1081 } 1082 1083 /* 1084 * Deallocate a request group out of a chain. We do 1085 * this by linear search: the chain is short, this 1086 * almost never happens, and currently it can only 1087 * happen to the first member of the chain. 1088 */ 1089 void 1090 deallocrqg(struct rqgroup *rqg) 1091 { 1092 struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */ 1093 1094 if (rqg->lock) /* got a lock? */ 1095 unlockrange(rqg->plexno, rqg->lock); /* yes, free it */ 1096 if (rqgc == rqg) /* we're first in line */ 1097 rqg->rq->rqg = rqg->next; /* unhook ourselves */ 1098 else { 1099 while ((rqgc->next != NULL) /* find the group */ 1100 &&(rqgc->next != rqg)) 1101 rqgc = rqgc->next; 1102 if (rqgc->next == NULL) 1103 log(LOG_ERR, 1104 "vinum deallocrqg: rqg %p not found in request %p\n", 1105 rqg->rq, 1106 rqg); 1107 else 1108 rqgc->next = rqg->next; /* make the chain jump over us */ 1109 } 1110 Free(rqg); 1111 } 1112 1113 /* Local Variables: */ 1114 /* fill-column: 50 */ 1115 /* End: */ 1116