2 * Copyright (c) 1997, 1998, 1999
3 * Nan Yang Computer Services Limited. All rights reserved.
5 * Parts copyright (c) 1997, 1998 Cybernet Corporation, NetMAX project.
7 * Written by Greg Lehey
9 * This software is distributed under the so-called ``Berkeley
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
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
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.
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.
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 $
47 #include <sys/resourcevar.h>
49 enum requeststatus bre(struct request *rq,
51 vinum_off_t * diskstart,
53 enum requeststatus bre5(struct request *rq,
55 vinum_off_t * diskstart,
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);
71 struct rqinfo rqinfo[RQINFO_SIZE];
72 struct rqinfo *rqip = rqinfo;
75 logrq(enum rqinfo_type type, union rqinfou info, struct bio *ubio)
81 microtime(&rqip->timestamp); /* when did this happen? */
83 rqip->bio = ubio; /* user buffer */
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);
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);
107 case loginfo_lockwait:
110 bcopy(info.lockinfo, &rqip->info.lockinfo, sizeof(struct rangelock));
118 if (rqip >= &rqinfo[RQINFO_SIZE]) /* wrap around */
126 vinumstrategy(struct dev_strategy_args *ap)
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;
135 switch (DEVTYPE(dev)) {
137 case VINUM_RAWSD_TYPE:
138 bio->bio_driver_info = dev;
141 case VINUM_DRIVE_TYPE:
144 * In fact, vinum doesn't handle drives: they're
145 * handled directly by the disk drivers
147 bp->b_error = EIO; /* I/O error */
148 bp->b_flags |= B_ERROR;
152 case VINUM_VOLUME_TYPE: /* volume I/O */
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;
161 nbio = vinum_bounds_check(bio, vol);
167 case VINUM_PLEX_TYPE:
168 case VINUM_RAWPLEX_TYPE:
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
174 bp->b_resid = bp->b_bcount; /* transfer everything */
175 vinumstart(dev, nbio, 0);
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.
192 vinumstart(cdev_t dev, struct bio *bio, int reviveok)
194 struct buf *bp = bio->bio_buf;
196 int maxplex; /* maximum number of plexes to handle */
198 struct request *rq; /* build up our request here */
199 enum requeststatus status;
201 bio->bio_driver_info = dev;
204 if (debug & DEBUG_LASTREQS)
205 logrq(loginfo_user_bp, (union rqinfou) bio, bio);
208 if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */
209 bp->b_error = EINVAL; /* invalid size */
210 bp->b_flags |= B_ERROR;
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;
221 bzero(rq, sizeof(struct request));
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
228 rq->bio = bio; /* and the user buffer struct */
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 */
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 */
242 if (bp->b_cmd == BUF_CMD_READ) {
244 * This is a read request. Decide
245 * which plex to read from.
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
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 */
261 status = build_read_request(rq, plexno); /* build a request */
263 vinum_off_t diskaddr = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT);
264 /* start offset of transfer */
265 status = bre(rq, /* build a request list */
268 diskaddr + (bp->b_bcount / DEV_BSIZE));
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;
280 return launch_requests(rq, reviveok); /* now start the requests if we can */
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.
288 status = build_write_request(rq); /* Not all the subdisks are up */
289 else { /* plex I/O */
290 vinum_off_t diskstart;
293 diskstart = (vinum_off_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 */
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;
307 return launch_requests(rq, reviveok); /* now start the requests if we can */
312 * Call the low-level strategy routines to
313 * perform the requests in a struct request
316 launch_requests(struct request *rq, int reviveok)
319 int rqno; /* loop index */
320 struct rqelement *rqe; /* current element */
322 int rcount; /* request count */
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
331 if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */
332 &&(!reviveok)) { /* and we don't want to do it now, */
334 struct request *waitlist; /* point to the waitlist */
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 */
343 sd->waitlist = rq; /* hook our request at the front */
346 if (debug & DEBUG_REVIVECONFLICT) {
348 "Revive conflict sd %d: %p\n%s dev %d.%d, offset 0x%llx, length %d\n",
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)),
355 rq->bio->bio_buf->b_bcount);
358 return 0; /* and get out of here */
360 rq->active = 0; /* nothing yet */
362 if (debug & DEBUG_ADDRESSES)
364 "Request: %p\n%s dev %d.%d, offset 0x%llx, length %d\n",
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)),
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);
378 * This loop happens without any participation
379 * of the bottom half, so it requires no
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 */
389 if (rqg->active) /* we have at least one active request, */
390 rq->active++; /* one more active request group */
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.
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]);
403 for (rqno = 0; rqno < rcount;) {
406 rqe = &rqg->rqe[rqno];
409 * Point to next rqg before the bottom end
410 * changes the structures.
412 if (++rqno >= rcount)
414 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) { /* this subdisk is good, */
415 drive = &DRIVE[rqe->driveno]; /* look at drive */
417 if (drive->active >= drive->maxactive)
418 drive->maxactive = drive->active;
420 if (vinum_conf.active >= vinum_conf.maxactive)
421 vinum_conf.maxactive = vinum_conf.active;
423 dev = rqe->b.b_bio1.bio_driver_info;
425 if (debug & DEBUG_ADDRESSES)
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",
432 rqe->b.b_bio1.bio_offset - ((off_t)SD[rqe->sdno].driveoffset << DEV_BSHIFT),
433 rqe->b.b_bio1.bio_offset,
435 if (debug & DEBUG_LASTREQS)
436 logrq(loginfo_rqe, (union rqinfou) rqe, rq->bio);
438 /* fire off the request */
439 /* XXX this had better not be a low level drive */
440 dev_dstrategy(dev, &rqe->b.b_bio1);
449 * define the low-level requests needed to perform a
450 * high-level I/O operation for a specific plex 'plexno'.
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.
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.
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
468 bre(struct request *rq,
470 vinum_off_t * diskaddr,
477 struct buf *bp; /* user's bp */
479 enum requeststatus status; /* return value */
480 vinum_off_t plexoffset; /* offset of transfer in plex */
481 vinum_off_t stripebase; /* base address of stripe (1st subdisk) */
482 vinum_off_t stripeoffset; /* offset in stripe */
483 vinum_off_t blockoffset; /* offset in stripe on subdisk */
484 struct rqelement *rqe; /* point to this request information */
485 vinum_off_t diskstart = *diskaddr; /* remember where this transfer starts */
486 enum requeststatus s; /* temp return value */
488 bio = rq->bio; /* buffer pointer */
490 status = REQUEST_OK; /* return value: OK until proven otherwise */
491 plex = &PLEX[plexno]; /* point to the plex */
493 switch (plex->organization) {
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;
507 rqg->plexno = plexno;
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 */
516 rqe->datalen = u64min(diskend - *diskaddr,
517 sd->sectors - rqe->sdoffset);
518 rqe->groupoffset = 0; /* no groups for concatenated plexes */
520 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */
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 */
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.
535 status = REQUEST_DEGRADED; /* can't do it all */
538 *diskaddr += rqe->datalen; /* bump the address */
539 if (build_rq_buffer(rqe, plex)) { /* build the buffer */
541 bp->b_error = ENOMEM;
542 bp->b_flags |= B_ERROR;
543 return REQUEST_ENOMEM; /* can't do it */
546 if (*diskaddr == diskend) /* we're finished, */
547 break; /* get out of here */
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
557 * In a previous version, I returned REQUEST_DOWN here. I think
558 * REQUEST_EOF is more appropriate now.
560 if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */
561 status = REQUEST_EOF;
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 */
570 /* The offset of the start address from the start of the stripe. */
571 stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks);
573 /* The plex-relative address of the start of the stripe. */
574 stripebase = *diskaddr - stripeoffset;
576 /* The number of the subdisk in which the start is located. */
577 sdno = stripeoffset / plex->stripesize;
579 /* The offset from the beginning of the stripe on this subdisk. */
580 blockoffset = stripeoffset % plex->stripesize;
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;
589 rqg->plexno = plexno;
591 rqe = &rqg->rqe[0]; /* point to the element */
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 */
596 rqe->datalen = u64min(diskend - *diskaddr,
597 plex->stripesize - blockoffset);
598 rqe->groupoffset = 0; /* no groups for striped plexes */
600 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */
602 rqe->sdno = sd->sdno; /* put in the subdisk number */
603 rqe->driveno = sd->driveno;
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 */
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.
617 status = REQUEST_DEGRADED; /* can't do it all */
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
629 if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */
630 rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */
632 if (debug & DEBUG_EOFINFO) { /* tell on the request */
634 "vinum: EOF on plex %s, sd %s offset %jx (user offset %jx)\n",
637 (uintmax_t)sd->sectors,
638 (uintmax_t)bp->b_bio1.bio_offset);
640 "vinum: stripebase 0x%llx, stripeoffset 0x%llx, "
641 "blockoffset 0x%llx\n",
642 (long long)stripebase,
643 (long long)stripeoffset,
644 (long long)blockoffset);
648 if (build_rq_buffer(rqe, plex)) { /* build the buffer */
650 bp->b_error = ENOMEM;
651 bp->b_flags |= B_ERROR;
652 return REQUEST_ENOMEM; /* can't do it */
654 *diskaddr += rqe->datalen; /* look at the remainder */
655 if ((*diskaddr < diskend) /* didn't finish the request on this stripe */
656 &&(*diskaddr < plex->length)) { /* and there's more to come */
657 plex->multiblock++; /* count another one */
658 if (sdno == plex->subdisks - 1) /* last subdisk, */
659 plex->multistripe++; /* another stripe as well */
666 * RAID-4 and RAID-5 are complicated enough to have their own
671 status = bre5(rq, plexno, diskaddr, diskend);
675 log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization);
676 status = REQUEST_DOWN; /* can't access it */
683 * Build up a request structure for reading volumes.
684 * This function is not needed for plex reads, since there's
685 * no recovery if a plex read can't be satisified.
688 build_read_request(struct request *rq, /* request */
690 { /* index in the volume's plex table */
693 vinum_off_t startaddr; /* offset of previous part of transfer */
694 vinum_off_t diskaddr; /* offset of current part of transfer */
695 vinum_off_t diskend; /* and end offset of transfer */
696 int plexno; /* plex index in vinum_conf */
697 struct rqgroup *rqg; /* point to the request we're working on */
698 struct volume *vol; /* volume in question */
699 int recovered = 0; /* set if we recover a read */
700 enum requeststatus status = REQUEST_OK;
701 int plexmask; /* bit mask of plexes, for recovery */
703 bio = rq->bio; /* buffer pointer */
705 diskaddr = bio->bio_offset >> DEV_BSHIFT; /* start offset of transfer */
706 diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */
707 rqg = &rq->rqg[plexindex]; /* plex request */
708 vol = &VOL[rq->volplex.volno]; /* point to volume */
710 while (diskaddr < diskend) { /* build up request components */
711 startaddr = diskaddr;
712 status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */
717 case REQUEST_RECOVERED:
719 * XXX FIXME if we have more than one plex, and we can
720 * satisfy the request from another, don't use the
721 * recovered request, since it's more expensive.
729 * If we get here, our request is not complete. Try
730 * to fill in the missing parts from another plex.
731 * This can happen multiple times in this function,
732 * and we reinitialize the plex mask each time, since
733 * we could have a hole in our plexes.
736 case REQUEST_DOWN: /* can't access the plex */
737 case REQUEST_DEGRADED: /* can't access the plex */
738 plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */
739 &~(1 << plexindex); /* except for the one we were looking at */
740 for (plexno = 0; plexno < vol->plexes; plexno++) {
741 if (plexmask == 0) /* no plexes left to try */
742 return REQUEST_DOWN; /* failed */
743 diskaddr = startaddr; /* start at the beginning again */
744 if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */
745 bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */
746 if (diskaddr > startaddr) { /* we satisfied another part */
747 recovered = 1; /* we recovered from the problem */
748 status = REQUEST_OK; /* don't complain about it */
753 if (diskaddr == startaddr) /* didn't get any further, */
757 vol->recovered_reads += recovered; /* adjust our recovery count */
763 * Build up a request structure for writes.
764 * Return 0 if all subdisks involved in the request are up, 1 if some
765 * subdisks are not up, and -1 if the request is at least partially
766 * outside the bounds of the subdisks.
769 build_write_request(struct request *rq)
773 vinum_off_t diskstart; /* offset of current part of transfer */
774 vinum_off_t diskend; /* and end offset of transfer */
775 int plexno; /* plex index in vinum_conf */
776 struct volume *vol; /* volume in question */
777 enum requeststatus status;
779 bio = rq->bio; /* buffer pointer */
781 vol = &VOL[rq->volplex.volno]; /* point to volume */
782 diskend = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT) + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */
783 status = REQUEST_DOWN; /* assume the worst */
784 for (plexno = 0; plexno < vol->plexes; plexno++) {
785 diskstart = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */
787 * Build requests for the plex.
788 * We take the best possible result here (min,
789 * not max): we're happy if we can write at all
791 status = u64min(status,
792 bre(rq, vol->plex[plexno], &diskstart, diskend));
797 /* Fill in the struct buf part of a request element. */
799 build_rq_buffer(struct rqelement *rqe, struct plex *plex)
801 struct sd *sd; /* point to subdisk */
804 struct buf *ubp; /* user (high level) buffer header */
807 vol = &VOL[rqe->rqg->rq->volplex.volno];
808 sd = &SD[rqe->sdno]; /* point to subdisk */
810 ubio = rqe->rqg->rq->bio; /* pointer to user buffer header */
813 /* Initialize the buf struct */
814 /* copy these flags from user bp */
815 bp->b_flags = ubp->b_flags & (B_ORDERED | B_NOCACHE);
816 bp->b_cmd = ubp->b_cmd;
818 if (rqe->flags & XFR_BUFLOCKED) /* paranoia */
819 panic("build_rq_buffer: rqe already locked"); /* XXX remove this when we're sure */
821 BUF_LOCKINIT(bp); /* get a lock for the buffer */
822 BUF_LOCK(bp, LK_EXCLUSIVE); /* and lock it */
825 rqe->flags |= XFR_BUFLOCKED;
826 bp->b_bio1.bio_done = complete_rqe;
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.
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 */
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 */
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
854 bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE;
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
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 */
865 bzero(data, length); /* clean it out */
871 * Abort a request: free resources and complete the
872 * user request with the specified error
875 abortrequest(struct request *rq, int error)
877 struct buf *bp = rq->bio->bio_buf; /* user buffer */
880 freerq(rq); /* free everything we're doing */
881 bp->b_flags |= B_ERROR;
882 return error; /* and give up */
886 * Check that our transfer will cover the
887 * complete address space of the user request.
889 * Return 1 if it can, otherwise 0
892 check_range_covered(struct request *rq)
897 /* Perform I/O on a subdisk */
899 sdio(struct bio *bio)
904 vinum_off_t endoffset;
906 struct buf *bp = bio->bio_buf;
908 dev = bio->bio_driver_info;
911 if (debug & DEBUG_LASTREQS)
912 logrq(loginfo_sdio, (union rqinfou) bio, bio);
914 sd = &SD[Sdno(dev)]; /* point to the subdisk */
915 drive = &DRIVE[sd->driveno];
917 if (drive->state != drive_up) {
918 if (sd->state >= sd_crashed) {
919 if (bp->b_cmd != BUF_CMD_READ) /* writing, */
920 set_sd_state(sd->sdno, sd_stale, setstate_force);
922 set_sd_state(sd->sdno, sd_crashed, setstate_force);
925 bp->b_flags |= B_ERROR;
930 * We allow access to any kind of subdisk as long as we can expect
931 * to get the I/O performed.
933 if (sd->state < sd_empty) { /* nothing to talk to, */
935 bp->b_flags |= B_ERROR;
940 sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf));
942 bp->b_error = ENOMEM;
943 bp->b_flags |= B_ERROR;
947 bzero(sbp, sizeof(struct sdbuf)); /* start with nothing */
948 sbp->b.b_cmd = bp->b_cmd;
949 sbp->b.b_bcount = bp->b_bcount; /* number of bytes to transfer */
950 sbp->b.b_resid = bp->b_resid; /* and amount waiting */
951 sbp->b.b_data = bp->b_data; /* data buffer */
952 BUF_LOCKINIT(&sbp->b); /* get a lock for the buffer */
953 BUF_LOCK(&sbp->b, LK_EXCLUSIVE); /* and lock it */
954 BUF_KERNPROC(&sbp->b);
956 sbp->b.b_bio1.bio_offset = bio->bio_offset + ((off_t)sd->driveoffset << DEV_BSHIFT);
957 sbp->b.b_bio1.bio_done = sdio_done; /* come here on completion */
958 sbp->b.b_bio1.bio_flags |= BIO_SYNC;
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 = (vinum_off_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 */
969 BUF_LOCKFREE(&sbp->b);
975 if (debug & DEBUG_ADDRESSES)
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",
981 sbp->b.b_bio1.bio_offset - ((off_t)SD[sbp->sdno].driveoffset << DEV_BSHIFT),
982 sbp->b.b_bio1.bio_offset,
987 if (debug & DEBUG_LASTREQS)
988 logrq(loginfo_sdiol, (union rqinfou) &sbp->b.b_bio1, &sbp->b.b_bio1);
990 vn_strategy(drive->vp, &sbp->b.b_bio1);
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.
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".
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
1010 vinum_bounds_check(struct bio *bio, struct volume *vol)
1012 struct buf *bp = bio->bio_buf;
1014 vinum_off_t 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 vinum_off_t blkno = (vinum_off_t)(bio->bio_offset >> DEV_BSHIFT);
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;
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;
1035 bp->b_bcount = size << DEV_BSHIFT;
1037 nbio = push_bio(bio);
1038 nbio->bio_offset = bio->bio_offset;
1043 * Allocate a request group and hook
1044 * it in in the list for rq
1047 allocrqg(struct request *rq, int elements)
1049 struct rqgroup *rqg; /* the one we're going to allocate */
1050 int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement);
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 */
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 */
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.
1075 deallocrqg(struct rqgroup *rqg)
1077 struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */
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 */
1084 while ((rqgc->next != NULL) /* find the group */
1085 &&(rqgc->next != rqg))
1087 if (rqgc->next == NULL)
1089 "vinum deallocrqg: rqg %p not found in request %p\n",
1093 rqgc->next = rqg->next; /* make the chain jump over us */
1098 /* Local Variables: */
1099 /* fill-column: 50 */