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 1.15 2006/07/09 22:55:45 corecode Exp $
47 #include <sys/resourcevar.h>
49 enum requeststatus bre(struct request *rq,
53 enum requeststatus bre5(struct request *rq,
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(dev_t dev, struct bio *bio)
128 struct buf *bp = bio->bio_buf;
129 struct bio *nbio = bio;
130 struct volume *vol = NULL;
133 switch (DEVTYPE(dev)) {
135 case VINUM_RAWSD_TYPE:
136 bio->bio_driver_info = dev;
141 * In fact, vinum doesn't handle drives: they're
142 * handled directly by the disk drivers
144 case VINUM_DRIVE_TYPE:
146 bp->b_error = EIO; /* I/O error */
147 bp->b_flags |= B_ERROR;
151 case VINUM_VOLUME_TYPE: /* volume I/O */
154 if (vol->state != volume_up) { /* can't access this volume */
155 bp->b_error = EIO; /* I/O error */
156 bp->b_flags |= B_ERROR;
160 nbio = vinum_bounds_check(bio, vol);
167 * Plex I/O is pretty much the same as volume I/O
168 * for a single plex. Indicate this by passing a NULL
169 * pointer (set above) for the volume
171 case VINUM_PLEX_TYPE:
172 case VINUM_RAWPLEX_TYPE:
173 bp->b_resid = bp->b_bcount; /* transfer everything */
174 vinumstart(dev, nbio, 0);
180 * Start a transfer. Return -1 on error,
181 * 0 if OK, 1 if we need to retry.
182 * Parameter reviveok is set when doing
183 * transfers for revives: it allows transfers to
184 * be started immediately when a revive is in
185 * progress. During revive, normal transfers
186 * are queued if they share address space with
187 * a currently active revive operation.
190 vinumstart(dev_t dev, struct bio *bio, int reviveok)
192 struct buf *bp = bio->bio_buf;
194 int maxplex; /* maximum number of plexes to handle */
196 struct request *rq; /* build up our request here */
197 enum requeststatus status;
199 bio->bio_driver_info = dev;
202 if (debug & DEBUG_LASTREQS)
203 logrq(loginfo_user_bp, (union rqinfou) bio, bio);
206 if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */
207 bp->b_error = EINVAL; /* invalid size */
208 bp->b_flags |= B_ERROR;
212 rq = (struct request *) Malloc(sizeof(struct request)); /* allocate a request struct */
213 if (rq == NULL) { /* can't do it */
214 bp->b_error = ENOMEM; /* can't get memory */
215 bp->b_flags |= B_ERROR;
219 bzero(rq, sizeof(struct request));
222 * Note the volume ID. This can be NULL, which
223 * the request building functions use as an
224 * indication for single plex I/O
226 rq->bio = bio; /* and the user buffer struct */
228 if (DEVTYPE(dev) == VINUM_VOLUME_TYPE) { /* it's a volume, */
229 rq->volplex.volno = Volno(dev); /* get the volume number */
230 vol = &VOL[rq->volplex.volno]; /* and point to it */
231 vol->active++; /* one more active request */
232 maxplex = vol->plexes; /* consider all its plexes */
234 vol = NULL; /* no volume */
235 rq->volplex.plexno = Plexno(dev); /* point to the plex */
236 rq->isplex = 1; /* note that it's a plex */
237 maxplex = 1; /* just the one plex */
240 if (bp->b_cmd == BUF_CMD_READ) {
242 * This is a read request. Decide
243 * which plex to read from.
245 * There's a potential race condition here,
246 * since we're not locked, and we could end
247 * up multiply incrementing the round-robin
248 * counter. This doesn't have any serious
252 plexno = vol->preferred_plex; /* get the plex to use */
253 if (plexno < 0) { /* round robin */
254 plexno = vol->last_plex_read;
255 vol->last_plex_read++;
256 if (vol->last_plex_read >= vol->plexes) /* got the the end? */
257 vol->last_plex_read = 0; /* wrap around */
259 status = build_read_request(rq, plexno); /* build a request */
261 daddr_t diskaddr = (daddr_t)(bio->bio_offset >> DEV_BSHIFT);
262 /* start offset of transfer */
263 status = bre(rq, /* build a request list */
266 diskaddr + (bp->b_bcount / DEV_BSIZE));
269 if (status > REQUEST_RECOVERED) { /* can't satisfy it */
270 if (status == REQUEST_DOWN) { /* not enough subdisks */
271 bp->b_error = EIO; /* I/O error */
272 bp->b_flags |= B_ERROR;
278 return launch_requests(rq, reviveok); /* now start the requests if we can */
281 * This is a write operation. We write to all plexes. If this is
282 * a RAID-4 or RAID-5 plex, we must also update the parity stripe.
286 status = build_write_request(rq); /* Not all the subdisks are up */
287 else { /* plex I/O */
291 diskstart = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */
292 diskend = diskstart + bp->b_bcount / DEV_BSIZE;
293 status = bre(rq, Plexno(dev),
294 &diskstart, diskend); /* build requests for the plex */
296 if (status > REQUEST_RECOVERED) { /* can't satisfy it */
297 if (status == REQUEST_DOWN) { /* not enough subdisks */
298 bp->b_error = EIO; /* I/O error */
299 bp->b_flags |= B_ERROR;
305 return launch_requests(rq, reviveok); /* now start the requests if we can */
310 * Call the low-level strategy routines to
311 * perform the requests in a struct request
314 launch_requests(struct request *rq, int reviveok)
317 int rqno; /* loop index */
318 struct rqelement *rqe; /* current element */
320 int rcount; /* request count */
323 * First find out whether we're reviving, and the
324 * request contains a conflict. If so, we hang
325 * the request off plex->waitlist of the first
326 * plex we find which is reviving
329 if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */
330 &&(!reviveok)) { /* and we don't want to do it now, */
332 struct request *waitlist; /* point to the waitlist */
335 if (sd->waitlist != NULL) { /* something there already, */
336 waitlist = sd->waitlist;
337 while (waitlist->next != NULL) /* find the end */
338 waitlist = waitlist->next;
339 waitlist->next = rq; /* hook our request there */
341 sd->waitlist = rq; /* hook our request at the front */
344 if (debug & DEBUG_REVIVECONFLICT) {
346 "Revive conflict sd %d: %p\n%s dev %d.%d, offset 0x%llx, length %d\n",
349 (rq->bio->bio_buf->b_cmd & BUF_CMD_READ) ? "Read" : "Write",
350 major(((dev_t)rq->bio->bio_driver_info)),
351 minor(((dev_t)rq->bio->bio_driver_info)),
353 rq->bio->bio_buf->b_bcount);
356 return 0; /* and get out of here */
358 rq->active = 0; /* nothing yet */
360 if (debug & DEBUG_ADDRESSES)
362 "Request: %p\n%s dev %d.%d, offset 0x%llx, length %d\n",
364 (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) ? "Read" : "Write",
365 major(((dev_t)rq->bio->bio_driver_info)),
366 minor(((dev_t)rq->bio->bio_driver_info)),
368 rq->bio->bio_buf->b_bcount);
369 vinum_conf.lastrq = rq;
370 vinum_conf.lastbio = rq->bio;
371 if (debug & DEBUG_LASTREQS)
372 logrq(loginfo_user_bpl, (union rqinfou) rq->bio, rq->bio);
376 * This loop happens without any participation
377 * of the bottom half, so it requires no
380 for (rqg = rq->rqg; rqg != NULL; rqg = rqg->next) { /* through the whole request chain */
381 rqg->active = rqg->count; /* they're all active */
382 for (rqno = 0; rqno < rqg->count; rqno++) {
383 rqe = &rqg->rqe[rqno];
384 if (rqe->flags & XFR_BAD_SUBDISK) /* this subdisk is bad, */
385 rqg->active--; /* one less active request */
387 if (rqg->active) /* we have at least one active request, */
388 rq->active++; /* one more active request group */
392 * Now fire off the requests. In this loop the
393 * bottom half could be completing requests
394 * before we finish, so we need critical section protection.
397 for (rqg = rq->rqg; rqg != NULL;) { /* through the whole request chain */
398 if (rqg->lockbase >= 0) /* this rqg needs a lock first */
399 rqg->lock = lockrange(rqg->lockbase, rqg->rq->bio->bio_buf, &PLEX[rqg->plexno]);
401 for (rqno = 0; rqno < rcount;) {
404 rqe = &rqg->rqe[rqno];
407 * Point to next rqg before the bottom end
408 * changes the structures.
410 if (++rqno >= rcount)
412 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) { /* this subdisk is good, */
413 drive = &DRIVE[rqe->driveno]; /* look at drive */
415 if (drive->active >= drive->maxactive)
416 drive->maxactive = drive->active;
418 if (vinum_conf.active >= vinum_conf.maxactive)
419 vinum_conf.maxactive = vinum_conf.active;
421 dev = rqe->b.b_bio1.bio_driver_info;
423 if (debug & DEBUG_ADDRESSES)
425 " %s dev %d.%d, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n",
426 (rqe->b.b_cmd == BUF_CMD_READ) ? "Read" : "Write",
430 rqe->b.b_bio1.bio_offset - ((off_t)SD[rqe->sdno].driveoffset << DEV_BSHIFT),
431 rqe->b.b_bio1.bio_offset,
433 if (debug & DEBUG_LASTREQS)
434 logrq(loginfo_rqe, (union rqinfou) rqe, rq->bio);
436 /* fire off the request */
437 dev_dstrategy(dev, &rqe->b.b_bio1);
446 * define the low-level requests needed to perform a
447 * high-level I/O operation for a specific plex 'plexno'.
449 * Return REQUEST_OK if all subdisks involved in the request are up,
450 * REQUEST_DOWN if some subdisks are not up, and REQUEST_EOF if the
451 * request is at least partially outside the bounds of the subdisks.
453 * Modify the pointer *diskstart to point to the end address. On
454 * read, return on the first bad subdisk, so that the caller
455 * (build_read_request) can try alternatives.
457 * On entry to this routine, the rqg structures are not assigned. The
458 * assignment is performed by expandrq(). Strictly speaking, the
459 * elements rqe->sdno of all entries should be set to -1, since 0
460 * (from bzero) is a valid subdisk number. We avoid this problem by
461 * initializing the ones we use, and not looking at the others (index
465 bre(struct request *rq,
474 struct buf *bp; /* user's bp */
476 enum requeststatus status; /* return value */
477 daddr_t plexoffset; /* offset of transfer in plex */
478 daddr_t stripebase; /* base address of stripe (1st subdisk) */
479 daddr_t stripeoffset; /* offset in stripe */
480 daddr_t blockoffset; /* offset in stripe on subdisk */
481 struct rqelement *rqe; /* point to this request information */
482 daddr_t diskstart = *diskaddr; /* remember where this transfer starts */
483 enum requeststatus s; /* temp return value */
485 bio = rq->bio; /* buffer pointer */
487 status = REQUEST_OK; /* return value: OK until proven otherwise */
488 plex = &PLEX[plexno]; /* point to the plex */
490 switch (plex->organization) {
492 sd = NULL; /* (keep compiler quiet) */
493 for (sdno = 0; sdno < plex->subdisks; sdno++) {
494 sd = &SD[plex->sdnos[sdno]];
495 if (*diskaddr < sd->plexoffset) /* we must have a hole, */
496 status = REQUEST_DEGRADED; /* note the fact */
497 if (*diskaddr < (sd->plexoffset + sd->sectors)) { /* the request starts in this subdisk */
498 rqg = allocrqg(rq, 1); /* space for the request */
499 if (rqg == NULL) { /* malloc failed */
500 bp->b_error = ENOMEM;
501 bp->b_flags |= B_ERROR;
502 return REQUEST_ENOMEM;
504 rqg->plexno = plexno;
506 rqe = &rqg->rqe[0]; /* point to the element */
507 rqe->rqg = rqg; /* group */
508 rqe->sdno = sd->sdno; /* put in the subdisk number */
509 plexoffset = *diskaddr; /* start offset in plex */
510 rqe->sdoffset = plexoffset - sd->plexoffset; /* start offset in subdisk */
511 rqe->useroffset = plexoffset - diskstart; /* start offset in user buffer */
513 rqe->datalen = min(diskend - *diskaddr, /* number of sectors to transfer in this sd */
514 sd->sectors - rqe->sdoffset);
515 rqe->groupoffset = 0; /* no groups for concatenated plexes */
517 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */
519 rqe->driveno = sd->driveno;
520 if (sd->state != sd_up) { /* *now* we find the sd is down */
521 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */
522 if (s == REQUEST_DOWN) { /* down? */
523 rqe->flags = XFR_BAD_SUBDISK; /* yup */
524 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */
525 return REQUEST_DEGRADED; /* give up here */
527 * If we're writing, don't give up
528 * because of a bad subdisk. Go
529 * through to the bitter end, but note
530 * which ones we can't access.
532 status = REQUEST_DEGRADED; /* can't do it all */
535 *diskaddr += rqe->datalen; /* bump the address */
536 if (build_rq_buffer(rqe, plex)) { /* build the buffer */
538 bp->b_error = ENOMEM;
539 bp->b_flags |= B_ERROR;
540 return REQUEST_ENOMEM; /* can't do it */
543 if (*diskaddr == diskend) /* we're finished, */
544 break; /* get out of here */
547 * We've got to the end of the plex. Have we got to the end of
548 * the transfer? It would seem that having an offset beyond the
549 * end of the subdisk is an error, but in fact it can happen if
550 * the volume has another plex of different size. There's a valid
551 * question as to why you would want to do this, but currently
554 * In a previous version, I returned REQUEST_DOWN here. I think
555 * REQUEST_EOF is more appropriate now.
557 if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */
558 status = REQUEST_EOF;
563 while (*diskaddr < diskend) { /* until we get it all sorted out */
564 if (*diskaddr >= plex->length) /* beyond the end of the plex */
565 return REQUEST_EOF; /* can't continue */
567 /* The offset of the start address from the start of the stripe. */
568 stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks);
570 /* The plex-relative address of the start of the stripe. */
571 stripebase = *diskaddr - stripeoffset;
573 /* The number of the subdisk in which the start is located. */
574 sdno = stripeoffset / plex->stripesize;
576 /* The offset from the beginning of the stripe on this subdisk. */
577 blockoffset = stripeoffset % plex->stripesize;
579 sd = &SD[plex->sdnos[sdno]]; /* the subdisk in question */
580 rqg = allocrqg(rq, 1); /* space for the request */
581 if (rqg == NULL) { /* malloc failed */
582 bp->b_error = ENOMEM;
583 bp->b_flags |= B_ERROR;
584 return REQUEST_ENOMEM;
586 rqg->plexno = plexno;
588 rqe = &rqg->rqe[0]; /* point to the element */
590 rqe->sdoffset = stripebase / plex->subdisks + blockoffset; /* start offset in this subdisk */
591 rqe->useroffset = *diskaddr - diskstart; /* The offset of the start in the user buffer */
593 rqe->datalen = min(diskend - *diskaddr, /* the amount remaining to transfer */
594 plex->stripesize - blockoffset); /* and the amount left in this stripe */
595 rqe->groupoffset = 0; /* no groups for striped plexes */
597 rqe->buflen = rqe->datalen; /* buffer length is data buffer length */
599 rqe->sdno = sd->sdno; /* put in the subdisk number */
600 rqe->driveno = sd->driveno;
602 if (sd->state != sd_up) { /* *now* we find the sd is down */
603 s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */
604 if (s == REQUEST_DOWN) { /* down? */
605 rqe->flags = XFR_BAD_SUBDISK; /* yup */
606 if (rq->bio->bio_buf->b_cmd == BUF_CMD_READ) /* read request, */
607 return REQUEST_DEGRADED; /* give up here */
609 * If we're writing, don't give up
610 * because of a bad subdisk. Go through
611 * to the bitter end, but note which
612 * ones we can't access.
614 status = REQUEST_DEGRADED; /* can't do it all */
618 * It would seem that having an offset
619 * beyond the end of the subdisk is an
620 * error, but in fact it can happen if the
621 * volume has another plex of different
622 * size. There's a valid question as to why
623 * you would want to do this, but currently
626 if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */
627 rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */
629 if (debug & DEBUG_EOFINFO) { /* tell on the request */
631 "vinum: EOF on plex %s, sd %s offset %llx (user offset %x)\n",
635 bp->b_bio1.bio_offset);
637 "vinum: stripebase %x, stripeoffset %x, blockoffset %x\n",
644 if (build_rq_buffer(rqe, plex)) { /* build the buffer */
646 bp->b_error = ENOMEM;
647 bp->b_flags |= B_ERROR;
648 return REQUEST_ENOMEM; /* can't do it */
650 *diskaddr += rqe->datalen; /* look at the remainder */
651 if ((*diskaddr < diskend) /* didn't finish the request on this stripe */
652 &&(*diskaddr < plex->length)) { /* and there's more to come */
653 plex->multiblock++; /* count another one */
654 if (sdno == plex->subdisks - 1) /* last subdisk, */
655 plex->multistripe++; /* another stripe as well */
662 * RAID-4 and RAID-5 are complicated enough to have their own
667 status = bre5(rq, plexno, diskaddr, diskend);
671 log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization);
672 status = REQUEST_DOWN; /* can't access it */
679 * Build up a request structure for reading volumes.
680 * This function is not needed for plex reads, since there's
681 * no recovery if a plex read can't be satisified.
684 build_read_request(struct request *rq, /* request */
686 { /* index in the volume's plex table */
689 daddr_t startaddr; /* offset of previous part of transfer */
690 daddr_t diskaddr; /* offset of current part of transfer */
691 daddr_t diskend; /* and end offset of transfer */
692 int plexno; /* plex index in vinum_conf */
693 struct rqgroup *rqg; /* point to the request we're working on */
694 struct volume *vol; /* volume in question */
695 int recovered = 0; /* set if we recover a read */
696 enum requeststatus status = REQUEST_OK;
697 int plexmask; /* bit mask of plexes, for recovery */
699 bio = rq->bio; /* buffer pointer */
701 diskaddr = bio->bio_offset >> DEV_BSHIFT; /* start offset of transfer */
702 diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */
703 rqg = &rq->rqg[plexindex]; /* plex request */
704 vol = &VOL[rq->volplex.volno]; /* point to volume */
706 while (diskaddr < diskend) { /* build up request components */
707 startaddr = diskaddr;
708 status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */
713 case REQUEST_RECOVERED:
715 * XXX FIXME if we have more than one plex, and we can
716 * satisfy the request from another, don't use the
717 * recovered request, since it's more expensive.
725 * If we get here, our request is not complete. Try
726 * to fill in the missing parts from another plex.
727 * This can happen multiple times in this function,
728 * and we reinitialize the plex mask each time, since
729 * we could have a hole in our plexes.
732 case REQUEST_DOWN: /* can't access the plex */
733 case REQUEST_DEGRADED: /* can't access the plex */
734 plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */
735 &~(1 << plexindex); /* except for the one we were looking at */
736 for (plexno = 0; plexno < vol->plexes; plexno++) {
737 if (plexmask == 0) /* no plexes left to try */
738 return REQUEST_DOWN; /* failed */
739 diskaddr = startaddr; /* start at the beginning again */
740 if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */
741 bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */
742 if (diskaddr > startaddr) { /* we satisfied another part */
743 recovered = 1; /* we recovered from the problem */
744 status = REQUEST_OK; /* don't complain about it */
749 if (diskaddr == startaddr) /* didn't get any further, */
753 vol->recovered_reads += recovered; /* adjust our recovery count */
759 * Build up a request structure for writes.
760 * Return 0 if all subdisks involved in the request are up, 1 if some
761 * subdisks are not up, and -1 if the request is at least partially
762 * outside the bounds of the subdisks.
765 build_write_request(struct request *rq)
769 daddr_t diskstart; /* offset of current part of transfer */
770 daddr_t diskend; /* and end offset of transfer */
771 int plexno; /* plex index in vinum_conf */
772 struct volume *vol; /* volume in question */
773 enum requeststatus status;
775 bio = rq->bio; /* buffer pointer */
777 vol = &VOL[rq->volplex.volno]; /* point to volume */
778 diskend = (daddr_t)(bio->bio_offset >> DEV_BSHIFT) + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */
779 status = REQUEST_DOWN; /* assume the worst */
780 for (plexno = 0; plexno < vol->plexes; plexno++) {
781 diskstart = (daddr_t)(bio->bio_offset >> DEV_BSHIFT); /* start offset of transfer */
783 * Build requests for the plex.
784 * We take the best possible result here (min,
785 * not max): we're happy if we can write at all
787 status = min(status, bre(rq,
795 /* Fill in the struct buf part of a request element. */
797 build_rq_buffer(struct rqelement *rqe, struct plex *plex)
799 struct sd *sd; /* point to subdisk */
802 struct buf *ubp; /* user (high level) buffer header */
805 vol = &VOL[rqe->rqg->rq->volplex.volno];
806 sd = &SD[rqe->sdno]; /* point to subdisk */
808 ubio = rqe->rqg->rq->bio; /* pointer to user buffer header */
811 /* Initialize the buf struct */
812 /* copy these flags from user bp */
813 bp->b_flags = ubp->b_flags & (B_ORDERED | B_NOCACHE | B_ASYNC);
814 bp->b_cmd = ubp->b_cmd;
816 if (rqe->flags & XFR_BUFLOCKED) /* paranoia */
817 panic("build_rq_buffer: rqe already locked"); /* XXX remove this when we're sure */
819 BUF_LOCKINIT(bp); /* get a lock for the buffer */
820 BUF_LOCK(bp, LK_EXCLUSIVE); /* and lock it */
823 rqe->flags |= XFR_BUFLOCKED;
824 bp->b_bio1.bio_done = complete_rqe;
826 * You'd think that we wouldn't need to even
827 * build the request buffer for a dead subdisk,
828 * but in some cases we need information like
829 * the user buffer address. Err on the side of
830 * generosity and supply what we can. That
831 * obviously doesn't include drive information
832 * when the drive is dead.
834 if ((rqe->flags & XFR_BAD_SUBDISK) == 0) /* subdisk is accessible, */
835 bp->b_bio1.bio_driver_info = DRIVE[rqe->driveno].dev; /* drive device */
836 bp->b_bio1.bio_offset = (off_t)(rqe->sdoffset + sd->driveoffset) << DEV_BSHIFT; /* start address */
837 bp->b_bcount = rqe->buflen << DEV_BSHIFT; /* number of bytes to transfer */
838 bp->b_resid = bp->b_bcount; /* and it's still all waiting */
840 if (rqe->flags & XFR_MALLOCED) { /* this operation requires a malloced buffer */
841 bp->b_data = Malloc(bp->b_bcount); /* get a buffer to put it in */
842 if (bp->b_data == NULL) { /* failed */
843 abortrequest(rqe->rqg->rq, ENOMEM);
844 return REQUEST_ENOMEM; /* no memory */
848 * Point directly to user buffer data. This means
849 * that we don't need to do anything when we have
850 * finished the transfer
852 bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE;
854 * On a recovery read, we perform an XOR of
855 * all blocks to the user buffer. To make
856 * this work, we first clean out the buffer
858 if ((rqe->flags & (XFR_RECOVERY_READ | XFR_BAD_SUBDISK))
859 == (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) { /* bad subdisk of a recovery read */
860 int length = rqe->grouplen << DEV_BSHIFT; /* and count involved */
861 char *data = (char *) &rqe->b.b_data[rqe->groupoffset << DEV_BSHIFT]; /* destination */
863 bzero(data, length); /* clean it out */
869 * Abort a request: free resources and complete the
870 * user request with the specified error
873 abortrequest(struct request *rq, int error)
875 struct buf *bp = rq->bio->bio_buf; /* user buffer */
878 freerq(rq); /* free everything we're doing */
879 bp->b_flags |= B_ERROR;
880 return error; /* and give up */
884 * Check that our transfer will cover the
885 * complete address space of the user request.
887 * Return 1 if it can, otherwise 0
890 check_range_covered(struct request *rq)
895 /* Perform I/O on a subdisk */
897 sdio(struct bio *bio)
905 struct buf *bp = bio->bio_buf;
907 dev = bio->bio_driver_info;
910 if (debug & DEBUG_LASTREQS)
911 logrq(loginfo_sdio, (union rqinfou) bio, bio);
913 sd = &SD[Sdno(dev)]; /* point to the subdisk */
914 drive = &DRIVE[sd->driveno];
916 if (drive->state != drive_up) {
917 if (sd->state >= sd_crashed) {
918 if (bp->b_cmd != BUF_CMD_READ) /* writing, */
919 set_sd_state(sd->sdno, sd_stale, setstate_force);
921 set_sd_state(sd->sdno, sd_crashed, setstate_force);
924 bp->b_flags |= B_ERROR;
929 * We allow access to any kind of subdisk as long as we can expect
930 * to get the I/O performed.
932 if (sd->state < sd_empty) { /* nothing to talk to, */
934 bp->b_flags |= B_ERROR;
939 sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf));
941 bp->b_error = ENOMEM;
942 bp->b_flags |= B_ERROR;
946 sddev = DRIVE[sd->driveno].dev; /* device */
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->bio = bio; /* note the address of the original header */
959 sbp->sdno = sd->sdno; /* note for statistics */
960 sbp->driveno = sd->driveno;
961 endoffset = (daddr_t)(bio->bio_offset >> DEV_BSHIFT) + sbp->b.b_bcount / DEV_BSIZE; /* final sector offset */
962 if (endoffset > sd->sectors) { /* beyond the end */
963 sbp->b.b_bcount -= (endoffset - sd->sectors) * DEV_BSIZE; /* trim */
964 if (sbp->b.b_bcount <= 0) { /* nothing to transfer */
965 bp->b_resid = bp->b_bcount; /* nothing transferred */
968 BUF_LOCKFREE(&sbp->b);
974 if (debug & DEBUG_ADDRESSES)
976 " %s dev %d.%d, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n",
977 (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 dev_dstrategy(sddev, &sbp->b.b_bio1);
995 * Simplified version of bounds_check_with_label
996 * Determine the size of the transfer, and make sure it is
997 * within the boundaries of the partition. Adjust transfer
998 * if needed, and signal errors or early completion.
1000 * Volumes are simpler than disk slices: they only contain
1001 * one component (though we call them a, b and c to make
1002 * system utilities happy), and they always take up the
1003 * complete space of the "partition".
1005 * I'm still not happy with this: why should the label be
1006 * protected? If it weren't so damned difficult to write
1007 * one in the first pleace (because it's protected), it wouldn't
1011 vinum_bounds_check(struct bio *bio, struct volume *vol)
1013 struct buf *bp = bio->bio_buf;
1015 int maxsize = vol->size; /* size of the partition (sectors) */
1016 int size = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* size of this request (sectors) */
1017 daddr_t blkno = (daddr_t)(bio->bio_offset >> DEV_BSHIFT);
1019 /* Would this transfer overwrite the disk label? */
1020 if (blkno <= LABELSECTOR /* starts before or at the label */
1021 #if LABELSECTOR != 0
1022 && blkno + size > LABELSECTOR /* and finishes after */
1024 && (!(vol->flags & VF_RAW)) /* and it's not raw */
1025 && (bp->b_cmd != BUF_CMD_READ) /* and it's a write */
1026 &&(!vol->flags & (VF_WLABEL | VF_LABELLING))) { /* and we're not allowed to write the label */
1027 bp->b_error = EROFS; /* read-only */
1028 bp->b_flags |= B_ERROR;
1031 if (size == 0) /* no transfer specified, */
1032 return 0; /* treat as EOF */
1033 /* beyond partition? */
1034 if (bio->bio_offset < 0 /* negative start */
1035 || blkno + size > maxsize) { /* or goes beyond the end of the partition */
1036 /* if exactly at end of disk, return an EOF */
1037 if (blkno == maxsize) {
1038 bp->b_resid = bp->b_bcount;
1041 /* or truncate if part of it fits */
1042 size = maxsize - blkno;
1043 if (size <= 0) { /* nothing to transfer */
1044 bp->b_error = EINVAL;
1045 bp->b_flags |= B_ERROR;
1048 bp->b_bcount = size << DEV_BSHIFT;
1050 nbio = push_bio(bio);
1051 nbio->bio_offset = bio->bio_offset;
1056 * Allocate a request group and hook
1057 * it in in the list for rq
1060 allocrqg(struct request *rq, int elements)
1062 struct rqgroup *rqg; /* the one we're going to allocate */
1063 int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement);
1065 rqg = (struct rqgroup *) Malloc(size);
1066 if (rqg != NULL) { /* malloc OK, */
1067 if (rq->rqg) /* we already have requests */
1068 rq->lrqg->next = rqg; /* hang it off the end */
1069 else /* first request */
1070 rq->rqg = rqg; /* at the start */
1071 rq->lrqg = rqg; /* this one is the last in the list */
1073 bzero(rqg, size); /* no old junk */
1074 rqg->rq = rq; /* point back to the parent request */
1075 rqg->count = elements; /* number of requests in the group */
1076 rqg->lockbase = -1; /* no lock required yet */
1082 * Deallocate a request group out of a chain. We do
1083 * this by linear search: the chain is short, this
1084 * almost never happens, and currently it can only
1085 * happen to the first member of the chain.
1088 deallocrqg(struct rqgroup *rqg)
1090 struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */
1092 if (rqg->lock) /* got a lock? */
1093 unlockrange(rqg->plexno, rqg->lock); /* yes, free it */
1094 if (rqgc == rqg) /* we're first in line */
1095 rqg->rq->rqg = rqg->next; /* unhook ourselves */
1097 while ((rqgc->next != NULL) /* find the group */
1098 &&(rqgc->next != rqg))
1100 if (rqgc->next == NULL)
1102 "vinum deallocrqg: rqg %p not found in request %p\n",
1106 rqgc->next = rqg->next; /* make the chain jump over us */
1111 /* Local Variables: */
1112 /* fill-column: 50 */