/*- * Copyright (c) 1997, 1998, 1999 * Nan Yang Computer Services Limited. All rights reserved. * * Parts copyright (c) 1997, 1998 Cybernet Corporation, NetMAX project. * * Written by Greg Lehey * * This software is distributed under the so-called ``Berkeley * License'': * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Nan Yang Computer * Services Limited. * 4. Neither the name of the Company nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * This software is provided ``as is'', and any express or implied * warranties, including, but not limited to, the implied warranties of * merchantability and fitness for a particular purpose are disclaimed. * In no event shall the company or contributors be liable for any * direct, indirect, incidental, special, exemplary, or consequential * damages (including, but not limited to, procurement of substitute * goods or services; loss of use, data, or profits; or business * interruption) however caused and on any theory of liability, whether * in contract, strict liability, or tort (including negligence or * otherwise) arising in any way out of the use of this software, even if * advised of the possibility of such damage. * * $Id: vinumrequest.c,v 1.2 2004/11/08 21:30:05 explorer Exp $ * $FreeBSD$ */ #include #include #include enum requeststatus bre(struct request *rq, int plexno, daddr_t * diskstart, daddr_t diskend); enum requeststatus bre5(struct request *rq, int plexno, daddr_t * diskstart, daddr_t diskend); enum requeststatus build_read_request(struct request *rq, int volplexno); enum requeststatus build_write_request(struct request *rq); enum requeststatus build_rq_buffer(struct rqelement *rqe, struct plex *plex); int find_alternate_sd(struct request *rq); int check_range_covered(struct request *); void complete_rqe(struct buf *bp); void complete_raid5_write(struct rqelement *); int abortrequest(struct request *rq, int error); void sdio_done(struct buf *bp); int vinum_bounds_check(struct buf *bp, struct volume *vol); caddr_t allocdatabuf(struct rqelement *rqe); void freedatabuf(struct rqelement *rqe); #ifdef VINUMDEBUG struct rqinfo rqinfo[RQINFO_SIZE]; struct rqinfo *rqip = rqinfo; void logrq(enum rqinfo_type type, union rqinfou info, struct buf *ubp) { int s = splhigh(); microtime(&rqip->timestamp); /* when did this happen? */ rqip->type = type; rqip->bp = ubp; /* user buffer */ switch (type) { case loginfo_user_bp: case loginfo_user_bpl: case loginfo_sdio: /* subdisk I/O */ case loginfo_sdiol: /* subdisk I/O launch */ case loginfo_sdiodone: /* subdisk I/O complete */ bcopy(info.bp, &rqip->info.b, sizeof(struct buf)); rqip->devmajor = major(info.bp->b_dev); rqip->devminor = minor(info.bp->b_dev); break; case loginfo_iodone: case loginfo_rqe: case loginfo_raid5_data: case loginfo_raid5_parity: bcopy(info.rqe, &rqip->info.rqe, sizeof(struct rqelement)); rqip->devmajor = major(info.rqe->b.b_dev); rqip->devminor = minor(info.rqe->b.b_dev); break; case loginfo_lockwait: case loginfo_lock: case loginfo_unlock: bcopy(info.lockinfo, &rqip->info.lockinfo, sizeof(struct rangelock)); break; case loginfo_unused: break; } rqip++; if (rqip >= &rqinfo[RQINFO_SIZE]) /* wrap around */ rqip = rqinfo; splx(s); } #endif void vinumstrategy(struct buf *bp) { int volno; struct volume *vol = NULL; switch (DEVTYPE(bp->b_dev)) { case VINUM_SD_TYPE: case VINUM_SD2_TYPE: sdio(bp); return; default: bp->b_error = EIO; /* I/O error */ bp->b_flags |= B_ERROR; biodone(bp); return; case VINUM_VOLUME_TYPE: /* volume I/O */ volno = Volno(bp->b_dev); vol = &VOL[volno]; if (vol->state != volume_up) { /* can't access this volume */ bp->b_error = EIO; /* I/O error */ bp->b_flags |= B_ERROR; biodone(bp); return; } if (vinum_bounds_check(bp, vol) <= 0) { /* don't like them bounds */ biodone(bp); return; } /* FALLTHROUGH */ /* * Plex I/O is pretty much the same as volume I/O * for a single plex. Indicate this by passing a NULL * pointer (set above) for the volume */ case VINUM_PLEX_TYPE: bp->b_resid = bp->b_bcount; /* transfer everything */ vinumstart(bp, 0); return; } } /* * Start a transfer. Return -1 on error, 0 if OK, * 1 if we need to retry. Parameter reviveok is * set when doing transfers for revives: it allows * transfers to be started immediately when a * revive is in progress. During revive, normal * transfers are queued if they share address * space with a currently active revive operation. */ int vinumstart(struct buf *bp, int reviveok) { int plexno; int maxplex; /* maximum number of plexes to handle */ struct volume *vol; struct request *rq; /* build up our request here */ enum requeststatus status; #ifdef VINUMDEBUG if (debug & DEBUG_LASTREQS) logrq(loginfo_user_bp, (union rqinfou) bp, bp); #endif if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */ bp->b_error = EINVAL; /* invalid size */ bp->b_flags |= B_ERROR; biodone(bp); return -1; } rq = (struct request *) Malloc(sizeof(struct request)); /* allocate a request struct */ if (rq == NULL) { /* can't do it */ bp->b_error = ENOMEM; /* can't get memory */ bp->b_flags |= B_ERROR; biodone(bp); return -1; } bzero(rq, sizeof(struct request)); /* * Note the volume ID. This can be NULL, which * the request building functions use as an * indication for single plex I/O. */ rq->bp = bp; /* and the user buffer struct */ if (DEVTYPE(bp->b_dev) == VINUM_VOLUME_TYPE) { /* it's a volume, */ rq->volplex.volno = Volno(bp->b_dev); /* get the volume number */ vol = &VOL[rq->volplex.volno]; /* and point to it */ vol->active++; /* one more active request */ maxplex = vol->plexes; /* consider all its plexes */ } else { vol = NULL; /* no volume */ rq->volplex.plexno = Plexno(bp->b_dev); /* point to the plex */ rq->isplex = 1; /* note that it's a plex */ maxplex = 1; /* just the one plex */ } if (bp->b_flags & B_READ) { /* * This is a read request. Decide * which plex to read from. * * There's a potential race condition here, * since we're not locked, and we could end * up multiply incrementing the round-robin * counter. This doesn't have any serious * effects, however. */ if (vol != NULL) { plexno = vol->preferred_plex; /* get the plex to use */ if (plexno < 0) { /* round robin */ plexno = vol->last_plex_read; vol->last_plex_read++; if (vol->last_plex_read >= vol->plexes) /* got the the end? */ vol->last_plex_read = 0; /* wrap around */ } status = build_read_request(rq, plexno); /* build a request */ } else { daddr_t diskaddr = bp->b_blkno; /* start offset of transfer */ status = bre(rq, /* build a request list */ rq->volplex.plexno, &diskaddr, diskaddr + (bp->b_bcount / DEV_BSIZE)); } if (status > REQUEST_RECOVERED) { /* can't satisfy it */ if (status == REQUEST_DOWN) { /* not enough subdisks */ bp->b_error = EIO; /* I/O error */ bp->b_flags |= B_ERROR; } biodone(bp); freerq(rq); return -1; } return launch_requests(rq, reviveok); /* now start the requests if we can */ } else /* * This is a write operation. We write to all plexes. If this is * a RAID-4 or RAID-5 plex, we must also update the parity stripe. */ { if (vol != NULL) { if ((vol->plexes > 0) /* multiple plex */ ||(isparity((&PLEX[vol->plex[0]])))) { /* or RAID-[45], */ rq->save_data = bp->b_data; /* save the data buffer address */ bp->b_data = Malloc(bp->b_bcount); bcopy(rq->save_data, bp->b_data, bp->b_bcount); /* make a copy */ rq->flags |= XFR_COPYBUF; /* and note that we did it */ } status = build_write_request(rq); } else { /* plex I/O */ daddr_t diskstart; diskstart = bp->b_blkno; /* start offset of transfer */ status = bre(rq, Plexno(bp->b_dev), &diskstart, bp->b_blkno + (bp->b_bcount / DEV_BSIZE)); /* build requests for the plex */ } if (status > REQUEST_RECOVERED) { /* can't satisfy it */ if (status == REQUEST_DOWN) { /* not enough subdisks */ bp->b_error = EIO; /* I/O error */ bp->b_flags |= B_ERROR; } if (rq->flags & XFR_COPYBUF) { Free(bp->b_data); bp->b_data = rq->save_data; } biodone(bp); freerq(rq); return -1; } return launch_requests(rq, reviveok); /* now start the requests if we can */ } } /* * Call the low-level strategy routines to * perform the requests in a struct request */ int launch_requests(struct request *rq, int reviveok) { struct rqgroup *rqg; int rqno; /* loop index */ struct rqelement *rqe; /* current element */ struct drive *drive; int rcount; /* request count */ const struct bdevsw *bdev; /* * First find out whether we're reviving, and * the request contains a conflict. If so, we * hang the request off plex->waitlist of the * first plex we find which is reviving. */ if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */ &&(!reviveok)) { /* and we don't want to do it now, */ struct sd *sd; struct request *waitlist; /* point to the waitlist */ sd = &SD[rq->sdno]; if (sd->waitlist != NULL) { /* something there already, */ waitlist = sd->waitlist; while (waitlist->next != NULL) /* find the end */ waitlist = waitlist->next; waitlist->next = rq; /* hook our request there */ } else sd->waitlist = rq; /* hook our request at the front */ #ifdef VINUMDEBUG if (debug & DEBUG_REVIVECONFLICT) log(LOG_DEBUG, "Revive conflict sd %d: %p\n%s dev %d.%d, offset 0x%llx, length %d\n", rq->sdno, rq, rq->bp->b_flags & B_READ ? "Read" : "Write", major(rq->bp->b_dev), minor(rq->bp->b_dev), rq->bp->b_blkno, rq->bp->b_bcount); #endif return 0; /* and get out of here */ } rq->active = 0; /* nothing yet */ #ifdef VINUMDEBUG /* XXX This is probably due to a bug */ if (rq->rqg == NULL) { /* no request */ log(LOG_ERR, "vinum: null rqg\n"); abortrequest(rq, EINVAL); return -1; } #endif #ifdef VINUMDEBUG if (debug & DEBUG_ADDRESSES) log(LOG_DEBUG, "Request: %p\n%s dev %d.%d, offset 0x%llx, length %d\n", rq, rq->bp->b_flags & B_READ ? "Read" : "Write", major(rq->bp->b_dev), minor(rq->bp->b_dev), rq->bp->b_blkno, rq->bp->b_bcount); vinum_conf.lastrq = rq; vinum_conf.lastbuf = rq->bp; if (debug & DEBUG_LASTREQS) logrq(loginfo_user_bpl, (union rqinfou) rq->bp, rq->bp); #endif /* * We used to have an splbio() here anyway, out * of superstition. With the division of labour * below (first count the requests, then issue * them), it looks as if we don't need this * splbio() protection. In fact, as dillon * points out, there's a race condition * incrementing and decrementing rq->active and * rqg->active. This splbio() didn't help * there, because the device strategy routine * can sleep. Solve this by putting shorter * duration locks on the code. */ /* * This loop happens without any participation * of the bottom half, so it requires no * protection. */ for (rqg = rq->rqg; rqg != NULL; rqg = rqg->next) { /* through the whole request chain */ rqg->active = rqg->count; /* they're all active */ for (rqno = 0; rqno < rqg->count; rqno++) { rqe = &rqg->rqe[rqno]; if (rqe->flags & XFR_BAD_SUBDISK) /* this subdisk is bad, */ rqg->active--; /* one less active request */ } if (rqg->active) /* we have at least one active request, */ rq->active++; /* one more active request group */ } /* * Now fire off the requests. In this loop the * bottom half could be completing requests * before we finish. We avoid splbio() * protection by ensuring we don't tread in the * same places that the bottom half does. */ for (rqg = rq->rqg; rqg != NULL;) { /* through the whole request chain */ if (rqg->lockbase >= 0) /* this rqg needs a lock first */ rqg->lock = lockrange(rqg->lockbase, rqg->rq->bp, &PLEX[rqg->plexno]); rcount = rqg->count; for (rqno = 0; rqno < rcount;) { rqe = &rqg->rqe[rqno]; /* * Point to next rqg before the bottom half * changes the structures. */ if (++rqno >= rcount) rqg = rqg->next; if ((rqe->flags & XFR_BAD_SUBDISK) == 0) { /* this subdisk is good, */ drive = &DRIVE[rqe->driveno]; /* look at drive */ drive->active++; if (drive->active >= drive->maxactive) drive->maxactive = drive->active; vinum_conf.active++; if (vinum_conf.active >= vinum_conf.maxactive) vinum_conf.maxactive = vinum_conf.active; #ifdef VINUMDEBUG if (debug & DEBUG_ADDRESSES) log(LOG_DEBUG, " %s dev %d.%d, sd %d, offset 0x%x, devoffset 0x%llx, length %d\n", rqe->b.b_flags & B_READ ? "Read" : "Write", major(rqe->b.b_dev), minor(rqe->b.b_dev), rqe->sdno, (u_int) (rqe->b.b_blkno - SD[rqe->sdno].driveoffset), rqe->b.b_blkno, rqe->b.b_bcount); if (debug & DEBUG_LASTREQS) { microtime(&rqe->launchtime); /* time we launched this request */ logrq(loginfo_rqe, (union rqinfou) rqe, rq->bp); } #endif /* fire off the request */ bdev = bdevsw_lookup(rqe->b.b_dev); if (bdev == NULL) panic("no bdev"); /* FIXME XXX */ (*bdev->d_strategy) (&rqe->b); } } } return 0; } /* * define the low-level requests needed to perform a * high-level I/O operation for a specific plex 'plexno'. * * Return REQUEST_OK if all subdisks involved in the request are up, * REQUEST_DOWN if some subdisks are not up, and REQUEST_EOF if the * request is at least partially outside the bounds of the subdisks. * * Modify the pointer *diskstart to point to the end address. On * read, return on the first bad subdisk, so that the caller * (build_read_request) can try alternatives. * * On entry to this routine, the rqg structures are not assigned. The * assignment is performed by expandrq(). Strictly speaking, the * elements rqe->sdno of all entries should be set to -1, since 0 * (from bzero) is a valid subdisk number. We avoid this problem by * initializing the ones we use, and not looking at the others (index * >= rqg->requests). */ enum requeststatus bre(struct request *rq, int plexno, daddr_t * diskaddr, daddr_t diskend) { int sdno; struct sd *sd; struct rqgroup *rqg; struct buf *bp; /* user's bp */ struct plex *plex; enum requeststatus status; /* return value */ daddr_t plexoffset; /* offset of transfer in plex */ daddr_t stripebase; /* base address of stripe (1st subdisk) */ daddr_t stripeoffset; /* offset in stripe */ daddr_t blockoffset; /* offset in stripe on subdisk */ struct rqelement *rqe; /* point to this request information */ daddr_t diskstart = *diskaddr; /* remember where this transfer starts */ enum requeststatus s; /* temp return value */ bp = rq->bp; /* buffer pointer */ status = REQUEST_OK; /* return value: OK until proven otherwise */ plex = &PLEX[plexno]; /* point to the plex */ switch (plex->organization) { case plex_concat: sd = NULL; /* (keep compiler quiet) */ for (sdno = 0; sdno < plex->subdisks; sdno++) { sd = &SD[plex->sdnos[sdno]]; if (*diskaddr < sd->plexoffset) /* we must have a hole, */ status = REQUEST_DEGRADED; /* note the fact */ if (*diskaddr < (sd->plexoffset + sd->sectors)) { /* the request starts in this subdisk */ rqg = allocrqg(rq, 1); /* space for the request */ if (rqg == NULL) { /* malloc failed */ bp->b_error = ENOMEM; bp->b_flags |= B_ERROR; return REQUEST_ENOMEM; } rqg->plexno = plexno; rqe = &rqg->rqe[0]; /* point to the element */ rqe->rqg = rqg; /* group */ rqe->sdno = sd->sdno; /* put in the subdisk number */ plexoffset = *diskaddr; /* start offset in plex */ rqe->sdoffset = plexoffset - sd->plexoffset; /* start offset in subdisk */ rqe->useroffset = plexoffset - diskstart; /* start offset in user buffer */ rqe->dataoffset = 0; rqe->datalen = min(diskend - *diskaddr, /* number of sectors to transfer in this sd */ sd->sectors - rqe->sdoffset); rqe->groupoffset = 0; /* no groups for concatenated plexes */ rqe->grouplen = 0; rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ rqe->flags = 0; rqe->driveno = sd->driveno; if (sd->state != sd_up) { /* *now* we find the sd is down */ s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ if (s == REQUEST_DOWN) { /* down? */ rqe->flags = XFR_BAD_SUBDISK; /* yup */ if (rq->bp->b_flags & B_READ) /* read request, */ return REQUEST_DEGRADED; /* give up here */ /* * If we're writing, don't give up * because of a bad subdisk. Go * through to the bitter end, but note * which ones we can't access. */ status = REQUEST_DEGRADED; /* can't do it all */ } } *diskaddr += rqe->datalen; /* bump the address */ if (build_rq_buffer(rqe, plex)) { /* build the buffer */ deallocrqg(rqg); bp->b_error = ENOMEM; bp->b_flags |= B_ERROR; return REQUEST_ENOMEM; /* can't do it */ } } if (*diskaddr == diskend) /* we're finished, */ break; /* get out of here */ } /* * We've got to the end of the plex. Have we got to the end of * the transfer? It would seem that having an offset beyond the * end of the subdisk is an error, but in fact it can happen if * the volume has another plex of different size. There's a valid * question as to why you would want to do this, but currently * it's allowed. * * In a previous version, I returned REQUEST_DOWN here. I think * REQUEST_EOF is more appropriate now. */ if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */ status = REQUEST_EOF; break; case plex_striped: { while (*diskaddr < diskend) { /* until we get it all sorted out */ if (*diskaddr >= plex->length) /* beyond the end of the plex */ return REQUEST_EOF; /* can't continue */ /* The offset of the start address from the start of the stripe. */ stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks); /* The plex-relative address of the start of the stripe. */ stripebase = *diskaddr - stripeoffset; /* The number of the subdisk in which the start is located. */ sdno = stripeoffset / plex->stripesize; /* The offset from the beginning of the stripe on this subdisk. */ blockoffset = stripeoffset % plex->stripesize; sd = &SD[plex->sdnos[sdno]]; /* the subdisk in question */ rqg = allocrqg(rq, 1); /* space for the request */ if (rqg == NULL) { /* malloc failed */ bp->b_error = ENOMEM; bp->b_flags |= B_ERROR; return REQUEST_ENOMEM; } rqg->plexno = plexno; rqe = &rqg->rqe[0]; /* point to the element */ rqe->rqg = rqg; rqe->sdoffset = stripebase / plex->subdisks + blockoffset; /* start offset in this subdisk */ rqe->useroffset = *diskaddr - diskstart; /* The offset of the start in the user buffer */ rqe->dataoffset = 0; rqe->datalen = min(diskend - *diskaddr, /* the amount remaining to transfer */ plex->stripesize - blockoffset); /* and the amount left in this stripe */ rqe->groupoffset = 0; /* no groups for striped plexes */ rqe->grouplen = 0; rqe->buflen = rqe->datalen; /* buffer length is data buffer length */ rqe->flags = 0; rqe->sdno = sd->sdno; /* put in the subdisk number */ rqe->driveno = sd->driveno; if (sd->state != sd_up) { /* *now* we find the sd is down */ s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */ if (s == REQUEST_DOWN) { /* down? */ rqe->flags = XFR_BAD_SUBDISK; /* yup */ if (rq->bp->b_flags & B_READ) /* read request, */ return REQUEST_DEGRADED; /* give up here */ /* * If we're writing, don't give up * because of a bad subdisk. Go through * to the bitter end, but note which * ones we can't access. */ status = REQUEST_DEGRADED; /* can't do it all */ } } /* * It would seem that having an offset * beyond the end of the subdisk is an * error, but in fact it can happen if the * volume has another plex of different * size. There's a valid question as to why * you would want to do this, but currently * it's allowed. */ if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */ rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */ #ifdef VINUMDEBUG if (debug & DEBUG_EOFINFO) { /* tell on the request */ log(LOG_DEBUG, "vinum: EOF on plex %s, sd %s offset %x (user offset 0x%llx)\n", plex->name, sd->name, (u_int) sd->sectors, bp->b_blkno); log(LOG_DEBUG, "vinum: stripebase 0x%llx, stripeoffset 0x%llx, blockoffset 0x%llx\n", stripebase, stripeoffset, blockoffset); } #endif } if (build_rq_buffer(rqe, plex)) { /* build the buffer */ deallocrqg(rqg); bp->b_error = ENOMEM; bp->b_flags |= B_ERROR; return REQUEST_ENOMEM; /* can't do it */ } *diskaddr += rqe->datalen; /* look at the remainder */ if ((*diskaddr < diskend) /* didn't finish the request on this stripe */ &&(*diskaddr < plex->length)) { /* and there's more to come */ plex->multiblock++; /* count another one */ if (sdno == plex->subdisks - 1) /* last subdisk, */ plex->multistripe++; /* another stripe as well */ } } } break; /* * RAID-4 and RAID-5 are complicated enough to have their own * function. */ case plex_raid4: case plex_raid5: status = bre5(rq, plexno, diskaddr, diskend); break; default: log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization); status = REQUEST_DOWN; /* can't access it */ } return status; } /* * Build up a request structure for reading volumes. * This function is not needed for plex reads, since there's * no recovery if a plex read can't be satisified. */ enum requeststatus build_read_request(struct request *rq, /* request */ int plexindex) { /* index in the volume's plex table */ struct buf *bp; daddr_t startaddr; /* offset of previous part of transfer */ daddr_t diskaddr; /* offset of current part of transfer */ daddr_t diskend; /* and end offset of transfer */ int plexno; /* plex index in vinum_conf */ struct rqgroup *rqg; /* point to the request we're working on */ struct volume *vol; /* volume in question */ int recovered = 0; /* set if we recover a read */ enum requeststatus status = REQUEST_OK; int plexmask; /* bit mask of plexes, for recovery */ bp = rq->bp; /* buffer pointer */ diskaddr = bp->b_blkno; /* start offset of transfer */ diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */ rqg = &rq->rqg[plexindex]; /* plex request */ vol = &VOL[rq->volplex.volno]; /* point to volume */ while (diskaddr < diskend) { /* build up request components */ startaddr = diskaddr; status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */ switch (status) { case REQUEST_OK: continue; case REQUEST_RECOVERED: /* * XXX FIXME if we have more than one plex, and we can * satisfy the request from another, don't use the * recovered request, since it's more expensive. */ recovered = 1; break; case REQUEST_ENOMEM: return status; /* * If we get here, our request is not complete. Try * to fill in the missing parts from another plex. * This can happen multiple times in this function, * and we reinitialize the plex mask each time, since * we could have a hole in our plexes. */ case REQUEST_EOF: case REQUEST_DOWN: /* can't access the plex */ case REQUEST_DEGRADED: /* can't access the plex */ plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */ &~(1 << plexindex); /* except for the one we were looking at */ for (plexno = 0; plexno < vol->plexes; plexno++) { if (plexmask == 0) /* no plexes left to try */ return REQUEST_DOWN; /* failed */ diskaddr = startaddr; /* start at the beginning again */ if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */ bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */ if (diskaddr > startaddr) { /* we satisfied another part */ recovered = 1; /* we recovered from the problem */ status = REQUEST_OK; /* don't complain about it */ break; } } } if (diskaddr == startaddr) /* didn't get any further, */ return status; } if (recovered) vol->recovered_reads += recovered; /* adjust our recovery count */ } return status; } /* * Build up a request structure for writes. * Return 0 if all subdisks involved in the request are up, 1 if some * subdisks are not up, and -1 if the request is at least partially * outside the bounds of the subdisks. */ enum requeststatus build_write_request(struct request *rq) { /* request */ struct buf *bp; daddr_t diskstart; /* offset of current part of transfer */ daddr_t diskend; /* and end offset of transfer */ int plexno; /* plex index in vinum_conf */ struct volume *vol; /* volume in question */ enum requeststatus status; bp = rq->bp; /* buffer pointer */ vol = &VOL[rq->volplex.volno]; /* point to volume */ diskend = bp->b_blkno + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */ status = REQUEST_DOWN; /* assume the worst */ for (plexno = 0; plexno < vol->plexes; plexno++) { diskstart = bp->b_blkno; /* start offset of transfer */ /* * Build requests for the plex. * We take the best possible result here (min, * not max): we're happy if we can write at all */ status = min(status, bre(rq, vol->plex[plexno], &diskstart, diskend)); } return status; } /* Fill in the struct buf part of a request element. */ enum requeststatus build_rq_buffer(struct rqelement *rqe, struct plex *plex) { struct sd *sd; /* point to subdisk */ struct volume *vol; struct buf *bp; struct buf *ubp; /* user (high level) buffer header */ vol = &VOL[rqe->rqg->rq->volplex.volno]; sd = &SD[rqe->sdno]; /* point to subdisk */ bp = &rqe->b; ubp = rqe->rqg->rq->bp; /* pointer to user buffer header */ /* Initialize the buf struct */ /* copy these flags from user bp */ bp->b_flags = ubp->b_flags & (B_NOCACHE | B_READ | B_ASYNC); bp->b_flags |= B_CALL | B_BUSY; /* inform us when it's done */ bp->b_iodone = complete_rqe; /* * You'd think that we wouldn't need to even * build the request buffer for a dead subdisk, * but in some cases we need information like * the user buffer address. Err on the side of * generosity and supply what we can. That * obviously doesn't include drive information * when the drive is dead. */ if ((rqe->flags & XFR_BAD_SUBDISK) == 0) /* subdisk is accessible, */ bp->b_dev = DRIVE[rqe->driveno].dev; /* drive device */ bp->b_blkno = rqe->sdoffset + sd->driveoffset; /* start address */ bp->b_bcount = rqe->buflen << DEV_BSHIFT; /* number of bytes to transfer */ bp->b_resid = bp->b_bcount; /* and it's still all waiting */ bp->b_bufsize = bp->b_bcount; /* and buffer size */ if (rqe->flags & XFR_MALLOCED) { /* this operation requires a malloced buffer */ bp->b_data = Malloc(bp->b_bcount); /* get a buffer to put it in */ if (bp->b_data == NULL) { /* failed */ abortrequest(rqe->rqg->rq, ENOMEM); return REQUEST_ENOMEM; /* no memory */ } } else /* * Point directly to user buffer data. This means * that we don't need to do anything when we have * finished the transfer */ bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE; /* * On a recovery read, we perform an XOR of * all blocks to the user buffer. To make * this work, we first clean out the buffer */ if ((rqe->flags & (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) == (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) { /* bad subdisk of a recovery read */ int length = rqe->grouplen << DEV_BSHIFT; /* and count involved */ char *data = (char *) &rqe->b.b_data[rqe->groupoffset << DEV_BSHIFT]; /* destination */ bzero(data, length); /* clean it out */ } return 0; } /* * Abort a request: free resources and complete the * user request with the specified error */ int abortrequest(struct request *rq, int error) { struct buf *bp = rq->bp; /* user buffer */ bp->b_error = error; freerq(rq); /* free everything we're doing */ bp->b_flags |= B_ERROR; return error; /* and give up */ } /* * Check that our transfer will cover the * complete address space of the user request. * * Return 1 if it can, otherwise 0 */ int check_range_covered(struct request *rq) { return 1; } /* Perform I/O on a subdisk */ void sdio(struct buf *bp) { int s; /* spl */ struct sd *sd; struct sdbuf *sbp; daddr_t endoffset; struct drive *drive; const struct bdevsw *bdev; #ifdef VINUMDEBUG if (debug & DEBUG_LASTREQS) logrq(loginfo_sdio, (union rqinfou) bp, bp); #endif sd = &SD[Sdno(bp->b_dev)]; /* point to the subdisk */ drive = &DRIVE[sd->driveno]; if (drive->state != drive_up) { if (sd->state >= sd_crashed) { if ((bp->b_flags & B_READ) == 0) /* writing, */ set_sd_state(sd->sdno, sd_stale, setstate_force); else set_sd_state(sd->sdno, sd_crashed, setstate_force); } bp->b_error = EIO; bp->b_flags |= B_ERROR; biodone(bp); return; } /* * We allow access to any kind of subdisk as long as we can expect * to get the I/O performed. */ if (sd->state < sd_empty) { /* nothing to talk to, */ bp->b_error = EIO; bp->b_flags |= B_ERROR; biodone(bp); return; } /* Get a buffer */ sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf)); if (sbp == NULL) { bp->b_error = ENOMEM; bp->b_flags |= B_ERROR; biodone(bp); return; } bzero(sbp, sizeof(struct sdbuf)); /* start with nothing */ sbp->b.b_flags = bp->b_flags | B_CALL | B_BUSY; /* inform us when it's done */ sbp->b.b_bufsize = bp->b_bcount; /* buffer size */ sbp->b.b_bcount = bp->b_bcount; /* number of bytes to transfer */ sbp->b.b_resid = bp->b_resid; /* and amount waiting */ sbp->b.b_dev = DRIVE[sd->driveno].dev; /* device */ sbp->b.b_data = bp->b_data; /* data buffer */ sbp->b.b_blkno = bp->b_blkno + sd->driveoffset; sbp->b.b_iodone = sdio_done; /* come here on completion */ sbp->bp = bp; /* note the address of the original header */ sbp->sdno = sd->sdno; /* note for statistics */ sbp->driveno = sd->driveno; endoffset = bp->b_blkno + sbp->b.b_bcount / DEV_BSIZE; /* final sector offset */ if (endoffset > sd->sectors) { /* beyond the end */ sbp->b.b_bcount -= (endoffset - sd->sectors) * DEV_BSIZE; /* trim */ if (sbp->b.b_bcount <= 0) { /* nothing to transfer */ bp->b_resid = bp->b_bcount; /* nothing transferred */ biodone(bp); Free(sbp); return; } } #ifdef VINUMDEBUG if (debug & DEBUG_ADDRESSES) log(LOG_DEBUG, " %s dev %d.%d, sd %d, offset 0x%llx, devoffset 0x%llx, length %d\n", sbp->b.b_flags & B_READ ? "Read" : "Write", major(sbp->b.b_dev), minor(sbp->b.b_dev), sbp->sdno, sbp->b.b_blkno - SD[sbp->sdno].driveoffset, sbp->b.b_blkno, sbp->b.b_bcount); #endif s = splbio(); #ifdef VINUMDEBUG if (debug & DEBUG_LASTREQS) logrq(loginfo_sdiol, (union rqinfou) &sbp->b, &sbp->b); #endif bdev = bdevsw_lookup(sbp->b.b_dev); if (bdev == NULL) panic("no buf"); /* XXX FIXME */ (*bdev->d_strategy) (&sbp->b); splx(s); } /* * Simplified version of bounds_check_with_label * Determine the size of the transfer, and make sure it is * within the boundaries of the partition. Adjust transfer * if needed, and signal errors or early completion. * * Volumes are simpler than disk slices: they only contain * one component (though we call them a, b and c to make * system utilities happy), and they always take up the * complete space of the "partition". * * I'm still not happy with this: why should the label be * protected? If it weren't so damned difficult to write * one in the first pleace (because it's protected), it wouldn't * be a problem. */ int vinum_bounds_check(struct buf *bp, struct volume *vol) { int maxsize = vol->size; /* size of the partition (sectors) */ int size = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* size of this request (sectors) */ /* Would this transfer overwrite the disk label? */ if (bp->b_blkno <= LABELSECTOR /* starts before or at the label */ #if LABELSECTOR != 0 && bp->b_blkno + size > LABELSECTOR /* and finishes after */ #endif && (!(vol->flags & VF_RAW)) /* and it's not raw */ &&major(bp->b_dev) == VINUM_BDEV_MAJOR /* and it's the block device */ && ((bp->b_flags & B_READ) == 0) /* and it's a write */ &&(!vol->flags & (VF_WLABEL | VF_LABELLING))) { /* and we're not allowed to write the label */ bp->b_error = EROFS; /* read-only */ bp->b_flags |= B_ERROR; return -1; } if (size == 0) /* no transfer specified, */ return 0; /* treat as EOF */ /* beyond partition? */ if (bp->b_blkno < 0 /* negative start */ || bp->b_blkno + size > maxsize) { /* or goes beyond the end of the partition */ /* if exactly at end of disk, return an EOF */ if (bp->b_blkno == maxsize) { bp->b_resid = bp->b_bcount; return 0; } /* or truncate if part of it fits */ size = maxsize - bp->b_blkno; if (size <= 0) { /* nothing to transfer */ bp->b_error = EINVAL; bp->b_flags |= B_ERROR; return -1; } bp->b_bcount = size << DEV_BSHIFT; } return 1; } /* * Allocate a request group and hook * it in in the list for rq */ struct rqgroup * allocrqg(struct request *rq, int elements) { struct rqgroup *rqg; /* the one we're going to allocate */ int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement); rqg = (struct rqgroup *) Malloc(size); if (rqg != NULL) { /* malloc OK, */ if (rq->rqg) /* we already have requests */ rq->lrqg->next = rqg; /* hang it off the end */ else /* first request */ rq->rqg = rqg; /* at the start */ rq->lrqg = rqg; /* this one is the last in the list */ bzero(rqg, size); /* no old junk */ rqg->rq = rq; /* point back to the parent request */ rqg->count = elements; /* number of requests in the group */ rqg->lockbase = -1; /* no lock required yet */ } return rqg; } /* * Deallocate a request group out of a chain. We do * this by linear search: the chain is short, this * almost never happens, and currently it can only * happen to the first member of the chain. */ void deallocrqg(struct rqgroup *rqg) { struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */ if (rqg->lock) /* got a lock? */ unlockrange(rqg->plexno, rqg->lock); /* yes, free it */ if (rqgc == rqg) /* we're first in line */ rqg->rq->rqg = rqg->next; /* unhook ourselves */ else { while ((rqgc->next != NULL) /* find the group */ &&(rqgc->next != rqg)) rqgc = rqgc->next; if (rqgc->next == NULL) log(LOG_ERR, "vinum deallocrqg: rqg %p not found in request %p\n", rqg->rq, rqg); else rqgc->next = rqg->next; /* make the chain jump over us */ } Free(rqg); } /* Character device interface */ int vinumread(dev_t dev, struct uio *uio, int ioflag) { return (physio(vinumstrategy, NULL, dev, B_READ, minphys, uio)); } int vinumwrite(dev_t dev, struct uio *uio, int ioflag) { return (physio(vinumstrategy, NULL, dev, B_WRITE, minphys, uio)); } /* Local Variables: */ /* fill-column: 50 */ /* End: */