/*- * Copyright (c) 2004, 2007 Lukas Ertl * All rights reserved. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include static int gv_raid5_offset(struct gv_plex *, off_t, off_t, off_t *, off_t *, int *, int *, int); static struct bio * gv_raid5_clone_bio(struct bio *, struct gv_sd *, struct gv_raid5_packet *, caddr_t, int); static int gv_raid5_request(struct gv_plex *, struct gv_raid5_packet *, struct bio *, caddr_t, off_t, off_t, int *); static int gv_raid5_check(struct gv_plex *, struct gv_raid5_packet *, struct bio *, caddr_t, off_t, off_t); static int gv_raid5_rebuild(struct gv_plex *, struct gv_raid5_packet *, struct bio *, caddr_t, off_t, off_t); struct gv_raid5_packet * gv_raid5_start(struct gv_plex *p, struct bio *bp, caddr_t addr, off_t boff, off_t bcount) { struct bio *cbp; struct gv_raid5_packet *wp, *wp2; struct gv_bioq *bq, *bq2; int err, delay; delay = 0; wp = g_malloc(sizeof(*wp), M_WAITOK | M_ZERO); wp->bio = bp; wp->waiting = NULL; wp->parity = NULL; TAILQ_INIT(&wp->bits); if (bp->bio_pflags & GV_BIO_REBUILD) err = gv_raid5_rebuild(p, wp, bp, addr, boff, bcount); else if (bp->bio_pflags & GV_BIO_CHECK) err = gv_raid5_check(p, wp, bp, addr, boff, bcount); else err = gv_raid5_request(p, wp, bp, addr, boff, bcount, &delay); /* Means we have a delayed request. */ if (delay) { g_free(wp); return (NULL); } /* * Building the sub-request failed, we probably need to clean up a lot. */ if (err) { G_VINUM_LOGREQ(0, bp, "raid5 plex request failed."); TAILQ_FOREACH_SAFE(bq, &wp->bits, queue, bq2) { TAILQ_REMOVE(&wp->bits, bq, queue); g_free(bq); } if (wp->waiting != NULL) { if (wp->waiting->bio_cflags & GV_BIO_MALLOC) g_free(wp->waiting->bio_data); g_destroy_bio(wp->waiting); } if (wp->parity != NULL) { if (wp->parity->bio_cflags & GV_BIO_MALLOC) g_free(wp->parity->bio_data); g_destroy_bio(wp->parity); } g_free(wp); TAILQ_FOREACH_SAFE(wp, &p->packets, list, wp2) { if (wp->bio != bp) continue; TAILQ_REMOVE(&p->packets, wp, list); TAILQ_FOREACH_SAFE(bq, &wp->bits, queue, bq2) { TAILQ_REMOVE(&wp->bits, bq, queue); g_free(bq); } g_free(wp); } cbp = bioq_takefirst(p->bqueue); while (cbp != NULL) { if (cbp->bio_cflags & GV_BIO_MALLOC) g_free(cbp->bio_data); g_destroy_bio(cbp); cbp = bioq_takefirst(p->bqueue); } /* If internal, stop and reset state. */ if (bp->bio_pflags & GV_BIO_INTERNAL) { if (bp->bio_pflags & GV_BIO_MALLOC) g_free(bp->bio_data); g_destroy_bio(bp); /* Reset flags. */ p->flags &= ~(GV_PLEX_SYNCING | GV_PLEX_REBUILDING | GV_PLEX_GROWING); return (NULL); } g_io_deliver(bp, err); return (NULL); } return (wp); } /* * Check if the stripe that the work packet wants is already being used by * some other work packet. */ int gv_stripe_active(struct gv_plex *p, struct bio *bp) { struct gv_raid5_packet *wp, *owp; int overlap; wp = bp->bio_caller2; if (wp->lockbase == -1) return (0); overlap = 0; TAILQ_FOREACH(owp, &p->packets, list) { if (owp == wp) break; if ((wp->lockbase >= owp->lockbase) && (wp->lockbase <= owp->lockbase + owp->length)) { overlap++; break; } if ((wp->lockbase <= owp->lockbase) && (wp->lockbase + wp->length >= owp->lockbase)) { overlap++; break; } } return (overlap); } static int gv_raid5_check(struct gv_plex *p, struct gv_raid5_packet *wp, struct bio *bp, caddr_t addr, off_t boff, off_t bcount) { struct gv_sd *parity, *s; struct gv_bioq *bq; struct bio *cbp; int i, psdno; off_t real_len, real_off; if (p == NULL || LIST_EMPTY(&p->subdisks)) return (ENXIO); gv_raid5_offset(p, boff, bcount, &real_off, &real_len, NULL, &psdno, 1); /* Find the right subdisk. */ parity = NULL; i = 0; LIST_FOREACH(s, &p->subdisks, in_plex) { if (i == psdno) { parity = s; break; } i++; } /* Parity stripe not found. */ if (parity == NULL) return (ENXIO); if (parity->state != GV_SD_UP) return (ENXIO); wp->length = real_len; wp->data = addr; wp->lockbase = real_off; /* Read all subdisks. */ LIST_FOREACH(s, &p->subdisks, in_plex) { /* Skip the parity subdisk. */ if (s == parity) continue; /* Skip growing subdisks. */ if (s->flags & GV_SD_GROW) continue; cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); cbp->bio_cmd = BIO_READ; bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); } /* Read the parity data. */ cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); cbp->bio_cmd = BIO_READ; wp->waiting = cbp; /* * In case we want to rebuild the parity, create an extra BIO to write * it out. It also acts as buffer for the XOR operations. */ cbp = gv_raid5_clone_bio(bp, parity, wp, addr, 1); if (cbp == NULL) return (ENOMEM); wp->parity = cbp; return (0); } /* Rebuild a degraded RAID5 plex. */ static int gv_raid5_rebuild(struct gv_plex *p, struct gv_raid5_packet *wp, struct bio *bp, caddr_t addr, off_t boff, off_t bcount) { struct gv_sd *broken, *s; struct gv_bioq *bq; struct bio *cbp; off_t real_len, real_off; if (p == NULL || LIST_EMPTY(&p->subdisks)) return (ENXIO); gv_raid5_offset(p, boff, bcount, &real_off, &real_len, NULL, NULL, 1); /* Find the right subdisk. */ broken = NULL; LIST_FOREACH(s, &p->subdisks, in_plex) { if (s->state != GV_SD_UP) broken = s; } /* Broken stripe not found. */ if (broken == NULL) return (ENXIO); switch (broken->state) { case GV_SD_UP: return (EINVAL); case GV_SD_STALE: if (!(bp->bio_pflags & GV_BIO_REBUILD)) return (ENXIO); G_VINUM_DEBUG(1, "sd %s is reviving", broken->name); gv_set_sd_state(broken, GV_SD_REVIVING, GV_SETSTATE_FORCE); /* Set this bit now, but should be set at end. */ broken->flags |= GV_SD_CANGOUP; break; case GV_SD_REVIVING: break; default: /* All other subdisk states mean it's not accessible. */ return (ENXIO); } wp->length = real_len; wp->data = addr; wp->lockbase = real_off; KASSERT(wp->length >= 0, ("gv_rebuild_raid5: wp->length < 0")); /* Read all subdisks. */ LIST_FOREACH(s, &p->subdisks, in_plex) { /* Skip the broken subdisk. */ if (s == broken) continue; /* Skip growing subdisks. */ if (s->flags & GV_SD_GROW) continue; cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); cbp->bio_cmd = BIO_READ; bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); } /* Write the parity data. */ cbp = gv_raid5_clone_bio(bp, broken, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); wp->parity = cbp; p->synced = boff; /* Post notification that we're finished. */ return (0); } /* Build a request group to perform (part of) a RAID5 request. */ static int gv_raid5_request(struct gv_plex *p, struct gv_raid5_packet *wp, struct bio *bp, caddr_t addr, off_t boff, off_t bcount, int *delay) { struct g_geom *gp; struct gv_sd *broken, *original, *parity, *s; struct gv_bioq *bq; struct bio *cbp; int i, psdno, sdno, type, grow; off_t real_len, real_off; gp = bp->bio_to->geom; if (p == NULL || LIST_EMPTY(&p->subdisks)) return (ENXIO); /* We are optimistic and assume that this request will be OK. */ #define REQ_TYPE_NORMAL 0 #define REQ_TYPE_DEGRADED 1 #define REQ_TYPE_NOPARITY 2 type = REQ_TYPE_NORMAL; original = parity = broken = NULL; /* XXX: The resize won't crash with rebuild or sync, but we should still * be aware of it. Also this should perhaps be done on rebuild/check as * well? */ /* If we're over, we must use the old. */ if (boff >= p->synced) { grow = 1; /* Or if over the resized offset, we use all drives. */ } else if (boff + bcount <= p->synced) { grow = 0; /* Else, we're in the middle, and must wait a bit. */ } else { bioq_disksort(p->rqueue, bp); *delay = 1; return (0); } gv_raid5_offset(p, boff, bcount, &real_off, &real_len, &sdno, &psdno, grow); /* Find the right subdisks. */ i = 0; LIST_FOREACH(s, &p->subdisks, in_plex) { if (i == sdno) original = s; if (i == psdno) parity = s; if (s->state != GV_SD_UP) broken = s; i++; } if ((original == NULL) || (parity == NULL)) return (ENXIO); /* Our data stripe is missing. */ if (original->state != GV_SD_UP) type = REQ_TYPE_DEGRADED; /* If synchronizing request, just write it if disks are stale. */ if (original->state == GV_SD_STALE && parity->state == GV_SD_STALE && bp->bio_pflags & GV_BIO_SYNCREQ && bp->bio_cmd == BIO_WRITE) { type = REQ_TYPE_NORMAL; /* Our parity stripe is missing. */ } else if (parity->state != GV_SD_UP) { /* We cannot take another failure if we're already degraded. */ if (type != REQ_TYPE_NORMAL) return (ENXIO); else type = REQ_TYPE_NOPARITY; } wp->length = real_len; wp->data = addr; wp->lockbase = real_off; KASSERT(wp->length >= 0, ("gv_build_raid5_request: wp->length < 0")); if ((p->flags & GV_PLEX_REBUILDING) && (boff + real_len < p->synced)) type = REQ_TYPE_NORMAL; if ((p->flags & GV_PLEX_REBUILDING) && (boff + real_len >= p->synced)) { bioq_disksort(p->rqueue, bp); *delay = 1; return (0); } switch (bp->bio_cmd) { case BIO_READ: /* * For a degraded read we need to read in all stripes except * the broken one plus the parity stripe and then recalculate * the desired data. */ if (type == REQ_TYPE_DEGRADED) { bzero(wp->data, wp->length); LIST_FOREACH(s, &p->subdisks, in_plex) { /* Skip the broken subdisk. */ if (s == broken) continue; /* Skip growing if within offset. */ if (grow && s->flags & GV_SD_GROW) continue; cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); } /* A normal read can be fulfilled with the original subdisk. */ } else { cbp = gv_raid5_clone_bio(bp, original, wp, addr, 0); if (cbp == NULL) return (ENOMEM); bioq_insert_tail(p->bqueue, cbp); } wp->lockbase = -1; break; case BIO_WRITE: /* * A degraded write means we cannot write to the original data * subdisk. Thus we need to read in all valid stripes, * recalculate the parity from the original data, and then * write the parity stripe back out. */ if (type == REQ_TYPE_DEGRADED) { /* Read all subdisks. */ LIST_FOREACH(s, &p->subdisks, in_plex) { /* Skip the broken and the parity subdisk. */ if ((s == broken) || (s == parity)) continue; /* Skip growing if within offset. */ if (grow && s->flags & GV_SD_GROW) continue; cbp = gv_raid5_clone_bio(bp, s, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); cbp->bio_cmd = BIO_READ; bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); } /* Write the parity data. */ cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); bcopy(addr, cbp->bio_data, wp->length); wp->parity = cbp; /* * When the parity stripe is missing we just write out the data. */ } else if (type == REQ_TYPE_NOPARITY) { cbp = gv_raid5_clone_bio(bp, original, wp, addr, 1); if (cbp == NULL) return (ENOMEM); bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); /* * A normal write request goes to the original subdisk, then we * read in all other stripes, recalculate the parity and write * out the parity again. */ } else { /* Read old parity. */ cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); cbp->bio_cmd = BIO_READ; bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); /* Read old data. */ cbp = gv_raid5_clone_bio(bp, original, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); cbp->bio_cmd = BIO_READ; bioq_insert_tail(p->bqueue, cbp); bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO); bq->bp = cbp; TAILQ_INSERT_TAIL(&wp->bits, bq, queue); /* Write new data. */ cbp = gv_raid5_clone_bio(bp, original, wp, addr, 1); if (cbp == NULL) return (ENOMEM); /* * We must not write the new data until the old data * was read, so hold this BIO back until we're ready * for it. */ wp->waiting = cbp; /* The final bio for the parity. */ cbp = gv_raid5_clone_bio(bp, parity, wp, NULL, 1); if (cbp == NULL) return (ENOMEM); /* Remember that this is the BIO for the parity data. */ wp->parity = cbp; } break; default: return (EINVAL); } return (0); } /* * Calculate the offsets in the various subdisks for a RAID5 request. Also take * care of new subdisks in an expanded RAID5 array. * XXX: This assumes that the new subdisks are inserted after the others (which * is okay as long as plex_offset is larger). If subdisks are inserted into the * plexlist before, we get problems. */ static int gv_raid5_offset(struct gv_plex *p, off_t boff, off_t bcount, off_t *real_off, off_t *real_len, int *sdno, int *psdno, int growing) { struct gv_sd *s; int sd, psd, sdcount; off_t len_left, stripeend, stripeoff, stripestart; sdcount = p->sdcount; if (growing) { LIST_FOREACH(s, &p->subdisks, in_plex) { if (s->flags & GV_SD_GROW) sdcount--; } } /* The number of the subdisk containing the parity stripe. */ psd = sdcount - 1 - ( boff / (p->stripesize * (sdcount - 1))) % sdcount; KASSERT(psdno >= 0, ("gv_raid5_offset: psdno < 0")); /* Offset of the start address from the start of the stripe. */ stripeoff = boff % (p->stripesize * (sdcount - 1)); KASSERT(stripeoff >= 0, ("gv_raid5_offset: stripeoff < 0")); /* The number of the subdisk where the stripe resides. */ sd = stripeoff / p->stripesize; KASSERT(sdno >= 0, ("gv_raid5_offset: sdno < 0")); /* At or past parity subdisk. */ if (sd >= psd) sd++; /* The offset of the stripe on this subdisk. */ stripestart = (boff - stripeoff) / (sdcount - 1); KASSERT(stripestart >= 0, ("gv_raid5_offset: stripestart < 0")); stripeoff %= p->stripesize; /* The offset of the request on this subdisk. */ *real_off = stripestart + stripeoff; stripeend = stripestart + p->stripesize; len_left = stripeend - *real_off; KASSERT(len_left >= 0, ("gv_raid5_offset: len_left < 0")); *real_len = (bcount <= len_left) ? bcount : len_left; if (sdno != NULL) *sdno = sd; if (psdno != NULL) *psdno = psd; return (0); } static struct bio * gv_raid5_clone_bio(struct bio *bp, struct gv_sd *s, struct gv_raid5_packet *wp, caddr_t addr, int use_wp) { struct bio *cbp; cbp = g_clone_bio(bp); if (cbp == NULL) return (NULL); if (addr == NULL) { cbp->bio_data = g_malloc(wp->length, M_WAITOK | M_ZERO); cbp->bio_cflags |= GV_BIO_MALLOC; } else cbp->bio_data = addr; cbp->bio_offset = wp->lockbase + s->drive_offset; cbp->bio_length = wp->length; cbp->bio_done = gv_done; cbp->bio_caller1 = s; if (use_wp) cbp->bio_caller2 = wp; return (cbp); }