/*- * Copyright (c) 2006-2007 Matthew Jacob * 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 AUTHORS 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 AUTHORS 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. */ /* * Based upon work by Pawel Jakub Dawidek for all of the * fine geom examples, and by Poul Henning Kamp for GEOM * itself, all of which is most gratefully acknowledged. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include FEATURE(geom_multipath, "GEOM multipath support"); SYSCTL_DECL(_kern_geom); SYSCTL_NODE(_kern_geom, OID_AUTO, multipath, CTLFLAG_RW, 0, "GEOM_MULTIPATH tunables"); static u_int g_multipath_debug = 0; SYSCTL_UINT(_kern_geom_multipath, OID_AUTO, debug, CTLFLAG_RW, &g_multipath_debug, 0, "Debug level"); static enum { GKT_NIL, GKT_RUN, GKT_DIE } g_multipath_kt_state; static struct bio_queue_head gmtbq; static struct mtx gmtbq_mtx; static void g_multipath_orphan(struct g_consumer *); static void g_multipath_start(struct bio *); static void g_multipath_done(struct bio *); static void g_multipath_done_error(struct bio *); static void g_multipath_kt(void *); static int g_multipath_destroy(struct g_geom *); static int g_multipath_destroy_geom(struct gctl_req *, struct g_class *, struct g_geom *); static struct g_geom *g_multipath_find_geom(struct g_class *, const char *); static int g_multipath_rotate(struct g_geom *); static g_taste_t g_multipath_taste; static g_ctl_req_t g_multipath_config; static g_init_t g_multipath_init; static g_fini_t g_multipath_fini; struct g_class g_multipath_class = { .name = G_MULTIPATH_CLASS_NAME, .version = G_VERSION, .ctlreq = g_multipath_config, .taste = g_multipath_taste, .destroy_geom = g_multipath_destroy_geom, .init = g_multipath_init, .fini = g_multipath_fini }; #define MP_BAD 0x1 #define MP_POSTED 0x2 static void g_mpd(void *arg, int flags __unused) { struct g_consumer *cp; g_topology_assert(); cp = arg; if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0) g_access(cp, -cp->acr, -cp->acw, -cp->ace); if (cp->provider) { printf("GEOM_MULTIPATH: %s removed from %s\n", cp->provider->name, cp->geom->name); g_detach(cp); } g_destroy_consumer(cp); } static void g_multipath_orphan(struct g_consumer *cp) { if ((cp->index & MP_POSTED) == 0) { cp->index |= MP_POSTED; printf("GEOM_MULTIPATH: %s orphaned in %s\n", cp->provider->name, cp->geom->name); g_mpd(cp, 0); } } static void g_multipath_start(struct bio *bp) { struct g_multipath_softc *sc; struct g_geom *gp; struct g_consumer *cp; struct bio *cbp; gp = bp->bio_to->geom; sc = gp->softc; KASSERT(sc != NULL, ("NULL sc")); cp = sc->cp_active; if (cp == NULL) { g_io_deliver(bp, ENXIO); return; } cbp = g_clone_bio(bp); if (cbp == NULL) { g_io_deliver(bp, ENOMEM); return; } cbp->bio_done = g_multipath_done; g_io_request(cbp, cp); } static void g_multipath_done(struct bio *bp) { if (bp->bio_error == ENXIO || bp->bio_error == EIO) { mtx_lock(&gmtbq_mtx); bioq_insert_tail(&gmtbq, bp); wakeup(&g_multipath_kt_state); mtx_unlock(&gmtbq_mtx); } else { g_std_done(bp); } } static void g_multipath_done_error(struct bio *bp) { struct bio *pbp; struct g_geom *gp; struct g_multipath_softc *sc; struct g_consumer *cp; struct g_provider *pp; /* * If we had a failure, we have to check first to see * whether the consumer it failed on was the currently * active consumer (i.e., this is the first in perhaps * a number of failures). If so, we then switch consumers * to the next available consumer. */ g_topology_lock(); pbp = bp->bio_parent; gp = pbp->bio_to->geom; sc = gp->softc; cp = bp->bio_from; pp = cp->provider; cp->index |= MP_BAD; if (cp->nend == cp->nstart && pp->nend == pp->nstart) { cp->index |= MP_POSTED; g_post_event(g_mpd, cp, M_NOWAIT, NULL); } if (cp == sc->cp_active) { struct g_consumer *lcp; printf("GEOM_MULTIPATH: %s failed in %s\n", pp->name, sc->sc_name); sc->cp_active = NULL; LIST_FOREACH(lcp, &gp->consumer, consumer) { if ((lcp->index & MP_BAD) == 0) { sc->cp_active = lcp; break; } } if (sc->cp_active == NULL || sc->cp_active->provider == NULL) { printf("GEOM_MULTIPATH: out of providers for %s\n", sc->sc_name); g_topology_unlock(); return; } else { printf("GEOM_MULTIPATH: %s now active path in %s\n", sc->cp_active->provider->name, sc->sc_name); } } g_topology_unlock(); /* * If we can fruitfully restart the I/O, do so. */ if (sc->cp_active) { g_destroy_bio(bp); pbp->bio_children--; g_multipath_start(pbp); } else { g_std_done(bp); } } static void g_multipath_kt(void *arg) { g_multipath_kt_state = GKT_RUN; mtx_lock(&gmtbq_mtx); while (g_multipath_kt_state == GKT_RUN) { for (;;) { struct bio *bp; bp = bioq_takefirst(&gmtbq); if (bp == NULL) break; mtx_unlock(&gmtbq_mtx); g_multipath_done_error(bp); mtx_lock(&gmtbq_mtx); } msleep(&g_multipath_kt_state, &gmtbq_mtx, PRIBIO, "gkt:wait", hz / 10); } mtx_unlock(&gmtbq_mtx); wakeup(&g_multipath_kt_state); kproc_exit(0); } static int g_multipath_access(struct g_provider *pp, int dr, int dw, int de) { struct g_geom *gp; struct g_consumer *cp, *badcp = NULL; int error; gp = pp->geom; LIST_FOREACH(cp, &gp->consumer, consumer) { error = g_access(cp, dr, dw, de); if (error) { badcp = cp; goto fail; } } return (0); fail: LIST_FOREACH(cp, &gp->consumer, consumer) { if (cp == badcp) break; (void) g_access(cp, -dr, -dw, -de); } return (error); } static struct g_geom * g_multipath_create(struct g_class *mp, struct g_multipath_metadata *md) { struct g_multipath_softc *sc; struct g_geom *gp; struct g_provider *pp; g_topology_assert(); LIST_FOREACH(gp, &mp->geom, geom) { if (strcmp(gp->name, md->md_name) == 0) { printf("GEOM_MULTIPATH: name %s already exists\n", md->md_name); return (NULL); } } gp = g_new_geomf(mp, md->md_name); if (gp == NULL) goto fail; sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO); gp->softc = sc; gp->start = g_multipath_start; gp->orphan = g_multipath_orphan; gp->access = g_multipath_access; memcpy(sc->sc_uuid, md->md_uuid, sizeof (sc->sc_uuid)); memcpy(sc->sc_name, md->md_name, sizeof (sc->sc_name)); pp = g_new_providerf(gp, "multipath/%s", md->md_name); if (pp == NULL) goto fail; /* limit the provider to not have it stomp on metadata */ pp->mediasize = md->md_size - md->md_sectorsize; pp->sectorsize = md->md_sectorsize; sc->pp = pp; g_error_provider(pp, 0); return (gp); fail: if (gp != NULL) { if (gp->softc != NULL) g_free(gp->softc); g_destroy_geom(gp); } return (NULL); } static int g_multipath_add_disk(struct g_geom *gp, struct g_provider *pp) { struct g_multipath_softc *sc; struct g_consumer *cp, *nxtcp; int error; g_topology_assert(); sc = gp->softc; KASSERT(sc, ("no softc")); /* * Make sure that the passed provider isn't already attached */ LIST_FOREACH(cp, &gp->consumer, consumer) { if (cp->provider == pp) break; } if (cp) { printf("GEOM_MULTIPATH: provider %s already attached to %s\n", pp->name, gp->name); return (EEXIST); } nxtcp = LIST_FIRST(&gp->consumer); cp = g_new_consumer(gp); if (cp == NULL) return (ENOMEM); error = g_attach(cp, pp); if (error != 0) { printf("GEOM_MULTIPATH: cannot attach %s to %s", pp->name, sc->sc_name); g_destroy_consumer(cp); return (error); } cp->private = sc; cp->index = 0; /* * Set access permissions on new consumer to match other consumers */ if (nxtcp && (nxtcp->acr + nxtcp->acw + nxtcp->ace)) { error = g_access(cp, nxtcp->acr, nxtcp->acw, nxtcp->ace); if (error) { printf("GEOM_MULTIPATH: cannot set access in " "attaching %s to %s/%s (%d)\n", pp->name, sc->sc_name, sc->sc_uuid, error); g_detach(cp); g_destroy_consumer(cp); return (error); } } printf("GEOM_MULTIPATH: adding %s to %s/%s\n", pp->name, sc->sc_name, sc->sc_uuid); if (sc->cp_active == NULL) { sc->cp_active = cp; printf("GEOM_MULTIPATH: %s now active path in %s\n", pp->name, sc->sc_name); } return (0); } static int g_multipath_destroy(struct g_geom *gp) { struct g_provider *pp; g_topology_assert(); if (gp->softc == NULL) return (ENXIO); pp = LIST_FIRST(&gp->provider); if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) return (EBUSY); printf("GEOM_MULTIPATH: destroying %s\n", gp->name); g_free(gp->softc); gp->softc = NULL; g_wither_geom(gp, ENXIO); return (0); } static int g_multipath_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp) { return (g_multipath_destroy(gp)); } static int g_multipath_rotate(struct g_geom *gp) { struct g_consumer *lcp; struct g_multipath_softc *sc = gp->softc; g_topology_assert(); if (sc == NULL) return (ENXIO); LIST_FOREACH(lcp, &gp->consumer, consumer) { if ((lcp->index & MP_BAD) == 0) { if (sc->cp_active != lcp) { break; } } } if (lcp) { sc->cp_active = lcp; printf("GEOM_MULTIPATH: %s now active path in %s\n", lcp->provider->name, sc->sc_name); } return (0); } static void g_multipath_init(struct g_class *mp) { bioq_init(&gmtbq); mtx_init(&gmtbq_mtx, "gmtbq", NULL, MTX_DEF); if (kproc_create(g_multipath_kt, mp, NULL, 0, 0, "g_mp_kt") == 0) g_multipath_kt_state = GKT_RUN; } static void g_multipath_fini(struct g_class *mp) { if (g_multipath_kt_state == GKT_RUN) { mtx_lock(&gmtbq_mtx); g_multipath_kt_state = GKT_DIE; wakeup(&g_multipath_kt_state); msleep(&g_multipath_kt_state, &gmtbq_mtx, PRIBIO, "gmp:fini", 0); mtx_unlock(&gmtbq_mtx); } } static int g_multipath_read_metadata(struct g_consumer *cp, struct g_multipath_metadata *md) { struct g_provider *pp; u_char *buf; int error; g_topology_assert(); error = g_access(cp, 1, 0, 0); if (error != 0) return (error); pp = cp->provider; g_topology_unlock(); buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize, &error); g_topology_lock(); g_access(cp, -1, 0, 0); if (buf == NULL) return (error); multipath_metadata_decode(buf, md); g_free(buf); return (0); } static struct g_geom * g_multipath_taste(struct g_class *mp, struct g_provider *pp, int flags __unused) { struct g_multipath_metadata md; struct g_multipath_softc *sc; struct g_consumer *cp; struct g_geom *gp, *gp1; int error, isnew; g_topology_assert(); gp = g_new_geomf(mp, "multipath:taste"); gp->start = g_multipath_start; gp->access = g_multipath_access; gp->orphan = g_multipath_orphan; cp = g_new_consumer(gp); g_attach(cp, pp); error = g_multipath_read_metadata(cp, &md); g_detach(cp); g_destroy_consumer(cp); g_destroy_geom(gp); if (error != 0) return (NULL); gp = NULL; if (strcmp(md.md_magic, G_MULTIPATH_MAGIC) != 0) { if (g_multipath_debug) printf("%s is not MULTIPATH\n", pp->name); return (NULL); } if (md.md_version != G_MULTIPATH_VERSION) { printf("%s has version %d multipath id- this module is version " " %d: rejecting\n", pp->name, md.md_version, G_MULTIPATH_VERSION); return (NULL); } if (g_multipath_debug) printf("MULTIPATH: %s/%s\n", md.md_name, md.md_uuid); /* * Let's check if such a device already is present. We check against * uuid alone first because that's the true distinguishor. If that * passes, then we check for name conflicts. If there are conflicts, * modify the name. * * The whole purpose of this is to solve the problem that people don't * pick good unique names, but good unique names (like uuids) are a * pain to use. So, we allow people to build GEOMs with friendly names * and uuids, and modify the names in case there's a collision. */ sc = NULL; LIST_FOREACH(gp, &mp->geom, geom) { sc = gp->softc; if (sc == NULL) continue; if (strncmp(md.md_uuid, sc->sc_uuid, sizeof(md.md_uuid)) == 0) break; } LIST_FOREACH(gp1, &mp->geom, geom) { if (gp1 == gp) continue; sc = gp1->softc; if (sc == NULL) continue; if (strncmp(md.md_name, sc->sc_name, sizeof(md.md_name)) == 0) break; } /* * If gp is NULL, we had no extant MULTIPATH geom with this uuid. * * If gp1 is *not* NULL, that means we have a MULTIPATH geom extant * with the same name (but a different UUID). * * If gp is NULL, then modify the name with a random number and * complain, but allow the creation of the geom to continue. * * If gp is *not* NULL, just use the geom's name as we're attaching * this disk to the (previously generated) name. */ if (gp1) { sc = gp1->softc; if (gp == NULL) { char buf[16]; u_long rand = random(); snprintf(buf, sizeof (buf), "%s-%lu", md.md_name, rand); printf("GEOM_MULTIPATH: geom %s/%s exists already\n", sc->sc_name, sc->sc_uuid); printf("GEOM_MULTIPATH: %s will be (temporarily) %s\n", md.md_uuid, buf); strlcpy(md.md_name, buf, sizeof(md.md_name)); } else { strlcpy(md.md_name, sc->sc_name, sizeof(md.md_name)); } } if (gp == NULL) { gp = g_multipath_create(mp, &md); if (gp == NULL) { printf("GEOM_MULTIPATH: cannot create geom %s/%s\n", md.md_name, md.md_uuid); return (NULL); } isnew = 1; } else { isnew = 0; } sc = gp->softc; KASSERT(sc != NULL, ("sc is NULL")); error = g_multipath_add_disk(gp, pp); if (error != 0) { if (isnew) g_multipath_destroy(gp); return (NULL); } return (gp); } static void g_multipath_ctl_add(struct gctl_req *req, struct g_class *mp) { struct g_geom *gp; struct g_consumer *cp; struct g_provider *pp, *pp0; const char *name, *mpname; static const char devpf[6] = "/dev/"; g_topology_assert(); mpname = gctl_get_asciiparam(req, "arg0"); if (mpname == NULL) { gctl_error(req, "No 'arg0' argument"); return; } gp = g_multipath_find_geom(mp, mpname); if (gp == NULL) { gctl_error(req, "Device %s is invalid", mpname); return; } name = gctl_get_asciiparam(req, "arg1"); if (name == NULL) { gctl_error(req, "No 'arg1' argument"); return; } if (strncmp(name, devpf, 5) == 0) name += 5; pp = g_provider_by_name(name); if (pp == NULL) { gctl_error(req, "Provider %s is invalid", name); return; } /* * Check to make sure parameters match, if we already have one. */ cp = LIST_FIRST(&gp->consumer); if (cp) { pp0 = cp->provider; } else { pp0 = NULL; } if (pp0) { if (pp0 == pp) { gctl_error(req, "providers %s and %s are the same", pp0->name, pp->name); return; } if (pp0->mediasize != pp->mediasize) { gctl_error(req, "Provider %s is %jd; Provider %s is %jd", pp0->name, (intmax_t) pp0->mediasize, pp->name, (intmax_t) pp->mediasize); return; } if (pp0->sectorsize != pp->sectorsize) { gctl_error(req, "Provider %s has sectorsize %u; Provider %s " "has sectorsize %u", pp0->name, pp0->sectorsize, pp->name, pp->sectorsize); return; } } /* * Now add.... */ (void) g_multipath_add_disk(gp, pp); } static struct g_geom * g_multipath_find_geom(struct g_class *mp, const char *name) { struct g_geom *gp; LIST_FOREACH(gp, &mp->geom, geom) { if (strcmp(gp->name, name) == 0) { return (gp); } } return (NULL); } static void g_multipath_ctl_destroy(struct gctl_req *req, struct g_class *mp) { struct g_geom *gp; const char *name; int error; g_topology_assert(); name = gctl_get_asciiparam(req, "arg0"); if (name == NULL) { gctl_error(req, "No 'arg0' argument"); return; } gp = g_multipath_find_geom(mp, name); if (gp == NULL) { gctl_error(req, "Device %s is invalid", name); return; } error = g_multipath_destroy(gp); if (error != 0) { gctl_error(req, "failed to destroy %s (err=%d)", name, error); } } static void g_multipath_ctl_rotate(struct gctl_req *req, struct g_class *mp) { struct g_geom *gp; const char *name; int error; g_topology_assert(); name = gctl_get_asciiparam(req, "arg0"); if (name == NULL) { gctl_error(req, "No 'arg0' argument"); return; } gp = g_multipath_find_geom(mp, name); if (gp == NULL) { gctl_error(req, "Device %s is invalid", name); return; } error = g_multipath_rotate(gp); if (error != 0) { gctl_error(req, "failed to rotate %s (err=%d)", name, error); } } static void g_multipath_ctl_getactive(struct gctl_req *req, struct g_class *mp) { struct sbuf *sb; struct g_geom *gp; struct g_multipath_softc *sc; const char *name; sb = sbuf_new_auto(); g_topology_assert(); name = gctl_get_asciiparam(req, "arg0"); if (name == NULL) { gctl_error(req, "No 'arg0' argument"); return; } gp = g_multipath_find_geom(mp, name); if (gp == NULL) { gctl_error(req, "Device %s is invalid", name); return; } sc = gp->softc; if (sc->cp_active && sc->cp_active->provider) { sbuf_printf(sb, "%s\n", sc->cp_active->provider->name); } else { sbuf_printf(sb, "none\n"); } sbuf_finish(sb); gctl_set_param_err(req, "output", sbuf_data(sb), sbuf_len(sb) + 1); sbuf_delete(sb); } static void g_multipath_config(struct gctl_req *req, struct g_class *mp, const char *verb) { uint32_t *version; g_topology_assert(); version = gctl_get_paraml(req, "version", sizeof(*version)); if (version == NULL) { gctl_error(req, "No 'version' argument"); } else if (*version != G_MULTIPATH_VERSION) { gctl_error(req, "Userland and kernel parts are out of sync"); } else if (strcmp(verb, "add") == 0) { g_multipath_ctl_add(req, mp); } else if (strcmp(verb, "destroy") == 0) { g_multipath_ctl_destroy(req, mp); } else if (strcmp(verb, "rotate") == 0) { g_multipath_ctl_rotate(req, mp); } else if (strcmp(verb, "getactive") == 0) { g_multipath_ctl_getactive(req, mp); } else { gctl_error(req, "Unknown verb %s", verb); } } DECLARE_GEOM_CLASS(g_multipath_class, g_multipath);