diff options
Diffstat (limited to 'sys/geom/multipath/g_multipath.c')
-rw-r--r-- | sys/geom/multipath/g_multipath.c | 768 |
1 files changed, 768 insertions, 0 deletions
diff --git a/sys/geom/multipath/g_multipath.c b/sys/geom/multipath/g_multipath.c new file mode 100644 index 0000000..0398628 --- /dev/null +++ b/sys/geom/multipath/g_multipath.c @@ -0,0 +1,768 @@ +/*- + * Copyright (c) 2006-2007 Matthew Jacob <mjacob@FreeBSD.org> + * 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 <pjd@FreeBSD.org> for all of the + * fine geom examples, and by Poul Henning Kamp <phk@FreeBSD.org> for GEOM + * itself, all of which is most gratefully acknowledged. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/bio.h> +#include <sys/sysctl.h> +#include <sys/kthread.h> +#include <sys/malloc.h> +#include <geom/geom.h> +#include <geom/multipath/g_multipath.h> + + +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 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) { + printf("GEOM_MULTIPATH: out of providers for %s\n", + sc->sc_name); + 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); + kthread_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); + if (sc == NULL) { + goto fail; + } + + 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 void +g_multipath_init(struct g_class *mp) +{ + bioq_init(&gmtbq); + mtx_init(&gmtbq_mtx, "gmtbq", NULL, MTX_DEF); + if (kthread_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_create(struct gctl_req *req, struct g_class *mp) +{ + struct g_geom *gp; + struct g_provider *pp0, *pp1; + struct g_multipath_metadata md; + const char *name, *mpname, *uuid; + static const char devpf[6] = "/dev/"; + int *nargs, error; + + g_topology_assert(); + + mpname = gctl_get_asciiparam(req, "arg0"); + if (mpname == NULL) { + gctl_error(req, "No 'arg0' argument"); + return; + } + + nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs)); + if (nargs == NULL) { + gctl_error(req, "No 'nargs' argument"); + return; + } + if (*nargs != 4) { + gctl_error(req, "missing device or uuid arguments"); + 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; + } + pp0 = g_provider_by_name(name); + if (pp0 == NULL) { + gctl_error(req, "Provider %s is invalid", name); + return; + } + + name = gctl_get_asciiparam(req, "arg2"); + if (name == NULL) { + gctl_error(req, "No 'arg2' argument"); + return; + } + if (strncmp(name, devpf, 5) == 0) { + name += 5; + } + pp1 = g_provider_by_name(name); + if (pp1 == NULL) { + gctl_error(req, "Provider %s is invalid", name); + return; + } + + uuid = gctl_get_asciiparam(req, "arg3"); + if (uuid == NULL) { + gctl_error(req, "No uuid argument"); + return; + } + if (strlen(uuid) != 36) { + gctl_error(req, "Malformed uuid argument"); + return; + } + + /* + * Check to make sure parameters from the two providers are the same + */ + if (pp0 == pp1) { + gctl_error(req, "providers %s and %s are the same", + pp0->name, pp1->name); + return; + } + if (pp0->mediasize != pp1->mediasize) { + gctl_error(req, "Provider %s is %jd; Provider %s is %jd", + pp0->name, (intmax_t) pp0->mediasize, + pp1->name, (intmax_t) pp1->mediasize); + return; + } + if (pp0->sectorsize != pp1->sectorsize) { + gctl_error(req, "Provider %s has sectorsize %u; Provider %s " + "has sectorsize %u", pp0->name, pp0->sectorsize, + pp1->name, pp1->sectorsize); + return; + } + + /* + * cons up enough of a metadata structure to use. + */ + memset(&md, 0, sizeof(md)); + md.md_size = pp0->mediasize; + md.md_sectorsize = pp0->sectorsize; + strncpy(md.md_name, mpname, sizeof (md.md_name)); + strncpy(md.md_uuid, uuid, sizeof (md.md_uuid)); + + gp = g_multipath_create(mp, &md); + if (gp == NULL) { + return; + } + error = g_multipath_add_disk(gp, pp0); + if (error) { + g_multipath_destroy(gp); + return; + } + error = g_multipath_add_disk(gp, pp1); + if (error) { + g_multipath_destroy(gp); + return; + } +} + +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_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, "create") == 0) { + g_multipath_ctl_create(req, mp); + } else if (strcmp(verb, "destroy") == 0) { + g_multipath_ctl_destroy(req, mp); + } else { + gctl_error(req, "Unknown verb %s", verb); + } +} +DECLARE_GEOM_CLASS(g_multipath_class, g_multipath); |