freebsd-dev/sys/geom/multipath/g_multipath.c
Matt Jacob 87e7f7be89 Yet another potential dereference of a dead provider.
Sponsored by:   Panasas
MFC after:	1 week
2010-05-14 21:27:39 +00:00

793 lines
19 KiB
C

/*-
* 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 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);