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/*-
* Copyright (c) 2003 Poul-Henning Kamp
* 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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.
*
* $FreeBSD$
*
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/bio.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/libkern.h>
#include <sys/endian.h>
#include <sys/md5.h>
#include <sys/errno.h>
#include <geom/geom.h>
#define MIRROR_MAGIC "GEOM::MIRROR"
struct g_mirror_softc {
off_t mediasize;
u_int sectorsize;
u_char magic[16];
};
static int
g_mirror_add(struct g_geom *gp, struct g_provider *pp)
{
struct g_consumer *cp;
g_trace(G_T_TOPOLOGY, "g_mirror_add(%s, %s)", gp->name, pp->name);
g_topology_assert();
cp = g_new_consumer(gp);
g_attach(cp, pp);
return (0);
}
static void
g_mirror_orphan(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_provider *pp;
g_topology_assert();
gp = cp->geom;
g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
g_detach(cp);
g_destroy_consumer(cp);
if (!LIST_EMPTY(&gp->consumer))
return;
LIST_FOREACH(pp, &gp->provider, provider)
g_orphan_provider(pp, ENXIO);
g_free(gp->softc);
gp->flags |= G_GEOM_WITHER;
}
static void
g_mirror_done(struct bio *bp)
{
struct g_geom *gp;
struct g_mirror_softc *sc;
struct g_consumer *cp;
gp = bp->bio_to->geom;
sc = gp->softc;
cp = LIST_NEXT(bp->bio_from, consumer);
if (cp == NULL)
g_std_done(bp);
else
g_io_request(bp, cp);
}
static void
g_mirror_start(struct bio *bp)
{
struct g_geom *gp;
struct bio *bp2;
struct g_mirror_softc *sc;
gp = bp->bio_to->geom;
sc = gp->softc;
switch(bp->bio_cmd) {
case BIO_READ:
bp2 = g_clone_bio(bp);
bp2->bio_offset += sc->sectorsize;
bp2->bio_done = g_std_done;
g_io_request(bp2, LIST_FIRST(&gp->consumer));
return;
case BIO_WRITE:
case BIO_DELETE:
bp2 = g_clone_bio(bp);
bp2->bio_offset += sc->sectorsize;
bp2->bio_done = g_mirror_done;
g_io_request(bp2, LIST_FIRST(&gp->consumer));
return;
default:
g_io_deliver(bp, EOPNOTSUPP);
return;
}
}
static int
g_mirror_access(struct g_provider *pp, int dr, int dw, int de)
{
struct g_geom *gp;
struct g_consumer *cp1, *cp2;
int error;
de += dr;
de += dw;
gp = pp->geom;
error = ENXIO;
LIST_FOREACH(cp1, &gp->consumer, consumer) {
error = g_access_rel(cp1, dr, dw, de);
if (error) {
LIST_FOREACH(cp2, &gp->consumer, consumer) {
if (cp2 == cp1)
break;
g_access_rel(cp2, -dr, -dw, -de);
}
return (error);
}
}
return (error);
}
static struct g_geom *
g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
struct g_geom *gp, *gp2;
struct g_provider *pp2;
struct g_consumer *cp;
struct g_mirror_softc *sc;
int error;
u_int sectorsize;
u_char *buf;
g_trace(G_T_TOPOLOGY, "mirror_taste(%s, %s)", mp->name, pp->name);
g_topology_assert();
gp = g_new_geomf(mp, "%s.mirror", pp->name);
gp->start = g_mirror_start;
gp->spoiled = g_mirror_orphan;
gp->orphan = g_mirror_orphan;
gp->access= g_mirror_access;
cp = g_new_consumer(gp);
g_attach(cp, pp);
error = g_access_rel(cp, 1, 0, 0);
if (error) {
g_detach(cp);
g_destroy_consumer(cp);
g_destroy_geom(gp);
return(NULL);
}
g_topology_unlock();
while (1) {
sectorsize = cp->provider->sectorsize;
buf = g_read_data(cp, 0, sectorsize, &error);
if (buf == NULL || error != 0)
break;
if (memcmp(buf, MIRROR_MAGIC, strlen(MIRROR_MAGIC)))
break;
LIST_FOREACH(gp2, &mp->geom, geom) {
sc = gp2->softc;
if (sc == NULL)
continue;
if (memcmp(buf + 16, sc->magic, sizeof sc->magic))
continue;
break;
}
/* We found somebody else */
if (gp2 != NULL) {
g_topology_lock();
g_mirror_add(gp2, pp);
g_topology_unlock();
break;
}
gp->softc = g_malloc(sizeof(struct g_mirror_softc), M_WAITOK);
sc = gp->softc;
memcpy(sc->magic, buf + 16, sizeof sc->magic);
g_topology_lock();
pp2 = g_new_providerf(gp, "%s", gp->name);
pp2->mediasize = sc->mediasize = pp->mediasize - pp->sectorsize;
pp2->sectorsize = sc->sectorsize = pp->sectorsize;
g_error_provider(pp2, 0);
g_topology_unlock();
break;
}
g_topology_lock();
if (buf != NULL)
g_free(buf);
g_access_rel(cp, -1, 0, 0);
if (gp->softc != NULL)
return (gp);
g_detach(cp);
g_destroy_consumer(cp);
g_destroy_geom(gp);
return (NULL);
}
#define MIRROR_CLASS_NAME "MIRROR"
static struct g_class g_mirror_class = {
.name = MIRROR_CLASS_NAME,
.taste = g_mirror_taste,
G_CLASS_INITIALIZER
};
DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
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