freebsd-dev/sys/geom/vinum/geom_vinum_volume.c
Lukas Ertl d8688e1117 Correctly calculate what to do and how to retry a request to a plex when
the previous one failed and there are more than one plex in the volume.

This could have led to a flood of error messages on the console and
probably a deadlock in certain situations.
2005-02-23 14:59:14 +00:00

445 lines
10 KiB
C

/*-
* Copyright (c) 2004 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bio.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <geom/geom.h>
#include <geom/vinum/geom_vinum_var.h>
#include <geom/vinum/geom_vinum.h>
static void gv_vol_completed_request(struct gv_volume *, struct bio *);
static void gv_vol_normal_request(struct gv_volume *, struct bio *);
static void
gv_volume_orphan(struct g_consumer *cp)
{
struct g_geom *gp;
struct gv_volume *v;
int error;
g_topology_assert();
gp = cp->geom;
g_trace(G_T_TOPOLOGY, "gv_volume_orphan(%s)", gp->name);
if (cp->acr != 0 || cp->acw != 0 || cp->ace != 0)
g_access(cp, -cp->acr, -cp->acw, -cp->ace);
error = cp->provider->error;
if (error == 0)
error = ENXIO;
g_detach(cp);
g_destroy_consumer(cp);
if (!LIST_EMPTY(&gp->consumer))
return;
v = gp->softc;
if (v != NULL) {
gv_kill_vol_thread(v);
v->geom = NULL;
}
gp->softc = NULL;
g_wither_geom(gp, error);
}
/* We end up here after the requests to our plexes are done. */
static void
gv_volume_done(struct bio *bp)
{
struct gv_volume *v;
struct gv_bioq *bq;
v = bp->bio_from->geom->softc;
bp->bio_cflags |= GV_BIO_DONE;
bq = g_malloc(sizeof(*bq), M_NOWAIT | M_ZERO);
bq->bp = bp;
mtx_lock(&v->bqueue_mtx);
TAILQ_INSERT_TAIL(&v->bqueue, bq, queue);
wakeup(v);
mtx_unlock(&v->bqueue_mtx);
}
static void
gv_volume_start(struct bio *bp)
{
struct gv_volume *v;
struct gv_bioq *bq;
switch(bp->bio_cmd) {
case BIO_READ:
case BIO_WRITE:
case BIO_DELETE:
break;
case BIO_GETATTR:
default:
g_io_deliver(bp, EOPNOTSUPP);
return;
}
v = bp->bio_to->geom->softc;
if (v->state != GV_VOL_UP) {
g_io_deliver(bp, ENXIO);
return;
}
bq = g_malloc(sizeof(*bq), M_NOWAIT | M_ZERO);
bq->bp = bp;
mtx_lock(&v->bqueue_mtx);
TAILQ_INSERT_TAIL(&v->bqueue, bq, queue);
wakeup(v);
mtx_unlock(&v->bqueue_mtx);
}
static void
gv_vol_worker(void *arg)
{
struct bio *bp;
struct gv_volume *v;
struct gv_bioq *bq;
v = arg;
KASSERT(v != NULL, ("NULL v"));
mtx_lock(&v->bqueue_mtx);
for (;;) {
/* We were signaled to exit. */
if (v->flags & GV_VOL_THREAD_DIE)
break;
/* Take the first BIO from our queue. */
bq = TAILQ_FIRST(&v->bqueue);
if (bq == NULL) {
msleep(v, &v->bqueue_mtx, PRIBIO, "-", hz/10);
continue;
}
TAILQ_REMOVE(&v->bqueue, bq, queue);
mtx_unlock(&v->bqueue_mtx);
bp = bq->bp;
g_free(bq);
if (bp->bio_cflags & GV_BIO_DONE)
gv_vol_completed_request(v, bp);
else
gv_vol_normal_request(v, bp);
mtx_lock(&v->bqueue_mtx);
}
mtx_unlock(&v->bqueue_mtx);
v->flags |= GV_VOL_THREAD_DEAD;
wakeup(v);
kthread_exit(ENXIO);
}
static void
gv_vol_completed_request(struct gv_volume *v, struct bio *bp)
{
struct bio *pbp;
struct g_geom *gp;
struct g_consumer *cp, *cp2;
struct gv_bioq *bq;
pbp = bp->bio_parent;
if (pbp->bio_error == 0)
pbp->bio_error = bp->bio_error;
switch (pbp->bio_cmd) {
case BIO_READ:
if (bp->bio_error == 0)
break;
if (pbp->bio_cflags & GV_BIO_RETRY)
break;
/* Check if we have another plex left. */
cp = bp->bio_from;
gp = cp->geom;
cp2 = LIST_NEXT(cp, consumer);
if (cp2 == NULL)
break;
if (LIST_NEXT(cp2, consumer) == NULL)
pbp->bio_cflags |= GV_BIO_RETRY;
g_destroy_bio(bp);
pbp->bio_children--;
bq = g_malloc(sizeof(*bq), M_WAITOK | M_ZERO);
bq->bp = pbp;
mtx_lock(&v->bqueue_mtx);
TAILQ_INSERT_TAIL(&v->bqueue, bq, queue);
mtx_unlock(&v->bqueue_mtx);
return;
case BIO_WRITE:
case BIO_DELETE:
/* Remember if this write request succeeded. */
if (bp->bio_error == 0)
pbp->bio_cflags |= GV_BIO_SUCCEED;
break;
}
/* When the original request is finished, we deliver it. */
pbp->bio_inbed++;
if (pbp->bio_inbed == pbp->bio_children) {
if (pbp->bio_cflags & GV_BIO_SUCCEED)
pbp->bio_error = 0;
pbp->bio_completed = bp->bio_length;
g_io_deliver(pbp, pbp->bio_error);
}
g_destroy_bio(bp);
}
static void
gv_vol_normal_request(struct gv_volume *v, struct bio *bp)
{
struct g_geom *gp;
struct gv_plex *p;
struct bio *cbp, *pbp;
gp = v->geom;
switch (bp->bio_cmd) {
case BIO_READ:
cbp = g_clone_bio(bp);
if (cbp == NULL) {
g_io_deliver(bp, ENOMEM);
return;
}
cbp->bio_done = gv_volume_done;
/*
* Try to find a good plex where we can send the request to.
* The plex either has to be up, or it's a degraded RAID5 plex.
*/
p = NULL;
LIST_FOREACH(p, &v->plexes, in_volume) {
if ((p->state > GV_PLEX_DEGRADED) ||
(p->state >= GV_PLEX_DEGRADED &&
p->org == GV_PLEX_RAID5))
break;
}
if (p == NULL) {
g_destroy_bio(cbp);
bp->bio_children--;
g_io_deliver(bp, ENXIO);
return;
}
g_io_request(cbp, p->consumer);
break;
case BIO_WRITE:
case BIO_DELETE:
LIST_FOREACH(p, &v->plexes, in_volume) {
if (p->state < GV_PLEX_DEGRADED)
continue;
cbp = g_clone_bio(bp);
if (cbp == NULL) /* XXX */
g_io_deliver(bp, ENOMEM);
cbp->bio_done = gv_volume_done;
cbp->bio_caller2 = p->consumer;
if (bp->bio_driver1 == NULL) {
bp->bio_driver1 = cbp;
} else {
pbp = bp->bio_driver1;
while (pbp->bio_caller1 != NULL)
pbp = pbp->bio_caller1;
pbp->bio_caller1 = cbp;
}
}
/* Fire off all sub-requests. */
pbp = bp->bio_driver1;
while (pbp != NULL) {
g_io_request(pbp, pbp->bio_caller2);
pbp = pbp->bio_caller1;
}
break;
}
}
static int
gv_volume_access(struct g_provider *pp, int dr, int dw, int de)
{
struct g_geom *gp;
struct g_consumer *cp, *cp2;
int error;
gp = pp->geom;
error = ENXIO;
LIST_FOREACH(cp, &gp->consumer, consumer) {
error = g_access(cp, dr, dw, de);
if (error) {
LIST_FOREACH(cp2, &gp->consumer, consumer) {
if (cp == cp2)
break;
g_access(cp2, -dr, -dw, -de);
}
return (error);
}
}
return (error);
}
static struct g_geom *
gv_volume_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
struct g_geom *gp;
struct g_provider *pp2;
struct g_consumer *cp, *ocp;
struct gv_softc *sc;
struct gv_volume *v;
struct gv_plex *p;
int error, first;
g_trace(G_T_TOPOLOGY, "gv_volume_taste(%s, %s)", mp->name, pp->name);
g_topology_assert();
/* First, find the VINUM class and its associated geom. */
gp = find_vinum_geom();
if (gp == NULL)
return (NULL);
sc = gp->softc;
KASSERT(sc != NULL, ("gv_volume_taste: NULL sc"));
gp = pp->geom;
/* We only want to attach to plexes. */
if (strcmp(gp->class->name, "VINUMPLEX"))
return (NULL);
first = 0;
p = gp->softc;
/* Let's see if the volume this plex wants is already configured. */
v = gv_find_vol(sc, p->volume);
if (v == NULL)
return (NULL);
if (v->geom == NULL) {
gp = g_new_geomf(mp, "%s", p->volume);
gp->start = gv_volume_start;
gp->orphan = gv_volume_orphan;
gp->access = gv_volume_access;
gp->softc = v;
first++;
TAILQ_INIT(&v->bqueue);
} else
gp = v->geom;
/* Create bio queue mutex and worker thread, if necessary. */
if (mtx_initialized(&v->bqueue_mtx) == 0)
mtx_init(&v->bqueue_mtx, "gv_plex", NULL, MTX_DEF);
if (!(v->flags & GV_VOL_THREAD_ACTIVE)) {
kthread_create(gv_vol_worker, v, NULL, 0, 0, "gv_v %s",
v->name);
v->flags |= GV_VOL_THREAD_ACTIVE;
}
/*
* Create a new consumer and attach it to the plex geom. Since this
* volume might already have a plex attached, we need to adjust the
* access counts of the new consumer.
*/
ocp = LIST_FIRST(&gp->consumer);
cp = g_new_consumer(gp);
g_attach(cp, pp);
if ((ocp != NULL) && (ocp->acr > 0 || ocp->acw > 0 || ocp->ace > 0)) {
error = g_access(cp, ocp->acr, ocp->acw, ocp->ace);
if (error) {
printf("GEOM_VINUM: failed g_access %s -> %s; "
"errno %d\n", v->name, p->name, error);
g_detach(cp);
g_destroy_consumer(cp);
if (first)
g_destroy_geom(gp);
return (NULL);
}
}
p->consumer = cp;
if (p->vol_sc != v) {
p->vol_sc = v;
v->plexcount++;
LIST_INSERT_HEAD(&v->plexes, p, in_volume);
}
/* We need to setup a new VINUMVOLUME geom. */
if (first) {
pp2 = g_new_providerf(gp, "gvinum/%s", v->name);
pp2->mediasize = pp->mediasize;
pp2->sectorsize = pp->sectorsize;
g_error_provider(pp2, 0);
v->size = pp2->mediasize;
v->geom = gp;
return (gp);
}
return (NULL);
}
static int
gv_volume_destroy_geom(struct gctl_req *req, struct g_class *mp,
struct g_geom *gp)
{
struct gv_volume *v;
g_trace(G_T_TOPOLOGY, "gv_volume_destroy_geom: %s", gp->name);
g_topology_assert();
v = gp->softc;
gv_kill_vol_thread(v);
g_wither_geom(gp, ENXIO);
return (0);
}
#define VINUMVOLUME_CLASS_NAME "VINUMVOLUME"
static struct g_class g_vinum_volume_class = {
.name = VINUMVOLUME_CLASS_NAME,
.version = G_VERSION,
.taste = gv_volume_taste,
.destroy_geom = gv_volume_destroy_geom,
};
DECLARE_GEOM_CLASS(g_vinum_volume_class, g_vinum_volume);