freebsd-dev/sys/geom/mountver/g_mountver.c
2020-09-01 22:14:09 +00:00

694 lines
17 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010 Edward Tomasz Napierala <trasz@FreeBSD.org>
* Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@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.
*/
#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/disk.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/eventhandler.h>
#include <geom/geom.h>
#include <geom/geom_dbg.h>
#include <geom/mountver/g_mountver.h>
SYSCTL_DECL(_kern_geom);
static SYSCTL_NODE(_kern_geom, OID_AUTO, mountver, CTLFLAG_RW | CTLFLAG_MPSAFE,
0, "GEOM_MOUNTVER stuff");
static u_int g_mountver_debug = 0;
static u_int g_mountver_check_ident = 1;
SYSCTL_UINT(_kern_geom_mountver, OID_AUTO, debug, CTLFLAG_RW,
&g_mountver_debug, 0, "Debug level");
SYSCTL_UINT(_kern_geom_mountver, OID_AUTO, check_ident, CTLFLAG_RW,
&g_mountver_check_ident, 0, "Check disk ident when reattaching");
static eventhandler_tag g_mountver_pre_sync = NULL;
static void g_mountver_queue(struct bio *bp);
static void g_mountver_orphan(struct g_consumer *cp);
static void g_mountver_resize(struct g_consumer *cp);
static int g_mountver_destroy(struct g_geom *gp, boolean_t force);
static g_taste_t g_mountver_taste;
static int g_mountver_destroy_geom(struct gctl_req *req, struct g_class *mp,
struct g_geom *gp);
static void g_mountver_config(struct gctl_req *req, struct g_class *mp,
const char *verb);
static void g_mountver_dumpconf(struct sbuf *sb, const char *indent,
struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
static void g_mountver_init(struct g_class *mp);
static void g_mountver_fini(struct g_class *mp);
struct g_class g_mountver_class = {
.name = G_MOUNTVER_CLASS_NAME,
.version = G_VERSION,
.ctlreq = g_mountver_config,
.taste = g_mountver_taste,
.destroy_geom = g_mountver_destroy_geom,
.init = g_mountver_init,
.fini = g_mountver_fini
};
static void
g_mountver_detach(void *arg, int flags __unused)
{
struct g_consumer *cp = arg;
g_topology_assert();
if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
g_access(cp, -cp->acr, -cp->acw, -cp->ace);
g_detach(cp);
}
static void
g_mountver_done(struct bio *bp)
{
struct g_mountver_softc *sc;
struct g_geom *gp;
struct g_consumer *cp;
struct bio *pbp;
cp = bp->bio_from;
gp = cp->geom;
if (bp->bio_error != ENXIO) {
g_std_done(bp);
goto done;
}
/*
* When the device goes away, it's possible that few requests
* will be completed with ENXIO before g_mountver_orphan()
* gets called. To work around that, we have to queue requests
* that failed with ENXIO, in order to send them later.
*/
pbp = bp->bio_parent;
KASSERT(pbp->bio_to == LIST_FIRST(&gp->provider),
("parent request was for someone else"));
g_destroy_bio(bp);
pbp->bio_inbed++;
g_mountver_queue(pbp);
done:
sc = gp->softc;
mtx_lock(&sc->sc_mtx);
if (--cp->index == 0 && sc->sc_orphaned)
g_post_event(g_mountver_detach, cp, M_NOWAIT, NULL);
mtx_unlock(&sc->sc_mtx);
}
/*
* Send the BIO down. The function is called with sc_mtx held to cover
* the race with orphan, but drops it before external calls.
*/
static void
g_mountver_send(struct g_geom *gp, struct bio *bp)
{
struct g_mountver_softc *sc = gp->softc;
struct g_consumer *cp;
struct bio *cbp;
mtx_assert(&sc->sc_mtx, MA_OWNED);
cbp = g_clone_bio(bp);
if (cbp == NULL) {
mtx_unlock(&sc->sc_mtx);
g_io_deliver(bp, ENOMEM);
return;
}
cp = LIST_FIRST(&gp->consumer);
cp->index++;
mtx_unlock(&sc->sc_mtx);
cbp->bio_done = g_mountver_done;
g_io_request(cbp, cp);
}
static void
g_mountver_queue(struct bio *bp)
{
struct g_mountver_softc *sc;
struct g_geom *gp;
gp = bp->bio_to->geom;
sc = gp->softc;
mtx_lock(&sc->sc_mtx);
TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
mtx_unlock(&sc->sc_mtx);
}
static void
g_mountver_send_queued(struct g_geom *gp)
{
struct g_mountver_softc *sc;
struct bio *bp;
sc = gp->softc;
mtx_lock(&sc->sc_mtx);
while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL && !sc->sc_orphaned) {
TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
G_MOUNTVER_LOGREQ(bp, "Sending queued request.");
/* sc_mtx is dropped inside */
g_mountver_send(gp, bp);
mtx_lock(&sc->sc_mtx);
}
mtx_unlock(&sc->sc_mtx);
}
static void
g_mountver_discard_queued(struct g_geom *gp)
{
struct g_mountver_softc *sc;
struct bio *bp;
sc = gp->softc;
mtx_lock(&sc->sc_mtx);
while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL) {
TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
mtx_unlock(&sc->sc_mtx);
G_MOUNTVER_LOGREQ(bp, "Discarding queued request.");
g_io_deliver(bp, ENXIO);
mtx_lock(&sc->sc_mtx);
}
mtx_unlock(&sc->sc_mtx);
}
static void
g_mountver_start(struct bio *bp)
{
struct g_mountver_softc *sc;
struct g_geom *gp;
gp = bp->bio_to->geom;
sc = gp->softc;
G_MOUNTVER_LOGREQ(bp, "Request received.");
/*
* It is possible that some bios were returned with ENXIO, even though
* orphaning didn't happen yet. In that case, queue all subsequent
* requests in order to maintain ordering.
*/
mtx_lock(&sc->sc_mtx);
if (sc->sc_orphaned || !TAILQ_EMPTY(&sc->sc_queue)) {
mtx_unlock(&sc->sc_mtx);
if (sc->sc_shutting_down) {
G_MOUNTVER_LOGREQ(bp, "Discarding request due to shutdown.");
g_io_deliver(bp, ENXIO);
return;
}
G_MOUNTVER_LOGREQ(bp, "Queueing request.");
g_mountver_queue(bp);
if (!sc->sc_orphaned)
g_mountver_send_queued(gp);
} else {
G_MOUNTVER_LOGREQ(bp, "Sending request.");
/* sc_mtx is dropped inside */
g_mountver_send(gp, bp);
}
}
static int
g_mountver_access(struct g_provider *pp, int dr, int dw, int de)
{
struct g_mountver_softc *sc;
struct g_geom *gp;
struct g_consumer *cp;
g_topology_assert();
gp = pp->geom;
cp = LIST_FIRST(&gp->consumer);
sc = gp->softc;
if (sc == NULL && dr <= 0 && dw <= 0 && de <= 0)
return (0);
KASSERT(sc != NULL, ("Trying to access withered provider \"%s\".", pp->name));
sc->sc_access_r += dr;
sc->sc_access_w += dw;
sc->sc_access_e += de;
if (sc->sc_orphaned)
return (0);
return (g_access(cp, dr, dw, de));
}
static int
g_mountver_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp)
{
struct g_mountver_softc *sc;
struct g_geom *gp;
struct g_provider *newpp;
struct g_consumer *cp;
struct g_geom_alias *gap;
char name[64];
int error;
int identsize = DISK_IDENT_SIZE;
g_topology_assert();
gp = NULL;
newpp = NULL;
cp = NULL;
snprintf(name, sizeof(name), "%s%s", pp->name, G_MOUNTVER_SUFFIX);
LIST_FOREACH(gp, &mp->geom, geom) {
if (strcmp(gp->name, name) == 0) {
gctl_error(req, "Provider %s already exists.", name);
return (EEXIST);
}
}
gp = g_new_geomf(mp, "%s", name);
sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
mtx_init(&sc->sc_mtx, "gmountver", NULL, MTX_DEF | MTX_RECURSE);
TAILQ_INIT(&sc->sc_queue);
sc->sc_provider_name = strdup(pp->name, M_GEOM);
gp->softc = sc;
gp->start = g_mountver_start;
gp->orphan = g_mountver_orphan;
gp->resize = g_mountver_resize;
gp->access = g_mountver_access;
gp->dumpconf = g_mountver_dumpconf;
newpp = g_new_providerf(gp, "%s", gp->name);
newpp->mediasize = pp->mediasize;
newpp->sectorsize = pp->sectorsize;
newpp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
LIST_FOREACH(gap, &pp->aliases, ga_next)
g_provider_add_alias(newpp, "%s%s", gap->ga_alias, G_MOUNTVER_SUFFIX);
if ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0) {
G_MOUNTVER_DEBUG(0, "Unmapped supported for %s.", gp->name);
newpp->flags |= G_PF_ACCEPT_UNMAPPED;
} else {
G_MOUNTVER_DEBUG(0, "Unmapped unsupported for %s.", gp->name);
newpp->flags &= ~G_PF_ACCEPT_UNMAPPED;
}
cp = g_new_consumer(gp);
cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
error = g_attach(cp, pp);
if (error != 0) {
gctl_error(req, "Cannot attach to provider %s.", pp->name);
goto fail;
}
error = g_access(cp, 1, 0, 0);
if (error != 0) {
gctl_error(req, "Cannot access provider %s.", pp->name);
goto fail;
}
error = g_io_getattr("GEOM::ident", cp, &identsize, sc->sc_ident);
g_access(cp, -1, 0, 0);
if (error != 0) {
if (g_mountver_check_ident) {
gctl_error(req, "Cannot get disk ident from %s; error = %d.", pp->name, error);
goto fail;
}
G_MOUNTVER_DEBUG(0, "Cannot get disk ident from %s; error = %d.", pp->name, error);
sc->sc_ident[0] = '\0';
}
g_error_provider(newpp, 0);
G_MOUNTVER_DEBUG(0, "Device %s created.", gp->name);
return (0);
fail:
g_free(sc->sc_provider_name);
if (cp->provider != NULL)
g_detach(cp);
g_destroy_consumer(cp);
g_destroy_provider(newpp);
g_free(gp->softc);
g_destroy_geom(gp);
return (error);
}
static int
g_mountver_destroy(struct g_geom *gp, boolean_t force)
{
struct g_mountver_softc *sc;
struct g_provider *pp;
g_topology_assert();
if (gp->softc == NULL)
return (ENXIO);
sc = gp->softc;
pp = LIST_FIRST(&gp->provider);
if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
if (force) {
G_MOUNTVER_DEBUG(0, "Device %s is still open, so it "
"can't be definitely removed.", pp->name);
} else {
G_MOUNTVER_DEBUG(1, "Device %s is still open (r%dw%de%d).",
pp->name, pp->acr, pp->acw, pp->ace);
return (EBUSY);
}
} else {
G_MOUNTVER_DEBUG(0, "Device %s removed.", gp->name);
}
if (pp != NULL)
g_wither_provider(pp, ENXIO);
g_mountver_discard_queued(gp);
g_free(sc->sc_provider_name);
g_free(gp->softc);
gp->softc = NULL;
g_wither_geom(gp, ENXIO);
return (0);
}
static int
g_mountver_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
{
return (g_mountver_destroy(gp, 0));
}
static void
g_mountver_ctl_create(struct gctl_req *req, struct g_class *mp)
{
struct g_provider *pp;
char param[16];
int i, *nargs;
g_topology_assert();
nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
if (nargs == NULL) {
gctl_error(req, "No '%s' argument", "nargs");
return;
}
if (*nargs <= 0) {
gctl_error(req, "Missing device(s).");
return;
}
for (i = 0; i < *nargs; i++) {
snprintf(param, sizeof(param), "arg%d", i);
pp = gctl_get_provider(req, param);
if (pp == NULL)
return;
if (g_mountver_create(req, mp, pp) != 0)
return;
}
}
static struct g_geom *
g_mountver_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_mountver_ctl_destroy(struct gctl_req *req, struct g_class *mp)
{
int *nargs, *force, error, i;
struct g_geom *gp;
const char *name;
char param[16];
g_topology_assert();
nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
if (nargs == NULL) {
gctl_error(req, "No '%s' argument", "nargs");
return;
}
if (*nargs <= 0) {
gctl_error(req, "Missing device(s).");
return;
}
force = gctl_get_paraml(req, "force", sizeof(*force));
if (force == NULL) {
gctl_error(req, "No 'force' argument");
return;
}
for (i = 0; i < *nargs; i++) {
snprintf(param, sizeof(param), "arg%d", i);
name = gctl_get_asciiparam(req, param);
if (name == NULL) {
gctl_error(req, "No 'arg%d' argument", i);
return;
}
if (strncmp(name, _PATH_DEV, strlen(_PATH_DEV)) == 0)
name += strlen(_PATH_DEV);
gp = g_mountver_find_geom(mp, name);
if (gp == NULL) {
G_MOUNTVER_DEBUG(1, "Device %s is invalid.", name);
gctl_error(req, "Device %s is invalid.", name);
return;
}
error = g_mountver_destroy(gp, *force);
if (error != 0) {
gctl_error(req, "Cannot destroy device %s (error=%d).",
gp->name, error);
return;
}
}
}
static void
g_mountver_orphan(struct g_consumer *cp)
{
struct g_mountver_softc *sc;
int done;
g_topology_assert();
sc = cp->geom->softc;
mtx_lock(&sc->sc_mtx);
sc->sc_orphaned = 1;
done = (cp->index == 0);
mtx_unlock(&sc->sc_mtx);
if (done)
g_mountver_detach(cp, 0);
G_MOUNTVER_DEBUG(0, "%s is offline. Mount verification in progress.", sc->sc_provider_name);
}
static void
g_mountver_resize(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_provider *pp;
gp = cp->geom;
LIST_FOREACH(pp, &gp->provider, provider)
g_resize_provider(pp, cp->provider->mediasize);
}
static int
g_mountver_ident_matches(struct g_geom *gp)
{
struct g_consumer *cp;
struct g_mountver_softc *sc;
char ident[DISK_IDENT_SIZE];
int error, identsize = DISK_IDENT_SIZE;
sc = gp->softc;
cp = LIST_FIRST(&gp->consumer);
if (g_mountver_check_ident == 0)
return (0);
error = g_access(cp, 1, 0, 0);
if (error != 0) {
G_MOUNTVER_DEBUG(0, "Cannot access %s; "
"not attaching; error = %d.", gp->name, error);
return (1);
}
error = g_io_getattr("GEOM::ident", cp, &identsize, ident);
g_access(cp, -1, 0, 0);
if (error != 0) {
G_MOUNTVER_DEBUG(0, "Cannot get disk ident for %s; "
"not attaching; error = %d.", gp->name, error);
return (1);
}
if (strcmp(ident, sc->sc_ident) != 0) {
G_MOUNTVER_DEBUG(1, "Disk ident for %s (\"%s\") is different "
"from expected \"%s\", not attaching.", gp->name, ident,
sc->sc_ident);
return (1);
}
return (0);
}
static struct g_geom *
g_mountver_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
struct g_mountver_softc *sc;
struct g_consumer *cp;
struct g_geom *gp;
int error;
g_topology_assert();
g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
G_MOUNTVER_DEBUG(2, "Tasting %s.", pp->name);
/*
* Let's check if device already exists.
*/
LIST_FOREACH(gp, &mp->geom, geom) {
sc = gp->softc;
if (sc == NULL)
continue;
/* Already attached? */
if (pp == LIST_FIRST(&gp->provider))
return (NULL);
if (sc->sc_orphaned && strcmp(pp->name, sc->sc_provider_name) == 0)
break;
}
if (gp == NULL)
return (NULL);
cp = LIST_FIRST(&gp->consumer);
g_attach(cp, pp);
error = g_mountver_ident_matches(gp);
if (error != 0) {
g_detach(cp);
return (NULL);
}
if (sc->sc_access_r > 0 || sc->sc_access_w > 0 || sc->sc_access_e > 0) {
error = g_access(cp, sc->sc_access_r, sc->sc_access_w, sc->sc_access_e);
if (error != 0) {
G_MOUNTVER_DEBUG(0, "Cannot access %s; error = %d.", pp->name, error);
g_detach(cp);
return (NULL);
}
}
sc->sc_orphaned = 0;
g_mountver_send_queued(gp);
G_MOUNTVER_DEBUG(0, "%s has completed mount verification.", sc->sc_provider_name);
return (gp);
}
static void
g_mountver_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 '%s' argument.", "version");
return;
}
if (*version != G_MOUNTVER_VERSION) {
gctl_error(req, "Userland and kernel parts are out of sync.");
return;
}
if (strcmp(verb, "create") == 0) {
g_mountver_ctl_create(req, mp);
return;
} else if (strcmp(verb, "destroy") == 0) {
g_mountver_ctl_destroy(req, mp);
return;
}
gctl_error(req, "Unknown verb.");
}
static void
g_mountver_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
struct g_consumer *cp, struct g_provider *pp)
{
struct g_mountver_softc *sc;
if (pp != NULL || cp != NULL)
return;
sc = gp->softc;
sbuf_printf(sb, "%s<State>%s</State>\n", indent,
sc->sc_orphaned ? "OFFLINE" : "ONLINE");
sbuf_printf(sb, "%s<Provider-Name>%s</Provider-Name>\n", indent, sc->sc_provider_name);
sbuf_printf(sb, "%s<Disk-Ident>%s</Disk-Ident>\n", indent, sc->sc_ident);
}
static void
g_mountver_shutdown_pre_sync(void *arg, int howto)
{
struct g_mountver_softc *sc;
struct g_class *mp;
struct g_geom *gp, *gp2;
mp = arg;
g_topology_lock();
LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
if (gp->softc == NULL)
continue;
sc = gp->softc;
sc->sc_shutting_down = 1;
if (sc->sc_orphaned)
g_mountver_destroy(gp, 1);
}
g_topology_unlock();
}
static void
g_mountver_init(struct g_class *mp)
{
g_mountver_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
g_mountver_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
if (g_mountver_pre_sync == NULL)
G_MOUNTVER_DEBUG(0, "Warning! Cannot register shutdown event.");
}
static void
g_mountver_fini(struct g_class *mp)
{
if (g_mountver_pre_sync != NULL)
EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_mountver_pre_sync);
}
DECLARE_GEOM_CLASS(g_mountver_class, g_mountver);
MODULE_VERSION(geom_mountver, 0);