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freebsd/sys/geom/geom_dev.c
Alexander Motin 107c1508fa Temporary revert r227009 to fix freeze on UP systems without PREEMPTION.
Before r215687, if some withered geom or provider could not be destroyed,
g_event thread went to sleep for 0.1s before retrying. After that change
it is just restarting immediately. r227009 made orphaned (withered) provider
to not detach immediately, but only after context switch. That made loop
inside g_event thread infinite on UP systems without PREEMPTION.

To address original problem with possible dead lock addressed by r227009
we have to fix r215687 change first, that needs some time to think and test.
2011-11-14 19:32:05 +00:00

539 lines
14 KiB
C

/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/ctype.h>
#include <sys/bio.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/disk.h>
#include <sys/fcntl.h>
#include <sys/limits.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
#include <machine/stdarg.h>
/*
* Use the consumer private field to reference a physdev alias (if any).
*/
#define cp_alias_dev private
static d_open_t g_dev_open;
static d_close_t g_dev_close;
static d_strategy_t g_dev_strategy;
static d_ioctl_t g_dev_ioctl;
static struct cdevsw g_dev_cdevsw = {
.d_version = D_VERSION,
.d_open = g_dev_open,
.d_close = g_dev_close,
.d_read = physread,
.d_write = physwrite,
.d_ioctl = g_dev_ioctl,
.d_strategy = g_dev_strategy,
.d_name = "g_dev",
.d_flags = D_DISK | D_TRACKCLOSE,
};
static g_taste_t g_dev_taste;
static g_orphan_t g_dev_orphan;
static g_attrchanged_t g_dev_attrchanged;
static struct g_class g_dev_class = {
.name = "DEV",
.version = G_VERSION,
.taste = g_dev_taste,
.orphan = g_dev_orphan,
.attrchanged = g_dev_attrchanged
};
void
g_dev_print(void)
{
struct g_geom *gp;
char const *p = "";
LIST_FOREACH(gp, &g_dev_class.geom, geom) {
printf("%s%s", p, gp->name);
p = " ";
}
printf("\n");
}
static void
g_dev_attrchanged(struct g_consumer *cp, const char *attr)
{
if (strcmp(attr, "GEOM::physpath") != 0)
return;
if (g_access(cp, 1, 0, 0) == 0) {
char *physpath;
int error, physpath_len;
physpath_len = MAXPATHLEN;
physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
error =
g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
g_access(cp, -1, 0, 0);
if (error == 0 && strlen(physpath) != 0) {
struct cdev *dev;
struct cdev *old_alias_dev;
struct cdev **alias_devp;
dev = cp->geom->softc;
old_alias_dev = cp->cp_alias_dev;
alias_devp = (struct cdev **)&cp->cp_alias_dev;
make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
dev, old_alias_dev, physpath);
} else if (cp->cp_alias_dev) {
destroy_dev((struct cdev *)cp->cp_alias_dev);
cp->cp_alias_dev = NULL;
}
g_free(physpath);
}
}
struct g_provider *
g_dev_getprovider(struct cdev *dev)
{
struct g_consumer *cp;
g_topology_assert();
if (dev == NULL)
return (NULL);
if (dev->si_devsw != &g_dev_cdevsw)
return (NULL);
cp = dev->si_drv2;
return (cp->provider);
}
static struct g_geom *
g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
{
struct g_geom *gp;
struct g_consumer *cp;
int error, len;
struct cdev *dev, *adev;
char buf[64], *val;
g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
g_topology_assert();
LIST_FOREACH(cp, &pp->consumers, consumers)
if (cp->geom->class == mp)
return (NULL);
gp = g_new_geomf(mp, pp->name);
cp = g_new_consumer(gp);
error = g_attach(cp, pp);
KASSERT(error == 0,
("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
&g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
if (error != 0) {
printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
__func__, gp->name, error);
g_detach(cp);
g_destroy_consumer(cp);
g_destroy_geom(gp);
return (NULL);
}
/* Search for device alias name and create it if found. */
adev = NULL;
for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
buf[14 + len] = 0;
val = getenv(buf);
if (val != NULL) {
snprintf(buf, sizeof(buf), "%s%s",
val, gp->name + len);
freeenv(val);
make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
&adev, dev, "%s", buf);
break;
}
}
if (pp->flags & G_PF_CANDELETE)
dev->si_flags |= SI_CANDELETE;
dev->si_iosize_max = MAXPHYS;
gp->softc = dev;
dev->si_drv1 = gp;
dev->si_drv2 = cp;
if (adev != NULL) {
if (pp->flags & G_PF_CANDELETE)
adev->si_flags |= SI_CANDELETE;
adev->si_iosize_max = MAXPHYS;
adev->si_drv1 = gp;
adev->si_drv2 = cp;
}
g_dev_attrchanged(cp, "GEOM::physpath");
return (gp);
}
static int
g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct g_geom *gp;
struct g_consumer *cp;
int error, r, w, e;
gp = dev->si_drv1;
cp = dev->si_drv2;
if (gp == NULL || cp == NULL || gp->softc != dev)
return(ENXIO); /* g_dev_taste() not done yet */
g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
gp->name, flags, fmt, td);
r = flags & FREAD ? 1 : 0;
w = flags & FWRITE ? 1 : 0;
#ifdef notyet
e = flags & O_EXCL ? 1 : 0;
#else
e = 0;
#endif
if (w) {
/*
* When running in very secure mode, do not allow
* opens for writing of any disks.
*/
error = securelevel_ge(td->td_ucred, 2);
if (error)
return (error);
}
g_topology_lock();
if (dev->si_devsw == NULL)
error = ENXIO; /* We were orphaned */
else
error = g_access(cp, r, w, e);
g_topology_unlock();
return(error);
}
static int
g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct g_geom *gp;
struct g_consumer *cp;
int error, r, w, e, i;
gp = dev->si_drv1;
cp = dev->si_drv2;
if (gp == NULL || cp == NULL)
return(ENXIO);
g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
gp->name, flags, fmt, td);
r = flags & FREAD ? -1 : 0;
w = flags & FWRITE ? -1 : 0;
#ifdef notyet
e = flags & O_EXCL ? -1 : 0;
#else
e = 0;
#endif
g_topology_lock();
if (dev->si_devsw == NULL)
error = ENXIO; /* We were orphaned */
else
error = g_access(cp, r, w, e);
for (i = 0; i < 10 * hz;) {
if (cp->acr != 0 || cp->acw != 0)
break;
if (cp->nstart == cp->nend)
break;
pause("gdevwclose", hz / 10);
i += hz / 10;
}
if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
printf("WARNING: Final close of geom_dev(%s) %s %s\n",
gp->name,
"still has outstanding I/O after 10 seconds.",
"Completing close anyway, panic may happen later.");
}
g_topology_unlock();
return (error);
}
/*
* XXX: Until we have unmessed the ioctl situation, there is a race against
* XXX: a concurrent orphanization. We cannot close it by holding topology
* XXX: since that would prevent us from doing our job, and stalling events
* XXX: will break (actually: stall) the BSD disklabel hacks.
*/
static int
g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
{
struct g_geom *gp;
struct g_consumer *cp;
struct g_provider *pp;
struct g_kerneldump kd;
off_t offset, length, chunk;
int i, error;
u_int u;
gp = dev->si_drv1;
cp = dev->si_drv2;
pp = cp->provider;
error = 0;
KASSERT(cp->acr || cp->acw,
("Consumer with zero access count in g_dev_ioctl"));
i = IOCPARM_LEN(cmd);
switch (cmd) {
case DIOCGSECTORSIZE:
*(u_int *)data = cp->provider->sectorsize;
if (*(u_int *)data == 0)
error = ENOENT;
break;
case DIOCGMEDIASIZE:
*(off_t *)data = cp->provider->mediasize;
if (*(off_t *)data == 0)
error = ENOENT;
break;
case DIOCGFWSECTORS:
error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
if (error == 0 && *(u_int *)data == 0)
error = ENOENT;
break;
case DIOCGFWHEADS:
error = g_io_getattr("GEOM::fwheads", cp, &i, data);
if (error == 0 && *(u_int *)data == 0)
error = ENOENT;
break;
case DIOCGFRONTSTUFF:
error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
break;
case DIOCSKERNELDUMP:
u = *((u_int *)data);
if (!u) {
set_dumper(NULL);
error = 0;
break;
}
kd.offset = 0;
kd.length = OFF_MAX;
i = sizeof kd;
error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
if (!error) {
error = set_dumper(&kd.di);
if (!error)
dev->si_flags |= SI_DUMPDEV;
}
break;
case DIOCGFLUSH:
error = g_io_flush(cp);
break;
case DIOCGDELETE:
offset = ((off_t *)data)[0];
length = ((off_t *)data)[1];
if ((offset % cp->provider->sectorsize) != 0 ||
(length % cp->provider->sectorsize) != 0 || length <= 0) {
printf("%s: offset=%jd length=%jd\n", __func__, offset,
length);
error = EINVAL;
break;
}
while (length > 0) {
chunk = length;
if (chunk > 65536 * cp->provider->sectorsize)
chunk = 65536 * cp->provider->sectorsize;
error = g_delete_data(cp, offset, chunk);
length -= chunk;
offset += chunk;
if (error)
break;
/*
* Since the request size is unbounded, the service
* time is likewise. We make this ioctl interruptible
* by checking for signals for each bio.
*/
if (SIGPENDING(td))
break;
}
break;
case DIOCGIDENT:
error = g_io_getattr("GEOM::ident", cp, &i, data);
break;
case DIOCGPROVIDERNAME:
if (pp == NULL)
return (ENOENT);
strlcpy(data, pp->name, i);
break;
case DIOCGSTRIPESIZE:
*(off_t *)data = cp->provider->stripesize;
break;
case DIOCGSTRIPEOFFSET:
*(off_t *)data = cp->provider->stripeoffset;
break;
case DIOCGPHYSPATH:
error = g_io_getattr("GEOM::physpath", cp, &i, data);
if (error == 0 && *(char *)data == '\0')
error = ENOENT;
break;
default:
if (cp->provider->geom->ioctl != NULL) {
error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
} else {
error = ENOIOCTL;
}
}
return (error);
}
static void
g_dev_done(struct bio *bp2)
{
struct bio *bp;
bp = bp2->bio_parent;
bp->bio_error = bp2->bio_error;
if (bp->bio_error != 0) {
g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
bp2, bp->bio_error);
bp->bio_flags |= BIO_ERROR;
} else {
g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
}
bp->bio_resid = bp->bio_length - bp2->bio_completed;
bp->bio_completed = bp2->bio_completed;
g_destroy_bio(bp2);
biodone(bp);
}
static void
g_dev_strategy(struct bio *bp)
{
struct g_consumer *cp;
struct bio *bp2;
struct cdev *dev;
KASSERT(bp->bio_cmd == BIO_READ ||
bp->bio_cmd == BIO_WRITE ||
bp->bio_cmd == BIO_DELETE,
("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
dev = bp->bio_dev;
cp = dev->si_drv2;
KASSERT(cp->acr || cp->acw,
("Consumer with zero access count in g_dev_strategy"));
#ifdef INVARIANTS
if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
(bp->bio_bcount % cp->provider->sectorsize) != 0) {
bp->bio_resid = bp->bio_bcount;
biofinish(bp, NULL, EINVAL);
return;
}
#endif
for (;;) {
/*
* XXX: This is not an ideal solution, but I belive it to
* XXX: deadlock safe, all things considered.
*/
bp2 = g_clone_bio(bp);
if (bp2 != NULL)
break;
pause("gdstrat", hz / 10);
}
KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
bp2->bio_done = g_dev_done;
g_trace(G_T_BIO,
"g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
bp2->bio_data, bp2->bio_cmd);
g_io_request(bp2, cp);
KASSERT(cp->acr || cp->acw,
("g_dev_strategy raced with g_dev_close and lost"));
}
/*
* g_dev_orphan()
*
* Called from below when the provider orphaned us.
* - Clear any dump settings.
* - Destroy the struct cdev *to prevent any more request from coming in. The
* provider is already marked with an error, so anything which comes in
* in the interrim will be returned immediately.
* - Wait for any outstanding I/O to finish.
* - Set our access counts to zero, whatever they were.
* - Detach and self-destruct.
*/
static void
g_dev_orphan(struct g_consumer *cp)
{
struct g_geom *gp;
struct cdev *dev;
g_topology_assert();
gp = cp->geom;
dev = gp->softc;
g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
/* Reset any dump-area set on this device */
if (dev->si_flags & SI_DUMPDEV)
set_dumper(NULL);
/* Destroy the struct cdev *so we get no more requests */
destroy_dev(dev);
/* Wait for the cows to come home */
while (cp->nstart != cp->nend)
pause("gdevorphan", hz / 10);
if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
g_access(cp, -cp->acr, -cp->acw, -cp->ace);
g_detach(cp);
g_destroy_consumer(cp);
g_destroy_geom(gp);
}
DECLARE_GEOM_CLASS(g_dev_class, g_dev);