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freebsd-nq/sys/geom/geom_subr.c
Poul-Henning Kamp 8ebd558f5d Implement a handle for efficient implementation of perforations in 
lower extremities.

Setting bit 4 in debugflags (sysctl kern.geom.debugflags=16) will
allow any open to succeed on rank#1 providers.  This will generally
correspond to the physical disk devices: ad0, da0, md0 etc.

This fundamentally violates the mechanics of GEOMs autoconfiguration,
and is only provided as a debugging facility, so obviously error
reports on GEOM where this bit is or has been set will not be
accepted.
2003-02-12 09:48:27 +00:00

759 lines
19 KiB
C
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/*-
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/stdint.h>
#ifndef _KERNEL
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <err.h>
#else
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#endif
#include <sys/errno.h>
#include <sys/sbuf.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
#include <geom/geom_stats.h>
#include <machine/stdarg.h>
struct class_list_head g_classes = LIST_HEAD_INITIALIZER(g_classes);
static struct g_tailq_head geoms = TAILQ_HEAD_INITIALIZER(geoms);
static int g_nproviders;
char *g_wait_event, *g_wait_up, *g_wait_down, *g_wait_sim;
static int g_ignition;
void
g_add_class(struct g_class *mp)
{
if (!g_ignition) {
g_ignition++;
g_init();
}
mp->protect = 0x020016600;
g_topology_lock();
g_trace(G_T_TOPOLOGY, "g_add_class(%s)", mp->name);
LIST_INIT(&mp->geom);
LIST_INSERT_HEAD(&g_classes, mp, class);
if (g_nproviders > 0)
g_post_event(EV_NEW_CLASS, mp, NULL, NULL, NULL);
g_topology_unlock();
}
struct g_geom *
g_new_geomf(struct g_class *mp, const char *fmt, ...)
{
struct g_geom *gp;
va_list ap;
struct sbuf *sb;
g_topology_assert();
va_start(ap, fmt);
sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
sbuf_vprintf(sb, fmt, ap);
sbuf_finish(sb);
gp = g_malloc(sizeof *gp, M_ZERO);
gp->protect = 0x020016601;
gp->name = g_malloc(sbuf_len(sb) + 1, M_ZERO);
gp->class = mp;
gp->rank = 1;
LIST_INIT(&gp->consumer);
LIST_INIT(&gp->provider);
LIST_INSERT_HEAD(&mp->geom, gp, geom);
TAILQ_INSERT_HEAD(&geoms, gp, geoms);
strcpy(gp->name, sbuf_data(sb));
sbuf_delete(sb);
return (gp);
}
void
g_destroy_geom(struct g_geom *gp)
{
g_trace(G_T_TOPOLOGY, "g_destroy_geom(%p(%s))", gp, gp->name);
g_topology_assert();
KASSERT(gp->event == NULL, ("g_destroy_geom() with event"));
KASSERT(LIST_EMPTY(&gp->consumer),
("g_destroy_geom(%s) with consumer(s) [%p]",
gp->name, LIST_FIRST(&gp->consumer)));
KASSERT(LIST_EMPTY(&gp->provider),
("g_destroy_geom(%s) with provider(s) [%p]",
gp->name, LIST_FIRST(&gp->consumer)));
LIST_REMOVE(gp, geom);
TAILQ_REMOVE(&geoms, gp, geoms);
g_free(gp->name);
g_free(gp);
}
struct g_consumer *
g_new_consumer(struct g_geom *gp)
{
struct g_consumer *cp;
g_topology_assert();
KASSERT(gp->orphan != NULL,
("g_new_consumer on geom(%s) (class %s) without orphan",
gp->name, gp->class->name));
cp = g_malloc(sizeof *cp, M_ZERO);
cp->protect = 0x020016602;
cp->geom = gp;
cp->stat = g_stat_new(cp);
LIST_INSERT_HEAD(&gp->consumer, cp, consumer);
return(cp);
}
void
g_destroy_consumer(struct g_consumer *cp)
{
g_trace(G_T_TOPOLOGY, "g_destroy_consumer(%p)", cp);
g_topology_assert();
KASSERT(cp->event == NULL, ("g_destroy_consumer() with event"));
KASSERT (cp->provider == NULL, ("g_destroy_consumer but attached"));
KASSERT (cp->acr == 0, ("g_destroy_consumer with acr"));
KASSERT (cp->acw == 0, ("g_destroy_consumer with acw"));
KASSERT (cp->ace == 0, ("g_destroy_consumer with ace"));
LIST_REMOVE(cp, consumer);
g_stat_delete(cp->stat);
g_free(cp);
}
struct g_provider *
g_new_providerf(struct g_geom *gp, const char *fmt, ...)
{
struct g_provider *pp;
struct sbuf *sb;
va_list ap;
g_topology_assert();
va_start(ap, fmt);
sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
sbuf_vprintf(sb, fmt, ap);
sbuf_finish(sb);
pp = g_malloc(sizeof *pp + sbuf_len(sb) + 1, M_ZERO);
pp->protect = 0x020016603;
pp->name = (char *)(pp + 1);
strcpy(pp->name, sbuf_data(sb));
sbuf_delete(sb);
LIST_INIT(&pp->consumers);
pp->error = ENXIO;
pp->geom = gp;
pp->stat = g_stat_new(pp);
LIST_INSERT_HEAD(&gp->provider, pp, provider);
g_nproviders++;
g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
return (pp);
}
void
g_error_provider(struct g_provider *pp, int error)
{
pp->error = error;
}
void
g_destroy_provider(struct g_provider *pp)
{
struct g_geom *gp;
struct g_consumer *cp;
g_topology_assert();
KASSERT(pp->event == NULL, ("g_destroy_provider() with event"));
KASSERT(LIST_EMPTY(&pp->consumers),
("g_destroy_provider but attached"));
KASSERT (pp->acr == 0, ("g_destroy_provider with acr"));
KASSERT (pp->acw == 0, ("g_destroy_provider with acw"));
KASSERT (pp->acw == 0, ("g_destroy_provider with ace"));
g_nproviders--;
LIST_REMOVE(pp, provider);
gp = pp->geom;
g_stat_delete(pp->stat);
g_free(pp);
if (!(gp->flags & G_GEOM_WITHER))
return;
if (!LIST_EMPTY(&gp->provider))
return;
for (;;) {
cp = LIST_FIRST(&gp->consumer);
if (cp == NULL)
break;
g_detach(cp);
g_destroy_consumer(cp);
}
g_destroy_geom(gp);
}
/*
* We keep the "geoms" list sorted by topological order (== increasing
* numerical rank) at all times.
* When an attach is done, the attaching geoms rank is invalidated
* and it is moved to the tail of the list.
* All geoms later in the sequence has their ranks reevaluated in
* sequence. If we cannot assign rank to a geom because it's
* prerequisites do not have rank, we move that element to the tail
* of the sequence with invalid rank as well.
* At some point we encounter our original geom and if we stil fail
* to assign it a rank, there must be a loop and we fail back to
* g_attach() which detach again and calls redo_rank again
* to fix up the damage.
* It would be much simpler code wise to do it recursively, but we
* can't risk that on the kernel stack.
*/
static int
redo_rank(struct g_geom *gp)
{
struct g_consumer *cp;
struct g_geom *gp1, *gp2;
int n, m;
g_topology_assert();
/* Invalidate this geoms rank and move it to the tail */
gp1 = TAILQ_NEXT(gp, geoms);
if (gp1 != NULL) {
gp->rank = 0;
TAILQ_REMOVE(&geoms, gp, geoms);
TAILQ_INSERT_TAIL(&geoms, gp, geoms);
} else {
gp1 = gp;
}
/* re-rank the rest of the sequence */
for (; gp1 != NULL; gp1 = gp2) {
gp1->rank = 0;
m = 1;
LIST_FOREACH(cp, &gp1->consumer, consumer) {
if (cp->provider == NULL)
continue;
n = cp->provider->geom->rank;
if (n == 0) {
m = 0;
break;
} else if (n >= m)
m = n + 1;
}
gp1->rank = m;
gp2 = TAILQ_NEXT(gp1, geoms);
/* got a rank, moving on */
if (m != 0)
continue;
/* no rank to original geom means loop */
if (gp == gp1)
return (ELOOP);
/* no rank, put it at the end move on */
TAILQ_REMOVE(&geoms, gp1, geoms);
TAILQ_INSERT_TAIL(&geoms, gp1, geoms);
}
return (0);
}
int
g_attach(struct g_consumer *cp, struct g_provider *pp)
{
int error;
g_topology_assert();
KASSERT(cp->provider == NULL, ("attach but attached"));
cp->provider = pp;
LIST_INSERT_HEAD(&pp->consumers, cp, consumers);
error = redo_rank(cp->geom);
if (error) {
LIST_REMOVE(cp, consumers);
cp->provider = NULL;
redo_rank(cp->geom);
}
return (error);
}
void
g_detach(struct g_consumer *cp)
{
struct g_provider *pp;
g_trace(G_T_TOPOLOGY, "g_detach(%p)", cp);
KASSERT(cp != (void*)0xd0d0d0d0, ("ARGH!"));
g_topology_assert();
KASSERT(cp->provider != NULL, ("detach but not attached"));
KASSERT(cp->acr == 0, ("detach but nonzero acr"));
KASSERT(cp->acw == 0, ("detach but nonzero acw"));
KASSERT(cp->ace == 0, ("detach but nonzero ace"));
KASSERT(cp->stat->nop == cp->stat->nend,
("detach with active requests"));
pp = cp->provider;
LIST_REMOVE(cp, consumers);
cp->provider = NULL;
if (LIST_EMPTY(&pp->consumers)) {
if (pp->geom->flags & G_GEOM_WITHER)
g_destroy_provider(pp);
}
redo_rank(cp->geom);
}
/*
* g_access_abs()
*
* Access-check with absolute new values: Just fall through
* and use the relative version.
*/
int
g_access_abs(struct g_consumer *cp, int acr, int acw, int ace)
{
g_topology_assert();
return(g_access_rel(cp,
acr - cp->acr,
acw - cp->acw,
ace - cp->ace));
}
/*
* g_access_rel()
*
* Access-check with delta values. The question asked is "can provider
* "cp" change the access counters by the relative amounts dc[rwe] ?"
*/
int
g_access_rel(struct g_consumer *cp, int dcr, int dcw, int dce)
{
struct g_provider *pp;
int pr,pw,pe;
int error;
pp = cp->provider;
g_trace(G_T_ACCESS, "g_access_rel(%p(%s), %d, %d, %d)",
cp, pp->name, dcr, dcw, dce);
g_topology_assert();
KASSERT(cp->provider != NULL, ("access but not attached"));
KASSERT(cp->acr + dcr >= 0, ("access resulting in negative acr"));
KASSERT(cp->acw + dcw >= 0, ("access resulting in negative acw"));
KASSERT(cp->ace + dce >= 0, ("access resulting in negative ace"));
KASSERT(pp->geom->access != NULL, ("NULL geom->access"));
/*
* If our class cares about being spoiled, and we have been, we
* are probably just ahead of the event telling us that. Fail
* now rather than having to unravel this later.
*/
if (cp->geom->spoiled != NULL && cp->spoiled) {
KASSERT(dcr >= 0, ("spoiled but dcr = %d", dcr));
KASSERT(dcw >= 0, ("spoiled but dce = %d", dcw));
KASSERT(dce >= 0, ("spoiled but dcw = %d", dce));
KASSERT(cp->acr == 0, ("spoiled but cp->acr = %d", cp->acr));
KASSERT(cp->acw == 0, ("spoiled but cp->acw = %d", cp->acw));
KASSERT(cp->ace == 0, ("spoiled but cp->ace = %d", cp->ace));
return(ENXIO);
}
/*
* Figure out what counts the provider would have had, if this
* consumer had (r0w0e0) at this time.
*/
pr = pp->acr - cp->acr;
pw = pp->acw - cp->acw;
pe = pp->ace - cp->ace;
g_trace(G_T_ACCESS,
"open delta:[r%dw%de%d] old:[r%dw%de%d] provider:[r%dw%de%d] %p(%s)",
dcr, dcw, dce,
cp->acr, cp->acw, cp->ace,
pp->acr, pp->acw, pp->ace,
pp, pp->name);
/* If foot-shooting is enabled, any open on rank#1 is OK */
if ((g_debugflags & 16) && pp->geom->rank == 1)
;
/* If we try exclusive but already write: fail */
else if (dce > 0 && pw > 0)
return (EPERM);
/* If we try write but already exclusive: fail */
else if (dcw > 0 && pe > 0)
return (EPERM);
/* If we try to open more but provider is error'ed: fail */
else if ((dcr > 0 || dcw > 0 || dce > 0) && pp->error != 0)
return (pp->error);
/* Ok then... */
/*
* If we open first write, spoil any partner consumers.
* If we close last write, trigger re-taste.
*/
if (pp->acw == 0 && dcw != 0)
g_spoil(pp, cp);
else if (pp->acw != 0 && pp->acw == -dcw &&
!(pp->geom->flags & G_GEOM_WITHER))
g_post_event(EV_NEW_PROVIDER, NULL, NULL, pp, NULL);
error = pp->geom->access(pp, dcr, dcw, dce);
if (!error) {
pp->acr += dcr;
pp->acw += dcw;
pp->ace += dce;
cp->acr += dcr;
cp->acw += dcw;
cp->ace += dce;
}
return (error);
}
int
g_handleattr_int(struct bio *bp, const char *attribute, int val)
{
return (g_handleattr(bp, attribute, &val, sizeof val));
}
int
g_handleattr_off_t(struct bio *bp, const char *attribute, off_t val)
{
return (g_handleattr(bp, attribute, &val, sizeof val));
}
int
g_handleattr(struct bio *bp, const char *attribute, void *val, int len)
{
int error;
if (strcmp(bp->bio_attribute, attribute))
return (0);
if (bp->bio_length != len) {
printf("bio_length %jd len %d -> EFAULT\n",
(intmax_t)bp->bio_length, len);
error = EFAULT;
} else {
error = 0;
bcopy(val, bp->bio_data, len);
bp->bio_completed = len;
}
g_io_deliver(bp, error);
return (1);
}
int
g_std_access(struct g_provider *pp __unused,
int dr __unused, int dw __unused, int de __unused)
{
return (0);
}
void
g_std_done(struct bio *bp)
{
struct bio *bp2;
bp2 = bp->bio_parent;
if (bp2->bio_error == 0)
bp2->bio_error = bp->bio_error;
bp2->bio_completed += bp->bio_completed;
g_destroy_bio(bp);
bp2->bio_inbed++;
if (bp2->bio_children == bp2->bio_inbed)
g_io_deliver(bp2, bp2->bio_error);
}
/* XXX: maybe this is only g_slice_spoiled */
void
g_std_spoiled(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_provider *pp;
g_trace(G_T_TOPOLOGY, "g_std_spoiled(%p)", cp);
g_topology_assert();
g_detach(cp);
gp = cp->geom;
LIST_FOREACH(pp, &gp->provider, provider)
g_orphan_provider(pp, ENXIO);
g_destroy_consumer(cp);
if (LIST_EMPTY(&gp->provider) && LIST_EMPTY(&gp->consumer))
g_destroy_geom(gp);
else
gp->flags |= G_GEOM_WITHER;
}
/*
* Spoiling happens when a provider is opened for writing, but consumers
* which are configured by in-band data are attached (slicers for instance).
* Since the write might potentially change the in-band data, such consumers
* need to re-evaluate their existence after the writing session closes.
* We do this by (offering to) tear them down when the open for write happens
* in return for a re-taste when it closes again.
* Together with the fact that such consumers grab an 'e' bit whenever they
* are open, regardless of mode, this ends up DTRT.
*/
void
g_spoil(struct g_provider *pp, struct g_consumer *cp)
{
struct g_consumer *cp2;
g_topology_assert();
if (!strcmp(pp->name, "geom.ctl"))
return;
LIST_FOREACH(cp2, &pp->consumers, consumers) {
if (cp2 == cp)
continue;
/*
KASSERT(cp2->acr == 0, ("spoiling cp->acr = %d", cp2->acr));
KASSERT(cp2->acw == 0, ("spoiling cp->acw = %d", cp2->acw));
*/
KASSERT(cp2->ace == 0, ("spoiling cp->ace = %d", cp2->ace));
cp2->spoiled++;
}
g_post_event(EV_SPOILED, NULL, NULL, pp, cp);
}
static struct g_class *
g_class_by_name(const char *name)
{
struct g_class *mp;
g_trace(G_T_TOPOLOGY, "g_class_by_name(%s)", name);
g_topology_assert();
LIST_FOREACH(mp, &g_classes, class)
if (!strcmp(mp->name, name))
return (mp);
return (NULL);
}
struct g_geom *
g_insert_geom(const char *class, struct g_consumer *cp)
{
struct g_class *mp;
struct g_geom *gp;
struct g_provider *pp, *pp2;
struct g_consumer *cp2;
int error;
g_trace(G_T_TOPOLOGY, "g_insert_geomf(%s, %p)", class, cp);
g_topology_assert();
KASSERT(cp->provider != NULL, ("g_insert_geomf but not attached"));
/* XXX: check for events ?? */
mp = g_class_by_name(class);
if (mp == NULL)
return (NULL);
if (mp->config == NULL)
return (NULL);
pp = cp->provider;
gp = mp->taste(mp, pp, G_TF_TRANSPARENT);
if (gp == NULL)
return (NULL);
pp2 = LIST_FIRST(&gp->provider);
cp2 = LIST_FIRST(&gp->consumer);
cp2->acr += pp->acr;
cp2->acw += pp->acw;
cp2->ace += pp->ace;
pp2->acr += pp->acr;
pp2->acw += pp->acw;
pp2->ace += pp->ace;
LIST_REMOVE(cp, consumers);
LIST_INSERT_HEAD(&pp2->consumers, cp, consumers);
cp->provider = pp2;
error = redo_rank(gp);
KASSERT(error == 0, ("redo_rank failed in g_insert_geom"));
return (gp);
}
int
g_getattr__(const char *attr, struct g_consumer *cp, void *var, int len)
{
int error, i;
i = len;
error = g_io_getattr(attr, cp, &i, var);
if (error)
return (error);
if (i != len)
return (EINVAL);
return (0);
}
/*
* Check if the given pointer is a live object
*/
void
g_sanity(void *ptr)
{
struct g_class *mp;
struct g_geom *gp;
struct g_consumer *cp;
struct g_provider *pp;
if (!(g_debugflags & 0x8))
return;
LIST_FOREACH(mp, &g_classes, class) {
KASSERT(mp != ptr, ("Ptr is live class"));
KASSERT(mp->protect == 0x20016600,
("corrupt class %p %x", mp, mp->protect));
LIST_FOREACH(gp, &mp->geom, geom) {
KASSERT(gp != ptr, ("Ptr is live geom"));
KASSERT(gp->protect == 0x20016601,
("corrupt geom, %p %x", gp, gp->protect));
KASSERT(gp->name != ptr, ("Ptr is live geom's name"));
LIST_FOREACH(cp, &gp->consumer, consumer) {
KASSERT(cp != ptr, ("Ptr is live consumer"));
KASSERT(cp->protect == 0x20016602,
("corrupt consumer %p %x",
cp, cp->protect));
}
LIST_FOREACH(pp, &gp->provider, provider) {
KASSERT(pp != ptr, ("Ptr is live provider"));
KASSERT(pp->protect == 0x20016603,
("corrupt provider %p %x",
pp, pp->protect));
}
}
}
}
#ifdef _KERNEL
struct g_class *
g_idclass(struct geomidorname *p)
{
struct g_class *mp;
char *n;
if (p->len == 0) {
LIST_FOREACH(mp, &g_classes, class)
if ((uintptr_t)mp == p->u.id)
return (mp);
return (NULL);
}
n = g_malloc(p->len + 1, 0);
if (copyin(p->u.name, n, p->len) == 0) {
n[p->len] = '\0';
LIST_FOREACH(mp, &g_classes, class)
if (!bcmp(n, mp->name, p->len + 1)) {
g_free(n);
return (mp);
}
}
g_free(n);
return (NULL);
}
struct g_geom *
g_idgeom(struct geomidorname *p)
{
struct g_class *mp;
struct g_geom *gp;
char *n;
if (p->len == 0) {
LIST_FOREACH(mp, &g_classes, class)
LIST_FOREACH(gp, &mp->geom, geom)
if ((uintptr_t)gp == p->u.id)
return (gp);
return (NULL);
}
n = g_malloc(p->len + 1, 0);
if (copyin(p->u.name, n, p->len) == 0) {
n[p->len] = '\0';
LIST_FOREACH(mp, &g_classes, class)
LIST_FOREACH(gp, &mp->geom, geom)
if (!bcmp(n, gp->name, p->len + 1)) {
g_free(n);
return (gp);
}
}
g_free(n);
return (NULL);
}
struct g_provider *
g_idprovider(struct geomidorname *p)
{
struct g_class *mp;
struct g_geom *gp;
struct g_provider *pp;
char *n;
if (p->len == 0) {
LIST_FOREACH(mp, &g_classes, class)
LIST_FOREACH(gp, &mp->geom, geom)
LIST_FOREACH(pp, &gp->provider, provider)
if ((uintptr_t)pp == p->u.id)
return (pp);
return (NULL);
}
n = g_malloc(p->len + 1, 0);
if (copyin(p->u.name, n, p->len) == 0) {
n[p->len] = '\0';
LIST_FOREACH(mp, &g_classes, class)
LIST_FOREACH(gp, &mp->geom, geom)
LIST_FOREACH(pp, &gp->provider, provider)
if (!bcmp(n, pp->name, p->len + 1)) {
g_free(n);
return (pp);
}
}
g_free(n);
return (NULL);
}
#endif /* _KERNEL */
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