/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2007 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/kernel.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/jail.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rmlock.h>
#include <sys/sx.h>
#include <sys/queue.h>
#include <sys/proc.h>
#include <sys/osd.h>
/* OSD (Object Specific Data) */
/*
* Lock key:
* (m) osd_module_lock
* (o) osd_object_lock
* (l) osd_list_lock
*/
struct osd_master {
struct sx osd_module_lock;
struct rmlock osd_object_lock;
struct mtx osd_list_lock;
LIST_HEAD(, osd) osd_list; /* (l) */
osd_destructor_t *osd_destructors; /* (o) */
osd_method_t *osd_methods; /* (m) */
u_int osd_ntslots; /* (m) */
const u_int osd_nmethods;
};
static MALLOC_DEFINE(M_OSD, "osd", "Object Specific Data");
static int osd_debug = 0;
SYSCTL_INT(_debug, OID_AUTO, osd, CTLFLAG_RWTUN, &osd_debug, 0, "OSD debug level");
#define OSD_DEBUG(...) do { \
if (osd_debug) { \
printf("OSD (%s:%u): ", __func__, __LINE__); \
printf(__VA_ARGS__); \
printf("\n"); \
} \
} while (0)
static void do_osd_del(u_int type, struct osd *osd, u_int slot,
int list_locked);
/*
* List of objects with OSD.
*/
struct osd_master osdm[OSD_LAST + 1] = {
[OSD_JAIL] = { .osd_nmethods = PR_MAXMETHOD },
};
static void
osd_default_destructor(void *value __unused)
{
/* Do nothing. */
}
int
osd_register(u_int type, osd_destructor_t destructor, osd_method_t *methods)
{
void *newptr;
u_int i, m;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
/*
* If no destructor is given, use default one. We need to use some
* destructor, because NULL destructor means unused slot.
*/
if (destructor == NULL)
destructor = osd_default_destructor;
sx_xlock(&osdm[type].osd_module_lock);
/*
* First, we try to find unused slot.
*/
for (i = 0; i < osdm[type].osd_ntslots; i++) {
if (osdm[type].osd_destructors[i] == NULL) {
OSD_DEBUG("Unused slot found (type=%u, slot=%u).",
type, i);
break;
}
}
/*
* If no unused slot was found, allocate one.
*/
if (i == osdm[type].osd_ntslots) {
osdm[type].osd_ntslots++;
if (osdm[type].osd_nmethods != 0)
osdm[type].osd_methods = realloc(osdm[type].osd_methods,
sizeof(osd_method_t) * osdm[type].osd_ntslots *
osdm[type].osd_nmethods, M_OSD, M_WAITOK);
newptr = malloc(sizeof(osd_destructor_t) *
osdm[type].osd_ntslots, M_OSD, M_WAITOK);
rm_wlock(&osdm[type].osd_object_lock);
bcopy(osdm[type].osd_destructors, newptr,
sizeof(osd_destructor_t) * i);
free(osdm[type].osd_destructors, M_OSD);
osdm[type].osd_destructors = newptr;
rm_wunlock(&osdm[type].osd_object_lock);
OSD_DEBUG("New slot allocated (type=%u, slot=%u).",
type, i + 1);
}
osdm[type].osd_destructors[i] = destructor;
if (osdm[type].osd_nmethods != 0) {
for (m = 0; m < osdm[type].osd_nmethods; m++)
osdm[type].osd_methods[i * osdm[type].osd_nmethods + m]
= methods != NULL ? methods[m] : NULL;
}
sx_xunlock(&osdm[type].osd_module_lock);
return (i + 1);
}
void
osd_deregister(u_int type, u_int slot)
{
struct osd *osd, *tosd;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
KASSERT(slot > 0, ("Invalid slot."));
KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
sx_xlock(&osdm[type].osd_module_lock);
rm_wlock(&osdm[type].osd_object_lock);
/*
* Free all OSD for the given slot.
*/
mtx_lock(&osdm[type].osd_list_lock);
LIST_FOREACH_SAFE(osd, &osdm[type].osd_list, osd_next, tosd)
do_osd_del(type, osd, slot, 1);
mtx_unlock(&osdm[type].osd_list_lock);
/*
* Set destructor to NULL to free the slot.
*/
osdm[type].osd_destructors[slot - 1] = NULL;
if (slot == osdm[type].osd_ntslots) {
osdm[type].osd_ntslots--;
osdm[type].osd_destructors = realloc(osdm[type].osd_destructors,
sizeof(osd_destructor_t) * osdm[type].osd_ntslots, M_OSD,
M_NOWAIT | M_ZERO);
if (osdm[type].osd_nmethods != 0)
osdm[type].osd_methods = realloc(osdm[type].osd_methods,
sizeof(osd_method_t) * osdm[type].osd_ntslots *
osdm[type].osd_nmethods, M_OSD, M_NOWAIT | M_ZERO);
/*
* We always reallocate to smaller size, so we assume it will
* always succeed.
*/
KASSERT(osdm[type].osd_destructors != NULL &&
(osdm[type].osd_nmethods == 0 ||
osdm[type].osd_methods != NULL), ("realloc() failed"));
OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).",
type, slot);
} else {
OSD_DEBUG("Slot deregistration (type=%u, slot=%u).",
type, slot);
}
rm_wunlock(&osdm[type].osd_object_lock);
sx_xunlock(&osdm[type].osd_module_lock);
}
int
osd_set(u_int type, struct osd *osd, u_int slot, void *value)
{
return (osd_set_reserved(type, osd, slot, NULL, value));
}
void **
osd_reserve(u_int slot)
{
KASSERT(slot > 0, ("Invalid slot."));
OSD_DEBUG("Reserving slot array (slot=%u).", slot);
return (malloc(sizeof(void *) * slot, M_OSD, M_WAITOK | M_ZERO));
}
int
osd_set_reserved(u_int type, struct osd *osd, u_int slot, void **rsv,
void *value)
{
struct rm_priotracker tracker;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
KASSERT(slot > 0, ("Invalid slot."));
KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
rm_rlock(&osdm[type].osd_object_lock, &tracker);
if (slot > osd->osd_nslots) {
void **newptr;
if (value == NULL) {
OSD_DEBUG(
"Not allocating null slot (type=%u, slot=%u).",
type, slot);
rm_runlock(&osdm[type].osd_object_lock, &tracker);
if (rsv)
osd_free_reserved(rsv);
return (0);
}
/*
* Too few slots allocated here, so we need to extend or create
* the array.
*/
if (rsv) {
/*
* Use the reserve passed in (assumed to be
* the right size).
*/
newptr = rsv;
if (osd->osd_nslots != 0) {
memcpy(newptr, osd->osd_slots,
sizeof(void *) * osd->osd_nslots);
free(osd->osd_slots, M_OSD);
}
} else {
newptr = realloc(osd->osd_slots, sizeof(void *) * slot,
M_OSD, M_NOWAIT | M_ZERO);
if (newptr == NULL) {
rm_runlock(&osdm[type].osd_object_lock,
&tracker);
return (ENOMEM);
}
}
if (osd->osd_nslots == 0) {
/*
* First OSD for this object, so we need to put it
* onto the list.
*/
mtx_lock(&osdm[type].osd_list_lock);
LIST_INSERT_HEAD(&osdm[type].osd_list, osd, osd_next);
mtx_unlock(&osdm[type].osd_list_lock);
OSD_DEBUG("Setting first slot (type=%u).", type);
} else
OSD_DEBUG("Growing slots array (type=%u).", type);
osd->osd_slots = newptr;
osd->osd_nslots = slot;
} else if (rsv)
osd_free_reserved(rsv);
OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type,
slot, value);
osd->osd_slots[slot - 1] = value;
rm_runlock(&osdm[type].osd_object_lock, &tracker);
return (0);
}
void
osd_free_reserved(void **rsv)
{
OSD_DEBUG("Discarding reserved slot array.");
free(rsv, M_OSD);
}
void *
osd_get(u_int type, struct osd *osd, u_int slot)
{
struct rm_priotracker tracker;
void *value;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
KASSERT(slot > 0, ("Invalid slot."));
KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
rm_rlock(&osdm[type].osd_object_lock, &tracker);
if (slot > osd->osd_nslots) {
value = NULL;
OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot);
} else {
value = osd->osd_slots[slot - 1];
OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).",
type, slot, value);
}
rm_runlock(&osdm[type].osd_object_lock, &tracker);
return (value);
}
void
osd_del(u_int type, struct osd *osd, u_int slot)
{
struct rm_priotracker tracker;
rm_rlock(&osdm[type].osd_object_lock, &tracker);
do_osd_del(type, osd, slot, 0);
rm_runlock(&osdm[type].osd_object_lock, &tracker);
}
static void
do_osd_del(u_int type, struct osd *osd, u_int slot, int list_locked)
{
int i;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
KASSERT(slot > 0, ("Invalid slot."));
KASSERT(osdm[type].osd_destructors[slot - 1] != NULL, ("Unused slot."));
OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot);
if (slot > osd->osd_nslots) {
OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot);
return;
}
if (osd->osd_slots[slot - 1] != NULL) {
osdm[type].osd_destructors[slot - 1](osd->osd_slots[slot - 1]);
osd->osd_slots[slot - 1] = NULL;
}
for (i = osd->osd_nslots - 1; i >= 0; i--) {
if (osd->osd_slots[i] != NULL) {
OSD_DEBUG("Slot still has a value (type=%u, slot=%u).",
type, i + 1);
break;
}
}
if (i == -1) {
/* No values left for this object. */
OSD_DEBUG("No more slots left (type=%u).", type);
if (!list_locked)
mtx_lock(&osdm[type].osd_list_lock);
LIST_REMOVE(osd, osd_next);
if (!list_locked)
mtx_unlock(&osdm[type].osd_list_lock);
free(osd->osd_slots, M_OSD);
osd->osd_slots = NULL;
osd->osd_nslots = 0;
} else if (slot == osd->osd_nslots) {
/* This was the last slot. */
osd->osd_slots = realloc(osd->osd_slots,
sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO);
/*
* We always reallocate to smaller size, so we assume it will
* always succeed.
*/
KASSERT(osd->osd_slots != NULL, ("realloc() failed"));
osd->osd_nslots = i + 1;
OSD_DEBUG("Reducing slots array to %u (type=%u).",
osd->osd_nslots, type);
}
}
int
osd_call(u_int type, u_int method, void *obj, void *data)
{
osd_method_t methodfun;
int error, i;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
KASSERT(method < osdm[type].osd_nmethods, ("Invalid method."));
/*
* Call this method for every slot that defines it, stopping if an
* error is encountered.
*/
error = 0;
sx_slock(&osdm[type].osd_module_lock);
for (i = 0; i < osdm[type].osd_ntslots; i++) {
methodfun = osdm[type].osd_methods[i * osdm[type].osd_nmethods +
method];
if (methodfun != NULL && (error = methodfun(obj, data)) != 0)
break;
}
sx_sunlock(&osdm[type].osd_module_lock);
return (error);
}
void
osd_exit(u_int type, struct osd *osd)
{
struct rm_priotracker tracker;
u_int i;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
if (osd->osd_nslots == 0) {
KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots."));
/* No OSD attached, just leave. */
return;
}
rm_rlock(&osdm[type].osd_object_lock, &tracker);
for (i = 1; i <= osd->osd_nslots; i++) {
if (osdm[type].osd_destructors[i - 1] != NULL)
do_osd_del(type, osd, i, 0);
else
OSD_DEBUG("Unused slot (type=%u, slot=%u).", type, i);
}
rm_runlock(&osdm[type].osd_object_lock, &tracker);
OSD_DEBUG("Object exit (type=%u).", type);
}
static void
osd_init(void *arg __unused)
{
u_int i;
for (i = OSD_FIRST; i <= OSD_LAST; i++) {
sx_init(&osdm[i].osd_module_lock, "osd_module");
rm_init(&osdm[i].osd_object_lock, "osd_object");
mtx_init(&osdm[i].osd_list_lock, "osd_list", NULL, MTX_DEF);
LIST_INIT(&osdm[i].osd_list);
osdm[i].osd_destructors = NULL;
osdm[i].osd_ntslots = 0;
osdm[i].osd_methods = NULL;
}
}
SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL);
