FreeBSD-5.3/sys/geom/geom_kern.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: src/sys/geom/geom_kern.c,v 1.34.2.1 2004/09/28 18:16:51 pjd Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/eventhandler.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>
#include <sys/sx.h>
#include <sys/sbuf.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
struct sx topology_lock;
static struct proc *g_up_proc;
int g_debugflags;
int g_collectstats = 1;
int g_shutdown;
/*
* G_UP and G_DOWN are the two threads which push I/O through the
* stack.
*
* Things are procesed in a FIFO order, but these threads could be
* part of I/O prioritization by deciding which bios/bioqs to service
* in what order.
*
* We have only one thread in each direction, it is belived that until
* a very non-trivial workload in the UP/DOWN path this will be enough,
* but more than one can actually be run without problems.
*
* Holding the "mymutex" is a debugging feature: It prevents people
* from sleeping in the UP/DOWN I/O path by mistake or design (doing
* so almost invariably result in deadlocks since it stalls all I/O
* processing in the given direction.
*/
static void
g_up_procbody(void)
{
struct proc *p = g_up_proc;
struct thread *tp = FIRST_THREAD_IN_PROC(p);
mtx_assert(&Giant, MA_NOTOWNED);
tp->td_base_pri = PRIBIO;
for(;;) {
g_io_schedule_up(tp);
}
}
struct kproc_desc g_up_kp = {
"g_up",
g_up_procbody,
&g_up_proc,
};
static struct proc *g_down_proc;
static void
g_down_procbody(void)
{
struct proc *p = g_down_proc;
struct thread *tp = FIRST_THREAD_IN_PROC(p);
mtx_assert(&Giant, MA_NOTOWNED);
tp->td_base_pri = PRIBIO;
for(;;) {
g_io_schedule_down(tp);
}
}
struct kproc_desc g_down_kp = {
"g_down",
g_down_procbody,
&g_down_proc,
};
static struct proc *g_event_proc;
static void
g_event_procbody(void)
{
struct proc *p = g_event_proc;
struct thread *tp = FIRST_THREAD_IN_PROC(p);
mtx_assert(&Giant, MA_NOTOWNED);
tp->td_base_pri = PRIBIO;
for(;;) {
g_run_events();
tsleep(&g_wait_event, PRIBIO, "-", hz/10);
}
}
static struct kproc_desc g_event_kp = {
"g_event",
g_event_procbody,
&g_event_proc,
};
static void
geom_shutdown(void *foo __unused)
{
g_shutdown = 1;
}
void
g_init(void)
{
g_trace(G_T_TOPOLOGY, "g_ignition");
sx_init(&topology_lock, "GEOM topology");
g_io_init();
g_event_init();
g_ctl_init();
mtx_lock(&Giant);
kproc_start(&g_event_kp);
kproc_start(&g_up_kp);
kproc_start(&g_down_kp);
mtx_unlock(&Giant);
EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
SHUTDOWN_PRI_FIRST);
}
static int
sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
{
int error;
struct sbuf *sb;
sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
sbuf_delete(sb);
return error;
}
static int
sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
{
int error;
struct sbuf *sb;
sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
g_waitfor_event(g_confdot, sb, M_WAITOK, NULL);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
sbuf_delete(sb);
return error;
}
static int
sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
{
int error;
struct sbuf *sb;
sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
g_waitfor_event(g_confxml, sb, M_WAITOK, NULL);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
sbuf_delete(sb);
return error;
}
SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_kern_geom_confxml, "",
"Dump the GEOM config in XML");
SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_kern_geom_confdot, "",
"Dump the GEOM config in dot");
SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD,
0, 0, sysctl_kern_geom_conftxt, "",
"Dump the GEOM config in txt");
TUNABLE_INT("kern.geom.debugflags", &g_debugflags);
SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
&g_debugflags, 0, "");
SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
&g_collectstats, 0, "");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
0, sizeof(struct g_class), "");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
0, sizeof(struct g_geom), "");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
0, sizeof(struct g_provider), "");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
0, sizeof(struct g_consumer), "");
SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
0, sizeof(struct g_bioq), "");