1/*-
2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7 * and NAI Labs, the Security Research Division of Network Associates, Inc.
8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9 * DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The names of the authors may not be used to endorse or promote
20 *    products derived from this software without specific prior written
21 *    permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD: releng/11.0/sys/geom/geom_kern.c 300289 2016-05-20 08:28:11Z kib $");
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/kernel.h>
42#include <sys/eventhandler.h>
43#include <sys/malloc.h>
44#include <sys/bio.h>
45#include <sys/sysctl.h>
46#include <sys/proc.h>
47#include <sys/unistd.h>
48#include <sys/kthread.h>
49#include <sys/lock.h>
50#include <sys/mutex.h>
51#include <sys/sbuf.h>
52#include <sys/sched.h>
53#include <sys/sx.h>
54#include <geom/geom.h>
55#include <geom/geom_int.h>
56
57MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
58
59struct sx topology_lock;
60
61static struct proc *g_proc;
62static struct thread *g_up_td;
63static struct thread *g_down_td;
64static struct thread *g_event_td;
65
66int g_debugflags;
67int g_collectstats = 1;
68int g_shutdown;
69int g_notaste;
70
71/*
72 * G_UP and G_DOWN are the two threads which push I/O through the
73 * stack.
74 *
75 * Things are procesed in a FIFO order, but these threads could be
76 * part of I/O prioritization by deciding which bios/bioqs to service
77 * in what order.
78 *
79 * We have only one thread in each direction, it is believed that until
80 * a very non-trivial workload in the UP/DOWN path this will be enough,
81 * but more than one can actually be run without problems.
82 *
83 * Holding the "mymutex" is a debugging feature:  It prevents people
84 * from sleeping in the UP/DOWN I/O path by mistake or design (doing
85 * so almost invariably result in deadlocks since it stalls all I/O
86 * processing in the given direction.
87 */
88
89static void
90g_up_procbody(void *arg)
91{
92
93	thread_lock(g_up_td);
94	sched_prio(g_up_td, PRIBIO);
95	thread_unlock(g_up_td);
96	for(;;) {
97		g_io_schedule_up(g_up_td);
98	}
99}
100
101static void
102g_down_procbody(void *arg)
103{
104
105	thread_lock(g_down_td);
106	sched_prio(g_down_td, PRIBIO);
107	thread_unlock(g_down_td);
108	for(;;) {
109		g_io_schedule_down(g_down_td);
110	}
111}
112
113static void
114g_event_procbody(void *arg)
115{
116
117	thread_lock(g_event_td);
118	sched_prio(g_event_td, PRIBIO);
119	thread_unlock(g_event_td);
120	g_run_events();
121	/* NOTREACHED */
122}
123
124int
125g_is_geom_thread(struct thread *td)
126{
127
128	return (td == g_up_td || td == g_down_td || td == g_event_td);
129}
130
131static void
132geom_shutdown(void *foo __unused)
133{
134
135	g_shutdown = 1;
136}
137
138void
139g_init(void)
140{
141
142	g_trace(G_T_TOPOLOGY, "g_ignition");
143	sx_init(&topology_lock, "GEOM topology");
144	g_io_init();
145	g_event_init();
146	g_ctl_init();
147	kproc_kthread_add(g_event_procbody, NULL, &g_proc, &g_event_td,
148	    RFHIGHPID, 0, "geom", "g_event");
149	kproc_kthread_add(g_up_procbody, NULL, &g_proc, &g_up_td,
150	    RFHIGHPID, 0, "geom", "g_up");
151	kproc_kthread_add(g_down_procbody, NULL, &g_proc, &g_down_td,
152	    RFHIGHPID, 0, "geom", "g_down");
153	EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
154		SHUTDOWN_PRI_FIRST);
155}
156
157static int
158sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
159{
160	int error;
161	struct sbuf *sb;
162
163	sb = sbuf_new_auto();
164	g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL);
165	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
166	sbuf_delete(sb);
167	return error;
168}
169
170static int
171sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
172{
173	int error;
174	struct sbuf *sb;
175
176	sb = sbuf_new_auto();
177	g_waitfor_event(g_confdot, sb, M_WAITOK, NULL);
178	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
179	sbuf_delete(sb);
180	return error;
181}
182
183static int
184sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
185{
186	int error;
187	struct sbuf *sb;
188
189	sb = sbuf_new_auto();
190	g_waitfor_event(g_confxml, sb, M_WAITOK, NULL);
191	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
192	sbuf_delete(sb);
193	return error;
194}
195
196SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
197
198SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
199	0, 0, sysctl_kern_geom_confxml, "",
200	"Dump the GEOM config in XML");
201
202SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
203	0, 0, sysctl_kern_geom_confdot, "",
204	"Dump the GEOM config in dot");
205
206SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD,
207	0, 0, sysctl_kern_geom_conftxt, "",
208	"Dump the GEOM config in txt");
209
210SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RWTUN,
211	&g_debugflags, 0, "Set various trace levels for GEOM debugging");
212
213SYSCTL_INT(_kern_geom, OID_AUTO, notaste, CTLFLAG_RW,
214	&g_notaste, 0, "Prevent GEOM tasting");
215
216SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
217	&g_collectstats, 0,
218	"Control statistics collection on GEOM providers and consumers");
219
220SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
221	SYSCTL_NULL_INT_PTR, sizeof(struct g_class), "sizeof(struct g_class)");
222SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
223	SYSCTL_NULL_INT_PTR, sizeof(struct g_geom), "sizeof(struct g_geom)");
224SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
225	SYSCTL_NULL_INT_PTR, sizeof(struct g_provider), "sizeof(struct g_provider)");
226SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
227	SYSCTL_NULL_INT_PTR, sizeof(struct g_consumer), "sizeof(struct g_consumer)");
228SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
229	SYSCTL_NULL_INT_PTR, sizeof(struct g_bioq), "sizeof(struct g_bioq)");
230