xref: /freebsd/sys/geom/geom_kern.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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("$FreeBSD$");
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/kthread.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/sx.h>
51 #include <sys/sbuf.h>
52 #include <geom/geom.h>
53 #include <geom/geom_int.h>
54 
55 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
56 
57 struct sx topology_lock;
58 
59 static struct proc *g_up_proc;
60 
61 int g_debugflags;
62 int g_collectstats = 1;
63 int g_shutdown;
64 
65 /*
66  * G_UP and G_DOWN are the two threads which push I/O through the
67  * stack.
68  *
69  * Things are procesed in a FIFO order, but these threads could be
70  * part of I/O prioritization by deciding which bios/bioqs to service
71  * in what order.
72  *
73  * We have only one thread in each direction, it is belived that until
74  * a very non-trivial workload in the UP/DOWN path this will be enough,
75  * but more than one can actually be run without problems.
76  *
77  * Holding the "mymutex" is a debugging feature:  It prevents people
78  * from sleeping in the UP/DOWN I/O path by mistake or design (doing
79  * so almost invariably result in deadlocks since it stalls all I/O
80  * processing in the given direction.
81  */
82 
83 static void
84 g_up_procbody(void)
85 {
86 	struct proc *p = g_up_proc;
87 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
88 
89 	mtx_assert(&Giant, MA_NOTOWNED);
90 	tp->td_base_pri = PRIBIO;
91 	for(;;) {
92 		g_io_schedule_up(tp);
93 	}
94 }
95 
96 struct kproc_desc g_up_kp = {
97 	"g_up",
98 	g_up_procbody,
99 	&g_up_proc,
100 };
101 
102 static struct proc *g_down_proc;
103 
104 static void
105 g_down_procbody(void)
106 {
107 	struct proc *p = g_down_proc;
108 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
109 
110 	mtx_assert(&Giant, MA_NOTOWNED);
111 	tp->td_base_pri = PRIBIO;
112 	for(;;) {
113 		g_io_schedule_down(tp);
114 	}
115 }
116 
117 struct kproc_desc g_down_kp = {
118 	"g_down",
119 	g_down_procbody,
120 	&g_down_proc,
121 };
122 
123 static struct proc *g_event_proc;
124 
125 static void
126 g_event_procbody(void)
127 {
128 	struct proc *p = g_event_proc;
129 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
130 
131 	mtx_assert(&Giant, MA_NOTOWNED);
132 	tp->td_base_pri = PRIBIO;
133 	for(;;) {
134 		g_run_events();
135 		tsleep(&g_wait_event, PRIBIO, "-", hz/10);
136 	}
137 }
138 
139 static struct kproc_desc g_event_kp = {
140 	"g_event",
141 	g_event_procbody,
142 	&g_event_proc,
143 };
144 
145 static void
146 geom_shutdown(void *foo __unused)
147 {
148 
149 	g_shutdown = 1;
150 }
151 
152 void
153 g_init(void)
154 {
155 
156 	g_trace(G_T_TOPOLOGY, "g_ignition");
157 	sx_init(&topology_lock, "GEOM topology");
158 	g_io_init();
159 	g_event_init();
160 	g_ctl_init();
161 	mtx_lock(&Giant);
162 	kproc_start(&g_event_kp);
163 	kproc_start(&g_up_kp);
164 	kproc_start(&g_down_kp);
165 	mtx_unlock(&Giant);
166 	EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
167 		SHUTDOWN_PRI_FIRST);
168 }
169 
170 static int
171 sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
172 {
173 	int error;
174 	struct sbuf *sb;
175 
176 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
177 	g_waitfor_event(g_conftxt, 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 
183 static int
184 sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
185 {
186 	int error;
187 	struct sbuf *sb;
188 
189 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
190 	g_waitfor_event(g_confdot, 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 
196 static int
197 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
198 {
199 	int error;
200 	struct sbuf *sb;
201 
202 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
203 	g_waitfor_event(g_confxml, sb, M_WAITOK, NULL);
204 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
205 	sbuf_delete(sb);
206 	return error;
207 }
208 
209 SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
210 
211 SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
212 	0, 0, sysctl_kern_geom_confxml, "",
213 	"Dump the GEOM config in XML");
214 
215 SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
216 	0, 0, sysctl_kern_geom_confdot, "",
217 	"Dump the GEOM config in dot");
218 
219 SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD,
220 	0, 0, sysctl_kern_geom_conftxt, "",
221 	"Dump the GEOM config in txt");
222 
223 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
224 	&g_debugflags, 0, "");
225 
226 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
227 	&g_collectstats, 0, "");
228 
229 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
230 	0, sizeof(struct g_class), "");
231 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
232 	0, sizeof(struct g_geom), "");
233 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
234 	0, sizeof(struct g_provider), "");
235 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
236 	0, sizeof(struct g_consumer), "");
237 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
238 	0, sizeof(struct g_bioq), "");
239