xref: /freebsd/sys/geom/geom_kern.c (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
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/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 
57 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
58 
59 struct sx topology_lock;
60 
61 static struct proc *g_proc;
62 static struct thread *g_up_td;
63 static struct thread *g_down_td;
64 static struct thread *g_event_td;
65 
66 int g_debugflags;
67 int g_collectstats = 1;
68 int g_shutdown;
69 int 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 
89 static void
90 g_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 
101 static void
102 g_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 
113 static void
114 g_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 
124 int
125 g_is_geom_thread(struct thread *td)
126 {
127 
128 	return (td == g_up_td || td == g_down_td || td == g_event_td);
129 }
130 
131 static void
132 geom_shutdown(void *foo __unused)
133 {
134 
135 	g_shutdown = 1;
136 }
137 
138 void
139 g_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 
157 static int
158 sysctl_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 
170 static int
171 sysctl_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 
183 static int
184 sysctl_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 
196 SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
197 
198 SYSCTL_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 
202 SYSCTL_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 
206 SYSCTL_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 
210 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RWTUN,
211 	&g_debugflags, 0, "Set various trace levels for GEOM debugging");
212 
213 SYSCTL_INT(_kern_geom, OID_AUTO, notaste, CTLFLAG_RW,
214 	&g_notaste, 0, "Prevent GEOM tasting");
215 
216 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
217 	&g_collectstats, 0,
218 	"Control statistics collection on GEOM providers and consumers");
219 
220 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
221 	SYSCTL_NULL_INT_PTR, sizeof(struct g_class), "sizeof(struct g_class)");
222 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
223 	SYSCTL_NULL_INT_PTR, sizeof(struct g_geom), "sizeof(struct g_geom)");
224 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
225 	SYSCTL_NULL_INT_PTR, sizeof(struct g_provider), "sizeof(struct g_provider)");
226 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
227 	SYSCTL_NULL_INT_PTR, sizeof(struct g_consumer), "sizeof(struct g_consumer)");
228 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
229 	SYSCTL_NULL_INT_PTR, sizeof(struct g_bioq), "sizeof(struct g_bioq)");
230