xref: /freebsd/sys/geom/geom_kern.c (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
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  * $FreeBSD$
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/bio.h>
43 #include <sys/sysctl.h>
44 #include <sys/proc.h>
45 #include <sys/kthread.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/sx.h>
49 #include <sys/sbuf.h>
50 #include <geom/geom.h>
51 #include <geom/geom_int.h>
52 
53 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
54 
55 struct sx topology_lock;
56 
57 static struct proc *g_up_proc;
58 
59 int g_debugflags;
60 
61 /*
62  * G_UP and G_DOWN are the two threads which push I/O through the
63  * stack.
64  *
65  * Things are procesed in a FIFO order, but these threads could be
66  * part of I/O prioritization by deciding which bios/bioqs to service
67  * in what order.
68  *
69  * We have only one thread in each direction, it is belived that until
70  * a very non-trivial workload in the UP/DOWN path this will be enough,
71  * but more than one can actually be run without problems.
72  *
73  * Holding the "mymutex" is a debugging feature:  It prevents people
74  * from sleeping in the UP/DOWN I/O path by mistake or design (doing
75  * so almost invariably result in deadlocks since it stalls all I/O
76  * processing in the given direction.
77  */
78 
79 static void
80 g_up_procbody(void)
81 {
82 	struct proc *p = g_up_proc;
83 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
84 	struct mtx mymutex;
85 
86 	bzero(&mymutex, sizeof mymutex);
87 	mtx_init(&mymutex, "g_up", MTX_DEF, 0);
88 	mtx_lock(&mymutex);
89 	tp->td_base_pri = PRIBIO;
90 	for(;;) {
91 		g_io_schedule_up(tp);
92 		msleep(&g_wait_up, &mymutex, PRIBIO, "g_up", hz/10);
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 	struct mtx mymutex;
110 
111 	bzero(&mymutex, sizeof mymutex);
112 	mtx_init(&mymutex, "g_down", MTX_DEF, 0);
113 	mtx_lock(&mymutex);
114 	tp->td_base_pri = PRIBIO;
115 	for(;;) {
116 		g_io_schedule_down(tp);
117 		msleep(&g_wait_down, &mymutex, PRIBIO, "g_down", hz/10);
118 	}
119 }
120 
121 struct kproc_desc g_down_kp = {
122 	"g_down",
123 	g_down_procbody,
124 	&g_down_proc,
125 };
126 
127 static struct proc *g_event_proc;
128 
129 static void
130 g_event_procbody(void)
131 {
132 	struct proc *p = g_down_proc;
133 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
134 
135 	tp->td_base_pri = PRIBIO;
136 	for(;;) {
137 		g_run_events();
138 		tsleep(&g_wait_event, PRIBIO, "g_events", hz/10);
139 	}
140 }
141 
142 struct kproc_desc g_event_kp = {
143 	"g_event",
144 	g_event_procbody,
145 	&g_event_proc,
146 };
147 
148 void
149 g_init(void)
150 {
151 	printf("Initializing GEOMetry subsystem\n");
152 	if (bootverbose)
153 		g_debugflags |= G_T_TOPOLOGY;
154 	sx_init(&topology_lock, "GEOM topology");
155 	g_io_init();
156 	g_event_init();
157 	mtx_lock(&Giant);
158 	kproc_start(&g_event_kp);
159 	kproc_start(&g_up_kp);
160 	kproc_start(&g_down_kp);
161 	mtx_unlock(&Giant);
162 }
163 
164 static int
165 sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
166 {
167 	int error;
168 	struct sbuf *sb;
169 
170 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
171 	sbuf_clear(sb);
172 	g_call_me(g_confdot, sb);
173 	do {
174 		tsleep(sb, PZERO, "g_dot", hz);
175 	} while(!sbuf_done(sb));
176 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
177 	sbuf_delete(sb);
178 	return error;
179 }
180 
181 static int
182 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
183 {
184 	int error;
185 	struct sbuf *sb;
186 
187 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
188 	sbuf_clear(sb);
189 	g_call_me(g_confxml, sb);
190 	do {
191 		tsleep(sb, PZERO, "g_xml", hz);
192 	} while(!sbuf_done(sb));
193 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
194 	sbuf_delete(sb);
195 	return error;
196 }
197 
198 SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
199 
200 SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
201 	0, 0, sysctl_kern_geom_confxml, "A",
202 	"Dump the GEOM config");
203 
204 SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
205 	0, 0, sysctl_kern_geom_confdot, "A",
206 	"Dump the GEOM config");
207 
208 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
209 	&g_debugflags, 0, "");
210 
211 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
212 	0, sizeof(struct g_class), "");
213 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
214 	0, sizeof(struct g_geom), "");
215 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
216 	0, sizeof(struct g_provider), "");
217 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
218 	0, sizeof(struct g_consumer), "");
219 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
220 	0, sizeof(struct g_bioq), "");
221 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_event, CTLFLAG_RD,
222 	0, sizeof(struct g_event), "");
223