xref: /freebsd/sys/geom/geom_kern.c (revision 886d1942e8b127c969daf32921087878aa5bac94)
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 	mtx_assert(&Giant, MA_NOTOWNED);
87 	bzero(&mymutex, sizeof mymutex);
88 	mtx_init(&mymutex, "g_up", MTX_DEF, 0);
89 	mtx_lock(&mymutex);
90 	tp->td_base_pri = PRIBIO;
91 	for(;;) {
92 		g_io_schedule_up(tp);
93 		msleep(&g_wait_up, &mymutex, PRIBIO, "g_up", hz/10);
94 	}
95 }
96 
97 struct kproc_desc g_up_kp = {
98 	"g_up",
99 	g_up_procbody,
100 	&g_up_proc,
101 };
102 
103 static struct proc *g_down_proc;
104 
105 static void
106 g_down_procbody(void)
107 {
108 	struct proc *p = g_down_proc;
109 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
110 	struct mtx mymutex;
111 
112 	mtx_assert(&Giant, MA_NOTOWNED);
113 	bzero(&mymutex, sizeof mymutex);
114 	mtx_init(&mymutex, "g_down", MTX_DEF, 0);
115 	mtx_lock(&mymutex);
116 	tp->td_base_pri = PRIBIO;
117 	for(;;) {
118 		g_io_schedule_down(tp);
119 		msleep(&g_wait_down, &mymutex, PRIBIO, "g_down", hz/10);
120 	}
121 }
122 
123 struct kproc_desc g_down_kp = {
124 	"g_down",
125 	g_down_procbody,
126 	&g_down_proc,
127 };
128 
129 static struct proc *g_event_proc;
130 
131 static void
132 g_event_procbody(void)
133 {
134 	struct proc *p = g_event_proc;
135 	struct thread *tp = FIRST_THREAD_IN_PROC(p);
136 
137 	mtx_assert(&Giant, MA_NOTOWNED);
138 	tp->td_base_pri = PRIBIO;
139 	for(;;) {
140 		g_run_events();
141 		tsleep(&g_wait_event, PRIBIO, "g_events", hz/10);
142 	}
143 }
144 
145 struct kproc_desc g_event_kp = {
146 	"g_event",
147 	g_event_procbody,
148 	&g_event_proc,
149 };
150 
151 void
152 g_init(void)
153 {
154 	printf("Initializing GEOMetry subsystem\n");
155 	sx_init(&topology_lock, "GEOM topology");
156 	g_io_init();
157 	g_event_init();
158 	mtx_lock(&Giant);
159 	kproc_start(&g_event_kp);
160 	kproc_start(&g_up_kp);
161 	kproc_start(&g_down_kp);
162 	mtx_unlock(&Giant);
163 }
164 
165 static int
166 sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
167 {
168 	int error;
169 	struct sbuf *sb;
170 
171 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
172 	sbuf_clear(sb);
173 	g_call_me(g_conftxt, sb);
174 	do {
175 		tsleep(sb, PZERO, "g_conftxt", hz);
176 	} while(!sbuf_done(sb));
177 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
178 	sbuf_delete(sb);
179 	return error;
180 }
181 
182 static int
183 sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
184 {
185 	int error;
186 	struct sbuf *sb;
187 
188 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
189 	sbuf_clear(sb);
190 	g_call_me(g_confdot, sb);
191 	do {
192 		tsleep(sb, PZERO, "g_confdot", hz);
193 	} while(!sbuf_done(sb));
194 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
195 	sbuf_delete(sb);
196 	return error;
197 }
198 
199 static int
200 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
201 {
202 	int error;
203 	struct sbuf *sb;
204 
205 	sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
206 	sbuf_clear(sb);
207 	g_call_me(g_confxml, sb);
208 	do {
209 		tsleep(sb, PZERO, "g_confxml", hz);
210 	} while(!sbuf_done(sb));
211 	error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
212 	sbuf_delete(sb);
213 	return error;
214 }
215 
216 SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
217 
218 SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
219 	0, 0, sysctl_kern_geom_confxml, "",
220 	"Dump the GEOM config in XML");
221 
222 SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
223 	0, 0, sysctl_kern_geom_confdot, "",
224 	"Dump the GEOM config in dot");
225 
226 SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD,
227 	0, 0, sysctl_kern_geom_conftxt, "",
228 	"Dump the GEOM config in txt");
229 
230 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
231 	&g_debugflags, 0, "");
232 
233 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
234 	0, sizeof(struct g_class), "");
235 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
236 	0, sizeof(struct g_geom), "");
237 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
238 	0, sizeof(struct g_provider), "");
239 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
240 	0, sizeof(struct g_consumer), "");
241 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
242 	0, sizeof(struct g_bioq), "");
243 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_event, CTLFLAG_RD,
244 	0, sizeof(struct g_event), "");
245