FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_kern.c
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: src/sys/geom/geom_kern.c,v 1.34.2.1 2004/09/28 18:16:51 pjd Exp $");
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 TUNABLE_INT("kern.geom.debugflags", &g_debugflags);
224 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
225 &g_debugflags, 0, "");
226
227 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
228 &g_collectstats, 0, "");
229
230 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
231 0, sizeof(struct g_class), "");
232 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
233 0, sizeof(struct g_geom), "");
234 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
235 0, sizeof(struct g_provider), "");
236 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
237 0, sizeof(struct g_consumer), "");
238 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
239 0, sizeof(struct g_bioq), "");
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