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 1.42 2008/08/09 11:14:05 des 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/sbuf.h>
51 #include <sys/sched.h>
52 #include <sys/sx.h>
53 #include <geom/geom.h>
54 #include <geom/geom_int.h>
55
56 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
57
58 struct sx topology_lock;
59
60 static struct proc *g_up_proc;
61
62 int g_debugflags;
63 int g_collectstats = 1;
64 int g_shutdown;
65
66 /*
67 * G_UP and G_DOWN are the two threads which push I/O through the
68 * stack.
69 *
70 * Things are procesed in a FIFO order, but these threads could be
71 * part of I/O prioritization by deciding which bios/bioqs to service
72 * in what order.
73 *
74 * We have only one thread in each direction, it is belived that until
75 * a very non-trivial workload in the UP/DOWN path this will be enough,
76 * but more than one can actually be run without problems.
77 *
78 * Holding the "mymutex" is a debugging feature: It prevents people
79 * from sleeping in the UP/DOWN I/O path by mistake or design (doing
80 * so almost invariably result in deadlocks since it stalls all I/O
81 * processing in the given direction.
82 */
83
84 static void
85 g_up_procbody(void)
86 {
87 struct proc *p = g_up_proc;
88 struct thread *tp = FIRST_THREAD_IN_PROC(p);
89
90 mtx_assert(&Giant, MA_NOTOWNED);
91 thread_lock(tp);
92 sched_prio(tp, PRIBIO);
93 thread_unlock(tp);
94 for(;;) {
95 g_io_schedule_up(tp);
96 }
97 }
98
99 static struct kproc_desc g_up_kp = {
100 "g_up",
101 g_up_procbody,
102 &g_up_proc,
103 };
104
105 static struct proc *g_down_proc;
106
107 static void
108 g_down_procbody(void)
109 {
110 struct proc *p = g_down_proc;
111 struct thread *tp = FIRST_THREAD_IN_PROC(p);
112
113 mtx_assert(&Giant, MA_NOTOWNED);
114 thread_lock(tp);
115 sched_prio(tp, PRIBIO);
116 thread_unlock(tp);
117 for(;;) {
118 g_io_schedule_down(tp);
119 }
120 }
121
122 static struct kproc_desc g_down_kp = {
123 "g_down",
124 g_down_procbody,
125 &g_down_proc,
126 };
127
128 static struct proc *g_event_proc;
129
130 static void
131 g_event_procbody(void)
132 {
133 struct proc *p = g_event_proc;
134 struct thread *tp = FIRST_THREAD_IN_PROC(p);
135
136 mtx_assert(&Giant, MA_NOTOWNED);
137 thread_lock(tp);
138 sched_prio(tp, PRIBIO);
139 thread_unlock(tp);
140 for(;;) {
141 g_run_events();
142 tsleep(&g_wait_event, PRIBIO, "-", hz/10);
143 }
144 }
145
146 static struct kproc_desc g_event_kp = {
147 "g_event",
148 g_event_procbody,
149 &g_event_proc,
150 };
151
152 static void
153 geom_shutdown(void *foo __unused)
154 {
155
156 g_shutdown = 1;
157 }
158
159 void
160 g_init(void)
161 {
162
163 g_trace(G_T_TOPOLOGY, "g_ignition");
164 sx_init(&topology_lock, "GEOM topology");
165 g_io_init();
166 g_event_init();
167 g_ctl_init();
168 mtx_lock(&Giant);
169 kproc_start(&g_event_kp);
170 kproc_start(&g_up_kp);
171 kproc_start(&g_down_kp);
172 mtx_unlock(&Giant);
173 EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
174 SHUTDOWN_PRI_FIRST);
175 }
176
177 static int
178 sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
179 {
180 int error;
181 struct sbuf *sb;
182
183 sb = sbuf_new_auto();
184 g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL);
185 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
186 sbuf_delete(sb);
187 return error;
188 }
189
190 static int
191 sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
192 {
193 int error;
194 struct sbuf *sb;
195
196 sb = sbuf_new_auto();
197 g_waitfor_event(g_confdot, sb, M_WAITOK, NULL);
198 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
199 sbuf_delete(sb);
200 return error;
201 }
202
203 static int
204 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
205 {
206 int error;
207 struct sbuf *sb;
208
209 sb = sbuf_new_auto();
210 g_waitfor_event(g_confxml, sb, M_WAITOK, NULL);
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 TUNABLE_INT("kern.geom.debugflags", &g_debugflags);
231 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
232 &g_debugflags, 0, "Set various trace levels for GEOM debugging");
233
234 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
235 &g_collectstats, 0,
236 "Control statistics collection on GEOM providers and consumers");
237
238 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
239 0, sizeof(struct g_class), "sizeof(struct g_class)");
240 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
241 0, sizeof(struct g_geom), "sizeof(struct g_geom)");
242 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
243 0, sizeof(struct g_provider), "sizeof(struct g_provider)");
244 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
245 0, sizeof(struct g_consumer), "sizeof(struct g_consumer)");
246 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
247 0, sizeof(struct g_bioq), "sizeof(struct g_bioq)");
248
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