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 * $FreeBSD: releng/5.1/sys/geom/geom_kern.c 114293 2003-04-30 12:57:40Z markm $
36 */
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/eventhandler.h>
42 #include <sys/malloc.h>
43 #include <sys/bio.h>
44 #include <sys/sysctl.h>
45 #include <sys/proc.h>
46 #include <sys/kthread.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/sx.h>
50 #include <sys/sbuf.h>
51 #include <geom/geom.h>
52 #include <geom/geom_int.h>
53
54 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
55
56 struct sx topology_lock;
57
58 static struct proc *g_up_proc;
59
60 int g_debugflags;
61 int g_collectstats = 1;
62 int g_shutdown;
63
64 /*
65 * G_UP and G_DOWN are the two threads which push I/O through the
66 * stack.
67 *
68 * Things are procesed in a FIFO order, but these threads could be
69 * part of I/O prioritization by deciding which bios/bioqs to service
70 * in what order.
71 *
72 * We have only one thread in each direction, it is belived that until
73 * a very non-trivial workload in the UP/DOWN path this will be enough,
74 * but more than one can actually be run without problems.
75 *
76 * Holding the "mymutex" is a debugging feature: It prevents people
77 * from sleeping in the UP/DOWN I/O path by mistake or design (doing
78 * so almost invariably result in deadlocks since it stalls all I/O
79 * processing in the given direction.
80 */
81
82 static void
83 g_up_procbody(void)
84 {
85 struct proc *p = g_up_proc;
86 struct thread *tp = FIRST_THREAD_IN_PROC(p);
87
88 mtx_assert(&Giant, MA_NOTOWNED);
89 tp->td_base_pri = PRIBIO;
90 for(;;) {
91 g_io_schedule_up(tp);
92 }
93 }
94
95 struct kproc_desc g_up_kp = {
96 "g_up",
97 g_up_procbody,
98 &g_up_proc,
99 };
100
101 static struct proc *g_down_proc;
102
103 static void
104 g_down_procbody(void)
105 {
106 struct proc *p = g_down_proc;
107 struct thread *tp = FIRST_THREAD_IN_PROC(p);
108
109 mtx_assert(&Giant, MA_NOTOWNED);
110 tp->td_base_pri = PRIBIO;
111 for(;;) {
112 g_io_schedule_down(tp);
113 }
114 }
115
116 struct kproc_desc g_down_kp = {
117 "g_down",
118 g_down_procbody,
119 &g_down_proc,
120 };
121
122 static struct proc *g_event_proc;
123
124 static void
125 g_event_procbody(void)
126 {
127 struct proc *p = g_event_proc;
128 struct thread *tp = FIRST_THREAD_IN_PROC(p);
129
130 mtx_assert(&Giant, MA_NOTOWNED);
131 tp->td_base_pri = PRIBIO;
132 for(;;) {
133 g_run_events();
134 tsleep(&g_wait_event, PRIBIO, "g_events", hz/10);
135 }
136 }
137
138 static struct kproc_desc g_event_kp = {
139 "g_event",
140 g_event_procbody,
141 &g_event_proc,
142 };
143
144 static void
145 geom_shutdown(void *foo __unused)
146 {
147
148 g_shutdown = 1;
149 }
150
151 void
152 g_init(void)
153 {
154 sx_init(&topology_lock, "GEOM topology");
155 g_io_init();
156 g_event_init();
157 g_ctl_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 EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
164 SHUTDOWN_PRI_FIRST);
165 }
166
167 static int
168 sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
169 {
170 int error;
171 struct sbuf *sb;
172
173 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
174 sbuf_clear(sb);
175 g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL);
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_confdot(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_waitfor_event(g_confdot, sb, M_WAITOK, NULL);
190 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
191 sbuf_delete(sb);
192 return error;
193 }
194
195 static int
196 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
197 {
198 int error;
199 struct sbuf *sb;
200
201 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
202 sbuf_clear(sb);
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 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
224 &g_debugflags, 0, "");
225
226 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
227 &g_collectstats, 0, "");
228
229 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
230 0, sizeof(struct g_class), "");
231 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
232 0, sizeof(struct g_geom), "");
233 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
234 0, sizeof(struct g_provider), "");
235 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
236 0, sizeof(struct g_consumer), "");
237 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
238 0, sizeof(struct g_bioq), "");
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