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: releng/10.4/sys/geom/geom_kern.c 273736 2014-10-27 14:38:00Z hselasky $");
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/unistd.h>
48 #include <sys/kthread.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/sbuf.h>
52 #include <sys/sched.h>
53 #include <sys/sx.h>
54 #include <geom/geom.h>
55 #include <geom/geom_int.h>
56
57 MALLOC_DEFINE(M_GEOM, "GEOM", "Geom data structures");
58
59 struct sx topology_lock;
60
61 static struct proc *g_proc;
62 static struct thread *g_up_td;
63 static struct thread *g_down_td;
64 static struct thread *g_event_td;
65
66 int g_debugflags;
67 int g_collectstats = 1;
68 int g_shutdown;
69 int g_notaste;
70
71 /*
72 * G_UP and G_DOWN are the two threads which push I/O through the
73 * stack.
74 *
75 * Things are procesed in a FIFO order, but these threads could be
76 * part of I/O prioritization by deciding which bios/bioqs to service
77 * in what order.
78 *
79 * We have only one thread in each direction, it is belived that until
80 * a very non-trivial workload in the UP/DOWN path this will be enough,
81 * but more than one can actually be run without problems.
82 *
83 * Holding the "mymutex" is a debugging feature: It prevents people
84 * from sleeping in the UP/DOWN I/O path by mistake or design (doing
85 * so almost invariably result in deadlocks since it stalls all I/O
86 * processing in the given direction.
87 */
88
89 static void
90 g_up_procbody(void *arg)
91 {
92
93 mtx_assert(&Giant, MA_NOTOWNED);
94 thread_lock(g_up_td);
95 sched_prio(g_up_td, PRIBIO);
96 thread_unlock(g_up_td);
97 for(;;) {
98 g_io_schedule_up(g_up_td);
99 }
100 }
101
102 static void
103 g_down_procbody(void *arg)
104 {
105
106 mtx_assert(&Giant, MA_NOTOWNED);
107 thread_lock(g_down_td);
108 sched_prio(g_down_td, PRIBIO);
109 thread_unlock(g_down_td);
110 for(;;) {
111 g_io_schedule_down(g_down_td);
112 }
113 }
114
115 static void
116 g_event_procbody(void *arg)
117 {
118
119 mtx_assert(&Giant, MA_NOTOWNED);
120 thread_lock(g_event_td);
121 sched_prio(g_event_td, PRIBIO);
122 thread_unlock(g_event_td);
123 g_run_events();
124 /* NOTREACHED */
125 }
126
127 int
128 g_is_geom_thread(struct thread *td)
129 {
130
131 return (td == g_up_td || td == g_down_td || td == g_event_td);
132 }
133
134 static void
135 geom_shutdown(void *foo __unused)
136 {
137
138 g_shutdown = 1;
139 }
140
141 void
142 g_init(void)
143 {
144
145 g_trace(G_T_TOPOLOGY, "g_ignition");
146 sx_init(&topology_lock, "GEOM topology");
147 g_io_init();
148 g_event_init();
149 g_ctl_init();
150 mtx_lock(&Giant);
151 kproc_kthread_add(g_event_procbody, NULL, &g_proc, &g_event_td,
152 RFHIGHPID, 0, "geom", "g_event");
153 kproc_kthread_add(g_up_procbody, NULL, &g_proc, &g_up_td,
154 RFHIGHPID, 0, "geom", "g_up");
155 kproc_kthread_add(g_down_procbody, NULL, &g_proc, &g_down_td,
156 RFHIGHPID, 0, "geom", "g_down");
157 mtx_unlock(&Giant);
158 EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
159 SHUTDOWN_PRI_FIRST);
160 }
161
162 static int
163 sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
164 {
165 int error;
166 struct sbuf *sb;
167
168 sb = sbuf_new_auto();
169 g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL);
170 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
171 sbuf_delete(sb);
172 return error;
173 }
174
175 static int
176 sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
177 {
178 int error;
179 struct sbuf *sb;
180
181 sb = sbuf_new_auto();
182 g_waitfor_event(g_confdot, sb, M_WAITOK, NULL);
183 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
184 sbuf_delete(sb);
185 return error;
186 }
187
188 static int
189 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
190 {
191 int error;
192 struct sbuf *sb;
193
194 sb = sbuf_new_auto();
195 g_waitfor_event(g_confxml, sb, M_WAITOK, NULL);
196 error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
197 sbuf_delete(sb);
198 return error;
199 }
200
201 SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management");
202
203 SYSCTL_PROC(_kern_geom, OID_AUTO, confxml, CTLTYPE_STRING|CTLFLAG_RD,
204 0, 0, sysctl_kern_geom_confxml, "",
205 "Dump the GEOM config in XML");
206
207 SYSCTL_PROC(_kern_geom, OID_AUTO, confdot, CTLTYPE_STRING|CTLFLAG_RD,
208 0, 0, sysctl_kern_geom_confdot, "",
209 "Dump the GEOM config in dot");
210
211 SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt, CTLTYPE_STRING|CTLFLAG_RD,
212 0, 0, sysctl_kern_geom_conftxt, "",
213 "Dump the GEOM config in txt");
214
215 TUNABLE_INT("kern.geom.debugflags", &g_debugflags);
216 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RW,
217 &g_debugflags, 0, "Set various trace levels for GEOM debugging");
218
219 SYSCTL_INT(_kern_geom, OID_AUTO, notaste, CTLFLAG_RW,
220 &g_notaste, 0, "Prevent GEOM tasting");
221
222 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
223 &g_collectstats, 0,
224 "Control statistics collection on GEOM providers and consumers");
225
226 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
227 SYSCTL_NULL_INT_PTR, sizeof(struct g_class), "sizeof(struct g_class)");
228 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
229 SYSCTL_NULL_INT_PTR, sizeof(struct g_geom), "sizeof(struct g_geom)");
230 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
231 SYSCTL_NULL_INT_PTR, sizeof(struct g_provider), "sizeof(struct g_provider)");
232 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
233 SYSCTL_NULL_INT_PTR, sizeof(struct g_consumer), "sizeof(struct g_consumer)");
234 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
235 SYSCTL_NULL_INT_PTR, sizeof(struct g_bioq), "sizeof(struct g_bioq)");
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