xref: /freebsd/sys/geom/geom_kern.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2002 Poul-Henning Kamp
5  * Copyright (c) 2002 Networks Associates Technology, Inc.
6  * All rights reserved.
7  *
8  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
9  * and NAI Labs, the Security Research Division of Network Associates, Inc.
10  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
11  * DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The names of the authors may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
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/unistd.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_proc;
61 struct thread __read_mostly *g_up_td;
62 struct thread __read_mostly *g_down_td;
63 static struct thread __read_mostly *g_event_td;
64 
65 int __read_mostly g_debugflags;
66 int __read_mostly g_collectstats = G_STATS_PROVIDERS;
67 int g_shutdown;
68 int g_notaste;
69 
70 /*
71  * G_UP and G_DOWN are the two threads which push I/O through the
72  * stack.
73  *
74  * Things are procesed in a FIFO order, but these threads could be
75  * part of I/O prioritization by deciding which bios/bioqs to service
76  * in what order.
77  *
78  * We have only one thread in each direction, it is believed that until
79  * a very non-trivial workload in the UP/DOWN path this will be enough,
80  * but more than one can actually be run without problems.
81  *
82  * Holding the "mymutex" is a debugging feature:  It prevents people
83  * from sleeping in the UP/DOWN I/O path by mistake or design (doing
84  * so almost invariably result in deadlocks since it stalls all I/O
85  * processing in the given direction.
86  */
87 
88 static void
89 g_up_procbody(void *arg)
90 {
91 
92 	thread_lock(g_up_td);
93 	sched_prio(g_up_td, PRIBIO);
94 	thread_unlock(g_up_td);
95 	for(;;) {
96 		g_io_schedule_up(g_up_td);
97 	}
98 }
99 
100 static void
101 g_down_procbody(void *arg)
102 {
103 
104 	thread_lock(g_down_td);
105 	sched_prio(g_down_td, PRIBIO);
106 	thread_unlock(g_down_td);
107 	for(;;) {
108 		g_io_schedule_down(g_down_td);
109 	}
110 }
111 
112 static void
113 g_event_procbody(void *arg)
114 {
115 
116 	thread_lock(g_event_td);
117 	sched_prio(g_event_td, PRIBIO);
118 	thread_unlock(g_event_td);
119 	g_run_events();
120 	/* NOTREACHED */
121 }
122 
123 int
124 g_is_geom_thread(struct thread *td)
125 {
126 
127 	return (td == g_up_td || td == g_down_td || td == g_event_td);
128 }
129 
130 static void
131 geom_shutdown(void *foo __unused)
132 {
133 
134 	g_shutdown = 1;
135 }
136 
137 void
138 g_init(void)
139 {
140 
141 	g_trace(G_T_TOPOLOGY, "g_ignition");
142 	sx_init(&topology_lock, "GEOM topology");
143 	g_io_init();
144 	g_event_init();
145 	g_ctl_init();
146 	kproc_kthread_add(g_event_procbody, NULL, &g_proc, &g_event_td,
147 	    RFHIGHPID, 0, "geom", "g_event");
148 	kproc_kthread_add(g_up_procbody, NULL, &g_proc, &g_up_td,
149 	    RFHIGHPID, 0, "geom", "g_up");
150 	kproc_kthread_add(g_down_procbody, NULL, &g_proc, &g_down_td,
151 	    RFHIGHPID, 0, "geom", "g_down");
152 	EVENTHANDLER_REGISTER(shutdown_pre_sync, geom_shutdown, NULL,
153 		SHUTDOWN_PRI_FIRST);
154 }
155 
156 static int
157 sysctl_kern_geom_confany(struct sysctl_req *req, g_event_t *func, size_t *hint)
158 {
159 	size_t len = 0;
160 	int error = 0;
161 	struct sbuf *sb;
162 
163 	if (req->oldptr == NULL) {
164 		sb = sbuf_new(NULL, NULL, PAGE_SIZE, SBUF_FIXEDLEN |
165 		    SBUF_INCLUDENUL);
166 		sbuf_set_drain(sb, sbuf_count_drain, &len);
167 		g_waitfor_event(func, sb, M_WAITOK, NULL);
168 		req->oldidx = *hint = len;
169 	} else {
170 		sb = sbuf_new(NULL, NULL, *hint, SBUF_AUTOEXTEND |
171 		    SBUF_INCLUDENUL);
172 		g_waitfor_event(func, sb, M_WAITOK, NULL);
173 		*hint = sbuf_len(sb);
174 		error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb));
175 	}
176 	sbuf_delete(sb);
177 	return error;
178 }
179 
180 static int
181 sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS)
182 {
183 	static size_t hint = PAGE_SIZE;
184 
185 	return (sysctl_kern_geom_confany(req, g_conftxt, &hint));
186 }
187 
188 static int
189 sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS)
190 {
191 	static size_t hint = PAGE_SIZE;
192 
193 	return (sysctl_kern_geom_confany(req, g_confdot, &hint));
194 }
195 
196 static int
197 sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS)
198 {
199 	static size_t hint = PAGE_SIZE;
200 
201 	return (sysctl_kern_geom_confany(req, g_confxml, &hint));
202 }
203 
204 SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
205     "GEOMetry management");
206 
207 SYSCTL_PROC(_kern_geom, OID_AUTO, confxml,
208     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
209     sysctl_kern_geom_confxml, "",
210     "Dump the GEOM config in XML");
211 
212 SYSCTL_PROC(_kern_geom, OID_AUTO, confdot,
213     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
214     sysctl_kern_geom_confdot, "",
215     "Dump the GEOM config in dot");
216 
217 SYSCTL_PROC(_kern_geom, OID_AUTO, conftxt,
218     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
219     sysctl_kern_geom_conftxt, "",
220     "Dump the GEOM config in txt");
221 
222 SYSCTL_INT(_kern_geom, OID_AUTO, debugflags, CTLFLAG_RWTUN,
223 	&g_debugflags, 0, "Set various trace levels for GEOM debugging");
224 
225 SYSCTL_INT(_kern_geom, OID_AUTO, notaste, CTLFLAG_RW,
226 	&g_notaste, 0, "Prevent GEOM tasting");
227 
228 SYSCTL_INT(_kern_geom, OID_AUTO, collectstats, CTLFLAG_RW,
229 	&g_collectstats, 0,
230 	"Control statistics collection on GEOM providers and consumers");
231 
232 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_class, CTLFLAG_RD,
233 	SYSCTL_NULL_INT_PTR, sizeof(struct g_class), "sizeof(struct g_class)");
234 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_geom, CTLFLAG_RD,
235 	SYSCTL_NULL_INT_PTR, sizeof(struct g_geom), "sizeof(struct g_geom)");
236 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_provider, CTLFLAG_RD,
237 	SYSCTL_NULL_INT_PTR, sizeof(struct g_provider), "sizeof(struct g_provider)");
238 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_consumer, CTLFLAG_RD,
239 	SYSCTL_NULL_INT_PTR, sizeof(struct g_consumer), "sizeof(struct g_consumer)");
240 SYSCTL_INT(_debug_sizeof, OID_AUTO, g_bioq, CTLFLAG_RD,
241 	SYSCTL_NULL_INT_PTR, sizeof(struct g_bioq), "sizeof(struct g_bioq)");
242