1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2003 Poul-Henning Kamp
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The names of the authors may not be used to endorse or promote
16 * products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/types.h>
33 #include <sys/ioctl.h>
34 #include <sys/disk.h>
35 #include <sys/devicestat.h>
36 #include <sys/mman.h>
37 #include <sys/time.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <paths.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <libgeom.h>
46
47 /************************************************************/
48 static uint npages, spp;
49 static int pagesize, statsfd = -1;
50 static u_char *statp;
51
52 void
geom_stats_close(void)53 geom_stats_close(void)
54 {
55 if (statsfd == -1)
56 return;
57 if (statp != NULL) {
58 if (munmap(statp, npages * pagesize) != 0)
59 err(1, "munmap");
60 statp = NULL;
61 }
62 close(statsfd);
63 statsfd = -1;
64 }
65
66 void
geom_stats_resync(void)67 geom_stats_resync(void)
68 {
69 void *p;
70 off_t mediasize;
71 int error;
72
73 if (statsfd == -1)
74 return;
75 error = ioctl(statsfd, DIOCGMEDIASIZE, &mediasize);
76 if (error)
77 err(1, "DIOCGMEDIASIZE(" _PATH_DEV DEVSTAT_DEVICE_NAME ")");
78
79 if (statp != NULL && munmap(statp, npages * pagesize) != 0)
80 err(1, "munmap");
81 p = mmap(NULL, mediasize, PROT_READ, MAP_SHARED, statsfd, 0);
82 if (p == MAP_FAILED)
83 err(1, "mmap(/dev/devstat)");
84 statp = p;
85 npages = mediasize / pagesize;
86 }
87
88 int
geom_stats_open(void)89 geom_stats_open(void)
90 {
91 if (statsfd != -1)
92 return (EBUSY);
93 statsfd = open(_PATH_DEV DEVSTAT_DEVICE_NAME, O_RDONLY);
94 if (statsfd < 0)
95 return (errno);
96 pagesize = getpagesize();
97 spp = pagesize / sizeof(struct devstat);
98 npages = 1;
99 geom_stats_resync();
100 return (0);
101 }
102
103 struct snapshot {
104 u_char *ptr;
105 uint pages;
106 uint pagesize;
107 uint perpage;
108 struct timespec time;
109 /* used by getnext: */
110 uint u, v;
111 };
112
113 void *
geom_stats_snapshot_get(void)114 geom_stats_snapshot_get(void)
115 {
116 struct snapshot *sp;
117
118 sp = malloc(sizeof *sp);
119 if (sp == NULL)
120 return (NULL);
121 memset(sp, 0, sizeof *sp);
122 sp->ptr = malloc(pagesize * npages);
123 if (sp->ptr == NULL) {
124 free(sp);
125 return (NULL);
126 }
127 explicit_bzero(sp->ptr, pagesize * npages); /* page in, cache */
128 clock_gettime(CLOCK_REALTIME, &sp->time);
129 memcpy(sp->ptr, statp, pagesize * npages);
130 sp->pages = npages;
131 sp->perpage = spp;
132 sp->pagesize = pagesize;
133 return (sp);
134 }
135
136 void
geom_stats_snapshot_free(void * arg)137 geom_stats_snapshot_free(void *arg)
138 {
139 struct snapshot *sp;
140
141 sp = arg;
142 free(sp->ptr);
143 free(sp);
144 }
145
146 void
geom_stats_snapshot_timestamp(void * arg,struct timespec * tp)147 geom_stats_snapshot_timestamp(void *arg, struct timespec *tp)
148 {
149 struct snapshot *sp;
150
151 sp = arg;
152 *tp = sp->time;
153 }
154
155 void
geom_stats_snapshot_reset(void * arg)156 geom_stats_snapshot_reset(void *arg)
157 {
158 struct snapshot *sp;
159
160 sp = arg;
161 sp->u = sp->v = 0;
162 }
163
164 struct devstat *
geom_stats_snapshot_next(void * arg)165 geom_stats_snapshot_next(void *arg)
166 {
167 struct devstat *gsp;
168 struct snapshot *sp;
169
170 sp = arg;
171 gsp = (struct devstat *)
172 (sp->ptr + sp->u * pagesize + sp->v * sizeof *gsp);
173 if (++sp->v >= sp->perpage) {
174 if (++sp->u >= sp->pages)
175 return (NULL);
176 else
177 sp->v = 0;
178 }
179 return (gsp);
180 }
181