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 munmap(statp, npages * pagesize);
58 statp = NULL;
59 close (statsfd);
60 statsfd = -1;
61 }
62
63 void
geom_stats_resync(void)64 geom_stats_resync(void)
65 {
66 void *p;
67 off_t mediasize;
68 int error;
69
70 if (statsfd == -1)
71 return;
72 error = ioctl(statsfd, DIOCGMEDIASIZE, &mediasize);
73 if (error)
74 err(1, "DIOCGMEDIASIZE(" _PATH_DEV DEVSTAT_DEVICE_NAME ")");
75
76 munmap(statp, npages * pagesize);
77 p = mmap(statp, mediasize, PROT_READ, MAP_SHARED, statsfd, 0);
78 if (p == MAP_FAILED)
79 err(1, "mmap(/dev/devstat):");
80 else {
81 statp = p;
82 npages = mediasize / pagesize;
83 }
84 }
85
86 int
geom_stats_open(void)87 geom_stats_open(void)
88 {
89 int error;
90 void *p;
91
92 if (statsfd != -1)
93 return (EBUSY);
94 statsfd = open(_PATH_DEV DEVSTAT_DEVICE_NAME, O_RDONLY);
95 if (statsfd < 0)
96 return (errno);
97 pagesize = getpagesize();
98 spp = pagesize / sizeof(struct devstat);
99 p = mmap(NULL, pagesize, PROT_READ, MAP_SHARED, statsfd, 0);
100 if (p == MAP_FAILED) {
101 error = errno;
102 close(statsfd);
103 statsfd = -1;
104 errno = error;
105 return (error);
106 }
107 statp = p;
108 npages = 1;
109 geom_stats_resync();
110 return (0);
111 }
112
113 struct snapshot {
114 u_char *ptr;
115 uint pages;
116 uint pagesize;
117 uint perpage;
118 struct timespec time;
119 /* used by getnext: */
120 uint u, v;
121 };
122
123 void *
geom_stats_snapshot_get(void)124 geom_stats_snapshot_get(void)
125 {
126 struct snapshot *sp;
127
128 sp = malloc(sizeof *sp);
129 if (sp == NULL)
130 return (NULL);
131 memset(sp, 0, sizeof *sp);
132 sp->ptr = malloc(pagesize * npages);
133 if (sp->ptr == NULL) {
134 free(sp);
135 return (NULL);
136 }
137 explicit_bzero(sp->ptr, pagesize * npages); /* page in, cache */
138 clock_gettime(CLOCK_REALTIME, &sp->time);
139 memcpy(sp->ptr, statp, pagesize * npages);
140 sp->pages = npages;
141 sp->perpage = spp;
142 sp->pagesize = pagesize;
143 return (sp);
144 }
145
146 void
geom_stats_snapshot_free(void * arg)147 geom_stats_snapshot_free(void *arg)
148 {
149 struct snapshot *sp;
150
151 sp = arg;
152 free(sp->ptr);
153 free(sp);
154 }
155
156 void
geom_stats_snapshot_timestamp(void * arg,struct timespec * tp)157 geom_stats_snapshot_timestamp(void *arg, struct timespec *tp)
158 {
159 struct snapshot *sp;
160
161 sp = arg;
162 *tp = sp->time;
163 }
164
165 void
geom_stats_snapshot_reset(void * arg)166 geom_stats_snapshot_reset(void *arg)
167 {
168 struct snapshot *sp;
169
170 sp = arg;
171 sp->u = sp->v = 0;
172 }
173
174 struct devstat *
geom_stats_snapshot_next(void * arg)175 geom_stats_snapshot_next(void *arg)
176 {
177 struct devstat *gsp;
178 struct snapshot *sp;
179
180 sp = arg;
181 gsp = (struct devstat *)
182 (sp->ptr + sp->u * pagesize + sp->v * sizeof *gsp);
183 if (++sp->v >= sp->perpage) {
184 if (++sp->u >= sp->pages)
185 return (NULL);
186 else
187 sp->v = 0;
188 }
189 return (gsp);
190 }
191