1 /*-
2 * Copyright (c) 2003 Poul-Henning Kamp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The names of the authors may not be used to endorse or promote
14 * products derived from this software without specific prior written
15 * permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD$
30 */
31
32 #include <paths.h>
33 #include <errno.h>
34 #include <fcntl.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <libgeom.h>
39
40 #include <sys/mman.h>
41 #include <sys/time.h>
42 #include <sys/types.h>
43 #include <sys/devicestat.h>
44
45
46 /************************************************************/
47 static uint npages, pagesize, spp;
48 static int statsfd = -1;
49 static u_char *statp;
50
51 void
geom_stats_close(void)52 geom_stats_close(void)
53 {
54 if (statsfd == -1)
55 return;
56 munmap(statp, npages *pagesize);
57 statp = NULL;
58 close (statsfd);
59 statsfd = -1;
60 }
61
62 void
geom_stats_resync(void)63 geom_stats_resync(void)
64 {
65 void *p;
66
67 if (statsfd == -1)
68 return;
69 for (;;) {
70 p = mmap(statp, (npages + 1) * pagesize,
71 PROT_READ, MAP_SHARED, statsfd, 0);
72 if (p == MAP_FAILED)
73 break;
74 else
75 statp = p;
76 npages++;
77 }
78 }
79
80 int
geom_stats_open(void)81 geom_stats_open(void)
82 {
83 int error;
84 void *p;
85
86 if (statsfd != -1)
87 return (EBUSY);
88 statsfd = open(_PATH_DEV DEVSTAT_DEVICE_NAME, O_RDONLY);
89 if (statsfd < 0)
90 return (errno);
91 pagesize = getpagesize();
92 spp = pagesize / sizeof(struct devstat);
93 p = mmap(NULL, pagesize, PROT_READ, MAP_SHARED, statsfd, 0);
94 if (p == MAP_FAILED) {
95 error = errno;
96 close(statsfd);
97 statsfd = -1;
98 errno = error;
99 return (error);
100 }
101 statp = p;
102 npages = 1;
103 geom_stats_resync();
104 return (0);
105 }
106
107 struct snapshot {
108 u_char *ptr;
109 uint pages;
110 uint pagesize;
111 uint perpage;
112 struct timespec time;
113 /* used by getnext: */
114 uint u, v;
115 };
116
117 void *
geom_stats_snapshot_get(void)118 geom_stats_snapshot_get(void)
119 {
120 struct snapshot *sp;
121
122 sp = malloc(sizeof *sp);
123 if (sp == NULL)
124 return (NULL);
125 memset(sp, 0, sizeof *sp);
126 sp->ptr = malloc(pagesize * npages);
127 if (sp->ptr == NULL) {
128 free(sp);
129 return (NULL);
130 }
131 memset(sp->ptr, 0, pagesize * npages); /* page in, cache */
132 clock_gettime(CLOCK_REALTIME, &sp->time);
133 memset(sp->ptr, 0, pagesize * npages); /* page in, cache */
134 memcpy(sp->ptr, statp, pagesize * npages);
135 sp->pages = npages;
136 sp->perpage = spp;
137 sp->pagesize = pagesize;
138 return (sp);
139 }
140
141 void
geom_stats_snapshot_free(void * arg)142 geom_stats_snapshot_free(void *arg)
143 {
144 struct snapshot *sp;
145
146 sp = arg;
147 free(sp->ptr);
148 free(sp);
149 }
150
151 void
geom_stats_snapshot_timestamp(void * arg,struct timespec * tp)152 geom_stats_snapshot_timestamp(void *arg, struct timespec *tp)
153 {
154 struct snapshot *sp;
155
156 sp = arg;
157 *tp = sp->time;
158 }
159
160 void
geom_stats_snapshot_reset(void * arg)161 geom_stats_snapshot_reset(void *arg)
162 {
163 struct snapshot *sp;
164
165 sp = arg;
166 sp->u = sp->v = 0;
167 }
168
169 struct devstat *
geom_stats_snapshot_next(void * arg)170 geom_stats_snapshot_next(void *arg)
171 {
172 struct devstat *gsp;
173 struct snapshot *sp;
174
175 sp = arg;
176 gsp = (struct devstat *)
177 (sp->ptr + sp->u * pagesize + sp->v * sizeof *gsp);
178 if (++sp->v >= sp->perpage) {
179 if (++sp->u >= sp->pages)
180 return (NULL);
181 else
182 sp->v = 0;
183 }
184 return (gsp);
185 }
186