1 /**
2 * collectd - src/md.c
3 * Copyright (C) 2010,2011 Michael Hanselmann
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Author:
19 * Michael Hanselmann
20 **/
22 #include "collectd.h"
24 #include "common.h"
25 #include "plugin.h"
26 #include "utils_ignorelist.h"
28 #include <sys/ioctl.h>
30 #include <linux/major.h>
31 #include <linux/raid/md_u.h>
33 #ifdef HAVE_SYS_SYSMACROS_H
34 #include <sys/sysmacros.h>
35 #endif
37 #define PROC_DISKSTATS "/proc/diskstats"
38 #define DEV_DIR "/dev"
40 static const char *config_keys[] =
41 {
42 "Device",
43 "IgnoreSelected"
44 };
45 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
47 static ignorelist_t *ignorelist = NULL;
49 static int md_config (const char *key, const char *value)
50 {
51 if (ignorelist == NULL)
52 ignorelist = ignorelist_create (/* invert = */ 1);
53 if (ignorelist == NULL)
54 return (1);
56 if (strcasecmp (key, "Device") == 0)
57 {
58 ignorelist_add (ignorelist, value);
59 }
60 else if (strcasecmp (key, "IgnoreSelected") == 0)
61 {
62 ignorelist_set_invert (ignorelist, IS_TRUE (value) ? 0 : 1);
63 }
64 else
65 {
66 return (-1);
67 }
69 return (0);
70 }
72 static void md_submit (const int minor, const char *type_instance,
73 gauge_t value)
74 {
75 value_t values[1];
76 value_list_t vl = VALUE_LIST_INIT;
78 values[0].gauge = value;
80 vl.values = values;
81 vl.values_len = 1;
82 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
83 sstrncpy (vl.plugin, "md", sizeof (vl.plugin));
84 ssnprintf (vl.plugin_instance, sizeof (vl.plugin_instance),
85 "%i", minor);
86 sstrncpy (vl.type, "md_disks", sizeof (vl.type));
87 sstrncpy (vl.type_instance, type_instance,
88 sizeof (vl.type_instance));
90 plugin_dispatch_values (&vl);
91 } /* void md_submit */
93 static void md_process (const int minor, const char *path)
94 {
95 char errbuf[1024];
96 int fd;
97 struct stat st;
98 mdu_array_info_t array;
99 gauge_t disks_missing;
101 fd = open (path, O_RDONLY);
102 if (fd < 0)
103 {
104 WARNING ("md: open(%s): %s", path,
105 sstrerror (errno, errbuf, sizeof (errbuf)));
106 return;
107 }
109 if (fstat (fd, &st) < 0)
110 {
111 WARNING ("md: Unable to fstat file descriptor for %s: %s", path,
112 sstrerror (errno, errbuf, sizeof (errbuf)));
113 close (fd);
114 return;
115 }
117 if (! S_ISBLK (st.st_mode))
118 {
119 WARNING ("md: %s is no block device", path);
120 close (fd);
121 return;
122 }
124 if (st.st_rdev != makedev (MD_MAJOR, minor))
125 {
126 WARNING ("md: Major/minor of %s are %i:%i, should be %i:%i",
127 path, (int)major(st.st_rdev), (int)minor(st.st_rdev),
128 (int)MD_MAJOR, minor);
129 close (fd);
130 return;
131 }
133 /* Retrieve md information */
134 if (ioctl (fd, GET_ARRAY_INFO, &array) < 0) {
135 WARNING ("md: Unable to retrieve array info from %s: %s", path,
136 sstrerror (errno, errbuf, sizeof (errbuf)));
137 close (fd);
138 return;
139 }
141 close (fd);
143 /*
144 * The mdu_array_info_t structure contains numbers of disks in the array.
145 * However, disks are accounted for more than once:
146 *
147 * active: Number of active (in sync) disks.
148 * spare: Number of stand-by disks.
149 * working: Number of working disks. (active + sync)
150 * failed: Number of failed disks.
151 * nr: Number of physically present disks. (working + failed)
152 * raid: Number of disks in the RAID. This may be larger than "nr" if
153 * disks are missing and smaller than "nr" when spare disks are
154 * around.
155 */
156 md_submit (minor, "active", (gauge_t) array.active_disks);
157 md_submit (minor, "failed", (gauge_t) array.failed_disks);
158 md_submit (minor, "spare", (gauge_t) array.spare_disks);
160 disks_missing = 0.0;
161 if (array.raid_disks > array.nr_disks)
162 disks_missing = (gauge_t) (array.raid_disks - array.nr_disks);
163 md_submit (minor, "missing", disks_missing);
164 } /* void md_process */
166 static int md_read (void)
167 {
168 FILE *fh;
169 char buffer[1024];
171 fh = fopen (PROC_DISKSTATS, "r");
172 if (fh == NULL) {
173 char errbuf[1024];
174 WARNING ("md: Unable to open %s: %s",
175 PROC_DISKSTATS ,
176 sstrerror (errno, errbuf, sizeof (errbuf)));
177 return (-1);
178 }
180 /* Iterate md devices */
181 while (fgets (buffer, sizeof (buffer), fh) != NULL)
182 {
183 char path[PATH_MAX];
184 char *fields[4];
185 char *name;
186 int major, minor;
188 /* Extract interesting fields */
189 if (strsplit (buffer, fields, STATIC_ARRAY_SIZE(fields)) < 3)
190 continue;
192 major = atoi (fields[0]);
194 if (major != MD_MAJOR)
195 continue;
197 minor = atoi (fields[1]);
198 name = fields[2];
200 if (ignorelist_match (ignorelist, name))
201 continue;
203 /* FIXME: Don't hardcode path. Walk /dev collecting major,
204 * minor and name, then use lookup table to find device.
205 * Alternatively create a temporary device file with correct
206 * major/minor, but that again can be tricky if the filesystem
207 * with the device file is mounted using the "nodev" option.
208 */
209 ssnprintf (path, sizeof (path), "%s/%s", DEV_DIR, name);
211 md_process (minor, path);
212 }
214 fclose (fh);
216 return (0);
217 } /* int md_read */
219 void module_register (void)
220 {
221 plugin_register_config ("md", md_config, config_keys, config_keys_num);
222 plugin_register_read ("md", md_read);
223 } /* void module_register */