Plugin for Linux Software-RAID devices

[collectd.git] / src / md.c

diff --git a/src/md.c b/src/md.c
new file mode 100644 (file)
index 0000000..fdac4e3
--- /dev/null
+++ b/src/md.c
@@ -0,0 +1,204 @@
+/**
+ * collectd - src/md.c
+ * Copyright (C) 2010,2011  Michael Hanselmann
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Author:
+ *   Michael Hanselmann
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"
+#include "utils_ignorelist.h"
+
+#include <sys/ioctl.h>
+
+#include <linux/major.h>
+#include <linux/raid/md_u.h>
+
+#define PROC_DISKSTATS "/proc/diskstats"
+#define DEV_DIR "/dev"
+
+static const char *config_keys[] =
+{
+  "Device",
+  "IgnoreSelected"
+};
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
+
+static ignorelist_t *ignorelist = NULL;
+
+static int md_config (const char *key, const char *value)
+{
+  if (ignorelist == NULL)
+    ignorelist = ignorelist_create (/* invert = */ 1);
+  if (ignorelist == NULL)
+    return (1);
+
+  if (strcasecmp (key, "Device") == 0)
+  {
+    ignorelist_add (ignorelist, value);
+  }
+  else if (strcasecmp (key, "IgnoreSelected") == 0)
+  {
+    ignorelist_set_invert (ignorelist, IS_TRUE (value) ? 0 : 1);
+  }
+  else
+  {
+    return (-1);
+  }
+
+  return (0);
+}
+
+static void md_submit (const int minor, const char *type_instance,
+    gauge_t value)
+{
+  value_t values[1];
+  value_list_t vl = VALUE_LIST_INIT;
+
+  values[0].gauge = value;
+
+  vl.values = values;
+  vl.values_len = 1;
+  sstrncpy (vl.host, hostname_g, sizeof (vl.host));
+  sstrncpy (vl.plugin, "md", sizeof (vl.plugin));
+  ssnprintf (vl.plugin_instance, sizeof (vl.plugin_instance),
+      "%i", minor);
+  sstrncpy (vl.type, "md_disks", sizeof (vl.type));
+  sstrncpy (vl.type_instance, type_instance,
+      sizeof (vl.type_instance));
+
+  plugin_dispatch_values (&vl);
+} /* void md_submit */
+
+static void md_process (const int minor, const char *path)
+{
+  char errbuf[1024];
+  int fd;
+  struct stat st;
+  mdu_array_info_t array;
+
+  fd = open (path, O_RDONLY);
+  if (fd < 0)
+  {
+    WARNING ("md: open(%s): %s", path,
+        sstrerror (errno, errbuf, sizeof (errbuf)));
+    return;
+  }
+
+  if (fstat (fd, &st) < 0)
+  {
+    WARNING ("md: Unable to fstat file descriptor for %s: %s", path,
+        sstrerror (errno, errbuf, sizeof (errbuf)));
+    close (fd);
+    return;
+  }
+
+  if (! S_ISBLK (st.st_mode))
+  {
+    WARNING ("md: %s is no block device", path);
+    close (fd);
+    return;
+  }
+
+  if (st.st_rdev != makedev (MD_MAJOR, minor))
+  {
+    WARNING ("md: Major/minor of %s are %i:%i, should be %i:%i",
+        path, (int)major(st.st_rdev), (int)minor(st.st_rdev),
+        (int)MD_MAJOR, minor);
+    close (fd);
+    return;
+  }
+
+  /* Retrieve md information */
+  if (ioctl (fd, GET_ARRAY_INFO, &array) < 0) {
+    WARNING ("md: Unable to retrieve array info from %s: %s", path,
+        sstrerror (errno, errbuf, sizeof (errbuf)));
+    close (fd);
+    return;
+  }
+
+  close (fd);
+
+  md_submit (minor, "number",  (gauge_t) array.nr_disks);
+  md_submit (minor, "raid",    (gauge_t) array.raid_disks);
+  md_submit (minor, "active",  (gauge_t) array.active_disks);
+  md_submit (minor, "working", (gauge_t) array.working_disks);
+  md_submit (minor, "failed",  (gauge_t) array.failed_disks);
+  md_submit (minor, "spare",   (gauge_t) array.spare_disks);
+
+  return;
+} /* void md_process */
+
+static int md_read (void)
+{
+  FILE *fh;
+  char buffer[1024];
+
+  fh = fopen (PROC_DISKSTATS, "r");
+  if (fh == NULL) {
+    char errbuf[1024];
+    WARNING ("md: Unable to open %s: %s",
+        PROC_DISKSTATS ,
+        sstrerror (errno, errbuf, sizeof (errbuf)));
+    return (-1);
+  }
+
+  /* Iterate md devices */
+  while (fgets (buffer, sizeof (buffer), fh) != NULL)
+  {
+    char path[PATH_MAX];
+    char *fields[4];
+    char *name;
+    int major, minor;
+
+    /* Extract interesting fields */
+    if (strsplit (buffer, fields, STATIC_ARRAY_SIZE(fields)) < 3)
+      continue;
+
+    major = atoi (fields[0]);
+
+    if (major != MD_MAJOR)
+      continue;
+
+    minor = atoi (fields[1]);
+    name = fields[2];
+
+    if (ignorelist_match (ignorelist, name))
+      continue;
+
+    /* FIXME: Don't hardcode path. Walk /dev collecting major,
+     * minor and name, then use lookup table to find device.
+     * Alternatively create a temporary device file with correct
+     * major/minor, but that again can be tricky if the filesystem
+     * with the device file is mounted using the "nodev" option.
+     */
+    ssnprintf (path, sizeof (path), "%s/%s", DEV_DIR, name);
+
+    md_process (minor, path);
+  }
+
+  fclose (fh);
+
+  return (0);
+} /* int md_read */
+
+void module_register (void)
+{
+  plugin_register_config ("md", md_config, config_keys, config_keys_num);
+  plugin_register_read ("md", md_read);
+} /* void module_register */