libvirt plugin: Correctly check the status code of virDomainGetVcpus().

The status code is less than zero on failure and the number of vCPUs
otherwise. Thanks to "JLPC" for pointing this problem out.

diff --git a/src/libvirt.c b/src/libvirt.c
index bcbf0e6..91fda7a 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -295,21 +295,31 @@ lv_read (void)
     for (i = 0; i < nr_domains; ++i) {
         virDomainInfo info;
         virVcpuInfoPtr vinfo = NULL;
+        int status;
         int j;
 
-        if (virDomainGetInfo (domains[i], &info) != 0)
+        status = virDomainGetInfo (domains[i], &info);
+        if (status != 0)
+        {
+            ERROR ("libvirt plugin: virDomainGetInfo failed with status %i.",
+                    status);
             continue;
+        }
 
         cpu_submit (info.cpuTime, t, domains[i], "virt_cpu_total");
 
-        vinfo = malloc (info.nrVirtCpu * sizeof vinfo[0]);
+        vinfo = malloc (info.nrVirtCpu * sizeof (vinfo[0]));
         if (vinfo == NULL) {
             ERROR ("libvirt plugin: malloc failed.");
             continue;
         }
 
-        if (virDomainGetVcpus (domains[i], vinfo, info.nrVirtCpu,
-                    NULL, 0) != 0) {
+        status = virDomainGetVcpus (domains[i], vinfo, info.nrVirtCpu,
+                /* cpu map = */ NULL, /* cpu map length = */ 0);
+        if (status < 0)
+        {
+            ERROR ("libvirt plugin: virDomainGetVcpus failed with status %i.",
+                    status);
             free (vinfo);
             continue;
         }