Fix check_disk reporting OK if disk usage grows over 100% (bug #1348746).

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1848 f882894a-f735-0410-b71e-b25c423dba1c

NEWS

@@ -13,6 +13,8 @@ This file documents the major additions and syntax changes between releases.
 	Merge two new checks that deprecates check_ntp: check_ntp_peer and check_ntp_time.
 	  You should read the --help output so see which one is suitable for you. check_ntp_peer
 	  implement stratum thresholds support (feature request #1703823).
+	Fix check_disk reporting OK if disk usage grows over 100% (bug #1348746).
+	  The problem happens to be in Gnulib but a workaround have been implemented in check_disk.c
 
 1.4.10 28th September 2007
 	Fix check_http buffer overflow vulnerability when following HTTP redirects

plugins/check_disk.c

@@ -307,10 +307,17 @@ main (int argc, char **argv)
 
     if (fsp.fsu_blocks && strcmp ("none", me->me_mountdir)) {
       total = fsp.fsu_blocks;
-      available = fsp.fsu_bavail;
+      /* 2007-12-08 - Workaround for Gnulib reporting insanely high available
+       * space on BSD (the actual value should be negative but fsp.fsu_bavail
+       * is unsigned) */
+      available = fsp.fsu_bavail > fsp.fsu_bfree ? 0 : fsp.fsu_bavail;
       available_to_root = fsp.fsu_bfree;
       used = total - available_to_root;
 
+      if (verbose >= 3)
+        printf ("For %s, total=%llu, available=%llu, available_to_root=%llu, used=%llu, fsp.fsu_files=%llu, fsp.fsu_ffree=%llu\n",
+        me->me_mountdir, total, available, available_to_root, used, fsp.fsu_files, fsp.fsu_ffree);
+
       dused_pct = calculate_percent( used, used + available );	/* used + available can never be > uintmax */
      
       dfree_pct = 100 - dused_pct;