Split off OpenBSD code into a separate implementation

Move OpenBSD code into its own sysdeps directory. The changes from
bsd/ were becoming to hard to maintain as a #ifdef tree. This is
what's currently being distributed as part of OpenBSD ports.

sysdeps/openbsd/fsusage.c

@@ -0,0 +1,58 @@
+/* $OpenBSD: fsusage.c,v 1.3 2011/05/23 19:35:53 jasper Exp $	*/
+
+#include <config.h>
+
+#undef HAVE_SYS_STATVFS_H
+#undef STAT_STATVFS
+
+#include <glibtop.h>
+#include <glibtop/error.h>
+#include <glibtop/fsusage.h>
+
+#include <glibtop_suid.h>
+
+#include <glib.h>
+
+#include <unistd.h>
+#include <sys/param.h>
+#if defined (HAVE_SYS_STATVFS_H)
+#include <sys/statvfs.h>
+#else
+#include <sys/mount.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+void
+_glibtop_bsd_get_fsusage_read_write(glibtop *server,
+				      glibtop_fsusage *buf,
+				      const char *path);
+
+void
+_glibtop_bsd_get_fsusage_read_write(glibtop *server,
+				      glibtop_fsusage *buf,
+				      const char *path)
+{
+	int result;
+#if defined (STAT_STATVFS)
+	struct statvfs sfs;
+#else
+	struct statfs sfs;
+#endif
+
+#if defined (STAT_STATVFS)
+	result = statvfs (path, &sfs);
+#else
+	result = statfs (path, &sfs);
+#endif
+
+	if (result == -1) {
+		return;
+	}
+
+	buf->read = sfs.f_syncreads + sfs.f_asyncreads;
+	buf->write = sfs.f_syncwrites + sfs.f_asyncwrites;
+	buf->flags |= (1 << GLIBTOP_FSUSAGE_READ) | (1 << GLIBTOP_FSUSAGE_WRITE);
+}