SF #1442767, docs for os.statvfs miss f_bsize parameter.  Will backport.
diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex
index 60a831c..9af5889 100644
--- a/Doc/lib/libos.tex
+++ b/Doc/lib/libos.tex
@@ -1097,6 +1097,7 @@
 return value is an object whose attributes describe the filesystem on
 the given path, and correspond to the members of the
 \ctype{statvfs} structure, namely:
+\member{f_bsize},
 \member{f_frsize},
 \member{f_blocks},
 \member{f_bfree},