crush: relax the order by which rules and buckets must be defined

Before we only allowed buckets (say, 'root') to be defined *before*
rules.

With this patch, we allow buckets and rules to be defined by any order,
although some care should be taken when creating the plain-text crush
map, or the crushtool will error out when a rule uses a bucket only
defined later on in the file.

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>

diff --git a/src/crush/grammar.h b/src/crush/grammar.h
index c975e176a894457e2cc5e3a6392228358d091ead..bb37fed428c85bff3e4781e334b9db1c9ebda646 100644 (file)
--- a/src/crush/grammar.h
+++ b/src/crush/grammar.h
@@ -138,7 +138,7 @@ struct crush_grammar : public grammar<crush_grammar>
                           >> '}';
 
       // the whole crush map
-      crushmap = *(tunable | device | bucket_type) >> *bucket >> *crushrule;
+      crushmap = *(tunable | device | bucket_type) >> *(bucket | crushrule);
     }
 
     rule<ScannerT, parser_context<>, parser_tag<_crushmap> > const&