From 6fe1ea0dd58b087ceb88e3f3ca552a9f721b86ac Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Fri, 26 Oct 2018 12:40:32 -0500
Subject: [PATCH] crushtool: implement --rebuild-class-roots command

This simply rebuilds the class roots.  Normally this should create no
change in the map since whatever was making changes to the map before
should have rebuild the shadow roots at that point.

Signed-off-by: Sage Weil <sage@redhat.com>
---
 src/test/cli/crushtool/help.t |  2 ++
 src/tools/crushtool.cc        | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/test/cli/crushtool/help.t b/src/test/cli/crushtool/help.t
index 4b2e056c89ba..77460bd2c68e 100644
--- a/src/test/cli/crushtool/help.t
+++ b/src/test/cli/crushtool/help.t
@@ -63,6 +63,8 @@
      -i mapfn --move       name --loc type name ...
                            move the given item to specified location
      -i mapfn --reweight   recalculate all bucket weights
+     -i mapfn --rebuild-class-roots
+                           rebuild the per-class shadow trees (normally a no-op)
      -i mapfn --create-simple-rule name root type mode
                            create crush rule <name> to start from <root>,
                            replicate across buckets of type <type>, using
diff --git a/src/tools/crushtool.cc b/src/tools/crushtool.cc
index d6a01864ec69..918b341b5d9a 100644
--- a/src/tools/crushtool.cc
+++ b/src/tools/crushtool.cc
@@ -171,6 +171,8 @@ void usage()
   cout << "   -i mapfn --move       name --loc type name ...\n"
        << "                         move the given item to specified location\n";
   cout << "   -i mapfn --reweight   recalculate all bucket weights\n";
+  cout << "   -i mapfn --rebuild-class-roots\n";
+  cout << "                         rebuild the per-class shadow trees (normally a no-op)\n";
   cout << "   -i mapfn --create-simple-rule name root type mode\n"
        << "                         create crush rule <name> to start from <root>,\n"
        << "                         replicate across buckets of type <type>, using\n"
@@ -388,6 +390,8 @@ int main(int argc, const char **argv)
   int verbose = 0;
   bool unsafe_tunables = false;
 
+  bool rebuild_class_roots = false;
+
   bool reweight = false;
   int add_item = -1;
   bool add_bucket = false;
@@ -552,6 +556,8 @@ int main(int argc, const char **argv)
       adjust = true;
     } else if (ceph_argparse_flag(args, i, "--reweight", (char*)NULL)) {
       reweight = true;
+    } else if (ceph_argparse_flag(args, i, "--rebuild-class-roots", (char*)NULL)) {
+      rebuild_class_roots = true;
     } else if (ceph_argparse_witharg(args, i, &add_item, err, "--add_item", (char*)NULL)) {
       if (!err.str().empty()) {
 	cerr << err.str() << std::endl;
@@ -821,7 +827,7 @@ int main(int argc, const char **argv)
   }
   if (!check && !compile && !decompile && !build && !test && !reweight && !adjust && !tree && !dump &&
       add_item < 0 && !add_bucket && !move_item && !add_rule && !del_rule && full_location < 0 &&
-      !reclassify &&
+      !reclassify && !rebuild_class_roots &&
       compare.empty() &&
       remove_name.empty() && reweight_name.empty()) {
     cerr << "no action specified; -h for help" << std::endl;
@@ -1164,6 +1170,14 @@ int main(int argc, const char **argv)
     crush.reweight(g_ceph_context);
     modified = true;
   }
+  if (rebuild_class_roots) {
+    int r = crush.rebuild_roots_with_classes();
+    if (r < 0) {
+      cerr << "failed to rebuidl roots with classes" << std::endl;
+      return EXIT_FAILURE;
+    }
+    modified = true;
+  }
 
   for (auto& i : set_subtree_class) {
     crush.set_subtree_class(i.first, i.second);
-- 
2.47.3