From 6a865f805b723525358ed8e79bb3d41709e98bf3 Mon Sep 17 00:00:00 2001
From: Mark Nelson <mnelson@redhat.com>
Date: Fri, 24 Jul 2020 05:29:15 +0000
Subject: [PATCH] mds/CInode: Optimize only pinned by subtrees check

Fixes: https://tracker.ceph.com/issues/46727

Signed-off-by: Mark Nelson <mnelson@redhat.com>
---
 src/mds/CInode.h   | 3 +++
 src/mds/MDCache.cc | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 1e055cf99f9db..60da4fb98765f 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -579,6 +579,9 @@ class CInode : public MDSCacheObject, public InodeStoreBase, public Counter<CIno
     get_subtree_dirfrags(v);
     return v;
   }
+  int get_num_subtree_roots() const {
+    return num_subtree_roots;
+  }
 
   CDir *get_or_open_dirfrag(MDCache *mdcache, frag_t fg);
   CDir *add_dirfrag(CDir *dir);
diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 6bbe7e8638eb3..ff877c150ca2e 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -6837,9 +6837,9 @@ std::pair<bool, uint64_t> MDCache::trim(uint64_t count)
       }
     } else if (!diri->is_auth() && dir->get_num_ref() <= 1) {
       // only subtree pin
-      auto&& ls = diri->get_subtree_dirfrags();
-      if (diri->get_num_ref() > (int)ls.size()) // only pinned by subtrees
+      if (diri->get_num_ref() > diri->get_num_subtree_roots()) {
         continue;
+      }
 
       // don't trim subtree root if its auth MDS is recovering.
       // This simplify the cache rejoin code.
-- 
2.39.5