From: Mark Nelson <mnelson@redhat.com>
Date: Fri, 24 Jul 2020 05:29:15 +0000 (+0000)
Subject: mds/CInode: Optimize only pinned by subtrees check
X-Git-Tag: v14.2.12~14^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=04736d688d772897d1b0315917db9d8751f21bed;p=ceph.git

mds/CInode: Optimize only pinned by subtrees check

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

Signed-off-by: Mark Nelson <mnelson@redhat.com>
(cherry picked from commit 6a865f805b723525358ed8e79bb3d41709e98bf3)

Conflicts:
	src/mds/MDCache.cc
	  - use the nautilus code flow of trim instead master
---

diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 6809d52fc5e2..cbe8779a2018 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -600,6 +600,9 @@ public:
         ls.push_back(dir);
     }
   }
+  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 f771ca545562..629e53abb274 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -6706,9 +6706,7 @@ std::pair<bool, uint64_t> MDCache::trim(uint64_t count)
       if (!diri->is_auth()) {
 	if (dir->get_num_ref() > 1)  // only subtree pin
 	  continue;
-	list<CDir*> ls;
-	diri->get_subtree_dirfrags(ls);
-	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.