From 45e78bbeb2d6ff010c15e02939b6b5d70a22c40b Mon Sep 17 00:00:00 2001
From: Mark Kogan <mkogan@redhat.com>
Date: Tue, 12 Dec 2017 10:34:05 -0500
Subject: [PATCH] rgw: fix chained cache invalidation to prevent cache size
 growth above the rgw_cache_lru_size limit

Signed-off-by: Mark Kogan <mkogan@redhat.com>
---
 src/rgw/rgw_cache.cc | 20 ++++++++++++++------
 src/rgw/rgw_cache.h  |  1 +
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/rgw/rgw_cache.cc b/src/rgw/rgw_cache.cc
index be941e139576c8..67c8d834aba18b 100644
--- a/src/rgw/rgw_cache.cc
+++ b/src/rgw/rgw_cache.cc
@@ -135,11 +135,7 @@ void ObjectCache::put(string& name, ObjectCacheInfo& info, rgw_cache_entry_info
   ObjectCacheEntry& entry = iter->second;
   ObjectCacheInfo& target = entry.info;
 
-  for (list<pair<RGWChainedCache *, string> >::iterator iiter = entry.chained_entries.begin();
-       iiter != entry.chained_entries.end(); ++iiter) {
-    RGWChainedCache *chained_cache = iiter->first;
-    chained_cache->invalidate(iiter->second);
-  }
+  invalidate_lru(entry);
 
   entry.chained_entries.clear();
   entry.gen++;
@@ -230,8 +226,11 @@ void ObjectCache::touch_lru(string& name, ObjectCacheEntry& entry, std::list<str
     }
     map<string, ObjectCacheEntry>::iterator map_iter = cache_map.find(*iter);
     ldout(cct, 10) << "removing entry: name=" << *iter << " from cache LRU" << dendl;
-    if (map_iter != cache_map.end())
+    if (map_iter != cache_map.end()) {
+      ObjectCacheEntry& entry = map_iter->second;
+      invalidate_lru(entry);
       cache_map.erase(map_iter);
+    }
     lru.pop_front();
     lru_size--;
   }
@@ -263,6 +262,15 @@ void ObjectCache::remove_lru(string& name, std::list<string>::iterator& lru_iter
   lru_iter = lru.end();
 }
 
+void ObjectCache::invalidate_lru(ObjectCacheEntry& entry)
+{
+  for (list<pair<RGWChainedCache *, string> >::iterator iter = entry.chained_entries.begin();
+       iter != entry.chained_entries.end(); ++iter) {
+    RGWChainedCache *chained_cache = iter->first;
+    chained_cache->invalidate(iter->second);
+  }
+}
+
 void ObjectCache::set_enabled(bool status)
 {
   RWLock::WLocker l(lock);
diff --git a/src/rgw/rgw_cache.h b/src/rgw/rgw_cache.h
index 215f1445abfec4..4c7c1adac37ff6 100644
--- a/src/rgw/rgw_cache.h
+++ b/src/rgw/rgw_cache.h
@@ -149,6 +149,7 @@ class ObjectCache {
 
   void touch_lru(string& name, ObjectCacheEntry& entry, std::list<string>::iterator& lru_iter);
   void remove_lru(string& name, std::list<string>::iterator& lru_iter);
+  void invalidate_lru(ObjectCacheEntry& entry);
 
   void do_invalidate_all();
 public: