From 238f0ef4a44481787fa36db99c78936480202d6f Mon Sep 17 00:00:00 2001
From: Yehuda Sadeh <yehuda@redhat.com>
Date: Fri, 26 Oct 2018 16:20:05 -0700
Subject: [PATCH] rgw: chained cache shouldn't access service after it was
 unchained

This fixes a cleanup ordering issue. We can now have the chained cache
removed before and after the service is destructed.

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>
---
 src/rgw/rgw_cache.cc                 | 8 ++++++++
 src/rgw/rgw_cache.h                  | 3 +++
 src/rgw/services/svc_sys_obj_cache.h | 4 ++++
 3 files changed, 15 insertions(+)

diff --git a/src/rgw/rgw_cache.cc b/src/rgw/rgw_cache.cc
index a53940b2626..fe8ab51f539 100644
--- a/src/rgw/rgw_cache.cc
+++ b/src/rgw/rgw_cache.cc
@@ -329,8 +329,16 @@ void ObjectCache::unchain_cache(RGWChainedCache *cache) {
   for (; iter != chained_cache.end(); ++iter) {
     if (cache == *iter) {
       chained_cache.erase(iter);
+      cache->unregistered();
       return;
     }
   }
 }
 
+ObjectCache::~ObjectCache()
+{
+  for (auto cache : chained_cache) {
+    cache->unregistered();
+  }
+}
+
diff --git a/src/rgw/rgw_cache.h b/src/rgw/rgw_cache.h
index 60087f92ea4..b0696237fe6 100644
--- a/src/rgw/rgw_cache.h
+++ b/src/rgw/rgw_cache.h
@@ -132,6 +132,7 @@ public:
   virtual void chain_cb(const string& key, void *data) = 0;
   virtual void invalidate(const string& key) = 0;
   virtual void invalidate_all() = 0;
+  virtual void unregistered() {}
 
   struct Entry {
     RGWChainedCache *cache;
@@ -173,8 +174,10 @@ class ObjectCache {
   void invalidate_lru(ObjectCacheEntry& entry);
 
   void do_invalidate_all();
+
 public:
   ObjectCache() : lru_size(0), lru_counter(0), lru_window(0), lock("ObjectCache"), cct(NULL), enabled(false) { }
+  ~ObjectCache();
   int get(const std::string& name, ObjectCacheInfo& bl, uint32_t mask, rgw_cache_entry_info *cache_info);
   std::optional<ObjectCacheInfo> get(const std::string& name) {
     std::optional<ObjectCacheInfo> info{std::in_place};
diff --git a/src/rgw/services/svc_sys_obj_cache.h b/src/rgw/services/svc_sys_obj_cache.h
index 7b986fe5089..fefbc298cd8 100644
--- a/src/rgw/services/svc_sys_obj_cache.h
+++ b/src/rgw/services/svc_sys_obj_cache.h
@@ -112,6 +112,10 @@ public:
     svc->unregister_chained_cache(this);
   }
 
+  void unregistered() override {
+    svc = nullptr;
+  }
+
   void init(RGWSI_SysObj_Cache *_svc) {
     if (!_svc) {
       return;
-- 
2.39.5