From 91f777ad2707cfe32fcf61c4b0b0b59d7bb0bd54 Mon Sep 17 00:00:00 2001
From: Xuehan Xu <xuxuehan@qianxin.com>
Date: Mon, 29 Apr 2024 12:11:51 +0800
Subject: [PATCH] crimson/osd/pg: reset the snap mapper's backend when pg
 interval changes

Fixes: https://tracker.ceph.com/issues/65679
Signed-off-by: Xuehan Xu <xuxuehan@qianxin.com>
(cherry picked from commit 9f6ccafb8656865c87c3052b12422322e1d1d276)
---
 src/common/map_cacher.hpp         | 4 ++++
 src/common/sharedptr_registry.hpp | 6 ++++++
 src/crimson/osd/pg.cc             | 1 +
 src/osd/SnapMapper.h              | 5 +++++
 4 files changed, 16 insertions(+)

diff --git a/src/common/map_cacher.hpp b/src/common/map_cacher.hpp
index a83f924b622c0..4d843be75dc64 100644
--- a/src/common/map_cacher.hpp
+++ b/src/common/map_cacher.hpp
@@ -85,6 +85,10 @@ private:
 public:
   MapCacher(StoreDriver<K, V> *driver) : driver(driver) {}
 
+  void reset() {
+    in_progress.reset();
+  }
+
   /// Fetch first key/value std::pair after specified key
   int get_next(
     K key,               ///< [in] key after which to get next
diff --git a/src/common/sharedptr_registry.hpp b/src/common/sharedptr_registry.hpp
index 3b3cf01bb28a0..8c0db6c24a702 100644
--- a/src/common/sharedptr_registry.hpp
+++ b/src/common/sharedptr_registry.hpp
@@ -18,6 +18,7 @@
 #include <map>
 #include <memory>
 #include "common/ceph_mutex.h"
+#include "include/ceph_assert.h"
 
 /**
  * Provides a registry of shared_ptr<V> indexed by K while
@@ -61,6 +62,11 @@ public:
     waiting(0)
   {}
 
+  void reset() {
+    ceph_assert(!waiting);
+    contents.clear();
+  }
+
   bool empty() {
     std::lock_guard l(lock);
     return contents.empty();
diff --git a/src/crimson/osd/pg.cc b/src/crimson/osd/pg.cc
index ad777c49d6011..fd7e09a898462 100644
--- a/src/crimson/osd/pg.cc
+++ b/src/crimson/osd/pg.cc
@@ -1592,6 +1592,7 @@ void PG::on_change(ceph::os::Transaction &t) {
   // is save and in time.
   peering_state.state_clear(PG_STATE_SNAPTRIM);
   peering_state.state_clear(PG_STATE_SNAPTRIM_ERROR);
+  snap_mapper.reset_backend();
 }
 
 void PG::context_registry_on_change() {
diff --git a/src/osd/SnapMapper.h b/src/osd/SnapMapper.h
index 70d1b6c39add7..688a7b8f1fffe 100644
--- a/src/osd/SnapMapper.h
+++ b/src/osd/SnapMapper.h
@@ -357,6 +357,11 @@ private:
     return prefix_itr;
   }
 
+  /// reset the MapCacher backend, this should be called on pg interval change
+  void reset_backend() {
+    backend.reset();
+  }
+
   /// Update snaps for oid, empty new_snaps removes the mapping
   int update_snaps(
     const hobject_t &oid,       ///< [in] oid to update
-- 
2.39.5