From: Xuehan Xu <xuxuehan@qianxin.com>
Date: Wed, 13 May 2026 11:51:58 +0000 (+0800)
Subject: crimson/os/seastore: drop backref when all backends are RBMs
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e4979f98ed5be34f4fce9eb17cff27b14e9985bd;p=ceph.git

crimson/os/seastore: drop backref when all backends are RBMs

Signed-off-by: Xuehan Xu <xuxuehan@qianxin.com>
---

diff --git a/src/crimson/os/seastore/async_cleaner.h b/src/crimson/os/seastore/async_cleaner.h
index 59f0311a72b2..1efc06b3c575 100644
--- a/src/crimson/os/seastore/async_cleaner.h
+++ b/src/crimson/os/seastore/async_cleaner.h
@@ -702,7 +702,7 @@ private:
   }
 
   bool can_drop_backref() const {
-    return get_backend_type() == backend_type_t::RANDOM_BLOCK;
+    return !tail_include_alloc;
   }
 
   bool should_trim_alloc() const {
diff --git a/src/crimson/os/seastore/extent_placement_manager.h b/src/crimson/os/seastore/extent_placement_manager.h
index 11463df8fb33..8bd25d67219a 100644
--- a/src/crimson/os/seastore/extent_placement_manager.h
+++ b/src/crimson/os/seastore/extent_placement_manager.h
@@ -689,8 +689,9 @@ public:
 
   bool is_pure_rbm() const {
     return get_main_backend_type() == backend_type_t::RANDOM_BLOCK &&
-      // as of now, cold tier can only be segmented.
-      !background_process.has_cold_tier();
+      (!background_process.has_cold_tier() ||
+       (background_process.get_cold_tier_backend_type() ==
+        backend_type_t::RANDOM_BLOCK));
   }
 
   bool has_cold_tier() const {
@@ -945,6 +946,11 @@ private:
       return cold_cleaner.get() != nullptr;
     }
 
+    backend_type_t get_cold_tier_backend_type() const {
+      assert(cold_cleaner);
+      return cold_cleaner->get_backend_type();
+    }
+
     bool is_cold_device(device_id_t id) const {
       if (!has_cold_tier()) {
         return false;