fix(ecstore): migrate tier free versions during decommission

crates/ecstore/src/set_disk/mod.rs

@@ -4642,6 +4642,63 @@ fn resolve_delete_version_state(opts: &ObjectOptions, goi: &ObjectInfo, version_
 }
 
 impl SetDisks {
+    /// Publish an internal tier free-version record without changing its
+    /// delete-marker shape or remote-tier identity. The caller holds the
+    /// source and target object locks; a write quorum is required before the
+    /// source cleanup may remove the original record.
+    #[tracing::instrument(skip(self, fi, opts))]
+    pub(crate) async fn decommission_tier_free_version(
+        &self,
+        bucket: &str,
+        object: &str,
+        fi: &FileInfo,
+        opts: &ObjectOptions,
+    ) -> Result<()> {
+        if !fi.deleted || !fi.tier_free_version() {
+            return Err(Error::other("decommission tier free-version write requires a free version record"));
+        }
+        if opts
+            .namespace_lock_fence
+            .as_ref()
+            .is_some_and(NamespaceLockFence::is_lock_lost)
+            || opts
+                .bucket_lifecycle_lock_fence
+                .as_ref()
+                .is_some_and(NamespaceLockFence::is_lock_lost)
+        {
+            return Err(StorageError::NamespaceLockQuorumUnavailable {
+                mode: "decommission_tier_free_version_commit",
+                bucket: bucket.to_string(),
+                object: object.to_string(),
+                required: 1,
+                achieved: 0,
+            });
+        }
+
+        let disks = self.disks.read().await.clone();
+        let write_quorum = self.default_write_quorum();
+        let futures = disks.into_iter().map(|disk| {
+            let file_info = fi.clone();
+            async move {
+                if let Some(disk) = disk {
+                    disk.write_metadata("", bucket, object, file_info).await
+                } else {
+                    Err(DiskError::DiskNotFound)
+                }
+            }
+        });
+
+        let mut errs = Vec::new();
+        for result in join_all(futures).await {
+            match result {
+                Ok(_) => errs.push(None),
+                Err(err) => errs.push(Some(err)),
+            }
+        }
+
+        resolve_tiered_decommission_write_quorum_result(&errs, write_quorum, bucket, object)
+    }
+
     #[tracing::instrument(skip(self, fi, opts))]
     pub(crate) async fn decommission_tiered_object(
         &self,
@@ -9864,6 +9921,57 @@ mod tests {
         assert_ne!(updated.erasure.distribution, original.erasure.distribution);
     }
 
+    #[tokio::test]
+    async fn decommission_tier_free_version_preserves_remote_identity() {
+        let set_disks = make_local_bucket_test_set_disks().await;
+        let bucket = "free-version-decommission";
+        let object = "object.txt";
+        let version_id = Uuid::new_v4();
+        let mut free_version = FileInfo {
+            name: object.to_string(),
+            volume: bucket.to_string(),
+            version_id: Some(version_id),
+            mod_time: Some(time::OffsetDateTime::now_utc()),
+            deleted: true,
+            transition_tier: "WARM-TIER".to_string(),
+            transitioned_objname: "remote/object".to_string(),
+            ..Default::default()
+        };
+        free_version.set_tier_free_version();
+
+        set_disks
+            .decommission_tier_free_version(bucket, object, &free_version, &ObjectOptions::default())
+            .await
+            .expect("free-version metadata should reach the target quorum");
+        set_disks
+            .decommission_tier_free_version(bucket, object, &free_version, &ObjectOptions::default())
+            .await
+            .expect("replaying the same free-version metadata should be idempotent");
+
+        let versions = set_disks
+            .load_file_info_versions_exact(bucket, object)
+            .await
+            .expect("migrated free-version metadata should decode")
+            .expect("migrated free-version metadata should exist");
+        let migrated = versions
+            .versions
+            .iter()
+            .find(|version| version.version_id == Some(version_id))
+            .expect("free version should be present on the target");
+
+        assert_eq!(
+            versions
+                .versions
+                .iter()
+                .filter(|version| version.version_id == Some(version_id))
+                .count(),
+            1
+        );
+        assert!(migrated.tier_free_version());
+        assert_eq!(migrated.transition_tier, "WARM-TIER");
+        assert_eq!(migrated.transitioned_objname, "remote/object");
+    }
+
     #[test]
     fn test_resolve_tiered_decommission_write_quorum_result_allows_successful_quorum() {
         let errs = vec![None, None, Some(DiskError::DiskNotFound), None];