fix(ecstore): start with unresolved Kubernetes peers (#5460)

* fix(ecstore): start with unresolved Kubernetes peers

* fix(ecstore): infer Kubernetes endpoint identity safely

* fix(ecstore): fail closed on unsafe format migration

* fix(ecstore): reject poisoned format heal candidates

* fix(ecstore): reject unsafe legacy migration outliers

* fix(ecstore): resume interrupted format migrations

* fix(ecstore): preserve Kubernetes startup compatibility

crates/ecstore/src/set_disk/ops/locking.rs

@@ -343,20 +343,23 @@ impl SetDisks {
             }
         };
 
-        // The drive's format may place it in a different erasure set than this
-        // one. Claiming a misplaced drive into `self.disks` would let two sets
-        // manage the same drive and degrade together, so reject it here
-        // (backlog#799 B19).
-        if set_idx != self.set_index {
+        // Claiming a misplaced drive into `self.disks` would let two slots or
+        // sets manage the same drive and degrade together (backlog#799 B19).
+        if set_idx != self.set_index || self.set_endpoints.get(disk_idx) != Some(ep) {
             warn!(
-                "renew_disk: drive {:?} belongs to set {} but is being renewed on set {}; skipping",
-                ep, set_idx, self.set_index
+                endpoint = %ep,
+                format_set_index = set_idx,
+                format_disk_index = disk_idx,
+                endpoint_pool_index = ep.pool_idx,
+                endpoint_set_index = ep.set_idx,
+                endpoint_disk_index = ep.disk_idx,
+                expected_pool_index = self.pool_index,
+                expected_set_index = self.set_index,
+                "renew_disk rejected a drive whose endpoint and format do not identify the same topology slot"
             );
             return;
         }
 
-        // Check that the endpoint matches
-
         let _ = new_disk.set_disk_id(Some(fm.erasure.this)).await;
         new_disk.enable_health_check();
 
@@ -715,6 +718,108 @@ mod tests {
         drop(temp_dirs);
     }
 
+    #[tokio::test]
+    async fn renew_disk_rejects_a_format_from_another_slot_or_cluster() {
+        let disk_count = 3;
+        let format = FormatV3::new(1, disk_count);
+        let mut temp_dirs = Vec::with_capacity(disk_count);
+        let mut endpoints = Vec::with_capacity(disk_count);
+        let mut fixture_disks = Vec::with_capacity(disk_count);
+
+        for disk_idx in 0..disk_count {
+            let (temp_dir, endpoint, disk) = make_formatted_local_disk(disk_idx, &format).await;
+            temp_dirs.push(temp_dir);
+            endpoints.push(endpoint);
+            fixture_disks.push(disk);
+        }
+
+        let set_disks = SetDisks::new(
+            "test-owner".to_string(),
+            Arc::new(RwLock::new(vec![Some(fixture_disks[0].clone()), None, None])),
+            disk_count,
+            disk_count / 2,
+            0,
+            0,
+            endpoints.clone(),
+            format.clone(),
+            Vec::new(),
+        )
+        .await;
+
+        let mut other_cluster_format = format.clone();
+        other_cluster_format.id = Uuid::new_v4();
+        other_cluster_format.erasure.this = format.erasure.sets[0][2];
+        save_format_file(&Some(fixture_disks[2].clone()), &Some(other_cluster_format))
+            .await
+            .expect("other-cluster format should be written for the rejection test");
+
+        set_disks.renew_disk(&endpoints[2]).await;
+
+        let disks = set_disks.get_disks_internal().await;
+        assert_eq!(
+            disks[0]
+                .as_ref()
+                .expect("the canonical first slot must remain attached")
+                .endpoint(),
+            endpoints[0]
+        );
+        assert!(
+            disks[2].is_none(),
+            "a disk from another deployment must remain detached even when its slot UUID matches"
+        );
+
+        let mut correct_format = format.clone();
+        correct_format.erasure.this = format.erasure.sets[0][2];
+        let replacement_disk = new_disk(
+            &endpoints[2],
+            &DiskOption {
+                cleanup: false,
+                health_check: false,
+            },
+        )
+        .await
+        .expect("third endpoint should reopen after other-cluster rejection");
+        save_format_file(&Some(replacement_disk), &Some(correct_format))
+            .await
+            .expect("correct slot format should be restored");
+
+        set_disks.renew_disk(&endpoints[2]).await;
+
+        let disks = set_disks.get_disks_internal().await;
+        assert_eq!(
+            disks[0]
+                .as_ref()
+                .expect("the canonical first slot must remain attached")
+                .endpoint(),
+            endpoints[0]
+        );
+        assert_eq!(disks[2].as_ref().expect("the restored third slot should attach").endpoint(), endpoints[2]);
+
+        let third_disk = disks[2].clone();
+        let mut wrong_slot_format = format.clone();
+        wrong_slot_format.erasure.this = format.erasure.sets[0][0];
+        save_format_file(&third_disk, &Some(wrong_slot_format))
+            .await
+            .expect("wrong-slot format should be written for the rejection test");
+        set_disks.disks.write().await[2] = None;
+
+        let mut misplaced_endpoint = endpoints[2].clone();
+        misplaced_endpoint.set_disk_index(0);
+        set_disks.renew_disk(&misplaced_endpoint).await;
+
+        let disks = set_disks.get_disks_internal().await;
+        assert_eq!(
+            disks[0]
+                .as_ref()
+                .expect("the canonical first slot must remain attached")
+                .endpoint(),
+            endpoints[0]
+        );
+        assert!(disks[2].is_none(), "a disk claiming another endpoint's slot must remain detached");
+
+        drop(temp_dirs);
+    }
+
     // SetDisks split P0 (#816): the borrow handle must mirror the core state and
     // the List operation family must run identically through it.
     #[tokio::test]