From f3d0dbe5a8e367eade313a853431dd3c886da646 Mon Sep 17 00:00:00 2001
From: Sy03 <1370724210@qq.com>
Date: Mon, 5 Oct 2026 22:07:14 +0800
Subject: [PATCH] [Bugfix] Preserve host transport fallback when discovery
 cleanup fails

Signed-off-by: Sy03 <1370724210@qq.com>
---
 .../distributed/omni_connectors/test_shm_ring.py | 16 ++++++++++++++++
 .../omni_connectors/connectors/shm_ring.py       |  6 ++++++
 2 files changed, 22 insertions(+)

diff --git a/tests/distributed/omni_connectors/test_shm_ring.py b/tests/distributed/omni_connectors/test_shm_ring.py
index fccbd38c7..3693b0c70 100644
--- a/tests/distributed/omni_connectors/test_shm_ring.py
+++ b/tests/distributed/omni_connectors/test_shm_ring.py
@@ -9,6 +9,7 @@ import time
 import uuid
 from dataclasses import asdict
 from multiprocessing import shared_memory
+from pathlib import Path
 
 import msgspec
 import numpy as np
@@ -446,6 +447,21 @@ def test_ring_setup_failure_keeps_connector_usable(edge, monkeypatch):
     assert receiver.get("0", "1", "no-ring-space")[0].tolist() == [0, 1, 2]
 
 
+def test_discovery_stamp_failure_keeps_fallback_and_cleanup_usable(edge, monkeypatch):
+    sender, receiver = edge
+
+    def stamp_denied(*args, **kwargs):
+        raise PermissionError("directory timestamp update denied")
+
+    monkeypatch.setattr(os, "utime", stamp_denied)
+    ok, _, metadata = sender.put("0", "1", "no-ring-stamp", torch.arange(3))
+    assert ok and "shm" in metadata
+    assert not sender._host_ring.producers
+    assert not list(Path(f"/dev/shm/{sender._host_ring.directory}").iterdir())
+    assert receiver.get("0", "1", "no-ring-stamp")[0].tolist() == [0, 1, 2]
+    sender.close()
+
+
 def test_close_is_idempotent_and_removes_owned_ring(edge):
     sender, receiver = edge
     _, _, metadata = sender.put("0", "1", "close", torch.arange(3))
diff --git a/vllm_omni/distributed/omni_connectors/connectors/shm_ring.py b/vllm_omni/distributed/omni_connectors/connectors/shm_ring.py
index f3376e217..0bce1b10d 100644
--- a/vllm_omni/distributed/omni_connectors/connectors/shm_ring.py
+++ b/vllm_omni/distributed/omni_connectors/connectors/shm_ring.py
@@ -233,6 +233,10 @@ class _Channel:
                     os.unlink(os.path.basename(self.registry), dir_fd=directory_fd)
             except FileNotFoundError:
                 pass
+            except OSError as error:
+                # The allocation is already retired. A failed discovery stamp
+                # must not mask setup failure or prevent the per-key fallback.
+                logger.debug("Failed to retire host ring marker %s: %s", self.registry, error)
 
 
 class HostRingTransport:
@@ -423,6 +427,8 @@ class HostRingTransport:
                             os.unlink(name, dir_fd=directory_fd)
                     except FileNotFoundError:
                         pass
+                    except OSError as error:
+                        logger.debug("Failed to prune host ring marker %s: %s", path, error)
                     continue
                 except (BlockingIOError, ValueError):
                     # Attachment may race a writer holding the frame lock.