From: Krunal Chheda <kchheda3@bloomberg.net>
Date: Wed, 20 May 2026 18:14:22 +0000 (-0400)
Subject: rgw/notification: fix zero eventTime in bucket notifications on concurrent PUT race
X-Git-Tag: v21.0.1~25^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=0064cc00eeb2911c4b9cc417a34b026a70e9d1ad;p=ceph.git

rgw/notification: fix zero eventTime in bucket notifications on concurrent PUT race

When concurrent PUTs target the same object key, RADOS may return
-ECANCELED to the losing writers. In that path *meta.mtime was never
populated from meta.set_mtime, leaving mtime at epoch (zero), which
propagated into bucket notification eventTime as
"1970-01-01T00:00:00.000Z".

Fix: set *meta.mtime from meta.set_mtime before returning 0 in the
ECANCELED/ENOENT/EEXIST early-return block, matching the behaviour of
the successful write path.

Also add a regression test that fires 20 concurrent threads writing
the same key and asserts no event in the persistent queue carries a
zero eventTime.

Fixes: https://tracker.ceph.com/issues/76729

Signed-off-by: Krunal Chheda <kchheda3@bloomberg.net>
---

diff --git a/src/rgw/driver/rados/rgw_rados.cc b/src/rgw/driver/rados/rgw_rados.cc
index 936a1109b55..ed1b72313d7 100644
--- a/src/rgw/driver/rados/rgw_rados.cc
+++ b/src/rgw/driver/rados/rgw_rados.cc
@@ -3610,6 +3610,9 @@ done_cancel:
    */
   if (meta.if_match == NULL && meta.if_nomatch == NULL) {
     if (r == -ECANCELED || r == -ENOENT || r == -EEXIST) {
+      if (meta.mtime) {
+        *meta.mtime = meta.set_mtime;
+      }
       r = 0;
     }
   } else {
diff --git a/src/test/rgw/bucket_notification/test_bn.py b/src/test/rgw/bucket_notification/test_bn.py
index 459211af2c3..fa5fa5b941e 100644
--- a/src/test/rgw/bucket_notification/test_bn.py
+++ b/src/test/rgw/bucket_notification/test_bn.py
@@ -3505,6 +3505,79 @@ def test_persistent_topic_dump():
     receiver.close(task)
 
 
+@pytest.mark.basic_test
+def test_ps_s3_notification_concurrent_put_eventtime():
+    """ test that eventTime is never zero when concurrent PUTs race on same key """
+    conn = connection()
+    zonegroup = get_config_zonegroup()
+
+    host = get_ip()
+    port = random.randint(10000, 20000)
+
+    bucket_name = gen_bucket_name()
+    bucket = conn.create_bucket(bucket_name)
+    topic_name = bucket_name + TOPIC_SUFFIX
+
+    # persistent topic with unreachable endpoint so events stay in queue
+    endpoint_address = 'http://' + host + ':' + str(port)
+    endpoint_args = 'push-endpoint=' + endpoint_address + '&persistent=true' + \
+                    '&retry_sleep_duration=100'
+    topic_conf = PSTopicS3(conn, topic_name, zonegroup,
+                           endpoint_args=endpoint_args)
+    topic_arn = topic_conf.set_config()
+
+    notification_name = bucket_name + NOTIFICATION_SUFFIX
+    topic_conf_list = [{'Id': notification_name, 'TopicArn': topic_arn,
+                        'Events': ['s3:ObjectCreated:*']}]
+    s3_notification_conf = PSNotificationS3(conn, bucket_name, topic_conf_list)
+    response, status = s3_notification_conf.set_config()
+    assert status // 100 == 2
+
+    # concurrent PUTs to the SAME key to trigger RADOS-level ECANCELED race
+    num_threads = 20
+    num_rounds = 5
+    key_name = 'race-target'
+
+    for round_num in range(num_rounds):
+        client_threads = []
+        for i in range(num_threads):
+            key = bucket.new_key(key_name)
+            content = str(os.urandom(128)) + str(round_num) + str(i)
+            thr = threading.Thread(target=set_contents_from_string,
+                                   args=(key, content,))
+            thr.start()
+            client_threads.append(thr)
+        [thr.join() for thr in client_threads]
+
+    time.sleep(2)
+    result = admin(['topic', 'dump', '--topic', topic_name],
+                   get_config_cluster())
+    assert result[1] == 0
+    parsed_result = json.loads(result[0])
+    log.info(f'topic dump has {len(parsed_result)} events')
+    assert len(parsed_result) > 0, 'expected at least one notification event in queue'
+
+    zero_time_count = 0
+    for entry in parsed_result:
+        event = entry.get('entry', {}).get('event', {})
+        event_time = event.get('eventTime', '')
+        if event_time in ('0.000000', '1970-01-01T00:00:00.000Z',
+                          '1970-01-01T00:00:00.000000Z', ''):
+            zero_time_count += 1
+            log.info(f'FOUND zero eventTime: '
+                     f'key={event.get("s3", {}).get("object", {}).get("key", "?")} '
+                     f'eventTime={event_time}')
+
+    s3_notification_conf.del_config()
+    topic_conf.del_config()
+    for key in bucket.list():
+        key.delete()
+    conn.delete_bucket(bucket_name)
+
+    assert zero_time_count == 0, \
+        f'{zero_time_count} out of {len(parsed_result)} events had zero eventTime'
+
+
 def persistent_topic_configs(persistency_time, config_dict):
     # create connection with no retries
     conn = connection(no_retries=True)