fix(object-lock): require source timestamps before replication passes WORM gate

Adversarial review of the replication WORM bypass found a silent unlock:
an authorized replication write that carries no source timestamp for a
category (the source never held the object, only its tags changed) is
not judged by receiver-side LWW, so the metadata replace would drop the
destination's legal hold or retention unjudged. Before the bypass that
write was merely rejected.

Gate the bypass on `replication_write_may_pass_worm_gate`: the write
passes only when it carries the source timestamp of every category that
currently locks the version, so LWW decides each one; otherwise it stays
WORM-rejected. The set layer evaluates the lock gate first so malformed
persisted lock metadata still fails closed, and the app-layer pre-check
applies the same rule.

Refs rustfs/backlog#1953

crates/e2e_test/src/lib.rs

@@ -61,6 +61,11 @@ mod get_codec_streaming_compat_test;
 #[cfg(test)]
 mod version_id_regression_test;
 
+// Receiver-side replication LWW (rustfs/backlog#1953): stale inbound
+// replication metadata must not overwrite a newer local category state.
+#[cfg(test)]
+mod replication_lww_receiver_test;
+
 // Data usage regression tests
 #[cfg(test)]
 mod data_usage_test;

crates/e2e_test/src/replication_lww_receiver_test.rs

@@ -0,0 +1,152 @@
+#![cfg(test)]
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Receiver-side replication LWW over the wire (rustfs/backlog#1953, audit
+//! A4/P1-6).
+//!
+//! In an active-active topology both sites' metadata states arrive at the
+//! peer as authorized replication PUTs carrying per-category source
+//! timestamps (`x-rustfs-source-replication-tagging-timestamp` header
+//! family). Before the fix the receiver applied them unconditionally, so a
+//! stale delivery overwrote a newer local state and the two sites diverged
+//! permanently while both reported COMPLETED. This test drives one live
+//! `rustfs` server with simulated inbound replication PUTs for the same
+//! object version and asserts the newer tagging state wins regardless of
+//! delivery order, while a stale delivery still succeeds at the object level
+//! (a failure would loop through MRF re-delivering the stale value).
+
+use crate::common::{RustFSTestEnvironment, init_logging};
+use aws_sdk_s3::Client;
+use aws_sdk_s3::primitives::ByteStream;
+use aws_sdk_s3::types::{BucketVersioningStatus, VersioningConfiguration};
+use serial_test::serial;
+
+type TestResult = Result<(), Box<dyn std::error::Error + Send + Sync>>;
+
+const HDR_SOURCE_REPLICATION_REQUEST: &str = "x-rustfs-source-replication-request";
+const HDR_SOURCE_VERSION_ID: &str = "x-rustfs-source-version-id";
+const HDR_SOURCE_MTIME: &str = "x-rustfs-source-mtime";
+const HDR_SOURCE_TAGGING_TIMESTAMP: &str = "x-rustfs-source-replication-tagging-timestamp";
+
+const SOURCE_MTIME: &str = "2026-01-01T00:00:00Z";
+const T_STALE: &str = "2026-01-01T00:00:01Z";
+const T_LOCAL: &str = "2026-02-01T00:00:00Z";
+const T_NEWER: &str = "2026-03-01T00:00:00Z";
+
+/// Simulated inbound authorized replication PUT: same object version, tags and
+/// the source-authored tagging timestamp carried in transport headers.
+async fn inbound_replication_put(
+    client: &Client,
+    bucket: &str,
+    key: &str,
+    version_id: &str,
+    tags: &str,
+    tagging_timestamp: &str,
+) -> TestResult {
+    let version_id = version_id.to_string();
+    let tagging_timestamp = tagging_timestamp.to_string();
+    client
+        .put_object()
+        .bucket(bucket)
+        .key(key)
+        .body(ByteStream::from_static(b"lww-e2e-body"))
+        .tagging(tags)
+        .customize()
+        .mutate_request(move |req| {
+            req.headers_mut().insert(HDR_SOURCE_REPLICATION_REQUEST, "true");
+            req.headers_mut().insert(HDR_SOURCE_VERSION_ID, version_id.clone());
+            req.headers_mut().insert(HDR_SOURCE_MTIME, SOURCE_MTIME);
+            req.headers_mut()
+                .insert(HDR_SOURCE_TAGGING_TIMESTAMP, tagging_timestamp.clone());
+        })
+        .send()
+        .await?;
+    Ok(())
+}
+
+async fn tag_value(client: &Client, bucket: &str, key: &str, version_id: &str, tag_key: &str) -> Option<String> {
+    let tagging = client
+        .get_object_tagging()
+        .bucket(bucket)
+        .key(key)
+        .version_id(version_id)
+        .send()
+        .await
+        .expect("object tagging should be readable");
+    tagging
+        .tag_set()
+        .iter()
+        .find(|tag| tag.key() == tag_key)
+        .map(|tag| tag.value().to_string())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+#[serial]
+async fn receiver_lww_keeps_newer_tags_across_delivery_orders() -> TestResult {
+    init_logging();
+    let mut env = RustFSTestEnvironment::new().await?;
+    env.start_rustfs_server(vec![]).await?;
+    let client = env.create_s3_client();
+
+    let bucket = "replication-lww-receiver";
+    let key = "object";
+    client.create_bucket().bucket(bucket).send().await?;
+    client
+        .put_bucket_versioning()
+        .bucket(bucket)
+        .versioning_configuration(
+            VersioningConfiguration::builder()
+                .status(BucketVersioningStatus::Enabled)
+                .build(),
+        )
+        .send()
+        .await?;
+
+    // First delivery establishes version V with tags stamped T_LOCAL.
+    let version_id = uuid::Uuid::new_v4().to_string();
+    inbound_replication_put(&client, bucket, key, &version_id, "site=local", T_LOCAL).await?;
+    assert_eq!(
+        tag_value(&client, bucket, key, &version_id, "site").await.as_deref(),
+        Some("local"),
+        "the first delivery must establish the tagged version"
+    );
+
+    // A stale delivery (older source timestamp) must succeed at the object
+    // level but must NOT overwrite the newer tags.
+    inbound_replication_put(&client, bucket, key, &version_id, "site=stale", T_STALE).await?;
+    assert_eq!(
+        tag_value(&client, bucket, key, &version_id, "site").await.as_deref(),
+        Some("local"),
+        "a stale inbound delivery must not overwrite newer tags (rustfs/backlog#1953)"
+    );
+
+    // A newer delivery still converges the version onto the newest state.
+    inbound_replication_put(&client, bucket, key, &version_id, "site=newer", T_NEWER).await?;
+    assert_eq!(
+        tag_value(&client, bucket, key, &version_id, "site").await.as_deref(),
+        Some("newer"),
+        "a newer inbound delivery must overwrite older tags"
+    );
+
+    client
+        .delete_object()
+        .bucket(bucket)
+        .key(key)
+        .version_id(&version_id)
+        .send()
+        .await?;
+    env.delete_test_bucket(bucket).await.ok();
+    Ok(())
+}

crates/ecstore/src/api/mod.rs

@@ -161,7 +161,7 @@ pub mod bucket {
         pub mod objectlock_sys {
             pub use crate::bucket::object_lock::objectlock_sys::{
                 BucketObjectLockSys, ObjectLockBlockReason, add_years, check_object_lock_for_deletion,
-                check_retention_for_modification, is_retention_active,
+                check_retention_for_modification, is_retention_active, replication_write_may_pass_worm_gate,
             };
         }
     }
@@ -196,16 +196,15 @@ pub mod bucket {
             ReplicationOperation, ReplicationPoolTrait, ReplicationPriority, ReplicationQueueAdmission, ReplicationScannerBridge,
             ReplicationState, ReplicationStats, ReplicationStatusType, ReplicationStorage, ReplicationTargetValidationError,
             ReplicationType, ResyncOpts, ResyncStatusType, RuntimeReplicationTargetBacklog, TargetReplicationResyncStatus,
-            VersionPurgeStatusType, XferStats, assign_site_replication_rule_priorities, commit_force_delete_intent,
-            complete_force_delete_intent, delete_replication_state_from_config, delete_replication_version_id,
-            get_global_replication_pool, get_global_replication_stats, get_proxy_targets, init_background_replication,
-            invalid_replication_config_status_field, is_site_replication_rule, merge_incoming_replication_config,
-            merge_user_replication_config, persist_force_delete_intent, read_durable_mrf_backlog, replication_state_to_filemeta,
-            replication_status_to_filemeta, replication_statuses_map, replication_target_arn_deployment_id,
-            replication_target_arns, resync_start_conflict_id, should_remove_replication_target,
-            should_schedule_delete_replication, should_use_existing_delete_replication_info,
-            should_use_existing_delete_replication_source, unsupported_replication_config_field,
-            validate_replication_config_structure, validate_replication_config_target_arns, version_purge_status_to_filemeta,
+            VersionPurgeStatusType, XferStats, commit_force_delete_intent, complete_force_delete_intent,
+            delete_replication_state_from_config, delete_replication_version_id, get_global_replication_pool,
+            get_global_replication_stats, get_proxy_targets, init_background_replication,
+            invalid_replication_config_status_field, persist_force_delete_intent, read_durable_mrf_backlog,
+            replication_state_to_filemeta, replication_status_to_filemeta, replication_statuses_map, replication_target_arns,
+            resync_start_conflict_id, should_remove_replication_target, should_schedule_delete_replication,
+            should_use_existing_delete_replication_info, should_use_existing_delete_replication_source,
+            unsupported_replication_config_field, validate_replication_config_structure, validate_replication_config_target_arns,
+            version_purge_status_to_filemeta,
         };
     }
 

crates/ecstore/src/bucket/object_lock/objectlock_sys.rs

@@ -15,7 +15,7 @@
 use crate::bucket::metadata_sys::{ObjectLockConfigState, get_object_lock_config, get_object_lock_config_state};
 use crate::bucket::object_lock::objectlock;
 use crate::error::{Error, Result, StorageError};
-use crate::object_api::ObjectInfo;
+use crate::object_api::{ObjectInfo, ObjectOptions};
 use s3s::dto::{Date, DefaultRetention, ObjectLockConfiguration, ObjectLockLegalHoldStatus, ObjectLockRetentionMode};
 use s3s::header::{X_AMZ_OBJECT_LOCK_LEGAL_HOLD, X_AMZ_OBJECT_LOCK_MODE, X_AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE};
 use std::sync::Arc;
@@ -136,12 +136,41 @@ pub fn add_years(dt: OffsetDateTime, years: i32) -> OffsetDateTime {
 
 /// Check if an object has legal hold enabled.
 /// Returns true if legal hold is ON.
-#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn has_legal_hold(user_defined: &std::collections::HashMap<String, String>) -> bool {
     let lhold = objectlock::get_object_legalhold_meta(user_defined);
     matches!(lhold.status, Some(ref st) if st.as_str() == ObjectLockLegalHoldStatus::ON)
 }
 
+/// Whether an authorized replication write (`ObjectOptions::replication_request`)
+/// may overwrite a locked destination version.
+///
+/// The source's lock state governs a replica (MinIO `checkPutObjectLockAllowed`
+/// skips the existing-version check for replicas), and a source-side hold
+/// release or retention change reaches this site only through this write. The
+/// overwrite is allowed only when the write carries the source timestamp of
+/// every category that currently locks the version, so receiver-side LWW
+/// (`merge_replication_metadata_lww`) judges each of them: a category locked
+/// more recently here is kept, otherwise the source's newer state wins. A write
+/// without that timestamp carries no source decision for the category — the
+/// metadata replace would lift the lock unjudged — so it stays WORM-rejected.
+pub fn replication_write_may_pass_worm_gate(
+    user_defined: &std::collections::HashMap<String, String>,
+    opts: &ObjectOptions,
+) -> bool {
+    if !opts.replication_request {
+        return false;
+    }
+    if has_legal_hold(user_defined) && opts.replication_legalhold_timestamp.is_none() {
+        return false;
+    }
+    let ret = objectlock::get_object_retention_meta(user_defined);
+    let retention_locked = ret
+        .mode
+        .as_ref()
+        .is_some_and(|mode| is_retention_active(mode.as_str(), ret.retain_until_date.as_ref()));
+    !(retention_locked && opts.replication_retention_timestamp.is_none())
+}
+
 /// Check if an object is locked based on its metadata.
 /// This is a common function used by both lifecycle evaluation and deletion checks.
 ///
@@ -239,7 +268,12 @@ pub(crate) fn check_object_lock_for_deletion_with_config(
         return Ok(None);
     }
 
-    if let Some(status) = obj_info.user_defined.get(X_AMZ_OBJECT_LOCK_LEGAL_HOLD.as_str()) {
+    // A cleared retention / legal hold is persisted as empty strings (the
+    // MinIO on-disk shape, `parse_object_lock_retention`); read it as "no lock"
+    // rather than as corrupt metadata.
+    let persisted = |key: &str| obj_info.user_defined.get(key).filter(|value| !value.is_empty());
+
+    if let Some(status) = persisted(X_AMZ_OBJECT_LOCK_LEGAL_HOLD.as_str()) {
         if status.eq_ignore_ascii_case(ObjectLockLegalHoldStatus::ON) {
             return Ok(Some(ObjectLockBlockReason::LegalHold));
         }
@@ -248,8 +282,8 @@ pub(crate) fn check_object_lock_for_deletion_with_config(
         }
     }
 
-    let mode = obj_info.user_defined.get(X_AMZ_OBJECT_LOCK_MODE.as_str());
-    let retain_until = obj_info.user_defined.get(X_AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE.as_str());
+    let mode = persisted(X_AMZ_OBJECT_LOCK_MODE.as_str());
+    let retain_until = persisted(X_AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE.as_str());
     let explicit_ret = match (mode, retain_until) {
         (None, None) => None,
         (Some(mode), Some(retain_until)) => {
@@ -486,6 +520,98 @@ mod tests {
         }
     }
 
+    /// A replication write passes the WORM gate only when it carries the
+    /// source timestamp of every category that currently locks the version.
+    #[test]
+    fn replication_write_passes_worm_gate_only_with_every_locking_category_timestamp() {
+        use rustfs_utils::http::headers::{
+            AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER, AMZ_OBJECT_LOCK_MODE_LOWER, AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER,
+        };
+
+        let hold = [(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER, "ON")];
+        let retention = [
+            (AMZ_OBJECT_LOCK_MODE_LOWER, "GOVERNANCE"),
+            (AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER, "2099-01-01T00:00:00Z"),
+        ];
+        let expired = [
+            (AMZ_OBJECT_LOCK_MODE_LOWER, "COMPLIANCE"),
+            (AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER, "2000-01-01T00:00:00Z"),
+        ];
+        let metadata = |entries: &[&[(&str, &str)]]| -> std::collections::HashMap<String, String> {
+            entries
+                .iter()
+                .flat_map(|entries| entries.iter())
+                .map(|(key, value)| (key.to_string(), value.to_string()))
+                .collect()
+        };
+        let opts = |hold_ts: bool, retention_ts: bool| ObjectOptions {
+            replication_request: true,
+            replication_legalhold_timestamp: hold_ts.then_some(OffsetDateTime::UNIX_EPOCH),
+            replication_retention_timestamp: retention_ts.then_some(OffsetDateTime::UNIX_EPOCH),
+            ..Default::default()
+        };
+
+        let locked_by_both = metadata(&[&hold, &retention]);
+        assert!(replication_write_may_pass_worm_gate(&locked_by_both, &opts(true, true)));
+        assert!(!replication_write_may_pass_worm_gate(&locked_by_both, &opts(true, false)));
+        assert!(!replication_write_may_pass_worm_gate(&locked_by_both, &opts(false, true)));
+
+        assert!(replication_write_may_pass_worm_gate(&metadata(&[&hold]), &opts(true, false)));
+        assert!(!replication_write_may_pass_worm_gate(&metadata(&[&hold]), &opts(false, true)));
+        assert!(replication_write_may_pass_worm_gate(&metadata(&[&retention]), &opts(false, true)));
+        assert!(!replication_write_may_pass_worm_gate(&metadata(&[&retention]), &opts(true, false)));
+
+        // Expired retention and a released hold no longer lock anything.
+        let unlocked = metadata(&[&expired, &[(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER, "OFF")]]);
+        assert!(replication_write_may_pass_worm_gate(&unlocked, &opts(false, false)));
+
+        // Never for a non-replication write, whatever it carries.
+        let local = ObjectOptions {
+            replication_request: false,
+            ..opts(true, true)
+        };
+        assert!(!replication_write_may_pass_worm_gate(&metadata(&[&hold]), &local));
+    }
+
+    /// A local PutObjectRetention / PutObjectLegalHold "clear" persists the
+    /// lock keys as empty strings (the MinIO on-disk shape, see
+    /// `parse_object_lock_retention`); that is "no lock", not corruption, and
+    /// must not wedge later explicit-version PUTs or deletes
+    /// (rustfs/backlog#1953).
+    #[test]
+    fn deletion_treats_cleared_empty_lock_metadata_as_unlocked() {
+        use rustfs_utils::http::headers::{
+            AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER, AMZ_OBJECT_LOCK_MODE_LOWER, AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER,
+        };
+
+        let cases: [(&str, &[&str]); 3] = [
+            (
+                "cleared retention",
+                &[AMZ_OBJECT_LOCK_MODE_LOWER, AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER],
+            ),
+            ("cleared legal hold", &[AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER]),
+            (
+                "all cleared",
+                &[
+                    AMZ_OBJECT_LOCK_MODE_LOWER,
+                    AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER,
+                    AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER,
+                ],
+            ),
+        ];
+
+        for (case, keys) in cases {
+            let user_defined = keys.iter().map(|key| (key.to_string(), String::new())).collect();
+            let obj_info = ObjectInfo {
+                user_defined: Arc::new(user_defined),
+                ..Default::default()
+            };
+
+            let result = check_object_lock_for_deletion_with_config(None, &obj_info, false);
+            assert!(matches!(result, Ok(None)), "{case}: empty lock keys must read as unlocked: {result:?}");
+        }
+    }
+
     #[test]
     fn deletion_rejects_invalid_persisted_legal_hold_metadata() {
         let mut user_defined = std::collections::HashMap::new();

crates/ecstore/src/bucket/replication/mod.rs

@@ -47,10 +47,8 @@ pub use replication_config_boundary::{
     ObjectOpts, REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION, REMOTE_TARGET_UNSUPPORTED_FIELDS, REMOTE_TARGET_WRITABLE_FIELDS,
     REPLICATION_CAPABILITY_CONTRACT_VERSION, REPLICATION_READ_ONLY_HISTORICAL_FIELDS, REPLICATION_WRITABLE_FIELDS,
     ReplicationConfigStructureError, ReplicationConfigurationExt, ReplicationTargetValidationError,
-    assign_site_replication_rule_priorities, invalid_replication_config_status_field, is_site_replication_rule,
-    merge_incoming_replication_config, merge_user_replication_config, replication_target_arn_deployment_id,
-    replication_target_arns, should_remove_replication_target, unsupported_replication_config_field,
-    validate_replication_config_structure, validate_replication_config_target_arns,
+    invalid_replication_config_status_field, replication_target_arns, should_remove_replication_target,
+    unsupported_replication_config_field, validate_replication_config_structure, validate_replication_config_target_arns,
 };
 pub(crate) use replication_filemeta_boundary::version_purge_statuses_map;
 pub use replication_filemeta_boundary::{

crates/ecstore/src/bucket/replication/replication_config_boundary.rs

@@ -16,8 +16,6 @@ pub use rustfs_replication::{
     ObjectOpts, REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION, REMOTE_TARGET_UNSUPPORTED_FIELDS, REMOTE_TARGET_WRITABLE_FIELDS,
     REPLICATION_CAPABILITY_CONTRACT_VERSION, REPLICATION_READ_ONLY_HISTORICAL_FIELDS, REPLICATION_WRITABLE_FIELDS,
     ReplicationConfigStructureError, ReplicationConfigurationExt, ReplicationRuleExt, ReplicationTargetValidationError,
-    assign_site_replication_rule_priorities, invalid_replication_config_status_field, is_site_replication_rule,
-    merge_incoming_replication_config, merge_user_replication_config, replication_target_arn_deployment_id,
-    replication_target_arns, should_remove_replication_target, unsupported_replication_config_field,
-    validate_replication_config_structure, validate_replication_config_target_arns,
+    invalid_replication_config_status_field, replication_target_arns, should_remove_replication_target,
+    unsupported_replication_config_field, validate_replication_config_structure, validate_replication_config_target_arns,
 };

crates/ecstore/src/bucket/replication/replication_resyncer.rs

@@ -3868,6 +3868,7 @@ async fn replicate_object_with_multipart<S: ReplicationObjectIO>(ctx: MultipartR
                 actual_size,
                 object_info.etag.clone().unwrap_or_default(),
                 object_info.mod_time,
+                &put_opts.internal,
             ),
         )
         .await

crates/ecstore/src/bucket/replication/replication_target_boundary.rs

@@ -472,6 +472,7 @@ pub(crate) fn replication_complete_multipart_options(
     actual_size: String,
     source_etag: String,
     source_mtime: Option<OffsetDateTime>,
+    source_internal: &AdvancedPutOptions,
 ) -> PutObjectOptions {
     let mut user_metadata = HashMap::new();
     insert_header_map(&mut user_metadata, SUFFIX_REPLICATION_ACTUAL_OBJECT_SIZE, actual_size);
@@ -484,6 +485,14 @@ pub(crate) fn replication_complete_multipart_options(
             // mtime must degrade to epoch so header() suppresses the header
             // instead of asserting the replication time as the object's mtime.
             source_mtime: source_mtime.unwrap_or(OffsetDateTime::UNIX_EPOCH),
+            // Carry the per-category LWW timestamps on the complete request as
+            // well: the receiver's CompleteMultipartUpload options builder
+            // parses the same headers, so the multipart transport gets the
+            // same receiver-side LWW as the single-PUT transport
+            // (rustfs/backlog#1953). Epoch values keep the headers suppressed.
+            tagging_timestamp: source_internal.tagging_timestamp,
+            retention_timestamp: source_internal.retention_timestamp,
+            legalhold_timestamp: source_internal.legalhold_timestamp,
             replication_status: ReplicationStatusType::Replica,
             replication_request: true,
             ..Default::default()
@@ -649,20 +658,39 @@ mod tests {
     #[test]
     fn replication_complete_multipart_options_sets_actual_size() {
         let source_mtime = OffsetDateTime::from_unix_timestamp(1_716_170_000).expect("valid test timestamp");
+        let source_internal = AdvancedPutOptions {
+            tagging_timestamp: OffsetDateTime::from_unix_timestamp(1_716_170_100).expect("valid test timestamp"),
+            retention_timestamp: OffsetDateTime::from_unix_timestamp(1_716_170_200).expect("valid test timestamp"),
+            legalhold_timestamp: OffsetDateTime::from_unix_timestamp(1_716_170_300).expect("valid test timestamp"),
+            ..Default::default()
+        };
         let options = replication_complete_multipart_options(
             "1024".to_string(),
             "0123456789abcdef0123456789abcdef-3".to_string(),
             Some(source_mtime),
+            &source_internal,
         );
         assert_eq!(options.internal.source_etag, "0123456789abcdef0123456789abcdef-3");
         assert_eq!(options.internal.source_mtime, source_mtime);
 
+        // The complete request must carry the same per-category LWW timestamps
+        // as the initiate request; the receiver reads them from the complete
+        // headers (rustfs/backlog#1953).
+        assert_eq!(options.internal.tagging_timestamp, source_internal.tagging_timestamp);
+        assert_eq!(options.internal.retention_timestamp, source_internal.retention_timestamp);
+        assert_eq!(options.internal.legalhold_timestamp, source_internal.legalhold_timestamp);
+
         // Absent source mtime must degrade to epoch (header suppressed), not
         // the AdvancedPutOptions default of now_utc() — that default would
         // stamp the replication time as the replica's mtime and break the
-        // multipart HEAD convergence.
-        let options_no_mtime = replication_complete_multipart_options("1024".to_string(), String::new(), None);
+        // multipart HEAD convergence. Unset category timestamps stay epoch so
+        // header() keeps suppressing them.
+        let options_no_mtime =
+            replication_complete_multipart_options("1024".to_string(), String::new(), None, &AdvancedPutOptions::default());
         assert_eq!(options_no_mtime.internal.source_mtime.unix_timestamp(), 0);
+        assert_eq!(options_no_mtime.internal.tagging_timestamp.unix_timestamp(), 0);
+        assert_eq!(options_no_mtime.internal.retention_timestamp.unix_timestamp(), 0);
+        assert_eq!(options_no_mtime.internal.legalhold_timestamp.unix_timestamp(), 0);
 
         assert_eq!(
             get_header_map(&options.user_metadata, SUFFIX_REPLICATION_ACTUAL_OBJECT_SIZE).as_deref(),

crates/ecstore/src/set_disk/mod.rs

@@ -47,6 +47,7 @@ use crate::bucket::metadata_sys;
 use crate::bucket::metadata_sys::ObjectLockConfigState;
 use crate::bucket::object_lock::objectlock_sys::{
     check_object_lock_for_deletion_with_config, check_object_lock_for_deletion_with_state, check_retention_for_modification,
+    replication_write_may_pass_worm_gate,
 };
 use crate::bucket::replication::{
     ReplicateDecision, ReplicationObjectBridge, ReplicationState, ReplicationStatusType, VersionPurgeStatusType,

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

@@ -2223,6 +2223,57 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
             fi.set_data_moved();
         }
 
+        // Receiver-side LWW (rustfs/backlog#1953): the multipart replication
+        // transport carries the category values at CreateMultipartUpload (in
+        // the staged upload metadata) and the source category timestamps on
+        // the complete request. Read the destination version under the held
+        // object write lock and keep any category this site modified more
+        // recently. Read failures (version absent on first replication, quorum
+        // errors) keep today's overwrite semantics: failing the complete would
+        // loop through MRF, re-delivering the stale value forever.
+        if crate::set_disk::ops::object::replication_lww_applicable(opts)
+            && let Some(version_id) = fi.version_id
+        {
+            match self
+                .get_object_info(
+                    bucket,
+                    object,
+                    &ObjectOptions {
+                        version_id: Some(version_id.to_string()),
+                        no_lock: true,
+                        metadata_cache_safe: false,
+                        versioned: opts.versioned,
+                        version_suspended: opts.version_suspended,
+                        ..Default::default()
+                    },
+                )
+                .await
+            {
+                Ok(existing) => {
+                    let stored = crate::set_disk::ops::object::stored_replication_category_metadata(&existing);
+                    crate::set_disk::ops::object::merge_replication_metadata_lww(&mut fi.metadata, &stored, opts);
+                }
+                // Version absent: first replication of this version, nothing
+                // local to compare — the normal path, not a degraded one.
+                Err(err) if is_err_object_not_found(&err) || is_err_version_not_found(&err) => {}
+                Err(err) => {
+                    // Degraded path: without the stored state the inbound
+                    // metadata is applied unchanged — exactly the overwrite
+                    // LWW exists to prevent — so this must be operator-visible.
+                    warn!(
+                        component = LOG_COMPONENT_ECSTORE,
+                        subsystem = LOG_SUBSYSTEM_SET_DISK,
+                        bucket,
+                        object,
+                        version_id = %version_id,
+                        error = %err,
+                        state = "replication_lww_read_unavailable",
+                        "SetDisk multipart replication LWW read skipped; inbound metadata applied without comparison"
+                    );
+                }
+            }
+        }
+
         for meta in parts_metadatas.iter_mut() {
             if meta.has_valid_erasure_geometry() {
                 meta.size = fi.size;
@@ -6960,6 +7011,97 @@ mod tests {
                 .await
         }
 
+        /// Receiver-side LWW on the multipart replication transport
+        /// (rustfs/backlog#1953): a metadata-only replication of a multipart
+        /// source object rides CreateMultipartUpload (category values in the
+        /// upload metadata) + CompleteMultipartUpload (category timestamps in
+        /// the complete options). A stale inbound tagging timestamp must not
+        /// overwrite a newer locally-tagged destination version.
+        #[tokio::test]
+        #[serial]
+        async fn complete_multipart_upload_stale_replication_tags_keep_local() {
+            use rustfs_utils::http::headers::AMZ_OBJECT_TAGGING;
+            use rustfs_utils::http::{SUFFIX_TAGGING_TIMESTAMP, get_str};
+            use time::format_description::well_known::Rfc3339;
+
+            const T_OLD: &str = "2026-01-01T00:00:00Z";
+            const T_LOCAL: &str = "2026-02-01T00:00:00Z";
+
+            let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+            let bucket = "multipart-replication-lww-bucket";
+            let object = "object";
+            make_bucket_on_all(&disk_stores, bucket).await;
+
+            // Local destination version with newer tags.
+            let version_id = Uuid::new_v4();
+            let mut local_metadata = HashMap::new();
+            local_metadata.insert(AMZ_OBJECT_TAGGING.to_string(), "site=local".to_string());
+            rustfs_utils::http::insert_str(&mut local_metadata, SUFFIX_TAGGING_TIMESTAMP, T_LOCAL.to_string());
+            let mut local_reader = PutObjReader::from_vec(b"local body".to_vec());
+            set_disks
+                .put_object(
+                    bucket,
+                    object,
+                    &mut local_reader,
+                    &ObjectOptions {
+                        versioned: true,
+                        version_id: Some(version_id.to_string()),
+                        user_defined: local_metadata,
+                        // Explicit-version PUTs require the bucket Object Lock snapshot.
+                        object_lock_config_snapshot: Some(Arc::new(crate::set_disk::ObjectLockConfigSnapshot::new(
+                            crate::bucket::metadata_sys::ObjectLockConfigState::ConfirmedAbsent,
+                        ))),
+                        ..Default::default()
+                    },
+                )
+                .await
+                .expect("local versioned put should commit");
+
+            // Inbound replication upload carrying older tags for the same version.
+            let mut inbound_metadata = HashMap::new();
+            inbound_metadata.insert(AMZ_OBJECT_TAGGING.to_string(), "site=remote".to_string());
+            rustfs_utils::http::insert_str(&mut inbound_metadata, SUFFIX_TAGGING_TIMESTAMP, T_OLD.to_string());
+            let create_opts = ObjectOptions {
+                versioned: true,
+                user_defined: inbound_metadata,
+                ..Default::default()
+            };
+            let (upload_id, parts) =
+                stage_upload_with_create_opts(&set_disks, bucket, object, &payload(0x5a), &create_opts).await;
+            rewrite_staged_upload_version_id(&set_disks, bucket, object, &upload_id, Some(version_id)).await;
+
+            let complete_opts = ObjectOptions {
+                versioned: true,
+                replication_request: true,
+                replication_tagging_timestamp: Some(OffsetDateTime::parse(T_OLD, &Rfc3339).expect("test timestamp should parse")),
+                ..Default::default()
+            };
+            set_disks
+                .clone()
+                .complete_multipart_upload(bucket, object, &upload_id, parts, &complete_opts)
+                .await
+                .expect("replication multipart completion should succeed even when a category keeps local values");
+
+            let info = set_disks
+                .get_object_info(
+                    bucket,
+                    object,
+                    &ObjectOptions {
+                        versioned: true,
+                        version_id: Some(version_id.to_string()),
+                        ..Default::default()
+                    },
+                )
+                .await
+                .expect("completed version should be readable");
+            assert_eq!(
+                info.user_tags.as_str(),
+                "site=local",
+                "older inbound multipart tags must not overwrite newer local tags"
+            );
+            assert_eq!(get_str(&info.user_defined, SUFFIX_TAGGING_TIMESTAMP).as_deref(), Some(T_LOCAL));
+        }
+
         #[tokio::test]
         #[serial]
         async fn complete_multipart_upload_assigns_completion_version_id() {

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

@@ -1880,6 +1880,110 @@ fn delete_file_info_with_replication_transport_metadata(fi: &FileInfo) -> FileIn
     transported
 }
 
+/// True when an authorized replication write carries at least one per-category
+/// source timestamp, i.e. receiver-side LWW has something to judge.
+pub(in crate::set_disk) fn replication_lww_applicable(opts: &ObjectOptions) -> bool {
+    opts.replication_request
+        && (opts.replication_tagging_timestamp.is_some()
+            || opts.replication_retention_timestamp.is_some()
+            || opts.replication_legalhold_timestamp.is_some())
+}
+
+/// The stored per-category state of a destination version, as compared by
+/// [`merge_replication_metadata_lww`]. `ObjectInfo::from_file_info`
+/// externalizes tags into `user_tags` (stripping the metadata key), so the
+/// tag value is folded back into map form here.
+pub(in crate::set_disk) fn stored_replication_category_metadata(existing: &ObjectInfo) -> HashMap<String, String> {
+    let mut stored = (*existing.user_defined).clone();
+    if !existing.user_tags.is_empty() {
+        stored.insert(rustfs_utils::http::headers::AMZ_OBJECT_TAGGING.to_string(), (*existing.user_tags).clone());
+    }
+    stored
+}
+
+/// Receiver-side last-writer-wins for authorized replication writes
+/// (rustfs/backlog#1953, audit A4/P1-6). Metadata-only replication reuses the
+/// whole-object transports, so in active-active topologies an inbound write
+/// carries the source's tags / retention / legal hold verbatim and would
+/// otherwise overwrite a category the destination modified more recently —
+/// both sites end up permanently diverged while reporting COMPLETED.
+///
+/// Judged per category, only when the inbound request carries that category's
+/// source timestamp (`ObjectOptions::replication_*_timestamp`):
+/// - stored timestamp newer than inbound: the local category values and
+///   timestamp are kept; the rest of the write proceeds per the inbound
+///   metadata and the object-level result stays successful (failing the write
+///   instead would loop through MRF, re-delivering the stale value forever);
+/// - otherwise the inbound category wins and its internal timestamp key is
+///   pinned to the source-authored time — the PUT path re-stamps the
+///   object-lock timestamps with the receiver's clock
+///   (`parse_object_lock_retention` / `parse_object_lock_legal_hold` insert
+///   `now()` via `eval_metadata`), which would make the replica's clock the
+///   LWW authority and wedge later convergence;
+/// - no stored timestamp (pre-P1-6 data) or no inbound timestamp: the current
+///   overwrite behavior is preserved.
+///
+/// Returns whether `inbound` was modified. Callers must hold the object write
+/// lock so the stored values compared here are the ones being replaced.
+pub(in crate::set_disk) fn merge_replication_metadata_lww(
+    inbound: &mut HashMap<String, String>,
+    existing: &HashMap<String, String>,
+    opts: &ObjectOptions,
+) -> bool {
+    use rustfs_utils::http::headers::{
+        AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER, AMZ_OBJECT_LOCK_MODE_LOWER, AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER, AMZ_OBJECT_TAGGING,
+    };
+    use rustfs_utils::http::metadata_compat::{
+        SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, SUFFIX_TAGGING_TIMESTAMP, get_str,
+        remove_str,
+    };
+    use time::format_description::well_known::Rfc3339;
+
+    let categories: [(Option<OffsetDateTime>, &str, &[&str]); 3] = [
+        (opts.replication_tagging_timestamp, SUFFIX_TAGGING_TIMESTAMP, &[AMZ_OBJECT_TAGGING]),
+        (
+            opts.replication_retention_timestamp,
+            SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP,
+            &[AMZ_OBJECT_LOCK_MODE_LOWER, AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER],
+        ),
+        (
+            opts.replication_legalhold_timestamp,
+            SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP,
+            &[AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER],
+        ),
+    ];
+
+    let mut changed = false;
+    for (inbound_timestamp, timestamp_suffix, value_keys) in categories {
+        let Some(inbound_timestamp) = inbound_timestamp else { continue };
+        let is_category_value_key = |key: &str| value_keys.iter().any(|value_key| key.eq_ignore_ascii_case(value_key));
+        let stored_timestamp = get_str(existing, timestamp_suffix).and_then(|value| OffsetDateTime::parse(&value, &Rfc3339).ok());
+        if stored_timestamp.is_some_and(|stored| stored > inbound_timestamp) {
+            inbound.retain(|key, _| !is_category_value_key(key));
+            remove_str(inbound, timestamp_suffix);
+            for (key, value) in existing {
+                if is_category_value_key(key) {
+                    inbound.insert(key.clone(), value.clone());
+                }
+            }
+            // Restore the winning timestamp via insert_str, not a verbatim key
+            // copy: a MinIO-written version may carry only the
+            // x-minio-internal- key, and the dual-key invariant requires every
+            // write to produce both keys.
+            if let Some(stored_value) = get_str(existing, timestamp_suffix) {
+                rustfs_utils::http::insert_str(inbound, timestamp_suffix, stored_value);
+            }
+            changed = true;
+        } else if let Ok(source_authored) = inbound_timestamp.format(&Rfc3339)
+            && get_str(inbound, timestamp_suffix).as_deref() != Some(source_authored.as_str())
+        {
+            rustfs_utils::http::insert_str(inbound, timestamp_suffix, source_authored);
+            changed = true;
+        }
+    }
+    changed
+}
+
 impl SetDisks {
     pub(in crate::set_disk) async fn persist_old_data_cleanup_receipts(
         &self,
@@ -2557,9 +2661,33 @@ impl SetDisks {
                         let object_lock_config = opts.object_lock_config_snapshot.as_deref().ok_or_else(|| {
                             Error::other("explicit-version PUT is missing its Object Lock configuration snapshot")
                         })?;
-                        if check_object_lock_for_deletion_with_state(object_lock_config.state(), &existing, false)?.is_some() {
+                        // The WORM gate protects the locked version from local
+                        // overwrites; an authorized replication write passes it
+                        // only when the LWW merge below will judge every
+                        // locking category (see
+                        // `replication_write_may_pass_worm_gate`). Gate first so
+                        // malformed lock metadata still fails closed.
+                        if check_object_lock_for_deletion_with_state(object_lock_config.state(), &existing, false)?.is_some()
+                            && !replication_write_may_pass_worm_gate(&existing.user_defined, opts)
+                        {
                             return Err(StorageError::PrefixAccessDenied(bucket.to_string(), object.to_string()));
                         }
+                        // Receiver-side LWW (rustfs/backlog#1953): reuse this
+                        // commit-lock read of the destination version so a
+                        // category (tags / retention / legal hold) modified
+                        // more recently on this site is kept instead of being
+                        // overwritten by the inbound replication metadata.
+                        if replication_lww_applicable(opts) {
+                            let stored = stored_replication_category_metadata(&existing);
+                            let mut merged = parts_metadatas[response_metadata_slot].metadata.clone();
+                            if merge_replication_metadata_lww(&mut merged, &stored, opts) {
+                                for (pfi, disk) in parts_metadatas.iter_mut().zip(shuffle_disks.iter()) {
+                                    if disk.is_some() {
+                                        pfi.metadata = merged.clone();
+                                    }
+                                }
+                            }
+                        }
                     }
                     Err(err) if is_err_object_not_found(&err) || is_err_version_not_found(&err) => {}
                     Err(err) => return Err(err),
@@ -7887,6 +8015,540 @@ mod replication_quota_safety_tests {
     }
 }
 
+#[cfg(test)]
+mod replication_lww_tests {
+    //! Receiver-side LWW for authorized replication writes (rustfs/backlog#1953,
+    //! audit A4/P1-6): an inbound replication PUT whose per-category timestamp
+    //! (tags / retention / legal hold) is older than the destination version's
+    //! stored timestamp must keep the local category values instead of
+    //! overwriting them; categories are judged independently and the write
+    //! itself still succeeds.
+
+    use super::hermetic_set_disks_support::hermetic_set_disks_isolated as hermetic_set_disks;
+    use super::*;
+    use crate::storage_api_contracts::object::{ObjectIO as _, ObjectOperations as _};
+    use rustfs_utils::http::headers::{
+        AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER, AMZ_OBJECT_LOCK_MODE_LOWER, AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER, AMZ_OBJECT_TAGGING,
+    };
+    use rustfs_utils::http::{
+        SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, SUFFIX_TAGGING_TIMESTAMP, get_str,
+        insert_str,
+    };
+    use time::format_description::well_known::Rfc3339;
+
+    const T_OLD: &str = "2026-01-01T00:00:00Z";
+    const T_LOCAL: &str = "2026-02-01T00:00:00Z";
+    const T_NEW: &str = "2026-03-01T00:00:00Z";
+
+    fn parse_ts(value: &str) -> OffsetDateTime {
+        OffsetDateTime::parse(value, &Rfc3339).expect("test timestamp should parse")
+    }
+
+    async fn make_bucket(disks: &[DiskStore], bucket: &str) {
+        for disk in disks {
+            disk.make_volume(bucket).await.expect("bucket volume should be created");
+        }
+    }
+
+    async fn put_version(set_disks: &Arc<SetDisks>, bucket: &str, object: &str, version_id: &str, opts: &ObjectOptions) {
+        let mut reader = PutObjReader::from_vec(b"lww-body".to_vec());
+        set_disks
+            .put_object(bucket, object, &mut reader, opts)
+            .await
+            .expect("versioned put should commit");
+        assert_eq!(opts.version_id.as_deref(), Some(version_id));
+    }
+
+    fn versioned_opts(version_id: &str, user_defined: HashMap<String, String>) -> ObjectOptions {
+        ObjectOptions {
+            versioned: true,
+            version_id: Some(version_id.to_string()),
+            user_defined,
+            // Explicit-version PUTs require the bucket Object Lock snapshot.
+            object_lock_config_snapshot: Some(Arc::new(ObjectLockConfigSnapshot::new(
+                crate::bucket::metadata_sys::ObjectLockConfigState::ConfirmedAbsent,
+            ))),
+            ..Default::default()
+        }
+    }
+
+    /// Local state: version `version_id` with tags "site=local" stamped `T_LOCAL`.
+    async fn seed_local_tagged_version(set_disks: &Arc<SetDisks>, bucket: &str, object: &str, version_id: &str) {
+        let mut user_defined = HashMap::new();
+        user_defined.insert(AMZ_OBJECT_TAGGING.to_string(), "site=local".to_string());
+        insert_str(&mut user_defined, SUFFIX_TAGGING_TIMESTAMP, T_LOCAL.to_string());
+        put_version(set_disks, bucket, object, version_id, &versioned_opts(version_id, user_defined)).await;
+    }
+
+    fn inbound_tagging_opts(version_id: &str, tags: &str, timestamp: &str) -> ObjectOptions {
+        let mut user_defined = HashMap::new();
+        user_defined.insert(AMZ_OBJECT_TAGGING.to_string(), tags.to_string());
+        insert_str(&mut user_defined, SUFFIX_TAGGING_TIMESTAMP, timestamp.to_string());
+        ObjectOptions {
+            replication_request: true,
+            replication_tagging_timestamp: Some(parse_ts(timestamp)),
+            ..versioned_opts(version_id, user_defined)
+        }
+    }
+
+    async fn version_info(set_disks: &Arc<SetDisks>, bucket: &str, object: &str, version_id: &str) -> ObjectInfo {
+        set_disks
+            .get_object_info(bucket, object, &versioned_opts(version_id, HashMap::new()))
+            .await
+            .expect("version should be readable")
+    }
+
+    #[tokio::test]
+    async fn inbound_stale_tagging_keeps_newer_local_tags() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-tagging-stale";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        seed_local_tagged_version(&set_disks, bucket, object, &version_id).await;
+
+        put_version(
+            &set_disks,
+            bucket,
+            object,
+            &version_id,
+            &inbound_tagging_opts(&version_id, "site=remote", T_OLD),
+        )
+        .await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            info.user_tags.as_str(),
+            "site=local",
+            "older inbound tags must not overwrite newer local tags"
+        );
+        assert_eq!(
+            get_str(&info.user_defined, SUFFIX_TAGGING_TIMESTAMP).as_deref(),
+            Some(T_LOCAL),
+            "the winning local tagging timestamp must be preserved"
+        );
+    }
+
+    #[tokio::test]
+    async fn inbound_newer_tagging_overwrites_local_tags() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-tagging-newer";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        seed_local_tagged_version(&set_disks, bucket, object, &version_id).await;
+
+        put_version(
+            &set_disks,
+            bucket,
+            object,
+            &version_id,
+            &inbound_tagging_opts(&version_id, "site=remote", T_NEW),
+        )
+        .await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            info.user_tags.as_str(),
+            "site=remote",
+            "newer inbound tags must overwrite older local tags"
+        );
+        assert_eq!(get_str(&info.user_defined, SUFFIX_TAGGING_TIMESTAMP).as_deref(), Some(T_NEW));
+    }
+
+    #[tokio::test]
+    async fn inbound_wins_when_local_has_no_tagging_timestamp() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-tagging-no-local-ts";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        // Pre-P1-6 data: local tags without a stored tagging timestamp.
+        let mut user_defined = HashMap::new();
+        user_defined.insert(AMZ_OBJECT_TAGGING.to_string(), "site=local".to_string());
+        put_version(&set_disks, bucket, object, &version_id, &versioned_opts(&version_id, user_defined)).await;
+
+        put_version(
+            &set_disks,
+            bucket,
+            object,
+            &version_id,
+            &inbound_tagging_opts(&version_id, "site=remote", T_OLD),
+        )
+        .await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            info.user_tags.as_str(),
+            "site=remote",
+            "without a local timestamp the inbound category must win (pre-LWW data compatibility)"
+        );
+    }
+
+    #[tokio::test]
+    async fn categories_are_judged_independently() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-category-independent";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+
+        // Local: newer tags (T_LOCAL), older *cleared* retention (T_OLD) —
+        // timestamp key only, the shape a replicated retention clear stores.
+        // (An active local retention would already block the overwrite at the
+        // WORM gate; the LWW-reachable retention states are cleared/expired.)
+        let mut local = HashMap::new();
+        local.insert(AMZ_OBJECT_TAGGING.to_string(), "site=local".to_string());
+        insert_str(&mut local, SUFFIX_TAGGING_TIMESTAMP, T_LOCAL.to_string());
+        insert_str(&mut local, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, T_OLD.to_string());
+        put_version(&set_disks, bucket, object, &version_id, &versioned_opts(&version_id, local)).await;
+
+        // Inbound: older tags (T_OLD), newer retention (T_NEW).
+        let mut inbound = HashMap::new();
+        inbound.insert(AMZ_OBJECT_TAGGING.to_string(), "site=remote".to_string());
+        insert_str(&mut inbound, SUFFIX_TAGGING_TIMESTAMP, T_OLD.to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_MODE_LOWER.to_string(), "COMPLIANCE".to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER.to_string(), "2028-01-01T00:00:00Z".to_string());
+        insert_str(&mut inbound, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, T_NEW.to_string());
+        let opts = ObjectOptions {
+            replication_request: true,
+            replication_tagging_timestamp: Some(parse_ts(T_OLD)),
+            replication_retention_timestamp: Some(parse_ts(T_NEW)),
+            ..versioned_opts(&version_id, inbound)
+        };
+        put_version(&set_disks, bucket, object, &version_id, &opts).await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(info.user_tags.as_str(), "site=local", "the stale tagging category must keep local values");
+        assert_eq!(
+            info.user_defined.get(AMZ_OBJECT_LOCK_MODE_LOWER).map(String::as_str),
+            Some("COMPLIANCE"),
+            "the newer retention category must be applied in the same write"
+        );
+        assert_eq!(get_str(&info.user_defined, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP).as_deref(), Some(T_NEW));
+    }
+
+    #[tokio::test]
+    async fn inbound_stale_legal_hold_keeps_local_value() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-legalhold-stale";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+
+        // Local: legal hold released (OFF) at T_LOCAL. (A local hold that is
+        // still ON already blocks the overwrite at the WORM gate; the
+        // LWW-reachable divergence is a stale inbound ON resurrecting a hold
+        // that was released more recently on this site.)
+        let mut local = HashMap::new();
+        local.insert(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER.to_string(), "OFF".to_string());
+        insert_str(&mut local, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, T_LOCAL.to_string());
+        put_version(&set_disks, bucket, object, &version_id, &versioned_opts(&version_id, local)).await;
+
+        let mut inbound = HashMap::new();
+        inbound.insert(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER.to_string(), "ON".to_string());
+        insert_str(&mut inbound, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, T_OLD.to_string());
+        let opts = ObjectOptions {
+            replication_request: true,
+            replication_legalhold_timestamp: Some(parse_ts(T_OLD)),
+            ..versioned_opts(&version_id, inbound)
+        };
+        put_version(&set_disks, bucket, object, &version_id, &opts).await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            info.user_defined.get(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER).map(String::as_str),
+            Some("OFF"),
+            "a stale inbound legal hold must not resurrect a hold released more recently"
+        );
+        assert_eq!(
+            get_str(&info.user_defined, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP).as_deref(),
+            Some(T_LOCAL)
+        );
+    }
+
+    /// Dual-key invariant under LWW: a MinIO-written destination version may
+    /// carry only the x-minio-internal timestamp key; when the local category
+    /// wins, the restored map must still hold BOTH compatibility keys.
+    #[test]
+    fn local_win_restores_both_internal_timestamp_keys_for_minio_only_metadata() {
+        let mut inbound = HashMap::new();
+        inbound.insert(AMZ_OBJECT_TAGGING.to_string(), "site=remote".to_string());
+        insert_str(&mut inbound, SUFFIX_TAGGING_TIMESTAMP, T_OLD.to_string());
+        let existing = HashMap::from([
+            (AMZ_OBJECT_TAGGING.to_string(), "site=local".to_string()),
+            ("X-Minio-Internal-Tagging-Timestamp".to_string(), T_LOCAL.to_string()),
+        ]);
+        let opts = ObjectOptions {
+            replication_request: true,
+            replication_tagging_timestamp: Some(parse_ts(T_OLD)),
+            ..Default::default()
+        };
+
+        assert!(merge_replication_metadata_lww(&mut inbound, &existing, &opts));
+        assert_eq!(inbound.get(AMZ_OBJECT_TAGGING).map(String::as_str), Some("site=local"));
+        assert_eq!(
+            inbound.get("x-rustfs-internal-tagging-timestamp").map(String::as_str),
+            Some(T_LOCAL),
+            "the RustFS twin key must be materialized even when the source version only had the MinIO key"
+        );
+        assert_eq!(inbound.get("x-minio-internal-tagging-timestamp").map(String::as_str), Some(T_LOCAL));
+    }
+
+    /// When the inbound category wins, the stored timestamp must be the
+    /// source-authored one: the PUT path's eval_metadata stamps the
+    /// object-lock timestamps with the receiver's clock
+    /// (`parse_object_lock_retention`), which would otherwise make this
+    /// replica's clock the LWW authority and wedge later convergence.
+    #[tokio::test]
+    async fn inbound_win_pins_stored_timestamp_to_source_authored_value() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-retention-ts-pinned";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+
+        // Local cleared retention at T_OLD.
+        let mut local = HashMap::new();
+        insert_str(&mut local, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, T_OLD.to_string());
+        put_version(&set_disks, bucket, object, &version_id, &versioned_opts(&version_id, local)).await;
+
+        // Inbound newer retention: the source authored T_LOCAL, but the PUT
+        // path's eval_metadata stomped the metadata key with receiver-now
+        // (simulated by T_NEW here).
+        let mut inbound = HashMap::new();
+        inbound.insert(AMZ_OBJECT_LOCK_MODE_LOWER.to_string(), "GOVERNANCE".to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER.to_string(), "2028-01-01T00:00:00Z".to_string());
+        insert_str(&mut inbound, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, T_NEW.to_string());
+        let opts = ObjectOptions {
+            replication_request: true,
+            replication_retention_timestamp: Some(parse_ts(T_LOCAL)),
+            ..versioned_opts(&version_id, inbound)
+        };
+        put_version(&set_disks, bucket, object, &version_id, &opts).await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            get_str(&info.user_defined, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP).as_deref(),
+            Some(T_LOCAL),
+            "the stored category timestamp must be the source-authored time, not the receiver's clock"
+        );
+        assert_eq!(info.user_defined.get(AMZ_OBJECT_LOCK_MODE_LOWER).map(String::as_str), Some("GOVERNANCE"));
+    }
+
+    #[tokio::test]
+    async fn newer_local_tag_deletion_survives_stale_inbound_tags() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-tagging-deleted";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        // Local DeleteObjectTagging state: no tags, but a newer tagging timestamp.
+        let mut local = HashMap::new();
+        insert_str(&mut local, SUFFIX_TAGGING_TIMESTAMP, T_LOCAL.to_string());
+        put_version(&set_disks, bucket, object, &version_id, &versioned_opts(&version_id, local)).await;
+
+        put_version(
+            &set_disks,
+            bucket,
+            object,
+            &version_id,
+            &inbound_tagging_opts(&version_id, "site=remote", T_OLD),
+        )
+        .await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert!(
+            info.user_tags.is_empty(),
+            "a newer local tag deletion must not be resurrected by older inbound tags"
+        );
+        assert_eq!(get_str(&info.user_defined, SUFFIX_TAGGING_TIMESTAMP).as_deref(), Some(T_LOCAL));
+    }
+
+    /// Destination version under an active legal hold at `hold_timestamp`,
+    /// plus an active COMPLIANCE retention (no retention timestamp).
+    async fn seed_locked_version(set_disks: &Arc<SetDisks>, bucket: &str, object: &str, version_id: &str, hold_timestamp: &str) {
+        let mut local = HashMap::new();
+        local.insert(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER.to_string(), "ON".to_string());
+        insert_str(&mut local, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, hold_timestamp.to_string());
+        local.insert(AMZ_OBJECT_LOCK_MODE_LOWER.to_string(), "COMPLIANCE".to_string());
+        local.insert(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER.to_string(), "2099-01-01T00:00:00Z".to_string());
+        put_version(set_disks, bucket, object, version_id, &versioned_opts(version_id, local)).await;
+    }
+
+    /// Inbound legal-hold release from a source that also carries the (same)
+    /// COMPLIANCE retention; the sender stamps a source timestamp for every
+    /// category the source version has.
+    fn inbound_legal_hold_release_opts(version_id: &str, timestamp: &str) -> ObjectOptions {
+        let mut inbound = HashMap::new();
+        inbound.insert(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER.to_string(), "OFF".to_string());
+        insert_str(&mut inbound, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP, timestamp.to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_MODE_LOWER.to_string(), "COMPLIANCE".to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER.to_string(), "2099-01-01T00:00:00Z".to_string());
+        insert_str(&mut inbound, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP, T_OLD.to_string());
+        ObjectOptions {
+            replication_request: true,
+            replication_legalhold_timestamp: Some(parse_ts(timestamp)),
+            replication_retention_timestamp: Some(parse_ts(T_OLD)),
+            ..versioned_opts(version_id, inbound)
+        }
+    }
+
+    /// The source's lock state governs the replica: a legal-hold release (or a
+    /// retention change) can only reach this site through the authorized
+    /// replication write, so the commit-time WORM gate must not reject it
+    /// because the destination version is currently locked.
+    #[tokio::test]
+    async fn inbound_newer_legal_hold_release_updates_locked_version() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-locked-release-newer";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        seed_locked_version(&set_disks, bucket, object, &version_id, T_OLD).await;
+
+        put_version(
+            &set_disks,
+            bucket,
+            object,
+            &version_id,
+            &inbound_legal_hold_release_opts(&version_id, T_NEW),
+        )
+        .await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            info.user_defined.get(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER).map(String::as_str),
+            Some("OFF"),
+            "a newer source-side legal hold release must be applied to the locked replica"
+        );
+        assert_eq!(get_str(&info.user_defined, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP).as_deref(), Some(T_NEW));
+        assert_eq!(
+            info.user_defined.get(AMZ_OBJECT_LOCK_MODE_LOWER).map(String::as_str),
+            Some("COMPLIANCE"),
+            "the untouched retention category must survive the write"
+        );
+    }
+
+    /// Skipping the WORM gate for replication writes must not weaken LWW: a
+    /// stale inbound release still loses to a hold applied more recently here.
+    #[tokio::test]
+    async fn inbound_stale_legal_hold_release_keeps_newer_local_hold() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-locked-release-stale";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        seed_locked_version(&set_disks, bucket, object, &version_id, T_LOCAL).await;
+
+        put_version(
+            &set_disks,
+            bucket,
+            object,
+            &version_id,
+            &inbound_legal_hold_release_opts(&version_id, T_OLD),
+        )
+        .await;
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(
+            info.user_defined.get(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER).map(String::as_str),
+            Some("ON"),
+            "a stale inbound release must not lift a hold applied more recently on this site"
+        );
+        assert_eq!(
+            get_str(&info.user_defined, SUFFIX_OBJECTLOCK_LEGALHOLD_TIMESTAMP).as_deref(),
+            Some(T_LOCAL)
+        );
+    }
+
+    /// A replication write that carries no source decision for a locking
+    /// category (here: tags changed at a source that never held the object)
+    /// must not lift the destination's hold by replacing the metadata
+    /// unjudged; it stays WORM-rejected like a local overwrite.
+    #[tokio::test]
+    async fn inbound_without_legal_hold_timestamp_stays_rejected_on_held_version() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-locked-unjudged-category";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        seed_locked_version(&set_disks, bucket, object, &version_id, T_OLD).await;
+
+        let mut inbound = HashMap::new();
+        inbound.insert(AMZ_OBJECT_TAGGING.to_string(), "k=v".to_string());
+        insert_str(&mut inbound, SUFFIX_TAGGING_TIMESTAMP, T_NEW.to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_MODE_LOWER.to_string(), "COMPLIANCE".to_string());
+        inbound.insert(AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE_LOWER.to_string(), "2099-01-01T00:00:00Z".to_string());
+        let opts = ObjectOptions {
+            replication_request: true,
+            replication_tagging_timestamp: Some(parse_ts(T_NEW)),
+            replication_retention_timestamp: Some(parse_ts(T_NEW)),
+            replication_legalhold_timestamp: None,
+            ..versioned_opts(&version_id, inbound)
+        };
+        let mut reader = PutObjReader::from_vec(b"lww-body".to_vec());
+        let err = set_disks
+            .put_object(bucket, object, &mut reader, &opts)
+            .await
+            .expect_err("a replication write without the legal-hold source timestamp must stay rejected");
+        assert!(matches!(err, StorageError::PrefixAccessDenied(_, _)), "unexpected error: {err}");
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(info.user_defined.get(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER).map(String::as_str), Some("ON"));
+    }
+
+    /// The gate runs before the replication bypass, so malformed persisted
+    /// lock metadata still fails closed for an authorized replication write.
+    #[tokio::test]
+    async fn replication_write_on_malformed_lock_metadata_still_fails_closed() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-locked-malformed";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        let mut local = HashMap::new();
+        local.insert(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER.to_string(), "MAYBE".to_string());
+        put_version(&set_disks, bucket, object, &version_id, &versioned_opts(&version_id, local)).await;
+
+        let mut reader = PutObjReader::from_vec(b"lww-body".to_vec());
+        let err = set_disks
+            .put_object(bucket, object, &mut reader, &inbound_legal_hold_release_opts(&version_id, T_NEW))
+            .await
+            .expect_err("malformed persisted lock metadata must fail the replication write closed");
+        assert!(!matches!(err, StorageError::PrefixAccessDenied(_, _)), "unexpected error: {err}");
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(info.user_defined.get(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER).map(String::as_str), Some("MAYBE"));
+    }
+
+    /// The bypass is scoped to authorized replication writes: the same
+    /// explicit-version PUT without `replication_request` stays WORM-rejected.
+    #[tokio::test]
+    async fn non_replication_overwrite_of_locked_version_is_still_rejected() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "lww-locked-plain-put";
+        let object = "object";
+        let version_id = Uuid::new_v4().to_string();
+        make_bucket(&disk_stores, bucket).await;
+        seed_locked_version(&set_disks, bucket, object, &version_id, T_OLD).await;
+
+        let opts = ObjectOptions {
+            replication_request: false,
+            ..inbound_legal_hold_release_opts(&version_id, T_NEW)
+        };
+        let mut reader = PutObjReader::from_vec(b"lww-body".to_vec());
+        let err = set_disks
+            .put_object(bucket, object, &mut reader, &opts)
+            .await
+            .expect_err("a non-replication overwrite of a locked version must stay rejected");
+        assert!(matches!(err, StorageError::PrefixAccessDenied(_, _)), "unexpected error: {err}");
+
+        let info = version_info(&set_disks, bucket, object, &version_id).await;
+        assert_eq!(info.user_defined.get(AMZ_OBJECT_LOCK_LEGAL_HOLD_LOWER).map(String::as_str), Some("ON"));
+    }
+}
+
 #[cfg(test)]
 mod inline_put_commit_path_tests {
     use super::hermetic_set_disks_support::hermetic_set_disks_isolated as hermetic_set_disks;
@@ -13873,6 +14535,72 @@ mod put_object_tmp_cleanup_tests {
         assert_eq!(body, original_body);
     }
 
+    /// A local PutObjectRetention / PutObjectLegalHold clear persists empty
+    /// lock keys (`parse_object_lock_retention`). The commit-time WORM gate
+    /// must read that as unlocked: an explicit-version PUT (the inbound
+    /// replication transport) and a version delete both have to succeed
+    /// (rustfs/backlog#1953).
+    #[tokio::test]
+    async fn explicit_version_overwrite_and_delete_succeed_after_local_lock_clear() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "put-explicit-version-cleared-lock";
+        let object = "object";
+        for disk in &disk_stores {
+            disk.make_volume(bucket).await.expect("bucket volume should be created");
+        }
+
+        let mut initial_reader = PutObjReader::from_vec(b"original".to_vec());
+        let initial = set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut initial_reader,
+                &ObjectOptions {
+                    versioned: true,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("initial version should be written");
+        let version_id = initial
+            .version_id
+            .expect("versioned PUT should return a version ID")
+            .to_string();
+        let version_opts = ObjectOptions {
+            versioned: true,
+            version_id: Some(version_id.clone()),
+            delete_replication_config_snapshot: Some(Arc::new(DeleteReplicationConfigSnapshot::default())),
+            object_lock_config_snapshot: Some(Arc::new(ObjectLockConfigSnapshot::new(ObjectLockConfigState::ConfirmedAbsent))),
+            ..Default::default()
+        };
+        set_disks
+            .put_object_metadata(
+                bucket,
+                object,
+                &ObjectOptions {
+                    eval_metadata: Some(HashMap::from([
+                        (X_AMZ_OBJECT_LOCK_MODE.as_str().to_string(), String::new()),
+                        (X_AMZ_OBJECT_LOCK_RETAIN_UNTIL_DATE.as_str().to_string(), String::new()),
+                        (X_AMZ_OBJECT_LOCK_LEGAL_HOLD.as_str().to_string(), String::new()),
+                    ])),
+                    ..version_opts.clone()
+                },
+            )
+            .await
+            .expect("cleared lock metadata should be written");
+
+        let mut replacement = PutObjReader::from_vec(b"replacement".to_vec());
+        set_disks
+            .put_object(bucket, object, &mut replacement, &version_opts)
+            .await
+            .expect("explicit-version PUT must not be wedged by cleared lock metadata");
+
+        set_disks
+            .delete_object(bucket, object, version_opts)
+            .await
+            .expect("version delete must not be wedged by cleared lock metadata");
+    }
+
     #[tokio::test]
     async fn version_only_copy_checks_the_destination_version_object_lock() {
         let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;

crates/replication/src/config.rs

@@ -265,160 +265,6 @@ pub fn active_replication_rule_destination_arns(config: &ReplicationConfiguratio
     arns
 }
 
-/// Deployment id extracted from a site-replication target ARN
-/// (`arn:{rustfs|minio}:replication::<deployment-id>:<bucket>`), or `None`
-/// for an operator-authored ARN.
-pub fn replication_target_arn_deployment_id(arn: &str) -> Option<String> {
-    let parts: Vec<_> = arn.split(':').collect();
-    if parts.len() == 6
-        && parts[0] == "arn"
-        && matches!(parts[1], "rustfs" | "minio")
-        && parts[2] == "replication"
-        && !parts[4].is_empty()
-    {
-        return Some(parts[4].to_string());
-    }
-
-    None
-}
-
-/// Rule id prefix the site-replication reconciler stamps on the rules it
-/// derives (`site-repl-<peer deployment id>`).
-pub const SITE_REPLICATION_RULE_ID_PREFIX: &str = "site-repl-";
-
-/// Whether `rule` carries a site-replication rule id (`site-repl-*`). The
-/// reconciler and the peer ingestion path treat the whole namespace as theirs
-/// on a site-replication bucket; the S3 edit path must not — rule ids are not
-/// reserved, so see [`site_replication_rule_deployment_id`].
-pub fn is_site_replication_rule(rule: &ReplicationRule) -> bool {
-    rule.id
-        .as_deref()
-        .is_some_and(|id| id.starts_with(SITE_REPLICATION_RULE_ID_PREFIX))
-}
-
-/// Deployment id of the peer a reconciler-derived rule replicates to, or
-/// `None` for any other rule. The reconciler builds each rule from one peer:
-/// the id is `site-repl-<deployment id>` and the destination ARN names that
-/// same deployment id — an operator-authored `site-repl-user` rule, or a
-/// `site-repl-<peer>` id pasted onto a foreign ARN, fails the agreement check.
-/// Callers that know the current peer set must also confirm the id is one of
-/// those peers before treating the rule as reconciler-owned.
-pub fn site_replication_rule_deployment_id(rule: &ReplicationRule) -> Option<&str> {
-    let deployment_id = rule.id.as_deref()?.strip_prefix(SITE_REPLICATION_RULE_ID_PREFIX)?;
-    (!deployment_id.is_empty()
-        && replication_target_arn_deployment_id(&rule.destination.bucket).as_deref() == Some(deployment_id))
-    .then_some(deployment_id)
-}
-
-/// Whether `rule` is one the local reconciler derived for a current remote
-/// site-replication peer in `peer_deployment_ids`. With an empty peer set
-/// (site replication disabled) nothing qualifies, so a bucket outside site
-/// replication keeps the verbatim S3 put/delete semantics.
-pub fn is_reconciler_owned_site_replication_rule(rule: &ReplicationRule, peer_deployment_ids: &HashSet<String>) -> bool {
-    site_replication_rule_deployment_id(rule).is_some_and(|deployment_id| peer_deployment_ids.contains(deployment_id))
-}
-
-/// Merge an incoming replication config into the local one.
-///
-/// `site-repl-*` rules encode the *holder's* outbound direction — their
-/// destination ARN names another site — so applying an external rule set
-/// verbatim replaces the local reverse rule with one this site can never
-/// satisfy (no bucket target backs it) and replication silently stops. Only
-/// operator-authored rules travel: the site-replication peer ingestion path
-/// and the S3 put/delete-bucket-replication path both keep the local site's
-/// `site-repl-*` rules through this merge. `incoming == None` models a
-/// delete of the operator-authored rules.
-pub fn merge_incoming_replication_config(
-    incoming: Option<ReplicationConfiguration>,
-    local: Option<ReplicationConfiguration>,
-) -> Option<ReplicationConfiguration> {
-    merge_replication_config_keeping_site_rules(incoming, local, is_site_replication_rule)
-}
-
-/// [`merge_incoming_replication_config`] for the S3 put/delete-bucket-replication
-/// path (issue #1948): only rules the local reconciler derived for a current
-/// peer in `peer_deployment_ids` survive as site rules; every other stored
-/// rule — including an operator-authored `site-repl-*` id — is operator state
-/// that the request replaces or deletes. An incoming rule whose id is a
-/// current peer's `site-repl-<id>` is dropped whatever its ARN: accepting it
-/// would duplicate the reconciler rule's id.
-pub fn merge_user_replication_config(
-    incoming: Option<ReplicationConfiguration>,
-    local: Option<ReplicationConfiguration>,
-    peer_deployment_ids: &HashSet<String>,
-) -> Option<ReplicationConfiguration> {
-    let incoming = incoming.map(|mut config| {
-        config.rules.retain(|rule| {
-            !rule
-                .id
-                .as_deref()
-                .and_then(|id| id.strip_prefix(SITE_REPLICATION_RULE_ID_PREFIX))
-                .is_some_and(|deployment_id| peer_deployment_ids.contains(deployment_id))
-        });
-        config
-    });
-    merge_replication_config_keeping_site_rules(incoming, local, |rule| {
-        is_reconciler_owned_site_replication_rule(rule, peer_deployment_ids)
-    })
-}
-
-fn merge_replication_config_keeping_site_rules(
-    incoming: Option<ReplicationConfiguration>,
-    local: Option<ReplicationConfiguration>,
-    is_site_rule: impl Fn(&ReplicationRule) -> bool,
-) -> Option<ReplicationConfiguration> {
-    let incoming_role = incoming.as_ref().map(|config| config.role.clone()).unwrap_or_default();
-    // Operator rules first, then the local site rules — the same order the
-    // site-replication reconciler produces, so its no-op check matches and
-    // the bucket metadata is written once per broadcast, not twice.
-    let mut rules: Vec<ReplicationRule> = incoming
-        .into_iter()
-        .flat_map(|config| config.rules)
-        .filter(|rule| !is_site_rule(rule))
-        .collect();
-    rules.extend(local.into_iter().flat_map(|config| config.rules).filter(&is_site_rule));
-
-    if rules.is_empty() {
-        return None;
-    }
-
-    assign_site_replication_rule_priorities(&mut rules, &is_site_rule);
-
-    // A site-replication ARN in `role` is the sender's, and the reconciler's
-    // per-peer target lookup reads it — carrying it over would pin the
-    // receiver's targets to the sender's identity.
-    let role = match replication_target_arn_deployment_id(&incoming_role) {
-        Some(_) => String::new(),
-        None => incoming_role,
-    };
-
-    Some(ReplicationConfiguration { role, rules })
-}
-
-/// Give the site rules in `rules` the lowest priorities no operator rule uses,
-/// in rule order, leaving every operator rule's priority untouched. Operator
-/// priorities decide which rule wins per target, so they are part of the
-/// submitted policy; site rules are derived state and only need to be unique
-/// (`validate_replication_config_structure` rejects duplicates). The result
-/// is a pure function of the rule list, so the site-replication reconciler,
-/// the peer ingestion merge and the S3 edit merge all converge on the same
-/// bytes and the reconciler's no-op check holds.
-pub fn assign_site_replication_rule_priorities(rules: &mut [ReplicationRule], is_site_rule: impl Fn(&ReplicationRule) -> bool) {
-    let taken: HashSet<i32> = rules
-        .iter()
-        .filter(|rule| !is_site_rule(rule))
-        .map(|rule| rule.priority.unwrap_or(0))
-        .collect();
-    let mut next = 1;
-    for rule in rules.iter_mut().filter(|rule| is_site_rule(rule)) {
-        while taken.contains(&next) {
-            next += 1;
-        }
-        rule.priority = Some(next);
-        next = next.saturating_add(1);
-    }
-}
-
 pub fn replication_target_arns(config: &ReplicationConfiguration) -> HashSet<String> {
     let role = config.role.trim();
     if !role.is_empty() {
@@ -1693,103 +1539,4 @@ mod tests {
             "the child rule must win for target A while the overlapping child target B remains eligible"
         );
     }
-
-    #[test]
-    fn site_replication_rule_deployment_id_requires_id_and_arn_agreement() {
-        let reconciler_rule = replication_rule("site-repl-peer-dep", "arn:rustfs:replication::peer-dep:bucket");
-        assert_eq!(site_replication_rule_deployment_id(&reconciler_rule), Some("peer-dep"));
-
-        // A remote-target ARN carries the remote's deployment id (or a random
-        // uuid), never the operator's rule id.
-        let operator_named_rule = replication_rule("site-repl-user", "arn:minio:replication:us-east-1:2f1c-remote:bucket");
-        assert_eq!(site_replication_rule_deployment_id(&operator_named_rule), None);
-
-        let foreign_arn = replication_rule("site-repl-peer-dep", "arn:rustfs:replication::other-dep:bucket");
-        assert_eq!(site_replication_rule_deployment_id(&foreign_arn), None);
-
-        let empty_id = replication_rule("site-repl-", "arn:rustfs:replication::peer-dep:bucket");
-        assert_eq!(site_replication_rule_deployment_id(&empty_id), None);
-
-        let peers = HashSet::from(["peer-dep".to_string()]);
-        assert!(is_reconciler_owned_site_replication_rule(&reconciler_rule, &peers));
-        assert!(!is_reconciler_owned_site_replication_rule(&reconciler_rule, &HashSet::new()));
-        let removed_peer = replication_rule("site-repl-gone-dep", "arn:rustfs:replication::gone-dep:bucket");
-        assert!(!is_reconciler_owned_site_replication_rule(&removed_peer, &peers));
-    }
-
-    // The merge must not rewrite the operator's priorities: with the
-    // priority-5 rule listed first and renumbered 1 then 2, the priority-1
-    // delete-marker-disabled rule would win the replication decision.
-    #[test]
-    fn merge_keeps_operator_priorities_and_replication_decision() {
-        let user_arn = "arn:minio:replication:us-east-1:2f1c-remote:bucket";
-        let peer_arn = "arn:rustfs:replication::peer-dep:bucket";
-        let incoming = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![
-                delete_marker_rule("dm-enabled", user_arn, "logs/", 5, true),
-                delete_marker_rule("dm-disabled", user_arn, "logs/2026/", 1, false),
-            ],
-        };
-        let mut site_rule = delete_marker_rule("site-repl-peer-dep", peer_arn, "", 7, true);
-        site_rule.prefix = None;
-        let local = structure_config(vec![site_rule]);
-        let opts = ObjectOpts {
-            name: "logs/2026/app.log".to_string(),
-            op_type: ReplicationType::Delete,
-            delete_marker: true,
-            version_id: None,
-            ..Default::default()
-        };
-        let submitted: Vec<_> = incoming.filter_target_replication_decisions(&opts);
-
-        let peers = HashSet::from(["peer-dep".to_string()]);
-        let merged = merge_user_replication_config(Some(incoming.clone()), Some(local.clone()), &peers).expect("rules");
-
-        let priorities: Vec<_> = merged
-            .rules
-            .iter()
-            .map(|rule| (rule.id.as_deref().unwrap(), rule.priority))
-            .collect();
-        assert_eq!(
-            priorities,
-            vec![
-                ("dm-enabled", Some(5)),
-                ("dm-disabled", Some(1)),
-                ("site-repl-peer-dep", Some(2))
-            ],
-            "operator priorities are kept verbatim; the site rule takes the lowest free slot"
-        );
-        assert!(validate_replication_config_structure(&merged).is_ok());
-        let mut decisions = merged.filter_target_replication_decisions(&opts);
-        decisions.retain(|(arn, _)| arn == user_arn);
-        assert_eq!(decisions, submitted, "the merged config must replicate exactly as the operator submitted");
-        assert_eq!(decisions, vec![(user_arn.to_string(), true)]);
-
-        // The peer ingestion merge follows the same rule.
-        let merged = merge_incoming_replication_config(Some(incoming), Some(local)).expect("rules");
-        let priorities: Vec<_> = merged.rules.iter().map(|rule| rule.priority).collect();
-        assert_eq!(priorities, vec![Some(5), Some(1), Some(2)]);
-    }
-
-    #[test]
-    fn site_rule_priorities_skip_every_operator_priority() {
-        let mut rules = vec![
-            delete_marker_rule("a", "arn:a", "", 2, true),
-            delete_marker_rule("site-repl-x", "arn:rustfs:replication::x:b", "", 9, true),
-            delete_marker_rule("b", "arn:a", "", 1, true),
-            delete_marker_rule("site-repl-y", "arn:rustfs:replication::y:b", "", 9, true),
-            delete_marker_rule("c", "arn:a", "", 4, true),
-        ];
-        assign_site_replication_rule_priorities(&mut rules, is_site_replication_rule);
-        let priorities: Vec<_> = rules.iter().map(|rule| rule.priority).collect();
-        assert_eq!(priorities, vec![Some(2), Some(3), Some(1), Some(5), Some(4)]);
-        assert!(validate_replication_config_structure(&structure_config(rules.clone())).is_ok());
-
-        // Idempotent, so the reconciler's pass over an already-merged config
-        // is a byte-stable no-op rather than a rewrite every period.
-        let settled = rules.clone();
-        assign_site_replication_rule_priorities(&mut rules, is_site_replication_rule);
-        assert_eq!(rules, settled);
-    }
 }

crates/replication/src/lib.rs

@@ -32,11 +32,9 @@ pub use config::{
     ObjectOpts, REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION, REMOTE_TARGET_UNSUPPORTED_FIELDS, REMOTE_TARGET_WRITABLE_FIELDS,
     REPLICATION_CAPABILITY_CONTRACT_VERSION, REPLICATION_READ_ONLY_HISTORICAL_FIELDS, REPLICATION_WRITABLE_FIELDS,
     ReplicationConfigStructureError, ReplicationConfigurationExt, ReplicationTargetValidationError,
-    active_replication_rule_destination_arns, assign_site_replication_rule_priorities, invalid_replication_config_status_field,
-    is_reconciler_owned_site_replication_rule, is_site_replication_rule, merge_incoming_replication_config,
-    merge_user_replication_config, replication_target_arn_deployment_id, replication_target_arns,
-    should_remove_replication_target, site_replication_rule_deployment_id, unsupported_replication_config_field,
-    validate_replication_config_structure, validate_replication_config_target_arns,
+    active_replication_rule_destination_arns, invalid_replication_config_status_field, replication_target_arns,
+    should_remove_replication_target, unsupported_replication_config_field, validate_replication_config_structure,
+    validate_replication_config_target_arns,
 };
 pub use delete::{
     DeletedObjectReplicationInfo, delete_marker_purge_mrf_entry, delete_marker_purge_version_id,

rustfs/src/admin/handlers/site_replication.rs

@@ -31,10 +31,6 @@ use crate::admin::storage_api::bucket::metadata::{
 use crate::admin::storage_api::bucket::metadata_sys;
 use crate::admin::storage_api::bucket::quota::BucketQuota;
 use crate::admin::storage_api::bucket::replication;
-use crate::admin::storage_api::bucket::replication::{
-    assign_site_replication_rule_priorities, is_site_replication_rule, merge_incoming_replication_config,
-    replication_target_arn_deployment_id,
-};
 use crate::admin::storage_api::bucket::target::{ARN, BucketTarget, BucketTargetType, BucketTargets, Credentials};
 use crate::admin::storage_api::bucket::target_sys::BucketTargetSys;
 use crate::admin::storage_api::bucket::utils::{deserialize, serialize};
@@ -1121,36 +1117,6 @@ async fn load_site_replication_state() -> S3Result<SiteReplicationState> {
     }
 }
 
-/// Whether this deployment participates in site replication (two or more
-/// peers in the persisted state). Read by the S3 interface layer to gate
-/// replication-config edits (MinIO `ErrReplicationDenyEditError` semantics,
-/// issue #1948); a state-read failure propagates so the gate fails closed.
-pub(crate) async fn site_replication_enabled() -> S3Result<bool> {
-    Ok(load_site_replication_state().await?.enabled())
-}
-
-/// Deployment ids of the remote peers the reconciler derives a
-/// `site-repl-<id>` rule for on every bucket (the same peer filter as
-/// `build_site_replication_config`); empty when site replication is not
-/// enabled. Read by the bucket usecase so an S3 replication-config edit keeps
-/// exactly the reconciler-owned rules (issue #1948); a state-read failure
-/// propagates so the edit fails closed.
-pub(crate) async fn site_replication_remote_peer_deployment_ids() -> S3Result<HashSet<String>> {
-    let state = load_site_replication_state().await?;
-    if !state.enabled() {
-        return Ok(HashSet::new());
-    }
-    let local_peer = current_local_runtime_peer(&state);
-    Ok(state
-        .peers
-        .values()
-        .filter(|peer| {
-            peer.deployment_id != local_peer.deployment_id && !same_identity_endpoint(&peer.endpoint, &local_peer.endpoint)
-        })
-        .map(|peer| peer.deployment_id.clone())
-        .collect())
-}
-
 async fn load_site_replication_state_no_lock(store: Arc<ECStore>) -> S3Result<SiteReplicationState> {
     match read_config_no_lock(store, SITE_REPLICATION_STATE_PATH).await {
         Ok(data) => parse_site_replication_state(&data),
@@ -7782,6 +7748,20 @@ fn bucket_target_deployment_id(target: &BucketTarget) -> Option<String> {
     replication_target_arn_deployment_id(&target.arn)
 }
 
+fn replication_target_arn_deployment_id(arn: &str) -> Option<String> {
+    let parts: Vec<_> = arn.split(':').collect();
+    if parts.len() == 6
+        && parts[0] == "arn"
+        && matches!(parts[1], "rustfs" | "minio")
+        && parts[2] == "replication"
+        && !parts[4].is_empty()
+    {
+        return Some(parts[4].to_string());
+    }
+
+    None
+}
+
 fn prune_removed_site_replication_bucket_targets(
     existing: BucketTargets,
     removed_deployment_ids: &HashSet<String>,
@@ -7806,6 +7786,10 @@ fn prune_removed_site_replication_bucket_targets(
     (BucketTargets { targets }, removed)
 }
 
+fn is_site_replication_rule(rule: &ReplicationRule) -> bool {
+    rule.id.as_deref().is_some_and(|id| id.starts_with("site-repl-"))
+}
+
 /// Whether every `site-repl-*` rule on this bucket resolves to a live remote target.
 ///
 /// The rule set alone cannot answer this: a rule can be perfectly formed while the endpoint
@@ -7831,6 +7815,52 @@ async fn site_replication_targets_online(bucket: &str, replication_config_xml: &
     true
 }
 
+/// Merge a peer's replication config into the local one.
+///
+/// `site-repl-*` rules encode the *sender's* outbound direction — their destination ARN
+/// names the receiver — so applying a peer's rule set verbatim replaces the receiver's
+/// reverse rule with one pointing at itself. No bucket target can satisfy that ARN
+/// (`reconcile_site_replication_bucket_targets` skips the local peer), so the receiver
+/// silently stops replicating back: the one-directional symptom. Only operator-authored
+/// rules travel between sites; each site owns its own `site-repl-*` rules.
+fn merge_incoming_replication_config(
+    incoming: Option<ReplicationConfiguration>,
+    local: Option<ReplicationConfiguration>,
+) -> Option<ReplicationConfiguration> {
+    let incoming_role = incoming.as_ref().map(|config| config.role.clone()).unwrap_or_default();
+    // Operator rules first, then the local site rules — the same order
+    // `ensure_site_replication_bucket_replication_config_with_runtime` produces, so its
+    // no-op check matches and the bucket metadata is written once per broadcast, not twice.
+    let mut rules: Vec<ReplicationRule> = incoming
+        .into_iter()
+        .flat_map(|config| config.rules)
+        .filter(|rule| !is_site_replication_rule(rule))
+        .collect();
+    rules.extend(
+        local
+            .into_iter()
+            .flat_map(|config| config.rules)
+            .filter(is_site_replication_rule),
+    );
+
+    if rules.is_empty() {
+        return None;
+    }
+
+    for (index, rule) in rules.iter_mut().enumerate() {
+        rule.priority = Some(i32::try_from(index + 1).unwrap_or(i32::MAX));
+    }
+
+    // A site-replication ARN in `role` is the sender's, and `site_replication_target_arns_by_peer`
+    // reads it — carrying it over would pin the receiver's targets to the sender's identity.
+    let role = match replication_target_arn_deployment_id(&incoming_role) {
+        Some(_) => String::new(),
+        None => incoming_role,
+    };
+
+    Some(ReplicationConfiguration { role, rules })
+}
+
 /// Merge a peer's ILM expiry document into the local lifecycle config.
 ///
 /// Mirrors MinIO's `mergeWithCurrentLCConfig` with one hardening: incoming
@@ -8169,7 +8199,9 @@ fn prune_removed_site_replication_rules(
         return (None, removed);
     }
 
-    assign_site_replication_rule_priorities(&mut config.rules, is_site_replication_rule);
+    for (index, rule) in config.rules.iter_mut().enumerate() {
+        rule.priority = Some(i32::try_from(index + 1).unwrap_or(i32::MAX));
+    }
 
     (Some(config), removed)
 }
@@ -8343,10 +8375,9 @@ async fn ensure_site_replication_bucket_replication_config_with_runtime(
         .cloned()
         .collect();
     rules.extend(desired.rules);
-    // Operator priorities are the operator's policy; only the derived rules
-    // take free slots, by the same function as the config merges so a merged
-    // write and this pass agree byte for byte.
-    assign_site_replication_rule_priorities(&mut rules, is_site_replication_rule);
+    for (index, rule) in rules.iter_mut().enumerate() {
+        rule.priority = Some(i32::try_from(index + 1).unwrap_or(i32::MAX));
+    }
 
     // Only a site-replication ARN in `role` is ours to drop — an operator-authored role is
     // part of the bucket's S3-visible configuration, and repairing a reverse rule must not
@@ -16969,7 +17000,7 @@ mod tests {
     }
 
     #[test]
-    fn test_prune_removed_site_replication_rules_removes_site_rule_and_keeps_operator_priority() {
+    fn test_prune_removed_site_replication_rules_removes_site_rule_and_reorders_priorities() {
         let removed_deployment_ids = HashSet::from(["removed-dep".to_string()]);
         let kept_rule = build_site_replication_rule("arn:rustfs:replication::kept-dep:photos", 3, "site-repl-kept-dep");
         let removed_rule = build_site_replication_rule("arn:rustfs:replication::removed-dep:photos", 1, "site-repl-removed-dep");
@@ -16986,9 +17017,9 @@ mod tests {
         assert!(updated.role.is_empty());
         assert_eq!(updated.rules.len(), 2);
         assert_eq!(updated.rules[0].id.as_deref(), Some("user-managed-rule"));
-        assert_eq!(updated.rules[0].priority, Some(9), "the operator's priority is policy and stays");
+        assert_eq!(updated.rules[0].priority, Some(1));
         assert_eq!(updated.rules[1].id.as_deref(), Some("site-repl-kept-dep"));
-        assert_eq!(updated.rules[1].priority, Some(1), "the derived rule moves to the lowest free slot");
+        assert_eq!(updated.rules[1].priority, Some(2));
     }
 
     #[test]

rustfs/src/admin/storage_api.rs

@@ -443,8 +443,6 @@ pub(crate) mod replication {
     pub(crate) use super::ecstore_bucket::replication::{
         REMOTE_TARGET_CAPABILITY_CONTRACT_VERSION, REMOTE_TARGET_UNSUPPORTED_FIELDS, REMOTE_TARGET_WRITABLE_FIELDS,
         REPLICATION_CAPABILITY_CONTRACT_VERSION, REPLICATION_READ_ONLY_HISTORICAL_FIELDS, REPLICATION_WRITABLE_FIELDS,
-        assign_site_replication_rule_priorities, is_site_replication_rule, merge_incoming_replication_config,
-        replication_target_arn_deployment_id,
     };
     pub(crate) type BucketReplicationResyncStatus = super::ecstore_bucket::replication::BucketReplicationResyncStatus;
     pub(crate) type BucketStats = super::ecstore_bucket::replication::BucketStats;

rustfs/src/app/bucket_usecase.rs

@@ -38,9 +38,9 @@ use super::storage_api::bucket_usecase::bucket::{
     metadata_sys,
     policy_sys::PolicySys,
     replication::{
-        ReplicationTargetValidationError, invalid_replication_config_status_field, merge_user_replication_config,
-        replication_target_arns, should_remove_replication_target, unsupported_replication_config_field,
-        validate_replication_config_structure, validate_replication_config_target_arns,
+        ReplicationTargetValidationError, invalid_replication_config_status_field, replication_target_arns,
+        should_remove_replication_target, unsupported_replication_config_field, validate_replication_config_structure,
+        validate_replication_config_target_arns,
     },
     target::{BucketTargetType, BucketTargets},
     utils::serialize,
@@ -66,7 +66,6 @@ use super::storage_api::bucket_usecase::{
 };
 use crate::admin::handlers::site_replication::{
     site_replication_bucket_meta_hook, site_replication_delete_bucket_hook, site_replication_make_bucket_hook,
-    site_replication_remote_peer_deployment_ids,
 };
 use crate::app::object_data_cache::invalidate_object_data_cache_bucket_after_delete;
 use crate::app::runtime_sources::{
@@ -624,52 +623,11 @@ async fn validate_bucket_replication_update(bucket: &str, config: &ReplicationCo
     validate_replication_config_targets(&targets, config)
 }
 
-/// Defense in depth for site-replication-managed buckets (issue #1948): an S3
-/// PutBucketReplication replaces the operator-authored rules but must not wipe
-/// the rules the reconciler derived for the current remote peers
-/// (`site_peer_deployment_ids`) — until its next pass (600s period) every
-/// peer link on this bucket would be silently dead. The same merge also drops
-/// incoming impostors of those rules. An empty peer set (site replication
-/// disabled) keeps the verbatim overwrite semantics: rule ids are not
-/// reserved, so an operator's own `site-repl-*` rule is ordinary state there.
-fn merge_user_replication_config_update(
-    incoming: ReplicationConfiguration,
-    existing: Option<ReplicationConfiguration>,
-    site_peer_deployment_ids: &HashSet<String>,
-) -> ReplicationConfiguration {
-    if site_peer_deployment_ids.is_empty() {
-        return incoming;
-    }
-    // `incoming` passed structure validation, so it holds at least one rule;
-    // `None` is only reachable when every incoming rule impersonates a
-    // reconciler rule, and then the stored reconciler rules are what remains.
-    merge_user_replication_config(Some(incoming.clone()), existing, site_peer_deployment_ids).unwrap_or(incoming)
-}
-
-/// Split of an S3 DeleteBucketReplication on the stored config (issue #1948):
-/// the operator-authored rules are removed, the rules the reconciler derived
-/// for the current remote peers survive (`None` means nothing survives and
-/// the config is deleted), and the returned ARNs are the ones whose bucket
-/// targets may be garbage-collected — never an ARN a surviving reconciler
-/// rule still points at.
-fn split_replication_config_for_user_delete(
-    config: ReplicationConfiguration,
-    site_peer_deployment_ids: &HashSet<String>,
-) -> (Option<ReplicationConfiguration>, HashSet<String>) {
-    let mut removable_arns = replication_target_arns(&config);
-    let remaining = merge_user_replication_config(None, Some(config), site_peer_deployment_ids);
-    if let Some(remaining) = remaining.as_ref() {
-        for rule in &remaining.rules {
-            removable_arns.remove(rule.destination.bucket.trim());
-        }
-    }
-    (remaining, removable_arns)
-}
-
-async fn replication_targets_without_arns(
+async fn replication_targets_without_config_targets(
     bucket: &str,
-    target_arns: &HashSet<String>,
+    config: &ReplicationConfiguration,
 ) -> S3Result<Option<(BucketTargets, usize)>> {
+    let target_arns = replication_target_arns(config);
     if target_arns.is_empty() {
         return Ok(None);
     }
@@ -680,7 +638,7 @@ async fn replication_targets_without_arns(
         Err(err) => return Err(ApiError::from(err).into()),
     };
 
-    let removed = remove_replication_targets_from_config_targets(&mut targets, target_arns);
+    let removed = remove_replication_targets_from_config_targets(&mut targets, &target_arns);
     if removed == 0 {
         return Ok(None);
     }
@@ -1646,30 +1604,15 @@ impl DefaultBucketUsecase {
             Err(StorageError::ConfigNotFound) => None,
             Err(err) => return Err(ApiError::from(err).into()),
         };
-        let (remaining_config, updated_targets) = if let Some(config) = replication_config.as_ref() {
-            let site_peers = site_replication_remote_peer_deployment_ids().await?;
-            let (remaining, removable_arns) = split_replication_config_for_user_delete(config.clone(), &site_peers);
-            let targets = replication_targets_without_arns(&bucket, &removable_arns).await?;
-            (remaining, targets)
+        let updated_targets = if let Some(config) = replication_config.as_ref() {
+            replication_targets_without_config_targets(&bucket, config).await?
         } else {
-            (None, None)
+            None
         };
 
-        match remaining_config {
-            // Site-replication rules and the targets backing them survive the
-            // S3 delete (issue #1948); only the operator-authored rules go.
-            Some(remaining) => {
-                let data = serialize_config(&remaining)?;
-                update_bucket_config_for_incarnation(&bucket, BUCKET_REPLICATION_CONFIG, data, expected_incarnation_id)
-                    .await
-                    .map_err(ApiError::from)?;
-            }
-            None => {
-                delete_bucket_config_for_incarnation(&bucket, BUCKET_REPLICATION_CONFIG, expected_incarnation_id)
-                    .await
-                    .map_err(ApiError::from)?;
-            }
-        }
+        delete_bucket_config_for_incarnation(&bucket, BUCKET_REPLICATION_CONFIG, expected_incarnation_id)
+            .await
+            .map_err(ApiError::from)?;
         if let Some((targets, removed)) = updated_targets
             && let Err(err) =
                 write_replication_targets_after_config_delete(&bucket, &targets, removed, expected_incarnation_id).await
@@ -2542,14 +2485,6 @@ impl DefaultBucketUsecase {
 
         let targets_guard = lock_bucket_targets_metadata(&bucket).await;
         validate_bucket_replication_update(&bucket, &replication_configuration).await?;
-        let existing_config = match metadata_sys::get_replication_config(&bucket).await {
-            Ok((config, _)) => Some(config),
-            Err(StorageError::ConfigNotFound) => None,
-            Err(err) => return Err(ApiError::from(err).into()),
-        };
-        let site_peers = site_replication_remote_peer_deployment_ids().await?;
-        let replication_configuration =
-            merge_user_replication_config_update(replication_configuration, existing_config, &site_peers);
         let data = serialize_config(&replication_configuration)?;
         update_bucket_config_for_incarnation(&bucket, BUCKET_REPLICATION_CONFIG, data, expected_incarnation_id)
             .await
@@ -3179,185 +3114,6 @@ mod tests {
         assert!(arns.contains(destination));
     }
 
-    fn replication_rule_with_id(arn: &str, id: &str, priority: i32) -> ReplicationRule {
-        let mut rule = replication_rule_for_target(arn);
-        rule.id = Some(id.to_string());
-        rule.priority = Some(priority);
-        rule
-    }
-
-    fn site_peers(deployment_ids: &[&str]) -> HashSet<String> {
-        deployment_ids.iter().map(|id| id.to_string()).collect()
-    }
-
-    #[test]
-    fn put_replication_merge_preserves_site_replication_rules() {
-        let existing = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![
-                replication_rule_with_id("arn:rustfs:replication::peer-dep:bucket", "site-repl-peer-dep", 1),
-                replication_rule_with_id("arn:rustfs:replication:us-east-1:old:bucket", "old-user-rule", 2),
-            ],
-        };
-        let incoming = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![
-                replication_rule_with_id("arn:rustfs:replication:us-east-1:new:bucket", "new-user-rule", 1),
-                replication_rule_with_id("arn:rustfs:replication::forged-dep:bucket", "site-repl-peer-dep", 2),
-                replication_rule_with_id("arn:rustfs:replication::other-dep:bucket", "site-repl-other", 3),
-            ],
-        };
-
-        let merged = merge_user_replication_config_update(incoming, Some(existing), &site_peers(&["peer-dep"]));
-
-        let rules: Vec<_> = merged
-            .rules
-            .iter()
-            .map(|rule| (rule.id.as_deref().unwrap_or_default(), rule.destination.bucket.as_str()))
-            .collect();
-        assert_eq!(
-            rules,
-            vec![
-                ("new-user-rule", "arn:rustfs:replication:us-east-1:new:bucket"),
-                ("site-repl-other", "arn:rustfs:replication::other-dep:bucket"),
-                ("site-repl-peer-dep", "arn:rustfs:replication::peer-dep:bucket"),
-            ],
-            "user rules replaced, the reconciler rule for the current peer kept over the incoming impostor, \
-             a site-repl-* id that names no current peer is ordinary operator state"
-        );
-    }
-
-    // Rule ids do not reserve `site-repl-*`: outside site replication an
-    // owner's `site-repl-user` rule is ordinary state, so PUT stores it
-    // verbatim and DELETE removes it and garbage-collects its target.
-    #[test]
-    fn put_then_delete_replication_without_site_replication_treats_site_repl_id_as_user_rule() {
-        let user_arn = "arn:minio:replication:us-east-1:2f1c-remote:bucket";
-        let incoming = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![replication_rule_with_id(user_arn, "site-repl-user", 1)],
-        };
-
-        let stored = merge_user_replication_config_update(incoming.clone(), None, &HashSet::new());
-        assert_eq!(stored, incoming, "PUT on a non-site-replication bucket is verbatim");
-
-        let (remaining, removable) = split_replication_config_for_user_delete(stored, &HashSet::new());
-        assert!(remaining.is_none(), "DELETE must remove the operator's site-repl-* rule");
-        assert_eq!(removable, HashSet::from([user_arn.to_string()]));
-    }
-
-    // Under site replication only a rule the reconciler would derive — id
-    // `site-repl-<peer>` for a current peer, destination ARN naming the same
-    // peer — is reconciler-owned. Everything else is operator state.
-    #[test]
-    fn delete_replication_split_keeps_only_reconciler_derived_rules() {
-        let peer_arn = "arn:rustfs:replication::peer-dep:bucket";
-        let user_arn = "arn:minio:replication:us-east-1:2f1c-remote:bucket";
-        let config = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![
-                replication_rule_with_id(user_arn, "site-repl-user", 1),
-                replication_rule_with_id(user_arn, "site-repl-peer-dep", 2),
-                replication_rule_with_id("arn:rustfs:replication::gone-dep:bucket", "site-repl-gone-dep", 3),
-                replication_rule_with_id(peer_arn, "site-repl-peer-dep", 4),
-            ],
-        };
-
-        let (remaining, removable) = split_replication_config_for_user_delete(config, &site_peers(&["peer-dep"]));
-
-        let remaining = remaining.expect("the reconciler-derived rule must survive");
-        assert_eq!(remaining.rules.len(), 1);
-        assert_eq!(remaining.rules[0].destination.bucket, peer_arn);
-        assert_eq!(
-            removable,
-            HashSet::from([user_arn.to_string(), "arn:rustfs:replication::gone-dep:bucket".to_string()]),
-            "targets of operator rules and of a removed peer are garbage-collected"
-        );
-    }
-
-    #[test]
-    fn put_replication_merge_returns_incoming_verbatim_without_site_rules() {
-        let existing = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![replication_rule_with_id(
-                "arn:rustfs:replication:us-east-1:old:bucket",
-                "old-user-rule",
-                7,
-            )],
-        };
-        let incoming = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![replication_rule_with_id(
-                "arn:rustfs:replication:us-east-1:new:bucket",
-                "new-user-rule",
-                5,
-            )],
-        };
-
-        let merged = merge_user_replication_config_update(incoming.clone(), Some(existing), &HashSet::new());
-
-        assert_eq!(merged.role, incoming.role);
-        assert_eq!(merged.rules, incoming.rules, "non-SR buckets keep the verbatim overwrite semantics");
-    }
-
-    #[test]
-    fn delete_replication_split_keeps_site_rules_and_their_targets() {
-        let sr_arn = "arn:rustfs:replication::peer-dep:bucket";
-        let user_arn = "arn:rustfs:replication:us-east-1:user:bucket";
-        let config = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![
-                replication_rule_with_id(user_arn, "user-rule", 1),
-                replication_rule_with_id(sr_arn, "site-repl-peer-dep", 2),
-            ],
-        };
-
-        let (remaining, removable) = split_replication_config_for_user_delete(config, &site_peers(&["peer-dep"]));
-
-        let remaining = remaining.expect("site-replication rules must survive a user delete");
-        let ids: Vec<_> = remaining
-            .rules
-            .iter()
-            .map(|rule| rule.id.as_deref().unwrap_or_default())
-            .collect();
-        assert_eq!(ids, vec!["site-repl-peer-dep"]);
-        assert_eq!(removable, HashSet::from([user_arn.to_string()]));
-    }
-
-    #[test]
-    fn delete_replication_split_protects_targets_shared_with_site_rules() {
-        let sr_arn = "arn:rustfs:replication::peer-dep:bucket";
-        let config = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![
-                replication_rule_with_id(sr_arn, "user-rule-on-sr-target", 1),
-                replication_rule_with_id(sr_arn, "site-repl-peer-dep", 2),
-            ],
-        };
-
-        let (remaining, removable) = split_replication_config_for_user_delete(config, &site_peers(&["peer-dep"]));
-
-        assert!(remaining.is_some());
-        assert!(
-            removable.is_empty(),
-            "a target still referenced by a surviving site-replication rule must not be removed"
-        );
-    }
-
-    #[test]
-    fn delete_replication_split_removes_everything_without_site_rules() {
-        let user_arn = "arn:rustfs:replication:us-east-1:user:bucket";
-        let config = ReplicationConfiguration {
-            role: String::new(),
-            rules: vec![replication_rule_with_id(user_arn, "user-rule", 1)],
-        };
-
-        let (remaining, removable) = split_replication_config_for_user_delete(config, &site_peers(&["peer-dep"]));
-
-        assert!(remaining.is_none(), "without site-replication rules the whole config is deleted");
-        assert_eq!(removable, HashSet::from([user_arn.to_string()]));
-    }
-
     fn replication_targets_with_arn(arns: &[&str]) -> BucketTargets {
         BucketTargets {
             targets: arns

rustfs/src/app/object_usecase.rs

@@ -39,7 +39,7 @@ use super::storage_api::object_usecase::bucket::{
     metadata_sys,
     object_lock::{
         objectlock::{get_object_legalhold_meta, get_object_retention_meta},
-        objectlock_sys::{check_object_lock_for_deletion, is_retention_active},
+        objectlock_sys::{check_object_lock_for_deletion, is_retention_active, replication_write_may_pass_worm_gate},
     },
     predict_lifecycle_expiration,
     quota::{QuotaCheckResult, QuotaError, QuotaOperation},
@@ -3938,6 +3938,12 @@ pub(crate) fn validate_existing_object_lock_for_write(existing_obj_info: &Object
     if put_like_write_creates_new_version(opts) {
         return Ok(());
     }
+    // An authorized replication write may replace the locked version when the
+    // set layer's commit-lock LWW will judge every locking category; the set
+    // layer re-checks the same rule under the lock.
+    if replication_write_may_pass_worm_gate(&existing_obj_info.user_defined, opts) {
+        return Ok(());
+    }
 
     let legal_hold = get_object_legalhold_meta(&existing_obj_info.user_defined);
     if legal_hold
@@ -11037,6 +11043,47 @@ mod tests {
         assert_eq!(err.code(), &S3ErrorCode::AccessDenied);
     }
 
+    /// The source's lock state governs the replica (rustfs/backlog#1953):
+    /// an authorized replication write carrying the locking category's source
+    /// timestamp may overwrite a locked version; the set layer's LWW then
+    /// decides per category.
+    #[test]
+    fn validate_existing_object_lock_allows_authorized_replication_overwrite() {
+        let opts = ObjectOptions {
+            versioned: true,
+            version_id: Some(Uuid::new_v4().to_string()),
+            replication_request: true,
+            replication_retention_timestamp: Some(OffsetDateTime::UNIX_EPOCH),
+            replication_legalhold_timestamp: Some(OffsetDateTime::UNIX_EPOCH),
+            ..Default::default()
+        };
+
+        validate_existing_object_lock_for_write(&compliance_retained_object_info(), &opts)
+            .expect("replication write must bypass the destination COMPLIANCE lock");
+        validate_existing_object_lock_for_write(&legal_hold_object_info(), &opts)
+            .expect("replication write must bypass the destination legal hold");
+    }
+
+    /// Without the locking category's source timestamp the LWW merge cannot
+    /// judge it, so the write stays rejected instead of lifting the lock.
+    #[test]
+    fn validate_existing_object_lock_rejects_replication_overwrite_without_lock_timestamp() {
+        let opts = ObjectOptions {
+            versioned: true,
+            version_id: Some(Uuid::new_v4().to_string()),
+            replication_request: true,
+            replication_tagging_timestamp: Some(OffsetDateTime::UNIX_EPOCH),
+            ..Default::default()
+        };
+
+        let err = validate_existing_object_lock_for_write(&compliance_retained_object_info(), &opts)
+            .expect_err("COMPLIANCE lock must hold without a retention source timestamp");
+        assert_eq!(err.code(), &S3ErrorCode::AccessDenied);
+        let err = validate_existing_object_lock_for_write(&legal_hold_object_info(), &opts)
+            .expect_err("legal hold must hold without a legal-hold source timestamp");
+        assert_eq!(err.code(), &S3ErrorCode::AccessDenied);
+    }
+
     #[test]
     fn is_put_object_extract_requested_accepts_meta_header() {
         let mut headers = HeaderMap::new();

rustfs/src/app/storage_api.rs

@@ -587,6 +587,16 @@ pub(crate) mod bucket {
                     retain_until_date,
                 )
             }
+
+            pub(crate) fn replication_write_may_pass_worm_gate(
+                user_defined: &std::collections::HashMap<String, String>,
+                opts: &crate::storage::storage_api::StorageObjectOptions,
+            ) -> bool {
+                crate::storage::storage_api::ecstore_bucket::object_lock::objectlock_sys::replication_write_may_pass_worm_gate(
+                    user_defined,
+                    opts,
+                )
+            }
         }
     }
 
@@ -614,8 +624,6 @@ pub(crate) mod bucket {
 
         use crate::storage::storage_api::ecstore_bucket::replication as replication_contracts;
 
-        pub(crate) use replication_contracts::merge_user_replication_config;
-
         type ReplicationObjectBridge = crate::storage::storage_api::ecstore_bucket::replication::ReplicationObjectBridge;
         pub(crate) type DeleteReplicationConfigSnapshot =
             crate::storage::storage_api::ecstore_bucket::replication::DeleteReplicationConfigSnapshot;

rustfs/src/storage/ecfs.rs

@@ -63,54 +63,6 @@ use crate::app::storage_api::object_usecase::bucket::replication::{
 };
 use crate::storage::storage_api::ecfs_consumer::StorageObjectOptions as ObjectOptions;
 
-#[cfg(test)]
-static SITE_REPLICATION_GATE_TEST_OVERRIDE: std::sync::atomic::AtomicU8 = std::sync::atomic::AtomicU8::new(0);
-#[cfg(test)]
-const SITE_REPLICATION_GATE_FORCE_DISABLED: u8 = 1;
-#[cfg(test)]
-const SITE_REPLICATION_GATE_FORCE_ENABLED: u8 = 2;
-
-async fn site_replication_gate_enabled() -> S3Result<bool> {
-    #[cfg(test)]
-    match SITE_REPLICATION_GATE_TEST_OVERRIDE.load(std::sync::atomic::Ordering::SeqCst) {
-        SITE_REPLICATION_GATE_FORCE_DISABLED => return Ok(false),
-        SITE_REPLICATION_GATE_FORCE_ENABLED => return Ok(true),
-        _ => {}
-    }
-    crate::admin::handlers::site_replication::site_replication_enabled().await
-}
-
-/// MinIO `ErrReplicationDenyEditError`.
-fn replication_deny_edit_error() -> S3Error {
-    let mut err = S3Error::with_message(
-        S3ErrorCode::Custom("XMinioReplicationDenyEdit".into()),
-        "Sub-User is not allowed to edit Replication configuration",
-    );
-    err.set_status_code(StatusCode::BAD_REQUEST);
-    err
-}
-
-/// Site-replication gate for S3 replication-config edits (issue #1948).
-///
-/// On a site-replication deployment the bucket's replication config carries
-/// the operator-managed `site-repl-*` rules that keep every peer in sync, and
-/// a successful edit is broadcast to all peers — so a user holding only
-/// bucket-scoped `s3:PutReplicationConfiguration` could rewrite or erase
-/// replication net-wide. MinIO parity (`ErrReplicationDenyEditError`): only
-/// owner credentials (root or root-parented) may edit. Runs after the policy
-/// authorization in the access layer and only on the external S3 path — the
-/// reconciler and peer bucket-meta ingestion never route through these
-/// handlers.
-async fn deny_replication_config_edit_for_non_owner<T>(req: &S3Request<T>) -> S3Result<()> {
-    if crate::storage::access::req_info_ref(req)?.is_owner {
-        return Ok(());
-    }
-    if site_replication_gate_enabled().await? {
-        return Err(replication_deny_edit_error());
-    }
-    Ok(())
-}
-
 #[derive(Debug, Clone)]
 pub struct FS {
     /// This server's late-bound application-context slot (backlog#1052 S2).
@@ -548,7 +500,6 @@ impl S3 for FS {
         &self,
         req: S3Request<DeleteBucketReplicationInput>,
     ) -> S3Result<S3Response<DeleteBucketReplicationOutput>> {
-        deny_replication_config_edit_for_non_owner(&req).await?;
         let usecase = s3_api::bucket_usecase_for(self);
         usecase.execute_delete_bucket_replication(req).await
     }
@@ -1402,7 +1353,6 @@ impl S3 for FS {
         &self,
         req: S3Request<PutBucketReplicationInput>,
     ) -> S3Result<S3Response<PutBucketReplicationOutput>> {
-        deny_replication_config_edit_for_non_owner(&req).await?;
         let usecase = s3_api::bucket_usecase_for(self);
         usecase.execute_put_bucket_replication(req).await
     }
@@ -1969,103 +1919,3 @@ impl S3 for FS {
         Box::pin(usecase.execute_upload_part_copy(req)).await
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::{
-        FS, SITE_REPLICATION_GATE_FORCE_DISABLED, SITE_REPLICATION_GATE_FORCE_ENABLED, SITE_REPLICATION_GATE_TEST_OVERRIDE,
-    };
-    use crate::storage::access::ReqInfo;
-    use http::Method;
-    use http::StatusCode;
-    use s3s::dto::{DeleteBucketReplicationInput, PutBucketReplicationInput, ReplicationConfiguration};
-    use s3s::{S3, S3Error, S3ErrorCode, S3Request};
-    use std::sync::atomic::Ordering;
-
-    fn replication_config_edit_request<T>(input: T, is_owner: bool) -> S3Request<T> {
-        let mut req = S3Request {
-            input,
-            method: Method::PUT,
-            uri: http::Uri::from_static("/"),
-            headers: http::HeaderMap::new(),
-            extensions: http::Extensions::new(),
-            credentials: None,
-            region: None,
-            service: None,
-            trailing_headers: None,
-        };
-        req.extensions.insert(ReqInfo {
-            is_owner,
-            ..Default::default()
-        });
-        req
-    }
-
-    fn put_bucket_replication_input() -> PutBucketReplicationInput {
-        PutBucketReplicationInput {
-            bucket: "test-bucket".to_string(),
-            checksum_algorithm: None,
-            content_md5: None,
-            expected_bucket_owner: None,
-            replication_configuration: ReplicationConfiguration {
-                role: String::new(),
-                rules: Vec::new(),
-            },
-            token: None,
-        }
-    }
-
-    fn delete_bucket_replication_input() -> DeleteBucketReplicationInput {
-        DeleteBucketReplicationInput {
-            bucket: "test-bucket".to_string(),
-            expected_bucket_owner: None,
-        }
-    }
-
-    fn assert_replication_deny_edit(err: &S3Error) {
-        match err.code() {
-            S3ErrorCode::Custom(code) => assert_eq!(code, "XMinioReplicationDenyEdit"),
-            other => panic!("expected XMinioReplicationDenyEdit, got {other:?}"),
-        }
-        assert_eq!(err.status_code(), Some(StatusCode::BAD_REQUEST));
-    }
-
-    /// Single test on purpose: the branches share the process-wide gate
-    /// override, and parallel tests would race it.
-    #[tokio::test]
-    async fn replication_config_edit_gate_denies_only_non_owner_under_site_replication() {
-        let fs = FS::new();
-        SITE_REPLICATION_GATE_TEST_OVERRIDE.store(SITE_REPLICATION_GATE_FORCE_ENABLED, Ordering::SeqCst);
-
-        // Non-owner PUT/DELETE through the real S3 handlers: denied by the
-        // gate before the usecase (and thus the store) is ever touched.
-        let err = fs
-            .put_bucket_replication(replication_config_edit_request(put_bucket_replication_input(), false))
-            .await
-            .expect_err("non-owner PutBucketReplication must be denied while site replication is enabled");
-        assert_replication_deny_edit(&err);
-        let err = fs
-            .delete_bucket_replication(replication_config_edit_request(delete_bucket_replication_input(), false))
-            .await
-            .expect_err("non-owner DeleteBucketReplication must be denied while site replication is enabled");
-        assert_replication_deny_edit(&err);
-
-        // Owner passes the gate (the usecase's empty-rules structure error
-        // proves the request reached the usecase instead of the deny path).
-        let err = fs
-            .put_bucket_replication(replication_config_edit_request(put_bucket_replication_input(), true))
-            .await
-            .expect_err("owner request should pass the gate and fail later on config validation");
-        assert_eq!(err.code(), &S3ErrorCode::InvalidRequest);
-
-        // Without site replication the policy check alone still governs the edit.
-        SITE_REPLICATION_GATE_TEST_OVERRIDE.store(SITE_REPLICATION_GATE_FORCE_DISABLED, Ordering::SeqCst);
-        let err = fs
-            .put_bucket_replication(replication_config_edit_request(put_bucket_replication_input(), false))
-            .await
-            .expect_err("non-owner request should pass the gate and fail later on config validation");
-        assert_eq!(err.code(), &S3ErrorCode::InvalidRequest);
-
-        SITE_REPLICATION_GATE_TEST_OVERRIDE.store(0, Ordering::SeqCst);
-    }
-}

rustfs/src/storage/options.rs

@@ -554,10 +554,11 @@ fn apply_replication_timestamps_from_headers(headers: &HeaderMap<HeaderValue>, o
 
     // Persist into the internal metadata keys so a later outbound replication
     // pass (replication_target_boundary) reads the source's modification
-    // times instead of falling back to mod_time.
-    // TODO(P1-6): receiver-side LWW is still missing — when the stored
-    // per-category timestamp is newer than the inbound one, the existing
-    // tags/retention/legal-hold should win instead of being overwritten.
+    // times instead of falling back to mod_time. Receiver-side LWW happens at
+    // the set layer under the object write lock
+    // (ecstore set_disk::ops::object::merge_replication_metadata_lww,
+    // rustfs/backlog#1953): a category whose stored timestamp is newer than
+    // the inbound one keeps the local values.
     for (timestamp, suffix) in [
         (opts.replication_tagging_timestamp, SUFFIX_TAGGING_TIMESTAMP),
         (opts.replication_retention_timestamp, SUFFIX_OBJECTLOCK_RETENTION_TIMESTAMP),