test(e2e): pin bounded physical reads for compressed multipart range GETs

Byte-exactness tests stay green if the compressed range seek regresses into
decoding from byte zero: the returned bytes are still correct and only the
read amplification explodes. Assert the cost side as well.

The observation reuses rustfs_io_get_object_shard_read_observed_bytes_total,
already emitted per shard read by the erasure layer, so no production code is
instrumented. The OTLP collector learns to accumulate a second counter, keyed
by its path/role/outcome labels rather than by data-point position, which is
not stable across exports.

Two failure modes the assertions guard against:

- With RUSTFS_OBS_METER_INTERVAL=1, treating one unchanged sample as settled
  measures a delta of zero, because the range read's counter has not been
  exported yet. Settling now requires several consecutive equal samples.
- An upper bound alone passes vacuously on a zero delta, so a lower bound
  turns "measured nothing" into a failure instead of a green run.

Refs rustfs/rustfs#5957, backlog#1848.

crates/checksums/src/base64.rs

@@ -11,7 +11,6 @@
 // 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.
-#![allow(dead_code)]
 
 use base64_simd::STANDARD;
 

crates/checksums/src/http.rs

@@ -38,7 +38,10 @@ pub const XXHASH_3_HEADER_NAME: &str = "x-amz-checksum-xxhash3";
 pub const XXHASH_64_HEADER_NAME: &str = "x-amz-checksum-xxhash64";
 pub const XXHASH_128_HEADER_NAME: &str = "x-amz-checksum-xxhash128";
 
-#[allow(dead_code)]
+#[allow(
+    dead_code,
+    reason = "Content-MD5 wire name, resolved by header_name() below and asserted by this crate's tests (backlog#1823)"
+)]
 pub(crate) static MD5_HEADER_NAME: &str = "content-md5";
 
 pub const CHECKSUM_ALGORITHMS_IN_PRIORITY_ORDER: [&str; 5] =

crates/checksums/src/lib.rs

@@ -476,13 +476,19 @@ impl Checksum for Xxhash64 {
     }
 }
 
-#[allow(dead_code)]
 #[derive(Debug, Default)]
+#[allow(
+    dead_code,
+    reason = "Content-MD5 is not a ChecksumAlgorithm variant and has no arm in into_impl: S3 carries it as its own header, separate from the x-amz-checksum-* family. This impl exists so the two paths share the Checksum trait, and is asserted by this crate's tests (backlog#1823)"
+)]
 struct Md5 {
     hasher: md5::Md5,
 }
 
-#[allow(dead_code)]
+#[allow(
+    dead_code,
+    reason = "Content-MD5 is not a ChecksumAlgorithm variant and has no arm in into_impl: S3 carries it as its own header, separate from the x-amz-checksum-* family. This impl exists so the two paths share the Checksum trait, and is asserted by this crate's tests (backlog#1823)"
+)]
 impl Md5 {
     fn update(&mut self, bytes: &[u8]) {
         use md5::Digest;

crates/e2e_test/src/inline_fast_path_cluster_test.rs

@@ -67,6 +67,9 @@ type MetricValues = Arc<Mutex<BTreeMap<String, MetricPointVersions>>>;
 
 const KIB: usize = 1024;
 const READER_PATH_COUNTER: &str = "rustfs_io_get_object_reader_path_by_size_total";
+/// Physical bytes the erasure layer pulled from disk, emitted per shard read by
+/// `crates/ecstore/src/erasure/coding/decode.rs`.
+const SHARD_READ_BYTES_COUNTER: &str = "rustfs_io_get_object_shard_read_observed_bytes_total";
 const MSGPACK_JSON_DECODE_COUNTER: &str = "rustfs_system_network_internode_msgpack_json_decode_total";
 const MSGPACK_JSON_FALLBACK_COUNTER: &str = "rustfs_system_network_internode_msgpack_json_fallback_total";
 const MSGPACK_JSON_DECODE_ERROR_COUNTER: &str = "rustfs_system_network_internode_msgpack_json_decode_error_total";
@@ -146,6 +149,7 @@ struct OtlpMetricCollector {
     decode_values: MetricValues,
     fallback_values: MetricValues,
     decode_error_values: MetricValues,
+    shard_read_values: MetricValues,
     task: JoinHandle<()>,
 }
 
@@ -157,10 +161,12 @@ impl OtlpMetricCollector {
         let decode_values = Arc::new(Mutex::new(BTreeMap::new()));
         let fallback_values = Arc::new(Mutex::new(BTreeMap::new()));
         let decode_error_values = Arc::new(Mutex::new(BTreeMap::new()));
+        let shard_read_values = Arc::new(Mutex::new(BTreeMap::new()));
         let task_values = values.clone();
         let task_decode_values = decode_values.clone();
         let task_fallback_values = fallback_values.clone();
         let task_decode_error_values = decode_error_values.clone();
+        let task_shard_read_values = shard_read_values.clone();
         let task = tokio::spawn(async move {
             loop {
                 let Ok((stream, _)) = listener.accept().await else {
@@ -170,6 +176,7 @@ impl OtlpMetricCollector {
                 let decode_values = task_decode_values.clone();
                 let fallback_values = task_fallback_values.clone();
                 let decode_error_values = task_decode_error_values.clone();
+                let shard_read_values = task_shard_read_values.clone();
                 tokio::spawn(async move {
                     let _ = hyper::server::conn::http1::Builder::new()
                         .serve_connection(
@@ -181,6 +188,7 @@ impl OtlpMetricCollector {
                                     decode_values.clone(),
                                     fallback_values.clone(),
                                     decode_error_values.clone(),
+                                    shard_read_values.clone(),
                                 )
                             }),
                         )
@@ -194,10 +202,48 @@ impl OtlpMetricCollector {
             decode_values,
             fallback_values,
             decode_error_values,
+            shard_read_values,
             task,
         })
     }
 
+    /// Total physical bytes read from disk across every shard-read label set.
+    async fn shard_read_bytes_total(&self) -> u64 {
+        self.shard_read_values
+            .lock()
+            .await
+            .values()
+            .map(|versions| versions.values().map(|(_, value)| *value).sum::<u64>())
+            .sum()
+    }
+
+    /// Waits until the shard-read counter stops advancing so a measurement window
+    /// is not polluted by exports still in flight.
+    ///
+    /// Requires several consecutive equal samples spanning more than one export
+    /// interval (`RUSTFS_OBS_METER_INTERVAL=1`): a single unchanged sample only
+    /// proves the latest export has not landed yet, which silently reads as "no
+    /// disk reads happened" and makes any upper-bound assertion vacuous.
+    async fn wait_for_shard_read_bytes_to_settle(&self) -> TestResult<u64> {
+        const REQUIRED_STABLE_SAMPLES: usize = 5;
+        let mut last = self.shard_read_bytes_total().await;
+        let mut stable = 0;
+        for _ in 0..60 {
+            sleep(Duration::from_millis(500)).await;
+            let current = self.shard_read_bytes_total().await;
+            if current == last {
+                stable += 1;
+                if stable >= REQUIRED_STABLE_SAMPLES {
+                    return Ok(current);
+                }
+            } else {
+                stable = 0;
+                last = current;
+            }
+        }
+        Err("timed out waiting for shard-read byte counter to settle".into())
+    }
+
     async fn reader_path_total(&self, path: &str, object_class: &str, size_bucket: &str) -> u64 {
         self.reader_path_values(path, object_class, size_bucket).await.values().sum()
     }
@@ -321,6 +367,7 @@ async fn handle_metric_export(
     decode_values: MetricValues,
     fallback_values: MetricValues,
     decode_error_values: MetricValues,
+    shard_read_values: MetricValues,
 ) -> Result<Response<Full<Bytes>>, Infallible> {
     if request.uri().path() != "/v1/metrics" {
         return Ok(response(StatusCode::NOT_FOUND));
@@ -354,7 +401,9 @@ async fn handle_metric_export(
             let mut decode_values = decode_values.lock().await;
             let mut fallback_values = fallback_values.lock().await;
             let mut decode_error_values = decode_error_values.lock().await;
+            let mut shard_read_values = shard_read_values.lock().await;
             record_reader_path_metrics(&export, &mut values);
+            record_shard_read_bytes_metrics(&export, &mut shard_read_values);
             record_msgpack_decode_metrics(&export, &mut decode_values);
             record_msgpack_fallback_metrics(&export, &mut fallback_values);
             record_msgpack_decode_error_metrics(&export, &mut decode_error_values);
@@ -375,6 +424,50 @@ fn reader_path_metric_key(path: &str, object_class: &str, size_bucket: &str) ->
     format!("{path}\u{1f}{object_class}\u{1f}{size_bucket}")
 }
 
+/// Accumulates `SHARD_READ_BYTES_COUNTER` across all label sets. Only the total
+/// matters: it is the number of physical bytes the erasure layer actually pulled
+/// from disk, which is what separates a bounded per-part read from a decode of
+/// the whole object.
+fn record_shard_read_bytes_metrics(export: &ExportMetricsServiceRequest, values: &mut BTreeMap<String, MetricPointVersions>) {
+    for resource_metrics in &export.resource_metrics {
+        for scope_metrics in &resource_metrics.scope_metrics {
+            for metric in &scope_metrics.metrics {
+                if metric.name != SHARD_READ_BYTES_COUNTER {
+                    continue;
+                }
+                let Some(metric::Data::Sum(sum)) = &metric.data else {
+                    continue;
+                };
+                for point in &sum.data_points {
+                    let Some(number_data_point::Value::AsInt(value)) = point.value.as_ref() else {
+                        continue;
+                    };
+                    let value = u64::try_from(*value).unwrap_or_default();
+                    // Keyed by labels, not by position: point order within an export
+                    // is not guaranteed stable, so an index key would alias distinct
+                    // series across batches.
+                    let key = format!(
+                        "{}\u{1f}{}\u{1f}{}",
+                        attribute_string(&point.attributes, "path").unwrap_or_default(),
+                        attribute_string(&point.attributes, "role").unwrap_or_default(),
+                        attribute_string(&point.attributes, "outcome").unwrap_or_default(),
+                    );
+                    values
+                        .entry(key)
+                        .or_default()
+                        .entry(point.start_time_unix_nano)
+                        .and_modify(|current| {
+                            if point.time_unix_nano >= current.0 {
+                                *current = (point.time_unix_nano, value);
+                            }
+                        })
+                        .or_insert((point.time_unix_nano, value));
+                }
+            }
+        }
+    }
+}
+
 fn record_reader_path_metrics(export: &ExportMetricsServiceRequest, values: &mut BTreeMap<String, MetricPointVersions>) {
     for resource_metrics in &export.resource_metrics {
         for scope_metrics in &resource_metrics.scope_metrics {
@@ -1864,6 +1957,86 @@ async fn four_node_multipart_disk_compression_roundtrip() -> TestResult {
     Ok(())
 }
 
+/// A tail range over a compressed multipart object must read only the physical
+/// data it needs, not decode the object from byte zero.
+///
+/// The byte-exactness tests around this one stay green even if the seek path
+/// regresses into decoding from the start of the object: the bytes returned are
+/// still correct, only the read amplification explodes. This asserts the cost
+/// side, using `SHARD_READ_BYTES_COUNTER` — already emitted per shard read by the
+/// erasure layer, so no production code is instrumented for the test.
+///
+/// `get_compressed_offsets` skips whole preceding parts by their stored size and
+/// then seeks inside the covering part via its compression index, so a bounded
+/// read costs on the order of the covering part's block size against a ~5 MiB
+/// object.
+#[tokio::test]
+#[serial]
+async fn four_node_compressed_multipart_tail_range_reads_are_bounded() -> TestResult {
+    init_logging();
+
+    let collector = OtlpMetricCollector::start().await?;
+    let mut cluster = RustFSTestClusterEnvironment::new(4).await?;
+    configure_reader_metric_cluster(&mut cluster, &collector);
+    cluster.set_env("RUSTFS_COMPRESSION_ENABLED", "true");
+    cluster.set_env("RUSTFS_COMPRESSION_MULTIPART_ENABLED", "true");
+    cluster.start().await?;
+
+    let bucket = "inline-multipart-compression-tail-range";
+    cluster.create_test_bucket(bucket).await?;
+    let client = cluster.create_s3_client(0)?;
+    let key = "multipart/tail-range.txt";
+    let (body, _second_part, etag) = put_two_part_multipart(&client, bucket, key).await?;
+
+    // Establish that the object really took the compressed read path; otherwise a
+    // small delta below would only prove compression never happened.
+    assert_reader_path(
+        &collector,
+        &client,
+        ReaderPathExpectation::for_class(ReaderObject::new(bucket, key, &body, etag.as_deref(), None), LEGACY_DUPLEX, COMPRESSED),
+    )
+    .await?;
+
+    let baseline = collector.wait_for_shard_read_bytes_to_settle().await?;
+
+    let tail_len = 4 * KIB;
+    let start = body.len() - tail_len;
+    let end = body.len() - 1;
+    let range = client
+        .get_object()
+        .bucket(bucket)
+        .key(key)
+        .range(format!("bytes={start}-{end}"))
+        .send()
+        .await?;
+    let tail = range.body.collect().await?.into_bytes();
+    assert_eq!(tail.as_ref(), &body[start..], "tail range returned wrong bytes");
+
+    let after = collector.wait_for_shard_read_bytes_to_settle().await?;
+    let read_bytes = after.saturating_sub(baseline);
+
+    // A zero delta means the window caught nothing — an unexported counter, or a
+    // read served without touching the erasure layer — which would make the upper
+    // bound vacuously true. Fail instead of passing blind.
+    assert!(
+        read_bytes > 0,
+        "no shard reads observed for the tail range; the budget assertion below would be vacuous"
+    );
+
+    // Part 1 alone is MPU_PART_1_SIZE, so a whole-object decode cannot come in
+    // under it. Half the logical size leaves generous headroom for erasure padding
+    // and unrelated background reads while still failing loudly on a full decode.
+    let budget = (body.len() / 2) as u64;
+    assert!(
+        read_bytes < budget,
+        "tail range read {read_bytes} physical bytes for a {tail_len}-byte range (budget {budget}, object {} bytes): \
+         the read is not bounded to the covering part",
+        body.len()
+    );
+
+    Ok(())
+}
+
 #[tokio::test]
 #[serial]
 async fn four_node_mixed_msgpack_compat_mode_preserves_fallback_controls() -> TestResult {

crates/ecstore/src/bucket/bucket_target_sys.rs

@@ -82,7 +82,6 @@ use tracing::warn;
 use url::Url;
 use uuid::Uuid;
 
-const DEFAULT_HEALTH_CHECK_RELOAD_DURATION: Duration = Duration::from_secs(30 * 60);
 const MAX_CONCURRENT_TARGET_HEALTH_CHECKS: usize = 16;
 const REDACTED_CREDENTIAL: &str = "<redacted>";
 

crates/ecstore/src/bucket/lifecycle/bucket_lifecycle_ops.rs

@@ -126,11 +126,23 @@ const EVENT_LIFECYCLE_EXPIRED_DETECTED: &str = "lifecycle_expired_detected";
 const EVENT_LIFECYCLE_NOT_ENQUEUED: &str = "lifecycle_not_enqueued";
 const EVENT_LIFECYCLE_DELETE_DISPATCHED: &str = "lifecycle_delete_dispatched";
 const EVENT_LIFECYCLE_DELETE_COMPLETED: &str = "lifecycle_delete_completed";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 const EVENT_LIFECYCLE_TIER_AUDIT: &str = "lifecycle_tier_audit";
 const EVENT_LIFECYCLE_TIER_OPERATION_FAILED: &str = "lifecycle_tier_operation_failed";
 const EVENT_LIFECYCLE_DELETE_FAILED: &str = "lifecycle_delete_failed";
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub type TimeFn = Arc<dyn Fn() -> Pin<Box<dyn Future<Output = ()> + Send>> + Send + Sync + 'static>;
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub type TraceFn =
     Arc<dyn Fn(String, HashMap<String, String>) -> Pin<Box<dyn Future<Output = ()> + Send>> + Send + Sync + 'static>;
 pub type ExpiryOpType = Box<dyn ExpiryOp + Send + Sync + 'static>;
@@ -140,9 +152,21 @@ static TIER_FREE_VERSION_RECOVERY_STARTED: OnceLock<()> = OnceLock::new();
 static MANUAL_TRANSITION_JOB_RECOVERY_STARTED: OnceLock<()> = OnceLock::new();
 
 pub const AMZ_OBJECT_TAGGING: &str = "X-Amz-Tagging";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub const AMZ_TAG_COUNT: &str = "x-amz-tagging-count";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub const AMZ_TAG_DIRECTIVE: &str = "X-Amz-Tagging-Directive";
 pub const AMZ_ENCRYPTION_AES: &str = "AES256";
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub const AMZ_ENCRYPTION_KMS: &str = "aws:kms";
 
 pub const ERR_INVALID_STORAGECLASS: &str = "invalid tier.";
@@ -280,6 +304,10 @@ impl LifecycleSys {
         }
     }
 
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
     pub fn trace(oi: &ObjectInfo) -> TraceFn {
         let bucket = oi.bucket.clone();
         let name = oi.name.clone();
@@ -570,6 +598,10 @@ async fn delete_free_version_remote_object(
     Ok(())
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn delete_free_version_remote_object_then<T, F, Fut>(
     oi: &ObjectInfo,
     tier_config_mgr: &Arc<RwLock<TierConfigMgr>>,
@@ -2868,6 +2900,10 @@ fn stale_upload_default_due(initiated: OffsetDateTime, default_expiry: StdDurati
     initiated + time::Duration::seconds(default_expiry.as_secs() as i64)
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn stale_upload_current_size(set: &Arc<SetDisks>, metadata: &HashMap<String, String>, upload_dir: &str) -> Option<usize> {
     stale_upload_current_size_with_opts(set, metadata, upload_dir, false).await
 }
@@ -3352,6 +3388,10 @@ pub async fn validate_transition_tier(lc: &BucketLifecycleConfiguration) -> Resu
     Ok(())
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 fn mark_delete_opts_skip_decommissioned_on_remote_success(opts: &mut ObjectOptions, remote_delete_succeeded: bool) {
     if remote_delete_succeeded {
         opts.skip_decommissioned = true;
@@ -4339,6 +4379,10 @@ pub async fn expire_transitioned_object(
     Ok(dobj)
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub fn gen_transition_objname(bucket: &str) -> Result<String, Error> {
     let us = Uuid::new_v4().to_string();
     let mut hasher = Sha256::new();
@@ -4373,6 +4417,10 @@ pub async fn transition_object(api: Arc<ECStore>, oi: &ObjectInfo, lae: LcAuditE
     result
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub fn audit_tier_actions(_tier: &str, bytes: i64) -> TimeFn {
     let tier = _tier.to_string();
     Arc::new(move || {
@@ -4391,6 +4439,10 @@ pub fn audit_tier_actions(_tier: &str, bytes: i64) -> TimeFn {
     })
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn get_transitioned_object_reader(
     bucket: &str,
     object: &str,
@@ -5145,6 +5197,10 @@ async fn lifecycle_delete_config_snapshot(api: &ECStore, oi: &ObjectInfo) -> Res
     ReplicationObjectBridge::delete_request_config(api, &oi.bucket).await
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn apply_lifecycle_action(event: &lifecycle::Event, src: &LcEventSrc, oi: &ObjectInfo) -> bool {
     let mut success = false;
     match event.action {
@@ -7422,6 +7478,10 @@ mod tests {
     // process environment while `env::set_var`/`env::remove_var` is active.
     // SAFETY: keep this note adjacent to the allowance for the repository guard.
     #[allow(unsafe_code)]
+    #[allow(
+        dead_code,
+        reason = "transition-queue env fixture kept for tests that scope those vars; no test uses it today (backlog#1823)"
+    )]
     async fn with_transition_queue_env_async<F, Fut>(capacity: Option<&str>, timeout_ms: Option<&str>, test_fn: F)
     where
         F: FnOnce() -> Fut,

crates/ecstore/src/bucket/lifecycle/manual_transition_job.rs

@@ -759,6 +759,10 @@ pub struct ManualTransitionWorkerResultRecord {
 }
 
 impl ManualTransitionWorkerResultRecord {
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
     pub fn new(job_id: Uuid, task_key: impl Into<String>, result: ManualTransitionWorkerResult) -> Self {
         Self::new_with_reason(job_id, task_key, result, None)
     }
@@ -1257,6 +1261,10 @@ pub(crate) async fn save_manual_transition_task_if_absent(
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn load_manual_transition_task_record(
     api: Arc<ECStore>,
     job_id: Uuid,
@@ -1320,6 +1328,10 @@ async fn scan_manual_transition_task_journal(api: Arc<ECStore>, job_id: Uuid) ->
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn load_manual_transition_worker_result_stats(
     api: Arc<ECStore>,
     job_id: Uuid,
@@ -1455,6 +1467,10 @@ async fn scan_manual_transition_worker_result_journal(
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn reconcile_manual_transition_worker_results(
     api: Arc<ECStore>,
     job_id: Uuid,

crates/ecstore/src/bucket/lifecycle/replication_sink.rs

@@ -15,25 +15,35 @@
 use rustfs_common::metrics::IlmAction;
 
 use crate::bucket::lifecycle::lifecycle::ObjectOpts;
+use crate::bucket::replication::ReplicationLifecycleBridge;
 pub(crate) use crate::bucket::replication::ReplicationStatusType;
 #[cfg(test)]
 pub(crate) use crate::bucket::replication::VersionPurgeStatusType;
 pub(crate) use crate::bucket::replication::{
     DeleteReplicationConfigSnapshot, ReplicationObjectBridge, replication_state_to_filemeta,
 };
-use crate::bucket::replication::{ReplicationLifecycleBridge, ReplicationLifecycleConfig};
 use crate::storage_api_contracts::object::DeletedObject;
 
-pub(crate) type LifecycleReplicationConfig = ReplicationLifecycleConfig;
-
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn has_pending_version_purge(obj: &ObjectOpts) -> bool {
     obj.version_purge_status.is_pending()
 }
 
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn has_pending_object_replication(obj: &ObjectOpts) -> bool {
     replication_status_blocks_lifecycle(&obj.replication_status)
 }
 
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn has_pending_lifecycle_replication(obj: &ObjectOpts) -> bool {
     has_pending_object_replication(obj) || has_pending_version_purge(obj)
 }

crates/ecstore/src/bucket/lifecycle/tagging_boundary.rs

@@ -14,6 +14,10 @@
 
 use std::collections::HashMap;
 
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) fn decode_tags_to_map(tags: &str) -> HashMap<String, String> {
     crate::bucket::tagging::decode_tags_to_map(tags)
 }

crates/ecstore/src/bucket/lifecycle/tier_delete_journal.rs

@@ -331,6 +331,10 @@ where
     persist_tier_delete_journal_entry(api, &committed).await
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn abort_tier_delete_journal_entry<S>(api: Arc<S>, je: &Jentry) -> std::io::Result<()>
 where
     S: ObjectOperations<

crates/ecstore/src/bucket/lifecycle/tier_free_version_recovery.rs

@@ -148,6 +148,10 @@ struct RecoveryCursor {
     object: String,
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn recover_tier_free_versions(
     api: Arc<ECStore>,
     limit: usize,

crates/ecstore/src/bucket/lifecycle/tier_sweeper.rs

@@ -385,6 +385,10 @@ impl ExpiryOp for Jentry {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn delete_object_from_remote_tier(obj_name: &str, rv_id: &str, tier_name: &str) -> Result<(), std::io::Error> {
     let result = delete_object_from_remote_tier_raw(obj_name, rv_id, tier_name).await;
     if let Err(err) = &result
@@ -395,6 +399,10 @@ pub async fn delete_object_from_remote_tier(obj_name: &str, rv_id: &str, tier_na
     result
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn delete_object_from_remote_tier_raw(obj_name: &str, rv_id: &str, tier_name: &str) -> Result<(), std::io::Error> {
     #[cfg(test)]
     if let Some(result) = run_remote_tier_delete_test_hook(obj_name, rv_id, tier_name) {
@@ -405,6 +413,10 @@ async fn delete_object_from_remote_tier_raw(obj_name: &str, rv_id: &str, tier_na
     delete_object_from_remote_tier_raw_with_manager(obj_name, rv_id, tier_name, &tier_config_mgr).await
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 async fn delete_object_from_remote_tier_raw_with_manager(
     obj_name: &str,
     rv_id: &str,
@@ -485,6 +497,10 @@ pub enum RemoteTierDeleteOutcome {
     AlreadyRemoved,
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+)]
 pub async fn delete_object_from_remote_tier_idempotent(
     obj_name: &str,
     rv_id: &str,

crates/ecstore/src/bucket/lifecycle/transition_transaction.rs

@@ -50,8 +50,16 @@ pub type Result<T> = std::result::Result<T, TransitionTransactionError>;
 #[derive(Debug, thiserror::Error)]
 pub enum TransitionTransactionError {
     #[error("transition transaction already exists")]
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
     AlreadyExists,
     #[error("transition transaction is not found")]
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity tier/lifecycle entry point that this port never wired (backlog#1823)"
+    )]
     NotFound,
     #[error("transition transaction is corrupt: {0}")]
     Corrupt(&'static str),

crates/ecstore/src/bucket/metadata_sys.rs

@@ -60,12 +60,14 @@ struct ConfigWriteLockProbeState {
 static CONFIG_WRITE_LOCK_PROBES: std::sync::OnceLock<StdMutex<Vec<Arc<ConfigWriteLockProbeState>>>> = std::sync::OnceLock::new();
 
 #[cfg(any(test, feature = "test-util"))]
+#[allow(dead_code, reason = "installed by tests behind `--features test-util` (backlog#1823)")]
 pub struct ConfigWriteLockProbe {
     state: Arc<ConfigWriteLockProbeState>,
 }
 
 #[cfg(any(test, feature = "test-util"))]
 impl ConfigWriteLockProbe {
+    #[allow(dead_code, reason = "installed by tests behind `--features test-util` (backlog#1823)")]
     pub fn install(bucket: &str) -> Self {
         let state = Arc::new(ConfigWriteLockProbeState {
             bucket: bucket.to_string(),
@@ -84,6 +86,7 @@ impl ConfigWriteLockProbe {
         Self { state }
     }
 
+    #[allow(dead_code, reason = "installed by tests behind `--features test-util` (backlog#1823)")]
     pub async fn wait_until_attempted(&self) {
         tokio::time::timeout(Duration::from_secs(30), self.state.arrived.notified())
             .await
@@ -890,6 +893,10 @@ pub async fn get_bucket_policy_raw(bucket: &str) -> Result<(String, OffsetDateTi
     bucket_meta_sys.get_bucket_policy_raw(bucket).await
 }
 
+#[allow(
+    dead_code,
+    reason = "free-function facade over the live BucketMetadataSys::get_bucket_acl_config; no caller in this port (backlog#1823)"
+)]
 pub async fn get_bucket_acl_config(bucket: &str) -> Result<(String, OffsetDateTime)> {
     let bucket_meta_sys_lock = get_bucket_metadata_sys()?;
     let bucket_meta_sys = bucket_meta_sys_lock.read().await;
@@ -1104,6 +1111,10 @@ pub async fn get_config_from_disk(bucket: &str) -> Result<BucketMetadata> {
     bucket_meta_sys.get_config_from_disk(bucket).await
 }
 
+#[allow(
+    dead_code,
+    reason = "ambient-facade variant of the live created_at_in; no caller in this port (backlog#1823)"
+)]
 pub async fn created_at(bucket: &str) -> Result<OffsetDateTime> {
     let bucket_meta_sys_lock = get_bucket_metadata_sys()?;
     let bucket_meta_sys = bucket_meta_sys_lock.read().await;
@@ -1617,6 +1628,7 @@ impl BucketMetadataSys {
     /// [`Self::update`], with the payload computed from the loaded metadata
     /// instead of supplied up front. Loads through this system's own store so
     /// the read and the persisted write target the same instance.
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     async fn update_config_with<F>(&self, bucket: &str, config_file: &str, mutate: F) -> Result<OffsetDateTime>
     where
         F: FnOnce(&BucketMetadata) -> Result<Vec<u8>> + Send,
@@ -1721,6 +1733,7 @@ impl BucketMetadataSys {
     /// A miss is never published as an authoritative default, and a snapshot
     /// read before delete plus same-name recreation cannot replace the new
     /// generation.
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub(crate) async fn reload_from_store(&self, bucket: &str) -> Result<()> {
         if is_meta_bucketname(bucket) {
             return Err(Error::other("errInvalidArgument"));

crates/ecstore/src/bucket/mod.rs

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 // #730: bucket subsystems still contain staged ECStore migration code.
-#![allow(dead_code)]
 
 pub mod bandwidth;
 pub mod bucket_target_sys;

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

@@ -136,6 +136,7 @@ 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)
@@ -151,6 +152,7 @@ fn has_legal_hold(user_defined: &std::collections::HashMap<String, String>) -> b
 /// # Returns
 /// * `true` if the object is locked (cannot be deleted/modified)
 /// * `false` if the object is not locked
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn is_object_locked_by_metadata(user_defined: &std::collections::HashMap<String, String>, is_delete_marker: bool) -> bool {
     // Delete markers are never locked
     if is_delete_marker {

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

@@ -193,6 +193,7 @@ pub enum QuotaError {
 }
 
 #[derive(Debug, Serialize)]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub struct QuotaErrorResponse {
     #[serde(rename = "Code")]
     pub code: String,
@@ -208,6 +209,7 @@ pub struct QuotaErrorResponse {
 }
 
 impl QuotaErrorResponse {
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub fn new(quota_error: &QuotaError, request_id: &str, host_id: &str) -> Self {
         match quota_error {
             QuotaError::QuotaExceeded { .. } => Self {

crates/ecstore/src/bucket/quota/reservation.rs

@@ -899,6 +899,7 @@ async fn save_ledger_locked(
 }
 
 #[cfg(any(test, feature = "test-util"))]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn fail_next_quota_ledger_save_for_test() {
     FAIL_NEXT_LEDGER_SAVE.store(true, std::sync::atomic::Ordering::SeqCst);
 }

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

@@ -60,7 +60,7 @@ pub use replication_filemeta_boundary::{
 pub(crate) use replication_filemeta_boundary::{
     replication_state_from_filemeta, replication_status_from_filemeta, version_purge_status_from_filemeta,
 };
-pub(crate) use replication_lifecycle_bridge::{ReplicationLifecycleBridge, ReplicationLifecycleConfig};
+pub(crate) use replication_lifecycle_bridge::ReplicationLifecycleBridge;
 pub(crate) use replication_migration_bridge::ReplicationMigrationBridge;
 pub use replication_object_bridge::ReplicationObjectBridge;
 pub use replication_object_config::{DeleteReplicationConfigSnapshot, ReplicationConfig};

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

@@ -37,6 +37,10 @@ impl ReplicationConfigStore {
         com::read_config_limited(api, file, max_bytes).await
     }
 
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     pub(crate) async fn read_no_lock<S>(api: Arc<S>, file: &str) -> Result<Vec<u8>>
     where
         S: ReplicationObjectIO,

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

@@ -24,15 +24,27 @@ use super::replication_storage_boundary::{
     DeletedObject, ObjectInfo, ObjectOptions, ObjectToDelete, deleted_object_for_replication,
 };
 
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) type ReplicationLifecycleConfig = ReplicationConfig;
 
 pub(crate) struct ReplicationLifecycleBridge;
 
 impl ReplicationLifecycleBridge {
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn new_config(config: ReplicationConfiguration) -> ReplicationLifecycleConfig {
         ReplicationConfig::new(Some(config), None)
     }
 
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn has_pending_version_purge(
         config: &ReplicationLifecycleConfig,
         object_name: &str,
@@ -45,6 +57,10 @@ impl ReplicationLifecycleBridge {
                 .is_some_and(|config| config.has_active_rules(object_name, true))
     }
 
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) async fn check_delete_replication(
         bucket: &str,
         object: &ObjectToDelete,
@@ -54,6 +70,10 @@ impl ReplicationLifecycleBridge {
         check_replicate_delete(bucket, object, source, opts, None).await
     }
 
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn version_delete_replication_state(decision: &ReplicateDecision) -> ReplicationState {
         let pending_status = decision.pending_status();
         ReplicationState {

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

@@ -19,17 +19,33 @@ use time::OffsetDateTime;
 use super::replication_error_boundary::Result;
 use crate::bucket::msgp_decode;
 
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) struct ReplicationMsgpCodec;
 
 impl ReplicationMsgpCodec {
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn read_ext8_time<R: Read>(rd: &mut R) -> Result<OffsetDateTime> {
         msgp_decode::read_msgp_ext8_time(rd)
     }
 
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn skip_value<R: Read>(rd: &mut R) -> Result<()> {
         msgp_decode::skip_msgp_value(rd)
     }
 
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn write_time<W: Write>(wr: &mut W, time: OffsetDateTime) -> Result<()> {
         msgp_decode::write_msgp_time(wr, time)
     }

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

@@ -77,6 +77,10 @@ impl ReplicationObjectBridge {
         load_delete_request_config_in(ctx, bucket).await
     }
 
+    #[allow(
+        dead_code,
+        reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+    )]
     pub(crate) async fn delete_config_snapshot_in(
         ctx: &ReplicationInstanceContext,
         bucket: &str,

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

@@ -231,6 +231,10 @@ pub(crate) async fn load_delete_replication_config(
     delete_snapshot_from_metadata(ReplicationMetadataStore::delete_metadata(bucket).await?)
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+)]
 pub(crate) async fn load_delete_replication_config_in(
     ctx: &ReplicationInstanceContext,
     bucket: &str,

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

@@ -217,6 +217,10 @@ impl DurableMrfBacklogTracker {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+)]
 fn durable_mrf_backlog_tracker_from_entries(entries: &[MrfReplicateEntry]) -> DurableMrfBacklogTracker {
     let mut tracker = DurableMrfBacklogTracker {
         available: true,
@@ -712,6 +716,10 @@ pub struct ReplicationPool<S: ReplicationStorage> {
 
     // MRF worker lifecycle
     mrf_worker_cancellations: Mutex<Vec<CancellationToken>>,
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     mrf_stop_tx: Sender<()>,
 
     // Worker size tracking
@@ -940,6 +948,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
     }
 
     /// Resizes worker priority and counts
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     pub async fn resize_worker_priority(
         &self,
         pri: ReplicationPriority,
@@ -1180,6 +1192,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
     }
 
     /// Queues an MRF save operation
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     async fn queue_mrf_save(&self, entry: MrfReplicateEntry) {
         let _ = self.queue_mrf_save_admission(entry, "mrf_worker").await;
     }
@@ -1651,6 +1667,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
     }
 
     /// Worker function for handling regular replication operations
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     async fn add_worker(
         &self,
         mut rx: Receiver<ReplicationOperation>,
@@ -1664,6 +1684,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
     }
 
     /// Worker function for handling large object replication operations
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     async fn add_large_worker(
         &self,
         mut rx: Receiver<ReplicationOperation>,
@@ -1678,6 +1702,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
     }
 
     /// Worker function for handling MRF (Most Recent Failures) operations
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     async fn add_mrf_worker(
         &self,
         mut rx: Receiver<ReplicationOperation>,
@@ -1691,6 +1719,10 @@ impl<S: ReplicationStorage> ReplicationPool<S> {
     }
 
     /// Delete resync metadata from replication resync state in memory
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     pub async fn delete_resync_metadata(&self, bucket: &str) {
         let mut status_map = self.resyncer.status_map.write().await;
         status_map.remove(bucket);

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

@@ -21,11 +21,31 @@ pub(crate) use rustfs_replication::{
     should_count_head_proxy_failure,
 };
 
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const RESYNC_META_FORMAT: u16 = rustfs_replication::resync::RESYNC_META_FORMAT;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const RESYNC_META_VERSION: u16 = rustfs_replication::resync::RESYNC_META_VERSION;
 pub(crate) const RESYNC_FILE_MAX_BYTES: usize = rustfs_replication::RESYNC_FILE_MAX_BYTES;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const WIRE_ZERO_TIME_UNIX: i64 = rustfs_replication::resync::WIRE_ZERO_TIME_UNIX;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const MRF_META_FORMAT: u16 = rustfs_replication::mrf::MRF_META_FORMAT;
+#[allow(
+    dead_code,
+    reason = "declared boundary surface for the ECStore replication split plan; no caller in this port (backlog#1823)"
+)]
 pub(crate) const MRF_META_VERSION: u16 = rustfs_replication::mrf::MRF_META_VERSION;
 
 fn map_replication_error(err: rustfs_replication::Error) -> Error {

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

@@ -122,6 +122,10 @@ const REPLICATION_TARGET_OFFLINE_ERROR_MARKERS: &[&str] = &[
     "tcp connect error",
 ];
 
+#[allow(
+    dead_code,
+    reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+)]
 const RESYNC_TIME_INTERVAL: TokioDuration = TokioDuration::from_secs(60);
 
 static WARNED_MONITOR_UNINIT: std::sync::Once = std::sync::Once::new();
@@ -328,6 +332,10 @@ fn bounded_resync_max_jobs(value: usize) -> usize {
 #[derive(Debug)]
 pub struct ReplicationResyncer {
     pub status_map: Arc<RwLock<HashMap<String, BucketReplicationResyncStatus>>>,
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     pub worker_size: usize,
     pub(crate) cancel_tokens: Arc<RwLock<HashMap<ResyncCancelKey, CancellationToken>>>,
     resync_admission: Arc<Semaphore>,
@@ -544,6 +552,10 @@ impl ReplicationResyncer {
             .is_some_and(|status| status.failed_count > 0)
     }
 
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     pub async fn persist_to_disk<S>(&self, cancel_token: CancellationToken, api: Arc<S>)
     where
         S: ReplicationObjectIO,

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

@@ -340,6 +340,10 @@ impl ReplicationStats {
     }
 
     /// Site replication update replica statistics
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity replication surface with no caller in this port (backlog#1823)"
+    )]
     fn sr_update_replica_stat(&self, size: i64) {
         self.sr_stats.replica_size.fetch_add(size, Ordering::Relaxed);
         self.sr_stats.replica_count.fetch_add(1, Ordering::Relaxed);

crates/ecstore/src/bucket/target/bucket_target.rs

@@ -59,6 +59,10 @@ impl fmt::Debug for Credentials {
 }
 
 #[derive(Debug, Deserialize, Serialize, Default, Clone)]
+#[allow(
+    dead_code,
+    reason = "MinIO-parity bucket-target service discriminator with no caller in this port (backlog#1823)"
+)]
 pub enum ServiceType {
     #[default]
     Replication,

crates/ecstore/src/bucket/utils.rs

@@ -73,23 +73,6 @@ pub fn check_valid_bucket_name_strict(bucket_name: &str) -> Result<()> {
     check_bucket_name_common(bucket_name, true)
 }
 
-pub fn check_valid_object_name_prefix(object_name: &str) -> Result<()> {
-    if object_name.len() > 1024 {
-        return Err(Error::other("Object name cannot be longer than 1024 characters"));
-    }
-    if !object_name.is_ascii() {
-        return Err(Error::other("Object name with non-UTF-8 strings are not supported"));
-    }
-    Ok(())
-}
-
-pub fn check_valid_object_name(object_name: &str) -> Result<()> {
-    if object_name.trim().is_empty() {
-        return Err(Error::other("Object name cannot be empty"));
-    }
-    check_valid_object_name_prefix(object_name)
-}
-
 pub fn deserialize<T>(input: &[u8]) -> xml::DeResult<T>
 where
     T: for<'xml> xml::Deserialize<'xml>,
@@ -100,6 +83,10 @@ where
     Ok(ans)
 }
 
+#[allow(
+    dead_code,
+    reason = "xml serialize helper with no caller in this port; the live sibling is deserialize (backlog#1823)"
+)]
 pub fn serialize_content<T: xml::SerializeContent>(val: &T) -> xml::SerResult<String> {
     let mut buf = Vec::with_capacity(256);
     {
@@ -186,15 +173,27 @@ pub fn is_valid_object_name(object: &str) -> bool {
 /// Client-facing reason attached to rejections of object keys that Win32/NTFS
 /// cannot represent as file paths (issue #3299). Deployments on Linux/macOS
 /// accept the full S3 key character set.
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 pub const WINDOWS_RESERVED_CHARACTERS_REASON: &str =
     "object key contains characters unsupported on Windows hosts (one of ':', '*', '?', '\"', '|', '<', '>')";
 
 /// Client-facing reason for path segments Windows can store but not address
 /// afterwards (issue #3449): trailing dot/space or reserved DOS device names.
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 pub const WINDOWS_RESERVED_SEGMENT_REASON: &str = "object key contains a path segment unsupported on Windows hosts (trailing dot or space, or a reserved device name such as NUL/CON/COM1)";
 
 /// Reserved DOS device names that shadow regular files on Windows, even when
 /// an extension is appended (e.g. `NUL.txt` resolves to the `NUL` device).
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 const WINDOWS_RESERVED_NAMES: &[&str] = &[
     "CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT1", "LPT2", "LPT3",
     "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
@@ -204,6 +203,10 @@ const WINDOWS_RESERVED_NAMES: &[&str] = &[
 /// the Win32 API cannot address afterwards (issue #3449): segments ending in a
 /// dot or a space, and reserved DOS device names — bare or with an extension
 /// (`NUL.txt`), matching classic Win32 path resolution semantics.
+#[allow(
+    dead_code,
+    reason = "live on Windows: callers sit inside the #[cfg(target_os = \"windows\")] block in check_object_name_for_length_and_slash (backlog#1823)"
+)]
 pub fn object_name_has_windows_incompatible_segment(object: &str) -> bool {
     object.split(['/', '\\']).any(|segment| {
         if segment.ends_with('.') || segment.ends_with(' ') {

crates/ecstore/src/bucket/versioning_sys.rs

@@ -90,6 +90,10 @@ impl BucketVersioningSys {
     /// caller's own instance context so a second in-process store never
     /// answers with the first instance's versioning state; falls back to the
     /// ambient system when the instance cell is not initialized.
+    #[allow(
+        dead_code,
+        reason = "instance-scoped seam (backlog#1052) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) async fn get_in(ctx: &crate::runtime::instance::InstanceContext, bucket: &str) -> Result<VersioningConfiguration> {
         if bucket == RUSTFS_META_BUCKET || bucket.starts_with(RUSTFS_META_BUCKET) {
             return Ok(VersioningConfiguration::default());

crates/ecstore/src/disk/disk_store.rs

@@ -637,14 +637,23 @@ impl Default for DiskOperationMetrics {
 }
 
 impl DiskOperationMetrics {
+    #[allow(
+        dead_code,
+        reason = "internal metrics recorder reached only from record() below (backlog#1823)"
+    )]
     fn record_call(&mut self) {
         self.lifetime_calls.fetch_add(1, Ordering::Relaxed);
     }
 
+    #[allow(
+        dead_code,
+        reason = "internal metrics recorder reached only from record() below (backlog#1823)"
+    )]
     fn record_latency(&mut self, now_sec: u64, elapsed: Duration) {
         self.record_latency_atomic(now_sec, elapsed);
     }
 
+    #[allow(dead_code, reason = "metrics roll-up with no caller in this port (backlog#1823)")]
     fn record(&mut self, now_sec: u64, elapsed: Duration) {
         self.record_call();
         self.record_latency(now_sec, elapsed);
@@ -770,6 +779,7 @@ impl DiskHealthTracker {
     }
 
     /// Set disk as faulty
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub fn set_faulty(&self) {
         self.status.store(DISK_HEALTH_FAULTY, Ordering::Release);
     }
@@ -850,6 +860,7 @@ impl DiskHealthTracker {
         became_offline
     }
 
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub fn mark_offline(&self, endpoint: &Endpoint, reason: &'static str) -> bool {
         let current = self.runtime_state();
         if current == RuntimeDriveHealthState::Offline {
@@ -980,11 +991,13 @@ impl DiskHealthTracker {
     }
 
     /// Get waiting operations count
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub fn waiting_count(&self) -> u32 {
         self.waiting.load(Ordering::Relaxed)
     }
 
     /// Get last success timestamp
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub fn last_success(&self) -> i64 {
         self.last_success.load(Ordering::Acquire)
     }
@@ -1026,21 +1039,6 @@ impl Default for DiskHealthTracker {
     }
 }
 
-/// Health check context key for tracking disk operations
-#[derive(Debug, Clone)]
-struct HealthDiskCtxKey;
-
-#[derive(Debug)]
-struct HealthDiskCtxValue {
-    last_success: Arc<AtomicI64>,
-}
-
-impl HealthDiskCtxValue {
-    fn log_success(&self) {
-        self.last_success.store(current_unix_nanos(), Ordering::Relaxed);
-    }
-}
-
 /// LocalDiskWrapper wraps a DiskStore with health tracking capabilities.
 /// This is similar to Go's xlStorageDiskIDCheck.
 #[derive(Debug, Clone)]
@@ -1072,10 +1070,6 @@ impl LocalDiskWrapper {
         )
     }
 
-    pub(crate) fn new_with_health(disk: Arc<LocalDisk>, health_check: bool, health: Arc<DiskHealthTracker>) -> Self {
-        Self::new_with_health_and_metrics(disk, health_check, health, Arc::new(DiskHealthMetricEpoch::default()))
-    }
-
     pub(crate) fn new_with_reconnect_state(
         disk: Arc<LocalDisk>,
         health_check: bool,
@@ -1438,20 +1432,6 @@ impl LocalDiskWrapper {
         }
     }
 
-    async fn check_id(&self, want_id: Option<Uuid>) -> Result<()> {
-        if want_id.is_none() {
-            return Ok(());
-        }
-
-        let stored_disk_id = self.disk.get_disk_id().await?;
-
-        if stored_disk_id != want_id {
-            return Err(Error::other(format!("Disk ID mismatch wanted {want_id:?}, got {stored_disk_id:?}")));
-        }
-
-        Ok(())
-    }
-
     /// Check if disk ID is stale
     async fn check_disk_stale(&self) -> Result<()> {
         let Some(current_disk_id) = *self.disk_id.read().await else {

crates/ecstore/src/disk/error_conv.rs

@@ -48,6 +48,7 @@ pub fn to_volume_error(io_err: std::io::Error) -> std::io::Error {
     }
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn to_disk_error(io_err: std::io::Error) -> std::io::Error {
     match io_err.kind() {
         std::io::ErrorKind::NotFound => DiskError::DiskNotFound.into(),

crates/ecstore/src/disk/fs.rs

@@ -178,6 +178,7 @@ pub async fn remove(path: impl AsRef<Path>) -> io::Result<()> {
     }
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub async fn remove_all(path: impl AsRef<Path>) -> io::Result<()> {
     // Try remove_file first; fall back to remove_dir_all if it's a directory
     match fs::remove_file(path.as_ref()).await {

crates/ecstore/src/disk/local.rs

@@ -665,6 +665,7 @@ async fn remove_empty_directory_tree_under_mount_lease(
 }
 
 #[cfg(unix)]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 async fn remove_empty_directory_tree_with(
     root: &Path,
     before_descend: impl FnMut(&Path) -> std::io::Result<()>,
@@ -1016,13 +1017,29 @@ fn record_direct_read_page_fault_delta(path: &'static str, stage: &'static str,
 /// When enabled, shard reads bypass the page cache using O_DIRECT flag.
 /// Requires aligned buffers (typically 512 bytes or 4096 bytes).
 /// Default: false (uses page cache via mmap/pread).
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const ENV_RUSTFS_OBJECT_DIRECT_IO_READ_ENABLE: &str = "RUSTFS_OBJECT_DIRECT_IO_READ_ENABLE";
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const DEFAULT_RUSTFS_OBJECT_DIRECT_IO_READ_ENABLE: bool = false;
 
 /// Minimum shard size threshold for O_DIRECT reads.
 /// Only shards larger than this threshold will use O_DIRECT.
 /// Default: 4MB.
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const ENV_RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD: &str = "RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD";
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const DEFAULT_RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD: usize = 4 * 1024 * 1024;
 
 /// Enable O_DIRECT for erasure shard / multipart part data writes (Linux only).
@@ -1036,7 +1053,15 @@ const DEFAULT_RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD: usize = 4 * 1024 * 1024;
 /// EINVAL/EOPNOTSUPP (tmpfs, overlayfs, 9p, ...) latch the path off and fall
 /// back to buffered writes for the whole disk. Non-Linux always falls back.
 /// Default: false (buffered writes via the page cache, as before).
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const ENV_RUSTFS_OBJECT_DIRECT_IO_WRITE_ENABLE: &str = "RUSTFS_OBJECT_DIRECT_IO_WRITE_ENABLE";
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const DEFAULT_RUSTFS_OBJECT_DIRECT_IO_WRITE_ENABLE: bool = false;
 const ENV_RUSTFS_OBJECT_MMAP_POPULATE_ENABLE: &str = "RUSTFS_OBJECT_MMAP_POPULATE_ENABLE";
 const DEFAULT_RUSTFS_OBJECT_MMAP_POPULATE_ENABLE: bool = false;
@@ -1095,12 +1120,14 @@ macro_rules! cached_read_env {
 
 cached_read_env! {
     /// Check if O_DIRECT reads are enabled.
+    #[allow(dead_code, reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)")]
     fn is_direct_io_read_enabled() -> bool =
         rustfs_utils::get_env_bool(ENV_RUSTFS_OBJECT_DIRECT_IO_READ_ENABLE, DEFAULT_RUSTFS_OBJECT_DIRECT_IO_READ_ENABLE);
 }
 
 cached_read_env! {
     /// Check if O_DIRECT shard/part data writes are enabled.
+    #[allow(dead_code, reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)")]
     fn is_direct_io_write_enabled() -> bool =
         rustfs_utils::get_env_bool(ENV_RUSTFS_OBJECT_DIRECT_IO_WRITE_ENABLE, DEFAULT_RUSTFS_OBJECT_DIRECT_IO_WRITE_ENABLE);
 }
@@ -1456,6 +1483,7 @@ pub(crate) fn effective_durability(volume: &str) -> DurabilityMode {
 
 cached_read_env! {
     /// Get the O_DIRECT read threshold size.
+    #[allow(dead_code, reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)")]
     fn get_direct_io_read_threshold() -> usize =
         rustfs_utils::get_env_usize(ENV_RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD, DEFAULT_RUSTFS_OBJECT_DIRECT_IO_READ_THRESHOLD);
 }
@@ -1673,12 +1701,20 @@ impl DirectIoWriteState {
 /// Target staging size for O_DIRECT writes, rounded up to the DIO alignment.
 /// Bounds the per-writer aligned bounce buffer and batches many shard blocks
 /// into one positioned write to keep the syscall count low.
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 const DIRECT_WRITE_STAGING_BYTES: usize = 1024 * 1024;
 
 /// Aligned bounce-buffer capacity for a given DIO alignment: the target staging
 /// size rounded up to a whole multiple of `align` so the buffer address, every
 /// flushed batch length, and every write offset stay alignment-correct.
 /// Platform-independent (no O_DIRECT), so it is unit-tested on any host.
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 fn direct_write_staging_capacity(align: usize) -> usize {
     debug_assert!(align.is_power_of_two() && align >= 512);
     DIRECT_WRITE_STAGING_BYTES.div_ceil(align) * align
@@ -1687,6 +1723,10 @@ fn direct_write_staging_capacity(align: usize) -> usize {
 /// Split `filled` staged bytes into the alignment-sized prefix written with
 /// O_DIRECT and the sub-alignment tail written buffered. Platform-independent,
 /// so the tail-boundary math is unit-tested on any host.
+#[allow(
+    dead_code,
+    reason = "platform-conditional: production callers are inside #[cfg(target_os = \"linux\")] blocks, so this reads as dead on non-Linux hosts (backlog#1823)"
+)]
 fn direct_write_tail_split(filled: usize, align: usize) -> (usize, usize) {
     let aligned = filled - (filled % align);
     (aligned, filled - aligned)
@@ -2142,6 +2182,7 @@ fn set_delete_version_fail_after_data_staged(path: &str) {
 }
 
 #[cfg(test)]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub(crate) fn set_delete_version_fail_after_commit(root: &Path, path: &str) {
     DELETE_VERSION_FAIL_AFTER_COMMIT
         .lock()
@@ -2447,6 +2488,10 @@ enum SyncMode {
     FileOnly,
 }
 
+#[allow(
+    dead_code,
+    reason = "reclaim bookkeeping fields written by Drop but never read back (backlog#1823)"
+)]
 struct FileCacheReclaimWriter {
     inner: File,
     reclaim_len: usize,
@@ -2454,6 +2499,10 @@ struct FileCacheReclaimWriter {
     reclaimed: bool,
 }
 
+#[allow(
+    dead_code,
+    reason = "reclaim bookkeeping fields written by Drop but never read back (backlog#1823)"
+)]
 struct FileCacheReclaimReader {
     inner: File,
     reclaim_offset: u64,
@@ -2519,6 +2568,10 @@ impl<R: AsyncRead + Unpin> AsyncRead for StallTimeoutReader<R> {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "reclaim metrics emitter reached only from the Linux-gated reclaim paths (backlog#1823)"
+)]
 fn record_file_cache_reclaim_success(kind: &'static str, reclaim_len: usize, started: std::time::Instant) {
     // Runs per read-stream page-cache reclaim window; skip the whole emission
     // (three metric-key constructions) when general metrics are disabled.
@@ -3071,6 +3124,7 @@ impl LocalIoBackend for StdBackend {
             use memmap2::MmapOptions;
             use std::time::{Duration as StdDuration, Instant as StdInstant};
 
+            #[allow(dead_code, reason = "mmap copy result slot kept beside the mapping it owns (backlog#1823)")]
             struct MmapCopyReadResult {
                 bytes: Bytes,
                 access_check_duration: StdDuration,
@@ -4704,6 +4758,10 @@ fn build_local_io_backend(root: PathBuf) -> Arc<dyn LocalIoBackend> {
     Arc::new(StdBackend::new(root))
 }
 
+#[allow(
+    dead_code,
+    reason = "path cache and cwd slots retained beside the disk root they derive from (backlog#1823)"
+)]
 pub struct LocalDisk {
     pub root: PathBuf,
     publication_root: os::PublicationRoot,
@@ -5490,6 +5548,7 @@ impl LocalDisk {
         Ok(Self::resolve_abs_path_from(&self.root, path.as_ref()))
     }
 
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     fn io_resolve_abs_path(&self, path: impl AsRef<Path>) -> PathBuf {
         let path_ref = path.as_ref();
         let path_str = path_ref.to_string_lossy();
@@ -5567,15 +5626,24 @@ impl LocalDisk {
     }
 
     // Check if a path is valid
+    #[allow(
+        dead_code,
+        reason = "method wrapper over the live free function check_local_disk_valid_path; no caller in this port (backlog#1823)"
+    )]
     fn check_valid_path<P: AsRef<Path>>(&self, path: P) -> Result<()> {
         check_local_disk_valid_path(self.io_root(), path)
     }
 
+    #[allow(
+        dead_code,
+        reason = "method wrapper over the live free function reject_local_disk_symlink_components; no caller in this port (backlog#1823)"
+    )]
     fn reject_symlink_components(&self, path: &Path) -> Result<()> {
         reject_local_disk_symlink_components(self.io_root(), path)
     }
 
     // Batch path generation with single lock acquisition
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     fn get_object_paths_batch(&self, requests: &[(String, String)]) -> Result<Vec<PathBuf>> {
         let mut results = Vec::with_capacity(requests.len());
         let mut cache_misses = Vec::new();
@@ -6488,6 +6556,7 @@ impl LocalDisk {
         Ok(f)
     }
 
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     async fn open_file_read_only(&self, path: impl AsRef<Path>) -> Result<File> {
         let f = super::fs::open_file(path.as_ref(), O_RDONLY).await.map_err(to_file_error)?;
         Ok(f)

crates/ecstore/src/disk/mod.rs

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 // #730: disk abstractions still carry staged health and direct-I/O migration paths.
-#![allow(dead_code)]
 
 pub mod disk_store;
 pub mod endpoint;
@@ -1114,6 +1113,10 @@ pub struct DiskInfo {
 }
 
 #[derive(Clone, Debug, Default)]
+#[allow(
+    dead_code,
+    reason = "MinIO-parity disk info shape with no constructor in this port (backlog#1823)"
+)]
 pub struct Info {
     pub total: u64,
     pub free: u64,
@@ -1372,6 +1375,7 @@ pub fn conv_part_err_to_int(err: &Option<Error>) -> usize {
     }
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn has_part_err(part_errs: &[usize]) -> bool {
     part_errs.iter().any(|err| *err != CHECK_PART_SUCCESS)
 }

crates/ecstore/src/disk/os.rs

@@ -571,6 +571,10 @@ fn regular_files(dir: &Path) -> io::Result<Vec<PathBuf>> {
 
 /// Fdatasync every regular file directly inside `dir`, then fsync the directory
 /// itself.
+#[allow(
+    dead_code,
+    reason = "reached only through sync_dir_files, whose callers are tests (backlog#1823)"
+)]
 pub fn sync_dir_files_std(dir: impl AsRef<Path>) -> io::Result<()> {
     for entry in std::fs::read_dir(dir.as_ref())? {
         let entry = entry?;
@@ -583,6 +587,7 @@ pub fn sync_dir_files_std(dir: impl AsRef<Path>) -> io::Result<()> {
 
 /// Async wrapper around [`sync_dir_files_std`]. Large directories flush files
 /// concurrently, bounded both per directory and process-wide.
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub async fn sync_dir_files(dir: impl AsRef<Path>) -> io::Result<()> {
     sync_dir_files_with_limiter(dir, Arc::new(Semaphore::new(MAX_PARALLEL_FILE_SYNCS))).await
 }
@@ -1809,10 +1814,6 @@ impl RenameCommitGuard {
         })
     }
 
-    pub(crate) fn lock_destination_directory_for_path_access(&self, directory: &Path) -> io::Result<RenameDestinationPathGuard> {
-        self.destination_directory_guard(directory, false)
-    }
-
     pub(crate) fn create_destination_directory_for_path_access(
         &self,
         directory: &Path,
@@ -2858,13 +2859,6 @@ pub async fn os_mkdir_all(dir_path: impl AsRef<Path>, base_dir: impl AsRef<Path>
     Ok(())
 }
 
-/// Check if a file exists.
-/// Returns true if the file exists, false otherwise.
-#[tracing::instrument(level = "debug", skip_all)]
-pub fn file_exists(path: impl AsRef<Path>) -> bool {
-    std::fs::metadata(path.as_ref()).map(|_| true).unwrap_or(false)
-}
-
 /// Whether an [`io::Error`] means "the directory is not empty".
 ///
 /// POSIX lets `rmdir`/`rename` report a non-empty directory as either

crates/ecstore/src/io_support/bitrot.rs

@@ -704,6 +704,7 @@ pub(crate) async fn create_bitrot_reader_from_bytes_with_stage_metrics(
 }
 
 #[allow(clippy::too_many_arguments)]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn create_deferred_bitrot_reader(
     inline_data: Option<Bytes>,
     disk: Option<DiskStore>,

crates/ecstore/src/set_disk/core/io_primitives.rs

@@ -180,11 +180,13 @@ pub(in crate::set_disk) enum GetCodecStreamingReaderBuildOutcome {
     Fallback(GetCodecStreamingFallbackReason),
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub(in crate::set_disk) struct MultipartCodecStreamingReader {
     pub(in crate::set_disk) readers: VecDeque<Box<dyn AsyncRead + Unpin + Send + Sync>>,
 }
 
 impl MultipartCodecStreamingReader {
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub(in crate::set_disk) fn new(readers: Vec<Box<dyn AsyncRead + Unpin + Send + Sync>>) -> Self {
         Self {
             readers: VecDeque::from(readers),
@@ -666,6 +668,60 @@ pub(in crate::set_disk) async fn data_read_early_stop_inline_body_miss_reason(
     parts_metadata: &[FileInfo],
     disks: &[Option<DiskStore>],
 ) -> Option<&'static str> {
+    if let Some(reason) = data_read_early_stop_inline_candidate_miss_reason(candidate) {
+        return Some(reason);
+    }
+
+    let Ok(erasure) = coding::Erasure::try_new_with_options(
+        candidate.erasure.data_blocks,
+        candidate.erasure.parity_blocks,
+        candidate.erasure.block_size,
+        candidate.uses_legacy_checksum,
+    ) else {
+        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_GEOMETRY);
+    };
+    let data_files =
+        match collect_inline_data_shard_fileinfos_by_index_or_reason(parts_metadata, candidate, erasure.data_shards, |index| {
+            disks.get(index).is_some_and(Option::is_some)
+        }) {
+            Ok(data_files) => data_files,
+            Err(reason) => return Some(reason),
+        };
+
+    let Some(part) = candidate.parts.first() else {
+        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_PART_SHAPE);
+    };
+    let Ok(object_size) = usize::try_from(candidate.size) else {
+        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_SIZE);
+    };
+    let checksum_info = candidate.erasure.get_checksum_info(part.number);
+    let checksum_algo = if candidate.uses_legacy_checksum && checksum_info.algorithm == HashAlgorithm::HighwayHash256S {
+        HashAlgorithm::HighwayHash256SLegacy
+    } else {
+        checksum_info.algorithm
+    };
+    let read_length = inline_erasure_shard_file_offset(
+        0,
+        object_size,
+        object_size,
+        candidate.erasure.block_size,
+        erasure.data_shards,
+        candidate.uses_legacy_checksum,
+    );
+    let shard_size = inline_erasure_shard_size(candidate.erasure.block_size, erasure.data_shards, candidate.uses_legacy_checksum);
+    let Ok(mut readers) =
+        build_inline_bitrot_readers_from_refs(&data_files, bucket, object, read_length, shard_size, &checksum_algo, false).await
+    else {
+        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_BODY_VERIFY);
+    };
+
+    match try_read_inline_data_shards_direct(&mut readers, erasure.data_shards, read_length, object_size).await {
+        Some(body) if body.len() == object_size => None,
+        _ => Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_BODY_VERIFY),
+    }
+}
+
+fn data_read_early_stop_inline_candidate_miss_reason(candidate: &FileInfo) -> Option<&'static str> {
     // `inline_data` excludes remote objects; this diagnostic reports them separately.
     if !rustfs_utils::http::contains_key_str(&candidate.metadata, rustfs_utils::http::SUFFIX_INLINE_DATA) {
         return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_NOT_INLINE);
@@ -703,51 +759,7 @@ pub(in crate::set_disk) async fn data_read_early_stop_inline_body_miss_reason(
     if !can_try_inline_data_shards_direct(object_size, candidate.erasure.block_size) {
         return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_SIZE);
     }
-
-    let Ok(erasure) = coding::Erasure::try_new_with_options(
-        candidate.erasure.data_blocks,
-        candidate.erasure.parity_blocks,
-        candidate.erasure.block_size,
-        candidate.uses_legacy_checksum,
-    ) else {
-        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_GEOMETRY);
-    };
-    let data_files =
-        match collect_inline_data_shard_fileinfos_by_index_or_reason(parts_metadata, candidate, erasure.data_shards, |index| {
-            disks.get(index).is_some_and(Option::is_some)
-        }) {
-            Ok(data_files) => data_files,
-            Err(reason) => return Some(reason),
-        };
-
-    let Some(part) = candidate.parts.first() else {
-        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_PART_SHAPE);
-    };
-    let checksum_info = candidate.erasure.get_checksum_info(part.number);
-    let checksum_algo = if candidate.uses_legacy_checksum && checksum_info.algorithm == HashAlgorithm::HighwayHash256S {
-        HashAlgorithm::HighwayHash256SLegacy
-    } else {
-        checksum_info.algorithm
-    };
-    let read_length = inline_erasure_shard_file_offset(
-        0,
-        object_size,
-        object_size,
-        candidate.erasure.block_size,
-        erasure.data_shards,
-        candidate.uses_legacy_checksum,
-    );
-    let shard_size = inline_erasure_shard_size(candidate.erasure.block_size, erasure.data_shards, candidate.uses_legacy_checksum);
-    let Ok(mut readers) =
-        build_inline_bitrot_readers_from_refs(&data_files, bucket, object, read_length, shard_size, &checksum_algo, false).await
-    else {
-        return Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_BODY_VERIFY);
-    };
-
-    match try_read_inline_data_shards_direct(&mut readers, erasure.data_shards, read_length, object_size).await {
-        Some(body) if body.len() == object_size => None,
-        _ => Some(GET_METADATA_EARLY_STOP_REASON_DATA_READ_INLINE_BODY_VERIFY),
-    }
+    None
 }
 
 fn data_read_inline_missing_shards_are_pending(
@@ -1836,6 +1848,7 @@ pub(in crate::set_disk) async fn create_bitrot_readers_until_quorum_all_shards(
 }
 
 #[allow(clippy::too_many_arguments)]
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub(in crate::set_disk) async fn create_bitrot_readers_until_quorum(
     files: &[FileInfo],
     disks: &[Option<DiskStore>],
@@ -2126,6 +2139,7 @@ pub(in crate::set_disk) async fn create_data_block_bitrot_readers(
     setup
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub(in crate::set_disk) async fn collect_read_multiple_results<F>(
     tasks: Vec<F>,
     read_quorum: usize,
@@ -2442,6 +2456,7 @@ impl SetDisks {
         let bucket: Arc<str> = Arc::from(bucket);
         let object: Arc<str> = Arc::from(object);
         let version_id: Arc<str> = Arc::from(version_id);
+        let slowtail_fault = get_metadata_slowtail_fault_request(bucket.as_ref(), object.as_ref(), read_data);
         let futures = disks.iter().enumerate().map(|(disk_index, disk)| {
             let disk = disk.clone();
             let task_opts = opts;
@@ -2449,10 +2464,14 @@ impl SetDisks {
             let bucket = bucket.clone();
             let object = object.clone();
             let version_id = version_id.clone();
+            let slowtail_fault = slowtail_fault.clone();
             tokio::spawn(async move {
                 let response_start = observe.then(Instant::now);
                 let result = if let Some(disk) = disk {
                     Self::record_read_version_call(&object, disk_index);
+                    if let Some(delay) = slowtail_fault.as_ref().and_then(|fault| fault.delay_for_disk(disk_index)) {
+                        tokio::time::sleep(delay).await;
+                    }
                     disk.read_version(&org_bucket, &bucket, &object, &version_id, &task_opts)
                         .await
                 } else {
@@ -2548,6 +2567,7 @@ impl SetDisks {
         let mut scheduled_count = 0usize;
         let mut force_full_wait = false;
         let mut final_miss_reason_override = None;
+        let slowtail_fault = get_metadata_slowtail_fault_request(bucket.as_ref(), object.as_ref(), read_data);
         let spawn_read_version =
             |join_set: &mut JoinSet<(usize, disk::error::Result<FileInfo>, Duration)>, index: usize, disk: Option<DiskStore>| {
                 let task_opts = opts;
@@ -2555,6 +2575,7 @@ impl SetDisks {
                 let bucket = bucket.clone();
                 let object = object.clone();
                 let version_id = version_id.clone();
+                let slowtail_fault = slowtail_fault.clone();
                 join_set.spawn(async move {
                     let response_start = Instant::now();
                     let result = if let Some(disk) = disk {
@@ -2563,6 +2584,9 @@ impl SetDisks {
                         Self::record_read_version_call(&object, index);
                         #[cfg(test)]
                         Self::read_version_fanout_barrier(&object, index).await;
+                        if let Some(delay) = slowtail_fault.as_ref().and_then(|fault| fault.delay_for_disk(index)) {
+                            tokio::time::sleep(delay).await;
+                        }
                         disk.read_version(&org_bucket, &bucket, &object, &version_id, &task_opts)
                             .await
                     } else {
@@ -2596,6 +2620,14 @@ impl SetDisks {
                     Ok(file_info) => {
                         observations.push(MetadataFanoutObservation::from_file_info(&file_info, elapsed));
                         accumulator.observe_file_info(&file_info);
+                        if bounded_fanout
+                            && read_data
+                            && !force_full_wait
+                            && let Some(reason) = data_read_early_stop_inline_candidate_miss_reason(&file_info)
+                        {
+                            force_full_wait = true;
+                            final_miss_reason_override.get_or_insert(reason);
+                        }
                         if let Some(slot) = ress.get_mut(index) {
                             *slot = file_info;
                         }
@@ -2955,6 +2987,7 @@ impl SetDisks {
         (meta_file_infos, errs)
     }
 
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub(in crate::set_disk) async fn read_multiple_files(
         disks: &[Option<DiskStore>],
         req: ReadMultipleReq,
@@ -2988,14 +3021,11 @@ impl SetDisks {
             });
         }
 
-        let (ress, errors) = match collect_read_multiple_results(futures, read_quorum).await {
+        let (ress, _errors) = match collect_read_multiple_results(futures, read_quorum).await {
             Ok(collected) => collected,
             Err(()) => return empty_quorum_result(),
         };
 
-        // debug!("ReadMultipleResp ress {:?}", ress);
-        // debug!("ReadMultipleResp errors {:?}", errors);
-
         let mut ret = Vec::with_capacity(req.files.len());
 
         for want in req.files.iter() {
@@ -3134,6 +3164,7 @@ pub(in crate::set_disk) struct RenameDataCommit {
     pub(in crate::set_disk) committed_file_info: FileInfo,
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 type RenameDataLegacyTuple = (
     Vec<Option<DiskStore>>,
     RenameConvergence,
@@ -3143,6 +3174,7 @@ type RenameDataLegacyTuple = (
 );
 
 impl RenameDataCommit {
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     fn into_legacy_tuple(self) -> RenameDataLegacyTuple {
         (
             self.online_disks,
@@ -3261,6 +3293,7 @@ impl SetDisks {
 
     #[tracing::instrument(level = "debug", skip(disks, file_infos))]
     #[allow(clippy::type_complexity)]
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub(in crate::set_disk) async fn rename_data(
         disks: &[Option<DiskStore>],
         src_bucket: &str,
@@ -5073,6 +5106,7 @@ fn is_cleanup_not_found(e: &DiskError) -> bool {
 /// normalized to `DiskNotFound`: a panic is not a "disk absent" condition and
 /// must not be silently swallowed as an ignorable error (fixes the historical
 /// `Unexpected`/`DiskNotFound` misclassification).
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn map_cleanup_join_result(joined: std::result::Result<Option<DiskError>, tokio::task::JoinError>) -> Option<DiskError> {
     match joined {
         Ok(res) => res,
@@ -5297,6 +5331,7 @@ pub(in crate::set_disk) mod rename_fanout_barrier_phase {
     /// The per-disk old-data-dir cleanup phase of the commit fan-out.
     pub const CLEANUP: &str = "cleanup";
     /// The per-disk `read_version` phase of metadata read fan-out.
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub const READ_VERSION: &str = "read_version";
 }
 
@@ -5734,6 +5769,130 @@ mod tests {
         (dirs, disks)
     }
 
+    #[test]
+    fn metadata_slowtail_fault_delay_parses_and_filters_request() {
+        temp_env::with_vars(
+            [
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS, Some("25")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS, Some("1,3")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_BUCKET, Some("bench-bucket")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_OBJECT_PREFIX, Some("objects/")),
+            ],
+            || {
+                assert_eq!(
+                    get_metadata_slowtail_fault_delay("bench-bucket", "objects/000001", 3, true),
+                    Some(Duration::from_millis(25))
+                );
+                assert!(get_metadata_slowtail_fault_delay("bench-bucket", "objects/000001", 2, true).is_none());
+                assert!(get_metadata_slowtail_fault_delay("other-bucket", "objects/000001", 3, true).is_none());
+                assert!(get_metadata_slowtail_fault_delay("bench-bucket", "other/000001", 3, true).is_none());
+                assert!(get_metadata_slowtail_fault_delay("bench-bucket", "objects/000001", 3, false).is_none());
+            },
+        );
+    }
+
+    #[test]
+    fn metadata_slowtail_fault_delay_disables_invalid_disk_list() {
+        temp_env::with_vars(
+            [
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS, Some("25")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS, Some("1,nope")),
+            ],
+            || {
+                assert!(get_metadata_slowtail_fault_delay("bucket", "object", 1, true).is_none());
+            },
+        );
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn metadata_slowtail_fault_delays_only_data_read_metadata_task() {
+        const DISKS: usize = 4;
+        let bucket = "metadata-slowtail-fault-bucket";
+        let object = "objects/metadata-slowtail-fault-object";
+        let (dirs, disks) = call_counter_local_disks(bucket, DISKS).await;
+        install_metadata_fanout_fileinfo(&disks, bucket, object, None).await;
+
+        temp_env::async_with_vars(
+            [
+                (ENV_RUSTFS_GET_METADATA_EARLY_STOP_ENABLE, Some("false")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS, Some("150")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS, Some("3")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_BUCKET, Some(bucket)),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_OBJECT_PREFIX, Some("objects/")),
+            ],
+            async {
+                let read_without_data =
+                    SetDisks::read_all_fileinfo_observed(&disks, bucket, bucket, object, "", false, false, false, true, 2);
+                tokio::time::timeout(Duration::from_millis(100), read_without_data)
+                    .await
+                    .expect("non-data metadata fanout must not be delayed by the data-read slowtail hook")
+                    .expect("metadata fanout without read_data should resolve");
+
+                let mut read_with_data = Box::pin(SetDisks::read_all_fileinfo_observed(
+                    &disks, bucket, bucket, object, "", true, false, false, true, 2,
+                ));
+                assert!(
+                    tokio::time::timeout(Duration::from_millis(40), &mut read_with_data)
+                        .await
+                        .is_err(),
+                    "data-read metadata fanout must wait for the injected slow read_version response"
+                );
+                let (parts_metadata, errs, diagnostics) = tokio::time::timeout(Duration::from_secs(2), read_with_data)
+                    .await
+                    .expect("injected slowtail should eventually complete")
+                    .expect("data-read metadata fanout should resolve");
+                assert_eq!(parts_metadata.iter().filter(|fi| fi.name == object).count(), DISKS);
+                assert!(errs.iter().all(Option::is_none));
+                assert_eq!(diagnostics.total_responses(), DISKS);
+            },
+        )
+        .await;
+
+        drop(dirs);
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn metadata_slowtail_fault_delays_early_stop_metadata_task() {
+        const DISKS: usize = 4;
+        let bucket = "metadata-slowtail-early-stop-bucket";
+        let object = "objects/metadata-slowtail-early-stop-object";
+        let (dirs, disks) = call_counter_local_disks(bucket, DISKS).await;
+        install_metadata_fanout_fileinfo(&disks, bucket, object, None).await;
+
+        temp_env::async_with_vars(
+            [
+                (ENV_RUSTFS_GET_METADATA_EARLY_STOP_ENABLE, Some("true")),
+                (ENV_RUSTFS_GET_METADATA_DATA_READ_EARLY_STOP_ENABLE, Some("true")),
+                (ENV_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT, Some("false")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS, Some("150")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS, Some("3")),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_BUCKET, Some(bucket)),
+                (ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_OBJECT_PREFIX, Some("objects/")),
+            ],
+            async {
+                let mut read_with_data = Box::pin(SetDisks::read_all_fileinfo_observed(
+                    &disks, bucket, bucket, object, "", true, false, false, true, 2,
+                ));
+                assert!(
+                    tokio::time::timeout(Duration::from_millis(40), &mut read_with_data)
+                        .await
+                        .is_err(),
+                    "early-stop metadata fanout must still wait for the injected slow response after fallback to full wait"
+                );
+                let (parts_metadata, errs, diagnostics) = tokio::time::timeout(Duration::from_secs(2), read_with_data)
+                    .await
+                    .expect("injected early-stop slowtail should eventually complete")
+                    .expect("early-stop metadata fanout should resolve");
+                assert_eq!(parts_metadata.iter().filter(|fi| fi.name == object).count(), DISKS);
+                assert!(errs.iter().all(Option::is_none));
+                assert_eq!(diagnostics.total_responses(), DISKS);
+            },
+        )
+        .await;
+
+        drop(dirs);
+    }
+
     /// Demo / regression guard for the backlog#1325 per-disk call counters.
     ///
     /// The metadata fan-out issues each `read_version` inside its own
@@ -7081,7 +7240,7 @@ mod tests {
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-    async fn bounded_non_inline_data_get_hedges_then_waits_for_full_fanout() {
+    async fn bounded_non_inline_data_get_immediately_forces_full_fanout() {
         const DISKS: usize = 4;
         let bucket = "bounded-data-get-hedge-bucket";
         let object = "bounded-data-get-hedge-object";
@@ -7112,7 +7271,7 @@ mod tests {
                     }
                 })
                 .await
-                .expect("bounded data-read fanout should hedge by starting the spare disk");
+                .expect("bounded non-inline data-read fanout should immediately schedule the spare disk");
 
                 let pending = tokio::time::timeout(BARRIER_PAUSE_GUARD, &mut read).await;
                 assert!(
@@ -7128,7 +7287,7 @@ mod tests {
                 assert_eq!(
                     calls.total(disk_call_counters::KIND_READ_VERSION),
                     DISKS as u64,
-                    "bounded data-read fanout should issue the paused disk plus one spare hedge"
+                    "bounded non-inline data-read fanout should issue the paused disk plus the remaining spare"
                 );
                 assert_eq!(diagnostics.total_responses(), DISKS);
                 assert_eq!(parts_metadata.iter().filter(|fi| fi.name == object).count(), DISKS);
@@ -7155,16 +7314,42 @@ mod tests {
                 ("RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT", None::<&str>),
             ],
             async {
+                let barrier = rename_fanout_barrier::arm(object, 2, rename_fanout_barrier::PHASE_READ_VERSION);
                 let calls = disk_call_counters::observe(object);
-                let (parts_metadata, errs, diagnostics) =
-                    SetDisks::read_all_fileinfo_observed(&disks, bucket, bucket, object, "", true, false, false, true, 2)
+                let disks_for_read = disks.clone();
+                let mut read = tokio::spawn(async move {
+                    SetDisks::read_all_fileinfo_observed(&disks_for_read, bucket, bucket, object, "", true, false, false, true, 2)
                         .await
-                        .expect("default data-read metadata should resolve");
+                });
+
+                tokio::time::timeout(BARRIER_PAUSE_GUARD, barrier.wait_until_paused())
+                    .await
+                    .expect("default bounded non-inline read should schedule the paused metadata task");
+                tokio::time::timeout(BARRIER_PAUSE_GUARD, async {
+                    while calls.for_disk(disk_call_counters::KIND_READ_VERSION, 3) == 0 {
+                        tokio::task::yield_now().await;
+                    }
+                })
+                .await
+                .expect(
+                    "default bounded non-inline read should immediately force full fanout after the first non-inline response",
+                );
+
+                let pending = tokio::time::timeout(BARRIER_PAUSE_GUARD, &mut read).await;
+                assert!(
+                    pending.is_err(),
+                    "default non-inline data reads must not return before the paused metadata response"
+                );
+                barrier.release();
+                let (parts_metadata, errs, diagnostics) = read
+                    .await
+                    .expect("metadata read task should not panic")
+                    .expect("default data-read metadata should resolve");
 
                 assert_eq!(
                     calls.total(disk_call_counters::KIND_READ_VERSION),
                     DISKS as u64,
-                    "default non-inline GET data-read metadata must keep full fanout for read-failure tolerance"
+                    "default non-inline GET data-read metadata must keep full fanout without waiting for a quorum miss first"
                 );
                 assert_eq!(diagnostics.total_responses(), DISKS);
                 assert_eq!(parts_metadata.iter().filter(|fi| fi.name == object).count(), DISKS);

crates/ecstore/src/set_disk/ctx.rs

@@ -42,12 +42,20 @@ impl<'a> SetDisksCtx<'a> {
     }
 
     /// The borrowed core, for state not yet fronted by a typed accessor.
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn core(&self) -> &'a SetDisks {
         self.core
     }
 
     // --- Immutable topology / config (fixed after construction) ---
 
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn set_index(&self) -> usize {
         self.core.set_index
     }
@@ -56,14 +64,26 @@ impl<'a> SetDisksCtx<'a> {
         self.core.pool_index
     }
 
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn set_drive_count(&self) -> usize {
         self.core.set_drive_count
     }
 
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn default_parity_count(&self) -> usize {
         self.core.default_parity_count
     }
 
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn set_endpoints(&self) -> &'a [Endpoint] {
         &self.core.set_endpoints
     }
@@ -72,6 +92,10 @@ impl<'a> SetDisksCtx<'a> {
         &self.core.format
     }
 
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn locker_owner(&self) -> &'a str {
         &self.core.locker_owner
     }
@@ -84,6 +108,10 @@ impl<'a> SetDisksCtx<'a> {
 
     // --- Locker trio ---
 
+    #[allow(
+        dead_code,
+        reason = "SetDisks split seam (backlog#815) with no caller in this port (backlog#1823)"
+    )]
     pub(crate) fn lockers(&self) -> &'a [Arc<dyn LockClient>] {
         &self.core.lockers
     }

crates/ecstore/src/set_disk/mod.rs

@@ -39,7 +39,6 @@
 //! - `metadata.rs`, `replication.rs`, `shard_source.rs` — supporting helpers.
 
 // #730: SetDisks still hosts staged read/heal/write migration helpers.
-#![allow(dead_code)]
 #![allow(unused_imports)]
 #![allow(unused_variables)]
 
@@ -103,9 +102,7 @@ use crate::storage_api_contracts::{
 };
 use crate::store::utils::is_reserved_or_invalid_bucket;
 use crate::{
-    bucket::lifecycle::bucket_lifecycle_ops::{
-        LifecycleOps, gen_transition_objname, get_transitioned_object_reader_with_tier_manager, put_restore_opts,
-    },
+    bucket::lifecycle::bucket_lifecycle_ops::{LifecycleOps, get_transitioned_object_reader_with_tier_manager, put_restore_opts},
     cache_value::metacache_set::{ListPathRawOptions, list_path_raw},
     config::storageclass,
     disk::{
@@ -177,15 +174,14 @@ use std::future::Future;
 use std::hash::{BuildHasher, Hash, Hasher};
 use std::mem::{self};
 use std::pin::Pin;
-use std::sync::OnceLock;
 use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+use std::sync::{Arc, OnceLock};
 use std::task::{Context, Poll};
 use std::time::{Instant, SystemTime, UNIX_EPOCH};
 use std::{
     collections::{HashMap, HashSet},
     io::{Cursor, Write},
     path::Path,
-    sync::Arc,
     time::Duration,
 };
 use time::OffsetDateTime;
@@ -624,7 +620,9 @@ fn adaptive_duplex_buffer_size(object_size: i64) -> usize {
 // Each flag has a corresponding `*_ROLLOUT_PCT` for percentage-based gradual rollout.
 // ============================================================================
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 const DISK_ONLINE_TIMEOUT: Duration = Duration::from_secs(1);
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 const DISK_HEALTH_CACHE_TTL: Duration = Duration::from_millis(750);
 const GET_OBJECT_METADATA_CACHE_TTL: Duration = Duration::from_secs(2); // Increased from 250ms to 2s
 const DEFAULT_GET_OBJECT_METADATA_CACHE_MAX_ENTRIES: usize = 4096; // Increased from 1024 to 4096
@@ -698,7 +696,15 @@ const ENV_RUSTFS_GET_METADATA_EARLY_STOP_ENABLE: &str = "RUSTFS_GET_METADATA_EAR
 // the env var to `false` to fall back to full-wait metadata fanout.
 const DEFAULT_RUSTFS_GET_METADATA_EARLY_STOP_ENABLE: bool = true;
 
+#[allow(
+    dead_code,
+    reason = "percentage-rollout facet of the metadata early-stop switch; its predicate has no caller while the sibling enable flag is live (backlog#1823)"
+)]
 const ENV_RUSTFS_GET_METADATA_EARLY_STOP_ROLLOUT_PCT: &str = "RUSTFS_GET_METADATA_EARLY_STOP_ROLLOUT_PCT";
+#[allow(
+    dead_code,
+    reason = "percentage-rollout facet of the metadata early-stop switch; its predicate has no caller while the sibling enable flag is live (backlog#1823)"
+)]
 const DEFAULT_RUSTFS_GET_METADATA_EARLY_STOP_ROLLOUT_PCT: u32 = 100;
 
 const ENV_RUSTFS_GET_METADATA_VERSION_EARLY_STOP_ENABLE: &str = "RUSTFS_GET_METADATA_VERSION_EARLY_STOP_ENABLE";
@@ -708,7 +714,12 @@ const ENV_RUSTFS_GET_METADATA_DATA_READ_EARLY_STOP_ENABLE: &str = "RUSTFS_GET_ME
 const DEFAULT_RUSTFS_GET_METADATA_DATA_READ_EARLY_STOP_ENABLE: bool = true;
 
 const ENV_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT: &str = "RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT";
-const DEFAULT_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT: bool = false;
+const DEFAULT_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT: bool = true;
+
+const ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS: &str = "RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS";
+const ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS: &str = "RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS";
+const ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_BUCKET: &str = "RUSTFS_GET_METADATA_SLOWTAIL_FAULT_BUCKET";
+const ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_OBJECT_PREFIX: &str = "RUSTFS_GET_METADATA_SLOWTAIL_FAULT_OBJECT_PREFIX";
 
 // --- Multipart Reader-Setup Prefetch Configuration (backlog#870) ---
 
@@ -910,6 +921,10 @@ mod prepared_get_object_metadata_tests {
             .expect("test should find an object whose initial fanout covers both data shards")
     }
 
+    #[allow(
+        dead_code,
+        reason = "test fixture no assertion in this module uses today; the live namesake lives in io_primitives tests (backlog#1823)"
+    )]
     fn bounded_spare_disk_index(bucket: &str, object: &str) -> usize {
         *bounded_metadata_fanout_order(bucket, object, 4, 2)
             .get(3)
@@ -1110,7 +1125,10 @@ mod prepared_get_object_metadata_tests {
 
         assert_eq!(object_size, payload.len() as i64);
         assert_eq!(restored, payload);
-        assert_eq!(calls_total, 4, "default production GET should eagerly schedule the full metadata fanout");
+        assert_eq!(
+            calls_total, 4,
+            "default production inline GET should schedule the initial bounded quorum plus one hedge"
+        );
         assert_eq!(
             recorder.histogram_values(
                 "rustfs_io_get_object_metadata_fanout_scheduled",
@@ -1684,6 +1702,95 @@ fn is_get_metadata_early_stop_bounded_fanout_enabled() -> bool {
     }
 }
 
+#[derive(Debug)]
+struct GetMetadataSlowtailFaultConfig {
+    delay: Duration,
+    disks: Arc<[usize]>,
+    bucket: Option<String>,
+    object_prefix: Option<String>,
+}
+
+#[derive(Clone, Debug)]
+struct GetMetadataSlowtailFaultRequest {
+    delay: Duration,
+    disks: Arc<[usize]>,
+}
+
+impl GetMetadataSlowtailFaultRequest {
+    fn delay_for_disk(&self, disk_index: usize) -> Option<Duration> {
+        self.disks.contains(&disk_index).then_some(self.delay)
+    }
+}
+
+fn parse_get_metadata_slowtail_fault_disks(raw: &str) -> Option<Vec<usize>> {
+    let mut disks = Vec::new();
+    for item in raw.split(',').map(str::trim).filter(|item| !item.is_empty()) {
+        let Ok(index) = item.parse::<usize>() else {
+            return None;
+        };
+        if !disks.contains(&index) {
+            disks.push(index);
+        }
+    }
+    (!disks.is_empty()).then_some(disks)
+}
+
+fn load_get_metadata_slowtail_fault_config() -> Option<GetMetadataSlowtailFaultConfig> {
+    let delay_ms = rustfs_utils::get_env_u64(ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DELAY_MS, 0);
+    if delay_ms == 0 {
+        return None;
+    }
+    let disks = parse_get_metadata_slowtail_fault_disks(&std::env::var(ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_DISKS).ok()?)?;
+    let bucket = std::env::var(ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_BUCKET)
+        .ok()
+        .filter(|value| !value.is_empty());
+    let object_prefix = std::env::var(ENV_RUSTFS_GET_METADATA_SLOWTAIL_FAULT_OBJECT_PREFIX)
+        .ok()
+        .filter(|value| !value.is_empty());
+    Some(GetMetadataSlowtailFaultConfig {
+        delay: Duration::from_millis(delay_ms),
+        disks: Arc::from(disks.into_boxed_slice()),
+        bucket,
+        object_prefix,
+    })
+}
+
+fn get_metadata_slowtail_fault_request(bucket: &str, object: &str, read_data: bool) -> Option<GetMetadataSlowtailFaultRequest> {
+    if !read_data {
+        return None;
+    }
+
+    #[cfg(test)]
+    let config = load_get_metadata_slowtail_fault_config();
+    #[cfg(test)]
+    let config = config.as_ref()?;
+    #[cfg(not(test))]
+    let config = ({
+        static CACHED: OnceLock<Option<GetMetadataSlowtailFaultConfig>> = OnceLock::new();
+        CACHED.get_or_init(load_get_metadata_slowtail_fault_config).as_ref()
+    })?;
+
+    if let Some(expected_bucket) = &config.bucket
+        && expected_bucket != bucket
+    {
+        return None;
+    }
+    if let Some(expected_prefix) = &config.object_prefix
+        && !object.starts_with(expected_prefix)
+    {
+        return None;
+    }
+    Some(GetMetadataSlowtailFaultRequest {
+        delay: config.delay,
+        disks: config.disks.clone(),
+    })
+}
+
+#[cfg(test)]
+fn get_metadata_slowtail_fault_delay(bucket: &str, object: &str, disk_index: usize, read_data: bool) -> Option<Duration> {
+    get_metadata_slowtail_fault_request(bucket, object, read_data)?.delay_for_disk(disk_index)
+}
+
 /// Check if multipart reads prefetch the next part's bitrot reader setup
 /// while the current part decodes (backlog#870).
 ///
@@ -1709,6 +1816,10 @@ fn is_multipart_reader_setup_prefetch_enabled() -> bool {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "percentage-rollout facet of the metadata early-stop switch; its predicate has no caller while the sibling enable flag is live (backlog#1823)"
+)]
 fn get_metadata_early_stop_rollout_pct() -> u32 {
     static CACHED: OnceLock<u32> = OnceLock::new();
     *CACHED.get_or_init(|| {
@@ -1748,6 +1859,10 @@ fn should_use_codec_streaming(config: GetCodecStreamingConfig, bucket: &str, obj
 }
 
 /// Should this specific request use metadata early-stop?
+#[allow(
+    dead_code,
+    reason = "percentage-rollout facet of the metadata early-stop switch; its predicate has no caller while the sibling enable flag is live (backlog#1823)"
+)]
 pub fn should_use_metadata_early_stop(bucket: &str, object: &str) -> bool {
     let base = is_get_metadata_early_stop_enabled();
     let pct = get_metadata_early_stop_rollout_pct();
@@ -2181,6 +2296,7 @@ fn classify_get_codec_streaming_object_class(
     GetCodecStreamingObjectClass::PlainSinglePart
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn is_get_small_object_direct_memory_eligible_with_threshold(
     range: &Option<HTTPRangeSpec>,
     object_info: &ObjectInfo,
@@ -2786,6 +2902,7 @@ pub struct SetDisks {
     /// Stable namespace shared by every object lock created for this set.
     set_lock_namespace: Arc<str>,
     pub format: FormatV3,
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     disk_health_cache: Arc<RwLock<Vec<Option<DiskHealthEntry>>>>,
     get_object_metadata_cache: moka::future::Cache<GetObjectMetadataCacheKey, Arc<GetObjectMetadataCacheEntry>>,
     get_object_metadata_cache_hash_builder: std::collections::hash_map::RandomState,
@@ -3061,11 +3178,13 @@ struct GetObjectMetadataCacheEntry {
 
 #[derive(Clone, Debug)]
 struct DiskHealthEntry {
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     last_check: Instant,
     online: bool,
 }
 
 impl DiskHealthEntry {
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     fn cached_value(&self) -> Option<bool> {
         if self.last_check.elapsed() <= DISK_HEALTH_CACHE_TTL {
             Some(self.online)
@@ -3659,6 +3778,7 @@ fn multipart_put_large_batch_min_size_bytes() -> usize {
     })
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn classify_small_write_path(is_inline_buffer: bool, object_size: i64, block_size: usize) -> SmallWritePath {
     if should_use_inline_small_fast_path(is_inline_buffer, object_size, block_size) {
         SmallWritePath::Inline
@@ -4237,6 +4357,7 @@ fn check_object_lock_retention_update(bucket: &str, object: &str, obj_info: &Obj
 ///
 /// Fail closed: when bucket metadata cannot be resolved the check stays on, so
 /// object-lock protection is never skipped because of a metadata lookup miss.
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub(crate) fn object_lock_delete_check_required(bucket_meta: Option<&crate::bucket::metadata::BucketMetadata>) -> bool {
     bucket_meta.is_none_or(|meta| meta.object_locking())
 }
@@ -4512,15 +4633,6 @@ impl Hash for ObjProps {
     }
 }
 
-#[derive(Default, Clone, Debug)]
-pub struct HealEntryResult {
-    pub bytes: usize,
-    pub success: bool,
-    pub skipped: bool,
-    pub entry_done: bool,
-    pub name: String,
-}
-
 fn is_object_dangling(
     meta_arr: &[FileInfo],
     errs: &[Option<DiskError>],
@@ -5297,6 +5409,7 @@ pub fn is_valid_storage_class(storage_class: &str) -> bool {
 }
 
 /// Returns true if the storage class is a cold storage tier that requires special handling
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn is_cold_storage_class(storage_class: &str) -> bool {
     matches!(
         storage_class,
@@ -5305,6 +5418,7 @@ pub fn is_cold_storage_class(storage_class: &str) -> bool {
 }
 
 /// Returns true if the storage class is an infrequent access tier
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 pub fn is_infrequent_access_class(storage_class: &str) -> bool {
     matches!(
         storage_class,

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

@@ -453,7 +453,9 @@ impl SetDisks {
             ..Default::default()
         };
 
-        let write_lock_guard = if !opts.no_lock {
+        // Bound, not `_`: this guard must live to the end of the scope. A bare
+        // `_` would drop it here and release the namespace write lock.
+        let _write_lock_guard = if !opts.no_lock {
             let ns_lock = self.new_ns_lock(bucket, object).await?;
             Some(
                 ns_lock
@@ -996,7 +998,7 @@ impl SetDisks {
                                                 readers.push(None);
                                                 continue;
                                             }
-                                            Err(e) => {
+                                            Err(_e) => {
                                                 readers.push(None);
                                                 continue;
                                             }
@@ -1545,6 +1547,9 @@ impl SetDisks {
 
         for candidate in candidates.iter_mut().filter(|candidate| candidate.local_payload) {
             for (disk_index, disk) in disks.iter().enumerate() {
+                // Only the #[cfg(test)] fault-injection branch below reads this.
+                #[cfg(not(test))]
+                let _ = disk_index;
                 let Some(disk) = disk else {
                     return Ok(DanglingDeleteSafety::UnsafeToDelete);
                 };
@@ -1716,6 +1721,10 @@ impl SetDisks {
         Ok((result, None))
     }
 
+    #[allow(
+        dead_code,
+        reason = "lock-taking wrapper over the live heal_object_dir_locked; only comments reference it (backlog#1823)"
+    )]
     #[tracing::instrument(level = "trace", skip(self), fields(bucket = %bucket, object = %object))]
     pub(in crate::set_disk) async fn heal_object_dir(
         &self,

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

@@ -66,6 +66,7 @@ impl crate::storage_api_contracts::namespace::NamespaceLocking for SetDisks {
 }
 
 impl SetDisks {
+    #[allow(dead_code, reason = "lock diagnostics formatter with no caller in this port (backlog#1823)")]
     pub(in crate::set_disk) fn format_lock_error(&self, bucket: &str, object: &str, mode: &str, err: &LockResult) -> String {
         match err {
             LockResult::Timeout => {
@@ -79,6 +80,7 @@ impl SetDisks {
         }
     }
 
+    #[allow(dead_code, reason = "lock diagnostics formatter with no caller in this port (backlog#1823)")]
     pub(in crate::set_disk) fn format_lock_error_from_error(
         &self,
         bucket: &str,
@@ -143,6 +145,7 @@ impl SetDisks {
         disks
     }
 
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub(in crate::set_disk) async fn get_online_disks(&self) -> Vec<Option<DiskStore>> {
         let snapshot = self.drive_membership_snapshot().await;
         let mut disks = snapshot.strict_online_candidates().into_iter().map(Some).collect::<Vec<_>>();
@@ -153,6 +156,10 @@ impl SetDisks {
         disks
     }
 
+    #[allow(
+        dead_code,
+        reason = "local-only sibling of the test-covered get_online_disks; no caller in this port (backlog#1823)"
+    )]
     pub(in crate::set_disk) async fn get_online_local_disks(&self) -> Vec<Option<DiskStore>> {
         let snapshot = self.drive_membership_snapshot().await;
         let mut disks = snapshot
@@ -432,6 +439,10 @@ impl SetDisks {
         Ok((disk, fm))
     }
 
+    #[allow(
+        dead_code,
+        reason = "MinIO-parity healing-disk accessor with no caller in this port (backlog#1823)"
+    )]
     pub(in crate::set_disk) async fn get_online_disk_with_healing(
         &self,
         incl_healing: bool,
@@ -440,6 +451,10 @@ impl SetDisks {
         Ok((new_disks, healing > 0))
     }
 
+    #[allow(
+        dead_code,
+        reason = "reached only from get_online_disk_with_healing, itself uncalled in this port (backlog#1823)"
+    )]
     pub(in crate::set_disk) async fn get_online_disk_with_healing_and_info(
         &self,
         incl_healing: bool,

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

@@ -415,6 +415,7 @@ fn reduce_quorum_part_numbers(object_parts: Vec<Vec<String>>, read_quorum: usize
 /// never returned, but flips `is_truncated` to `true` and yields a
 /// `next_upload_id_marker` pointing at the last returned upload so the caller can
 /// resume paging.
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn paginate_upload_page(remaining: &[MultipartInfo], max_uploads: usize) -> (Vec<MultipartInfo>, bool, Option<String>) {
     let is_truncated = remaining.len() > max_uploads;
     let page: Vec<MultipartInfo> = remaining.iter().take(max_uploads).cloned().collect();
@@ -557,6 +558,7 @@ impl SetDisks {
     }
 
     #[tracing::instrument(level = "debug", skip(self))]
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     pub(super) async fn check_upload_id_exists(
         &self,
         bucket: &str,
@@ -1398,7 +1400,7 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
 
         let mut count = max_parts;
 
-        for (i, part) in object_parts.iter().enumerate() {
+        for part in object_parts.iter() {
             if let Some(err) = &part.error {
                 warn!("list_object_parts part error: {:?}", &err);
             }
@@ -2041,8 +2043,8 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
                     && let Err(err) = checksum.add_part(&cs, ext_part.actual_size)
                 {
                     error!(
-                        "complete_multipart_upload checksum add_part failed part_id={}, bucket={}, object={}",
-                        p.part_num, bucket, object
+                        "complete_multipart_upload checksum add_part failed part_id={}, bucket={}, object={}, err={}",
+                        p.part_num, bucket, object, err
                     );
                     return Err(Error::InvalidPart(p.part_num, ext_part.etag.clone(), p.etag.clone().unwrap_or_default()));
                 }
@@ -2087,8 +2089,8 @@ impl crate::storage_api_contracts::multipart::MultipartOperations for SetDisks {
                 }
             } else if let Err(err) = wtcs.matches(&checksum_combined, uploaded_parts.len() as i32) {
                 error!(
-                    "complete_multipart_upload checksum matches failed want={}, got={}",
-                    wtcs.encoded, checksum.encoded
+                    "complete_multipart_upload checksum matches failed want={}, got={}, err={}",
+                    wtcs.encoded, checksum.encoded, err
                 );
                 return Err(Error::other(format!(
                     "complete_multipart_upload checksum matches failed want={}, got={}",

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

@@ -3507,6 +3507,10 @@ struct TransitionUploadedSaveProbeState {
 }
 
 #[cfg(test)]
+#[allow(
+    dead_code,
+    reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+)]
 struct TransitionUploadedSaveProbe {
     state: Arc<TransitionUploadedSaveProbeState>,
 }
@@ -3517,6 +3521,10 @@ static TRANSITION_UPLOADED_SAVE_PROBE: std::sync::OnceLock<std::sync::Mutex<Opti
 
 #[cfg(test)]
 impl TransitionUploadedSaveProbe {
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     fn install(bucket: &str, object: &str) -> Self {
         let state = Arc::new(TransitionUploadedSaveProbeState {
             bucket: bucket.to_string(),
@@ -3533,6 +3541,10 @@ impl TransitionUploadedSaveProbe {
         Self { state }
     }
 
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     fn attempts(&self) -> usize {
         self.state.attempts.load(std::sync::atomic::Ordering::Acquire)
     }
@@ -3738,6 +3750,10 @@ struct TransitionCommitBarrierState {
 }
 
 #[cfg(test)]
+#[allow(
+    dead_code,
+    reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+)]
 struct TransitionCommitBarrier {
     state: Arc<TransitionCommitBarrierState>,
 }
@@ -3748,14 +3764,26 @@ static TRANSITION_COMMIT_BARRIER: std::sync::OnceLock<std::sync::Mutex<Option<Ar
 
 #[cfg(test)]
 impl TransitionCommitBarrier {
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     fn install_before_lock_lost_check(bucket: &str, object: &str) -> Self {
         Self::install_at(bucket, object, TransitionCommitPause::BeforeLockLost)
     }
 
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     fn install(bucket: &str, object: &str) -> Self {
         Self::install_at(bucket, object, TransitionCommitPause::BeforeLeaseValidation)
     }
 
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     fn install_after_lease_check(bucket: &str, object: &str) -> Self {
         Self::install_at(bucket, object, TransitionCommitPause::AfterLeaseValidation)
     }
@@ -3778,12 +3806,20 @@ impl TransitionCommitBarrier {
         Self { state }
     }
 
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     async fn wait_until_paused(&self) {
         tokio::time::timeout(Duration::from_secs(30), self.state.arrived.notified())
             .await
             .expect("transition should reach the deterministic commit barrier");
     }
 
+    #[allow(
+        dead_code,
+        reason = "installed by set_disk tests behind `--features test-util` (backlog#1823)"
+    )]
     fn release(&self) {
         self.state.release.notify_one();
     }
@@ -5620,7 +5656,9 @@ impl crate::storage_api_contracts::object::ObjectOperations for SetDisks {
         // TODO: Lifecycle
 
         let mut version_found = true;
-        let (mut goi, write_quorum, gerr) = self.get_object_info_and_quorum(bucket, object, &opts).await;
+        // delete_object_version below derives its own majority quorum from the
+        // disk array, so the object-derived quorum here is unused.
+        let (mut goi, _write_quorum, gerr) = self.get_object_info_and_quorum(bucket, object, &opts).await;
         if let Some(err) = &gerr
             && goi.name.is_empty()
         {
@@ -6374,7 +6412,7 @@ impl crate::storage_api_contracts::object::ObjectOperations for SetDisks {
         self.record_capacity_scope_if_needed(opts.capacity_scope_token, &disks);
 
         for disk in disks.iter() {
-            if let Some(disk) = disk {
+            if disk.is_some() {
                 continue;
             }
             let _ = self
@@ -10170,6 +10208,288 @@ mod transition_upload_integrity_tests {
         assert!(backend.contains(remote_object).await, "committed remote object should remain available");
     }
 
+    /// Compresses `plaintext` with the codec the PUT path uses, so the stored
+    /// bytes round-trip through the read path's decompressor.
+    async fn compress_for_storage(plaintext: &[u8]) -> Vec<u8> {
+        let mut reader = crate::io_support::rio::compression_reader(
+            Cursor::new(plaintext.to_vec()),
+            rustfs_utils::CompressionAlgorithm::default(),
+            false,
+        );
+        let mut compressed = Vec::new();
+        reader.read_to_end(&mut compressed).await.expect("plaintext should compress");
+        assert!(compressed.len() < plaintext.len(), "test payload must actually compress");
+        compressed
+    }
+
+    /// Writes a genuinely compressed object: stored data is `compressed`, and the
+    /// metadata marks it compressed with the plaintext length as its actual size,
+    /// exactly as the app-layer compress path records it.
+    async fn write_compressed_source(
+        set_disks: &Arc<SetDisks>,
+        disk_stores: &[DiskStore],
+        bucket: &str,
+        object: &str,
+        plaintext: &[u8],
+        compressed: &[u8],
+    ) -> ObjectInfo {
+        for disk in disk_stores {
+            disk.make_volume(bucket).await.expect("bucket volume should be created");
+        }
+        let mut user_defined = HashMap::new();
+        rustfs_utils::http::insert_str(
+            &mut user_defined,
+            rustfs_utils::http::SUFFIX_COMPRESSION,
+            crate::io_support::rio::compression_metadata_value(rustfs_utils::CompressionAlgorithm::default()),
+        );
+        rustfs_utils::http::insert_str(&mut user_defined, rustfs_utils::http::SUFFIX_ACTUAL_SIZE, plaintext.len().to_string());
+        let stream = crate::io_support::rio::HashReader::from_stream(
+            Cursor::new(compressed.to_vec()),
+            compressed.len() as i64,
+            plaintext.len() as i64,
+            None,
+            None,
+            false,
+        )
+        .expect("hash reader over compressed bytes");
+        let mut reader = PutObjReader::new(stream);
+        set_disks
+            .put_object(
+                bucket,
+                object,
+                &mut reader,
+                &ObjectOptions {
+                    no_lock: true,
+                    user_defined,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("compressed object should be written")
+    }
+
+    async fn read_transitioned(
+        set_disks: &Arc<SetDisks>,
+        bucket: &str,
+        object: &str,
+        range: Option<HTTPRangeSpec>,
+        opts: &ObjectOptions,
+    ) -> (Vec<u8>, i64) {
+        let mut reader = set_disks
+            .get_object_reader(bucket, object, range, HeaderMap::new(), opts)
+            .await
+            .expect("transitioned object reader should open");
+        let published_size = reader.object_info.size;
+        let mut body = Vec::new();
+        reader
+            .stream
+            .read_to_end(&mut body)
+            .await
+            .expect("transitioned body should drain");
+        (body, published_size)
+    }
+
+    /// Transition uploads the object's STORED bytes, so a tiered read has to
+    /// apply the same transform an erasure read would. #6107 routed this path
+    /// through `ReadPlan` to stop serving an encrypted object's ciphertext;
+    /// compression rides the same plan, and nothing pinned it (backlog#1851).
+    /// Without the transform this GET returns the compressed bytes under the
+    /// compressed size — silent corruption for every client of a compressed
+    /// object that ILM has moved to a warm tier.
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn transitioned_compressed_object_get_returns_plaintext() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "transitioned-compressed-get-bucket";
+        let object = "object.txt";
+        let plaintext = b"transitioned compressed objects must decompress on read ".repeat(20_000);
+        let compressed = compress_for_storage(&plaintext).await;
+        let original = write_compressed_source(&set_disks, &disk_stores, bucket, object, &plaintext, &compressed).await;
+
+        let opts = ObjectOptions {
+            no_lock: true,
+            ..Default::default()
+        };
+        let (local_body, local_size) = read_transitioned(&set_disks, bucket, object, None, &opts).await;
+        assert_eq!(local_body, plaintext, "control: the pre-transition read must decompress");
+        assert_eq!(
+            local_size,
+            plaintext.len() as i64,
+            "control: the pre-transition read publishes the plaintext size"
+        );
+
+        let tier_name = format!("COLDTIER{}", &Uuid::new_v4().simple().to_string()[..8]).to_uppercase();
+        let backend = register_mock_tier(&runtime_sources::global_tier_config_mgr(), &tier_name).await;
+        set_disks
+            .transition_object(bucket, object, &transition_options(&original, tier_name))
+            .await
+            .expect("transition should commit");
+
+        let put_versions = backend.put_versions().await;
+        assert_eq!(put_versions.len(), 1, "transition should upload one remote candidate");
+        let remote_bytes = backend
+            .bytes(&put_versions[0].0)
+            .await
+            .expect("remote candidate should be stored");
+        assert_eq!(
+            remote_bytes, compressed,
+            "transition uploads the stored representation; the read side is what has to decode it"
+        );
+
+        let (body, published_size) = read_transitioned(&set_disks, bucket, object, None, &opts).await;
+        assert_eq!(body, plaintext, "a tiered read must return the object's content, not its stored bytes");
+        assert_eq!(
+            published_size,
+            plaintext.len() as i64,
+            "a tiered read must publish the plaintext size, not the compressed one"
+        );
+    }
+
+    /// A ranged tiered read is expressed in plaintext coordinates, so the plan
+    /// has to translate it into the remote copy's compressed extent and skip
+    /// into the decompressed stream — the same translation the erasure path does.
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn transitioned_compressed_object_range_get_returns_plaintext_slice() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "transitioned-compressed-range-bucket";
+        let object = "object.txt";
+        let plaintext = b"ranged reads of transitioned compressed objects must land in plaintext ".repeat(20_000);
+        let compressed = compress_for_storage(&plaintext).await;
+        let original = write_compressed_source(&set_disks, &disk_stores, bucket, object, &plaintext, &compressed).await;
+
+        let tier_name = format!("COLDTIER{}", &Uuid::new_v4().simple().to_string()[..8]).to_uppercase();
+        register_mock_tier(&runtime_sources::global_tier_config_mgr(), &tier_name).await;
+        set_disks
+            .transition_object(bucket, object, &transition_options(&original, tier_name))
+            .await
+            .expect("transition should commit");
+
+        let opts = ObjectOptions {
+            no_lock: true,
+            ..Default::default()
+        };
+        // Deliberately past the compressed size, so a range still measured in
+        // stored coordinates could not produce this slice.
+        let start = compressed.len() as i64 + 4096;
+        let end = start + 511;
+        let range = HTTPRangeSpec {
+            is_suffix_length: false,
+            start,
+            end,
+        };
+        let (body, published_size) = read_transitioned(&set_disks, bucket, object, Some(range), &opts).await;
+
+        let expected = &plaintext[start as usize..=end as usize];
+        assert_eq!(body, expected, "a ranged tiered read must return that plaintext slice");
+        assert_eq!(published_size, expected.len() as i64, "a ranged tiered read publishes the slice length");
+    }
+
+    /// The restore copy-back re-writes the object under its original metadata,
+    /// which still says "compressed". It therefore has to keep receiving the
+    /// STORED bytes: `restore_request_active` holds it on the plan's `Plain`
+    /// branch, and decompressing there would write plaintext under compressed
+    /// metadata.
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn restore_read_of_transitioned_compressed_object_keeps_stored_bytes() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "transitioned-compressed-restore-bucket";
+        let object = "object.txt";
+        let plaintext = b"restore copy-back must keep the stored representation intact ".repeat(20_000);
+        let compressed = compress_for_storage(&plaintext).await;
+        let original = write_compressed_source(&set_disks, &disk_stores, bucket, object, &plaintext, &compressed).await;
+
+        let tier_name = format!("COLDTIER{}", &Uuid::new_v4().simple().to_string()[..8]).to_uppercase();
+        register_mock_tier(&runtime_sources::global_tier_config_mgr(), &tier_name).await;
+        set_disks
+            .transition_object(bucket, object, &transition_options(&original, tier_name))
+            .await
+            .expect("transition should commit");
+
+        let oi = set_disks
+            .get_object_info(
+                bucket,
+                object,
+                &ObjectOptions {
+                    no_lock: true,
+                    ..Default::default()
+                },
+            )
+            .await
+            .expect("transitioned metadata should resolve");
+        let restore_opts = ObjectOptions {
+            no_lock: true,
+            part_number: Some(1),
+            transition: TransitionOptions {
+                restore_request: s3s::dto::RestoreRequest {
+                    days: Some(1),
+                    ..Default::default()
+                },
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+        let mut reader = get_transitioned_object_reader_with_tier_manager(
+            bucket,
+            object,
+            &None,
+            &HeaderMap::new(),
+            &oi,
+            &restore_opts,
+            &set_disks.ctx.tier_config_mgr(),
+            set_disks.ctx.object_encryption_resolver(),
+        )
+        .await
+        .expect("restore read of the tiered copy should open");
+        let published_size = reader.object_info.size;
+        let mut body = Vec::new();
+        reader.stream.read_to_end(&mut body).await.expect("restore body should drain");
+
+        assert_eq!(body, compressed, "a restore read must copy the stored bytes back verbatim");
+        assert_eq!(
+            published_size,
+            compressed.len() as i64,
+            "a restore read must keep publishing the stored size"
+        );
+    }
+
+    /// Plain objects must keep streaming the remote bytes through untouched:
+    /// their plan is `Plain`, so the tiered read stays byte-identical.
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn transitioned_plain_object_get_is_unchanged() {
+        let (_temp_dirs, disk_stores, set_disks) = hermetic_set_disks(4).await;
+        let bucket = "transitioned-plain-get-bucket";
+        let object = "object.bin";
+        let payload = b"plain transitioned objects must keep reading back byte-identical ".repeat(1024);
+        let original = write_source(&set_disks, &disk_stores, bucket, object, &payload).await;
+
+        let tier_name = format!("COLDTIER{}", &Uuid::new_v4().simple().to_string()[..8]).to_uppercase();
+        register_mock_tier(&runtime_sources::global_tier_config_mgr(), &tier_name).await;
+        set_disks
+            .transition_object(bucket, object, &transition_options(&original, tier_name))
+            .await
+            .expect("transition should commit");
+
+        let opts = ObjectOptions {
+            no_lock: true,
+            ..Default::default()
+        };
+        let (body, published_size) = read_transitioned(&set_disks, bucket, object, None, &opts).await;
+        assert_eq!(body, payload);
+        assert_eq!(published_size, payload.len() as i64);
+
+        let range = HTTPRangeSpec {
+            is_suffix_length: false,
+            start: 100,
+            end: 611,
+        };
+        let (ranged_body, ranged_size) = read_transitioned(&set_disks, bucket, object, Some(range), &opts).await;
+        assert_eq!(ranged_body, &payload[100..=611]);
+        assert_eq!(ranged_size, payload.len() as i64, "a plain ranged read keeps publishing the object size");
+    }
+
     async fn corrupt_beyond_read_quorum(
         temp_dirs: &[tempfile::TempDir],
         bucket: &str,

crates/ecstore/src/set_disk/read.rs

@@ -116,6 +116,7 @@ impl SetDisks {
             .then_some(GET_METADATA_CACHE_REASON_DIST_ERASURE)
     }
 
+    #[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
     async fn cached_get_object_fileinfo(&self, bucket: &str, object: &str) -> Option<Arc<GetObjectMetadataCacheEntry>> {
         match self.lookup_cached_get_object_fileinfo(bucket, object).await {
             MetadataCacheLookup::Hit(entry) => Some(entry),
@@ -1826,6 +1827,7 @@ fn get_object_metadata_cache_request_bypass_reason(bucket: &str, opts: &ObjectOp
         .then_some(GET_METADATA_CACHE_REASON_META_BUCKET)
 }
 
+#[allow(dead_code, reason = "asserted by this file's tests (backlog#1823)")]
 fn is_get_object_metadata_cache_request_eligible(bucket: &str, opts: &ObjectOptions, read_data: bool) -> bool {
     get_object_metadata_cache_request_bypass_reason(bucket, opts, read_data).is_none()
 }
@@ -3935,7 +3937,7 @@ mod tests {
     }
 
     #[test]
-    fn metadata_early_stop_bounded_fanout_defaults_to_disabled() {
+    fn metadata_early_stop_bounded_fanout_defaults_to_enabled() {
         temp_env::with_vars(
             [
                 (ENV_RUSTFS_GET_METADATA_EARLY_STOP_ENABLE, Some("true")),
@@ -3944,20 +3946,20 @@ mod tests {
             ],
             || {
                 assert!(is_get_metadata_data_read_early_stop_enabled());
-                assert!(!is_get_metadata_early_stop_bounded_fanout_enabled());
+                assert!(is_get_metadata_early_stop_bounded_fanout_enabled());
             },
         );
-        temp_env::with_vars([(ENV_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT, Some("true"))], || {
-            assert!(is_get_metadata_early_stop_bounded_fanout_enabled());
+        temp_env::with_vars([(ENV_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT, Some("false"))], || {
+            assert!(!is_get_metadata_early_stop_bounded_fanout_enabled());
         });
         temp_env::with_vars(
             [
                 (ENV_RUSTFS_GET_METADATA_DATA_READ_EARLY_STOP_ENABLE, Some("false")),
-                (ENV_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT, Some("false")),
+                (ENV_RUSTFS_GET_METADATA_EARLY_STOP_BOUNDED_FANOUT, Some("true")),
             ],
             || {
                 assert!(!is_get_metadata_data_read_early_stop_enabled());
-                assert!(!is_get_metadata_early_stop_bounded_fanout_enabled());
+                assert!(is_get_metadata_early_stop_bounded_fanout_enabled());
             },
         );
     }

crates/io-metrics/src/lib.rs

@@ -487,22 +487,21 @@ pub fn record_get_object_completion(total_duration_secs: f64, response_size_byte
 
 /// Record the streaming strategy chosen for a GetObject response body.
 #[inline(always)]
-pub fn record_get_object_stream_strategy(strategy: &str, buffer_size_bytes: usize, response_size_bytes: i64) {
+pub fn record_get_object_stream_strategy(strategy: &'static str, buffer_size_bytes: usize, response_size_bytes: i64) {
     if !get_stage_metrics_enabled() {
         return;
     }
-    counter!("rustfs_io_get_object_stream_strategy_total", "strategy" => strategy.to_string()).increment(1);
-    histogram!("rustfs_io_get_object_stream_buffer_size_bytes", "strategy" => strategy.to_string())
-        .record(usize_to_f64(buffer_size_bytes));
-    histogram!("rustfs_io_get_object_stream_response_size_bytes", "strategy" => strategy.to_string())
+    counter!("rustfs_io_get_object_stream_strategy_total", "strategy" => strategy).increment(1);
+    histogram!("rustfs_io_get_object_stream_buffer_size_bytes", "strategy" => strategy).record(usize_to_f64(buffer_size_bytes));
+    histogram!("rustfs_io_get_object_stream_response_size_bytes", "strategy" => strategy)
         .record(i64_non_negative_to_f64(response_size_bytes));
 }
 
 /// Record the response-body handoff shape from a GetObject reader into the S3 streaming body.
 #[inline(always)]
 pub fn record_get_object_response_handoff(
-    strategy: &str,
-    buffer_source: &str,
+    strategy: &'static str,
+    buffer_source: &'static str,
     buffer_size_bytes: usize,
     response_size_bytes: i64,
     duration_secs: f64,
@@ -512,26 +511,26 @@ pub fn record_get_object_response_handoff(
     }
     counter!(
         "rustfs_io_get_object_response_handoff_total",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string()
+        "strategy" => strategy,
+        "buffer_source" => buffer_source
     )
     .increment(1);
     histogram!(
         "rustfs_io_get_object_response_handoff_buffer_size_bytes",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string()
+        "strategy" => strategy,
+        "buffer_source" => buffer_source
     )
     .record(usize_to_f64(buffer_size_bytes));
     histogram!(
         "rustfs_io_get_object_response_handoff_response_size_bytes",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string()
+        "strategy" => strategy,
+        "buffer_source" => buffer_source
     )
     .record(i64_non_negative_to_f64(response_size_bytes));
     histogram!(
         "rustfs_io_get_object_response_handoff_duration_seconds",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string()
+        "strategy" => strategy,
+        "buffer_source" => buffer_source
     )
     .record(duration_secs);
     record_get_object_response_handoff_duration("s3_handler", duration_secs);
@@ -539,14 +538,18 @@ pub fn record_get_object_response_handoff(
 
 /// Record ReaderStream capacity chosen for GetObject handoff.
 #[inline(always)]
-pub fn record_get_object_reader_stream_buffer_size(strategy: &str, buffer_source: &str, buffer_size_bytes: usize) {
+pub fn record_get_object_reader_stream_buffer_size(
+    strategy: &'static str,
+    buffer_source: &'static str,
+    buffer_size_bytes: usize,
+) {
     if !get_stage_metrics_enabled() {
         return;
     }
     histogram!(
         "rustfs_io_get_object_reader_stream_buffer_size_bytes",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string()
+        "strategy" => strategy,
+        "buffer_source" => buffer_source
     )
     .record(usize_to_f64(buffer_size_bytes));
 }
@@ -554,8 +557,8 @@ pub fn record_get_object_reader_stream_buffer_size(strategy: &str, buffer_source
 /// Record ReaderStream poll outcomes for GetObject handoff attribution.
 #[inline(always)]
 pub fn record_get_object_reader_stream_poll(
-    strategy: &str,
-    buffer_source: &str,
+    strategy: &'static str,
+    buffer_source: &'static str,
     outcome: &'static str,
     remaining_before: usize,
     bytes: usize,
@@ -567,36 +570,36 @@ pub fn record_get_object_reader_stream_poll(
     let bytes = u64::try_from(bytes).unwrap_or(u64::MAX);
     counter!(
         "rustfs_io_get_object_reader_stream_poll_total",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string(),
+        "strategy" => strategy,
+        "buffer_source" => buffer_source,
         "outcome" => outcome
     )
     .increment(1);
     counter!(
         "rustfs_io_get_object_reader_stream_poll_bytes_total",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string(),
+        "strategy" => strategy,
+        "buffer_source" => buffer_source,
         "outcome" => outcome
     )
     .increment(bytes);
     histogram!(
         "rustfs_io_get_object_reader_stream_poll_remaining_bytes",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string(),
+        "strategy" => strategy,
+        "buffer_source" => buffer_source,
         "outcome" => outcome
     )
     .record(usize_to_f64(remaining_before));
     histogram!(
         "rustfs_io_get_object_reader_stream_poll_bytes",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string(),
+        "strategy" => strategy,
+        "buffer_source" => buffer_source,
         "outcome" => outcome
     )
     .record(usize_to_f64(bytes as usize));
     histogram!(
         "rustfs_io_get_object_reader_stream_poll_duration_seconds",
-        "strategy" => strategy.to_string(),
-        "buffer_source" => buffer_source.to_string(),
+        "strategy" => strategy,
+        "buffer_source" => buffer_source,
         "outcome" => outcome
     )
     .record(duration_secs);

crates/keystone/src/client.rs

@@ -31,7 +31,10 @@ pub struct KeystoneClient {
     admin_password: Option<String>,
     admin_project: Option<String>,
     admin_domain: String,
-    #[allow(dead_code)]
+    #[allow(
+        dead_code,
+        reason = "TLS verification flag parsed from config; the reqwest client is built before it is consulted, so nothing reads it back (backlog#1823)"
+    )]
     verify_ssl: bool,
     /// Request timeout applied to the underlying HTTP client.
     timeout: std::time::Duration,

crates/keystone/src/identity.rs

@@ -20,7 +20,10 @@ use tracing::{debug, info};
 
 /// Maps Keystone identities to RustFS concepts
 pub struct KeystoneIdentityMapper {
-    #[allow(dead_code)]
+    #[allow(
+        dead_code,
+        reason = "keeps the Keystone client alive for the mapper's lifetime; the mapping paths do not call through it yet (backlog#1823)"
+    )]
     client: Arc<KeystoneClient>,
     role_policy_map: HashMap<String, String>,
     enable_tenant_prefix: bool,

crates/kms/src/encryption/dek.rs

@@ -18,8 +18,6 @@
 //! data encryption keys using master keys. It abstracts the encryption
 //! operations so that different backends can share the same encryption logic.
 
-#![allow(dead_code)] // Trait methods may be used by implementations
-
 use crate::error::{KmsError, Result};
 use crate::persisted_observability::{BoundedUnknownFieldName, UnknownFieldSummary};
 use async_trait::async_trait;

crates/notify/src/rules/config.rs

@@ -40,7 +40,10 @@ impl RuleEvents for RuleView {
 #[derive(Debug)]
 struct CompiledRules {
     // Keep RulesMap (can be used later if you want to make more complex judgments during the snapshot reading phase)
-    #[allow(dead_code)]
+    #[allow(
+        dead_code,
+        reason = "speculative retention: the comment above keeps it for richer snapshot-time judgements that no code performs yet (backlog#1823)"
+    )]
     rules_map: RulesMap,
     // for RulesContainer::iter_rules
     rule_views: Vec<RuleView>,

crates/notify/src/rules/rules_map.rs

@@ -187,7 +187,6 @@ impl RulesMap {
     /// # Parameters
     /// * `event_name` - The EventName from which to remove the rule.
     /// * `pattern` - The pattern of the rule to be removed.
-    #[allow(dead_code)]
     pub fn remove_rule(&mut self, event_name: &EventName, pattern: &str) {
         let mut remove_event = false;
 
@@ -209,7 +208,6 @@ impl RulesMap {
     ///
     /// # Parameters
     /// * `event_names` - A slice of EventNames to be removed.
-    #[allow(dead_code)]
     pub fn remove_rules(&mut self, event_names: &[EventName]) {
         for event_name in event_names {
             self.map.remove(event_name);
@@ -223,7 +221,6 @@ impl RulesMap {
     /// * `event_name` - The EventName to update.
     /// * `pattern` - The pattern of the rule to be updated.
     /// * `target_id` - The TargetID to be added.
-    #[allow(dead_code)]
     pub fn update_rule(&mut self, event_name: EventName, pattern: String, target_id: TargetID) {
         self.map.entry(event_name).or_default().add(pattern, target_id);
         self.total_events_mask |= event_name.mask(); // Update only the relevant bitmask

crates/notify/src/rules/target_id_set.rs

@@ -18,12 +18,6 @@ use rustfs_targets::arn::TargetID;
 /// TargetIDSet - A collection representation of TargetID.
 pub type TargetIdSet = HashSet<TargetID>;
 
-/// Provides a Go-like method for TargetIdSet (can be implemented as trait if needed)
-#[allow(dead_code)]
-pub(crate) fn new_target_id_set(target_ids: Vec<TargetID>) -> TargetIdSet {
-    target_ids.into_iter().collect()
-}
-
 // HashSet has built-in clone, union, difference and other operations.
 // But the Go version of the method returns a new Set, and the HashSet method is usually iterator or modify itself.
 // If you need to exactly match Go's API style, you can add wrapper functions.

crates/obs/src/metrics/config.rs

@@ -17,7 +17,6 @@ use std::time::Duration;
 /// Environment variable key for the global default metrics interval (seconds).
 pub const ENV_DEFAULT_METRICS_INTERVAL: &str = "RUSTFS_METRICS_DEFAULT_INTERVAL_SEC";
 /// Default interval for metrics collection if not specified otherwise.
-#[allow(dead_code)]
 pub const DEFAULT_METRICS_INTERVAL: Duration = Duration::from_secs(60);
 
 /// Environment variable key for cluster metrics interval (seconds).

crates/obs/src/metrics/report.rs

@@ -145,21 +145,18 @@ impl PrometheusMetric {
     }
 
     #[inline]
-    #[allow(dead_code)]
     pub fn with_label(mut self, key: &'static str, value: impl Into<Cow<'static, str>>) -> Self {
         self.labels.push((key, value.into()));
         self
     }
 
     #[inline]
-    #[allow(dead_code)]
     pub fn with_label_owned(mut self, key: &'static str, value: String) -> Self {
         self.labels.push((key, Cow::Owned(value)));
         self
     }
 
     #[inline]
-    #[allow(dead_code)]
     pub fn with_labels(mut self, labels: Vec<(&'static str, Cow<'static, str>)>) -> Self {
         self.labels = labels;
         self

crates/obs/src/metrics/schema/entry/descriptor.rs

@@ -16,7 +16,6 @@ use crate::{MetricName, MetricNamespace, MetricSubsystem, MetricType};
 use std::collections::HashSet;
 
 /// MetricDescriptor - Metric descriptors
-#[allow(dead_code)]
 #[derive(Debug, Clone)]
 pub struct MetricDescriptor {
     pub name: MetricName,
@@ -52,7 +51,6 @@ impl MetricDescriptor {
     }
 
     /// Get the full metric name in Prometheus style: <namespace>_<subsystem>_<name>
-    #[allow(dead_code)]
     pub fn get_full_metric_name(&self) -> String {
         let namespace = self.namespace.as_str();
         let formatted_subsystem = self.subsystem.as_str();
@@ -61,7 +59,6 @@ impl MetricDescriptor {
     }
 
     /// check whether the label is in the label set
-    #[allow(dead_code)]
     pub fn has_label(&mut self, label: &str) -> bool {
         self.get_label_set().contains(label)
     }

crates/obs/src/metrics/schema/entry/metric_name.rs

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 /// The metric name is the individual name of the metric
-#[allow(dead_code)]
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum MetricName {
     // The generic metric name
@@ -443,7 +442,6 @@ pub enum MetricName {
 }
 
 impl MetricName {
-    #[allow(dead_code)]
     pub fn as_str(&self) -> String {
         match self {
             Self::AuthTotal => "auth_total".to_string(),

crates/obs/src/metrics/schema/entry/metric_type.rs

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 /// MetricType - Indicates the type of indicator
-#[allow(dead_code)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum MetricType {
     Counter,
@@ -23,7 +22,6 @@ pub enum MetricType {
 
 impl MetricType {
     /// convert the metric type to a string representation
-    #[allow(dead_code)]
     pub fn as_str(&self) -> &'static str {
         match self {
             Self::Counter => "counter",
@@ -34,7 +32,6 @@ impl MetricType {
 
     /// Convert the metric type to the Prometheus value type
     /// In a Rust implementation, this might return the corresponding Prometheus Rust client type
-    #[allow(dead_code)]
     pub fn as_prom(&self) -> &'static str {
         match self {
             Self::Counter => "counter.",

crates/obs/src/metrics/schema/entry/mod.rs

@@ -56,7 +56,6 @@ pub fn new_gauge_md(
 }
 
 /// create a new histogram indicator descriptor
-#[allow(dead_code)]
 pub fn new_histogram_md(
     name: impl Into<MetricName>,
     help: impl Into<String>,

crates/obs/src/metrics/schema/entry/namespace.rs

@@ -19,7 +19,6 @@ pub enum MetricNamespace {
 }
 
 impl MetricNamespace {
-    #[allow(dead_code)]
     pub fn as_str(&self) -> &'static str {
         match self {
             Self::RustFS => "rustfs",

crates/obs/src/metrics/schema/entry/path_utils.rs

@@ -14,7 +14,6 @@
 
 /// Format the path to the metric name format
 /// Replace '/' and '-' with '_'
-#[allow(dead_code)]
 pub fn format_path_to_metric_name(path: &str) -> String {
     path.trim_start_matches('/').replace(['/', '-'], "_")
 }

crates/obs/src/metrics/schema/entry/subsystem.rs

@@ -102,7 +102,6 @@ impl MetricSubsystem {
     }
 
     /// Get the formatted metric name format string
-    #[allow(dead_code)]
     pub fn as_str(&self) -> String {
         format_path_to_metric_name(self.path())
     }
@@ -151,7 +150,6 @@ impl MetricSubsystem {
     }
 
     /// A convenient way to create custom subsystems directly
-    #[allow(dead_code)]
     pub fn new(path: impl Into<String>) -> Self {
         Self::Custom(path.into())
     }
@@ -176,7 +174,6 @@ impl std::fmt::Display for MetricSubsystem {
     }
 }
 
-#[allow(dead_code)]
 pub mod subsystems {
     use super::MetricSubsystem;
 

crates/obs/src/telemetry/rolling.rs

@@ -38,7 +38,10 @@ pub enum Rotation {
     Minutely,
     Hourly,
     Daily,
-    #[allow(dead_code)]
+    #[allow(
+        dead_code,
+        reason = "constructed only by this file's rolling-appender tests; the lib target cannot see them (backlog#1823)"
+    )]
     Never,
 }
 

crates/policy/src/policy/function.rs

@@ -219,10 +219,6 @@ impl PartialEq for Functions {
     }
 }
 
-#[derive(Clone, Serialize, Deserialize)]
-#[allow(dead_code)]
-pub struct Value;
-
 #[cfg(test)]
 mod tests {
     use crate::policy::Functions;

crates/policy/src/policy/utils/wildcard.rs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#[allow(dead_code)]
 pub fn is_simple_match<P, N>(pattern: P, name: N) -> bool
 where
     P: AsRef<str>,
@@ -29,7 +28,10 @@ where
     inner_match(pattern, name, false)
 }
 
-#[allow(dead_code)]
+#[allow(
+    dead_code,
+    reason = "prefix-matcher asserted by this file's tests; no production caller yet (backlog#1823)"
+)]
 pub fn is_match_as_pattern_prefix<P, N>(pattern: P, text: N) -> bool
 where
     P: AsRef<str>,

crates/protocols/src/swift/account.rs

@@ -38,7 +38,6 @@ use std::collections::HashMap;
 /// - Account format is invalid
 /// - Credentials don't contain project_id
 /// - Account project_id doesn't match credentials project_id
-#[allow(dead_code)] // Used by Swift implementation
 pub fn validate_account_access(account: &str, credentials: &Credentials) -> SwiftResult<String> {
     // Extract project_id from account (strip "AUTH_" prefix)
     let account_project_id = account
@@ -70,7 +69,6 @@ pub fn validate_account_access(account: &str, credentials: &Credentials) -> Swif
 ///
 /// Admin users (with "admin" or "reseller_admin" roles) can perform
 /// cross-tenant operations and administrative tasks.
-#[allow(dead_code)] // Used by Swift implementation
 pub fn is_admin_user(credentials: &Credentials) -> bool {
     credentials
         .claims

crates/protocols/src/swift/container.rs

@@ -144,7 +144,6 @@ impl ContainerMapper {
     /// - S3 bucket name compatible (only uses [a-z0-9-])
     /// - Deterministic mapping (same input always produces same bucket name)
     /// - Fixed-length prefix (16 hex chars = 8 bytes)
-    #[allow(dead_code)] // Used in: create/delete container operations
     pub fn swift_to_s3_bucket(&self, container: &str, project_id: &str) -> String {
         if self.config.tenant_prefix_enabled {
             let hash = self.hash_project_id(project_id);
@@ -216,7 +215,6 @@ pub fn bucket_info_to_container(info: &BucketInfo, mapper: &ContainerMapper, pro
 /// 2. Lists all S3 buckets
 /// 3. Filters to buckets belonging to this tenant (using tenant prefix)
 /// 4. Converts BucketInfo to Swift Container format
-#[allow(dead_code)] // Used by handler: list containers
 pub async fn list_containers(account: &str, credentials: &Credentials) -> SwiftResult<Vec<Container>> {
     // Validate account access and extract project_id
     let project_id = validate_account_access(account, credentials)?;
@@ -279,7 +277,6 @@ pub async fn list_containers(account: &str, credentials: &Credentials) -> SwiftR
 /// - Returns 201 Created on success
 /// - Returns 202 Accepted if container already exists
 /// - Returns 400 Bad Request for invalid container names
-#[allow(dead_code)] // Used by handler
 pub async fn create_container(account: &str, container: &str, credentials: &Credentials) -> SwiftResult<bool> {
     // Validate account access and extract project_id
     let project_id = validate_account_access(account, credentials)?;
@@ -348,7 +345,6 @@ fn validate_container_name(container: &str) -> SwiftResult<()> {
 }
 
 /// Container metadata for HEAD response
-#[allow(dead_code)] // TODO: Remove once Swift API integration is complete
 #[derive(Debug, Clone)]
 pub struct ContainerMetadata {
     /// Number of objects in container
@@ -411,7 +407,6 @@ pub(crate) async fn get_container_custom_metadata(
 /// - HEAD /v1/{account}/{container} returns container metadata
 /// - Returns 204 No Content on success with headers
 /// - Returns 404 Not Found if container doesn't exist
-#[allow(dead_code)] // Used by handler
 pub async fn get_container_metadata(account: &str, container: &str, credentials: &Credentials) -> SwiftResult<ContainerMetadata> {
     let (bucket_name, bucket_info, custom_metadata) = get_container_metadata_base(account, container, credentials).await?;
 
@@ -448,7 +443,6 @@ pub async fn get_container_metadata(account: &str, container: &str, credentials:
 /// - The update is additive: items the request does not name keep their stored
 ///   value, and removal is explicit, via `X-Remove-Container-Meta-{name}` or an
 ///   empty value
-#[allow(dead_code)] // Used by handler
 pub async fn update_container_metadata(
     account: &str,
     container: &str,
@@ -520,7 +514,6 @@ pub async fn update_container_metadata(
 /// - Returns 204 No Content on success
 /// - Returns 404 Not Found if container doesn't exist
 /// - Returns 409 Conflict if container is not empty
-#[allow(dead_code)] // Used by handler
 pub async fn delete_container(account: &str, container: &str, credentials: &Credentials) -> SwiftResult<()> {
     // Validate account access and extract project_id
     let project_id = validate_account_access(account, credentials)?;
@@ -603,7 +596,6 @@ pub async fn delete_container(account: &str, container: &str, credentials: &Cred
 /// - Account validation fails
 /// - Container doesn't exist
 /// - Storage layer errors occur
-#[allow(dead_code)] // Handler integration: GET container
 pub async fn list_objects(
     account: &str,
     container: &str,
@@ -706,7 +698,6 @@ pub async fn list_objects(
 /// Versioning configuration is stored as an S3 bucket tag:
 /// - Tag key: `swift-versions-location`
 /// - Tag value: archive container name
-#[allow(dead_code)] // Used by handler
 pub async fn enable_versioning(
     account: &str,
     container: &str,
@@ -795,7 +786,6 @@ pub async fn enable_versioning(
 /// * `account` - Account identifier
 /// * `container` - Container name to disable versioning on
 /// * `credentials` - Keystone credentials
-#[allow(dead_code)] // Used by handler
 pub async fn disable_versioning(account: &str, container: &str, credentials: &Credentials) -> SwiftResult<()> {
     // Validate account access
     let project_id = validate_account_access(account, credentials)?;
@@ -855,7 +845,6 @@ pub async fn disable_versioning(account: &str, container: &str, credentials: &Cr
 /// # Returns
 /// - Some(archive_container_name) if versioning is enabled
 /// - None if versioning is not enabled
-#[allow(dead_code)] // Used by handler and object.rs
 pub async fn get_versions_location(account: &str, container: &str, credentials: &Credentials) -> SwiftResult<Option<String>> {
     // Validate account access
     let project_id = validate_account_access(account, credentials)?;
@@ -918,7 +907,6 @@ pub async fn get_versions_location(account: &str, container: &str, credentials:
 ///     &credentials
 /// ).await?;
 /// ```
-#[allow(dead_code)] // Used by handler
 pub async fn set_container_acl(
     account: &str,
     container: &str,
@@ -1022,7 +1010,6 @@ pub async fn set_container_acl(
 ///     println!("Container is publicly readable");
 /// }
 /// ```
-#[allow(dead_code)] // Used by handler
 pub async fn get_container_acl(
     account: &str,
     container: &str,
@@ -1083,7 +1070,6 @@ pub async fn get_container_acl(
 ///
 /// # Returns
 /// Ok(()) if ACLs were deleted successfully
-#[allow(dead_code)] // Used by handler
 pub async fn delete_container_acl(account: &str, container: &str, credentials: &Credentials) -> SwiftResult<()> {
     // Setting both ACLs to None removes them
     set_container_acl(account, container, None, None, credentials).await

crates/protocols/src/swift/errors.rs

@@ -20,7 +20,6 @@ use std::fmt;
 
 /// Swift-specific error type
 #[derive(Debug)]
-#[allow(dead_code)] // Error variants used by Swift implementation
 pub enum SwiftError {
     /// 400 Bad Request
     BadRequest(String),

crates/protocols/src/swift/object.rs

@@ -122,12 +122,10 @@ fn swift_user_metadata(headers: &HeaderMap) -> Option<HashMap<String, String>> {
 ///
 /// Handles URL encoding/decoding and path normalization for Swift object keys.
 /// Swift object names can contain any UTF-8 characters except null bytes.
-#[allow(dead_code)] // Used in: object operations
 pub struct ObjectKeyMapper;
 
 impl ObjectKeyMapper {
     /// Create a new object key mapper
-    #[allow(dead_code)] // Used in: object operations
     pub fn new() -> Self {
         Self
     }
@@ -140,7 +138,6 @@ impl ObjectKeyMapper {
     /// - Not contain null bytes
     /// - Not contain '..' path segments (directory traversal)
     /// - Not start with '/' (leading slash handled by routing)
-    #[allow(dead_code)] // Used in: object operations
     pub fn validate_object_name(object: &str) -> SwiftResult<()> {
         if object.is_empty() {
             return Err(SwiftError::BadRequest("Object name cannot be empty".to_string()));
@@ -183,7 +180,6 @@ impl ObjectKeyMapper {
     /// Example:
     /// - Swift: "photos/vacation/beach photo.jpg"
     /// - S3: "photos/vacation/beach photo.jpg"
-    #[allow(dead_code)] // Used in: object operations
     pub fn swift_to_s3_key(object: &str) -> SwiftResult<String> {
         Self::validate_object_name(object)?;
         Ok(object.to_string())
@@ -193,7 +189,6 @@ impl ObjectKeyMapper {
     ///
     /// This is essentially an identity transformation since we store
     /// Swift object names as-is in S3.
-    #[allow(dead_code)] // Used in: object operations
     pub fn s3_to_swift_name(key: &str) -> String {
         key.to_string()
     }
@@ -208,7 +203,6 @@ impl ObjectKeyMapper {
     /// - Object: "vacation/beach.jpg"
     /// - Bucket: "abc123:photos"
     /// - Key: "vacation/beach.jpg"
-    #[allow(dead_code)] // Used in: object operations
     pub fn build_s3_key(object: &str) -> SwiftResult<String> {
         Self::swift_to_s3_key(object)
     }
@@ -220,7 +214,6 @@ impl ObjectKeyMapper {
     ///
     /// Example URL: /v1/AUTH_abc/container/path%2Fto%2Ffile.txt
     /// Decoded: "path/to/file.txt"
-    #[allow(dead_code)] // Used in: object operations
     pub fn decode_object_from_url(encoded: &str) -> SwiftResult<String> {
         // Decode percent-encoding
         let decoded = urlencoding::decode(encoded).map_err(|e| SwiftError::BadRequest(format!("Invalid URL encoding: {}", e)))?;
@@ -233,7 +226,6 @@ impl ObjectKeyMapper {
     ///
     /// When constructing URLs (e.g., for redirect responses), we need to
     /// percent-encode object names.
-    #[allow(dead_code)] // Used in: object operations
     pub fn encode_object_for_url(object: &str) -> String {
         urlencoding::encode(object).to_string()
     }
@@ -241,7 +233,6 @@ impl ObjectKeyMapper {
     /// Check if object name represents a directory (pseudo-directory)
     ///
     /// In Swift, objects ending with '/' are treated as directory markers.
-    #[allow(dead_code)] // Used in: object operations
     pub fn is_directory_marker(object: &str) -> bool {
         object.ends_with('/')
     }
@@ -250,7 +241,6 @@ impl ObjectKeyMapper {
     ///
     /// Removes redundant slashes and normalizes the path while preserving
     /// trailing slashes for directory markers.
-    #[allow(dead_code)] // Used in: object operations
     pub fn normalize_path(object: &str) -> String {
         // Split by '/', filter out empty segments (except if it's the end)
         let has_trailing_slash = object.ends_with('/');
@@ -324,7 +314,6 @@ fn sanitize_storage_error<E: std::fmt::Display>(operation: &str, error: E) -> Sw
 /// # Returns
 /// * `Ok(etag)` - Object ETag on success
 /// * `Err(SwiftError)` - Error if validation fails or upload fails
-#[allow(dead_code)] // Handler integration: PUT object
 pub async fn put_object<R>(
     account: &str,
     container: &str,
@@ -445,7 +434,6 @@ where
 ///
 /// Similar to put_object, but allows directly specifying metadata instead of extracting from headers.
 /// This is used internally for storing SLO manifests and marker objects.
-#[allow(dead_code)] // Used by SLO implementation
 pub async fn put_object_with_metadata<R>(
     account: &str,
     container: &str,
@@ -549,7 +537,6 @@ where
 /// - `bytes=1000-1999` - Bytes 1000-1999
 /// - `bytes=1000-` - From byte 1000 to end
 /// - `bytes=-500` - Last 500 bytes
-#[allow(dead_code)] // Handler integration: GET object
 pub async fn get_object(
     account: &str,
     container: &str,
@@ -608,7 +595,6 @@ pub async fn get_object(
 /// # Returns
 /// * `Ok(object_info)` - Object metadata (ObjectInfo)
 /// * `Err(SwiftError)` - Error if validation fails or object not found
-#[allow(dead_code)] // Handler integration: HEAD object
 pub async fn head_object(
     account: &str,
     container: &str,
@@ -671,7 +657,6 @@ pub async fn head_object(
 /// # Returns
 /// * `Ok(())` - Object deleted successfully (or didn't exist)
 /// * `Err(SwiftError)` - Error if validation fails or deletion fails
-#[allow(dead_code)] // Handler integration: DELETE object
 pub async fn delete_object(account: &str, container: &str, object: &str, credentials: &Credentials) -> SwiftResult<()> {
     // 1. Validate account access and get project_id
     let project_id = validate_account_access(account, credentials)?;
@@ -732,7 +717,6 @@ pub async fn delete_object(account: &str, container: &str, object: &str, credent
 /// # Returns
 /// * `Ok(())` - Metadata updated successfully
 /// * `Err(SwiftError)` - Error if validation fails, object not found, or update fails
-#[allow(dead_code)] // Handler integration: POST object
 pub async fn update_object_metadata(
     account: &str,
     container: &str,
@@ -846,7 +830,6 @@ pub async fn update_object_metadata(
 /// # Handler Integration Note
 /// The current handler architecture needs to be updated to pass headers through
 /// to support COPY method and X-Copy-From header detection. See handler.rs for details.
-#[allow(dead_code)] // Handler integration: COPY object
 #[allow(clippy::too_many_arguments)] // Necessary for full copy functionality
 pub async fn copy_object(
     src_account: &str,
@@ -979,7 +962,6 @@ pub async fn copy_object(
 /// assert_eq!(container, "my-container");
 /// assert_eq!(object, "path/to/file.txt");
 /// ```
-#[allow(dead_code)] // Handler integration: COPY method
 pub fn parse_destination_header(destination: &str) -> SwiftResult<(String, String)> {
     let destination = destination.trim_start_matches('/');
     let parts: Vec<&str> = destination.splitn(2, '/').collect();
@@ -1013,7 +995,6 @@ pub fn parse_destination_header(destination: &str) -> SwiftResult<(String, Strin
 /// # Returns
 /// * `Ok((container, object))` - Parsed container and object names
 /// * `Err(SwiftError)` - Error if format is invalid
-#[allow(dead_code)] // Handler integration: X-Copy-From
 pub fn parse_copy_from_header(copy_from: &str) -> SwiftResult<(String, String)> {
     // Same parsing logic as Destination header
     parse_destination_header(copy_from)
@@ -1042,7 +1023,6 @@ pub fn parse_copy_from_header(copy_from: &str) -> SwiftResult<(String, String)>
 /// assert_eq!(range.start, 0);
 /// assert_eq!(range.end, 1023);
 /// ```
-#[allow(dead_code)] // Handler integration: Range header
 pub fn parse_range_header(range_str: &str) -> SwiftResult<HTTPRangeSpec> {
     if !range_str.starts_with("bytes=") {
         return Err(SwiftError::BadRequest("Range header must start with 'bytes='".to_string()));
@@ -1124,7 +1104,6 @@ pub fn parse_range_header(range_str: &str) -> SwiftResult<HTTPRangeSpec> {
 /// let header = format_content_range(0, 1023, 5000);
 /// assert_eq!(header, "bytes 0-1023/5000");
 /// ```
-#[allow(dead_code)] // Handler integration: Range header
 pub fn format_content_range(start: i64, end: i64, total: i64) -> String {
     format!("bytes {}-{}/{}", start, end, total)
 }

crates/protocols/src/swift/router.rs

@@ -50,7 +50,6 @@ pub enum SwiftRoute {
 
 impl SwiftRoute {
     /// Get the account identifier from the route
-    #[allow(dead_code)] // Public API for future use
     pub fn account(&self) -> &str {
         match self {
             SwiftRoute::Account { account, .. } => account,
@@ -60,7 +59,6 @@ impl SwiftRoute {
     }
 
     /// Extract project_id from account string (removes AUTH_ prefix)
-    #[allow(dead_code)] // Public API for future use
     pub fn project_id(&self) -> Option<&str> {
         let account = self.account();
         ACCOUNT_PATTERN

crates/protocols/src/swift/types.rs

@@ -19,7 +19,6 @@ use std::collections::HashMap;
 
 /// Swift container metadata
 #[derive(Debug, Clone, Serialize, Deserialize)]
-#[allow(dead_code)] // Used in container listing operations
 pub struct Container {
     /// Container name
     pub name: String,
@@ -34,7 +33,6 @@ pub struct Container {
 
 /// Swift object metadata
 #[derive(Debug, Clone, Serialize, Deserialize)]
-#[allow(dead_code)] // Used in object listing operations
 pub struct Object {
     /// Object name (key)
     pub name: String,
@@ -50,7 +48,6 @@ pub struct Object {
 
 /// Swift metadata extracted from headers
 #[derive(Debug, Clone, Default)]
-#[allow(dead_code)] // Used by Swift implementation
 pub struct SwiftMetadata {
     /// Custom metadata key-value pairs (from X-Container-Meta-* or X-Object-Meta-*)
     pub metadata: HashMap<String, String>,

crates/rio-v2/tests/minio_fixture_lab/README.md

@@ -34,14 +34,6 @@ MINIO_LAB_PYTHON_IMAGE=public.ecr.aws/docker/library/python:3.12-slim \
 
 Pin the MinIO tag to the same release the Dockerfile names; an unpinned `:latest` captures whatever format that day's build writes, which is not what the interop tests were validated against.
 
-## Capturing the SSE-C cases
-
-MinIO refuses SSE-C over a plain-HTTP connection, so the `sse-c-*` cases cannot be captured against the default endpoint — `./capture_via_docker.sh all` fails on the first SSE-C upload with `InvalidRequest ... must be made over a secure connection`. The lab provisions its own self-signed certificate; point it at the HTTPS endpoint to capture them:
-
-```bash
-MINIO_LAB_ENDPOINT=https://127.0.0.1:9000 ./capture_via_docker.sh all
-```
-
 ## Layout
 
 The default root is `artifacts/minio-fixture-lab`, which is already ignored by the repository.

crates/rio-v2/tests/minio_fixture_lab/capture_via_docker.sh

@@ -12,13 +12,6 @@
 #                                                 # ignored interop tests consume
 #   ./capture_via_docker.sh sse-s3-singlepart-64k # specific case id(s)
 #   ./capture_via_docker.sh all                   # full SSE/size matrix
-#
-# The SSE-C cases are not reachable over the default plain-HTTP endpoint: MinIO
-# refuses SSE-C unless the connection is secure ("Requests specifying Server
-# Side Encryption with Customer provided keys must be made over a secure
-# connection"). Capture those by pointing the lab at its self-signed HTTPS
-# endpoint, which it provisions itself:
-#   MINIO_LAB_ENDPOINT=https://127.0.0.1:9000 ./capture_via_docker.sh all
 set -euo pipefail
 
 IMAGE="${MINIO_LAB_IMAGE:-rustfs-minio-lab:latest}"
@@ -53,10 +46,7 @@ if [ -n "${MINIO_LAB_PYTHON_IMAGE:-}" ]; then
 fi
 
 echo ">> building ${IMAGE}"
-# ${arr[@]+"${arr[@]}"} rather than "${arr[@]}": under `set -u`, bash 3.2 —
-# still the default /bin/bash on macOS — treats an empty array expansion as an
-# unbound variable and aborts.
-docker build -f "${SCRIPT_DIR}/Dockerfile" -t "${IMAGE}" ${build_args[@]+"${build_args[@]}"} "${SCRIPT_DIR}"
+docker build -f "${SCRIPT_DIR}/Dockerfile" -t "${IMAGE}" "${build_args[@]}" "${SCRIPT_DIR}"
 
 echo ">> capturing fixtures into ${FIXTURE_REL}"
 docker run --rm -v "${REPO_ROOT}:/repo" "${IMAGE}" \
@@ -64,7 +54,6 @@ docker run --rm -v "${REPO_ROOT}:/repo" "${IMAGE}" \
     --root "/repo/${FIXTURE_REL}" \
     --work-root /tmp/minio-lab-work \
     --minio-binary /usr/local/bin/minio \
-    --endpoint "${MINIO_LAB_ENDPOINT:-http://127.0.0.1:9000}" \
-    ${case_args[@]+"${case_args[@]}"}
+    "${case_args[@]}"
 
 echo ">> done — fixtures under ${REPO_ROOT}/${FIXTURE_REL}/cases/"

crates/scanner/src/scanner_folder.rs

@@ -4621,6 +4621,8 @@ mod tests {
         let _subscriber_guard = tracing::subscriber::set_default(subscriber);
 
         let (mut scanner, temp_dir) = build_test_scanner().await;
+        // Canonicalize for the "drive" field comparison (scanner resolves symlinks).
+        let canonical_temp_dir = std::fs::canonicalize(&temp_dir).unwrap_or_else(|_| temp_dir.clone());
         let _guard = TestGuard::new(60, 100, &mut scanner, temp_dir.clone());
 
         let object_dir = temp_dir.join("bucket").join("object");
@@ -4689,7 +4691,7 @@ mod tests {
         let fields = &events[0]["fields"];
         assert_eq!(fields["component"], LOG_COMPONENT_SCANNER);
         assert_eq!(fields["subsystem"], LOG_SUBSYSTEM_FOLDER);
-        assert_eq!(fields["drive"], temp_dir.to_string_lossy().as_ref());
+        assert_eq!(fields["drive"], canonical_temp_dir.to_string_lossy().as_ref());
         assert_eq!(fields["bucket"], "bucket");
         assert_eq!(fields["object"], "object");
         assert_eq!(fields["metadata_path"], metadata_path.to_string_lossy().as_ref());

crates/trusted-proxies/src/cloud/metadata/aws.rs

@@ -27,6 +27,10 @@ use crate::CloudMetadataFetcher;
 #[derive(Debug, Clone)]
 pub struct AwsMetadataFetcher {
     client: Client,
+    #[allow(
+        dead_code,
+        reason = "IMDS endpoint retained beside the client it configures; requests build their own URLs (backlog#1823)"
+    )]
     metadata_endpoint: String,
 }
 
@@ -46,55 +50,6 @@ impl AwsMetadataFetcher {
             metadata_endpoint: "http://169.254.169.254".to_string(),
         }
     }
-
-    /// Retrieves an IMDSv2 token for secure metadata access.
-    #[allow(dead_code)]
-    async fn get_metadata_token(&self) -> Result<String, AppError> {
-        let url = format!("{}/latest/api/token", self.metadata_endpoint);
-
-        match self
-            .client
-            .put(&url)
-            .header("X-aws-ec2-metadata-token-ttl-seconds", "21600")
-            .send()
-            .await
-        {
-            Ok(response) => {
-                if response.status().is_success() {
-                    let token = response
-                        .text()
-                        .await
-                        .map_err(|e| AppError::cloud(format!("Failed to read IMDSv2 token: {}", e)))?;
-                    Ok(token)
-                } else {
-                    debug!(
-                        event = "trusted_proxies.cloud_metadata",
-                        component = "trusted_proxies",
-                        subsystem = "aws_metadata",
-                        provider = "aws",
-                        operation = "imdsv2_token",
-                        result = "http_error",
-                        status = %response.status(),
-                        "trusted proxy cloud metadata request failed"
-                    );
-                    Err(AppError::cloud("Failed to obtain IMDSv2 token"))
-                }
-            }
-            Err(e) => {
-                debug!(
-                    event = "trusted_proxies.cloud_metadata",
-                    component = "trusted_proxies",
-                    subsystem = "aws_metadata",
-                    provider = "aws",
-                    operation = "imdsv2_token",
-                    result = "request_failed",
-                    error = %e,
-                    "trusted proxy cloud metadata request failed"
-                );
-                Err(AppError::cloud(format!("IMDSv2 request failed: {}", e)))
-            }
-        }
-    }
 }
 
 #[async_trait]

crates/trusted-proxies/src/config/env.rs

@@ -68,7 +68,6 @@ pub fn is_env_set(key: &str) -> bool {
 }
 
 /// Returns a list of all proxy-related environment variables and their current values.
-#[allow(dead_code)]
 pub fn get_all_proxy_env_vars() -> Vec<(String, String)> {
     let vars = [
         ENV_TRUSTED_PROXY_ENABLED,

crates/utils/src/io.rs

@@ -68,7 +68,6 @@ pub async fn read_full_or_eof<R: AsyncRead + Send + Sync + Unpin>(
 
 /// Read exactly buf.len() bytes into buf, or return an error if EOF is reached before any bytes are read.
 /// Like Go's io.ReadFull.
-#[allow(dead_code)]
 pub async fn read_full<R: AsyncRead + Send + Sync + Unpin>(reader: R, buf: &mut [u8]) -> std::io::Result<usize> {
     match read_full_or_eof(reader, buf).await? {
         Some(n) => Ok(n),

crates/utils/src/net.rs

@@ -431,7 +431,6 @@ pub fn parse_and_resolve_address(addr_str: &str) -> std::io::Result<SocketAddr>
     Ok(resolved_addr)
 }
 
-#[allow(dead_code)]
 pub fn bytes_stream<S, E>(stream: S, content_length: usize) -> impl Stream<Item = Result<Bytes, E>> + Send + 'static
 where
     S: Stream<Item = Result<Bytes, E>> + Send + 'static,

crates/utils/src/os/fs_type.rs

@@ -16,7 +16,6 @@
 ///
 /// The table follows Linux `include/uapi/linux/magic.h`; filesystem magic
 /// values without a stable Linux uapi source stay `UNKNOWN`.
-#[allow(dead_code)]
 pub(crate) fn get_fs_type(fs_type: u64) -> &'static str {
     // Magic numbers for various filesystems.
     match fs_type {

crates/utils/src/path.rs

@@ -70,7 +70,6 @@ pub fn is_dir_object(object: &str) -> bool {
 ///
 /// If the object name ends with `GLOBAL_DIR_SUFFIX`, it is replaced with a slash.
 /// Otherwise, the name is returned as is.
-#[allow(dead_code)]
 pub fn decode_dir_object(object: &str) -> String {
     if has_suffix(object, GLOBAL_DIR_SUFFIX) {
         format!("{}{}", object.trim_end_matches(GLOBAL_DIR_SUFFIX), SLASH_SEPARATOR)

rustfs/src/admin/handlers/scanner.rs

@@ -16,8 +16,8 @@ use crate::admin::auth::validate_admin_request;
 use crate::admin::router::{AdminOperation, Operation, S3Router};
 use crate::admin::runtime_sources::current_scanner_metrics_report;
 use crate::auth::{check_key_valid, get_session_token};
+use crate::module_switches::{ENV_SCANNER_ENABLED, scanner_enabled_from_env};
 use crate::server::{ADMIN_PREFIX, RemoteAddr};
-use crate::startup_background::{ENV_SCANNER_ENABLED, scanner_enabled_from_env};
 use chrono::Utc;
 use http::{HeaderMap, HeaderValue};
 use hyper::{Method, StatusCode};

rustfs/src/admin/handlers/table_catalog/mod.rs

@@ -2995,9 +2995,9 @@ fn table_entry_from_create_table_request(
     let CreateTableRequest {
         name,
         location,
-        schema,
-        partition_spec,
-        write_order,
+        mut schema,
+        mut partition_spec,
+        mut write_order,
         stage_create,
         mut properties,
     } = request;
@@ -3031,6 +3031,9 @@ fn table_entry_from_create_table_request(
     let metadata_location =
         crate::table_catalog::default_table_metadata_file_path(namespace, &table, &next_metadata_file_name(1, &table_id));
 
+    crate::table_catalog::assign_fresh_create_schema_ids(&mut schema, partition_spec.as_mut(), write_order.as_mut())
+        .map_err(catalog_store_error)?;
+
     let entry = crate::table_catalog::TableEntry {
         version: crate::table_catalog::TABLE_CATALOG_ENTRY_VERSION,
         table_bucket: bucket.to_string(),

rustfs/src/admin/handlers/table_catalog/tests.rs

@@ -1873,6 +1873,66 @@ fn create_table_request_accepts_standard_iceberg_rest_shape() {
     assert_eq!(request.name, "events");
 }
 
+#[test]
+fn create_table_assigns_positive_ids_to_spark_schema() {
+    let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
+    let request: CreateTableRequest = serde_json::from_value(serde_json::json!({
+        "name": "events",
+        "schema": {
+            "type": "struct",
+            "schema-id": 0,
+            "fields": [
+                {"id": 0, "name": "id", "required": false, "type": "long"},
+                {"id": 1, "name": "payload", "required": false, "type": "string"}
+            ]
+        },
+        "partition-spec": {"spec-id": 0, "fields": []},
+        "properties": {"owner": "spark"}
+    }))
+    .expect("Spark create table request should parse");
+
+    let (_, metadata) = table_entry_from_create_table_request("warehouse", &namespace, request)
+        .expect("catalog should assign positive field IDs");
+
+    assert_eq!(metadata["schemas"][0]["fields"][0]["id"], 1);
+    assert_eq!(metadata["schemas"][0]["fields"][1]["id"], 2);
+    assert_eq!(metadata["last-column-id"], 2);
+}
+
+#[test]
+fn create_table_assigns_fresh_id_to_negative_temporary_field_id() {
+    let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
+    let request: CreateTableRequest = serde_json::from_value(serde_json::json!({
+        "name": "events",
+        "schema": {
+            "type": "struct",
+            "identifier-field-ids": [-1],
+            "fields": [{"id": -1, "name": "id", "required": true, "type": "long"}]
+        },
+        "partition-spec": {
+            "fields": [{"source-id": -1, "name": "id", "transform": "identity"}]
+        },
+        "write-order": {
+            "fields": [{
+                "source-id": -1,
+                "transform": "identity",
+                "direction": "asc",
+                "null-order": "nulls-first"
+            }]
+        }
+    }))
+    .expect("create table request with a negative temporary field ID should parse");
+
+    let (_, metadata) = table_entry_from_create_table_request("warehouse", &namespace, request)
+        .expect("catalog should replace the negative temporary field ID");
+
+    assert_eq!(metadata["schemas"][0]["fields"][0]["id"], 1);
+    assert_eq!(metadata["schemas"][0]["identifier-field-ids"], serde_json::json!([1]));
+    assert_eq!(metadata["partition-specs"][0]["fields"][0]["source-id"], 1);
+    assert_eq!(metadata["sort-orders"][0]["fields"][0]["source-id"], 1);
+    assert_eq!(metadata["last-column-id"], 1);
+}
+
 #[test]
 fn create_table_request_honors_supported_format_version_property() {
     let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
@@ -1990,6 +2050,142 @@ fn catalog_assigns_read_only_schema_spec_and_sort_order_ids() {
     assert_eq!(updated["default-sort-order-id"], 0);
 }
 
+#[test]
+fn create_table_assigns_fresh_schema_field_ids_and_rewrites_references() {
+    let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
+    let request: CreateTableRequest = serde_json::from_value(serde_json::json!({
+        "name": "events",
+        "schema": {
+            "type": "struct",
+            "schema-id": 41,
+            "identifier-field-ids": [0],
+            "fields": [
+                {"id": 0, "name": "id", "required": true, "type": "long"},
+                {
+                    "id": 10,
+                    "name": "details",
+                    "required": false,
+                    "type": {
+                        "type": "struct",
+                        "fields": [{"id": 11, "name": "category", "required": false, "type": "string"}]
+                    }
+                },
+                {
+                    "id": 20,
+                    "name": "tags",
+                    "required": false,
+                    "type": {
+                        "type": "list",
+                        "element-id": 21,
+                        "element-required": false,
+                        "element": "string"
+                    }
+                },
+                {
+                    "id": 30,
+                    "name": "attributes",
+                    "required": false,
+                    "type": {
+                        "type": "map",
+                        "key-id": 31,
+                        "key": "string",
+                        "value-id": 32,
+                        "value-required": false,
+                        "value": {
+                            "type": "struct",
+                            "fields": [{"id": 33, "name": "score", "required": false, "type": "int"}]
+                        }
+                    }
+                }
+            ]
+        },
+        "partition-spec": {
+            "spec-id": 42,
+            "fields": [{"source-id": 0, "name": "id", "transform": "identity"}]
+        },
+        "write-order": {
+            "order-id": 43,
+            "fields": [{
+                "source-id": 11,
+                "transform": "identity",
+                "direction": "asc",
+                "null-order": "nulls-first"
+            }]
+        }
+    }))
+    .expect("create table request should parse");
+
+    let (_, metadata) =
+        table_entry_from_create_table_request("warehouse", &namespace, request).expect("catalog should assign fresh field IDs");
+
+    let schema = &metadata["schemas"][0];
+    assert_eq!(schema["fields"][0]["id"], 1);
+    assert_eq!(schema["fields"][1]["id"], 2);
+    assert_eq!(schema["fields"][2]["id"], 3);
+    assert_eq!(schema["fields"][3]["id"], 4);
+    assert_eq!(schema["fields"][1]["type"]["fields"][0]["id"], 5);
+    assert_eq!(schema["fields"][2]["type"]["element-id"], 6);
+    assert_eq!(schema["fields"][3]["type"]["key-id"], 7);
+    assert_eq!(schema["fields"][3]["type"]["value-id"], 8);
+    assert_eq!(schema["fields"][3]["type"]["value"]["fields"][0]["id"], 9);
+    assert_eq!(schema["identifier-field-ids"], serde_json::json!([1]));
+    assert_eq!(metadata["last-column-id"], 9);
+    assert_eq!(metadata["partition-specs"][0]["fields"][0]["source-id"], 1);
+    assert_eq!(metadata["sort-orders"][0]["fields"][0]["source-id"], 5);
+}
+
+#[test]
+fn create_table_rejects_duplicate_temporary_schema_field_ids() {
+    let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
+    let request: CreateTableRequest = serde_json::from_value(serde_json::json!({
+        "name": "events",
+        "schema": {
+            "type": "struct",
+            "fields": [
+                {"id": 0, "name": "id", "required": false, "type": "long"},
+                {"id": 0, "name": "payload", "required": false, "type": "string"}
+            ]
+        }
+    }))
+    .expect("create table request should parse");
+
+    let error = table_entry_from_create_table_request("warehouse", &namespace, request)
+        .expect_err("duplicate temporary field IDs must be rejected");
+
+    assert_eq!(error.message(), Some("duplicate create schema field id 0"));
+}
+
+#[test]
+fn create_table_rejects_excessive_schema_nesting() {
+    let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
+    let mut field_type = serde_json::Value::from("long");
+    for element_id in 1..=crate::table_catalog::ICEBERG_MAX_SCHEMA_NESTING_DEPTH + 1 {
+        field_type = serde_json::json!({
+            "type": "list",
+            "element-id": element_id,
+            "element-required": false,
+            "element": field_type
+        });
+    }
+    let request = CreateTableRequest {
+        name: "events".to_string(),
+        location: None,
+        schema: serde_json::json!({
+            "type": "struct",
+            "fields": [{"id": 0, "name": "nested", "required": false, "type": field_type}]
+        }),
+        partition_spec: None,
+        write_order: None,
+        stage_create: false,
+        properties: BTreeMap::new(),
+    };
+
+    let error = table_entry_from_create_table_request("warehouse", &namespace, request)
+        .expect_err("excessively nested create schemas must be rejected");
+
+    assert_eq!(error.message(), Some("create schema exceeds the maximum nesting depth"));
+}
+
 #[test]
 fn standard_commit_binds_new_specs_and_sort_orders_to_current_schema() {
     let namespace = crate::table_catalog::Namespace::parse("analytics").expect("namespace should parse");
@@ -2247,7 +2443,11 @@ fn create_table_counts_collection_ids_in_last_column_id() {
     let (_, metadata) =
         table_entry_from_create_table_request("warehouse", &namespace, request).expect("table metadata should be created");
 
-    assert_eq!(metadata["last-column-id"], 9);
+    let schema = &metadata["schemas"][0];
+    assert_eq!(schema["fields"][0]["type"]["element-id"], 3);
+    assert_eq!(schema["fields"][1]["type"]["key-id"], 4);
+    assert_eq!(schema["fields"][1]["type"]["value-id"], 5);
+    assert_eq!(metadata["last-column-id"], 5);
 }
 
 #[test]

rustfs/src/app/object_usecase.rs

@@ -1074,7 +1074,7 @@ where
 }
 
 impl futures::Stream for MemoryTrackedBytesStream {
-    type Item = std::io::Result<Bytes>;
+    type Item = Result<Bytes, S3StdError>;
 
     fn poll_next(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let this = self.get_mut();
@@ -1105,7 +1105,8 @@ impl futures::Stream for MemoryTrackedBytesStream {
             return Poll::Ready(Some(Err(std::io::Error::new(
                 std::io::ErrorKind::InvalidData,
                 format!("materialized GET body length mismatch: expected {}, got {}", this.expected, actual),
-            ))));
+            )
+            .into())));
         }
 
         let Some(bytes) = this.bytes.take() else {
@@ -1132,6 +1133,16 @@ impl futures::Stream for MemoryTrackedBytesStream {
     }
 }
 
+impl ByteStream for MemoryTrackedBytesStream {
+    fn remaining_length(&self) -> RemainingLength {
+        if self.emitted || self.bytes.is_none() {
+            RemainingLength::new_exact(0)
+        } else {
+            RemainingLength::new_exact(self.expected)
+        }
+    }
+}
+
 impl Drop for MemoryTrackedBytesStream {
     fn drop(&mut self) {
         if self.lifecycle.is_finished() {
@@ -4149,7 +4160,7 @@ impl DefaultObjectUsecase {
         let bytes_len = bytes.len();
         let guard = rustfs_io_metrics::track_get_object_buffered_bytes(bytes_len);
         let remaining = usize::try_from(response_content_length.max(0)).unwrap_or(usize::MAX);
-        let blob = StreamingBlob::wrap(MemoryTrackedBytesStream::new(bytes, remaining, source, guard, lifecycle));
+        let blob = StreamingBlob::new(MemoryTrackedBytesStream::new(bytes, remaining, source, guard, lifecycle));
         if let Some(handoff_start) = handoff_start {
             rustfs_io_metrics::record_get_object_response_handoff(
                 "single_chunk",
@@ -12882,7 +12893,10 @@ mod tests {
             .await
             .expect("mismatched memory body must yield an item")
             .expect_err("a short memory body must fail the stream instead of serving a truncated body");
-        assert_eq!(err.kind(), std::io::ErrorKind::InvalidData);
+        assert_eq!(
+            err.downcast_ref::<std::io::Error>().map(std::io::Error::kind),
+            Some(std::io::ErrorKind::InvalidData)
+        );
         assert!(stream.next().await.is_none(), "stream must terminate after the error");
     }
 
@@ -12901,7 +12915,22 @@ mod tests {
             .await
             .expect("mismatched memory body must yield an item")
             .expect_err("an over-long memory body must fail the stream instead of serving mismatched bytes");
-        assert_eq!(err.kind(), std::io::ErrorKind::InvalidData);
+        assert_eq!(
+            err.downcast_ref::<std::io::Error>().map(std::io::Error::kind),
+            Some(std::io::ErrorKind::InvalidData)
+        );
+    }
+
+    #[test]
+    fn memory_blob_preserves_exact_remaining_length() {
+        let blob = DefaultObjectUsecase::build_memory_bytes_blob(
+            Bytes::from_static(b"hello"),
+            5,
+            GET_MEMORY_BODY_SOURCE_BUFFERED_BODY,
+            GetObjectBodyLifecycle::disabled(),
+        );
+
+        assert_eq!(blob.remaining_length().exact(), Some(5));
     }
 
     #[tokio::test]

rustfs/src/lib.rs

@@ -88,6 +88,7 @@ pub mod inspect;
 pub(crate) mod kms_deletion_gate;
 pub mod license;
 pub mod memory_observability;
+pub mod module_switches;
 pub mod profiling;
 #[cfg(any(feature = "ftps", feature = "webdav", feature = "sftp"))]
 pub mod protocols;

rustfs/src/module_switches.rs

@@ -0,0 +1,68 @@
+// 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.
+
+//! Layer-neutral module switches (backlog#1834).
+//!
+//! Whether the scanner, heal, audit and notify modules are on is read from the
+//! infra layer (storage helpers, node-service RPC) and from the interface layer
+//! (admin handlers), but the switches used to live in `startup_background`
+//! (composition) and `server` (interface). Every lower-layer read was therefore
+//! an upward edge that had to be baselined by the layer-dependency guard.
+//!
+//! The env-derived scanner/heal predicates and the audit/notify state cells now
+//! live here, at the bottom of the layer order, so those reads are ordinary
+//! downward edges. Resolving the audit/notify state still needs server-side
+//! configuration, so `server::refresh_audit_module_enabled` and its notify twin
+//! keep that logic and publish the result through the setters below.
+
+use rustfs_utils::get_env_bool_with_aliases;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+pub(crate) const ENV_SCANNER_ENABLED: &str = "RUSTFS_SCANNER_ENABLED";
+pub(crate) const ENV_SCANNER_ENABLED_DEPRECATED: &str = "RUSTFS_ENABLE_SCANNER";
+pub(crate) const ENV_HEAL_ENABLED: &str = "RUSTFS_HEAL_ENABLED";
+pub(crate) const ENV_HEAL_ENABLED_DEPRECATED: &str = "RUSTFS_ENABLE_HEAL";
+
+static AUDIT_MODULE_ENABLED: AtomicBool = AtomicBool::new(rustfs_config::DEFAULT_AUDIT_ENABLE);
+static NOTIFY_MODULE_ENABLED: AtomicBool = AtomicBool::new(rustfs_config::DEFAULT_NOTIFY_ENABLE);
+
+/// Whether the data scanner is enabled, defaulting to on.
+pub(crate) fn scanner_enabled_from_env() -> bool {
+    get_env_bool_with_aliases(ENV_SCANNER_ENABLED, &[ENV_SCANNER_ENABLED_DEPRECATED], true)
+}
+
+/// Whether background heal is enabled, defaulting to on.
+pub(crate) fn heal_enabled_from_env() -> bool {
+    get_env_bool_with_aliases(ENV_HEAL_ENABLED, &[ENV_HEAL_ENABLED_DEPRECATED], true)
+}
+
+/// Last published audit-module state.
+pub fn is_audit_module_enabled() -> bool {
+    AUDIT_MODULE_ENABLED.load(Ordering::Relaxed)
+}
+
+/// Publish the audit-module state resolved by `server::refresh_audit_module_enabled`.
+pub(crate) fn set_audit_module_enabled(enabled: bool) {
+    AUDIT_MODULE_ENABLED.store(enabled, Ordering::Relaxed);
+}
+
+/// Last published notify-module state.
+pub fn is_notify_module_enabled() -> bool {
+    NOTIFY_MODULE_ENABLED.load(Ordering::Relaxed)
+}
+
+/// Publish the notify-module state resolved by `server::refresh_notify_module_enabled`.
+pub(crate) fn set_notify_module_enabled(enabled: bool) {
+    NOTIFY_MODULE_ENABLED.store(enabled, Ordering::Relaxed);
+}

rustfs/src/server/audit.rs

@@ -19,11 +19,8 @@ use super::{
 use crate::runtime_sources::AppContext;
 use rustfs_audit::{AuditError, AuditResult, audit_system, init_audit_system, system::AuditSystemState};
 use std::collections::HashSet;
-use std::sync::atomic::{AtomicBool, Ordering};
 use tracing::{info, warn};
 
-static AUDIT_MODULE_ENABLED: AtomicBool = AtomicBool::new(rustfs_config::DEFAULT_AUDIT_ENABLE);
-
 fn server_config_from_context() -> Option<rustfs_config::server_config::Config> {
     runtime_sources::current_server_config()
 }
@@ -37,13 +34,11 @@ fn server_config_for_context(context: Option<&AppContext>) -> Option<rustfs_conf
 
 pub fn refresh_audit_module_enabled() -> bool {
     let enabled = resolve_audit_module_state().enabled;
-    AUDIT_MODULE_ENABLED.store(enabled, Ordering::Relaxed);
+    crate::module_switches::set_audit_module_enabled(enabled);
     enabled
 }
 
-pub fn is_audit_module_enabled() -> bool {
-    AUDIT_MODULE_ENABLED.load(Ordering::Relaxed)
-}
+pub use crate::module_switches::is_audit_module_enabled;
 
 fn has_any_persisted_audit_targets(config: &rustfs_config::server_config::Config) -> bool {
     for &subsystem in rustfs_config::audit::AUDIT_SUB_SYSTEMS {

rustfs/src/server/event.rs

@@ -34,7 +34,6 @@ use tokio::time::{Instant, MissedTickBehavior};
 use tokio_util::sync::CancellationToken;
 use tracing::{info, instrument, warn};
 
-static NOTIFY_MODULE_ENABLED: AtomicBool = AtomicBool::new(rustfs_config::DEFAULT_NOTIFY_ENABLE);
 static NOTIFY_RUNTIME_RECONCILED: AtomicBool = AtomicBool::new(false);
 static NOTIFY_BUCKET_RULES_RECONCILED: AtomicBool = AtomicBool::new(false);
 static ECSTORE_EVENT_DISPATCH_HOOK: OnceLock<()> = OnceLock::new();
@@ -70,13 +69,11 @@ fn should_reconcile_bucket_notification_rules(runtime_changed: bool, notify_enab
 
 pub fn refresh_notify_module_enabled() -> bool {
     let enabled = resolve_notify_module_state().enabled;
-    NOTIFY_MODULE_ENABLED.store(enabled, Ordering::Relaxed);
+    crate::module_switches::set_notify_module_enabled(enabled);
     enabled
 }
 
-pub fn is_notify_module_enabled() -> bool {
-    NOTIFY_MODULE_ENABLED.load(Ordering::Relaxed)
-}
+pub use crate::module_switches::is_notify_module_enabled;
 
 pub(crate) use crate::shared_types::convert_ecstore_object_info;
 
@@ -171,7 +168,7 @@ pub(crate) async fn reconcile_event_notifier_from_store(
         let transition_system = system.clone();
         let transition_store = store.clone();
         let transition = with_refreshed_notify_module_state_from(store.clone(), move |resolution| async move {
-            NOTIFY_MODULE_ENABLED.store(resolution.enabled, Ordering::Relaxed);
+            crate::module_switches::set_notify_module_enabled(resolution.enabled);
             let read_store = transition_store.clone();
             let config_system = transition_system.clone();
             with_server_config_read_lock(transition_store, move || async move {

rustfs/src/startup_background.rs

@@ -12,32 +12,20 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use crate::module_switches::{heal_enabled_from_env, scanner_enabled_from_env};
 use crate::storage_api::startup::background::{ECStore, set_workload_admission_snapshot_provider};
 use crate::workload_admission::RustFsWorkloadAdmissionSnapshotProvider;
 use rustfs_concurrency::WorkloadAdmissionSnapshotProvider;
 use rustfs_heal::{
     create_ahm_services_cancel_token, heal::storage::ECStoreHealStorage, init_heal_manager_with_workload_provider,
 };
-use rustfs_utils::get_env_bool_with_aliases;
 use std::{io::Result, sync::Arc};
 use tracing::{debug, info};
 
-pub(crate) const ENV_SCANNER_ENABLED: &str = "RUSTFS_SCANNER_ENABLED";
-pub(crate) const ENV_SCANNER_ENABLED_DEPRECATED: &str = "RUSTFS_ENABLE_SCANNER";
-pub(crate) const ENV_HEAL_ENABLED: &str = "RUSTFS_HEAL_ENABLED";
-pub(crate) const ENV_HEAL_ENABLED_DEPRECATED: &str = "RUSTFS_ENABLE_HEAL";
 const LOG_COMPONENT_MAIN: &str = "main";
 const LOG_SUBSYSTEM_STARTUP: &str = "startup";
 const EVENT_BACKGROUND_SERVICES_CONFIGURED: &str = "background_services_configured";
 
-pub(crate) fn scanner_enabled_from_env() -> bool {
-    get_env_bool_with_aliases(ENV_SCANNER_ENABLED, &[ENV_SCANNER_ENABLED_DEPRECATED], true)
-}
-
-pub(crate) fn heal_enabled_from_env() -> bool {
-    get_env_bool_with_aliases(ENV_HEAL_ENABLED, &[ENV_HEAL_ENABLED_DEPRECATED], true)
-}
-
 pub(crate) async fn init_background_service_runtime(store: Arc<ECStore>) -> Result<bool> {
     let _ = create_ahm_services_cancel_token();
 

rustfs/src/storage/deadlock_detector.rs

@@ -56,7 +56,6 @@
 //! ```
 
 // Allow dead_code for public API that may be used by external modules or future features
-#![allow(dead_code)]
 
 use parking_lot::{Mutex, RwLock};
 use std::collections::{HashMap, HashSet};
@@ -264,6 +263,10 @@ pub struct ResourceUsage {
 /// Deadlock detector.
 pub struct DeadlockDetector {
     /// Configuration.
+    #[allow(
+        dead_code,
+        reason = "policy snapshot retained beside the detector it configures (backlog#1823)"
+    )]
     config: RequestHangDetectionPolicy,
     /// Shared concurrency facade policy.
     policy: DeadlockMonitorPolicy,

rustfs/src/storage/helper.rs

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::server::{is_audit_module_enabled, is_notify_module_enabled};
+use crate::module_switches::{is_audit_module_enabled, is_notify_module_enabled};
 use crate::shared_types::convert_ecstore_object_info;
 use crate::storage::access::{ReqInfo, request_context_from_req};
 use crate::storage::request_context::RequestContext;

rustfs/src/storage/lock_optimizer.rs

@@ -31,7 +31,6 @@
 //! ```
 
 // Allow dead_code for public API that may be used by external modules or future features
-#![allow(dead_code)]
 //! # Key Features
 //!
 //! - Early lock release after metadata read

rustfs/src/storage/rpc/node_service/heal.rs

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::startup_background::{heal_enabled_from_env, scanner_enabled_from_env};
+use crate::module_switches::{heal_enabled_from_env, scanner_enabled_from_env};
 use crate::storage::storage_api::runtime_sources_consumer::EndpointServerPools;
 use jiff::Timestamp;
 use rmp_serde::Deserializer;

rustfs/src/storage/s3_api/mod.rs

@@ -12,8 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#![allow(dead_code)]
-
 //! Facade modules for incremental S3 API extraction from `ecfs.rs`.
 //!
 //! This file intentionally starts as skeleton-only. Behavior remains in place
@@ -29,18 +27,6 @@ pub(crate) mod common;
 pub(crate) mod multipart;
 pub(crate) mod tagging;
 
-pub(crate) fn default_bucket_usecase() -> DefaultBucketUsecase {
-    DefaultBucketUsecase::from_global()
-}
-
-pub(crate) fn default_multipart_usecase() -> DefaultMultipartUsecase {
-    DefaultMultipartUsecase::from_global()
-}
-
-pub(crate) fn default_object_usecase() -> DefaultObjectUsecase {
-    DefaultObjectUsecase::from_global()
-}
-
 /// Resolve the object use-case for a server's request path (backlog#1052 S6):
 /// bind it to the server's own application context so it resolves that
 /// server's store instead of the ambient process default.

rustfs/src/table_catalog/iceberg/manifest.rs

@@ -71,6 +71,10 @@ pub(crate) struct DecodedManifest {
     pub partition_spec_id: Option<i32>,
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn manifest_paths_from_manifest_list_avro(data: &[u8]) -> TableCatalogStoreResult<Vec<String>> {
     Ok(manifest_list_references_from_manifest_list_avro(data)?
         .into_iter()
@@ -78,6 +82,10 @@ pub(crate) fn manifest_paths_from_manifest_list_avro(data: &[u8]) -> TableCatalo
         .collect())
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn manifest_list_references_from_manifest_list_avro(
     data: &[u8],
 ) -> TableCatalogStoreResult<Vec<ManifestListReference>> {
@@ -157,6 +165,10 @@ pub(crate) async fn decode_manifest_list_avro_async(data: Vec<u8>) -> TableCatal
         .map_err(|err| TableCatalogStoreError::Internal(format!("manifest-list parser task failed: {err}")))?
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn file_references_from_manifest_avro(
     data: &[u8],
 ) -> TableCatalogStoreResult<Vec<(String, TableMetadataMaintenanceObjectKind)>> {
@@ -166,6 +178,10 @@ pub(crate) fn file_references_from_manifest_avro(
         .collect())
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn data_file_references_from_manifest_avro(data: &[u8]) -> TableCatalogStoreResult<Vec<ManifestDataFileReference>> {
     Ok(decode_manifest_avro(data)?.references)
 }

rustfs/src/table_catalog/iceberg/validation.rs

@@ -19,6 +19,7 @@ use futures::{StreamExt, TryStreamExt, stream};
 use super::super::*;
 
 const ICEBERG_MAX_USER_FIELD_ID: i32 = i32::MAX - 200;
+pub(crate) const ICEBERG_MAX_SCHEMA_NESTING_DEPTH: usize = 128;
 
 fn normalize_warehouse_object_prefix(object_prefix: &str, max_prefix_depth: Option<usize>) -> TableCatalogStoreResult<String> {
     let object_prefix = object_prefix.strip_suffix('/').unwrap_or(object_prefix);
@@ -103,6 +104,10 @@ pub(crate) fn table_warehouse_index_entry(entry: &TableEntry) -> TableCatalogSto
     })
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 fn table_warehouse_data_dir_path(entry: &TableEntry) -> TableCatalogStoreResult<String> {
     Ok(format!("{}{}", table_warehouse_object_prefix(entry)?, DATA_DIR))
 }
@@ -1357,6 +1362,188 @@ fn validate_iceberg_schema(schema: &serde_json::Value, label: &str) -> TableCata
     Ok(validate_iceberg_schema_fields(schema, label)?.field_ids)
 }
 
+pub(crate) fn assign_fresh_create_schema_ids(
+    schema: &mut serde_json::Value,
+    partition_spec: Option<&mut serde_json::Value>,
+    sort_order: Option<&mut serde_json::Value>,
+) -> TableCatalogStoreResult<()> {
+    let mut assigner = FreshCreateSchemaIdAssigner::new();
+    assigner.assign_schema(schema)?;
+    assigner.remap_identifier_field_ids(schema)?;
+    if let Some(partition_spec) = partition_spec {
+        assigner.remap_source_ids(partition_spec, "partition spec")?;
+    }
+    if let Some(sort_order) = sort_order {
+        assigner.remap_source_ids(sort_order, "sort order")?;
+    }
+    Ok(())
+}
+
+struct FreshCreateSchemaIdAssigner {
+    next_id: i32,
+    old_to_new: BTreeMap<i32, i32>,
+}
+
+impl FreshCreateSchemaIdAssigner {
+    fn new() -> Self {
+        Self {
+            next_id: 1,
+            old_to_new: BTreeMap::new(),
+        }
+    }
+
+    fn assign_schema(&mut self, schema: &mut serde_json::Value) -> TableCatalogStoreResult<()> {
+        let schema = schema
+            .as_object_mut()
+            .ok_or_else(|| TableCatalogStoreError::Invalid("create schema must be a JSON object".to_string()))?;
+        if schema.get("type").and_then(serde_json::Value::as_str) != Some("struct") {
+            return Err(TableCatalogStoreError::Invalid("create schema type must be struct".to_string()));
+        }
+        let fields = schema
+            .get_mut("fields")
+            .and_then(serde_json::Value::as_array_mut)
+            .ok_or_else(|| TableCatalogStoreError::Invalid("create schema fields must be an array".to_string()))?;
+        self.assign_struct_fields(fields, 0)
+    }
+
+    fn assign_struct_fields(&mut self, fields: &mut [serde_json::Value], depth: usize) -> TableCatalogStoreResult<()> {
+        for field in fields.iter_mut() {
+            let field = field
+                .as_object_mut()
+                .ok_or_else(|| TableCatalogStoreError::Invalid("create schema fields must be JSON objects".to_string()))?;
+            self.assign_object_id(field, "id", "create schema field id")?;
+        }
+        for field in fields {
+            let field = field
+                .as_object_mut()
+                .ok_or_else(|| TableCatalogStoreError::Invalid("create schema fields must be JSON objects".to_string()))?;
+            let field_type = field
+                .get_mut("type")
+                .ok_or_else(|| TableCatalogStoreError::Invalid("create schema field type is required".to_string()))?;
+            self.assign_type_ids(field_type, depth)?;
+        }
+        Ok(())
+    }
+
+    fn assign_type_ids(&mut self, field_type: &mut serde_json::Value, depth: usize) -> TableCatalogStoreResult<()> {
+        if field_type.is_string() {
+            return Ok(());
+        }
+        if depth >= ICEBERG_MAX_SCHEMA_NESTING_DEPTH {
+            return Err(TableCatalogStoreError::Invalid(
+                "create schema exceeds the maximum nesting depth".to_string(),
+            ));
+        }
+        let nested_depth = depth + 1;
+        let field_type = field_type.as_object_mut().ok_or_else(|| {
+            TableCatalogStoreError::Invalid("create schema field type must be a string or JSON object".to_string())
+        })?;
+        match field_type.get("type").and_then(serde_json::Value::as_str) {
+            Some("struct") => {
+                let fields = field_type
+                    .get_mut("fields")
+                    .and_then(serde_json::Value::as_array_mut)
+                    .ok_or_else(|| TableCatalogStoreError::Invalid("create schema struct fields must be an array".to_string()))?;
+                self.assign_struct_fields(fields, nested_depth)
+            }
+            Some("list") => {
+                self.assign_object_id(field_type, "element-id", "create schema list element-id")?;
+                let element = field_type
+                    .get_mut("element")
+                    .ok_or_else(|| TableCatalogStoreError::Invalid("create schema list element is required".to_string()))?;
+                self.assign_type_ids(element, nested_depth)
+            }
+            Some("map") => {
+                self.assign_object_id(field_type, "key-id", "create schema map key-id")?;
+                self.assign_object_id(field_type, "value-id", "create schema map value-id")?;
+                let key = field_type
+                    .get_mut("key")
+                    .ok_or_else(|| TableCatalogStoreError::Invalid("create schema map key is required".to_string()))?;
+                self.assign_type_ids(key, nested_depth)?;
+                let value = field_type
+                    .get_mut("value")
+                    .ok_or_else(|| TableCatalogStoreError::Invalid("create schema map value is required".to_string()))?;
+                self.assign_type_ids(value, nested_depth)
+            }
+            _ => Err(TableCatalogStoreError::Invalid(
+                "create schema contains an unsupported field type".to_string(),
+            )),
+        }
+    }
+
+    fn assign_object_id(
+        &mut self,
+        object: &mut serde_json::Map<String, serde_json::Value>,
+        field: &str,
+        label: &str,
+    ) -> TableCatalogStoreResult<()> {
+        let old_id = required_i32_value(object, field, label)?;
+        let entry = match self.old_to_new.entry(old_id) {
+            std::collections::btree_map::Entry::Occupied(_) => {
+                return Err(TableCatalogStoreError::Invalid(format!("duplicate create schema field id {old_id}")));
+            }
+            std::collections::btree_map::Entry::Vacant(entry) => entry,
+        };
+        let new_id = self.next_id;
+        if new_id > ICEBERG_MAX_USER_FIELD_ID {
+            return Err(TableCatalogStoreError::Invalid(
+                "create schema exceeds the available Iceberg field ID range".to_string(),
+            ));
+        }
+        self.next_id = new_id.checked_add(1).ok_or_else(|| {
+            TableCatalogStoreError::Invalid("create schema exceeds the available Iceberg field ID range".to_string())
+        })?;
+        entry.insert(new_id);
+        object.insert(field.to_string(), serde_json::Value::from(new_id));
+        Ok(())
+    }
+
+    fn remap_identifier_field_ids(&self, schema: &mut serde_json::Value) -> TableCatalogStoreResult<()> {
+        let Some(identifier_field_ids) = schema
+            .as_object_mut()
+            .and_then(|schema| schema.get_mut("identifier-field-ids"))
+        else {
+            return Ok(());
+        };
+        let identifier_field_ids = identifier_field_ids
+            .as_array_mut()
+            .ok_or_else(|| TableCatalogStoreError::Invalid("create schema identifier-field-ids must be an array".to_string()))?;
+        for field_id in identifier_field_ids {
+            let old_id = required_i32(field_id, "create schema identifier field id")?;
+            let new_id = self.old_to_new.get(&old_id).ok_or_else(|| {
+                TableCatalogStoreError::Invalid(format!(
+                    "create schema identifier field id {old_id} does not reference a schema field"
+                ))
+            })?;
+            *field_id = serde_json::Value::from(*new_id);
+        }
+        Ok(())
+    }
+
+    fn remap_source_ids(&self, value: &mut serde_json::Value, label: &str) -> TableCatalogStoreResult<()> {
+        let value = value
+            .as_object_mut()
+            .ok_or_else(|| TableCatalogStoreError::Invalid(format!("{label} must be a JSON object")))?;
+        let Some(fields) = value.get_mut("fields") else {
+            return Ok(());
+        };
+        let fields = fields
+            .as_array_mut()
+            .ok_or_else(|| TableCatalogStoreError::Invalid(format!("{label} fields must be an array")))?;
+        for field in fields {
+            let field = field
+                .as_object_mut()
+                .ok_or_else(|| TableCatalogStoreError::Invalid(format!("{label} fields must be JSON objects")))?;
+            let old_id = required_i32_value(field, "source-id", &format!("{label} source-id"))?;
+            let new_id = self.old_to_new.get(&old_id).ok_or_else(|| {
+                TableCatalogStoreError::Invalid(format!("{label} source-id {old_id} does not reference the create schema"))
+            })?;
+            field.insert("source-id".to_string(), serde_json::Value::from(*new_id));
+        }
+        Ok(())
+    }
+}
+
 fn validate_iceberg_schema_fields(schema: &serde_json::Value, label: &str) -> TableCatalogStoreResult<IcebergSchemaFields> {
     let schema = schema
         .as_object()
@@ -2414,11 +2601,35 @@ struct SnapshotGraphManifestLocation {
     sequence_number: Option<i64>,
     min_sequence_number: Option<i64>,
     added_snapshot_id: Option<i64>,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     added_files_count: Option<u64>,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     existing_files_count: Option<u64>,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     deleted_files_count: Option<u64>,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     added_rows_count: Option<u64>,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     existing_rows_count: Option<u64>,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     deleted_rows_count: Option<u64>,
     from_manifest_list: bool,
 }

rustfs/src/table_catalog/identifier.rs

@@ -87,6 +87,10 @@ impl Namespace {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub struct TableIdentifier {
     warehouse: IdentifierSegment,
     namespace: Namespace,
@@ -94,6 +98,10 @@ pub struct TableIdentifier {
 }
 
 impl TableIdentifier {
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn new(warehouse: IdentifierSegment, namespace: Namespace, name: IdentifierSegment) -> Self {
         Self {
             warehouse,
@@ -116,6 +124,10 @@ impl TableIdentifier {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub struct TablePathResolver {
     reserved_prefix: &'static str,
 }
@@ -129,14 +141,26 @@ impl Default for TablePathResolver {
 }
 
 impl TablePathResolver {
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn current_pointer_path(&self, table: &TableIdentifier) -> String {
         format!("{}/{}", self.table_root(table), CURRENT_POINTER_FILE)
     }
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn metadata_dir_path(&self, table: &TableIdentifier) -> String {
         format!("{}/{}", self.table_root(table), METADATA_DIR)
     }
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn metadata_file_path(&self, table: &TableIdentifier, metadata_file_name: &str) -> String {
         format!("{}/{}", self.metadata_dir_path(table), metadata_file_name)
     }
@@ -169,6 +193,10 @@ pub(crate) fn default_namespace_root_prefix() -> String {
     )
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn default_namespace_marker_path(namespace: &Namespace) -> String {
     format!("{}{}/{}", default_namespace_root_prefix(), namespace.storage_id(), NAMESPACE_MARKER_FILE)
 }
@@ -185,6 +213,10 @@ pub(crate) fn default_table_bucket_publication_lock_path() -> String {
     rustfs_common::table_catalog::TABLE_BUCKET_PUBLICATION_LOCK_PATH.to_string()
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn default_table_marker_path(namespace: &Namespace, table: &IdentifierSegment) -> String {
     format!("{}{}/{}", default_table_root_prefix(namespace), table.as_str(), TABLE_MARKER_FILE)
 }
@@ -225,14 +257,26 @@ pub(crate) fn default_table_metadata_file_path(
     format!("{}/{}", default_table_metadata_dir_path(namespace, table), metadata_file_name)
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn default_table_current_pointer_path(namespace: &Namespace, table: &IdentifierSegment) -> String {
     format!("{}{}/{}", default_table_root_prefix(namespace), table.as_str(), CURRENT_POINTER_FILE)
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn default_table_lifecycle_path(namespace: &Namespace, table: &IdentifierSegment) -> String {
     format!("{}{}/{}", default_table_root_prefix(namespace), table.as_str(), LIFECYCLE_FILE)
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn namespace_name_from_marker_path(object_key: &str) -> Option<String> {
     let prefix = default_namespace_root_prefix();
     let suffix = format!("/{NAMESPACE_MARKER_FILE}");
@@ -244,6 +288,10 @@ pub(crate) fn namespace_name_from_marker_path(object_key: &str) -> Option<String
         .map(|value| value.replace('/', "."))
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn table_name_from_marker_path(namespace: &Namespace, object_key: &str) -> Option<String> {
     let prefix = default_table_root_prefix(namespace);
     let suffix = format!("/{TABLE_MARKER_FILE}");

rustfs/src/table_catalog/mod.rs

@@ -18,8 +18,6 @@
 //! S3 object behavior. It defines the stable internal boundary that later
 //! catalog routes and object guards can share.
 
-#![allow(dead_code)]
-
 use std::{
     collections::{BTreeMap, BTreeSet},
     num::NonZeroUsize,
@@ -87,8 +85,20 @@ pub(crate) const RESERVED_CATALOG_OBJECT_MESSAGE: &str = "Object key is reserved
 pub(crate) const TABLE_BUCKET_CATALOG_TYPE: &str = "iceberg-rest";
 pub(crate) const TABLE_BUCKET_CONFIG_VERSION: u16 = 1;
 pub(crate) const DEFAULT_WAREHOUSE_ID: &str = "default";
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) const TABLE_NAMESPACE_MARKER_VERSION: u16 = 1;
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) const TABLE_RESOURCE_MARKER_VERSION: u16 = 1;
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) const TABLE_METADATA_POINTER_VERSION: u16 = 1;
 pub(crate) const TABLE_CATALOG_ENTRY_VERSION: u16 = 1;
 pub(crate) const TABLE_WAREHOUSE_INDEX_STATE_VERSION: u16 = 2;
@@ -123,9 +133,25 @@ const WAREHOUSE_ROOT: &str = "warehouses";
 const NAMESPACE_ROOT: &str = "namespaces";
 const TABLE_ROOT: &str = "tables";
 const VIEW_ROOT: &str = "views";
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 const NAMESPACE_MARKER_FILE: &str = "namespace.json";
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 const TABLE_MARKER_FILE: &str = "table.json";
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 const CURRENT_POINTER_FILE: &str = "current.json";
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 const LIFECYCLE_FILE: &str = "lifecycle.json";
 const METADATA_DIR: &str = "metadata";
 const DATA_DIR: &str = "data";

rustfs/src/table_catalog/model.rs

@@ -1076,6 +1076,10 @@ pub(crate) enum TableCatalogBackingKind {
 #[serde(rename_all = "SCREAMING_SNAKE_CASE")]
 pub(crate) enum TableCatalogAuthority {
     RustfsSysObject,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     LinearizableMetadataKv,
 }
 
@@ -1083,6 +1087,10 @@ pub(crate) enum TableCatalogAuthority {
 #[serde(rename_all = "SCREAMING_SNAKE_CASE")]
 pub(crate) enum TableCatalogConsistencyMode {
     ConditionalObjectCas,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     LinearizableCas,
 }
 
@@ -1090,6 +1098,10 @@ pub(crate) enum TableCatalogConsistencyMode {
 #[serde(rename_all = "SCREAMING_SNAKE_CASE")]
 pub(crate) enum TableCatalogDurabilityMode {
     StagedCommitLogBeforePointerUpdate,
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     WalBeforeStateMachineApply,
 }
 
@@ -1409,12 +1421,20 @@ pub(crate) struct TableCommitRecoveryReport {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize)]
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) struct NamespaceMarker {
     pub version: u16,
     pub namespace: String,
 }
 
 impl NamespaceMarker {
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn new(namespace: &Namespace) -> Self {
         Self {
             version: TABLE_NAMESPACE_MARKER_VERSION,
@@ -1423,11 +1443,19 @@ impl NamespaceMarker {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn namespace_marker_json(namespace: &Namespace) -> Result<Vec<u8>, serde_json::Error> {
     serde_json::to_vec(&NamespaceMarker::new(namespace))
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize)]
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) struct TableMarker {
     pub version: u16,
     pub namespace: String,
@@ -1436,6 +1464,10 @@ pub(crate) struct TableMarker {
 }
 
 impl TableMarker {
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn new(namespace: &Namespace, table: &IdentifierSegment) -> Self {
         Self {
             version: TABLE_RESOURCE_MARKER_VERSION,
@@ -1446,17 +1478,29 @@ impl TableMarker {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn table_marker_json(namespace: &Namespace, table: &IdentifierSegment) -> Result<Vec<u8>, serde_json::Error> {
     serde_json::to_vec(&TableMarker::new(namespace, table))
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) struct TableMetadataPointer {
     pub version: u16,
     pub metadata_location: String,
 }
 
 impl TableMetadataPointer {
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub fn new(metadata_location: String) -> Self {
         Self {
             version: TABLE_METADATA_POINTER_VERSION,
@@ -1465,10 +1509,18 @@ impl TableMetadataPointer {
     }
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn table_metadata_pointer_json(metadata_location: String) -> Result<Vec<u8>, serde_json::Error> {
     serde_json::to_vec(&TableMetadataPointer::new(metadata_location))
 }
 
+#[allow(
+    dead_code,
+    reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+)]
 pub(crate) fn parse_table_metadata_pointer(data: &[u8]) -> Result<TableMetadataPointer, serde_json::Error> {
     serde_json::from_slice(data)
 }

rustfs/src/table_catalog/store/mod.rs

@@ -164,6 +164,10 @@ pub(crate) trait TableCatalogStore: Send + Sync {
         ))
     }
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     async fn list_namespaces_page(
         &self,
         table_bucket: &str,
@@ -193,8 +197,16 @@ pub(crate) trait TableCatalogStore: Send + Sync {
 
     async fn drop_namespace(&self, table_bucket: &str, namespace: &str) -> TableCatalogStoreResult<()>;
 
+    #[allow(
+        dead_code,
+        reason = "declared trait method: implementors provide it but no caller dispatches through the trait yet (backlog#1823)"
+    )]
     async fn create_table(&self, entry: TableEntry) -> TableCatalogStoreResult<()>;
 
+    #[allow(
+        dead_code,
+        reason = "declared trait method: implementors provide it but no caller dispatches through the trait yet (backlog#1823)"
+    )]
     async fn register_table(&self, entry: TableEntry) -> TableCatalogStoreResult<()>;
 
     async fn register_table_with_publication(
@@ -250,6 +262,10 @@ pub(crate) trait TableCatalogStore: Send + Sync {
     ///
     /// Callers publishing client-supplied Iceberg metadata must validate its logical shape and the physical graph of
     /// newly introduced or changed snapshots before invoking this persistence boundary.
+    #[allow(
+        dead_code,
+        reason = "declared trait method: implementors provide it but no caller dispatches through the trait yet (backlog#1823)"
+    )]
     async fn commit_table(&self, request: TableCommitRequest) -> TableCatalogStoreResult<TableCommitResult>;
 
     async fn commit_table_with_publication(
@@ -495,6 +511,10 @@ pub(crate) struct TableCatalogLockGuard {
 }
 
 impl TableCatalogLockGuard {
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub(crate) fn stable(guard: impl Send + 'static) -> Self {
         Self {
             _guard: Box::new(guard),
@@ -615,6 +635,10 @@ pub(crate) trait TableCatalogObjectBackend: Clone + Send + Sync + 'static {
 
     async fn object_exists(&self, bucket: &str, object: &str) -> TableCatalogStoreResult<bool>;
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     async fn object_exists_unlocked(&self, bucket: &str, object: &str) -> TableCatalogStoreResult<bool> {
         self.object_exists(bucket, object).await
     }
@@ -1006,6 +1030,10 @@ where
         }
     }
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub(crate) fn backing_mode(&self) -> TableCatalogBackingMode {
         match self {
             Self::ObjectBacked(_) => TableCatalogBackingMode::ObjectBacked,
@@ -1529,6 +1557,10 @@ where
         }
     }
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub(crate) async fn get_external_catalog_bridge(
         &self,
         table_bucket: &str,
@@ -1541,6 +1573,10 @@ where
         }
     }
 
+    #[allow(
+        dead_code,
+        reason = "exercised by table_catalog/tests.rs; the lib target cannot see test-only consumers (backlog#1823)"
+    )]
     pub(crate) async fn put_external_catalog_bridge(
         &self,
         entry: ExternalCatalogBridgeEntry,