Merge branch 'main' into reatang/iam-issue-analysis-d4fb97

The v4 runtime capabilities response carried no admin.iam.* entries, so
the rc client's capability gate rejected policy detach even though the
detach route is implemented (rustfs/backlog#1900). Advertise the IAM
admin capability set as a flat named list whose statuses are derived
from the public admin route inventory, so the advertisement tracks the
actually registered routes instead of a hardcoded claim.

crates/config/src/constants/runtime.rs

@@ -57,6 +57,13 @@ pub const DEFAULT_MAX_IO_EVENTS_PER_TICK: usize = 1024;
 pub const DEFAULT_EVENT_INTERVAL: u32 = 61;
 pub const DEFAULT_RNG_SEED: Option<u64> = None; // None means random
 
+/// Dedicated blocking thread pool for fsync/fdatasync operations.
+/// When > 1, fsync operations are isolated from the main blocking pool to
+/// prevent device-bound fsync from starving read operations (pread/stat/open).
+/// Default 0 means auto (no isolation, use main runtime).
+pub const ENV_FSYNC_BLOCKING_THREADS: &str = "RUSTFS_RUNTIME_FSYNC_BLOCKING_THREADS";
+pub const DEFAULT_FSYNC_BLOCKING_THREADS: usize = 0;
+
 // Dial9 Tokio Telemetry Default values
 pub const DEFAULT_RUNTIME_DIAL9_ENABLED: bool = false; // Disabled by default
 pub const DEFAULT_RUNTIME_DIAL9_OUTPUT_DIR: &str = "/var/log/rustfs/telemetry";

crates/ecstore/src/core/pools.rs

@@ -89,7 +89,6 @@ const DECOMMISSION_STAGE_SOURCE_CLEANUP: &str = "source_cleanup";
 const DECOMMISSION_STAGE_ENTRY_FINISHED: &str = "entry_finished";
 const DECOMMISSION_PROGRESS_SAVE_INTERVAL: Duration = Duration::seconds(30);
 const DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD: usize = 1000;
-const DECOMMISSION_PROGRESS_SAVE_RETRY_BACKOFF: Duration = Duration::seconds(1);
 const DECOMMISSION_BUCKET_CONCURRENCY_ENV: &str = "RUSTFS_DECOMMISSION_BUCKET_CONCURRENCY";
 const DECOMMISSION_BUCKET_CONCURRENCY_DEFAULT_CAP: usize = 4;
 const DECOMMISSION_TARGET_CAPACITY_OVERHEAD_PERCENT: usize = 30;
@@ -639,6 +638,22 @@ fn track_decommission_current_object(meta: &mut PoolMeta, idx: usize, bucket: &s
     track_decommission_current_object_stage(meta, idx, bucket, object, "")
 }
 
+fn touch_decommission_progress(meta: &mut PoolMeta, idx: usize) -> Result<()> {
+    let pool_count = meta.pools.len();
+    ensure_valid_decommission_pool_index(pool_count, idx)?;
+
+    let Some(pool) = meta.pools.get_mut(idx) else {
+        return Err(invalid_decommission_pool_index_error(pool_count, idx));
+    };
+    let Some(info) = pool.decommission.as_mut() else {
+        return Err(decommission_metadata_not_initialized_error("touch decommission progress"));
+    };
+
+    pool.last_update = OffsetDateTime::now_utc();
+    info.mark_progress_saved();
+    Ok(())
+}
+
 fn resolve_decommission_update_after_result(result: Result<bool>) -> Result<bool> {
     result.map_err(|err| Error::other(format!("decommission metadata update failed: {err}")))
 }
@@ -1468,7 +1483,6 @@ impl TryFrom<PersistedPoolDecommissionInfo> for PoolDecommissionInfo {
             terminal_reload_attempt_at: value.terminal_reload_attempt_at,
             terminal_reload_failures: value.terminal_reload_failures,
             progress_save_item_baseline: value.items_decommissioned.saturating_add(value.items_decommission_failed),
-            progress_save_retry_after: None,
         })
     }
 }
@@ -1500,7 +1514,6 @@ impl TryFrom<LegacyPoolDecommissionInfo> for PoolDecommissionInfo {
             terminal_reload_attempt_at: None,
             terminal_reload_failures: Vec::new(),
             progress_save_item_baseline: value.items_decommissioned.saturating_add(value.items_decommission_failed),
-            progress_save_retry_after: None,
         })
     }
 }
@@ -1614,82 +1627,6 @@ impl PoolMeta {
         }
     }
 
-    fn decommission_progress_checkpoint(
-        &self,
-        idx: usize,
-        duration: Duration,
-        now: OffsetDateTime,
-    ) -> Result<Option<DecommissionProgressCheckpoint>> {
-        let pool_count = self.pools.len();
-        ensure_valid_decommission_pool_index(pool_count, idx)?;
-
-        let Some(pool) = self.pools.get(idx) else {
-            return Err(invalid_decommission_pool_index_error(pool_count, idx));
-        };
-        let Some(info) = pool.decommission.as_ref() else {
-            return Err(decommission_metadata_not_initialized_error("update decommission metadata timestamp"));
-        };
-
-        if info.progress_save_retry_after.is_some_and(|retry_after| now < retry_after) {
-            return Ok(None);
-        }
-
-        let time_threshold_reached = now.unix_timestamp() - pool.last_update.unix_timestamp() >= duration.whole_seconds();
-        let item_threshold_reached = info.items_since_last_progress_save() >= DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD;
-        if !time_threshold_reached && !item_threshold_reached {
-            return Ok(None);
-        }
-
-        Ok(Some(DecommissionProgressCheckpoint {
-            start_time: info.start_time,
-            queued: info.queued,
-            counted_items: info.counted_items(),
-            checkpoint_at: now,
-        }))
-    }
-
-    fn commit_decommission_progress_checkpoint(&mut self, idx: usize, checkpoint: DecommissionProgressCheckpoint) -> bool {
-        let Some(pool) = self.pools.get_mut(idx) else {
-            return false;
-        };
-        let Some(info) = pool.decommission.as_mut() else {
-            return false;
-        };
-
-        if info.start_time != checkpoint.start_time
-            || info.queued != checkpoint.queued
-            || !is_decommission_active(info.complete, info.failed, info.canceled)
-        {
-            return false;
-        }
-
-        info.progress_save_item_baseline = info.progress_save_item_baseline.max(checkpoint.counted_items);
-        info.progress_save_retry_after = None;
-        pool.last_update = pool.last_update.max(checkpoint.checkpoint_at);
-        true
-    }
-
-    fn defer_decommission_progress_checkpoint(
-        &mut self,
-        idx: usize,
-        checkpoint: DecommissionProgressCheckpoint,
-        retry_after: OffsetDateTime,
-    ) {
-        let Some(pool) = self.pools.get_mut(idx) else {
-            return;
-        };
-        let Some(info) = pool.decommission.as_mut() else {
-            return;
-        };
-
-        if info.start_time == checkpoint.start_time
-            && info.queued == checkpoint.queued
-            && is_decommission_active(info.complete, info.failed, info.canceled)
-        {
-            info.progress_save_retry_after = Some(retry_after);
-        }
-    }
-
     fn load_from_config_data(&mut self, data: Vec<u8>) -> Result<()> {
         if data.is_empty() {
             return Ok(());
@@ -2050,9 +1987,30 @@ impl PoolMeta {
     }
 
     pub fn update_after(&mut self, idx: usize, duration: Duration) -> Result<bool> {
-        Ok(self
-            .decommission_progress_checkpoint(idx, duration, OffsetDateTime::now_utc())?
-            .is_some())
+        let pool_count = self.pools.len();
+        ensure_valid_decommission_pool_index(pool_count, idx)?;
+
+        let (last_update, item_threshold_reached) = match self.pools.get(idx) {
+            Some(pool) if let Some(info) = pool.decommission.as_ref() => (
+                pool.last_update,
+                info.items_since_last_progress_save() >= DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD,
+            ),
+            Some(_) => {
+                return Err(decommission_metadata_not_initialized_error("update decommission metadata timestamp"));
+            }
+            None => return Err(invalid_decommission_pool_index_error(pool_count, idx)),
+        };
+        let now = OffsetDateTime::now_utc();
+
+        if now.unix_timestamp() - last_update.unix_timestamp() >= duration.whole_seconds() || item_threshold_reached {
+            let Some(pool) = self.pools.get_mut(idx) else {
+                return Err(invalid_decommission_pool_index_error(pool_count, idx));
+            };
+            pool.last_update = now;
+            return Ok(true);
+        }
+
+        Ok(false)
     }
 
     pub fn validate(&self, pools: Vec<Arc<Sets>>) -> Result<bool> {
@@ -2193,16 +2151,6 @@ pub struct PoolDecommissionInfo {
     pub terminal_reload_failures: Vec<String>,
     #[serde(skip)]
     pub progress_save_item_baseline: usize,
-    #[serde(skip)]
-    pub progress_save_retry_after: Option<OffsetDateTime>,
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-struct DecommissionProgressCheckpoint {
-    start_time: Option<OffsetDateTime>,
-    queued: bool,
-    counted_items: usize,
-    checkpoint_at: OffsetDateTime,
 }
 
 impl PoolDecommissionInfo {
@@ -2237,7 +2185,6 @@ impl PoolDecommissionInfo {
 
     fn mark_progress_saved(&mut self) {
         self.progress_save_item_baseline = self.counted_items();
-        self.progress_save_retry_after = None;
     }
 
     pub fn bucket_push(&mut self, bucket: &DecomBucketInfo) {
@@ -2542,40 +2489,6 @@ impl ECStore {
         snapshot.save(self.pools.clone()).await
     }
 
-    async fn save_decommission_progress_checkpoint(&self, idx: usize) -> Result<bool> {
-        // Lock order: save gate, then the short pool metadata read/write sections. Peer
-        // reloads are intentionally performed by the caller after both locks are released.
-        let _save_guard = self.pool_meta_save_gate.lock().await;
-        let (snapshot, checkpoint) = {
-            let pool_meta = self.pool_meta.read().await;
-            let Some(checkpoint) = pool_meta.decommission_progress_checkpoint(
-                idx,
-                DECOMMISSION_PROGRESS_SAVE_INTERVAL,
-                OffsetDateTime::now_utc(),
-            )?
-            else {
-                return Ok(false);
-            };
-
-            let mut snapshot = pool_meta.clone();
-            let Some(pool) = snapshot.pools.get_mut(idx) else {
-                return Err(invalid_decommission_pool_index_error(snapshot.pools.len(), idx));
-            };
-            pool.last_update = checkpoint.checkpoint_at;
-            (snapshot, checkpoint)
-        };
-
-        if let Err(err) = snapshot.save(self.pools.clone()).await {
-            let retry_after = OffsetDateTime::now_utc() + DECOMMISSION_PROGRESS_SAVE_RETRY_BACKOFF;
-            let mut pool_meta = self.pool_meta.write().await;
-            pool_meta.defer_decommission_progress_checkpoint(idx, checkpoint, retry_after);
-            return Err(err);
-        }
-
-        let mut pool_meta = self.pool_meta.write().await;
-        Ok(pool_meta.commit_decommission_progress_checkpoint(idx, checkpoint))
-    }
-
     async fn save_current_pool_meta_for_decommission_start(
         &self,
         indices: &[usize],
@@ -2958,7 +2871,7 @@ impl ECStore {
         Ok(())
     }
 
-    async fn track_decommission_entry_progress_stage(
+    async fn save_decommission_entry_progress_stage(
         &self,
         idx: usize,
         bucket: &str,
@@ -2969,6 +2882,22 @@ impl ECStore {
             let mut pool_meta = self.pool_meta.write().await;
             track_decommission_current_object_stage(&mut pool_meta, idx, bucket, object, stage)
                 .map_err(|err| with_decommission_entry_context(stage, bucket, object, err))?;
+            touch_decommission_progress(&mut pool_meta, idx)
+                .map_err(|err| with_decommission_entry_context(stage, bucket, object, err))?;
+        }
+
+        if let Some(err) = resolve_decommission_progress_save_result(self.save_current_pool_meta().await) {
+            warn!(
+                event = EVENT_DECOMMISSION_ENTRY,
+                component = LOG_COMPONENT_ECSTORE,
+                subsystem = LOG_SUBSYSTEM_POOLS,
+                pool_index = idx,
+                bucket = %bucket,
+                object = %object,
+                stage,
+                error = ?err,
+                "Decommission progress stage save failed"
+            );
         }
 
         Ok(())
@@ -3236,7 +3165,7 @@ impl ECStore {
                 let bucket_name = bucket.clone();
                 let object_name = rd.object_info.name.clone();
 
-                self.track_decommission_entry_progress_stage(
+                self.save_decommission_entry_progress_stage(
                     idx,
                     bucket_name.as_str(),
                     object_name.as_str(),
@@ -3330,7 +3259,7 @@ impl ECStore {
             }
             decommission_cancel_signal_result(rx.is_cancelled())?;
 
-            self.track_decommission_entry_progress_stage(
+            self.save_decommission_entry_progress_stage(
                 idx,
                 bucket.as_str(),
                 entry.name.as_str(),
@@ -3338,7 +3267,7 @@ impl ECStore {
             )
             .await?;
 
-            self.track_decommission_entry_progress_stage(
+            self.save_decommission_entry_progress_stage(
                 idx,
                 bucket.as_str(),
                 entry.name.as_str(),
@@ -3405,42 +3334,34 @@ impl ECStore {
             }
         };
 
-        self.track_decommission_entry_progress_stage(
-            idx,
-            bucket.as_str(),
-            entry.name.as_str(),
-            DECOMMISSION_STAGE_ENTRY_FINISHED,
-        )
-        .await?;
+        self.save_decommission_entry_progress_stage(idx, bucket.as_str(), entry.name.as_str(), DECOMMISSION_STAGE_ENTRY_FINISHED)
+            .await?;
 
         if should_save_progress {
-            match self.save_decommission_progress_checkpoint(idx).await {
-                Ok(true) => {
-                    if let Some(notification_sys) = runtime_sources::notification_sys()
-                        && let Err(err) = resolve_decommission_entry_reload_result(
-                            notification_sys.reload_pool_meta().await,
-                            bucket.as_str(),
-                            entry.name.as_str(),
-                        )
-                    {
-                        warn!("{err}");
-                    }
-                }
-                Ok(false) => {}
-                Err(err) => {
-                    if let Some(err) = resolve_decommission_progress_save_result(Err(err)) {
-                        warn!(
-                            event = EVENT_DECOMMISSION_ENTRY,
-                            component = LOG_COMPONENT_ECSTORE,
-                            subsystem = LOG_SUBSYSTEM_POOLS,
-                            pool_index = idx,
-                            bucket = %bucket,
-                            object = %entry.name,
-                            state = "progress_save_failed",
-                            error = %err,
-                            "Decommission progress save failed; continuing and will retry at the next checkpoint"
-                        );
-                    }
+            let save_result = self.save_current_pool_meta().await;
+            if let Some(err) = resolve_decommission_progress_save_result(save_result) {
+                warn!(
+                    event = EVENT_DECOMMISSION_ENTRY,
+                    component = LOG_COMPONENT_ECSTORE,
+                    subsystem = LOG_SUBSYSTEM_POOLS,
+                    pool_index = idx,
+                    bucket = %bucket,
+                    object = %entry.name,
+                    state = "progress_save_failed",
+                    error = %err,
+                    "Decommission progress save failed; continuing and will retry at the next checkpoint"
+                );
+            } else {
+                let mut pool_meta = self.pool_meta.write().await;
+                pool_meta.mark_decommission_progress_saved();
+                if let Some(notification_sys) = runtime_sources::notification_sys()
+                    && let Err(err) = resolve_decommission_entry_reload_result(
+                        notification_sys.reload_pool_meta().await,
+                        bucket.as_str(),
+                        entry.name.as_str(),
+                    )
+                {
+                    warn!("{err}");
                 }
             }
         }
@@ -5343,11 +5264,11 @@ pub(crate) fn fallback_free_capacity_dedup(disks: &[rustfs_madmin::Disk]) -> usi
 #[cfg(test)]
 mod pools_tests {
     use super::{
-        DECOMMISSION_PROGRESS_SAVE_INTERVAL, DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD, DECOMMISSION_PROGRESS_SAVE_RETRY_BACKOFF,
-        DecomBucketInfo, DecommissionStartPoolState, DecommissionTerminalState, ListCallback, PoolDecommissionInfo, PoolMeta,
-        PoolSpaceInfo, PoolStatus, apply_decommission_status_space_info, bind_decommission_cancelers,
-        bind_missing_decommission_cancelers, cancel_decommission_canceler, classify_decommission_terminal_state,
-        count_decommission_item, decommission_cancel_signal_result, decommission_item_size, decommission_meta_bucket_options,
+        DECOMMISSION_PROGRESS_SAVE_INTERVAL, DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD, DecomBucketInfo,
+        DecommissionStartPoolState, DecommissionTerminalState, ListCallback, PoolDecommissionInfo, PoolMeta, PoolSpaceInfo,
+        PoolStatus, apply_decommission_status_space_info, bind_decommission_cancelers, bind_missing_decommission_cancelers,
+        cancel_decommission_canceler, classify_decommission_terminal_state, count_decommission_item,
+        decommission_cancel_signal_result, decommission_item_size, decommission_meta_bucket_options,
         decommission_start_pool_state, dedup_indices, default_decommission_bucket_concurrency,
         ensure_decommission_cancel_allowed, ensure_decommission_clear_allowed, ensure_decommission_listing_disks_available,
         ensure_decommission_not_rebalancing, ensure_decommission_start_allowed, ensure_decommission_start_keeps_active_pool,
@@ -5372,8 +5293,9 @@ mod pools_tests {
         should_preserve_decommission_canceled_state, should_reject_decommission_cancel_as_terminal,
         should_retry_decommission_cancel_reload, should_retry_decommission_listing, should_skip_canceled_decommission_routine,
         split_decommission_buckets, take_and_cancel_decommission_canceler, take_decommission_canceler,
-        track_decommission_current_object, track_decommission_current_object_stage, validate_start_decommission_request,
-        wait_decommission_listing_retry, wait_decommission_worker_drain, with_decommission_entry_context,
+        touch_decommission_progress, track_decommission_current_object, track_decommission_current_object_stage,
+        validate_start_decommission_request, wait_decommission_listing_retry, wait_decommission_worker_drain,
+        with_decommission_entry_context,
     };
     use crate::data_movement;
     use crate::disk::endpoint::Endpoint;
@@ -6616,7 +6538,7 @@ mod pools_tests {
     }
 
     #[test]
-    fn test_track_decommission_stage_does_not_advance_checkpoint_state() {
+    fn test_touch_decommission_progress_updates_last_update_and_save_baseline() {
         let mut meta = PoolMeta {
             pools: vec![PoolStatus {
                 id: 0,
@@ -6631,13 +6553,11 @@ mod pools_tests {
             ..Default::default()
         };
 
-        track_decommission_current_object_stage(&mut meta, 0, "bucket", "object", "migrate_object")
-            .expect("valid decommission progress should be tracked");
+        touch_decommission_progress(&mut meta, 0).expect("valid decommission progress should be touched");
 
-        assert_eq!(meta.pools[0].last_update, OffsetDateTime::UNIX_EPOCH);
+        assert!(meta.pools[0].last_update > OffsetDateTime::UNIX_EPOCH);
         let info = meta.pools[0].decommission.as_ref().expect("decommission info should exist");
-        assert_eq!(info.items_since_last_progress_save(), 5);
-        assert_eq!(info.stage, "migrate_object");
+        assert_eq!(info.items_since_last_progress_save(), 0);
     }
 
     #[test]
@@ -6712,134 +6632,6 @@ mod pools_tests {
         assert_eq!(info.items_since_last_progress_save(), 1);
     }
 
-    #[test]
-    fn test_pool_meta_update_after_does_not_advance_last_update_before_save() {
-        let last_update = OffsetDateTime::UNIX_EPOCH;
-        let mut meta = PoolMeta {
-            pools: vec![PoolStatus {
-                id: 0,
-                cmd_line: "pool-0".to_string(),
-                last_update,
-                decommission: Some(PoolDecommissionInfo {
-                    start_time: Some(last_update),
-                    items_decommissioned: DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD,
-                    ..Default::default()
-                }),
-            }],
-            ..Default::default()
-        };
-
-        assert!(
-            meta.update_after(0, DECOMMISSION_PROGRESS_SAVE_INTERVAL)
-                .expect("item threshold should request a checkpoint")
-        );
-        assert_eq!(meta.pools[0].last_update, last_update);
-    }
-
-    #[test]
-    fn test_decommission_progress_checkpoint_commits_exact_snapshot_watermark() {
-        let start_time = OffsetDateTime::UNIX_EPOCH;
-        let checkpoint_at = start_time + Duration::seconds(30);
-        let mut meta = PoolMeta {
-            pools: vec![PoolStatus {
-                id: 0,
-                cmd_line: "pool-0".to_string(),
-                last_update: start_time,
-                decommission: Some(PoolDecommissionInfo {
-                    start_time: Some(start_time),
-                    items_decommissioned: DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD,
-                    ..Default::default()
-                }),
-            }],
-            ..Default::default()
-        };
-
-        let checkpoint = meta
-            .decommission_progress_checkpoint(0, DECOMMISSION_PROGRESS_SAVE_INTERVAL, checkpoint_at)
-            .expect("valid decommission state should produce a checkpoint")
-            .expect("item threshold should produce a checkpoint");
-        meta.count_item(0, 1, false);
-
-        assert!(meta.commit_decommission_progress_checkpoint(0, checkpoint));
-        let info = meta.pools[0].decommission.as_ref().expect("decommission info should exist");
-        assert_eq!(info.progress_save_item_baseline, checkpoint.counted_items);
-        assert_eq!(info.items_since_last_progress_save(), 1);
-        assert_eq!(meta.pools[0].last_update, checkpoint_at);
-    }
-
-    #[test]
-    fn test_decommission_progress_checkpoint_backoff_does_not_advance_baseline() {
-        let start_time = OffsetDateTime::UNIX_EPOCH;
-        let checkpoint_at = start_time + Duration::seconds(30);
-        let retry_after = checkpoint_at + DECOMMISSION_PROGRESS_SAVE_RETRY_BACKOFF;
-        let mut meta = PoolMeta {
-            pools: vec![PoolStatus {
-                id: 0,
-                cmd_line: "pool-0".to_string(),
-                last_update: start_time,
-                decommission: Some(PoolDecommissionInfo {
-                    start_time: Some(start_time),
-                    items_decommissioned: DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD,
-                    ..Default::default()
-                }),
-            }],
-            ..Default::default()
-        };
-
-        let checkpoint = meta
-            .decommission_progress_checkpoint(0, DECOMMISSION_PROGRESS_SAVE_INTERVAL, checkpoint_at)
-            .expect("valid decommission state should produce a checkpoint")
-            .expect("item threshold should produce a checkpoint");
-        meta.defer_decommission_progress_checkpoint(0, checkpoint, retry_after);
-
-        assert!(
-            meta.decommission_progress_checkpoint(0, DECOMMISSION_PROGRESS_SAVE_INTERVAL, checkpoint_at)
-                .expect("retry backoff check should succeed")
-                .is_none()
-        );
-        assert_eq!(meta.pools[0].last_update, start_time);
-        assert_eq!(
-            meta.pools[0]
-                .decommission
-                .as_ref()
-                .expect("decommission info should exist")
-                .progress_save_item_baseline,
-            0
-        );
-    }
-
-    #[test]
-    fn test_decommission_progress_checkpoint_count_scales_with_threshold() {
-        let start_time = OffsetDateTime::UNIX_EPOCH;
-        let checkpoint_at = start_time;
-        let mut meta = PoolMeta {
-            pools: vec![PoolStatus {
-                id: 0,
-                cmd_line: "pool-0".to_string(),
-                last_update: start_time,
-                decommission: Some(PoolDecommissionInfo {
-                    start_time: Some(start_time),
-                    ..Default::default()
-                }),
-            }],
-            ..Default::default()
-        };
-        let mut checkpoint_count = 0;
-
-        for _ in 0..(DECOMMISSION_PROGRESS_SAVE_ITEM_THRESHOLD * 10) {
-            meta.count_item(0, 1, false);
-            if let Some(checkpoint) = meta
-                .decommission_progress_checkpoint(0, DECOMMISSION_PROGRESS_SAVE_INTERVAL, checkpoint_at)
-                .expect("valid decommission state should produce a checkpoint")
-            {
-                checkpoint_count += 1;
-                assert!(meta.commit_decommission_progress_checkpoint(0, checkpoint));
-            }
-        }
-
-        assert_eq!(checkpoint_count, 10);
-    }
-
     #[test]
     fn test_ensure_decommission_not_rebalancing_rejects_running_rebalance() {
         let err = ensure_decommission_not_rebalancing(true).expect_err("rebalance running should be rejected");

crates/ecstore/src/disk/os.rs

@@ -315,7 +315,7 @@ pub async fn fsync_dir(dir: impl AsRef<Path>) -> io::Result<()> {
     #[cfg(unix)]
     {
         let dir = dir.as_ref().to_path_buf();
-        tokio::task::spawn_blocking(move || fsync_dir_std(dir)).await?
+        fsync_spawn_blocking(move || fsync_dir_std(dir)).await?
     }
 
     #[cfg(not(unix))]
@@ -683,7 +683,7 @@ async fn fsync_open_dst_dir_group(group: &DstDirFsyncGroup) -> io::Result<()> {
     #[cfg(test)]
     let dir = group.dir.clone();
     let dir_file = group.dir_file.clone();
-    tokio::task::spawn_blocking(move || {
+    fsync_spawn_blocking(move || {
         #[cfg(test)]
         {
             if let Some(kind) = fsync_dir_recorder::take_grouped_failure(&dir) {
@@ -1080,6 +1080,44 @@ const TEST_GLOBAL_FILE_SYNCS: usize = 64;
 
 static FILE_SYNC_PERMITS: LazyLock<Semaphore> = LazyLock::new(|| Semaphore::new(global_file_sync_limit()));
 static DISK_FILE_SYNC_LIMITERS: LazyLock<Mutex<HashMap<PathBuf, Weak<Semaphore>>>> = LazyLock::new(|| Mutex::new(HashMap::new()));
+
+/// Dedicated tokio runtime for fsync/fdatasync blocking operations. When
+/// configured with >1 threads, isolates device-bound fsync from the main
+/// blocking pool so reads (pread/stat/open) are not starved. `None` means
+/// fall back to the main runtime (zero behavior change).
+static FSYNC_RUNTIME: LazyLock<Option<tokio::runtime::Runtime>> = LazyLock::new(|| {
+    let threads =
+        rustfs_utils::get_env_usize(rustfs_config::ENV_FSYNC_BLOCKING_THREADS, rustfs_config::DEFAULT_FSYNC_BLOCKING_THREADS);
+    if threads <= 1 {
+        return None;
+    }
+    let mut builder = tokio::runtime::Builder::new_multi_thread();
+    builder
+        .worker_threads(num_cpus::get().min(8))
+        .max_blocking_threads(threads)
+        .thread_name("rustfs-fsync")
+        .thread_stack_size(512 * 1024)
+        .enable_all();
+    match builder.build() {
+        Ok(rt) => {
+            tracing::info!(threads, "fsync dedicated blocking pool enabled");
+            Some(rt)
+        }
+        Err(err) => {
+            tracing::warn!(%err, "failed to build fsync runtime, falling back to main pool");
+            None
+        }
+    }
+});
+
+/// Spawn a blocking task on the fsync-dedicated runtime if configured,
+/// otherwise fall back to the main tokio blocking pool.
+fn fsync_spawn_blocking<T: Send + 'static>(f: impl FnOnce() -> T + Send + 'static) -> tokio::task::JoinHandle<T> {
+    match FSYNC_RUNTIME.as_ref() {
+        Some(rt) => rt.spawn_blocking(f),
+        None => tokio::task::spawn_blocking(f),
+    }
+}
 static DISK_VOLUME_MUTATION_LOCKS: LazyLock<Mutex<HashMap<PathBuf, Weak<RwLock<()>>>>> =
     LazyLock::new(|| Mutex::new(HashMap::new()));
 type NamespaceMutationLock = AsyncMutex<()>;
@@ -1217,7 +1255,7 @@ where
     F: FnOnce() -> io::Result<T> + Send + 'static,
 {
     let (disk_permit, global_permit) = acquire_file_sync_permits(disk_permits).await?;
-    let result = tokio::task::spawn_blocking(move || {
+    let result = fsync_spawn_blocking(move || {
         let _disk_permit = disk_permit;
         work()
     })
@@ -2146,7 +2184,7 @@ async fn run_blocking_namespace_file_sync_operation_with_global<T: Send + 'stati
         wait_started,
     );
     let disk_permit = admission.disk_permit.clone();
-    let result = tokio::task::spawn_blocking(move || {
+    let result = fsync_spawn_blocking(move || {
         let _lease = lease;
         let _disk_permit = disk_permit;
         operation()

rustfs/src/admin/handlers/system.rs

@@ -70,6 +70,12 @@ const SITE_REPLICATION_EDIT_ROUTE: &str = "/rustfs/admin/v3/site-replication/edi
 const SITE_REPLICATION_RESYNC_ROUTE: &str = "/rustfs/admin/v3/site-replication/resync/op";
 const SITE_REPLICATION_REPAIR_ROUTE: &str = "/rustfs/admin/v3/site-replication/repair";
 const SITE_REPLICATION_REPAIR_STATUS_ROUTE: &str = "/rustfs/admin/v3/site-replication/repair/status";
+const IAM_POLICY_ATTACH_ROUTE: &str = "/rustfs/admin/v3/idp/builtin/policy/attach";
+const IAM_POLICY_DETACH_ROUTE: &str = "/rustfs/admin/v3/idp/builtin/policy/detach";
+const IAM_POLICY_ENTITIES_ROUTE: &str = "/rustfs/admin/v3/idp/builtin/policy-entities";
+const IAM_ACCESS_KEYS_BULK_ROUTE: &str = "/rustfs/admin/v3/list-access-keys-bulk";
+const IAM_ACCESS_KEYS_BULK_LDAP_ROUTE: &str = "/rustfs/admin/v3/idp/ldap/list-access-keys-bulk";
+const IAM_ACCESS_KEYS_BULK_OPENID_ROUTE: &str = "/rustfs/admin/v3/idp/openid/list-access-keys-bulk";
 
 macro_rules! log_system_request_rejected {
     ($operation:expr, $reason:expr) => {
@@ -661,9 +667,24 @@ pub struct RuntimeCapabilitiesSummary {
     pub manual_transition_jobs: CapabilityStatus,
 }
 
+/// One named admin capability advertised to management clients
+/// (rustfs/backlog#1900). `name` is a cross-repo wire contract: the rc
+/// client gates commands on these exact strings (see rustfs/cli
+/// `IAM_POLICY_DETACH_CAPABILITY` etc.), so entries may be added but
+/// existing names must never be renamed or removed.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
+pub struct AdvertisedAdminCapability {
+    pub name: &'static str,
+    pub status: CapabilityStatus,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize)]
 pub struct RuntimeCapabilitiesResponse {
     pub summary: RuntimeCapabilitiesSummary,
+    /// Additive field: absent in responses from older servers, so clients
+    /// must treat a missing list as "no dynamic advertisement" and fall
+    /// back to their pinned per-version contract.
+    pub advertised: Vec<AdvertisedAdminCapability>,
     pub replication: ReplicationCapabilities,
     pub manual_transition_jobs: ManualTransitionJobCapabilities,
     pub diagnostic_probes: DiagnosticProbeCapabilities,
@@ -986,6 +1007,7 @@ pub(crate) async fn build_runtime_capabilities_response()
 
     Ok(RuntimeCapabilitiesResponse {
         summary,
+        advertised: advertised_admin_capabilities(),
         replication: ReplicationCapabilities::current(),
         manual_transition_jobs: ManualTransitionJobCapabilities::current(),
         diagnostic_probes: DiagnosticProbeCapabilities::current(),
@@ -1077,6 +1099,23 @@ fn admin_route_capability(method: HttpMethod, path: &str) -> CapabilityStatus {
     admin_route_capability_from_inventory(method, path, ADMIN_ROUTE_POLICY_SPECS, DEFERRED_ADMIN_ROUTE_POLICIES)
 }
 
+fn advertised_admin_capabilities() -> Vec<AdvertisedAdminCapability> {
+    [
+        ("admin.iam.policy-attach", HttpMethod::Post, IAM_POLICY_ATTACH_ROUTE),
+        ("admin.iam.policy-detach", HttpMethod::Post, IAM_POLICY_DETACH_ROUTE),
+        ("admin.iam.policy-entities", HttpMethod::Get, IAM_POLICY_ENTITIES_ROUTE),
+        ("admin.iam.access-keys-bulk", HttpMethod::Get, IAM_ACCESS_KEYS_BULK_ROUTE),
+        ("admin.iam.access-keys-bulk.ldap", HttpMethod::Get, IAM_ACCESS_KEYS_BULK_LDAP_ROUTE),
+        ("admin.iam.access-keys-bulk.openid", HttpMethod::Get, IAM_ACCESS_KEYS_BULK_OPENID_ROUTE),
+    ]
+    .into_iter()
+    .map(|(name, method, route)| AdvertisedAdminCapability {
+        name,
+        status: admin_route_capability(method, route),
+    })
+    .collect()
+}
+
 fn admin_route_capability_from_inventory(
     method: HttpMethod,
     path: &str,
@@ -1239,6 +1278,48 @@ mod tests {
         );
     }
 
+    /// Wire-contract pin (rustfs/backlog#1900): the rc client keys its
+    /// command gates on these exact capability names, and parses each
+    /// entry as `{name, status: {state, reason?}}`. Renaming or dropping
+    /// a name silently disables the corresponding rc command.
+    #[tokio::test]
+    async fn runtime_capabilities_response_advertises_iam_capabilities() {
+        let response = build_runtime_capabilities_response()
+            .await
+            .expect("runtime capabilities response should build");
+
+        let expected_supported = [
+            "admin.iam.policy-attach",
+            "admin.iam.policy-detach",
+            "admin.iam.policy-entities",
+            "admin.iam.access-keys-bulk",
+            "admin.iam.access-keys-bulk.ldap",
+            "admin.iam.access-keys-bulk.openid",
+        ];
+        for name in expected_supported {
+            let entry = response
+                .advertised
+                .iter()
+                .find(|capability| capability.name == name)
+                .unwrap_or_else(|| panic!("{name} must be advertised"));
+            assert_eq!(entry.status.state, CapabilityState::Supported, "{name} must be supported");
+        }
+
+        let mut names: Vec<&str> = response.advertised.iter().map(|capability| capability.name).collect();
+        let total = names.len();
+        names.sort_unstable();
+        names.dedup();
+        assert_eq!(names.len(), total, "advertised capability names must be unique");
+
+        let serialized = serde_json::to_value(&response).expect("response should serialize");
+        let advertised = serialized["advertised"].as_array().expect("advertised must be an array");
+        let detach = advertised
+            .iter()
+            .find(|entry| entry["name"] == "admin.iam.policy-detach")
+            .expect("serialized detach entry must exist");
+        assert_eq!(detach["status"]["state"], "supported");
+    }
+
     #[tokio::test]
     async fn runtime_capabilities_response_reports_missing_topology_before_storage_init() {
         let response = build_runtime_capabilities_response()