diff --git a/cache.go b/cache.go
index 1131ddf3..efe2986c 100644
--- a/cache.go
+++ b/cache.go
@@ -101,7 +101,7 @@ func (a *adapter) Update(key, cmd string, val RedisMessage) (sxat int64) {
 			val.setExpireAt(sxat)
 		}
 		a.store.Set(key+cmd, val)
-		flight.set(val, nil)
+		flight.setVal(val)
 		entries[cmd] = nil
 	}
 	a.mu.Unlock()
@@ -112,7 +112,7 @@ func (a *adapter) Cancel(key, cmd string, err error) {
 	a.mu.Lock()
 	entries := a.flights[key]
 	if flight, ok := entries[cmd].(*adapterEntry); ok {
-		flight.set(RedisMessage{}, err)
+		flight.setErr(err)
 		entries[cmd] = nil
 	}
 	a.mu.Unlock()
@@ -154,7 +154,7 @@ func (a *adapter) Close(err error) {
 	for _, entries := range flights {
 		for _, e := range entries {
 			if e != nil {
-				e.(*adapterEntry).set(RedisMessage{}, err)
+				e.(*adapterEntry).setErr(err)
 			}
 		}
 	}
@@ -167,8 +167,13 @@ type adapterEntry struct {
 	xat int64
 }
 
-func (a *adapterEntry) set(val RedisMessage, err error) {
-	a.err, a.val = err, val
+func (a *adapterEntry) setVal(val RedisMessage) {
+	a.val = val
+	close(a.ch)
+}
+
+func (a *adapterEntry) setErr(err error) {
+	a.err = err
 	close(a.ch)
 }
 
@@ -202,27 +207,27 @@ type flatentry struct {
 func (f *flatentry) insert(e *flatentry) {
 	f.size += e.size
 	f.mu.Lock()
-	defer f.mu.Unlock()
 	e.ovfl = f.ovfl
 	f.ovfl = e
+	f.mu.Unlock()
 }
 
 func (f *flatentry) find(cmd string, ts int64) (ret RedisMessage, expired bool) {
-	if f == nil {
-		return
-	}
-	if ts >= f.ttl {
-		expired = true
-		return
-	}
-	if cmd == f.cmd {
-		_ = ret.CacheUnmarshalView(f.val)
-		return
+	for next := f; next != nil; {
+		if ts >= next.ttl {
+			expired = true
+			return
+		}
+		if cmd == next.cmd {
+			_ = ret.CacheUnmarshalView(next.val)
+			return
+		}
+		next.mu.RLock()
+		ovfl := next.ovfl
+		next.mu.RUnlock()
+		next = ovfl
 	}
-	f.mu.RLock()
-	ovfl := f.ovfl
-	f.mu.RUnlock()
-	return ovfl.find(cmd, ts)
+	return
 }
 
 const lrBatchSize = 64
@@ -246,7 +251,9 @@ func NewFlattenCache(limit int) CacheStore {
 	f.lrup = sync.Pool{New: func() any {
 		b := &lrBatch{m: make(map[*flatentry]struct{}, lrBatchSize)}
 		runtime.SetFinalizer(b, func(b *lrBatch) {
+			f.mu.Lock()
 			f.llTailBatch(b)
+			f.mu.Unlock()
 		})
 		return b
 	}}
@@ -287,11 +294,9 @@ func (f *flatten) llTail(e *flatentry) {
 }
 
 func (f *flatten) llTailBatch(b *lrBatch) {
-	f.mu.Lock()
 	for e := range b.m {
 		f.llTail(e)
 	}
-	f.mu.Unlock()
 	clear(b.m)
 }
 
@@ -310,7 +315,9 @@ func (f *flatten) Flight(key, cmd string, ttl time.Duration, now time.Time) (Red
 		batch := f.lrup.Get().(*lrBatch)
 		batch.m[e] = struct{}{}
 		if len(batch.m) == lrBatchSize {
+			f.mu.Lock()
 			f.llTailBatch(batch)
+			f.mu.Unlock()
 		}
 		f.lrup.Put(batch)
 		return v, nil
@@ -373,7 +380,7 @@ func (f *flatten) Update(key, cmd string, val RedisMessage) (sxat int64) {
 			}
 		}
 		f.mu.Unlock()
-		af.set(val, nil)
+		af.setVal(val)
 	}
 	return sxat
 }
@@ -384,7 +391,7 @@ func (f *flatten) Cancel(key, cmd string, err error) {
 	defer f.mu.Unlock()
 	if af := f.flights[fk]; af != nil {
 		delete(f.flights, fk)
-		af.set(RedisMessage{}, err)
+		af.setErr(err)
 	}
 }
 
@@ -416,6 +423,6 @@ func (f *flatten) Close(err error) {
 	f.mark++
 	f.mu.Unlock()
 	for _, entry := range flights {
-		entry.set(RedisMessage{}, err)
+		entry.setErr(err)
 	}
 }