fix: use resenje multex (#4883)

pkg/storer/internal/reserve/reserve.go

@@ -25,27 +25,11 @@ import (
 	"github.com/ethersphere/bee/v2/pkg/swarm"
 	"github.com/ethersphere/bee/v2/pkg/topology"
 	"golang.org/x/sync/errgroup"
+	"resenje.org/multex"
 )
 
 const reserveScope = "reserve"
 
-type multexLock struct {
-	mul map[string]struct{}
-	mu  chan struct{}
-}
-
-func (m *multexLock) Lock(id string) {
-	m.mu <- struct{}{}
-	m.mul[id] = struct{}{}
-	<-m.mu
-}
-
-func (m *multexLock) Unlock(id string) {
-	m.mu <- struct{}{}
-	delete(m.mul, id)
-	<-m.mu
-}
-
 type Reserve struct {
 	baseAddr     swarm.Address
 	radiusSetter topology.SetStorageRadiuser
@@ -55,7 +39,7 @@ type Reserve struct {
 	size     atomic.Int64
 	radius   atomic.Uint32
 
-	multx multexLock
+	multx *multex.Multex
 	st    transaction.Storage
 }
 
@@ -73,7 +57,7 @@ func New(
 		capacity:     capacity,
 		radiusSetter: radiusSetter,
 		logger:       logger.WithName(reserveScope).Register(),
-		multx:        multexLock{mul: make(map[string]struct{}), mu: make(chan struct{}, 1)},
+		multx:        multex.New(),
 	}
 
 	err := st.Run(context.Background(), func(s transaction.Store) error {