diff --git a/server/go.mod b/server/go.mod
index f3f1d3f..c8ecdb1 100644
--- a/server/go.mod
+++ b/server/go.mod
@@ -2,9 +2,7 @@ module server
 
 go 1.17
 
-replace (
-	github.com/anacrolix/dms v1.2.2 => github.com/yourok/dms v0.0.0-20210826085116-42eca44e0aef
-)
+replace github.com/anacrolix/dms v1.2.2 => github.com/yourok/dms v0.0.0-20210826085116-42eca44e0aef
 
 exclude github.com/willf/bitset v1.2.0
 
@@ -29,7 +27,9 @@ require (
 	github.com/anacrolix/chansync v0.1.0 // indirect
 	github.com/anacrolix/confluence v1.8.0 // indirect
 	github.com/anacrolix/dht/v2 v2.10.3 // indirect
+	github.com/anacrolix/envpprof v1.1.1 // indirect
 	github.com/anacrolix/ffprobe v1.0.0 // indirect
+	github.com/anacrolix/go-libutp v1.0.4 // indirect
 	github.com/anacrolix/log v0.9.0 // indirect
 	github.com/anacrolix/missinggo/perf v1.0.0 // indirect
 	github.com/anacrolix/missinggo/v2 v2.5.2 // indirect
diff --git a/server/torr/apihelper.go b/server/torr/apihelper.go
index 773b609..4021475 100644
--- a/server/torr/apihelper.go
+++ b/server/torr/apihelper.go
@@ -6,7 +6,6 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
-	"sync"
 	"time"
 
 	"github.com/anacrolix/torrent"
@@ -17,8 +16,7 @@ import (
 )
 
 var (
-	bts     *BTServer
-	lockApi sync.Mutex
+	bts *BTServer
 )
 
 func InitApiHelper(bt *BTServer) {
@@ -26,8 +24,6 @@ func InitApiHelper(bt *BTServer) {
 }
 
 func LoadTorrent(tor *Torrent) *Torrent {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	if tor.TorrentSpec == nil {
 		return nil
 	}
@@ -45,8 +41,6 @@ func LoadTorrent(tor *Torrent) *Torrent {
 }
 
 func AddTorrent(spec *torrent.TorrentSpec, title, poster string, data string) (*Torrent, error) {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	torr, err := NewTorrent(spec, bts)
 	if err != nil {
 		log.TLogln("error add torrent:", err)
@@ -86,8 +80,6 @@ func SaveTorrentToDB(torr *Torrent) {
 }
 
 func GetTorrent(hashHex string) *Torrent {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	hash := metainfo.NewHashFromHex(hashHex)
 	tor := bts.GetTorrent(hash)
 	if tor != nil {
@@ -99,8 +91,6 @@ func GetTorrent(hashHex string) *Torrent {
 	if tr != nil {
 		tor = tr
 		go func() {
-			lockApi.Lock()
-			defer lockApi.Unlock()
 			log.TLogln("New torrent", tor.Hash())
 			tr, _ := NewTorrent(tor.TorrentSpec, bts)
 			if tr != nil {
@@ -117,9 +107,6 @@ func GetTorrent(hashHex string) *Torrent {
 }
 
 func SetTorrent(hashHex, title, poster, data string) *Torrent {
-	lockApi.Lock()
-	defer lockApi.Unlock()
-
 	hash := metainfo.NewHashFromHex(hashHex)
 	torr := bts.GetTorrent(hash)
 	torrDb := GetTorrentDB(hash)
@@ -155,8 +142,6 @@ func SetTorrent(hashHex, title, poster, data string) *Torrent {
 }
 
 func RemTorrent(hashHex string) {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	hash := metainfo.NewHashFromHex(hashHex)
 	if sets.BTsets.UseDisk && hashHex != "" && hashHex != "/" {
 		name := filepath.Join(sets.BTsets.TorrentsSavePath, hashHex)
@@ -174,8 +159,6 @@ func RemTorrent(hashHex string) {
 }
 
 func ListTorrent() []*Torrent {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	btlist := bts.ListTorrents()
 	dblist := ListTorrentsDB()
 
@@ -202,8 +185,6 @@ func ListTorrent() []*Torrent {
 }
 
 func DropTorrent(hashHex string) {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	hash := metainfo.NewHashFromHex(hashHex)
 	bts.RemoveTorrent(hash)
 }
@@ -212,12 +193,6 @@ func SetSettings(set *sets.BTSets) {
 	if sets.ReadOnly {
 		return
 	}
-	lockApi.Lock()
-	defer lockApi.Unlock()
-	log.TLogln("drop all torrents")
-	dropAllTorrent()
-	time.Sleep(time.Second * 2)
-	log.TLogln("disconect")
 	bts.Disconnect()
 	sets.SetBTSets(set)
 	log.TLogln("connect")
@@ -230,12 +205,6 @@ func SetDefSettings() {
 	if sets.ReadOnly {
 		return
 	}
-	lockApi.Lock()
-	defer lockApi.Unlock()
-	log.TLogln("drop all torrents")
-	dropAllTorrent()
-	time.Sleep(time.Second * 2)
-	log.TLogln("disconect")
 	bts.Disconnect()
 	sets.SetDefault()
 	log.TLogln("connect")
@@ -252,8 +221,6 @@ func dropAllTorrent() {
 }
 
 func Shutdown() {
-	lockApi.Lock()
-	defer lockApi.Unlock()
 	bts.Disconnect()
 	sets.CloseDB()
 	log.TLogln("Received shutdown. Quit")
@@ -265,8 +232,6 @@ func WriteStatus(w io.Writer) {
 }
 
 func Preload(torr *Torrent, index int) {
-	lockApi.Lock()
-	lockApi.Unlock()
 	cache := float32(sets.BTsets.CacheSize)
 	preload := float32(sets.BTsets.PreloadCache)
 	size := int64((cache / 100.0) * preload)