diff --git a/internal/caches/reader_file.go b/internal/caches/reader_file.go
index 78756c4..f62cb23 100644
--- a/internal/caches/reader_file.go
+++ b/internal/caches/reader_file.go
@@ -314,8 +314,9 @@ func (this *FileReader) ReadBodyRange(buf []byte, start int64, end int64, callba
 	}
 
 	for {
+		var n int
 		fsutils.ReaderLimiter.Ack()
-		n, err := this.fp.Read(buf)
+		n, err = this.fp.Read(buf)
 		fsutils.ReaderLimiter.Release()
 		if n > 0 {
 			var n2 = int(end-offset) + 1
diff --git a/internal/caches/storage_file.go b/internal/caches/storage_file.go
index 384ce9e..73aba4a 100644
--- a/internal/caches/storage_file.go
+++ b/internal/caches/storage_file.go
@@ -380,6 +380,7 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool,
 
 	// 检查文件记录是否已过期
 	var estimatedSize int64
+	var existInList bool
 	if !useStale {
 		exists, filesize, err := this.list.Exist(hash)
 		if err != nil {
@@ -389,6 +390,7 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool,
 			return nil, ErrNotFound
 		}
 		estimatedSize = filesize
+		existInList = true
 	}
 
 	// 尝试通过MMAP读取
@@ -412,7 +414,13 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool,
 
 	var err error
 	if openFile == nil {
+		if existInList {
+			fsutils.ReaderLimiter.Ack()
+		}
 		fp, err = os.OpenFile(path, os.O_RDONLY, 0444)
+		if existInList {
+			fsutils.ReaderLimiter.Release()
+		}
 		if err != nil {
 			if !os.IsNotExist(err) {
 				return nil, err
@@ -583,7 +591,7 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 		// 数据库中是否存在
 		existsCacheItem, _, _ := this.list.Exist(hash)
 		if existsCacheItem {
-			readerFp, err := os.OpenFile(tmpPath, os.O_RDONLY, 0444)
+			readerFp, err := fsutils.OpenFile(tmpPath, os.O_RDONLY, 0444)
 			if err == nil {
 				var partialReader = NewPartialFileReader(readerFp)
 				err = partialReader.Init()
@@ -616,8 +624,10 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 	if isNewCreated && existsFile {
 		flags |= os.O_TRUNC
 	}
-	if !isFlushing && !fsutils.WriterLimiter.TryAck() {
-		return nil, ErrServerIsBusy
+	if !isFlushing {
+		if !fsutils.WriterLimiter.TryAck() {
+			return nil, ErrServerIsBusy
+		}
 	}
 	writer, err := os.OpenFile(tmpPath, flags, 0666)
 	if !isFlushing {
diff --git a/internal/utils/fs/limiter.go b/internal/utils/fs/limiter.go
index f1a49d3..c212a0a 100644
--- a/internal/utils/fs/limiter.go
+++ b/internal/utils/fs/limiter.go
@@ -8,8 +8,8 @@ import (
 )
 
 var maxThreads = runtime.NumCPU()
-var WriterLimiter = NewLimiter(max(maxThreads, 4))
-var ReaderLimiter = NewLimiter(max(maxThreads*2, 8))
+var WriterLimiter = NewLimiter(max(maxThreads, 8))
+var ReaderLimiter = NewLimiter(max(maxThreads, 8))
 
 type Limiter struct {
 	threads      chan struct{}
@@ -60,7 +60,7 @@ func (this *Limiter) Ack() {
 }
 
 func (this *Limiter) TryAck() bool {
-	const timeoutDuration = 1 * time.Second
+	const timeoutDuration = 500 * time.Millisecond
 
 	var timeout *time.Timer
 	select {
diff --git a/internal/utils/fs/os.go b/internal/utils/fs/os.go
index 51da4fe..79c06c6 100644
--- a/internal/utils/fs/os.go
+++ b/internal/utils/fs/os.go
@@ -2,7 +2,9 @@
 
 package fsutils
 
-import "os"
+import (
+	"os"
+)
 
 func Remove(filename string) (err error) {
 	WriterLimiter.Ack()
@@ -31,3 +33,24 @@ func WriteFile(filename string, data []byte, perm os.FileMode) (err error) {
 	WriterLimiter.Release()
 	return
 }
+
+func OpenFile(name string, flag int, perm os.FileMode) (f *os.File, err error) {
+	if flag&os.O_RDONLY == os.O_RDONLY {
+		ReaderLimiter.Ack()
+	}
+
+	f, err = os.OpenFile(name, flag, perm)
+
+	if flag&os.O_RDONLY == os.O_RDONLY {
+		ReaderLimiter.Release()
+	}
+
+	return
+}
+
+func Open(name string) (f *os.File, err error) {
+	ReaderLimiter.Ack()
+	f, err = os.Open(name)
+	ReaderLimiter.Release()
+	return
+}
diff --git a/internal/utils/fs/os_test.go b/internal/utils/fs/os_test.go
new file mode 100644
index 0000000..3de6d82
--- /dev/null
+++ b/internal/utils/fs/os_test.go
@@ -0,0 +1,17 @@
+// Copyright 2024 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package fsutils_test
+
+import (
+	fsutils "github.com/TeaOSLab/EdgeNode/internal/utils/fs"
+	"os"
+	"testing"
+)
+
+func TestOpenFile(t *testing.T) {
+	f, err := fsutils.OpenFile("./os_test.go", os.O_RDONLY, 0444)
+	if err != nil {
+		t.Fatal(err)
+	}
+	_ = f.Close()
+}