Update localfs.go

backends/localfs/localfs.go

@@ -2,6 +2,7 @@ package localfs
 
 import (
 	"encoding/json"
+	"errors"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -151,6 +152,18 @@ func (b LocalfsBackend) Unlock(filename string) (err error) {
 	return
 }
 
+func (b LocalfsBackend) CheckLock(filename string) (locked bool, err error) {
+	lockPath := path.Join(b.locksPath, filename)
+
+	if _, err := os.Stat(lockPath); errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	} else {
+		return true, nil
+	}
+
+	return false, err
+}
+
 func (b LocalfsBackend) Put(key string, r io.Reader, expiry time.Time, deleteKey, accessKey string, srcIp string) (m backends.Metadata, err error) {
 	filePath := path.Join(b.filesPath, key)