.net core 在linux下上传文件没有权限

Question

using (var stream = new FileStream(filename, FileMode.Create)) {    upFile.CopyTo(stream);} 在windows下测试是没问题的。Access to the path '/var/www/helloworld/upload/xxx.jpg' is denied.System.UnauthorizedAccessException: Access to the path '/var/www/helloworld/upload/xxx.jpg' is denied. ---> System.IO.IOException: Permission denied--- End of inner exception stack trace ---at Interop.ThrowExceptionForIoErrno(ErrorInfo errorInfo, String path, Boolean isDirectory, Func`2 errorRewriter)at Microsoft.Win32.SafeHandles.SafeFileHandle.Open(String path, OpenFlags flags, Int32 mode)at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)