Why the linux does not allow the access to a file in the device driver?

["Daniel (Youngwhan) Song" <breadncup@xxxxxxxxx>]

Hi,

Could somebody help me to understand the reason why the linux kernel does not allow the access to a file in the device driver? For example, for debugging purpose, if a device driver want to log some data in a file by using open/write/read method like in user application, how a driver can access to a file in a specific filesystem? Any comment or docs or web pages would be appreciated.

Thank you,

Dan.