Enabling user space middleware or applications to pass file name based storage requests directly to a physical I/O Adapter without run-time involvement from the local Operating System (OS)is provided. A mechanism is provided for using a file protection table (FPT) data structure, which may include a file name protection table (FNPT) and file extension protection table (FEPT), to control user space and out of user space Input/Output (I/O) operations. The FNPT has an entry for each file managed by the OS′ file system and points to a segment of the FEPT. Each entry in the FEPT may include a protection domain, along with other protection table context information, against which I/O requests may be checked to determine if an application instance that submitted the I/O requests may access the file identified in the I/O requests.