1. A method, in an input/output (I/O) adapter, comprising: receiving, from an application instance, a user space operation requesting creation of a resource allocation for direct linear block address (LBA) based input/output (I/O) between the application instance and a physical storage device; creating the resource allocation in a LBA table entry, of an LBA table, associated with the I/O adapter and the application instance; and returning results of the creation of the resource allocation to the application instance.