Abstract: An adaptation of a computer operating system manages storage of EA (extended attribute) data in association with object names, the latter representing paths in direct access storage devices (e.g. directories and sub-directories), and data files stored in such paths. EA data stored in association with a data file name can be accessed either jointly with or separate from the respective data file. EA data comprises one or more variable length sets of bytes stored in disk drive sectors assigned by the operating system. The location of each set is determinable by means of an EA handle that is stored in a path table containing the respective object name. Function calls from application programs to the operating system use either a file name or EA handle to access EA data. Function calls specifying only an EA handle allow EA information to be stored, modified or read without specific association to or linkage with file data.

Abstract: In a multitasking data processing system, I/O requests to a disk drive are staged in holding queues from which they are transferred to a service queue. Requests in the latter queue are directly serviced on a FIFO basis by a device driver module running on the system. The system maintains a set of holding queues and an associated service queue separately for each physical drive in the system. Holding queues in each set are prioritized in accordance with base priorities of tasks, and I/O requests to disk drives are entered into associated holding queues having priorities corresponding to those of task threads for which such requests are originated. Prioritization of the holding queues, and a starvation advancement process performed to advance "oldest" enqueued requests to higher priority holding queues, causes the requests to be presented to the disk drive in a sequence based in part on respective task priorities and in part on "fairness" servicing of "service starved" requests.