Patent ID: 8918559
Filing Date: 2014-12-23
Classification: G06F

Abstract:
1. A method comprising: requesting, via a processor, data from an input/output (I/O) device comprising an I/O buffer, the requesting comprising initiating a subchannel; determining whether the subchannel supports data divisions, the determining comprising requesting stored subchannel queued-direct I/O data (SSQD) from the I/O device and inspecting at least one bit in the SSQD data; determining whether the requested data includes a metadata block, the determining whether the requested data includes a metadata block responsive to determining that the subchannel support data divisions; notifying the subchannel that the requested data includes the metadata block in response to determining that the requested data includes the metadata block; and identifying a location of storage in a storage-buffer-address-list (SBAL) associated with the requested data, the identifying in response to the notifying; wherein the SBAL includes a protection count field configured to describe a length of a variable length protection information block and user data count field configured to describe a length of a variable length user data block, wherein the protection count field is located at a first known location before the variable length protection information block and the user data count field is located at a second known location in the variable length protection information block, wherein the variable length protection information block and the variable length user data block are separate from each other and do not encapsulate each other.