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 metadata block includes a variable length protection information block and a variable length user data block.