[$] Supporting large block sizes

At the
2023 Linux Storage, Filesystem,
Memory-Management and BPF Summit, Luis Chamberlain led a plenary
session on kernel support for block sizes larger than 4KB. There are
assumptions in the current kernel that the block size used by a block-layer
device is less than or equal to the system's page size—both are usually 4KB
today. But there have been efforts over the years to remove that
restriction; that work may be heading toward fruition, in part because of
the folio efforts of late, though there are
still lots of areas that need attention.