copy_file_range.2: New page documenting copy_file_range()
copy_file_range() is a new system call for copying ranges of data
completely in the kernel. This gives filesystems an opportunity to
implement some kind of "copy acceleration", such as reflinks or
server-side-copy (in the case of NFS).
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>