These patches eliminate data writes completely on Linux if fallocate FALLOC_FL_ZERO_RANGE or FALLOC_FL_PUNCH_HOLE are supported on underlying filesystem. This should seriously increase performance in some cases.
Signed-off-by: Denis V. Lunev <d...@openvz.org> CC: Kevin Wolf <kw...@redhat.com> CC: Stefan Hajnoczi <stefa...@redhat.com>
