This patch adds support for using zero-copy operations to execute IO
requests in the TCP transport. Of course, they're only used if the
underlying bdev supports them. Additionally, only requests with no
in-capsule-data can be executed using this mechanism.
Added several new states to accommodate for the difference in a way
zero-copy is handled. Also, these flows very depending on the type of a
request (read or write). It stems from zero-copy semantics: to perform
a write we need to wait for zcopy_end completion, while for reads
zcopy_end can only be submitted once we send all of the requested data
to the host.
Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: Ie02b494c24bc1acc98557cb4b02e867abf9064e4
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/10796
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
794d47d4c4