Using `bs_allocate_and_copy_cluster()` instead of a zero-length write
makes it possible to inflate/decouple snapshots, as the writes would
fail with -EPERM, because the snapshots are marked as read-only.
Additionally, zero-length non-vector requests are now completed
immediately. It makes it consistent with the vector path (which already
does that) and allows us to use the zero-length reads as a context for
cluster copy.
Fixes#2028.
Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: Ib7fdee352972ecf808833aa179820d85cfab7eed
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8918
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>