Flag VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP is only used for WRITE
ZEROES command, vhost-blk target may tell VM via 'write_zeroes_may_unmap'
configuration that the backend can support this flag, however, Linux
generic block driver doesn't have such logic, it will enable this
flag by default(without REQ_NOUNMAP) with WRITE ZEROES command,
so the backend may choose to ignore this flag, because WRITE ZEROES
with this flag isn't mandatory.
Fix issue #1714.
Change-Id: Ic9388f39269720a23c00d41cba585d2a5abc3cfb
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5565
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: <dongx.yi@intel.com>
e18788d30e