Xiaodong Liu c45a589901 nbd: avoid payload malloc when its size is 0
Some nbd io type has no payload, like NBD_CMD_DISC.

Change-Id: I17babf625f51d32bf07fa7a9b6a7396660b39cd5
Signed-off-by: Xiaodong Liu <xiaodong.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/389779
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-12-04 11:55:12 -05:00
..
2017-08-02 13:27:21 -04:00