Add the flag destructed to struct spdk_iscsi_tgt_node and
iscsi_op_login_check_target() refers it and returns
ISCSI_LOGIN_TARGET_REMOVED if it is true.
When destructing iSCSI target node, it will be nice if iSCSI library
can stop further connections are created but, connections are not
associated with any target node until processing login. Hence stop
creating sessions instead.
Additionally, when destructing iSCSI target node, if the flag destructed
is already set, return immediately, and the flag destructed does not
affect discovery session.
Change-Id: Ic73bdd93f2ca7d5ca1d2f897d5046cbc51650d5f
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/450881
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>