This patch fixes a regression introduced with the following commit
in v4.0-rc1 code, where a iscsit_start_kthreads() failure triggers
a NULL pointer dereference OOPs:
commit 88dcd2dab5
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu Feb 26 22:19:15 2015 -0800
iscsi-target: Convert iscsi_thread_set usage to kthread.h
To address this bug, move iscsit_start_kthreads() immediately
preceeding the transmit of last login response, before signaling
a successful transition into full-feature-phase within existing
iscsi_target_do_tx_login_io() logic.
This ensures that no target-side resource allocation failures can
occur after the final login response has been successfully sent.
Also, it adds a iscsi_conn->rx_login_comp to allow the RX thread
to sleep to prevent other socket related failures until the final
iscsi_post_login_handler() call is able to complete.
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
e54198657b