This patch adds support for login negotiation multi-plexing in
iscsi-target code.
This involves handling the first login request PDU + payload and
login response PDU + payload within __iscsi_target_login_thread()
process context, and then changing struct sock->sk_data_ready()
so that all subsequent exchanges are handled by workqueue process
context, to allow other incoming login requests to be received
in parallel by __iscsi_target_login_thread().
Upon login negotiation completion (or failure), ->sk_data_ready()
is replaced with the original kernel sockets handler saved in
iscsi_conn->orig_data_ready.
v3 changes:
- Convert iscsi_target_sk_data_ready() lock access to
write[lock,unlock]_bh()
- Only clear LOGIN_FLAGS_READ_ACTIVE when iscsi_target_do_login()
returns zero
- Add LOGIN_FLAGS_READY + LOGIN_FLAGS_CLOSED bit checks to
iscsi_target_sk_data_ready()
- Make INIT_DELAYED_WORK() + iscsi_target_set_sock_callbacks() setup
happen earlier by moving from iscsi_target_start_negotiation() into
iscsi_target_locate_portal()
- Set LOGIN_FLAGS_READY bit in iscsi_target_start_negotiation()
after iscsi_target_do_login() returns zero.
v2 changes:
- Add login_timer in iscsi_target_do_login_rx() to avoid
possible endless sleep with MSG_WAITALL for traditional
iscsi-target in certain network configurations.
- Convert lprintk() -> pr_debug()
- Remove forward declarations of iscsi_target_set_sock_callbacks(),
iscsi_target_restore_sock_callbacks() and iscsi_target_sk_data_ready()
- Make iscsi_target_set_sock_callbacks + iscsi_target_restore_sock_callbacks()
static (Fengguang)
- Make iscsi_target_do_login_rx() safe for iser-target w/o conn->sock
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>