[PATCH] iscsi-target: Fix SessionType=Discovery RX context conn->conn_logout_comp hang

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Hi James & Co.

Below is the one outstanding bugfix patch to apply on top of iscsi-target
PATCH-v5 for an initial .40-rc1 / .2.8.0-rc1 merge into scsi-misc.

Once again, thanks to Martin Svec for efficently tracking down this issue
and getting this patch tested+verified the initial merge code on .39-rc..

Thanks!

--nab

----------------------------------------------------------------------------

This patch fixes a bug in iscsi_target_rx_thread():ISCSI_OP_LOGOUT where
conn->conn_logout_comp was sleeping definately on wait_for_completion with
SessionType=Discovery.  This was occuring because the per connection NopIN
timer is correctly not enabled for discovery sessions, and hence does not
fire to trigger an connection failure event in iscsi_target_tx_thread() ->
iscsit_close_connection() in order to wakeup the sleeping RX thread context.

This patch changes the conn_logout_comp to use wait_for_completion_timeout()
for both cases and defines a SECONDS_FOR_LOGOUT_COMP of 15 seconds.

Reported-by & Tested-by: Martin Svec <martin.svec@zoner.cz>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
---
 drivers/target/iscsi/iscsi_target.c      |    3 ++-
 drivers/target/iscsi/iscsi_target_core.h |    1 +
 2 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 6bba5fd..964cadc 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4292,7 +4292,8 @@ restart:
 		case ISCSI_OP_LOGOUT:
 			ret = iscsit_handle_logout_cmd(conn, buffer);
 			if (ret > 0) {
-				wait_for_completion(&conn->conn_logout_comp);
+				wait_for_completion_timeout(&conn->conn_logout_comp,
+						SECONDS_FOR_LOGOUT_COMP * HZ);
 				goto transport_err;
 			} else if (ret < 0)
 				goto transport_err;
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index c7ca0a0..af24171 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -15,6 +15,7 @@
 #define ISCSI_RX_THREAD_TCP_TIMEOUT	2
 #define SECONDS_FOR_ASYNC_LOGOUT	10
 #define SECONDS_FOR_ASYNC_TEXT		10
+#define SECONDS_FOR_LOGOUT_COMP		15
 #define WHITE_SPACE			" \t\v\f\n\r"
 
 /* struct iscsi_node_attrib sanity values */
-- 
1.7.5.2