The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 105fa2f44e504c830697b0c794822112d79808dc Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Sat, 3 Jun 2017 05:35:47 -0700
Subject: [PATCH] iscsi-target: Fix delayed logout processing greater than
SECONDS_FOR_LOGOUT_COMP
This patch fixes a BUG() in iscsit_close_session() that could be
triggered when iscsit_logout_post_handler() execution from within
tx thread context was not run for more than SECONDS_FOR_LOGOUT_COMP
(15 seconds), and the TCP connection didn't already close before
then forcing tx thread context to automatically exit.
This would manifest itself during explicit logout as:
[33206.974254] 1 connection(s) still exist for iSCSI session to iqn.1993-08.org.debian:01:3f5523242179
[33206.980184] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 2100.772 msecs
[33209.078643] ------------[ cut here ]------------
[33209.078646] kernel BUG at drivers/target/iscsi/iscsi_target.c:4346!
Normally when explicit logout attempt fails, the tx thread context
exits and iscsit_close_connection() from rx thread context does the
extra cleanup once it detects conn->conn_logout_remove has not been
cleared by the logout type specific post handlers.
To address this special case, if the logout post handler in tx thread
context detects conn->tx_thread_active has already been cleared, simply
return and exit in order for existing iscsit_close_connection()
logic from rx thread context do failed logout cleanup.
Reported-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Tested-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Mike Christie <mchristi@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 3.14+
Tested-by: Gary Guo <ghg@xxxxxxxxx>
Tested-by: Chu Yuan Lin <cyl@xxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 0d8f81591bed..c0254516b380 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4423,8 +4423,11 @@ static void iscsit_logout_post_handler_closesession(
* always sleep waiting for RX/TX thread shutdown to complete
* within iscsit_close_connection().
*/
- if (!conn->conn_transport->rdma_shutdown)
+ if (!conn->conn_transport->rdma_shutdown) {
sleep = cmpxchg(&conn->tx_thread_active, true, false);
+ if (!sleep)
+ return;
+ }
atomic_set(&conn->conn_logout_remove, 0);
complete(&conn->conn_logout_comp);
@@ -4440,8 +4443,11 @@ static void iscsit_logout_post_handler_samecid(
{
int sleep = 1;
- if (!conn->conn_transport->rdma_shutdown)
+ if (!conn->conn_transport->rdma_shutdown) {
sleep = cmpxchg(&conn->tx_thread_active, true, false);
+ if (!sleep)
+ return;
+ }
atomic_set(&conn->conn_logout_remove, 0);
complete(&conn->conn_logout_comp);