This is a note to let you know that I've just added the patch titled
iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iscsi-target-fix-delayed-logout-processing-greater-than-seconds_for_logout_comp.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 105fa2f44e504c830697b0c794822112d79808dc Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Sat, 3 Jun 2017 05:35:47 -0700
Subject: iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
commit 105fa2f44e504c830697b0c794822112d79808dc upstream.
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>
Tested-by: Gary Guo <ghg@xxxxxxxxx>
Tested-by: Chu Yuan Lin <cyl@xxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4431,8 +4431,11 @@ static void iscsit_logout_post_handler_c
* 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);
@@ -4448,8 +4451,11 @@ static void iscsit_logout_post_handler_s
{
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);
Patches currently in stable-queue which might be from nab@xxxxxxxxxxxxxxx are
queue-4.9/iscsi-target-reject-immediate-data-underflow-larger-than-scsi-transfer-length.patch
queue-4.9/iscsi-target-fix-delayed-logout-processing-greater-than-seconds_for_logout_comp.patch
queue-4.9/target-fix-kref-refcount-underflow-in-transport_cmd_finish_abort.patch