This is a note to let you know that I've just added the patch titled

s390/qeth: on channel error, reject further cmd requests

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: s390-qeth-on-channel-error-reject-further-cmd-requests.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Mar 29 08:33:08 CEST 2018

From: Julian Wiedmann jwi@linux.vnet.ibm.com Date: Tue, 20 Mar 2018 07:59:15 +0100 Subject: s390/qeth: on channel error, reject further cmd requests

From: Julian Wiedmann jwi@linux.vnet.ibm.com

[ Upstream commit a6c3d93963e4b333c764fde69802c3ea9eaa9d5c ]

When the IRQ handler determines that one of the cmd IO channels has failed and schedules recovery, block any further cmd requests from being submitted. The request would inevitably stall, and prevent the recovery from making progress until the request times out.

This sort of error was observed after Live Guest Relocation, where the pending IO on the READ channel intentionally gets terminated to kick-start recovery. Simultaneously the guest executed SIOCETHTOOL, triggering qeth to issue a QUERY CARD INFO command. The command then stalled in the inoperabel WRITE channel.

Signed-off-by: Julian Wiedmann jwi@linux.vnet.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/net/qeth_core_main.c | 1 + 1 file changed, 1 insertion(+)

--- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -1166,6 +1166,7 @@ static void qeth_irq(struct ccw_device * } rc = qeth_get_problem(cdev, irb); if (rc) { + card->read_or_write_problem = 1; qeth_clear_ipacmd_list(card); qeth_schedule_recovery(card); goto out;

Patches currently in stable-queue which might be from jwi@linux.vnet.ibm.com are

queue-4.4/s390-qeth-when-thread-completes-wake-up-all-waiters.patch queue-4.4/s390-qeth-lock-read-device-while-queueing-next-buffer.patch queue-4.4/net-iucv-free-memory-obtained-by-kzalloc.patch queue-4.4/s390-qeth-on-channel-error-reject-further-cmd-requests.patch queue-4.4/s390-qeth-free-netdevice-when-removing-a-card.patch