From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:40554 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934041AbeDKTFl (ORCPT ); Wed, 11 Apr 2018 15:05:41 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Haberland , Martin Schwidefsky , Sasha Levin Subject: [PATCH 4.9 252/310] s390/dasd: fix hanging safe offline Date: Wed, 11 Apr 2018 20:36:31 +0200 Message-Id: <20180411183633.278275747@linuxfoundation.org> In-Reply-To: <20180411183622.305902791@linuxfoundation.org> References: <20180411183622.305902791@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Haberland [ Upstream commit e8ac01555d9e464249e8bb122337d6d6e5589ccc ] The safe offline processing may hang forever because it waits for I/O which can not be started because of the offline flag that prevents new I/O from being started. Allow I/O to be started during safe offline processing because in this special case we take care that the queues are empty before throwing away the device. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/s390/block/dasd.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -1950,8 +1950,12 @@ static int __dasd_device_is_unusable(str { int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM); - if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) { - /* dasd is being set offline. */ + if (test_bit(DASD_FLAG_OFFLINE, &device->flags) && + !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) { + /* + * dasd is being set offline + * but it is no safe offline where we have to allow I/O + */ return 1; } if (device->stopped) {