4.9-stable review patch. If anyone has any objections, please let me know.
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From: Stefan Haberland sth@linux.vnet.ibm.com
[ 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 sth@linux.vnet.ibm.com Signed-off-by: Martin Schwidefsky schwidefsky@de.ibm.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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) {