s390/dasd: fix hanging safe offline

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>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index b0c65dcb6865..c72ac57940f4 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1965,8 +1965,12 @@ static int __dasd_device_is_unusable(struct dasd_device *device,
 {
         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) {