s390/dasd: fix inability to set a DASD device offline

Fix ref counting for DASD devices leading to an inability to set a
DASD device offline.
Before a worker is scheduled the DASD device driver takes a reference
to the device. If the worker was already scheduled this reference was
never freed.
Fix by giving the reference to the DASD device free when
schedule_work() returns false.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 8 insertions, 4 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 26a51dc4278d..cd57857a1c84 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -579,7 +579,8 @@ void dasd_kick_device(struct dasd_device *device)
 {
         dasd_get_device(device);
         /* queue call to dasd_kick_device to the kernel event daemon. */
-        schedule_work(&device->kick_work);
+        if (!schedule_work(&device->kick_work))
+                dasd_put_device(device);
 }
 EXPORT_SYMBOL(dasd_kick_device);
 
@@ -599,7 +600,8 @@ void dasd_reload_device(struct dasd_device *device)
 {
         dasd_get_device(device);
         /* queue call to dasd_reload_device to the kernel event daemon. */
-        schedule_work(&device->reload_device);
+        if (!schedule_work(&device->reload_device))
+                dasd_put_device(device);
 }
 EXPORT_SYMBOL(dasd_reload_device);
 
@@ -619,7 +621,8 @@ void dasd_restore_device(struct dasd_device *device)
 {
         dasd_get_device(device);
         /* queue call to dasd_restore_device to the kernel event daemon. */
-        schedule_work(&device->restore_device);
+        if (!schedule_work(&device->restore_device))
+                dasd_put_device(device);
 }
 
 /*
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 49b48a887c66..6215f6455eb8 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -1628,7 +1628,8 @@ static void dasd_eckd_kick_validate_server(struct dasd_device *device)
                 return;
         }
         /* queue call to do_validate_server to the kernel event daemon. */
-        schedule_work(&device->kick_validate);
+        if (!schedule_work(&device->kick_validate))
+                dasd_put_device(device);
 }
 
 static u32 get_fcx_max_data(struct dasd_device *device)