[S390] cio: add per device initialization status flag

The function ccw_device_unregister has to ensure to remove
all references obtained by device_add and device_initialize.
Unfortunately it gets called for devices which are
1) uninitialized, 2) initialized but unregistered, and
3) registered devices. To distinguish 1) and 2) this patch
introduces a new flag "initialized", which is 1 as long as we
hold the initial device reference.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index f4401ede768a..e8cb99a63cc6 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -304,7 +304,11 @@ int ccw_device_is_orphan(struct ccw_device *cdev)
 static void ccw_device_unregister(struct ccw_device *cdev)
 {
         if (device_is_registered(&cdev->dev)) {
+                /* Undo device_add(). */
                 device_del(&cdev->dev);
+        }
+        if (cdev->private->flags.initialized) {
+                cdev->private->flags.initialized = 0;
                 /* Release reference from device_initialize(). */
                 put_device(&cdev->dev);
         }
@@ -716,6 +720,7 @@ static int io_subchannel_initialize_dev(struct subchannel *sch,
                 put_device(&cdev->dev);
                 return -ENODEV;
         }
+        cdev->private->flags.initialized = 1;
         return 0;
 }
 
@@ -998,6 +1003,7 @@ static int io_subchannel_probe(struct subchannel *sch)
                 cdev = sch_get_cdev(sch);
                 cdev->dev.groups = ccwdev_attr_groups;
                 device_initialize(&cdev->dev);
+                cdev->private->flags.initialized = 1;
                 ccw_device_register(cdev);
                 /*
                  * Check if the device is already online. If it is
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index ca1063d6b505..dbc69a5a043e 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -167,6 +167,7 @@ struct ccw_device_private {
                 unsigned int resuming:1;    /* recognition while resume */
                 unsigned int pgroup:1;      /* pathgroup is set up */
                 unsigned int mpath:1;       /* multipathing is set up */
+                unsigned int initialized:1; /* set if initial reference held */
         } __attribute__((packed)) flags;
         unsigned long intparm;  /* user interruption parameter */
         struct qdio_irq *qdio_data;