From: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
drivers/s390/cio/device.c | 6 ++++++
drivers/s390/cio/io_sch.h | 1 +
2 files changed, 7 insertions(+)
Index: quilt-2.6/drivers/s390/cio/device.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/device.c 2009-11-13 16:08:21.000000000 +0100
+++ quilt-2.6/drivers/s390/cio/device.c 2009-11-13 16:08:22.000000000 +0100
@@ -304,7 +304,11 @@
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 @@
put_device(&cdev->dev);
return -ENODEV;
}
+ cdev->private->flags.initialized = 1;
return 0;
}
@@ -998,6 +1003,7 @@
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
Index: quilt-2.6/drivers/s390/cio/io_sch.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/io_sch.h 2009-11-13 16:08:21.000000000 +0100
+++ quilt-2.6/drivers/s390/cio/io_sch.h 2009-11-13 16:08:22.000000000 +0100
@@ -167,6 +167,7 @@
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;
--
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