[PATCH] s390: dasd reference counting
When using the dasd diag discipline, the base discipline module (eckd or fba)
can be unloaded, even though the dasd driver requires both discipline modules
(base and diag) to work correctly.
Implement reference counting for both base and diag discipline modules in
order to fix this.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 08c88fc..06bb992 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -156,7 +156,12 @@
/* disable extended error reporting for this device */
dasd_disable_eer(device);
/* Forget the discipline information. */
+ if (device->discipline)
+ module_put(device->discipline->owner);
device->discipline = NULL;
+ if (device->base_discipline)
+ module_put(device->base_discipline->owner);
+ device->base_discipline = NULL;
device->state = DASD_STATE_NEW;
dasd_free_queue(device);
@@ -1880,9 +1885,10 @@
*/
int
dasd_generic_set_online (struct ccw_device *cdev,
- struct dasd_discipline *discipline)
+ struct dasd_discipline *base_discipline)
{
+ struct dasd_discipline *discipline;
struct dasd_device *device;
int rc;
@@ -1890,6 +1896,7 @@
if (IS_ERR(device))
return PTR_ERR(device);
+ discipline = base_discipline;
if (device->features & DASD_FEATURE_USEDIAG) {
if (!dasd_diag_discipline_pointer) {
printk (KERN_WARNING
@@ -1901,6 +1908,16 @@
}
discipline = dasd_diag_discipline_pointer;
}
+ if (!try_module_get(base_discipline->owner)) {
+ dasd_delete_device(device);
+ return -EINVAL;
+ }
+ if (!try_module_get(discipline->owner)) {
+ module_put(base_discipline->owner);
+ dasd_delete_device(device);
+ return -EINVAL;
+ }
+ device->base_discipline = base_discipline;
device->discipline = discipline;
rc = discipline->check_device(device);
@@ -1909,6 +1926,8 @@
"dasd_generic couldn't online device %s "
"with discipline %s rc=%i\n",
cdev->dev.bus_id, discipline->name, rc);
+ module_put(discipline->owner);
+ module_put(base_discipline->owner);
dasd_delete_device(device);
return rc;
}
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index d1b08fa..5efac1b 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -321,6 +321,7 @@
/* Device discipline stuff. */
struct dasd_discipline *discipline;
+ struct dasd_discipline *base_discipline;
char *private;
/* Device state and target state. */