s390/dasd: fix double module refcount decrement

Once the discipline is associated with the device, deleting the device
takes care of decrementing the module's refcount.  Doing it manually on
this error path causes refcount to artificially decrease on each error
while it should just stay the same.

Fixes: c020d722b110 ("s390/dasd: fix panic during offline processing")
Signed-off-by: Miroslav Franc <mfranc@suse.cz>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20240209124522.3697827-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index fdb6cb8d8abf090b0ddac87a03642b5b857d5ae5..2f3adf5d8fee4427477f74db74f36ff98952a329 100644 (file)
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -3503,12 +3503,11 @@ int dasd_generic_set_online(struct ccw_device *cdev,
                dasd_delete_device(device);
                return -EINVAL;
        }
+       device->base_discipline = base_discipline;
        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;
 
        /* check_device will allocate block device if necessary */
@@ -3516,8 +3515,6 @@ int dasd_generic_set_online(struct ccw_device *cdev,
        if (rc) {
                dev_warn(dev, "Setting the DASD online with discipline %s failed with rc=%i\n",
                         discipline->name, rc);
-               module_put(discipline->owner);
-               module_put(base_discipline->owner);
                dasd_delete_device(device);
                return rc;
        }