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From:   Qinglang Miao <miaoqinglang@huawei.com>
To:     Steffen Maier <maier@linux.ibm.com>,
        Benjamin Block <bblock@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>
CC:     <linux-s390@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        "Qinglang Miao" <miaoqinglang@huawei.com>
Subject: [PATCH v2] scsi: zfcp: move the position of put_device
Date:   Tue, 1 Dec 2020 10:47:16 +0800
Message-ID: <20201201024716.42926-1-miaoqinglang@huawei.com>
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Precedence: bulk

Have the `put_device()` call after `device_unregister()` in both
`zfcp_unit_remove()` and `zfcp_sysfs_port_remove_store()` to make
it more natural, for put_device() ought to be the last time we
touch the object in both functions.

And add comments after put_device to make codes clearer.

Suggested-by: Steffen Maier <maier@linux.ibm.com>
Suggested-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 v2: add comments after put_device as Steffen suggested.

 drivers/s390/scsi/zfcp_sysfs.c | 4 ++--
 drivers/s390/scsi/zfcp_unit.c  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 8d9662e8b..ef6d35a37 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -327,10 +327,10 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
 	list_del(&port->list);
 	write_unlock_irq(&adapter->port_list_lock);
 
-	put_device(&port->dev);
-
 	zfcp_erp_port_shutdown(port, 0, "syprs_1");
 	device_unregister(&port->dev);
+
+	put_device(&port->dev); /* undo zfcp_get_port_by_wwpn() */
  out:
 	zfcp_ccw_adapter_put(adapter);
 	return retval ? retval : (ssize_t) count;
diff --git a/drivers/s390/scsi/zfcp_unit.c b/drivers/s390/scsi/zfcp_unit.c
index e67bf7388..59333f025 100644
--- a/drivers/s390/scsi/zfcp_unit.c
+++ b/drivers/s390/scsi/zfcp_unit.c
@@ -255,9 +255,9 @@ int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun)
 		scsi_device_put(sdev);
 	}
 
-	put_device(&unit->dev);
-
 	device_unregister(&unit->dev);
 
+	put_device(&unit->dev); /* undo _zfcp_unit_find() */
+
 	return 0;
 }
-- 
2.23.0