[PATCH V2 1/2] ublk_drv: fix error handling of ublk_add_dev

[Ming Lei <ming.lei@xxxxxxxxxx>]

__ublk_destroy_dev() is called for handling error in ublk_add_dev(),
but either tagset isn't allocated or mutex isn't initialized.

So fix the issue by letting ublk_add_dev cleanup its own allocation,
and simply call kfree(ub) outside of ublk_add_dev which is named
as ublk_add_tagset(), meantime ublk_add_chdev() is moved out too.

Now the error handling in ublk_ctrl_add_dev() becomes more readable.

Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
 drivers/block/ublk_drv.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index f058f40b639c..a427f020527d 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1093,7 +1093,7 @@ static void ublk_align_max_io_size(struct ublk_device *ub)
 }
 
 /* add tag_set & cdev, cleanup everything in case of failure */
-static int ublk_add_dev(struct ublk_device *ub)
+static int ublk_add_tagset(struct ublk_device *ub)
 {
 	int err = -ENOMEM;
 
@@ -1108,7 +1108,7 @@ static int ublk_add_dev(struct ublk_device *ub)
 	INIT_DELAYED_WORK(&ub->monitor_work, ublk_daemon_monitor_work);
 
 	if (ublk_init_queues(ub))
-		goto out_destroy_dev;
+		return err;
 
 	ub->tag_set.ops = &ublk_mq_ops;
 	ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues;
@@ -1125,13 +1125,10 @@ static int ublk_add_dev(struct ublk_device *ub)
 	mutex_init(&ub->mutex);
 	spin_lock_init(&ub->mm_lock);
 
-	/* add char dev so that ublksrv daemon can be setup */
-	return ublk_add_chdev(ub);
+	return 0;
 
 out_deinit_queues:
 	ublk_deinit_queues(ub);
-out_destroy_dev:
-	__ublk_destroy_dev(ub);
 	return err;
 }
 
@@ -1330,7 +1327,18 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
 	/* update device id */
 	ub->dev_info.dev_id = ub->ub_number;
 
-	ret = ublk_add_dev(ub);
+	ret = ublk_add_tagset(ub);
+	if (ret) {
+		kfree(ub);
+		goto out_unlock;
+	}
+
+	/*
+	 * add char dev so that ublksrv daemon can be setup
+	 *
+	 * ublk_add_chdev() will cleanup everything if it fails.
+	 */
+	ret = ublk_add_chdev(ub);
 	if (ret)
 		goto out_unlock;
 
-- 
2.31.1