[PATCH v5 04/10] blk-mq: Only unregister hctxs for which registration succeeded

[Bart Van Assche <bart.vanassche@sandisk.com>]

Hctx unregistration involves calling kobject_del(). kobject_del()
must not be called if kobject_add() has not been called. Hence in
the error path only unregister hctxs for which registration succeeded.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
---
 block/blk-mq-sysfs.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index c2cac20d981d..053549a32778 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -323,16 +323,24 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
 	queue_for_each_hw_ctx(q, hctx, i) {
 		ret = blk_mq_register_hctx(hctx);
 		if (ret)
-			break;
+			goto unreg;
 	}
 
-	if (ret)
-		__blk_mq_unregister_dev(dev, q);
-	else
-		q->mq_sysfs_init_done = true;
+	q->mq_sysfs_init_done = true;
 
 out:
 	return ret;
+
+unreg:
+	while (--i >= 0)
+		blk_mq_unregister_hctx(hctx);
+
+	blk_mq_debugfs_unregister_mq(q);
+
+	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
+	kobject_del(&q->mq_kobj);
+	kobject_put(&dev->kobj);
+	goto out;
 }
 
 int blk_mq_register_dev(struct device *dev, struct request_queue *q)
-- 
2.12.2