Re: [PATCH 2/5] blktrace: fix debugfs use after free

[Luis Chamberlain]

On Thu, Apr 16, 2020 at 10:10:36AM +0800, Ming Lei wrote:
> In theory, multiple partitions can be traced concurrently, but looks
> it never works, so it won't cause trouble for multiple partition trace.
> 
> One userspace visible change is that blktrace debugfs dir name is switched 
> to disk name from partition name in case of partition trace, will it
> break some utilities?

How is this possible, its not clear to me, we go from:

-	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
-					    blk_debugfs_root);

To this:

+	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
+					    blk_debugfs_root);


Maybe I am overlooking something.

  Luis