On 06/07/2016 10:31 AM, Christoph Hellwig wrote:

Of course you can, and every user of configfs relies on being able
to create directories from the kernel using either the default_groups
list, or through the use of configfs_register_group().

Apparently configfs_register_group() has been added last year (Nov 2015; 
commit 5cf6a51e6062)? This is interesting and I think this functionality 
would also useful for LIO target drivers, e.g. ib_srpt and tcm_qla2xxx.

Bart.