[PATCH 1/3] nvme: decouple nvme_ctrl_get_by_path()

[Christoph Hellwig]

On Fri, Sep 04, 2020 at 09:54:48AM -0600, Logan Gunthorpe wrote:
> 
> 
> On 2020-09-03 8:39 p.m., Chaitanya Kulkarni wrote:
> > Right now nvme_ctrl_get_by_path() accepts ctrl path, based on that it
> > opens a file and calls nvme_get_ctrl(). In order to take module
> > refcount it is important to distinguish the error between file_open()
> > and module file ops check so that we can unwind the code in the caller
> > nvmet_passthru_ctrl_enable() in the error path.
> > 
> > Rename nvme_ctrl_get_by_path() -> nvme_ctrl_get_by_file() and lift
> > the file opening and error handling in the caller so that we can unwind
> > appropriately in the error path.
> 
> I still don't really like this idea. No need to keep a reference to a
> whole other file.

We could still lift the filp_open into the caller, but drop the file
reference right after we got the controller reference.