[PATCH 08/11] nvmet-fc: take tgtport reference only once

[Daniel Wagner]

On Fri, Feb 28, 2025 at 08:34:51AM +0100, Hannes Reinecke wrote:
> On 2/26/25 19:46, Daniel Wagner wrote:
> > The reference counting code can be simplified. Instead taking a tgtport
> > refrerence at the beginning of nvmet_fc_alloc_hostport and put it back
> > if not a new hostport object is allocated, only take it when a new
> > hostport object is allocated.
> > 
> Can it really?
> Main point of this operation is that 'tgtport' isn't going away during while
> we're figuring out whether we need it.
> 
> With this patch it means that

The tgtport is not going away. nvmet_fc_alloc_hostport can only be
called with reference on tgtport being hold:

nvmet_fc_rcv_ls_req
  nvmet_fc_tgtport_get(tgtport)
  nvmet_fc_handle_ls_rqst_work
    nvmet_fc_handle_ls_rqst
      nvmet_fc_ls_create_association
        nvmet_fc_alloc_target_assoc
          nvmet_fc_alloc_hostport

The goal with this patch here is to make it simpler to read where we
take a ref. IMO, there is not really anything gained by the existing
logic, though I agree it's not obvious that the tgtport is not going
away. Would it be okay to add a comment?