Re: [PATCH 1/5] nvme-fc: don't hold rport lock when putting ctrl

[Daniel Wagner <dwagner@suse.de>]

On Tue, Nov 04, 2025 at 11:51:09AM +0100, Hannes Reinecke wrote:
> On 10/28/25 16:26, Daniel Wagner wrote:
> > nvme_fc_ctrl_put can acquire the rport lock when freeing the
> > ctrl object:
> > 
> > nvme_fc_ctrl_put
> >    nvme_fc_ctrl_free
> >      spin_lock_irqsave(rport->lock)
> > 
> > Thus we can't hold the rport lock when calling nvme_fc_ctrl_put.
> > 
> > Signed-off-by: Daniel Wagner <wagi@kernel.org>
> > ---
> >   drivers/nvme/host/fc.c | 2 ++
> >   1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> > index 03987f497a5b..2c0ea843ae57 100644
> > --- a/drivers/nvme/host/fc.c
> > +++ b/drivers/nvme/host/fc.c
> > @@ -1488,7 +1488,9 @@ nvme_fc_match_disconn_ls(struct nvme_fc_rport *rport,
> >   		if (ret)
> >   			/* leave the ctrl get reference */
> >   			break;
> > +		spin_unlock_irqrestore(&rport->lock, flags);
> >   		nvme_fc_ctrl_put(ctrl);
> > +		spin_lock_irqsave(&rport->lock, flags);
> >   	}
> >   	spin_unlock_irqrestore(&rport->lock, flags);
> > 
> In theory, yes.

I hit this in practice ;)