On Sun, Jun 25, 2023 at 08:26:48AM +0800, Ming Lei wrote: > Yeah, but you can't remove the gap at all with start_freeze, that said > the current code has to live with the situation of new mapping change > and old request with old mapping. > > Actually I considered to handle this kind of situation before, one approach > is to reuse the bio steal logic taken in nvme mpath: > > 1) for FS IO, re-submit bios, meantime free request > > 2) for PT request, simply fail it > > It could be a bit violent for 2) even though REQ_FAILFAST_DRIVER is > always set for PT request, but not see any better approach for handling > PT request. I think that's acceptable for PT requests, or any request that doesn't have a bio. I tried something similiar a while back that was almost working, but I neither never posted it, or it's in that window when infradead lost all the emails. :( Anyway, for the pci controller, I think I see the problem you're fixing. When reset_work fails, we used to do the mark dead + unquieces via "nvme_kill_queues()", which doesn't exist anymore, but I think your scenario worked back then. Currently a failed nvme_reset_work simply marks them dead without the unquiesce. Would it be enough to just bring that unqueisce behavior back? --- diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index b027e5e3f4acb..8eaa954aa6ed4 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2778,6 +2778,7 @@ static void nvme_reset_work(struct work_struct *work) nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING); nvme_dev_disable(dev, true); nvme_mark_namespaces_dead(&dev->ctrl); + nvme_unquiesce_io_queues(&dev->ctrl); nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD); } --
