On Fri, May 18, 2018 at 08:19:58AM +0800, Ming Lei wrote: > On Wed, May 16, 2018 at 08:20:31PM -0600, Keith Busch wrote: > > Hi Ming, > > > > I'm developing the answers in code the issues you raised. It will just > > take a moment to complete flushing those out. In the meantime just want > > to point out why I think block/011 isn't a real test. > > > > On Thu, May 17, 2018 at 07:10:59AM +0800, Ming Lei wrote: > > > All simulation in block/011 may happen in reality. > > > > If this test actually simulates reality, then the following one line > > patch (plus explanation for why) would be a real "fix" as this is very > > successful in passing block/011. :) > > > > --- > > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > > index 1faa32cd07da..dcc5746304c4 100644 > > --- a/drivers/nvme/host/pci.c > > +++ b/drivers/nvme/host/pci.c > > @@ -2118,6 +2118,12 @@ static int nvme_pci_enable(struct nvme_dev *dev) > > > > if (pci_enable_device_mem(pdev)) > > return result; > > + /* > > + * blktests block/011 disables the device without the driver knowing. > > + * We'll just enable the device twice to get the enable_cnt > 1 > > + * so that the test's disabling does absolutely nothing. > > + */ > > + pci_enable_device_mem(pdev); > > What I think block/011 is helpful is that it can trigger IO timeout > during reset, which can be triggered in reality too. > > That is one big problem of NVMe driver, IMO. > > And this patch does fix this issue, together other timeout related > races. BTW, the above patch may not be enough to 'fix' this NVMe issue, I guess you may have to figure out another one to remove fault-injection, or at least disable io-timeout-fail on NVMe. Thanks, Ming
