[PATCH blktests v3 1/2] nvme/rc: fix nvme device readiness check after _nvme_connect_subsys

[Shinichiro Kawasaki]

On Aug 18, 2023 / 10:53, Daniel Wagner wrote:
> On Fri, Aug 18, 2023 at 01:40:56PM +0900, Shin'ichiro Kawasaki wrote:
> > The helper function _nvme_connect_subsys() creates a nvme device. It may
> > take some time after the function call until the device gets ready for
> > I/O. So it is expected that the test cases call _find_nvme_dev() after
> > _nvme_connect_subsys() before I/O. _find_nvme_dev() returns the path of
> > the created device, and it also waits for uuid and wwid sysfs attributes
> > of the created device get ready. This wait works as the wait for the
> > device I/O readiness.
> > 
> > However, this wait by _find_nvme_dev() has two problems. The first
> > problem is missing call of _find_nvme_dev(). The test case nvme/047
> > calls _nvme_connect_subsys() twice, but _find_nvme_dev() is called only
> > for the first _nvme_connect_subsys() call. This causes too early I/O to
> > the device with tcp transport [1]. Fix this by moving the wait for the
> > device readiness from _find_nvme_dev() to _nvme_connect_subsys(). Also
> > add --no-wait option to _nvme_connect_subsys(). It allows to skip the
> > wait in _nvmet_passthru_target_connect() which has its own wait for
> > device readiness.
> > 
> > The second problem is wrong paths for the sysfs attributes. The paths
> > do not include namespace index, so the check for the attributes always
> > fail. Still _find_nvme_dev() does 1 second wait and allows the device
> > get ready for I/O in most cases, but this is not intended behavior.
> > Fix this by checking sysfs paths with the namespace index. Get list of
> > namespace indices for the sub-system and do the check for all indices.
> > 
> > On top of the checks for sysfs attributes, add 'udevadm settle' and a
> > check for the created device file. These ensures that the create device
> > is ready for I/O.
> > 
> > [1] https://lore.kernel.org/linux-block/CAHj4cs9GNohGUjohNw93jrr8JGNcRYC-ienAZz+sa7az1RK77w@mail.gmail.com/
> > 
> > Fixes: c766fccf3aff ("Make the NVMe tests more reliable")
> > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki at wdc.com>
> 
> just a minor nitpick but feel free to add:
> 
> Reviewed-by: Daniel Wagner <dwagner at suse.de>

Thanks for the comment. I've applied this with the suggested change.