[PATCHv2 blktests 2/2] nvme: add test for writing to file-ns just after disabling it

[Daniel Wagner]

On Thu, Dec 05, 2024 at 03:10:23PM +0530, Nilay Shroff wrote:
> >> +	img="$(mktemp /tmp/blk_img_XXXXXX)"
> >> +	dd if=/dev/urandom of="$img" bs=512 count=1 status=none
> > 
> > why can't we just use the standard block device backed ns ?
> Using standard block device would also work however using the file backed block 
> device would be handy in case user doesn't have a spare standard block device 
> available which could be used for writing a random junk to it.

If I understood Chaitanya correctly, he would prefer to use the existing
helpers to setup the backend, either file or block. If so, I am also on
board with this idea, not to hard code backend into the test. We have
moved this into the helpers so that it's a test parameter.

> OK I think maybe there's a confusion, let me clarify one thing here: We're
> *not* disabling AEN functionality but only masking the ns-changed async even 
> notification from target and I believe that's perfectly legal per spec. I 
> shall update the comment added in the test case to avoid this confusion. 
> 
> > Can this be an exception for some reason ?
> > 
> > Shinichiro, Daniel any thoughts ?

I haven't really checked what the spec says on this topic. Nilay, could
you give a pointer, so I don't spend too much time trying to find the
right spot in the spec. Thanks!

> > +unsigned int ns_disable_error_inject;
> > +module_param(ns_disable_error_inject, int, 0644);
> > +MODULE_PARM_DESC(ns_disable_error_inject,
> > +                "delay xa_erase() in ns-disable path in seconds 
> > (default 0)");
> > +

Please no. This type of debugging/testing interface is hard to use IMO.
It should be in one of the psydo FS, sysfs, configfs or debugfs if
really needed.

Daniel