Re: [PATCH v2 2/4] cxl/pci: Cleanup 'sanitize' to always poll

[Dan Williams <dan.j.williams@intel.com>]

Davidlohr Bueso wrote:
> On Fri, 29 Sep 2023, Dan Williams wrote:
> 
> >In preparation for fixing the init/teardown of the 'sanitize' workqueue
> >and sysfs notification mechanism, arrange for cxl_mbox_sanitize_work()
> >to be the single location where the sysfs attribute is notified. With
> >that change there is no distinction between polled mode and interrupt
> >mode. All the interrupt does is accelerate the polling interval.
> >
> >The change to check for "mds->security.sanitize_node" under the lock is
> >there to ensure that the interrupt, the work routine and the
> >setup/teardown code can all have a consistent view of the registered
> >notifier and the workqueue state. I.e. the expectation is that the
> >interrupt is live past the point that the sanitize sysfs attribute is
> >published, and it may race teardown, so it must be consulted under a
> >lock.
> 
> That makes sense, but this is currently under hardirq, so we'd need the
> threaded flavor instead to take the mutex.

Yes I missed that, will fix.