Re: [RFC 01/20] iommu/iommufd: Add /dev/iommu core

[Jason Gunthorpe]

On Fri, Oct 15, 2021 at 09:18:06AM +0000, Liu, Yi L wrote:

> >   Acquire from the xarray is
> >    rcu_lock()
> >    ioas = xa_load()
> >    if (ioas)
> >       if (down_read_trylock(&ioas->destroying_lock))
> 
> all good suggestions, will refine accordingly. Here destroying_lock is a
> rw_semaphore. right? Since down_read_trylock() accepts a rwsem.

Yes, you probably need a sleeping lock

Jason