Re: [PATCH 0/2] nfsd: improvements for wake_up_bit/var

["NeilBrown" <neilb@xxxxxxx>]

On Fri, 30 Aug 2024, Santosh Pradhan wrote:
> Hi Neil,
> Do we need a barrier in nfs4_disable_swap() as well ?
> 
> 10830         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
> 10831         clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
> >>> HERE>>>>
> 10832         wake_up_var(&clp->cl_state);

Probably but that is in fs/nfs/, not fs/nfsd/.

Thanks,
NeilBrown


> 
> Regards,
> Santosh
> 
> On Fri, Aug 30, 2024 at 12:37 PM NeilBrown <neilb@xxxxxxx> wrote:
> >
> > I've been digging into wake_up_bit and wake_up_var recently.  There are
> > a lot of places where the required barriers aren't quite right.
> >
> > This patch fixes them up for nfsd.  The bugs are mostly minor, though
> > the rp_locked on might be a credible problem on weakly ordered hosts
> > (e.g.  power64).
> >
> > NeilBrown
> >
> >  [PATCH 1/2] nfsd: use clear_and_wake_up_bit()
> >  [PATCH 2/2] nfsd: avoid races with wake_up_var()
> >
>