> On Mon, 2023-10-30 at 12:08 +1100, NeilBrown wrote:
> > Rather than using svc_get() and svc_put() to hold a stable reference to
> > the nfsd_svc for netlink lookups, simply hold the mutex for the entire
> > time.
> >
> > The "entire" time isn't very long, and the mutex is not often contented.
> >
> > This makes way for use to remove the refcounts of svc, which is more
> > confusing than useful.
> >
> > Signed-off-by: NeilBrown <neilb@xxxxxxx>
> > ---
> > fs/nfsd/nfsctl.c | 9 +++------
> > 1 file changed, 3 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> > index d78ae4452946..8f644f1d157c 100644
> > --- a/fs/nfsd/nfsctl.c
> > +++ b/fs/nfsd/nfsctl.c
> > @@ -1515,11 +1515,10 @@ int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb)
> > int ret = -ENODEV;
> >
> > mutex_lock(&nfsd_mutex);
> > - if (nn->nfsd_serv) {
> > - svc_get(nn->nfsd_serv);
> > + if (nn->nfsd_serv)
> > ret = 0;
> > - }
> > - mutex_unlock(&nfsd_mutex);
> > + else
> > + mutex_unlock(&nfsd_mutex);
> >
> > return ret;
> > }
> > @@ -1691,8 +1690,6 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
> > */
> > int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb)
> > {
> > - mutex_lock(&nfsd_mutex);
> > - nfsd_put(sock_net(cb->skb->sk));
> > mutex_unlock(&nfsd_mutex);
> >
> > return 0;
>
> (cc'ing Lorenzo since he wrote this)
>
> I think Lorenzo did it this way originally, and I convinced him to take
> a reference instead. This should be fine though.
yep, the idea was to avoid grabbing the mutex and dump the refcount instead but
I think it is fine.
Regards,
Lorenzo
>
> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Attachment:
signature.asc
Description: PGP signature
