Re: [PATCH v6 1/8] SUNRPC: introduce helpers for reference countedrpcbind clients

[Stanislav Kinsbursky]

25.10.2011 15:16, Trond Myklebust ÐÐÑÐÑ:
> On Tue, 2011-10-25 at 14:16 +0300, Stanislav Kinsbursky wrote:
> > v6:
> > 1) added write memory barrier to rpcb_set_local to make sure, that rpcbind
> > clients become valid before rpcb_users assignment
> > 2) explicitly set rpcb_users to 1 instead of incrementing it (looks clearer from
> > my pow).
> >
> > v5: fixed races with rpcb_users in rpcb_get_local()
> >
> > This helpers will be used for dynamical creation and destruction of rpcbind
> > clients.
> > Variable rpcb_users is actually a counter of lauched RPC services. If rpcbind
> > clients has been created already, then we just increase rpcb_users.
> >
> > Signed-off-by: Stanislav Kinsbursky<skinsbursky@xxxxxxxxxxxxx>
> >
> > ---
> >   net/sunrpc/rpcb_clnt.c |   54 ++++++++++++++++++++++++++++++++++++++++++++++++
> >   1 files changed, 54 insertions(+), 0 deletions(-)
> >
> > diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
> > index e45d2fb..9fcdb42 100644
> > --- a/net/sunrpc/rpcb_clnt.c
> > +++ b/net/sunrpc/rpcb_clnt.c
> > @@ -114,6 +114,9 @@ static struct rpc_program	rpcb_program;
> >   static struct rpc_clnt *	rpcb_local_clnt;
> >   static struct rpc_clnt *	rpcb_local_clnt4;
> >
> > +DEFINE_SPINLOCK(rpcb_clnt_lock);
> > +unsigned int			rpcb_users;
> > +
> >   struct rpcbind_args {
> >   	struct rpc_xprt *	r_xprt;
> >
> > @@ -161,6 +164,57 @@ static void rpcb_map_release(void *data)
> >   	kfree(map);
> >   }
> >
> > +static int rpcb_get_local(void)
> > +{
> > +	int cnt;
> > +
> > +	spin_lock(&rpcb_clnt_lock);
> > +	if (rpcb_users)
> > +		rpcb_users++;
> > +	cnt = rpcb_users;
> > +	spin_unlock(&rpcb_clnt_lock);
> > +
> > +	return cnt;
> > +}
> > +
> > +void rpcb_put_local(void)
> > +{
> > +	struct rpc_clnt *clnt = rpcb_local_clnt;
> > +	struct rpc_clnt *clnt4 = rpcb_local_clnt4;
> > +	int shutdown;
> > +
> > +	spin_lock(&rpcb_clnt_lock);
> > +	if (--rpcb_users == 0) {
> > +		rpcb_local_clnt = NULL;
> > +		rpcb_local_clnt4 = NULL;
> > +	}
> > +	shutdown = !rpcb_users;
> > +	spin_unlock(&rpcb_clnt_lock);
> > +
> > +	if (shutdown) {
> > +		/*
> > +		 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
> > +		 */
> > +		if (clnt4)
> > +			rpc_shutdown_client(clnt4);
> > +		if (clnt)
> > +			rpc_shutdown_client(clnt);
> > +	}
> > +	return;
>
> I'm removing this before applying...
Sorry, but I don't understand what exactly you are removing, and why?

> > +}
> > +


--
Best regards,
Stanislav Kinsbursky
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