Commit a902f3de authored by Anna Schumaker's avatar Anna Schumaker
Browse files

SUNRPC: Create a helper function for accessing the rpc_clnt's xprt_switch 



This function takes the necessary rcu read lock to dereference the
client's rpc_xprt_switch and bump the reference count so it doesn't
disappear underneath us before returning. This does mean that callers
are responsible for calling xprt_switch_put() on the returned object
when they are done with it.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 5f1e77b2

net/sunrpc/clnt.c

+21 −13
Original line number Diff line number Diff line
@@ -797,15 +797,24 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt, 
}

EXPORT_SYMBOL_GPL(rpc_switch_client_transport);



static

int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi,

			     void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps))

static struct rpc_xprt_switch *rpc_clnt_xprt_switch_get(struct rpc_clnt *clnt)

{

	struct rpc_xprt_switch *xps;



	rcu_read_lock();

	xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));

	rcu_read_unlock();



	return xps;

}



static

int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi,

			     void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps))

{

	struct rpc_xprt_switch *xps;



	xps = rpc_clnt_xprt_switch_get(clnt);

	if (xps == NULL)

		return -EAGAIN;

	func(xpi, xps);
@@ -2206,9 +2215,7 @@ call_connect_status(struct rpc_task *task) 
			struct rpc_xprt *saved = task->tk_xprt;

			struct rpc_xprt_switch *xps;



			rcu_read_lock();

			xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));

			rcu_read_unlock();

			xps = rpc_clnt_xprt_switch_get(clnt);

			if (xps->xps_nxprts > 1) {

				long value;
@@ -3251,22 +3258,23 @@ void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt) 
{

	struct rpc_xprt_switch *xps;



	rcu_read_lock();

	xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);

	rcu_read_unlock();

	xps = rpc_clnt_xprt_switch_get(clnt);

	xprt_set_online_locked(xprt, xps);

	xprt_switch_put(xps);

}



void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)

{

	struct rpc_xprt_switch *xps;



	if (rpc_clnt_xprt_switch_has_addr(clnt,

		(const struct sockaddr *)&xprt->addr)) {

		return rpc_clnt_xprt_set_online(clnt, xprt);

	}

	rcu_read_lock();

	rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),

				 xprt);

	rcu_read_unlock();



	xps = rpc_clnt_xprt_switch_get(clnt);

	rpc_xprt_switch_add_xprt(xps, xprt);

	xprt_switch_put(xps);

}

EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);