sunrpc: Allow xprt->ops->timer method to sleep

The transport lock is needed to protect the xprt_adjust_cwnd() call
in xs_udp_timer, but it is not necessary for accessing the
rq_reply_bytes_recvd or tk_status fields. It is correct to sublimate
the lock into UDP's xs_udp_timer method, where it is required.

The ->timer method has to take the transport lock if needed, but it
can now sleep safely, or even call back into the RPC scheduler.

This is more a clean-up than a fix, but the "issue" was introduced
by my transport switch patches back in 2005.

Fixes: 46c0ee8bc4 ("RPC: separate xprt_timer implementations")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2017-02-08 17:00:51 -05:00 committed by Anna Schumaker
parent 9a5c63e9c4
commit b977b644cc
2 changed files with 2 additions and 2 deletions

View file

@ -897,13 +897,11 @@ static void xprt_timer(struct rpc_task *task)
return;
dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
spin_lock_bh(&xprt->transport_lock);
if (!req->rq_reply_bytes_recvd) {
if (xprt->ops->timer)
xprt->ops->timer(xprt, task);
} else
task->tk_status = 0;
spin_unlock_bh(&xprt->transport_lock);
}
/**

View file

@ -1739,7 +1739,9 @@ static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t
*/
static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
{
spin_lock_bh(&xprt->transport_lock);
xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
spin_unlock_bh(&xprt->transport_lock);
}
static unsigned short xs_get_random_port(void)