On Wed, 2017-02-08 at 17:00 -0500, Chuck Lever wrote: > 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: 46c0ee8bc4ad ("RPC: separate xprt_timer implementations") > Signed-off-by: Chuck Lever > --- >  net/sunrpc/xprt.c     |    2 -- >  net/sunrpc/xprtsock.c |    2 ++ >  2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c > index 9a6be03..b530a28 100644 > --- a/net/sunrpc/xprt.c > +++ b/net/sunrpc/xprt.c > @@ -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); >  } >   >  /** > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > index af392d9..d9bb644 100644 > --- a/net/sunrpc/xprtsock.c > +++ b/net/sunrpc/xprtsock.c > @@ -1734,7 +1734,9 @@ 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) > Thanks! Good cleanup... Trond -- Trond Myklebust Principal System Architect 4300 El Camino Real | Suite 100 Los Altos, CA  94022 W: 650-422-3800 C: 801-921-4583  www.primarydata.com NrybXǧv^)޺{.n+{ٚ{ayʇڙ,jfh/oScڳ9u&jw(階ݢj"mzޖfh~m