From: Trond Myklebust trondmy@gmail.com

mainline inclusion from mainline-5.2-rc1 commit e4ec48d3cc6139f4c1a934ff25d440cd4d50279f category: bugfix bugzilla: 51818 CVE: NA

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If a soft NFSv4 request is sent, then we don't need it to time out unless the connection breaks. The reason is that as long as the connection is unbroken, the protocol states that the server is not allowed to drop the request. IOW: as long as the connection remains unbroken, the client may assume that all transmitted RPC requests are being processed by the server, and that retransmissions and timeouts of those requests are unwarranted.

Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Zhang Changzhong zhangchangzhong@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- net/sunrpc/clnt.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index b560ae4aef440..227bf32f2476b 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -2229,6 +2229,15 @@ call_timeout(struct rpc_task *task) }

if (RPC_IS_SOFT(task)) { + /* + * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has + * been sent, it should time out only if the transport + * connection gets terminally broken. + */ + if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) && + rpc_check_connected(task->tk_rqstp)) + return; + if (clnt->cl_chatty) { printk(KERN_NOTICE "%s: server %s not responding, timed out\n", clnt->cl_program->name,