5.4-stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown neilb@suse.de
[ Upstream commit 6258cf25d5e3155c3219ab5a79b970eef7996356 ]
Prior to the commit identified below, call_transmit_status() would handle -EPERM and other errors related to an unreachable server by falling through to call_status() which added a 3-second delay and handled the failure as a timeout.
Since that commit, call_transmit_status() falls through to handle_bind(). For UDP this moves straight on to handle_connect() and handle_transmit() so we immediately retransmit - and likely get the same error.
This results in an indefinite loop in __rpc_execute() which triggers a soft-lockup warning.
For the errors that indicate an unreachable server, call_transmit_status() should fall back to call_status() as it did before. This cannot cause the thundering herd that the previous patch was avoiding, as the call_status() will insert a delay.
Fixes: ed7dc973bd91 ("SUNRPC: Prevent thundering herd when the socket is not connected") Signed-off-by: NeilBrown neilb@suse.de Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/clnt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 2e08876bf8564..f689c7b0c304d 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -2236,12 +2236,13 @@ call_transmit_status(struct rpc_task *task) task->tk_action = call_transmit; task->tk_status = 0; break; - case -ECONNREFUSED: case -EHOSTDOWN: case -ENETDOWN: case -EHOSTUNREACH: case -ENETUNREACH: case -EPERM: + break; + case -ECONNREFUSED: if (RPC_IS_SOFTCONN(task)) { if (!task->tk_msg.rpc_proc->p_proc) trace_xprt_ping(task->tk_xprt,