From: Chuck Lever chuck.lever@oracle.com
Engineers at Hammerspace noticed that sometimes mounting with "xprtsec=tls" hangs for a minute or so, and then times out, even when the NFS server is reachable and responsive.
kTLS shuts off data_ready callbacks if strp->msg_ready is set to mitigate data_ready callbacks when a full TLS record is not yet ready to be read from the socket.
Normally msg_ready is clear when the first TLS record arrives on a socket. However, I observed that sometimes tls_setsockopt() sets strp->msg_ready, and that prevents forward progress because tls_data_ready() becomes a no-op.
Moreover, Jakub says: "If there's a full record queued at the time when [tlshd] passes the socket back to the kernel, it's up to the reader to read the already queued data out." So SunRPC cannot expect a data_ready call when ingress data is already waiting.
Add an explicit poll after SunRPC's upper transport is set up to pick up any data that arrived after the TLS handshake but before transport set-up is complete.
Reported-by: Steve Sears sjs@hammerspace.com Suggested-by: Jakub Kacinski kuba@kernel.org Fixes: 75eb6af7acdf ("SUNRPC: Add a TCP-with-TLS RPC transport class") Tested-by: Mike Snitzer snitzer@kernel.org Reviewed-by: Mike Snitzer snitzer@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com --- net/sunrpc/xprtsock.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 83cc095846d3..4b10ecf4c265 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2740,6 +2740,11 @@ static void xs_tcp_tls_setup_socket(struct work_struct *work) } rpc_shutdown_client(lower_clnt);
+ /* Check for ingress data that arrived before the socket's + * ->data_ready callback was set up. + */ + xs_poll_check_readable(upper_transport); + out_unlock: current_restore_flags(pflags, PF_MEMALLOC); upper_transport->clnt = NULL;