From e908bcf4f1a271e7c264dcbffc5881ced8bfacee Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 4 Oct 2018 09:54:29 +0100 Subject: rxrpc: Allow the reply time to be obtained on a client call Allow the epoch value to be queried on a server connection. This is in the rxrpc header of every packet for use in routing and is derived from the client's state. It's also not supposed to change unless the client gets restarted. AFS can make use of this information to deduce whether a fileserver has been restarted because the fileserver makes client calls to the filesystem driver's cache manager to send notifications (ie. callback breaks) about conflicting changes from other clients. These convey the fileserver's own epoch value back to the filesystem. Signed-off-by: David Howells --- net/rxrpc/af_rxrpc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'net/rxrpc') diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 2fdd276f6842..013dbcb052e5 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -385,6 +385,20 @@ u32 rxrpc_kernel_check_life(struct socket *sock, struct rxrpc_call *call) } EXPORT_SYMBOL(rxrpc_kernel_check_life); +/** + * rxrpc_kernel_get_epoch - Retrieve the epoch value from a call. + * @sock: The socket the call is on + * @call: The call to query + * + * Allow a kernel service to retrieve the epoch value from a service call to + * see if the client at the other end rebooted. + */ +u32 rxrpc_kernel_get_epoch(struct socket *sock, struct rxrpc_call *call) +{ + return call->conn->proto.epoch; +} +EXPORT_SYMBOL(rxrpc_kernel_get_epoch); + /** * rxrpc_kernel_check_call - Check a call's state * @sock: The socket the call is on -- cgit