diff options
author | David Howells <dhowells@redhat.com> | 2018-11-12 22:33:22 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-11-15 11:35:40 -0800 |
commit | 7150ceaacb27f7b3bf494e72cd4be4e11612dfff (patch) | |
tree | cdb1fb191dc649c0f1563045fe17ef0630690b2c /net/rxrpc/af_rxrpc.c | |
parent | ebcd210e93b2a984b7a7b82d45f7f0d21b7ec2d2 (diff) |
rxrpc: Fix life check
The life-checking function, which is used by kAFS to make sure that a call
is still live in the event of a pending signal, only samples the received
packet serial number counter; it doesn't actually provoke a change in the
counter, rather relying on the server to happen to give us a packet in the
time window.
Fix this by adding a function to force a ping to be transmitted.
kAFS then keeps track of whether there's been a stall, and if so, uses the
new function to ping the server, resetting the timeout to allow the reply
to come back.
If there's a stall, a ping and the call is *still* stalled in the same
place after another period, then the call will be aborted.
Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Fixes: f4d15fb6f99a ("rxrpc: Provide functions for allowing cleaner handling of signals")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rxrpc/af_rxrpc.c')
-rw-r--r-- | net/rxrpc/af_rxrpc.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 64362d078da8..a2522f9d71e2 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -375,17 +375,36 @@ EXPORT_SYMBOL(rxrpc_kernel_end_call); * getting ACKs from the server. Returns a number representing the life state * which can be compared to that returned by a previous call. * - * If this is a client call, ping ACKs will be sent to the server to find out - * whether it's still responsive and whether the call is still alive on the - * server. + * If the life state stalls, rxrpc_kernel_probe_life() should be called and + * then 2RTT waited. */ -u32 rxrpc_kernel_check_life(struct socket *sock, struct rxrpc_call *call) +u32 rxrpc_kernel_check_life(const struct socket *sock, + const struct rxrpc_call *call) { return call->acks_latest; } EXPORT_SYMBOL(rxrpc_kernel_check_life); /** + * rxrpc_kernel_probe_life - Poke the peer to see if it's still alive + * @sock: The socket the call is on + * @call: The call to check + * + * In conjunction with rxrpc_kernel_check_life(), allow a kernel service to + * find out whether a call is still alive by pinging it. This should cause the + * life state to be bumped in about 2*RTT. + * + * The must be called in TASK_RUNNING state on pain of might_sleep() objecting. + */ +void rxrpc_kernel_probe_life(struct socket *sock, struct rxrpc_call *call) +{ + rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false, + rxrpc_propose_ack_ping_for_check_life); + rxrpc_send_ack_packet(call, true, NULL); +} +EXPORT_SYMBOL(rxrpc_kernel_probe_life); + +/** * rxrpc_kernel_get_epoch - Retrieve the epoch value from a call. * @sock: The socket the call is on * @call: The call to query |