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f4d15fb6f9
Provide a couple of functions to allow cleaner handling of signals in a
kernel service. They are:
(1) rxrpc_kernel_get_rtt()
This allows the kernel service to find out the RTT time for a call, so
as to better judge how large a timeout to employ.
Note, though, that whilst this returns a value in nanoseconds, the
timeouts can only actually be in jiffies.
(2) rxrpc_kernel_check_life()
This returns a number that is updated when ACKs are received from the
peer (notably including PING RESPONSE ACKs which we can elicit by
sending PING ACKs to see if the call still exists on the server).
The caller should compare the numbers of two calls to see if the call
is still alive.
These can be used to provide an extending timeout rather than returning
immediately in the case that a signal occurs that would otherwise abort an
RPC operation. The timeout would be extended if the server is still
responsive and the call is still apparently alive on the server.
For most operations this isn't that necessary - but for FS.StoreData it is:
OpenAFS writes the data to storage as it comes in without making a backup,
so if we immediately abort it when partially complete on a CTRL+C, say, we
have no idea of the state of the file after the abort.
Signed-off-by: David Howells <dhowells@redhat.com>
75 lines
2.8 KiB
C
75 lines
2.8 KiB
C
/* RxRPC kernel service interface definitions
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _NET_RXRPC_H
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#define _NET_RXRPC_H
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#include <linux/rxrpc.h>
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struct key;
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struct sock;
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struct socket;
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struct rxrpc_call;
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/*
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* Call completion condition (state == RXRPC_CALL_COMPLETE).
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*/
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enum rxrpc_call_completion {
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RXRPC_CALL_SUCCEEDED, /* - Normal termination */
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RXRPC_CALL_REMOTELY_ABORTED, /* - call aborted by peer */
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RXRPC_CALL_LOCALLY_ABORTED, /* - call aborted locally on error or close */
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RXRPC_CALL_LOCAL_ERROR, /* - call failed due to local error */
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RXRPC_CALL_NETWORK_ERROR, /* - call terminated by network error */
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NR__RXRPC_CALL_COMPLETIONS
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};
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typedef void (*rxrpc_notify_rx_t)(struct sock *, struct rxrpc_call *,
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unsigned long);
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typedef void (*rxrpc_notify_end_tx_t)(struct sock *, struct rxrpc_call *,
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unsigned long);
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typedef void (*rxrpc_notify_new_call_t)(struct sock *, struct rxrpc_call *,
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unsigned long);
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typedef void (*rxrpc_discard_new_call_t)(struct rxrpc_call *, unsigned long);
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typedef void (*rxrpc_user_attach_call_t)(struct rxrpc_call *, unsigned long);
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void rxrpc_kernel_new_call_notification(struct socket *,
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rxrpc_notify_new_call_t,
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rxrpc_discard_new_call_t);
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struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *,
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struct sockaddr_rxrpc *,
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struct key *,
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unsigned long,
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s64,
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gfp_t,
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rxrpc_notify_rx_t,
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bool);
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int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
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struct msghdr *, size_t,
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rxrpc_notify_end_tx_t);
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int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *,
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void *, size_t, size_t *, bool, u32 *, u16 *);
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bool rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *,
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u32, int, const char *);
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void rxrpc_kernel_end_call(struct socket *, struct rxrpc_call *);
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void rxrpc_kernel_get_peer(struct socket *, struct rxrpc_call *,
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struct sockaddr_rxrpc *);
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u64 rxrpc_kernel_get_rtt(struct socket *, struct rxrpc_call *);
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int rxrpc_kernel_charge_accept(struct socket *, rxrpc_notify_rx_t,
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rxrpc_user_attach_call_t, unsigned long, gfp_t);
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void rxrpc_kernel_set_tx_length(struct socket *, struct rxrpc_call *, s64);
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int rxrpc_kernel_retry_call(struct socket *, struct rxrpc_call *,
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struct sockaddr_rxrpc *, struct key *);
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int rxrpc_kernel_check_call(struct socket *, struct rxrpc_call *,
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enum rxrpc_call_completion *, u32 *);
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u32 rxrpc_kernel_check_life(struct socket *, struct rxrpc_call *);
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#endif /* _NET_RXRPC_H */
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