forked from luck/tmp_suning_uos_patched
174cd4b1e5
Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
1082 lines
30 KiB
C
1082 lines
30 KiB
C
/* Client connection-specific management code.
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*
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* Copyright (C) 2016 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 Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*
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*
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* Client connections need to be cached for a little while after they've made a
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* call so as to handle retransmitted DATA packets in case the server didn't
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* receive the final ACK or terminating ABORT we sent it.
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*
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* Client connections can be in one of a number of cache states:
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*
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* (1) INACTIVE - The connection is not held in any list and may not have been
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* exposed to the world. If it has been previously exposed, it was
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* discarded from the idle list after expiring.
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*
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* (2) WAITING - The connection is waiting for the number of client conns to
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* drop below the maximum capacity. Calls may be in progress upon it from
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* when it was active and got culled.
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*
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* The connection is on the rxrpc_waiting_client_conns list which is kept
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* in to-be-granted order. Culled conns with waiters go to the back of
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* the queue just like new conns.
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*
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* (3) ACTIVE - The connection has at least one call in progress upon it, it
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* may freely grant available channels to new calls and calls may be
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* waiting on it for channels to become available.
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*
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* The connection is on the rxrpc_active_client_conns list which is kept
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* in activation order for culling purposes.
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*
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* rxrpc_nr_active_client_conns is held incremented also.
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*
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* (4) CULLED - The connection got summarily culled to try and free up
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* capacity. Calls currently in progress on the connection are allowed to
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* continue, but new calls will have to wait. There can be no waiters in
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* this state - the conn would have to go to the WAITING state instead.
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*
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* (5) IDLE - The connection has no calls in progress upon it and must have
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* been exposed to the world (ie. the EXPOSED flag must be set). When it
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* expires, the EXPOSED flag is cleared and the connection transitions to
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* the INACTIVE state.
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*
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* The connection is on the rxrpc_idle_client_conns list which is kept in
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* order of how soon they'll expire.
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*
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* There are flags of relevance to the cache:
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*
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* (1) EXPOSED - The connection ID got exposed to the world. If this flag is
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* set, an extra ref is added to the connection preventing it from being
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* reaped when it has no calls outstanding. This flag is cleared and the
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* ref dropped when a conn is discarded from the idle list.
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*
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* This allows us to move terminal call state retransmission to the
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* connection and to discard the call immediately we think it is done
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* with. It also give us a chance to reuse the connection.
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*
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* (2) DONT_REUSE - The connection should be discarded as soon as possible and
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* should not be reused. This is set when an exclusive connection is used
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* or a call ID counter overflows.
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*
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* The caching state may only be changed if the cache lock is held.
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*
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* There are two idle client connection expiry durations. If the total number
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* of connections is below the reap threshold, we use the normal duration; if
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* it's above, we use the fast duration.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/slab.h>
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#include <linux/idr.h>
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#include <linux/timer.h>
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#include <linux/sched/signal.h>
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#include "ar-internal.h"
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__read_mostly unsigned int rxrpc_max_client_connections = 1000;
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__read_mostly unsigned int rxrpc_reap_client_connections = 900;
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__read_mostly unsigned int rxrpc_conn_idle_client_expiry = 2 * 60 * HZ;
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__read_mostly unsigned int rxrpc_conn_idle_client_fast_expiry = 2 * HZ;
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static unsigned int rxrpc_nr_client_conns;
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static unsigned int rxrpc_nr_active_client_conns;
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static __read_mostly bool rxrpc_kill_all_client_conns;
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static DEFINE_SPINLOCK(rxrpc_client_conn_cache_lock);
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static DEFINE_SPINLOCK(rxrpc_client_conn_discard_mutex);
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static LIST_HEAD(rxrpc_waiting_client_conns);
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static LIST_HEAD(rxrpc_active_client_conns);
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static LIST_HEAD(rxrpc_idle_client_conns);
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/*
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* We use machine-unique IDs for our client connections.
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*/
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DEFINE_IDR(rxrpc_client_conn_ids);
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static DEFINE_SPINLOCK(rxrpc_conn_id_lock);
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static void rxrpc_cull_active_client_conns(void);
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static void rxrpc_discard_expired_client_conns(struct work_struct *);
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static DECLARE_DELAYED_WORK(rxrpc_client_conn_reap,
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rxrpc_discard_expired_client_conns);
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/*
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* Get a connection ID and epoch for a client connection from the global pool.
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* The connection struct pointer is then recorded in the idr radix tree. The
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* epoch doesn't change until the client is rebooted (or, at least, unless the
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* module is unloaded).
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*/
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static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn,
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gfp_t gfp)
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{
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int id;
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_enter("");
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idr_preload(gfp);
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spin_lock(&rxrpc_conn_id_lock);
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id = idr_alloc_cyclic(&rxrpc_client_conn_ids, conn,
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1, 0x40000000, GFP_NOWAIT);
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if (id < 0)
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goto error;
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spin_unlock(&rxrpc_conn_id_lock);
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idr_preload_end();
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conn->proto.epoch = rxrpc_epoch;
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conn->proto.cid = id << RXRPC_CIDSHIFT;
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set_bit(RXRPC_CONN_HAS_IDR, &conn->flags);
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_leave(" [CID %x]", conn->proto.cid);
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return 0;
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error:
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spin_unlock(&rxrpc_conn_id_lock);
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idr_preload_end();
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_leave(" = %d", id);
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return id;
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}
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/*
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* Release a connection ID for a client connection from the global pool.
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*/
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static void rxrpc_put_client_connection_id(struct rxrpc_connection *conn)
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{
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if (test_bit(RXRPC_CONN_HAS_IDR, &conn->flags)) {
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spin_lock(&rxrpc_conn_id_lock);
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idr_remove(&rxrpc_client_conn_ids,
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conn->proto.cid >> RXRPC_CIDSHIFT);
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spin_unlock(&rxrpc_conn_id_lock);
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}
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}
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/*
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* Destroy the client connection ID tree.
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*/
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void rxrpc_destroy_client_conn_ids(void)
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{
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struct rxrpc_connection *conn;
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int id;
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if (!idr_is_empty(&rxrpc_client_conn_ids)) {
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idr_for_each_entry(&rxrpc_client_conn_ids, conn, id) {
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pr_err("AF_RXRPC: Leaked client conn %p {%d}\n",
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conn, atomic_read(&conn->usage));
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}
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BUG();
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}
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idr_destroy(&rxrpc_client_conn_ids);
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}
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/*
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* Allocate a client connection.
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*/
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static struct rxrpc_connection *
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rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp)
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{
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struct rxrpc_connection *conn;
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int ret;
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_enter("");
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conn = rxrpc_alloc_connection(gfp);
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if (!conn) {
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_leave(" = -ENOMEM");
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return ERR_PTR(-ENOMEM);
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}
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atomic_set(&conn->usage, 1);
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if (cp->exclusive)
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__set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
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conn->params = *cp;
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conn->out_clientflag = RXRPC_CLIENT_INITIATED;
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conn->state = RXRPC_CONN_CLIENT;
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ret = rxrpc_get_client_connection_id(conn, gfp);
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if (ret < 0)
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goto error_0;
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ret = rxrpc_init_client_conn_security(conn);
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if (ret < 0)
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goto error_1;
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ret = conn->security->prime_packet_security(conn);
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if (ret < 0)
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goto error_2;
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write_lock(&rxrpc_connection_lock);
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list_add_tail(&conn->proc_link, &rxrpc_connection_proc_list);
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write_unlock(&rxrpc_connection_lock);
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/* We steal the caller's peer ref. */
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cp->peer = NULL;
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rxrpc_get_local(conn->params.local);
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key_get(conn->params.key);
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trace_rxrpc_conn(conn, rxrpc_conn_new_client, atomic_read(&conn->usage),
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__builtin_return_address(0));
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trace_rxrpc_client(conn, -1, rxrpc_client_alloc);
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_leave(" = %p", conn);
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return conn;
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error_2:
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conn->security->clear(conn);
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error_1:
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rxrpc_put_client_connection_id(conn);
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error_0:
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kfree(conn);
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_leave(" = %d", ret);
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return ERR_PTR(ret);
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}
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/*
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* Determine if a connection may be reused.
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*/
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static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
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{
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int id_cursor, id, distance, limit;
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if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags))
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goto dont_reuse;
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if (conn->proto.epoch != rxrpc_epoch)
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goto mark_dont_reuse;
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/* The IDR tree gets very expensive on memory if the connection IDs are
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* widely scattered throughout the number space, so we shall want to
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* kill off connections that, say, have an ID more than about four
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* times the maximum number of client conns away from the current
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* allocation point to try and keep the IDs concentrated.
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*/
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id_cursor = idr_get_cursor(&rxrpc_client_conn_ids);
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id = conn->proto.cid >> RXRPC_CIDSHIFT;
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distance = id - id_cursor;
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if (distance < 0)
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distance = -distance;
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limit = max(rxrpc_max_client_connections * 4, 1024U);
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if (distance > limit)
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goto mark_dont_reuse;
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return true;
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mark_dont_reuse:
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set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
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dont_reuse:
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return false;
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}
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/*
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* Create or find a client connection to use for a call.
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*
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* If we return with a connection, the call will be on its waiting list. It's
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* left to the caller to assign a channel and wake up the call.
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*/
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static int rxrpc_get_client_conn(struct rxrpc_call *call,
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struct rxrpc_conn_parameters *cp,
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struct sockaddr_rxrpc *srx,
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gfp_t gfp)
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{
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struct rxrpc_connection *conn, *candidate = NULL;
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struct rxrpc_local *local = cp->local;
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struct rb_node *p, **pp, *parent;
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long diff;
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int ret = -ENOMEM;
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_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
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cp->peer = rxrpc_lookup_peer(cp->local, srx, gfp);
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if (!cp->peer)
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goto error;
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/* If the connection is not meant to be exclusive, search the available
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* connections to see if the connection we want to use already exists.
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*/
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if (!cp->exclusive) {
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_debug("search 1");
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spin_lock(&local->client_conns_lock);
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p = local->client_conns.rb_node;
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while (p) {
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conn = rb_entry(p, struct rxrpc_connection, client_node);
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#define cmp(X) ((long)conn->params.X - (long)cp->X)
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diff = (cmp(peer) ?:
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cmp(key) ?:
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cmp(security_level));
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#undef cmp
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if (diff < 0) {
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p = p->rb_left;
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} else if (diff > 0) {
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p = p->rb_right;
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} else {
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if (rxrpc_may_reuse_conn(conn) &&
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rxrpc_get_connection_maybe(conn))
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goto found_extant_conn;
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/* The connection needs replacing. It's better
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* to effect that when we have something to
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* replace it with so that we don't have to
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* rebalance the tree twice.
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*/
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break;
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}
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}
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spin_unlock(&local->client_conns_lock);
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}
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/* There wasn't a connection yet or we need an exclusive connection.
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* We need to create a candidate and then potentially redo the search
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* in case we're racing with another thread also trying to connect on a
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* shareable connection.
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*/
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_debug("new conn");
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candidate = rxrpc_alloc_client_connection(cp, gfp);
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if (IS_ERR(candidate)) {
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ret = PTR_ERR(candidate);
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goto error_peer;
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}
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/* Add the call to the new connection's waiting list in case we're
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* going to have to wait for the connection to come live. It's our
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* connection, so we want first dibs on the channel slots. We would
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* normally have to take channel_lock but we do this before anyone else
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* can see the connection.
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*/
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list_add_tail(&call->chan_wait_link, &candidate->waiting_calls);
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if (cp->exclusive) {
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call->conn = candidate;
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call->security_ix = candidate->security_ix;
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_leave(" = 0 [exclusive %d]", candidate->debug_id);
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return 0;
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}
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/* Publish the new connection for userspace to find. We need to redo
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* the search before doing this lest we race with someone else adding a
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* conflicting instance.
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*/
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_debug("search 2");
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spin_lock(&local->client_conns_lock);
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pp = &local->client_conns.rb_node;
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parent = NULL;
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while (*pp) {
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parent = *pp;
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conn = rb_entry(parent, struct rxrpc_connection, client_node);
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#define cmp(X) ((long)conn->params.X - (long)candidate->params.X)
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diff = (cmp(peer) ?:
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cmp(key) ?:
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cmp(security_level));
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#undef cmp
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if (diff < 0) {
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pp = &(*pp)->rb_left;
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} else if (diff > 0) {
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pp = &(*pp)->rb_right;
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} else {
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if (rxrpc_may_reuse_conn(conn) &&
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rxrpc_get_connection_maybe(conn))
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goto found_extant_conn;
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/* The old connection is from an outdated epoch. */
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_debug("replace conn");
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clear_bit(RXRPC_CONN_IN_CLIENT_CONNS, &conn->flags);
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rb_replace_node(&conn->client_node,
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&candidate->client_node,
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&local->client_conns);
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trace_rxrpc_client(conn, -1, rxrpc_client_replace);
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goto candidate_published;
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}
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}
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_debug("new conn");
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rb_link_node(&candidate->client_node, parent, pp);
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rb_insert_color(&candidate->client_node, &local->client_conns);
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candidate_published:
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set_bit(RXRPC_CONN_IN_CLIENT_CONNS, &candidate->flags);
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call->conn = candidate;
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call->security_ix = candidate->security_ix;
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spin_unlock(&local->client_conns_lock);
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_leave(" = 0 [new %d]", candidate->debug_id);
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return 0;
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|
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/* We come here if we found a suitable connection already in existence.
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* Discard any candidate we may have allocated, and try to get a
|
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* channel on this one.
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*/
|
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found_extant_conn:
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_debug("found conn");
|
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spin_unlock(&local->client_conns_lock);
|
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|
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if (candidate) {
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trace_rxrpc_client(candidate, -1, rxrpc_client_duplicate);
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rxrpc_put_connection(candidate);
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candidate = NULL;
|
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}
|
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|
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spin_lock(&conn->channel_lock);
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call->conn = conn;
|
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call->security_ix = conn->security_ix;
|
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list_add(&call->chan_wait_link, &conn->waiting_calls);
|
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spin_unlock(&conn->channel_lock);
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_leave(" = 0 [extant %d]", conn->debug_id);
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return 0;
|
|
|
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error_peer:
|
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rxrpc_put_peer(cp->peer);
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cp->peer = NULL;
|
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error:
|
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_leave(" = %d", ret);
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return ret;
|
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}
|
|
|
|
/*
|
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* Activate a connection.
|
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*/
|
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static void rxrpc_activate_conn(struct rxrpc_connection *conn)
|
|
{
|
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trace_rxrpc_client(conn, -1, rxrpc_client_to_active);
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conn->cache_state = RXRPC_CONN_CLIENT_ACTIVE;
|
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rxrpc_nr_active_client_conns++;
|
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list_move_tail(&conn->cache_link, &rxrpc_active_client_conns);
|
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}
|
|
|
|
/*
|
|
* Attempt to animate a connection for a new call.
|
|
*
|
|
* If it's not exclusive, the connection is in the endpoint tree, and we're in
|
|
* the conn's list of those waiting to grab a channel. There is, however, a
|
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* limit on the number of live connections allowed at any one time, so we may
|
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* have to wait for capacity to become available.
|
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*
|
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* Note that a connection on the waiting queue might *also* have active
|
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* channels if it has been culled to make space and then re-requested by a new
|
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* call.
|
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*/
|
|
static void rxrpc_animate_client_conn(struct rxrpc_connection *conn)
|
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{
|
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unsigned int nr_conns;
|
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|
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_enter("%d,%d", conn->debug_id, conn->cache_state);
|
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|
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if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE)
|
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goto out;
|
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|
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spin_lock(&rxrpc_client_conn_cache_lock);
|
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|
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nr_conns = rxrpc_nr_client_conns;
|
|
if (!test_and_set_bit(RXRPC_CONN_COUNTED, &conn->flags)) {
|
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trace_rxrpc_client(conn, -1, rxrpc_client_count);
|
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rxrpc_nr_client_conns = nr_conns + 1;
|
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}
|
|
|
|
switch (conn->cache_state) {
|
|
case RXRPC_CONN_CLIENT_ACTIVE:
|
|
case RXRPC_CONN_CLIENT_WAITING:
|
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break;
|
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|
|
case RXRPC_CONN_CLIENT_INACTIVE:
|
|
case RXRPC_CONN_CLIENT_CULLED:
|
|
case RXRPC_CONN_CLIENT_IDLE:
|
|
if (nr_conns >= rxrpc_max_client_connections)
|
|
goto wait_for_capacity;
|
|
goto activate_conn;
|
|
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
out_unlock:
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
out:
|
|
_leave(" [%d]", conn->cache_state);
|
|
return;
|
|
|
|
activate_conn:
|
|
_debug("activate");
|
|
rxrpc_activate_conn(conn);
|
|
goto out_unlock;
|
|
|
|
wait_for_capacity:
|
|
_debug("wait");
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting);
|
|
conn->cache_state = RXRPC_CONN_CLIENT_WAITING;
|
|
list_move_tail(&conn->cache_link, &rxrpc_waiting_client_conns);
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Deactivate a channel.
|
|
*/
|
|
static void rxrpc_deactivate_one_channel(struct rxrpc_connection *conn,
|
|
unsigned int channel)
|
|
{
|
|
struct rxrpc_channel *chan = &conn->channels[channel];
|
|
|
|
rcu_assign_pointer(chan->call, NULL);
|
|
conn->active_chans &= ~(1 << channel);
|
|
}
|
|
|
|
/*
|
|
* Assign a channel to the call at the front of the queue and wake the call up.
|
|
* We don't increment the callNumber counter until this number has been exposed
|
|
* to the world.
|
|
*/
|
|
static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
|
|
unsigned int channel)
|
|
{
|
|
struct rxrpc_channel *chan = &conn->channels[channel];
|
|
struct rxrpc_call *call = list_entry(conn->waiting_calls.next,
|
|
struct rxrpc_call, chan_wait_link);
|
|
u32 call_id = chan->call_counter + 1;
|
|
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate);
|
|
|
|
write_lock_bh(&call->state_lock);
|
|
call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
|
|
write_unlock_bh(&call->state_lock);
|
|
|
|
rxrpc_see_call(call);
|
|
list_del_init(&call->chan_wait_link);
|
|
conn->active_chans |= 1 << channel;
|
|
call->peer = rxrpc_get_peer(conn->params.peer);
|
|
call->cid = conn->proto.cid | channel;
|
|
call->call_id = call_id;
|
|
|
|
_net("CONNECT call %08x:%08x as call %d on conn %d",
|
|
call->cid, call->call_id, call->debug_id, conn->debug_id);
|
|
|
|
/* Paired with the read barrier in rxrpc_wait_for_channel(). This
|
|
* orders cid and epoch in the connection wrt to call_id without the
|
|
* need to take the channel_lock.
|
|
*
|
|
* We provisionally assign a callNumber at this point, but we don't
|
|
* confirm it until the call is about to be exposed.
|
|
*
|
|
* TODO: Pair with a barrier in the data_ready handler when that looks
|
|
* at the call ID through a connection channel.
|
|
*/
|
|
smp_wmb();
|
|
chan->call_id = call_id;
|
|
rcu_assign_pointer(chan->call, call);
|
|
wake_up(&call->waitq);
|
|
}
|
|
|
|
/*
|
|
* Assign channels and callNumbers to waiting calls with channel_lock
|
|
* held by caller.
|
|
*/
|
|
static void rxrpc_activate_channels_locked(struct rxrpc_connection *conn)
|
|
{
|
|
u8 avail, mask;
|
|
|
|
switch (conn->cache_state) {
|
|
case RXRPC_CONN_CLIENT_ACTIVE:
|
|
mask = RXRPC_ACTIVE_CHANS_MASK;
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
|
|
while (!list_empty(&conn->waiting_calls) &&
|
|
(avail = ~conn->active_chans,
|
|
avail &= mask,
|
|
avail != 0))
|
|
rxrpc_activate_one_channel(conn, __ffs(avail));
|
|
}
|
|
|
|
/*
|
|
* Assign channels and callNumbers to waiting calls.
|
|
*/
|
|
static void rxrpc_activate_channels(struct rxrpc_connection *conn)
|
|
{
|
|
_enter("%d", conn->debug_id);
|
|
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_activate_chans);
|
|
|
|
if (conn->active_chans == RXRPC_ACTIVE_CHANS_MASK)
|
|
return;
|
|
|
|
spin_lock(&conn->channel_lock);
|
|
rxrpc_activate_channels_locked(conn);
|
|
spin_unlock(&conn->channel_lock);
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* Wait for a callNumber and a channel to be granted to a call.
|
|
*/
|
|
static int rxrpc_wait_for_channel(struct rxrpc_call *call, gfp_t gfp)
|
|
{
|
|
int ret = 0;
|
|
|
|
_enter("%d", call->debug_id);
|
|
|
|
if (!call->call_id) {
|
|
DECLARE_WAITQUEUE(myself, current);
|
|
|
|
if (!gfpflags_allow_blocking(gfp)) {
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
add_wait_queue_exclusive(&call->waitq, &myself);
|
|
for (;;) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
if (call->call_id)
|
|
break;
|
|
if (signal_pending(current)) {
|
|
ret = -ERESTARTSYS;
|
|
break;
|
|
}
|
|
schedule();
|
|
}
|
|
remove_wait_queue(&call->waitq, &myself);
|
|
__set_current_state(TASK_RUNNING);
|
|
}
|
|
|
|
/* Paired with the write barrier in rxrpc_activate_one_channel(). */
|
|
smp_rmb();
|
|
|
|
out:
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* find a connection for a call
|
|
* - called in process context with IRQs enabled
|
|
*/
|
|
int rxrpc_connect_call(struct rxrpc_call *call,
|
|
struct rxrpc_conn_parameters *cp,
|
|
struct sockaddr_rxrpc *srx,
|
|
gfp_t gfp)
|
|
{
|
|
int ret;
|
|
|
|
_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
|
|
|
|
rxrpc_discard_expired_client_conns(NULL);
|
|
rxrpc_cull_active_client_conns();
|
|
|
|
ret = rxrpc_get_client_conn(call, cp, srx, gfp);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
rxrpc_animate_client_conn(call->conn);
|
|
rxrpc_activate_channels(call->conn);
|
|
|
|
ret = rxrpc_wait_for_channel(call, gfp);
|
|
if (ret < 0)
|
|
rxrpc_disconnect_client_call(call);
|
|
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Note that a connection is about to be exposed to the world. Once it is
|
|
* exposed, we maintain an extra ref on it that stops it from being summarily
|
|
* discarded before it's (a) had a chance to deal with retransmission and (b)
|
|
* had a chance at re-use (the per-connection security negotiation is
|
|
* expensive).
|
|
*/
|
|
static void rxrpc_expose_client_conn(struct rxrpc_connection *conn,
|
|
unsigned int channel)
|
|
{
|
|
if (!test_and_set_bit(RXRPC_CONN_EXPOSED, &conn->flags)) {
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_exposed);
|
|
rxrpc_get_connection(conn);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Note that a call, and thus a connection, is about to be exposed to the
|
|
* world.
|
|
*/
|
|
void rxrpc_expose_client_call(struct rxrpc_call *call)
|
|
{
|
|
unsigned int channel = call->cid & RXRPC_CHANNELMASK;
|
|
struct rxrpc_connection *conn = call->conn;
|
|
struct rxrpc_channel *chan = &conn->channels[channel];
|
|
|
|
if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
|
|
/* Mark the call ID as being used. If the callNumber counter
|
|
* exceeds ~2 billion, we kill the connection after its
|
|
* outstanding calls have finished so that the counter doesn't
|
|
* wrap.
|
|
*/
|
|
chan->call_counter++;
|
|
if (chan->call_counter >= INT_MAX)
|
|
set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
|
|
rxrpc_expose_client_conn(conn, channel);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Disconnect a client call.
|
|
*/
|
|
void rxrpc_disconnect_client_call(struct rxrpc_call *call)
|
|
{
|
|
unsigned int channel = call->cid & RXRPC_CHANNELMASK;
|
|
struct rxrpc_connection *conn = call->conn;
|
|
struct rxrpc_channel *chan = &conn->channels[channel];
|
|
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect);
|
|
call->conn = NULL;
|
|
|
|
spin_lock(&conn->channel_lock);
|
|
|
|
/* Calls that have never actually been assigned a channel can simply be
|
|
* discarded. If the conn didn't get used either, it will follow
|
|
* immediately unless someone else grabs it in the meantime.
|
|
*/
|
|
if (!list_empty(&call->chan_wait_link)) {
|
|
_debug("call is waiting");
|
|
ASSERTCMP(call->call_id, ==, 0);
|
|
ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags));
|
|
list_del_init(&call->chan_wait_link);
|
|
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_chan_unstarted);
|
|
|
|
/* We must deactivate or idle the connection if it's now
|
|
* waiting for nothing.
|
|
*/
|
|
spin_lock(&rxrpc_client_conn_cache_lock);
|
|
if (conn->cache_state == RXRPC_CONN_CLIENT_WAITING &&
|
|
list_empty(&conn->waiting_calls) &&
|
|
!conn->active_chans)
|
|
goto idle_connection;
|
|
goto out;
|
|
}
|
|
|
|
ASSERTCMP(rcu_access_pointer(chan->call), ==, call);
|
|
|
|
/* If a client call was exposed to the world, we save the result for
|
|
* retransmission.
|
|
*
|
|
* We use a barrier here so that the call number and abort code can be
|
|
* read without needing to take a lock.
|
|
*
|
|
* TODO: Make the incoming packet handler check this and handle
|
|
* terminal retransmission without requiring access to the call.
|
|
*/
|
|
if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
|
|
_debug("exposed %u,%u", call->call_id, call->abort_code);
|
|
__rxrpc_disconnect_call(conn, call);
|
|
}
|
|
|
|
/* See if we can pass the channel directly to another call. */
|
|
if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE &&
|
|
!list_empty(&conn->waiting_calls)) {
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass);
|
|
rxrpc_activate_one_channel(conn, channel);
|
|
goto out_2;
|
|
}
|
|
|
|
/* Things are more complex and we need the cache lock. We might be
|
|
* able to simply idle the conn or it might now be lurking on the wait
|
|
* list. It might even get moved back to the active list whilst we're
|
|
* waiting for the lock.
|
|
*/
|
|
spin_lock(&rxrpc_client_conn_cache_lock);
|
|
|
|
switch (conn->cache_state) {
|
|
case RXRPC_CONN_CLIENT_ACTIVE:
|
|
if (list_empty(&conn->waiting_calls)) {
|
|
rxrpc_deactivate_one_channel(conn, channel);
|
|
if (!conn->active_chans) {
|
|
rxrpc_nr_active_client_conns--;
|
|
goto idle_connection;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass);
|
|
rxrpc_activate_one_channel(conn, channel);
|
|
goto out;
|
|
|
|
case RXRPC_CONN_CLIENT_CULLED:
|
|
rxrpc_deactivate_one_channel(conn, channel);
|
|
ASSERT(list_empty(&conn->waiting_calls));
|
|
if (!conn->active_chans)
|
|
goto idle_connection;
|
|
goto out;
|
|
|
|
case RXRPC_CONN_CLIENT_WAITING:
|
|
rxrpc_deactivate_one_channel(conn, channel);
|
|
goto out;
|
|
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
out:
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
out_2:
|
|
spin_unlock(&conn->channel_lock);
|
|
rxrpc_put_connection(conn);
|
|
_leave("");
|
|
return;
|
|
|
|
idle_connection:
|
|
/* As no channels remain active, the connection gets deactivated
|
|
* immediately or moved to the idle list for a short while.
|
|
*/
|
|
if (test_bit(RXRPC_CONN_EXPOSED, &conn->flags)) {
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_to_idle);
|
|
conn->idle_timestamp = jiffies;
|
|
conn->cache_state = RXRPC_CONN_CLIENT_IDLE;
|
|
list_move_tail(&conn->cache_link, &rxrpc_idle_client_conns);
|
|
if (rxrpc_idle_client_conns.next == &conn->cache_link &&
|
|
!rxrpc_kill_all_client_conns)
|
|
queue_delayed_work(rxrpc_workqueue,
|
|
&rxrpc_client_conn_reap,
|
|
rxrpc_conn_idle_client_expiry);
|
|
} else {
|
|
trace_rxrpc_client(conn, channel, rxrpc_client_to_inactive);
|
|
conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE;
|
|
list_del_init(&conn->cache_link);
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Clean up a dead client connection.
|
|
*/
|
|
static struct rxrpc_connection *
|
|
rxrpc_put_one_client_conn(struct rxrpc_connection *conn)
|
|
{
|
|
struct rxrpc_connection *next = NULL;
|
|
struct rxrpc_local *local = conn->params.local;
|
|
unsigned int nr_conns;
|
|
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_cleanup);
|
|
|
|
if (test_bit(RXRPC_CONN_IN_CLIENT_CONNS, &conn->flags)) {
|
|
spin_lock(&local->client_conns_lock);
|
|
if (test_and_clear_bit(RXRPC_CONN_IN_CLIENT_CONNS,
|
|
&conn->flags))
|
|
rb_erase(&conn->client_node, &local->client_conns);
|
|
spin_unlock(&local->client_conns_lock);
|
|
}
|
|
|
|
rxrpc_put_client_connection_id(conn);
|
|
|
|
ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_INACTIVE);
|
|
|
|
if (test_bit(RXRPC_CONN_COUNTED, &conn->flags)) {
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_uncount);
|
|
spin_lock(&rxrpc_client_conn_cache_lock);
|
|
nr_conns = --rxrpc_nr_client_conns;
|
|
|
|
if (nr_conns < rxrpc_max_client_connections &&
|
|
!list_empty(&rxrpc_waiting_client_conns)) {
|
|
next = list_entry(rxrpc_waiting_client_conns.next,
|
|
struct rxrpc_connection, cache_link);
|
|
rxrpc_get_connection(next);
|
|
rxrpc_activate_conn(next);
|
|
}
|
|
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
}
|
|
|
|
rxrpc_kill_connection(conn);
|
|
if (next)
|
|
rxrpc_activate_channels(next);
|
|
|
|
/* We need to get rid of the temporary ref we took upon next, but we
|
|
* can't call rxrpc_put_connection() recursively.
|
|
*/
|
|
return next;
|
|
}
|
|
|
|
/*
|
|
* Clean up a dead client connections.
|
|
*/
|
|
void rxrpc_put_client_conn(struct rxrpc_connection *conn)
|
|
{
|
|
const void *here = __builtin_return_address(0);
|
|
int n;
|
|
|
|
do {
|
|
n = atomic_dec_return(&conn->usage);
|
|
trace_rxrpc_conn(conn, rxrpc_conn_put_client, n, here);
|
|
if (n > 0)
|
|
return;
|
|
ASSERTCMP(n, >=, 0);
|
|
|
|
conn = rxrpc_put_one_client_conn(conn);
|
|
} while (conn);
|
|
}
|
|
|
|
/*
|
|
* Kill the longest-active client connections to make room for new ones.
|
|
*/
|
|
static void rxrpc_cull_active_client_conns(void)
|
|
{
|
|
struct rxrpc_connection *conn;
|
|
unsigned int nr_conns = rxrpc_nr_client_conns;
|
|
unsigned int nr_active, limit;
|
|
|
|
_enter("");
|
|
|
|
ASSERTCMP(nr_conns, >=, 0);
|
|
if (nr_conns < rxrpc_max_client_connections) {
|
|
_leave(" [ok]");
|
|
return;
|
|
}
|
|
limit = rxrpc_reap_client_connections;
|
|
|
|
spin_lock(&rxrpc_client_conn_cache_lock);
|
|
nr_active = rxrpc_nr_active_client_conns;
|
|
|
|
while (nr_active > limit) {
|
|
ASSERT(!list_empty(&rxrpc_active_client_conns));
|
|
conn = list_entry(rxrpc_active_client_conns.next,
|
|
struct rxrpc_connection, cache_link);
|
|
ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_ACTIVE);
|
|
|
|
if (list_empty(&conn->waiting_calls)) {
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_to_culled);
|
|
conn->cache_state = RXRPC_CONN_CLIENT_CULLED;
|
|
list_del_init(&conn->cache_link);
|
|
} else {
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting);
|
|
conn->cache_state = RXRPC_CONN_CLIENT_WAITING;
|
|
list_move_tail(&conn->cache_link,
|
|
&rxrpc_waiting_client_conns);
|
|
}
|
|
|
|
nr_active--;
|
|
}
|
|
|
|
rxrpc_nr_active_client_conns = nr_active;
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
ASSERTCMP(nr_active, >=, 0);
|
|
_leave(" [culled]");
|
|
}
|
|
|
|
/*
|
|
* Discard expired client connections from the idle list. Each conn in the
|
|
* idle list has been exposed and holds an extra ref because of that.
|
|
*
|
|
* This may be called from conn setup or from a work item so cannot be
|
|
* considered non-reentrant.
|
|
*/
|
|
static void rxrpc_discard_expired_client_conns(struct work_struct *work)
|
|
{
|
|
struct rxrpc_connection *conn;
|
|
unsigned long expiry, conn_expires_at, now;
|
|
unsigned int nr_conns;
|
|
bool did_discard = false;
|
|
|
|
_enter("%c", work ? 'w' : 'n');
|
|
|
|
if (list_empty(&rxrpc_idle_client_conns)) {
|
|
_leave(" [empty]");
|
|
return;
|
|
}
|
|
|
|
/* Don't double up on the discarding */
|
|
if (!spin_trylock(&rxrpc_client_conn_discard_mutex)) {
|
|
_leave(" [already]");
|
|
return;
|
|
}
|
|
|
|
/* We keep an estimate of what the number of conns ought to be after
|
|
* we've discarded some so that we don't overdo the discarding.
|
|
*/
|
|
nr_conns = rxrpc_nr_client_conns;
|
|
|
|
next:
|
|
spin_lock(&rxrpc_client_conn_cache_lock);
|
|
|
|
if (list_empty(&rxrpc_idle_client_conns))
|
|
goto out;
|
|
|
|
conn = list_entry(rxrpc_idle_client_conns.next,
|
|
struct rxrpc_connection, cache_link);
|
|
ASSERT(test_bit(RXRPC_CONN_EXPOSED, &conn->flags));
|
|
|
|
if (!rxrpc_kill_all_client_conns) {
|
|
/* If the number of connections is over the reap limit, we
|
|
* expedite discard by reducing the expiry timeout. We must,
|
|
* however, have at least a short grace period to be able to do
|
|
* final-ACK or ABORT retransmission.
|
|
*/
|
|
expiry = rxrpc_conn_idle_client_expiry;
|
|
if (nr_conns > rxrpc_reap_client_connections)
|
|
expiry = rxrpc_conn_idle_client_fast_expiry;
|
|
|
|
conn_expires_at = conn->idle_timestamp + expiry;
|
|
|
|
now = READ_ONCE(jiffies);
|
|
if (time_after(conn_expires_at, now))
|
|
goto not_yet_expired;
|
|
}
|
|
|
|
trace_rxrpc_client(conn, -1, rxrpc_client_discard);
|
|
if (!test_and_clear_bit(RXRPC_CONN_EXPOSED, &conn->flags))
|
|
BUG();
|
|
conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE;
|
|
list_del_init(&conn->cache_link);
|
|
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
|
|
/* When we cleared the EXPOSED flag, we took on responsibility for the
|
|
* reference that that had on the usage count. We deal with that here.
|
|
* If someone re-sets the flag and re-gets the ref, that's fine.
|
|
*/
|
|
rxrpc_put_connection(conn);
|
|
did_discard = true;
|
|
nr_conns--;
|
|
goto next;
|
|
|
|
not_yet_expired:
|
|
/* The connection at the front of the queue hasn't yet expired, so
|
|
* schedule the work item for that point if we discarded something.
|
|
*
|
|
* We don't worry if the work item is already scheduled - it can look
|
|
* after rescheduling itself at a later time. We could cancel it, but
|
|
* then things get messier.
|
|
*/
|
|
_debug("not yet");
|
|
if (!rxrpc_kill_all_client_conns)
|
|
queue_delayed_work(rxrpc_workqueue,
|
|
&rxrpc_client_conn_reap,
|
|
conn_expires_at - now);
|
|
|
|
out:
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
spin_unlock(&rxrpc_client_conn_discard_mutex);
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* Preemptively destroy all the client connection records rather than waiting
|
|
* for them to time out
|
|
*/
|
|
void __exit rxrpc_destroy_all_client_connections(void)
|
|
{
|
|
_enter("");
|
|
|
|
spin_lock(&rxrpc_client_conn_cache_lock);
|
|
rxrpc_kill_all_client_conns = true;
|
|
spin_unlock(&rxrpc_client_conn_cache_lock);
|
|
|
|
cancel_delayed_work(&rxrpc_client_conn_reap);
|
|
|
|
if (!queue_delayed_work(rxrpc_workqueue, &rxrpc_client_conn_reap, 0))
|
|
_debug("destroy: queue failed");
|
|
|
|
_leave("");
|
|
}
|