eb9b9d2275
Check that the client conns cache is empty before module removal and bug if not, listing any offending connections that are still present. Unfortunately, if there are connections still around, then the transport socket is still unexpectedly open and active, so we can't just unallocate the connections. Signed-off-by: David Howells <dhowells@redhat.com>
114 lines
3.0 KiB
C
114 lines
3.0 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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#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 "ar-internal.h"
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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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/*
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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 is changed if this wraps.
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*
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* TODO: 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 need to retire
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* connections that have, say, an ID more than four times the maximum number of
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* client conns away from the current allocation point to try and keep the IDs
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* concentrated. We will also need to retire connections from an old epoch.
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*/
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int rxrpc_get_client_connection_id(struct rxrpc_connection *conn, gfp_t gfp)
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{
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u32 epoch;
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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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epoch = rxrpc_epoch;
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/* We could use idr_alloc_cyclic() here, but we really need to know
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* when the thing wraps so that we can advance the epoch.
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*/
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if (rxrpc_client_conn_ids.cur == 0)
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rxrpc_client_conn_ids.cur = 1;
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id = idr_alloc(&rxrpc_client_conn_ids, conn,
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rxrpc_client_conn_ids.cur, 0x40000000, GFP_NOWAIT);
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if (id < 0) {
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if (id != -ENOSPC)
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goto error;
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id = idr_alloc(&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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epoch++;
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rxrpc_epoch = epoch;
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}
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rxrpc_client_conn_ids.cur = id + 1;
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spin_unlock(&rxrpc_conn_id_lock);
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idr_preload_end();
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conn->proto.epoch = 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:%x]", epoch, 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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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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