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254 lines
7.1 KiB
254 lines
7.1 KiB
/* |
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* Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved. |
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* |
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* This software is available to you under a choice of one of two |
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* licenses. You may choose to be licensed under the terms of the GNU |
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* General Public License (GPL) Version 2, available from the file |
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* COPYING in the main directory of this source tree, or the |
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* OpenIB.org BSD license below: |
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* |
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* Redistribution and use in source and binary forms, with or |
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* without modification, are permitted provided that the following |
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* conditions are met: |
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* |
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* - Redistributions of source code must retain the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer. |
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* |
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* - Redistributions in binary form must reproduce the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer in the documentation and/or other materials |
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* provided with the distribution. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
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* SOFTWARE. |
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* |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/in.h> |
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#include <net/net_namespace.h> |
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#include <net/netns/generic.h> |
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#include <linux/ipv6.h> |
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#include "rds_single_path.h" |
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#include "rds.h" |
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#include "loop.h" |
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static DEFINE_SPINLOCK(loop_conns_lock); |
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static LIST_HEAD(loop_conns); |
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static atomic_t rds_loop_unloading = ATOMIC_INIT(0); |
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static void rds_loop_set_unloading(void) |
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{ |
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atomic_set(&rds_loop_unloading, 1); |
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} |
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static bool rds_loop_is_unloading(struct rds_connection *conn) |
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{ |
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return atomic_read(&rds_loop_unloading) != 0; |
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} |
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/* |
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* This 'loopback' transport is a special case for flows that originate |
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* and terminate on the same machine. |
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* |
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* Connection build-up notices if the destination address is thought of |
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* as a local address by a transport. At that time it decides to use the |
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* loopback transport instead of the bound transport of the sending socket. |
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* |
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* The loopback transport's sending path just hands the sent rds_message |
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* straight to the receiving path via an embedded rds_incoming. |
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*/ |
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/* |
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* Usually a message transits both the sender and receiver's conns as it |
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* flows to the receiver. In the loopback case, though, the receive path |
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* is handed the sending conn so the sense of the addresses is reversed. |
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*/ |
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static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm, |
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unsigned int hdr_off, unsigned int sg, |
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unsigned int off) |
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{ |
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struct scatterlist *sgp = &rm->data.op_sg[sg]; |
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int ret = sizeof(struct rds_header) + |
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be32_to_cpu(rm->m_inc.i_hdr.h_len); |
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/* Do not send cong updates to loopback */ |
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if (rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) { |
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rds_cong_map_updated(conn->c_fcong, ~(u64) 0); |
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ret = min_t(int, ret, sgp->length - conn->c_xmit_data_off); |
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goto out; |
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} |
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BUG_ON(hdr_off || sg || off); |
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rds_inc_init(&rm->m_inc, conn, &conn->c_laddr); |
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/* For the embedded inc. Matching put is in loop_inc_free() */ |
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rds_message_addref(rm); |
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rds_recv_incoming(conn, &conn->c_laddr, &conn->c_faddr, &rm->m_inc, |
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GFP_KERNEL); |
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rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence), |
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NULL); |
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rds_inc_put(&rm->m_inc); |
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out: |
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return ret; |
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} |
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/* |
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* See rds_loop_xmit(). Since our inc is embedded in the rm, we |
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* make sure the rm lives at least until the inc is done. |
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*/ |
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static void rds_loop_inc_free(struct rds_incoming *inc) |
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{ |
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struct rds_message *rm = container_of(inc, struct rds_message, m_inc); |
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rds_message_put(rm); |
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} |
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/* we need to at least give the thread something to succeed */ |
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static int rds_loop_recv_path(struct rds_conn_path *cp) |
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{ |
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return 0; |
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} |
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struct rds_loop_connection { |
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struct list_head loop_node; |
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struct rds_connection *conn; |
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}; |
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/* |
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* Even the loopback transport needs to keep track of its connections, |
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* so it can call rds_conn_destroy() on them on exit. N.B. there are |
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* 1+ loopback addresses (127.*.*.*) so it's not a bug to have |
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* multiple loopback conns allocated, although rather useless. |
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*/ |
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static int rds_loop_conn_alloc(struct rds_connection *conn, gfp_t gfp) |
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{ |
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struct rds_loop_connection *lc; |
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unsigned long flags; |
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lc = kzalloc(sizeof(struct rds_loop_connection), gfp); |
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if (!lc) |
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return -ENOMEM; |
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INIT_LIST_HEAD(&lc->loop_node); |
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lc->conn = conn; |
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conn->c_transport_data = lc; |
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spin_lock_irqsave(&loop_conns_lock, flags); |
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list_add_tail(&lc->loop_node, &loop_conns); |
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spin_unlock_irqrestore(&loop_conns_lock, flags); |
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return 0; |
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} |
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static void rds_loop_conn_free(void *arg) |
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{ |
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struct rds_loop_connection *lc = arg; |
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unsigned long flags; |
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rdsdebug("lc %p\n", lc); |
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spin_lock_irqsave(&loop_conns_lock, flags); |
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list_del(&lc->loop_node); |
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spin_unlock_irqrestore(&loop_conns_lock, flags); |
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kfree(lc); |
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} |
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static int rds_loop_conn_path_connect(struct rds_conn_path *cp) |
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{ |
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rds_connect_complete(cp->cp_conn); |
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return 0; |
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} |
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static void rds_loop_conn_path_shutdown(struct rds_conn_path *cp) |
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{ |
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} |
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void rds_loop_exit(void) |
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{ |
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struct rds_loop_connection *lc, *_lc; |
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LIST_HEAD(tmp_list); |
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rds_loop_set_unloading(); |
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synchronize_rcu(); |
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/* avoid calling conn_destroy with irqs off */ |
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spin_lock_irq(&loop_conns_lock); |
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list_splice(&loop_conns, &tmp_list); |
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INIT_LIST_HEAD(&loop_conns); |
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spin_unlock_irq(&loop_conns_lock); |
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list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) { |
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WARN_ON(lc->conn->c_passive); |
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rds_conn_destroy(lc->conn); |
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} |
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} |
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static void rds_loop_kill_conns(struct net *net) |
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{ |
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struct rds_loop_connection *lc, *_lc; |
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LIST_HEAD(tmp_list); |
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spin_lock_irq(&loop_conns_lock); |
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list_for_each_entry_safe(lc, _lc, &loop_conns, loop_node) { |
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struct net *c_net = read_pnet(&lc->conn->c_net); |
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if (net != c_net) |
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continue; |
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list_move_tail(&lc->loop_node, &tmp_list); |
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} |
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spin_unlock_irq(&loop_conns_lock); |
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list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) { |
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WARN_ON(lc->conn->c_passive); |
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rds_conn_destroy(lc->conn); |
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} |
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} |
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static void __net_exit rds_loop_exit_net(struct net *net) |
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{ |
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rds_loop_kill_conns(net); |
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} |
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static struct pernet_operations rds_loop_net_ops = { |
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.exit = rds_loop_exit_net, |
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}; |
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int rds_loop_net_init(void) |
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{ |
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return register_pernet_device(&rds_loop_net_ops); |
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} |
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void rds_loop_net_exit(void) |
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{ |
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unregister_pernet_device(&rds_loop_net_ops); |
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} |
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/* |
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* This is missing .xmit_* because loop doesn't go through generic |
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* rds_send_xmit() and doesn't call rds_recv_incoming(). .listen_stop and |
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* .laddr_check are missing because transport.c doesn't iterate over |
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* rds_loop_transport. |
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*/ |
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struct rds_transport rds_loop_transport = { |
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.xmit = rds_loop_xmit, |
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.recv_path = rds_loop_recv_path, |
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.conn_alloc = rds_loop_conn_alloc, |
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.conn_free = rds_loop_conn_free, |
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.conn_path_connect = rds_loop_conn_path_connect, |
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.conn_path_shutdown = rds_loop_conn_path_shutdown, |
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.inc_copy_to_user = rds_message_inc_copy_to_user, |
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.inc_free = rds_loop_inc_free, |
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.t_name = "loopback", |
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.t_type = RDS_TRANS_LOOP, |
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.t_unloading = rds_loop_is_unloading, |
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};
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