tcp.c (afb4164d91c7486a1d4ab098a1b88e27b5e25772) tcp.c (ea3b1ea53930879c9847044f5cb9c97411cae797)
1/*
2 * Copyright (c) 2006 Oracle. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:

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131 * returns the existing tc->t_sock.
132 *
133 * The only functions that set tc->t_sock are rds_tcp_set_callbacks
134 * and rds_tcp_reset_callbacks. Send and receive trust that
135 * it is set. The absence of RDS_CONN_UP bit protects those paths
136 * from being called while it isn't set.
137 */
138void rds_tcp_reset_callbacks(struct socket *sock,
1/*
2 * Copyright (c) 2006 Oracle. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:

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131 * returns the existing tc->t_sock.
132 *
133 * The only functions that set tc->t_sock are rds_tcp_set_callbacks
134 * and rds_tcp_reset_callbacks. Send and receive trust that
135 * it is set. The absence of RDS_CONN_UP bit protects those paths
136 * from being called while it isn't set.
137 */
138void rds_tcp_reset_callbacks(struct socket *sock,
139 struct rds_connection *conn)
139 struct rds_conn_path *cp)
140{
140{
141 struct rds_tcp_connection *tc = conn->c_transport_data;
141 struct rds_tcp_connection *tc = cp->cp_transport_data;
142 struct socket *osock = tc->t_sock;
143
144 if (!osock)
145 goto newsock;
146
147 /* Need to resolve a duelling SYN between peers.
148 * We have an outstanding SYN to this peer, which may
149 * potentially have transitioned to the RDS_CONN_UP state,
150 * so we must quiesce any send threads before resetting
142 struct socket *osock = tc->t_sock;
143
144 if (!osock)
145 goto newsock;
146
147 /* Need to resolve a duelling SYN between peers.
148 * We have an outstanding SYN to this peer, which may
149 * potentially have transitioned to the RDS_CONN_UP state,
150 * so we must quiesce any send threads before resetting
151 * c_transport_data. We quiesce these threads by setting
152 * c_state to something other than RDS_CONN_UP, and then
151 * cp_transport_data. We quiesce these threads by setting
152 * cp_state to something other than RDS_CONN_UP, and then
153 * waiting for any existing threads in rds_send_xmit to
154 * complete release_in_xmit(). (Subsequent threads entering
155 * rds_send_xmit() will bail on !rds_conn_up().
156 *
157 * However an incoming syn-ack at this point would end up
158 * marking the conn as RDS_CONN_UP, and would again permit
159 * rds_send_xmi() threads through, so ideally we would
160 * synchronize on RDS_CONN_UP after lock_sock(), but cannot
161 * do that: waiting on !RDS_IN_XMIT after lock_sock() may
162 * end up deadlocking with tcp_sendmsg(), and the RDS_IN_XMIT
163 * would not get set. As a result, we set c_state to
164 * RDS_CONN_RESETTTING, to ensure that rds_tcp_state_change
165 * cannot mark rds_conn_path_up() in the window before lock_sock()
166 */
153 * waiting for any existing threads in rds_send_xmit to
154 * complete release_in_xmit(). (Subsequent threads entering
155 * rds_send_xmit() will bail on !rds_conn_up().
156 *
157 * However an incoming syn-ack at this point would end up
158 * marking the conn as RDS_CONN_UP, and would again permit
159 * rds_send_xmi() threads through, so ideally we would
160 * synchronize on RDS_CONN_UP after lock_sock(), but cannot
161 * do that: waiting on !RDS_IN_XMIT after lock_sock() may
162 * end up deadlocking with tcp_sendmsg(), and the RDS_IN_XMIT
163 * would not get set. As a result, we set c_state to
164 * RDS_CONN_RESETTTING, to ensure that rds_tcp_state_change
165 * cannot mark rds_conn_path_up() in the window before lock_sock()
166 */
167 atomic_set(&conn->c_state, RDS_CONN_RESETTING);
168 wait_event(conn->c_waitq, !test_bit(RDS_IN_XMIT, &conn->c_flags));
167 atomic_set(&cp->cp_state, RDS_CONN_RESETTING);
168 wait_event(cp->cp_waitq, !test_bit(RDS_IN_XMIT, &cp->cp_flags));
169 lock_sock(osock->sk);
170 /* reset receive side state for rds_tcp_data_recv() for osock */
171 if (tc->t_tinc) {
172 rds_inc_put(&tc->t_tinc->ti_inc);
173 tc->t_tinc = NULL;
174 }
175 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
176 tc->t_tinc_data_rem = 0;

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181 osock->sk->sk_user_data = NULL;
182 osock->sk->sk_data_ready = tc->t_orig_data_ready;
183 osock->sk->sk_write_space = tc->t_orig_write_space;
184 osock->sk->sk_state_change = tc->t_orig_state_change;
185 write_unlock_bh(&osock->sk->sk_callback_lock);
186 release_sock(osock->sk);
187 sock_release(osock);
188newsock:
169 lock_sock(osock->sk);
170 /* reset receive side state for rds_tcp_data_recv() for osock */
171 if (tc->t_tinc) {
172 rds_inc_put(&tc->t_tinc->ti_inc);
173 tc->t_tinc = NULL;
174 }
175 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
176 tc->t_tinc_data_rem = 0;

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181 osock->sk->sk_user_data = NULL;
182 osock->sk->sk_data_ready = tc->t_orig_data_ready;
183 osock->sk->sk_write_space = tc->t_orig_write_space;
184 osock->sk->sk_state_change = tc->t_orig_state_change;
185 write_unlock_bh(&osock->sk->sk_callback_lock);
186 release_sock(osock->sk);
187 sock_release(osock);
188newsock:
189 rds_send_path_reset(&conn->c_path[0]);
189 rds_send_path_reset(cp);
190 lock_sock(sock->sk);
191 write_lock_bh(&sock->sk->sk_callback_lock);
192 tc->t_sock = sock;
190 lock_sock(sock->sk);
191 write_lock_bh(&sock->sk->sk_callback_lock);
192 tc->t_sock = sock;
193 sock->sk->sk_user_data = conn;
193 tc->t_cpath = cp;
194 sock->sk->sk_user_data = cp;
194 sock->sk->sk_data_ready = rds_tcp_data_ready;
195 sock->sk->sk_write_space = rds_tcp_write_space;
196 sock->sk->sk_state_change = rds_tcp_state_change;
197
198 write_unlock_bh(&sock->sk->sk_callback_lock);
199 release_sock(sock->sk);
200}
201
202/* Add tc to rds_tcp_tc_list and set tc->t_sock. See comments
203 * above rds_tcp_reset_callbacks for notes about synchronization
204 * with data path
205 */
195 sock->sk->sk_data_ready = rds_tcp_data_ready;
196 sock->sk->sk_write_space = rds_tcp_write_space;
197 sock->sk->sk_state_change = rds_tcp_state_change;
198
199 write_unlock_bh(&sock->sk->sk_callback_lock);
200 release_sock(sock->sk);
201}
202
203/* Add tc to rds_tcp_tc_list and set tc->t_sock. See comments
204 * above rds_tcp_reset_callbacks for notes about synchronization
205 * with data path
206 */
206void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
207void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp)
207{
208{
208 struct rds_tcp_connection *tc = conn->c_transport_data;
209 struct rds_tcp_connection *tc = cp->cp_transport_data;
209
210 rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
211 write_lock_bh(&sock->sk->sk_callback_lock);
212
213 /* done under the callback_lock to serialize with write_space */
214 spin_lock(&rds_tcp_tc_list_lock);
215 list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
216 rds_tcp_tc_count++;
217 spin_unlock(&rds_tcp_tc_list_lock);
218
219 /* accepted sockets need our listen data ready undone */
220 if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
221 sock->sk->sk_data_ready = sock->sk->sk_user_data;
222
223 tc->t_sock = sock;
210
211 rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
212 write_lock_bh(&sock->sk->sk_callback_lock);
213
214 /* done under the callback_lock to serialize with write_space */
215 spin_lock(&rds_tcp_tc_list_lock);
216 list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
217 rds_tcp_tc_count++;
218 spin_unlock(&rds_tcp_tc_list_lock);
219
220 /* accepted sockets need our listen data ready undone */
221 if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
222 sock->sk->sk_data_ready = sock->sk->sk_user_data;
223
224 tc->t_sock = sock;
224 tc->t_cpath = &conn->c_path[0];
225 tc->t_cpath = cp;
225 tc->t_orig_data_ready = sock->sk->sk_data_ready;
226 tc->t_orig_write_space = sock->sk->sk_write_space;
227 tc->t_orig_state_change = sock->sk->sk_state_change;
228
226 tc->t_orig_data_ready = sock->sk->sk_data_ready;
227 tc->t_orig_write_space = sock->sk->sk_write_space;
228 tc->t_orig_state_change = sock->sk->sk_state_change;
229
229 sock->sk->sk_user_data = conn;
230 sock->sk->sk_user_data = cp;
230 sock->sk->sk_data_ready = rds_tcp_data_ready;
231 sock->sk->sk_write_space = rds_tcp_write_space;
232 sock->sk->sk_state_change = rds_tcp_state_change;
233
234 write_unlock_bh(&sock->sk->sk_callback_lock);
235}
236
237static void rds_tcp_tc_info(struct socket *sock, unsigned int len,

--- 439 unchanged lines hidden --- 		231 sock->sk->sk_data_ready = rds_tcp_data_ready;
232 sock->sk->sk_write_space = rds_tcp_write_space;
233 sock->sk->sk_state_change = rds_tcp_state_change;
234
235 write_unlock_bh(&sock->sk->sk_callback_lock);
236}
237
238static void rds_tcp_tc_info(struct socket *sock, unsigned int len,

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