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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:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/slab.h>
35#include <net/tcp.h>
36
37#include "rds.h"
38#include "tcp.h"
39
40static struct kmem_cache *rds_tcp_incoming_slab;
41
42static void rds_tcp_inc_purge(struct rds_incoming *inc)
43{
44 struct rds_tcp_incoming *tinc;
45 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
46 rdsdebug("purging tinc %p inc %p\n", tinc, inc);
47 skb_queue_purge(&tinc->ti_skb_list);
48}
49
50void rds_tcp_inc_free(struct rds_incoming *inc)
51{
52 struct rds_tcp_incoming *tinc;
53 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
54 rds_tcp_inc_purge(inc);
55 rdsdebug("freeing tinc %p inc %p\n", tinc, inc);
56 kmem_cache_free(rds_tcp_incoming_slab, tinc);
57}
58
59/*
60 * this is pretty lame, but, whatever.
61 */
62int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
63 size_t size)
64{
65 struct rds_tcp_incoming *tinc;
66 struct iovec *iov, tmp;
67 struct sk_buff *skb;
68 unsigned long to_copy, skb_off;
69 int ret = 0;
70
71 if (size == 0)
72 goto out;
73
74 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
75 iov = first_iov;
76 tmp = *iov;
77
78 skb_queue_walk(&tinc->ti_skb_list, skb) {
79 skb_off = 0;
80 while (skb_off < skb->len) {
81 while (tmp.iov_len == 0) {
82 iov++;
83 tmp = *iov;
84 }
85
86 to_copy = min(tmp.iov_len, size);
87 to_copy = min(to_copy, skb->len - skb_off);
88
89 rdsdebug("ret %d size %zu skb %p skb_off %lu "
90 "skblen %d iov_base %p iov_len %zu cpy %lu\n",
91 ret, size, skb, skb_off, skb->len,
92 tmp.iov_base, tmp.iov_len, to_copy);
93
94 /* modifies tmp as it copies */
95 if (skb_copy_datagram_iovec(skb, skb_off, &tmp,
96 to_copy)) {
97 ret = -EFAULT;
98 goto out;
99 }
100
101 rds_stats_add(s_copy_to_user, to_copy);
102 size -= to_copy;
103 ret += to_copy;
104 skb_off += to_copy;
105 if (size == 0)
106 goto out;
107 }
108 }
109out:
110 return ret;
111}
112
113/*
114 * We have a series of skbs that have fragmented pieces of the congestion
115 * bitmap. They must add up to the exact size of the congestion bitmap. We
116 * use the skb helpers to copy those into the pages that make up the in-memory
117 * congestion bitmap for the remote address of this connection. We then tell
118 * the congestion core that the bitmap has been changed so that it can wake up
119 * sleepers.
120 *
121 * This is racing with sending paths which are using test_bit to see if the
122 * bitmap indicates that their recipient is congested.
123 */
124
125static void rds_tcp_cong_recv(struct rds_connection *conn,
126 struct rds_tcp_incoming *tinc)
127{
128 struct sk_buff *skb;
129 unsigned int to_copy, skb_off;
130 unsigned int map_off;
131 unsigned int map_page;
132 struct rds_cong_map *map;
133 int ret;
134
135 /* catch completely corrupt packets */
136 if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES)
137 return;
138
139 map_page = 0;
140 map_off = 0;
141 map = conn->c_fcong;
142
143 skb_queue_walk(&tinc->ti_skb_list, skb) {
144 skb_off = 0;
145 while (skb_off < skb->len) {
146 to_copy = min_t(unsigned int, PAGE_SIZE - map_off,
147 skb->len - skb_off);
148
149 BUG_ON(map_page >= RDS_CONG_MAP_PAGES);
150
151 /* only returns 0 or -error */
152 ret = skb_copy_bits(skb, skb_off,
153 (void *)map->m_page_addrs[map_page] + map_off,
154 to_copy);
155 BUG_ON(ret != 0);
156
157 skb_off += to_copy;
158 map_off += to_copy;
159 if (map_off == PAGE_SIZE) {
160 map_off = 0;
161 map_page++;
162 }
163 }
164 }
165
166 rds_cong_map_updated(map, ~(u64) 0);
167}
168
169struct rds_tcp_desc_arg {
170 struct rds_connection *conn;
171 gfp_t gfp;
172};
173
174static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
175 unsigned int offset, size_t len)
176{
177 struct rds_tcp_desc_arg *arg = desc->arg.data;
178 struct rds_connection *conn = arg->conn;
179 struct rds_tcp_connection *tc = conn->c_transport_data;
180 struct rds_tcp_incoming *tinc = tc->t_tinc;
181 struct sk_buff *clone;
182 size_t left = len, to_copy;
183
184 rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset,
185 len);
186
187 /*
188 * tcp_read_sock() interprets partial progress as an indication to stop
189 * processing.
190 */
191 while (left) {
192 if (!tinc) {
193 tinc = kmem_cache_alloc(rds_tcp_incoming_slab,
194 arg->gfp);
195 if (!tinc) {
196 desc->error = -ENOMEM;
197 goto out;
198 }
199 tc->t_tinc = tinc;
200 rdsdebug("alloced tinc %p\n", tinc);
201 rds_inc_init(&tinc->ti_inc, conn, conn->c_faddr);
202 /*
203 * XXX * we might be able to use the __ variants when
204 * we've already serialized at a higher level.
205 */
206 skb_queue_head_init(&tinc->ti_skb_list);
207 }
208
209 if (left && tc->t_tinc_hdr_rem) {
210 to_copy = min(tc->t_tinc_hdr_rem, left);
211 rdsdebug("copying %zu header from skb %p\n", to_copy,
212 skb);
213 skb_copy_bits(skb, offset,
214 (char *)&tinc->ti_inc.i_hdr +
215 sizeof(struct rds_header) -
216 tc->t_tinc_hdr_rem,
217 to_copy);
218 tc->t_tinc_hdr_rem -= to_copy;
219 left -= to_copy;
220 offset += to_copy;
221
222 if (tc->t_tinc_hdr_rem == 0) {
223 /* could be 0 for a 0 len message */
224 tc->t_tinc_data_rem =
225 be32_to_cpu(tinc->ti_inc.i_hdr.h_len);
226 }
227 }
228
229 if (left && tc->t_tinc_data_rem) {
230 clone = skb_clone(skb, arg->gfp);
231 if (!clone) {
232 desc->error = -ENOMEM;
233 goto out;
234 }
235
236 to_copy = min(tc->t_tinc_data_rem, left);
237 pskb_pull(clone, offset);
238 pskb_trim(clone, to_copy);
239 skb_queue_tail(&tinc->ti_skb_list, clone);
240
241 rdsdebug("skb %p data %p len %d off %u to_copy %zu -> "
242 "clone %p data %p len %d\n",
243 skb, skb->data, skb->len, offset, to_copy,
244 clone, clone->data, clone->len);
245
246 tc->t_tinc_data_rem -= to_copy;
247 left -= to_copy;
248 offset += to_copy;
249 }
250
251 if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) {
252 if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
253 rds_tcp_cong_recv(conn, tinc);
254 else
255 rds_recv_incoming(conn, conn->c_faddr,
256 conn->c_laddr, &tinc->ti_inc,
257 arg->gfp);
258
259 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
260 tc->t_tinc_data_rem = 0;
261 tc->t_tinc = NULL;
262 rds_inc_put(&tinc->ti_inc);
263 tinc = NULL;
264 }
265 }
266out:
267 rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n",
268 len, left, skb->len,
269 skb_queue_len(&tc->t_sock->sk->sk_receive_queue));
270 return len - left;
271}
272
273/* the caller has to hold the sock lock */
274static int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp)
275{
276 struct rds_tcp_connection *tc = conn->c_transport_data;
277 struct socket *sock = tc->t_sock;
278 read_descriptor_t desc;
279 struct rds_tcp_desc_arg arg;
280
281 /* It's like glib in the kernel! */
282 arg.conn = conn;
283 arg.gfp = gfp;
284 desc.arg.data = &arg;
285 desc.error = 0;
286 desc.count = 1; /* give more than one skb per call */
287
288 tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv);
289 rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp,
290 desc.error);
291
292 return desc.error;
293}
294
295/*
296 * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from
297 * data_ready.
298 *
299 * if we fail to allocate we're in trouble.. blindly wait some time before
300 * trying again to see if the VM can free up something for us.
301 */
302int rds_tcp_recv(struct rds_connection *conn)
303{
304 struct rds_tcp_connection *tc = conn->c_transport_data;
305 struct socket *sock = tc->t_sock;
306 int ret = 0;
307
308 rdsdebug("recv worker conn %p tc %p sock %p\n", conn, tc, sock);
309
310 lock_sock(sock->sk);
311 ret = rds_tcp_read_sock(conn, GFP_KERNEL);
312 release_sock(sock->sk);
313
314 return ret;
315}
316
317void rds_tcp_data_ready(struct sock *sk, int bytes)
318{
319 void (*ready)(struct sock *sk, int bytes);
320 struct rds_connection *conn;
321 struct rds_tcp_connection *tc;
322
323 rdsdebug("data ready sk %p bytes %d\n", sk, bytes);
324
325 read_lock_bh(&sk->sk_callback_lock);
326 conn = sk->sk_user_data;
327 if (!conn) { /* check for teardown race */
328 ready = sk->sk_data_ready;
329 goto out;
330 }
331
332 tc = conn->c_transport_data;
333 ready = tc->t_orig_data_ready;
334 rds_tcp_stats_inc(s_tcp_data_ready_calls);
335
336 if (rds_tcp_read_sock(conn, GFP_ATOMIC) == -ENOMEM)
337 queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
338out:
339 read_unlock_bh(&sk->sk_callback_lock);
340 ready(sk, bytes);
341}
342
343int rds_tcp_recv_init(void)
344{
345 rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming",
346 sizeof(struct rds_tcp_incoming),
347 0, 0, NULL);
348 if (!rds_tcp_incoming_slab)
349 return -ENOMEM;
350 return 0;
351}
352
353void rds_tcp_recv_exit(void)
354{
355 kmem_cache_destroy(rds_tcp_incoming_slab);
356}
1/*
2 * Copyright (c) 2006, 2017 Oracle and/or its affiliates. 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:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/slab.h>
35#include <net/tcp.h>
36#include <trace/events/sock.h>
37
38#include "rds.h"
39#include "tcp.h"
40
41static struct kmem_cache *rds_tcp_incoming_slab;
42
43static void rds_tcp_inc_purge(struct rds_incoming *inc)
44{
45 struct rds_tcp_incoming *tinc;
46 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
47 rdsdebug("purging tinc %p inc %p\n", tinc, inc);
48 skb_queue_purge(&tinc->ti_skb_list);
49}
50
51void rds_tcp_inc_free(struct rds_incoming *inc)
52{
53 struct rds_tcp_incoming *tinc;
54 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
55 rds_tcp_inc_purge(inc);
56 rdsdebug("freeing tinc %p inc %p\n", tinc, inc);
57 kmem_cache_free(rds_tcp_incoming_slab, tinc);
58}
59
60/*
61 * this is pretty lame, but, whatever.
62 */
63int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
64{
65 struct rds_tcp_incoming *tinc;
66 struct sk_buff *skb;
67 int ret = 0;
68
69 if (!iov_iter_count(to))
70 goto out;
71
72 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
73
74 skb_queue_walk(&tinc->ti_skb_list, skb) {
75 unsigned long to_copy, skb_off;
76 for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) {
77 to_copy = iov_iter_count(to);
78 to_copy = min(to_copy, skb->len - skb_off);
79
80 if (skb_copy_datagram_iter(skb, skb_off, to, to_copy))
81 return -EFAULT;
82
83 rds_stats_add(s_copy_to_user, to_copy);
84 ret += to_copy;
85
86 if (!iov_iter_count(to))
87 goto out;
88 }
89 }
90out:
91 return ret;
92}
93
94/*
95 * We have a series of skbs that have fragmented pieces of the congestion
96 * bitmap. They must add up to the exact size of the congestion bitmap. We
97 * use the skb helpers to copy those into the pages that make up the in-memory
98 * congestion bitmap for the remote address of this connection. We then tell
99 * the congestion core that the bitmap has been changed so that it can wake up
100 * sleepers.
101 *
102 * This is racing with sending paths which are using test_bit to see if the
103 * bitmap indicates that their recipient is congested.
104 */
105
106static void rds_tcp_cong_recv(struct rds_connection *conn,
107 struct rds_tcp_incoming *tinc)
108{
109 struct sk_buff *skb;
110 unsigned int to_copy, skb_off;
111 unsigned int map_off;
112 unsigned int map_page;
113 struct rds_cong_map *map;
114 int ret;
115
116 /* catch completely corrupt packets */
117 if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES)
118 return;
119
120 map_page = 0;
121 map_off = 0;
122 map = conn->c_fcong;
123
124 skb_queue_walk(&tinc->ti_skb_list, skb) {
125 skb_off = 0;
126 while (skb_off < skb->len) {
127 to_copy = min_t(unsigned int, PAGE_SIZE - map_off,
128 skb->len - skb_off);
129
130 BUG_ON(map_page >= RDS_CONG_MAP_PAGES);
131
132 /* only returns 0 or -error */
133 ret = skb_copy_bits(skb, skb_off,
134 (void *)map->m_page_addrs[map_page] + map_off,
135 to_copy);
136 BUG_ON(ret != 0);
137
138 skb_off += to_copy;
139 map_off += to_copy;
140 if (map_off == PAGE_SIZE) {
141 map_off = 0;
142 map_page++;
143 }
144 }
145 }
146
147 rds_cong_map_updated(map, ~(u64) 0);
148}
149
150struct rds_tcp_desc_arg {
151 struct rds_conn_path *conn_path;
152 gfp_t gfp;
153};
154
155static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
156 unsigned int offset, size_t len)
157{
158 struct rds_tcp_desc_arg *arg = desc->arg.data;
159 struct rds_conn_path *cp = arg->conn_path;
160 struct rds_tcp_connection *tc = cp->cp_transport_data;
161 struct rds_tcp_incoming *tinc = tc->t_tinc;
162 struct sk_buff *clone;
163 size_t left = len, to_copy;
164
165 rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset,
166 len);
167
168 /*
169 * tcp_read_sock() interprets partial progress as an indication to stop
170 * processing.
171 */
172 while (left) {
173 if (!tinc) {
174 tinc = kmem_cache_alloc(rds_tcp_incoming_slab,
175 arg->gfp);
176 if (!tinc) {
177 desc->error = -ENOMEM;
178 goto out;
179 }
180 tc->t_tinc = tinc;
181 rdsdebug("allocated tinc %p\n", tinc);
182 rds_inc_path_init(&tinc->ti_inc, cp,
183 &cp->cp_conn->c_faddr);
184 tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_HDR] =
185 local_clock();
186
187 /*
188 * XXX * we might be able to use the __ variants when
189 * we've already serialized at a higher level.
190 */
191 skb_queue_head_init(&tinc->ti_skb_list);
192 }
193
194 if (left && tc->t_tinc_hdr_rem) {
195 to_copy = min(tc->t_tinc_hdr_rem, left);
196 rdsdebug("copying %zu header from skb %p\n", to_copy,
197 skb);
198 skb_copy_bits(skb, offset,
199 (char *)&tinc->ti_inc.i_hdr +
200 sizeof(struct rds_header) -
201 tc->t_tinc_hdr_rem,
202 to_copy);
203 tc->t_tinc_hdr_rem -= to_copy;
204 left -= to_copy;
205 offset += to_copy;
206
207 if (tc->t_tinc_hdr_rem == 0) {
208 /* could be 0 for a 0 len message */
209 tc->t_tinc_data_rem =
210 be32_to_cpu(tinc->ti_inc.i_hdr.h_len);
211 tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_START] =
212 local_clock();
213 }
214 }
215
216 if (left && tc->t_tinc_data_rem) {
217 to_copy = min(tc->t_tinc_data_rem, left);
218
219 clone = pskb_extract(skb, offset, to_copy, arg->gfp);
220 if (!clone) {
221 desc->error = -ENOMEM;
222 goto out;
223 }
224
225 skb_queue_tail(&tinc->ti_skb_list, clone);
226
227 rdsdebug("skb %p data %p len %d off %u to_copy %zu -> "
228 "clone %p data %p len %d\n",
229 skb, skb->data, skb->len, offset, to_copy,
230 clone, clone->data, clone->len);
231
232 tc->t_tinc_data_rem -= to_copy;
233 left -= to_copy;
234 offset += to_copy;
235 }
236
237 if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) {
238 struct rds_connection *conn = cp->cp_conn;
239
240 if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
241 rds_tcp_cong_recv(conn, tinc);
242 else
243 rds_recv_incoming(conn, &conn->c_faddr,
244 &conn->c_laddr,
245 &tinc->ti_inc,
246 arg->gfp);
247
248 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
249 tc->t_tinc_data_rem = 0;
250 tc->t_tinc = NULL;
251 rds_inc_put(&tinc->ti_inc);
252 tinc = NULL;
253 }
254 }
255out:
256 rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n",
257 len, left, skb->len,
258 skb_queue_len(&tc->t_sock->sk->sk_receive_queue));
259 return len - left;
260}
261
262/* the caller has to hold the sock lock */
263static int rds_tcp_read_sock(struct rds_conn_path *cp, gfp_t gfp)
264{
265 struct rds_tcp_connection *tc = cp->cp_transport_data;
266 struct socket *sock = tc->t_sock;
267 read_descriptor_t desc;
268 struct rds_tcp_desc_arg arg;
269
270 /* It's like glib in the kernel! */
271 arg.conn_path = cp;
272 arg.gfp = gfp;
273 desc.arg.data = &arg;
274 desc.error = 0;
275 desc.count = 1; /* give more than one skb per call */
276
277 tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv);
278 rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp,
279 desc.error);
280
281 return desc.error;
282}
283
284/*
285 * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from
286 * data_ready.
287 *
288 * if we fail to allocate we're in trouble.. blindly wait some time before
289 * trying again to see if the VM can free up something for us.
290 */
291int rds_tcp_recv_path(struct rds_conn_path *cp)
292{
293 struct rds_tcp_connection *tc = cp->cp_transport_data;
294 struct socket *sock = tc->t_sock;
295 int ret = 0;
296
297 rdsdebug("recv worker path [%d] tc %p sock %p\n",
298 cp->cp_index, tc, sock);
299
300 lock_sock(sock->sk);
301 ret = rds_tcp_read_sock(cp, GFP_KERNEL);
302 release_sock(sock->sk);
303
304 return ret;
305}
306
307void rds_tcp_data_ready(struct sock *sk)
308{
309 void (*ready)(struct sock *sk);
310 struct rds_conn_path *cp;
311 struct rds_tcp_connection *tc;
312
313 trace_sk_data_ready(sk);
314 rdsdebug("data ready sk %p\n", sk);
315
316 read_lock_bh(&sk->sk_callback_lock);
317 cp = sk->sk_user_data;
318 if (!cp) { /* check for teardown race */
319 ready = sk->sk_data_ready;
320 goto out;
321 }
322
323 tc = cp->cp_transport_data;
324 ready = tc->t_orig_data_ready;
325 rds_tcp_stats_inc(s_tcp_data_ready_calls);
326
327 if (rds_tcp_read_sock(cp, GFP_ATOMIC) == -ENOMEM) {
328 rcu_read_lock();
329 if (!rds_destroy_pending(cp->cp_conn))
330 queue_delayed_work(rds_wq, &cp->cp_recv_w, 0);
331 rcu_read_unlock();
332 }
333out:
334 read_unlock_bh(&sk->sk_callback_lock);
335 ready(sk);
336}
337
338int rds_tcp_recv_init(void)
339{
340 rds_tcp_incoming_slab = KMEM_CACHE(rds_tcp_incoming, 0);
341 if (!rds_tcp_incoming_slab)
342 return -ENOMEM;
343 return 0;
344}
345
346void rds_tcp_recv_exit(void)
347{
348 kmem_cache_destroy(rds_tcp_incoming_slab);
349}