blob: fbc5ef88bc0e692ea4cf9cb59f6163905510928e [file] [log] [blame]
Andy Grover70041082009-08-21 12:28:31 +00001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090034#include <linux/slab.h>
Andy Grover70041082009-08-21 12:28:31 +000035#include <net/tcp.h>
36
37#include "rds.h"
38#include "tcp.h"
39
40static struct kmem_cache *rds_tcp_incoming_slab;
41
Andy Grover809fa142010-01-12 14:41:46 -080042static void rds_tcp_inc_purge(struct rds_incoming *inc)
Andy Grover70041082009-08-21 12:28:31 +000043{
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 */
Al Viroc310e722014-11-20 09:21:14 -050062int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
Andy Grover70041082009-08-21 12:28:31 +000063{
64 struct rds_tcp_incoming *tinc;
Andy Grover70041082009-08-21 12:28:31 +000065 struct sk_buff *skb;
Andy Grover70041082009-08-21 12:28:31 +000066 int ret = 0;
67
Al Viroc310e722014-11-20 09:21:14 -050068 if (!iov_iter_count(to))
Andy Grover70041082009-08-21 12:28:31 +000069 goto out;
70
71 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
Andy Grover70041082009-08-21 12:28:31 +000072
73 skb_queue_walk(&tinc->ti_skb_list, skb) {
Al Viroc310e722014-11-20 09:21:14 -050074 unsigned long to_copy, skb_off;
75 for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) {
76 to_copy = iov_iter_count(to);
Andy Grover70041082009-08-21 12:28:31 +000077 to_copy = min(to_copy, skb->len - skb_off);
78
Al Viroc310e722014-11-20 09:21:14 -050079 if (skb_copy_datagram_iter(skb, skb_off, to, to_copy))
80 return -EFAULT;
Andy Grover70041082009-08-21 12:28:31 +000081
Andy Groverb075cfd2010-03-11 13:49:57 +000082 rds_stats_add(s_copy_to_user, to_copy);
Andy Grover70041082009-08-21 12:28:31 +000083 ret += to_copy;
Al Viroc310e722014-11-20 09:21:14 -050084
85 if (!iov_iter_count(to))
Andy Grover70041082009-08-21 12:28:31 +000086 goto out;
87 }
88 }
89out:
90 return ret;
91}
92
93/*
94 * We have a series of skbs that have fragmented pieces of the congestion
95 * bitmap. They must add up to the exact size of the congestion bitmap. We
96 * use the skb helpers to copy those into the pages that make up the in-memory
97 * congestion bitmap for the remote address of this connection. We then tell
98 * the congestion core that the bitmap has been changed so that it can wake up
99 * sleepers.
100 *
101 * This is racing with sending paths which are using test_bit to see if the
102 * bitmap indicates that their recipient is congested.
103 */
104
105static void rds_tcp_cong_recv(struct rds_connection *conn,
106 struct rds_tcp_incoming *tinc)
107{
108 struct sk_buff *skb;
109 unsigned int to_copy, skb_off;
110 unsigned int map_off;
111 unsigned int map_page;
112 struct rds_cong_map *map;
113 int ret;
114
115 /* catch completely corrupt packets */
116 if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES)
117 return;
118
119 map_page = 0;
120 map_off = 0;
121 map = conn->c_fcong;
122
123 skb_queue_walk(&tinc->ti_skb_list, skb) {
124 skb_off = 0;
125 while (skb_off < skb->len) {
126 to_copy = min_t(unsigned int, PAGE_SIZE - map_off,
127 skb->len - skb_off);
128
129 BUG_ON(map_page >= RDS_CONG_MAP_PAGES);
130
131 /* only returns 0 or -error */
132 ret = skb_copy_bits(skb, skb_off,
133 (void *)map->m_page_addrs[map_page] + map_off,
134 to_copy);
135 BUG_ON(ret != 0);
136
137 skb_off += to_copy;
138 map_off += to_copy;
139 if (map_off == PAGE_SIZE) {
140 map_off = 0;
141 map_page++;
142 }
143 }
144 }
145
146 rds_cong_map_updated(map, ~(u64) 0);
147}
148
149struct rds_tcp_desc_arg {
150 struct rds_connection *conn;
151 gfp_t gfp;
Andy Grover70041082009-08-21 12:28:31 +0000152};
153
154static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
155 unsigned int offset, size_t len)
156{
157 struct rds_tcp_desc_arg *arg = desc->arg.data;
158 struct rds_connection *conn = arg->conn;
159 struct rds_tcp_connection *tc = conn->c_transport_data;
160 struct rds_tcp_incoming *tinc = tc->t_tinc;
161 struct sk_buff *clone;
162 size_t left = len, to_copy;
163
164 rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset,
165 len);
166
167 /*
168 * tcp_read_sock() interprets partial progress as an indication to stop
169 * processing.
170 */
171 while (left) {
Andy Grover8690bfa2010-01-12 11:56:44 -0800172 if (!tinc) {
Andy Grover70041082009-08-21 12:28:31 +0000173 tinc = kmem_cache_alloc(rds_tcp_incoming_slab,
174 arg->gfp);
Andy Grover8690bfa2010-01-12 11:56:44 -0800175 if (!tinc) {
Andy Grover70041082009-08-21 12:28:31 +0000176 desc->error = -ENOMEM;
177 goto out;
178 }
179 tc->t_tinc = tinc;
180 rdsdebug("alloced tinc %p\n", tinc);
181 rds_inc_init(&tinc->ti_inc, conn, conn->c_faddr);
182 /*
183 * XXX * we might be able to use the __ variants when
184 * we've already serialized at a higher level.
185 */
186 skb_queue_head_init(&tinc->ti_skb_list);
187 }
188
189 if (left && tc->t_tinc_hdr_rem) {
190 to_copy = min(tc->t_tinc_hdr_rem, left);
191 rdsdebug("copying %zu header from skb %p\n", to_copy,
192 skb);
193 skb_copy_bits(skb, offset,
194 (char *)&tinc->ti_inc.i_hdr +
195 sizeof(struct rds_header) -
196 tc->t_tinc_hdr_rem,
197 to_copy);
198 tc->t_tinc_hdr_rem -= to_copy;
199 left -= to_copy;
200 offset += to_copy;
201
202 if (tc->t_tinc_hdr_rem == 0) {
203 /* could be 0 for a 0 len message */
204 tc->t_tinc_data_rem =
205 be32_to_cpu(tinc->ti_inc.i_hdr.h_len);
206 }
207 }
208
209 if (left && tc->t_tinc_data_rem) {
210 clone = skb_clone(skb, arg->gfp);
Andy Grover8690bfa2010-01-12 11:56:44 -0800211 if (!clone) {
Andy Grover70041082009-08-21 12:28:31 +0000212 desc->error = -ENOMEM;
213 goto out;
214 }
215
216 to_copy = min(tc->t_tinc_data_rem, left);
217 pskb_pull(clone, offset);
218 pskb_trim(clone, to_copy);
219 skb_queue_tail(&tinc->ti_skb_list, clone);
220
221 rdsdebug("skb %p data %p len %d off %u to_copy %zu -> "
222 "clone %p data %p len %d\n",
223 skb, skb->data, skb->len, offset, to_copy,
224 clone, clone->data, clone->len);
225
226 tc->t_tinc_data_rem -= to_copy;
227 left -= to_copy;
228 offset += to_copy;
229 }
230
231 if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) {
232 if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
233 rds_tcp_cong_recv(conn, tinc);
234 else
235 rds_recv_incoming(conn, conn->c_faddr,
236 conn->c_laddr, &tinc->ti_inc,
Cong Wang6114eab2011-11-25 23:14:40 +0800237 arg->gfp);
Andy Grover70041082009-08-21 12:28:31 +0000238
239 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
240 tc->t_tinc_data_rem = 0;
241 tc->t_tinc = NULL;
242 rds_inc_put(&tinc->ti_inc);
243 tinc = NULL;
244 }
245 }
246out:
247 rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n",
248 len, left, skb->len,
249 skb_queue_len(&tc->t_sock->sk->sk_receive_queue));
250 return len - left;
251}
252
253/* the caller has to hold the sock lock */
Cong Wang6114eab2011-11-25 23:14:40 +0800254static int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp)
Andy Grover70041082009-08-21 12:28:31 +0000255{
256 struct rds_tcp_connection *tc = conn->c_transport_data;
257 struct socket *sock = tc->t_sock;
258 read_descriptor_t desc;
259 struct rds_tcp_desc_arg arg;
260
261 /* It's like glib in the kernel! */
262 arg.conn = conn;
263 arg.gfp = gfp;
Andy Grover70041082009-08-21 12:28:31 +0000264 desc.arg.data = &arg;
265 desc.error = 0;
266 desc.count = 1; /* give more than one skb per call */
267
268 tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv);
269 rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp,
270 desc.error);
271
272 return desc.error;
273}
274
275/*
276 * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from
277 * data_ready.
278 *
279 * if we fail to allocate we're in trouble.. blindly wait some time before
280 * trying again to see if the VM can free up something for us.
281 */
282int rds_tcp_recv(struct rds_connection *conn)
283{
284 struct rds_tcp_connection *tc = conn->c_transport_data;
285 struct socket *sock = tc->t_sock;
286 int ret = 0;
287
288 rdsdebug("recv worker conn %p tc %p sock %p\n", conn, tc, sock);
289
290 lock_sock(sock->sk);
Cong Wang6114eab2011-11-25 23:14:40 +0800291 ret = rds_tcp_read_sock(conn, GFP_KERNEL);
Andy Grover70041082009-08-21 12:28:31 +0000292 release_sock(sock->sk);
293
294 return ret;
295}
296
David S. Miller676d2362014-04-11 16:15:36 -0400297void rds_tcp_data_ready(struct sock *sk)
Andy Grover70041082009-08-21 12:28:31 +0000298{
David S. Miller676d2362014-04-11 16:15:36 -0400299 void (*ready)(struct sock *sk);
Andy Grover70041082009-08-21 12:28:31 +0000300 struct rds_connection *conn;
301 struct rds_tcp_connection *tc;
302
David S. Miller676d2362014-04-11 16:15:36 -0400303 rdsdebug("data ready sk %p\n", sk);
Andy Grover70041082009-08-21 12:28:31 +0000304
Ying Xuebfdc5872012-08-19 21:44:08 +0000305 read_lock(&sk->sk_callback_lock);
Andy Grover70041082009-08-21 12:28:31 +0000306 conn = sk->sk_user_data;
Andy Grover8690bfa2010-01-12 11:56:44 -0800307 if (!conn) { /* check for teardown race */
Andy Grover70041082009-08-21 12:28:31 +0000308 ready = sk->sk_data_ready;
309 goto out;
310 }
311
312 tc = conn->c_transport_data;
313 ready = tc->t_orig_data_ready;
314 rds_tcp_stats_inc(s_tcp_data_ready_calls);
315
Cong Wang6114eab2011-11-25 23:14:40 +0800316 if (rds_tcp_read_sock(conn, GFP_ATOMIC) == -ENOMEM)
Andy Grover70041082009-08-21 12:28:31 +0000317 queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
318out:
Ying Xuebfdc5872012-08-19 21:44:08 +0000319 read_unlock(&sk->sk_callback_lock);
David S. Miller676d2362014-04-11 16:15:36 -0400320 ready(sk);
Andy Grover70041082009-08-21 12:28:31 +0000321}
322
Zach Brownef87b7e2010-07-09 12:26:20 -0700323int rds_tcp_recv_init(void)
Andy Grover70041082009-08-21 12:28:31 +0000324{
325 rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming",
326 sizeof(struct rds_tcp_incoming),
327 0, 0, NULL);
Andy Grover8690bfa2010-01-12 11:56:44 -0800328 if (!rds_tcp_incoming_slab)
Andy Grover70041082009-08-21 12:28:31 +0000329 return -ENOMEM;
330 return 0;
331}
332
333void rds_tcp_recv_exit(void)
334{
335 kmem_cache_destroy(rds_tcp_incoming_slab);
336}