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70041088 AG |
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> | |
5a0e3ad6 | 34 | #include <linux/slab.h> |
70041088 AG |
35 | #include <net/tcp.h> |
36 | ||
37 | #include "rds.h" | |
38 | #include "tcp.h" | |
39 | ||
40 | static struct kmem_cache *rds_tcp_incoming_slab; | |
41 | ||
809fa148 | 42 | static void rds_tcp_inc_purge(struct rds_incoming *inc) |
70041088 AG |
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 | ||
50 | void 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 | */ | |
62 | int 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 | ||
b075cfdb | 101 | rds_stats_add(s_copy_to_user, to_copy); |
70041088 AG |
102 | size -= to_copy; |
103 | ret += to_copy; | |
104 | skb_off += to_copy; | |
105 | if (size == 0) | |
106 | goto out; | |
107 | } | |
108 | } | |
109 | out: | |
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 | ||
125 | static 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 | ||
169 | struct rds_tcp_desc_arg { | |
170 | struct rds_connection *conn; | |
171 | gfp_t gfp; | |
70041088 AG |
172 | }; |
173 | ||
174 | static 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) { | |
8690bfa1 | 192 | if (!tinc) { |
70041088 AG |
193 | tinc = kmem_cache_alloc(rds_tcp_incoming_slab, |
194 | arg->gfp); | |
8690bfa1 | 195 | if (!tinc) { |
70041088 AG |
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); | |
8690bfa1 | 231 | if (!clone) { |
70041088 AG |
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, | |
6114eab5 | 257 | arg->gfp); |
70041088 AG |
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 | } | |
266 | out: | |
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 */ | |
6114eab5 | 274 | static int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp) |
70041088 AG |
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; | |
70041088 AG |
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 | */ | |
302 | int 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); | |
6114eab5 | 311 | ret = rds_tcp_read_sock(conn, GFP_KERNEL); |
70041088 AG |
312 | release_sock(sock->sk); |
313 | ||
314 | return ret; | |
315 | } | |
316 | ||
317 | void 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 | ||
bfdc587c | 325 | read_lock(&sk->sk_callback_lock); |
70041088 | 326 | conn = sk->sk_user_data; |
8690bfa1 | 327 | if (!conn) { /* check for teardown race */ |
70041088 AG |
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 | ||
6114eab5 | 336 | if (rds_tcp_read_sock(conn, GFP_ATOMIC) == -ENOMEM) |
70041088 AG |
337 | queue_delayed_work(rds_wq, &conn->c_recv_w, 0); |
338 | out: | |
bfdc587c | 339 | read_unlock(&sk->sk_callback_lock); |
70041088 AG |
340 | ready(sk, bytes); |
341 | } | |
342 | ||
ef87b7ea | 343 | int rds_tcp_recv_init(void) |
70041088 AG |
344 | { |
345 | rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming", | |
346 | sizeof(struct rds_tcp_incoming), | |
347 | 0, 0, NULL); | |
8690bfa1 | 348 | if (!rds_tcp_incoming_slab) |
70041088 AG |
349 | return -ENOMEM; |
350 | return 0; | |
351 | } | |
352 | ||
353 | void rds_tcp_recv_exit(void) | |
354 | { | |
355 | kmem_cache_destroy(rds_tcp_incoming_slab); | |
356 | } |