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5c115590 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/gfp.h> |
5c115590 AG |
35 | #include <net/sock.h> |
36 | #include <linux/in.h> | |
37 | #include <linux/list.h> | |
38 | ||
39 | #include "rds.h" | |
40 | #include "rdma.h" | |
41 | ||
42 | /* When transmitting messages in rds_send_xmit, we need to emerge from | |
43 | * time to time and briefly release the CPU. Otherwise the softlock watchdog | |
44 | * will kick our shin. | |
45 | * Also, it seems fairer to not let one busy connection stall all the | |
46 | * others. | |
47 | * | |
48 | * send_batch_count is the number of times we'll loop in send_xmit. Setting | |
49 | * it to 0 will restore the old behavior (where we looped until we had | |
50 | * drained the queue). | |
51 | */ | |
52 | static int send_batch_count = 64; | |
53 | module_param(send_batch_count, int, 0444); | |
54 | MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue"); | |
55 | ||
56 | /* | |
57 | * Reset the send state. Caller must hold c_send_lock when calling here. | |
58 | */ | |
59 | void rds_send_reset(struct rds_connection *conn) | |
60 | { | |
61 | struct rds_message *rm, *tmp; | |
62 | unsigned long flags; | |
63 | ||
64 | if (conn->c_xmit_rm) { | |
65 | /* Tell the user the RDMA op is no longer mapped by the | |
66 | * transport. This isn't entirely true (it's flushed out | |
67 | * independently) but as the connection is down, there's | |
68 | * no ongoing RDMA to/from that memory */ | |
69 | rds_message_unmapped(conn->c_xmit_rm); | |
70 | rds_message_put(conn->c_xmit_rm); | |
71 | conn->c_xmit_rm = NULL; | |
72 | } | |
73 | conn->c_xmit_sg = 0; | |
74 | conn->c_xmit_hdr_off = 0; | |
75 | conn->c_xmit_data_off = 0; | |
76 | conn->c_xmit_rdma_sent = 0; | |
77 | ||
78 | conn->c_map_queued = 0; | |
79 | ||
80 | conn->c_unacked_packets = rds_sysctl_max_unacked_packets; | |
81 | conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes; | |
82 | ||
83 | /* Mark messages as retransmissions, and move them to the send q */ | |
84 | spin_lock_irqsave(&conn->c_lock, flags); | |
85 | list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) { | |
86 | set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags); | |
87 | set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags); | |
88 | } | |
89 | list_splice_init(&conn->c_retrans, &conn->c_send_queue); | |
90 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
91 | } | |
92 | ||
93 | /* | |
94 | * We're making the concious trade-off here to only send one message | |
95 | * down the connection at a time. | |
96 | * Pro: | |
97 | * - tx queueing is a simple fifo list | |
98 | * - reassembly is optional and easily done by transports per conn | |
99 | * - no per flow rx lookup at all, straight to the socket | |
100 | * - less per-frag memory and wire overhead | |
101 | * Con: | |
102 | * - queued acks can be delayed behind large messages | |
103 | * Depends: | |
104 | * - small message latency is higher behind queued large messages | |
105 | * - large message latency isn't starved by intervening small sends | |
106 | */ | |
107 | int rds_send_xmit(struct rds_connection *conn) | |
108 | { | |
109 | struct rds_message *rm; | |
110 | unsigned long flags; | |
111 | unsigned int tmp; | |
112 | unsigned int send_quota = send_batch_count; | |
113 | struct scatterlist *sg; | |
114 | int ret = 0; | |
115 | int was_empty = 0; | |
116 | LIST_HEAD(to_be_dropped); | |
117 | ||
118 | /* | |
119 | * sendmsg calls here after having queued its message on the send | |
120 | * queue. We only have one task feeding the connection at a time. If | |
121 | * another thread is already feeding the queue then we back off. This | |
122 | * avoids blocking the caller and trading per-connection data between | |
123 | * caches per message. | |
124 | * | |
125 | * The sem holder will issue a retry if they notice that someone queued | |
126 | * a message after they stopped walking the send queue but before they | |
127 | * dropped the sem. | |
128 | */ | |
129 | if (!mutex_trylock(&conn->c_send_lock)) { | |
130 | rds_stats_inc(s_send_sem_contention); | |
131 | ret = -ENOMEM; | |
132 | goto out; | |
133 | } | |
134 | ||
135 | if (conn->c_trans->xmit_prepare) | |
136 | conn->c_trans->xmit_prepare(conn); | |
137 | ||
138 | /* | |
139 | * spin trying to push headers and data down the connection until | |
140 | * the connection doens't make forward progress. | |
141 | */ | |
142 | while (--send_quota) { | |
143 | /* | |
144 | * See if need to send a congestion map update if we're | |
145 | * between sending messages. The send_sem protects our sole | |
146 | * use of c_map_offset and _bytes. | |
147 | * Note this is used only by transports that define a special | |
148 | * xmit_cong_map function. For all others, we create allocate | |
149 | * a cong_map message and treat it just like any other send. | |
150 | */ | |
151 | if (conn->c_map_bytes) { | |
152 | ret = conn->c_trans->xmit_cong_map(conn, conn->c_lcong, | |
153 | conn->c_map_offset); | |
154 | if (ret <= 0) | |
155 | break; | |
156 | ||
157 | conn->c_map_offset += ret; | |
158 | conn->c_map_bytes -= ret; | |
159 | if (conn->c_map_bytes) | |
160 | continue; | |
161 | } | |
162 | ||
163 | /* If we're done sending the current message, clear the | |
164 | * offset and S/G temporaries. | |
165 | */ | |
166 | rm = conn->c_xmit_rm; | |
167 | if (rm != NULL && | |
168 | conn->c_xmit_hdr_off == sizeof(struct rds_header) && | |
169 | conn->c_xmit_sg == rm->m_nents) { | |
170 | conn->c_xmit_rm = NULL; | |
171 | conn->c_xmit_sg = 0; | |
172 | conn->c_xmit_hdr_off = 0; | |
173 | conn->c_xmit_data_off = 0; | |
174 | conn->c_xmit_rdma_sent = 0; | |
175 | ||
176 | /* Release the reference to the previous message. */ | |
177 | rds_message_put(rm); | |
178 | rm = NULL; | |
179 | } | |
180 | ||
181 | /* If we're asked to send a cong map update, do so. | |
182 | */ | |
183 | if (rm == NULL && test_and_clear_bit(0, &conn->c_map_queued)) { | |
184 | if (conn->c_trans->xmit_cong_map != NULL) { | |
185 | conn->c_map_offset = 0; | |
186 | conn->c_map_bytes = sizeof(struct rds_header) + | |
187 | RDS_CONG_MAP_BYTES; | |
188 | continue; | |
189 | } | |
190 | ||
191 | rm = rds_cong_update_alloc(conn); | |
192 | if (IS_ERR(rm)) { | |
193 | ret = PTR_ERR(rm); | |
194 | break; | |
195 | } | |
196 | ||
197 | conn->c_xmit_rm = rm; | |
198 | } | |
199 | ||
200 | /* | |
201 | * Grab the next message from the send queue, if there is one. | |
202 | * | |
203 | * c_xmit_rm holds a ref while we're sending this message down | |
204 | * the connction. We can use this ref while holding the | |
205 | * send_sem.. rds_send_reset() is serialized with it. | |
206 | */ | |
207 | if (rm == NULL) { | |
208 | unsigned int len; | |
209 | ||
210 | spin_lock_irqsave(&conn->c_lock, flags); | |
211 | ||
212 | if (!list_empty(&conn->c_send_queue)) { | |
213 | rm = list_entry(conn->c_send_queue.next, | |
214 | struct rds_message, | |
215 | m_conn_item); | |
216 | rds_message_addref(rm); | |
217 | ||
218 | /* | |
219 | * Move the message from the send queue to the retransmit | |
220 | * list right away. | |
221 | */ | |
222 | list_move_tail(&rm->m_conn_item, &conn->c_retrans); | |
223 | } | |
224 | ||
225 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
226 | ||
227 | if (rm == NULL) { | |
228 | was_empty = 1; | |
229 | break; | |
230 | } | |
231 | ||
232 | /* Unfortunately, the way Infiniband deals with | |
233 | * RDMA to a bad MR key is by moving the entire | |
234 | * queue pair to error state. We cold possibly | |
235 | * recover from that, but right now we drop the | |
236 | * connection. | |
237 | * Therefore, we never retransmit messages with RDMA ops. | |
238 | */ | |
f64f9e71 JP |
239 | if (rm->m_rdma_op && |
240 | test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) { | |
5c115590 AG |
241 | spin_lock_irqsave(&conn->c_lock, flags); |
242 | if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) | |
243 | list_move(&rm->m_conn_item, &to_be_dropped); | |
244 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
245 | rds_message_put(rm); | |
246 | continue; | |
247 | } | |
248 | ||
249 | /* Require an ACK every once in a while */ | |
250 | len = ntohl(rm->m_inc.i_hdr.h_len); | |
f64f9e71 JP |
251 | if (conn->c_unacked_packets == 0 || |
252 | conn->c_unacked_bytes < len) { | |
5c115590 AG |
253 | __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags); |
254 | ||
255 | conn->c_unacked_packets = rds_sysctl_max_unacked_packets; | |
256 | conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes; | |
257 | rds_stats_inc(s_send_ack_required); | |
258 | } else { | |
259 | conn->c_unacked_bytes -= len; | |
260 | conn->c_unacked_packets--; | |
261 | } | |
262 | ||
263 | conn->c_xmit_rm = rm; | |
264 | } | |
265 | ||
266 | /* | |
267 | * Try and send an rdma message. Let's see if we can | |
268 | * keep this simple and require that the transport either | |
269 | * send the whole rdma or none of it. | |
270 | */ | |
271 | if (rm->m_rdma_op && !conn->c_xmit_rdma_sent) { | |
272 | ret = conn->c_trans->xmit_rdma(conn, rm->m_rdma_op); | |
273 | if (ret) | |
274 | break; | |
275 | conn->c_xmit_rdma_sent = 1; | |
276 | /* The transport owns the mapped memory for now. | |
277 | * You can't unmap it while it's on the send queue */ | |
278 | set_bit(RDS_MSG_MAPPED, &rm->m_flags); | |
279 | } | |
280 | ||
281 | if (conn->c_xmit_hdr_off < sizeof(struct rds_header) || | |
282 | conn->c_xmit_sg < rm->m_nents) { | |
283 | ret = conn->c_trans->xmit(conn, rm, | |
284 | conn->c_xmit_hdr_off, | |
285 | conn->c_xmit_sg, | |
286 | conn->c_xmit_data_off); | |
287 | if (ret <= 0) | |
288 | break; | |
289 | ||
290 | if (conn->c_xmit_hdr_off < sizeof(struct rds_header)) { | |
291 | tmp = min_t(int, ret, | |
292 | sizeof(struct rds_header) - | |
293 | conn->c_xmit_hdr_off); | |
294 | conn->c_xmit_hdr_off += tmp; | |
295 | ret -= tmp; | |
296 | } | |
297 | ||
298 | sg = &rm->m_sg[conn->c_xmit_sg]; | |
299 | while (ret) { | |
300 | tmp = min_t(int, ret, sg->length - | |
301 | conn->c_xmit_data_off); | |
302 | conn->c_xmit_data_off += tmp; | |
303 | ret -= tmp; | |
304 | if (conn->c_xmit_data_off == sg->length) { | |
305 | conn->c_xmit_data_off = 0; | |
306 | sg++; | |
307 | conn->c_xmit_sg++; | |
308 | BUG_ON(ret != 0 && | |
309 | conn->c_xmit_sg == rm->m_nents); | |
310 | } | |
311 | } | |
312 | } | |
313 | } | |
314 | ||
315 | /* Nuke any messages we decided not to retransmit. */ | |
316 | if (!list_empty(&to_be_dropped)) | |
317 | rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED); | |
318 | ||
319 | if (conn->c_trans->xmit_complete) | |
320 | conn->c_trans->xmit_complete(conn); | |
321 | ||
322 | /* | |
323 | * We might be racing with another sender who queued a message but | |
324 | * backed off on noticing that we held the c_send_lock. If we check | |
325 | * for queued messages after dropping the sem then either we'll | |
326 | * see the queued message or the queuer will get the sem. If we | |
327 | * notice the queued message then we trigger an immediate retry. | |
328 | * | |
329 | * We need to be careful only to do this when we stopped processing | |
330 | * the send queue because it was empty. It's the only way we | |
331 | * stop processing the loop when the transport hasn't taken | |
332 | * responsibility for forward progress. | |
333 | */ | |
334 | mutex_unlock(&conn->c_send_lock); | |
335 | ||
336 | if (conn->c_map_bytes || (send_quota == 0 && !was_empty)) { | |
337 | /* We exhausted the send quota, but there's work left to | |
338 | * do. Return and (re-)schedule the send worker. | |
339 | */ | |
340 | ret = -EAGAIN; | |
341 | } | |
342 | ||
343 | if (ret == 0 && was_empty) { | |
344 | /* A simple bit test would be way faster than taking the | |
345 | * spin lock */ | |
346 | spin_lock_irqsave(&conn->c_lock, flags); | |
347 | if (!list_empty(&conn->c_send_queue)) { | |
348 | rds_stats_inc(s_send_sem_queue_raced); | |
349 | ret = -EAGAIN; | |
350 | } | |
351 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
352 | } | |
353 | out: | |
354 | return ret; | |
355 | } | |
356 | ||
357 | static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm) | |
358 | { | |
359 | u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len); | |
360 | ||
361 | assert_spin_locked(&rs->rs_lock); | |
362 | ||
363 | BUG_ON(rs->rs_snd_bytes < len); | |
364 | rs->rs_snd_bytes -= len; | |
365 | ||
366 | if (rs->rs_snd_bytes == 0) | |
367 | rds_stats_inc(s_send_queue_empty); | |
368 | } | |
369 | ||
370 | static inline int rds_send_is_acked(struct rds_message *rm, u64 ack, | |
371 | is_acked_func is_acked) | |
372 | { | |
373 | if (is_acked) | |
374 | return is_acked(rm, ack); | |
375 | return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack; | |
376 | } | |
377 | ||
378 | /* | |
379 | * Returns true if there are no messages on the send and retransmit queues | |
380 | * which have a sequence number greater than or equal to the given sequence | |
381 | * number. | |
382 | */ | |
383 | int rds_send_acked_before(struct rds_connection *conn, u64 seq) | |
384 | { | |
385 | struct rds_message *rm, *tmp; | |
386 | int ret = 1; | |
387 | ||
388 | spin_lock(&conn->c_lock); | |
389 | ||
390 | list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) { | |
391 | if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq) | |
392 | ret = 0; | |
393 | break; | |
394 | } | |
395 | ||
396 | list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) { | |
397 | if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq) | |
398 | ret = 0; | |
399 | break; | |
400 | } | |
401 | ||
402 | spin_unlock(&conn->c_lock); | |
403 | ||
404 | return ret; | |
405 | } | |
406 | ||
407 | /* | |
408 | * This is pretty similar to what happens below in the ACK | |
409 | * handling code - except that we call here as soon as we get | |
410 | * the IB send completion on the RDMA op and the accompanying | |
411 | * message. | |
412 | */ | |
413 | void rds_rdma_send_complete(struct rds_message *rm, int status) | |
414 | { | |
415 | struct rds_sock *rs = NULL; | |
416 | struct rds_rdma_op *ro; | |
417 | struct rds_notifier *notifier; | |
418 | ||
419 | spin_lock(&rm->m_rs_lock); | |
420 | ||
421 | ro = rm->m_rdma_op; | |
f64f9e71 JP |
422 | if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) && |
423 | ro && ro->r_notify && ro->r_notifier) { | |
5c115590 AG |
424 | notifier = ro->r_notifier; |
425 | rs = rm->m_rs; | |
426 | sock_hold(rds_rs_to_sk(rs)); | |
427 | ||
428 | notifier->n_status = status; | |
429 | spin_lock(&rs->rs_lock); | |
430 | list_add_tail(¬ifier->n_list, &rs->rs_notify_queue); | |
431 | spin_unlock(&rs->rs_lock); | |
432 | ||
433 | ro->r_notifier = NULL; | |
434 | } | |
435 | ||
436 | spin_unlock(&rm->m_rs_lock); | |
437 | ||
438 | if (rs) { | |
439 | rds_wake_sk_sleep(rs); | |
440 | sock_put(rds_rs_to_sk(rs)); | |
441 | } | |
442 | } | |
616b757a | 443 | EXPORT_SYMBOL_GPL(rds_rdma_send_complete); |
5c115590 AG |
444 | |
445 | /* | |
446 | * This is the same as rds_rdma_send_complete except we | |
447 | * don't do any locking - we have all the ingredients (message, | |
448 | * socket, socket lock) and can just move the notifier. | |
449 | */ | |
450 | static inline void | |
451 | __rds_rdma_send_complete(struct rds_sock *rs, struct rds_message *rm, int status) | |
452 | { | |
453 | struct rds_rdma_op *ro; | |
454 | ||
455 | ro = rm->m_rdma_op; | |
456 | if (ro && ro->r_notify && ro->r_notifier) { | |
457 | ro->r_notifier->n_status = status; | |
458 | list_add_tail(&ro->r_notifier->n_list, &rs->rs_notify_queue); | |
459 | ro->r_notifier = NULL; | |
460 | } | |
461 | ||
462 | /* No need to wake the app - caller does this */ | |
463 | } | |
464 | ||
465 | /* | |
466 | * This is called from the IB send completion when we detect | |
467 | * a RDMA operation that failed with remote access error. | |
468 | * So speed is not an issue here. | |
469 | */ | |
470 | struct rds_message *rds_send_get_message(struct rds_connection *conn, | |
471 | struct rds_rdma_op *op) | |
472 | { | |
473 | struct rds_message *rm, *tmp, *found = NULL; | |
474 | unsigned long flags; | |
475 | ||
476 | spin_lock_irqsave(&conn->c_lock, flags); | |
477 | ||
478 | list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) { | |
479 | if (rm->m_rdma_op == op) { | |
480 | atomic_inc(&rm->m_refcount); | |
481 | found = rm; | |
482 | goto out; | |
483 | } | |
484 | } | |
485 | ||
486 | list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) { | |
487 | if (rm->m_rdma_op == op) { | |
488 | atomic_inc(&rm->m_refcount); | |
489 | found = rm; | |
490 | break; | |
491 | } | |
492 | } | |
493 | ||
494 | out: | |
495 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
496 | ||
497 | return found; | |
498 | } | |
616b757a | 499 | EXPORT_SYMBOL_GPL(rds_send_get_message); |
5c115590 AG |
500 | |
501 | /* | |
502 | * This removes messages from the socket's list if they're on it. The list | |
503 | * argument must be private to the caller, we must be able to modify it | |
504 | * without locks. The messages must have a reference held for their | |
505 | * position on the list. This function will drop that reference after | |
506 | * removing the messages from the 'messages' list regardless of if it found | |
507 | * the messages on the socket list or not. | |
508 | */ | |
509 | void rds_send_remove_from_sock(struct list_head *messages, int status) | |
510 | { | |
561c7df6 | 511 | unsigned long flags; |
5c115590 AG |
512 | struct rds_sock *rs = NULL; |
513 | struct rds_message *rm; | |
514 | ||
5c115590 | 515 | while (!list_empty(messages)) { |
561c7df6 AG |
516 | int was_on_sock = 0; |
517 | ||
5c115590 AG |
518 | rm = list_entry(messages->next, struct rds_message, |
519 | m_conn_item); | |
520 | list_del_init(&rm->m_conn_item); | |
521 | ||
522 | /* | |
523 | * If we see this flag cleared then we're *sure* that someone | |
524 | * else beat us to removing it from the sock. If we race | |
525 | * with their flag update we'll get the lock and then really | |
526 | * see that the flag has been cleared. | |
527 | * | |
528 | * The message spinlock makes sure nobody clears rm->m_rs | |
529 | * while we're messing with it. It does not prevent the | |
530 | * message from being removed from the socket, though. | |
531 | */ | |
561c7df6 | 532 | spin_lock_irqsave(&rm->m_rs_lock, flags); |
5c115590 AG |
533 | if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) |
534 | goto unlock_and_drop; | |
535 | ||
536 | if (rs != rm->m_rs) { | |
537 | if (rs) { | |
5c115590 AG |
538 | rds_wake_sk_sleep(rs); |
539 | sock_put(rds_rs_to_sk(rs)); | |
540 | } | |
541 | rs = rm->m_rs; | |
5c115590 AG |
542 | sock_hold(rds_rs_to_sk(rs)); |
543 | } | |
048c15e6 | 544 | spin_lock(&rs->rs_lock); |
5c115590 AG |
545 | |
546 | if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) { | |
547 | struct rds_rdma_op *ro = rm->m_rdma_op; | |
548 | struct rds_notifier *notifier; | |
549 | ||
550 | list_del_init(&rm->m_sock_item); | |
551 | rds_send_sndbuf_remove(rs, rm); | |
552 | ||
f64f9e71 | 553 | if (ro && ro->r_notifier && (status || ro->r_notify)) { |
5c115590 AG |
554 | notifier = ro->r_notifier; |
555 | list_add_tail(¬ifier->n_list, | |
556 | &rs->rs_notify_queue); | |
557 | if (!notifier->n_status) | |
558 | notifier->n_status = status; | |
559 | rm->m_rdma_op->r_notifier = NULL; | |
560 | } | |
561c7df6 | 561 | was_on_sock = 1; |
5c115590 AG |
562 | rm->m_rs = NULL; |
563 | } | |
048c15e6 | 564 | spin_unlock(&rs->rs_lock); |
5c115590 AG |
565 | |
566 | unlock_and_drop: | |
561c7df6 | 567 | spin_unlock_irqrestore(&rm->m_rs_lock, flags); |
5c115590 | 568 | rds_message_put(rm); |
561c7df6 AG |
569 | if (was_on_sock) |
570 | rds_message_put(rm); | |
5c115590 AG |
571 | } |
572 | ||
573 | if (rs) { | |
5c115590 AG |
574 | rds_wake_sk_sleep(rs); |
575 | sock_put(rds_rs_to_sk(rs)); | |
576 | } | |
5c115590 AG |
577 | } |
578 | ||
579 | /* | |
580 | * Transports call here when they've determined that the receiver queued | |
581 | * messages up to, and including, the given sequence number. Messages are | |
582 | * moved to the retrans queue when rds_send_xmit picks them off the send | |
583 | * queue. This means that in the TCP case, the message may not have been | |
584 | * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked | |
585 | * checks the RDS_MSG_HAS_ACK_SEQ bit. | |
586 | * | |
587 | * XXX It's not clear to me how this is safely serialized with socket | |
588 | * destruction. Maybe it should bail if it sees SOCK_DEAD. | |
589 | */ | |
590 | void rds_send_drop_acked(struct rds_connection *conn, u64 ack, | |
591 | is_acked_func is_acked) | |
592 | { | |
593 | struct rds_message *rm, *tmp; | |
594 | unsigned long flags; | |
595 | LIST_HEAD(list); | |
596 | ||
597 | spin_lock_irqsave(&conn->c_lock, flags); | |
598 | ||
599 | list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) { | |
600 | if (!rds_send_is_acked(rm, ack, is_acked)) | |
601 | break; | |
602 | ||
603 | list_move(&rm->m_conn_item, &list); | |
604 | clear_bit(RDS_MSG_ON_CONN, &rm->m_flags); | |
605 | } | |
606 | ||
607 | /* order flag updates with spin locks */ | |
608 | if (!list_empty(&list)) | |
609 | smp_mb__after_clear_bit(); | |
610 | ||
611 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
612 | ||
613 | /* now remove the messages from the sock list as needed */ | |
614 | rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS); | |
615 | } | |
616b757a | 616 | EXPORT_SYMBOL_GPL(rds_send_drop_acked); |
5c115590 AG |
617 | |
618 | void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) | |
619 | { | |
620 | struct rds_message *rm, *tmp; | |
621 | struct rds_connection *conn; | |
f1cffcbf | 622 | unsigned long flags, flags2; |
5c115590 AG |
623 | LIST_HEAD(list); |
624 | int wake = 0; | |
625 | ||
626 | /* get all the messages we're dropping under the rs lock */ | |
627 | spin_lock_irqsave(&rs->rs_lock, flags); | |
628 | ||
629 | list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) { | |
630 | if (dest && (dest->sin_addr.s_addr != rm->m_daddr || | |
631 | dest->sin_port != rm->m_inc.i_hdr.h_dport)) | |
632 | continue; | |
633 | ||
634 | wake = 1; | |
635 | list_move(&rm->m_sock_item, &list); | |
636 | rds_send_sndbuf_remove(rs, rm); | |
637 | clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags); | |
5c115590 AG |
638 | } |
639 | ||
640 | /* order flag updates with the rs lock */ | |
641 | if (wake) | |
642 | smp_mb__after_clear_bit(); | |
643 | ||
644 | spin_unlock_irqrestore(&rs->rs_lock, flags); | |
645 | ||
5c115590 AG |
646 | conn = NULL; |
647 | ||
648 | /* now remove the messages from the conn list as needed */ | |
649 | list_for_each_entry(rm, &list, m_sock_item) { | |
650 | /* We do this here rather than in the loop above, so that | |
651 | * we don't have to nest m_rs_lock under rs->rs_lock */ | |
f1cffcbf | 652 | spin_lock_irqsave(&rm->m_rs_lock, flags2); |
550a8002 TY |
653 | /* If this is a RDMA operation, notify the app. */ |
654 | spin_lock(&rs->rs_lock); | |
655 | __rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED); | |
656 | spin_unlock(&rs->rs_lock); | |
5c115590 | 657 | rm->m_rs = NULL; |
f1cffcbf | 658 | spin_unlock_irqrestore(&rm->m_rs_lock, flags2); |
5c115590 AG |
659 | |
660 | /* | |
661 | * If we see this flag cleared then we're *sure* that someone | |
662 | * else beat us to removing it from the conn. If we race | |
663 | * with their flag update we'll get the lock and then really | |
664 | * see that the flag has been cleared. | |
665 | */ | |
666 | if (!test_bit(RDS_MSG_ON_CONN, &rm->m_flags)) | |
667 | continue; | |
668 | ||
669 | if (conn != rm->m_inc.i_conn) { | |
670 | if (conn) | |
671 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
672 | conn = rm->m_inc.i_conn; | |
673 | spin_lock_irqsave(&conn->c_lock, flags); | |
674 | } | |
675 | ||
676 | if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) { | |
677 | list_del_init(&rm->m_conn_item); | |
678 | rds_message_put(rm); | |
679 | } | |
680 | } | |
681 | ||
682 | if (conn) | |
683 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
684 | ||
550a8002 TY |
685 | if (wake) |
686 | rds_wake_sk_sleep(rs); | |
687 | ||
5c115590 AG |
688 | while (!list_empty(&list)) { |
689 | rm = list_entry(list.next, struct rds_message, m_sock_item); | |
690 | list_del_init(&rm->m_sock_item); | |
691 | ||
692 | rds_message_wait(rm); | |
693 | rds_message_put(rm); | |
694 | } | |
695 | } | |
696 | ||
697 | /* | |
698 | * we only want this to fire once so we use the callers 'queued'. It's | |
699 | * possible that another thread can race with us and remove the | |
700 | * message from the flow with RDS_CANCEL_SENT_TO. | |
701 | */ | |
702 | static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn, | |
703 | struct rds_message *rm, __be16 sport, | |
704 | __be16 dport, int *queued) | |
705 | { | |
706 | unsigned long flags; | |
707 | u32 len; | |
708 | ||
709 | if (*queued) | |
710 | goto out; | |
711 | ||
712 | len = be32_to_cpu(rm->m_inc.i_hdr.h_len); | |
713 | ||
714 | /* this is the only place which holds both the socket's rs_lock | |
715 | * and the connection's c_lock */ | |
716 | spin_lock_irqsave(&rs->rs_lock, flags); | |
717 | ||
718 | /* | |
719 | * If there is a little space in sndbuf, we don't queue anything, | |
720 | * and userspace gets -EAGAIN. But poll() indicates there's send | |
721 | * room. This can lead to bad behavior (spinning) if snd_bytes isn't | |
722 | * freed up by incoming acks. So we check the *old* value of | |
723 | * rs_snd_bytes here to allow the last msg to exceed the buffer, | |
724 | * and poll() now knows no more data can be sent. | |
725 | */ | |
726 | if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) { | |
727 | rs->rs_snd_bytes += len; | |
728 | ||
729 | /* let recv side know we are close to send space exhaustion. | |
730 | * This is probably not the optimal way to do it, as this | |
731 | * means we set the flag on *all* messages as soon as our | |
732 | * throughput hits a certain threshold. | |
733 | */ | |
734 | if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2) | |
735 | __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags); | |
736 | ||
737 | list_add_tail(&rm->m_sock_item, &rs->rs_send_queue); | |
738 | set_bit(RDS_MSG_ON_SOCK, &rm->m_flags); | |
739 | rds_message_addref(rm); | |
740 | rm->m_rs = rs; | |
741 | ||
742 | /* The code ordering is a little weird, but we're | |
743 | trying to minimize the time we hold c_lock */ | |
744 | rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0); | |
745 | rm->m_inc.i_conn = conn; | |
746 | rds_message_addref(rm); | |
747 | ||
748 | spin_lock(&conn->c_lock); | |
749 | rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++); | |
750 | list_add_tail(&rm->m_conn_item, &conn->c_send_queue); | |
751 | set_bit(RDS_MSG_ON_CONN, &rm->m_flags); | |
752 | spin_unlock(&conn->c_lock); | |
753 | ||
754 | rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n", | |
755 | rm, len, rs, rs->rs_snd_bytes, | |
756 | (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence)); | |
757 | ||
758 | *queued = 1; | |
759 | } | |
760 | ||
761 | spin_unlock_irqrestore(&rs->rs_lock, flags); | |
762 | out: | |
763 | return *queued; | |
764 | } | |
765 | ||
766 | static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm, | |
767 | struct msghdr *msg, int *allocated_mr) | |
768 | { | |
769 | struct cmsghdr *cmsg; | |
770 | int ret = 0; | |
771 | ||
772 | for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { | |
773 | if (!CMSG_OK(msg, cmsg)) | |
774 | return -EINVAL; | |
775 | ||
776 | if (cmsg->cmsg_level != SOL_RDS) | |
777 | continue; | |
778 | ||
779 | /* As a side effect, RDMA_DEST and RDMA_MAP will set | |
780 | * rm->m_rdma_cookie and rm->m_rdma_mr. | |
781 | */ | |
782 | switch (cmsg->cmsg_type) { | |
783 | case RDS_CMSG_RDMA_ARGS: | |
784 | ret = rds_cmsg_rdma_args(rs, rm, cmsg); | |
785 | break; | |
786 | ||
787 | case RDS_CMSG_RDMA_DEST: | |
788 | ret = rds_cmsg_rdma_dest(rs, rm, cmsg); | |
789 | break; | |
790 | ||
791 | case RDS_CMSG_RDMA_MAP: | |
792 | ret = rds_cmsg_rdma_map(rs, rm, cmsg); | |
793 | if (!ret) | |
794 | *allocated_mr = 1; | |
795 | break; | |
796 | ||
797 | default: | |
798 | return -EINVAL; | |
799 | } | |
800 | ||
801 | if (ret) | |
802 | break; | |
803 | } | |
804 | ||
805 | return ret; | |
806 | } | |
807 | ||
808 | int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, | |
809 | size_t payload_len) | |
810 | { | |
811 | struct sock *sk = sock->sk; | |
812 | struct rds_sock *rs = rds_sk_to_rs(sk); | |
813 | struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; | |
814 | __be32 daddr; | |
815 | __be16 dport; | |
816 | struct rds_message *rm = NULL; | |
817 | struct rds_connection *conn; | |
818 | int ret = 0; | |
819 | int queued = 0, allocated_mr = 0; | |
820 | int nonblock = msg->msg_flags & MSG_DONTWAIT; | |
1123fd73 | 821 | long timeo = sock_sndtimeo(sk, nonblock); |
5c115590 AG |
822 | |
823 | /* Mirror Linux UDP mirror of BSD error message compatibility */ | |
824 | /* XXX: Perhaps MSG_MORE someday */ | |
825 | if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) { | |
826 | printk(KERN_INFO "msg_flags 0x%08X\n", msg->msg_flags); | |
827 | ret = -EOPNOTSUPP; | |
828 | goto out; | |
829 | } | |
830 | ||
831 | if (msg->msg_namelen) { | |
832 | /* XXX fail non-unicast destination IPs? */ | |
833 | if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) { | |
834 | ret = -EINVAL; | |
835 | goto out; | |
836 | } | |
837 | daddr = usin->sin_addr.s_addr; | |
838 | dport = usin->sin_port; | |
839 | } else { | |
840 | /* We only care about consistency with ->connect() */ | |
841 | lock_sock(sk); | |
842 | daddr = rs->rs_conn_addr; | |
843 | dport = rs->rs_conn_port; | |
844 | release_sock(sk); | |
845 | } | |
846 | ||
847 | /* racing with another thread binding seems ok here */ | |
848 | if (daddr == 0 || rs->rs_bound_addr == 0) { | |
849 | ret = -ENOTCONN; /* XXX not a great errno */ | |
850 | goto out; | |
851 | } | |
852 | ||
853 | rm = rds_message_copy_from_user(msg->msg_iov, payload_len); | |
854 | if (IS_ERR(rm)) { | |
855 | ret = PTR_ERR(rm); | |
856 | rm = NULL; | |
857 | goto out; | |
858 | } | |
859 | ||
860 | rm->m_daddr = daddr; | |
861 | ||
5c115590 AG |
862 | /* rds_conn_create has a spinlock that runs with IRQ off. |
863 | * Caching the conn in the socket helps a lot. */ | |
864 | if (rs->rs_conn && rs->rs_conn->c_faddr == daddr) | |
865 | conn = rs->rs_conn; | |
866 | else { | |
867 | conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr, | |
868 | rs->rs_transport, | |
869 | sock->sk->sk_allocation); | |
870 | if (IS_ERR(conn)) { | |
871 | ret = PTR_ERR(conn); | |
872 | goto out; | |
873 | } | |
874 | rs->rs_conn = conn; | |
875 | } | |
876 | ||
49f69691 AG |
877 | /* Parse any control messages the user may have included. */ |
878 | ret = rds_cmsg_send(rs, rm, msg, &allocated_mr); | |
879 | if (ret) | |
880 | goto out; | |
881 | ||
f64f9e71 JP |
882 | if ((rm->m_rdma_cookie || rm->m_rdma_op) && |
883 | conn->c_trans->xmit_rdma == NULL) { | |
5c115590 AG |
884 | if (printk_ratelimit()) |
885 | printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n", | |
886 | rm->m_rdma_op, conn->c_trans->xmit_rdma); | |
887 | ret = -EOPNOTSUPP; | |
888 | goto out; | |
889 | } | |
890 | ||
891 | /* If the connection is down, trigger a connect. We may | |
892 | * have scheduled a delayed reconnect however - in this case | |
893 | * we should not interfere. | |
894 | */ | |
f64f9e71 JP |
895 | if (rds_conn_state(conn) == RDS_CONN_DOWN && |
896 | !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags)) | |
5c115590 AG |
897 | queue_delayed_work(rds_wq, &conn->c_conn_w, 0); |
898 | ||
899 | ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs); | |
b98ba52f AG |
900 | if (ret) { |
901 | rs->rs_seen_congestion = 1; | |
5c115590 | 902 | goto out; |
b98ba52f | 903 | } |
5c115590 AG |
904 | |
905 | while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port, | |
906 | dport, &queued)) { | |
907 | rds_stats_inc(s_send_queue_full); | |
908 | /* XXX make sure this is reasonable */ | |
909 | if (payload_len > rds_sk_sndbuf(rs)) { | |
910 | ret = -EMSGSIZE; | |
911 | goto out; | |
912 | } | |
913 | if (nonblock) { | |
914 | ret = -EAGAIN; | |
915 | goto out; | |
916 | } | |
917 | ||
aa395145 | 918 | timeo = wait_event_interruptible_timeout(*sk_sleep(sk), |
5c115590 AG |
919 | rds_send_queue_rm(rs, conn, rm, |
920 | rs->rs_bound_port, | |
921 | dport, | |
922 | &queued), | |
923 | timeo); | |
924 | rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo); | |
925 | if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT) | |
926 | continue; | |
927 | ||
928 | ret = timeo; | |
929 | if (ret == 0) | |
930 | ret = -ETIMEDOUT; | |
931 | goto out; | |
932 | } | |
933 | ||
934 | /* | |
935 | * By now we've committed to the send. We reuse rds_send_worker() | |
936 | * to retry sends in the rds thread if the transport asks us to. | |
937 | */ | |
938 | rds_stats_inc(s_send_queued); | |
939 | ||
940 | if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags)) | |
941 | rds_send_worker(&conn->c_send_w.work); | |
942 | ||
943 | rds_message_put(rm); | |
944 | return payload_len; | |
945 | ||
946 | out: | |
947 | /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly. | |
948 | * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN | |
949 | * or in any other way, we need to destroy the MR again */ | |
950 | if (allocated_mr) | |
951 | rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1); | |
952 | ||
953 | if (rm) | |
954 | rds_message_put(rm); | |
955 | return ret; | |
956 | } | |
957 | ||
958 | /* | |
959 | * Reply to a ping packet. | |
960 | */ | |
961 | int | |
962 | rds_send_pong(struct rds_connection *conn, __be16 dport) | |
963 | { | |
964 | struct rds_message *rm; | |
965 | unsigned long flags; | |
966 | int ret = 0; | |
967 | ||
968 | rm = rds_message_alloc(0, GFP_ATOMIC); | |
969 | if (rm == NULL) { | |
970 | ret = -ENOMEM; | |
971 | goto out; | |
972 | } | |
973 | ||
974 | rm->m_daddr = conn->c_faddr; | |
975 | ||
976 | /* If the connection is down, trigger a connect. We may | |
977 | * have scheduled a delayed reconnect however - in this case | |
978 | * we should not interfere. | |
979 | */ | |
f64f9e71 JP |
980 | if (rds_conn_state(conn) == RDS_CONN_DOWN && |
981 | !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags)) | |
5c115590 AG |
982 | queue_delayed_work(rds_wq, &conn->c_conn_w, 0); |
983 | ||
984 | ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL); | |
985 | if (ret) | |
986 | goto out; | |
987 | ||
988 | spin_lock_irqsave(&conn->c_lock, flags); | |
989 | list_add_tail(&rm->m_conn_item, &conn->c_send_queue); | |
990 | set_bit(RDS_MSG_ON_CONN, &rm->m_flags); | |
991 | rds_message_addref(rm); | |
992 | rm->m_inc.i_conn = conn; | |
993 | ||
994 | rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport, | |
995 | conn->c_next_tx_seq); | |
996 | conn->c_next_tx_seq++; | |
997 | spin_unlock_irqrestore(&conn->c_lock, flags); | |
998 | ||
999 | rds_stats_inc(s_send_queued); | |
1000 | rds_stats_inc(s_send_pong); | |
1001 | ||
1002 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); | |
1003 | rds_message_put(rm); | |
1004 | return 0; | |
1005 | ||
1006 | out: | |
1007 | if (rm) | |
1008 | rds_message_put(rm); | |
1009 | return ret; | |
1010 | } |