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