2 * Copyright (c) 2006 Oracle. All rights reserved.
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:
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
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.
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
33 #include <linux/kernel.h>
34 #include <linux/gfp.h>
37 #include <linux/list.h>
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
44 * Also, it seems fairer to not let one busy connection stall all the
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
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");
56 * Reset the send state. Caller must hold c_send_lock when calling here.
58 void rds_send_reset(struct rds_connection
*conn
)
60 struct rds_message
*rm
, *tmp
;
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
;
73 conn
->c_xmit_hdr_off
= 0;
74 conn
->c_xmit_data_off
= 0;
75 conn
->c_xmit_atomic_sent
= 0;
76 conn
->c_xmit_rdma_sent
= 0;
77 conn
->c_xmit_data_sent
= 0;
79 conn
->c_map_queued
= 0;
81 conn
->c_unacked_packets
= rds_sysctl_max_unacked_packets
;
82 conn
->c_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
84 /* Mark messages as retransmissions, and move them to the send q */
85 spin_lock_irqsave(&conn
->c_lock
, flags
);
86 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
87 set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
88 set_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
);
90 list_splice_init(&conn
->c_retrans
, &conn
->c_send_queue
);
91 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
95 * We're making the concious trade-off here to only send one message
96 * down the connection at a time.
98 * - tx queueing is a simple fifo list
99 * - reassembly is optional and easily done by transports per conn
100 * - no per flow rx lookup at all, straight to the socket
101 * - less per-frag memory and wire overhead
103 * - queued acks can be delayed behind large messages
105 * - small message latency is higher behind queued large messages
106 * - large message latency isn't starved by intervening small sends
108 int rds_send_xmit(struct rds_connection
*conn
)
110 struct rds_message
*rm
;
113 unsigned int send_quota
= send_batch_count
;
114 struct scatterlist
*sg
;
117 LIST_HEAD(to_be_dropped
);
119 if (!rds_conn_up(conn
))
123 * sendmsg calls here after having queued its message on the send
124 * queue. We only have one task feeding the connection at a time. If
125 * another thread is already feeding the queue then we back off. This
126 * avoids blocking the caller and trading per-connection data between
127 * caches per message.
129 if (!spin_trylock_irqsave(&conn
->c_send_lock
, flags
)) {
130 rds_stats_inc(s_send_lock_contention
);
135 if (conn
->c_trans
->xmit_prepare
)
136 conn
->c_trans
->xmit_prepare(conn
);
139 * spin trying to push headers and data down the connection until
140 * the connection doesn't make forward progress.
142 while (--send_quota
) {
144 rm
= conn
->c_xmit_rm
;
147 * If between sending messages, we can send a pending congestion
150 if (!rm
&& test_and_clear_bit(0, &conn
->c_map_queued
)) {
151 rm
= rds_cong_update_alloc(conn
);
156 rm
->data
.op_active
= 1;
158 conn
->c_xmit_rm
= rm
;
162 * If not already working on one, grab the next message.
164 * c_xmit_rm holds a ref while we're sending this message down
165 * the connction. We can use this ref while holding the
166 * send_sem.. rds_send_reset() is serialized with it.
171 spin_lock(&conn
->c_lock
);
173 if (!list_empty(&conn
->c_send_queue
)) {
174 rm
= list_entry(conn
->c_send_queue
.next
,
177 rds_message_addref(rm
);
180 * Move the message from the send queue to the retransmit
183 list_move_tail(&rm
->m_conn_item
, &conn
->c_retrans
);
186 spin_unlock(&conn
->c_lock
);
193 /* Unfortunately, the way Infiniband deals with
194 * RDMA to a bad MR key is by moving the entire
195 * queue pair to error state. We cold possibly
196 * recover from that, but right now we drop the
198 * Therefore, we never retransmit messages with RDMA ops.
200 if (rm
->rdma
.op_active
&&
201 test_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
)) {
202 spin_lock(&conn
->c_lock
);
203 if (test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
))
204 list_move(&rm
->m_conn_item
, &to_be_dropped
);
205 spin_unlock(&conn
->c_lock
);
209 /* Require an ACK every once in a while */
210 len
= ntohl(rm
->m_inc
.i_hdr
.h_len
);
211 if (conn
->c_unacked_packets
== 0 ||
212 conn
->c_unacked_bytes
< len
) {
213 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
215 conn
->c_unacked_packets
= rds_sysctl_max_unacked_packets
;
216 conn
->c_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
217 rds_stats_inc(s_send_ack_required
);
219 conn
->c_unacked_bytes
-= len
;
220 conn
->c_unacked_packets
--;
223 conn
->c_xmit_rm
= rm
;
226 /* The transport either sends the whole rdma or none of it */
227 if (rm
->rdma
.op_active
&& !conn
->c_xmit_rdma_sent
) {
228 rm
->m_final_op
= &rm
->rdma
;
229 ret
= conn
->c_trans
->xmit_rdma(conn
, &rm
->rdma
);
232 conn
->c_xmit_rdma_sent
= 1;
234 /* The transport owns the mapped memory for now.
235 * You can't unmap it while it's on the send queue */
236 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
239 if (rm
->atomic
.op_active
&& !conn
->c_xmit_atomic_sent
) {
240 rm
->m_final_op
= &rm
->atomic
;
241 ret
= conn
->c_trans
->xmit_atomic(conn
, &rm
->atomic
);
244 conn
->c_xmit_atomic_sent
= 1;
246 /* The transport owns the mapped memory for now.
247 * You can't unmap it while it's on the send queue */
248 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
252 * A number of cases require an RDS header to be sent
253 * even if there is no data.
254 * We permit 0-byte sends; rds-ping depends on this.
255 * However, if there are exclusively attached silent ops,
256 * we skip the hdr/data send, to enable silent operation.
258 if (rm
->data
.op_nents
== 0) {
260 int all_ops_are_silent
= 1;
262 ops_present
= (rm
->atomic
.op_active
|| rm
->rdma
.op_active
);
263 if (rm
->atomic
.op_active
&& !rm
->atomic
.op_silent
)
264 all_ops_are_silent
= 0;
265 if (rm
->rdma
.op_active
&& !rm
->rdma
.op_silent
)
266 all_ops_are_silent
= 0;
268 if (ops_present
&& all_ops_are_silent
269 && !rm
->m_rdma_cookie
)
270 rm
->data
.op_active
= 0;
273 if (rm
->data
.op_active
&& !conn
->c_xmit_data_sent
) {
274 rm
->m_final_op
= &rm
->data
;
275 ret
= conn
->c_trans
->xmit(conn
, rm
,
276 conn
->c_xmit_hdr_off
,
278 conn
->c_xmit_data_off
);
282 if (conn
->c_xmit_hdr_off
< sizeof(struct rds_header
)) {
283 tmp
= min_t(int, ret
,
284 sizeof(struct rds_header
) -
285 conn
->c_xmit_hdr_off
);
286 conn
->c_xmit_hdr_off
+= tmp
;
290 sg
= &rm
->data
.op_sg
[conn
->c_xmit_sg
];
292 tmp
= min_t(int, ret
, sg
->length
-
293 conn
->c_xmit_data_off
);
294 conn
->c_xmit_data_off
+= tmp
;
296 if (conn
->c_xmit_data_off
== sg
->length
) {
297 conn
->c_xmit_data_off
= 0;
301 conn
->c_xmit_sg
== rm
->data
.op_nents
);
305 if (conn
->c_xmit_hdr_off
== sizeof(struct rds_header
) &&
306 (conn
->c_xmit_sg
== rm
->data
.op_nents
))
307 conn
->c_xmit_data_sent
= 1;
311 * A rm will only take multiple times through this loop
312 * if there is a data op. Thus, if the data is sent (or there was
313 * none), then we're done with the rm.
315 if (!rm
->data
.op_active
|| conn
->c_xmit_data_sent
) {
316 conn
->c_xmit_rm
= NULL
;
318 conn
->c_xmit_hdr_off
= 0;
319 conn
->c_xmit_data_off
= 0;
320 conn
->c_xmit_rdma_sent
= 0;
321 conn
->c_xmit_atomic_sent
= 0;
322 conn
->c_xmit_data_sent
= 0;
328 if (conn
->c_trans
->xmit_complete
)
329 conn
->c_trans
->xmit_complete(conn
);
332 * We might be racing with another sender who queued a message but
333 * backed off on noticing that we held the c_send_lock. If we check
334 * for queued messages after dropping the sem then either we'll
335 * see the queued message or the queuer will get the sem. If we
336 * notice the queued message then we trigger an immediate retry.
338 * We need to be careful only to do this when we stopped processing
339 * the send queue because it was empty. It's the only way we
340 * stop processing the loop when the transport hasn't taken
341 * responsibility for forward progress.
343 spin_unlock_irqrestore(&conn
->c_send_lock
, flags
);
345 /* Nuke any messages we decided not to retransmit. */
346 if (!list_empty(&to_be_dropped
)) {
347 /* irqs on here, so we can put(), unlike above */
348 list_for_each_entry(rm
, &to_be_dropped
, m_conn_item
)
350 rds_send_remove_from_sock(&to_be_dropped
, RDS_RDMA_DROPPED
);
353 if (send_quota
== 0 && !was_empty
) {
354 /* We exhausted the send quota, but there's work left to
355 * do. Return and (re-)schedule the send worker.
360 if (ret
== 0 && was_empty
) {
361 /* A simple bit test would be way faster than taking the
363 spin_lock_irqsave(&conn
->c_lock
, flags
);
364 if (!list_empty(&conn
->c_send_queue
)) {
365 rds_stats_inc(s_send_lock_queue_raced
);
368 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
374 static void rds_send_sndbuf_remove(struct rds_sock
*rs
, struct rds_message
*rm
)
376 u32 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
378 assert_spin_locked(&rs
->rs_lock
);
380 BUG_ON(rs
->rs_snd_bytes
< len
);
381 rs
->rs_snd_bytes
-= len
;
383 if (rs
->rs_snd_bytes
== 0)
384 rds_stats_inc(s_send_queue_empty
);
387 static inline int rds_send_is_acked(struct rds_message
*rm
, u64 ack
,
388 is_acked_func is_acked
)
391 return is_acked(rm
, ack
);
392 return be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) <= ack
;
396 * Returns true if there are no messages on the send and retransmit queues
397 * which have a sequence number greater than or equal to the given sequence
400 int rds_send_acked_before(struct rds_connection
*conn
, u64 seq
)
402 struct rds_message
*rm
, *tmp
;
405 spin_lock(&conn
->c_lock
);
407 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
408 if (be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) < seq
)
413 list_for_each_entry_safe(rm
, tmp
, &conn
->c_send_queue
, m_conn_item
) {
414 if (be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) < seq
)
419 spin_unlock(&conn
->c_lock
);
425 * This is pretty similar to what happens below in the ACK
426 * handling code - except that we call here as soon as we get
427 * the IB send completion on the RDMA op and the accompanying
430 void rds_rdma_send_complete(struct rds_message
*rm
, int status
)
432 struct rds_sock
*rs
= NULL
;
433 struct rm_rdma_op
*ro
;
434 struct rds_notifier
*notifier
;
437 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
440 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
) &&
441 ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
442 notifier
= ro
->op_notifier
;
444 sock_hold(rds_rs_to_sk(rs
));
446 notifier
->n_status
= status
;
447 spin_lock(&rs
->rs_lock
);
448 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
449 spin_unlock(&rs
->rs_lock
);
451 ro
->op_notifier
= NULL
;
454 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
457 rds_wake_sk_sleep(rs
);
458 sock_put(rds_rs_to_sk(rs
));
461 EXPORT_SYMBOL_GPL(rds_rdma_send_complete
);
464 * Just like above, except looks at atomic op
466 void rds_atomic_send_complete(struct rds_message
*rm
, int status
)
468 struct rds_sock
*rs
= NULL
;
469 struct rm_atomic_op
*ao
;
470 struct rds_notifier
*notifier
;
473 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
476 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)
477 && ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
478 notifier
= ao
->op_notifier
;
480 sock_hold(rds_rs_to_sk(rs
));
482 notifier
->n_status
= status
;
483 spin_lock(&rs
->rs_lock
);
484 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
485 spin_unlock(&rs
->rs_lock
);
487 ao
->op_notifier
= NULL
;
490 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
493 rds_wake_sk_sleep(rs
);
494 sock_put(rds_rs_to_sk(rs
));
497 EXPORT_SYMBOL_GPL(rds_atomic_send_complete
);
500 * This is the same as rds_rdma_send_complete except we
501 * don't do any locking - we have all the ingredients (message,
502 * socket, socket lock) and can just move the notifier.
505 __rds_send_complete(struct rds_sock
*rs
, struct rds_message
*rm
, int status
)
507 struct rm_rdma_op
*ro
;
508 struct rm_atomic_op
*ao
;
511 if (ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
512 ro
->op_notifier
->n_status
= status
;
513 list_add_tail(&ro
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
514 ro
->op_notifier
= NULL
;
518 if (ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
519 ao
->op_notifier
->n_status
= status
;
520 list_add_tail(&ao
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
521 ao
->op_notifier
= NULL
;
524 /* No need to wake the app - caller does this */
528 * This is called from the IB send completion when we detect
529 * a RDMA operation that failed with remote access error.
530 * So speed is not an issue here.
532 struct rds_message
*rds_send_get_message(struct rds_connection
*conn
,
533 struct rm_rdma_op
*op
)
535 struct rds_message
*rm
, *tmp
, *found
= NULL
;
538 spin_lock_irqsave(&conn
->c_lock
, flags
);
540 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
541 if (&rm
->rdma
== op
) {
542 atomic_inc(&rm
->m_refcount
);
548 list_for_each_entry_safe(rm
, tmp
, &conn
->c_send_queue
, m_conn_item
) {
549 if (&rm
->rdma
== op
) {
550 atomic_inc(&rm
->m_refcount
);
557 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
561 EXPORT_SYMBOL_GPL(rds_send_get_message
);
564 * This removes messages from the socket's list if they're on it. The list
565 * argument must be private to the caller, we must be able to modify it
566 * without locks. The messages must have a reference held for their
567 * position on the list. This function will drop that reference after
568 * removing the messages from the 'messages' list regardless of if it found
569 * the messages on the socket list or not.
571 void rds_send_remove_from_sock(struct list_head
*messages
, int status
)
574 struct rds_sock
*rs
= NULL
;
575 struct rds_message
*rm
;
577 while (!list_empty(messages
)) {
580 rm
= list_entry(messages
->next
, struct rds_message
,
582 list_del_init(&rm
->m_conn_item
);
585 * If we see this flag cleared then we're *sure* that someone
586 * else beat us to removing it from the sock. If we race
587 * with their flag update we'll get the lock and then really
588 * see that the flag has been cleared.
590 * The message spinlock makes sure nobody clears rm->m_rs
591 * while we're messing with it. It does not prevent the
592 * message from being removed from the socket, though.
594 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
595 if (!test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
))
596 goto unlock_and_drop
;
598 if (rs
!= rm
->m_rs
) {
600 rds_wake_sk_sleep(rs
);
601 sock_put(rds_rs_to_sk(rs
));
604 sock_hold(rds_rs_to_sk(rs
));
606 spin_lock(&rs
->rs_lock
);
608 if (test_and_clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)) {
609 struct rm_rdma_op
*ro
= &rm
->rdma
;
610 struct rds_notifier
*notifier
;
612 list_del_init(&rm
->m_sock_item
);
613 rds_send_sndbuf_remove(rs
, rm
);
615 if (ro
->op_active
&& ro
->op_notifier
&&
616 (ro
->op_notify
|| (ro
->op_recverr
&& status
))) {
617 notifier
= ro
->op_notifier
;
618 list_add_tail(¬ifier
->n_list
,
619 &rs
->rs_notify_queue
);
620 if (!notifier
->n_status
)
621 notifier
->n_status
= status
;
622 rm
->rdma
.op_notifier
= NULL
;
627 spin_unlock(&rs
->rs_lock
);
630 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
637 rds_wake_sk_sleep(rs
);
638 sock_put(rds_rs_to_sk(rs
));
643 * Transports call here when they've determined that the receiver queued
644 * messages up to, and including, the given sequence number. Messages are
645 * moved to the retrans queue when rds_send_xmit picks them off the send
646 * queue. This means that in the TCP case, the message may not have been
647 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
648 * checks the RDS_MSG_HAS_ACK_SEQ bit.
650 * XXX It's not clear to me how this is safely serialized with socket
651 * destruction. Maybe it should bail if it sees SOCK_DEAD.
653 void rds_send_drop_acked(struct rds_connection
*conn
, u64 ack
,
654 is_acked_func is_acked
)
656 struct rds_message
*rm
, *tmp
;
660 spin_lock_irqsave(&conn
->c_lock
, flags
);
662 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
663 if (!rds_send_is_acked(rm
, ack
, is_acked
))
666 list_move(&rm
->m_conn_item
, &list
);
667 clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
670 /* order flag updates with spin locks */
671 if (!list_empty(&list
))
672 smp_mb__after_clear_bit();
674 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
676 /* now remove the messages from the sock list as needed */
677 rds_send_remove_from_sock(&list
, RDS_RDMA_SUCCESS
);
679 EXPORT_SYMBOL_GPL(rds_send_drop_acked
);
681 void rds_send_drop_to(struct rds_sock
*rs
, struct sockaddr_in
*dest
)
683 struct rds_message
*rm
, *tmp
;
684 struct rds_connection
*conn
;
688 /* get all the messages we're dropping under the rs lock */
689 spin_lock_irqsave(&rs
->rs_lock
, flags
);
691 list_for_each_entry_safe(rm
, tmp
, &rs
->rs_send_queue
, m_sock_item
) {
692 if (dest
&& (dest
->sin_addr
.s_addr
!= rm
->m_daddr
||
693 dest
->sin_port
!= rm
->m_inc
.i_hdr
.h_dport
))
696 list_move(&rm
->m_sock_item
, &list
);
697 rds_send_sndbuf_remove(rs
, rm
);
698 clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
701 /* order flag updates with the rs lock */
702 smp_mb__after_clear_bit();
704 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
706 if (list_empty(&list
))
709 /* Remove the messages from the conn */
710 list_for_each_entry(rm
, &list
, m_sock_item
) {
712 conn
= rm
->m_inc
.i_conn
;
714 spin_lock_irqsave(&conn
->c_lock
, flags
);
716 * Maybe someone else beat us to removing rm from the conn.
717 * If we race with their flag update we'll get the lock and
718 * then really see that the flag has been cleared.
720 if (!test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
)) {
721 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
724 list_del_init(&rm
->m_conn_item
);
725 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
728 * Couldn't grab m_rs_lock in top loop (lock ordering),
731 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
733 spin_lock(&rs
->rs_lock
);
734 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
735 spin_unlock(&rs
->rs_lock
);
738 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
743 rds_wake_sk_sleep(rs
);
745 while (!list_empty(&list
)) {
746 rm
= list_entry(list
.next
, struct rds_message
, m_sock_item
);
747 list_del_init(&rm
->m_sock_item
);
749 rds_message_wait(rm
);
755 * we only want this to fire once so we use the callers 'queued'. It's
756 * possible that another thread can race with us and remove the
757 * message from the flow with RDS_CANCEL_SENT_TO.
759 static int rds_send_queue_rm(struct rds_sock
*rs
, struct rds_connection
*conn
,
760 struct rds_message
*rm
, __be16 sport
,
761 __be16 dport
, int *queued
)
769 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
771 /* this is the only place which holds both the socket's rs_lock
772 * and the connection's c_lock */
773 spin_lock_irqsave(&rs
->rs_lock
, flags
);
776 * If there is a little space in sndbuf, we don't queue anything,
777 * and userspace gets -EAGAIN. But poll() indicates there's send
778 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
779 * freed up by incoming acks. So we check the *old* value of
780 * rs_snd_bytes here to allow the last msg to exceed the buffer,
781 * and poll() now knows no more data can be sent.
783 if (rs
->rs_snd_bytes
< rds_sk_sndbuf(rs
)) {
784 rs
->rs_snd_bytes
+= len
;
786 /* let recv side know we are close to send space exhaustion.
787 * This is probably not the optimal way to do it, as this
788 * means we set the flag on *all* messages as soon as our
789 * throughput hits a certain threshold.
791 if (rs
->rs_snd_bytes
>= rds_sk_sndbuf(rs
) / 2)
792 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
794 list_add_tail(&rm
->m_sock_item
, &rs
->rs_send_queue
);
795 set_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
796 rds_message_addref(rm
);
799 /* The code ordering is a little weird, but we're
800 trying to minimize the time we hold c_lock */
801 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
, 0);
802 rm
->m_inc
.i_conn
= conn
;
803 rds_message_addref(rm
);
805 spin_lock(&conn
->c_lock
);
806 rm
->m_inc
.i_hdr
.h_sequence
= cpu_to_be64(conn
->c_next_tx_seq
++);
807 list_add_tail(&rm
->m_conn_item
, &conn
->c_send_queue
);
808 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
809 spin_unlock(&conn
->c_lock
);
811 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
812 rm
, len
, rs
, rs
->rs_snd_bytes
,
813 (unsigned long long)be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
));
818 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
824 * rds_message is getting to be quite complicated, and we'd like to allocate
825 * it all in one go. This figures out how big it needs to be up front.
827 static int rds_rm_size(struct msghdr
*msg
, int data_len
)
829 struct cmsghdr
*cmsg
;
834 for (cmsg
= CMSG_FIRSTHDR(msg
); cmsg
; cmsg
= CMSG_NXTHDR(msg
, cmsg
)) {
835 if (!CMSG_OK(msg
, cmsg
))
838 if (cmsg
->cmsg_level
!= SOL_RDS
)
841 switch (cmsg
->cmsg_type
) {
842 case RDS_CMSG_RDMA_ARGS
:
844 retval
= rds_rdma_extra_size(CMSG_DATA(cmsg
));
851 case RDS_CMSG_RDMA_DEST
:
852 case RDS_CMSG_RDMA_MAP
:
854 /* these are valid but do no add any size */
857 case RDS_CMSG_ATOMIC_CSWP
:
858 case RDS_CMSG_ATOMIC_FADD
:
860 size
+= sizeof(struct scatterlist
);
869 size
+= ceil(data_len
, PAGE_SIZE
) * sizeof(struct scatterlist
);
871 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
872 if (cmsg_groups
== 3)
878 static int rds_cmsg_send(struct rds_sock
*rs
, struct rds_message
*rm
,
879 struct msghdr
*msg
, int *allocated_mr
)
881 struct cmsghdr
*cmsg
;
884 for (cmsg
= CMSG_FIRSTHDR(msg
); cmsg
; cmsg
= CMSG_NXTHDR(msg
, cmsg
)) {
885 if (!CMSG_OK(msg
, cmsg
))
888 if (cmsg
->cmsg_level
!= SOL_RDS
)
891 /* As a side effect, RDMA_DEST and RDMA_MAP will set
892 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
894 switch (cmsg
->cmsg_type
) {
895 case RDS_CMSG_RDMA_ARGS
:
896 ret
= rds_cmsg_rdma_args(rs
, rm
, cmsg
);
899 case RDS_CMSG_RDMA_DEST
:
900 ret
= rds_cmsg_rdma_dest(rs
, rm
, cmsg
);
903 case RDS_CMSG_RDMA_MAP
:
904 ret
= rds_cmsg_rdma_map(rs
, rm
, cmsg
);
908 case RDS_CMSG_ATOMIC_CSWP
:
909 case RDS_CMSG_ATOMIC_FADD
:
910 ret
= rds_cmsg_atomic(rs
, rm
, cmsg
);
924 int rds_sendmsg(struct kiocb
*iocb
, struct socket
*sock
, struct msghdr
*msg
,
927 struct sock
*sk
= sock
->sk
;
928 struct rds_sock
*rs
= rds_sk_to_rs(sk
);
929 struct sockaddr_in
*usin
= (struct sockaddr_in
*)msg
->msg_name
;
932 struct rds_message
*rm
= NULL
;
933 struct rds_connection
*conn
;
935 int queued
= 0, allocated_mr
= 0;
936 int nonblock
= msg
->msg_flags
& MSG_DONTWAIT
;
937 long timeo
= sock_sndtimeo(sk
, nonblock
);
939 /* Mirror Linux UDP mirror of BSD error message compatibility */
940 /* XXX: Perhaps MSG_MORE someday */
941 if (msg
->msg_flags
& ~(MSG_DONTWAIT
| MSG_CMSG_COMPAT
)) {
942 printk(KERN_INFO
"msg_flags 0x%08X\n", msg
->msg_flags
);
947 if (msg
->msg_namelen
) {
948 /* XXX fail non-unicast destination IPs? */
949 if (msg
->msg_namelen
< sizeof(*usin
) || usin
->sin_family
!= AF_INET
) {
953 daddr
= usin
->sin_addr
.s_addr
;
954 dport
= usin
->sin_port
;
956 /* We only care about consistency with ->connect() */
958 daddr
= rs
->rs_conn_addr
;
959 dport
= rs
->rs_conn_port
;
963 /* racing with another thread binding seems ok here */
964 if (daddr
== 0 || rs
->rs_bound_addr
== 0) {
965 ret
= -ENOTCONN
; /* XXX not a great errno */
969 /* size of rm including all sgs */
970 ret
= rds_rm_size(msg
, payload_len
);
974 rm
= rds_message_alloc(ret
, GFP_KERNEL
);
980 /* Attach data to the rm */
982 rm
->data
.op_sg
= rds_message_alloc_sgs(rm
, ceil(payload_len
, PAGE_SIZE
));
983 ret
= rds_message_copy_from_user(rm
, msg
->msg_iov
, payload_len
);
987 rm
->data
.op_active
= 1;
991 /* rds_conn_create has a spinlock that runs with IRQ off.
992 * Caching the conn in the socket helps a lot. */
993 if (rs
->rs_conn
&& rs
->rs_conn
->c_faddr
== daddr
)
996 conn
= rds_conn_create_outgoing(rs
->rs_bound_addr
, daddr
,
998 sock
->sk
->sk_allocation
);
1000 ret
= PTR_ERR(conn
);
1006 /* Parse any control messages the user may have included. */
1007 ret
= rds_cmsg_send(rs
, rm
, msg
, &allocated_mr
);
1011 if (rm
->rdma
.op_active
&& !conn
->c_trans
->xmit_rdma
) {
1012 if (printk_ratelimit())
1013 printk(KERN_NOTICE
"rdma_op %p conn xmit_rdma %p\n",
1014 &rm
->rdma
, conn
->c_trans
->xmit_rdma
);
1019 if (rm
->atomic
.op_active
&& !conn
->c_trans
->xmit_atomic
) {
1020 if (printk_ratelimit())
1021 printk(KERN_NOTICE
"atomic_op %p conn xmit_atomic %p\n",
1022 &rm
->atomic
, conn
->c_trans
->xmit_atomic
);
1027 /* If the connection is down, trigger a connect. We may
1028 * have scheduled a delayed reconnect however - in this case
1029 * we should not interfere.
1031 if (rds_conn_state(conn
) == RDS_CONN_DOWN
&&
1032 !test_and_set_bit(RDS_RECONNECT_PENDING
, &conn
->c_flags
))
1033 queue_delayed_work(rds_wq
, &conn
->c_conn_w
, 0);
1035 ret
= rds_cong_wait(conn
->c_fcong
, dport
, nonblock
, rs
);
1037 rs
->rs_seen_congestion
= 1;
1041 while (!rds_send_queue_rm(rs
, conn
, rm
, rs
->rs_bound_port
,
1043 rds_stats_inc(s_send_queue_full
);
1044 /* XXX make sure this is reasonable */
1045 if (payload_len
> rds_sk_sndbuf(rs
)) {
1054 timeo
= wait_event_interruptible_timeout(*sk_sleep(sk
),
1055 rds_send_queue_rm(rs
, conn
, rm
,
1060 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued
, timeo
);
1061 if (timeo
> 0 || timeo
== MAX_SCHEDULE_TIMEOUT
)
1071 * By now we've committed to the send. We reuse rds_send_worker()
1072 * to retry sends in the rds thread if the transport asks us to.
1074 rds_stats_inc(s_send_queued
);
1076 if (!test_bit(RDS_LL_SEND_FULL
, &conn
->c_flags
))
1077 rds_send_xmit(conn
);
1079 rds_message_put(rm
);
1083 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1084 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1085 * or in any other way, we need to destroy the MR again */
1087 rds_rdma_unuse(rs
, rds_rdma_cookie_key(rm
->m_rdma_cookie
), 1);
1090 rds_message_put(rm
);
1095 * Reply to a ping packet.
1098 rds_send_pong(struct rds_connection
*conn
, __be16 dport
)
1100 struct rds_message
*rm
;
1101 unsigned long flags
;
1104 rm
= rds_message_alloc(0, GFP_ATOMIC
);
1110 rm
->m_daddr
= conn
->c_faddr
;
1112 /* If the connection is down, trigger a connect. We may
1113 * have scheduled a delayed reconnect however - in this case
1114 * we should not interfere.
1116 if (rds_conn_state(conn
) == RDS_CONN_DOWN
&&
1117 !test_and_set_bit(RDS_RECONNECT_PENDING
, &conn
->c_flags
))
1118 queue_delayed_work(rds_wq
, &conn
->c_conn_w
, 0);
1120 ret
= rds_cong_wait(conn
->c_fcong
, dport
, 1, NULL
);
1124 spin_lock_irqsave(&conn
->c_lock
, flags
);
1125 list_add_tail(&rm
->m_conn_item
, &conn
->c_send_queue
);
1126 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
1127 rds_message_addref(rm
);
1128 rm
->m_inc
.i_conn
= conn
;
1130 rds_message_populate_header(&rm
->m_inc
.i_hdr
, 0, dport
,
1131 conn
->c_next_tx_seq
);
1132 conn
->c_next_tx_seq
++;
1133 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
1135 rds_stats_inc(s_send_queued
);
1136 rds_stats_inc(s_send_pong
);
1138 queue_delayed_work(rds_wq
, &conn
->c_send_w
, 0);
1139 rds_message_put(rm
);
1144 rds_message_put(rm
);