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/moduleparam.h>
35 #include <linux/gfp.h>
38 #include <linux/list.h>
39 #include <linux/ratelimit.h>
43 /* When transmitting messages in rds_send_xmit, we need to emerge from
44 * time to time and briefly release the CPU. Otherwise the softlock watchdog
46 * Also, it seems fairer to not let one busy connection stall all the
49 * send_batch_count is the number of times we'll loop in send_xmit. Setting
50 * it to 0 will restore the old behavior (where we looped until we had
53 static int send_batch_count
= 64;
54 module_param(send_batch_count
, int, 0444);
55 MODULE_PARM_DESC(send_batch_count
, " batch factor when working the send queue");
57 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
);
60 * Reset the send state. Callers must ensure that this doesn't race with
63 void rds_send_reset(struct rds_connection
*conn
)
65 struct rds_message
*rm
, *tmp
;
68 if (conn
->c_xmit_rm
) {
70 conn
->c_xmit_rm
= NULL
;
71 /* Tell the user the RDMA op is no longer mapped by the
72 * transport. This isn't entirely true (it's flushed out
73 * independently) but as the connection is down, there's
74 * no ongoing RDMA to/from that memory */
75 rds_message_unmapped(rm
);
80 conn
->c_xmit_hdr_off
= 0;
81 conn
->c_xmit_data_off
= 0;
82 conn
->c_xmit_atomic_sent
= 0;
83 conn
->c_xmit_rdma_sent
= 0;
84 conn
->c_xmit_data_sent
= 0;
86 conn
->c_map_queued
= 0;
88 conn
->c_unacked_packets
= rds_sysctl_max_unacked_packets
;
89 conn
->c_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
91 /* Mark messages as retransmissions, and move them to the send q */
92 spin_lock_irqsave(&conn
->c_lock
, flags
);
93 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
94 set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
95 set_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
);
97 list_splice_init(&conn
->c_retrans
, &conn
->c_send_queue
);
98 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
101 static int acquire_in_xmit(struct rds_connection
*conn
)
103 return test_and_set_bit(RDS_IN_XMIT
, &conn
->c_flags
) == 0;
106 static void release_in_xmit(struct rds_connection
*conn
)
108 clear_bit(RDS_IN_XMIT
, &conn
->c_flags
);
109 smp_mb__after_clear_bit();
111 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
112 * hot path and finding waiters is very rare. We don't want to walk
113 * the system-wide hashed waitqueue buckets in the fast path only to
114 * almost never find waiters.
116 if (waitqueue_active(&conn
->c_waitq
))
117 wake_up_all(&conn
->c_waitq
);
121 * We're making the conscious trade-off here to only send one message
122 * down the connection at a time.
124 * - tx queueing is a simple fifo list
125 * - reassembly is optional and easily done by transports per conn
126 * - no per flow rx lookup at all, straight to the socket
127 * - less per-frag memory and wire overhead
129 * - queued acks can be delayed behind large messages
131 * - small message latency is higher behind queued large messages
132 * - large message latency isn't starved by intervening small sends
134 int rds_send_xmit(struct rds_connection
*conn
)
136 struct rds_message
*rm
;
139 struct scatterlist
*sg
;
141 LIST_HEAD(to_be_dropped
);
146 * sendmsg calls here after having queued its message on the send
147 * queue. We only have one task feeding the connection at a time. If
148 * another thread is already feeding the queue then we back off. This
149 * avoids blocking the caller and trading per-connection data between
150 * caches per message.
152 if (!acquire_in_xmit(conn
)) {
153 rds_stats_inc(s_send_lock_contention
);
159 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
160 * we do the opposite to avoid races.
162 if (!rds_conn_up(conn
)) {
163 release_in_xmit(conn
);
168 if (conn
->c_trans
->xmit_prepare
)
169 conn
->c_trans
->xmit_prepare(conn
);
172 * spin trying to push headers and data down the connection until
173 * the connection doesn't make forward progress.
177 rm
= conn
->c_xmit_rm
;
180 * If between sending messages, we can send a pending congestion
183 if (!rm
&& test_and_clear_bit(0, &conn
->c_map_queued
)) {
184 rm
= rds_cong_update_alloc(conn
);
189 rm
->data
.op_active
= 1;
191 conn
->c_xmit_rm
= rm
;
195 * If not already working on one, grab the next message.
197 * c_xmit_rm holds a ref while we're sending this message down
198 * the connction. We can use this ref while holding the
199 * send_sem.. rds_send_reset() is serialized with it.
204 spin_lock_irqsave(&conn
->c_lock
, flags
);
206 if (!list_empty(&conn
->c_send_queue
)) {
207 rm
= list_entry(conn
->c_send_queue
.next
,
210 rds_message_addref(rm
);
213 * Move the message from the send queue to the retransmit
216 list_move_tail(&rm
->m_conn_item
, &conn
->c_retrans
);
219 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
224 /* Unfortunately, the way Infiniband deals with
225 * RDMA to a bad MR key is by moving the entire
226 * queue pair to error state. We cold possibly
227 * recover from that, but right now we drop the
229 * Therefore, we never retransmit messages with RDMA ops.
231 if (rm
->rdma
.op_active
&&
232 test_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
)) {
233 spin_lock_irqsave(&conn
->c_lock
, flags
);
234 if (test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
))
235 list_move(&rm
->m_conn_item
, &to_be_dropped
);
236 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
240 /* Require an ACK every once in a while */
241 len
= ntohl(rm
->m_inc
.i_hdr
.h_len
);
242 if (conn
->c_unacked_packets
== 0 ||
243 conn
->c_unacked_bytes
< len
) {
244 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
246 conn
->c_unacked_packets
= rds_sysctl_max_unacked_packets
;
247 conn
->c_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
248 rds_stats_inc(s_send_ack_required
);
250 conn
->c_unacked_bytes
-= len
;
251 conn
->c_unacked_packets
--;
254 conn
->c_xmit_rm
= rm
;
257 /* The transport either sends the whole rdma or none of it */
258 if (rm
->rdma
.op_active
&& !conn
->c_xmit_rdma_sent
) {
259 rm
->m_final_op
= &rm
->rdma
;
260 ret
= conn
->c_trans
->xmit_rdma(conn
, &rm
->rdma
);
263 conn
->c_xmit_rdma_sent
= 1;
265 /* The transport owns the mapped memory for now.
266 * You can't unmap it while it's on the send queue */
267 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
270 if (rm
->atomic
.op_active
&& !conn
->c_xmit_atomic_sent
) {
271 rm
->m_final_op
= &rm
->atomic
;
272 ret
= conn
->c_trans
->xmit_atomic(conn
, &rm
->atomic
);
275 conn
->c_xmit_atomic_sent
= 1;
277 /* The transport owns the mapped memory for now.
278 * You can't unmap it while it's on the send queue */
279 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
283 * A number of cases require an RDS header to be sent
284 * even if there is no data.
285 * We permit 0-byte sends; rds-ping depends on this.
286 * However, if there are exclusively attached silent ops,
287 * we skip the hdr/data send, to enable silent operation.
289 if (rm
->data
.op_nents
== 0) {
291 int all_ops_are_silent
= 1;
293 ops_present
= (rm
->atomic
.op_active
|| rm
->rdma
.op_active
);
294 if (rm
->atomic
.op_active
&& !rm
->atomic
.op_silent
)
295 all_ops_are_silent
= 0;
296 if (rm
->rdma
.op_active
&& !rm
->rdma
.op_silent
)
297 all_ops_are_silent
= 0;
299 if (ops_present
&& all_ops_are_silent
300 && !rm
->m_rdma_cookie
)
301 rm
->data
.op_active
= 0;
304 if (rm
->data
.op_active
&& !conn
->c_xmit_data_sent
) {
305 rm
->m_final_op
= &rm
->data
;
306 ret
= conn
->c_trans
->xmit(conn
, rm
,
307 conn
->c_xmit_hdr_off
,
309 conn
->c_xmit_data_off
);
313 if (conn
->c_xmit_hdr_off
< sizeof(struct rds_header
)) {
314 tmp
= min_t(int, ret
,
315 sizeof(struct rds_header
) -
316 conn
->c_xmit_hdr_off
);
317 conn
->c_xmit_hdr_off
+= tmp
;
321 sg
= &rm
->data
.op_sg
[conn
->c_xmit_sg
];
323 tmp
= min_t(int, ret
, sg
->length
-
324 conn
->c_xmit_data_off
);
325 conn
->c_xmit_data_off
+= tmp
;
327 if (conn
->c_xmit_data_off
== sg
->length
) {
328 conn
->c_xmit_data_off
= 0;
332 conn
->c_xmit_sg
== rm
->data
.op_nents
);
336 if (conn
->c_xmit_hdr_off
== sizeof(struct rds_header
) &&
337 (conn
->c_xmit_sg
== rm
->data
.op_nents
))
338 conn
->c_xmit_data_sent
= 1;
342 * A rm will only take multiple times through this loop
343 * if there is a data op. Thus, if the data is sent (or there was
344 * none), then we're done with the rm.
346 if (!rm
->data
.op_active
|| conn
->c_xmit_data_sent
) {
347 conn
->c_xmit_rm
= NULL
;
349 conn
->c_xmit_hdr_off
= 0;
350 conn
->c_xmit_data_off
= 0;
351 conn
->c_xmit_rdma_sent
= 0;
352 conn
->c_xmit_atomic_sent
= 0;
353 conn
->c_xmit_data_sent
= 0;
359 if (conn
->c_trans
->xmit_complete
)
360 conn
->c_trans
->xmit_complete(conn
);
362 release_in_xmit(conn
);
364 /* Nuke any messages we decided not to retransmit. */
365 if (!list_empty(&to_be_dropped
)) {
366 /* irqs on here, so we can put(), unlike above */
367 list_for_each_entry(rm
, &to_be_dropped
, m_conn_item
)
369 rds_send_remove_from_sock(&to_be_dropped
, RDS_RDMA_DROPPED
);
373 * Other senders can queue a message after we last test the send queue
374 * but before we clear RDS_IN_XMIT. In that case they'd back off and
375 * not try and send their newly queued message. We need to check the
376 * send queue after having cleared RDS_IN_XMIT so that their message
377 * doesn't get stuck on the send queue.
379 * If the transport cannot continue (i.e ret != 0), then it must
380 * call us when more room is available, such as from the tx
381 * completion handler.
385 if (!list_empty(&conn
->c_send_queue
)) {
386 rds_stats_inc(s_send_lock_queue_raced
);
394 static void rds_send_sndbuf_remove(struct rds_sock
*rs
, struct rds_message
*rm
)
396 u32 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
398 assert_spin_locked(&rs
->rs_lock
);
400 BUG_ON(rs
->rs_snd_bytes
< len
);
401 rs
->rs_snd_bytes
-= len
;
403 if (rs
->rs_snd_bytes
== 0)
404 rds_stats_inc(s_send_queue_empty
);
407 static inline int rds_send_is_acked(struct rds_message
*rm
, u64 ack
,
408 is_acked_func is_acked
)
411 return is_acked(rm
, ack
);
412 return be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) <= ack
;
416 * This is pretty similar to what happens below in the ACK
417 * handling code - except that we call here as soon as we get
418 * the IB send completion on the RDMA op and the accompanying
421 void rds_rdma_send_complete(struct rds_message
*rm
, int status
)
423 struct rds_sock
*rs
= NULL
;
424 struct rm_rdma_op
*ro
;
425 struct rds_notifier
*notifier
;
428 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
431 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
) &&
432 ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
433 notifier
= ro
->op_notifier
;
435 sock_hold(rds_rs_to_sk(rs
));
437 notifier
->n_status
= status
;
438 spin_lock(&rs
->rs_lock
);
439 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
440 spin_unlock(&rs
->rs_lock
);
442 ro
->op_notifier
= NULL
;
445 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
448 rds_wake_sk_sleep(rs
);
449 sock_put(rds_rs_to_sk(rs
));
452 EXPORT_SYMBOL_GPL(rds_rdma_send_complete
);
455 * Just like above, except looks at atomic op
457 void rds_atomic_send_complete(struct rds_message
*rm
, int status
)
459 struct rds_sock
*rs
= NULL
;
460 struct rm_atomic_op
*ao
;
461 struct rds_notifier
*notifier
;
464 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
467 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)
468 && ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
469 notifier
= ao
->op_notifier
;
471 sock_hold(rds_rs_to_sk(rs
));
473 notifier
->n_status
= status
;
474 spin_lock(&rs
->rs_lock
);
475 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
476 spin_unlock(&rs
->rs_lock
);
478 ao
->op_notifier
= NULL
;
481 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
484 rds_wake_sk_sleep(rs
);
485 sock_put(rds_rs_to_sk(rs
));
488 EXPORT_SYMBOL_GPL(rds_atomic_send_complete
);
491 * This is the same as rds_rdma_send_complete except we
492 * don't do any locking - we have all the ingredients (message,
493 * socket, socket lock) and can just move the notifier.
496 __rds_send_complete(struct rds_sock
*rs
, struct rds_message
*rm
, int status
)
498 struct rm_rdma_op
*ro
;
499 struct rm_atomic_op
*ao
;
502 if (ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
503 ro
->op_notifier
->n_status
= status
;
504 list_add_tail(&ro
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
505 ro
->op_notifier
= NULL
;
509 if (ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
510 ao
->op_notifier
->n_status
= status
;
511 list_add_tail(&ao
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
512 ao
->op_notifier
= NULL
;
515 /* No need to wake the app - caller does this */
519 * This is called from the IB send completion when we detect
520 * a RDMA operation that failed with remote access error.
521 * So speed is not an issue here.
523 struct rds_message
*rds_send_get_message(struct rds_connection
*conn
,
524 struct rm_rdma_op
*op
)
526 struct rds_message
*rm
, *tmp
, *found
= NULL
;
529 spin_lock_irqsave(&conn
->c_lock
, flags
);
531 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
532 if (&rm
->rdma
== op
) {
533 atomic_inc(&rm
->m_refcount
);
539 list_for_each_entry_safe(rm
, tmp
, &conn
->c_send_queue
, m_conn_item
) {
540 if (&rm
->rdma
== op
) {
541 atomic_inc(&rm
->m_refcount
);
548 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
552 EXPORT_SYMBOL_GPL(rds_send_get_message
);
555 * This removes messages from the socket's list if they're on it. The list
556 * argument must be private to the caller, we must be able to modify it
557 * without locks. The messages must have a reference held for their
558 * position on the list. This function will drop that reference after
559 * removing the messages from the 'messages' list regardless of if it found
560 * the messages on the socket list or not.
562 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
)
565 struct rds_sock
*rs
= NULL
;
566 struct rds_message
*rm
;
568 while (!list_empty(messages
)) {
571 rm
= list_entry(messages
->next
, struct rds_message
,
573 list_del_init(&rm
->m_conn_item
);
576 * If we see this flag cleared then we're *sure* that someone
577 * else beat us to removing it from the sock. If we race
578 * with their flag update we'll get the lock and then really
579 * see that the flag has been cleared.
581 * The message spinlock makes sure nobody clears rm->m_rs
582 * while we're messing with it. It does not prevent the
583 * message from being removed from the socket, though.
585 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
586 if (!test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
))
587 goto unlock_and_drop
;
589 if (rs
!= rm
->m_rs
) {
591 rds_wake_sk_sleep(rs
);
592 sock_put(rds_rs_to_sk(rs
));
595 sock_hold(rds_rs_to_sk(rs
));
597 spin_lock(&rs
->rs_lock
);
599 if (test_and_clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)) {
600 struct rm_rdma_op
*ro
= &rm
->rdma
;
601 struct rds_notifier
*notifier
;
603 list_del_init(&rm
->m_sock_item
);
604 rds_send_sndbuf_remove(rs
, rm
);
606 if (ro
->op_active
&& ro
->op_notifier
&&
607 (ro
->op_notify
|| (ro
->op_recverr
&& status
))) {
608 notifier
= ro
->op_notifier
;
609 list_add_tail(¬ifier
->n_list
,
610 &rs
->rs_notify_queue
);
611 if (!notifier
->n_status
)
612 notifier
->n_status
= status
;
613 rm
->rdma
.op_notifier
= NULL
;
618 spin_unlock(&rs
->rs_lock
);
621 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
628 rds_wake_sk_sleep(rs
);
629 sock_put(rds_rs_to_sk(rs
));
634 * Transports call here when they've determined that the receiver queued
635 * messages up to, and including, the given sequence number. Messages are
636 * moved to the retrans queue when rds_send_xmit picks them off the send
637 * queue. This means that in the TCP case, the message may not have been
638 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
639 * checks the RDS_MSG_HAS_ACK_SEQ bit.
641 * XXX It's not clear to me how this is safely serialized with socket
642 * destruction. Maybe it should bail if it sees SOCK_DEAD.
644 void rds_send_drop_acked(struct rds_connection
*conn
, u64 ack
,
645 is_acked_func is_acked
)
647 struct rds_message
*rm
, *tmp
;
651 spin_lock_irqsave(&conn
->c_lock
, flags
);
653 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
654 if (!rds_send_is_acked(rm
, ack
, is_acked
))
657 list_move(&rm
->m_conn_item
, &list
);
658 clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
661 /* order flag updates with spin locks */
662 if (!list_empty(&list
))
663 smp_mb__after_clear_bit();
665 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
667 /* now remove the messages from the sock list as needed */
668 rds_send_remove_from_sock(&list
, RDS_RDMA_SUCCESS
);
670 EXPORT_SYMBOL_GPL(rds_send_drop_acked
);
672 void rds_send_drop_to(struct rds_sock
*rs
, struct sockaddr_in
*dest
)
674 struct rds_message
*rm
, *tmp
;
675 struct rds_connection
*conn
;
679 /* get all the messages we're dropping under the rs lock */
680 spin_lock_irqsave(&rs
->rs_lock
, flags
);
682 list_for_each_entry_safe(rm
, tmp
, &rs
->rs_send_queue
, m_sock_item
) {
683 if (dest
&& (dest
->sin_addr
.s_addr
!= rm
->m_daddr
||
684 dest
->sin_port
!= rm
->m_inc
.i_hdr
.h_dport
))
687 list_move(&rm
->m_sock_item
, &list
);
688 rds_send_sndbuf_remove(rs
, rm
);
689 clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
692 /* order flag updates with the rs lock */
693 smp_mb__after_clear_bit();
695 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
697 if (list_empty(&list
))
700 /* Remove the messages from the conn */
701 list_for_each_entry(rm
, &list
, m_sock_item
) {
703 conn
= rm
->m_inc
.i_conn
;
705 spin_lock_irqsave(&conn
->c_lock
, flags
);
707 * Maybe someone else beat us to removing rm from the conn.
708 * If we race with their flag update we'll get the lock and
709 * then really see that the flag has been cleared.
711 if (!test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
)) {
712 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
715 list_del_init(&rm
->m_conn_item
);
716 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
719 * Couldn't grab m_rs_lock in top loop (lock ordering),
722 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
724 spin_lock(&rs
->rs_lock
);
725 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
726 spin_unlock(&rs
->rs_lock
);
729 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
734 rds_wake_sk_sleep(rs
);
736 while (!list_empty(&list
)) {
737 rm
= list_entry(list
.next
, struct rds_message
, m_sock_item
);
738 list_del_init(&rm
->m_sock_item
);
740 rds_message_wait(rm
);
746 * we only want this to fire once so we use the callers 'queued'. It's
747 * possible that another thread can race with us and remove the
748 * message from the flow with RDS_CANCEL_SENT_TO.
750 static int rds_send_queue_rm(struct rds_sock
*rs
, struct rds_connection
*conn
,
751 struct rds_message
*rm
, __be16 sport
,
752 __be16 dport
, int *queued
)
760 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
762 /* this is the only place which holds both the socket's rs_lock
763 * and the connection's c_lock */
764 spin_lock_irqsave(&rs
->rs_lock
, flags
);
767 * If there is a little space in sndbuf, we don't queue anything,
768 * and userspace gets -EAGAIN. But poll() indicates there's send
769 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
770 * freed up by incoming acks. So we check the *old* value of
771 * rs_snd_bytes here to allow the last msg to exceed the buffer,
772 * and poll() now knows no more data can be sent.
774 if (rs
->rs_snd_bytes
< rds_sk_sndbuf(rs
)) {
775 rs
->rs_snd_bytes
+= len
;
777 /* let recv side know we are close to send space exhaustion.
778 * This is probably not the optimal way to do it, as this
779 * means we set the flag on *all* messages as soon as our
780 * throughput hits a certain threshold.
782 if (rs
->rs_snd_bytes
>= rds_sk_sndbuf(rs
) / 2)
783 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
785 list_add_tail(&rm
->m_sock_item
, &rs
->rs_send_queue
);
786 set_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
787 rds_message_addref(rm
);
790 /* The code ordering is a little weird, but we're
791 trying to minimize the time we hold c_lock */
792 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
, 0);
793 rm
->m_inc
.i_conn
= conn
;
794 rds_message_addref(rm
);
796 spin_lock(&conn
->c_lock
);
797 rm
->m_inc
.i_hdr
.h_sequence
= cpu_to_be64(conn
->c_next_tx_seq
++);
798 list_add_tail(&rm
->m_conn_item
, &conn
->c_send_queue
);
799 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
800 spin_unlock(&conn
->c_lock
);
802 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
803 rm
, len
, rs
, rs
->rs_snd_bytes
,
804 (unsigned long long)be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
));
809 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
815 * rds_message is getting to be quite complicated, and we'd like to allocate
816 * it all in one go. This figures out how big it needs to be up front.
818 static int rds_rm_size(struct msghdr
*msg
, int data_len
)
820 struct cmsghdr
*cmsg
;
825 for (cmsg
= CMSG_FIRSTHDR(msg
); cmsg
; cmsg
= CMSG_NXTHDR(msg
, cmsg
)) {
826 if (!CMSG_OK(msg
, cmsg
))
829 if (cmsg
->cmsg_level
!= SOL_RDS
)
832 switch (cmsg
->cmsg_type
) {
833 case RDS_CMSG_RDMA_ARGS
:
835 retval
= rds_rdma_extra_size(CMSG_DATA(cmsg
));
842 case RDS_CMSG_RDMA_DEST
:
843 case RDS_CMSG_RDMA_MAP
:
845 /* these are valid but do no add any size */
848 case RDS_CMSG_ATOMIC_CSWP
:
849 case RDS_CMSG_ATOMIC_FADD
:
850 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
851 case RDS_CMSG_MASKED_ATOMIC_FADD
:
853 size
+= sizeof(struct scatterlist
);
862 size
+= ceil(data_len
, PAGE_SIZE
) * sizeof(struct scatterlist
);
864 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
865 if (cmsg_groups
== 3)
871 static int rds_cmsg_send(struct rds_sock
*rs
, struct rds_message
*rm
,
872 struct msghdr
*msg
, int *allocated_mr
)
874 struct cmsghdr
*cmsg
;
877 for (cmsg
= CMSG_FIRSTHDR(msg
); cmsg
; cmsg
= CMSG_NXTHDR(msg
, cmsg
)) {
878 if (!CMSG_OK(msg
, cmsg
))
881 if (cmsg
->cmsg_level
!= SOL_RDS
)
884 /* As a side effect, RDMA_DEST and RDMA_MAP will set
885 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
887 switch (cmsg
->cmsg_type
) {
888 case RDS_CMSG_RDMA_ARGS
:
889 ret
= rds_cmsg_rdma_args(rs
, rm
, cmsg
);
892 case RDS_CMSG_RDMA_DEST
:
893 ret
= rds_cmsg_rdma_dest(rs
, rm
, cmsg
);
896 case RDS_CMSG_RDMA_MAP
:
897 ret
= rds_cmsg_rdma_map(rs
, rm
, cmsg
);
901 case RDS_CMSG_ATOMIC_CSWP
:
902 case RDS_CMSG_ATOMIC_FADD
:
903 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
904 case RDS_CMSG_MASKED_ATOMIC_FADD
:
905 ret
= rds_cmsg_atomic(rs
, rm
, cmsg
);
919 int rds_sendmsg(struct kiocb
*iocb
, struct socket
*sock
, struct msghdr
*msg
,
922 struct sock
*sk
= sock
->sk
;
923 struct rds_sock
*rs
= rds_sk_to_rs(sk
);
924 struct sockaddr_in
*usin
= (struct sockaddr_in
*)msg
->msg_name
;
927 struct rds_message
*rm
= NULL
;
928 struct rds_connection
*conn
;
930 int queued
= 0, allocated_mr
= 0;
931 int nonblock
= msg
->msg_flags
& MSG_DONTWAIT
;
932 long timeo
= sock_sndtimeo(sk
, nonblock
);
934 /* Mirror Linux UDP mirror of BSD error message compatibility */
935 /* XXX: Perhaps MSG_MORE someday */
936 if (msg
->msg_flags
& ~(MSG_DONTWAIT
| MSG_CMSG_COMPAT
)) {
937 printk(KERN_INFO
"msg_flags 0x%08X\n", msg
->msg_flags
);
942 if (msg
->msg_namelen
) {
943 /* XXX fail non-unicast destination IPs? */
944 if (msg
->msg_namelen
< sizeof(*usin
) || usin
->sin_family
!= AF_INET
) {
948 daddr
= usin
->sin_addr
.s_addr
;
949 dport
= usin
->sin_port
;
951 /* We only care about consistency with ->connect() */
953 daddr
= rs
->rs_conn_addr
;
954 dport
= rs
->rs_conn_port
;
958 /* racing with another thread binding seems ok here */
959 if (daddr
== 0 || rs
->rs_bound_addr
== 0) {
960 ret
= -ENOTCONN
; /* XXX not a great errno */
964 /* size of rm including all sgs */
965 ret
= rds_rm_size(msg
, payload_len
);
969 rm
= rds_message_alloc(ret
, GFP_KERNEL
);
975 /* Attach data to the rm */
977 rm
->data
.op_sg
= rds_message_alloc_sgs(rm
, ceil(payload_len
, PAGE_SIZE
));
978 if (!rm
->data
.op_sg
) {
982 ret
= rds_message_copy_from_user(rm
, msg
->msg_iov
, payload_len
);
986 rm
->data
.op_active
= 1;
990 /* rds_conn_create has a spinlock that runs with IRQ off.
991 * Caching the conn in the socket helps a lot. */
992 if (rs
->rs_conn
&& rs
->rs_conn
->c_faddr
== daddr
)
995 conn
= rds_conn_create_outgoing(rs
->rs_bound_addr
, daddr
,
997 sock
->sk
->sk_allocation
);
1005 /* Parse any control messages the user may have included. */
1006 ret
= rds_cmsg_send(rs
, rm
, msg
, &allocated_mr
);
1010 if (rm
->rdma
.op_active
&& !conn
->c_trans
->xmit_rdma
) {
1011 printk_ratelimited(KERN_NOTICE
"rdma_op %p conn xmit_rdma %p\n",
1012 &rm
->rdma
, conn
->c_trans
->xmit_rdma
);
1017 if (rm
->atomic
.op_active
&& !conn
->c_trans
->xmit_atomic
) {
1018 printk_ratelimited(KERN_NOTICE
"atomic_op %p conn xmit_atomic %p\n",
1019 &rm
->atomic
, conn
->c_trans
->xmit_atomic
);
1024 rds_conn_connect_if_down(conn
);
1026 ret
= rds_cong_wait(conn
->c_fcong
, dport
, nonblock
, rs
);
1028 rs
->rs_seen_congestion
= 1;
1032 while (!rds_send_queue_rm(rs
, conn
, rm
, rs
->rs_bound_port
,
1034 rds_stats_inc(s_send_queue_full
);
1035 /* XXX make sure this is reasonable */
1036 if (payload_len
> rds_sk_sndbuf(rs
)) {
1045 timeo
= wait_event_interruptible_timeout(*sk_sleep(sk
),
1046 rds_send_queue_rm(rs
, conn
, rm
,
1051 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued
, timeo
);
1052 if (timeo
> 0 || timeo
== MAX_SCHEDULE_TIMEOUT
)
1062 * By now we've committed to the send. We reuse rds_send_worker()
1063 * to retry sends in the rds thread if the transport asks us to.
1065 rds_stats_inc(s_send_queued
);
1067 if (!test_bit(RDS_LL_SEND_FULL
, &conn
->c_flags
))
1068 rds_send_xmit(conn
);
1070 rds_message_put(rm
);
1074 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1075 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1076 * or in any other way, we need to destroy the MR again */
1078 rds_rdma_unuse(rs
, rds_rdma_cookie_key(rm
->m_rdma_cookie
), 1);
1081 rds_message_put(rm
);
1086 * Reply to a ping packet.
1089 rds_send_pong(struct rds_connection
*conn
, __be16 dport
)
1091 struct rds_message
*rm
;
1092 unsigned long flags
;
1095 rm
= rds_message_alloc(0, GFP_ATOMIC
);
1101 rm
->m_daddr
= conn
->c_faddr
;
1102 rm
->data
.op_active
= 1;
1104 rds_conn_connect_if_down(conn
);
1106 ret
= rds_cong_wait(conn
->c_fcong
, dport
, 1, NULL
);
1110 spin_lock_irqsave(&conn
->c_lock
, flags
);
1111 list_add_tail(&rm
->m_conn_item
, &conn
->c_send_queue
);
1112 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
1113 rds_message_addref(rm
);
1114 rm
->m_inc
.i_conn
= conn
;
1116 rds_message_populate_header(&rm
->m_inc
.i_hdr
, 0, dport
,
1117 conn
->c_next_tx_seq
);
1118 conn
->c_next_tx_seq
++;
1119 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
1121 rds_stats_inc(s_send_queued
);
1122 rds_stats_inc(s_send_pong
);
1124 if (!test_bit(RDS_LL_SEND_FULL
, &conn
->c_flags
))
1125 rds_send_xmit(conn
);
1127 rds_message_put(rm
);
1132 rds_message_put(rm
);