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>
40 #include <linux/export.h>
44 /* When transmitting messages in rds_send_xmit, we need to emerge from
45 * time to time and briefly release the CPU. Otherwise the softlock watchdog
47 * Also, it seems fairer to not let one busy connection stall all the
50 * send_batch_count is the number of times we'll loop in send_xmit. Setting
51 * it to 0 will restore the old behavior (where we looped until we had
54 static int send_batch_count
= 64;
55 module_param(send_batch_count
, int, 0444);
56 MODULE_PARM_DESC(send_batch_count
, " batch factor when working the send queue");
58 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
);
61 * Reset the send state. Callers must ensure that this doesn't race with
64 void rds_send_reset(struct rds_connection
*conn
)
66 struct rds_message
*rm
, *tmp
;
69 if (conn
->c_xmit_rm
) {
71 conn
->c_xmit_rm
= NULL
;
72 /* Tell the user the RDMA op is no longer mapped by the
73 * transport. This isn't entirely true (it's flushed out
74 * independently) but as the connection is down, there's
75 * no ongoing RDMA to/from that memory */
76 rds_message_unmapped(rm
);
81 conn
->c_xmit_hdr_off
= 0;
82 conn
->c_xmit_data_off
= 0;
83 conn
->c_xmit_atomic_sent
= 0;
84 conn
->c_xmit_rdma_sent
= 0;
85 conn
->c_xmit_data_sent
= 0;
87 conn
->c_map_queued
= 0;
89 conn
->c_unacked_packets
= rds_sysctl_max_unacked_packets
;
90 conn
->c_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
92 /* Mark messages as retransmissions, and move them to the send q */
93 spin_lock_irqsave(&conn
->c_lock
, flags
);
94 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
95 set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
96 set_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
);
98 list_splice_init(&conn
->c_retrans
, &conn
->c_send_queue
);
99 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
102 static int acquire_in_xmit(struct rds_connection
*conn
)
104 return test_and_set_bit(RDS_IN_XMIT
, &conn
->c_flags
) == 0;
107 static void release_in_xmit(struct rds_connection
*conn
)
109 clear_bit(RDS_IN_XMIT
, &conn
->c_flags
);
110 smp_mb__after_atomic();
112 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
113 * hot path and finding waiters is very rare. We don't want to walk
114 * the system-wide hashed waitqueue buckets in the fast path only to
115 * almost never find waiters.
117 if (waitqueue_active(&conn
->c_waitq
))
118 wake_up_all(&conn
->c_waitq
);
122 * We're making the conscious trade-off here to only send one message
123 * down the connection at a time.
125 * - tx queueing is a simple fifo list
126 * - reassembly is optional and easily done by transports per conn
127 * - no per flow rx lookup at all, straight to the socket
128 * - less per-frag memory and wire overhead
130 * - queued acks can be delayed behind large messages
132 * - small message latency is higher behind queued large messages
133 * - large message latency isn't starved by intervening small sends
135 int rds_send_xmit(struct rds_connection
*conn
)
137 struct rds_message
*rm
;
140 struct scatterlist
*sg
;
142 LIST_HEAD(to_be_dropped
);
147 * sendmsg calls here after having queued its message on the send
148 * queue. We only have one task feeding the connection at a time. If
149 * another thread is already feeding the queue then we back off. This
150 * avoids blocking the caller and trading per-connection data between
151 * caches per message.
153 if (!acquire_in_xmit(conn
)) {
154 rds_stats_inc(s_send_lock_contention
);
160 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
161 * we do the opposite to avoid races.
163 if (!rds_conn_up(conn
)) {
164 release_in_xmit(conn
);
169 if (conn
->c_trans
->xmit_prepare
)
170 conn
->c_trans
->xmit_prepare(conn
);
173 * spin trying to push headers and data down the connection until
174 * the connection doesn't make forward progress.
178 rm
= conn
->c_xmit_rm
;
181 * If between sending messages, we can send a pending congestion
184 if (!rm
&& test_and_clear_bit(0, &conn
->c_map_queued
)) {
185 rm
= rds_cong_update_alloc(conn
);
190 rm
->data
.op_active
= 1;
192 conn
->c_xmit_rm
= rm
;
196 * If not already working on one, grab the next message.
198 * c_xmit_rm holds a ref while we're sending this message down
199 * the connction. We can use this ref while holding the
200 * send_sem.. rds_send_reset() is serialized with it.
205 spin_lock_irqsave(&conn
->c_lock
, flags
);
207 if (!list_empty(&conn
->c_send_queue
)) {
208 rm
= list_entry(conn
->c_send_queue
.next
,
211 rds_message_addref(rm
);
214 * Move the message from the send queue to the retransmit
217 list_move_tail(&rm
->m_conn_item
, &conn
->c_retrans
);
220 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
225 /* Unfortunately, the way Infiniband deals with
226 * RDMA to a bad MR key is by moving the entire
227 * queue pair to error state. We cold possibly
228 * recover from that, but right now we drop the
230 * Therefore, we never retransmit messages with RDMA ops.
232 if (rm
->rdma
.op_active
&&
233 test_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
)) {
234 spin_lock_irqsave(&conn
->c_lock
, flags
);
235 if (test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
))
236 list_move(&rm
->m_conn_item
, &to_be_dropped
);
237 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
241 /* Require an ACK every once in a while */
242 len
= ntohl(rm
->m_inc
.i_hdr
.h_len
);
243 if (conn
->c_unacked_packets
== 0 ||
244 conn
->c_unacked_bytes
< len
) {
245 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
247 conn
->c_unacked_packets
= rds_sysctl_max_unacked_packets
;
248 conn
->c_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
249 rds_stats_inc(s_send_ack_required
);
251 conn
->c_unacked_bytes
-= len
;
252 conn
->c_unacked_packets
--;
255 conn
->c_xmit_rm
= rm
;
258 /* The transport either sends the whole rdma or none of it */
259 if (rm
->rdma
.op_active
&& !conn
->c_xmit_rdma_sent
) {
260 rm
->m_final_op
= &rm
->rdma
;
261 ret
= conn
->c_trans
->xmit_rdma(conn
, &rm
->rdma
);
264 conn
->c_xmit_rdma_sent
= 1;
266 /* The transport owns the mapped memory for now.
267 * You can't unmap it while it's on the send queue */
268 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
271 if (rm
->atomic
.op_active
&& !conn
->c_xmit_atomic_sent
) {
272 rm
->m_final_op
= &rm
->atomic
;
273 ret
= conn
->c_trans
->xmit_atomic(conn
, &rm
->atomic
);
276 conn
->c_xmit_atomic_sent
= 1;
278 /* The transport owns the mapped memory for now.
279 * You can't unmap it while it's on the send queue */
280 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
284 * A number of cases require an RDS header to be sent
285 * even if there is no data.
286 * We permit 0-byte sends; rds-ping depends on this.
287 * However, if there are exclusively attached silent ops,
288 * we skip the hdr/data send, to enable silent operation.
290 if (rm
->data
.op_nents
== 0) {
292 int all_ops_are_silent
= 1;
294 ops_present
= (rm
->atomic
.op_active
|| rm
->rdma
.op_active
);
295 if (rm
->atomic
.op_active
&& !rm
->atomic
.op_silent
)
296 all_ops_are_silent
= 0;
297 if (rm
->rdma
.op_active
&& !rm
->rdma
.op_silent
)
298 all_ops_are_silent
= 0;
300 if (ops_present
&& all_ops_are_silent
301 && !rm
->m_rdma_cookie
)
302 rm
->data
.op_active
= 0;
305 if (rm
->data
.op_active
&& !conn
->c_xmit_data_sent
) {
306 rm
->m_final_op
= &rm
->data
;
307 ret
= conn
->c_trans
->xmit(conn
, rm
,
308 conn
->c_xmit_hdr_off
,
310 conn
->c_xmit_data_off
);
314 if (conn
->c_xmit_hdr_off
< sizeof(struct rds_header
)) {
315 tmp
= min_t(int, ret
,
316 sizeof(struct rds_header
) -
317 conn
->c_xmit_hdr_off
);
318 conn
->c_xmit_hdr_off
+= tmp
;
322 sg
= &rm
->data
.op_sg
[conn
->c_xmit_sg
];
324 tmp
= min_t(int, ret
, sg
->length
-
325 conn
->c_xmit_data_off
);
326 conn
->c_xmit_data_off
+= tmp
;
328 if (conn
->c_xmit_data_off
== sg
->length
) {
329 conn
->c_xmit_data_off
= 0;
333 conn
->c_xmit_sg
== rm
->data
.op_nents
);
337 if (conn
->c_xmit_hdr_off
== sizeof(struct rds_header
) &&
338 (conn
->c_xmit_sg
== rm
->data
.op_nents
))
339 conn
->c_xmit_data_sent
= 1;
343 * A rm will only take multiple times through this loop
344 * if there is a data op. Thus, if the data is sent (or there was
345 * none), then we're done with the rm.
347 if (!rm
->data
.op_active
|| conn
->c_xmit_data_sent
) {
348 conn
->c_xmit_rm
= NULL
;
350 conn
->c_xmit_hdr_off
= 0;
351 conn
->c_xmit_data_off
= 0;
352 conn
->c_xmit_rdma_sent
= 0;
353 conn
->c_xmit_atomic_sent
= 0;
354 conn
->c_xmit_data_sent
= 0;
360 if (conn
->c_trans
->xmit_complete
)
361 conn
->c_trans
->xmit_complete(conn
);
363 release_in_xmit(conn
);
365 /* Nuke any messages we decided not to retransmit. */
366 if (!list_empty(&to_be_dropped
)) {
367 /* irqs on here, so we can put(), unlike above */
368 list_for_each_entry(rm
, &to_be_dropped
, m_conn_item
)
370 rds_send_remove_from_sock(&to_be_dropped
, RDS_RDMA_DROPPED
);
374 * Other senders can queue a message after we last test the send queue
375 * but before we clear RDS_IN_XMIT. In that case they'd back off and
376 * not try and send their newly queued message. We need to check the
377 * send queue after having cleared RDS_IN_XMIT so that their message
378 * doesn't get stuck on the send queue.
380 * If the transport cannot continue (i.e ret != 0), then it must
381 * call us when more room is available, such as from the tx
382 * completion handler.
386 if (!list_empty(&conn
->c_send_queue
)) {
387 rds_stats_inc(s_send_lock_queue_raced
);
395 static void rds_send_sndbuf_remove(struct rds_sock
*rs
, struct rds_message
*rm
)
397 u32 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
399 assert_spin_locked(&rs
->rs_lock
);
401 BUG_ON(rs
->rs_snd_bytes
< len
);
402 rs
->rs_snd_bytes
-= len
;
404 if (rs
->rs_snd_bytes
== 0)
405 rds_stats_inc(s_send_queue_empty
);
408 static inline int rds_send_is_acked(struct rds_message
*rm
, u64 ack
,
409 is_acked_func is_acked
)
412 return is_acked(rm
, ack
);
413 return be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) <= ack
;
417 * This is pretty similar to what happens below in the ACK
418 * handling code - except that we call here as soon as we get
419 * the IB send completion on the RDMA op and the accompanying
422 void rds_rdma_send_complete(struct rds_message
*rm
, int status
)
424 struct rds_sock
*rs
= NULL
;
425 struct rm_rdma_op
*ro
;
426 struct rds_notifier
*notifier
;
429 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
432 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
) &&
433 ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
434 notifier
= ro
->op_notifier
;
436 sock_hold(rds_rs_to_sk(rs
));
438 notifier
->n_status
= status
;
439 spin_lock(&rs
->rs_lock
);
440 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
441 spin_unlock(&rs
->rs_lock
);
443 ro
->op_notifier
= NULL
;
446 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
449 rds_wake_sk_sleep(rs
);
450 sock_put(rds_rs_to_sk(rs
));
453 EXPORT_SYMBOL_GPL(rds_rdma_send_complete
);
456 * Just like above, except looks at atomic op
458 void rds_atomic_send_complete(struct rds_message
*rm
, int status
)
460 struct rds_sock
*rs
= NULL
;
461 struct rm_atomic_op
*ao
;
462 struct rds_notifier
*notifier
;
465 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
468 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)
469 && ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
470 notifier
= ao
->op_notifier
;
472 sock_hold(rds_rs_to_sk(rs
));
474 notifier
->n_status
= status
;
475 spin_lock(&rs
->rs_lock
);
476 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
477 spin_unlock(&rs
->rs_lock
);
479 ao
->op_notifier
= NULL
;
482 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
485 rds_wake_sk_sleep(rs
);
486 sock_put(rds_rs_to_sk(rs
));
489 EXPORT_SYMBOL_GPL(rds_atomic_send_complete
);
492 * This is the same as rds_rdma_send_complete except we
493 * don't do any locking - we have all the ingredients (message,
494 * socket, socket lock) and can just move the notifier.
497 __rds_send_complete(struct rds_sock
*rs
, struct rds_message
*rm
, int status
)
499 struct rm_rdma_op
*ro
;
500 struct rm_atomic_op
*ao
;
503 if (ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
504 ro
->op_notifier
->n_status
= status
;
505 list_add_tail(&ro
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
506 ro
->op_notifier
= NULL
;
510 if (ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
511 ao
->op_notifier
->n_status
= status
;
512 list_add_tail(&ao
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
513 ao
->op_notifier
= NULL
;
516 /* No need to wake the app - caller does this */
520 * This is called from the IB send completion when we detect
521 * a RDMA operation that failed with remote access error.
522 * So speed is not an issue here.
524 struct rds_message
*rds_send_get_message(struct rds_connection
*conn
,
525 struct rm_rdma_op
*op
)
527 struct rds_message
*rm
, *tmp
, *found
= NULL
;
530 spin_lock_irqsave(&conn
->c_lock
, flags
);
532 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
533 if (&rm
->rdma
== op
) {
534 atomic_inc(&rm
->m_refcount
);
540 list_for_each_entry_safe(rm
, tmp
, &conn
->c_send_queue
, m_conn_item
) {
541 if (&rm
->rdma
== op
) {
542 atomic_inc(&rm
->m_refcount
);
549 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
553 EXPORT_SYMBOL_GPL(rds_send_get_message
);
556 * This removes messages from the socket's list if they're on it. The list
557 * argument must be private to the caller, we must be able to modify it
558 * without locks. The messages must have a reference held for their
559 * position on the list. This function will drop that reference after
560 * removing the messages from the 'messages' list regardless of if it found
561 * the messages on the socket list or not.
563 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
)
566 struct rds_sock
*rs
= NULL
;
567 struct rds_message
*rm
;
569 while (!list_empty(messages
)) {
572 rm
= list_entry(messages
->next
, struct rds_message
,
574 list_del_init(&rm
->m_conn_item
);
577 * If we see this flag cleared then we're *sure* that someone
578 * else beat us to removing it from the sock. If we race
579 * with their flag update we'll get the lock and then really
580 * see that the flag has been cleared.
582 * The message spinlock makes sure nobody clears rm->m_rs
583 * while we're messing with it. It does not prevent the
584 * message from being removed from the socket, though.
586 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
587 if (!test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
))
588 goto unlock_and_drop
;
590 if (rs
!= rm
->m_rs
) {
592 rds_wake_sk_sleep(rs
);
593 sock_put(rds_rs_to_sk(rs
));
597 sock_hold(rds_rs_to_sk(rs
));
600 goto unlock_and_drop
;
601 spin_lock(&rs
->rs_lock
);
603 if (test_and_clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)) {
604 struct rm_rdma_op
*ro
= &rm
->rdma
;
605 struct rds_notifier
*notifier
;
607 list_del_init(&rm
->m_sock_item
);
608 rds_send_sndbuf_remove(rs
, rm
);
610 if (ro
->op_active
&& ro
->op_notifier
&&
611 (ro
->op_notify
|| (ro
->op_recverr
&& status
))) {
612 notifier
= ro
->op_notifier
;
613 list_add_tail(¬ifier
->n_list
,
614 &rs
->rs_notify_queue
);
615 if (!notifier
->n_status
)
616 notifier
->n_status
= status
;
617 rm
->rdma
.op_notifier
= NULL
;
622 spin_unlock(&rs
->rs_lock
);
625 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
632 rds_wake_sk_sleep(rs
);
633 sock_put(rds_rs_to_sk(rs
));
638 * Transports call here when they've determined that the receiver queued
639 * messages up to, and including, the given sequence number. Messages are
640 * moved to the retrans queue when rds_send_xmit picks them off the send
641 * queue. This means that in the TCP case, the message may not have been
642 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
643 * checks the RDS_MSG_HAS_ACK_SEQ bit.
645 void rds_send_drop_acked(struct rds_connection
*conn
, u64 ack
,
646 is_acked_func is_acked
)
648 struct rds_message
*rm
, *tmp
;
652 spin_lock_irqsave(&conn
->c_lock
, flags
);
654 list_for_each_entry_safe(rm
, tmp
, &conn
->c_retrans
, m_conn_item
) {
655 if (!rds_send_is_acked(rm
, ack
, is_acked
))
658 list_move(&rm
->m_conn_item
, &list
);
659 clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
662 /* order flag updates with spin locks */
663 if (!list_empty(&list
))
664 smp_mb__after_atomic();
666 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
668 /* now remove the messages from the sock list as needed */
669 rds_send_remove_from_sock(&list
, RDS_RDMA_SUCCESS
);
671 EXPORT_SYMBOL_GPL(rds_send_drop_acked
);
673 void rds_send_drop_to(struct rds_sock
*rs
, struct sockaddr_in
*dest
)
675 struct rds_message
*rm
, *tmp
;
676 struct rds_connection
*conn
;
680 /* get all the messages we're dropping under the rs lock */
681 spin_lock_irqsave(&rs
->rs_lock
, flags
);
683 list_for_each_entry_safe(rm
, tmp
, &rs
->rs_send_queue
, m_sock_item
) {
684 if (dest
&& (dest
->sin_addr
.s_addr
!= rm
->m_daddr
||
685 dest
->sin_port
!= rm
->m_inc
.i_hdr
.h_dport
))
688 list_move(&rm
->m_sock_item
, &list
);
689 rds_send_sndbuf_remove(rs
, rm
);
690 clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
693 /* order flag updates with the rs lock */
694 smp_mb__after_atomic();
696 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
698 if (list_empty(&list
))
701 /* Remove the messages from the conn */
702 list_for_each_entry(rm
, &list
, m_sock_item
) {
704 conn
= rm
->m_inc
.i_conn
;
706 spin_lock_irqsave(&conn
->c_lock
, flags
);
708 * Maybe someone else beat us to removing rm from the conn.
709 * If we race with their flag update we'll get the lock and
710 * then really see that the flag has been cleared.
712 if (!test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
)) {
713 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
714 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
716 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
719 list_del_init(&rm
->m_conn_item
);
720 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
723 * Couldn't grab m_rs_lock in top loop (lock ordering),
726 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
728 spin_lock(&rs
->rs_lock
);
729 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
730 spin_unlock(&rs
->rs_lock
);
733 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
738 rds_wake_sk_sleep(rs
);
740 while (!list_empty(&list
)) {
741 rm
= list_entry(list
.next
, struct rds_message
, m_sock_item
);
742 list_del_init(&rm
->m_sock_item
);
744 rds_message_wait(rm
);
750 * we only want this to fire once so we use the callers 'queued'. It's
751 * possible that another thread can race with us and remove the
752 * message from the flow with RDS_CANCEL_SENT_TO.
754 static int rds_send_queue_rm(struct rds_sock
*rs
, struct rds_connection
*conn
,
755 struct rds_message
*rm
, __be16 sport
,
756 __be16 dport
, int *queued
)
764 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
766 /* this is the only place which holds both the socket's rs_lock
767 * and the connection's c_lock */
768 spin_lock_irqsave(&rs
->rs_lock
, flags
);
771 * If there is a little space in sndbuf, we don't queue anything,
772 * and userspace gets -EAGAIN. But poll() indicates there's send
773 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
774 * freed up by incoming acks. So we check the *old* value of
775 * rs_snd_bytes here to allow the last msg to exceed the buffer,
776 * and poll() now knows no more data can be sent.
778 if (rs
->rs_snd_bytes
< rds_sk_sndbuf(rs
)) {
779 rs
->rs_snd_bytes
+= len
;
781 /* let recv side know we are close to send space exhaustion.
782 * This is probably not the optimal way to do it, as this
783 * means we set the flag on *all* messages as soon as our
784 * throughput hits a certain threshold.
786 if (rs
->rs_snd_bytes
>= rds_sk_sndbuf(rs
) / 2)
787 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
789 list_add_tail(&rm
->m_sock_item
, &rs
->rs_send_queue
);
790 set_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
791 rds_message_addref(rm
);
794 /* The code ordering is a little weird, but we're
795 trying to minimize the time we hold c_lock */
796 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
, 0);
797 rm
->m_inc
.i_conn
= conn
;
798 rds_message_addref(rm
);
800 spin_lock(&conn
->c_lock
);
801 rm
->m_inc
.i_hdr
.h_sequence
= cpu_to_be64(conn
->c_next_tx_seq
++);
802 list_add_tail(&rm
->m_conn_item
, &conn
->c_send_queue
);
803 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
804 spin_unlock(&conn
->c_lock
);
806 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
807 rm
, len
, rs
, rs
->rs_snd_bytes
,
808 (unsigned long long)be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
));
813 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
819 * rds_message is getting to be quite complicated, and we'd like to allocate
820 * it all in one go. This figures out how big it needs to be up front.
822 static int rds_rm_size(struct msghdr
*msg
, int data_len
)
824 struct cmsghdr
*cmsg
;
829 for_each_cmsghdr(cmsg
, msg
) {
830 if (!CMSG_OK(msg
, cmsg
))
833 if (cmsg
->cmsg_level
!= SOL_RDS
)
836 switch (cmsg
->cmsg_type
) {
837 case RDS_CMSG_RDMA_ARGS
:
839 retval
= rds_rdma_extra_size(CMSG_DATA(cmsg
));
846 case RDS_CMSG_RDMA_DEST
:
847 case RDS_CMSG_RDMA_MAP
:
849 /* these are valid but do no add any size */
852 case RDS_CMSG_ATOMIC_CSWP
:
853 case RDS_CMSG_ATOMIC_FADD
:
854 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
855 case RDS_CMSG_MASKED_ATOMIC_FADD
:
857 size
+= sizeof(struct scatterlist
);
866 size
+= ceil(data_len
, PAGE_SIZE
) * sizeof(struct scatterlist
);
868 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
869 if (cmsg_groups
== 3)
875 static int rds_cmsg_send(struct rds_sock
*rs
, struct rds_message
*rm
,
876 struct msghdr
*msg
, int *allocated_mr
)
878 struct cmsghdr
*cmsg
;
881 for_each_cmsghdr(cmsg
, msg
) {
882 if (!CMSG_OK(msg
, cmsg
))
885 if (cmsg
->cmsg_level
!= SOL_RDS
)
888 /* As a side effect, RDMA_DEST and RDMA_MAP will set
889 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
891 switch (cmsg
->cmsg_type
) {
892 case RDS_CMSG_RDMA_ARGS
:
893 ret
= rds_cmsg_rdma_args(rs
, rm
, cmsg
);
896 case RDS_CMSG_RDMA_DEST
:
897 ret
= rds_cmsg_rdma_dest(rs
, rm
, cmsg
);
900 case RDS_CMSG_RDMA_MAP
:
901 ret
= rds_cmsg_rdma_map(rs
, rm
, cmsg
);
905 case RDS_CMSG_ATOMIC_CSWP
:
906 case RDS_CMSG_ATOMIC_FADD
:
907 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
908 case RDS_CMSG_MASKED_ATOMIC_FADD
:
909 ret
= rds_cmsg_atomic(rs
, rm
, cmsg
);
923 int rds_sendmsg(struct kiocb
*iocb
, struct socket
*sock
, struct msghdr
*msg
,
926 struct sock
*sk
= sock
->sk
;
927 struct rds_sock
*rs
= rds_sk_to_rs(sk
);
928 DECLARE_SOCKADDR(struct sockaddr_in
*, usin
, msg
->msg_name
);
931 struct rds_message
*rm
= NULL
;
932 struct rds_connection
*conn
;
934 int queued
= 0, allocated_mr
= 0;
935 int nonblock
= msg
->msg_flags
& MSG_DONTWAIT
;
936 long timeo
= sock_sndtimeo(sk
, nonblock
);
938 /* Mirror Linux UDP mirror of BSD error message compatibility */
939 /* XXX: Perhaps MSG_MORE someday */
940 if (msg
->msg_flags
& ~(MSG_DONTWAIT
| MSG_CMSG_COMPAT
)) {
945 if (msg
->msg_namelen
) {
946 /* XXX fail non-unicast destination IPs? */
947 if (msg
->msg_namelen
< sizeof(*usin
) || usin
->sin_family
!= AF_INET
) {
951 daddr
= usin
->sin_addr
.s_addr
;
952 dport
= usin
->sin_port
;
954 /* We only care about consistency with ->connect() */
956 daddr
= rs
->rs_conn_addr
;
957 dport
= rs
->rs_conn_port
;
961 /* racing with another thread binding seems ok here */
962 if (daddr
== 0 || rs
->rs_bound_addr
== 0) {
963 ret
= -ENOTCONN
; /* XXX not a great errno */
967 /* size of rm including all sgs */
968 ret
= rds_rm_size(msg
, payload_len
);
972 rm
= rds_message_alloc(ret
, GFP_KERNEL
);
978 /* Attach data to the rm */
980 rm
->data
.op_sg
= rds_message_alloc_sgs(rm
, ceil(payload_len
, PAGE_SIZE
));
981 if (!rm
->data
.op_sg
) {
985 ret
= rds_message_copy_from_user(rm
, &msg
->msg_iter
);
989 rm
->data
.op_active
= 1;
993 /* rds_conn_create has a spinlock that runs with IRQ off.
994 * Caching the conn in the socket helps a lot. */
995 if (rs
->rs_conn
&& rs
->rs_conn
->c_faddr
== daddr
)
998 conn
= rds_conn_create_outgoing(rs
->rs_bound_addr
, daddr
,
1000 sock
->sk
->sk_allocation
);
1002 ret
= PTR_ERR(conn
);
1008 /* Parse any control messages the user may have included. */
1009 ret
= rds_cmsg_send(rs
, rm
, msg
, &allocated_mr
);
1013 if (rm
->rdma
.op_active
&& !conn
->c_trans
->xmit_rdma
) {
1014 printk_ratelimited(KERN_NOTICE
"rdma_op %p conn xmit_rdma %p\n",
1015 &rm
->rdma
, conn
->c_trans
->xmit_rdma
);
1020 if (rm
->atomic
.op_active
&& !conn
->c_trans
->xmit_atomic
) {
1021 printk_ratelimited(KERN_NOTICE
"atomic_op %p conn xmit_atomic %p\n",
1022 &rm
->atomic
, conn
->c_trans
->xmit_atomic
);
1027 rds_conn_connect_if_down(conn
);
1029 ret
= rds_cong_wait(conn
->c_fcong
, dport
, nonblock
, rs
);
1031 rs
->rs_seen_congestion
= 1;
1035 while (!rds_send_queue_rm(rs
, conn
, rm
, rs
->rs_bound_port
,
1037 rds_stats_inc(s_send_queue_full
);
1038 /* XXX make sure this is reasonable */
1039 if (payload_len
> rds_sk_sndbuf(rs
)) {
1048 timeo
= wait_event_interruptible_timeout(*sk_sleep(sk
),
1049 rds_send_queue_rm(rs
, conn
, rm
,
1054 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued
, timeo
);
1055 if (timeo
> 0 || timeo
== MAX_SCHEDULE_TIMEOUT
)
1065 * By now we've committed to the send. We reuse rds_send_worker()
1066 * to retry sends in the rds thread if the transport asks us to.
1068 rds_stats_inc(s_send_queued
);
1070 if (!test_bit(RDS_LL_SEND_FULL
, &conn
->c_flags
))
1071 rds_send_xmit(conn
);
1073 rds_message_put(rm
);
1077 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1078 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1079 * or in any other way, we need to destroy the MR again */
1081 rds_rdma_unuse(rs
, rds_rdma_cookie_key(rm
->m_rdma_cookie
), 1);
1084 rds_message_put(rm
);
1089 * Reply to a ping packet.
1092 rds_send_pong(struct rds_connection
*conn
, __be16 dport
)
1094 struct rds_message
*rm
;
1095 unsigned long flags
;
1098 rm
= rds_message_alloc(0, GFP_ATOMIC
);
1104 rm
->m_daddr
= conn
->c_faddr
;
1105 rm
->data
.op_active
= 1;
1107 rds_conn_connect_if_down(conn
);
1109 ret
= rds_cong_wait(conn
->c_fcong
, dport
, 1, NULL
);
1113 spin_lock_irqsave(&conn
->c_lock
, flags
);
1114 list_add_tail(&rm
->m_conn_item
, &conn
->c_send_queue
);
1115 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
1116 rds_message_addref(rm
);
1117 rm
->m_inc
.i_conn
= conn
;
1119 rds_message_populate_header(&rm
->m_inc
.i_hdr
, 0, dport
,
1120 conn
->c_next_tx_seq
);
1121 conn
->c_next_tx_seq
++;
1122 spin_unlock_irqrestore(&conn
->c_lock
, flags
);
1124 rds_stats_inc(s_send_queued
);
1125 rds_stats_inc(s_send_pong
);
1127 if (!test_bit(RDS_LL_SEND_FULL
, &conn
->c_flags
))
1128 queue_delayed_work(rds_wq
, &conn
->c_send_w
, 0);
1130 rds_message_put(rm
);
1135 rds_message_put(rm
);