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>
41 #include <linux/sizes.h>
45 /* When transmitting messages in rds_send_xmit, we need to emerge from
46 * time to time and briefly release the CPU. Otherwise the softlock watchdog
48 * Also, it seems fairer to not let one busy connection stall all the
51 * send_batch_count is the number of times we'll loop in send_xmit. Setting
52 * it to 0 will restore the old behavior (where we looped until we had
55 static int send_batch_count
= SZ_1K
;
56 module_param(send_batch_count
, int, 0444);
57 MODULE_PARM_DESC(send_batch_count
, " batch factor when working the send queue");
59 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
);
62 * Reset the send state. Callers must ensure that this doesn't race with
65 void rds_send_path_reset(struct rds_conn_path
*cp
)
67 struct rds_message
*rm
, *tmp
;
72 cp
->cp_xmit_rm
= NULL
;
73 /* Tell the user the RDMA op is no longer mapped by the
74 * transport. This isn't entirely true (it's flushed out
75 * independently) but as the connection is down, there's
76 * no ongoing RDMA to/from that memory */
77 rds_message_unmapped(rm
);
82 cp
->cp_xmit_hdr_off
= 0;
83 cp
->cp_xmit_data_off
= 0;
84 cp
->cp_xmit_atomic_sent
= 0;
85 cp
->cp_xmit_rdma_sent
= 0;
86 cp
->cp_xmit_data_sent
= 0;
88 cp
->cp_conn
->c_map_queued
= 0;
90 cp
->cp_unacked_packets
= rds_sysctl_max_unacked_packets
;
91 cp
->cp_unacked_bytes
= rds_sysctl_max_unacked_bytes
;
93 /* Mark messages as retransmissions, and move them to the send q */
94 spin_lock_irqsave(&cp
->cp_lock
, flags
);
95 list_for_each_entry_safe(rm
, tmp
, &cp
->cp_retrans
, m_conn_item
) {
96 set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
97 set_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
);
99 list_splice_init(&cp
->cp_retrans
, &cp
->cp_send_queue
);
100 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
102 EXPORT_SYMBOL_GPL(rds_send_path_reset
);
104 static int acquire_in_xmit(struct rds_conn_path
*cp
)
106 return test_and_set_bit(RDS_IN_XMIT
, &cp
->cp_flags
) == 0;
109 static void release_in_xmit(struct rds_conn_path
*cp
)
111 clear_bit(RDS_IN_XMIT
, &cp
->cp_flags
);
112 smp_mb__after_atomic();
114 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
115 * hot path and finding waiters is very rare. We don't want to walk
116 * the system-wide hashed waitqueue buckets in the fast path only to
117 * almost never find waiters.
119 if (waitqueue_active(&cp
->cp_waitq
))
120 wake_up_all(&cp
->cp_waitq
);
124 * We're making the conscious trade-off here to only send one message
125 * down the connection at a time.
127 * - tx queueing is a simple fifo list
128 * - reassembly is optional and easily done by transports per conn
129 * - no per flow rx lookup at all, straight to the socket
130 * - less per-frag memory and wire overhead
132 * - queued acks can be delayed behind large messages
134 * - small message latency is higher behind queued large messages
135 * - large message latency isn't starved by intervening small sends
137 int rds_send_xmit(struct rds_conn_path
*cp
)
139 struct rds_connection
*conn
= cp
->cp_conn
;
140 struct rds_message
*rm
;
143 struct scatterlist
*sg
;
145 LIST_HEAD(to_be_dropped
);
147 unsigned long send_gen
= 0;
153 * sendmsg calls here after having queued its message on the send
154 * queue. We only have one task feeding the connection at a time. If
155 * another thread is already feeding the queue then we back off. This
156 * avoids blocking the caller and trading per-connection data between
157 * caches per message.
159 if (!acquire_in_xmit(cp
)) {
160 rds_stats_inc(s_send_lock_contention
);
166 * we record the send generation after doing the xmit acquire.
167 * if someone else manages to jump in and do some work, we'll use
168 * this to avoid a goto restart farther down.
170 * The acquire_in_xmit() check above ensures that only one
171 * caller can increment c_send_gen at any time.
174 send_gen
= cp
->cp_send_gen
;
177 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
178 * we do the opposite to avoid races.
180 if (!rds_conn_path_up(cp
)) {
186 if (conn
->c_trans
->xmit_path_prepare
)
187 conn
->c_trans
->xmit_path_prepare(cp
);
190 * spin trying to push headers and data down the connection until
191 * the connection doesn't make forward progress.
198 * If between sending messages, we can send a pending congestion
201 if (!rm
&& test_and_clear_bit(0, &conn
->c_map_queued
)) {
202 rm
= rds_cong_update_alloc(conn
);
207 rm
->data
.op_active
= 1;
208 rm
->m_inc
.i_conn_path
= cp
;
209 rm
->m_inc
.i_conn
= cp
->cp_conn
;
215 * If not already working on one, grab the next message.
217 * cp_xmit_rm holds a ref while we're sending this message down
218 * the connction. We can use this ref while holding the
219 * send_sem.. rds_send_reset() is serialized with it.
226 /* we want to process as big a batch as we can, but
227 * we also want to avoid softlockups. If we've been
228 * through a lot of messages, lets back off and see
229 * if anyone else jumps in
231 if (batch_count
>= send_batch_count
)
234 spin_lock_irqsave(&cp
->cp_lock
, flags
);
236 if (!list_empty(&cp
->cp_send_queue
)) {
237 rm
= list_entry(cp
->cp_send_queue
.next
,
240 rds_message_addref(rm
);
243 * Move the message from the send queue to the retransmit
246 list_move_tail(&rm
->m_conn_item
,
250 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
255 /* Unfortunately, the way Infiniband deals with
256 * RDMA to a bad MR key is by moving the entire
257 * queue pair to error state. We cold possibly
258 * recover from that, but right now we drop the
260 * Therefore, we never retransmit messages with RDMA ops.
262 if (test_bit(RDS_MSG_FLUSH
, &rm
->m_flags
) ||
263 (rm
->rdma
.op_active
&&
264 test_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
))) {
265 spin_lock_irqsave(&cp
->cp_lock
, flags
);
266 if (test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
))
267 list_move(&rm
->m_conn_item
, &to_be_dropped
);
268 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
272 /* Require an ACK every once in a while */
273 len
= ntohl(rm
->m_inc
.i_hdr
.h_len
);
274 if (cp
->cp_unacked_packets
== 0 ||
275 cp
->cp_unacked_bytes
< len
) {
276 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
278 cp
->cp_unacked_packets
=
279 rds_sysctl_max_unacked_packets
;
280 cp
->cp_unacked_bytes
=
281 rds_sysctl_max_unacked_bytes
;
282 rds_stats_inc(s_send_ack_required
);
284 cp
->cp_unacked_bytes
-= len
;
285 cp
->cp_unacked_packets
--;
291 /* The transport either sends the whole rdma or none of it */
292 if (rm
->rdma
.op_active
&& !cp
->cp_xmit_rdma_sent
) {
293 rm
->m_final_op
= &rm
->rdma
;
294 /* The transport owns the mapped memory for now.
295 * You can't unmap it while it's on the send queue
297 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
298 ret
= conn
->c_trans
->xmit_rdma(conn
, &rm
->rdma
);
300 clear_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
301 wake_up_interruptible(&rm
->m_flush_wait
);
304 cp
->cp_xmit_rdma_sent
= 1;
308 if (rm
->atomic
.op_active
&& !cp
->cp_xmit_atomic_sent
) {
309 rm
->m_final_op
= &rm
->atomic
;
310 /* The transport owns the mapped memory for now.
311 * You can't unmap it while it's on the send queue
313 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
314 ret
= conn
->c_trans
->xmit_atomic(conn
, &rm
->atomic
);
316 clear_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
317 wake_up_interruptible(&rm
->m_flush_wait
);
320 cp
->cp_xmit_atomic_sent
= 1;
325 * A number of cases require an RDS header to be sent
326 * even if there is no data.
327 * We permit 0-byte sends; rds-ping depends on this.
328 * However, if there are exclusively attached silent ops,
329 * we skip the hdr/data send, to enable silent operation.
331 if (rm
->data
.op_nents
== 0) {
333 int all_ops_are_silent
= 1;
335 ops_present
= (rm
->atomic
.op_active
|| rm
->rdma
.op_active
);
336 if (rm
->atomic
.op_active
&& !rm
->atomic
.op_silent
)
337 all_ops_are_silent
= 0;
338 if (rm
->rdma
.op_active
&& !rm
->rdma
.op_silent
)
339 all_ops_are_silent
= 0;
341 if (ops_present
&& all_ops_are_silent
342 && !rm
->m_rdma_cookie
)
343 rm
->data
.op_active
= 0;
346 if (rm
->data
.op_active
&& !cp
->cp_xmit_data_sent
) {
347 rm
->m_final_op
= &rm
->data
;
349 ret
= conn
->c_trans
->xmit(conn
, rm
,
352 cp
->cp_xmit_data_off
);
356 if (cp
->cp_xmit_hdr_off
< sizeof(struct rds_header
)) {
357 tmp
= min_t(int, ret
,
358 sizeof(struct rds_header
) -
359 cp
->cp_xmit_hdr_off
);
360 cp
->cp_xmit_hdr_off
+= tmp
;
364 sg
= &rm
->data
.op_sg
[cp
->cp_xmit_sg
];
366 tmp
= min_t(int, ret
, sg
->length
-
367 cp
->cp_xmit_data_off
);
368 cp
->cp_xmit_data_off
+= tmp
;
370 if (cp
->cp_xmit_data_off
== sg
->length
) {
371 cp
->cp_xmit_data_off
= 0;
374 BUG_ON(ret
!= 0 && cp
->cp_xmit_sg
==
379 if (cp
->cp_xmit_hdr_off
== sizeof(struct rds_header
) &&
380 (cp
->cp_xmit_sg
== rm
->data
.op_nents
))
381 cp
->cp_xmit_data_sent
= 1;
385 * A rm will only take multiple times through this loop
386 * if there is a data op. Thus, if the data is sent (or there was
387 * none), then we're done with the rm.
389 if (!rm
->data
.op_active
|| cp
->cp_xmit_data_sent
) {
390 cp
->cp_xmit_rm
= NULL
;
392 cp
->cp_xmit_hdr_off
= 0;
393 cp
->cp_xmit_data_off
= 0;
394 cp
->cp_xmit_rdma_sent
= 0;
395 cp
->cp_xmit_atomic_sent
= 0;
396 cp
->cp_xmit_data_sent
= 0;
403 if (conn
->c_trans
->xmit_path_complete
)
404 conn
->c_trans
->xmit_path_complete(cp
);
407 /* Nuke any messages we decided not to retransmit. */
408 if (!list_empty(&to_be_dropped
)) {
409 /* irqs on here, so we can put(), unlike above */
410 list_for_each_entry(rm
, &to_be_dropped
, m_conn_item
)
412 rds_send_remove_from_sock(&to_be_dropped
, RDS_RDMA_DROPPED
);
416 * Other senders can queue a message after we last test the send queue
417 * but before we clear RDS_IN_XMIT. In that case they'd back off and
418 * not try and send their newly queued message. We need to check the
419 * send queue after having cleared RDS_IN_XMIT so that their message
420 * doesn't get stuck on the send queue.
422 * If the transport cannot continue (i.e ret != 0), then it must
423 * call us when more room is available, such as from the tx
424 * completion handler.
426 * We have an extra generation check here so that if someone manages
427 * to jump in after our release_in_xmit, we'll see that they have done
428 * some work and we will skip our goto
432 if ((test_bit(0, &conn
->c_map_queued
) ||
433 !list_empty(&cp
->cp_send_queue
)) &&
434 send_gen
== cp
->cp_send_gen
) {
435 rds_stats_inc(s_send_lock_queue_raced
);
436 if (batch_count
< send_batch_count
)
438 queue_delayed_work(rds_wq
, &cp
->cp_send_w
, 1);
444 EXPORT_SYMBOL_GPL(rds_send_xmit
);
446 static void rds_send_sndbuf_remove(struct rds_sock
*rs
, struct rds_message
*rm
)
448 u32 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
450 assert_spin_locked(&rs
->rs_lock
);
452 BUG_ON(rs
->rs_snd_bytes
< len
);
453 rs
->rs_snd_bytes
-= len
;
455 if (rs
->rs_snd_bytes
== 0)
456 rds_stats_inc(s_send_queue_empty
);
459 static inline int rds_send_is_acked(struct rds_message
*rm
, u64 ack
,
460 is_acked_func is_acked
)
463 return is_acked(rm
, ack
);
464 return be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) <= ack
;
468 * This is pretty similar to what happens below in the ACK
469 * handling code - except that we call here as soon as we get
470 * the IB send completion on the RDMA op and the accompanying
473 void rds_rdma_send_complete(struct rds_message
*rm
, int status
)
475 struct rds_sock
*rs
= NULL
;
476 struct rm_rdma_op
*ro
;
477 struct rds_notifier
*notifier
;
480 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
483 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
) &&
484 ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
485 notifier
= ro
->op_notifier
;
487 sock_hold(rds_rs_to_sk(rs
));
489 notifier
->n_status
= status
;
490 spin_lock(&rs
->rs_lock
);
491 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
492 spin_unlock(&rs
->rs_lock
);
494 ro
->op_notifier
= NULL
;
497 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
500 rds_wake_sk_sleep(rs
);
501 sock_put(rds_rs_to_sk(rs
));
504 EXPORT_SYMBOL_GPL(rds_rdma_send_complete
);
507 * Just like above, except looks at atomic op
509 void rds_atomic_send_complete(struct rds_message
*rm
, int status
)
511 struct rds_sock
*rs
= NULL
;
512 struct rm_atomic_op
*ao
;
513 struct rds_notifier
*notifier
;
516 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
519 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)
520 && ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
521 notifier
= ao
->op_notifier
;
523 sock_hold(rds_rs_to_sk(rs
));
525 notifier
->n_status
= status
;
526 spin_lock(&rs
->rs_lock
);
527 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
528 spin_unlock(&rs
->rs_lock
);
530 ao
->op_notifier
= NULL
;
533 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
536 rds_wake_sk_sleep(rs
);
537 sock_put(rds_rs_to_sk(rs
));
540 EXPORT_SYMBOL_GPL(rds_atomic_send_complete
);
543 * This is the same as rds_rdma_send_complete except we
544 * don't do any locking - we have all the ingredients (message,
545 * socket, socket lock) and can just move the notifier.
548 __rds_send_complete(struct rds_sock
*rs
, struct rds_message
*rm
, int status
)
550 struct rm_rdma_op
*ro
;
551 struct rm_atomic_op
*ao
;
554 if (ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
555 ro
->op_notifier
->n_status
= status
;
556 list_add_tail(&ro
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
557 ro
->op_notifier
= NULL
;
561 if (ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
562 ao
->op_notifier
->n_status
= status
;
563 list_add_tail(&ao
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
564 ao
->op_notifier
= NULL
;
567 /* No need to wake the app - caller does this */
571 * This removes messages from the socket's list if they're on it. The list
572 * argument must be private to the caller, we must be able to modify it
573 * without locks. The messages must have a reference held for their
574 * position on the list. This function will drop that reference after
575 * removing the messages from the 'messages' list regardless of if it found
576 * the messages on the socket list or not.
578 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
)
581 struct rds_sock
*rs
= NULL
;
582 struct rds_message
*rm
;
584 while (!list_empty(messages
)) {
587 rm
= list_entry(messages
->next
, struct rds_message
,
589 list_del_init(&rm
->m_conn_item
);
592 * If we see this flag cleared then we're *sure* that someone
593 * else beat us to removing it from the sock. If we race
594 * with their flag update we'll get the lock and then really
595 * see that the flag has been cleared.
597 * The message spinlock makes sure nobody clears rm->m_rs
598 * while we're messing with it. It does not prevent the
599 * message from being removed from the socket, though.
601 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
602 if (!test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
))
603 goto unlock_and_drop
;
605 if (rs
!= rm
->m_rs
) {
607 rds_wake_sk_sleep(rs
);
608 sock_put(rds_rs_to_sk(rs
));
612 sock_hold(rds_rs_to_sk(rs
));
615 goto unlock_and_drop
;
616 spin_lock(&rs
->rs_lock
);
618 if (test_and_clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)) {
619 struct rm_rdma_op
*ro
= &rm
->rdma
;
620 struct rds_notifier
*notifier
;
622 list_del_init(&rm
->m_sock_item
);
623 rds_send_sndbuf_remove(rs
, rm
);
625 if (ro
->op_active
&& ro
->op_notifier
&&
626 (ro
->op_notify
|| (ro
->op_recverr
&& status
))) {
627 notifier
= ro
->op_notifier
;
628 list_add_tail(¬ifier
->n_list
,
629 &rs
->rs_notify_queue
);
630 if (!notifier
->n_status
)
631 notifier
->n_status
= status
;
632 rm
->rdma
.op_notifier
= NULL
;
637 spin_unlock(&rs
->rs_lock
);
640 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
647 rds_wake_sk_sleep(rs
);
648 sock_put(rds_rs_to_sk(rs
));
653 * Transports call here when they've determined that the receiver queued
654 * messages up to, and including, the given sequence number. Messages are
655 * moved to the retrans queue when rds_send_xmit picks them off the send
656 * queue. This means that in the TCP case, the message may not have been
657 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
658 * checks the RDS_MSG_HAS_ACK_SEQ bit.
660 void rds_send_path_drop_acked(struct rds_conn_path
*cp
, u64 ack
,
661 is_acked_func is_acked
)
663 struct rds_message
*rm
, *tmp
;
667 spin_lock_irqsave(&cp
->cp_lock
, flags
);
669 list_for_each_entry_safe(rm
, tmp
, &cp
->cp_retrans
, m_conn_item
) {
670 if (!rds_send_is_acked(rm
, ack
, is_acked
))
673 list_move(&rm
->m_conn_item
, &list
);
674 clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
677 /* order flag updates with spin locks */
678 if (!list_empty(&list
))
679 smp_mb__after_atomic();
681 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
683 /* now remove the messages from the sock list as needed */
684 rds_send_remove_from_sock(&list
, RDS_RDMA_SUCCESS
);
686 EXPORT_SYMBOL_GPL(rds_send_path_drop_acked
);
688 void rds_send_drop_acked(struct rds_connection
*conn
, u64 ack
,
689 is_acked_func is_acked
)
691 WARN_ON(conn
->c_trans
->t_mp_capable
);
692 rds_send_path_drop_acked(&conn
->c_path
[0], ack
, is_acked
);
694 EXPORT_SYMBOL_GPL(rds_send_drop_acked
);
696 void rds_send_drop_to(struct rds_sock
*rs
, struct sockaddr_in
*dest
)
698 struct rds_message
*rm
, *tmp
;
699 struct rds_connection
*conn
;
700 struct rds_conn_path
*cp
;
704 /* get all the messages we're dropping under the rs lock */
705 spin_lock_irqsave(&rs
->rs_lock
, flags
);
707 list_for_each_entry_safe(rm
, tmp
, &rs
->rs_send_queue
, m_sock_item
) {
708 if (dest
&& (dest
->sin_addr
.s_addr
!= rm
->m_daddr
||
709 dest
->sin_port
!= rm
->m_inc
.i_hdr
.h_dport
))
712 list_move(&rm
->m_sock_item
, &list
);
713 rds_send_sndbuf_remove(rs
, rm
);
714 clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
717 /* order flag updates with the rs lock */
718 smp_mb__after_atomic();
720 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
722 if (list_empty(&list
))
725 /* Remove the messages from the conn */
726 list_for_each_entry(rm
, &list
, m_sock_item
) {
728 conn
= rm
->m_inc
.i_conn
;
729 if (conn
->c_trans
->t_mp_capable
)
730 cp
= rm
->m_inc
.i_conn_path
;
732 cp
= &conn
->c_path
[0];
734 spin_lock_irqsave(&cp
->cp_lock
, flags
);
736 * Maybe someone else beat us to removing rm from the conn.
737 * If we race with their flag update we'll get the lock and
738 * then really see that the flag has been cleared.
740 if (!test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
)) {
741 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
742 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
744 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
747 list_del_init(&rm
->m_conn_item
);
748 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
751 * Couldn't grab m_rs_lock in top loop (lock ordering),
754 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
756 spin_lock(&rs
->rs_lock
);
757 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
758 spin_unlock(&rs
->rs_lock
);
761 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
766 rds_wake_sk_sleep(rs
);
768 while (!list_empty(&list
)) {
769 rm
= list_entry(list
.next
, struct rds_message
, m_sock_item
);
770 list_del_init(&rm
->m_sock_item
);
771 rds_message_wait(rm
);
773 /* just in case the code above skipped this message
774 * because RDS_MSG_ON_CONN wasn't set, run it again here
775 * taking m_rs_lock is the only thing that keeps us
776 * from racing with ack processing.
778 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
780 spin_lock(&rs
->rs_lock
);
781 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
782 spin_unlock(&rs
->rs_lock
);
785 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
792 * we only want this to fire once so we use the callers 'queued'. It's
793 * possible that another thread can race with us and remove the
794 * message from the flow with RDS_CANCEL_SENT_TO.
796 static int rds_send_queue_rm(struct rds_sock
*rs
, struct rds_connection
*conn
,
797 struct rds_conn_path
*cp
,
798 struct rds_message
*rm
, __be16 sport
,
799 __be16 dport
, int *queued
)
807 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
809 /* this is the only place which holds both the socket's rs_lock
810 * and the connection's c_lock */
811 spin_lock_irqsave(&rs
->rs_lock
, flags
);
814 * If there is a little space in sndbuf, we don't queue anything,
815 * and userspace gets -EAGAIN. But poll() indicates there's send
816 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
817 * freed up by incoming acks. So we check the *old* value of
818 * rs_snd_bytes here to allow the last msg to exceed the buffer,
819 * and poll() now knows no more data can be sent.
821 if (rs
->rs_snd_bytes
< rds_sk_sndbuf(rs
)) {
822 rs
->rs_snd_bytes
+= len
;
824 /* let recv side know we are close to send space exhaustion.
825 * This is probably not the optimal way to do it, as this
826 * means we set the flag on *all* messages as soon as our
827 * throughput hits a certain threshold.
829 if (rs
->rs_snd_bytes
>= rds_sk_sndbuf(rs
) / 2)
830 __set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
832 list_add_tail(&rm
->m_sock_item
, &rs
->rs_send_queue
);
833 set_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
834 rds_message_addref(rm
);
837 /* The code ordering is a little weird, but we're
838 trying to minimize the time we hold c_lock */
839 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
, 0);
840 rm
->m_inc
.i_conn
= conn
;
841 rm
->m_inc
.i_conn_path
= cp
;
842 rds_message_addref(rm
);
844 spin_lock(&cp
->cp_lock
);
845 rm
->m_inc
.i_hdr
.h_sequence
= cpu_to_be64(cp
->cp_next_tx_seq
++);
846 list_add_tail(&rm
->m_conn_item
, &cp
->cp_send_queue
);
847 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
848 spin_unlock(&cp
->cp_lock
);
850 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
851 rm
, len
, rs
, rs
->rs_snd_bytes
,
852 (unsigned long long)be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
));
857 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
863 * rds_message is getting to be quite complicated, and we'd like to allocate
864 * it all in one go. This figures out how big it needs to be up front.
866 static int rds_rm_size(struct msghdr
*msg
, int data_len
)
868 struct cmsghdr
*cmsg
;
873 for_each_cmsghdr(cmsg
, msg
) {
874 if (!CMSG_OK(msg
, cmsg
))
877 if (cmsg
->cmsg_level
!= SOL_RDS
)
880 switch (cmsg
->cmsg_type
) {
881 case RDS_CMSG_RDMA_ARGS
:
883 retval
= rds_rdma_extra_size(CMSG_DATA(cmsg
));
890 case RDS_CMSG_RDMA_DEST
:
891 case RDS_CMSG_RDMA_MAP
:
893 /* these are valid but do no add any size */
896 case RDS_CMSG_ATOMIC_CSWP
:
897 case RDS_CMSG_ATOMIC_FADD
:
898 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
899 case RDS_CMSG_MASKED_ATOMIC_FADD
:
901 size
+= sizeof(struct scatterlist
);
910 size
+= ceil(data_len
, PAGE_SIZE
) * sizeof(struct scatterlist
);
912 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
913 if (cmsg_groups
== 3)
919 static int rds_cmsg_send(struct rds_sock
*rs
, struct rds_message
*rm
,
920 struct msghdr
*msg
, int *allocated_mr
)
922 struct cmsghdr
*cmsg
;
925 for_each_cmsghdr(cmsg
, msg
) {
926 if (!CMSG_OK(msg
, cmsg
))
929 if (cmsg
->cmsg_level
!= SOL_RDS
)
932 /* As a side effect, RDMA_DEST and RDMA_MAP will set
933 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
935 switch (cmsg
->cmsg_type
) {
936 case RDS_CMSG_RDMA_ARGS
:
937 ret
= rds_cmsg_rdma_args(rs
, rm
, cmsg
);
940 case RDS_CMSG_RDMA_DEST
:
941 ret
= rds_cmsg_rdma_dest(rs
, rm
, cmsg
);
944 case RDS_CMSG_RDMA_MAP
:
945 ret
= rds_cmsg_rdma_map(rs
, rm
, cmsg
);
949 case RDS_CMSG_ATOMIC_CSWP
:
950 case RDS_CMSG_ATOMIC_FADD
:
951 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
952 case RDS_CMSG_MASKED_ATOMIC_FADD
:
953 ret
= rds_cmsg_atomic(rs
, rm
, cmsg
);
967 static void rds_send_ping(struct rds_connection
*conn
);
969 static int rds_send_mprds_hash(struct rds_sock
*rs
, struct rds_connection
*conn
)
973 if (conn
->c_npaths
== 0)
974 hash
= RDS_MPATH_HASH(rs
, RDS_MPATH_WORKERS
);
976 hash
= RDS_MPATH_HASH(rs
, conn
->c_npaths
);
977 if (conn
->c_npaths
== 0 && hash
!= 0) {
980 if (conn
->c_npaths
== 0) {
981 wait_event_interruptible(conn
->c_hs_waitq
,
982 (conn
->c_npaths
!= 0));
984 if (conn
->c_npaths
== 1)
990 int rds_sendmsg(struct socket
*sock
, struct msghdr
*msg
, size_t payload_len
)
992 struct sock
*sk
= sock
->sk
;
993 struct rds_sock
*rs
= rds_sk_to_rs(sk
);
994 DECLARE_SOCKADDR(struct sockaddr_in
*, usin
, msg
->msg_name
);
997 struct rds_message
*rm
= NULL
;
998 struct rds_connection
*conn
;
1000 int queued
= 0, allocated_mr
= 0;
1001 int nonblock
= msg
->msg_flags
& MSG_DONTWAIT
;
1002 long timeo
= sock_sndtimeo(sk
, nonblock
);
1003 struct rds_conn_path
*cpath
;
1005 /* Mirror Linux UDP mirror of BSD error message compatibility */
1006 /* XXX: Perhaps MSG_MORE someday */
1007 if (msg
->msg_flags
& ~(MSG_DONTWAIT
| MSG_CMSG_COMPAT
)) {
1012 if (msg
->msg_namelen
) {
1013 /* XXX fail non-unicast destination IPs? */
1014 if (msg
->msg_namelen
< sizeof(*usin
) || usin
->sin_family
!= AF_INET
) {
1018 daddr
= usin
->sin_addr
.s_addr
;
1019 dport
= usin
->sin_port
;
1021 /* We only care about consistency with ->connect() */
1023 daddr
= rs
->rs_conn_addr
;
1024 dport
= rs
->rs_conn_port
;
1029 if (daddr
== 0 || rs
->rs_bound_addr
== 0) {
1031 ret
= -ENOTCONN
; /* XXX not a great errno */
1036 if (payload_len
> rds_sk_sndbuf(rs
)) {
1041 /* size of rm including all sgs */
1042 ret
= rds_rm_size(msg
, payload_len
);
1046 rm
= rds_message_alloc(ret
, GFP_KERNEL
);
1052 /* Attach data to the rm */
1054 rm
->data
.op_sg
= rds_message_alloc_sgs(rm
, ceil(payload_len
, PAGE_SIZE
));
1055 if (!rm
->data
.op_sg
) {
1059 ret
= rds_message_copy_from_user(rm
, &msg
->msg_iter
);
1063 rm
->data
.op_active
= 1;
1065 rm
->m_daddr
= daddr
;
1067 /* rds_conn_create has a spinlock that runs with IRQ off.
1068 * Caching the conn in the socket helps a lot. */
1069 if (rs
->rs_conn
&& rs
->rs_conn
->c_faddr
== daddr
)
1072 conn
= rds_conn_create_outgoing(sock_net(sock
->sk
),
1073 rs
->rs_bound_addr
, daddr
,
1075 sock
->sk
->sk_allocation
);
1077 ret
= PTR_ERR(conn
);
1083 /* Parse any control messages the user may have included. */
1084 ret
= rds_cmsg_send(rs
, rm
, msg
, &allocated_mr
);
1088 if (rm
->rdma
.op_active
&& !conn
->c_trans
->xmit_rdma
) {
1089 printk_ratelimited(KERN_NOTICE
"rdma_op %p conn xmit_rdma %p\n",
1090 &rm
->rdma
, conn
->c_trans
->xmit_rdma
);
1095 if (rm
->atomic
.op_active
&& !conn
->c_trans
->xmit_atomic
) {
1096 printk_ratelimited(KERN_NOTICE
"atomic_op %p conn xmit_atomic %p\n",
1097 &rm
->atomic
, conn
->c_trans
->xmit_atomic
);
1102 if (conn
->c_trans
->t_mp_capable
)
1103 cpath
= &conn
->c_path
[rds_send_mprds_hash(rs
, conn
)];
1105 cpath
= &conn
->c_path
[0];
1107 rds_conn_path_connect_if_down(cpath
);
1109 ret
= rds_cong_wait(conn
->c_fcong
, dport
, nonblock
, rs
);
1111 rs
->rs_seen_congestion
= 1;
1114 while (!rds_send_queue_rm(rs
, conn
, cpath
, rm
, rs
->rs_bound_port
,
1116 rds_stats_inc(s_send_queue_full
);
1123 timeo
= wait_event_interruptible_timeout(*sk_sleep(sk
),
1124 rds_send_queue_rm(rs
, conn
, cpath
, rm
,
1129 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued
, timeo
);
1130 if (timeo
> 0 || timeo
== MAX_SCHEDULE_TIMEOUT
)
1140 * By now we've committed to the send. We reuse rds_send_worker()
1141 * to retry sends in the rds thread if the transport asks us to.
1143 rds_stats_inc(s_send_queued
);
1145 ret
= rds_send_xmit(cpath
);
1146 if (ret
== -ENOMEM
|| ret
== -EAGAIN
)
1147 queue_delayed_work(rds_wq
, &cpath
->cp_send_w
, 1);
1149 rds_message_put(rm
);
1153 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1154 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1155 * or in any other way, we need to destroy the MR again */
1157 rds_rdma_unuse(rs
, rds_rdma_cookie_key(rm
->m_rdma_cookie
), 1);
1160 rds_message_put(rm
);
1165 * send out a probe. Can be shared by rds_send_ping,
1166 * rds_send_pong, rds_send_hb.
1167 * rds_send_hb should use h_flags
1168 * RDS_FLAG_HB_PING|RDS_FLAG_ACK_REQUIRED
1170 * RDS_FLAG_HB_PONG|RDS_FLAG_ACK_REQUIRED
1173 rds_send_probe(struct rds_conn_path
*cp
, __be16 sport
,
1174 __be16 dport
, u8 h_flags
)
1176 struct rds_message
*rm
;
1177 unsigned long flags
;
1180 rm
= rds_message_alloc(0, GFP_ATOMIC
);
1186 rm
->m_daddr
= cp
->cp_conn
->c_faddr
;
1187 rm
->data
.op_active
= 1;
1189 rds_conn_path_connect_if_down(cp
);
1191 ret
= rds_cong_wait(cp
->cp_conn
->c_fcong
, dport
, 1, NULL
);
1195 spin_lock_irqsave(&cp
->cp_lock
, flags
);
1196 list_add_tail(&rm
->m_conn_item
, &cp
->cp_send_queue
);
1197 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
1198 rds_message_addref(rm
);
1199 rm
->m_inc
.i_conn
= cp
->cp_conn
;
1200 rm
->m_inc
.i_conn_path
= cp
;
1202 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
,
1203 cp
->cp_next_tx_seq
);
1204 rm
->m_inc
.i_hdr
.h_flags
|= h_flags
;
1205 cp
->cp_next_tx_seq
++;
1207 if (RDS_HS_PROBE(sport
, dport
) && cp
->cp_conn
->c_trans
->t_mp_capable
) {
1208 u16 npaths
= RDS_MPATH_WORKERS
;
1210 rds_message_add_extension(&rm
->m_inc
.i_hdr
,
1211 RDS_EXTHDR_NPATHS
, &npaths
,
1213 rds_message_add_extension(&rm
->m_inc
.i_hdr
,
1215 &cp
->cp_conn
->c_my_gen_num
,
1218 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
1220 rds_stats_inc(s_send_queued
);
1221 rds_stats_inc(s_send_pong
);
1223 /* schedule the send work on rds_wq */
1224 queue_delayed_work(rds_wq
, &cp
->cp_send_w
, 1);
1226 rds_message_put(rm
);
1231 rds_message_put(rm
);
1236 rds_send_pong(struct rds_conn_path
*cp
, __be16 dport
)
1238 return rds_send_probe(cp
, 0, dport
, 0);
1242 rds_send_ping(struct rds_connection
*conn
)
1244 unsigned long flags
;
1245 struct rds_conn_path
*cp
= &conn
->c_path
[0];
1247 spin_lock_irqsave(&cp
->cp_lock
, flags
);
1248 if (conn
->c_ping_triggered
) {
1249 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
1252 conn
->c_ping_triggered
= 1;
1253 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
1254 rds_send_probe(&conn
->c_path
[0], RDS_FLAG_PROBE_PORT
, 0, 0);