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
);
165 if (rds_destroy_pending(cp
->cp_conn
)) {
167 ret
= -ENETUNREACH
; /* dont requeue send work */
172 * we record the send generation after doing the xmit acquire.
173 * if someone else manages to jump in and do some work, we'll use
174 * this to avoid a goto restart farther down.
176 * The acquire_in_xmit() check above ensures that only one
177 * caller can increment c_send_gen at any time.
179 send_gen
= READ_ONCE(cp
->cp_send_gen
) + 1;
180 WRITE_ONCE(cp
->cp_send_gen
, send_gen
);
183 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
184 * we do the opposite to avoid races.
186 if (!rds_conn_path_up(cp
)) {
192 if (conn
->c_trans
->xmit_path_prepare
)
193 conn
->c_trans
->xmit_path_prepare(cp
);
196 * spin trying to push headers and data down the connection until
197 * the connection doesn't make forward progress.
204 * If between sending messages, we can send a pending congestion
207 if (!rm
&& test_and_clear_bit(0, &conn
->c_map_queued
)) {
208 rm
= rds_cong_update_alloc(conn
);
213 rm
->data
.op_active
= 1;
214 rm
->m_inc
.i_conn_path
= cp
;
215 rm
->m_inc
.i_conn
= cp
->cp_conn
;
221 * If not already working on one, grab the next message.
223 * cp_xmit_rm holds a ref while we're sending this message down
224 * the connction. We can use this ref while holding the
225 * send_sem.. rds_send_reset() is serialized with it.
232 /* we want to process as big a batch as we can, but
233 * we also want to avoid softlockups. If we've been
234 * through a lot of messages, lets back off and see
235 * if anyone else jumps in
237 if (batch_count
>= send_batch_count
)
240 spin_lock_irqsave(&cp
->cp_lock
, flags
);
242 if (!list_empty(&cp
->cp_send_queue
)) {
243 rm
= list_entry(cp
->cp_send_queue
.next
,
246 rds_message_addref(rm
);
249 * Move the message from the send queue to the retransmit
252 list_move_tail(&rm
->m_conn_item
,
256 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
261 /* Unfortunately, the way Infiniband deals with
262 * RDMA to a bad MR key is by moving the entire
263 * queue pair to error state. We cold possibly
264 * recover from that, but right now we drop the
266 * Therefore, we never retransmit messages with RDMA ops.
268 if (test_bit(RDS_MSG_FLUSH
, &rm
->m_flags
) ||
269 (rm
->rdma
.op_active
&&
270 test_bit(RDS_MSG_RETRANSMITTED
, &rm
->m_flags
))) {
271 spin_lock_irqsave(&cp
->cp_lock
, flags
);
272 if (test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
))
273 list_move(&rm
->m_conn_item
, &to_be_dropped
);
274 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
278 /* Require an ACK every once in a while */
279 len
= ntohl(rm
->m_inc
.i_hdr
.h_len
);
280 if (cp
->cp_unacked_packets
== 0 ||
281 cp
->cp_unacked_bytes
< len
) {
282 set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
284 cp
->cp_unacked_packets
=
285 rds_sysctl_max_unacked_packets
;
286 cp
->cp_unacked_bytes
=
287 rds_sysctl_max_unacked_bytes
;
288 rds_stats_inc(s_send_ack_required
);
290 cp
->cp_unacked_bytes
-= len
;
291 cp
->cp_unacked_packets
--;
297 /* The transport either sends the whole rdma or none of it */
298 if (rm
->rdma
.op_active
&& !cp
->cp_xmit_rdma_sent
) {
299 rm
->m_final_op
= &rm
->rdma
;
300 /* The transport owns the mapped memory for now.
301 * You can't unmap it while it's on the send queue
303 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
304 ret
= conn
->c_trans
->xmit_rdma(conn
, &rm
->rdma
);
306 clear_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
307 wake_up_interruptible(&rm
->m_flush_wait
);
310 cp
->cp_xmit_rdma_sent
= 1;
314 if (rm
->atomic
.op_active
&& !cp
->cp_xmit_atomic_sent
) {
315 rm
->m_final_op
= &rm
->atomic
;
316 /* The transport owns the mapped memory for now.
317 * You can't unmap it while it's on the send queue
319 set_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
320 ret
= conn
->c_trans
->xmit_atomic(conn
, &rm
->atomic
);
322 clear_bit(RDS_MSG_MAPPED
, &rm
->m_flags
);
323 wake_up_interruptible(&rm
->m_flush_wait
);
326 cp
->cp_xmit_atomic_sent
= 1;
331 * A number of cases require an RDS header to be sent
332 * even if there is no data.
333 * We permit 0-byte sends; rds-ping depends on this.
334 * However, if there are exclusively attached silent ops,
335 * we skip the hdr/data send, to enable silent operation.
337 if (rm
->data
.op_nents
== 0) {
339 int all_ops_are_silent
= 1;
341 ops_present
= (rm
->atomic
.op_active
|| rm
->rdma
.op_active
);
342 if (rm
->atomic
.op_active
&& !rm
->atomic
.op_silent
)
343 all_ops_are_silent
= 0;
344 if (rm
->rdma
.op_active
&& !rm
->rdma
.op_silent
)
345 all_ops_are_silent
= 0;
347 if (ops_present
&& all_ops_are_silent
348 && !rm
->m_rdma_cookie
)
349 rm
->data
.op_active
= 0;
352 if (rm
->data
.op_active
&& !cp
->cp_xmit_data_sent
) {
353 rm
->m_final_op
= &rm
->data
;
355 ret
= conn
->c_trans
->xmit(conn
, rm
,
358 cp
->cp_xmit_data_off
);
362 if (cp
->cp_xmit_hdr_off
< sizeof(struct rds_header
)) {
363 tmp
= min_t(int, ret
,
364 sizeof(struct rds_header
) -
365 cp
->cp_xmit_hdr_off
);
366 cp
->cp_xmit_hdr_off
+= tmp
;
370 sg
= &rm
->data
.op_sg
[cp
->cp_xmit_sg
];
372 tmp
= min_t(int, ret
, sg
->length
-
373 cp
->cp_xmit_data_off
);
374 cp
->cp_xmit_data_off
+= tmp
;
376 if (cp
->cp_xmit_data_off
== sg
->length
) {
377 cp
->cp_xmit_data_off
= 0;
380 BUG_ON(ret
!= 0 && cp
->cp_xmit_sg
==
385 if (cp
->cp_xmit_hdr_off
== sizeof(struct rds_header
) &&
386 (cp
->cp_xmit_sg
== rm
->data
.op_nents
))
387 cp
->cp_xmit_data_sent
= 1;
391 * A rm will only take multiple times through this loop
392 * if there is a data op. Thus, if the data is sent (or there was
393 * none), then we're done with the rm.
395 if (!rm
->data
.op_active
|| cp
->cp_xmit_data_sent
) {
396 cp
->cp_xmit_rm
= NULL
;
398 cp
->cp_xmit_hdr_off
= 0;
399 cp
->cp_xmit_data_off
= 0;
400 cp
->cp_xmit_rdma_sent
= 0;
401 cp
->cp_xmit_atomic_sent
= 0;
402 cp
->cp_xmit_data_sent
= 0;
409 if (conn
->c_trans
->xmit_path_complete
)
410 conn
->c_trans
->xmit_path_complete(cp
);
413 /* Nuke any messages we decided not to retransmit. */
414 if (!list_empty(&to_be_dropped
)) {
415 /* irqs on here, so we can put(), unlike above */
416 list_for_each_entry(rm
, &to_be_dropped
, m_conn_item
)
418 rds_send_remove_from_sock(&to_be_dropped
, RDS_RDMA_DROPPED
);
422 * Other senders can queue a message after we last test the send queue
423 * but before we clear RDS_IN_XMIT. In that case they'd back off and
424 * not try and send their newly queued message. We need to check the
425 * send queue after having cleared RDS_IN_XMIT so that their message
426 * doesn't get stuck on the send queue.
428 * If the transport cannot continue (i.e ret != 0), then it must
429 * call us when more room is available, such as from the tx
430 * completion handler.
432 * We have an extra generation check here so that if someone manages
433 * to jump in after our release_in_xmit, we'll see that they have done
434 * some work and we will skip our goto
440 raced
= send_gen
!= READ_ONCE(cp
->cp_send_gen
);
442 if ((test_bit(0, &conn
->c_map_queued
) ||
443 !list_empty(&cp
->cp_send_queue
)) && !raced
) {
444 if (batch_count
< send_batch_count
)
447 if (rds_destroy_pending(cp
->cp_conn
))
450 queue_delayed_work(rds_wq
, &cp
->cp_send_w
, 1);
453 rds_stats_inc(s_send_lock_queue_raced
);
459 EXPORT_SYMBOL_GPL(rds_send_xmit
);
461 static void rds_send_sndbuf_remove(struct rds_sock
*rs
, struct rds_message
*rm
)
463 u32 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
465 assert_spin_locked(&rs
->rs_lock
);
467 BUG_ON(rs
->rs_snd_bytes
< len
);
468 rs
->rs_snd_bytes
-= len
;
470 if (rs
->rs_snd_bytes
== 0)
471 rds_stats_inc(s_send_queue_empty
);
474 static inline int rds_send_is_acked(struct rds_message
*rm
, u64 ack
,
475 is_acked_func is_acked
)
478 return is_acked(rm
, ack
);
479 return be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
) <= ack
;
483 * This is pretty similar to what happens below in the ACK
484 * handling code - except that we call here as soon as we get
485 * the IB send completion on the RDMA op and the accompanying
488 void rds_rdma_send_complete(struct rds_message
*rm
, int status
)
490 struct rds_sock
*rs
= NULL
;
491 struct rm_rdma_op
*ro
;
492 struct rds_notifier
*notifier
;
494 unsigned int notify
= 0;
496 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
498 notify
= rm
->rdma
.op_notify
| rm
->data
.op_notify
;
500 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
) &&
501 ro
->op_active
&& notify
&& ro
->op_notifier
) {
502 notifier
= ro
->op_notifier
;
504 sock_hold(rds_rs_to_sk(rs
));
506 notifier
->n_status
= status
;
507 spin_lock(&rs
->rs_lock
);
508 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
509 spin_unlock(&rs
->rs_lock
);
511 ro
->op_notifier
= NULL
;
514 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
517 rds_wake_sk_sleep(rs
);
518 sock_put(rds_rs_to_sk(rs
));
521 EXPORT_SYMBOL_GPL(rds_rdma_send_complete
);
524 * Just like above, except looks at atomic op
526 void rds_atomic_send_complete(struct rds_message
*rm
, int status
)
528 struct rds_sock
*rs
= NULL
;
529 struct rm_atomic_op
*ao
;
530 struct rds_notifier
*notifier
;
533 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
536 if (test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)
537 && ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
538 notifier
= ao
->op_notifier
;
540 sock_hold(rds_rs_to_sk(rs
));
542 notifier
->n_status
= status
;
543 spin_lock(&rs
->rs_lock
);
544 list_add_tail(¬ifier
->n_list
, &rs
->rs_notify_queue
);
545 spin_unlock(&rs
->rs_lock
);
547 ao
->op_notifier
= NULL
;
550 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
553 rds_wake_sk_sleep(rs
);
554 sock_put(rds_rs_to_sk(rs
));
557 EXPORT_SYMBOL_GPL(rds_atomic_send_complete
);
560 * This is the same as rds_rdma_send_complete except we
561 * don't do any locking - we have all the ingredients (message,
562 * socket, socket lock) and can just move the notifier.
565 __rds_send_complete(struct rds_sock
*rs
, struct rds_message
*rm
, int status
)
567 struct rm_rdma_op
*ro
;
568 struct rm_atomic_op
*ao
;
571 if (ro
->op_active
&& ro
->op_notify
&& ro
->op_notifier
) {
572 ro
->op_notifier
->n_status
= status
;
573 list_add_tail(&ro
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
574 ro
->op_notifier
= NULL
;
578 if (ao
->op_active
&& ao
->op_notify
&& ao
->op_notifier
) {
579 ao
->op_notifier
->n_status
= status
;
580 list_add_tail(&ao
->op_notifier
->n_list
, &rs
->rs_notify_queue
);
581 ao
->op_notifier
= NULL
;
584 /* No need to wake the app - caller does this */
588 * This removes messages from the socket's list if they're on it. The list
589 * argument must be private to the caller, we must be able to modify it
590 * without locks. The messages must have a reference held for their
591 * position on the list. This function will drop that reference after
592 * removing the messages from the 'messages' list regardless of if it found
593 * the messages on the socket list or not.
595 static void rds_send_remove_from_sock(struct list_head
*messages
, int status
)
598 struct rds_sock
*rs
= NULL
;
599 struct rds_message
*rm
;
601 while (!list_empty(messages
)) {
604 rm
= list_entry(messages
->next
, struct rds_message
,
606 list_del_init(&rm
->m_conn_item
);
609 * If we see this flag cleared then we're *sure* that someone
610 * else beat us to removing it from the sock. If we race
611 * with their flag update we'll get the lock and then really
612 * see that the flag has been cleared.
614 * The message spinlock makes sure nobody clears rm->m_rs
615 * while we're messing with it. It does not prevent the
616 * message from being removed from the socket, though.
618 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
619 if (!test_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
))
620 goto unlock_and_drop
;
622 if (rs
!= rm
->m_rs
) {
624 rds_wake_sk_sleep(rs
);
625 sock_put(rds_rs_to_sk(rs
));
629 sock_hold(rds_rs_to_sk(rs
));
632 goto unlock_and_drop
;
633 spin_lock(&rs
->rs_lock
);
635 if (test_and_clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
)) {
636 struct rm_rdma_op
*ro
= &rm
->rdma
;
637 struct rds_notifier
*notifier
;
639 list_del_init(&rm
->m_sock_item
);
640 rds_send_sndbuf_remove(rs
, rm
);
642 if (ro
->op_active
&& ro
->op_notifier
&&
643 (ro
->op_notify
|| (ro
->op_recverr
&& status
))) {
644 notifier
= ro
->op_notifier
;
645 list_add_tail(¬ifier
->n_list
,
646 &rs
->rs_notify_queue
);
647 if (!notifier
->n_status
)
648 notifier
->n_status
= status
;
649 rm
->rdma
.op_notifier
= NULL
;
653 spin_unlock(&rs
->rs_lock
);
656 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
663 rds_wake_sk_sleep(rs
);
664 sock_put(rds_rs_to_sk(rs
));
669 * Transports call here when they've determined that the receiver queued
670 * messages up to, and including, the given sequence number. Messages are
671 * moved to the retrans queue when rds_send_xmit picks them off the send
672 * queue. This means that in the TCP case, the message may not have been
673 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
674 * checks the RDS_MSG_HAS_ACK_SEQ bit.
676 void rds_send_path_drop_acked(struct rds_conn_path
*cp
, u64 ack
,
677 is_acked_func is_acked
)
679 struct rds_message
*rm
, *tmp
;
683 spin_lock_irqsave(&cp
->cp_lock
, flags
);
685 list_for_each_entry_safe(rm
, tmp
, &cp
->cp_retrans
, m_conn_item
) {
686 if (!rds_send_is_acked(rm
, ack
, is_acked
))
689 list_move(&rm
->m_conn_item
, &list
);
690 clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
693 /* order flag updates with spin locks */
694 if (!list_empty(&list
))
695 smp_mb__after_atomic();
697 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
699 /* now remove the messages from the sock list as needed */
700 rds_send_remove_from_sock(&list
, RDS_RDMA_SUCCESS
);
702 EXPORT_SYMBOL_GPL(rds_send_path_drop_acked
);
704 void rds_send_drop_acked(struct rds_connection
*conn
, u64 ack
,
705 is_acked_func is_acked
)
707 WARN_ON(conn
->c_trans
->t_mp_capable
);
708 rds_send_path_drop_acked(&conn
->c_path
[0], ack
, is_acked
);
710 EXPORT_SYMBOL_GPL(rds_send_drop_acked
);
712 void rds_send_drop_to(struct rds_sock
*rs
, struct sockaddr_in
*dest
)
714 struct rds_message
*rm
, *tmp
;
715 struct rds_connection
*conn
;
716 struct rds_conn_path
*cp
;
720 /* get all the messages we're dropping under the rs lock */
721 spin_lock_irqsave(&rs
->rs_lock
, flags
);
723 list_for_each_entry_safe(rm
, tmp
, &rs
->rs_send_queue
, m_sock_item
) {
724 if (dest
&& (dest
->sin_addr
.s_addr
!= rm
->m_daddr
||
725 dest
->sin_port
!= rm
->m_inc
.i_hdr
.h_dport
))
728 list_move(&rm
->m_sock_item
, &list
);
729 rds_send_sndbuf_remove(rs
, rm
);
730 clear_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
733 /* order flag updates with the rs lock */
734 smp_mb__after_atomic();
736 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
738 if (list_empty(&list
))
741 /* Remove the messages from the conn */
742 list_for_each_entry(rm
, &list
, m_sock_item
) {
744 conn
= rm
->m_inc
.i_conn
;
745 if (conn
->c_trans
->t_mp_capable
)
746 cp
= rm
->m_inc
.i_conn_path
;
748 cp
= &conn
->c_path
[0];
750 spin_lock_irqsave(&cp
->cp_lock
, flags
);
752 * Maybe someone else beat us to removing rm from the conn.
753 * If we race with their flag update we'll get the lock and
754 * then really see that the flag has been cleared.
756 if (!test_and_clear_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
)) {
757 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
760 list_del_init(&rm
->m_conn_item
);
761 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
764 * Couldn't grab m_rs_lock in top loop (lock ordering),
767 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
769 spin_lock(&rs
->rs_lock
);
770 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
771 spin_unlock(&rs
->rs_lock
);
773 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
778 rds_wake_sk_sleep(rs
);
780 while (!list_empty(&list
)) {
781 rm
= list_entry(list
.next
, struct rds_message
, m_sock_item
);
782 list_del_init(&rm
->m_sock_item
);
783 rds_message_wait(rm
);
785 /* just in case the code above skipped this message
786 * because RDS_MSG_ON_CONN wasn't set, run it again here
787 * taking m_rs_lock is the only thing that keeps us
788 * from racing with ack processing.
790 spin_lock_irqsave(&rm
->m_rs_lock
, flags
);
792 spin_lock(&rs
->rs_lock
);
793 __rds_send_complete(rs
, rm
, RDS_RDMA_CANCELED
);
794 spin_unlock(&rs
->rs_lock
);
796 spin_unlock_irqrestore(&rm
->m_rs_lock
, flags
);
803 * we only want this to fire once so we use the callers 'queued'. It's
804 * possible that another thread can race with us and remove the
805 * message from the flow with RDS_CANCEL_SENT_TO.
807 static int rds_send_queue_rm(struct rds_sock
*rs
, struct rds_connection
*conn
,
808 struct rds_conn_path
*cp
,
809 struct rds_message
*rm
, __be16 sport
,
810 __be16 dport
, int *queued
)
818 len
= be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
);
820 /* this is the only place which holds both the socket's rs_lock
821 * and the connection's c_lock */
822 spin_lock_irqsave(&rs
->rs_lock
, flags
);
825 * If there is a little space in sndbuf, we don't queue anything,
826 * and userspace gets -EAGAIN. But poll() indicates there's send
827 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
828 * freed up by incoming acks. So we check the *old* value of
829 * rs_snd_bytes here to allow the last msg to exceed the buffer,
830 * and poll() now knows no more data can be sent.
832 if (rs
->rs_snd_bytes
< rds_sk_sndbuf(rs
)) {
833 rs
->rs_snd_bytes
+= len
;
835 /* let recv side know we are close to send space exhaustion.
836 * This is probably not the optimal way to do it, as this
837 * means we set the flag on *all* messages as soon as our
838 * throughput hits a certain threshold.
840 if (rs
->rs_snd_bytes
>= rds_sk_sndbuf(rs
) / 2)
841 set_bit(RDS_MSG_ACK_REQUIRED
, &rm
->m_flags
);
843 list_add_tail(&rm
->m_sock_item
, &rs
->rs_send_queue
);
844 set_bit(RDS_MSG_ON_SOCK
, &rm
->m_flags
);
845 rds_message_addref(rm
);
846 sock_hold(rds_rs_to_sk(rs
));
849 /* The code ordering is a little weird, but we're
850 trying to minimize the time we hold c_lock */
851 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
, 0);
852 rm
->m_inc
.i_conn
= conn
;
853 rm
->m_inc
.i_conn_path
= cp
;
854 rds_message_addref(rm
);
856 spin_lock(&cp
->cp_lock
);
857 rm
->m_inc
.i_hdr
.h_sequence
= cpu_to_be64(cp
->cp_next_tx_seq
++);
858 list_add_tail(&rm
->m_conn_item
, &cp
->cp_send_queue
);
859 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
860 spin_unlock(&cp
->cp_lock
);
862 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
863 rm
, len
, rs
, rs
->rs_snd_bytes
,
864 (unsigned long long)be64_to_cpu(rm
->m_inc
.i_hdr
.h_sequence
));
869 spin_unlock_irqrestore(&rs
->rs_lock
, flags
);
875 * rds_message is getting to be quite complicated, and we'd like to allocate
876 * it all in one go. This figures out how big it needs to be up front.
878 static int rds_rm_size(struct msghdr
*msg
, int num_sgs
)
880 struct cmsghdr
*cmsg
;
884 bool zcopy_cookie
= false;
886 for_each_cmsghdr(cmsg
, msg
) {
887 if (!CMSG_OK(msg
, cmsg
))
890 if (cmsg
->cmsg_level
!= SOL_RDS
)
893 switch (cmsg
->cmsg_type
) {
894 case RDS_CMSG_RDMA_ARGS
:
896 retval
= rds_rdma_extra_size(CMSG_DATA(cmsg
));
903 case RDS_CMSG_ZCOPY_COOKIE
:
905 case RDS_CMSG_RDMA_DEST
:
906 case RDS_CMSG_RDMA_MAP
:
908 /* these are valid but do no add any size */
911 case RDS_CMSG_ATOMIC_CSWP
:
912 case RDS_CMSG_ATOMIC_FADD
:
913 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
914 case RDS_CMSG_MASKED_ATOMIC_FADD
:
916 size
+= sizeof(struct scatterlist
);
925 if ((msg
->msg_flags
& MSG_ZEROCOPY
) && !zcopy_cookie
)
928 size
+= num_sgs
* sizeof(struct scatterlist
);
930 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
931 if (cmsg_groups
== 3)
937 static int rds_cmsg_zcopy(struct rds_sock
*rs
, struct rds_message
*rm
,
938 struct cmsghdr
*cmsg
)
942 if (cmsg
->cmsg_len
< CMSG_LEN(sizeof(*cookie
)))
944 cookie
= CMSG_DATA(cmsg
);
945 rm
->data
.op_mmp_znotifier
->z_cookie
= *cookie
;
949 static int rds_cmsg_send(struct rds_sock
*rs
, struct rds_message
*rm
,
950 struct msghdr
*msg
, int *allocated_mr
)
952 struct cmsghdr
*cmsg
;
955 for_each_cmsghdr(cmsg
, msg
) {
956 if (!CMSG_OK(msg
, cmsg
))
959 if (cmsg
->cmsg_level
!= SOL_RDS
)
962 /* As a side effect, RDMA_DEST and RDMA_MAP will set
963 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
965 switch (cmsg
->cmsg_type
) {
966 case RDS_CMSG_RDMA_ARGS
:
967 ret
= rds_cmsg_rdma_args(rs
, rm
, cmsg
);
970 case RDS_CMSG_RDMA_DEST
:
971 ret
= rds_cmsg_rdma_dest(rs
, rm
, cmsg
);
974 case RDS_CMSG_RDMA_MAP
:
975 ret
= rds_cmsg_rdma_map(rs
, rm
, cmsg
);
978 else if (ret
== -ENODEV
)
979 /* Accommodate the get_mr() case which can fail
980 * if connection isn't established yet.
984 case RDS_CMSG_ATOMIC_CSWP
:
985 case RDS_CMSG_ATOMIC_FADD
:
986 case RDS_CMSG_MASKED_ATOMIC_CSWP
:
987 case RDS_CMSG_MASKED_ATOMIC_FADD
:
988 ret
= rds_cmsg_atomic(rs
, rm
, cmsg
);
991 case RDS_CMSG_ZCOPY_COOKIE
:
992 ret
= rds_cmsg_zcopy(rs
, rm
, cmsg
);
1006 static int rds_send_mprds_hash(struct rds_sock
*rs
, struct rds_connection
*conn
)
1010 if (conn
->c_npaths
== 0)
1011 hash
= RDS_MPATH_HASH(rs
, RDS_MPATH_WORKERS
);
1013 hash
= RDS_MPATH_HASH(rs
, conn
->c_npaths
);
1014 if (conn
->c_npaths
== 0 && hash
!= 0) {
1015 rds_send_ping(conn
, 0);
1017 if (conn
->c_npaths
== 0) {
1018 wait_event_interruptible(conn
->c_hs_waitq
,
1019 (conn
->c_npaths
!= 0));
1021 if (conn
->c_npaths
== 1)
1027 static int rds_rdma_bytes(struct msghdr
*msg
, size_t *rdma_bytes
)
1029 struct rds_rdma_args
*args
;
1030 struct cmsghdr
*cmsg
;
1032 for_each_cmsghdr(cmsg
, msg
) {
1033 if (!CMSG_OK(msg
, cmsg
))
1036 if (cmsg
->cmsg_level
!= SOL_RDS
)
1039 if (cmsg
->cmsg_type
== RDS_CMSG_RDMA_ARGS
) {
1040 if (cmsg
->cmsg_len
<
1041 CMSG_LEN(sizeof(struct rds_rdma_args
)))
1043 args
= CMSG_DATA(cmsg
);
1044 *rdma_bytes
+= args
->remote_vec
.bytes
;
1050 int rds_sendmsg(struct socket
*sock
, struct msghdr
*msg
, size_t payload_len
)
1052 struct sock
*sk
= sock
->sk
;
1053 struct rds_sock
*rs
= rds_sk_to_rs(sk
);
1054 DECLARE_SOCKADDR(struct sockaddr_in
*, usin
, msg
->msg_name
);
1057 struct rds_message
*rm
= NULL
;
1058 struct rds_connection
*conn
;
1060 int queued
= 0, allocated_mr
= 0;
1061 int nonblock
= msg
->msg_flags
& MSG_DONTWAIT
;
1062 long timeo
= sock_sndtimeo(sk
, nonblock
);
1063 struct rds_conn_path
*cpath
;
1064 size_t total_payload_len
= payload_len
, rdma_payload_len
= 0;
1065 bool zcopy
= ((msg
->msg_flags
& MSG_ZEROCOPY
) &&
1066 sock_flag(rds_rs_to_sk(rs
), SOCK_ZEROCOPY
));
1067 int num_sgs
= ceil(payload_len
, PAGE_SIZE
);
1069 /* Mirror Linux UDP mirror of BSD error message compatibility */
1070 /* XXX: Perhaps MSG_MORE someday */
1071 if (msg
->msg_flags
& ~(MSG_DONTWAIT
| MSG_CMSG_COMPAT
| MSG_ZEROCOPY
)) {
1076 if (msg
->msg_namelen
) {
1077 /* XXX fail non-unicast destination IPs? */
1078 if (msg
->msg_namelen
< sizeof(*usin
) || usin
->sin_family
!= AF_INET
) {
1082 daddr
= usin
->sin_addr
.s_addr
;
1083 dport
= usin
->sin_port
;
1085 /* We only care about consistency with ->connect() */
1087 daddr
= rs
->rs_conn_addr
;
1088 dport
= rs
->rs_conn_port
;
1093 if (daddr
== 0 || rs
->rs_bound_addr
== 0) {
1095 ret
= -ENOTCONN
; /* XXX not a great errno */
1100 ret
= rds_rdma_bytes(msg
, &rdma_payload_len
);
1104 total_payload_len
+= rdma_payload_len
;
1105 if (max_t(size_t, payload_len
, rdma_payload_len
) > RDS_MAX_MSG_SIZE
) {
1110 if (payload_len
> rds_sk_sndbuf(rs
)) {
1116 if (rs
->rs_transport
->t_type
!= RDS_TRANS_TCP
) {
1120 num_sgs
= iov_iter_npages(&msg
->msg_iter
, INT_MAX
);
1122 /* size of rm including all sgs */
1123 ret
= rds_rm_size(msg
, num_sgs
);
1127 rm
= rds_message_alloc(ret
, GFP_KERNEL
);
1133 /* Attach data to the rm */
1135 rm
->data
.op_sg
= rds_message_alloc_sgs(rm
, num_sgs
);
1136 if (!rm
->data
.op_sg
) {
1140 ret
= rds_message_copy_from_user(rm
, &msg
->msg_iter
, zcopy
);
1144 rm
->data
.op_active
= 1;
1146 rm
->m_daddr
= daddr
;
1148 /* rds_conn_create has a spinlock that runs with IRQ off.
1149 * Caching the conn in the socket helps a lot. */
1150 if (rs
->rs_conn
&& rs
->rs_conn
->c_faddr
== daddr
)
1153 conn
= rds_conn_create_outgoing(sock_net(sock
->sk
),
1154 rs
->rs_bound_addr
, daddr
,
1156 sock
->sk
->sk_allocation
);
1158 ret
= PTR_ERR(conn
);
1164 /* Parse any control messages the user may have included. */
1165 ret
= rds_cmsg_send(rs
, rm
, msg
, &allocated_mr
);
1167 /* Trigger connection so that its ready for the next retry */
1169 rds_conn_connect_if_down(conn
);
1173 if (rm
->rdma
.op_active
&& !conn
->c_trans
->xmit_rdma
) {
1174 printk_ratelimited(KERN_NOTICE
"rdma_op %p conn xmit_rdma %p\n",
1175 &rm
->rdma
, conn
->c_trans
->xmit_rdma
);
1180 if (rm
->atomic
.op_active
&& !conn
->c_trans
->xmit_atomic
) {
1181 printk_ratelimited(KERN_NOTICE
"atomic_op %p conn xmit_atomic %p\n",
1182 &rm
->atomic
, conn
->c_trans
->xmit_atomic
);
1187 if (conn
->c_trans
->t_mp_capable
)
1188 cpath
= &conn
->c_path
[rds_send_mprds_hash(rs
, conn
)];
1190 cpath
= &conn
->c_path
[0];
1192 if (rds_destroy_pending(conn
)) {
1197 rds_conn_path_connect_if_down(cpath
);
1199 ret
= rds_cong_wait(conn
->c_fcong
, dport
, nonblock
, rs
);
1201 rs
->rs_seen_congestion
= 1;
1204 while (!rds_send_queue_rm(rs
, conn
, cpath
, rm
, rs
->rs_bound_port
,
1206 rds_stats_inc(s_send_queue_full
);
1213 timeo
= wait_event_interruptible_timeout(*sk_sleep(sk
),
1214 rds_send_queue_rm(rs
, conn
, cpath
, rm
,
1219 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued
, timeo
);
1220 if (timeo
> 0 || timeo
== MAX_SCHEDULE_TIMEOUT
)
1230 * By now we've committed to the send. We reuse rds_send_worker()
1231 * to retry sends in the rds thread if the transport asks us to.
1233 rds_stats_inc(s_send_queued
);
1235 ret
= rds_send_xmit(cpath
);
1236 if (ret
== -ENOMEM
|| ret
== -EAGAIN
) {
1239 if (rds_destroy_pending(cpath
->cp_conn
))
1242 queue_delayed_work(rds_wq
, &cpath
->cp_send_w
, 1);
1247 rds_message_put(rm
);
1251 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1252 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1253 * or in any other way, we need to destroy the MR again */
1255 rds_rdma_unuse(rs
, rds_rdma_cookie_key(rm
->m_rdma_cookie
), 1);
1258 rds_message_put(rm
);
1263 * send out a probe. Can be shared by rds_send_ping,
1264 * rds_send_pong, rds_send_hb.
1265 * rds_send_hb should use h_flags
1266 * RDS_FLAG_HB_PING|RDS_FLAG_ACK_REQUIRED
1268 * RDS_FLAG_HB_PONG|RDS_FLAG_ACK_REQUIRED
1271 rds_send_probe(struct rds_conn_path
*cp
, __be16 sport
,
1272 __be16 dport
, u8 h_flags
)
1274 struct rds_message
*rm
;
1275 unsigned long flags
;
1278 rm
= rds_message_alloc(0, GFP_ATOMIC
);
1284 rm
->m_daddr
= cp
->cp_conn
->c_faddr
;
1285 rm
->data
.op_active
= 1;
1287 rds_conn_path_connect_if_down(cp
);
1289 ret
= rds_cong_wait(cp
->cp_conn
->c_fcong
, dport
, 1, NULL
);
1293 spin_lock_irqsave(&cp
->cp_lock
, flags
);
1294 list_add_tail(&rm
->m_conn_item
, &cp
->cp_send_queue
);
1295 set_bit(RDS_MSG_ON_CONN
, &rm
->m_flags
);
1296 rds_message_addref(rm
);
1297 rm
->m_inc
.i_conn
= cp
->cp_conn
;
1298 rm
->m_inc
.i_conn_path
= cp
;
1300 rds_message_populate_header(&rm
->m_inc
.i_hdr
, sport
, dport
,
1301 cp
->cp_next_tx_seq
);
1302 rm
->m_inc
.i_hdr
.h_flags
|= h_flags
;
1303 cp
->cp_next_tx_seq
++;
1305 if (RDS_HS_PROBE(be16_to_cpu(sport
), be16_to_cpu(dport
)) &&
1306 cp
->cp_conn
->c_trans
->t_mp_capable
) {
1307 u16 npaths
= cpu_to_be16(RDS_MPATH_WORKERS
);
1308 u32 my_gen_num
= cpu_to_be32(cp
->cp_conn
->c_my_gen_num
);
1310 rds_message_add_extension(&rm
->m_inc
.i_hdr
,
1311 RDS_EXTHDR_NPATHS
, &npaths
,
1313 rds_message_add_extension(&rm
->m_inc
.i_hdr
,
1318 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
1320 rds_stats_inc(s_send_queued
);
1321 rds_stats_inc(s_send_pong
);
1323 /* schedule the send work on rds_wq */
1325 if (!rds_destroy_pending(cp
->cp_conn
))
1326 queue_delayed_work(rds_wq
, &cp
->cp_send_w
, 1);
1329 rds_message_put(rm
);
1334 rds_message_put(rm
);
1339 rds_send_pong(struct rds_conn_path
*cp
, __be16 dport
)
1341 return rds_send_probe(cp
, 0, dport
, 0);
1345 rds_send_ping(struct rds_connection
*conn
, int cp_index
)
1347 unsigned long flags
;
1348 struct rds_conn_path
*cp
= &conn
->c_path
[cp_index
];
1350 spin_lock_irqsave(&cp
->cp_lock
, flags
);
1351 if (conn
->c_ping_triggered
) {
1352 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
1355 conn
->c_ping_triggered
= 1;
1356 spin_unlock_irqrestore(&cp
->cp_lock
, flags
);
1357 rds_send_probe(cp
, cpu_to_be16(RDS_FLAG_PROBE_PORT
), 0, 0);
1359 EXPORT_SYMBOL_GPL(rds_send_ping
);