2 * Copyright (c) 2006 Oracle. All rights reserved.
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 #include <linux/kernel.h>
34 #include <linux/gfp.h>
37 #include <linux/list.h>
41 /* When transmitting messages in rds_send_xmit, we need to emerge from
42 * time to time and briefly release the CPU. Otherwise the softlock watchdog
44 * Also, it seems fairer to not let one busy connection stall all the
47 * send_batch_count is the number of times we'll loop in send_xmit. Setting
48 * it to 0 will restore the old behavior (where we looped until we had
51 static int send_batch_count = 64;
52 module_param(send_batch_count, int, 0444);
53 MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
56 * Reset the send state. Caller must hold c_send_lock when calling here.
58 void rds_send_reset(struct rds_connection *conn)
60 struct rds_message *rm, *tmp;
63 if (conn->c_xmit_rm) {
64 /* Tell the user the RDMA op is no longer mapped by the
65 * transport. This isn't entirely true (it's flushed out
66 * independently) but as the connection is down, there's
67 * no ongoing RDMA to/from that memory */
68 rds_message_unmapped(conn->c_xmit_rm);
69 rds_message_put(conn->c_xmit_rm);
70 conn->c_xmit_rm = NULL;
73 conn->c_xmit_hdr_off = 0;
74 conn->c_xmit_data_off = 0;
75 conn->c_xmit_atomic_sent = 0;
76 conn->c_xmit_rdma_sent = 0;
77 conn->c_xmit_data_sent = 0;
79 conn->c_map_queued = 0;
81 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
82 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
84 /* Mark messages as retransmissions, and move them to the send q */
85 spin_lock_irqsave(&conn->c_lock, flags);
86 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
87 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
88 set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
90 list_splice_init(&conn->c_retrans, &conn->c_send_queue);
91 spin_unlock_irqrestore(&conn->c_lock, flags);
95 * We're making the concious trade-off here to only send one message
96 * down the connection at a time.
98 * - tx queueing is a simple fifo list
99 * - reassembly is optional and easily done by transports per conn
100 * - no per flow rx lookup at all, straight to the socket
101 * - less per-frag memory and wire overhead
103 * - queued acks can be delayed behind large messages
105 * - small message latency is higher behind queued large messages
106 * - large message latency isn't starved by intervening small sends
108 int rds_send_xmit(struct rds_connection *conn)
110 struct rds_message *rm;
113 unsigned int send_quota = send_batch_count;
114 struct scatterlist *sg;
117 LIST_HEAD(to_be_dropped);
119 if (!rds_conn_up(conn))
123 * sendmsg calls here after having queued its message on the send
124 * queue. We only have one task feeding the connection at a time. If
125 * another thread is already feeding the queue then we back off. This
126 * avoids blocking the caller and trading per-connection data between
127 * caches per message.
129 if (!spin_trylock_irqsave(&conn->c_send_lock, flags)) {
130 rds_stats_inc(s_send_lock_contention);
135 if (conn->c_trans->xmit_prepare)
136 conn->c_trans->xmit_prepare(conn);
139 * spin trying to push headers and data down the connection until
140 * the connection doesn't make forward progress.
142 while (--send_quota) {
144 rm = conn->c_xmit_rm;
147 * If between sending messages, we can send a pending congestion
150 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
151 rm = rds_cong_update_alloc(conn);
156 rm->data.op_active = 1;
158 conn->c_xmit_rm = rm;
162 * If not already working on one, grab the next message.
164 * c_xmit_rm holds a ref while we're sending this message down
165 * the connction. We can use this ref while holding the
166 * send_sem.. rds_send_reset() is serialized with it.
171 spin_lock(&conn->c_lock);
173 if (!list_empty(&conn->c_send_queue)) {
174 rm = list_entry(conn->c_send_queue.next,
177 rds_message_addref(rm);
180 * Move the message from the send queue to the retransmit
183 list_move_tail(&rm->m_conn_item, &conn->c_retrans);
186 spin_unlock(&conn->c_lock);
193 /* Unfortunately, the way Infiniband deals with
194 * RDMA to a bad MR key is by moving the entire
195 * queue pair to error state. We cold possibly
196 * recover from that, but right now we drop the
198 * Therefore, we never retransmit messages with RDMA ops.
200 if (rm->rdma.op_active &&
201 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
202 spin_lock(&conn->c_lock);
203 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
204 list_move(&rm->m_conn_item, &to_be_dropped);
205 spin_unlock(&conn->c_lock);
209 /* Require an ACK every once in a while */
210 len = ntohl(rm->m_inc.i_hdr.h_len);
211 if (conn->c_unacked_packets == 0 ||
212 conn->c_unacked_bytes < len) {
213 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
215 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
216 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
217 rds_stats_inc(s_send_ack_required);
219 conn->c_unacked_bytes -= len;
220 conn->c_unacked_packets--;
223 conn->c_xmit_rm = rm;
226 /* The transport either sends the whole rdma or none of it */
227 if (rm->rdma.op_active && !conn->c_xmit_rdma_sent) {
228 rm->m_final_op = &rm->rdma;
229 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma);
232 conn->c_xmit_rdma_sent = 1;
234 /* The transport owns the mapped memory for now.
235 * You can't unmap it while it's on the send queue */
236 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
239 if (rm->atomic.op_active && !conn->c_xmit_atomic_sent) {
240 rm->m_final_op = &rm->atomic;
241 ret = conn->c_trans->xmit_atomic(conn, &rm->atomic);
244 conn->c_xmit_atomic_sent = 1;
246 /* The transport owns the mapped memory for now.
247 * You can't unmap it while it's on the send queue */
248 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
252 * A number of cases require an RDS header to be sent
253 * even if there is no data.
254 * We permit 0-byte sends; rds-ping depends on this.
255 * However, if there are exclusively attached silent ops,
256 * we skip the hdr/data send, to enable silent operation.
258 if (rm->data.op_nents == 0) {
260 int all_ops_are_silent = 1;
262 ops_present = (rm->atomic.op_active || rm->rdma.op_active);
263 if (rm->atomic.op_active && !rm->atomic.op_silent)
264 all_ops_are_silent = 0;
265 if (rm->rdma.op_active && !rm->rdma.op_silent)
266 all_ops_are_silent = 0;
268 if (ops_present && all_ops_are_silent
269 && !rm->m_rdma_cookie)
270 rm->data.op_active = 0;
273 if (rm->data.op_active && !conn->c_xmit_data_sent) {
274 rm->m_final_op = &rm->data;
275 ret = conn->c_trans->xmit(conn, rm,
276 conn->c_xmit_hdr_off,
278 conn->c_xmit_data_off);
282 if (conn->c_xmit_hdr_off < sizeof(struct rds_header)) {
283 tmp = min_t(int, ret,
284 sizeof(struct rds_header) -
285 conn->c_xmit_hdr_off);
286 conn->c_xmit_hdr_off += tmp;
290 sg = &rm->data.op_sg[conn->c_xmit_sg];
292 tmp = min_t(int, ret, sg->length -
293 conn->c_xmit_data_off);
294 conn->c_xmit_data_off += tmp;
296 if (conn->c_xmit_data_off == sg->length) {
297 conn->c_xmit_data_off = 0;
301 conn->c_xmit_sg == rm->data.op_nents);
305 if (conn->c_xmit_hdr_off == sizeof(struct rds_header) &&
306 (conn->c_xmit_sg == rm->data.op_nents))
307 conn->c_xmit_data_sent = 1;
311 * A rm will only take multiple times through this loop
312 * if there is a data op. Thus, if the data is sent (or there was
313 * none), then we're done with the rm.
315 if (!rm->data.op_active || conn->c_xmit_data_sent) {
316 conn->c_xmit_rm = NULL;
318 conn->c_xmit_hdr_off = 0;
319 conn->c_xmit_data_off = 0;
320 conn->c_xmit_rdma_sent = 0;
321 conn->c_xmit_atomic_sent = 0;
322 conn->c_xmit_data_sent = 0;
328 if (conn->c_trans->xmit_complete)
329 conn->c_trans->xmit_complete(conn);
332 * We might be racing with another sender who queued a message but
333 * backed off on noticing that we held the c_send_lock. If we check
334 * for queued messages after dropping the sem then either we'll
335 * see the queued message or the queuer will get the sem. If we
336 * notice the queued message then we trigger an immediate retry.
338 * We need to be careful only to do this when we stopped processing
339 * the send queue because it was empty. It's the only way we
340 * stop processing the loop when the transport hasn't taken
341 * responsibility for forward progress.
343 spin_unlock_irqrestore(&conn->c_send_lock, flags);
345 /* Nuke any messages we decided not to retransmit. */
346 if (!list_empty(&to_be_dropped)) {
347 /* irqs on here, so we can put(), unlike above */
348 list_for_each_entry(rm, &to_be_dropped, m_conn_item)
350 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
353 if (send_quota == 0 && !was_empty) {
354 /* We exhausted the send quota, but there's work left to
355 * do. Return and (re-)schedule the send worker.
360 if (ret == 0 && was_empty) {
361 /* A simple bit test would be way faster than taking the
363 spin_lock_irqsave(&conn->c_lock, flags);
364 if (!list_empty(&conn->c_send_queue)) {
365 rds_stats_inc(s_send_lock_queue_raced);
368 spin_unlock_irqrestore(&conn->c_lock, flags);
374 static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
376 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
378 assert_spin_locked(&rs->rs_lock);
380 BUG_ON(rs->rs_snd_bytes < len);
381 rs->rs_snd_bytes -= len;
383 if (rs->rs_snd_bytes == 0)
384 rds_stats_inc(s_send_queue_empty);
387 static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
388 is_acked_func is_acked)
391 return is_acked(rm, ack);
392 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
396 * Returns true if there are no messages on the send and retransmit queues
397 * which have a sequence number greater than or equal to the given sequence
400 int rds_send_acked_before(struct rds_connection *conn, u64 seq)
402 struct rds_message *rm, *tmp;
405 spin_lock(&conn->c_lock);
407 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
408 if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
413 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
414 if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
419 spin_unlock(&conn->c_lock);
425 * This is pretty similar to what happens below in the ACK
426 * handling code - except that we call here as soon as we get
427 * the IB send completion on the RDMA op and the accompanying
430 void rds_rdma_send_complete(struct rds_message *rm, int status)
432 struct rds_sock *rs = NULL;
433 struct rm_rdma_op *ro;
434 struct rds_notifier *notifier;
437 spin_lock_irqsave(&rm->m_rs_lock, flags);
440 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
441 ro->op_active && ro->op_notify && ro->op_notifier) {
442 notifier = ro->op_notifier;
444 sock_hold(rds_rs_to_sk(rs));
446 notifier->n_status = status;
447 spin_lock(&rs->rs_lock);
448 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
449 spin_unlock(&rs->rs_lock);
451 ro->op_notifier = NULL;
454 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
457 rds_wake_sk_sleep(rs);
458 sock_put(rds_rs_to_sk(rs));
461 EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
464 * Just like above, except looks at atomic op
466 void rds_atomic_send_complete(struct rds_message *rm, int status)
468 struct rds_sock *rs = NULL;
469 struct rm_atomic_op *ao;
470 struct rds_notifier *notifier;
472 spin_lock(&rm->m_rs_lock);
475 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
476 && ao->op_active && ao->op_notify && ao->op_notifier) {
477 notifier = ao->op_notifier;
479 sock_hold(rds_rs_to_sk(rs));
481 notifier->n_status = status;
482 spin_lock(&rs->rs_lock);
483 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
484 spin_unlock(&rs->rs_lock);
486 ao->op_notifier = NULL;
489 spin_unlock(&rm->m_rs_lock);
492 rds_wake_sk_sleep(rs);
493 sock_put(rds_rs_to_sk(rs));
496 EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
499 * This is the same as rds_rdma_send_complete except we
500 * don't do any locking - we have all the ingredients (message,
501 * socket, socket lock) and can just move the notifier.
504 __rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
506 struct rm_rdma_op *ro;
507 struct rm_atomic_op *ao;
510 if (ro->op_active && ro->op_notify && ro->op_notifier) {
511 ro->op_notifier->n_status = status;
512 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
513 ro->op_notifier = NULL;
517 if (ao->op_active && ao->op_notify && ao->op_notifier) {
518 ao->op_notifier->n_status = status;
519 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
520 ao->op_notifier = NULL;
523 /* No need to wake the app - caller does this */
527 * This is called from the IB send completion when we detect
528 * a RDMA operation that failed with remote access error.
529 * So speed is not an issue here.
531 struct rds_message *rds_send_get_message(struct rds_connection *conn,
532 struct rm_rdma_op *op)
534 struct rds_message *rm, *tmp, *found = NULL;
537 spin_lock_irqsave(&conn->c_lock, flags);
539 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
540 if (&rm->rdma == op) {
541 atomic_inc(&rm->m_refcount);
547 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
548 if (&rm->rdma == op) {
549 atomic_inc(&rm->m_refcount);
556 spin_unlock_irqrestore(&conn->c_lock, flags);
560 EXPORT_SYMBOL_GPL(rds_send_get_message);
563 * This removes messages from the socket's list if they're on it. The list
564 * argument must be private to the caller, we must be able to modify it
565 * without locks. The messages must have a reference held for their
566 * position on the list. This function will drop that reference after
567 * removing the messages from the 'messages' list regardless of if it found
568 * the messages on the socket list or not.
570 void rds_send_remove_from_sock(struct list_head *messages, int status)
573 struct rds_sock *rs = NULL;
574 struct rds_message *rm;
576 while (!list_empty(messages)) {
579 rm = list_entry(messages->next, struct rds_message,
581 list_del_init(&rm->m_conn_item);
584 * If we see this flag cleared then we're *sure* that someone
585 * else beat us to removing it from the sock. If we race
586 * with their flag update we'll get the lock and then really
587 * see that the flag has been cleared.
589 * The message spinlock makes sure nobody clears rm->m_rs
590 * while we're messing with it. It does not prevent the
591 * message from being removed from the socket, though.
593 spin_lock_irqsave(&rm->m_rs_lock, flags);
594 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
595 goto unlock_and_drop;
597 if (rs != rm->m_rs) {
599 rds_wake_sk_sleep(rs);
600 sock_put(rds_rs_to_sk(rs));
603 sock_hold(rds_rs_to_sk(rs));
605 spin_lock(&rs->rs_lock);
607 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
608 struct rm_rdma_op *ro = &rm->rdma;
609 struct rds_notifier *notifier;
611 list_del_init(&rm->m_sock_item);
612 rds_send_sndbuf_remove(rs, rm);
614 if (ro->op_active && ro->op_notifier &&
615 (ro->op_notify || (ro->op_recverr && status))) {
616 notifier = ro->op_notifier;
617 list_add_tail(¬ifier->n_list,
618 &rs->rs_notify_queue);
619 if (!notifier->n_status)
620 notifier->n_status = status;
621 rm->rdma.op_notifier = NULL;
626 spin_unlock(&rs->rs_lock);
629 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
636 rds_wake_sk_sleep(rs);
637 sock_put(rds_rs_to_sk(rs));
642 * Transports call here when they've determined that the receiver queued
643 * messages up to, and including, the given sequence number. Messages are
644 * moved to the retrans queue when rds_send_xmit picks them off the send
645 * queue. This means that in the TCP case, the message may not have been
646 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
647 * checks the RDS_MSG_HAS_ACK_SEQ bit.
649 * XXX It's not clear to me how this is safely serialized with socket
650 * destruction. Maybe it should bail if it sees SOCK_DEAD.
652 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
653 is_acked_func is_acked)
655 struct rds_message *rm, *tmp;
659 spin_lock_irqsave(&conn->c_lock, flags);
661 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
662 if (!rds_send_is_acked(rm, ack, is_acked))
665 list_move(&rm->m_conn_item, &list);
666 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
669 /* order flag updates with spin locks */
670 if (!list_empty(&list))
671 smp_mb__after_clear_bit();
673 spin_unlock_irqrestore(&conn->c_lock, flags);
675 /* now remove the messages from the sock list as needed */
676 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
678 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
680 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
682 struct rds_message *rm, *tmp;
683 struct rds_connection *conn;
687 /* get all the messages we're dropping under the rs lock */
688 spin_lock_irqsave(&rs->rs_lock, flags);
690 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
691 if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
692 dest->sin_port != rm->m_inc.i_hdr.h_dport))
695 list_move(&rm->m_sock_item, &list);
696 rds_send_sndbuf_remove(rs, rm);
697 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
700 /* order flag updates with the rs lock */
701 smp_mb__after_clear_bit();
703 spin_unlock_irqrestore(&rs->rs_lock, flags);
705 if (list_empty(&list))
708 /* Remove the messages from the conn */
709 list_for_each_entry(rm, &list, m_sock_item) {
711 conn = rm->m_inc.i_conn;
713 spin_lock_irqsave(&conn->c_lock, flags);
715 * Maybe someone else beat us to removing rm from the conn.
716 * If we race with their flag update we'll get the lock and
717 * then really see that the flag has been cleared.
719 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
720 spin_unlock_irqrestore(&conn->c_lock, flags);
723 list_del_init(&rm->m_conn_item);
724 spin_unlock_irqrestore(&conn->c_lock, flags);
727 * Couldn't grab m_rs_lock in top loop (lock ordering),
730 spin_lock_irqsave(&rm->m_rs_lock, flags);
732 spin_lock(&rs->rs_lock);
733 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
734 spin_unlock(&rs->rs_lock);
737 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
742 rds_wake_sk_sleep(rs);
744 while (!list_empty(&list)) {
745 rm = list_entry(list.next, struct rds_message, m_sock_item);
746 list_del_init(&rm->m_sock_item);
748 rds_message_wait(rm);
754 * we only want this to fire once so we use the callers 'queued'. It's
755 * possible that another thread can race with us and remove the
756 * message from the flow with RDS_CANCEL_SENT_TO.
758 static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
759 struct rds_message *rm, __be16 sport,
760 __be16 dport, int *queued)
768 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
770 /* this is the only place which holds both the socket's rs_lock
771 * and the connection's c_lock */
772 spin_lock_irqsave(&rs->rs_lock, flags);
775 * If there is a little space in sndbuf, we don't queue anything,
776 * and userspace gets -EAGAIN. But poll() indicates there's send
777 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
778 * freed up by incoming acks. So we check the *old* value of
779 * rs_snd_bytes here to allow the last msg to exceed the buffer,
780 * and poll() now knows no more data can be sent.
782 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
783 rs->rs_snd_bytes += len;
785 /* let recv side know we are close to send space exhaustion.
786 * This is probably not the optimal way to do it, as this
787 * means we set the flag on *all* messages as soon as our
788 * throughput hits a certain threshold.
790 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
791 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
793 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
794 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
795 rds_message_addref(rm);
798 /* The code ordering is a little weird, but we're
799 trying to minimize the time we hold c_lock */
800 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
801 rm->m_inc.i_conn = conn;
802 rds_message_addref(rm);
804 spin_lock(&conn->c_lock);
805 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++);
806 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
807 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
808 spin_unlock(&conn->c_lock);
810 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
811 rm, len, rs, rs->rs_snd_bytes,
812 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
817 spin_unlock_irqrestore(&rs->rs_lock, flags);
823 * rds_message is getting to be quite complicated, and we'd like to allocate
824 * it all in one go. This figures out how big it needs to be up front.
826 static int rds_rm_size(struct msghdr *msg, int data_len)
828 struct cmsghdr *cmsg;
833 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
834 if (!CMSG_OK(msg, cmsg))
837 if (cmsg->cmsg_level != SOL_RDS)
840 switch (cmsg->cmsg_type) {
841 case RDS_CMSG_RDMA_ARGS:
843 retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
850 case RDS_CMSG_RDMA_DEST:
851 case RDS_CMSG_RDMA_MAP:
853 /* these are valid but do no add any size */
856 case RDS_CMSG_ATOMIC_CSWP:
857 case RDS_CMSG_ATOMIC_FADD:
859 size += sizeof(struct scatterlist);
868 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
870 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
871 if (cmsg_groups == 3)
877 static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
878 struct msghdr *msg, int *allocated_mr)
880 struct cmsghdr *cmsg;
883 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
884 if (!CMSG_OK(msg, cmsg))
887 if (cmsg->cmsg_level != SOL_RDS)
890 /* As a side effect, RDMA_DEST and RDMA_MAP will set
891 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
893 switch (cmsg->cmsg_type) {
894 case RDS_CMSG_RDMA_ARGS:
895 ret = rds_cmsg_rdma_args(rs, rm, cmsg);
898 case RDS_CMSG_RDMA_DEST:
899 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
902 case RDS_CMSG_RDMA_MAP:
903 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
907 case RDS_CMSG_ATOMIC_CSWP:
908 case RDS_CMSG_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 struct sockaddr_in *usin = (struct sockaddr_in *)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)) {
941 printk(KERN_INFO "msg_flags 0x%08X\n", msg->msg_flags);
946 if (msg->msg_namelen) {
947 /* XXX fail non-unicast destination IPs? */
948 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
952 daddr = usin->sin_addr.s_addr;
953 dport = usin->sin_port;
955 /* We only care about consistency with ->connect() */
957 daddr = rs->rs_conn_addr;
958 dport = rs->rs_conn_port;
962 /* racing with another thread binding seems ok here */
963 if (daddr == 0 || rs->rs_bound_addr == 0) {
964 ret = -ENOTCONN; /* XXX not a great errno */
968 /* size of rm including all sgs */
969 ret = rds_rm_size(msg, payload_len);
973 rm = rds_message_alloc(ret, GFP_KERNEL);
979 /* Attach data to the rm */
981 rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
982 ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
986 rm->data.op_active = 1;
990 /* rds_conn_create has a spinlock that runs with IRQ off.
991 * Caching the conn in the socket helps a lot. */
992 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
995 conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
997 sock->sk->sk_allocation);
1005 /* Parse any control messages the user may have included. */
1006 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
1010 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
1011 if (printk_ratelimit())
1012 printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
1013 &rm->rdma, conn->c_trans->xmit_rdma);
1018 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
1019 if (printk_ratelimit())
1020 printk(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
1021 &rm->atomic, conn->c_trans->xmit_atomic);
1026 /* If the connection is down, trigger a connect. We may
1027 * have scheduled a delayed reconnect however - in this case
1028 * we should not interfere.
1030 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
1031 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
1032 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
1034 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
1036 rs->rs_seen_congestion = 1;
1040 while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port,
1042 rds_stats_inc(s_send_queue_full);
1043 /* XXX make sure this is reasonable */
1044 if (payload_len > rds_sk_sndbuf(rs)) {
1053 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
1054 rds_send_queue_rm(rs, conn, rm,
1059 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
1060 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
1070 * By now we've committed to the send. We reuse rds_send_worker()
1071 * to retry sends in the rds thread if the transport asks us to.
1073 rds_stats_inc(s_send_queued);
1075 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1076 rds_send_xmit(conn);
1078 rds_message_put(rm);
1082 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1083 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1084 * or in any other way, we need to destroy the MR again */
1086 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
1089 rds_message_put(rm);
1094 * Reply to a ping packet.
1097 rds_send_pong(struct rds_connection *conn, __be16 dport)
1099 struct rds_message *rm;
1100 unsigned long flags;
1103 rm = rds_message_alloc(0, GFP_ATOMIC);
1109 rm->m_daddr = conn->c_faddr;
1111 /* If the connection is down, trigger a connect. We may
1112 * have scheduled a delayed reconnect however - in this case
1113 * we should not interfere.
1115 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
1116 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
1117 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
1119 ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL);
1123 spin_lock_irqsave(&conn->c_lock, flags);
1124 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
1125 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1126 rds_message_addref(rm);
1127 rm->m_inc.i_conn = conn;
1129 rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport,
1130 conn->c_next_tx_seq);
1131 conn->c_next_tx_seq++;
1132 spin_unlock_irqrestore(&conn->c_lock, flags);
1134 rds_stats_inc(s_send_queued);
1135 rds_stats_inc(s_send_pong);
1137 queue_delayed_work(rds_wq, &conn->c_send_w, 0);
1138 rds_message_put(rm);
1143 rds_message_put(rm);