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 struct scatterlist *sg;
116 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);
138 gen = atomic_inc_return(&conn->c_send_generation);
141 * spin trying to push headers and data down the connection until
142 * the connection doesn't make forward progress.
146 rm = conn->c_xmit_rm;
149 * If between sending messages, we can send a pending congestion
152 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
153 rm = rds_cong_update_alloc(conn);
158 rm->data.op_active = 1;
160 conn->c_xmit_rm = rm;
164 * If not already working on one, grab the next message.
166 * c_xmit_rm holds a ref while we're sending this message down
167 * the connction. We can use this ref while holding the
168 * send_sem.. rds_send_reset() is serialized with it.
173 spin_lock(&conn->c_lock);
175 if (!list_empty(&conn->c_send_queue)) {
176 rm = list_entry(conn->c_send_queue.next,
179 rds_message_addref(rm);
182 * Move the message from the send queue to the retransmit
185 list_move_tail(&rm->m_conn_item, &conn->c_retrans);
188 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);
354 * Other senders will see we have c_send_lock and exit. We
355 * need to recheck the send queue and race again for c_send_lock
356 * to make sure messages don't just sit on the send queue.
358 * If the transport cannot continue (i.e ret != 0), then it must
359 * call us when more room is available, such as from the tx
360 * completion handler.
363 /* A simple bit test would be way faster than taking the
366 if (!list_empty(&conn->c_send_queue)) {
367 rds_stats_inc(s_send_lock_queue_raced);
368 if (gen == atomic_read(&conn->c_send_generation)) {
377 static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
379 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
381 assert_spin_locked(&rs->rs_lock);
383 BUG_ON(rs->rs_snd_bytes < len);
384 rs->rs_snd_bytes -= len;
386 if (rs->rs_snd_bytes == 0)
387 rds_stats_inc(s_send_queue_empty);
390 static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
391 is_acked_func is_acked)
394 return is_acked(rm, ack);
395 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
399 * Returns true if there are no messages on the send and retransmit queues
400 * which have a sequence number greater than or equal to the given sequence
403 int rds_send_acked_before(struct rds_connection *conn, u64 seq)
405 struct rds_message *rm, *tmp;
408 spin_lock(&conn->c_lock);
410 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
411 if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
416 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
417 if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
422 spin_unlock(&conn->c_lock);
428 * This is pretty similar to what happens below in the ACK
429 * handling code - except that we call here as soon as we get
430 * the IB send completion on the RDMA op and the accompanying
433 void rds_rdma_send_complete(struct rds_message *rm, int status)
435 struct rds_sock *rs = NULL;
436 struct rm_rdma_op *ro;
437 struct rds_notifier *notifier;
440 spin_lock_irqsave(&rm->m_rs_lock, flags);
443 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
444 ro->op_active && ro->op_notify && ro->op_notifier) {
445 notifier = ro->op_notifier;
447 sock_hold(rds_rs_to_sk(rs));
449 notifier->n_status = status;
450 spin_lock(&rs->rs_lock);
451 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
452 spin_unlock(&rs->rs_lock);
454 ro->op_notifier = NULL;
457 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
460 rds_wake_sk_sleep(rs);
461 sock_put(rds_rs_to_sk(rs));
464 EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
467 * Just like above, except looks at atomic op
469 void rds_atomic_send_complete(struct rds_message *rm, int status)
471 struct rds_sock *rs = NULL;
472 struct rm_atomic_op *ao;
473 struct rds_notifier *notifier;
476 spin_lock_irqsave(&rm->m_rs_lock, flags);
479 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
480 && ao->op_active && ao->op_notify && ao->op_notifier) {
481 notifier = ao->op_notifier;
483 sock_hold(rds_rs_to_sk(rs));
485 notifier->n_status = status;
486 spin_lock(&rs->rs_lock);
487 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
488 spin_unlock(&rs->rs_lock);
490 ao->op_notifier = NULL;
493 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
496 rds_wake_sk_sleep(rs);
497 sock_put(rds_rs_to_sk(rs));
500 EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
503 * This is the same as rds_rdma_send_complete except we
504 * don't do any locking - we have all the ingredients (message,
505 * socket, socket lock) and can just move the notifier.
508 __rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
510 struct rm_rdma_op *ro;
511 struct rm_atomic_op *ao;
514 if (ro->op_active && ro->op_notify && ro->op_notifier) {
515 ro->op_notifier->n_status = status;
516 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
517 ro->op_notifier = NULL;
521 if (ao->op_active && ao->op_notify && ao->op_notifier) {
522 ao->op_notifier->n_status = status;
523 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
524 ao->op_notifier = NULL;
527 /* No need to wake the app - caller does this */
531 * This is called from the IB send completion when we detect
532 * a RDMA operation that failed with remote access error.
533 * So speed is not an issue here.
535 struct rds_message *rds_send_get_message(struct rds_connection *conn,
536 struct rm_rdma_op *op)
538 struct rds_message *rm, *tmp, *found = NULL;
541 spin_lock_irqsave(&conn->c_lock, flags);
543 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
544 if (&rm->rdma == op) {
545 atomic_inc(&rm->m_refcount);
551 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
552 if (&rm->rdma == op) {
553 atomic_inc(&rm->m_refcount);
560 spin_unlock_irqrestore(&conn->c_lock, flags);
564 EXPORT_SYMBOL_GPL(rds_send_get_message);
567 * This removes messages from the socket's list if they're on it. The list
568 * argument must be private to the caller, we must be able to modify it
569 * without locks. The messages must have a reference held for their
570 * position on the list. This function will drop that reference after
571 * removing the messages from the 'messages' list regardless of if it found
572 * the messages on the socket list or not.
574 void rds_send_remove_from_sock(struct list_head *messages, int status)
577 struct rds_sock *rs = NULL;
578 struct rds_message *rm;
580 while (!list_empty(messages)) {
583 rm = list_entry(messages->next, struct rds_message,
585 list_del_init(&rm->m_conn_item);
588 * If we see this flag cleared then we're *sure* that someone
589 * else beat us to removing it from the sock. If we race
590 * with their flag update we'll get the lock and then really
591 * see that the flag has been cleared.
593 * The message spinlock makes sure nobody clears rm->m_rs
594 * while we're messing with it. It does not prevent the
595 * message from being removed from the socket, though.
597 spin_lock_irqsave(&rm->m_rs_lock, flags);
598 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
599 goto unlock_and_drop;
601 if (rs != rm->m_rs) {
603 rds_wake_sk_sleep(rs);
604 sock_put(rds_rs_to_sk(rs));
607 sock_hold(rds_rs_to_sk(rs));
609 spin_lock(&rs->rs_lock);
611 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
612 struct rm_rdma_op *ro = &rm->rdma;
613 struct rds_notifier *notifier;
615 list_del_init(&rm->m_sock_item);
616 rds_send_sndbuf_remove(rs, rm);
618 if (ro->op_active && ro->op_notifier &&
619 (ro->op_notify || (ro->op_recverr && status))) {
620 notifier = ro->op_notifier;
621 list_add_tail(¬ifier->n_list,
622 &rs->rs_notify_queue);
623 if (!notifier->n_status)
624 notifier->n_status = status;
625 rm->rdma.op_notifier = NULL;
630 spin_unlock(&rs->rs_lock);
633 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
640 rds_wake_sk_sleep(rs);
641 sock_put(rds_rs_to_sk(rs));
646 * Transports call here when they've determined that the receiver queued
647 * messages up to, and including, the given sequence number. Messages are
648 * moved to the retrans queue when rds_send_xmit picks them off the send
649 * queue. This means that in the TCP case, the message may not have been
650 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
651 * checks the RDS_MSG_HAS_ACK_SEQ bit.
653 * XXX It's not clear to me how this is safely serialized with socket
654 * destruction. Maybe it should bail if it sees SOCK_DEAD.
656 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
657 is_acked_func is_acked)
659 struct rds_message *rm, *tmp;
663 spin_lock_irqsave(&conn->c_lock, flags);
665 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
666 if (!rds_send_is_acked(rm, ack, is_acked))
669 list_move(&rm->m_conn_item, &list);
670 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
673 /* order flag updates with spin locks */
674 if (!list_empty(&list))
675 smp_mb__after_clear_bit();
677 spin_unlock_irqrestore(&conn->c_lock, flags);
679 /* now remove the messages from the sock list as needed */
680 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
682 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
684 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
686 struct rds_message *rm, *tmp;
687 struct rds_connection *conn;
691 /* get all the messages we're dropping under the rs lock */
692 spin_lock_irqsave(&rs->rs_lock, flags);
694 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
695 if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
696 dest->sin_port != rm->m_inc.i_hdr.h_dport))
699 list_move(&rm->m_sock_item, &list);
700 rds_send_sndbuf_remove(rs, rm);
701 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
704 /* order flag updates with the rs lock */
705 smp_mb__after_clear_bit();
707 spin_unlock_irqrestore(&rs->rs_lock, flags);
709 if (list_empty(&list))
712 /* Remove the messages from the conn */
713 list_for_each_entry(rm, &list, m_sock_item) {
715 conn = rm->m_inc.i_conn;
717 spin_lock_irqsave(&conn->c_lock, flags);
719 * Maybe someone else beat us to removing rm from the conn.
720 * If we race with their flag update we'll get the lock and
721 * then really see that the flag has been cleared.
723 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
724 spin_unlock_irqrestore(&conn->c_lock, flags);
727 list_del_init(&rm->m_conn_item);
728 spin_unlock_irqrestore(&conn->c_lock, flags);
731 * Couldn't grab m_rs_lock in top loop (lock ordering),
734 spin_lock_irqsave(&rm->m_rs_lock, flags);
736 spin_lock(&rs->rs_lock);
737 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
738 spin_unlock(&rs->rs_lock);
741 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
746 rds_wake_sk_sleep(rs);
748 while (!list_empty(&list)) {
749 rm = list_entry(list.next, struct rds_message, m_sock_item);
750 list_del_init(&rm->m_sock_item);
752 rds_message_wait(rm);
758 * we only want this to fire once so we use the callers 'queued'. It's
759 * possible that another thread can race with us and remove the
760 * message from the flow with RDS_CANCEL_SENT_TO.
762 static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
763 struct rds_message *rm, __be16 sport,
764 __be16 dport, int *queued)
772 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
774 /* this is the only place which holds both the socket's rs_lock
775 * and the connection's c_lock */
776 spin_lock_irqsave(&rs->rs_lock, flags);
779 * If there is a little space in sndbuf, we don't queue anything,
780 * and userspace gets -EAGAIN. But poll() indicates there's send
781 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
782 * freed up by incoming acks. So we check the *old* value of
783 * rs_snd_bytes here to allow the last msg to exceed the buffer,
784 * and poll() now knows no more data can be sent.
786 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
787 rs->rs_snd_bytes += len;
789 /* let recv side know we are close to send space exhaustion.
790 * This is probably not the optimal way to do it, as this
791 * means we set the flag on *all* messages as soon as our
792 * throughput hits a certain threshold.
794 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
795 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
797 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
798 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
799 rds_message_addref(rm);
802 /* The code ordering is a little weird, but we're
803 trying to minimize the time we hold c_lock */
804 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
805 rm->m_inc.i_conn = conn;
806 rds_message_addref(rm);
808 spin_lock(&conn->c_lock);
809 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++);
810 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
811 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
812 spin_unlock(&conn->c_lock);
814 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
815 rm, len, rs, rs->rs_snd_bytes,
816 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
821 spin_unlock_irqrestore(&rs->rs_lock, flags);
827 * rds_message is getting to be quite complicated, and we'd like to allocate
828 * it all in one go. This figures out how big it needs to be up front.
830 static int rds_rm_size(struct msghdr *msg, int data_len)
832 struct cmsghdr *cmsg;
837 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
838 if (!CMSG_OK(msg, cmsg))
841 if (cmsg->cmsg_level != SOL_RDS)
844 switch (cmsg->cmsg_type) {
845 case RDS_CMSG_RDMA_ARGS:
847 retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
854 case RDS_CMSG_RDMA_DEST:
855 case RDS_CMSG_RDMA_MAP:
857 /* these are valid but do no add any size */
860 case RDS_CMSG_ATOMIC_CSWP:
861 case RDS_CMSG_ATOMIC_FADD:
863 size += sizeof(struct scatterlist);
872 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
874 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
875 if (cmsg_groups == 3)
881 static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
882 struct msghdr *msg, int *allocated_mr)
884 struct cmsghdr *cmsg;
887 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
888 if (!CMSG_OK(msg, cmsg))
891 if (cmsg->cmsg_level != SOL_RDS)
894 /* As a side effect, RDMA_DEST and RDMA_MAP will set
895 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
897 switch (cmsg->cmsg_type) {
898 case RDS_CMSG_RDMA_ARGS:
899 ret = rds_cmsg_rdma_args(rs, rm, cmsg);
902 case RDS_CMSG_RDMA_DEST:
903 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
906 case RDS_CMSG_RDMA_MAP:
907 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
911 case RDS_CMSG_ATOMIC_CSWP:
912 case RDS_CMSG_ATOMIC_FADD:
913 ret = rds_cmsg_atomic(rs, rm, cmsg);
927 int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
930 struct sock *sk = sock->sk;
931 struct rds_sock *rs = rds_sk_to_rs(sk);
932 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
935 struct rds_message *rm = NULL;
936 struct rds_connection *conn;
938 int queued = 0, allocated_mr = 0;
939 int nonblock = msg->msg_flags & MSG_DONTWAIT;
940 long timeo = sock_sndtimeo(sk, nonblock);
942 /* Mirror Linux UDP mirror of BSD error message compatibility */
943 /* XXX: Perhaps MSG_MORE someday */
944 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
945 printk(KERN_INFO "msg_flags 0x%08X\n", msg->msg_flags);
950 if (msg->msg_namelen) {
951 /* XXX fail non-unicast destination IPs? */
952 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
956 daddr = usin->sin_addr.s_addr;
957 dport = usin->sin_port;
959 /* We only care about consistency with ->connect() */
961 daddr = rs->rs_conn_addr;
962 dport = rs->rs_conn_port;
966 /* racing with another thread binding seems ok here */
967 if (daddr == 0 || rs->rs_bound_addr == 0) {
968 ret = -ENOTCONN; /* XXX not a great errno */
972 /* size of rm including all sgs */
973 ret = rds_rm_size(msg, payload_len);
977 rm = rds_message_alloc(ret, GFP_KERNEL);
983 /* Attach data to the rm */
985 rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
986 ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
990 rm->data.op_active = 1;
994 /* rds_conn_create has a spinlock that runs with IRQ off.
995 * Caching the conn in the socket helps a lot. */
996 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
999 conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
1001 sock->sk->sk_allocation);
1003 ret = PTR_ERR(conn);
1009 /* Parse any control messages the user may have included. */
1010 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
1014 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
1015 if (printk_ratelimit())
1016 printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
1017 &rm->rdma, conn->c_trans->xmit_rdma);
1022 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
1023 if (printk_ratelimit())
1024 printk(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
1025 &rm->atomic, conn->c_trans->xmit_atomic);
1030 /* If the connection is down, trigger a connect. We may
1031 * have scheduled a delayed reconnect however - in this case
1032 * we should not interfere.
1034 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
1035 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
1036 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
1038 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
1040 rs->rs_seen_congestion = 1;
1044 while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port,
1046 rds_stats_inc(s_send_queue_full);
1047 /* XXX make sure this is reasonable */
1048 if (payload_len > rds_sk_sndbuf(rs)) {
1057 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
1058 rds_send_queue_rm(rs, conn, rm,
1063 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
1064 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
1074 * By now we've committed to the send. We reuse rds_send_worker()
1075 * to retry sends in the rds thread if the transport asks us to.
1077 rds_stats_inc(s_send_queued);
1079 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1080 rds_send_xmit(conn);
1082 rds_message_put(rm);
1086 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1087 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1088 * or in any other way, we need to destroy the MR again */
1090 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
1093 rds_message_put(rm);
1098 * Reply to a ping packet.
1101 rds_send_pong(struct rds_connection *conn, __be16 dport)
1103 struct rds_message *rm;
1104 unsigned long flags;
1107 rm = rds_message_alloc(0, GFP_ATOMIC);
1113 rm->m_daddr = conn->c_faddr;
1114 rm->data.op_active = 1;
1116 /* If the connection is down, trigger a connect. We may
1117 * have scheduled a delayed reconnect however - in this case
1118 * we should not interfere.
1120 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
1121 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
1122 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
1124 ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL);
1128 spin_lock_irqsave(&conn->c_lock, flags);
1129 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
1130 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1131 rds_message_addref(rm);
1132 rm->m_inc.i_conn = conn;
1134 rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport,
1135 conn->c_next_tx_seq);
1136 conn->c_next_tx_seq++;
1137 spin_unlock_irqrestore(&conn->c_lock, flags);
1139 rds_stats_inc(s_send_queued);
1140 rds_stats_inc(s_send_pong);
1142 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1143 rds_send_xmit(conn);
1145 rds_message_put(rm);
1150 rds_message_put(rm);