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. Callers must ensure that this doesn't race with
59 void rds_send_reset(struct rds_connection *conn)
61 struct rds_message *rm, *tmp;
64 if (conn->c_xmit_rm) {
66 conn->c_xmit_rm = NULL;
67 /* Tell the user the RDMA op is no longer mapped by the
68 * transport. This isn't entirely true (it's flushed out
69 * independently) but as the connection is down, there's
70 * no ongoing RDMA to/from that memory */
71 rds_message_unmapped(rm);
76 conn->c_xmit_hdr_off = 0;
77 conn->c_xmit_data_off = 0;
78 conn->c_xmit_atomic_sent = 0;
79 conn->c_xmit_rdma_sent = 0;
80 conn->c_xmit_data_sent = 0;
82 conn->c_map_queued = 0;
84 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
85 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
87 /* Mark messages as retransmissions, and move them to the send q */
88 spin_lock_irqsave(&conn->c_lock, flags);
89 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
90 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
91 set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
93 list_splice_init(&conn->c_retrans, &conn->c_send_queue);
94 spin_unlock_irqrestore(&conn->c_lock, flags);
97 static int acquire_in_xmit(struct rds_connection *conn)
99 return test_and_set_bit(RDS_IN_XMIT, &conn->c_flags) == 0;
102 static void release_in_xmit(struct rds_connection *conn)
104 clear_bit(RDS_IN_XMIT, &conn->c_flags);
105 smp_mb__after_clear_bit();
107 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
108 * hot path and finding waiters is very rare. We don't want to walk
109 * the system-wide hashed waitqueue buckets in the fast path only to
110 * almost never find waiters.
112 if (waitqueue_active(&conn->c_waitq))
113 wake_up_all(&conn->c_waitq);
117 * We're making the concious trade-off here to only send one message
118 * down the connection at a time.
120 * - tx queueing is a simple fifo list
121 * - reassembly is optional and easily done by transports per conn
122 * - no per flow rx lookup at all, straight to the socket
123 * - less per-frag memory and wire overhead
125 * - queued acks can be delayed behind large messages
127 * - small message latency is higher behind queued large messages
128 * - large message latency isn't starved by intervening small sends
130 int rds_send_xmit(struct rds_connection *conn)
132 struct rds_message *rm;
135 struct scatterlist *sg;
137 LIST_HEAD(to_be_dropped);
142 * sendmsg calls here after having queued its message on the send
143 * queue. We only have one task feeding the connection at a time. If
144 * another thread is already feeding the queue then we back off. This
145 * avoids blocking the caller and trading per-connection data between
146 * caches per message.
148 if (!acquire_in_xmit(conn)) {
149 rds_stats_inc(s_send_lock_contention);
155 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
156 * we do the opposite to avoid races.
158 if (!rds_conn_up(conn)) {
159 release_in_xmit(conn);
164 if (conn->c_trans->xmit_prepare)
165 conn->c_trans->xmit_prepare(conn);
168 * spin trying to push headers and data down the connection until
169 * the connection doesn't make forward progress.
173 rm = conn->c_xmit_rm;
176 * If between sending messages, we can send a pending congestion
179 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
180 rm = rds_cong_update_alloc(conn);
185 rm->data.op_active = 1;
187 conn->c_xmit_rm = rm;
191 * If not already working on one, grab the next message.
193 * c_xmit_rm holds a ref while we're sending this message down
194 * the connction. We can use this ref while holding the
195 * send_sem.. rds_send_reset() is serialized with it.
200 spin_lock_irqsave(&conn->c_lock, flags);
202 if (!list_empty(&conn->c_send_queue)) {
203 rm = list_entry(conn->c_send_queue.next,
206 rds_message_addref(rm);
209 * Move the message from the send queue to the retransmit
212 list_move_tail(&rm->m_conn_item, &conn->c_retrans);
215 spin_unlock_irqrestore(&conn->c_lock, flags);
220 /* Unfortunately, the way Infiniband deals with
221 * RDMA to a bad MR key is by moving the entire
222 * queue pair to error state. We cold possibly
223 * recover from that, but right now we drop the
225 * Therefore, we never retransmit messages with RDMA ops.
227 if (rm->rdma.op_active &&
228 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
229 spin_lock_irqsave(&conn->c_lock, flags);
230 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
231 list_move(&rm->m_conn_item, &to_be_dropped);
232 spin_unlock_irqrestore(&conn->c_lock, flags);
236 /* Require an ACK every once in a while */
237 len = ntohl(rm->m_inc.i_hdr.h_len);
238 if (conn->c_unacked_packets == 0 ||
239 conn->c_unacked_bytes < len) {
240 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
242 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
243 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
244 rds_stats_inc(s_send_ack_required);
246 conn->c_unacked_bytes -= len;
247 conn->c_unacked_packets--;
250 conn->c_xmit_rm = rm;
253 /* The transport either sends the whole rdma or none of it */
254 if (rm->rdma.op_active && !conn->c_xmit_rdma_sent) {
255 rm->m_final_op = &rm->rdma;
256 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma);
259 conn->c_xmit_rdma_sent = 1;
261 /* The transport owns the mapped memory for now.
262 * You can't unmap it while it's on the send queue */
263 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
266 if (rm->atomic.op_active && !conn->c_xmit_atomic_sent) {
267 rm->m_final_op = &rm->atomic;
268 ret = conn->c_trans->xmit_atomic(conn, &rm->atomic);
271 conn->c_xmit_atomic_sent = 1;
273 /* The transport owns the mapped memory for now.
274 * You can't unmap it while it's on the send queue */
275 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
279 * A number of cases require an RDS header to be sent
280 * even if there is no data.
281 * We permit 0-byte sends; rds-ping depends on this.
282 * However, if there are exclusively attached silent ops,
283 * we skip the hdr/data send, to enable silent operation.
285 if (rm->data.op_nents == 0) {
287 int all_ops_are_silent = 1;
289 ops_present = (rm->atomic.op_active || rm->rdma.op_active);
290 if (rm->atomic.op_active && !rm->atomic.op_silent)
291 all_ops_are_silent = 0;
292 if (rm->rdma.op_active && !rm->rdma.op_silent)
293 all_ops_are_silent = 0;
295 if (ops_present && all_ops_are_silent
296 && !rm->m_rdma_cookie)
297 rm->data.op_active = 0;
300 if (rm->data.op_active && !conn->c_xmit_data_sent) {
301 rm->m_final_op = &rm->data;
302 ret = conn->c_trans->xmit(conn, rm,
303 conn->c_xmit_hdr_off,
305 conn->c_xmit_data_off);
309 if (conn->c_xmit_hdr_off < sizeof(struct rds_header)) {
310 tmp = min_t(int, ret,
311 sizeof(struct rds_header) -
312 conn->c_xmit_hdr_off);
313 conn->c_xmit_hdr_off += tmp;
317 sg = &rm->data.op_sg[conn->c_xmit_sg];
319 tmp = min_t(int, ret, sg->length -
320 conn->c_xmit_data_off);
321 conn->c_xmit_data_off += tmp;
323 if (conn->c_xmit_data_off == sg->length) {
324 conn->c_xmit_data_off = 0;
328 conn->c_xmit_sg == rm->data.op_nents);
332 if (conn->c_xmit_hdr_off == sizeof(struct rds_header) &&
333 (conn->c_xmit_sg == rm->data.op_nents))
334 conn->c_xmit_data_sent = 1;
338 * A rm will only take multiple times through this loop
339 * if there is a data op. Thus, if the data is sent (or there was
340 * none), then we're done with the rm.
342 if (!rm->data.op_active || conn->c_xmit_data_sent) {
343 conn->c_xmit_rm = NULL;
345 conn->c_xmit_hdr_off = 0;
346 conn->c_xmit_data_off = 0;
347 conn->c_xmit_rdma_sent = 0;
348 conn->c_xmit_atomic_sent = 0;
349 conn->c_xmit_data_sent = 0;
355 if (conn->c_trans->xmit_complete)
356 conn->c_trans->xmit_complete(conn);
358 release_in_xmit(conn);
360 /* Nuke any messages we decided not to retransmit. */
361 if (!list_empty(&to_be_dropped)) {
362 /* irqs on here, so we can put(), unlike above */
363 list_for_each_entry(rm, &to_be_dropped, m_conn_item)
365 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
369 * Other senders can queue a message after we last test the send queue
370 * but before we clear RDS_IN_XMIT. In that case they'd back off and
371 * not try and send their newly queued message. We need to check the
372 * send queue after having cleared RDS_IN_XMIT so that their message
373 * doesn't get stuck on the send queue.
375 * If the transport cannot continue (i.e ret != 0), then it must
376 * call us when more room is available, such as from the tx
377 * completion handler.
381 if (!list_empty(&conn->c_send_queue)) {
382 rds_stats_inc(s_send_lock_queue_raced);
390 static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
392 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
394 assert_spin_locked(&rs->rs_lock);
396 BUG_ON(rs->rs_snd_bytes < len);
397 rs->rs_snd_bytes -= len;
399 if (rs->rs_snd_bytes == 0)
400 rds_stats_inc(s_send_queue_empty);
403 static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
404 is_acked_func is_acked)
407 return is_acked(rm, ack);
408 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
412 * This is pretty similar to what happens below in the ACK
413 * handling code - except that we call here as soon as we get
414 * the IB send completion on the RDMA op and the accompanying
417 void rds_rdma_send_complete(struct rds_message *rm, int status)
419 struct rds_sock *rs = NULL;
420 struct rm_rdma_op *ro;
421 struct rds_notifier *notifier;
424 spin_lock_irqsave(&rm->m_rs_lock, flags);
427 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
428 ro->op_active && ro->op_notify && ro->op_notifier) {
429 notifier = ro->op_notifier;
431 sock_hold(rds_rs_to_sk(rs));
433 notifier->n_status = status;
434 spin_lock(&rs->rs_lock);
435 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
436 spin_unlock(&rs->rs_lock);
438 ro->op_notifier = NULL;
441 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
444 rds_wake_sk_sleep(rs);
445 sock_put(rds_rs_to_sk(rs));
448 EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
451 * Just like above, except looks at atomic op
453 void rds_atomic_send_complete(struct rds_message *rm, int status)
455 struct rds_sock *rs = NULL;
456 struct rm_atomic_op *ao;
457 struct rds_notifier *notifier;
460 spin_lock_irqsave(&rm->m_rs_lock, flags);
463 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
464 && ao->op_active && ao->op_notify && ao->op_notifier) {
465 notifier = ao->op_notifier;
467 sock_hold(rds_rs_to_sk(rs));
469 notifier->n_status = status;
470 spin_lock(&rs->rs_lock);
471 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
472 spin_unlock(&rs->rs_lock);
474 ao->op_notifier = NULL;
477 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
480 rds_wake_sk_sleep(rs);
481 sock_put(rds_rs_to_sk(rs));
484 EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
487 * This is the same as rds_rdma_send_complete except we
488 * don't do any locking - we have all the ingredients (message,
489 * socket, socket lock) and can just move the notifier.
492 __rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
494 struct rm_rdma_op *ro;
495 struct rm_atomic_op *ao;
498 if (ro->op_active && ro->op_notify && ro->op_notifier) {
499 ro->op_notifier->n_status = status;
500 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
501 ro->op_notifier = NULL;
505 if (ao->op_active && ao->op_notify && ao->op_notifier) {
506 ao->op_notifier->n_status = status;
507 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
508 ao->op_notifier = NULL;
511 /* No need to wake the app - caller does this */
515 * This is called from the IB send completion when we detect
516 * a RDMA operation that failed with remote access error.
517 * So speed is not an issue here.
519 struct rds_message *rds_send_get_message(struct rds_connection *conn,
520 struct rm_rdma_op *op)
522 struct rds_message *rm, *tmp, *found = NULL;
525 spin_lock_irqsave(&conn->c_lock, flags);
527 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
528 if (&rm->rdma == op) {
529 atomic_inc(&rm->m_refcount);
535 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
536 if (&rm->rdma == op) {
537 atomic_inc(&rm->m_refcount);
544 spin_unlock_irqrestore(&conn->c_lock, flags);
548 EXPORT_SYMBOL_GPL(rds_send_get_message);
551 * This removes messages from the socket's list if they're on it. The list
552 * argument must be private to the caller, we must be able to modify it
553 * without locks. The messages must have a reference held for their
554 * position on the list. This function will drop that reference after
555 * removing the messages from the 'messages' list regardless of if it found
556 * the messages on the socket list or not.
558 void rds_send_remove_from_sock(struct list_head *messages, int status)
561 struct rds_sock *rs = NULL;
562 struct rds_message *rm;
564 while (!list_empty(messages)) {
567 rm = list_entry(messages->next, struct rds_message,
569 list_del_init(&rm->m_conn_item);
572 * If we see this flag cleared then we're *sure* that someone
573 * else beat us to removing it from the sock. If we race
574 * with their flag update we'll get the lock and then really
575 * see that the flag has been cleared.
577 * The message spinlock makes sure nobody clears rm->m_rs
578 * while we're messing with it. It does not prevent the
579 * message from being removed from the socket, though.
581 spin_lock_irqsave(&rm->m_rs_lock, flags);
582 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
583 goto unlock_and_drop;
585 if (rs != rm->m_rs) {
587 rds_wake_sk_sleep(rs);
588 sock_put(rds_rs_to_sk(rs));
591 sock_hold(rds_rs_to_sk(rs));
593 spin_lock(&rs->rs_lock);
595 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
596 struct rm_rdma_op *ro = &rm->rdma;
597 struct rds_notifier *notifier;
599 list_del_init(&rm->m_sock_item);
600 rds_send_sndbuf_remove(rs, rm);
602 if (ro->op_active && ro->op_notifier &&
603 (ro->op_notify || (ro->op_recverr && status))) {
604 notifier = ro->op_notifier;
605 list_add_tail(¬ifier->n_list,
606 &rs->rs_notify_queue);
607 if (!notifier->n_status)
608 notifier->n_status = status;
609 rm->rdma.op_notifier = NULL;
614 spin_unlock(&rs->rs_lock);
617 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
624 rds_wake_sk_sleep(rs);
625 sock_put(rds_rs_to_sk(rs));
630 * Transports call here when they've determined that the receiver queued
631 * messages up to, and including, the given sequence number. Messages are
632 * moved to the retrans queue when rds_send_xmit picks them off the send
633 * queue. This means that in the TCP case, the message may not have been
634 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
635 * checks the RDS_MSG_HAS_ACK_SEQ bit.
637 * XXX It's not clear to me how this is safely serialized with socket
638 * destruction. Maybe it should bail if it sees SOCK_DEAD.
640 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
641 is_acked_func is_acked)
643 struct rds_message *rm, *tmp;
647 spin_lock_irqsave(&conn->c_lock, flags);
649 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
650 if (!rds_send_is_acked(rm, ack, is_acked))
653 list_move(&rm->m_conn_item, &list);
654 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
657 /* order flag updates with spin locks */
658 if (!list_empty(&list))
659 smp_mb__after_clear_bit();
661 spin_unlock_irqrestore(&conn->c_lock, flags);
663 /* now remove the messages from the sock list as needed */
664 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
666 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
668 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
670 struct rds_message *rm, *tmp;
671 struct rds_connection *conn;
675 /* get all the messages we're dropping under the rs lock */
676 spin_lock_irqsave(&rs->rs_lock, flags);
678 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
679 if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
680 dest->sin_port != rm->m_inc.i_hdr.h_dport))
683 list_move(&rm->m_sock_item, &list);
684 rds_send_sndbuf_remove(rs, rm);
685 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
688 /* order flag updates with the rs lock */
689 smp_mb__after_clear_bit();
691 spin_unlock_irqrestore(&rs->rs_lock, flags);
693 if (list_empty(&list))
696 /* Remove the messages from the conn */
697 list_for_each_entry(rm, &list, m_sock_item) {
699 conn = rm->m_inc.i_conn;
701 spin_lock_irqsave(&conn->c_lock, flags);
703 * Maybe someone else beat us to removing rm from the conn.
704 * If we race with their flag update we'll get the lock and
705 * then really see that the flag has been cleared.
707 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
708 spin_unlock_irqrestore(&conn->c_lock, flags);
711 list_del_init(&rm->m_conn_item);
712 spin_unlock_irqrestore(&conn->c_lock, flags);
715 * Couldn't grab m_rs_lock in top loop (lock ordering),
718 spin_lock_irqsave(&rm->m_rs_lock, flags);
720 spin_lock(&rs->rs_lock);
721 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
722 spin_unlock(&rs->rs_lock);
725 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
730 rds_wake_sk_sleep(rs);
732 while (!list_empty(&list)) {
733 rm = list_entry(list.next, struct rds_message, m_sock_item);
734 list_del_init(&rm->m_sock_item);
736 rds_message_wait(rm);
742 * we only want this to fire once so we use the callers 'queued'. It's
743 * possible that another thread can race with us and remove the
744 * message from the flow with RDS_CANCEL_SENT_TO.
746 static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
747 struct rds_message *rm, __be16 sport,
748 __be16 dport, int *queued)
756 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
758 /* this is the only place which holds both the socket's rs_lock
759 * and the connection's c_lock */
760 spin_lock_irqsave(&rs->rs_lock, flags);
763 * If there is a little space in sndbuf, we don't queue anything,
764 * and userspace gets -EAGAIN. But poll() indicates there's send
765 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
766 * freed up by incoming acks. So we check the *old* value of
767 * rs_snd_bytes here to allow the last msg to exceed the buffer,
768 * and poll() now knows no more data can be sent.
770 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
771 rs->rs_snd_bytes += len;
773 /* let recv side know we are close to send space exhaustion.
774 * This is probably not the optimal way to do it, as this
775 * means we set the flag on *all* messages as soon as our
776 * throughput hits a certain threshold.
778 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
779 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
781 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
782 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
783 rds_message_addref(rm);
786 /* The code ordering is a little weird, but we're
787 trying to minimize the time we hold c_lock */
788 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
789 rm->m_inc.i_conn = conn;
790 rds_message_addref(rm);
792 spin_lock(&conn->c_lock);
793 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++);
794 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
795 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
796 spin_unlock(&conn->c_lock);
798 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
799 rm, len, rs, rs->rs_snd_bytes,
800 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
805 spin_unlock_irqrestore(&rs->rs_lock, flags);
811 * rds_message is getting to be quite complicated, and we'd like to allocate
812 * it all in one go. This figures out how big it needs to be up front.
814 static int rds_rm_size(struct msghdr *msg, int data_len)
816 struct cmsghdr *cmsg;
821 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
822 if (!CMSG_OK(msg, cmsg))
825 if (cmsg->cmsg_level != SOL_RDS)
828 switch (cmsg->cmsg_type) {
829 case RDS_CMSG_RDMA_ARGS:
831 retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
838 case RDS_CMSG_RDMA_DEST:
839 case RDS_CMSG_RDMA_MAP:
841 /* these are valid but do no add any size */
844 case RDS_CMSG_ATOMIC_CSWP:
845 case RDS_CMSG_ATOMIC_FADD:
846 case RDS_CMSG_MASKED_ATOMIC_CSWP:
847 case RDS_CMSG_MASKED_ATOMIC_FADD:
849 size += sizeof(struct scatterlist);
858 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
860 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
861 if (cmsg_groups == 3)
867 static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
868 struct msghdr *msg, int *allocated_mr)
870 struct cmsghdr *cmsg;
873 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
874 if (!CMSG_OK(msg, cmsg))
877 if (cmsg->cmsg_level != SOL_RDS)
880 /* As a side effect, RDMA_DEST and RDMA_MAP will set
881 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
883 switch (cmsg->cmsg_type) {
884 case RDS_CMSG_RDMA_ARGS:
885 ret = rds_cmsg_rdma_args(rs, rm, cmsg);
888 case RDS_CMSG_RDMA_DEST:
889 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
892 case RDS_CMSG_RDMA_MAP:
893 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
897 case RDS_CMSG_ATOMIC_CSWP:
898 case RDS_CMSG_ATOMIC_FADD:
899 case RDS_CMSG_MASKED_ATOMIC_CSWP:
900 case RDS_CMSG_MASKED_ATOMIC_FADD:
901 ret = rds_cmsg_atomic(rs, rm, cmsg);
915 int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
918 struct sock *sk = sock->sk;
919 struct rds_sock *rs = rds_sk_to_rs(sk);
920 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
923 struct rds_message *rm = NULL;
924 struct rds_connection *conn;
926 int queued = 0, allocated_mr = 0;
927 int nonblock = msg->msg_flags & MSG_DONTWAIT;
928 long timeo = sock_sndtimeo(sk, nonblock);
930 /* Mirror Linux UDP mirror of BSD error message compatibility */
931 /* XXX: Perhaps MSG_MORE someday */
932 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
933 printk(KERN_INFO "msg_flags 0x%08X\n", msg->msg_flags);
938 if (msg->msg_namelen) {
939 /* XXX fail non-unicast destination IPs? */
940 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
944 daddr = usin->sin_addr.s_addr;
945 dport = usin->sin_port;
947 /* We only care about consistency with ->connect() */
949 daddr = rs->rs_conn_addr;
950 dport = rs->rs_conn_port;
954 /* racing with another thread binding seems ok here */
955 if (daddr == 0 || rs->rs_bound_addr == 0) {
956 ret = -ENOTCONN; /* XXX not a great errno */
960 /* size of rm including all sgs */
961 ret = rds_rm_size(msg, payload_len);
965 rm = rds_message_alloc(ret, GFP_KERNEL);
971 /* Attach data to the rm */
973 rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
974 ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
978 rm->data.op_active = 1;
982 /* rds_conn_create has a spinlock that runs with IRQ off.
983 * Caching the conn in the socket helps a lot. */
984 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
987 conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
989 sock->sk->sk_allocation);
997 /* Parse any control messages the user may have included. */
998 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
1002 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
1003 if (printk_ratelimit())
1004 printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
1005 &rm->rdma, conn->c_trans->xmit_rdma);
1010 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
1011 if (printk_ratelimit())
1012 printk(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
1013 &rm->atomic, conn->c_trans->xmit_atomic);
1018 rds_conn_connect_if_down(conn);
1020 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
1022 rs->rs_seen_congestion = 1;
1026 while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port,
1028 rds_stats_inc(s_send_queue_full);
1029 /* XXX make sure this is reasonable */
1030 if (payload_len > rds_sk_sndbuf(rs)) {
1039 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
1040 rds_send_queue_rm(rs, conn, rm,
1045 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
1046 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
1056 * By now we've committed to the send. We reuse rds_send_worker()
1057 * to retry sends in the rds thread if the transport asks us to.
1059 rds_stats_inc(s_send_queued);
1061 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1062 rds_send_xmit(conn);
1064 rds_message_put(rm);
1068 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1069 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1070 * or in any other way, we need to destroy the MR again */
1072 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
1075 rds_message_put(rm);
1080 * Reply to a ping packet.
1083 rds_send_pong(struct rds_connection *conn, __be16 dport)
1085 struct rds_message *rm;
1086 unsigned long flags;
1089 rm = rds_message_alloc(0, GFP_ATOMIC);
1095 rm->m_daddr = conn->c_faddr;
1096 rm->data.op_active = 1;
1098 rds_conn_connect_if_down(conn);
1100 ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL);
1104 spin_lock_irqsave(&conn->c_lock, flags);
1105 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
1106 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1107 rds_message_addref(rm);
1108 rm->m_inc.i_conn = conn;
1110 rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport,
1111 conn->c_next_tx_seq);
1112 conn->c_next_tx_seq++;
1113 spin_unlock_irqrestore(&conn->c_lock, flags);
1115 rds_stats_inc(s_send_queued);
1116 rds_stats_inc(s_send_pong);
1118 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1119 rds_send_xmit(conn);
1121 rds_message_put(rm);
1126 rds_message_put(rm);