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>
44 /* When transmitting messages in rds_send_xmit, we need to emerge from
45 * time to time and briefly release the CPU. Otherwise the softlock watchdog
47 * Also, it seems fairer to not let one busy connection stall all the
50 * send_batch_count is the number of times we'll loop in send_xmit. Setting
51 * it to 0 will restore the old behavior (where we looped until we had
54 static int send_batch_count = 64;
55 module_param(send_batch_count, int, 0444);
56 MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
58 static void rds_send_remove_from_sock(struct list_head *messages, int status);
61 * Reset the send state. Callers must ensure that this doesn't race with
64 void rds_send_reset(struct rds_connection *conn)
66 struct rds_message *rm, *tmp;
69 if (conn->c_xmit_rm) {
71 conn->c_xmit_rm = NULL;
72 /* Tell the user the RDMA op is no longer mapped by the
73 * transport. This isn't entirely true (it's flushed out
74 * independently) but as the connection is down, there's
75 * no ongoing RDMA to/from that memory */
76 rds_message_unmapped(rm);
81 conn->c_xmit_hdr_off = 0;
82 conn->c_xmit_data_off = 0;
83 conn->c_xmit_atomic_sent = 0;
84 conn->c_xmit_rdma_sent = 0;
85 conn->c_xmit_data_sent = 0;
87 conn->c_map_queued = 0;
89 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
90 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
92 /* Mark messages as retransmissions, and move them to the send q */
93 spin_lock_irqsave(&conn->c_lock, flags);
94 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
95 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
96 set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
98 list_splice_init(&conn->c_retrans, &conn->c_send_queue);
99 spin_unlock_irqrestore(&conn->c_lock, flags);
102 static int acquire_in_xmit(struct rds_connection *conn)
104 return test_and_set_bit(RDS_IN_XMIT, &conn->c_flags) == 0;
107 static void release_in_xmit(struct rds_connection *conn)
109 clear_bit(RDS_IN_XMIT, &conn->c_flags);
110 smp_mb__after_atomic();
112 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
113 * hot path and finding waiters is very rare. We don't want to walk
114 * the system-wide hashed waitqueue buckets in the fast path only to
115 * almost never find waiters.
117 if (waitqueue_active(&conn->c_waitq))
118 wake_up_all(&conn->c_waitq);
122 * We're making the conscious trade-off here to only send one message
123 * down the connection at a time.
125 * - tx queueing is a simple fifo list
126 * - reassembly is optional and easily done by transports per conn
127 * - no per flow rx lookup at all, straight to the socket
128 * - less per-frag memory and wire overhead
130 * - queued acks can be delayed behind large messages
132 * - small message latency is higher behind queued large messages
133 * - large message latency isn't starved by intervening small sends
135 int rds_send_xmit(struct rds_connection *conn)
137 struct rds_message *rm;
140 struct scatterlist *sg;
142 LIST_HEAD(to_be_dropped);
144 unsigned long send_gen = 0;
150 * sendmsg calls here after having queued its message on the send
151 * queue. We only have one task feeding the connection at a time. If
152 * another thread is already feeding the queue then we back off. This
153 * avoids blocking the caller and trading per-connection data between
154 * caches per message.
156 if (!acquire_in_xmit(conn)) {
157 rds_stats_inc(s_send_lock_contention);
163 * we record the send generation after doing the xmit acquire.
164 * if someone else manages to jump in and do some work, we'll use
165 * this to avoid a goto restart farther down.
167 * The acquire_in_xmit() check above ensures that only one
168 * caller can increment c_send_gen at any time.
171 send_gen = conn->c_send_gen;
174 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
175 * we do the opposite to avoid races.
177 if (!rds_conn_up(conn)) {
178 release_in_xmit(conn);
183 if (conn->c_trans->xmit_prepare)
184 conn->c_trans->xmit_prepare(conn);
187 * spin trying to push headers and data down the connection until
188 * the connection doesn't make forward progress.
192 rm = conn->c_xmit_rm;
195 * If between sending messages, we can send a pending congestion
198 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
199 rm = rds_cong_update_alloc(conn);
204 rm->data.op_active = 1;
206 conn->c_xmit_rm = rm;
210 * If not already working on one, grab the next message.
212 * c_xmit_rm holds a ref while we're sending this message down
213 * the connction. We can use this ref while holding the
214 * send_sem.. rds_send_reset() is serialized with it.
221 /* we want to process as big a batch as we can, but
222 * we also want to avoid softlockups. If we've been
223 * through a lot of messages, lets back off and see
224 * if anyone else jumps in
226 if (batch_count >= 1024)
229 spin_lock_irqsave(&conn->c_lock, flags);
231 if (!list_empty(&conn->c_send_queue)) {
232 rm = list_entry(conn->c_send_queue.next,
235 rds_message_addref(rm);
238 * Move the message from the send queue to the retransmit
241 list_move_tail(&rm->m_conn_item, &conn->c_retrans);
244 spin_unlock_irqrestore(&conn->c_lock, flags);
249 /* Unfortunately, the way Infiniband deals with
250 * RDMA to a bad MR key is by moving the entire
251 * queue pair to error state. We cold possibly
252 * recover from that, but right now we drop the
254 * Therefore, we never retransmit messages with RDMA ops.
256 if (rm->rdma.op_active &&
257 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
258 spin_lock_irqsave(&conn->c_lock, flags);
259 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
260 list_move(&rm->m_conn_item, &to_be_dropped);
261 spin_unlock_irqrestore(&conn->c_lock, flags);
265 /* Require an ACK every once in a while */
266 len = ntohl(rm->m_inc.i_hdr.h_len);
267 if (conn->c_unacked_packets == 0 ||
268 conn->c_unacked_bytes < len) {
269 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
271 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
272 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
273 rds_stats_inc(s_send_ack_required);
275 conn->c_unacked_bytes -= len;
276 conn->c_unacked_packets--;
279 conn->c_xmit_rm = rm;
282 /* The transport either sends the whole rdma or none of it */
283 if (rm->rdma.op_active && !conn->c_xmit_rdma_sent) {
284 rm->m_final_op = &rm->rdma;
285 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma);
288 conn->c_xmit_rdma_sent = 1;
290 /* The transport owns the mapped memory for now.
291 * You can't unmap it while it's on the send queue */
292 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
295 if (rm->atomic.op_active && !conn->c_xmit_atomic_sent) {
296 rm->m_final_op = &rm->atomic;
297 ret = conn->c_trans->xmit_atomic(conn, &rm->atomic);
300 conn->c_xmit_atomic_sent = 1;
302 /* The transport owns the mapped memory for now.
303 * You can't unmap it while it's on the send queue */
304 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
308 * A number of cases require an RDS header to be sent
309 * even if there is no data.
310 * We permit 0-byte sends; rds-ping depends on this.
311 * However, if there are exclusively attached silent ops,
312 * we skip the hdr/data send, to enable silent operation.
314 if (rm->data.op_nents == 0) {
316 int all_ops_are_silent = 1;
318 ops_present = (rm->atomic.op_active || rm->rdma.op_active);
319 if (rm->atomic.op_active && !rm->atomic.op_silent)
320 all_ops_are_silent = 0;
321 if (rm->rdma.op_active && !rm->rdma.op_silent)
322 all_ops_are_silent = 0;
324 if (ops_present && all_ops_are_silent
325 && !rm->m_rdma_cookie)
326 rm->data.op_active = 0;
329 if (rm->data.op_active && !conn->c_xmit_data_sent) {
330 rm->m_final_op = &rm->data;
331 ret = conn->c_trans->xmit(conn, rm,
332 conn->c_xmit_hdr_off,
334 conn->c_xmit_data_off);
338 if (conn->c_xmit_hdr_off < sizeof(struct rds_header)) {
339 tmp = min_t(int, ret,
340 sizeof(struct rds_header) -
341 conn->c_xmit_hdr_off);
342 conn->c_xmit_hdr_off += tmp;
346 sg = &rm->data.op_sg[conn->c_xmit_sg];
348 tmp = min_t(int, ret, sg->length -
349 conn->c_xmit_data_off);
350 conn->c_xmit_data_off += tmp;
352 if (conn->c_xmit_data_off == sg->length) {
353 conn->c_xmit_data_off = 0;
357 conn->c_xmit_sg == rm->data.op_nents);
361 if (conn->c_xmit_hdr_off == sizeof(struct rds_header) &&
362 (conn->c_xmit_sg == rm->data.op_nents))
363 conn->c_xmit_data_sent = 1;
367 * A rm will only take multiple times through this loop
368 * if there is a data op. Thus, if the data is sent (or there was
369 * none), then we're done with the rm.
371 if (!rm->data.op_active || conn->c_xmit_data_sent) {
372 conn->c_xmit_rm = NULL;
374 conn->c_xmit_hdr_off = 0;
375 conn->c_xmit_data_off = 0;
376 conn->c_xmit_rdma_sent = 0;
377 conn->c_xmit_atomic_sent = 0;
378 conn->c_xmit_data_sent = 0;
385 if (conn->c_trans->xmit_complete)
386 conn->c_trans->xmit_complete(conn);
387 release_in_xmit(conn);
389 /* Nuke any messages we decided not to retransmit. */
390 if (!list_empty(&to_be_dropped)) {
391 /* irqs on here, so we can put(), unlike above */
392 list_for_each_entry(rm, &to_be_dropped, m_conn_item)
394 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
398 * Other senders can queue a message after we last test the send queue
399 * but before we clear RDS_IN_XMIT. In that case they'd back off and
400 * not try and send their newly queued message. We need to check the
401 * send queue after having cleared RDS_IN_XMIT so that their message
402 * doesn't get stuck on the send queue.
404 * If the transport cannot continue (i.e ret != 0), then it must
405 * call us when more room is available, such as from the tx
406 * completion handler.
408 * We have an extra generation check here so that if someone manages
409 * to jump in after our release_in_xmit, we'll see that they have done
410 * some work and we will skip our goto
414 if (!list_empty(&conn->c_send_queue) &&
415 send_gen == conn->c_send_gen) {
416 rds_stats_inc(s_send_lock_queue_raced);
424 static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
426 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
428 assert_spin_locked(&rs->rs_lock);
430 BUG_ON(rs->rs_snd_bytes < len);
431 rs->rs_snd_bytes -= len;
433 if (rs->rs_snd_bytes == 0)
434 rds_stats_inc(s_send_queue_empty);
437 static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
438 is_acked_func is_acked)
441 return is_acked(rm, ack);
442 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
446 * This is pretty similar to what happens below in the ACK
447 * handling code - except that we call here as soon as we get
448 * the IB send completion on the RDMA op and the accompanying
451 void rds_rdma_send_complete(struct rds_message *rm, int status)
453 struct rds_sock *rs = NULL;
454 struct rm_rdma_op *ro;
455 struct rds_notifier *notifier;
458 spin_lock_irqsave(&rm->m_rs_lock, flags);
461 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
462 ro->op_active && ro->op_notify && ro->op_notifier) {
463 notifier = ro->op_notifier;
465 sock_hold(rds_rs_to_sk(rs));
467 notifier->n_status = status;
468 spin_lock(&rs->rs_lock);
469 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
470 spin_unlock(&rs->rs_lock);
472 ro->op_notifier = NULL;
475 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
478 rds_wake_sk_sleep(rs);
479 sock_put(rds_rs_to_sk(rs));
482 EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
485 * Just like above, except looks at atomic op
487 void rds_atomic_send_complete(struct rds_message *rm, int status)
489 struct rds_sock *rs = NULL;
490 struct rm_atomic_op *ao;
491 struct rds_notifier *notifier;
494 spin_lock_irqsave(&rm->m_rs_lock, flags);
497 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
498 && ao->op_active && ao->op_notify && ao->op_notifier) {
499 notifier = ao->op_notifier;
501 sock_hold(rds_rs_to_sk(rs));
503 notifier->n_status = status;
504 spin_lock(&rs->rs_lock);
505 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
506 spin_unlock(&rs->rs_lock);
508 ao->op_notifier = NULL;
511 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
514 rds_wake_sk_sleep(rs);
515 sock_put(rds_rs_to_sk(rs));
518 EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
521 * This is the same as rds_rdma_send_complete except we
522 * don't do any locking - we have all the ingredients (message,
523 * socket, socket lock) and can just move the notifier.
526 __rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
528 struct rm_rdma_op *ro;
529 struct rm_atomic_op *ao;
532 if (ro->op_active && ro->op_notify && ro->op_notifier) {
533 ro->op_notifier->n_status = status;
534 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
535 ro->op_notifier = NULL;
539 if (ao->op_active && ao->op_notify && ao->op_notifier) {
540 ao->op_notifier->n_status = status;
541 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
542 ao->op_notifier = NULL;
545 /* No need to wake the app - caller does this */
549 * This is called from the IB send completion when we detect
550 * a RDMA operation that failed with remote access error.
551 * So speed is not an issue here.
553 struct rds_message *rds_send_get_message(struct rds_connection *conn,
554 struct rm_rdma_op *op)
556 struct rds_message *rm, *tmp, *found = NULL;
559 spin_lock_irqsave(&conn->c_lock, flags);
561 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
562 if (&rm->rdma == op) {
563 atomic_inc(&rm->m_refcount);
569 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
570 if (&rm->rdma == op) {
571 atomic_inc(&rm->m_refcount);
578 spin_unlock_irqrestore(&conn->c_lock, flags);
582 EXPORT_SYMBOL_GPL(rds_send_get_message);
585 * This removes messages from the socket's list if they're on it. The list
586 * argument must be private to the caller, we must be able to modify it
587 * without locks. The messages must have a reference held for their
588 * position on the list. This function will drop that reference after
589 * removing the messages from the 'messages' list regardless of if it found
590 * the messages on the socket list or not.
592 static void rds_send_remove_from_sock(struct list_head *messages, int status)
595 struct rds_sock *rs = NULL;
596 struct rds_message *rm;
598 while (!list_empty(messages)) {
601 rm = list_entry(messages->next, struct rds_message,
603 list_del_init(&rm->m_conn_item);
606 * If we see this flag cleared then we're *sure* that someone
607 * else beat us to removing it from the sock. If we race
608 * with their flag update we'll get the lock and then really
609 * see that the flag has been cleared.
611 * The message spinlock makes sure nobody clears rm->m_rs
612 * while we're messing with it. It does not prevent the
613 * message from being removed from the socket, though.
615 spin_lock_irqsave(&rm->m_rs_lock, flags);
616 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
617 goto unlock_and_drop;
619 if (rs != rm->m_rs) {
621 rds_wake_sk_sleep(rs);
622 sock_put(rds_rs_to_sk(rs));
626 sock_hold(rds_rs_to_sk(rs));
629 goto unlock_and_drop;
630 spin_lock(&rs->rs_lock);
632 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
633 struct rm_rdma_op *ro = &rm->rdma;
634 struct rds_notifier *notifier;
636 list_del_init(&rm->m_sock_item);
637 rds_send_sndbuf_remove(rs, rm);
639 if (ro->op_active && ro->op_notifier &&
640 (ro->op_notify || (ro->op_recverr && status))) {
641 notifier = ro->op_notifier;
642 list_add_tail(¬ifier->n_list,
643 &rs->rs_notify_queue);
644 if (!notifier->n_status)
645 notifier->n_status = status;
646 rm->rdma.op_notifier = NULL;
651 spin_unlock(&rs->rs_lock);
654 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
661 rds_wake_sk_sleep(rs);
662 sock_put(rds_rs_to_sk(rs));
667 * Transports call here when they've determined that the receiver queued
668 * messages up to, and including, the given sequence number. Messages are
669 * moved to the retrans queue when rds_send_xmit picks them off the send
670 * queue. This means that in the TCP case, the message may not have been
671 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
672 * checks the RDS_MSG_HAS_ACK_SEQ bit.
674 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
675 is_acked_func is_acked)
677 struct rds_message *rm, *tmp;
681 spin_lock_irqsave(&conn->c_lock, flags);
683 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
684 if (!rds_send_is_acked(rm, ack, is_acked))
687 list_move(&rm->m_conn_item, &list);
688 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
691 /* order flag updates with spin locks */
692 if (!list_empty(&list))
693 smp_mb__after_atomic();
695 spin_unlock_irqrestore(&conn->c_lock, flags);
697 /* now remove the messages from the sock list as needed */
698 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
700 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
702 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
704 struct rds_message *rm, *tmp;
705 struct rds_connection *conn;
709 /* get all the messages we're dropping under the rs lock */
710 spin_lock_irqsave(&rs->rs_lock, flags);
712 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
713 if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
714 dest->sin_port != rm->m_inc.i_hdr.h_dport))
717 list_move(&rm->m_sock_item, &list);
718 rds_send_sndbuf_remove(rs, rm);
719 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
722 /* order flag updates with the rs lock */
723 smp_mb__after_atomic();
725 spin_unlock_irqrestore(&rs->rs_lock, flags);
727 if (list_empty(&list))
730 /* Remove the messages from the conn */
731 list_for_each_entry(rm, &list, m_sock_item) {
733 conn = rm->m_inc.i_conn;
735 spin_lock_irqsave(&conn->c_lock, flags);
737 * Maybe someone else beat us to removing rm from the conn.
738 * If we race with their flag update we'll get the lock and
739 * then really see that the flag has been cleared.
741 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
742 spin_unlock_irqrestore(&conn->c_lock, flags);
743 spin_lock_irqsave(&rm->m_rs_lock, flags);
745 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
748 list_del_init(&rm->m_conn_item);
749 spin_unlock_irqrestore(&conn->c_lock, flags);
752 * Couldn't grab m_rs_lock in top loop (lock ordering),
755 spin_lock_irqsave(&rm->m_rs_lock, flags);
757 spin_lock(&rs->rs_lock);
758 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
759 spin_unlock(&rs->rs_lock);
762 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
767 rds_wake_sk_sleep(rs);
769 while (!list_empty(&list)) {
770 rm = list_entry(list.next, struct rds_message, m_sock_item);
771 list_del_init(&rm->m_sock_item);
773 rds_message_wait(rm);
779 * we only want this to fire once so we use the callers 'queued'. It's
780 * possible that another thread can race with us and remove the
781 * message from the flow with RDS_CANCEL_SENT_TO.
783 static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
784 struct rds_message *rm, __be16 sport,
785 __be16 dport, int *queued)
793 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
795 /* this is the only place which holds both the socket's rs_lock
796 * and the connection's c_lock */
797 spin_lock_irqsave(&rs->rs_lock, flags);
800 * If there is a little space in sndbuf, we don't queue anything,
801 * and userspace gets -EAGAIN. But poll() indicates there's send
802 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
803 * freed up by incoming acks. So we check the *old* value of
804 * rs_snd_bytes here to allow the last msg to exceed the buffer,
805 * and poll() now knows no more data can be sent.
807 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
808 rs->rs_snd_bytes += len;
810 /* let recv side know we are close to send space exhaustion.
811 * This is probably not the optimal way to do it, as this
812 * means we set the flag on *all* messages as soon as our
813 * throughput hits a certain threshold.
815 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
816 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
818 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
819 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
820 rds_message_addref(rm);
823 /* The code ordering is a little weird, but we're
824 trying to minimize the time we hold c_lock */
825 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
826 rm->m_inc.i_conn = conn;
827 rds_message_addref(rm);
829 spin_lock(&conn->c_lock);
830 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++);
831 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
832 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
833 spin_unlock(&conn->c_lock);
835 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
836 rm, len, rs, rs->rs_snd_bytes,
837 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
842 spin_unlock_irqrestore(&rs->rs_lock, flags);
848 * rds_message is getting to be quite complicated, and we'd like to allocate
849 * it all in one go. This figures out how big it needs to be up front.
851 static int rds_rm_size(struct msghdr *msg, int data_len)
853 struct cmsghdr *cmsg;
858 for_each_cmsghdr(cmsg, msg) {
859 if (!CMSG_OK(msg, cmsg))
862 if (cmsg->cmsg_level != SOL_RDS)
865 switch (cmsg->cmsg_type) {
866 case RDS_CMSG_RDMA_ARGS:
868 retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
875 case RDS_CMSG_RDMA_DEST:
876 case RDS_CMSG_RDMA_MAP:
878 /* these are valid but do no add any size */
881 case RDS_CMSG_ATOMIC_CSWP:
882 case RDS_CMSG_ATOMIC_FADD:
883 case RDS_CMSG_MASKED_ATOMIC_CSWP:
884 case RDS_CMSG_MASKED_ATOMIC_FADD:
886 size += sizeof(struct scatterlist);
895 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
897 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
898 if (cmsg_groups == 3)
904 static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
905 struct msghdr *msg, int *allocated_mr)
907 struct cmsghdr *cmsg;
910 for_each_cmsghdr(cmsg, msg) {
911 if (!CMSG_OK(msg, cmsg))
914 if (cmsg->cmsg_level != SOL_RDS)
917 /* As a side effect, RDMA_DEST and RDMA_MAP will set
918 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
920 switch (cmsg->cmsg_type) {
921 case RDS_CMSG_RDMA_ARGS:
922 ret = rds_cmsg_rdma_args(rs, rm, cmsg);
925 case RDS_CMSG_RDMA_DEST:
926 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
929 case RDS_CMSG_RDMA_MAP:
930 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
934 case RDS_CMSG_ATOMIC_CSWP:
935 case RDS_CMSG_ATOMIC_FADD:
936 case RDS_CMSG_MASKED_ATOMIC_CSWP:
937 case RDS_CMSG_MASKED_ATOMIC_FADD:
938 ret = rds_cmsg_atomic(rs, rm, cmsg);
952 int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
954 struct sock *sk = sock->sk;
955 struct rds_sock *rs = rds_sk_to_rs(sk);
956 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
959 struct rds_message *rm = NULL;
960 struct rds_connection *conn;
962 int queued = 0, allocated_mr = 0;
963 int nonblock = msg->msg_flags & MSG_DONTWAIT;
964 long timeo = sock_sndtimeo(sk, nonblock);
966 /* Mirror Linux UDP mirror of BSD error message compatibility */
967 /* XXX: Perhaps MSG_MORE someday */
968 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
973 if (msg->msg_namelen) {
974 /* XXX fail non-unicast destination IPs? */
975 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
979 daddr = usin->sin_addr.s_addr;
980 dport = usin->sin_port;
982 /* We only care about consistency with ->connect() */
984 daddr = rs->rs_conn_addr;
985 dport = rs->rs_conn_port;
989 /* racing with another thread binding seems ok here */
990 if (daddr == 0 || rs->rs_bound_addr == 0) {
991 ret = -ENOTCONN; /* XXX not a great errno */
995 /* size of rm including all sgs */
996 ret = rds_rm_size(msg, payload_len);
1000 rm = rds_message_alloc(ret, GFP_KERNEL);
1006 /* Attach data to the rm */
1008 rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
1009 if (!rm->data.op_sg) {
1013 ret = rds_message_copy_from_user(rm, &msg->msg_iter);
1017 rm->data.op_active = 1;
1019 rm->m_daddr = daddr;
1021 /* rds_conn_create has a spinlock that runs with IRQ off.
1022 * Caching the conn in the socket helps a lot. */
1023 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
1026 conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
1028 sock->sk->sk_allocation);
1030 ret = PTR_ERR(conn);
1036 /* Parse any control messages the user may have included. */
1037 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
1041 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
1042 printk_ratelimited(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
1043 &rm->rdma, conn->c_trans->xmit_rdma);
1048 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
1049 printk_ratelimited(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
1050 &rm->atomic, conn->c_trans->xmit_atomic);
1055 rds_conn_connect_if_down(conn);
1057 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
1059 rs->rs_seen_congestion = 1;
1063 while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port,
1065 rds_stats_inc(s_send_queue_full);
1066 /* XXX make sure this is reasonable */
1067 if (payload_len > rds_sk_sndbuf(rs)) {
1076 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
1077 rds_send_queue_rm(rs, conn, rm,
1082 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
1083 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
1093 * By now we've committed to the send. We reuse rds_send_worker()
1094 * to retry sends in the rds thread if the transport asks us to.
1096 rds_stats_inc(s_send_queued);
1098 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1099 rds_send_xmit(conn);
1101 rds_message_put(rm);
1105 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1106 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1107 * or in any other way, we need to destroy the MR again */
1109 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
1112 rds_message_put(rm);
1117 * Reply to a ping packet.
1120 rds_send_pong(struct rds_connection *conn, __be16 dport)
1122 struct rds_message *rm;
1123 unsigned long flags;
1126 rm = rds_message_alloc(0, GFP_ATOMIC);
1132 rm->m_daddr = conn->c_faddr;
1133 rm->data.op_active = 1;
1135 rds_conn_connect_if_down(conn);
1137 ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL);
1141 spin_lock_irqsave(&conn->c_lock, flags);
1142 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
1143 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1144 rds_message_addref(rm);
1145 rm->m_inc.i_conn = conn;
1147 rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport,
1148 conn->c_next_tx_seq);
1149 conn->c_next_tx_seq++;
1150 spin_unlock_irqrestore(&conn->c_lock, flags);
1152 rds_stats_inc(s_send_queued);
1153 rds_stats_inc(s_send_pong);
1155 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
1156 queue_delayed_work(rds_wq, &conn->c_send_w, 0);
1158 rds_message_put(rm);
1163 rds_message_put(rm);