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v3.5.6
  1/*
  2 * Copyright (c) 2006 Oracle.  All rights reserved.
  3 *
  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:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 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.
 22 *
 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
 30 * SOFTWARE.
 31 *
 32 */
 33#include <linux/kernel.h>
 34#include <linux/slab.h>
 35#include <net/sock.h>
 36#include <linux/in.h>
 37#include <linux/export.h>
 
 
 38
 39#include "rds.h"
 40
 41void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
 42		  __be32 saddr)
 43{
 44	atomic_set(&inc->i_refcount, 1);
 
 
 45	INIT_LIST_HEAD(&inc->i_item);
 46	inc->i_conn = conn;
 47	inc->i_saddr = saddr;
 48	inc->i_rdma_cookie = 0;
 
 
 
 
 
 49}
 50EXPORT_SYMBOL_GPL(rds_inc_init);
 51
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 52static void rds_inc_addref(struct rds_incoming *inc)
 53{
 54	rdsdebug("addref inc %p ref %d\n", inc, atomic_read(&inc->i_refcount));
 55	atomic_inc(&inc->i_refcount);
 56}
 57
 58void rds_inc_put(struct rds_incoming *inc)
 59{
 60	rdsdebug("put inc %p ref %d\n", inc, atomic_read(&inc->i_refcount));
 61	if (atomic_dec_and_test(&inc->i_refcount)) {
 62		BUG_ON(!list_empty(&inc->i_item));
 63
 64		inc->i_conn->c_trans->inc_free(inc);
 65	}
 66}
 67EXPORT_SYMBOL_GPL(rds_inc_put);
 68
 69static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
 70				  struct rds_cong_map *map,
 71				  int delta, __be16 port)
 72{
 73	int now_congested;
 74
 75	if (delta == 0)
 76		return;
 77
 78	rs->rs_rcv_bytes += delta;
 
 
 
 
 79	now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs);
 80
 81	rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d "
 82	  "now_cong %d delta %d\n",
 83	  rs, &rs->rs_bound_addr,
 84	  ntohs(rs->rs_bound_port), rs->rs_rcv_bytes,
 85	  rds_sk_rcvbuf(rs), now_congested, delta);
 86
 87	/* wasn't -> am congested */
 88	if (!rs->rs_congested && now_congested) {
 89		rs->rs_congested = 1;
 90		rds_cong_set_bit(map, port);
 91		rds_cong_queue_updates(map);
 92	}
 93	/* was -> aren't congested */
 94	/* Require more free space before reporting uncongested to prevent
 95	   bouncing cong/uncong state too often */
 96	else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) {
 97		rs->rs_congested = 0;
 98		rds_cong_clear_bit(map, port);
 99		rds_cong_queue_updates(map);
100	}
101
102	/* do nothing if no change in cong state */
103}
104
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
105/*
106 * Process all extension headers that come with this message.
107 */
108static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs)
109{
110	struct rds_header *hdr = &inc->i_hdr;
111	unsigned int pos = 0, type, len;
112	union {
113		struct rds_ext_header_version version;
114		struct rds_ext_header_rdma rdma;
115		struct rds_ext_header_rdma_dest rdma_dest;
116	} buffer;
117
118	while (1) {
119		len = sizeof(buffer);
120		type = rds_message_next_extension(hdr, &pos, &buffer, &len);
121		if (type == RDS_EXTHDR_NONE)
122			break;
123		/* Process extension header here */
124		switch (type) {
125		case RDS_EXTHDR_RDMA:
126			rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0);
127			break;
128
129		case RDS_EXTHDR_RDMA_DEST:
130			/* We ignore the size for now. We could stash it
131			 * somewhere and use it for error checking. */
132			inc->i_rdma_cookie = rds_rdma_make_cookie(
133					be32_to_cpu(buffer.rdma_dest.h_rdma_rkey),
134					be32_to_cpu(buffer.rdma_dest.h_rdma_offset));
135
136			break;
137		}
138	}
139}
140
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
141/*
142 * The transport must make sure that this is serialized against other
143 * rx and conn reset on this specific conn.
144 *
145 * We currently assert that only one fragmented message will be sent
146 * down a connection at a time.  This lets us reassemble in the conn
147 * instead of per-flow which means that we don't have to go digging through
148 * flows to tear down partial reassembly progress on conn failure and
149 * we save flow lookup and locking for each frag arrival.  It does mean
150 * that small messages will wait behind large ones.  Fragmenting at all
151 * is only to reduce the memory consumption of pre-posted buffers.
152 *
153 * The caller passes in saddr and daddr instead of us getting it from the
154 * conn.  This lets loopback, who only has one conn for both directions,
155 * tell us which roles the addrs in the conn are playing for this message.
156 */
157void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
158		       struct rds_incoming *inc, gfp_t gfp)
159{
160	struct rds_sock *rs = NULL;
161	struct sock *sk;
162	unsigned long flags;
 
163
164	inc->i_conn = conn;
165	inc->i_rx_jiffies = jiffies;
 
 
 
 
166
167	rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u "
168		 "flags 0x%x rx_jiffies %lu\n", conn,
169		 (unsigned long long)conn->c_next_rx_seq,
170		 inc,
171		 (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence),
172		 be32_to_cpu(inc->i_hdr.h_len),
173		 be16_to_cpu(inc->i_hdr.h_sport),
174		 be16_to_cpu(inc->i_hdr.h_dport),
175		 inc->i_hdr.h_flags,
176		 inc->i_rx_jiffies);
177
178	/*
179	 * Sequence numbers should only increase.  Messages get their
180	 * sequence number as they're queued in a sending conn.  They
181	 * can be dropped, though, if the sending socket is closed before
182	 * they hit the wire.  So sequence numbers can skip forward
183	 * under normal operation.  They can also drop back in the conn
184	 * failover case as previously sent messages are resent down the
185	 * new instance of a conn.  We drop those, otherwise we have
186	 * to assume that the next valid seq does not come after a
187	 * hole in the fragment stream.
188	 *
189	 * The headers don't give us a way to realize if fragments of
190	 * a message have been dropped.  We assume that frags that arrive
191	 * to a flow are part of the current message on the flow that is
192	 * being reassembled.  This means that senders can't drop messages
193	 * from the sending conn until all their frags are sent.
194	 *
195	 * XXX we could spend more on the wire to get more robust failure
196	 * detection, arguably worth it to avoid data corruption.
197	 */
198	if (be64_to_cpu(inc->i_hdr.h_sequence) < conn->c_next_rx_seq &&
199	    (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) {
200		rds_stats_inc(s_recv_drop_old_seq);
201		goto out;
202	}
203	conn->c_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1;
204
205	if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) {
 
 
 
 
206		rds_stats_inc(s_recv_ping);
207		rds_send_pong(conn, inc->i_hdr.h_sport);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
208		goto out;
209	}
210
211	rs = rds_find_bound(daddr, inc->i_hdr.h_dport);
212	if (!rs) {
213		rds_stats_inc(s_recv_drop_no_sock);
214		goto out;
215	}
216
217	/* Process extension headers */
218	rds_recv_incoming_exthdrs(inc, rs);
219
220	/* We can be racing with rds_release() which marks the socket dead. */
221	sk = rds_rs_to_sk(rs);
222
223	/* serialize with rds_release -> sock_orphan */
224	write_lock_irqsave(&rs->rs_recv_lock, flags);
225	if (!sock_flag(sk, SOCK_DEAD)) {
226		rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs);
227		rds_stats_inc(s_recv_queued);
228		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
229				      be32_to_cpu(inc->i_hdr.h_len),
230				      inc->i_hdr.h_dport);
 
 
231		rds_inc_addref(inc);
 
232		list_add_tail(&inc->i_item, &rs->rs_recv_queue);
233		__rds_wake_sk_sleep(sk);
234	} else {
235		rds_stats_inc(s_recv_drop_dead_sock);
236	}
237	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
238
239out:
240	if (rs)
241		rds_sock_put(rs);
242}
243EXPORT_SYMBOL_GPL(rds_recv_incoming);
244
245/*
246 * be very careful here.  This is being called as the condition in
247 * wait_event_*() needs to cope with being called many times.
248 */
249static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc)
250{
251	unsigned long flags;
252
253	if (!*inc) {
254		read_lock_irqsave(&rs->rs_recv_lock, flags);
255		if (!list_empty(&rs->rs_recv_queue)) {
256			*inc = list_entry(rs->rs_recv_queue.next,
257					  struct rds_incoming,
258					  i_item);
259			rds_inc_addref(*inc);
260		}
261		read_unlock_irqrestore(&rs->rs_recv_lock, flags);
262	}
263
264	return *inc != NULL;
265}
266
267static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc,
268			    int drop)
269{
270	struct sock *sk = rds_rs_to_sk(rs);
271	int ret = 0;
272	unsigned long flags;
273
274	write_lock_irqsave(&rs->rs_recv_lock, flags);
275	if (!list_empty(&inc->i_item)) {
276		ret = 1;
277		if (drop) {
278			/* XXX make sure this i_conn is reliable */
279			rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
280					      -be32_to_cpu(inc->i_hdr.h_len),
281					      inc->i_hdr.h_dport);
282			list_del_init(&inc->i_item);
283			rds_inc_put(inc);
284		}
285	}
286	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
287
288	rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop);
289	return ret;
290}
291
292/*
293 * Pull errors off the error queue.
294 * If msghdr is NULL, we will just purge the error queue.
295 */
296int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
297{
298	struct rds_notifier *notifier;
299	struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */
300	unsigned int count = 0, max_messages = ~0U;
301	unsigned long flags;
302	LIST_HEAD(copy);
303	int err = 0;
304
305
306	/* put_cmsg copies to user space and thus may sleep. We can't do this
307	 * with rs_lock held, so first grab as many notifications as we can stuff
308	 * in the user provided cmsg buffer. We don't try to copy more, to avoid
309	 * losing notifications - except when the buffer is so small that it wouldn't
310	 * even hold a single notification. Then we give him as much of this single
311	 * msg as we can squeeze in, and set MSG_CTRUNC.
312	 */
313	if (msghdr) {
314		max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg));
315		if (!max_messages)
316			max_messages = 1;
317	}
318
319	spin_lock_irqsave(&rs->rs_lock, flags);
320	while (!list_empty(&rs->rs_notify_queue) && count < max_messages) {
321		notifier = list_entry(rs->rs_notify_queue.next,
322				struct rds_notifier, n_list);
323		list_move(&notifier->n_list, &copy);
324		count++;
325	}
326	spin_unlock_irqrestore(&rs->rs_lock, flags);
327
328	if (!count)
329		return 0;
330
331	while (!list_empty(&copy)) {
332		notifier = list_entry(copy.next, struct rds_notifier, n_list);
333
334		if (msghdr) {
335			cmsg.user_token = notifier->n_user_token;
336			cmsg.status = notifier->n_status;
337
338			err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS,
339				       sizeof(cmsg), &cmsg);
340			if (err)
341				break;
342		}
343
344		list_del_init(&notifier->n_list);
345		kfree(notifier);
346	}
347
348	/* If we bailed out because of an error in put_cmsg,
349	 * we may be left with one or more notifications that we
350	 * didn't process. Return them to the head of the list. */
351	if (!list_empty(&copy)) {
352		spin_lock_irqsave(&rs->rs_lock, flags);
353		list_splice(&copy, &rs->rs_notify_queue);
354		spin_unlock_irqrestore(&rs->rs_lock, flags);
355	}
356
357	return err;
358}
359
360/*
361 * Queue a congestion notification
362 */
363static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr)
364{
365	uint64_t notify = rs->rs_cong_notify;
366	unsigned long flags;
367	int err;
368
369	err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE,
370			sizeof(notify), &notify);
371	if (err)
372		return err;
373
374	spin_lock_irqsave(&rs->rs_lock, flags);
375	rs->rs_cong_notify &= ~notify;
376	spin_unlock_irqrestore(&rs->rs_lock, flags);
377
378	return 0;
379}
380
381/*
382 * Receive any control messages.
383 */
384static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg)
 
385{
386	int ret = 0;
387
388	if (inc->i_rdma_cookie) {
389		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
390				sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie);
391		if (ret)
392			return ret;
393	}
394
395	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
396}
397
398int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
399		size_t size, int msg_flags)
400{
401	struct sock *sk = sock->sk;
402	struct rds_sock *rs = rds_sk_to_rs(sk);
403	long timeo;
404	int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
405	struct sockaddr_in *sin;
406	struct rds_incoming *inc = NULL;
407
408	/* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
409	timeo = sock_rcvtimeo(sk, nonblock);
410
411	rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
412
413	msg->msg_namelen = 0;
414
415	if (msg_flags & MSG_OOB)
416		goto out;
 
 
417
418	while (1) {
419		/* If there are pending notifications, do those - and nothing else */
420		if (!list_empty(&rs->rs_notify_queue)) {
421			ret = rds_notify_queue_get(rs, msg);
422			break;
423		}
424
425		if (rs->rs_cong_notify) {
426			ret = rds_notify_cong(rs, msg);
427			break;
428		}
429
430		if (!rds_next_incoming(rs, &inc)) {
431			if (nonblock) {
432				ret = -EAGAIN;
 
 
433				break;
434			}
435
436			timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
437					(!list_empty(&rs->rs_notify_queue) ||
438					 rs->rs_cong_notify ||
439					 rds_next_incoming(rs, &inc)), timeo);
440			rdsdebug("recvmsg woke inc %p timeo %ld\n", inc,
441				 timeo);
442			if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
443				continue;
444
445			ret = timeo;
446			if (ret == 0)
447				ret = -ETIMEDOUT;
448			break;
449		}
450
451		rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
452			 &inc->i_conn->c_faddr,
453			 ntohs(inc->i_hdr.h_sport));
454		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, msg->msg_iov,
455							     size);
456		if (ret < 0)
457			break;
458
459		/*
460		 * if the message we just copied isn't at the head of the
461		 * recv queue then someone else raced us to return it, try
462		 * to get the next message.
463		 */
464		if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) {
465			rds_inc_put(inc);
466			inc = NULL;
467			rds_stats_inc(s_recv_deliver_raced);
 
468			continue;
469		}
470
471		if (ret < be32_to_cpu(inc->i_hdr.h_len)) {
472			if (msg_flags & MSG_TRUNC)
473				ret = be32_to_cpu(inc->i_hdr.h_len);
474			msg->msg_flags |= MSG_TRUNC;
475		}
476
477		if (rds_cmsg_recv(inc, msg)) {
478			ret = -EFAULT;
479			goto out;
480		}
 
481
482		rds_stats_inc(s_recv_delivered);
483
484		sin = (struct sockaddr_in *)msg->msg_name;
485		if (sin) {
486			sin->sin_family = AF_INET;
487			sin->sin_port = inc->i_hdr.h_sport;
488			sin->sin_addr.s_addr = inc->i_saddr;
489			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
490			msg->msg_namelen = sizeof(*sin);
491		}
492		break;
493	}
494
495	if (inc)
496		rds_inc_put(inc);
497
498out:
499	return ret;
500}
501
502/*
503 * The socket is being shut down and we're asked to drop messages that were
504 * queued for recvmsg.  The caller has unbound the socket so the receive path
505 * won't queue any more incoming fragments or messages on the socket.
506 */
507void rds_clear_recv_queue(struct rds_sock *rs)
508{
509	struct sock *sk = rds_rs_to_sk(rs);
510	struct rds_incoming *inc, *tmp;
511	unsigned long flags;
512
513	write_lock_irqsave(&rs->rs_recv_lock, flags);
514	list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) {
515		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
516				      -be32_to_cpu(inc->i_hdr.h_len),
517				      inc->i_hdr.h_dport);
518		list_del_init(&inc->i_item);
519		rds_inc_put(inc);
520	}
521	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
522}
523
524/*
525 * inc->i_saddr isn't used here because it is only set in the receive
526 * path.
527 */
528void rds_inc_info_copy(struct rds_incoming *inc,
529		       struct rds_info_iterator *iter,
530		       __be32 saddr, __be32 daddr, int flip)
531{
532	struct rds_info_message minfo;
533
534	minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence);
535	minfo.len = be32_to_cpu(inc->i_hdr.h_len);
536
537	if (flip) {
538		minfo.laddr = daddr;
539		minfo.faddr = saddr;
540		minfo.lport = inc->i_hdr.h_dport;
541		minfo.fport = inc->i_hdr.h_sport;
542	} else {
543		minfo.laddr = saddr;
544		minfo.faddr = daddr;
545		minfo.lport = inc->i_hdr.h_sport;
546		minfo.fport = inc->i_hdr.h_dport;
547	}
 
 
548
549	rds_info_copy(iter, &minfo, sizeof(minfo));
550}
v4.17
  1/*
  2 * Copyright (c) 2006 Oracle.  All rights reserved.
  3 *
  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:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 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.
 22 *
 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
 30 * SOFTWARE.
 31 *
 32 */
 33#include <linux/kernel.h>
 34#include <linux/slab.h>
 35#include <net/sock.h>
 36#include <linux/in.h>
 37#include <linux/export.h>
 38#include <linux/time.h>
 39#include <linux/rds.h>
 40
 41#include "rds.h"
 42
 43void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
 44		  __be32 saddr)
 45{
 46	int i;
 47
 48	refcount_set(&inc->i_refcount, 1);
 49	INIT_LIST_HEAD(&inc->i_item);
 50	inc->i_conn = conn;
 51	inc->i_saddr = saddr;
 52	inc->i_rdma_cookie = 0;
 53	inc->i_rx_tstamp.tv_sec = 0;
 54	inc->i_rx_tstamp.tv_usec = 0;
 55
 56	for (i = 0; i < RDS_RX_MAX_TRACES; i++)
 57		inc->i_rx_lat_trace[i] = 0;
 58}
 59EXPORT_SYMBOL_GPL(rds_inc_init);
 60
 61void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp,
 62		       __be32 saddr)
 63{
 64	refcount_set(&inc->i_refcount, 1);
 65	INIT_LIST_HEAD(&inc->i_item);
 66	inc->i_conn = cp->cp_conn;
 67	inc->i_conn_path = cp;
 68	inc->i_saddr = saddr;
 69	inc->i_rdma_cookie = 0;
 70	inc->i_rx_tstamp.tv_sec = 0;
 71	inc->i_rx_tstamp.tv_usec = 0;
 72}
 73EXPORT_SYMBOL_GPL(rds_inc_path_init);
 74
 75static void rds_inc_addref(struct rds_incoming *inc)
 76{
 77	rdsdebug("addref inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));
 78	refcount_inc(&inc->i_refcount);
 79}
 80
 81void rds_inc_put(struct rds_incoming *inc)
 82{
 83	rdsdebug("put inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));
 84	if (refcount_dec_and_test(&inc->i_refcount)) {
 85		BUG_ON(!list_empty(&inc->i_item));
 86
 87		inc->i_conn->c_trans->inc_free(inc);
 88	}
 89}
 90EXPORT_SYMBOL_GPL(rds_inc_put);
 91
 92static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
 93				  struct rds_cong_map *map,
 94				  int delta, __be16 port)
 95{
 96	int now_congested;
 97
 98	if (delta == 0)
 99		return;
100
101	rs->rs_rcv_bytes += delta;
102	if (delta > 0)
103		rds_stats_add(s_recv_bytes_added_to_socket, delta);
104	else
105		rds_stats_add(s_recv_bytes_removed_from_socket, -delta);
106	now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs);
107
108	rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d "
109	  "now_cong %d delta %d\n",
110	  rs, &rs->rs_bound_addr,
111	  ntohs(rs->rs_bound_port), rs->rs_rcv_bytes,
112	  rds_sk_rcvbuf(rs), now_congested, delta);
113
114	/* wasn't -> am congested */
115	if (!rs->rs_congested && now_congested) {
116		rs->rs_congested = 1;
117		rds_cong_set_bit(map, port);
118		rds_cong_queue_updates(map);
119	}
120	/* was -> aren't congested */
121	/* Require more free space before reporting uncongested to prevent
122	   bouncing cong/uncong state too often */
123	else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) {
124		rs->rs_congested = 0;
125		rds_cong_clear_bit(map, port);
126		rds_cong_queue_updates(map);
127	}
128
129	/* do nothing if no change in cong state */
130}
131
132static void rds_conn_peer_gen_update(struct rds_connection *conn,
133				     u32 peer_gen_num)
134{
135	int i;
136	struct rds_message *rm, *tmp;
137	unsigned long flags;
138
139	WARN_ON(conn->c_trans->t_type != RDS_TRANS_TCP);
140	if (peer_gen_num != 0) {
141		if (conn->c_peer_gen_num != 0 &&
142		    peer_gen_num != conn->c_peer_gen_num) {
143			for (i = 0; i < RDS_MPATH_WORKERS; i++) {
144				struct rds_conn_path *cp;
145
146				cp = &conn->c_path[i];
147				spin_lock_irqsave(&cp->cp_lock, flags);
148				cp->cp_next_tx_seq = 1;
149				cp->cp_next_rx_seq = 0;
150				list_for_each_entry_safe(rm, tmp,
151							 &cp->cp_retrans,
152							 m_conn_item) {
153					set_bit(RDS_MSG_FLUSH, &rm->m_flags);
154				}
155				spin_unlock_irqrestore(&cp->cp_lock, flags);
156			}
157		}
158		conn->c_peer_gen_num = peer_gen_num;
159	}
160}
161
162/*
163 * Process all extension headers that come with this message.
164 */
165static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs)
166{
167	struct rds_header *hdr = &inc->i_hdr;
168	unsigned int pos = 0, type, len;
169	union {
170		struct rds_ext_header_version version;
171		struct rds_ext_header_rdma rdma;
172		struct rds_ext_header_rdma_dest rdma_dest;
173	} buffer;
174
175	while (1) {
176		len = sizeof(buffer);
177		type = rds_message_next_extension(hdr, &pos, &buffer, &len);
178		if (type == RDS_EXTHDR_NONE)
179			break;
180		/* Process extension header here */
181		switch (type) {
182		case RDS_EXTHDR_RDMA:
183			rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0);
184			break;
185
186		case RDS_EXTHDR_RDMA_DEST:
187			/* We ignore the size for now. We could stash it
188			 * somewhere and use it for error checking. */
189			inc->i_rdma_cookie = rds_rdma_make_cookie(
190					be32_to_cpu(buffer.rdma_dest.h_rdma_rkey),
191					be32_to_cpu(buffer.rdma_dest.h_rdma_offset));
192
193			break;
194		}
195	}
196}
197
198static void rds_recv_hs_exthdrs(struct rds_header *hdr,
199				struct rds_connection *conn)
200{
201	unsigned int pos = 0, type, len;
202	union {
203		struct rds_ext_header_version version;
204		u16 rds_npaths;
205		u32 rds_gen_num;
206	} buffer;
207	u32 new_peer_gen_num = 0;
208
209	while (1) {
210		len = sizeof(buffer);
211		type = rds_message_next_extension(hdr, &pos, &buffer, &len);
212		if (type == RDS_EXTHDR_NONE)
213			break;
214		/* Process extension header here */
215		switch (type) {
216		case RDS_EXTHDR_NPATHS:
217			conn->c_npaths = min_t(int, RDS_MPATH_WORKERS,
218					       be16_to_cpu(buffer.rds_npaths));
219			break;
220		case RDS_EXTHDR_GEN_NUM:
221			new_peer_gen_num = be32_to_cpu(buffer.rds_gen_num);
222			break;
223		default:
224			pr_warn_ratelimited("ignoring unknown exthdr type "
225					     "0x%x\n", type);
226		}
227	}
228	/* if RDS_EXTHDR_NPATHS was not found, default to a single-path */
229	conn->c_npaths = max_t(int, conn->c_npaths, 1);
230	conn->c_ping_triggered = 0;
231	rds_conn_peer_gen_update(conn, new_peer_gen_num);
232}
233
234/* rds_start_mprds() will synchronously start multiple paths when appropriate.
235 * The scheme is based on the following rules:
236 *
237 * 1. rds_sendmsg on first connect attempt sends the probe ping, with the
238 *    sender's npaths (s_npaths)
239 * 2. rcvr of probe-ping knows the mprds_paths = min(s_npaths, r_npaths). It
240 *    sends back a probe-pong with r_npaths. After that, if rcvr is the
241 *    smaller ip addr, it starts rds_conn_path_connect_if_down on all
242 *    mprds_paths.
243 * 3. sender gets woken up, and can move to rds_conn_path_connect_if_down.
244 *    If it is the smaller ipaddr, rds_conn_path_connect_if_down can be
245 *    called after reception of the probe-pong on all mprds_paths.
246 *    Otherwise (sender of probe-ping is not the smaller ip addr): just call
247 *    rds_conn_path_connect_if_down on the hashed path. (see rule 4)
248 * 4. rds_connect_worker must only trigger a connection if laddr < faddr.
249 * 5. sender may end up queuing the packet on the cp. will get sent out later.
250 *    when connection is completed.
251 */
252static void rds_start_mprds(struct rds_connection *conn)
253{
254	int i;
255	struct rds_conn_path *cp;
256
257	if (conn->c_npaths > 1 &&
258	    IS_CANONICAL(conn->c_laddr, conn->c_faddr)) {
259		for (i = 0; i < conn->c_npaths; i++) {
260			cp = &conn->c_path[i];
261			rds_conn_path_connect_if_down(cp);
262		}
263	}
264}
265
266/*
267 * The transport must make sure that this is serialized against other
268 * rx and conn reset on this specific conn.
269 *
270 * We currently assert that only one fragmented message will be sent
271 * down a connection at a time.  This lets us reassemble in the conn
272 * instead of per-flow which means that we don't have to go digging through
273 * flows to tear down partial reassembly progress on conn failure and
274 * we save flow lookup and locking for each frag arrival.  It does mean
275 * that small messages will wait behind large ones.  Fragmenting at all
276 * is only to reduce the memory consumption of pre-posted buffers.
277 *
278 * The caller passes in saddr and daddr instead of us getting it from the
279 * conn.  This lets loopback, who only has one conn for both directions,
280 * tell us which roles the addrs in the conn are playing for this message.
281 */
282void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
283		       struct rds_incoming *inc, gfp_t gfp)
284{
285	struct rds_sock *rs = NULL;
286	struct sock *sk;
287	unsigned long flags;
288	struct rds_conn_path *cp;
289
290	inc->i_conn = conn;
291	inc->i_rx_jiffies = jiffies;
292	if (conn->c_trans->t_mp_capable)
293		cp = inc->i_conn_path;
294	else
295		cp = &conn->c_path[0];
296
297	rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u "
298		 "flags 0x%x rx_jiffies %lu\n", conn,
299		 (unsigned long long)cp->cp_next_rx_seq,
300		 inc,
301		 (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence),
302		 be32_to_cpu(inc->i_hdr.h_len),
303		 be16_to_cpu(inc->i_hdr.h_sport),
304		 be16_to_cpu(inc->i_hdr.h_dport),
305		 inc->i_hdr.h_flags,
306		 inc->i_rx_jiffies);
307
308	/*
309	 * Sequence numbers should only increase.  Messages get their
310	 * sequence number as they're queued in a sending conn.  They
311	 * can be dropped, though, if the sending socket is closed before
312	 * they hit the wire.  So sequence numbers can skip forward
313	 * under normal operation.  They can also drop back in the conn
314	 * failover case as previously sent messages are resent down the
315	 * new instance of a conn.  We drop those, otherwise we have
316	 * to assume that the next valid seq does not come after a
317	 * hole in the fragment stream.
318	 *
319	 * The headers don't give us a way to realize if fragments of
320	 * a message have been dropped.  We assume that frags that arrive
321	 * to a flow are part of the current message on the flow that is
322	 * being reassembled.  This means that senders can't drop messages
323	 * from the sending conn until all their frags are sent.
324	 *
325	 * XXX we could spend more on the wire to get more robust failure
326	 * detection, arguably worth it to avoid data corruption.
327	 */
328	if (be64_to_cpu(inc->i_hdr.h_sequence) < cp->cp_next_rx_seq &&
329	    (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) {
330		rds_stats_inc(s_recv_drop_old_seq);
331		goto out;
332	}
333	cp->cp_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1;
334
335	if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) {
336		if (inc->i_hdr.h_sport == 0) {
337			rdsdebug("ignore ping with 0 sport from 0x%x\n", saddr);
338			goto out;
339		}
340		rds_stats_inc(s_recv_ping);
341		rds_send_pong(cp, inc->i_hdr.h_sport);
342		/* if this is a handshake ping, start multipath if necessary */
343		if (RDS_HS_PROBE(be16_to_cpu(inc->i_hdr.h_sport),
344				 be16_to_cpu(inc->i_hdr.h_dport))) {
345			rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn);
346			rds_start_mprds(cp->cp_conn);
347		}
348		goto out;
349	}
350
351	if (be16_to_cpu(inc->i_hdr.h_dport) ==  RDS_FLAG_PROBE_PORT &&
352	    inc->i_hdr.h_sport == 0) {
353		rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn);
354		/* if this is a handshake pong, start multipath if necessary */
355		rds_start_mprds(cp->cp_conn);
356		wake_up(&cp->cp_conn->c_hs_waitq);
357		goto out;
358	}
359
360	rs = rds_find_bound(daddr, inc->i_hdr.h_dport);
361	if (!rs) {
362		rds_stats_inc(s_recv_drop_no_sock);
363		goto out;
364	}
365
366	/* Process extension headers */
367	rds_recv_incoming_exthdrs(inc, rs);
368
369	/* We can be racing with rds_release() which marks the socket dead. */
370	sk = rds_rs_to_sk(rs);
371
372	/* serialize with rds_release -> sock_orphan */
373	write_lock_irqsave(&rs->rs_recv_lock, flags);
374	if (!sock_flag(sk, SOCK_DEAD)) {
375		rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs);
376		rds_stats_inc(s_recv_queued);
377		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
378				      be32_to_cpu(inc->i_hdr.h_len),
379				      inc->i_hdr.h_dport);
380		if (sock_flag(sk, SOCK_RCVTSTAMP))
381			do_gettimeofday(&inc->i_rx_tstamp);
382		rds_inc_addref(inc);
383		inc->i_rx_lat_trace[RDS_MSG_RX_END] = local_clock();
384		list_add_tail(&inc->i_item, &rs->rs_recv_queue);
385		__rds_wake_sk_sleep(sk);
386	} else {
387		rds_stats_inc(s_recv_drop_dead_sock);
388	}
389	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
390
391out:
392	if (rs)
393		rds_sock_put(rs);
394}
395EXPORT_SYMBOL_GPL(rds_recv_incoming);
396
397/*
398 * be very careful here.  This is being called as the condition in
399 * wait_event_*() needs to cope with being called many times.
400 */
401static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc)
402{
403	unsigned long flags;
404
405	if (!*inc) {
406		read_lock_irqsave(&rs->rs_recv_lock, flags);
407		if (!list_empty(&rs->rs_recv_queue)) {
408			*inc = list_entry(rs->rs_recv_queue.next,
409					  struct rds_incoming,
410					  i_item);
411			rds_inc_addref(*inc);
412		}
413		read_unlock_irqrestore(&rs->rs_recv_lock, flags);
414	}
415
416	return *inc != NULL;
417}
418
419static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc,
420			    int drop)
421{
422	struct sock *sk = rds_rs_to_sk(rs);
423	int ret = 0;
424	unsigned long flags;
425
426	write_lock_irqsave(&rs->rs_recv_lock, flags);
427	if (!list_empty(&inc->i_item)) {
428		ret = 1;
429		if (drop) {
430			/* XXX make sure this i_conn is reliable */
431			rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
432					      -be32_to_cpu(inc->i_hdr.h_len),
433					      inc->i_hdr.h_dport);
434			list_del_init(&inc->i_item);
435			rds_inc_put(inc);
436		}
437	}
438	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
439
440	rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop);
441	return ret;
442}
443
444/*
445 * Pull errors off the error queue.
446 * If msghdr is NULL, we will just purge the error queue.
447 */
448int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
449{
450	struct rds_notifier *notifier;
451	struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */
452	unsigned int count = 0, max_messages = ~0U;
453	unsigned long flags;
454	LIST_HEAD(copy);
455	int err = 0;
456
457
458	/* put_cmsg copies to user space and thus may sleep. We can't do this
459	 * with rs_lock held, so first grab as many notifications as we can stuff
460	 * in the user provided cmsg buffer. We don't try to copy more, to avoid
461	 * losing notifications - except when the buffer is so small that it wouldn't
462	 * even hold a single notification. Then we give him as much of this single
463	 * msg as we can squeeze in, and set MSG_CTRUNC.
464	 */
465	if (msghdr) {
466		max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg));
467		if (!max_messages)
468			max_messages = 1;
469	}
470
471	spin_lock_irqsave(&rs->rs_lock, flags);
472	while (!list_empty(&rs->rs_notify_queue) && count < max_messages) {
473		notifier = list_entry(rs->rs_notify_queue.next,
474				struct rds_notifier, n_list);
475		list_move(&notifier->n_list, &copy);
476		count++;
477	}
478	spin_unlock_irqrestore(&rs->rs_lock, flags);
479
480	if (!count)
481		return 0;
482
483	while (!list_empty(&copy)) {
484		notifier = list_entry(copy.next, struct rds_notifier, n_list);
485
486		if (msghdr) {
487			cmsg.user_token = notifier->n_user_token;
488			cmsg.status = notifier->n_status;
489
490			err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS,
491				       sizeof(cmsg), &cmsg);
492			if (err)
493				break;
494		}
495
496		list_del_init(&notifier->n_list);
497		kfree(notifier);
498	}
499
500	/* If we bailed out because of an error in put_cmsg,
501	 * we may be left with one or more notifications that we
502	 * didn't process. Return them to the head of the list. */
503	if (!list_empty(&copy)) {
504		spin_lock_irqsave(&rs->rs_lock, flags);
505		list_splice(&copy, &rs->rs_notify_queue);
506		spin_unlock_irqrestore(&rs->rs_lock, flags);
507	}
508
509	return err;
510}
511
512/*
513 * Queue a congestion notification
514 */
515static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr)
516{
517	uint64_t notify = rs->rs_cong_notify;
518	unsigned long flags;
519	int err;
520
521	err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE,
522			sizeof(notify), &notify);
523	if (err)
524		return err;
525
526	spin_lock_irqsave(&rs->rs_lock, flags);
527	rs->rs_cong_notify &= ~notify;
528	spin_unlock_irqrestore(&rs->rs_lock, flags);
529
530	return 0;
531}
532
533/*
534 * Receive any control messages.
535 */
536static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
537			 struct rds_sock *rs)
538{
539	int ret = 0;
540
541	if (inc->i_rdma_cookie) {
542		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
543				sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie);
544		if (ret)
545			goto out;
546	}
547
548	if ((inc->i_rx_tstamp.tv_sec != 0) &&
549	    sock_flag(rds_rs_to_sk(rs), SOCK_RCVTSTAMP)) {
550		ret = put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
551			       sizeof(struct timeval),
552			       &inc->i_rx_tstamp);
553		if (ret)
554			goto out;
555	}
556
557	if (rs->rs_rx_traces) {
558		struct rds_cmsg_rx_trace t;
559		int i, j;
560
561		memset(&t, 0, sizeof(t));
562		inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock();
563		t.rx_traces =  rs->rs_rx_traces;
564		for (i = 0; i < rs->rs_rx_traces; i++) {
565			j = rs->rs_rx_trace[i];
566			t.rx_trace_pos[i] = j;
567			t.rx_trace[i] = inc->i_rx_lat_trace[j + 1] -
568					  inc->i_rx_lat_trace[j];
569		}
570
571		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RXPATH_LATENCY,
572			       sizeof(t), &t);
573		if (ret)
574			goto out;
575	}
576
577out:
578	return ret;
579}
580
581static bool rds_recvmsg_zcookie(struct rds_sock *rs, struct msghdr *msg)
582{
583	struct rds_msg_zcopy_queue *q = &rs->rs_zcookie_queue;
584	struct rds_msg_zcopy_info *info = NULL;
585	struct rds_zcopy_cookies *done;
586	unsigned long flags;
587
588	if (!msg->msg_control)
589		return false;
590
591	if (!sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY) ||
592	    msg->msg_controllen < CMSG_SPACE(sizeof(*done)))
593		return false;
594
595	spin_lock_irqsave(&q->lock, flags);
596	if (!list_empty(&q->zcookie_head)) {
597		info = list_entry(q->zcookie_head.next,
598				  struct rds_msg_zcopy_info, rs_zcookie_next);
599		list_del(&info->rs_zcookie_next);
600	}
601	spin_unlock_irqrestore(&q->lock, flags);
602	if (!info)
603		return false;
604	done = &info->zcookies;
605	if (put_cmsg(msg, SOL_RDS, RDS_CMSG_ZCOPY_COMPLETION, sizeof(*done),
606		     done)) {
607		spin_lock_irqsave(&q->lock, flags);
608		list_add(&info->rs_zcookie_next, &q->zcookie_head);
609		spin_unlock_irqrestore(&q->lock, flags);
610		return false;
611	}
612	kfree(info);
613	return true;
614}
615
616int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
617		int msg_flags)
618{
619	struct sock *sk = sock->sk;
620	struct rds_sock *rs = rds_sk_to_rs(sk);
621	long timeo;
622	int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
623	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
624	struct rds_incoming *inc = NULL;
625
626	/* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
627	timeo = sock_rcvtimeo(sk, nonblock);
628
629	rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
630
 
 
631	if (msg_flags & MSG_OOB)
632		goto out;
633	if (msg_flags & MSG_ERRQUEUE)
634		return sock_recv_errqueue(sk, msg, size, SOL_IP, IP_RECVERR);
635
636	while (1) {
637		/* If there are pending notifications, do those - and nothing else */
638		if (!list_empty(&rs->rs_notify_queue)) {
639			ret = rds_notify_queue_get(rs, msg);
640			break;
641		}
642
643		if (rs->rs_cong_notify) {
644			ret = rds_notify_cong(rs, msg);
645			break;
646		}
647
648		if (!rds_next_incoming(rs, &inc)) {
649			if (nonblock) {
650				bool reaped = rds_recvmsg_zcookie(rs, msg);
651
652				ret = reaped ?  0 : -EAGAIN;
653				break;
654			}
655
656			timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
657					(!list_empty(&rs->rs_notify_queue) ||
658					 rs->rs_cong_notify ||
659					 rds_next_incoming(rs, &inc)), timeo);
660			rdsdebug("recvmsg woke inc %p timeo %ld\n", inc,
661				 timeo);
662			if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
663				continue;
664
665			ret = timeo;
666			if (ret == 0)
667				ret = -ETIMEDOUT;
668			break;
669		}
670
671		rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
672			 &inc->i_conn->c_faddr,
673			 ntohs(inc->i_hdr.h_sport));
674		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter);
 
675		if (ret < 0)
676			break;
677
678		/*
679		 * if the message we just copied isn't at the head of the
680		 * recv queue then someone else raced us to return it, try
681		 * to get the next message.
682		 */
683		if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) {
684			rds_inc_put(inc);
685			inc = NULL;
686			rds_stats_inc(s_recv_deliver_raced);
687			iov_iter_revert(&msg->msg_iter, ret);
688			continue;
689		}
690
691		if (ret < be32_to_cpu(inc->i_hdr.h_len)) {
692			if (msg_flags & MSG_TRUNC)
693				ret = be32_to_cpu(inc->i_hdr.h_len);
694			msg->msg_flags |= MSG_TRUNC;
695		}
696
697		if (rds_cmsg_recv(inc, msg, rs)) {
698			ret = -EFAULT;
699			goto out;
700		}
701		rds_recvmsg_zcookie(rs, msg);
702
703		rds_stats_inc(s_recv_delivered);
704
 
705		if (sin) {
706			sin->sin_family = AF_INET;
707			sin->sin_port = inc->i_hdr.h_sport;
708			sin->sin_addr.s_addr = inc->i_saddr;
709			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
710			msg->msg_namelen = sizeof(*sin);
711		}
712		break;
713	}
714
715	if (inc)
716		rds_inc_put(inc);
717
718out:
719	return ret;
720}
721
722/*
723 * The socket is being shut down and we're asked to drop messages that were
724 * queued for recvmsg.  The caller has unbound the socket so the receive path
725 * won't queue any more incoming fragments or messages on the socket.
726 */
727void rds_clear_recv_queue(struct rds_sock *rs)
728{
729	struct sock *sk = rds_rs_to_sk(rs);
730	struct rds_incoming *inc, *tmp;
731	unsigned long flags;
732
733	write_lock_irqsave(&rs->rs_recv_lock, flags);
734	list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) {
735		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
736				      -be32_to_cpu(inc->i_hdr.h_len),
737				      inc->i_hdr.h_dport);
738		list_del_init(&inc->i_item);
739		rds_inc_put(inc);
740	}
741	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
742}
743
744/*
745 * inc->i_saddr isn't used here because it is only set in the receive
746 * path.
747 */
748void rds_inc_info_copy(struct rds_incoming *inc,
749		       struct rds_info_iterator *iter,
750		       __be32 saddr, __be32 daddr, int flip)
751{
752	struct rds_info_message minfo;
753
754	minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence);
755	minfo.len = be32_to_cpu(inc->i_hdr.h_len);
756
757	if (flip) {
758		minfo.laddr = daddr;
759		minfo.faddr = saddr;
760		minfo.lport = inc->i_hdr.h_dport;
761		minfo.fport = inc->i_hdr.h_sport;
762	} else {
763		minfo.laddr = saddr;
764		minfo.faddr = daddr;
765		minfo.lport = inc->i_hdr.h_sport;
766		minfo.fport = inc->i_hdr.h_dport;
767	}
768
769	minfo.flags = 0;
770
771	rds_info_copy(iter, &minfo, sizeof(minfo));
772}