xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 4f546149)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/uio.h>
52 
53 #include <trace/events/sunrpc.h>
54 
55 #include "sunrpc.h"
56 
57 static void xs_close(struct rpc_xprt *xprt);
58 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
59 		struct socket *sock);
60 
61 /*
62  * xprtsock tunables
63  */
64 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
65 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
66 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
67 
68 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
69 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
70 
71 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
72 
73 #define XS_TCP_LINGER_TO	(15U * HZ)
74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
75 
76 /*
77  * We can register our own files under /proc/sys/sunrpc by
78  * calling register_sysctl_table() again.  The files in that
79  * directory become the union of all files registered there.
80  *
81  * We simply need to make sure that we don't collide with
82  * someone else's file names!
83  */
84 
85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
90 
91 static struct ctl_table_header *sunrpc_table_header;
92 
93 /*
94  * FIXME: changing the UDP slot table size should also resize the UDP
95  *        socket buffers for existing UDP transports
96  */
97 static struct ctl_table xs_tunables_table[] = {
98 	{
99 		.procname	= "udp_slot_table_entries",
100 		.data		= &xprt_udp_slot_table_entries,
101 		.maxlen		= sizeof(unsigned int),
102 		.mode		= 0644,
103 		.proc_handler	= proc_dointvec_minmax,
104 		.extra1		= &min_slot_table_size,
105 		.extra2		= &max_slot_table_size
106 	},
107 	{
108 		.procname	= "tcp_slot_table_entries",
109 		.data		= &xprt_tcp_slot_table_entries,
110 		.maxlen		= sizeof(unsigned int),
111 		.mode		= 0644,
112 		.proc_handler	= proc_dointvec_minmax,
113 		.extra1		= &min_slot_table_size,
114 		.extra2		= &max_slot_table_size
115 	},
116 	{
117 		.procname	= "tcp_max_slot_table_entries",
118 		.data		= &xprt_max_tcp_slot_table_entries,
119 		.maxlen		= sizeof(unsigned int),
120 		.mode		= 0644,
121 		.proc_handler	= proc_dointvec_minmax,
122 		.extra1		= &min_slot_table_size,
123 		.extra2		= &max_tcp_slot_table_limit
124 	},
125 	{
126 		.procname	= "min_resvport",
127 		.data		= &xprt_min_resvport,
128 		.maxlen		= sizeof(unsigned int),
129 		.mode		= 0644,
130 		.proc_handler	= proc_dointvec_minmax,
131 		.extra1		= &xprt_min_resvport_limit,
132 		.extra2		= &xprt_max_resvport
133 	},
134 	{
135 		.procname	= "max_resvport",
136 		.data		= &xprt_max_resvport,
137 		.maxlen		= sizeof(unsigned int),
138 		.mode		= 0644,
139 		.proc_handler	= proc_dointvec_minmax,
140 		.extra1		= &xprt_min_resvport,
141 		.extra2		= &xprt_max_resvport_limit
142 	},
143 	{
144 		.procname	= "tcp_fin_timeout",
145 		.data		= &xs_tcp_fin_timeout,
146 		.maxlen		= sizeof(xs_tcp_fin_timeout),
147 		.mode		= 0644,
148 		.proc_handler	= proc_dointvec_jiffies,
149 	},
150 	{ },
151 };
152 
153 static struct ctl_table sunrpc_table[] = {
154 	{
155 		.procname	= "sunrpc",
156 		.mode		= 0555,
157 		.child		= xs_tunables_table
158 	},
159 	{ },
160 };
161 
162 #endif
163 
164 /*
165  * Wait duration for a reply from the RPC portmapper.
166  */
167 #define XS_BIND_TO		(60U * HZ)
168 
169 /*
170  * Delay if a UDP socket connect error occurs.  This is most likely some
171  * kind of resource problem on the local host.
172  */
173 #define XS_UDP_REEST_TO		(2U * HZ)
174 
175 /*
176  * The reestablish timeout allows clients to delay for a bit before attempting
177  * to reconnect to a server that just dropped our connection.
178  *
179  * We implement an exponential backoff when trying to reestablish a TCP
180  * transport connection with the server.  Some servers like to drop a TCP
181  * connection when they are overworked, so we start with a short timeout and
182  * increase over time if the server is down or not responding.
183  */
184 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
185 
186 /*
187  * TCP idle timeout; client drops the transport socket if it is idle
188  * for this long.  Note that we also timeout UDP sockets to prevent
189  * holding port numbers when there is no RPC traffic.
190  */
191 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
192 
193 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
194 # undef  RPC_DEBUG_DATA
195 # define RPCDBG_FACILITY	RPCDBG_TRANS
196 #endif
197 
198 #ifdef RPC_DEBUG_DATA
199 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
200 {
201 	u8 *buf = (u8 *) packet;
202 	int j;
203 
204 	dprintk("RPC:       %s\n", msg);
205 	for (j = 0; j < count && j < 128; j += 4) {
206 		if (!(j & 31)) {
207 			if (j)
208 				dprintk("\n");
209 			dprintk("0x%04x ", j);
210 		}
211 		dprintk("%02x%02x%02x%02x ",
212 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
213 	}
214 	dprintk("\n");
215 }
216 #else
217 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
218 {
219 	/* NOP */
220 }
221 #endif
222 
223 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
224 {
225 	return (struct rpc_xprt *) sk->sk_user_data;
226 }
227 
228 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
229 {
230 	return (struct sockaddr *) &xprt->addr;
231 }
232 
233 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr_un *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_in *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in6 *) &xprt->addr;
246 }
247 
248 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
249 {
250 	struct sockaddr *sap = xs_addr(xprt);
251 	struct sockaddr_in6 *sin6;
252 	struct sockaddr_in *sin;
253 	struct sockaddr_un *sun;
254 	char buf[128];
255 
256 	switch (sap->sa_family) {
257 	case AF_LOCAL:
258 		sun = xs_addr_un(xprt);
259 		strlcpy(buf, sun->sun_path, sizeof(buf));
260 		xprt->address_strings[RPC_DISPLAY_ADDR] =
261 						kstrdup(buf, GFP_KERNEL);
262 		break;
263 	case AF_INET:
264 		(void)rpc_ntop(sap, buf, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		sin = xs_addr_in(xprt);
268 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
269 		break;
270 	case AF_INET6:
271 		(void)rpc_ntop(sap, buf, sizeof(buf));
272 		xprt->address_strings[RPC_DISPLAY_ADDR] =
273 						kstrdup(buf, GFP_KERNEL);
274 		sin6 = xs_addr_in6(xprt);
275 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
276 		break;
277 	default:
278 		BUG();
279 	}
280 
281 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
282 }
283 
284 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
285 {
286 	struct sockaddr *sap = xs_addr(xprt);
287 	char buf[128];
288 
289 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
290 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
291 
292 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
293 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
294 }
295 
296 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
297 				     const char *protocol,
298 				     const char *netid)
299 {
300 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
301 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
302 	xs_format_common_peer_addresses(xprt);
303 	xs_format_common_peer_ports(xprt);
304 }
305 
306 static void xs_update_peer_port(struct rpc_xprt *xprt)
307 {
308 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
309 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
310 
311 	xs_format_common_peer_ports(xprt);
312 }
313 
314 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
315 {
316 	unsigned int i;
317 
318 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
319 		switch (i) {
320 		case RPC_DISPLAY_PROTO:
321 		case RPC_DISPLAY_NETID:
322 			continue;
323 		default:
324 			kfree(xprt->address_strings[i]);
325 		}
326 }
327 
328 static size_t
329 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
330 {
331 	size_t i,n;
332 
333 	if (!(buf->flags & XDRBUF_SPARSE_PAGES))
334 		return want;
335 	if (want > buf->page_len)
336 		want = buf->page_len;
337 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
338 	for (i = 0; i < n; i++) {
339 		if (buf->pages[i])
340 			continue;
341 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
342 		if (!buf->pages[i]) {
343 			buf->page_len = (i * PAGE_SIZE) - buf->page_base;
344 			return buf->page_len;
345 		}
346 	}
347 	return want;
348 }
349 
350 static ssize_t
351 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
352 {
353 	ssize_t ret;
354 	if (seek != 0)
355 		iov_iter_advance(&msg->msg_iter, seek);
356 	ret = sock_recvmsg(sock, msg, flags);
357 	return ret > 0 ? ret + seek : ret;
358 }
359 
360 static ssize_t
361 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
362 		struct kvec *kvec, size_t count, size_t seek)
363 {
364 	iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, kvec, 1, count);
365 	return xs_sock_recvmsg(sock, msg, flags, seek);
366 }
367 
368 static ssize_t
369 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
370 		struct bio_vec *bvec, unsigned long nr, size_t count,
371 		size_t seek)
372 {
373 	iov_iter_bvec(&msg->msg_iter, READ | ITER_BVEC, bvec, nr, count);
374 	return xs_sock_recvmsg(sock, msg, flags, seek);
375 }
376 
377 static ssize_t
378 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
379 		size_t count)
380 {
381 	struct kvec kvec = { 0 };
382 	return xs_read_kvec(sock, msg, flags | MSG_TRUNC, &kvec, count, 0);
383 }
384 
385 static ssize_t
386 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
387 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
388 {
389 	size_t want, seek_init = seek, offset = 0;
390 	ssize_t ret;
391 
392 	if (seek < buf->head[0].iov_len) {
393 		want = min_t(size_t, count, buf->head[0].iov_len);
394 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
395 		if (ret <= 0)
396 			goto sock_err;
397 		offset += ret;
398 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
399 			goto out;
400 		if (ret != want)
401 			goto eagain;
402 		seek = 0;
403 	} else {
404 		seek -= buf->head[0].iov_len;
405 		offset += buf->head[0].iov_len;
406 	}
407 	if (seek < buf->page_len) {
408 		want = xs_alloc_sparse_pages(buf,
409 				min_t(size_t, count - offset, buf->page_len),
410 				GFP_NOWAIT);
411 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
412 				xdr_buf_pagecount(buf),
413 				want + buf->page_base,
414 				seek + buf->page_base);
415 		if (ret <= 0)
416 			goto sock_err;
417 		offset += ret - buf->page_base;
418 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
419 			goto out;
420 		if (ret != want)
421 			goto eagain;
422 		seek = 0;
423 	} else {
424 		seek -= buf->page_len;
425 		offset += buf->page_len;
426 	}
427 	if (seek < buf->tail[0].iov_len) {
428 		want = min_t(size_t, count - offset, buf->tail[0].iov_len);
429 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
430 		if (ret <= 0)
431 			goto sock_err;
432 		offset += ret;
433 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
434 			goto out;
435 		if (ret != want)
436 			goto eagain;
437 	} else
438 		offset += buf->tail[0].iov_len;
439 	ret = -EMSGSIZE;
440 	msg->msg_flags |= MSG_TRUNC;
441 out:
442 	*read = offset - seek_init;
443 	return ret;
444 eagain:
445 	ret = -EAGAIN;
446 	goto out;
447 sock_err:
448 	offset += seek;
449 	goto out;
450 }
451 
452 static void
453 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
454 {
455 	if (!transport->recv.copied) {
456 		if (buf->head[0].iov_len >= transport->recv.offset)
457 			memcpy(buf->head[0].iov_base,
458 					&transport->recv.xid,
459 					transport->recv.offset);
460 		transport->recv.copied = transport->recv.offset;
461 	}
462 }
463 
464 static bool
465 xs_read_stream_request_done(struct sock_xprt *transport)
466 {
467 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
468 }
469 
470 static ssize_t
471 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
472 		int flags, struct rpc_rqst *req)
473 {
474 	struct xdr_buf *buf = &req->rq_private_buf;
475 	size_t want, read;
476 	ssize_t ret;
477 
478 	xs_read_header(transport, buf);
479 
480 	want = transport->recv.len - transport->recv.offset;
481 	ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
482 			transport->recv.copied + want, transport->recv.copied,
483 			&read);
484 	transport->recv.offset += read;
485 	transport->recv.copied += read;
486 	if (transport->recv.offset == transport->recv.len) {
487 		if (xs_read_stream_request_done(transport))
488 			msg->msg_flags |= MSG_EOR;
489 		return transport->recv.copied;
490 	}
491 
492 	switch (ret) {
493 	case -EMSGSIZE:
494 		return transport->recv.copied;
495 	case 0:
496 		return -ESHUTDOWN;
497 	default:
498 		if (ret < 0)
499 			return ret;
500 	}
501 	return -EAGAIN;
502 }
503 
504 static size_t
505 xs_read_stream_headersize(bool isfrag)
506 {
507 	if (isfrag)
508 		return sizeof(__be32);
509 	return 3 * sizeof(__be32);
510 }
511 
512 static ssize_t
513 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
514 		int flags, size_t want, size_t seek)
515 {
516 	struct kvec kvec = {
517 		.iov_base = &transport->recv.fraghdr,
518 		.iov_len = want,
519 	};
520 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
521 }
522 
523 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
524 static ssize_t
525 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
526 {
527 	struct rpc_xprt *xprt = &transport->xprt;
528 	struct rpc_rqst *req;
529 	ssize_t ret;
530 
531 	/* Look up and lock the request corresponding to the given XID */
532 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
533 	if (!req) {
534 		printk(KERN_WARNING "Callback slot table overflowed\n");
535 		return -ESHUTDOWN;
536 	}
537 
538 	ret = xs_read_stream_request(transport, msg, flags, req);
539 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
540 		xprt_complete_bc_request(req, ret);
541 
542 	return ret;
543 }
544 #else /* CONFIG_SUNRPC_BACKCHANNEL */
545 static ssize_t
546 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
547 {
548 	return -ESHUTDOWN;
549 }
550 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
551 
552 static ssize_t
553 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
554 {
555 	struct rpc_xprt *xprt = &transport->xprt;
556 	struct rpc_rqst *req;
557 	ssize_t ret = 0;
558 
559 	/* Look up and lock the request corresponding to the given XID */
560 	spin_lock(&xprt->queue_lock);
561 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
562 	if (!req) {
563 		msg->msg_flags |= MSG_TRUNC;
564 		goto out;
565 	}
566 	xprt_pin_rqst(req);
567 	spin_unlock(&xprt->queue_lock);
568 
569 	ret = xs_read_stream_request(transport, msg, flags, req);
570 
571 	spin_lock(&xprt->queue_lock);
572 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
573 		xprt_complete_rqst(req->rq_task, ret);
574 	xprt_unpin_rqst(req);
575 out:
576 	spin_unlock(&xprt->queue_lock);
577 	return ret;
578 }
579 
580 static ssize_t
581 xs_read_stream(struct sock_xprt *transport, int flags)
582 {
583 	struct msghdr msg = { 0 };
584 	size_t want, read = 0;
585 	ssize_t ret = 0;
586 
587 	if (transport->recv.len == 0) {
588 		want = xs_read_stream_headersize(transport->recv.copied != 0);
589 		ret = xs_read_stream_header(transport, &msg, flags, want,
590 				transport->recv.offset);
591 		if (ret <= 0)
592 			goto out_err;
593 		transport->recv.offset = ret;
594 		if (ret != want) {
595 			ret = -EAGAIN;
596 			goto out_err;
597 		}
598 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
599 			RPC_FRAGMENT_SIZE_MASK;
600 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
601 		read = ret;
602 	}
603 
604 	switch (be32_to_cpu(transport->recv.calldir)) {
605 	case RPC_CALL:
606 		ret = xs_read_stream_call(transport, &msg, flags);
607 		break;
608 	case RPC_REPLY:
609 		ret = xs_read_stream_reply(transport, &msg, flags);
610 	}
611 	if (msg.msg_flags & MSG_TRUNC) {
612 		transport->recv.calldir = cpu_to_be32(-1);
613 		transport->recv.copied = -1;
614 	}
615 	if (ret < 0)
616 		goto out_err;
617 	read += ret;
618 	if (transport->recv.offset < transport->recv.len) {
619 		ret = xs_read_discard(transport->sock, &msg, flags,
620 				transport->recv.len - transport->recv.offset);
621 		if (ret <= 0)
622 			goto out_err;
623 		transport->recv.offset += ret;
624 		read += ret;
625 		if (transport->recv.offset != transport->recv.len)
626 			return -EAGAIN;
627 	}
628 	if (xs_read_stream_request_done(transport)) {
629 		trace_xs_stream_read_request(transport);
630 		transport->recv.copied = 0;
631 	}
632 	transport->recv.offset = 0;
633 	transport->recv.len = 0;
634 	return read;
635 out_err:
636 	switch (ret) {
637 	case 0:
638 	case -ESHUTDOWN:
639 		xprt_force_disconnect(&transport->xprt);
640 		return -ESHUTDOWN;
641 	}
642 	return ret;
643 }
644 
645 static void xs_stream_data_receive(struct sock_xprt *transport)
646 {
647 	size_t read = 0;
648 	ssize_t ret = 0;
649 
650 	mutex_lock(&transport->recv_mutex);
651 	if (transport->sock == NULL)
652 		goto out;
653 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
654 	for (;;) {
655 		ret = xs_read_stream(transport, MSG_DONTWAIT);
656 		if (ret <= 0)
657 			break;
658 		read += ret;
659 		cond_resched();
660 	}
661 out:
662 	mutex_unlock(&transport->recv_mutex);
663 	trace_xs_stream_read_data(&transport->xprt, ret, read);
664 }
665 
666 static void xs_stream_data_receive_workfn(struct work_struct *work)
667 {
668 	struct sock_xprt *transport =
669 		container_of(work, struct sock_xprt, recv_worker);
670 	xs_stream_data_receive(transport);
671 }
672 
673 static void
674 xs_stream_reset_connect(struct sock_xprt *transport)
675 {
676 	transport->recv.offset = 0;
677 	transport->recv.len = 0;
678 	transport->recv.copied = 0;
679 	transport->xmit.offset = 0;
680 	transport->xprt.stat.connect_count++;
681 	transport->xprt.stat.connect_start = jiffies;
682 }
683 
684 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
685 
686 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
687 {
688 	struct msghdr msg = {
689 		.msg_name	= addr,
690 		.msg_namelen	= addrlen,
691 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
692 	};
693 	struct kvec iov = {
694 		.iov_base	= vec->iov_base + base,
695 		.iov_len	= vec->iov_len - base,
696 	};
697 
698 	if (iov.iov_len != 0)
699 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
700 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
701 }
702 
703 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
704 {
705 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
706 			int offset, size_t size, int flags);
707 	struct page **ppage;
708 	unsigned int remainder;
709 	int err;
710 
711 	remainder = xdr->page_len - base;
712 	base += xdr->page_base;
713 	ppage = xdr->pages + (base >> PAGE_SHIFT);
714 	base &= ~PAGE_MASK;
715 	do_sendpage = sock->ops->sendpage;
716 	if (!zerocopy)
717 		do_sendpage = sock_no_sendpage;
718 	for(;;) {
719 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
720 		int flags = XS_SENDMSG_FLAGS;
721 
722 		remainder -= len;
723 		if (more)
724 			flags |= MSG_MORE;
725 		if (remainder != 0)
726 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
727 		err = do_sendpage(sock, *ppage, base, len, flags);
728 		if (remainder == 0 || err != len)
729 			break;
730 		*sent_p += err;
731 		ppage++;
732 		base = 0;
733 	}
734 	if (err > 0) {
735 		*sent_p += err;
736 		err = 0;
737 	}
738 	return err;
739 }
740 
741 /**
742  * xs_sendpages - write pages directly to a socket
743  * @sock: socket to send on
744  * @addr: UDP only -- address of destination
745  * @addrlen: UDP only -- length of destination address
746  * @xdr: buffer containing this request
747  * @base: starting position in the buffer
748  * @zerocopy: true if it is safe to use sendpage()
749  * @sent_p: return the total number of bytes successfully queued for sending
750  *
751  */
752 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
753 {
754 	unsigned int remainder = xdr->len - base;
755 	int err = 0;
756 	int sent = 0;
757 
758 	if (unlikely(!sock))
759 		return -ENOTSOCK;
760 
761 	if (base != 0) {
762 		addr = NULL;
763 		addrlen = 0;
764 	}
765 
766 	if (base < xdr->head[0].iov_len || addr != NULL) {
767 		unsigned int len = xdr->head[0].iov_len - base;
768 		remainder -= len;
769 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
770 		if (remainder == 0 || err != len)
771 			goto out;
772 		*sent_p += err;
773 		base = 0;
774 	} else
775 		base -= xdr->head[0].iov_len;
776 
777 	if (base < xdr->page_len) {
778 		unsigned int len = xdr->page_len - base;
779 		remainder -= len;
780 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
781 		*sent_p += sent;
782 		if (remainder == 0 || sent != len)
783 			goto out;
784 		base = 0;
785 	} else
786 		base -= xdr->page_len;
787 
788 	if (base >= xdr->tail[0].iov_len)
789 		return 0;
790 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
791 out:
792 	if (err > 0) {
793 		*sent_p += err;
794 		err = 0;
795 	}
796 	return err;
797 }
798 
799 /**
800  * xs_nospace - handle transmit was incomplete
801  * @req: pointer to RPC request
802  *
803  */
804 static int xs_nospace(struct rpc_rqst *req)
805 {
806 	struct rpc_xprt *xprt = req->rq_xprt;
807 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
808 	struct sock *sk = transport->inet;
809 	int ret = -EAGAIN;
810 
811 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
812 			req->rq_task->tk_pid,
813 			req->rq_slen - transport->xmit.offset,
814 			req->rq_slen);
815 
816 	/* Protect against races with write_space */
817 	spin_lock_bh(&xprt->transport_lock);
818 
819 	/* Don't race with disconnect */
820 	if (xprt_connected(xprt)) {
821 		/* wait for more buffer space */
822 		sk->sk_write_pending++;
823 		xprt_wait_for_buffer_space(xprt);
824 	} else
825 		ret = -ENOTCONN;
826 
827 	spin_unlock_bh(&xprt->transport_lock);
828 
829 	/* Race breaker in case memory is freed before above code is called */
830 	if (ret == -EAGAIN) {
831 		struct socket_wq *wq;
832 
833 		rcu_read_lock();
834 		wq = rcu_dereference(sk->sk_wq);
835 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
836 		rcu_read_unlock();
837 
838 		sk->sk_write_space(sk);
839 	}
840 	return ret;
841 }
842 
843 static void
844 xs_stream_prepare_request(struct rpc_rqst *req)
845 {
846 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_NOIO);
847 }
848 
849 /*
850  * Determine if the previous message in the stream was aborted before it
851  * could complete transmission.
852  */
853 static bool
854 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
855 {
856 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
857 }
858 
859 /*
860  * Construct a stream transport record marker in @buf.
861  */
862 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
863 {
864 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
865 	rpc_fraghdr *base = buf->head[0].iov_base;
866 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
867 }
868 
869 /**
870  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
871  * @req: pointer to RPC request
872  *
873  * Return values:
874  *        0:	The request has been sent
875  *   EAGAIN:	The socket was blocked, please call again later to
876  *		complete the request
877  * ENOTCONN:	Caller needs to invoke connect logic then call again
878  *    other:	Some other error occured, the request was not sent
879  */
880 static int xs_local_send_request(struct rpc_rqst *req)
881 {
882 	struct rpc_xprt *xprt = req->rq_xprt;
883 	struct sock_xprt *transport =
884 				container_of(xprt, struct sock_xprt, xprt);
885 	struct xdr_buf *xdr = &req->rq_snd_buf;
886 	int status;
887 	int sent = 0;
888 
889 	/* Close the stream if the previous transmission was incomplete */
890 	if (xs_send_request_was_aborted(transport, req)) {
891 		xs_close(xprt);
892 		return -ENOTCONN;
893 	}
894 
895 	xs_encode_stream_record_marker(&req->rq_snd_buf);
896 
897 	xs_pktdump("packet data:",
898 			req->rq_svec->iov_base, req->rq_svec->iov_len);
899 
900 	req->rq_xtime = ktime_get();
901 	status = xs_sendpages(transport->sock, NULL, 0, xdr,
902 			      transport->xmit.offset,
903 			      true, &sent);
904 	dprintk("RPC:       %s(%u) = %d\n",
905 			__func__, xdr->len - transport->xmit.offset, status);
906 
907 	if (status == -EAGAIN && sock_writeable(transport->inet))
908 		status = -ENOBUFS;
909 
910 	if (likely(sent > 0) || status == 0) {
911 		transport->xmit.offset += sent;
912 		req->rq_bytes_sent = transport->xmit.offset;
913 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
914 			req->rq_xmit_bytes_sent += transport->xmit.offset;
915 			req->rq_bytes_sent = 0;
916 			transport->xmit.offset = 0;
917 			return 0;
918 		}
919 		status = -EAGAIN;
920 	}
921 
922 	switch (status) {
923 	case -ENOBUFS:
924 		break;
925 	case -EAGAIN:
926 		status = xs_nospace(req);
927 		break;
928 	default:
929 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
930 			-status);
931 		/* fall through */
932 	case -EPIPE:
933 		xs_close(xprt);
934 		status = -ENOTCONN;
935 	}
936 
937 	return status;
938 }
939 
940 /**
941  * xs_udp_send_request - write an RPC request to a UDP socket
942  * @req: pointer to RPC request
943  *
944  * Return values:
945  *        0:	The request has been sent
946  *   EAGAIN:	The socket was blocked, please call again later to
947  *		complete the request
948  * ENOTCONN:	Caller needs to invoke connect logic then call again
949  *    other:	Some other error occurred, the request was not sent
950  */
951 static int xs_udp_send_request(struct rpc_rqst *req)
952 {
953 	struct rpc_xprt *xprt = req->rq_xprt;
954 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
955 	struct xdr_buf *xdr = &req->rq_snd_buf;
956 	int sent = 0;
957 	int status;
958 
959 	xs_pktdump("packet data:",
960 				req->rq_svec->iov_base,
961 				req->rq_svec->iov_len);
962 
963 	if (!xprt_bound(xprt))
964 		return -ENOTCONN;
965 
966 	if (!xprt_request_get_cong(xprt, req))
967 		return -EBADSLT;
968 
969 	req->rq_xtime = ktime_get();
970 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
971 			      xdr, 0, true, &sent);
972 
973 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
974 			xdr->len, status);
975 
976 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
977 	if (status == -EPERM)
978 		goto process_status;
979 
980 	if (status == -EAGAIN && sock_writeable(transport->inet))
981 		status = -ENOBUFS;
982 
983 	if (sent > 0 || status == 0) {
984 		req->rq_xmit_bytes_sent += sent;
985 		if (sent >= req->rq_slen)
986 			return 0;
987 		/* Still some bytes left; set up for a retry later. */
988 		status = -EAGAIN;
989 	}
990 
991 process_status:
992 	switch (status) {
993 	case -ENOTSOCK:
994 		status = -ENOTCONN;
995 		/* Should we call xs_close() here? */
996 		break;
997 	case -EAGAIN:
998 		status = xs_nospace(req);
999 		break;
1000 	case -ENETUNREACH:
1001 	case -ENOBUFS:
1002 	case -EPIPE:
1003 	case -ECONNREFUSED:
1004 	case -EPERM:
1005 		/* When the server has died, an ICMP port unreachable message
1006 		 * prompts ECONNREFUSED. */
1007 		break;
1008 	default:
1009 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1010 			-status);
1011 	}
1012 
1013 	return status;
1014 }
1015 
1016 /**
1017  * xs_tcp_send_request - write an RPC request to a TCP socket
1018  * @req: pointer to RPC request
1019  *
1020  * Return values:
1021  *        0:	The request has been sent
1022  *   EAGAIN:	The socket was blocked, please call again later to
1023  *		complete the request
1024  * ENOTCONN:	Caller needs to invoke connect logic then call again
1025  *    other:	Some other error occurred, the request was not sent
1026  *
1027  * XXX: In the case of soft timeouts, should we eventually give up
1028  *	if sendmsg is not able to make progress?
1029  */
1030 static int xs_tcp_send_request(struct rpc_rqst *req)
1031 {
1032 	struct rpc_xprt *xprt = req->rq_xprt;
1033 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1034 	struct xdr_buf *xdr = &req->rq_snd_buf;
1035 	bool zerocopy = true;
1036 	bool vm_wait = false;
1037 	int status;
1038 	int sent;
1039 
1040 	/* Close the stream if the previous transmission was incomplete */
1041 	if (xs_send_request_was_aborted(transport, req)) {
1042 		if (transport->sock != NULL)
1043 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1044 		return -ENOTCONN;
1045 	}
1046 
1047 	xs_encode_stream_record_marker(&req->rq_snd_buf);
1048 
1049 	xs_pktdump("packet data:",
1050 				req->rq_svec->iov_base,
1051 				req->rq_svec->iov_len);
1052 	/* Don't use zero copy if this is a resend. If the RPC call
1053 	 * completes while the socket holds a reference to the pages,
1054 	 * then we may end up resending corrupted data.
1055 	 */
1056 	if (req->rq_task->tk_flags & RPC_TASK_SENT)
1057 		zerocopy = false;
1058 
1059 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1060 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1061 
1062 	/* Continue transmitting the packet/record. We must be careful
1063 	 * to cope with writespace callbacks arriving _after_ we have
1064 	 * called sendmsg(). */
1065 	req->rq_xtime = ktime_get();
1066 	while (1) {
1067 		sent = 0;
1068 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
1069 				      transport->xmit.offset,
1070 				      zerocopy, &sent);
1071 
1072 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1073 				xdr->len - transport->xmit.offset, status);
1074 
1075 		/* If we've sent the entire packet, immediately
1076 		 * reset the count of bytes sent. */
1077 		transport->xmit.offset += sent;
1078 		req->rq_bytes_sent = transport->xmit.offset;
1079 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
1080 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1081 			req->rq_bytes_sent = 0;
1082 			transport->xmit.offset = 0;
1083 			return 0;
1084 		}
1085 
1086 		WARN_ON_ONCE(sent == 0 && status == 0);
1087 
1088 		if (status == -EAGAIN ) {
1089 			/*
1090 			 * Return EAGAIN if we're sure we're hitting the
1091 			 * socket send buffer limits.
1092 			 */
1093 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1094 				break;
1095 			/*
1096 			 * Did we hit a memory allocation failure?
1097 			 */
1098 			if (sent == 0) {
1099 				status = -ENOBUFS;
1100 				if (vm_wait)
1101 					break;
1102 				/* Retry, knowing now that we're below the
1103 				 * socket send buffer limit
1104 				 */
1105 				vm_wait = true;
1106 			}
1107 			continue;
1108 		}
1109 		if (status < 0)
1110 			break;
1111 		vm_wait = false;
1112 	}
1113 
1114 	switch (status) {
1115 	case -ENOTSOCK:
1116 		status = -ENOTCONN;
1117 		/* Should we call xs_close() here? */
1118 		break;
1119 	case -EAGAIN:
1120 		status = xs_nospace(req);
1121 		break;
1122 	case -ECONNRESET:
1123 	case -ECONNREFUSED:
1124 	case -ENOTCONN:
1125 	case -EADDRINUSE:
1126 	case -ENOBUFS:
1127 	case -EPIPE:
1128 		break;
1129 	default:
1130 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1131 			-status);
1132 	}
1133 
1134 	return status;
1135 }
1136 
1137 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1138 {
1139 	transport->old_data_ready = sk->sk_data_ready;
1140 	transport->old_state_change = sk->sk_state_change;
1141 	transport->old_write_space = sk->sk_write_space;
1142 	transport->old_error_report = sk->sk_error_report;
1143 }
1144 
1145 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1146 {
1147 	sk->sk_data_ready = transport->old_data_ready;
1148 	sk->sk_state_change = transport->old_state_change;
1149 	sk->sk_write_space = transport->old_write_space;
1150 	sk->sk_error_report = transport->old_error_report;
1151 }
1152 
1153 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1154 {
1155 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1156 
1157 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1158 }
1159 
1160 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1161 {
1162 	smp_mb__before_atomic();
1163 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1164 	clear_bit(XPRT_CLOSING, &xprt->state);
1165 	xs_sock_reset_state_flags(xprt);
1166 	smp_mb__after_atomic();
1167 }
1168 
1169 /**
1170  * xs_error_report - callback to handle TCP socket state errors
1171  * @sk: socket
1172  *
1173  * Note: we don't call sock_error() since there may be a rpc_task
1174  * using the socket, and so we don't want to clear sk->sk_err.
1175  */
1176 static void xs_error_report(struct sock *sk)
1177 {
1178 	struct rpc_xprt *xprt;
1179 	int err;
1180 
1181 	read_lock_bh(&sk->sk_callback_lock);
1182 	if (!(xprt = xprt_from_sock(sk)))
1183 		goto out;
1184 
1185 	err = -sk->sk_err;
1186 	if (err == 0)
1187 		goto out;
1188 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1189 			xprt, -err);
1190 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
1191 	xprt_wake_pending_tasks(xprt, err);
1192  out:
1193 	read_unlock_bh(&sk->sk_callback_lock);
1194 }
1195 
1196 static void xs_reset_transport(struct sock_xprt *transport)
1197 {
1198 	struct socket *sock = transport->sock;
1199 	struct sock *sk = transport->inet;
1200 	struct rpc_xprt *xprt = &transport->xprt;
1201 
1202 	if (sk == NULL)
1203 		return;
1204 
1205 	if (atomic_read(&transport->xprt.swapper))
1206 		sk_clear_memalloc(sk);
1207 
1208 	kernel_sock_shutdown(sock, SHUT_RDWR);
1209 
1210 	mutex_lock(&transport->recv_mutex);
1211 	write_lock_bh(&sk->sk_callback_lock);
1212 	transport->inet = NULL;
1213 	transport->sock = NULL;
1214 
1215 	sk->sk_user_data = NULL;
1216 
1217 	xs_restore_old_callbacks(transport, sk);
1218 	xprt_clear_connected(xprt);
1219 	write_unlock_bh(&sk->sk_callback_lock);
1220 	xs_sock_reset_connection_flags(xprt);
1221 	mutex_unlock(&transport->recv_mutex);
1222 
1223 	trace_rpc_socket_close(xprt, sock);
1224 	sock_release(sock);
1225 }
1226 
1227 /**
1228  * xs_close - close a socket
1229  * @xprt: transport
1230  *
1231  * This is used when all requests are complete; ie, no DRC state remains
1232  * on the server we want to save.
1233  *
1234  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1235  * xs_reset_transport() zeroing the socket from underneath a writer.
1236  */
1237 static void xs_close(struct rpc_xprt *xprt)
1238 {
1239 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1240 
1241 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1242 
1243 	xs_reset_transport(transport);
1244 	xprt->reestablish_timeout = 0;
1245 
1246 	xprt_disconnect_done(xprt);
1247 }
1248 
1249 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1250 {
1251 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1252 		xprt);
1253 	xprt_disconnect_done(xprt);
1254 }
1255 
1256 static void xs_xprt_free(struct rpc_xprt *xprt)
1257 {
1258 	xs_free_peer_addresses(xprt);
1259 	xprt_free(xprt);
1260 }
1261 
1262 /**
1263  * xs_destroy - prepare to shutdown a transport
1264  * @xprt: doomed transport
1265  *
1266  */
1267 static void xs_destroy(struct rpc_xprt *xprt)
1268 {
1269 	struct sock_xprt *transport = container_of(xprt,
1270 			struct sock_xprt, xprt);
1271 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1272 
1273 	cancel_delayed_work_sync(&transport->connect_worker);
1274 	xs_close(xprt);
1275 	cancel_work_sync(&transport->recv_worker);
1276 	xs_xprt_free(xprt);
1277 	module_put(THIS_MODULE);
1278 }
1279 
1280 /**
1281  * xs_udp_data_read_skb - receive callback for UDP sockets
1282  * @xprt: transport
1283  * @sk: socket
1284  * @skb: skbuff
1285  *
1286  */
1287 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1288 		struct sock *sk,
1289 		struct sk_buff *skb)
1290 {
1291 	struct rpc_task *task;
1292 	struct rpc_rqst *rovr;
1293 	int repsize, copied;
1294 	u32 _xid;
1295 	__be32 *xp;
1296 
1297 	repsize = skb->len;
1298 	if (repsize < 4) {
1299 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1300 		return;
1301 	}
1302 
1303 	/* Copy the XID from the skb... */
1304 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1305 	if (xp == NULL)
1306 		return;
1307 
1308 	/* Look up and lock the request corresponding to the given XID */
1309 	spin_lock(&xprt->queue_lock);
1310 	rovr = xprt_lookup_rqst(xprt, *xp);
1311 	if (!rovr)
1312 		goto out_unlock;
1313 	xprt_pin_rqst(rovr);
1314 	xprt_update_rtt(rovr->rq_task);
1315 	spin_unlock(&xprt->queue_lock);
1316 	task = rovr->rq_task;
1317 
1318 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1319 		copied = repsize;
1320 
1321 	/* Suck it into the iovec, verify checksum if not done by hw. */
1322 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1323 		spin_lock(&xprt->queue_lock);
1324 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1325 		goto out_unpin;
1326 	}
1327 
1328 
1329 	spin_lock_bh(&xprt->transport_lock);
1330 	xprt_adjust_cwnd(xprt, task, copied);
1331 	spin_unlock_bh(&xprt->transport_lock);
1332 	spin_lock(&xprt->queue_lock);
1333 	xprt_complete_rqst(task, copied);
1334 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1335 out_unpin:
1336 	xprt_unpin_rqst(rovr);
1337  out_unlock:
1338 	spin_unlock(&xprt->queue_lock);
1339 }
1340 
1341 static void xs_udp_data_receive(struct sock_xprt *transport)
1342 {
1343 	struct sk_buff *skb;
1344 	struct sock *sk;
1345 	int err;
1346 
1347 	mutex_lock(&transport->recv_mutex);
1348 	sk = transport->inet;
1349 	if (sk == NULL)
1350 		goto out;
1351 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1352 	for (;;) {
1353 		skb = skb_recv_udp(sk, 0, 1, &err);
1354 		if (skb == NULL)
1355 			break;
1356 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1357 		consume_skb(skb);
1358 		cond_resched();
1359 	}
1360 out:
1361 	mutex_unlock(&transport->recv_mutex);
1362 }
1363 
1364 static void xs_udp_data_receive_workfn(struct work_struct *work)
1365 {
1366 	struct sock_xprt *transport =
1367 		container_of(work, struct sock_xprt, recv_worker);
1368 	xs_udp_data_receive(transport);
1369 }
1370 
1371 /**
1372  * xs_data_ready - "data ready" callback for UDP sockets
1373  * @sk: socket with data to read
1374  *
1375  */
1376 static void xs_data_ready(struct sock *sk)
1377 {
1378 	struct rpc_xprt *xprt;
1379 
1380 	read_lock_bh(&sk->sk_callback_lock);
1381 	dprintk("RPC:       xs_data_ready...\n");
1382 	xprt = xprt_from_sock(sk);
1383 	if (xprt != NULL) {
1384 		struct sock_xprt *transport = container_of(xprt,
1385 				struct sock_xprt, xprt);
1386 		transport->old_data_ready(sk);
1387 		/* Any data means we had a useful conversation, so
1388 		 * then we don't need to delay the next reconnect
1389 		 */
1390 		if (xprt->reestablish_timeout)
1391 			xprt->reestablish_timeout = 0;
1392 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1393 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1394 	}
1395 	read_unlock_bh(&sk->sk_callback_lock);
1396 }
1397 
1398 /*
1399  * Helper function to force a TCP close if the server is sending
1400  * junk and/or it has put us in CLOSE_WAIT
1401  */
1402 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1403 {
1404 	xprt_force_disconnect(xprt);
1405 }
1406 
1407 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1408 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1409 {
1410 	int ret;
1411 
1412 	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1413 			      SVC_SOCK_ANONYMOUS);
1414 	if (ret < 0)
1415 		return ret;
1416 	return 0;
1417 }
1418 
1419 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1420 {
1421 	return PAGE_SIZE;
1422 }
1423 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1424 
1425 /**
1426  * xs_tcp_state_change - callback to handle TCP socket state changes
1427  * @sk: socket whose state has changed
1428  *
1429  */
1430 static void xs_tcp_state_change(struct sock *sk)
1431 {
1432 	struct rpc_xprt *xprt;
1433 	struct sock_xprt *transport;
1434 
1435 	read_lock_bh(&sk->sk_callback_lock);
1436 	if (!(xprt = xprt_from_sock(sk)))
1437 		goto out;
1438 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1439 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1440 			sk->sk_state, xprt_connected(xprt),
1441 			sock_flag(sk, SOCK_DEAD),
1442 			sock_flag(sk, SOCK_ZAPPED),
1443 			sk->sk_shutdown);
1444 
1445 	transport = container_of(xprt, struct sock_xprt, xprt);
1446 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1447 	switch (sk->sk_state) {
1448 	case TCP_ESTABLISHED:
1449 		spin_lock(&xprt->transport_lock);
1450 		if (!xprt_test_and_set_connected(xprt)) {
1451 			xprt->connect_cookie++;
1452 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1453 			xprt_clear_connecting(xprt);
1454 
1455 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1456 		}
1457 		spin_unlock(&xprt->transport_lock);
1458 		break;
1459 	case TCP_FIN_WAIT1:
1460 		/* The client initiated a shutdown of the socket */
1461 		xprt->connect_cookie++;
1462 		xprt->reestablish_timeout = 0;
1463 		set_bit(XPRT_CLOSING, &xprt->state);
1464 		smp_mb__before_atomic();
1465 		clear_bit(XPRT_CONNECTED, &xprt->state);
1466 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1467 		smp_mb__after_atomic();
1468 		break;
1469 	case TCP_CLOSE_WAIT:
1470 		/* The server initiated a shutdown of the socket */
1471 		xprt->connect_cookie++;
1472 		clear_bit(XPRT_CONNECTED, &xprt->state);
1473 		xs_tcp_force_close(xprt);
1474 		/* fall through */
1475 	case TCP_CLOSING:
1476 		/*
1477 		 * If the server closed down the connection, make sure that
1478 		 * we back off before reconnecting
1479 		 */
1480 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1481 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1482 		break;
1483 	case TCP_LAST_ACK:
1484 		set_bit(XPRT_CLOSING, &xprt->state);
1485 		smp_mb__before_atomic();
1486 		clear_bit(XPRT_CONNECTED, &xprt->state);
1487 		smp_mb__after_atomic();
1488 		break;
1489 	case TCP_CLOSE:
1490 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1491 					&transport->sock_state))
1492 			xprt_clear_connecting(xprt);
1493 		clear_bit(XPRT_CLOSING, &xprt->state);
1494 		if (sk->sk_err)
1495 			xprt_wake_pending_tasks(xprt, -sk->sk_err);
1496 		/* Trigger the socket release */
1497 		xs_tcp_force_close(xprt);
1498 	}
1499  out:
1500 	read_unlock_bh(&sk->sk_callback_lock);
1501 }
1502 
1503 static void xs_write_space(struct sock *sk)
1504 {
1505 	struct socket_wq *wq;
1506 	struct rpc_xprt *xprt;
1507 
1508 	if (!sk->sk_socket)
1509 		return;
1510 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1511 
1512 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1513 		return;
1514 	rcu_read_lock();
1515 	wq = rcu_dereference(sk->sk_wq);
1516 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1517 		goto out;
1518 
1519 	if (xprt_write_space(xprt))
1520 		sk->sk_write_pending--;
1521 out:
1522 	rcu_read_unlock();
1523 }
1524 
1525 /**
1526  * xs_udp_write_space - callback invoked when socket buffer space
1527  *                             becomes available
1528  * @sk: socket whose state has changed
1529  *
1530  * Called when more output buffer space is available for this socket.
1531  * We try not to wake our writers until they can make "significant"
1532  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1533  * with a bunch of small requests.
1534  */
1535 static void xs_udp_write_space(struct sock *sk)
1536 {
1537 	read_lock_bh(&sk->sk_callback_lock);
1538 
1539 	/* from net/core/sock.c:sock_def_write_space */
1540 	if (sock_writeable(sk))
1541 		xs_write_space(sk);
1542 
1543 	read_unlock_bh(&sk->sk_callback_lock);
1544 }
1545 
1546 /**
1547  * xs_tcp_write_space - callback invoked when socket buffer space
1548  *                             becomes available
1549  * @sk: socket whose state has changed
1550  *
1551  * Called when more output buffer space is available for this socket.
1552  * We try not to wake our writers until they can make "significant"
1553  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1554  * with a bunch of small requests.
1555  */
1556 static void xs_tcp_write_space(struct sock *sk)
1557 {
1558 	read_lock_bh(&sk->sk_callback_lock);
1559 
1560 	/* from net/core/stream.c:sk_stream_write_space */
1561 	if (sk_stream_is_writeable(sk))
1562 		xs_write_space(sk);
1563 
1564 	read_unlock_bh(&sk->sk_callback_lock);
1565 }
1566 
1567 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1568 {
1569 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1570 	struct sock *sk = transport->inet;
1571 
1572 	if (transport->rcvsize) {
1573 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1574 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1575 	}
1576 	if (transport->sndsize) {
1577 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1578 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1579 		sk->sk_write_space(sk);
1580 	}
1581 }
1582 
1583 /**
1584  * xs_udp_set_buffer_size - set send and receive limits
1585  * @xprt: generic transport
1586  * @sndsize: requested size of send buffer, in bytes
1587  * @rcvsize: requested size of receive buffer, in bytes
1588  *
1589  * Set socket send and receive buffer size limits.
1590  */
1591 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1592 {
1593 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1594 
1595 	transport->sndsize = 0;
1596 	if (sndsize)
1597 		transport->sndsize = sndsize + 1024;
1598 	transport->rcvsize = 0;
1599 	if (rcvsize)
1600 		transport->rcvsize = rcvsize + 1024;
1601 
1602 	xs_udp_do_set_buffer_size(xprt);
1603 }
1604 
1605 /**
1606  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1607  * @task: task that timed out
1608  *
1609  * Adjust the congestion window after a retransmit timeout has occurred.
1610  */
1611 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1612 {
1613 	spin_lock_bh(&xprt->transport_lock);
1614 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1615 	spin_unlock_bh(&xprt->transport_lock);
1616 }
1617 
1618 static unsigned short xs_get_random_port(void)
1619 {
1620 	unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
1621 	unsigned short rand = (unsigned short) prandom_u32() % range;
1622 	return rand + xprt_min_resvport;
1623 }
1624 
1625 /**
1626  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1627  * @sock: socket
1628  *
1629  * Note that this function has to be called on all sockets that share the
1630  * same port, and it must be called before binding.
1631  */
1632 static void xs_sock_set_reuseport(struct socket *sock)
1633 {
1634 	int opt = 1;
1635 
1636 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1637 			(char *)&opt, sizeof(opt));
1638 }
1639 
1640 static unsigned short xs_sock_getport(struct socket *sock)
1641 {
1642 	struct sockaddr_storage buf;
1643 	unsigned short port = 0;
1644 
1645 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1646 		goto out;
1647 	switch (buf.ss_family) {
1648 	case AF_INET6:
1649 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1650 		break;
1651 	case AF_INET:
1652 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1653 	}
1654 out:
1655 	return port;
1656 }
1657 
1658 /**
1659  * xs_set_port - reset the port number in the remote endpoint address
1660  * @xprt: generic transport
1661  * @port: new port number
1662  *
1663  */
1664 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1665 {
1666 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1667 
1668 	rpc_set_port(xs_addr(xprt), port);
1669 	xs_update_peer_port(xprt);
1670 }
1671 
1672 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1673 {
1674 	if (transport->srcport == 0)
1675 		transport->srcport = xs_sock_getport(sock);
1676 }
1677 
1678 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1679 {
1680 	unsigned short port = transport->srcport;
1681 
1682 	if (port == 0 && transport->xprt.resvport)
1683 		port = xs_get_random_port();
1684 	return port;
1685 }
1686 
1687 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1688 {
1689 	if (transport->srcport != 0)
1690 		transport->srcport = 0;
1691 	if (!transport->xprt.resvport)
1692 		return 0;
1693 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1694 		return xprt_max_resvport;
1695 	return --port;
1696 }
1697 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1698 {
1699 	struct sockaddr_storage myaddr;
1700 	int err, nloop = 0;
1701 	unsigned short port = xs_get_srcport(transport);
1702 	unsigned short last;
1703 
1704 	/*
1705 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1706 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1707 	 * port selection happen implicitly when the socket is used
1708 	 * (for example at connect time).
1709 	 *
1710 	 * This ensures that we can continue to establish TCP
1711 	 * connections even when all local ephemeral ports are already
1712 	 * a part of some TCP connection.  This makes no difference
1713 	 * for UDP sockets, but also doens't harm them.
1714 	 *
1715 	 * If we're asking for any reserved port (i.e. port == 0 &&
1716 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1717 	 * ensure that port is non-zero and we will bind as needed.
1718 	 */
1719 	if (port == 0)
1720 		return 0;
1721 
1722 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1723 	do {
1724 		rpc_set_port((struct sockaddr *)&myaddr, port);
1725 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1726 				transport->xprt.addrlen);
1727 		if (err == 0) {
1728 			transport->srcport = port;
1729 			break;
1730 		}
1731 		last = port;
1732 		port = xs_next_srcport(transport, port);
1733 		if (port > last)
1734 			nloop++;
1735 	} while (err == -EADDRINUSE && nloop != 2);
1736 
1737 	if (myaddr.ss_family == AF_INET)
1738 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1739 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1740 				port, err ? "failed" : "ok", err);
1741 	else
1742 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1743 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1744 				port, err ? "failed" : "ok", err);
1745 	return err;
1746 }
1747 
1748 /*
1749  * We don't support autobind on AF_LOCAL sockets
1750  */
1751 static void xs_local_rpcbind(struct rpc_task *task)
1752 {
1753 	xprt_set_bound(task->tk_xprt);
1754 }
1755 
1756 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1757 {
1758 }
1759 
1760 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1761 static struct lock_class_key xs_key[2];
1762 static struct lock_class_key xs_slock_key[2];
1763 
1764 static inline void xs_reclassify_socketu(struct socket *sock)
1765 {
1766 	struct sock *sk = sock->sk;
1767 
1768 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1769 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1770 }
1771 
1772 static inline void xs_reclassify_socket4(struct socket *sock)
1773 {
1774 	struct sock *sk = sock->sk;
1775 
1776 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1777 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1778 }
1779 
1780 static inline void xs_reclassify_socket6(struct socket *sock)
1781 {
1782 	struct sock *sk = sock->sk;
1783 
1784 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1785 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1786 }
1787 
1788 static inline void xs_reclassify_socket(int family, struct socket *sock)
1789 {
1790 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1791 		return;
1792 
1793 	switch (family) {
1794 	case AF_LOCAL:
1795 		xs_reclassify_socketu(sock);
1796 		break;
1797 	case AF_INET:
1798 		xs_reclassify_socket4(sock);
1799 		break;
1800 	case AF_INET6:
1801 		xs_reclassify_socket6(sock);
1802 		break;
1803 	}
1804 }
1805 #else
1806 static inline void xs_reclassify_socket(int family, struct socket *sock)
1807 {
1808 }
1809 #endif
1810 
1811 static void xs_dummy_setup_socket(struct work_struct *work)
1812 {
1813 }
1814 
1815 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1816 		struct sock_xprt *transport, int family, int type,
1817 		int protocol, bool reuseport)
1818 {
1819 	struct socket *sock;
1820 	int err;
1821 
1822 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1823 	if (err < 0) {
1824 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1825 				protocol, -err);
1826 		goto out;
1827 	}
1828 	xs_reclassify_socket(family, sock);
1829 
1830 	if (reuseport)
1831 		xs_sock_set_reuseport(sock);
1832 
1833 	err = xs_bind(transport, sock);
1834 	if (err) {
1835 		sock_release(sock);
1836 		goto out;
1837 	}
1838 
1839 	return sock;
1840 out:
1841 	return ERR_PTR(err);
1842 }
1843 
1844 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1845 				      struct socket *sock)
1846 {
1847 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1848 									xprt);
1849 
1850 	if (!transport->inet) {
1851 		struct sock *sk = sock->sk;
1852 
1853 		write_lock_bh(&sk->sk_callback_lock);
1854 
1855 		xs_save_old_callbacks(transport, sk);
1856 
1857 		sk->sk_user_data = xprt;
1858 		sk->sk_data_ready = xs_data_ready;
1859 		sk->sk_write_space = xs_udp_write_space;
1860 		sock_set_flag(sk, SOCK_FASYNC);
1861 		sk->sk_error_report = xs_error_report;
1862 		sk->sk_allocation = GFP_NOIO;
1863 
1864 		xprt_clear_connected(xprt);
1865 
1866 		/* Reset to new socket */
1867 		transport->sock = sock;
1868 		transport->inet = sk;
1869 
1870 		write_unlock_bh(&sk->sk_callback_lock);
1871 	}
1872 
1873 	xs_stream_reset_connect(transport);
1874 
1875 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1876 }
1877 
1878 /**
1879  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1880  * @transport: socket transport to connect
1881  */
1882 static int xs_local_setup_socket(struct sock_xprt *transport)
1883 {
1884 	struct rpc_xprt *xprt = &transport->xprt;
1885 	struct socket *sock;
1886 	int status = -EIO;
1887 
1888 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1889 					SOCK_STREAM, 0, &sock, 1);
1890 	if (status < 0) {
1891 		dprintk("RPC:       can't create AF_LOCAL "
1892 			"transport socket (%d).\n", -status);
1893 		goto out;
1894 	}
1895 	xs_reclassify_socket(AF_LOCAL, sock);
1896 
1897 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1898 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1899 
1900 	status = xs_local_finish_connecting(xprt, sock);
1901 	trace_rpc_socket_connect(xprt, sock, status);
1902 	switch (status) {
1903 	case 0:
1904 		dprintk("RPC:       xprt %p connected to %s\n",
1905 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1906 		xprt_set_connected(xprt);
1907 	case -ENOBUFS:
1908 		break;
1909 	case -ENOENT:
1910 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1911 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1912 		break;
1913 	case -ECONNREFUSED:
1914 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1915 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1916 		break;
1917 	default:
1918 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1919 				__func__, -status,
1920 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1921 	}
1922 
1923 out:
1924 	xprt_clear_connecting(xprt);
1925 	xprt_wake_pending_tasks(xprt, status);
1926 	return status;
1927 }
1928 
1929 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1930 {
1931 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1932 	int ret;
1933 
1934 	 if (RPC_IS_ASYNC(task)) {
1935 		/*
1936 		 * We want the AF_LOCAL connect to be resolved in the
1937 		 * filesystem namespace of the process making the rpc
1938 		 * call.  Thus we connect synchronously.
1939 		 *
1940 		 * If we want to support asynchronous AF_LOCAL calls,
1941 		 * we'll need to figure out how to pass a namespace to
1942 		 * connect.
1943 		 */
1944 		rpc_exit(task, -ENOTCONN);
1945 		return;
1946 	}
1947 	ret = xs_local_setup_socket(transport);
1948 	if (ret && !RPC_IS_SOFTCONN(task))
1949 		msleep_interruptible(15000);
1950 }
1951 
1952 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1953 /*
1954  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1955  * know that we have exclusive access to the socket), to guard against
1956  * races with xs_reset_transport.
1957  */
1958 static void xs_set_memalloc(struct rpc_xprt *xprt)
1959 {
1960 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1961 			xprt);
1962 
1963 	/*
1964 	 * If there's no sock, then we have nothing to set. The
1965 	 * reconnecting process will get it for us.
1966 	 */
1967 	if (!transport->inet)
1968 		return;
1969 	if (atomic_read(&xprt->swapper))
1970 		sk_set_memalloc(transport->inet);
1971 }
1972 
1973 /**
1974  * xs_enable_swap - Tag this transport as being used for swap.
1975  * @xprt: transport to tag
1976  *
1977  * Take a reference to this transport on behalf of the rpc_clnt, and
1978  * optionally mark it for swapping if it wasn't already.
1979  */
1980 static int
1981 xs_enable_swap(struct rpc_xprt *xprt)
1982 {
1983 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1984 
1985 	if (atomic_inc_return(&xprt->swapper) != 1)
1986 		return 0;
1987 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1988 		return -ERESTARTSYS;
1989 	if (xs->inet)
1990 		sk_set_memalloc(xs->inet);
1991 	xprt_release_xprt(xprt, NULL);
1992 	return 0;
1993 }
1994 
1995 /**
1996  * xs_disable_swap - Untag this transport as being used for swap.
1997  * @xprt: transport to tag
1998  *
1999  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2000  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2001  */
2002 static void
2003 xs_disable_swap(struct rpc_xprt *xprt)
2004 {
2005 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2006 
2007 	if (!atomic_dec_and_test(&xprt->swapper))
2008 		return;
2009 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2010 		return;
2011 	if (xs->inet)
2012 		sk_clear_memalloc(xs->inet);
2013 	xprt_release_xprt(xprt, NULL);
2014 }
2015 #else
2016 static void xs_set_memalloc(struct rpc_xprt *xprt)
2017 {
2018 }
2019 
2020 static int
2021 xs_enable_swap(struct rpc_xprt *xprt)
2022 {
2023 	return -EINVAL;
2024 }
2025 
2026 static void
2027 xs_disable_swap(struct rpc_xprt *xprt)
2028 {
2029 }
2030 #endif
2031 
2032 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2033 {
2034 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2035 
2036 	if (!transport->inet) {
2037 		struct sock *sk = sock->sk;
2038 
2039 		write_lock_bh(&sk->sk_callback_lock);
2040 
2041 		xs_save_old_callbacks(transport, sk);
2042 
2043 		sk->sk_user_data = xprt;
2044 		sk->sk_data_ready = xs_data_ready;
2045 		sk->sk_write_space = xs_udp_write_space;
2046 		sock_set_flag(sk, SOCK_FASYNC);
2047 		sk->sk_allocation = GFP_NOIO;
2048 
2049 		xprt_set_connected(xprt);
2050 
2051 		/* Reset to new socket */
2052 		transport->sock = sock;
2053 		transport->inet = sk;
2054 
2055 		xs_set_memalloc(xprt);
2056 
2057 		write_unlock_bh(&sk->sk_callback_lock);
2058 	}
2059 	xs_udp_do_set_buffer_size(xprt);
2060 
2061 	xprt->stat.connect_start = jiffies;
2062 }
2063 
2064 static void xs_udp_setup_socket(struct work_struct *work)
2065 {
2066 	struct sock_xprt *transport =
2067 		container_of(work, struct sock_xprt, connect_worker.work);
2068 	struct rpc_xprt *xprt = &transport->xprt;
2069 	struct socket *sock;
2070 	int status = -EIO;
2071 
2072 	sock = xs_create_sock(xprt, transport,
2073 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2074 			IPPROTO_UDP, false);
2075 	if (IS_ERR(sock))
2076 		goto out;
2077 
2078 	dprintk("RPC:       worker connecting xprt %p via %s to "
2079 				"%s (port %s)\n", xprt,
2080 			xprt->address_strings[RPC_DISPLAY_PROTO],
2081 			xprt->address_strings[RPC_DISPLAY_ADDR],
2082 			xprt->address_strings[RPC_DISPLAY_PORT]);
2083 
2084 	xs_udp_finish_connecting(xprt, sock);
2085 	trace_rpc_socket_connect(xprt, sock, 0);
2086 	status = 0;
2087 out:
2088 	xprt_unlock_connect(xprt, transport);
2089 	xprt_clear_connecting(xprt);
2090 	xprt_wake_pending_tasks(xprt, status);
2091 }
2092 
2093 /**
2094  * xs_tcp_shutdown - gracefully shut down a TCP socket
2095  * @xprt: transport
2096  *
2097  * Initiates a graceful shutdown of the TCP socket by calling the
2098  * equivalent of shutdown(SHUT_RDWR);
2099  */
2100 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2101 {
2102 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2103 	struct socket *sock = transport->sock;
2104 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2105 
2106 	if (sock == NULL)
2107 		return;
2108 	switch (skst) {
2109 	default:
2110 		kernel_sock_shutdown(sock, SHUT_RDWR);
2111 		trace_rpc_socket_shutdown(xprt, sock);
2112 		break;
2113 	case TCP_CLOSE:
2114 	case TCP_TIME_WAIT:
2115 		xs_reset_transport(transport);
2116 	}
2117 }
2118 
2119 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2120 		struct socket *sock)
2121 {
2122 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2123 	unsigned int keepidle;
2124 	unsigned int keepcnt;
2125 	unsigned int opt_on = 1;
2126 	unsigned int timeo;
2127 
2128 	spin_lock_bh(&xprt->transport_lock);
2129 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2130 	keepcnt = xprt->timeout->to_retries + 1;
2131 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2132 		(xprt->timeout->to_retries + 1);
2133 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2134 	spin_unlock_bh(&xprt->transport_lock);
2135 
2136 	/* TCP Keepalive options */
2137 	kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2138 			(char *)&opt_on, sizeof(opt_on));
2139 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2140 			(char *)&keepidle, sizeof(keepidle));
2141 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2142 			(char *)&keepidle, sizeof(keepidle));
2143 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2144 			(char *)&keepcnt, sizeof(keepcnt));
2145 
2146 	/* TCP user timeout (see RFC5482) */
2147 	kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2148 			(char *)&timeo, sizeof(timeo));
2149 }
2150 
2151 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2152 		unsigned long connect_timeout,
2153 		unsigned long reconnect_timeout)
2154 {
2155 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2156 	struct rpc_timeout to;
2157 	unsigned long initval;
2158 
2159 	spin_lock_bh(&xprt->transport_lock);
2160 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2161 		xprt->max_reconnect_timeout = reconnect_timeout;
2162 	if (connect_timeout < xprt->connect_timeout) {
2163 		memcpy(&to, xprt->timeout, sizeof(to));
2164 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2165 		/* Arbitrary lower limit */
2166 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2167 			initval = XS_TCP_INIT_REEST_TO << 1;
2168 		to.to_initval = initval;
2169 		to.to_maxval = initval;
2170 		memcpy(&transport->tcp_timeout, &to,
2171 				sizeof(transport->tcp_timeout));
2172 		xprt->timeout = &transport->tcp_timeout;
2173 		xprt->connect_timeout = connect_timeout;
2174 	}
2175 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2176 	spin_unlock_bh(&xprt->transport_lock);
2177 }
2178 
2179 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2180 {
2181 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2182 	int ret = -ENOTCONN;
2183 
2184 	if (!transport->inet) {
2185 		struct sock *sk = sock->sk;
2186 		unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2187 
2188 		/* Avoid temporary address, they are bad for long-lived
2189 		 * connections such as NFS mounts.
2190 		 * RFC4941, section 3.6 suggests that:
2191 		 *    Individual applications, which have specific
2192 		 *    knowledge about the normal duration of connections,
2193 		 *    MAY override this as appropriate.
2194 		 */
2195 		kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2196 				(char *)&addr_pref, sizeof(addr_pref));
2197 
2198 		xs_tcp_set_socket_timeouts(xprt, sock);
2199 
2200 		write_lock_bh(&sk->sk_callback_lock);
2201 
2202 		xs_save_old_callbacks(transport, sk);
2203 
2204 		sk->sk_user_data = xprt;
2205 		sk->sk_data_ready = xs_data_ready;
2206 		sk->sk_state_change = xs_tcp_state_change;
2207 		sk->sk_write_space = xs_tcp_write_space;
2208 		sock_set_flag(sk, SOCK_FASYNC);
2209 		sk->sk_error_report = xs_error_report;
2210 		sk->sk_allocation = GFP_NOIO;
2211 
2212 		/* socket options */
2213 		sock_reset_flag(sk, SOCK_LINGER);
2214 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2215 
2216 		xprt_clear_connected(xprt);
2217 
2218 		/* Reset to new socket */
2219 		transport->sock = sock;
2220 		transport->inet = sk;
2221 
2222 		write_unlock_bh(&sk->sk_callback_lock);
2223 	}
2224 
2225 	if (!xprt_bound(xprt))
2226 		goto out;
2227 
2228 	xs_set_memalloc(xprt);
2229 
2230 	/* Reset TCP record info */
2231 	xs_stream_reset_connect(transport);
2232 
2233 	/* Tell the socket layer to start connecting... */
2234 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2235 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2236 	switch (ret) {
2237 	case 0:
2238 		xs_set_srcport(transport, sock);
2239 		/* fall through */
2240 	case -EINPROGRESS:
2241 		/* SYN_SENT! */
2242 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2243 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2244 		break;
2245 	case -EADDRNOTAVAIL:
2246 		/* Source port number is unavailable. Try a new one! */
2247 		transport->srcport = 0;
2248 	}
2249 out:
2250 	return ret;
2251 }
2252 
2253 /**
2254  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2255  *
2256  * Invoked by a work queue tasklet.
2257  */
2258 static void xs_tcp_setup_socket(struct work_struct *work)
2259 {
2260 	struct sock_xprt *transport =
2261 		container_of(work, struct sock_xprt, connect_worker.work);
2262 	struct socket *sock = transport->sock;
2263 	struct rpc_xprt *xprt = &transport->xprt;
2264 	int status = -EIO;
2265 
2266 	if (!sock) {
2267 		sock = xs_create_sock(xprt, transport,
2268 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2269 				IPPROTO_TCP, true);
2270 		if (IS_ERR(sock)) {
2271 			status = PTR_ERR(sock);
2272 			goto out;
2273 		}
2274 	}
2275 
2276 	dprintk("RPC:       worker connecting xprt %p via %s to "
2277 				"%s (port %s)\n", xprt,
2278 			xprt->address_strings[RPC_DISPLAY_PROTO],
2279 			xprt->address_strings[RPC_DISPLAY_ADDR],
2280 			xprt->address_strings[RPC_DISPLAY_PORT]);
2281 
2282 	status = xs_tcp_finish_connecting(xprt, sock);
2283 	trace_rpc_socket_connect(xprt, sock, status);
2284 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2285 			xprt, -status, xprt_connected(xprt),
2286 			sock->sk->sk_state);
2287 	switch (status) {
2288 	default:
2289 		printk("%s: connect returned unhandled error %d\n",
2290 			__func__, status);
2291 		/* fall through */
2292 	case -EADDRNOTAVAIL:
2293 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2294 		 * and retry
2295 		 */
2296 		xs_tcp_force_close(xprt);
2297 		break;
2298 	case 0:
2299 	case -EINPROGRESS:
2300 	case -EALREADY:
2301 		xprt_unlock_connect(xprt, transport);
2302 		return;
2303 	case -EINVAL:
2304 		/* Happens, for instance, if the user specified a link
2305 		 * local IPv6 address without a scope-id.
2306 		 */
2307 	case -ECONNREFUSED:
2308 	case -ECONNRESET:
2309 	case -ENETDOWN:
2310 	case -ENETUNREACH:
2311 	case -EHOSTUNREACH:
2312 	case -EADDRINUSE:
2313 	case -ENOBUFS:
2314 		/*
2315 		 * xs_tcp_force_close() wakes tasks with -EIO.
2316 		 * We need to wake them first to ensure the
2317 		 * correct error code.
2318 		 */
2319 		xprt_wake_pending_tasks(xprt, status);
2320 		xs_tcp_force_close(xprt);
2321 		goto out;
2322 	}
2323 	status = -EAGAIN;
2324 out:
2325 	xprt_unlock_connect(xprt, transport);
2326 	xprt_clear_connecting(xprt);
2327 	xprt_wake_pending_tasks(xprt, status);
2328 }
2329 
2330 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2331 {
2332 	unsigned long start, now = jiffies;
2333 
2334 	start = xprt->stat.connect_start + xprt->reestablish_timeout;
2335 	if (time_after(start, now))
2336 		return start - now;
2337 	return 0;
2338 }
2339 
2340 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2341 {
2342 	xprt->reestablish_timeout <<= 1;
2343 	if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2344 		xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2345 	if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2346 		xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2347 }
2348 
2349 /**
2350  * xs_connect - connect a socket to a remote endpoint
2351  * @xprt: pointer to transport structure
2352  * @task: address of RPC task that manages state of connect request
2353  *
2354  * TCP: If the remote end dropped the connection, delay reconnecting.
2355  *
2356  * UDP socket connects are synchronous, but we use a work queue anyway
2357  * to guarantee that even unprivileged user processes can set up a
2358  * socket on a privileged port.
2359  *
2360  * If a UDP socket connect fails, the delay behavior here prevents
2361  * retry floods (hard mounts).
2362  */
2363 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2364 {
2365 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2366 	unsigned long delay = 0;
2367 
2368 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2369 
2370 	if (transport->sock != NULL) {
2371 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2372 				"seconds\n",
2373 				xprt, xprt->reestablish_timeout / HZ);
2374 
2375 		/* Start by resetting any existing state */
2376 		xs_reset_transport(transport);
2377 
2378 		delay = xs_reconnect_delay(xprt);
2379 		xs_reconnect_backoff(xprt);
2380 
2381 	} else
2382 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2383 
2384 	queue_delayed_work(xprtiod_workqueue,
2385 			&transport->connect_worker,
2386 			delay);
2387 }
2388 
2389 /**
2390  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2391  * @xprt: rpc_xprt struct containing statistics
2392  * @seq: output file
2393  *
2394  */
2395 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2396 {
2397 	long idle_time = 0;
2398 
2399 	if (xprt_connected(xprt))
2400 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2401 
2402 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2403 			"%llu %llu %lu %llu %llu\n",
2404 			xprt->stat.bind_count,
2405 			xprt->stat.connect_count,
2406 			xprt->stat.connect_time,
2407 			idle_time,
2408 			xprt->stat.sends,
2409 			xprt->stat.recvs,
2410 			xprt->stat.bad_xids,
2411 			xprt->stat.req_u,
2412 			xprt->stat.bklog_u,
2413 			xprt->stat.max_slots,
2414 			xprt->stat.sending_u,
2415 			xprt->stat.pending_u);
2416 }
2417 
2418 /**
2419  * xs_udp_print_stats - display UDP socket-specifc stats
2420  * @xprt: rpc_xprt struct containing statistics
2421  * @seq: output file
2422  *
2423  */
2424 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2425 {
2426 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2427 
2428 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2429 			"%lu %llu %llu\n",
2430 			transport->srcport,
2431 			xprt->stat.bind_count,
2432 			xprt->stat.sends,
2433 			xprt->stat.recvs,
2434 			xprt->stat.bad_xids,
2435 			xprt->stat.req_u,
2436 			xprt->stat.bklog_u,
2437 			xprt->stat.max_slots,
2438 			xprt->stat.sending_u,
2439 			xprt->stat.pending_u);
2440 }
2441 
2442 /**
2443  * xs_tcp_print_stats - display TCP socket-specifc stats
2444  * @xprt: rpc_xprt struct containing statistics
2445  * @seq: output file
2446  *
2447  */
2448 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2449 {
2450 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2451 	long idle_time = 0;
2452 
2453 	if (xprt_connected(xprt))
2454 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2455 
2456 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2457 			"%llu %llu %lu %llu %llu\n",
2458 			transport->srcport,
2459 			xprt->stat.bind_count,
2460 			xprt->stat.connect_count,
2461 			xprt->stat.connect_time,
2462 			idle_time,
2463 			xprt->stat.sends,
2464 			xprt->stat.recvs,
2465 			xprt->stat.bad_xids,
2466 			xprt->stat.req_u,
2467 			xprt->stat.bklog_u,
2468 			xprt->stat.max_slots,
2469 			xprt->stat.sending_u,
2470 			xprt->stat.pending_u);
2471 }
2472 
2473 /*
2474  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2475  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2476  * to use the server side send routines.
2477  */
2478 static int bc_malloc(struct rpc_task *task)
2479 {
2480 	struct rpc_rqst *rqst = task->tk_rqstp;
2481 	size_t size = rqst->rq_callsize;
2482 	struct page *page;
2483 	struct rpc_buffer *buf;
2484 
2485 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2486 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2487 			  size);
2488 		return -EINVAL;
2489 	}
2490 
2491 	page = alloc_page(GFP_KERNEL);
2492 	if (!page)
2493 		return -ENOMEM;
2494 
2495 	buf = page_address(page);
2496 	buf->len = PAGE_SIZE;
2497 
2498 	rqst->rq_buffer = buf->data;
2499 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2500 	return 0;
2501 }
2502 
2503 /*
2504  * Free the space allocated in the bc_alloc routine
2505  */
2506 static void bc_free(struct rpc_task *task)
2507 {
2508 	void *buffer = task->tk_rqstp->rq_buffer;
2509 	struct rpc_buffer *buf;
2510 
2511 	buf = container_of(buffer, struct rpc_buffer, data);
2512 	free_page((unsigned long)buf);
2513 }
2514 
2515 /*
2516  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2517  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2518  */
2519 static int bc_sendto(struct rpc_rqst *req)
2520 {
2521 	int len;
2522 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2523 	struct rpc_xprt *xprt = req->rq_xprt;
2524 	struct sock_xprt *transport =
2525 				container_of(xprt, struct sock_xprt, xprt);
2526 	struct socket *sock = transport->sock;
2527 	unsigned long headoff;
2528 	unsigned long tailoff;
2529 
2530 	xs_encode_stream_record_marker(xbufp);
2531 
2532 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2533 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2534 	len = svc_send_common(sock, xbufp,
2535 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2536 			      xbufp->tail[0].iov_base, tailoff);
2537 
2538 	if (len != xbufp->len) {
2539 		printk(KERN_NOTICE "Error sending entire callback!\n");
2540 		len = -EAGAIN;
2541 	}
2542 
2543 	return len;
2544 }
2545 
2546 /*
2547  * The send routine. Borrows from svc_send
2548  */
2549 static int bc_send_request(struct rpc_rqst *req)
2550 {
2551 	struct svc_xprt	*xprt;
2552 	int len;
2553 
2554 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2555 	/*
2556 	 * Get the server socket associated with this callback xprt
2557 	 */
2558 	xprt = req->rq_xprt->bc_xprt;
2559 
2560 	/*
2561 	 * Grab the mutex to serialize data as the connection is shared
2562 	 * with the fore channel
2563 	 */
2564 	mutex_lock(&xprt->xpt_mutex);
2565 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2566 		len = -ENOTCONN;
2567 	else
2568 		len = bc_sendto(req);
2569 	mutex_unlock(&xprt->xpt_mutex);
2570 
2571 	if (len > 0)
2572 		len = 0;
2573 
2574 	return len;
2575 }
2576 
2577 /*
2578  * The close routine. Since this is client initiated, we do nothing
2579  */
2580 
2581 static void bc_close(struct rpc_xprt *xprt)
2582 {
2583 }
2584 
2585 /*
2586  * The xprt destroy routine. Again, because this connection is client
2587  * initiated, we do nothing
2588  */
2589 
2590 static void bc_destroy(struct rpc_xprt *xprt)
2591 {
2592 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2593 
2594 	xs_xprt_free(xprt);
2595 	module_put(THIS_MODULE);
2596 }
2597 
2598 static const struct rpc_xprt_ops xs_local_ops = {
2599 	.reserve_xprt		= xprt_reserve_xprt,
2600 	.release_xprt		= xprt_release_xprt,
2601 	.alloc_slot		= xprt_alloc_slot,
2602 	.free_slot		= xprt_free_slot,
2603 	.rpcbind		= xs_local_rpcbind,
2604 	.set_port		= xs_local_set_port,
2605 	.connect		= xs_local_connect,
2606 	.buf_alloc		= rpc_malloc,
2607 	.buf_free		= rpc_free,
2608 	.prepare_request	= xs_stream_prepare_request,
2609 	.send_request		= xs_local_send_request,
2610 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2611 	.close			= xs_close,
2612 	.destroy		= xs_destroy,
2613 	.print_stats		= xs_local_print_stats,
2614 	.enable_swap		= xs_enable_swap,
2615 	.disable_swap		= xs_disable_swap,
2616 };
2617 
2618 static const struct rpc_xprt_ops xs_udp_ops = {
2619 	.set_buffer_size	= xs_udp_set_buffer_size,
2620 	.reserve_xprt		= xprt_reserve_xprt_cong,
2621 	.release_xprt		= xprt_release_xprt_cong,
2622 	.alloc_slot		= xprt_alloc_slot,
2623 	.free_slot		= xprt_free_slot,
2624 	.rpcbind		= rpcb_getport_async,
2625 	.set_port		= xs_set_port,
2626 	.connect		= xs_connect,
2627 	.buf_alloc		= rpc_malloc,
2628 	.buf_free		= rpc_free,
2629 	.send_request		= xs_udp_send_request,
2630 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2631 	.timer			= xs_udp_timer,
2632 	.release_request	= xprt_release_rqst_cong,
2633 	.close			= xs_close,
2634 	.destroy		= xs_destroy,
2635 	.print_stats		= xs_udp_print_stats,
2636 	.enable_swap		= xs_enable_swap,
2637 	.disable_swap		= xs_disable_swap,
2638 	.inject_disconnect	= xs_inject_disconnect,
2639 };
2640 
2641 static const struct rpc_xprt_ops xs_tcp_ops = {
2642 	.reserve_xprt		= xprt_reserve_xprt,
2643 	.release_xprt		= xprt_release_xprt,
2644 	.alloc_slot		= xprt_alloc_slot,
2645 	.free_slot		= xprt_free_slot,
2646 	.rpcbind		= rpcb_getport_async,
2647 	.set_port		= xs_set_port,
2648 	.connect		= xs_connect,
2649 	.buf_alloc		= rpc_malloc,
2650 	.buf_free		= rpc_free,
2651 	.prepare_request	= xs_stream_prepare_request,
2652 	.send_request		= xs_tcp_send_request,
2653 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2654 	.close			= xs_tcp_shutdown,
2655 	.destroy		= xs_destroy,
2656 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2657 	.print_stats		= xs_tcp_print_stats,
2658 	.enable_swap		= xs_enable_swap,
2659 	.disable_swap		= xs_disable_swap,
2660 	.inject_disconnect	= xs_inject_disconnect,
2661 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2662 	.bc_setup		= xprt_setup_bc,
2663 	.bc_up			= xs_tcp_bc_up,
2664 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2665 	.bc_free_rqst		= xprt_free_bc_rqst,
2666 	.bc_destroy		= xprt_destroy_bc,
2667 #endif
2668 };
2669 
2670 /*
2671  * The rpc_xprt_ops for the server backchannel
2672  */
2673 
2674 static const struct rpc_xprt_ops bc_tcp_ops = {
2675 	.reserve_xprt		= xprt_reserve_xprt,
2676 	.release_xprt		= xprt_release_xprt,
2677 	.alloc_slot		= xprt_alloc_slot,
2678 	.free_slot		= xprt_free_slot,
2679 	.buf_alloc		= bc_malloc,
2680 	.buf_free		= bc_free,
2681 	.send_request		= bc_send_request,
2682 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2683 	.close			= bc_close,
2684 	.destroy		= bc_destroy,
2685 	.print_stats		= xs_tcp_print_stats,
2686 	.enable_swap		= xs_enable_swap,
2687 	.disable_swap		= xs_disable_swap,
2688 	.inject_disconnect	= xs_inject_disconnect,
2689 };
2690 
2691 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2692 {
2693 	static const struct sockaddr_in sin = {
2694 		.sin_family		= AF_INET,
2695 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2696 	};
2697 	static const struct sockaddr_in6 sin6 = {
2698 		.sin6_family		= AF_INET6,
2699 		.sin6_addr		= IN6ADDR_ANY_INIT,
2700 	};
2701 
2702 	switch (family) {
2703 	case AF_LOCAL:
2704 		break;
2705 	case AF_INET:
2706 		memcpy(sap, &sin, sizeof(sin));
2707 		break;
2708 	case AF_INET6:
2709 		memcpy(sap, &sin6, sizeof(sin6));
2710 		break;
2711 	default:
2712 		dprintk("RPC:       %s: Bad address family\n", __func__);
2713 		return -EAFNOSUPPORT;
2714 	}
2715 	return 0;
2716 }
2717 
2718 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2719 				      unsigned int slot_table_size,
2720 				      unsigned int max_slot_table_size)
2721 {
2722 	struct rpc_xprt *xprt;
2723 	struct sock_xprt *new;
2724 
2725 	if (args->addrlen > sizeof(xprt->addr)) {
2726 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2727 		return ERR_PTR(-EBADF);
2728 	}
2729 
2730 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2731 			max_slot_table_size);
2732 	if (xprt == NULL) {
2733 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2734 				"rpc_xprt\n");
2735 		return ERR_PTR(-ENOMEM);
2736 	}
2737 
2738 	new = container_of(xprt, struct sock_xprt, xprt);
2739 	mutex_init(&new->recv_mutex);
2740 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2741 	xprt->addrlen = args->addrlen;
2742 	if (args->srcaddr)
2743 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2744 	else {
2745 		int err;
2746 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2747 					(struct sockaddr *)&new->srcaddr);
2748 		if (err != 0) {
2749 			xprt_free(xprt);
2750 			return ERR_PTR(err);
2751 		}
2752 	}
2753 
2754 	return xprt;
2755 }
2756 
2757 static const struct rpc_timeout xs_local_default_timeout = {
2758 	.to_initval = 10 * HZ,
2759 	.to_maxval = 10 * HZ,
2760 	.to_retries = 2,
2761 };
2762 
2763 /**
2764  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2765  * @args: rpc transport creation arguments
2766  *
2767  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2768  */
2769 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2770 {
2771 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2772 	struct sock_xprt *transport;
2773 	struct rpc_xprt *xprt;
2774 	struct rpc_xprt *ret;
2775 
2776 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2777 			xprt_max_tcp_slot_table_entries);
2778 	if (IS_ERR(xprt))
2779 		return xprt;
2780 	transport = container_of(xprt, struct sock_xprt, xprt);
2781 
2782 	xprt->prot = 0;
2783 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2784 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2785 
2786 	xprt->bind_timeout = XS_BIND_TO;
2787 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2788 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2789 
2790 	xprt->ops = &xs_local_ops;
2791 	xprt->timeout = &xs_local_default_timeout;
2792 
2793 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2794 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2795 
2796 	switch (sun->sun_family) {
2797 	case AF_LOCAL:
2798 		if (sun->sun_path[0] != '/') {
2799 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2800 					sun->sun_path);
2801 			ret = ERR_PTR(-EINVAL);
2802 			goto out_err;
2803 		}
2804 		xprt_set_bound(xprt);
2805 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2806 		ret = ERR_PTR(xs_local_setup_socket(transport));
2807 		if (ret)
2808 			goto out_err;
2809 		break;
2810 	default:
2811 		ret = ERR_PTR(-EAFNOSUPPORT);
2812 		goto out_err;
2813 	}
2814 
2815 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2816 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2817 
2818 	if (try_module_get(THIS_MODULE))
2819 		return xprt;
2820 	ret = ERR_PTR(-EINVAL);
2821 out_err:
2822 	xs_xprt_free(xprt);
2823 	return ret;
2824 }
2825 
2826 static const struct rpc_timeout xs_udp_default_timeout = {
2827 	.to_initval = 5 * HZ,
2828 	.to_maxval = 30 * HZ,
2829 	.to_increment = 5 * HZ,
2830 	.to_retries = 5,
2831 };
2832 
2833 /**
2834  * xs_setup_udp - Set up transport to use a UDP socket
2835  * @args: rpc transport creation arguments
2836  *
2837  */
2838 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2839 {
2840 	struct sockaddr *addr = args->dstaddr;
2841 	struct rpc_xprt *xprt;
2842 	struct sock_xprt *transport;
2843 	struct rpc_xprt *ret;
2844 
2845 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2846 			xprt_udp_slot_table_entries);
2847 	if (IS_ERR(xprt))
2848 		return xprt;
2849 	transport = container_of(xprt, struct sock_xprt, xprt);
2850 
2851 	xprt->prot = IPPROTO_UDP;
2852 	xprt->tsh_size = 0;
2853 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2854 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2855 
2856 	xprt->bind_timeout = XS_BIND_TO;
2857 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2858 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2859 
2860 	xprt->ops = &xs_udp_ops;
2861 
2862 	xprt->timeout = &xs_udp_default_timeout;
2863 
2864 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2865 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2866 
2867 	switch (addr->sa_family) {
2868 	case AF_INET:
2869 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2870 			xprt_set_bound(xprt);
2871 
2872 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2873 		break;
2874 	case AF_INET6:
2875 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2876 			xprt_set_bound(xprt);
2877 
2878 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2879 		break;
2880 	default:
2881 		ret = ERR_PTR(-EAFNOSUPPORT);
2882 		goto out_err;
2883 	}
2884 
2885 	if (xprt_bound(xprt))
2886 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2887 				xprt->address_strings[RPC_DISPLAY_ADDR],
2888 				xprt->address_strings[RPC_DISPLAY_PORT],
2889 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2890 	else
2891 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2892 				xprt->address_strings[RPC_DISPLAY_ADDR],
2893 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2894 
2895 	if (try_module_get(THIS_MODULE))
2896 		return xprt;
2897 	ret = ERR_PTR(-EINVAL);
2898 out_err:
2899 	xs_xprt_free(xprt);
2900 	return ret;
2901 }
2902 
2903 static const struct rpc_timeout xs_tcp_default_timeout = {
2904 	.to_initval = 60 * HZ,
2905 	.to_maxval = 60 * HZ,
2906 	.to_retries = 2,
2907 };
2908 
2909 /**
2910  * xs_setup_tcp - Set up transport to use a TCP socket
2911  * @args: rpc transport creation arguments
2912  *
2913  */
2914 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2915 {
2916 	struct sockaddr *addr = args->dstaddr;
2917 	struct rpc_xprt *xprt;
2918 	struct sock_xprt *transport;
2919 	struct rpc_xprt *ret;
2920 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2921 
2922 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2923 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2924 
2925 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2926 			max_slot_table_size);
2927 	if (IS_ERR(xprt))
2928 		return xprt;
2929 	transport = container_of(xprt, struct sock_xprt, xprt);
2930 
2931 	xprt->prot = IPPROTO_TCP;
2932 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2933 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2934 
2935 	xprt->bind_timeout = XS_BIND_TO;
2936 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2937 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2938 
2939 	xprt->ops = &xs_tcp_ops;
2940 	xprt->timeout = &xs_tcp_default_timeout;
2941 
2942 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2943 	xprt->connect_timeout = xprt->timeout->to_initval *
2944 		(xprt->timeout->to_retries + 1);
2945 
2946 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2947 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2948 
2949 	switch (addr->sa_family) {
2950 	case AF_INET:
2951 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2952 			xprt_set_bound(xprt);
2953 
2954 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2955 		break;
2956 	case AF_INET6:
2957 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2958 			xprt_set_bound(xprt);
2959 
2960 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2961 		break;
2962 	default:
2963 		ret = ERR_PTR(-EAFNOSUPPORT);
2964 		goto out_err;
2965 	}
2966 
2967 	if (xprt_bound(xprt))
2968 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2969 				xprt->address_strings[RPC_DISPLAY_ADDR],
2970 				xprt->address_strings[RPC_DISPLAY_PORT],
2971 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2972 	else
2973 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2974 				xprt->address_strings[RPC_DISPLAY_ADDR],
2975 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2976 
2977 	if (try_module_get(THIS_MODULE))
2978 		return xprt;
2979 	ret = ERR_PTR(-EINVAL);
2980 out_err:
2981 	xs_xprt_free(xprt);
2982 	return ret;
2983 }
2984 
2985 /**
2986  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2987  * @args: rpc transport creation arguments
2988  *
2989  */
2990 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2991 {
2992 	struct sockaddr *addr = args->dstaddr;
2993 	struct rpc_xprt *xprt;
2994 	struct sock_xprt *transport;
2995 	struct svc_sock *bc_sock;
2996 	struct rpc_xprt *ret;
2997 
2998 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2999 			xprt_tcp_slot_table_entries);
3000 	if (IS_ERR(xprt))
3001 		return xprt;
3002 	transport = container_of(xprt, struct sock_xprt, xprt);
3003 
3004 	xprt->prot = IPPROTO_TCP;
3005 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3006 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3007 	xprt->timeout = &xs_tcp_default_timeout;
3008 
3009 	/* backchannel */
3010 	xprt_set_bound(xprt);
3011 	xprt->bind_timeout = 0;
3012 	xprt->reestablish_timeout = 0;
3013 	xprt->idle_timeout = 0;
3014 
3015 	xprt->ops = &bc_tcp_ops;
3016 
3017 	switch (addr->sa_family) {
3018 	case AF_INET:
3019 		xs_format_peer_addresses(xprt, "tcp",
3020 					 RPCBIND_NETID_TCP);
3021 		break;
3022 	case AF_INET6:
3023 		xs_format_peer_addresses(xprt, "tcp",
3024 				   RPCBIND_NETID_TCP6);
3025 		break;
3026 	default:
3027 		ret = ERR_PTR(-EAFNOSUPPORT);
3028 		goto out_err;
3029 	}
3030 
3031 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3032 			xprt->address_strings[RPC_DISPLAY_ADDR],
3033 			xprt->address_strings[RPC_DISPLAY_PORT],
3034 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3035 
3036 	/*
3037 	 * Once we've associated a backchannel xprt with a connection,
3038 	 * we want to keep it around as long as the connection lasts,
3039 	 * in case we need to start using it for a backchannel again;
3040 	 * this reference won't be dropped until bc_xprt is destroyed.
3041 	 */
3042 	xprt_get(xprt);
3043 	args->bc_xprt->xpt_bc_xprt = xprt;
3044 	xprt->bc_xprt = args->bc_xprt;
3045 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3046 	transport->sock = bc_sock->sk_sock;
3047 	transport->inet = bc_sock->sk_sk;
3048 
3049 	/*
3050 	 * Since we don't want connections for the backchannel, we set
3051 	 * the xprt status to connected
3052 	 */
3053 	xprt_set_connected(xprt);
3054 
3055 	if (try_module_get(THIS_MODULE))
3056 		return xprt;
3057 
3058 	args->bc_xprt->xpt_bc_xprt = NULL;
3059 	args->bc_xprt->xpt_bc_xps = NULL;
3060 	xprt_put(xprt);
3061 	ret = ERR_PTR(-EINVAL);
3062 out_err:
3063 	xs_xprt_free(xprt);
3064 	return ret;
3065 }
3066 
3067 static struct xprt_class	xs_local_transport = {
3068 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3069 	.name		= "named UNIX socket",
3070 	.owner		= THIS_MODULE,
3071 	.ident		= XPRT_TRANSPORT_LOCAL,
3072 	.setup		= xs_setup_local,
3073 };
3074 
3075 static struct xprt_class	xs_udp_transport = {
3076 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3077 	.name		= "udp",
3078 	.owner		= THIS_MODULE,
3079 	.ident		= XPRT_TRANSPORT_UDP,
3080 	.setup		= xs_setup_udp,
3081 };
3082 
3083 static struct xprt_class	xs_tcp_transport = {
3084 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3085 	.name		= "tcp",
3086 	.owner		= THIS_MODULE,
3087 	.ident		= XPRT_TRANSPORT_TCP,
3088 	.setup		= xs_setup_tcp,
3089 };
3090 
3091 static struct xprt_class	xs_bc_tcp_transport = {
3092 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3093 	.name		= "tcp NFSv4.1 backchannel",
3094 	.owner		= THIS_MODULE,
3095 	.ident		= XPRT_TRANSPORT_BC_TCP,
3096 	.setup		= xs_setup_bc_tcp,
3097 };
3098 
3099 /**
3100  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3101  *
3102  */
3103 int init_socket_xprt(void)
3104 {
3105 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3106 	if (!sunrpc_table_header)
3107 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3108 #endif
3109 
3110 	xprt_register_transport(&xs_local_transport);
3111 	xprt_register_transport(&xs_udp_transport);
3112 	xprt_register_transport(&xs_tcp_transport);
3113 	xprt_register_transport(&xs_bc_tcp_transport);
3114 
3115 	return 0;
3116 }
3117 
3118 /**
3119  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3120  *
3121  */
3122 void cleanup_socket_xprt(void)
3123 {
3124 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3125 	if (sunrpc_table_header) {
3126 		unregister_sysctl_table(sunrpc_table_header);
3127 		sunrpc_table_header = NULL;
3128 	}
3129 #endif
3130 
3131 	xprt_unregister_transport(&xs_local_transport);
3132 	xprt_unregister_transport(&xs_udp_transport);
3133 	xprt_unregister_transport(&xs_tcp_transport);
3134 	xprt_unregister_transport(&xs_bc_tcp_transport);
3135 }
3136 
3137 static int param_set_uint_minmax(const char *val,
3138 		const struct kernel_param *kp,
3139 		unsigned int min, unsigned int max)
3140 {
3141 	unsigned int num;
3142 	int ret;
3143 
3144 	if (!val)
3145 		return -EINVAL;
3146 	ret = kstrtouint(val, 0, &num);
3147 	if (ret)
3148 		return ret;
3149 	if (num < min || num > max)
3150 		return -EINVAL;
3151 	*((unsigned int *)kp->arg) = num;
3152 	return 0;
3153 }
3154 
3155 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3156 {
3157 	if (kp->arg == &xprt_min_resvport)
3158 		return param_set_uint_minmax(val, kp,
3159 			RPC_MIN_RESVPORT,
3160 			xprt_max_resvport);
3161 	return param_set_uint_minmax(val, kp,
3162 			xprt_min_resvport,
3163 			RPC_MAX_RESVPORT);
3164 }
3165 
3166 static const struct kernel_param_ops param_ops_portnr = {
3167 	.set = param_set_portnr,
3168 	.get = param_get_uint,
3169 };
3170 
3171 #define param_check_portnr(name, p) \
3172 	__param_check(name, p, unsigned int);
3173 
3174 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3175 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3176 
3177 static int param_set_slot_table_size(const char *val,
3178 				     const struct kernel_param *kp)
3179 {
3180 	return param_set_uint_minmax(val, kp,
3181 			RPC_MIN_SLOT_TABLE,
3182 			RPC_MAX_SLOT_TABLE);
3183 }
3184 
3185 static const struct kernel_param_ops param_ops_slot_table_size = {
3186 	.set = param_set_slot_table_size,
3187 	.get = param_get_uint,
3188 };
3189 
3190 #define param_check_slot_table_size(name, p) \
3191 	__param_check(name, p, unsigned int);
3192 
3193 static int param_set_max_slot_table_size(const char *val,
3194 				     const struct kernel_param *kp)
3195 {
3196 	return param_set_uint_minmax(val, kp,
3197 			RPC_MIN_SLOT_TABLE,
3198 			RPC_MAX_SLOT_TABLE_LIMIT);
3199 }
3200 
3201 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3202 	.set = param_set_max_slot_table_size,
3203 	.get = param_get_uint,
3204 };
3205 
3206 #define param_check_max_slot_table_size(name, p) \
3207 	__param_check(name, p, unsigned int);
3208 
3209 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3210 		   slot_table_size, 0644);
3211 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3212 		   max_slot_table_size, 0644);
3213 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3214 		   slot_table_size, 0644);
3215