xref: /linux/net/sunrpc/xprtsock.c (revision 08b7cf134eafca3b38e818d934b00dfe6b5b0fb4)
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/highmem.h>
52 #include <linux/uio.h>
53 #include <linux/sched/mm.h>
54 
55 #include <trace/events/sunrpc.h>
56 
57 #include "socklib.h"
58 #include "sunrpc.h"
59 
60 static void xs_close(struct rpc_xprt *xprt);
61 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock);
62 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
63 		struct socket *sock);
64 
65 /*
66  * xprtsock tunables
67  */
68 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
69 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
70 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
71 
72 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
73 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
74 
75 #define XS_TCP_LINGER_TO	(15U * HZ)
76 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
77 
78 /*
79  * We can register our own files under /proc/sys/sunrpc by
80  * calling register_sysctl_table() again.  The files in that
81  * directory become the union of all files registered there.
82  *
83  * We simply need to make sure that we don't collide with
84  * someone else's file names!
85  */
86 
87 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
88 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
89 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
90 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
91 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
92 
93 static struct ctl_table_header *sunrpc_table_header;
94 
95 static struct xprt_class xs_local_transport;
96 static struct xprt_class xs_udp_transport;
97 static struct xprt_class xs_tcp_transport;
98 static struct xprt_class xs_bc_tcp_transport;
99 
100 /*
101  * FIXME: changing the UDP slot table size should also resize the UDP
102  *        socket buffers for existing UDP transports
103  */
104 static struct ctl_table xs_tunables_table[] = {
105 	{
106 		.procname	= "udp_slot_table_entries",
107 		.data		= &xprt_udp_slot_table_entries,
108 		.maxlen		= sizeof(unsigned int),
109 		.mode		= 0644,
110 		.proc_handler	= proc_dointvec_minmax,
111 		.extra1		= &min_slot_table_size,
112 		.extra2		= &max_slot_table_size
113 	},
114 	{
115 		.procname	= "tcp_slot_table_entries",
116 		.data		= &xprt_tcp_slot_table_entries,
117 		.maxlen		= sizeof(unsigned int),
118 		.mode		= 0644,
119 		.proc_handler	= proc_dointvec_minmax,
120 		.extra1		= &min_slot_table_size,
121 		.extra2		= &max_slot_table_size
122 	},
123 	{
124 		.procname	= "tcp_max_slot_table_entries",
125 		.data		= &xprt_max_tcp_slot_table_entries,
126 		.maxlen		= sizeof(unsigned int),
127 		.mode		= 0644,
128 		.proc_handler	= proc_dointvec_minmax,
129 		.extra1		= &min_slot_table_size,
130 		.extra2		= &max_tcp_slot_table_limit
131 	},
132 	{
133 		.procname	= "min_resvport",
134 		.data		= &xprt_min_resvport,
135 		.maxlen		= sizeof(unsigned int),
136 		.mode		= 0644,
137 		.proc_handler	= proc_dointvec_minmax,
138 		.extra1		= &xprt_min_resvport_limit,
139 		.extra2		= &xprt_max_resvport_limit
140 	},
141 	{
142 		.procname	= "max_resvport",
143 		.data		= &xprt_max_resvport,
144 		.maxlen		= sizeof(unsigned int),
145 		.mode		= 0644,
146 		.proc_handler	= proc_dointvec_minmax,
147 		.extra1		= &xprt_min_resvport_limit,
148 		.extra2		= &xprt_max_resvport_limit
149 	},
150 	{
151 		.procname	= "tcp_fin_timeout",
152 		.data		= &xs_tcp_fin_timeout,
153 		.maxlen		= sizeof(xs_tcp_fin_timeout),
154 		.mode		= 0644,
155 		.proc_handler	= proc_dointvec_jiffies,
156 	},
157 	{ },
158 };
159 
160 static struct ctl_table sunrpc_table[] = {
161 	{
162 		.procname	= "sunrpc",
163 		.mode		= 0555,
164 		.child		= xs_tunables_table
165 	},
166 	{ },
167 };
168 
169 /*
170  * Wait duration for a reply from the RPC portmapper.
171  */
172 #define XS_BIND_TO		(60U * HZ)
173 
174 /*
175  * Delay if a UDP socket connect error occurs.  This is most likely some
176  * kind of resource problem on the local host.
177  */
178 #define XS_UDP_REEST_TO		(2U * HZ)
179 
180 /*
181  * The reestablish timeout allows clients to delay for a bit before attempting
182  * to reconnect to a server that just dropped our connection.
183  *
184  * We implement an exponential backoff when trying to reestablish a TCP
185  * transport connection with the server.  Some servers like to drop a TCP
186  * connection when they are overworked, so we start with a short timeout and
187  * increase over time if the server is down or not responding.
188  */
189 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
190 
191 /*
192  * TCP idle timeout; client drops the transport socket if it is idle
193  * for this long.  Note that we also timeout UDP sockets to prevent
194  * holding port numbers when there is no RPC traffic.
195  */
196 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
197 
198 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
199 # undef  RPC_DEBUG_DATA
200 # define RPCDBG_FACILITY	RPCDBG_TRANS
201 #endif
202 
203 #ifdef RPC_DEBUG_DATA
204 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
205 {
206 	u8 *buf = (u8 *) packet;
207 	int j;
208 
209 	dprintk("RPC:       %s\n", msg);
210 	for (j = 0; j < count && j < 128; j += 4) {
211 		if (!(j & 31)) {
212 			if (j)
213 				dprintk("\n");
214 			dprintk("0x%04x ", j);
215 		}
216 		dprintk("%02x%02x%02x%02x ",
217 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
218 	}
219 	dprintk("\n");
220 }
221 #else
222 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
223 {
224 	/* NOP */
225 }
226 #endif
227 
228 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
229 {
230 	return (struct rpc_xprt *) sk->sk_user_data;
231 }
232 
233 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_un *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in *) &xprt->addr;
246 }
247 
248 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
249 {
250 	return (struct sockaddr_in6 *) &xprt->addr;
251 }
252 
253 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
254 {
255 	struct sockaddr *sap = xs_addr(xprt);
256 	struct sockaddr_in6 *sin6;
257 	struct sockaddr_in *sin;
258 	struct sockaddr_un *sun;
259 	char buf[128];
260 
261 	switch (sap->sa_family) {
262 	case AF_LOCAL:
263 		sun = xs_addr_un(xprt);
264 		strlcpy(buf, sun->sun_path, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		break;
268 	case AF_INET:
269 		(void)rpc_ntop(sap, buf, sizeof(buf));
270 		xprt->address_strings[RPC_DISPLAY_ADDR] =
271 						kstrdup(buf, GFP_KERNEL);
272 		sin = xs_addr_in(xprt);
273 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
274 		break;
275 	case AF_INET6:
276 		(void)rpc_ntop(sap, buf, sizeof(buf));
277 		xprt->address_strings[RPC_DISPLAY_ADDR] =
278 						kstrdup(buf, GFP_KERNEL);
279 		sin6 = xs_addr_in6(xprt);
280 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
281 		break;
282 	default:
283 		BUG();
284 	}
285 
286 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
287 }
288 
289 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
290 {
291 	struct sockaddr *sap = xs_addr(xprt);
292 	char buf[128];
293 
294 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
295 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
296 
297 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
298 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
299 }
300 
301 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
302 				     const char *protocol,
303 				     const char *netid)
304 {
305 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
306 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
307 	xs_format_common_peer_addresses(xprt);
308 	xs_format_common_peer_ports(xprt);
309 }
310 
311 static void xs_update_peer_port(struct rpc_xprt *xprt)
312 {
313 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
314 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
315 
316 	xs_format_common_peer_ports(xprt);
317 }
318 
319 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
320 {
321 	unsigned int i;
322 
323 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
324 		switch (i) {
325 		case RPC_DISPLAY_PROTO:
326 		case RPC_DISPLAY_NETID:
327 			continue;
328 		default:
329 			kfree(xprt->address_strings[i]);
330 		}
331 }
332 
333 static size_t
334 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
335 {
336 	size_t i,n;
337 
338 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
339 		return want;
340 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
341 	for (i = 0; i < n; i++) {
342 		if (buf->pages[i])
343 			continue;
344 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
345 		if (!buf->pages[i]) {
346 			i *= PAGE_SIZE;
347 			return i > buf->page_base ? i - buf->page_base : 0;
348 		}
349 	}
350 	return want;
351 }
352 
353 static ssize_t
354 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
355 {
356 	ssize_t ret;
357 	if (seek != 0)
358 		iov_iter_advance(&msg->msg_iter, seek);
359 	ret = sock_recvmsg(sock, msg, flags);
360 	return ret > 0 ? ret + seek : ret;
361 }
362 
363 static ssize_t
364 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
365 		struct kvec *kvec, size_t count, size_t seek)
366 {
367 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
368 	return xs_sock_recvmsg(sock, msg, flags, seek);
369 }
370 
371 static ssize_t
372 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
373 		struct bio_vec *bvec, unsigned long nr, size_t count,
374 		size_t seek)
375 {
376 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
377 	return xs_sock_recvmsg(sock, msg, flags, seek);
378 }
379 
380 static ssize_t
381 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
382 		size_t count)
383 {
384 	iov_iter_discard(&msg->msg_iter, READ, count);
385 	return sock_recvmsg(sock, msg, flags);
386 }
387 
388 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
389 static void
390 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
391 {
392 	struct bvec_iter bi = {
393 		.bi_size = count,
394 	};
395 	struct bio_vec bv;
396 
397 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
398 	for_each_bvec(bv, bvec, bi, bi)
399 		flush_dcache_page(bv.bv_page);
400 }
401 #else
402 static inline void
403 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
404 {
405 }
406 #endif
407 
408 static ssize_t
409 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
410 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
411 {
412 	size_t want, seek_init = seek, offset = 0;
413 	ssize_t ret;
414 
415 	want = min_t(size_t, count, buf->head[0].iov_len);
416 	if (seek < want) {
417 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
418 		if (ret <= 0)
419 			goto sock_err;
420 		offset += ret;
421 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
422 			goto out;
423 		if (ret != want)
424 			goto out;
425 		seek = 0;
426 	} else {
427 		seek -= want;
428 		offset += want;
429 	}
430 
431 	want = xs_alloc_sparse_pages(
432 		buf, min_t(size_t, count - offset, buf->page_len),
433 		GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
434 	if (seek < want) {
435 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
436 				xdr_buf_pagecount(buf),
437 				want + buf->page_base,
438 				seek + buf->page_base);
439 		if (ret <= 0)
440 			goto sock_err;
441 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
442 		ret -= buf->page_base;
443 		offset += ret;
444 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
445 			goto out;
446 		if (ret != want)
447 			goto out;
448 		seek = 0;
449 	} else {
450 		seek -= want;
451 		offset += want;
452 	}
453 
454 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
455 	if (seek < want) {
456 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
457 		if (ret <= 0)
458 			goto sock_err;
459 		offset += ret;
460 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
461 			goto out;
462 		if (ret != want)
463 			goto out;
464 	} else if (offset < seek_init)
465 		offset = seek_init;
466 	ret = -EMSGSIZE;
467 out:
468 	*read = offset - seek_init;
469 	return ret;
470 sock_err:
471 	offset += seek;
472 	goto out;
473 }
474 
475 static void
476 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
477 {
478 	if (!transport->recv.copied) {
479 		if (buf->head[0].iov_len >= transport->recv.offset)
480 			memcpy(buf->head[0].iov_base,
481 					&transport->recv.xid,
482 					transport->recv.offset);
483 		transport->recv.copied = transport->recv.offset;
484 	}
485 }
486 
487 static bool
488 xs_read_stream_request_done(struct sock_xprt *transport)
489 {
490 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
491 }
492 
493 static void
494 xs_read_stream_check_eor(struct sock_xprt *transport,
495 		struct msghdr *msg)
496 {
497 	if (xs_read_stream_request_done(transport))
498 		msg->msg_flags |= MSG_EOR;
499 }
500 
501 static ssize_t
502 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
503 		int flags, struct rpc_rqst *req)
504 {
505 	struct xdr_buf *buf = &req->rq_private_buf;
506 	size_t want, read;
507 	ssize_t ret;
508 
509 	xs_read_header(transport, buf);
510 
511 	want = transport->recv.len - transport->recv.offset;
512 	if (want != 0) {
513 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
514 				transport->recv.copied + want,
515 				transport->recv.copied,
516 				&read);
517 		transport->recv.offset += read;
518 		transport->recv.copied += read;
519 	}
520 
521 	if (transport->recv.offset == transport->recv.len)
522 		xs_read_stream_check_eor(transport, msg);
523 
524 	if (want == 0)
525 		return 0;
526 
527 	switch (ret) {
528 	default:
529 		break;
530 	case -EFAULT:
531 	case -EMSGSIZE:
532 		msg->msg_flags |= MSG_TRUNC;
533 		return read;
534 	case 0:
535 		return -ESHUTDOWN;
536 	}
537 	return ret < 0 ? ret : read;
538 }
539 
540 static size_t
541 xs_read_stream_headersize(bool isfrag)
542 {
543 	if (isfrag)
544 		return sizeof(__be32);
545 	return 3 * sizeof(__be32);
546 }
547 
548 static ssize_t
549 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
550 		int flags, size_t want, size_t seek)
551 {
552 	struct kvec kvec = {
553 		.iov_base = &transport->recv.fraghdr,
554 		.iov_len = want,
555 	};
556 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
557 }
558 
559 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
560 static ssize_t
561 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
562 {
563 	struct rpc_xprt *xprt = &transport->xprt;
564 	struct rpc_rqst *req;
565 	ssize_t ret;
566 
567 	/* Is this transport associated with the backchannel? */
568 	if (!xprt->bc_serv)
569 		return -ESHUTDOWN;
570 
571 	/* Look up and lock the request corresponding to the given XID */
572 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
573 	if (!req) {
574 		printk(KERN_WARNING "Callback slot table overflowed\n");
575 		return -ESHUTDOWN;
576 	}
577 	if (transport->recv.copied && !req->rq_private_buf.len)
578 		return -ESHUTDOWN;
579 
580 	ret = xs_read_stream_request(transport, msg, flags, req);
581 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
582 		xprt_complete_bc_request(req, transport->recv.copied);
583 	else
584 		req->rq_private_buf.len = transport->recv.copied;
585 
586 	return ret;
587 }
588 #else /* CONFIG_SUNRPC_BACKCHANNEL */
589 static ssize_t
590 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
591 {
592 	return -ESHUTDOWN;
593 }
594 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
595 
596 static ssize_t
597 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
598 {
599 	struct rpc_xprt *xprt = &transport->xprt;
600 	struct rpc_rqst *req;
601 	ssize_t ret = 0;
602 
603 	/* Look up and lock the request corresponding to the given XID */
604 	spin_lock(&xprt->queue_lock);
605 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
606 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
607 		msg->msg_flags |= MSG_TRUNC;
608 		goto out;
609 	}
610 	xprt_pin_rqst(req);
611 	spin_unlock(&xprt->queue_lock);
612 
613 	ret = xs_read_stream_request(transport, msg, flags, req);
614 
615 	spin_lock(&xprt->queue_lock);
616 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
617 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
618 	else
619 		req->rq_private_buf.len = transport->recv.copied;
620 	xprt_unpin_rqst(req);
621 out:
622 	spin_unlock(&xprt->queue_lock);
623 	return ret;
624 }
625 
626 static ssize_t
627 xs_read_stream(struct sock_xprt *transport, int flags)
628 {
629 	struct msghdr msg = { 0 };
630 	size_t want, read = 0;
631 	ssize_t ret = 0;
632 
633 	if (transport->recv.len == 0) {
634 		want = xs_read_stream_headersize(transport->recv.copied != 0);
635 		ret = xs_read_stream_header(transport, &msg, flags, want,
636 				transport->recv.offset);
637 		if (ret <= 0)
638 			goto out_err;
639 		transport->recv.offset = ret;
640 		if (transport->recv.offset != want)
641 			return transport->recv.offset;
642 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
643 			RPC_FRAGMENT_SIZE_MASK;
644 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
645 		read = ret;
646 	}
647 
648 	switch (be32_to_cpu(transport->recv.calldir)) {
649 	default:
650 		msg.msg_flags |= MSG_TRUNC;
651 		break;
652 	case RPC_CALL:
653 		ret = xs_read_stream_call(transport, &msg, flags);
654 		break;
655 	case RPC_REPLY:
656 		ret = xs_read_stream_reply(transport, &msg, flags);
657 	}
658 	if (msg.msg_flags & MSG_TRUNC) {
659 		transport->recv.calldir = cpu_to_be32(-1);
660 		transport->recv.copied = -1;
661 	}
662 	if (ret < 0)
663 		goto out_err;
664 	read += ret;
665 	if (transport->recv.offset < transport->recv.len) {
666 		if (!(msg.msg_flags & MSG_TRUNC))
667 			return read;
668 		msg.msg_flags = 0;
669 		ret = xs_read_discard(transport->sock, &msg, flags,
670 				transport->recv.len - transport->recv.offset);
671 		if (ret <= 0)
672 			goto out_err;
673 		transport->recv.offset += ret;
674 		read += ret;
675 		if (transport->recv.offset != transport->recv.len)
676 			return read;
677 	}
678 	if (xs_read_stream_request_done(transport)) {
679 		trace_xs_stream_read_request(transport);
680 		transport->recv.copied = 0;
681 	}
682 	transport->recv.offset = 0;
683 	transport->recv.len = 0;
684 	return read;
685 out_err:
686 	return ret != 0 ? ret : -ESHUTDOWN;
687 }
688 
689 static __poll_t xs_poll_socket(struct sock_xprt *transport)
690 {
691 	return transport->sock->ops->poll(transport->file, transport->sock,
692 			NULL);
693 }
694 
695 static bool xs_poll_socket_readable(struct sock_xprt *transport)
696 {
697 	__poll_t events = xs_poll_socket(transport);
698 
699 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
700 }
701 
702 static void xs_poll_check_readable(struct sock_xprt *transport)
703 {
704 
705 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
706 	if (!xs_poll_socket_readable(transport))
707 		return;
708 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
709 		queue_work(xprtiod_workqueue, &transport->recv_worker);
710 }
711 
712 static void xs_stream_data_receive(struct sock_xprt *transport)
713 {
714 	size_t read = 0;
715 	ssize_t ret = 0;
716 
717 	mutex_lock(&transport->recv_mutex);
718 	if (transport->sock == NULL)
719 		goto out;
720 	for (;;) {
721 		ret = xs_read_stream(transport, MSG_DONTWAIT);
722 		if (ret < 0)
723 			break;
724 		read += ret;
725 		cond_resched();
726 	}
727 	if (ret == -ESHUTDOWN)
728 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
729 	else
730 		xs_poll_check_readable(transport);
731 out:
732 	mutex_unlock(&transport->recv_mutex);
733 	trace_xs_stream_read_data(&transport->xprt, ret, read);
734 }
735 
736 static void xs_stream_data_receive_workfn(struct work_struct *work)
737 {
738 	struct sock_xprt *transport =
739 		container_of(work, struct sock_xprt, recv_worker);
740 	unsigned int pflags = memalloc_nofs_save();
741 
742 	xs_stream_data_receive(transport);
743 	memalloc_nofs_restore(pflags);
744 }
745 
746 static void
747 xs_stream_reset_connect(struct sock_xprt *transport)
748 {
749 	transport->recv.offset = 0;
750 	transport->recv.len = 0;
751 	transport->recv.copied = 0;
752 	transport->xmit.offset = 0;
753 }
754 
755 static void
756 xs_stream_start_connect(struct sock_xprt *transport)
757 {
758 	transport->xprt.stat.connect_count++;
759 	transport->xprt.stat.connect_start = jiffies;
760 }
761 
762 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
763 
764 /**
765  * xs_nospace - handle transmit was incomplete
766  * @req: pointer to RPC request
767  * @transport: pointer to struct sock_xprt
768  *
769  */
770 static int xs_nospace(struct rpc_rqst *req, struct sock_xprt *transport)
771 {
772 	struct rpc_xprt *xprt = &transport->xprt;
773 	struct sock *sk = transport->inet;
774 	int ret = -EAGAIN;
775 
776 	trace_rpc_socket_nospace(req, transport);
777 
778 	/* Protect against races with write_space */
779 	spin_lock(&xprt->transport_lock);
780 
781 	/* Don't race with disconnect */
782 	if (xprt_connected(xprt)) {
783 		/* wait for more buffer space */
784 		set_bit(XPRT_SOCK_NOSPACE, &transport->sock_state);
785 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
786 		sk->sk_write_pending++;
787 		xprt_wait_for_buffer_space(xprt);
788 	} else
789 		ret = -ENOTCONN;
790 
791 	spin_unlock(&xprt->transport_lock);
792 	return ret;
793 }
794 
795 static int xs_sock_nospace(struct rpc_rqst *req)
796 {
797 	struct sock_xprt *transport =
798 		container_of(req->rq_xprt, struct sock_xprt, xprt);
799 	struct sock *sk = transport->inet;
800 	int ret = -EAGAIN;
801 
802 	lock_sock(sk);
803 	if (!sock_writeable(sk))
804 		ret = xs_nospace(req, transport);
805 	release_sock(sk);
806 	return ret;
807 }
808 
809 static int xs_stream_nospace(struct rpc_rqst *req, bool vm_wait)
810 {
811 	struct sock_xprt *transport =
812 		container_of(req->rq_xprt, struct sock_xprt, xprt);
813 	struct sock *sk = transport->inet;
814 	int ret = -EAGAIN;
815 
816 	if (vm_wait)
817 		return -ENOBUFS;
818 	lock_sock(sk);
819 	if (!sk_stream_memory_free(sk))
820 		ret = xs_nospace(req, transport);
821 	release_sock(sk);
822 	return ret;
823 }
824 
825 static void
826 xs_stream_prepare_request(struct rpc_rqst *req)
827 {
828 	xdr_free_bvec(&req->rq_rcv_buf);
829 	req->rq_task->tk_status = xdr_alloc_bvec(
830 		&req->rq_rcv_buf, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
831 }
832 
833 /*
834  * Determine if the previous message in the stream was aborted before it
835  * could complete transmission.
836  */
837 static bool
838 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
839 {
840 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
841 }
842 
843 /*
844  * Return the stream record marker field for a record of length < 2^31-1
845  */
846 static rpc_fraghdr
847 xs_stream_record_marker(struct xdr_buf *xdr)
848 {
849 	if (!xdr->len)
850 		return 0;
851 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
852 }
853 
854 /**
855  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
856  * @req: pointer to RPC request
857  *
858  * Return values:
859  *        0:	The request has been sent
860  *   EAGAIN:	The socket was blocked, please call again later to
861  *		complete the request
862  * ENOTCONN:	Caller needs to invoke connect logic then call again
863  *    other:	Some other error occurred, the request was not sent
864  */
865 static int xs_local_send_request(struct rpc_rqst *req)
866 {
867 	struct rpc_xprt *xprt = req->rq_xprt;
868 	struct sock_xprt *transport =
869 				container_of(xprt, struct sock_xprt, xprt);
870 	struct xdr_buf *xdr = &req->rq_snd_buf;
871 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
872 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
873 	struct msghdr msg = {
874 		.msg_flags	= XS_SENDMSG_FLAGS,
875 	};
876 	bool vm_wait;
877 	unsigned int sent;
878 	int status;
879 
880 	/* Close the stream if the previous transmission was incomplete */
881 	if (xs_send_request_was_aborted(transport, req)) {
882 		xs_close(xprt);
883 		return -ENOTCONN;
884 	}
885 
886 	xs_pktdump("packet data:",
887 			req->rq_svec->iov_base, req->rq_svec->iov_len);
888 
889 	vm_wait = sk_stream_is_writeable(transport->inet) ? true : false;
890 
891 	req->rq_xtime = ktime_get();
892 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
893 				   transport->xmit.offset, rm, &sent);
894 	dprintk("RPC:       %s(%u) = %d\n",
895 			__func__, xdr->len - transport->xmit.offset, status);
896 
897 	if (likely(sent > 0) || status == 0) {
898 		transport->xmit.offset += sent;
899 		req->rq_bytes_sent = transport->xmit.offset;
900 		if (likely(req->rq_bytes_sent >= msglen)) {
901 			req->rq_xmit_bytes_sent += transport->xmit.offset;
902 			transport->xmit.offset = 0;
903 			return 0;
904 		}
905 		status = -EAGAIN;
906 		vm_wait = false;
907 	}
908 
909 	switch (status) {
910 	case -EAGAIN:
911 		status = xs_stream_nospace(req, vm_wait);
912 		break;
913 	default:
914 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
915 			-status);
916 		fallthrough;
917 	case -EPIPE:
918 		xs_close(xprt);
919 		status = -ENOTCONN;
920 	}
921 
922 	return status;
923 }
924 
925 /**
926  * xs_udp_send_request - write an RPC request to a UDP socket
927  * @req: pointer to RPC request
928  *
929  * Return values:
930  *        0:	The request has been sent
931  *   EAGAIN:	The socket was blocked, please call again later to
932  *		complete the request
933  * ENOTCONN:	Caller needs to invoke connect logic then call again
934  *    other:	Some other error occurred, the request was not sent
935  */
936 static int xs_udp_send_request(struct rpc_rqst *req)
937 {
938 	struct rpc_xprt *xprt = req->rq_xprt;
939 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
940 	struct xdr_buf *xdr = &req->rq_snd_buf;
941 	struct msghdr msg = {
942 		.msg_name	= xs_addr(xprt),
943 		.msg_namelen	= xprt->addrlen,
944 		.msg_flags	= XS_SENDMSG_FLAGS,
945 	};
946 	unsigned int sent;
947 	int status;
948 
949 	xs_pktdump("packet data:",
950 				req->rq_svec->iov_base,
951 				req->rq_svec->iov_len);
952 
953 	if (!xprt_bound(xprt))
954 		return -ENOTCONN;
955 
956 	if (!xprt_request_get_cong(xprt, req))
957 		return -EBADSLT;
958 
959 	req->rq_xtime = ktime_get();
960 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
961 
962 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
963 			xdr->len, status);
964 
965 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
966 	if (status == -EPERM)
967 		goto process_status;
968 
969 	if (status == -EAGAIN && sock_writeable(transport->inet))
970 		status = -ENOBUFS;
971 
972 	if (sent > 0 || status == 0) {
973 		req->rq_xmit_bytes_sent += sent;
974 		if (sent >= req->rq_slen)
975 			return 0;
976 		/* Still some bytes left; set up for a retry later. */
977 		status = -EAGAIN;
978 	}
979 
980 process_status:
981 	switch (status) {
982 	case -ENOTSOCK:
983 		status = -ENOTCONN;
984 		/* Should we call xs_close() here? */
985 		break;
986 	case -EAGAIN:
987 		status = xs_sock_nospace(req);
988 		break;
989 	case -ENETUNREACH:
990 	case -ENOBUFS:
991 	case -EPIPE:
992 	case -ECONNREFUSED:
993 	case -EPERM:
994 		/* When the server has died, an ICMP port unreachable message
995 		 * prompts ECONNREFUSED. */
996 		break;
997 	default:
998 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
999 			-status);
1000 	}
1001 
1002 	return status;
1003 }
1004 
1005 /**
1006  * xs_tcp_send_request - write an RPC request to a TCP socket
1007  * @req: pointer to RPC request
1008  *
1009  * Return values:
1010  *        0:	The request has been sent
1011  *   EAGAIN:	The socket was blocked, please call again later to
1012  *		complete the request
1013  * ENOTCONN:	Caller needs to invoke connect logic then call again
1014  *    other:	Some other error occurred, the request was not sent
1015  *
1016  * XXX: In the case of soft timeouts, should we eventually give up
1017  *	if sendmsg is not able to make progress?
1018  */
1019 static int xs_tcp_send_request(struct rpc_rqst *req)
1020 {
1021 	struct rpc_xprt *xprt = req->rq_xprt;
1022 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1023 	struct xdr_buf *xdr = &req->rq_snd_buf;
1024 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
1025 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1026 	struct msghdr msg = {
1027 		.msg_flags	= XS_SENDMSG_FLAGS,
1028 	};
1029 	bool vm_wait;
1030 	unsigned int sent;
1031 	int status;
1032 
1033 	/* Close the stream if the previous transmission was incomplete */
1034 	if (xs_send_request_was_aborted(transport, req)) {
1035 		if (transport->sock != NULL)
1036 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1037 		return -ENOTCONN;
1038 	}
1039 	if (!transport->inet)
1040 		return -ENOTCONN;
1041 
1042 	xs_pktdump("packet data:",
1043 				req->rq_svec->iov_base,
1044 				req->rq_svec->iov_len);
1045 
1046 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1047 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1048 
1049 	xs_set_srcport(transport, transport->sock);
1050 
1051 	/* Continue transmitting the packet/record. We must be careful
1052 	 * to cope with writespace callbacks arriving _after_ we have
1053 	 * called sendmsg(). */
1054 	req->rq_xtime = ktime_get();
1055 	tcp_sock_set_cork(transport->inet, true);
1056 
1057 	vm_wait = sk_stream_is_writeable(transport->inet) ? true : false;
1058 
1059 	do {
1060 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1061 					   transport->xmit.offset, rm, &sent);
1062 
1063 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1064 				xdr->len - transport->xmit.offset, status);
1065 
1066 		/* If we've sent the entire packet, immediately
1067 		 * reset the count of bytes sent. */
1068 		transport->xmit.offset += sent;
1069 		req->rq_bytes_sent = transport->xmit.offset;
1070 		if (likely(req->rq_bytes_sent >= msglen)) {
1071 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1072 			transport->xmit.offset = 0;
1073 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1074 				tcp_sock_set_cork(transport->inet, false);
1075 			return 0;
1076 		}
1077 
1078 		WARN_ON_ONCE(sent == 0 && status == 0);
1079 
1080 		if (sent > 0)
1081 			vm_wait = false;
1082 
1083 	} while (status == 0);
1084 
1085 	switch (status) {
1086 	case -ENOTSOCK:
1087 		status = -ENOTCONN;
1088 		/* Should we call xs_close() here? */
1089 		break;
1090 	case -EAGAIN:
1091 		status = xs_stream_nospace(req, vm_wait);
1092 		break;
1093 	case -ECONNRESET:
1094 	case -ECONNREFUSED:
1095 	case -ENOTCONN:
1096 	case -EADDRINUSE:
1097 	case -ENOBUFS:
1098 	case -EPIPE:
1099 		break;
1100 	default:
1101 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1102 			-status);
1103 	}
1104 
1105 	return status;
1106 }
1107 
1108 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1109 {
1110 	transport->old_data_ready = sk->sk_data_ready;
1111 	transport->old_state_change = sk->sk_state_change;
1112 	transport->old_write_space = sk->sk_write_space;
1113 	transport->old_error_report = sk->sk_error_report;
1114 }
1115 
1116 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1117 {
1118 	sk->sk_data_ready = transport->old_data_ready;
1119 	sk->sk_state_change = transport->old_state_change;
1120 	sk->sk_write_space = transport->old_write_space;
1121 	sk->sk_error_report = transport->old_error_report;
1122 }
1123 
1124 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1125 {
1126 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1127 
1128 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1129 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1130 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1131 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1132 	clear_bit(XPRT_SOCK_NOSPACE, &transport->sock_state);
1133 }
1134 
1135 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1136 {
1137 	set_bit(nr, &transport->sock_state);
1138 	queue_work(xprtiod_workqueue, &transport->error_worker);
1139 }
1140 
1141 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1142 {
1143 	xprt->connect_cookie++;
1144 	smp_mb__before_atomic();
1145 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1146 	clear_bit(XPRT_CLOSING, &xprt->state);
1147 	xs_sock_reset_state_flags(xprt);
1148 	smp_mb__after_atomic();
1149 }
1150 
1151 /**
1152  * xs_error_report - callback to handle TCP socket state errors
1153  * @sk: socket
1154  *
1155  * Note: we don't call sock_error() since there may be a rpc_task
1156  * using the socket, and so we don't want to clear sk->sk_err.
1157  */
1158 static void xs_error_report(struct sock *sk)
1159 {
1160 	struct sock_xprt *transport;
1161 	struct rpc_xprt *xprt;
1162 
1163 	if (!(xprt = xprt_from_sock(sk)))
1164 		return;
1165 
1166 	transport = container_of(xprt, struct sock_xprt, xprt);
1167 	transport->xprt_err = -sk->sk_err;
1168 	if (transport->xprt_err == 0)
1169 		return;
1170 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1171 			xprt, -transport->xprt_err);
1172 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1173 
1174 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1175 	smp_mb__before_atomic();
1176 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1177 }
1178 
1179 static void xs_reset_transport(struct sock_xprt *transport)
1180 {
1181 	struct socket *sock = transport->sock;
1182 	struct sock *sk = transport->inet;
1183 	struct rpc_xprt *xprt = &transport->xprt;
1184 	struct file *filp = transport->file;
1185 
1186 	if (sk == NULL)
1187 		return;
1188 
1189 	if (atomic_read(&transport->xprt.swapper))
1190 		sk_clear_memalloc(sk);
1191 
1192 	kernel_sock_shutdown(sock, SHUT_RDWR);
1193 
1194 	mutex_lock(&transport->recv_mutex);
1195 	lock_sock(sk);
1196 	transport->inet = NULL;
1197 	transport->sock = NULL;
1198 	transport->file = NULL;
1199 
1200 	sk->sk_user_data = NULL;
1201 
1202 	xs_restore_old_callbacks(transport, sk);
1203 	xprt_clear_connected(xprt);
1204 	xs_sock_reset_connection_flags(xprt);
1205 	/* Reset stream record info */
1206 	xs_stream_reset_connect(transport);
1207 	release_sock(sk);
1208 	mutex_unlock(&transport->recv_mutex);
1209 
1210 	trace_rpc_socket_close(xprt, sock);
1211 	fput(filp);
1212 
1213 	xprt_disconnect_done(xprt);
1214 }
1215 
1216 /**
1217  * xs_close - close a socket
1218  * @xprt: transport
1219  *
1220  * This is used when all requests are complete; ie, no DRC state remains
1221  * on the server we want to save.
1222  *
1223  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1224  * xs_reset_transport() zeroing the socket from underneath a writer.
1225  */
1226 static void xs_close(struct rpc_xprt *xprt)
1227 {
1228 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1229 
1230 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1231 
1232 	xs_reset_transport(transport);
1233 	xprt->reestablish_timeout = 0;
1234 }
1235 
1236 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1237 {
1238 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1239 		xprt);
1240 	xprt_disconnect_done(xprt);
1241 }
1242 
1243 static void xs_xprt_free(struct rpc_xprt *xprt)
1244 {
1245 	xs_free_peer_addresses(xprt);
1246 	xprt_free(xprt);
1247 }
1248 
1249 /**
1250  * xs_destroy - prepare to shutdown a transport
1251  * @xprt: doomed transport
1252  *
1253  */
1254 static void xs_destroy(struct rpc_xprt *xprt)
1255 {
1256 	struct sock_xprt *transport = container_of(xprt,
1257 			struct sock_xprt, xprt);
1258 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1259 
1260 	cancel_delayed_work_sync(&transport->connect_worker);
1261 	xs_close(xprt);
1262 	cancel_work_sync(&transport->recv_worker);
1263 	cancel_work_sync(&transport->error_worker);
1264 	xs_xprt_free(xprt);
1265 	module_put(THIS_MODULE);
1266 }
1267 
1268 /**
1269  * xs_udp_data_read_skb - receive callback for UDP sockets
1270  * @xprt: transport
1271  * @sk: socket
1272  * @skb: skbuff
1273  *
1274  */
1275 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1276 		struct sock *sk,
1277 		struct sk_buff *skb)
1278 {
1279 	struct rpc_task *task;
1280 	struct rpc_rqst *rovr;
1281 	int repsize, copied;
1282 	u32 _xid;
1283 	__be32 *xp;
1284 
1285 	repsize = skb->len;
1286 	if (repsize < 4) {
1287 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1288 		return;
1289 	}
1290 
1291 	/* Copy the XID from the skb... */
1292 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1293 	if (xp == NULL)
1294 		return;
1295 
1296 	/* Look up and lock the request corresponding to the given XID */
1297 	spin_lock(&xprt->queue_lock);
1298 	rovr = xprt_lookup_rqst(xprt, *xp);
1299 	if (!rovr)
1300 		goto out_unlock;
1301 	xprt_pin_rqst(rovr);
1302 	xprt_update_rtt(rovr->rq_task);
1303 	spin_unlock(&xprt->queue_lock);
1304 	task = rovr->rq_task;
1305 
1306 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1307 		copied = repsize;
1308 
1309 	/* Suck it into the iovec, verify checksum if not done by hw. */
1310 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1311 		spin_lock(&xprt->queue_lock);
1312 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1313 		goto out_unpin;
1314 	}
1315 
1316 
1317 	spin_lock(&xprt->transport_lock);
1318 	xprt_adjust_cwnd(xprt, task, copied);
1319 	spin_unlock(&xprt->transport_lock);
1320 	spin_lock(&xprt->queue_lock);
1321 	xprt_complete_rqst(task, copied);
1322 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1323 out_unpin:
1324 	xprt_unpin_rqst(rovr);
1325  out_unlock:
1326 	spin_unlock(&xprt->queue_lock);
1327 }
1328 
1329 static void xs_udp_data_receive(struct sock_xprt *transport)
1330 {
1331 	struct sk_buff *skb;
1332 	struct sock *sk;
1333 	int err;
1334 
1335 	mutex_lock(&transport->recv_mutex);
1336 	sk = transport->inet;
1337 	if (sk == NULL)
1338 		goto out;
1339 	for (;;) {
1340 		skb = skb_recv_udp(sk, 0, 1, &err);
1341 		if (skb == NULL)
1342 			break;
1343 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1344 		consume_skb(skb);
1345 		cond_resched();
1346 	}
1347 	xs_poll_check_readable(transport);
1348 out:
1349 	mutex_unlock(&transport->recv_mutex);
1350 }
1351 
1352 static void xs_udp_data_receive_workfn(struct work_struct *work)
1353 {
1354 	struct sock_xprt *transport =
1355 		container_of(work, struct sock_xprt, recv_worker);
1356 	unsigned int pflags = memalloc_nofs_save();
1357 
1358 	xs_udp_data_receive(transport);
1359 	memalloc_nofs_restore(pflags);
1360 }
1361 
1362 /**
1363  * xs_data_ready - "data ready" callback for UDP sockets
1364  * @sk: socket with data to read
1365  *
1366  */
1367 static void xs_data_ready(struct sock *sk)
1368 {
1369 	struct rpc_xprt *xprt;
1370 
1371 	dprintk("RPC:       xs_data_ready...\n");
1372 	xprt = xprt_from_sock(sk);
1373 	if (xprt != NULL) {
1374 		struct sock_xprt *transport = container_of(xprt,
1375 				struct sock_xprt, xprt);
1376 		transport->old_data_ready(sk);
1377 		/* Any data means we had a useful conversation, so
1378 		 * then we don't need to delay the next reconnect
1379 		 */
1380 		if (xprt->reestablish_timeout)
1381 			xprt->reestablish_timeout = 0;
1382 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1383 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1384 	}
1385 }
1386 
1387 /*
1388  * Helper function to force a TCP close if the server is sending
1389  * junk and/or it has put us in CLOSE_WAIT
1390  */
1391 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1392 {
1393 	xprt_force_disconnect(xprt);
1394 }
1395 
1396 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1397 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1398 {
1399 	return PAGE_SIZE;
1400 }
1401 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1402 
1403 /**
1404  * xs_tcp_state_change - callback to handle TCP socket state changes
1405  * @sk: socket whose state has changed
1406  *
1407  */
1408 static void xs_tcp_state_change(struct sock *sk)
1409 {
1410 	struct rpc_xprt *xprt;
1411 	struct sock_xprt *transport;
1412 
1413 	if (!(xprt = xprt_from_sock(sk)))
1414 		return;
1415 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1416 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1417 			sk->sk_state, xprt_connected(xprt),
1418 			sock_flag(sk, SOCK_DEAD),
1419 			sock_flag(sk, SOCK_ZAPPED),
1420 			sk->sk_shutdown);
1421 
1422 	transport = container_of(xprt, struct sock_xprt, xprt);
1423 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1424 	switch (sk->sk_state) {
1425 	case TCP_ESTABLISHED:
1426 		if (!xprt_test_and_set_connected(xprt)) {
1427 			xprt->connect_cookie++;
1428 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1429 			xprt_clear_connecting(xprt);
1430 
1431 			xprt->stat.connect_count++;
1432 			xprt->stat.connect_time += (long)jiffies -
1433 						   xprt->stat.connect_start;
1434 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1435 		}
1436 		break;
1437 	case TCP_FIN_WAIT1:
1438 		/* The client initiated a shutdown of the socket */
1439 		xprt->connect_cookie++;
1440 		xprt->reestablish_timeout = 0;
1441 		set_bit(XPRT_CLOSING, &xprt->state);
1442 		smp_mb__before_atomic();
1443 		clear_bit(XPRT_CONNECTED, &xprt->state);
1444 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1445 		smp_mb__after_atomic();
1446 		break;
1447 	case TCP_CLOSE_WAIT:
1448 		/* The server initiated a shutdown of the socket */
1449 		xprt->connect_cookie++;
1450 		clear_bit(XPRT_CONNECTED, &xprt->state);
1451 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1452 		fallthrough;
1453 	case TCP_CLOSING:
1454 		/*
1455 		 * If the server closed down the connection, make sure that
1456 		 * we back off before reconnecting
1457 		 */
1458 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1459 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1460 		break;
1461 	case TCP_LAST_ACK:
1462 		set_bit(XPRT_CLOSING, &xprt->state);
1463 		smp_mb__before_atomic();
1464 		clear_bit(XPRT_CONNECTED, &xprt->state);
1465 		smp_mb__after_atomic();
1466 		break;
1467 	case TCP_CLOSE:
1468 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1469 					&transport->sock_state))
1470 			xprt_clear_connecting(xprt);
1471 		clear_bit(XPRT_CLOSING, &xprt->state);
1472 		/* Trigger the socket release */
1473 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1474 	}
1475 }
1476 
1477 static void xs_write_space(struct sock *sk)
1478 {
1479 	struct sock_xprt *transport;
1480 	struct rpc_xprt *xprt;
1481 
1482 	if (!sk->sk_socket)
1483 		return;
1484 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1485 
1486 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1487 		return;
1488 	transport = container_of(xprt, struct sock_xprt, xprt);
1489 	if (!test_and_clear_bit(XPRT_SOCK_NOSPACE, &transport->sock_state))
1490 		return;
1491 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1492 	sk->sk_write_pending--;
1493 }
1494 
1495 /**
1496  * xs_udp_write_space - callback invoked when socket buffer space
1497  *                             becomes available
1498  * @sk: socket whose state has changed
1499  *
1500  * Called when more output buffer space is available for this socket.
1501  * We try not to wake our writers until they can make "significant"
1502  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1503  * with a bunch of small requests.
1504  */
1505 static void xs_udp_write_space(struct sock *sk)
1506 {
1507 	/* from net/core/sock.c:sock_def_write_space */
1508 	if (sock_writeable(sk))
1509 		xs_write_space(sk);
1510 }
1511 
1512 /**
1513  * xs_tcp_write_space - callback invoked when socket buffer space
1514  *                             becomes available
1515  * @sk: socket whose state has changed
1516  *
1517  * Called when more output buffer space is available for this socket.
1518  * We try not to wake our writers until they can make "significant"
1519  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1520  * with a bunch of small requests.
1521  */
1522 static void xs_tcp_write_space(struct sock *sk)
1523 {
1524 	/* from net/core/stream.c:sk_stream_write_space */
1525 	if (sk_stream_is_writeable(sk))
1526 		xs_write_space(sk);
1527 }
1528 
1529 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1530 {
1531 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1532 	struct sock *sk = transport->inet;
1533 
1534 	if (transport->rcvsize) {
1535 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1536 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1537 	}
1538 	if (transport->sndsize) {
1539 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1540 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1541 		sk->sk_write_space(sk);
1542 	}
1543 }
1544 
1545 /**
1546  * xs_udp_set_buffer_size - set send and receive limits
1547  * @xprt: generic transport
1548  * @sndsize: requested size of send buffer, in bytes
1549  * @rcvsize: requested size of receive buffer, in bytes
1550  *
1551  * Set socket send and receive buffer size limits.
1552  */
1553 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1554 {
1555 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1556 
1557 	transport->sndsize = 0;
1558 	if (sndsize)
1559 		transport->sndsize = sndsize + 1024;
1560 	transport->rcvsize = 0;
1561 	if (rcvsize)
1562 		transport->rcvsize = rcvsize + 1024;
1563 
1564 	xs_udp_do_set_buffer_size(xprt);
1565 }
1566 
1567 /**
1568  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1569  * @xprt: controlling transport
1570  * @task: task that timed out
1571  *
1572  * Adjust the congestion window after a retransmit timeout has occurred.
1573  */
1574 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1575 {
1576 	spin_lock(&xprt->transport_lock);
1577 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1578 	spin_unlock(&xprt->transport_lock);
1579 }
1580 
1581 static int xs_get_random_port(void)
1582 {
1583 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1584 	unsigned short range;
1585 	unsigned short rand;
1586 
1587 	if (max < min)
1588 		return -EADDRINUSE;
1589 	range = max - min + 1;
1590 	rand = (unsigned short) prandom_u32() % range;
1591 	return rand + min;
1592 }
1593 
1594 static unsigned short xs_sock_getport(struct socket *sock)
1595 {
1596 	struct sockaddr_storage buf;
1597 	unsigned short port = 0;
1598 
1599 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1600 		goto out;
1601 	switch (buf.ss_family) {
1602 	case AF_INET6:
1603 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1604 		break;
1605 	case AF_INET:
1606 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1607 	}
1608 out:
1609 	return port;
1610 }
1611 
1612 /**
1613  * xs_set_port - reset the port number in the remote endpoint address
1614  * @xprt: generic transport
1615  * @port: new port number
1616  *
1617  */
1618 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1619 {
1620 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1621 
1622 	rpc_set_port(xs_addr(xprt), port);
1623 	xs_update_peer_port(xprt);
1624 }
1625 
1626 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1627 {
1628 	if (transport->srcport == 0 && transport->xprt.reuseport)
1629 		transport->srcport = xs_sock_getport(sock);
1630 }
1631 
1632 static int xs_get_srcport(struct sock_xprt *transport)
1633 {
1634 	int port = transport->srcport;
1635 
1636 	if (port == 0 && transport->xprt.resvport)
1637 		port = xs_get_random_port();
1638 	return port;
1639 }
1640 
1641 static unsigned short xs_sock_srcport(struct rpc_xprt *xprt)
1642 {
1643 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1644 	unsigned short ret = 0;
1645 	mutex_lock(&sock->recv_mutex);
1646 	if (sock->sock)
1647 		ret = xs_sock_getport(sock->sock);
1648 	mutex_unlock(&sock->recv_mutex);
1649 	return ret;
1650 }
1651 
1652 static int xs_sock_srcaddr(struct rpc_xprt *xprt, char *buf, size_t buflen)
1653 {
1654 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1655 	union {
1656 		struct sockaddr sa;
1657 		struct sockaddr_storage st;
1658 	} saddr;
1659 	int ret = -ENOTCONN;
1660 
1661 	mutex_lock(&sock->recv_mutex);
1662 	if (sock->sock) {
1663 		ret = kernel_getsockname(sock->sock, &saddr.sa);
1664 		if (ret >= 0)
1665 			ret = snprintf(buf, buflen, "%pISc", &saddr.sa);
1666 	}
1667 	mutex_unlock(&sock->recv_mutex);
1668 	return ret;
1669 }
1670 
1671 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1672 {
1673 	if (transport->srcport != 0)
1674 		transport->srcport = 0;
1675 	if (!transport->xprt.resvport)
1676 		return 0;
1677 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1678 		return xprt_max_resvport;
1679 	return --port;
1680 }
1681 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1682 {
1683 	struct sockaddr_storage myaddr;
1684 	int err, nloop = 0;
1685 	int port = xs_get_srcport(transport);
1686 	unsigned short last;
1687 
1688 	/*
1689 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1690 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1691 	 * port selection happen implicitly when the socket is used
1692 	 * (for example at connect time).
1693 	 *
1694 	 * This ensures that we can continue to establish TCP
1695 	 * connections even when all local ephemeral ports are already
1696 	 * a part of some TCP connection.  This makes no difference
1697 	 * for UDP sockets, but also doesn't harm them.
1698 	 *
1699 	 * If we're asking for any reserved port (i.e. port == 0 &&
1700 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1701 	 * ensure that port is non-zero and we will bind as needed.
1702 	 */
1703 	if (port <= 0)
1704 		return port;
1705 
1706 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1707 	do {
1708 		rpc_set_port((struct sockaddr *)&myaddr, port);
1709 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1710 				transport->xprt.addrlen);
1711 		if (err == 0) {
1712 			if (transport->xprt.reuseport)
1713 				transport->srcport = port;
1714 			break;
1715 		}
1716 		last = port;
1717 		port = xs_next_srcport(transport, port);
1718 		if (port > last)
1719 			nloop++;
1720 	} while (err == -EADDRINUSE && nloop != 2);
1721 
1722 	if (myaddr.ss_family == AF_INET)
1723 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1724 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1725 				port, err ? "failed" : "ok", err);
1726 	else
1727 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1728 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1729 				port, err ? "failed" : "ok", err);
1730 	return err;
1731 }
1732 
1733 /*
1734  * We don't support autobind on AF_LOCAL sockets
1735  */
1736 static void xs_local_rpcbind(struct rpc_task *task)
1737 {
1738 	xprt_set_bound(task->tk_xprt);
1739 }
1740 
1741 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1742 {
1743 }
1744 
1745 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1746 static struct lock_class_key xs_key[3];
1747 static struct lock_class_key xs_slock_key[3];
1748 
1749 static inline void xs_reclassify_socketu(struct socket *sock)
1750 {
1751 	struct sock *sk = sock->sk;
1752 
1753 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1754 		&xs_slock_key[0], "sk_lock-AF_LOCAL-RPC", &xs_key[0]);
1755 }
1756 
1757 static inline void xs_reclassify_socket4(struct socket *sock)
1758 {
1759 	struct sock *sk = sock->sk;
1760 
1761 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1762 		&xs_slock_key[1], "sk_lock-AF_INET-RPC", &xs_key[1]);
1763 }
1764 
1765 static inline void xs_reclassify_socket6(struct socket *sock)
1766 {
1767 	struct sock *sk = sock->sk;
1768 
1769 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1770 		&xs_slock_key[2], "sk_lock-AF_INET6-RPC", &xs_key[2]);
1771 }
1772 
1773 static inline void xs_reclassify_socket(int family, struct socket *sock)
1774 {
1775 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1776 		return;
1777 
1778 	switch (family) {
1779 	case AF_LOCAL:
1780 		xs_reclassify_socketu(sock);
1781 		break;
1782 	case AF_INET:
1783 		xs_reclassify_socket4(sock);
1784 		break;
1785 	case AF_INET6:
1786 		xs_reclassify_socket6(sock);
1787 		break;
1788 	}
1789 }
1790 #else
1791 static inline void xs_reclassify_socket(int family, struct socket *sock)
1792 {
1793 }
1794 #endif
1795 
1796 static void xs_dummy_setup_socket(struct work_struct *work)
1797 {
1798 }
1799 
1800 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1801 		struct sock_xprt *transport, int family, int type,
1802 		int protocol, bool reuseport)
1803 {
1804 	struct file *filp;
1805 	struct socket *sock;
1806 	int err;
1807 
1808 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1809 	if (err < 0) {
1810 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1811 				protocol, -err);
1812 		goto out;
1813 	}
1814 	xs_reclassify_socket(family, sock);
1815 
1816 	if (reuseport)
1817 		sock_set_reuseport(sock->sk);
1818 
1819 	err = xs_bind(transport, sock);
1820 	if (err) {
1821 		sock_release(sock);
1822 		goto out;
1823 	}
1824 
1825 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1826 	if (IS_ERR(filp))
1827 		return ERR_CAST(filp);
1828 	transport->file = filp;
1829 
1830 	return sock;
1831 out:
1832 	return ERR_PTR(err);
1833 }
1834 
1835 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1836 				      struct socket *sock)
1837 {
1838 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1839 									xprt);
1840 
1841 	if (!transport->inet) {
1842 		struct sock *sk = sock->sk;
1843 
1844 		lock_sock(sk);
1845 
1846 		xs_save_old_callbacks(transport, sk);
1847 
1848 		sk->sk_user_data = xprt;
1849 		sk->sk_data_ready = xs_data_ready;
1850 		sk->sk_write_space = xs_udp_write_space;
1851 		sk->sk_error_report = xs_error_report;
1852 
1853 		xprt_clear_connected(xprt);
1854 
1855 		/* Reset to new socket */
1856 		transport->sock = sock;
1857 		transport->inet = sk;
1858 
1859 		release_sock(sk);
1860 	}
1861 
1862 	xs_stream_start_connect(transport);
1863 
1864 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1865 }
1866 
1867 /**
1868  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1869  * @transport: socket transport to connect
1870  */
1871 static int xs_local_setup_socket(struct sock_xprt *transport)
1872 {
1873 	struct rpc_xprt *xprt = &transport->xprt;
1874 	struct file *filp;
1875 	struct socket *sock;
1876 	int status;
1877 
1878 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1879 					SOCK_STREAM, 0, &sock, 1);
1880 	if (status < 0) {
1881 		dprintk("RPC:       can't create AF_LOCAL "
1882 			"transport socket (%d).\n", -status);
1883 		goto out;
1884 	}
1885 	xs_reclassify_socket(AF_LOCAL, sock);
1886 
1887 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1888 	if (IS_ERR(filp)) {
1889 		status = PTR_ERR(filp);
1890 		goto out;
1891 	}
1892 	transport->file = filp;
1893 
1894 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1895 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1896 
1897 	status = xs_local_finish_connecting(xprt, sock);
1898 	trace_rpc_socket_connect(xprt, sock, status);
1899 	switch (status) {
1900 	case 0:
1901 		dprintk("RPC:       xprt %p connected to %s\n",
1902 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1903 		xprt->stat.connect_count++;
1904 		xprt->stat.connect_time += (long)jiffies -
1905 					   xprt->stat.connect_start;
1906 		xprt_set_connected(xprt);
1907 		break;
1908 	case -ENOBUFS:
1909 		break;
1910 	case -ENOENT:
1911 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1912 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1913 		break;
1914 	case -ECONNREFUSED:
1915 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1916 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1917 		break;
1918 	default:
1919 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1920 				__func__, -status,
1921 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1922 	}
1923 
1924 out:
1925 	xprt_clear_connecting(xprt);
1926 	xprt_wake_pending_tasks(xprt, status);
1927 	return status;
1928 }
1929 
1930 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1931 {
1932 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1933 	int ret;
1934 
1935 	if (RPC_IS_ASYNC(task)) {
1936 		/*
1937 		 * We want the AF_LOCAL connect to be resolved in the
1938 		 * filesystem namespace of the process making the rpc
1939 		 * call.  Thus we connect synchronously.
1940 		 *
1941 		 * If we want to support asynchronous AF_LOCAL calls,
1942 		 * we'll need to figure out how to pass a namespace to
1943 		 * connect.
1944 		 */
1945 		task->tk_rpc_status = -ENOTCONN;
1946 		rpc_exit(task, -ENOTCONN);
1947 		return;
1948 	}
1949 	ret = xs_local_setup_socket(transport);
1950 	if (ret && !RPC_IS_SOFTCONN(task))
1951 		msleep_interruptible(15000);
1952 }
1953 
1954 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1955 /*
1956  * Note that this should be called with XPRT_LOCKED held, or recv_mutex
1957  * held, or when we otherwise know that we have exclusive access to the
1958  * socket, to guard against races with xs_reset_transport.
1959  */
1960 static void xs_set_memalloc(struct rpc_xprt *xprt)
1961 {
1962 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1963 			xprt);
1964 
1965 	/*
1966 	 * If there's no sock, then we have nothing to set. The
1967 	 * reconnecting process will get it for us.
1968 	 */
1969 	if (!transport->inet)
1970 		return;
1971 	if (atomic_read(&xprt->swapper))
1972 		sk_set_memalloc(transport->inet);
1973 }
1974 
1975 /**
1976  * xs_enable_swap - Tag this transport as being used for swap.
1977  * @xprt: transport to tag
1978  *
1979  * Take a reference to this transport on behalf of the rpc_clnt, and
1980  * optionally mark it for swapping if it wasn't already.
1981  */
1982 static int
1983 xs_enable_swap(struct rpc_xprt *xprt)
1984 {
1985 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1986 
1987 	mutex_lock(&xs->recv_mutex);
1988 	if (atomic_inc_return(&xprt->swapper) == 1 &&
1989 	    xs->inet)
1990 		sk_set_memalloc(xs->inet);
1991 	mutex_unlock(&xs->recv_mutex);
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 	mutex_lock(&xs->recv_mutex);
2008 	if (atomic_dec_and_test(&xprt->swapper) &&
2009 	    xs->inet)
2010 		sk_clear_memalloc(xs->inet);
2011 	mutex_unlock(&xs->recv_mutex);
2012 }
2013 #else
2014 static void xs_set_memalloc(struct rpc_xprt *xprt)
2015 {
2016 }
2017 
2018 static int
2019 xs_enable_swap(struct rpc_xprt *xprt)
2020 {
2021 	return -EINVAL;
2022 }
2023 
2024 static void
2025 xs_disable_swap(struct rpc_xprt *xprt)
2026 {
2027 }
2028 #endif
2029 
2030 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2031 {
2032 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2033 
2034 	if (!transport->inet) {
2035 		struct sock *sk = sock->sk;
2036 
2037 		lock_sock(sk);
2038 
2039 		xs_save_old_callbacks(transport, sk);
2040 
2041 		sk->sk_user_data = xprt;
2042 		sk->sk_data_ready = xs_data_ready;
2043 		sk->sk_write_space = xs_udp_write_space;
2044 
2045 		xprt_set_connected(xprt);
2046 
2047 		/* Reset to new socket */
2048 		transport->sock = sock;
2049 		transport->inet = sk;
2050 
2051 		xs_set_memalloc(xprt);
2052 
2053 		release_sock(sk);
2054 	}
2055 	xs_udp_do_set_buffer_size(xprt);
2056 
2057 	xprt->stat.connect_start = jiffies;
2058 }
2059 
2060 static void xs_udp_setup_socket(struct work_struct *work)
2061 {
2062 	struct sock_xprt *transport =
2063 		container_of(work, struct sock_xprt, connect_worker.work);
2064 	struct rpc_xprt *xprt = &transport->xprt;
2065 	struct socket *sock;
2066 	int status = -EIO;
2067 	unsigned int pflags = current->flags;
2068 
2069 	if (atomic_read(&xprt->swapper))
2070 		current->flags |= PF_MEMALLOC;
2071 	sock = xs_create_sock(xprt, transport,
2072 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2073 			IPPROTO_UDP, false);
2074 	if (IS_ERR(sock))
2075 		goto out;
2076 
2077 	dprintk("RPC:       worker connecting xprt %p via %s to "
2078 				"%s (port %s)\n", xprt,
2079 			xprt->address_strings[RPC_DISPLAY_PROTO],
2080 			xprt->address_strings[RPC_DISPLAY_ADDR],
2081 			xprt->address_strings[RPC_DISPLAY_PORT]);
2082 
2083 	xs_udp_finish_connecting(xprt, sock);
2084 	trace_rpc_socket_connect(xprt, sock, 0);
2085 	status = 0;
2086 out:
2087 	xprt_clear_connecting(xprt);
2088 	xprt_unlock_connect(xprt, transport);
2089 	xprt_wake_pending_tasks(xprt, status);
2090 	current_restore_flags(pflags, PF_MEMALLOC);
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 	if (!xprt->reuseport) {
2109 		xs_close(xprt);
2110 		return;
2111 	}
2112 	switch (skst) {
2113 	case TCP_FIN_WAIT1:
2114 	case TCP_FIN_WAIT2:
2115 		break;
2116 	case TCP_ESTABLISHED:
2117 	case TCP_CLOSE_WAIT:
2118 		kernel_sock_shutdown(sock, SHUT_RDWR);
2119 		trace_rpc_socket_shutdown(xprt, sock);
2120 		break;
2121 	default:
2122 		xs_reset_transport(transport);
2123 	}
2124 }
2125 
2126 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2127 		struct socket *sock)
2128 {
2129 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2130 	unsigned int keepidle;
2131 	unsigned int keepcnt;
2132 	unsigned int timeo;
2133 
2134 	spin_lock(&xprt->transport_lock);
2135 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2136 	keepcnt = xprt->timeout->to_retries + 1;
2137 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2138 		(xprt->timeout->to_retries + 1);
2139 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2140 	spin_unlock(&xprt->transport_lock);
2141 
2142 	/* TCP Keepalive options */
2143 	sock_set_keepalive(sock->sk);
2144 	tcp_sock_set_keepidle(sock->sk, keepidle);
2145 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2146 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2147 
2148 	/* TCP user timeout (see RFC5482) */
2149 	tcp_sock_set_user_timeout(sock->sk, timeo);
2150 }
2151 
2152 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2153 		unsigned long connect_timeout,
2154 		unsigned long reconnect_timeout)
2155 {
2156 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2157 	struct rpc_timeout to;
2158 	unsigned long initval;
2159 
2160 	spin_lock(&xprt->transport_lock);
2161 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2162 		xprt->max_reconnect_timeout = reconnect_timeout;
2163 	if (connect_timeout < xprt->connect_timeout) {
2164 		memcpy(&to, xprt->timeout, sizeof(to));
2165 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2166 		/* Arbitrary lower limit */
2167 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2168 			initval = XS_TCP_INIT_REEST_TO << 1;
2169 		to.to_initval = initval;
2170 		to.to_maxval = initval;
2171 		memcpy(&transport->tcp_timeout, &to,
2172 				sizeof(transport->tcp_timeout));
2173 		xprt->timeout = &transport->tcp_timeout;
2174 		xprt->connect_timeout = connect_timeout;
2175 	}
2176 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2177 	spin_unlock(&xprt->transport_lock);
2178 }
2179 
2180 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2181 {
2182 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2183 
2184 	if (!transport->inet) {
2185 		struct sock *sk = sock->sk;
2186 
2187 		/* Avoid temporary address, they are bad for long-lived
2188 		 * connections such as NFS mounts.
2189 		 * RFC4941, section 3.6 suggests that:
2190 		 *    Individual applications, which have specific
2191 		 *    knowledge about the normal duration of connections,
2192 		 *    MAY override this as appropriate.
2193 		 */
2194 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2195 			ip6_sock_set_addr_preferences(sk,
2196 				IPV6_PREFER_SRC_PUBLIC);
2197 		}
2198 
2199 		xs_tcp_set_socket_timeouts(xprt, sock);
2200 		tcp_sock_set_nodelay(sk);
2201 
2202 		lock_sock(sk);
2203 
2204 		xs_save_old_callbacks(transport, sk);
2205 
2206 		sk->sk_user_data = xprt;
2207 		sk->sk_data_ready = xs_data_ready;
2208 		sk->sk_state_change = xs_tcp_state_change;
2209 		sk->sk_write_space = xs_tcp_write_space;
2210 		sk->sk_error_report = xs_error_report;
2211 
2212 		/* socket options */
2213 		sock_reset_flag(sk, SOCK_LINGER);
2214 
2215 		xprt_clear_connected(xprt);
2216 
2217 		/* Reset to new socket */
2218 		transport->sock = sock;
2219 		transport->inet = sk;
2220 
2221 		release_sock(sk);
2222 	}
2223 
2224 	if (!xprt_bound(xprt))
2225 		return -ENOTCONN;
2226 
2227 	xs_set_memalloc(xprt);
2228 
2229 	xs_stream_start_connect(transport);
2230 
2231 	/* Tell the socket layer to start connecting... */
2232 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2233 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2234 }
2235 
2236 /**
2237  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2238  * @work: queued work item
2239  *
2240  * Invoked by a work queue tasklet.
2241  */
2242 static void xs_tcp_setup_socket(struct work_struct *work)
2243 {
2244 	struct sock_xprt *transport =
2245 		container_of(work, struct sock_xprt, connect_worker.work);
2246 	struct socket *sock = transport->sock;
2247 	struct rpc_xprt *xprt = &transport->xprt;
2248 	int status;
2249 	unsigned int pflags = current->flags;
2250 
2251 	if (atomic_read(&xprt->swapper))
2252 		current->flags |= PF_MEMALLOC;
2253 
2254 	if (xprt_connected(xprt))
2255 		goto out;
2256 	if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,
2257 			       &transport->sock_state) ||
2258 	    !sock) {
2259 		xs_reset_transport(transport);
2260 		sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
2261 				      SOCK_STREAM, IPPROTO_TCP, true);
2262 		if (IS_ERR(sock)) {
2263 			xprt_wake_pending_tasks(xprt, PTR_ERR(sock));
2264 			goto out;
2265 		}
2266 	}
2267 
2268 	dprintk("RPC:       worker connecting xprt %p via %s to "
2269 				"%s (port %s)\n", xprt,
2270 			xprt->address_strings[RPC_DISPLAY_PROTO],
2271 			xprt->address_strings[RPC_DISPLAY_ADDR],
2272 			xprt->address_strings[RPC_DISPLAY_PORT]);
2273 
2274 	status = xs_tcp_finish_connecting(xprt, sock);
2275 	trace_rpc_socket_connect(xprt, sock, status);
2276 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2277 			xprt, -status, xprt_connected(xprt),
2278 			sock->sk->sk_state);
2279 	switch (status) {
2280 	case 0:
2281 	case -EINPROGRESS:
2282 		/* SYN_SENT! */
2283 		set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
2284 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2285 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2286 		fallthrough;
2287 	case -EALREADY:
2288 		goto out_unlock;
2289 	case -EADDRNOTAVAIL:
2290 		/* Source port number is unavailable. Try a new one! */
2291 		transport->srcport = 0;
2292 		status = -EAGAIN;
2293 		break;
2294 	case -EINVAL:
2295 		/* Happens, for instance, if the user specified a link
2296 		 * local IPv6 address without a scope-id.
2297 		 */
2298 	case -ECONNREFUSED:
2299 	case -ECONNRESET:
2300 	case -ENETDOWN:
2301 	case -ENETUNREACH:
2302 	case -EHOSTUNREACH:
2303 	case -EADDRINUSE:
2304 	case -ENOBUFS:
2305 		break;
2306 	default:
2307 		printk("%s: connect returned unhandled error %d\n",
2308 			__func__, status);
2309 		status = -EAGAIN;
2310 	}
2311 
2312 	/* xs_tcp_force_close() wakes tasks with a fixed error code.
2313 	 * We need to wake them first to ensure the correct error code.
2314 	 */
2315 	xprt_wake_pending_tasks(xprt, status);
2316 	xs_tcp_force_close(xprt);
2317 out:
2318 	xprt_clear_connecting(xprt);
2319 out_unlock:
2320 	xprt_unlock_connect(xprt, transport);
2321 	current_restore_flags(pflags, PF_MEMALLOC);
2322 }
2323 
2324 /**
2325  * xs_connect - connect a socket to a remote endpoint
2326  * @xprt: pointer to transport structure
2327  * @task: address of RPC task that manages state of connect request
2328  *
2329  * TCP: If the remote end dropped the connection, delay reconnecting.
2330  *
2331  * UDP socket connects are synchronous, but we use a work queue anyway
2332  * to guarantee that even unprivileged user processes can set up a
2333  * socket on a privileged port.
2334  *
2335  * If a UDP socket connect fails, the delay behavior here prevents
2336  * retry floods (hard mounts).
2337  */
2338 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2339 {
2340 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2341 	unsigned long delay = 0;
2342 
2343 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2344 
2345 	if (transport->sock != NULL) {
2346 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2347 			"seconds\n", xprt, xprt->reestablish_timeout / HZ);
2348 
2349 		delay = xprt_reconnect_delay(xprt);
2350 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2351 
2352 	} else
2353 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2354 
2355 	queue_delayed_work(xprtiod_workqueue,
2356 			&transport->connect_worker,
2357 			delay);
2358 }
2359 
2360 static void xs_wake_disconnect(struct sock_xprt *transport)
2361 {
2362 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2363 		xs_tcp_force_close(&transport->xprt);
2364 }
2365 
2366 static void xs_wake_write(struct sock_xprt *transport)
2367 {
2368 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2369 		xprt_write_space(&transport->xprt);
2370 }
2371 
2372 static void xs_wake_error(struct sock_xprt *transport)
2373 {
2374 	int sockerr;
2375 
2376 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2377 		return;
2378 	mutex_lock(&transport->recv_mutex);
2379 	if (transport->sock == NULL)
2380 		goto out;
2381 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2382 		goto out;
2383 	sockerr = xchg(&transport->xprt_err, 0);
2384 	if (sockerr < 0)
2385 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2386 out:
2387 	mutex_unlock(&transport->recv_mutex);
2388 }
2389 
2390 static void xs_wake_pending(struct sock_xprt *transport)
2391 {
2392 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2393 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2394 }
2395 
2396 static void xs_error_handle(struct work_struct *work)
2397 {
2398 	struct sock_xprt *transport = container_of(work,
2399 			struct sock_xprt, error_worker);
2400 
2401 	xs_wake_disconnect(transport);
2402 	xs_wake_write(transport);
2403 	xs_wake_error(transport);
2404 	xs_wake_pending(transport);
2405 }
2406 
2407 /**
2408  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2409  * @xprt: rpc_xprt struct containing statistics
2410  * @seq: output file
2411  *
2412  */
2413 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2414 {
2415 	long idle_time = 0;
2416 
2417 	if (xprt_connected(xprt))
2418 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2419 
2420 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2421 			"%llu %llu %lu %llu %llu\n",
2422 			xprt->stat.bind_count,
2423 			xprt->stat.connect_count,
2424 			xprt->stat.connect_time / HZ,
2425 			idle_time,
2426 			xprt->stat.sends,
2427 			xprt->stat.recvs,
2428 			xprt->stat.bad_xids,
2429 			xprt->stat.req_u,
2430 			xprt->stat.bklog_u,
2431 			xprt->stat.max_slots,
2432 			xprt->stat.sending_u,
2433 			xprt->stat.pending_u);
2434 }
2435 
2436 /**
2437  * xs_udp_print_stats - display UDP socket-specific stats
2438  * @xprt: rpc_xprt struct containing statistics
2439  * @seq: output file
2440  *
2441  */
2442 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2443 {
2444 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2445 
2446 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2447 			"%lu %llu %llu\n",
2448 			transport->srcport,
2449 			xprt->stat.bind_count,
2450 			xprt->stat.sends,
2451 			xprt->stat.recvs,
2452 			xprt->stat.bad_xids,
2453 			xprt->stat.req_u,
2454 			xprt->stat.bklog_u,
2455 			xprt->stat.max_slots,
2456 			xprt->stat.sending_u,
2457 			xprt->stat.pending_u);
2458 }
2459 
2460 /**
2461  * xs_tcp_print_stats - display TCP socket-specific stats
2462  * @xprt: rpc_xprt struct containing statistics
2463  * @seq: output file
2464  *
2465  */
2466 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2467 {
2468 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2469 	long idle_time = 0;
2470 
2471 	if (xprt_connected(xprt))
2472 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2473 
2474 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2475 			"%llu %llu %lu %llu %llu\n",
2476 			transport->srcport,
2477 			xprt->stat.bind_count,
2478 			xprt->stat.connect_count,
2479 			xprt->stat.connect_time / HZ,
2480 			idle_time,
2481 			xprt->stat.sends,
2482 			xprt->stat.recvs,
2483 			xprt->stat.bad_xids,
2484 			xprt->stat.req_u,
2485 			xprt->stat.bklog_u,
2486 			xprt->stat.max_slots,
2487 			xprt->stat.sending_u,
2488 			xprt->stat.pending_u);
2489 }
2490 
2491 /*
2492  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2493  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2494  * to use the server side send routines.
2495  */
2496 static int bc_malloc(struct rpc_task *task)
2497 {
2498 	struct rpc_rqst *rqst = task->tk_rqstp;
2499 	size_t size = rqst->rq_callsize;
2500 	struct page *page;
2501 	struct rpc_buffer *buf;
2502 
2503 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2504 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2505 			  size);
2506 		return -EINVAL;
2507 	}
2508 
2509 	page = alloc_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
2510 	if (!page)
2511 		return -ENOMEM;
2512 
2513 	buf = page_address(page);
2514 	buf->len = PAGE_SIZE;
2515 
2516 	rqst->rq_buffer = buf->data;
2517 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2518 	return 0;
2519 }
2520 
2521 /*
2522  * Free the space allocated in the bc_alloc routine
2523  */
2524 static void bc_free(struct rpc_task *task)
2525 {
2526 	void *buffer = task->tk_rqstp->rq_buffer;
2527 	struct rpc_buffer *buf;
2528 
2529 	buf = container_of(buffer, struct rpc_buffer, data);
2530 	free_page((unsigned long)buf);
2531 }
2532 
2533 static int bc_sendto(struct rpc_rqst *req)
2534 {
2535 	struct xdr_buf *xdr = &req->rq_snd_buf;
2536 	struct sock_xprt *transport =
2537 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2538 	struct msghdr msg = {
2539 		.msg_flags	= 0,
2540 	};
2541 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2542 					 (u32)xdr->len);
2543 	unsigned int sent = 0;
2544 	int err;
2545 
2546 	req->rq_xtime = ktime_get();
2547 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2548 	xdr_free_bvec(xdr);
2549 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2550 		return -EAGAIN;
2551 	return sent;
2552 }
2553 
2554 /**
2555  * bc_send_request - Send a backchannel Call on a TCP socket
2556  * @req: rpc_rqst containing Call message to be sent
2557  *
2558  * xpt_mutex ensures @rqstp's whole message is written to the socket
2559  * without interruption.
2560  *
2561  * Return values:
2562  *   %0 if the message was sent successfully
2563  *   %ENOTCONN if the message was not sent
2564  */
2565 static int bc_send_request(struct rpc_rqst *req)
2566 {
2567 	struct svc_xprt	*xprt;
2568 	int len;
2569 
2570 	/*
2571 	 * Get the server socket associated with this callback xprt
2572 	 */
2573 	xprt = req->rq_xprt->bc_xprt;
2574 
2575 	/*
2576 	 * Grab the mutex to serialize data as the connection is shared
2577 	 * with the fore channel
2578 	 */
2579 	mutex_lock(&xprt->xpt_mutex);
2580 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2581 		len = -ENOTCONN;
2582 	else
2583 		len = bc_sendto(req);
2584 	mutex_unlock(&xprt->xpt_mutex);
2585 
2586 	if (len > 0)
2587 		len = 0;
2588 
2589 	return len;
2590 }
2591 
2592 /*
2593  * The close routine. Since this is client initiated, we do nothing
2594  */
2595 
2596 static void bc_close(struct rpc_xprt *xprt)
2597 {
2598 	xprt_disconnect_done(xprt);
2599 }
2600 
2601 /*
2602  * The xprt destroy routine. Again, because this connection is client
2603  * initiated, we do nothing
2604  */
2605 
2606 static void bc_destroy(struct rpc_xprt *xprt)
2607 {
2608 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2609 
2610 	xs_xprt_free(xprt);
2611 	module_put(THIS_MODULE);
2612 }
2613 
2614 static const struct rpc_xprt_ops xs_local_ops = {
2615 	.reserve_xprt		= xprt_reserve_xprt,
2616 	.release_xprt		= xprt_release_xprt,
2617 	.alloc_slot		= xprt_alloc_slot,
2618 	.free_slot		= xprt_free_slot,
2619 	.rpcbind		= xs_local_rpcbind,
2620 	.set_port		= xs_local_set_port,
2621 	.connect		= xs_local_connect,
2622 	.buf_alloc		= rpc_malloc,
2623 	.buf_free		= rpc_free,
2624 	.prepare_request	= xs_stream_prepare_request,
2625 	.send_request		= xs_local_send_request,
2626 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2627 	.close			= xs_close,
2628 	.destroy		= xs_destroy,
2629 	.print_stats		= xs_local_print_stats,
2630 	.enable_swap		= xs_enable_swap,
2631 	.disable_swap		= xs_disable_swap,
2632 };
2633 
2634 static const struct rpc_xprt_ops xs_udp_ops = {
2635 	.set_buffer_size	= xs_udp_set_buffer_size,
2636 	.reserve_xprt		= xprt_reserve_xprt_cong,
2637 	.release_xprt		= xprt_release_xprt_cong,
2638 	.alloc_slot		= xprt_alloc_slot,
2639 	.free_slot		= xprt_free_slot,
2640 	.rpcbind		= rpcb_getport_async,
2641 	.set_port		= xs_set_port,
2642 	.connect		= xs_connect,
2643 	.get_srcaddr		= xs_sock_srcaddr,
2644 	.get_srcport		= xs_sock_srcport,
2645 	.buf_alloc		= rpc_malloc,
2646 	.buf_free		= rpc_free,
2647 	.send_request		= xs_udp_send_request,
2648 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2649 	.timer			= xs_udp_timer,
2650 	.release_request	= xprt_release_rqst_cong,
2651 	.close			= xs_close,
2652 	.destroy		= xs_destroy,
2653 	.print_stats		= xs_udp_print_stats,
2654 	.enable_swap		= xs_enable_swap,
2655 	.disable_swap		= xs_disable_swap,
2656 	.inject_disconnect	= xs_inject_disconnect,
2657 };
2658 
2659 static const struct rpc_xprt_ops xs_tcp_ops = {
2660 	.reserve_xprt		= xprt_reserve_xprt,
2661 	.release_xprt		= xprt_release_xprt,
2662 	.alloc_slot		= xprt_alloc_slot,
2663 	.free_slot		= xprt_free_slot,
2664 	.rpcbind		= rpcb_getport_async,
2665 	.set_port		= xs_set_port,
2666 	.connect		= xs_connect,
2667 	.get_srcaddr		= xs_sock_srcaddr,
2668 	.get_srcport		= xs_sock_srcport,
2669 	.buf_alloc		= rpc_malloc,
2670 	.buf_free		= rpc_free,
2671 	.prepare_request	= xs_stream_prepare_request,
2672 	.send_request		= xs_tcp_send_request,
2673 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2674 	.close			= xs_tcp_shutdown,
2675 	.destroy		= xs_destroy,
2676 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2677 	.print_stats		= xs_tcp_print_stats,
2678 	.enable_swap		= xs_enable_swap,
2679 	.disable_swap		= xs_disable_swap,
2680 	.inject_disconnect	= xs_inject_disconnect,
2681 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2682 	.bc_setup		= xprt_setup_bc,
2683 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2684 	.bc_num_slots		= xprt_bc_max_slots,
2685 	.bc_free_rqst		= xprt_free_bc_rqst,
2686 	.bc_destroy		= xprt_destroy_bc,
2687 #endif
2688 };
2689 
2690 /*
2691  * The rpc_xprt_ops for the server backchannel
2692  */
2693 
2694 static const struct rpc_xprt_ops bc_tcp_ops = {
2695 	.reserve_xprt		= xprt_reserve_xprt,
2696 	.release_xprt		= xprt_release_xprt,
2697 	.alloc_slot		= xprt_alloc_slot,
2698 	.free_slot		= xprt_free_slot,
2699 	.buf_alloc		= bc_malloc,
2700 	.buf_free		= bc_free,
2701 	.send_request		= bc_send_request,
2702 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2703 	.close			= bc_close,
2704 	.destroy		= bc_destroy,
2705 	.print_stats		= xs_tcp_print_stats,
2706 	.enable_swap		= xs_enable_swap,
2707 	.disable_swap		= xs_disable_swap,
2708 	.inject_disconnect	= xs_inject_disconnect,
2709 };
2710 
2711 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2712 {
2713 	static const struct sockaddr_in sin = {
2714 		.sin_family		= AF_INET,
2715 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2716 	};
2717 	static const struct sockaddr_in6 sin6 = {
2718 		.sin6_family		= AF_INET6,
2719 		.sin6_addr		= IN6ADDR_ANY_INIT,
2720 	};
2721 
2722 	switch (family) {
2723 	case AF_LOCAL:
2724 		break;
2725 	case AF_INET:
2726 		memcpy(sap, &sin, sizeof(sin));
2727 		break;
2728 	case AF_INET6:
2729 		memcpy(sap, &sin6, sizeof(sin6));
2730 		break;
2731 	default:
2732 		dprintk("RPC:       %s: Bad address family\n", __func__);
2733 		return -EAFNOSUPPORT;
2734 	}
2735 	return 0;
2736 }
2737 
2738 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2739 				      unsigned int slot_table_size,
2740 				      unsigned int max_slot_table_size)
2741 {
2742 	struct rpc_xprt *xprt;
2743 	struct sock_xprt *new;
2744 
2745 	if (args->addrlen > sizeof(xprt->addr)) {
2746 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2747 		return ERR_PTR(-EBADF);
2748 	}
2749 
2750 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2751 			max_slot_table_size);
2752 	if (xprt == NULL) {
2753 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2754 				"rpc_xprt\n");
2755 		return ERR_PTR(-ENOMEM);
2756 	}
2757 
2758 	new = container_of(xprt, struct sock_xprt, xprt);
2759 	mutex_init(&new->recv_mutex);
2760 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2761 	xprt->addrlen = args->addrlen;
2762 	if (args->srcaddr)
2763 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2764 	else {
2765 		int err;
2766 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2767 					(struct sockaddr *)&new->srcaddr);
2768 		if (err != 0) {
2769 			xprt_free(xprt);
2770 			return ERR_PTR(err);
2771 		}
2772 	}
2773 
2774 	return xprt;
2775 }
2776 
2777 static const struct rpc_timeout xs_local_default_timeout = {
2778 	.to_initval = 10 * HZ,
2779 	.to_maxval = 10 * HZ,
2780 	.to_retries = 2,
2781 };
2782 
2783 /**
2784  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2785  * @args: rpc transport creation arguments
2786  *
2787  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2788  */
2789 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2790 {
2791 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2792 	struct sock_xprt *transport;
2793 	struct rpc_xprt *xprt;
2794 	struct rpc_xprt *ret;
2795 
2796 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2797 			xprt_max_tcp_slot_table_entries);
2798 	if (IS_ERR(xprt))
2799 		return xprt;
2800 	transport = container_of(xprt, struct sock_xprt, xprt);
2801 
2802 	xprt->prot = 0;
2803 	xprt->xprt_class = &xs_local_transport;
2804 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2805 
2806 	xprt->bind_timeout = XS_BIND_TO;
2807 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2808 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2809 
2810 	xprt->ops = &xs_local_ops;
2811 	xprt->timeout = &xs_local_default_timeout;
2812 
2813 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2814 	INIT_WORK(&transport->error_worker, xs_error_handle);
2815 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2816 
2817 	switch (sun->sun_family) {
2818 	case AF_LOCAL:
2819 		if (sun->sun_path[0] != '/') {
2820 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2821 					sun->sun_path);
2822 			ret = ERR_PTR(-EINVAL);
2823 			goto out_err;
2824 		}
2825 		xprt_set_bound(xprt);
2826 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2827 		ret = ERR_PTR(xs_local_setup_socket(transport));
2828 		if (ret)
2829 			goto out_err;
2830 		break;
2831 	default:
2832 		ret = ERR_PTR(-EAFNOSUPPORT);
2833 		goto out_err;
2834 	}
2835 
2836 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2837 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2838 
2839 	if (try_module_get(THIS_MODULE))
2840 		return xprt;
2841 	ret = ERR_PTR(-EINVAL);
2842 out_err:
2843 	xs_xprt_free(xprt);
2844 	return ret;
2845 }
2846 
2847 static const struct rpc_timeout xs_udp_default_timeout = {
2848 	.to_initval = 5 * HZ,
2849 	.to_maxval = 30 * HZ,
2850 	.to_increment = 5 * HZ,
2851 	.to_retries = 5,
2852 };
2853 
2854 /**
2855  * xs_setup_udp - Set up transport to use a UDP socket
2856  * @args: rpc transport creation arguments
2857  *
2858  */
2859 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2860 {
2861 	struct sockaddr *addr = args->dstaddr;
2862 	struct rpc_xprt *xprt;
2863 	struct sock_xprt *transport;
2864 	struct rpc_xprt *ret;
2865 
2866 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2867 			xprt_udp_slot_table_entries);
2868 	if (IS_ERR(xprt))
2869 		return xprt;
2870 	transport = container_of(xprt, struct sock_xprt, xprt);
2871 
2872 	xprt->prot = IPPROTO_UDP;
2873 	xprt->xprt_class = &xs_udp_transport;
2874 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2875 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2876 
2877 	xprt->bind_timeout = XS_BIND_TO;
2878 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2879 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2880 
2881 	xprt->ops = &xs_udp_ops;
2882 
2883 	xprt->timeout = &xs_udp_default_timeout;
2884 
2885 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2886 	INIT_WORK(&transport->error_worker, xs_error_handle);
2887 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2888 
2889 	switch (addr->sa_family) {
2890 	case AF_INET:
2891 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2892 			xprt_set_bound(xprt);
2893 
2894 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2895 		break;
2896 	case AF_INET6:
2897 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2898 			xprt_set_bound(xprt);
2899 
2900 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2901 		break;
2902 	default:
2903 		ret = ERR_PTR(-EAFNOSUPPORT);
2904 		goto out_err;
2905 	}
2906 
2907 	if (xprt_bound(xprt))
2908 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2909 				xprt->address_strings[RPC_DISPLAY_ADDR],
2910 				xprt->address_strings[RPC_DISPLAY_PORT],
2911 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2912 	else
2913 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2914 				xprt->address_strings[RPC_DISPLAY_ADDR],
2915 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2916 
2917 	if (try_module_get(THIS_MODULE))
2918 		return xprt;
2919 	ret = ERR_PTR(-EINVAL);
2920 out_err:
2921 	xs_xprt_free(xprt);
2922 	return ret;
2923 }
2924 
2925 static const struct rpc_timeout xs_tcp_default_timeout = {
2926 	.to_initval = 60 * HZ,
2927 	.to_maxval = 60 * HZ,
2928 	.to_retries = 2,
2929 };
2930 
2931 /**
2932  * xs_setup_tcp - Set up transport to use a TCP socket
2933  * @args: rpc transport creation arguments
2934  *
2935  */
2936 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2937 {
2938 	struct sockaddr *addr = args->dstaddr;
2939 	struct rpc_xprt *xprt;
2940 	struct sock_xprt *transport;
2941 	struct rpc_xprt *ret;
2942 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2943 
2944 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2945 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2946 
2947 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2948 			max_slot_table_size);
2949 	if (IS_ERR(xprt))
2950 		return xprt;
2951 	transport = container_of(xprt, struct sock_xprt, xprt);
2952 
2953 	xprt->prot = IPPROTO_TCP;
2954 	xprt->xprt_class = &xs_tcp_transport;
2955 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2956 
2957 	xprt->bind_timeout = XS_BIND_TO;
2958 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2959 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2960 
2961 	xprt->ops = &xs_tcp_ops;
2962 	xprt->timeout = &xs_tcp_default_timeout;
2963 
2964 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2965 	xprt->connect_timeout = xprt->timeout->to_initval *
2966 		(xprt->timeout->to_retries + 1);
2967 
2968 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2969 	INIT_WORK(&transport->error_worker, xs_error_handle);
2970 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2971 
2972 	switch (addr->sa_family) {
2973 	case AF_INET:
2974 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2975 			xprt_set_bound(xprt);
2976 
2977 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2978 		break;
2979 	case AF_INET6:
2980 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2981 			xprt_set_bound(xprt);
2982 
2983 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2984 		break;
2985 	default:
2986 		ret = ERR_PTR(-EAFNOSUPPORT);
2987 		goto out_err;
2988 	}
2989 
2990 	if (xprt_bound(xprt))
2991 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2992 				xprt->address_strings[RPC_DISPLAY_ADDR],
2993 				xprt->address_strings[RPC_DISPLAY_PORT],
2994 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2995 	else
2996 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2997 				xprt->address_strings[RPC_DISPLAY_ADDR],
2998 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2999 
3000 	if (try_module_get(THIS_MODULE))
3001 		return xprt;
3002 	ret = ERR_PTR(-EINVAL);
3003 out_err:
3004 	xs_xprt_free(xprt);
3005 	return ret;
3006 }
3007 
3008 /**
3009  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3010  * @args: rpc transport creation arguments
3011  *
3012  */
3013 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3014 {
3015 	struct sockaddr *addr = args->dstaddr;
3016 	struct rpc_xprt *xprt;
3017 	struct sock_xprt *transport;
3018 	struct svc_sock *bc_sock;
3019 	struct rpc_xprt *ret;
3020 
3021 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3022 			xprt_tcp_slot_table_entries);
3023 	if (IS_ERR(xprt))
3024 		return xprt;
3025 	transport = container_of(xprt, struct sock_xprt, xprt);
3026 
3027 	xprt->prot = IPPROTO_TCP;
3028 	xprt->xprt_class = &xs_bc_tcp_transport;
3029 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3030 	xprt->timeout = &xs_tcp_default_timeout;
3031 
3032 	/* backchannel */
3033 	xprt_set_bound(xprt);
3034 	xprt->bind_timeout = 0;
3035 	xprt->reestablish_timeout = 0;
3036 	xprt->idle_timeout = 0;
3037 
3038 	xprt->ops = &bc_tcp_ops;
3039 
3040 	switch (addr->sa_family) {
3041 	case AF_INET:
3042 		xs_format_peer_addresses(xprt, "tcp",
3043 					 RPCBIND_NETID_TCP);
3044 		break;
3045 	case AF_INET6:
3046 		xs_format_peer_addresses(xprt, "tcp",
3047 				   RPCBIND_NETID_TCP6);
3048 		break;
3049 	default:
3050 		ret = ERR_PTR(-EAFNOSUPPORT);
3051 		goto out_err;
3052 	}
3053 
3054 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3055 			xprt->address_strings[RPC_DISPLAY_ADDR],
3056 			xprt->address_strings[RPC_DISPLAY_PORT],
3057 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3058 
3059 	/*
3060 	 * Once we've associated a backchannel xprt with a connection,
3061 	 * we want to keep it around as long as the connection lasts,
3062 	 * in case we need to start using it for a backchannel again;
3063 	 * this reference won't be dropped until bc_xprt is destroyed.
3064 	 */
3065 	xprt_get(xprt);
3066 	args->bc_xprt->xpt_bc_xprt = xprt;
3067 	xprt->bc_xprt = args->bc_xprt;
3068 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3069 	transport->sock = bc_sock->sk_sock;
3070 	transport->inet = bc_sock->sk_sk;
3071 
3072 	/*
3073 	 * Since we don't want connections for the backchannel, we set
3074 	 * the xprt status to connected
3075 	 */
3076 	xprt_set_connected(xprt);
3077 
3078 	if (try_module_get(THIS_MODULE))
3079 		return xprt;
3080 
3081 	args->bc_xprt->xpt_bc_xprt = NULL;
3082 	args->bc_xprt->xpt_bc_xps = NULL;
3083 	xprt_put(xprt);
3084 	ret = ERR_PTR(-EINVAL);
3085 out_err:
3086 	xs_xprt_free(xprt);
3087 	return ret;
3088 }
3089 
3090 static struct xprt_class	xs_local_transport = {
3091 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3092 	.name		= "named UNIX socket",
3093 	.owner		= THIS_MODULE,
3094 	.ident		= XPRT_TRANSPORT_LOCAL,
3095 	.setup		= xs_setup_local,
3096 	.netid		= { "" },
3097 };
3098 
3099 static struct xprt_class	xs_udp_transport = {
3100 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3101 	.name		= "udp",
3102 	.owner		= THIS_MODULE,
3103 	.ident		= XPRT_TRANSPORT_UDP,
3104 	.setup		= xs_setup_udp,
3105 	.netid		= { "udp", "udp6", "" },
3106 };
3107 
3108 static struct xprt_class	xs_tcp_transport = {
3109 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3110 	.name		= "tcp",
3111 	.owner		= THIS_MODULE,
3112 	.ident		= XPRT_TRANSPORT_TCP,
3113 	.setup		= xs_setup_tcp,
3114 	.netid		= { "tcp", "tcp6", "" },
3115 };
3116 
3117 static struct xprt_class	xs_bc_tcp_transport = {
3118 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3119 	.name		= "tcp NFSv4.1 backchannel",
3120 	.owner		= THIS_MODULE,
3121 	.ident		= XPRT_TRANSPORT_BC_TCP,
3122 	.setup		= xs_setup_bc_tcp,
3123 	.netid		= { "" },
3124 };
3125 
3126 /**
3127  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3128  *
3129  */
3130 int init_socket_xprt(void)
3131 {
3132 	if (!sunrpc_table_header)
3133 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3134 
3135 	xprt_register_transport(&xs_local_transport);
3136 	xprt_register_transport(&xs_udp_transport);
3137 	xprt_register_transport(&xs_tcp_transport);
3138 	xprt_register_transport(&xs_bc_tcp_transport);
3139 
3140 	return 0;
3141 }
3142 
3143 /**
3144  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3145  *
3146  */
3147 void cleanup_socket_xprt(void)
3148 {
3149 	if (sunrpc_table_header) {
3150 		unregister_sysctl_table(sunrpc_table_header);
3151 		sunrpc_table_header = NULL;
3152 	}
3153 
3154 	xprt_unregister_transport(&xs_local_transport);
3155 	xprt_unregister_transport(&xs_udp_transport);
3156 	xprt_unregister_transport(&xs_tcp_transport);
3157 	xprt_unregister_transport(&xs_bc_tcp_transport);
3158 }
3159 
3160 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3161 {
3162 	return param_set_uint_minmax(val, kp,
3163 			RPC_MIN_RESVPORT,
3164 			RPC_MAX_RESVPORT);
3165 }
3166 
3167 static const struct kernel_param_ops param_ops_portnr = {
3168 	.set = param_set_portnr,
3169 	.get = param_get_uint,
3170 };
3171 
3172 #define param_check_portnr(name, p) \
3173 	__param_check(name, p, unsigned int);
3174 
3175 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3176 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3177 
3178 static int param_set_slot_table_size(const char *val,
3179 				     const struct kernel_param *kp)
3180 {
3181 	return param_set_uint_minmax(val, kp,
3182 			RPC_MIN_SLOT_TABLE,
3183 			RPC_MAX_SLOT_TABLE);
3184 }
3185 
3186 static const struct kernel_param_ops param_ops_slot_table_size = {
3187 	.set = param_set_slot_table_size,
3188 	.get = param_get_uint,
3189 };
3190 
3191 #define param_check_slot_table_size(name, p) \
3192 	__param_check(name, p, unsigned int);
3193 
3194 static int param_set_max_slot_table_size(const char *val,
3195 				     const struct kernel_param *kp)
3196 {
3197 	return param_set_uint_minmax(val, kp,
3198 			RPC_MIN_SLOT_TABLE,
3199 			RPC_MAX_SLOT_TABLE_LIMIT);
3200 }
3201 
3202 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3203 	.set = param_set_max_slot_table_size,
3204 	.get = param_get_uint,
3205 };
3206 
3207 #define param_check_max_slot_table_size(name, p) \
3208 	__param_check(name, p, unsigned int);
3209 
3210 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3211 		   slot_table_size, 0644);
3212 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3213 		   max_slot_table_size, 0644);
3214 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3215 		   slot_table_size, 0644);
3216