xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 0ffe86f4)
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 "sunrpc.h"
58 
59 static void xs_close(struct rpc_xprt *xprt);
60 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
61 		struct socket *sock);
62 
63 /*
64  * xprtsock tunables
65  */
66 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
67 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
68 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
69 
70 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
71 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
72 
73 #define XS_TCP_LINGER_TO	(15U * HZ)
74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
75 
76 /*
77  * We can register our own files under /proc/sys/sunrpc by
78  * calling register_sysctl_table() again.  The files in that
79  * directory become the union of all files registered there.
80  *
81  * We simply need to make sure that we don't collide with
82  * someone else's file names!
83  */
84 
85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
90 
91 static struct ctl_table_header *sunrpc_table_header;
92 
93 /*
94  * FIXME: changing the UDP slot table size should also resize the UDP
95  *        socket buffers for existing UDP transports
96  */
97 static struct ctl_table xs_tunables_table[] = {
98 	{
99 		.procname	= "udp_slot_table_entries",
100 		.data		= &xprt_udp_slot_table_entries,
101 		.maxlen		= sizeof(unsigned int),
102 		.mode		= 0644,
103 		.proc_handler	= proc_dointvec_minmax,
104 		.extra1		= &min_slot_table_size,
105 		.extra2		= &max_slot_table_size
106 	},
107 	{
108 		.procname	= "tcp_slot_table_entries",
109 		.data		= &xprt_tcp_slot_table_entries,
110 		.maxlen		= sizeof(unsigned int),
111 		.mode		= 0644,
112 		.proc_handler	= proc_dointvec_minmax,
113 		.extra1		= &min_slot_table_size,
114 		.extra2		= &max_slot_table_size
115 	},
116 	{
117 		.procname	= "tcp_max_slot_table_entries",
118 		.data		= &xprt_max_tcp_slot_table_entries,
119 		.maxlen		= sizeof(unsigned int),
120 		.mode		= 0644,
121 		.proc_handler	= proc_dointvec_minmax,
122 		.extra1		= &min_slot_table_size,
123 		.extra2		= &max_tcp_slot_table_limit
124 	},
125 	{
126 		.procname	= "min_resvport",
127 		.data		= &xprt_min_resvport,
128 		.maxlen		= sizeof(unsigned int),
129 		.mode		= 0644,
130 		.proc_handler	= proc_dointvec_minmax,
131 		.extra1		= &xprt_min_resvport_limit,
132 		.extra2		= &xprt_max_resvport_limit
133 	},
134 	{
135 		.procname	= "max_resvport",
136 		.data		= &xprt_max_resvport,
137 		.maxlen		= sizeof(unsigned int),
138 		.mode		= 0644,
139 		.proc_handler	= proc_dointvec_minmax,
140 		.extra1		= &xprt_min_resvport_limit,
141 		.extra2		= &xprt_max_resvport_limit
142 	},
143 	{
144 		.procname	= "tcp_fin_timeout",
145 		.data		= &xs_tcp_fin_timeout,
146 		.maxlen		= sizeof(xs_tcp_fin_timeout),
147 		.mode		= 0644,
148 		.proc_handler	= proc_dointvec_jiffies,
149 	},
150 	{ },
151 };
152 
153 static struct ctl_table sunrpc_table[] = {
154 	{
155 		.procname	= "sunrpc",
156 		.mode		= 0555,
157 		.child		= xs_tunables_table
158 	},
159 	{ },
160 };
161 
162 /*
163  * Wait duration for a reply from the RPC portmapper.
164  */
165 #define XS_BIND_TO		(60U * HZ)
166 
167 /*
168  * Delay if a UDP socket connect error occurs.  This is most likely some
169  * kind of resource problem on the local host.
170  */
171 #define XS_UDP_REEST_TO		(2U * HZ)
172 
173 /*
174  * The reestablish timeout allows clients to delay for a bit before attempting
175  * to reconnect to a server that just dropped our connection.
176  *
177  * We implement an exponential backoff when trying to reestablish a TCP
178  * transport connection with the server.  Some servers like to drop a TCP
179  * connection when they are overworked, so we start with a short timeout and
180  * increase over time if the server is down or not responding.
181  */
182 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
183 
184 /*
185  * TCP idle timeout; client drops the transport socket if it is idle
186  * for this long.  Note that we also timeout UDP sockets to prevent
187  * holding port numbers when there is no RPC traffic.
188  */
189 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
190 
191 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
192 # undef  RPC_DEBUG_DATA
193 # define RPCDBG_FACILITY	RPCDBG_TRANS
194 #endif
195 
196 #ifdef RPC_DEBUG_DATA
197 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
198 {
199 	u8 *buf = (u8 *) packet;
200 	int j;
201 
202 	dprintk("RPC:       %s\n", msg);
203 	for (j = 0; j < count && j < 128; j += 4) {
204 		if (!(j & 31)) {
205 			if (j)
206 				dprintk("\n");
207 			dprintk("0x%04x ", j);
208 		}
209 		dprintk("%02x%02x%02x%02x ",
210 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
211 	}
212 	dprintk("\n");
213 }
214 #else
215 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
216 {
217 	/* NOP */
218 }
219 #endif
220 
221 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
222 {
223 	return (struct rpc_xprt *) sk->sk_user_data;
224 }
225 
226 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
227 {
228 	return (struct sockaddr *) &xprt->addr;
229 }
230 
231 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
232 {
233 	return (struct sockaddr_un *) &xprt->addr;
234 }
235 
236 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
237 {
238 	return (struct sockaddr_in *) &xprt->addr;
239 }
240 
241 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
242 {
243 	return (struct sockaddr_in6 *) &xprt->addr;
244 }
245 
246 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
247 {
248 	struct sockaddr *sap = xs_addr(xprt);
249 	struct sockaddr_in6 *sin6;
250 	struct sockaddr_in *sin;
251 	struct sockaddr_un *sun;
252 	char buf[128];
253 
254 	switch (sap->sa_family) {
255 	case AF_LOCAL:
256 		sun = xs_addr_un(xprt);
257 		strlcpy(buf, sun->sun_path, sizeof(buf));
258 		xprt->address_strings[RPC_DISPLAY_ADDR] =
259 						kstrdup(buf, GFP_KERNEL);
260 		break;
261 	case AF_INET:
262 		(void)rpc_ntop(sap, buf, sizeof(buf));
263 		xprt->address_strings[RPC_DISPLAY_ADDR] =
264 						kstrdup(buf, GFP_KERNEL);
265 		sin = xs_addr_in(xprt);
266 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
267 		break;
268 	case AF_INET6:
269 		(void)rpc_ntop(sap, buf, sizeof(buf));
270 		xprt->address_strings[RPC_DISPLAY_ADDR] =
271 						kstrdup(buf, GFP_KERNEL);
272 		sin6 = xs_addr_in6(xprt);
273 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
274 		break;
275 	default:
276 		BUG();
277 	}
278 
279 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
280 }
281 
282 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
283 {
284 	struct sockaddr *sap = xs_addr(xprt);
285 	char buf[128];
286 
287 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
288 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
289 
290 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
291 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
292 }
293 
294 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
295 				     const char *protocol,
296 				     const char *netid)
297 {
298 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
299 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
300 	xs_format_common_peer_addresses(xprt);
301 	xs_format_common_peer_ports(xprt);
302 }
303 
304 static void xs_update_peer_port(struct rpc_xprt *xprt)
305 {
306 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
307 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
308 
309 	xs_format_common_peer_ports(xprt);
310 }
311 
312 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
313 {
314 	unsigned int i;
315 
316 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
317 		switch (i) {
318 		case RPC_DISPLAY_PROTO:
319 		case RPC_DISPLAY_NETID:
320 			continue;
321 		default:
322 			kfree(xprt->address_strings[i]);
323 		}
324 }
325 
326 static size_t
327 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
328 {
329 	size_t i,n;
330 
331 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
332 		return want;
333 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
334 	for (i = 0; i < n; i++) {
335 		if (buf->pages[i])
336 			continue;
337 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
338 		if (!buf->pages[i]) {
339 			i *= PAGE_SIZE;
340 			return i > buf->page_base ? i - buf->page_base : 0;
341 		}
342 	}
343 	return want;
344 }
345 
346 static ssize_t
347 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
348 {
349 	ssize_t ret;
350 	if (seek != 0)
351 		iov_iter_advance(&msg->msg_iter, seek);
352 	ret = sock_recvmsg(sock, msg, flags);
353 	return ret > 0 ? ret + seek : ret;
354 }
355 
356 static ssize_t
357 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
358 		struct kvec *kvec, size_t count, size_t seek)
359 {
360 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
361 	return xs_sock_recvmsg(sock, msg, flags, seek);
362 }
363 
364 static ssize_t
365 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
366 		struct bio_vec *bvec, unsigned long nr, size_t count,
367 		size_t seek)
368 {
369 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
370 	return xs_sock_recvmsg(sock, msg, flags, seek);
371 }
372 
373 static ssize_t
374 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
375 		size_t count)
376 {
377 	iov_iter_discard(&msg->msg_iter, READ, count);
378 	return sock_recvmsg(sock, msg, flags);
379 }
380 
381 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
382 static void
383 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
384 {
385 	struct bvec_iter bi = {
386 		.bi_size = count,
387 	};
388 	struct bio_vec bv;
389 
390 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
391 	for_each_bvec(bv, bvec, bi, bi)
392 		flush_dcache_page(bv.bv_page);
393 }
394 #else
395 static inline void
396 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
397 {
398 }
399 #endif
400 
401 static ssize_t
402 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
403 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
404 {
405 	size_t want, seek_init = seek, offset = 0;
406 	ssize_t ret;
407 
408 	if (seek < buf->head[0].iov_len) {
409 		want = min_t(size_t, count, buf->head[0].iov_len);
410 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
411 		if (ret <= 0)
412 			goto sock_err;
413 		offset += ret;
414 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
415 			goto out;
416 		if (ret != want)
417 			goto out;
418 		seek = 0;
419 	} else {
420 		seek -= buf->head[0].iov_len;
421 		offset += buf->head[0].iov_len;
422 	}
423 
424 	want = xs_alloc_sparse_pages(buf,
425 			min_t(size_t, count - offset, buf->page_len),
426 			GFP_NOWAIT);
427 	if (seek < want) {
428 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
429 				xdr_buf_pagecount(buf),
430 				want + buf->page_base,
431 				seek + buf->page_base);
432 		if (ret <= 0)
433 			goto sock_err;
434 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
435 		offset += ret - buf->page_base;
436 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
437 			goto out;
438 		if (ret != want)
439 			goto out;
440 		seek = 0;
441 	} else {
442 		seek -= want;
443 		offset += want;
444 	}
445 
446 	if (seek < buf->tail[0].iov_len) {
447 		want = min_t(size_t, count - offset, buf->tail[0].iov_len);
448 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
449 		if (ret <= 0)
450 			goto sock_err;
451 		offset += ret;
452 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
453 			goto out;
454 		if (ret != want)
455 			goto out;
456 	} else
457 		offset += buf->tail[0].iov_len;
458 	ret = -EMSGSIZE;
459 out:
460 	*read = offset - seek_init;
461 	return ret;
462 sock_err:
463 	offset += seek;
464 	goto out;
465 }
466 
467 static void
468 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
469 {
470 	if (!transport->recv.copied) {
471 		if (buf->head[0].iov_len >= transport->recv.offset)
472 			memcpy(buf->head[0].iov_base,
473 					&transport->recv.xid,
474 					transport->recv.offset);
475 		transport->recv.copied = transport->recv.offset;
476 	}
477 }
478 
479 static bool
480 xs_read_stream_request_done(struct sock_xprt *transport)
481 {
482 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
483 }
484 
485 static ssize_t
486 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
487 		int flags, struct rpc_rqst *req)
488 {
489 	struct xdr_buf *buf = &req->rq_private_buf;
490 	size_t want, read;
491 	ssize_t ret;
492 
493 	xs_read_header(transport, buf);
494 
495 	want = transport->recv.len - transport->recv.offset;
496 	ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
497 			transport->recv.copied + want, transport->recv.copied,
498 			&read);
499 	transport->recv.offset += read;
500 	transport->recv.copied += read;
501 	if (transport->recv.offset == transport->recv.len) {
502 		if (xs_read_stream_request_done(transport))
503 			msg->msg_flags |= MSG_EOR;
504 		return read;
505 	}
506 
507 	switch (ret) {
508 	default:
509 		break;
510 	case -EFAULT:
511 	case -EMSGSIZE:
512 		msg->msg_flags |= MSG_TRUNC;
513 		return read;
514 	case 0:
515 		return -ESHUTDOWN;
516 	}
517 	return ret < 0 ? ret : read;
518 }
519 
520 static size_t
521 xs_read_stream_headersize(bool isfrag)
522 {
523 	if (isfrag)
524 		return sizeof(__be32);
525 	return 3 * sizeof(__be32);
526 }
527 
528 static ssize_t
529 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
530 		int flags, size_t want, size_t seek)
531 {
532 	struct kvec kvec = {
533 		.iov_base = &transport->recv.fraghdr,
534 		.iov_len = want,
535 	};
536 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
537 }
538 
539 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
540 static ssize_t
541 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
542 {
543 	struct rpc_xprt *xprt = &transport->xprt;
544 	struct rpc_rqst *req;
545 	ssize_t ret;
546 
547 	/* Look up and lock the request corresponding to the given XID */
548 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
549 	if (!req) {
550 		printk(KERN_WARNING "Callback slot table overflowed\n");
551 		return -ESHUTDOWN;
552 	}
553 
554 	ret = xs_read_stream_request(transport, msg, flags, req);
555 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
556 		xprt_complete_bc_request(req, transport->recv.copied);
557 
558 	return ret;
559 }
560 #else /* CONFIG_SUNRPC_BACKCHANNEL */
561 static ssize_t
562 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
563 {
564 	return -ESHUTDOWN;
565 }
566 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
567 
568 static ssize_t
569 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
570 {
571 	struct rpc_xprt *xprt = &transport->xprt;
572 	struct rpc_rqst *req;
573 	ssize_t ret = 0;
574 
575 	/* Look up and lock the request corresponding to the given XID */
576 	spin_lock(&xprt->queue_lock);
577 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
578 	if (!req) {
579 		msg->msg_flags |= MSG_TRUNC;
580 		goto out;
581 	}
582 	xprt_pin_rqst(req);
583 	spin_unlock(&xprt->queue_lock);
584 
585 	ret = xs_read_stream_request(transport, msg, flags, req);
586 
587 	spin_lock(&xprt->queue_lock);
588 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
589 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
590 	xprt_unpin_rqst(req);
591 out:
592 	spin_unlock(&xprt->queue_lock);
593 	return ret;
594 }
595 
596 static ssize_t
597 xs_read_stream(struct sock_xprt *transport, int flags)
598 {
599 	struct msghdr msg = { 0 };
600 	size_t want, read = 0;
601 	ssize_t ret = 0;
602 
603 	if (transport->recv.len == 0) {
604 		want = xs_read_stream_headersize(transport->recv.copied != 0);
605 		ret = xs_read_stream_header(transport, &msg, flags, want,
606 				transport->recv.offset);
607 		if (ret <= 0)
608 			goto out_err;
609 		transport->recv.offset = ret;
610 		if (transport->recv.offset != want)
611 			return transport->recv.offset;
612 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
613 			RPC_FRAGMENT_SIZE_MASK;
614 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
615 		read = ret;
616 	}
617 
618 	switch (be32_to_cpu(transport->recv.calldir)) {
619 	default:
620 		msg.msg_flags |= MSG_TRUNC;
621 		break;
622 	case RPC_CALL:
623 		ret = xs_read_stream_call(transport, &msg, flags);
624 		break;
625 	case RPC_REPLY:
626 		ret = xs_read_stream_reply(transport, &msg, flags);
627 	}
628 	if (msg.msg_flags & MSG_TRUNC) {
629 		transport->recv.calldir = cpu_to_be32(-1);
630 		transport->recv.copied = -1;
631 	}
632 	if (ret < 0)
633 		goto out_err;
634 	read += ret;
635 	if (transport->recv.offset < transport->recv.len) {
636 		if (!(msg.msg_flags & MSG_TRUNC))
637 			return read;
638 		msg.msg_flags = 0;
639 		ret = xs_read_discard(transport->sock, &msg, flags,
640 				transport->recv.len - transport->recv.offset);
641 		if (ret <= 0)
642 			goto out_err;
643 		transport->recv.offset += ret;
644 		read += ret;
645 		if (transport->recv.offset != transport->recv.len)
646 			return read;
647 	}
648 	if (xs_read_stream_request_done(transport)) {
649 		trace_xs_stream_read_request(transport);
650 		transport->recv.copied = 0;
651 	}
652 	transport->recv.offset = 0;
653 	transport->recv.len = 0;
654 	return read;
655 out_err:
656 	return ret != 0 ? ret : -ESHUTDOWN;
657 }
658 
659 static __poll_t xs_poll_socket(struct sock_xprt *transport)
660 {
661 	return transport->sock->ops->poll(NULL, transport->sock, NULL);
662 }
663 
664 static bool xs_poll_socket_readable(struct sock_xprt *transport)
665 {
666 	__poll_t events = xs_poll_socket(transport);
667 
668 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
669 }
670 
671 static void xs_poll_check_readable(struct sock_xprt *transport)
672 {
673 
674 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
675 	if (!xs_poll_socket_readable(transport))
676 		return;
677 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
678 		queue_work(xprtiod_workqueue, &transport->recv_worker);
679 }
680 
681 static void xs_stream_data_receive(struct sock_xprt *transport)
682 {
683 	size_t read = 0;
684 	ssize_t ret = 0;
685 
686 	mutex_lock(&transport->recv_mutex);
687 	if (transport->sock == NULL)
688 		goto out;
689 	for (;;) {
690 		ret = xs_read_stream(transport, MSG_DONTWAIT);
691 		if (ret < 0)
692 			break;
693 		read += ret;
694 		cond_resched();
695 	}
696 	xs_poll_check_readable(transport);
697 out:
698 	mutex_unlock(&transport->recv_mutex);
699 	trace_xs_stream_read_data(&transport->xprt, ret, read);
700 }
701 
702 static void xs_stream_data_receive_workfn(struct work_struct *work)
703 {
704 	struct sock_xprt *transport =
705 		container_of(work, struct sock_xprt, recv_worker);
706 	unsigned int pflags = memalloc_nofs_save();
707 
708 	xs_stream_data_receive(transport);
709 	memalloc_nofs_restore(pflags);
710 }
711 
712 static void
713 xs_stream_reset_connect(struct sock_xprt *transport)
714 {
715 	transport->recv.offset = 0;
716 	transport->recv.len = 0;
717 	transport->recv.copied = 0;
718 	transport->xmit.offset = 0;
719 	transport->xprt.stat.connect_count++;
720 	transport->xprt.stat.connect_start = jiffies;
721 }
722 
723 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
724 
725 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
726 {
727 	struct msghdr msg = {
728 		.msg_name	= addr,
729 		.msg_namelen	= addrlen,
730 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
731 	};
732 	struct kvec iov = {
733 		.iov_base	= vec->iov_base + base,
734 		.iov_len	= vec->iov_len - base,
735 	};
736 
737 	if (iov.iov_len != 0)
738 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
739 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
740 }
741 
742 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
743 {
744 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
745 			int offset, size_t size, int flags);
746 	struct page **ppage;
747 	unsigned int remainder;
748 	int err;
749 
750 	remainder = xdr->page_len - base;
751 	base += xdr->page_base;
752 	ppage = xdr->pages + (base >> PAGE_SHIFT);
753 	base &= ~PAGE_MASK;
754 	do_sendpage = sock->ops->sendpage;
755 	if (!zerocopy)
756 		do_sendpage = sock_no_sendpage;
757 	for(;;) {
758 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
759 		int flags = XS_SENDMSG_FLAGS;
760 
761 		remainder -= len;
762 		if (more)
763 			flags |= MSG_MORE;
764 		if (remainder != 0)
765 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
766 		err = do_sendpage(sock, *ppage, base, len, flags);
767 		if (remainder == 0 || err != len)
768 			break;
769 		*sent_p += err;
770 		ppage++;
771 		base = 0;
772 	}
773 	if (err > 0) {
774 		*sent_p += err;
775 		err = 0;
776 	}
777 	return err;
778 }
779 
780 /**
781  * xs_sendpages - write pages directly to a socket
782  * @sock: socket to send on
783  * @addr: UDP only -- address of destination
784  * @addrlen: UDP only -- length of destination address
785  * @xdr: buffer containing this request
786  * @base: starting position in the buffer
787  * @zerocopy: true if it is safe to use sendpage()
788  * @sent_p: return the total number of bytes successfully queued for sending
789  *
790  */
791 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
792 {
793 	unsigned int remainder = xdr->len - base;
794 	int err = 0;
795 	int sent = 0;
796 
797 	if (unlikely(!sock))
798 		return -ENOTSOCK;
799 
800 	if (base != 0) {
801 		addr = NULL;
802 		addrlen = 0;
803 	}
804 
805 	if (base < xdr->head[0].iov_len || addr != NULL) {
806 		unsigned int len = xdr->head[0].iov_len - base;
807 		remainder -= len;
808 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
809 		if (remainder == 0 || err != len)
810 			goto out;
811 		*sent_p += err;
812 		base = 0;
813 	} else
814 		base -= xdr->head[0].iov_len;
815 
816 	if (base < xdr->page_len) {
817 		unsigned int len = xdr->page_len - base;
818 		remainder -= len;
819 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
820 		*sent_p += sent;
821 		if (remainder == 0 || sent != len)
822 			goto out;
823 		base = 0;
824 	} else
825 		base -= xdr->page_len;
826 
827 	if (base >= xdr->tail[0].iov_len)
828 		return 0;
829 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
830 out:
831 	if (err > 0) {
832 		*sent_p += err;
833 		err = 0;
834 	}
835 	return err;
836 }
837 
838 /**
839  * xs_nospace - handle transmit was incomplete
840  * @req: pointer to RPC request
841  *
842  */
843 static int xs_nospace(struct rpc_rqst *req)
844 {
845 	struct rpc_xprt *xprt = req->rq_xprt;
846 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
847 	struct sock *sk = transport->inet;
848 	int ret = -EAGAIN;
849 
850 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
851 			req->rq_task->tk_pid,
852 			req->rq_slen - transport->xmit.offset,
853 			req->rq_slen);
854 
855 	/* Protect against races with write_space */
856 	spin_lock_bh(&xprt->transport_lock);
857 
858 	/* Don't race with disconnect */
859 	if (xprt_connected(xprt)) {
860 		/* wait for more buffer space */
861 		sk->sk_write_pending++;
862 		xprt_wait_for_buffer_space(xprt);
863 	} else
864 		ret = -ENOTCONN;
865 
866 	spin_unlock_bh(&xprt->transport_lock);
867 
868 	/* Race breaker in case memory is freed before above code is called */
869 	if (ret == -EAGAIN) {
870 		struct socket_wq *wq;
871 
872 		rcu_read_lock();
873 		wq = rcu_dereference(sk->sk_wq);
874 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
875 		rcu_read_unlock();
876 
877 		sk->sk_write_space(sk);
878 	}
879 	return ret;
880 }
881 
882 static void
883 xs_stream_prepare_request(struct rpc_rqst *req)
884 {
885 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_NOIO);
886 }
887 
888 /*
889  * Determine if the previous message in the stream was aborted before it
890  * could complete transmission.
891  */
892 static bool
893 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
894 {
895 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
896 }
897 
898 /*
899  * Construct a stream transport record marker in @buf.
900  */
901 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
902 {
903 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
904 	rpc_fraghdr *base = buf->head[0].iov_base;
905 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
906 }
907 
908 /**
909  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
910  * @req: pointer to RPC request
911  *
912  * Return values:
913  *        0:	The request has been sent
914  *   EAGAIN:	The socket was blocked, please call again later to
915  *		complete the request
916  * ENOTCONN:	Caller needs to invoke connect logic then call again
917  *    other:	Some other error occured, the request was not sent
918  */
919 static int xs_local_send_request(struct rpc_rqst *req)
920 {
921 	struct rpc_xprt *xprt = req->rq_xprt;
922 	struct sock_xprt *transport =
923 				container_of(xprt, struct sock_xprt, xprt);
924 	struct xdr_buf *xdr = &req->rq_snd_buf;
925 	int status;
926 	int sent = 0;
927 
928 	/* Close the stream if the previous transmission was incomplete */
929 	if (xs_send_request_was_aborted(transport, req)) {
930 		xs_close(xprt);
931 		return -ENOTCONN;
932 	}
933 
934 	xs_encode_stream_record_marker(&req->rq_snd_buf);
935 
936 	xs_pktdump("packet data:",
937 			req->rq_svec->iov_base, req->rq_svec->iov_len);
938 
939 	req->rq_xtime = ktime_get();
940 	status = xs_sendpages(transport->sock, NULL, 0, xdr,
941 			      transport->xmit.offset,
942 			      true, &sent);
943 	dprintk("RPC:       %s(%u) = %d\n",
944 			__func__, xdr->len - transport->xmit.offset, status);
945 
946 	if (status == -EAGAIN && sock_writeable(transport->inet))
947 		status = -ENOBUFS;
948 
949 	if (likely(sent > 0) || status == 0) {
950 		transport->xmit.offset += sent;
951 		req->rq_bytes_sent = transport->xmit.offset;
952 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
953 			req->rq_xmit_bytes_sent += transport->xmit.offset;
954 			req->rq_bytes_sent = 0;
955 			transport->xmit.offset = 0;
956 			return 0;
957 		}
958 		status = -EAGAIN;
959 	}
960 
961 	switch (status) {
962 	case -ENOBUFS:
963 		break;
964 	case -EAGAIN:
965 		status = xs_nospace(req);
966 		break;
967 	default:
968 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
969 			-status);
970 		/* fall through */
971 	case -EPIPE:
972 		xs_close(xprt);
973 		status = -ENOTCONN;
974 	}
975 
976 	return status;
977 }
978 
979 /**
980  * xs_udp_send_request - write an RPC request to a UDP socket
981  * @req: pointer to RPC request
982  *
983  * Return values:
984  *        0:	The request has been sent
985  *   EAGAIN:	The socket was blocked, please call again later to
986  *		complete the request
987  * ENOTCONN:	Caller needs to invoke connect logic then call again
988  *    other:	Some other error occurred, the request was not sent
989  */
990 static int xs_udp_send_request(struct rpc_rqst *req)
991 {
992 	struct rpc_xprt *xprt = req->rq_xprt;
993 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
994 	struct xdr_buf *xdr = &req->rq_snd_buf;
995 	int sent = 0;
996 	int status;
997 
998 	xs_pktdump("packet data:",
999 				req->rq_svec->iov_base,
1000 				req->rq_svec->iov_len);
1001 
1002 	if (!xprt_bound(xprt))
1003 		return -ENOTCONN;
1004 
1005 	if (!xprt_request_get_cong(xprt, req))
1006 		return -EBADSLT;
1007 
1008 	req->rq_xtime = ktime_get();
1009 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
1010 			      xdr, 0, true, &sent);
1011 
1012 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
1013 			xdr->len, status);
1014 
1015 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
1016 	if (status == -EPERM)
1017 		goto process_status;
1018 
1019 	if (status == -EAGAIN && sock_writeable(transport->inet))
1020 		status = -ENOBUFS;
1021 
1022 	if (sent > 0 || status == 0) {
1023 		req->rq_xmit_bytes_sent += sent;
1024 		if (sent >= req->rq_slen)
1025 			return 0;
1026 		/* Still some bytes left; set up for a retry later. */
1027 		status = -EAGAIN;
1028 	}
1029 
1030 process_status:
1031 	switch (status) {
1032 	case -ENOTSOCK:
1033 		status = -ENOTCONN;
1034 		/* Should we call xs_close() here? */
1035 		break;
1036 	case -EAGAIN:
1037 		status = xs_nospace(req);
1038 		break;
1039 	case -ENETUNREACH:
1040 	case -ENOBUFS:
1041 	case -EPIPE:
1042 	case -ECONNREFUSED:
1043 	case -EPERM:
1044 		/* When the server has died, an ICMP port unreachable message
1045 		 * prompts ECONNREFUSED. */
1046 		break;
1047 	default:
1048 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1049 			-status);
1050 	}
1051 
1052 	return status;
1053 }
1054 
1055 /**
1056  * xs_tcp_send_request - write an RPC request to a TCP socket
1057  * @req: pointer to RPC request
1058  *
1059  * Return values:
1060  *        0:	The request has been sent
1061  *   EAGAIN:	The socket was blocked, please call again later to
1062  *		complete the request
1063  * ENOTCONN:	Caller needs to invoke connect logic then call again
1064  *    other:	Some other error occurred, the request was not sent
1065  *
1066  * XXX: In the case of soft timeouts, should we eventually give up
1067  *	if sendmsg is not able to make progress?
1068  */
1069 static int xs_tcp_send_request(struct rpc_rqst *req)
1070 {
1071 	struct rpc_xprt *xprt = req->rq_xprt;
1072 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1073 	struct xdr_buf *xdr = &req->rq_snd_buf;
1074 	bool zerocopy = true;
1075 	bool vm_wait = false;
1076 	int status;
1077 	int sent;
1078 
1079 	/* Close the stream if the previous transmission was incomplete */
1080 	if (xs_send_request_was_aborted(transport, req)) {
1081 		if (transport->sock != NULL)
1082 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1083 		return -ENOTCONN;
1084 	}
1085 
1086 	xs_encode_stream_record_marker(&req->rq_snd_buf);
1087 
1088 	xs_pktdump("packet data:",
1089 				req->rq_svec->iov_base,
1090 				req->rq_svec->iov_len);
1091 	/* Don't use zero copy if this is a resend. If the RPC call
1092 	 * completes while the socket holds a reference to the pages,
1093 	 * then we may end up resending corrupted data.
1094 	 */
1095 	if (req->rq_task->tk_flags & RPC_TASK_SENT)
1096 		zerocopy = false;
1097 
1098 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1099 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1100 
1101 	/* Continue transmitting the packet/record. We must be careful
1102 	 * to cope with writespace callbacks arriving _after_ we have
1103 	 * called sendmsg(). */
1104 	req->rq_xtime = ktime_get();
1105 	while (1) {
1106 		sent = 0;
1107 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
1108 				      transport->xmit.offset,
1109 				      zerocopy, &sent);
1110 
1111 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1112 				xdr->len - transport->xmit.offset, status);
1113 
1114 		/* If we've sent the entire packet, immediately
1115 		 * reset the count of bytes sent. */
1116 		transport->xmit.offset += sent;
1117 		req->rq_bytes_sent = transport->xmit.offset;
1118 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
1119 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1120 			req->rq_bytes_sent = 0;
1121 			transport->xmit.offset = 0;
1122 			return 0;
1123 		}
1124 
1125 		WARN_ON_ONCE(sent == 0 && status == 0);
1126 
1127 		if (status == -EAGAIN ) {
1128 			/*
1129 			 * Return EAGAIN if we're sure we're hitting the
1130 			 * socket send buffer limits.
1131 			 */
1132 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1133 				break;
1134 			/*
1135 			 * Did we hit a memory allocation failure?
1136 			 */
1137 			if (sent == 0) {
1138 				status = -ENOBUFS;
1139 				if (vm_wait)
1140 					break;
1141 				/* Retry, knowing now that we're below the
1142 				 * socket send buffer limit
1143 				 */
1144 				vm_wait = true;
1145 			}
1146 			continue;
1147 		}
1148 		if (status < 0)
1149 			break;
1150 		vm_wait = false;
1151 	}
1152 
1153 	switch (status) {
1154 	case -ENOTSOCK:
1155 		status = -ENOTCONN;
1156 		/* Should we call xs_close() here? */
1157 		break;
1158 	case -EAGAIN:
1159 		status = xs_nospace(req);
1160 		break;
1161 	case -ECONNRESET:
1162 	case -ECONNREFUSED:
1163 	case -ENOTCONN:
1164 	case -EADDRINUSE:
1165 	case -ENOBUFS:
1166 	case -EPIPE:
1167 		break;
1168 	default:
1169 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1170 			-status);
1171 	}
1172 
1173 	return status;
1174 }
1175 
1176 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1177 {
1178 	transport->old_data_ready = sk->sk_data_ready;
1179 	transport->old_state_change = sk->sk_state_change;
1180 	transport->old_write_space = sk->sk_write_space;
1181 	transport->old_error_report = sk->sk_error_report;
1182 }
1183 
1184 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1185 {
1186 	sk->sk_data_ready = transport->old_data_ready;
1187 	sk->sk_state_change = transport->old_state_change;
1188 	sk->sk_write_space = transport->old_write_space;
1189 	sk->sk_error_report = transport->old_error_report;
1190 }
1191 
1192 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1193 {
1194 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1195 
1196 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1197 }
1198 
1199 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1200 {
1201 	smp_mb__before_atomic();
1202 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1203 	clear_bit(XPRT_CLOSING, &xprt->state);
1204 	xs_sock_reset_state_flags(xprt);
1205 	smp_mb__after_atomic();
1206 }
1207 
1208 /**
1209  * xs_error_report - callback to handle TCP socket state errors
1210  * @sk: socket
1211  *
1212  * Note: we don't call sock_error() since there may be a rpc_task
1213  * using the socket, and so we don't want to clear sk->sk_err.
1214  */
1215 static void xs_error_report(struct sock *sk)
1216 {
1217 	struct rpc_xprt *xprt;
1218 	int err;
1219 
1220 	read_lock_bh(&sk->sk_callback_lock);
1221 	if (!(xprt = xprt_from_sock(sk)))
1222 		goto out;
1223 
1224 	err = -sk->sk_err;
1225 	if (err == 0)
1226 		goto out;
1227 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1228 			xprt, -err);
1229 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
1230 	xprt_wake_pending_tasks(xprt, err);
1231  out:
1232 	read_unlock_bh(&sk->sk_callback_lock);
1233 }
1234 
1235 static void xs_reset_transport(struct sock_xprt *transport)
1236 {
1237 	struct socket *sock = transport->sock;
1238 	struct sock *sk = transport->inet;
1239 	struct rpc_xprt *xprt = &transport->xprt;
1240 
1241 	if (sk == NULL)
1242 		return;
1243 
1244 	if (atomic_read(&transport->xprt.swapper))
1245 		sk_clear_memalloc(sk);
1246 
1247 	kernel_sock_shutdown(sock, SHUT_RDWR);
1248 
1249 	mutex_lock(&transport->recv_mutex);
1250 	write_lock_bh(&sk->sk_callback_lock);
1251 	transport->inet = NULL;
1252 	transport->sock = NULL;
1253 
1254 	sk->sk_user_data = NULL;
1255 
1256 	xs_restore_old_callbacks(transport, sk);
1257 	xprt_clear_connected(xprt);
1258 	write_unlock_bh(&sk->sk_callback_lock);
1259 	xs_sock_reset_connection_flags(xprt);
1260 	mutex_unlock(&transport->recv_mutex);
1261 
1262 	trace_rpc_socket_close(xprt, sock);
1263 	sock_release(sock);
1264 
1265 	xprt_disconnect_done(xprt);
1266 }
1267 
1268 /**
1269  * xs_close - close a socket
1270  * @xprt: transport
1271  *
1272  * This is used when all requests are complete; ie, no DRC state remains
1273  * on the server we want to save.
1274  *
1275  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1276  * xs_reset_transport() zeroing the socket from underneath a writer.
1277  */
1278 static void xs_close(struct rpc_xprt *xprt)
1279 {
1280 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1281 
1282 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1283 
1284 	xs_reset_transport(transport);
1285 	xprt->reestablish_timeout = 0;
1286 }
1287 
1288 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1289 {
1290 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1291 		xprt);
1292 	xprt_disconnect_done(xprt);
1293 }
1294 
1295 static void xs_xprt_free(struct rpc_xprt *xprt)
1296 {
1297 	xs_free_peer_addresses(xprt);
1298 	xprt_free(xprt);
1299 }
1300 
1301 /**
1302  * xs_destroy - prepare to shutdown a transport
1303  * @xprt: doomed transport
1304  *
1305  */
1306 static void xs_destroy(struct rpc_xprt *xprt)
1307 {
1308 	struct sock_xprt *transport = container_of(xprt,
1309 			struct sock_xprt, xprt);
1310 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1311 
1312 	cancel_delayed_work_sync(&transport->connect_worker);
1313 	xs_close(xprt);
1314 	cancel_work_sync(&transport->recv_worker);
1315 	xs_xprt_free(xprt);
1316 	module_put(THIS_MODULE);
1317 }
1318 
1319 /**
1320  * xs_udp_data_read_skb - receive callback for UDP sockets
1321  * @xprt: transport
1322  * @sk: socket
1323  * @skb: skbuff
1324  *
1325  */
1326 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1327 		struct sock *sk,
1328 		struct sk_buff *skb)
1329 {
1330 	struct rpc_task *task;
1331 	struct rpc_rqst *rovr;
1332 	int repsize, copied;
1333 	u32 _xid;
1334 	__be32 *xp;
1335 
1336 	repsize = skb->len;
1337 	if (repsize < 4) {
1338 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1339 		return;
1340 	}
1341 
1342 	/* Copy the XID from the skb... */
1343 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1344 	if (xp == NULL)
1345 		return;
1346 
1347 	/* Look up and lock the request corresponding to the given XID */
1348 	spin_lock(&xprt->queue_lock);
1349 	rovr = xprt_lookup_rqst(xprt, *xp);
1350 	if (!rovr)
1351 		goto out_unlock;
1352 	xprt_pin_rqst(rovr);
1353 	xprt_update_rtt(rovr->rq_task);
1354 	spin_unlock(&xprt->queue_lock);
1355 	task = rovr->rq_task;
1356 
1357 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1358 		copied = repsize;
1359 
1360 	/* Suck it into the iovec, verify checksum if not done by hw. */
1361 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1362 		spin_lock(&xprt->queue_lock);
1363 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1364 		goto out_unpin;
1365 	}
1366 
1367 
1368 	spin_lock_bh(&xprt->transport_lock);
1369 	xprt_adjust_cwnd(xprt, task, copied);
1370 	spin_unlock_bh(&xprt->transport_lock);
1371 	spin_lock(&xprt->queue_lock);
1372 	xprt_complete_rqst(task, copied);
1373 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1374 out_unpin:
1375 	xprt_unpin_rqst(rovr);
1376  out_unlock:
1377 	spin_unlock(&xprt->queue_lock);
1378 }
1379 
1380 static void xs_udp_data_receive(struct sock_xprt *transport)
1381 {
1382 	struct sk_buff *skb;
1383 	struct sock *sk;
1384 	int err;
1385 
1386 	mutex_lock(&transport->recv_mutex);
1387 	sk = transport->inet;
1388 	if (sk == NULL)
1389 		goto out;
1390 	for (;;) {
1391 		skb = skb_recv_udp(sk, 0, 1, &err);
1392 		if (skb == NULL)
1393 			break;
1394 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1395 		consume_skb(skb);
1396 		cond_resched();
1397 	}
1398 	xs_poll_check_readable(transport);
1399 out:
1400 	mutex_unlock(&transport->recv_mutex);
1401 }
1402 
1403 static void xs_udp_data_receive_workfn(struct work_struct *work)
1404 {
1405 	struct sock_xprt *transport =
1406 		container_of(work, struct sock_xprt, recv_worker);
1407 	unsigned int pflags = memalloc_nofs_save();
1408 
1409 	xs_udp_data_receive(transport);
1410 	memalloc_nofs_restore(pflags);
1411 }
1412 
1413 /**
1414  * xs_data_ready - "data ready" callback for UDP sockets
1415  * @sk: socket with data to read
1416  *
1417  */
1418 static void xs_data_ready(struct sock *sk)
1419 {
1420 	struct rpc_xprt *xprt;
1421 
1422 	read_lock_bh(&sk->sk_callback_lock);
1423 	dprintk("RPC:       xs_data_ready...\n");
1424 	xprt = xprt_from_sock(sk);
1425 	if (xprt != NULL) {
1426 		struct sock_xprt *transport = container_of(xprt,
1427 				struct sock_xprt, xprt);
1428 		transport->old_data_ready(sk);
1429 		/* Any data means we had a useful conversation, so
1430 		 * then we don't need to delay the next reconnect
1431 		 */
1432 		if (xprt->reestablish_timeout)
1433 			xprt->reestablish_timeout = 0;
1434 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1435 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1436 	}
1437 	read_unlock_bh(&sk->sk_callback_lock);
1438 }
1439 
1440 /*
1441  * Helper function to force a TCP close if the server is sending
1442  * junk and/or it has put us in CLOSE_WAIT
1443  */
1444 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1445 {
1446 	xprt_force_disconnect(xprt);
1447 }
1448 
1449 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1450 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1451 {
1452 	return PAGE_SIZE;
1453 }
1454 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1455 
1456 /**
1457  * xs_tcp_state_change - callback to handle TCP socket state changes
1458  * @sk: socket whose state has changed
1459  *
1460  */
1461 static void xs_tcp_state_change(struct sock *sk)
1462 {
1463 	struct rpc_xprt *xprt;
1464 	struct sock_xprt *transport;
1465 
1466 	read_lock_bh(&sk->sk_callback_lock);
1467 	if (!(xprt = xprt_from_sock(sk)))
1468 		goto out;
1469 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1470 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1471 			sk->sk_state, xprt_connected(xprt),
1472 			sock_flag(sk, SOCK_DEAD),
1473 			sock_flag(sk, SOCK_ZAPPED),
1474 			sk->sk_shutdown);
1475 
1476 	transport = container_of(xprt, struct sock_xprt, xprt);
1477 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1478 	switch (sk->sk_state) {
1479 	case TCP_ESTABLISHED:
1480 		spin_lock(&xprt->transport_lock);
1481 		if (!xprt_test_and_set_connected(xprt)) {
1482 			xprt->connect_cookie++;
1483 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1484 			xprt_clear_connecting(xprt);
1485 
1486 			xprt->stat.connect_count++;
1487 			xprt->stat.connect_time += (long)jiffies -
1488 						   xprt->stat.connect_start;
1489 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1490 		}
1491 		spin_unlock(&xprt->transport_lock);
1492 		break;
1493 	case TCP_FIN_WAIT1:
1494 		/* The client initiated a shutdown of the socket */
1495 		xprt->connect_cookie++;
1496 		xprt->reestablish_timeout = 0;
1497 		set_bit(XPRT_CLOSING, &xprt->state);
1498 		smp_mb__before_atomic();
1499 		clear_bit(XPRT_CONNECTED, &xprt->state);
1500 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1501 		smp_mb__after_atomic();
1502 		break;
1503 	case TCP_CLOSE_WAIT:
1504 		/* The server initiated a shutdown of the socket */
1505 		xprt->connect_cookie++;
1506 		clear_bit(XPRT_CONNECTED, &xprt->state);
1507 		xs_tcp_force_close(xprt);
1508 		/* fall through */
1509 	case TCP_CLOSING:
1510 		/*
1511 		 * If the server closed down the connection, make sure that
1512 		 * we back off before reconnecting
1513 		 */
1514 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1515 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1516 		break;
1517 	case TCP_LAST_ACK:
1518 		set_bit(XPRT_CLOSING, &xprt->state);
1519 		smp_mb__before_atomic();
1520 		clear_bit(XPRT_CONNECTED, &xprt->state);
1521 		smp_mb__after_atomic();
1522 		break;
1523 	case TCP_CLOSE:
1524 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1525 					&transport->sock_state))
1526 			xprt_clear_connecting(xprt);
1527 		clear_bit(XPRT_CLOSING, &xprt->state);
1528 		/* Trigger the socket release */
1529 		xs_tcp_force_close(xprt);
1530 	}
1531  out:
1532 	read_unlock_bh(&sk->sk_callback_lock);
1533 }
1534 
1535 static void xs_write_space(struct sock *sk)
1536 {
1537 	struct socket_wq *wq;
1538 	struct rpc_xprt *xprt;
1539 
1540 	if (!sk->sk_socket)
1541 		return;
1542 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1543 
1544 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1545 		return;
1546 	rcu_read_lock();
1547 	wq = rcu_dereference(sk->sk_wq);
1548 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1549 		goto out;
1550 
1551 	if (xprt_write_space(xprt))
1552 		sk->sk_write_pending--;
1553 out:
1554 	rcu_read_unlock();
1555 }
1556 
1557 /**
1558  * xs_udp_write_space - callback invoked when socket buffer space
1559  *                             becomes available
1560  * @sk: socket whose state has changed
1561  *
1562  * Called when more output buffer space is available for this socket.
1563  * We try not to wake our writers until they can make "significant"
1564  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1565  * with a bunch of small requests.
1566  */
1567 static void xs_udp_write_space(struct sock *sk)
1568 {
1569 	read_lock_bh(&sk->sk_callback_lock);
1570 
1571 	/* from net/core/sock.c:sock_def_write_space */
1572 	if (sock_writeable(sk))
1573 		xs_write_space(sk);
1574 
1575 	read_unlock_bh(&sk->sk_callback_lock);
1576 }
1577 
1578 /**
1579  * xs_tcp_write_space - callback invoked when socket buffer space
1580  *                             becomes available
1581  * @sk: socket whose state has changed
1582  *
1583  * Called when more output buffer space is available for this socket.
1584  * We try not to wake our writers until they can make "significant"
1585  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1586  * with a bunch of small requests.
1587  */
1588 static void xs_tcp_write_space(struct sock *sk)
1589 {
1590 	read_lock_bh(&sk->sk_callback_lock);
1591 
1592 	/* from net/core/stream.c:sk_stream_write_space */
1593 	if (sk_stream_is_writeable(sk))
1594 		xs_write_space(sk);
1595 
1596 	read_unlock_bh(&sk->sk_callback_lock);
1597 }
1598 
1599 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1600 {
1601 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1602 	struct sock *sk = transport->inet;
1603 
1604 	if (transport->rcvsize) {
1605 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1606 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1607 	}
1608 	if (transport->sndsize) {
1609 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1610 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1611 		sk->sk_write_space(sk);
1612 	}
1613 }
1614 
1615 /**
1616  * xs_udp_set_buffer_size - set send and receive limits
1617  * @xprt: generic transport
1618  * @sndsize: requested size of send buffer, in bytes
1619  * @rcvsize: requested size of receive buffer, in bytes
1620  *
1621  * Set socket send and receive buffer size limits.
1622  */
1623 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1624 {
1625 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1626 
1627 	transport->sndsize = 0;
1628 	if (sndsize)
1629 		transport->sndsize = sndsize + 1024;
1630 	transport->rcvsize = 0;
1631 	if (rcvsize)
1632 		transport->rcvsize = rcvsize + 1024;
1633 
1634 	xs_udp_do_set_buffer_size(xprt);
1635 }
1636 
1637 /**
1638  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1639  * @xprt: controlling transport
1640  * @task: task that timed out
1641  *
1642  * Adjust the congestion window after a retransmit timeout has occurred.
1643  */
1644 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1645 {
1646 	spin_lock_bh(&xprt->transport_lock);
1647 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1648 	spin_unlock_bh(&xprt->transport_lock);
1649 }
1650 
1651 static int xs_get_random_port(void)
1652 {
1653 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1654 	unsigned short range;
1655 	unsigned short rand;
1656 
1657 	if (max < min)
1658 		return -EADDRINUSE;
1659 	range = max - min + 1;
1660 	rand = (unsigned short) prandom_u32() % range;
1661 	return rand + min;
1662 }
1663 
1664 /**
1665  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1666  * @sock: socket
1667  *
1668  * Note that this function has to be called on all sockets that share the
1669  * same port, and it must be called before binding.
1670  */
1671 static void xs_sock_set_reuseport(struct socket *sock)
1672 {
1673 	int opt = 1;
1674 
1675 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1676 			(char *)&opt, sizeof(opt));
1677 }
1678 
1679 static unsigned short xs_sock_getport(struct socket *sock)
1680 {
1681 	struct sockaddr_storage buf;
1682 	unsigned short port = 0;
1683 
1684 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1685 		goto out;
1686 	switch (buf.ss_family) {
1687 	case AF_INET6:
1688 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1689 		break;
1690 	case AF_INET:
1691 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1692 	}
1693 out:
1694 	return port;
1695 }
1696 
1697 /**
1698  * xs_set_port - reset the port number in the remote endpoint address
1699  * @xprt: generic transport
1700  * @port: new port number
1701  *
1702  */
1703 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1704 {
1705 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1706 
1707 	rpc_set_port(xs_addr(xprt), port);
1708 	xs_update_peer_port(xprt);
1709 }
1710 
1711 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1712 {
1713 	if (transport->srcport == 0)
1714 		transport->srcport = xs_sock_getport(sock);
1715 }
1716 
1717 static int xs_get_srcport(struct sock_xprt *transport)
1718 {
1719 	int port = transport->srcport;
1720 
1721 	if (port == 0 && transport->xprt.resvport)
1722 		port = xs_get_random_port();
1723 	return port;
1724 }
1725 
1726 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1727 {
1728 	if (transport->srcport != 0)
1729 		transport->srcport = 0;
1730 	if (!transport->xprt.resvport)
1731 		return 0;
1732 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1733 		return xprt_max_resvport;
1734 	return --port;
1735 }
1736 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1737 {
1738 	struct sockaddr_storage myaddr;
1739 	int err, nloop = 0;
1740 	int port = xs_get_srcport(transport);
1741 	unsigned short last;
1742 
1743 	/*
1744 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1745 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1746 	 * port selection happen implicitly when the socket is used
1747 	 * (for example at connect time).
1748 	 *
1749 	 * This ensures that we can continue to establish TCP
1750 	 * connections even when all local ephemeral ports are already
1751 	 * a part of some TCP connection.  This makes no difference
1752 	 * for UDP sockets, but also doens't harm them.
1753 	 *
1754 	 * If we're asking for any reserved port (i.e. port == 0 &&
1755 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1756 	 * ensure that port is non-zero and we will bind as needed.
1757 	 */
1758 	if (port <= 0)
1759 		return port;
1760 
1761 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1762 	do {
1763 		rpc_set_port((struct sockaddr *)&myaddr, port);
1764 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1765 				transport->xprt.addrlen);
1766 		if (err == 0) {
1767 			transport->srcport = port;
1768 			break;
1769 		}
1770 		last = port;
1771 		port = xs_next_srcport(transport, port);
1772 		if (port > last)
1773 			nloop++;
1774 	} while (err == -EADDRINUSE && nloop != 2);
1775 
1776 	if (myaddr.ss_family == AF_INET)
1777 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1778 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1779 				port, err ? "failed" : "ok", err);
1780 	else
1781 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1782 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1783 				port, err ? "failed" : "ok", err);
1784 	return err;
1785 }
1786 
1787 /*
1788  * We don't support autobind on AF_LOCAL sockets
1789  */
1790 static void xs_local_rpcbind(struct rpc_task *task)
1791 {
1792 	xprt_set_bound(task->tk_xprt);
1793 }
1794 
1795 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1796 {
1797 }
1798 
1799 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1800 static struct lock_class_key xs_key[2];
1801 static struct lock_class_key xs_slock_key[2];
1802 
1803 static inline void xs_reclassify_socketu(struct socket *sock)
1804 {
1805 	struct sock *sk = sock->sk;
1806 
1807 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1808 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1809 }
1810 
1811 static inline void xs_reclassify_socket4(struct socket *sock)
1812 {
1813 	struct sock *sk = sock->sk;
1814 
1815 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1816 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1817 }
1818 
1819 static inline void xs_reclassify_socket6(struct socket *sock)
1820 {
1821 	struct sock *sk = sock->sk;
1822 
1823 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1824 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1825 }
1826 
1827 static inline void xs_reclassify_socket(int family, struct socket *sock)
1828 {
1829 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1830 		return;
1831 
1832 	switch (family) {
1833 	case AF_LOCAL:
1834 		xs_reclassify_socketu(sock);
1835 		break;
1836 	case AF_INET:
1837 		xs_reclassify_socket4(sock);
1838 		break;
1839 	case AF_INET6:
1840 		xs_reclassify_socket6(sock);
1841 		break;
1842 	}
1843 }
1844 #else
1845 static inline void xs_reclassify_socket(int family, struct socket *sock)
1846 {
1847 }
1848 #endif
1849 
1850 static void xs_dummy_setup_socket(struct work_struct *work)
1851 {
1852 }
1853 
1854 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1855 		struct sock_xprt *transport, int family, int type,
1856 		int protocol, bool reuseport)
1857 {
1858 	struct socket *sock;
1859 	int err;
1860 
1861 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1862 	if (err < 0) {
1863 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1864 				protocol, -err);
1865 		goto out;
1866 	}
1867 	xs_reclassify_socket(family, sock);
1868 
1869 	if (reuseport)
1870 		xs_sock_set_reuseport(sock);
1871 
1872 	err = xs_bind(transport, sock);
1873 	if (err) {
1874 		sock_release(sock);
1875 		goto out;
1876 	}
1877 
1878 	return sock;
1879 out:
1880 	return ERR_PTR(err);
1881 }
1882 
1883 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1884 				      struct socket *sock)
1885 {
1886 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1887 									xprt);
1888 
1889 	if (!transport->inet) {
1890 		struct sock *sk = sock->sk;
1891 
1892 		write_lock_bh(&sk->sk_callback_lock);
1893 
1894 		xs_save_old_callbacks(transport, sk);
1895 
1896 		sk->sk_user_data = xprt;
1897 		sk->sk_data_ready = xs_data_ready;
1898 		sk->sk_write_space = xs_udp_write_space;
1899 		sock_set_flag(sk, SOCK_FASYNC);
1900 		sk->sk_error_report = xs_error_report;
1901 
1902 		xprt_clear_connected(xprt);
1903 
1904 		/* Reset to new socket */
1905 		transport->sock = sock;
1906 		transport->inet = sk;
1907 
1908 		write_unlock_bh(&sk->sk_callback_lock);
1909 	}
1910 
1911 	xs_stream_reset_connect(transport);
1912 
1913 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1914 }
1915 
1916 /**
1917  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1918  * @transport: socket transport to connect
1919  */
1920 static int xs_local_setup_socket(struct sock_xprt *transport)
1921 {
1922 	struct rpc_xprt *xprt = &transport->xprt;
1923 	struct socket *sock;
1924 	int status = -EIO;
1925 
1926 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1927 					SOCK_STREAM, 0, &sock, 1);
1928 	if (status < 0) {
1929 		dprintk("RPC:       can't create AF_LOCAL "
1930 			"transport socket (%d).\n", -status);
1931 		goto out;
1932 	}
1933 	xs_reclassify_socket(AF_LOCAL, sock);
1934 
1935 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1936 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1937 
1938 	status = xs_local_finish_connecting(xprt, sock);
1939 	trace_rpc_socket_connect(xprt, sock, status);
1940 	switch (status) {
1941 	case 0:
1942 		dprintk("RPC:       xprt %p connected to %s\n",
1943 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1944 		xprt->stat.connect_count++;
1945 		xprt->stat.connect_time += (long)jiffies -
1946 					   xprt->stat.connect_start;
1947 		xprt_set_connected(xprt);
1948 	case -ENOBUFS:
1949 		break;
1950 	case -ENOENT:
1951 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1952 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1953 		break;
1954 	case -ECONNREFUSED:
1955 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1956 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1957 		break;
1958 	default:
1959 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1960 				__func__, -status,
1961 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1962 	}
1963 
1964 out:
1965 	xprt_clear_connecting(xprt);
1966 	xprt_wake_pending_tasks(xprt, status);
1967 	return status;
1968 }
1969 
1970 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1971 {
1972 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1973 	int ret;
1974 
1975 	 if (RPC_IS_ASYNC(task)) {
1976 		/*
1977 		 * We want the AF_LOCAL connect to be resolved in the
1978 		 * filesystem namespace of the process making the rpc
1979 		 * call.  Thus we connect synchronously.
1980 		 *
1981 		 * If we want to support asynchronous AF_LOCAL calls,
1982 		 * we'll need to figure out how to pass a namespace to
1983 		 * connect.
1984 		 */
1985 		rpc_exit(task, -ENOTCONN);
1986 		return;
1987 	}
1988 	ret = xs_local_setup_socket(transport);
1989 	if (ret && !RPC_IS_SOFTCONN(task))
1990 		msleep_interruptible(15000);
1991 }
1992 
1993 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1994 /*
1995  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1996  * know that we have exclusive access to the socket), to guard against
1997  * races with xs_reset_transport.
1998  */
1999 static void xs_set_memalloc(struct rpc_xprt *xprt)
2000 {
2001 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2002 			xprt);
2003 
2004 	/*
2005 	 * If there's no sock, then we have nothing to set. The
2006 	 * reconnecting process will get it for us.
2007 	 */
2008 	if (!transport->inet)
2009 		return;
2010 	if (atomic_read(&xprt->swapper))
2011 		sk_set_memalloc(transport->inet);
2012 }
2013 
2014 /**
2015  * xs_enable_swap - Tag this transport as being used for swap.
2016  * @xprt: transport to tag
2017  *
2018  * Take a reference to this transport on behalf of the rpc_clnt, and
2019  * optionally mark it for swapping if it wasn't already.
2020  */
2021 static int
2022 xs_enable_swap(struct rpc_xprt *xprt)
2023 {
2024 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2025 
2026 	if (atomic_inc_return(&xprt->swapper) != 1)
2027 		return 0;
2028 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2029 		return -ERESTARTSYS;
2030 	if (xs->inet)
2031 		sk_set_memalloc(xs->inet);
2032 	xprt_release_xprt(xprt, NULL);
2033 	return 0;
2034 }
2035 
2036 /**
2037  * xs_disable_swap - Untag this transport as being used for swap.
2038  * @xprt: transport to tag
2039  *
2040  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2041  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2042  */
2043 static void
2044 xs_disable_swap(struct rpc_xprt *xprt)
2045 {
2046 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2047 
2048 	if (!atomic_dec_and_test(&xprt->swapper))
2049 		return;
2050 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2051 		return;
2052 	if (xs->inet)
2053 		sk_clear_memalloc(xs->inet);
2054 	xprt_release_xprt(xprt, NULL);
2055 }
2056 #else
2057 static void xs_set_memalloc(struct rpc_xprt *xprt)
2058 {
2059 }
2060 
2061 static int
2062 xs_enable_swap(struct rpc_xprt *xprt)
2063 {
2064 	return -EINVAL;
2065 }
2066 
2067 static void
2068 xs_disable_swap(struct rpc_xprt *xprt)
2069 {
2070 }
2071 #endif
2072 
2073 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2074 {
2075 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2076 
2077 	if (!transport->inet) {
2078 		struct sock *sk = sock->sk;
2079 
2080 		write_lock_bh(&sk->sk_callback_lock);
2081 
2082 		xs_save_old_callbacks(transport, sk);
2083 
2084 		sk->sk_user_data = xprt;
2085 		sk->sk_data_ready = xs_data_ready;
2086 		sk->sk_write_space = xs_udp_write_space;
2087 		sock_set_flag(sk, SOCK_FASYNC);
2088 
2089 		xprt_set_connected(xprt);
2090 
2091 		/* Reset to new socket */
2092 		transport->sock = sock;
2093 		transport->inet = sk;
2094 
2095 		xs_set_memalloc(xprt);
2096 
2097 		write_unlock_bh(&sk->sk_callback_lock);
2098 	}
2099 	xs_udp_do_set_buffer_size(xprt);
2100 
2101 	xprt->stat.connect_start = jiffies;
2102 }
2103 
2104 static void xs_udp_setup_socket(struct work_struct *work)
2105 {
2106 	struct sock_xprt *transport =
2107 		container_of(work, struct sock_xprt, connect_worker.work);
2108 	struct rpc_xprt *xprt = &transport->xprt;
2109 	struct socket *sock;
2110 	int status = -EIO;
2111 
2112 	sock = xs_create_sock(xprt, transport,
2113 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2114 			IPPROTO_UDP, false);
2115 	if (IS_ERR(sock))
2116 		goto out;
2117 
2118 	dprintk("RPC:       worker connecting xprt %p via %s to "
2119 				"%s (port %s)\n", xprt,
2120 			xprt->address_strings[RPC_DISPLAY_PROTO],
2121 			xprt->address_strings[RPC_DISPLAY_ADDR],
2122 			xprt->address_strings[RPC_DISPLAY_PORT]);
2123 
2124 	xs_udp_finish_connecting(xprt, sock);
2125 	trace_rpc_socket_connect(xprt, sock, 0);
2126 	status = 0;
2127 out:
2128 	xprt_clear_connecting(xprt);
2129 	xprt_unlock_connect(xprt, transport);
2130 	xprt_wake_pending_tasks(xprt, status);
2131 }
2132 
2133 /**
2134  * xs_tcp_shutdown - gracefully shut down a TCP socket
2135  * @xprt: transport
2136  *
2137  * Initiates a graceful shutdown of the TCP socket by calling the
2138  * equivalent of shutdown(SHUT_RDWR);
2139  */
2140 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2141 {
2142 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2143 	struct socket *sock = transport->sock;
2144 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2145 
2146 	if (sock == NULL)
2147 		return;
2148 	switch (skst) {
2149 	default:
2150 		kernel_sock_shutdown(sock, SHUT_RDWR);
2151 		trace_rpc_socket_shutdown(xprt, sock);
2152 		break;
2153 	case TCP_CLOSE:
2154 	case TCP_TIME_WAIT:
2155 		xs_reset_transport(transport);
2156 	}
2157 }
2158 
2159 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2160 		struct socket *sock)
2161 {
2162 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2163 	unsigned int keepidle;
2164 	unsigned int keepcnt;
2165 	unsigned int opt_on = 1;
2166 	unsigned int timeo;
2167 
2168 	spin_lock_bh(&xprt->transport_lock);
2169 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2170 	keepcnt = xprt->timeout->to_retries + 1;
2171 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2172 		(xprt->timeout->to_retries + 1);
2173 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2174 	spin_unlock_bh(&xprt->transport_lock);
2175 
2176 	/* TCP Keepalive options */
2177 	kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2178 			(char *)&opt_on, sizeof(opt_on));
2179 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2180 			(char *)&keepidle, sizeof(keepidle));
2181 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2182 			(char *)&keepidle, sizeof(keepidle));
2183 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2184 			(char *)&keepcnt, sizeof(keepcnt));
2185 
2186 	/* TCP user timeout (see RFC5482) */
2187 	kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2188 			(char *)&timeo, sizeof(timeo));
2189 }
2190 
2191 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2192 		unsigned long connect_timeout,
2193 		unsigned long reconnect_timeout)
2194 {
2195 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2196 	struct rpc_timeout to;
2197 	unsigned long initval;
2198 
2199 	spin_lock_bh(&xprt->transport_lock);
2200 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2201 		xprt->max_reconnect_timeout = reconnect_timeout;
2202 	if (connect_timeout < xprt->connect_timeout) {
2203 		memcpy(&to, xprt->timeout, sizeof(to));
2204 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2205 		/* Arbitrary lower limit */
2206 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2207 			initval = XS_TCP_INIT_REEST_TO << 1;
2208 		to.to_initval = initval;
2209 		to.to_maxval = initval;
2210 		memcpy(&transport->tcp_timeout, &to,
2211 				sizeof(transport->tcp_timeout));
2212 		xprt->timeout = &transport->tcp_timeout;
2213 		xprt->connect_timeout = connect_timeout;
2214 	}
2215 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2216 	spin_unlock_bh(&xprt->transport_lock);
2217 }
2218 
2219 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2220 {
2221 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2222 	int ret = -ENOTCONN;
2223 
2224 	if (!transport->inet) {
2225 		struct sock *sk = sock->sk;
2226 		unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2227 
2228 		/* Avoid temporary address, they are bad for long-lived
2229 		 * connections such as NFS mounts.
2230 		 * RFC4941, section 3.6 suggests that:
2231 		 *    Individual applications, which have specific
2232 		 *    knowledge about the normal duration of connections,
2233 		 *    MAY override this as appropriate.
2234 		 */
2235 		kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2236 				(char *)&addr_pref, sizeof(addr_pref));
2237 
2238 		xs_tcp_set_socket_timeouts(xprt, sock);
2239 
2240 		write_lock_bh(&sk->sk_callback_lock);
2241 
2242 		xs_save_old_callbacks(transport, sk);
2243 
2244 		sk->sk_user_data = xprt;
2245 		sk->sk_data_ready = xs_data_ready;
2246 		sk->sk_state_change = xs_tcp_state_change;
2247 		sk->sk_write_space = xs_tcp_write_space;
2248 		sock_set_flag(sk, SOCK_FASYNC);
2249 		sk->sk_error_report = xs_error_report;
2250 
2251 		/* socket options */
2252 		sock_reset_flag(sk, SOCK_LINGER);
2253 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2254 
2255 		xprt_clear_connected(xprt);
2256 
2257 		/* Reset to new socket */
2258 		transport->sock = sock;
2259 		transport->inet = sk;
2260 
2261 		write_unlock_bh(&sk->sk_callback_lock);
2262 	}
2263 
2264 	if (!xprt_bound(xprt))
2265 		goto out;
2266 
2267 	xs_set_memalloc(xprt);
2268 
2269 	/* Reset TCP record info */
2270 	xs_stream_reset_connect(transport);
2271 
2272 	/* Tell the socket layer to start connecting... */
2273 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2274 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2275 	switch (ret) {
2276 	case 0:
2277 		xs_set_srcport(transport, sock);
2278 		/* fall through */
2279 	case -EINPROGRESS:
2280 		/* SYN_SENT! */
2281 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2282 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2283 		break;
2284 	case -EADDRNOTAVAIL:
2285 		/* Source port number is unavailable. Try a new one! */
2286 		transport->srcport = 0;
2287 	}
2288 out:
2289 	return ret;
2290 }
2291 
2292 /**
2293  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2294  * @work: queued work item
2295  *
2296  * Invoked by a work queue tasklet.
2297  */
2298 static void xs_tcp_setup_socket(struct work_struct *work)
2299 {
2300 	struct sock_xprt *transport =
2301 		container_of(work, struct sock_xprt, connect_worker.work);
2302 	struct socket *sock = transport->sock;
2303 	struct rpc_xprt *xprt = &transport->xprt;
2304 	int status = -EIO;
2305 
2306 	if (!sock) {
2307 		sock = xs_create_sock(xprt, transport,
2308 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2309 				IPPROTO_TCP, true);
2310 		if (IS_ERR(sock)) {
2311 			status = PTR_ERR(sock);
2312 			goto out;
2313 		}
2314 	}
2315 
2316 	dprintk("RPC:       worker connecting xprt %p via %s to "
2317 				"%s (port %s)\n", xprt,
2318 			xprt->address_strings[RPC_DISPLAY_PROTO],
2319 			xprt->address_strings[RPC_DISPLAY_ADDR],
2320 			xprt->address_strings[RPC_DISPLAY_PORT]);
2321 
2322 	status = xs_tcp_finish_connecting(xprt, sock);
2323 	trace_rpc_socket_connect(xprt, sock, status);
2324 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2325 			xprt, -status, xprt_connected(xprt),
2326 			sock->sk->sk_state);
2327 	switch (status) {
2328 	default:
2329 		printk("%s: connect returned unhandled error %d\n",
2330 			__func__, status);
2331 		/* fall through */
2332 	case -EADDRNOTAVAIL:
2333 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2334 		 * and retry
2335 		 */
2336 		xs_tcp_force_close(xprt);
2337 		break;
2338 	case 0:
2339 	case -EINPROGRESS:
2340 	case -EALREADY:
2341 		xprt_unlock_connect(xprt, transport);
2342 		return;
2343 	case -EINVAL:
2344 		/* Happens, for instance, if the user specified a link
2345 		 * local IPv6 address without a scope-id.
2346 		 */
2347 	case -ECONNREFUSED:
2348 	case -ECONNRESET:
2349 	case -ENETDOWN:
2350 	case -ENETUNREACH:
2351 	case -EHOSTUNREACH:
2352 	case -EADDRINUSE:
2353 	case -ENOBUFS:
2354 		/*
2355 		 * xs_tcp_force_close() wakes tasks with -EIO.
2356 		 * We need to wake them first to ensure the
2357 		 * correct error code.
2358 		 */
2359 		xprt_wake_pending_tasks(xprt, status);
2360 		xs_tcp_force_close(xprt);
2361 		goto out;
2362 	}
2363 	status = -EAGAIN;
2364 out:
2365 	xprt_clear_connecting(xprt);
2366 	xprt_unlock_connect(xprt, transport);
2367 	xprt_wake_pending_tasks(xprt, status);
2368 }
2369 
2370 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2371 {
2372 	unsigned long start, now = jiffies;
2373 
2374 	start = xprt->stat.connect_start + xprt->reestablish_timeout;
2375 	if (time_after(start, now))
2376 		return start - now;
2377 	return 0;
2378 }
2379 
2380 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2381 {
2382 	xprt->reestablish_timeout <<= 1;
2383 	if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2384 		xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2385 	if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2386 		xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2387 }
2388 
2389 /**
2390  * xs_connect - connect a socket to a remote endpoint
2391  * @xprt: pointer to transport structure
2392  * @task: address of RPC task that manages state of connect request
2393  *
2394  * TCP: If the remote end dropped the connection, delay reconnecting.
2395  *
2396  * UDP socket connects are synchronous, but we use a work queue anyway
2397  * to guarantee that even unprivileged user processes can set up a
2398  * socket on a privileged port.
2399  *
2400  * If a UDP socket connect fails, the delay behavior here prevents
2401  * retry floods (hard mounts).
2402  */
2403 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2404 {
2405 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2406 	unsigned long delay = 0;
2407 
2408 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2409 
2410 	if (transport->sock != NULL) {
2411 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2412 				"seconds\n",
2413 				xprt, xprt->reestablish_timeout / HZ);
2414 
2415 		/* Start by resetting any existing state */
2416 		xs_reset_transport(transport);
2417 
2418 		delay = xs_reconnect_delay(xprt);
2419 		xs_reconnect_backoff(xprt);
2420 
2421 	} else
2422 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2423 
2424 	queue_delayed_work(xprtiod_workqueue,
2425 			&transport->connect_worker,
2426 			delay);
2427 }
2428 
2429 /**
2430  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2431  * @xprt: rpc_xprt struct containing statistics
2432  * @seq: output file
2433  *
2434  */
2435 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2436 {
2437 	long idle_time = 0;
2438 
2439 	if (xprt_connected(xprt))
2440 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2441 
2442 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2443 			"%llu %llu %lu %llu %llu\n",
2444 			xprt->stat.bind_count,
2445 			xprt->stat.connect_count,
2446 			xprt->stat.connect_time / HZ,
2447 			idle_time,
2448 			xprt->stat.sends,
2449 			xprt->stat.recvs,
2450 			xprt->stat.bad_xids,
2451 			xprt->stat.req_u,
2452 			xprt->stat.bklog_u,
2453 			xprt->stat.max_slots,
2454 			xprt->stat.sending_u,
2455 			xprt->stat.pending_u);
2456 }
2457 
2458 /**
2459  * xs_udp_print_stats - display UDP socket-specifc stats
2460  * @xprt: rpc_xprt struct containing statistics
2461  * @seq: output file
2462  *
2463  */
2464 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2465 {
2466 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2467 
2468 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2469 			"%lu %llu %llu\n",
2470 			transport->srcport,
2471 			xprt->stat.bind_count,
2472 			xprt->stat.sends,
2473 			xprt->stat.recvs,
2474 			xprt->stat.bad_xids,
2475 			xprt->stat.req_u,
2476 			xprt->stat.bklog_u,
2477 			xprt->stat.max_slots,
2478 			xprt->stat.sending_u,
2479 			xprt->stat.pending_u);
2480 }
2481 
2482 /**
2483  * xs_tcp_print_stats - display TCP socket-specifc stats
2484  * @xprt: rpc_xprt struct containing statistics
2485  * @seq: output file
2486  *
2487  */
2488 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2489 {
2490 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2491 	long idle_time = 0;
2492 
2493 	if (xprt_connected(xprt))
2494 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2495 
2496 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2497 			"%llu %llu %lu %llu %llu\n",
2498 			transport->srcport,
2499 			xprt->stat.bind_count,
2500 			xprt->stat.connect_count,
2501 			xprt->stat.connect_time / HZ,
2502 			idle_time,
2503 			xprt->stat.sends,
2504 			xprt->stat.recvs,
2505 			xprt->stat.bad_xids,
2506 			xprt->stat.req_u,
2507 			xprt->stat.bklog_u,
2508 			xprt->stat.max_slots,
2509 			xprt->stat.sending_u,
2510 			xprt->stat.pending_u);
2511 }
2512 
2513 /*
2514  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2515  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2516  * to use the server side send routines.
2517  */
2518 static int bc_malloc(struct rpc_task *task)
2519 {
2520 	struct rpc_rqst *rqst = task->tk_rqstp;
2521 	size_t size = rqst->rq_callsize;
2522 	struct page *page;
2523 	struct rpc_buffer *buf;
2524 
2525 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2526 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2527 			  size);
2528 		return -EINVAL;
2529 	}
2530 
2531 	page = alloc_page(GFP_KERNEL);
2532 	if (!page)
2533 		return -ENOMEM;
2534 
2535 	buf = page_address(page);
2536 	buf->len = PAGE_SIZE;
2537 
2538 	rqst->rq_buffer = buf->data;
2539 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2540 	return 0;
2541 }
2542 
2543 /*
2544  * Free the space allocated in the bc_alloc routine
2545  */
2546 static void bc_free(struct rpc_task *task)
2547 {
2548 	void *buffer = task->tk_rqstp->rq_buffer;
2549 	struct rpc_buffer *buf;
2550 
2551 	buf = container_of(buffer, struct rpc_buffer, data);
2552 	free_page((unsigned long)buf);
2553 }
2554 
2555 /*
2556  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2557  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2558  */
2559 static int bc_sendto(struct rpc_rqst *req)
2560 {
2561 	int len;
2562 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2563 	struct rpc_xprt *xprt = req->rq_xprt;
2564 	struct sock_xprt *transport =
2565 				container_of(xprt, struct sock_xprt, xprt);
2566 	struct socket *sock = transport->sock;
2567 	unsigned long headoff;
2568 	unsigned long tailoff;
2569 
2570 	xs_encode_stream_record_marker(xbufp);
2571 
2572 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2573 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2574 	len = svc_send_common(sock, xbufp,
2575 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2576 			      xbufp->tail[0].iov_base, tailoff);
2577 
2578 	if (len != xbufp->len) {
2579 		printk(KERN_NOTICE "Error sending entire callback!\n");
2580 		len = -EAGAIN;
2581 	}
2582 
2583 	return len;
2584 }
2585 
2586 /*
2587  * The send routine. Borrows from svc_send
2588  */
2589 static int bc_send_request(struct rpc_rqst *req)
2590 {
2591 	struct svc_xprt	*xprt;
2592 	int len;
2593 
2594 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2595 	/*
2596 	 * Get the server socket associated with this callback xprt
2597 	 */
2598 	xprt = req->rq_xprt->bc_xprt;
2599 
2600 	/*
2601 	 * Grab the mutex to serialize data as the connection is shared
2602 	 * with the fore channel
2603 	 */
2604 	mutex_lock(&xprt->xpt_mutex);
2605 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2606 		len = -ENOTCONN;
2607 	else
2608 		len = bc_sendto(req);
2609 	mutex_unlock(&xprt->xpt_mutex);
2610 
2611 	if (len > 0)
2612 		len = 0;
2613 
2614 	return len;
2615 }
2616 
2617 /*
2618  * The close routine. Since this is client initiated, we do nothing
2619  */
2620 
2621 static void bc_close(struct rpc_xprt *xprt)
2622 {
2623 }
2624 
2625 /*
2626  * The xprt destroy routine. Again, because this connection is client
2627  * initiated, we do nothing
2628  */
2629 
2630 static void bc_destroy(struct rpc_xprt *xprt)
2631 {
2632 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2633 
2634 	xs_xprt_free(xprt);
2635 	module_put(THIS_MODULE);
2636 }
2637 
2638 static const struct rpc_xprt_ops xs_local_ops = {
2639 	.reserve_xprt		= xprt_reserve_xprt,
2640 	.release_xprt		= xprt_release_xprt,
2641 	.alloc_slot		= xprt_alloc_slot,
2642 	.free_slot		= xprt_free_slot,
2643 	.rpcbind		= xs_local_rpcbind,
2644 	.set_port		= xs_local_set_port,
2645 	.connect		= xs_local_connect,
2646 	.buf_alloc		= rpc_malloc,
2647 	.buf_free		= rpc_free,
2648 	.prepare_request	= xs_stream_prepare_request,
2649 	.send_request		= xs_local_send_request,
2650 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2651 	.close			= xs_close,
2652 	.destroy		= xs_destroy,
2653 	.print_stats		= xs_local_print_stats,
2654 	.enable_swap		= xs_enable_swap,
2655 	.disable_swap		= xs_disable_swap,
2656 };
2657 
2658 static const struct rpc_xprt_ops xs_udp_ops = {
2659 	.set_buffer_size	= xs_udp_set_buffer_size,
2660 	.reserve_xprt		= xprt_reserve_xprt_cong,
2661 	.release_xprt		= xprt_release_xprt_cong,
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 	.buf_alloc		= rpc_malloc,
2668 	.buf_free		= rpc_free,
2669 	.send_request		= xs_udp_send_request,
2670 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2671 	.timer			= xs_udp_timer,
2672 	.release_request	= xprt_release_rqst_cong,
2673 	.close			= xs_close,
2674 	.destroy		= xs_destroy,
2675 	.print_stats		= xs_udp_print_stats,
2676 	.enable_swap		= xs_enable_swap,
2677 	.disable_swap		= xs_disable_swap,
2678 	.inject_disconnect	= xs_inject_disconnect,
2679 };
2680 
2681 static const struct rpc_xprt_ops xs_tcp_ops = {
2682 	.reserve_xprt		= xprt_reserve_xprt,
2683 	.release_xprt		= xprt_release_xprt,
2684 	.alloc_slot		= xprt_alloc_slot,
2685 	.free_slot		= xprt_free_slot,
2686 	.rpcbind		= rpcb_getport_async,
2687 	.set_port		= xs_set_port,
2688 	.connect		= xs_connect,
2689 	.buf_alloc		= rpc_malloc,
2690 	.buf_free		= rpc_free,
2691 	.prepare_request	= xs_stream_prepare_request,
2692 	.send_request		= xs_tcp_send_request,
2693 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2694 	.close			= xs_tcp_shutdown,
2695 	.destroy		= xs_destroy,
2696 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2697 	.print_stats		= xs_tcp_print_stats,
2698 	.enable_swap		= xs_enable_swap,
2699 	.disable_swap		= xs_disable_swap,
2700 	.inject_disconnect	= xs_inject_disconnect,
2701 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2702 	.bc_setup		= xprt_setup_bc,
2703 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2704 	.bc_free_rqst		= xprt_free_bc_rqst,
2705 	.bc_destroy		= xprt_destroy_bc,
2706 #endif
2707 };
2708 
2709 /*
2710  * The rpc_xprt_ops for the server backchannel
2711  */
2712 
2713 static const struct rpc_xprt_ops bc_tcp_ops = {
2714 	.reserve_xprt		= xprt_reserve_xprt,
2715 	.release_xprt		= xprt_release_xprt,
2716 	.alloc_slot		= xprt_alloc_slot,
2717 	.free_slot		= xprt_free_slot,
2718 	.buf_alloc		= bc_malloc,
2719 	.buf_free		= bc_free,
2720 	.send_request		= bc_send_request,
2721 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2722 	.close			= bc_close,
2723 	.destroy		= bc_destroy,
2724 	.print_stats		= xs_tcp_print_stats,
2725 	.enable_swap		= xs_enable_swap,
2726 	.disable_swap		= xs_disable_swap,
2727 	.inject_disconnect	= xs_inject_disconnect,
2728 };
2729 
2730 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2731 {
2732 	static const struct sockaddr_in sin = {
2733 		.sin_family		= AF_INET,
2734 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2735 	};
2736 	static const struct sockaddr_in6 sin6 = {
2737 		.sin6_family		= AF_INET6,
2738 		.sin6_addr		= IN6ADDR_ANY_INIT,
2739 	};
2740 
2741 	switch (family) {
2742 	case AF_LOCAL:
2743 		break;
2744 	case AF_INET:
2745 		memcpy(sap, &sin, sizeof(sin));
2746 		break;
2747 	case AF_INET6:
2748 		memcpy(sap, &sin6, sizeof(sin6));
2749 		break;
2750 	default:
2751 		dprintk("RPC:       %s: Bad address family\n", __func__);
2752 		return -EAFNOSUPPORT;
2753 	}
2754 	return 0;
2755 }
2756 
2757 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2758 				      unsigned int slot_table_size,
2759 				      unsigned int max_slot_table_size)
2760 {
2761 	struct rpc_xprt *xprt;
2762 	struct sock_xprt *new;
2763 
2764 	if (args->addrlen > sizeof(xprt->addr)) {
2765 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2766 		return ERR_PTR(-EBADF);
2767 	}
2768 
2769 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2770 			max_slot_table_size);
2771 	if (xprt == NULL) {
2772 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2773 				"rpc_xprt\n");
2774 		return ERR_PTR(-ENOMEM);
2775 	}
2776 
2777 	new = container_of(xprt, struct sock_xprt, xprt);
2778 	mutex_init(&new->recv_mutex);
2779 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2780 	xprt->addrlen = args->addrlen;
2781 	if (args->srcaddr)
2782 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2783 	else {
2784 		int err;
2785 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2786 					(struct sockaddr *)&new->srcaddr);
2787 		if (err != 0) {
2788 			xprt_free(xprt);
2789 			return ERR_PTR(err);
2790 		}
2791 	}
2792 
2793 	return xprt;
2794 }
2795 
2796 static const struct rpc_timeout xs_local_default_timeout = {
2797 	.to_initval = 10 * HZ,
2798 	.to_maxval = 10 * HZ,
2799 	.to_retries = 2,
2800 };
2801 
2802 /**
2803  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2804  * @args: rpc transport creation arguments
2805  *
2806  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2807  */
2808 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2809 {
2810 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2811 	struct sock_xprt *transport;
2812 	struct rpc_xprt *xprt;
2813 	struct rpc_xprt *ret;
2814 
2815 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2816 			xprt_max_tcp_slot_table_entries);
2817 	if (IS_ERR(xprt))
2818 		return xprt;
2819 	transport = container_of(xprt, struct sock_xprt, xprt);
2820 
2821 	xprt->prot = 0;
2822 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2823 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2824 
2825 	xprt->bind_timeout = XS_BIND_TO;
2826 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2827 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2828 
2829 	xprt->ops = &xs_local_ops;
2830 	xprt->timeout = &xs_local_default_timeout;
2831 
2832 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2833 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2834 
2835 	switch (sun->sun_family) {
2836 	case AF_LOCAL:
2837 		if (sun->sun_path[0] != '/') {
2838 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2839 					sun->sun_path);
2840 			ret = ERR_PTR(-EINVAL);
2841 			goto out_err;
2842 		}
2843 		xprt_set_bound(xprt);
2844 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2845 		ret = ERR_PTR(xs_local_setup_socket(transport));
2846 		if (ret)
2847 			goto out_err;
2848 		break;
2849 	default:
2850 		ret = ERR_PTR(-EAFNOSUPPORT);
2851 		goto out_err;
2852 	}
2853 
2854 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2855 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2856 
2857 	if (try_module_get(THIS_MODULE))
2858 		return xprt;
2859 	ret = ERR_PTR(-EINVAL);
2860 out_err:
2861 	xs_xprt_free(xprt);
2862 	return ret;
2863 }
2864 
2865 static const struct rpc_timeout xs_udp_default_timeout = {
2866 	.to_initval = 5 * HZ,
2867 	.to_maxval = 30 * HZ,
2868 	.to_increment = 5 * HZ,
2869 	.to_retries = 5,
2870 };
2871 
2872 /**
2873  * xs_setup_udp - Set up transport to use a UDP socket
2874  * @args: rpc transport creation arguments
2875  *
2876  */
2877 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2878 {
2879 	struct sockaddr *addr = args->dstaddr;
2880 	struct rpc_xprt *xprt;
2881 	struct sock_xprt *transport;
2882 	struct rpc_xprt *ret;
2883 
2884 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2885 			xprt_udp_slot_table_entries);
2886 	if (IS_ERR(xprt))
2887 		return xprt;
2888 	transport = container_of(xprt, struct sock_xprt, xprt);
2889 
2890 	xprt->prot = IPPROTO_UDP;
2891 	xprt->tsh_size = 0;
2892 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2893 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2894 
2895 	xprt->bind_timeout = XS_BIND_TO;
2896 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2897 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2898 
2899 	xprt->ops = &xs_udp_ops;
2900 
2901 	xprt->timeout = &xs_udp_default_timeout;
2902 
2903 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2904 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2905 
2906 	switch (addr->sa_family) {
2907 	case AF_INET:
2908 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2909 			xprt_set_bound(xprt);
2910 
2911 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2912 		break;
2913 	case AF_INET6:
2914 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2915 			xprt_set_bound(xprt);
2916 
2917 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2918 		break;
2919 	default:
2920 		ret = ERR_PTR(-EAFNOSUPPORT);
2921 		goto out_err;
2922 	}
2923 
2924 	if (xprt_bound(xprt))
2925 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2926 				xprt->address_strings[RPC_DISPLAY_ADDR],
2927 				xprt->address_strings[RPC_DISPLAY_PORT],
2928 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2929 	else
2930 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2931 				xprt->address_strings[RPC_DISPLAY_ADDR],
2932 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2933 
2934 	if (try_module_get(THIS_MODULE))
2935 		return xprt;
2936 	ret = ERR_PTR(-EINVAL);
2937 out_err:
2938 	xs_xprt_free(xprt);
2939 	return ret;
2940 }
2941 
2942 static const struct rpc_timeout xs_tcp_default_timeout = {
2943 	.to_initval = 60 * HZ,
2944 	.to_maxval = 60 * HZ,
2945 	.to_retries = 2,
2946 };
2947 
2948 /**
2949  * xs_setup_tcp - Set up transport to use a TCP socket
2950  * @args: rpc transport creation arguments
2951  *
2952  */
2953 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2954 {
2955 	struct sockaddr *addr = args->dstaddr;
2956 	struct rpc_xprt *xprt;
2957 	struct sock_xprt *transport;
2958 	struct rpc_xprt *ret;
2959 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2960 
2961 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2962 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2963 
2964 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2965 			max_slot_table_size);
2966 	if (IS_ERR(xprt))
2967 		return xprt;
2968 	transport = container_of(xprt, struct sock_xprt, xprt);
2969 
2970 	xprt->prot = IPPROTO_TCP;
2971 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2972 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2973 
2974 	xprt->bind_timeout = XS_BIND_TO;
2975 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2976 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2977 
2978 	xprt->ops = &xs_tcp_ops;
2979 	xprt->timeout = &xs_tcp_default_timeout;
2980 
2981 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2982 	xprt->connect_timeout = xprt->timeout->to_initval *
2983 		(xprt->timeout->to_retries + 1);
2984 
2985 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2986 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2987 
2988 	switch (addr->sa_family) {
2989 	case AF_INET:
2990 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2991 			xprt_set_bound(xprt);
2992 
2993 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2994 		break;
2995 	case AF_INET6:
2996 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2997 			xprt_set_bound(xprt);
2998 
2999 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3000 		break;
3001 	default:
3002 		ret = ERR_PTR(-EAFNOSUPPORT);
3003 		goto out_err;
3004 	}
3005 
3006 	if (xprt_bound(xprt))
3007 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3008 				xprt->address_strings[RPC_DISPLAY_ADDR],
3009 				xprt->address_strings[RPC_DISPLAY_PORT],
3010 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3011 	else
3012 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3013 				xprt->address_strings[RPC_DISPLAY_ADDR],
3014 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3015 
3016 	if (try_module_get(THIS_MODULE))
3017 		return xprt;
3018 	ret = ERR_PTR(-EINVAL);
3019 out_err:
3020 	xs_xprt_free(xprt);
3021 	return ret;
3022 }
3023 
3024 /**
3025  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3026  * @args: rpc transport creation arguments
3027  *
3028  */
3029 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3030 {
3031 	struct sockaddr *addr = args->dstaddr;
3032 	struct rpc_xprt *xprt;
3033 	struct sock_xprt *transport;
3034 	struct svc_sock *bc_sock;
3035 	struct rpc_xprt *ret;
3036 
3037 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3038 			xprt_tcp_slot_table_entries);
3039 	if (IS_ERR(xprt))
3040 		return xprt;
3041 	transport = container_of(xprt, struct sock_xprt, xprt);
3042 
3043 	xprt->prot = IPPROTO_TCP;
3044 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3045 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3046 	xprt->timeout = &xs_tcp_default_timeout;
3047 
3048 	/* backchannel */
3049 	xprt_set_bound(xprt);
3050 	xprt->bind_timeout = 0;
3051 	xprt->reestablish_timeout = 0;
3052 	xprt->idle_timeout = 0;
3053 
3054 	xprt->ops = &bc_tcp_ops;
3055 
3056 	switch (addr->sa_family) {
3057 	case AF_INET:
3058 		xs_format_peer_addresses(xprt, "tcp",
3059 					 RPCBIND_NETID_TCP);
3060 		break;
3061 	case AF_INET6:
3062 		xs_format_peer_addresses(xprt, "tcp",
3063 				   RPCBIND_NETID_TCP6);
3064 		break;
3065 	default:
3066 		ret = ERR_PTR(-EAFNOSUPPORT);
3067 		goto out_err;
3068 	}
3069 
3070 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3071 			xprt->address_strings[RPC_DISPLAY_ADDR],
3072 			xprt->address_strings[RPC_DISPLAY_PORT],
3073 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3074 
3075 	/*
3076 	 * Once we've associated a backchannel xprt with a connection,
3077 	 * we want to keep it around as long as the connection lasts,
3078 	 * in case we need to start using it for a backchannel again;
3079 	 * this reference won't be dropped until bc_xprt is destroyed.
3080 	 */
3081 	xprt_get(xprt);
3082 	args->bc_xprt->xpt_bc_xprt = xprt;
3083 	xprt->bc_xprt = args->bc_xprt;
3084 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3085 	transport->sock = bc_sock->sk_sock;
3086 	transport->inet = bc_sock->sk_sk;
3087 
3088 	/*
3089 	 * Since we don't want connections for the backchannel, we set
3090 	 * the xprt status to connected
3091 	 */
3092 	xprt_set_connected(xprt);
3093 
3094 	if (try_module_get(THIS_MODULE))
3095 		return xprt;
3096 
3097 	args->bc_xprt->xpt_bc_xprt = NULL;
3098 	args->bc_xprt->xpt_bc_xps = NULL;
3099 	xprt_put(xprt);
3100 	ret = ERR_PTR(-EINVAL);
3101 out_err:
3102 	xs_xprt_free(xprt);
3103 	return ret;
3104 }
3105 
3106 static struct xprt_class	xs_local_transport = {
3107 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3108 	.name		= "named UNIX socket",
3109 	.owner		= THIS_MODULE,
3110 	.ident		= XPRT_TRANSPORT_LOCAL,
3111 	.setup		= xs_setup_local,
3112 };
3113 
3114 static struct xprt_class	xs_udp_transport = {
3115 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3116 	.name		= "udp",
3117 	.owner		= THIS_MODULE,
3118 	.ident		= XPRT_TRANSPORT_UDP,
3119 	.setup		= xs_setup_udp,
3120 };
3121 
3122 static struct xprt_class	xs_tcp_transport = {
3123 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3124 	.name		= "tcp",
3125 	.owner		= THIS_MODULE,
3126 	.ident		= XPRT_TRANSPORT_TCP,
3127 	.setup		= xs_setup_tcp,
3128 };
3129 
3130 static struct xprt_class	xs_bc_tcp_transport = {
3131 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3132 	.name		= "tcp NFSv4.1 backchannel",
3133 	.owner		= THIS_MODULE,
3134 	.ident		= XPRT_TRANSPORT_BC_TCP,
3135 	.setup		= xs_setup_bc_tcp,
3136 };
3137 
3138 /**
3139  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3140  *
3141  */
3142 int init_socket_xprt(void)
3143 {
3144 	if (!sunrpc_table_header)
3145 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3146 
3147 	xprt_register_transport(&xs_local_transport);
3148 	xprt_register_transport(&xs_udp_transport);
3149 	xprt_register_transport(&xs_tcp_transport);
3150 	xprt_register_transport(&xs_bc_tcp_transport);
3151 
3152 	return 0;
3153 }
3154 
3155 /**
3156  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3157  *
3158  */
3159 void cleanup_socket_xprt(void)
3160 {
3161 	if (sunrpc_table_header) {
3162 		unregister_sysctl_table(sunrpc_table_header);
3163 		sunrpc_table_header = NULL;
3164 	}
3165 
3166 	xprt_unregister_transport(&xs_local_transport);
3167 	xprt_unregister_transport(&xs_udp_transport);
3168 	xprt_unregister_transport(&xs_tcp_transport);
3169 	xprt_unregister_transport(&xs_bc_tcp_transport);
3170 }
3171 
3172 static int param_set_uint_minmax(const char *val,
3173 		const struct kernel_param *kp,
3174 		unsigned int min, unsigned int max)
3175 {
3176 	unsigned int num;
3177 	int ret;
3178 
3179 	if (!val)
3180 		return -EINVAL;
3181 	ret = kstrtouint(val, 0, &num);
3182 	if (ret)
3183 		return ret;
3184 	if (num < min || num > max)
3185 		return -EINVAL;
3186 	*((unsigned int *)kp->arg) = num;
3187 	return 0;
3188 }
3189 
3190 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3191 {
3192 	return param_set_uint_minmax(val, kp,
3193 			RPC_MIN_RESVPORT,
3194 			RPC_MAX_RESVPORT);
3195 }
3196 
3197 static const struct kernel_param_ops param_ops_portnr = {
3198 	.set = param_set_portnr,
3199 	.get = param_get_uint,
3200 };
3201 
3202 #define param_check_portnr(name, p) \
3203 	__param_check(name, p, unsigned int);
3204 
3205 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3206 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3207 
3208 static int param_set_slot_table_size(const char *val,
3209 				     const struct kernel_param *kp)
3210 {
3211 	return param_set_uint_minmax(val, kp,
3212 			RPC_MIN_SLOT_TABLE,
3213 			RPC_MAX_SLOT_TABLE);
3214 }
3215 
3216 static const struct kernel_param_ops param_ops_slot_table_size = {
3217 	.set = param_set_slot_table_size,
3218 	.get = param_get_uint,
3219 };
3220 
3221 #define param_check_slot_table_size(name, p) \
3222 	__param_check(name, p, unsigned int);
3223 
3224 static int param_set_max_slot_table_size(const char *val,
3225 				     const struct kernel_param *kp)
3226 {
3227 	return param_set_uint_minmax(val, kp,
3228 			RPC_MIN_SLOT_TABLE,
3229 			RPC_MAX_SLOT_TABLE_LIMIT);
3230 }
3231 
3232 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3233 	.set = param_set_max_slot_table_size,
3234 	.get = param_get_uint,
3235 };
3236 
3237 #define param_check_max_slot_table_size(name, p) \
3238 	__param_check(name, p, unsigned int);
3239 
3240 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3241 		   slot_table_size, 0644);
3242 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3243 		   max_slot_table_size, 0644);
3244 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3245 		   slot_table_size, 0644);
3246