xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 80483c3a)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44 
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49 
50 #include <trace/events/sunrpc.h>
51 
52 #include "sunrpc.h"
53 
54 static void xs_close(struct rpc_xprt *xprt);
55 
56 /*
57  * xprtsock tunables
58  */
59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
62 
63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
65 
66 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
67 
68 #define XS_TCP_LINGER_TO	(15U * HZ)
69 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
70 
71 /*
72  * We can register our own files under /proc/sys/sunrpc by
73  * calling register_sysctl_table() again.  The files in that
74  * directory become the union of all files registered there.
75  *
76  * We simply need to make sure that we don't collide with
77  * someone else's file names!
78  */
79 
80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
85 
86 static struct ctl_table_header *sunrpc_table_header;
87 
88 /*
89  * FIXME: changing the UDP slot table size should also resize the UDP
90  *        socket buffers for existing UDP transports
91  */
92 static struct ctl_table xs_tunables_table[] = {
93 	{
94 		.procname	= "udp_slot_table_entries",
95 		.data		= &xprt_udp_slot_table_entries,
96 		.maxlen		= sizeof(unsigned int),
97 		.mode		= 0644,
98 		.proc_handler	= proc_dointvec_minmax,
99 		.extra1		= &min_slot_table_size,
100 		.extra2		= &max_slot_table_size
101 	},
102 	{
103 		.procname	= "tcp_slot_table_entries",
104 		.data		= &xprt_tcp_slot_table_entries,
105 		.maxlen		= sizeof(unsigned int),
106 		.mode		= 0644,
107 		.proc_handler	= proc_dointvec_minmax,
108 		.extra1		= &min_slot_table_size,
109 		.extra2		= &max_slot_table_size
110 	},
111 	{
112 		.procname	= "tcp_max_slot_table_entries",
113 		.data		= &xprt_max_tcp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_tcp_slot_table_limit
119 	},
120 	{
121 		.procname	= "min_resvport",
122 		.data		= &xprt_min_resvport,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &xprt_min_resvport_limit,
127 		.extra2		= &xprt_max_resvport
128 	},
129 	{
130 		.procname	= "max_resvport",
131 		.data		= &xprt_max_resvport,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &xprt_min_resvport,
136 		.extra2		= &xprt_max_resvport_limit
137 	},
138 	{
139 		.procname	= "tcp_fin_timeout",
140 		.data		= &xs_tcp_fin_timeout,
141 		.maxlen		= sizeof(xs_tcp_fin_timeout),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_jiffies,
144 	},
145 	{ },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149 	{
150 		.procname	= "sunrpc",
151 		.mode		= 0555,
152 		.child		= xs_tunables_table
153 	},
154 	{ },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO		(60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO		(2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
180 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
188 
189 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
190 # undef  RPC_DEBUG_DATA
191 # define RPCDBG_FACILITY	RPCDBG_TRANS
192 #endif
193 
194 #ifdef RPC_DEBUG_DATA
195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
196 {
197 	u8 *buf = (u8 *) packet;
198 	int j;
199 
200 	dprintk("RPC:       %s\n", msg);
201 	for (j = 0; j < count && j < 128; j += 4) {
202 		if (!(j & 31)) {
203 			if (j)
204 				dprintk("\n");
205 			dprintk("0x%04x ", j);
206 		}
207 		dprintk("%02x%02x%02x%02x ",
208 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
209 	}
210 	dprintk("\n");
211 }
212 #else
213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
214 {
215 	/* NOP */
216 }
217 #endif
218 
219 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
220 {
221 	return (struct rpc_xprt *) sk->sk_user_data;
222 }
223 
224 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
225 {
226 	return (struct sockaddr *) &xprt->addr;
227 }
228 
229 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
230 {
231 	return (struct sockaddr_un *) &xprt->addr;
232 }
233 
234 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
235 {
236 	return (struct sockaddr_in *) &xprt->addr;
237 }
238 
239 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
240 {
241 	return (struct sockaddr_in6 *) &xprt->addr;
242 }
243 
244 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
245 {
246 	struct sockaddr *sap = xs_addr(xprt);
247 	struct sockaddr_in6 *sin6;
248 	struct sockaddr_in *sin;
249 	struct sockaddr_un *sun;
250 	char buf[128];
251 
252 	switch (sap->sa_family) {
253 	case AF_LOCAL:
254 		sun = xs_addr_un(xprt);
255 		strlcpy(buf, sun->sun_path, sizeof(buf));
256 		xprt->address_strings[RPC_DISPLAY_ADDR] =
257 						kstrdup(buf, GFP_KERNEL);
258 		break;
259 	case AF_INET:
260 		(void)rpc_ntop(sap, buf, sizeof(buf));
261 		xprt->address_strings[RPC_DISPLAY_ADDR] =
262 						kstrdup(buf, GFP_KERNEL);
263 		sin = xs_addr_in(xprt);
264 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
265 		break;
266 	case AF_INET6:
267 		(void)rpc_ntop(sap, buf, sizeof(buf));
268 		xprt->address_strings[RPC_DISPLAY_ADDR] =
269 						kstrdup(buf, GFP_KERNEL);
270 		sin6 = xs_addr_in6(xprt);
271 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
272 		break;
273 	default:
274 		BUG();
275 	}
276 
277 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
278 }
279 
280 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
281 {
282 	struct sockaddr *sap = xs_addr(xprt);
283 	char buf[128];
284 
285 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
286 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
287 
288 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
290 }
291 
292 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
293 				     const char *protocol,
294 				     const char *netid)
295 {
296 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
297 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
298 	xs_format_common_peer_addresses(xprt);
299 	xs_format_common_peer_ports(xprt);
300 }
301 
302 static void xs_update_peer_port(struct rpc_xprt *xprt)
303 {
304 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
305 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
306 
307 	xs_format_common_peer_ports(xprt);
308 }
309 
310 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
311 {
312 	unsigned int i;
313 
314 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
315 		switch (i) {
316 		case RPC_DISPLAY_PROTO:
317 		case RPC_DISPLAY_NETID:
318 			continue;
319 		default:
320 			kfree(xprt->address_strings[i]);
321 		}
322 }
323 
324 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
325 
326 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
327 {
328 	struct msghdr msg = {
329 		.msg_name	= addr,
330 		.msg_namelen	= addrlen,
331 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
332 	};
333 	struct kvec iov = {
334 		.iov_base	= vec->iov_base + base,
335 		.iov_len	= vec->iov_len - base,
336 	};
337 
338 	if (iov.iov_len != 0)
339 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
340 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
341 }
342 
343 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
344 {
345 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
346 			int offset, size_t size, int flags);
347 	struct page **ppage;
348 	unsigned int remainder;
349 	int err;
350 
351 	remainder = xdr->page_len - base;
352 	base += xdr->page_base;
353 	ppage = xdr->pages + (base >> PAGE_SHIFT);
354 	base &= ~PAGE_MASK;
355 	do_sendpage = sock->ops->sendpage;
356 	if (!zerocopy)
357 		do_sendpage = sock_no_sendpage;
358 	for(;;) {
359 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
360 		int flags = XS_SENDMSG_FLAGS;
361 
362 		remainder -= len;
363 		if (more)
364 			flags |= MSG_MORE;
365 		if (remainder != 0)
366 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
367 		err = do_sendpage(sock, *ppage, base, len, flags);
368 		if (remainder == 0 || err != len)
369 			break;
370 		*sent_p += err;
371 		ppage++;
372 		base = 0;
373 	}
374 	if (err > 0) {
375 		*sent_p += err;
376 		err = 0;
377 	}
378 	return err;
379 }
380 
381 /**
382  * xs_sendpages - write pages directly to a socket
383  * @sock: socket to send on
384  * @addr: UDP only -- address of destination
385  * @addrlen: UDP only -- length of destination address
386  * @xdr: buffer containing this request
387  * @base: starting position in the buffer
388  * @zerocopy: true if it is safe to use sendpage()
389  * @sent_p: return the total number of bytes successfully queued for sending
390  *
391  */
392 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
393 {
394 	unsigned int remainder = xdr->len - base;
395 	int err = 0;
396 	int sent = 0;
397 
398 	if (unlikely(!sock))
399 		return -ENOTSOCK;
400 
401 	if (base != 0) {
402 		addr = NULL;
403 		addrlen = 0;
404 	}
405 
406 	if (base < xdr->head[0].iov_len || addr != NULL) {
407 		unsigned int len = xdr->head[0].iov_len - base;
408 		remainder -= len;
409 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
410 		if (remainder == 0 || err != len)
411 			goto out;
412 		*sent_p += err;
413 		base = 0;
414 	} else
415 		base -= xdr->head[0].iov_len;
416 
417 	if (base < xdr->page_len) {
418 		unsigned int len = xdr->page_len - base;
419 		remainder -= len;
420 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
421 		*sent_p += sent;
422 		if (remainder == 0 || sent != len)
423 			goto out;
424 		base = 0;
425 	} else
426 		base -= xdr->page_len;
427 
428 	if (base >= xdr->tail[0].iov_len)
429 		return 0;
430 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
431 out:
432 	if (err > 0) {
433 		*sent_p += err;
434 		err = 0;
435 	}
436 	return err;
437 }
438 
439 static void xs_nospace_callback(struct rpc_task *task)
440 {
441 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
442 
443 	transport->inet->sk_write_pending--;
444 }
445 
446 /**
447  * xs_nospace - place task on wait queue if transmit was incomplete
448  * @task: task to put to sleep
449  *
450  */
451 static int xs_nospace(struct rpc_task *task)
452 {
453 	struct rpc_rqst *req = task->tk_rqstp;
454 	struct rpc_xprt *xprt = req->rq_xprt;
455 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
456 	struct sock *sk = transport->inet;
457 	int ret = -EAGAIN;
458 
459 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
460 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
461 			req->rq_slen);
462 
463 	/* Protect against races with write_space */
464 	spin_lock_bh(&xprt->transport_lock);
465 
466 	/* Don't race with disconnect */
467 	if (xprt_connected(xprt)) {
468 		/* wait for more buffer space */
469 		sk->sk_write_pending++;
470 		xprt_wait_for_buffer_space(task, xs_nospace_callback);
471 	} else
472 		ret = -ENOTCONN;
473 
474 	spin_unlock_bh(&xprt->transport_lock);
475 
476 	/* Race breaker in case memory is freed before above code is called */
477 	sk->sk_write_space(sk);
478 	return ret;
479 }
480 
481 /*
482  * Construct a stream transport record marker in @buf.
483  */
484 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
485 {
486 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
487 	rpc_fraghdr *base = buf->head[0].iov_base;
488 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
489 }
490 
491 /**
492  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
493  * @task: RPC task that manages the state of an RPC request
494  *
495  * Return values:
496  *        0:	The request has been sent
497  *   EAGAIN:	The socket was blocked, please call again later to
498  *		complete the request
499  * ENOTCONN:	Caller needs to invoke connect logic then call again
500  *    other:	Some other error occured, the request was not sent
501  */
502 static int xs_local_send_request(struct rpc_task *task)
503 {
504 	struct rpc_rqst *req = task->tk_rqstp;
505 	struct rpc_xprt *xprt = req->rq_xprt;
506 	struct sock_xprt *transport =
507 				container_of(xprt, struct sock_xprt, xprt);
508 	struct xdr_buf *xdr = &req->rq_snd_buf;
509 	int status;
510 	int sent = 0;
511 
512 	xs_encode_stream_record_marker(&req->rq_snd_buf);
513 
514 	xs_pktdump("packet data:",
515 			req->rq_svec->iov_base, req->rq_svec->iov_len);
516 
517 	status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
518 			      true, &sent);
519 	dprintk("RPC:       %s(%u) = %d\n",
520 			__func__, xdr->len - req->rq_bytes_sent, status);
521 
522 	if (status == -EAGAIN && sock_writeable(transport->inet))
523 		status = -ENOBUFS;
524 
525 	if (likely(sent > 0) || status == 0) {
526 		req->rq_bytes_sent += sent;
527 		req->rq_xmit_bytes_sent += sent;
528 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
529 			req->rq_bytes_sent = 0;
530 			return 0;
531 		}
532 		status = -EAGAIN;
533 	}
534 
535 	switch (status) {
536 	case -ENOBUFS:
537 		break;
538 	case -EAGAIN:
539 		status = xs_nospace(task);
540 		break;
541 	default:
542 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
543 			-status);
544 	case -EPIPE:
545 		xs_close(xprt);
546 		status = -ENOTCONN;
547 	}
548 
549 	return status;
550 }
551 
552 /**
553  * xs_udp_send_request - write an RPC request to a UDP socket
554  * @task: address of RPC task that manages the state of an RPC request
555  *
556  * Return values:
557  *        0:	The request has been sent
558  *   EAGAIN:	The socket was blocked, please call again later to
559  *		complete the request
560  * ENOTCONN:	Caller needs to invoke connect logic then call again
561  *    other:	Some other error occurred, the request was not sent
562  */
563 static int xs_udp_send_request(struct rpc_task *task)
564 {
565 	struct rpc_rqst *req = task->tk_rqstp;
566 	struct rpc_xprt *xprt = req->rq_xprt;
567 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
568 	struct xdr_buf *xdr = &req->rq_snd_buf;
569 	int sent = 0;
570 	int status;
571 
572 	xs_pktdump("packet data:",
573 				req->rq_svec->iov_base,
574 				req->rq_svec->iov_len);
575 
576 	if (!xprt_bound(xprt))
577 		return -ENOTCONN;
578 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
579 			      xdr, req->rq_bytes_sent, true, &sent);
580 
581 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
582 			xdr->len - req->rq_bytes_sent, status);
583 
584 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
585 	if (status == -EPERM)
586 		goto process_status;
587 
588 	if (status == -EAGAIN && sock_writeable(transport->inet))
589 		status = -ENOBUFS;
590 
591 	if (sent > 0 || status == 0) {
592 		req->rq_xmit_bytes_sent += sent;
593 		if (sent >= req->rq_slen)
594 			return 0;
595 		/* Still some bytes left; set up for a retry later. */
596 		status = -EAGAIN;
597 	}
598 
599 process_status:
600 	switch (status) {
601 	case -ENOTSOCK:
602 		status = -ENOTCONN;
603 		/* Should we call xs_close() here? */
604 		break;
605 	case -EAGAIN:
606 		status = xs_nospace(task);
607 		break;
608 	case -ENETUNREACH:
609 	case -ENOBUFS:
610 	case -EPIPE:
611 	case -ECONNREFUSED:
612 	case -EPERM:
613 		/* When the server has died, an ICMP port unreachable message
614 		 * prompts ECONNREFUSED. */
615 		break;
616 	default:
617 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
618 			-status);
619 	}
620 
621 	return status;
622 }
623 
624 /**
625  * xs_tcp_send_request - write an RPC request to a TCP socket
626  * @task: address of RPC task that manages the state of an RPC request
627  *
628  * Return values:
629  *        0:	The request has been sent
630  *   EAGAIN:	The socket was blocked, please call again later to
631  *		complete the request
632  * ENOTCONN:	Caller needs to invoke connect logic then call again
633  *    other:	Some other error occurred, the request was not sent
634  *
635  * XXX: In the case of soft timeouts, should we eventually give up
636  *	if sendmsg is not able to make progress?
637  */
638 static int xs_tcp_send_request(struct rpc_task *task)
639 {
640 	struct rpc_rqst *req = task->tk_rqstp;
641 	struct rpc_xprt *xprt = req->rq_xprt;
642 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
643 	struct xdr_buf *xdr = &req->rq_snd_buf;
644 	bool zerocopy = true;
645 	bool vm_wait = false;
646 	int status;
647 	int sent;
648 
649 	xs_encode_stream_record_marker(&req->rq_snd_buf);
650 
651 	xs_pktdump("packet data:",
652 				req->rq_svec->iov_base,
653 				req->rq_svec->iov_len);
654 	/* Don't use zero copy if this is a resend. If the RPC call
655 	 * completes while the socket holds a reference to the pages,
656 	 * then we may end up resending corrupted data.
657 	 */
658 	if (task->tk_flags & RPC_TASK_SENT)
659 		zerocopy = false;
660 
661 	/* Continue transmitting the packet/record. We must be careful
662 	 * to cope with writespace callbacks arriving _after_ we have
663 	 * called sendmsg(). */
664 	while (1) {
665 		sent = 0;
666 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
667 				      req->rq_bytes_sent, zerocopy, &sent);
668 
669 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
670 				xdr->len - req->rq_bytes_sent, status);
671 
672 		/* If we've sent the entire packet, immediately
673 		 * reset the count of bytes sent. */
674 		req->rq_bytes_sent += sent;
675 		req->rq_xmit_bytes_sent += sent;
676 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
677 			req->rq_bytes_sent = 0;
678 			return 0;
679 		}
680 
681 		WARN_ON_ONCE(sent == 0 && status == 0);
682 
683 		if (status == -EAGAIN ) {
684 			/*
685 			 * Return EAGAIN if we're sure we're hitting the
686 			 * socket send buffer limits.
687 			 */
688 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
689 				break;
690 			/*
691 			 * Did we hit a memory allocation failure?
692 			 */
693 			if (sent == 0) {
694 				status = -ENOBUFS;
695 				if (vm_wait)
696 					break;
697 				/* Retry, knowing now that we're below the
698 				 * socket send buffer limit
699 				 */
700 				vm_wait = true;
701 			}
702 			continue;
703 		}
704 		if (status < 0)
705 			break;
706 		vm_wait = false;
707 	}
708 
709 	switch (status) {
710 	case -ENOTSOCK:
711 		status = -ENOTCONN;
712 		/* Should we call xs_close() here? */
713 		break;
714 	case -EAGAIN:
715 		status = xs_nospace(task);
716 		break;
717 	case -ECONNRESET:
718 	case -ECONNREFUSED:
719 	case -ENOTCONN:
720 	case -EADDRINUSE:
721 	case -ENOBUFS:
722 	case -EPIPE:
723 		break;
724 	default:
725 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
726 			-status);
727 	}
728 
729 	return status;
730 }
731 
732 /**
733  * xs_tcp_release_xprt - clean up after a tcp transmission
734  * @xprt: transport
735  * @task: rpc task
736  *
737  * This cleans up if an error causes us to abort the transmission of a request.
738  * In this case, the socket may need to be reset in order to avoid confusing
739  * the server.
740  */
741 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
742 {
743 	struct rpc_rqst *req;
744 
745 	if (task != xprt->snd_task)
746 		return;
747 	if (task == NULL)
748 		goto out_release;
749 	req = task->tk_rqstp;
750 	if (req == NULL)
751 		goto out_release;
752 	if (req->rq_bytes_sent == 0)
753 		goto out_release;
754 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
755 		goto out_release;
756 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
757 out_release:
758 	xprt_release_xprt(xprt, task);
759 }
760 
761 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
762 {
763 	transport->old_data_ready = sk->sk_data_ready;
764 	transport->old_state_change = sk->sk_state_change;
765 	transport->old_write_space = sk->sk_write_space;
766 	transport->old_error_report = sk->sk_error_report;
767 }
768 
769 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
770 {
771 	sk->sk_data_ready = transport->old_data_ready;
772 	sk->sk_state_change = transport->old_state_change;
773 	sk->sk_write_space = transport->old_write_space;
774 	sk->sk_error_report = transport->old_error_report;
775 }
776 
777 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
778 {
779 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
780 
781 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
782 }
783 
784 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
785 {
786 	smp_mb__before_atomic();
787 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
788 	clear_bit(XPRT_CLOSING, &xprt->state);
789 	xs_sock_reset_state_flags(xprt);
790 	smp_mb__after_atomic();
791 }
792 
793 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
794 {
795 	xs_sock_reset_connection_flags(xprt);
796 	/* Mark transport as closed and wake up all pending tasks */
797 	xprt_disconnect_done(xprt);
798 }
799 
800 /**
801  * xs_error_report - callback to handle TCP socket state errors
802  * @sk: socket
803  *
804  * Note: we don't call sock_error() since there may be a rpc_task
805  * using the socket, and so we don't want to clear sk->sk_err.
806  */
807 static void xs_error_report(struct sock *sk)
808 {
809 	struct rpc_xprt *xprt;
810 	int err;
811 
812 	read_lock_bh(&sk->sk_callback_lock);
813 	if (!(xprt = xprt_from_sock(sk)))
814 		goto out;
815 
816 	err = -sk->sk_err;
817 	if (err == 0)
818 		goto out;
819 	/* Is this a reset event? */
820 	if (sk->sk_state == TCP_CLOSE)
821 		xs_sock_mark_closed(xprt);
822 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
823 			xprt, -err);
824 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
825 	xprt_wake_pending_tasks(xprt, err);
826  out:
827 	read_unlock_bh(&sk->sk_callback_lock);
828 }
829 
830 static void xs_reset_transport(struct sock_xprt *transport)
831 {
832 	struct socket *sock = transport->sock;
833 	struct sock *sk = transport->inet;
834 	struct rpc_xprt *xprt = &transport->xprt;
835 
836 	if (sk == NULL)
837 		return;
838 
839 	if (atomic_read(&transport->xprt.swapper))
840 		sk_clear_memalloc(sk);
841 
842 	kernel_sock_shutdown(sock, SHUT_RDWR);
843 
844 	mutex_lock(&transport->recv_mutex);
845 	write_lock_bh(&sk->sk_callback_lock);
846 	transport->inet = NULL;
847 	transport->sock = NULL;
848 
849 	sk->sk_user_data = NULL;
850 
851 	xs_restore_old_callbacks(transport, sk);
852 	xprt_clear_connected(xprt);
853 	write_unlock_bh(&sk->sk_callback_lock);
854 	xs_sock_reset_connection_flags(xprt);
855 	mutex_unlock(&transport->recv_mutex);
856 
857 	trace_rpc_socket_close(xprt, sock);
858 	sock_release(sock);
859 }
860 
861 /**
862  * xs_close - close a socket
863  * @xprt: transport
864  *
865  * This is used when all requests are complete; ie, no DRC state remains
866  * on the server we want to save.
867  *
868  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
869  * xs_reset_transport() zeroing the socket from underneath a writer.
870  */
871 static void xs_close(struct rpc_xprt *xprt)
872 {
873 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
874 
875 	dprintk("RPC:       xs_close xprt %p\n", xprt);
876 
877 	xs_reset_transport(transport);
878 	xprt->reestablish_timeout = 0;
879 
880 	xprt_disconnect_done(xprt);
881 }
882 
883 static void xs_inject_disconnect(struct rpc_xprt *xprt)
884 {
885 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
886 		xprt);
887 	xprt_disconnect_done(xprt);
888 }
889 
890 static void xs_xprt_free(struct rpc_xprt *xprt)
891 {
892 	xs_free_peer_addresses(xprt);
893 	xprt_free(xprt);
894 }
895 
896 /**
897  * xs_destroy - prepare to shutdown a transport
898  * @xprt: doomed transport
899  *
900  */
901 static void xs_destroy(struct rpc_xprt *xprt)
902 {
903 	struct sock_xprt *transport = container_of(xprt,
904 			struct sock_xprt, xprt);
905 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
906 
907 	cancel_delayed_work_sync(&transport->connect_worker);
908 	xs_close(xprt);
909 	cancel_work_sync(&transport->recv_worker);
910 	xs_xprt_free(xprt);
911 	module_put(THIS_MODULE);
912 }
913 
914 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
915 {
916 	struct xdr_skb_reader desc = {
917 		.skb		= skb,
918 		.offset		= sizeof(rpc_fraghdr),
919 		.count		= skb->len - sizeof(rpc_fraghdr),
920 	};
921 
922 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
923 		return -1;
924 	if (desc.count)
925 		return -1;
926 	return 0;
927 }
928 
929 /**
930  * xs_local_data_read_skb
931  * @xprt: transport
932  * @sk: socket
933  * @skb: skbuff
934  *
935  * Currently this assumes we can read the whole reply in a single gulp.
936  */
937 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
938 		struct sock *sk,
939 		struct sk_buff *skb)
940 {
941 	struct rpc_task *task;
942 	struct rpc_rqst *rovr;
943 	int repsize, copied;
944 	u32 _xid;
945 	__be32 *xp;
946 
947 	repsize = skb->len - sizeof(rpc_fraghdr);
948 	if (repsize < 4) {
949 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
950 		return;
951 	}
952 
953 	/* Copy the XID from the skb... */
954 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
955 	if (xp == NULL)
956 		return;
957 
958 	/* Look up and lock the request corresponding to the given XID */
959 	spin_lock_bh(&xprt->transport_lock);
960 	rovr = xprt_lookup_rqst(xprt, *xp);
961 	if (!rovr)
962 		goto out_unlock;
963 	task = rovr->rq_task;
964 
965 	copied = rovr->rq_private_buf.buflen;
966 	if (copied > repsize)
967 		copied = repsize;
968 
969 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
970 		dprintk("RPC:       sk_buff copy failed\n");
971 		goto out_unlock;
972 	}
973 
974 	xprt_complete_rqst(task, copied);
975 
976  out_unlock:
977 	spin_unlock_bh(&xprt->transport_lock);
978 }
979 
980 static void xs_local_data_receive(struct sock_xprt *transport)
981 {
982 	struct sk_buff *skb;
983 	struct sock *sk;
984 	int err;
985 
986 	mutex_lock(&transport->recv_mutex);
987 	sk = transport->inet;
988 	if (sk == NULL)
989 		goto out;
990 	for (;;) {
991 		skb = skb_recv_datagram(sk, 0, 1, &err);
992 		if (skb != NULL) {
993 			xs_local_data_read_skb(&transport->xprt, sk, skb);
994 			skb_free_datagram(sk, skb);
995 			continue;
996 		}
997 		if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
998 			break;
999 	}
1000 out:
1001 	mutex_unlock(&transport->recv_mutex);
1002 }
1003 
1004 static void xs_local_data_receive_workfn(struct work_struct *work)
1005 {
1006 	struct sock_xprt *transport =
1007 		container_of(work, struct sock_xprt, recv_worker);
1008 	xs_local_data_receive(transport);
1009 }
1010 
1011 /**
1012  * xs_udp_data_read_skb - receive callback for UDP sockets
1013  * @xprt: transport
1014  * @sk: socket
1015  * @skb: skbuff
1016  *
1017  */
1018 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1019 		struct sock *sk,
1020 		struct sk_buff *skb)
1021 {
1022 	struct rpc_task *task;
1023 	struct rpc_rqst *rovr;
1024 	int repsize, copied;
1025 	u32 _xid;
1026 	__be32 *xp;
1027 
1028 	repsize = skb->len;
1029 	if (repsize < 4) {
1030 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1031 		return;
1032 	}
1033 
1034 	/* Copy the XID from the skb... */
1035 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1036 	if (xp == NULL)
1037 		return;
1038 
1039 	/* Look up and lock the request corresponding to the given XID */
1040 	spin_lock_bh(&xprt->transport_lock);
1041 	rovr = xprt_lookup_rqst(xprt, *xp);
1042 	if (!rovr)
1043 		goto out_unlock;
1044 	task = rovr->rq_task;
1045 
1046 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1047 		copied = repsize;
1048 
1049 	/* Suck it into the iovec, verify checksum if not done by hw. */
1050 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1051 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1052 		goto out_unlock;
1053 	}
1054 
1055 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1056 
1057 	xprt_adjust_cwnd(xprt, task, copied);
1058 	xprt_complete_rqst(task, copied);
1059 
1060  out_unlock:
1061 	spin_unlock_bh(&xprt->transport_lock);
1062 }
1063 
1064 static void xs_udp_data_receive(struct sock_xprt *transport)
1065 {
1066 	struct sk_buff *skb;
1067 	struct sock *sk;
1068 	int err;
1069 
1070 	mutex_lock(&transport->recv_mutex);
1071 	sk = transport->inet;
1072 	if (sk == NULL)
1073 		goto out;
1074 	for (;;) {
1075 		skb = skb_recv_datagram(sk, 0, 1, &err);
1076 		if (skb != NULL) {
1077 			xs_udp_data_read_skb(&transport->xprt, sk, skb);
1078 			skb_free_datagram(sk, skb);
1079 			continue;
1080 		}
1081 		if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1082 			break;
1083 	}
1084 out:
1085 	mutex_unlock(&transport->recv_mutex);
1086 }
1087 
1088 static void xs_udp_data_receive_workfn(struct work_struct *work)
1089 {
1090 	struct sock_xprt *transport =
1091 		container_of(work, struct sock_xprt, recv_worker);
1092 	xs_udp_data_receive(transport);
1093 }
1094 
1095 /**
1096  * xs_data_ready - "data ready" callback for UDP sockets
1097  * @sk: socket with data to read
1098  *
1099  */
1100 static void xs_data_ready(struct sock *sk)
1101 {
1102 	struct rpc_xprt *xprt;
1103 
1104 	read_lock_bh(&sk->sk_callback_lock);
1105 	dprintk("RPC:       xs_data_ready...\n");
1106 	xprt = xprt_from_sock(sk);
1107 	if (xprt != NULL) {
1108 		struct sock_xprt *transport = container_of(xprt,
1109 				struct sock_xprt, xprt);
1110 		transport->old_data_ready(sk);
1111 		/* Any data means we had a useful conversation, so
1112 		 * then we don't need to delay the next reconnect
1113 		 */
1114 		if (xprt->reestablish_timeout)
1115 			xprt->reestablish_timeout = 0;
1116 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1117 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1118 	}
1119 	read_unlock_bh(&sk->sk_callback_lock);
1120 }
1121 
1122 /*
1123  * Helper function to force a TCP close if the server is sending
1124  * junk and/or it has put us in CLOSE_WAIT
1125  */
1126 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1127 {
1128 	xprt_force_disconnect(xprt);
1129 }
1130 
1131 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1132 {
1133 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1134 	size_t len, used;
1135 	char *p;
1136 
1137 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1138 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1139 	used = xdr_skb_read_bits(desc, p, len);
1140 	transport->tcp_offset += used;
1141 	if (used != len)
1142 		return;
1143 
1144 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1145 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1146 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1147 	else
1148 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1149 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1150 
1151 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1152 	transport->tcp_offset = 0;
1153 
1154 	/* Sanity check of the record length */
1155 	if (unlikely(transport->tcp_reclen < 8)) {
1156 		dprintk("RPC:       invalid TCP record fragment length\n");
1157 		xs_tcp_force_close(xprt);
1158 		return;
1159 	}
1160 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1161 			transport->tcp_reclen);
1162 }
1163 
1164 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1165 {
1166 	if (transport->tcp_offset == transport->tcp_reclen) {
1167 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1168 		transport->tcp_offset = 0;
1169 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1170 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1171 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1172 			transport->tcp_copied = 0;
1173 		}
1174 	}
1175 }
1176 
1177 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1178 {
1179 	size_t len, used;
1180 	char *p;
1181 
1182 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1183 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1184 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1185 	used = xdr_skb_read_bits(desc, p, len);
1186 	transport->tcp_offset += used;
1187 	if (used != len)
1188 		return;
1189 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1190 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1191 	transport->tcp_copied = 4;
1192 	dprintk("RPC:       reading %s XID %08x\n",
1193 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1194 							      : "request with",
1195 			ntohl(transport->tcp_xid));
1196 	xs_tcp_check_fraghdr(transport);
1197 }
1198 
1199 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1200 				       struct xdr_skb_reader *desc)
1201 {
1202 	size_t len, used;
1203 	u32 offset;
1204 	char *p;
1205 
1206 	/*
1207 	 * We want transport->tcp_offset to be 8 at the end of this routine
1208 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1209 	 * When this function is called for the first time,
1210 	 * transport->tcp_offset is 4 (after having already read the xid).
1211 	 */
1212 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1213 	len = sizeof(transport->tcp_calldir) - offset;
1214 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1215 	p = ((char *) &transport->tcp_calldir) + offset;
1216 	used = xdr_skb_read_bits(desc, p, len);
1217 	transport->tcp_offset += used;
1218 	if (used != len)
1219 		return;
1220 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1221 	/*
1222 	 * We don't yet have the XDR buffer, so we will write the calldir
1223 	 * out after we get the buffer from the 'struct rpc_rqst'
1224 	 */
1225 	switch (ntohl(transport->tcp_calldir)) {
1226 	case RPC_REPLY:
1227 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1228 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1229 		transport->tcp_flags |= TCP_RPC_REPLY;
1230 		break;
1231 	case RPC_CALL:
1232 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1233 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1234 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1235 		break;
1236 	default:
1237 		dprintk("RPC:       invalid request message type\n");
1238 		xs_tcp_force_close(&transport->xprt);
1239 	}
1240 	xs_tcp_check_fraghdr(transport);
1241 }
1242 
1243 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1244 				     struct xdr_skb_reader *desc,
1245 				     struct rpc_rqst *req)
1246 {
1247 	struct sock_xprt *transport =
1248 				container_of(xprt, struct sock_xprt, xprt);
1249 	struct xdr_buf *rcvbuf;
1250 	size_t len;
1251 	ssize_t r;
1252 
1253 	rcvbuf = &req->rq_private_buf;
1254 
1255 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1256 		/*
1257 		 * Save the RPC direction in the XDR buffer
1258 		 */
1259 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1260 			&transport->tcp_calldir,
1261 			sizeof(transport->tcp_calldir));
1262 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1263 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1264 	}
1265 
1266 	len = desc->count;
1267 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1268 		struct xdr_skb_reader my_desc;
1269 
1270 		len = transport->tcp_reclen - transport->tcp_offset;
1271 		memcpy(&my_desc, desc, sizeof(my_desc));
1272 		my_desc.count = len;
1273 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1274 					  &my_desc, xdr_skb_read_bits);
1275 		desc->count -= r;
1276 		desc->offset += r;
1277 	} else
1278 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1279 					  desc, xdr_skb_read_bits);
1280 
1281 	if (r > 0) {
1282 		transport->tcp_copied += r;
1283 		transport->tcp_offset += r;
1284 	}
1285 	if (r != len) {
1286 		/* Error when copying to the receive buffer,
1287 		 * usually because we weren't able to allocate
1288 		 * additional buffer pages. All we can do now
1289 		 * is turn off TCP_RCV_COPY_DATA, so the request
1290 		 * will not receive any additional updates,
1291 		 * and time out.
1292 		 * Any remaining data from this record will
1293 		 * be discarded.
1294 		 */
1295 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1296 		dprintk("RPC:       XID %08x truncated request\n",
1297 				ntohl(transport->tcp_xid));
1298 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1299 				"tcp_offset = %u, tcp_reclen = %u\n",
1300 				xprt, transport->tcp_copied,
1301 				transport->tcp_offset, transport->tcp_reclen);
1302 		return;
1303 	}
1304 
1305 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1306 			ntohl(transport->tcp_xid), r);
1307 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1308 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1309 			transport->tcp_offset, transport->tcp_reclen);
1310 
1311 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1312 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1313 	else if (transport->tcp_offset == transport->tcp_reclen) {
1314 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1315 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1316 	}
1317 }
1318 
1319 /*
1320  * Finds the request corresponding to the RPC xid and invokes the common
1321  * tcp read code to read the data.
1322  */
1323 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1324 				    struct xdr_skb_reader *desc)
1325 {
1326 	struct sock_xprt *transport =
1327 				container_of(xprt, struct sock_xprt, xprt);
1328 	struct rpc_rqst *req;
1329 
1330 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1331 
1332 	/* Find and lock the request corresponding to this xid */
1333 	spin_lock_bh(&xprt->transport_lock);
1334 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1335 	if (!req) {
1336 		dprintk("RPC:       XID %08x request not found!\n",
1337 				ntohl(transport->tcp_xid));
1338 		spin_unlock_bh(&xprt->transport_lock);
1339 		return -1;
1340 	}
1341 
1342 	xs_tcp_read_common(xprt, desc, req);
1343 
1344 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1345 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1346 
1347 	spin_unlock_bh(&xprt->transport_lock);
1348 	return 0;
1349 }
1350 
1351 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1352 /*
1353  * Obtains an rpc_rqst previously allocated and invokes the common
1354  * tcp read code to read the data.  The result is placed in the callback
1355  * queue.
1356  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1357  * connection and return -1.
1358  */
1359 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1360 				       struct xdr_skb_reader *desc)
1361 {
1362 	struct sock_xprt *transport =
1363 				container_of(xprt, struct sock_xprt, xprt);
1364 	struct rpc_rqst *req;
1365 
1366 	/* Look up and lock the request corresponding to the given XID */
1367 	spin_lock_bh(&xprt->transport_lock);
1368 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1369 	if (req == NULL) {
1370 		spin_unlock_bh(&xprt->transport_lock);
1371 		printk(KERN_WARNING "Callback slot table overflowed\n");
1372 		xprt_force_disconnect(xprt);
1373 		return -1;
1374 	}
1375 
1376 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1377 	xs_tcp_read_common(xprt, desc, req);
1378 
1379 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1380 		xprt_complete_bc_request(req, transport->tcp_copied);
1381 	spin_unlock_bh(&xprt->transport_lock);
1382 
1383 	return 0;
1384 }
1385 
1386 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1387 					struct xdr_skb_reader *desc)
1388 {
1389 	struct sock_xprt *transport =
1390 				container_of(xprt, struct sock_xprt, xprt);
1391 
1392 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1393 		xs_tcp_read_reply(xprt, desc) :
1394 		xs_tcp_read_callback(xprt, desc);
1395 }
1396 
1397 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1398 {
1399 	int ret;
1400 
1401 	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1402 			      SVC_SOCK_ANONYMOUS);
1403 	if (ret < 0)
1404 		return ret;
1405 	return 0;
1406 }
1407 
1408 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1409 {
1410 	return PAGE_SIZE;
1411 }
1412 #else
1413 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1414 					struct xdr_skb_reader *desc)
1415 {
1416 	return xs_tcp_read_reply(xprt, desc);
1417 }
1418 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1419 
1420 /*
1421  * Read data off the transport.  This can be either an RPC_CALL or an
1422  * RPC_REPLY.  Relay the processing to helper functions.
1423  */
1424 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1425 				    struct xdr_skb_reader *desc)
1426 {
1427 	struct sock_xprt *transport =
1428 				container_of(xprt, struct sock_xprt, xprt);
1429 
1430 	if (_xs_tcp_read_data(xprt, desc) == 0)
1431 		xs_tcp_check_fraghdr(transport);
1432 	else {
1433 		/*
1434 		 * The transport_lock protects the request handling.
1435 		 * There's no need to hold it to update the tcp_flags.
1436 		 */
1437 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1438 	}
1439 }
1440 
1441 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1442 {
1443 	size_t len;
1444 
1445 	len = transport->tcp_reclen - transport->tcp_offset;
1446 	if (len > desc->count)
1447 		len = desc->count;
1448 	desc->count -= len;
1449 	desc->offset += len;
1450 	transport->tcp_offset += len;
1451 	dprintk("RPC:       discarded %Zu bytes\n", len);
1452 	xs_tcp_check_fraghdr(transport);
1453 }
1454 
1455 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1456 {
1457 	struct rpc_xprt *xprt = rd_desc->arg.data;
1458 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1459 	struct xdr_skb_reader desc = {
1460 		.skb	= skb,
1461 		.offset	= offset,
1462 		.count	= len,
1463 	};
1464 
1465 	dprintk("RPC:       xs_tcp_data_recv started\n");
1466 	do {
1467 		trace_xs_tcp_data_recv(transport);
1468 		/* Read in a new fragment marker if necessary */
1469 		/* Can we ever really expect to get completely empty fragments? */
1470 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1471 			xs_tcp_read_fraghdr(xprt, &desc);
1472 			continue;
1473 		}
1474 		/* Read in the xid if necessary */
1475 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1476 			xs_tcp_read_xid(transport, &desc);
1477 			continue;
1478 		}
1479 		/* Read in the call/reply flag */
1480 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1481 			xs_tcp_read_calldir(transport, &desc);
1482 			continue;
1483 		}
1484 		/* Read in the request data */
1485 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1486 			xs_tcp_read_data(xprt, &desc);
1487 			continue;
1488 		}
1489 		/* Skip over any trailing bytes on short reads */
1490 		xs_tcp_read_discard(transport, &desc);
1491 	} while (desc.count);
1492 	trace_xs_tcp_data_recv(transport);
1493 	dprintk("RPC:       xs_tcp_data_recv done\n");
1494 	return len - desc.count;
1495 }
1496 
1497 static void xs_tcp_data_receive(struct sock_xprt *transport)
1498 {
1499 	struct rpc_xprt *xprt = &transport->xprt;
1500 	struct sock *sk;
1501 	read_descriptor_t rd_desc = {
1502 		.count = 2*1024*1024,
1503 		.arg.data = xprt,
1504 	};
1505 	unsigned long total = 0;
1506 	int read = 0;
1507 
1508 	mutex_lock(&transport->recv_mutex);
1509 	sk = transport->inet;
1510 	if (sk == NULL)
1511 		goto out;
1512 
1513 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1514 	for (;;) {
1515 		lock_sock(sk);
1516 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1517 		if (read <= 0) {
1518 			clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1519 			release_sock(sk);
1520 			if (!test_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1521 				break;
1522 		} else {
1523 			release_sock(sk);
1524 			total += read;
1525 		}
1526 		rd_desc.count = 65536;
1527 	}
1528 out:
1529 	mutex_unlock(&transport->recv_mutex);
1530 	trace_xs_tcp_data_ready(xprt, read, total);
1531 }
1532 
1533 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1534 {
1535 	struct sock_xprt *transport =
1536 		container_of(work, struct sock_xprt, recv_worker);
1537 	xs_tcp_data_receive(transport);
1538 }
1539 
1540 /**
1541  * xs_tcp_state_change - callback to handle TCP socket state changes
1542  * @sk: socket whose state has changed
1543  *
1544  */
1545 static void xs_tcp_state_change(struct sock *sk)
1546 {
1547 	struct rpc_xprt *xprt;
1548 	struct sock_xprt *transport;
1549 
1550 	read_lock_bh(&sk->sk_callback_lock);
1551 	if (!(xprt = xprt_from_sock(sk)))
1552 		goto out;
1553 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1554 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1555 			sk->sk_state, xprt_connected(xprt),
1556 			sock_flag(sk, SOCK_DEAD),
1557 			sock_flag(sk, SOCK_ZAPPED),
1558 			sk->sk_shutdown);
1559 
1560 	transport = container_of(xprt, struct sock_xprt, xprt);
1561 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1562 	switch (sk->sk_state) {
1563 	case TCP_ESTABLISHED:
1564 		spin_lock(&xprt->transport_lock);
1565 		if (!xprt_test_and_set_connected(xprt)) {
1566 
1567 			/* Reset TCP record info */
1568 			transport->tcp_offset = 0;
1569 			transport->tcp_reclen = 0;
1570 			transport->tcp_copied = 0;
1571 			transport->tcp_flags =
1572 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1573 			xprt->connect_cookie++;
1574 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1575 			xprt_clear_connecting(xprt);
1576 
1577 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1578 		}
1579 		spin_unlock(&xprt->transport_lock);
1580 		break;
1581 	case TCP_FIN_WAIT1:
1582 		/* The client initiated a shutdown of the socket */
1583 		xprt->connect_cookie++;
1584 		xprt->reestablish_timeout = 0;
1585 		set_bit(XPRT_CLOSING, &xprt->state);
1586 		smp_mb__before_atomic();
1587 		clear_bit(XPRT_CONNECTED, &xprt->state);
1588 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1589 		smp_mb__after_atomic();
1590 		break;
1591 	case TCP_CLOSE_WAIT:
1592 		/* The server initiated a shutdown of the socket */
1593 		xprt->connect_cookie++;
1594 		clear_bit(XPRT_CONNECTED, &xprt->state);
1595 		xs_tcp_force_close(xprt);
1596 	case TCP_CLOSING:
1597 		/*
1598 		 * If the server closed down the connection, make sure that
1599 		 * we back off before reconnecting
1600 		 */
1601 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1602 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1603 		break;
1604 	case TCP_LAST_ACK:
1605 		set_bit(XPRT_CLOSING, &xprt->state);
1606 		smp_mb__before_atomic();
1607 		clear_bit(XPRT_CONNECTED, &xprt->state);
1608 		smp_mb__after_atomic();
1609 		break;
1610 	case TCP_CLOSE:
1611 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1612 					&transport->sock_state))
1613 			xprt_clear_connecting(xprt);
1614 		xs_sock_mark_closed(xprt);
1615 	}
1616  out:
1617 	read_unlock_bh(&sk->sk_callback_lock);
1618 }
1619 
1620 static void xs_write_space(struct sock *sk)
1621 {
1622 	struct socket_wq *wq;
1623 	struct rpc_xprt *xprt;
1624 
1625 	if (!sk->sk_socket)
1626 		return;
1627 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1628 
1629 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1630 		return;
1631 	rcu_read_lock();
1632 	wq = rcu_dereference(sk->sk_wq);
1633 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1634 		goto out;
1635 
1636 	xprt_write_space(xprt);
1637 out:
1638 	rcu_read_unlock();
1639 }
1640 
1641 /**
1642  * xs_udp_write_space - callback invoked when socket buffer space
1643  *                             becomes available
1644  * @sk: socket whose state has changed
1645  *
1646  * Called when more output buffer space is available for this socket.
1647  * We try not to wake our writers until they can make "significant"
1648  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1649  * with a bunch of small requests.
1650  */
1651 static void xs_udp_write_space(struct sock *sk)
1652 {
1653 	read_lock_bh(&sk->sk_callback_lock);
1654 
1655 	/* from net/core/sock.c:sock_def_write_space */
1656 	if (sock_writeable(sk))
1657 		xs_write_space(sk);
1658 
1659 	read_unlock_bh(&sk->sk_callback_lock);
1660 }
1661 
1662 /**
1663  * xs_tcp_write_space - callback invoked when socket buffer space
1664  *                             becomes available
1665  * @sk: socket whose state has changed
1666  *
1667  * Called when more output buffer space is available for this socket.
1668  * We try not to wake our writers until they can make "significant"
1669  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1670  * with a bunch of small requests.
1671  */
1672 static void xs_tcp_write_space(struct sock *sk)
1673 {
1674 	read_lock_bh(&sk->sk_callback_lock);
1675 
1676 	/* from net/core/stream.c:sk_stream_write_space */
1677 	if (sk_stream_is_writeable(sk))
1678 		xs_write_space(sk);
1679 
1680 	read_unlock_bh(&sk->sk_callback_lock);
1681 }
1682 
1683 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1684 {
1685 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1686 	struct sock *sk = transport->inet;
1687 
1688 	if (transport->rcvsize) {
1689 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1690 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1691 	}
1692 	if (transport->sndsize) {
1693 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1694 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1695 		sk->sk_write_space(sk);
1696 	}
1697 }
1698 
1699 /**
1700  * xs_udp_set_buffer_size - set send and receive limits
1701  * @xprt: generic transport
1702  * @sndsize: requested size of send buffer, in bytes
1703  * @rcvsize: requested size of receive buffer, in bytes
1704  *
1705  * Set socket send and receive buffer size limits.
1706  */
1707 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1708 {
1709 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1710 
1711 	transport->sndsize = 0;
1712 	if (sndsize)
1713 		transport->sndsize = sndsize + 1024;
1714 	transport->rcvsize = 0;
1715 	if (rcvsize)
1716 		transport->rcvsize = rcvsize + 1024;
1717 
1718 	xs_udp_do_set_buffer_size(xprt);
1719 }
1720 
1721 /**
1722  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1723  * @task: task that timed out
1724  *
1725  * Adjust the congestion window after a retransmit timeout has occurred.
1726  */
1727 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1728 {
1729 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1730 }
1731 
1732 static unsigned short xs_get_random_port(void)
1733 {
1734 	unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
1735 	unsigned short rand = (unsigned short) prandom_u32() % range;
1736 	return rand + xprt_min_resvport;
1737 }
1738 
1739 /**
1740  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1741  * @sock: socket
1742  *
1743  * Note that this function has to be called on all sockets that share the
1744  * same port, and it must be called before binding.
1745  */
1746 static void xs_sock_set_reuseport(struct socket *sock)
1747 {
1748 	int opt = 1;
1749 
1750 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1751 			(char *)&opt, sizeof(opt));
1752 }
1753 
1754 static unsigned short xs_sock_getport(struct socket *sock)
1755 {
1756 	struct sockaddr_storage buf;
1757 	int buflen;
1758 	unsigned short port = 0;
1759 
1760 	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1761 		goto out;
1762 	switch (buf.ss_family) {
1763 	case AF_INET6:
1764 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1765 		break;
1766 	case AF_INET:
1767 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1768 	}
1769 out:
1770 	return port;
1771 }
1772 
1773 /**
1774  * xs_set_port - reset the port number in the remote endpoint address
1775  * @xprt: generic transport
1776  * @port: new port number
1777  *
1778  */
1779 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1780 {
1781 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1782 
1783 	rpc_set_port(xs_addr(xprt), port);
1784 	xs_update_peer_port(xprt);
1785 }
1786 
1787 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1788 {
1789 	if (transport->srcport == 0)
1790 		transport->srcport = xs_sock_getport(sock);
1791 }
1792 
1793 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1794 {
1795 	unsigned short port = transport->srcport;
1796 
1797 	if (port == 0 && transport->xprt.resvport)
1798 		port = xs_get_random_port();
1799 	return port;
1800 }
1801 
1802 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1803 {
1804 	if (transport->srcport != 0)
1805 		transport->srcport = 0;
1806 	if (!transport->xprt.resvport)
1807 		return 0;
1808 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1809 		return xprt_max_resvport;
1810 	return --port;
1811 }
1812 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1813 {
1814 	struct sockaddr_storage myaddr;
1815 	int err, nloop = 0;
1816 	unsigned short port = xs_get_srcport(transport);
1817 	unsigned short last;
1818 
1819 	/*
1820 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1821 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1822 	 * port selection happen implicitly when the socket is used
1823 	 * (for example at connect time).
1824 	 *
1825 	 * This ensures that we can continue to establish TCP
1826 	 * connections even when all local ephemeral ports are already
1827 	 * a part of some TCP connection.  This makes no difference
1828 	 * for UDP sockets, but also doens't harm them.
1829 	 *
1830 	 * If we're asking for any reserved port (i.e. port == 0 &&
1831 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1832 	 * ensure that port is non-zero and we will bind as needed.
1833 	 */
1834 	if (port == 0)
1835 		return 0;
1836 
1837 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1838 	do {
1839 		rpc_set_port((struct sockaddr *)&myaddr, port);
1840 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1841 				transport->xprt.addrlen);
1842 		if (err == 0) {
1843 			transport->srcport = port;
1844 			break;
1845 		}
1846 		last = port;
1847 		port = xs_next_srcport(transport, port);
1848 		if (port > last)
1849 			nloop++;
1850 	} while (err == -EADDRINUSE && nloop != 2);
1851 
1852 	if (myaddr.ss_family == AF_INET)
1853 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1854 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1855 				port, err ? "failed" : "ok", err);
1856 	else
1857 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1858 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1859 				port, err ? "failed" : "ok", err);
1860 	return err;
1861 }
1862 
1863 /*
1864  * We don't support autobind on AF_LOCAL sockets
1865  */
1866 static void xs_local_rpcbind(struct rpc_task *task)
1867 {
1868 	xprt_set_bound(task->tk_xprt);
1869 }
1870 
1871 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1872 {
1873 }
1874 
1875 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1876 static struct lock_class_key xs_key[2];
1877 static struct lock_class_key xs_slock_key[2];
1878 
1879 static inline void xs_reclassify_socketu(struct socket *sock)
1880 {
1881 	struct sock *sk = sock->sk;
1882 
1883 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1884 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1885 }
1886 
1887 static inline void xs_reclassify_socket4(struct socket *sock)
1888 {
1889 	struct sock *sk = sock->sk;
1890 
1891 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1892 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1893 }
1894 
1895 static inline void xs_reclassify_socket6(struct socket *sock)
1896 {
1897 	struct sock *sk = sock->sk;
1898 
1899 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1900 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1901 }
1902 
1903 static inline void xs_reclassify_socket(int family, struct socket *sock)
1904 {
1905 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1906 		return;
1907 
1908 	switch (family) {
1909 	case AF_LOCAL:
1910 		xs_reclassify_socketu(sock);
1911 		break;
1912 	case AF_INET:
1913 		xs_reclassify_socket4(sock);
1914 		break;
1915 	case AF_INET6:
1916 		xs_reclassify_socket6(sock);
1917 		break;
1918 	}
1919 }
1920 #else
1921 static inline void xs_reclassify_socket(int family, struct socket *sock)
1922 {
1923 }
1924 #endif
1925 
1926 static void xs_dummy_setup_socket(struct work_struct *work)
1927 {
1928 }
1929 
1930 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1931 		struct sock_xprt *transport, int family, int type,
1932 		int protocol, bool reuseport)
1933 {
1934 	struct socket *sock;
1935 	int err;
1936 
1937 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1938 	if (err < 0) {
1939 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1940 				protocol, -err);
1941 		goto out;
1942 	}
1943 	xs_reclassify_socket(family, sock);
1944 
1945 	if (reuseport)
1946 		xs_sock_set_reuseport(sock);
1947 
1948 	err = xs_bind(transport, sock);
1949 	if (err) {
1950 		sock_release(sock);
1951 		goto out;
1952 	}
1953 
1954 	return sock;
1955 out:
1956 	return ERR_PTR(err);
1957 }
1958 
1959 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1960 				      struct socket *sock)
1961 {
1962 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1963 									xprt);
1964 
1965 	if (!transport->inet) {
1966 		struct sock *sk = sock->sk;
1967 
1968 		write_lock_bh(&sk->sk_callback_lock);
1969 
1970 		xs_save_old_callbacks(transport, sk);
1971 
1972 		sk->sk_user_data = xprt;
1973 		sk->sk_data_ready = xs_data_ready;
1974 		sk->sk_write_space = xs_udp_write_space;
1975 		sock_set_flag(sk, SOCK_FASYNC);
1976 		sk->sk_error_report = xs_error_report;
1977 		sk->sk_allocation = GFP_NOIO;
1978 
1979 		xprt_clear_connected(xprt);
1980 
1981 		/* Reset to new socket */
1982 		transport->sock = sock;
1983 		transport->inet = sk;
1984 
1985 		write_unlock_bh(&sk->sk_callback_lock);
1986 	}
1987 
1988 	/* Tell the socket layer to start connecting... */
1989 	xprt->stat.connect_count++;
1990 	xprt->stat.connect_start = jiffies;
1991 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1992 }
1993 
1994 /**
1995  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1996  * @transport: socket transport to connect
1997  */
1998 static int xs_local_setup_socket(struct sock_xprt *transport)
1999 {
2000 	struct rpc_xprt *xprt = &transport->xprt;
2001 	struct socket *sock;
2002 	int status = -EIO;
2003 
2004 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
2005 					SOCK_STREAM, 0, &sock, 1);
2006 	if (status < 0) {
2007 		dprintk("RPC:       can't create AF_LOCAL "
2008 			"transport socket (%d).\n", -status);
2009 		goto out;
2010 	}
2011 	xs_reclassify_socket(AF_LOCAL, sock);
2012 
2013 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
2014 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2015 
2016 	status = xs_local_finish_connecting(xprt, sock);
2017 	trace_rpc_socket_connect(xprt, sock, status);
2018 	switch (status) {
2019 	case 0:
2020 		dprintk("RPC:       xprt %p connected to %s\n",
2021 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2022 		xprt_set_connected(xprt);
2023 	case -ENOBUFS:
2024 		break;
2025 	case -ENOENT:
2026 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
2027 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2028 		break;
2029 	case -ECONNREFUSED:
2030 		dprintk("RPC:       xprt %p: connection refused for %s\n",
2031 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2032 		break;
2033 	default:
2034 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2035 				__func__, -status,
2036 				xprt->address_strings[RPC_DISPLAY_ADDR]);
2037 	}
2038 
2039 out:
2040 	xprt_clear_connecting(xprt);
2041 	xprt_wake_pending_tasks(xprt, status);
2042 	return status;
2043 }
2044 
2045 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2046 {
2047 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2048 	int ret;
2049 
2050 	 if (RPC_IS_ASYNC(task)) {
2051 		/*
2052 		 * We want the AF_LOCAL connect to be resolved in the
2053 		 * filesystem namespace of the process making the rpc
2054 		 * call.  Thus we connect synchronously.
2055 		 *
2056 		 * If we want to support asynchronous AF_LOCAL calls,
2057 		 * we'll need to figure out how to pass a namespace to
2058 		 * connect.
2059 		 */
2060 		rpc_exit(task, -ENOTCONN);
2061 		return;
2062 	}
2063 	ret = xs_local_setup_socket(transport);
2064 	if (ret && !RPC_IS_SOFTCONN(task))
2065 		msleep_interruptible(15000);
2066 }
2067 
2068 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2069 /*
2070  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2071  * know that we have exclusive access to the socket), to guard against
2072  * races with xs_reset_transport.
2073  */
2074 static void xs_set_memalloc(struct rpc_xprt *xprt)
2075 {
2076 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2077 			xprt);
2078 
2079 	/*
2080 	 * If there's no sock, then we have nothing to set. The
2081 	 * reconnecting process will get it for us.
2082 	 */
2083 	if (!transport->inet)
2084 		return;
2085 	if (atomic_read(&xprt->swapper))
2086 		sk_set_memalloc(transport->inet);
2087 }
2088 
2089 /**
2090  * xs_enable_swap - Tag this transport as being used for swap.
2091  * @xprt: transport to tag
2092  *
2093  * Take a reference to this transport on behalf of the rpc_clnt, and
2094  * optionally mark it for swapping if it wasn't already.
2095  */
2096 static int
2097 xs_enable_swap(struct rpc_xprt *xprt)
2098 {
2099 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2100 
2101 	if (atomic_inc_return(&xprt->swapper) != 1)
2102 		return 0;
2103 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2104 		return -ERESTARTSYS;
2105 	if (xs->inet)
2106 		sk_set_memalloc(xs->inet);
2107 	xprt_release_xprt(xprt, NULL);
2108 	return 0;
2109 }
2110 
2111 /**
2112  * xs_disable_swap - Untag this transport as being used for swap.
2113  * @xprt: transport to tag
2114  *
2115  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2116  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2117  */
2118 static void
2119 xs_disable_swap(struct rpc_xprt *xprt)
2120 {
2121 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2122 
2123 	if (!atomic_dec_and_test(&xprt->swapper))
2124 		return;
2125 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2126 		return;
2127 	if (xs->inet)
2128 		sk_clear_memalloc(xs->inet);
2129 	xprt_release_xprt(xprt, NULL);
2130 }
2131 #else
2132 static void xs_set_memalloc(struct rpc_xprt *xprt)
2133 {
2134 }
2135 
2136 static int
2137 xs_enable_swap(struct rpc_xprt *xprt)
2138 {
2139 	return -EINVAL;
2140 }
2141 
2142 static void
2143 xs_disable_swap(struct rpc_xprt *xprt)
2144 {
2145 }
2146 #endif
2147 
2148 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2149 {
2150 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2151 
2152 	if (!transport->inet) {
2153 		struct sock *sk = sock->sk;
2154 
2155 		write_lock_bh(&sk->sk_callback_lock);
2156 
2157 		xs_save_old_callbacks(transport, sk);
2158 
2159 		sk->sk_user_data = xprt;
2160 		sk->sk_data_ready = xs_data_ready;
2161 		sk->sk_write_space = xs_udp_write_space;
2162 		sock_set_flag(sk, SOCK_FASYNC);
2163 		sk->sk_allocation = GFP_NOIO;
2164 
2165 		xprt_set_connected(xprt);
2166 
2167 		/* Reset to new socket */
2168 		transport->sock = sock;
2169 		transport->inet = sk;
2170 
2171 		xs_set_memalloc(xprt);
2172 
2173 		write_unlock_bh(&sk->sk_callback_lock);
2174 	}
2175 	xs_udp_do_set_buffer_size(xprt);
2176 }
2177 
2178 static void xs_udp_setup_socket(struct work_struct *work)
2179 {
2180 	struct sock_xprt *transport =
2181 		container_of(work, struct sock_xprt, connect_worker.work);
2182 	struct rpc_xprt *xprt = &transport->xprt;
2183 	struct socket *sock = transport->sock;
2184 	int status = -EIO;
2185 
2186 	sock = xs_create_sock(xprt, transport,
2187 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2188 			IPPROTO_UDP, false);
2189 	if (IS_ERR(sock))
2190 		goto out;
2191 
2192 	dprintk("RPC:       worker connecting xprt %p via %s to "
2193 				"%s (port %s)\n", xprt,
2194 			xprt->address_strings[RPC_DISPLAY_PROTO],
2195 			xprt->address_strings[RPC_DISPLAY_ADDR],
2196 			xprt->address_strings[RPC_DISPLAY_PORT]);
2197 
2198 	xs_udp_finish_connecting(xprt, sock);
2199 	trace_rpc_socket_connect(xprt, sock, 0);
2200 	status = 0;
2201 out:
2202 	xprt_unlock_connect(xprt, transport);
2203 	xprt_clear_connecting(xprt);
2204 	xprt_wake_pending_tasks(xprt, status);
2205 }
2206 
2207 /**
2208  * xs_tcp_shutdown - gracefully shut down a TCP socket
2209  * @xprt: transport
2210  *
2211  * Initiates a graceful shutdown of the TCP socket by calling the
2212  * equivalent of shutdown(SHUT_RDWR);
2213  */
2214 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2215 {
2216 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2217 	struct socket *sock = transport->sock;
2218 
2219 	if (sock == NULL)
2220 		return;
2221 	if (xprt_connected(xprt)) {
2222 		kernel_sock_shutdown(sock, SHUT_RDWR);
2223 		trace_rpc_socket_shutdown(xprt, sock);
2224 	} else
2225 		xs_reset_transport(transport);
2226 }
2227 
2228 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2229 {
2230 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2231 	int ret = -ENOTCONN;
2232 
2233 	if (!transport->inet) {
2234 		struct sock *sk = sock->sk;
2235 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2236 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2237 		unsigned int opt_on = 1;
2238 		unsigned int timeo;
2239 
2240 		/* TCP Keepalive options */
2241 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2242 				(char *)&opt_on, sizeof(opt_on));
2243 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2244 				(char *)&keepidle, sizeof(keepidle));
2245 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2246 				(char *)&keepidle, sizeof(keepidle));
2247 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2248 				(char *)&keepcnt, sizeof(keepcnt));
2249 
2250 		/* TCP user timeout (see RFC5482) */
2251 		timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2252 			(xprt->timeout->to_retries + 1);
2253 		kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2254 				(char *)&timeo, sizeof(timeo));
2255 
2256 		write_lock_bh(&sk->sk_callback_lock);
2257 
2258 		xs_save_old_callbacks(transport, sk);
2259 
2260 		sk->sk_user_data = xprt;
2261 		sk->sk_data_ready = xs_data_ready;
2262 		sk->sk_state_change = xs_tcp_state_change;
2263 		sk->sk_write_space = xs_tcp_write_space;
2264 		sock_set_flag(sk, SOCK_FASYNC);
2265 		sk->sk_error_report = xs_error_report;
2266 		sk->sk_allocation = GFP_NOIO;
2267 
2268 		/* socket options */
2269 		sock_reset_flag(sk, SOCK_LINGER);
2270 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2271 
2272 		xprt_clear_connected(xprt);
2273 
2274 		/* Reset to new socket */
2275 		transport->sock = sock;
2276 		transport->inet = sk;
2277 
2278 		write_unlock_bh(&sk->sk_callback_lock);
2279 	}
2280 
2281 	if (!xprt_bound(xprt))
2282 		goto out;
2283 
2284 	xs_set_memalloc(xprt);
2285 
2286 	/* Tell the socket layer to start connecting... */
2287 	xprt->stat.connect_count++;
2288 	xprt->stat.connect_start = jiffies;
2289 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2290 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2291 	switch (ret) {
2292 	case 0:
2293 		xs_set_srcport(transport, sock);
2294 	case -EINPROGRESS:
2295 		/* SYN_SENT! */
2296 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2297 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2298 	}
2299 out:
2300 	return ret;
2301 }
2302 
2303 /**
2304  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2305  *
2306  * Invoked by a work queue tasklet.
2307  */
2308 static void xs_tcp_setup_socket(struct work_struct *work)
2309 {
2310 	struct sock_xprt *transport =
2311 		container_of(work, struct sock_xprt, connect_worker.work);
2312 	struct socket *sock = transport->sock;
2313 	struct rpc_xprt *xprt = &transport->xprt;
2314 	int status = -EIO;
2315 
2316 	if (!sock) {
2317 		sock = xs_create_sock(xprt, transport,
2318 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2319 				IPPROTO_TCP, true);
2320 		if (IS_ERR(sock)) {
2321 			status = PTR_ERR(sock);
2322 			goto out;
2323 		}
2324 	}
2325 
2326 	dprintk("RPC:       worker connecting xprt %p via %s to "
2327 				"%s (port %s)\n", xprt,
2328 			xprt->address_strings[RPC_DISPLAY_PROTO],
2329 			xprt->address_strings[RPC_DISPLAY_ADDR],
2330 			xprt->address_strings[RPC_DISPLAY_PORT]);
2331 
2332 	status = xs_tcp_finish_connecting(xprt, sock);
2333 	trace_rpc_socket_connect(xprt, sock, status);
2334 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2335 			xprt, -status, xprt_connected(xprt),
2336 			sock->sk->sk_state);
2337 	switch (status) {
2338 	default:
2339 		printk("%s: connect returned unhandled error %d\n",
2340 			__func__, status);
2341 	case -EADDRNOTAVAIL:
2342 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2343 		 * and retry
2344 		 */
2345 		xs_tcp_force_close(xprt);
2346 		break;
2347 	case 0:
2348 	case -EINPROGRESS:
2349 	case -EALREADY:
2350 		xprt_unlock_connect(xprt, transport);
2351 		return;
2352 	case -EINVAL:
2353 		/* Happens, for instance, if the user specified a link
2354 		 * local IPv6 address without a scope-id.
2355 		 */
2356 	case -ECONNREFUSED:
2357 	case -ECONNRESET:
2358 	case -ENETUNREACH:
2359 	case -EADDRINUSE:
2360 	case -ENOBUFS:
2361 		/* retry with existing socket, after a delay */
2362 		xs_tcp_force_close(xprt);
2363 		goto out;
2364 	}
2365 	status = -EAGAIN;
2366 out:
2367 	xprt_unlock_connect(xprt, transport);
2368 	xprt_clear_connecting(xprt);
2369 	xprt_wake_pending_tasks(xprt, status);
2370 }
2371 
2372 /**
2373  * xs_connect - connect a socket to a remote endpoint
2374  * @xprt: pointer to transport structure
2375  * @task: address of RPC task that manages state of connect request
2376  *
2377  * TCP: If the remote end dropped the connection, delay reconnecting.
2378  *
2379  * UDP socket connects are synchronous, but we use a work queue anyway
2380  * to guarantee that even unprivileged user processes can set up a
2381  * socket on a privileged port.
2382  *
2383  * If a UDP socket connect fails, the delay behavior here prevents
2384  * retry floods (hard mounts).
2385  */
2386 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2387 {
2388 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2389 
2390 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2391 
2392 	if (transport->sock != NULL) {
2393 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2394 				"seconds\n",
2395 				xprt, xprt->reestablish_timeout / HZ);
2396 
2397 		/* Start by resetting any existing state */
2398 		xs_reset_transport(transport);
2399 
2400 		queue_delayed_work(xprtiod_workqueue,
2401 				   &transport->connect_worker,
2402 				   xprt->reestablish_timeout);
2403 		xprt->reestablish_timeout <<= 1;
2404 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2405 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2406 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2407 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2408 	} else {
2409 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2410 		queue_delayed_work(xprtiod_workqueue,
2411 				   &transport->connect_worker, 0);
2412 	}
2413 }
2414 
2415 /**
2416  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2417  * @xprt: rpc_xprt struct containing statistics
2418  * @seq: output file
2419  *
2420  */
2421 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2422 {
2423 	long idle_time = 0;
2424 
2425 	if (xprt_connected(xprt))
2426 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2427 
2428 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2429 			"%llu %llu %lu %llu %llu\n",
2430 			xprt->stat.bind_count,
2431 			xprt->stat.connect_count,
2432 			xprt->stat.connect_time,
2433 			idle_time,
2434 			xprt->stat.sends,
2435 			xprt->stat.recvs,
2436 			xprt->stat.bad_xids,
2437 			xprt->stat.req_u,
2438 			xprt->stat.bklog_u,
2439 			xprt->stat.max_slots,
2440 			xprt->stat.sending_u,
2441 			xprt->stat.pending_u);
2442 }
2443 
2444 /**
2445  * xs_udp_print_stats - display UDP socket-specifc stats
2446  * @xprt: rpc_xprt struct containing statistics
2447  * @seq: output file
2448  *
2449  */
2450 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2451 {
2452 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2453 
2454 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2455 			"%lu %llu %llu\n",
2456 			transport->srcport,
2457 			xprt->stat.bind_count,
2458 			xprt->stat.sends,
2459 			xprt->stat.recvs,
2460 			xprt->stat.bad_xids,
2461 			xprt->stat.req_u,
2462 			xprt->stat.bklog_u,
2463 			xprt->stat.max_slots,
2464 			xprt->stat.sending_u,
2465 			xprt->stat.pending_u);
2466 }
2467 
2468 /**
2469  * xs_tcp_print_stats - display TCP socket-specifc stats
2470  * @xprt: rpc_xprt struct containing statistics
2471  * @seq: output file
2472  *
2473  */
2474 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2475 {
2476 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2477 	long idle_time = 0;
2478 
2479 	if (xprt_connected(xprt))
2480 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2481 
2482 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2483 			"%llu %llu %lu %llu %llu\n",
2484 			transport->srcport,
2485 			xprt->stat.bind_count,
2486 			xprt->stat.connect_count,
2487 			xprt->stat.connect_time,
2488 			idle_time,
2489 			xprt->stat.sends,
2490 			xprt->stat.recvs,
2491 			xprt->stat.bad_xids,
2492 			xprt->stat.req_u,
2493 			xprt->stat.bklog_u,
2494 			xprt->stat.max_slots,
2495 			xprt->stat.sending_u,
2496 			xprt->stat.pending_u);
2497 }
2498 
2499 /*
2500  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2501  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2502  * to use the server side send routines.
2503  */
2504 static void *bc_malloc(struct rpc_task *task, size_t size)
2505 {
2506 	struct page *page;
2507 	struct rpc_buffer *buf;
2508 
2509 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2510 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2511 		return NULL;
2512 
2513 	page = alloc_page(GFP_KERNEL);
2514 	if (!page)
2515 		return NULL;
2516 
2517 	buf = page_address(page);
2518 	buf->len = PAGE_SIZE;
2519 
2520 	return buf->data;
2521 }
2522 
2523 /*
2524  * Free the space allocated in the bc_alloc routine
2525  */
2526 static void bc_free(void *buffer)
2527 {
2528 	struct rpc_buffer *buf;
2529 
2530 	if (!buffer)
2531 		return;
2532 
2533 	buf = container_of(buffer, struct rpc_buffer, data);
2534 	free_page((unsigned long)buf);
2535 }
2536 
2537 /*
2538  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2539  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2540  */
2541 static int bc_sendto(struct rpc_rqst *req)
2542 {
2543 	int len;
2544 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2545 	struct rpc_xprt *xprt = req->rq_xprt;
2546 	struct sock_xprt *transport =
2547 				container_of(xprt, struct sock_xprt, xprt);
2548 	struct socket *sock = transport->sock;
2549 	unsigned long headoff;
2550 	unsigned long tailoff;
2551 
2552 	xs_encode_stream_record_marker(xbufp);
2553 
2554 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2555 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2556 	len = svc_send_common(sock, xbufp,
2557 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2558 			      xbufp->tail[0].iov_base, tailoff);
2559 
2560 	if (len != xbufp->len) {
2561 		printk(KERN_NOTICE "Error sending entire callback!\n");
2562 		len = -EAGAIN;
2563 	}
2564 
2565 	return len;
2566 }
2567 
2568 /*
2569  * The send routine. Borrows from svc_send
2570  */
2571 static int bc_send_request(struct rpc_task *task)
2572 {
2573 	struct rpc_rqst *req = task->tk_rqstp;
2574 	struct svc_xprt	*xprt;
2575 	int len;
2576 
2577 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2578 	/*
2579 	 * Get the server socket associated with this callback xprt
2580 	 */
2581 	xprt = req->rq_xprt->bc_xprt;
2582 
2583 	/*
2584 	 * Grab the mutex to serialize data as the connection is shared
2585 	 * with the fore channel
2586 	 */
2587 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2588 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2589 		if (!mutex_trylock(&xprt->xpt_mutex))
2590 			return -EAGAIN;
2591 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2592 	}
2593 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2594 		len = -ENOTCONN;
2595 	else
2596 		len = bc_sendto(req);
2597 	mutex_unlock(&xprt->xpt_mutex);
2598 
2599 	if (len > 0)
2600 		len = 0;
2601 
2602 	return len;
2603 }
2604 
2605 /*
2606  * The close routine. Since this is client initiated, we do nothing
2607  */
2608 
2609 static void bc_close(struct rpc_xprt *xprt)
2610 {
2611 }
2612 
2613 /*
2614  * The xprt destroy routine. Again, because this connection is client
2615  * initiated, we do nothing
2616  */
2617 
2618 static void bc_destroy(struct rpc_xprt *xprt)
2619 {
2620 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2621 
2622 	xs_xprt_free(xprt);
2623 	module_put(THIS_MODULE);
2624 }
2625 
2626 static struct rpc_xprt_ops xs_local_ops = {
2627 	.reserve_xprt		= xprt_reserve_xprt,
2628 	.release_xprt		= xs_tcp_release_xprt,
2629 	.alloc_slot		= xprt_alloc_slot,
2630 	.rpcbind		= xs_local_rpcbind,
2631 	.set_port		= xs_local_set_port,
2632 	.connect		= xs_local_connect,
2633 	.buf_alloc		= rpc_malloc,
2634 	.buf_free		= rpc_free,
2635 	.send_request		= xs_local_send_request,
2636 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2637 	.close			= xs_close,
2638 	.destroy		= xs_destroy,
2639 	.print_stats		= xs_local_print_stats,
2640 	.enable_swap		= xs_enable_swap,
2641 	.disable_swap		= xs_disable_swap,
2642 };
2643 
2644 static struct rpc_xprt_ops xs_udp_ops = {
2645 	.set_buffer_size	= xs_udp_set_buffer_size,
2646 	.reserve_xprt		= xprt_reserve_xprt_cong,
2647 	.release_xprt		= xprt_release_xprt_cong,
2648 	.alloc_slot		= xprt_alloc_slot,
2649 	.rpcbind		= rpcb_getport_async,
2650 	.set_port		= xs_set_port,
2651 	.connect		= xs_connect,
2652 	.buf_alloc		= rpc_malloc,
2653 	.buf_free		= rpc_free,
2654 	.send_request		= xs_udp_send_request,
2655 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2656 	.timer			= xs_udp_timer,
2657 	.release_request	= xprt_release_rqst_cong,
2658 	.close			= xs_close,
2659 	.destroy		= xs_destroy,
2660 	.print_stats		= xs_udp_print_stats,
2661 	.enable_swap		= xs_enable_swap,
2662 	.disable_swap		= xs_disable_swap,
2663 	.inject_disconnect	= xs_inject_disconnect,
2664 };
2665 
2666 static struct rpc_xprt_ops xs_tcp_ops = {
2667 	.reserve_xprt		= xprt_reserve_xprt,
2668 	.release_xprt		= xs_tcp_release_xprt,
2669 	.alloc_slot		= xprt_lock_and_alloc_slot,
2670 	.rpcbind		= rpcb_getport_async,
2671 	.set_port		= xs_set_port,
2672 	.connect		= xs_connect,
2673 	.buf_alloc		= rpc_malloc,
2674 	.buf_free		= rpc_free,
2675 	.send_request		= xs_tcp_send_request,
2676 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2677 	.close			= xs_tcp_shutdown,
2678 	.destroy		= xs_destroy,
2679 	.print_stats		= xs_tcp_print_stats,
2680 	.enable_swap		= xs_enable_swap,
2681 	.disable_swap		= xs_disable_swap,
2682 	.inject_disconnect	= xs_inject_disconnect,
2683 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2684 	.bc_setup		= xprt_setup_bc,
2685 	.bc_up			= xs_tcp_bc_up,
2686 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2687 	.bc_free_rqst		= xprt_free_bc_rqst,
2688 	.bc_destroy		= xprt_destroy_bc,
2689 #endif
2690 };
2691 
2692 /*
2693  * The rpc_xprt_ops for the server backchannel
2694  */
2695 
2696 static struct rpc_xprt_ops bc_tcp_ops = {
2697 	.reserve_xprt		= xprt_reserve_xprt,
2698 	.release_xprt		= xprt_release_xprt,
2699 	.alloc_slot		= xprt_alloc_slot,
2700 	.buf_alloc		= bc_malloc,
2701 	.buf_free		= bc_free,
2702 	.send_request		= bc_send_request,
2703 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2704 	.close			= bc_close,
2705 	.destroy		= bc_destroy,
2706 	.print_stats		= xs_tcp_print_stats,
2707 	.enable_swap		= xs_enable_swap,
2708 	.disable_swap		= xs_disable_swap,
2709 	.inject_disconnect	= xs_inject_disconnect,
2710 };
2711 
2712 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2713 {
2714 	static const struct sockaddr_in sin = {
2715 		.sin_family		= AF_INET,
2716 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2717 	};
2718 	static const struct sockaddr_in6 sin6 = {
2719 		.sin6_family		= AF_INET6,
2720 		.sin6_addr		= IN6ADDR_ANY_INIT,
2721 	};
2722 
2723 	switch (family) {
2724 	case AF_LOCAL:
2725 		break;
2726 	case AF_INET:
2727 		memcpy(sap, &sin, sizeof(sin));
2728 		break;
2729 	case AF_INET6:
2730 		memcpy(sap, &sin6, sizeof(sin6));
2731 		break;
2732 	default:
2733 		dprintk("RPC:       %s: Bad address family\n", __func__);
2734 		return -EAFNOSUPPORT;
2735 	}
2736 	return 0;
2737 }
2738 
2739 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2740 				      unsigned int slot_table_size,
2741 				      unsigned int max_slot_table_size)
2742 {
2743 	struct rpc_xprt *xprt;
2744 	struct sock_xprt *new;
2745 
2746 	if (args->addrlen > sizeof(xprt->addr)) {
2747 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2748 		return ERR_PTR(-EBADF);
2749 	}
2750 
2751 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2752 			max_slot_table_size);
2753 	if (xprt == NULL) {
2754 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2755 				"rpc_xprt\n");
2756 		return ERR_PTR(-ENOMEM);
2757 	}
2758 
2759 	new = container_of(xprt, struct sock_xprt, xprt);
2760 	mutex_init(&new->recv_mutex);
2761 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2762 	xprt->addrlen = args->addrlen;
2763 	if (args->srcaddr)
2764 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2765 	else {
2766 		int err;
2767 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2768 					(struct sockaddr *)&new->srcaddr);
2769 		if (err != 0) {
2770 			xprt_free(xprt);
2771 			return ERR_PTR(err);
2772 		}
2773 	}
2774 
2775 	return xprt;
2776 }
2777 
2778 static const struct rpc_timeout xs_local_default_timeout = {
2779 	.to_initval = 10 * HZ,
2780 	.to_maxval = 10 * HZ,
2781 	.to_retries = 2,
2782 };
2783 
2784 /**
2785  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2786  * @args: rpc transport creation arguments
2787  *
2788  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2789  */
2790 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2791 {
2792 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2793 	struct sock_xprt *transport;
2794 	struct rpc_xprt *xprt;
2795 	struct rpc_xprt *ret;
2796 
2797 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2798 			xprt_max_tcp_slot_table_entries);
2799 	if (IS_ERR(xprt))
2800 		return xprt;
2801 	transport = container_of(xprt, struct sock_xprt, xprt);
2802 
2803 	xprt->prot = 0;
2804 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2805 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2806 
2807 	xprt->bind_timeout = XS_BIND_TO;
2808 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2809 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2810 
2811 	xprt->ops = &xs_local_ops;
2812 	xprt->timeout = &xs_local_default_timeout;
2813 
2814 	INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2815 	INIT_DELAYED_WORK(&transport->connect_worker,
2816 			xs_dummy_setup_socket);
2817 
2818 	switch (sun->sun_family) {
2819 	case AF_LOCAL:
2820 		if (sun->sun_path[0] != '/') {
2821 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2822 					sun->sun_path);
2823 			ret = ERR_PTR(-EINVAL);
2824 			goto out_err;
2825 		}
2826 		xprt_set_bound(xprt);
2827 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2828 		ret = ERR_PTR(xs_local_setup_socket(transport));
2829 		if (ret)
2830 			goto out_err;
2831 		break;
2832 	default:
2833 		ret = ERR_PTR(-EAFNOSUPPORT);
2834 		goto out_err;
2835 	}
2836 
2837 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2838 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2839 
2840 	if (try_module_get(THIS_MODULE))
2841 		return xprt;
2842 	ret = ERR_PTR(-EINVAL);
2843 out_err:
2844 	xs_xprt_free(xprt);
2845 	return ret;
2846 }
2847 
2848 static const struct rpc_timeout xs_udp_default_timeout = {
2849 	.to_initval = 5 * HZ,
2850 	.to_maxval = 30 * HZ,
2851 	.to_increment = 5 * HZ,
2852 	.to_retries = 5,
2853 };
2854 
2855 /**
2856  * xs_setup_udp - Set up transport to use a UDP socket
2857  * @args: rpc transport creation arguments
2858  *
2859  */
2860 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2861 {
2862 	struct sockaddr *addr = args->dstaddr;
2863 	struct rpc_xprt *xprt;
2864 	struct sock_xprt *transport;
2865 	struct rpc_xprt *ret;
2866 
2867 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2868 			xprt_udp_slot_table_entries);
2869 	if (IS_ERR(xprt))
2870 		return xprt;
2871 	transport = container_of(xprt, struct sock_xprt, xprt);
2872 
2873 	xprt->prot = IPPROTO_UDP;
2874 	xprt->tsh_size = 0;
2875 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2876 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2877 
2878 	xprt->bind_timeout = XS_BIND_TO;
2879 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2880 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2881 
2882 	xprt->ops = &xs_udp_ops;
2883 
2884 	xprt->timeout = &xs_udp_default_timeout;
2885 
2886 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2887 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2888 
2889 	switch (addr->sa_family) {
2890 	case AF_INET:
2891 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2892 			xprt_set_bound(xprt);
2893 
2894 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2895 		break;
2896 	case AF_INET6:
2897 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2898 			xprt_set_bound(xprt);
2899 
2900 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2901 		break;
2902 	default:
2903 		ret = ERR_PTR(-EAFNOSUPPORT);
2904 		goto out_err;
2905 	}
2906 
2907 	if (xprt_bound(xprt))
2908 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2909 				xprt->address_strings[RPC_DISPLAY_ADDR],
2910 				xprt->address_strings[RPC_DISPLAY_PORT],
2911 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2912 	else
2913 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2914 				xprt->address_strings[RPC_DISPLAY_ADDR],
2915 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2916 
2917 	if (try_module_get(THIS_MODULE))
2918 		return xprt;
2919 	ret = ERR_PTR(-EINVAL);
2920 out_err:
2921 	xs_xprt_free(xprt);
2922 	return ret;
2923 }
2924 
2925 static const struct rpc_timeout xs_tcp_default_timeout = {
2926 	.to_initval = 60 * HZ,
2927 	.to_maxval = 60 * HZ,
2928 	.to_retries = 2,
2929 };
2930 
2931 /**
2932  * xs_setup_tcp - Set up transport to use a TCP socket
2933  * @args: rpc transport creation arguments
2934  *
2935  */
2936 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2937 {
2938 	struct sockaddr *addr = args->dstaddr;
2939 	struct rpc_xprt *xprt;
2940 	struct sock_xprt *transport;
2941 	struct rpc_xprt *ret;
2942 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2943 
2944 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2945 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2946 
2947 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2948 			max_slot_table_size);
2949 	if (IS_ERR(xprt))
2950 		return xprt;
2951 	transport = container_of(xprt, struct sock_xprt, xprt);
2952 
2953 	xprt->prot = IPPROTO_TCP;
2954 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2955 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2956 
2957 	xprt->bind_timeout = XS_BIND_TO;
2958 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2959 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2960 
2961 	xprt->ops = &xs_tcp_ops;
2962 	xprt->timeout = &xs_tcp_default_timeout;
2963 
2964 	INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
2965 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2966 
2967 	switch (addr->sa_family) {
2968 	case AF_INET:
2969 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2970 			xprt_set_bound(xprt);
2971 
2972 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2973 		break;
2974 	case AF_INET6:
2975 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2976 			xprt_set_bound(xprt);
2977 
2978 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2979 		break;
2980 	default:
2981 		ret = ERR_PTR(-EAFNOSUPPORT);
2982 		goto out_err;
2983 	}
2984 
2985 	if (xprt_bound(xprt))
2986 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2987 				xprt->address_strings[RPC_DISPLAY_ADDR],
2988 				xprt->address_strings[RPC_DISPLAY_PORT],
2989 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2990 	else
2991 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2992 				xprt->address_strings[RPC_DISPLAY_ADDR],
2993 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2994 
2995 	if (try_module_get(THIS_MODULE))
2996 		return xprt;
2997 	ret = ERR_PTR(-EINVAL);
2998 out_err:
2999 	xs_xprt_free(xprt);
3000 	return ret;
3001 }
3002 
3003 /**
3004  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3005  * @args: rpc transport creation arguments
3006  *
3007  */
3008 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3009 {
3010 	struct sockaddr *addr = args->dstaddr;
3011 	struct rpc_xprt *xprt;
3012 	struct sock_xprt *transport;
3013 	struct svc_sock *bc_sock;
3014 	struct rpc_xprt *ret;
3015 
3016 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3017 			xprt_tcp_slot_table_entries);
3018 	if (IS_ERR(xprt))
3019 		return xprt;
3020 	transport = container_of(xprt, struct sock_xprt, xprt);
3021 
3022 	xprt->prot = IPPROTO_TCP;
3023 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3024 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3025 	xprt->timeout = &xs_tcp_default_timeout;
3026 
3027 	/* backchannel */
3028 	xprt_set_bound(xprt);
3029 	xprt->bind_timeout = 0;
3030 	xprt->reestablish_timeout = 0;
3031 	xprt->idle_timeout = 0;
3032 
3033 	xprt->ops = &bc_tcp_ops;
3034 
3035 	switch (addr->sa_family) {
3036 	case AF_INET:
3037 		xs_format_peer_addresses(xprt, "tcp",
3038 					 RPCBIND_NETID_TCP);
3039 		break;
3040 	case AF_INET6:
3041 		xs_format_peer_addresses(xprt, "tcp",
3042 				   RPCBIND_NETID_TCP6);
3043 		break;
3044 	default:
3045 		ret = ERR_PTR(-EAFNOSUPPORT);
3046 		goto out_err;
3047 	}
3048 
3049 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3050 			xprt->address_strings[RPC_DISPLAY_ADDR],
3051 			xprt->address_strings[RPC_DISPLAY_PORT],
3052 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3053 
3054 	/*
3055 	 * Once we've associated a backchannel xprt with a connection,
3056 	 * we want to keep it around as long as the connection lasts,
3057 	 * in case we need to start using it for a backchannel again;
3058 	 * this reference won't be dropped until bc_xprt is destroyed.
3059 	 */
3060 	xprt_get(xprt);
3061 	args->bc_xprt->xpt_bc_xprt = xprt;
3062 	xprt->bc_xprt = args->bc_xprt;
3063 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3064 	transport->sock = bc_sock->sk_sock;
3065 	transport->inet = bc_sock->sk_sk;
3066 
3067 	/*
3068 	 * Since we don't want connections for the backchannel, we set
3069 	 * the xprt status to connected
3070 	 */
3071 	xprt_set_connected(xprt);
3072 
3073 	if (try_module_get(THIS_MODULE))
3074 		return xprt;
3075 
3076 	args->bc_xprt->xpt_bc_xprt = NULL;
3077 	args->bc_xprt->xpt_bc_xps = NULL;
3078 	xprt_put(xprt);
3079 	ret = ERR_PTR(-EINVAL);
3080 out_err:
3081 	xs_xprt_free(xprt);
3082 	return ret;
3083 }
3084 
3085 static struct xprt_class	xs_local_transport = {
3086 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3087 	.name		= "named UNIX socket",
3088 	.owner		= THIS_MODULE,
3089 	.ident		= XPRT_TRANSPORT_LOCAL,
3090 	.setup		= xs_setup_local,
3091 };
3092 
3093 static struct xprt_class	xs_udp_transport = {
3094 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3095 	.name		= "udp",
3096 	.owner		= THIS_MODULE,
3097 	.ident		= XPRT_TRANSPORT_UDP,
3098 	.setup		= xs_setup_udp,
3099 };
3100 
3101 static struct xprt_class	xs_tcp_transport = {
3102 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3103 	.name		= "tcp",
3104 	.owner		= THIS_MODULE,
3105 	.ident		= XPRT_TRANSPORT_TCP,
3106 	.setup		= xs_setup_tcp,
3107 };
3108 
3109 static struct xprt_class	xs_bc_tcp_transport = {
3110 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3111 	.name		= "tcp NFSv4.1 backchannel",
3112 	.owner		= THIS_MODULE,
3113 	.ident		= XPRT_TRANSPORT_BC_TCP,
3114 	.setup		= xs_setup_bc_tcp,
3115 };
3116 
3117 /**
3118  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3119  *
3120  */
3121 int init_socket_xprt(void)
3122 {
3123 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3124 	if (!sunrpc_table_header)
3125 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3126 #endif
3127 
3128 	xprt_register_transport(&xs_local_transport);
3129 	xprt_register_transport(&xs_udp_transport);
3130 	xprt_register_transport(&xs_tcp_transport);
3131 	xprt_register_transport(&xs_bc_tcp_transport);
3132 
3133 	return 0;
3134 }
3135 
3136 /**
3137  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3138  *
3139  */
3140 void cleanup_socket_xprt(void)
3141 {
3142 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3143 	if (sunrpc_table_header) {
3144 		unregister_sysctl_table(sunrpc_table_header);
3145 		sunrpc_table_header = NULL;
3146 	}
3147 #endif
3148 
3149 	xprt_unregister_transport(&xs_local_transport);
3150 	xprt_unregister_transport(&xs_udp_transport);
3151 	xprt_unregister_transport(&xs_tcp_transport);
3152 	xprt_unregister_transport(&xs_bc_tcp_transport);
3153 }
3154 
3155 static int param_set_uint_minmax(const char *val,
3156 		const struct kernel_param *kp,
3157 		unsigned int min, unsigned int max)
3158 {
3159 	unsigned int num;
3160 	int ret;
3161 
3162 	if (!val)
3163 		return -EINVAL;
3164 	ret = kstrtouint(val, 0, &num);
3165 	if (ret == -EINVAL || num < min || num > max)
3166 		return -EINVAL;
3167 	*((unsigned int *)kp->arg) = num;
3168 	return 0;
3169 }
3170 
3171 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3172 {
3173 	if (kp->arg == &xprt_min_resvport)
3174 		return param_set_uint_minmax(val, kp,
3175 			RPC_MIN_RESVPORT,
3176 			xprt_max_resvport);
3177 	return param_set_uint_minmax(val, kp,
3178 			xprt_min_resvport,
3179 			RPC_MAX_RESVPORT);
3180 }
3181 
3182 static const struct kernel_param_ops param_ops_portnr = {
3183 	.set = param_set_portnr,
3184 	.get = param_get_uint,
3185 };
3186 
3187 #define param_check_portnr(name, p) \
3188 	__param_check(name, p, unsigned int);
3189 
3190 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3191 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3192 
3193 static int param_set_slot_table_size(const char *val,
3194 				     const struct kernel_param *kp)
3195 {
3196 	return param_set_uint_minmax(val, kp,
3197 			RPC_MIN_SLOT_TABLE,
3198 			RPC_MAX_SLOT_TABLE);
3199 }
3200 
3201 static const struct kernel_param_ops param_ops_slot_table_size = {
3202 	.set = param_set_slot_table_size,
3203 	.get = param_get_uint,
3204 };
3205 
3206 #define param_check_slot_table_size(name, p) \
3207 	__param_check(name, p, unsigned int);
3208 
3209 static int param_set_max_slot_table_size(const char *val,
3210 				     const struct kernel_param *kp)
3211 {
3212 	return param_set_uint_minmax(val, kp,
3213 			RPC_MIN_SLOT_TABLE,
3214 			RPC_MAX_SLOT_TABLE_LIMIT);
3215 }
3216 
3217 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3218 	.set = param_set_max_slot_table_size,
3219 	.get = param_get_uint,
3220 };
3221 
3222 #define param_check_max_slot_table_size(name, p) \
3223 	__param_check(name, p, unsigned int);
3224 
3225 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3226 		   slot_table_size, 0644);
3227 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3228 		   max_slot_table_size, 0644);
3229 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3230 		   slot_table_size, 0644);
3231 
3232