xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision a2fb4d78)
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 #define XS_TCP_LINGER_TO	(15U * HZ)
67 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
68 
69 /*
70  * We can register our own files under /proc/sys/sunrpc by
71  * calling register_sysctl_table() again.  The files in that
72  * directory become the union of all files registered there.
73  *
74  * We simply need to make sure that we don't collide with
75  * someone else's file names!
76  */
77 
78 #ifdef RPC_DEBUG
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_limit
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_limit,
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 #ifdef RPC_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 struct sock_xprt {
220 	struct rpc_xprt		xprt;
221 
222 	/*
223 	 * Network layer
224 	 */
225 	struct socket *		sock;
226 	struct sock *		inet;
227 
228 	/*
229 	 * State of TCP reply receive
230 	 */
231 	__be32			tcp_fraghdr,
232 				tcp_xid,
233 				tcp_calldir;
234 
235 	u32			tcp_offset,
236 				tcp_reclen;
237 
238 	unsigned long		tcp_copied,
239 				tcp_flags;
240 
241 	/*
242 	 * Connection of transports
243 	 */
244 	struct delayed_work	connect_worker;
245 	struct sockaddr_storage	srcaddr;
246 	unsigned short		srcport;
247 
248 	/*
249 	 * UDP socket buffer size parameters
250 	 */
251 	size_t			rcvsize,
252 				sndsize;
253 
254 	/*
255 	 * Saved socket callback addresses
256 	 */
257 	void			(*old_data_ready)(struct sock *, int);
258 	void			(*old_state_change)(struct sock *);
259 	void			(*old_write_space)(struct sock *);
260 	void			(*old_error_report)(struct sock *);
261 };
262 
263 /*
264  * TCP receive state flags
265  */
266 #define TCP_RCV_LAST_FRAG	(1UL << 0)
267 #define TCP_RCV_COPY_FRAGHDR	(1UL << 1)
268 #define TCP_RCV_COPY_XID	(1UL << 2)
269 #define TCP_RCV_COPY_DATA	(1UL << 3)
270 #define TCP_RCV_READ_CALLDIR	(1UL << 4)
271 #define TCP_RCV_COPY_CALLDIR	(1UL << 5)
272 
273 /*
274  * TCP RPC flags
275  */
276 #define TCP_RPC_REPLY		(1UL << 6)
277 
278 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
279 {
280 	return (struct rpc_xprt *) sk->sk_user_data;
281 }
282 
283 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
284 {
285 	return (struct sockaddr *) &xprt->addr;
286 }
287 
288 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
289 {
290 	return (struct sockaddr_un *) &xprt->addr;
291 }
292 
293 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
294 {
295 	return (struct sockaddr_in *) &xprt->addr;
296 }
297 
298 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
299 {
300 	return (struct sockaddr_in6 *) &xprt->addr;
301 }
302 
303 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
304 {
305 	struct sockaddr *sap = xs_addr(xprt);
306 	struct sockaddr_in6 *sin6;
307 	struct sockaddr_in *sin;
308 	struct sockaddr_un *sun;
309 	char buf[128];
310 
311 	switch (sap->sa_family) {
312 	case AF_LOCAL:
313 		sun = xs_addr_un(xprt);
314 		strlcpy(buf, sun->sun_path, sizeof(buf));
315 		xprt->address_strings[RPC_DISPLAY_ADDR] =
316 						kstrdup(buf, GFP_KERNEL);
317 		break;
318 	case AF_INET:
319 		(void)rpc_ntop(sap, buf, sizeof(buf));
320 		xprt->address_strings[RPC_DISPLAY_ADDR] =
321 						kstrdup(buf, GFP_KERNEL);
322 		sin = xs_addr_in(xprt);
323 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
324 		break;
325 	case AF_INET6:
326 		(void)rpc_ntop(sap, buf, sizeof(buf));
327 		xprt->address_strings[RPC_DISPLAY_ADDR] =
328 						kstrdup(buf, GFP_KERNEL);
329 		sin6 = xs_addr_in6(xprt);
330 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
331 		break;
332 	default:
333 		BUG();
334 	}
335 
336 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
337 }
338 
339 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
340 {
341 	struct sockaddr *sap = xs_addr(xprt);
342 	char buf[128];
343 
344 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
345 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
346 
347 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
348 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
349 }
350 
351 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
352 				     const char *protocol,
353 				     const char *netid)
354 {
355 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
356 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
357 	xs_format_common_peer_addresses(xprt);
358 	xs_format_common_peer_ports(xprt);
359 }
360 
361 static void xs_update_peer_port(struct rpc_xprt *xprt)
362 {
363 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
364 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
365 
366 	xs_format_common_peer_ports(xprt);
367 }
368 
369 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
370 {
371 	unsigned int i;
372 
373 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
374 		switch (i) {
375 		case RPC_DISPLAY_PROTO:
376 		case RPC_DISPLAY_NETID:
377 			continue;
378 		default:
379 			kfree(xprt->address_strings[i]);
380 		}
381 }
382 
383 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
384 
385 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
386 {
387 	struct msghdr msg = {
388 		.msg_name	= addr,
389 		.msg_namelen	= addrlen,
390 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
391 	};
392 	struct kvec iov = {
393 		.iov_base	= vec->iov_base + base,
394 		.iov_len	= vec->iov_len - base,
395 	};
396 
397 	if (iov.iov_len != 0)
398 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
399 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
400 }
401 
402 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy)
403 {
404 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
405 			int offset, size_t size, int flags);
406 	struct page **ppage;
407 	unsigned int remainder;
408 	int err, sent = 0;
409 
410 	remainder = xdr->page_len - base;
411 	base += xdr->page_base;
412 	ppage = xdr->pages + (base >> PAGE_SHIFT);
413 	base &= ~PAGE_MASK;
414 	do_sendpage = sock->ops->sendpage;
415 	if (!zerocopy)
416 		do_sendpage = sock_no_sendpage;
417 	for(;;) {
418 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
419 		int flags = XS_SENDMSG_FLAGS;
420 
421 		remainder -= len;
422 		if (remainder != 0 || more)
423 			flags |= MSG_MORE;
424 		err = do_sendpage(sock, *ppage, base, len, flags);
425 		if (remainder == 0 || err != len)
426 			break;
427 		sent += err;
428 		ppage++;
429 		base = 0;
430 	}
431 	if (sent == 0)
432 		return err;
433 	if (err > 0)
434 		sent += err;
435 	return sent;
436 }
437 
438 /**
439  * xs_sendpages - write pages directly to a socket
440  * @sock: socket to send on
441  * @addr: UDP only -- address of destination
442  * @addrlen: UDP only -- length of destination address
443  * @xdr: buffer containing this request
444  * @base: starting position in the buffer
445  * @zerocopy: true if it is safe to use sendpage()
446  *
447  */
448 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy)
449 {
450 	unsigned int remainder = xdr->len - base;
451 	int err, sent = 0;
452 
453 	if (unlikely(!sock))
454 		return -ENOTSOCK;
455 
456 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
457 	if (base != 0) {
458 		addr = NULL;
459 		addrlen = 0;
460 	}
461 
462 	if (base < xdr->head[0].iov_len || addr != NULL) {
463 		unsigned int len = xdr->head[0].iov_len - base;
464 		remainder -= len;
465 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
466 		if (remainder == 0 || err != len)
467 			goto out;
468 		sent += err;
469 		base = 0;
470 	} else
471 		base -= xdr->head[0].iov_len;
472 
473 	if (base < xdr->page_len) {
474 		unsigned int len = xdr->page_len - base;
475 		remainder -= len;
476 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy);
477 		if (remainder == 0 || err != len)
478 			goto out;
479 		sent += err;
480 		base = 0;
481 	} else
482 		base -= xdr->page_len;
483 
484 	if (base >= xdr->tail[0].iov_len)
485 		return sent;
486 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
487 out:
488 	if (sent == 0)
489 		return err;
490 	if (err > 0)
491 		sent += err;
492 	return sent;
493 }
494 
495 static void xs_nospace_callback(struct rpc_task *task)
496 {
497 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
498 
499 	transport->inet->sk_write_pending--;
500 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
501 }
502 
503 /**
504  * xs_nospace - place task on wait queue if transmit was incomplete
505  * @task: task to put to sleep
506  *
507  */
508 static int xs_nospace(struct rpc_task *task)
509 {
510 	struct rpc_rqst *req = task->tk_rqstp;
511 	struct rpc_xprt *xprt = req->rq_xprt;
512 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
513 	struct sock *sk = transport->inet;
514 	int ret = -EAGAIN;
515 
516 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
517 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
518 			req->rq_slen);
519 
520 	/* Protect against races with write_space */
521 	spin_lock_bh(&xprt->transport_lock);
522 
523 	/* Don't race with disconnect */
524 	if (xprt_connected(xprt)) {
525 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
526 			/*
527 			 * Notify TCP that we're limited by the application
528 			 * window size
529 			 */
530 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
531 			sk->sk_write_pending++;
532 			/* ...and wait for more buffer space */
533 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
534 		}
535 	} else {
536 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
537 		ret = -ENOTCONN;
538 	}
539 
540 	spin_unlock_bh(&xprt->transport_lock);
541 
542 	/* Race breaker in case memory is freed before above code is called */
543 	sk->sk_write_space(sk);
544 	return ret;
545 }
546 
547 /*
548  * Construct a stream transport record marker in @buf.
549  */
550 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
551 {
552 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
553 	rpc_fraghdr *base = buf->head[0].iov_base;
554 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
555 }
556 
557 /**
558  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
559  * @task: RPC task that manages the state of an RPC request
560  *
561  * Return values:
562  *        0:	The request has been sent
563  *   EAGAIN:	The socket was blocked, please call again later to
564  *		complete the request
565  * ENOTCONN:	Caller needs to invoke connect logic then call again
566  *    other:	Some other error occured, the request was not sent
567  */
568 static int xs_local_send_request(struct rpc_task *task)
569 {
570 	struct rpc_rqst *req = task->tk_rqstp;
571 	struct rpc_xprt *xprt = req->rq_xprt;
572 	struct sock_xprt *transport =
573 				container_of(xprt, struct sock_xprt, xprt);
574 	struct xdr_buf *xdr = &req->rq_snd_buf;
575 	int status;
576 
577 	xs_encode_stream_record_marker(&req->rq_snd_buf);
578 
579 	xs_pktdump("packet data:",
580 			req->rq_svec->iov_base, req->rq_svec->iov_len);
581 
582 	status = xs_sendpages(transport->sock, NULL, 0,
583 						xdr, req->rq_bytes_sent, true);
584 	dprintk("RPC:       %s(%u) = %d\n",
585 			__func__, xdr->len - req->rq_bytes_sent, status);
586 	if (likely(status >= 0)) {
587 		req->rq_bytes_sent += status;
588 		req->rq_xmit_bytes_sent += status;
589 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
590 			req->rq_bytes_sent = 0;
591 			return 0;
592 		}
593 		status = -EAGAIN;
594 	}
595 
596 	switch (status) {
597 	case -EAGAIN:
598 		status = xs_nospace(task);
599 		break;
600 	default:
601 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
602 			-status);
603 	case -EPIPE:
604 		xs_close(xprt);
605 		status = -ENOTCONN;
606 	}
607 
608 	return status;
609 }
610 
611 /**
612  * xs_udp_send_request - write an RPC request to a UDP socket
613  * @task: address of RPC task that manages the state of an RPC request
614  *
615  * Return values:
616  *        0:	The request has been sent
617  *   EAGAIN:	The socket was blocked, please call again later to
618  *		complete the request
619  * ENOTCONN:	Caller needs to invoke connect logic then call again
620  *    other:	Some other error occurred, the request was not sent
621  */
622 static int xs_udp_send_request(struct rpc_task *task)
623 {
624 	struct rpc_rqst *req = task->tk_rqstp;
625 	struct rpc_xprt *xprt = req->rq_xprt;
626 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
627 	struct xdr_buf *xdr = &req->rq_snd_buf;
628 	int status;
629 
630 	xs_pktdump("packet data:",
631 				req->rq_svec->iov_base,
632 				req->rq_svec->iov_len);
633 
634 	if (!xprt_bound(xprt))
635 		return -ENOTCONN;
636 	status = xs_sendpages(transport->sock,
637 			      xs_addr(xprt),
638 			      xprt->addrlen, xdr,
639 			      req->rq_bytes_sent, true);
640 
641 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
642 			xdr->len - req->rq_bytes_sent, status);
643 
644 	if (status >= 0) {
645 		req->rq_xmit_bytes_sent += status;
646 		if (status >= req->rq_slen)
647 			return 0;
648 		/* Still some bytes left; set up for a retry later. */
649 		status = -EAGAIN;
650 	}
651 
652 	switch (status) {
653 	case -ENOTSOCK:
654 		status = -ENOTCONN;
655 		/* Should we call xs_close() here? */
656 		break;
657 	case -EAGAIN:
658 		status = xs_nospace(task);
659 		break;
660 	default:
661 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
662 			-status);
663 	case -ENETUNREACH:
664 	case -EPIPE:
665 	case -ECONNREFUSED:
666 		/* When the server has died, an ICMP port unreachable message
667 		 * prompts ECONNREFUSED. */
668 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
669 	}
670 
671 	return status;
672 }
673 
674 /**
675  * xs_tcp_shutdown - gracefully shut down a TCP socket
676  * @xprt: transport
677  *
678  * Initiates a graceful shutdown of the TCP socket by calling the
679  * equivalent of shutdown(SHUT_WR);
680  */
681 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
682 {
683 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
684 	struct socket *sock = transport->sock;
685 
686 	if (sock != NULL) {
687 		kernel_sock_shutdown(sock, SHUT_WR);
688 		trace_rpc_socket_shutdown(xprt, sock);
689 	}
690 }
691 
692 /**
693  * xs_tcp_send_request - write an RPC request to a TCP socket
694  * @task: address of RPC task that manages the state of an RPC request
695  *
696  * Return values:
697  *        0:	The request has been sent
698  *   EAGAIN:	The socket was blocked, please call again later to
699  *		complete the request
700  * ENOTCONN:	Caller needs to invoke connect logic then call again
701  *    other:	Some other error occurred, the request was not sent
702  *
703  * XXX: In the case of soft timeouts, should we eventually give up
704  *	if sendmsg is not able to make progress?
705  */
706 static int xs_tcp_send_request(struct rpc_task *task)
707 {
708 	struct rpc_rqst *req = task->tk_rqstp;
709 	struct rpc_xprt *xprt = req->rq_xprt;
710 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
711 	struct xdr_buf *xdr = &req->rq_snd_buf;
712 	bool zerocopy = true;
713 	int status;
714 
715 	xs_encode_stream_record_marker(&req->rq_snd_buf);
716 
717 	xs_pktdump("packet data:",
718 				req->rq_svec->iov_base,
719 				req->rq_svec->iov_len);
720 	/* Don't use zero copy if this is a resend. If the RPC call
721 	 * completes while the socket holds a reference to the pages,
722 	 * then we may end up resending corrupted data.
723 	 */
724 	if (task->tk_flags & RPC_TASK_SENT)
725 		zerocopy = false;
726 
727 	/* Continue transmitting the packet/record. We must be careful
728 	 * to cope with writespace callbacks arriving _after_ we have
729 	 * called sendmsg(). */
730 	while (1) {
731 		status = xs_sendpages(transport->sock,
732 					NULL, 0, xdr, req->rq_bytes_sent,
733 					zerocopy);
734 
735 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
736 				xdr->len - req->rq_bytes_sent, status);
737 
738 		if (unlikely(status < 0))
739 			break;
740 
741 		/* If we've sent the entire packet, immediately
742 		 * reset the count of bytes sent. */
743 		req->rq_bytes_sent += status;
744 		req->rq_xmit_bytes_sent += status;
745 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
746 			req->rq_bytes_sent = 0;
747 			return 0;
748 		}
749 
750 		if (status != 0)
751 			continue;
752 		status = -EAGAIN;
753 		break;
754 	}
755 
756 	switch (status) {
757 	case -ENOTSOCK:
758 		status = -ENOTCONN;
759 		/* Should we call xs_close() here? */
760 		break;
761 	case -EAGAIN:
762 		status = xs_nospace(task);
763 		break;
764 	default:
765 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
766 			-status);
767 	case -ECONNRESET:
768 		xs_tcp_shutdown(xprt);
769 	case -ECONNREFUSED:
770 	case -ENOTCONN:
771 	case -EPIPE:
772 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
773 	}
774 
775 	return status;
776 }
777 
778 /**
779  * xs_tcp_release_xprt - clean up after a tcp transmission
780  * @xprt: transport
781  * @task: rpc task
782  *
783  * This cleans up if an error causes us to abort the transmission of a request.
784  * In this case, the socket may need to be reset in order to avoid confusing
785  * the server.
786  */
787 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
788 {
789 	struct rpc_rqst *req;
790 
791 	if (task != xprt->snd_task)
792 		return;
793 	if (task == NULL)
794 		goto out_release;
795 	req = task->tk_rqstp;
796 	if (req == NULL)
797 		goto out_release;
798 	if (req->rq_bytes_sent == 0)
799 		goto out_release;
800 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
801 		goto out_release;
802 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
803 out_release:
804 	xprt_release_xprt(xprt, task);
805 }
806 
807 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
808 {
809 	transport->old_data_ready = sk->sk_data_ready;
810 	transport->old_state_change = sk->sk_state_change;
811 	transport->old_write_space = sk->sk_write_space;
812 	transport->old_error_report = sk->sk_error_report;
813 }
814 
815 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
816 {
817 	sk->sk_data_ready = transport->old_data_ready;
818 	sk->sk_state_change = transport->old_state_change;
819 	sk->sk_write_space = transport->old_write_space;
820 	sk->sk_error_report = transport->old_error_report;
821 }
822 
823 /**
824  * xs_error_report - callback to handle TCP socket state errors
825  * @sk: socket
826  *
827  * Note: we don't call sock_error() since there may be a rpc_task
828  * using the socket, and so we don't want to clear sk->sk_err.
829  */
830 static void xs_error_report(struct sock *sk)
831 {
832 	struct rpc_xprt *xprt;
833 	int err;
834 
835 	read_lock_bh(&sk->sk_callback_lock);
836 	if (!(xprt = xprt_from_sock(sk)))
837 		goto out;
838 
839 	err = -sk->sk_err;
840 	if (err == 0)
841 		goto out;
842 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
843 			xprt, -err);
844 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
845 	xprt_wake_pending_tasks(xprt, err);
846  out:
847 	read_unlock_bh(&sk->sk_callback_lock);
848 }
849 
850 static void xs_reset_transport(struct sock_xprt *transport)
851 {
852 	struct socket *sock = transport->sock;
853 	struct sock *sk = transport->inet;
854 
855 	if (sk == NULL)
856 		return;
857 
858 	transport->srcport = 0;
859 
860 	write_lock_bh(&sk->sk_callback_lock);
861 	transport->inet = NULL;
862 	transport->sock = NULL;
863 
864 	sk->sk_user_data = NULL;
865 
866 	xs_restore_old_callbacks(transport, sk);
867 	write_unlock_bh(&sk->sk_callback_lock);
868 
869 	sk->sk_no_check = 0;
870 
871 	trace_rpc_socket_close(&transport->xprt, sock);
872 	sock_release(sock);
873 }
874 
875 /**
876  * xs_close - close a socket
877  * @xprt: transport
878  *
879  * This is used when all requests are complete; ie, no DRC state remains
880  * on the server we want to save.
881  *
882  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
883  * xs_reset_transport() zeroing the socket from underneath a writer.
884  */
885 static void xs_close(struct rpc_xprt *xprt)
886 {
887 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
888 
889 	dprintk("RPC:       xs_close xprt %p\n", xprt);
890 
891 	cancel_delayed_work_sync(&transport->connect_worker);
892 
893 	xs_reset_transport(transport);
894 	xprt->reestablish_timeout = 0;
895 
896 	smp_mb__before_clear_bit();
897 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
898 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
899 	clear_bit(XPRT_CLOSING, &xprt->state);
900 	smp_mb__after_clear_bit();
901 	xprt_disconnect_done(xprt);
902 }
903 
904 static void xs_tcp_close(struct rpc_xprt *xprt)
905 {
906 	if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
907 		xs_close(xprt);
908 	else
909 		xs_tcp_shutdown(xprt);
910 }
911 
912 /**
913  * xs_destroy - prepare to shutdown a transport
914  * @xprt: doomed transport
915  *
916  */
917 static void xs_destroy(struct rpc_xprt *xprt)
918 {
919 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
920 
921 	xs_close(xprt);
922 	xs_free_peer_addresses(xprt);
923 	xprt_free(xprt);
924 	module_put(THIS_MODULE);
925 }
926 
927 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
928 {
929 	struct xdr_skb_reader desc = {
930 		.skb		= skb,
931 		.offset		= sizeof(rpc_fraghdr),
932 		.count		= skb->len - sizeof(rpc_fraghdr),
933 	};
934 
935 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
936 		return -1;
937 	if (desc.count)
938 		return -1;
939 	return 0;
940 }
941 
942 /**
943  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
944  * @sk: socket with data to read
945  * @len: how much data to read
946  *
947  * Currently this assumes we can read the whole reply in a single gulp.
948  */
949 static void xs_local_data_ready(struct sock *sk, int len)
950 {
951 	struct rpc_task *task;
952 	struct rpc_xprt *xprt;
953 	struct rpc_rqst *rovr;
954 	struct sk_buff *skb;
955 	int err, repsize, copied;
956 	u32 _xid;
957 	__be32 *xp;
958 
959 	read_lock_bh(&sk->sk_callback_lock);
960 	dprintk("RPC:       %s...\n", __func__);
961 	xprt = xprt_from_sock(sk);
962 	if (xprt == NULL)
963 		goto out;
964 
965 	skb = skb_recv_datagram(sk, 0, 1, &err);
966 	if (skb == NULL)
967 		goto out;
968 
969 	repsize = skb->len - sizeof(rpc_fraghdr);
970 	if (repsize < 4) {
971 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
972 		goto dropit;
973 	}
974 
975 	/* Copy the XID from the skb... */
976 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
977 	if (xp == NULL)
978 		goto dropit;
979 
980 	/* Look up and lock the request corresponding to the given XID */
981 	spin_lock(&xprt->transport_lock);
982 	rovr = xprt_lookup_rqst(xprt, *xp);
983 	if (!rovr)
984 		goto out_unlock;
985 	task = rovr->rq_task;
986 
987 	copied = rovr->rq_private_buf.buflen;
988 	if (copied > repsize)
989 		copied = repsize;
990 
991 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
992 		dprintk("RPC:       sk_buff copy failed\n");
993 		goto out_unlock;
994 	}
995 
996 	xprt_complete_rqst(task, copied);
997 
998  out_unlock:
999 	spin_unlock(&xprt->transport_lock);
1000  dropit:
1001 	skb_free_datagram(sk, skb);
1002  out:
1003 	read_unlock_bh(&sk->sk_callback_lock);
1004 }
1005 
1006 /**
1007  * xs_udp_data_ready - "data ready" callback for UDP sockets
1008  * @sk: socket with data to read
1009  * @len: how much data to read
1010  *
1011  */
1012 static void xs_udp_data_ready(struct sock *sk, int len)
1013 {
1014 	struct rpc_task *task;
1015 	struct rpc_xprt *xprt;
1016 	struct rpc_rqst *rovr;
1017 	struct sk_buff *skb;
1018 	int err, repsize, copied;
1019 	u32 _xid;
1020 	__be32 *xp;
1021 
1022 	read_lock_bh(&sk->sk_callback_lock);
1023 	dprintk("RPC:       xs_udp_data_ready...\n");
1024 	if (!(xprt = xprt_from_sock(sk)))
1025 		goto out;
1026 
1027 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
1028 		goto out;
1029 
1030 	repsize = skb->len - sizeof(struct udphdr);
1031 	if (repsize < 4) {
1032 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1033 		goto dropit;
1034 	}
1035 
1036 	/* Copy the XID from the skb... */
1037 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
1038 				sizeof(_xid), &_xid);
1039 	if (xp == NULL)
1040 		goto dropit;
1041 
1042 	/* Look up and lock the request corresponding to the given XID */
1043 	spin_lock(&xprt->transport_lock);
1044 	rovr = xprt_lookup_rqst(xprt, *xp);
1045 	if (!rovr)
1046 		goto out_unlock;
1047 	task = rovr->rq_task;
1048 
1049 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1050 		copied = repsize;
1051 
1052 	/* Suck it into the iovec, verify checksum if not done by hw. */
1053 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1054 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1055 		goto out_unlock;
1056 	}
1057 
1058 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1059 
1060 	xprt_adjust_cwnd(xprt, task, copied);
1061 	xprt_complete_rqst(task, copied);
1062 
1063  out_unlock:
1064 	spin_unlock(&xprt->transport_lock);
1065  dropit:
1066 	skb_free_datagram(sk, skb);
1067  out:
1068 	read_unlock_bh(&sk->sk_callback_lock);
1069 }
1070 
1071 /*
1072  * Helper function to force a TCP close if the server is sending
1073  * junk and/or it has put us in CLOSE_WAIT
1074  */
1075 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1076 {
1077 	set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1078 	xprt_force_disconnect(xprt);
1079 }
1080 
1081 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1082 {
1083 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1084 	size_t len, used;
1085 	char *p;
1086 
1087 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1088 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1089 	used = xdr_skb_read_bits(desc, p, len);
1090 	transport->tcp_offset += used;
1091 	if (used != len)
1092 		return;
1093 
1094 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1095 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1096 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1097 	else
1098 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1099 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1100 
1101 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1102 	transport->tcp_offset = 0;
1103 
1104 	/* Sanity check of the record length */
1105 	if (unlikely(transport->tcp_reclen < 8)) {
1106 		dprintk("RPC:       invalid TCP record fragment length\n");
1107 		xs_tcp_force_close(xprt);
1108 		return;
1109 	}
1110 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1111 			transport->tcp_reclen);
1112 }
1113 
1114 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1115 {
1116 	if (transport->tcp_offset == transport->tcp_reclen) {
1117 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1118 		transport->tcp_offset = 0;
1119 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1120 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1121 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1122 			transport->tcp_copied = 0;
1123 		}
1124 	}
1125 }
1126 
1127 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1128 {
1129 	size_t len, used;
1130 	char *p;
1131 
1132 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1133 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1134 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1135 	used = xdr_skb_read_bits(desc, p, len);
1136 	transport->tcp_offset += used;
1137 	if (used != len)
1138 		return;
1139 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1140 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1141 	transport->tcp_copied = 4;
1142 	dprintk("RPC:       reading %s XID %08x\n",
1143 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1144 							      : "request with",
1145 			ntohl(transport->tcp_xid));
1146 	xs_tcp_check_fraghdr(transport);
1147 }
1148 
1149 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1150 				       struct xdr_skb_reader *desc)
1151 {
1152 	size_t len, used;
1153 	u32 offset;
1154 	char *p;
1155 
1156 	/*
1157 	 * We want transport->tcp_offset to be 8 at the end of this routine
1158 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1159 	 * When this function is called for the first time,
1160 	 * transport->tcp_offset is 4 (after having already read the xid).
1161 	 */
1162 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1163 	len = sizeof(transport->tcp_calldir) - offset;
1164 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1165 	p = ((char *) &transport->tcp_calldir) + offset;
1166 	used = xdr_skb_read_bits(desc, p, len);
1167 	transport->tcp_offset += used;
1168 	if (used != len)
1169 		return;
1170 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1171 	/*
1172 	 * We don't yet have the XDR buffer, so we will write the calldir
1173 	 * out after we get the buffer from the 'struct rpc_rqst'
1174 	 */
1175 	switch (ntohl(transport->tcp_calldir)) {
1176 	case RPC_REPLY:
1177 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1178 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1179 		transport->tcp_flags |= TCP_RPC_REPLY;
1180 		break;
1181 	case RPC_CALL:
1182 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1183 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1184 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1185 		break;
1186 	default:
1187 		dprintk("RPC:       invalid request message type\n");
1188 		xs_tcp_force_close(&transport->xprt);
1189 	}
1190 	xs_tcp_check_fraghdr(transport);
1191 }
1192 
1193 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1194 				     struct xdr_skb_reader *desc,
1195 				     struct rpc_rqst *req)
1196 {
1197 	struct sock_xprt *transport =
1198 				container_of(xprt, struct sock_xprt, xprt);
1199 	struct xdr_buf *rcvbuf;
1200 	size_t len;
1201 	ssize_t r;
1202 
1203 	rcvbuf = &req->rq_private_buf;
1204 
1205 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1206 		/*
1207 		 * Save the RPC direction in the XDR buffer
1208 		 */
1209 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1210 			&transport->tcp_calldir,
1211 			sizeof(transport->tcp_calldir));
1212 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1213 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1214 	}
1215 
1216 	len = desc->count;
1217 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1218 		struct xdr_skb_reader my_desc;
1219 
1220 		len = transport->tcp_reclen - transport->tcp_offset;
1221 		memcpy(&my_desc, desc, sizeof(my_desc));
1222 		my_desc.count = len;
1223 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1224 					  &my_desc, xdr_skb_read_bits);
1225 		desc->count -= r;
1226 		desc->offset += r;
1227 	} else
1228 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1229 					  desc, xdr_skb_read_bits);
1230 
1231 	if (r > 0) {
1232 		transport->tcp_copied += r;
1233 		transport->tcp_offset += r;
1234 	}
1235 	if (r != len) {
1236 		/* Error when copying to the receive buffer,
1237 		 * usually because we weren't able to allocate
1238 		 * additional buffer pages. All we can do now
1239 		 * is turn off TCP_RCV_COPY_DATA, so the request
1240 		 * will not receive any additional updates,
1241 		 * and time out.
1242 		 * Any remaining data from this record will
1243 		 * be discarded.
1244 		 */
1245 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1246 		dprintk("RPC:       XID %08x truncated request\n",
1247 				ntohl(transport->tcp_xid));
1248 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1249 				"tcp_offset = %u, tcp_reclen = %u\n",
1250 				xprt, transport->tcp_copied,
1251 				transport->tcp_offset, transport->tcp_reclen);
1252 		return;
1253 	}
1254 
1255 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1256 			ntohl(transport->tcp_xid), r);
1257 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1258 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1259 			transport->tcp_offset, transport->tcp_reclen);
1260 
1261 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1262 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1263 	else if (transport->tcp_offset == transport->tcp_reclen) {
1264 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1265 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1266 	}
1267 }
1268 
1269 /*
1270  * Finds the request corresponding to the RPC xid and invokes the common
1271  * tcp read code to read the data.
1272  */
1273 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1274 				    struct xdr_skb_reader *desc)
1275 {
1276 	struct sock_xprt *transport =
1277 				container_of(xprt, struct sock_xprt, xprt);
1278 	struct rpc_rqst *req;
1279 
1280 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1281 
1282 	/* Find and lock the request corresponding to this xid */
1283 	spin_lock(&xprt->transport_lock);
1284 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1285 	if (!req) {
1286 		dprintk("RPC:       XID %08x request not found!\n",
1287 				ntohl(transport->tcp_xid));
1288 		spin_unlock(&xprt->transport_lock);
1289 		return -1;
1290 	}
1291 
1292 	xs_tcp_read_common(xprt, desc, req);
1293 
1294 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1295 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1296 
1297 	spin_unlock(&xprt->transport_lock);
1298 	return 0;
1299 }
1300 
1301 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1302 /*
1303  * Obtains an rpc_rqst previously allocated and invokes the common
1304  * tcp read code to read the data.  The result is placed in the callback
1305  * queue.
1306  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1307  * connection and return -1.
1308  */
1309 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1310 				       struct xdr_skb_reader *desc)
1311 {
1312 	struct sock_xprt *transport =
1313 				container_of(xprt, struct sock_xprt, xprt);
1314 	struct rpc_rqst *req;
1315 
1316 	req = xprt_alloc_bc_request(xprt);
1317 	if (req == NULL) {
1318 		printk(KERN_WARNING "Callback slot table overflowed\n");
1319 		xprt_force_disconnect(xprt);
1320 		return -1;
1321 	}
1322 
1323 	req->rq_xid = transport->tcp_xid;
1324 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1325 	xs_tcp_read_common(xprt, desc, req);
1326 
1327 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1328 		struct svc_serv *bc_serv = xprt->bc_serv;
1329 
1330 		/*
1331 		 * Add callback request to callback list.  The callback
1332 		 * service sleeps on the sv_cb_waitq waiting for new
1333 		 * requests.  Wake it up after adding enqueing the
1334 		 * request.
1335 		 */
1336 		dprintk("RPC:       add callback request to list\n");
1337 		spin_lock(&bc_serv->sv_cb_lock);
1338 		list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1339 		spin_unlock(&bc_serv->sv_cb_lock);
1340 		wake_up(&bc_serv->sv_cb_waitq);
1341 	}
1342 
1343 	req->rq_private_buf.len = transport->tcp_copied;
1344 
1345 	return 0;
1346 }
1347 
1348 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1349 					struct xdr_skb_reader *desc)
1350 {
1351 	struct sock_xprt *transport =
1352 				container_of(xprt, struct sock_xprt, xprt);
1353 
1354 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1355 		xs_tcp_read_reply(xprt, desc) :
1356 		xs_tcp_read_callback(xprt, desc);
1357 }
1358 #else
1359 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1360 					struct xdr_skb_reader *desc)
1361 {
1362 	return xs_tcp_read_reply(xprt, desc);
1363 }
1364 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1365 
1366 /*
1367  * Read data off the transport.  This can be either an RPC_CALL or an
1368  * RPC_REPLY.  Relay the processing to helper functions.
1369  */
1370 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1371 				    struct xdr_skb_reader *desc)
1372 {
1373 	struct sock_xprt *transport =
1374 				container_of(xprt, struct sock_xprt, xprt);
1375 
1376 	if (_xs_tcp_read_data(xprt, desc) == 0)
1377 		xs_tcp_check_fraghdr(transport);
1378 	else {
1379 		/*
1380 		 * The transport_lock protects the request handling.
1381 		 * There's no need to hold it to update the tcp_flags.
1382 		 */
1383 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1384 	}
1385 }
1386 
1387 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1388 {
1389 	size_t len;
1390 
1391 	len = transport->tcp_reclen - transport->tcp_offset;
1392 	if (len > desc->count)
1393 		len = desc->count;
1394 	desc->count -= len;
1395 	desc->offset += len;
1396 	transport->tcp_offset += len;
1397 	dprintk("RPC:       discarded %Zu bytes\n", len);
1398 	xs_tcp_check_fraghdr(transport);
1399 }
1400 
1401 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1402 {
1403 	struct rpc_xprt *xprt = rd_desc->arg.data;
1404 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1405 	struct xdr_skb_reader desc = {
1406 		.skb	= skb,
1407 		.offset	= offset,
1408 		.count	= len,
1409 	};
1410 
1411 	dprintk("RPC:       xs_tcp_data_recv started\n");
1412 	do {
1413 		/* Read in a new fragment marker if necessary */
1414 		/* Can we ever really expect to get completely empty fragments? */
1415 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1416 			xs_tcp_read_fraghdr(xprt, &desc);
1417 			continue;
1418 		}
1419 		/* Read in the xid if necessary */
1420 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1421 			xs_tcp_read_xid(transport, &desc);
1422 			continue;
1423 		}
1424 		/* Read in the call/reply flag */
1425 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1426 			xs_tcp_read_calldir(transport, &desc);
1427 			continue;
1428 		}
1429 		/* Read in the request data */
1430 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1431 			xs_tcp_read_data(xprt, &desc);
1432 			continue;
1433 		}
1434 		/* Skip over any trailing bytes on short reads */
1435 		xs_tcp_read_discard(transport, &desc);
1436 	} while (desc.count);
1437 	dprintk("RPC:       xs_tcp_data_recv done\n");
1438 	return len - desc.count;
1439 }
1440 
1441 /**
1442  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1443  * @sk: socket with data to read
1444  * @bytes: how much data to read
1445  *
1446  */
1447 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1448 {
1449 	struct rpc_xprt *xprt;
1450 	read_descriptor_t rd_desc;
1451 	int read;
1452 
1453 	dprintk("RPC:       xs_tcp_data_ready...\n");
1454 
1455 	read_lock_bh(&sk->sk_callback_lock);
1456 	if (!(xprt = xprt_from_sock(sk)))
1457 		goto out;
1458 	/* Any data means we had a useful conversation, so
1459 	 * the we don't need to delay the next reconnect
1460 	 */
1461 	if (xprt->reestablish_timeout)
1462 		xprt->reestablish_timeout = 0;
1463 
1464 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1465 	rd_desc.arg.data = xprt;
1466 	do {
1467 		rd_desc.count = 65536;
1468 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1469 	} while (read > 0);
1470 out:
1471 	read_unlock_bh(&sk->sk_callback_lock);
1472 }
1473 
1474 /*
1475  * Do the equivalent of linger/linger2 handling for dealing with
1476  * broken servers that don't close the socket in a timely
1477  * fashion
1478  */
1479 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1480 		unsigned long timeout)
1481 {
1482 	struct sock_xprt *transport;
1483 
1484 	if (xprt_test_and_set_connecting(xprt))
1485 		return;
1486 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1487 	transport = container_of(xprt, struct sock_xprt, xprt);
1488 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1489 			   timeout);
1490 }
1491 
1492 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1493 {
1494 	struct sock_xprt *transport;
1495 
1496 	transport = container_of(xprt, struct sock_xprt, xprt);
1497 
1498 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1499 	    !cancel_delayed_work(&transport->connect_worker))
1500 		return;
1501 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1502 	xprt_clear_connecting(xprt);
1503 }
1504 
1505 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1506 {
1507 	smp_mb__before_clear_bit();
1508 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1509 	clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1510 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1511 	clear_bit(XPRT_CLOSING, &xprt->state);
1512 	smp_mb__after_clear_bit();
1513 }
1514 
1515 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1516 {
1517 	xs_sock_reset_connection_flags(xprt);
1518 	/* Mark transport as closed and wake up all pending tasks */
1519 	xprt_disconnect_done(xprt);
1520 }
1521 
1522 /**
1523  * xs_tcp_state_change - callback to handle TCP socket state changes
1524  * @sk: socket whose state has changed
1525  *
1526  */
1527 static void xs_tcp_state_change(struct sock *sk)
1528 {
1529 	struct rpc_xprt *xprt;
1530 
1531 	read_lock_bh(&sk->sk_callback_lock);
1532 	if (!(xprt = xprt_from_sock(sk)))
1533 		goto out;
1534 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1535 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1536 			sk->sk_state, xprt_connected(xprt),
1537 			sock_flag(sk, SOCK_DEAD),
1538 			sock_flag(sk, SOCK_ZAPPED),
1539 			sk->sk_shutdown);
1540 
1541 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1542 	switch (sk->sk_state) {
1543 	case TCP_ESTABLISHED:
1544 		spin_lock(&xprt->transport_lock);
1545 		if (!xprt_test_and_set_connected(xprt)) {
1546 			struct sock_xprt *transport = container_of(xprt,
1547 					struct sock_xprt, xprt);
1548 
1549 			/* Reset TCP record info */
1550 			transport->tcp_offset = 0;
1551 			transport->tcp_reclen = 0;
1552 			transport->tcp_copied = 0;
1553 			transport->tcp_flags =
1554 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1555 			xprt->connect_cookie++;
1556 
1557 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1558 		}
1559 		spin_unlock(&xprt->transport_lock);
1560 		break;
1561 	case TCP_FIN_WAIT1:
1562 		/* The client initiated a shutdown of the socket */
1563 		xprt->connect_cookie++;
1564 		xprt->reestablish_timeout = 0;
1565 		set_bit(XPRT_CLOSING, &xprt->state);
1566 		smp_mb__before_clear_bit();
1567 		clear_bit(XPRT_CONNECTED, &xprt->state);
1568 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1569 		smp_mb__after_clear_bit();
1570 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1571 		break;
1572 	case TCP_CLOSE_WAIT:
1573 		/* The server initiated a shutdown of the socket */
1574 		xprt->connect_cookie++;
1575 		clear_bit(XPRT_CONNECTED, &xprt->state);
1576 		xs_tcp_force_close(xprt);
1577 	case TCP_CLOSING:
1578 		/*
1579 		 * If the server closed down the connection, make sure that
1580 		 * we back off before reconnecting
1581 		 */
1582 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1583 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1584 		break;
1585 	case TCP_LAST_ACK:
1586 		set_bit(XPRT_CLOSING, &xprt->state);
1587 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1588 		smp_mb__before_clear_bit();
1589 		clear_bit(XPRT_CONNECTED, &xprt->state);
1590 		smp_mb__after_clear_bit();
1591 		break;
1592 	case TCP_CLOSE:
1593 		xs_tcp_cancel_linger_timeout(xprt);
1594 		xs_sock_mark_closed(xprt);
1595 	}
1596  out:
1597 	read_unlock_bh(&sk->sk_callback_lock);
1598 }
1599 
1600 static void xs_write_space(struct sock *sk)
1601 {
1602 	struct socket *sock;
1603 	struct rpc_xprt *xprt;
1604 
1605 	if (unlikely(!(sock = sk->sk_socket)))
1606 		return;
1607 	clear_bit(SOCK_NOSPACE, &sock->flags);
1608 
1609 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1610 		return;
1611 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1612 		return;
1613 
1614 	xprt_write_space(xprt);
1615 }
1616 
1617 /**
1618  * xs_udp_write_space - callback invoked when socket buffer space
1619  *                             becomes available
1620  * @sk: socket whose state has changed
1621  *
1622  * Called when more output buffer space is available for this socket.
1623  * We try not to wake our writers until they can make "significant"
1624  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1625  * with a bunch of small requests.
1626  */
1627 static void xs_udp_write_space(struct sock *sk)
1628 {
1629 	read_lock_bh(&sk->sk_callback_lock);
1630 
1631 	/* from net/core/sock.c:sock_def_write_space */
1632 	if (sock_writeable(sk))
1633 		xs_write_space(sk);
1634 
1635 	read_unlock_bh(&sk->sk_callback_lock);
1636 }
1637 
1638 /**
1639  * xs_tcp_write_space - callback invoked when socket buffer space
1640  *                             becomes available
1641  * @sk: socket whose state has changed
1642  *
1643  * Called when more output buffer space is available for this socket.
1644  * We try not to wake our writers until they can make "significant"
1645  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1646  * with a bunch of small requests.
1647  */
1648 static void xs_tcp_write_space(struct sock *sk)
1649 {
1650 	read_lock_bh(&sk->sk_callback_lock);
1651 
1652 	/* from net/core/stream.c:sk_stream_write_space */
1653 	if (sk_stream_is_writeable(sk))
1654 		xs_write_space(sk);
1655 
1656 	read_unlock_bh(&sk->sk_callback_lock);
1657 }
1658 
1659 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1660 {
1661 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1662 	struct sock *sk = transport->inet;
1663 
1664 	if (transport->rcvsize) {
1665 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1666 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1667 	}
1668 	if (transport->sndsize) {
1669 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1670 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1671 		sk->sk_write_space(sk);
1672 	}
1673 }
1674 
1675 /**
1676  * xs_udp_set_buffer_size - set send and receive limits
1677  * @xprt: generic transport
1678  * @sndsize: requested size of send buffer, in bytes
1679  * @rcvsize: requested size of receive buffer, in bytes
1680  *
1681  * Set socket send and receive buffer size limits.
1682  */
1683 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1684 {
1685 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1686 
1687 	transport->sndsize = 0;
1688 	if (sndsize)
1689 		transport->sndsize = sndsize + 1024;
1690 	transport->rcvsize = 0;
1691 	if (rcvsize)
1692 		transport->rcvsize = rcvsize + 1024;
1693 
1694 	xs_udp_do_set_buffer_size(xprt);
1695 }
1696 
1697 /**
1698  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1699  * @task: task that timed out
1700  *
1701  * Adjust the congestion window after a retransmit timeout has occurred.
1702  */
1703 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1704 {
1705 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1706 }
1707 
1708 static unsigned short xs_get_random_port(void)
1709 {
1710 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1711 	unsigned short rand = (unsigned short) prandom_u32() % range;
1712 	return rand + xprt_min_resvport;
1713 }
1714 
1715 /**
1716  * xs_set_port - reset the port number in the remote endpoint address
1717  * @xprt: generic transport
1718  * @port: new port number
1719  *
1720  */
1721 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1722 {
1723 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1724 
1725 	rpc_set_port(xs_addr(xprt), port);
1726 	xs_update_peer_port(xprt);
1727 }
1728 
1729 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1730 {
1731 	unsigned short port = transport->srcport;
1732 
1733 	if (port == 0 && transport->xprt.resvport)
1734 		port = xs_get_random_port();
1735 	return port;
1736 }
1737 
1738 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1739 {
1740 	if (transport->srcport != 0)
1741 		transport->srcport = 0;
1742 	if (!transport->xprt.resvport)
1743 		return 0;
1744 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1745 		return xprt_max_resvport;
1746 	return --port;
1747 }
1748 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1749 {
1750 	struct sockaddr_storage myaddr;
1751 	int err, nloop = 0;
1752 	unsigned short port = xs_get_srcport(transport);
1753 	unsigned short last;
1754 
1755 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1756 	do {
1757 		rpc_set_port((struct sockaddr *)&myaddr, port);
1758 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1759 				transport->xprt.addrlen);
1760 		if (port == 0)
1761 			break;
1762 		if (err == 0) {
1763 			transport->srcport = port;
1764 			break;
1765 		}
1766 		last = port;
1767 		port = xs_next_srcport(transport, port);
1768 		if (port > last)
1769 			nloop++;
1770 	} while (err == -EADDRINUSE && nloop != 2);
1771 
1772 	if (myaddr.ss_family == AF_INET)
1773 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1774 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1775 				port, err ? "failed" : "ok", err);
1776 	else
1777 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1778 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1779 				port, err ? "failed" : "ok", err);
1780 	return err;
1781 }
1782 
1783 /*
1784  * We don't support autobind on AF_LOCAL sockets
1785  */
1786 static void xs_local_rpcbind(struct rpc_task *task)
1787 {
1788 	rcu_read_lock();
1789 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1790 	rcu_read_unlock();
1791 }
1792 
1793 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1794 {
1795 }
1796 
1797 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1798 static struct lock_class_key xs_key[2];
1799 static struct lock_class_key xs_slock_key[2];
1800 
1801 static inline void xs_reclassify_socketu(struct socket *sock)
1802 {
1803 	struct sock *sk = sock->sk;
1804 
1805 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1806 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1807 }
1808 
1809 static inline void xs_reclassify_socket4(struct socket *sock)
1810 {
1811 	struct sock *sk = sock->sk;
1812 
1813 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1814 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1815 }
1816 
1817 static inline void xs_reclassify_socket6(struct socket *sock)
1818 {
1819 	struct sock *sk = sock->sk;
1820 
1821 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1822 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1823 }
1824 
1825 static inline void xs_reclassify_socket(int family, struct socket *sock)
1826 {
1827 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1828 	if (sock_owned_by_user(sock->sk))
1829 		return;
1830 
1831 	switch (family) {
1832 	case AF_LOCAL:
1833 		xs_reclassify_socketu(sock);
1834 		break;
1835 	case AF_INET:
1836 		xs_reclassify_socket4(sock);
1837 		break;
1838 	case AF_INET6:
1839 		xs_reclassify_socket6(sock);
1840 		break;
1841 	}
1842 }
1843 #else
1844 static inline void xs_reclassify_socketu(struct socket *sock)
1845 {
1846 }
1847 
1848 static inline void xs_reclassify_socket4(struct socket *sock)
1849 {
1850 }
1851 
1852 static inline void xs_reclassify_socket6(struct socket *sock)
1853 {
1854 }
1855 
1856 static inline void xs_reclassify_socket(int family, struct socket *sock)
1857 {
1858 }
1859 #endif
1860 
1861 static void xs_dummy_setup_socket(struct work_struct *work)
1862 {
1863 }
1864 
1865 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1866 		struct sock_xprt *transport, int family, int type, int protocol)
1867 {
1868 	struct socket *sock;
1869 	int err;
1870 
1871 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1872 	if (err < 0) {
1873 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1874 				protocol, -err);
1875 		goto out;
1876 	}
1877 	xs_reclassify_socket(family, sock);
1878 
1879 	err = xs_bind(transport, sock);
1880 	if (err) {
1881 		sock_release(sock);
1882 		goto out;
1883 	}
1884 
1885 	return sock;
1886 out:
1887 	return ERR_PTR(err);
1888 }
1889 
1890 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1891 				      struct socket *sock)
1892 {
1893 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1894 									xprt);
1895 
1896 	if (!transport->inet) {
1897 		struct sock *sk = sock->sk;
1898 
1899 		write_lock_bh(&sk->sk_callback_lock);
1900 
1901 		xs_save_old_callbacks(transport, sk);
1902 
1903 		sk->sk_user_data = xprt;
1904 		sk->sk_data_ready = xs_local_data_ready;
1905 		sk->sk_write_space = xs_udp_write_space;
1906 		sk->sk_error_report = xs_error_report;
1907 		sk->sk_allocation = GFP_ATOMIC;
1908 
1909 		xprt_clear_connected(xprt);
1910 
1911 		/* Reset to new socket */
1912 		transport->sock = sock;
1913 		transport->inet = sk;
1914 
1915 		write_unlock_bh(&sk->sk_callback_lock);
1916 	}
1917 
1918 	/* Tell the socket layer to start connecting... */
1919 	xprt->stat.connect_count++;
1920 	xprt->stat.connect_start = jiffies;
1921 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1922 }
1923 
1924 /**
1925  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1926  * @xprt: RPC transport to connect
1927  * @transport: socket transport to connect
1928  * @create_sock: function to create a socket of the correct type
1929  */
1930 static int xs_local_setup_socket(struct sock_xprt *transport)
1931 {
1932 	struct rpc_xprt *xprt = &transport->xprt;
1933 	struct socket *sock;
1934 	int status = -EIO;
1935 
1936 	current->flags |= PF_FSTRANS;
1937 
1938 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1939 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1940 					SOCK_STREAM, 0, &sock, 1);
1941 	if (status < 0) {
1942 		dprintk("RPC:       can't create AF_LOCAL "
1943 			"transport socket (%d).\n", -status);
1944 		goto out;
1945 	}
1946 	xs_reclassify_socketu(sock);
1947 
1948 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1949 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1950 
1951 	status = xs_local_finish_connecting(xprt, sock);
1952 	trace_rpc_socket_connect(xprt, sock, status);
1953 	switch (status) {
1954 	case 0:
1955 		dprintk("RPC:       xprt %p connected to %s\n",
1956 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1957 		xprt_set_connected(xprt);
1958 		break;
1959 	case -ENOENT:
1960 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1961 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1962 		break;
1963 	case -ECONNREFUSED:
1964 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1965 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1966 		break;
1967 	default:
1968 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1969 				__func__, -status,
1970 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1971 	}
1972 
1973 out:
1974 	xprt_clear_connecting(xprt);
1975 	xprt_wake_pending_tasks(xprt, status);
1976 	current->flags &= ~PF_FSTRANS;
1977 	return status;
1978 }
1979 
1980 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1981 {
1982 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1983 	int ret;
1984 
1985 	 if (RPC_IS_ASYNC(task)) {
1986 		/*
1987 		 * We want the AF_LOCAL connect to be resolved in the
1988 		 * filesystem namespace of the process making the rpc
1989 		 * call.  Thus we connect synchronously.
1990 		 *
1991 		 * If we want to support asynchronous AF_LOCAL calls,
1992 		 * we'll need to figure out how to pass a namespace to
1993 		 * connect.
1994 		 */
1995 		rpc_exit(task, -ENOTCONN);
1996 		return;
1997 	}
1998 	ret = xs_local_setup_socket(transport);
1999 	if (ret && !RPC_IS_SOFTCONN(task))
2000 		msleep_interruptible(15000);
2001 }
2002 
2003 #ifdef CONFIG_SUNRPC_SWAP
2004 static void xs_set_memalloc(struct rpc_xprt *xprt)
2005 {
2006 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2007 			xprt);
2008 
2009 	if (xprt->swapper)
2010 		sk_set_memalloc(transport->inet);
2011 }
2012 
2013 /**
2014  * xs_swapper - Tag this transport as being used for swap.
2015  * @xprt: transport to tag
2016  * @enable: enable/disable
2017  *
2018  */
2019 int xs_swapper(struct rpc_xprt *xprt, int enable)
2020 {
2021 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2022 			xprt);
2023 	int err = 0;
2024 
2025 	if (enable) {
2026 		xprt->swapper++;
2027 		xs_set_memalloc(xprt);
2028 	} else if (xprt->swapper) {
2029 		xprt->swapper--;
2030 		sk_clear_memalloc(transport->inet);
2031 	}
2032 
2033 	return err;
2034 }
2035 EXPORT_SYMBOL_GPL(xs_swapper);
2036 #else
2037 static void xs_set_memalloc(struct rpc_xprt *xprt)
2038 {
2039 }
2040 #endif
2041 
2042 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2043 {
2044 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2045 
2046 	if (!transport->inet) {
2047 		struct sock *sk = sock->sk;
2048 
2049 		write_lock_bh(&sk->sk_callback_lock);
2050 
2051 		xs_save_old_callbacks(transport, sk);
2052 
2053 		sk->sk_user_data = xprt;
2054 		sk->sk_data_ready = xs_udp_data_ready;
2055 		sk->sk_write_space = xs_udp_write_space;
2056 		sk->sk_no_check = UDP_CSUM_NORCV;
2057 		sk->sk_allocation = GFP_ATOMIC;
2058 
2059 		xprt_set_connected(xprt);
2060 
2061 		/* Reset to new socket */
2062 		transport->sock = sock;
2063 		transport->inet = sk;
2064 
2065 		xs_set_memalloc(xprt);
2066 
2067 		write_unlock_bh(&sk->sk_callback_lock);
2068 	}
2069 	xs_udp_do_set_buffer_size(xprt);
2070 }
2071 
2072 static void xs_udp_setup_socket(struct work_struct *work)
2073 {
2074 	struct sock_xprt *transport =
2075 		container_of(work, struct sock_xprt, connect_worker.work);
2076 	struct rpc_xprt *xprt = &transport->xprt;
2077 	struct socket *sock = transport->sock;
2078 	int status = -EIO;
2079 
2080 	current->flags |= PF_FSTRANS;
2081 
2082 	/* Start by resetting any existing state */
2083 	xs_reset_transport(transport);
2084 	sock = xs_create_sock(xprt, transport,
2085 			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2086 	if (IS_ERR(sock))
2087 		goto out;
2088 
2089 	dprintk("RPC:       worker connecting xprt %p via %s to "
2090 				"%s (port %s)\n", xprt,
2091 			xprt->address_strings[RPC_DISPLAY_PROTO],
2092 			xprt->address_strings[RPC_DISPLAY_ADDR],
2093 			xprt->address_strings[RPC_DISPLAY_PORT]);
2094 
2095 	xs_udp_finish_connecting(xprt, sock);
2096 	trace_rpc_socket_connect(xprt, sock, 0);
2097 	status = 0;
2098 out:
2099 	xprt_clear_connecting(xprt);
2100 	xprt_wake_pending_tasks(xprt, status);
2101 	current->flags &= ~PF_FSTRANS;
2102 }
2103 
2104 /*
2105  * We need to preserve the port number so the reply cache on the server can
2106  * find our cached RPC replies when we get around to reconnecting.
2107  */
2108 static void xs_abort_connection(struct sock_xprt *transport)
2109 {
2110 	int result;
2111 	struct sockaddr any;
2112 
2113 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2114 
2115 	/*
2116 	 * Disconnect the transport socket by doing a connect operation
2117 	 * with AF_UNSPEC.  This should return immediately...
2118 	 */
2119 	memset(&any, 0, sizeof(any));
2120 	any.sa_family = AF_UNSPEC;
2121 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2122 	trace_rpc_socket_reset_connection(&transport->xprt,
2123 			transport->sock, result);
2124 	if (!result)
2125 		xs_sock_reset_connection_flags(&transport->xprt);
2126 	dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2127 }
2128 
2129 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2130 {
2131 	unsigned int state = transport->inet->sk_state;
2132 
2133 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2134 		/* we don't need to abort the connection if the socket
2135 		 * hasn't undergone a shutdown
2136 		 */
2137 		if (transport->inet->sk_shutdown == 0)
2138 			return;
2139 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2140 				__func__, transport->inet->sk_shutdown);
2141 	}
2142 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2143 		/* we don't need to abort the connection if the socket
2144 		 * hasn't undergone a shutdown
2145 		 */
2146 		if (transport->inet->sk_shutdown == 0)
2147 			return;
2148 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2149 				"sk_shutdown set to %d\n",
2150 				__func__, transport->inet->sk_shutdown);
2151 	}
2152 	xs_abort_connection(transport);
2153 }
2154 
2155 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2156 {
2157 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2158 	int ret = -ENOTCONN;
2159 
2160 	if (!transport->inet) {
2161 		struct sock *sk = sock->sk;
2162 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2163 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2164 		unsigned int opt_on = 1;
2165 
2166 		/* TCP Keepalive options */
2167 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2168 				(char *)&opt_on, sizeof(opt_on));
2169 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2170 				(char *)&keepidle, sizeof(keepidle));
2171 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2172 				(char *)&keepidle, sizeof(keepidle));
2173 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2174 				(char *)&keepcnt, sizeof(keepcnt));
2175 
2176 		write_lock_bh(&sk->sk_callback_lock);
2177 
2178 		xs_save_old_callbacks(transport, sk);
2179 
2180 		sk->sk_user_data = xprt;
2181 		sk->sk_data_ready = xs_tcp_data_ready;
2182 		sk->sk_state_change = xs_tcp_state_change;
2183 		sk->sk_write_space = xs_tcp_write_space;
2184 		sk->sk_error_report = xs_error_report;
2185 		sk->sk_allocation = GFP_ATOMIC;
2186 
2187 		/* socket options */
2188 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2189 		sock_reset_flag(sk, SOCK_LINGER);
2190 		tcp_sk(sk)->linger2 = 0;
2191 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2192 
2193 		xprt_clear_connected(xprt);
2194 
2195 		/* Reset to new socket */
2196 		transport->sock = sock;
2197 		transport->inet = sk;
2198 
2199 		write_unlock_bh(&sk->sk_callback_lock);
2200 	}
2201 
2202 	if (!xprt_bound(xprt))
2203 		goto out;
2204 
2205 	xs_set_memalloc(xprt);
2206 
2207 	/* Tell the socket layer to start connecting... */
2208 	xprt->stat.connect_count++;
2209 	xprt->stat.connect_start = jiffies;
2210 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2211 	switch (ret) {
2212 	case 0:
2213 	case -EINPROGRESS:
2214 		/* SYN_SENT! */
2215 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2216 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2217 	}
2218 out:
2219 	return ret;
2220 }
2221 
2222 /**
2223  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2224  * @xprt: RPC transport to connect
2225  * @transport: socket transport to connect
2226  * @create_sock: function to create a socket of the correct type
2227  *
2228  * Invoked by a work queue tasklet.
2229  */
2230 static void xs_tcp_setup_socket(struct work_struct *work)
2231 {
2232 	struct sock_xprt *transport =
2233 		container_of(work, struct sock_xprt, connect_worker.work);
2234 	struct socket *sock = transport->sock;
2235 	struct rpc_xprt *xprt = &transport->xprt;
2236 	int status = -EIO;
2237 
2238 	current->flags |= PF_FSTRANS;
2239 
2240 	if (!sock) {
2241 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2242 		sock = xs_create_sock(xprt, transport,
2243 				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2244 		if (IS_ERR(sock)) {
2245 			status = PTR_ERR(sock);
2246 			goto out;
2247 		}
2248 	} else {
2249 		int abort_and_exit;
2250 
2251 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2252 				&xprt->state);
2253 		/* "close" the socket, preserving the local port */
2254 		xs_tcp_reuse_connection(transport);
2255 
2256 		if (abort_and_exit)
2257 			goto out_eagain;
2258 	}
2259 
2260 	dprintk("RPC:       worker connecting xprt %p via %s to "
2261 				"%s (port %s)\n", xprt,
2262 			xprt->address_strings[RPC_DISPLAY_PROTO],
2263 			xprt->address_strings[RPC_DISPLAY_ADDR],
2264 			xprt->address_strings[RPC_DISPLAY_PORT]);
2265 
2266 	status = xs_tcp_finish_connecting(xprt, sock);
2267 	trace_rpc_socket_connect(xprt, sock, status);
2268 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2269 			xprt, -status, xprt_connected(xprt),
2270 			sock->sk->sk_state);
2271 	switch (status) {
2272 	default:
2273 		printk("%s: connect returned unhandled error %d\n",
2274 			__func__, status);
2275 	case -EADDRNOTAVAIL:
2276 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2277 		 * and retry
2278 		 */
2279 		xs_tcp_force_close(xprt);
2280 		break;
2281 	case 0:
2282 	case -EINPROGRESS:
2283 	case -EALREADY:
2284 		xprt_clear_connecting(xprt);
2285 		current->flags &= ~PF_FSTRANS;
2286 		return;
2287 	case -EINVAL:
2288 		/* Happens, for instance, if the user specified a link
2289 		 * local IPv6 address without a scope-id.
2290 		 */
2291 	case -ECONNREFUSED:
2292 	case -ECONNRESET:
2293 	case -ENETUNREACH:
2294 		/* retry with existing socket, after a delay */
2295 		goto out;
2296 	}
2297 out_eagain:
2298 	status = -EAGAIN;
2299 out:
2300 	xprt_clear_connecting(xprt);
2301 	xprt_wake_pending_tasks(xprt, status);
2302 	current->flags &= ~PF_FSTRANS;
2303 }
2304 
2305 /**
2306  * xs_connect - connect a socket to a remote endpoint
2307  * @xprt: pointer to transport structure
2308  * @task: address of RPC task that manages state of connect request
2309  *
2310  * TCP: If the remote end dropped the connection, delay reconnecting.
2311  *
2312  * UDP socket connects are synchronous, but we use a work queue anyway
2313  * to guarantee that even unprivileged user processes can set up a
2314  * socket on a privileged port.
2315  *
2316  * If a UDP socket connect fails, the delay behavior here prevents
2317  * retry floods (hard mounts).
2318  */
2319 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2320 {
2321 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2322 
2323 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2324 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2325 				"seconds\n",
2326 				xprt, xprt->reestablish_timeout / HZ);
2327 		queue_delayed_work(rpciod_workqueue,
2328 				   &transport->connect_worker,
2329 				   xprt->reestablish_timeout);
2330 		xprt->reestablish_timeout <<= 1;
2331 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2332 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2333 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2334 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2335 	} else {
2336 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2337 		queue_delayed_work(rpciod_workqueue,
2338 				   &transport->connect_worker, 0);
2339 	}
2340 }
2341 
2342 /**
2343  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2344  * @xprt: rpc_xprt struct containing statistics
2345  * @seq: output file
2346  *
2347  */
2348 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2349 {
2350 	long idle_time = 0;
2351 
2352 	if (xprt_connected(xprt))
2353 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2354 
2355 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2356 			"%llu %llu %lu %llu %llu\n",
2357 			xprt->stat.bind_count,
2358 			xprt->stat.connect_count,
2359 			xprt->stat.connect_time,
2360 			idle_time,
2361 			xprt->stat.sends,
2362 			xprt->stat.recvs,
2363 			xprt->stat.bad_xids,
2364 			xprt->stat.req_u,
2365 			xprt->stat.bklog_u,
2366 			xprt->stat.max_slots,
2367 			xprt->stat.sending_u,
2368 			xprt->stat.pending_u);
2369 }
2370 
2371 /**
2372  * xs_udp_print_stats - display UDP socket-specifc stats
2373  * @xprt: rpc_xprt struct containing statistics
2374  * @seq: output file
2375  *
2376  */
2377 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2378 {
2379 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2380 
2381 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2382 			"%lu %llu %llu\n",
2383 			transport->srcport,
2384 			xprt->stat.bind_count,
2385 			xprt->stat.sends,
2386 			xprt->stat.recvs,
2387 			xprt->stat.bad_xids,
2388 			xprt->stat.req_u,
2389 			xprt->stat.bklog_u,
2390 			xprt->stat.max_slots,
2391 			xprt->stat.sending_u,
2392 			xprt->stat.pending_u);
2393 }
2394 
2395 /**
2396  * xs_tcp_print_stats - display TCP socket-specifc stats
2397  * @xprt: rpc_xprt struct containing statistics
2398  * @seq: output file
2399  *
2400  */
2401 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2402 {
2403 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2404 	long idle_time = 0;
2405 
2406 	if (xprt_connected(xprt))
2407 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2408 
2409 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2410 			"%llu %llu %lu %llu %llu\n",
2411 			transport->srcport,
2412 			xprt->stat.bind_count,
2413 			xprt->stat.connect_count,
2414 			xprt->stat.connect_time,
2415 			idle_time,
2416 			xprt->stat.sends,
2417 			xprt->stat.recvs,
2418 			xprt->stat.bad_xids,
2419 			xprt->stat.req_u,
2420 			xprt->stat.bklog_u,
2421 			xprt->stat.max_slots,
2422 			xprt->stat.sending_u,
2423 			xprt->stat.pending_u);
2424 }
2425 
2426 /*
2427  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2428  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2429  * to use the server side send routines.
2430  */
2431 static void *bc_malloc(struct rpc_task *task, size_t size)
2432 {
2433 	struct page *page;
2434 	struct rpc_buffer *buf;
2435 
2436 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2437 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2438 		return NULL;
2439 
2440 	page = alloc_page(GFP_KERNEL);
2441 	if (!page)
2442 		return NULL;
2443 
2444 	buf = page_address(page);
2445 	buf->len = PAGE_SIZE;
2446 
2447 	return buf->data;
2448 }
2449 
2450 /*
2451  * Free the space allocated in the bc_alloc routine
2452  */
2453 static void bc_free(void *buffer)
2454 {
2455 	struct rpc_buffer *buf;
2456 
2457 	if (!buffer)
2458 		return;
2459 
2460 	buf = container_of(buffer, struct rpc_buffer, data);
2461 	free_page((unsigned long)buf);
2462 }
2463 
2464 /*
2465  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2466  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2467  */
2468 static int bc_sendto(struct rpc_rqst *req)
2469 {
2470 	int len;
2471 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2472 	struct rpc_xprt *xprt = req->rq_xprt;
2473 	struct sock_xprt *transport =
2474 				container_of(xprt, struct sock_xprt, xprt);
2475 	struct socket *sock = transport->sock;
2476 	unsigned long headoff;
2477 	unsigned long tailoff;
2478 
2479 	xs_encode_stream_record_marker(xbufp);
2480 
2481 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2482 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2483 	len = svc_send_common(sock, xbufp,
2484 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2485 			      xbufp->tail[0].iov_base, tailoff);
2486 
2487 	if (len != xbufp->len) {
2488 		printk(KERN_NOTICE "Error sending entire callback!\n");
2489 		len = -EAGAIN;
2490 	}
2491 
2492 	return len;
2493 }
2494 
2495 /*
2496  * The send routine. Borrows from svc_send
2497  */
2498 static int bc_send_request(struct rpc_task *task)
2499 {
2500 	struct rpc_rqst *req = task->tk_rqstp;
2501 	struct svc_xprt	*xprt;
2502 	u32                     len;
2503 
2504 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2505 	/*
2506 	 * Get the server socket associated with this callback xprt
2507 	 */
2508 	xprt = req->rq_xprt->bc_xprt;
2509 
2510 	/*
2511 	 * Grab the mutex to serialize data as the connection is shared
2512 	 * with the fore channel
2513 	 */
2514 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2515 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2516 		if (!mutex_trylock(&xprt->xpt_mutex))
2517 			return -EAGAIN;
2518 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2519 	}
2520 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2521 		len = -ENOTCONN;
2522 	else
2523 		len = bc_sendto(req);
2524 	mutex_unlock(&xprt->xpt_mutex);
2525 
2526 	if (len > 0)
2527 		len = 0;
2528 
2529 	return len;
2530 }
2531 
2532 /*
2533  * The close routine. Since this is client initiated, we do nothing
2534  */
2535 
2536 static void bc_close(struct rpc_xprt *xprt)
2537 {
2538 }
2539 
2540 /*
2541  * The xprt destroy routine. Again, because this connection is client
2542  * initiated, we do nothing
2543  */
2544 
2545 static void bc_destroy(struct rpc_xprt *xprt)
2546 {
2547 }
2548 
2549 static struct rpc_xprt_ops xs_local_ops = {
2550 	.reserve_xprt		= xprt_reserve_xprt,
2551 	.release_xprt		= xs_tcp_release_xprt,
2552 	.alloc_slot		= xprt_alloc_slot,
2553 	.rpcbind		= xs_local_rpcbind,
2554 	.set_port		= xs_local_set_port,
2555 	.connect		= xs_local_connect,
2556 	.buf_alloc		= rpc_malloc,
2557 	.buf_free		= rpc_free,
2558 	.send_request		= xs_local_send_request,
2559 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2560 	.close			= xs_close,
2561 	.destroy		= xs_destroy,
2562 	.print_stats		= xs_local_print_stats,
2563 };
2564 
2565 static struct rpc_xprt_ops xs_udp_ops = {
2566 	.set_buffer_size	= xs_udp_set_buffer_size,
2567 	.reserve_xprt		= xprt_reserve_xprt_cong,
2568 	.release_xprt		= xprt_release_xprt_cong,
2569 	.alloc_slot		= xprt_alloc_slot,
2570 	.rpcbind		= rpcb_getport_async,
2571 	.set_port		= xs_set_port,
2572 	.connect		= xs_connect,
2573 	.buf_alloc		= rpc_malloc,
2574 	.buf_free		= rpc_free,
2575 	.send_request		= xs_udp_send_request,
2576 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2577 	.timer			= xs_udp_timer,
2578 	.release_request	= xprt_release_rqst_cong,
2579 	.close			= xs_close,
2580 	.destroy		= xs_destroy,
2581 	.print_stats		= xs_udp_print_stats,
2582 };
2583 
2584 static struct rpc_xprt_ops xs_tcp_ops = {
2585 	.reserve_xprt		= xprt_reserve_xprt,
2586 	.release_xprt		= xs_tcp_release_xprt,
2587 	.alloc_slot		= xprt_lock_and_alloc_slot,
2588 	.rpcbind		= rpcb_getport_async,
2589 	.set_port		= xs_set_port,
2590 	.connect		= xs_connect,
2591 	.buf_alloc		= rpc_malloc,
2592 	.buf_free		= rpc_free,
2593 	.send_request		= xs_tcp_send_request,
2594 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2595 	.close			= xs_tcp_close,
2596 	.destroy		= xs_destroy,
2597 	.print_stats		= xs_tcp_print_stats,
2598 };
2599 
2600 /*
2601  * The rpc_xprt_ops for the server backchannel
2602  */
2603 
2604 static struct rpc_xprt_ops bc_tcp_ops = {
2605 	.reserve_xprt		= xprt_reserve_xprt,
2606 	.release_xprt		= xprt_release_xprt,
2607 	.alloc_slot		= xprt_alloc_slot,
2608 	.buf_alloc		= bc_malloc,
2609 	.buf_free		= bc_free,
2610 	.send_request		= bc_send_request,
2611 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2612 	.close			= bc_close,
2613 	.destroy		= bc_destroy,
2614 	.print_stats		= xs_tcp_print_stats,
2615 };
2616 
2617 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2618 {
2619 	static const struct sockaddr_in sin = {
2620 		.sin_family		= AF_INET,
2621 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2622 	};
2623 	static const struct sockaddr_in6 sin6 = {
2624 		.sin6_family		= AF_INET6,
2625 		.sin6_addr		= IN6ADDR_ANY_INIT,
2626 	};
2627 
2628 	switch (family) {
2629 	case AF_LOCAL:
2630 		break;
2631 	case AF_INET:
2632 		memcpy(sap, &sin, sizeof(sin));
2633 		break;
2634 	case AF_INET6:
2635 		memcpy(sap, &sin6, sizeof(sin6));
2636 		break;
2637 	default:
2638 		dprintk("RPC:       %s: Bad address family\n", __func__);
2639 		return -EAFNOSUPPORT;
2640 	}
2641 	return 0;
2642 }
2643 
2644 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2645 				      unsigned int slot_table_size,
2646 				      unsigned int max_slot_table_size)
2647 {
2648 	struct rpc_xprt *xprt;
2649 	struct sock_xprt *new;
2650 
2651 	if (args->addrlen > sizeof(xprt->addr)) {
2652 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2653 		return ERR_PTR(-EBADF);
2654 	}
2655 
2656 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2657 			max_slot_table_size);
2658 	if (xprt == NULL) {
2659 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2660 				"rpc_xprt\n");
2661 		return ERR_PTR(-ENOMEM);
2662 	}
2663 
2664 	new = container_of(xprt, struct sock_xprt, xprt);
2665 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2666 	xprt->addrlen = args->addrlen;
2667 	if (args->srcaddr)
2668 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2669 	else {
2670 		int err;
2671 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2672 					(struct sockaddr *)&new->srcaddr);
2673 		if (err != 0) {
2674 			xprt_free(xprt);
2675 			return ERR_PTR(err);
2676 		}
2677 	}
2678 
2679 	return xprt;
2680 }
2681 
2682 static const struct rpc_timeout xs_local_default_timeout = {
2683 	.to_initval = 10 * HZ,
2684 	.to_maxval = 10 * HZ,
2685 	.to_retries = 2,
2686 };
2687 
2688 /**
2689  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2690  * @args: rpc transport creation arguments
2691  *
2692  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2693  */
2694 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2695 {
2696 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2697 	struct sock_xprt *transport;
2698 	struct rpc_xprt *xprt;
2699 	struct rpc_xprt *ret;
2700 
2701 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2702 			xprt_max_tcp_slot_table_entries);
2703 	if (IS_ERR(xprt))
2704 		return xprt;
2705 	transport = container_of(xprt, struct sock_xprt, xprt);
2706 
2707 	xprt->prot = 0;
2708 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2709 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2710 
2711 	xprt->bind_timeout = XS_BIND_TO;
2712 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2713 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2714 
2715 	xprt->ops = &xs_local_ops;
2716 	xprt->timeout = &xs_local_default_timeout;
2717 
2718 	INIT_DELAYED_WORK(&transport->connect_worker,
2719 			xs_dummy_setup_socket);
2720 
2721 	switch (sun->sun_family) {
2722 	case AF_LOCAL:
2723 		if (sun->sun_path[0] != '/') {
2724 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2725 					sun->sun_path);
2726 			ret = ERR_PTR(-EINVAL);
2727 			goto out_err;
2728 		}
2729 		xprt_set_bound(xprt);
2730 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2731 		ret = ERR_PTR(xs_local_setup_socket(transport));
2732 		if (ret)
2733 			goto out_err;
2734 		break;
2735 	default:
2736 		ret = ERR_PTR(-EAFNOSUPPORT);
2737 		goto out_err;
2738 	}
2739 
2740 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2741 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2742 
2743 	if (try_module_get(THIS_MODULE))
2744 		return xprt;
2745 	ret = ERR_PTR(-EINVAL);
2746 out_err:
2747 	xprt_free(xprt);
2748 	return ret;
2749 }
2750 
2751 static const struct rpc_timeout xs_udp_default_timeout = {
2752 	.to_initval = 5 * HZ,
2753 	.to_maxval = 30 * HZ,
2754 	.to_increment = 5 * HZ,
2755 	.to_retries = 5,
2756 };
2757 
2758 /**
2759  * xs_setup_udp - Set up transport to use a UDP socket
2760  * @args: rpc transport creation arguments
2761  *
2762  */
2763 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2764 {
2765 	struct sockaddr *addr = args->dstaddr;
2766 	struct rpc_xprt *xprt;
2767 	struct sock_xprt *transport;
2768 	struct rpc_xprt *ret;
2769 
2770 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2771 			xprt_udp_slot_table_entries);
2772 	if (IS_ERR(xprt))
2773 		return xprt;
2774 	transport = container_of(xprt, struct sock_xprt, xprt);
2775 
2776 	xprt->prot = IPPROTO_UDP;
2777 	xprt->tsh_size = 0;
2778 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2779 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2780 
2781 	xprt->bind_timeout = XS_BIND_TO;
2782 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2783 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2784 
2785 	xprt->ops = &xs_udp_ops;
2786 
2787 	xprt->timeout = &xs_udp_default_timeout;
2788 
2789 	switch (addr->sa_family) {
2790 	case AF_INET:
2791 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2792 			xprt_set_bound(xprt);
2793 
2794 		INIT_DELAYED_WORK(&transport->connect_worker,
2795 					xs_udp_setup_socket);
2796 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2797 		break;
2798 	case AF_INET6:
2799 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2800 			xprt_set_bound(xprt);
2801 
2802 		INIT_DELAYED_WORK(&transport->connect_worker,
2803 					xs_udp_setup_socket);
2804 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2805 		break;
2806 	default:
2807 		ret = ERR_PTR(-EAFNOSUPPORT);
2808 		goto out_err;
2809 	}
2810 
2811 	if (xprt_bound(xprt))
2812 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2813 				xprt->address_strings[RPC_DISPLAY_ADDR],
2814 				xprt->address_strings[RPC_DISPLAY_PORT],
2815 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2816 	else
2817 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2818 				xprt->address_strings[RPC_DISPLAY_ADDR],
2819 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2820 
2821 	if (try_module_get(THIS_MODULE))
2822 		return xprt;
2823 	ret = ERR_PTR(-EINVAL);
2824 out_err:
2825 	xprt_free(xprt);
2826 	return ret;
2827 }
2828 
2829 static const struct rpc_timeout xs_tcp_default_timeout = {
2830 	.to_initval = 60 * HZ,
2831 	.to_maxval = 60 * HZ,
2832 	.to_retries = 2,
2833 };
2834 
2835 /**
2836  * xs_setup_tcp - Set up transport to use a TCP socket
2837  * @args: rpc transport creation arguments
2838  *
2839  */
2840 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2841 {
2842 	struct sockaddr *addr = args->dstaddr;
2843 	struct rpc_xprt *xprt;
2844 	struct sock_xprt *transport;
2845 	struct rpc_xprt *ret;
2846 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2847 
2848 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2849 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2850 
2851 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2852 			max_slot_table_size);
2853 	if (IS_ERR(xprt))
2854 		return xprt;
2855 	transport = container_of(xprt, struct sock_xprt, xprt);
2856 
2857 	xprt->prot = IPPROTO_TCP;
2858 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2859 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2860 
2861 	xprt->bind_timeout = XS_BIND_TO;
2862 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2863 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2864 
2865 	xprt->ops = &xs_tcp_ops;
2866 	xprt->timeout = &xs_tcp_default_timeout;
2867 
2868 	switch (addr->sa_family) {
2869 	case AF_INET:
2870 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2871 			xprt_set_bound(xprt);
2872 
2873 		INIT_DELAYED_WORK(&transport->connect_worker,
2874 					xs_tcp_setup_socket);
2875 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2876 		break;
2877 	case AF_INET6:
2878 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2879 			xprt_set_bound(xprt);
2880 
2881 		INIT_DELAYED_WORK(&transport->connect_worker,
2882 					xs_tcp_setup_socket);
2883 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2884 		break;
2885 	default:
2886 		ret = ERR_PTR(-EAFNOSUPPORT);
2887 		goto out_err;
2888 	}
2889 
2890 	if (xprt_bound(xprt))
2891 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2892 				xprt->address_strings[RPC_DISPLAY_ADDR],
2893 				xprt->address_strings[RPC_DISPLAY_PORT],
2894 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2895 	else
2896 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2897 				xprt->address_strings[RPC_DISPLAY_ADDR],
2898 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2899 
2900 
2901 	if (try_module_get(THIS_MODULE))
2902 		return xprt;
2903 	ret = ERR_PTR(-EINVAL);
2904 out_err:
2905 	xprt_free(xprt);
2906 	return ret;
2907 }
2908 
2909 /**
2910  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2911  * @args: rpc transport creation arguments
2912  *
2913  */
2914 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2915 {
2916 	struct sockaddr *addr = args->dstaddr;
2917 	struct rpc_xprt *xprt;
2918 	struct sock_xprt *transport;
2919 	struct svc_sock *bc_sock;
2920 	struct rpc_xprt *ret;
2921 
2922 	if (args->bc_xprt->xpt_bc_xprt) {
2923 		/*
2924 		 * This server connection already has a backchannel
2925 		 * transport; we can't create a new one, as we wouldn't
2926 		 * be able to match replies based on xid any more.  So,
2927 		 * reuse the already-existing one:
2928 		 */
2929 		 return args->bc_xprt->xpt_bc_xprt;
2930 	}
2931 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2932 			xprt_tcp_slot_table_entries);
2933 	if (IS_ERR(xprt))
2934 		return xprt;
2935 	transport = container_of(xprt, struct sock_xprt, xprt);
2936 
2937 	xprt->prot = IPPROTO_TCP;
2938 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2939 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2940 	xprt->timeout = &xs_tcp_default_timeout;
2941 
2942 	/* backchannel */
2943 	xprt_set_bound(xprt);
2944 	xprt->bind_timeout = 0;
2945 	xprt->reestablish_timeout = 0;
2946 	xprt->idle_timeout = 0;
2947 
2948 	xprt->ops = &bc_tcp_ops;
2949 
2950 	switch (addr->sa_family) {
2951 	case AF_INET:
2952 		xs_format_peer_addresses(xprt, "tcp",
2953 					 RPCBIND_NETID_TCP);
2954 		break;
2955 	case AF_INET6:
2956 		xs_format_peer_addresses(xprt, "tcp",
2957 				   RPCBIND_NETID_TCP6);
2958 		break;
2959 	default:
2960 		ret = ERR_PTR(-EAFNOSUPPORT);
2961 		goto out_err;
2962 	}
2963 
2964 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2965 			xprt->address_strings[RPC_DISPLAY_ADDR],
2966 			xprt->address_strings[RPC_DISPLAY_PORT],
2967 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2968 
2969 	/*
2970 	 * Once we've associated a backchannel xprt with a connection,
2971 	 * we want to keep it around as long as the connection lasts,
2972 	 * in case we need to start using it for a backchannel again;
2973 	 * this reference won't be dropped until bc_xprt is destroyed.
2974 	 */
2975 	xprt_get(xprt);
2976 	args->bc_xprt->xpt_bc_xprt = xprt;
2977 	xprt->bc_xprt = args->bc_xprt;
2978 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2979 	transport->sock = bc_sock->sk_sock;
2980 	transport->inet = bc_sock->sk_sk;
2981 
2982 	/*
2983 	 * Since we don't want connections for the backchannel, we set
2984 	 * the xprt status to connected
2985 	 */
2986 	xprt_set_connected(xprt);
2987 
2988 
2989 	if (try_module_get(THIS_MODULE))
2990 		return xprt;
2991 	xprt_put(xprt);
2992 	ret = ERR_PTR(-EINVAL);
2993 out_err:
2994 	xprt_free(xprt);
2995 	return ret;
2996 }
2997 
2998 static struct xprt_class	xs_local_transport = {
2999 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3000 	.name		= "named UNIX socket",
3001 	.owner		= THIS_MODULE,
3002 	.ident		= XPRT_TRANSPORT_LOCAL,
3003 	.setup		= xs_setup_local,
3004 };
3005 
3006 static struct xprt_class	xs_udp_transport = {
3007 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3008 	.name		= "udp",
3009 	.owner		= THIS_MODULE,
3010 	.ident		= XPRT_TRANSPORT_UDP,
3011 	.setup		= xs_setup_udp,
3012 };
3013 
3014 static struct xprt_class	xs_tcp_transport = {
3015 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3016 	.name		= "tcp",
3017 	.owner		= THIS_MODULE,
3018 	.ident		= XPRT_TRANSPORT_TCP,
3019 	.setup		= xs_setup_tcp,
3020 };
3021 
3022 static struct xprt_class	xs_bc_tcp_transport = {
3023 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3024 	.name		= "tcp NFSv4.1 backchannel",
3025 	.owner		= THIS_MODULE,
3026 	.ident		= XPRT_TRANSPORT_BC_TCP,
3027 	.setup		= xs_setup_bc_tcp,
3028 };
3029 
3030 /**
3031  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3032  *
3033  */
3034 int init_socket_xprt(void)
3035 {
3036 #ifdef RPC_DEBUG
3037 	if (!sunrpc_table_header)
3038 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3039 #endif
3040 
3041 	xprt_register_transport(&xs_local_transport);
3042 	xprt_register_transport(&xs_udp_transport);
3043 	xprt_register_transport(&xs_tcp_transport);
3044 	xprt_register_transport(&xs_bc_tcp_transport);
3045 
3046 	return 0;
3047 }
3048 
3049 /**
3050  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3051  *
3052  */
3053 void cleanup_socket_xprt(void)
3054 {
3055 #ifdef RPC_DEBUG
3056 	if (sunrpc_table_header) {
3057 		unregister_sysctl_table(sunrpc_table_header);
3058 		sunrpc_table_header = NULL;
3059 	}
3060 #endif
3061 
3062 	xprt_unregister_transport(&xs_local_transport);
3063 	xprt_unregister_transport(&xs_udp_transport);
3064 	xprt_unregister_transport(&xs_tcp_transport);
3065 	xprt_unregister_transport(&xs_bc_tcp_transport);
3066 }
3067 
3068 static int param_set_uint_minmax(const char *val,
3069 		const struct kernel_param *kp,
3070 		unsigned int min, unsigned int max)
3071 {
3072 	unsigned long num;
3073 	int ret;
3074 
3075 	if (!val)
3076 		return -EINVAL;
3077 	ret = strict_strtoul(val, 0, &num);
3078 	if (ret == -EINVAL || num < min || num > max)
3079 		return -EINVAL;
3080 	*((unsigned int *)kp->arg) = num;
3081 	return 0;
3082 }
3083 
3084 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3085 {
3086 	return param_set_uint_minmax(val, kp,
3087 			RPC_MIN_RESVPORT,
3088 			RPC_MAX_RESVPORT);
3089 }
3090 
3091 static struct kernel_param_ops param_ops_portnr = {
3092 	.set = param_set_portnr,
3093 	.get = param_get_uint,
3094 };
3095 
3096 #define param_check_portnr(name, p) \
3097 	__param_check(name, p, unsigned int);
3098 
3099 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3100 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3101 
3102 static int param_set_slot_table_size(const char *val,
3103 				     const struct kernel_param *kp)
3104 {
3105 	return param_set_uint_minmax(val, kp,
3106 			RPC_MIN_SLOT_TABLE,
3107 			RPC_MAX_SLOT_TABLE);
3108 }
3109 
3110 static struct kernel_param_ops param_ops_slot_table_size = {
3111 	.set = param_set_slot_table_size,
3112 	.get = param_get_uint,
3113 };
3114 
3115 #define param_check_slot_table_size(name, p) \
3116 	__param_check(name, p, unsigned int);
3117 
3118 static int param_set_max_slot_table_size(const char *val,
3119 				     const struct kernel_param *kp)
3120 {
3121 	return param_set_uint_minmax(val, kp,
3122 			RPC_MIN_SLOT_TABLE,
3123 			RPC_MAX_SLOT_TABLE_LIMIT);
3124 }
3125 
3126 static struct kernel_param_ops param_ops_max_slot_table_size = {
3127 	.set = param_set_max_slot_table_size,
3128 	.get = param_get_uint,
3129 };
3130 
3131 #define param_check_max_slot_table_size(name, p) \
3132 	__param_check(name, p, unsigned int);
3133 
3134 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3135 		   slot_table_size, 0644);
3136 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3137 		   max_slot_table_size, 0644);
3138 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3139 		   slot_table_size, 0644);
3140 
3141