xref: /linux/net/sunrpc/xprtsock.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 *);
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 -ENOBUFS:
598 	case -EAGAIN:
599 		status = xs_nospace(task);
600 		break;
601 	default:
602 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
603 			-status);
604 	case -EPIPE:
605 		xs_close(xprt);
606 		status = -ENOTCONN;
607 	}
608 
609 	return status;
610 }
611 
612 /**
613  * xs_udp_send_request - write an RPC request to a UDP socket
614  * @task: address of RPC task that manages the state of an RPC request
615  *
616  * Return values:
617  *        0:	The request has been sent
618  *   EAGAIN:	The socket was blocked, please call again later to
619  *		complete the request
620  * ENOTCONN:	Caller needs to invoke connect logic then call again
621  *    other:	Some other error occurred, the request was not sent
622  */
623 static int xs_udp_send_request(struct rpc_task *task)
624 {
625 	struct rpc_rqst *req = task->tk_rqstp;
626 	struct rpc_xprt *xprt = req->rq_xprt;
627 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
628 	struct xdr_buf *xdr = &req->rq_snd_buf;
629 	int status;
630 
631 	xs_pktdump("packet data:",
632 				req->rq_svec->iov_base,
633 				req->rq_svec->iov_len);
634 
635 	if (!xprt_bound(xprt))
636 		return -ENOTCONN;
637 	status = xs_sendpages(transport->sock,
638 			      xs_addr(xprt),
639 			      xprt->addrlen, xdr,
640 			      req->rq_bytes_sent, true);
641 
642 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
643 			xdr->len - req->rq_bytes_sent, status);
644 
645 	if (status >= 0) {
646 		req->rq_xmit_bytes_sent += status;
647 		if (status >= req->rq_slen)
648 			return 0;
649 		/* Still some bytes left; set up for a retry later. */
650 		status = -EAGAIN;
651 	}
652 
653 	switch (status) {
654 	case -ENOTSOCK:
655 		status = -ENOTCONN;
656 		/* Should we call xs_close() here? */
657 		break;
658 	case -EAGAIN:
659 		status = xs_nospace(task);
660 		break;
661 	default:
662 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
663 			-status);
664 	case -ENETUNREACH:
665 	case -ENOBUFS:
666 	case -EPIPE:
667 	case -ECONNREFUSED:
668 		/* When the server has died, an ICMP port unreachable message
669 		 * prompts ECONNREFUSED. */
670 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
671 	}
672 
673 	return status;
674 }
675 
676 /**
677  * xs_tcp_shutdown - gracefully shut down a TCP socket
678  * @xprt: transport
679  *
680  * Initiates a graceful shutdown of the TCP socket by calling the
681  * equivalent of shutdown(SHUT_WR);
682  */
683 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
684 {
685 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
686 	struct socket *sock = transport->sock;
687 
688 	if (sock != NULL) {
689 		kernel_sock_shutdown(sock, SHUT_WR);
690 		trace_rpc_socket_shutdown(xprt, sock);
691 	}
692 }
693 
694 /**
695  * xs_tcp_send_request - write an RPC request to a TCP socket
696  * @task: address of RPC task that manages the state of an RPC request
697  *
698  * Return values:
699  *        0:	The request has been sent
700  *   EAGAIN:	The socket was blocked, please call again later to
701  *		complete the request
702  * ENOTCONN:	Caller needs to invoke connect logic then call again
703  *    other:	Some other error occurred, the request was not sent
704  *
705  * XXX: In the case of soft timeouts, should we eventually give up
706  *	if sendmsg is not able to make progress?
707  */
708 static int xs_tcp_send_request(struct rpc_task *task)
709 {
710 	struct rpc_rqst *req = task->tk_rqstp;
711 	struct rpc_xprt *xprt = req->rq_xprt;
712 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
713 	struct xdr_buf *xdr = &req->rq_snd_buf;
714 	bool zerocopy = true;
715 	int status;
716 
717 	xs_encode_stream_record_marker(&req->rq_snd_buf);
718 
719 	xs_pktdump("packet data:",
720 				req->rq_svec->iov_base,
721 				req->rq_svec->iov_len);
722 	/* Don't use zero copy if this is a resend. If the RPC call
723 	 * completes while the socket holds a reference to the pages,
724 	 * then we may end up resending corrupted data.
725 	 */
726 	if (task->tk_flags & RPC_TASK_SENT)
727 		zerocopy = false;
728 
729 	/* Continue transmitting the packet/record. We must be careful
730 	 * to cope with writespace callbacks arriving _after_ we have
731 	 * called sendmsg(). */
732 	while (1) {
733 		status = xs_sendpages(transport->sock,
734 					NULL, 0, xdr, req->rq_bytes_sent,
735 					zerocopy);
736 
737 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
738 				xdr->len - req->rq_bytes_sent, status);
739 
740 		if (unlikely(status < 0))
741 			break;
742 
743 		/* If we've sent the entire packet, immediately
744 		 * reset the count of bytes sent. */
745 		req->rq_bytes_sent += status;
746 		req->rq_xmit_bytes_sent += status;
747 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
748 			req->rq_bytes_sent = 0;
749 			return 0;
750 		}
751 
752 		if (status != 0)
753 			continue;
754 		status = -EAGAIN;
755 		break;
756 	}
757 
758 	switch (status) {
759 	case -ENOTSOCK:
760 		status = -ENOTCONN;
761 		/* Should we call xs_close() here? */
762 		break;
763 	case -ENOBUFS:
764 	case -EAGAIN:
765 		status = xs_nospace(task);
766 		break;
767 	default:
768 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
769 			-status);
770 	case -ECONNRESET:
771 		xs_tcp_shutdown(xprt);
772 	case -ECONNREFUSED:
773 	case -ENOTCONN:
774 	case -EPIPE:
775 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
776 	}
777 
778 	return status;
779 }
780 
781 /**
782  * xs_tcp_release_xprt - clean up after a tcp transmission
783  * @xprt: transport
784  * @task: rpc task
785  *
786  * This cleans up if an error causes us to abort the transmission of a request.
787  * In this case, the socket may need to be reset in order to avoid confusing
788  * the server.
789  */
790 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
791 {
792 	struct rpc_rqst *req;
793 
794 	if (task != xprt->snd_task)
795 		return;
796 	if (task == NULL)
797 		goto out_release;
798 	req = task->tk_rqstp;
799 	if (req == NULL)
800 		goto out_release;
801 	if (req->rq_bytes_sent == 0)
802 		goto out_release;
803 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
804 		goto out_release;
805 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
806 out_release:
807 	xprt_release_xprt(xprt, task);
808 }
809 
810 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
811 {
812 	transport->old_data_ready = sk->sk_data_ready;
813 	transport->old_state_change = sk->sk_state_change;
814 	transport->old_write_space = sk->sk_write_space;
815 	transport->old_error_report = sk->sk_error_report;
816 }
817 
818 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
819 {
820 	sk->sk_data_ready = transport->old_data_ready;
821 	sk->sk_state_change = transport->old_state_change;
822 	sk->sk_write_space = transport->old_write_space;
823 	sk->sk_error_report = transport->old_error_report;
824 }
825 
826 /**
827  * xs_error_report - callback to handle TCP socket state errors
828  * @sk: socket
829  *
830  * Note: we don't call sock_error() since there may be a rpc_task
831  * using the socket, and so we don't want to clear sk->sk_err.
832  */
833 static void xs_error_report(struct sock *sk)
834 {
835 	struct rpc_xprt *xprt;
836 	int err;
837 
838 	read_lock_bh(&sk->sk_callback_lock);
839 	if (!(xprt = xprt_from_sock(sk)))
840 		goto out;
841 
842 	err = -sk->sk_err;
843 	if (err == 0)
844 		goto out;
845 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
846 			xprt, -err);
847 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
848 	xprt_wake_pending_tasks(xprt, err);
849  out:
850 	read_unlock_bh(&sk->sk_callback_lock);
851 }
852 
853 static void xs_reset_transport(struct sock_xprt *transport)
854 {
855 	struct socket *sock = transport->sock;
856 	struct sock *sk = transport->inet;
857 
858 	if (sk == NULL)
859 		return;
860 
861 	transport->srcport = 0;
862 
863 	write_lock_bh(&sk->sk_callback_lock);
864 	transport->inet = NULL;
865 	transport->sock = NULL;
866 
867 	sk->sk_user_data = NULL;
868 
869 	xs_restore_old_callbacks(transport, sk);
870 	write_unlock_bh(&sk->sk_callback_lock);
871 
872 	trace_rpc_socket_close(&transport->xprt, sock);
873 	sock_release(sock);
874 }
875 
876 /**
877  * xs_close - close a socket
878  * @xprt: transport
879  *
880  * This is used when all requests are complete; ie, no DRC state remains
881  * on the server we want to save.
882  *
883  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
884  * xs_reset_transport() zeroing the socket from underneath a writer.
885  */
886 static void xs_close(struct rpc_xprt *xprt)
887 {
888 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
889 
890 	dprintk("RPC:       xs_close xprt %p\n", xprt);
891 
892 	cancel_delayed_work_sync(&transport->connect_worker);
893 
894 	xs_reset_transport(transport);
895 	xprt->reestablish_timeout = 0;
896 
897 	smp_mb__before_atomic();
898 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
899 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
900 	clear_bit(XPRT_CLOSING, &xprt->state);
901 	smp_mb__after_atomic();
902 	xprt_disconnect_done(xprt);
903 }
904 
905 static void xs_tcp_close(struct rpc_xprt *xprt)
906 {
907 	if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
908 		xs_close(xprt);
909 	else
910 		xs_tcp_shutdown(xprt);
911 }
912 
913 static void xs_xprt_free(struct rpc_xprt *xprt)
914 {
915 	xs_free_peer_addresses(xprt);
916 	xprt_free(xprt);
917 }
918 
919 /**
920  * xs_destroy - prepare to shutdown a transport
921  * @xprt: doomed transport
922  *
923  */
924 static void xs_destroy(struct rpc_xprt *xprt)
925 {
926 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
927 
928 	xs_close(xprt);
929 	xs_xprt_free(xprt);
930 	module_put(THIS_MODULE);
931 }
932 
933 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
934 {
935 	struct xdr_skb_reader desc = {
936 		.skb		= skb,
937 		.offset		= sizeof(rpc_fraghdr),
938 		.count		= skb->len - sizeof(rpc_fraghdr),
939 	};
940 
941 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
942 		return -1;
943 	if (desc.count)
944 		return -1;
945 	return 0;
946 }
947 
948 /**
949  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
950  * @sk: socket with data to read
951  * @len: how much data to read
952  *
953  * Currently this assumes we can read the whole reply in a single gulp.
954  */
955 static void xs_local_data_ready(struct sock *sk)
956 {
957 	struct rpc_task *task;
958 	struct rpc_xprt *xprt;
959 	struct rpc_rqst *rovr;
960 	struct sk_buff *skb;
961 	int err, repsize, copied;
962 	u32 _xid;
963 	__be32 *xp;
964 
965 	read_lock_bh(&sk->sk_callback_lock);
966 	dprintk("RPC:       %s...\n", __func__);
967 	xprt = xprt_from_sock(sk);
968 	if (xprt == NULL)
969 		goto out;
970 
971 	skb = skb_recv_datagram(sk, 0, 1, &err);
972 	if (skb == NULL)
973 		goto out;
974 
975 	repsize = skb->len - sizeof(rpc_fraghdr);
976 	if (repsize < 4) {
977 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
978 		goto dropit;
979 	}
980 
981 	/* Copy the XID from the skb... */
982 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
983 	if (xp == NULL)
984 		goto dropit;
985 
986 	/* Look up and lock the request corresponding to the given XID */
987 	spin_lock(&xprt->transport_lock);
988 	rovr = xprt_lookup_rqst(xprt, *xp);
989 	if (!rovr)
990 		goto out_unlock;
991 	task = rovr->rq_task;
992 
993 	copied = rovr->rq_private_buf.buflen;
994 	if (copied > repsize)
995 		copied = repsize;
996 
997 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
998 		dprintk("RPC:       sk_buff copy failed\n");
999 		goto out_unlock;
1000 	}
1001 
1002 	xprt_complete_rqst(task, copied);
1003 
1004  out_unlock:
1005 	spin_unlock(&xprt->transport_lock);
1006  dropit:
1007 	skb_free_datagram(sk, skb);
1008  out:
1009 	read_unlock_bh(&sk->sk_callback_lock);
1010 }
1011 
1012 /**
1013  * xs_udp_data_ready - "data ready" callback for UDP sockets
1014  * @sk: socket with data to read
1015  * @len: how much data to read
1016  *
1017  */
1018 static void xs_udp_data_ready(struct sock *sk)
1019 {
1020 	struct rpc_task *task;
1021 	struct rpc_xprt *xprt;
1022 	struct rpc_rqst *rovr;
1023 	struct sk_buff *skb;
1024 	int err, repsize, copied;
1025 	u32 _xid;
1026 	__be32 *xp;
1027 
1028 	read_lock_bh(&sk->sk_callback_lock);
1029 	dprintk("RPC:       xs_udp_data_ready...\n");
1030 	if (!(xprt = xprt_from_sock(sk)))
1031 		goto out;
1032 
1033 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
1034 		goto out;
1035 
1036 	repsize = skb->len - sizeof(struct udphdr);
1037 	if (repsize < 4) {
1038 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1039 		goto dropit;
1040 	}
1041 
1042 	/* Copy the XID from the skb... */
1043 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
1044 				sizeof(_xid), &_xid);
1045 	if (xp == NULL)
1046 		goto dropit;
1047 
1048 	/* Look up and lock the request corresponding to the given XID */
1049 	spin_lock(&xprt->transport_lock);
1050 	rovr = xprt_lookup_rqst(xprt, *xp);
1051 	if (!rovr)
1052 		goto out_unlock;
1053 	task = rovr->rq_task;
1054 
1055 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1056 		copied = repsize;
1057 
1058 	/* Suck it into the iovec, verify checksum if not done by hw. */
1059 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1060 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1061 		goto out_unlock;
1062 	}
1063 
1064 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1065 
1066 	xprt_adjust_cwnd(xprt, task, copied);
1067 	xprt_complete_rqst(task, copied);
1068 
1069  out_unlock:
1070 	spin_unlock(&xprt->transport_lock);
1071  dropit:
1072 	skb_free_datagram(sk, skb);
1073  out:
1074 	read_unlock_bh(&sk->sk_callback_lock);
1075 }
1076 
1077 /*
1078  * Helper function to force a TCP close if the server is sending
1079  * junk and/or it has put us in CLOSE_WAIT
1080  */
1081 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1082 {
1083 	set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1084 	xprt_force_disconnect(xprt);
1085 }
1086 
1087 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1088 {
1089 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1090 	size_t len, used;
1091 	char *p;
1092 
1093 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1094 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1095 	used = xdr_skb_read_bits(desc, p, len);
1096 	transport->tcp_offset += used;
1097 	if (used != len)
1098 		return;
1099 
1100 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1101 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1102 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1103 	else
1104 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1105 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1106 
1107 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1108 	transport->tcp_offset = 0;
1109 
1110 	/* Sanity check of the record length */
1111 	if (unlikely(transport->tcp_reclen < 8)) {
1112 		dprintk("RPC:       invalid TCP record fragment length\n");
1113 		xs_tcp_force_close(xprt);
1114 		return;
1115 	}
1116 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1117 			transport->tcp_reclen);
1118 }
1119 
1120 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1121 {
1122 	if (transport->tcp_offset == transport->tcp_reclen) {
1123 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1124 		transport->tcp_offset = 0;
1125 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1126 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1127 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1128 			transport->tcp_copied = 0;
1129 		}
1130 	}
1131 }
1132 
1133 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1134 {
1135 	size_t len, used;
1136 	char *p;
1137 
1138 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1139 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1140 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1141 	used = xdr_skb_read_bits(desc, p, len);
1142 	transport->tcp_offset += used;
1143 	if (used != len)
1144 		return;
1145 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1146 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1147 	transport->tcp_copied = 4;
1148 	dprintk("RPC:       reading %s XID %08x\n",
1149 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1150 							      : "request with",
1151 			ntohl(transport->tcp_xid));
1152 	xs_tcp_check_fraghdr(transport);
1153 }
1154 
1155 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1156 				       struct xdr_skb_reader *desc)
1157 {
1158 	size_t len, used;
1159 	u32 offset;
1160 	char *p;
1161 
1162 	/*
1163 	 * We want transport->tcp_offset to be 8 at the end of this routine
1164 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1165 	 * When this function is called for the first time,
1166 	 * transport->tcp_offset is 4 (after having already read the xid).
1167 	 */
1168 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1169 	len = sizeof(transport->tcp_calldir) - offset;
1170 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1171 	p = ((char *) &transport->tcp_calldir) + offset;
1172 	used = xdr_skb_read_bits(desc, p, len);
1173 	transport->tcp_offset += used;
1174 	if (used != len)
1175 		return;
1176 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1177 	/*
1178 	 * We don't yet have the XDR buffer, so we will write the calldir
1179 	 * out after we get the buffer from the 'struct rpc_rqst'
1180 	 */
1181 	switch (ntohl(transport->tcp_calldir)) {
1182 	case RPC_REPLY:
1183 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1184 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1185 		transport->tcp_flags |= TCP_RPC_REPLY;
1186 		break;
1187 	case RPC_CALL:
1188 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1189 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1190 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1191 		break;
1192 	default:
1193 		dprintk("RPC:       invalid request message type\n");
1194 		xs_tcp_force_close(&transport->xprt);
1195 	}
1196 	xs_tcp_check_fraghdr(transport);
1197 }
1198 
1199 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1200 				     struct xdr_skb_reader *desc,
1201 				     struct rpc_rqst *req)
1202 {
1203 	struct sock_xprt *transport =
1204 				container_of(xprt, struct sock_xprt, xprt);
1205 	struct xdr_buf *rcvbuf;
1206 	size_t len;
1207 	ssize_t r;
1208 
1209 	rcvbuf = &req->rq_private_buf;
1210 
1211 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1212 		/*
1213 		 * Save the RPC direction in the XDR buffer
1214 		 */
1215 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1216 			&transport->tcp_calldir,
1217 			sizeof(transport->tcp_calldir));
1218 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1219 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1220 	}
1221 
1222 	len = desc->count;
1223 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1224 		struct xdr_skb_reader my_desc;
1225 
1226 		len = transport->tcp_reclen - transport->tcp_offset;
1227 		memcpy(&my_desc, desc, sizeof(my_desc));
1228 		my_desc.count = len;
1229 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1230 					  &my_desc, xdr_skb_read_bits);
1231 		desc->count -= r;
1232 		desc->offset += r;
1233 	} else
1234 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1235 					  desc, xdr_skb_read_bits);
1236 
1237 	if (r > 0) {
1238 		transport->tcp_copied += r;
1239 		transport->tcp_offset += r;
1240 	}
1241 	if (r != len) {
1242 		/* Error when copying to the receive buffer,
1243 		 * usually because we weren't able to allocate
1244 		 * additional buffer pages. All we can do now
1245 		 * is turn off TCP_RCV_COPY_DATA, so the request
1246 		 * will not receive any additional updates,
1247 		 * and time out.
1248 		 * Any remaining data from this record will
1249 		 * be discarded.
1250 		 */
1251 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1252 		dprintk("RPC:       XID %08x truncated request\n",
1253 				ntohl(transport->tcp_xid));
1254 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1255 				"tcp_offset = %u, tcp_reclen = %u\n",
1256 				xprt, transport->tcp_copied,
1257 				transport->tcp_offset, transport->tcp_reclen);
1258 		return;
1259 	}
1260 
1261 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1262 			ntohl(transport->tcp_xid), r);
1263 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1264 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1265 			transport->tcp_offset, transport->tcp_reclen);
1266 
1267 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1268 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1269 	else if (transport->tcp_offset == transport->tcp_reclen) {
1270 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1271 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1272 	}
1273 }
1274 
1275 /*
1276  * Finds the request corresponding to the RPC xid and invokes the common
1277  * tcp read code to read the data.
1278  */
1279 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1280 				    struct xdr_skb_reader *desc)
1281 {
1282 	struct sock_xprt *transport =
1283 				container_of(xprt, struct sock_xprt, xprt);
1284 	struct rpc_rqst *req;
1285 
1286 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1287 
1288 	/* Find and lock the request corresponding to this xid */
1289 	spin_lock(&xprt->transport_lock);
1290 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1291 	if (!req) {
1292 		dprintk("RPC:       XID %08x request not found!\n",
1293 				ntohl(transport->tcp_xid));
1294 		spin_unlock(&xprt->transport_lock);
1295 		return -1;
1296 	}
1297 
1298 	xs_tcp_read_common(xprt, desc, req);
1299 
1300 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1301 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1302 
1303 	spin_unlock(&xprt->transport_lock);
1304 	return 0;
1305 }
1306 
1307 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1308 /*
1309  * Obtains an rpc_rqst previously allocated and invokes the common
1310  * tcp read code to read the data.  The result is placed in the callback
1311  * queue.
1312  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1313  * connection and return -1.
1314  */
1315 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1316 				       struct xdr_skb_reader *desc)
1317 {
1318 	struct sock_xprt *transport =
1319 				container_of(xprt, struct sock_xprt, xprt);
1320 	struct rpc_rqst *req;
1321 
1322 	/* Look up and lock the request corresponding to the given XID */
1323 	spin_lock(&xprt->transport_lock);
1324 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1325 	if (req == NULL) {
1326 		spin_unlock(&xprt->transport_lock);
1327 		printk(KERN_WARNING "Callback slot table overflowed\n");
1328 		xprt_force_disconnect(xprt);
1329 		return -1;
1330 	}
1331 
1332 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1333 	xs_tcp_read_common(xprt, desc, req);
1334 
1335 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1336 		xprt_complete_bc_request(req, transport->tcp_copied);
1337 	spin_unlock(&xprt->transport_lock);
1338 
1339 	return 0;
1340 }
1341 
1342 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1343 					struct xdr_skb_reader *desc)
1344 {
1345 	struct sock_xprt *transport =
1346 				container_of(xprt, struct sock_xprt, xprt);
1347 
1348 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1349 		xs_tcp_read_reply(xprt, desc) :
1350 		xs_tcp_read_callback(xprt, desc);
1351 }
1352 #else
1353 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1354 					struct xdr_skb_reader *desc)
1355 {
1356 	return xs_tcp_read_reply(xprt, desc);
1357 }
1358 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1359 
1360 /*
1361  * Read data off the transport.  This can be either an RPC_CALL or an
1362  * RPC_REPLY.  Relay the processing to helper functions.
1363  */
1364 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1365 				    struct xdr_skb_reader *desc)
1366 {
1367 	struct sock_xprt *transport =
1368 				container_of(xprt, struct sock_xprt, xprt);
1369 
1370 	if (_xs_tcp_read_data(xprt, desc) == 0)
1371 		xs_tcp_check_fraghdr(transport);
1372 	else {
1373 		/*
1374 		 * The transport_lock protects the request handling.
1375 		 * There's no need to hold it to update the tcp_flags.
1376 		 */
1377 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1378 	}
1379 }
1380 
1381 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1382 {
1383 	size_t len;
1384 
1385 	len = transport->tcp_reclen - transport->tcp_offset;
1386 	if (len > desc->count)
1387 		len = desc->count;
1388 	desc->count -= len;
1389 	desc->offset += len;
1390 	transport->tcp_offset += len;
1391 	dprintk("RPC:       discarded %Zu bytes\n", len);
1392 	xs_tcp_check_fraghdr(transport);
1393 }
1394 
1395 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1396 {
1397 	struct rpc_xprt *xprt = rd_desc->arg.data;
1398 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1399 	struct xdr_skb_reader desc = {
1400 		.skb	= skb,
1401 		.offset	= offset,
1402 		.count	= len,
1403 	};
1404 
1405 	dprintk("RPC:       xs_tcp_data_recv started\n");
1406 	do {
1407 		/* Read in a new fragment marker if necessary */
1408 		/* Can we ever really expect to get completely empty fragments? */
1409 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1410 			xs_tcp_read_fraghdr(xprt, &desc);
1411 			continue;
1412 		}
1413 		/* Read in the xid if necessary */
1414 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1415 			xs_tcp_read_xid(transport, &desc);
1416 			continue;
1417 		}
1418 		/* Read in the call/reply flag */
1419 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1420 			xs_tcp_read_calldir(transport, &desc);
1421 			continue;
1422 		}
1423 		/* Read in the request data */
1424 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1425 			xs_tcp_read_data(xprt, &desc);
1426 			continue;
1427 		}
1428 		/* Skip over any trailing bytes on short reads */
1429 		xs_tcp_read_discard(transport, &desc);
1430 	} while (desc.count);
1431 	dprintk("RPC:       xs_tcp_data_recv done\n");
1432 	return len - desc.count;
1433 }
1434 
1435 /**
1436  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1437  * @sk: socket with data to read
1438  * @bytes: how much data to read
1439  *
1440  */
1441 static void xs_tcp_data_ready(struct sock *sk)
1442 {
1443 	struct rpc_xprt *xprt;
1444 	read_descriptor_t rd_desc;
1445 	int read;
1446 
1447 	dprintk("RPC:       xs_tcp_data_ready...\n");
1448 
1449 	read_lock_bh(&sk->sk_callback_lock);
1450 	if (!(xprt = xprt_from_sock(sk)))
1451 		goto out;
1452 	/* Any data means we had a useful conversation, so
1453 	 * the we don't need to delay the next reconnect
1454 	 */
1455 	if (xprt->reestablish_timeout)
1456 		xprt->reestablish_timeout = 0;
1457 
1458 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1459 	rd_desc.arg.data = xprt;
1460 	do {
1461 		rd_desc.count = 65536;
1462 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1463 	} while (read > 0);
1464 out:
1465 	read_unlock_bh(&sk->sk_callback_lock);
1466 }
1467 
1468 /*
1469  * Do the equivalent of linger/linger2 handling for dealing with
1470  * broken servers that don't close the socket in a timely
1471  * fashion
1472  */
1473 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1474 		unsigned long timeout)
1475 {
1476 	struct sock_xprt *transport;
1477 
1478 	if (xprt_test_and_set_connecting(xprt))
1479 		return;
1480 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1481 	transport = container_of(xprt, struct sock_xprt, xprt);
1482 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1483 			   timeout);
1484 }
1485 
1486 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1487 {
1488 	struct sock_xprt *transport;
1489 
1490 	transport = container_of(xprt, struct sock_xprt, xprt);
1491 
1492 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1493 	    !cancel_delayed_work(&transport->connect_worker))
1494 		return;
1495 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1496 	xprt_clear_connecting(xprt);
1497 }
1498 
1499 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1500 {
1501 	smp_mb__before_atomic();
1502 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1503 	clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1504 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1505 	clear_bit(XPRT_CLOSING, &xprt->state);
1506 	smp_mb__after_atomic();
1507 }
1508 
1509 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1510 {
1511 	xs_sock_reset_connection_flags(xprt);
1512 	/* Mark transport as closed and wake up all pending tasks */
1513 	xprt_disconnect_done(xprt);
1514 }
1515 
1516 /**
1517  * xs_tcp_state_change - callback to handle TCP socket state changes
1518  * @sk: socket whose state has changed
1519  *
1520  */
1521 static void xs_tcp_state_change(struct sock *sk)
1522 {
1523 	struct rpc_xprt *xprt;
1524 
1525 	read_lock_bh(&sk->sk_callback_lock);
1526 	if (!(xprt = xprt_from_sock(sk)))
1527 		goto out;
1528 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1529 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1530 			sk->sk_state, xprt_connected(xprt),
1531 			sock_flag(sk, SOCK_DEAD),
1532 			sock_flag(sk, SOCK_ZAPPED),
1533 			sk->sk_shutdown);
1534 
1535 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1536 	switch (sk->sk_state) {
1537 	case TCP_ESTABLISHED:
1538 		spin_lock(&xprt->transport_lock);
1539 		if (!xprt_test_and_set_connected(xprt)) {
1540 			struct sock_xprt *transport = container_of(xprt,
1541 					struct sock_xprt, xprt);
1542 
1543 			/* Reset TCP record info */
1544 			transport->tcp_offset = 0;
1545 			transport->tcp_reclen = 0;
1546 			transport->tcp_copied = 0;
1547 			transport->tcp_flags =
1548 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1549 			xprt->connect_cookie++;
1550 
1551 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1552 		}
1553 		spin_unlock(&xprt->transport_lock);
1554 		break;
1555 	case TCP_FIN_WAIT1:
1556 		/* The client initiated a shutdown of the socket */
1557 		xprt->connect_cookie++;
1558 		xprt->reestablish_timeout = 0;
1559 		set_bit(XPRT_CLOSING, &xprt->state);
1560 		smp_mb__before_atomic();
1561 		clear_bit(XPRT_CONNECTED, &xprt->state);
1562 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1563 		smp_mb__after_atomic();
1564 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1565 		break;
1566 	case TCP_CLOSE_WAIT:
1567 		/* The server initiated a shutdown of the socket */
1568 		xprt->connect_cookie++;
1569 		clear_bit(XPRT_CONNECTED, &xprt->state);
1570 		xs_tcp_force_close(xprt);
1571 	case TCP_CLOSING:
1572 		/*
1573 		 * If the server closed down the connection, make sure that
1574 		 * we back off before reconnecting
1575 		 */
1576 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1577 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1578 		break;
1579 	case TCP_LAST_ACK:
1580 		set_bit(XPRT_CLOSING, &xprt->state);
1581 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1582 		smp_mb__before_atomic();
1583 		clear_bit(XPRT_CONNECTED, &xprt->state);
1584 		smp_mb__after_atomic();
1585 		break;
1586 	case TCP_CLOSE:
1587 		xs_tcp_cancel_linger_timeout(xprt);
1588 		xs_sock_mark_closed(xprt);
1589 	}
1590  out:
1591 	read_unlock_bh(&sk->sk_callback_lock);
1592 }
1593 
1594 static void xs_write_space(struct sock *sk)
1595 {
1596 	struct socket *sock;
1597 	struct rpc_xprt *xprt;
1598 
1599 	if (unlikely(!(sock = sk->sk_socket)))
1600 		return;
1601 	clear_bit(SOCK_NOSPACE, &sock->flags);
1602 
1603 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1604 		return;
1605 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1606 		return;
1607 
1608 	xprt_write_space(xprt);
1609 }
1610 
1611 /**
1612  * xs_udp_write_space - callback invoked when socket buffer space
1613  *                             becomes available
1614  * @sk: socket whose state has changed
1615  *
1616  * Called when more output buffer space is available for this socket.
1617  * We try not to wake our writers until they can make "significant"
1618  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1619  * with a bunch of small requests.
1620  */
1621 static void xs_udp_write_space(struct sock *sk)
1622 {
1623 	read_lock_bh(&sk->sk_callback_lock);
1624 
1625 	/* from net/core/sock.c:sock_def_write_space */
1626 	if (sock_writeable(sk))
1627 		xs_write_space(sk);
1628 
1629 	read_unlock_bh(&sk->sk_callback_lock);
1630 }
1631 
1632 /**
1633  * xs_tcp_write_space - callback invoked when socket buffer space
1634  *                             becomes available
1635  * @sk: socket whose state has changed
1636  *
1637  * Called when more output buffer space is available for this socket.
1638  * We try not to wake our writers until they can make "significant"
1639  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1640  * with a bunch of small requests.
1641  */
1642 static void xs_tcp_write_space(struct sock *sk)
1643 {
1644 	read_lock_bh(&sk->sk_callback_lock);
1645 
1646 	/* from net/core/stream.c:sk_stream_write_space */
1647 	if (sk_stream_is_writeable(sk))
1648 		xs_write_space(sk);
1649 
1650 	read_unlock_bh(&sk->sk_callback_lock);
1651 }
1652 
1653 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1654 {
1655 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1656 	struct sock *sk = transport->inet;
1657 
1658 	if (transport->rcvsize) {
1659 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1660 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1661 	}
1662 	if (transport->sndsize) {
1663 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1664 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1665 		sk->sk_write_space(sk);
1666 	}
1667 }
1668 
1669 /**
1670  * xs_udp_set_buffer_size - set send and receive limits
1671  * @xprt: generic transport
1672  * @sndsize: requested size of send buffer, in bytes
1673  * @rcvsize: requested size of receive buffer, in bytes
1674  *
1675  * Set socket send and receive buffer size limits.
1676  */
1677 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1678 {
1679 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1680 
1681 	transport->sndsize = 0;
1682 	if (sndsize)
1683 		transport->sndsize = sndsize + 1024;
1684 	transport->rcvsize = 0;
1685 	if (rcvsize)
1686 		transport->rcvsize = rcvsize + 1024;
1687 
1688 	xs_udp_do_set_buffer_size(xprt);
1689 }
1690 
1691 /**
1692  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1693  * @task: task that timed out
1694  *
1695  * Adjust the congestion window after a retransmit timeout has occurred.
1696  */
1697 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1698 {
1699 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1700 }
1701 
1702 static unsigned short xs_get_random_port(void)
1703 {
1704 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1705 	unsigned short rand = (unsigned short) prandom_u32() % range;
1706 	return rand + xprt_min_resvport;
1707 }
1708 
1709 /**
1710  * xs_set_port - reset the port number in the remote endpoint address
1711  * @xprt: generic transport
1712  * @port: new port number
1713  *
1714  */
1715 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1716 {
1717 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1718 
1719 	rpc_set_port(xs_addr(xprt), port);
1720 	xs_update_peer_port(xprt);
1721 }
1722 
1723 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1724 {
1725 	unsigned short port = transport->srcport;
1726 
1727 	if (port == 0 && transport->xprt.resvport)
1728 		port = xs_get_random_port();
1729 	return port;
1730 }
1731 
1732 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1733 {
1734 	if (transport->srcport != 0)
1735 		transport->srcport = 0;
1736 	if (!transport->xprt.resvport)
1737 		return 0;
1738 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1739 		return xprt_max_resvport;
1740 	return --port;
1741 }
1742 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1743 {
1744 	struct sockaddr_storage myaddr;
1745 	int err, nloop = 0;
1746 	unsigned short port = xs_get_srcport(transport);
1747 	unsigned short last;
1748 
1749 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1750 	do {
1751 		rpc_set_port((struct sockaddr *)&myaddr, port);
1752 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1753 				transport->xprt.addrlen);
1754 		if (port == 0)
1755 			break;
1756 		if (err == 0) {
1757 			transport->srcport = port;
1758 			break;
1759 		}
1760 		last = port;
1761 		port = xs_next_srcport(transport, port);
1762 		if (port > last)
1763 			nloop++;
1764 	} while (err == -EADDRINUSE && nloop != 2);
1765 
1766 	if (myaddr.ss_family == AF_INET)
1767 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1768 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1769 				port, err ? "failed" : "ok", err);
1770 	else
1771 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1772 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1773 				port, err ? "failed" : "ok", err);
1774 	return err;
1775 }
1776 
1777 /*
1778  * We don't support autobind on AF_LOCAL sockets
1779  */
1780 static void xs_local_rpcbind(struct rpc_task *task)
1781 {
1782 	rcu_read_lock();
1783 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1784 	rcu_read_unlock();
1785 }
1786 
1787 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1788 {
1789 }
1790 
1791 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1792 static struct lock_class_key xs_key[2];
1793 static struct lock_class_key xs_slock_key[2];
1794 
1795 static inline void xs_reclassify_socketu(struct socket *sock)
1796 {
1797 	struct sock *sk = sock->sk;
1798 
1799 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1800 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1801 }
1802 
1803 static inline void xs_reclassify_socket4(struct socket *sock)
1804 {
1805 	struct sock *sk = sock->sk;
1806 
1807 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1808 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1809 }
1810 
1811 static inline void xs_reclassify_socket6(struct socket *sock)
1812 {
1813 	struct sock *sk = sock->sk;
1814 
1815 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1816 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1817 }
1818 
1819 static inline void xs_reclassify_socket(int family, struct socket *sock)
1820 {
1821 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1822 	if (sock_owned_by_user(sock->sk))
1823 		return;
1824 
1825 	switch (family) {
1826 	case AF_LOCAL:
1827 		xs_reclassify_socketu(sock);
1828 		break;
1829 	case AF_INET:
1830 		xs_reclassify_socket4(sock);
1831 		break;
1832 	case AF_INET6:
1833 		xs_reclassify_socket6(sock);
1834 		break;
1835 	}
1836 }
1837 #else
1838 static inline void xs_reclassify_socketu(struct socket *sock)
1839 {
1840 }
1841 
1842 static inline void xs_reclassify_socket4(struct socket *sock)
1843 {
1844 }
1845 
1846 static inline void xs_reclassify_socket6(struct socket *sock)
1847 {
1848 }
1849 
1850 static inline void xs_reclassify_socket(int family, struct socket *sock)
1851 {
1852 }
1853 #endif
1854 
1855 static void xs_dummy_setup_socket(struct work_struct *work)
1856 {
1857 }
1858 
1859 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1860 		struct sock_xprt *transport, int family, int type, int protocol)
1861 {
1862 	struct socket *sock;
1863 	int err;
1864 
1865 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1866 	if (err < 0) {
1867 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1868 				protocol, -err);
1869 		goto out;
1870 	}
1871 	xs_reclassify_socket(family, sock);
1872 
1873 	err = xs_bind(transport, sock);
1874 	if (err) {
1875 		sock_release(sock);
1876 		goto out;
1877 	}
1878 
1879 	return sock;
1880 out:
1881 	return ERR_PTR(err);
1882 }
1883 
1884 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1885 				      struct socket *sock)
1886 {
1887 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1888 									xprt);
1889 
1890 	if (!transport->inet) {
1891 		struct sock *sk = sock->sk;
1892 
1893 		write_lock_bh(&sk->sk_callback_lock);
1894 
1895 		xs_save_old_callbacks(transport, sk);
1896 
1897 		sk->sk_user_data = xprt;
1898 		sk->sk_data_ready = xs_local_data_ready;
1899 		sk->sk_write_space = xs_udp_write_space;
1900 		sk->sk_error_report = xs_error_report;
1901 		sk->sk_allocation = GFP_ATOMIC;
1902 
1903 		xprt_clear_connected(xprt);
1904 
1905 		/* Reset to new socket */
1906 		transport->sock = sock;
1907 		transport->inet = sk;
1908 
1909 		write_unlock_bh(&sk->sk_callback_lock);
1910 	}
1911 
1912 	/* Tell the socket layer to start connecting... */
1913 	xprt->stat.connect_count++;
1914 	xprt->stat.connect_start = jiffies;
1915 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1916 }
1917 
1918 /**
1919  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1920  * @xprt: RPC transport to connect
1921  * @transport: socket transport to connect
1922  * @create_sock: function to create a socket of the correct type
1923  */
1924 static int xs_local_setup_socket(struct sock_xprt *transport)
1925 {
1926 	struct rpc_xprt *xprt = &transport->xprt;
1927 	struct socket *sock;
1928 	int status = -EIO;
1929 
1930 	current->flags |= PF_FSTRANS;
1931 
1932 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1933 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1934 					SOCK_STREAM, 0, &sock, 1);
1935 	if (status < 0) {
1936 		dprintk("RPC:       can't create AF_LOCAL "
1937 			"transport socket (%d).\n", -status);
1938 		goto out;
1939 	}
1940 	xs_reclassify_socketu(sock);
1941 
1942 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1943 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1944 
1945 	status = xs_local_finish_connecting(xprt, sock);
1946 	trace_rpc_socket_connect(xprt, sock, status);
1947 	switch (status) {
1948 	case 0:
1949 		dprintk("RPC:       xprt %p connected to %s\n",
1950 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1951 		xprt_set_connected(xprt);
1952 	case -ENOBUFS:
1953 		break;
1954 	case -ENOENT:
1955 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1956 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1957 		break;
1958 	case -ECONNREFUSED:
1959 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1960 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1961 		break;
1962 	default:
1963 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1964 				__func__, -status,
1965 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1966 	}
1967 
1968 out:
1969 	xprt_clear_connecting(xprt);
1970 	xprt_wake_pending_tasks(xprt, status);
1971 	current->flags &= ~PF_FSTRANS;
1972 	return status;
1973 }
1974 
1975 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1976 {
1977 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1978 	int ret;
1979 
1980 	 if (RPC_IS_ASYNC(task)) {
1981 		/*
1982 		 * We want the AF_LOCAL connect to be resolved in the
1983 		 * filesystem namespace of the process making the rpc
1984 		 * call.  Thus we connect synchronously.
1985 		 *
1986 		 * If we want to support asynchronous AF_LOCAL calls,
1987 		 * we'll need to figure out how to pass a namespace to
1988 		 * connect.
1989 		 */
1990 		rpc_exit(task, -ENOTCONN);
1991 		return;
1992 	}
1993 	ret = xs_local_setup_socket(transport);
1994 	if (ret && !RPC_IS_SOFTCONN(task))
1995 		msleep_interruptible(15000);
1996 }
1997 
1998 #ifdef CONFIG_SUNRPC_SWAP
1999 static void xs_set_memalloc(struct rpc_xprt *xprt)
2000 {
2001 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2002 			xprt);
2003 
2004 	if (xprt->swapper)
2005 		sk_set_memalloc(transport->inet);
2006 }
2007 
2008 /**
2009  * xs_swapper - Tag this transport as being used for swap.
2010  * @xprt: transport to tag
2011  * @enable: enable/disable
2012  *
2013  */
2014 int xs_swapper(struct rpc_xprt *xprt, int enable)
2015 {
2016 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2017 			xprt);
2018 	int err = 0;
2019 
2020 	if (enable) {
2021 		xprt->swapper++;
2022 		xs_set_memalloc(xprt);
2023 	} else if (xprt->swapper) {
2024 		xprt->swapper--;
2025 		sk_clear_memalloc(transport->inet);
2026 	}
2027 
2028 	return err;
2029 }
2030 EXPORT_SYMBOL_GPL(xs_swapper);
2031 #else
2032 static void xs_set_memalloc(struct rpc_xprt *xprt)
2033 {
2034 }
2035 #endif
2036 
2037 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2038 {
2039 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2040 
2041 	if (!transport->inet) {
2042 		struct sock *sk = sock->sk;
2043 
2044 		write_lock_bh(&sk->sk_callback_lock);
2045 
2046 		xs_save_old_callbacks(transport, sk);
2047 
2048 		sk->sk_user_data = xprt;
2049 		sk->sk_data_ready = xs_udp_data_ready;
2050 		sk->sk_write_space = xs_udp_write_space;
2051 		sk->sk_allocation = GFP_ATOMIC;
2052 
2053 		xprt_set_connected(xprt);
2054 
2055 		/* Reset to new socket */
2056 		transport->sock = sock;
2057 		transport->inet = sk;
2058 
2059 		xs_set_memalloc(xprt);
2060 
2061 		write_unlock_bh(&sk->sk_callback_lock);
2062 	}
2063 	xs_udp_do_set_buffer_size(xprt);
2064 }
2065 
2066 static void xs_udp_setup_socket(struct work_struct *work)
2067 {
2068 	struct sock_xprt *transport =
2069 		container_of(work, struct sock_xprt, connect_worker.work);
2070 	struct rpc_xprt *xprt = &transport->xprt;
2071 	struct socket *sock = transport->sock;
2072 	int status = -EIO;
2073 
2074 	current->flags |= PF_FSTRANS;
2075 
2076 	/* Start by resetting any existing state */
2077 	xs_reset_transport(transport);
2078 	sock = xs_create_sock(xprt, transport,
2079 			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2080 	if (IS_ERR(sock))
2081 		goto out;
2082 
2083 	dprintk("RPC:       worker connecting xprt %p via %s to "
2084 				"%s (port %s)\n", xprt,
2085 			xprt->address_strings[RPC_DISPLAY_PROTO],
2086 			xprt->address_strings[RPC_DISPLAY_ADDR],
2087 			xprt->address_strings[RPC_DISPLAY_PORT]);
2088 
2089 	xs_udp_finish_connecting(xprt, sock);
2090 	trace_rpc_socket_connect(xprt, sock, 0);
2091 	status = 0;
2092 out:
2093 	xprt_clear_connecting(xprt);
2094 	xprt_wake_pending_tasks(xprt, status);
2095 	current->flags &= ~PF_FSTRANS;
2096 }
2097 
2098 /*
2099  * We need to preserve the port number so the reply cache on the server can
2100  * find our cached RPC replies when we get around to reconnecting.
2101  */
2102 static void xs_abort_connection(struct sock_xprt *transport)
2103 {
2104 	int result;
2105 	struct sockaddr any;
2106 
2107 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2108 
2109 	/*
2110 	 * Disconnect the transport socket by doing a connect operation
2111 	 * with AF_UNSPEC.  This should return immediately...
2112 	 */
2113 	memset(&any, 0, sizeof(any));
2114 	any.sa_family = AF_UNSPEC;
2115 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2116 	trace_rpc_socket_reset_connection(&transport->xprt,
2117 			transport->sock, result);
2118 	if (!result)
2119 		xs_sock_reset_connection_flags(&transport->xprt);
2120 	dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2121 }
2122 
2123 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2124 {
2125 	unsigned int state = transport->inet->sk_state;
2126 
2127 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2128 		/* we don't need to abort the connection if the socket
2129 		 * hasn't undergone a shutdown
2130 		 */
2131 		if (transport->inet->sk_shutdown == 0)
2132 			return;
2133 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2134 				__func__, transport->inet->sk_shutdown);
2135 	}
2136 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2137 		/* we don't need to abort the connection if the socket
2138 		 * hasn't undergone a shutdown
2139 		 */
2140 		if (transport->inet->sk_shutdown == 0)
2141 			return;
2142 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2143 				"sk_shutdown set to %d\n",
2144 				__func__, transport->inet->sk_shutdown);
2145 	}
2146 	xs_abort_connection(transport);
2147 }
2148 
2149 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2150 {
2151 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2152 	int ret = -ENOTCONN;
2153 
2154 	if (!transport->inet) {
2155 		struct sock *sk = sock->sk;
2156 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2157 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2158 		unsigned int opt_on = 1;
2159 
2160 		/* TCP Keepalive options */
2161 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2162 				(char *)&opt_on, sizeof(opt_on));
2163 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2164 				(char *)&keepidle, sizeof(keepidle));
2165 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2166 				(char *)&keepidle, sizeof(keepidle));
2167 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2168 				(char *)&keepcnt, sizeof(keepcnt));
2169 
2170 		write_lock_bh(&sk->sk_callback_lock);
2171 
2172 		xs_save_old_callbacks(transport, sk);
2173 
2174 		sk->sk_user_data = xprt;
2175 		sk->sk_data_ready = xs_tcp_data_ready;
2176 		sk->sk_state_change = xs_tcp_state_change;
2177 		sk->sk_write_space = xs_tcp_write_space;
2178 		sk->sk_error_report = xs_error_report;
2179 		sk->sk_allocation = GFP_ATOMIC;
2180 
2181 		/* socket options */
2182 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2183 		sock_reset_flag(sk, SOCK_LINGER);
2184 		tcp_sk(sk)->linger2 = 0;
2185 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2186 
2187 		xprt_clear_connected(xprt);
2188 
2189 		/* Reset to new socket */
2190 		transport->sock = sock;
2191 		transport->inet = sk;
2192 
2193 		write_unlock_bh(&sk->sk_callback_lock);
2194 	}
2195 
2196 	if (!xprt_bound(xprt))
2197 		goto out;
2198 
2199 	xs_set_memalloc(xprt);
2200 
2201 	/* Tell the socket layer to start connecting... */
2202 	xprt->stat.connect_count++;
2203 	xprt->stat.connect_start = jiffies;
2204 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2205 	switch (ret) {
2206 	case 0:
2207 	case -EINPROGRESS:
2208 		/* SYN_SENT! */
2209 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2210 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2211 	}
2212 out:
2213 	return ret;
2214 }
2215 
2216 /**
2217  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2218  * @xprt: RPC transport to connect
2219  * @transport: socket transport to connect
2220  * @create_sock: function to create a socket of the correct type
2221  *
2222  * Invoked by a work queue tasklet.
2223  */
2224 static void xs_tcp_setup_socket(struct work_struct *work)
2225 {
2226 	struct sock_xprt *transport =
2227 		container_of(work, struct sock_xprt, connect_worker.work);
2228 	struct socket *sock = transport->sock;
2229 	struct rpc_xprt *xprt = &transport->xprt;
2230 	int status = -EIO;
2231 
2232 	current->flags |= PF_FSTRANS;
2233 
2234 	if (!sock) {
2235 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2236 		sock = xs_create_sock(xprt, transport,
2237 				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2238 		if (IS_ERR(sock)) {
2239 			status = PTR_ERR(sock);
2240 			goto out;
2241 		}
2242 	} else {
2243 		int abort_and_exit;
2244 
2245 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2246 				&xprt->state);
2247 		/* "close" the socket, preserving the local port */
2248 		xs_tcp_reuse_connection(transport);
2249 
2250 		if (abort_and_exit)
2251 			goto out_eagain;
2252 	}
2253 
2254 	dprintk("RPC:       worker connecting xprt %p via %s to "
2255 				"%s (port %s)\n", xprt,
2256 			xprt->address_strings[RPC_DISPLAY_PROTO],
2257 			xprt->address_strings[RPC_DISPLAY_ADDR],
2258 			xprt->address_strings[RPC_DISPLAY_PORT]);
2259 
2260 	status = xs_tcp_finish_connecting(xprt, sock);
2261 	trace_rpc_socket_connect(xprt, sock, status);
2262 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2263 			xprt, -status, xprt_connected(xprt),
2264 			sock->sk->sk_state);
2265 	switch (status) {
2266 	default:
2267 		printk("%s: connect returned unhandled error %d\n",
2268 			__func__, status);
2269 	case -EADDRNOTAVAIL:
2270 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2271 		 * and retry
2272 		 */
2273 		xs_tcp_force_close(xprt);
2274 		break;
2275 	case 0:
2276 	case -EINPROGRESS:
2277 	case -EALREADY:
2278 		xprt_clear_connecting(xprt);
2279 		current->flags &= ~PF_FSTRANS;
2280 		return;
2281 	case -EINVAL:
2282 		/* Happens, for instance, if the user specified a link
2283 		 * local IPv6 address without a scope-id.
2284 		 */
2285 	case -ECONNREFUSED:
2286 	case -ECONNRESET:
2287 	case -ENETUNREACH:
2288 	case -ENOBUFS:
2289 		/* retry with existing socket, after a delay */
2290 		goto out;
2291 	}
2292 out_eagain:
2293 	status = -EAGAIN;
2294 out:
2295 	xprt_clear_connecting(xprt);
2296 	xprt_wake_pending_tasks(xprt, status);
2297 	current->flags &= ~PF_FSTRANS;
2298 }
2299 
2300 /**
2301  * xs_connect - connect a socket to a remote endpoint
2302  * @xprt: pointer to transport structure
2303  * @task: address of RPC task that manages state of connect request
2304  *
2305  * TCP: If the remote end dropped the connection, delay reconnecting.
2306  *
2307  * UDP socket connects are synchronous, but we use a work queue anyway
2308  * to guarantee that even unprivileged user processes can set up a
2309  * socket on a privileged port.
2310  *
2311  * If a UDP socket connect fails, the delay behavior here prevents
2312  * retry floods (hard mounts).
2313  */
2314 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2315 {
2316 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2317 
2318 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2319 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2320 				"seconds\n",
2321 				xprt, xprt->reestablish_timeout / HZ);
2322 		queue_delayed_work(rpciod_workqueue,
2323 				   &transport->connect_worker,
2324 				   xprt->reestablish_timeout);
2325 		xprt->reestablish_timeout <<= 1;
2326 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2327 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2328 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2329 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2330 	} else {
2331 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2332 		queue_delayed_work(rpciod_workqueue,
2333 				   &transport->connect_worker, 0);
2334 	}
2335 }
2336 
2337 /**
2338  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2339  * @xprt: rpc_xprt struct containing statistics
2340  * @seq: output file
2341  *
2342  */
2343 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2344 {
2345 	long idle_time = 0;
2346 
2347 	if (xprt_connected(xprt))
2348 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2349 
2350 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2351 			"%llu %llu %lu %llu %llu\n",
2352 			xprt->stat.bind_count,
2353 			xprt->stat.connect_count,
2354 			xprt->stat.connect_time,
2355 			idle_time,
2356 			xprt->stat.sends,
2357 			xprt->stat.recvs,
2358 			xprt->stat.bad_xids,
2359 			xprt->stat.req_u,
2360 			xprt->stat.bklog_u,
2361 			xprt->stat.max_slots,
2362 			xprt->stat.sending_u,
2363 			xprt->stat.pending_u);
2364 }
2365 
2366 /**
2367  * xs_udp_print_stats - display UDP socket-specifc stats
2368  * @xprt: rpc_xprt struct containing statistics
2369  * @seq: output file
2370  *
2371  */
2372 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2373 {
2374 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2375 
2376 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2377 			"%lu %llu %llu\n",
2378 			transport->srcport,
2379 			xprt->stat.bind_count,
2380 			xprt->stat.sends,
2381 			xprt->stat.recvs,
2382 			xprt->stat.bad_xids,
2383 			xprt->stat.req_u,
2384 			xprt->stat.bklog_u,
2385 			xprt->stat.max_slots,
2386 			xprt->stat.sending_u,
2387 			xprt->stat.pending_u);
2388 }
2389 
2390 /**
2391  * xs_tcp_print_stats - display TCP socket-specifc stats
2392  * @xprt: rpc_xprt struct containing statistics
2393  * @seq: output file
2394  *
2395  */
2396 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2397 {
2398 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2399 	long idle_time = 0;
2400 
2401 	if (xprt_connected(xprt))
2402 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2403 
2404 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2405 			"%llu %llu %lu %llu %llu\n",
2406 			transport->srcport,
2407 			xprt->stat.bind_count,
2408 			xprt->stat.connect_count,
2409 			xprt->stat.connect_time,
2410 			idle_time,
2411 			xprt->stat.sends,
2412 			xprt->stat.recvs,
2413 			xprt->stat.bad_xids,
2414 			xprt->stat.req_u,
2415 			xprt->stat.bklog_u,
2416 			xprt->stat.max_slots,
2417 			xprt->stat.sending_u,
2418 			xprt->stat.pending_u);
2419 }
2420 
2421 /*
2422  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2423  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2424  * to use the server side send routines.
2425  */
2426 static void *bc_malloc(struct rpc_task *task, size_t size)
2427 {
2428 	struct page *page;
2429 	struct rpc_buffer *buf;
2430 
2431 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2432 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2433 		return NULL;
2434 
2435 	page = alloc_page(GFP_KERNEL);
2436 	if (!page)
2437 		return NULL;
2438 
2439 	buf = page_address(page);
2440 	buf->len = PAGE_SIZE;
2441 
2442 	return buf->data;
2443 }
2444 
2445 /*
2446  * Free the space allocated in the bc_alloc routine
2447  */
2448 static void bc_free(void *buffer)
2449 {
2450 	struct rpc_buffer *buf;
2451 
2452 	if (!buffer)
2453 		return;
2454 
2455 	buf = container_of(buffer, struct rpc_buffer, data);
2456 	free_page((unsigned long)buf);
2457 }
2458 
2459 /*
2460  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2461  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2462  */
2463 static int bc_sendto(struct rpc_rqst *req)
2464 {
2465 	int len;
2466 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2467 	struct rpc_xprt *xprt = req->rq_xprt;
2468 	struct sock_xprt *transport =
2469 				container_of(xprt, struct sock_xprt, xprt);
2470 	struct socket *sock = transport->sock;
2471 	unsigned long headoff;
2472 	unsigned long tailoff;
2473 
2474 	xs_encode_stream_record_marker(xbufp);
2475 
2476 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2477 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2478 	len = svc_send_common(sock, xbufp,
2479 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2480 			      xbufp->tail[0].iov_base, tailoff);
2481 
2482 	if (len != xbufp->len) {
2483 		printk(KERN_NOTICE "Error sending entire callback!\n");
2484 		len = -EAGAIN;
2485 	}
2486 
2487 	return len;
2488 }
2489 
2490 /*
2491  * The send routine. Borrows from svc_send
2492  */
2493 static int bc_send_request(struct rpc_task *task)
2494 {
2495 	struct rpc_rqst *req = task->tk_rqstp;
2496 	struct svc_xprt	*xprt;
2497 	u32                     len;
2498 
2499 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2500 	/*
2501 	 * Get the server socket associated with this callback xprt
2502 	 */
2503 	xprt = req->rq_xprt->bc_xprt;
2504 
2505 	/*
2506 	 * Grab the mutex to serialize data as the connection is shared
2507 	 * with the fore channel
2508 	 */
2509 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2510 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2511 		if (!mutex_trylock(&xprt->xpt_mutex))
2512 			return -EAGAIN;
2513 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2514 	}
2515 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2516 		len = -ENOTCONN;
2517 	else
2518 		len = bc_sendto(req);
2519 	mutex_unlock(&xprt->xpt_mutex);
2520 
2521 	if (len > 0)
2522 		len = 0;
2523 
2524 	return len;
2525 }
2526 
2527 /*
2528  * The close routine. Since this is client initiated, we do nothing
2529  */
2530 
2531 static void bc_close(struct rpc_xprt *xprt)
2532 {
2533 }
2534 
2535 /*
2536  * The xprt destroy routine. Again, because this connection is client
2537  * initiated, we do nothing
2538  */
2539 
2540 static void bc_destroy(struct rpc_xprt *xprt)
2541 {
2542 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2543 
2544 	xs_xprt_free(xprt);
2545 	module_put(THIS_MODULE);
2546 }
2547 
2548 static struct rpc_xprt_ops xs_local_ops = {
2549 	.reserve_xprt		= xprt_reserve_xprt,
2550 	.release_xprt		= xs_tcp_release_xprt,
2551 	.alloc_slot		= xprt_alloc_slot,
2552 	.rpcbind		= xs_local_rpcbind,
2553 	.set_port		= xs_local_set_port,
2554 	.connect		= xs_local_connect,
2555 	.buf_alloc		= rpc_malloc,
2556 	.buf_free		= rpc_free,
2557 	.send_request		= xs_local_send_request,
2558 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2559 	.close			= xs_close,
2560 	.destroy		= xs_destroy,
2561 	.print_stats		= xs_local_print_stats,
2562 };
2563 
2564 static struct rpc_xprt_ops xs_udp_ops = {
2565 	.set_buffer_size	= xs_udp_set_buffer_size,
2566 	.reserve_xprt		= xprt_reserve_xprt_cong,
2567 	.release_xprt		= xprt_release_xprt_cong,
2568 	.alloc_slot		= xprt_alloc_slot,
2569 	.rpcbind		= rpcb_getport_async,
2570 	.set_port		= xs_set_port,
2571 	.connect		= xs_connect,
2572 	.buf_alloc		= rpc_malloc,
2573 	.buf_free		= rpc_free,
2574 	.send_request		= xs_udp_send_request,
2575 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2576 	.timer			= xs_udp_timer,
2577 	.release_request	= xprt_release_rqst_cong,
2578 	.close			= xs_close,
2579 	.destroy		= xs_destroy,
2580 	.print_stats		= xs_udp_print_stats,
2581 };
2582 
2583 static struct rpc_xprt_ops xs_tcp_ops = {
2584 	.reserve_xprt		= xprt_reserve_xprt,
2585 	.release_xprt		= xs_tcp_release_xprt,
2586 	.alloc_slot		= xprt_lock_and_alloc_slot,
2587 	.rpcbind		= rpcb_getport_async,
2588 	.set_port		= xs_set_port,
2589 	.connect		= xs_connect,
2590 	.buf_alloc		= rpc_malloc,
2591 	.buf_free		= rpc_free,
2592 	.send_request		= xs_tcp_send_request,
2593 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2594 	.close			= xs_tcp_close,
2595 	.destroy		= xs_destroy,
2596 	.print_stats		= xs_tcp_print_stats,
2597 };
2598 
2599 /*
2600  * The rpc_xprt_ops for the server backchannel
2601  */
2602 
2603 static struct rpc_xprt_ops bc_tcp_ops = {
2604 	.reserve_xprt		= xprt_reserve_xprt,
2605 	.release_xprt		= xprt_release_xprt,
2606 	.alloc_slot		= xprt_alloc_slot,
2607 	.buf_alloc		= bc_malloc,
2608 	.buf_free		= bc_free,
2609 	.send_request		= bc_send_request,
2610 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2611 	.close			= bc_close,
2612 	.destroy		= bc_destroy,
2613 	.print_stats		= xs_tcp_print_stats,
2614 };
2615 
2616 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2617 {
2618 	static const struct sockaddr_in sin = {
2619 		.sin_family		= AF_INET,
2620 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2621 	};
2622 	static const struct sockaddr_in6 sin6 = {
2623 		.sin6_family		= AF_INET6,
2624 		.sin6_addr		= IN6ADDR_ANY_INIT,
2625 	};
2626 
2627 	switch (family) {
2628 	case AF_LOCAL:
2629 		break;
2630 	case AF_INET:
2631 		memcpy(sap, &sin, sizeof(sin));
2632 		break;
2633 	case AF_INET6:
2634 		memcpy(sap, &sin6, sizeof(sin6));
2635 		break;
2636 	default:
2637 		dprintk("RPC:       %s: Bad address family\n", __func__);
2638 		return -EAFNOSUPPORT;
2639 	}
2640 	return 0;
2641 }
2642 
2643 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2644 				      unsigned int slot_table_size,
2645 				      unsigned int max_slot_table_size)
2646 {
2647 	struct rpc_xprt *xprt;
2648 	struct sock_xprt *new;
2649 
2650 	if (args->addrlen > sizeof(xprt->addr)) {
2651 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2652 		return ERR_PTR(-EBADF);
2653 	}
2654 
2655 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2656 			max_slot_table_size);
2657 	if (xprt == NULL) {
2658 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2659 				"rpc_xprt\n");
2660 		return ERR_PTR(-ENOMEM);
2661 	}
2662 
2663 	new = container_of(xprt, struct sock_xprt, xprt);
2664 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2665 	xprt->addrlen = args->addrlen;
2666 	if (args->srcaddr)
2667 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2668 	else {
2669 		int err;
2670 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2671 					(struct sockaddr *)&new->srcaddr);
2672 		if (err != 0) {
2673 			xprt_free(xprt);
2674 			return ERR_PTR(err);
2675 		}
2676 	}
2677 
2678 	return xprt;
2679 }
2680 
2681 static const struct rpc_timeout xs_local_default_timeout = {
2682 	.to_initval = 10 * HZ,
2683 	.to_maxval = 10 * HZ,
2684 	.to_retries = 2,
2685 };
2686 
2687 /**
2688  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2689  * @args: rpc transport creation arguments
2690  *
2691  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2692  */
2693 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2694 {
2695 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2696 	struct sock_xprt *transport;
2697 	struct rpc_xprt *xprt;
2698 	struct rpc_xprt *ret;
2699 
2700 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2701 			xprt_max_tcp_slot_table_entries);
2702 	if (IS_ERR(xprt))
2703 		return xprt;
2704 	transport = container_of(xprt, struct sock_xprt, xprt);
2705 
2706 	xprt->prot = 0;
2707 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2708 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2709 
2710 	xprt->bind_timeout = XS_BIND_TO;
2711 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2712 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2713 
2714 	xprt->ops = &xs_local_ops;
2715 	xprt->timeout = &xs_local_default_timeout;
2716 
2717 	INIT_DELAYED_WORK(&transport->connect_worker,
2718 			xs_dummy_setup_socket);
2719 
2720 	switch (sun->sun_family) {
2721 	case AF_LOCAL:
2722 		if (sun->sun_path[0] != '/') {
2723 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2724 					sun->sun_path);
2725 			ret = ERR_PTR(-EINVAL);
2726 			goto out_err;
2727 		}
2728 		xprt_set_bound(xprt);
2729 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2730 		ret = ERR_PTR(xs_local_setup_socket(transport));
2731 		if (ret)
2732 			goto out_err;
2733 		break;
2734 	default:
2735 		ret = ERR_PTR(-EAFNOSUPPORT);
2736 		goto out_err;
2737 	}
2738 
2739 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2740 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2741 
2742 	if (try_module_get(THIS_MODULE))
2743 		return xprt;
2744 	ret = ERR_PTR(-EINVAL);
2745 out_err:
2746 	xs_xprt_free(xprt);
2747 	return ret;
2748 }
2749 
2750 static const struct rpc_timeout xs_udp_default_timeout = {
2751 	.to_initval = 5 * HZ,
2752 	.to_maxval = 30 * HZ,
2753 	.to_increment = 5 * HZ,
2754 	.to_retries = 5,
2755 };
2756 
2757 /**
2758  * xs_setup_udp - Set up transport to use a UDP socket
2759  * @args: rpc transport creation arguments
2760  *
2761  */
2762 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2763 {
2764 	struct sockaddr *addr = args->dstaddr;
2765 	struct rpc_xprt *xprt;
2766 	struct sock_xprt *transport;
2767 	struct rpc_xprt *ret;
2768 
2769 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2770 			xprt_udp_slot_table_entries);
2771 	if (IS_ERR(xprt))
2772 		return xprt;
2773 	transport = container_of(xprt, struct sock_xprt, xprt);
2774 
2775 	xprt->prot = IPPROTO_UDP;
2776 	xprt->tsh_size = 0;
2777 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2778 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2779 
2780 	xprt->bind_timeout = XS_BIND_TO;
2781 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2782 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2783 
2784 	xprt->ops = &xs_udp_ops;
2785 
2786 	xprt->timeout = &xs_udp_default_timeout;
2787 
2788 	switch (addr->sa_family) {
2789 	case AF_INET:
2790 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2791 			xprt_set_bound(xprt);
2792 
2793 		INIT_DELAYED_WORK(&transport->connect_worker,
2794 					xs_udp_setup_socket);
2795 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2796 		break;
2797 	case AF_INET6:
2798 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2799 			xprt_set_bound(xprt);
2800 
2801 		INIT_DELAYED_WORK(&transport->connect_worker,
2802 					xs_udp_setup_socket);
2803 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2804 		break;
2805 	default:
2806 		ret = ERR_PTR(-EAFNOSUPPORT);
2807 		goto out_err;
2808 	}
2809 
2810 	if (xprt_bound(xprt))
2811 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2812 				xprt->address_strings[RPC_DISPLAY_ADDR],
2813 				xprt->address_strings[RPC_DISPLAY_PORT],
2814 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2815 	else
2816 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2817 				xprt->address_strings[RPC_DISPLAY_ADDR],
2818 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2819 
2820 	if (try_module_get(THIS_MODULE))
2821 		return xprt;
2822 	ret = ERR_PTR(-EINVAL);
2823 out_err:
2824 	xs_xprt_free(xprt);
2825 	return ret;
2826 }
2827 
2828 static const struct rpc_timeout xs_tcp_default_timeout = {
2829 	.to_initval = 60 * HZ,
2830 	.to_maxval = 60 * HZ,
2831 	.to_retries = 2,
2832 };
2833 
2834 /**
2835  * xs_setup_tcp - Set up transport to use a TCP socket
2836  * @args: rpc transport creation arguments
2837  *
2838  */
2839 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2840 {
2841 	struct sockaddr *addr = args->dstaddr;
2842 	struct rpc_xprt *xprt;
2843 	struct sock_xprt *transport;
2844 	struct rpc_xprt *ret;
2845 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2846 
2847 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2848 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2849 
2850 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2851 			max_slot_table_size);
2852 	if (IS_ERR(xprt))
2853 		return xprt;
2854 	transport = container_of(xprt, struct sock_xprt, xprt);
2855 
2856 	xprt->prot = IPPROTO_TCP;
2857 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2858 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2859 
2860 	xprt->bind_timeout = XS_BIND_TO;
2861 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2862 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2863 
2864 	xprt->ops = &xs_tcp_ops;
2865 	xprt->timeout = &xs_tcp_default_timeout;
2866 
2867 	switch (addr->sa_family) {
2868 	case AF_INET:
2869 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2870 			xprt_set_bound(xprt);
2871 
2872 		INIT_DELAYED_WORK(&transport->connect_worker,
2873 					xs_tcp_setup_socket);
2874 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2875 		break;
2876 	case AF_INET6:
2877 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2878 			xprt_set_bound(xprt);
2879 
2880 		INIT_DELAYED_WORK(&transport->connect_worker,
2881 					xs_tcp_setup_socket);
2882 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2883 		break;
2884 	default:
2885 		ret = ERR_PTR(-EAFNOSUPPORT);
2886 		goto out_err;
2887 	}
2888 
2889 	if (xprt_bound(xprt))
2890 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2891 				xprt->address_strings[RPC_DISPLAY_ADDR],
2892 				xprt->address_strings[RPC_DISPLAY_PORT],
2893 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2894 	else
2895 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2896 				xprt->address_strings[RPC_DISPLAY_ADDR],
2897 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2898 
2899 	if (try_module_get(THIS_MODULE))
2900 		return xprt;
2901 	ret = ERR_PTR(-EINVAL);
2902 out_err:
2903 	xs_xprt_free(xprt);
2904 	return ret;
2905 }
2906 
2907 /**
2908  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2909  * @args: rpc transport creation arguments
2910  *
2911  */
2912 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2913 {
2914 	struct sockaddr *addr = args->dstaddr;
2915 	struct rpc_xprt *xprt;
2916 	struct sock_xprt *transport;
2917 	struct svc_sock *bc_sock;
2918 	struct rpc_xprt *ret;
2919 
2920 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2921 			xprt_tcp_slot_table_entries);
2922 	if (IS_ERR(xprt))
2923 		return xprt;
2924 	transport = container_of(xprt, struct sock_xprt, xprt);
2925 
2926 	xprt->prot = IPPROTO_TCP;
2927 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2928 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2929 	xprt->timeout = &xs_tcp_default_timeout;
2930 
2931 	/* backchannel */
2932 	xprt_set_bound(xprt);
2933 	xprt->bind_timeout = 0;
2934 	xprt->reestablish_timeout = 0;
2935 	xprt->idle_timeout = 0;
2936 
2937 	xprt->ops = &bc_tcp_ops;
2938 
2939 	switch (addr->sa_family) {
2940 	case AF_INET:
2941 		xs_format_peer_addresses(xprt, "tcp",
2942 					 RPCBIND_NETID_TCP);
2943 		break;
2944 	case AF_INET6:
2945 		xs_format_peer_addresses(xprt, "tcp",
2946 				   RPCBIND_NETID_TCP6);
2947 		break;
2948 	default:
2949 		ret = ERR_PTR(-EAFNOSUPPORT);
2950 		goto out_err;
2951 	}
2952 
2953 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2954 			xprt->address_strings[RPC_DISPLAY_ADDR],
2955 			xprt->address_strings[RPC_DISPLAY_PORT],
2956 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2957 
2958 	/*
2959 	 * Once we've associated a backchannel xprt with a connection,
2960 	 * we want to keep it around as long as the connection lasts,
2961 	 * in case we need to start using it for a backchannel again;
2962 	 * this reference won't be dropped until bc_xprt is destroyed.
2963 	 */
2964 	xprt_get(xprt);
2965 	args->bc_xprt->xpt_bc_xprt = xprt;
2966 	xprt->bc_xprt = args->bc_xprt;
2967 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2968 	transport->sock = bc_sock->sk_sock;
2969 	transport->inet = bc_sock->sk_sk;
2970 
2971 	/*
2972 	 * Since we don't want connections for the backchannel, we set
2973 	 * the xprt status to connected
2974 	 */
2975 	xprt_set_connected(xprt);
2976 
2977 	if (try_module_get(THIS_MODULE))
2978 		return xprt;
2979 
2980 	args->bc_xprt->xpt_bc_xprt = NULL;
2981 	xprt_put(xprt);
2982 	ret = ERR_PTR(-EINVAL);
2983 out_err:
2984 	xs_xprt_free(xprt);
2985 	return ret;
2986 }
2987 
2988 static struct xprt_class	xs_local_transport = {
2989 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2990 	.name		= "named UNIX socket",
2991 	.owner		= THIS_MODULE,
2992 	.ident		= XPRT_TRANSPORT_LOCAL,
2993 	.setup		= xs_setup_local,
2994 };
2995 
2996 static struct xprt_class	xs_udp_transport = {
2997 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2998 	.name		= "udp",
2999 	.owner		= THIS_MODULE,
3000 	.ident		= XPRT_TRANSPORT_UDP,
3001 	.setup		= xs_setup_udp,
3002 };
3003 
3004 static struct xprt_class	xs_tcp_transport = {
3005 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3006 	.name		= "tcp",
3007 	.owner		= THIS_MODULE,
3008 	.ident		= XPRT_TRANSPORT_TCP,
3009 	.setup		= xs_setup_tcp,
3010 };
3011 
3012 static struct xprt_class	xs_bc_tcp_transport = {
3013 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3014 	.name		= "tcp NFSv4.1 backchannel",
3015 	.owner		= THIS_MODULE,
3016 	.ident		= XPRT_TRANSPORT_BC_TCP,
3017 	.setup		= xs_setup_bc_tcp,
3018 };
3019 
3020 /**
3021  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3022  *
3023  */
3024 int init_socket_xprt(void)
3025 {
3026 #ifdef RPC_DEBUG
3027 	if (!sunrpc_table_header)
3028 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3029 #endif
3030 
3031 	xprt_register_transport(&xs_local_transport);
3032 	xprt_register_transport(&xs_udp_transport);
3033 	xprt_register_transport(&xs_tcp_transport);
3034 	xprt_register_transport(&xs_bc_tcp_transport);
3035 
3036 	return 0;
3037 }
3038 
3039 /**
3040  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3041  *
3042  */
3043 void cleanup_socket_xprt(void)
3044 {
3045 #ifdef RPC_DEBUG
3046 	if (sunrpc_table_header) {
3047 		unregister_sysctl_table(sunrpc_table_header);
3048 		sunrpc_table_header = NULL;
3049 	}
3050 #endif
3051 
3052 	xprt_unregister_transport(&xs_local_transport);
3053 	xprt_unregister_transport(&xs_udp_transport);
3054 	xprt_unregister_transport(&xs_tcp_transport);
3055 	xprt_unregister_transport(&xs_bc_tcp_transport);
3056 }
3057 
3058 static int param_set_uint_minmax(const char *val,
3059 		const struct kernel_param *kp,
3060 		unsigned int min, unsigned int max)
3061 {
3062 	unsigned int num;
3063 	int ret;
3064 
3065 	if (!val)
3066 		return -EINVAL;
3067 	ret = kstrtouint(val, 0, &num);
3068 	if (ret == -EINVAL || num < min || num > max)
3069 		return -EINVAL;
3070 	*((unsigned int *)kp->arg) = num;
3071 	return 0;
3072 }
3073 
3074 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3075 {
3076 	return param_set_uint_minmax(val, kp,
3077 			RPC_MIN_RESVPORT,
3078 			RPC_MAX_RESVPORT);
3079 }
3080 
3081 static struct kernel_param_ops param_ops_portnr = {
3082 	.set = param_set_portnr,
3083 	.get = param_get_uint,
3084 };
3085 
3086 #define param_check_portnr(name, p) \
3087 	__param_check(name, p, unsigned int);
3088 
3089 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3090 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3091 
3092 static int param_set_slot_table_size(const char *val,
3093 				     const struct kernel_param *kp)
3094 {
3095 	return param_set_uint_minmax(val, kp,
3096 			RPC_MIN_SLOT_TABLE,
3097 			RPC_MAX_SLOT_TABLE);
3098 }
3099 
3100 static struct kernel_param_ops param_ops_slot_table_size = {
3101 	.set = param_set_slot_table_size,
3102 	.get = param_get_uint,
3103 };
3104 
3105 #define param_check_slot_table_size(name, p) \
3106 	__param_check(name, p, unsigned int);
3107 
3108 static int param_set_max_slot_table_size(const char *val,
3109 				     const struct kernel_param *kp)
3110 {
3111 	return param_set_uint_minmax(val, kp,
3112 			RPC_MIN_SLOT_TABLE,
3113 			RPC_MAX_SLOT_TABLE_LIMIT);
3114 }
3115 
3116 static struct kernel_param_ops param_ops_max_slot_table_size = {
3117 	.set = param_set_max_slot_table_size,
3118 	.get = param_get_uint,
3119 };
3120 
3121 #define param_check_max_slot_table_size(name, p) \
3122 	__param_check(name, p, unsigned int);
3123 
3124 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3125 		   slot_table_size, 0644);
3126 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3127 		   max_slot_table_size, 0644);
3128 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3129 		   slot_table_size, 0644);
3130 
3131