xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision afc98d90)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44 
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49 
50 #include <trace/events/sunrpc.h>
51 
52 #include "sunrpc.h"
53 
54 static void xs_close(struct rpc_xprt *xprt);
55 
56 /*
57  * xprtsock tunables
58  */
59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
62 
63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
65 
66 #define XS_TCP_LINGER_TO	(15U * HZ)
67 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
68 
69 /*
70  * We can register our own files under /proc/sys/sunrpc by
71  * calling register_sysctl_table() again.  The files in that
72  * directory become the union of all files registered there.
73  *
74  * We simply need to make sure that we don't collide with
75  * someone else's file names!
76  */
77 
78 #ifdef RPC_DEBUG
79 
80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
85 
86 static struct ctl_table_header *sunrpc_table_header;
87 
88 /*
89  * FIXME: changing the UDP slot table size should also resize the UDP
90  *        socket buffers for existing UDP transports
91  */
92 static struct ctl_table xs_tunables_table[] = {
93 	{
94 		.procname	= "udp_slot_table_entries",
95 		.data		= &xprt_udp_slot_table_entries,
96 		.maxlen		= sizeof(unsigned int),
97 		.mode		= 0644,
98 		.proc_handler	= proc_dointvec_minmax,
99 		.extra1		= &min_slot_table_size,
100 		.extra2		= &max_slot_table_size
101 	},
102 	{
103 		.procname	= "tcp_slot_table_entries",
104 		.data		= &xprt_tcp_slot_table_entries,
105 		.maxlen		= sizeof(unsigned int),
106 		.mode		= 0644,
107 		.proc_handler	= proc_dointvec_minmax,
108 		.extra1		= &min_slot_table_size,
109 		.extra2		= &max_slot_table_size
110 	},
111 	{
112 		.procname	= "tcp_max_slot_table_entries",
113 		.data		= &xprt_max_tcp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_tcp_slot_table_limit
119 	},
120 	{
121 		.procname	= "min_resvport",
122 		.data		= &xprt_min_resvport,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &xprt_min_resvport_limit,
127 		.extra2		= &xprt_max_resvport_limit
128 	},
129 	{
130 		.procname	= "max_resvport",
131 		.data		= &xprt_max_resvport,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &xprt_min_resvport_limit,
136 		.extra2		= &xprt_max_resvport_limit
137 	},
138 	{
139 		.procname	= "tcp_fin_timeout",
140 		.data		= &xs_tcp_fin_timeout,
141 		.maxlen		= sizeof(xs_tcp_fin_timeout),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_jiffies,
144 	},
145 	{ },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149 	{
150 		.procname	= "sunrpc",
151 		.mode		= 0555,
152 		.child		= xs_tunables_table
153 	},
154 	{ },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO		(60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO		(2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
180 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
188 
189 #ifdef RPC_DEBUG
190 # undef  RPC_DEBUG_DATA
191 # define RPCDBG_FACILITY	RPCDBG_TRANS
192 #endif
193 
194 #ifdef RPC_DEBUG_DATA
195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
196 {
197 	u8 *buf = (u8 *) packet;
198 	int j;
199 
200 	dprintk("RPC:       %s\n", msg);
201 	for (j = 0; j < count && j < 128; j += 4) {
202 		if (!(j & 31)) {
203 			if (j)
204 				dprintk("\n");
205 			dprintk("0x%04x ", j);
206 		}
207 		dprintk("%02x%02x%02x%02x ",
208 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
209 	}
210 	dprintk("\n");
211 }
212 #else
213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
214 {
215 	/* NOP */
216 }
217 #endif
218 
219 struct sock_xprt {
220 	struct rpc_xprt		xprt;
221 
222 	/*
223 	 * Network layer
224 	 */
225 	struct socket *		sock;
226 	struct sock *		inet;
227 
228 	/*
229 	 * State of TCP reply receive
230 	 */
231 	__be32			tcp_fraghdr,
232 				tcp_xid,
233 				tcp_calldir;
234 
235 	u32			tcp_offset,
236 				tcp_reclen;
237 
238 	unsigned long		tcp_copied,
239 				tcp_flags;
240 
241 	/*
242 	 * Connection of transports
243 	 */
244 	struct delayed_work	connect_worker;
245 	struct sockaddr_storage	srcaddr;
246 	unsigned short		srcport;
247 
248 	/*
249 	 * UDP socket buffer size parameters
250 	 */
251 	size_t			rcvsize,
252 				sndsize;
253 
254 	/*
255 	 * Saved socket callback addresses
256 	 */
257 	void			(*old_data_ready)(struct sock *, int);
258 	void			(*old_state_change)(struct sock *);
259 	void			(*old_write_space)(struct sock *);
260 	void			(*old_error_report)(struct sock *);
261 };
262 
263 /*
264  * TCP receive state flags
265  */
266 #define TCP_RCV_LAST_FRAG	(1UL << 0)
267 #define TCP_RCV_COPY_FRAGHDR	(1UL << 1)
268 #define TCP_RCV_COPY_XID	(1UL << 2)
269 #define TCP_RCV_COPY_DATA	(1UL << 3)
270 #define TCP_RCV_READ_CALLDIR	(1UL << 4)
271 #define TCP_RCV_COPY_CALLDIR	(1UL << 5)
272 
273 /*
274  * TCP RPC flags
275  */
276 #define TCP_RPC_REPLY		(1UL << 6)
277 
278 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
279 {
280 	return (struct rpc_xprt *) sk->sk_user_data;
281 }
282 
283 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
284 {
285 	return (struct sockaddr *) &xprt->addr;
286 }
287 
288 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
289 {
290 	return (struct sockaddr_un *) &xprt->addr;
291 }
292 
293 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
294 {
295 	return (struct sockaddr_in *) &xprt->addr;
296 }
297 
298 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
299 {
300 	return (struct sockaddr_in6 *) &xprt->addr;
301 }
302 
303 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
304 {
305 	struct sockaddr *sap = xs_addr(xprt);
306 	struct sockaddr_in6 *sin6;
307 	struct sockaddr_in *sin;
308 	struct sockaddr_un *sun;
309 	char buf[128];
310 
311 	switch (sap->sa_family) {
312 	case AF_LOCAL:
313 		sun = xs_addr_un(xprt);
314 		strlcpy(buf, sun->sun_path, sizeof(buf));
315 		xprt->address_strings[RPC_DISPLAY_ADDR] =
316 						kstrdup(buf, GFP_KERNEL);
317 		break;
318 	case AF_INET:
319 		(void)rpc_ntop(sap, buf, sizeof(buf));
320 		xprt->address_strings[RPC_DISPLAY_ADDR] =
321 						kstrdup(buf, GFP_KERNEL);
322 		sin = xs_addr_in(xprt);
323 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
324 		break;
325 	case AF_INET6:
326 		(void)rpc_ntop(sap, buf, sizeof(buf));
327 		xprt->address_strings[RPC_DISPLAY_ADDR] =
328 						kstrdup(buf, GFP_KERNEL);
329 		sin6 = xs_addr_in6(xprt);
330 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
331 		break;
332 	default:
333 		BUG();
334 	}
335 
336 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
337 }
338 
339 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
340 {
341 	struct sockaddr *sap = xs_addr(xprt);
342 	char buf[128];
343 
344 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
345 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
346 
347 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
348 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
349 }
350 
351 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
352 				     const char *protocol,
353 				     const char *netid)
354 {
355 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
356 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
357 	xs_format_common_peer_addresses(xprt);
358 	xs_format_common_peer_ports(xprt);
359 }
360 
361 static void xs_update_peer_port(struct rpc_xprt *xprt)
362 {
363 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
364 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
365 
366 	xs_format_common_peer_ports(xprt);
367 }
368 
369 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
370 {
371 	unsigned int i;
372 
373 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
374 		switch (i) {
375 		case RPC_DISPLAY_PROTO:
376 		case RPC_DISPLAY_NETID:
377 			continue;
378 		default:
379 			kfree(xprt->address_strings[i]);
380 		}
381 }
382 
383 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
384 
385 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
386 {
387 	struct msghdr msg = {
388 		.msg_name	= addr,
389 		.msg_namelen	= addrlen,
390 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
391 	};
392 	struct kvec iov = {
393 		.iov_base	= vec->iov_base + base,
394 		.iov_len	= vec->iov_len - base,
395 	};
396 
397 	if (iov.iov_len != 0)
398 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
399 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
400 }
401 
402 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy)
403 {
404 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
405 			int offset, size_t size, int flags);
406 	struct page **ppage;
407 	unsigned int remainder;
408 	int err, sent = 0;
409 
410 	remainder = xdr->page_len - base;
411 	base += xdr->page_base;
412 	ppage = xdr->pages + (base >> PAGE_SHIFT);
413 	base &= ~PAGE_MASK;
414 	do_sendpage = sock->ops->sendpage;
415 	if (!zerocopy)
416 		do_sendpage = sock_no_sendpage;
417 	for(;;) {
418 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
419 		int flags = XS_SENDMSG_FLAGS;
420 
421 		remainder -= len;
422 		if (remainder != 0 || more)
423 			flags |= MSG_MORE;
424 		err = do_sendpage(sock, *ppage, base, len, flags);
425 		if (remainder == 0 || err != len)
426 			break;
427 		sent += err;
428 		ppage++;
429 		base = 0;
430 	}
431 	if (sent == 0)
432 		return err;
433 	if (err > 0)
434 		sent += err;
435 	return sent;
436 }
437 
438 /**
439  * xs_sendpages - write pages directly to a socket
440  * @sock: socket to send on
441  * @addr: UDP only -- address of destination
442  * @addrlen: UDP only -- length of destination address
443  * @xdr: buffer containing this request
444  * @base: starting position in the buffer
445  * @zerocopy: true if it is safe to use sendpage()
446  *
447  */
448 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy)
449 {
450 	unsigned int remainder = xdr->len - base;
451 	int err, sent = 0;
452 
453 	if (unlikely(!sock))
454 		return -ENOTSOCK;
455 
456 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
457 	if (base != 0) {
458 		addr = NULL;
459 		addrlen = 0;
460 	}
461 
462 	if (base < xdr->head[0].iov_len || addr != NULL) {
463 		unsigned int len = xdr->head[0].iov_len - base;
464 		remainder -= len;
465 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
466 		if (remainder == 0 || err != len)
467 			goto out;
468 		sent += err;
469 		base = 0;
470 	} else
471 		base -= xdr->head[0].iov_len;
472 
473 	if (base < xdr->page_len) {
474 		unsigned int len = xdr->page_len - base;
475 		remainder -= len;
476 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy);
477 		if (remainder == 0 || err != len)
478 			goto out;
479 		sent += err;
480 		base = 0;
481 	} else
482 		base -= xdr->page_len;
483 
484 	if (base >= xdr->tail[0].iov_len)
485 		return sent;
486 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
487 out:
488 	if (sent == 0)
489 		return err;
490 	if (err > 0)
491 		sent += err;
492 	return sent;
493 }
494 
495 static void xs_nospace_callback(struct rpc_task *task)
496 {
497 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
498 
499 	transport->inet->sk_write_pending--;
500 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
501 }
502 
503 /**
504  * xs_nospace - place task on wait queue if transmit was incomplete
505  * @task: task to put to sleep
506  *
507  */
508 static int xs_nospace(struct rpc_task *task)
509 {
510 	struct rpc_rqst *req = task->tk_rqstp;
511 	struct rpc_xprt *xprt = req->rq_xprt;
512 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
513 	int ret = -EAGAIN;
514 
515 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
516 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
517 			req->rq_slen);
518 
519 	/* Protect against races with write_space */
520 	spin_lock_bh(&xprt->transport_lock);
521 
522 	/* Don't race with disconnect */
523 	if (xprt_connected(xprt)) {
524 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
525 			/*
526 			 * Notify TCP that we're limited by the application
527 			 * window size
528 			 */
529 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
530 			transport->inet->sk_write_pending++;
531 			/* ...and wait for more buffer space */
532 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
533 		}
534 	} else {
535 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
536 		ret = -ENOTCONN;
537 	}
538 
539 	spin_unlock_bh(&xprt->transport_lock);
540 	return ret;
541 }
542 
543 /*
544  * Construct a stream transport record marker in @buf.
545  */
546 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
547 {
548 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
549 	rpc_fraghdr *base = buf->head[0].iov_base;
550 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
551 }
552 
553 /**
554  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
555  * @task: RPC task that manages the state of an RPC request
556  *
557  * Return values:
558  *        0:	The request has been sent
559  *   EAGAIN:	The socket was blocked, please call again later to
560  *		complete the request
561  * ENOTCONN:	Caller needs to invoke connect logic then call again
562  *    other:	Some other error occured, the request was not sent
563  */
564 static int xs_local_send_request(struct rpc_task *task)
565 {
566 	struct rpc_rqst *req = task->tk_rqstp;
567 	struct rpc_xprt *xprt = req->rq_xprt;
568 	struct sock_xprt *transport =
569 				container_of(xprt, struct sock_xprt, xprt);
570 	struct xdr_buf *xdr = &req->rq_snd_buf;
571 	int status;
572 
573 	xs_encode_stream_record_marker(&req->rq_snd_buf);
574 
575 	xs_pktdump("packet data:",
576 			req->rq_svec->iov_base, req->rq_svec->iov_len);
577 
578 	status = xs_sendpages(transport->sock, NULL, 0,
579 						xdr, req->rq_bytes_sent, true);
580 	dprintk("RPC:       %s(%u) = %d\n",
581 			__func__, xdr->len - req->rq_bytes_sent, status);
582 	if (likely(status >= 0)) {
583 		req->rq_bytes_sent += status;
584 		req->rq_xmit_bytes_sent += status;
585 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
586 			req->rq_bytes_sent = 0;
587 			return 0;
588 		}
589 		status = -EAGAIN;
590 	}
591 
592 	switch (status) {
593 	case -EAGAIN:
594 		status = xs_nospace(task);
595 		break;
596 	default:
597 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
598 			-status);
599 	case -EPIPE:
600 		xs_close(xprt);
601 		status = -ENOTCONN;
602 	}
603 
604 	return status;
605 }
606 
607 /**
608  * xs_udp_send_request - write an RPC request to a UDP socket
609  * @task: address of RPC task that manages the state of an RPC request
610  *
611  * Return values:
612  *        0:	The request has been sent
613  *   EAGAIN:	The socket was blocked, please call again later to
614  *		complete the request
615  * ENOTCONN:	Caller needs to invoke connect logic then call again
616  *    other:	Some other error occurred, the request was not sent
617  */
618 static int xs_udp_send_request(struct rpc_task *task)
619 {
620 	struct rpc_rqst *req = task->tk_rqstp;
621 	struct rpc_xprt *xprt = req->rq_xprt;
622 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
623 	struct xdr_buf *xdr = &req->rq_snd_buf;
624 	int status;
625 
626 	xs_pktdump("packet data:",
627 				req->rq_svec->iov_base,
628 				req->rq_svec->iov_len);
629 
630 	if (!xprt_bound(xprt))
631 		return -ENOTCONN;
632 	status = xs_sendpages(transport->sock,
633 			      xs_addr(xprt),
634 			      xprt->addrlen, xdr,
635 			      req->rq_bytes_sent, true);
636 
637 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
638 			xdr->len - req->rq_bytes_sent, status);
639 
640 	if (status >= 0) {
641 		req->rq_xmit_bytes_sent += status;
642 		if (status >= req->rq_slen)
643 			return 0;
644 		/* Still some bytes left; set up for a retry later. */
645 		status = -EAGAIN;
646 	}
647 
648 	switch (status) {
649 	case -ENOTSOCK:
650 		status = -ENOTCONN;
651 		/* Should we call xs_close() here? */
652 		break;
653 	case -EAGAIN:
654 		status = xs_nospace(task);
655 		break;
656 	default:
657 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
658 			-status);
659 	case -ENETUNREACH:
660 	case -EPIPE:
661 	case -ECONNREFUSED:
662 		/* When the server has died, an ICMP port unreachable message
663 		 * prompts ECONNREFUSED. */
664 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
665 	}
666 
667 	return status;
668 }
669 
670 /**
671  * xs_tcp_shutdown - gracefully shut down a TCP socket
672  * @xprt: transport
673  *
674  * Initiates a graceful shutdown of the TCP socket by calling the
675  * equivalent of shutdown(SHUT_WR);
676  */
677 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
678 {
679 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
680 	struct socket *sock = transport->sock;
681 
682 	if (sock != NULL) {
683 		kernel_sock_shutdown(sock, SHUT_WR);
684 		trace_rpc_socket_shutdown(xprt, sock);
685 	}
686 }
687 
688 /**
689  * xs_tcp_send_request - write an RPC request to a TCP socket
690  * @task: address of RPC task that manages the state of an RPC request
691  *
692  * Return values:
693  *        0:	The request has been sent
694  *   EAGAIN:	The socket was blocked, please call again later to
695  *		complete the request
696  * ENOTCONN:	Caller needs to invoke connect logic then call again
697  *    other:	Some other error occurred, the request was not sent
698  *
699  * XXX: In the case of soft timeouts, should we eventually give up
700  *	if sendmsg is not able to make progress?
701  */
702 static int xs_tcp_send_request(struct rpc_task *task)
703 {
704 	struct rpc_rqst *req = task->tk_rqstp;
705 	struct rpc_xprt *xprt = req->rq_xprt;
706 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
707 	struct xdr_buf *xdr = &req->rq_snd_buf;
708 	bool zerocopy = true;
709 	int status;
710 
711 	xs_encode_stream_record_marker(&req->rq_snd_buf);
712 
713 	xs_pktdump("packet data:",
714 				req->rq_svec->iov_base,
715 				req->rq_svec->iov_len);
716 	/* Don't use zero copy if this is a resend. If the RPC call
717 	 * completes while the socket holds a reference to the pages,
718 	 * then we may end up resending corrupted data.
719 	 */
720 	if (task->tk_flags & RPC_TASK_SENT)
721 		zerocopy = false;
722 
723 	/* Continue transmitting the packet/record. We must be careful
724 	 * to cope with writespace callbacks arriving _after_ we have
725 	 * called sendmsg(). */
726 	while (1) {
727 		status = xs_sendpages(transport->sock,
728 					NULL, 0, xdr, req->rq_bytes_sent,
729 					zerocopy);
730 
731 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
732 				xdr->len - req->rq_bytes_sent, status);
733 
734 		if (unlikely(status < 0))
735 			break;
736 
737 		/* If we've sent the entire packet, immediately
738 		 * reset the count of bytes sent. */
739 		req->rq_bytes_sent += status;
740 		req->rq_xmit_bytes_sent += status;
741 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
742 			req->rq_bytes_sent = 0;
743 			return 0;
744 		}
745 
746 		if (status != 0)
747 			continue;
748 		status = -EAGAIN;
749 		break;
750 	}
751 
752 	switch (status) {
753 	case -ENOTSOCK:
754 		status = -ENOTCONN;
755 		/* Should we call xs_close() here? */
756 		break;
757 	case -EAGAIN:
758 		status = xs_nospace(task);
759 		break;
760 	default:
761 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
762 			-status);
763 	case -ECONNRESET:
764 		xs_tcp_shutdown(xprt);
765 	case -ECONNREFUSED:
766 	case -ENOTCONN:
767 	case -EPIPE:
768 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
769 	}
770 
771 	return status;
772 }
773 
774 /**
775  * xs_tcp_release_xprt - clean up after a tcp transmission
776  * @xprt: transport
777  * @task: rpc task
778  *
779  * This cleans up if an error causes us to abort the transmission of a request.
780  * In this case, the socket may need to be reset in order to avoid confusing
781  * the server.
782  */
783 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
784 {
785 	struct rpc_rqst *req;
786 
787 	if (task != xprt->snd_task)
788 		return;
789 	if (task == NULL)
790 		goto out_release;
791 	req = task->tk_rqstp;
792 	if (req == NULL)
793 		goto out_release;
794 	if (req->rq_bytes_sent == 0)
795 		goto out_release;
796 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
797 		goto out_release;
798 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
799 out_release:
800 	xprt_release_xprt(xprt, task);
801 }
802 
803 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
804 {
805 	transport->old_data_ready = sk->sk_data_ready;
806 	transport->old_state_change = sk->sk_state_change;
807 	transport->old_write_space = sk->sk_write_space;
808 	transport->old_error_report = sk->sk_error_report;
809 }
810 
811 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
812 {
813 	sk->sk_data_ready = transport->old_data_ready;
814 	sk->sk_state_change = transport->old_state_change;
815 	sk->sk_write_space = transport->old_write_space;
816 	sk->sk_error_report = transport->old_error_report;
817 }
818 
819 /**
820  * xs_error_report - callback to handle TCP socket state errors
821  * @sk: socket
822  *
823  * Note: we don't call sock_error() since there may be a rpc_task
824  * using the socket, and so we don't want to clear sk->sk_err.
825  */
826 static void xs_error_report(struct sock *sk)
827 {
828 	struct rpc_xprt *xprt;
829 	int err;
830 
831 	read_lock_bh(&sk->sk_callback_lock);
832 	if (!(xprt = xprt_from_sock(sk)))
833 		goto out;
834 
835 	err = -sk->sk_err;
836 	if (err == 0)
837 		goto out;
838 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
839 			xprt, -err);
840 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
841 	xprt_wake_pending_tasks(xprt, err);
842  out:
843 	read_unlock_bh(&sk->sk_callback_lock);
844 }
845 
846 static void xs_reset_transport(struct sock_xprt *transport)
847 {
848 	struct socket *sock = transport->sock;
849 	struct sock *sk = transport->inet;
850 
851 	if (sk == NULL)
852 		return;
853 
854 	transport->srcport = 0;
855 
856 	write_lock_bh(&sk->sk_callback_lock);
857 	transport->inet = NULL;
858 	transport->sock = NULL;
859 
860 	sk->sk_user_data = NULL;
861 
862 	xs_restore_old_callbacks(transport, sk);
863 	write_unlock_bh(&sk->sk_callback_lock);
864 
865 	sk->sk_no_check = 0;
866 
867 	trace_rpc_socket_close(&transport->xprt, sock);
868 	sock_release(sock);
869 }
870 
871 /**
872  * xs_close - close a socket
873  * @xprt: transport
874  *
875  * This is used when all requests are complete; ie, no DRC state remains
876  * on the server we want to save.
877  *
878  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
879  * xs_reset_transport() zeroing the socket from underneath a writer.
880  */
881 static void xs_close(struct rpc_xprt *xprt)
882 {
883 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
884 
885 	dprintk("RPC:       xs_close xprt %p\n", xprt);
886 
887 	cancel_delayed_work_sync(&transport->connect_worker);
888 
889 	xs_reset_transport(transport);
890 	xprt->reestablish_timeout = 0;
891 
892 	smp_mb__before_clear_bit();
893 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
894 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
895 	clear_bit(XPRT_CLOSING, &xprt->state);
896 	smp_mb__after_clear_bit();
897 	xprt_disconnect_done(xprt);
898 }
899 
900 static void xs_tcp_close(struct rpc_xprt *xprt)
901 {
902 	if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
903 		xs_close(xprt);
904 	else
905 		xs_tcp_shutdown(xprt);
906 }
907 
908 /**
909  * xs_destroy - prepare to shutdown a transport
910  * @xprt: doomed transport
911  *
912  */
913 static void xs_destroy(struct rpc_xprt *xprt)
914 {
915 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
916 
917 	xs_close(xprt);
918 	xs_free_peer_addresses(xprt);
919 	xprt_free(xprt);
920 	module_put(THIS_MODULE);
921 }
922 
923 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
924 {
925 	struct xdr_skb_reader desc = {
926 		.skb		= skb,
927 		.offset		= sizeof(rpc_fraghdr),
928 		.count		= skb->len - sizeof(rpc_fraghdr),
929 	};
930 
931 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
932 		return -1;
933 	if (desc.count)
934 		return -1;
935 	return 0;
936 }
937 
938 /**
939  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
940  * @sk: socket with data to read
941  * @len: how much data to read
942  *
943  * Currently this assumes we can read the whole reply in a single gulp.
944  */
945 static void xs_local_data_ready(struct sock *sk, int len)
946 {
947 	struct rpc_task *task;
948 	struct rpc_xprt *xprt;
949 	struct rpc_rqst *rovr;
950 	struct sk_buff *skb;
951 	int err, repsize, copied;
952 	u32 _xid;
953 	__be32 *xp;
954 
955 	read_lock_bh(&sk->sk_callback_lock);
956 	dprintk("RPC:       %s...\n", __func__);
957 	xprt = xprt_from_sock(sk);
958 	if (xprt == NULL)
959 		goto out;
960 
961 	skb = skb_recv_datagram(sk, 0, 1, &err);
962 	if (skb == NULL)
963 		goto out;
964 
965 	repsize = skb->len - sizeof(rpc_fraghdr);
966 	if (repsize < 4) {
967 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
968 		goto dropit;
969 	}
970 
971 	/* Copy the XID from the skb... */
972 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
973 	if (xp == NULL)
974 		goto dropit;
975 
976 	/* Look up and lock the request corresponding to the given XID */
977 	spin_lock(&xprt->transport_lock);
978 	rovr = xprt_lookup_rqst(xprt, *xp);
979 	if (!rovr)
980 		goto out_unlock;
981 	task = rovr->rq_task;
982 
983 	copied = rovr->rq_private_buf.buflen;
984 	if (copied > repsize)
985 		copied = repsize;
986 
987 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
988 		dprintk("RPC:       sk_buff copy failed\n");
989 		goto out_unlock;
990 	}
991 
992 	xprt_complete_rqst(task, copied);
993 
994  out_unlock:
995 	spin_unlock(&xprt->transport_lock);
996  dropit:
997 	skb_free_datagram(sk, skb);
998  out:
999 	read_unlock_bh(&sk->sk_callback_lock);
1000 }
1001 
1002 /**
1003  * xs_udp_data_ready - "data ready" callback for UDP sockets
1004  * @sk: socket with data to read
1005  * @len: how much data to read
1006  *
1007  */
1008 static void xs_udp_data_ready(struct sock *sk, int len)
1009 {
1010 	struct rpc_task *task;
1011 	struct rpc_xprt *xprt;
1012 	struct rpc_rqst *rovr;
1013 	struct sk_buff *skb;
1014 	int err, repsize, copied;
1015 	u32 _xid;
1016 	__be32 *xp;
1017 
1018 	read_lock_bh(&sk->sk_callback_lock);
1019 	dprintk("RPC:       xs_udp_data_ready...\n");
1020 	if (!(xprt = xprt_from_sock(sk)))
1021 		goto out;
1022 
1023 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
1024 		goto out;
1025 
1026 	repsize = skb->len - sizeof(struct udphdr);
1027 	if (repsize < 4) {
1028 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1029 		goto dropit;
1030 	}
1031 
1032 	/* Copy the XID from the skb... */
1033 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
1034 				sizeof(_xid), &_xid);
1035 	if (xp == NULL)
1036 		goto dropit;
1037 
1038 	/* Look up and lock the request corresponding to the given XID */
1039 	spin_lock(&xprt->transport_lock);
1040 	rovr = xprt_lookup_rqst(xprt, *xp);
1041 	if (!rovr)
1042 		goto out_unlock;
1043 	task = rovr->rq_task;
1044 
1045 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1046 		copied = repsize;
1047 
1048 	/* Suck it into the iovec, verify checksum if not done by hw. */
1049 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1050 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1051 		goto out_unlock;
1052 	}
1053 
1054 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1055 
1056 	xprt_adjust_cwnd(xprt, task, copied);
1057 	xprt_complete_rqst(task, copied);
1058 
1059  out_unlock:
1060 	spin_unlock(&xprt->transport_lock);
1061  dropit:
1062 	skb_free_datagram(sk, skb);
1063  out:
1064 	read_unlock_bh(&sk->sk_callback_lock);
1065 }
1066 
1067 /*
1068  * Helper function to force a TCP close if the server is sending
1069  * junk and/or it has put us in CLOSE_WAIT
1070  */
1071 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1072 {
1073 	set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1074 	xprt_force_disconnect(xprt);
1075 }
1076 
1077 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1078 {
1079 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1080 	size_t len, used;
1081 	char *p;
1082 
1083 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1084 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1085 	used = xdr_skb_read_bits(desc, p, len);
1086 	transport->tcp_offset += used;
1087 	if (used != len)
1088 		return;
1089 
1090 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1091 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1092 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1093 	else
1094 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1095 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1096 
1097 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1098 	transport->tcp_offset = 0;
1099 
1100 	/* Sanity check of the record length */
1101 	if (unlikely(transport->tcp_reclen < 8)) {
1102 		dprintk("RPC:       invalid TCP record fragment length\n");
1103 		xs_tcp_force_close(xprt);
1104 		return;
1105 	}
1106 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1107 			transport->tcp_reclen);
1108 }
1109 
1110 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1111 {
1112 	if (transport->tcp_offset == transport->tcp_reclen) {
1113 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1114 		transport->tcp_offset = 0;
1115 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1116 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1117 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1118 			transport->tcp_copied = 0;
1119 		}
1120 	}
1121 }
1122 
1123 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1124 {
1125 	size_t len, used;
1126 	char *p;
1127 
1128 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1129 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1130 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1131 	used = xdr_skb_read_bits(desc, p, len);
1132 	transport->tcp_offset += used;
1133 	if (used != len)
1134 		return;
1135 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1136 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1137 	transport->tcp_copied = 4;
1138 	dprintk("RPC:       reading %s XID %08x\n",
1139 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1140 							      : "request with",
1141 			ntohl(transport->tcp_xid));
1142 	xs_tcp_check_fraghdr(transport);
1143 }
1144 
1145 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1146 				       struct xdr_skb_reader *desc)
1147 {
1148 	size_t len, used;
1149 	u32 offset;
1150 	char *p;
1151 
1152 	/*
1153 	 * We want transport->tcp_offset to be 8 at the end of this routine
1154 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1155 	 * When this function is called for the first time,
1156 	 * transport->tcp_offset is 4 (after having already read the xid).
1157 	 */
1158 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1159 	len = sizeof(transport->tcp_calldir) - offset;
1160 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1161 	p = ((char *) &transport->tcp_calldir) + offset;
1162 	used = xdr_skb_read_bits(desc, p, len);
1163 	transport->tcp_offset += used;
1164 	if (used != len)
1165 		return;
1166 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1167 	/*
1168 	 * We don't yet have the XDR buffer, so we will write the calldir
1169 	 * out after we get the buffer from the 'struct rpc_rqst'
1170 	 */
1171 	switch (ntohl(transport->tcp_calldir)) {
1172 	case RPC_REPLY:
1173 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1174 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1175 		transport->tcp_flags |= TCP_RPC_REPLY;
1176 		break;
1177 	case RPC_CALL:
1178 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1179 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1180 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1181 		break;
1182 	default:
1183 		dprintk("RPC:       invalid request message type\n");
1184 		xs_tcp_force_close(&transport->xprt);
1185 	}
1186 	xs_tcp_check_fraghdr(transport);
1187 }
1188 
1189 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1190 				     struct xdr_skb_reader *desc,
1191 				     struct rpc_rqst *req)
1192 {
1193 	struct sock_xprt *transport =
1194 				container_of(xprt, struct sock_xprt, xprt);
1195 	struct xdr_buf *rcvbuf;
1196 	size_t len;
1197 	ssize_t r;
1198 
1199 	rcvbuf = &req->rq_private_buf;
1200 
1201 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1202 		/*
1203 		 * Save the RPC direction in the XDR buffer
1204 		 */
1205 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1206 			&transport->tcp_calldir,
1207 			sizeof(transport->tcp_calldir));
1208 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1209 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1210 	}
1211 
1212 	len = desc->count;
1213 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1214 		struct xdr_skb_reader my_desc;
1215 
1216 		len = transport->tcp_reclen - transport->tcp_offset;
1217 		memcpy(&my_desc, desc, sizeof(my_desc));
1218 		my_desc.count = len;
1219 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1220 					  &my_desc, xdr_skb_read_bits);
1221 		desc->count -= r;
1222 		desc->offset += r;
1223 	} else
1224 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1225 					  desc, xdr_skb_read_bits);
1226 
1227 	if (r > 0) {
1228 		transport->tcp_copied += r;
1229 		transport->tcp_offset += r;
1230 	}
1231 	if (r != len) {
1232 		/* Error when copying to the receive buffer,
1233 		 * usually because we weren't able to allocate
1234 		 * additional buffer pages. All we can do now
1235 		 * is turn off TCP_RCV_COPY_DATA, so the request
1236 		 * will not receive any additional updates,
1237 		 * and time out.
1238 		 * Any remaining data from this record will
1239 		 * be discarded.
1240 		 */
1241 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1242 		dprintk("RPC:       XID %08x truncated request\n",
1243 				ntohl(transport->tcp_xid));
1244 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1245 				"tcp_offset = %u, tcp_reclen = %u\n",
1246 				xprt, transport->tcp_copied,
1247 				transport->tcp_offset, transport->tcp_reclen);
1248 		return;
1249 	}
1250 
1251 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1252 			ntohl(transport->tcp_xid), r);
1253 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1254 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1255 			transport->tcp_offset, transport->tcp_reclen);
1256 
1257 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1258 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1259 	else if (transport->tcp_offset == transport->tcp_reclen) {
1260 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1261 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1262 	}
1263 }
1264 
1265 /*
1266  * Finds the request corresponding to the RPC xid and invokes the common
1267  * tcp read code to read the data.
1268  */
1269 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1270 				    struct xdr_skb_reader *desc)
1271 {
1272 	struct sock_xprt *transport =
1273 				container_of(xprt, struct sock_xprt, xprt);
1274 	struct rpc_rqst *req;
1275 
1276 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1277 
1278 	/* Find and lock the request corresponding to this xid */
1279 	spin_lock(&xprt->transport_lock);
1280 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1281 	if (!req) {
1282 		dprintk("RPC:       XID %08x request not found!\n",
1283 				ntohl(transport->tcp_xid));
1284 		spin_unlock(&xprt->transport_lock);
1285 		return -1;
1286 	}
1287 
1288 	xs_tcp_read_common(xprt, desc, req);
1289 
1290 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1291 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1292 
1293 	spin_unlock(&xprt->transport_lock);
1294 	return 0;
1295 }
1296 
1297 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1298 /*
1299  * Obtains an rpc_rqst previously allocated and invokes the common
1300  * tcp read code to read the data.  The result is placed in the callback
1301  * queue.
1302  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1303  * connection and return -1.
1304  */
1305 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1306 				       struct xdr_skb_reader *desc)
1307 {
1308 	struct sock_xprt *transport =
1309 				container_of(xprt, struct sock_xprt, xprt);
1310 	struct rpc_rqst *req;
1311 
1312 	req = xprt_alloc_bc_request(xprt);
1313 	if (req == NULL) {
1314 		printk(KERN_WARNING "Callback slot table overflowed\n");
1315 		xprt_force_disconnect(xprt);
1316 		return -1;
1317 	}
1318 
1319 	req->rq_xid = transport->tcp_xid;
1320 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1321 	xs_tcp_read_common(xprt, desc, req);
1322 
1323 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1324 		struct svc_serv *bc_serv = xprt->bc_serv;
1325 
1326 		/*
1327 		 * Add callback request to callback list.  The callback
1328 		 * service sleeps on the sv_cb_waitq waiting for new
1329 		 * requests.  Wake it up after adding enqueing the
1330 		 * request.
1331 		 */
1332 		dprintk("RPC:       add callback request to list\n");
1333 		spin_lock(&bc_serv->sv_cb_lock);
1334 		list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1335 		spin_unlock(&bc_serv->sv_cb_lock);
1336 		wake_up(&bc_serv->sv_cb_waitq);
1337 	}
1338 
1339 	req->rq_private_buf.len = transport->tcp_copied;
1340 
1341 	return 0;
1342 }
1343 
1344 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1345 					struct xdr_skb_reader *desc)
1346 {
1347 	struct sock_xprt *transport =
1348 				container_of(xprt, struct sock_xprt, xprt);
1349 
1350 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1351 		xs_tcp_read_reply(xprt, desc) :
1352 		xs_tcp_read_callback(xprt, desc);
1353 }
1354 #else
1355 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1356 					struct xdr_skb_reader *desc)
1357 {
1358 	return xs_tcp_read_reply(xprt, desc);
1359 }
1360 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1361 
1362 /*
1363  * Read data off the transport.  This can be either an RPC_CALL or an
1364  * RPC_REPLY.  Relay the processing to helper functions.
1365  */
1366 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1367 				    struct xdr_skb_reader *desc)
1368 {
1369 	struct sock_xprt *transport =
1370 				container_of(xprt, struct sock_xprt, xprt);
1371 
1372 	if (_xs_tcp_read_data(xprt, desc) == 0)
1373 		xs_tcp_check_fraghdr(transport);
1374 	else {
1375 		/*
1376 		 * The transport_lock protects the request handling.
1377 		 * There's no need to hold it to update the tcp_flags.
1378 		 */
1379 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1380 	}
1381 }
1382 
1383 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1384 {
1385 	size_t len;
1386 
1387 	len = transport->tcp_reclen - transport->tcp_offset;
1388 	if (len > desc->count)
1389 		len = desc->count;
1390 	desc->count -= len;
1391 	desc->offset += len;
1392 	transport->tcp_offset += len;
1393 	dprintk("RPC:       discarded %Zu bytes\n", len);
1394 	xs_tcp_check_fraghdr(transport);
1395 }
1396 
1397 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1398 {
1399 	struct rpc_xprt *xprt = rd_desc->arg.data;
1400 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1401 	struct xdr_skb_reader desc = {
1402 		.skb	= skb,
1403 		.offset	= offset,
1404 		.count	= len,
1405 	};
1406 
1407 	dprintk("RPC:       xs_tcp_data_recv started\n");
1408 	do {
1409 		/* Read in a new fragment marker if necessary */
1410 		/* Can we ever really expect to get completely empty fragments? */
1411 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1412 			xs_tcp_read_fraghdr(xprt, &desc);
1413 			continue;
1414 		}
1415 		/* Read in the xid if necessary */
1416 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1417 			xs_tcp_read_xid(transport, &desc);
1418 			continue;
1419 		}
1420 		/* Read in the call/reply flag */
1421 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1422 			xs_tcp_read_calldir(transport, &desc);
1423 			continue;
1424 		}
1425 		/* Read in the request data */
1426 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1427 			xs_tcp_read_data(xprt, &desc);
1428 			continue;
1429 		}
1430 		/* Skip over any trailing bytes on short reads */
1431 		xs_tcp_read_discard(transport, &desc);
1432 	} while (desc.count);
1433 	dprintk("RPC:       xs_tcp_data_recv done\n");
1434 	return len - desc.count;
1435 }
1436 
1437 /**
1438  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1439  * @sk: socket with data to read
1440  * @bytes: how much data to read
1441  *
1442  */
1443 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1444 {
1445 	struct rpc_xprt *xprt;
1446 	read_descriptor_t rd_desc;
1447 	int read;
1448 
1449 	dprintk("RPC:       xs_tcp_data_ready...\n");
1450 
1451 	read_lock_bh(&sk->sk_callback_lock);
1452 	if (!(xprt = xprt_from_sock(sk)))
1453 		goto out;
1454 	/* Any data means we had a useful conversation, so
1455 	 * the we don't need to delay the next reconnect
1456 	 */
1457 	if (xprt->reestablish_timeout)
1458 		xprt->reestablish_timeout = 0;
1459 
1460 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1461 	rd_desc.arg.data = xprt;
1462 	do {
1463 		rd_desc.count = 65536;
1464 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1465 	} while (read > 0);
1466 out:
1467 	read_unlock_bh(&sk->sk_callback_lock);
1468 }
1469 
1470 /*
1471  * Do the equivalent of linger/linger2 handling for dealing with
1472  * broken servers that don't close the socket in a timely
1473  * fashion
1474  */
1475 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1476 		unsigned long timeout)
1477 {
1478 	struct sock_xprt *transport;
1479 
1480 	if (xprt_test_and_set_connecting(xprt))
1481 		return;
1482 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1483 	transport = container_of(xprt, struct sock_xprt, xprt);
1484 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1485 			   timeout);
1486 }
1487 
1488 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1489 {
1490 	struct sock_xprt *transport;
1491 
1492 	transport = container_of(xprt, struct sock_xprt, xprt);
1493 
1494 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1495 	    !cancel_delayed_work(&transport->connect_worker))
1496 		return;
1497 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1498 	xprt_clear_connecting(xprt);
1499 }
1500 
1501 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1502 {
1503 	smp_mb__before_clear_bit();
1504 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1505 	clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1506 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1507 	clear_bit(XPRT_CLOSING, &xprt->state);
1508 	smp_mb__after_clear_bit();
1509 }
1510 
1511 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1512 {
1513 	xs_sock_reset_connection_flags(xprt);
1514 	/* Mark transport as closed and wake up all pending tasks */
1515 	xprt_disconnect_done(xprt);
1516 }
1517 
1518 /**
1519  * xs_tcp_state_change - callback to handle TCP socket state changes
1520  * @sk: socket whose state has changed
1521  *
1522  */
1523 static void xs_tcp_state_change(struct sock *sk)
1524 {
1525 	struct rpc_xprt *xprt;
1526 
1527 	read_lock_bh(&sk->sk_callback_lock);
1528 	if (!(xprt = xprt_from_sock(sk)))
1529 		goto out;
1530 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1531 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1532 			sk->sk_state, xprt_connected(xprt),
1533 			sock_flag(sk, SOCK_DEAD),
1534 			sock_flag(sk, SOCK_ZAPPED),
1535 			sk->sk_shutdown);
1536 
1537 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1538 	switch (sk->sk_state) {
1539 	case TCP_ESTABLISHED:
1540 		spin_lock(&xprt->transport_lock);
1541 		if (!xprt_test_and_set_connected(xprt)) {
1542 			struct sock_xprt *transport = container_of(xprt,
1543 					struct sock_xprt, xprt);
1544 
1545 			/* Reset TCP record info */
1546 			transport->tcp_offset = 0;
1547 			transport->tcp_reclen = 0;
1548 			transport->tcp_copied = 0;
1549 			transport->tcp_flags =
1550 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1551 			xprt->connect_cookie++;
1552 
1553 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1554 		}
1555 		spin_unlock(&xprt->transport_lock);
1556 		break;
1557 	case TCP_FIN_WAIT1:
1558 		/* The client initiated a shutdown of the socket */
1559 		xprt->connect_cookie++;
1560 		xprt->reestablish_timeout = 0;
1561 		set_bit(XPRT_CLOSING, &xprt->state);
1562 		smp_mb__before_clear_bit();
1563 		clear_bit(XPRT_CONNECTED, &xprt->state);
1564 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1565 		smp_mb__after_clear_bit();
1566 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1567 		break;
1568 	case TCP_CLOSE_WAIT:
1569 		/* The server initiated a shutdown of the socket */
1570 		xprt->connect_cookie++;
1571 		clear_bit(XPRT_CONNECTED, &xprt->state);
1572 		xs_tcp_force_close(xprt);
1573 	case TCP_CLOSING:
1574 		/*
1575 		 * If the server closed down the connection, make sure that
1576 		 * we back off before reconnecting
1577 		 */
1578 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1579 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1580 		break;
1581 	case TCP_LAST_ACK:
1582 		set_bit(XPRT_CLOSING, &xprt->state);
1583 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1584 		smp_mb__before_clear_bit();
1585 		clear_bit(XPRT_CONNECTED, &xprt->state);
1586 		smp_mb__after_clear_bit();
1587 		break;
1588 	case TCP_CLOSE:
1589 		xs_tcp_cancel_linger_timeout(xprt);
1590 		xs_sock_mark_closed(xprt);
1591 	}
1592  out:
1593 	read_unlock_bh(&sk->sk_callback_lock);
1594 }
1595 
1596 static void xs_write_space(struct sock *sk)
1597 {
1598 	struct socket *sock;
1599 	struct rpc_xprt *xprt;
1600 
1601 	if (unlikely(!(sock = sk->sk_socket)))
1602 		return;
1603 	clear_bit(SOCK_NOSPACE, &sock->flags);
1604 
1605 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1606 		return;
1607 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1608 		return;
1609 
1610 	xprt_write_space(xprt);
1611 }
1612 
1613 /**
1614  * xs_udp_write_space - callback invoked when socket buffer space
1615  *                             becomes available
1616  * @sk: socket whose state has changed
1617  *
1618  * Called when more output buffer space is available for this socket.
1619  * We try not to wake our writers until they can make "significant"
1620  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1621  * with a bunch of small requests.
1622  */
1623 static void xs_udp_write_space(struct sock *sk)
1624 {
1625 	read_lock_bh(&sk->sk_callback_lock);
1626 
1627 	/* from net/core/sock.c:sock_def_write_space */
1628 	if (sock_writeable(sk))
1629 		xs_write_space(sk);
1630 
1631 	read_unlock_bh(&sk->sk_callback_lock);
1632 }
1633 
1634 /**
1635  * xs_tcp_write_space - callback invoked when socket buffer space
1636  *                             becomes available
1637  * @sk: socket whose state has changed
1638  *
1639  * Called when more output buffer space is available for this socket.
1640  * We try not to wake our writers until they can make "significant"
1641  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1642  * with a bunch of small requests.
1643  */
1644 static void xs_tcp_write_space(struct sock *sk)
1645 {
1646 	read_lock_bh(&sk->sk_callback_lock);
1647 
1648 	/* from net/core/stream.c:sk_stream_write_space */
1649 	if (sk_stream_is_writeable(sk))
1650 		xs_write_space(sk);
1651 
1652 	read_unlock_bh(&sk->sk_callback_lock);
1653 }
1654 
1655 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1656 {
1657 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1658 	struct sock *sk = transport->inet;
1659 
1660 	if (transport->rcvsize) {
1661 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1662 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1663 	}
1664 	if (transport->sndsize) {
1665 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1666 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1667 		sk->sk_write_space(sk);
1668 	}
1669 }
1670 
1671 /**
1672  * xs_udp_set_buffer_size - set send and receive limits
1673  * @xprt: generic transport
1674  * @sndsize: requested size of send buffer, in bytes
1675  * @rcvsize: requested size of receive buffer, in bytes
1676  *
1677  * Set socket send and receive buffer size limits.
1678  */
1679 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1680 {
1681 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1682 
1683 	transport->sndsize = 0;
1684 	if (sndsize)
1685 		transport->sndsize = sndsize + 1024;
1686 	transport->rcvsize = 0;
1687 	if (rcvsize)
1688 		transport->rcvsize = rcvsize + 1024;
1689 
1690 	xs_udp_do_set_buffer_size(xprt);
1691 }
1692 
1693 /**
1694  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1695  * @task: task that timed out
1696  *
1697  * Adjust the congestion window after a retransmit timeout has occurred.
1698  */
1699 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1700 {
1701 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1702 }
1703 
1704 static unsigned short xs_get_random_port(void)
1705 {
1706 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1707 	unsigned short rand = (unsigned short) prandom_u32() % range;
1708 	return rand + xprt_min_resvport;
1709 }
1710 
1711 /**
1712  * xs_set_port - reset the port number in the remote endpoint address
1713  * @xprt: generic transport
1714  * @port: new port number
1715  *
1716  */
1717 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1718 {
1719 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1720 
1721 	rpc_set_port(xs_addr(xprt), port);
1722 	xs_update_peer_port(xprt);
1723 }
1724 
1725 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1726 {
1727 	unsigned short port = transport->srcport;
1728 
1729 	if (port == 0 && transport->xprt.resvport)
1730 		port = xs_get_random_port();
1731 	return port;
1732 }
1733 
1734 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1735 {
1736 	if (transport->srcport != 0)
1737 		transport->srcport = 0;
1738 	if (!transport->xprt.resvport)
1739 		return 0;
1740 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1741 		return xprt_max_resvport;
1742 	return --port;
1743 }
1744 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1745 {
1746 	struct sockaddr_storage myaddr;
1747 	int err, nloop = 0;
1748 	unsigned short port = xs_get_srcport(transport);
1749 	unsigned short last;
1750 
1751 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1752 	do {
1753 		rpc_set_port((struct sockaddr *)&myaddr, port);
1754 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1755 				transport->xprt.addrlen);
1756 		if (port == 0)
1757 			break;
1758 		if (err == 0) {
1759 			transport->srcport = port;
1760 			break;
1761 		}
1762 		last = port;
1763 		port = xs_next_srcport(transport, port);
1764 		if (port > last)
1765 			nloop++;
1766 	} while (err == -EADDRINUSE && nloop != 2);
1767 
1768 	if (myaddr.ss_family == AF_INET)
1769 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1770 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1771 				port, err ? "failed" : "ok", err);
1772 	else
1773 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1774 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1775 				port, err ? "failed" : "ok", err);
1776 	return err;
1777 }
1778 
1779 /*
1780  * We don't support autobind on AF_LOCAL sockets
1781  */
1782 static void xs_local_rpcbind(struct rpc_task *task)
1783 {
1784 	rcu_read_lock();
1785 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1786 	rcu_read_unlock();
1787 }
1788 
1789 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1790 {
1791 }
1792 
1793 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1794 static struct lock_class_key xs_key[2];
1795 static struct lock_class_key xs_slock_key[2];
1796 
1797 static inline void xs_reclassify_socketu(struct socket *sock)
1798 {
1799 	struct sock *sk = sock->sk;
1800 
1801 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1802 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1803 }
1804 
1805 static inline void xs_reclassify_socket4(struct socket *sock)
1806 {
1807 	struct sock *sk = sock->sk;
1808 
1809 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1810 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1811 }
1812 
1813 static inline void xs_reclassify_socket6(struct socket *sock)
1814 {
1815 	struct sock *sk = sock->sk;
1816 
1817 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1818 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1819 }
1820 
1821 static inline void xs_reclassify_socket(int family, struct socket *sock)
1822 {
1823 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1824 	if (sock_owned_by_user(sock->sk))
1825 		return;
1826 
1827 	switch (family) {
1828 	case AF_LOCAL:
1829 		xs_reclassify_socketu(sock);
1830 		break;
1831 	case AF_INET:
1832 		xs_reclassify_socket4(sock);
1833 		break;
1834 	case AF_INET6:
1835 		xs_reclassify_socket6(sock);
1836 		break;
1837 	}
1838 }
1839 #else
1840 static inline void xs_reclassify_socketu(struct socket *sock)
1841 {
1842 }
1843 
1844 static inline void xs_reclassify_socket4(struct socket *sock)
1845 {
1846 }
1847 
1848 static inline void xs_reclassify_socket6(struct socket *sock)
1849 {
1850 }
1851 
1852 static inline void xs_reclassify_socket(int family, struct socket *sock)
1853 {
1854 }
1855 #endif
1856 
1857 static void xs_dummy_setup_socket(struct work_struct *work)
1858 {
1859 }
1860 
1861 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1862 		struct sock_xprt *transport, int family, int type, int protocol)
1863 {
1864 	struct socket *sock;
1865 	int err;
1866 
1867 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1868 	if (err < 0) {
1869 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1870 				protocol, -err);
1871 		goto out;
1872 	}
1873 	xs_reclassify_socket(family, sock);
1874 
1875 	err = xs_bind(transport, sock);
1876 	if (err) {
1877 		sock_release(sock);
1878 		goto out;
1879 	}
1880 
1881 	return sock;
1882 out:
1883 	return ERR_PTR(err);
1884 }
1885 
1886 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1887 				      struct socket *sock)
1888 {
1889 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1890 									xprt);
1891 
1892 	if (!transport->inet) {
1893 		struct sock *sk = sock->sk;
1894 
1895 		write_lock_bh(&sk->sk_callback_lock);
1896 
1897 		xs_save_old_callbacks(transport, sk);
1898 
1899 		sk->sk_user_data = xprt;
1900 		sk->sk_data_ready = xs_local_data_ready;
1901 		sk->sk_write_space = xs_udp_write_space;
1902 		sk->sk_error_report = xs_error_report;
1903 		sk->sk_allocation = GFP_ATOMIC;
1904 
1905 		xprt_clear_connected(xprt);
1906 
1907 		/* Reset to new socket */
1908 		transport->sock = sock;
1909 		transport->inet = sk;
1910 
1911 		write_unlock_bh(&sk->sk_callback_lock);
1912 	}
1913 
1914 	/* Tell the socket layer to start connecting... */
1915 	xprt->stat.connect_count++;
1916 	xprt->stat.connect_start = jiffies;
1917 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1918 }
1919 
1920 /**
1921  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1922  * @xprt: RPC transport to connect
1923  * @transport: socket transport to connect
1924  * @create_sock: function to create a socket of the correct type
1925  */
1926 static int xs_local_setup_socket(struct sock_xprt *transport)
1927 {
1928 	struct rpc_xprt *xprt = &transport->xprt;
1929 	struct socket *sock;
1930 	int status = -EIO;
1931 
1932 	current->flags |= PF_FSTRANS;
1933 
1934 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1935 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1936 					SOCK_STREAM, 0, &sock, 1);
1937 	if (status < 0) {
1938 		dprintk("RPC:       can't create AF_LOCAL "
1939 			"transport socket (%d).\n", -status);
1940 		goto out;
1941 	}
1942 	xs_reclassify_socketu(sock);
1943 
1944 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1945 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1946 
1947 	status = xs_local_finish_connecting(xprt, sock);
1948 	trace_rpc_socket_connect(xprt, sock, status);
1949 	switch (status) {
1950 	case 0:
1951 		dprintk("RPC:       xprt %p connected to %s\n",
1952 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1953 		xprt_set_connected(xprt);
1954 		break;
1955 	case -ENOENT:
1956 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1957 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1958 		break;
1959 	case -ECONNREFUSED:
1960 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1961 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1962 		break;
1963 	default:
1964 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1965 				__func__, -status,
1966 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1967 	}
1968 
1969 out:
1970 	xprt_clear_connecting(xprt);
1971 	xprt_wake_pending_tasks(xprt, status);
1972 	current->flags &= ~PF_FSTRANS;
1973 	return status;
1974 }
1975 
1976 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1977 {
1978 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1979 	int ret;
1980 
1981 	 if (RPC_IS_ASYNC(task)) {
1982 		/*
1983 		 * We want the AF_LOCAL connect to be resolved in the
1984 		 * filesystem namespace of the process making the rpc
1985 		 * call.  Thus we connect synchronously.
1986 		 *
1987 		 * If we want to support asynchronous AF_LOCAL calls,
1988 		 * we'll need to figure out how to pass a namespace to
1989 		 * connect.
1990 		 */
1991 		rpc_exit(task, -ENOTCONN);
1992 		return;
1993 	}
1994 	ret = xs_local_setup_socket(transport);
1995 	if (ret && !RPC_IS_SOFTCONN(task))
1996 		msleep_interruptible(15000);
1997 }
1998 
1999 #ifdef CONFIG_SUNRPC_SWAP
2000 static void xs_set_memalloc(struct rpc_xprt *xprt)
2001 {
2002 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2003 			xprt);
2004 
2005 	if (xprt->swapper)
2006 		sk_set_memalloc(transport->inet);
2007 }
2008 
2009 /**
2010  * xs_swapper - Tag this transport as being used for swap.
2011  * @xprt: transport to tag
2012  * @enable: enable/disable
2013  *
2014  */
2015 int xs_swapper(struct rpc_xprt *xprt, int enable)
2016 {
2017 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2018 			xprt);
2019 	int err = 0;
2020 
2021 	if (enable) {
2022 		xprt->swapper++;
2023 		xs_set_memalloc(xprt);
2024 	} else if (xprt->swapper) {
2025 		xprt->swapper--;
2026 		sk_clear_memalloc(transport->inet);
2027 	}
2028 
2029 	return err;
2030 }
2031 EXPORT_SYMBOL_GPL(xs_swapper);
2032 #else
2033 static void xs_set_memalloc(struct rpc_xprt *xprt)
2034 {
2035 }
2036 #endif
2037 
2038 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2039 {
2040 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2041 
2042 	if (!transport->inet) {
2043 		struct sock *sk = sock->sk;
2044 
2045 		write_lock_bh(&sk->sk_callback_lock);
2046 
2047 		xs_save_old_callbacks(transport, sk);
2048 
2049 		sk->sk_user_data = xprt;
2050 		sk->sk_data_ready = xs_udp_data_ready;
2051 		sk->sk_write_space = xs_udp_write_space;
2052 		sk->sk_no_check = UDP_CSUM_NORCV;
2053 		sk->sk_allocation = GFP_ATOMIC;
2054 
2055 		xprt_set_connected(xprt);
2056 
2057 		/* Reset to new socket */
2058 		transport->sock = sock;
2059 		transport->inet = sk;
2060 
2061 		xs_set_memalloc(xprt);
2062 
2063 		write_unlock_bh(&sk->sk_callback_lock);
2064 	}
2065 	xs_udp_do_set_buffer_size(xprt);
2066 }
2067 
2068 static void xs_udp_setup_socket(struct work_struct *work)
2069 {
2070 	struct sock_xprt *transport =
2071 		container_of(work, struct sock_xprt, connect_worker.work);
2072 	struct rpc_xprt *xprt = &transport->xprt;
2073 	struct socket *sock = transport->sock;
2074 	int status = -EIO;
2075 
2076 	current->flags |= PF_FSTRANS;
2077 
2078 	/* Start by resetting any existing state */
2079 	xs_reset_transport(transport);
2080 	sock = xs_create_sock(xprt, transport,
2081 			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2082 	if (IS_ERR(sock))
2083 		goto out;
2084 
2085 	dprintk("RPC:       worker connecting xprt %p via %s to "
2086 				"%s (port %s)\n", xprt,
2087 			xprt->address_strings[RPC_DISPLAY_PROTO],
2088 			xprt->address_strings[RPC_DISPLAY_ADDR],
2089 			xprt->address_strings[RPC_DISPLAY_PORT]);
2090 
2091 	xs_udp_finish_connecting(xprt, sock);
2092 	trace_rpc_socket_connect(xprt, sock, 0);
2093 	status = 0;
2094 out:
2095 	xprt_clear_connecting(xprt);
2096 	xprt_wake_pending_tasks(xprt, status);
2097 	current->flags &= ~PF_FSTRANS;
2098 }
2099 
2100 /*
2101  * We need to preserve the port number so the reply cache on the server can
2102  * find our cached RPC replies when we get around to reconnecting.
2103  */
2104 static void xs_abort_connection(struct sock_xprt *transport)
2105 {
2106 	int result;
2107 	struct sockaddr any;
2108 
2109 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2110 
2111 	/*
2112 	 * Disconnect the transport socket by doing a connect operation
2113 	 * with AF_UNSPEC.  This should return immediately...
2114 	 */
2115 	memset(&any, 0, sizeof(any));
2116 	any.sa_family = AF_UNSPEC;
2117 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2118 	trace_rpc_socket_reset_connection(&transport->xprt,
2119 			transport->sock, result);
2120 	if (!result)
2121 		xs_sock_reset_connection_flags(&transport->xprt);
2122 	dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2123 }
2124 
2125 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2126 {
2127 	unsigned int state = transport->inet->sk_state;
2128 
2129 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2130 		/* we don't need to abort the connection if the socket
2131 		 * hasn't undergone a shutdown
2132 		 */
2133 		if (transport->inet->sk_shutdown == 0)
2134 			return;
2135 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2136 				__func__, transport->inet->sk_shutdown);
2137 	}
2138 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2139 		/* we don't need to abort the connection if the socket
2140 		 * hasn't undergone a shutdown
2141 		 */
2142 		if (transport->inet->sk_shutdown == 0)
2143 			return;
2144 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2145 				"sk_shutdown set to %d\n",
2146 				__func__, transport->inet->sk_shutdown);
2147 	}
2148 	xs_abort_connection(transport);
2149 }
2150 
2151 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2152 {
2153 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2154 	int ret = -ENOTCONN;
2155 
2156 	if (!transport->inet) {
2157 		struct sock *sk = sock->sk;
2158 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2159 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2160 		unsigned int opt_on = 1;
2161 
2162 		/* TCP Keepalive options */
2163 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2164 				(char *)&opt_on, sizeof(opt_on));
2165 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2166 				(char *)&keepidle, sizeof(keepidle));
2167 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2168 				(char *)&keepidle, sizeof(keepidle));
2169 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2170 				(char *)&keepcnt, sizeof(keepcnt));
2171 
2172 		write_lock_bh(&sk->sk_callback_lock);
2173 
2174 		xs_save_old_callbacks(transport, sk);
2175 
2176 		sk->sk_user_data = xprt;
2177 		sk->sk_data_ready = xs_tcp_data_ready;
2178 		sk->sk_state_change = xs_tcp_state_change;
2179 		sk->sk_write_space = xs_tcp_write_space;
2180 		sk->sk_error_report = xs_error_report;
2181 		sk->sk_allocation = GFP_ATOMIC;
2182 
2183 		/* socket options */
2184 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2185 		sock_reset_flag(sk, SOCK_LINGER);
2186 		tcp_sk(sk)->linger2 = 0;
2187 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2188 
2189 		xprt_clear_connected(xprt);
2190 
2191 		/* Reset to new socket */
2192 		transport->sock = sock;
2193 		transport->inet = sk;
2194 
2195 		write_unlock_bh(&sk->sk_callback_lock);
2196 	}
2197 
2198 	if (!xprt_bound(xprt))
2199 		goto out;
2200 
2201 	xs_set_memalloc(xprt);
2202 
2203 	/* Tell the socket layer to start connecting... */
2204 	xprt->stat.connect_count++;
2205 	xprt->stat.connect_start = jiffies;
2206 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2207 	switch (ret) {
2208 	case 0:
2209 	case -EINPROGRESS:
2210 		/* SYN_SENT! */
2211 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2212 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2213 	}
2214 out:
2215 	return ret;
2216 }
2217 
2218 /**
2219  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2220  * @xprt: RPC transport to connect
2221  * @transport: socket transport to connect
2222  * @create_sock: function to create a socket of the correct type
2223  *
2224  * Invoked by a work queue tasklet.
2225  */
2226 static void xs_tcp_setup_socket(struct work_struct *work)
2227 {
2228 	struct sock_xprt *transport =
2229 		container_of(work, struct sock_xprt, connect_worker.work);
2230 	struct socket *sock = transport->sock;
2231 	struct rpc_xprt *xprt = &transport->xprt;
2232 	int status = -EIO;
2233 
2234 	current->flags |= PF_FSTRANS;
2235 
2236 	if (!sock) {
2237 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2238 		sock = xs_create_sock(xprt, transport,
2239 				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2240 		if (IS_ERR(sock)) {
2241 			status = PTR_ERR(sock);
2242 			goto out;
2243 		}
2244 	} else {
2245 		int abort_and_exit;
2246 
2247 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2248 				&xprt->state);
2249 		/* "close" the socket, preserving the local port */
2250 		xs_tcp_reuse_connection(transport);
2251 
2252 		if (abort_and_exit)
2253 			goto out_eagain;
2254 	}
2255 
2256 	dprintk("RPC:       worker connecting xprt %p via %s to "
2257 				"%s (port %s)\n", xprt,
2258 			xprt->address_strings[RPC_DISPLAY_PROTO],
2259 			xprt->address_strings[RPC_DISPLAY_ADDR],
2260 			xprt->address_strings[RPC_DISPLAY_PORT]);
2261 
2262 	status = xs_tcp_finish_connecting(xprt, sock);
2263 	trace_rpc_socket_connect(xprt, sock, status);
2264 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2265 			xprt, -status, xprt_connected(xprt),
2266 			sock->sk->sk_state);
2267 	switch (status) {
2268 	default:
2269 		printk("%s: connect returned unhandled error %d\n",
2270 			__func__, status);
2271 	case -EADDRNOTAVAIL:
2272 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2273 		 * and retry
2274 		 */
2275 		xs_tcp_force_close(xprt);
2276 		break;
2277 	case 0:
2278 	case -EINPROGRESS:
2279 	case -EALREADY:
2280 		xprt_clear_connecting(xprt);
2281 		current->flags &= ~PF_FSTRANS;
2282 		return;
2283 	case -EINVAL:
2284 		/* Happens, for instance, if the user specified a link
2285 		 * local IPv6 address without a scope-id.
2286 		 */
2287 	case -ECONNREFUSED:
2288 	case -ECONNRESET:
2289 	case -ENETUNREACH:
2290 		/* retry with existing socket, after a delay */
2291 		goto out;
2292 	}
2293 out_eagain:
2294 	status = -EAGAIN;
2295 out:
2296 	xprt_clear_connecting(xprt);
2297 	xprt_wake_pending_tasks(xprt, status);
2298 	current->flags &= ~PF_FSTRANS;
2299 }
2300 
2301 /**
2302  * xs_connect - connect a socket to a remote endpoint
2303  * @xprt: pointer to transport structure
2304  * @task: address of RPC task that manages state of connect request
2305  *
2306  * TCP: If the remote end dropped the connection, delay reconnecting.
2307  *
2308  * UDP socket connects are synchronous, but we use a work queue anyway
2309  * to guarantee that even unprivileged user processes can set up a
2310  * socket on a privileged port.
2311  *
2312  * If a UDP socket connect fails, the delay behavior here prevents
2313  * retry floods (hard mounts).
2314  */
2315 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2316 {
2317 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2318 
2319 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2320 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2321 				"seconds\n",
2322 				xprt, xprt->reestablish_timeout / HZ);
2323 		queue_delayed_work(rpciod_workqueue,
2324 				   &transport->connect_worker,
2325 				   xprt->reestablish_timeout);
2326 		xprt->reestablish_timeout <<= 1;
2327 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2328 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2329 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2330 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2331 	} else {
2332 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2333 		queue_delayed_work(rpciod_workqueue,
2334 				   &transport->connect_worker, 0);
2335 	}
2336 }
2337 
2338 /**
2339  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2340  * @xprt: rpc_xprt struct containing statistics
2341  * @seq: output file
2342  *
2343  */
2344 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2345 {
2346 	long idle_time = 0;
2347 
2348 	if (xprt_connected(xprt))
2349 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2350 
2351 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2352 			"%llu %llu %lu %llu %llu\n",
2353 			xprt->stat.bind_count,
2354 			xprt->stat.connect_count,
2355 			xprt->stat.connect_time,
2356 			idle_time,
2357 			xprt->stat.sends,
2358 			xprt->stat.recvs,
2359 			xprt->stat.bad_xids,
2360 			xprt->stat.req_u,
2361 			xprt->stat.bklog_u,
2362 			xprt->stat.max_slots,
2363 			xprt->stat.sending_u,
2364 			xprt->stat.pending_u);
2365 }
2366 
2367 /**
2368  * xs_udp_print_stats - display UDP socket-specifc stats
2369  * @xprt: rpc_xprt struct containing statistics
2370  * @seq: output file
2371  *
2372  */
2373 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2374 {
2375 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2376 
2377 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2378 			"%lu %llu %llu\n",
2379 			transport->srcport,
2380 			xprt->stat.bind_count,
2381 			xprt->stat.sends,
2382 			xprt->stat.recvs,
2383 			xprt->stat.bad_xids,
2384 			xprt->stat.req_u,
2385 			xprt->stat.bklog_u,
2386 			xprt->stat.max_slots,
2387 			xprt->stat.sending_u,
2388 			xprt->stat.pending_u);
2389 }
2390 
2391 /**
2392  * xs_tcp_print_stats - display TCP socket-specifc stats
2393  * @xprt: rpc_xprt struct containing statistics
2394  * @seq: output file
2395  *
2396  */
2397 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2398 {
2399 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2400 	long idle_time = 0;
2401 
2402 	if (xprt_connected(xprt))
2403 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2404 
2405 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2406 			"%llu %llu %lu %llu %llu\n",
2407 			transport->srcport,
2408 			xprt->stat.bind_count,
2409 			xprt->stat.connect_count,
2410 			xprt->stat.connect_time,
2411 			idle_time,
2412 			xprt->stat.sends,
2413 			xprt->stat.recvs,
2414 			xprt->stat.bad_xids,
2415 			xprt->stat.req_u,
2416 			xprt->stat.bklog_u,
2417 			xprt->stat.max_slots,
2418 			xprt->stat.sending_u,
2419 			xprt->stat.pending_u);
2420 }
2421 
2422 /*
2423  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2424  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2425  * to use the server side send routines.
2426  */
2427 static void *bc_malloc(struct rpc_task *task, size_t size)
2428 {
2429 	struct page *page;
2430 	struct rpc_buffer *buf;
2431 
2432 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2433 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2434 		return NULL;
2435 
2436 	page = alloc_page(GFP_KERNEL);
2437 	if (!page)
2438 		return NULL;
2439 
2440 	buf = page_address(page);
2441 	buf->len = PAGE_SIZE;
2442 
2443 	return buf->data;
2444 }
2445 
2446 /*
2447  * Free the space allocated in the bc_alloc routine
2448  */
2449 static void bc_free(void *buffer)
2450 {
2451 	struct rpc_buffer *buf;
2452 
2453 	if (!buffer)
2454 		return;
2455 
2456 	buf = container_of(buffer, struct rpc_buffer, data);
2457 	free_page((unsigned long)buf);
2458 }
2459 
2460 /*
2461  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2462  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2463  */
2464 static int bc_sendto(struct rpc_rqst *req)
2465 {
2466 	int len;
2467 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2468 	struct rpc_xprt *xprt = req->rq_xprt;
2469 	struct sock_xprt *transport =
2470 				container_of(xprt, struct sock_xprt, xprt);
2471 	struct socket *sock = transport->sock;
2472 	unsigned long headoff;
2473 	unsigned long tailoff;
2474 
2475 	xs_encode_stream_record_marker(xbufp);
2476 
2477 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2478 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2479 	len = svc_send_common(sock, xbufp,
2480 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2481 			      xbufp->tail[0].iov_base, tailoff);
2482 
2483 	if (len != xbufp->len) {
2484 		printk(KERN_NOTICE "Error sending entire callback!\n");
2485 		len = -EAGAIN;
2486 	}
2487 
2488 	return len;
2489 }
2490 
2491 /*
2492  * The send routine. Borrows from svc_send
2493  */
2494 static int bc_send_request(struct rpc_task *task)
2495 {
2496 	struct rpc_rqst *req = task->tk_rqstp;
2497 	struct svc_xprt	*xprt;
2498 	u32                     len;
2499 
2500 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2501 	/*
2502 	 * Get the server socket associated with this callback xprt
2503 	 */
2504 	xprt = req->rq_xprt->bc_xprt;
2505 
2506 	/*
2507 	 * Grab the mutex to serialize data as the connection is shared
2508 	 * with the fore channel
2509 	 */
2510 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2511 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2512 		if (!mutex_trylock(&xprt->xpt_mutex))
2513 			return -EAGAIN;
2514 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2515 	}
2516 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2517 		len = -ENOTCONN;
2518 	else
2519 		len = bc_sendto(req);
2520 	mutex_unlock(&xprt->xpt_mutex);
2521 
2522 	if (len > 0)
2523 		len = 0;
2524 
2525 	return len;
2526 }
2527 
2528 /*
2529  * The close routine. Since this is client initiated, we do nothing
2530  */
2531 
2532 static void bc_close(struct rpc_xprt *xprt)
2533 {
2534 }
2535 
2536 /*
2537  * The xprt destroy routine. Again, because this connection is client
2538  * initiated, we do nothing
2539  */
2540 
2541 static void bc_destroy(struct rpc_xprt *xprt)
2542 {
2543 }
2544 
2545 static struct rpc_xprt_ops xs_local_ops = {
2546 	.reserve_xprt		= xprt_reserve_xprt,
2547 	.release_xprt		= xs_tcp_release_xprt,
2548 	.alloc_slot		= xprt_alloc_slot,
2549 	.rpcbind		= xs_local_rpcbind,
2550 	.set_port		= xs_local_set_port,
2551 	.connect		= xs_local_connect,
2552 	.buf_alloc		= rpc_malloc,
2553 	.buf_free		= rpc_free,
2554 	.send_request		= xs_local_send_request,
2555 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2556 	.close			= xs_close,
2557 	.destroy		= xs_destroy,
2558 	.print_stats		= xs_local_print_stats,
2559 };
2560 
2561 static struct rpc_xprt_ops xs_udp_ops = {
2562 	.set_buffer_size	= xs_udp_set_buffer_size,
2563 	.reserve_xprt		= xprt_reserve_xprt_cong,
2564 	.release_xprt		= xprt_release_xprt_cong,
2565 	.alloc_slot		= xprt_alloc_slot,
2566 	.rpcbind		= rpcb_getport_async,
2567 	.set_port		= xs_set_port,
2568 	.connect		= xs_connect,
2569 	.buf_alloc		= rpc_malloc,
2570 	.buf_free		= rpc_free,
2571 	.send_request		= xs_udp_send_request,
2572 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2573 	.timer			= xs_udp_timer,
2574 	.release_request	= xprt_release_rqst_cong,
2575 	.close			= xs_close,
2576 	.destroy		= xs_destroy,
2577 	.print_stats		= xs_udp_print_stats,
2578 };
2579 
2580 static struct rpc_xprt_ops xs_tcp_ops = {
2581 	.reserve_xprt		= xprt_reserve_xprt,
2582 	.release_xprt		= xs_tcp_release_xprt,
2583 	.alloc_slot		= xprt_lock_and_alloc_slot,
2584 	.rpcbind		= rpcb_getport_async,
2585 	.set_port		= xs_set_port,
2586 	.connect		= xs_connect,
2587 	.buf_alloc		= rpc_malloc,
2588 	.buf_free		= rpc_free,
2589 	.send_request		= xs_tcp_send_request,
2590 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2591 	.close			= xs_tcp_close,
2592 	.destroy		= xs_destroy,
2593 	.print_stats		= xs_tcp_print_stats,
2594 };
2595 
2596 /*
2597  * The rpc_xprt_ops for the server backchannel
2598  */
2599 
2600 static struct rpc_xprt_ops bc_tcp_ops = {
2601 	.reserve_xprt		= xprt_reserve_xprt,
2602 	.release_xprt		= xprt_release_xprt,
2603 	.alloc_slot		= xprt_alloc_slot,
2604 	.buf_alloc		= bc_malloc,
2605 	.buf_free		= bc_free,
2606 	.send_request		= bc_send_request,
2607 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2608 	.close			= bc_close,
2609 	.destroy		= bc_destroy,
2610 	.print_stats		= xs_tcp_print_stats,
2611 };
2612 
2613 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2614 {
2615 	static const struct sockaddr_in sin = {
2616 		.sin_family		= AF_INET,
2617 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2618 	};
2619 	static const struct sockaddr_in6 sin6 = {
2620 		.sin6_family		= AF_INET6,
2621 		.sin6_addr		= IN6ADDR_ANY_INIT,
2622 	};
2623 
2624 	switch (family) {
2625 	case AF_LOCAL:
2626 		break;
2627 	case AF_INET:
2628 		memcpy(sap, &sin, sizeof(sin));
2629 		break;
2630 	case AF_INET6:
2631 		memcpy(sap, &sin6, sizeof(sin6));
2632 		break;
2633 	default:
2634 		dprintk("RPC:       %s: Bad address family\n", __func__);
2635 		return -EAFNOSUPPORT;
2636 	}
2637 	return 0;
2638 }
2639 
2640 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2641 				      unsigned int slot_table_size,
2642 				      unsigned int max_slot_table_size)
2643 {
2644 	struct rpc_xprt *xprt;
2645 	struct sock_xprt *new;
2646 
2647 	if (args->addrlen > sizeof(xprt->addr)) {
2648 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2649 		return ERR_PTR(-EBADF);
2650 	}
2651 
2652 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2653 			max_slot_table_size);
2654 	if (xprt == NULL) {
2655 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2656 				"rpc_xprt\n");
2657 		return ERR_PTR(-ENOMEM);
2658 	}
2659 
2660 	new = container_of(xprt, struct sock_xprt, xprt);
2661 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2662 	xprt->addrlen = args->addrlen;
2663 	if (args->srcaddr)
2664 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2665 	else {
2666 		int err;
2667 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2668 					(struct sockaddr *)&new->srcaddr);
2669 		if (err != 0) {
2670 			xprt_free(xprt);
2671 			return ERR_PTR(err);
2672 		}
2673 	}
2674 
2675 	return xprt;
2676 }
2677 
2678 static const struct rpc_timeout xs_local_default_timeout = {
2679 	.to_initval = 10 * HZ,
2680 	.to_maxval = 10 * HZ,
2681 	.to_retries = 2,
2682 };
2683 
2684 /**
2685  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2686  * @args: rpc transport creation arguments
2687  *
2688  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2689  */
2690 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2691 {
2692 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2693 	struct sock_xprt *transport;
2694 	struct rpc_xprt *xprt;
2695 	struct rpc_xprt *ret;
2696 
2697 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2698 			xprt_max_tcp_slot_table_entries);
2699 	if (IS_ERR(xprt))
2700 		return xprt;
2701 	transport = container_of(xprt, struct sock_xprt, xprt);
2702 
2703 	xprt->prot = 0;
2704 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2705 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2706 
2707 	xprt->bind_timeout = XS_BIND_TO;
2708 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2709 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2710 
2711 	xprt->ops = &xs_local_ops;
2712 	xprt->timeout = &xs_local_default_timeout;
2713 
2714 	INIT_DELAYED_WORK(&transport->connect_worker,
2715 			xs_dummy_setup_socket);
2716 
2717 	switch (sun->sun_family) {
2718 	case AF_LOCAL:
2719 		if (sun->sun_path[0] != '/') {
2720 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2721 					sun->sun_path);
2722 			ret = ERR_PTR(-EINVAL);
2723 			goto out_err;
2724 		}
2725 		xprt_set_bound(xprt);
2726 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2727 		ret = ERR_PTR(xs_local_setup_socket(transport));
2728 		if (ret)
2729 			goto out_err;
2730 		break;
2731 	default:
2732 		ret = ERR_PTR(-EAFNOSUPPORT);
2733 		goto out_err;
2734 	}
2735 
2736 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2737 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2738 
2739 	if (try_module_get(THIS_MODULE))
2740 		return xprt;
2741 	ret = ERR_PTR(-EINVAL);
2742 out_err:
2743 	xprt_free(xprt);
2744 	return ret;
2745 }
2746 
2747 static const struct rpc_timeout xs_udp_default_timeout = {
2748 	.to_initval = 5 * HZ,
2749 	.to_maxval = 30 * HZ,
2750 	.to_increment = 5 * HZ,
2751 	.to_retries = 5,
2752 };
2753 
2754 /**
2755  * xs_setup_udp - Set up transport to use a UDP socket
2756  * @args: rpc transport creation arguments
2757  *
2758  */
2759 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2760 {
2761 	struct sockaddr *addr = args->dstaddr;
2762 	struct rpc_xprt *xprt;
2763 	struct sock_xprt *transport;
2764 	struct rpc_xprt *ret;
2765 
2766 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2767 			xprt_udp_slot_table_entries);
2768 	if (IS_ERR(xprt))
2769 		return xprt;
2770 	transport = container_of(xprt, struct sock_xprt, xprt);
2771 
2772 	xprt->prot = IPPROTO_UDP;
2773 	xprt->tsh_size = 0;
2774 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2775 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2776 
2777 	xprt->bind_timeout = XS_BIND_TO;
2778 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2779 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2780 
2781 	xprt->ops = &xs_udp_ops;
2782 
2783 	xprt->timeout = &xs_udp_default_timeout;
2784 
2785 	switch (addr->sa_family) {
2786 	case AF_INET:
2787 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2788 			xprt_set_bound(xprt);
2789 
2790 		INIT_DELAYED_WORK(&transport->connect_worker,
2791 					xs_udp_setup_socket);
2792 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2793 		break;
2794 	case AF_INET6:
2795 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2796 			xprt_set_bound(xprt);
2797 
2798 		INIT_DELAYED_WORK(&transport->connect_worker,
2799 					xs_udp_setup_socket);
2800 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2801 		break;
2802 	default:
2803 		ret = ERR_PTR(-EAFNOSUPPORT);
2804 		goto out_err;
2805 	}
2806 
2807 	if (xprt_bound(xprt))
2808 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2809 				xprt->address_strings[RPC_DISPLAY_ADDR],
2810 				xprt->address_strings[RPC_DISPLAY_PORT],
2811 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2812 	else
2813 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2814 				xprt->address_strings[RPC_DISPLAY_ADDR],
2815 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2816 
2817 	if (try_module_get(THIS_MODULE))
2818 		return xprt;
2819 	ret = ERR_PTR(-EINVAL);
2820 out_err:
2821 	xprt_free(xprt);
2822 	return ret;
2823 }
2824 
2825 static const struct rpc_timeout xs_tcp_default_timeout = {
2826 	.to_initval = 60 * HZ,
2827 	.to_maxval = 60 * HZ,
2828 	.to_retries = 2,
2829 };
2830 
2831 /**
2832  * xs_setup_tcp - Set up transport to use a TCP socket
2833  * @args: rpc transport creation arguments
2834  *
2835  */
2836 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2837 {
2838 	struct sockaddr *addr = args->dstaddr;
2839 	struct rpc_xprt *xprt;
2840 	struct sock_xprt *transport;
2841 	struct rpc_xprt *ret;
2842 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2843 
2844 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2845 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2846 
2847 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2848 			max_slot_table_size);
2849 	if (IS_ERR(xprt))
2850 		return xprt;
2851 	transport = container_of(xprt, struct sock_xprt, xprt);
2852 
2853 	xprt->prot = IPPROTO_TCP;
2854 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2855 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2856 
2857 	xprt->bind_timeout = XS_BIND_TO;
2858 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2859 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2860 
2861 	xprt->ops = &xs_tcp_ops;
2862 	xprt->timeout = &xs_tcp_default_timeout;
2863 
2864 	switch (addr->sa_family) {
2865 	case AF_INET:
2866 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2867 			xprt_set_bound(xprt);
2868 
2869 		INIT_DELAYED_WORK(&transport->connect_worker,
2870 					xs_tcp_setup_socket);
2871 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2872 		break;
2873 	case AF_INET6:
2874 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2875 			xprt_set_bound(xprt);
2876 
2877 		INIT_DELAYED_WORK(&transport->connect_worker,
2878 					xs_tcp_setup_socket);
2879 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2880 		break;
2881 	default:
2882 		ret = ERR_PTR(-EAFNOSUPPORT);
2883 		goto out_err;
2884 	}
2885 
2886 	if (xprt_bound(xprt))
2887 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2888 				xprt->address_strings[RPC_DISPLAY_ADDR],
2889 				xprt->address_strings[RPC_DISPLAY_PORT],
2890 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2891 	else
2892 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2893 				xprt->address_strings[RPC_DISPLAY_ADDR],
2894 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2895 
2896 
2897 	if (try_module_get(THIS_MODULE))
2898 		return xprt;
2899 	ret = ERR_PTR(-EINVAL);
2900 out_err:
2901 	xprt_free(xprt);
2902 	return ret;
2903 }
2904 
2905 /**
2906  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2907  * @args: rpc transport creation arguments
2908  *
2909  */
2910 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2911 {
2912 	struct sockaddr *addr = args->dstaddr;
2913 	struct rpc_xprt *xprt;
2914 	struct sock_xprt *transport;
2915 	struct svc_sock *bc_sock;
2916 	struct rpc_xprt *ret;
2917 
2918 	if (args->bc_xprt->xpt_bc_xprt) {
2919 		/*
2920 		 * This server connection already has a backchannel
2921 		 * transport; we can't create a new one, as we wouldn't
2922 		 * be able to match replies based on xid any more.  So,
2923 		 * reuse the already-existing one:
2924 		 */
2925 		 return args->bc_xprt->xpt_bc_xprt;
2926 	}
2927 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2928 			xprt_tcp_slot_table_entries);
2929 	if (IS_ERR(xprt))
2930 		return xprt;
2931 	transport = container_of(xprt, struct sock_xprt, xprt);
2932 
2933 	xprt->prot = IPPROTO_TCP;
2934 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2935 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2936 	xprt->timeout = &xs_tcp_default_timeout;
2937 
2938 	/* backchannel */
2939 	xprt_set_bound(xprt);
2940 	xprt->bind_timeout = 0;
2941 	xprt->reestablish_timeout = 0;
2942 	xprt->idle_timeout = 0;
2943 
2944 	xprt->ops = &bc_tcp_ops;
2945 
2946 	switch (addr->sa_family) {
2947 	case AF_INET:
2948 		xs_format_peer_addresses(xprt, "tcp",
2949 					 RPCBIND_NETID_TCP);
2950 		break;
2951 	case AF_INET6:
2952 		xs_format_peer_addresses(xprt, "tcp",
2953 				   RPCBIND_NETID_TCP6);
2954 		break;
2955 	default:
2956 		ret = ERR_PTR(-EAFNOSUPPORT);
2957 		goto out_err;
2958 	}
2959 
2960 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2961 			xprt->address_strings[RPC_DISPLAY_ADDR],
2962 			xprt->address_strings[RPC_DISPLAY_PORT],
2963 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2964 
2965 	/*
2966 	 * Once we've associated a backchannel xprt with a connection,
2967 	 * we want to keep it around as long as the connection lasts,
2968 	 * in case we need to start using it for a backchannel again;
2969 	 * this reference won't be dropped until bc_xprt is destroyed.
2970 	 */
2971 	xprt_get(xprt);
2972 	args->bc_xprt->xpt_bc_xprt = xprt;
2973 	xprt->bc_xprt = args->bc_xprt;
2974 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2975 	transport->sock = bc_sock->sk_sock;
2976 	transport->inet = bc_sock->sk_sk;
2977 
2978 	/*
2979 	 * Since we don't want connections for the backchannel, we set
2980 	 * the xprt status to connected
2981 	 */
2982 	xprt_set_connected(xprt);
2983 
2984 
2985 	if (try_module_get(THIS_MODULE))
2986 		return xprt;
2987 	xprt_put(xprt);
2988 	ret = ERR_PTR(-EINVAL);
2989 out_err:
2990 	xprt_free(xprt);
2991 	return ret;
2992 }
2993 
2994 static struct xprt_class	xs_local_transport = {
2995 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2996 	.name		= "named UNIX socket",
2997 	.owner		= THIS_MODULE,
2998 	.ident		= XPRT_TRANSPORT_LOCAL,
2999 	.setup		= xs_setup_local,
3000 };
3001 
3002 static struct xprt_class	xs_udp_transport = {
3003 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3004 	.name		= "udp",
3005 	.owner		= THIS_MODULE,
3006 	.ident		= XPRT_TRANSPORT_UDP,
3007 	.setup		= xs_setup_udp,
3008 };
3009 
3010 static struct xprt_class	xs_tcp_transport = {
3011 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3012 	.name		= "tcp",
3013 	.owner		= THIS_MODULE,
3014 	.ident		= XPRT_TRANSPORT_TCP,
3015 	.setup		= xs_setup_tcp,
3016 };
3017 
3018 static struct xprt_class	xs_bc_tcp_transport = {
3019 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3020 	.name		= "tcp NFSv4.1 backchannel",
3021 	.owner		= THIS_MODULE,
3022 	.ident		= XPRT_TRANSPORT_BC_TCP,
3023 	.setup		= xs_setup_bc_tcp,
3024 };
3025 
3026 /**
3027  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3028  *
3029  */
3030 int init_socket_xprt(void)
3031 {
3032 #ifdef RPC_DEBUG
3033 	if (!sunrpc_table_header)
3034 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3035 #endif
3036 
3037 	xprt_register_transport(&xs_local_transport);
3038 	xprt_register_transport(&xs_udp_transport);
3039 	xprt_register_transport(&xs_tcp_transport);
3040 	xprt_register_transport(&xs_bc_tcp_transport);
3041 
3042 	return 0;
3043 }
3044 
3045 /**
3046  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3047  *
3048  */
3049 void cleanup_socket_xprt(void)
3050 {
3051 #ifdef RPC_DEBUG
3052 	if (sunrpc_table_header) {
3053 		unregister_sysctl_table(sunrpc_table_header);
3054 		sunrpc_table_header = NULL;
3055 	}
3056 #endif
3057 
3058 	xprt_unregister_transport(&xs_local_transport);
3059 	xprt_unregister_transport(&xs_udp_transport);
3060 	xprt_unregister_transport(&xs_tcp_transport);
3061 	xprt_unregister_transport(&xs_bc_tcp_transport);
3062 }
3063 
3064 static int param_set_uint_minmax(const char *val,
3065 		const struct kernel_param *kp,
3066 		unsigned int min, unsigned int max)
3067 {
3068 	unsigned long num;
3069 	int ret;
3070 
3071 	if (!val)
3072 		return -EINVAL;
3073 	ret = strict_strtoul(val, 0, &num);
3074 	if (ret == -EINVAL || num < min || num > max)
3075 		return -EINVAL;
3076 	*((unsigned int *)kp->arg) = num;
3077 	return 0;
3078 }
3079 
3080 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3081 {
3082 	return param_set_uint_minmax(val, kp,
3083 			RPC_MIN_RESVPORT,
3084 			RPC_MAX_RESVPORT);
3085 }
3086 
3087 static struct kernel_param_ops param_ops_portnr = {
3088 	.set = param_set_portnr,
3089 	.get = param_get_uint,
3090 };
3091 
3092 #define param_check_portnr(name, p) \
3093 	__param_check(name, p, unsigned int);
3094 
3095 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3096 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3097 
3098 static int param_set_slot_table_size(const char *val,
3099 				     const struct kernel_param *kp)
3100 {
3101 	return param_set_uint_minmax(val, kp,
3102 			RPC_MIN_SLOT_TABLE,
3103 			RPC_MAX_SLOT_TABLE);
3104 }
3105 
3106 static struct kernel_param_ops param_ops_slot_table_size = {
3107 	.set = param_set_slot_table_size,
3108 	.get = param_get_uint,
3109 };
3110 
3111 #define param_check_slot_table_size(name, p) \
3112 	__param_check(name, p, unsigned int);
3113 
3114 static int param_set_max_slot_table_size(const char *val,
3115 				     const struct kernel_param *kp)
3116 {
3117 	return param_set_uint_minmax(val, kp,
3118 			RPC_MIN_SLOT_TABLE,
3119 			RPC_MAX_SLOT_TABLE_LIMIT);
3120 }
3121 
3122 static struct kernel_param_ops param_ops_max_slot_table_size = {
3123 	.set = param_set_max_slot_table_size,
3124 	.get = param_get_uint,
3125 };
3126 
3127 #define param_check_max_slot_table_size(name, p) \
3128 	__param_check(name, p, unsigned int);
3129 
3130 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3131 		   slot_table_size, 0644);
3132 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3133 		   max_slot_table_size, 0644);
3134 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3135 		   slot_table_size, 0644);
3136 
3137