Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
[linux-2.6] / net / sunrpc / svcsock.c
1 /*
2  * linux/net/sunrpc/svcsock.c
3  *
4  * These are the RPC server socket internals.
5  *
6  * The server scheduling algorithm does not always distribute the load
7  * evenly when servicing a single client. May need to modify the
8  * svc_sock_enqueue procedure...
9  *
10  * TCP support is largely untested and may be a little slow. The problem
11  * is that we currently do two separate recvfrom's, one for the 4-byte
12  * record length, and the second for the actual record. This could possibly
13  * be improved by always reading a minimum size of around 100 bytes and
14  * tucking any superfluous bytes away in a temporary store. Still, that
15  * leaves write requests out in the rain. An alternative may be to peek at
16  * the first skb in the queue, and if it matches the next TCP sequence
17  * number, to extract the record marker. Yuck.
18  *
19  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
20  */
21
22 #include <linux/sched.h>
23 #include <linux/errno.h>
24 #include <linux/fcntl.h>
25 #include <linux/net.h>
26 #include <linux/in.h>
27 #include <linux/inet.h>
28 #include <linux/udp.h>
29 #include <linux/tcp.h>
30 #include <linux/unistd.h>
31 #include <linux/slab.h>
32 #include <linux/netdevice.h>
33 #include <linux/skbuff.h>
34 #include <linux/file.h>
35 #include <linux/freezer.h>
36 #include <net/sock.h>
37 #include <net/checksum.h>
38 #include <net/ip.h>
39 #include <net/ipv6.h>
40 #include <net/tcp_states.h>
41 #include <asm/uaccess.h>
42 #include <asm/ioctls.h>
43
44 #include <linux/sunrpc/types.h>
45 #include <linux/sunrpc/clnt.h>
46 #include <linux/sunrpc/xdr.h>
47 #include <linux/sunrpc/svcsock.h>
48 #include <linux/sunrpc/stats.h>
49
50 /* SMP locking strategy:
51  *
52  *      svc_pool->sp_lock protects most of the fields of that pool.
53  *      svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
54  *      when both need to be taken (rare), svc_serv->sv_lock is first.
55  *      BKL protects svc_serv->sv_nrthread.
56  *      svc_sock->sk_defer_lock protects the svc_sock->sk_deferred list
57  *      svc_sock->sk_flags.SK_BUSY prevents a svc_sock being enqueued multiply.
58  *
59  *      Some flags can be set to certain values at any time
60  *      providing that certain rules are followed:
61  *
62  *      SK_CONN, SK_DATA, can be set or cleared at any time.
63  *              after a set, svc_sock_enqueue must be called.
64  *              after a clear, the socket must be read/accepted
65  *               if this succeeds, it must be set again.
66  *      SK_CLOSE can set at any time. It is never cleared.
67  *      sk_inuse contains a bias of '1' until SK_DEAD is set.
68  *             so when sk_inuse hits zero, we know the socket is dead
69  *             and no-one is using it.
70  *      SK_DEAD can only be set while SK_BUSY is held which ensures
71  *             no other thread will be using the socket or will try to
72  *             set SK_DEAD.
73  *
74  */
75
76 #define RPCDBG_FACILITY RPCDBG_SVCSOCK
77
78
79 static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
80                                          int *errp, int flags);
81 static void             svc_delete_socket(struct svc_sock *svsk);
82 static void             svc_udp_data_ready(struct sock *, int);
83 static int              svc_udp_recvfrom(struct svc_rqst *);
84 static int              svc_udp_sendto(struct svc_rqst *);
85
86 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
87 static int svc_deferred_recv(struct svc_rqst *rqstp);
88 static struct cache_deferred_req *svc_defer(struct cache_req *req);
89
90 /* apparently the "standard" is that clients close
91  * idle connections after 5 minutes, servers after
92  * 6 minutes
93  *   http://www.connectathon.org/talks96/nfstcp.pdf
94  */
95 static int svc_conn_age_period = 6*60;
96
97 #ifdef CONFIG_DEBUG_LOCK_ALLOC
98 static struct lock_class_key svc_key[2];
99 static struct lock_class_key svc_slock_key[2];
100
101 static inline void svc_reclassify_socket(struct socket *sock)
102 {
103         struct sock *sk = sock->sk;
104         BUG_ON(sk->sk_lock.owner != NULL);
105         switch (sk->sk_family) {
106         case AF_INET:
107                 sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
108                     &svc_slock_key[0], "sk_lock-AF_INET-NFSD", &svc_key[0]);
109                 break;
110
111         case AF_INET6:
112                 sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
113                     &svc_slock_key[1], "sk_lock-AF_INET6-NFSD", &svc_key[1]);
114                 break;
115
116         default:
117                 BUG();
118         }
119 }
120 #else
121 static inline void svc_reclassify_socket(struct socket *sock)
122 {
123 }
124 #endif
125
126 static char *__svc_print_addr(struct sockaddr *addr, char *buf, size_t len)
127 {
128         switch (addr->sa_family) {
129         case AF_INET:
130                 snprintf(buf, len, "%u.%u.%u.%u, port=%u",
131                         NIPQUAD(((struct sockaddr_in *) addr)->sin_addr),
132                         htons(((struct sockaddr_in *) addr)->sin_port));
133                 break;
134 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
135         case AF_INET6:
136                 snprintf(buf, len, "%x:%x:%x:%x:%x:%x:%x:%x, port=%u",
137                         NIP6(((struct sockaddr_in6 *) addr)->sin6_addr),
138                         htons(((struct sockaddr_in6 *) addr)->sin6_port));
139                 break;
140 #endif
141         default:
142                 snprintf(buf, len, "unknown address type: %d", addr->sa_family);
143                 break;
144         }
145         return buf;
146 }
147
148 /**
149  * svc_print_addr - Format rq_addr field for printing
150  * @rqstp: svc_rqst struct containing address to print
151  * @buf: target buffer for formatted address
152  * @len: length of target buffer
153  *
154  */
155 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
156 {
157         return __svc_print_addr(svc_addr(rqstp), buf, len);
158 }
159 EXPORT_SYMBOL_GPL(svc_print_addr);
160
161 /*
162  * Queue up an idle server thread.  Must have pool->sp_lock held.
163  * Note: this is really a stack rather than a queue, so that we only
164  * use as many different threads as we need, and the rest don't pollute
165  * the cache.
166  */
167 static inline void
168 svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
169 {
170         list_add(&rqstp->rq_list, &pool->sp_threads);
171 }
172
173 /*
174  * Dequeue an nfsd thread.  Must have pool->sp_lock held.
175  */
176 static inline void
177 svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
178 {
179         list_del(&rqstp->rq_list);
180 }
181
182 /*
183  * Release an skbuff after use
184  */
185 static inline void
186 svc_release_skb(struct svc_rqst *rqstp)
187 {
188         struct sk_buff *skb = rqstp->rq_skbuff;
189         struct svc_deferred_req *dr = rqstp->rq_deferred;
190
191         if (skb) {
192                 rqstp->rq_skbuff = NULL;
193
194                 dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
195                 skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
196         }
197         if (dr) {
198                 rqstp->rq_deferred = NULL;
199                 kfree(dr);
200         }
201 }
202
203 /*
204  * Any space to write?
205  */
206 static inline unsigned long
207 svc_sock_wspace(struct svc_sock *svsk)
208 {
209         int wspace;
210
211         if (svsk->sk_sock->type == SOCK_STREAM)
212                 wspace = sk_stream_wspace(svsk->sk_sk);
213         else
214                 wspace = sock_wspace(svsk->sk_sk);
215
216         return wspace;
217 }
218
219 /*
220  * Queue up a socket with data pending. If there are idle nfsd
221  * processes, wake 'em up.
222  *
223  */
224 static void
225 svc_sock_enqueue(struct svc_sock *svsk)
226 {
227         struct svc_serv *serv = svsk->sk_server;
228         struct svc_pool *pool;
229         struct svc_rqst *rqstp;
230         int cpu;
231
232         if (!(svsk->sk_flags &
233               ( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)|(1<<SK_DEFERRED)) ))
234                 return;
235         if (test_bit(SK_DEAD, &svsk->sk_flags))
236                 return;
237
238         cpu = get_cpu();
239         pool = svc_pool_for_cpu(svsk->sk_server, cpu);
240         put_cpu();
241
242         spin_lock_bh(&pool->sp_lock);
243
244         if (!list_empty(&pool->sp_threads) &&
245             !list_empty(&pool->sp_sockets))
246                 printk(KERN_ERR
247                         "svc_sock_enqueue: threads and sockets both waiting??\n");
248
249         if (test_bit(SK_DEAD, &svsk->sk_flags)) {
250                 /* Don't enqueue dead sockets */
251                 dprintk("svc: socket %p is dead, not enqueued\n", svsk->sk_sk);
252                 goto out_unlock;
253         }
254
255         /* Mark socket as busy. It will remain in this state until the
256          * server has processed all pending data and put the socket back
257          * on the idle list.  We update SK_BUSY atomically because
258          * it also guards against trying to enqueue the svc_sock twice.
259          */
260         if (test_and_set_bit(SK_BUSY, &svsk->sk_flags)) {
261                 /* Don't enqueue socket while already enqueued */
262                 dprintk("svc: socket %p busy, not enqueued\n", svsk->sk_sk);
263                 goto out_unlock;
264         }
265         BUG_ON(svsk->sk_pool != NULL);
266         svsk->sk_pool = pool;
267
268         set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
269         if (((atomic_read(&svsk->sk_reserved) + serv->sv_max_mesg)*2
270              > svc_sock_wspace(svsk))
271             && !test_bit(SK_CLOSE, &svsk->sk_flags)
272             && !test_bit(SK_CONN, &svsk->sk_flags)) {
273                 /* Don't enqueue while not enough space for reply */
274                 dprintk("svc: socket %p  no space, %d*2 > %ld, not enqueued\n",
275                         svsk->sk_sk, atomic_read(&svsk->sk_reserved)+serv->sv_max_mesg,
276                         svc_sock_wspace(svsk));
277                 svsk->sk_pool = NULL;
278                 clear_bit(SK_BUSY, &svsk->sk_flags);
279                 goto out_unlock;
280         }
281         clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
282
283
284         if (!list_empty(&pool->sp_threads)) {
285                 rqstp = list_entry(pool->sp_threads.next,
286                                    struct svc_rqst,
287                                    rq_list);
288                 dprintk("svc: socket %p served by daemon %p\n",
289                         svsk->sk_sk, rqstp);
290                 svc_thread_dequeue(pool, rqstp);
291                 if (rqstp->rq_sock)
292                         printk(KERN_ERR
293                                 "svc_sock_enqueue: server %p, rq_sock=%p!\n",
294                                 rqstp, rqstp->rq_sock);
295                 rqstp->rq_sock = svsk;
296                 atomic_inc(&svsk->sk_inuse);
297                 rqstp->rq_reserved = serv->sv_max_mesg;
298                 atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
299                 BUG_ON(svsk->sk_pool != pool);
300                 wake_up(&rqstp->rq_wait);
301         } else {
302                 dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
303                 list_add_tail(&svsk->sk_ready, &pool->sp_sockets);
304                 BUG_ON(svsk->sk_pool != pool);
305         }
306
307 out_unlock:
308         spin_unlock_bh(&pool->sp_lock);
309 }
310
311 /*
312  * Dequeue the first socket.  Must be called with the pool->sp_lock held.
313  */
314 static inline struct svc_sock *
315 svc_sock_dequeue(struct svc_pool *pool)
316 {
317         struct svc_sock *svsk;
318
319         if (list_empty(&pool->sp_sockets))
320                 return NULL;
321
322         svsk = list_entry(pool->sp_sockets.next,
323                           struct svc_sock, sk_ready);
324         list_del_init(&svsk->sk_ready);
325
326         dprintk("svc: socket %p dequeued, inuse=%d\n",
327                 svsk->sk_sk, atomic_read(&svsk->sk_inuse));
328
329         return svsk;
330 }
331
332 /*
333  * Having read something from a socket, check whether it
334  * needs to be re-enqueued.
335  * Note: SK_DATA only gets cleared when a read-attempt finds
336  * no (or insufficient) data.
337  */
338 static inline void
339 svc_sock_received(struct svc_sock *svsk)
340 {
341         svsk->sk_pool = NULL;
342         clear_bit(SK_BUSY, &svsk->sk_flags);
343         svc_sock_enqueue(svsk);
344 }
345
346
347 /**
348  * svc_reserve - change the space reserved for the reply to a request.
349  * @rqstp:  The request in question
350  * @space: new max space to reserve
351  *
352  * Each request reserves some space on the output queue of the socket
353  * to make sure the reply fits.  This function reduces that reserved
354  * space to be the amount of space used already, plus @space.
355  *
356  */
357 void svc_reserve(struct svc_rqst *rqstp, int space)
358 {
359         space += rqstp->rq_res.head[0].iov_len;
360
361         if (space < rqstp->rq_reserved) {
362                 struct svc_sock *svsk = rqstp->rq_sock;
363                 atomic_sub((rqstp->rq_reserved - space), &svsk->sk_reserved);
364                 rqstp->rq_reserved = space;
365
366                 svc_sock_enqueue(svsk);
367         }
368 }
369
370 /*
371  * Release a socket after use.
372  */
373 static inline void
374 svc_sock_put(struct svc_sock *svsk)
375 {
376         if (atomic_dec_and_test(&svsk->sk_inuse)) {
377                 BUG_ON(! test_bit(SK_DEAD, &svsk->sk_flags));
378
379                 dprintk("svc: releasing dead socket\n");
380                 if (svsk->sk_sock->file)
381                         sockfd_put(svsk->sk_sock);
382                 else
383                         sock_release(svsk->sk_sock);
384                 if (svsk->sk_info_authunix != NULL)
385                         svcauth_unix_info_release(svsk->sk_info_authunix);
386                 kfree(svsk);
387         }
388 }
389
390 static void
391 svc_sock_release(struct svc_rqst *rqstp)
392 {
393         struct svc_sock *svsk = rqstp->rq_sock;
394
395         svc_release_skb(rqstp);
396
397         svc_free_res_pages(rqstp);
398         rqstp->rq_res.page_len = 0;
399         rqstp->rq_res.page_base = 0;
400
401
402         /* Reset response buffer and release
403          * the reservation.
404          * But first, check that enough space was reserved
405          * for the reply, otherwise we have a bug!
406          */
407         if ((rqstp->rq_res.len) >  rqstp->rq_reserved)
408                 printk(KERN_ERR "RPC request reserved %d but used %d\n",
409                        rqstp->rq_reserved,
410                        rqstp->rq_res.len);
411
412         rqstp->rq_res.head[0].iov_len = 0;
413         svc_reserve(rqstp, 0);
414         rqstp->rq_sock = NULL;
415
416         svc_sock_put(svsk);
417 }
418
419 /*
420  * External function to wake up a server waiting for data
421  * This really only makes sense for services like lockd
422  * which have exactly one thread anyway.
423  */
424 void
425 svc_wake_up(struct svc_serv *serv)
426 {
427         struct svc_rqst *rqstp;
428         unsigned int i;
429         struct svc_pool *pool;
430
431         for (i = 0; i < serv->sv_nrpools; i++) {
432                 pool = &serv->sv_pools[i];
433
434                 spin_lock_bh(&pool->sp_lock);
435                 if (!list_empty(&pool->sp_threads)) {
436                         rqstp = list_entry(pool->sp_threads.next,
437                                            struct svc_rqst,
438                                            rq_list);
439                         dprintk("svc: daemon %p woken up.\n", rqstp);
440                         /*
441                         svc_thread_dequeue(pool, rqstp);
442                         rqstp->rq_sock = NULL;
443                          */
444                         wake_up(&rqstp->rq_wait);
445                 }
446                 spin_unlock_bh(&pool->sp_lock);
447         }
448 }
449
450 union svc_pktinfo_u {
451         struct in_pktinfo pkti;
452 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
453         struct in6_pktinfo pkti6;
454 #endif
455 };
456
457 static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
458 {
459         switch (rqstp->rq_sock->sk_sk->sk_family) {
460         case AF_INET: {
461                         struct in_pktinfo *pki = CMSG_DATA(cmh);
462
463                         cmh->cmsg_level = SOL_IP;
464                         cmh->cmsg_type = IP_PKTINFO;
465                         pki->ipi_ifindex = 0;
466                         pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
467                         cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
468                 }
469                 break;
470 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
471         case AF_INET6: {
472                         struct in6_pktinfo *pki = CMSG_DATA(cmh);
473
474                         cmh->cmsg_level = SOL_IPV6;
475                         cmh->cmsg_type = IPV6_PKTINFO;
476                         pki->ipi6_ifindex = 0;
477                         ipv6_addr_copy(&pki->ipi6_addr,
478                                         &rqstp->rq_daddr.addr6);
479                         cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
480                 }
481                 break;
482 #endif
483         }
484         return;
485 }
486
487 /*
488  * Generic sendto routine
489  */
490 static int
491 svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
492 {
493         struct svc_sock *svsk = rqstp->rq_sock;
494         struct socket   *sock = svsk->sk_sock;
495         int             slen;
496         char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
497         struct cmsghdr *cmh = (struct cmsghdr *)buffer;
498         int             len = 0;
499         int             result;
500         int             size;
501         struct page     **ppage = xdr->pages;
502         size_t          base = xdr->page_base;
503         unsigned int    pglen = xdr->page_len;
504         unsigned int    flags = MSG_MORE;
505         char            buf[RPC_MAX_ADDRBUFLEN];
506
507         slen = xdr->len;
508
509         if (rqstp->rq_prot == IPPROTO_UDP) {
510                 struct msghdr msg = {
511                         .msg_name       = &rqstp->rq_addr,
512                         .msg_namelen    = rqstp->rq_addrlen,
513                         .msg_control    = cmh,
514                         .msg_controllen = sizeof(buffer),
515                         .msg_flags      = MSG_MORE,
516                 };
517
518                 svc_set_cmsg_data(rqstp, cmh);
519
520                 if (sock_sendmsg(sock, &msg, 0) < 0)
521                         goto out;
522         }
523
524         /* send head */
525         if (slen == xdr->head[0].iov_len)
526                 flags = 0;
527         len = kernel_sendpage(sock, rqstp->rq_respages[0], 0,
528                                   xdr->head[0].iov_len, flags);
529         if (len != xdr->head[0].iov_len)
530                 goto out;
531         slen -= xdr->head[0].iov_len;
532         if (slen == 0)
533                 goto out;
534
535         /* send page data */
536         size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
537         while (pglen > 0) {
538                 if (slen == size)
539                         flags = 0;
540                 result = kernel_sendpage(sock, *ppage, base, size, flags);
541                 if (result > 0)
542                         len += result;
543                 if (result != size)
544                         goto out;
545                 slen -= size;
546                 pglen -= size;
547                 size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
548                 base = 0;
549                 ppage++;
550         }
551         /* send tail */
552         if (xdr->tail[0].iov_len) {
553                 result = kernel_sendpage(sock, rqstp->rq_respages[0],
554                                              ((unsigned long)xdr->tail[0].iov_base)
555                                                 & (PAGE_SIZE-1),
556                                              xdr->tail[0].iov_len, 0);
557
558                 if (result > 0)
559                         len += result;
560         }
561 out:
562         dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
563                 rqstp->rq_sock, xdr->head[0].iov_base, xdr->head[0].iov_len,
564                 xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
565
566         return len;
567 }
568
569 /*
570  * Report socket names for nfsdfs
571  */
572 static int one_sock_name(char *buf, struct svc_sock *svsk)
573 {
574         int len;
575
576         switch(svsk->sk_sk->sk_family) {
577         case AF_INET:
578                 len = sprintf(buf, "ipv4 %s %u.%u.%u.%u %d\n",
579                               svsk->sk_sk->sk_protocol==IPPROTO_UDP?
580                               "udp" : "tcp",
581                               NIPQUAD(inet_sk(svsk->sk_sk)->rcv_saddr),
582                               inet_sk(svsk->sk_sk)->num);
583                 break;
584         default:
585                 len = sprintf(buf, "*unknown-%d*\n",
586                                svsk->sk_sk->sk_family);
587         }
588         return len;
589 }
590
591 int
592 svc_sock_names(char *buf, struct svc_serv *serv, char *toclose)
593 {
594         struct svc_sock *svsk, *closesk = NULL;
595         int len = 0;
596
597         if (!serv)
598                 return 0;
599         spin_lock_bh(&serv->sv_lock);
600         list_for_each_entry(svsk, &serv->sv_permsocks, sk_list) {
601                 int onelen = one_sock_name(buf+len, svsk);
602                 if (toclose && strcmp(toclose, buf+len) == 0)
603                         closesk = svsk;
604                 else
605                         len += onelen;
606         }
607         spin_unlock_bh(&serv->sv_lock);
608         if (closesk)
609                 /* Should unregister with portmap, but you cannot
610                  * unregister just one protocol...
611                  */
612                 svc_close_socket(closesk);
613         else if (toclose)
614                 return -ENOENT;
615         return len;
616 }
617 EXPORT_SYMBOL(svc_sock_names);
618
619 /*
620  * Check input queue length
621  */
622 static int
623 svc_recv_available(struct svc_sock *svsk)
624 {
625         struct socket   *sock = svsk->sk_sock;
626         int             avail, err;
627
628         err = kernel_sock_ioctl(sock, TIOCINQ, (unsigned long) &avail);
629
630         return (err >= 0)? avail : err;
631 }
632
633 /*
634  * Generic recvfrom routine.
635  */
636 static int
637 svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
638 {
639         struct svc_sock *svsk = rqstp->rq_sock;
640         struct msghdr msg = {
641                 .msg_flags      = MSG_DONTWAIT,
642         };
643         int len;
644
645         len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
646                                 msg.msg_flags);
647
648         /* sock_recvmsg doesn't fill in the name/namelen, so we must..
649          */
650         memcpy(&rqstp->rq_addr, &svsk->sk_remote, svsk->sk_remotelen);
651         rqstp->rq_addrlen = svsk->sk_remotelen;
652
653         dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
654                 svsk, iov[0].iov_base, iov[0].iov_len, len);
655
656         return len;
657 }
658
659 /*
660  * Set socket snd and rcv buffer lengths
661  */
662 static inline void
663 svc_sock_setbufsize(struct socket *sock, unsigned int snd, unsigned int rcv)
664 {
665 #if 0
666         mm_segment_t    oldfs;
667         oldfs = get_fs(); set_fs(KERNEL_DS);
668         sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
669                         (char*)&snd, sizeof(snd));
670         sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
671                         (char*)&rcv, sizeof(rcv));
672 #else
673         /* sock_setsockopt limits use to sysctl_?mem_max,
674          * which isn't acceptable.  Until that is made conditional
675          * on not having CAP_SYS_RESOURCE or similar, we go direct...
676          * DaveM said I could!
677          */
678         lock_sock(sock->sk);
679         sock->sk->sk_sndbuf = snd * 2;
680         sock->sk->sk_rcvbuf = rcv * 2;
681         sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
682         release_sock(sock->sk);
683 #endif
684 }
685 /*
686  * INET callback when data has been received on the socket.
687  */
688 static void
689 svc_udp_data_ready(struct sock *sk, int count)
690 {
691         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
692
693         if (svsk) {
694                 dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
695                         svsk, sk, count, test_bit(SK_BUSY, &svsk->sk_flags));
696                 set_bit(SK_DATA, &svsk->sk_flags);
697                 svc_sock_enqueue(svsk);
698         }
699         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
700                 wake_up_interruptible(sk->sk_sleep);
701 }
702
703 /*
704  * INET callback when space is newly available on the socket.
705  */
706 static void
707 svc_write_space(struct sock *sk)
708 {
709         struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
710
711         if (svsk) {
712                 dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
713                         svsk, sk, test_bit(SK_BUSY, &svsk->sk_flags));
714                 svc_sock_enqueue(svsk);
715         }
716
717         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) {
718                 dprintk("RPC svc_write_space: someone sleeping on %p\n",
719                        svsk);
720                 wake_up_interruptible(sk->sk_sleep);
721         }
722 }
723
724 static void svc_udp_get_sender_address(struct svc_rqst *rqstp,
725                                         struct sk_buff *skb)
726 {
727         switch (rqstp->rq_sock->sk_sk->sk_family) {
728         case AF_INET: {
729                 /* this seems to come from net/ipv4/udp.c:udp_recvmsg */
730                         struct sockaddr_in *sin = svc_addr_in(rqstp);
731
732                         sin->sin_family = AF_INET;
733                         sin->sin_port = skb->h.uh->source;
734                         sin->sin_addr.s_addr = skb->nh.iph->saddr;
735                         rqstp->rq_addrlen = sizeof(struct sockaddr_in);
736                         /* Remember which interface received this request */
737                         rqstp->rq_daddr.addr.s_addr = skb->nh.iph->daddr;
738                 }
739                 break;
740 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
741         case AF_INET6: {
742                 /* this is derived from net/ipv6/udp.c:udpv6_recvmesg */
743                         struct sockaddr_in6 *sin6 = svc_addr_in6(rqstp);
744
745                         sin6->sin6_family = AF_INET6;
746                         sin6->sin6_port = skb->h.uh->source;
747                         sin6->sin6_flowinfo = 0;
748                         sin6->sin6_scope_id = 0;
749                         if (ipv6_addr_type(&sin6->sin6_addr) &
750                                                         IPV6_ADDR_LINKLOCAL)
751                                 sin6->sin6_scope_id = IP6CB(skb)->iif;
752                         ipv6_addr_copy(&sin6->sin6_addr,
753                                                         &skb->nh.ipv6h->saddr);
754                         rqstp->rq_addrlen = sizeof(struct sockaddr_in);
755                         /* Remember which interface received this request */
756                         ipv6_addr_copy(&rqstp->rq_daddr.addr6,
757                                                         &skb->nh.ipv6h->saddr);
758                 }
759                 break;
760 #endif
761         }
762         return;
763 }
764
765 /*
766  * Receive a datagram from a UDP socket.
767  */
768 static int
769 svc_udp_recvfrom(struct svc_rqst *rqstp)
770 {
771         struct svc_sock *svsk = rqstp->rq_sock;
772         struct svc_serv *serv = svsk->sk_server;
773         struct sk_buff  *skb;
774         int             err, len;
775
776         if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
777             /* udp sockets need large rcvbuf as all pending
778              * requests are still in that buffer.  sndbuf must
779              * also be large enough that there is enough space
780              * for one reply per thread.  We count all threads
781              * rather than threads in a particular pool, which
782              * provides an upper bound on the number of threads
783              * which will access the socket.
784              */
785             svc_sock_setbufsize(svsk->sk_sock,
786                                 (serv->sv_nrthreads+3) * serv->sv_max_mesg,
787                                 (serv->sv_nrthreads+3) * serv->sv_max_mesg);
788
789         if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
790                 svc_sock_received(svsk);
791                 return svc_deferred_recv(rqstp);
792         }
793
794         if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
795                 svc_delete_socket(svsk);
796                 return 0;
797         }
798
799         clear_bit(SK_DATA, &svsk->sk_flags);
800         while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
801                 if (err == -EAGAIN) {
802                         svc_sock_received(svsk);
803                         return err;
804                 }
805                 /* possibly an icmp error */
806                 dprintk("svc: recvfrom returned error %d\n", -err);
807         }
808         if (skb->tstamp.off_sec == 0) {
809                 struct timeval tv;
810
811                 tv.tv_sec = xtime.tv_sec;
812                 tv.tv_usec = xtime.tv_nsec / NSEC_PER_USEC;
813                 skb_set_timestamp(skb, &tv);
814                 /* Don't enable netstamp, sunrpc doesn't
815                    need that much accuracy */
816         }
817         skb_get_timestamp(skb, &svsk->sk_sk->sk_stamp);
818         set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
819
820         /*
821          * Maybe more packets - kick another thread ASAP.
822          */
823         svc_sock_received(svsk);
824
825         len  = skb->len - sizeof(struct udphdr);
826         rqstp->rq_arg.len = len;
827
828         rqstp->rq_prot = IPPROTO_UDP;
829
830         svc_udp_get_sender_address(rqstp, skb);
831
832         if (skb_is_nonlinear(skb)) {
833                 /* we have to copy */
834                 local_bh_disable();
835                 if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
836                         local_bh_enable();
837                         /* checksum error */
838                         skb_free_datagram(svsk->sk_sk, skb);
839                         return 0;
840                 }
841                 local_bh_enable();
842                 skb_free_datagram(svsk->sk_sk, skb);
843         } else {
844                 /* we can use it in-place */
845                 rqstp->rq_arg.head[0].iov_base = skb->data + sizeof(struct udphdr);
846                 rqstp->rq_arg.head[0].iov_len = len;
847                 if (skb_checksum_complete(skb)) {
848                         skb_free_datagram(svsk->sk_sk, skb);
849                         return 0;
850                 }
851                 rqstp->rq_skbuff = skb;
852         }
853
854         rqstp->rq_arg.page_base = 0;
855         if (len <= rqstp->rq_arg.head[0].iov_len) {
856                 rqstp->rq_arg.head[0].iov_len = len;
857                 rqstp->rq_arg.page_len = 0;
858                 rqstp->rq_respages = rqstp->rq_pages+1;
859         } else {
860                 rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
861                 rqstp->rq_respages = rqstp->rq_pages + 1 +
862                         (rqstp->rq_arg.page_len + PAGE_SIZE - 1)/ PAGE_SIZE;
863         }
864
865         if (serv->sv_stats)
866                 serv->sv_stats->netudpcnt++;
867
868         return len;
869 }
870
871 static int
872 svc_udp_sendto(struct svc_rqst *rqstp)
873 {
874         int             error;
875
876         error = svc_sendto(rqstp, &rqstp->rq_res);
877         if (error == -ECONNREFUSED)
878                 /* ICMP error on earlier request. */
879                 error = svc_sendto(rqstp, &rqstp->rq_res);
880
881         return error;
882 }
883
884 static void
885 svc_udp_init(struct svc_sock *svsk)
886 {
887         svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
888         svsk->sk_sk->sk_write_space = svc_write_space;
889         svsk->sk_recvfrom = svc_udp_recvfrom;
890         svsk->sk_sendto = svc_udp_sendto;
891
892         /* initialise setting must have enough space to
893          * receive and respond to one request.
894          * svc_udp_recvfrom will re-adjust if necessary
895          */
896         svc_sock_setbufsize(svsk->sk_sock,
897                             3 * svsk->sk_server->sv_max_mesg,
898                             3 * svsk->sk_server->sv_max_mesg);
899
900         set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */
901         set_bit(SK_CHNGBUF, &svsk->sk_flags);
902 }
903
904 /*
905  * A data_ready event on a listening socket means there's a connection
906  * pending. Do not use state_change as a substitute for it.
907  */
908 static void
909 svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
910 {
911         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
912
913         dprintk("svc: socket %p TCP (listen) state change %d\n",
914                 sk, sk->sk_state);
915
916         /*
917          * This callback may called twice when a new connection
918          * is established as a child socket inherits everything
919          * from a parent LISTEN socket.
920          * 1) data_ready method of the parent socket will be called
921          *    when one of child sockets become ESTABLISHED.
922          * 2) data_ready method of the child socket may be called
923          *    when it receives data before the socket is accepted.
924          * In case of 2, we should ignore it silently.
925          */
926         if (sk->sk_state == TCP_LISTEN) {
927                 if (svsk) {
928                         set_bit(SK_CONN, &svsk->sk_flags);
929                         svc_sock_enqueue(svsk);
930                 } else
931                         printk("svc: socket %p: no user data\n", sk);
932         }
933
934         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
935                 wake_up_interruptible_all(sk->sk_sleep);
936 }
937
938 /*
939  * A state change on a connected socket means it's dying or dead.
940  */
941 static void
942 svc_tcp_state_change(struct sock *sk)
943 {
944         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
945
946         dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
947                 sk, sk->sk_state, sk->sk_user_data);
948
949         if (!svsk)
950                 printk("svc: socket %p: no user data\n", sk);
951         else {
952                 set_bit(SK_CLOSE, &svsk->sk_flags);
953                 svc_sock_enqueue(svsk);
954         }
955         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
956                 wake_up_interruptible_all(sk->sk_sleep);
957 }
958
959 static void
960 svc_tcp_data_ready(struct sock *sk, int count)
961 {
962         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
963
964         dprintk("svc: socket %p TCP data ready (svsk %p)\n",
965                 sk, sk->sk_user_data);
966         if (svsk) {
967                 set_bit(SK_DATA, &svsk->sk_flags);
968                 svc_sock_enqueue(svsk);
969         }
970         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
971                 wake_up_interruptible(sk->sk_sleep);
972 }
973
974 static inline int svc_port_is_privileged(struct sockaddr *sin)
975 {
976         switch (sin->sa_family) {
977         case AF_INET:
978                 return ntohs(((struct sockaddr_in *)sin)->sin_port)
979                         < PROT_SOCK;
980 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
981         case AF_INET6:
982                 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
983                         < PROT_SOCK;
984 #endif
985         default:
986                 return 0;
987         }
988 }
989
990 /*
991  * Accept a TCP connection
992  */
993 static void
994 svc_tcp_accept(struct svc_sock *svsk)
995 {
996         struct sockaddr_storage addr;
997         struct sockaddr *sin = (struct sockaddr *) &addr;
998         struct svc_serv *serv = svsk->sk_server;
999         struct socket   *sock = svsk->sk_sock;
1000         struct socket   *newsock;
1001         struct svc_sock *newsvsk;
1002         int             err, slen;
1003         char            buf[RPC_MAX_ADDRBUFLEN];
1004
1005         dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
1006         if (!sock)
1007                 return;
1008
1009         clear_bit(SK_CONN, &svsk->sk_flags);
1010         err = kernel_accept(sock, &newsock, O_NONBLOCK);
1011         if (err < 0) {
1012                 if (err == -ENOMEM)
1013                         printk(KERN_WARNING "%s: no more sockets!\n",
1014                                serv->sv_name);
1015                 else if (err != -EAGAIN && net_ratelimit())
1016                         printk(KERN_WARNING "%s: accept failed (err %d)!\n",
1017                                    serv->sv_name, -err);
1018                 return;
1019         }
1020
1021         set_bit(SK_CONN, &svsk->sk_flags);
1022         svc_sock_enqueue(svsk);
1023
1024         err = kernel_getpeername(newsock, sin, &slen);
1025         if (err < 0) {
1026                 if (net_ratelimit())
1027                         printk(KERN_WARNING "%s: peername failed (err %d)!\n",
1028                                    serv->sv_name, -err);
1029                 goto failed;            /* aborted connection or whatever */
1030         }
1031
1032         /* Ideally, we would want to reject connections from unauthorized
1033          * hosts here, but when we get encryption, the IP of the host won't
1034          * tell us anything.  For now just warn about unpriv connections.
1035          */
1036         if (!svc_port_is_privileged(sin)) {
1037                 dprintk(KERN_WARNING
1038                         "%s: connect from unprivileged port: %s\n",
1039                         serv->sv_name,
1040                         __svc_print_addr(sin, buf, sizeof(buf)));
1041         }
1042         dprintk("%s: connect from %s\n", serv->sv_name,
1043                 __svc_print_addr(sin, buf, sizeof(buf)));
1044
1045         /* make sure that a write doesn't block forever when
1046          * low on memory
1047          */
1048         newsock->sk->sk_sndtimeo = HZ*30;
1049
1050         if (!(newsvsk = svc_setup_socket(serv, newsock, &err,
1051                                  (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY))))
1052                 goto failed;
1053         memcpy(&newsvsk->sk_remote, sin, slen);
1054         newsvsk->sk_remotelen = slen;
1055
1056         svc_sock_received(newsvsk);
1057
1058         /* make sure that we don't have too many active connections.
1059          * If we have, something must be dropped.
1060          *
1061          * There's no point in trying to do random drop here for
1062          * DoS prevention. The NFS clients does 1 reconnect in 15
1063          * seconds. An attacker can easily beat that.
1064          *
1065          * The only somewhat efficient mechanism would be if drop
1066          * old connections from the same IP first. But right now
1067          * we don't even record the client IP in svc_sock.
1068          */
1069         if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
1070                 struct svc_sock *svsk = NULL;
1071                 spin_lock_bh(&serv->sv_lock);
1072                 if (!list_empty(&serv->sv_tempsocks)) {
1073                         if (net_ratelimit()) {
1074                                 /* Try to help the admin */
1075                                 printk(KERN_NOTICE "%s: too many open TCP "
1076                                         "sockets, consider increasing the "
1077                                         "number of nfsd threads\n",
1078                                                    serv->sv_name);
1079                                 printk(KERN_NOTICE
1080                                        "%s: last TCP connect from %s\n",
1081                                        serv->sv_name, buf);
1082                         }
1083                         /*
1084                          * Always select the oldest socket. It's not fair,
1085                          * but so is life
1086                          */
1087                         svsk = list_entry(serv->sv_tempsocks.prev,
1088                                           struct svc_sock,
1089                                           sk_list);
1090                         set_bit(SK_CLOSE, &svsk->sk_flags);
1091                         atomic_inc(&svsk->sk_inuse);
1092                 }
1093                 spin_unlock_bh(&serv->sv_lock);
1094
1095                 if (svsk) {
1096                         svc_sock_enqueue(svsk);
1097                         svc_sock_put(svsk);
1098                 }
1099
1100         }
1101
1102         if (serv->sv_stats)
1103                 serv->sv_stats->nettcpconn++;
1104
1105         return;
1106
1107 failed:
1108         sock_release(newsock);
1109         return;
1110 }
1111
1112 /*
1113  * Receive data from a TCP socket.
1114  */
1115 static int
1116 svc_tcp_recvfrom(struct svc_rqst *rqstp)
1117 {
1118         struct svc_sock *svsk = rqstp->rq_sock;
1119         struct svc_serv *serv = svsk->sk_server;
1120         int             len;
1121         struct kvec *vec;
1122         int pnum, vlen;
1123
1124         dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
1125                 svsk, test_bit(SK_DATA, &svsk->sk_flags),
1126                 test_bit(SK_CONN, &svsk->sk_flags),
1127                 test_bit(SK_CLOSE, &svsk->sk_flags));
1128
1129         if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
1130                 svc_sock_received(svsk);
1131                 return svc_deferred_recv(rqstp);
1132         }
1133
1134         if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
1135                 svc_delete_socket(svsk);
1136                 return 0;
1137         }
1138
1139         if (svsk->sk_sk->sk_state == TCP_LISTEN) {
1140                 svc_tcp_accept(svsk);
1141                 svc_sock_received(svsk);
1142                 return 0;
1143         }
1144
1145         if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
1146                 /* sndbuf needs to have room for one request
1147                  * per thread, otherwise we can stall even when the
1148                  * network isn't a bottleneck.
1149                  *
1150                  * We count all threads rather than threads in a
1151                  * particular pool, which provides an upper bound
1152                  * on the number of threads which will access the socket.
1153                  *
1154                  * rcvbuf just needs to be able to hold a few requests.
1155                  * Normally they will be removed from the queue
1156                  * as soon a a complete request arrives.
1157                  */
1158                 svc_sock_setbufsize(svsk->sk_sock,
1159                                     (serv->sv_nrthreads+3) * serv->sv_max_mesg,
1160                                     3 * serv->sv_max_mesg);
1161
1162         clear_bit(SK_DATA, &svsk->sk_flags);
1163
1164         /* Receive data. If we haven't got the record length yet, get
1165          * the next four bytes. Otherwise try to gobble up as much as
1166          * possible up to the complete record length.
1167          */
1168         if (svsk->sk_tcplen < 4) {
1169                 unsigned long   want = 4 - svsk->sk_tcplen;
1170                 struct kvec     iov;
1171
1172                 iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
1173                 iov.iov_len  = want;
1174                 if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
1175                         goto error;
1176                 svsk->sk_tcplen += len;
1177
1178                 if (len < want) {
1179                         dprintk("svc: short recvfrom while reading record length (%d of %lu)\n",
1180                                 len, want);
1181                         svc_sock_received(svsk);
1182                         return -EAGAIN; /* record header not complete */
1183                 }
1184
1185                 svsk->sk_reclen = ntohl(svsk->sk_reclen);
1186                 if (!(svsk->sk_reclen & 0x80000000)) {
1187                         /* FIXME: technically, a record can be fragmented,
1188                          *  and non-terminal fragments will not have the top
1189                          *  bit set in the fragment length header.
1190                          *  But apparently no known nfs clients send fragmented
1191                          *  records. */
1192                         if (net_ratelimit())
1193                                 printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx"
1194                                        " (non-terminal)\n",
1195                                        (unsigned long) svsk->sk_reclen);
1196                         goto err_delete;
1197                 }
1198                 svsk->sk_reclen &= 0x7fffffff;
1199                 dprintk("svc: TCP record, %d bytes\n", svsk->sk_reclen);
1200                 if (svsk->sk_reclen > serv->sv_max_mesg) {
1201                         if (net_ratelimit())
1202                                 printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx"
1203                                        " (large)\n",
1204                                        (unsigned long) svsk->sk_reclen);
1205                         goto err_delete;
1206                 }
1207         }
1208
1209         /* Check whether enough data is available */
1210         len = svc_recv_available(svsk);
1211         if (len < 0)
1212                 goto error;
1213
1214         if (len < svsk->sk_reclen) {
1215                 dprintk("svc: incomplete TCP record (%d of %d)\n",
1216                         len, svsk->sk_reclen);
1217                 svc_sock_received(svsk);
1218                 return -EAGAIN; /* record not complete */
1219         }
1220         len = svsk->sk_reclen;
1221         set_bit(SK_DATA, &svsk->sk_flags);
1222
1223         vec = rqstp->rq_vec;
1224         vec[0] = rqstp->rq_arg.head[0];
1225         vlen = PAGE_SIZE;
1226         pnum = 1;
1227         while (vlen < len) {
1228                 vec[pnum].iov_base = page_address(rqstp->rq_pages[pnum]);
1229                 vec[pnum].iov_len = PAGE_SIZE;
1230                 pnum++;
1231                 vlen += PAGE_SIZE;
1232         }
1233         rqstp->rq_respages = &rqstp->rq_pages[pnum];
1234
1235         /* Now receive data */
1236         len = svc_recvfrom(rqstp, vec, pnum, len);
1237         if (len < 0)
1238                 goto error;
1239
1240         dprintk("svc: TCP complete record (%d bytes)\n", len);
1241         rqstp->rq_arg.len = len;
1242         rqstp->rq_arg.page_base = 0;
1243         if (len <= rqstp->rq_arg.head[0].iov_len) {
1244                 rqstp->rq_arg.head[0].iov_len = len;
1245                 rqstp->rq_arg.page_len = 0;
1246         } else {
1247                 rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
1248         }
1249
1250         rqstp->rq_skbuff      = NULL;
1251         rqstp->rq_prot        = IPPROTO_TCP;
1252
1253         /* Reset TCP read info */
1254         svsk->sk_reclen = 0;
1255         svsk->sk_tcplen = 0;
1256
1257         svc_sock_received(svsk);
1258         if (serv->sv_stats)
1259                 serv->sv_stats->nettcpcnt++;
1260
1261         return len;
1262
1263  err_delete:
1264         svc_delete_socket(svsk);
1265         return -EAGAIN;
1266
1267  error:
1268         if (len == -EAGAIN) {
1269                 dprintk("RPC: TCP recvfrom got EAGAIN\n");
1270                 svc_sock_received(svsk);
1271         } else {
1272                 printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
1273                                         svsk->sk_server->sv_name, -len);
1274                 goto err_delete;
1275         }
1276
1277         return len;
1278 }
1279
1280 /*
1281  * Send out data on TCP socket.
1282  */
1283 static int
1284 svc_tcp_sendto(struct svc_rqst *rqstp)
1285 {
1286         struct xdr_buf  *xbufp = &rqstp->rq_res;
1287         int sent;
1288         __be32 reclen;
1289
1290         /* Set up the first element of the reply kvec.
1291          * Any other kvecs that may be in use have been taken
1292          * care of by the server implementation itself.
1293          */
1294         reclen = htonl(0x80000000|((xbufp->len ) - 4));
1295         memcpy(xbufp->head[0].iov_base, &reclen, 4);
1296
1297         if (test_bit(SK_DEAD, &rqstp->rq_sock->sk_flags))
1298                 return -ENOTCONN;
1299
1300         sent = svc_sendto(rqstp, &rqstp->rq_res);
1301         if (sent != xbufp->len) {
1302                 printk(KERN_NOTICE "rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
1303                        rqstp->rq_sock->sk_server->sv_name,
1304                        (sent<0)?"got error":"sent only",
1305                        sent, xbufp->len);
1306                 set_bit(SK_CLOSE, &rqstp->rq_sock->sk_flags);
1307                 svc_sock_enqueue(rqstp->rq_sock);
1308                 sent = -EAGAIN;
1309         }
1310         return sent;
1311 }
1312
1313 static void
1314 svc_tcp_init(struct svc_sock *svsk)
1315 {
1316         struct sock     *sk = svsk->sk_sk;
1317         struct tcp_sock *tp = tcp_sk(sk);
1318
1319         svsk->sk_recvfrom = svc_tcp_recvfrom;
1320         svsk->sk_sendto = svc_tcp_sendto;
1321
1322         if (sk->sk_state == TCP_LISTEN) {
1323                 dprintk("setting up TCP socket for listening\n");
1324                 sk->sk_data_ready = svc_tcp_listen_data_ready;
1325                 set_bit(SK_CONN, &svsk->sk_flags);
1326         } else {
1327                 dprintk("setting up TCP socket for reading\n");
1328                 sk->sk_state_change = svc_tcp_state_change;
1329                 sk->sk_data_ready = svc_tcp_data_ready;
1330                 sk->sk_write_space = svc_write_space;
1331
1332                 svsk->sk_reclen = 0;
1333                 svsk->sk_tcplen = 0;
1334
1335                 tp->nonagle = 1;        /* disable Nagle's algorithm */
1336
1337                 /* initialise setting must have enough space to
1338                  * receive and respond to one request.
1339                  * svc_tcp_recvfrom will re-adjust if necessary
1340                  */
1341                 svc_sock_setbufsize(svsk->sk_sock,
1342                                     3 * svsk->sk_server->sv_max_mesg,
1343                                     3 * svsk->sk_server->sv_max_mesg);
1344
1345                 set_bit(SK_CHNGBUF, &svsk->sk_flags);
1346                 set_bit(SK_DATA, &svsk->sk_flags);
1347                 if (sk->sk_state != TCP_ESTABLISHED)
1348                         set_bit(SK_CLOSE, &svsk->sk_flags);
1349         }
1350 }
1351
1352 void
1353 svc_sock_update_bufs(struct svc_serv *serv)
1354 {
1355         /*
1356          * The number of server threads has changed. Update
1357          * rcvbuf and sndbuf accordingly on all sockets
1358          */
1359         struct list_head *le;
1360
1361         spin_lock_bh(&serv->sv_lock);
1362         list_for_each(le, &serv->sv_permsocks) {
1363                 struct svc_sock *svsk =
1364                         list_entry(le, struct svc_sock, sk_list);
1365                 set_bit(SK_CHNGBUF, &svsk->sk_flags);
1366         }
1367         list_for_each(le, &serv->sv_tempsocks) {
1368                 struct svc_sock *svsk =
1369                         list_entry(le, struct svc_sock, sk_list);
1370                 set_bit(SK_CHNGBUF, &svsk->sk_flags);
1371         }
1372         spin_unlock_bh(&serv->sv_lock);
1373 }
1374
1375 /*
1376  * Receive the next request on any socket.  This code is carefully
1377  * organised not to touch any cachelines in the shared svc_serv
1378  * structure, only cachelines in the local svc_pool.
1379  */
1380 int
1381 svc_recv(struct svc_rqst *rqstp, long timeout)
1382 {
1383         struct svc_sock         *svsk = NULL;
1384         struct svc_serv         *serv = rqstp->rq_server;
1385         struct svc_pool         *pool = rqstp->rq_pool;
1386         int                     len, i;
1387         int                     pages;
1388         struct xdr_buf          *arg;
1389         DECLARE_WAITQUEUE(wait, current);
1390
1391         dprintk("svc: server %p waiting for data (to = %ld)\n",
1392                 rqstp, timeout);
1393
1394         if (rqstp->rq_sock)
1395                 printk(KERN_ERR
1396                         "svc_recv: service %p, socket not NULL!\n",
1397                          rqstp);
1398         if (waitqueue_active(&rqstp->rq_wait))
1399                 printk(KERN_ERR
1400                         "svc_recv: service %p, wait queue active!\n",
1401                          rqstp);
1402
1403
1404         /* now allocate needed pages.  If we get a failure, sleep briefly */
1405         pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
1406         for (i=0; i < pages ; i++)
1407                 while (rqstp->rq_pages[i] == NULL) {
1408                         struct page *p = alloc_page(GFP_KERNEL);
1409                         if (!p)
1410                                 schedule_timeout_uninterruptible(msecs_to_jiffies(500));
1411                         rqstp->rq_pages[i] = p;
1412                 }
1413         rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
1414         BUG_ON(pages >= RPCSVC_MAXPAGES);
1415
1416         /* Make arg->head point to first page and arg->pages point to rest */
1417         arg = &rqstp->rq_arg;
1418         arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
1419         arg->head[0].iov_len = PAGE_SIZE;
1420         arg->pages = rqstp->rq_pages + 1;
1421         arg->page_base = 0;
1422         /* save at least one page for response */
1423         arg->page_len = (pages-2)*PAGE_SIZE;
1424         arg->len = (pages-1)*PAGE_SIZE;
1425         arg->tail[0].iov_len = 0;
1426
1427         try_to_freeze();
1428         cond_resched();
1429         if (signalled())
1430                 return -EINTR;
1431
1432         spin_lock_bh(&pool->sp_lock);
1433         if ((svsk = svc_sock_dequeue(pool)) != NULL) {
1434                 rqstp->rq_sock = svsk;
1435                 atomic_inc(&svsk->sk_inuse);
1436                 rqstp->rq_reserved = serv->sv_max_mesg;
1437                 atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
1438         } else {
1439                 /* No data pending. Go to sleep */
1440                 svc_thread_enqueue(pool, rqstp);
1441
1442                 /*
1443                  * We have to be able to interrupt this wait
1444                  * to bring down the daemons ...
1445                  */
1446                 set_current_state(TASK_INTERRUPTIBLE);
1447                 add_wait_queue(&rqstp->rq_wait, &wait);
1448                 spin_unlock_bh(&pool->sp_lock);
1449
1450                 schedule_timeout(timeout);
1451
1452                 try_to_freeze();
1453
1454                 spin_lock_bh(&pool->sp_lock);
1455                 remove_wait_queue(&rqstp->rq_wait, &wait);
1456
1457                 if (!(svsk = rqstp->rq_sock)) {
1458                         svc_thread_dequeue(pool, rqstp);
1459                         spin_unlock_bh(&pool->sp_lock);
1460                         dprintk("svc: server %p, no data yet\n", rqstp);
1461                         return signalled()? -EINTR : -EAGAIN;
1462                 }
1463         }
1464         spin_unlock_bh(&pool->sp_lock);
1465
1466         dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",
1467                  rqstp, pool->sp_id, svsk, atomic_read(&svsk->sk_inuse));
1468         len = svsk->sk_recvfrom(rqstp);
1469         dprintk("svc: got len=%d\n", len);
1470
1471         /* No data, incomplete (TCP) read, or accept() */
1472         if (len == 0 || len == -EAGAIN) {
1473                 rqstp->rq_res.len = 0;
1474                 svc_sock_release(rqstp);
1475                 return -EAGAIN;
1476         }
1477         svsk->sk_lastrecv = get_seconds();
1478         clear_bit(SK_OLD, &svsk->sk_flags);
1479
1480         rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
1481         rqstp->rq_chandle.defer = svc_defer;
1482
1483         if (serv->sv_stats)
1484                 serv->sv_stats->netcnt++;
1485         return len;
1486 }
1487
1488 /*
1489  * Drop request
1490  */
1491 void
1492 svc_drop(struct svc_rqst *rqstp)
1493 {
1494         dprintk("svc: socket %p dropped request\n", rqstp->rq_sock);
1495         svc_sock_release(rqstp);
1496 }
1497
1498 /*
1499  * Return reply to client.
1500  */
1501 int
1502 svc_send(struct svc_rqst *rqstp)
1503 {
1504         struct svc_sock *svsk;
1505         int             len;
1506         struct xdr_buf  *xb;
1507
1508         if ((svsk = rqstp->rq_sock) == NULL) {
1509                 printk(KERN_WARNING "NULL socket pointer in %s:%d\n",
1510                                 __FILE__, __LINE__);
1511                 return -EFAULT;
1512         }
1513
1514         /* release the receive skb before sending the reply */
1515         svc_release_skb(rqstp);
1516
1517         /* calculate over-all length */
1518         xb = & rqstp->rq_res;
1519         xb->len = xb->head[0].iov_len +
1520                 xb->page_len +
1521                 xb->tail[0].iov_len;
1522
1523         /* Grab svsk->sk_mutex to serialize outgoing data. */
1524         mutex_lock(&svsk->sk_mutex);
1525         if (test_bit(SK_DEAD, &svsk->sk_flags))
1526                 len = -ENOTCONN;
1527         else
1528                 len = svsk->sk_sendto(rqstp);
1529         mutex_unlock(&svsk->sk_mutex);
1530         svc_sock_release(rqstp);
1531
1532         if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
1533                 return 0;
1534         return len;
1535 }
1536
1537 /*
1538  * Timer function to close old temporary sockets, using
1539  * a mark-and-sweep algorithm.
1540  */
1541 static void
1542 svc_age_temp_sockets(unsigned long closure)
1543 {
1544         struct svc_serv *serv = (struct svc_serv *)closure;
1545         struct svc_sock *svsk;
1546         struct list_head *le, *next;
1547         LIST_HEAD(to_be_aged);
1548
1549         dprintk("svc_age_temp_sockets\n");
1550
1551         if (!spin_trylock_bh(&serv->sv_lock)) {
1552                 /* busy, try again 1 sec later */
1553                 dprintk("svc_age_temp_sockets: busy\n");
1554                 mod_timer(&serv->sv_temptimer, jiffies + HZ);
1555                 return;
1556         }
1557
1558         list_for_each_safe(le, next, &serv->sv_tempsocks) {
1559                 svsk = list_entry(le, struct svc_sock, sk_list);
1560
1561                 if (!test_and_set_bit(SK_OLD, &svsk->sk_flags))
1562                         continue;
1563                 if (atomic_read(&svsk->sk_inuse) || test_bit(SK_BUSY, &svsk->sk_flags))
1564                         continue;
1565                 atomic_inc(&svsk->sk_inuse);
1566                 list_move(le, &to_be_aged);
1567                 set_bit(SK_CLOSE, &svsk->sk_flags);
1568                 set_bit(SK_DETACHED, &svsk->sk_flags);
1569         }
1570         spin_unlock_bh(&serv->sv_lock);
1571
1572         while (!list_empty(&to_be_aged)) {
1573                 le = to_be_aged.next;
1574                 /* fiddling the sk_list node is safe 'cos we're SK_DETACHED */
1575                 list_del_init(le);
1576                 svsk = list_entry(le, struct svc_sock, sk_list);
1577
1578                 dprintk("queuing svsk %p for closing, %lu seconds old\n",
1579                         svsk, get_seconds() - svsk->sk_lastrecv);
1580
1581                 /* a thread will dequeue and close it soon */
1582                 svc_sock_enqueue(svsk);
1583                 svc_sock_put(svsk);
1584         }
1585
1586         mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
1587 }
1588
1589 /*
1590  * Initialize socket for RPC use and create svc_sock struct
1591  * XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
1592  */
1593 static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1594                                                 struct socket *sock,
1595                                                 int *errp, int flags)
1596 {
1597         struct svc_sock *svsk;
1598         struct sock     *inet;
1599         int             pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1600         int             is_temporary = flags & SVC_SOCK_TEMPORARY;
1601
1602         dprintk("svc: svc_setup_socket %p\n", sock);
1603         if (!(svsk = kzalloc(sizeof(*svsk), GFP_KERNEL))) {
1604                 *errp = -ENOMEM;
1605                 return NULL;
1606         }
1607
1608         inet = sock->sk;
1609
1610         /* Register socket with portmapper */
1611         if (*errp >= 0 && pmap_register)
1612                 *errp = svc_register(serv, inet->sk_protocol,
1613                                      ntohs(inet_sk(inet)->sport));
1614
1615         if (*errp < 0) {
1616                 kfree(svsk);
1617                 return NULL;
1618         }
1619
1620         set_bit(SK_BUSY, &svsk->sk_flags);
1621         inet->sk_user_data = svsk;
1622         svsk->sk_sock = sock;
1623         svsk->sk_sk = inet;
1624         svsk->sk_ostate = inet->sk_state_change;
1625         svsk->sk_odata = inet->sk_data_ready;
1626         svsk->sk_owspace = inet->sk_write_space;
1627         svsk->sk_server = serv;
1628         atomic_set(&svsk->sk_inuse, 1);
1629         svsk->sk_lastrecv = get_seconds();
1630         spin_lock_init(&svsk->sk_defer_lock);
1631         INIT_LIST_HEAD(&svsk->sk_deferred);
1632         INIT_LIST_HEAD(&svsk->sk_ready);
1633         mutex_init(&svsk->sk_mutex);
1634
1635         /* Initialize the socket */
1636         if (sock->type == SOCK_DGRAM)
1637                 svc_udp_init(svsk);
1638         else
1639                 svc_tcp_init(svsk);
1640
1641         spin_lock_bh(&serv->sv_lock);
1642         if (is_temporary) {
1643                 set_bit(SK_TEMP, &svsk->sk_flags);
1644                 list_add(&svsk->sk_list, &serv->sv_tempsocks);
1645                 serv->sv_tmpcnt++;
1646                 if (serv->sv_temptimer.function == NULL) {
1647                         /* setup timer to age temp sockets */
1648                         setup_timer(&serv->sv_temptimer, svc_age_temp_sockets,
1649                                         (unsigned long)serv);
1650                         mod_timer(&serv->sv_temptimer,
1651                                         jiffies + svc_conn_age_period * HZ);
1652                 }
1653         } else {
1654                 clear_bit(SK_TEMP, &svsk->sk_flags);
1655                 list_add(&svsk->sk_list, &serv->sv_permsocks);
1656         }
1657         spin_unlock_bh(&serv->sv_lock);
1658
1659         dprintk("svc: svc_setup_socket created %p (inet %p)\n",
1660                                 svsk, svsk->sk_sk);
1661
1662         return svsk;
1663 }
1664
1665 int svc_addsock(struct svc_serv *serv,
1666                 int fd,
1667                 char *name_return,
1668                 int *proto)
1669 {
1670         int err = 0;
1671         struct socket *so = sockfd_lookup(fd, &err);
1672         struct svc_sock *svsk = NULL;
1673
1674         if (!so)
1675                 return err;
1676         if (so->sk->sk_family != AF_INET)
1677                 err =  -EAFNOSUPPORT;
1678         else if (so->sk->sk_protocol != IPPROTO_TCP &&
1679             so->sk->sk_protocol != IPPROTO_UDP)
1680                 err =  -EPROTONOSUPPORT;
1681         else if (so->state > SS_UNCONNECTED)
1682                 err = -EISCONN;
1683         else {
1684                 svsk = svc_setup_socket(serv, so, &err, SVC_SOCK_DEFAULTS);
1685                 if (svsk) {
1686                         svc_sock_received(svsk);
1687                         err = 0;
1688                 }
1689         }
1690         if (err) {
1691                 sockfd_put(so);
1692                 return err;
1693         }
1694         if (proto) *proto = so->sk->sk_protocol;
1695         return one_sock_name(name_return, svsk);
1696 }
1697 EXPORT_SYMBOL_GPL(svc_addsock);
1698
1699 /*
1700  * Create socket for RPC service.
1701  */
1702 static int svc_create_socket(struct svc_serv *serv, int protocol,
1703                                 struct sockaddr *sin, int len, int flags)
1704 {
1705         struct svc_sock *svsk;
1706         struct socket   *sock;
1707         int             error;
1708         int             type;
1709         char            buf[RPC_MAX_ADDRBUFLEN];
1710
1711         dprintk("svc: svc_create_socket(%s, %d, %s)\n",
1712                         serv->sv_program->pg_name, protocol,
1713                         __svc_print_addr(sin, buf, sizeof(buf)));
1714
1715         if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1716                 printk(KERN_WARNING "svc: only UDP and TCP "
1717                                 "sockets supported\n");
1718                 return -EINVAL;
1719         }
1720         type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1721
1722         error = sock_create_kern(sin->sa_family, type, protocol, &sock);
1723         if (error < 0)
1724                 return error;
1725
1726         svc_reclassify_socket(sock);
1727
1728         if (type == SOCK_STREAM)
1729                 sock->sk->sk_reuse = 1;         /* allow address reuse */
1730         error = kernel_bind(sock, sin, len);
1731         if (error < 0)
1732                 goto bummer;
1733
1734         if (protocol == IPPROTO_TCP) {
1735                 if ((error = kernel_listen(sock, 64)) < 0)
1736                         goto bummer;
1737         }
1738
1739         if ((svsk = svc_setup_socket(serv, sock, &error, flags)) != NULL) {
1740                 svc_sock_received(svsk);
1741                 return ntohs(inet_sk(svsk->sk_sk)->sport);
1742         }
1743
1744 bummer:
1745         dprintk("svc: svc_create_socket error = %d\n", -error);
1746         sock_release(sock);
1747         return error;
1748 }
1749
1750 /*
1751  * Remove a dead socket
1752  */
1753 static void
1754 svc_delete_socket(struct svc_sock *svsk)
1755 {
1756         struct svc_serv *serv;
1757         struct sock     *sk;
1758
1759         dprintk("svc: svc_delete_socket(%p)\n", svsk);
1760
1761         serv = svsk->sk_server;
1762         sk = svsk->sk_sk;
1763
1764         sk->sk_state_change = svsk->sk_ostate;
1765         sk->sk_data_ready = svsk->sk_odata;
1766         sk->sk_write_space = svsk->sk_owspace;
1767
1768         spin_lock_bh(&serv->sv_lock);
1769
1770         if (!test_and_set_bit(SK_DETACHED, &svsk->sk_flags))
1771                 list_del_init(&svsk->sk_list);
1772         /*
1773          * We used to delete the svc_sock from whichever list
1774          * it's sk_ready node was on, but we don't actually
1775          * need to.  This is because the only time we're called
1776          * while still attached to a queue, the queue itself
1777          * is about to be destroyed (in svc_destroy).
1778          */
1779         if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags)) {
1780                 BUG_ON(atomic_read(&svsk->sk_inuse)<2);
1781                 atomic_dec(&svsk->sk_inuse);
1782                 if (test_bit(SK_TEMP, &svsk->sk_flags))
1783                         serv->sv_tmpcnt--;
1784         }
1785
1786         spin_unlock_bh(&serv->sv_lock);
1787 }
1788
1789 void svc_close_socket(struct svc_sock *svsk)
1790 {
1791         set_bit(SK_CLOSE, &svsk->sk_flags);
1792         if (test_and_set_bit(SK_BUSY, &svsk->sk_flags))
1793                 /* someone else will have to effect the close */
1794                 return;
1795
1796         atomic_inc(&svsk->sk_inuse);
1797         svc_delete_socket(svsk);
1798         clear_bit(SK_BUSY, &svsk->sk_flags);
1799         svc_sock_put(svsk);
1800 }
1801
1802 /**
1803  * svc_makesock - Make a socket for nfsd and lockd
1804  * @serv: RPC server structure
1805  * @protocol: transport protocol to use
1806  * @port: port to use
1807  * @flags: requested socket characteristics
1808  *
1809  */
1810 int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port,
1811                         int flags)
1812 {
1813         struct sockaddr_in sin = {
1814                 .sin_family             = AF_INET,
1815                 .sin_addr.s_addr        = INADDR_ANY,
1816                 .sin_port               = htons(port),
1817         };
1818
1819         dprintk("svc: creating socket proto = %d\n", protocol);
1820         return svc_create_socket(serv, protocol, (struct sockaddr *) &sin,
1821                                                         sizeof(sin), flags);
1822 }
1823
1824 /*
1825  * Handle defer and revisit of requests
1826  */
1827
1828 static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
1829 {
1830         struct svc_deferred_req *dr = container_of(dreq, struct svc_deferred_req, handle);
1831         struct svc_sock *svsk;
1832
1833         if (too_many) {
1834                 svc_sock_put(dr->svsk);
1835                 kfree(dr);
1836                 return;
1837         }
1838         dprintk("revisit queued\n");
1839         svsk = dr->svsk;
1840         dr->svsk = NULL;
1841         spin_lock_bh(&svsk->sk_defer_lock);
1842         list_add(&dr->handle.recent, &svsk->sk_deferred);
1843         spin_unlock_bh(&svsk->sk_defer_lock);
1844         set_bit(SK_DEFERRED, &svsk->sk_flags);
1845         svc_sock_enqueue(svsk);
1846         svc_sock_put(svsk);
1847 }
1848
1849 static struct cache_deferred_req *
1850 svc_defer(struct cache_req *req)
1851 {
1852         struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
1853         int size = sizeof(struct svc_deferred_req) + (rqstp->rq_arg.len);
1854         struct svc_deferred_req *dr;
1855
1856         if (rqstp->rq_arg.page_len)
1857                 return NULL; /* if more than a page, give up FIXME */
1858         if (rqstp->rq_deferred) {
1859                 dr = rqstp->rq_deferred;
1860                 rqstp->rq_deferred = NULL;
1861         } else {
1862                 int skip  = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1863                 /* FIXME maybe discard if size too large */
1864                 dr = kmalloc(size, GFP_KERNEL);
1865                 if (dr == NULL)
1866                         return NULL;
1867
1868                 dr->handle.owner = rqstp->rq_server;
1869                 dr->prot = rqstp->rq_prot;
1870                 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1871                 dr->addrlen = rqstp->rq_addrlen;
1872                 dr->daddr = rqstp->rq_daddr;
1873                 dr->argslen = rqstp->rq_arg.len >> 2;
1874                 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2);
1875         }
1876         atomic_inc(&rqstp->rq_sock->sk_inuse);
1877         dr->svsk = rqstp->rq_sock;
1878
1879         dr->handle.revisit = svc_revisit;
1880         return &dr->handle;
1881 }
1882
1883 /*
1884  * recv data from a deferred request into an active one
1885  */
1886 static int svc_deferred_recv(struct svc_rqst *rqstp)
1887 {
1888         struct svc_deferred_req *dr = rqstp->rq_deferred;
1889
1890         rqstp->rq_arg.head[0].iov_base = dr->args;
1891         rqstp->rq_arg.head[0].iov_len = dr->argslen<<2;
1892         rqstp->rq_arg.page_len = 0;
1893         rqstp->rq_arg.len = dr->argslen<<2;
1894         rqstp->rq_prot        = dr->prot;
1895         memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1896         rqstp->rq_addrlen     = dr->addrlen;
1897         rqstp->rq_daddr       = dr->daddr;
1898         rqstp->rq_respages    = rqstp->rq_pages;
1899         return dr->argslen<<2;
1900 }
1901
1902
1903 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk)
1904 {
1905         struct svc_deferred_req *dr = NULL;
1906
1907         if (!test_bit(SK_DEFERRED, &svsk->sk_flags))
1908                 return NULL;
1909         spin_lock_bh(&svsk->sk_defer_lock);
1910         clear_bit(SK_DEFERRED, &svsk->sk_flags);
1911         if (!list_empty(&svsk->sk_deferred)) {
1912                 dr = list_entry(svsk->sk_deferred.next,
1913                                 struct svc_deferred_req,
1914                                 handle.recent);
1915                 list_del_init(&dr->handle.recent);
1916                 set_bit(SK_DEFERRED, &svsk->sk_flags);
1917         }
1918         spin_unlock_bh(&svsk->sk_defer_lock);
1919         return dr;
1920 }