[PATCH] knfsd: fix recently introduced problem with shutting down a busy NFS server
[linux-2.6.git] / 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 static void             svc_close_socket(struct svc_sock *svsk);
86
87 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
88 static int svc_deferred_recv(struct svc_rqst *rqstp);
89 static struct cache_deferred_req *svc_defer(struct cache_req *req);
90
91 /* apparently the "standard" is that clients close
92  * idle connections after 5 minutes, servers after
93  * 6 minutes
94  *   http://www.connectathon.org/talks96/nfstcp.pdf
95  */
96 static int svc_conn_age_period = 6*60;
97
98 #ifdef CONFIG_DEBUG_LOCK_ALLOC
99 static struct lock_class_key svc_key[2];
100 static struct lock_class_key svc_slock_key[2];
101
102 static inline void svc_reclassify_socket(struct socket *sock)
103 {
104         struct sock *sk = sock->sk;
105         BUG_ON(sk->sk_lock.owner != NULL);
106         switch (sk->sk_family) {
107         case AF_INET:
108                 sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
109                     &svc_slock_key[0], "sk_lock-AF_INET-NFSD", &svc_key[0]);
110                 break;
111
112         case AF_INET6:
113                 sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
114                     &svc_slock_key[1], "sk_lock-AF_INET6-NFSD", &svc_key[1]);
115                 break;
116
117         default:
118                 BUG();
119         }
120 }
121 #else
122 static inline void svc_reclassify_socket(struct socket *sock)
123 {
124 }
125 #endif
126
127 static char *__svc_print_addr(struct sockaddr *addr, char *buf, size_t len)
128 {
129         switch (addr->sa_family) {
130         case AF_INET:
131                 snprintf(buf, len, "%u.%u.%u.%u, port=%u",
132                         NIPQUAD(((struct sockaddr_in *) addr)->sin_addr),
133                         htons(((struct sockaddr_in *) addr)->sin_port));
134                 break;
135
136         case AF_INET6:
137                 snprintf(buf, len, "%x:%x:%x:%x:%x:%x:%x:%x, port=%u",
138                         NIP6(((struct sockaddr_in6 *) addr)->sin6_addr),
139                         htons(((struct sockaddr_in6 *) addr)->sin6_port));
140                 break;
141
142         default:
143                 snprintf(buf, len, "unknown address type: %d", addr->sa_family);
144                 break;
145         }
146         return buf;
147 }
148
149 /**
150  * svc_print_addr - Format rq_addr field for printing
151  * @rqstp: svc_rqst struct containing address to print
152  * @buf: target buffer for formatted address
153  * @len: length of target buffer
154  *
155  */
156 char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
157 {
158         return __svc_print_addr(svc_addr(rqstp), buf, len);
159 }
160 EXPORT_SYMBOL_GPL(svc_print_addr);
161
162 /*
163  * Queue up an idle server thread.  Must have pool->sp_lock held.
164  * Note: this is really a stack rather than a queue, so that we only
165  * use as many different threads as we need, and the rest don't pollute
166  * the cache.
167  */
168 static inline void
169 svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
170 {
171         list_add(&rqstp->rq_list, &pool->sp_threads);
172 }
173
174 /*
175  * Dequeue an nfsd thread.  Must have pool->sp_lock held.
176  */
177 static inline void
178 svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
179 {
180         list_del(&rqstp->rq_list);
181 }
182
183 /*
184  * Release an skbuff after use
185  */
186 static inline void
187 svc_release_skb(struct svc_rqst *rqstp)
188 {
189         struct sk_buff *skb = rqstp->rq_skbuff;
190         struct svc_deferred_req *dr = rqstp->rq_deferred;
191
192         if (skb) {
193                 rqstp->rq_skbuff = NULL;
194
195                 dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
196                 skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
197         }
198         if (dr) {
199                 rqstp->rq_deferred = NULL;
200                 kfree(dr);
201         }
202 }
203
204 /*
205  * Any space to write?
206  */
207 static inline unsigned long
208 svc_sock_wspace(struct svc_sock *svsk)
209 {
210         int wspace;
211
212         if (svsk->sk_sock->type == SOCK_STREAM)
213                 wspace = sk_stream_wspace(svsk->sk_sk);
214         else
215                 wspace = sock_wspace(svsk->sk_sk);
216
217         return wspace;
218 }
219
220 /*
221  * Queue up a socket with data pending. If there are idle nfsd
222  * processes, wake 'em up.
223  *
224  */
225 static void
226 svc_sock_enqueue(struct svc_sock *svsk)
227 {
228         struct svc_serv *serv = svsk->sk_server;
229         struct svc_pool *pool;
230         struct svc_rqst *rqstp;
231         int cpu;
232
233         if (!(svsk->sk_flags &
234               ( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)|(1<<SK_DEFERRED)) ))
235                 return;
236         if (test_bit(SK_DEAD, &svsk->sk_flags))
237                 return;
238
239         cpu = get_cpu();
240         pool = svc_pool_for_cpu(svsk->sk_server, cpu);
241         put_cpu();
242
243         spin_lock_bh(&pool->sp_lock);
244
245         if (!list_empty(&pool->sp_threads) &&
246             !list_empty(&pool->sp_sockets))
247                 printk(KERN_ERR
248                         "svc_sock_enqueue: threads and sockets both waiting??\n");
249
250         if (test_bit(SK_DEAD, &svsk->sk_flags)) {
251                 /* Don't enqueue dead sockets */
252                 dprintk("svc: socket %p is dead, not enqueued\n", svsk->sk_sk);
253                 goto out_unlock;
254         }
255
256         /* Mark socket as busy. It will remain in this state until the
257          * server has processed all pending data and put the socket back
258          * on the idle list.  We update SK_BUSY atomically because
259          * it also guards against trying to enqueue the svc_sock twice.
260          */
261         if (test_and_set_bit(SK_BUSY, &svsk->sk_flags)) {
262                 /* Don't enqueue socket while already enqueued */
263                 dprintk("svc: socket %p busy, not enqueued\n", svsk->sk_sk);
264                 goto out_unlock;
265         }
266         BUG_ON(svsk->sk_pool != NULL);
267         svsk->sk_pool = pool;
268
269         set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
270         if (((atomic_read(&svsk->sk_reserved) + serv->sv_max_mesg)*2
271              > svc_sock_wspace(svsk))
272             && !test_bit(SK_CLOSE, &svsk->sk_flags)
273             && !test_bit(SK_CONN, &svsk->sk_flags)) {
274                 /* Don't enqueue while not enough space for reply */
275                 dprintk("svc: socket %p  no space, %d*2 > %ld, not enqueued\n",
276                         svsk->sk_sk, atomic_read(&svsk->sk_reserved)+serv->sv_max_mesg,
277                         svc_sock_wspace(svsk));
278                 svsk->sk_pool = NULL;
279                 clear_bit(SK_BUSY, &svsk->sk_flags);
280                 goto out_unlock;
281         }
282         clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
283
284
285         if (!list_empty(&pool->sp_threads)) {
286                 rqstp = list_entry(pool->sp_threads.next,
287                                    struct svc_rqst,
288                                    rq_list);
289                 dprintk("svc: socket %p served by daemon %p\n",
290                         svsk->sk_sk, rqstp);
291                 svc_thread_dequeue(pool, rqstp);
292                 if (rqstp->rq_sock)
293                         printk(KERN_ERR
294                                 "svc_sock_enqueue: server %p, rq_sock=%p!\n",
295                                 rqstp, rqstp->rq_sock);
296                 rqstp->rq_sock = svsk;
297                 atomic_inc(&svsk->sk_inuse);
298                 rqstp->rq_reserved = serv->sv_max_mesg;
299                 atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
300                 BUG_ON(svsk->sk_pool != pool);
301                 wake_up(&rqstp->rq_wait);
302         } else {
303                 dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
304                 list_add_tail(&svsk->sk_ready, &pool->sp_sockets);
305                 BUG_ON(svsk->sk_pool != pool);
306         }
307
308 out_unlock:
309         spin_unlock_bh(&pool->sp_lock);
310 }
311
312 /*
313  * Dequeue the first socket.  Must be called with the pool->sp_lock held.
314  */
315 static inline struct svc_sock *
316 svc_sock_dequeue(struct svc_pool *pool)
317 {
318         struct svc_sock *svsk;
319
320         if (list_empty(&pool->sp_sockets))
321                 return NULL;
322
323         svsk = list_entry(pool->sp_sockets.next,
324                           struct svc_sock, sk_ready);
325         list_del_init(&svsk->sk_ready);
326
327         dprintk("svc: socket %p dequeued, inuse=%d\n",
328                 svsk->sk_sk, atomic_read(&svsk->sk_inuse));
329
330         return svsk;
331 }
332
333 /*
334  * Having read something from a socket, check whether it
335  * needs to be re-enqueued.
336  * Note: SK_DATA only gets cleared when a read-attempt finds
337  * no (or insufficient) data.
338  */
339 static inline void
340 svc_sock_received(struct svc_sock *svsk)
341 {
342         svsk->sk_pool = NULL;
343         clear_bit(SK_BUSY, &svsk->sk_flags);
344         svc_sock_enqueue(svsk);
345 }
346
347
348 /**
349  * svc_reserve - change the space reserved for the reply to a request.
350  * @rqstp:  The request in question
351  * @space: new max space to reserve
352  *
353  * Each request reserves some space on the output queue of the socket
354  * to make sure the reply fits.  This function reduces that reserved
355  * space to be the amount of space used already, plus @space.
356  *
357  */
358 void svc_reserve(struct svc_rqst *rqstp, int space)
359 {
360         space += rqstp->rq_res.head[0].iov_len;
361
362         if (space < rqstp->rq_reserved) {
363                 struct svc_sock *svsk = rqstp->rq_sock;
364                 atomic_sub((rqstp->rq_reserved - space), &svsk->sk_reserved);
365                 rqstp->rq_reserved = space;
366
367                 svc_sock_enqueue(svsk);
368         }
369 }
370
371 /*
372  * Release a socket after use.
373  */
374 static inline void
375 svc_sock_put(struct svc_sock *svsk)
376 {
377         if (atomic_dec_and_test(&svsk->sk_inuse)) {
378                 BUG_ON(! test_bit(SK_DEAD, &svsk->sk_flags));
379
380                 dprintk("svc: releasing dead socket\n");
381                 if (svsk->sk_sock->file)
382                         sockfd_put(svsk->sk_sock);
383                 else
384                         sock_release(svsk->sk_sock);
385                 if (svsk->sk_info_authunix != NULL)
386                         svcauth_unix_info_release(svsk->sk_info_authunix);
387                 kfree(svsk);
388         }
389 }
390
391 static void
392 svc_sock_release(struct svc_rqst *rqstp)
393 {
394         struct svc_sock *svsk = rqstp->rq_sock;
395
396         svc_release_skb(rqstp);
397
398         svc_free_res_pages(rqstp);
399         rqstp->rq_res.page_len = 0;
400         rqstp->rq_res.page_base = 0;
401
402
403         /* Reset response buffer and release
404          * the reservation.
405          * But first, check that enough space was reserved
406          * for the reply, otherwise we have a bug!
407          */
408         if ((rqstp->rq_res.len) >  rqstp->rq_reserved)
409                 printk(KERN_ERR "RPC request reserved %d but used %d\n",
410                        rqstp->rq_reserved,
411                        rqstp->rq_res.len);
412
413         rqstp->rq_res.head[0].iov_len = 0;
414         svc_reserve(rqstp, 0);
415         rqstp->rq_sock = NULL;
416
417         svc_sock_put(svsk);
418 }
419
420 /*
421  * External function to wake up a server waiting for data
422  * This really only makes sense for services like lockd
423  * which have exactly one thread anyway.
424  */
425 void
426 svc_wake_up(struct svc_serv *serv)
427 {
428         struct svc_rqst *rqstp;
429         unsigned int i;
430         struct svc_pool *pool;
431
432         for (i = 0; i < serv->sv_nrpools; i++) {
433                 pool = &serv->sv_pools[i];
434
435                 spin_lock_bh(&pool->sp_lock);
436                 if (!list_empty(&pool->sp_threads)) {
437                         rqstp = list_entry(pool->sp_threads.next,
438                                            struct svc_rqst,
439                                            rq_list);
440                         dprintk("svc: daemon %p woken up.\n", rqstp);
441                         /*
442                         svc_thread_dequeue(pool, rqstp);
443                         rqstp->rq_sock = NULL;
444                          */
445                         wake_up(&rqstp->rq_wait);
446                 }
447                 spin_unlock_bh(&pool->sp_lock);
448         }
449 }
450
451 union svc_pktinfo_u {
452         struct in_pktinfo pkti;
453         struct in6_pktinfo pkti6;
454 };
455
456 static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
457 {
458         switch (rqstp->rq_sock->sk_sk->sk_family) {
459         case AF_INET: {
460                         struct in_pktinfo *pki = CMSG_DATA(cmh);
461
462                         cmh->cmsg_level = SOL_IP;
463                         cmh->cmsg_type = IP_PKTINFO;
464                         pki->ipi_ifindex = 0;
465                         pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
466                         cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
467                 }
468                 break;
469
470         case AF_INET6: {
471                         struct in6_pktinfo *pki = CMSG_DATA(cmh);
472
473                         cmh->cmsg_level = SOL_IPV6;
474                         cmh->cmsg_type = IPV6_PKTINFO;
475                         pki->ipi6_ifindex = 0;
476                         ipv6_addr_copy(&pki->ipi6_addr,
477                                         &rqstp->rq_daddr.addr6);
478                         cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
479                 }
480                 break;
481         }
482         return;
483 }
484
485 /*
486  * Generic sendto routine
487  */
488 static int
489 svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
490 {
491         struct svc_sock *svsk = rqstp->rq_sock;
492         struct socket   *sock = svsk->sk_sock;
493         int             slen;
494         char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
495         struct cmsghdr *cmh = (struct cmsghdr *)buffer;
496         int             len = 0;
497         int             result;
498         int             size;
499         struct page     **ppage = xdr->pages;
500         size_t          base = xdr->page_base;
501         unsigned int    pglen = xdr->page_len;
502         unsigned int    flags = MSG_MORE;
503         char            buf[RPC_MAX_ADDRBUFLEN];
504
505         slen = xdr->len;
506
507         if (rqstp->rq_prot == IPPROTO_UDP) {
508                 struct msghdr msg = {
509                         .msg_name       = &rqstp->rq_addr,
510                         .msg_namelen    = rqstp->rq_addrlen,
511                         .msg_control    = cmh,
512                         .msg_controllen = sizeof(buffer),
513                         .msg_flags      = MSG_MORE,
514                 };
515
516                 svc_set_cmsg_data(rqstp, cmh);
517
518                 if (sock_sendmsg(sock, &msg, 0) < 0)
519                         goto out;
520         }
521
522         /* send head */
523         if (slen == xdr->head[0].iov_len)
524                 flags = 0;
525         len = kernel_sendpage(sock, rqstp->rq_respages[0], 0,
526                                   xdr->head[0].iov_len, flags);
527         if (len != xdr->head[0].iov_len)
528                 goto out;
529         slen -= xdr->head[0].iov_len;
530         if (slen == 0)
531                 goto out;
532
533         /* send page data */
534         size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
535         while (pglen > 0) {
536                 if (slen == size)
537                         flags = 0;
538                 result = kernel_sendpage(sock, *ppage, base, size, flags);
539                 if (result > 0)
540                         len += result;
541                 if (result != size)
542                         goto out;
543                 slen -= size;
544                 pglen -= size;
545                 size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
546                 base = 0;
547                 ppage++;
548         }
549         /* send tail */
550         if (xdr->tail[0].iov_len) {
551                 result = kernel_sendpage(sock, rqstp->rq_respages[0],
552                                              ((unsigned long)xdr->tail[0].iov_base)
553                                                 & (PAGE_SIZE-1),
554                                              xdr->tail[0].iov_len, 0);
555
556                 if (result > 0)
557                         len += result;
558         }
559 out:
560         dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
561                 rqstp->rq_sock, xdr->head[0].iov_base, xdr->head[0].iov_len,
562                 xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
563
564         return len;
565 }
566
567 /*
568  * Report socket names for nfsdfs
569  */
570 static int one_sock_name(char *buf, struct svc_sock *svsk)
571 {
572         int len;
573
574         switch(svsk->sk_sk->sk_family) {
575         case AF_INET:
576                 len = sprintf(buf, "ipv4 %s %u.%u.%u.%u %d\n",
577                               svsk->sk_sk->sk_protocol==IPPROTO_UDP?
578                               "udp" : "tcp",
579                               NIPQUAD(inet_sk(svsk->sk_sk)->rcv_saddr),
580                               inet_sk(svsk->sk_sk)->num);
581                 break;
582         default:
583                 len = sprintf(buf, "*unknown-%d*\n",
584                                svsk->sk_sk->sk_family);
585         }
586         return len;
587 }
588
589 int
590 svc_sock_names(char *buf, struct svc_serv *serv, char *toclose)
591 {
592         struct svc_sock *svsk, *closesk = NULL;
593         int len = 0;
594
595         if (!serv)
596                 return 0;
597         spin_lock_bh(&serv->sv_lock);
598         list_for_each_entry(svsk, &serv->sv_permsocks, sk_list) {
599                 int onelen = one_sock_name(buf+len, svsk);
600                 if (toclose && strcmp(toclose, buf+len) == 0)
601                         closesk = svsk;
602                 else
603                         len += onelen;
604         }
605         spin_unlock_bh(&serv->sv_lock);
606         if (closesk)
607                 /* Should unregister with portmap, but you cannot
608                  * unregister just one protocol...
609                  */
610                 svc_close_socket(closesk);
611         else if (toclose)
612                 return -ENOENT;
613         return len;
614 }
615 EXPORT_SYMBOL(svc_sock_names);
616
617 /*
618  * Check input queue length
619  */
620 static int
621 svc_recv_available(struct svc_sock *svsk)
622 {
623         struct socket   *sock = svsk->sk_sock;
624         int             avail, err;
625
626         err = kernel_sock_ioctl(sock, TIOCINQ, (unsigned long) &avail);
627
628         return (err >= 0)? avail : err;
629 }
630
631 /*
632  * Generic recvfrom routine.
633  */
634 static int
635 svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
636 {
637         struct svc_sock *svsk = rqstp->rq_sock;
638         struct msghdr msg = {
639                 .msg_flags      = MSG_DONTWAIT,
640         };
641         int len;
642
643         len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
644                                 msg.msg_flags);
645
646         /* sock_recvmsg doesn't fill in the name/namelen, so we must..
647          */
648         memcpy(&rqstp->rq_addr, &svsk->sk_remote, svsk->sk_remotelen);
649         rqstp->rq_addrlen = svsk->sk_remotelen;
650
651         dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
652                 svsk, iov[0].iov_base, iov[0].iov_len, len);
653
654         return len;
655 }
656
657 /*
658  * Set socket snd and rcv buffer lengths
659  */
660 static inline void
661 svc_sock_setbufsize(struct socket *sock, unsigned int snd, unsigned int rcv)
662 {
663 #if 0
664         mm_segment_t    oldfs;
665         oldfs = get_fs(); set_fs(KERNEL_DS);
666         sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
667                         (char*)&snd, sizeof(snd));
668         sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
669                         (char*)&rcv, sizeof(rcv));
670 #else
671         /* sock_setsockopt limits use to sysctl_?mem_max,
672          * which isn't acceptable.  Until that is made conditional
673          * on not having CAP_SYS_RESOURCE or similar, we go direct...
674          * DaveM said I could!
675          */
676         lock_sock(sock->sk);
677         sock->sk->sk_sndbuf = snd * 2;
678         sock->sk->sk_rcvbuf = rcv * 2;
679         sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
680         release_sock(sock->sk);
681 #endif
682 }
683 /*
684  * INET callback when data has been received on the socket.
685  */
686 static void
687 svc_udp_data_ready(struct sock *sk, int count)
688 {
689         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
690
691         if (svsk) {
692                 dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
693                         svsk, sk, count, test_bit(SK_BUSY, &svsk->sk_flags));
694                 set_bit(SK_DATA, &svsk->sk_flags);
695                 svc_sock_enqueue(svsk);
696         }
697         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
698                 wake_up_interruptible(sk->sk_sleep);
699 }
700
701 /*
702  * INET callback when space is newly available on the socket.
703  */
704 static void
705 svc_write_space(struct sock *sk)
706 {
707         struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
708
709         if (svsk) {
710                 dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
711                         svsk, sk, test_bit(SK_BUSY, &svsk->sk_flags));
712                 svc_sock_enqueue(svsk);
713         }
714
715         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) {
716                 dprintk("RPC svc_write_space: someone sleeping on %p\n",
717                        svsk);
718                 wake_up_interruptible(sk->sk_sleep);
719         }
720 }
721
722 static inline void svc_udp_get_dest_address(struct svc_rqst *rqstp,
723                                             struct cmsghdr *cmh)
724 {
725         switch (rqstp->rq_sock->sk_sk->sk_family) {
726         case AF_INET: {
727                 struct in_pktinfo *pki = CMSG_DATA(cmh);
728                 rqstp->rq_daddr.addr.s_addr = pki->ipi_spec_dst.s_addr;
729                 break;
730                 }
731         case AF_INET6: {
732                 struct in6_pktinfo *pki = CMSG_DATA(cmh);
733                 ipv6_addr_copy(&rqstp->rq_daddr.addr6, &pki->ipi6_addr);
734                 break;
735                 }
736         }
737 }
738
739 /*
740  * Receive a datagram from a UDP socket.
741  */
742 static int
743 svc_udp_recvfrom(struct svc_rqst *rqstp)
744 {
745         struct svc_sock *svsk = rqstp->rq_sock;
746         struct svc_serv *serv = svsk->sk_server;
747         struct sk_buff  *skb;
748         char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
749         struct cmsghdr *cmh = (struct cmsghdr *)buffer;
750         int             err, len;
751         struct msghdr msg = {
752                 .msg_name = svc_addr(rqstp),
753                 .msg_control = cmh,
754                 .msg_controllen = sizeof(buffer),
755                 .msg_flags = MSG_DONTWAIT,
756         };
757
758         if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
759             /* udp sockets need large rcvbuf as all pending
760              * requests are still in that buffer.  sndbuf must
761              * also be large enough that there is enough space
762              * for one reply per thread.  We count all threads
763              * rather than threads in a particular pool, which
764              * provides an upper bound on the number of threads
765              * which will access the socket.
766              */
767             svc_sock_setbufsize(svsk->sk_sock,
768                                 (serv->sv_nrthreads+3) * serv->sv_max_mesg,
769                                 (serv->sv_nrthreads+3) * serv->sv_max_mesg);
770
771         if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
772                 svc_sock_received(svsk);
773                 return svc_deferred_recv(rqstp);
774         }
775
776         if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
777                 svc_delete_socket(svsk);
778                 return 0;
779         }
780
781         clear_bit(SK_DATA, &svsk->sk_flags);
782         while ((err == kernel_recvmsg(svsk->sk_sock, &msg, NULL,
783                                       0, 0, MSG_PEEK | MSG_DONTWAIT)) < 0 ||
784                (skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
785                 if (err == -EAGAIN) {
786                         svc_sock_received(svsk);
787                         return err;
788                 }
789                 /* possibly an icmp error */
790                 dprintk("svc: recvfrom returned error %d\n", -err);
791         }
792         rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
793         if (skb->tstamp.off_sec == 0) {
794                 struct timeval tv;
795
796                 tv.tv_sec = xtime.tv_sec;
797                 tv.tv_usec = xtime.tv_nsec / NSEC_PER_USEC;
798                 skb_set_timestamp(skb, &tv);
799                 /* Don't enable netstamp, sunrpc doesn't
800                    need that much accuracy */
801         }
802         skb_get_timestamp(skb, &svsk->sk_sk->sk_stamp);
803         set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
804
805         /*
806          * Maybe more packets - kick another thread ASAP.
807          */
808         svc_sock_received(svsk);
809
810         len  = skb->len - sizeof(struct udphdr);
811         rqstp->rq_arg.len = len;
812
813         rqstp->rq_prot = IPPROTO_UDP;
814
815         if (cmh->cmsg_level != IPPROTO_IP ||
816             cmh->cmsg_type != IP_PKTINFO) {
817                 if (net_ratelimit())
818                         printk("rpcsvc: received unknown control message:"
819                                "%d/%d\n",
820                                cmh->cmsg_level, cmh->cmsg_type);
821                 skb_free_datagram(svsk->sk_sk, skb);
822                 return 0;
823         }
824         svc_udp_get_dest_address(rqstp, cmh);
825
826         if (skb_is_nonlinear(skb)) {
827                 /* we have to copy */
828                 local_bh_disable();
829                 if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
830                         local_bh_enable();
831                         /* checksum error */
832                         skb_free_datagram(svsk->sk_sk, skb);
833                         return 0;
834                 }
835                 local_bh_enable();
836                 skb_free_datagram(svsk->sk_sk, skb);
837         } else {
838                 /* we can use it in-place */
839                 rqstp->rq_arg.head[0].iov_base = skb->data + sizeof(struct udphdr);
840                 rqstp->rq_arg.head[0].iov_len = len;
841                 if (skb_checksum_complete(skb)) {
842                         skb_free_datagram(svsk->sk_sk, skb);
843                         return 0;
844                 }
845                 rqstp->rq_skbuff = skb;
846         }
847
848         rqstp->rq_arg.page_base = 0;
849         if (len <= rqstp->rq_arg.head[0].iov_len) {
850                 rqstp->rq_arg.head[0].iov_len = len;
851                 rqstp->rq_arg.page_len = 0;
852                 rqstp->rq_respages = rqstp->rq_pages+1;
853         } else {
854                 rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
855                 rqstp->rq_respages = rqstp->rq_pages + 1 +
856                         (rqstp->rq_arg.page_len + PAGE_SIZE - 1)/ PAGE_SIZE;
857         }
858
859         if (serv->sv_stats)
860                 serv->sv_stats->netudpcnt++;
861
862         return len;
863 }
864
865 static int
866 svc_udp_sendto(struct svc_rqst *rqstp)
867 {
868         int             error;
869
870         error = svc_sendto(rqstp, &rqstp->rq_res);
871         if (error == -ECONNREFUSED)
872                 /* ICMP error on earlier request. */
873                 error = svc_sendto(rqstp, &rqstp->rq_res);
874
875         return error;
876 }
877
878 static void
879 svc_udp_init(struct svc_sock *svsk)
880 {
881         int one = 1;
882         mm_segment_t oldfs;
883
884         svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
885         svsk->sk_sk->sk_write_space = svc_write_space;
886         svsk->sk_recvfrom = svc_udp_recvfrom;
887         svsk->sk_sendto = svc_udp_sendto;
888
889         /* initialise setting must have enough space to
890          * receive and respond to one request.
891          * svc_udp_recvfrom will re-adjust if necessary
892          */
893         svc_sock_setbufsize(svsk->sk_sock,
894                             3 * svsk->sk_server->sv_max_mesg,
895                             3 * svsk->sk_server->sv_max_mesg);
896
897         set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */
898         set_bit(SK_CHNGBUF, &svsk->sk_flags);
899
900         oldfs = get_fs();
901         set_fs(KERNEL_DS);
902         /* make sure we get destination address info */
903         svsk->sk_sock->ops->setsockopt(svsk->sk_sock, IPPROTO_IP, IP_PKTINFO,
904                                        (char __user *)&one, sizeof(one));
905         set_fs(oldfs);
906 }
907
908 /*
909  * A data_ready event on a listening socket means there's a connection
910  * pending. Do not use state_change as a substitute for it.
911  */
912 static void
913 svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
914 {
915         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
916
917         dprintk("svc: socket %p TCP (listen) state change %d\n",
918                 sk, sk->sk_state);
919
920         /*
921          * This callback may called twice when a new connection
922          * is established as a child socket inherits everything
923          * from a parent LISTEN socket.
924          * 1) data_ready method of the parent socket will be called
925          *    when one of child sockets become ESTABLISHED.
926          * 2) data_ready method of the child socket may be called
927          *    when it receives data before the socket is accepted.
928          * In case of 2, we should ignore it silently.
929          */
930         if (sk->sk_state == TCP_LISTEN) {
931                 if (svsk) {
932                         set_bit(SK_CONN, &svsk->sk_flags);
933                         svc_sock_enqueue(svsk);
934                 } else
935                         printk("svc: socket %p: no user data\n", sk);
936         }
937
938         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
939                 wake_up_interruptible_all(sk->sk_sleep);
940 }
941
942 /*
943  * A state change on a connected socket means it's dying or dead.
944  */
945 static void
946 svc_tcp_state_change(struct sock *sk)
947 {
948         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
949
950         dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
951                 sk, sk->sk_state, sk->sk_user_data);
952
953         if (!svsk)
954                 printk("svc: socket %p: no user data\n", sk);
955         else {
956                 set_bit(SK_CLOSE, &svsk->sk_flags);
957                 svc_sock_enqueue(svsk);
958         }
959         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
960                 wake_up_interruptible_all(sk->sk_sleep);
961 }
962
963 static void
964 svc_tcp_data_ready(struct sock *sk, int count)
965 {
966         struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
967
968         dprintk("svc: socket %p TCP data ready (svsk %p)\n",
969                 sk, sk->sk_user_data);
970         if (svsk) {
971                 set_bit(SK_DATA, &svsk->sk_flags);
972                 svc_sock_enqueue(svsk);
973         }
974         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
975                 wake_up_interruptible(sk->sk_sleep);
976 }
977
978 static inline int svc_port_is_privileged(struct sockaddr *sin)
979 {
980         switch (sin->sa_family) {
981         case AF_INET:
982                 return ntohs(((struct sockaddr_in *)sin)->sin_port)
983                         < PROT_SOCK;
984         case AF_INET6:
985                 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
986                         < PROT_SOCK;
987         default:
988                 return 0;
989         }
990 }
991
992 /*
993  * Accept a TCP connection
994  */
995 static void
996 svc_tcp_accept(struct svc_sock *svsk)
997 {
998         struct sockaddr_storage addr;
999         struct sockaddr *sin = (struct sockaddr *) &addr;
1000         struct svc_serv *serv = svsk->sk_server;
1001         struct socket   *sock = svsk->sk_sock;
1002         struct socket   *newsock;
1003         struct svc_sock *newsvsk;
1004         int             err, slen;
1005         char            buf[RPC_MAX_ADDRBUFLEN];
1006
1007         dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
1008         if (!sock)
1009                 return;
1010
1011         clear_bit(SK_CONN, &svsk->sk_flags);
1012         err = kernel_accept(sock, &newsock, O_NONBLOCK);
1013         if (err < 0) {
1014                 if (err == -ENOMEM)
1015                         printk(KERN_WARNING "%s: no more sockets!\n",
1016                                serv->sv_name);
1017                 else if (err != -EAGAIN && net_ratelimit())
1018                         printk(KERN_WARNING "%s: accept failed (err %d)!\n",
1019                                    serv->sv_name, -err);
1020                 return;
1021         }
1022
1023         set_bit(SK_CONN, &svsk->sk_flags);
1024         svc_sock_enqueue(svsk);
1025
1026         err = kernel_getpeername(newsock, sin, &slen);
1027         if (err < 0) {
1028                 if (net_ratelimit())
1029                         printk(KERN_WARNING "%s: peername failed (err %d)!\n",
1030                                    serv->sv_name, -err);
1031                 goto failed;            /* aborted connection or whatever */
1032         }
1033
1034         /* Ideally, we would want to reject connections from unauthorized
1035          * hosts here, but when we get encryption, the IP of the host won't
1036          * tell us anything.  For now just warn about unpriv connections.
1037          */
1038         if (!svc_port_is_privileged(sin)) {
1039                 dprintk(KERN_WARNING
1040                         "%s: connect from unprivileged port: %s\n",
1041                         serv->sv_name,
1042                         __svc_print_addr(sin, buf, sizeof(buf)));
1043         }
1044         dprintk("%s: connect from %s\n", serv->sv_name,
1045                 __svc_print_addr(sin, buf, sizeof(buf)));
1046
1047         /* make sure that a write doesn't block forever when
1048          * low on memory
1049          */
1050         newsock->sk->sk_sndtimeo = HZ*30;
1051
1052         if (!(newsvsk = svc_setup_socket(serv, newsock, &err,
1053                                  (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY))))
1054                 goto failed;
1055         memcpy(&newsvsk->sk_remote, sin, slen);
1056         newsvsk->sk_remotelen = slen;
1057
1058         svc_sock_received(newsvsk);
1059
1060         /* make sure that we don't have too many active connections.
1061          * If we have, something must be dropped.
1062          *
1063          * There's no point in trying to do random drop here for
1064          * DoS prevention. The NFS clients does 1 reconnect in 15
1065          * seconds. An attacker can easily beat that.
1066          *
1067          * The only somewhat efficient mechanism would be if drop
1068          * old connections from the same IP first. But right now
1069          * we don't even record the client IP in svc_sock.
1070          */
1071         if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
1072                 struct svc_sock *svsk = NULL;
1073                 spin_lock_bh(&serv->sv_lock);
1074                 if (!list_empty(&serv->sv_tempsocks)) {
1075                         if (net_ratelimit()) {
1076                                 /* Try to help the admin */
1077                                 printk(KERN_NOTICE "%s: too many open TCP "
1078                                         "sockets, consider increasing the "
1079                                         "number of nfsd threads\n",
1080                                                    serv->sv_name);
1081                                 printk(KERN_NOTICE
1082                                        "%s: last TCP connect from %s\n",
1083                                        serv->sv_name, buf);
1084                         }
1085                         /*
1086                          * Always select the oldest socket. It's not fair,
1087                          * but so is life
1088                          */
1089                         svsk = list_entry(serv->sv_tempsocks.prev,
1090                                           struct svc_sock,
1091                                           sk_list);
1092                         set_bit(SK_CLOSE, &svsk->sk_flags);
1093                         atomic_inc(&svsk->sk_inuse);
1094                 }
1095                 spin_unlock_bh(&serv->sv_lock);
1096
1097                 if (svsk) {
1098                         svc_sock_enqueue(svsk);
1099                         svc_sock_put(svsk);
1100                 }
1101
1102         }
1103
1104         if (serv->sv_stats)
1105                 serv->sv_stats->nettcpconn++;
1106
1107         return;
1108
1109 failed:
1110         sock_release(newsock);
1111         return;
1112 }
1113
1114 /*
1115  * Receive data from a TCP socket.
1116  */
1117 static int
1118 svc_tcp_recvfrom(struct svc_rqst *rqstp)
1119 {
1120         struct svc_sock *svsk = rqstp->rq_sock;
1121         struct svc_serv *serv = svsk->sk_server;
1122         int             len;
1123         struct kvec *vec;
1124         int pnum, vlen;
1125
1126         dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
1127                 svsk, test_bit(SK_DATA, &svsk->sk_flags),
1128                 test_bit(SK_CONN, &svsk->sk_flags),
1129                 test_bit(SK_CLOSE, &svsk->sk_flags));
1130
1131         if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
1132                 svc_sock_received(svsk);
1133                 return svc_deferred_recv(rqstp);
1134         }
1135
1136         if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
1137                 svc_delete_socket(svsk);
1138                 return 0;
1139         }
1140
1141         if (svsk->sk_sk->sk_state == TCP_LISTEN) {
1142                 svc_tcp_accept(svsk);
1143                 svc_sock_received(svsk);
1144                 return 0;
1145         }
1146
1147         if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
1148                 /* sndbuf needs to have room for one request
1149                  * per thread, otherwise we can stall even when the
1150                  * network isn't a bottleneck.
1151                  *
1152                  * We count all threads rather than threads in a
1153                  * particular pool, which provides an upper bound
1154                  * on the number of threads which will access the socket.
1155                  *
1156                  * rcvbuf just needs to be able to hold a few requests.
1157                  * Normally they will be removed from the queue
1158                  * as soon a a complete request arrives.
1159                  */
1160                 svc_sock_setbufsize(svsk->sk_sock,
1161                                     (serv->sv_nrthreads+3) * serv->sv_max_mesg,
1162                                     3 * serv->sv_max_mesg);
1163
1164         clear_bit(SK_DATA, &svsk->sk_flags);
1165
1166         /* Receive data. If we haven't got the record length yet, get
1167          * the next four bytes. Otherwise try to gobble up as much as
1168          * possible up to the complete record length.
1169          */
1170         if (svsk->sk_tcplen < 4) {
1171                 unsigned long   want = 4 - svsk->sk_tcplen;
1172                 struct kvec     iov;
1173
1174                 iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
1175                 iov.iov_len  = want;
1176                 if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
1177                         goto error;
1178                 svsk->sk_tcplen += len;
1179
1180                 if (len < want) {
1181                         dprintk("svc: short recvfrom while reading record length (%d of %lu)\n",
1182                                 len, want);
1183                         svc_sock_received(svsk);
1184                         return -EAGAIN; /* record header not complete */
1185                 }
1186
1187                 svsk->sk_reclen = ntohl(svsk->sk_reclen);
1188                 if (!(svsk->sk_reclen & 0x80000000)) {
1189                         /* FIXME: technically, a record can be fragmented,
1190                          *  and non-terminal fragments will not have the top
1191                          *  bit set in the fragment length header.
1192                          *  But apparently no known nfs clients send fragmented
1193                          *  records. */
1194                         if (net_ratelimit())
1195                                 printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx"
1196                                        " (non-terminal)\n",
1197                                        (unsigned long) svsk->sk_reclen);
1198                         goto err_delete;
1199                 }
1200                 svsk->sk_reclen &= 0x7fffffff;
1201                 dprintk("svc: TCP record, %d bytes\n", svsk->sk_reclen);
1202                 if (svsk->sk_reclen > serv->sv_max_mesg) {
1203                         if (net_ratelimit())
1204                                 printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx"
1205                                        " (large)\n",
1206                                        (unsigned long) svsk->sk_reclen);
1207                         goto err_delete;
1208                 }
1209         }
1210
1211         /* Check whether enough data is available */
1212         len = svc_recv_available(svsk);
1213         if (len < 0)
1214                 goto error;
1215
1216         if (len < svsk->sk_reclen) {
1217                 dprintk("svc: incomplete TCP record (%d of %d)\n",
1218                         len, svsk->sk_reclen);
1219                 svc_sock_received(svsk);
1220                 return -EAGAIN; /* record not complete */
1221         }
1222         len = svsk->sk_reclen;
1223         set_bit(SK_DATA, &svsk->sk_flags);
1224
1225         vec = rqstp->rq_vec;
1226         vec[0] = rqstp->rq_arg.head[0];
1227         vlen = PAGE_SIZE;
1228         pnum = 1;
1229         while (vlen < len) {
1230                 vec[pnum].iov_base = page_address(rqstp->rq_pages[pnum]);
1231                 vec[pnum].iov_len = PAGE_SIZE;
1232                 pnum++;
1233                 vlen += PAGE_SIZE;
1234         }
1235         rqstp->rq_respages = &rqstp->rq_pages[pnum];
1236
1237         /* Now receive data */
1238         len = svc_recvfrom(rqstp, vec, pnum, len);
1239         if (len < 0)
1240                 goto error;
1241
1242         dprintk("svc: TCP complete record (%d bytes)\n", len);
1243         rqstp->rq_arg.len = len;
1244         rqstp->rq_arg.page_base = 0;
1245         if (len <= rqstp->rq_arg.head[0].iov_len) {
1246                 rqstp->rq_arg.head[0].iov_len = len;
1247                 rqstp->rq_arg.page_len = 0;
1248         } else {
1249                 rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
1250         }
1251
1252         rqstp->rq_skbuff      = NULL;
1253         rqstp->rq_prot        = IPPROTO_TCP;
1254
1255         /* Reset TCP read info */
1256         svsk->sk_reclen = 0;
1257         svsk->sk_tcplen = 0;
1258
1259         svc_sock_received(svsk);
1260         if (serv->sv_stats)
1261                 serv->sv_stats->nettcpcnt++;
1262
1263         return len;
1264
1265  err_delete:
1266         svc_delete_socket(svsk);
1267         return -EAGAIN;
1268
1269  error:
1270         if (len == -EAGAIN) {
1271                 dprintk("RPC: TCP recvfrom got EAGAIN\n");
1272                 svc_sock_received(svsk);
1273         } else {
1274                 printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
1275                                         svsk->sk_server->sv_name, -len);
1276                 goto err_delete;
1277         }
1278
1279         return len;
1280 }
1281
1282 /*
1283  * Send out data on TCP socket.
1284  */
1285 static int
1286 svc_tcp_sendto(struct svc_rqst *rqstp)
1287 {
1288         struct xdr_buf  *xbufp = &rqstp->rq_res;
1289         int sent;
1290         __be32 reclen;
1291
1292         /* Set up the first element of the reply kvec.
1293          * Any other kvecs that may be in use have been taken
1294          * care of by the server implementation itself.
1295          */
1296         reclen = htonl(0x80000000|((xbufp->len ) - 4));
1297         memcpy(xbufp->head[0].iov_base, &reclen, 4);
1298
1299         if (test_bit(SK_DEAD, &rqstp->rq_sock->sk_flags))
1300                 return -ENOTCONN;
1301
1302         sent = svc_sendto(rqstp, &rqstp->rq_res);
1303         if (sent != xbufp->len) {
1304                 printk(KERN_NOTICE "rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
1305                        rqstp->rq_sock->sk_server->sv_name,
1306                        (sent<0)?"got error":"sent only",
1307                        sent, xbufp->len);
1308                 set_bit(SK_CLOSE, &rqstp->rq_sock->sk_flags);
1309                 svc_sock_enqueue(rqstp->rq_sock);
1310                 sent = -EAGAIN;
1311         }
1312         return sent;
1313 }
1314
1315 static void
1316 svc_tcp_init(struct svc_sock *svsk)
1317 {
1318         struct sock     *sk = svsk->sk_sk;
1319         struct tcp_sock *tp = tcp_sk(sk);
1320
1321         svsk->sk_recvfrom = svc_tcp_recvfrom;
1322         svsk->sk_sendto = svc_tcp_sendto;
1323
1324         if (sk->sk_state == TCP_LISTEN) {
1325                 dprintk("setting up TCP socket for listening\n");
1326                 sk->sk_data_ready = svc_tcp_listen_data_ready;
1327                 set_bit(SK_CONN, &svsk->sk_flags);
1328         } else {
1329                 dprintk("setting up TCP socket for reading\n");
1330                 sk->sk_state_change = svc_tcp_state_change;
1331                 sk->sk_data_ready = svc_tcp_data_ready;
1332                 sk->sk_write_space = svc_write_space;
1333
1334                 svsk->sk_reclen = 0;
1335                 svsk->sk_tcplen = 0;
1336
1337                 tp->nonagle = 1;        /* disable Nagle's algorithm */
1338
1339                 /* initialise setting must have enough space to
1340                  * receive and respond to one request.
1341                  * svc_tcp_recvfrom will re-adjust if necessary
1342                  */
1343                 svc_sock_setbufsize(svsk->sk_sock,
1344                                     3 * svsk->sk_server->sv_max_mesg,
1345                                     3 * svsk->sk_server->sv_max_mesg);
1346
1347                 set_bit(SK_CHNGBUF, &svsk->sk_flags);
1348                 set_bit(SK_DATA, &svsk->sk_flags);
1349                 if (sk->sk_state != TCP_ESTABLISHED)
1350                         set_bit(SK_CLOSE, &svsk->sk_flags);
1351         }
1352 }
1353
1354 void
1355 svc_sock_update_bufs(struct svc_serv *serv)
1356 {
1357         /*
1358          * The number of server threads has changed. Update
1359          * rcvbuf and sndbuf accordingly on all sockets
1360          */
1361         struct list_head *le;
1362
1363         spin_lock_bh(&serv->sv_lock);
1364         list_for_each(le, &serv->sv_permsocks) {
1365                 struct svc_sock *svsk =
1366                         list_entry(le, struct svc_sock, sk_list);
1367                 set_bit(SK_CHNGBUF, &svsk->sk_flags);
1368         }
1369         list_for_each(le, &serv->sv_tempsocks) {
1370                 struct svc_sock *svsk =
1371                         list_entry(le, struct svc_sock, sk_list);
1372                 set_bit(SK_CHNGBUF, &svsk->sk_flags);
1373         }
1374         spin_unlock_bh(&serv->sv_lock);
1375 }
1376
1377 /*
1378  * Receive the next request on any socket.  This code is carefully
1379  * organised not to touch any cachelines in the shared svc_serv
1380  * structure, only cachelines in the local svc_pool.
1381  */
1382 int
1383 svc_recv(struct svc_rqst *rqstp, long timeout)
1384 {
1385         struct svc_sock         *svsk = NULL;
1386         struct svc_serv         *serv = rqstp->rq_server;
1387         struct svc_pool         *pool = rqstp->rq_pool;
1388         int                     len, i;
1389         int                     pages;
1390         struct xdr_buf          *arg;
1391         DECLARE_WAITQUEUE(wait, current);
1392
1393         dprintk("svc: server %p waiting for data (to = %ld)\n",
1394                 rqstp, timeout);
1395
1396         if (rqstp->rq_sock)
1397                 printk(KERN_ERR
1398                         "svc_recv: service %p, socket not NULL!\n",
1399                          rqstp);
1400         if (waitqueue_active(&rqstp->rq_wait))
1401                 printk(KERN_ERR
1402                         "svc_recv: service %p, wait queue active!\n",
1403                          rqstp);
1404
1405
1406         /* now allocate needed pages.  If we get a failure, sleep briefly */
1407         pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
1408         for (i=0; i < pages ; i++)
1409                 while (rqstp->rq_pages[i] == NULL) {
1410                         struct page *p = alloc_page(GFP_KERNEL);
1411                         if (!p)
1412                                 schedule_timeout_uninterruptible(msecs_to_jiffies(500));
1413                         rqstp->rq_pages[i] = p;
1414                 }
1415         rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
1416         BUG_ON(pages >= RPCSVC_MAXPAGES);
1417
1418         /* Make arg->head point to first page and arg->pages point to rest */
1419         arg = &rqstp->rq_arg;
1420         arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
1421         arg->head[0].iov_len = PAGE_SIZE;
1422         arg->pages = rqstp->rq_pages + 1;
1423         arg->page_base = 0;
1424         /* save at least one page for response */
1425         arg->page_len = (pages-2)*PAGE_SIZE;
1426         arg->len = (pages-1)*PAGE_SIZE;
1427         arg->tail[0].iov_len = 0;
1428
1429         try_to_freeze();
1430         cond_resched();
1431         if (signalled())
1432                 return -EINTR;
1433
1434         spin_lock_bh(&pool->sp_lock);
1435         if ((svsk = svc_sock_dequeue(pool)) != NULL) {
1436                 rqstp->rq_sock = svsk;
1437                 atomic_inc(&svsk->sk_inuse);
1438                 rqstp->rq_reserved = serv->sv_max_mesg;
1439                 atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
1440         } else {
1441                 /* No data pending. Go to sleep */
1442                 svc_thread_enqueue(pool, rqstp);
1443
1444                 /*
1445                  * We have to be able to interrupt this wait
1446                  * to bring down the daemons ...
1447                  */
1448                 set_current_state(TASK_INTERRUPTIBLE);
1449                 add_wait_queue(&rqstp->rq_wait, &wait);
1450                 spin_unlock_bh(&pool->sp_lock);
1451
1452                 schedule_timeout(timeout);
1453
1454                 try_to_freeze();
1455
1456                 spin_lock_bh(&pool->sp_lock);
1457                 remove_wait_queue(&rqstp->rq_wait, &wait);
1458
1459                 if (!(svsk = rqstp->rq_sock)) {
1460                         svc_thread_dequeue(pool, rqstp);
1461                         spin_unlock_bh(&pool->sp_lock);
1462                         dprintk("svc: server %p, no data yet\n", rqstp);
1463                         return signalled()? -EINTR : -EAGAIN;
1464                 }
1465         }
1466         spin_unlock_bh(&pool->sp_lock);
1467
1468         dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",
1469                  rqstp, pool->sp_id, svsk, atomic_read(&svsk->sk_inuse));
1470         len = svsk->sk_recvfrom(rqstp);
1471         dprintk("svc: got len=%d\n", len);
1472
1473         /* No data, incomplete (TCP) read, or accept() */
1474         if (len == 0 || len == -EAGAIN) {
1475                 rqstp->rq_res.len = 0;
1476                 svc_sock_release(rqstp);
1477                 return -EAGAIN;
1478         }
1479         svsk->sk_lastrecv = get_seconds();
1480         clear_bit(SK_OLD, &svsk->sk_flags);
1481
1482         rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
1483         rqstp->rq_chandle.defer = svc_defer;
1484
1485         if (serv->sv_stats)
1486                 serv->sv_stats->netcnt++;
1487         return len;
1488 }
1489
1490 /*
1491  * Drop request
1492  */
1493 void
1494 svc_drop(struct svc_rqst *rqstp)
1495 {
1496         dprintk("svc: socket %p dropped request\n", rqstp->rq_sock);
1497         svc_sock_release(rqstp);
1498 }
1499
1500 /*
1501  * Return reply to client.
1502  */
1503 int
1504 svc_send(struct svc_rqst *rqstp)
1505 {
1506         struct svc_sock *svsk;
1507         int             len;
1508         struct xdr_buf  *xb;
1509
1510         if ((svsk = rqstp->rq_sock) == NULL) {
1511                 printk(KERN_WARNING "NULL socket pointer in %s:%d\n",
1512                                 __FILE__, __LINE__);
1513                 return -EFAULT;
1514         }
1515
1516         /* release the receive skb before sending the reply */
1517         svc_release_skb(rqstp);
1518
1519         /* calculate over-all length */
1520         xb = & rqstp->rq_res;
1521         xb->len = xb->head[0].iov_len +
1522                 xb->page_len +
1523                 xb->tail[0].iov_len;
1524
1525         /* Grab svsk->sk_mutex to serialize outgoing data. */
1526         mutex_lock(&svsk->sk_mutex);
1527         if (test_bit(SK_DEAD, &svsk->sk_flags))
1528                 len = -ENOTCONN;
1529         else
1530                 len = svsk->sk_sendto(rqstp);
1531         mutex_unlock(&svsk->sk_mutex);
1532         svc_sock_release(rqstp);
1533
1534         if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
1535                 return 0;
1536         return len;
1537 }
1538
1539 /*
1540  * Timer function to close old temporary sockets, using
1541  * a mark-and-sweep algorithm.
1542  */
1543 static void
1544 svc_age_temp_sockets(unsigned long closure)
1545 {
1546         struct svc_serv *serv = (struct svc_serv *)closure;
1547         struct svc_sock *svsk;
1548         struct list_head *le, *next;
1549         LIST_HEAD(to_be_aged);
1550
1551         dprintk("svc_age_temp_sockets\n");
1552
1553         if (!spin_trylock_bh(&serv->sv_lock)) {
1554                 /* busy, try again 1 sec later */
1555                 dprintk("svc_age_temp_sockets: busy\n");
1556                 mod_timer(&serv->sv_temptimer, jiffies + HZ);
1557                 return;
1558         }
1559
1560         list_for_each_safe(le, next, &serv->sv_tempsocks) {
1561                 svsk = list_entry(le, struct svc_sock, sk_list);
1562
1563                 if (!test_and_set_bit(SK_OLD, &svsk->sk_flags))
1564                         continue;
1565                 if (atomic_read(&svsk->sk_inuse) || test_bit(SK_BUSY, &svsk->sk_flags))
1566                         continue;
1567                 atomic_inc(&svsk->sk_inuse);
1568                 list_move(le, &to_be_aged);
1569                 set_bit(SK_CLOSE, &svsk->sk_flags);
1570                 set_bit(SK_DETACHED, &svsk->sk_flags);
1571         }
1572         spin_unlock_bh(&serv->sv_lock);
1573
1574         while (!list_empty(&to_be_aged)) {
1575                 le = to_be_aged.next;
1576                 /* fiddling the sk_list node is safe 'cos we're SK_DETACHED */
1577                 list_del_init(le);
1578                 svsk = list_entry(le, struct svc_sock, sk_list);
1579
1580                 dprintk("queuing svsk %p for closing, %lu seconds old\n",
1581                         svsk, get_seconds() - svsk->sk_lastrecv);
1582
1583                 /* a thread will dequeue and close it soon */
1584                 svc_sock_enqueue(svsk);
1585                 svc_sock_put(svsk);
1586         }
1587
1588         mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
1589 }
1590
1591 /*
1592  * Initialize socket for RPC use and create svc_sock struct
1593  * XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
1594  */
1595 static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1596                                                 struct socket *sock,
1597                                                 int *errp, int flags)
1598 {
1599         struct svc_sock *svsk;
1600         struct sock     *inet;
1601         int             pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1602         int             is_temporary = flags & SVC_SOCK_TEMPORARY;
1603
1604         dprintk("svc: svc_setup_socket %p\n", sock);
1605         if (!(svsk = kzalloc(sizeof(*svsk), GFP_KERNEL))) {
1606                 *errp = -ENOMEM;
1607                 return NULL;
1608         }
1609
1610         inet = sock->sk;
1611
1612         /* Register socket with portmapper */
1613         if (*errp >= 0 && pmap_register)
1614                 *errp = svc_register(serv, inet->sk_protocol,
1615                                      ntohs(inet_sk(inet)->sport));
1616
1617         if (*errp < 0) {
1618                 kfree(svsk);
1619                 return NULL;
1620         }
1621
1622         set_bit(SK_BUSY, &svsk->sk_flags);
1623         inet->sk_user_data = svsk;
1624         svsk->sk_sock = sock;
1625         svsk->sk_sk = inet;
1626         svsk->sk_ostate = inet->sk_state_change;
1627         svsk->sk_odata = inet->sk_data_ready;
1628         svsk->sk_owspace = inet->sk_write_space;
1629         svsk->sk_server = serv;
1630         atomic_set(&svsk->sk_inuse, 1);
1631         svsk->sk_lastrecv = get_seconds();
1632         spin_lock_init(&svsk->sk_defer_lock);
1633         INIT_LIST_HEAD(&svsk->sk_deferred);
1634         INIT_LIST_HEAD(&svsk->sk_ready);
1635         mutex_init(&svsk->sk_mutex);
1636
1637         /* Initialize the socket */
1638         if (sock->type == SOCK_DGRAM)
1639                 svc_udp_init(svsk);
1640         else
1641                 svc_tcp_init(svsk);
1642
1643         spin_lock_bh(&serv->sv_lock);
1644         if (is_temporary) {
1645                 set_bit(SK_TEMP, &svsk->sk_flags);
1646                 list_add(&svsk->sk_list, &serv->sv_tempsocks);
1647                 serv->sv_tmpcnt++;
1648                 if (serv->sv_temptimer.function == NULL) {
1649                         /* setup timer to age temp sockets */
1650                         setup_timer(&serv->sv_temptimer, svc_age_temp_sockets,
1651                                         (unsigned long)serv);
1652                         mod_timer(&serv->sv_temptimer,
1653                                         jiffies + svc_conn_age_period * HZ);
1654                 }
1655         } else {
1656                 clear_bit(SK_TEMP, &svsk->sk_flags);
1657                 list_add(&svsk->sk_list, &serv->sv_permsocks);
1658         }
1659         spin_unlock_bh(&serv->sv_lock);
1660
1661         dprintk("svc: svc_setup_socket created %p (inet %p)\n",
1662                                 svsk, svsk->sk_sk);
1663
1664         return svsk;
1665 }
1666
1667 int svc_addsock(struct svc_serv *serv,
1668                 int fd,
1669                 char *name_return,
1670                 int *proto)
1671 {
1672         int err = 0;
1673         struct socket *so = sockfd_lookup(fd, &err);
1674         struct svc_sock *svsk = NULL;
1675
1676         if (!so)
1677                 return err;
1678         if (so->sk->sk_family != AF_INET)
1679                 err =  -EAFNOSUPPORT;
1680         else if (so->sk->sk_protocol != IPPROTO_TCP &&
1681             so->sk->sk_protocol != IPPROTO_UDP)
1682                 err =  -EPROTONOSUPPORT;
1683         else if (so->state > SS_UNCONNECTED)
1684                 err = -EISCONN;
1685         else {
1686                 svsk = svc_setup_socket(serv, so, &err, SVC_SOCK_DEFAULTS);
1687                 if (svsk) {
1688                         svc_sock_received(svsk);
1689                         err = 0;
1690                 }
1691         }
1692         if (err) {
1693                 sockfd_put(so);
1694                 return err;
1695         }
1696         if (proto) *proto = so->sk->sk_protocol;
1697         return one_sock_name(name_return, svsk);
1698 }
1699 EXPORT_SYMBOL_GPL(svc_addsock);
1700
1701 /*
1702  * Create socket for RPC service.
1703  */
1704 static int svc_create_socket(struct svc_serv *serv, int protocol,
1705                                 struct sockaddr *sin, int len, int flags)
1706 {
1707         struct svc_sock *svsk;
1708         struct socket   *sock;
1709         int             error;
1710         int             type;
1711         char            buf[RPC_MAX_ADDRBUFLEN];
1712
1713         dprintk("svc: svc_create_socket(%s, %d, %s)\n",
1714                         serv->sv_program->pg_name, protocol,
1715                         __svc_print_addr(sin, buf, sizeof(buf)));
1716
1717         if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1718                 printk(KERN_WARNING "svc: only UDP and TCP "
1719                                 "sockets supported\n");
1720                 return -EINVAL;
1721         }
1722         type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1723
1724         error = sock_create_kern(sin->sa_family, type, protocol, &sock);
1725         if (error < 0)
1726                 return error;
1727
1728         svc_reclassify_socket(sock);
1729
1730         if (type == SOCK_STREAM)
1731                 sock->sk->sk_reuse = 1;         /* allow address reuse */
1732         error = kernel_bind(sock, sin, len);
1733         if (error < 0)
1734                 goto bummer;
1735
1736         if (protocol == IPPROTO_TCP) {
1737                 if ((error = kernel_listen(sock, 64)) < 0)
1738                         goto bummer;
1739         }
1740
1741         if ((svsk = svc_setup_socket(serv, sock, &error, flags)) != NULL) {
1742                 svc_sock_received(svsk);
1743                 return ntohs(inet_sk(svsk->sk_sk)->sport);
1744         }
1745
1746 bummer:
1747         dprintk("svc: svc_create_socket error = %d\n", -error);
1748         sock_release(sock);
1749         return error;
1750 }
1751
1752 /*
1753  * Remove a dead socket
1754  */
1755 static void
1756 svc_delete_socket(struct svc_sock *svsk)
1757 {
1758         struct svc_serv *serv;
1759         struct sock     *sk;
1760
1761         dprintk("svc: svc_delete_socket(%p)\n", svsk);
1762
1763         serv = svsk->sk_server;
1764         sk = svsk->sk_sk;
1765
1766         sk->sk_state_change = svsk->sk_ostate;
1767         sk->sk_data_ready = svsk->sk_odata;
1768         sk->sk_write_space = svsk->sk_owspace;
1769
1770         spin_lock_bh(&serv->sv_lock);
1771
1772         if (!test_and_set_bit(SK_DETACHED, &svsk->sk_flags))
1773                 list_del_init(&svsk->sk_list);
1774         /*
1775          * We used to delete the svc_sock from whichever list
1776          * it's sk_ready node was on, but we don't actually
1777          * need to.  This is because the only time we're called
1778          * while still attached to a queue, the queue itself
1779          * is about to be destroyed (in svc_destroy).
1780          */
1781         if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags)) {
1782                 BUG_ON(atomic_read(&svsk->sk_inuse)<2);
1783                 atomic_dec(&svsk->sk_inuse);
1784                 if (test_bit(SK_TEMP, &svsk->sk_flags))
1785                         serv->sv_tmpcnt--;
1786         }
1787
1788         spin_unlock_bh(&serv->sv_lock);
1789 }
1790
1791 static void svc_close_socket(struct svc_sock *svsk)
1792 {
1793         set_bit(SK_CLOSE, &svsk->sk_flags);
1794         if (test_and_set_bit(SK_BUSY, &svsk->sk_flags))
1795                 /* someone else will have to effect the close */
1796                 return;
1797
1798         atomic_inc(&svsk->sk_inuse);
1799         svc_delete_socket(svsk);
1800         clear_bit(SK_BUSY, &svsk->sk_flags);
1801         svc_sock_put(svsk);
1802 }
1803
1804 void svc_force_close_socket(struct svc_sock *svsk)
1805 {
1806         set_bit(SK_CLOSE, &svsk->sk_flags);
1807         if (test_bit(SK_BUSY, &svsk->sk_flags)) {
1808                 /* Waiting to be processed, but no threads left,
1809                  * So just remove it from the waiting list
1810                  */
1811                 list_del_init(&svsk->sk_ready);
1812                 clear_bit(SK_BUSY, &svsk->sk_flags);
1813         }
1814         svc_close_socket(svsk);
1815 }
1816
1817 /**
1818  * svc_makesock - Make a socket for nfsd and lockd
1819  * @serv: RPC server structure
1820  * @protocol: transport protocol to use
1821  * @port: port to use
1822  * @flags: requested socket characteristics
1823  *
1824  */
1825 int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port,
1826                         int flags)
1827 {
1828         struct sockaddr_in sin = {
1829                 .sin_family             = AF_INET,
1830                 .sin_addr.s_addr        = INADDR_ANY,
1831                 .sin_port               = htons(port),
1832         };
1833
1834         dprintk("svc: creating socket proto = %d\n", protocol);
1835         return svc_create_socket(serv, protocol, (struct sockaddr *) &sin,
1836                                                         sizeof(sin), flags);
1837 }
1838
1839 /*
1840  * Handle defer and revisit of requests
1841  */
1842
1843 static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
1844 {
1845         struct svc_deferred_req *dr = container_of(dreq, struct svc_deferred_req, handle);
1846         struct svc_sock *svsk;
1847
1848         if (too_many) {
1849                 svc_sock_put(dr->svsk);
1850                 kfree(dr);
1851                 return;
1852         }
1853         dprintk("revisit queued\n");
1854         svsk = dr->svsk;
1855         dr->svsk = NULL;
1856         spin_lock_bh(&svsk->sk_defer_lock);
1857         list_add(&dr->handle.recent, &svsk->sk_deferred);
1858         spin_unlock_bh(&svsk->sk_defer_lock);
1859         set_bit(SK_DEFERRED, &svsk->sk_flags);
1860         svc_sock_enqueue(svsk);
1861         svc_sock_put(svsk);
1862 }
1863
1864 static struct cache_deferred_req *
1865 svc_defer(struct cache_req *req)
1866 {
1867         struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
1868         int size = sizeof(struct svc_deferred_req) + (rqstp->rq_arg.len);
1869         struct svc_deferred_req *dr;
1870
1871         if (rqstp->rq_arg.page_len)
1872                 return NULL; /* if more than a page, give up FIXME */
1873         if (rqstp->rq_deferred) {
1874                 dr = rqstp->rq_deferred;
1875                 rqstp->rq_deferred = NULL;
1876         } else {
1877                 int skip  = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1878                 /* FIXME maybe discard if size too large */
1879                 dr = kmalloc(size, GFP_KERNEL);
1880                 if (dr == NULL)
1881                         return NULL;
1882
1883                 dr->handle.owner = rqstp->rq_server;
1884                 dr->prot = rqstp->rq_prot;
1885                 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1886                 dr->addrlen = rqstp->rq_addrlen;
1887                 dr->daddr = rqstp->rq_daddr;
1888                 dr->argslen = rqstp->rq_arg.len >> 2;
1889                 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2);
1890         }
1891         atomic_inc(&rqstp->rq_sock->sk_inuse);
1892         dr->svsk = rqstp->rq_sock;
1893
1894         dr->handle.revisit = svc_revisit;
1895         return &dr->handle;
1896 }
1897
1898 /*
1899  * recv data from a deferred request into an active one
1900  */
1901 static int svc_deferred_recv(struct svc_rqst *rqstp)
1902 {
1903         struct svc_deferred_req *dr = rqstp->rq_deferred;
1904
1905         rqstp->rq_arg.head[0].iov_base = dr->args;
1906         rqstp->rq_arg.head[0].iov_len = dr->argslen<<2;
1907         rqstp->rq_arg.page_len = 0;
1908         rqstp->rq_arg.len = dr->argslen<<2;
1909         rqstp->rq_prot        = dr->prot;
1910         memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1911         rqstp->rq_addrlen     = dr->addrlen;
1912         rqstp->rq_daddr       = dr->daddr;
1913         rqstp->rq_respages    = rqstp->rq_pages;
1914         return dr->argslen<<2;
1915 }
1916
1917
1918 static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk)
1919 {
1920         struct svc_deferred_req *dr = NULL;
1921
1922         if (!test_bit(SK_DEFERRED, &svsk->sk_flags))
1923                 return NULL;
1924         spin_lock_bh(&svsk->sk_defer_lock);
1925         clear_bit(SK_DEFERRED, &svsk->sk_flags);
1926         if (!list_empty(&svsk->sk_deferred)) {
1927                 dr = list_entry(svsk->sk_deferred.next,
1928                                 struct svc_deferred_req,
1929                                 handle.recent);
1930                 list_del_init(&dr->handle.recent);
1931                 set_bit(SK_DEFERRED, &svsk->sk_flags);
1932         }
1933         spin_unlock_bh(&svsk->sk_defer_lock);
1934         return dr;
1935 }