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-rw-r--r--net/sunrpc/svc_xprt.c1055
1 files changed, 1055 insertions, 0 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
new file mode 100644
index 000000000000..ea377e06afae
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1/*
2 * linux/net/sunrpc/svc_xprt.c
3 *
4 * Author: Tom Tucker <tom@opengridcomputing.com>
5 */
6
7#include <linux/sched.h>
8#include <linux/errno.h>
9#include <linux/fcntl.h>
10#include <linux/net.h>
11#include <linux/in.h>
12#include <linux/inet.h>
13#include <linux/udp.h>
14#include <linux/tcp.h>
15#include <linux/unistd.h>
16#include <linux/slab.h>
17#include <linux/netdevice.h>
18#include <linux/skbuff.h>
19#include <linux/file.h>
20#include <linux/freezer.h>
21#include <net/sock.h>
22#include <net/checksum.h>
23#include <net/ip.h>
24#include <net/ipv6.h>
25#include <net/tcp_states.h>
26#include <linux/uaccess.h>
27#include <asm/ioctls.h>
28
29#include <linux/sunrpc/types.h>
30#include <linux/sunrpc/clnt.h>
31#include <linux/sunrpc/xdr.h>
32#include <linux/sunrpc/stats.h>
33#include <linux/sunrpc/svc_xprt.h>
34
35#define RPCDBG_FACILITY RPCDBG_SVCXPRT
36
37static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
38static int svc_deferred_recv(struct svc_rqst *rqstp);
39static struct cache_deferred_req *svc_defer(struct cache_req *req);
40static void svc_age_temp_xprts(unsigned long closure);
41
42/* apparently the "standard" is that clients close
43 * idle connections after 5 minutes, servers after
44 * 6 minutes
45 * http://www.connectathon.org/talks96/nfstcp.pdf
46 */
47static int svc_conn_age_period = 6*60;
48
49/* List of registered transport classes */
50static DEFINE_SPINLOCK(svc_xprt_class_lock);
51static LIST_HEAD(svc_xprt_class_list);
52
53/* SMP locking strategy:
54 *
55 * svc_pool->sp_lock protects most of the fields of that pool.
56 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
57 * when both need to be taken (rare), svc_serv->sv_lock is first.
58 * BKL protects svc_serv->sv_nrthread.
59 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
60 * and the ->sk_info_authunix cache.
61 *
62 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
63 * enqueued multiply. During normal transport processing this bit
64 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
65 * Providers should not manipulate this bit directly.
66 *
67 * Some flags can be set to certain values at any time
68 * providing that certain rules are followed:
69 *
70 * XPT_CONN, XPT_DATA:
71 * - Can be set or cleared at any time.
72 * - After a set, svc_xprt_enqueue must be called to enqueue
73 * the transport for processing.
74 * - After a clear, the transport must be read/accepted.
75 * If this succeeds, it must be set again.
76 * XPT_CLOSE:
77 * - Can set at any time. It is never cleared.
78 * XPT_DEAD:
79 * - Can only be set while XPT_BUSY is held which ensures
80 * that no other thread will be using the transport or will
81 * try to set XPT_DEAD.
82 */
83
84int svc_reg_xprt_class(struct svc_xprt_class *xcl)
85{
86 struct svc_xprt_class *cl;
87 int res = -EEXIST;
88
89 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
90
91 INIT_LIST_HEAD(&xcl->xcl_list);
92 spin_lock(&svc_xprt_class_lock);
93 /* Make sure there isn't already a class with the same name */
94 list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
95 if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
96 goto out;
97 }
98 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
99 res = 0;
100out:
101 spin_unlock(&svc_xprt_class_lock);
102 return res;
103}
104EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
105
106void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
107{
108 dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
109 spin_lock(&svc_xprt_class_lock);
110 list_del_init(&xcl->xcl_list);
111 spin_unlock(&svc_xprt_class_lock);
112}
113EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
114
115/*
116 * Format the transport list for printing
117 */
118int svc_print_xprts(char *buf, int maxlen)
119{
120 struct list_head *le;
121 char tmpstr[80];
122 int len = 0;
123 buf[0] = '\0';
124
125 spin_lock(&svc_xprt_class_lock);
126 list_for_each(le, &svc_xprt_class_list) {
127 int slen;
128 struct svc_xprt_class *xcl =
129 list_entry(le, struct svc_xprt_class, xcl_list);
130
131 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
132 slen = strlen(tmpstr);
133 if (len + slen > maxlen)
134 break;
135 len += slen;
136 strcat(buf, tmpstr);
137 }
138 spin_unlock(&svc_xprt_class_lock);
139
140 return len;
141}
142
143static void svc_xprt_free(struct kref *kref)
144{
145 struct svc_xprt *xprt =
146 container_of(kref, struct svc_xprt, xpt_ref);
147 struct module *owner = xprt->xpt_class->xcl_owner;
148 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)
149 && xprt->xpt_auth_cache != NULL)
150 svcauth_unix_info_release(xprt->xpt_auth_cache);
151 xprt->xpt_ops->xpo_free(xprt);
152 module_put(owner);
153}
154
155void svc_xprt_put(struct svc_xprt *xprt)
156{
157 kref_put(&xprt->xpt_ref, svc_xprt_free);
158}
159EXPORT_SYMBOL_GPL(svc_xprt_put);
160
161/*
162 * Called by transport drivers to initialize the transport independent
163 * portion of the transport instance.
164 */
165void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
166 struct svc_serv *serv)
167{
168 memset(xprt, 0, sizeof(*xprt));
169 xprt->xpt_class = xcl;
170 xprt->xpt_ops = xcl->xcl_ops;
171 kref_init(&xprt->xpt_ref);
172 xprt->xpt_server = serv;
173 INIT_LIST_HEAD(&xprt->xpt_list);
174 INIT_LIST_HEAD(&xprt->xpt_ready);
175 INIT_LIST_HEAD(&xprt->xpt_deferred);
176 mutex_init(&xprt->xpt_mutex);
177 spin_lock_init(&xprt->xpt_lock);
178 set_bit(XPT_BUSY, &xprt->xpt_flags);
179}
180EXPORT_SYMBOL_GPL(svc_xprt_init);
181
182int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
183 int flags)
184{
185 struct svc_xprt_class *xcl;
186 struct sockaddr_in sin = {
187 .sin_family = AF_INET,
188 .sin_addr.s_addr = INADDR_ANY,
189 .sin_port = htons(port),
190 };
191 dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
192 spin_lock(&svc_xprt_class_lock);
193 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
194 struct svc_xprt *newxprt;
195
196 if (strcmp(xprt_name, xcl->xcl_name))
197 continue;
198
199 if (!try_module_get(xcl->xcl_owner))
200 goto err;
201
202 spin_unlock(&svc_xprt_class_lock);
203 newxprt = xcl->xcl_ops->
204 xpo_create(serv, (struct sockaddr *)&sin, sizeof(sin),
205 flags);
206 if (IS_ERR(newxprt)) {
207 module_put(xcl->xcl_owner);
208 return PTR_ERR(newxprt);
209 }
210
211 clear_bit(XPT_TEMP, &newxprt->xpt_flags);
212 spin_lock_bh(&serv->sv_lock);
213 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
214 spin_unlock_bh(&serv->sv_lock);
215 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
216 return svc_xprt_local_port(newxprt);
217 }
218 err:
219 spin_unlock(&svc_xprt_class_lock);
220 dprintk("svc: transport %s not found\n", xprt_name);
221 return -ENOENT;
222}
223EXPORT_SYMBOL_GPL(svc_create_xprt);
224
225/*
226 * Copy the local and remote xprt addresses to the rqstp structure
227 */
228void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
229{
230 struct sockaddr *sin;
231
232 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
233 rqstp->rq_addrlen = xprt->xpt_remotelen;
234
235 /*
236 * Destination address in request is needed for binding the
237 * source address in RPC replies/callbacks later.
238 */
239 sin = (struct sockaddr *)&xprt->xpt_local;
240 switch (sin->sa_family) {
241 case AF_INET:
242 rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
243 break;
244 case AF_INET6:
245 rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
246 break;
247 }
248}
249EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
250
251/**
252 * svc_print_addr - Format rq_addr field for printing
253 * @rqstp: svc_rqst struct containing address to print
254 * @buf: target buffer for formatted address
255 * @len: length of target buffer
256 *
257 */
258char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
259{
260 return __svc_print_addr(svc_addr(rqstp), buf, len);
261}
262EXPORT_SYMBOL_GPL(svc_print_addr);
263
264/*
265 * Queue up an idle server thread. Must have pool->sp_lock held.
266 * Note: this is really a stack rather than a queue, so that we only
267 * use as many different threads as we need, and the rest don't pollute
268 * the cache.
269 */
270static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
271{
272 list_add(&rqstp->rq_list, &pool->sp_threads);
273}
274
275/*
276 * Dequeue an nfsd thread. Must have pool->sp_lock held.
277 */
278static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
279{
280 list_del(&rqstp->rq_list);
281}
282
283/*
284 * Queue up a transport with data pending. If there are idle nfsd
285 * processes, wake 'em up.
286 *
287 */
288void svc_xprt_enqueue(struct svc_xprt *xprt)
289{
290 struct svc_serv *serv = xprt->xpt_server;
291 struct svc_pool *pool;
292 struct svc_rqst *rqstp;
293 int cpu;
294
295 if (!(xprt->xpt_flags &
296 ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
297 return;
298 if (test_bit(XPT_DEAD, &xprt->xpt_flags))
299 return;
300
301 cpu = get_cpu();
302 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
303 put_cpu();
304
305 spin_lock_bh(&pool->sp_lock);
306
307 if (!list_empty(&pool->sp_threads) &&
308 !list_empty(&pool->sp_sockets))
309 printk(KERN_ERR
310 "svc_xprt_enqueue: "
311 "threads and transports both waiting??\n");
312
313 if (test_bit(XPT_DEAD, &xprt->xpt_flags)) {
314 /* Don't enqueue dead transports */
315 dprintk("svc: transport %p is dead, not enqueued\n", xprt);
316 goto out_unlock;
317 }
318
319 /* Mark transport as busy. It will remain in this state until
320 * the provider calls svc_xprt_received. We update XPT_BUSY
321 * atomically because it also guards against trying to enqueue
322 * the transport twice.
323 */
324 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
325 /* Don't enqueue transport while already enqueued */
326 dprintk("svc: transport %p busy, not enqueued\n", xprt);
327 goto out_unlock;
328 }
329 BUG_ON(xprt->xpt_pool != NULL);
330 xprt->xpt_pool = pool;
331
332 /* Handle pending connection */
333 if (test_bit(XPT_CONN, &xprt->xpt_flags))
334 goto process;
335
336 /* Handle close in-progress */
337 if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
338 goto process;
339
340 /* Check if we have space to reply to a request */
341 if (!xprt->xpt_ops->xpo_has_wspace(xprt)) {
342 /* Don't enqueue while not enough space for reply */
343 dprintk("svc: no write space, transport %p not enqueued\n",
344 xprt);
345 xprt->xpt_pool = NULL;
346 clear_bit(XPT_BUSY, &xprt->xpt_flags);
347 goto out_unlock;
348 }
349
350 process:
351 if (!list_empty(&pool->sp_threads)) {
352 rqstp = list_entry(pool->sp_threads.next,
353 struct svc_rqst,
354 rq_list);
355 dprintk("svc: transport %p served by daemon %p\n",
356 xprt, rqstp);
357 svc_thread_dequeue(pool, rqstp);
358 if (rqstp->rq_xprt)
359 printk(KERN_ERR
360 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
361 rqstp, rqstp->rq_xprt);
362 rqstp->rq_xprt = xprt;
363 svc_xprt_get(xprt);
364 rqstp->rq_reserved = serv->sv_max_mesg;
365 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
366 BUG_ON(xprt->xpt_pool != pool);
367 wake_up(&rqstp->rq_wait);
368 } else {
369 dprintk("svc: transport %p put into queue\n", xprt);
370 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
371 BUG_ON(xprt->xpt_pool != pool);
372 }
373
374out_unlock:
375 spin_unlock_bh(&pool->sp_lock);
376}
377EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
378
379/*
380 * Dequeue the first transport. Must be called with the pool->sp_lock held.
381 */
382static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
383{
384 struct svc_xprt *xprt;
385
386 if (list_empty(&pool->sp_sockets))
387 return NULL;
388
389 xprt = list_entry(pool->sp_sockets.next,
390 struct svc_xprt, xpt_ready);
391 list_del_init(&xprt->xpt_ready);
392
393 dprintk("svc: transport %p dequeued, inuse=%d\n",
394 xprt, atomic_read(&xprt->xpt_ref.refcount));
395
396 return xprt;
397}
398
399/*
400 * svc_xprt_received conditionally queues the transport for processing
401 * by another thread. The caller must hold the XPT_BUSY bit and must
402 * not thereafter touch transport data.
403 *
404 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
405 * insufficient) data.
406 */
407void svc_xprt_received(struct svc_xprt *xprt)
408{
409 BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
410 xprt->xpt_pool = NULL;
411 clear_bit(XPT_BUSY, &xprt->xpt_flags);
412 svc_xprt_enqueue(xprt);
413}
414EXPORT_SYMBOL_GPL(svc_xprt_received);
415
416/**
417 * svc_reserve - change the space reserved for the reply to a request.
418 * @rqstp: The request in question
419 * @space: new max space to reserve
420 *
421 * Each request reserves some space on the output queue of the transport
422 * to make sure the reply fits. This function reduces that reserved
423 * space to be the amount of space used already, plus @space.
424 *
425 */
426void svc_reserve(struct svc_rqst *rqstp, int space)
427{
428 space += rqstp->rq_res.head[0].iov_len;
429
430 if (space < rqstp->rq_reserved) {
431 struct svc_xprt *xprt = rqstp->rq_xprt;
432 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
433 rqstp->rq_reserved = space;
434
435 svc_xprt_enqueue(xprt);
436 }
437}
438EXPORT_SYMBOL(svc_reserve);
439
440static void svc_xprt_release(struct svc_rqst *rqstp)
441{
442 struct svc_xprt *xprt = rqstp->rq_xprt;
443
444 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
445
446 svc_free_res_pages(rqstp);
447 rqstp->rq_res.page_len = 0;
448 rqstp->rq_res.page_base = 0;
449
450 /* Reset response buffer and release
451 * the reservation.
452 * But first, check that enough space was reserved
453 * for the reply, otherwise we have a bug!
454 */
455 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
456 printk(KERN_ERR "RPC request reserved %d but used %d\n",
457 rqstp->rq_reserved,
458 rqstp->rq_res.len);
459
460 rqstp->rq_res.head[0].iov_len = 0;
461 svc_reserve(rqstp, 0);
462 rqstp->rq_xprt = NULL;
463
464 svc_xprt_put(xprt);
465}
466
467/*
468 * External function to wake up a server waiting for data
469 * This really only makes sense for services like lockd
470 * which have exactly one thread anyway.
471 */
472void svc_wake_up(struct svc_serv *serv)
473{
474 struct svc_rqst *rqstp;
475 unsigned int i;
476 struct svc_pool *pool;
477
478 for (i = 0; i < serv->sv_nrpools; i++) {
479 pool = &serv->sv_pools[i];
480
481 spin_lock_bh(&pool->sp_lock);
482 if (!list_empty(&pool->sp_threads)) {
483 rqstp = list_entry(pool->sp_threads.next,
484 struct svc_rqst,
485 rq_list);
486 dprintk("svc: daemon %p woken up.\n", rqstp);
487 /*
488 svc_thread_dequeue(pool, rqstp);
489 rqstp->rq_xprt = NULL;
490 */
491 wake_up(&rqstp->rq_wait);
492 }
493 spin_unlock_bh(&pool->sp_lock);
494 }
495}
496EXPORT_SYMBOL(svc_wake_up);
497
498int svc_port_is_privileged(struct sockaddr *sin)
499{
500 switch (sin->sa_family) {
501 case AF_INET:
502 return ntohs(((struct sockaddr_in *)sin)->sin_port)
503 < PROT_SOCK;
504 case AF_INET6:
505 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
506 < PROT_SOCK;
507 default:
508 return 0;
509 }
510}
511
512/*
513 * Make sure that we don't have too many active connections. If we
514 * have, something must be dropped.
515 *
516 * There's no point in trying to do random drop here for DoS
517 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
518 * attacker can easily beat that.
519 *
520 * The only somewhat efficient mechanism would be if drop old
521 * connections from the same IP first. But right now we don't even
522 * record the client IP in svc_sock.
523 */
524static void svc_check_conn_limits(struct svc_serv *serv)
525{
526 if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
527 struct svc_xprt *xprt = NULL;
528 spin_lock_bh(&serv->sv_lock);
529 if (!list_empty(&serv->sv_tempsocks)) {
530 if (net_ratelimit()) {
531 /* Try to help the admin */
532 printk(KERN_NOTICE "%s: too many open "
533 "connections, consider increasing the "
534 "number of nfsd threads\n",
535 serv->sv_name);
536 }
537 /*
538 * Always select the oldest connection. It's not fair,
539 * but so is life
540 */
541 xprt = list_entry(serv->sv_tempsocks.prev,
542 struct svc_xprt,
543 xpt_list);
544 set_bit(XPT_CLOSE, &xprt->xpt_flags);
545 svc_xprt_get(xprt);
546 }
547 spin_unlock_bh(&serv->sv_lock);
548
549 if (xprt) {
550 svc_xprt_enqueue(xprt);
551 svc_xprt_put(xprt);
552 }
553 }
554}
555
556/*
557 * Receive the next request on any transport. This code is carefully
558 * organised not to touch any cachelines in the shared svc_serv
559 * structure, only cachelines in the local svc_pool.
560 */
561int svc_recv(struct svc_rqst *rqstp, long timeout)
562{
563 struct svc_xprt *xprt = NULL;
564 struct svc_serv *serv = rqstp->rq_server;
565 struct svc_pool *pool = rqstp->rq_pool;
566 int len, i;
567 int pages;
568 struct xdr_buf *arg;
569 DECLARE_WAITQUEUE(wait, current);
570
571 dprintk("svc: server %p waiting for data (to = %ld)\n",
572 rqstp, timeout);
573
574 if (rqstp->rq_xprt)
575 printk(KERN_ERR
576 "svc_recv: service %p, transport not NULL!\n",
577 rqstp);
578 if (waitqueue_active(&rqstp->rq_wait))
579 printk(KERN_ERR
580 "svc_recv: service %p, wait queue active!\n",
581 rqstp);
582
583 /* now allocate needed pages. If we get a failure, sleep briefly */
584 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
585 for (i = 0; i < pages ; i++)
586 while (rqstp->rq_pages[i] == NULL) {
587 struct page *p = alloc_page(GFP_KERNEL);
588 if (!p) {
589 int j = msecs_to_jiffies(500);
590 schedule_timeout_uninterruptible(j);
591 }
592 rqstp->rq_pages[i] = p;
593 }
594 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
595 BUG_ON(pages >= RPCSVC_MAXPAGES);
596
597 /* Make arg->head point to first page and arg->pages point to rest */
598 arg = &rqstp->rq_arg;
599 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
600 arg->head[0].iov_len = PAGE_SIZE;
601 arg->pages = rqstp->rq_pages + 1;
602 arg->page_base = 0;
603 /* save at least one page for response */
604 arg->page_len = (pages-2)*PAGE_SIZE;
605 arg->len = (pages-1)*PAGE_SIZE;
606 arg->tail[0].iov_len = 0;
607
608 try_to_freeze();
609 cond_resched();
610 if (signalled())
611 return -EINTR;
612
613 spin_lock_bh(&pool->sp_lock);
614 xprt = svc_xprt_dequeue(pool);
615 if (xprt) {
616 rqstp->rq_xprt = xprt;
617 svc_xprt_get(xprt);
618 rqstp->rq_reserved = serv->sv_max_mesg;
619 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
620 } else {
621 /* No data pending. Go to sleep */
622 svc_thread_enqueue(pool, rqstp);
623
624 /*
625 * We have to be able to interrupt this wait
626 * to bring down the daemons ...
627 */
628 set_current_state(TASK_INTERRUPTIBLE);
629 add_wait_queue(&rqstp->rq_wait, &wait);
630 spin_unlock_bh(&pool->sp_lock);
631
632 schedule_timeout(timeout);
633
634 try_to_freeze();
635
636 spin_lock_bh(&pool->sp_lock);
637 remove_wait_queue(&rqstp->rq_wait, &wait);
638
639 xprt = rqstp->rq_xprt;
640 if (!xprt) {
641 svc_thread_dequeue(pool, rqstp);
642 spin_unlock_bh(&pool->sp_lock);
643 dprintk("svc: server %p, no data yet\n", rqstp);
644 return signalled()? -EINTR : -EAGAIN;
645 }
646 }
647 spin_unlock_bh(&pool->sp_lock);
648
649 len = 0;
650 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
651 dprintk("svc_recv: found XPT_CLOSE\n");
652 svc_delete_xprt(xprt);
653 } else if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
654 struct svc_xprt *newxpt;
655 newxpt = xprt->xpt_ops->xpo_accept(xprt);
656 if (newxpt) {
657 /*
658 * We know this module_get will succeed because the
659 * listener holds a reference too
660 */
661 __module_get(newxpt->xpt_class->xcl_owner);
662 svc_check_conn_limits(xprt->xpt_server);
663 spin_lock_bh(&serv->sv_lock);
664 set_bit(XPT_TEMP, &newxpt->xpt_flags);
665 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
666 serv->sv_tmpcnt++;
667 if (serv->sv_temptimer.function == NULL) {
668 /* setup timer to age temp transports */
669 setup_timer(&serv->sv_temptimer,
670 svc_age_temp_xprts,
671 (unsigned long)serv);
672 mod_timer(&serv->sv_temptimer,
673 jiffies + svc_conn_age_period * HZ);
674 }
675 spin_unlock_bh(&serv->sv_lock);
676 svc_xprt_received(newxpt);
677 }
678 svc_xprt_received(xprt);
679 } else {
680 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
681 rqstp, pool->sp_id, xprt,
682 atomic_read(&xprt->xpt_ref.refcount));
683 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
684 if (rqstp->rq_deferred) {
685 svc_xprt_received(xprt);
686 len = svc_deferred_recv(rqstp);
687 } else
688 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
689 dprintk("svc: got len=%d\n", len);
690 }
691
692 /* No data, incomplete (TCP) read, or accept() */
693 if (len == 0 || len == -EAGAIN) {
694 rqstp->rq_res.len = 0;
695 svc_xprt_release(rqstp);
696 return -EAGAIN;
697 }
698 clear_bit(XPT_OLD, &xprt->xpt_flags);
699
700 rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
701 rqstp->rq_chandle.defer = svc_defer;
702
703 if (serv->sv_stats)
704 serv->sv_stats->netcnt++;
705 return len;
706}
707EXPORT_SYMBOL(svc_recv);
708
709/*
710 * Drop request
711 */
712void svc_drop(struct svc_rqst *rqstp)
713{
714 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
715 svc_xprt_release(rqstp);
716}
717EXPORT_SYMBOL(svc_drop);
718
719/*
720 * Return reply to client.
721 */
722int svc_send(struct svc_rqst *rqstp)
723{
724 struct svc_xprt *xprt;
725 int len;
726 struct xdr_buf *xb;
727
728 xprt = rqstp->rq_xprt;
729 if (!xprt)
730 return -EFAULT;
731
732 /* release the receive skb before sending the reply */
733 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
734
735 /* calculate over-all length */
736 xb = &rqstp->rq_res;
737 xb->len = xb->head[0].iov_len +
738 xb->page_len +
739 xb->tail[0].iov_len;
740
741 /* Grab mutex to serialize outgoing data. */
742 mutex_lock(&xprt->xpt_mutex);
743 if (test_bit(XPT_DEAD, &xprt->xpt_flags))
744 len = -ENOTCONN;
745 else
746 len = xprt->xpt_ops->xpo_sendto(rqstp);
747 mutex_unlock(&xprt->xpt_mutex);
748 svc_xprt_release(rqstp);
749
750 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
751 return 0;
752 return len;
753}
754
755/*
756 * Timer function to close old temporary transports, using
757 * a mark-and-sweep algorithm.
758 */
759static void svc_age_temp_xprts(unsigned long closure)
760{
761 struct svc_serv *serv = (struct svc_serv *)closure;
762 struct svc_xprt *xprt;
763 struct list_head *le, *next;
764 LIST_HEAD(to_be_aged);
765
766 dprintk("svc_age_temp_xprts\n");
767
768 if (!spin_trylock_bh(&serv->sv_lock)) {
769 /* busy, try again 1 sec later */
770 dprintk("svc_age_temp_xprts: busy\n");
771 mod_timer(&serv->sv_temptimer, jiffies + HZ);
772 return;
773 }
774
775 list_for_each_safe(le, next, &serv->sv_tempsocks) {
776 xprt = list_entry(le, struct svc_xprt, xpt_list);
777
778 /* First time through, just mark it OLD. Second time
779 * through, close it. */
780 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
781 continue;
782 if (atomic_read(&xprt->xpt_ref.refcount) > 1
783 || test_bit(XPT_BUSY, &xprt->xpt_flags))
784 continue;
785 svc_xprt_get(xprt);
786 list_move(le, &to_be_aged);
787 set_bit(XPT_CLOSE, &xprt->xpt_flags);
788 set_bit(XPT_DETACHED, &xprt->xpt_flags);
789 }
790 spin_unlock_bh(&serv->sv_lock);
791
792 while (!list_empty(&to_be_aged)) {
793 le = to_be_aged.next;
794 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
795 list_del_init(le);
796 xprt = list_entry(le, struct svc_xprt, xpt_list);
797
798 dprintk("queuing xprt %p for closing\n", xprt);
799
800 /* a thread will dequeue and close it soon */
801 svc_xprt_enqueue(xprt);
802 svc_xprt_put(xprt);
803 }
804
805 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
806}
807
808/*
809 * Remove a dead transport
810 */
811void svc_delete_xprt(struct svc_xprt *xprt)
812{
813 struct svc_serv *serv = xprt->xpt_server;
814
815 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
816 xprt->xpt_ops->xpo_detach(xprt);
817
818 spin_lock_bh(&serv->sv_lock);
819 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
820 list_del_init(&xprt->xpt_list);
821 /*
822 * We used to delete the transport from whichever list
823 * it's sk_xprt.xpt_ready node was on, but we don't actually
824 * need to. This is because the only time we're called
825 * while still attached to a queue, the queue itself
826 * is about to be destroyed (in svc_destroy).
827 */
828 if (!test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) {
829 BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2);
830 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
831 serv->sv_tmpcnt--;
832 svc_xprt_put(xprt);
833 }
834 spin_unlock_bh(&serv->sv_lock);
835}
836
837void svc_close_xprt(struct svc_xprt *xprt)
838{
839 set_bit(XPT_CLOSE, &xprt->xpt_flags);
840 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
841 /* someone else will have to effect the close */
842 return;
843
844 svc_xprt_get(xprt);
845 svc_delete_xprt(xprt);
846 clear_bit(XPT_BUSY, &xprt->xpt_flags);
847 svc_xprt_put(xprt);
848}
849EXPORT_SYMBOL_GPL(svc_close_xprt);
850
851void svc_close_all(struct list_head *xprt_list)
852{
853 struct svc_xprt *xprt;
854 struct svc_xprt *tmp;
855
856 list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
857 set_bit(XPT_CLOSE, &xprt->xpt_flags);
858 if (test_bit(XPT_BUSY, &xprt->xpt_flags)) {
859 /* Waiting to be processed, but no threads left,
860 * So just remove it from the waiting list
861 */
862 list_del_init(&xprt->xpt_ready);
863 clear_bit(XPT_BUSY, &xprt->xpt_flags);
864 }
865 svc_close_xprt(xprt);
866 }
867}
868
869/*
870 * Handle defer and revisit of requests
871 */
872
873static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
874{
875 struct svc_deferred_req *dr =
876 container_of(dreq, struct svc_deferred_req, handle);
877 struct svc_xprt *xprt = dr->xprt;
878
879 if (too_many) {
880 svc_xprt_put(xprt);
881 kfree(dr);
882 return;
883 }
884 dprintk("revisit queued\n");
885 dr->xprt = NULL;
886 spin_lock(&xprt->xpt_lock);
887 list_add(&dr->handle.recent, &xprt->xpt_deferred);
888 spin_unlock(&xprt->xpt_lock);
889 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
890 svc_xprt_enqueue(xprt);
891 svc_xprt_put(xprt);
892}
893
894/*
895 * Save the request off for later processing. The request buffer looks
896 * like this:
897 *
898 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
899 *
900 * This code can only handle requests that consist of an xprt-header
901 * and rpc-header.
902 */
903static struct cache_deferred_req *svc_defer(struct cache_req *req)
904{
905 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
906 struct svc_deferred_req *dr;
907
908 if (rqstp->rq_arg.page_len)
909 return NULL; /* if more than a page, give up FIXME */
910 if (rqstp->rq_deferred) {
911 dr = rqstp->rq_deferred;
912 rqstp->rq_deferred = NULL;
913 } else {
914 size_t skip;
915 size_t size;
916 /* FIXME maybe discard if size too large */
917 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
918 dr = kmalloc(size, GFP_KERNEL);
919 if (dr == NULL)
920 return NULL;
921
922 dr->handle.owner = rqstp->rq_server;
923 dr->prot = rqstp->rq_prot;
924 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
925 dr->addrlen = rqstp->rq_addrlen;
926 dr->daddr = rqstp->rq_daddr;
927 dr->argslen = rqstp->rq_arg.len >> 2;
928 dr->xprt_hlen = rqstp->rq_xprt_hlen;
929
930 /* back up head to the start of the buffer and copy */
931 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
932 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
933 dr->argslen << 2);
934 }
935 svc_xprt_get(rqstp->rq_xprt);
936 dr->xprt = rqstp->rq_xprt;
937
938 dr->handle.revisit = svc_revisit;
939 return &dr->handle;
940}
941
942/*
943 * recv data from a deferred request into an active one
944 */
945static int svc_deferred_recv(struct svc_rqst *rqstp)
946{
947 struct svc_deferred_req *dr = rqstp->rq_deferred;
948
949 /* setup iov_base past transport header */
950 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
951 /* The iov_len does not include the transport header bytes */
952 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
953 rqstp->rq_arg.page_len = 0;
954 /* The rq_arg.len includes the transport header bytes */
955 rqstp->rq_arg.len = dr->argslen<<2;
956 rqstp->rq_prot = dr->prot;
957 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
958 rqstp->rq_addrlen = dr->addrlen;
959 /* Save off transport header len in case we get deferred again */
960 rqstp->rq_xprt_hlen = dr->xprt_hlen;
961 rqstp->rq_daddr = dr->daddr;
962 rqstp->rq_respages = rqstp->rq_pages;
963 return (dr->argslen<<2) - dr->xprt_hlen;
964}
965
966
967static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
968{
969 struct svc_deferred_req *dr = NULL;
970
971 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
972 return NULL;
973 spin_lock(&xprt->xpt_lock);
974 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
975 if (!list_empty(&xprt->xpt_deferred)) {
976 dr = list_entry(xprt->xpt_deferred.next,
977 struct svc_deferred_req,
978 handle.recent);
979 list_del_init(&dr->handle.recent);
980 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
981 }
982 spin_unlock(&xprt->xpt_lock);
983 return dr;
984}
985
986/*
987 * Return the transport instance pointer for the endpoint accepting
988 * connections/peer traffic from the specified transport class,
989 * address family and port.
990 *
991 * Specifying 0 for the address family or port is effectively a
992 * wild-card, and will result in matching the first transport in the
993 * service's list that has a matching class name.
994 */
995struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name,
996 int af, int port)
997{
998 struct svc_xprt *xprt;
999 struct svc_xprt *found = NULL;
1000
1001 /* Sanity check the args */
1002 if (!serv || !xcl_name)
1003 return found;
1004
1005 spin_lock_bh(&serv->sv_lock);
1006 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1007 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1008 continue;
1009 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1010 continue;
1011 if (port && port != svc_xprt_local_port(xprt))
1012 continue;
1013 found = xprt;
1014 svc_xprt_get(xprt);
1015 break;
1016 }
1017 spin_unlock_bh(&serv->sv_lock);
1018 return found;
1019}
1020EXPORT_SYMBOL_GPL(svc_find_xprt);
1021
1022/*
1023 * Format a buffer with a list of the active transports. A zero for
1024 * the buflen parameter disables target buffer overflow checking.
1025 */
1026int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen)
1027{
1028 struct svc_xprt *xprt;
1029 char xprt_str[64];
1030 int totlen = 0;
1031 int len;
1032
1033 /* Sanity check args */
1034 if (!serv)
1035 return 0;
1036
1037 spin_lock_bh(&serv->sv_lock);
1038 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1039 len = snprintf(xprt_str, sizeof(xprt_str),
1040 "%s %d\n", xprt->xpt_class->xcl_name,
1041 svc_xprt_local_port(xprt));
1042 /* If the string was truncated, replace with error string */
1043 if (len >= sizeof(xprt_str))
1044 strcpy(xprt_str, "name-too-long\n");
1045 /* Don't overflow buffer */
1046 len = strlen(xprt_str);
1047 if (buflen && (len + totlen >= buflen))
1048 break;
1049 strcpy(buf+totlen, xprt_str);
1050 totlen += len;
1051 }
1052 spin_unlock_bh(&serv->sv_lock);
1053 return totlen;
1054}
1055EXPORT_SYMBOL_GPL(svc_xprt_names);
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-19 07:13:36 -0500