2 * linux/net/sunrpc/svc_xprt.c
4 * Author: Tom Tucker <tom@opengridcomputing.com>
7 #include <linux/sched.h>
8 #include <linux/errno.h>
9 #include <linux/freezer.h>
10 #include <linux/kthread.h>
11 #include <linux/slab.h>
13 #include <linux/sunrpc/stats.h>
14 #include <linux/sunrpc/svc_xprt.h>
15 #include <linux/sunrpc/svcsock.h>
16 #include <linux/sunrpc/xprt.h>
17 #include <linux/module.h>
19 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
21 static struct svc_deferred_req
*svc_deferred_dequeue(struct svc_xprt
*xprt
);
22 static int svc_deferred_recv(struct svc_rqst
*rqstp
);
23 static struct cache_deferred_req
*svc_defer(struct cache_req
*req
);
24 static void svc_age_temp_xprts(unsigned long closure
);
25 static void svc_delete_xprt(struct svc_xprt
*xprt
);
27 /* apparently the "standard" is that clients close
28 * idle connections after 5 minutes, servers after
30 * http://www.connectathon.org/talks96/nfstcp.pdf
32 static int svc_conn_age_period
= 6*60;
34 /* List of registered transport classes */
35 static DEFINE_SPINLOCK(svc_xprt_class_lock
);
36 static LIST_HEAD(svc_xprt_class_list
);
38 /* SMP locking strategy:
40 * svc_pool->sp_lock protects most of the fields of that pool.
41 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
42 * when both need to be taken (rare), svc_serv->sv_lock is first.
43 * BKL protects svc_serv->sv_nrthread.
44 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
45 * and the ->sk_info_authunix cache.
47 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
48 * enqueued multiply. During normal transport processing this bit
49 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
50 * Providers should not manipulate this bit directly.
52 * Some flags can be set to certain values at any time
53 * providing that certain rules are followed:
56 * - Can be set or cleared at any time.
57 * - After a set, svc_xprt_enqueue must be called to enqueue
58 * the transport for processing.
59 * - After a clear, the transport must be read/accepted.
60 * If this succeeds, it must be set again.
62 * - Can set at any time. It is never cleared.
64 * - Can only be set while XPT_BUSY is held which ensures
65 * that no other thread will be using the transport or will
66 * try to set XPT_DEAD.
69 int svc_reg_xprt_class(struct svc_xprt_class
*xcl
)
71 struct svc_xprt_class
*cl
;
74 dprintk("svc: Adding svc transport class '%s'\n", xcl
->xcl_name
);
76 INIT_LIST_HEAD(&xcl
->xcl_list
);
77 spin_lock(&svc_xprt_class_lock
);
78 /* Make sure there isn't already a class with the same name */
79 list_for_each_entry(cl
, &svc_xprt_class_list
, xcl_list
) {
80 if (strcmp(xcl
->xcl_name
, cl
->xcl_name
) == 0)
83 list_add_tail(&xcl
->xcl_list
, &svc_xprt_class_list
);
86 spin_unlock(&svc_xprt_class_lock
);
89 EXPORT_SYMBOL_GPL(svc_reg_xprt_class
);
91 void svc_unreg_xprt_class(struct svc_xprt_class
*xcl
)
93 dprintk("svc: Removing svc transport class '%s'\n", xcl
->xcl_name
);
94 spin_lock(&svc_xprt_class_lock
);
95 list_del_init(&xcl
->xcl_list
);
96 spin_unlock(&svc_xprt_class_lock
);
98 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class
);
101 * Format the transport list for printing
103 int svc_print_xprts(char *buf
, int maxlen
)
105 struct svc_xprt_class
*xcl
;
110 spin_lock(&svc_xprt_class_lock
);
111 list_for_each_entry(xcl
, &svc_xprt_class_list
, xcl_list
) {
114 sprintf(tmpstr
, "%s %d\n", xcl
->xcl_name
, xcl
->xcl_max_payload
);
115 slen
= strlen(tmpstr
);
116 if (len
+ slen
> maxlen
)
121 spin_unlock(&svc_xprt_class_lock
);
126 static void svc_xprt_free(struct kref
*kref
)
128 struct svc_xprt
*xprt
=
129 container_of(kref
, struct svc_xprt
, xpt_ref
);
130 struct module
*owner
= xprt
->xpt_class
->xcl_owner
;
131 if (test_bit(XPT_CACHE_AUTH
, &xprt
->xpt_flags
))
132 svcauth_unix_info_release(xprt
);
133 put_net(xprt
->xpt_net
);
134 /* See comment on corresponding get in xs_setup_bc_tcp(): */
135 if (xprt
->xpt_bc_xprt
)
136 xprt_put(xprt
->xpt_bc_xprt
);
137 xprt
->xpt_ops
->xpo_free(xprt
);
141 void svc_xprt_put(struct svc_xprt
*xprt
)
143 kref_put(&xprt
->xpt_ref
, svc_xprt_free
);
145 EXPORT_SYMBOL_GPL(svc_xprt_put
);
148 * Called by transport drivers to initialize the transport independent
149 * portion of the transport instance.
151 void svc_xprt_init(struct net
*net
, struct svc_xprt_class
*xcl
,
152 struct svc_xprt
*xprt
, struct svc_serv
*serv
)
154 memset(xprt
, 0, sizeof(*xprt
));
155 xprt
->xpt_class
= xcl
;
156 xprt
->xpt_ops
= xcl
->xcl_ops
;
157 kref_init(&xprt
->xpt_ref
);
158 xprt
->xpt_server
= serv
;
159 INIT_LIST_HEAD(&xprt
->xpt_list
);
160 INIT_LIST_HEAD(&xprt
->xpt_ready
);
161 INIT_LIST_HEAD(&xprt
->xpt_deferred
);
162 INIT_LIST_HEAD(&xprt
->xpt_users
);
163 mutex_init(&xprt
->xpt_mutex
);
164 spin_lock_init(&xprt
->xpt_lock
);
165 set_bit(XPT_BUSY
, &xprt
->xpt_flags
);
166 rpc_init_wait_queue(&xprt
->xpt_bc_pending
, "xpt_bc_pending");
167 xprt
->xpt_net
= get_net(net
);
169 EXPORT_SYMBOL_GPL(svc_xprt_init
);
171 static struct svc_xprt
*__svc_xpo_create(struct svc_xprt_class
*xcl
,
172 struct svc_serv
*serv
,
175 const unsigned short port
,
178 struct sockaddr_in sin
= {
179 .sin_family
= AF_INET
,
180 .sin_addr
.s_addr
= htonl(INADDR_ANY
),
181 .sin_port
= htons(port
),
183 #if IS_ENABLED(CONFIG_IPV6)
184 struct sockaddr_in6 sin6
= {
185 .sin6_family
= AF_INET6
,
186 .sin6_addr
= IN6ADDR_ANY_INIT
,
187 .sin6_port
= htons(port
),
190 struct sockaddr
*sap
;
195 sap
= (struct sockaddr
*)&sin
;
198 #if IS_ENABLED(CONFIG_IPV6)
200 sap
= (struct sockaddr
*)&sin6
;
205 return ERR_PTR(-EAFNOSUPPORT
);
208 return xcl
->xcl_ops
->xpo_create(serv
, net
, sap
, len
, flags
);
211 int svc_create_xprt(struct svc_serv
*serv
, const char *xprt_name
,
212 struct net
*net
, const int family
,
213 const unsigned short port
, int flags
)
215 struct svc_xprt_class
*xcl
;
217 dprintk("svc: creating transport %s[%d]\n", xprt_name
, port
);
218 spin_lock(&svc_xprt_class_lock
);
219 list_for_each_entry(xcl
, &svc_xprt_class_list
, xcl_list
) {
220 struct svc_xprt
*newxprt
;
221 unsigned short newport
;
223 if (strcmp(xprt_name
, xcl
->xcl_name
))
226 if (!try_module_get(xcl
->xcl_owner
))
229 spin_unlock(&svc_xprt_class_lock
);
230 newxprt
= __svc_xpo_create(xcl
, serv
, net
, family
, port
, flags
);
231 if (IS_ERR(newxprt
)) {
232 module_put(xcl
->xcl_owner
);
233 return PTR_ERR(newxprt
);
236 clear_bit(XPT_TEMP
, &newxprt
->xpt_flags
);
237 spin_lock_bh(&serv
->sv_lock
);
238 list_add(&newxprt
->xpt_list
, &serv
->sv_permsocks
);
239 spin_unlock_bh(&serv
->sv_lock
);
240 newport
= svc_xprt_local_port(newxprt
);
241 clear_bit(XPT_BUSY
, &newxprt
->xpt_flags
);
245 spin_unlock(&svc_xprt_class_lock
);
246 dprintk("svc: transport %s not found\n", xprt_name
);
248 /* This errno is exposed to user space. Provide a reasonable
249 * perror msg for a bad transport. */
250 return -EPROTONOSUPPORT
;
252 EXPORT_SYMBOL_GPL(svc_create_xprt
);
255 * Copy the local and remote xprt addresses to the rqstp structure
257 void svc_xprt_copy_addrs(struct svc_rqst
*rqstp
, struct svc_xprt
*xprt
)
259 memcpy(&rqstp
->rq_addr
, &xprt
->xpt_remote
, xprt
->xpt_remotelen
);
260 rqstp
->rq_addrlen
= xprt
->xpt_remotelen
;
263 * Destination address in request is needed for binding the
264 * source address in RPC replies/callbacks later.
266 memcpy(&rqstp
->rq_daddr
, &xprt
->xpt_local
, xprt
->xpt_locallen
);
267 rqstp
->rq_daddrlen
= xprt
->xpt_locallen
;
269 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs
);
272 * svc_print_addr - Format rq_addr field for printing
273 * @rqstp: svc_rqst struct containing address to print
274 * @buf: target buffer for formatted address
275 * @len: length of target buffer
278 char *svc_print_addr(struct svc_rqst
*rqstp
, char *buf
, size_t len
)
280 return __svc_print_addr(svc_addr(rqstp
), buf
, len
);
282 EXPORT_SYMBOL_GPL(svc_print_addr
);
285 * Queue up an idle server thread. Must have pool->sp_lock held.
286 * Note: this is really a stack rather than a queue, so that we only
287 * use as many different threads as we need, and the rest don't pollute
290 static void svc_thread_enqueue(struct svc_pool
*pool
, struct svc_rqst
*rqstp
)
292 list_add(&rqstp
->rq_list
, &pool
->sp_threads
);
296 * Dequeue an nfsd thread. Must have pool->sp_lock held.
298 static void svc_thread_dequeue(struct svc_pool
*pool
, struct svc_rqst
*rqstp
)
300 list_del(&rqstp
->rq_list
);
303 static bool svc_xprt_has_something_to_do(struct svc_xprt
*xprt
)
305 if (xprt
->xpt_flags
& ((1<<XPT_CONN
)|(1<<XPT_CLOSE
)))
307 if (xprt
->xpt_flags
& ((1<<XPT_DATA
)|(1<<XPT_DEFERRED
)))
308 return xprt
->xpt_ops
->xpo_has_wspace(xprt
);
313 * Queue up a transport with data pending. If there are idle nfsd
314 * processes, wake 'em up.
317 void svc_xprt_enqueue(struct svc_xprt
*xprt
)
319 struct svc_pool
*pool
;
320 struct svc_rqst
*rqstp
;
323 if (!svc_xprt_has_something_to_do(xprt
))
327 pool
= svc_pool_for_cpu(xprt
->xpt_server
, cpu
);
330 spin_lock_bh(&pool
->sp_lock
);
332 if (!list_empty(&pool
->sp_threads
) &&
333 !list_empty(&pool
->sp_sockets
))
336 "threads and transports both waiting??\n");
338 pool
->sp_stats
.packets
++;
340 /* Mark transport as busy. It will remain in this state until
341 * the provider calls svc_xprt_received. We update XPT_BUSY
342 * atomically because it also guards against trying to enqueue
343 * the transport twice.
345 if (test_and_set_bit(XPT_BUSY
, &xprt
->xpt_flags
)) {
346 /* Don't enqueue transport while already enqueued */
347 dprintk("svc: transport %p busy, not enqueued\n", xprt
);
351 if (!list_empty(&pool
->sp_threads
)) {
352 rqstp
= list_entry(pool
->sp_threads
.next
,
355 dprintk("svc: transport %p served by daemon %p\n",
357 svc_thread_dequeue(pool
, rqstp
);
360 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
361 rqstp
, rqstp
->rq_xprt
);
362 rqstp
->rq_xprt
= xprt
;
364 pool
->sp_stats
.threads_woken
++;
365 wake_up(&rqstp
->rq_wait
);
367 dprintk("svc: transport %p put into queue\n", xprt
);
368 list_add_tail(&xprt
->xpt_ready
, &pool
->sp_sockets
);
369 pool
->sp_stats
.sockets_queued
++;
373 spin_unlock_bh(&pool
->sp_lock
);
375 EXPORT_SYMBOL_GPL(svc_xprt_enqueue
);
378 * Dequeue the first transport. Must be called with the pool->sp_lock held.
380 static struct svc_xprt
*svc_xprt_dequeue(struct svc_pool
*pool
)
382 struct svc_xprt
*xprt
;
384 if (list_empty(&pool
->sp_sockets
))
387 xprt
= list_entry(pool
->sp_sockets
.next
,
388 struct svc_xprt
, xpt_ready
);
389 list_del_init(&xprt
->xpt_ready
);
391 dprintk("svc: transport %p dequeued, inuse=%d\n",
392 xprt
, atomic_read(&xprt
->xpt_ref
.refcount
));
398 * svc_xprt_received conditionally queues the transport for processing
399 * by another thread. The caller must hold the XPT_BUSY bit and must
400 * not thereafter touch transport data.
402 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
403 * insufficient) data.
405 void svc_xprt_received(struct svc_xprt
*xprt
)
407 BUG_ON(!test_bit(XPT_BUSY
, &xprt
->xpt_flags
));
408 /* As soon as we clear busy, the xprt could be closed and
409 * 'put', so we need a reference to call svc_xprt_enqueue with:
412 clear_bit(XPT_BUSY
, &xprt
->xpt_flags
);
413 svc_xprt_enqueue(xprt
);
416 EXPORT_SYMBOL_GPL(svc_xprt_received
);
419 * svc_reserve - change the space reserved for the reply to a request.
420 * @rqstp: The request in question
421 * @space: new max space to reserve
423 * Each request reserves some space on the output queue of the transport
424 * to make sure the reply fits. This function reduces that reserved
425 * space to be the amount of space used already, plus @space.
428 void svc_reserve(struct svc_rqst
*rqstp
, int space
)
430 space
+= rqstp
->rq_res
.head
[0].iov_len
;
432 if (space
< rqstp
->rq_reserved
) {
433 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
434 atomic_sub((rqstp
->rq_reserved
- space
), &xprt
->xpt_reserved
);
435 rqstp
->rq_reserved
= space
;
437 svc_xprt_enqueue(xprt
);
440 EXPORT_SYMBOL_GPL(svc_reserve
);
442 static void svc_xprt_release(struct svc_rqst
*rqstp
)
444 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
446 rqstp
->rq_xprt
->xpt_ops
->xpo_release_rqst(rqstp
);
448 kfree(rqstp
->rq_deferred
);
449 rqstp
->rq_deferred
= NULL
;
451 svc_free_res_pages(rqstp
);
452 rqstp
->rq_res
.page_len
= 0;
453 rqstp
->rq_res
.page_base
= 0;
455 /* Reset response buffer and release
457 * But first, check that enough space was reserved
458 * for the reply, otherwise we have a bug!
460 if ((rqstp
->rq_res
.len
) > rqstp
->rq_reserved
)
461 printk(KERN_ERR
"RPC request reserved %d but used %d\n",
465 rqstp
->rq_res
.head
[0].iov_len
= 0;
466 svc_reserve(rqstp
, 0);
467 rqstp
->rq_xprt
= NULL
;
473 * External function to wake up a server waiting for data
474 * This really only makes sense for services like lockd
475 * which have exactly one thread anyway.
477 void svc_wake_up(struct svc_serv
*serv
)
479 struct svc_rqst
*rqstp
;
481 struct svc_pool
*pool
;
483 for (i
= 0; i
< serv
->sv_nrpools
; i
++) {
484 pool
= &serv
->sv_pools
[i
];
486 spin_lock_bh(&pool
->sp_lock
);
487 if (!list_empty(&pool
->sp_threads
)) {
488 rqstp
= list_entry(pool
->sp_threads
.next
,
491 dprintk("svc: daemon %p woken up.\n", rqstp
);
493 svc_thread_dequeue(pool, rqstp);
494 rqstp->rq_xprt = NULL;
496 wake_up(&rqstp
->rq_wait
);
498 spin_unlock_bh(&pool
->sp_lock
);
501 EXPORT_SYMBOL_GPL(svc_wake_up
);
503 int svc_port_is_privileged(struct sockaddr
*sin
)
505 switch (sin
->sa_family
) {
507 return ntohs(((struct sockaddr_in
*)sin
)->sin_port
)
510 return ntohs(((struct sockaddr_in6
*)sin
)->sin6_port
)
518 * Make sure that we don't have too many active connections. If we have,
519 * something must be dropped. It's not clear what will happen if we allow
520 * "too many" connections, but when dealing with network-facing software,
521 * we have to code defensively. Here we do that by imposing hard limits.
523 * There's no point in trying to do random drop here for DoS
524 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
525 * attacker can easily beat that.
527 * The only somewhat efficient mechanism would be if drop old
528 * connections from the same IP first. But right now we don't even
529 * record the client IP in svc_sock.
531 * single-threaded services that expect a lot of clients will probably
532 * need to set sv_maxconn to override the default value which is based
533 * on the number of threads
535 static void svc_check_conn_limits(struct svc_serv
*serv
)
537 unsigned int limit
= serv
->sv_maxconn
? serv
->sv_maxconn
:
538 (serv
->sv_nrthreads
+3) * 20;
540 if (serv
->sv_tmpcnt
> limit
) {
541 struct svc_xprt
*xprt
= NULL
;
542 spin_lock_bh(&serv
->sv_lock
);
543 if (!list_empty(&serv
->sv_tempsocks
)) {
544 /* Try to help the admin */
545 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
546 serv
->sv_name
, serv
->sv_maxconn
?
547 "max number of connections" :
548 "number of threads");
550 * Always select the oldest connection. It's not fair,
553 xprt
= list_entry(serv
->sv_tempsocks
.prev
,
556 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
559 spin_unlock_bh(&serv
->sv_lock
);
562 svc_xprt_enqueue(xprt
);
569 * Receive the next request on any transport. This code is carefully
570 * organised not to touch any cachelines in the shared svc_serv
571 * structure, only cachelines in the local svc_pool.
573 int svc_recv(struct svc_rqst
*rqstp
, long timeout
)
575 struct svc_xprt
*xprt
= NULL
;
576 struct svc_serv
*serv
= rqstp
->rq_server
;
577 struct svc_pool
*pool
= rqstp
->rq_pool
;
581 DECLARE_WAITQUEUE(wait
, current
);
584 dprintk("svc: server %p waiting for data (to = %ld)\n",
589 "svc_recv: service %p, transport not NULL!\n",
591 if (waitqueue_active(&rqstp
->rq_wait
))
593 "svc_recv: service %p, wait queue active!\n",
596 /* now allocate needed pages. If we get a failure, sleep briefly */
597 pages
= (serv
->sv_max_mesg
+ PAGE_SIZE
) / PAGE_SIZE
;
598 BUG_ON(pages
>= RPCSVC_MAXPAGES
);
599 for (i
= 0; i
< pages
; i
++)
600 while (rqstp
->rq_pages
[i
] == NULL
) {
601 struct page
*p
= alloc_page(GFP_KERNEL
);
603 set_current_state(TASK_INTERRUPTIBLE
);
604 if (signalled() || kthread_should_stop()) {
605 set_current_state(TASK_RUNNING
);
608 schedule_timeout(msecs_to_jiffies(500));
610 rqstp
->rq_pages
[i
] = p
;
612 rqstp
->rq_pages
[i
++] = NULL
; /* this might be seen in nfs_read_actor */
614 /* Make arg->head point to first page and arg->pages point to rest */
615 arg
= &rqstp
->rq_arg
;
616 arg
->head
[0].iov_base
= page_address(rqstp
->rq_pages
[0]);
617 arg
->head
[0].iov_len
= PAGE_SIZE
;
618 arg
->pages
= rqstp
->rq_pages
+ 1;
620 /* save at least one page for response */
621 arg
->page_len
= (pages
-2)*PAGE_SIZE
;
622 arg
->len
= (pages
-1)*PAGE_SIZE
;
623 arg
->tail
[0].iov_len
= 0;
627 if (signalled() || kthread_should_stop())
630 /* Normally we will wait up to 5 seconds for any required
631 * cache information to be provided.
633 rqstp
->rq_chandle
.thread_wait
= 5*HZ
;
635 spin_lock_bh(&pool
->sp_lock
);
636 xprt
= svc_xprt_dequeue(pool
);
638 rqstp
->rq_xprt
= xprt
;
641 /* As there is a shortage of threads and this request
642 * had to be queued, don't allow the thread to wait so
643 * long for cache updates.
645 rqstp
->rq_chandle
.thread_wait
= 1*HZ
;
647 /* No data pending. Go to sleep */
648 svc_thread_enqueue(pool
, rqstp
);
651 * We have to be able to interrupt this wait
652 * to bring down the daemons ...
654 set_current_state(TASK_INTERRUPTIBLE
);
657 * checking kthread_should_stop() here allows us to avoid
658 * locking and signalling when stopping kthreads that call
659 * svc_recv. If the thread has already been woken up, then
660 * we can exit here without sleeping. If not, then it
661 * it'll be woken up quickly during the schedule_timeout
663 if (kthread_should_stop()) {
664 set_current_state(TASK_RUNNING
);
665 spin_unlock_bh(&pool
->sp_lock
);
669 add_wait_queue(&rqstp
->rq_wait
, &wait
);
670 spin_unlock_bh(&pool
->sp_lock
);
672 time_left
= schedule_timeout(timeout
);
676 spin_lock_bh(&pool
->sp_lock
);
677 remove_wait_queue(&rqstp
->rq_wait
, &wait
);
679 pool
->sp_stats
.threads_timedout
++;
681 xprt
= rqstp
->rq_xprt
;
683 svc_thread_dequeue(pool
, rqstp
);
684 spin_unlock_bh(&pool
->sp_lock
);
685 dprintk("svc: server %p, no data yet\n", rqstp
);
686 if (signalled() || kthread_should_stop())
692 spin_unlock_bh(&pool
->sp_lock
);
695 if (test_bit(XPT_CLOSE
, &xprt
->xpt_flags
)) {
696 dprintk("svc_recv: found XPT_CLOSE\n");
697 svc_delete_xprt(xprt
);
698 /* Leave XPT_BUSY set on the dead xprt: */
701 if (test_bit(XPT_LISTENER
, &xprt
->xpt_flags
)) {
702 struct svc_xprt
*newxpt
;
703 newxpt
= xprt
->xpt_ops
->xpo_accept(xprt
);
706 * We know this module_get will succeed because the
707 * listener holds a reference too
709 __module_get(newxpt
->xpt_class
->xcl_owner
);
710 svc_check_conn_limits(xprt
->xpt_server
);
711 spin_lock_bh(&serv
->sv_lock
);
712 set_bit(XPT_TEMP
, &newxpt
->xpt_flags
);
713 list_add(&newxpt
->xpt_list
, &serv
->sv_tempsocks
);
715 if (serv
->sv_temptimer
.function
== NULL
) {
716 /* setup timer to age temp transports */
717 setup_timer(&serv
->sv_temptimer
,
719 (unsigned long)serv
);
720 mod_timer(&serv
->sv_temptimer
,
721 jiffies
+ svc_conn_age_period
* HZ
);
723 spin_unlock_bh(&serv
->sv_lock
);
724 svc_xprt_received(newxpt
);
726 } else if (xprt
->xpt_ops
->xpo_has_wspace(xprt
)) {
727 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
728 rqstp
, pool
->sp_id
, xprt
,
729 atomic_read(&xprt
->xpt_ref
.refcount
));
730 rqstp
->rq_deferred
= svc_deferred_dequeue(xprt
);
731 if (rqstp
->rq_deferred
)
732 len
= svc_deferred_recv(rqstp
);
734 len
= xprt
->xpt_ops
->xpo_recvfrom(rqstp
);
735 dprintk("svc: got len=%d\n", len
);
736 rqstp
->rq_reserved
= serv
->sv_max_mesg
;
737 atomic_add(rqstp
->rq_reserved
, &xprt
->xpt_reserved
);
739 svc_xprt_received(xprt
);
741 /* No data, incomplete (TCP) read, or accept() */
742 if (len
== 0 || len
== -EAGAIN
)
745 clear_bit(XPT_OLD
, &xprt
->xpt_flags
);
747 rqstp
->rq_secure
= svc_port_is_privileged(svc_addr(rqstp
));
748 rqstp
->rq_chandle
.defer
= svc_defer
;
751 serv
->sv_stats
->netcnt
++;
754 rqstp
->rq_res
.len
= 0;
755 svc_xprt_release(rqstp
);
758 EXPORT_SYMBOL_GPL(svc_recv
);
763 void svc_drop(struct svc_rqst
*rqstp
)
765 dprintk("svc: xprt %p dropped request\n", rqstp
->rq_xprt
);
766 svc_xprt_release(rqstp
);
768 EXPORT_SYMBOL_GPL(svc_drop
);
771 * Return reply to client.
773 int svc_send(struct svc_rqst
*rqstp
)
775 struct svc_xprt
*xprt
;
779 xprt
= rqstp
->rq_xprt
;
783 /* release the receive skb before sending the reply */
784 rqstp
->rq_xprt
->xpt_ops
->xpo_release_rqst(rqstp
);
786 /* calculate over-all length */
788 xb
->len
= xb
->head
[0].iov_len
+
792 /* Grab mutex to serialize outgoing data. */
793 mutex_lock(&xprt
->xpt_mutex
);
794 if (test_bit(XPT_DEAD
, &xprt
->xpt_flags
)
795 || test_bit(XPT_CLOSE
, &xprt
->xpt_flags
))
798 len
= xprt
->xpt_ops
->xpo_sendto(rqstp
);
799 mutex_unlock(&xprt
->xpt_mutex
);
800 rpc_wake_up(&xprt
->xpt_bc_pending
);
801 svc_xprt_release(rqstp
);
803 if (len
== -ECONNREFUSED
|| len
== -ENOTCONN
|| len
== -EAGAIN
)
809 * Timer function to close old temporary transports, using
810 * a mark-and-sweep algorithm.
812 static void svc_age_temp_xprts(unsigned long closure
)
814 struct svc_serv
*serv
= (struct svc_serv
*)closure
;
815 struct svc_xprt
*xprt
;
816 struct list_head
*le
, *next
;
817 LIST_HEAD(to_be_aged
);
819 dprintk("svc_age_temp_xprts\n");
821 if (!spin_trylock_bh(&serv
->sv_lock
)) {
822 /* busy, try again 1 sec later */
823 dprintk("svc_age_temp_xprts: busy\n");
824 mod_timer(&serv
->sv_temptimer
, jiffies
+ HZ
);
828 list_for_each_safe(le
, next
, &serv
->sv_tempsocks
) {
829 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
831 /* First time through, just mark it OLD. Second time
832 * through, close it. */
833 if (!test_and_set_bit(XPT_OLD
, &xprt
->xpt_flags
))
835 if (atomic_read(&xprt
->xpt_ref
.refcount
) > 1 ||
836 test_bit(XPT_BUSY
, &xprt
->xpt_flags
))
839 list_move(le
, &to_be_aged
);
840 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
841 set_bit(XPT_DETACHED
, &xprt
->xpt_flags
);
843 spin_unlock_bh(&serv
->sv_lock
);
845 while (!list_empty(&to_be_aged
)) {
846 le
= to_be_aged
.next
;
847 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
849 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
851 dprintk("queuing xprt %p for closing\n", xprt
);
853 /* a thread will dequeue and close it soon */
854 svc_xprt_enqueue(xprt
);
858 mod_timer(&serv
->sv_temptimer
, jiffies
+ svc_conn_age_period
* HZ
);
861 static void call_xpt_users(struct svc_xprt
*xprt
)
863 struct svc_xpt_user
*u
;
865 spin_lock(&xprt
->xpt_lock
);
866 while (!list_empty(&xprt
->xpt_users
)) {
867 u
= list_first_entry(&xprt
->xpt_users
, struct svc_xpt_user
, list
);
871 spin_unlock(&xprt
->xpt_lock
);
875 * Remove a dead transport
877 static void svc_delete_xprt(struct svc_xprt
*xprt
)
879 struct svc_serv
*serv
= xprt
->xpt_server
;
880 struct svc_deferred_req
*dr
;
882 /* Only do this once */
883 if (test_and_set_bit(XPT_DEAD
, &xprt
->xpt_flags
))
886 dprintk("svc: svc_delete_xprt(%p)\n", xprt
);
887 xprt
->xpt_ops
->xpo_detach(xprt
);
889 spin_lock_bh(&serv
->sv_lock
);
890 if (!test_and_set_bit(XPT_DETACHED
, &xprt
->xpt_flags
))
891 list_del_init(&xprt
->xpt_list
);
892 BUG_ON(!list_empty(&xprt
->xpt_ready
));
893 if (test_bit(XPT_TEMP
, &xprt
->xpt_flags
))
895 spin_unlock_bh(&serv
->sv_lock
);
897 while ((dr
= svc_deferred_dequeue(xprt
)) != NULL
)
900 call_xpt_users(xprt
);
904 void svc_close_xprt(struct svc_xprt
*xprt
)
906 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
907 if (test_and_set_bit(XPT_BUSY
, &xprt
->xpt_flags
))
908 /* someone else will have to effect the close */
911 * We expect svc_close_xprt() to work even when no threads are
912 * running (e.g., while configuring the server before starting
913 * any threads), so if the transport isn't busy, we delete
916 svc_delete_xprt(xprt
);
918 EXPORT_SYMBOL_GPL(svc_close_xprt
);
920 static void svc_close_list(struct list_head
*xprt_list
, struct net
*net
)
922 struct svc_xprt
*xprt
;
924 list_for_each_entry(xprt
, xprt_list
, xpt_list
) {
925 if (xprt
->xpt_net
!= net
)
927 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
928 set_bit(XPT_BUSY
, &xprt
->xpt_flags
);
932 static void svc_clear_pools(struct svc_serv
*serv
, struct net
*net
)
934 struct svc_pool
*pool
;
935 struct svc_xprt
*xprt
;
936 struct svc_xprt
*tmp
;
939 for (i
= 0; i
< serv
->sv_nrpools
; i
++) {
940 pool
= &serv
->sv_pools
[i
];
942 spin_lock_bh(&pool
->sp_lock
);
943 list_for_each_entry_safe(xprt
, tmp
, &pool
->sp_sockets
, xpt_ready
) {
944 if (xprt
->xpt_net
!= net
)
946 list_del_init(&xprt
->xpt_ready
);
948 spin_unlock_bh(&pool
->sp_lock
);
952 static void svc_clear_list(struct list_head
*xprt_list
, struct net
*net
)
954 struct svc_xprt
*xprt
;
955 struct svc_xprt
*tmp
;
957 list_for_each_entry_safe(xprt
, tmp
, xprt_list
, xpt_list
) {
958 if (xprt
->xpt_net
!= net
)
960 svc_delete_xprt(xprt
);
962 list_for_each_entry(xprt
, xprt_list
, xpt_list
)
963 BUG_ON(xprt
->xpt_net
== net
);
966 void svc_close_net(struct svc_serv
*serv
, struct net
*net
)
968 svc_close_list(&serv
->sv_tempsocks
, net
);
969 svc_close_list(&serv
->sv_permsocks
, net
);
971 svc_clear_pools(serv
, net
);
973 * At this point the sp_sockets lists will stay empty, since
974 * svc_xprt_enqueue will not add new entries without taking the
975 * sp_lock and checking XPT_BUSY.
977 svc_clear_list(&serv
->sv_tempsocks
, net
);
978 svc_clear_list(&serv
->sv_permsocks
, net
);
982 * Handle defer and revisit of requests
985 static void svc_revisit(struct cache_deferred_req
*dreq
, int too_many
)
987 struct svc_deferred_req
*dr
=
988 container_of(dreq
, struct svc_deferred_req
, handle
);
989 struct svc_xprt
*xprt
= dr
->xprt
;
991 spin_lock(&xprt
->xpt_lock
);
992 set_bit(XPT_DEFERRED
, &xprt
->xpt_flags
);
993 if (too_many
|| test_bit(XPT_DEAD
, &xprt
->xpt_flags
)) {
994 spin_unlock(&xprt
->xpt_lock
);
995 dprintk("revisit canceled\n");
1000 dprintk("revisit queued\n");
1002 list_add(&dr
->handle
.recent
, &xprt
->xpt_deferred
);
1003 spin_unlock(&xprt
->xpt_lock
);
1004 svc_xprt_enqueue(xprt
);
1009 * Save the request off for later processing. The request buffer looks
1012 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1014 * This code can only handle requests that consist of an xprt-header
1017 static struct cache_deferred_req
*svc_defer(struct cache_req
*req
)
1019 struct svc_rqst
*rqstp
= container_of(req
, struct svc_rqst
, rq_chandle
);
1020 struct svc_deferred_req
*dr
;
1022 if (rqstp
->rq_arg
.page_len
|| !rqstp
->rq_usedeferral
)
1023 return NULL
; /* if more than a page, give up FIXME */
1024 if (rqstp
->rq_deferred
) {
1025 dr
= rqstp
->rq_deferred
;
1026 rqstp
->rq_deferred
= NULL
;
1030 /* FIXME maybe discard if size too large */
1031 size
= sizeof(struct svc_deferred_req
) + rqstp
->rq_arg
.len
;
1032 dr
= kmalloc(size
, GFP_KERNEL
);
1036 dr
->handle
.owner
= rqstp
->rq_server
;
1037 dr
->prot
= rqstp
->rq_prot
;
1038 memcpy(&dr
->addr
, &rqstp
->rq_addr
, rqstp
->rq_addrlen
);
1039 dr
->addrlen
= rqstp
->rq_addrlen
;
1040 dr
->daddr
= rqstp
->rq_daddr
;
1041 dr
->argslen
= rqstp
->rq_arg
.len
>> 2;
1042 dr
->xprt_hlen
= rqstp
->rq_xprt_hlen
;
1044 /* back up head to the start of the buffer and copy */
1045 skip
= rqstp
->rq_arg
.len
- rqstp
->rq_arg
.head
[0].iov_len
;
1046 memcpy(dr
->args
, rqstp
->rq_arg
.head
[0].iov_base
- skip
,
1049 svc_xprt_get(rqstp
->rq_xprt
);
1050 dr
->xprt
= rqstp
->rq_xprt
;
1051 rqstp
->rq_dropme
= true;
1053 dr
->handle
.revisit
= svc_revisit
;
1058 * recv data from a deferred request into an active one
1060 static int svc_deferred_recv(struct svc_rqst
*rqstp
)
1062 struct svc_deferred_req
*dr
= rqstp
->rq_deferred
;
1064 /* setup iov_base past transport header */
1065 rqstp
->rq_arg
.head
[0].iov_base
= dr
->args
+ (dr
->xprt_hlen
>>2);
1066 /* The iov_len does not include the transport header bytes */
1067 rqstp
->rq_arg
.head
[0].iov_len
= (dr
->argslen
<<2) - dr
->xprt_hlen
;
1068 rqstp
->rq_arg
.page_len
= 0;
1069 /* The rq_arg.len includes the transport header bytes */
1070 rqstp
->rq_arg
.len
= dr
->argslen
<<2;
1071 rqstp
->rq_prot
= dr
->prot
;
1072 memcpy(&rqstp
->rq_addr
, &dr
->addr
, dr
->addrlen
);
1073 rqstp
->rq_addrlen
= dr
->addrlen
;
1074 /* Save off transport header len in case we get deferred again */
1075 rqstp
->rq_xprt_hlen
= dr
->xprt_hlen
;
1076 rqstp
->rq_daddr
= dr
->daddr
;
1077 rqstp
->rq_respages
= rqstp
->rq_pages
;
1078 return (dr
->argslen
<<2) - dr
->xprt_hlen
;
1082 static struct svc_deferred_req
*svc_deferred_dequeue(struct svc_xprt
*xprt
)
1084 struct svc_deferred_req
*dr
= NULL
;
1086 if (!test_bit(XPT_DEFERRED
, &xprt
->xpt_flags
))
1088 spin_lock(&xprt
->xpt_lock
);
1089 if (!list_empty(&xprt
->xpt_deferred
)) {
1090 dr
= list_entry(xprt
->xpt_deferred
.next
,
1091 struct svc_deferred_req
,
1093 list_del_init(&dr
->handle
.recent
);
1095 clear_bit(XPT_DEFERRED
, &xprt
->xpt_flags
);
1096 spin_unlock(&xprt
->xpt_lock
);
1101 * svc_find_xprt - find an RPC transport instance
1102 * @serv: pointer to svc_serv to search
1103 * @xcl_name: C string containing transport's class name
1104 * @net: owner net pointer
1105 * @af: Address family of transport's local address
1106 * @port: transport's IP port number
1108 * Return the transport instance pointer for the endpoint accepting
1109 * connections/peer traffic from the specified transport class,
1110 * address family and port.
1112 * Specifying 0 for the address family or port is effectively a
1113 * wild-card, and will result in matching the first transport in the
1114 * service's list that has a matching class name.
1116 struct svc_xprt
*svc_find_xprt(struct svc_serv
*serv
, const char *xcl_name
,
1117 struct net
*net
, const sa_family_t af
,
1118 const unsigned short port
)
1120 struct svc_xprt
*xprt
;
1121 struct svc_xprt
*found
= NULL
;
1123 /* Sanity check the args */
1124 if (serv
== NULL
|| xcl_name
== NULL
)
1127 spin_lock_bh(&serv
->sv_lock
);
1128 list_for_each_entry(xprt
, &serv
->sv_permsocks
, xpt_list
) {
1129 if (xprt
->xpt_net
!= net
)
1131 if (strcmp(xprt
->xpt_class
->xcl_name
, xcl_name
))
1133 if (af
!= AF_UNSPEC
&& af
!= xprt
->xpt_local
.ss_family
)
1135 if (port
!= 0 && port
!= svc_xprt_local_port(xprt
))
1141 spin_unlock_bh(&serv
->sv_lock
);
1144 EXPORT_SYMBOL_GPL(svc_find_xprt
);
1146 static int svc_one_xprt_name(const struct svc_xprt
*xprt
,
1147 char *pos
, int remaining
)
1151 len
= snprintf(pos
, remaining
, "%s %u\n",
1152 xprt
->xpt_class
->xcl_name
,
1153 svc_xprt_local_port(xprt
));
1154 if (len
>= remaining
)
1155 return -ENAMETOOLONG
;
1160 * svc_xprt_names - format a buffer with a list of transport names
1161 * @serv: pointer to an RPC service
1162 * @buf: pointer to a buffer to be filled in
1163 * @buflen: length of buffer to be filled in
1165 * Fills in @buf with a string containing a list of transport names,
1166 * each name terminated with '\n'.
1168 * Returns positive length of the filled-in string on success; otherwise
1169 * a negative errno value is returned if an error occurs.
1171 int svc_xprt_names(struct svc_serv
*serv
, char *buf
, const int buflen
)
1173 struct svc_xprt
*xprt
;
1177 /* Sanity check args */
1181 spin_lock_bh(&serv
->sv_lock
);
1185 list_for_each_entry(xprt
, &serv
->sv_permsocks
, xpt_list
) {
1186 len
= svc_one_xprt_name(xprt
, pos
, buflen
- totlen
);
1198 spin_unlock_bh(&serv
->sv_lock
);
1201 EXPORT_SYMBOL_GPL(svc_xprt_names
);
1204 /*----------------------------------------------------------------------------*/
1206 static void *svc_pool_stats_start(struct seq_file
*m
, loff_t
*pos
)
1208 unsigned int pidx
= (unsigned int)*pos
;
1209 struct svc_serv
*serv
= m
->private;
1211 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx
);
1214 return SEQ_START_TOKEN
;
1215 return (pidx
> serv
->sv_nrpools
? NULL
: &serv
->sv_pools
[pidx
-1]);
1218 static void *svc_pool_stats_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
1220 struct svc_pool
*pool
= p
;
1221 struct svc_serv
*serv
= m
->private;
1223 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos
);
1225 if (p
== SEQ_START_TOKEN
) {
1226 pool
= &serv
->sv_pools
[0];
1228 unsigned int pidx
= (pool
- &serv
->sv_pools
[0]);
1229 if (pidx
< serv
->sv_nrpools
-1)
1230 pool
= &serv
->sv_pools
[pidx
+1];
1238 static void svc_pool_stats_stop(struct seq_file
*m
, void *p
)
1242 static int svc_pool_stats_show(struct seq_file
*m
, void *p
)
1244 struct svc_pool
*pool
= p
;
1246 if (p
== SEQ_START_TOKEN
) {
1247 seq_puts(m
, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1251 seq_printf(m
, "%u %lu %lu %lu %lu\n",
1253 pool
->sp_stats
.packets
,
1254 pool
->sp_stats
.sockets_queued
,
1255 pool
->sp_stats
.threads_woken
,
1256 pool
->sp_stats
.threads_timedout
);
1261 static const struct seq_operations svc_pool_stats_seq_ops
= {
1262 .start
= svc_pool_stats_start
,
1263 .next
= svc_pool_stats_next
,
1264 .stop
= svc_pool_stats_stop
,
1265 .show
= svc_pool_stats_show
,
1268 int svc_pool_stats_open(struct svc_serv
*serv
, struct file
*file
)
1272 err
= seq_open(file
, &svc_pool_stats_seq_ops
);
1274 ((struct seq_file
*) file
->private_data
)->private = serv
;
1277 EXPORT_SYMBOL(svc_pool_stats_open
);
1279 /*----------------------------------------------------------------------------*/