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/addr.h>
14 #include <linux/sunrpc/stats.h>
15 #include <linux/sunrpc/svc_xprt.h>
16 #include <linux/sunrpc/svcsock.h>
17 #include <linux/sunrpc/xprt.h>
18 #include <linux/module.h>
19 #include <linux/netdevice.h>
20 #include <trace/events/sunrpc.h>
22 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
24 static unsigned int svc_rpc_per_connection_limit __read_mostly
;
25 module_param(svc_rpc_per_connection_limit
, uint
, 0644);
28 static struct svc_deferred_req
*svc_deferred_dequeue(struct svc_xprt
*xprt
);
29 static int svc_deferred_recv(struct svc_rqst
*rqstp
);
30 static struct cache_deferred_req
*svc_defer(struct cache_req
*req
);
31 static void svc_age_temp_xprts(struct timer_list
*t
);
32 static void svc_delete_xprt(struct svc_xprt
*xprt
);
34 /* apparently the "standard" is that clients close
35 * idle connections after 5 minutes, servers after
37 * http://www.connectathon.org/talks96/nfstcp.pdf
39 static int svc_conn_age_period
= 6*60;
41 /* List of registered transport classes */
42 static DEFINE_SPINLOCK(svc_xprt_class_lock
);
43 static LIST_HEAD(svc_xprt_class_list
);
45 /* SMP locking strategy:
47 * svc_pool->sp_lock protects most of the fields of that pool.
48 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
49 * when both need to be taken (rare), svc_serv->sv_lock is first.
50 * The "service mutex" protects svc_serv->sv_nrthread.
51 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
52 * and the ->sk_info_authunix cache.
54 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
55 * enqueued multiply. During normal transport processing this bit
56 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
57 * Providers should not manipulate this bit directly.
59 * Some flags can be set to certain values at any time
60 * providing that certain rules are followed:
63 * - Can be set or cleared at any time.
64 * - After a set, svc_xprt_enqueue must be called to enqueue
65 * the transport for processing.
66 * - After a clear, the transport must be read/accepted.
67 * If this succeeds, it must be set again.
69 * - Can set at any time. It is never cleared.
71 * - Can only be set while XPT_BUSY is held which ensures
72 * that no other thread will be using the transport or will
73 * try to set XPT_DEAD.
75 int svc_reg_xprt_class(struct svc_xprt_class
*xcl
)
77 struct svc_xprt_class
*cl
;
80 dprintk("svc: Adding svc transport class '%s'\n", xcl
->xcl_name
);
82 INIT_LIST_HEAD(&xcl
->xcl_list
);
83 spin_lock(&svc_xprt_class_lock
);
84 /* Make sure there isn't already a class with the same name */
85 list_for_each_entry(cl
, &svc_xprt_class_list
, xcl_list
) {
86 if (strcmp(xcl
->xcl_name
, cl
->xcl_name
) == 0)
89 list_add_tail(&xcl
->xcl_list
, &svc_xprt_class_list
);
92 spin_unlock(&svc_xprt_class_lock
);
95 EXPORT_SYMBOL_GPL(svc_reg_xprt_class
);
97 void svc_unreg_xprt_class(struct svc_xprt_class
*xcl
)
99 dprintk("svc: Removing svc transport class '%s'\n", xcl
->xcl_name
);
100 spin_lock(&svc_xprt_class_lock
);
101 list_del_init(&xcl
->xcl_list
);
102 spin_unlock(&svc_xprt_class_lock
);
104 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class
);
107 * Format the transport list for printing
109 int svc_print_xprts(char *buf
, int maxlen
)
111 struct svc_xprt_class
*xcl
;
116 spin_lock(&svc_xprt_class_lock
);
117 list_for_each_entry(xcl
, &svc_xprt_class_list
, xcl_list
) {
120 sprintf(tmpstr
, "%s %d\n", xcl
->xcl_name
, xcl
->xcl_max_payload
);
121 slen
= strlen(tmpstr
);
122 if (len
+ slen
> maxlen
)
127 spin_unlock(&svc_xprt_class_lock
);
132 static void svc_xprt_free(struct kref
*kref
)
134 struct svc_xprt
*xprt
=
135 container_of(kref
, struct svc_xprt
, xpt_ref
);
136 struct module
*owner
= xprt
->xpt_class
->xcl_owner
;
137 if (test_bit(XPT_CACHE_AUTH
, &xprt
->xpt_flags
))
138 svcauth_unix_info_release(xprt
);
139 put_net(xprt
->xpt_net
);
140 /* See comment on corresponding get in xs_setup_bc_tcp(): */
141 if (xprt
->xpt_bc_xprt
)
142 xprt_put(xprt
->xpt_bc_xprt
);
143 if (xprt
->xpt_bc_xps
)
144 xprt_switch_put(xprt
->xpt_bc_xps
);
145 xprt
->xpt_ops
->xpo_free(xprt
);
149 void svc_xprt_put(struct svc_xprt
*xprt
)
151 kref_put(&xprt
->xpt_ref
, svc_xprt_free
);
153 EXPORT_SYMBOL_GPL(svc_xprt_put
);
156 * Called by transport drivers to initialize the transport independent
157 * portion of the transport instance.
159 void svc_xprt_init(struct net
*net
, struct svc_xprt_class
*xcl
,
160 struct svc_xprt
*xprt
, struct svc_serv
*serv
)
162 memset(xprt
, 0, sizeof(*xprt
));
163 xprt
->xpt_class
= xcl
;
164 xprt
->xpt_ops
= xcl
->xcl_ops
;
165 kref_init(&xprt
->xpt_ref
);
166 xprt
->xpt_server
= serv
;
167 INIT_LIST_HEAD(&xprt
->xpt_list
);
168 INIT_LIST_HEAD(&xprt
->xpt_ready
);
169 INIT_LIST_HEAD(&xprt
->xpt_deferred
);
170 INIT_LIST_HEAD(&xprt
->xpt_users
);
171 mutex_init(&xprt
->xpt_mutex
);
172 spin_lock_init(&xprt
->xpt_lock
);
173 set_bit(XPT_BUSY
, &xprt
->xpt_flags
);
174 rpc_init_wait_queue(&xprt
->xpt_bc_pending
, "xpt_bc_pending");
175 xprt
->xpt_net
= get_net(net
);
177 EXPORT_SYMBOL_GPL(svc_xprt_init
);
179 static struct svc_xprt
*__svc_xpo_create(struct svc_xprt_class
*xcl
,
180 struct svc_serv
*serv
,
183 const unsigned short port
,
186 struct sockaddr_in sin
= {
187 .sin_family
= AF_INET
,
188 .sin_addr
.s_addr
= htonl(INADDR_ANY
),
189 .sin_port
= htons(port
),
191 #if IS_ENABLED(CONFIG_IPV6)
192 struct sockaddr_in6 sin6
= {
193 .sin6_family
= AF_INET6
,
194 .sin6_addr
= IN6ADDR_ANY_INIT
,
195 .sin6_port
= htons(port
),
198 struct sockaddr
*sap
;
203 sap
= (struct sockaddr
*)&sin
;
206 #if IS_ENABLED(CONFIG_IPV6)
208 sap
= (struct sockaddr
*)&sin6
;
213 return ERR_PTR(-EAFNOSUPPORT
);
216 return xcl
->xcl_ops
->xpo_create(serv
, net
, sap
, len
, flags
);
220 * svc_xprt_received conditionally queues the transport for processing
221 * by another thread. The caller must hold the XPT_BUSY bit and must
222 * not thereafter touch transport data.
224 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
225 * insufficient) data.
227 static void svc_xprt_received(struct svc_xprt
*xprt
)
229 if (!test_bit(XPT_BUSY
, &xprt
->xpt_flags
)) {
230 WARN_ONCE(1, "xprt=0x%p already busy!", xprt
);
234 /* As soon as we clear busy, the xprt could be closed and
235 * 'put', so we need a reference to call svc_enqueue_xprt with:
238 smp_mb__before_atomic();
239 clear_bit(XPT_BUSY
, &xprt
->xpt_flags
);
240 xprt
->xpt_server
->sv_ops
->svo_enqueue_xprt(xprt
);
244 void svc_add_new_perm_xprt(struct svc_serv
*serv
, struct svc_xprt
*new)
246 clear_bit(XPT_TEMP
, &new->xpt_flags
);
247 spin_lock_bh(&serv
->sv_lock
);
248 list_add(&new->xpt_list
, &serv
->sv_permsocks
);
249 spin_unlock_bh(&serv
->sv_lock
);
250 svc_xprt_received(new);
253 static int _svc_create_xprt(struct svc_serv
*serv
, const char *xprt_name
,
254 struct net
*net
, const int family
,
255 const unsigned short port
, int flags
)
257 struct svc_xprt_class
*xcl
;
259 spin_lock(&svc_xprt_class_lock
);
260 list_for_each_entry(xcl
, &svc_xprt_class_list
, xcl_list
) {
261 struct svc_xprt
*newxprt
;
262 unsigned short newport
;
264 if (strcmp(xprt_name
, xcl
->xcl_name
))
267 if (!try_module_get(xcl
->xcl_owner
))
270 spin_unlock(&svc_xprt_class_lock
);
271 newxprt
= __svc_xpo_create(xcl
, serv
, net
, family
, port
, flags
);
272 if (IS_ERR(newxprt
)) {
273 module_put(xcl
->xcl_owner
);
274 return PTR_ERR(newxprt
);
276 svc_add_new_perm_xprt(serv
, newxprt
);
277 newport
= svc_xprt_local_port(newxprt
);
281 spin_unlock(&svc_xprt_class_lock
);
282 /* This errno is exposed to user space. Provide a reasonable
283 * perror msg for a bad transport. */
284 return -EPROTONOSUPPORT
;
287 int svc_create_xprt(struct svc_serv
*serv
, const char *xprt_name
,
288 struct net
*net
, const int family
,
289 const unsigned short port
, int flags
)
293 dprintk("svc: creating transport %s[%d]\n", xprt_name
, port
);
294 err
= _svc_create_xprt(serv
, xprt_name
, net
, family
, port
, flags
);
295 if (err
== -EPROTONOSUPPORT
) {
296 request_module("svc%s", xprt_name
);
297 err
= _svc_create_xprt(serv
, xprt_name
, net
, family
, port
, flags
);
300 dprintk("svc: transport %s not found, err %d\n",
304 EXPORT_SYMBOL_GPL(svc_create_xprt
);
307 * Copy the local and remote xprt addresses to the rqstp structure
309 void svc_xprt_copy_addrs(struct svc_rqst
*rqstp
, struct svc_xprt
*xprt
)
311 memcpy(&rqstp
->rq_addr
, &xprt
->xpt_remote
, xprt
->xpt_remotelen
);
312 rqstp
->rq_addrlen
= xprt
->xpt_remotelen
;
315 * Destination address in request is needed for binding the
316 * source address in RPC replies/callbacks later.
318 memcpy(&rqstp
->rq_daddr
, &xprt
->xpt_local
, xprt
->xpt_locallen
);
319 rqstp
->rq_daddrlen
= xprt
->xpt_locallen
;
321 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs
);
324 * svc_print_addr - Format rq_addr field for printing
325 * @rqstp: svc_rqst struct containing address to print
326 * @buf: target buffer for formatted address
327 * @len: length of target buffer
330 char *svc_print_addr(struct svc_rqst
*rqstp
, char *buf
, size_t len
)
332 return __svc_print_addr(svc_addr(rqstp
), buf
, len
);
334 EXPORT_SYMBOL_GPL(svc_print_addr
);
336 static bool svc_xprt_slots_in_range(struct svc_xprt
*xprt
)
338 unsigned int limit
= svc_rpc_per_connection_limit
;
339 int nrqsts
= atomic_read(&xprt
->xpt_nr_rqsts
);
341 return limit
== 0 || (nrqsts
>= 0 && nrqsts
< limit
);
344 static bool svc_xprt_reserve_slot(struct svc_rqst
*rqstp
, struct svc_xprt
*xprt
)
346 if (!test_bit(RQ_DATA
, &rqstp
->rq_flags
)) {
347 if (!svc_xprt_slots_in_range(xprt
))
349 atomic_inc(&xprt
->xpt_nr_rqsts
);
350 set_bit(RQ_DATA
, &rqstp
->rq_flags
);
355 static void svc_xprt_release_slot(struct svc_rqst
*rqstp
)
357 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
358 if (test_and_clear_bit(RQ_DATA
, &rqstp
->rq_flags
)) {
359 atomic_dec(&xprt
->xpt_nr_rqsts
);
360 svc_xprt_enqueue(xprt
);
364 static bool svc_xprt_has_something_to_do(struct svc_xprt
*xprt
)
366 if (xprt
->xpt_flags
& ((1<<XPT_CONN
)|(1<<XPT_CLOSE
)))
368 if (xprt
->xpt_flags
& ((1<<XPT_DATA
)|(1<<XPT_DEFERRED
))) {
369 if (xprt
->xpt_ops
->xpo_has_wspace(xprt
) &&
370 svc_xprt_slots_in_range(xprt
))
372 trace_svc_xprt_no_write_space(xprt
);
378 void svc_xprt_do_enqueue(struct svc_xprt
*xprt
)
380 struct svc_pool
*pool
;
381 struct svc_rqst
*rqstp
= NULL
;
384 if (!svc_xprt_has_something_to_do(xprt
))
387 /* Mark transport as busy. It will remain in this state until
388 * the provider calls svc_xprt_received. We update XPT_BUSY
389 * atomically because it also guards against trying to enqueue
390 * the transport twice.
392 if (test_and_set_bit(XPT_BUSY
, &xprt
->xpt_flags
)) {
393 /* Don't enqueue transport while already enqueued */
394 dprintk("svc: transport %p busy, not enqueued\n", xprt
);
399 pool
= svc_pool_for_cpu(xprt
->xpt_server
, cpu
);
401 atomic_long_inc(&pool
->sp_stats
.packets
);
403 dprintk("svc: transport %p put into queue\n", xprt
);
404 spin_lock_bh(&pool
->sp_lock
);
405 list_add_tail(&xprt
->xpt_ready
, &pool
->sp_sockets
);
406 pool
->sp_stats
.sockets_queued
++;
407 spin_unlock_bh(&pool
->sp_lock
);
409 /* find a thread for this xprt */
411 list_for_each_entry_rcu(rqstp
, &pool
->sp_all_threads
, rq_all
) {
412 if (test_and_set_bit(RQ_BUSY
, &rqstp
->rq_flags
))
414 atomic_long_inc(&pool
->sp_stats
.threads_woken
);
415 wake_up_process(rqstp
->rq_task
);
418 set_bit(SP_CONGESTED
, &pool
->sp_flags
);
424 trace_svc_xprt_do_enqueue(xprt
, rqstp
);
426 EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue
);
429 * Queue up a transport with data pending. If there are idle nfsd
430 * processes, wake 'em up.
433 void svc_xprt_enqueue(struct svc_xprt
*xprt
)
435 if (test_bit(XPT_BUSY
, &xprt
->xpt_flags
))
437 xprt
->xpt_server
->sv_ops
->svo_enqueue_xprt(xprt
);
439 EXPORT_SYMBOL_GPL(svc_xprt_enqueue
);
442 * Dequeue the first transport, if there is one.
444 static struct svc_xprt
*svc_xprt_dequeue(struct svc_pool
*pool
)
446 struct svc_xprt
*xprt
= NULL
;
448 if (list_empty(&pool
->sp_sockets
))
451 spin_lock_bh(&pool
->sp_lock
);
452 if (likely(!list_empty(&pool
->sp_sockets
))) {
453 xprt
= list_first_entry(&pool
->sp_sockets
,
454 struct svc_xprt
, xpt_ready
);
455 list_del_init(&xprt
->xpt_ready
);
458 dprintk("svc: transport %p dequeued, inuse=%d\n",
459 xprt
, kref_read(&xprt
->xpt_ref
));
461 spin_unlock_bh(&pool
->sp_lock
);
463 trace_svc_xprt_dequeue(xprt
);
468 * svc_reserve - change the space reserved for the reply to a request.
469 * @rqstp: The request in question
470 * @space: new max space to reserve
472 * Each request reserves some space on the output queue of the transport
473 * to make sure the reply fits. This function reduces that reserved
474 * space to be the amount of space used already, plus @space.
477 void svc_reserve(struct svc_rqst
*rqstp
, int space
)
479 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
481 space
+= rqstp
->rq_res
.head
[0].iov_len
;
483 if (xprt
&& space
< rqstp
->rq_reserved
) {
484 atomic_sub((rqstp
->rq_reserved
- space
), &xprt
->xpt_reserved
);
485 rqstp
->rq_reserved
= space
;
487 svc_xprt_enqueue(xprt
);
490 EXPORT_SYMBOL_GPL(svc_reserve
);
492 static void svc_xprt_release(struct svc_rqst
*rqstp
)
494 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
496 rqstp
->rq_xprt
->xpt_ops
->xpo_release_rqst(rqstp
);
498 kfree(rqstp
->rq_deferred
);
499 rqstp
->rq_deferred
= NULL
;
501 svc_free_res_pages(rqstp
);
502 rqstp
->rq_res
.page_len
= 0;
503 rqstp
->rq_res
.page_base
= 0;
505 /* Reset response buffer and release
507 * But first, check that enough space was reserved
508 * for the reply, otherwise we have a bug!
510 if ((rqstp
->rq_res
.len
) > rqstp
->rq_reserved
)
511 printk(KERN_ERR
"RPC request reserved %d but used %d\n",
515 rqstp
->rq_res
.head
[0].iov_len
= 0;
516 svc_reserve(rqstp
, 0);
517 svc_xprt_release_slot(rqstp
);
518 rqstp
->rq_xprt
= NULL
;
523 * Some svc_serv's will have occasional work to do, even when a xprt is not
524 * waiting to be serviced. This function is there to "kick" a task in one of
525 * those services so that it can wake up and do that work. Note that we only
526 * bother with pool 0 as we don't need to wake up more than one thread for
529 void svc_wake_up(struct svc_serv
*serv
)
531 struct svc_rqst
*rqstp
;
532 struct svc_pool
*pool
;
534 pool
= &serv
->sv_pools
[0];
537 list_for_each_entry_rcu(rqstp
, &pool
->sp_all_threads
, rq_all
) {
538 /* skip any that aren't queued */
539 if (test_bit(RQ_BUSY
, &rqstp
->rq_flags
))
542 dprintk("svc: daemon %p woken up.\n", rqstp
);
543 wake_up_process(rqstp
->rq_task
);
544 trace_svc_wake_up(rqstp
->rq_task
->pid
);
549 /* No free entries available */
550 set_bit(SP_TASK_PENDING
, &pool
->sp_flags
);
552 trace_svc_wake_up(0);
554 EXPORT_SYMBOL_GPL(svc_wake_up
);
556 int svc_port_is_privileged(struct sockaddr
*sin
)
558 switch (sin
->sa_family
) {
560 return ntohs(((struct sockaddr_in
*)sin
)->sin_port
)
563 return ntohs(((struct sockaddr_in6
*)sin
)->sin6_port
)
571 * Make sure that we don't have too many active connections. If we have,
572 * something must be dropped. It's not clear what will happen if we allow
573 * "too many" connections, but when dealing with network-facing software,
574 * we have to code defensively. Here we do that by imposing hard limits.
576 * There's no point in trying to do random drop here for DoS
577 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
578 * attacker can easily beat that.
580 * The only somewhat efficient mechanism would be if drop old
581 * connections from the same IP first. But right now we don't even
582 * record the client IP in svc_sock.
584 * single-threaded services that expect a lot of clients will probably
585 * need to set sv_maxconn to override the default value which is based
586 * on the number of threads
588 static void svc_check_conn_limits(struct svc_serv
*serv
)
590 unsigned int limit
= serv
->sv_maxconn
? serv
->sv_maxconn
:
591 (serv
->sv_nrthreads
+3) * 20;
593 if (serv
->sv_tmpcnt
> limit
) {
594 struct svc_xprt
*xprt
= NULL
;
595 spin_lock_bh(&serv
->sv_lock
);
596 if (!list_empty(&serv
->sv_tempsocks
)) {
597 /* Try to help the admin */
598 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
599 serv
->sv_name
, serv
->sv_maxconn
?
600 "max number of connections" :
601 "number of threads");
603 * Always select the oldest connection. It's not fair,
606 xprt
= list_entry(serv
->sv_tempsocks
.prev
,
609 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
612 spin_unlock_bh(&serv
->sv_lock
);
615 svc_xprt_enqueue(xprt
);
621 static int svc_alloc_arg(struct svc_rqst
*rqstp
)
623 struct svc_serv
*serv
= rqstp
->rq_server
;
628 /* now allocate needed pages. If we get a failure, sleep briefly */
629 pages
= (serv
->sv_max_mesg
+ 2 * PAGE_SIZE
) >> PAGE_SHIFT
;
630 if (pages
> RPCSVC_MAXPAGES
) {
631 pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n",
632 pages
, RPCSVC_MAXPAGES
);
633 /* use as many pages as possible */
634 pages
= RPCSVC_MAXPAGES
;
636 for (i
= 0; i
< pages
; i
++)
637 while (rqstp
->rq_pages
[i
] == NULL
) {
638 struct page
*p
= alloc_page(GFP_KERNEL
);
640 set_current_state(TASK_INTERRUPTIBLE
);
641 if (signalled() || kthread_should_stop()) {
642 set_current_state(TASK_RUNNING
);
645 schedule_timeout(msecs_to_jiffies(500));
647 rqstp
->rq_pages
[i
] = p
;
649 rqstp
->rq_page_end
= &rqstp
->rq_pages
[i
];
650 rqstp
->rq_pages
[i
++] = NULL
; /* this might be seen in nfs_read_actor */
652 /* Make arg->head point to first page and arg->pages point to rest */
653 arg
= &rqstp
->rq_arg
;
654 arg
->head
[0].iov_base
= page_address(rqstp
->rq_pages
[0]);
655 arg
->head
[0].iov_len
= PAGE_SIZE
;
656 arg
->pages
= rqstp
->rq_pages
+ 1;
658 /* save at least one page for response */
659 arg
->page_len
= (pages
-2)*PAGE_SIZE
;
660 arg
->len
= (pages
-1)*PAGE_SIZE
;
661 arg
->tail
[0].iov_len
= 0;
666 rqst_should_sleep(struct svc_rqst
*rqstp
)
668 struct svc_pool
*pool
= rqstp
->rq_pool
;
670 /* did someone call svc_wake_up? */
671 if (test_and_clear_bit(SP_TASK_PENDING
, &pool
->sp_flags
))
674 /* was a socket queued? */
675 if (!list_empty(&pool
->sp_sockets
))
678 /* are we shutting down? */
679 if (signalled() || kthread_should_stop())
682 /* are we freezing? */
683 if (freezing(current
))
689 static struct svc_xprt
*svc_get_next_xprt(struct svc_rqst
*rqstp
, long timeout
)
691 struct svc_pool
*pool
= rqstp
->rq_pool
;
694 /* rq_xprt should be clear on entry */
695 WARN_ON_ONCE(rqstp
->rq_xprt
);
697 rqstp
->rq_xprt
= svc_xprt_dequeue(pool
);
702 * We have to be able to interrupt this wait
703 * to bring down the daemons ...
705 set_current_state(TASK_INTERRUPTIBLE
);
706 smp_mb__before_atomic();
707 clear_bit(SP_CONGESTED
, &pool
->sp_flags
);
708 clear_bit(RQ_BUSY
, &rqstp
->rq_flags
);
709 smp_mb__after_atomic();
711 if (likely(rqst_should_sleep(rqstp
)))
712 time_left
= schedule_timeout(timeout
);
714 __set_current_state(TASK_RUNNING
);
718 set_bit(RQ_BUSY
, &rqstp
->rq_flags
);
719 smp_mb__after_atomic();
720 rqstp
->rq_xprt
= svc_xprt_dequeue(pool
);
725 atomic_long_inc(&pool
->sp_stats
.threads_timedout
);
727 if (signalled() || kthread_should_stop())
728 return ERR_PTR(-EINTR
);
729 return ERR_PTR(-EAGAIN
);
731 /* Normally we will wait up to 5 seconds for any required
732 * cache information to be provided.
734 if (!test_bit(SP_CONGESTED
, &pool
->sp_flags
))
735 rqstp
->rq_chandle
.thread_wait
= 5*HZ
;
737 rqstp
->rq_chandle
.thread_wait
= 1*HZ
;
738 return rqstp
->rq_xprt
;
741 static void svc_add_new_temp_xprt(struct svc_serv
*serv
, struct svc_xprt
*newxpt
)
743 spin_lock_bh(&serv
->sv_lock
);
744 set_bit(XPT_TEMP
, &newxpt
->xpt_flags
);
745 list_add(&newxpt
->xpt_list
, &serv
->sv_tempsocks
);
747 if (serv
->sv_temptimer
.function
== NULL
) {
748 /* setup timer to age temp transports */
749 serv
->sv_temptimer
.function
= svc_age_temp_xprts
;
750 mod_timer(&serv
->sv_temptimer
,
751 jiffies
+ svc_conn_age_period
* HZ
);
753 spin_unlock_bh(&serv
->sv_lock
);
754 svc_xprt_received(newxpt
);
757 static int svc_handle_xprt(struct svc_rqst
*rqstp
, struct svc_xprt
*xprt
)
759 struct svc_serv
*serv
= rqstp
->rq_server
;
762 if (test_bit(XPT_CLOSE
, &xprt
->xpt_flags
)) {
763 dprintk("svc_recv: found XPT_CLOSE\n");
764 if (test_and_clear_bit(XPT_KILL_TEMP
, &xprt
->xpt_flags
))
765 xprt
->xpt_ops
->xpo_kill_temp_xprt(xprt
);
766 svc_delete_xprt(xprt
);
767 /* Leave XPT_BUSY set on the dead xprt: */
770 if (test_bit(XPT_LISTENER
, &xprt
->xpt_flags
)) {
771 struct svc_xprt
*newxpt
;
773 * We know this module_get will succeed because the
774 * listener holds a reference too
776 __module_get(xprt
->xpt_class
->xcl_owner
);
777 svc_check_conn_limits(xprt
->xpt_server
);
778 newxpt
= xprt
->xpt_ops
->xpo_accept(xprt
);
780 svc_add_new_temp_xprt(serv
, newxpt
);
782 module_put(xprt
->xpt_class
->xcl_owner
);
783 } else if (svc_xprt_reserve_slot(rqstp
, xprt
)) {
784 /* XPT_DATA|XPT_DEFERRED case: */
785 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
786 rqstp
, rqstp
->rq_pool
->sp_id
, xprt
,
787 kref_read(&xprt
->xpt_ref
));
788 rqstp
->rq_deferred
= svc_deferred_dequeue(xprt
);
789 if (rqstp
->rq_deferred
)
790 len
= svc_deferred_recv(rqstp
);
792 len
= xprt
->xpt_ops
->xpo_recvfrom(rqstp
);
793 dprintk("svc: got len=%d\n", len
);
794 rqstp
->rq_reserved
= serv
->sv_max_mesg
;
795 atomic_add(rqstp
->rq_reserved
, &xprt
->xpt_reserved
);
797 /* clear XPT_BUSY: */
798 svc_xprt_received(xprt
);
800 trace_svc_handle_xprt(xprt
, len
);
805 * Receive the next request on any transport. This code is carefully
806 * organised not to touch any cachelines in the shared svc_serv
807 * structure, only cachelines in the local svc_pool.
809 int svc_recv(struct svc_rqst
*rqstp
, long timeout
)
811 struct svc_xprt
*xprt
= NULL
;
812 struct svc_serv
*serv
= rqstp
->rq_server
;
815 dprintk("svc: server %p waiting for data (to = %ld)\n",
820 "svc_recv: service %p, transport not NULL!\n",
823 err
= svc_alloc_arg(rqstp
);
830 if (signalled() || kthread_should_stop())
833 xprt
= svc_get_next_xprt(rqstp
, timeout
);
839 len
= svc_handle_xprt(rqstp
, xprt
);
841 /* No data, incomplete (TCP) read, or accept() */
846 clear_bit(XPT_OLD
, &xprt
->xpt_flags
);
848 if (xprt
->xpt_ops
->xpo_secure_port(rqstp
))
849 set_bit(RQ_SECURE
, &rqstp
->rq_flags
);
851 clear_bit(RQ_SECURE
, &rqstp
->rq_flags
);
852 rqstp
->rq_chandle
.defer
= svc_defer
;
853 rqstp
->rq_xid
= svc_getu32(&rqstp
->rq_arg
.head
[0]);
856 serv
->sv_stats
->netcnt
++;
857 trace_svc_recv(rqstp
, len
);
860 rqstp
->rq_res
.len
= 0;
861 svc_xprt_release(rqstp
);
863 trace_svc_recv(rqstp
, err
);
866 EXPORT_SYMBOL_GPL(svc_recv
);
871 void svc_drop(struct svc_rqst
*rqstp
)
873 trace_svc_drop(rqstp
);
874 dprintk("svc: xprt %p dropped request\n", rqstp
->rq_xprt
);
875 svc_xprt_release(rqstp
);
877 EXPORT_SYMBOL_GPL(svc_drop
);
880 * Return reply to client.
882 int svc_send(struct svc_rqst
*rqstp
)
884 struct svc_xprt
*xprt
;
888 xprt
= rqstp
->rq_xprt
;
892 /* release the receive skb before sending the reply */
893 rqstp
->rq_xprt
->xpt_ops
->xpo_release_rqst(rqstp
);
895 /* calculate over-all length */
897 xb
->len
= xb
->head
[0].iov_len
+
901 /* Grab mutex to serialize outgoing data. */
902 mutex_lock(&xprt
->xpt_mutex
);
903 if (test_bit(XPT_DEAD
, &xprt
->xpt_flags
)
904 || test_bit(XPT_CLOSE
, &xprt
->xpt_flags
))
907 len
= xprt
->xpt_ops
->xpo_sendto(rqstp
);
908 mutex_unlock(&xprt
->xpt_mutex
);
909 rpc_wake_up(&xprt
->xpt_bc_pending
);
910 svc_xprt_release(rqstp
);
912 if (len
== -ECONNREFUSED
|| len
== -ENOTCONN
|| len
== -EAGAIN
)
915 trace_svc_send(rqstp
, len
);
920 * Timer function to close old temporary transports, using
921 * a mark-and-sweep algorithm.
923 static void svc_age_temp_xprts(struct timer_list
*t
)
925 struct svc_serv
*serv
= from_timer(serv
, t
, sv_temptimer
);
926 struct svc_xprt
*xprt
;
927 struct list_head
*le
, *next
;
929 dprintk("svc_age_temp_xprts\n");
931 if (!spin_trylock_bh(&serv
->sv_lock
)) {
932 /* busy, try again 1 sec later */
933 dprintk("svc_age_temp_xprts: busy\n");
934 mod_timer(&serv
->sv_temptimer
, jiffies
+ HZ
);
938 list_for_each_safe(le
, next
, &serv
->sv_tempsocks
) {
939 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
941 /* First time through, just mark it OLD. Second time
942 * through, close it. */
943 if (!test_and_set_bit(XPT_OLD
, &xprt
->xpt_flags
))
945 if (kref_read(&xprt
->xpt_ref
) > 1 ||
946 test_bit(XPT_BUSY
, &xprt
->xpt_flags
))
949 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
950 dprintk("queuing xprt %p for closing\n", xprt
);
952 /* a thread will dequeue and close it soon */
953 svc_xprt_enqueue(xprt
);
955 spin_unlock_bh(&serv
->sv_lock
);
957 mod_timer(&serv
->sv_temptimer
, jiffies
+ svc_conn_age_period
* HZ
);
960 /* Close temporary transports whose xpt_local matches server_addr immediately
961 * instead of waiting for them to be picked up by the timer.
963 * This is meant to be called from a notifier_block that runs when an ip
964 * address is deleted.
966 void svc_age_temp_xprts_now(struct svc_serv
*serv
, struct sockaddr
*server_addr
)
968 struct svc_xprt
*xprt
;
969 struct list_head
*le
, *next
;
970 LIST_HEAD(to_be_closed
);
972 spin_lock_bh(&serv
->sv_lock
);
973 list_for_each_safe(le
, next
, &serv
->sv_tempsocks
) {
974 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
975 if (rpc_cmp_addr(server_addr
, (struct sockaddr
*)
977 dprintk("svc_age_temp_xprts_now: found %p\n", xprt
);
978 list_move(le
, &to_be_closed
);
981 spin_unlock_bh(&serv
->sv_lock
);
983 while (!list_empty(&to_be_closed
)) {
984 le
= to_be_closed
.next
;
986 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
987 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
988 set_bit(XPT_KILL_TEMP
, &xprt
->xpt_flags
);
989 dprintk("svc_age_temp_xprts_now: queuing xprt %p for closing\n",
991 svc_xprt_enqueue(xprt
);
994 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now
);
996 static void call_xpt_users(struct svc_xprt
*xprt
)
998 struct svc_xpt_user
*u
;
1000 spin_lock(&xprt
->xpt_lock
);
1001 while (!list_empty(&xprt
->xpt_users
)) {
1002 u
= list_first_entry(&xprt
->xpt_users
, struct svc_xpt_user
, list
);
1003 list_del_init(&u
->list
);
1006 spin_unlock(&xprt
->xpt_lock
);
1010 * Remove a dead transport
1012 static void svc_delete_xprt(struct svc_xprt
*xprt
)
1014 struct svc_serv
*serv
= xprt
->xpt_server
;
1015 struct svc_deferred_req
*dr
;
1017 /* Only do this once */
1018 if (test_and_set_bit(XPT_DEAD
, &xprt
->xpt_flags
))
1021 dprintk("svc: svc_delete_xprt(%p)\n", xprt
);
1022 xprt
->xpt_ops
->xpo_detach(xprt
);
1024 spin_lock_bh(&serv
->sv_lock
);
1025 list_del_init(&xprt
->xpt_list
);
1026 WARN_ON_ONCE(!list_empty(&xprt
->xpt_ready
));
1027 if (test_bit(XPT_TEMP
, &xprt
->xpt_flags
))
1029 spin_unlock_bh(&serv
->sv_lock
);
1031 while ((dr
= svc_deferred_dequeue(xprt
)) != NULL
)
1034 call_xpt_users(xprt
);
1038 void svc_close_xprt(struct svc_xprt
*xprt
)
1040 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
1041 if (test_and_set_bit(XPT_BUSY
, &xprt
->xpt_flags
))
1042 /* someone else will have to effect the close */
1045 * We expect svc_close_xprt() to work even when no threads are
1046 * running (e.g., while configuring the server before starting
1047 * any threads), so if the transport isn't busy, we delete
1050 svc_delete_xprt(xprt
);
1052 EXPORT_SYMBOL_GPL(svc_close_xprt
);
1054 static int svc_close_list(struct svc_serv
*serv
, struct list_head
*xprt_list
, struct net
*net
)
1056 struct svc_xprt
*xprt
;
1059 spin_lock(&serv
->sv_lock
);
1060 list_for_each_entry(xprt
, xprt_list
, xpt_list
) {
1061 if (xprt
->xpt_net
!= net
)
1064 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
1065 svc_xprt_enqueue(xprt
);
1067 spin_unlock(&serv
->sv_lock
);
1071 static struct svc_xprt
*svc_dequeue_net(struct svc_serv
*serv
, struct net
*net
)
1073 struct svc_pool
*pool
;
1074 struct svc_xprt
*xprt
;
1075 struct svc_xprt
*tmp
;
1078 for (i
= 0; i
< serv
->sv_nrpools
; i
++) {
1079 pool
= &serv
->sv_pools
[i
];
1081 spin_lock_bh(&pool
->sp_lock
);
1082 list_for_each_entry_safe(xprt
, tmp
, &pool
->sp_sockets
, xpt_ready
) {
1083 if (xprt
->xpt_net
!= net
)
1085 list_del_init(&xprt
->xpt_ready
);
1086 spin_unlock_bh(&pool
->sp_lock
);
1089 spin_unlock_bh(&pool
->sp_lock
);
1094 static void svc_clean_up_xprts(struct svc_serv
*serv
, struct net
*net
)
1096 struct svc_xprt
*xprt
;
1098 while ((xprt
= svc_dequeue_net(serv
, net
))) {
1099 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
1100 svc_delete_xprt(xprt
);
1105 * Server threads may still be running (especially in the case where the
1106 * service is still running in other network namespaces).
1108 * So we shut down sockets the same way we would on a running server, by
1109 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do
1110 * the close. In the case there are no such other threads,
1111 * threads running, svc_clean_up_xprts() does a simple version of a
1112 * server's main event loop, and in the case where there are other
1113 * threads, we may need to wait a little while and then check again to
1114 * see if they're done.
1116 void svc_close_net(struct svc_serv
*serv
, struct net
*net
)
1120 while (svc_close_list(serv
, &serv
->sv_permsocks
, net
) +
1121 svc_close_list(serv
, &serv
->sv_tempsocks
, net
)) {
1123 svc_clean_up_xprts(serv
, net
);
1129 * Handle defer and revisit of requests
1132 static void svc_revisit(struct cache_deferred_req
*dreq
, int too_many
)
1134 struct svc_deferred_req
*dr
=
1135 container_of(dreq
, struct svc_deferred_req
, handle
);
1136 struct svc_xprt
*xprt
= dr
->xprt
;
1138 spin_lock(&xprt
->xpt_lock
);
1139 set_bit(XPT_DEFERRED
, &xprt
->xpt_flags
);
1140 if (too_many
|| test_bit(XPT_DEAD
, &xprt
->xpt_flags
)) {
1141 spin_unlock(&xprt
->xpt_lock
);
1142 dprintk("revisit canceled\n");
1144 trace_svc_drop_deferred(dr
);
1148 dprintk("revisit queued\n");
1150 list_add(&dr
->handle
.recent
, &xprt
->xpt_deferred
);
1151 spin_unlock(&xprt
->xpt_lock
);
1152 svc_xprt_enqueue(xprt
);
1157 * Save the request off for later processing. The request buffer looks
1160 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1162 * This code can only handle requests that consist of an xprt-header
1165 static struct cache_deferred_req
*svc_defer(struct cache_req
*req
)
1167 struct svc_rqst
*rqstp
= container_of(req
, struct svc_rqst
, rq_chandle
);
1168 struct svc_deferred_req
*dr
;
1170 if (rqstp
->rq_arg
.page_len
|| !test_bit(RQ_USEDEFERRAL
, &rqstp
->rq_flags
))
1171 return NULL
; /* if more than a page, give up FIXME */
1172 if (rqstp
->rq_deferred
) {
1173 dr
= rqstp
->rq_deferred
;
1174 rqstp
->rq_deferred
= NULL
;
1178 /* FIXME maybe discard if size too large */
1179 size
= sizeof(struct svc_deferred_req
) + rqstp
->rq_arg
.len
;
1180 dr
= kmalloc(size
, GFP_KERNEL
);
1184 dr
->handle
.owner
= rqstp
->rq_server
;
1185 dr
->prot
= rqstp
->rq_prot
;
1186 memcpy(&dr
->addr
, &rqstp
->rq_addr
, rqstp
->rq_addrlen
);
1187 dr
->addrlen
= rqstp
->rq_addrlen
;
1188 dr
->daddr
= rqstp
->rq_daddr
;
1189 dr
->argslen
= rqstp
->rq_arg
.len
>> 2;
1190 dr
->xprt_hlen
= rqstp
->rq_xprt_hlen
;
1192 /* back up head to the start of the buffer and copy */
1193 skip
= rqstp
->rq_arg
.len
- rqstp
->rq_arg
.head
[0].iov_len
;
1194 memcpy(dr
->args
, rqstp
->rq_arg
.head
[0].iov_base
- skip
,
1197 svc_xprt_get(rqstp
->rq_xprt
);
1198 dr
->xprt
= rqstp
->rq_xprt
;
1199 set_bit(RQ_DROPME
, &rqstp
->rq_flags
);
1201 dr
->handle
.revisit
= svc_revisit
;
1202 trace_svc_defer(rqstp
);
1207 * recv data from a deferred request into an active one
1209 static int svc_deferred_recv(struct svc_rqst
*rqstp
)
1211 struct svc_deferred_req
*dr
= rqstp
->rq_deferred
;
1213 /* setup iov_base past transport header */
1214 rqstp
->rq_arg
.head
[0].iov_base
= dr
->args
+ (dr
->xprt_hlen
>>2);
1215 /* The iov_len does not include the transport header bytes */
1216 rqstp
->rq_arg
.head
[0].iov_len
= (dr
->argslen
<<2) - dr
->xprt_hlen
;
1217 rqstp
->rq_arg
.page_len
= 0;
1218 /* The rq_arg.len includes the transport header bytes */
1219 rqstp
->rq_arg
.len
= dr
->argslen
<<2;
1220 rqstp
->rq_prot
= dr
->prot
;
1221 memcpy(&rqstp
->rq_addr
, &dr
->addr
, dr
->addrlen
);
1222 rqstp
->rq_addrlen
= dr
->addrlen
;
1223 /* Save off transport header len in case we get deferred again */
1224 rqstp
->rq_xprt_hlen
= dr
->xprt_hlen
;
1225 rqstp
->rq_daddr
= dr
->daddr
;
1226 rqstp
->rq_respages
= rqstp
->rq_pages
;
1227 return (dr
->argslen
<<2) - dr
->xprt_hlen
;
1231 static struct svc_deferred_req
*svc_deferred_dequeue(struct svc_xprt
*xprt
)
1233 struct svc_deferred_req
*dr
= NULL
;
1235 if (!test_bit(XPT_DEFERRED
, &xprt
->xpt_flags
))
1237 spin_lock(&xprt
->xpt_lock
);
1238 if (!list_empty(&xprt
->xpt_deferred
)) {
1239 dr
= list_entry(xprt
->xpt_deferred
.next
,
1240 struct svc_deferred_req
,
1242 list_del_init(&dr
->handle
.recent
);
1243 trace_svc_revisit_deferred(dr
);
1245 clear_bit(XPT_DEFERRED
, &xprt
->xpt_flags
);
1246 spin_unlock(&xprt
->xpt_lock
);
1251 * svc_find_xprt - find an RPC transport instance
1252 * @serv: pointer to svc_serv to search
1253 * @xcl_name: C string containing transport's class name
1254 * @net: owner net pointer
1255 * @af: Address family of transport's local address
1256 * @port: transport's IP port number
1258 * Return the transport instance pointer for the endpoint accepting
1259 * connections/peer traffic from the specified transport class,
1260 * address family and port.
1262 * Specifying 0 for the address family or port is effectively a
1263 * wild-card, and will result in matching the first transport in the
1264 * service's list that has a matching class name.
1266 struct svc_xprt
*svc_find_xprt(struct svc_serv
*serv
, const char *xcl_name
,
1267 struct net
*net
, const sa_family_t af
,
1268 const unsigned short port
)
1270 struct svc_xprt
*xprt
;
1271 struct svc_xprt
*found
= NULL
;
1273 /* Sanity check the args */
1274 if (serv
== NULL
|| xcl_name
== NULL
)
1277 spin_lock_bh(&serv
->sv_lock
);
1278 list_for_each_entry(xprt
, &serv
->sv_permsocks
, xpt_list
) {
1279 if (xprt
->xpt_net
!= net
)
1281 if (strcmp(xprt
->xpt_class
->xcl_name
, xcl_name
))
1283 if (af
!= AF_UNSPEC
&& af
!= xprt
->xpt_local
.ss_family
)
1285 if (port
!= 0 && port
!= svc_xprt_local_port(xprt
))
1291 spin_unlock_bh(&serv
->sv_lock
);
1294 EXPORT_SYMBOL_GPL(svc_find_xprt
);
1296 static int svc_one_xprt_name(const struct svc_xprt
*xprt
,
1297 char *pos
, int remaining
)
1301 len
= snprintf(pos
, remaining
, "%s %u\n",
1302 xprt
->xpt_class
->xcl_name
,
1303 svc_xprt_local_port(xprt
));
1304 if (len
>= remaining
)
1305 return -ENAMETOOLONG
;
1310 * svc_xprt_names - format a buffer with a list of transport names
1311 * @serv: pointer to an RPC service
1312 * @buf: pointer to a buffer to be filled in
1313 * @buflen: length of buffer to be filled in
1315 * Fills in @buf with a string containing a list of transport names,
1316 * each name terminated with '\n'.
1318 * Returns positive length of the filled-in string on success; otherwise
1319 * a negative errno value is returned if an error occurs.
1321 int svc_xprt_names(struct svc_serv
*serv
, char *buf
, const int buflen
)
1323 struct svc_xprt
*xprt
;
1327 /* Sanity check args */
1331 spin_lock_bh(&serv
->sv_lock
);
1335 list_for_each_entry(xprt
, &serv
->sv_permsocks
, xpt_list
) {
1336 len
= svc_one_xprt_name(xprt
, pos
, buflen
- totlen
);
1348 spin_unlock_bh(&serv
->sv_lock
);
1351 EXPORT_SYMBOL_GPL(svc_xprt_names
);
1354 /*----------------------------------------------------------------------------*/
1356 static void *svc_pool_stats_start(struct seq_file
*m
, loff_t
*pos
)
1358 unsigned int pidx
= (unsigned int)*pos
;
1359 struct svc_serv
*serv
= m
->private;
1361 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx
);
1364 return SEQ_START_TOKEN
;
1365 return (pidx
> serv
->sv_nrpools
? NULL
: &serv
->sv_pools
[pidx
-1]);
1368 static void *svc_pool_stats_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
1370 struct svc_pool
*pool
= p
;
1371 struct svc_serv
*serv
= m
->private;
1373 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos
);
1375 if (p
== SEQ_START_TOKEN
) {
1376 pool
= &serv
->sv_pools
[0];
1378 unsigned int pidx
= (pool
- &serv
->sv_pools
[0]);
1379 if (pidx
< serv
->sv_nrpools
-1)
1380 pool
= &serv
->sv_pools
[pidx
+1];
1388 static void svc_pool_stats_stop(struct seq_file
*m
, void *p
)
1392 static int svc_pool_stats_show(struct seq_file
*m
, void *p
)
1394 struct svc_pool
*pool
= p
;
1396 if (p
== SEQ_START_TOKEN
) {
1397 seq_puts(m
, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1401 seq_printf(m
, "%u %lu %lu %lu %lu\n",
1403 (unsigned long)atomic_long_read(&pool
->sp_stats
.packets
),
1404 pool
->sp_stats
.sockets_queued
,
1405 (unsigned long)atomic_long_read(&pool
->sp_stats
.threads_woken
),
1406 (unsigned long)atomic_long_read(&pool
->sp_stats
.threads_timedout
));
1411 static const struct seq_operations svc_pool_stats_seq_ops
= {
1412 .start
= svc_pool_stats_start
,
1413 .next
= svc_pool_stats_next
,
1414 .stop
= svc_pool_stats_stop
,
1415 .show
= svc_pool_stats_show
,
1418 int svc_pool_stats_open(struct svc_serv
*serv
, struct file
*file
)
1422 err
= seq_open(file
, &svc_pool_stats_seq_ops
);
1424 ((struct seq_file
*) file
->private_data
)->private = serv
;
1427 EXPORT_SYMBOL(svc_pool_stats_open
);
1429 /*----------------------------------------------------------------------------*/