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 struct svc_deferred_req
*svc_deferred_dequeue(struct svc_xprt
*xprt
);
25 static int svc_deferred_recv(struct svc_rqst
*rqstp
);
26 static struct cache_deferred_req
*svc_defer(struct cache_req
*req
);
27 static void svc_age_temp_xprts(unsigned long closure
);
28 static void svc_delete_xprt(struct svc_xprt
*xprt
);
30 /* apparently the "standard" is that clients close
31 * idle connections after 5 minutes, servers after
33 * http://www.connectathon.org/talks96/nfstcp.pdf
35 static int svc_conn_age_period
= 6*60;
37 /* List of registered transport classes */
38 static DEFINE_SPINLOCK(svc_xprt_class_lock
);
39 static LIST_HEAD(svc_xprt_class_list
);
41 /* SMP locking strategy:
43 * svc_pool->sp_lock protects most of the fields of that pool.
44 * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
45 * when both need to be taken (rare), svc_serv->sv_lock is first.
46 * The "service mutex" protects svc_serv->sv_nrthread.
47 * svc_sock->sk_lock protects the svc_sock->sk_deferred list
48 * and the ->sk_info_authunix cache.
50 * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
51 * enqueued multiply. During normal transport processing this bit
52 * is set by svc_xprt_enqueue and cleared by svc_xprt_received.
53 * Providers should not manipulate this bit directly.
55 * Some flags can be set to certain values at any time
56 * providing that certain rules are followed:
59 * - Can be set or cleared at any time.
60 * - After a set, svc_xprt_enqueue must be called to enqueue
61 * the transport for processing.
62 * - After a clear, the transport must be read/accepted.
63 * If this succeeds, it must be set again.
65 * - Can set at any time. It is never cleared.
67 * - Can only be set while XPT_BUSY is held which ensures
68 * that no other thread will be using the transport or will
69 * try to set XPT_DEAD.
71 int svc_reg_xprt_class(struct svc_xprt_class
*xcl
)
73 struct svc_xprt_class
*cl
;
76 dprintk("svc: Adding svc transport class '%s'\n", xcl
->xcl_name
);
78 INIT_LIST_HEAD(&xcl
->xcl_list
);
79 spin_lock(&svc_xprt_class_lock
);
80 /* Make sure there isn't already a class with the same name */
81 list_for_each_entry(cl
, &svc_xprt_class_list
, xcl_list
) {
82 if (strcmp(xcl
->xcl_name
, cl
->xcl_name
) == 0)
85 list_add_tail(&xcl
->xcl_list
, &svc_xprt_class_list
);
88 spin_unlock(&svc_xprt_class_lock
);
91 EXPORT_SYMBOL_GPL(svc_reg_xprt_class
);
93 void svc_unreg_xprt_class(struct svc_xprt_class
*xcl
)
95 dprintk("svc: Removing svc transport class '%s'\n", xcl
->xcl_name
);
96 spin_lock(&svc_xprt_class_lock
);
97 list_del_init(&xcl
->xcl_list
);
98 spin_unlock(&svc_xprt_class_lock
);
100 EXPORT_SYMBOL_GPL(svc_unreg_xprt_class
);
103 * Format the transport list for printing
105 int svc_print_xprts(char *buf
, int maxlen
)
107 struct svc_xprt_class
*xcl
;
112 spin_lock(&svc_xprt_class_lock
);
113 list_for_each_entry(xcl
, &svc_xprt_class_list
, xcl_list
) {
116 sprintf(tmpstr
, "%s %d\n", xcl
->xcl_name
, xcl
->xcl_max_payload
);
117 slen
= strlen(tmpstr
);
118 if (len
+ slen
> maxlen
)
123 spin_unlock(&svc_xprt_class_lock
);
128 static void svc_xprt_free(struct kref
*kref
)
130 struct svc_xprt
*xprt
=
131 container_of(kref
, struct svc_xprt
, xpt_ref
);
132 struct module
*owner
= xprt
->xpt_class
->xcl_owner
;
133 if (test_bit(XPT_CACHE_AUTH
, &xprt
->xpt_flags
))
134 svcauth_unix_info_release(xprt
);
135 put_net(xprt
->xpt_net
);
136 /* See comment on corresponding get in xs_setup_bc_tcp(): */
137 if (xprt
->xpt_bc_xprt
)
138 xprt_put(xprt
->xpt_bc_xprt
);
139 if (xprt
->xpt_bc_xps
)
140 xprt_switch_put(xprt
->xpt_bc_xps
);
141 xprt
->xpt_ops
->xpo_free(xprt
);
145 void svc_xprt_put(struct svc_xprt
*xprt
)
147 kref_put(&xprt
->xpt_ref
, svc_xprt_free
);
149 EXPORT_SYMBOL_GPL(svc_xprt_put
);
152 * Called by transport drivers to initialize the transport independent
153 * portion of the transport instance.
155 void svc_xprt_init(struct net
*net
, struct svc_xprt_class
*xcl
,
156 struct svc_xprt
*xprt
, struct svc_serv
*serv
)
158 memset(xprt
, 0, sizeof(*xprt
));
159 xprt
->xpt_class
= xcl
;
160 xprt
->xpt_ops
= xcl
->xcl_ops
;
161 kref_init(&xprt
->xpt_ref
);
162 xprt
->xpt_server
= serv
;
163 INIT_LIST_HEAD(&xprt
->xpt_list
);
164 INIT_LIST_HEAD(&xprt
->xpt_ready
);
165 INIT_LIST_HEAD(&xprt
->xpt_deferred
);
166 INIT_LIST_HEAD(&xprt
->xpt_users
);
167 mutex_init(&xprt
->xpt_mutex
);
168 spin_lock_init(&xprt
->xpt_lock
);
169 set_bit(XPT_BUSY
, &xprt
->xpt_flags
);
170 rpc_init_wait_queue(&xprt
->xpt_bc_pending
, "xpt_bc_pending");
171 xprt
->xpt_net
= get_net(net
);
173 EXPORT_SYMBOL_GPL(svc_xprt_init
);
175 static struct svc_xprt
*__svc_xpo_create(struct svc_xprt_class
*xcl
,
176 struct svc_serv
*serv
,
179 const unsigned short port
,
182 struct sockaddr_in sin
= {
183 .sin_family
= AF_INET
,
184 .sin_addr
.s_addr
= htonl(INADDR_ANY
),
185 .sin_port
= htons(port
),
187 #if IS_ENABLED(CONFIG_IPV6)
188 struct sockaddr_in6 sin6
= {
189 .sin6_family
= AF_INET6
,
190 .sin6_addr
= IN6ADDR_ANY_INIT
,
191 .sin6_port
= htons(port
),
194 struct sockaddr
*sap
;
199 sap
= (struct sockaddr
*)&sin
;
202 #if IS_ENABLED(CONFIG_IPV6)
204 sap
= (struct sockaddr
*)&sin6
;
209 return ERR_PTR(-EAFNOSUPPORT
);
212 return xcl
->xcl_ops
->xpo_create(serv
, net
, sap
, len
, flags
);
216 * svc_xprt_received conditionally queues the transport for processing
217 * by another thread. The caller must hold the XPT_BUSY bit and must
218 * not thereafter touch transport data.
220 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
221 * insufficient) data.
223 static void svc_xprt_received(struct svc_xprt
*xprt
)
225 if (!test_bit(XPT_BUSY
, &xprt
->xpt_flags
)) {
226 WARN_ONCE(1, "xprt=0x%p already busy!", xprt
);
230 /* As soon as we clear busy, the xprt could be closed and
231 * 'put', so we need a reference to call svc_enqueue_xprt with:
234 smp_mb__before_atomic();
235 clear_bit(XPT_BUSY
, &xprt
->xpt_flags
);
236 xprt
->xpt_server
->sv_ops
->svo_enqueue_xprt(xprt
);
240 void svc_add_new_perm_xprt(struct svc_serv
*serv
, struct svc_xprt
*new)
242 clear_bit(XPT_TEMP
, &new->xpt_flags
);
243 spin_lock_bh(&serv
->sv_lock
);
244 list_add(&new->xpt_list
, &serv
->sv_permsocks
);
245 spin_unlock_bh(&serv
->sv_lock
);
246 svc_xprt_received(new);
249 int _svc_create_xprt(struct svc_serv
*serv
, const char *xprt_name
,
250 struct net
*net
, const int family
,
251 const unsigned short port
, int flags
)
253 struct svc_xprt_class
*xcl
;
255 spin_lock(&svc_xprt_class_lock
);
256 list_for_each_entry(xcl
, &svc_xprt_class_list
, xcl_list
) {
257 struct svc_xprt
*newxprt
;
258 unsigned short newport
;
260 if (strcmp(xprt_name
, xcl
->xcl_name
))
263 if (!try_module_get(xcl
->xcl_owner
))
266 spin_unlock(&svc_xprt_class_lock
);
267 newxprt
= __svc_xpo_create(xcl
, serv
, net
, family
, port
, flags
);
268 if (IS_ERR(newxprt
)) {
269 module_put(xcl
->xcl_owner
);
270 return PTR_ERR(newxprt
);
272 svc_add_new_perm_xprt(serv
, newxprt
);
273 newport
= svc_xprt_local_port(newxprt
);
277 spin_unlock(&svc_xprt_class_lock
);
278 /* This errno is exposed to user space. Provide a reasonable
279 * perror msg for a bad transport. */
280 return -EPROTONOSUPPORT
;
283 int svc_create_xprt(struct svc_serv
*serv
, const char *xprt_name
,
284 struct net
*net
, const int family
,
285 const unsigned short port
, int flags
)
289 dprintk("svc: creating transport %s[%d]\n", xprt_name
, port
);
290 err
= _svc_create_xprt(serv
, xprt_name
, net
, family
, port
, flags
);
291 if (err
== -EPROTONOSUPPORT
) {
292 request_module("svc%s", xprt_name
);
293 err
= _svc_create_xprt(serv
, xprt_name
, net
, family
, port
, flags
);
296 dprintk("svc: transport %s not found, err %d\n",
300 EXPORT_SYMBOL_GPL(svc_create_xprt
);
303 * Copy the local and remote xprt addresses to the rqstp structure
305 void svc_xprt_copy_addrs(struct svc_rqst
*rqstp
, struct svc_xprt
*xprt
)
307 memcpy(&rqstp
->rq_addr
, &xprt
->xpt_remote
, xprt
->xpt_remotelen
);
308 rqstp
->rq_addrlen
= xprt
->xpt_remotelen
;
311 * Destination address in request is needed for binding the
312 * source address in RPC replies/callbacks later.
314 memcpy(&rqstp
->rq_daddr
, &xprt
->xpt_local
, xprt
->xpt_locallen
);
315 rqstp
->rq_daddrlen
= xprt
->xpt_locallen
;
317 EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs
);
320 * svc_print_addr - Format rq_addr field for printing
321 * @rqstp: svc_rqst struct containing address to print
322 * @buf: target buffer for formatted address
323 * @len: length of target buffer
326 char *svc_print_addr(struct svc_rqst
*rqstp
, char *buf
, size_t len
)
328 return __svc_print_addr(svc_addr(rqstp
), buf
, len
);
330 EXPORT_SYMBOL_GPL(svc_print_addr
);
332 static bool svc_xprt_has_something_to_do(struct svc_xprt
*xprt
)
334 if (xprt
->xpt_flags
& ((1<<XPT_CONN
)|(1<<XPT_CLOSE
)))
336 if (xprt
->xpt_flags
& ((1<<XPT_DATA
)|(1<<XPT_DEFERRED
)))
337 return xprt
->xpt_ops
->xpo_has_wspace(xprt
);
341 void svc_xprt_do_enqueue(struct svc_xprt
*xprt
)
343 struct svc_pool
*pool
;
344 struct svc_rqst
*rqstp
= NULL
;
348 if (!svc_xprt_has_something_to_do(xprt
))
351 /* Mark transport as busy. It will remain in this state until
352 * the provider calls svc_xprt_received. We update XPT_BUSY
353 * atomically because it also guards against trying to enqueue
354 * the transport twice.
356 if (test_and_set_bit(XPT_BUSY
, &xprt
->xpt_flags
)) {
357 /* Don't enqueue transport while already enqueued */
358 dprintk("svc: transport %p busy, not enqueued\n", xprt
);
363 pool
= svc_pool_for_cpu(xprt
->xpt_server
, cpu
);
365 atomic_long_inc(&pool
->sp_stats
.packets
);
368 /* find a thread for this xprt */
370 list_for_each_entry_rcu(rqstp
, &pool
->sp_all_threads
, rq_all
) {
371 /* Do a lockless check first */
372 if (test_bit(RQ_BUSY
, &rqstp
->rq_flags
))
376 * Once the xprt has been queued, it can only be dequeued by
377 * the task that intends to service it. All we can do at that
378 * point is to try to wake this thread back up so that it can
382 spin_lock_bh(&rqstp
->rq_lock
);
383 if (test_and_set_bit(RQ_BUSY
, &rqstp
->rq_flags
)) {
384 /* already busy, move on... */
385 spin_unlock_bh(&rqstp
->rq_lock
);
389 /* this one will do */
390 rqstp
->rq_xprt
= xprt
;
392 spin_unlock_bh(&rqstp
->rq_lock
);
396 atomic_long_inc(&pool
->sp_stats
.threads_woken
);
397 wake_up_process(rqstp
->rq_task
);
404 * We didn't find an idle thread to use, so we need to queue the xprt.
405 * Do so and then search again. If we find one, we can't hook this one
406 * up to it directly but we can wake the thread up in the hopes that it
407 * will pick it up once it searches for a xprt to service.
411 dprintk("svc: transport %p put into queue\n", xprt
);
412 spin_lock_bh(&pool
->sp_lock
);
413 list_add_tail(&xprt
->xpt_ready
, &pool
->sp_sockets
);
414 pool
->sp_stats
.sockets_queued
++;
415 spin_unlock_bh(&pool
->sp_lock
);
421 trace_svc_xprt_do_enqueue(xprt
, rqstp
);
423 EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue
);
426 * Queue up a transport with data pending. If there are idle nfsd
427 * processes, wake 'em up.
430 void svc_xprt_enqueue(struct svc_xprt
*xprt
)
432 if (test_bit(XPT_BUSY
, &xprt
->xpt_flags
))
434 xprt
->xpt_server
->sv_ops
->svo_enqueue_xprt(xprt
);
436 EXPORT_SYMBOL_GPL(svc_xprt_enqueue
);
439 * Dequeue the first transport, if there is one.
441 static struct svc_xprt
*svc_xprt_dequeue(struct svc_pool
*pool
)
443 struct svc_xprt
*xprt
= NULL
;
445 if (list_empty(&pool
->sp_sockets
))
448 spin_lock_bh(&pool
->sp_lock
);
449 if (likely(!list_empty(&pool
->sp_sockets
))) {
450 xprt
= list_first_entry(&pool
->sp_sockets
,
451 struct svc_xprt
, xpt_ready
);
452 list_del_init(&xprt
->xpt_ready
);
455 dprintk("svc: transport %p dequeued, inuse=%d\n",
456 xprt
, atomic_read(&xprt
->xpt_ref
.refcount
));
458 spin_unlock_bh(&pool
->sp_lock
);
460 trace_svc_xprt_dequeue(xprt
);
465 * svc_reserve - change the space reserved for the reply to a request.
466 * @rqstp: The request in question
467 * @space: new max space to reserve
469 * Each request reserves some space on the output queue of the transport
470 * to make sure the reply fits. This function reduces that reserved
471 * space to be the amount of space used already, plus @space.
474 void svc_reserve(struct svc_rqst
*rqstp
, int space
)
476 space
+= rqstp
->rq_res
.head
[0].iov_len
;
478 if (space
< rqstp
->rq_reserved
) {
479 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
480 atomic_sub((rqstp
->rq_reserved
- space
), &xprt
->xpt_reserved
);
481 rqstp
->rq_reserved
= space
;
483 if (xprt
->xpt_ops
->xpo_adjust_wspace
)
484 xprt
->xpt_ops
->xpo_adjust_wspace(xprt
);
485 svc_xprt_enqueue(xprt
);
488 EXPORT_SYMBOL_GPL(svc_reserve
);
490 static void svc_xprt_release(struct svc_rqst
*rqstp
)
492 struct svc_xprt
*xprt
= rqstp
->rq_xprt
;
494 rqstp
->rq_xprt
->xpt_ops
->xpo_release_rqst(rqstp
);
496 kfree(rqstp
->rq_deferred
);
497 rqstp
->rq_deferred
= NULL
;
499 svc_free_res_pages(rqstp
);
500 rqstp
->rq_res
.page_len
= 0;
501 rqstp
->rq_res
.page_base
= 0;
503 /* Reset response buffer and release
505 * But first, check that enough space was reserved
506 * for the reply, otherwise we have a bug!
508 if ((rqstp
->rq_res
.len
) > rqstp
->rq_reserved
)
509 printk(KERN_ERR
"RPC request reserved %d but used %d\n",
513 rqstp
->rq_res
.head
[0].iov_len
= 0;
514 svc_reserve(rqstp
, 0);
515 rqstp
->rq_xprt
= NULL
;
521 * Some svc_serv's will have occasional work to do, even when a xprt is not
522 * waiting to be serviced. This function is there to "kick" a task in one of
523 * those services so that it can wake up and do that work. Note that we only
524 * bother with pool 0 as we don't need to wake up more than one thread for
527 void svc_wake_up(struct svc_serv
*serv
)
529 struct svc_rqst
*rqstp
;
530 struct svc_pool
*pool
;
532 pool
= &serv
->sv_pools
[0];
535 list_for_each_entry_rcu(rqstp
, &pool
->sp_all_threads
, rq_all
) {
536 /* skip any that aren't queued */
537 if (test_bit(RQ_BUSY
, &rqstp
->rq_flags
))
540 dprintk("svc: daemon %p woken up.\n", rqstp
);
541 wake_up_process(rqstp
->rq_task
);
542 trace_svc_wake_up(rqstp
->rq_task
->pid
);
547 /* No free entries available */
548 set_bit(SP_TASK_PENDING
, &pool
->sp_flags
);
550 trace_svc_wake_up(0);
552 EXPORT_SYMBOL_GPL(svc_wake_up
);
554 int svc_port_is_privileged(struct sockaddr
*sin
)
556 switch (sin
->sa_family
) {
558 return ntohs(((struct sockaddr_in
*)sin
)->sin_port
)
561 return ntohs(((struct sockaddr_in6
*)sin
)->sin6_port
)
569 * Make sure that we don't have too many active connections. If we have,
570 * something must be dropped. It's not clear what will happen if we allow
571 * "too many" connections, but when dealing with network-facing software,
572 * we have to code defensively. Here we do that by imposing hard limits.
574 * There's no point in trying to do random drop here for DoS
575 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
576 * attacker can easily beat that.
578 * The only somewhat efficient mechanism would be if drop old
579 * connections from the same IP first. But right now we don't even
580 * record the client IP in svc_sock.
582 * single-threaded services that expect a lot of clients will probably
583 * need to set sv_maxconn to override the default value which is based
584 * on the number of threads
586 static void svc_check_conn_limits(struct svc_serv
*serv
)
588 unsigned int limit
= serv
->sv_maxconn
? serv
->sv_maxconn
:
589 (serv
->sv_nrthreads
+3) * 20;
591 if (serv
->sv_tmpcnt
> limit
) {
592 struct svc_xprt
*xprt
= NULL
;
593 spin_lock_bh(&serv
->sv_lock
);
594 if (!list_empty(&serv
->sv_tempsocks
)) {
595 /* Try to help the admin */
596 net_notice_ratelimited("%s: too many open connections, consider increasing the %s\n",
597 serv
->sv_name
, serv
->sv_maxconn
?
598 "max number of connections" :
599 "number of threads");
601 * Always select the oldest connection. It's not fair,
604 xprt
= list_entry(serv
->sv_tempsocks
.prev
,
607 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
610 spin_unlock_bh(&serv
->sv_lock
);
613 svc_xprt_enqueue(xprt
);
619 static int svc_alloc_arg(struct svc_rqst
*rqstp
)
621 struct svc_serv
*serv
= rqstp
->rq_server
;
626 /* now allocate needed pages. If we get a failure, sleep briefly */
627 pages
= (serv
->sv_max_mesg
+ PAGE_SIZE
) / PAGE_SIZE
;
628 WARN_ON_ONCE(pages
>= RPCSVC_MAXPAGES
);
629 if (pages
>= RPCSVC_MAXPAGES
)
630 /* use as many pages as possible */
631 pages
= RPCSVC_MAXPAGES
- 1;
632 for (i
= 0; i
< pages
; i
++)
633 while (rqstp
->rq_pages
[i
] == NULL
) {
634 struct page
*p
= alloc_page(GFP_KERNEL
);
636 set_current_state(TASK_INTERRUPTIBLE
);
637 if (signalled() || kthread_should_stop()) {
638 set_current_state(TASK_RUNNING
);
641 schedule_timeout(msecs_to_jiffies(500));
643 rqstp
->rq_pages
[i
] = p
;
645 rqstp
->rq_page_end
= &rqstp
->rq_pages
[i
];
646 rqstp
->rq_pages
[i
++] = NULL
; /* this might be seen in nfs_read_actor */
648 /* Make arg->head point to first page and arg->pages point to rest */
649 arg
= &rqstp
->rq_arg
;
650 arg
->head
[0].iov_base
= page_address(rqstp
->rq_pages
[0]);
651 arg
->head
[0].iov_len
= PAGE_SIZE
;
652 arg
->pages
= rqstp
->rq_pages
+ 1;
654 /* save at least one page for response */
655 arg
->page_len
= (pages
-2)*PAGE_SIZE
;
656 arg
->len
= (pages
-1)*PAGE_SIZE
;
657 arg
->tail
[0].iov_len
= 0;
662 rqst_should_sleep(struct svc_rqst
*rqstp
)
664 struct svc_pool
*pool
= rqstp
->rq_pool
;
666 /* did someone call svc_wake_up? */
667 if (test_and_clear_bit(SP_TASK_PENDING
, &pool
->sp_flags
))
670 /* was a socket queued? */
671 if (!list_empty(&pool
->sp_sockets
))
674 /* are we shutting down? */
675 if (signalled() || kthread_should_stop())
678 /* are we freezing? */
679 if (freezing(current
))
685 static struct svc_xprt
*svc_get_next_xprt(struct svc_rqst
*rqstp
, long timeout
)
687 struct svc_xprt
*xprt
;
688 struct svc_pool
*pool
= rqstp
->rq_pool
;
691 /* rq_xprt should be clear on entry */
692 WARN_ON_ONCE(rqstp
->rq_xprt
);
694 /* Normally we will wait up to 5 seconds for any required
695 * cache information to be provided.
697 rqstp
->rq_chandle
.thread_wait
= 5*HZ
;
699 xprt
= svc_xprt_dequeue(pool
);
701 rqstp
->rq_xprt
= xprt
;
703 /* As there is a shortage of threads and this request
704 * had to be queued, don't allow the thread to wait so
705 * long for cache updates.
707 rqstp
->rq_chandle
.thread_wait
= 1*HZ
;
708 clear_bit(SP_TASK_PENDING
, &pool
->sp_flags
);
713 * We have to be able to interrupt this wait
714 * to bring down the daemons ...
716 set_current_state(TASK_INTERRUPTIBLE
);
717 clear_bit(RQ_BUSY
, &rqstp
->rq_flags
);
720 if (likely(rqst_should_sleep(rqstp
)))
721 time_left
= schedule_timeout(timeout
);
723 __set_current_state(TASK_RUNNING
);
727 spin_lock_bh(&rqstp
->rq_lock
);
728 set_bit(RQ_BUSY
, &rqstp
->rq_flags
);
729 spin_unlock_bh(&rqstp
->rq_lock
);
731 xprt
= rqstp
->rq_xprt
;
736 atomic_long_inc(&pool
->sp_stats
.threads_timedout
);
738 if (signalled() || kthread_should_stop())
739 return ERR_PTR(-EINTR
);
740 return ERR_PTR(-EAGAIN
);
743 static void svc_add_new_temp_xprt(struct svc_serv
*serv
, struct svc_xprt
*newxpt
)
745 spin_lock_bh(&serv
->sv_lock
);
746 set_bit(XPT_TEMP
, &newxpt
->xpt_flags
);
747 list_add(&newxpt
->xpt_list
, &serv
->sv_tempsocks
);
749 if (serv
->sv_temptimer
.function
== NULL
) {
750 /* setup timer to age temp transports */
751 setup_timer(&serv
->sv_temptimer
, svc_age_temp_xprts
,
752 (unsigned long)serv
);
753 mod_timer(&serv
->sv_temptimer
,
754 jiffies
+ svc_conn_age_period
* HZ
);
756 spin_unlock_bh(&serv
->sv_lock
);
757 svc_xprt_received(newxpt
);
760 static int svc_handle_xprt(struct svc_rqst
*rqstp
, struct svc_xprt
*xprt
)
762 struct svc_serv
*serv
= rqstp
->rq_server
;
765 if (test_bit(XPT_CLOSE
, &xprt
->xpt_flags
)) {
766 dprintk("svc_recv: found XPT_CLOSE\n");
767 svc_delete_xprt(xprt
);
768 /* Leave XPT_BUSY set on the dead xprt: */
771 if (test_bit(XPT_LISTENER
, &xprt
->xpt_flags
)) {
772 struct svc_xprt
*newxpt
;
774 * We know this module_get will succeed because the
775 * listener holds a reference too
777 __module_get(xprt
->xpt_class
->xcl_owner
);
778 svc_check_conn_limits(xprt
->xpt_server
);
779 newxpt
= xprt
->xpt_ops
->xpo_accept(xprt
);
781 svc_add_new_temp_xprt(serv
, newxpt
);
783 module_put(xprt
->xpt_class
->xcl_owner
);
785 /* XPT_DATA|XPT_DEFERRED case: */
786 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
787 rqstp
, rqstp
->rq_pool
->sp_id
, xprt
,
788 atomic_read(&xprt
->xpt_ref
.refcount
));
789 rqstp
->rq_deferred
= svc_deferred_dequeue(xprt
);
790 if (rqstp
->rq_deferred
)
791 len
= svc_deferred_recv(rqstp
);
793 len
= xprt
->xpt_ops
->xpo_recvfrom(rqstp
);
794 dprintk("svc: got len=%d\n", len
);
795 rqstp
->rq_reserved
= serv
->sv_max_mesg
;
796 atomic_add(rqstp
->rq_reserved
, &xprt
->xpt_reserved
);
798 /* clear XPT_BUSY: */
799 svc_xprt_received(xprt
);
801 trace_svc_handle_xprt(xprt
, len
);
806 * Receive the next request on any transport. This code is carefully
807 * organised not to touch any cachelines in the shared svc_serv
808 * structure, only cachelines in the local svc_pool.
810 int svc_recv(struct svc_rqst
*rqstp
, long timeout
)
812 struct svc_xprt
*xprt
= NULL
;
813 struct svc_serv
*serv
= rqstp
->rq_server
;
816 dprintk("svc: server %p waiting for data (to = %ld)\n",
821 "svc_recv: service %p, transport not NULL!\n",
824 err
= svc_alloc_arg(rqstp
);
831 if (signalled() || kthread_should_stop())
834 xprt
= svc_get_next_xprt(rqstp
, timeout
);
840 len
= svc_handle_xprt(rqstp
, xprt
);
842 /* No data, incomplete (TCP) read, or accept() */
847 clear_bit(XPT_OLD
, &xprt
->xpt_flags
);
849 if (xprt
->xpt_ops
->xpo_secure_port(rqstp
))
850 set_bit(RQ_SECURE
, &rqstp
->rq_flags
);
852 clear_bit(RQ_SECURE
, &rqstp
->rq_flags
);
853 rqstp
->rq_chandle
.defer
= svc_defer
;
854 rqstp
->rq_xid
= svc_getu32(&rqstp
->rq_arg
.head
[0]);
857 serv
->sv_stats
->netcnt
++;
858 trace_svc_recv(rqstp
, len
);
861 rqstp
->rq_res
.len
= 0;
862 svc_xprt_release(rqstp
);
864 trace_svc_recv(rqstp
, err
);
867 EXPORT_SYMBOL_GPL(svc_recv
);
872 void svc_drop(struct svc_rqst
*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(unsigned long closure
)
925 struct svc_serv
*serv
= (struct svc_serv
*)closure
;
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 (atomic_read(&xprt
->xpt_ref
.refcount
) > 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 svc_sock
*svsk
;
971 struct list_head
*le
, *next
;
972 LIST_HEAD(to_be_closed
);
973 struct linger no_linger
= {
978 spin_lock_bh(&serv
->sv_lock
);
979 list_for_each_safe(le
, next
, &serv
->sv_tempsocks
) {
980 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
981 if (rpc_cmp_addr(server_addr
, (struct sockaddr
*)
983 dprintk("svc_age_temp_xprts_now: found %p\n", xprt
);
984 list_move(le
, &to_be_closed
);
987 spin_unlock_bh(&serv
->sv_lock
);
989 while (!list_empty(&to_be_closed
)) {
990 le
= to_be_closed
.next
;
992 xprt
= list_entry(le
, struct svc_xprt
, xpt_list
);
993 dprintk("svc_age_temp_xprts_now: closing %p\n", xprt
);
994 svsk
= container_of(xprt
, struct svc_sock
, sk_xprt
);
995 sock
= svsk
->sk_sock
;
996 kernel_setsockopt(sock
, SOL_SOCKET
, SO_LINGER
,
997 (char *)&no_linger
, sizeof(no_linger
));
998 svc_close_xprt(xprt
);
1001 EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now
);
1003 static void call_xpt_users(struct svc_xprt
*xprt
)
1005 struct svc_xpt_user
*u
;
1007 spin_lock(&xprt
->xpt_lock
);
1008 while (!list_empty(&xprt
->xpt_users
)) {
1009 u
= list_first_entry(&xprt
->xpt_users
, struct svc_xpt_user
, list
);
1013 spin_unlock(&xprt
->xpt_lock
);
1017 * Remove a dead transport
1019 static void svc_delete_xprt(struct svc_xprt
*xprt
)
1021 struct svc_serv
*serv
= xprt
->xpt_server
;
1022 struct svc_deferred_req
*dr
;
1024 /* Only do this once */
1025 if (test_and_set_bit(XPT_DEAD
, &xprt
->xpt_flags
))
1028 dprintk("svc: svc_delete_xprt(%p)\n", xprt
);
1029 xprt
->xpt_ops
->xpo_detach(xprt
);
1031 spin_lock_bh(&serv
->sv_lock
);
1032 list_del_init(&xprt
->xpt_list
);
1033 WARN_ON_ONCE(!list_empty(&xprt
->xpt_ready
));
1034 if (test_bit(XPT_TEMP
, &xprt
->xpt_flags
))
1036 spin_unlock_bh(&serv
->sv_lock
);
1038 while ((dr
= svc_deferred_dequeue(xprt
)) != NULL
)
1041 call_xpt_users(xprt
);
1045 void svc_close_xprt(struct svc_xprt
*xprt
)
1047 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
1048 if (test_and_set_bit(XPT_BUSY
, &xprt
->xpt_flags
))
1049 /* someone else will have to effect the close */
1052 * We expect svc_close_xprt() to work even when no threads are
1053 * running (e.g., while configuring the server before starting
1054 * any threads), so if the transport isn't busy, we delete
1057 svc_delete_xprt(xprt
);
1059 EXPORT_SYMBOL_GPL(svc_close_xprt
);
1061 static int svc_close_list(struct svc_serv
*serv
, struct list_head
*xprt_list
, struct net
*net
)
1063 struct svc_xprt
*xprt
;
1066 spin_lock(&serv
->sv_lock
);
1067 list_for_each_entry(xprt
, xprt_list
, xpt_list
) {
1068 if (xprt
->xpt_net
!= net
)
1071 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
1072 svc_xprt_enqueue(xprt
);
1074 spin_unlock(&serv
->sv_lock
);
1078 static struct svc_xprt
*svc_dequeue_net(struct svc_serv
*serv
, struct net
*net
)
1080 struct svc_pool
*pool
;
1081 struct svc_xprt
*xprt
;
1082 struct svc_xprt
*tmp
;
1085 for (i
= 0; i
< serv
->sv_nrpools
; i
++) {
1086 pool
= &serv
->sv_pools
[i
];
1088 spin_lock_bh(&pool
->sp_lock
);
1089 list_for_each_entry_safe(xprt
, tmp
, &pool
->sp_sockets
, xpt_ready
) {
1090 if (xprt
->xpt_net
!= net
)
1092 list_del_init(&xprt
->xpt_ready
);
1093 spin_unlock_bh(&pool
->sp_lock
);
1096 spin_unlock_bh(&pool
->sp_lock
);
1101 static void svc_clean_up_xprts(struct svc_serv
*serv
, struct net
*net
)
1103 struct svc_xprt
*xprt
;
1105 while ((xprt
= svc_dequeue_net(serv
, net
))) {
1106 set_bit(XPT_CLOSE
, &xprt
->xpt_flags
);
1107 svc_delete_xprt(xprt
);
1112 * Server threads may still be running (especially in the case where the
1113 * service is still running in other network namespaces).
1115 * So we shut down sockets the same way we would on a running server, by
1116 * setting XPT_CLOSE, enqueuing, and letting a thread pick it up to do
1117 * the close. In the case there are no such other threads,
1118 * threads running, svc_clean_up_xprts() does a simple version of a
1119 * server's main event loop, and in the case where there are other
1120 * threads, we may need to wait a little while and then check again to
1121 * see if they're done.
1123 void svc_close_net(struct svc_serv
*serv
, struct net
*net
)
1127 while (svc_close_list(serv
, &serv
->sv_permsocks
, net
) +
1128 svc_close_list(serv
, &serv
->sv_tempsocks
, net
)) {
1130 svc_clean_up_xprts(serv
, net
);
1136 * Handle defer and revisit of requests
1139 static void svc_revisit(struct cache_deferred_req
*dreq
, int too_many
)
1141 struct svc_deferred_req
*dr
=
1142 container_of(dreq
, struct svc_deferred_req
, handle
);
1143 struct svc_xprt
*xprt
= dr
->xprt
;
1145 spin_lock(&xprt
->xpt_lock
);
1146 set_bit(XPT_DEFERRED
, &xprt
->xpt_flags
);
1147 if (too_many
|| test_bit(XPT_DEAD
, &xprt
->xpt_flags
)) {
1148 spin_unlock(&xprt
->xpt_lock
);
1149 dprintk("revisit canceled\n");
1154 dprintk("revisit queued\n");
1156 list_add(&dr
->handle
.recent
, &xprt
->xpt_deferred
);
1157 spin_unlock(&xprt
->xpt_lock
);
1158 svc_xprt_enqueue(xprt
);
1163 * Save the request off for later processing. The request buffer looks
1166 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1168 * This code can only handle requests that consist of an xprt-header
1171 static struct cache_deferred_req
*svc_defer(struct cache_req
*req
)
1173 struct svc_rqst
*rqstp
= container_of(req
, struct svc_rqst
, rq_chandle
);
1174 struct svc_deferred_req
*dr
;
1176 if (rqstp
->rq_arg
.page_len
|| !test_bit(RQ_USEDEFERRAL
, &rqstp
->rq_flags
))
1177 return NULL
; /* if more than a page, give up FIXME */
1178 if (rqstp
->rq_deferred
) {
1179 dr
= rqstp
->rq_deferred
;
1180 rqstp
->rq_deferred
= NULL
;
1184 /* FIXME maybe discard if size too large */
1185 size
= sizeof(struct svc_deferred_req
) + rqstp
->rq_arg
.len
;
1186 dr
= kmalloc(size
, GFP_KERNEL
);
1190 dr
->handle
.owner
= rqstp
->rq_server
;
1191 dr
->prot
= rqstp
->rq_prot
;
1192 memcpy(&dr
->addr
, &rqstp
->rq_addr
, rqstp
->rq_addrlen
);
1193 dr
->addrlen
= rqstp
->rq_addrlen
;
1194 dr
->daddr
= rqstp
->rq_daddr
;
1195 dr
->argslen
= rqstp
->rq_arg
.len
>> 2;
1196 dr
->xprt_hlen
= rqstp
->rq_xprt_hlen
;
1198 /* back up head to the start of the buffer and copy */
1199 skip
= rqstp
->rq_arg
.len
- rqstp
->rq_arg
.head
[0].iov_len
;
1200 memcpy(dr
->args
, rqstp
->rq_arg
.head
[0].iov_base
- skip
,
1203 svc_xprt_get(rqstp
->rq_xprt
);
1204 dr
->xprt
= rqstp
->rq_xprt
;
1205 set_bit(RQ_DROPME
, &rqstp
->rq_flags
);
1207 dr
->handle
.revisit
= svc_revisit
;
1212 * recv data from a deferred request into an active one
1214 static int svc_deferred_recv(struct svc_rqst
*rqstp
)
1216 struct svc_deferred_req
*dr
= rqstp
->rq_deferred
;
1218 /* setup iov_base past transport header */
1219 rqstp
->rq_arg
.head
[0].iov_base
= dr
->args
+ (dr
->xprt_hlen
>>2);
1220 /* The iov_len does not include the transport header bytes */
1221 rqstp
->rq_arg
.head
[0].iov_len
= (dr
->argslen
<<2) - dr
->xprt_hlen
;
1222 rqstp
->rq_arg
.page_len
= 0;
1223 /* The rq_arg.len includes the transport header bytes */
1224 rqstp
->rq_arg
.len
= dr
->argslen
<<2;
1225 rqstp
->rq_prot
= dr
->prot
;
1226 memcpy(&rqstp
->rq_addr
, &dr
->addr
, dr
->addrlen
);
1227 rqstp
->rq_addrlen
= dr
->addrlen
;
1228 /* Save off transport header len in case we get deferred again */
1229 rqstp
->rq_xprt_hlen
= dr
->xprt_hlen
;
1230 rqstp
->rq_daddr
= dr
->daddr
;
1231 rqstp
->rq_respages
= rqstp
->rq_pages
;
1232 return (dr
->argslen
<<2) - dr
->xprt_hlen
;
1236 static struct svc_deferred_req
*svc_deferred_dequeue(struct svc_xprt
*xprt
)
1238 struct svc_deferred_req
*dr
= NULL
;
1240 if (!test_bit(XPT_DEFERRED
, &xprt
->xpt_flags
))
1242 spin_lock(&xprt
->xpt_lock
);
1243 if (!list_empty(&xprt
->xpt_deferred
)) {
1244 dr
= list_entry(xprt
->xpt_deferred
.next
,
1245 struct svc_deferred_req
,
1247 list_del_init(&dr
->handle
.recent
);
1249 clear_bit(XPT_DEFERRED
, &xprt
->xpt_flags
);
1250 spin_unlock(&xprt
->xpt_lock
);
1255 * svc_find_xprt - find an RPC transport instance
1256 * @serv: pointer to svc_serv to search
1257 * @xcl_name: C string containing transport's class name
1258 * @net: owner net pointer
1259 * @af: Address family of transport's local address
1260 * @port: transport's IP port number
1262 * Return the transport instance pointer for the endpoint accepting
1263 * connections/peer traffic from the specified transport class,
1264 * address family and port.
1266 * Specifying 0 for the address family or port is effectively a
1267 * wild-card, and will result in matching the first transport in the
1268 * service's list that has a matching class name.
1270 struct svc_xprt
*svc_find_xprt(struct svc_serv
*serv
, const char *xcl_name
,
1271 struct net
*net
, const sa_family_t af
,
1272 const unsigned short port
)
1274 struct svc_xprt
*xprt
;
1275 struct svc_xprt
*found
= NULL
;
1277 /* Sanity check the args */
1278 if (serv
== NULL
|| xcl_name
== NULL
)
1281 spin_lock_bh(&serv
->sv_lock
);
1282 list_for_each_entry(xprt
, &serv
->sv_permsocks
, xpt_list
) {
1283 if (xprt
->xpt_net
!= net
)
1285 if (strcmp(xprt
->xpt_class
->xcl_name
, xcl_name
))
1287 if (af
!= AF_UNSPEC
&& af
!= xprt
->xpt_local
.ss_family
)
1289 if (port
!= 0 && port
!= svc_xprt_local_port(xprt
))
1295 spin_unlock_bh(&serv
->sv_lock
);
1298 EXPORT_SYMBOL_GPL(svc_find_xprt
);
1300 static int svc_one_xprt_name(const struct svc_xprt
*xprt
,
1301 char *pos
, int remaining
)
1305 len
= snprintf(pos
, remaining
, "%s %u\n",
1306 xprt
->xpt_class
->xcl_name
,
1307 svc_xprt_local_port(xprt
));
1308 if (len
>= remaining
)
1309 return -ENAMETOOLONG
;
1314 * svc_xprt_names - format a buffer with a list of transport names
1315 * @serv: pointer to an RPC service
1316 * @buf: pointer to a buffer to be filled in
1317 * @buflen: length of buffer to be filled in
1319 * Fills in @buf with a string containing a list of transport names,
1320 * each name terminated with '\n'.
1322 * Returns positive length of the filled-in string on success; otherwise
1323 * a negative errno value is returned if an error occurs.
1325 int svc_xprt_names(struct svc_serv
*serv
, char *buf
, const int buflen
)
1327 struct svc_xprt
*xprt
;
1331 /* Sanity check args */
1335 spin_lock_bh(&serv
->sv_lock
);
1339 list_for_each_entry(xprt
, &serv
->sv_permsocks
, xpt_list
) {
1340 len
= svc_one_xprt_name(xprt
, pos
, buflen
- totlen
);
1352 spin_unlock_bh(&serv
->sv_lock
);
1355 EXPORT_SYMBOL_GPL(svc_xprt_names
);
1358 /*----------------------------------------------------------------------------*/
1360 static void *svc_pool_stats_start(struct seq_file
*m
, loff_t
*pos
)
1362 unsigned int pidx
= (unsigned int)*pos
;
1363 struct svc_serv
*serv
= m
->private;
1365 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx
);
1368 return SEQ_START_TOKEN
;
1369 return (pidx
> serv
->sv_nrpools
? NULL
: &serv
->sv_pools
[pidx
-1]);
1372 static void *svc_pool_stats_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
1374 struct svc_pool
*pool
= p
;
1375 struct svc_serv
*serv
= m
->private;
1377 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos
);
1379 if (p
== SEQ_START_TOKEN
) {
1380 pool
= &serv
->sv_pools
[0];
1382 unsigned int pidx
= (pool
- &serv
->sv_pools
[0]);
1383 if (pidx
< serv
->sv_nrpools
-1)
1384 pool
= &serv
->sv_pools
[pidx
+1];
1392 static void svc_pool_stats_stop(struct seq_file
*m
, void *p
)
1396 static int svc_pool_stats_show(struct seq_file
*m
, void *p
)
1398 struct svc_pool
*pool
= p
;
1400 if (p
== SEQ_START_TOKEN
) {
1401 seq_puts(m
, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
1405 seq_printf(m
, "%u %lu %lu %lu %lu\n",
1407 (unsigned long)atomic_long_read(&pool
->sp_stats
.packets
),
1408 pool
->sp_stats
.sockets_queued
,
1409 (unsigned long)atomic_long_read(&pool
->sp_stats
.threads_woken
),
1410 (unsigned long)atomic_long_read(&pool
->sp_stats
.threads_timedout
));
1415 static const struct seq_operations svc_pool_stats_seq_ops
= {
1416 .start
= svc_pool_stats_start
,
1417 .next
= svc_pool_stats_next
,
1418 .stop
= svc_pool_stats_stop
,
1419 .show
= svc_pool_stats_show
,
1422 int svc_pool_stats_open(struct svc_serv
*serv
, struct file
*file
)
1426 err
= seq_open(file
, &svc_pool_stats_seq_ops
);
1428 ((struct seq_file
*) file
->private_data
)->private = serv
;
1431 EXPORT_SYMBOL(svc_pool_stats_open
);
1433 /*----------------------------------------------------------------------------*/