blob: 0d80c064e6341bb8980782a8d8abc90a01e37669 [file] [log] [blame]
Tom Tucker1d8206b92007-12-30 21:07:15 -06001/*
2 * linux/net/sunrpc/svc_xprt.c
3 *
4 * Author: Tom Tucker <tom@opengridcomputing.com>
5 */
6
7#include <linux/sched.h>
8#include <linux/errno.h>
Tom Tucker1d8206b92007-12-30 21:07:15 -06009#include <linux/freezer.h>
Jeff Layton70867212008-02-07 16:34:54 -050010#include <linux/kthread.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090011#include <linux/slab.h>
Tom Tucker1d8206b92007-12-30 21:07:15 -060012#include <net/sock.h>
Tom Tucker1d8206b92007-12-30 21:07:15 -060013#include <linux/sunrpc/stats.h>
14#include <linux/sunrpc/svc_xprt.h>
H Hartley Sweetendcf1a352009-04-22 20:18:19 -040015#include <linux/sunrpc/svcsock.h>
J. Bruce Fields99de8ea2010-12-08 12:45:44 -050016#include <linux/sunrpc/xprt.h>
Paul Gortmaker3a9a2312011-05-27 09:12:25 -040017#include <linux/module.h>
Tom Tucker1d8206b92007-12-30 21:07:15 -060018
19#define RPCDBG_FACILITY RPCDBG_SVCXPRT
20
Tom Tucker0f0257e2007-12-30 21:08:27 -060021static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
22static int svc_deferred_recv(struct svc_rqst *rqstp);
23static struct cache_deferred_req *svc_defer(struct cache_req *req);
24static void svc_age_temp_xprts(unsigned long closure);
J. Bruce Fields7710ec32011-11-25 18:44:05 -050025static void svc_delete_xprt(struct svc_xprt *xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -060026
27/* apparently the "standard" is that clients close
28 * idle connections after 5 minutes, servers after
29 * 6 minutes
30 * http://www.connectathon.org/talks96/nfstcp.pdf
31 */
32static int svc_conn_age_period = 6*60;
33
Tom Tucker1d8206b92007-12-30 21:07:15 -060034/* List of registered transport classes */
35static DEFINE_SPINLOCK(svc_xprt_class_lock);
36static LIST_HEAD(svc_xprt_class_list);
37
Tom Tucker0f0257e2007-12-30 21:08:27 -060038/* SMP locking strategy:
39 *
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.
46 *
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.
51 *
52 * Some flags can be set to certain values at any time
53 * providing that certain rules are followed:
54 *
55 * XPT_CONN, XPT_DATA:
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.
61 * XPT_CLOSE:
62 * - Can set at any time. It is never cleared.
63 * XPT_DEAD:
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.
67 */
68
Tom Tucker1d8206b92007-12-30 21:07:15 -060069int svc_reg_xprt_class(struct svc_xprt_class *xcl)
70{
71 struct svc_xprt_class *cl;
72 int res = -EEXIST;
73
74 dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
75
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)
81 goto out;
82 }
83 list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
84 res = 0;
85out:
86 spin_unlock(&svc_xprt_class_lock);
87 return res;
88}
89EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
90
91void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
92{
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);
97}
98EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
99
Tom Tuckerdc9a16e2007-12-30 21:08:31 -0600100/*
101 * Format the transport list for printing
102 */
103int svc_print_xprts(char *buf, int maxlen)
104{
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400105 struct svc_xprt_class *xcl;
Tom Tuckerdc9a16e2007-12-30 21:08:31 -0600106 char tmpstr[80];
107 int len = 0;
108 buf[0] = '\0';
109
110 spin_lock(&svc_xprt_class_lock);
Pavel Emelyanov8f3a6de2010-10-05 23:30:19 +0400111 list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
Tom Tuckerdc9a16e2007-12-30 21:08:31 -0600112 int slen;
Tom Tuckerdc9a16e2007-12-30 21:08:31 -0600113
114 sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
115 slen = strlen(tmpstr);
116 if (len + slen > maxlen)
117 break;
118 len += slen;
119 strcat(buf, tmpstr);
120 }
121 spin_unlock(&svc_xprt_class_lock);
122
123 return len;
124}
125
Tom Tuckere1b31572007-12-30 21:07:46 -0600126static void svc_xprt_free(struct kref *kref)
127{
128 struct svc_xprt *xprt =
129 container_of(kref, struct svc_xprt, xpt_ref);
130 struct module *owner = xprt->xpt_class->xcl_owner;
Pavel Emelyanove3bfca02010-09-27 13:58:42 +0400131 if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags))
132 svcauth_unix_info_release(xprt);
Pavel Emelyanov4fb85182010-09-27 14:00:49 +0400133 put_net(xprt->xpt_net);
J. Bruce Fields99de8ea2010-12-08 12:45:44 -0500134 /* See comment on corresponding get in xs_setup_bc_tcp(): */
135 if (xprt->xpt_bc_xprt)
136 xprt_put(xprt->xpt_bc_xprt);
Tom Tuckere1b31572007-12-30 21:07:46 -0600137 xprt->xpt_ops->xpo_free(xprt);
138 module_put(owner);
139}
140
141void svc_xprt_put(struct svc_xprt *xprt)
142{
143 kref_put(&xprt->xpt_ref, svc_xprt_free);
144}
145EXPORT_SYMBOL_GPL(svc_xprt_put);
146
Tom Tucker1d8206b92007-12-30 21:07:15 -0600147/*
148 * Called by transport drivers to initialize the transport independent
149 * portion of the transport instance.
150 */
Tom Tuckerbb5cf162007-12-30 21:07:50 -0600151void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
152 struct svc_serv *serv)
Tom Tucker1d8206b92007-12-30 21:07:15 -0600153{
154 memset(xprt, 0, sizeof(*xprt));
155 xprt->xpt_class = xcl;
156 xprt->xpt_ops = xcl->xcl_ops;
Tom Tuckere1b31572007-12-30 21:07:46 -0600157 kref_init(&xprt->xpt_ref);
Tom Tuckerbb5cf162007-12-30 21:07:50 -0600158 xprt->xpt_server = serv;
Tom Tucker7a182082007-12-30 21:07:53 -0600159 INIT_LIST_HEAD(&xprt->xpt_list);
160 INIT_LIST_HEAD(&xprt->xpt_ready);
Tom Tucker8c7b0172007-12-30 21:08:10 -0600161 INIT_LIST_HEAD(&xprt->xpt_deferred);
J. Bruce Fieldsedc7a892010-03-22 15:37:17 -0400162 INIT_LIST_HEAD(&xprt->xpt_users);
Tom Tuckera50fea22007-12-30 21:07:59 -0600163 mutex_init(&xprt->xpt_mutex);
Tom Tuckerdef13d72007-12-30 21:08:08 -0600164 spin_lock_init(&xprt->xpt_lock);
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600165 set_bit(XPT_BUSY, &xprt->xpt_flags);
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300166 rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
Pavel Emelyanov4fb85182010-09-27 14:00:49 +0400167 xprt->xpt_net = get_net(&init_net);
Tom Tucker1d8206b92007-12-30 21:07:15 -0600168}
169EXPORT_SYMBOL_GPL(svc_xprt_init);
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600170
Chuck Lever5dd248f2008-06-30 18:45:37 -0400171static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
172 struct svc_serv *serv,
Pavel Emelyanov62832c02010-09-29 16:04:18 +0400173 struct net *net,
Chuck Lever9652ada2009-03-18 20:46:21 -0400174 const int family,
175 const unsigned short port,
176 int flags)
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600177{
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600178 struct sockaddr_in sin = {
179 .sin_family = AF_INET,
Al Viroe6f1ceb2008-03-17 22:44:53 -0700180 .sin_addr.s_addr = htonl(INADDR_ANY),
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600181 .sin_port = htons(port),
182 };
Chuck Leverd6783b22010-01-26 14:04:04 -0500183#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Chuck Lever5dd248f2008-06-30 18:45:37 -0400184 struct sockaddr_in6 sin6 = {
185 .sin6_family = AF_INET6,
186 .sin6_addr = IN6ADDR_ANY_INIT,
187 .sin6_port = htons(port),
188 };
Chuck Leverd6783b22010-01-26 14:04:04 -0500189#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
Chuck Lever5dd248f2008-06-30 18:45:37 -0400190 struct sockaddr *sap;
191 size_t len;
192
Chuck Lever9652ada2009-03-18 20:46:21 -0400193 switch (family) {
194 case PF_INET:
Chuck Lever5dd248f2008-06-30 18:45:37 -0400195 sap = (struct sockaddr *)&sin;
196 len = sizeof(sin);
197 break;
Chuck Leverd6783b22010-01-26 14:04:04 -0500198#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Chuck Lever9652ada2009-03-18 20:46:21 -0400199 case PF_INET6:
Chuck Lever5dd248f2008-06-30 18:45:37 -0400200 sap = (struct sockaddr *)&sin6;
201 len = sizeof(sin6);
202 break;
Chuck Leverd6783b22010-01-26 14:04:04 -0500203#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
Chuck Lever5dd248f2008-06-30 18:45:37 -0400204 default:
205 return ERR_PTR(-EAFNOSUPPORT);
206 }
207
Pavel Emelyanov62832c02010-09-29 16:04:18 +0400208 return xcl->xcl_ops->xpo_create(serv, net, sap, len, flags);
Chuck Lever5dd248f2008-06-30 18:45:37 -0400209}
210
Chuck Lever9652ada2009-03-18 20:46:21 -0400211int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
Pavel Emelyanovfc5d00b2010-09-29 16:03:50 +0400212 struct net *net, const int family,
213 const unsigned short port, int flags)
Chuck Lever5dd248f2008-06-30 18:45:37 -0400214{
215 struct svc_xprt_class *xcl;
216
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600217 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) {
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600220 struct svc_xprt *newxprt;
NeilBrowned2849d2010-11-16 16:55:19 +1100221 unsigned short newport;
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600222
223 if (strcmp(xprt_name, xcl->xcl_name))
224 continue;
225
226 if (!try_module_get(xcl->xcl_owner))
227 goto err;
228
229 spin_unlock(&svc_xprt_class_lock);
Pavel Emelyanov62832c02010-09-29 16:04:18 +0400230 newxprt = __svc_xpo_create(xcl, serv, net, family, port, flags);
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600231 if (IS_ERR(newxprt)) {
232 module_put(xcl->xcl_owner);
233 return PTR_ERR(newxprt);
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600234 }
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600235
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);
NeilBrowned2849d2010-11-16 16:55:19 +1100240 newport = svc_xprt_local_port(newxprt);
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600241 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
NeilBrowned2849d2010-11-16 16:55:19 +1100242 return newport;
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600243 }
Tom Tucker4e5caaa2007-12-30 21:08:20 -0600244 err:
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600245 spin_unlock(&svc_xprt_class_lock);
246 dprintk("svc: transport %s not found\n", xprt_name);
Chuck Lever68717902010-01-26 14:04:13 -0500247
248 /* This errno is exposed to user space. Provide a reasonable
249 * perror msg for a bad transport. */
250 return -EPROTONOSUPPORT;
Tom Tuckerb700cbb2007-12-30 21:07:42 -0600251}
252EXPORT_SYMBOL_GPL(svc_create_xprt);
Tom Tucker9dbc2402007-12-30 21:08:12 -0600253
254/*
255 * Copy the local and remote xprt addresses to the rqstp structure
256 */
257void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
258{
Tom Tucker9dbc2402007-12-30 21:08:12 -0600259 memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
260 rqstp->rq_addrlen = xprt->xpt_remotelen;
261
262 /*
263 * Destination address in request is needed for binding the
264 * source address in RPC replies/callbacks later.
265 */
Mi Jinlong849a1cf2011-08-30 17:18:41 +0800266 memcpy(&rqstp->rq_daddr, &xprt->xpt_local, xprt->xpt_locallen);
267 rqstp->rq_daddrlen = xprt->xpt_locallen;
Tom Tucker9dbc2402007-12-30 21:08:12 -0600268}
269EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
270
Tom Tucker0f0257e2007-12-30 21:08:27 -0600271/**
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
276 *
277 */
278char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
279{
280 return __svc_print_addr(svc_addr(rqstp), buf, len);
281}
282EXPORT_SYMBOL_GPL(svc_print_addr);
283
284/*
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
288 * the cache.
289 */
290static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
291{
292 list_add(&rqstp->rq_list, &pool->sp_threads);
293}
294
295/*
296 * Dequeue an nfsd thread. Must have pool->sp_lock held.
297 */
298static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
299{
300 list_del(&rqstp->rq_list);
301}
302
J. Bruce Fields9c335c02010-10-26 11:32:03 -0400303static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt)
304{
305 if (xprt->xpt_flags & ((1<<XPT_CONN)|(1<<XPT_CLOSE)))
306 return true;
307 if (xprt->xpt_flags & ((1<<XPT_DATA)|(1<<XPT_DEFERRED)))
308 return xprt->xpt_ops->xpo_has_wspace(xprt);
309 return false;
310}
311
Tom Tucker0f0257e2007-12-30 21:08:27 -0600312/*
313 * Queue up a transport with data pending. If there are idle nfsd
314 * processes, wake 'em up.
315 *
316 */
317void svc_xprt_enqueue(struct svc_xprt *xprt)
318{
319 struct svc_serv *serv = xprt->xpt_server;
320 struct svc_pool *pool;
321 struct svc_rqst *rqstp;
322 int cpu;
323
J. Bruce Fields9c335c02010-10-26 11:32:03 -0400324 if (!svc_xprt_has_something_to_do(xprt))
Tom Tucker0f0257e2007-12-30 21:08:27 -0600325 return;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600326
327 cpu = get_cpu();
328 pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
329 put_cpu();
330
331 spin_lock_bh(&pool->sp_lock);
332
J. Bruce Fields78c210e2009-08-06 15:41:34 -0400333 if (!list_empty(&pool->sp_threads) &&
334 !list_empty(&pool->sp_sockets))
335 printk(KERN_ERR
336 "svc_xprt_enqueue: "
337 "threads and transports both waiting??\n");
338
Greg Banks03cf6c92009-01-13 21:26:36 +1100339 pool->sp_stats.packets++;
340
Tom Tucker0f0257e2007-12-30 21:08:27 -0600341 /* Mark transport as busy. It will remain in this state until
342 * the provider calls svc_xprt_received. We update XPT_BUSY
343 * atomically because it also guards against trying to enqueue
344 * the transport twice.
345 */
346 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
347 /* Don't enqueue transport while already enqueued */
348 dprintk("svc: transport %p busy, not enqueued\n", xprt);
349 goto out_unlock;
350 }
Tom Tucker0f0257e2007-12-30 21:08:27 -0600351
J. Bruce Fields78c210e2009-08-06 15:41:34 -0400352 if (!list_empty(&pool->sp_threads)) {
Tom Tucker0f0257e2007-12-30 21:08:27 -0600353 rqstp = list_entry(pool->sp_threads.next,
354 struct svc_rqst,
355 rq_list);
356 dprintk("svc: transport %p served by daemon %p\n",
357 xprt, rqstp);
358 svc_thread_dequeue(pool, rqstp);
359 if (rqstp->rq_xprt)
360 printk(KERN_ERR
361 "svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
362 rqstp, rqstp->rq_xprt);
363 rqstp->rq_xprt = xprt;
364 svc_xprt_get(xprt);
365 rqstp->rq_reserved = serv->sv_max_mesg;
366 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
Greg Banks03cf6c92009-01-13 21:26:36 +1100367 pool->sp_stats.threads_woken++;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600368 wake_up(&rqstp->rq_wait);
369 } else {
370 dprintk("svc: transport %p put into queue\n", xprt);
371 list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
Greg Banks03cf6c92009-01-13 21:26:36 +1100372 pool->sp_stats.sockets_queued++;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600373 }
374
375out_unlock:
376 spin_unlock_bh(&pool->sp_lock);
377}
378EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
379
380/*
381 * Dequeue the first transport. Must be called with the pool->sp_lock held.
382 */
383static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
384{
385 struct svc_xprt *xprt;
386
387 if (list_empty(&pool->sp_sockets))
388 return NULL;
389
390 xprt = list_entry(pool->sp_sockets.next,
391 struct svc_xprt, xpt_ready);
392 list_del_init(&xprt->xpt_ready);
393
394 dprintk("svc: transport %p dequeued, inuse=%d\n",
395 xprt, atomic_read(&xprt->xpt_ref.refcount));
396
397 return xprt;
398}
399
400/*
401 * svc_xprt_received conditionally queues the transport for processing
402 * by another thread. The caller must hold the XPT_BUSY bit and must
403 * not thereafter touch transport data.
404 *
405 * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
406 * insufficient) data.
407 */
408void svc_xprt_received(struct svc_xprt *xprt)
409{
410 BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
NeilBrowned2849d2010-11-16 16:55:19 +1100411 /* As soon as we clear busy, the xprt could be closed and
412 * 'put', so we need a reference to call svc_xprt_enqueue with:
413 */
414 svc_xprt_get(xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600415 clear_bit(XPT_BUSY, &xprt->xpt_flags);
416 svc_xprt_enqueue(xprt);
NeilBrowned2849d2010-11-16 16:55:19 +1100417 svc_xprt_put(xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600418}
419EXPORT_SYMBOL_GPL(svc_xprt_received);
420
421/**
422 * svc_reserve - change the space reserved for the reply to a request.
423 * @rqstp: The request in question
424 * @space: new max space to reserve
425 *
426 * Each request reserves some space on the output queue of the transport
427 * to make sure the reply fits. This function reduces that reserved
428 * space to be the amount of space used already, plus @space.
429 *
430 */
431void svc_reserve(struct svc_rqst *rqstp, int space)
432{
433 space += rqstp->rq_res.head[0].iov_len;
434
435 if (space < rqstp->rq_reserved) {
436 struct svc_xprt *xprt = rqstp->rq_xprt;
437 atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
438 rqstp->rq_reserved = space;
439
440 svc_xprt_enqueue(xprt);
441 }
442}
Trond Myklebust24c37672008-12-23 16:30:12 -0500443EXPORT_SYMBOL_GPL(svc_reserve);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600444
445static void svc_xprt_release(struct svc_rqst *rqstp)
446{
447 struct svc_xprt *xprt = rqstp->rq_xprt;
448
449 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
450
Tom Tucker2779e3a2009-01-05 11:12:52 -0600451 kfree(rqstp->rq_deferred);
452 rqstp->rq_deferred = NULL;
453
Tom Tucker0f0257e2007-12-30 21:08:27 -0600454 svc_free_res_pages(rqstp);
455 rqstp->rq_res.page_len = 0;
456 rqstp->rq_res.page_base = 0;
457
458 /* Reset response buffer and release
459 * the reservation.
460 * But first, check that enough space was reserved
461 * for the reply, otherwise we have a bug!
462 */
463 if ((rqstp->rq_res.len) > rqstp->rq_reserved)
464 printk(KERN_ERR "RPC request reserved %d but used %d\n",
465 rqstp->rq_reserved,
466 rqstp->rq_res.len);
467
468 rqstp->rq_res.head[0].iov_len = 0;
469 svc_reserve(rqstp, 0);
470 rqstp->rq_xprt = NULL;
471
472 svc_xprt_put(xprt);
473}
474
475/*
476 * External function to wake up a server waiting for data
477 * This really only makes sense for services like lockd
478 * which have exactly one thread anyway.
479 */
480void svc_wake_up(struct svc_serv *serv)
481{
482 struct svc_rqst *rqstp;
483 unsigned int i;
484 struct svc_pool *pool;
485
486 for (i = 0; i < serv->sv_nrpools; i++) {
487 pool = &serv->sv_pools[i];
488
489 spin_lock_bh(&pool->sp_lock);
490 if (!list_empty(&pool->sp_threads)) {
491 rqstp = list_entry(pool->sp_threads.next,
492 struct svc_rqst,
493 rq_list);
494 dprintk("svc: daemon %p woken up.\n", rqstp);
495 /*
496 svc_thread_dequeue(pool, rqstp);
497 rqstp->rq_xprt = NULL;
498 */
499 wake_up(&rqstp->rq_wait);
500 }
501 spin_unlock_bh(&pool->sp_lock);
502 }
503}
Trond Myklebust24c37672008-12-23 16:30:12 -0500504EXPORT_SYMBOL_GPL(svc_wake_up);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600505
506int svc_port_is_privileged(struct sockaddr *sin)
507{
508 switch (sin->sa_family) {
509 case AF_INET:
510 return ntohs(((struct sockaddr_in *)sin)->sin_port)
511 < PROT_SOCK;
512 case AF_INET6:
513 return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
514 < PROT_SOCK;
515 default:
516 return 0;
517 }
518}
519
520/*
Jeff Laytonc9233eb2008-10-20 11:51:57 -0400521 * Make sure that we don't have too many active connections. If we have,
522 * something must be dropped. It's not clear what will happen if we allow
523 * "too many" connections, but when dealing with network-facing software,
524 * we have to code defensively. Here we do that by imposing hard limits.
Tom Tucker0f0257e2007-12-30 21:08:27 -0600525 *
526 * There's no point in trying to do random drop here for DoS
527 * prevention. The NFS clients does 1 reconnect in 15 seconds. An
528 * attacker can easily beat that.
529 *
530 * The only somewhat efficient mechanism would be if drop old
531 * connections from the same IP first. But right now we don't even
532 * record the client IP in svc_sock.
Jeff Laytonc9233eb2008-10-20 11:51:57 -0400533 *
534 * single-threaded services that expect a lot of clients will probably
535 * need to set sv_maxconn to override the default value which is based
536 * on the number of threads
Tom Tucker0f0257e2007-12-30 21:08:27 -0600537 */
538static void svc_check_conn_limits(struct svc_serv *serv)
539{
Jeff Laytonc9233eb2008-10-20 11:51:57 -0400540 unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
541 (serv->sv_nrthreads+3) * 20;
542
543 if (serv->sv_tmpcnt > limit) {
Tom Tucker0f0257e2007-12-30 21:08:27 -0600544 struct svc_xprt *xprt = NULL;
545 spin_lock_bh(&serv->sv_lock);
546 if (!list_empty(&serv->sv_tempsocks)) {
547 if (net_ratelimit()) {
548 /* Try to help the admin */
549 printk(KERN_NOTICE "%s: too many open "
Jeff Laytonc9233eb2008-10-20 11:51:57 -0400550 "connections, consider increasing %s\n",
551 serv->sv_name, serv->sv_maxconn ?
552 "the max number of connections." :
553 "the number of threads.");
Tom Tucker0f0257e2007-12-30 21:08:27 -0600554 }
555 /*
556 * Always select the oldest connection. It's not fair,
557 * but so is life
558 */
559 xprt = list_entry(serv->sv_tempsocks.prev,
560 struct svc_xprt,
561 xpt_list);
562 set_bit(XPT_CLOSE, &xprt->xpt_flags);
563 svc_xprt_get(xprt);
564 }
565 spin_unlock_bh(&serv->sv_lock);
566
567 if (xprt) {
568 svc_xprt_enqueue(xprt);
569 svc_xprt_put(xprt);
570 }
571 }
572}
573
574/*
575 * Receive the next request on any transport. This code is carefully
576 * organised not to touch any cachelines in the shared svc_serv
577 * structure, only cachelines in the local svc_pool.
578 */
579int svc_recv(struct svc_rqst *rqstp, long timeout)
580{
581 struct svc_xprt *xprt = NULL;
582 struct svc_serv *serv = rqstp->rq_server;
583 struct svc_pool *pool = rqstp->rq_pool;
584 int len, i;
585 int pages;
586 struct xdr_buf *arg;
587 DECLARE_WAITQUEUE(wait, current);
Greg Banks03cf6c92009-01-13 21:26:36 +1100588 long time_left;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600589
590 dprintk("svc: server %p waiting for data (to = %ld)\n",
591 rqstp, timeout);
592
593 if (rqstp->rq_xprt)
594 printk(KERN_ERR
595 "svc_recv: service %p, transport not NULL!\n",
596 rqstp);
597 if (waitqueue_active(&rqstp->rq_wait))
598 printk(KERN_ERR
599 "svc_recv: service %p, wait queue active!\n",
600 rqstp);
601
602 /* now allocate needed pages. If we get a failure, sleep briefly */
603 pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
604 for (i = 0; i < pages ; i++)
605 while (rqstp->rq_pages[i] == NULL) {
606 struct page *p = alloc_page(GFP_KERNEL);
607 if (!p) {
Jeff Layton7b54fe62008-02-12 11:47:24 -0500608 set_current_state(TASK_INTERRUPTIBLE);
609 if (signalled() || kthread_should_stop()) {
610 set_current_state(TASK_RUNNING);
Jeff Layton70867212008-02-07 16:34:54 -0500611 return -EINTR;
Jeff Layton7b54fe62008-02-12 11:47:24 -0500612 }
613 schedule_timeout(msecs_to_jiffies(500));
Tom Tucker0f0257e2007-12-30 21:08:27 -0600614 }
615 rqstp->rq_pages[i] = p;
616 }
617 rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
618 BUG_ON(pages >= RPCSVC_MAXPAGES);
619
620 /* Make arg->head point to first page and arg->pages point to rest */
621 arg = &rqstp->rq_arg;
622 arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
623 arg->head[0].iov_len = PAGE_SIZE;
624 arg->pages = rqstp->rq_pages + 1;
625 arg->page_base = 0;
626 /* save at least one page for response */
627 arg->page_len = (pages-2)*PAGE_SIZE;
628 arg->len = (pages-1)*PAGE_SIZE;
629 arg->tail[0].iov_len = 0;
630
631 try_to_freeze();
632 cond_resched();
Jeff Layton70867212008-02-07 16:34:54 -0500633 if (signalled() || kthread_should_stop())
Tom Tucker0f0257e2007-12-30 21:08:27 -0600634 return -EINTR;
635
NeilBrownf16b6e82010-08-12 17:04:06 +1000636 /* Normally we will wait up to 5 seconds for any required
637 * cache information to be provided.
638 */
639 rqstp->rq_chandle.thread_wait = 5*HZ;
640
Tom Tucker0f0257e2007-12-30 21:08:27 -0600641 spin_lock_bh(&pool->sp_lock);
642 xprt = svc_xprt_dequeue(pool);
643 if (xprt) {
644 rqstp->rq_xprt = xprt;
645 svc_xprt_get(xprt);
646 rqstp->rq_reserved = serv->sv_max_mesg;
647 atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
NeilBrownf16b6e82010-08-12 17:04:06 +1000648
649 /* As there is a shortage of threads and this request
J. Bruce Fields6610f722010-08-26 13:19:52 -0400650 * had to be queued, don't allow the thread to wait so
NeilBrownf16b6e82010-08-12 17:04:06 +1000651 * long for cache updates.
652 */
653 rqstp->rq_chandle.thread_wait = 1*HZ;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600654 } else {
655 /* No data pending. Go to sleep */
656 svc_thread_enqueue(pool, rqstp);
657
658 /*
659 * We have to be able to interrupt this wait
660 * to bring down the daemons ...
661 */
662 set_current_state(TASK_INTERRUPTIBLE);
Jeff Layton70867212008-02-07 16:34:54 -0500663
664 /*
665 * checking kthread_should_stop() here allows us to avoid
666 * locking and signalling when stopping kthreads that call
667 * svc_recv. If the thread has already been woken up, then
668 * we can exit here without sleeping. If not, then it
669 * it'll be woken up quickly during the schedule_timeout
670 */
671 if (kthread_should_stop()) {
672 set_current_state(TASK_RUNNING);
673 spin_unlock_bh(&pool->sp_lock);
674 return -EINTR;
675 }
676
Tom Tucker0f0257e2007-12-30 21:08:27 -0600677 add_wait_queue(&rqstp->rq_wait, &wait);
678 spin_unlock_bh(&pool->sp_lock);
679
Greg Banks03cf6c92009-01-13 21:26:36 +1100680 time_left = schedule_timeout(timeout);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600681
682 try_to_freeze();
683
684 spin_lock_bh(&pool->sp_lock);
685 remove_wait_queue(&rqstp->rq_wait, &wait);
Greg Banks03cf6c92009-01-13 21:26:36 +1100686 if (!time_left)
687 pool->sp_stats.threads_timedout++;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600688
689 xprt = rqstp->rq_xprt;
690 if (!xprt) {
691 svc_thread_dequeue(pool, rqstp);
692 spin_unlock_bh(&pool->sp_lock);
693 dprintk("svc: server %p, no data yet\n", rqstp);
Jeff Layton70867212008-02-07 16:34:54 -0500694 if (signalled() || kthread_should_stop())
695 return -EINTR;
696 else
697 return -EAGAIN;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600698 }
699 }
700 spin_unlock_bh(&pool->sp_lock);
701
702 len = 0;
J. Bruce Fields1b644b62010-02-28 16:33:31 -0500703 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
704 dprintk("svc_recv: found XPT_CLOSE\n");
705 svc_delete_xprt(xprt);
J. Bruce Fieldsca7896cd2010-10-25 14:12:40 -0400706 /* Leave XPT_BUSY set on the dead xprt: */
707 goto out;
708 }
709 if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
Tom Tucker0f0257e2007-12-30 21:08:27 -0600710 struct svc_xprt *newxpt;
711 newxpt = xprt->xpt_ops->xpo_accept(xprt);
712 if (newxpt) {
713 /*
714 * We know this module_get will succeed because the
715 * listener holds a reference too
716 */
717 __module_get(newxpt->xpt_class->xcl_owner);
718 svc_check_conn_limits(xprt->xpt_server);
719 spin_lock_bh(&serv->sv_lock);
720 set_bit(XPT_TEMP, &newxpt->xpt_flags);
721 list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
722 serv->sv_tmpcnt++;
723 if (serv->sv_temptimer.function == NULL) {
724 /* setup timer to age temp transports */
725 setup_timer(&serv->sv_temptimer,
726 svc_age_temp_xprts,
727 (unsigned long)serv);
728 mod_timer(&serv->sv_temptimer,
729 jiffies + svc_conn_age_period * HZ);
730 }
731 spin_unlock_bh(&serv->sv_lock);
732 svc_xprt_received(newxpt);
733 }
J. Bruce Fields9c335c02010-10-26 11:32:03 -0400734 } else if (xprt->xpt_ops->xpo_has_wspace(xprt)) {
Tom Tucker0f0257e2007-12-30 21:08:27 -0600735 dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
736 rqstp, pool->sp_id, xprt,
737 atomic_read(&xprt->xpt_ref.refcount));
738 rqstp->rq_deferred = svc_deferred_dequeue(xprt);
J. Bruce Fieldsca7896cd2010-10-25 14:12:40 -0400739 if (rqstp->rq_deferred)
Tom Tucker0f0257e2007-12-30 21:08:27 -0600740 len = svc_deferred_recv(rqstp);
J. Bruce Fieldsca7896cd2010-10-25 14:12:40 -0400741 else
Tom Tucker0f0257e2007-12-30 21:08:27 -0600742 len = xprt->xpt_ops->xpo_recvfrom(rqstp);
743 dprintk("svc: got len=%d\n", len);
744 }
J. Bruce Fieldsca7896cd2010-10-25 14:12:40 -0400745 svc_xprt_received(xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600746
747 /* No data, incomplete (TCP) read, or accept() */
J. Bruce Fieldsca7896cd2010-10-25 14:12:40 -0400748 if (len == 0 || len == -EAGAIN)
749 goto out;
750
Tom Tucker0f0257e2007-12-30 21:08:27 -0600751 clear_bit(XPT_OLD, &xprt->xpt_flags);
752
753 rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
754 rqstp->rq_chandle.defer = svc_defer;
755
756 if (serv->sv_stats)
757 serv->sv_stats->netcnt++;
758 return len;
J. Bruce Fieldsca7896cd2010-10-25 14:12:40 -0400759out:
760 rqstp->rq_res.len = 0;
761 svc_xprt_release(rqstp);
762 return -EAGAIN;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600763}
Trond Myklebust24c37672008-12-23 16:30:12 -0500764EXPORT_SYMBOL_GPL(svc_recv);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600765
766/*
767 * Drop request
768 */
769void svc_drop(struct svc_rqst *rqstp)
770{
771 dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
772 svc_xprt_release(rqstp);
773}
Trond Myklebust24c37672008-12-23 16:30:12 -0500774EXPORT_SYMBOL_GPL(svc_drop);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600775
776/*
777 * Return reply to client.
778 */
779int svc_send(struct svc_rqst *rqstp)
780{
781 struct svc_xprt *xprt;
782 int len;
783 struct xdr_buf *xb;
784
785 xprt = rqstp->rq_xprt;
786 if (!xprt)
787 return -EFAULT;
788
789 /* release the receive skb before sending the reply */
790 rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
791
792 /* calculate over-all length */
793 xb = &rqstp->rq_res;
794 xb->len = xb->head[0].iov_len +
795 xb->page_len +
796 xb->tail[0].iov_len;
797
798 /* Grab mutex to serialize outgoing data. */
799 mutex_lock(&xprt->xpt_mutex);
800 if (test_bit(XPT_DEAD, &xprt->xpt_flags))
801 len = -ENOTCONN;
802 else
803 len = xprt->xpt_ops->xpo_sendto(rqstp);
804 mutex_unlock(&xprt->xpt_mutex);
Rahul Iyer4cfc7e62009-09-10 17:32:28 +0300805 rpc_wake_up(&xprt->xpt_bc_pending);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600806 svc_xprt_release(rqstp);
807
808 if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
809 return 0;
810 return len;
811}
812
813/*
814 * Timer function to close old temporary transports, using
815 * a mark-and-sweep algorithm.
816 */
817static void svc_age_temp_xprts(unsigned long closure)
818{
819 struct svc_serv *serv = (struct svc_serv *)closure;
820 struct svc_xprt *xprt;
821 struct list_head *le, *next;
822 LIST_HEAD(to_be_aged);
823
824 dprintk("svc_age_temp_xprts\n");
825
826 if (!spin_trylock_bh(&serv->sv_lock)) {
827 /* busy, try again 1 sec later */
828 dprintk("svc_age_temp_xprts: busy\n");
829 mod_timer(&serv->sv_temptimer, jiffies + HZ);
830 return;
831 }
832
833 list_for_each_safe(le, next, &serv->sv_tempsocks) {
834 xprt = list_entry(le, struct svc_xprt, xpt_list);
835
836 /* First time through, just mark it OLD. Second time
837 * through, close it. */
838 if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
839 continue;
Joe Perchesf64f9e72009-11-29 16:55:45 -0800840 if (atomic_read(&xprt->xpt_ref.refcount) > 1 ||
841 test_bit(XPT_BUSY, &xprt->xpt_flags))
Tom Tucker0f0257e2007-12-30 21:08:27 -0600842 continue;
843 svc_xprt_get(xprt);
844 list_move(le, &to_be_aged);
845 set_bit(XPT_CLOSE, &xprt->xpt_flags);
846 set_bit(XPT_DETACHED, &xprt->xpt_flags);
847 }
848 spin_unlock_bh(&serv->sv_lock);
849
850 while (!list_empty(&to_be_aged)) {
851 le = to_be_aged.next;
852 /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
853 list_del_init(le);
854 xprt = list_entry(le, struct svc_xprt, xpt_list);
855
856 dprintk("queuing xprt %p for closing\n", xprt);
857
858 /* a thread will dequeue and close it soon */
859 svc_xprt_enqueue(xprt);
860 svc_xprt_put(xprt);
861 }
862
863 mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
864}
865
J. Bruce Fieldsedc7a892010-03-22 15:37:17 -0400866static void call_xpt_users(struct svc_xprt *xprt)
867{
868 struct svc_xpt_user *u;
869
870 spin_lock(&xprt->xpt_lock);
871 while (!list_empty(&xprt->xpt_users)) {
872 u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
873 list_del(&u->list);
874 u->callback(u);
875 }
876 spin_unlock(&xprt->xpt_lock);
877}
878
Tom Tucker0f0257e2007-12-30 21:08:27 -0600879/*
880 * Remove a dead transport
881 */
J. Bruce Fields7710ec32011-11-25 18:44:05 -0500882static void svc_delete_xprt(struct svc_xprt *xprt)
Tom Tucker0f0257e2007-12-30 21:08:27 -0600883{
884 struct svc_serv *serv = xprt->xpt_server;
Tom Tucker22945e42009-01-05 15:21:19 -0600885 struct svc_deferred_req *dr;
886
887 /* Only do this once */
888 if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
J. Bruce Fieldsac9303e2010-10-23 11:16:10 -0400889 BUG();
Tom Tucker0f0257e2007-12-30 21:08:27 -0600890
891 dprintk("svc: svc_delete_xprt(%p)\n", xprt);
892 xprt->xpt_ops->xpo_detach(xprt);
893
894 spin_lock_bh(&serv->sv_lock);
895 if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
896 list_del_init(&xprt->xpt_list);
J. Bruce Fieldsb4f36f82011-11-29 17:00:26 -0500897 BUG_ON(!list_empty(&xprt->xpt_ready));
Tom Tucker22945e42009-01-05 15:21:19 -0600898 if (test_bit(XPT_TEMP, &xprt->xpt_flags))
899 serv->sv_tmpcnt--;
J. Bruce Fields788e69e2010-03-29 21:02:31 -0400900 spin_unlock_bh(&serv->sv_lock);
Tom Tucker22945e42009-01-05 15:21:19 -0600901
Neil Brownab1b18f2010-02-27 09:33:40 +1100902 while ((dr = svc_deferred_dequeue(xprt)) != NULL)
Tom Tucker22945e42009-01-05 15:21:19 -0600903 kfree(dr);
Tom Tucker22945e42009-01-05 15:21:19 -0600904
J. Bruce Fieldsedc7a892010-03-22 15:37:17 -0400905 call_xpt_users(xprt);
Tom Tucker22945e42009-01-05 15:21:19 -0600906 svc_xprt_put(xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600907}
908
909void svc_close_xprt(struct svc_xprt *xprt)
910{
911 set_bit(XPT_CLOSE, &xprt->xpt_flags);
912 if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
913 /* someone else will have to effect the close */
914 return;
J. Bruce Fieldsb1763312010-10-25 20:24:48 -0400915 /*
916 * We expect svc_close_xprt() to work even when no threads are
917 * running (e.g., while configuring the server before starting
918 * any threads), so if the transport isn't busy, we delete
919 * it ourself:
920 */
Tom Tucker0f0257e2007-12-30 21:08:27 -0600921 svc_delete_xprt(xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600922}
Tom Tuckera2178132007-12-30 21:08:35 -0600923EXPORT_SYMBOL_GPL(svc_close_xprt);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600924
J. Bruce Fields2fefb8a2011-11-29 11:35:35 -0500925static void svc_close_list(struct list_head *xprt_list)
Tom Tucker0f0257e2007-12-30 21:08:27 -0600926{
927 struct svc_xprt *xprt;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600928
J. Bruce Fieldsb4f36f82011-11-29 17:00:26 -0500929 list_for_each_entry(xprt, xprt_list, xpt_list) {
Tom Tucker0f0257e2007-12-30 21:08:27 -0600930 set_bit(XPT_CLOSE, &xprt->xpt_flags);
J. Bruce Fieldsb4f36f82011-11-29 17:00:26 -0500931 set_bit(XPT_BUSY, &xprt->xpt_flags);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600932 }
933}
934
J. Bruce Fields2fefb8a2011-11-29 11:35:35 -0500935void svc_close_all(struct svc_serv *serv)
936{
J. Bruce Fieldsb4f36f82011-11-29 17:00:26 -0500937 struct svc_pool *pool;
938 struct svc_xprt *xprt;
939 struct svc_xprt *tmp;
940 int i;
941
J. Bruce Fields2fefb8a2011-11-29 11:35:35 -0500942 svc_close_list(&serv->sv_tempsocks);
943 svc_close_list(&serv->sv_permsocks);
J. Bruce Fieldsb4f36f82011-11-29 17:00:26 -0500944
945 for (i = 0; i < serv->sv_nrpools; i++) {
946 pool = &serv->sv_pools[i];
947
948 spin_lock_bh(&pool->sp_lock);
949 while (!list_empty(&pool->sp_sockets)) {
950 xprt = list_first_entry(&pool->sp_sockets, struct svc_xprt, xpt_ready);
951 list_del_init(&xprt->xpt_ready);
952 }
953 spin_unlock_bh(&pool->sp_lock);
954 }
955 /*
956 * At this point the sp_sockets lists will stay empty, since
957 * svc_enqueue will not add new entries without taking the
958 * sp_lock and checking XPT_BUSY.
959 */
960 list_for_each_entry_safe(xprt, tmp, &serv->sv_tempsocks, xpt_list)
961 svc_delete_xprt(xprt);
962 list_for_each_entry_safe(xprt, tmp, &serv->sv_permsocks, xpt_list)
963 svc_delete_xprt(xprt);
964
J. Bruce Fields2fefb8a2011-11-29 11:35:35 -0500965 BUG_ON(!list_empty(&serv->sv_permsocks));
966 BUG_ON(!list_empty(&serv->sv_tempsocks));
J. Bruce Fields2fefb8a2011-11-29 11:35:35 -0500967}
968
Tom Tucker0f0257e2007-12-30 21:08:27 -0600969/*
970 * Handle defer and revisit of requests
971 */
972
973static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
974{
975 struct svc_deferred_req *dr =
976 container_of(dreq, struct svc_deferred_req, handle);
977 struct svc_xprt *xprt = dr->xprt;
978
Tom Tucker22945e42009-01-05 15:21:19 -0600979 spin_lock(&xprt->xpt_lock);
980 set_bit(XPT_DEFERRED, &xprt->xpt_flags);
981 if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
982 spin_unlock(&xprt->xpt_lock);
983 dprintk("revisit canceled\n");
Tom Tucker0f0257e2007-12-30 21:08:27 -0600984 svc_xprt_put(xprt);
985 kfree(dr);
986 return;
987 }
988 dprintk("revisit queued\n");
989 dr->xprt = NULL;
Tom Tucker0f0257e2007-12-30 21:08:27 -0600990 list_add(&dr->handle.recent, &xprt->xpt_deferred);
991 spin_unlock(&xprt->xpt_lock);
Tom Tucker0f0257e2007-12-30 21:08:27 -0600992 svc_xprt_enqueue(xprt);
993 svc_xprt_put(xprt);
994}
995
Tom Tucker260c1d12007-12-30 21:08:29 -0600996/*
997 * Save the request off for later processing. The request buffer looks
998 * like this:
999 *
1000 * <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
1001 *
1002 * This code can only handle requests that consist of an xprt-header
1003 * and rpc-header.
1004 */
Tom Tucker0f0257e2007-12-30 21:08:27 -06001005static struct cache_deferred_req *svc_defer(struct cache_req *req)
1006{
1007 struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
Tom Tucker0f0257e2007-12-30 21:08:27 -06001008 struct svc_deferred_req *dr;
1009
Andy Adamson2f425872009-04-03 08:27:32 +03001010 if (rqstp->rq_arg.page_len || !rqstp->rq_usedeferral)
Tom Tucker0f0257e2007-12-30 21:08:27 -06001011 return NULL; /* if more than a page, give up FIXME */
1012 if (rqstp->rq_deferred) {
1013 dr = rqstp->rq_deferred;
1014 rqstp->rq_deferred = NULL;
1015 } else {
Tom Tucker260c1d12007-12-30 21:08:29 -06001016 size_t skip;
1017 size_t size;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001018 /* FIXME maybe discard if size too large */
Tom Tucker260c1d12007-12-30 21:08:29 -06001019 size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001020 dr = kmalloc(size, GFP_KERNEL);
1021 if (dr == NULL)
1022 return NULL;
1023
1024 dr->handle.owner = rqstp->rq_server;
1025 dr->prot = rqstp->rq_prot;
1026 memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
1027 dr->addrlen = rqstp->rq_addrlen;
1028 dr->daddr = rqstp->rq_daddr;
1029 dr->argslen = rqstp->rq_arg.len >> 2;
Tom Tucker260c1d12007-12-30 21:08:29 -06001030 dr->xprt_hlen = rqstp->rq_xprt_hlen;
1031
1032 /* back up head to the start of the buffer and copy */
1033 skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1034 memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
1035 dr->argslen << 2);
Tom Tucker0f0257e2007-12-30 21:08:27 -06001036 }
1037 svc_xprt_get(rqstp->rq_xprt);
1038 dr->xprt = rqstp->rq_xprt;
J. Bruce Fields9e701c62011-01-02 21:56:36 -05001039 rqstp->rq_dropme = true;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001040
1041 dr->handle.revisit = svc_revisit;
1042 return &dr->handle;
1043}
1044
1045/*
1046 * recv data from a deferred request into an active one
1047 */
1048static int svc_deferred_recv(struct svc_rqst *rqstp)
1049{
1050 struct svc_deferred_req *dr = rqstp->rq_deferred;
1051
Tom Tucker260c1d12007-12-30 21:08:29 -06001052 /* setup iov_base past transport header */
1053 rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
1054 /* The iov_len does not include the transport header bytes */
1055 rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001056 rqstp->rq_arg.page_len = 0;
Tom Tucker260c1d12007-12-30 21:08:29 -06001057 /* The rq_arg.len includes the transport header bytes */
1058 rqstp->rq_arg.len = dr->argslen<<2;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001059 rqstp->rq_prot = dr->prot;
1060 memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
1061 rqstp->rq_addrlen = dr->addrlen;
Tom Tucker260c1d12007-12-30 21:08:29 -06001062 /* Save off transport header len in case we get deferred again */
1063 rqstp->rq_xprt_hlen = dr->xprt_hlen;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001064 rqstp->rq_daddr = dr->daddr;
1065 rqstp->rq_respages = rqstp->rq_pages;
Tom Tucker260c1d12007-12-30 21:08:29 -06001066 return (dr->argslen<<2) - dr->xprt_hlen;
Tom Tucker0f0257e2007-12-30 21:08:27 -06001067}
1068
1069
1070static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
1071{
1072 struct svc_deferred_req *dr = NULL;
1073
1074 if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
1075 return NULL;
1076 spin_lock(&xprt->xpt_lock);
Tom Tucker0f0257e2007-12-30 21:08:27 -06001077 if (!list_empty(&xprt->xpt_deferred)) {
1078 dr = list_entry(xprt->xpt_deferred.next,
1079 struct svc_deferred_req,
1080 handle.recent);
1081 list_del_init(&dr->handle.recent);
J. Bruce Fields62bac4a2010-10-25 12:50:15 -04001082 } else
1083 clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
Tom Tucker0f0257e2007-12-30 21:08:27 -06001084 spin_unlock(&xprt->xpt_lock);
1085 return dr;
1086}
Tom Tucker7fcb98d2007-12-30 21:08:33 -06001087
Chuck Lever156e6202009-03-18 20:45:58 -04001088/**
1089 * svc_find_xprt - find an RPC transport instance
1090 * @serv: pointer to svc_serv to search
1091 * @xcl_name: C string containing transport's class name
1092 * @af: Address family of transport's local address
1093 * @port: transport's IP port number
1094 *
Tom Tucker7fcb98d2007-12-30 21:08:33 -06001095 * Return the transport instance pointer for the endpoint accepting
1096 * connections/peer traffic from the specified transport class,
1097 * address family and port.
1098 *
1099 * Specifying 0 for the address family or port is effectively a
1100 * wild-card, and will result in matching the first transport in the
1101 * service's list that has a matching class name.
1102 */
Chuck Lever156e6202009-03-18 20:45:58 -04001103struct svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
1104 const sa_family_t af, const unsigned short port)
Tom Tucker7fcb98d2007-12-30 21:08:33 -06001105{
1106 struct svc_xprt *xprt;
1107 struct svc_xprt *found = NULL;
1108
1109 /* Sanity check the args */
Chuck Lever156e6202009-03-18 20:45:58 -04001110 if (serv == NULL || xcl_name == NULL)
Tom Tucker7fcb98d2007-12-30 21:08:33 -06001111 return found;
1112
1113 spin_lock_bh(&serv->sv_lock);
1114 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
1115 if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
1116 continue;
1117 if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
1118 continue;
Chuck Lever156e6202009-03-18 20:45:58 -04001119 if (port != 0 && port != svc_xprt_local_port(xprt))
Tom Tucker7fcb98d2007-12-30 21:08:33 -06001120 continue;
1121 found = xprt;
Tom Tuckera2178132007-12-30 21:08:35 -06001122 svc_xprt_get(xprt);
Tom Tucker7fcb98d2007-12-30 21:08:33 -06001123 break;
1124 }
1125 spin_unlock_bh(&serv->sv_lock);
1126 return found;
1127}
1128EXPORT_SYMBOL_GPL(svc_find_xprt);
Tom Tucker9571af12007-12-30 21:08:37 -06001129
Chuck Lever335c54b2009-04-23 19:32:25 -04001130static int svc_one_xprt_name(const struct svc_xprt *xprt,
1131 char *pos, int remaining)
1132{
1133 int len;
1134
1135 len = snprintf(pos, remaining, "%s %u\n",
1136 xprt->xpt_class->xcl_name,
1137 svc_xprt_local_port(xprt));
1138 if (len >= remaining)
1139 return -ENAMETOOLONG;
1140 return len;
1141}
1142
1143/**
1144 * svc_xprt_names - format a buffer with a list of transport names
1145 * @serv: pointer to an RPC service
1146 * @buf: pointer to a buffer to be filled in
1147 * @buflen: length of buffer to be filled in
1148 *
1149 * Fills in @buf with a string containing a list of transport names,
1150 * each name terminated with '\n'.
1151 *
1152 * Returns positive length of the filled-in string on success; otherwise
1153 * a negative errno value is returned if an error occurs.
Tom Tucker9571af12007-12-30 21:08:37 -06001154 */
Chuck Lever335c54b2009-04-23 19:32:25 -04001155int svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen)
Tom Tucker9571af12007-12-30 21:08:37 -06001156{
1157 struct svc_xprt *xprt;
Chuck Lever335c54b2009-04-23 19:32:25 -04001158 int len, totlen;
1159 char *pos;
Tom Tucker9571af12007-12-30 21:08:37 -06001160
1161 /* Sanity check args */
1162 if (!serv)
1163 return 0;
1164
1165 spin_lock_bh(&serv->sv_lock);
Chuck Lever335c54b2009-04-23 19:32:25 -04001166
1167 pos = buf;
1168 totlen = 0;
Tom Tucker9571af12007-12-30 21:08:37 -06001169 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
Chuck Lever335c54b2009-04-23 19:32:25 -04001170 len = svc_one_xprt_name(xprt, pos, buflen - totlen);
1171 if (len < 0) {
1172 *buf = '\0';
1173 totlen = len;
1174 }
1175 if (len <= 0)
Tom Tucker9571af12007-12-30 21:08:37 -06001176 break;
Chuck Lever335c54b2009-04-23 19:32:25 -04001177
1178 pos += len;
Tom Tucker9571af12007-12-30 21:08:37 -06001179 totlen += len;
1180 }
Chuck Lever335c54b2009-04-23 19:32:25 -04001181
Tom Tucker9571af12007-12-30 21:08:37 -06001182 spin_unlock_bh(&serv->sv_lock);
1183 return totlen;
1184}
1185EXPORT_SYMBOL_GPL(svc_xprt_names);
Greg Banks03cf6c92009-01-13 21:26:36 +11001186
1187
1188/*----------------------------------------------------------------------------*/
1189
1190static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
1191{
1192 unsigned int pidx = (unsigned int)*pos;
1193 struct svc_serv *serv = m->private;
1194
1195 dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
1196
Greg Banks03cf6c92009-01-13 21:26:36 +11001197 if (!pidx)
1198 return SEQ_START_TOKEN;
1199 return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);
1200}
1201
1202static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)
1203{
1204 struct svc_pool *pool = p;
1205 struct svc_serv *serv = m->private;
1206
1207 dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);
1208
1209 if (p == SEQ_START_TOKEN) {
1210 pool = &serv->sv_pools[0];
1211 } else {
1212 unsigned int pidx = (pool - &serv->sv_pools[0]);
1213 if (pidx < serv->sv_nrpools-1)
1214 pool = &serv->sv_pools[pidx+1];
1215 else
1216 pool = NULL;
1217 }
1218 ++*pos;
1219 return pool;
1220}
1221
1222static void svc_pool_stats_stop(struct seq_file *m, void *p)
1223{
Greg Banks03cf6c92009-01-13 21:26:36 +11001224}
1225
1226static int svc_pool_stats_show(struct seq_file *m, void *p)
1227{
1228 struct svc_pool *pool = p;
1229
1230 if (p == SEQ_START_TOKEN) {
J. Bruce Fields78c210e2009-08-06 15:41:34 -04001231 seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
Greg Banks03cf6c92009-01-13 21:26:36 +11001232 return 0;
1233 }
1234
J. Bruce Fields78c210e2009-08-06 15:41:34 -04001235 seq_printf(m, "%u %lu %lu %lu %lu\n",
Greg Banks03cf6c92009-01-13 21:26:36 +11001236 pool->sp_id,
1237 pool->sp_stats.packets,
1238 pool->sp_stats.sockets_queued,
1239 pool->sp_stats.threads_woken,
Greg Banks03cf6c92009-01-13 21:26:36 +11001240 pool->sp_stats.threads_timedout);
1241
1242 return 0;
1243}
1244
1245static const struct seq_operations svc_pool_stats_seq_ops = {
1246 .start = svc_pool_stats_start,
1247 .next = svc_pool_stats_next,
1248 .stop = svc_pool_stats_stop,
1249 .show = svc_pool_stats_show,
1250};
1251
1252int svc_pool_stats_open(struct svc_serv *serv, struct file *file)
1253{
1254 int err;
1255
1256 err = seq_open(file, &svc_pool_stats_seq_ops);
1257 if (!err)
1258 ((struct seq_file *) file->private_data)->private = serv;
1259 return err;
1260}
1261EXPORT_SYMBOL(svc_pool_stats_open);
1262
1263/*----------------------------------------------------------------------------*/