Commit | Line | Data |
---|---|---|
1d8206b9 TT |
1 | /* |
2 | * linux/net/sunrpc/svc_xprt.c | |
3 | * | |
4 | * Author: Tom Tucker <tom@opengridcomputing.com> | |
5 | */ | |
6 | ||
7 | #include <linux/sched.h> | |
8 | #include <linux/errno.h> | |
1d8206b9 | 9 | #include <linux/freezer.h> |
7086721f | 10 | #include <linux/kthread.h> |
1d8206b9 | 11 | #include <net/sock.h> |
1d8206b9 TT |
12 | #include <linux/sunrpc/stats.h> |
13 | #include <linux/sunrpc/svc_xprt.h> | |
14 | ||
15 | #define RPCDBG_FACILITY RPCDBG_SVCXPRT | |
16 | ||
0f0257ea TT |
17 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); |
18 | static int svc_deferred_recv(struct svc_rqst *rqstp); | |
19 | static struct cache_deferred_req *svc_defer(struct cache_req *req); | |
20 | static void svc_age_temp_xprts(unsigned long closure); | |
21 | ||
22 | /* apparently the "standard" is that clients close | |
23 | * idle connections after 5 minutes, servers after | |
24 | * 6 minutes | |
25 | * http://www.connectathon.org/talks96/nfstcp.pdf | |
26 | */ | |
27 | static int svc_conn_age_period = 6*60; | |
28 | ||
1d8206b9 TT |
29 | /* List of registered transport classes */ |
30 | static DEFINE_SPINLOCK(svc_xprt_class_lock); | |
31 | static LIST_HEAD(svc_xprt_class_list); | |
32 | ||
0f0257ea TT |
33 | /* SMP locking strategy: |
34 | * | |
35 | * svc_pool->sp_lock protects most of the fields of that pool. | |
36 | * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. | |
37 | * when both need to be taken (rare), svc_serv->sv_lock is first. | |
38 | * BKL protects svc_serv->sv_nrthread. | |
39 | * svc_sock->sk_lock protects the svc_sock->sk_deferred list | |
40 | * and the ->sk_info_authunix cache. | |
41 | * | |
42 | * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being | |
43 | * enqueued multiply. During normal transport processing this bit | |
44 | * is set by svc_xprt_enqueue and cleared by svc_xprt_received. | |
45 | * Providers should not manipulate this bit directly. | |
46 | * | |
47 | * Some flags can be set to certain values at any time | |
48 | * providing that certain rules are followed: | |
49 | * | |
50 | * XPT_CONN, XPT_DATA: | |
51 | * - Can be set or cleared at any time. | |
52 | * - After a set, svc_xprt_enqueue must be called to enqueue | |
53 | * the transport for processing. | |
54 | * - After a clear, the transport must be read/accepted. | |
55 | * If this succeeds, it must be set again. | |
56 | * XPT_CLOSE: | |
57 | * - Can set at any time. It is never cleared. | |
58 | * XPT_DEAD: | |
59 | * - Can only be set while XPT_BUSY is held which ensures | |
60 | * that no other thread will be using the transport or will | |
61 | * try to set XPT_DEAD. | |
62 | */ | |
63 | ||
1d8206b9 TT |
64 | int svc_reg_xprt_class(struct svc_xprt_class *xcl) |
65 | { | |
66 | struct svc_xprt_class *cl; | |
67 | int res = -EEXIST; | |
68 | ||
69 | dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); | |
70 | ||
71 | INIT_LIST_HEAD(&xcl->xcl_list); | |
72 | spin_lock(&svc_xprt_class_lock); | |
73 | /* Make sure there isn't already a class with the same name */ | |
74 | list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { | |
75 | if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) | |
76 | goto out; | |
77 | } | |
78 | list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); | |
79 | res = 0; | |
80 | out: | |
81 | spin_unlock(&svc_xprt_class_lock); | |
82 | return res; | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(svc_reg_xprt_class); | |
85 | ||
86 | void svc_unreg_xprt_class(struct svc_xprt_class *xcl) | |
87 | { | |
88 | dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); | |
89 | spin_lock(&svc_xprt_class_lock); | |
90 | list_del_init(&xcl->xcl_list); | |
91 | spin_unlock(&svc_xprt_class_lock); | |
92 | } | |
93 | EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); | |
94 | ||
dc9a16e4 TT |
95 | /* |
96 | * Format the transport list for printing | |
97 | */ | |
98 | int svc_print_xprts(char *buf, int maxlen) | |
99 | { | |
100 | struct list_head *le; | |
101 | char tmpstr[80]; | |
102 | int len = 0; | |
103 | buf[0] = '\0'; | |
104 | ||
105 | spin_lock(&svc_xprt_class_lock); | |
106 | list_for_each(le, &svc_xprt_class_list) { | |
107 | int slen; | |
108 | struct svc_xprt_class *xcl = | |
109 | list_entry(le, struct svc_xprt_class, xcl_list); | |
110 | ||
111 | sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload); | |
112 | slen = strlen(tmpstr); | |
113 | if (len + slen > maxlen) | |
114 | break; | |
115 | len += slen; | |
116 | strcat(buf, tmpstr); | |
117 | } | |
118 | spin_unlock(&svc_xprt_class_lock); | |
119 | ||
120 | return len; | |
121 | } | |
122 | ||
e1b3157f TT |
123 | static void svc_xprt_free(struct kref *kref) |
124 | { | |
125 | struct svc_xprt *xprt = | |
126 | container_of(kref, struct svc_xprt, xpt_ref); | |
127 | struct module *owner = xprt->xpt_class->xcl_owner; | |
def13d74 TT |
128 | if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags) |
129 | && xprt->xpt_auth_cache != NULL) | |
130 | svcauth_unix_info_release(xprt->xpt_auth_cache); | |
e1b3157f TT |
131 | xprt->xpt_ops->xpo_free(xprt); |
132 | module_put(owner); | |
133 | } | |
134 | ||
135 | void svc_xprt_put(struct svc_xprt *xprt) | |
136 | { | |
137 | kref_put(&xprt->xpt_ref, svc_xprt_free); | |
138 | } | |
139 | EXPORT_SYMBOL_GPL(svc_xprt_put); | |
140 | ||
1d8206b9 TT |
141 | /* |
142 | * Called by transport drivers to initialize the transport independent | |
143 | * portion of the transport instance. | |
144 | */ | |
bb5cf160 TT |
145 | void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt, |
146 | struct svc_serv *serv) | |
1d8206b9 TT |
147 | { |
148 | memset(xprt, 0, sizeof(*xprt)); | |
149 | xprt->xpt_class = xcl; | |
150 | xprt->xpt_ops = xcl->xcl_ops; | |
e1b3157f | 151 | kref_init(&xprt->xpt_ref); |
bb5cf160 | 152 | xprt->xpt_server = serv; |
7a182083 TT |
153 | INIT_LIST_HEAD(&xprt->xpt_list); |
154 | INIT_LIST_HEAD(&xprt->xpt_ready); | |
8c7b0172 | 155 | INIT_LIST_HEAD(&xprt->xpt_deferred); |
a50fea26 | 156 | mutex_init(&xprt->xpt_mutex); |
def13d74 | 157 | spin_lock_init(&xprt->xpt_lock); |
4e5caaa5 | 158 | set_bit(XPT_BUSY, &xprt->xpt_flags); |
1d8206b9 TT |
159 | } |
160 | EXPORT_SYMBOL_GPL(svc_xprt_init); | |
b700cbb1 | 161 | |
5dd248f6 CL |
162 | static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, |
163 | struct svc_serv *serv, | |
164 | unsigned short port, int flags) | |
b700cbb1 | 165 | { |
b700cbb1 TT |
166 | struct sockaddr_in sin = { |
167 | .sin_family = AF_INET, | |
e6f1cebf | 168 | .sin_addr.s_addr = htonl(INADDR_ANY), |
b700cbb1 TT |
169 | .sin_port = htons(port), |
170 | }; | |
5dd248f6 CL |
171 | struct sockaddr_in6 sin6 = { |
172 | .sin6_family = AF_INET6, | |
173 | .sin6_addr = IN6ADDR_ANY_INIT, | |
174 | .sin6_port = htons(port), | |
175 | }; | |
176 | struct sockaddr *sap; | |
177 | size_t len; | |
178 | ||
179 | switch (serv->sv_family) { | |
180 | case AF_INET: | |
181 | sap = (struct sockaddr *)&sin; | |
182 | len = sizeof(sin); | |
183 | break; | |
184 | case AF_INET6: | |
185 | sap = (struct sockaddr *)&sin6; | |
186 | len = sizeof(sin6); | |
187 | break; | |
188 | default: | |
189 | return ERR_PTR(-EAFNOSUPPORT); | |
190 | } | |
191 | ||
192 | return xcl->xcl_ops->xpo_create(serv, sap, len, flags); | |
193 | } | |
194 | ||
195 | int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port, | |
196 | int flags) | |
197 | { | |
198 | struct svc_xprt_class *xcl; | |
199 | ||
b700cbb1 TT |
200 | dprintk("svc: creating transport %s[%d]\n", xprt_name, port); |
201 | spin_lock(&svc_xprt_class_lock); | |
202 | list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { | |
4e5caaa5 TT |
203 | struct svc_xprt *newxprt; |
204 | ||
205 | if (strcmp(xprt_name, xcl->xcl_name)) | |
206 | continue; | |
207 | ||
208 | if (!try_module_get(xcl->xcl_owner)) | |
209 | goto err; | |
210 | ||
211 | spin_unlock(&svc_xprt_class_lock); | |
5dd248f6 | 212 | newxprt = __svc_xpo_create(xcl, serv, port, flags); |
4e5caaa5 TT |
213 | if (IS_ERR(newxprt)) { |
214 | module_put(xcl->xcl_owner); | |
215 | return PTR_ERR(newxprt); | |
b700cbb1 | 216 | } |
4e5caaa5 TT |
217 | |
218 | clear_bit(XPT_TEMP, &newxprt->xpt_flags); | |
219 | spin_lock_bh(&serv->sv_lock); | |
220 | list_add(&newxprt->xpt_list, &serv->sv_permsocks); | |
221 | spin_unlock_bh(&serv->sv_lock); | |
222 | clear_bit(XPT_BUSY, &newxprt->xpt_flags); | |
223 | return svc_xprt_local_port(newxprt); | |
b700cbb1 | 224 | } |
4e5caaa5 | 225 | err: |
b700cbb1 TT |
226 | spin_unlock(&svc_xprt_class_lock); |
227 | dprintk("svc: transport %s not found\n", xprt_name); | |
4e5caaa5 | 228 | return -ENOENT; |
b700cbb1 TT |
229 | } |
230 | EXPORT_SYMBOL_GPL(svc_create_xprt); | |
9dbc240f TT |
231 | |
232 | /* | |
233 | * Copy the local and remote xprt addresses to the rqstp structure | |
234 | */ | |
235 | void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) | |
236 | { | |
237 | struct sockaddr *sin; | |
238 | ||
239 | memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); | |
240 | rqstp->rq_addrlen = xprt->xpt_remotelen; | |
241 | ||
242 | /* | |
243 | * Destination address in request is needed for binding the | |
244 | * source address in RPC replies/callbacks later. | |
245 | */ | |
246 | sin = (struct sockaddr *)&xprt->xpt_local; | |
247 | switch (sin->sa_family) { | |
248 | case AF_INET: | |
249 | rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr; | |
250 | break; | |
251 | case AF_INET6: | |
252 | rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr; | |
253 | break; | |
254 | } | |
255 | } | |
256 | EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); | |
257 | ||
0f0257ea TT |
258 | /** |
259 | * svc_print_addr - Format rq_addr field for printing | |
260 | * @rqstp: svc_rqst struct containing address to print | |
261 | * @buf: target buffer for formatted address | |
262 | * @len: length of target buffer | |
263 | * | |
264 | */ | |
265 | char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) | |
266 | { | |
267 | return __svc_print_addr(svc_addr(rqstp), buf, len); | |
268 | } | |
269 | EXPORT_SYMBOL_GPL(svc_print_addr); | |
270 | ||
271 | /* | |
272 | * Queue up an idle server thread. Must have pool->sp_lock held. | |
273 | * Note: this is really a stack rather than a queue, so that we only | |
274 | * use as many different threads as we need, and the rest don't pollute | |
275 | * the cache. | |
276 | */ | |
277 | static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp) | |
278 | { | |
279 | list_add(&rqstp->rq_list, &pool->sp_threads); | |
280 | } | |
281 | ||
282 | /* | |
283 | * Dequeue an nfsd thread. Must have pool->sp_lock held. | |
284 | */ | |
285 | static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp) | |
286 | { | |
287 | list_del(&rqstp->rq_list); | |
288 | } | |
289 | ||
290 | /* | |
291 | * Queue up a transport with data pending. If there are idle nfsd | |
292 | * processes, wake 'em up. | |
293 | * | |
294 | */ | |
295 | void svc_xprt_enqueue(struct svc_xprt *xprt) | |
296 | { | |
297 | struct svc_serv *serv = xprt->xpt_server; | |
298 | struct svc_pool *pool; | |
299 | struct svc_rqst *rqstp; | |
300 | int cpu; | |
301 | ||
302 | if (!(xprt->xpt_flags & | |
303 | ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED)))) | |
304 | return; | |
0f0257ea TT |
305 | |
306 | cpu = get_cpu(); | |
307 | pool = svc_pool_for_cpu(xprt->xpt_server, cpu); | |
308 | put_cpu(); | |
309 | ||
310 | spin_lock_bh(&pool->sp_lock); | |
311 | ||
312 | if (!list_empty(&pool->sp_threads) && | |
313 | !list_empty(&pool->sp_sockets)) | |
314 | printk(KERN_ERR | |
315 | "svc_xprt_enqueue: " | |
316 | "threads and transports both waiting??\n"); | |
317 | ||
318 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) { | |
319 | /* Don't enqueue dead transports */ | |
320 | dprintk("svc: transport %p is dead, not enqueued\n", xprt); | |
321 | goto out_unlock; | |
322 | } | |
323 | ||
324 | /* Mark transport as busy. It will remain in this state until | |
325 | * the provider calls svc_xprt_received. We update XPT_BUSY | |
326 | * atomically because it also guards against trying to enqueue | |
327 | * the transport twice. | |
328 | */ | |
329 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { | |
330 | /* Don't enqueue transport while already enqueued */ | |
331 | dprintk("svc: transport %p busy, not enqueued\n", xprt); | |
332 | goto out_unlock; | |
333 | } | |
334 | BUG_ON(xprt->xpt_pool != NULL); | |
335 | xprt->xpt_pool = pool; | |
336 | ||
337 | /* Handle pending connection */ | |
338 | if (test_bit(XPT_CONN, &xprt->xpt_flags)) | |
339 | goto process; | |
340 | ||
341 | /* Handle close in-progress */ | |
342 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) | |
343 | goto process; | |
344 | ||
345 | /* Check if we have space to reply to a request */ | |
346 | if (!xprt->xpt_ops->xpo_has_wspace(xprt)) { | |
347 | /* Don't enqueue while not enough space for reply */ | |
348 | dprintk("svc: no write space, transport %p not enqueued\n", | |
349 | xprt); | |
350 | xprt->xpt_pool = NULL; | |
351 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
352 | goto out_unlock; | |
353 | } | |
354 | ||
355 | process: | |
356 | if (!list_empty(&pool->sp_threads)) { | |
357 | rqstp = list_entry(pool->sp_threads.next, | |
358 | struct svc_rqst, | |
359 | rq_list); | |
360 | dprintk("svc: transport %p served by daemon %p\n", | |
361 | xprt, rqstp); | |
362 | svc_thread_dequeue(pool, rqstp); | |
363 | if (rqstp->rq_xprt) | |
364 | printk(KERN_ERR | |
365 | "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", | |
366 | rqstp, rqstp->rq_xprt); | |
367 | rqstp->rq_xprt = xprt; | |
368 | svc_xprt_get(xprt); | |
369 | rqstp->rq_reserved = serv->sv_max_mesg; | |
370 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); | |
371 | BUG_ON(xprt->xpt_pool != pool); | |
372 | wake_up(&rqstp->rq_wait); | |
373 | } else { | |
374 | dprintk("svc: transport %p put into queue\n", xprt); | |
375 | list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); | |
376 | BUG_ON(xprt->xpt_pool != pool); | |
377 | } | |
378 | ||
379 | out_unlock: | |
380 | spin_unlock_bh(&pool->sp_lock); | |
381 | } | |
382 | EXPORT_SYMBOL_GPL(svc_xprt_enqueue); | |
383 | ||
384 | /* | |
385 | * Dequeue the first transport. Must be called with the pool->sp_lock held. | |
386 | */ | |
387 | static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) | |
388 | { | |
389 | struct svc_xprt *xprt; | |
390 | ||
391 | if (list_empty(&pool->sp_sockets)) | |
392 | return NULL; | |
393 | ||
394 | xprt = list_entry(pool->sp_sockets.next, | |
395 | struct svc_xprt, xpt_ready); | |
396 | list_del_init(&xprt->xpt_ready); | |
397 | ||
398 | dprintk("svc: transport %p dequeued, inuse=%d\n", | |
399 | xprt, atomic_read(&xprt->xpt_ref.refcount)); | |
400 | ||
401 | return xprt; | |
402 | } | |
403 | ||
404 | /* | |
405 | * svc_xprt_received conditionally queues the transport for processing | |
406 | * by another thread. The caller must hold the XPT_BUSY bit and must | |
407 | * not thereafter touch transport data. | |
408 | * | |
409 | * Note: XPT_DATA only gets cleared when a read-attempt finds no (or | |
410 | * insufficient) data. | |
411 | */ | |
412 | void svc_xprt_received(struct svc_xprt *xprt) | |
413 | { | |
414 | BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags)); | |
415 | xprt->xpt_pool = NULL; | |
416 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
417 | svc_xprt_enqueue(xprt); | |
418 | } | |
419 | EXPORT_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 | */ | |
431 | void 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 | } | |
24c3767e | 443 | EXPORT_SYMBOL_GPL(svc_reserve); |
0f0257ea TT |
444 | |
445 | static 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 | ||
2779e3ae TT |
451 | kfree(rqstp->rq_deferred); |
452 | rqstp->rq_deferred = NULL; | |
453 | ||
0f0257ea TT |
454 | 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 | */ | |
480 | void 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 | } | |
24c3767e | 504 | EXPORT_SYMBOL_GPL(svc_wake_up); |
0f0257ea TT |
505 | |
506 | int 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 | /* | |
c9233eb7 JL |
521 | * 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. | |
0f0257ea TT |
525 | * |
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. | |
c9233eb7 JL |
533 | * |
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 | |
0f0257ea TT |
537 | */ |
538 | static void svc_check_conn_limits(struct svc_serv *serv) | |
539 | { | |
c9233eb7 JL |
540 | unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn : |
541 | (serv->sv_nrthreads+3) * 20; | |
542 | ||
543 | if (serv->sv_tmpcnt > limit) { | |
0f0257ea TT |
544 | 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 " | |
c9233eb7 JL |
550 | "connections, consider increasing %s\n", |
551 | serv->sv_name, serv->sv_maxconn ? | |
552 | "the max number of connections." : | |
553 | "the number of threads."); | |
0f0257ea TT |
554 | } |
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 | */ | |
579 | int 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); | |
588 | ||
589 | dprintk("svc: server %p waiting for data (to = %ld)\n", | |
590 | rqstp, timeout); | |
591 | ||
592 | if (rqstp->rq_xprt) | |
593 | printk(KERN_ERR | |
594 | "svc_recv: service %p, transport not NULL!\n", | |
595 | rqstp); | |
596 | if (waitqueue_active(&rqstp->rq_wait)) | |
597 | printk(KERN_ERR | |
598 | "svc_recv: service %p, wait queue active!\n", | |
599 | rqstp); | |
600 | ||
601 | /* now allocate needed pages. If we get a failure, sleep briefly */ | |
602 | pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; | |
603 | for (i = 0; i < pages ; i++) | |
604 | while (rqstp->rq_pages[i] == NULL) { | |
605 | struct page *p = alloc_page(GFP_KERNEL); | |
606 | if (!p) { | |
7b54fe61 JL |
607 | set_current_state(TASK_INTERRUPTIBLE); |
608 | if (signalled() || kthread_should_stop()) { | |
609 | set_current_state(TASK_RUNNING); | |
7086721f | 610 | return -EINTR; |
7b54fe61 JL |
611 | } |
612 | schedule_timeout(msecs_to_jiffies(500)); | |
0f0257ea TT |
613 | } |
614 | rqstp->rq_pages[i] = p; | |
615 | } | |
616 | rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ | |
617 | BUG_ON(pages >= RPCSVC_MAXPAGES); | |
618 | ||
619 | /* Make arg->head point to first page and arg->pages point to rest */ | |
620 | arg = &rqstp->rq_arg; | |
621 | arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); | |
622 | arg->head[0].iov_len = PAGE_SIZE; | |
623 | arg->pages = rqstp->rq_pages + 1; | |
624 | arg->page_base = 0; | |
625 | /* save at least one page for response */ | |
626 | arg->page_len = (pages-2)*PAGE_SIZE; | |
627 | arg->len = (pages-1)*PAGE_SIZE; | |
628 | arg->tail[0].iov_len = 0; | |
629 | ||
630 | try_to_freeze(); | |
631 | cond_resched(); | |
7086721f | 632 | if (signalled() || kthread_should_stop()) |
0f0257ea TT |
633 | return -EINTR; |
634 | ||
635 | spin_lock_bh(&pool->sp_lock); | |
636 | xprt = svc_xprt_dequeue(pool); | |
637 | if (xprt) { | |
638 | rqstp->rq_xprt = xprt; | |
639 | svc_xprt_get(xprt); | |
640 | rqstp->rq_reserved = serv->sv_max_mesg; | |
641 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); | |
642 | } else { | |
643 | /* No data pending. Go to sleep */ | |
644 | svc_thread_enqueue(pool, rqstp); | |
645 | ||
646 | /* | |
647 | * We have to be able to interrupt this wait | |
648 | * to bring down the daemons ... | |
649 | */ | |
650 | set_current_state(TASK_INTERRUPTIBLE); | |
7086721f JL |
651 | |
652 | /* | |
653 | * checking kthread_should_stop() here allows us to avoid | |
654 | * locking and signalling when stopping kthreads that call | |
655 | * svc_recv. If the thread has already been woken up, then | |
656 | * we can exit here without sleeping. If not, then it | |
657 | * it'll be woken up quickly during the schedule_timeout | |
658 | */ | |
659 | if (kthread_should_stop()) { | |
660 | set_current_state(TASK_RUNNING); | |
661 | spin_unlock_bh(&pool->sp_lock); | |
662 | return -EINTR; | |
663 | } | |
664 | ||
0f0257ea TT |
665 | add_wait_queue(&rqstp->rq_wait, &wait); |
666 | spin_unlock_bh(&pool->sp_lock); | |
667 | ||
668 | schedule_timeout(timeout); | |
669 | ||
670 | try_to_freeze(); | |
671 | ||
672 | spin_lock_bh(&pool->sp_lock); | |
673 | remove_wait_queue(&rqstp->rq_wait, &wait); | |
674 | ||
675 | xprt = rqstp->rq_xprt; | |
676 | if (!xprt) { | |
677 | svc_thread_dequeue(pool, rqstp); | |
678 | spin_unlock_bh(&pool->sp_lock); | |
679 | dprintk("svc: server %p, no data yet\n", rqstp); | |
7086721f JL |
680 | if (signalled() || kthread_should_stop()) |
681 | return -EINTR; | |
682 | else | |
683 | return -EAGAIN; | |
0f0257ea TT |
684 | } |
685 | } | |
686 | spin_unlock_bh(&pool->sp_lock); | |
687 | ||
688 | len = 0; | |
689 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { | |
690 | dprintk("svc_recv: found XPT_CLOSE\n"); | |
691 | svc_delete_xprt(xprt); | |
692 | } else if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { | |
693 | struct svc_xprt *newxpt; | |
694 | newxpt = xprt->xpt_ops->xpo_accept(xprt); | |
695 | if (newxpt) { | |
696 | /* | |
697 | * We know this module_get will succeed because the | |
698 | * listener holds a reference too | |
699 | */ | |
700 | __module_get(newxpt->xpt_class->xcl_owner); | |
701 | svc_check_conn_limits(xprt->xpt_server); | |
702 | spin_lock_bh(&serv->sv_lock); | |
703 | set_bit(XPT_TEMP, &newxpt->xpt_flags); | |
704 | list_add(&newxpt->xpt_list, &serv->sv_tempsocks); | |
705 | serv->sv_tmpcnt++; | |
706 | if (serv->sv_temptimer.function == NULL) { | |
707 | /* setup timer to age temp transports */ | |
708 | setup_timer(&serv->sv_temptimer, | |
709 | svc_age_temp_xprts, | |
710 | (unsigned long)serv); | |
711 | mod_timer(&serv->sv_temptimer, | |
712 | jiffies + svc_conn_age_period * HZ); | |
713 | } | |
714 | spin_unlock_bh(&serv->sv_lock); | |
715 | svc_xprt_received(newxpt); | |
716 | } | |
717 | svc_xprt_received(xprt); | |
718 | } else { | |
719 | dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", | |
720 | rqstp, pool->sp_id, xprt, | |
721 | atomic_read(&xprt->xpt_ref.refcount)); | |
722 | rqstp->rq_deferred = svc_deferred_dequeue(xprt); | |
723 | if (rqstp->rq_deferred) { | |
724 | svc_xprt_received(xprt); | |
725 | len = svc_deferred_recv(rqstp); | |
726 | } else | |
727 | len = xprt->xpt_ops->xpo_recvfrom(rqstp); | |
728 | dprintk("svc: got len=%d\n", len); | |
729 | } | |
730 | ||
731 | /* No data, incomplete (TCP) read, or accept() */ | |
732 | if (len == 0 || len == -EAGAIN) { | |
733 | rqstp->rq_res.len = 0; | |
734 | svc_xprt_release(rqstp); | |
735 | return -EAGAIN; | |
736 | } | |
737 | clear_bit(XPT_OLD, &xprt->xpt_flags); | |
738 | ||
739 | rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp)); | |
740 | rqstp->rq_chandle.defer = svc_defer; | |
741 | ||
742 | if (serv->sv_stats) | |
743 | serv->sv_stats->netcnt++; | |
744 | return len; | |
745 | } | |
24c3767e | 746 | EXPORT_SYMBOL_GPL(svc_recv); |
0f0257ea TT |
747 | |
748 | /* | |
749 | * Drop request | |
750 | */ | |
751 | void svc_drop(struct svc_rqst *rqstp) | |
752 | { | |
753 | dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); | |
754 | svc_xprt_release(rqstp); | |
755 | } | |
24c3767e | 756 | EXPORT_SYMBOL_GPL(svc_drop); |
0f0257ea TT |
757 | |
758 | /* | |
759 | * Return reply to client. | |
760 | */ | |
761 | int svc_send(struct svc_rqst *rqstp) | |
762 | { | |
763 | struct svc_xprt *xprt; | |
764 | int len; | |
765 | struct xdr_buf *xb; | |
766 | ||
767 | xprt = rqstp->rq_xprt; | |
768 | if (!xprt) | |
769 | return -EFAULT; | |
770 | ||
771 | /* release the receive skb before sending the reply */ | |
772 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); | |
773 | ||
774 | /* calculate over-all length */ | |
775 | xb = &rqstp->rq_res; | |
776 | xb->len = xb->head[0].iov_len + | |
777 | xb->page_len + | |
778 | xb->tail[0].iov_len; | |
779 | ||
780 | /* Grab mutex to serialize outgoing data. */ | |
781 | mutex_lock(&xprt->xpt_mutex); | |
782 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) | |
783 | len = -ENOTCONN; | |
784 | else | |
785 | len = xprt->xpt_ops->xpo_sendto(rqstp); | |
786 | mutex_unlock(&xprt->xpt_mutex); | |
787 | svc_xprt_release(rqstp); | |
788 | ||
789 | if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) | |
790 | return 0; | |
791 | return len; | |
792 | } | |
793 | ||
794 | /* | |
795 | * Timer function to close old temporary transports, using | |
796 | * a mark-and-sweep algorithm. | |
797 | */ | |
798 | static void svc_age_temp_xprts(unsigned long closure) | |
799 | { | |
800 | struct svc_serv *serv = (struct svc_serv *)closure; | |
801 | struct svc_xprt *xprt; | |
802 | struct list_head *le, *next; | |
803 | LIST_HEAD(to_be_aged); | |
804 | ||
805 | dprintk("svc_age_temp_xprts\n"); | |
806 | ||
807 | if (!spin_trylock_bh(&serv->sv_lock)) { | |
808 | /* busy, try again 1 sec later */ | |
809 | dprintk("svc_age_temp_xprts: busy\n"); | |
810 | mod_timer(&serv->sv_temptimer, jiffies + HZ); | |
811 | return; | |
812 | } | |
813 | ||
814 | list_for_each_safe(le, next, &serv->sv_tempsocks) { | |
815 | xprt = list_entry(le, struct svc_xprt, xpt_list); | |
816 | ||
817 | /* First time through, just mark it OLD. Second time | |
818 | * through, close it. */ | |
819 | if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) | |
820 | continue; | |
821 | if (atomic_read(&xprt->xpt_ref.refcount) > 1 | |
822 | || test_bit(XPT_BUSY, &xprt->xpt_flags)) | |
823 | continue; | |
824 | svc_xprt_get(xprt); | |
825 | list_move(le, &to_be_aged); | |
826 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
827 | set_bit(XPT_DETACHED, &xprt->xpt_flags); | |
828 | } | |
829 | spin_unlock_bh(&serv->sv_lock); | |
830 | ||
831 | while (!list_empty(&to_be_aged)) { | |
832 | le = to_be_aged.next; | |
833 | /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */ | |
834 | list_del_init(le); | |
835 | xprt = list_entry(le, struct svc_xprt, xpt_list); | |
836 | ||
837 | dprintk("queuing xprt %p for closing\n", xprt); | |
838 | ||
839 | /* a thread will dequeue and close it soon */ | |
840 | svc_xprt_enqueue(xprt); | |
841 | svc_xprt_put(xprt); | |
842 | } | |
843 | ||
844 | mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); | |
845 | } | |
846 | ||
847 | /* | |
848 | * Remove a dead transport | |
849 | */ | |
850 | void svc_delete_xprt(struct svc_xprt *xprt) | |
851 | { | |
852 | struct svc_serv *serv = xprt->xpt_server; | |
22945e4a TT |
853 | struct svc_deferred_req *dr; |
854 | ||
855 | /* Only do this once */ | |
856 | if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) | |
857 | return; | |
0f0257ea TT |
858 | |
859 | dprintk("svc: svc_delete_xprt(%p)\n", xprt); | |
860 | xprt->xpt_ops->xpo_detach(xprt); | |
861 | ||
862 | spin_lock_bh(&serv->sv_lock); | |
863 | if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags)) | |
864 | list_del_init(&xprt->xpt_list); | |
865 | /* | |
866 | * We used to delete the transport from whichever list | |
867 | * it's sk_xprt.xpt_ready node was on, but we don't actually | |
868 | * need to. This is because the only time we're called | |
869 | * while still attached to a queue, the queue itself | |
870 | * is about to be destroyed (in svc_destroy). | |
871 | */ | |
22945e4a TT |
872 | if (test_bit(XPT_TEMP, &xprt->xpt_flags)) |
873 | serv->sv_tmpcnt--; | |
874 | ||
875 | for (dr = svc_deferred_dequeue(xprt); dr; | |
876 | dr = svc_deferred_dequeue(xprt)) { | |
0f0257ea | 877 | svc_xprt_put(xprt); |
22945e4a | 878 | kfree(dr); |
0f0257ea | 879 | } |
22945e4a TT |
880 | |
881 | svc_xprt_put(xprt); | |
0f0257ea TT |
882 | spin_unlock_bh(&serv->sv_lock); |
883 | } | |
884 | ||
885 | void svc_close_xprt(struct svc_xprt *xprt) | |
886 | { | |
887 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
888 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) | |
889 | /* someone else will have to effect the close */ | |
890 | return; | |
891 | ||
892 | svc_xprt_get(xprt); | |
893 | svc_delete_xprt(xprt); | |
894 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
895 | svc_xprt_put(xprt); | |
896 | } | |
a217813f | 897 | EXPORT_SYMBOL_GPL(svc_close_xprt); |
0f0257ea TT |
898 | |
899 | void svc_close_all(struct list_head *xprt_list) | |
900 | { | |
901 | struct svc_xprt *xprt; | |
902 | struct svc_xprt *tmp; | |
903 | ||
904 | list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) { | |
905 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
906 | if (test_bit(XPT_BUSY, &xprt->xpt_flags)) { | |
907 | /* Waiting to be processed, but no threads left, | |
908 | * So just remove it from the waiting list | |
909 | */ | |
910 | list_del_init(&xprt->xpt_ready); | |
911 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
912 | } | |
913 | svc_close_xprt(xprt); | |
914 | } | |
915 | } | |
916 | ||
917 | /* | |
918 | * Handle defer and revisit of requests | |
919 | */ | |
920 | ||
921 | static void svc_revisit(struct cache_deferred_req *dreq, int too_many) | |
922 | { | |
923 | struct svc_deferred_req *dr = | |
924 | container_of(dreq, struct svc_deferred_req, handle); | |
925 | struct svc_xprt *xprt = dr->xprt; | |
926 | ||
22945e4a TT |
927 | spin_lock(&xprt->xpt_lock); |
928 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
929 | if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { | |
930 | spin_unlock(&xprt->xpt_lock); | |
931 | dprintk("revisit canceled\n"); | |
0f0257ea TT |
932 | svc_xprt_put(xprt); |
933 | kfree(dr); | |
934 | return; | |
935 | } | |
936 | dprintk("revisit queued\n"); | |
937 | dr->xprt = NULL; | |
0f0257ea TT |
938 | list_add(&dr->handle.recent, &xprt->xpt_deferred); |
939 | spin_unlock(&xprt->xpt_lock); | |
0f0257ea TT |
940 | svc_xprt_enqueue(xprt); |
941 | svc_xprt_put(xprt); | |
942 | } | |
943 | ||
260c1d12 TT |
944 | /* |
945 | * Save the request off for later processing. The request buffer looks | |
946 | * like this: | |
947 | * | |
948 | * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> | |
949 | * | |
950 | * This code can only handle requests that consist of an xprt-header | |
951 | * and rpc-header. | |
952 | */ | |
0f0257ea TT |
953 | static struct cache_deferred_req *svc_defer(struct cache_req *req) |
954 | { | |
955 | struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); | |
0f0257ea TT |
956 | struct svc_deferred_req *dr; |
957 | ||
958 | if (rqstp->rq_arg.page_len) | |
959 | return NULL; /* if more than a page, give up FIXME */ | |
960 | if (rqstp->rq_deferred) { | |
961 | dr = rqstp->rq_deferred; | |
962 | rqstp->rq_deferred = NULL; | |
963 | } else { | |
260c1d12 TT |
964 | size_t skip; |
965 | size_t size; | |
0f0257ea | 966 | /* FIXME maybe discard if size too large */ |
260c1d12 | 967 | size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; |
0f0257ea TT |
968 | dr = kmalloc(size, GFP_KERNEL); |
969 | if (dr == NULL) | |
970 | return NULL; | |
971 | ||
972 | dr->handle.owner = rqstp->rq_server; | |
973 | dr->prot = rqstp->rq_prot; | |
974 | memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); | |
975 | dr->addrlen = rqstp->rq_addrlen; | |
976 | dr->daddr = rqstp->rq_daddr; | |
977 | dr->argslen = rqstp->rq_arg.len >> 2; | |
260c1d12 TT |
978 | dr->xprt_hlen = rqstp->rq_xprt_hlen; |
979 | ||
980 | /* back up head to the start of the buffer and copy */ | |
981 | skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; | |
982 | memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, | |
983 | dr->argslen << 2); | |
0f0257ea TT |
984 | } |
985 | svc_xprt_get(rqstp->rq_xprt); | |
986 | dr->xprt = rqstp->rq_xprt; | |
987 | ||
988 | dr->handle.revisit = svc_revisit; | |
989 | return &dr->handle; | |
990 | } | |
991 | ||
992 | /* | |
993 | * recv data from a deferred request into an active one | |
994 | */ | |
995 | static int svc_deferred_recv(struct svc_rqst *rqstp) | |
996 | { | |
997 | struct svc_deferred_req *dr = rqstp->rq_deferred; | |
998 | ||
260c1d12 TT |
999 | /* setup iov_base past transport header */ |
1000 | rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); | |
1001 | /* The iov_len does not include the transport header bytes */ | |
1002 | rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; | |
0f0257ea | 1003 | rqstp->rq_arg.page_len = 0; |
260c1d12 TT |
1004 | /* The rq_arg.len includes the transport header bytes */ |
1005 | rqstp->rq_arg.len = dr->argslen<<2; | |
0f0257ea TT |
1006 | rqstp->rq_prot = dr->prot; |
1007 | memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); | |
1008 | rqstp->rq_addrlen = dr->addrlen; | |
260c1d12 TT |
1009 | /* Save off transport header len in case we get deferred again */ |
1010 | rqstp->rq_xprt_hlen = dr->xprt_hlen; | |
0f0257ea TT |
1011 | rqstp->rq_daddr = dr->daddr; |
1012 | rqstp->rq_respages = rqstp->rq_pages; | |
260c1d12 | 1013 | return (dr->argslen<<2) - dr->xprt_hlen; |
0f0257ea TT |
1014 | } |
1015 | ||
1016 | ||
1017 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) | |
1018 | { | |
1019 | struct svc_deferred_req *dr = NULL; | |
1020 | ||
1021 | if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) | |
1022 | return NULL; | |
1023 | spin_lock(&xprt->xpt_lock); | |
1024 | clear_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
1025 | if (!list_empty(&xprt->xpt_deferred)) { | |
1026 | dr = list_entry(xprt->xpt_deferred.next, | |
1027 | struct svc_deferred_req, | |
1028 | handle.recent); | |
1029 | list_del_init(&dr->handle.recent); | |
1030 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
1031 | } | |
1032 | spin_unlock(&xprt->xpt_lock); | |
1033 | return dr; | |
1034 | } | |
7fcb98d5 TT |
1035 | |
1036 | /* | |
1037 | * Return the transport instance pointer for the endpoint accepting | |
1038 | * connections/peer traffic from the specified transport class, | |
1039 | * address family and port. | |
1040 | * | |
1041 | * Specifying 0 for the address family or port is effectively a | |
1042 | * wild-card, and will result in matching the first transport in the | |
1043 | * service's list that has a matching class name. | |
1044 | */ | |
1045 | struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name, | |
1046 | int af, int port) | |
1047 | { | |
1048 | struct svc_xprt *xprt; | |
1049 | struct svc_xprt *found = NULL; | |
1050 | ||
1051 | /* Sanity check the args */ | |
1052 | if (!serv || !xcl_name) | |
1053 | return found; | |
1054 | ||
1055 | spin_lock_bh(&serv->sv_lock); | |
1056 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { | |
1057 | if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) | |
1058 | continue; | |
1059 | if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) | |
1060 | continue; | |
1061 | if (port && port != svc_xprt_local_port(xprt)) | |
1062 | continue; | |
1063 | found = xprt; | |
a217813f | 1064 | svc_xprt_get(xprt); |
7fcb98d5 TT |
1065 | break; |
1066 | } | |
1067 | spin_unlock_bh(&serv->sv_lock); | |
1068 | return found; | |
1069 | } | |
1070 | EXPORT_SYMBOL_GPL(svc_find_xprt); | |
9571af18 TT |
1071 | |
1072 | /* | |
1073 | * Format a buffer with a list of the active transports. A zero for | |
1074 | * the buflen parameter disables target buffer overflow checking. | |
1075 | */ | |
1076 | int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen) | |
1077 | { | |
1078 | struct svc_xprt *xprt; | |
1079 | char xprt_str[64]; | |
1080 | int totlen = 0; | |
1081 | int len; | |
1082 | ||
1083 | /* Sanity check args */ | |
1084 | if (!serv) | |
1085 | return 0; | |
1086 | ||
1087 | spin_lock_bh(&serv->sv_lock); | |
1088 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { | |
1089 | len = snprintf(xprt_str, sizeof(xprt_str), | |
1090 | "%s %d\n", xprt->xpt_class->xcl_name, | |
1091 | svc_xprt_local_port(xprt)); | |
1092 | /* If the string was truncated, replace with error string */ | |
1093 | if (len >= sizeof(xprt_str)) | |
1094 | strcpy(xprt_str, "name-too-long\n"); | |
1095 | /* Don't overflow buffer */ | |
1096 | len = strlen(xprt_str); | |
1097 | if (buflen && (len + totlen >= buflen)) | |
1098 | break; | |
1099 | strcpy(buf+totlen, xprt_str); | |
1100 | totlen += len; | |
1101 | } | |
1102 | spin_unlock_bh(&serv->sv_lock); | |
1103 | return totlen; | |
1104 | } | |
1105 | EXPORT_SYMBOL_GPL(svc_xprt_names); |