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TOMOYO Linux Cross Reference
Linux/fs/afs/rxrpc.c

Version: ~ [ linux-4.20-rc5 ] ~ [ linux-4.19.6 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.85 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.142 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.166 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.128 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.61 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.31.14 ] ~ [ linux-2.6.30.10 ] ~ [ linux-2.6.29.6 ] ~ [ linux-2.6.28.10 ] ~ [ linux-2.6.27.62 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /* Maintain an RxRPC server socket to do AFS communications through
  2  *
  3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License
  8  * as published by the Free Software Foundation; either version
  9  * 2 of the License, or (at your option) any later version.
 10  */
 11 
 12 #include <linux/slab.h>
 13 #include <linux/sched/signal.h>
 14 
 15 #include <net/sock.h>
 16 #include <net/af_rxrpc.h>
 17 #include "internal.h"
 18 #include "afs_cm.h"
 19 #include "protocol_yfs.h"
 20 
 21 struct workqueue_struct *afs_async_calls;
 22 
 23 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
 24 static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
 25 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
 26 static void afs_process_async_call(struct work_struct *);
 27 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
 28 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
 29 static int afs_deliver_cm_op_id(struct afs_call *);
 30 
 31 /* asynchronous incoming call initial processing */
 32 static const struct afs_call_type afs_RXCMxxxx = {
 33         .name           = "CB.xxxx",
 34         .deliver        = afs_deliver_cm_op_id,
 35 };
 36 
 37 /*
 38  * open an RxRPC socket and bind it to be a server for callback notifications
 39  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
 40  */
 41 int afs_open_socket(struct afs_net *net)
 42 {
 43         struct sockaddr_rxrpc srx;
 44         struct socket *socket;
 45         unsigned int min_level;
 46         int ret;
 47 
 48         _enter("");
 49 
 50         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
 51         if (ret < 0)
 52                 goto error_1;
 53 
 54         socket->sk->sk_allocation = GFP_NOFS;
 55 
 56         /* bind the callback manager's address to make this a server socket */
 57         memset(&srx, 0, sizeof(srx));
 58         srx.srx_family                  = AF_RXRPC;
 59         srx.srx_service                 = CM_SERVICE;
 60         srx.transport_type              = SOCK_DGRAM;
 61         srx.transport_len               = sizeof(srx.transport.sin6);
 62         srx.transport.sin6.sin6_family  = AF_INET6;
 63         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
 64 
 65         min_level = RXRPC_SECURITY_ENCRYPT;
 66         ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
 67                                 (void *)&min_level, sizeof(min_level));
 68         if (ret < 0)
 69                 goto error_2;
 70 
 71         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 72         if (ret == -EADDRINUSE) {
 73                 srx.transport.sin6.sin6_port = 0;
 74                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 75         }
 76         if (ret < 0)
 77                 goto error_2;
 78 
 79         srx.srx_service = YFS_CM_SERVICE;
 80         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 81         if (ret < 0)
 82                 goto error_2;
 83 
 84         /* Ideally, we'd turn on service upgrade here, but we can't because
 85          * OpenAFS is buggy and leaks the userStatus field from packet to
 86          * packet and between FS packets and CB packets - so if we try to do an
 87          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
 88          * it sends back to us.
 89          */
 90 
 91         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
 92                                            afs_rx_discard_new_call);
 93 
 94         ret = kernel_listen(socket, INT_MAX);
 95         if (ret < 0)
 96                 goto error_2;
 97 
 98         net->socket = socket;
 99         afs_charge_preallocation(&net->charge_preallocation_work);
100         _leave(" = 0");
101         return 0;
102 
103 error_2:
104         sock_release(socket);
105 error_1:
106         _leave(" = %d", ret);
107         return ret;
108 }
109 
110 /*
111  * close the RxRPC socket AFS was using
112  */
113 void afs_close_socket(struct afs_net *net)
114 {
115         _enter("");
116 
117         kernel_listen(net->socket, 0);
118         flush_workqueue(afs_async_calls);
119 
120         if (net->spare_incoming_call) {
121                 afs_put_call(net->spare_incoming_call);
122                 net->spare_incoming_call = NULL;
123         }
124 
125         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
126         wait_var_event(&net->nr_outstanding_calls,
127                        !atomic_read(&net->nr_outstanding_calls));
128         _debug("no outstanding calls");
129 
130         kernel_sock_shutdown(net->socket, SHUT_RDWR);
131         flush_workqueue(afs_async_calls);
132         sock_release(net->socket);
133 
134         _debug("dework");
135         _leave("");
136 }
137 
138 /*
139  * Allocate a call.
140  */
141 static struct afs_call *afs_alloc_call(struct afs_net *net,
142                                        const struct afs_call_type *type,
143                                        gfp_t gfp)
144 {
145         struct afs_call *call;
146         int o;
147 
148         call = kzalloc(sizeof(*call), gfp);
149         if (!call)
150                 return NULL;
151 
152         call->type = type;
153         call->net = net;
154         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
155         atomic_set(&call->usage, 1);
156         INIT_WORK(&call->async_work, afs_process_async_call);
157         init_waitqueue_head(&call->waitq);
158         spin_lock_init(&call->state_lock);
159         call->_iter = &call->iter;
160 
161         o = atomic_inc_return(&net->nr_outstanding_calls);
162         trace_afs_call(call, afs_call_trace_alloc, 1, o,
163                        __builtin_return_address(0));
164         return call;
165 }
166 
167 /*
168  * Dispose of a reference on a call.
169  */
170 void afs_put_call(struct afs_call *call)
171 {
172         struct afs_net *net = call->net;
173         int n = atomic_dec_return(&call->usage);
174         int o = atomic_read(&net->nr_outstanding_calls);
175 
176         trace_afs_call(call, afs_call_trace_put, n + 1, o,
177                        __builtin_return_address(0));
178 
179         ASSERTCMP(n, >=, 0);
180         if (n == 0) {
181                 ASSERT(!work_pending(&call->async_work));
182                 ASSERT(call->type->name != NULL);
183 
184                 if (call->rxcall) {
185                         rxrpc_kernel_end_call(net->socket, call->rxcall);
186                         call->rxcall = NULL;
187                 }
188                 if (call->type->destructor)
189                         call->type->destructor(call);
190 
191                 afs_put_server(call->net, call->cm_server);
192                 afs_put_cb_interest(call->net, call->cbi);
193                 afs_put_addrlist(call->alist);
194                 kfree(call->request);
195 
196                 trace_afs_call(call, afs_call_trace_free, 0, o,
197                                __builtin_return_address(0));
198                 kfree(call);
199 
200                 o = atomic_dec_return(&net->nr_outstanding_calls);
201                 if (o == 0)
202                         wake_up_var(&net->nr_outstanding_calls);
203         }
204 }
205 
206 /*
207  * Queue the call for actual work.
208  */
209 static void afs_queue_call_work(struct afs_call *call)
210 {
211         if (call->type->work) {
212                 int u = atomic_inc_return(&call->usage);
213 
214                 trace_afs_call(call, afs_call_trace_work, u,
215                                atomic_read(&call->net->nr_outstanding_calls),
216                                __builtin_return_address(0));
217 
218                 INIT_WORK(&call->work, call->type->work);
219 
220                 if (!queue_work(afs_wq, &call->work))
221                         afs_put_call(call);
222         }
223 }
224 
225 /*
226  * allocate a call with flat request and reply buffers
227  */
228 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
229                                      const struct afs_call_type *type,
230                                      size_t request_size, size_t reply_max)
231 {
232         struct afs_call *call;
233 
234         call = afs_alloc_call(net, type, GFP_NOFS);
235         if (!call)
236                 goto nomem_call;
237 
238         if (request_size) {
239                 call->request_size = request_size;
240                 call->request = kmalloc(request_size, GFP_NOFS);
241                 if (!call->request)
242                         goto nomem_free;
243         }
244 
245         if (reply_max) {
246                 call->reply_max = reply_max;
247                 call->buffer = kmalloc(reply_max, GFP_NOFS);
248                 if (!call->buffer)
249                         goto nomem_free;
250         }
251 
252         afs_extract_to_buf(call, call->reply_max);
253         call->operation_ID = type->op;
254         init_waitqueue_head(&call->waitq);
255         return call;
256 
257 nomem_free:
258         afs_put_call(call);
259 nomem_call:
260         return NULL;
261 }
262 
263 /*
264  * clean up a call with flat buffer
265  */
266 void afs_flat_call_destructor(struct afs_call *call)
267 {
268         _enter("");
269 
270         kfree(call->request);
271         call->request = NULL;
272         kfree(call->buffer);
273         call->buffer = NULL;
274 }
275 
276 #define AFS_BVEC_MAX 8
277 
278 /*
279  * Load the given bvec with the next few pages.
280  */
281 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
282                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
283                           unsigned offset)
284 {
285         struct page *pages[AFS_BVEC_MAX];
286         unsigned int nr, n, i, to, bytes = 0;
287 
288         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
289         n = find_get_pages_contig(call->mapping, first, nr, pages);
290         ASSERTCMP(n, ==, nr);
291 
292         msg->msg_flags |= MSG_MORE;
293         for (i = 0; i < nr; i++) {
294                 to = PAGE_SIZE;
295                 if (first + i >= last) {
296                         to = call->last_to;
297                         msg->msg_flags &= ~MSG_MORE;
298                 }
299                 bv[i].bv_page = pages[i];
300                 bv[i].bv_len = to - offset;
301                 bv[i].bv_offset = offset;
302                 bytes += to - offset;
303                 offset = 0;
304         }
305 
306         iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
307 }
308 
309 /*
310  * Advance the AFS call state when the RxRPC call ends the transmit phase.
311  */
312 static void afs_notify_end_request_tx(struct sock *sock,
313                                       struct rxrpc_call *rxcall,
314                                       unsigned long call_user_ID)
315 {
316         struct afs_call *call = (struct afs_call *)call_user_ID;
317 
318         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
319 }
320 
321 /*
322  * attach the data from a bunch of pages on an inode to a call
323  */
324 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
325 {
326         struct bio_vec bv[AFS_BVEC_MAX];
327         unsigned int bytes, nr, loop, offset;
328         pgoff_t first = call->first, last = call->last;
329         int ret;
330 
331         offset = call->first_offset;
332         call->first_offset = 0;
333 
334         do {
335                 afs_load_bvec(call, msg, bv, first, last, offset);
336                 trace_afs_send_pages(call, msg, first, last, offset);
337 
338                 offset = 0;
339                 bytes = msg->msg_iter.count;
340                 nr = msg->msg_iter.nr_segs;
341 
342                 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
343                                              bytes, afs_notify_end_request_tx);
344                 for (loop = 0; loop < nr; loop++)
345                         put_page(bv[loop].bv_page);
346                 if (ret < 0)
347                         break;
348 
349                 first += nr;
350         } while (first <= last);
351 
352         trace_afs_sent_pages(call, call->first, last, first, ret);
353         return ret;
354 }
355 
356 /*
357  * initiate a call
358  */
359 long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
360                    gfp_t gfp, bool async)
361 {
362         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
363         struct rxrpc_call *rxcall;
364         struct msghdr msg;
365         struct kvec iov[1];
366         s64 tx_total_len;
367         int ret;
368 
369         _enter(",{%pISp},", &srx->transport);
370 
371         ASSERT(call->type != NULL);
372         ASSERT(call->type->name != NULL);
373 
374         _debug("____MAKE %p{%s,%x} [%d]____",
375                call, call->type->name, key_serial(call->key),
376                atomic_read(&call->net->nr_outstanding_calls));
377 
378         call->async = async;
379         call->addr_ix = ac->index;
380         call->alist = afs_get_addrlist(ac->alist);
381 
382         /* Work out the length we're going to transmit.  This is awkward for
383          * calls such as FS.StoreData where there's an extra injection of data
384          * after the initial fixed part.
385          */
386         tx_total_len = call->request_size;
387         if (call->send_pages) {
388                 if (call->last == call->first) {
389                         tx_total_len += call->last_to - call->first_offset;
390                 } else {
391                         /* It looks mathematically like you should be able to
392                          * combine the following lines with the ones above, but
393                          * unsigned arithmetic is fun when it wraps...
394                          */
395                         tx_total_len += PAGE_SIZE - call->first_offset;
396                         tx_total_len += call->last_to;
397                         tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
398                 }
399         }
400 
401         /* create a call */
402         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
403                                          (unsigned long)call,
404                                          tx_total_len, gfp,
405                                          (async ?
406                                           afs_wake_up_async_call :
407                                           afs_wake_up_call_waiter),
408                                          call->upgrade,
409                                          call->debug_id);
410         if (IS_ERR(rxcall)) {
411                 ret = PTR_ERR(rxcall);
412                 call->error = ret;
413                 goto error_kill_call;
414         }
415 
416         call->rxcall = rxcall;
417 
418         /* send the request */
419         iov[0].iov_base = call->request;
420         iov[0].iov_len  = call->request_size;
421 
422         msg.msg_name            = NULL;
423         msg.msg_namelen         = 0;
424         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
425         msg.msg_control         = NULL;
426         msg.msg_controllen      = 0;
427         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
428 
429         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
430                                      &msg, call->request_size,
431                                      afs_notify_end_request_tx);
432         if (ret < 0)
433                 goto error_do_abort;
434 
435         if (call->send_pages) {
436                 ret = afs_send_pages(call, &msg);
437                 if (ret < 0)
438                         goto error_do_abort;
439         }
440 
441         /* at this point, an async call may no longer exist as it may have
442          * already completed */
443         if (call->async)
444                 return -EINPROGRESS;
445 
446         return afs_wait_for_call_to_complete(call, ac);
447 
448 error_do_abort:
449         call->state = AFS_CALL_COMPLETE;
450         if (ret != -ECONNABORTED) {
451                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
452                                         RX_USER_ABORT, ret, "KSD");
453         } else {
454                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
455                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
456                                        &msg.msg_iter, false,
457                                        &call->abort_code, &call->service_id);
458                 ac->abort_code = call->abort_code;
459                 ac->responded = true;
460         }
461         call->error = ret;
462         trace_afs_call_done(call);
463 error_kill_call:
464         if (call->type->done)
465                 call->type->done(call);
466         afs_put_call(call);
467         ac->error = ret;
468         _leave(" = %d", ret);
469         return ret;
470 }
471 
472 /*
473  * deliver messages to a call
474  */
475 static void afs_deliver_to_call(struct afs_call *call)
476 {
477         enum afs_call_state state;
478         u32 abort_code, remote_abort = 0;
479         int ret;
480 
481         _enter("%s", call->type->name);
482 
483         while (state = READ_ONCE(call->state),
484                state == AFS_CALL_CL_AWAIT_REPLY ||
485                state == AFS_CALL_SV_AWAIT_OP_ID ||
486                state == AFS_CALL_SV_AWAIT_REQUEST ||
487                state == AFS_CALL_SV_AWAIT_ACK
488                ) {
489                 if (state == AFS_CALL_SV_AWAIT_ACK) {
490                         iov_iter_kvec(&call->iter, READ, NULL, 0, 0);
491                         ret = rxrpc_kernel_recv_data(call->net->socket,
492                                                      call->rxcall, &call->iter,
493                                                      false, &remote_abort,
494                                                      &call->service_id);
495                         trace_afs_receive_data(call, &call->iter, false, ret);
496 
497                         if (ret == -EINPROGRESS || ret == -EAGAIN)
498                                 return;
499                         if (ret < 0 || ret == 1) {
500                                 if (ret == 1)
501                                         ret = 0;
502                                 goto call_complete;
503                         }
504                         return;
505                 }
506 
507                 if (call->want_reply_time &&
508                     rxrpc_kernel_get_reply_time(call->net->socket,
509                                                 call->rxcall,
510                                                 &call->reply_time))
511                         call->want_reply_time = false;
512 
513                 ret = call->type->deliver(call);
514                 state = READ_ONCE(call->state);
515                 switch (ret) {
516                 case 0:
517                         afs_queue_call_work(call);
518                         if (state == AFS_CALL_CL_PROC_REPLY) {
519                                 if (call->cbi)
520                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
521                                                 &call->cbi->server->flags);
522                                 goto call_complete;
523                         }
524                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
525                         goto done;
526                 case -EINPROGRESS:
527                 case -EAGAIN:
528                         goto out;
529                 case -ECONNABORTED:
530                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
531                         goto done;
532                 case -ENOTSUPP:
533                         abort_code = RXGEN_OPCODE;
534                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
535                                                 abort_code, ret, "KIV");
536                         goto local_abort;
537                 case -EIO:
538                         pr_err("kAFS: Call %u in bad state %u\n",
539                                call->debug_id, state);
540                         /* Fall through */
541                 case -ENODATA:
542                 case -EBADMSG:
543                 case -EMSGSIZE:
544                 default:
545                         abort_code = RXGEN_CC_UNMARSHAL;
546                         if (state != AFS_CALL_CL_AWAIT_REPLY)
547                                 abort_code = RXGEN_SS_UNMARSHAL;
548                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
549                                                 abort_code, ret, "KUM");
550                         goto local_abort;
551                 }
552         }
553 
554 done:
555         if (call->type->done)
556                 call->type->done(call);
557         if (state == AFS_CALL_COMPLETE && call->incoming)
558                 afs_put_call(call);
559 out:
560         _leave("");
561         return;
562 
563 local_abort:
564         abort_code = 0;
565 call_complete:
566         afs_set_call_complete(call, ret, remote_abort);
567         state = AFS_CALL_COMPLETE;
568         goto done;
569 }
570 
571 /*
572  * wait synchronously for a call to complete
573  */
574 static long afs_wait_for_call_to_complete(struct afs_call *call,
575                                           struct afs_addr_cursor *ac)
576 {
577         signed long rtt2, timeout;
578         long ret;
579         bool stalled = false;
580         u64 rtt;
581         u32 life, last_life;
582 
583         DECLARE_WAITQUEUE(myself, current);
584 
585         _enter("");
586 
587         rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
588         rtt2 = nsecs_to_jiffies64(rtt) * 2;
589         if (rtt2 < 2)
590                 rtt2 = 2;
591 
592         timeout = rtt2;
593         last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
594 
595         add_wait_queue(&call->waitq, &myself);
596         for (;;) {
597                 set_current_state(TASK_UNINTERRUPTIBLE);
598 
599                 /* deliver any messages that are in the queue */
600                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
601                     call->need_attention) {
602                         call->need_attention = false;
603                         __set_current_state(TASK_RUNNING);
604                         afs_deliver_to_call(call);
605                         continue;
606                 }
607 
608                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
609                         break;
610 
611                 life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
612                 if (timeout == 0 &&
613                     life == last_life && signal_pending(current)) {
614                         if (stalled)
615                                 break;
616                         __set_current_state(TASK_RUNNING);
617                         rxrpc_kernel_probe_life(call->net->socket, call->rxcall);
618                         timeout = rtt2;
619                         stalled = true;
620                         continue;
621                 }
622 
623                 if (life != last_life) {
624                         timeout = rtt2;
625                         last_life = life;
626                         stalled = false;
627                 }
628 
629                 timeout = schedule_timeout(timeout);
630         }
631 
632         remove_wait_queue(&call->waitq, &myself);
633         __set_current_state(TASK_RUNNING);
634 
635         /* Kill off the call if it's still live. */
636         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
637                 _debug("call interrupted");
638                 if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
639                                             RX_USER_ABORT, -EINTR, "KWI"))
640                         afs_set_call_complete(call, -EINTR, 0);
641         }
642 
643         spin_lock_bh(&call->state_lock);
644         ac->abort_code = call->abort_code;
645         ac->error = call->error;
646         spin_unlock_bh(&call->state_lock);
647 
648         ret = ac->error;
649         switch (ret) {
650         case 0:
651                 if (call->ret_reply0) {
652                         ret = (long)call->reply[0];
653                         call->reply[0] = NULL;
654                 }
655                 /* Fall through */
656         case -ECONNABORTED:
657                 ac->responded = true;
658                 break;
659         }
660 
661         _debug("call complete");
662         afs_put_call(call);
663         _leave(" = %p", (void *)ret);
664         return ret;
665 }
666 
667 /*
668  * wake up a waiting call
669  */
670 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
671                                     unsigned long call_user_ID)
672 {
673         struct afs_call *call = (struct afs_call *)call_user_ID;
674 
675         call->need_attention = true;
676         wake_up(&call->waitq);
677 }
678 
679 /*
680  * wake up an asynchronous call
681  */
682 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
683                                    unsigned long call_user_ID)
684 {
685         struct afs_call *call = (struct afs_call *)call_user_ID;
686         int u;
687 
688         trace_afs_notify_call(rxcall, call);
689         call->need_attention = true;
690 
691         u = atomic_fetch_add_unless(&call->usage, 1, 0);
692         if (u != 0) {
693                 trace_afs_call(call, afs_call_trace_wake, u,
694                                atomic_read(&call->net->nr_outstanding_calls),
695                                __builtin_return_address(0));
696 
697                 if (!queue_work(afs_async_calls, &call->async_work))
698                         afs_put_call(call);
699         }
700 }
701 
702 /*
703  * Delete an asynchronous call.  The work item carries a ref to the call struct
704  * that we need to release.
705  */
706 static void afs_delete_async_call(struct work_struct *work)
707 {
708         struct afs_call *call = container_of(work, struct afs_call, async_work);
709 
710         _enter("");
711 
712         afs_put_call(call);
713 
714         _leave("");
715 }
716 
717 /*
718  * Perform I/O processing on an asynchronous call.  The work item carries a ref
719  * to the call struct that we either need to release or to pass on.
720  */
721 static void afs_process_async_call(struct work_struct *work)
722 {
723         struct afs_call *call = container_of(work, struct afs_call, async_work);
724 
725         _enter("");
726 
727         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
728                 call->need_attention = false;
729                 afs_deliver_to_call(call);
730         }
731 
732         if (call->state == AFS_CALL_COMPLETE) {
733                 /* We have two refs to release - one from the alloc and one
734                  * queued with the work item - and we can't just deallocate the
735                  * call because the work item may be queued again.
736                  */
737                 call->async_work.func = afs_delete_async_call;
738                 if (!queue_work(afs_async_calls, &call->async_work))
739                         afs_put_call(call);
740         }
741 
742         afs_put_call(call);
743         _leave("");
744 }
745 
746 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
747 {
748         struct afs_call *call = (struct afs_call *)user_call_ID;
749 
750         call->rxcall = rxcall;
751 }
752 
753 /*
754  * Charge the incoming call preallocation.
755  */
756 void afs_charge_preallocation(struct work_struct *work)
757 {
758         struct afs_net *net =
759                 container_of(work, struct afs_net, charge_preallocation_work);
760         struct afs_call *call = net->spare_incoming_call;
761 
762         for (;;) {
763                 if (!call) {
764                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
765                         if (!call)
766                                 break;
767 
768                         call->async = true;
769                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
770                         init_waitqueue_head(&call->waitq);
771                         afs_extract_to_tmp(call);
772                 }
773 
774                 if (rxrpc_kernel_charge_accept(net->socket,
775                                                afs_wake_up_async_call,
776                                                afs_rx_attach,
777                                                (unsigned long)call,
778                                                GFP_KERNEL,
779                                                call->debug_id) < 0)
780                         break;
781                 call = NULL;
782         }
783         net->spare_incoming_call = call;
784 }
785 
786 /*
787  * Discard a preallocated call when a socket is shut down.
788  */
789 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
790                                     unsigned long user_call_ID)
791 {
792         struct afs_call *call = (struct afs_call *)user_call_ID;
793 
794         call->rxcall = NULL;
795         afs_put_call(call);
796 }
797 
798 /*
799  * Notification of an incoming call.
800  */
801 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
802                             unsigned long user_call_ID)
803 {
804         struct afs_net *net = afs_sock2net(sk);
805 
806         queue_work(afs_wq, &net->charge_preallocation_work);
807 }
808 
809 /*
810  * Grab the operation ID from an incoming cache manager call.  The socket
811  * buffer is discarded on error or if we don't yet have sufficient data.
812  */
813 static int afs_deliver_cm_op_id(struct afs_call *call)
814 {
815         int ret;
816 
817         _enter("{%zu}", iov_iter_count(call->_iter));
818 
819         /* the operation ID forms the first four bytes of the request data */
820         ret = afs_extract_data(call, true);
821         if (ret < 0)
822                 return ret;
823 
824         call->operation_ID = ntohl(call->tmp);
825         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
826 
827         /* ask the cache manager to route the call (it'll change the call type
828          * if successful) */
829         if (!afs_cm_incoming_call(call))
830                 return -ENOTSUPP;
831 
832         trace_afs_cb_call(call);
833 
834         /* pass responsibility for the remainer of this message off to the
835          * cache manager op */
836         return call->type->deliver(call);
837 }
838 
839 /*
840  * Advance the AFS call state when an RxRPC service call ends the transmit
841  * phase.
842  */
843 static void afs_notify_end_reply_tx(struct sock *sock,
844                                     struct rxrpc_call *rxcall,
845                                     unsigned long call_user_ID)
846 {
847         struct afs_call *call = (struct afs_call *)call_user_ID;
848 
849         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
850 }
851 
852 /*
853  * send an empty reply
854  */
855 void afs_send_empty_reply(struct afs_call *call)
856 {
857         struct afs_net *net = call->net;
858         struct msghdr msg;
859 
860         _enter("");
861 
862         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
863 
864         msg.msg_name            = NULL;
865         msg.msg_namelen         = 0;
866         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
867         msg.msg_control         = NULL;
868         msg.msg_controllen      = 0;
869         msg.msg_flags           = 0;
870 
871         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
872                                        afs_notify_end_reply_tx)) {
873         case 0:
874                 _leave(" [replied]");
875                 return;
876 
877         case -ENOMEM:
878                 _debug("oom");
879                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
880                                         RX_USER_ABORT, -ENOMEM, "KOO");
881         default:
882                 _leave(" [error]");
883                 return;
884         }
885 }
886 
887 /*
888  * send a simple reply
889  */
890 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
891 {
892         struct afs_net *net = call->net;
893         struct msghdr msg;
894         struct kvec iov[1];
895         int n;
896 
897         _enter("");
898 
899         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
900 
901         iov[0].iov_base         = (void *) buf;
902         iov[0].iov_len          = len;
903         msg.msg_name            = NULL;
904         msg.msg_namelen         = 0;
905         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
906         msg.msg_control         = NULL;
907         msg.msg_controllen      = 0;
908         msg.msg_flags           = 0;
909 
910         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
911                                    afs_notify_end_reply_tx);
912         if (n >= 0) {
913                 /* Success */
914                 _leave(" [replied]");
915                 return;
916         }
917 
918         if (n == -ENOMEM) {
919                 _debug("oom");
920                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
921                                         RX_USER_ABORT, -ENOMEM, "KOO");
922         }
923         _leave(" [error]");
924 }
925 
926 /*
927  * Extract a piece of data from the received data socket buffers.
928  */
929 int afs_extract_data(struct afs_call *call, bool want_more)
930 {
931         struct afs_net *net = call->net;
932         struct iov_iter *iter = call->_iter;
933         enum afs_call_state state;
934         u32 remote_abort = 0;
935         int ret;
936 
937         _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
938 
939         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
940                                      want_more, &remote_abort,
941                                      &call->service_id);
942         if (ret == 0 || ret == -EAGAIN)
943                 return ret;
944 
945         state = READ_ONCE(call->state);
946         if (ret == 1) {
947                 switch (state) {
948                 case AFS_CALL_CL_AWAIT_REPLY:
949                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
950                         break;
951                 case AFS_CALL_SV_AWAIT_REQUEST:
952                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
953                         break;
954                 case AFS_CALL_COMPLETE:
955                         kdebug("prem complete %d", call->error);
956                         return afs_io_error(call, afs_io_error_extract);
957                 default:
958                         break;
959                 }
960                 return 0;
961         }
962 
963         afs_set_call_complete(call, ret, remote_abort);
964         return ret;
965 }
966 
967 /*
968  * Log protocol error production.
969  */
970 noinline int afs_protocol_error(struct afs_call *call, int error,
971                                 enum afs_eproto_cause cause)
972 {
973         trace_afs_protocol_error(call, error, cause);
974         return error;
975 }
976 

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