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

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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_delete_async_call(struct work_struct *);
 27 static void afs_process_async_call(struct work_struct *);
 28 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
 29 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
 30 static int afs_deliver_cm_op_id(struct afs_call *);
 31 
 32 /* asynchronous incoming call initial processing */
 33 static const struct afs_call_type afs_RXCMxxxx = {
 34         .name           = "CB.xxxx",
 35         .deliver        = afs_deliver_cm_op_id,
 36 };
 37 
 38 /*
 39  * open an RxRPC socket and bind it to be a server for callback notifications
 40  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
 41  */
 42 int afs_open_socket(struct afs_net *net)
 43 {
 44         struct sockaddr_rxrpc srx;
 45         struct socket *socket;
 46         unsigned int min_level;
 47         int ret;
 48 
 49         _enter("");
 50 
 51         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
 52         if (ret < 0)
 53                 goto error_1;
 54 
 55         socket->sk->sk_allocation = GFP_NOFS;
 56 
 57         /* bind the callback manager's address to make this a server socket */
 58         memset(&srx, 0, sizeof(srx));
 59         srx.srx_family                  = AF_RXRPC;
 60         srx.srx_service                 = CM_SERVICE;
 61         srx.transport_type              = SOCK_DGRAM;
 62         srx.transport_len               = sizeof(srx.transport.sin6);
 63         srx.transport.sin6.sin6_family  = AF_INET6;
 64         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
 65 
 66         min_level = RXRPC_SECURITY_ENCRYPT;
 67         ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
 68                                 (void *)&min_level, sizeof(min_level));
 69         if (ret < 0)
 70                 goto error_2;
 71 
 72         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 73         if (ret == -EADDRINUSE) {
 74                 srx.transport.sin6.sin6_port = 0;
 75                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 76         }
 77         if (ret < 0)
 78                 goto error_2;
 79 
 80         srx.srx_service = YFS_CM_SERVICE;
 81         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 82         if (ret < 0)
 83                 goto error_2;
 84 
 85         /* Ideally, we'd turn on service upgrade here, but we can't because
 86          * OpenAFS is buggy and leaks the userStatus field from packet to
 87          * packet and between FS packets and CB packets - so if we try to do an
 88          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
 89          * it sends back to us.
 90          */
 91 
 92         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
 93                                            afs_rx_discard_new_call);
 94 
 95         ret = kernel_listen(socket, INT_MAX);
 96         if (ret < 0)
 97                 goto error_2;
 98 
 99         net->socket = socket;
100         afs_charge_preallocation(&net->charge_preallocation_work);
101         _leave(" = 0");
102         return 0;
103 
104 error_2:
105         sock_release(socket);
106 error_1:
107         _leave(" = %d", ret);
108         return ret;
109 }
110 
111 /*
112  * close the RxRPC socket AFS was using
113  */
114 void afs_close_socket(struct afs_net *net)
115 {
116         _enter("");
117 
118         kernel_listen(net->socket, 0);
119         flush_workqueue(afs_async_calls);
120 
121         if (net->spare_incoming_call) {
122                 afs_put_call(net->spare_incoming_call);
123                 net->spare_incoming_call = NULL;
124         }
125 
126         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
127         wait_var_event(&net->nr_outstanding_calls,
128                        !atomic_read(&net->nr_outstanding_calls));
129         _debug("no outstanding calls");
130 
131         kernel_sock_shutdown(net->socket, SHUT_RDWR);
132         flush_workqueue(afs_async_calls);
133         sock_release(net->socket);
134 
135         _debug("dework");
136         _leave("");
137 }
138 
139 /*
140  * Allocate a call.
141  */
142 static struct afs_call *afs_alloc_call(struct afs_net *net,
143                                        const struct afs_call_type *type,
144                                        gfp_t gfp)
145 {
146         struct afs_call *call;
147         int o;
148 
149         call = kzalloc(sizeof(*call), gfp);
150         if (!call)
151                 return NULL;
152 
153         call->type = type;
154         call->net = net;
155         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
156         atomic_set(&call->usage, 1);
157         INIT_WORK(&call->async_work, afs_process_async_call);
158         init_waitqueue_head(&call->waitq);
159         spin_lock_init(&call->state_lock);
160         call->_iter = &call->iter;
161 
162         o = atomic_inc_return(&net->nr_outstanding_calls);
163         trace_afs_call(call, afs_call_trace_alloc, 1, o,
164                        __builtin_return_address(0));
165         return call;
166 }
167 
168 /*
169  * Dispose of a reference on a call.
170  */
171 void afs_put_call(struct afs_call *call)
172 {
173         struct afs_net *net = call->net;
174         int n = atomic_dec_return(&call->usage);
175         int o = atomic_read(&net->nr_outstanding_calls);
176 
177         trace_afs_call(call, afs_call_trace_put, n + 1, o,
178                        __builtin_return_address(0));
179 
180         ASSERTCMP(n, >=, 0);
181         if (n == 0) {
182                 ASSERT(!work_pending(&call->async_work));
183                 ASSERT(call->type->name != NULL);
184 
185                 if (call->rxcall) {
186                         rxrpc_kernel_end_call(net->socket, call->rxcall);
187                         call->rxcall = NULL;
188                 }
189                 if (call->type->destructor)
190                         call->type->destructor(call);
191 
192                 afs_put_server(call->net, call->cm_server);
193                 afs_put_cb_interest(call->net, call->cbi);
194                 afs_put_addrlist(call->alist);
195                 kfree(call->request);
196 
197                 trace_afs_call(call, afs_call_trace_free, 0, o,
198                                __builtin_return_address(0));
199                 kfree(call);
200 
201                 o = atomic_dec_return(&net->nr_outstanding_calls);
202                 if (o == 0)
203                         wake_up_var(&net->nr_outstanding_calls);
204         }
205 }
206 
207 static struct afs_call *afs_get_call(struct afs_call *call,
208                                      enum afs_call_trace why)
209 {
210         int u = atomic_inc_return(&call->usage);
211 
212         trace_afs_call(call, why, u,
213                        atomic_read(&call->net->nr_outstanding_calls),
214                        __builtin_return_address(0));
215         return call;
216 }
217 
218 /*
219  * Queue the call for actual work.
220  */
221 static void afs_queue_call_work(struct afs_call *call)
222 {
223         if (call->type->work) {
224                 INIT_WORK(&call->work, call->type->work);
225 
226                 afs_get_call(call, afs_call_trace_work);
227                 if (!queue_work(afs_wq, &call->work))
228                         afs_put_call(call);
229         }
230 }
231 
232 /*
233  * allocate a call with flat request and reply buffers
234  */
235 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
236                                      const struct afs_call_type *type,
237                                      size_t request_size, size_t reply_max)
238 {
239         struct afs_call *call;
240 
241         call = afs_alloc_call(net, type, GFP_NOFS);
242         if (!call)
243                 goto nomem_call;
244 
245         if (request_size) {
246                 call->request_size = request_size;
247                 call->request = kmalloc(request_size, GFP_NOFS);
248                 if (!call->request)
249                         goto nomem_free;
250         }
251 
252         if (reply_max) {
253                 call->reply_max = reply_max;
254                 call->buffer = kmalloc(reply_max, GFP_NOFS);
255                 if (!call->buffer)
256                         goto nomem_free;
257         }
258 
259         afs_extract_to_buf(call, call->reply_max);
260         call->operation_ID = type->op;
261         init_waitqueue_head(&call->waitq);
262         return call;
263 
264 nomem_free:
265         afs_put_call(call);
266 nomem_call:
267         return NULL;
268 }
269 
270 /*
271  * clean up a call with flat buffer
272  */
273 void afs_flat_call_destructor(struct afs_call *call)
274 {
275         _enter("");
276 
277         kfree(call->request);
278         call->request = NULL;
279         kfree(call->buffer);
280         call->buffer = NULL;
281 }
282 
283 #define AFS_BVEC_MAX 8
284 
285 /*
286  * Load the given bvec with the next few pages.
287  */
288 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
289                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
290                           unsigned offset)
291 {
292         struct page *pages[AFS_BVEC_MAX];
293         unsigned int nr, n, i, to, bytes = 0;
294 
295         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
296         n = find_get_pages_contig(call->mapping, first, nr, pages);
297         ASSERTCMP(n, ==, nr);
298 
299         msg->msg_flags |= MSG_MORE;
300         for (i = 0; i < nr; i++) {
301                 to = PAGE_SIZE;
302                 if (first + i >= last) {
303                         to = call->last_to;
304                         msg->msg_flags &= ~MSG_MORE;
305                 }
306                 bv[i].bv_page = pages[i];
307                 bv[i].bv_len = to - offset;
308                 bv[i].bv_offset = offset;
309                 bytes += to - offset;
310                 offset = 0;
311         }
312 
313         iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
314 }
315 
316 /*
317  * Advance the AFS call state when the RxRPC call ends the transmit phase.
318  */
319 static void afs_notify_end_request_tx(struct sock *sock,
320                                       struct rxrpc_call *rxcall,
321                                       unsigned long call_user_ID)
322 {
323         struct afs_call *call = (struct afs_call *)call_user_ID;
324 
325         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
326 }
327 
328 /*
329  * attach the data from a bunch of pages on an inode to a call
330  */
331 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
332 {
333         struct bio_vec bv[AFS_BVEC_MAX];
334         unsigned int bytes, nr, loop, offset;
335         pgoff_t first = call->first, last = call->last;
336         int ret;
337 
338         offset = call->first_offset;
339         call->first_offset = 0;
340 
341         do {
342                 afs_load_bvec(call, msg, bv, first, last, offset);
343                 trace_afs_send_pages(call, msg, first, last, offset);
344 
345                 offset = 0;
346                 bytes = msg->msg_iter.count;
347                 nr = msg->msg_iter.nr_segs;
348 
349                 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
350                                              bytes, afs_notify_end_request_tx);
351                 for (loop = 0; loop < nr; loop++)
352                         put_page(bv[loop].bv_page);
353                 if (ret < 0)
354                         break;
355 
356                 first += nr;
357         } while (first <= last);
358 
359         trace_afs_sent_pages(call, call->first, last, first, ret);
360         return ret;
361 }
362 
363 /*
364  * initiate a call
365  */
366 long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
367                    gfp_t gfp, bool async)
368 {
369         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
370         struct rxrpc_call *rxcall;
371         struct msghdr msg;
372         struct kvec iov[1];
373         s64 tx_total_len;
374         int ret;
375 
376         _enter(",{%pISp},", &srx->transport);
377 
378         ASSERT(call->type != NULL);
379         ASSERT(call->type->name != NULL);
380 
381         _debug("____MAKE %p{%s,%x} [%d]____",
382                call, call->type->name, key_serial(call->key),
383                atomic_read(&call->net->nr_outstanding_calls));
384 
385         call->async = async;
386         call->addr_ix = ac->index;
387         call->alist = afs_get_addrlist(ac->alist);
388 
389         /* Work out the length we're going to transmit.  This is awkward for
390          * calls such as FS.StoreData where there's an extra injection of data
391          * after the initial fixed part.
392          */
393         tx_total_len = call->request_size;
394         if (call->send_pages) {
395                 if (call->last == call->first) {
396                         tx_total_len += call->last_to - call->first_offset;
397                 } else {
398                         /* It looks mathematically like you should be able to
399                          * combine the following lines with the ones above, but
400                          * unsigned arithmetic is fun when it wraps...
401                          */
402                         tx_total_len += PAGE_SIZE - call->first_offset;
403                         tx_total_len += call->last_to;
404                         tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
405                 }
406         }
407 
408         /* If the call is going to be asynchronous, we need an extra ref for
409          * the call to hold itself so the caller need not hang on to its ref.
410          */
411         if (call->async)
412                 afs_get_call(call, afs_call_trace_get);
413 
414         /* create a call */
415         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
416                                          (unsigned long)call,
417                                          tx_total_len, gfp,
418                                          (async ?
419                                           afs_wake_up_async_call :
420                                           afs_wake_up_call_waiter),
421                                          call->upgrade,
422                                          call->debug_id);
423         if (IS_ERR(rxcall)) {
424                 ret = PTR_ERR(rxcall);
425                 call->error = ret;
426                 goto error_kill_call;
427         }
428 
429         call->rxcall = rxcall;
430 
431         /* send the request */
432         iov[0].iov_base = call->request;
433         iov[0].iov_len  = call->request_size;
434 
435         msg.msg_name            = NULL;
436         msg.msg_namelen         = 0;
437         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
438         msg.msg_control         = NULL;
439         msg.msg_controllen      = 0;
440         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
441 
442         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
443                                      &msg, call->request_size,
444                                      afs_notify_end_request_tx);
445         if (ret < 0)
446                 goto error_do_abort;
447 
448         if (call->send_pages) {
449                 ret = afs_send_pages(call, &msg);
450                 if (ret < 0)
451                         goto error_do_abort;
452         }
453 
454         /* Note that at this point, we may have received the reply or an abort
455          * - and an asynchronous call may already have completed.
456          */
457         if (call->async) {
458                 afs_put_call(call);
459                 return -EINPROGRESS;
460         }
461 
462         return afs_wait_for_call_to_complete(call, ac);
463 
464 error_do_abort:
465         if (ret != -ECONNABORTED) {
466                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
467                                         RX_USER_ABORT, ret, "KSD");
468         } else {
469                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
470                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
471                                        &msg.msg_iter, false,
472                                        &call->abort_code, &call->service_id);
473                 ac->abort_code = call->abort_code;
474                 ac->responded = true;
475         }
476         call->error = ret;
477         trace_afs_call_done(call);
478 error_kill_call:
479         if (call->type->done)
480                 call->type->done(call);
481 
482         /* We need to dispose of the extra ref we grabbed for an async call.
483          * The call, however, might be queued on afs_async_calls and we need to
484          * make sure we don't get any more notifications that might requeue it.
485          */
486         if (call->rxcall) {
487                 rxrpc_kernel_end_call(call->net->socket, call->rxcall);
488                 call->rxcall = NULL;
489         }
490         if (call->async) {
491                 if (cancel_work_sync(&call->async_work))
492                         afs_put_call(call);
493                 afs_put_call(call);
494         }
495 
496         ac->error = ret;
497         call->state = AFS_CALL_COMPLETE;
498         afs_put_call(call);
499         _leave(" = %d", ret);
500         return ret;
501 }
502 
503 /*
504  * deliver messages to a call
505  */
506 static void afs_deliver_to_call(struct afs_call *call)
507 {
508         enum afs_call_state state;
509         u32 abort_code, remote_abort = 0;
510         int ret;
511 
512         _enter("%s", call->type->name);
513 
514         while (state = READ_ONCE(call->state),
515                state == AFS_CALL_CL_AWAIT_REPLY ||
516                state == AFS_CALL_SV_AWAIT_OP_ID ||
517                state == AFS_CALL_SV_AWAIT_REQUEST ||
518                state == AFS_CALL_SV_AWAIT_ACK
519                ) {
520                 if (state == AFS_CALL_SV_AWAIT_ACK) {
521                         iov_iter_kvec(&call->iter, READ, NULL, 0, 0);
522                         ret = rxrpc_kernel_recv_data(call->net->socket,
523                                                      call->rxcall, &call->iter,
524                                                      false, &remote_abort,
525                                                      &call->service_id);
526                         trace_afs_receive_data(call, &call->iter, false, ret);
527 
528                         if (ret == -EINPROGRESS || ret == -EAGAIN)
529                                 return;
530                         if (ret < 0 || ret == 1) {
531                                 if (ret == 1)
532                                         ret = 0;
533                                 goto call_complete;
534                         }
535                         return;
536                 }
537 
538                 if (call->want_reply_time &&
539                     rxrpc_kernel_get_reply_time(call->net->socket,
540                                                 call->rxcall,
541                                                 &call->reply_time))
542                         call->want_reply_time = false;
543 
544                 ret = call->type->deliver(call);
545                 state = READ_ONCE(call->state);
546                 switch (ret) {
547                 case 0:
548                         afs_queue_call_work(call);
549                         if (state == AFS_CALL_CL_PROC_REPLY) {
550                                 if (call->cbi)
551                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
552                                                 &call->cbi->server->flags);
553                                 goto call_complete;
554                         }
555                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
556                         goto done;
557                 case -EINPROGRESS:
558                 case -EAGAIN:
559                         goto out;
560                 case -ECONNABORTED:
561                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
562                         goto done;
563                 case -ENOTSUPP:
564                         abort_code = RXGEN_OPCODE;
565                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
566                                                 abort_code, ret, "KIV");
567                         goto local_abort;
568                 case -EIO:
569                         pr_err("kAFS: Call %u in bad state %u\n",
570                                call->debug_id, state);
571                         /* Fall through */
572                 case -ENODATA:
573                 case -EBADMSG:
574                 case -EMSGSIZE:
575                 default:
576                         abort_code = RXGEN_CC_UNMARSHAL;
577                         if (state != AFS_CALL_CL_AWAIT_REPLY)
578                                 abort_code = RXGEN_SS_UNMARSHAL;
579                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
580                                                 abort_code, ret, "KUM");
581                         goto local_abort;
582                 }
583         }
584 
585 done:
586         if (call->type->done)
587                 call->type->done(call);
588         if (state == AFS_CALL_COMPLETE && call->incoming)
589                 afs_put_call(call);
590 out:
591         _leave("");
592         return;
593 
594 local_abort:
595         abort_code = 0;
596 call_complete:
597         afs_set_call_complete(call, ret, remote_abort);
598         state = AFS_CALL_COMPLETE;
599         goto done;
600 }
601 
602 /*
603  * wait synchronously for a call to complete
604  */
605 static long afs_wait_for_call_to_complete(struct afs_call *call,
606                                           struct afs_addr_cursor *ac)
607 {
608         signed long rtt2, timeout;
609         long ret;
610         bool stalled = false;
611         u64 rtt;
612         u32 life, last_life;
613 
614         DECLARE_WAITQUEUE(myself, current);
615 
616         _enter("");
617 
618         rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
619         rtt2 = nsecs_to_jiffies64(rtt) * 2;
620         if (rtt2 < 2)
621                 rtt2 = 2;
622 
623         timeout = rtt2;
624         last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
625 
626         add_wait_queue(&call->waitq, &myself);
627         for (;;) {
628                 set_current_state(TASK_UNINTERRUPTIBLE);
629 
630                 /* deliver any messages that are in the queue */
631                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
632                     call->need_attention) {
633                         call->need_attention = false;
634                         __set_current_state(TASK_RUNNING);
635                         afs_deliver_to_call(call);
636                         continue;
637                 }
638 
639                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
640                         break;
641 
642                 life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
643                 if (timeout == 0 &&
644                     life == last_life && signal_pending(current)) {
645                         if (stalled)
646                                 break;
647                         __set_current_state(TASK_RUNNING);
648                         rxrpc_kernel_probe_life(call->net->socket, call->rxcall);
649                         timeout = rtt2;
650                         stalled = true;
651                         continue;
652                 }
653 
654                 if (life != last_life) {
655                         timeout = rtt2;
656                         last_life = life;
657                         stalled = false;
658                 }
659 
660                 timeout = schedule_timeout(timeout);
661         }
662 
663         remove_wait_queue(&call->waitq, &myself);
664         __set_current_state(TASK_RUNNING);
665 
666         /* Kill off the call if it's still live. */
667         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
668                 _debug("call interrupted");
669                 if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
670                                             RX_USER_ABORT, -EINTR, "KWI"))
671                         afs_set_call_complete(call, -EINTR, 0);
672         }
673 
674         spin_lock_bh(&call->state_lock);
675         ac->abort_code = call->abort_code;
676         ac->error = call->error;
677         spin_unlock_bh(&call->state_lock);
678 
679         ret = ac->error;
680         switch (ret) {
681         case 0:
682                 if (call->ret_reply0) {
683                         ret = (long)call->reply[0];
684                         call->reply[0] = NULL;
685                 }
686                 /* Fall through */
687         case -ECONNABORTED:
688                 ac->responded = true;
689                 break;
690         }
691 
692         _debug("call complete");
693         afs_put_call(call);
694         _leave(" = %p", (void *)ret);
695         return ret;
696 }
697 
698 /*
699  * wake up a waiting call
700  */
701 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
702                                     unsigned long call_user_ID)
703 {
704         struct afs_call *call = (struct afs_call *)call_user_ID;
705 
706         call->need_attention = true;
707         wake_up(&call->waitq);
708 }
709 
710 /*
711  * wake up an asynchronous call
712  */
713 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
714                                    unsigned long call_user_ID)
715 {
716         struct afs_call *call = (struct afs_call *)call_user_ID;
717         int u;
718 
719         trace_afs_notify_call(rxcall, call);
720         call->need_attention = true;
721 
722         u = atomic_fetch_add_unless(&call->usage, 1, 0);
723         if (u != 0) {
724                 trace_afs_call(call, afs_call_trace_wake, u,
725                                atomic_read(&call->net->nr_outstanding_calls),
726                                __builtin_return_address(0));
727 
728                 if (!queue_work(afs_async_calls, &call->async_work))
729                         afs_put_call(call);
730         }
731 }
732 
733 /*
734  * Delete an asynchronous call.  The work item carries a ref to the call struct
735  * that we need to release.
736  */
737 static void afs_delete_async_call(struct work_struct *work)
738 {
739         struct afs_call *call = container_of(work, struct afs_call, async_work);
740 
741         _enter("");
742 
743         afs_put_call(call);
744 
745         _leave("");
746 }
747 
748 /*
749  * Perform I/O processing on an asynchronous call.  The work item carries a ref
750  * to the call struct that we either need to release or to pass on.
751  */
752 static void afs_process_async_call(struct work_struct *work)
753 {
754         struct afs_call *call = container_of(work, struct afs_call, async_work);
755 
756         _enter("");
757 
758         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
759                 call->need_attention = false;
760                 afs_deliver_to_call(call);
761         }
762 
763         if (call->state == AFS_CALL_COMPLETE) {
764                 /* We have two refs to release - one from the alloc and one
765                  * queued with the work item - and we can't just deallocate the
766                  * call because the work item may be queued again.
767                  */
768                 call->async_work.func = afs_delete_async_call;
769                 if (!queue_work(afs_async_calls, &call->async_work))
770                         afs_put_call(call);
771         }
772 
773         afs_put_call(call);
774         _leave("");
775 }
776 
777 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
778 {
779         struct afs_call *call = (struct afs_call *)user_call_ID;
780 
781         call->rxcall = rxcall;
782 }
783 
784 /*
785  * Charge the incoming call preallocation.
786  */
787 void afs_charge_preallocation(struct work_struct *work)
788 {
789         struct afs_net *net =
790                 container_of(work, struct afs_net, charge_preallocation_work);
791         struct afs_call *call = net->spare_incoming_call;
792 
793         for (;;) {
794                 if (!call) {
795                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
796                         if (!call)
797                                 break;
798 
799                         call->async = true;
800                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
801                         init_waitqueue_head(&call->waitq);
802                         afs_extract_to_tmp(call);
803                 }
804 
805                 if (rxrpc_kernel_charge_accept(net->socket,
806                                                afs_wake_up_async_call,
807                                                afs_rx_attach,
808                                                (unsigned long)call,
809                                                GFP_KERNEL,
810                                                call->debug_id) < 0)
811                         break;
812                 call = NULL;
813         }
814         net->spare_incoming_call = call;
815 }
816 
817 /*
818  * Discard a preallocated call when a socket is shut down.
819  */
820 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
821                                     unsigned long user_call_ID)
822 {
823         struct afs_call *call = (struct afs_call *)user_call_ID;
824 
825         call->rxcall = NULL;
826         afs_put_call(call);
827 }
828 
829 /*
830  * Notification of an incoming call.
831  */
832 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
833                             unsigned long user_call_ID)
834 {
835         struct afs_net *net = afs_sock2net(sk);
836 
837         queue_work(afs_wq, &net->charge_preallocation_work);
838 }
839 
840 /*
841  * Grab the operation ID from an incoming cache manager call.  The socket
842  * buffer is discarded on error or if we don't yet have sufficient data.
843  */
844 static int afs_deliver_cm_op_id(struct afs_call *call)
845 {
846         int ret;
847 
848         _enter("{%zu}", iov_iter_count(call->_iter));
849 
850         /* the operation ID forms the first four bytes of the request data */
851         ret = afs_extract_data(call, true);
852         if (ret < 0)
853                 return ret;
854 
855         call->operation_ID = ntohl(call->tmp);
856         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
857 
858         /* ask the cache manager to route the call (it'll change the call type
859          * if successful) */
860         if (!afs_cm_incoming_call(call))
861                 return -ENOTSUPP;
862 
863         trace_afs_cb_call(call);
864 
865         /* pass responsibility for the remainer of this message off to the
866          * cache manager op */
867         return call->type->deliver(call);
868 }
869 
870 /*
871  * Advance the AFS call state when an RxRPC service call ends the transmit
872  * phase.
873  */
874 static void afs_notify_end_reply_tx(struct sock *sock,
875                                     struct rxrpc_call *rxcall,
876                                     unsigned long call_user_ID)
877 {
878         struct afs_call *call = (struct afs_call *)call_user_ID;
879 
880         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
881 }
882 
883 /*
884  * send an empty reply
885  */
886 void afs_send_empty_reply(struct afs_call *call)
887 {
888         struct afs_net *net = call->net;
889         struct msghdr msg;
890 
891         _enter("");
892 
893         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
894 
895         msg.msg_name            = NULL;
896         msg.msg_namelen         = 0;
897         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
898         msg.msg_control         = NULL;
899         msg.msg_controllen      = 0;
900         msg.msg_flags           = 0;
901 
902         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
903                                        afs_notify_end_reply_tx)) {
904         case 0:
905                 _leave(" [replied]");
906                 return;
907 
908         case -ENOMEM:
909                 _debug("oom");
910                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
911                                         RX_USER_ABORT, -ENOMEM, "KOO");
912         default:
913                 _leave(" [error]");
914                 return;
915         }
916 }
917 
918 /*
919  * send a simple reply
920  */
921 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
922 {
923         struct afs_net *net = call->net;
924         struct msghdr msg;
925         struct kvec iov[1];
926         int n;
927 
928         _enter("");
929 
930         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
931 
932         iov[0].iov_base         = (void *) buf;
933         iov[0].iov_len          = len;
934         msg.msg_name            = NULL;
935         msg.msg_namelen         = 0;
936         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
937         msg.msg_control         = NULL;
938         msg.msg_controllen      = 0;
939         msg.msg_flags           = 0;
940 
941         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
942                                    afs_notify_end_reply_tx);
943         if (n >= 0) {
944                 /* Success */
945                 _leave(" [replied]");
946                 return;
947         }
948 
949         if (n == -ENOMEM) {
950                 _debug("oom");
951                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
952                                         RX_USER_ABORT, -ENOMEM, "KOO");
953         }
954         _leave(" [error]");
955 }
956 
957 /*
958  * Extract a piece of data from the received data socket buffers.
959  */
960 int afs_extract_data(struct afs_call *call, bool want_more)
961 {
962         struct afs_net *net = call->net;
963         struct iov_iter *iter = call->_iter;
964         enum afs_call_state state;
965         u32 remote_abort = 0;
966         int ret;
967 
968         _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
969 
970         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
971                                      want_more, &remote_abort,
972                                      &call->service_id);
973         if (ret == 0 || ret == -EAGAIN)
974                 return ret;
975 
976         state = READ_ONCE(call->state);
977         if (ret == 1) {
978                 switch (state) {
979                 case AFS_CALL_CL_AWAIT_REPLY:
980                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
981                         break;
982                 case AFS_CALL_SV_AWAIT_REQUEST:
983                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
984                         break;
985                 case AFS_CALL_COMPLETE:
986                         kdebug("prem complete %d", call->error);
987                         return afs_io_error(call, afs_io_error_extract);
988                 default:
989                         break;
990                 }
991                 return 0;
992         }
993 
994         afs_set_call_complete(call, ret, remote_abort);
995         return ret;
996 }
997 
998 /*
999  * Log protocol error production.
1000  */
1001 noinline int afs_protocol_error(struct afs_call *call, int error,
1002                                 enum afs_eproto_cause cause)
1003 {
1004         trace_afs_protocol_error(call, error, cause);
1005         return error;
1006 }
1007 

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