Merge branch 'for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
[linux-2.6-microblaze.git] / fs / afs / rxrpc.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Maintain an RxRPC server socket to do AFS communications through
3  *
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7
8 #include <linux/slab.h>
9 #include <linux/sched/signal.h>
10
11 #include <net/sock.h>
12 #include <net/af_rxrpc.h>
13 #include "internal.h"
14 #include "afs_cm.h"
15 #include "protocol_yfs.h"
16
17 struct workqueue_struct *afs_async_calls;
18
19 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
20 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
21 static void afs_process_async_call(struct work_struct *);
22 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
23 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
24 static int afs_deliver_cm_op_id(struct afs_call *);
25
26 /* asynchronous incoming call initial processing */
27 static const struct afs_call_type afs_RXCMxxxx = {
28         .name           = "CB.xxxx",
29         .deliver        = afs_deliver_cm_op_id,
30 };
31
32 /*
33  * open an RxRPC socket and bind it to be a server for callback notifications
34  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
35  */
36 int afs_open_socket(struct afs_net *net)
37 {
38         struct sockaddr_rxrpc srx;
39         struct socket *socket;
40         unsigned int min_level;
41         int ret;
42
43         _enter("");
44
45         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
46         if (ret < 0)
47                 goto error_1;
48
49         socket->sk->sk_allocation = GFP_NOFS;
50
51         /* bind the callback manager's address to make this a server socket */
52         memset(&srx, 0, sizeof(srx));
53         srx.srx_family                  = AF_RXRPC;
54         srx.srx_service                 = CM_SERVICE;
55         srx.transport_type              = SOCK_DGRAM;
56         srx.transport_len               = sizeof(srx.transport.sin6);
57         srx.transport.sin6.sin6_family  = AF_INET6;
58         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
59
60         min_level = RXRPC_SECURITY_ENCRYPT;
61         ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
62                                 (void *)&min_level, sizeof(min_level));
63         if (ret < 0)
64                 goto error_2;
65
66         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
67         if (ret == -EADDRINUSE) {
68                 srx.transport.sin6.sin6_port = 0;
69                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
70         }
71         if (ret < 0)
72                 goto error_2;
73
74         srx.srx_service = YFS_CM_SERVICE;
75         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
76         if (ret < 0)
77                 goto error_2;
78
79         /* Ideally, we'd turn on service upgrade here, but we can't because
80          * OpenAFS is buggy and leaks the userStatus field from packet to
81          * packet and between FS packets and CB packets - so if we try to do an
82          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
83          * it sends back to us.
84          */
85
86         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
87                                            afs_rx_discard_new_call);
88
89         ret = kernel_listen(socket, INT_MAX);
90         if (ret < 0)
91                 goto error_2;
92
93         net->socket = socket;
94         afs_charge_preallocation(&net->charge_preallocation_work);
95         _leave(" = 0");
96         return 0;
97
98 error_2:
99         sock_release(socket);
100 error_1:
101         _leave(" = %d", ret);
102         return ret;
103 }
104
105 /*
106  * close the RxRPC socket AFS was using
107  */
108 void afs_close_socket(struct afs_net *net)
109 {
110         _enter("");
111
112         kernel_listen(net->socket, 0);
113         flush_workqueue(afs_async_calls);
114
115         if (net->spare_incoming_call) {
116                 afs_put_call(net->spare_incoming_call);
117                 net->spare_incoming_call = NULL;
118         }
119
120         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
121         wait_var_event(&net->nr_outstanding_calls,
122                        !atomic_read(&net->nr_outstanding_calls));
123         _debug("no outstanding calls");
124
125         kernel_sock_shutdown(net->socket, SHUT_RDWR);
126         flush_workqueue(afs_async_calls);
127         sock_release(net->socket);
128
129         _debug("dework");
130         _leave("");
131 }
132
133 /*
134  * Allocate a call.
135  */
136 static struct afs_call *afs_alloc_call(struct afs_net *net,
137                                        const struct afs_call_type *type,
138                                        gfp_t gfp)
139 {
140         struct afs_call *call;
141         int o;
142
143         call = kzalloc(sizeof(*call), gfp);
144         if (!call)
145                 return NULL;
146
147         call->type = type;
148         call->net = net;
149         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
150         atomic_set(&call->usage, 1);
151         INIT_WORK(&call->async_work, afs_process_async_call);
152         init_waitqueue_head(&call->waitq);
153         spin_lock_init(&call->state_lock);
154         call->iter = &call->def_iter;
155
156         o = atomic_inc_return(&net->nr_outstanding_calls);
157         trace_afs_call(call, afs_call_trace_alloc, 1, o,
158                        __builtin_return_address(0));
159         return call;
160 }
161
162 /*
163  * Dispose of a reference on a call.
164  */
165 void afs_put_call(struct afs_call *call)
166 {
167         struct afs_net *net = call->net;
168         int n = atomic_dec_return(&call->usage);
169         int o = atomic_read(&net->nr_outstanding_calls);
170
171         trace_afs_call(call, afs_call_trace_put, n, o,
172                        __builtin_return_address(0));
173
174         ASSERTCMP(n, >=, 0);
175         if (n == 0) {
176                 ASSERT(!work_pending(&call->async_work));
177                 ASSERT(call->type->name != NULL);
178
179                 if (call->rxcall) {
180                         rxrpc_kernel_end_call(net->socket, call->rxcall);
181                         call->rxcall = NULL;
182                 }
183                 if (call->type->destructor)
184                         call->type->destructor(call);
185
186                 afs_put_server(call->net, call->server, afs_server_trace_put_call);
187                 afs_put_cb_interest(call->net, call->cbi);
188                 afs_put_addrlist(call->alist);
189                 kfree(call->request);
190
191                 trace_afs_call(call, afs_call_trace_free, 0, o,
192                                __builtin_return_address(0));
193                 kfree(call);
194
195                 o = atomic_dec_return(&net->nr_outstanding_calls);
196                 if (o == 0)
197                         wake_up_var(&net->nr_outstanding_calls);
198         }
199 }
200
201 static struct afs_call *afs_get_call(struct afs_call *call,
202                                      enum afs_call_trace why)
203 {
204         int u = atomic_inc_return(&call->usage);
205
206         trace_afs_call(call, why, u,
207                        atomic_read(&call->net->nr_outstanding_calls),
208                        __builtin_return_address(0));
209         return call;
210 }
211
212 /*
213  * Queue the call for actual work.
214  */
215 static void afs_queue_call_work(struct afs_call *call)
216 {
217         if (call->type->work) {
218                 INIT_WORK(&call->work, call->type->work);
219
220                 afs_get_call(call, afs_call_trace_work);
221                 if (!queue_work(afs_wq, &call->work))
222                         afs_put_call(call);
223         }
224 }
225
226 /*
227  * allocate a call with flat request and reply buffers
228  */
229 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
230                                      const struct afs_call_type *type,
231                                      size_t request_size, size_t reply_max)
232 {
233         struct afs_call *call;
234
235         call = afs_alloc_call(net, type, GFP_NOFS);
236         if (!call)
237                 goto nomem_call;
238
239         if (request_size) {
240                 call->request_size = request_size;
241                 call->request = kmalloc(request_size, GFP_NOFS);
242                 if (!call->request)
243                         goto nomem_free;
244         }
245
246         if (reply_max) {
247                 call->reply_max = reply_max;
248                 call->buffer = kmalloc(reply_max, GFP_NOFS);
249                 if (!call->buffer)
250                         goto nomem_free;
251         }
252
253         afs_extract_to_buf(call, call->reply_max);
254         call->operation_ID = type->op;
255         init_waitqueue_head(&call->waitq);
256         return call;
257
258 nomem_free:
259         afs_put_call(call);
260 nomem_call:
261         return NULL;
262 }
263
264 /*
265  * clean up a call with flat buffer
266  */
267 void afs_flat_call_destructor(struct afs_call *call)
268 {
269         _enter("");
270
271         kfree(call->request);
272         call->request = NULL;
273         kfree(call->buffer);
274         call->buffer = NULL;
275 }
276
277 #define AFS_BVEC_MAX 8
278
279 /*
280  * Load the given bvec with the next few pages.
281  */
282 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
283                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
284                           unsigned offset)
285 {
286         struct page *pages[AFS_BVEC_MAX];
287         unsigned int nr, n, i, to, bytes = 0;
288
289         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
290         n = find_get_pages_contig(call->mapping, first, nr, pages);
291         ASSERTCMP(n, ==, nr);
292
293         msg->msg_flags |= MSG_MORE;
294         for (i = 0; i < nr; i++) {
295                 to = PAGE_SIZE;
296                 if (first + i >= last) {
297                         to = call->last_to;
298                         msg->msg_flags &= ~MSG_MORE;
299                 }
300                 bv[i].bv_page = pages[i];
301                 bv[i].bv_len = to - offset;
302                 bv[i].bv_offset = offset;
303                 bytes += to - offset;
304                 offset = 0;
305         }
306
307         iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
308 }
309
310 /*
311  * Advance the AFS call state when the RxRPC call ends the transmit phase.
312  */
313 static void afs_notify_end_request_tx(struct sock *sock,
314                                       struct rxrpc_call *rxcall,
315                                       unsigned long call_user_ID)
316 {
317         struct afs_call *call = (struct afs_call *)call_user_ID;
318
319         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
320 }
321
322 /*
323  * attach the data from a bunch of pages on an inode to a call
324  */
325 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
326 {
327         struct bio_vec bv[AFS_BVEC_MAX];
328         unsigned int bytes, nr, loop, offset;
329         pgoff_t first = call->first, last = call->last;
330         int ret;
331
332         offset = call->first_offset;
333         call->first_offset = 0;
334
335         do {
336                 afs_load_bvec(call, msg, bv, first, last, offset);
337                 trace_afs_send_pages(call, msg, first, last, offset);
338
339                 offset = 0;
340                 bytes = msg->msg_iter.count;
341                 nr = msg->msg_iter.nr_segs;
342
343                 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
344                                              bytes, afs_notify_end_request_tx);
345                 for (loop = 0; loop < nr; loop++)
346                         put_page(bv[loop].bv_page);
347                 if (ret < 0)
348                         break;
349
350                 first += nr;
351         } while (first <= last);
352
353         trace_afs_sent_pages(call, call->first, last, first, ret);
354         return ret;
355 }
356
357 /*
358  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
359  * error is stored into the call struct, which the caller must check for.
360  */
361 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
362 {
363         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
364         struct rxrpc_call *rxcall;
365         struct msghdr msg;
366         struct kvec iov[1];
367         s64 tx_total_len;
368         int ret;
369
370         _enter(",{%pISp},", &srx->transport);
371
372         ASSERT(call->type != NULL);
373         ASSERT(call->type->name != NULL);
374
375         _debug("____MAKE %p{%s,%x} [%d]____",
376                call, call->type->name, key_serial(call->key),
377                atomic_read(&call->net->nr_outstanding_calls));
378
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         /* If the call is going to be asynchronous, we need an extra ref for
402          * the call to hold itself so the caller need not hang on to its ref.
403          */
404         if (call->async) {
405                 afs_get_call(call, afs_call_trace_get);
406                 call->drop_ref = true;
407         }
408
409         /* create a call */
410         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
411                                          (unsigned long)call,
412                                          tx_total_len, gfp,
413                                          (call->async ?
414                                           afs_wake_up_async_call :
415                                           afs_wake_up_call_waiter),
416                                          call->upgrade,
417                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
418                                           RXRPC_UNINTERRUPTIBLE),
419                                          call->debug_id);
420         if (IS_ERR(rxcall)) {
421                 ret = PTR_ERR(rxcall);
422                 call->error = ret;
423                 goto error_kill_call;
424         }
425
426         call->rxcall = rxcall;
427
428         if (call->max_lifespan)
429                 rxrpc_kernel_set_max_life(call->net->socket, rxcall,
430                                           call->max_lifespan);
431
432         /* send the request */
433         iov[0].iov_base = call->request;
434         iov[0].iov_len  = call->request_size;
435
436         msg.msg_name            = NULL;
437         msg.msg_namelen         = 0;
438         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
439         msg.msg_control         = NULL;
440         msg.msg_controllen      = 0;
441         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
442
443         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
444                                      &msg, call->request_size,
445                                      afs_notify_end_request_tx);
446         if (ret < 0)
447                 goto error_do_abort;
448
449         if (call->send_pages) {
450                 ret = afs_send_pages(call, &msg);
451                 if (ret < 0)
452                         goto error_do_abort;
453         }
454
455         /* Note that at this point, we may have received the reply or an abort
456          * - and an asynchronous call may already have completed.
457          *
458          * afs_wait_for_call_to_complete(call, ac)
459          * must be called to synchronously clean up.
460          */
461         return;
462
463 error_do_abort:
464         if (ret != -ECONNABORTED) {
465                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
466                                         RX_USER_ABORT, ret, "KSD");
467         } else {
468                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
469                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
470                                        &msg.msg_iter, false,
471                                        &call->abort_code, &call->service_id);
472                 ac->abort_code = call->abort_code;
473                 ac->responded = true;
474         }
475         call->error = ret;
476         trace_afs_call_done(call);
477 error_kill_call:
478         if (call->type->done)
479                 call->type->done(call);
480
481         /* We need to dispose of the extra ref we grabbed for an async call.
482          * The call, however, might be queued on afs_async_calls and we need to
483          * make sure we don't get any more notifications that might requeue it.
484          */
485         if (call->rxcall) {
486                 rxrpc_kernel_end_call(call->net->socket, call->rxcall);
487                 call->rxcall = NULL;
488         }
489         if (call->async) {
490                 if (cancel_work_sync(&call->async_work))
491                         afs_put_call(call);
492                 afs_put_call(call);
493         }
494
495         ac->error = ret;
496         call->state = AFS_CALL_COMPLETE;
497         _leave(" = %d", ret);
498 }
499
500 /*
501  * deliver messages to a call
502  */
503 static void afs_deliver_to_call(struct afs_call *call)
504 {
505         enum afs_call_state state;
506         u32 abort_code, remote_abort = 0;
507         int ret;
508
509         _enter("%s", call->type->name);
510
511         while (state = READ_ONCE(call->state),
512                state == AFS_CALL_CL_AWAIT_REPLY ||
513                state == AFS_CALL_SV_AWAIT_OP_ID ||
514                state == AFS_CALL_SV_AWAIT_REQUEST ||
515                state == AFS_CALL_SV_AWAIT_ACK
516                ) {
517                 if (state == AFS_CALL_SV_AWAIT_ACK) {
518                         iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
519                         ret = rxrpc_kernel_recv_data(call->net->socket,
520                                                      call->rxcall, &call->def_iter,
521                                                      false, &remote_abort,
522                                                      &call->service_id);
523                         trace_afs_receive_data(call, &call->def_iter, false, ret);
524
525                         if (ret == -EINPROGRESS || ret == -EAGAIN)
526                                 return;
527                         if (ret < 0 || ret == 1) {
528                                 if (ret == 1)
529                                         ret = 0;
530                                 goto call_complete;
531                         }
532                         return;
533                 }
534
535                 if (!call->have_reply_time &&
536                     rxrpc_kernel_get_reply_time(call->net->socket,
537                                                 call->rxcall,
538                                                 &call->reply_time))
539                         call->have_reply_time = true;
540
541                 ret = call->type->deliver(call);
542                 state = READ_ONCE(call->state);
543                 switch (ret) {
544                 case 0:
545                         afs_queue_call_work(call);
546                         if (state == AFS_CALL_CL_PROC_REPLY) {
547                                 if (call->cbi)
548                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
549                                                 &call->cbi->server->flags);
550                                 goto call_complete;
551                         }
552                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
553                         goto done;
554                 case -EINPROGRESS:
555                 case -EAGAIN:
556                         goto out;
557                 case -ECONNABORTED:
558                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
559                         goto done;
560                 case -ENOTSUPP:
561                         abort_code = RXGEN_OPCODE;
562                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
563                                                 abort_code, ret, "KIV");
564                         goto local_abort;
565                 case -EIO:
566                         pr_err("kAFS: Call %u in bad state %u\n",
567                                call->debug_id, state);
568                         /* Fall through */
569                 case -ENODATA:
570                 case -EBADMSG:
571                 case -EMSGSIZE:
572                         abort_code = RXGEN_CC_UNMARSHAL;
573                         if (state != AFS_CALL_CL_AWAIT_REPLY)
574                                 abort_code = RXGEN_SS_UNMARSHAL;
575                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
576                                                 abort_code, ret, "KUM");
577                         goto local_abort;
578                 default:
579                         abort_code = RX_USER_ABORT;
580                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
581                                                 abort_code, ret, "KER");
582                         goto local_abort;
583                 }
584         }
585
586 done:
587         if (call->type->done)
588                 call->type->done(call);
589 out:
590         _leave("");
591         return;
592
593 local_abort:
594         abort_code = 0;
595 call_complete:
596         afs_set_call_complete(call, ret, remote_abort);
597         state = AFS_CALL_COMPLETE;
598         goto done;
599 }
600
601 /*
602  * Wait synchronously for a call to complete and clean up the call struct.
603  */
604 long afs_wait_for_call_to_complete(struct afs_call *call,
605                                    struct afs_addr_cursor *ac)
606 {
607         long ret;
608         bool rxrpc_complete = false;
609
610         DECLARE_WAITQUEUE(myself, current);
611
612         _enter("");
613
614         ret = call->error;
615         if (ret < 0)
616                 goto out;
617
618         add_wait_queue(&call->waitq, &myself);
619         for (;;) {
620                 set_current_state(TASK_UNINTERRUPTIBLE);
621
622                 /* deliver any messages that are in the queue */
623                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
624                     call->need_attention) {
625                         call->need_attention = false;
626                         __set_current_state(TASK_RUNNING);
627                         afs_deliver_to_call(call);
628                         continue;
629                 }
630
631                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
632                         break;
633
634                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
635                         /* rxrpc terminated the call. */
636                         rxrpc_complete = true;
637                         break;
638                 }
639
640                 schedule();
641         }
642
643         remove_wait_queue(&call->waitq, &myself);
644         __set_current_state(TASK_RUNNING);
645
646         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
647                 if (rxrpc_complete) {
648                         afs_set_call_complete(call, call->error, call->abort_code);
649                 } else {
650                         /* Kill off the call if it's still live. */
651                         _debug("call interrupted");
652                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
653                                                     RX_USER_ABORT, -EINTR, "KWI"))
654                                 afs_set_call_complete(call, -EINTR, 0);
655                 }
656         }
657
658         spin_lock_bh(&call->state_lock);
659         ac->abort_code = call->abort_code;
660         ac->error = call->error;
661         spin_unlock_bh(&call->state_lock);
662
663         ret = ac->error;
664         switch (ret) {
665         case 0:
666                 ret = call->ret0;
667                 call->ret0 = 0;
668
669                 /* Fall through */
670         case -ECONNABORTED:
671                 ac->responded = true;
672                 break;
673         }
674
675 out:
676         _debug("call complete");
677         afs_put_call(call);
678         _leave(" = %p", (void *)ret);
679         return ret;
680 }
681
682 /*
683  * wake up a waiting call
684  */
685 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
686                                     unsigned long call_user_ID)
687 {
688         struct afs_call *call = (struct afs_call *)call_user_ID;
689
690         call->need_attention = true;
691         wake_up(&call->waitq);
692 }
693
694 /*
695  * wake up an asynchronous call
696  */
697 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
698                                    unsigned long call_user_ID)
699 {
700         struct afs_call *call = (struct afs_call *)call_user_ID;
701         int u;
702
703         trace_afs_notify_call(rxcall, call);
704         call->need_attention = true;
705
706         u = atomic_fetch_add_unless(&call->usage, 1, 0);
707         if (u != 0) {
708                 trace_afs_call(call, afs_call_trace_wake, u + 1,
709                                atomic_read(&call->net->nr_outstanding_calls),
710                                __builtin_return_address(0));
711
712                 if (!queue_work(afs_async_calls, &call->async_work))
713                         afs_put_call(call);
714         }
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         afs_put_call(call);
733         _leave("");
734 }
735
736 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
737 {
738         struct afs_call *call = (struct afs_call *)user_call_ID;
739
740         call->rxcall = rxcall;
741 }
742
743 /*
744  * Charge the incoming call preallocation.
745  */
746 void afs_charge_preallocation(struct work_struct *work)
747 {
748         struct afs_net *net =
749                 container_of(work, struct afs_net, charge_preallocation_work);
750         struct afs_call *call = net->spare_incoming_call;
751
752         for (;;) {
753                 if (!call) {
754                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
755                         if (!call)
756                                 break;
757
758                         call->drop_ref = true;
759                         call->async = true;
760                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
761                         init_waitqueue_head(&call->waitq);
762                         afs_extract_to_tmp(call);
763                 }
764
765                 if (rxrpc_kernel_charge_accept(net->socket,
766                                                afs_wake_up_async_call,
767                                                afs_rx_attach,
768                                                (unsigned long)call,
769                                                GFP_KERNEL,
770                                                call->debug_id) < 0)
771                         break;
772                 call = NULL;
773         }
774         net->spare_incoming_call = call;
775 }
776
777 /*
778  * Discard a preallocated call when a socket is shut down.
779  */
780 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
781                                     unsigned long user_call_ID)
782 {
783         struct afs_call *call = (struct afs_call *)user_call_ID;
784
785         call->rxcall = NULL;
786         afs_put_call(call);
787 }
788
789 /*
790  * Notification of an incoming call.
791  */
792 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
793                             unsigned long user_call_ID)
794 {
795         struct afs_net *net = afs_sock2net(sk);
796
797         queue_work(afs_wq, &net->charge_preallocation_work);
798 }
799
800 /*
801  * Grab the operation ID from an incoming cache manager call.  The socket
802  * buffer is discarded on error or if we don't yet have sufficient data.
803  */
804 static int afs_deliver_cm_op_id(struct afs_call *call)
805 {
806         int ret;
807
808         _enter("{%zu}", iov_iter_count(call->iter));
809
810         /* the operation ID forms the first four bytes of the request data */
811         ret = afs_extract_data(call, true);
812         if (ret < 0)
813                 return ret;
814
815         call->operation_ID = ntohl(call->tmp);
816         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
817
818         /* ask the cache manager to route the call (it'll change the call type
819          * if successful) */
820         if (!afs_cm_incoming_call(call))
821                 return -ENOTSUPP;
822
823         trace_afs_cb_call(call);
824
825         /* pass responsibility for the remainer of this message off to the
826          * cache manager op */
827         return call->type->deliver(call);
828 }
829
830 /*
831  * Advance the AFS call state when an RxRPC service call ends the transmit
832  * phase.
833  */
834 static void afs_notify_end_reply_tx(struct sock *sock,
835                                     struct rxrpc_call *rxcall,
836                                     unsigned long call_user_ID)
837 {
838         struct afs_call *call = (struct afs_call *)call_user_ID;
839
840         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
841 }
842
843 /*
844  * send an empty reply
845  */
846 void afs_send_empty_reply(struct afs_call *call)
847 {
848         struct afs_net *net = call->net;
849         struct msghdr msg;
850
851         _enter("");
852
853         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
854
855         msg.msg_name            = NULL;
856         msg.msg_namelen         = 0;
857         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
858         msg.msg_control         = NULL;
859         msg.msg_controllen      = 0;
860         msg.msg_flags           = 0;
861
862         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
863                                        afs_notify_end_reply_tx)) {
864         case 0:
865                 _leave(" [replied]");
866                 return;
867
868         case -ENOMEM:
869                 _debug("oom");
870                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
871                                         RX_USER_ABORT, -ENOMEM, "KOO");
872                 /* Fall through */
873         default:
874                 _leave(" [error]");
875                 return;
876         }
877 }
878
879 /*
880  * send a simple reply
881  */
882 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
883 {
884         struct afs_net *net = call->net;
885         struct msghdr msg;
886         struct kvec iov[1];
887         int n;
888
889         _enter("");
890
891         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
892
893         iov[0].iov_base         = (void *) buf;
894         iov[0].iov_len          = len;
895         msg.msg_name            = NULL;
896         msg.msg_namelen         = 0;
897         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
898         msg.msg_control         = NULL;
899         msg.msg_controllen      = 0;
900         msg.msg_flags           = 0;
901
902         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
903                                    afs_notify_end_reply_tx);
904         if (n >= 0) {
905                 /* Success */
906                 _leave(" [replied]");
907                 return;
908         }
909
910         if (n == -ENOMEM) {
911                 _debug("oom");
912                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
913                                         RX_USER_ABORT, -ENOMEM, "KOO");
914         }
915         _leave(" [error]");
916 }
917
918 /*
919  * Extract a piece of data from the received data socket buffers.
920  */
921 int afs_extract_data(struct afs_call *call, bool want_more)
922 {
923         struct afs_net *net = call->net;
924         struct iov_iter *iter = call->iter;
925         enum afs_call_state state;
926         u32 remote_abort = 0;
927         int ret;
928
929         _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
930
931         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
932                                      want_more, &remote_abort,
933                                      &call->service_id);
934         if (ret == 0 || ret == -EAGAIN)
935                 return ret;
936
937         state = READ_ONCE(call->state);
938         if (ret == 1) {
939                 switch (state) {
940                 case AFS_CALL_CL_AWAIT_REPLY:
941                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
942                         break;
943                 case AFS_CALL_SV_AWAIT_REQUEST:
944                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
945                         break;
946                 case AFS_CALL_COMPLETE:
947                         kdebug("prem complete %d", call->error);
948                         return afs_io_error(call, afs_io_error_extract);
949                 default:
950                         break;
951                 }
952                 return 0;
953         }
954
955         afs_set_call_complete(call, ret, remote_abort);
956         return ret;
957 }
958
959 /*
960  * Log protocol error production.
961  */
962 noinline int afs_protocol_error(struct afs_call *call, int error,
963                                 enum afs_eproto_cause cause)
964 {
965         trace_afs_protocol_error(call, error, cause);
966         return error;
967 }