1 /* Maintain an RxRPC server socket to do AFS communications through
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #include <linux/slab.h>
13 #include <linux/sched/signal.h>
16 #include <net/af_rxrpc.h>
17 #include <rxrpc/packet.h>
21 struct socket *afs_socket; /* my RxRPC socket */
22 static struct workqueue_struct *afs_async_calls;
23 static struct afs_call *afs_spare_incoming_call;
24 atomic_t afs_outstanding_calls;
26 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
27 static int afs_wait_for_call_to_complete(struct afs_call *);
28 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
29 static void afs_process_async_call(struct work_struct *);
30 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
31 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
32 static int afs_deliver_cm_op_id(struct afs_call *);
34 /* asynchronous incoming call initial processing */
35 static const struct afs_call_type afs_RXCMxxxx = {
37 .deliver = afs_deliver_cm_op_id,
38 .abort_to_error = afs_abort_to_error,
41 static void afs_charge_preallocation(struct work_struct *);
43 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
45 static int afs_wait_atomic_t(atomic_t *p)
52 * open an RxRPC socket and bind it to be a server for callback notifications
53 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
55 int afs_open_socket(void)
57 struct sockaddr_rxrpc srx;
58 struct socket *socket;
64 afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
68 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
72 socket->sk->sk_allocation = GFP_NOFS;
74 /* bind the callback manager's address to make this a server socket */
75 srx.srx_family = AF_RXRPC;
76 srx.srx_service = CM_SERVICE;
77 srx.transport_type = SOCK_DGRAM;
78 srx.transport_len = sizeof(srx.transport.sin);
79 srx.transport.sin.sin_family = AF_INET;
80 srx.transport.sin.sin_port = htons(AFS_CM_PORT);
81 memset(&srx.transport.sin.sin_addr, 0,
82 sizeof(srx.transport.sin.sin_addr));
84 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
88 rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
89 afs_rx_discard_new_call);
91 ret = kernel_listen(socket, INT_MAX);
96 afs_charge_preallocation(NULL);
101 sock_release(socket);
103 destroy_workqueue(afs_async_calls);
105 _leave(" = %d", ret);
110 * close the RxRPC socket AFS was using
112 void afs_close_socket(void)
116 kernel_listen(afs_socket, 0);
117 flush_workqueue(afs_async_calls);
119 if (afs_spare_incoming_call) {
120 afs_put_call(afs_spare_incoming_call);
121 afs_spare_incoming_call = NULL;
124 _debug("outstanding %u", atomic_read(&afs_outstanding_calls));
125 wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
126 TASK_UNINTERRUPTIBLE);
127 _debug("no outstanding calls");
129 kernel_sock_shutdown(afs_socket, SHUT_RDWR);
130 flush_workqueue(afs_async_calls);
131 sock_release(afs_socket);
134 destroy_workqueue(afs_async_calls);
141 static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
144 struct afs_call *call;
147 call = kzalloc(sizeof(*call), gfp);
152 atomic_set(&call->usage, 1);
153 INIT_WORK(&call->async_work, afs_process_async_call);
154 init_waitqueue_head(&call->waitq);
156 o = atomic_inc_return(&afs_outstanding_calls);
157 trace_afs_call(call, afs_call_trace_alloc, 1, o,
158 __builtin_return_address(0));
163 * Dispose of a reference on a call.
165 void afs_put_call(struct afs_call *call)
167 int n = atomic_dec_return(&call->usage);
168 int o = atomic_read(&afs_outstanding_calls);
170 trace_afs_call(call, afs_call_trace_put, n + 1, o,
171 __builtin_return_address(0));
175 ASSERT(!work_pending(&call->async_work));
176 ASSERT(call->type->name != NULL);
179 rxrpc_kernel_end_call(afs_socket, call->rxcall);
182 if (call->type->destructor)
183 call->type->destructor(call);
185 kfree(call->request);
188 o = atomic_dec_return(&afs_outstanding_calls);
189 trace_afs_call(call, afs_call_trace_free, 0, o,
190 __builtin_return_address(0));
192 wake_up_atomic_t(&afs_outstanding_calls);
197 * Queue the call for actual work. Returns 0 unconditionally for convenience.
199 int afs_queue_call_work(struct afs_call *call)
201 int u = atomic_inc_return(&call->usage);
203 trace_afs_call(call, afs_call_trace_work, u,
204 atomic_read(&afs_outstanding_calls),
205 __builtin_return_address(0));
207 INIT_WORK(&call->work, call->type->work);
209 if (!queue_work(afs_wq, &call->work))
215 * allocate a call with flat request and reply buffers
217 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
218 size_t request_size, size_t reply_max)
220 struct afs_call *call;
222 call = afs_alloc_call(type, GFP_NOFS);
227 call->request_size = request_size;
228 call->request = kmalloc(request_size, GFP_NOFS);
234 call->reply_max = reply_max;
235 call->buffer = kmalloc(reply_max, GFP_NOFS);
240 init_waitqueue_head(&call->waitq);
250 * clean up a call with flat buffer
252 void afs_flat_call_destructor(struct afs_call *call)
256 kfree(call->request);
257 call->request = NULL;
263 * attach the data from a bunch of pages on an inode to a call
265 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
268 struct page *pages[8];
269 unsigned count, n, loop, offset, to;
270 pgoff_t first = call->first, last = call->last;
275 offset = call->first_offset;
276 call->first_offset = 0;
279 _debug("attach %lx-%lx", first, last);
281 count = last - first + 1;
282 if (count > ARRAY_SIZE(pages))
283 count = ARRAY_SIZE(pages);
284 n = find_get_pages_contig(call->mapping, first, count, pages);
285 ASSERTCMP(n, ==, count);
291 if (first + loop >= last)
294 msg->msg_flags = MSG_MORE;
295 iov->iov_base = kmap(pages[loop]) + offset;
296 iov->iov_len = to - offset;
299 _debug("- range %u-%u%s",
300 offset, to, msg->msg_flags ? " [more]" : "");
301 iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
302 iov, 1, to - offset);
304 /* have to change the state *before* sending the last
305 * packet as RxRPC might give us the reply before it
306 * returns from sending the request */
307 if (first + loop >= last)
308 call->state = AFS_CALL_AWAIT_REPLY;
309 ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
314 } while (++loop < count);
317 for (loop = 0; loop < count; loop++)
318 put_page(pages[loop]);
321 } while (first <= last);
323 _leave(" = %d", ret);
330 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
333 struct sockaddr_rxrpc srx;
334 struct rxrpc_call *rxcall;
339 _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
341 ASSERT(call->type != NULL);
342 ASSERT(call->type->name != NULL);
344 _debug("____MAKE %p{%s,%x} [%d]____",
345 call, call->type->name, key_serial(call->key),
346 atomic_read(&afs_outstanding_calls));
350 memset(&srx, 0, sizeof(srx));
351 srx.srx_family = AF_RXRPC;
352 srx.srx_service = call->service_id;
353 srx.transport_type = SOCK_DGRAM;
354 srx.transport_len = sizeof(srx.transport.sin);
355 srx.transport.sin.sin_family = AF_INET;
356 srx.transport.sin.sin_port = call->port;
357 memcpy(&srx.transport.sin.sin_addr, addr, 4);
360 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
361 (unsigned long) call, gfp,
363 afs_wake_up_async_call :
364 afs_wake_up_call_waiter));
366 if (IS_ERR(rxcall)) {
367 ret = PTR_ERR(rxcall);
368 goto error_kill_call;
371 call->rxcall = rxcall;
373 /* send the request */
374 iov[0].iov_base = call->request;
375 iov[0].iov_len = call->request_size;
379 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
381 msg.msg_control = NULL;
382 msg.msg_controllen = 0;
383 msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
385 /* have to change the state *before* sending the last packet as RxRPC
386 * might give us the reply before it returns from sending the
388 if (!call->send_pages)
389 call->state = AFS_CALL_AWAIT_REPLY;
390 ret = rxrpc_kernel_send_data(afs_socket, rxcall,
391 &msg, call->request_size);
395 if (call->send_pages) {
396 ret = afs_send_pages(call, &msg, iov);
401 /* at this point, an async call may no longer exist as it may have
402 * already completed */
406 return afs_wait_for_call_to_complete(call);
409 rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
412 _leave(" = %d", ret);
417 * deliver messages to a call
419 static void afs_deliver_to_call(struct afs_call *call)
424 _enter("%s", call->type->name);
426 while (call->state == AFS_CALL_AWAIT_REPLY ||
427 call->state == AFS_CALL_AWAIT_OP_ID ||
428 call->state == AFS_CALL_AWAIT_REQUEST ||
429 call->state == AFS_CALL_AWAIT_ACK
431 if (call->state == AFS_CALL_AWAIT_ACK) {
433 ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
434 NULL, 0, &offset, false,
436 trace_afs_recv_data(call, 0, offset, false, ret);
438 if (ret == -EINPROGRESS || ret == -EAGAIN)
440 if (ret == 1 || ret < 0) {
441 call->state = AFS_CALL_COMPLETE;
447 ret = call->type->deliver(call);
450 if (call->state == AFS_CALL_AWAIT_REPLY)
451 call->state = AFS_CALL_COMPLETE;
457 abort_code = RX_CALL_DEAD;
458 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
459 abort_code, -ret, "KNC");
462 abort_code = RX_INVALID_OPERATION;
463 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
464 abort_code, -ret, "KIV");
470 abort_code = RXGEN_CC_UNMARSHAL;
471 if (call->state != AFS_CALL_AWAIT_REPLY)
472 abort_code = RXGEN_SS_UNMARSHAL;
473 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
474 abort_code, EBADMSG, "KUM");
480 if (call->state == AFS_CALL_COMPLETE && call->incoming)
488 call->state = AFS_CALL_COMPLETE;
493 * wait synchronously for a call to complete
495 static int afs_wait_for_call_to_complete(struct afs_call *call)
497 const char *abort_why;
500 DECLARE_WAITQUEUE(myself, current);
504 add_wait_queue(&call->waitq, &myself);
506 set_current_state(TASK_INTERRUPTIBLE);
508 /* deliver any messages that are in the queue */
509 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
510 call->need_attention = false;
511 __set_current_state(TASK_RUNNING);
512 afs_deliver_to_call(call);
518 if (call->state == AFS_CALL_COMPLETE)
522 if (signal_pending(current))
527 remove_wait_queue(&call->waitq, &myself);
528 __set_current_state(TASK_RUNNING);
531 if (call->state < AFS_CALL_COMPLETE) {
532 _debug("call incomplete");
533 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
534 RX_CALL_DEAD, -ret, abort_why);
537 _debug("call complete");
539 _leave(" = %d", ret);
544 * wake up a waiting call
546 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
547 unsigned long call_user_ID)
549 struct afs_call *call = (struct afs_call *)call_user_ID;
551 call->need_attention = true;
552 wake_up(&call->waitq);
556 * wake up an asynchronous call
558 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
559 unsigned long call_user_ID)
561 struct afs_call *call = (struct afs_call *)call_user_ID;
564 trace_afs_notify_call(rxcall, call);
565 call->need_attention = true;
567 u = __atomic_add_unless(&call->usage, 1, 0);
569 trace_afs_call(call, afs_call_trace_wake, u,
570 atomic_read(&afs_outstanding_calls),
571 __builtin_return_address(0));
573 if (!queue_work(afs_async_calls, &call->async_work))
579 * Delete an asynchronous call. The work item carries a ref to the call struct
580 * that we need to release.
582 static void afs_delete_async_call(struct work_struct *work)
584 struct afs_call *call = container_of(work, struct afs_call, async_work);
594 * Perform I/O processing on an asynchronous call. The work item carries a ref
595 * to the call struct that we either need to release or to pass on.
597 static void afs_process_async_call(struct work_struct *work)
599 struct afs_call *call = container_of(work, struct afs_call, async_work);
603 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
604 call->need_attention = false;
605 afs_deliver_to_call(call);
608 if (call->state == AFS_CALL_COMPLETE) {
611 /* We have two refs to release - one from the alloc and one
612 * queued with the work item - and we can't just deallocate the
613 * call because the work item may be queued again.
615 call->async_work.func = afs_delete_async_call;
616 if (!queue_work(afs_async_calls, &call->async_work))
624 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
626 struct afs_call *call = (struct afs_call *)user_call_ID;
628 call->rxcall = rxcall;
632 * Charge the incoming call preallocation.
634 static void afs_charge_preallocation(struct work_struct *work)
636 struct afs_call *call = afs_spare_incoming_call;
640 call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
645 call->state = AFS_CALL_AWAIT_OP_ID;
646 init_waitqueue_head(&call->waitq);
649 if (rxrpc_kernel_charge_accept(afs_socket,
650 afs_wake_up_async_call,
657 afs_spare_incoming_call = call;
661 * Discard a preallocated call when a socket is shut down.
663 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
664 unsigned long user_call_ID)
666 struct afs_call *call = (struct afs_call *)user_call_ID;
673 * Notification of an incoming call.
675 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
676 unsigned long user_call_ID)
678 queue_work(afs_wq, &afs_charge_preallocation_work);
682 * Grab the operation ID from an incoming cache manager call. The socket
683 * buffer is discarded on error or if we don't yet have sufficient data.
685 static int afs_deliver_cm_op_id(struct afs_call *call)
689 _enter("{%zu}", call->offset);
691 ASSERTCMP(call->offset, <, 4);
693 /* the operation ID forms the first four bytes of the request data */
694 ret = afs_extract_data(call, &call->tmp, 4, true);
698 call->operation_ID = ntohl(call->tmp);
699 call->state = AFS_CALL_AWAIT_REQUEST;
702 /* ask the cache manager to route the call (it'll change the call type
704 if (!afs_cm_incoming_call(call))
707 trace_afs_cb_call(call);
709 /* pass responsibility for the remainer of this message off to the
710 * cache manager op */
711 return call->type->deliver(call);
715 * send an empty reply
717 void afs_send_empty_reply(struct afs_call *call)
725 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
726 msg.msg_control = NULL;
727 msg.msg_controllen = 0;
730 call->state = AFS_CALL_AWAIT_ACK;
731 switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0)) {
733 _leave(" [replied]");
738 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
739 RX_USER_ABORT, ENOMEM, "KOO");
747 * send a simple reply
749 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
757 iov[0].iov_base = (void *) buf;
758 iov[0].iov_len = len;
761 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
762 msg.msg_control = NULL;
763 msg.msg_controllen = 0;
766 call->state = AFS_CALL_AWAIT_ACK;
767 n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len);
770 _leave(" [replied]");
776 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
777 RX_USER_ABORT, ENOMEM, "KOO");
783 * Extract a piece of data from the received data socket buffers.
785 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
790 _enter("{%s,%zu},,%zu,%d",
791 call->type->name, call->offset, count, want_more);
793 ASSERTCMP(call->offset, <=, count);
795 ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
796 buf, count, &call->offset,
797 want_more, &call->abort_code);
798 trace_afs_recv_data(call, count, call->offset, want_more, ret);
799 if (ret == 0 || ret == -EAGAIN)
803 switch (call->state) {
804 case AFS_CALL_AWAIT_REPLY:
805 call->state = AFS_CALL_COMPLETE;
807 case AFS_CALL_AWAIT_REQUEST:
808 call->state = AFS_CALL_REPLYING;
816 if (ret == -ECONNABORTED)
817 call->error = call->type->abort_to_error(call->abort_code);
820 call->state = AFS_CALL_COMPLETE;