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>
14 #include <net/af_rxrpc.h>
15 #include <rxrpc/packet.h>
19 struct socket *afs_socket; /* my RxRPC socket */
20 static struct workqueue_struct *afs_async_calls;
21 static struct afs_call *afs_spare_incoming_call;
22 atomic_t afs_outstanding_calls;
24 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
25 static int afs_wait_for_call_to_complete(struct afs_call *);
26 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
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 *);
32 /* asynchronous incoming call initial processing */
33 static const struct afs_call_type afs_RXCMxxxx = {
35 .deliver = afs_deliver_cm_op_id,
36 .abort_to_error = afs_abort_to_error,
39 static void afs_charge_preallocation(struct work_struct *);
41 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
43 static int afs_wait_atomic_t(atomic_t *p)
50 * open an RxRPC socket and bind it to be a server for callback notifications
51 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
53 int afs_open_socket(void)
55 struct sockaddr_rxrpc srx;
56 struct socket *socket;
62 afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
66 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
70 socket->sk->sk_allocation = GFP_NOFS;
72 /* bind the callback manager's address to make this a server socket */
73 srx.srx_family = AF_RXRPC;
74 srx.srx_service = CM_SERVICE;
75 srx.transport_type = SOCK_DGRAM;
76 srx.transport_len = sizeof(srx.transport.sin);
77 srx.transport.sin.sin_family = AF_INET;
78 srx.transport.sin.sin_port = htons(AFS_CM_PORT);
79 memset(&srx.transport.sin.sin_addr, 0,
80 sizeof(srx.transport.sin.sin_addr));
82 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
86 rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
87 afs_rx_discard_new_call);
89 ret = kernel_listen(socket, INT_MAX);
94 afs_charge_preallocation(NULL);
101 destroy_workqueue(afs_async_calls);
103 _leave(" = %d", ret);
108 * close the RxRPC socket AFS was using
110 void afs_close_socket(void)
114 kernel_listen(afs_socket, 0);
115 flush_workqueue(afs_async_calls);
117 if (afs_spare_incoming_call) {
118 afs_put_call(afs_spare_incoming_call);
119 afs_spare_incoming_call = NULL;
122 _debug("outstanding %u", atomic_read(&afs_outstanding_calls));
123 wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
124 TASK_UNINTERRUPTIBLE);
125 _debug("no outstanding calls");
127 kernel_sock_shutdown(afs_socket, SHUT_RDWR);
128 flush_workqueue(afs_async_calls);
129 sock_release(afs_socket);
132 destroy_workqueue(afs_async_calls);
139 static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
142 struct afs_call *call;
145 call = kzalloc(sizeof(*call), gfp);
150 atomic_set(&call->usage, 1);
151 INIT_WORK(&call->async_work, afs_process_async_call);
152 init_waitqueue_head(&call->waitq);
154 o = atomic_inc_return(&afs_outstanding_calls);
155 trace_afs_call(call, afs_call_trace_alloc, 1, o,
156 __builtin_return_address(0));
161 * Dispose of a reference on a call.
163 void afs_put_call(struct afs_call *call)
165 int n = atomic_dec_return(&call->usage);
166 int o = atomic_read(&afs_outstanding_calls);
168 trace_afs_call(call, afs_call_trace_put, n + 1, o,
169 __builtin_return_address(0));
173 ASSERT(!work_pending(&call->async_work));
174 ASSERT(call->type->name != NULL);
177 rxrpc_kernel_end_call(afs_socket, call->rxcall);
180 if (call->type->destructor)
181 call->type->destructor(call);
183 kfree(call->request);
186 o = atomic_dec_return(&afs_outstanding_calls);
187 trace_afs_call(call, afs_call_trace_free, 0, o,
188 __builtin_return_address(0));
190 wake_up_atomic_t(&afs_outstanding_calls);
195 * Queue the call for actual work. Returns 0 unconditionally for convenience.
197 int afs_queue_call_work(struct afs_call *call)
199 int u = atomic_inc_return(&call->usage);
201 trace_afs_call(call, afs_call_trace_work, u,
202 atomic_read(&afs_outstanding_calls),
203 __builtin_return_address(0));
205 INIT_WORK(&call->work, call->type->work);
207 if (!queue_work(afs_wq, &call->work))
213 * allocate a call with flat request and reply buffers
215 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
216 size_t request_size, size_t reply_max)
218 struct afs_call *call;
220 call = afs_alloc_call(type, GFP_NOFS);
225 call->request_size = request_size;
226 call->request = kmalloc(request_size, GFP_NOFS);
232 call->reply_max = reply_max;
233 call->buffer = kmalloc(reply_max, GFP_NOFS);
238 init_waitqueue_head(&call->waitq);
248 * clean up a call with flat buffer
250 void afs_flat_call_destructor(struct afs_call *call)
254 kfree(call->request);
255 call->request = NULL;
261 * attach the data from a bunch of pages on an inode to a call
263 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
265 struct page *pages[8];
266 unsigned count, n, loop, offset, to;
267 pgoff_t first = call->first, last = call->last;
272 offset = call->first_offset;
273 call->first_offset = 0;
276 _debug("attach %lx-%lx", first, last);
278 count = last - first + 1;
279 if (count > ARRAY_SIZE(pages))
280 count = ARRAY_SIZE(pages);
281 n = find_get_pages_contig(call->mapping, first, count, pages);
282 ASSERTCMP(n, ==, count);
286 struct bio_vec bvec = {.bv_page = pages[loop],
287 .bv_offset = offset};
290 if (first + loop >= last)
293 msg->msg_flags = MSG_MORE;
294 bvec.bv_len = to - offset;
297 _debug("- range %u-%u%s",
298 offset, to, msg->msg_flags ? " [more]" : "");
299 iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC,
300 &bvec, 1, to - offset);
302 /* have to change the state *before* sending the last
303 * packet as RxRPC might give us the reply before it
304 * returns from sending the request */
305 if (first + loop >= last)
306 call->state = AFS_CALL_AWAIT_REPLY;
307 ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
311 } while (++loop < count);
314 for (loop = 0; loop < count; loop++)
315 put_page(pages[loop]);
318 } while (first <= last);
320 _leave(" = %d", ret);
327 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
330 struct sockaddr_rxrpc srx;
331 struct rxrpc_call *rxcall;
336 _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
338 ASSERT(call->type != NULL);
339 ASSERT(call->type->name != NULL);
341 _debug("____MAKE %p{%s,%x} [%d]____",
342 call, call->type->name, key_serial(call->key),
343 atomic_read(&afs_outstanding_calls));
347 memset(&srx, 0, sizeof(srx));
348 srx.srx_family = AF_RXRPC;
349 srx.srx_service = call->service_id;
350 srx.transport_type = SOCK_DGRAM;
351 srx.transport_len = sizeof(srx.transport.sin);
352 srx.transport.sin.sin_family = AF_INET;
353 srx.transport.sin.sin_port = call->port;
354 memcpy(&srx.transport.sin.sin_addr, addr, 4);
357 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
358 (unsigned long) call, gfp,
360 afs_wake_up_async_call :
361 afs_wake_up_call_waiter));
363 if (IS_ERR(rxcall)) {
364 ret = PTR_ERR(rxcall);
365 goto error_kill_call;
368 call->rxcall = rxcall;
370 /* send the request */
371 iov[0].iov_base = call->request;
372 iov[0].iov_len = call->request_size;
376 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
378 msg.msg_control = NULL;
379 msg.msg_controllen = 0;
380 msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
382 /* have to change the state *before* sending the last packet as RxRPC
383 * might give us the reply before it returns from sending the
385 if (!call->send_pages)
386 call->state = AFS_CALL_AWAIT_REPLY;
387 ret = rxrpc_kernel_send_data(afs_socket, rxcall,
388 &msg, call->request_size);
392 if (call->send_pages) {
393 ret = afs_send_pages(call, &msg);
398 /* at this point, an async call may no longer exist as it may have
399 * already completed */
403 return afs_wait_for_call_to_complete(call);
406 rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
409 _leave(" = %d", ret);
414 * deliver messages to a call
416 static void afs_deliver_to_call(struct afs_call *call)
421 _enter("%s", call->type->name);
423 while (call->state == AFS_CALL_AWAIT_REPLY ||
424 call->state == AFS_CALL_AWAIT_OP_ID ||
425 call->state == AFS_CALL_AWAIT_REQUEST ||
426 call->state == AFS_CALL_AWAIT_ACK
428 if (call->state == AFS_CALL_AWAIT_ACK) {
430 ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
431 NULL, 0, &offset, false,
433 trace_afs_recv_data(call, 0, offset, false, ret);
435 if (ret == -EINPROGRESS || ret == -EAGAIN)
437 if (ret == 1 || ret < 0) {
438 call->state = AFS_CALL_COMPLETE;
444 ret = call->type->deliver(call);
447 if (call->state == AFS_CALL_AWAIT_REPLY)
448 call->state = AFS_CALL_COMPLETE;
454 abort_code = RX_CALL_DEAD;
455 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
456 abort_code, -ret, "KNC");
459 abort_code = RX_INVALID_OPERATION;
460 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
461 abort_code, -ret, "KIV");
467 abort_code = RXGEN_CC_UNMARSHAL;
468 if (call->state != AFS_CALL_AWAIT_REPLY)
469 abort_code = RXGEN_SS_UNMARSHAL;
470 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
471 abort_code, EBADMSG, "KUM");
477 if (call->state == AFS_CALL_COMPLETE && call->incoming)
485 call->state = AFS_CALL_COMPLETE;
490 * wait synchronously for a call to complete
492 static int afs_wait_for_call_to_complete(struct afs_call *call)
494 const char *abort_why;
497 DECLARE_WAITQUEUE(myself, current);
501 add_wait_queue(&call->waitq, &myself);
503 set_current_state(TASK_INTERRUPTIBLE);
505 /* deliver any messages that are in the queue */
506 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
507 call->need_attention = false;
508 __set_current_state(TASK_RUNNING);
509 afs_deliver_to_call(call);
515 if (call->state == AFS_CALL_COMPLETE)
519 if (signal_pending(current))
524 remove_wait_queue(&call->waitq, &myself);
525 __set_current_state(TASK_RUNNING);
528 if (call->state < AFS_CALL_COMPLETE) {
529 _debug("call incomplete");
530 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
531 RX_CALL_DEAD, -ret, abort_why);
534 _debug("call complete");
536 _leave(" = %d", ret);
541 * wake up a waiting call
543 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
544 unsigned long call_user_ID)
546 struct afs_call *call = (struct afs_call *)call_user_ID;
548 call->need_attention = true;
549 wake_up(&call->waitq);
553 * wake up an asynchronous call
555 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
556 unsigned long call_user_ID)
558 struct afs_call *call = (struct afs_call *)call_user_ID;
561 trace_afs_notify_call(rxcall, call);
562 call->need_attention = true;
564 u = __atomic_add_unless(&call->usage, 1, 0);
566 trace_afs_call(call, afs_call_trace_wake, u,
567 atomic_read(&afs_outstanding_calls),
568 __builtin_return_address(0));
570 if (!queue_work(afs_async_calls, &call->async_work))
576 * Delete an asynchronous call. The work item carries a ref to the call struct
577 * that we need to release.
579 static void afs_delete_async_call(struct work_struct *work)
581 struct afs_call *call = container_of(work, struct afs_call, async_work);
591 * Perform I/O processing on an asynchronous call. The work item carries a ref
592 * to the call struct that we either need to release or to pass on.
594 static void afs_process_async_call(struct work_struct *work)
596 struct afs_call *call = container_of(work, struct afs_call, async_work);
600 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
601 call->need_attention = false;
602 afs_deliver_to_call(call);
605 if (call->state == AFS_CALL_COMPLETE) {
608 /* We have two refs to release - one from the alloc and one
609 * queued with the work item - and we can't just deallocate the
610 * call because the work item may be queued again.
612 call->async_work.func = afs_delete_async_call;
613 if (!queue_work(afs_async_calls, &call->async_work))
621 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
623 struct afs_call *call = (struct afs_call *)user_call_ID;
625 call->rxcall = rxcall;
629 * Charge the incoming call preallocation.
631 static void afs_charge_preallocation(struct work_struct *work)
633 struct afs_call *call = afs_spare_incoming_call;
637 call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
642 call->state = AFS_CALL_AWAIT_OP_ID;
643 init_waitqueue_head(&call->waitq);
646 if (rxrpc_kernel_charge_accept(afs_socket,
647 afs_wake_up_async_call,
654 afs_spare_incoming_call = call;
658 * Discard a preallocated call when a socket is shut down.
660 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
661 unsigned long user_call_ID)
663 struct afs_call *call = (struct afs_call *)user_call_ID;
670 * Notification of an incoming call.
672 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
673 unsigned long user_call_ID)
675 queue_work(afs_wq, &afs_charge_preallocation_work);
679 * Grab the operation ID from an incoming cache manager call. The socket
680 * buffer is discarded on error or if we don't yet have sufficient data.
682 static int afs_deliver_cm_op_id(struct afs_call *call)
686 _enter("{%zu}", call->offset);
688 ASSERTCMP(call->offset, <, 4);
690 /* the operation ID forms the first four bytes of the request data */
691 ret = afs_extract_data(call, &call->tmp, 4, true);
695 call->operation_ID = ntohl(call->tmp);
696 call->state = AFS_CALL_AWAIT_REQUEST;
699 /* ask the cache manager to route the call (it'll change the call type
701 if (!afs_cm_incoming_call(call))
704 trace_afs_cb_call(call);
706 /* pass responsibility for the remainer of this message off to the
707 * cache manager op */
708 return call->type->deliver(call);
712 * send an empty reply
714 void afs_send_empty_reply(struct afs_call *call)
722 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
723 msg.msg_control = NULL;
724 msg.msg_controllen = 0;
727 call->state = AFS_CALL_AWAIT_ACK;
728 switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0)) {
730 _leave(" [replied]");
735 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
736 RX_USER_ABORT, ENOMEM, "KOO");
744 * send a simple reply
746 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
754 iov[0].iov_base = (void *) buf;
755 iov[0].iov_len = len;
758 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
759 msg.msg_control = NULL;
760 msg.msg_controllen = 0;
763 call->state = AFS_CALL_AWAIT_ACK;
764 n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len);
767 _leave(" [replied]");
773 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
774 RX_USER_ABORT, ENOMEM, "KOO");
780 * Extract a piece of data from the received data socket buffers.
782 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
787 _enter("{%s,%zu},,%zu,%d",
788 call->type->name, call->offset, count, want_more);
790 ASSERTCMP(call->offset, <=, count);
792 ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
793 buf, count, &call->offset,
794 want_more, &call->abort_code);
795 trace_afs_recv_data(call, count, call->offset, want_more, ret);
796 if (ret == 0 || ret == -EAGAIN)
800 switch (call->state) {
801 case AFS_CALL_AWAIT_REPLY:
802 call->state = AFS_CALL_COMPLETE;
804 case AFS_CALL_AWAIT_REQUEST:
805 call->state = AFS_CALL_REPLYING;
813 if (ret == -ECONNABORTED)
814 call->error = call->type->abort_to_error(call->abort_code);
817 call->state = AFS_CALL_COMPLETE;