![David Howells](/assets/img/avatar_default.png)
All the routines by which rxrpc is accessed from the outside are serialised by means of the socket lock (sendmsg, recvmsg, bind, rxrpc_kernel_begin_call(), ...) and this presents a problem: (1) If a number of calls on the same socket are in the process of connection to the same peer, a maximum of four concurrent live calls are permitted before further calls need to wait for a slot. (2) If a call is waiting for a slot, it is deep inside sendmsg() or rxrpc_kernel_begin_call() and the entry function is holding the socket lock. (3) sendmsg() and recvmsg() or the in-kernel equivalents are prevented from servicing the other calls as they need to take the socket lock to do so. (4) The socket is stuck until a call is aborted and makes its slot available to the waiter. Fix this by: (1) Provide each call with a mutex ('user_mutex') that arbitrates access by the users of rxrpc separately for each specific call. (2) Make rxrpc_sendmsg() and rxrpc_recvmsg() unlock the socket as soon as they've got a call and taken its mutex. Note that I'm returning EWOULDBLOCK from recvmsg() if MSG_DONTWAIT is set but someone else has the lock. Should I instead only return EWOULDBLOCK if there's nothing currently to be done on a socket, and sleep in this particular instance because there is something to be done, but we appear to be blocked by the interrupt handler doing its ping? (3) Make rxrpc_new_client_call() unlock the socket after allocating a new call, locking its user mutex and adding it to the socket's call tree. The call is returned locked so that sendmsg() can add data to it immediately. From the moment the call is in the socket tree, it is subject to access by sendmsg() and recvmsg() - even if it isn't connected yet. (4) Lock new service calls in the UDP data_ready handler (in rxrpc_new_incoming_call()) because they may already be in the socket's tree and the data_ready handler makes them live immediately if a user ID has already been preassigned. Note that the new call is locked before any notifications are sent that it is live, so doing mutex_trylock() *ought* to always succeed. Userspace is prevented from doing sendmsg() on calls that are in a too-early state in rxrpc_do_sendmsg(). (5) Make rxrpc_new_incoming_call() return the call with the user mutex held so that a ping can be scheduled immediately under it. Note that it might be worth moving the ping call into rxrpc_new_incoming_call() and then we can drop the mutex there. (6) Make rxrpc_accept_call() take the lock on the call it is accepting and release the socket after adding the call to the socket's tree. This is slightly tricky as we've dequeued the call by that point and have to requeue it. Note that requeuing emits a trace event. (7) Make rxrpc_kernel_send_data() and rxrpc_kernel_recv_data() take the new mutex immediately and don't bother with the socket mutex at all. This patch has the nice bonus that calls on the same socket are now to some extent parallelisable. Note that we might want to move rxrpc_service_prealloc() calls out from the socket lock and give it its own lock, so that we don't hang progress in other calls because we're waiting for the allocator. We probably also want to avoid calling rxrpc_notify_socket() from within the socket lock (rxrpc_accept_call()). Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.c.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
656 lines
18 KiB
C
656 lines
18 KiB
C
/* incoming call handling
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/net.h>
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#include <linux/skbuff.h>
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#include <linux/errqueue.h>
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#include <linux/udp.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/icmp.h>
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#include <linux/gfp.h>
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#include <linux/circ_buf.h>
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#include <net/sock.h>
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#include <net/af_rxrpc.h>
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#include <net/ip.h>
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#include "ar-internal.h"
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/*
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* Preallocate a single service call, connection and peer and, if possible,
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* give them a user ID and attach the user's side of the ID to them.
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*/
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static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
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struct rxrpc_backlog *b,
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rxrpc_notify_rx_t notify_rx,
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rxrpc_user_attach_call_t user_attach_call,
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unsigned long user_call_ID, gfp_t gfp)
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{
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const void *here = __builtin_return_address(0);
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struct rxrpc_call *call;
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int max, tmp;
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unsigned int size = RXRPC_BACKLOG_MAX;
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unsigned int head, tail, call_head, call_tail;
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max = rx->sk.sk_max_ack_backlog;
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tmp = rx->sk.sk_ack_backlog;
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if (tmp >= max) {
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_leave(" = -ENOBUFS [full %u]", max);
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return -ENOBUFS;
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}
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max -= tmp;
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/* We don't need more conns and peers than we have calls, but on the
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* other hand, we shouldn't ever use more peers than conns or conns
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* than calls.
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*/
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call_head = b->call_backlog_head;
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call_tail = READ_ONCE(b->call_backlog_tail);
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tmp = CIRC_CNT(call_head, call_tail, size);
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if (tmp >= max) {
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_leave(" = -ENOBUFS [enough %u]", tmp);
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return -ENOBUFS;
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}
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max = tmp + 1;
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head = b->peer_backlog_head;
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tail = READ_ONCE(b->peer_backlog_tail);
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if (CIRC_CNT(head, tail, size) < max) {
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struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
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if (!peer)
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return -ENOMEM;
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b->peer_backlog[head] = peer;
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smp_store_release(&b->peer_backlog_head,
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(head + 1) & (size - 1));
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}
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head = b->conn_backlog_head;
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tail = READ_ONCE(b->conn_backlog_tail);
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if (CIRC_CNT(head, tail, size) < max) {
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struct rxrpc_connection *conn;
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conn = rxrpc_prealloc_service_connection(gfp);
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if (!conn)
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return -ENOMEM;
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b->conn_backlog[head] = conn;
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smp_store_release(&b->conn_backlog_head,
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(head + 1) & (size - 1));
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trace_rxrpc_conn(conn, rxrpc_conn_new_service,
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atomic_read(&conn->usage), here);
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}
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/* Now it gets complicated, because calls get registered with the
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* socket here, particularly if a user ID is preassigned by the user.
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*/
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call = rxrpc_alloc_call(gfp);
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if (!call)
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return -ENOMEM;
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call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
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call->state = RXRPC_CALL_SERVER_PREALLOC;
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trace_rxrpc_call(call, rxrpc_call_new_service,
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atomic_read(&call->usage),
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here, (const void *)user_call_ID);
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write_lock(&rx->call_lock);
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if (user_attach_call) {
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struct rxrpc_call *xcall;
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struct rb_node *parent, **pp;
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/* Check the user ID isn't already in use */
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pp = &rx->calls.rb_node;
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parent = NULL;
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while (*pp) {
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parent = *pp;
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xcall = rb_entry(parent, struct rxrpc_call, sock_node);
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if (user_call_ID < call->user_call_ID)
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pp = &(*pp)->rb_left;
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else if (user_call_ID > call->user_call_ID)
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pp = &(*pp)->rb_right;
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else
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goto id_in_use;
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}
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call->user_call_ID = user_call_ID;
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call->notify_rx = notify_rx;
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rxrpc_get_call(call, rxrpc_call_got_kernel);
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user_attach_call(call, user_call_ID);
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rxrpc_get_call(call, rxrpc_call_got_userid);
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rb_link_node(&call->sock_node, parent, pp);
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rb_insert_color(&call->sock_node, &rx->calls);
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set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
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}
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list_add(&call->sock_link, &rx->sock_calls);
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write_unlock(&rx->call_lock);
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write_lock(&rxrpc_call_lock);
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list_add_tail(&call->link, &rxrpc_calls);
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write_unlock(&rxrpc_call_lock);
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b->call_backlog[call_head] = call;
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smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
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_leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
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return 0;
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id_in_use:
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write_unlock(&rx->call_lock);
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rxrpc_cleanup_call(call);
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_leave(" = -EBADSLT");
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return -EBADSLT;
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}
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/*
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* Preallocate sufficient service connections, calls and peers to cover the
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* entire backlog of a socket. When a new call comes in, if we don't have
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* sufficient of each available, the call gets rejected as busy or ignored.
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*
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* The backlog is replenished when a connection is accepted or rejected.
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*/
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int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
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{
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struct rxrpc_backlog *b = rx->backlog;
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if (!b) {
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b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
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if (!b)
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return -ENOMEM;
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rx->backlog = b;
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}
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if (rx->discard_new_call)
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return 0;
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while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp) == 0)
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;
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return 0;
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}
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/*
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* Discard the preallocation on a service.
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*/
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void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
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{
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struct rxrpc_backlog *b = rx->backlog;
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unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
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if (!b)
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return;
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rx->backlog = NULL;
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/* Make sure that there aren't any incoming calls in progress before we
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* clear the preallocation buffers.
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*/
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spin_lock_bh(&rx->incoming_lock);
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spin_unlock_bh(&rx->incoming_lock);
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head = b->peer_backlog_head;
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tail = b->peer_backlog_tail;
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while (CIRC_CNT(head, tail, size) > 0) {
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struct rxrpc_peer *peer = b->peer_backlog[tail];
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kfree(peer);
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tail = (tail + 1) & (size - 1);
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}
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head = b->conn_backlog_head;
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tail = b->conn_backlog_tail;
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while (CIRC_CNT(head, tail, size) > 0) {
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struct rxrpc_connection *conn = b->conn_backlog[tail];
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write_lock(&rxrpc_connection_lock);
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list_del(&conn->link);
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list_del(&conn->proc_link);
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write_unlock(&rxrpc_connection_lock);
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kfree(conn);
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tail = (tail + 1) & (size - 1);
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}
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head = b->call_backlog_head;
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tail = b->call_backlog_tail;
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while (CIRC_CNT(head, tail, size) > 0) {
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struct rxrpc_call *call = b->call_backlog[tail];
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if (rx->discard_new_call) {
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_debug("discard %lx", call->user_call_ID);
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rx->discard_new_call(call, call->user_call_ID);
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rxrpc_put_call(call, rxrpc_call_put_kernel);
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}
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rxrpc_call_completed(call);
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rxrpc_release_call(rx, call);
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rxrpc_put_call(call, rxrpc_call_put);
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tail = (tail + 1) & (size - 1);
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}
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kfree(b);
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}
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/*
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* Allocate a new incoming call from the prealloc pool, along with a connection
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* and a peer as necessary.
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*/
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static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
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struct rxrpc_local *local,
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struct rxrpc_connection *conn,
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struct sk_buff *skb)
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{
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struct rxrpc_backlog *b = rx->backlog;
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struct rxrpc_peer *peer, *xpeer;
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struct rxrpc_call *call;
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unsigned short call_head, conn_head, peer_head;
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unsigned short call_tail, conn_tail, peer_tail;
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unsigned short call_count, conn_count;
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/* #calls >= #conns >= #peers must hold true. */
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call_head = smp_load_acquire(&b->call_backlog_head);
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call_tail = b->call_backlog_tail;
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call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
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conn_head = smp_load_acquire(&b->conn_backlog_head);
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conn_tail = b->conn_backlog_tail;
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conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
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ASSERTCMP(conn_count, >=, call_count);
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peer_head = smp_load_acquire(&b->peer_backlog_head);
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peer_tail = b->peer_backlog_tail;
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ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
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conn_count);
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if (call_count == 0)
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return NULL;
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if (!conn) {
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/* No connection. We're going to need a peer to start off
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* with. If one doesn't yet exist, use a spare from the
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* preallocation set. We dump the address into the spare in
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* anticipation - and to save on stack space.
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*/
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xpeer = b->peer_backlog[peer_tail];
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if (rxrpc_extract_addr_from_skb(&xpeer->srx, skb) < 0)
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return NULL;
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peer = rxrpc_lookup_incoming_peer(local, xpeer);
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if (peer == xpeer) {
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b->peer_backlog[peer_tail] = NULL;
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smp_store_release(&b->peer_backlog_tail,
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(peer_tail + 1) &
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(RXRPC_BACKLOG_MAX - 1));
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}
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/* Now allocate and set up the connection */
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conn = b->conn_backlog[conn_tail];
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b->conn_backlog[conn_tail] = NULL;
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smp_store_release(&b->conn_backlog_tail,
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(conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
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rxrpc_get_local(local);
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conn->params.local = local;
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conn->params.peer = peer;
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rxrpc_see_connection(conn);
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rxrpc_new_incoming_connection(conn, skb);
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} else {
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rxrpc_get_connection(conn);
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}
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/* And now we can allocate and set up a new call */
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call = b->call_backlog[call_tail];
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b->call_backlog[call_tail] = NULL;
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smp_store_release(&b->call_backlog_tail,
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(call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
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rxrpc_see_call(call);
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call->conn = conn;
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call->peer = rxrpc_get_peer(conn->params.peer);
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return call;
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}
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/*
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* Set up a new incoming call. Called in BH context with the RCU read lock
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* held.
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*
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* If this is for a kernel service, when we allocate the call, it will have
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* three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
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* retainer ref obtained from the backlog buffer. Prealloc calls for userspace
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* services only have the ref from the backlog buffer. We want to pass this
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* ref to non-BH context to dispose of.
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*
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* If we want to report an error, we mark the skb with the packet type and
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* abort code and return NULL.
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*
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* The call is returned with the user access mutex held.
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*/
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struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
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struct rxrpc_connection *conn,
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struct sk_buff *skb)
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{
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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struct rxrpc_sock *rx;
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struct rxrpc_call *call;
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u16 service_id = sp->hdr.serviceId;
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_enter("");
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/* Get the socket providing the service */
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rx = rcu_dereference(local->service);
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if (rx && service_id == rx->srx.srx_service)
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goto found_service;
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trace_rxrpc_abort("INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
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RX_INVALID_OPERATION, EOPNOTSUPP);
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skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
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skb->priority = RX_INVALID_OPERATION;
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_leave(" = NULL [service]");
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return NULL;
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found_service:
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spin_lock(&rx->incoming_lock);
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if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
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rx->sk.sk_state == RXRPC_CLOSE) {
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trace_rxrpc_abort("CLS", sp->hdr.cid, sp->hdr.callNumber,
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sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
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skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
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skb->priority = RX_INVALID_OPERATION;
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_leave(" = NULL [close]");
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call = NULL;
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goto out;
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}
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call = rxrpc_alloc_incoming_call(rx, local, conn, skb);
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if (!call) {
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skb->mark = RXRPC_SKB_MARK_BUSY;
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_leave(" = NULL [busy]");
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call = NULL;
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goto out;
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}
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trace_rxrpc_receive(call, rxrpc_receive_incoming,
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sp->hdr.serial, sp->hdr.seq);
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/* Lock the call to prevent rxrpc_kernel_send/recv_data() and
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* sendmsg()/recvmsg() inconveniently stealing the mutex once the
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* notification is generated.
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*
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* The BUG should never happen because the kernel should be well
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* behaved enough not to access the call before the first notification
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* event and userspace is prevented from doing so until the state is
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* appropriate.
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*/
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if (!mutex_trylock(&call->user_mutex))
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BUG();
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/* Make the call live. */
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rxrpc_incoming_call(rx, call, skb);
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conn = call->conn;
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if (rx->notify_new_call)
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rx->notify_new_call(&rx->sk, call, call->user_call_ID);
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else
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sk_acceptq_added(&rx->sk);
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spin_lock(&conn->state_lock);
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switch (conn->state) {
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case RXRPC_CONN_SERVICE_UNSECURED:
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conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
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set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
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rxrpc_queue_conn(call->conn);
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break;
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case RXRPC_CONN_SERVICE:
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write_lock(&call->state_lock);
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if (rx->discard_new_call)
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call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
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else
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call->state = RXRPC_CALL_SERVER_ACCEPTING;
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write_unlock(&call->state_lock);
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break;
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case RXRPC_CONN_REMOTELY_ABORTED:
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rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
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conn->remote_abort, ECONNABORTED);
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break;
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case RXRPC_CONN_LOCALLY_ABORTED:
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rxrpc_abort_call("CON", call, sp->hdr.seq,
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conn->local_abort, ECONNABORTED);
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break;
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default:
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BUG();
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}
|
|
spin_unlock(&conn->state_lock);
|
|
|
|
if (call->state == RXRPC_CALL_SERVER_ACCEPTING)
|
|
rxrpc_notify_socket(call);
|
|
|
|
/* We have to discard the prealloc queue's ref here and rely on a
|
|
* combination of the RCU read lock and refs held either by the socket
|
|
* (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel
|
|
* service to prevent the call from being deallocated too early.
|
|
*/
|
|
rxrpc_put_call(call, rxrpc_call_put);
|
|
|
|
_leave(" = %p{%d}", call, call->debug_id);
|
|
out:
|
|
spin_unlock(&rx->incoming_lock);
|
|
return call;
|
|
}
|
|
|
|
/*
|
|
* handle acceptance of a call by userspace
|
|
* - assign the user call ID to the call at the front of the queue
|
|
* - called with the socket locked.
|
|
*/
|
|
struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
|
|
unsigned long user_call_ID,
|
|
rxrpc_notify_rx_t notify_rx)
|
|
__releases(&rx->sk.sk_lock.slock)
|
|
{
|
|
struct rxrpc_call *call;
|
|
struct rb_node *parent, **pp;
|
|
int ret;
|
|
|
|
_enter(",%lx", user_call_ID);
|
|
|
|
ASSERT(!irqs_disabled());
|
|
|
|
write_lock(&rx->call_lock);
|
|
|
|
if (list_empty(&rx->to_be_accepted)) {
|
|
write_unlock(&rx->call_lock);
|
|
release_sock(&rx->sk);
|
|
kleave(" = -ENODATA [empty]");
|
|
return ERR_PTR(-ENODATA);
|
|
}
|
|
|
|
/* check the user ID isn't already in use */
|
|
pp = &rx->calls.rb_node;
|
|
parent = NULL;
|
|
while (*pp) {
|
|
parent = *pp;
|
|
call = rb_entry(parent, struct rxrpc_call, sock_node);
|
|
|
|
if (user_call_ID < call->user_call_ID)
|
|
pp = &(*pp)->rb_left;
|
|
else if (user_call_ID > call->user_call_ID)
|
|
pp = &(*pp)->rb_right;
|
|
else
|
|
goto id_in_use;
|
|
}
|
|
|
|
/* Dequeue the first call and check it's still valid. We gain
|
|
* responsibility for the queue's reference.
|
|
*/
|
|
call = list_entry(rx->to_be_accepted.next,
|
|
struct rxrpc_call, accept_link);
|
|
write_unlock(&rx->call_lock);
|
|
|
|
/* We need to gain the mutex from the interrupt handler without
|
|
* upsetting lockdep, so we have to release it there and take it here.
|
|
* We are, however, still holding the socket lock, so other accepts
|
|
* must wait for us and no one can add the user ID behind our backs.
|
|
*/
|
|
if (mutex_lock_interruptible(&call->user_mutex) < 0) {
|
|
release_sock(&rx->sk);
|
|
kleave(" = -ERESTARTSYS");
|
|
return ERR_PTR(-ERESTARTSYS);
|
|
}
|
|
|
|
write_lock(&rx->call_lock);
|
|
list_del_init(&call->accept_link);
|
|
sk_acceptq_removed(&rx->sk);
|
|
rxrpc_see_call(call);
|
|
|
|
/* Find the user ID insertion point. */
|
|
pp = &rx->calls.rb_node;
|
|
parent = NULL;
|
|
while (*pp) {
|
|
parent = *pp;
|
|
call = rb_entry(parent, struct rxrpc_call, sock_node);
|
|
|
|
if (user_call_ID < call->user_call_ID)
|
|
pp = &(*pp)->rb_left;
|
|
else if (user_call_ID > call->user_call_ID)
|
|
pp = &(*pp)->rb_right;
|
|
else
|
|
BUG();
|
|
}
|
|
|
|
write_lock_bh(&call->state_lock);
|
|
switch (call->state) {
|
|
case RXRPC_CALL_SERVER_ACCEPTING:
|
|
call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
|
|
break;
|
|
case RXRPC_CALL_COMPLETE:
|
|
ret = call->error;
|
|
goto out_release;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
/* formalise the acceptance */
|
|
call->notify_rx = notify_rx;
|
|
call->user_call_ID = user_call_ID;
|
|
rxrpc_get_call(call, rxrpc_call_got_userid);
|
|
rb_link_node(&call->sock_node, parent, pp);
|
|
rb_insert_color(&call->sock_node, &rx->calls);
|
|
if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
|
|
BUG();
|
|
|
|
write_unlock_bh(&call->state_lock);
|
|
write_unlock(&rx->call_lock);
|
|
rxrpc_notify_socket(call);
|
|
rxrpc_service_prealloc(rx, GFP_KERNEL);
|
|
release_sock(&rx->sk);
|
|
_leave(" = %p{%d}", call, call->debug_id);
|
|
return call;
|
|
|
|
out_release:
|
|
_debug("release %p", call);
|
|
write_unlock_bh(&call->state_lock);
|
|
write_unlock(&rx->call_lock);
|
|
rxrpc_release_call(rx, call);
|
|
rxrpc_put_call(call, rxrpc_call_put);
|
|
goto out;
|
|
|
|
id_in_use:
|
|
ret = -EBADSLT;
|
|
write_unlock(&rx->call_lock);
|
|
out:
|
|
rxrpc_service_prealloc(rx, GFP_KERNEL);
|
|
release_sock(&rx->sk);
|
|
_leave(" = %d", ret);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
/*
|
|
* Handle rejection of a call by userspace
|
|
* - reject the call at the front of the queue
|
|
*/
|
|
int rxrpc_reject_call(struct rxrpc_sock *rx)
|
|
{
|
|
struct rxrpc_call *call;
|
|
bool abort = false;
|
|
int ret;
|
|
|
|
_enter("");
|
|
|
|
ASSERT(!irqs_disabled());
|
|
|
|
write_lock(&rx->call_lock);
|
|
|
|
if (list_empty(&rx->to_be_accepted)) {
|
|
write_unlock(&rx->call_lock);
|
|
return -ENODATA;
|
|
}
|
|
|
|
/* Dequeue the first call and check it's still valid. We gain
|
|
* responsibility for the queue's reference.
|
|
*/
|
|
call = list_entry(rx->to_be_accepted.next,
|
|
struct rxrpc_call, accept_link);
|
|
list_del_init(&call->accept_link);
|
|
sk_acceptq_removed(&rx->sk);
|
|
rxrpc_see_call(call);
|
|
|
|
write_lock_bh(&call->state_lock);
|
|
switch (call->state) {
|
|
case RXRPC_CALL_SERVER_ACCEPTING:
|
|
__rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, ECONNABORTED);
|
|
abort = true;
|
|
/* fall through */
|
|
case RXRPC_CALL_COMPLETE:
|
|
ret = call->error;
|
|
goto out_discard;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
out_discard:
|
|
write_unlock_bh(&call->state_lock);
|
|
write_unlock(&rx->call_lock);
|
|
if (abort) {
|
|
rxrpc_send_abort_packet(call);
|
|
rxrpc_release_call(rx, call);
|
|
rxrpc_put_call(call, rxrpc_call_put);
|
|
}
|
|
rxrpc_service_prealloc(rx, GFP_KERNEL);
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
|
|
* @sock: The socket on which to preallocate
|
|
* @notify_rx: Event notification function for the call
|
|
* @user_attach_call: Func to attach call to user_call_ID
|
|
* @user_call_ID: The tag to attach to the preallocated call
|
|
* @gfp: The allocation conditions.
|
|
*
|
|
* Charge up the socket with preallocated calls, each with a user ID. A
|
|
* function should be provided to effect the attachment from the user's side.
|
|
* The user is given a ref to hold on the call.
|
|
*
|
|
* Note that the call may be come connected before this function returns.
|
|
*/
|
|
int rxrpc_kernel_charge_accept(struct socket *sock,
|
|
rxrpc_notify_rx_t notify_rx,
|
|
rxrpc_user_attach_call_t user_attach_call,
|
|
unsigned long user_call_ID, gfp_t gfp)
|
|
{
|
|
struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
|
|
struct rxrpc_backlog *b = rx->backlog;
|
|
|
|
if (sock->sk->sk_state == RXRPC_CLOSE)
|
|
return -ESHUTDOWN;
|
|
|
|
return rxrpc_service_prealloc_one(rx, b, notify_rx,
|
|
user_attach_call, user_call_ID,
|
|
gfp);
|
|
}
|
|
EXPORT_SYMBOL(rxrpc_kernel_charge_accept);
|