diff options
Diffstat (limited to 'net/rxrpc/call_object.c')
| -rw-r--r-- | net/rxrpc/call_object.c | 737 |
1 files changed, 737 insertions, 0 deletions
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c new file mode 100644 index 000000000..6401cdf7a --- /dev/null +++ b/net/rxrpc/call_object.c @@ -0,0 +1,737 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* RxRPC individual remote procedure call handling + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/circ_buf.h> +#include <linux/spinlock_types.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include "ar-internal.h" + +const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = { + [RXRPC_CALL_UNINITIALISED] = "Uninit ", + [RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn", + [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq", + [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl", + [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl", + [RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc", + [RXRPC_CALL_SERVER_SECURING] = "SvSecure", + [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq", + [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq", + [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl", + [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK", + [RXRPC_CALL_COMPLETE] = "Complete", +}; + +const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = { + [RXRPC_CALL_SUCCEEDED] = "Complete", + [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort", + [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort", + [RXRPC_CALL_LOCAL_ERROR] = "LocError", + [RXRPC_CALL_NETWORK_ERROR] = "NetError", +}; + +struct kmem_cache *rxrpc_call_jar; + +static struct semaphore rxrpc_call_limiter = + __SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000); +static struct semaphore rxrpc_kernel_call_limiter = + __SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000); + +static void rxrpc_call_timer_expired(struct timer_list *t) +{ + struct rxrpc_call *call = from_timer(call, t, timer); + + _enter("%d", call->debug_id); + + if (call->state < RXRPC_CALL_COMPLETE) { + trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies); + __rxrpc_queue_call(call); + } else { + rxrpc_put_call(call, rxrpc_call_put); + } +} + +void rxrpc_reduce_call_timer(struct rxrpc_call *call, + unsigned long expire_at, + unsigned long now, + enum rxrpc_timer_trace why) +{ + if (rxrpc_try_get_call(call, rxrpc_call_got_timer)) { + trace_rxrpc_timer(call, why, now); + if (timer_reduce(&call->timer, expire_at)) + rxrpc_put_call(call, rxrpc_call_put_notimer); + } +} + +void rxrpc_delete_call_timer(struct rxrpc_call *call) +{ + if (del_timer_sync(&call->timer)) + rxrpc_put_call(call, rxrpc_call_put_timer); +} + +static struct lock_class_key rxrpc_call_user_mutex_lock_class_key; + +/* + * find an extant server call + * - called in process context with IRQs enabled + */ +struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx, + unsigned long user_call_ID) +{ + struct rxrpc_call *call; + struct rb_node *p; + + _enter("%p,%lx", rx, user_call_ID); + + read_lock(&rx->call_lock); + + p = rx->calls.rb_node; + while (p) { + call = rb_entry(p, struct rxrpc_call, sock_node); + + if (user_call_ID < call->user_call_ID) + p = p->rb_left; + else if (user_call_ID > call->user_call_ID) + p = p->rb_right; + else + goto found_extant_call; + } + + read_unlock(&rx->call_lock); + _leave(" = NULL"); + return NULL; + +found_extant_call: + rxrpc_get_call(call, rxrpc_call_got); + read_unlock(&rx->call_lock); + _leave(" = %p [%d]", call, refcount_read(&call->ref)); + return call; +} + +/* + * allocate a new call + */ +struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp, + unsigned int debug_id) +{ + struct rxrpc_call *call; + struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk)); + + call = kmem_cache_zalloc(rxrpc_call_jar, gfp); + if (!call) + return NULL; + + call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE, + sizeof(struct sk_buff *), + gfp); + if (!call->rxtx_buffer) + goto nomem; + + call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp); + if (!call->rxtx_annotations) + goto nomem_2; + + mutex_init(&call->user_mutex); + + /* Prevent lockdep reporting a deadlock false positive between the afs + * filesystem and sys_sendmsg() via the mmap sem. + */ + if (rx->sk.sk_kern_sock) + lockdep_set_class(&call->user_mutex, + &rxrpc_call_user_mutex_lock_class_key); + + timer_setup(&call->timer, rxrpc_call_timer_expired, 0); + INIT_WORK(&call->processor, &rxrpc_process_call); + INIT_LIST_HEAD(&call->link); + INIT_LIST_HEAD(&call->chan_wait_link); + INIT_LIST_HEAD(&call->accept_link); + INIT_LIST_HEAD(&call->recvmsg_link); + INIT_LIST_HEAD(&call->sock_link); + init_waitqueue_head(&call->waitq); + spin_lock_init(&call->lock); + spin_lock_init(&call->notify_lock); + spin_lock_init(&call->input_lock); + rwlock_init(&call->state_lock); + refcount_set(&call->ref, 1); + call->debug_id = debug_id; + call->tx_total_len = -1; + call->next_rx_timo = 20 * HZ; + call->next_req_timo = 1 * HZ; + + memset(&call->sock_node, 0xed, sizeof(call->sock_node)); + + /* Leave space in the ring to handle a maxed-out jumbo packet */ + call->rx_winsize = rxrpc_rx_window_size; + call->tx_winsize = 16; + call->rx_expect_next = 1; + + call->cong_cwnd = 2; + call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1; + + call->rxnet = rxnet; + call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK; + atomic_inc(&rxnet->nr_calls); + return call; + +nomem_2: + kfree(call->rxtx_buffer); +nomem: + kmem_cache_free(rxrpc_call_jar, call); + return NULL; +} + +/* + * Allocate a new client call. + */ +static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx, + struct sockaddr_rxrpc *srx, + gfp_t gfp, + unsigned int debug_id) +{ + struct rxrpc_call *call; + ktime_t now; + + _enter(""); + + call = rxrpc_alloc_call(rx, gfp, debug_id); + if (!call) + return ERR_PTR(-ENOMEM); + call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; + call->service_id = srx->srx_service; + call->tx_phase = true; + now = ktime_get_real(); + call->acks_latest_ts = now; + call->cong_tstamp = now; + + _leave(" = %p", call); + return call; +} + +/* + * Initiate the call ack/resend/expiry timer. + */ +static void rxrpc_start_call_timer(struct rxrpc_call *call) +{ + unsigned long now = jiffies; + unsigned long j = now + MAX_JIFFY_OFFSET; + + call->ack_at = j; + call->ack_lost_at = j; + call->resend_at = j; + call->ping_at = j; + call->expect_rx_by = j; + call->expect_req_by = j; + call->expect_term_by = j; + call->timer.expires = now; +} + +/* + * Wait for a call slot to become available. + */ +static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp) +{ + struct semaphore *limiter = &rxrpc_call_limiter; + + if (p->kernel) + limiter = &rxrpc_kernel_call_limiter; + if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) { + down(limiter); + return limiter; + } + return down_interruptible(limiter) < 0 ? NULL : limiter; +} + +/* + * Release a call slot. + */ +static void rxrpc_put_call_slot(struct rxrpc_call *call) +{ + struct semaphore *limiter = &rxrpc_call_limiter; + + if (test_bit(RXRPC_CALL_KERNEL, &call->flags)) + limiter = &rxrpc_kernel_call_limiter; + up(limiter); +} + +/* + * Set up a call for the given parameters. + * - Called with the socket lock held, which it must release. + * - If it returns a call, the call's lock will need releasing by the caller. + */ +struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, + struct rxrpc_conn_parameters *cp, + struct sockaddr_rxrpc *srx, + struct rxrpc_call_params *p, + gfp_t gfp, + unsigned int debug_id) + __releases(&rx->sk.sk_lock.slock) + __acquires(&call->user_mutex) +{ + struct rxrpc_call *call, *xcall; + struct rxrpc_net *rxnet; + struct semaphore *limiter; + struct rb_node *parent, **pp; + const void *here = __builtin_return_address(0); + int ret; + + _enter("%p,%lx", rx, p->user_call_ID); + + limiter = rxrpc_get_call_slot(p, gfp); + if (!limiter) { + release_sock(&rx->sk); + return ERR_PTR(-ERESTARTSYS); + } + + call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id); + if (IS_ERR(call)) { + release_sock(&rx->sk); + up(limiter); + _leave(" = %ld", PTR_ERR(call)); + return call; + } + + call->interruptibility = p->interruptibility; + call->tx_total_len = p->tx_total_len; + trace_rxrpc_call(call->debug_id, rxrpc_call_new_client, + refcount_read(&call->ref), + here, (const void *)p->user_call_ID); + if (p->kernel) + __set_bit(RXRPC_CALL_KERNEL, &call->flags); + + /* We need to protect a partially set up call against the user as we + * will be acting outside the socket lock. + */ + mutex_lock(&call->user_mutex); + + /* Publish the call, even though it is incompletely set up as yet */ + write_lock(&rx->call_lock); + + pp = &rx->calls.rb_node; + parent = NULL; + while (*pp) { + parent = *pp; + xcall = rb_entry(parent, struct rxrpc_call, sock_node); + + if (p->user_call_ID < xcall->user_call_ID) + pp = &(*pp)->rb_left; + else if (p->user_call_ID > xcall->user_call_ID) + pp = &(*pp)->rb_right; + else + goto error_dup_user_ID; + } + + rcu_assign_pointer(call->socket, rx); + call->user_call_ID = p->user_call_ID; + __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); + rxrpc_get_call(call, rxrpc_call_got_userid); + rb_link_node(&call->sock_node, parent, pp); + rb_insert_color(&call->sock_node, &rx->calls); + list_add(&call->sock_link, &rx->sock_calls); + + write_unlock(&rx->call_lock); + + rxnet = call->rxnet; + spin_lock_bh(&rxnet->call_lock); + list_add_tail_rcu(&call->link, &rxnet->calls); + spin_unlock_bh(&rxnet->call_lock); + + /* From this point on, the call is protected by its own lock. */ + release_sock(&rx->sk); + + /* Set up or get a connection record and set the protocol parameters, + * including channel number and call ID. + */ + ret = rxrpc_connect_call(rx, call, cp, srx, gfp); + if (ret < 0) + goto error_attached_to_socket; + + trace_rxrpc_call(call->debug_id, rxrpc_call_connected, + refcount_read(&call->ref), here, NULL); + + rxrpc_start_call_timer(call); + + _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); + + _leave(" = %p [new]", call); + return call; + + /* We unexpectedly found the user ID in the list after taking + * the call_lock. This shouldn't happen unless the user races + * with itself and tries to add the same user ID twice at the + * same time in different threads. + */ +error_dup_user_ID: + write_unlock(&rx->call_lock); + release_sock(&rx->sk); + __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, + RX_CALL_DEAD, -EEXIST); + trace_rxrpc_call(call->debug_id, rxrpc_call_error, + refcount_read(&call->ref), here, ERR_PTR(-EEXIST)); + rxrpc_release_call(rx, call); + mutex_unlock(&call->user_mutex); + rxrpc_put_call(call, rxrpc_call_put); + _leave(" = -EEXIST"); + return ERR_PTR(-EEXIST); + + /* We got an error, but the call is attached to the socket and is in + * need of release. However, we might now race with recvmsg() when + * completing the call queues it. Return 0 from sys_sendmsg() and + * leave the error to recvmsg() to deal with. + */ +error_attached_to_socket: + trace_rxrpc_call(call->debug_id, rxrpc_call_error, + refcount_read(&call->ref), here, ERR_PTR(ret)); + set_bit(RXRPC_CALL_DISCONNECTED, &call->flags); + __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, + RX_CALL_DEAD, ret); + _leave(" = c=%08x [err]", call->debug_id); + return call; +} + +/* + * Set up an incoming call. call->conn points to the connection. + * This is called in BH context and isn't allowed to fail. + */ +void rxrpc_incoming_call(struct rxrpc_sock *rx, + struct rxrpc_call *call, + struct sk_buff *skb) +{ + struct rxrpc_connection *conn = call->conn; + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + u32 chan; + + _enter(",%d", call->conn->debug_id); + + rcu_assign_pointer(call->socket, rx); + call->call_id = sp->hdr.callNumber; + call->service_id = sp->hdr.serviceId; + call->cid = sp->hdr.cid; + call->state = RXRPC_CALL_SERVER_SECURING; + call->cong_tstamp = skb->tstamp; + + /* Set the channel for this call. We don't get channel_lock as we're + * only defending against the data_ready handler (which we're called + * from) and the RESPONSE packet parser (which is only really + * interested in call_counter and can cope with a disagreement with the + * call pointer). + */ + chan = sp->hdr.cid & RXRPC_CHANNELMASK; + conn->channels[chan].call_counter = call->call_id; + conn->channels[chan].call_id = call->call_id; + rcu_assign_pointer(conn->channels[chan].call, call); + + spin_lock(&conn->params.peer->lock); + hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets); + spin_unlock(&conn->params.peer->lock); + + _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); + + rxrpc_start_call_timer(call); + _leave(""); +} + +/* + * Queue a call's work processor, getting a ref to pass to the work queue. + */ +bool rxrpc_queue_call(struct rxrpc_call *call) +{ + const void *here = __builtin_return_address(0); + int n; + + if (!__refcount_inc_not_zero(&call->ref, &n)) + return false; + if (rxrpc_queue_work(&call->processor)) + trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1, + here, NULL); + else + rxrpc_put_call(call, rxrpc_call_put_noqueue); + return true; +} + +/* + * Queue a call's work processor, passing the callers ref to the work queue. + */ +bool __rxrpc_queue_call(struct rxrpc_call *call) +{ + const void *here = __builtin_return_address(0); + int n = refcount_read(&call->ref); + ASSERTCMP(n, >=, 1); + if (rxrpc_queue_work(&call->processor)) + trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n, + here, NULL); + else + rxrpc_put_call(call, rxrpc_call_put_noqueue); + return true; +} + +/* + * Note the re-emergence of a call. + */ +void rxrpc_see_call(struct rxrpc_call *call) +{ + const void *here = __builtin_return_address(0); + if (call) { + int n = refcount_read(&call->ref); + + trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n, + here, NULL); + } +} + +bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) +{ + const void *here = __builtin_return_address(0); + int n; + + if (!__refcount_inc_not_zero(&call->ref, &n)) + return false; + trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL); + return true; +} + +/* + * Note the addition of a ref on a call. + */ +void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) +{ + const void *here = __builtin_return_address(0); + int n; + + __refcount_inc(&call->ref, &n); + trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL); +} + +/* + * Clean up the RxTx skb ring. + */ +static void rxrpc_cleanup_ring(struct rxrpc_call *call) +{ + int i; + + for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { + rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned); + call->rxtx_buffer[i] = NULL; + } +} + +/* + * Detach a call from its owning socket. + */ +void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) +{ + const void *here = __builtin_return_address(0); + struct rxrpc_connection *conn = call->conn; + bool put = false; + + _enter("{%d,%d}", call->debug_id, refcount_read(&call->ref)); + + trace_rxrpc_call(call->debug_id, rxrpc_call_release, + refcount_read(&call->ref), + here, (const void *)call->flags); + + ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); + + spin_lock_bh(&call->lock); + if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) + BUG(); + spin_unlock_bh(&call->lock); + + rxrpc_put_call_slot(call); + rxrpc_delete_call_timer(call); + + /* Make sure we don't get any more notifications */ + write_lock_bh(&rx->recvmsg_lock); + + if (!list_empty(&call->recvmsg_link)) { + _debug("unlinking once-pending call %p { e=%lx f=%lx }", + call, call->events, call->flags); + list_del(&call->recvmsg_link); + put = true; + } + + /* list_empty() must return false in rxrpc_notify_socket() */ + call->recvmsg_link.next = NULL; + call->recvmsg_link.prev = NULL; + + write_unlock_bh(&rx->recvmsg_lock); + if (put) + rxrpc_put_call(call, rxrpc_call_put); + + write_lock(&rx->call_lock); + + if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { + rb_erase(&call->sock_node, &rx->calls); + memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); + rxrpc_put_call(call, rxrpc_call_put_userid); + } + + list_del(&call->sock_link); + write_unlock(&rx->call_lock); + + _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); + + if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) + rxrpc_disconnect_call(call); + if (call->security) + call->security->free_call_crypto(call); + _leave(""); +} + +/* + * release all the calls associated with a socket + */ +void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) +{ + struct rxrpc_call *call; + + _enter("%p", rx); + + while (!list_empty(&rx->to_be_accepted)) { + call = list_entry(rx->to_be_accepted.next, + struct rxrpc_call, accept_link); + list_del(&call->accept_link); + rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET); + rxrpc_put_call(call, rxrpc_call_put); + } + + while (!list_empty(&rx->sock_calls)) { + call = list_entry(rx->sock_calls.next, + struct rxrpc_call, sock_link); + rxrpc_get_call(call, rxrpc_call_got); + rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET); + rxrpc_send_abort_packet(call); + rxrpc_release_call(rx, call); + rxrpc_put_call(call, rxrpc_call_put); + } + + _leave(""); +} + +/* + * release a call + */ +void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) +{ + struct rxrpc_net *rxnet = call->rxnet; + const void *here = __builtin_return_address(0); + unsigned int debug_id = call->debug_id; + bool dead; + int n; + + ASSERT(call != NULL); + + dead = __refcount_dec_and_test(&call->ref, &n); + trace_rxrpc_call(debug_id, op, n, here, NULL); + if (dead) { + _debug("call %d dead", call->debug_id); + ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); + + if (!list_empty(&call->link)) { + spin_lock_bh(&rxnet->call_lock); + list_del_init(&call->link); + spin_unlock_bh(&rxnet->call_lock); + } + + rxrpc_cleanup_call(call); + } +} + +/* + * Final call destruction - but must be done in process context. + */ +static void rxrpc_destroy_call(struct work_struct *work) +{ + struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor); + struct rxrpc_net *rxnet = call->rxnet; + + rxrpc_delete_call_timer(call); + + rxrpc_put_connection(call->conn); + rxrpc_put_peer(call->peer); + kfree(call->rxtx_buffer); + kfree(call->rxtx_annotations); + kmem_cache_free(rxrpc_call_jar, call); + if (atomic_dec_and_test(&rxnet->nr_calls)) + wake_up_var(&rxnet->nr_calls); +} + +/* + * Final call destruction under RCU. + */ +static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) +{ + struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); + + if (in_softirq()) { + INIT_WORK(&call->processor, rxrpc_destroy_call); + if (!rxrpc_queue_work(&call->processor)) + BUG(); + } else { + rxrpc_destroy_call(&call->processor); + } +} + +/* + * clean up a call + */ +void rxrpc_cleanup_call(struct rxrpc_call *call) +{ + _net("DESTROY CALL %d", call->debug_id); + + memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); + + ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); + ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); + + rxrpc_cleanup_ring(call); + rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned); + + call_rcu(&call->rcu, rxrpc_rcu_destroy_call); +} + +/* + * Make sure that all calls are gone from a network namespace. To reach this + * point, any open UDP sockets in that namespace must have been closed, so any + * outstanding calls cannot be doing I/O. + */ +void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet) +{ + struct rxrpc_call *call; + + _enter(""); + + if (!list_empty(&rxnet->calls)) { + spin_lock_bh(&rxnet->call_lock); + + while (!list_empty(&rxnet->calls)) { + call = list_entry(rxnet->calls.next, + struct rxrpc_call, link); + _debug("Zapping call %p", call); + + rxrpc_see_call(call); + list_del_init(&call->link); + + pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", + call, refcount_read(&call->ref), + rxrpc_call_states[call->state], + call->flags, call->events); + + spin_unlock_bh(&rxnet->call_lock); + cond_resched(); + spin_lock_bh(&rxnet->call_lock); + } + + spin_unlock_bh(&rxnet->call_lock); + } + + atomic_dec(&rxnet->nr_calls); + wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls)); +} |