iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
a1399f8bb0
linux/net/rxrpc/call_object.c
David Howells a1399f8bb0 rxrpc: Call channels should have separate call number spaces 
Each channel on a connection has a separate, independent number space from
which to allocate callNumber values.  It is entirely possible, for example,
to have a connection with four active calls, each with call number 1.

Note that the callNumber values for any particular channel don't have to
start at 1, but they are supposed to increment monotonically for that
channel from a client's perspective and may not be reused once the call
number is transmitted (until the epoch cycles all the way back round).

Currently, however, call numbers are allocated on a per-connection basis
and, further, are held in an rb-tree.  The rb-tree is redundant as the four
channel pointers in the rxrpc_connection struct are entirely capable of
pointing to all the calls currently in progress on a connection.

To this end, make the following changes:

 (1) Handle call number allocation independently per channel.

 (2) Get rid of the conn->calls rb-tree.  This is overkill as a connection
     may have a maximum of four calls in progress at any one time.  Use the
     pointers in the channels[] array instead, indexed by the channel
     number from the packet.

 (3) For each channel, save the result of the last call that was in
     progress on that channel in conn->channels[] so that the final ACK or
     ABORT packet can be replayed if necessary.  Any call earlier than that
     is just ignored.  If we've seen the next call number in a packet, the
     last one is most definitely defunct.

 (4) When generating a RESPONSE packet for a connection, the call number
     counter for each channel must be included in it.

 (5) When parsing a RESPONSE packet for a connection, the call number
     counters contained therein should be used to set the minimum expected
     call numbers on each channel.

To do in future commits:

 (1) Replay terminal packets based on the last call stored in
     conn->channels[].

 (2) Connections should be retired before the callNumber space on any
     channel runs out.

 (3) A server is expected to disregard or reject any new incoming call that
     has a call number less than the current call number counter.  The call
     number counter for that channel must be advanced to the new call
     number.

     Note that the server cannot just require that the next call that it
     sees on a channel be exactly the call number counter + 1 because then
     there's a scenario that could cause a problem: The client transmits a
     packet to initiate a connection, the network goes out, the server
     sends an ACK (which gets lost), the client sends an ABORT (which also
     gets lost); the network then reconnects, the client then reuses the
     call number for the next call (it doesn't know the server already saw
     the call number), but the server thinks it already has the first
     packet of this call (it doesn't know that the client doesn't know that
     it saw the call number the first time).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:52 +01:00

978 lines
25 KiB
C
Raw Blame History

/* RxRPC individual remote procedure call handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <linux/hashtable.h>
#include <linux/spinlock_types.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Maximum lifetime of a call (in jiffies).
*/
unsigned int rxrpc_max_call_lifetime = 60 * HZ;
/*
* Time till dead call expires after last use (in jiffies).
*/
unsigned int rxrpc_dead_call_expiry = 2 * HZ;
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_CLIENT_FINAL_ACK] = "ClFnlACK",
[RXRPC_CALL_SERVER_SECURING] = "SvSecure",
[RXRPC_CALL_SERVER_ACCEPTING] = "SvAccept",
[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",
[RXRPC_CALL_SERVER_BUSY] = "SvBusy ",
[RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort",
[RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort",
[RXRPC_CALL_NETWORK_ERROR] = "NetError",
[RXRPC_CALL_DEAD] = "Dead ",
};
struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);
static void rxrpc_destroy_call(struct work_struct *work);
static void rxrpc_call_life_expired(unsigned long _call);
static void rxrpc_dead_call_expired(unsigned long _call);
static void rxrpc_ack_time_expired(unsigned long _call);
static void rxrpc_resend_time_expired(unsigned long _call);
static DEFINE_SPINLOCK(rxrpc_call_hash_lock);
static DEFINE_HASHTABLE(rxrpc_call_hash, 10);
/*
* Hash function for rxrpc_call_hash
*/
static unsigned long rxrpc_call_hashfunc(
u8 in_clientflag,
u32 cid,
u32 call_id,
u32 epoch,
u16 service_id,
sa_family_t family,
void *localptr,
unsigned int addr_size,
const u8 *peer_addr)
{
const u16 *p;
unsigned int i;
unsigned long key;
_enter("");
key = (unsigned long)localptr;
/* We just want to add up the __be32 values, so forcing the
* cast should be okay.
*/
key += epoch;
key += service_id;
key += call_id;
key += (cid & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT;
key += cid & RXRPC_CHANNELMASK;
key += in_clientflag;
key += family;
/* Step through the peer address in 16-bit portions for speed */
for (i = 0, p = (const u16 *)peer_addr; i < addr_size >> 1; i++, p++)
key += *p;
_leave(" key = 0x%lx", key);
return key;
}
/*
* Add a call to the hashtable
*/
static void rxrpc_call_hash_add(struct rxrpc_call *call)
{
unsigned long key;
unsigned int addr_size = 0;
_enter("");
switch (call->family) {
case AF_INET:
addr_size = sizeof(call->peer_ip.ipv4_addr);
break;
case AF_INET6:
addr_size = sizeof(call->peer_ip.ipv6_addr);
break;
default:
break;
}
key = rxrpc_call_hashfunc(call->in_clientflag, call->cid,
call->call_id, call->epoch,
call->service_id, call->family,
call->conn->params.local, addr_size,
call->peer_ip.ipv6_addr);
/* Store the full key in the call */
call->hash_key = key;
spin_lock(&rxrpc_call_hash_lock);
hash_add_rcu(rxrpc_call_hash, &call->hash_node, key);
spin_unlock(&rxrpc_call_hash_lock);
_leave("");
}
/*
* Remove a call from the hashtable
*/
static void rxrpc_call_hash_del(struct rxrpc_call *call)
{
_enter("");
spin_lock(&rxrpc_call_hash_lock);
hash_del_rcu(&call->hash_node);
spin_unlock(&rxrpc_call_hash_lock);
_leave("");
}
/*
* Find a call in the hashtable and return it, or NULL if it
* isn't there.
*/
struct rxrpc_call *rxrpc_find_call_hash(
struct rxrpc_host_header *hdr,
void *localptr,
sa_family_t family,
const void *peer_addr)
{
unsigned long key;
unsigned int addr_size = 0;
struct rxrpc_call *call = NULL;
struct rxrpc_call *ret = NULL;
u8 in_clientflag = hdr->flags & RXRPC_CLIENT_INITIATED;
_enter("");
switch (family) {
case AF_INET:
addr_size = sizeof(call->peer_ip.ipv4_addr);
break;
case AF_INET6:
addr_size = sizeof(call->peer_ip.ipv6_addr);
break;
default:
break;
}
key = rxrpc_call_hashfunc(in_clientflag, hdr->cid, hdr->callNumber,
hdr->epoch, hdr->serviceId,
family, localptr, addr_size,
peer_addr);
hash_for_each_possible_rcu(rxrpc_call_hash, call, hash_node, key) {
if (call->hash_key == key &&
call->call_id == hdr->callNumber &&
call->cid == hdr->cid &&
call->in_clientflag == in_clientflag &&
call->service_id == hdr->serviceId &&
call->family == family &&
call->local == localptr &&
memcmp(call->peer_ip.ipv6_addr, peer_addr,
addr_size) == 0 &&
call->epoch == hdr->epoch) {
ret = call;
break;
}
}
_leave(" = %p", ret);
return ret;
}
/*
* 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);
read_unlock(&rx->call_lock);
_leave(" = %p [%d]", call, atomic_read(&call->usage));
return call;
}
/*
* allocate a new call
*/
static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
{
struct rxrpc_call *call;
call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
if (!call)
return NULL;
call->acks_winsz = 16;
call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long),
gfp);
if (!call->acks_window) {
kmem_cache_free(rxrpc_call_jar, call);
return NULL;
}
setup_timer(&call->lifetimer, &rxrpc_call_life_expired,
(unsigned long) call);
setup_timer(&call->deadspan, &rxrpc_dead_call_expired,
(unsigned long) call);
setup_timer(&call->ack_timer, &rxrpc_ack_time_expired,
(unsigned long) call);
setup_timer(&call->resend_timer, &rxrpc_resend_time_expired,
(unsigned long) call);
INIT_WORK(&call->destroyer, &rxrpc_destroy_call);
INIT_WORK(&call->processor, &rxrpc_process_call);
INIT_LIST_HEAD(&call->link);
INIT_LIST_HEAD(&call->accept_link);
skb_queue_head_init(&call->rx_queue);
skb_queue_head_init(&call->rx_oos_queue);
init_waitqueue_head(&call->tx_waitq);
spin_lock_init(&call->lock);
rwlock_init(&call->state_lock);
atomic_set(&call->usage, 1);
call->debug_id = atomic_inc_return(&rxrpc_debug_id);
memset(&call->sock_node, 0xed, sizeof(call->sock_node));
call->rx_data_expect = 1;
call->rx_data_eaten = 0;
call->rx_first_oos = 0;
call->ackr_win_top = call->rx_data_eaten + 1 + rxrpc_rx_window_size;
call->creation_jif = jiffies;
return call;
}
/*
* Allocate a new client call.
*/
static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
struct sockaddr_rxrpc *srx,
gfp_t gfp)
{
struct rxrpc_call *call;
_enter("");
ASSERT(rx->local != NULL);
call = rxrpc_alloc_call(gfp);
if (!call)
return ERR_PTR(-ENOMEM);
call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
sock_hold(&rx->sk);
call->socket = rx;
call->rx_data_post = 1;
/* Record copies of information for hashtable lookup */
call->family = rx->family;
call->local = rx->local;
switch (call->family) {
case AF_INET:
call->peer_ip.ipv4_addr = srx->transport.sin.sin_addr.s_addr;
break;
case AF_INET6:
memcpy(call->peer_ip.ipv6_addr,
srx->transport.sin6.sin6_addr.in6_u.u6_addr8,
sizeof(call->peer_ip.ipv6_addr));
break;
}
call->service_id = srx->srx_service;
call->in_clientflag = 0;
_leave(" = %p", call);
return call;
}
/*
* Begin client call.
*/
static int rxrpc_begin_client_call(struct rxrpc_call *call,
struct rxrpc_conn_parameters *cp,
struct sockaddr_rxrpc *srx,
gfp_t gfp)
{
int ret;
/* Set up or get a connection record and set the protocol parameters,
* including channel number and call ID.
*/
ret = rxrpc_connect_call(call, cp, srx, gfp);
if (ret < 0)
return ret;
call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
/* Add the new call to the hashtable */
rxrpc_call_hash_add(call);
spin_lock(&call->conn->params.peer->lock);
hlist_add_head(&call->error_link, &call->conn->params.peer->error_targets);
spin_unlock(&call->conn->params.peer->lock);
call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
add_timer(&call->lifetimer);
return 0;
}
/*
* set up a call for the given data
* - called in process context with IRQs enabled
*/
struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
struct rxrpc_conn_parameters *cp,
struct sockaddr_rxrpc *srx,
unsigned long user_call_ID,
gfp_t gfp)
{
struct rxrpc_call *call, *xcall;
struct rb_node *parent, **pp;
int ret;
_enter("%p,%lx", rx, user_call_ID);
call = rxrpc_alloc_client_call(rx, srx, gfp);
if (IS_ERR(call)) {
_leave(" = %ld", PTR_ERR(call));
return call;
}
/* Publish the call, even though it is incompletely set up as yet */
call->user_call_ID = user_call_ID;
__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
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 (user_call_ID < xcall->user_call_ID)
pp = &(*pp)->rb_left;
else if (user_call_ID > xcall->user_call_ID)
pp = &(*pp)->rb_right;
else
goto found_user_ID_now_present;
}
rxrpc_get_call(call);
rb_link_node(&call->sock_node, parent, pp);
rb_insert_color(&call->sock_node, &rx->calls);
write_unlock(&rx->call_lock);
write_lock_bh(&rxrpc_call_lock);
list_add_tail(&call->link, &rxrpc_calls);
write_unlock_bh(&rxrpc_call_lock);
ret = rxrpc_begin_client_call(call, cp, srx, gfp);
if (ret < 0)
goto error;
_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
_leave(" = %p [new]", call);
return call;
error:
write_lock(&rx->call_lock);
rb_erase(&call->sock_node, &rx->calls);
write_unlock(&rx->call_lock);
rxrpc_put_call(call);
write_lock_bh(&rxrpc_call_lock);
list_del_init(&call->link);
write_unlock_bh(&rxrpc_call_lock);
call->state = RXRPC_CALL_DEAD;
rxrpc_put_call(call);
_leave(" = %d", ret);
return ERR_PTR(ret);
/* 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.
*/
found_user_ID_now_present:
write_unlock(&rx->call_lock);
call->state = RXRPC_CALL_DEAD;
rxrpc_put_call(call);
_leave(" = -EEXIST [%p]", call);
return ERR_PTR(-EEXIST);
}
/*
* set up an incoming call
* - called in process context with IRQs enabled
*/
struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
struct rxrpc_connection *conn,
struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_call *call, *candidate;
u32 call_id, chan;
_enter(",%d", conn->debug_id);
ASSERT(rx != NULL);
candidate = rxrpc_alloc_call(GFP_NOIO);
if (!candidate)
return ERR_PTR(-EBUSY);
chan = sp->hdr.cid & RXRPC_CHANNELMASK;
candidate->socket = rx;
candidate->conn = conn;
candidate->cid = sp->hdr.cid;
candidate->call_id = sp->hdr.callNumber;
candidate->channel = chan;
candidate->rx_data_post = 0;
candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
if (conn->security_ix > 0)
candidate->state = RXRPC_CALL_SERVER_SECURING;
spin_lock(&conn->channel_lock);
/* set the channel for this call */
call = rcu_dereference_protected(conn->channels[chan].call,
lockdep_is_held(&conn->channel_lock));
_debug("channel[%u] is %p", candidate->channel, call);
if (call && call->call_id == sp->hdr.callNumber) {
/* already set; must've been a duplicate packet */
_debug("extant call [%d]", call->state);
ASSERTCMP(call->conn, ==, conn);
read_lock(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_LOCALLY_ABORTED:
if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
rxrpc_queue_call(call);
case RXRPC_CALL_REMOTELY_ABORTED:
read_unlock(&call->state_lock);
goto aborted_call;
default:
rxrpc_get_call(call);
read_unlock(&call->state_lock);
goto extant_call;
}
}
if (call) {
/* it seems the channel is still in use from the previous call
* - ditch the old binding if its call is now complete */
_debug("CALL: %u { %s }",
call->debug_id, rxrpc_call_states[call->state]);
if (call->state >= RXRPC_CALL_COMPLETE) {
__rxrpc_disconnect_call(call);
} else {
spin_unlock(&conn->channel_lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = -EBUSY");
return ERR_PTR(-EBUSY);
}
}
/* check the call number isn't duplicate */
_debug("check dup");
call_id = sp->hdr.callNumber;
/* We just ignore calls prior to the current call ID. Terminated calls
* are handled via the connection.
*/
if (call_id <= conn->channels[chan].call_counter)
goto old_call; /* TODO: Just drop packet */
/* make the call available */
_debug("new call");
call = candidate;
candidate = NULL;
conn->channels[chan].call_counter = call_id;
rcu_assign_pointer(conn->channels[chan].call, call);
sock_hold(&rx->sk);
rxrpc_get_connection(conn);
spin_unlock(&conn->channel_lock);
spin_lock(&conn->params.peer->lock);
hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
spin_unlock(&conn->params.peer->lock);
write_lock_bh(&rxrpc_call_lock);
list_add_tail(&call->link, &rxrpc_calls);
write_unlock_bh(&rxrpc_call_lock);
/* Record copies of information for hashtable lookup */
call->family = rx->family;
call->local = conn->params.local;
switch (call->family) {
case AF_INET:
call->peer_ip.ipv4_addr =
conn->params.peer->srx.transport.sin.sin_addr.s_addr;
break;
case AF_INET6:
memcpy(call->peer_ip.ipv6_addr,
conn->params.peer->srx.transport.sin6.sin6_addr.in6_u.u6_addr8,
sizeof(call->peer_ip.ipv6_addr));
break;
default:
break;
}
call->epoch = conn->proto.epoch;
call->service_id = conn->params.service_id;
call->in_clientflag = conn->proto.in_clientflag;
/* Add the new call to the hashtable */
rxrpc_call_hash_add(call);
_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
add_timer(&call->lifetimer);
_leave(" = %p {%d} [new]", call, call->debug_id);
return call;
extant_call:
spin_unlock(&conn->channel_lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
return call;
aborted_call:
spin_unlock(&conn->channel_lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = -ECONNABORTED");
return ERR_PTR(-ECONNABORTED);
old_call:
spin_unlock(&conn->channel_lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = -ECONNRESET [old]");
return ERR_PTR(-ECONNRESET);
}
/*
* detach a call from a socket and set up for release
*/
void rxrpc_release_call(struct rxrpc_call *call)
{
struct rxrpc_connection *conn = call->conn;
struct rxrpc_sock *rx = call->socket;
_enter("{%d,%d,%d,%d}",
call->debug_id, atomic_read(&call->usage),
atomic_read(&call->ackr_not_idle),
call->rx_first_oos);
spin_lock_bh(&call->lock);
if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
BUG();
spin_unlock_bh(&call->lock);
/* dissociate from the socket
* - the socket's ref on the call is passed to the death timer
*/
_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
spin_lock(&conn->params.peer->lock);
hlist_del_init(&call->error_link);
spin_unlock(&conn->params.peer->lock);
write_lock_bh(&rx->call_lock);
if (!list_empty(&call->accept_link)) {
_debug("unlinking once-pending call %p { e=%lx f=%lx }",
call, call->events, call->flags);
ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
list_del_init(&call->accept_link);
sk_acceptq_removed(&rx->sk);
} else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
rb_erase(&call->sock_node, &rx->calls);
memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
clear_bit(RXRPC_CALL_HAS_USERID, &call->flags);
}
write_unlock_bh(&rx->call_lock);
/* free up the channel for reuse */
write_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE &&
call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
_debug("+++ ABORTING STATE %d +++\n", call->state);
call->state = RXRPC_CALL_LOCALLY_ABORTED;
call->local_abort = RX_CALL_DEAD;
}
write_unlock_bh(&call->state_lock);
rxrpc_disconnect_call(call);
/* clean up the Rx queue */
if (!skb_queue_empty(&call->rx_queue) ||
!skb_queue_empty(&call->rx_oos_queue)) {
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
_debug("purge Rx queues");
spin_lock_bh(&call->lock);
while ((skb = skb_dequeue(&call->rx_queue)) ||
(skb = skb_dequeue(&call->rx_oos_queue))) {
sp = rxrpc_skb(skb);
if (sp->call) {
ASSERTCMP(sp->call, ==, call);
rxrpc_put_call(call);
sp->call = NULL;
}
skb->destructor = NULL;
spin_unlock_bh(&call->lock);
_debug("- zap %s %%%u #%u",
rxrpc_pkts[sp->hdr.type],
sp->hdr.serial, sp->hdr.seq);
rxrpc_free_skb(skb);
spin_lock_bh(&call->lock);
}
spin_unlock_bh(&call->lock);
ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE);
}
del_timer_sync(&call->resend_timer);
del_timer_sync(&call->ack_timer);
del_timer_sync(&call->lifetimer);
call->deadspan.expires = jiffies + rxrpc_dead_call_expiry;
add_timer(&call->deadspan);
_leave("");
}
/*
* handle a dead call being ready for reaping
*/
static void rxrpc_dead_call_expired(unsigned long _call)
{
struct rxrpc_call *call = (struct rxrpc_call *) _call;
_enter("{%d}", call->debug_id);
write_lock_bh(&call->state_lock);
call->state = RXRPC_CALL_DEAD;
write_unlock_bh(&call->state_lock);
rxrpc_put_call(call);
}
/*
* mark a call as to be released, aborting it if it's still in progress
* - called with softirqs disabled
*/
static void rxrpc_mark_call_released(struct rxrpc_call *call)
{
bool sched;
write_lock(&call->state_lock);
if (call->state < RXRPC_CALL_DEAD) {
sched = false;
if (call->state < RXRPC_CALL_COMPLETE) {
_debug("abort call %p", call);
call->state = RXRPC_CALL_LOCALLY_ABORTED;
call->local_abort = RX_CALL_DEAD;
if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
sched = true;
}
if (!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
sched = true;
if (sched)
rxrpc_queue_call(call);
}
write_unlock(&call->state_lock);
}
/*
* release all the calls associated with a socket
*/
void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
{
struct rxrpc_call *call;
struct rb_node *p;
_enter("%p", rx);
read_lock_bh(&rx->call_lock);
/* mark all the calls as no longer wanting incoming packets */
for (p = rb_first(&rx->calls); p; p = rb_next(p)) {
call = rb_entry(p, struct rxrpc_call, sock_node);
rxrpc_mark_call_released(call);
}
/* kill the not-yet-accepted incoming calls */
list_for_each_entry(call, &rx->secureq, accept_link) {
rxrpc_mark_call_released(call);
}
list_for_each_entry(call, &rx->acceptq, accept_link) {
rxrpc_mark_call_released(call);
}
read_unlock_bh(&rx->call_lock);
_leave("");
}
/*
* release a call
*/
void __rxrpc_put_call(struct rxrpc_call *call)
{
ASSERT(call != NULL);
_enter("%p{u=%d}", call, atomic_read(&call->usage));
ASSERTCMP(atomic_read(&call->usage), >, 0);
if (atomic_dec_and_test(&call->usage)) {
_debug("call %d dead", call->debug_id);
ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
rxrpc_queue_work(&call->destroyer);
}
_leave("");
}
/*
* 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);
rxrpc_purge_queue(&call->rx_queue);
kmem_cache_free(rxrpc_call_jar, call);
}
/*
* clean up a call
*/
static void rxrpc_cleanup_call(struct rxrpc_call *call)
{
_net("DESTROY CALL %d", call->debug_id);
ASSERT(call->socket);
memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
del_timer_sync(&call->lifetimer);
del_timer_sync(&call->deadspan);
del_timer_sync(&call->ack_timer);
del_timer_sync(&call->resend_timer);
ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
ASSERTCMP(call->events, ==, 0);
if (work_pending(&call->processor)) {
_debug("defer destroy");
rxrpc_queue_work(&call->destroyer);
return;
}
ASSERTCMP(call->conn, ==, NULL);
/* Remove the call from the hash */
rxrpc_call_hash_del(call);
if (call->acks_window) {
_debug("kill Tx window %d",
CIRC_CNT(call->acks_head, call->acks_tail,
call->acks_winsz));
smp_mb();
while (CIRC_CNT(call->acks_head, call->acks_tail,
call->acks_winsz) > 0) {
struct rxrpc_skb_priv *sp;
unsigned long _skb;
_skb = call->acks_window[call->acks_tail] & ~1;
sp = rxrpc_skb((struct sk_buff *)_skb);
_debug("+++ clear Tx %u", sp->hdr.seq);
rxrpc_free_skb((struct sk_buff *)_skb);
call->acks_tail =
(call->acks_tail + 1) & (call->acks_winsz - 1);
}
kfree(call->acks_window);
}
rxrpc_free_skb(call->tx_pending);
rxrpc_purge_queue(&call->rx_queue);
ASSERT(skb_queue_empty(&call->rx_oos_queue));
sock_put(&call->socket->sk);
call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
}
/*
* destroy a call
*/
static void rxrpc_destroy_call(struct work_struct *work)
{
struct rxrpc_call *call =
container_of(work, struct rxrpc_call, destroyer);
_enter("%p{%d,%d,%p}",
call, atomic_read(&call->usage), call->channel, call->conn);
ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
write_lock_bh(&rxrpc_call_lock);
list_del_init(&call->link);
write_unlock_bh(&rxrpc_call_lock);
rxrpc_cleanup_call(call);
_leave("");
}
/*
* preemptively destroy all the call records from a transport endpoint rather
* than waiting for them to time out
*/
void __exit rxrpc_destroy_all_calls(void)
{
struct rxrpc_call *call;
_enter("");
write_lock_bh(&rxrpc_call_lock);
while (!list_empty(&rxrpc_calls)) {
call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
_debug("Zapping call %p", call);
list_del_init(&call->link);
switch (atomic_read(&call->usage)) {
case 0:
ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
break;
case 1:
if (del_timer_sync(&call->deadspan) != 0 &&
call->state != RXRPC_CALL_DEAD)
rxrpc_dead_call_expired((unsigned long) call);
if (call->state != RXRPC_CALL_DEAD)
break;
default:
pr_err("Call %p still in use (%d,%d,%s,%lx,%lx)!\n",
call, atomic_read(&call->usage),
atomic_read(&call->ackr_not_idle),
rxrpc_call_states[call->state],
call->flags, call->events);
if (!skb_queue_empty(&call->rx_queue))
pr_err("Rx queue occupied\n");
if (!skb_queue_empty(&call->rx_oos_queue))
pr_err("OOS queue occupied\n");
break;
}
write_unlock_bh(&rxrpc_call_lock);
cond_resched();
write_lock_bh(&rxrpc_call_lock);
}
write_unlock_bh(&rxrpc_call_lock);
_leave("");
}
/*
* handle call lifetime being exceeded
*/
static void rxrpc_call_life_expired(unsigned long _call)
{
struct rxrpc_call *call = (struct rxrpc_call *) _call;
if (call->state >= RXRPC_CALL_COMPLETE)
return;
_enter("{%d}", call->debug_id);
read_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE) {
set_bit(RXRPC_CALL_EV_LIFE_TIMER, &call->events);
rxrpc_queue_call(call);
}
read_unlock_bh(&call->state_lock);
}
/*
* handle resend timer expiry
* - may not take call->state_lock as this can deadlock against del_timer_sync()
*/
static void rxrpc_resend_time_expired(unsigned long _call)
{
struct rxrpc_call *call = (struct rxrpc_call *) _call;
_enter("{%d}", call->debug_id);
if (call->state >= RXRPC_CALL_COMPLETE)
return;
clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
if (!test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
rxrpc_queue_call(call);
}
/*
* handle ACK timer expiry
*/
static void rxrpc_ack_time_expired(unsigned long _call)
{
struct rxrpc_call *call = (struct rxrpc_call *) _call;
_enter("{%d}", call->debug_id);
if (call->state >= RXRPC_CALL_COMPLETE)
return;
read_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE &&
!test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events))
rxrpc_queue_call(call);
read_unlock_bh(&call->state_lock);
}
Reference in New Issue View Git Blame Copy Permalink