linux/net/rxrpc/ar-call.c
David Howells 3b5bac2bde RxRPC: Fix a potential deadlock between the call resend_timer and state_lock
RxRPC can potentially deadlock as rxrpc_resend_time_expired() wants to get
call->state_lock so that it can alter the state of an RxRPC call.  However, its
caller (call_timer_fn()) has an apparent lock on the timer struct.

The problem is that rxrpc_resend_time_expired() isn't permitted to lock
call->state_lock as this could cause a deadlock against rxrpc_send_abort() as
that takes state_lock and then attempts to delete the resend timer by calling
del_timer_sync().

The deadlock can occur because del_timer_sync() will sit there forever waiting
for rxrpc_resend_time_expired() to return, but the latter may then wait for
call->state_lock, which rxrpc_send_abort() holds around del_timer_sync()...

This leads to a warning appearing in the kernel log that looks something like
the attached.

It should be sufficient to simply dispense with the locks.  It doesn't matter
if we set the resend timer expired event bit and queue the event processor
whilst we're changing state to one where the resend timer is irrelevant as the
event can just be ignored by the processor thereafter.

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.35-rc3-cachefs+ #115
-------------------------------------------------------
swapper/0 is trying to acquire lock:
 (&call->state_lock){++--..}, at: [<ffffffffa00200d4>] rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc]

but task is already holding lock:
 (&call->resend_timer){+.-...}, at: [<ffffffff8103b675>] run_timer_softirq+0x182/0x2a5

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&call->resend_timer){+.-...}:
       [<ffffffff810560bc>] __lock_acquire+0x889/0x8fa
       [<ffffffff81056184>] lock_acquire+0x57/0x6d
       [<ffffffff8103bb9c>] del_timer_sync+0x3c/0x86
       [<ffffffffa002bb7a>] rxrpc_send_abort+0x50/0x97 [af_rxrpc]
       [<ffffffffa002bdd9>] rxrpc_kernel_abort_call+0xa1/0xdd [af_rxrpc]
       [<ffffffffa0061588>] afs_deliver_to_call+0x129/0x368 [kafs]
       [<ffffffffa006181b>] afs_process_async_call+0x54/0xff [kafs]
       [<ffffffff8104261d>] worker_thread+0x1ef/0x2e2
       [<ffffffff81045f47>] kthread+0x7a/0x82
       [<ffffffff81002cd4>] kernel_thread_helper+0x4/0x10

-> #0 (&call->state_lock){++--..}:
       [<ffffffff81055237>] validate_chain+0x727/0xd23
       [<ffffffff810560bc>] __lock_acquire+0x889/0x8fa
       [<ffffffff81056184>] lock_acquire+0x57/0x6d
       [<ffffffff813e6b69>] _raw_read_lock_bh+0x34/0x43
       [<ffffffffa00200d4>] rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc]
       [<ffffffff8103b6e6>] run_timer_softirq+0x1f3/0x2a5
       [<ffffffff81036828>] __do_softirq+0xa2/0x13e
       [<ffffffff81002dcc>] call_softirq+0x1c/0x28
       [<ffffffff810049f0>] do_softirq+0x38/0x80
       [<ffffffff810361a2>] irq_exit+0x45/0x47
       [<ffffffff81018fb3>] smp_apic_timer_interrupt+0x88/0x96
       [<ffffffff81002893>] apic_timer_interrupt+0x13/0x20
       [<ffffffff810011ac>] cpu_idle+0x4d/0x83
       [<ffffffff813e06f3>] start_secondary+0x1bd/0x1c1

other info that might help us debug this:

1 lock held by swapper/0:
 #0:  (&call->resend_timer){+.-...}, at: [<ffffffff8103b675>] run_timer_softirq+0x182/0x2a5

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.35-rc3-cachefs+ #115
Call Trace:
 <IRQ>  [<ffffffff81054414>] print_circular_bug+0xae/0xbd
 [<ffffffff81055237>] validate_chain+0x727/0xd23
 [<ffffffff810560bc>] __lock_acquire+0x889/0x8fa
 [<ffffffff810539a7>] ? mark_lock+0x42f/0x51f
 [<ffffffff81056184>] lock_acquire+0x57/0x6d
 [<ffffffffa00200d4>] ? rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc]
 [<ffffffff813e6b69>] _raw_read_lock_bh+0x34/0x43
 [<ffffffffa00200d4>] ? rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc]
 [<ffffffffa00200d4>] rxrpc_resend_time_expired+0x56/0x96 [af_rxrpc]
 [<ffffffff8103b6e6>] run_timer_softirq+0x1f3/0x2a5
 [<ffffffff8103b675>] ? run_timer_softirq+0x182/0x2a5
 [<ffffffffa002007e>] ? rxrpc_resend_time_expired+0x0/0x96 [af_rxrpc]
 [<ffffffff810367ef>] ? __do_softirq+0x69/0x13e
 [<ffffffff81036828>] __do_softirq+0xa2/0x13e
 [<ffffffff81002dcc>] call_softirq+0x1c/0x28
 [<ffffffff810049f0>] do_softirq+0x38/0x80
 [<ffffffff810361a2>] irq_exit+0x45/0x47
 [<ffffffff81018fb3>] smp_apic_timer_interrupt+0x88/0x96
 [<ffffffff81002893>] apic_timer_interrupt+0x13/0x20
 <EOI>  [<ffffffff81049de1>] ? __atomic_notifier_call_chain+0x0/0x86
 [<ffffffff8100955b>] ? mwait_idle+0x6e/0x78
 [<ffffffff81009552>] ? mwait_idle+0x65/0x78
 [<ffffffff810011ac>] cpu_idle+0x4d/0x83
 [<ffffffff813e06f3>] start_secondary+0x1bd/0x1c1

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-04 21:53:16 -07:00

823 lines
21 KiB
C

/* 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.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
const char *const rxrpc_call_states[] = {
[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 unsigned rxrpc_call_max_lifetime = 60;
static unsigned rxrpc_dead_call_timeout = 2;
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);
/*
* 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->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);
call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
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_MAXACKS;
call->creation_jif = jiffies;
return call;
}
/*
* allocate a new client call and attempt to get a connection slot for it
*/
static struct rxrpc_call *rxrpc_alloc_client_call(
struct rxrpc_sock *rx,
struct rxrpc_transport *trans,
struct rxrpc_conn_bundle *bundle,
gfp_t gfp)
{
struct rxrpc_call *call;
int ret;
_enter("");
ASSERT(rx != NULL);
ASSERT(trans != NULL);
ASSERT(bundle != NULL);
call = rxrpc_alloc_call(gfp);
if (!call)
return ERR_PTR(-ENOMEM);
sock_hold(&rx->sk);
call->socket = rx;
call->rx_data_post = 1;
ret = rxrpc_connect_call(rx, trans, bundle, call, gfp);
if (ret < 0) {
kmem_cache_free(rxrpc_call_jar, call);
return ERR_PTR(ret);
}
spin_lock(&call->conn->trans->peer->lock);
list_add(&call->error_link, &call->conn->trans->peer->error_targets);
spin_unlock(&call->conn->trans->peer->lock);
call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
add_timer(&call->lifetimer);
_leave(" = %p", call);
return call;
}
/*
* set up a call for the given data
* - called in process context with IRQs enabled
*/
struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *rx,
struct rxrpc_transport *trans,
struct rxrpc_conn_bundle *bundle,
unsigned long user_call_ID,
int create,
gfp_t gfp)
{
struct rxrpc_call *call, *candidate;
struct rb_node *p, *parent, **pp;
_enter("%p,%d,%d,%lx,%d",
rx, trans ? trans->debug_id : -1, bundle ? bundle->debug_id : -1,
user_call_ID, create);
/* search the extant calls first for one that matches the specified
* user 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);
if (!create || !trans)
return ERR_PTR(-EBADSLT);
/* not yet present - create a candidate for a new record and then
* redo the search */
candidate = rxrpc_alloc_client_call(rx, trans, bundle, gfp);
if (IS_ERR(candidate)) {
_leave(" = %ld", PTR_ERR(candidate));
return candidate;
}
candidate->user_call_ID = user_call_ID;
__set_bit(RXRPC_CALL_HAS_USERID, &candidate->flags);
write_lock(&rx->call_lock);
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 found_extant_second;
}
/* second search also failed; add the new call */
call = candidate;
candidate = NULL;
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);
_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
_leave(" = %p [new]", call);
return call;
/* we found the call in the list immediately */
found_extant_call:
rxrpc_get_call(call);
read_unlock(&rx->call_lock);
_leave(" = %p [extant %d]", call, atomic_read(&call->usage));
return call;
/* we found the call on the second time through the list */
found_extant_second:
rxrpc_get_call(call);
write_unlock(&rx->call_lock);
rxrpc_put_call(candidate);
_leave(" = %p [second %d]", call, atomic_read(&call->usage));
return call;
}
/*
* 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 rxrpc_header *hdr,
gfp_t gfp)
{
struct rxrpc_call *call, *candidate;
struct rb_node **p, *parent;
__be32 call_id;
_enter(",%d,,%x", conn->debug_id, gfp);
ASSERT(rx != NULL);
candidate = rxrpc_alloc_call(gfp);
if (!candidate)
return ERR_PTR(-EBUSY);
candidate->socket = rx;
candidate->conn = conn;
candidate->cid = hdr->cid;
candidate->call_id = hdr->callNumber;
candidate->channel = ntohl(hdr->cid) & RXRPC_CHANNELMASK;
candidate->rx_data_post = 0;
candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
if (conn->security_ix > 0)
candidate->state = RXRPC_CALL_SERVER_SECURING;
write_lock_bh(&conn->lock);
/* set the channel for this call */
call = conn->channels[candidate->channel];
_debug("channel[%u] is %p", candidate->channel, call);
if (call && call->call_id == 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_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) {
conn->channels[call->channel] = NULL;
} else {
write_unlock_bh(&conn->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 = hdr->callNumber;
p = &conn->calls.rb_node;
parent = NULL;
while (*p) {
parent = *p;
call = rb_entry(parent, struct rxrpc_call, conn_node);
if (call_id < call->call_id)
p = &(*p)->rb_left;
else if (call_id > call->call_id)
p = &(*p)->rb_right;
else
goto old_call;
}
/* make the call available */
_debug("new call");
call = candidate;
candidate = NULL;
rb_link_node(&call->conn_node, parent, p);
rb_insert_color(&call->conn_node, &conn->calls);
conn->channels[call->channel] = call;
sock_hold(&rx->sk);
atomic_inc(&conn->usage);
write_unlock_bh(&conn->lock);
spin_lock(&conn->trans->peer->lock);
list_add(&call->error_link, &conn->trans->peer->error_targets);
spin_unlock(&conn->trans->peer->lock);
write_lock_bh(&rxrpc_call_lock);
list_add_tail(&call->link, &rxrpc_calls);
write_unlock_bh(&rxrpc_call_lock);
_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
add_timer(&call->lifetimer);
_leave(" = %p {%d} [new]", call, call->debug_id);
return call;
extant_call:
write_unlock_bh(&conn->lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
return call;
aborted_call:
write_unlock_bh(&conn->lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = -ECONNABORTED");
return ERR_PTR(-ECONNABORTED);
old_call:
write_unlock_bh(&conn->lock);
kmem_cache_free(rxrpc_call_jar, candidate);
_leave(" = -ECONNRESET [old]");
return ERR_PTR(-ECONNRESET);
}
/*
* find an extant server call
* - called in process context with IRQs enabled
*/
struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *rx,
unsigned long user_call_ID)
{
struct rxrpc_call *call;
struct rb_node *p;
_enter("%p,%lx", rx, user_call_ID);
/* search the extant calls for one that matches the specified user
* 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;
/* we found the call in the list immediately */
found_extant_call:
rxrpc_get_call(call);
read_unlock(&rx->call_lock);
_leave(" = %p [%d]", call, atomic_read(&call->usage));
return call;
}
/*
* 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);
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 */
spin_lock(&conn->trans->client_lock);
write_lock_bh(&conn->lock);
write_lock(&call->state_lock);
if (conn->channels[call->channel] == call)
conn->channels[call->channel] = NULL;
if (conn->out_clientflag && conn->bundle) {
conn->avail_calls++;
switch (conn->avail_calls) {
case 1:
list_move_tail(&conn->bundle_link,
&conn->bundle->avail_conns);
case 2 ... RXRPC_MAXCALLS - 1:
ASSERT(conn->channels[0] == NULL ||
conn->channels[1] == NULL ||
conn->channels[2] == NULL ||
conn->channels[3] == NULL);
break;
case RXRPC_MAXCALLS:
list_move_tail(&conn->bundle_link,
&conn->bundle->unused_conns);
ASSERT(conn->channels[0] == NULL &&
conn->channels[1] == NULL &&
conn->channels[2] == NULL &&
conn->channels[3] == NULL);
break;
default:
printk(KERN_ERR "RxRPC: conn->avail_calls=%d\n",
conn->avail_calls);
BUG();
}
}
spin_unlock(&conn->trans->client_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->abort_code = RX_CALL_DEAD;
set_bit(RXRPC_CALL_ABORT, &call->events);
rxrpc_queue_call(call);
}
write_unlock(&call->state_lock);
write_unlock_bh(&conn->lock);
/* 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],
ntohl(sp->hdr.serial),
ntohl(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_timeout * HZ;
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->abort_code = RX_CALL_DEAD;
if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
sched = true;
}
if (!test_and_set_bit(RXRPC_CALL_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("");
}
/*
* 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;
}
if (call->conn) {
spin_lock(&call->conn->trans->peer->lock);
list_del(&call->error_link);
spin_unlock(&call->conn->trans->peer->lock);
write_lock_bh(&call->conn->lock);
rb_erase(&call->conn_node, &call->conn->calls);
write_unlock_bh(&call->conn->lock);
rxrpc_put_connection(call->conn);
}
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", ntohl(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);
kmem_cache_free(rxrpc_call_jar, 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:
printk(KERN_ERR "RXRPC:"
" 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))
printk(KERN_ERR"RXRPC: Rx queue occupied\n");
if (!skb_queue_empty(&call->rx_oos_queue))
printk(KERN_ERR"RXRPC: 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_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_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_ACK, &call->events))
rxrpc_queue_call(call);
read_unlock_bh(&call->state_lock);
}