linux_dsm_epyc7002/net/rxrpc/call_object.c
David Howells 372ee16386 rxrpc: Fix races between skb free, ACK generation and replying
Inside the kafs filesystem it is possible to occasionally have a call
processed and terminated before we've had a chance to check whether we need
to clean up the rx queue for that call because afs_send_simple_reply() ends
the call when it is done, but this is done in a workqueue item that might
happen to run to completion before afs_deliver_to_call() completes.

Further, it is possible for rxrpc_kernel_send_data() to be called to send a
reply before the last request-phase data skb is released.  The rxrpc skb
destructor is where the ACK processing is done and the call state is
advanced upon release of the last skb.  ACK generation is also deferred to
a work item because it's possible that the skb destructor is not called in
a context where kernel_sendmsg() can be invoked.

To this end, the following changes are made:

 (1) kernel_rxrpc_data_consumed() is added.  This should be called whenever
     an skb is emptied so as to crank the ACK and call states.  This does
     not release the skb, however.  kernel_rxrpc_free_skb() must now be
     called to achieve that.  These together replace
     rxrpc_kernel_data_delivered().

 (2) kernel_rxrpc_data_consumed() is wrapped by afs_data_consumed().

     This makes afs_deliver_to_call() easier to work as the skb can simply
     be discarded unconditionally here without trying to work out what the
     return value of the ->deliver() function means.

     The ->deliver() functions can, via afs_data_complete(),
     afs_transfer_reply() and afs_extract_data() mark that an skb has been
     consumed (thereby cranking the state) without the need to
     conditionally free the skb to make sure the state is correct on an
     incoming call for when the call processor tries to send the reply.

 (3) rxrpc_recvmsg() now has to call kernel_rxrpc_data_consumed() when it
     has finished with a packet and MSG_PEEK isn't set.

 (4) rxrpc_packet_destructor() no longer calls rxrpc_hard_ACK_data().

     Because of this, we no longer need to clear the destructor and put the
     call before we free the skb in cases where we don't want the ACK/call
     state to be cranked.

 (5) The ->deliver() call-type callbacks are made to return -EAGAIN rather
     than 0 if they expect more data (afs_extract_data() returns -EAGAIN to
     the delivery function already), and the caller is now responsible for
     producing an abort if that was the last packet.

 (6) There are many bits of unmarshalling code where:

 		ret = afs_extract_data(call, skb, last, ...);
		switch (ret) {
		case 0:		break;
		case -EAGAIN:	return 0;
		default:	return ret;
		}

     is to be found.  As -EAGAIN can now be passed back to the caller, we
     now just return if ret < 0:

 		ret = afs_extract_data(call, skb, last, ...);
		if (ret < 0)
			return ret;

 (7) Checks for trailing data and empty final data packets has been
     consolidated as afs_data_complete().  So:

		if (skb->len > 0)
			return -EBADMSG;
		if (!last)
			return 0;

     becomes:

		ret = afs_data_complete(call, skb, last);
		if (ret < 0)
			return ret;

 (8) afs_transfer_reply() now checks the amount of data it has against the
     amount of data desired and the amount of data in the skb and returns
     an error to induce an abort if we don't get exactly what we want.

Without these changes, the following oops can occasionally be observed,
particularly if some printks are inserted into the delivery path:

general protection fault: 0000 [#1] SMP
Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc]
CPU: 0 PID: 1305 Comm: kworker/u8:3 Tainted: G            E   4.7.0-fsdevel+ #1303
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Workqueue: kafsd afs_async_workfn [kafs]
task: ffff88040be041c0 ti: ffff88040c070000 task.ti: ffff88040c070000
RIP: 0010:[<ffffffff8108fd3c>]  [<ffffffff8108fd3c>] __lock_acquire+0xcf/0x15a1
RSP: 0018:ffff88040c073bc0  EFLAGS: 00010002
RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000000 RCX: ffff88040d29a710
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88040d29a710
RBP: ffff88040c073c70 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88040be041c0 R15: ffffffff814c928f
FS:  0000000000000000(0000) GS:ffff88041fa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4595f4750 CR3: 0000000001c14000 CR4: 00000000001406f0
Stack:
 0000000000000006 000000000be04930 0000000000000000 ffff880400000000
 ffff880400000000 ffffffff8108f847 ffff88040be041c0 ffffffff81050446
 ffff8803fc08a920 ffff8803fc08a958 ffff88040be041c0 ffff88040c073c38
Call Trace:
 [<ffffffff8108f847>] ? mark_held_locks+0x5e/0x74
 [<ffffffff81050446>] ? __local_bh_enable_ip+0x9b/0xa1
 [<ffffffff8108f9ca>] ? trace_hardirqs_on_caller+0x16d/0x189
 [<ffffffff810915f4>] lock_acquire+0x122/0x1b6
 [<ffffffff810915f4>] ? lock_acquire+0x122/0x1b6
 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
 [<ffffffff81609dbf>] _raw_spin_lock_irqsave+0x35/0x49
 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
 [<ffffffff814c928f>] skb_dequeue+0x18/0x61
 [<ffffffffa009aa92>] afs_deliver_to_call+0x344/0x39d [kafs]
 [<ffffffffa009ab37>] afs_process_async_call+0x4c/0xd5 [kafs]
 [<ffffffffa0099e9c>] afs_async_workfn+0xe/0x10 [kafs]
 [<ffffffff81063a3a>] process_one_work+0x29d/0x57c
 [<ffffffff81064ac2>] worker_thread+0x24a/0x385
 [<ffffffff81064878>] ? rescuer_thread+0x2d0/0x2d0
 [<ffffffff810696f5>] kthread+0xf3/0xfb
 [<ffffffff8160a6ff>] ret_from_fork+0x1f/0x40
 [<ffffffff81069602>] ? kthread_create_on_node+0x1cf/0x1cf

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-06 00:08:40 -04:00

799 lines
20 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.
*/
#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"
/*
* 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);
/*
* 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;
call->local = rx->local;
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;
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);
call->local = conn->params.local;
call->epoch = conn->proto.epoch;
call->service_id = conn->params.service_id;
call->in_clientflag = RXRPC_CLIENT_INITIATED;
_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))) {
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);
WARN_ON(atomic_read(&call->skb_count) != 0);
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);
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);
}