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network stack: Fixed double mutex lock. 

* device_removed() no longer uses get_device_interface() to avoid
  the double locking.
* Introduced net_device_interface::busy member to avoid locking in
  device_removed() for too long.
* This should fix #7252.
This commit is contained in:
Axel Dörfler 2017-04-06 18:14:52 +02:00
parent ceff2b88ae
commit f17488662a
2 changed files with 23 additions and 7 deletions
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25
src/add-ons/kernel/network/stack/device_interfaces.cpp
View File

@ -1,5 +1,5 @@
/*
* Copyright 2006-2010, Haiku, Inc. All Rights Reserved.
* Copyright 2006-2017, Haiku, Inc. All Rights Reserved.
* Distributed under the terms of the MIT License.
*
* Authors:
@ -152,6 +152,7 @@ domain_receive_adapter(void* cookie, net_device* device, net_buffer* buffer)
static net_device_interface*
find_device_interface(const char* name)
{
ASSERT_LOCKED_MUTEX(&sLock);
DeviceInterfaceList::Iterator iterator = sInterfaces.GetIterator();
while (net_device_interface* interface = iterator.Next()) {
@ -182,6 +183,7 @@ allocate_device_interface(net_device* device, net_device_module_info* module)
interface->device = device;
interface->up_count = 0;
interface->ref_count = 1;
interface->busy = false;
interface->monitor_count = 0;
interface->deframe_func = NULL;
interface->deframe_ref_count = 0;
@ -409,6 +411,9 @@ get_device_interface(uint32 index)
DeviceInterfaceList::Iterator iterator = sInterfaces.GetIterator();
while (net_device_interface* interface = iterator.Next()) {
if (interface->device->index == index) {
if (interface->busy)
break;
if (atomic_add(&interface->ref_count, 1) != 0)
return interface;
}
@ -428,6 +433,9 @@ get_device_interface(const char* name, bool create)
net_device_interface* interface = find_device_interface(name);
if (interface != NULL) {
if (interface->busy)
return NULL;
if (atomic_add(&interface->ref_count, 1) != 0)
return interface;
@ -763,11 +771,17 @@ device_removed(net_device* device)
{
MutexLocker locker(sLock);
// hold a reference to the device interface being removed
// so our put_() will (eventually) do the final cleanup
net_device_interface* interface = get_device_interface(device->name, false);
net_device_interface* interface = find_device_interface(device->name);
if (interface == NULL)
return B_DEVICE_NOT_FOUND;
if (interface->busy)
return B_BUSY;
// Acquire a reference to the device interface being removed
// so our put_() will (eventually) do the final cleanup
atomic_add(&interface->ref_count, 1);
interface->busy = true;
locker.Unlock();
// Propagate the loss of the device throughout the stack.
@ -776,8 +790,9 @@ device_removed(net_device* device)
// By now all of the monitors must have removed themselves. If they
// didn't, they'll probably wait forever to be callback'ed again.
recursive_lock_lock(&interface->monitor_lock);
RecursiveLocker monitorLocker(interface->monitor_lock);
interface->monitor_funcs.RemoveAll();
monitorLocker.Unlock();
// All of the readers should be gone as well since we are out of
// interfaces and put_domain_datalink_protocols() is called for

5
src/add-ons/kernel/network/stack/device_interfaces.h
View File

@ -1,5 +1,5 @@
/*
* Copyright 2006-2010, Haiku, Inc. All Rights Reserved.
* Copyright 2006-2017, Haiku, Inc. All Rights Reserved.
* Distributed under the terms of the MIT License.
*
* Authors:
@ -32,12 +32,13 @@ struct net_device_interface : DoublyLinkedListLinkImpl<net_device_interface> {
uint32 up_count;
// a device can be brought up by more than one interface
int32 ref_count;
bool busy;
net_deframe_func deframe_func;
int32 deframe_ref_count;
int32 monitor_count;
recursive_lock monitor_lock;
recursive_lock monitor_lock;
DeviceMonitorList monitor_funcs;
DeviceHandlerList receive_funcs;