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net/ibmnvic: Fix deadlock problem in reset

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This patch changes to use rtnl_lock only during a reset to avoid
deadlock that could occur when a thread operating close is holding
rtnl_lock and waiting for reset_lock acquired by another thread,
which is waiting for rtnl_lock in order to set the number of tx/rx
queues during a reset.

Also, we now setting the number of tx/rx queues during a soft reset
for failover or LPM events.

Signed-off-by: Juliet Kim <julietk@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Juliet Kim 2018-11-19 15:59:22 -06:00 committed by David S. Miller
parent db9a0bae8f
commit a5681e20b5
2 changed files with 22 additions and 39 deletions
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59
drivers/net/ethernet/ibm/ibmvnic.c
View File

@ -1103,20 +1103,15 @@ static int ibmvnic_open(struct net_device *netdev)
return 0;
}
mutex_lock(&adapter->reset_lock);
if (adapter->state != VNIC_CLOSED) {
rc = ibmvnic_login(netdev);
if (rc) {
mutex_unlock(&adapter->reset_lock);
if (rc)
return rc;
}
rc = init_resources(adapter);
if (rc) {
netdev_err(netdev, "failed to initialize resources\n");
release_resources(adapter);
mutex_unlock(&adapter->reset_lock);
return rc;
}
}
@ -1124,8 +1119,6 @@ static int ibmvnic_open(struct net_device *netdev)
rc = __ibmvnic_open(netdev);
netif_carrier_on(netdev);
mutex_unlock(&adapter->reset_lock);
return rc;
}
@ -1269,10 +1262,8 @@ static int ibmvnic_close(struct net_device *netdev)
return 0;
}
mutex_lock(&adapter->reset_lock);
rc = __ibmvnic_close(netdev);
ibmvnic_cleanup(netdev);
mutex_unlock(&adapter->reset_lock);
return rc;
}
@ -1820,20 +1811,15 @@ static int do_reset(struct ibmvnic_adapter *adapter,
return rc;
} else if (adapter->req_rx_queues != old_num_rx_queues ||
adapter->req_tx_queues != old_num_tx_queues) {
adapter->map_id = 1;
release_rx_pools(adapter);
release_tx_pools(adapter);
rc = init_rx_pools(netdev);
if (rc)
return rc;
rc = init_tx_pools(netdev);
release_napi(adapter);
release_vpd_data(adapter);
rc = init_resources(adapter);
if (rc)
return rc;
release_napi(adapter);
rc = init_napi(adapter);
if (rc)
return rc;
} else {
rc = reset_tx_pools(adapter);
if (rc)
@ -1917,17 +1903,8 @@ static int do_hard_reset(struct ibmvnic_adapter *adapter,
adapter->state = VNIC_PROBED;
return 0;
}
/* netif_set_real_num_xx_queues needs to take rtnl lock here
* unless wait_for_reset is set, in which case the rtnl lock
* has already been taken before initializing the reset
*/
if (!adapter->wait_for_reset) {
rtnl_lock();
rc = init_resources(adapter);
rtnl_unlock();
} else {
rc = init_resources(adapter);
}
rc = init_resources(adapter);
if (rc)
return rc;
@ -1986,13 +1963,21 @@ static void __ibmvnic_reset(struct work_struct *work)
struct ibmvnic_rwi *rwi;
struct ibmvnic_adapter *adapter;
struct net_device *netdev;
bool we_lock_rtnl = false;
u32 reset_state;
int rc = 0;
adapter = container_of(work, struct ibmvnic_adapter, ibmvnic_reset);
netdev = adapter->netdev;
mutex_lock(&adapter->reset_lock);
/* netif_set_real_num_xx_queues needs to take rtnl lock here
* unless wait_for_reset is set, in which case the rtnl lock
* has already been taken before initializing the reset
*/
if (!adapter->wait_for_reset) {
rtnl_lock();
we_lock_rtnl = true;
}
reset_state = adapter->state;
rwi = get_next_rwi(adapter);
@ -2020,12 +2005,11 @@ static void __ibmvnic_reset(struct work_struct *work)
if (rc) {
netdev_dbg(adapter->netdev, "Reset failed\n");
free_all_rwi(adapter);
mutex_unlock(&adapter->reset_lock);
return;
}
adapter->resetting = false;
mutex_unlock(&adapter->reset_lock);
if (we_lock_rtnl)
rtnl_unlock();
}
static int ibmvnic_reset(struct ibmvnic_adapter *adapter,
@ -4768,7 +4752,6 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
INIT_WORK(&adapter->ibmvnic_reset, __ibmvnic_reset);
INIT_LIST_HEAD(&adapter->rwi_list);
mutex_init(&adapter->reset_lock);
mutex_init(&adapter->rwi_lock);
adapter->resetting = false;
@ -4840,8 +4823,8 @@ static int ibmvnic_remove(struct vio_dev *dev)
struct ibmvnic_adapter *adapter = netdev_priv(netdev);
adapter->state = VNIC_REMOVING;
unregister_netdev(netdev);
mutex_lock(&adapter->reset_lock);
rtnl_lock();
unregister_netdevice(netdev);
release_resources(adapter);
release_sub_crqs(adapter, 1);
@ -4852,7 +4835,7 @@ static int ibmvnic_remove(struct vio_dev *dev)
adapter->state = VNIC_REMOVED;
mutex_unlock(&adapter->reset_lock);
rtnl_unlock();
device_remove_file(&dev->dev, &dev_attr_failover);
free_netdev(netdev);
dev_set_drvdata(&dev->dev, NULL);

2
drivers/net/ethernet/ibm/ibmvnic.h
View File

@ -1075,7 +1075,7 @@ struct ibmvnic_adapter {
struct tasklet_struct tasklet;
enum vnic_state state;
enum ibmvnic_reset_reason reset_reason;
struct mutex reset_lock, rwi_lock;
struct mutex rwi_lock;
struct list_head rwi_list;
struct work_struct ibmvnic_reset;
bool resetting;