iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

xen-netfront: Improve error handling during initialization

Browse Source 
This fixes a crash when running out of grant refs when creating many
queues across many netdevs.

* If creating queues fails (i.e. there are no grant refs available),
call xenbus_dev_fatal() to ensure that the xenbus device is set to the
closed state.
* If no queues are created, don't call xennet_disconnect_backend as
netdev->real_num_tx_queues will not have been set correctly.
* If setup_netfront() fails, ensure that all the queues created are
cleaned up, not just those that have been set up.
* If any queues were set up and an error occurs, call
xennet_destroy_queues() to clean up the napi context.
* If any fatal error occurs, unregister and destroy the netdev to avoid
leaving around a half setup network device.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ross Lagerwall 2017-02-08 10:57:37 +00:00 committed by David S. Miller
parent 1b5805c29c
commit e2e004acc7
1 changed files with 11 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/net/xen-netfront.c
View File

@ -1830,27 +1830,19 @@ static int talk_to_netback(struct xenbus_device *dev,
xennet_destroy_queues(info);
err = xennet_create_queues(info, &num_queues);
if (err < 0)
goto destroy_ring;
if (err < 0) {
xenbus_dev_fatal(dev, err, "creating queues");
kfree(info->queues);
info->queues = NULL;
goto out;
}
/* Create shared ring, alloc event channel -- for each queue */
for (i = 0; i < num_queues; ++i) {
queue = &info->queues[i];
err = setup_netfront(dev, queue, feature_split_evtchn);
if (err) {
/* setup_netfront() will tidy up the current
* queue on error, but we need to clean up
* those already allocated.
*/
if (i > 0) {
rtnl_lock();
netif_set_real_num_tx_queues(info->netdev, i);
rtnl_unlock();
goto destroy_ring;
} else {
goto out;
}
}
if (err)
goto destroy_ring;
}
again:
@ -1940,9 +1932,10 @@ abort_transaction_no_dev_fatal:
xenbus_transaction_end(xbt, 1);
destroy_ring:
xennet_disconnect_backend(info);
kfree(info->queues);
info->queues = NULL;
xennet_destroy_queues(info);
out:
unregister_netdev(info->netdev);
xennet_free_netdev(info->netdev);
return err;
}