* [PATCH v2] xen-netfront: Improve error handling during initialization
@ 2017-02-07 14:55 Ross Lagerwall
2017-02-07 23:33 ` Boris Ostrovsky
0 siblings, 1 reply; 7+ messages in thread
From: Ross Lagerwall @ 2017-02-07 14:55 UTC (permalink / raw)
To: xen-devel
Cc: netdev, Boris Ostrovsky, Juergen Gross, linux-kernel, wei.liu2,
Ross Lagerwall
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>
---
Changed in V2:
* Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
in xennet_disconnect_backend()".
* Don't move setup_timer as it is not necessary.
drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 722fe9f..5399a86 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1823,27 +1823,23 @@ 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");
+ if (num_queues > 0) {
+ goto destroy_ring;
+ } else {
+ 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:
@@ -1933,9 +1929,10 @@ static int talk_to_netback(struct xenbus_device *dev,
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;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2] xen-netfront: Improve error handling during initialization
2017-02-07 14:55 [PATCH v2] xen-netfront: Improve error handling during initialization Ross Lagerwall
@ 2017-02-07 23:33 ` Boris Ostrovsky
0 siblings, 0 replies; 7+ messages in thread
From: Boris Ostrovsky @ 2017-02-07 23:33 UTC (permalink / raw)
To: Ross Lagerwall, xen-devel; +Cc: netdev, Juergen Gross, linux-kernel, wei.liu2
On 02/07/2017 09:55 AM, Ross Lagerwall wrote:
> 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>
> ---
>
> Changed in V2:
> * Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
> in xennet_disconnect_backend()".
> * Don't move setup_timer as it is not necessary.
>
> drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
> 1 file changed, 15 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
> index 722fe9f..5399a86 100644
> --- a/drivers/net/xen-netfront.c
> +++ b/drivers/net/xen-netfront.c
> @@ -1823,27 +1823,23 @@ 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");
> + if (num_queues > 0) {
> + goto destroy_ring;
The only way for us to have (err<0) && (num_queues>0) is when we get a
-ENOMEM right at the top, isn't it? So there is nothing to disconnect or
destroy, it seems to me. And if that's true you can directly 'goto out'.
-boris
> + } else {
> + 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:
> @@ -1933,9 +1929,10 @@ static int talk_to_netback(struct xenbus_device *dev,
> 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;
> }
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] xen-netfront: Improve error handling during initialization
@ 2017-02-07 23:33 ` Boris Ostrovsky
0 siblings, 0 replies; 7+ messages in thread
From: Boris Ostrovsky @ 2017-02-07 23:33 UTC (permalink / raw)
To: Ross Lagerwall, xen-devel; +Cc: Juergen Gross, netdev, wei.liu2, linux-kernel
On 02/07/2017 09:55 AM, Ross Lagerwall wrote:
> 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>
> ---
>
> Changed in V2:
> * Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
> in xennet_disconnect_backend()".
> * Don't move setup_timer as it is not necessary.
>
> drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
> 1 file changed, 15 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
> index 722fe9f..5399a86 100644
> --- a/drivers/net/xen-netfront.c
> +++ b/drivers/net/xen-netfront.c
> @@ -1823,27 +1823,23 @@ 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");
> + if (num_queues > 0) {
> + goto destroy_ring;
The only way for us to have (err<0) && (num_queues>0) is when we get a
-ENOMEM right at the top, isn't it? So there is nothing to disconnect or
destroy, it seems to me. And if that's true you can directly 'goto out'.
-boris
> + } else {
> + 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:
> @@ -1933,9 +1929,10 @@ static int talk_to_netback(struct xenbus_device *dev,
> 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;
> }
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] xen-netfront: Improve error handling during initialization
2017-02-07 23:33 ` Boris Ostrovsky
(?)
@ 2017-02-08 10:32 ` Ross Lagerwall
-1 siblings, 0 replies; 7+ messages in thread
From: Ross Lagerwall @ 2017-02-08 10:32 UTC (permalink / raw)
To: Boris Ostrovsky, xen-devel; +Cc: netdev, Juergen Gross, linux-kernel, wei.liu2
On 02/07/2017 11:33 PM, Boris Ostrovsky wrote:
> On 02/07/2017 09:55 AM, Ross Lagerwall wrote:
>> 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>
>> ---
>>
>> Changed in V2:
>> * Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
>> in xennet_disconnect_backend()".
>> * Don't move setup_timer as it is not necessary.
>>
>> drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
>> 1 file changed, 15 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
>> index 722fe9f..5399a86 100644
>> --- a/drivers/net/xen-netfront.c
>> +++ b/drivers/net/xen-netfront.c
>> @@ -1823,27 +1823,23 @@ 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");
>> + if (num_queues > 0) {
>> + goto destroy_ring;
>
> The only way for us to have (err<0) && (num_queues>0) is when we get a
> -ENOMEM right at the top, isn't it? So there is nothing to disconnect or
> destroy, it seems to me. And if that's true you can directly 'goto out'.
>
You're right, although that might make it a bit more fragile if
something in xennet_create_queues() changes in the future. Nevertheless,
I'll update the patch.
--
Ross Lagerwall
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] xen-netfront: Improve error handling during initialization
@ 2017-02-08 10:32 ` Ross Lagerwall
0 siblings, 0 replies; 7+ messages in thread
From: Ross Lagerwall @ 2017-02-08 10:32 UTC (permalink / raw)
To: Boris Ostrovsky, xen-devel; +Cc: Juergen Gross, netdev, wei.liu2, linux-kernel
On 02/07/2017 11:33 PM, Boris Ostrovsky wrote:
> On 02/07/2017 09:55 AM, Ross Lagerwall wrote:
>> 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>
>> ---
>>
>> Changed in V2:
>> * Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
>> in xennet_disconnect_backend()".
>> * Don't move setup_timer as it is not necessary.
>>
>> drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
>> 1 file changed, 15 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
>> index 722fe9f..5399a86 100644
>> --- a/drivers/net/xen-netfront.c
>> +++ b/drivers/net/xen-netfront.c
>> @@ -1823,27 +1823,23 @@ 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");
>> + if (num_queues > 0) {
>> + goto destroy_ring;
>
> The only way for us to have (err<0) && (num_queues>0) is when we get a
> -ENOMEM right at the top, isn't it? So there is nothing to disconnect or
> destroy, it seems to me. And if that's true you can directly 'goto out'.
>
You're right, although that might make it a bit more fragile if
something in xennet_create_queues() changes in the future. Nevertheless,
I'll update the patch.
--
Ross Lagerwall
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] xen-netfront: Improve error handling during initialization
@ 2017-02-08 10:32 ` Ross Lagerwall
0 siblings, 0 replies; 7+ messages in thread
From: Ross Lagerwall @ 2017-02-08 10:32 UTC (permalink / raw)
To: Boris Ostrovsky, xen-devel; +Cc: Juergen Gross, netdev, wei.liu2, linux-kernel
On 02/07/2017 11:33 PM, Boris Ostrovsky wrote:
> On 02/07/2017 09:55 AM, Ross Lagerwall wrote:
>> 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>
>> ---
>>
>> Changed in V2:
>> * Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
>> in xennet_disconnect_backend()".
>> * Don't move setup_timer as it is not necessary.
>>
>> drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
>> 1 file changed, 15 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
>> index 722fe9f..5399a86 100644
>> --- a/drivers/net/xen-netfront.c
>> +++ b/drivers/net/xen-netfront.c
>> @@ -1823,27 +1823,23 @@ 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");
>> + if (num_queues > 0) {
>> + goto destroy_ring;
>
> The only way for us to have (err<0) && (num_queues>0) is when we get a
> -ENOMEM right at the top, isn't it? So there is nothing to disconnect or
> destroy, it seems to me. And if that's true you can directly 'goto out'.
>
You're right, although that might make it a bit more fragile if
something in xennet_create_queues() changes in the future. Nevertheless,
I'll update the patch.
--
Ross Lagerwall
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2] xen-netfront: Improve error handling during initialization
@ 2017-02-07 14:55 Ross Lagerwall
0 siblings, 0 replies; 7+ messages in thread
From: Ross Lagerwall @ 2017-02-07 14:55 UTC (permalink / raw)
To: xen-devel
Cc: Juergen Gross, wei.liu2, netdev, linux-kernel, Ross Lagerwall,
Boris Ostrovsky
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>
---
Changed in V2:
* Retested on top of v4.10-rc7 + "xen-netfront: Delete rx_refill_timer
in xennet_disconnect_backend()".
* Don't move setup_timer as it is not necessary.
drivers/net/xen-netfront.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 722fe9f..5399a86 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1823,27 +1823,23 @@ 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");
+ if (num_queues > 0) {
+ goto destroy_ring;
+ } else {
+ 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:
@@ -1933,9 +1929,10 @@ static int talk_to_netback(struct xenbus_device *dev,
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;
}
--
2.7.4
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 7+ messages in thread
end of thread, other threads:[~2017-02-08 10:33 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-07 14:55 [PATCH v2] xen-netfront: Improve error handling during initialization Ross Lagerwall
2017-02-07 23:33 ` Boris Ostrovsky
2017-02-07 23:33 ` Boris Ostrovsky
2017-02-08 10:32 ` Ross Lagerwall
2017-02-08 10:32 ` Ross Lagerwall
2017-02-08 10:32 ` Ross Lagerwall
2017-02-07 14:55 Ross Lagerwall
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