[PATCH] Skip down interfaces

[PATCH] Skip down interfaces

[Dan Smith]

This makes the netns checkpoint code skip interfaces that are not up.
Later, we want to make it possible to checkpoint down interfaces with
a flag, but for now this helps prevent people from getting stuck on
stock kernels with various unsupported and persistent virtual interfaces,
such as tunnel devices.

Signed-off-by: Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
Cc: serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org
---
 net/checkpoint_dev.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/net/checkpoint_dev.c b/net/checkpoint_dev.c
index bc0415d..1e053f9 100644
--- a/net/checkpoint_dev.c
+++ b/net/checkpoint_dev.c
@@ -268,7 +268,13 @@ int checkpoint_netns(struct ckpt_ctx *ctx, void *ptr)
 		goto out;
 
 	for_each_netdev(net, dev) {
-		ret = checkpoint_obj(ctx, dev, CKPT_OBJ_NETDEV);
+		if (dev->flags & IFF_UP)
+			ret = checkpoint_obj(ctx, dev, CKPT_OBJ_NETDEV);
+		else
+			/* TODO: There should be a flag to enable checkpoint
+			 * of downed interfaces
+			 */
+			ret = 0;
 		if (ret < 0)
 			break;
 	}
-- 
1.6.2.5

Re: [PATCH] Skip down interfaces

[Serge E. Hallyn]

Quoting Dan Smith (danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org):
> This makes the netns checkpoint code skip interfaces that are not up.
> Later, we want to make it possible to checkpoint down interfaces with
> a flag, but for now this helps prevent people from getting stuck on
> stock kernels with various unsupported and persistent virtual interfaces,
> such as tunnel devices.
> 
> Signed-off-by: Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>

Acked-by: Serge Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
Tested-by: Serge Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>

Now this really is only a problem for devices which use
register_pernet_device() right?  Could/should we add a
flag to such devices, and only skip those when they're
down?

Or, can we detect whether the device has a checkpoint
operation, checkpoint it if so regardless, and, if not,
if it is down, skip it?

Mind you if noone minds this patch (for now) then it
works for me.

thanks,
-serge

> Cc: serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org
> ---
>  net/checkpoint_dev.c |    8 +++++++-
>  1 files changed, 7 insertions(+), 1 deletions(-)
> 
> diff --git a/net/checkpoint_dev.c b/net/checkpoint_dev.c
> index bc0415d..1e053f9 100644
> --- a/net/checkpoint_dev.c
> +++ b/net/checkpoint_dev.c
> @@ -268,7 +268,13 @@ int checkpoint_netns(struct ckpt_ctx *ctx, void *ptr)
>  		goto out;
> 
>  	for_each_netdev(net, dev) {
> -		ret = checkpoint_obj(ctx, dev, CKPT_OBJ_NETDEV);
> +		if (dev->flags & IFF_UP)
> +			ret = checkpoint_obj(ctx, dev, CKPT_OBJ_NETDEV);
> +		else
> +			/* TODO: There should be a flag to enable checkpoint
> +			 * of downed interfaces
> +			 */
> +			ret = 0;
>  		if (ret < 0)
>  			break;
>  	}
> -- 
> 1.6.2.5

Re: [PATCH] Skip down interfaces

[Dan Smith]

SH> Or, can we detect whether the device has a checkpoint operation,
SH> checkpoint it if so regardless, and, if not, if it is down, skip
SH> it?

Oh, you know what... I originally had it so that it only skips
interfaces that are down *and* unsupported.  However, I swizzled it
after that and didn't preserve that logic.

Let me re-swizzle and I'll post again.

-- 
Dan Smith
IBM Linux Technology Center
email: danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org