Re: [patch net-next v3 0/3] net: devlink: Finish network namespace support

[David Ahern <dsahern@gmail.com>]

On 8/12/19 7:47 AM, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@mellanox.com>
> 
> Devlink from the beginning counts with network namespaces, but the
> instances has been fixed to init_net. The first patch allows user
> to move existing devlink instances into namespaces:
> 
> $ devlink dev
> netdevsim/netdevsim1
> $ ip netns add ns1
> $ devlink dev set netdevsim/netdevsim1 netns ns1
> $ devlink -N ns1 dev
> netdevsim/netdevsim1
> 
> The last patch allows user to create new netdevsim instance directly
> inside network namespace of a caller.

The namespace behavior seems odd to me. If devlink instance is created
in a namespace and never moved, it should die with the namespace. With
this patch set, devlink instance and its ports are moved to init_net on
namespace delete.

The fib controller needs an update to return the namespace of the
devlink instance (on top of the patch applied to net):

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 89795071f085..fa7e876f2d3b 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -114,11 +114,6 @@ static void nsim_dev_port_debugfs_exit(struct
nsim_dev_port *nsim_dev_port)
        debugfs_remove_recursive(nsim_dev_port->ddir);
 }

-static struct net *nsim_devlink_net(struct devlink *devlink)
-{
-       return &init_net;
-}
-
 static u64 nsim_dev_ipv4_fib_resource_occ_get(void *priv)
 {
        struct net *net = priv;
@@ -154,7 +149,7 @@ static int nsim_dev_resources_register(struct
devlink *devlink)
                .size_granularity = 1,
                .unit = DEVLINK_RESOURCE_UNIT_ENTRY
        };
-       struct net *net = nsim_devlink_net(devlink);
+       struct net *net = devlink_net(devlink);
        int err;
        u64 n;

@@ -309,7 +304,7 @@ static int nsim_dev_reload(struct devlink *devlink,
                NSIM_RESOURCE_IPV4_FIB, NSIM_RESOURCE_IPV4_FIB_RULES,
                NSIM_RESOURCE_IPV6_FIB, NSIM_RESOURCE_IPV6_FIB_RULES
        };
-       struct net *net = nsim_devlink_net(devlink);
+       struct net *net = devlink_net(devlink);
        int i;

        for (i = 0; i < ARRAY_SIZE(res_ids); ++i) {