[PATCH AUTOSEL 5.4 5/5] net: loopback: use NET_NAME_PREDICTABLE for name_assign_type

From: Sasha Levin
Date: Thu Jun 29 2023 - 15:07:22 EST


From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 31d929de5a112ee1b977a89c57de74710894bbbf ]

When the name_assign_type attribute was introduced (commit
685343fc3ba6, "net: add name_assign_type netdev attribute"), the
loopback device was explicitly mentioned as one which would make use
of NET_NAME_PREDICTABLE:

The name_assign_type attribute gives hints where the interface name of a
given net-device comes from. These values are currently defined:
...
NET_NAME_PREDICTABLE:
The ifname has been assigned by the kernel in a predictable way
that is guaranteed to avoid reuse and always be the same for a
given device. Examples include statically created devices like
the loopback device [...]

Switch to that so that reading /sys/class/net/lo/name_assign_type
produces something sensible instead of returning -EINVAL.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/loopback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 14545a8797a8a..7788f72c262e6 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -206,7 +206,7 @@ static __net_init int loopback_net_init(struct net *net)
int err;

err = -ENOMEM;
- dev = alloc_netdev(0, "lo", NET_NAME_UNKNOWN, loopback_setup);
+ dev = alloc_netdev(0, "lo", NET_NAME_PREDICTABLE, loopback_setup);
if (!dev)
goto out;

--
2.39.2