| Message ID | 20221123141829.1825170-1-linux@rasmusvillemoes.dk (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 31d929de5a112ee1b977a89c57de74710894bbbf |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: loopback: use NET_NAME_PREDICTABLE for name_assign_type | expand |
> -----Original Message----- > From: Rasmus Villemoes <linux@rasmusvillemoes.dk> > Sent: Wednesday, November 23, 2022 6:18 AM > To: David S. Miller <davem@davemloft.net>; Eric Dumazet > <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni > <pabeni@redhat.com> > Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>; netdev@vger.kernel.org; > linux-kernel@vger.kernel.org > Subject: [PATCH] net: loopback: use NET_NAME_PREDICTABLE for > name_assign_type > > 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 [...] > Heh, so the doc says loopback is an example of this but we weren't using it for that :D > Switch to that so that reading /sys/class/net/lo/name_assign_type > produces something sensible instead of returning -EINVAL. > This seems reasonable to me. > Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> > --- > > This is mostly cosmetic, but ideally I'd like to get to a situation > where I don't need to do > > assign_type=$(cat /sys/class/net/$dev/name_assign_type 2> /dev/null || echo > 0) > > or otherwise special-case [ $dev = "lo" ]. > > As always, there's a small chance that this could cause a regression, > but it seems extremely unlikely that anybody relies on > /sys/class/net/lo/name_assign_type being unreadable and thus > effectively is known to be NET_NAME_UNKNOWN. > I don't think I would consider this a regression. Previously name_assign_type was returning an error here, now it reports something useful. And we know the name is predictable because it is the loopback device. Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> > 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 14e8d04cb434..2e9742952c4e 100644 > --- a/drivers/net/loopback.c > +++ b/drivers/net/loopback.c > @@ -211,7 +211,7 @@ 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; > > -- > 2.37.2
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Wed, 23 Nov 2022 15:18:28 +0100 you wrote: > 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 [...] > > [...] Here is the summary with links: - net: loopback: use NET_NAME_PREDICTABLE for name_assign_type https://git.kernel.org/netdev/net/c/31d929de5a11 You are awesome, thank you!
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 14e8d04cb434..2e9742952c4e 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -211,7 +211,7 @@ 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;
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@rasmusvillemoes.dk> --- This is mostly cosmetic, but ideally I'd like to get to a situation where I don't need to do assign_type=$(cat /sys/class/net/$dev/name_assign_type 2> /dev/null || echo 0) or otherwise special-case [ $dev = "lo" ]. As always, there's a small chance that this could cause a regression, but it seems extremely unlikely that anybody relies on /sys/class/net/lo/name_assign_type being unreadable and thus effectively is known to be NET_NAME_UNKNOWN. drivers/net/loopback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)