Re: [PATCH linux-next] Documentation: fix outdated interpretation of ip_no_pmtu_disc
From: Jakub Kicinski <kuba@kernel.org>
Date: 2021-12-29 20:15:41
Also in:
lkml, netdev
On Wed, 29 Dec 2021 03:12:45 +0000 cgel.zte@gmail.com wrote:
From: xu xin <xu.xin16@zte.com.cn> The updating way of pmtu has changed, but documentation is still in the old way. See commit-id 28d35bcdd3925e7293408cdb8aa5f2aac5f0d6e3. So This
not a correct way to quote a commit, please use: %h (\"%s\") as the format.
patch fix interpretation of ip_no_pmtu_disc. Besides, min_pmtu seems not to be discoverd, but set. Reported-by: Zeal Robot <redacted>
How does the bot discover this sort of problem?
quoted hunk ↗ jump to hunk
Signed-off-by: xu xin <xu.xin16@zte.com.cn> --- Documentation/networking/ip-sysctl.rst | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index c04431144f7a..dd5e53318805 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst@@ -25,9 +25,11 @@ ip_default_ttl - INTEGER ip_no_pmtu_disc - INTEGER Disable Path MTU Discovery. If enabled in mode 1 and a fragmentation-required ICMP is received, the PMTU to this - destination will be set to min_pmtu (see below). You will need - to raise min_pmtu to the smallest interface MTU on your system - manually if you want to avoid locally generated fragments. + destination will be set to the smallest of the old MTU + and ip_rt_min_pmtu (see __ip_rt_update_pmtu() in
I don't see how this is a meaningful distinction to someone reading this documentation, more of a corner case.
+ net/ipv4/route.c). You will need to raise min_pmtu to the + smallest interface MTU on your system manually if you want to + avoid locally generated fragments.
Use tabs instead of spaces.
quoted hunk ↗ jump to hunk
In mode 2 incoming Path MTU Discovery messages will be discarded. Outgoing frames are handled the same as in mode 1,@@ -49,7 +51,7 @@ ip_no_pmtu_disc - INTEGER Default: FALSE min_pmtu - INTEGER - default 552 - minimum discovered Path MTU + default 552 - minimum set Path MTU
Also not must of an improvement IMHO.
ip_forward_use_pmtu - BOOLEAN By default we don't trust protocol path MTUs while forwarding