Commit 7eeb84d8 authored by Breno Leitao's avatar Breno Leitao Committed by Jakub Kicinski
Browse files

Documentation: netconsole: add support for cmdline targets 

With the previous patches, there is no more limitation at modifying the
targets created at boot time (or module load time).

Document the way on how to create the configfs directories to be able to
modify these netconsole targets.

The design discussion about this topic could be found at:
https://lore.kernel.org/all/ZRWRal5bW93px4km@gmail.com/



Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20231012111401.333798-5-leitao@debian.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5fbd6cdb

Documentation/networking/netconsole.rst

+19 −3
Original line number Diff line number Diff line
@@ -99,9 +99,6 @@ Dynamic reconfiguration: 
Dynamic reconfigurability is a useful addition to netconsole that enables

remote logging targets to be dynamically added, removed, or have their

parameters reconfigured at runtime from a configfs-based userspace interface.

[ Note that the parameters of netconsole targets that were specified/created

from the boot/module option are not exposed via this interface, and hence

cannot be modified dynamically. ]



To include this feature, select CONFIG_NETCONSOLE_DYNAMIC when building the

netconsole module (or kernel, if netconsole is built-in).
@@ -155,6 +152,25 @@ You can also update the local interface dynamically. This is especially 
useful if you want to use interfaces that have newly come up (and may not

have existed when netconsole was loaded / initialized).



Netconsole targets defined at boot time (or module load time) with the

`netconsole=` param are assigned the name `cmdline<index>`.  For example, the

first target in the parameter is named `cmdline0`.  You can control and modify

these targets by creating configfs directories with the matching name.



Let's suppose you have two netconsole targets defined at boot time::



 netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc;4444@10.0.0.1/eth1,9353@10.0.0.3/12:34:56:78:9a:bc



You can modify these targets in runtime by creating the following targets::



 mkdir cmdline0

 cat cmdline0/remote_ip

 10.0.0.2



 mkdir cmdline1

 cat cmdline1/remote_ip

 10.0.0.3



Extended console:

=================