On Sun, May 09, 2010 at 11:17:04AM +0800, Marek Lindner wrote:

Hi,

Greg asked us to provide an ABI documentation for the files creates in the sysfs tree. Since I am respsonsible for the sysfs stuff, I felt it was my turn to draft something. Please check the attachments and let me know whether you think we can send it or not.

What: /sys/class/net/<mesh_iface>/mesh/originators Date: May 2010 Contact: Marek Lindner lindner_marek@yahoo.de Description: Displays the table of all batman nodes (in range) and the link quality towards them. Each line contains the following values: 1 - originator 2 - TQ (transmit quality) value of originator 3 - best next hop towards originator 4 - outgoing iface to reach best next hop 5 - list of alternative best next hops

Hi Marek

This is something i already said in private, but i think it is going to be a problem.

From Documentation/filesystems/sysfs.txt

Attributes ~~~~~~~~~~

Attributes can be exported for kobjects in the form of regular files in the filesystem. Sysfs forwards file I/O operations to methods defined for the attributes, providing a means to read and write kernel attributes.

Attributes should be ASCII text files, preferably with only one value per file. It is noted that it may not be efficient to contain only one value per file, so it is socially acceptable to express an array of values of the same type.

Mixing types, expressing multiple lines of data, and doing fancy formatting of data is heavily frowned upon. Doing these things may get you publically humiliated and your code rewritten without notice.

I expect that we have a problem here. My guess is some of these files are going to have to move back into proc. Use sysfs for configuration, where only single values are needed, and put all the tables of originators, HNA etc back in proc where fancy formatting of data is not frowned upon.

Andrew

Marek Lindner wrote:

Hi,

Greg asked us to provide an ABI documentation for the files creates in the sysfs tree. Since I am respsonsible for the sysfs stuff, I felt it was my turn to draft something. Please check the attachments and let me know whether you think we can send it or not.

I've read a little bit through the different descriptions and it sound good... for the reading situation. The problem is that it is nearly never clear that you control the behavior of batman-adv through that specific file. For example /sys/class/net/<iface>/batman-adv/mesh_iface - I think it is especially important for GregKH to see that it needed is now associated to the iface and we attach it to the mesh_iface through that file when he should give us some advice what virtual fs should be used for what kind of information.

Best regards, Sven