Re: [PATCH] btrfs: remove pointless debugfs interface

[Eric Sandeen <sandeen@redhat.com>]

On 8/31/16 2:08 PM, David Sterba wrote:
> On Wed, Aug 31, 2016 at 10:13:49AM -0500, Eric Sandeen wrote:
>> A /sys/kernel/debug/btrfs/test file was added nearly
>> two and a half years ago, but it serves no purpose;
> 
> It does. Introduced in 1bae30982bc86ab66d61ccb6e22792593b45d44d says
> something about helping developers to easily export information from the
> filesystem, to aid debugging. Writing the debugfs support code is not
> obviously trivial, so it's idling in the source. Exporing a new value is
> as easy as copy and update 3 lines of code. If you have no use for it,
> fine.

I had thought that Documentation/filesystems/debugfs.txt would suffice,
but if you keep stuff lying around in btrfs just in case somebody needs
to export a global variable in the future, I suppose that's cool too.  ;)

>> it stores and returns a value, but nothing in the btrfs
>> code uses this value in any way.  There are no other btrfs
>> files in this debugfs dir.
>>
>> This was brought to my attention because it is world-writable;
>> it is the only such file under /sys/kernel/debug, and without
>> knowledge of its purpose, some users were alarmed by this.
> 
> So let's fix the permissions.

*shrug* ok.

-Eric