Re: subvolume list as user?

[Hans van Kranenburg <hans.van.kranenburg@mendix.com>]

On 09/16/2017 02:39 PM, Hans van Kranenburg wrote:
> On 09/16/2017 11:45 AM, Ulli Horlacher wrote:
>> Every user can create subvolumes (and root cannot prevent it!).
>> But how can a user list these subvolumes?
>>
>> tux@xerus:/test/tux: btrfs subvolume create test
>> Create subvolume './test'
> 
> From your other posts I don't quickly get if you actually do want to
> have this possible, or accept that it's currently like that and try to
> do damage control by having users also remove their things again.
> 
> Actually, if you don't want this I think it's quite easily to patch your
> kernel with one or two lines of code to disallow it.
> 
>> tux@xerus:/test/tux: btrfs subvolume list .
>> ERROR: can't perform the search - Operation not permitted
> 
> Yes, because the SEARCH ioctl only allows root to directly query any of
> the filesystem metadata from kernel memory. subvolume list uses this
> SEARCH ioctl to find it's info.

its! Argh! D:

-- 
Hans van Kranenburg