check_btrfs (nagios): make possible check all mounted btrfs

[Fantu]

Hi, thanks for this nagios/icinga plugin.
Actually seems possible to check only specified path.
Unfortunately this requires the creation of different checks for different volumes, it would be great to have the ability to do the check for all mounted btrfs volumes (if you don't specify the path) to have a single check that can be set quickly on many servers without having to do additional configurations based on how many volumes and on which paths.

[knorrie]

Hi! Yes, this is a very good idea. If there is no specific path provided as argument, we can just check all mounted filesystems. In fact, the other monitoring plugin example, the munin one, already does it that way, simply generate graphs for all mounted filesystems, So, I actually can't say why the nagios one doesn't...