Re: Selective Compression/Encryption

[Chris Mason <chris.mason@oracle.com>]

On Tue, 2008-12-09 at 09:59 -0500, Lee Trager wrote:
> Currently compression and I assume if encryption is implemented it is
> turned on or off during mount. There are however many times when a user may
> want to select which files/directories they want to compress or encrypt.
> This will also be helpful when implementing btrfs support in grub for
> example. We can say the disk can be compressed/encrypted except for /boot so 
> compression/encryption doesn't have to be implemented in grub.
> 
> I was thinking of adding this functionality to the userspace application
> btrfstune. The way I was thinking of doing this is when btrfstune +c is
> applied to a directory or file the directory(and all its contents) or
> file will always be compressed reguardless of how the filesystem is
> mounted. The opposite would happen when btrfstune -c is used.
> 

This was my plan, but btrfstune probably isn't the best program to do it
(the ext2 tune program is mostly aimed at the super block level things).

I think it would be better to make a setattr style program to call the
ioctls.  There is already a per file compression flag, and the code
should already be checking it.

-chris