Re: [PATCH] btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSION

[Christoph Hellwig <hch@lst.de>]

On Thu, Apr 23, 2009 at 10:00:55AM -0400, Chris Ball wrote:
> Hi Christoph,
> 
>    > Add support for the standard attributes set via chattr and read
>    > vis lsattr.  Currently we store the attributes in the flags value
>    > in the btrfs inode, but I wonder whether we should split it into
>    > two so that we don't have to keep converting between the two
>    > formats.
> 
> Any thoughts on how best to add support for setting the custom btrfs
> flags (nodatasum/nodatacow/nocompress) via an ioctl?  Is it possible
> to reuse FS_IOC_SETFLAGS for these too, or do we need a new ioctl?
> If we need a new one, any preference between an ioctl per flag vs.
> a single ioctl that accepts a new set of flags?

I think adding them here is a good idea.  In fact nocompress already
has a flag assigned, I just didn't want to put it in without broader
consultation first as it's not used yet in any mainline code.