Re: [RFC, PATCH 0/2] fiemap: filesystem free space mapping

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Wed, Oct 24, 2012 at 07:47:17AM -0400, Chris Mason wrote:
> I'm all for it in the main fiemap call, it makes much more sense for the
> users I think.

How so?  Current fiemap is a per-inode information, Daves new call is
per-fs.  Making one a flag of another is a gross user interface.  In
addition we're bound to get issue where filesystems fail to wire up
fiemap to the tons of different iops just for this operation, or
accidentally wire up "real" fiemap to things like special files or
pipes.

Btw, I'd like t orestate that I really love to see this functionality in
the VFS, just not multiplexed over FIEMAP.