On Tue, Dec 01, 2020 at 10:02:06AM +0000, Christoph Hellwig wrote: > On Mon, Nov 30, 2020 at 07:37:16PM -0800, Darrick J. Wong wrote: > > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > > > Add a copy_file_range handler to XFS so that we can accelerate file > > copies with reflink when the source and destination ranges are not > > block-aligned. We'll use the generic pagecache copy to handle the > > unaligned edges and attempt to reflink the middle. > > Isn't this something we could better handle in the VFS (or a generic > helper) so that all file systems that support reflink could benefit? Maybe. I don't know if it's universally true that all filesystems should fall back to reflinking the middle range and pagecache copying the unaligned start/end. The other thing is that xfs can easily support reflink on rtextsize > 1, but that adds the requirement that we set i_blocksize to a larger value than we do now... or find some other way to convey allocation unit size to a generic version of the fallback. OTOH that's pretty easy to do from xfs_copy_file_range. --D
