Dave Chinner sent in the XFS feature pull request for the Linux 3.18 kernel.

Changes for the XFS file-system with Linux 3.18 include:

- Various cleanups
- Log recovery debug hooks
- Seek hole/data implementation merge
- Extent shift rework to fix collapse range bugs
- Various sparse warning fixes
- Log recovery transaction processing rework to fix use after free bugs
- Metadata buffer IO infrastructuer rework to ensure all buffers under IO have valid reference counts
- Various fixes for ondisk flags, writeback and zero range corner cases

More information on the XFS changes for Linux 3.18 can be found via the pull request.