GFS2 To Support Hole-Punching With Linux 4.16

The GFS2 file-system with the upcoming Linux 4.16 kernel cycle will add hole-punching support.

Since 2010 the Linux kernel has offered a standardized interface for deallocating file space from within a file, a.k.a. hole punching, and many Linux file-systems have supported this FALLOC_FL_PUNCH_HOLE behavior for fallocate() since the early Linux 3.x days but with Linux 4.16 comes the support for the Global File-System 2. This support for punching holes in files is commonly used for virtual disks by VMs backed by sparse files.

Landing within GFS2's -next Git tree is their FALLOC_FL_PUNCH_HOLE bits as the main feature being added for GFS2 in this next kernel cycle. Their next tree also has an improved non-recursive delete algorithm and other minor code enhancements.