On Mon, Feb 14, 2011 at 10:17:26AM +0800, Tao Ma wrote: > Hi Christoph, > On 02/14/2011 02:42 AM, Christoph Hellwig wrote: > >On the 4th of January we saw the release of Linux 2.6.37, which contains a > >large XFS update: > > > > 67 files changed, 1424 insertions(+), 1524 deletions(-) > > > >User visible changes are the new XFS_IOC_ZERO_RANGE ioctl which allows > >to convert already allocated space into unwritten extents that return > >zeros on a read, > would you mind describing some scenario that this ioctl can be used. I am > just wondering whether ocfs2 can implement it as well. Zeroing a file without doing IO or having to punch out the blocks already allocated to the file. In this case, we had a couple of different people in cloud storage land asking for such functionality to optimise record deletion be avoiding disruption of their preallocated file layouts as a punch-then-preallocate operation does. If you you have some kind of use for it in ocfs2, then implementing the XFS ioctl is not the correct thing to do - using the fallocate patch I've had sitting around (since about 15min after creating the XFS ioctl) is most likely the right way to proceed.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
