Hi Dave, > 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. Thanks for the info. yeah, ocfs2 is also used to host images in some cloud computing environment. So It looks helpful for us too. > > 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.... yeah, Josef has added the punching hole in fallocate, so I guess another parameter for keeping the blocks during hole punching should be enough for us. :) Regards, Tao -- 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
