Messages in this thread | | | Date | Tue, 1 Mar 2011 09:27:40 +0800 | Subject | Re: ext2/3/4: punch support? | From | Dave Young <> |
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On Mon, Feb 28, 2011 at 11:17 PM, Eric Sandeen <sandeen@redhat.com> wrote: > On 2/28/11 8:29 AM, Dave Young wrote: >> On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik <josef@redhat.com> wrote: >>> On Mon, Feb 28, 2011 at 03:03:40PM +0800, Dave Young wrote: >>>> Hi, josef and ext guys >>>> >>>> Do you have any plan with ext4 hole punching support? And the >>>> fallocate for ext2/3? >>>> >>>> What's the obstacle to work on this? could someone tell the status of >>>> this issue? >>> >>> There is no obstacle, just nobody has bothered to do it. If you want to do it >>> go for it. Thanks, >> >> Yes, I want to do some kvm image space discard stuff, >> I use ext4 as my filesystem, but currently only xfs support something >> like trim/discard. > > As Lukas said, ext4 & ext3 support various forms of trim/discard already. > > But that's different from punch...
Lukas and Eric, thanks for pointing out, I think I means punch, although trim/discard is useful as well in guest side.
> > And as for fallocate on ext3, you need somewhere to put the metadata to indicate a block is allocated but not written. This was a lot more straightforward for ext4, since it describes a large range of blocks with a single extent structure.
As for ext3 fallocate, I found some interesting discuss: http://www.mail-archive.com/linux-ext4@vger.kernel.org/msg02371.html
Andrew, do you know what's the status of above issue?
> > -Eric > >> I know general knowledge about ext filesystem, but nearly new to ext4 code, >> could you give some hint where to start? >> >> -- >> Thanks >> dave >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >
-- Regards dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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