On Mon, Feb 28, 2011 at 11:17 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote: > On 2/28/11 8:29 AM, Dave Young wrote: >> On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik <josef@xxxxxxxxxx> 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. ÂIf you want to do it >>> go for it. ÂThanks, >> >> 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. ÂThis 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@xxxxxxxxxxxxxxx/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@xxxxxxxxxxxxxxx >> More majordomo info at Âhttp://vger.kernel.org/majordomo-info.html > > -- Regards dave -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
