2011-02-28 07:03:41

by Dave Young

[permalink] [raw]
Subject: ext2/3/4: punch support?

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?

--
Regards
dave


2011-02-28 13:16:56

by Josef Bacik

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

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,

Josef

2011-02-28 14:29:56

by Dave Young

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik <[email protected]> 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.

I know general knowledge about ext filesystem, but nearly new to ext4 code,
could you give some hint where to start?

--
Thanks
dave

2011-02-28 14:50:15

by Lukas Czerner

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On Mon, 28 Feb 2011, Dave Young wrote:

> On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik <[email protected]> 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.

Ext4 supports discard as well, actually batched discard support was
added into ext4 before xfs :)

Thanks!
-Lukas

>
> 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 [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2011-02-28 15:17:54

by Eric Sandeen

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On 2/28/11 8:29 AM, Dave Young wrote:
> On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik <[email protected]> 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...

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.

-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 [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2011-03-01 00:59:30

by Allison Henderson

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

Hi All,

I've actually already started on a patch set for punch hole support in ext4. I've sent them out on the ltc-fsdev mailing list for review. I had planned to spend another week or two running it through some more debug cases before sending it to the ext4 mailing list though.

Allison Henderson

[email protected] wrote on 02/28/2011 06:11:18 AM:

> Josef Bacik <[email protected]>
> Sent by: [email protected]
>
> 02/28/2011 06:11 AM
>
> To
>
> Dave Young <[email protected]>
>
> cc
>
> [email protected], Theodore Tso <[email protected]>, linux-
> [email protected], Linux Kernel Mailing List <[email protected]>
>
> Subject
>
> Re: ext2/3/4: punch support?
>
> 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,
>
> Josef
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2011-03-01 01:27:42

by Dave Young

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On Mon, Feb 28, 2011 at 11:17 PM, Eric Sandeen <[email protected]> wrote:
> On 2/28/11 8:29 AM, Dave Young wrote:
>> On Mon, Feb 28, 2011 at 9:11 PM, Josef Bacik <[email protected]> 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/[email protected]/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 [email protected]
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>



--
Regards
dave

2011-03-01 02:19:17

by Allison Henderson

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

Alrighty then, I can send it out a little early since people are interested. It should show up here soon. Any feedback is appreciated! :)

Allison Henderson

On 2/28/2011 6:32 PM, Dave Young wrote:
> On Tue, Mar 1, 2011 at 8:44 AM, Allison C Henderson<[email protected]> wrote:
>>
>> Hi All,
>>
>> I've actually already started on a patch set for punch hole support in ext4.
>> I've sent them out on the ltc-fsdev mailing list for review. I had planned
>> to spend another week or two running it through some more debug cases before
>> sending it to the ext4 mailing list though.
>
> Where can find your patch? should be sent to linux-ext4?
>
>>
>> [email protected] wrote on 02/28/2011 06:11:18 AM:
>>
>>> Josef Bacik<[email protected]>
>>> Sent by: [email protected]
>>>
>>> 02/28/2011 06:11 AM
>>>
>>> To
>>>
>>> Dave Young<[email protected]>
>>>
>>> cc
>>>
>>> [email protected], Theodore Tso<[email protected]>, linux-
>>> [email protected], Linux Kernel Mailing List
>>> <[email protected]>
>>>
>>> Subject
>>>
>>> Re: ext2/3/4: punch support?
>>>
>>> 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,
>>>
>>> Josef
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
>>> the body of a message to [email protected]
>>> More majordomo info at
>> http://vger.kernel.org/majordomo-info.html
>>
>
>
>



2011-03-01 02:26:06

by Dave Young

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On Tue, Mar 1, 2011 at 10:19 AM, Allison Henderson
<[email protected]> wrote:
> Alrighty then, I can send it out a little early since people are interested.  It should show up here soon.  Any feedback is appreciated! :)

Hi, top post is bad here, please don't do that.

>
> Allison Henderson
>
> On 2/28/2011 6:32 PM, Dave Young wrote:
>> On Tue, Mar 1, 2011 at 8:44 AM, Allison C Henderson<[email protected]>  wrote:
>>>
>>> Hi All,
>>>
>>> I've actually already started on a patch set for punch hole support in ext4.
>>>   I've sent them out on the ltc-fsdev mailing list for review.  I had planned
>>> to spend another week or two running it through some more debug cases before
>>> sending it to the ext4 mailing list though.
>>
>> Where can find your patch? should be sent to linux-ext4?
>>


--
Regards
dave

2011-03-01 03:12:23

by Allison Henderson

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On 2/28/2011 7:26 PM, Dave Young wrote:
> On Tue, Mar 1, 2011 at 10:19 AM, Allison Henderson
> <[email protected]> wrote:
>> Alrighty then, I can send it out a little early since people are interested. It should show up here soon. Any feedback is appreciated! :)
>
> Hi, top post is bad here, please don't do that.
>
>>
>> Allison Henderson
>>
>> On 2/28/2011 6:32 PM, Dave Young wrote:
>>> On Tue, Mar 1, 2011 at 8:44 AM, Allison C Henderson<[email protected]> wrote:
>>>>
>>>> Hi All,
>>>>
>>>> I've actually already started on a patch set for punch hole support in ext4.
>>>> I've sent them out on the ltc-fsdev mailing list for review. I had planned
>>>> to spend another week or two running it through some more debug cases before
>>>> sending it to the ext4 mailing list though.
>>>
>>> Where can find your patch? should be sent to linux-ext4?
>>>
>
>

Sorry about that, I'm still a little new here. I've just sent out what I have so far.
Please let me know if you have trouble with any of the patches. Thx!

Allison Henderson


2011-03-01 01:32:20

by Dave Young

[permalink] [raw]
Subject: Re: ext2/3/4: punch support?

On Tue, Mar 1, 2011 at 8:44 AM, Allison C Henderson <[email protected]> wrote:
>
> Hi All,
>
> I've actually already started on a patch set for punch hole support in ext4.
>  I've sent them out on the ltc-fsdev mailing list for review.  I had planned
> to spend another week or two running it through some more debug cases before
> sending it to the ext4 mailing list though.

Where can find your patch? should be sent to linux-ext4?

>
> [email protected] wrote on 02/28/2011 06:11:18 AM:
>
>> Josef Bacik <[email protected]>
>> Sent by: [email protected]
>>
>> 02/28/2011 06:11 AM
>>
>> To
>>
>> Dave Young <[email protected]>
>>
>> cc
>>
>> [email protected], Theodore Tso <[email protected]>, linux-
>> [email protected], Linux Kernel Mailing List
>> <[email protected]>
>>
>> Subject
>>
>> Re: ext2/3/4: punch support?
>>
>> 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,
>>
>> Josef
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
>> the body of a message to [email protected]
>> More majordomo info at
> http://vger.kernel.org/majordomo-info.html
>



--
Regards
dave