Having troubles to disable inline extents

Having troubles to disable inline extents

[Rebraca Dejan (BSOT/PJ-ES1-Bg)]

Hi,

We are trying to add support for BTRFS in our project, so we started to examine this filesystem.
For the moment, we don't want inline extents for our tests, but we have difficulties to turn them off. I'm using 'max_inline=0' mount option to disable them, but I still see them for small files (< 50 Bytes) using FS_IOC_FIEMAP ioctl. Kernel log when executing mount:
[11051.642976] BTRFS info (device loop0): max_inline at 0
[11051.642978] BTRFS info (device loop0): disk space caching is enabled
[11051.642979] BTRFS info (device loop0): has skinny extents

Environment:
- 4.15.0-96-generic #97~16.04.1-Ubuntu SMP Wed Apr 1 03:03:31 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
- btrfs-progs v4.4

I would really appreciate your support on this.
Tnx.

Best regards,

Dejan Rebraca
BSOT/PJ-ES1-Bg

Re: Having troubles to disable inline extents

[Qu Wenruo]

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On 2020/6/16 下午9:41, Rebraca Dejan (BSOT/PJ-ES1-Bg) wrote:
> Hi,
> 
> We are trying to add support for BTRFS in our project, so we started to examine this filesystem.
> For the moment, we don't want inline extents for our tests, but we have difficulties to turn them off. I'm using 'max_inline=0' mount option to disable them, but I still see them for small files (< 50 Bytes) using FS_IOC_FIEMAP ioctl. Kernel log when executing mount:

max_inline only affects new writes.
So existing inlined extent won't be affected.

You need to defrag such small files to convert them back to regular extents.

Thanks,
Qu

> [11051.642976] BTRFS info (device loop0): max_inline at 0
> [11051.642978] BTRFS info (device loop0): disk space caching is enabled
> [11051.642979] BTRFS info (device loop0): has skinny extents
> 
> Environment:
> - 4.15.0-96-generic #97~16.04.1-Ubuntu SMP Wed Apr 1 03:03:31 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
> - btrfs-progs v4.4
> 
> I would really appreciate your support on this.
> Tnx.
> 
> Best regards,
> 
> Dejan Rebraca
> BSOT/PJ-ES1-Bg
> 


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RE: Having troubles to disable inline extents

[Rebraca Dejan (BSOT/PJ-ES1-Bg)]

Ok, I understand.

And is there a way to disable them during filesystem creation (e.g. some option in mkfs.btrfs)?

Thanks,
Dejan

-----Original Message-----
From: Qu Wenruo <quwenruo.btrfs@gmx.com> 
Sent: utorak, 16. jun 2020. 15:45
To: Rebraca Dejan (BSOT/PJ-ES1-Bg) <Dejan.Rebraca@rs.bosch.com>; linux-btrfs@vger.kernel.org
Subject: Re: Having troubles to disable inline extents



On 2020/6/16 下午9:41, Rebraca Dejan (BSOT/PJ-ES1-Bg) wrote:
> Hi,
> 
> We are trying to add support for BTRFS in our project, so we started to examine this filesystem.
> For the moment, we don't want inline extents for our tests, but we have difficulties to turn them off. I'm using 'max_inline=0' mount option to disable them, but I still see them for small files (< 50 Bytes) using FS_IOC_FIEMAP ioctl. Kernel log when executing mount:

max_inline only affects new writes.
So existing inlined extent won't be affected.

You need to defrag such small files to convert them back to regular extents.

Thanks,
Qu

> [11051.642976] BTRFS info (device loop0): max_inline at 0 
> [11051.642978] BTRFS info (device loop0): disk space caching is 
> enabled [11051.642979] BTRFS info (device loop0): has skinny extents
> 
> Environment:
> - 4.15.0-96-generic #97~16.04.1-Ubuntu SMP Wed Apr 1 03:03:31 UTC 2020 
> x86_64 x86_64 x86_64 GNU/Linux
> - btrfs-progs v4.4
> 
> I would really appreciate your support on this.
> Tnx.
> 
> Best regards,
> 
> Dejan Rebraca
> BSOT/PJ-ES1-Bg
> 

Re: Having troubles to disable inline extents

[Nikolay Borisov]

On 16.06.20 г. 16:57 ч., Rebraca Dejan (BSOT/PJ-ES1-Bg) wrote:
> Ok, I understand.
> 
> And is there a way to disable them during filesystem creation (e.g. some option in mkfs.btrfs)?

No, this is a mount option, not persisted on-disk.

<snip>

RE: Having troubles to disable inline extents

[Rebraca Dejan (BSOT/PJ-ES1-Bg)]

Understood.
Thanks for your support.

Dejan

-----Original Message-----
From: Nikolay Borisov <nborisov@suse.com> 
Sent: utorak, 16. jun 2020. 16:57
To: Rebraca Dejan (BSOT/PJ-ES1-Bg) <Dejan.Rebraca@rs.bosch.com>; Qu Wenruo <quwenruo.btrfs@gmx.com>; linux-btrfs@vger.kernel.org
Subject: Re: Having troubles to disable inline extents



On 16.06.20 г. 16:57 ч., Rebraca Dejan (BSOT/PJ-ES1-Bg) wrote:
> Ok, I understand.
> 
> And is there a way to disable them during filesystem creation (e.g. some option in mkfs.btrfs)?

No, this is a mount option, not persisted on-disk.

<snip>