Re: Errors on newly created file system

[Ferry Toth <fntoth@gmail.com>]

Hi

Op 24-04-2025 om 13:31 schreef Ferry Toth:
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> Op donderdag 24 april 2025 01:24:23 CEST schreef Qu Wenruo:
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> >
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> > 在 2025/4/24 01:36, Ferry Toth 写道:
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> > > Op woensdag 23 april 2025 00:00:36 CEST schreef Qu Wenruo:
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> > >
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> > [...]
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> > >
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> > >  > > Yocto users on Scarthgap (5.0 LTS) with version 6.7.1 may 
> copy the
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> > >
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> > >  > > recipe meta/recipes-devtools/btrfs-tools/btrfs-tools_6.13.bb from
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> > >
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> > >  > > walnascar or 6.14 from master. If they are building 
> additional tools
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> > >
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> > >  > > that use headers from this package like btrfs-compsize these 
> may break.
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> > >
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> > >  > >> Thanks,
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> > >
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> > >  > >> Qu
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> > >
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> > >
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> > > While here, am I right that we can not generate the rootfs with
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> > > compression on?
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> > >
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> > >
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> > > Reason I ask is, Yocto of course builds the rootfs and than has
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> > > mkfs.btrfs create the image. But it runs as unprivileged user, so can
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> > > not do mount.
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> > >
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> > > And then can not do defrag.
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> >
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> > We have this feature recently thanks to Mark!
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> >
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> > In the latest release v6.13, there is a new option "--compress" 
> added to
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> > mkfs.btrfs, which must be used with "--rootdir".
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> >
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> > And the result is exactly what you expected, mkfs.btrfs will try to
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> > compress the file extents at runtime.
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> > For uncompressible data, it will detect at the beginning and 
> fallback to
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> > uncompressed data instead, exactly like the kernel.
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>
> That is great, thanks!
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>
> > But considering how new this feature this, it will be appreciated if
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> > Yocto guys can do some extra testing to make sure nothing is broken.
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> > (Normally a btrfs check after the mkfs will be good enough)
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> >
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>
> I will test this.
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>
> In the meanwhile I found another problem (and I am not the first it 
> seems see
>
> /https://stackoverflow.com/questions/79475262/yocto-root-filesystem-ownership-issue/79590289#79590289/ 
> <https://stackoverflow.com/questions/79475262/yocto-root-filesystem-ownership-issue/79590289#79590289>)
>
>
> Yocto uses pseudo to fake root ownership. Even though the directory to 
> be copied into the new fs is owned by an unprivileged user inside the 
> btrfs image the files are owned by root, when created by mkfs.ext4 and 
> mkfs.btrfs.
>
>
> Except with newer mkfs.btrfs (I tested using 6.13) the files are owned 
> by the unprivileged user.
>
>
> The result is, the image will not boot correctly.
>
>
I found more about this issue here

https://lore.kernel.org/yocto/tRtu.1740682678597454399.5171@lists.yoctoproject.org/T/#m5de0afa17d2c0f640e86ffe67e0d74aea467fd5b

> > Thanks,
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> > Qu
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