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On 17:44 Sat 05 Mar , Ciaran McCreesh wrote: |
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> On Sat, 5 Mar 2011 18:41:46 +0100 |
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> Constanze Hausner <constanze@g.o> wrote: |
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> > > You're requiring special package manager behaviour if that flag is |
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> > > set? |
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> > |
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> > I'm requiring, that the package manager preserves the xattrs, when |
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> > stripping the binary and when moving it from the sandbox to the |
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> > live-fs. |
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> |
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> Currently we've got wording in PMS forbidding anything from relying |
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> upon xattrs being preserved correctly, since that's what Portage did |
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> when we wrote it. So if you're looking to change that, you'll need to |
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> EAPI control it. |
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Yes, there would be the need for a new EAPI, if the caps should be set |
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from src_install and therefore need to be preserved by the PMS. |
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As long as there is no such garantee one could use the eclass to set the |
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caps from pkg_postinst. I know it's really ugly, but it would be a |
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start. Otherwise we will never be able to use caps. |
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|
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> But it's not as simple as just requiring attributes to be preserved in |
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> future EAPIs, since: |
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> |
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> * some xattrs are fs specific |
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> |
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> * some xattrs (selinux?) can't be copied |
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I said something different than I thought, sorry. I only thought of the |
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caps and not other kinds of xattr, as I only require caps to be |
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preserved. |
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Caps do either work on a fs or they don't and they can be copied. |
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|
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> * some filesystems don't support xattrs at all, and the package manager |
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> needs to support installing to them, even if the user is building on |
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> a filesystem that does support it |
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That's true, additionaly even if the fs is able to support xattr, there |
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are kernel options, which need to be set. I agree with you, that that's |
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a huge problem. We need to have a good fallback mechanism. |
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|
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Zac metioned that we could have three modes for movefile: |
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1) no caps |
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2) tolerant mode, which does not fail if caps could not be copied |
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3) strict mode, which fails if caps can't be copied |
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|
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ferringb metioned some kind of marker with which one can indicate xattr |
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support. |
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|
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While GSoC I was not able to come up with a good fallback mechanism. |
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I'm going to give the new ideas some thought over the week and hopefully |
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come up with something good :). |
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|
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> * tar and xattrs is a massive problem, so how do binaries work? |
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tar can be patched to support xattrs. If we want to use caps, we will |
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have to apply those patches too. (iirc Fedora already uses such |
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patches). |
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|
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> I think it'd help if you provided a description of how all the above |
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> (plus the other issues that I've forgotten about) can be handled. |
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I hope I cleared things up at least a bit :). |
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|
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Cheers, |
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constanze |