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 id 1bgbK5-000J6Z-Qr; Sun, 04 Sep 2016 20:35:13 +0300
Subject: Re: Regression with revision 303970 (was kern.proc.pathname failure
 while booting from zfs)
To: Konstantin Belousov <kostikbel@gmail.com>
References: <CAMODbknGPaXR3=v-caacyigP5MdDgc9DKhAq=FMWh5=r7GzoDA@mail.gmail.com>
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 <b7e6ace7-ec52-4bdb-0185-ef6bcddb371e@FreeBSD.org>
 <20160904145103.GD83214@kib.kiev.ua>
Cc: Frederic Chardon <chardon.frederic@gmail.com>, freebsd-stable@FreeBSD.org, 
 freebsd-current@FreeBSD.org
From: Andriy Gapon <avg@FreeBSD.org>
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Date: Sun, 4 Sep 2016 20:33:52 +0300
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On 04/09/2016 17:51, Konstantin Belousov wrote:
> It is only masked when name cache has an entry for the vnode.  So sometimes
> vn_fullpath() should be broken even if no normalization is applied.

Yes, this is true.

> OTOH, classic filesystems like UFS do not have any other means to translate
> non-directory inode to name and parent at all, except the namecache hint.

In fact, this is true for ZFS as well.  While ZFS znodes have an attribute that
specifies a (single) parent, it's obviously unreliable for files, because a file
can be linked into multiple directories and then unlinked from a directory
specified by the attribute.

So, at the moment I do not have any good ideas on how to make this work.
Maybe trying to use the parent attribute and failing when it's inconsistent
would be good enough...


-- 
Andriy Gapon