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From: Kyle Evans <kevans@freebsd.org>
Date: Tue, 22 Sep 2020 15:48:15 -0500
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Subject: Re: svn commit: r365643 - head/bin/cp
To: Alan Somers <asomers@freebsd.org>
Cc: src-committers <src-committers@freebsd.org>,
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On Fri, Sep 11, 2020 at 3:49 PM Alan Somers <asomers@freebsd.org> wrote:
>
> Author: asomers
> Date: Fri Sep 11 20:49:36 2020
> New Revision: 365643
> URL: https://svnweb.freebsd.org/changeset/base/365643
>
> Log:
>   cp: fall back to read/write if copy_file_range fails
>
>   Even though copy_file_range has a file-system agnostic version, it still
>   fails on devfs (perhaps because the file descriptor is non-seekable?) In
>   that case, fallback to old-fashioned read/write. Fixes
>   "cp /dev/null /tmp/null"
>

Hi,

Any objection to adding a quick UPDATING entry for this? I'm seeing
occasional reports of this breakage as recent as today on IRC from
folks that were a little bit thrown off by this because it throws up
fairly far into the build and looks like a stand build regression
instead of a cp regression.

Thanks,

Kyle Evans