From: Olaf van der Spek <olafvdspek@gmail.com>
Subject: Re: Atomic file data replace API
Date: Tue, 28 Dec 2010 23:58:21 +0100
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Cc: "Ted Ts'o" <tytso@mit.edu>,
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To: Ric Wheeler <rwheeler@redhat.com>
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On Tue, Dec 28, 2010 at 11:36 PM, Ric Wheeler <rwheeler@redhat.com> wrote:
> I think that various developers have answered this for you several times.

Not really, unfortunately. Haven't seen a single link to code that
shows how to do it properly.
Temp file, fsync, rename is often mentioned but that skips the
preserving meta-data part and this part, which you also skipped:
One use case would be updating a file in a safe way when you have
write access to that file but not to anything else.

> As a suggestion, if you are not a kernel developer, show us specifically a
> bit of application code that demonstrates something that you want to have
> work differently.

I will.

> Test it with power failure (buy an external e-sata or USB disk and pull
> power while running your app).

The current code?
I think I'll use a VM instead of an external disk. ;)

Olaf