Re: fdatasync(2) is also there (was: intermediate summary of ext3-2.4-0.9.4 thread)

From: Mike Castle <dalgoda@ix.netcom.com>
To: linux-kernel@vger.kernel.org
Cc: Alexander Viro <viro@math.psu.edu>
Subject: Re: fdatasync(2) is also there (was: intermediate summary of ext3-2.4-0.9.4 thread)
Date: Sat, 4 Aug 2001 17:28:40 -0700	[thread overview]
Message-ID: <20010804172840.L437@thune.mrc-home.com> (raw)
In-Reply-To: <20010804054043.F16516@emma1.emma.line.org>

On Sat, Aug 04, 2001 at 05:40:43AM +0200, Matthias Andree wrote:
> How portable is fsync()ing the directory?

It is as portable as assuming that the directory entries are synced during
fsync().

> 
> How USEFUL is it to the application if all other boxen fsync() the
> directory entries along with the file?

Except, you can NOT guarantee that this is the case.  The spec does NOT
require it.

> You want to sync the files, but the directory only after you created all
> of the files? Use fdatasync(2) for the files - it doesn't flush meta
> data, then sync the directory. It's POSIX, it's SUS v2.

Is fsync(dir) what you mean here?

mrc
-- 
     Mike Castle      dalgoda@ix.netcom.com      www.netcom.com/~dalgoda/
    We are all of us living in the shadow of Manhattan.  -- Watchmen
fatal ("You are in a maze of twisty compiler features, all different"); -- gcc