From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [RFC PATCH] fpathconf() for fsync() behavior
Date: Thu, 23 Apr 2009 07:11:47 -0400
Message-ID: <20090423111147.GC4833@infradead.org>
References: <20090423001257.GA16540@shell>
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Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Chris Mason <chris.mason@oracle.com>,
	Theodore Tso <tytso@mit.edu>,
	Eric Sandeen <sandeen@redhat.com>,
	Ric Wheeler <rwheeler@redhat.com>
To: Valerie Aurora Henson <vaurora@redhat.com>
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On Wed, Apr 22, 2009 at 08:12:57PM -0400, Valerie Aurora Henson wrote:
> In the default mode for ext3 and btrfs, fsync() is both slow and
> unnecessary for some important application use cases - at the same
> time that it is absolutely required for correctness for other modes of
> ext3, ext4, XFS, etc.  If applications could easilyl distinguish
> between the two cases, they would be more likely to be correct and
> fast.
> 
> How about an fpathconf() variable, something like _PC_ORDERED?  E.g.:

Before we add any new fpathconf varibale we need a reall (f)pathconf(at)
syscall so that the fs driver can exposed it's characteristics, having
to replicate that information to glibc especially for something required
for data integrity is a receipe for a desaster.