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Date: Wed, 19 Sep 2001 19:30:55 -0400 (EDT)
From: Alexander Viro <viro@math.psu.edu>
To: Andrea Arcangeli <andrea@suse.de>
cc: Linus Torvalds <torvalds@transmeta.com>,
        Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Linux 2.4.10-pre11
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On Thu, 20 Sep 2001, Andrea Arcangeli wrote:

> On Wed, Sep 19, 2001 at 05:17:23PM -0400, Alexander Viro wrote:
> > fsync_dev() is not needed for raw devices or swap.  It _is_ needed for
> > file access.
> 
> then what's the difference between raw devices and swap.

Keep in mind that at some point we may want to add exclusions - e.g.
"swapon() messing with block_size when accidentially called for mounted
fs" problem can be easily solved that way - that's probably the
simplest way to deal with it.  Ditto for RAID vs. filesystem - current
code for that is ugly and not too reliable.
 
> And there's reason we should we avoid the fsync_dev with the raw devices
> and swap.

Umm... Not doing unnecessary work?  Semantics of releasing a block device
depends on the kind of use.  BTW, I'm less than sure that fsync_dev() is
the right thing for file access now that you've got that in pagecache -
__block_fsync() seems to be more correct thing to do.

> I just found it an useless complication.

<shrug> in the eye of beholder...

/me goes to get some sleep.