From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/1] hfsplus: skip unnecessary volume header sync
Date: Thu, 17 Jul 2014 13:59:29 -0700
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Cc: <hch@infradead.org>, <linux-fsdevel@vger.kernel.org>,
	Vyacheslav Dubeyko <slava@dubeyko.com>,
	Fabian Frederick <fabf@skynet.be>
To: <sougata@tuxera.com>
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On Thu, 17 Jul 2014 19:32:42 +0300 Sougata Santra <sougata@tuxera.com> wrote:

> hfsplus_sync_fs always updates volume header information to disk with every
> sync. This causes problem for systems trying to monitor disk activity to
> switch them to low power state.

Please fully describe these "problems"?  I'm guessing that the fs will
write the volume header even if it didn't change, so a sync operation
against a completely clean fs still performs a physical write.  But I'd
prefer not to have to guess!

> Also hfsplus_sync_fs is explicitly called
> from mount/unmount, which is unnecessary. During mount/unmount we only want
> to set/clear volume dirty sate.