From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] exofs: exofs_file_fsync correctness
Date: Tue, 1 Jun 2010 17:47:18 +0200
Message-ID: <20100601154718.GA16412@lst.de>
References: <20100531100927.GA11149@lst.de> <4C0527AF.6090502@panasas.com> <20100601153414.GA15889@lst.de> <4C0529FE.6030901@panasas.com>
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Cc: Christoph Hellwig <hch@lst.de>, linux-fsdevel@vger.kernel.org,
	open-osd <osd-dev@open-osd.org>
To: Boaz Harrosh <bharrosh@panasas.com>
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On Tue, Jun 01, 2010 at 06:40:46PM +0300, Boaz Harrosh wrote:
> >> +	struct writeback_control wbc = {
> >> +		.sync_mode = WB_SYNC_ALL,
> >> +		.nr_to_write = LONG_MAX,
> > 
> > By setting a nr_to_write you still write out data (at least in theory).
> > 
> 
> So when do I also sync the data? is that done for me at the VFS layer?

You never have to.  vfs_fsync_range does the data writeout for you.

> > I'd recommend just copying the code from generic_file_fsync..
> > 
> 
> I was actually mimicking the code from nfs/write.c which has similar
> semantics as mine.

nfs code has no good reason to do that, at least when called from
->fsync.

> And if so then I'll need to not reuse the above in .flush

I would recommend keeping the ->flush code separate.