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Date: Tue, 15 Oct 2019 01:01:34 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Pingfan Liu <kernelfans@gmail.com>
Subject: Re: [PATCH] xfs: introduce "metasync" api to sync metadata to fsblock
Message-ID: <20191015080134.GC3055@infradead.org>
References: <1570977420-3944-1-git-send-email-kernelfans@gmail.com>
 <20191014084027.GA3593@infradead.org> <20191015015620.GA14327@mypc>
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Cc: linux-xfs@vger.kernel.org, Eric Sandeen <esandeen@redhat.com>,
 "Darrick J. Wong" <darrick.wong@oracle.com>,
 Christoph Hellwig <hch@infradead.org>, Dave Chinner <dchinner@redhat.com>,
 linuxppc-dev@lists.ozlabs.org, Hari Bathini <hbathini@linux.ibm.com>
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On Tue, Oct 15, 2019 at 09:56:20AM +0800, Pingfan Liu wrote:
> Agree. For the consistency of the whole fs, we need grub to be aware of
> log. While this patch just assumes that files accessed by grub are
> known, and the consistency is forced only on these files.
> > get by freezing and unfreezing the file system using the FIFREEZE and
> > FITHAW ioctls.  And if my memory is serving me correctly Dave has been
> freeze will block any further modification to the fs. That is different
> from my patch, which does not have such limitation.

So you freeze and immediately unfreeze.