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Date:   Mon, 13 Jul 2020 18:09:57 +0200
From:   David Sterba <dsterba@suse.cz>
To:     Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc:     Christoph Hellwig <hch@lst.de>, Dave Chinner <david@fromorbit.com>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        Naohiro Aota <naohiro.aota@wdc.com>,
        Johannes Thumshirn <jth@kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        cluster-devel@redhat.com, linux-ext4@vger.kernel.org,
        linux-xfs@vger.kernel.org
Subject: Re: [PATCH 2/2] iomap: fall back to buffered writes for invalidation
 failures
Message-ID: <20200713160957.GM3703@twin.jikos.cz>
Reply-To: dsterba@suse.cz
Mail-Followup-To: dsterba@suse.cz, Goldwyn Rodrigues <rgoldwyn@suse.de>,
        Christoph Hellwig <hch@lst.de>, Dave Chinner <david@fromorbit.com>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        Naohiro Aota <naohiro.aota@wdc.com>,
        Johannes Thumshirn <jth@kernel.org>,
        Matthew Wilcox <willy@infradead.org>, linux-btrfs@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, cluster-devel@redhat.com,
        linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org
References: <20200713074633.875946-1-hch@lst.de>
 <20200713074633.875946-3-hch@lst.de>
 <20200713122050.okus7qlampk5ysyb@fiona>
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On Mon, Jul 13, 2020 at 07:20:50AM -0500, Goldwyn Rodrigues wrote:
> On  9:46 13/07, Christoph Hellwig wrote:
> > Failing to invalid the page cache means data in incoherent, which is
> > a very bad state for the system.  Always fall back to buffered I/O
> > through the page cache if we can't invalidate mappings.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Thanks. This will help btrfs. The current next tree contains the iomap
> changes I recomended and would need to be reverted in order to
> incorporate this. Once this is in the next tree I will (re)format the
> btrfs iomap dio patches.

Patches in next don't need to be reverted, if you put together a branch
with any iomap or other prep patches + btrfs iomap-dio I'll replace it
in the for-next snapshot I push.