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Date:   Tue, 14 Jul 2020 13:00:55 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     "Darrick J. Wong" <darrick.wong@oracle.com>
Cc:     Christoph Hellwig <hch@lst.de>, Dave Chinner <david@fromorbit.com>,
        Goldwyn Rodrigues <rgoldwyn@suse.de>,
        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: <20200714110055.GC16178@lst.de>
References: <20200713074633.875946-1-hch@lst.de> <20200713074633.875946-3-hch@lst.de> <20200713153920.GU7606@magnolia>
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On Mon, Jul 13, 2020 at 08:39:20AM -0700, Darrick J. Wong wrote:
> -ENOTBLK is already being used as a "magic" return code that means
> "retry this direct write as a buffered write".  Shouldn't we use that
> instead?
> 
> -EREMCHG was a private hack we put in XFS for the one case where a
> direct write had to be done through the page cache (non block-aligned
> COW), but maybe it's time we put that to rest since the rest of the
> world apparently thinks the magic fallback code is -ENOTBLK.

Sure, I can switch the error code.