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Date:   Fri, 19 May 2023 01:10:16 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     David Howells <dhowells@redhat.com>
Cc:     Jens Axboe <axboe@kernel.dk>, Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Christoph Hellwig <hch@lst.de>, linux-erofs@lists.ozlabs.org,
        linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org
Subject: Re: [PATCH v20 05/32] splice: Make splice from a DAX file use
 direct_splice_read()
Message-ID: <ZGcu6GVxOgYfy8x9@infradead.org>
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 <20230519074047.1739879-6-dhowells@redhat.com>
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On Fri, May 19, 2023 at 08:40:20AM +0100, David Howells wrote:
> +#ifdef CONFIG_FS_DAX
> +	if (IS_DAX(in->f_mapping->host))

No need for the ifdef.  IS_DAX is compile-time false if CONFIG_FS_DAX
is not set.

A comment on why we're doing this in the code would probably be useful
as well.