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References: <20211109083309.584081-1-hch@lst.de> <20211109083309.584081-25-hch@lst.de>
In-Reply-To: <20211109083309.584081-25-hch@lst.de>
From:   Dan Williams <dan.j.williams@intel.com>
Date:   Tue, 23 Nov 2021 18:52:13 -0800
Message-ID: <CAPcyv4iRUDaT4rrLYhGrJB-zt9B-bGGoVW3wYoUnePRxx58Fdw@mail.gmail.com>
Subject: Re: [PATCH 24/29] xfs: use xfs_direct_write_iomap_ops for DAX zeroing
To:     Christoph Hellwig <hch@lst.de>
Cc:     Mike Snitzer <snitzer@redhat.com>, Ira Weiny <ira.weiny@intel.com>,
        device-mapper development <dm-devel@redhat.com>,
        linux-xfs <linux-xfs@vger.kernel.org>,
        Linux NVDIMM <nvdimm@lists.linux.dev>,
        linux-s390 <linux-s390@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-erofs@lists.ozlabs.org,
        linux-ext4 <linux-ext4@vger.kernel.org>,
        virtualization@lists.linux-foundation.org
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On Tue, Nov 9, 2021 at 12:34 AM Christoph Hellwig <hch@lst.de> wrote:
>
> While the buffered write iomap ops do work due to the fact that zeroing
> never allocates blocks, the DAX zeroing should use the direct ops just
> like actual DAX I/O.
>

I always wondered about this, change looks good to me.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_iomap.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 8cef3b68cba78..704292c6ce0c7 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -1324,7 +1324,7 @@ xfs_zero_range(
>
>         if (IS_DAX(inode))
>                 return dax_zero_range(inode, pos, len, did_zero,
> -                                     &xfs_buffered_write_iomap_ops);
> +                                     &xfs_direct_write_iomap_ops);
>         return iomap_zero_range(inode, pos, len, did_zero,
>                                 &xfs_buffered_write_iomap_ops);
>  }
> @@ -1339,7 +1339,7 @@ xfs_truncate_page(
>
>         if (IS_DAX(inode))
>                 return dax_truncate_page(inode, pos, did_zero,
> -                                       &xfs_buffered_write_iomap_ops);
> +                                       &xfs_direct_write_iomap_ops);
>         return iomap_truncate_page(inode, pos, did_zero,
>                                    &xfs_buffered_write_iomap_ops);
>  }
> --
> 2.30.2
>