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Date:   Fri, 28 Feb 2020 07:25:24 -0800
From:   "Darrick J. Wong" <darrick.wong@oracle.com>
To:     Ritesh Harjani <riteshh@linux.ibm.com>
Cc:     linux-ext4@vger.kernel.org, jack@suse.cz, tytso@mit.edu,
        adilger.kernel@dilger.ca, linux-fsdevel@vger.kernel.org,
        hch@infradead.org, cmaiolino@redhat.com, david@fromorbit.com
Subject: Re: [PATCHv5 3/6] ext4: Move ext4 bmap to use iomap infrastructure.
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On Fri, Feb 28, 2020 at 02:56:56PM +0530, Ritesh Harjani wrote:
> ext4_iomap_begin is already implemented which provides ext4_map_blocks,
> so just move the API from generic_block_bmap to iomap_bmap for iomap
> conversion.
> 
> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
> Reviewed-by: Jan Kara <jack@suse.cz>
> ---
>  fs/ext4/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 6cf3b969dc86..81fccbae0aea 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3214,7 +3214,7 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
>  			return 0;
>  	}
>  
> -	return generic_block_bmap(mapping, block, ext4_get_block);
> +	return iomap_bmap(mapping, block, &ext4_iomap_ops);

/me notes that iomap_bmap will filemap_write_and_wait for you, so one
could optimize ext4_bmap to avoid the double-flush by moving the
filemap_write_and_wait at the top of the function into the JDATA state
clearing block.

OTOH it's bmap, who cares... :)

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

>  }
>  
>  static int ext4_readpage(struct file *file, struct page *page)
> -- 
> 2.21.0
>