Re: [PATCH 1/5] btrfs: pass unaligned length to btrfs_cmp_data()

[Liu Bo <bo.li.liu@oracle.com>]

On Tue, Jun 23, 2015 at 02:28:36PM -0700, Mark Fasheh wrote:
> In the case that we dedupe the tail of a file, we might expand the dedupe
> len out to the end of our last block. We don't want to compare data past
> i_size however, so pass the original length to btrfs_cmp_data().

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>

> 
> Signed-off-by: Mark Fasheh <mfasheh@suse.de>
> Reviewed-by: David Sterba <dsterba@suse.cz>
> ---
>  fs/btrfs/ioctl.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 2d24ff4..2deea1f 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -2933,7 +2933,8 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>  		goto out_unlock;
>  	}
>  
> -	ret = btrfs_cmp_data(src, loff, dst, dst_loff, len);
> +	/* pass original length for comparison so we stay within i_size */
> +	ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen);
>  	if (ret == 0)
>  		ret = btrfs_clone(src, dst, loff, olen, len, dst_loff);
>  
> -- 
> 2.1.2
> 
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