Re: [PATCH] xfs: always swap the cow forks when swapping extents

[Brian Foster <bfoster@redhat.com>]

On Sat, Sep 23, 2017 at 12:12:08AM -0700, Darrick J. Wong wrote:
> Since the CoW fork exists as a secondary data structure to the data
> fork, we must always swap cow forks during swapext.  We also need to
> swap the extent counts and reset the cowblocks tags.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/xfs_bmap_util.c |   24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index bc6c6e1..e9db7fc 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -2122,11 +2122,31 @@ xfs_swap_extents(
>  		ip->i_d.di_flags2 |= tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
>  		tip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
>  		tip->i_d.di_flags2 |= f & XFS_DIFLAG2_REFLINK;
> +	}
> +
> +	/* Swap the cow forks. */
> +	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
> +		xfs_extnum_t	extnum;
> +
> +		ASSERT(ip->i_cformat == XFS_DINODE_FMT_EXTENTS);
> +		ASSERT(tip->i_cformat == XFS_DINODE_FMT_EXTENTS);
> +
> +		extnum = ip->i_cnextents;
> +		ip->i_cnextents = tip->i_cnextents;
> +		tip->i_cnextents = extnum;
> +
>  		cowfp = ip->i_cowfp;
>  		ip->i_cowfp = tip->i_cowfp;
>  		tip->i_cowfp = cowfp;
> -		xfs_inode_set_cowblocks_tag(ip);
> -		xfs_inode_set_cowblocks_tag(tip);
> +
> +		if (ip->i_cowfp && ip->i_cnextents)
> +			xfs_inode_set_cowblocks_tag(ip);
> +		else
> +			xfs_inode_clear_cowblocks_tag(ip);
> +		if (tip->i_cowfp && tip->i_cnextents)
> +			xfs_inode_set_cowblocks_tag(tip);
> +		else
> +			xfs_inode_clear_cowblocks_tag(tip);
>  	}
>  
>  	xfs_trans_log_inode(tp, ip,  src_log_flags);
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html