xfs: swap inode reflink flags when swapping inode extents

When we're swapping the extents of two inodes, be sure to swap the
reflink inode flag too.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/xfs_bmap_util.c

@@ -1660,6 +1660,8 @@ xfs_swap_extents(
 	int		taforkblks = 0;
 	__uint64_t	tmp;
 	int		lock_flags;
+	struct xfs_ifork	*cowfp;
+	__uint64_t	f;
 
 	/* XXX: we can't do this with rmap, will fix later */
 	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
@@ -1873,6 +1875,19 @@ xfs_swap_extents(
 		break;
 	}
 
+	/* Do we have to swap reflink flags? */
+	if ((ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK) ^
+	    (tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)) {
+		f = ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
+		ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
+		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;
+		cowfp = ip->i_cowfp;
+		ip->i_cowfp = tip->i_cowfp;
+		tip->i_cowfp = cowfp;
+	}
+
 	xfs_trans_log_inode(tp, ip,  src_log_flags);
 	xfs_trans_log_inode(tp, tip, target_log_flags);