diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index d589ecef4ec7..7909e46b5c5a 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1520,12 +1520,12 @@ xfs_ioctl_setattr(
 	 * are set on the inode then unconditionally clear the extent size hint.
 	 */
 	if (ip->i_d.di_flags & (XFS_DIFLAG_EXTSIZE | XFS_DIFLAG_EXTSZINHERIT))
-		ip->i_extsize = fa->fsx_extsize >> mp->m_sb.sb_blocklog;
+		ip->i_extsize = XFS_B_TO_FSB(mp, fa->fsx_extsize);
 	else
 		ip->i_extsize = 0;
 	if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
 	    (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE))
-		ip->i_cowextsize = fa->fsx_cowextsize >> mp->m_sb.sb_blocklog;
+		ip->i_cowextsize = XFS_B_TO_FSB(mp, fa->fsx_cowextsize);
 	else
 		ip->i_cowextsize = 0;