xfs: disable reflink for zoned file systems

While the zoned on-disk format supports reflinks, the GC code currently
always unshares reflinks when moving blocks to new zones, thus making the
feature unusuable.  Disable reflinks until the GC code is refcount aware.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

Author: Christoph Hellwig

fs/xfs/xfs_super.c

@@ -1829,6 +1829,13 @@ xfs_fs_fill_super(
 			goto out_filestream_unmount;
 		}
 
+		if (xfs_has_zoned(mp)) {
+			xfs_alert(mp,
+	"reflink not compatible with zoned RT device!");
+			error = -EINVAL;
+			goto out_filestream_unmount;
+		}
+
 		if (xfs_globals.always_cow) {
 			xfs_info(mp, "using DEBUG-only always_cow mode.");
 			mp->m_always_cow = true;