diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 3c54e95964c9..27caf4bebddc 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -299,6 +299,7 @@ static const char *z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 		return ERR_PTR(-EOPNOTSUPP);
 	if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
 		cur = bs - (rq->pageofs_out & (bs - 1));
+		DBG_BUGON(rq->pageofs_in & (bs - 1));
 		pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK;
 		cur = min(cur, rq->outputsize);
 		if (cur && rq->out[0]) {
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 5811556a7b71..b5411b579fd9 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -483,7 +483,8 @@ static int z_erofs_map_blocks_fo(struct inode *inode,
 	}
 
 	if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) {
-		if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
+		if ((vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER) &&
+		    !(map->m_flags & EROFS_MAP_META))
 			map->m_algorithmformat = Z_EROFS_COMPRESSION_INTERLACED;
 		else
 			map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;