diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 699975c..7618960 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 #include "internal.h"
+#include "decompress.h"
 
 static int erofs_map_blocks_flatmode(struct erofs_inode *inode,
 				     struct erofs_map_blocks *map,
@@ -205,6 +206,93 @@
 	return 0;
 }
 
+static int z_erofs_read_data(struct erofs_inode *inode, char *buffer,
+			     erofs_off_t size, erofs_off_t offset)
+{
+	erofs_off_t end, length, skip;
+	struct erofs_map_blocks map = {
+		.index = UINT_MAX,
+	};
+	struct erofs_map_dev mdev;
+	bool partial;
+	unsigned int bufsize = 0;
+	char *raw = NULL;
+	int ret = 0;
+
+	end = offset + size;
+	while (end > offset) {
+		map.m_la = end - 1;
+
+		ret = z_erofs_map_blocks_iter(inode, &map, 0);
+		if (ret)
+			break;
+
+		/* no device id here, thus it will always succeed */
+		mdev = (struct erofs_map_dev) {
+			.m_pa = map.m_pa,
+		};
+		ret = erofs_map_dev(&sbi, &mdev);
+		if (ret) {
+			DBG_BUGON(1);
+			break;
+		}
+
+		/*
+		 * trim to the needed size if the returned extent is quite
+		 * larger than requested, and set up partial flag as well.
+		 */
+		if (end < map.m_la + map.m_llen) {
+			length = end - map.m_la;
+			partial = true;
+		} else {
+			DBG_BUGON(end != map.m_la + map.m_llen);
+			length = map.m_llen;
+			partial = !(map.m_flags & EROFS_MAP_FULL_MAPPED);
+		}
+
+		if (map.m_la < offset) {
+			skip = offset - map.m_la;
+			end = offset;
+		} else {
+			skip = 0;
+			end = map.m_la;
+		}
+
+		if (!(map.m_flags & EROFS_MAP_MAPPED)) {
+			memset(buffer + end - offset, 0, length);
+			end = map.m_la;
+			continue;
+		}
+
+		if (map.m_plen > bufsize) {
+			bufsize = map.m_plen;
+			raw = realloc(raw, bufsize);
+			if (!raw) {
+				ret = -ENOMEM;
+				break;
+			}
+		}
+		ret = erofs_dev_read(mdev.m_deviceid, raw, mdev.m_pa, map.m_plen);
+		if (ret < 0)
+			break;
+
+		ret = z_erofs_decompress(&(struct z_erofs_decompress_req) {
+					.in = raw,
+					.out = buffer + end - offset,
+					.decodedskip = skip,
+					.inputsize = map.m_plen,
+					.decodedlength = length,
+					.alg = map.m_algorithmformat,
+					.partial_decoding = partial
+					 });
+		if (ret < 0)
+			break;
+	}
+	if (raw)
+		free(raw);
+	return ret < 0 ? ret : 0;
+}
+
 int erofs_pread(struct erofs_inode *inode, char *buf,
 		erofs_off_t count, erofs_off_t offset)
 {
@@ -215,7 +303,7 @@
 		return erofs_read_raw_data(inode, buf, count, offset);
 	case EROFS_INODE_FLAT_COMPRESSION_LEGACY:
 	case EROFS_INODE_FLAT_COMPRESSION:
-		return -EOPNOTSUPP;
+		return z_erofs_read_data(inode, buf, count, offset);
 	default:
 		break;
 	}