diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 767fb4acdc93..7b150ac64742 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -15,6 +15,7 @@
 #define EROFS_FEATURE_COMPAT_SB_CHKSUM          0x00000001
 #define EROFS_FEATURE_COMPAT_MTIME              0x00000002
 #define EROFS_FEATURE_COMPAT_XATTR_FILTER	0x00000004
+#define EROFS_FEATURE_COMPAT_SHARED_EA_IN_METABOX	0x00000008
 
 /*
  * Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
@@ -31,6 +32,7 @@
 #define EROFS_FEATURE_INCOMPAT_DEDUPE		0x00000020
 #define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES	0x00000040
 #define EROFS_FEATURE_INCOMPAT_48BIT		0x00000080
+#define EROFS_FEATURE_INCOMPAT_METABOX		0x00000100
 #define EROFS_ALL_FEATURE_INCOMPAT		\
 	((EROFS_FEATURE_INCOMPAT_48BIT << 1) - 1)
 
@@ -46,7 +48,7 @@ struct erofs_deviceslot {
 };
 #define EROFS_DEVT_SLOT_SIZE	sizeof(struct erofs_deviceslot)
 
-/* erofs on-disk super block (currently 128 bytes) */
+/* erofs on-disk super block (currently 144 bytes at maximum) */
 struct erofs_super_block {
 	__le32 magic;           /* file system magic number */
 	__le32 checksum;        /* crc32c to avoid unexpected on-disk overlap */
@@ -82,7 +84,9 @@ struct erofs_super_block {
 	__u8 reserved[3];
 	__le32 build_time;	/* seconds added to epoch for mkfs time */
 	__le64 rootnid_8b;	/* (48BIT on) nid of root directory */
-	__u8 reserved2[8];
+	__le64 reserved2;
+	__le64 metabox_nid;     /* (METABOX on) nid of the metabox inode */
+	__le64 reserved3;	/* [align to extslot 1] */
 };
 
 /*
@@ -267,6 +271,9 @@ struct erofs_inode_chunk_index {
 	__le32 startblk_lo;	/* starting block number of this chunk */
 };
 
+#define EROFS_DIRENT_NID_METABOX_BIT	63
+#define EROFS_DIRENT_NID_MASK	(BIT_ULL(EROFS_DIRENT_NID_METABOX_BIT) - 1)
+
 /* dirent sorts in alphabet order, thus we can do binary search */
 struct erofs_dirent {
 	__le64 nid;     /* node number */
@@ -434,7 +441,7 @@ static inline void erofs_check_ondisk_layout_definitions(void)
 		.h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
 	};
 
-	BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
+	BUILD_BUG_ON(sizeof(struct erofs_super_block) != 144);
 	BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
 	BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64);
 	BUILD_BUG_ON(sizeof(struct erofs_xattr_ibody_header) != 12);
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index a7699114f6fe..ad932f670bb6 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -227,8 +227,10 @@ EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS)
 EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE)
 EROFS_FEATURE_FUNCS(xattr_prefixes, incompat, INCOMPAT_XATTR_PREFIXES)
 EROFS_FEATURE_FUNCS(48bit, incompat, INCOMPAT_48BIT)
+EROFS_FEATURE_FUNCS(metabox, incompat, INCOMPAT_METABOX)
 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
 EROFS_FEATURE_FUNCS(xattr_filter, compat, COMPAT_XATTR_FILTER)
+EROFS_FEATURE_FUNCS(shared_ea_in_metabox, compat, COMPAT_SHARED_EA_IN_METABOX)
 
 /* atomic flag definitions */
 #define EROFS_I_EA_INITED_BIT	0