fs/erofs: Introduce new features including ztailpacking, fragments and dedupe

This patch updates erofs driver code to catch up with the latest code of
erofs_utils (commit e4939f9eaa177e05d697ace85d8dc283e25dc2ed).

LZMA will be supported in the separate patch later.

Signed-off-by: Yifan Zhao <zhaoyifan@sjtu.edu.cn>
Reviewed-by: Huang Jianan <jnhuang95@gmail.com>

9 files changed, 642 insertions, 344 deletions

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 7618960..f4b21d7 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -12,23 +12,23 @@ static int erofs_map_blocks_flatmode(struct erofs_inode *inode,
 	struct erofs_inode *vi = inode;
 	bool tailendpacking = (vi->datalayout == EROFS_INODE_FLAT_INLINE);
 
-	nblocks = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+	nblocks = BLK_ROUND_UP(inode->i_size);
 	lastblk = nblocks - tailendpacking;
 
 	/* there is no hole in flatmode */
 	map->m_flags = EROFS_MAP_MAPPED;
 
-	if (offset < blknr_to_addr(lastblk)) {
-		map->m_pa = blknr_to_addr(vi->u.i_blkaddr) + map->m_la;
-		map->m_plen = blknr_to_addr(lastblk) - offset;
+	if (offset < erofs_pos(lastblk)) {
+		map->m_pa = erofs_pos(vi->u.i_blkaddr) + map->m_la;
+		map->m_plen = erofs_pos(lastblk) - offset;
 	} else if (tailendpacking) {
 		/* 2 - inode inline B: inode, [xattrs], inline last blk... */
 		map->m_pa = iloc(vi->nid) + vi->inode_isize +
 			vi->xattr_isize + erofs_blkoff(map->m_la);
 		map->m_plen = inode->i_size - offset;
 
-		/* inline data should be located in one meta block */
-		if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
+		/* inline data should be located in the same meta block */
+		if (erofs_blkoff(map->m_pa) + map->m_plen > erofs_blksiz()) {
 			erofs_err("inline data cross block boundary @ nid %" PRIu64,
 				  vi->nid);
 			DBG_BUGON(1);
@@ -55,7 +55,7 @@ int erofs_map_blocks(struct erofs_inode *inode,
 {
 	struct erofs_inode *vi = inode;
 	struct erofs_inode_chunk_index *idx;
-	u8 buf[EROFS_BLKSIZ];
+	u8 buf[EROFS_MAX_BLOCK_SIZE];
 	u64 chunknr;
 	unsigned int unit;
 	erofs_off_t pos;
@@ -87,7 +87,7 @@ int erofs_map_blocks(struct erofs_inode *inode,
 
 	map->m_la = chunknr << vi->u.chunkbits;
 	map->m_plen = min_t(erofs_off_t, 1UL << vi->u.chunkbits,
-			    roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));
+			    roundup(inode->i_size - map->m_la, erofs_blksiz()));
 
 	/* handle block map */
 	if (!(vi->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
@@ -96,7 +96,7 @@ int erofs_map_blocks(struct erofs_inode *inode,
 		if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
 			map->m_flags = 0;
 		} else {
-			map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr));
+			map->m_pa = erofs_pos(le32_to_cpu(*blkaddr));
 			map->m_flags = EROFS_MAP_MAPPED;
 		}
 		goto out;
@@ -110,7 +110,7 @@ int erofs_map_blocks(struct erofs_inode *inode,
 	default:
 		map->m_deviceid = le16_to_cpu(idx->device_id) &
 			sbi.device_id_mask;
-		map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr));
+		map->m_pa = erofs_pos(le32_to_cpu(idx->blkaddr));
 		map->m_flags = EROFS_MAP_MAPPED;
 		break;
 	}
@@ -119,23 +119,23 @@ out:
 	return err;
 }
 
-int erofs_map_dev(struct erofs_sb_info *sbi, struct erofs_map_dev *map)
+int erofs_map_dev(struct erofs_map_dev *map)
 {
 	struct erofs_device_info *dif;
 	int id;
 
 	if (map->m_deviceid) {
-		if (sbi->extra_devices < map->m_deviceid)
+		if (sbi.extra_devices < map->m_deviceid)
 			return -ENODEV;
-	} else if (sbi->extra_devices) {
-		for (id = 0; id < sbi->extra_devices; ++id) {
+	} else if (sbi.extra_devices) {
+		for (id = 0; id < sbi.extra_devices; ++id) {
 			erofs_off_t startoff, length;
 
-			dif = sbi->devs + id;
+			dif = sbi.devs + id;
 			if (!dif->mapped_blkaddr)
 				continue;
-			startoff = blknr_to_addr(dif->mapped_blkaddr);
-			length = blknr_to_addr(dif->blocks);
+			startoff = erofs_pos(dif->mapped_blkaddr);
+			length = erofs_pos(dif->blocks);
 
 			if (map->m_pa >= startoff &&
 			    map->m_pa < startoff + length) {
@@ -147,19 +147,38 @@ int erofs_map_dev(struct erofs_sb_info *sbi, struct erofs_map_dev *map)
 	return 0;
 }
 
+int erofs_read_one_data(struct erofs_map_blocks *map, char *buffer, u64 offset,
+			size_t len)
+{
+	struct erofs_map_dev mdev;
+	int ret;
+
+	mdev = (struct erofs_map_dev) {
+		.m_deviceid = map->m_deviceid,
+		.m_pa = map->m_pa,
+	};
+	ret = erofs_map_dev(&mdev);
+	if (ret)
+		return ret;
+
+	ret = erofs_dev_read(mdev.m_deviceid, buffer, mdev.m_pa + offset, len);
+	if (ret < 0)
+		return -EIO;
+	return 0;
+}
+
 static int erofs_read_raw_data(struct erofs_inode *inode, char *buffer,
 			       erofs_off_t size, erofs_off_t offset)
 {
 	struct erofs_map_blocks map = {
 		.index = UINT_MAX,
 	};
-	struct erofs_map_dev mdev;
 	int ret;
 	erofs_off_t ptr = offset;
 
 	while (ptr < offset + size) {
 		char *const estart = buffer + ptr - offset;
-		erofs_off_t eend;
+		erofs_off_t eend, moff = 0;
 
 		map.m_la = ptr;
 		ret = erofs_map_blocks(inode, &map, 0);
@@ -168,14 +187,6 @@ static int erofs_read_raw_data(struct erofs_inode *inode, char *buffer,
 
 		DBG_BUGON(map.m_plen != map.m_llen);
 
-		mdev = (struct erofs_map_dev) {
-			.m_deviceid = map.m_deviceid,
-			.m_pa = map.m_pa,
-		};
-		ret = erofs_map_dev(&sbi, &mdev);
-		if (ret)
-			return ret;
-
 		/* trim extent */
 		eend = min(offset + size, map.m_la + map.m_llen);
 		DBG_BUGON(ptr < map.m_la);
@@ -193,19 +204,73 @@ static int erofs_read_raw_data(struct erofs_inode *inode, char *buffer,
 		}
 
 		if (ptr > map.m_la) {
-			mdev.m_pa += ptr - map.m_la;
+			moff = ptr - map.m_la;
 			map.m_la = ptr;
 		}
 
-		ret = erofs_dev_read(mdev.m_deviceid, estart, mdev.m_pa,
-				     eend - map.m_la);
-		if (ret < 0)
-			return -EIO;
+		ret = erofs_read_one_data(&map, estart, moff, eend - map.m_la);
+		if (ret)
+			return ret;
 		ptr = eend;
 	}
 	return 0;
 }
 
+int z_erofs_read_one_data(struct erofs_inode *inode,
+			  struct erofs_map_blocks *map, char *raw, char *buffer,
+			  erofs_off_t skip, erofs_off_t length, bool trimmed)
+{
+	struct erofs_map_dev mdev;
+	int ret = 0;
+
+	if (map->m_flags & EROFS_MAP_FRAGMENT) {
+		struct erofs_inode packed_inode = {
+			.nid = sbi.packed_nid,
+		};
+
+		ret = erofs_read_inode_from_disk(&packed_inode);
+		if (ret) {
+			erofs_err("failed to read packed inode from disk");
+			return ret;
+		}
+
+		return erofs_pread(&packed_inode, buffer, length - skip,
+				   inode->fragmentoff + skip);
+	}
+
+	/* no device id here, thus it will always succeed */
+	mdev = (struct erofs_map_dev) {
+		.m_pa = map->m_pa,
+	};
+	ret = erofs_map_dev(&mdev);
+	if (ret) {
+		DBG_BUGON(1);
+		return ret;
+	}
+
+	ret = erofs_dev_read(mdev.m_deviceid, raw, mdev.m_pa, map->m_plen);
+	if (ret < 0)
+		return ret;
+
+	ret = z_erofs_decompress(&(struct z_erofs_decompress_req) {
+			.in = raw,
+			.out = buffer,
+			.decodedskip = skip,
+			.interlaced_offset =
+				map->m_algorithmformat == Z_EROFS_COMPRESSION_INTERLACED ?
+					erofs_blkoff(map->m_la) : 0,
+			.inputsize = map->m_plen,
+			.decodedlength = length,
+			.alg = map->m_algorithmformat,
+			.partial_decoding = trimmed ? true :
+				!(map->m_flags & EROFS_MAP_FULL_MAPPED) ||
+					(map->m_flags & EROFS_MAP_PARTIAL_REF),
+			 });
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
 static int z_erofs_read_data(struct erofs_inode *inode, char *buffer,
 			     erofs_off_t size, erofs_off_t offset)
 {
@@ -213,8 +278,7 @@ static int z_erofs_read_data(struct erofs_inode *inode, char *buffer,
 	struct erofs_map_blocks map = {
 		.index = UINT_MAX,
 	};
-	struct erofs_map_dev mdev;
-	bool partial;
+	bool trimmed;
 	unsigned int bufsize = 0;
 	char *raw = NULL;
 	int ret = 0;
@@ -227,27 +291,17 @@ static int z_erofs_read_data(struct erofs_inode *inode, char *buffer,
 		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;
+			trimmed = true;
 		} else {
 			DBG_BUGON(end != map.m_la + map.m_llen);
 			length = map.m_llen;
-			partial = !(map.m_flags & EROFS_MAP_FULL_MAPPED);
+			trimmed = false;
 		}
 
 		if (map.m_la < offset) {
@@ -272,19 +326,10 @@ static int z_erofs_read_data(struct erofs_inode *inode, char *buffer,
 				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
-					 });
+		ret = z_erofs_read_one_data(inode, &map, raw,
+					    buffer + end - offset, skip, length,
+					    trimmed);
 		if (ret < 0)
 			break;
 	}
@@ -301,8 +346,8 @@ int erofs_pread(struct erofs_inode *inode, char *buf,
 	case EROFS_INODE_FLAT_INLINE:
 	case EROFS_INODE_CHUNK_BASED:
 		return erofs_read_raw_data(inode, buf, count, offset);
-	case EROFS_INODE_FLAT_COMPRESSION_LEGACY:
-	case EROFS_INODE_FLAT_COMPRESSION:
+	case EROFS_INODE_COMPRESSED_FULL:
+	case EROFS_INODE_COMPRESSED_COMPACT:
 		return z_erofs_read_data(inode, buf, count, offset);
 	default:
 		break;
diff --git a/fs/erofs/decompress.c b/fs/erofs/decompress.c
index 2be3b84..e04e5c3 100644
--- a/fs/erofs/decompress.c
+++ b/fs/erofs/decompress.c
@@ -15,8 +15,8 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
 	if (erofs_sb_has_lz4_0padding()) {
 		support_0padding = true;
 
-		while (!src[inputmargin & ~PAGE_MASK])
-			if (!(++inputmargin & ~PAGE_MASK))
+		while (!src[inputmargin & (erofs_blksiz() - 1)])
+			if (!(++inputmargin & (erofs_blksiz() - 1)))
 				break;
 
 		if (inputmargin >= rq->inputsize)
@@ -40,6 +40,9 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
 					  rq->decodedlength);
 
 	if (ret != (int)rq->decodedlength) {
+		erofs_err("failed to %s decompress %d in[%u, %u] out[%u]",
+			  rq->partial_decoding ? "partial" : "full",
+			  ret, rq->inputsize, inputmargin, rq->decodedlength);
 		ret = -EIO;
 		goto out;
 	}
@@ -58,13 +61,30 @@ out:
 
 int z_erofs_decompress(struct z_erofs_decompress_req *rq)
 {
-	if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
-		if (rq->inputsize != EROFS_BLKSIZ)
+	if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
+		unsigned int count, rightpart, skip;
+
+		/* XXX: should support inputsize >= erofs_blksiz() later */
+		if (rq->inputsize > erofs_blksiz())
 			return -EFSCORRUPTED;
 
-		DBG_BUGON(rq->decodedlength > EROFS_BLKSIZ);
-		DBG_BUGON(rq->decodedlength < rq->decodedskip);
+		if (rq->decodedlength > erofs_blksiz())
+			return -EFSCORRUPTED;
+
+		if (rq->decodedlength < rq->decodedskip)
+			return -EFSCORRUPTED;
 
+		count = rq->decodedlength - rq->decodedskip;
+		skip = erofs_blkoff(rq->interlaced_offset + rq->decodedskip);
+		rightpart = min(erofs_blksiz() - skip, count);
+		memcpy(rq->out, rq->in + skip, rightpart);
+		memcpy(rq->out + rightpart, rq->in, count - rightpart);
+		return 0;
+	} else if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
+		if (rq->decodedlength > rq->inputsize)
+			return -EFSCORRUPTED;
+
+		DBG_BUGON(rq->decodedlength < rq->decodedskip);
 		memcpy(rq->out, rq->in + rq->decodedskip,
 		       rq->decodedlength - rq->decodedskip);
 		return 0;
diff --git a/fs/erofs/decompress.h b/fs/erofs/decompress.h
index 81d5fb8..4752f77 100644
--- a/fs/erofs/decompress.h
+++ b/fs/erofs/decompress.h
@@ -14,6 +14,9 @@ struct z_erofs_decompress_req {
 	unsigned int decodedskip;
 	unsigned int inputsize, decodedlength;
 
+	/* cut point of interlaced uncompressed data */
+	unsigned int interlaced_offset;
+
 	/* indicate the algorithm will be used for decompression */
 	unsigned int alg;
 	bool partial_decoding;
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 6b62c7a..158e2c6 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -3,7 +3,7 @@
  * EROFS (Enhanced ROM File System) on-disk format definition
  *
  * Copyright (C) 2017-2018 HUAWEI, Inc.
- *             http://www.huawei.com/
+ *             https://www.huawei.com/
  * Copyright (C) 2021, Alibaba Cloud
  */
 #ifndef __EROFS_FS_H
@@ -18,33 +18,41 @@
 #define EROFS_SUPER_MAGIC_V1    0xE0F5E1E2
 #define EROFS_SUPER_OFFSET      1024
 
-#define EROFS_FEATURE_COMPAT_SB_CHKSUM		0x00000001
+#define EROFS_FEATURE_COMPAT_SB_CHKSUM          0x00000001
+#define EROFS_FEATURE_COMPAT_MTIME              0x00000002
 
 /*
  * Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
  * be incompatible with this kernel version.
  */
-#define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING	0x00000001
+#define EROFS_FEATURE_INCOMPAT_ZERO_PADDING	0x00000001
 #define EROFS_FEATURE_INCOMPAT_COMPR_CFGS	0x00000002
 #define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER	0x00000002
 #define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE	0x00000004
 #define EROFS_FEATURE_INCOMPAT_DEVICE_TABLE	0x00000008
+#define EROFS_FEATURE_INCOMPAT_COMPR_HEAD2	0x00000008
+#define EROFS_FEATURE_INCOMPAT_ZTAILPACKING	0x00000010
+#define EROFS_FEATURE_INCOMPAT_FRAGMENTS	0x00000020
+#define EROFS_FEATURE_INCOMPAT_DEDUPE		0x00000020
+#define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES	0x00000040
 #define EROFS_ALL_FEATURE_INCOMPAT		\
-	(EROFS_FEATURE_INCOMPAT_LZ4_0PADDING | \
+	(EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
 	 EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
 	 EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER | \
 	 EROFS_FEATURE_INCOMPAT_CHUNKED_FILE | \
-	 EROFS_FEATURE_INCOMPAT_DEVICE_TABLE)
+	 EROFS_FEATURE_INCOMPAT_DEVICE_TABLE | \
+	 EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 | \
+	 EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
+	 EROFS_FEATURE_INCOMPAT_FRAGMENTS | \
+	 EROFS_FEATURE_INCOMPAT_DEDUPE | \
+	 EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES)
 
 #define EROFS_SB_EXTSLOT_SIZE	16
 
 struct erofs_deviceslot {
-	union {
-		u8 uuid[16];		/* used for device manager later */
-		u8 userdata[64];	/* digest(sha256), etc. */
-	} u;
-	__le32 blocks;			/* total fs blocks of this device */
-	__le32 mapped_blkaddr;		/* map starting at mapped_blkaddr */
+	u8 tag[64];		/* digest(sha256), etc. */
+	__le32 blocks;		/* total fs blocks of this device */
+	__le32 mapped_blkaddr;	/* map starting at mapped_blkaddr */
 	u8 reserved[56];
 };
 
@@ -55,14 +63,14 @@ struct erofs_super_block {
 	__le32 magic;           /* file system magic number */
 	__le32 checksum;        /* crc32c(super_block) */
 	__le32 feature_compat;
-	__u8 blkszbits;         /* support block_size == PAGE_SIZE only */
+	__u8 blkszbits;         /* filesystem block size in bit shift */
 	__u8 sb_extslots;	/* superblock size = 128 + sb_extslots * 16 */
 
 	__le16 root_nid;	/* nid of root directory */
 	__le64 inos;            /* total valid ino # (== f_files - f_favail) */
 
-	__le64 build_time;      /* inode v1 time derivation */
-	__le32 build_time_nsec;	/* inode v1 time derivation in nano scale */
+	__le64 build_time;      /* compact inode time derivation */
+	__le32 build_time_nsec;	/* compact inode time derivation in ns scale */
 	__le32 blocks;          /* used for statfs */
 	__le32 meta_blkaddr;	/* start block address of metadata area */
 	__le32 xattr_blkaddr;	/* start block address of shared xattr area */
@@ -77,39 +85,38 @@ struct erofs_super_block {
 	} __packed u1;
 	__le16 extra_devices;	/* # of devices besides the primary device */
 	__le16 devt_slotoff;	/* startoff = devt_slotoff * devt_slotsize */
-	__u8 reserved2[38];
+	__u8 dirblkbits;	/* directory block size in bit shift */
+	__u8 xattr_prefix_count;	/* # of long xattr name prefixes */
+	__le32 xattr_prefix_start;	/* start of long xattr prefixes */
+	__le64 packed_nid;	/* nid of the special packed inode */
+	__u8 reserved2[24];
 };
 
 /*
- * erofs inode datalayout (i_format in on-disk inode):
- * 0 - inode plain without inline data A:
- * inode, [xattrs], ... | ... | no-holed data
- * 1 - inode VLE compression B (legacy):
- * inode, [xattrs], extents ... | ...
- * 2 - inode plain with inline data C:
- * inode, [xattrs], last_inline_data, ... | ... | no-holed data
- * 3 - inode compression D:
- * inode, [xattrs], map_header, extents ... | ...
- * 4 - inode chunk-based E:
- * inode, [xattrs], chunk indexes ... | ...
+ * EROFS inode datalayout (i_format in on-disk inode):
+ * 0 - uncompressed flat inode without tail-packing inline data:
+ * 1 - compressed inode with non-compact indexes:
+ * 2 - uncompressed flat inode with tail-packing inline data:
+ * 3 - compressed inode with compact indexes:
+ * 4 - chunk-based inode with (optional) multi-device support:
  * 5~7 - reserved
  */
 enum {
 	EROFS_INODE_FLAT_PLAIN			= 0,
-	EROFS_INODE_FLAT_COMPRESSION_LEGACY	= 1,
+	EROFS_INODE_COMPRESSED_FULL		= 1,
 	EROFS_INODE_FLAT_INLINE			= 2,
-	EROFS_INODE_FLAT_COMPRESSION		= 3,
+	EROFS_INODE_COMPRESSED_COMPACT		= 3,
 	EROFS_INODE_CHUNK_BASED			= 4,
 	EROFS_INODE_DATALAYOUT_MAX
 };
 
 static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
 {
-	return datamode == EROFS_INODE_FLAT_COMPRESSION ||
-		datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY;
+	return datamode == EROFS_INODE_COMPRESSED_COMPACT ||
+		datamode == EROFS_INODE_COMPRESSED_FULL;
 }
 
-/* bit definitions of inode i_advise */
+/* bit definitions of inode i_format */
 #define EROFS_I_VERSION_BITS            1
 #define EROFS_I_DATALAYOUT_BITS         3
 
@@ -127,11 +134,30 @@ static inline bool erofs_inode_is_data_compressed(unsigned int datamode)
 #define EROFS_CHUNK_FORMAT_ALL	\
 	(EROFS_CHUNK_FORMAT_BLKBITS_MASK | EROFS_CHUNK_FORMAT_INDEXES)
 
+/* 32-byte on-disk inode */
+#define EROFS_INODE_LAYOUT_COMPACT	0
+/* 64-byte on-disk inode */
+#define EROFS_INODE_LAYOUT_EXTENDED	1
+
 struct erofs_inode_chunk_info {
 	__le16 format;		/* chunk blkbits, etc. */
 	__le16 reserved;
 };
 
+union erofs_inode_i_u {
+	/* total compressed blocks for compressed inodes */
+	__le32 compressed_blocks;
+
+	/* block address for uncompressed flat inodes */
+	__le32 raw_blkaddr;
+
+	/* for device files, used to indicate old/new device # */
+	__le32 rdev;
+
+	/* for chunk-based files, it contains the summary info */
+	struct erofs_inode_chunk_info c;
+};
+
 /* 32-byte reduced form of an ondisk inode */
 struct erofs_inode_compact {
 	__le16 i_format;	/* inode format hints */
@@ -142,28 +168,14 @@ struct erofs_inode_compact {
 	__le16 i_nlink;
 	__le32 i_size;
 	__le32 i_reserved;
-	union {
-		/* file total compressed blocks for data mapping 1 */
-		__le32 compressed_blocks;
-		__le32 raw_blkaddr;
+	union erofs_inode_i_u i_u;
 
-		/* for device files, used to indicate old/new device # */
-		__le32 rdev;
-
-		/* for chunk-based files, it contains the summary info */
-		struct erofs_inode_chunk_info c;
-	} i_u;
-	__le32 i_ino;           /* only used for 32-bit stat compatibility */
+	__le32 i_ino;		/* only used for 32-bit stat compatibility */
 	__le16 i_uid;
 	__le16 i_gid;
 	__le32 i_reserved2;
 };
 
-/* 32 bytes on-disk inode */
-#define EROFS_INODE_LAYOUT_COMPACT	0
-/* 64 bytes on-disk inode */
-#define EROFS_INODE_LAYOUT_EXTENDED	1
-
 /* 64-byte complete form of an ondisk inode */
 struct erofs_inode_extended {
 	__le16 i_format;	/* inode format hints */
@@ -173,33 +185,17 @@ struct erofs_inode_extended {
 	__le16 i_mode;
 	__le16 i_reserved;
 	__le64 i_size;
-	union {
-		/* file total compressed blocks for data mapping 1 */
-		__le32 compressed_blocks;
-		__le32 raw_blkaddr;
-
-		/* for device files, used to indicate old/new device # */
-		__le32 rdev;
-
-		/* for chunk-based files, it contains the summary info */
-		struct erofs_inode_chunk_info c;
-	} i_u;
-
-	/* only used for 32-bit stat compatibility */
-	__le32 i_ino;
+	union erofs_inode_i_u i_u;
 
+	__le32 i_ino;		/* only used for 32-bit stat compatibility */
 	__le32 i_uid;
 	__le32 i_gid;
-	__le64 i_ctime;
-	__le32 i_ctime_nsec;
+	__le64 i_mtime;
+	__le32 i_mtime_nsec;
 	__le32 i_nlink;
 	__u8   i_reserved2[16];
 };
 
-#define EROFS_MAX_SHARED_XATTRS         (128)
-/* h_shared_count between 129 ... 255 are special # */
-#define EROFS_SHARED_XATTR_EXTENT       (255)
-
 /*
  * inline xattrs (n == i_xattr_icount):
  * erofs_xattr_ibody_header(1) + (n - 1) * 4 bytes
@@ -226,6 +222,13 @@ struct erofs_xattr_ibody_header {
 #define EROFS_XATTR_INDEX_LUSTRE            5
 #define EROFS_XATTR_INDEX_SECURITY          6
 
+/*
+ * bit 7 of e_name_index is set when it refers to a long xattr name prefix,
+ * while the remained lower bits represent the index of the prefix.
+ */
+#define EROFS_XATTR_LONG_PREFIX		0x80
+#define EROFS_XATTR_LONG_PREFIX_MASK	0x7f
+
 /* xattr entry (for both inline & shared xattrs) */
 struct erofs_xattr_entry {
 	__u8   e_name_len;      /* length of name */
@@ -235,6 +238,12 @@ struct erofs_xattr_entry {
 	char   e_name[0];       /* attribute name */
 };
 
+/* long xattr name prefix */
+struct erofs_xattr_long_prefix {
+	__u8   base_index;	/* short xattr name prefix index */
+	char   infix[0];	/* infix apart from short prefix */
+};
+
 static inline unsigned int erofs_xattr_ibody_size(__le16 i_xattr_icount)
 {
 	if (!i_xattr_icount)
@@ -265,6 +274,29 @@ struct erofs_inode_chunk_index {
 	__le32 blkaddr;		/* start block address of this inode chunk */
 };
 
+/* dirent sorts in alphabet order, thus we can do binary search */
+struct erofs_dirent {
+	__le64 nid;     /* node number */
+	__le16 nameoff; /* start offset of file name */
+	__u8 file_type; /* file type */
+	__u8 reserved;  /* reserved */
+} __packed;
+
+/* file types used in inode_info->flags */
+enum {
+	EROFS_FT_UNKNOWN,
+	EROFS_FT_REG_FILE,
+	EROFS_FT_DIR,
+	EROFS_FT_CHRDEV,
+	EROFS_FT_BLKDEV,
+	EROFS_FT_FIFO,
+	EROFS_FT_SOCK,
+	EROFS_FT_SYMLINK,
+	EROFS_FT_MAX
+};
+
+#define EROFS_NAME_LEN      255
+
 /* maximum supported size of a physical compression cluster */
 #define Z_EROFS_PCLUSTER_MAX_SIZE	(1024 * 1024)
 
@@ -275,7 +307,7 @@ enum {
 	Z_EROFS_COMPRESSION_MAX
 };
 
-#define Z_EROFS_ALL_COMPR_ALGS		(1 << (Z_EROFS_COMPRESSION_MAX - 1))
+#define Z_EROFS_ALL_COMPR_ALGS		((1 << Z_EROFS_COMPRESSION_MAX) - 1)
 
 /* 14 bytes (+ length field = 16 bytes) */
 struct z_erofs_lz4_cfgs {
@@ -290,6 +322,7 @@ struct z_erofs_lzma_cfgs {
 	__le16 format;
 	u8 reserved[8];
 } __packed;
+
 #define Z_EROFS_LZMA_MAX_DICT_SIZE	(8 * Z_EROFS_PCLUSTER_MAX_SIZE)
 
 /*
@@ -298,13 +331,28 @@ struct z_erofs_lzma_cfgs {
  *                                  (4B) + 2B + (4B) if compacted 2B is on.
  * bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
  * bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
+ * bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
+ * bit 4 : interlaced plain pcluster (0 - off; 1 - on)
+ * bit 5 : fragment pcluster (0 - off; 1 - on)
  */
 #define Z_EROFS_ADVISE_COMPACTED_2B		0x0001
 #define Z_EROFS_ADVISE_BIG_PCLUSTER_1		0x0002
 #define Z_EROFS_ADVISE_BIG_PCLUSTER_2		0x0004
+#define Z_EROFS_ADVISE_INLINE_PCLUSTER		0x0008
+#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER	0x0010
+#define Z_EROFS_ADVISE_FRAGMENT_PCLUSTER	0x0020
 
+#define Z_EROFS_FRAGMENT_INODE_BIT              7
 struct z_erofs_map_header {
-	__le32	h_reserved1;
+	union {
+		/* fragment data offset in the packed inode */
+		__le32  h_fragmentoff;
+		struct {
+			__le16  h_reserved1;
+			/* indicates the encoded size of tailpacking data */
+			__le16  h_idata_size;
+		};
+	};
 	__le16	h_advise;
 	/*
 	 * bit 0-3 : algorithm type of head 1 (logical cluster type 01);
@@ -313,107 +361,85 @@ struct z_erofs_map_header {
 	__u8	h_algorithmtype;
 	/*
 	 * bit 0-2 : logical cluster bits - 12, e.g. 0 for 4096;
-	 * bit 3-7 : reserved.
+	 * bit 3-6 : reserved;
+	 * bit 7   : move the whole file into packed inode or not.
 	 */
 	__u8	h_clusterbits;
 };
 
-#define Z_EROFS_VLE_LEGACY_HEADER_PADDING       8
-
 /*
- * Fixed-sized output compression ondisk Logical Extent cluster type:
- *    0 - literal (uncompressed) cluster
- *    1 - compressed cluster (for the head logical cluster)
- *    2 - compressed cluster (for the other logical clusters)
+ * On-disk logical cluster type:
+ *    0   - literal (uncompressed) lcluster
+ *    1,3 - compressed lcluster (for HEAD lclusters)
+ *    2   - compressed lcluster (for NONHEAD lclusters)
  *
  * In detail,
- *    0 - literal (uncompressed) cluster,
+ *    0 - literal (uncompressed) lcluster,
  *        di_advise = 0
- *        di_clusterofs = the literal data offset of the cluster
- *        di_blkaddr = the blkaddr of the literal cluster
+ *        di_clusterofs = the literal data offset of the lcluster
+ *        di_blkaddr = the blkaddr of the literal pcluster
  *
- *    1 - compressed cluster (for the head logical cluster)
- *        di_advise = 1
- *        di_clusterofs = the decompressed data offset of the cluster
- *        di_blkaddr = the blkaddr of the compressed cluster
+ *    1,3 - compressed lcluster (for HEAD lclusters)
+ *        di_advise = 1 or 3
+ *        di_clusterofs = the decompressed data offset of the lcluster
+ *        di_blkaddr = the blkaddr of the compressed pcluster
  *
- *    2 - compressed cluster (for the other logical clusters)
+ *    2 - compressed lcluster (for NONHEAD lclusters)
  *        di_advise = 2
  *        di_clusterofs =
- *           the decompressed data offset in its own head cluster
- *        di_u.delta[0] = distance to its corresponding head cluster
- *        di_u.delta[1] = distance to its corresponding tail cluster
- *                (di_advise could be 0, 1 or 2)
+ *           the decompressed data offset in its own HEAD lcluster
+ *        di_u.delta[0] = distance to this HEAD lcluster
+ *        di_u.delta[1] = distance to the next HEAD lcluster
  */
 enum {
-	Z_EROFS_VLE_CLUSTER_TYPE_PLAIN		= 0,
-	Z_EROFS_VLE_CLUSTER_TYPE_HEAD		= 1,
-	Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD	= 2,
-	Z_EROFS_VLE_CLUSTER_TYPE_RESERVED	= 3,
-	Z_EROFS_VLE_CLUSTER_TYPE_MAX
+	Z_EROFS_LCLUSTER_TYPE_PLAIN	= 0,
+	Z_EROFS_LCLUSTER_TYPE_HEAD1	= 1,
+	Z_EROFS_LCLUSTER_TYPE_NONHEAD	= 2,
+	Z_EROFS_LCLUSTER_TYPE_HEAD2	= 3,
+	Z_EROFS_LCLUSTER_TYPE_MAX
 };
 
-#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS        2
-#define Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT         0
+#define Z_EROFS_LI_LCLUSTER_TYPE_BITS        2
+#define Z_EROFS_LI_LCLUSTER_TYPE_BIT         0
+
+/* (noncompact only, HEAD) This pcluster refers to partial decompressed data */
+#define Z_EROFS_LI_PARTIAL_REF		(1 << 15)
 
 /*
  * D0_CBLKCNT will be marked _only_ at the 1st non-head lcluster to store the
  * compressed block count of a compressed extent (in logical clusters, aka.
  * block count of a pcluster).
  */
-#define Z_EROFS_VLE_DI_D0_CBLKCNT		(1 << 11)
+#define Z_EROFS_LI_D0_CBLKCNT		(1 << 11)
 
-struct z_erofs_vle_decompressed_index {
+struct z_erofs_lcluster_index {
 	__le16 di_advise;
-	/* where to decompress in the head cluster */
+	/* where to decompress in the head lcluster */
 	__le16 di_clusterofs;
 
 	union {
-		/* for the head cluster */
+		/* for the HEAD lclusters */
 		__le32 blkaddr;
 		/*
-		 * for the rest clusters
-		 * eg. for 4k page-sized cluster, maximum 4K*64k = 256M)
-		 * [0] - pointing to the head cluster
-		 * [1] - pointing to the tail cluster
+		 * for the NONHEAD lclusters
+		 * [0] - distance to its HEAD lcluster
+		 * [1] - distance to the next HEAD lcluster
 		 */
 		__le16 delta[2];
 	} di_u;
 };
 
-#define Z_EROFS_VLE_LEGACY_INDEX_ALIGN(size) \
-	(round_up(size, sizeof(struct z_erofs_vle_decompressed_index)) + \
-	 sizeof(struct z_erofs_map_header) + Z_EROFS_VLE_LEGACY_HEADER_PADDING)
-
-#define Z_EROFS_VLE_EXTENT_ALIGN(size) round_up(size, \
-	sizeof(struct z_erofs_vle_decompressed_index))
-
-/* dirent sorts in alphabet order, thus we can do binary search */
-struct erofs_dirent {
-	__le64 nid;     /* node number */
-	__le16 nameoff; /* start offset of file name */
-	__u8 file_type; /* file type */
-	__u8 reserved;  /* reserved */
-} __packed;
-
-/* file types used in inode_info->flags */
-enum {
-	EROFS_FT_UNKNOWN,
-	EROFS_FT_REG_FILE,
-	EROFS_FT_DIR,
-	EROFS_FT_CHRDEV,
-	EROFS_FT_BLKDEV,
-	EROFS_FT_FIFO,
-	EROFS_FT_SOCK,
-	EROFS_FT_SYMLINK,
-	EROFS_FT_MAX
-};
-
-#define EROFS_NAME_LEN      255
+#define Z_EROFS_FULL_INDEX_ALIGN(end)	\
+	(round_up(end, 8) + sizeof(struct z_erofs_map_header) + 8)
 
 /* check the EROFS on-disk layout strictly at compile time */
 static inline void erofs_check_ondisk_layout_definitions(void)
 {
+	const __le64 fmh __maybe_unused =
+		*(__le64 *)&(struct z_erofs_map_header) {
+			.h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
+		};
+
 	BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
 	BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
 	BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64);
@@ -422,15 +448,18 @@ static inline void erofs_check_ondisk_layout_definitions(void)
 	BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_info) != 4);
 	BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) != 8);
 	BUILD_BUG_ON(sizeof(struct z_erofs_map_header) != 8);
-	BUILD_BUG_ON(sizeof(struct z_erofs_vle_decompressed_index) != 8);
+	BUILD_BUG_ON(sizeof(struct z_erofs_lcluster_index) != 8);
 	BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12);
 	/* keep in sync between 2 index structures for better extendibility */
 	BUILD_BUG_ON(sizeof(struct erofs_inode_chunk_index) !=
-		     sizeof(struct z_erofs_vle_decompressed_index));
+		     sizeof(struct z_erofs_lcluster_index));
 	BUILD_BUG_ON(sizeof(struct erofs_deviceslot) != 128);
 
-	BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
-		     Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
+	BUILD_BUG_ON(BIT(Z_EROFS_LI_LCLUSTER_TYPE_BITS) <
+		     Z_EROFS_LCLUSTER_TYPE_MAX - 1);
+	/* exclude old compiler versions like gcc 7.5.0 */
+	BUILD_BUG_ON(__builtin_constant_p(fmh) ?
+		     fmh != cpu_to_le64(1ULL << 63) : 0);
 }
 
 #endif
diff --git a/fs/erofs/fs.c b/fs/erofs/fs.c
index 8926975..7bd2e8f 100644
--- a/fs/erofs/fs.c
+++ b/fs/erofs/fs.c
@@ -25,8 +25,8 @@ int erofs_dev_read(int device_id, void *buf, u64 offset, size_t len)
 
 int erofs_blk_read(void *buf, erofs_blk_t start, u32 nblocks)
 {
-	return erofs_dev_read(0, buf, blknr_to_addr(start),
-			 blknr_to_addr(nblocks));
+	return erofs_dev_read(0, buf, erofs_pos(start),
+			 erofs_pos(nblocks));
 }
 
 int erofs_probe(struct blk_desc *fs_dev_desc,
@@ -52,7 +52,7 @@ struct erofs_dir_stream {
 	struct fs_dirent dirent;
 
 	struct erofs_inode inode;
-	char dblk[EROFS_BLKSIZ];
+	char dblk[EROFS_MAX_BLOCK_SIZE];
 	unsigned int maxsize, de_end;
 	erofs_off_t pos;
 };
@@ -125,7 +125,7 @@ int erofs_readdir(struct fs_dir_stream *fs_dirs, struct fs_dirent **dentp)
 		return 1;
 
 	if (!dirs->maxsize) {
-		dirs->maxsize = min_t(unsigned int, EROFS_BLKSIZ,
+		dirs->maxsize = min_t(unsigned int, EROFS_MAX_BLOCK_SIZE,
 				      dirs->inode.i_size - pos);
 
 		err = erofs_pread(&dirs->inode, dirs->dblk,
@@ -136,7 +136,7 @@ int erofs_readdir(struct fs_dir_stream *fs_dirs, struct fs_dirent **dentp)
 		de = (struct erofs_dirent *)dirs->dblk;
 		dirs->de_end = le16_to_cpu(de->nameoff);
 		if (dirs->de_end < sizeof(struct erofs_dirent) ||
-		    dirs->de_end >= EROFS_BLKSIZ) {
+		    dirs->de_end >= EROFS_MAX_BLOCK_SIZE) {
 			erofs_err("invalid de[0].nameoff %u @ nid %llu",
 				  dirs->de_end, de->nid | 0ULL);
 			return -EFSCORRUPTED;
@@ -183,7 +183,7 @@ int erofs_readdir(struct fs_dir_stream *fs_dirs, struct fs_dirent **dentp)
 
 	pos += sizeof(*de);
 	if (erofs_blkoff(pos) >= dirs->de_end) {
-		pos = blknr_to_addr(erofs_blknr(pos) + 1);
+		pos = erofs_pos(erofs_blknr(pos) + 1);
 		dirs->maxsize = 0;
 	}
 	dirs->pos = pos;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 4af7c91..433a3c6 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -2,6 +2,7 @@
 #ifndef __EROFS_INTERNAL_H
 #define __EROFS_INTERNAL_H
 
+#include "linux/compat.h"
 #define __packed __attribute__((__packed__))
 
 #include <linux/stat.h>
@@ -30,8 +31,9 @@
 
 #define PAGE_MASK		(~(PAGE_SIZE - 1))
 
-#define LOG_BLOCK_SIZE          (12)
-#define EROFS_BLKSIZ            (1U << LOG_BLOCK_SIZE)
+#ifndef EROFS_MAX_BLOCK_SIZE
+#define EROFS_MAX_BLOCK_SIZE	PAGE_SIZE
+#endif
 
 #define EROFS_ISLOTBITS		5
 #define EROFS_SLOTSIZE		(1U << EROFS_ISLOTBITS)
@@ -44,11 +46,15 @@ typedef u32 erofs_blk_t;
 #define NULL_ADDR	((unsigned int)-1)
 #define NULL_ADDR_UL	((unsigned long)-1)
 
-#define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
-#define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
-#define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
+/* global sbi */
+extern struct erofs_sb_info sbi;
+
+#define erofs_blksiz()		(1u << sbi.blkszbits)
+#define erofs_blknr(addr)       ((addr) >> sbi.blkszbits)
+#define erofs_blkoff(addr)      ((addr) & (erofs_blksiz() - 1))
+#define erofs_pos(nr)           ((erofs_off_t)(nr) << sbi.blkszbits)
 
-#define BLK_ROUND_UP(addr)	DIV_ROUND_UP(addr, EROFS_BLKSIZ)
+#define BLK_ROUND_UP(addr)	DIV_ROUND_UP(addr, 1u << sbi.blkszbits)
 
 struct erofs_buffer_head;
 
@@ -57,6 +63,8 @@ struct erofs_device_info {
 	u32 mapped_blkaddr;
 };
 
+#define EROFS_PACKED_NID_UNALLOCATED	-1
+
 struct erofs_sb_info {
 	struct erofs_device_info *devs;
 
@@ -72,6 +80,7 @@ struct erofs_sb_info {
 	u32 build_time_nsec;
 
 	unsigned char islotbits;
+	unsigned char blkszbits;
 
 	/* what we really care is nid, rather than ino.. */
 	erofs_nid_t root_nid;
@@ -79,23 +88,29 @@ struct erofs_sb_info {
 	u64 inos;
 
 	u8 uuid[16];
+	char volume_name[16];
 
 	u16 available_compr_algs;
 	u16 lz4_max_distance;
+
 	u32 checksum;
 	u16 extra_devices;
 	union {
 		u16 devt_slotoff;		/* used for mkfs */
 		u16 device_id_mask;		/* used for others */
 	};
+	erofs_nid_t packed_nid;
+
+	u32 xattr_prefix_start;
+	u8 xattr_prefix_count;
 };
 
-/* global sbi */
-extern struct erofs_sb_info sbi;
+/* make sure that any user of the erofs headers has at least 64bit off_t type */
+extern int erofs_assert_largefile[sizeof(off_t) - 8];
 
 static inline erofs_off_t iloc(erofs_nid_t nid)
 {
-	return blknr_to_addr(sbi.meta_blkaddr) + (nid << sbi.islotbits);
+	return erofs_pos(sbi.meta_blkaddr) + (nid << sbi.islotbits);
 }
 
 #define EROFS_FEATURE_FUNCS(name, compat, feature) \
@@ -112,11 +127,15 @@ static inline void erofs_sb_clear_##name(void) \
 	sbi.feature_##compat &= ~EROFS_FEATURE_##feature; \
 }
 
-EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
+EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_ZERO_PADDING)
 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
 EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
 EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
+EROFS_FEATURE_FUNCS(ztailpacking, incompat, INCOMPAT_ZTAILPACKING)
+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(sb_chksum, compat, COMPAT_SB_CHKSUM)
 
 #define EROFS_I_EA_INITED	(1 << 0)
@@ -130,6 +149,8 @@ struct erofs_inode {
 		unsigned int flags;
 		/* (mkfs.erofs) device ID containing source file */
 		u32 dev;
+		/* (mkfs.erofs) queued sub-directories blocking dump */
+		u32 subdirs_queued;
 	};
 	unsigned int i_count;
 	struct erofs_inode *i_parent;
@@ -140,8 +161,8 @@ struct erofs_inode {
 	u64 i_ino[2];
 	u32 i_uid;
 	u32 i_gid;
-	u64 i_ctime;
-	u32 i_ctime_nsec;
+	u64 i_mtime;
+	u32 i_mtime_nsec;
 	u32 i_nlink;
 
 	union {
@@ -154,20 +175,31 @@ struct erofs_inode {
 		};
 	} u;
 
+	char *i_srcpath;
+
 	unsigned char datalayout;
 	unsigned char inode_isize;
 	/* inline tail-end packing size */
 	unsigned short idata_size;
+	bool compressed_idata;
+	bool lazy_tailblock;
 
 	unsigned int xattr_isize;
 	unsigned int extent_isize;
 
+	unsigned int xattr_shared_count;
+	unsigned int *xattr_shared_xattrs;
+
 	erofs_nid_t nid;
 	struct erofs_buffer_head *bh;
 	struct erofs_buffer_head *bh_inline, *bh_data;
 
 	void *idata;
 
+	/* (ztailpacking) in order to recover uncompressed EOF data */
+	void *eof_tailraw;
+	unsigned int eof_tailrawsize;
+
 	union {
 		void *compressmeta;
 		void *chunkindexes;
@@ -176,8 +208,14 @@ struct erofs_inode {
 			uint8_t  z_algorithmtype[2];
 			uint8_t  z_logical_clusterbits;
 			uint8_t  z_physical_clusterblks;
+			uint64_t z_tailextent_headlcn;
+			unsigned int    z_idataoff;
+#define z_idata_size	idata_size
 		};
 	};
+	uint64_t capabilities;
+	erofs_off_t fragmentoff;
+	unsigned int fragment_size;
 };
 
 static inline bool is_inode_layout_compression(struct erofs_inode *inode)
@@ -216,6 +254,14 @@ struct erofs_dentry {
 	};
 };
 
+static inline bool is_dot_dotdot_len(const char *name, unsigned int len)
+{
+	if (len >= 1 && name[0] != '.')
+		return false;
+
+	return len == 1 || (len == 2 && name[1] == '.');
+}
+
 static inline bool is_dot_dotdot(const char *name)
 {
 	if (name[0] != '.')
@@ -229,6 +275,8 @@ enum {
 	BH_Mapped,
 	BH_Encoded,
 	BH_FullMapped,
+	BH_Fragment,
+	BH_Partialref,
 };
 
 /* Has a disk mapping */
@@ -239,9 +287,13 @@ enum {
 #define EROFS_MAP_ENCODED	(1 << BH_Encoded)
 /* The length of extent is full */
 #define EROFS_MAP_FULL_MAPPED	(1 << BH_FullMapped)
+/* Located in the special packed inode */
+#define EROFS_MAP_FRAGMENT	(1 << BH_Fragment)
+/* The extent refers to partial decompressed data */
+#define EROFS_MAP_PARTIAL_REF	(1 << BH_Partialref)
 
 struct erofs_map_blocks {
-	char mpage[EROFS_BLKSIZ];
+	char mpage[EROFS_MAX_BLOCK_SIZE];
 
 	erofs_off_t m_pa, m_la;
 	u64 m_plen, m_llen;
@@ -257,9 +309,12 @@ struct erofs_map_blocks {
  * approach instead if possible since it's more metadata lightweight.)
  */
 #define EROFS_GET_BLOCKS_FIEMAP	0x0002
+/* Used to map tail extent for tailpacking inline or fragment pcluster */
+#define EROFS_GET_BLOCKS_FINDTAIL	0x0008
 
 enum {
 	Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
+	Z_EROFS_COMPRESSION_INTERLACED,
 	Z_EROFS_COMPRESSION_RUNTIME_MAX
 };
 
@@ -274,6 +329,7 @@ int erofs_dev_read(int device_id, void *buf, u64 offset, size_t len);
 
 /* super.c */
 int erofs_read_superblock(void);
+void erofs_put_super(void);
 
 /* namei.c */
 int erofs_read_inode_from_disk(struct erofs_inode *vi);
@@ -283,9 +339,40 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi);
 /* data.c */
 int erofs_pread(struct erofs_inode *inode, char *buf,
 		erofs_off_t count, erofs_off_t offset);
-int erofs_map_blocks(struct erofs_inode *inode,
-		     struct erofs_map_blocks *map, int flags);
-int erofs_map_dev(struct erofs_sb_info *sbi, struct erofs_map_dev *map);
+int erofs_map_blocks(struct erofs_inode *inode, struct erofs_map_blocks *map,
+		     int flags);
+int erofs_map_dev(struct erofs_map_dev *map);
+int erofs_read_one_data(struct erofs_map_blocks *map, char *buffer, u64 offset,
+			size_t len);
+int z_erofs_read_one_data(struct erofs_inode *inode,
+			  struct erofs_map_blocks *map, char *raw, char *buffer,
+			  erofs_off_t skip, erofs_off_t length, bool trimmed);
+
+static inline int erofs_get_occupied_size(const struct erofs_inode *inode,
+					  erofs_off_t *size)
+{
+	*size = 0;
+	switch (inode->datalayout) {
+	case EROFS_INODE_FLAT_INLINE:
+	case EROFS_INODE_FLAT_PLAIN:
+	case EROFS_INODE_CHUNK_BASED:
+		*size = inode->i_size;
+		break;
+	case EROFS_INODE_COMPRESSED_FULL:
+	case EROFS_INODE_COMPRESSED_COMPACT:
+		*size = inode->u.i_blocks * erofs_blksiz();
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+/* data.c */
+int erofs_getxattr(struct erofs_inode *vi, const char *name, char *buffer,
+		   size_t buffer_size);
+int erofs_listxattr(struct erofs_inode *vi, char *buffer, size_t buffer_size);
+
 /* zmap.c */
 int z_erofs_fill_inode(struct erofs_inode *vi);
 int z_erofs_map_blocks_iter(struct erofs_inode *vi,
diff --git a/fs/erofs/namei.c b/fs/erofs/namei.c
index d1d4757..bde995f 100644
--- a/fs/erofs/namei.c
+++ b/fs/erofs/namei.c
@@ -1,6 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0+
 #include "internal.h"
 
+#define makedev(major, minor) ((dev_t)((((major) & 0xfff) << 8) | ((minor) & 0xff)))
+static dev_t erofs_new_decode_dev(u32 dev)
+{
+	const unsigned int major = (dev & 0xfff00) >> 8;
+	const unsigned int minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
+
+	return makedev(major, minor);
+}
+
 int erofs_read_inode_from_disk(struct erofs_inode *vi)
 {
 	int ret, ifmt;
@@ -26,7 +35,8 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
 	case EROFS_INODE_LAYOUT_EXTENDED:
 		vi->inode_isize = sizeof(struct erofs_inode_extended);
 
-		ret = erofs_dev_read(0, buf + sizeof(*dic), inode_loc + sizeof(*dic),
+		ret = erofs_dev_read(0, buf + sizeof(*dic),
+				     inode_loc + sizeof(*dic),
 				     sizeof(*die) - sizeof(*dic));
 		if (ret < 0)
 			return -EIO;
@@ -43,7 +53,8 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
 			break;
 		case S_IFCHR:
 		case S_IFBLK:
-			vi->u.i_rdev = 0;
+			vi->u.i_rdev =
+				erofs_new_decode_dev(le32_to_cpu(die->i_u.rdev));
 			break;
 		case S_IFIFO:
 		case S_IFSOCK:
@@ -57,8 +68,8 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
 		vi->i_gid = le32_to_cpu(die->i_gid);
 		vi->i_nlink = le32_to_cpu(die->i_nlink);
 
-		vi->i_ctime = le64_to_cpu(die->i_ctime);
-		vi->i_ctime_nsec = le64_to_cpu(die->i_ctime_nsec);
+		vi->i_mtime = le64_to_cpu(die->i_mtime);
+		vi->i_mtime_nsec = le64_to_cpu(die->i_mtime_nsec);
 		vi->i_size = le64_to_cpu(die->i_size);
 		if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
 			/* fill chunked inode summary info */
@@ -77,7 +88,8 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
 			break;
 		case S_IFCHR:
 		case S_IFBLK:
-			vi->u.i_rdev = 0;
+			vi->u.i_rdev =
+				erofs_new_decode_dev(le32_to_cpu(dic->i_u.rdev));
 			break;
 		case S_IFIFO:
 		case S_IFSOCK:
@@ -91,8 +103,8 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
 		vi->i_gid = le16_to_cpu(dic->i_gid);
 		vi->i_nlink = le16_to_cpu(dic->i_nlink);
 
-		vi->i_ctime = sbi.build_time;
-		vi->i_ctime_nsec = sbi.build_time_nsec;
+		vi->i_mtime = sbi.build_time;
+		vi->i_mtime_nsec = sbi.build_time_nsec;
 
 		vi->i_size = le32_to_cpu(dic->i_size);
 		if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
@@ -111,10 +123,13 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
 				  vi->u.chunkformat, vi->nid | 0ULL);
 			return -EOPNOTSUPP;
 		}
-		vi->u.chunkbits = LOG_BLOCK_SIZE +
+		vi->u.chunkbits = sbi.blkszbits +
 			(vi->u.chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
-	} else if (erofs_inode_is_data_compressed(vi->datalayout))
-		z_erofs_fill_inode(vi);
+	} else if (erofs_inode_is_data_compressed(vi->datalayout)) {
+		if (erofs_blksiz() != EROFS_MAX_BLOCK_SIZE)
+			return -EOPNOTSUPP;
+		return z_erofs_fill_inode(vi);
+	}
 	return 0;
 bogusimode:
 	erofs_err("bogus i_mode (%o) @ nid %llu", vi->i_mode, vi->nid | 0ULL);
@@ -163,12 +178,11 @@ struct nameidata {
 	unsigned int	ftype;
 };
 
-int erofs_namei(struct nameidata *nd,
-		const char *name, unsigned int len)
+int erofs_namei(struct nameidata *nd, const char *name, unsigned int len)
 {
 	erofs_nid_t nid = nd->nid;
 	int ret;
-	char buf[EROFS_BLKSIZ];
+	char buf[EROFS_MAX_BLOCK_SIZE];
 	struct erofs_inode vi = { .nid = nid };
 	erofs_off_t offset;
 
@@ -179,7 +193,7 @@ int erofs_namei(struct nameidata *nd,
 	offset = 0;
 	while (offset < vi.i_size) {
 		erofs_off_t maxsize = min_t(erofs_off_t,
-					    vi.i_size - offset, EROFS_BLKSIZ);
+					    vi.i_size - offset, erofs_blksiz());
 		struct erofs_dirent *de = (void *)buf;
 		unsigned int nameoff;
 
@@ -189,7 +203,7 @@ int erofs_namei(struct nameidata *nd,
 
 		nameoff = le16_to_cpu(de->nameoff);
 		if (nameoff < sizeof(struct erofs_dirent) ||
-		    nameoff >= PAGE_SIZE) {
+		    nameoff >= erofs_blksiz()) {
 			erofs_err("invalid de[0].nameoff %u @ nid %llu",
 				  nameoff, nid | 0ULL);
 			return -EFSCORRUPTED;
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 8277d9b..d339262 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -9,7 +9,7 @@ static bool check_layout_compatibility(struct erofs_sb_info *sbi,
 	sbi->feature_incompat = feature;
 
 	/* check if current kernel meets all mandatory requirements */
-	if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) {
+	if (feature & ~EROFS_ALL_FEATURE_INCOMPAT) {
 		erofs_err("unidentified incompatible feature %x, please upgrade kernel version",
 			  feature & ~EROFS_ALL_FEATURE_INCOMPAT);
 		return false;
@@ -40,14 +40,18 @@ static int erofs_init_devices(struct erofs_sb_info *sbi,
 
 	sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1;
 	sbi->devs = calloc(ondisk_extradevs, sizeof(*sbi->devs));
+	if (!sbi->devs)
+		return -ENOMEM;
 	pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE;
 	for (i = 0; i < ondisk_extradevs; ++i) {
 		struct erofs_deviceslot dis;
 		int ret;
 
 		ret = erofs_dev_read(0, &dis, pos, sizeof(dis));
-		if (ret < 0)
+		if (ret < 0) {
+			free(sbi->devs);
 			return ret;
+		}
 
 		sbi->devs[i].mapped_blkaddr = dis.mapped_blkaddr;
 		sbi->total_blocks += dis.blocks;
@@ -58,42 +62,41 @@ static int erofs_init_devices(struct erofs_sb_info *sbi,
 
 int erofs_read_superblock(void)
 {
-	char data[EROFS_BLKSIZ];
+	u8 data[EROFS_MAX_BLOCK_SIZE];
 	struct erofs_super_block *dsb;
-	unsigned int blkszbits;
 	int ret;
 
-	ret = erofs_blk_read(data, 0, 1);
+	ret = erofs_blk_read(data, 0, erofs_blknr(sizeof(data)));
 	if (ret < 0) {
-		erofs_dbg("cannot read erofs superblock: %d", ret);
+		erofs_err("cannot read erofs superblock: %d", ret);
 		return -EIO;
 	}
 	dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
 
 	ret = -EINVAL;
 	if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
-		erofs_dbg("cannot find valid erofs superblock");
+		erofs_err("cannot find valid erofs superblock");
 		return ret;
 	}
 
 	sbi.feature_compat = le32_to_cpu(dsb->feature_compat);
 
-	blkszbits = dsb->blkszbits;
-	/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
-	if (blkszbits != LOG_BLOCK_SIZE) {
-		erofs_err("blksize %u isn't supported on this platform",
-			  1 << blkszbits);
+	sbi.blkszbits = dsb->blkszbits;
+	if (sbi.blkszbits < 9 ||
+	    sbi.blkszbits > ilog2(EROFS_MAX_BLOCK_SIZE)) {
+		erofs_err("blksize %llu isn't supported on this platform",
+			  erofs_blksiz() | 0ULL);
 		return ret;
-	}
-
-	if (!check_layout_compatibility(&sbi, dsb))
+	} else if (!check_layout_compatibility(&sbi, dsb)) {
 		return ret;
+	}
 
 	sbi.primarydevice_blocks = le32_to_cpu(dsb->blocks);
 	sbi.meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);
 	sbi.xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);
 	sbi.islotbits = EROFS_ISLOTBITS;
 	sbi.root_nid = le16_to_cpu(dsb->root_nid);
+	sbi.packed_nid = le64_to_cpu(dsb->packed_nid);
 	sbi.inos = le64_to_cpu(dsb->inos);
 	sbi.checksum = le32_to_cpu(dsb->checksum);
 
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index be2599a..4f64258 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -1,14 +1,19 @@
 // SPDX-License-Identifier: GPL-2.0+
 #include "internal.h"
 
+static int z_erofs_do_map_blocks(struct erofs_inode *vi,
+				 struct erofs_map_blocks *map,
+				 int flags);
+
 int z_erofs_fill_inode(struct erofs_inode *vi)
 {
 	if (!erofs_sb_has_big_pcluster() &&
-	    vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) {
+	    !erofs_sb_has_ztailpacking() && !erofs_sb_has_fragments() &&
+	    vi->datalayout == EROFS_INODE_COMPRESSED_FULL) {
 		vi->z_advise = 0;
 		vi->z_algorithmtype[0] = 0;
 		vi->z_algorithmtype[1] = 0;
-		vi->z_logical_clusterbits = LOG_BLOCK_SIZE;
+		vi->z_logical_clusterbits = sbi.blkszbits;
 
 		vi->flags |= EROFS_I_Z_INITED;
 	}
@@ -25,15 +30,23 @@ static int z_erofs_fill_inode_lazy(struct erofs_inode *vi)
 	if (vi->flags & EROFS_I_Z_INITED)
 		return 0;
 
-	DBG_BUGON(!erofs_sb_has_big_pcluster() &&
-		  vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
 	pos = round_up(iloc(vi->nid) + vi->inode_isize + vi->xattr_isize, 8);
-
 	ret = erofs_dev_read(0, buf, pos, sizeof(buf));
 	if (ret < 0)
 		return -EIO;
 
 	h = (struct z_erofs_map_header *)buf;
+	/*
+	 * if the highest bit of the 8-byte map header is set, the whole file
+	 * is stored in the packed inode. The rest bits keeps z_fragmentoff.
+	 */
+	if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) {
+		vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
+		vi->fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
+		vi->z_tailextent_headlcn = 0;
+		goto out;
+	}
+
 	vi->z_advise = le16_to_cpu(h->h_advise);
 	vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
 	vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
@@ -44,14 +57,41 @@ static int z_erofs_fill_inode_lazy(struct erofs_inode *vi)
 		return -EOPNOTSUPP;
 	}
 
-	vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
-	if (vi->datalayout == EROFS_INODE_FLAT_COMPRESSION &&
+	vi->z_logical_clusterbits = sbi.blkszbits + (h->h_clusterbits & 7);
+	if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT &&
 	    !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
 	    !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) {
 		erofs_err("big pcluster head1/2 of compact indexes should be consistent for nid %llu",
 			  vi->nid * 1ULL);
 		return -EFSCORRUPTED;
 	}
+
+	if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
+		struct erofs_map_blocks map = { .index = UINT_MAX };
+
+		vi->idata_size = le16_to_cpu(h->h_idata_size);
+		ret = z_erofs_do_map_blocks(vi, &map,
+					    EROFS_GET_BLOCKS_FINDTAIL);
+		if (!map.m_plen ||
+		    erofs_blkoff(map.m_pa) + map.m_plen > erofs_blksiz()) {
+			erofs_err("invalid tail-packing pclustersize %llu",
+				  map.m_plen | 0ULL);
+			return -EFSCORRUPTED;
+		}
+		if (ret < 0)
+			return ret;
+	}
+	if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
+	    !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) {
+		struct erofs_map_blocks map = { .index = UINT_MAX };
+
+		vi->fragmentoff = le32_to_cpu(h->h_fragmentoff);
+		ret = z_erofs_do_map_blocks(vi, &map,
+					    EROFS_GET_BLOCKS_FINDTAIL);
+		if (ret < 0)
+			return ret;
+	}
+out:
 	vi->flags |= EROFS_I_Z_INITED;
 	return 0;
 }
@@ -66,7 +106,9 @@ struct z_erofs_maprecorder {
 	u8  type, headtype;
 	u16 clusterofs;
 	u16 delta[2];
-	erofs_blk_t pblk, compressedlcs;
+	erofs_blk_t pblk, compressedblks;
+	erofs_off_t nextpackoff;
+	bool partialref;
 };
 
 static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
@@ -93,11 +135,10 @@ static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 {
 	struct erofs_inode *const vi = m->inode;
 	const erofs_off_t ibase = iloc(vi->nid);
-	const erofs_off_t pos =
-		Z_EROFS_VLE_LEGACY_INDEX_ALIGN(ibase + vi->inode_isize +
-					       vi->xattr_isize) +
-		lcn * sizeof(struct z_erofs_vle_decompressed_index);
-	struct z_erofs_vle_decompressed_index *di;
+	const erofs_off_t pos = Z_EROFS_FULL_INDEX_ALIGN(ibase +
+			vi->inode_isize + vi->xattr_isize) +
+		lcn * sizeof(struct z_erofs_lcluster_index);
+	struct z_erofs_lcluster_index *di;
 	unsigned int advise, type;
 	int err;
 
@@ -105,29 +146,32 @@ static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 	if (err)
 		return err;
 
+	m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
 	m->lcn = lcn;
 	di = m->kaddr + erofs_blkoff(pos);
 
 	advise = le16_to_cpu(di->di_advise);
-	type = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) &
-		((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1);
+	type = (advise >> Z_EROFS_LI_LCLUSTER_TYPE_BIT) &
+		((1 << Z_EROFS_LI_LCLUSTER_TYPE_BITS) - 1);
 	switch (type) {
-	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+	case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
 		m->clusterofs = 1 << vi->z_logical_clusterbits;
 		m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
-		if (m->delta[0] & Z_EROFS_VLE_DI_D0_CBLKCNT) {
+		if (m->delta[0] & Z_EROFS_LI_D0_CBLKCNT) {
 			if (!(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
 				DBG_BUGON(1);
 				return -EFSCORRUPTED;
 			}
-			m->compressedlcs = m->delta[0] &
-				~Z_EROFS_VLE_DI_D0_CBLKCNT;
+			m->compressedblks = m->delta[0] &
+				~Z_EROFS_LI_D0_CBLKCNT;
 			m->delta[0] = 1;
 		}
 		m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
 		break;
-	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
-	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+	case Z_EROFS_LCLUSTER_TYPE_PLAIN:
+	case Z_EROFS_LCLUSTER_TYPE_HEAD1:
+		if (advise & Z_EROFS_LI_PARTIAL_REF)
+			m->partialref = true;
 		m->clusterofs = le16_to_cpu(di->di_clusterofs);
 		m->pblk = le32_to_cpu(di->di_u.blkaddr);
 		break;
@@ -164,25 +208,25 @@ static int get_compacted_la_distance(unsigned int lclusterbits,
 		lo = decode_compactedbits(lclusterbits, lomask,
 					  in, encodebits * i, &type);
 
-		if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
+		if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD)
 			return d1;
 		++d1;
 	} while (++i < vcnt);
 
-	/* vcnt - 1 (Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) item */
-	if (!(lo & Z_EROFS_VLE_DI_D0_CBLKCNT))
+	/* vcnt - 1 (Z_EROFS_LCLUSTER_TYPE_NONHEAD) item */
+	if (!(lo & Z_EROFS_LI_D0_CBLKCNT))
 		d1 += lo - 1;
 	return d1;
 }
 
 static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 				  unsigned int amortizedshift,
-				  unsigned int eofs, bool lookahead)
+				  erofs_off_t pos, bool lookahead)
 {
 	struct erofs_inode *const vi = m->inode;
 	const unsigned int lclusterbits = vi->z_logical_clusterbits;
 	const unsigned int lomask = (1 << lclusterbits) - 1;
-	unsigned int vcnt, base, lo, encodebits, nblk;
+	unsigned int vcnt, base, lo, encodebits, nblk, eofs;
 	int i;
 	u8 *in, type;
 	bool big_pcluster;
@@ -194,8 +238,12 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 	else
 		return -EOPNOTSUPP;
 
+	/* it doesn't equal to round_up(..) */
+	m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
+			 (vcnt << amortizedshift);
 	big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
 	encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
+	eofs = erofs_blkoff(pos);
 	base = round_down(eofs, vcnt << amortizedshift);
 	in = m->kaddr + base;
 
@@ -204,20 +252,19 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 	lo = decode_compactedbits(lclusterbits, lomask,
 				  in, encodebits * i, &type);
 	m->type = type;
-	if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
+	if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
 		m->clusterofs = 1 << lclusterbits;
 
 		/* figure out lookahead_distance: delta[1] if needed */
 		if (lookahead)
 			m->delta[1] = get_compacted_la_distance(lclusterbits,
-								encodebits,
-								vcnt, in, i);
-		if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
+								encodebits, vcnt, in, i);
+		if (lo & Z_EROFS_LI_D0_CBLKCNT) {
 			if (!big_pcluster) {
 				DBG_BUGON(1);
 				return -EFSCORRUPTED;
 			}
-			m->compressedlcs = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
+			m->compressedblks = lo & ~Z_EROFS_LI_D0_CBLKCNT;
 			m->delta[0] = 1;
 			return 0;
 		} else if (i + 1 != (int)vcnt) {
@@ -231,9 +278,9 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 		 */
 		lo = decode_compactedbits(lclusterbits, lomask,
 					  in, encodebits * (i - 1), &type);
-		if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
+		if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD)
 			lo = 0;
-		else if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT)
+		else if (lo & Z_EROFS_LI_D0_CBLKCNT)
 			lo = 1;
 		m->delta[0] = lo + 1;
 		return 0;
@@ -247,7 +294,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 			--i;
 			lo = decode_compactedbits(lclusterbits, lomask,
 						  in, encodebits * i, &type);
-			if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
+			if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD)
 				i -= lo;
 
 			if (i >= 0)
@@ -259,13 +306,13 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 			--i;
 			lo = decode_compactedbits(lclusterbits, lomask,
 						  in, encodebits * i, &type);
-			if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
-				if (lo & Z_EROFS_VLE_DI_D0_CBLKCNT) {
+			if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
+				if (lo & Z_EROFS_LI_D0_CBLKCNT) {
 					--i;
-					nblk += lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
+					nblk += lo & ~Z_EROFS_LI_D0_CBLKCNT;
 					continue;
 				}
-				if (lo == 1) {
+				if (lo <= 1) {
 					DBG_BUGON(1);
 					/* --i; ++nblk;	continue; */
 					return -EFSCORRUPTED;
@@ -289,7 +336,7 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 	const erofs_off_t ebase = round_up(iloc(vi->nid) + vi->inode_isize +
 					   vi->xattr_isize, 8) +
 		sizeof(struct z_erofs_map_header);
-	const unsigned int totalidx = DIV_ROUND_UP(vi->i_size, EROFS_BLKSIZ);
+	const unsigned int totalidx = BLK_ROUND_UP(vi->i_size);
 	unsigned int compacted_4b_initial, compacted_2b;
 	unsigned int amortizedshift;
 	erofs_off_t pos;
@@ -307,7 +354,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 	if (compacted_4b_initial == 32 / 4)
 		compacted_4b_initial = 0;
 
-	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
+	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
+	    compacted_4b_initial < totalidx)
 		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
 	else
 		compacted_2b = 0;
@@ -332,8 +380,7 @@ out:
 	err = z_erofs_reload_indexes(m, erofs_blknr(pos));
 	if (err)
 		return err;
-	return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos),
-				      lookahead);
+	return unpack_compacted_index(m, amortizedshift, pos, lookahead);
 }
 
 static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
@@ -341,10 +388,10 @@ static int z_erofs_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 {
 	const unsigned int datamode = m->inode->datalayout;
 
-	if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
+	if (datamode == EROFS_INODE_COMPRESSED_FULL)
 		return legacy_load_cluster_from_disk(m, lcn);
 
-	if (datamode == EROFS_INODE_FLAT_COMPRESSION)
+	if (datamode == EROFS_INODE_COMPRESSED_COMPACT)
 		return compacted_load_cluster_from_disk(m, lcn, lookahead);
 
 	return -EINVAL;
@@ -373,7 +420,7 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
 		return err;
 
 	switch (m->type) {
-	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+	case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
 		if (!m->delta[0]) {
 			erofs_err("invalid lookback distance 0 @ nid %llu",
 				  (unsigned long long)vi->nid);
@@ -381,8 +428,8 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m,
 			return -EFSCORRUPTED;
 		}
 		return z_erofs_extent_lookback(m, m->delta[0]);
-	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
-	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+	case Z_EROFS_LCLUSTER_TYPE_PLAIN:
+	case Z_EROFS_LCLUSTER_TYPE_HEAD1:
 		m->headtype = m->type;
 		map->m_la = (lcn << lclusterbits) | m->clusterofs;
 		break;
@@ -404,16 +451,17 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 	unsigned long lcn;
 	int err;
 
-	DBG_BUGON(m->type != Z_EROFS_VLE_CLUSTER_TYPE_PLAIN &&
-		  m->type != Z_EROFS_VLE_CLUSTER_TYPE_HEAD);
-	if (m->headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
+	DBG_BUGON(m->type != Z_EROFS_LCLUSTER_TYPE_PLAIN &&
+		  m->type != Z_EROFS_LCLUSTER_TYPE_HEAD1);
+
+	if (m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN ||
 	    !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) {
 		map->m_plen = 1 << lclusterbits;
 		return 0;
 	}
 
 	lcn = m->lcn + 1;
-	if (m->compressedlcs)
+	if (m->compressedblks)
 		goto out;
 
 	err = z_erofs_load_cluster_from_disk(m, lcn, false);
@@ -422,28 +470,28 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 
 	/*
 	 * If the 1st NONHEAD lcluster has already been handled initially w/o
-	 * valid compressedlcs, which means at least it mustn't be CBLKCNT, or
+	 * valid compressedblks, which means at least it mustn't be CBLKCNT, or
 	 * an internal implemenatation error is detected.
 	 *
 	 * The following code can also handle it properly anyway, but let's
 	 * BUG_ON in the debugging mode only for developers to notice that.
 	 */
 	DBG_BUGON(lcn == initial_lcn &&
-		  m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD);
+		  m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD);
 
 	switch (m->type) {
-	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
-	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+	case Z_EROFS_LCLUSTER_TYPE_PLAIN:
+	case Z_EROFS_LCLUSTER_TYPE_HEAD1:
 		/*
 		 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
 		 * rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
 		 */
-		m->compressedlcs = 1;
+		m->compressedblks = 1 << (lclusterbits - sbi.blkszbits);
 		break;
-	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+	case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
 		if (m->delta[0] != 1)
 			goto err_bonus_cblkcnt;
-		if (m->compressedlcs)
+		if (m->compressedblks)
 			break;
 		/* fallthrough */
 	default:
@@ -453,7 +501,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 		return -EFSCORRUPTED;
 	}
 out:
-	map->m_plen = m->compressedlcs << lclusterbits;
+	map->m_plen = m->compressedblks << sbi.blkszbits;
 	return 0;
 err_bonus_cblkcnt:
 	erofs_err("bogus CBLKCNT @ lcn %lu of nid %llu",
@@ -481,11 +529,11 @@ static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
 		if (err)
 			return err;
 
-		if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
+		if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
 			DBG_BUGON(!m->delta[1] &&
 				  m->clusterofs != 1 << lclusterbits);
-		} else if (m->type == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN ||
-			   m->type == Z_EROFS_VLE_CLUSTER_TYPE_HEAD) {
+		} else if (m->type == Z_EROFS_LCLUSTER_TYPE_PLAIN ||
+			   m->type == Z_EROFS_LCLUSTER_TYPE_HEAD1) {
 			/* go on until the next HEAD lcluster */
 			if (lcn != headlcn)
 				break;
@@ -504,10 +552,12 @@ static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
 	return 0;
 }
 
-int z_erofs_map_blocks_iter(struct erofs_inode *vi,
-			    struct erofs_map_blocks *map,
-			    int flags)
+static int z_erofs_do_map_blocks(struct erofs_inode *vi,
+				 struct erofs_map_blocks *map,
+				 int flags)
 {
+	bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
+	bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
 	struct z_erofs_maprecorder m = {
 		.inode = vi,
 		.map = map,
@@ -518,20 +568,8 @@ int z_erofs_map_blocks_iter(struct erofs_inode *vi,
 	unsigned long initial_lcn;
 	unsigned long long ofs, end;
 
-	/* when trying to read beyond EOF, leave it unmapped */
-	if (map->m_la >= vi->i_size) {
-		map->m_llen = map->m_la + 1 - vi->i_size;
-		map->m_la = vi->i_size;
-		map->m_flags = 0;
-		goto out;
-	}
-
-	err = z_erofs_fill_inode_lazy(vi);
-	if (err)
-		goto out;
-
 	lclusterbits = vi->z_logical_clusterbits;
-	ofs = map->m_la;
+	ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? vi->i_size - 1 : map->m_la;
 	initial_lcn = ofs >> lclusterbits;
 	endoff = ofs & ((1 << lclusterbits) - 1);
 
@@ -539,11 +577,14 @@ int z_erofs_map_blocks_iter(struct erofs_inode *vi,
 	if (err)
 		goto out;
 
+	if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL))
+		vi->z_idataoff = m.nextpackoff;
+
 	map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
 	end = (m.lcn + 1ULL) << lclusterbits;
 	switch (m.type) {
-	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
-	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+	case Z_EROFS_LCLUSTER_TYPE_PLAIN:
+	case Z_EROFS_LCLUSTER_TYPE_HEAD1:
 		if (endoff >= m.clusterofs) {
 			m.headtype = m.type;
 			map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
@@ -560,7 +601,7 @@ int z_erofs_map_blocks_iter(struct erofs_inode *vi,
 		map->m_flags |= EROFS_MAP_FULL_MAPPED;
 		m.delta[0] = 1;
 		/* fallthrough */
-	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+	case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
 		/* get the correspoinding first chunk */
 		err = z_erofs_extent_lookback(&m, m.delta[0]);
 		if (err)
@@ -572,18 +613,43 @@ int z_erofs_map_blocks_iter(struct erofs_inode *vi,
 		err = -EOPNOTSUPP;
 		goto out;
 	}
-
+	if (m.partialref)
+		map->m_flags |= EROFS_MAP_PARTIAL_REF;
 	map->m_llen = end - map->m_la;
-	map->m_pa = blknr_to_addr(m.pblk);
-
-	err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
-	if (err)
-		goto out;
+	if (flags & EROFS_GET_BLOCKS_FINDTAIL) {
+		vi->z_tailextent_headlcn = m.lcn;
+		/* for non-compact indexes, fragmentoff is 64 bits */
+		if (fragment && vi->datalayout == EROFS_INODE_COMPRESSED_FULL)
+			vi->fragmentoff |= (u64)m.pblk << 32;
+	}
+	if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
+		map->m_flags |= EROFS_MAP_META;
+		map->m_pa = vi->z_idataoff;
+		map->m_plen = vi->z_idata_size;
+	} else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
+		map->m_flags |= EROFS_MAP_FRAGMENT;
+	} else {
+		map->m_pa = erofs_pos(m.pblk);
+		err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
+		if (err)
+			goto out;
+	}
 
-	if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN)
-		map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
-	else
+	if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) {
+		if (map->m_llen > map->m_plen) {
+			DBG_BUGON(1);
+			err = -EFSCORRUPTED;
+			goto out;
+		}
+		if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
+			map->m_algorithmformat =
+				Z_EROFS_COMPRESSION_INTERLACED;
+		else
+			map->m_algorithmformat =
+				Z_EROFS_COMPRESSION_SHIFTED;
+	} else {
 		map->m_algorithmformat = vi->z_algorithmtype[0];
+	}
 
 	if (flags & EROFS_GET_BLOCKS_FIEMAP) {
 		err = z_erofs_get_extent_decompressedlen(&m);
@@ -595,7 +661,38 @@ out:
 	erofs_dbg("m_la %" PRIu64 " m_pa %" PRIu64 " m_llen %" PRIu64 " m_plen %" PRIu64 " m_flags 0%o",
 		  map->m_la, map->m_pa,
 		  map->m_llen, map->m_plen, map->m_flags);
+	return err;
+}
 
+int z_erofs_map_blocks_iter(struct erofs_inode *vi,
+			    struct erofs_map_blocks *map,
+			    int flags)
+{
+	int err = 0;
+
+	/* when trying to read beyond EOF, leave it unmapped */
+	if (map->m_la >= vi->i_size) {
+		map->m_llen = map->m_la + 1 - vi->i_size;
+		map->m_la = vi->i_size;
+		map->m_flags = 0;
+		goto out;
+	}
+
+	err = z_erofs_fill_inode_lazy(vi);
+	if (err)
+		goto out;
+
+	if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) &&
+	    !vi->z_tailextent_headlcn) {
+		map->m_la = 0;
+		map->m_llen = vi->i_size;
+		map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_FULL_MAPPED |
+				EROFS_MAP_FRAGMENT;
+		goto out;
+	}
+
+	err = z_erofs_do_map_blocks(vi, map, flags);
+out:
 	DBG_BUGON(err < 0 && err != -ENOMEM);
 	return err;
 }