[PATCH 4/8] erofs-utils: add big physical cluster definition

[Gao Xiang]

This keeps in sync with the kernel definition.

Signed-off-by: Gao Xiang <xiang at kernel.org>
---
 include/erofs/internal.h |  1 +
 include/erofs_fs.h       | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 6e481faa8c9f..1339341a0792 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -108,6 +108,7 @@ static inline void erofs_sb_clear_##name(void) \
 
 EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
+EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
 
 #define EROFS_I_EA_INITED	(1 << 0)
diff --git a/include/erofs_fs.h b/include/erofs_fs.h
index a24deb095537..52da7abaac92 100644
--- a/include/erofs_fs.h
+++ b/include/erofs_fs.h
@@ -21,9 +21,11 @@
  */
 #define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING	0x00000001
 #define EROFS_FEATURE_INCOMPAT_COMPR_CFGS	0x00000002
+#define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER	0x00000002
 #define EROFS_ALL_FEATURE_INCOMPAT		\
 	(EROFS_FEATURE_INCOMPAT_LZ4_0PADDING | \
-	 EROFS_FEATURE_INCOMPAT_COMPR_CFGS)
+	 EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
+	 EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER)
 
 /* 128-byte erofs on-disk super block */
 struct erofs_super_block {
@@ -199,6 +201,9 @@ static inline unsigned int erofs_xattr_entry_size(struct erofs_xattr_entry *e)
 				 e->e_name_len + le16_to_cpu(e->e_value_size));
 }
 
+/* maximum supported size of a physical compression cluster */
+#define Z_EROFS_PCLUSTER_MAX_SIZE	(1024 * 1024)
+
 /* available compression algorithm types (for h_algorithmtype) */
 enum {
 	Z_EROFS_COMPRESSION_LZ4	= 0,
@@ -208,17 +213,20 @@ enum {
 /* 14 bytes (+ length field = 16 bytes) */
 struct z_erofs_lz4_cfgs {
 	__le16 max_distance;
-	u8 reserved[12];
+	__le16 max_pclusterblks;
+	u8 reserved[10];
 } __packed;
 
 /*
  * bit 0 : COMPACTED_2B indexes (0 - off; 1 - on)
  *  e.g. for 4k logical cluster size,      4B        if compacted 2B is off;
  *                                  (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)
  */
-#define Z_EROFS_ADVISE_COMPACTED_2B_BIT         0
-
-#define Z_EROFS_ADVISE_COMPACTED_2B     (1 << Z_EROFS_ADVISE_COMPACTED_2B_BIT)
+#define Z_EROFS_ADVISE_COMPACTED_2B		0x0001
+#define Z_EROFS_ADVISE_BIG_PCLUSTER_1		0x0002
+#define Z_EROFS_ADVISE_BIG_PCLUSTER_2		0x0004
 
 struct z_erofs_map_header {
 	__le32	h_reserved1;
@@ -275,6 +283,13 @@ enum {
 #define Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS        2
 #define Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT         0
 
+/*
+ * 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)
+
 struct z_erofs_vle_decompressed_index {
 	__le16 di_advise;
 	/* where to decompress in the head cluster */
-- 
2.20.1