[PATCH v2 2/2] erofs-utils: lib: clean up z_erofs_load_full_lcluster()

[Gao Xiang]

Let's keep in sync with kernel commit d69189428d50 ("erofs: clean up
z_erofs_load_full_lcluster()").

Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
v2:
 - fix build error in erofs_check_ondisk_layout_definitions().

 include/erofs_fs.h |  7 ++-----
 lib/compress.c     | 15 +++++----------
 lib/zmap.c         | 20 +++++---------------
 3 files changed, 12 insertions(+), 30 deletions(-)

diff --git a/include/erofs_fs.h b/include/erofs_fs.h
index fc21915..c579ba0 100644
--- a/include/erofs_fs.h
+++ b/include/erofs_fs.h
@@ -414,8 +414,7 @@ enum {
 	Z_EROFS_LCLUSTER_TYPE_MAX
 };
 
-#define Z_EROFS_LI_LCLUSTER_TYPE_BITS        2
-#define Z_EROFS_LI_LCLUSTER_TYPE_BIT         0
+#define Z_EROFS_LI_LCLUSTER_TYPE_MASK	(Z_EROFS_LCLUSTER_TYPE_MAX - 1)
 
 /* (noncompact only, HEAD) This pcluster refers to partial decompressed data */
 #define Z_EROFS_LI_PARTIAL_REF		(1 << 15)
@@ -474,9 +473,7 @@ static inline void erofs_check_ondisk_layout_definitions(void)
 		     sizeof(struct z_erofs_lcluster_index));
 	BUILD_BUG_ON(sizeof(struct erofs_deviceslot) != 128);
 
-	BUILD_BUG_ON(BIT(Z_EROFS_LI_LCLUSTER_TYPE_BITS) <
-		     Z_EROFS_LCLUSTER_TYPE_MAX - 1);
-#ifndef __cplusplus
+`#ifndef __cplusplus
 	/* exclude old compiler versions like gcc 7.5.0 */
 	BUILD_BUG_ON(__builtin_constant_p(fmh.v) ?
 		     fmh.v != cpu_to_le64(1ULL << 63) : 0);
diff --git a/lib/compress.c b/lib/compress.c
index d75e9c3..c679843 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -129,7 +129,7 @@ static void z_erofs_write_indexes_final(struct z_erofs_compress_ictx *ctx)
 
 	di.di_clusterofs = cpu_to_le16(ctx->clusterofs);
 	di.di_u.blkaddr = 0;
-	di.di_advise = cpu_to_le16(type << Z_EROFS_LI_LCLUSTER_TYPE_BIT);
+	di.di_advise = cpu_to_le16(type);
 
 	memcpy(ctx->metacur, &di, sizeof(di));
 	ctx->metacur += sizeof(di);
@@ -159,8 +159,7 @@ static void z_erofs_write_extent(struct z_erofs_compress_ictx *ctx,
 		DBG_BUGON(e->partial);
 		type = e->raw ? Z_EROFS_LCLUSTER_TYPE_PLAIN :
 			Z_EROFS_LCLUSTER_TYPE_HEAD1;
-		advise = type << Z_EROFS_LI_LCLUSTER_TYPE_BIT;
-		di.di_advise = cpu_to_le16(advise);
+		di.di_advise = cpu_to_le16(type);
 
 		if (inode->datalayout == EROFS_INODE_COMPRESSED_FULL &&
 		    !e->compressedblks)
@@ -218,8 +217,7 @@ static void z_erofs_write_extent(struct z_erofs_compress_ictx *ctx,
 				advise |= Z_EROFS_LI_PARTIAL_REF;
 			}
 		}
-		advise |= type << Z_EROFS_LI_LCLUSTER_TYPE_BIT;
-		di.di_advise = cpu_to_le16(advise);
+		di.di_advise = cpu_to_le16(advise | type);
 
 		memcpy(ctx->metacur, &di, sizeof(di));
 		ctx->metacur += sizeof(di);
@@ -758,8 +756,7 @@ static void *parse_legacy_indexes(struct z_erofs_compressindex_vec *cv,
 		struct z_erofs_lcluster_index *const di = db + i;
 		const unsigned int advise = le16_to_cpu(di->di_advise);
 
-		cv->clustertype = (advise >> Z_EROFS_LI_LCLUSTER_TYPE_BIT) &
-			((1 << Z_EROFS_LI_LCLUSTER_TYPE_BITS) - 1);
+		cv->clustertype = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK;
 		cv->clusterofs = le16_to_cpu(di->di_clusterofs);
 
 		if (cv->clustertype == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
@@ -987,10 +984,8 @@ void z_erofs_drop_inline_pcluster(struct erofs_inode *inode)
 		struct z_erofs_lcluster_index *di =
 			(inode->compressmeta + inode->extent_isize) -
 			sizeof(struct z_erofs_lcluster_index);
-		__le16 advise =
-			cpu_to_le16(type << Z_EROFS_LI_LCLUSTER_TYPE_BIT);
 
-		di->di_advise = advise;
+		di->di_advise = cpu_to_le16(type);
 	} else if (inode->datalayout == EROFS_INODE_COMPRESSED_COMPACT) {
 		/* handle the last compacted 4B pack */
 		unsigned int eofs, base, pos, v, lo;
diff --git a/lib/zmap.c b/lib/zmap.c
index e04a99a..f1cdc66 100644
--- a/lib/zmap.c
+++ b/lib/zmap.c
@@ -152,7 +152,7 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
 			vi->inode_isize + vi->xattr_isize) +
 		lcn * sizeof(struct z_erofs_lcluster_index);
 	struct z_erofs_lcluster_index *di;
-	unsigned int advise, type;
+	unsigned int advise;
 	int err;
 
 	err = z_erofs_reload_indexes(m, erofs_blknr(sbi, pos));
@@ -164,10 +164,8 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
 	di = m->kaddr + erofs_blkoff(sbi, pos);
 
 	advise = le16_to_cpu(di->di_advise);
-	type = (advise >> Z_EROFS_LI_LCLUSTER_TYPE_BIT) &
-		((1 << Z_EROFS_LI_LCLUSTER_TYPE_BITS) - 1);
-	switch (type) {
-	case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
+	m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK;
+	if (m->type == 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_LI_D0_CBLKCNT) {
@@ -180,19 +178,11 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
 			m->delta[0] = 1;
 		}
 		m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
-		break;
-	case Z_EROFS_LCLUSTER_TYPE_PLAIN:
-	case Z_EROFS_LCLUSTER_TYPE_HEAD1:
-		if (advise & Z_EROFS_LI_PARTIAL_REF)
-			m->partialref = true;
+	} else {
+		m->partialref = !!(advise & Z_EROFS_LI_PARTIAL_REF);
 		m->clusterofs = le16_to_cpu(di->di_clusterofs);
 		m->pblk = le32_to_cpu(di->di_u.blkaddr);
-		break;
-	default:
-		DBG_BUGON(1);
-		return -EOPNOTSUPP;
 	}
-	m->type = type;
 	return 0;
 }
 
-- 
2.43.5