1 files changed, 18 insertions, 30 deletions

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 6bd435a565..74d3d7bffc 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -31,22 +31,20 @@ 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;
 
 	m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
-				      erofs_blknr(inode->i_sb, pos), EROFS_KMAP);
+				      pos, EROFS_KMAP);
 	if (IS_ERR(m->kaddr))
 		return PTR_ERR(m->kaddr);
 
 	m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
 	m->lcn = lcn;
-	di = m->kaddr + erofs_blkoff(inode->i_sb, pos);
+	di = m->kaddr;
 
 	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) {
@@ -60,24 +58,15 @@ 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:
-	case Z_EROFS_LCLUSTER_TYPE_HEAD2:
-		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);
 		if (m->clusterofs >= 1 << vi->z_logical_clusterbits) {
 			DBG_BUGON(1);
 			return -EFSCORRUPTED;
 		}
 		m->pblk = le32_to_cpu(di->di_u.blkaddr);
-		break;
-	default:
-		DBG_BUGON(1);
-		return -EOPNOTSUPP;
 	}
-	m->type = type;
 	return 0;
 }
 
@@ -120,7 +109,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 {
 	struct erofs_inode *const vi = EROFS_I(m->inode);
 	const unsigned int lclusterbits = vi->z_logical_clusterbits;
-	unsigned int vcnt, base, lo, lobits, encodebits, nblk, eofs;
+	unsigned int vcnt, lo, lobits, encodebits, nblk, bytes;
 	int i;
 	u8 *in, type;
 	bool big_pcluster;
@@ -138,11 +127,11 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 	big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
 	lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
 	encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
-	eofs = erofs_blkoff(m->inode->i_sb, pos);
-	base = round_down(eofs, vcnt << amortizedshift);
-	in = m->kaddr + base;
+	bytes = pos & ((vcnt << amortizedshift) - 1);
+
+	in = m->kaddr - bytes;
 
-	i = (eofs - base) >> amortizedshift;
+	i = bytes >> amortizedshift;
 
 	lo = decode_compactedbits(lobits, in, encodebits * i, &type);
 	m->type = type;
@@ -267,7 +256,7 @@ static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
 out:
 	pos += lcn * (1 << amortizedshift);
 	m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
-				      erofs_blknr(inode->i_sb, pos), EROFS_KMAP);
+				      pos, EROFS_KMAP);
 	if (IS_ERR(m->kaddr))
 		return PTR_ERR(m->kaddr);
 	return unpack_compacted_index(m, amortizedshift, pos, lookahead);
@@ -561,7 +550,8 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	if ((flags & EROFS_GET_BLOCKS_FIEMAP) ||
 	    ((flags & EROFS_GET_BLOCKS_READMORE) &&
 	     (map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA ||
-	      map->m_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE) &&
+	      map->m_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE ||
+	      map->m_algorithmformat == Z_EROFS_COMPRESSION_ZSTD) &&
 	      map->m_llen >= i_blocksize(inode))) {
 		err = z_erofs_get_extent_decompressedlen(&m);
 		if (!err)
@@ -580,7 +570,6 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 	int err, headnr;
 	erofs_off_t pos;
 	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
-	void *kaddr;
 	struct z_erofs_map_header *h;
 
 	if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) {
@@ -600,13 +589,12 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 		goto out_unlock;
 
 	pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8);
-	kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(sb, pos), EROFS_KMAP);
-	if (IS_ERR(kaddr)) {
-		err = PTR_ERR(kaddr);
+	h = erofs_read_metabuf(&buf, sb, pos, EROFS_KMAP);
+	if (IS_ERR(h)) {
+		err = PTR_ERR(h);
 		goto out_unlock;
 	}
 
-	h = kaddr + erofs_blkoff(sb, pos);
 	/*
 	 * 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.