From 4afe6b8d21e5ff644fedd7db5673fe5a48b177b7 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 25 Apr 2024 20:59:44 +0100 Subject: erofs: don't round offset down for erofs_read_metabuf() There's only one place where struct z_erofs_maprecorder ->kaddr is used not in the same function that has assigned it - the value read in unpack_compacted_index() gets calculated in z_erofs_load_compact_lcluster(). With minor massage we can switch to storing it with offset in block already added. Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20240425195944.GE1031757@ZenIV Signed-off-by: Gao Xiang --- fs/erofs/zmap.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index 8979def17b58..9b248ee5fef2 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -34,13 +34,13 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m, unsigned int advise; m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb, - erofs_pos(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); m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK; @@ -109,7 +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; @@ -127,11 +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); - i = (eofs - base) >> amortizedshift; + in = m->kaddr - bytes; + + i = bytes >> amortizedshift; lo = decode_compactedbits(lobits, in, encodebits * i, &type); m->type = type; @@ -256,7 +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_pos(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); -- cgit v1.2.3